by itself, the wnv - cp protein can cause inflammation. weiner and his colleagues found that wnv - cp drives apoptosis in cell cultures through what is called the mitochondrial pathway. the protein begins the process of cell suicide by somehow disrupting the membrane potential of the cell ' s mitochondria, which then leads to the activation of proteins such as caspase - 9 and caspase - 3 that start a cascade of reactions to subsequently cause the cell to digest itself. since the protein enters the nucleus of the cell, it is possible that wnv - cp changes the host cell ' s transcriptional machinery, resulting in an over production of certain proteins related to an apoptotic program, which consequently feed back to the mitochondria. alternatively, as wnv - cp moves from the cytoplasm to the nucleus, it may inactivate an important part of the cell ' s natural control system that keeps apoptosis in check overpowering the guard as it were thus inducing the cell suicide. " overall, our data suggest that wnv - cp may interact with host cell proteins to induce apoptosis in the host cell, " said weiner, " identifying these proteins will likely give more insight into the biology of west nile. " the proteins pathogenic properties extend outside of the tissue culture. wnv - cp also directly caused apoptosis and inflammation in mouse muscle cells. more importantly, the wnv - cp protein caused inflammation and apoptosis in mouse brain in a manner similar to what is observed in natural infections.


for national geographic news if a worker ant dares to reproduce in the presence of the queen, her sisters will smell her attempt and attack, according to a new study. typically, only queens produce offspring in an ant colony, and males die after mating. the sons and the daughter queens fly away, with hopes of reproducing elsewhere, while the worker daughters stay on to build the colony and care for the next generation. these worker ants are biologically capable of a type of parthenogenesis, the process that allows a female to produce offspring without a mate. when they try, however, they produce chemicals called pheromones that their sisters detect with antennas. " it ' s basically smell, but not the smell we know, " said study co - author jurgen liebig of arizona state university. if the colony lacks a queen, workers are permitted to have their own babies, liebig explained. but when a queen is present, only she is allowed to produce the pheromone that signals fertility status. if a worker tries to " cheat, " her sisters will physically restrain the disobedient ant from successfully reproducing. ( related : " ants practice nepotism, study finds " [ february 26, 2003 ]. ) the research was published online january 8 in the journal current biology. scent of a woman ant previous studies showed a correlation between ant ' s reproductive policing behavior and these pheromones, liebig said, so there was strong reason to believe the chemicals were tipping them off. " the problem was that nobody could ever show it, " he said. liebig ' s team studied the ant species aphaenogaster cockerelli because it uses a simple version of the compound that the scientists could easily obtain. sources and related web sites


you ’ ve heard that you should lower your cholesterol, but do you know why? sometimes we tend to ignore advice when we don ’ t understand the reasons. that ’ s why it ’ s important to learn what cholesterol is, what it does in your body and why you need to make sure too much isn ’ t flowing in your blood. cholesterol is a waxy, fat - like substance that your body needs to function normally. it ’ s used in the cell membranes that surround cells throughout your body. you also use cholesterol to make important chemicals, including hormones, vitamin d and the acids that help you digest fat. “ cholesterol has a variety of uses in the body that are very important, ” says dr. james cleeman, coordinator of nih ’ s national cholesterol education program, “ but the body makes all it needs and we don ’ t need to get any more from our food. ” in fact, when the level of cholesterol in the blood gets too high, it can start to cause trouble. the landmark framingham heart study, funded by nih, first showed that the higher the cholesterol level in your blood, the greater your risk for heart disease — the number 1 killer of americans, both women and men. what ’ s the connection? well, there are 2 forms of cholesterol in your blood : ldl and hdl. when there ’ s too much cholesterol in your bloodstream, the cholesterol from ldl can build up in the walls of your arteries. along with fats like triglycerides and other things in the bloodstream, it forms a growing “ plaque ” that bulges out of the artery wall and can begin to block blood flow — a process called atherosclerosis. problems get even worse if a plaque bursts and a blood clot forms on top, which can block an artery. “ where ldl cholesterol does its most harm, ” cleeman says, “ is in the walls of the arteries going to the heart — the coronary arteries. ” that ’ s why a high ldl cholesterol level increases your risk for heart disease. like any muscle, the heart ’ s own muscle needs a constant supply of oxygen and nutrients, delivered by the blood in the coronary arteries. when these arteries become narrowed or clogged by plaque, the result is coronary heart disease. if the blood supply to a portion of the heart is completely cut


constant supply of oxygen and nutrients, delivered by the blood in the coronary arteries. when these arteries become narrowed or clogged by plaque, the result is coronary heart disease. if the blood supply to a portion of the heart is completely cut off, the result is a heart attack. hdl cholesterol seems to have the opposite effect of ldl ; higher hdl levels are associated with a lower risk for heart disease. some factors affecting your cholesterol level are out of your control. as you get older, for example, your cholesterol level naturally rises. before menopause, women have lower total cholesterol levels than men of the same age, but after menopause women ’ s ldl levels tend to rise. high blood cholesterol can also run in families. your genes affect how fast you make cholesterol and remove it from the blood. however, there are things you can control. “ the clinical trial data are absolutely conclusive that lowering ldl cholesterol reduces your risk for heart disease, ” cleeman says. “ this is true both for those with high cholesterol levels and for those with average cholesterol levels. ” how do you know whether your cholesterol levels are where they should be? in general, the higher your risk for heart disease, the lower your ldl level should be. cleeman says, “ your goal is individualized to your risk for a heart attack. the number depends on your own risk factors. ” nih has a heart disease risk calculator online at http : / / hp2010. nhlbihin. net / atpiii / calculator. asp, but you should also talk to your doctor about your risk factors and what your cholesterol levels should be. “ a person who has a cholesterol level higher than their goal ldl should follow the tlc program, ” cleeman recommends. tlc stands for therapeutic lifestyle changes. it involves 3 things : changing what you eat, doing more physical activity and controlling your weight. first, diet. saturated fat raises your ldl cholesterol level more than anything else in your diet. it ’ s found mostly in meats and full - fat dairy products like whole milk, cheese and butter. another type of fat called trans fat raises cholesterol similarly, but makes up far less of the american diet. cholesterol in foods can also raise blood cholesterol levels, but its effect is not as strong as these


cheese and butter. another type of fat called trans fat raises cholesterol similarly, but makes up far less of the american diet. cholesterol in foods can also raise blood cholesterol levels, but its effect is not as strong as these fats ’. saturated fat, trans fat and cholesterol are all listed on food labels so that you can choose foods with lower amounts to help lower your ldl cholesterol level. foods with soluble fiber — such as whole grain cereals, fruits and beans — help lower your cholesterol, too. and some products, such as specially labeled margarines, orange juices and yogurts, contain the ldl - lowering compounds “ stanols ” and “ sterols. ” excess weight can increase your ldl cholesterol level. “ fat tissue is not inert, ” cleeman says. “ it ’ s chemically active and produces all kinds of changes. ” one is raising ldl blood cholesterol levels. losing weight can help lower your ldl and total cholesterol levels, as well as raise your hdl and lower your triglycerides. regular physical activity can help you control your weight, lower your ldl and raise your hdl levels. you should try to be physically active for at least 30 minutes a day. if these lifestyle changes don ’ t lower your ldl cholesterol enough, medication can help. “ medication should be added to lifestyle changes, ” cleeman advises, “ not substituted for them. ” lifestyle changes can bring benefits medications can ’ t. while both can lower ldl, lifestyle improvements can lower blood pressure and other risk factors as well. nih ’ s national heart, lung and blood institute recommends that everyone older than 20 have their blood cholesterol measured at least once every 5 years. learn your numbers. then talk to your doctor about whether you need to take steps to alter your diet, lose weight or get more physically active to lower your blood cholesterol and stay healthy.


new tool developed to trace brown fat, fight obesity london, july 19 ( ians ) scientists have enlisted a pioneering new tool which uses thermal imaging to spot brown fat - the body ' s good fat - to fight obesity. brown fat plays a vital role in quickly burning away the calories and produces 300 times more heat than any other tissue in the body. it means that the more of it we have, the less likely we are to store excess energy or food as harmful fat. michael symonds, professor of developmental physiology at the university of nottingham, who led the study, said : " this completely non - invasive technique could play a crucial role in our fight against obesity, " the journal of paediatrics reports. " potentially, we could add a thermogenic index to food labels to show whether that product would increase or decrease heat production within brown fat. in other words, whether it would speed up or slow down the amount of calories we burn, " added symonds, according to a nottingham statement. helen budge, clinical associate professor in neonatology at nottingham, who worked with symonds, said : " babies have a larger amount of brown fat which they use up to keep warm soon after birth making our study ' s finding that this healthy fat can also generate heat in childhood and adolescence very exciting. " read more : university grants commission ( ugc ) | guru nanak dev university | kumaon university nainital | gorakhpur university | agra university | ayurvedic university | bundelkhand university so | mds university ajmer dtso | madras university po | world university centre | pondicherry university | annamalai university | kannur university campus | calicut university | kochi university | jadavpur university | kolkata university | budge budge natun bazar s. o. | budge budge s. o. ( hsg - ii ) | vidyasagar university so 4th c v raman int ' l fellowship launched for research may 21, 2013 at 10 : 07 pm we will bring a new law to regulate fixing : jitendra singh may 21, 2013 at 10 : 00 pm court allows five day police custody for the ipl fixers may 21, 2013 at 9 : 58 pm


in 1860 – 61 robert o ’ hara burke and william john wills led an expedition to cross australia from melbourne in the south to the gulf of carpentaria in the north. after arriving at their base camp at cooper ’ s creek, burke selected wills, john king and charles gray to accompany him to the gulf and left four men at the base camp. they reached the gulf but on their return journey gray died of exhaustion, and when the others arrived back at the base camp it was deserted, the reserve party having departed only nine hours before they arrived. burke decided to try to reach a police station at mount hopeless, but they eventually became too weak to continue, and he and wills died from exhaustion and starvation. only king survived, kept alive by indigenous australians until a search party found him. lambert depicted the exhausted body of burke slumped against a tree, with king standing looking into the far distance and wills crouching near an exhausted camel. he placed the event within a harsh and desolate australian outback scene, overlooked by ominous black crows. he made this watercolour as an illustration for w. h. lang ’ s account of the expedition. it was published with the caption : ‘ on the way to mount hopeless ’ in a volume of boys ’ stories, romance of empire : australia, in 1908. this was the first attempt to present australia ’ s history in the form of an illustrated book for boys and met with considerable success. many artists depicted this story, including ludwig becker and hermann beckler, who participated in the expedition. john longstaff painted arrival of burke, wills and king at the deserted camp at cooper ’ s creek, sunday evening, 21st april 1861 ( national gallery of victoria, melbourne ) in the same year that lambert made this watercolour.


