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1.
Biodiversity experiments show that increases in plant diversity can lead to greater biomass production, and some researchers suggest that high diversity plantings should be used for bioenergy production. However, many methods used in past biodiversity experiments are impractical for bioenergy plantings. For example, biodiversity experiments often use intensive management such as hand weeding to maintain low diversity plantings and exclude unplanted species, but this would not be done for bioenergy plantings. Also, biodiversity experiments generally use high seeding densities that would be too expensive for bioenergy plantings. Here we report the effects of biodiversity on biomass production from two studies of more realistic bioenergy crop plantings in southern Michigan, USA. One study involved comparing production between switchgrass (Panicum virgatum) monocultures and species-rich prairie plantings on private farm fields that were managed similarly to bioenergy plantings. The other study was an experiment where switchgrass was planted in monoculture and in combination with increasingly species-rich native prairie mixtures. Overall, we found that bioenergy plantings with higher species richness did not produce more biomass than switchgrass monocultures. The lack of a positive relationship between planted species richness and production in our studies may be due to several factors. Non-planted species (weeds) were not removed from our studies and these non-planted species may have competed with planted species and also prevented realized species richness from equaling planted species richness. Also, we found that low seeding density of individual species limited the biomass production of these individual species. Production in future bioenergy plantings with high species richness may be increased by using a high density of inexpensive seed from switchgrass and other highly productive species, and future efforts to translate the results of biodiversity experiments to bioenergy plantings should consider the role of seeding density.  相似文献   

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Temperature-related words such as cold-blooded and hot-headed can be used to describe criminal behavior. Words associated with coldness describe premeditated behavior and words associated with heat describe impulsive behavior. Building on recent research about the close interplay between physical and interpersonal coldness and warmth, we examined in a lab experiment how ambient temperature within a comfort zone influences judgments of criminals. Participants in rooms with low temperature regarded criminals to be more cold-blooded than participants in rooms with high temperature. Specifically, they were more likely to attribute premeditated crimes, ascribed crimes resulting in higher degrees of penalty, and attributed more murders to criminals. Likewise, participants in rooms with high temperature regarded criminals to be more hot-headed than participants in rooms with low temperature: They were more likely to attribute impulsive crimes. Results imply that cognitive representations of temperature are closely related to representations of criminal behavior and attributions of intent.  相似文献   

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Species distribution models (SDMs) are commonly used to project future changes in the geographic ranges of species, to estimate extinction rates and to plan biodiversity conservation. However, these models can produce a range of results depending on how they are parameterized, and over‐reliance on a single model may lead to overconfidence in maps of future distributions. The choice of predictor variable can have a greater influence on projected future habitat than the range of climate models used. We demonstrate this in the case of the Ptunarra Brown Butterfly, a species listed as vulnerable in Tasmania, Australia. We use the Maxent model to develop future projections for this species based on three variable sets; all 35 commonly used so‐called ‘bioclimatic’ variables, a subset of these based on expert knowledge, and a set of monthly climate variables relevant to the species’ primary activity period. We used a dynamically downscaled regional climate model based on three global climate models. Depending on the choice of variable set, the species is projected either to experience very little contraction of habitat or to come close to extinction by the end of the century due to lack of suitable climate. The different conclusions could have important consequences for conservation planning and management, including the perceived viability of habitat restoration. The output of SDMs should therefore be used to define the range of possible trajectories a species may be on, and ongoing monitoring used to inform management as changes occur.  相似文献   

4.
Levitin DJ 《Neuron》2012,73(4):633-637
Music can be seen as a model system for understanding gene × environment interactions and how these can influence neurocognitive development. The concept of musicality, however, is underspecified and not well understood. Here, I propose a framework for defining musicality to provide a foundation for studying the contributions of biological and environmental factors.  相似文献   

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Background

Discriminating threatening individuals from non-threatening ones allow territory owners to modulate their territorial responses according to the threat posed by each intruder. This ability reduces costs associated with territorial defence. Reduced aggression towards familiar adjacent neighbours, termed the dear-enemy effect, has been shown in numerous species. An important question that has never been investigated is whether territory owners perceive distant neighbours established in the same group as strangers because of their unfamiliarity, or as dear-enemies because of their group membership.

Methodology/Principal Findings

To investigate this question, we played back to male skylarks (Alauda arvensis) songs of adjacent neighbours, distant neighbours established a few territories away in the same microdialect area and strangers. Additionally, we carried out a propagation experiment to investigate how far skylark songs are propagated in their natural habitat and we estimated repertoire similarity between adjacent neighbours, distant neighbours and strangers. We show that skylarks, in the field, respond less aggressively to songs of their distant and likely unfamiliar neighbours, as shown by the propagation experiment, compared to stranger songs. The song analysis revealed that individuals share a high amount of syllables and sequences with both their adjacent and distant neighbours, but only few syllables and no sequences with strangers.

