open flowers. bumble bees were potentially generalists as they induced an important fruit production of the two plant types and a good recruitment in the open - and tubular - flower plant treatments. our results on the reproductive success and recruitment of single - guild plant treatments indicate that there are strong functional group identity effects since our plant functional groups responded differently to our pollinator functional groups. however, the functional diversity of both the plant and pollination treatments was also important. plant reproductive success tended to increase with pollinator functional diversity when the number of seeds per fruit was considered, and with both plant and pollinator functional diversity when the number of fruits per plant was considered ( figures 2b and 2d ). although recruitment in single - guild plant treatments was mainly affected by the identity of functional groups, the effect of functional diversity was dramatic in the mixed plant treatment. natural recruitment of plant communities visited by mixed pollinator guilds was largely above that in other pollination treatments. pollination by syrphids alone allowed the reproduction of open flowers but not tubular flowers, as expected from the specialisation of syrphids. more surprisingly, however, bumble bees failed to be efficient generalist pollinators. most of their visits occurred on tubular flowers ( figure 4 ), resulting in a relatively poor recruitment of open flowers. the only pollination treatment that achieved a high recruitment of both open and tubular flowers when they were mixed, was the one containing the two insect functional groups ( figure 3, right ). when syrphids and bumble bees simultaneously pollinated mixed plant communities, they each focused on their target plant functional group, leading to more efficient visits and a better distribution of visits among plant functional groups ( figure 4 ). ultimately, it was the pollination treatment with both pollinator functional groups that produced the highest richness and density of natural recruitment. consequently, since most natural plant communities contain both open and tubular flowers, pollinator functional diversity should strongly enhance the persistence of these communities. although our experimental system differed from natural communities, and information about the reciprocal effects of the functional diversity of plant communities on the diversity of pollinator communities would be useful, our study indicates that the functional diversity of plant – pollinator interaction webs may be critical for the persistence and functioning of ecosystems and should be carefully monitored and protected. the loss of pollinator functional diversity is likely to trigger plant population decline or extinctions, which in turn are likely to affect the structure and composition of natural plant communities and the productivity of many agroecosytems that rely on


and protected. the loss of pollinator functional diversity is likely to trigger plant population decline or extinctions, which in turn are likely to affect the structure and composition of natural plant communities and the productivity of many agroecosytems that rely on insect pollination. ultimately, higher trophic levels may be affected since the diversity and biomass of consumers depend on primary production. our results strongly suggest that the functional diversity of complex interaction webs plays a crucial role in the sustainability of ecosystems. materials and methods experimental plant communities at the beginning of spring 2003, plant communities were set up in a meadow that remained almost undisturbed for 10 years at the station biologique de foljuif, france, 80 km southwest of paris. prior to the establishment of the communities, soil was sterilized by injecting 120 °c steam ( 30 min ) to destroy the seed bank and soil pathogens. in each of the 36 4 - m2 plots, a total of 30 adult plants were planted on a grid, spaced 25 cm from each other, to minimize competition and homogenise spatial distribution. thus, plant density was the same in all experimental plots. we selected a moderate density to maintain within - and among - species competition to a low level, and to allow enough space for future recruitment in the plots. each of these plant communities was enclosed in a 2 - m – high nylon mesh cage in order to eliminate natural pollinator visitation. during the flowering seasons ( june – july 2003 and 2004 ), pollinators were captured around the study area and introduced into the cages. the relative abundance of pollinator species in the various pollination treatments reflects their natural abundances. from preliminary observations, we had noticed that, in order to have no more than three insects active at the same moment in a 4 - m2 plot, it was necessary to put about eight syrphid flies, or six bumble bees, or a mixture of six syrphids and four bumble bees in each pollination cage. each pollination round in a given plot included 200 visits in the year 2003 and 300 in the year 2004. in total, each plot received either four ( in 2004 ) or five ( in 2003 ) pollination rounds, leading to a total of 1, 000 visits per plot in 2003 and 1, 200 in 2004. bumble bees needed approximately 30 min after introduction in the cages to calm down and start to pollinate. in the pollination treatment with both pollinator guilds, we then introduced syrphids, which