france 1868 – 1941 breton women with umbrellas [ les bretonnes aux ombrelles ] 1892 oil on canvas canvas 81. 0 ( h ) x 105. 0 ( w ) cm musee d ' orsay, paris, purchase 1955 © rmn ( musee d ' orsay ) / herve lewandowski in 1886, at the age of eighteen, bernard set off on a walking trip through normandy and brittany. there he met paul gauguin in pont - aven, at the recommendation of emile schuffenecker. two years later, in a letter from arles dated 20 june 1888, van gogh proposed that bernard meet again with the older artist : ‘ gauguin too is bored at pont - aven and complains like you of his isolation. why not go and see him? ’ 1 bernard did so. he was just twenty years old and brimming with new theories and ideas about how to make art. it was at pont - aven that bernard painted a canvas, breton women in a meadow, which, according to the artist, preceded gauguin ’ s radical painting vision of the sermon ( jacob wrestling with the angel ). 2 the two artists worked together, along with louis anquetin and paul serusier, developing a style which came to be known as ‘ cloisonisme ’, or cloisonnism — a term coined by the critic edouard dujardin when reviewing the art of anquetin in his essay for la revue independante, 1 march 1888. cloisonnism abandoned three - dimensional modelling for flatter two dimensional forms with heavy dark outlines. it was a style that shunned naturalism and adopted a more symbolic focus, assuming a brighter palette in order to express human emotion. it was, in part, inspired by gothic art ( particularly stained - glass and enamel work ) and japanese ukiyo - e woodblock prints, in vogue amongst many artists of the pont - aven school. the close artistic collaboration between bernard and gauguin ended in 1891, when gauguin was described as the founder of the evolving pont - aven movement. 3 bernard considered this role rightfully his. bernard ’ s sister madeleine accused gauguin of reneging on his promise to exhibit together with bernard before he left for tahiti : ‘ you are a traitor, you have broken your pledge and done the greatest harm to my brother, who is the real initiator of the art that you claim as being your own ’. 4 breton women with


before he left for tahiti : ‘ you are a traitor, you have broken your pledge and done the greatest harm to my brother, who is the real initiator of the art that you claim as being your own ’. 4 breton women with umbrellas was made the year after this rift. it is one of a series of paintings created in bold outlines and colours which extend bernard ’ s monumental style of the late 1880s and signal his claim to be the originator of what he called ‘ pictorial symbolism ’. the canvas reveals bernard ’ s continuing fascination with gothic art and adds to the exotic perception of breton women as timeless and immutable beings, living simple pious lives. the artist has depicted these figures in simplified forms and bold colours, and placed them within an almost two - dimensional village backdrop. bernard came to admire these women, and frequently represented them as figures of devotion, as if they had stepped out of the art of the medieval ages. text © national gallery of australia, canberra 2009 from masterpieces from paris : van gogh, cezanne, gauguin and beyond post - impressionism from the musee d ' orsay exhibition book, national gallery of australia, canberra 2009 - quoted in douglas lord ( ed. and trans. ), letters to emile bernard, new york : museum of modern art 1938, p. 40. - national gallery of scotland, edinburgh. - in an article by albert aurier, ‘ le symbolisme en peinture — paul gauguin ’, mercure de france, march 1891, pp. 159 – 64. - henri dorra, emile bernard and paul gauguin, gazette des beaux - arts, 6 series, vol. 45, april 1955, p. 244.


during the 1980s the number of babies born annually was around 12. the total twice fell sharply in the 1990s until just a single calf appeared in 2000. since then, the average has risen to more than 20 calves a year. yet this remains 30 percent below the whales ' potential rate of reproduction. why? if scientists are to guide the species ' salvation, they need more data and more answers. fast. one august morning in 2006, when the sea was a sheet of dimpled satin shot through with silver threads, i joined scott kraus, the new england aquarium ' s vice president of research, and rosalind rolland, a veterinarian and senior scientist with the aquarium, on an unlikely quest in the bay of fundy. when leviathans rose in the distance through the sea ' s shimmering skin, kraus steered the boat downwind of where they had briefly surfaced, handed me a data sheet to log our movements, and zigzagged into the faint breeze. rolland moved onto the bow. beside her was fargo, the world ' s premier whale - poop - sniffing dog. fargo began to pace from starboard to port, nostrils flaring. rolland focused on the rottweiler ' s tail. if it began to move, it would mean he had picked up a scent — and he could do that a nautical mile away. twitch … twitch … wag, wag. " starboard, " rolland called to kraus. " a little more. nope, too far. turn to port. ok, he ' s back on it. " a quarter of an hour ran by like the bay ' s currents. all i saw were clumps of seaweed. suddenly, the dog sat and turned to fix rolland with a look. we stopped, and out of the vast ocean horizon came a single chunk of digested whale chow, bobbing along mostly submerged, ready to sink from view or dissolve altogether within minutes. kraus grabbed the dip net and scooped up the fragrant blob. you ' d have thought he was landing a fabulous fish. " at first, people are incredulous. then come the inevitable jokes. but this, " said the man who has led north atlantic right whale research for three decades, " is actually some of the best science we ' ve done. " with today ' s technology, dna from sloughed - off intestinal cells in a dung sample can identify the individual that produced it. residues of hormones tell rolland about the whale ' s


please use this identifier to cite or link to this item : http : / / hdl. handle. net / 1959. 13 / 916979 - the ' humped ' soil production function : eroding arnhem land, australia heimsath, arjun m. ; hancock, greg r. - the university of newcastle. faculty of science & information technology, school of environmental and life sciences - we report erosion rates and processes, determined from in situ - produced beryllium - 10 ( ¹⁰be ) and aluminum - 26 ( ²⁶al ), across a soil - mantled landscape of arnhem land, northern australia. soil production rates peak under a soil thickness of about 35 cm and we observe no soil thicknesses between exposed bedrock and this thickness. these results thus quantify a well - defined ‘ humped ’ soil - production function, in contrast to functions reported for other landscapes. we compare this function to a previously reported exponential decline of soil production rates with increasing soil thickness across the passive margin exposed in the bega valley, south - eastern australia, and found remarkable similarities in rates. the critical difference in this work was that the arnhem land landscapes were either bedrock or mantled with soils greater than about 35 cm deep, with peak soil production rates of about 20 m / ma under 35 – 40 cm of soil, thus supporting previous theory and modeling results for a humped soil production function. we also show how coupling point - specific with catchment - averaged erosion rate measurements lead to a better understanding of landscape denudation. specifically, we report a nested sampling scheme where we quantify average erosion rates from the first - order, upland catchments to the main, sixth - order channel of tin camp creek. the low ( ~ 5 m / ma ) rates from the main channel sediments reflect contributions from the slowly eroding stony highlands, while the channels draining our study area reflect local soil production rates ( ~ 10 m / ma off the rocky ridge ; ~ 20 m / ma from the soil mantled regions ). quantifying such rates and processes help determine spatial variations of soil thickness as well as helping to predict the sustainability of the earth ' s soil resource under different erosional regimes. - earth surface processes and landforms vol. 34, issue 12, p. 1674 - 1684 - publisher link - john wiley & sons - resource type - journal article


find a physician more on flu ( influenza ) more on flu ( influenza ) research and clinical trials more on flu ( influenza ) what is influenza ( flu )? influenza ( or flu ) is a highly contagious viral respiratory tract infection. an estimated 5 to 20 percent of the population in the us contract influenza each year. influenza is characterized by the abrupt onset of fever, muscle aches, sore throat, and a nonproductive cough. influenza can make people of any age ill. although most people are ill with influenza for only a few days, some have a much more serious illness and may need to be hospitalized. influenza can also lead to pneumonia and death. influenza viruses are divided into three types, designated as a, b, and c. - influenza types a and b are responsible for epidemics of respiratory illness that occur almost every winter and are often associated with increased rates for hospitalization and death. efforts to control the impact of influenza are focused on types a and b. - influenza type c usually causes either a very mild respiratory illness or no symptoms at all. it does not cause epidemics and does not have the severe public health impact that influenza types a and b do. influenza viruses continually mutate or change, which enables the virus to evade the immune system of its host. this makes people susceptible to influenza infection throughout their lives. the process works as follows : - a person infected with influenza virus develops antibody against that virus. - the virus mutates or changes. - the " older " antibody no longer recognizes the " newer " virus. - reinfection occurs. the older antibody can, however, provide partial protection against reinfection. currently, three different influenza viruses circulate worldwide : two type a viruses and one type b virus. immunizations given each year to protect against the flu contain the influenza virus strain from each type that is expected to cause the flu within that year. facts about the flu : although each flu season is different, approximately 5 to 20 percent of the population will get the flu each year. approximately 36, 000 of those who get the flu will die from it or from complications. what causes influenza? the influenza virus is generally passed from person to person by airborne transmission ( i. e., sneezing or coughing ). but, the virus can also live for a short time on objects - such as doorknobs, pens, pencils, keyboards, telephone receivers, and eating or drinking utensils. therefore, it may also be spread by touching something that has