Conclusions

The observed reduction of aggression between distant neighbours thus probably results from their familiarity with the vocal group signature shared by all members of the neighbourhood. Therefore, in skylarks, dear-enemy-like relationships can be established between unfamiliar individuals who share a common acoustic code.  相似文献   

7.
The extensive use of nanometal-based products increases the chance of their release into aquatic environments, raising the question whether they can pose a risk to aquatic biota and the associated ecological processes. Aquatic microbes, namely fungi and bacteria, play a key role in forested streams by decomposing plant litter from terrestrial vegetation. Here, we investigated the effects of nanocopper oxide and nanosilver on leaf litter decomposition by aquatic microbes, and the results were compared with the impacts of their ionic precursors. Alder leaves were immersed in a stream of Northwest Portugal to allow microbial colonization before being exposed in microcosms to increased nominal concentrations of nanometals (CuO, 100, 200 and 500 ppm; Ag, 100 and 300 ppm) and ionic metals (Cu2+ in CuCl2, 10, 20 and 30 ppm; Ag+ in AgNO3, 5 and 20 ppm) for 21 days. Results showed that rates of leaf decomposition decreased with exposure to nano- and ionic metals. Nano- and ionic metals inhibited bacterial biomass (from 68.6% to 96.5% of control) more than fungal biomass (from 28.5% to 82.9% of control). The exposure to increased concentrations of nano- and ionic metals decreased fungal sporulation rates from 91.0% to 99.4%. These effects were accompanied by shifts in the structure of fungal and bacterial communities based on DNA fingerprints and fungal spore morphology. The impacts of metal nanoparticles on leaf decomposition by aquatic microbes were less pronounced compared to their ionic forms, despite metal ions were applied at one order of magnitude lower concentrations. Overall, results indicate that the increased release of nanometals to the environment may affect aquatic microbial communities with impacts on organic matter decomposition in streams.  相似文献   

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BackgroundPeople encounter various moral issues that involve making decisions for others by giving advice.ObjectiveThis study investigated the characteristics of providing suggestions for oneself versus providing suggestions for others in ethical decision-making and the differences between them based on Construal Level Theory (CLT).MethodsA total of 768 undergraduate students from three universities in China were randomly assigned to eight groups on the basis of a grid of two Construal Levels (self or others) by two different numbers of people saved (5 people or 15 people) by two problem situations (trolley problem vs. footbridge problem). The investigation examined participants’ decisions to opt to take action or refrain from action that would have the consequence of saving more people.ResultsThe main effects of Construal Level (F1, 752 = 6.46, p = .011), saving number (F1, 752 = 35.81, p < .001), and problem situation type (F1, 752 = 330.55, p < .001) were all significant. The interaction of the problem situation and saving number (F1, 752 = 1.01, p = .31), and social distance and saving number (F1, 752 = 0.85, p = .36), and interaction of the three independent factors (F1, 752 = 0.47, p = .49) were not significant. However, the interaction of social distance and problem situation (F1, 752 = 9.46, p = .002) was significant. Results indicated the participants utilized a component of utilitarian reasoning in the decision-making, and their behaviors appeared more utilitarian at low Construal Levels (CLs) compared to high.ConclusionCLs, saving numbers, and problem situation significantly affected moral decision-making and exhibited significant interaction. Making decisions for oneself (low-construal) rather than giving advice to others (high-construal) was one important factor that determined whether the people were utilitarian or not. Utilitarian considerations are more relevant in impersonal dilemmas.  相似文献   

10.
A great majority of genetic markers discovered in recent genome-wide association studies have small effect sizes, and they explain only a small fraction of the genetic contribution to the diseases. How many more variants can we expect to discover and what study sizes are needed? We derive the connection between the cumulative risk of the SNP variants to the latent genetic risk model and heritability of the disease. We determine the sample size required for case-control studies in order to achieve a certain expected number of discoveries in a collection of most significant SNPs. Assuming similar allele frequencies and effect sizes of the currently validated SNPs, complex phenotypes such as type-2 diabetes would need approximately 800 variants to explain its 40% heritability. Much smaller numbers of variants are needed if we assume rare-variants but higher penetrance models. We estimate that up to 50,000 cases and an equal number of controls are needed to discover 800 common low-penetrant variants among the top 5000 SNPs. Under common and rare low-penetrance models, the very large studies required to discover the numerous variants are probably at the limit of practical feasibility. Under rare-variant with medium- to high-penetrance models (odds-ratios between 1.6 and 4.0), studies comparable in size to many existing studies are adequate provided the genotyping technology can interrogate more and rarer variants.  相似文献   

