linux bridge + firewall mini - howto version 1. 2. 0 - 3. 1 software - 3. 2 prior reading. - 3. 3 boot configuration - 3. 4 kernel configuration - 3. 5 network addresses - 3. 6 network routing - 3. 7 card configuration - 3. 8 additional routing - 3. 9 bridge configuration - 3. 10 try it out - 3. 11 checks - 4. 1 software and reading - 4. 2 preliminary checks - 4. 3 default rule - 4. 4 holes per address - 4. 5 holes per protocol - 4. 6 checks a bridge is an intelligent connecting wire betwen two network cards. a firewall is an intelligent insulator. you might want a bridge if you have several computers : - to save the price of a new hub when you just happen to have an extra ethernet card available. - to save the bother of learning how to do ip - forwarding and other tricks when you _ have _ two cards in your computer. - to avoid maintenance work in the future when things change around! ` ` several computers ' ' might be as few as three if those are routing or bridging or just moving around the room from time to time! you also might want a bridge just for the fun of finding out what it does. 2 was what i wanted a bridge for. you want a firewall if - you are trying to protect your network from external accesses, or - you are trying to deny access to the world outside from your network. curiously, i needed 2 here too. policy at my university presently is that we should not act as internet service providers to undergraduates. i started out bridging the network cards in a firewalling machine and ended up firewalling without having cut the bridge. it seems to work and is more flexible than either configuration alone. i can take down the firewall and keep bridging or take down the bridge when i want to be more circumspect. i would guess that the bridge code lives just above the physical device layer and the firewalling code lives one layer higher up, so that the bridging and firewalling configurations effectively act as though they are running connected together ` ` in sequence ' ' and not ` ` in parallel ' ' ( ouch! ). diagram : - > bridge - in - > firewall - in - > kernel - > firewall - out - > bridge - out - > there is no other way to explain how one machine can be a ` `


( ouch! ). diagram : - > bridge - in - > firewall - in - > kernel - > firewall - out - > bridge - out - > there is no other way to explain how one machine can be a ` ` conductor ' ' and an ` ` insulator ' ' at the same time. there are a few caveats but i ' ll come to those later. basically you must route packets that you want to firewall. anyway, it all seems to work together nicely for me. here is what you do... get the bridge configuration utility from alan cox ' s home pages. this is the same reference as in chris ' document. i just didn ' t realize that it was an ftp and not an http url... read the multiple ethernet howto for some advice on getting more than one network card recognized and configured. yet more details of the kind of boot magic that you may need are in the boot prompt howto. you may be able to get away without the net - 2 howto. it is a good long read and you will have to pick from it the details you need. the reading material above will tell you that you need to prepare the kernel to recognize a second ethernet device at boot up by adding this to your / etc / lilo. conf, and then re - run lilo : append = " ether = 0, 0, eth1 " note the " eth1 ". " eth0 " is the first card. " eth1 " is the second card. you can always add the boot parameters in your response to the line that lilo offers you. this is for three cards : linux ether = 0, 0, eth1 ether = 0, 0, eth2 i use loadlin to boot my kernel from dos : loadlin. exe c : \ vmlinuz root = / dev / hda3 ro ether = 0, 0, eth1 ether = 0, 0, eth2 note that this trick makes the kernel probe at bootup. that will not happen if you load the ethernet drivers as modules ( for safety since the probe order can ' t be determined ) so if you use modules you will have to add the appropriate irq and port parameters for the driver in your / etc / conf. modules. i have at least alias eth0 3c509 alias eth1 de620 options 3c509 irq = 5 io = 0


for connecting to the net so you need an address and you need to make sure that you have the loopback device configured in the normal way so that your software can talk to the places they expect to be able to talk to. if loopback is down the name resolver or other net sevices might fail. see the net - 2 - howto, but your standard configuration should already have done this bit : ifconfig lo 127. 0. 0. 1 route add - net 127. 0. 0. 0 you will have to give addresses to your network cards. i altered the / etc / rc. d / rc. inet1 file in my slackware ( 3. x ) to setup two cards and you should also essentially just look for your net configuration file and double or treble the number of instructions in it. suppose that you already have an address at ( that is in the private net reserved address space, but never mind - it won ' t hurt anybody if you use this address by mistake ) then you probably already have a line like ifconfig eth0 192. 168. 2. 100 netmask 255. 255. 255. 0 metric 1 in your configuration. the first thing you are going to probably want to do is cut the address space reached by this card in half so that you can eventually bridge or firewall the two halves. so add a line which reduces the mask to address a smaller number of machines : ifconfig eth0 netmask 255. 255. 255. 128 try it too. that restricts the card to at most the address space between. 0 and. 127. now you can set your second card up in the other half of the local address space. make sure that nobody already has the address. for symmetry i set it at 228 = 128 + 100 here. any address will do so long as it is not in the other card ' s mask, and even then, well, maybe. avoid special addresses like. 0,. 1,. 128 etc. unless you really know what you are doing. ifconfig eth1 192. 168. 2. 228 netmask 255. 255. 255. 128 metric 1 that restricts the second card to addresses between. 128 and. 255. this is where i have to announce the caveats in the bridging + firewalling scheme : you cannot firewall packets which are not routed. no routes, no firewall. at least this appears to be true in


and. 255. this is where i have to announce the caveats in the bridging + firewalling scheme : you cannot firewall packets which are not routed. no routes, no firewall. at least this appears to be true in the 2. 0. 30 and more recent kernels. the firewalling filters are closely involved with the ip - forwarding code. that does not mean that you cannot bridge. you can bridge between two cards and firewall them from a third. you can have only two cards and firewall both of them against an outside ip such as a nearby router, provided that the router is routed by you to exactly one of the cards. in other words, since i will be doing firewalling, so i want to precisely control the physical destination of some packets. i have the small net of machines attached to a hub hanging off eth0, so i configure a net there : route add - net 192. 168. 2. 128 netmask 255. 255. 255. 128 dev eth0 the 128 would be 0 if i had a full class c network there. i don ' t, by definition, since i just halved the address space. the " dev eth0 " is not necessary here because the cards address falls within the mask, but it may be necessary for you. one might need more than one card holding up this subnet ( 127 machines on one segment, oh yeah ) but those cards would be being bridged under the same netmask so that they appear as one to the routing code. on the other card i have a line going straight through to a big router that i trust. client 129 _ _ | _ _ client 1 \. 0. 128 | / net 1 client 2 - - - hub - eth0 - kernel - eth1 - hub - router - - - net 2 client 3 _ _ /. 100. 228. 2 | \ _ _ net 3 | client 254 i attach the address of the router to that card as a fixed ( " static " ) route because it would otherwise fall within the first cards netmask and the kernel would be thinking wrongly about how to send packets to the big router. i will want to firewall these packets and that is another reason fow wanting to route them specifically. route add 192. 168. 2. 2 dev eth1 i don ' t need it, since i don ' t have any more machines in that half


- based attenuation - - the strengthening or weakening of a sound ' s dynamic level as it approaches or leaves the listener. - position - based panning - - the location of a sound is calculated relative to the listener, not merely shifting between speakers. - doppler effects - - the perceived rise and fall of a sound ' s pitch as a source approaches and leaves the listener. - sound radiation - - control of a sound ' s dispersion through the acoustic field. openal resources on - line the author would like to thank joseph i. valenzuela, michael vance, bernd kreimeier, fotis hadginikos, and derrick story for their vast assistance. this series of articles could not have been written without their help. the iasig level 2 guidelines specify a set of environment parameters for reverberation. work has already begun to incorporate those parameters into the openal api. the current openal api reference can be found in the openal / docs directory, but it is in sgml format. you will need the docbook tools to compile the api documentation into readable html. the reference documentation is also available on - line here. i should emphasize that the documentation is directed only to developers at this time. as an open source project with corporate blessings, openal seems assured of widespread implementation. it offers an open source solution to the problem of highly portable cross - platform support for 3d audio in games and other multimedia applications, making it of great interest to developers and end - users alike. even while the 1. 0 specification is being ratified, some developers are already employing openal ' s services. openal is not without its contenders, but those solutions are proprietary or locked into a single architecture. openal is already a working multi - platform interface for audio ( especially 3d audio ) services, and with hardware acceleration, openal could revolutionize computer audio in the same way as opengl revolutionized computer graphics, an exciting prospect indeed. as a final reminder, please note that openal is a community effort, and community involvement is encouraged. see the openal web site for complete details on getting involved in the project. in the last article we will take a deeper look at the internals of the api, but first we ' ll discuss 3d audio and then see what real - world applications have already employed the openal specification. discuss this article in the o ' reilly network linux forum. return to the linux devcenter.


the given value ( or the default ) does not match the " long " block size of the device, the appropriate btl is deduced from the error response and printed ( to stderr ). the idea is that the user will retry this utility with the correct transfer length. if a defective block is found and its contents, if any, has been retrieved then " sg _ reassign " could be used to map out the defective block. associated with such an action the number of elements in the " grown " defect list could be monitored ( with " sg _ reassign - - grown " ) as the disk could be nearing the end of its useful lifetime. various numeric arguments ( e. g. lba ) may include multiplicative suffixes or be given in hexadecimal. see the " numeric arguments " section in the sg3 _ utils ( 8 ) man page. as a data point, fujitsu uses a 54 byte ecc ( per block ) which is capable of correcting up to a single burst error or 216 bits " on the fly ". [ information obtained from mav20xxrc product manual. ] the exit status of sg _ read _ long is 0 when it is successful. otherwise see the sg3 _ utils ( 8 ) man page.