2003 and 1, 200 in 2004. bumble bees needed approximately 30 min after introduction in the cages to calm down and start to pollinate. in the pollination treatment with both pollinator guilds, we then introduced syrphids, which started to pollinate immediately. mean visitation time was not significantly different between insects in the cages and in nature. this was true both for bumble bees ( mean visitation time in cages : 3. 25 ± 0. 92 s, mean visitation time in nature : 2. 91 ± 1. 33 s, t = 1. 51, df = 96, p = 0. 133 ) and for syrphids ( mean visitation time in cages : 40. 21 ± 8. 89 s, mean visitation time in nature : 35. 38 ± 14. 75 s, t = 0. 77, df = 12, p = 0. 45 ). measurement of reproductive success one month after the first pollination treatments, we counted the total number of fruits on each plant, except for m. guttatus and m. officinalis in which fruits cannot be counted without collecting them. we randomly took five fruits per plant of each species to estimate the number of seeds per fruit. measurement of recruitment richness and density recruitment richness and density were estimated during the second ( april 2004 ) and third ( april 2005 ) year of the experiment by counting the number of seedlings of each species in four 1, 600 - cm2 quadrats in each plot. statistical analyses were performed using sas 8. 2 software. for the analysis of plant reproductive success, we log - transformed the data to ensure normality. we standardized the data by species using the formula : x − μ / σ ( where μ = the mean and σ = the standard deviation of number of fruits or number of seeds per fruit for a given plant species ) in order to make the data comparable among the various species and functional groups. we used a mixed analysis of variance ( anova ) model ( sas proc mixed ), in which the fixed effects were plant treatment, pollination treatment, and their interaction term. to investigate the effects of the various plant and pollination treatments, we subdivided a priori each main effect into two components using orthogonal contrasts. the first contrast tested the effect of the identity of the plant or pollinator functional group, i. e. one group versus the other. the second tested the effect of the functional diversity of the plant or pollination treatment, i. e. single - guild versus


tested the effect of the identity of the plant or pollinator functional group, i. e. one group versus the other. the second tested the effect of the functional diversity of the plant or pollination treatment, i. e. single - guild versus mixed - guild plant or pollination treatments. similarly, we subdivided the interaction into three orthogonal contrasts testing the effects of pollinator functional group identity on each plant guild, and the effect of the functional diversity of both plant and pollination treatments. see table 1 for the construction of the contrasts. for the analysis of plant recruitment, we used a repeated measure anova model ( sas proc mixed ). the fixed effects were pollination treatment, plant treatment, year, and all the interaction terms. the repeated effect was year, and the subject effect was replicate. for recruitment density, data were log transformed. for each year of the experiment, the visitation rate of pollinators on each plant species in the communities with both plant functional groups was analysed using a mixed log - linear model ( glimix macro, sas ). we subdivided the pollination treatment into two effects : pollinator functional diversity ( one or two pollinator functional groups ) and identity of the pollinator functional group ( bumble bees or syrphids ). the model included pollinator species nested within identity of pollinator functional groups, plant species nested within identity of plant functional group, identity of pollinator functional groups, identity of plant functional groups, pollinator functional diversity, and all interaction terms. the replicate was a random effect. we thank carine collin, romain gallet, jean - francois le galliard, jacques gignoux, andy gonzalez, gerard lacroix, gaelle lahoreau, louis lambrecht, manuel massot, naoise nunan, virginie tavernier, and elisa thebault for useful discussions ; and marco banchi, yves bas, mathilde baude, alix boulouis, marion decoust, patricia genet, alexandra kabadajic, mohsen kayal, fanny marlin, and emilie patural for great help in the field and in the lab. we also thank andy gonzalez, andy hector, marcel van der heijden, claire kremen, jane memmott, nick waser, and three anonymous reviewers for constructive and useful comments on the manuscript. we acknowledge the financial support of the quantitative ecology coordinated incentive action ( aci ecologie quantitative ) of the ministry of research ( france ). competing interests.