, the virus can also live for a short time on objects - such as doorknobs, pens, pencils, keyboards, telephone receivers, and eating or drinking utensils. therefore, it may also be spread by touching something that has been handled by someone infected with the virus and then touching your own mouth, nose, or eyes. what are the symptoms of the flu? the following are the most common symptoms of the flu. however, each individual may experience symptoms differently. influenza is called a respiratory disease, but the whole body seems to suffer when a person is infected. people usually become acutely ill with several, or all, of the following symptoms : - high fever - clear nose - sneezing at times - cough, often becoming severe - severe aches and pains - fatigue for several weeks - sometimes a sore throat - extreme exhaustion fever and body aches usually last for three to five days, but cough and fatigue may last for two weeks or more. although nausea, vomiting, and diarrhea may accompany the flu, these gastrointestinal symptoms are rarely prominent. " stomach flu " is an incorrect term sometimes used to describe gastrointestinal illnesses caused by other microorganisms. the symptoms of the flu may resemble other medical conditions. always consult your physician for a diagnosis. treatment for influenza : specific treatment for influenza will be determined by your physician based on : - your age, overall health, and medical history - extent and type of influenza, and severity of symptoms - your tolerance for specific medications, procedures, or therapies - expectations for the course of the disease - your opinion or preference the goal of treatment for influenza is to help prevent or decrease the severity of symptoms. treatment may include : - medications to relieve aches and fever ( aspirin should not be given to children with fever without first consulting a physician ). the drug of choice for children is acetaminophen ( tylenol ). - medications for congestion and nasal discharge - bed rest and increased intake of fluids antiviral medications - when started within the first two days of treatment, they can reduce the duration of the disease but cannot cure it. four medications have been approved and include amantadine, rimantadine, zanamivir, and oseltamivir. some side effects may result from taking these medications, such as nervousness, lightheadedness, or nausea. individuals with asthma or chronic obstructive pulmonary disease are cautioned about using zanamivir. viral resistance to these drugs may


. some side effects may result from taking these medications, such as nervousness, lightheadedness, or nausea. individuals with asthma or chronic obstructive pulmonary disease are cautioned about using zanamivir. viral resistance to these drugs may vary. some drugs may be ineffective if current viral strains have developed resistance. all of these medications must be prescribed by a physician. consult your physician for more information. how to prevent the flu : a new influenza vaccine is introduced each september. it is usually recommended for specific groups of people ( see below ), as well as for persons who want to avoid having the flu. in addition, three antiviral medications ( amantadine, rimantadine, and oseltamivir ) are approved for use in preventing the flu. all of these medications are available by prescription, and a physician should be consulted before any medication is used for preventing the flu. a nasal - spray flu vaccine, called flumist, is currently approved to prevent flu due to influenza a and b viruses in healthy children and adolescents ( ages two to 17 ), and healthy adults ( ages 18 to 49 ). as with other live virus vaccines, flumist should not be given for any reason to pregnant women and people with immune suppression, including those with immune deficiency diseases, such as aids or cancer, and people who are being treated with medications that cause immunosuppression. flumist also should not be given to the following groups of people : - children less than two years of age - any person with asthma - children less than five years of age with recurrent wheezing following these precautions may also be helpful : - when possible, avoid or limit contact with infected persons. - frequent handwashing may reduce, but not eliminate, the risk of infection. - a person who is coughing or sneezing should cover his / her nose and mouth with a handkerchief to limit spread of the virus. how effective is the flu vaccine? vaccine effectiveness varies from year to year, depending upon the degree of similarity between the influenza virus strains included in the vaccine and the strain or strains that circulate during the influenza season. vaccine strains must be chosen 9 to 10 months before the influenza season, and sometimes mutations occur in the circulating strains of viruses between the time vaccine strains are chosen and the next influenza season. these mutations sometimes reduce the ability of the vaccine - induced antibody to inhibit the newly mutated virus, thereby reducing vaccine effectiveness. vaccine effectiveness also varies from one person to another, depending on factors such as age and


are chosen and the next influenza season. these mutations sometimes reduce the ability of the vaccine - induced antibody to inhibit the newly mutated virus, thereby reducing vaccine effectiveness. vaccine effectiveness also varies from one person to another, depending on factors such as age and overall health. what are the side effects of the flu vaccine? the most serious side effect that can occur after influenza vaccination is an allergic reaction in people who have a severe allergy to eggs. for this reason, people who have an allergy to eggs should not receive the influenza vaccine. the national center for infectious diseases ( a division of the centers for disease control and prevention, cdc ) says that influenza vaccine causes no side effects in most people who are not allergic to eggs. less than one - third of people who receive the vaccine experience some soreness at the vaccination site, and about 5 to 10 percent experience mild side effects, such as headache or low - grade fever for about a day after receiving the vaccination. because these mild side effects mimic some influenza symptoms, some people believe the influenza vaccine causes them to get influenza. however, according to the cdc, " influenza vaccine produced in the united states has never been capable of causing influenza because the only type of influenza vaccine that has been licensed in the united states to the present time is made from killed influenza viruses, which cannot cause infection. " who should immunize against the flu? the flu causes complications that may develop into a more serious disease or become dangerous to some groups, such as elderly people and those with chronic medical conditions. for these reasons, the cdc recommends that the following groups immunize themselves each year. always consult your physician for more information regarding who should receive the flu vaccine : - persons 50 years old or older ( vaccine effectiveness may be lower for elderly persons, but it can significantly reduce their chances of serious illness or death from influenza. ) - children and adolescents six months to 19 years of age - residents of nursing homes and any other chronic care facilities that house persons of any age who have chronic medical conditions - adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including children with asthma - adults and children who have the following medical conditions : - chronic metabolic diseases ( i. e., diabetes ) - renal dysfunction - children and teenagers ( aged 6 months to 19 years ) receiving long - term aspirin therapy - women who will be pregnant during flu season in addition, the following groups should be vaccinated : - healthcare providers - employees of nursing homes and chronic care facilities


teenagers ( aged 6 months to 19 years ) receiving long - term aspirin therapy - women who will be pregnant during flu season in addition, the following groups should be vaccinated : - healthcare providers - employees of nursing homes and chronic care facilities who have contact with patients or residents - providers of home care to persons at high risk - household members ( including children ) of persons in high - risk groups - persons of any age who wish to decrease their chances of influenza infection, excluding persons who are allergic to eggs when should i get a flu shot? the centers for disease control and prevention ( cdc ) recommends getting the flu shot every year, between september and mid - november, before the flu season hits ( usually december to april ). the flu shot takes one to two weeks to become effective. although there are many new medications designed to treat flu symptoms and even shorten the duration of the illness, the flu vaccine still offers the best protection against the flu. if i get the flu shot, can i still get the flu? every year, the flu shot " cocktail " changes to combat the current strains of influenza affecting the population. the world health organization ( who ) monitors flu outbreaks worldwide and recommends appropriate vaccine compositions to be used for the next year. however, sometimes, a strain may appear that was not included in the flu vaccine. people who have had the flu shot tend to have milder symptoms if they contract the flu. traveling and exposure to the flu : because the flu is a highly contagious infection usually spread by droplets produced by an infected person who is coughing or sneezing, travelers are very susceptible to contracting the flu. the cdc recommends that travelers have the flu vaccine at least two weeks in advance of planned travel to allow time to develop protective immunity. there are other anti - viral drugs available to help prevent viral infections and complications. consult your physician for more information. click here to view the online resources of infectious diseases


- blockages in the lungs and airways - problems digesting and absorbing nutrients | copyright © nucleus medical media, inc. | - parents who are known carriers of the cf gene - siblings with cf - parents with cf ( mostly mother since men with cf are often sterile ) - difficulty passing the first stool ( meconium ) - meconium ileus ( intestinal obstruction ), sometimes requires surgery - salty sweat - coughing and wheezing - shortness of breath - difficulty with exercise - repeated pneumonia - severe, chronic sinusitis - abnormally shaped clubbed finger tips - barrel chest - nasal polyps - trouble gaining weight - poor growth - failure to thrive - bulky, bad - smelling, floating stools, due to poor digestion of fats - insulin - dependent diabetes - liver cirrhosis - salty sweat - mildly decreased fertility in females - prolapsed rectum - prevention of sperm production in males - sweat chloride testing ( still the standard for making a diagnosis of cf ) - transepithelial difference measurement - improving the amount of nutrition your body receives - preventing and treating lung infections - keeping the airways and lungs as clear as possible - high - calorie diet planned by a registered dietitian - nutritional supplements, including fat - soluble vitamins - pancreatic enzyme tablets with meals to improve digestion and absorption of nutrients - drinking lots of fluids, especially in hot weather or when ill managing lung infections - inhaled and / or systemic antibiotics - antibiotics to treat recurrent lung infections lung and airway support - bronchodilators — to relax muscles and open the airway - steroid inhalers — to decrease swelling and irritation - mucolytic agents — to reduce mucus and help it move out of the lung - hypertonic saline is a special type of salt water. a nebulizer machine creates a mist of this saline, which is inhaled by the user. the mist may help thin out the mucus in the lungs. - chest percussion and postural drainage or high - frequency chest wall oscillation are rhythmic clapping over the chest. they may help clear mucus from airways. american lung association http : / / www. lungusa. org / cystic fibrosis foundation http : / / www. cff. org / about kids health http : / / www. aboutkidshealth. ca / sick kids http : / / www. sickkids. ca / about cystic fibrosis : what you need to know. cystic fibrosis foundation website