the patrick administration has been working to enhance its long - term financial planning based on best practices prescribed by the government finance officers association ( gfoa ). best practices include the use of a sound conceptual approach, ensuring that near - term decisions measure long - term impacts, and developing a solution framework that is aligned with policy goals. the commonwealth has implemented a conceptual approach of “ structural balance “ that is designed to delineate among different causes of fiscal imbalance. the application of this approach identifies three critical challenges facing the commonwealth : a remaining structural deficit due to the significant reduction in tax revenue since the recession, cost inflation on safety net and health care programs, and the need to improve policy measures to address economic volatility. each of these challenges is a central feature of our fy12 budget proposal as further described in the conclusion to this section. structural balance approach and analysis the goal of structural balance is to base spending on policy priorities and a predictable level of sustainable revenue. our supporting analysis includes a five - year forecast for revenue and spending based on historical trends as well as the outlook for the state economy. the forecast includes a projection of tax revenue, based on input from local economists, that also provides the basis to develop an estimated long - term trend - line for tax revenue. the forecast indicates that the state economy will be below trend during a four year recovery period beginning in fiscal year 2012 before reaching a “ steady - state ” level of long - term tax revenue growth of approximately 5 % in 2016. the imputed trend - line was developed using the tax revenue figures from 2016 and discounting revenue back by the estimated 5 % annually. a similar approach was taken to develop a pre - recession revenue trend - line and select results of this analysis are highlighted in the exhibit below. ( note : the time horizon in the exhibit has been truncated in order to emphasize the key findings discussed below ). the results of this analysis provide three useful insights into our near - term fiscal challenges. first, tax revenue in fy07 ( i. e. pre - recession ) was approximately $ 2 billion greater than the then current trend - line. second, the impact of the recession on this trend - line after fy09 was a significant downward shift of an additional $ 2 billion. finally, the outlook for the economy suggests that recovery in tax revenue will be only modest : approximately $ 500 million based on the difference between the trend and forecast for tax revenue in fy12. the combined impact of these effects is that the fy12 budget will


fragile x syndrome ( cont. ) a variety of professionals can help individuals with fragile x and their families deal with symptoms of the disorder. such assistance is usually most effective when provided by health care professionals experienced with fragile x. - speech - language therapists can help people with fragile x to improve their pronunciation of words and sentences, slow down speech, and use language more effectively. they may set up social or problem - solving situations to help a child practice using language in meaningful ways. for the minority of children who fail to develop functional speech, this type of specialist may work with other specialists to design and teach nonverbal ways of communication. for example, some children may prefer to use small picture cards arranged on a key ring to express themselves ; or they may learn to use a hand - held computer that is programmed to " say " words and phrases when a single key is pressed. - occupational therapists help find ways to adjust tasks and conditions to match a person ' s needs and abilities. for example, this type of therapist might teach parents to swaddle or massage their baby who has fragile x to calm him or her. or the therapist might find a specially designed computer mouse and keyboard or a pencil that is easier for a child with poor motor control to grip. at the high school level, an occupational therapist can help a teenager with fragile x identify a job, career, or skill that matches his or her interests and individual capabilities. 17 - physical therapists design activities and exercises to build motor control and to improve posture and balance. they can teach parents ways to exercise their baby ' s muscles. at school, a physical therapist may help a child who is easily over - stimulated or who avoids body contact to participate in sports and games with other children. - behavioral therapists try to identify why a child acts in negative ways and then seek ways to prevent these distressing situations, and to teach the child to cope with the distress. this type of specialist also works with parents and teachers to find useful responses to desirable and undesirable behavior. during puberty, rising and changing hormone levels can cause adolescents to become more aggressive. a behavioral therapist can help a teenager recognize his or her intense emotions and teach healthy ways to calm down. the services of these specialists may be available to pre - school and school - aged children, as well as to teens, through the local public school system. in a school setting, several specialists often work together to assess each child ' s particular strengths and weaknesses, and to plan a program that is specially tailored


of organic matter such as vegetation, or chemical reactions with some sulfur - containing minerals in the soil and rock, may naturally create hydrogen sulfide in gas in groundwater. as groundwater moves through soil and rock formations containing minerals of sulfate, some of these minerals dissolve in the water. a unique group of bacteria, called " sulfur bacteria " or " sulfate - reducing bacteria " can change sulfate and other sulfur containing compounds, including natural organic materials, to hydrogen sulfide gas. how is hydrogen sulfide gas produced in a water heater? a water heater can provide an ideal environment for the conversion of sulfate to hydrogen sulfide gas. the water heater can produce hydrogen sulfide gas in two ways - creating a warm environment where sulfur bacteria can live, and sustaining a reaction between sulfate in the water and the water heater anode. a water heater usually contains a metal rod called an " anode, " which is installed to reduce corrosion of the water heater tank. the anode is usually made of magnesium metal, which can supply electrons that aid in the conversion of sulfate to hydrogen sulfide gas. the anode is 1 / 2 to 3 / 4 inches in diameter and 30 to 40 inches long. how can i find the source of a hydrogen sulfide problem, and what can i do to eliminate it? the odor of hydrogen sulfide gas can be detected in water at a very low level. smell the water coming out of the hot and cold water faucets. determine which faucets have the odor. the " rotten egg " smell will often be more noticeable from the hot water because more of the gas is vaporized. your sense of smell becomes dulled quickly, so the best time to check is after you have been away from your home for a few hours. you can also have the water tested for hydrogen sulfide, sulfate, sulfur bacteria, and iron bacteria at an environmental testing laboratory. the cost of testing for hydrogen sulfide ranges from $ 20 to $ 50 depending on the type of test. - if the smell is only from the hot water faucet the problem is likely to be in the water heater. - if the smell is in both the hot and cold faucets, but only from the water treated by a water softener and not in the untreated water the problem is likely to be sulfur bacteria in the water - if the smell is strong when the water in both the hot and cold faucets is first turned on, and it diminishes or goes away after


sources & references according to the american psychiatric association, a phobia is an uncontrollable, irrational, and persistent fear of a specific object, situation, or activity. the fear experienced by people with phobias can be so great that some individuals go to extreme lengths to avoid the source of their fear. one extreme response to the source of a phobia can be a panic attack. every year, approximately 19 million americans experience one or more phobias that range from mild to severe. phobias can occur in early childhood, but usually are first evident between the ages of 15 and 20 years. they affect both genders equally, although men are more likely to seek treatment for phobias. research suggests that both genetic and environmental factors contribute to the onset of phobias. specific phobias have been associated with a fearful first encounter with the phobic object or situation. the question still exists, however, whether this conditioning exposure is necessary or if phobias can develop in genetically predisposed individuals. | specific phobia | | what is specific phobia? | specific phobia is characterized by extreme fear of an object or situation that is not harmful under general conditions. examples may include a fear of the following : - flying ( fearing the plane will crash ) - dogs ( fearing the dog will bite / attack ) - closed - in places ( fear of being trapped ) - tunnels ( fearing a collapse ) - heights ( fear of falling ) what are the characteristics of specific phobia? people with specific phobias know that their fear is excessive, but are unable to overcome their emotion. the disorder is diagnosed only when the specific fear interferes with daily activities of school, work, or home life. approximately 19 million american adults ages 18 to 54, in a given year, have some type of specific phobia. there is no known cause, although they seem to run in families and are slightly more prevalent in women. if the object of the fear is easy to avoid, people with phobias may not feel the need to seek treatment. sometimes, however, they may make important career or personal decisions to avoid a situation that includes the source of the phobia. treatment for specific phobia there is currently no proven drug treatment for specific phobias, however, in some cases, certain medications may be prescribed to help reduce anxiety symptoms before someone faces a phobic situation. when phobias interfere with a person ' s life, treatment can help,


proven drug treatment for specific phobias, however, in some cases, certain medications may be prescribed to help reduce anxiety symptoms before someone faces a phobic situation. when phobias interfere with a person ' s life, treatment can help, and usually involves a kind of cognitive - behavioral therapy called desensitization or exposure therapy. in this, patients are gradually exposed to what frightens them until the fear begins to fade. relaxation and breathing exercises also help to reduce anxiety symptoms. | social phobia | | what is social phobia? | social phobia is an anxiety disorder in which a person has significant anxiety and discomfort related to a fear of being embarrassed, humiliated, or scorned by others in social or performance situations. even when they manage to confront this fear, persons with social phobia usually : - feel very anxious before the event / outing - feel intensely uncomfortable throughout the event / outing - have lingering unpleasant feelings after the event / outing social phobia frequently occurs with the following : - public speaking - meeting people - dealing with authority figures - eating in public - using public restrooms what are the characteristics of social phobia? although this disorder is often thought of as shyness, the two are not the same. shy people can be very uneasy around others, but they do not experience the extreme anxiety in anticipating a social situation, and, they do not necessarily avoid circumstances that make them feel self - conscious. in contrast, people with social phobia are not necessarily shy at all, but can be completely at ease with some people most of the time. most people experiencing social phobia will try to avoid situations that provoke dread or otherwise cause them much distress. diagnosing social phobia social phobia is diagnosed when the fear or avoidance significantly interferes with normal, expected routines, or is excessively upsetting. social phobia disrupts normal life, interfering with career or social relationships. it often runs in families and may be accompanied by depression or alcoholism. social phobia often begins around early adolescence or even younger. approximately 15 million american adults ages 18 to 54 experience social phobia in a given year. treatment for social phobia people who suffer from social phobia often find relief from their symptoms when treated with cognitive - behavioral therapy, or medications, or a combination of the two. | agoraphobia | | what is agoraphobia? | agoraphobia is a greek word that literally means " fear of the marketplace