11.
During the past two decades, Mediterranean waters have been warming at a rather high rate resulting in scientific and social concern. This warming trend is observed in satellite data, field data and model simulations, and affects both surface and deep waters throughout the Mediterranean basin. However, the warming rate is regionally different and seems to change with time, which has led to the question of what causes underlie the observed trends. Here, we analyze available satellite information on sea surface temperature (SST) from the last 25 years using spectral techniques and find that more than half of the warming tendency during this period is due to a non-linear, wave-like tendency. Using a state of the art hydrodynamic model, we perform a hindcast simulation and obtain the simulated SST evolution of the Mediterranean basin for the last 52 years. These SST results show a clear sinusoidal tendency that follows the Atlantic Multidecadal Oscillation (AMO) during the simulation period. Our results reveal that 58% of recent warming in Mediterranean waters could be attributed to this AMO-like oscillation, being anthropogenic-induced climate change only responsible for 42% of total trend. The observed acceleration of water warming during the 1990s therefore appears to be caused by a superimposition of anthropogenic-induced warming with the positive phase of the AMO, while the recent slowdown of this tendency is likely due to a shift in the AMO phase. It has been proposed that this change in the AMO phase will mask the effect of global warming in the forthcoming decades, and our results indicate that the same could also be applicable to the Mediterranean Sea. Henceforth, natural multidecadal temperature oscillations should be taken into account to avoid underestimation of the anthropogenic-induced warming of the Mediterranean basin in the future.  相似文献   