kids health http : / / www. aboutkidshealth. ca / sick kids http : / / www. sickkids. ca / about cystic fibrosis : what you need to know. cystic fibrosis foundation website. available at : http : / / www. cff. org / aboutcf /. accessed december 11, 2012. cystic fibrosis. american academy of pediatrics healthy children website. available at : http : / / www. healthychildren. org / english / health - issues / conditions / chronic / pages / cystic - fibrosis. aspx. updated january 9, 2012. accessed december 11, 2012. cystic fibrosis. ebsco dynamed website. available at : http : / / www. ebscohost. com / dynamed. updated november 7, 2012. accessed december 11, 2012. cystic fibrosis testing. american medical association website. available at : http : / / www. ama - assn. org / ama / pub / physician - resources / medical - science / genetics - molecular - medicine / related - policy - topics / genetic - testing / cystic - fibrosis - testing. shtml. accessed december 11, 2012. conn hf, rakel re. conn ’ s current therapy. 54th ed. philadelphia, pa : wb saunders company ; 2002 : 720 - 721. federico, mj, kerby, gs, deterding, rr, et al. respiratory tract & mediastinum. in hay w. w., et al, eds. current diagnosis & treatment : pediatrics. 20th ed. new york, ny : mcgraw - hill companies, inc ; 2011. kleigman rm, jensen hb, behrman re, stanton bf. nelson textbook of pediatrics. 18th ed. philadelphia, pa : saunders elsevier ; 2007. 4 / 16 / 2009 dynamed ' s systematic literature surveillance http : / / www. ebscohost. com / dynamed / what. php : lai hj, shoff sm, farrell pm ; wisconsin cystic fibrosis neonatal screening group. recovery of birth weight z score within 2 years of diagnosis is positively associated with pulmonary status at 6 years of age in children with cystic fibrosis. pediatrics. 2009 ; 123 : 714 - 722. - reviewer : michael woods, md - review date : 11 / 2012 -


every year, tens of millions of sharks are killed for their fins alone. shark fins are used to make shark fin soup, a popular and expensive dish that is a symbol of wealth and status primarily in asian cultures. the demand for fins can lead to cruel and wasteful practices, such as cutting off a shark ’ s fins at sea and then throwing the rest of the shark, sometimes still alive, back into the water. and shark fin soup can be dangerous to humans. since sharks are at the top of the food chain, they accumulate toxins like mercury, which is a dangerous neurotoxin. so are there any alternatives to shark fin soup? shark fins themselves have no taste and are used only for texture. in traditional shark fin soup recipes, chicken or fish stock is added to give the soup flavor which means that there are a lot of ways to enjoy shark fin soup without using shark fins – like this recipe from the monterey bay aquarium : today, the maryland state senate education, health, and environmental affairs committee is holding a hearing on numerous bills including a bill that would ban the possession, sale, trade and distribution of shark and ray fins. this bill will help protect global shark populations by reducing the demand for their fins. each year, tens of million sharks are killed so that their fins can be used in shark fin soup. in the united states, the cruel and wasteful practice of shark finning is illegal. however, many fins are imported from all around the world, contributing to the demand for shark fins and the overfishing of sharks. hawaii, oregon, washington, and california have already passed similar laws, and bills have also been introduced in new york, illinois, florida, and virginia. oceana supports maryland ’ s initiative and asks that state residents do so as well. please show your support by telling your legislator to vote for sb 465! in singapore, we ’ re seeing more proof that dedicated activists can make a difference in the world. singapore is one of the shark fin capitals of the world, but thanks to an outcry from local customers, its largest supermarket chain, fairprice, will be pulling fins from its shelves. shark fins are often cut from live sharks, which are then thrown overboard to die. the huge demand for fins, considered a delicacy, puts some shark species at risk of extinction. and while shark fin is a culturally important food in singapore, the tide is turning. a campaign by divers against shark fins caused one of fairprice ’ s suppliers to launch an online


delicacy, puts some shark species at risk of extinction. and while shark fin is a culturally important food in singapore, the tide is turning. a campaign by divers against shark fins caused one of fairprice ’ s suppliers to launch an online attack ad that said “ screw the divers! ” luckily for sharks, the ad backfired. not all singaporeans are shark fin fans. local groups like project fin have been fighting to create change from the inside out, and they are finally having an impact. in response to the ad, singaporeans sent hundreds of complaints to fairprice and suggested a boycott. in response, fairprice made the smart — and surprising — decision to stop selling shark fins. " it is encouraging to see fairprice respond promptly to the public reaction. they can progress further by selling only sustainable food, " said jennifer lee, founder of project fin. kudos to the singaporean shark protectors for such a powerful victory in the wake of cultural pressure. it ’ s not every day that you hear about the marshall islands. scattered across a swath of the pacific ocean, these islands are home to only about 68, 000 people. but as of this week, the waters around these islands may become home to a whole lot more sharks. that ’ s because the government has decided to make all of its waters — more than 750, 000 square miles, or about the size of mexico — a shark sanctuary. this move will almost double the area in which sharks are protected globally. within the marshall islands, it will now be illegal to commercially fish sharks, sell any shark products, and use wire leaders ( a type of fishing gear often responsible for shark deaths ). in addition, all sharks caught accidentally must be released, and fishing boats will be required to bring all their catch directly to port for inspection — an important step in combating seafood fraud. fines for having shark products will run the equivalent of $ 25, 000 to $ 200, 000. great news this shark week! we just got word that oregon governor john kitzhaber will sign a bill this afternoon banning the sale, trade, and possession of shark fins in the state. oceana was instrumental in the passage of this bill, which passed the state house and senate with bipartisan support. the bill ’ s passage moves the u. s. west coast closer to a full ban on the trade of shark fins, thereby helping to protect global populations of at - risk shark species that are being targeted in unsustainable and unregul


the bill ’ s passage moves the u. s. west coast closer to a full ban on the trade of shark fins, thereby helping to protect global populations of at - risk shark species that are being targeted in unsustainable and unregulated fisheries worldwide. while shark finning is illegal in the u. s., current federal laws banning the practice do not address the shark fin trade. as a result, fins are being imported to the u. s. from countries with few or even no shark protections in place. governor chris gregoire of washington state signed similar legislation into law on may 12, 2011 and a bill in the california legislature passed the assembly and is currently under consideration in committee in the senate. we commend governor kitzhaber for his extraordinary leadership to protect the ocean ’ s top predators, and congratulate our pacific colleagues for their work in achieving this victory! fantastic news! earlier this afternoon, the chilean national congress passed a nationwide ban on shark finning. this groundbreaking decision comes on the heels of a very similar ban passed by the united states congress last december, and puts both countries at the forefront of shark conservation. oceana drafted the chilean bill in january, and we are elated to see it pass into law – without a single dissenter. shark finning is an inhumane practice that often involves throwing the rest of the shark ’ s body back into the water once the desired fin is obtained. despite its cruelty, shark finning is incredibly rampant, due to culinary demand from asian countries such as china, where shark fin soup is popular. with the passage of this bill, chile joins a growing list of countries leading the way in shark conservation. because sharks do not respect national boundaries, this legislation will help protect shark populations and ocean health in chile and beyond. stellar news for sharks today : washington governor christine gregoire signed into law a ban on the trade of shark fins. “ by signing this legislation the governor took a very large west coast leadership role in initiating action to address a global problem, ” said whit sheard, senior advisor and pacific counsel for oceana. “ this bill will do two things, help us move closer to ending the wasteful and unnecessary depletion of our ocean ’ s top predators and serve as a model for oregon and california as they have similar pending legislation. ” while shark finning is illegal in the u. s., current federal laws banning shark finning do not address the issue of the shark fin trade. as a result, fins are being


for oregon and california as they have similar pending legislation. ” while shark finning is illegal in the u. s., current federal laws banning shark finning do not address the issue of the shark fin trade. as a result, fins are being imported to the u. s. from countries with limited to zero shark protections in place. similar legislation passed recently in hawaii and guam and is pending in oregon and california. each year, tens of millions of sharks are killed for their fins, mostly to make shark fin soup. in this wasteful and cruel practice, a shark ’ s fins are sliced off while at sea and the remainder of the animal is thrown back into the water to die. congrats to oceana ’ s pacific campaigners for helping win this great victory for sharks! chinese nba basketball star yao ming hopes so. as center for the houston rockets, ming is spreading the word to “ say no to shark fin soup ” with his new ads sponsored by oceana and wildaid. ming ’ s message is traveling through san francisco by bus, including those on chinatown routes to support legislation ( ab 376 ) to ban the possession, sale, trade, and distribution of shark fins in california. great news from the evergreen state : washington state ’ s legislature has passed a bill banning the illegal trade of shark fins, an extraordinary step toward shark conservation on the u. s. pacific coast. the legislation now goes to the governor ’ s desk to be signed into law. while shark finning is illegal in the u. s., current federal laws banning shark finning do not address the issue of the shark fin trade. as a result, fins are being imported to the u. s. from countries with limited to zero shark protections in place. similar legislation passed recently in hawaii and is pending in oregon and california. “ this legislation is an excellent example of a state taking action to address a global problem, ” said whit sheard, senior advisor and pacific counsel for oceana. “ this bill will help us move closer to ending the wasteful and unnecessary depletion of our ocean ’ s top predators. ” as shark week comes to a close, we thought we ’ d hit you with the good stuff : numbers. here are some of the most revealing statistics about sharks that we could find : 400 million : approximate number of years that sharks have been on planet earth. 50 : number of shark species that are listed as vulnerable, endangered or critically endangered on the iucn red list of threatened species 138, 894 : number of