symptoms when treated with cognitive - behavioral therapy, or medications, or a combination of the two. | agoraphobia | | what is agoraphobia? | agoraphobia is a greek word that literally means " fear of the marketplace. " this anxiety disorder involves the fear of experiencing a panic attack in a place or situation from which escape may be difficult or embarrassing. the anxiety associated with agoraphobia is so severe that panic attacks are not unusual, and individuals with agoraphobia typically try to avoid the location or cause of their fear. agoraphobia involves fear of situations such as, but is not limited to, the following : - being alone outside his or her home - being at home alone - being in a crowd - traveling in a vehicle - being in an elevator or on a bridge people with agoraphobia typically avoid crowded places like streets, crowded stores, churches, and theaters. what are the characteristics of agoraphobia? most people with agoraphobia develop the disorder after first suffering a series of one or more panic attacks. the attacks occur randomly and without warning, and make it impossible for a person to predict what situations will trigger the reaction. this unpredictability of the panic causes the person to anticipate future panic attacks and, eventually, fear any situation in which an attack may occur. as a result, they avoid going into any place or situation where previous panic attacks have occurred. people with the disorder often become so disabled that they literally feel they cannot leave their homes. others who have agoraphobia, do go into potentially " phobic " situations, but only with great distress, or when accompanied by a trusted friend or family member. persons with agoraphobia may also develop depression, fatigue, tension, alcohol or drug abuse problems, and obsessive disorders, making seeking treatment crucial. approximately 1. 8 million american adults ages 18 to 54 experience agoraphobia in a given year. click here to view the online resources of mental health disorders


how would our lives be different if we could only buy foods native to new york state? this and similar questions are the focus of a museum - wide quest where students work in teams to gather data about the things they use each day. after collecting the data, each team creates a graphic representation of its findings and leads a discussion about interdependence around the globe. please divide your students into three different research teams and assign each team at least one chaperon or teacher. each team will be going to a separate area of the museum to gather data : the “ foods ” team will work in super kids market ; the “ fashions ” team in the museum ’ s collections ; and the “ fads ” team in timelab. after collecting data, each team will prepare a brief presentation to share its findings. all three groups will gather together for the presentations. lesson extensions for before or after your visit the following activities are designed for your class to enjoy before or after your museum visit. familiarizing students with the lesson concepts can enrich your museum experience. how do the choices we make reflect the concept of globalization? review maps of the united states and the world prior to your visit. here ’ s one way to do that : post the four cardinal directions in your room : north, south, east, and west. give each student an index card and the instruction to write the name of one of the 50 states on the card. when everyone is ready, ask students to stand where they think their state would be if the room was the u. s. allow students to make adjustments to their positions after talking with each other. provide a real map for students to use as a reference if needed. once in position, ask students to describe their thinking in deciding where to stand. do the same thing using continents, oceans, and countries with a map of the world. ask students to spend one week keeping a “ globalization journal. ” they should record each piece of evidence they see to suggest that globalization is occurring. this evidence may appear in items they have at home or have seen at stores ; things they ’ ve heard about in news stories ; music they listen to ; food they eat at restaurants ; holiday customs their family has adopted ; or other sources. some examples of what they might find include : - imported cheese in the grocery store - imported cds in a music store - a television program produced in another country - a television news story about international business or another topic related to globalization post a large map of the world in the classroom. invite students


recovery is a process, beginning with diagnosis and eventually moving into successful management of your illness. successful recovery involves learning about your illness and the treatments available, empowering yourself through the support of peers and family members, and finally moving to a point where you take action to manage your own illness by helping others. untreated mental illness : a needless human tragedy severe mental illnesses are treatable disorders of the brain. left untreated, however, they are among the most disabling and destructive illnesses known to humankind. millions of americans struggling with severe mental illnesses, such as schizophrenia, bipolar disorder, and major depression, know only too well the personal costs of these debilitating illnesses. stigma, shame, discrimination, unemployment, homelessness, criminalization, social isolation, poverty, and premature death mark the lives of most individuals with the most severe and persistent mental illnesses. mental illness recovery : a reality within our grasp the real tragedy of mental illness in this country is that we know how to put things right. we know how to give people back their lives, to give them back their self - respect, to help them become contributing members of our society. nami ' s in our own voice, a live presentation by consumers, offers living proof that recovery from mental illness is an ongoing reality. science has greatly expanded our understanding and treatment of severe mental illnesses. once forgotten in the back wards of mental institutions, individuals with brain disorders have a real chance at reclaiming full, productive lives, but only if they have access to the treatments, services, and programs so vital to recovery. - newer classes of medications can better treat individuals with severe mental illnesses and with far fewer side effects. eighty percent of those suffering from bipolar disorder and 65 percent of those with major depression respond quickly to treatment ; additionally, 60 percent of those with schizophrenia can be relieved of acute symptoms with proper medication. - assertive community treatment, a proven model treatment program that provides round - the - clock support to individuals with the most severe and persistent mental illnesses, significantly reduces hospitalizations, incarceration, homelessness, and increases employment, decent housing and quality of life. - the involvement of consumers and family members in all aspects of planning, organizing, financing, and implementing service - delivery systems results in more responsiveness and accountability, and far fewer grievances. resources for recovery


joined : 16 mar 2004 | posted : tue aug 04, 2009 2 : 40 pm post subject : immune responses jolted into action by nanohorns | the immune response triggered by carbon nanotube - like structures could be harnessed to help treat infectious diseases and cancers, say researchers. the way tiny structures like nanotubes can trigger sometimes severe immune reactions has troubled researchers trying to use them as vehicles to deliver drugs inside the body in a targeted way. white blood cells can efficiently detect and capture nanostructures, so much research is focused on allowing nanotubes and similar structures to pass unmolested in the body. but a french - italian research team plans to use nanohorns, a cone - shaped variety of carbon nanotubes, to deliberately provoke the immune system. they think that the usually unwelcome immune response could kick - start the body into fighting a disease or cancer more effectively. to test their theory, alberto bianco and helene dumortier at the cnrs institute in strasbourg, france, in collaboration with maurizio prato at the university of trieste, italy, gave carbon nanohorns to mouse white blood cells in a petri dish. the macrophage cells ' job is to swallow foreign particles. after 24 hours, most of the macrophages had swallowed some nanohorns. but they had also begun to release reactive oxygen compounds and other small molecules that signal to other parts of the immune system to become more active. the researchers think they could tune that cellular distress call to a particular disease or cancer, by filling the interior of nanohorns with particular antigens, like ice cream filling a cone. " the nanohorns would deliver the antigen to the macrophages while also triggering a cascade of pro - inflammatory effects, " dumortier says. " this process should initiate an antigen - specific immune response. " " there is still a long way to go before this interesting approach might become safe and effective, " says ruth duncan at cardiff university, uk. " safety would ultimately depend on proposed dose, the frequency of dose and the route of administration, " she says. dumortier agrees more work is needed, but adds that the results so far suggest that nanohorns are less toxic to cells than normal nanotubes can be. " no sign of cell death was visible upon three days of macrophage culture in the presence of nanohorns, " dumortier says. recent headline - grabbing results suggest that nanotubes


in this study, ni and cu nanowire arrays and ni / cu superlattice nanowire arrays are fabricated using standard techniques such as electrochemical deposition of metals into porous anodic alumina oxide templates having pore diameters of about 50 nm. we perform optical measurements on these nanowire array structures. optical reflectance ( or ) of the as - prepared samples is recorded using an imaging spectrometer in the wavelength range from 400 to 2, 000 nm ( i. e., from visible to near - infrared bandwidth ). the measurements are carried out at temperatures set to be 4. 2, 70, 150, and 200 k and at room temperature. we find that the intensity of the or spectrum for nanowire arrays depends strongly on the temperature. the strongest or can be observed at about t = 200 k for all samples in visible regime. the or spectra for these samples show different features in the visible and near - infrared bandwidths. we discuss the physical mechanisms responsible for these interesting experimental findings. this study is relevant to the application of metal nanowire arrays as optical and optoelectronic devices. keywords : nanowire array ; optical properties ; visible and near - infrared ; temperature dependence in recent years, quasi one - dimensional ( 1d ) nanostructured materials have received much attention attributed to their interesting physical properties in sharp contrast to the bulk ones and to the potential applications as electronic, magnetic, photonic, and optoelectronic devices [ 1 - 4 ]. from a viewpoint of physics, the basic physical properties of nanostructured materials differ significantly from those of bulk materials with the same chemical components. in particular, quantum confinement effects can be observed in the dimensionally reduced nanomaterial systems. therefore, nanowires have been a major focus of research on nanoscaled materials which can be taken as a fundamental building block of nanotechnology and practical nanodevices. it should be noticed that metal nanowires have displayed unique optical and optoelectronic properties due to surface plasmon resonance ( spr ) which is a resonant oscillation of the conducting electrons within the metallic nanostructures. the spr effect in nanowire structures can cause a tremendous enhancement of the electromagnetic near - field in the immediate vicinity of the particles and can give rise to enhanced scattering and absorption of light radiation. the spr in metal nanowires and related phenomena ( such as the surface - enhanced raman spectroscopy, nonlinear optic response, plas