despite years of reassuring researches, many people still avoid caffeinated coffee because they worry about its health effects. however, according to a recent research, taking one to six cups of coffee in a day could help a great deal in reducing the risk of some diseases. raliat ahmed writes with agency reports. women who drink five or more cups of coffee a day could be protecting themselves against an aggressive form of cancer, says a recent swedish research. although other researches had suggested that coffee which contains a high dose of caffeine poses health risks, scientists believe that people who drink between one or two cups daily have the healthiest arteries. drinking just one cup of a coffee a day could reduce your blood pressure, according to a greek study of 485 people aged 65 to 100. a bristol university study of 600 people found that those who drank a cup of regular coffee performed better in mental tests than those who drank decaffeinated coffee or nothing. another research by a team of scientists from the university of florida also says that taking two cups of coffee a day could keep alzheimer ’ s disease at bay. around 200mg of caffeine, the equivalent of two cups of coffee could prevent the build up of proteins in the brain which have been linked to memory loss associated with the disease. and drinking the equivalent of two cups of coffee 30 minutes before exercise may enhance your performance by providing you with more energy, suggests a study in the international journal of sports medicine. when leadership contacted professor tunde oguntona, a professor in the department of nutrition and dietetics, university of agric, abeokuta, he confirmed that there had been various researches which suggested this type of claim mostly in the united states and europe. “ it is however too early to jump into conclusions at this stage due to the side effects of coffee as a result of its high caffeine content. “ we still need to do more researches to substantiate this claim before it can be put into consideration, especially in this part of the world ”, oguntona said. speaking further, oguntona said that there were however, factors to be put into consideration for this claim to be applicable in nigeria. he stated, “ one basic factor is the quality of health of individuals in the country. the above claim may have been successful because it was carried out on healthy individuals and as such may not be possible here due to health / disease profile of individuals. ” another factor that should be put into consideration is our diet which is different from that of people in


claim may have been successful because it was carried out on healthy individuals and as such may not be possible here due to health / disease profile of individuals. ” another factor that should be put into consideration is our diet which is different from that of people in america and europe. the caffeine intake from three cups a day can reduce the risk of developing ovarian cancer by a fifth, the american medical journal cancer reported in 2008. after studying more than 122, 000 women, researchers found that the benefits were even greater for women who ’ d never been on the contraceptive pill or hrt ( their risk was reduced by 35 and 43 per cent respectively. men who drink three cups of coffee have a 40 per cent lower risk of developing gallstones, according to another study published in the journal of the american medical association. the scientists believe the caffeine stimulates contractions in the gall bladder, helping to remove any small stones before they become a problem. according to the president of nutrition society of nigeria, professor onimawu, coffee contains caffeine, a stimulant. most stimulants, he said, played the role of creating alertness in people. this could be of help to people who suffer from dementia as it helps the sufferer to be smart by creating alertness. speaking on the role of coffee in reducing blood pressure, prof. onimawu said that due to stress and other factors, many nigerians were becoming hypertensive and therefore, taking coffee could aggravate it. as for people who do not have any case of high blood pressure, coffee has no side effect at all. onimawu however, noted that tea unlike coffee contained less caffeine and more antioxidants - substances that help in the prevention of cellular damage - the common pathway for cancer, aging, and a variety of diseases. he added that although coffee also contained antioxidant in limited amount, tea was more helpful than coffee. there is 400mg of caffeine in four cups of coffee and this amount is thought to provide the maximum benefit of coffee ’ s disease - combating antioxidants. “ tea and coffee are packed with antioxidant polyphenols, which can potentially cut the risk of cancer, ’ says dr michelle harvey, research dietician at the genesis breast cancer prevention centre, university hospital of south manchester nhs foundation trust. “ studies show it promotes production of a less potent form of the cancer - causing hormone oestrogen, ” she said. university


what is working memory? working memory is the thinking skill that helps you to : - remember information and then use it later. - perform multi - step directions. - understand what you have read. for example, you use your working memory skills when you remember the rules for basketball while you ’ re in the middle of playing a game. sammy & ugene in this comic strip, sammy calls ugene to see if he wants to go to the beach. ugene gets so excited, however, that he forgets some important things when he ” s getting ready to go. what can you do? if you ever have a hard time remembering your teacher ’ s instructions, or if you often forget how to complete an assignment, then you might need some help improving your working memory skills. the good news is that we can help! here are some simple ideas that you can use to improve your working memory and stop forgetting important things : - learn to “ chunk ” by trying to remember two or more things as one item. you can often do this by repeatedly doing these activities together, so that three actions become one. for example, every morning you can brush your teeth, wash your face, and comb your hair, so that eventually these become one action that you do in front of the mirror. - repeat what you have heard, such as a new name or phone number, in your head a few times, and at the same time add a visual image or picture in your head of what you are thinking about. for example, if you meet a new person, you might say, “ sammy smith with brown eyes ” while having an image in your head about this. - leave yourself notes on a sticky pad in one or two places in your home that you always see.