front page titles ( by subject ) origin and causes of the sterility of first crosses and of hybrids. - the origin of species by means of natural selection or the preservation of favored races in the struggle for life, vol. 2 return to title page for the origin of species by means of natural selection or the preservation of favored races in the struggle for life, vol. 2 the online library of liberty a project of liberty fund, inc. search this title : also in the library : origin and causes of the sterility of first crosses and of hybrids. - charles darwin, the origin of species by means of natural selection or the preservation of favored races in the struggle for life, vol. 2 the origin of species by means of natural selection or the preservation of favored races in the struggle for life, with additions and corrections from the sixth and last english edition, in two volumes ( new york : d. appleton and co., 1896 ). volume 2. part of : the origin of species by means of natural selection or the preservation of favored races in the struggle for life, 2 vols. about liberty fund : the text is in the public domain. fair use statement : origin and causes of the sterility of first crosses and of hybrids. at one time it appeared to me probable, as it has to others, that the sterility of first crosses and of hybrids might have been slowly acquired through the natural selection of slightly lessened degrees of fertility, which, like any other variation, spontaneously appeared in certain individuals of one variety when crossed with those of another variety. for it would clearly be advantageous to two varieties or incipient species, if they could be kept from blending, on the same principle that, when man is selecting at the same time two varieties, it is necessary that he should keep them separate. in the first place, it may be remarked that species inhabiting distinct regions are often sterile when crossed ; now it could clearly have been of no advantage to such separated species to have been rendered mutually sterile, and consequently this could not have been effected through natural selection ; but it may perhaps be argued, that, if a species was rendered sterile with some one compatriot, sterility with other species would follow as a necessary contingency. in the second place, it is almost as much opposed to the theory of natural selection as to that of special creation, that in reciprocal crosses the male element of one form should have been rendered utterly impotent on a second form, whilst at the same


the second place, it is almost as much opposed to the theory of natural selection as to that of special creation, that in reciprocal crosses the male element of one form should have been rendered utterly impotent on a second form, whilst at the same time the male element of this second form is enabled freely to fertilise the first form ; for this peculiar state of the reproductive system could hardly have been advantageous to either species. in considering the probability of natural selection having come into action, in rendering species mutually sterile, the greatest difficulty will be found to lie in the existence of many graduated steps from slightly lessened fertility to absolute sterility. it may be admitted that it would profit an incipient species, if it were rendered in some slight degree sterile when crossed with its parent form or with some other variety ; for thus fewer bastardised and deteriorated offspring would be produced to commingle their blood with the new species in process of formation. but he who will take the trouble to reflect on the steps by which this first degree of sterility could be increased through natural selection to that high degree which is common with so many species, and which is universal with species which have been differentiated to a generic or family rank, will find the subject extraordinarily complex. after mature reflection it seems to me that this could not have been effected through natural selection. take the case of any two species which, when crossed, produced few and sterile offspring ; now, what is there which could favour the survival of those individuals which happened to be endowed in a slightly higher degree with mutual infertility, and which thus approached by one small step towards absolute sterility? yet an advance of this kind, if the theory of natural selection be brought to bear, must have incessantly occurred with many species, for a multitude are mutually quite barren. with sterile neuter insects we have reason to believe that modifications in their structure and fertility have been slowly accumulated by natural selection, from an advantage having been thus indirectly given to the community to which they belonged over other communities of the same species ; but an individual animal not belonging to a social community, if rendered slightly sterile when crossed with some other variety, would not thus itself gain any advantage or indirectly give any advantage to the other individuals of the same variety, thus leading to their preservation. but it would be superfluous to discuss this question in detail ; for with plants we have conclusive evidence that the sterility of crossed species must be due to some principle, quite independent of


the same variety, thus leading to their preservation. but it would be superfluous to discuss this question in detail ; for with plants we have conclusive evidence that the sterility of crossed species must be due to some principle, quite independent of natural selection. both gartner and kolreuter have proved that in genera including numerous species, a series can be formed from species which when crossed yield fewer and fewer seeds, to species which never produce a single seed, but yet are affected by the pollen of certain other species, for the germen swells. it is here manifestly impossible to select the more sterile individuals, which have already ceased to yield seeds ; so that this acme of sterility, when the germen alone is affected, cannot have been gained through selection ; and from the laws governing the various grades of sterility being so uniform throughout the animal and vegetable kingdoms, we may infer that the cause, whatever it may be, is the same or nearly the same in all cases. we will now look a little closer at the probable nature of the differences between species which induce sterility in first crosses and in hybrids. in the case of first crosses, the greater or less difficulty in effecting an union and in obtaining offspring apparently depends on several distinct causes. there must sometimes be a physical impossibility in the male element reaching the ovule, as would be the case with a plant having a pistil too long for the pollen - tubes to reach the ovarium. it has also been observed that when the pollen of one species is placed on the stigma of a distantly allied species, though the pollen - tubes protrude, they do not penetrate the stigmatic surface. again, the male element may reach the female element but be incapable of causing an embryo to be developed, as seems to have been the case with some of thuret ’ s experiments on fuci. no explanation can be given of these facts, any more than why certain trees cannot be grafted on others. lastly, an embryo may be developed, and then perish at an early period. this latter alternative has not been sufficiently attended to ; but i believe, from observations communicated to me by mr. hewitt, who has had great experience in hybridising pheasants and fowls, that the early death of the embryo is a very frequent cause of sterility in first crosses. mr. salter has recently given the results of an examination of about 500 eggs produced from


in hybridising pheasants and fowls, that the early death of the embryo is a very frequent cause of sterility in first crosses. mr. salter has recently given the results of an examination of about 500 eggs produced from various crosses between three species of gallus and their hybrids ; the majority of these eggs had been fertilised ; and in the majority of the fertilised eggs, the embryos had either been partially developed and had then perished, or had become nearly mature, but the young chickens had been unable to break through the shell. of the chickens which were born, more than four - fifths died within the first few days, or at latest weeks, “ without any obvious cause, apparently from mere inability to live ; ” so that from the 500 eggs only twelve chickens were reared. with plants, hybridised embryos probably often perish in a like manner ; at least it is known that hybrids raised from very distinct species are sometimes weak and dwarfed, and perish at an early age ; of which fact max wichura has recently given some striking cases with hybrid willows. it may be here worth noticing that in some cases of parthenogenesis, the embryos within the eggs of silk moths which had not been fertilised, pass through their early stages of development and then perish like the embryos produced by a cross between distinct species. until becoming acquainted with these facts, i was unwilling to believe in the frequent early death of hybrid embryos ; for hybrids, when once born, are generally healthy and long - lived, as we see in the case of the common mule. hybrids, however, are differently circumstanced before and after birth : when born and living in a country where their two parents live, they are generally placed under suitable conditions of life. but a hybrid partakes of only half of the nature and constitution of its mother ; it may therefore before birth, as long as it is nourished within its mother ’ s womb, or within the egg or seed produced by the mother, be exposed to conditions in some degree unsuitable, and consequently be liable to perish at an early period ; more especially as all very young beings are eminently sensitive to injurious or unnatural conditions of life. but after all, the cause more probably lies in some imperfection in the original act of impregnation, causing the embryo to be imperfectly developed, rather than in the conditions to which it is subsequently exposed. in regard to the ste


. but after all, the cause more probably lies in some imperfection in the original act of impregnation, causing the embryo to be imperfectly developed, rather than in the conditions to which it is subsequently exposed. in regard to the sterility of hybrids, in which the sexual elements are imperfectly developed, the case is somewhat different. i have more than once alluded to a large body of facts showing that, when animals and plants are removed from their natural conditions, they are extremely liable to have their reproductive systems seriously affected. this, in fact, is the great bar to the domestication of animals. between the sterility thus superinduced and that of hybrids, there are many points of similarity. in both cases the sterility is independent of general health, and is often accompanied by excess of size or great luxuriance. in both cases the sterility occurs in various degrees ; in both, the male element is the most liable to be affected ; but sometimes the female more than the male. in both, the tendency goes to a certain extent with systematic affinity, for whole groups of animals and plants are rendered impotent by the same unnatural conditions ; and whole groups of species tend to produce sterile hybrids. on the other hand, one species in a group will sometimes resist great changes of conditions with unimpaired fertility ; and certain species in a group will produce unusually fertile hybrids. no one can tell, till he tries, whether any particular animal will breed under confinement, or any exotic plant seed freely under culture ; nor can he tell till he tries, whether any two species of a genus will produce more or less sterile hybrids. lastly, when organic beings are placed during several generations under conditions not natural to them, they are extremely liable to vary, which seems to be partly due to their reproductive systems having been specially affected, though in a lesser degree than when sterility ensues. so it is with hybrids, for their offspring in successive generations are eminently liable to vary, as every experimentalist has observed. thus we see that when organic beings are placed under new and unnatural conditions, and when hybrids are produced by the unnatural crossing of two species, the reproductive system, independently of the general state of health, is affected in a very similar manner. in the one case, the conditions of life have been disturbed, though often in so slight a degree as to be inappreciable by us ; in the other case, or that of hybrids, the external conditions have remained


very similar manner. in the one case, the conditions of life have been disturbed, though often in so slight a degree as to be inappreciable by us ; in the other case, or that of hybrids, the external conditions have remained the same, but the organisation has been disturbed by two distinct structures and constitutions, including of course the reproductive systems, having been blended into one. for it is scarcely possible that two organisations should be compounded into one, without some disturbance occurring in the development, or periodical action, or mutual relations of the different parts and organs one to another or to the conditions of life. when hybrids are able to breed inter se, they transmit to their offspring from generation to generation the same compounded organisation, and hence we need not be surprised that their sterility, though in some degree variable, does not diminish ; it is even apt to increase, this being generally the result, as before explained, of too close interbreeding. the above view of the sterility of hybrids being caused by two constitutions being compounded into one has been strongly maintained by max wichura. it must, however, be owned that we cannot understand, on the above or any other view, several facts with respect to the sterility of hybrids ; for instance, the unequal fertility of hybrids produced from reciprocal crosses ; or the increased sterility in those hybrids which occasionally and exceptionally resemble closely either pure parent. nor do i pretend that the foregoing remarks go to the root of the matter ; no explanation is offered why an organism, when placed under unnatural conditions, is rendered sterile. all that i have attempted to show is, that in two cases, in some respects allied, sterility is the common result, — in the one case from the conditions of life having been disturbed, in the other case from the organisation having been disturbed by two organisations being compounded into one. a similar parallelism holds good with an allied yet very different class of facts. it is an old and almost universal belief founded on a considerable body of evidence, which i have elsewhere given, that slight changes in the conditions of life are beneficial to all living things. we see this acted on by farmers and gardeners in their frequent exchanges of seed, tubers, & c., from one soil or climate to another, and back again. during the convalescence of animals, great benefit is derived from almost any change in their habits of life. again, both with plants and animals, there is