- field in the immediate vicinity of the particles and can give rise to enhanced scattering and absorption of light radiation. the spr in metal nanowires and related phenomena ( such as the surface - enhanced raman spectroscopy, nonlinear optic response, plasmonic excitation, to mention but a few ) contributes greatly to their promising applications in biosensors, optical devices, and photonic and plasmonic devices [ 5 - 8 ]. moreover, metal nanowire wave guides can excite and emit terahertz ( 1012 hz or thz ) surface plasmon polaritons, which can fill the gap of terahertz electronics and optoelectronics. on the other hand, superlattice nanowires have even richer physical properties owing to further quantum confinement of electron motion along the wire direction. they have been proposed as advanced electronic device systems to observe novel effects such as giant magnetoresistance and even high thermoelectric figure of merit [ 10, 11 ]. furthermore, with the rapid development of nanotechnology, it is now possible to fabricate nanowire arrays and superlattice nanowire arrays [ 12, 13 ]. one of the major advantages to apply nanowire arrays and superlattice nanowire arrays as optic and optoelectronic devices is that the optical response of the array structures can be tuned and modulated via varying sample parameters such as the diameter of the wire and the pattern of the array structure. due to potential applications of the nanowire arrays and superlattice nanowire arrays as optical devices, it is of importance and significance to examine their basic optical properties. in this article, we present a detailed experimental study on the optical properties of three kinds of nanowire array structures such as ni and cu nanowire arrays and ni / cu superlattice nanowire arrays. we would like to examine how these advanced nanostructured material systems can respond to light radiation, how their optical properties depend on temperature and radiation wavelength, and why the optical properties of the nanowire arrays differ from those observed in bulk materials. samples and measurements in this study, three kinds of nanowire array structures are fabricated, including ni arrays, cu arrays, and ni / cu superlattice arrays. samples are prepared by direct current electrodeposition [ 14 - 16 ] of metal into the holes of porous anodic alumina membrane ( paam ) with the pore size of about 50 nm. noteworthy is the diameter


is used for the detection of 400 - to 800 - nm wavelength regime, and the ingaas photodetector is employed for the measurement of 1 - to 2 - μm wavelength regime. for measurements in the visible regime, the temperatures are set at 4. 2, 70, 150, and 200 k and at room temperature. the change of temperature is achieved in an oxford cooling system. the measurements in the near - infrared regime are undertaken at room temperature. results and discussion the or spectra for ni and cu nanowire arrays and ni / cu superlattice nanowire arrays are shown in figure 2 in visible bandwidth for different temperatures at 4. 2, 70, 150, 200, and 297 k, respectively. as can be seen, the intensity of or in nanowire array structures depends strongly on temperature. when temperature ( t ) < 200 k, the intensity of or for a ni nanowire array sample increases with temperature. when t > 200 k, the or intensity decreases with increasing temperature. the strongest or can be observed at about 200 k. a similar phenomenon can be found for a ni / cu superlattice nanowire array sample. in contrast, the or spectra for cu nanowire arrays ( see figure 2c ) show different temperature dependence. with increasing temperature, the intensity of or for a cu nanowire array first decreases in the 4. 2 - to 70 - k regime, then increases in the 70 - to 200 - k regime, and decreases again when t > 200 k. again, the strongest or for cu nanowire arrays can be observed at about t = 200 k. these experimental findings suggest that 200 k is an appropriate temperature for the enhancement of optical reflection from cu, ni, and ni / cu superlattice nanowire array structures. this can provide a basis for further investigation into other optical properties such as optical absorption and emission from metal nanowire arrays in visible regime. we find that when t > 200 k, the or spectrum for ni / cu superlattice nanowire array lies between those for cu and ni nanowire arrays. however, at lower temperatures ( e. g., at 150 k ), the intensity of the or spectrum for ni / cu superlattice nanowire array is lower than those for cu and ni nanowire arrays. figure 2. the spectra of optical reflection for nanowire arrays measured at different temperatures of 4. 2, 70, 150, 200, and 297 k as indicated. the results for a ni nanowire array ( a ), a


nanowire arrays. figure 2. the spectra of optical reflection for nanowire arrays measured at different temperatures of 4. 2, 70, 150, 200, and 297 k as indicated. the results for a ni nanowire array ( a ), a ni / cu superlattice nanowire array ( b ), and a cu nanowire array ( c ) are shown. in figure 3, the or spectra are shown at room temperature for three metal nanowire array samples in visible and near - infrared bandwidths. in the visible regime ( see figure 3a ), two relatively wide reflection peaks can be observed for all samples at about 500 to 650 nm and 650 to 700 nm, respectively. the 650 - to 700 - nm peaks for the three samples appear at almost the same position ( at about 667 nm ), while the 500 - to 650 - nm ones redshift slightly with respect to that of the incident light source. the peak position of the light source is at about 554 nm, whereas the peaks for cu and ni / cu superlattice nanowire arrays are at about 585 nm and that for ni nanowire arrays is at about 600 nm. it should be noted that the visible light source provided by the tungsten halogen lamp has two main peaks in the 400 - to 800 - nm wavelength regime. the intensity of infrared light source given by the si carbide rod decreases when the radiation wavelength approaches 2 μm. the variation of the intensity of the light sources is enhanced via measurement systems. we notice that ni nanowire arrays reflect more strongly the visible light ; cu nanowire arrays reflect relatively weakly, and the or spectrum for ni / cu superlattice nanowire arrays is just in between them. in the near - infrared range of 1, 000 to 2, 000 nm ( see figure 3b ), the peaks of or spectra for cu nanowire arrays and ni / cu superlattice nanowire arrays are at about 1, 808 nm, and ni nanowire arrays and light source are at about 1, 727 nm. the or spectra for nanowire arrays redshift slightly with respect to the spectrum of the light source. in contrast to the visible regime, the cu nanowire array reflects more strongly the infrared radiation than ni nanowire array. interestingly, the or spectrum for ni / cu superlattice nanowire array is below that for ni nanowire array when radiation wavelength is less than 1, 730 nm, and it is located in between the or spectra for ni


arrays do. because the quantum confinement effect affects mainly the electronic states in different bands in the array structure, the main features of or due to interband electronic transition does not change very significantly. this is why ni nanowire arrays can reflect more strongly the visible radiation than cu arrays can, as shown in figure 3a and similar to the case for bulk materials. moreover, our results show that in the visible regime and when t > 200 k, the or spectrum for ni / cu superlattice nanowire arrays lies between those for cu and ni nanowire arrays. however, at relatively lower temperatures ( e. g., at 150 k ), the intensity of the or spectrum for ni / cu superlattice nanowire array is lower than those for cu and ni nanowire arrays. we believe that this may have resulted from different features of the phonon modes and electron - phonon scattering in nanowire and superlattice nanowire structures. in superlattice nanowire systems formed by different host materials, the phonon modes can be quantized and the conducting electrons are confined along the wire direction. the quantized phonon modes can weaken the electron - phonon scattering because a scattering event requires momentum and energy conservation. on the other hand, the localized electrons can interact more strongly with phonons. our results suggest that when t > 200 k, the former case is dominant, and when t 150 k, the latter effect is stronger. in this study, cu, ni, and ni / cu nanowire arrays have been fabricated using state - of - the - art nanotechnology. the optical measurements on these nanowire arrays have been carried out in visible and near - infrared bandwidths for different temperatures. we have found that the optical reflection spectra of these samples depend strongly on temperature and on radiation wavelength. in particular, ( 1 ) the strongest or in the visible regime can be observed at about 200 k for all samples, and ( 2 ) the or for cu nanowire arrays show a different dependence on temperature and radiation wavelength from that for ni nanowire arrays. these results indicate that the surface plasmon resonances induced by inter - and intraband electronic transitions, the electron - phonon interaction, and the quantum confinement effect can play important roles in affecting optical properties of the metal nanowire array structure. we hope that the interesting experimental findings from this study can provide an in - depth understanding of optical properties of cu and ni nanowire arrays and cu / ni superlattice nano


important roles in affecting optical properties of the metal nanowire array structure. we hope that the interesting experimental findings from this study can provide an in - depth understanding of optical properties of cu and ni nanowire arrays and cu / ni superlattice nanowire arrays and can provide a physical base for the application of metal nanowire arrays as advanced optical and optoelectronic devices. the authors declare that they have no competing interests. wx proposed the research work, coordinated the collaboration, and carried out the analyses of experimental results. yyz designed the experiment and experimental setup, carried out the measurements, and drafted the manuscript. shx and gtf fabricated the nanowire and superlattice nanowire array samples. ymx and jgh participated in experimental measurements, results and discussion, and analyses. all authors read and approved the final manuscript. this work was supported by the national natural science foundation of china ( grant no. 10974206 ), department of science and technology of yunnan province, and by the chinese academy of sciences. j crystal growth 2003, 254 : 14. publisher full text j appl phys 2002, 91 : 4590 - 4594. publisher full text appl surf sci 2008, 255 : 1901. publisher full text surf coat technol 2010, 205 : 2432 - 2437. publisher full text c r physique 2008, 9 : 215 - 231. publisher full text appl phys lett 1994, 65 : 2484. publisher full text appl phys lett 1994, 65 : 3019. publisher full text nano lett 2002, 2 : 83. publisher full text