" dover beach " by matthew arnold - critical appreciation arnold ' s " dover beach " presents the reader with a virtual journey through time. lamenting the transition from an age of certainty into an era of erosion of traditions - modernism - is the backbone of all four stanzas of the poem, brought together in our imagination by the nostalgic image of the sea. " misery ", " sadness " and " melancholy " reign most of the poem, yet the author chooses to conclude it with an emotional appeal for honesty : " ah, love, let us be true / to one another " - as it is the only true certainty left as the world around collapses under " struggle " and " fight ". the poet ' s attitude towards the subject of the poem is revealed through key words, which are also references to a number of themes in the poem. the most obvious one of these is " the sea " with its nostalgic nature and ability to represent time and timelessness simultaneously. " sadness ", " misery ", " melancholy ", " pain " accompany this effect and reveal the overall sense of regret and helplessness the author feels before the powers of time and inevitable change. the tone of the piece is determined by the constant presence of " melancholy " and " misery " in the poem that stretch on into the distance with a " long withdrawing roar... " the calmness of the narrative voice with which the piece is set to work ( " the sea is calm to - night. / the tide is full, the moon lies fair. " ) is essential for the descriptive nature of the first stanza. yet, later on its role is to emphasise the negativity in the tone of the poem : " but now i only hear / its melancholy... ", " into his mind the turbid ebb and flow / of human misery... " the end of the piece, however, implies that the alteration of the things around us is something inevitable. the tone changes in the last verse of the poem in the sense that it now not simply resents mutability, but is also a tone pleading with the reader to realise nothing is as stable and reliable as one perceives it, not to take the world for granted, and to stay " true / to one another ". the fundamental issues of the poem are not only obvious in its conclusion. the theme of time is being discussed in the second verse, where sophocles - an essential historic figure - is referred to. the mentioning of england


to one another ". the fundamental issues of the poem are not only obvious in its conclusion. the theme of time is being discussed in the second verse, where sophocles - an essential historic figure - is referred to. the mentioning of england and france at the beginning of the first verse can also be considered a historic reference and therefore - part of the theme of time as history is a natural subject of it. time here is represented by the image of the sea - with its vastness evoking powerful admiration. the theme of mutability follows closely because of the sea ' s unreliable nature. it is presented as something inevitable and insecure and, in its turn, leads onto the theme of humans staying true and honest to one another - this involving love for each other - as the only way to remain together, " for the world, which seems / to lie before us like a land of dreams / hath really neither joy, nor love, nor light. " the structure of the poem gives the immediate impression of being inconsistent and built upon no particular rules. there are four verses, none of which are alike, with no particular rhythm or rhyme pattern. yet its tremendous effect on the reader is wittily based upon the impression of sharing the author ' s thoughts as we read - it seems easy to identify with the subject matter just as the latter synchronise with the sea ' s waves. the verses lead onto one another by theme although they appear to be quite unconventionally structured. thus the end of the first stanza - occupied with sadness - brings on the " misery " of stanza two ; then the image of sea and insecurity of the end of the second verse invites the beginning of the following and ending verse. the unity of the poem is in this way complete and its impact on the reader stretches far beyond the lines. © denitza vlaeva


julie robotham june 30, 2012 spreading rumours... smartphones are facilitating cyber - bullying, according to an australian psychologist. photo : bloomberg the rise of smartphones has outpaced traditional wisdom on how parents should monitor teenagers ' use of technology and created a powerful new venue for cyber - bullying, according to an australian psychologist who has conducted the most detailed study yet of children ' s behaviour towards each other. sheryl hemphill, from the australian catholic university, followed 700 victorian school students from year 7 to year 9, asking them anonymously whether they had teased, threatened, spread rumours about or excluded other children either in person or using a computer or phone. she found 15 per cent of the teenagers had been involved in cyber - bullying, fewer than the 21 per cent who confessed to having bullied others in person. but there was little overlap between the groups, with only 7 per cent of students engaged both in face - to - face and cyber - bullying, professor hemphill found. she said this might be a result of ' ' anonymity and the perception that this form of bullying was less likely to be detected. cyber - bullying may also rely on different forms of power ' ' related to technology skills rather than physical dominance. it was also possible, she said, that teenagers might act impulsively online because they were remote from the distress caused by their behaviour. ' ' in cyberspace you don ' t have the visual cues, ' ' she said. many authorities, including the federal government ' s stay smart online initiative recommend parents keep computers in the family room so children ' s internet activity is visible. but smartphones had raised the stakes, professor hemphill said. ' ' there have been ideas about how much monitoring parents should do … but now with smartphones they really can ' t be there all the time. ' ' a survey by google last month showed more than half of mobile phones in australia have internet capability. in contrast to traditional bullying, professor hemphill ' s survey, published this week in the journal of adolescent health, found cyber - bullying was not linked to disrupted family background or poor school performance. she hopes to conduct further research into characteristics of individual children or situations, including whether group dynamics affect the likelihood of bullying as online devices become more prevalent. ' ' what are the peer things that are going on if they ' re all online at the same time? ' ' she asks. ' ' we know peers are really important for adolescents and if you get a group together it could be that