, & c., from one soil or climate to another, and back again. during the convalescence of animals, great benefit is derived from almost any change in their habits of life. again, both with plants and animals, there is the clearest evidence that a cross between individuals of the same species, which differ to a certain extent, gives vigour and fertility to the offspring ; and that close interbreeding continued during several generations between the nearest relations, if these be kept under the same conditions of life, almost always leads to decreased size, weakness, or sterility. hence it seems that, on the one hand, slight changes in the conditions of life benefit all organic beings, and on the other hand, that slight crosses, that is crosses between the males and females of the same species, which have been subjected to slightly different conditions, or which have slightly varied, give vigour and fertility to the offspring. but, as we have seen, organic beings long habituated to certain uniform conditions under a state of nature, when subjected, as under confinement, to a considerable change in their conditions, very frequently are rendered more or less sterile ; and we know that a cross between two forms, that have become widely or specifically different, produce hybrids which are almost always in some degree sterile. i am fully persuaded that this double parallelism is by no means an accident or an illusion. he who is able to explain why the elephant and a multitude of other animals are incapable of breeding when kept under only partial confinement in their native country, will be able to explain the primary cause of hybrids being so generally sterile. he will at the same time be able to explain how it is that the races of some of our domesticated animals, which have often been subjected to new and not uniform conditions, are quite fertile together, although they are descended from distinct species, which would probably have been sterile if aboriginally crossed. the above two parallel series of facts seem to be connected together by some common but unknown bond, which is essentially related to the principle of life ; this principle, according to mr. herbert spencer, being that life depends on, or consists in, the incessant action and reaction of various forces, which, as throughout nature, are always tending towards an equilibrium ; and when this tendency is slightly disturbed by any change, the vital forces gain in power.


front page titles ( by subject ) chap. vi. : the reason why interest was lowered one half after the conquest of the indies. - complete works, vol. 2 the spirit of laws the online library of liberty a project of liberty fund, inc. search this title : chap. vi. : the reason why interest was lowered one half after the conquest of the indies. - charles louis de secondat, baron de montesquieu, complete works, vol. 2 the spirit of laws the complete works of m. de montesquieu ( london : t. evans, 1777 ), 4 vols. vol. 2. about liberty fund : the text is in the public domain. fair use statement : the reason why interest was lowered one half after the conquest of the indies. garcilasso informs us, ‡ that in spain, after the conquest of the indies, the interest, which was at ten per cent. fell to five. this was a necessary consequence. a great quantity of specie being all of a sudden brought into europe, much fewer persons had need of money. the price of all things increased, while the value of money diminished ; the proportion was then broken, and all the old debts were discharged. we may recollect the time of the system ; * when every thing was at a high price except specie. those who had money after the conquest of the indies, were obliged to lower the price or hire of their merchandize ; that is, in other words, their interest. from this time they were unable to bring interest to its ancient standard, because the quantity of specie brought to europe has been annually increasing. besides, as the public funds of some states, founded on riches procured by commerce, gave but a very small interest, it became necessary for the contracts of individuals to be regulated by these. in short, the course of exchange having rendered the conveying of specie from one country to another remarkably easy, money cannot be scarce in a place where they may be so readily supplied with it, by those who have it in plenty. [ ‡ ] history of the civil wars of the spaniards in the west indies. [ * ] in france, mr. law ’ s project was called by this name.


sugar might not be the infant pain reliever clinicians have long thought it to be, according to a study in the lancet. at a hospital in london, researchers randomly assigned 44 newborns to receive a squirt of either sugared or plain water before pricking their heels. ( the heel prick is a common method for drawing infants ' blood. ) meanwhile, electroencephalography ( eeg ) electrodes measured the infants ' pain - specific brain activity. previous studies have found that newborns exhibit fewer grimaces and other facial expressions of pain when given sugared water before a procedure. despite that, in this study the eegs showed no difference in pain between children given sugared or plain water. caveat : activity in the targeted brain regions might not capture the entirety of infant pain, an accompanying editorial said. the small number of infants in the study meant that the researchers would only have been able to detect a large difference between the two groups. - oral sucrose as an analgesic drug for procedural pain in newborn infants : a randomised controlled trial internal clocks : tissue from hair follicles can reveal where people are in the circadian rhythm that governs their sleeping and waking periods, according to a study in the proceedings of the national academy of sciences. the genes regulating this so - called circadian clock leave traces of their activity throughout the body. previously, the researchers tried sampling blood and mouth - tissue cells for dna to track circadian phases. they decided that collecting follicle cells, attached to the bottom of plucked chin or head hairs, would be an easier and less - invasive method. in one experiment, they found that follicle cells from an average of 10 hairs contained enough information to differentiate among workers with morning, afternoon or night shifts. caveat : the study doesn ' t include the costs of processing hair follicles. the technique, which could help diagnose erratic or slow - to - adapt circadian clocks, needs to be improved before it ' s ready for clinical use, the researchers said. lung cancer : the world ' s most prescribed anti - diabetes drug halved the eventual size of lung tumors in mice, according to a study in cancer prevention research. metformin, typically the first choice for treating type 2 diabetes, may slow tumor growth by regulating enzymes that become overactive during cancer. the researchers injected cancer - prone mice with a carcinogen specific to cigarette smoke, and then gave them either a placebo or moderate doses of metformin. after 13


, may slow tumor growth by regulating enzymes that become overactive during cancer. the researchers injected cancer - prone mice with a carcinogen specific to cigarette smoke, and then gave them either a placebo or moderate doses of metformin. after 13 weeks, the lung tumors in metformin - fed mice were 38 % to 53 % smaller than those in the placebo - fed mice on average. more - potent, injected doses of metformin led to a 72 % tumor reduction. caveat : as with all animal studies, the findings might not apply to human subjects. the national cancer institute is planning a clinical trial to test metformin in people at highest risk of developing lung cancer. brain exercises : reading and other cognitive exercises compress late - life dementia into a shorter but more - rapid decline, according to a study in neurology. at the beginning of the study, 1, 157 dementia - free seniors reported how often they read newspapers, magazines and books ; listened to the radio ; watched television ; played games like cards or crosswords and visited museums. every three years, the researchers tested a subset of the participants for cognitive impairment, and followed those patients for another 5. 7 years on average. cognitive exercise appeared to delay dementia. every one - point increase on a five - point mental - activity scale corresponded to an average 52 % slower cognitive impairment at first. but the exercises appeared to have the opposite effect on subjects who had developed alzheimer ' s : for every one - point increase on the scale, cognitive skills declined 42 % more quickly. caveat : the researchers tested each participant fewer than four times on average, and the participants reported their cognitive exercises just once. migraine : researchers discovered the first common gene linked to migraine risk, according to their report in nature genetics. the researchers compared dna samples from 2, 731 migraine sufferers to 10, 747 otherwise similar subjects, examining more than 400, 000 dna sequences per participant. a variation in only one sequence, on the long arm of chromosome 8, appeared to have any effect on the debilitating condition. the researchers confirmed their initial findings by examining this sequence in another 3, 202 people with migraine and 40, 062 controls. overall, 24. 3 % of migraine sufferers and 20. 6 % of non - sufferers carried the variant — an 18 % higher rate for sufferers. the sequence ' s location, between two genes that help regulate the neurotransmitter glutamate, provides fresh clues for understanding


. 6 % of non - sufferers carried the variant — an 18 % higher rate for sufferers. the sequence ' s location, between two genes that help regulate the neurotransmitter glutamate, provides fresh clues for understanding and treating migraine. caveat : all subjects were european, and all migraine sufferers were recruited from specialized headache clinics. it ' s unclear whether the variant is as common, or as closely associated with migraine, in other populations. low - carbohydrate diets : low - carbohydrate diets based on animal protein appear to shorten dieters ' lives, while those based on vegetable proteins appear to increase longevity, according to a study in annals of internal medicine. researchers tracked 85, 168 female nurses between 1980 and 2006. they also tracked 44, 548 male health - care professionals ( such as optometrists and veterinarians ) between 1986 and 2006. during that time, about 16 % of the participants died. the participants who consumed few carbohydrates and the greatest proportion of animal protein and fat were 23 % more likely to die than those who consumed the least. on the other hand, the mortality rate was 20 % lower for participants on low - carb diets who consumed the most vegetable protein and fat, compared to those who consumed the least. caveat : smaller differences in diet — for example, between diets in the 40th and 60th percentiles for carbohydrates, instead of the top and bottom 10 % — were mostly insignificant. the researchers adjusted their analyses for age, physical activity and smoking, but not race, income or education. esophageal cancer : the most popular anti - osteoporosis medications may boost the risk of esophageal cancer, according to a study in the british medical journal. the food and drug administration raised the possibility last year of a link between oral bisphosphonates and esophageal cancer, based on case reports it collected. yet a recent analysis of a large british patient database suggested that the medications weren ' t to blame for the cancer. the bmj study used the same database, but tracked patients for nearly twice as long : 7. 7 years versus 4. 5 years on average. over the longer period, a greater proportion of the 2, 954 patients with esophageal cancer had used oral bisphosphonates, compared to a control group. ( there was no association between the