assists the reader to follow the line of argument | | the production of grammatically correct, structurally sound and meaningful sentences | | the use of correct and appropriate punctuation to aid the reading of the text | | the accuracy of spelling and the difficulty of the words used the narrative writing marking guide ( used in 2008 - 2010 ) is also available. use of formulaic structures beginning writers can benefit from being taught how to use structured scaffolds. one such scaffold that is commonly used is the five paragraph argument essay. however, when students becomes more competent, the use of this structure can be limiting. as writers develop their capabilities they should be encouraged to move away from formulaic structures and to use a variety of different persuasive text types, styles and language features, as appropriate to different topics. students are required to write their opinion and to draw on personal knowledge and experience when responding to test topics. students are not expected to have detailed knowledge about the topic. students should feel free to use any knowledge that they have on the topic, but should not feel the need to manufacture evidence to support their argument. in fact, students who do so may undermine the credibility of their argument by making statements that are implausible. example topics and different styles : city or country ( see example prompt ) a beginning writer could write their opinion about living in either the city or country and give reasons for it. a more capable writer might also choose to take one side and argue for it. however, this topic also lends itself to a comparative style response from a more capable writer. it can be argued there are benefits and limitations to living in the city and living in the country. a writer could also choose to introduce other options, for example living in a large country town that might have the benefits of city and rural life. positions taken on this topic are likely to elicit logical, practical reasons and anecdotes based on writers ’ experiences. books or tv ( see example prompt ) a beginning writer could write about their opinion of one aspect and give reasons for it. however, this topic lends itself to a comparative style response from a more capable writer. it can be argued there are benefits and limitations to both books and tv. the reasons for either side of the topic are likely to elicit logical, practical reasons and personal anecdotes based on the writer ' s experiences of both books and tv. it is cruel to keep animals in cages and zoos ( see example prompt ) a beginning writer could take on one side


atomic oxygen, a corrosive space gas, finds many applications on earth. an atomic innovation for artwork oxygen may be one of the most common substances on the planet, but recent space research has unveiled a surprising number of new applications for the gas, including restoring damaged artwork. it all started with a critical problem facing would - be spacecraft : the gasses just outside the earth ’ s atmosphere are highly corrosive. while most oxygen atoms on earth ’ s surface occur in pairs, in space the pair is often split apart by short - wave solar radiation, producing singular atoms. because oxygen so easily bonds with other substances, it is highly corrosive in atomic form, and it gradually wears away the protective layering on orbiting objects such as satellites and the international space station ( iss ). to combat this destructive gas, nasa recreated it on earth and applied it to different materials to see what would prove most resistant. the coatings developed through these experiments are currently used on the iss. during the tests, however, scientists also discovered applications for atomic oxygen that have since proved a success in the private sector. breathing new life into damaged art in their experiments, nasa researchers quickly realized that atomic oxygen interacted primarily with organic materials. soon after, they partnered with churches and museums to test the gas ’ s ability to restore fire - damaged or vandalized art. atomic oxygen was able to remove soot from fire - damaged artworks without altering the paint. it was first tested on oil paintings : in 1989, an arson fire at st. alban ’ s episcopal church in cleveland nearly destroyed a painting of mary magdalene. although the paint was blistered and charred, atomic oxygen treatment plus a reapplication of varnish revitalized it. and in 2002, a fire at st. stanislaus church ( also in cleveland ) left two paintings with soot damage, but atomic oxygen removed it. buoyed by the successes with oil paints, the engineers also applied the restoration technique to acrylics, watercolors, and ink. at pittsburgh ’ s carnegie museum of art, where an andy warhol painting, bathtub, has been kissed by a lipstick - wearing vandal, a technician successfully removed the offending pink mark with a portable atomic oxygen gun. the only evidence that the painting had been treated — a lightened spot of paint — was easily restored by a conservator. a genuine difference - maker when the successes in art restoration were publicized, forensic analysts who study documents became curious about using atomic oxygen to detect forge


is light made of waves, or particles? this fundamental question has dogged scientists for decades, because light seems to be both. however, until now, experiments have revealed light to act either like a particle, or a wave, but never the two at once. now, for the first time, a new type of experiment has shown light behaving like both a particle and a wave simultaneously, providing a new dimension to the quandary that could help reveal the true nature of light, and of the whole quantum world. the debate goes back at least as far as isaac newton, who advocated that light was made of particles, and james clerk maxwell, whose successful theory of electromagnetism, unifying the forces of electricity and magnetism into one, relied on a model of light as a wave. then in 1905, albert einstein explained a phenomenon called the photoelectric effect using the idea that light was made of particles called photons ( this discovery won him the nobel prize in physics ). [ what ' s that? your physics questions answered ] ultimately, there ' s good reason to think that light is both a particle and a wave. in fact, the same seems to be true of all subatomic particles, including electrons and quarks and even the recently discovered higgs boson - like particle. the idea is called wave - particle duality, and is a fundamental tenet of the theory of quantum mechanics. depending on which type of experiment is used, light, or any other type of particle, will behave like a particle or like a wave. so far, both aspects of light ' s nature haven ' t been observed at the same time. but still, scientists have wondered, does light switch from being a particle to being a wave depending on the circumstance? or is light always both a particle and a wave simultaneously? now, for the first time, researchers have devised a new type of measurement apparatus that can detect both particle and wave - like behavior at the same time. the device relies on a strange quantum effect called quantum nonlocality, a counter - intuitive notion that boils down to the idea that the same particle can exist in two locations at once. " the measurement apparatus detected strong nonlocality, which certified that the photon behaved simultaneously as a wave and a particle in our experiment, " physicist alberto peruzzo of england ' s university of bristol said in a statement. " this represents a strong refutation of models in which the photon is either a wave or a particle. " peruzzo


a wave and a particle in our experiment, " physicist alberto peruzzo of england ' s university of bristol said in a statement. " this represents a strong refutation of models in which the photon is either a wave or a particle. " peruzzo is lead author of a paper describing the experiment published in the nov. 2 issue of the journal science. the experiment further relies on another weird aspect of quantum mechanics — the idea of quantum entanglement. two particles can become entangled so that actions performed on one particle affect the other. in this way, the researchers were able to allow the photons in the experiment to delay the choice of whether to be particles or waves. mit physicist seth lloyd, who was not involved in the project, called the experiment " audacious " in a related essay in science, and said that while it allowed the photons to delay the choice of being particles or waves for only a few nanoseconds, " if one has access to quantum memory in which to store the entanglement, the decision could be put off until tomorrow ( or for as long as the memory works reliably ). so why decide now? just let those quanta slide! " - twisted physics : 7 mind - blowing findings - quantum weirdness goes big – molecules act like waves | video - wacky physics : the coolest little particles in nature © 2012 livescience. com. all rights reserved.


dementia and the sniff magnitude test sniff test may signal disorders ’ early stages by elizabeth svoboda published : august 14, 2007 the sniff magnitude test, developed with the aid of a $ 1. 3 million grant from the national institutes of health, consists of a nasal tube called a cannula attached to a plastic container about the size and shape of a coffee thermos. chemical vapors inside the canister are released through the tube, exposing subjects to a series of smells, some more objectionable than others. “ people describe some of the smells as skunky or sewerlike, ” said jason bailie, a university of cincinnati graduate student working on the test. “ there ’ s also one that smells like banana. ” as patients take whiffs of each new fragrance, sensors in the thermos unit measure the negative pressure the inhalations produce. the size and intensity of these sniffs turn out to be important gauges of olfactory ability. after detecting a strong or disagreeable odor, people with a normal sense of smell take very small sniffs to avoid smelling it. subjects with an impaired sense of smell, on the other hand, continue taking deep whiffs, because the scent does not register in their brains. the cincinnati team ’ s efforts have piqued the interest of other researchers, including dr. doty and alan hirsch of the smell and taste research and treatment foundation, who is using the sniff test in his clinical practice. “ they ’ ve chosen some very good odors that stimulate the olfactory system effectively, ” dr. doty said. “ this is a very novel approach — it just needs to be tested more broadly. ” still, dr. doty added, the sniff magnitude test may not be the ideal way to assess every patient with cognitive deficits. “ very early in life, we make a connection between an odor and its source, ” he said. “ we give it a name. if the connection between the name of an odor and the odor itself is what ’ s breaking down in an alzheimer ’ s patient, this test might not be as helpful, ” because it does not tell evaluators how a patient identifies and categorizes smells. the sniff magnitude test is likely to raise red flags only if an impending cognitive disorder directly affects a patient ’ s olfactory abilities. [... read the full article... ]