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Interest in filariasis has found a new impetus now that neglected tropical diseases have their own journal. However, some of the advances published in renowned international journals have completely ignored previous publications on the subject, particularly those in languages other than English. The rapid assessment procedure for loiasis and the mapping of lymphatic filariasis provide two perfect illustrations of this. This problem may seem a bit outdated, given that all “good authors” now publish exclusively in English. It certainly is outdated for most areas of medicine. But, surely, this should not be the case for neglected tropical diseases, for which certain long-standing findings are every bit as important as what may be presented as new discoveries. One possibility would be for certain journals, such as PLOS Neglected Tropical Diseases, to include a specific heading permitting the publication in English of older studies that initially appeared in a language other than English. The texts would be English versions respecting the entirety of the original text. Submission should be accompanied by a presentation of the problem, with details and explanatory comments, with submission at the initiative of the authors of the former article in question or their students or sympathizers.Interest in filariasis has found a new impetus now that neglected tropical diseases (NTDs) have their own journal. However, some of the advances published in renowned international journals have completely ignored previous publications on the subject, particularly those in languages other than English. This Viewpoint article is intended to make us ponder the issue of a language gap or discrimination existing in publishing outcomes and reference citations. This is also the question of deleterious effects of the obligation “to be in English or not to be”.The rapid assessment procedure for loiasis (RAPLOA) and the geographical distribution of lymphatic filariasis provide two perfect illustrations of this.The RAPLOA has recently been widely used to determine the regional endemicity of loiasis and to update existing endemicity data for this disease over its global distribution range. This important work has been recently published in PLOS NTDs [1]. The determination, within a population of the prevalence or, preferably, the annual incidence of episodes, of conjunctival migration by adult worms is a simple, non-invasive, relatively sensitive and specific method for evaluating the endemicity of Loa loa. This approach has proved particularly useful in areas in which both loiasis and onchocerciasis are observed: the mass treatment program to control onchocerciasis is based on the use of ivermectin and there is a risk of adverse treatment outcomes in patients carrying large numbers of L. loa worms [2]. In regions of high endemicity, the correlation between the conjunctival migration index and the microfilarial index is strong overall, both for villages and for age groups. Its use as an epidemiological index was clearly proposed in a publication in 1994 [3]. However, as this article was published in French, in Médecine Tropicale (Marseille), it has never been cited, despite being listed in international databases, including PubMed. A poster communication concerning the same issue had no real impact either, despite being presented at an international congress [4]. The origin of this new epidemiological index (RAPLOA) is systematically attributed to two World Health Organization (WHO) publications in 2001 [5] and 2002 [6]. It is true that the studies reported in these publications validated the concept at a large scale and in different endemic foci.The usefulness of specific clinical manifestations (eye worm and Calabar swelling) to assess L. loa had been recommended by different authors as early as 1950 [7]. But the correlation between the microfilarial index and the frequency of ocular migration has not been studied, and even less attention was paid to the notion of an epidemiological index until the epidemiological studies carried out in Congo Republic (former People''s Republic of the Congo) during the 1980s [8]. However, the index as such was clearly defined in 1994 [3]. Here is a direct translation of an excerpt of the French text published in 1994: “For loiasis, the usual parasitological indices (microfilarial index and mean microfilarial density) are the only measures recognized as providing information about the level of endemicity in humans. In addition to requiring blood samples standardized in terms of both volume and sampling time, these indices do not reflect the real level of parasitism, given the high frequency of infected subjects without microfilaria in the blood. Subjects infested with mature, fertile adult worms, as demonstrated by the removal of a subconjunctival female containing microfilaria from a patient with no detectable microfilaria in the blood, are frequently observed. Two symptoms are both specific and frequent in infected subjects both with and without microfilaria in the blood: subconjunctival migration of an adult worm and elusive, migrating edemas of the hands, wrists and lower part of the forearm” [9]. “The index of subconjunctival filarial migration over the preceding year is particularly useful, because it correlates well with the microfilarial index but is more sensitive” (Figure 1). “Its determination involves precise questioning of the patient, which can be facilitated by the use of a demonstration chart, with diagrams and photographs” (see Figure 2).Open in a separate windowFigure 1Index of the subconjunctival migration of Loa loa adult worms and microfilarial index.Reproduced from Medicine Tropicale [3], released under CC BY 2.0 by Medicine Tropicale. IMSC = Indice de Migration Sous-Conjonctivale in French and Index of the SubConjunctival Migration in English. IM = Indice Microfilarien in French and Microfilarial Index in English.Open in a separate windowFigure 2Illustration of the passage of an adult worm (Loa loa) across the eye.This illustration (diagram and photograph) was made for presentation to patients questioned in endemic regions.The conclusion of this article was formulated as follows: “Screening for foci of filarial endemicity could be improved by the use of a simplified method and the validation of simple, inexpensive indices. Once these foci have been identified, a more precise evaluation can be carried out.”What is most astounding about the two WHO publications cited as the origin of this “new epidemiological index” [5], [6] is that the principal authors come from French-speaking African countries and/or work in or with this institution. They would therefore have been able to understand articles written in French. Furthermore, the WHO has a long-standing culture of multilingualism, particularly in English and French.Against this background, the rejection by the Bulletin of the World Health Organization and by other international journals published in English of an opinion article dealing with this issue and using the example of lymphatic filariasis does not seem to be justified, and is another illustration of “to be in English or not to be.”Indeed, filariasis due to Wuchereria bancrofti is systematically described as endemic in Congo and Gabon, two French-speaking countries, in non-specialist works on tropical medicine and in more specialist publications (WHO) despite a total absence of epidemiologic studies and/or confirmed case report over the last 30 years to prove it. What is certain is that no case was found when the last studies were conducted in these countries at the end of the 1970s and during the 1980s but unfortunately published in French. The studies that we carried out in the Congo as part of the National Project on Onchocerciasis and Other Filariases (between 1982 and 1987) confirmed the presence of four types of human filariasis: onchocerciasis, loaiasis, and the filariases caused by Mansonella perstans and M. streptocerca. There was a total absence of confirmed cases of lymphatic filariasis (bancroftosis). In this case, it is not a question of the attribution of merit for a particular “discovery”, but of basic knowledge of the geographic distribution of a scarcely studied disease, lymphatic filiariasis, in French Central Africa. Taking into account only publications in English, even older and poorly structured data, have been, in our opinion, a source of confusion and has led to false conclusions being drawn about the distribution range of this disease. This undoubtedly highlights the need to update knowledge by carrying out prospective studies (which seem to be underway), but these studies do not seem to be considered a matter of priority given the low levels of resources available and current health priorities.This has drawn us to publish this article in a French-language journal, but together with an entire translation into English [10]. Despite the bilingual nature of this publication, the international PubMed database identifies this article as being published in French, effectively ensuring that it will never be consulted, a classic “catch 22” situation! Indeed, this reference has never yet been cited by another author in a journal published in English. It may be that publication of an article in another language than English makes it more likely that it will not be cited, even if the authors of a subsequent article have access to the journal in which it was published and can understand the language used. Here, we begin to encroach on ethical problems and it is probably best not to delve too deeply. However, suffice it to say that the limited dissemination of publications in a language other than English may account for such equivocal attitudes.The problem is not a rivalry between French and English, but the confrontation between English and all other languages of the world. Moreover, the problem is undoubtedly worse for works published in non–Western European languages such as Chinese, Russian, and Japanese, which are arguably even less accessible.All things considered, this problem may seem a bit outdated, given that all “good authors” now publish exclusively in English. It certainly is outdated for most areas of medicine, where everything that is old is assigned to being nothing more than the history of medicine. But, surely, this should not be the case for NTDs, for which certain long-standing findings are every bit as important as what may be presented as new discoveries.One possibility would be for certain journals, such as PLOS NTDs, to include a specific heading permitting the publication of older studies that initially appeared in a language other than English (and are therefore currently little known). The texts included in this heading would essentially be English versions of these articles previously published in other languages, respecting the entirety of the original text.This would concern studies considered of importance because they highlight a point that remains unclear or describe an aspect considered innovative in a review but for which the originality of the article is due more to an incomplete reference list than to a true advance in knowledge. These articles should be judged in light of the knowledge and technical and methodological means available at the time at which they were initially published. Submission should be accompanied by a presentation of the problem, with details and explanatory comments, with submission at the initiative of the authors of the article in question or their students or sympathizers.  相似文献   