. 5 years on average. over the longer period, a greater proportion of the 2, 954 patients with esophageal cancer had used oral bisphosphonates, compared to a control group. ( there was no association between the medication and gastric or colorectal cancer. ) the risk was concentrated among patients who had received at least 10 prescriptions for oral bisphosphonates. they were 93 % more likely to get esophageal cancer than subjects who received no prescriptions. the overall risk for esophageal cancer in europe and north america is about 1 in 1, 000. caveat : the data didn ' t show whether patients who were prescribed oral bisphosphonates actually used them, or whether they followed the instructions meant to reduce esophageal irritation. - oral bisphosphonates and risk of cancer of oesophagus, stomach, and colorectum : case - control analysis within a u. k. primary care cohort heart health : margarine fortified with omega - 3 fatty acids appears not to prevent second heart attacks, according to a study in the new england journal of medicine. dutch researchers gave 4, 837 elderly heart - attack survivors, all taking " state - of - the - art " medications, each a 40 - month supply of margarine. one - quarter of patients received standard margarine, while the others were given margarine laced with omega - 3s derived from fish, plants or a mix of the two. by the end of the 40 months, 14 % of the patients had another heart attack, a stroke or other major cardiovascular trauma. the type or amount of margarine the patients consumed had no significant influence on this rate. the findings contrast with earlier studies, which found that omega - 3s helped to protect the heart. one possible explanation, according to the researchers : the increasing use of highly effective cardiovascular drugs, particularly cholesterol - reducing statins, could have outweighed any benefits of omega - 3s. caveat : if the study had enrolled more patients, particularly women, it would have had more power to detect possible omega - 3 effects. nearly 80 % of the participants were male, yet the fortified margarines seemed more effective in women.


sin has a lot of moving parts. it features seven ancient figures, some of whom have instant name recognition ( jesus, paul, augustine ) and some of whom do not ( valentinus, marcion, justin, origen ). jesus and paul were both jews whose ideas about sin related in positive and creative ways to the sacrificial cult of jerusalem ’ s temple. marcion, valentinus and justin, all gentiles, shaped subsequent centuries of christian doctrine by arguing about how to read jewish scriptures ( which by 300 ce will become the ‘ old testament ’ for some churches ), how to identify the god of the jewish bible ( is he the father of christ, or someone else? ), how to understand evil, and, thus, how to understand sin. origen and augustine, finally, were two towering geniuses of the early church. dealing with the same scriptural and doctrinal points of principle, they each framed huge, complex, and contrasting theologies. not only do their ideas of sin contrast dramatically : so too do their ideas about the universe, about humanity, and about god. learn more about sin : the early history of an idea at the princeton university press website. page 99 introduces these last two men, and sets up these contrasts. according to origen, all would be saved ; according to augustine, most were damned. according to origen, since god is just, he gave humanity free will so that a person could choose whether or not to sin. according to augustine, since god is just, he condemned all humanity to a broken will as part of the price of original sin. according to origen, even satan will at last be redeemed ; according to augustine, even babies, if unbaptized, go to hell. augustine is one of history ’ s winners. his views prevailed. in their secular refraction, they continue to affect even american public policy : according to augustine, since sex is a sinful act, its only morally admissible function is procreation. any other use of sex other than for procreation – as the expression of affection, say – is to be condemned. the current struggles over whether u. s. government funds can or should be used to provide americans with access to contraception is an early 21st - century spin - off of augustine ’ s early fifth - century arguments on the nature of sin.


archosaurs ( [ greek for ' ruling lizards ' ) are a group of diapsid reptiles that first evolved from archosauriform ancestors during the olenekian ( lower triassic period ). they are represented today by birds and crocodiles. archosaurs are set apart by having socketed teeth ( a feature that inspired the traditional name, ' thecodonts ', for the triassic forms ) and four - chambered hearts, among other characteristics. most early forms were carnivores, with narrow serrated meat - tearing teeth. their " reptilian " metabolism seem to have given them a clear advantage over the mammal - like therapsids that were their contemporaries in the arid interiors and strong monsoon climates that were the natural result of the single world - continent, pangaea. thus, whereas the permian was dominated by synapsids, the triassic came to be dominated by sauropsids. there are two primary groups of archosaurs — the ornithodira which were insignificant during the middle triassic but in the late triassic radiated as the dinosaurs and pterosaurs ; and the crurotarsi, which were the predominant group at this time, and included a number of purely triassic groups like the rauisuchians, the phytosaurs, and the herbivorous aetosaurs, as well as the ancestors of the crocodilians. a number of these archosaur groups - chiefly those large crurotarsi that are in pre - cladistic books called the thecodonts - became extinct 195 million years ago, during the triassic - jurassic extinction event. the survivors - the dinosaurs and the pterosaurs among the ornithodira, and first the sphenosuchia and protosuchia then their descendants the crocodilia among the crurotarsi - flourished during the jurassic and cretaceous periods. the dinosaurs dominated the land, the pterosaurs and later another archosaurian group, the birds, dominated the air, and the crocodiles dominated the rivers and swamps and even invaded the seas ( the teleosaurs and metriorhynchidae ). most of these taxa perished 65 million years ago, during the cretaceous - tertiary extinction event. the only groups of archosaurs to continue through to the tertiary and, ultimately, to the present day, are the birds ( which are descended from the dinosaurs ) and the crocodylia ( which include all modern crocodiles, alligators, and ghari


of archosaurs to continue through to the tertiary and, ultimately, to the present day, are the birds ( which are descended from the dinosaurs ) and the crocodylia ( which include all modern crocodiles, alligators, and gharials ). birds are traditionally treated as a separate class, aves, while the rest of the archosaurs are treated as a subclass or infraclass, archosauria, within the class reptilia. more recently, with the cladistic method dominating biology, only monophyletic groups are considered valid and birds are included within the division archosauria. avesuchia ` - - archosauria | - - crurotarsi | | -? ctenosauriscidae | ` - - crocodylotarsi | | - - ornithosuchidae | ` - - + - - phytosauria | ` - - suchia | | - - prestosuchidae | ` - - rauisuchiformes | | - - aetosauria | ` - - rauisuchia | | - - rauisuchidae | ` - - + - - paracrocodylomorpha | ` - - crocodylomorpha ( crocodiles and relatives ) ` - - ornithodira | - - pterosauromorpha | | - - scleromochlus | ` - - pterosauria ` - - dinosauromorpha ` - - dinosauriformes ` - - dinosauria | - - ornithischia ` - - saurischia ` - - aves ( birds ) - benton, m. j. ( 2004 ), vertebrate paleontology, 3rd ed. blackwell science ltd - carroll, r. l. ( 1988 ), vertebrate paleontology and evolution, w. h. freeman and co. new york | this page uses content from wikipedia. the original article was at archosauria. the list of authors can be seen in the page history. as with paleontology wiki, the text of wikipedia is available under the gnu free documentation license. |


the tumor ( images a & b ) shows lobules of cells similar to basal cells with masses of small keratinocytes surrounded by larger, palisading cells ( image c ) on the periphery of the lobules. these uniform tumor cells possess large, oval, elongated nuclei and scant, poorly defined cytoplasm. there are no intercellular bridges. the nuclear size is relatively uniform and identifiable mitoses ( image d ) are normal, although variable. the surrounding myofibroblastic stroma ( image c ) is arranged in parallel bundles. there are an abundance of keratotic cysts and occasional retraction lacunae ( image c ) where the stroma retracts from the tumor. the odontogenic keratocyst is lined by a two to five layer squamous cell epithelium with a well - differentiated basal layer. it forms keratin, possesses no granulocytic cell layer or rete ridges, and may consist of one large cyst, or multiple microcysts. the parakeratotic odontogenic cyst ( images e & f ) possesses a thin lining of stratified squamous epithelium with a palisading basal layer and a corrugated surface of parakeratin. the epithelium surrounds a cyst cavity containing keratin. the orthokeratotic odontogenic cyst ( image g ) also possesses a thin surrounding epithelium but without a corrugated surface. there is a well - developed granular layer and a flattened or cuboidal, non - palisading, basal layer. this cyst cystcontains orthokeratin.


if you take a prescription or an over - the - counter drug, and you can answer yes to any of these other questions, then you may be experiencing a drug interaction or conflict that is having an negative affect on your health : - do you take more than one drug - prescription or over - the - counter? - do you take vitamins or other supplements? - do you ever drink grapefruit juice, eat licorice or chocolate? - do you enjoy a glass of wine, a bottle of beer or another alcoholic beverage? drug - to - drug, drug - to - supplement, drug - to - food and drug - to - alcohol conflicts and interactions may simply give you a bit of intestinal discomfort - or they may kill you. we hear too frequently in the news about a celebrity who has died because of conflicts from drugs, in particular. sometimes we hear them labeled as overdoses. but overdoses can result from a drug that was taken in its prescribed quantity, then its effect was altered by the presence of another substance like another drug or alcohol. michael jackson, heath ledger, anna nicole smith, and others are all considered to have died from drug interactions. here are some examples of drug conflicts and interactions that may surprise you. drug with other drug conflicts : if you take more than one drug, then your drugs may be getting in each other ' s way. the more different medications you take, the more chances there are of conflicts. according to the institute for safe medication practices, almost 40 % of americans take four or more different drugs. here are some examples of problems that can occur when two conflicting drugs are taken by the same patient : antihistimines, those usually over - the - counter drugs we take for runny noses, sneezing, congestion or watery eyes, can increase the depressive effects of many sedatives, tranquilizers, high blood - pressure medications or medicines for depression. in turn, that makes patients sleepier and more fatigued, which can be deadly to the patient or others if the patient tries to drive a car, operate heavy machinery or any other activity that requires concentration. antihistimines can also cause an increase in blood pressure or speed up the heart rate of patients who take blood pressure - reducing medications. acid reducers like prilosec ( omeprazole ), nexium or others known as drugs to treat gerd ( gastrointestinal esophageal reflux disease ) will interact with any drug that contains cimt