suddenly on march 24, 1877 in his home in langport, somerset, england, at the age of 51. bagehot was a person with a whole variety of interests. he wrote on the topics of economics, politics, law, literature, and so forth. he remains most famous however for his three books : the english constitution ( 1867 ), physics and politics ( 1872 ), and lombard street ( 1873 ). in addition to these volumes, he commanded substantial influence through his editorship of the economist. the english constitution in 1867, bagehot wrote the english constitution which explored the constitution of the united kingdom, specifically the functioning of the british parliament and the british monarchy, and the contrasts between british and american government. bagehot revealed how the parliament operated as it were " behind a curtain, " hidden from public knowledge. he divided the constitution into two components : - the dignified – symbolic side of the constitution, and - the efficient - the real face of the constitution, the way things actually work and get done. instead of describing the constitution from the point of the law, as a lawyer would, bagehot focused on the practical implications of the constitution, as experienced by the common man. the book soon became widely popular, ensuring bagehot worldwide fame. he criticized american presidential system, claiming that it lacked flexibility and accountability. while in the english parliament real debates took place, after which changes could take place, in the american congress debates had no power, since the president made the final decision. in bagehot ' s view : a parliamentary system educates the public, while a presidential system corrupts it. ( the english constitution 1867 ) he also criticized the way american presidents are chosen, saying : under a presidential constitution the preliminary caucuses that choose the president need not care as to the ultimate fitness of the man they choose. they are solely concerned with his attractiveness as a candidate. ( the english constitution, 1867 ) physics and politics bagehot wrote physics and politics in 1872, in which he tried to apply the principles of evolution to human societies. the subtitle of the book reads : thoughts on the application of the principles of " natural selection " and " inheritance " to political society. the book represented a pioneering effort to make a relationship between the natural and the social sciences. bagehot explained the functioning of the market, and how it affects the behavior of the people. for example, he believed that people tend to invest money when the mood of the market is positive, and restrain from it when


and the social sciences. bagehot explained the functioning of the market, and how it affects the behavior of the people. for example, he believed that people tend to invest money when the mood of the market is positive, and restrain from it when it comes to a negative phase. in this book bagehot also reflected on the psychology of politics, especially on the personality of a leader. he stressed two things as essential for leadership : the personality of a leader and his motivation. bagehot believed that motivation played one of the key roles in good leadership, and that the personality of a leader often counted more than the policy he endorsed : it is the life of teachers which is catching, not their tenets. ” ( physics and politics 1872 ) bagehot claimed that the personal example of the leader sets the tone for the whole governance. that is why “ character issues ” are so important for any government. character " issues " still play an important role in deciding the potential candidate for any leadership position in today ’ s modern world. bagehot coined the expression " the cake of custom, " denoting the sets of customs that any society is rooted in. bagehot believed that customs develop and evolve throughout human history, with the best organized groups overthrowing the poorly organized groups. in this sense bagehot ’ s views are a clear example of cultural selection, closer to lamarckian than darwinian evolution. the central problem in his book was to understand why europeans could break away from tradition and “ the cake of custom ” and instead focus on progress and novelty. he saw tradition as important in keeping societies cohesive, but also believed that diversity was essential for progress : the great difficulty which history records is not that of the first step, but that of the second step. what is most evident is not the difficulty of getting a fixed law, but getting out of a fixed law ; not of cementing ( as upon a former occasion i phrased it ) a cake of custom, but of breaking the cake of custom ; not of making the first preservative habit, but of breaking through it, and reaching something better. ( physics and politics 1872 ) in his famous lombard street ( 1873 ), bagehot explained the theory behind the banking system, using insights from the english money market. as with his analysis of the english constitution six years earlier, bagehot described the english banking system through the eyes of a simple person, as experienced in everyday life. bagehot showed that the english money system was solely relying


english money market. as with his analysis of the english constitution six years earlier, bagehot described the english banking system through the eyes of a simple person, as experienced in everyday life. bagehot showed that the english money system was solely relying on the central bank, the bank of england. bagehot had warned that the whole reserve was in the central bank, under no effectual penalty of failure. he proposed several ideas how to improve that system. bagehot ’ s work can be closely associated with the english historicist tradition. he did not directly oppose classical economics, but advocated for its reorganization. he claimed that economics needed to incorporate more factors in its theory, such as cultural and social factors, in order to be more accurate in theorizing about economic processes. bagehot was one of the first to study the relationship between physical and social sciences from a sociological perspective. in his contributions to sociological theory through historical studies, bagehot may be compared to his contemporary henry maine. he also developed a distinct theory of central banking, many points of which continue to be valued. with his analysis of english and united states political systems in the english constitution, bagehot influenced woodrow wilson to write his congressional government. in honor of his achievements and his work as its editor, the economist named its weekly column on british politics after him. every year the british political studies association awards the walter bagehot prize for the best dissertation in the field of government and public administration. - bagehot, walter. 1848. review of mill ' s principles of political economy. prospective review, 4 ( 16 ), 460 - 502. - bagehot, walter. 1858. estimates of some englishmen and scotchmen. london : chapman and hall. - bagehot, walter. 1875. a new standard of value. the economist, november 20. - bagehot, walter. 1879. literary studies. london : longmans, green and co. - bagehot, walter. 1998. ( original 1880 ). economic studies. augustus m kelley pubs. isbn 0678008523 - bagehot, walter. 2001. ( original 1867 ). the english constitution. oxford university press. isbn 0192839756 - bagehot, walter. 2001. ( original 1873 ). lombard street : a description of the money market. adamant media corporation. isbn 140210006x - bagehot, walter. 2001. ( original 1877 ). some articles on the depreciation of


coastal clash : defining public property and the history of the public trust doctrine " coastal clash " is a one - hour documentary focusing on the urbanization of california ' s coastline. the activities and lesson plans for the film " coastal clash " target students at the high school level and align with the california state standards for government. in this lesson plan, students will do research and group work related to the concept of the public trust doctrine. enhancing modern languages teaching : student participation and motivation enhancing modern languages teaching : student participation and motivation the icarus syndrome : a history of american hubris the icarus syndrome tells a tale as old as the greek – a story about the seductions of success. in conversation with associate professor brendan o ' connor from the us studies centre, peter beinart portrays three extraordinary generations : the progressives... ( running time 60 : 06 ) oberlin history as american history this site offers exhibits that tell about the lives and histories of the people of oberlin, ohio. the website features the story of an amistad captive, oberlin women and the struggle for equality, and the city ' s cooperative tradition. it also includes city maps and pictures, letters and essays related to the city ' s founding and development, newspaper articles regarding the niagara movement, and census data. ancient and medieval philosophy, fall 2006 this course will concentrate on major figures and persistent themes in ancient and medieval philosophy. a balance will be sought between scope and depth, the latter ensured by a close reading of selected texts. ancient wisdom and modern love, spring 2007 built around plato ' s symposium, shakespeare ( including a midsummer night ' s dream ), catholic writings ( including humanae vitae ), and several movies, this course explores the nature of romance and erotic love. we will examine such topics as sexuality, marriage, and procreation with an eye towards how we can be better at being in love. the course generally tries to integrate the analytic approach of philosophy with the imaginative approach of literature. medicine and public health in american history, fall 2007 this course offers an introduction to differing conceptions of disease, health, and healing throughout american history, the changing role and image of medicine and medical professionals in american life, and the changing social and cultural meanings and entanglements of medical science and practice throughout american history. creating people centred schools : section two, school organization : a brief history this provides an overview of organizational styles and the importance of cultures as well as structures in organizational models and change. welsh history and its sources this unit is a teaching and


the caribbean. the site, launched in january 2010, provides a virtual archive of over 200 primary sources along with introductions based on the latest scholarly findings. " according to the site, it " is organized into topics that are organized approximately chronologically, but each one stands alone. the archive, or database of primary sources, is designed in a modular fashion, so viewers from east asia in world history this site is designed as a resource site for teachers of world history, world geography, and world cultures. it provides background information and curriculum materials, including primary source documents for students. the material is arranged in 14 topic sections. the topics and the historical periods into which they are divided follow the national standards in world history and the content outline for the advanced placement course in world history. seventeen moments in soviet history begins with the bolshevik seizure of power in 1917 & ends with the dissolution of the soviet union in 1991. it includes the kronstadt uprising ( 1921 ), the death of lenin ( 1924 ), the liquidation of the kulaks as a class ( 1929 ), the year of the stakhanovite ( 1936 ), the end of rationing ( 1947 ), the virgin lands campaign ( 1954 ), khrushchev ' s secret speech ( 1956 ), the first cosmonaut ( 1961 ), the intervention in czechoslovakia ( 1968 ), & chernobyl ( 1986 ). ( neh ) the mongols in world history a sophisticated web site on the history and impact of the mongols. separate pages deal with such topics as the nature of nomadic life, key figures, the mongol conquests, and the impact of the mongols on china and the world. an image gallery and set of historical maps as well as other class materials and readings add to the value of the site. that one of the leading experts on the mongols, morris rosabe, was a consultant gives the site much creditability. a radically modern approach to introductory physics volume 2 this is the second part ( chapters 13 - 24 ) of a pdf textbook for a one - year introductory physics course. the text was developed out of an alternate beginning physics course at new mexico tech designed for students with a strong interest in physics. a broad outline of the text is as follows : newton ' s law of gravitation ; forces in relativity ; electromagnetic forces ; generation of electromagnetic fields ; capacitors, inductors, and resistors ; measuring the very small ; atoms ; the standard mode ; atomic mactutor history of mathematics archive an award - winning site concerning the history of