a big question mark stands over washington ' s efforts to deal with ocean acidification is money : how much will be needed and where it will come from? a state panel, the first of its kind in the nation, discussed a wide range of draft recommendations friday ( july 20 ) at the university of washington. gov. chris gregoire appointed the panel — a collection of scientists, shellfish industry officials, and federal and state government representatives — to recommend how washington can tackle ocean acidification along its coasts. this is the first state effort of its kind in the nation. because of the rising levels of acidity, tiny oyster shells in washington ' s dabob bay and in oregon ' s netarts bay are crumbling faster than they can grow back. a drop on the water ' s ph is being pinpointed as the culprit for endangering the northwest ' s $ 270 million shellfish industry. ph measures the acidity or alkalinity of a fluid on a 14 - point scale. the lower the number, the more acidic the liquid is. distilled water is considered " neutral " ; sea water is normally 8. 1 to 8. 2, which is on the alkaline side. orange juice ' s ph is 3 ; battery acid ' s ph is close to a one. shellfish survives in a narrow ph spectrum. at 100 feet deep, some dabob bay water has sometimes been measured at a ph of 7. 5. gregoire ' s panel is scheduled to present its fix - it recommendations to her on oct. 1. those recommendations will be general ones with plenty of details that will have to be later hashed out. that includes beginning to get a handle on the funding needs, but probably not in detail, said jay manning and bill ruckelshaus, the panel ' s chairmen. manning is gregoire ' s former chief of staff. ruckelshaus was the federal environmental protetcion agency ' s first chief in 1970 and is advisory board chairman of the william d. ruckelshaus center at the university of washington and washington state university. ( disclosure : ruckelshaus is also a member of crosscut ' s board. ) " we ' ll probably have qualitative discussions about our best guesses to the costs, " manning said. panelist peter goldmark, washington ' s commissioner of public lands, said, " we also want an analysis of what no action would cost. " the panel discussed potential remediation measures such as recycling old shells


the costs, " manning said. panelist peter goldmark, washington ' s commissioner of public lands, said, " we also want an analysis of what no action would cost. " the panel discussed potential remediation measures such as recycling old shells to provide an underwater substrate for shellfish larvae to grow in ; experimenting with algae to improve water at hatcheries ; and experimenting with eelgrass and seaweed in the field to help remove carbon dioxide from the water. to varying degrees, these measures have worked or have been studied ; more field work is needed to gather better evidence on their effectiveness. other potential measures include expanding the number of ph monitors in washington ' s waters ; studying whether certain shellfish species perform better in specific bays and inlets ; improving how water is treated as it goes into hatcheries ; and collecting water and biological data in a more long - term systematic way. also, the panel is looking at lining up government programs, agencies, and funds that can coordinate and tackle the problem. this includes examining sewage treatment plants. to limit the discharge of nutrients into the water, where they increase acidity, setting up a system of business credits for discharges has been mentioned. nutrient credits could be traded like carbon credits " we know nutrients are stressors of of the system, even though we can ' t quantify it, " said panelist ted sturdevant, director of washington ' s department of ecolgoy. another proposition before the panel is to forbid commercial and recreational vessels from discharging sewage into puget sound. some panelists wondered how far new regulations will go on fixing the overall problem ; should the carrot or stick be stressed? " regulation has not gotten us as far as we should, " said ron sims, representing the puget sound partnership on the panel. before oct. 1, the panel wants to set up ways its recommendations will be addressed by the state and federal governments, environmental groups, industry and private citizens. that includes setting up written agreements among agencies, and identifying a state entity with the coordination responsibilities. " we need an insitutional approach to make sure these recommendations are listened to, " ruckelshaus said. also, panelists said the state ' s efforts need to be coordinated with worldwide ventures on studying ocean acidity. ruckelshaus said, " it makes sense to make our results as relevant to the rest of the world as possible. " like what you just read? support high quality local journalism. become a member of crosscut today!