. acid reducers like prilosec ( omeprazole ), nexium or others known as drugs to treat gerd ( gastrointestinal esophageal reflux disease ) will interact with any drug that contains cimtidine, such as some asthma drugs, seizure drugs or warfarin ( coumadin ), used as a blood thinner. cardorone ( also called amiodarone ) conflicts with the cholesterol - lowering drug, zocor ( simvastatin ) and can lead to kidney failure or death if the dose of zocor is 20 mg or higher. cardarone also conflicts with coumadin. there may be thousands of examples of these interaction problems. be sure to double check any possible conflicts before you begin taking a new drug that could possibly conflict with a drug you already take. drug with vitamins, minerals or herbal supplement conflicts : at least 50 % of americans take dietary supplements according to the federal government. vitamins, minerals, amino acids, herbs, botanicals and other substances that many of us call " natural " are being ingested in hopes of improving our health. whether or not most of them truly help us is not the question here. but whether or not they might have an impact on the effectiveness of drugs we take is something we must all be concerned with. here are some examples of drug and supplement conflicts : vitamin e and ginko biloba can interact with coumadin ( also called warfarin, jantoven, marevan, lawarin, waran and warfant ), increasing its blood - thinning properties and putting those who take it at risk for increased bleeding. ginseng also interacts with coumadin and also creates potential bleeding problems for people who take heparin, aspirin or nsiads ( ibuprofen, naproxen and others ). ginseng can also cause headaches, nervousness or hyperactivity among those who take mao inhibitors. st. john ' s wort may create problems for those who take antidepressants. drug with food and alcohol conficts : according to the food and drug administration, some foods and all alcoholic beverages can increase how the body metabolizes some drugs, meaning the drug will be absorbed and used by the body in a different way than it was intended to. this can increase, decrease or neutralize the effect of the drug. here are some examples : grapefruit juice can cause problems for people


, meaning the drug will be absorbed and used by the body in a different way than it was intended to. this can increase, decrease or neutralize the effect of the drug. here are some examples : grapefruit juice can cause problems for people who take certain blood - pressure lowering medications or for those who take cyclosporin after an organ transplant. there may be dozens of other drugs that grapefruit juice affects, causing problems for those who drink it along with those drugs. ( learn more about avoiding these drug conflicts and interactions. ) chocolate - who can live without chocolate? some of us need to - because the drugs we take will become problematic if we eat chocolate, too. for example, anyone ( including children ) who takes a stimulant drug such as ritalin or a sedative - type drug like ambien must avoid any food that includes caffeine, including chocolate and coffee. chocolate can also cause problems for anyone who takes mao inhibitors for depression or parkinson ' s disease. mao inhibitors include drugs like nardil ( phenelzine ) or parnate ( tranylcypromine ). in fact, chocolate isn ' t the only food that needs to be avoided by those who take mao inhibitors. here is a list of foods to avoid, which include smoked, aged or pickled meat or fish, sauerkraut, aged cheeses, beef or chicken liver and red wines. licorice, another favorite, needs to be avoided by people who take certain blood - pressure lowering drugs like digitalis ( also called digoxin, digitoxin, cardoxin, digitek, lanoxicaps or lanoxin. ) with so many ways to negatively affect the drugs we take to improve our health, it makes sense to avoid those drug conflicts and interactions. whenever your provider gives you a new prescription for a drug, or if you decide to use an over - the - counter drug to address difficult symptoms, be sure you make yourself aware of the potential conflicts, then avoid them. from medline plus ( national library of medicine ) from the fda


may 04 2010 today we talked about hydrogen and how it can be used to power vehicles. of the forty - four free response questions on previous a. p. exams, none have addressed hydrogen power, so mr. willard said this would be “ good knowledge to have in our pockets. ” first we reviewed what we already knew about hydrogen. hydrogen is the most abundant element in the universe. despite this fact, there is almost none in the troposphere, and this is because hydrogen has a very low density and so it rises. additionally, hydrogen is very unstable, so it likes to bond with things ( i. e. with oxygen, thus water ). in a hydrogen - powered car, the traditional internal combustion engine is replaced with a fuel cell. here is a link to a video we watched in class about how a fuel cell works : how a fuel cell works : inside a hydrogen - powered car ( http : / / auto. howstuffworks. com / fuel - efficiency / alternative - fuels / dangerous - hydrogen - fuel1. htm ) as with every energy source, there are pros and cons. the pros to a hydrogen - powered car is that water is its only emission, it is a strategy for reducing fossil fuel use, and hydrogen is the most abundant element in the universe. on the flip side, the cons to a hydrogen - powered car are that we have to harvest the hydrogen or “ make it ” ( which requires energy input ), since this source of energy is new, the infrastructure for hydrogen power is not there, and that we can ’ t simply convert petro - gas stations to hydrogen gas stations. perhaps we can add on to our petro - gas stations, and if we harvest the hydrogen or “ make ” the hydrogen by generating energy from renewable resources such as wind or solar power, technically the energy is still clean. but if we generate the energy for hydrogen from a coal - based power plant, then we ’ re just moving the source, but the impact is still the same. hydrogen can be “ harvested ” or “ made ” from electrolysis ( splitting water ), from biomass, and from fuel. the u. s. government is currently funding research on hydrogen power in the state of california. hydrogen power is still very much in the research and development stage. hope this helped! below is a picture of a typical hydrogen fuel cell :


the list has been arranged, as possible, in reverse chronological order. i should note that the contents have been lightly edited to reduce entry length ; almost all of these edits have removed references to recent sources in the outside literature which are not further identified. my apologies for this to the authors, but readers should of course consult the original sources to get the full picture, often extending well beyond wallace studies per se.... how is it that the memes of poetry remained a strong presence in the life of wallace but disappeared from the life of darwin even though both men were very much involved in scientific research that led both to the same revolutionary paradigm of natural selection? perhaps the answer to this question may be found in a famous clash between the two scientific titans. for as himmelfarb ( 1986 ) has remarked, ' wallace not only had the distinction of being the first darwinist ; he was also the first renegade darwinist '. and the issue on which wallace became a ' renegade ' was hardly trivial. whereas darwin believed that the science of evolution could completely account for the human species, wallace had his doubts. his ' little heresy ' as he called it was actually not so little, for he questioned whether the science of natural selection could account for ' the moral and higher intellectual nature of man '... - - bryce christensen, october 2012. changing english : studies in culture and education 18 ( 4 ) : 400.... the first author who expected mimicry by light was wallace ( 1878 ) himself, who erroneously supposed click beetles for firefly mimics. nevertheless, their light is different and they also appeared inedible too ( harvey 1956 ). cockroaches are fat and tasty, so the mimic is at the place. one mimicry by light ( aggressive, batesian - wallacian or peckhammian ) is actually known ( lloyd 1965, 1984 ) : predaceous fireflies photuris ( and also bicellychonia ) mimic the flash responses of females of other, up to five different ( lloyd 1983 ) species, attract males, and catch them, often during flight... - - peter vrsansky et al., september 2012. naturwissenschaften 99 ( 9 ) : 748.... background matching prey coloration and its adaptive features have been recognized by biologists for a long time. the related idea that prey animals can decrease their probability of being detected through behavioural features was already discussed by alfred russel wallace...


... background matching prey coloration and its adaptive features have been recognized by biologists for a long time. the related idea that prey animals can decrease their probability of being detected through behavioural features was already discussed by alfred russel wallace.... it has been shown experimentally that background matching effectively reduces predation risk imposed by predators, for example, in fishes and birds. preference for backgrounds that reduce the risk of detection has thus been suggested to be an important and wide spread strategy among prey animals to decrease their predation risk. it is also a common assumption that prey animals have been selected to actively prefer visually matching backgrounds. however, considering the popularity of this idea, surprisingly few experimental studies testing it exist... - - karin kjernsmo & sami merilaita, august 2012. proceedings of the royal society of london, series b, biological sciences 279 ( 1745 ) : 4192.... after planting doubts about sexual selection as the unique explanation, wallace ( 1868 ) associated sexual dichromatism with the nesting habits of birds in relation to the risk of nest predation. he considered that, assuming that ( i ) incubation attendance by either sex promotes cryptic plumage in open nesters, but ( ii ) not in cavity or domed nesters, ( iii ) conspicuous sexual monochromatism should be associated with cavity or domed nesting, and ( iv ) sexual dichromatism with conspicuous males and cryptic females should be related to open nesting ( table 1 ). wallace ( 1868 ) offered support for the two last predictions by listing 23 phylogenetically related groups of birds ( i. e. families or genera ) with conspicuous monochromatism nesting in cavities or domed nests and seven families with bright males and dull females with open nesting habits. wallace ( 1868, 1889 ) also predicted that because of the higher phylogenetic lability of plumage colour, changes in nesting habits would come first and be followed by changes in coloration. darwin ( 1871 ) disagreed with this view and forcefully argued that plumage coloration could select for changes in nesting habits while the opposite was less plausible. in nearly a century and a half elapsed since wallace first presented his theory on avian sexual dichromatism in relation to nesting habits, few attempts have been made to empirically check its validity despite the attention that sexual dichromatism as variable reflecting the strength of sexual selection in different bird species has received during the last decades ( see for instance, amundsen & parn, 2006 )