ice core gateway : vostok ice core co2 data the vostok ice core has a long record of global carbon dioxide concentrations, with variations caused by factors other than photosynthesis and human activity. ice core data sets from three different authors are available for download. users can also link to other noaa paleoclimate projects and information. phases of the moon this site contains a series of visualizations of the sun, moon and earth system and how they relate to the changing face of the moon. animations are in the form of java applets, forms for field observation of the moon, and a collection of exercises and pdf versions of background material. there are practice questions and quizzes that discuss the animations. planetary climate exercise this ms word document explains roles for a planetary climate role - playing exercise dealing with the atmospheres of venus and the earth. roles include experts on coal, carbon dioxide, heat balance, spectroscopy, atmospheric transmission and the water cycle. starting out with earth history this activity asks students to place 6 - 10 events in earth history on a timeline, first working in small groups and then as a class. then, through questions, important points such as how certain events are dated, where humanity fits in, and so forth, can be brought up. the starting point website builds a context for the exercise by detailing the learning goals, teaching notes and materials ( downloadable ), and additional resources. japan ' s nuclear policy ambassador ryukichi imai - journalist, nuclear engineer, and general manager at japan atomic power company - was japanese ambassador to the united nations disarmament conference from 1982 to 1987. in this video segment, imai explains why he believes that japan will never embark on a nuclear - weapons program. he also predicts that, while japan stands alone in its reliance on nuclear energy, rising energy prices - even post - chernobyl - will revive worldwide interest in nuclear power. in the interview he co from mutual assured destruction to star wars caspar weinberger served as u. s. president ronald reagan ' s secretary of defense from 1981 to 1987. in this video segment, weinberger explains how deployment of the mx missile stopped the soviet union from believing it could successfully launch a first strike, which he feels is ' the essence of deterrence. ' a better alternative to ' mutual assured destruction, ' he argues, is the strategic defense initiative, the reagan administration ' s hotly contested proposal to design space - based weapons that cou bruce kent, ordained a catholic minister in 1958, became general secretary


la ltima investigacin de nasa con la instruccin. pasados asuntos incluyen buck rogers, cuidado!, adis a la mir, despus de tres intentos, se retira la nia?, y ms. robotics with the xbc controller this course offers a brief history of robotics, and a definition of robot and robotics. the course includes an introduction to ic and the xbc, downloading firmware, updating the bitstream, and ic environment and simulator. it concludes with an activity building a demo - bot. earth ' s magnetic field the poetry website explores solar storms and how they affect us, space weather, and the northern lights. a 64 - page workbook of hands - on activities examines earth ' s magnetosphere. create a classroom magnetometer. solve the space science problem of the week. foilsim : basic aerodynamics software this is an interactive simulation software that determines the airflow around various shapes of airfoils. this is is a primer on scientific efforts to understand the origin, evolution, and fate of the universe. among the questions it explores : what types of matter and energy fill the universe? what is the age and shape of the universe? how rapidly is it expanding? the website examines the big bang theory, as well as tests and limitations of the theory. center for educational resources ( ceres ) project this is an extensive library of on - line and interactive k - 12 science education materials for teaching astronomy. the site contains both classroom science projects and reference materials.


biomass technology analysis conducting full life - cycle assessments for biomass products, including electricity, biodiesel, and ethanol, is important for determining environmental benefits. nrel analysts use a life - cycle inventory modeling package and supporting databases to conduct life - cycle assessments. these tools can be applied on a global, regional, local, or project basis. integrated system analyses, technoeconomic analyses, life - cycle assessments ( lcas ), and other analysis tools are essential to our research and development efforts. they provide an understanding of the economic, technical, and even global impacts of renewable technologies. these analyses also provide direction, focus, and support to the development and commercialization of various biomass conversion technologies. the economic feasibility and environmental benefits of biomass technologies revealed by these analyses are useful for the government, regulators, and the private sector. technoeconomic analyses ( teas ) are performed to determine the potential economic viability of a research process. evaluating the costs of a given process compared to the current technology can assess the economic feasibility of a project. these analyses can be useful in determining which emerging technologies have the highest potential for near -, mid -, and long - term success. the results of a tea are also useful in directing research toward areas in which improvements will result in the greatest cost reductions. as the economics of a process are evaluated throughout the life of the project, advancement toward the final goal of commercialization can be measured. teas performed in previous years have determined the technical and economic feasibility of various biomass - based systems, including : - direct combustion - gasification combined cycle power systems nrel ' s analysis capabilities include proficiency with the following software packages : | aspen plus© | | models continuous processes to obtain material and energy balances | | gatecycle™ | | performs detailed steady - state and off - design analyses of thermal power systems | | questimate© | | performs detailed process plant cost estimates | | matlab® and mathcad® | | perform numeric calculations and mathematical solutions | | crystal ball® | | operates within microsoft excel® and incorporates uncertainties in forecasting analysis results | life - cycle assessment ( lca ) is an analytic method for identifying, evaluating, and minimizing the environmental impacts of emissions and resource depletion associated with a specific process. when such an assessment is performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. material and energy balances are used to quantify the emissions, resource depletion, and energy consumption


is performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. material and energy balances are used to quantify the emissions, resource depletion, and energy consumption of all processes, including raw material extraction, processing, and final disposal of products and by - products, required to make the process of interest operate. the results of this inventory are then used to evaluate the environmental impacts of the process so efforts can focus on mitigation. lca studies have been conducted on the following systems : - biomass - fired integrated gasification combined - cycle system using a biomass energy crop - pulverized coal boiler representing an average u. s. coal - fired power plant - cofiring biomass residue with coal - natural gas combined - cycle power plant - direct - fired biomass power plant using biomass residue - anaerobic digestion of animal waste biofuels production technologies : - ethanol from corn stover - comparison of biodiesel and petroleum diesel used in an urban bus hydrogen production technologies : - natural gas - hydrogen production for these analyses, the software package used to track the material and energy flows between the process blocks in each system was tools for environmental analysis and management ( team® ). learn more about our biomass capabilities and current projects in this area. access more information on all of our staff analysts


algorithm positions solar trackers, movie stars march 30, 2011 math and programming experts at a federal laboratory took an algorithm used to track the stars and rewrote its code to precisely follow the sun, even taking into consideration the vagaries of the occasional leap second. now, the algorithm and its software are helping solar power manufacturers build more precise trackers, orchards to keep their apples spotless and movie makers to keep the shadows off movie stars. the solar position algorithm ( spa ) was developed at the u. s. department of energy ' s national renewable energy laboratory to calculate the sun ' s position with unmatched low uncertainty of + / - 0. 0003 degrees at vertex, in the period of years from - 2000 to 6000 ( or 2001 b. c. until just short of 4, 000 years from now ). that ' s more than 30 times more precise than the uncertainty levels for all other algorithms used in solar energy applications, which claim no better than + / - 0. 01 degrees, and are only valid for a maximum of 50 years. and those uncertainty claims cannot be validated because of the need to add an occasional leap second because of the randomly increasing length of the mean solar day. the spa does account for the leap second. that difference in uncertainty levels is no small change, because an error of. 01 degrees at noon can throw calculations off by 2 or 3 percent at sunrise or sunset, said nrel senior scientist ibrahim reda, the leader on the project. " every uncertainty of 1 percent in the energy budget is millions of dollars uncertainty for utility companies and bankers, " reda said. " accuracy is translated into dollars. when you can be more accurate, you save a lot of money. " " siemens industry inc. uses nrel ' s spa in its newest and smallest s7 - 1200 compact controller, " says paul ruland of siemens industry, inc. " siemens took that very complex calculation, systemized it into our code and made a usable function block that its customers can use with their particular technologies to track the sun in the most efficient way. the end result is a 30 percent increase in accuracy compared to other technologies. " science, engineering and math all add to breakthroughs an algorithm is a set of rules for solving a mathematical problem in a finite number of steps, even though those steps can number in the hundreds or thousands. nrel is known more for its solar, wind, and biofuel researchers than for its work in advanced math. but algorithms are key to so many scientific


a finite number of steps, even though those steps can number in the hundreds or thousands. nrel is known more for its solar, wind, and biofuel researchers than for its work in advanced math. but algorithms are key to so many scientific and technological breakthroughs today that a scientist well - versed in the math of algorithms is behind many of nrel ' s big innovations. since spa was published on nrel ' s website, more than 4, 000 users from around the world have downloaded it. in the european union, for the past three years, it has been the reference algorithm to calculate the sun ' s position both for solar energy and atmospheric science applications. it has been licensed to, and downloaded by, major u. s. manufacturers of sun trackers, military equipment and cell phones. it has been used to boost agriculture and to help forecast the weather. archaeologists, universities and religious organizations have employed spa, as have other national laboratories. fewer dropped cell - phone calls billions of cell - phone calls are made each day, and they stay connected only because algorithms help determine exactly when to switch signals from one satellite to another. cell - phone companies can use the spa to know exactly the moments when the phone, satellite, and the bothersome sun are in the same alignment, vulnerable to disconnections or lost calls. " the cell phone guys use spa to know the specific moment to switch to another satellite so you ' re not disconnected, " said reda, who has a master ' s degree in electrical engineering / measurement from the university of colorado. " think of how many millions of people would be disconnected if there ' s too much uncertainty about the sun ' s position. " from a tool for solar scientists to widespread uses spa sprang from nrel ' s need to calibrate solar measuring instruments at its solar radiation research laboratory. " we characterize the instruments based on the solar angle, " reda said. " it ' s vital that instruments get a precise read on the amount of energy they are getting from the sun at precise solar angle. " that will become even more critical in the future when utilities add more energy garnered from the sun to the smart grid. " the smart grid has to know precisely what your budget is for each resource you are using — oil, coal, solar, wind, " reda said. making an astronomy algorithm one for the sun reda borrowed from the " astronomical algorithms, " which is based on the variations seculaires des orbites planetaires theory ( vsop8


slowing down, meaning the solar day is getting just a tiny bit longer. but it ' s not doing so at a constant rate. " it happens in unpredictable ways, " reda said. sometimes a leap second is added every year ; sometimes there isn ' t a need for another leap second for three or four years. for example, the international earth rotation and reference systems service ( iers ) added six leap seconds over the course of seven years between 1992 and 1998, but has added just one extra second since 2006. the algorithm calculates exactly when to add a leap second because included in its equations are rapid, monthly, and long - term data on the solar day provided by iers, reda and andreas said. " iers receives the data from many observatories around the world, " reda added. " each observatory has its own measuring instruments to measure the earth ' s rotation. a consensus correction is then calculated for the fraction of second. as long as we know the time, and how much the earth ' s rotation has slowed, we know the sun ' s position precisely. " that precision has proved useful in unexpected fields. practical uses in agriculture, movie making one person who bought a license for the spa software has an apple orchard, and wanted to keep the black spots off the apples that turn off finicky consumers, thus making wholesale buyers hesitate, reda said. the black spots appear when too much sun hits a particular apple, a particular tree or a particular row of trees in an orchard. the spots can be prevented by showering the apples with water, but growers don ' t want to use more water than necessary. spa ' s precise tracking of the sun tells the grower exactly when the automatic sprinkler should spray for a few moments on a particular set of trees, and when it ' s ok to shut off that sprayer and turn on the next one. spa communicates with the sprinkler system so, " instead of spraying the whole orchard, the spray moves minute by minute, " reda said. " he takes our tool and plugs it into the software that controls the sprinkler system. and he saves a lot of water. " religious groups with traditions of praying at a particular time of day even have turned to spa to help with precision. a movie - camera manufacturer has purchased the spa software to help cinematographers combat the precious waste of money when shadows disrupt outdoor shooting. " they have cameras on those big cranes and booms, and typically


tuberculosis ( tb ) is a chronic bacterial infection that usually infects the lungs, although other organs such as the kidneys, spine, or brain are sometimes involved. tb is primarily an airborne disease. there is a difference between being infected with the tb bacterium and having active tuberculosis disease. there are three important ways to describe the stages of tb. they are as follows : - exposure. this occurs when a person has been in contact with, or exposed to, another person who is thought to have or does have tb. the exposed person will have a negative skin test, a normal chest x - ray, and no signs or symptoms of the disease. - latent tb infection. this occurs when a person has the tb bacteria in his or her body, but does not have symptoms of the disease. the infected person ' s immune system walls off the tb organisms, and they remain dormant throughout life in 90 percent of people who are infected. this person would have a positive skin test but a normal chest x - ray. - tb disease. this describes the person who has signs and symptoms of an active infection. the person would have a positive skin test and a positive chest x - ray. the predominant tb bacterium is mycobacterium tuberculosis ( m. tuberculosis ). many people infected with m. tuberculosis never develop active tb and remain in the latent tb stage. however, in people with weakened immune systems, especially those with hiv ( human immunodeficiency virus ), tb organisms can overcome the body ' s defenses, multiply, and cause an active disease. tb affects all ages, races, income levels, and both genders. those at higher risk include the following : - people who live or work with others who have tb - medically underserved populations - homeless people - people from other countries where tb is prevalent - people in group settings, such as nursing homes - people who abuse alcohol - people who use intravenous drugs - people with impaired immune systems - the elderly - health care workers who come in contact with high - risk populations the following are the most common symptoms of active tb. however, each individual may experience symptoms differently. - cough that will not go away - chest pain - loss of appetite - unintended weight loss - poor growth in children - coughing blood or sputum - chills or night sweats the symptoms of tb may resemble other lung conditions or medical problems. consult a physician for a diagnosis. the tb bacterium is spread through the air when an infected person coughs, snee


larger scale processing such as tea and coffee production, processors offer training and an extension service to address problems with the crop as they arise throughout the growing season. although this may be beyond the resources of small scale processors, more limited types of assistance may include purchasing tools, fertilizer or other requirements in bulk with the savings being passed on to farmers. alternatively, part - payment for the crop can be made in advance so that farmers can buy inputs without the need for credit and the consequent indebtedness. the advantages to the processor are greater control over the quality of raw materials and the varieties that are planted, some control over the amounts supplied and an advance indication of likely raw material costs which assists in both financial control and production planning ( sections 2. 3. 4 and 2. 7. 1 ). the advantage to the farmer is the security of having a guaranteed market for the crop at a known price, together with any other incentives that may be offered by processors. however, this type of arrangement can only operate successfully when both processors and farmers honour their side of the agreement. in the authors experience, there have been a number of occasions when these forms of agreement have been tried, but have failed because one party breaks their part of the contract. typically, this can be farmers who sell part of their crop to traders at each end of the season, when the price is higher than that offered by the processor. the expected volume of crop is not then available to the processor and planned production capacity cannot be achieved, seriously damaging both sales and cashflow. alternatively, the processor delays payment to farmers, resulting in the need for them to take another loan and greater indebtedness. the processor may also fail to buy the agreed amount of crop and farmers are left to find alternative markets without the option of supplying traders who may refuse to buy it or may offer an insignificant price. a slightly different approach is that in which a processor takes a greater degree of control over production of the crop and specifies the types of fruit or vegetable to be grown, supplies seeds and other inputs, even including labour. in effect farmers are paid by the processor for the use of their land. although this involves greater organisational complexity and higher operating costs for the processor, the benefits of an assured supply of raw materials having the correct qualities for processing may outweigh the disadvantages, particularly in situations where the demand for a crop outstrips the supply. a further development of the approach is for the processor to rent or buy land and set up a separate operation to


the department of energy ( doe ) is committed to expanding the conversation on energy issues and upholding open government principles of transparency, participation and collaboration. one of the key ways we seek to accomplish this is through the use of social media. " social media " is a broad term for the wide spectrum of interactive and user - driven content technologies ( i. e., social networks, blogs, wikis, podcasts, online videos, etc ). like many government agencies, the department is exploring how best to use social media to accomplish our mission, engage the public in discussion, include people in the governing process and collaborate internally and externally. the office of digital strategy and communications ( formerly the new media office ) in the office of public affairs is leading the department ' s social media efforts. the purpose of this document is to provide guidance on how to take advantage of these social media platforms by defining the broad department of energy vision and strategy for social media use, detailing the means by which to contribute to the department ' s social media presence, outlining the various rules of the road for utilizing social media in the government space and last but not least, sharing best practices for various social media tools. it ' s worth noting that while the primary focus of this guidance is on external facing social media, many of the principles and requirements outlined below can be used as a roadmap for inward facing social media activities. vision and strategy " the department of energy has an urgent role to play in creating a new, clean energy economy that will spark job creation and reduce our dependence on oil, while cutting our greenhouse gas emissions. the department will also meet its critical responsibilities of reducing nuclear dangers and environmental risks. the foundation of all our work is a commitment to lead the world in science, technology and engineering. " - secretary steven chu the department of energy ' s mission is to become the " department of innovators " and discover the solutions to power and secure america ' s future now. we ' re building the new clean energy economy, reducing nuclear dangers and environmental risk and expanding the frontiers of knowledge with innovative scientific research. the objective of the digital office in public affairs is not only to communicate our mission online but also to develop and foster relationships with the public, outside stakeholders and each other around that mission. with that focus, the primary goals of the digital office are to amplify the department ' s message, promote transparency and accessibility and provide services and engagement opportunities. social media is integral to achieving these goals, providing the platform for real - time conversation, collaboration


focus, the primary goals of the digital office are to amplify the department ' s message, promote transparency and accessibility and provide services and engagement opportunities. social media is integral to achieving these goals, providing the platform for real - time conversation, collaboration and idea sharing. you know how the saying goes - our whole is much greater than the sum of our parts. the entire department benefits from a strong enterprise brand. and in many ways, that enterprise brand and culture of brand cultivation already exists throughout the department, powered by the office of public affairs. we ' re just extending it online and into the social media sphere. the digital office in the office of public affairs is responsible for managing department ' s enterprise brand online, including social media. leading by example, this office will push the department into new social media spaces and drive innovation and online communication programming in this arena. offices and labs across the department should help build the enterprise brand by contributing content and ideas to the digital office. a strong, well developed, supported and executed enterprise social media brand is the primary tier of the department ' s social media strategy. the digital office also serves as a support center for driving the second core component of the department ' s social media strategy : empowering social media innovation across the department. program offices, field offices and labs are encouraged to take full advantage of the opportunities social media offers. the digital office provides clear guidance on how to do so - - assisting with compliance of federal rules regulating social media in government, sharing social media best practices and helping offices develop and execute high quality social media strategies. contributing to the department of energy enterprise social media accounts the foundation of the department of energy enterprise social media brand is our mission - and the work being done everyday across the department to achieve that mission drives the content for our social media accounts. offices and labs are enthusiastically encouraged to contribute to our enterprise social media accounts and share what they ' re doing to achieve our mission. these contributions are integral to the success of our enterprise brand. one of the primary reasons department of energy enterprise social media accounts were established was to break down some of the resource and regulatory barriers for communicating in this sphere. in that spirit, it ' s also simple to contribute to our core enterprise accounts : youtube, flickr, twitter and facebook. just submit your suggestion to the digital office in the office of public affairs via the department of energy social media hub ( http : / / energy. gov / socialmedia ) and a member of the digital office will follow - up as needed within a reasonable timeframe.