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Abstract Nocodazole, a temporary inhibitor of microtubule formation, has been used to partly synchronize Ehrlich ascites tumour cells growing in suspension. the gradual entry of cells into mitosis and into the next cell cycle without division during drug treatment has been studied by flow cytometric determination of mitotic cells, analysing red and green fluorescence after low pH treatment and acridine orange staining. Determination of the mitotic index (MI) by this method has been combined with DNA distribution analysis to measure cell-cycle phase durations in asynchronous populations growing in the presence of the drug. With synchronized cells, it was shown that in the concentration range 0.4–4.0 μg/l, cells could only be arrested in mitosis for about 7 hr and at 0.04 μg/ml, for about 5 hr. After these time intervals, the DNA content in nocodazole-blocked cells was found to be increased, and, in parallel, the ratio of red and green fluorescence was found to have changed, showing entry of cells into a next cell cycle without division (polyploidization). It was therefore only possible to partially synchronize an asynchronous population by nocodazole. However, a presynchronized population, e.g. selected G1 cells or metabolically blocked G1/S cells, were readily and without harmful effect resynchronized in M phase by a short treatment (0.4 μg/ml, 3–4 hr) with nocodazole; after removal of the drug, cells divided and progressed in a highly synchronized fashion through the next cell cycle.  相似文献   

17.

Objective

As large-scale genome sequencing technology advances, concerns surrounding the reporting of individual findings to study volunteers have grown and fueled controversy. This is especially true in mental health research, where the clinical importance of sequencing results is particularly unclear. The ethical, legal, and social issues are being widely debated, but less is known about the attitudes of actual study volunteers toward sequencing studies or what they wish to learn about their DNA sequence and its health implications. This study provides information on psychiatric research volunteers’ attitudes, beliefs, and concerns with respect to participation in DNA sequencing studies and reporting of individual results.

Method

We conducted a pilot study using a questionnaire that we developed to assess what information volunteers in an ongoing family study of bipolar disorder would like to receive if they underwent genome sequencing, what they would do with that information, and what concerns they may have.

Results

Almost all of the respondents were willing to participate in genome sequencing. Most respondents wished to be informed about all their health-related genetic risks, including risks for diseases without known prevention or treatment. However, few respondents felt well informed about the nature of genome sequencing or its implications for their health, insurability, or offspring.

Conclusions

Despite generally positive attitudes toward genome sequencing among study volunteers, most are not fully aware of the special issues raised by genome sequencing. The attitudes of study volunteers should be considered in the debate about the reporting of individual findings from genome sequencing.  相似文献   

18.
This review focuses on the possible association between types of fatty acids and weight change. It examines the biological plausibility underlining these associations and the evidence obtained to date from clinical trials and epidemiological studies. Animal studies have shown that dietary short- and medium-chain fatty acids compared to long-chain fatty acids appear to promote weight loss. Similarly, monounsaturated fatty acids (MUFAs) appear to favor weight loss compared to saturated fatty acids (SFAs) in human studies. The structure of fatty acids seems to affect their degree of oxidation and deposition. Although results are conflicting, human studies follow the general trend reported in animal studies. These trials suggest that some fatty acids are prone to oxidation and some others lead to fat storage when comparing isocaloric diets. For instance, n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic and docosahexaenoic acids are preferentially oxidizied to other PUFA but results remain inconsistent. Epidemiological studies concerning this issue reported that total dietary fat, which includes MUFA, PUFA, and SFA could increase the risk of obesity, but results are few and conflicting. The rising biological plausibility linking dietary fat quality and risk of obesity, together with the rather recent addition of fatty acids content in food composition tables, support the need for major epidemiological studies in that area.  相似文献   

19.
Fourteen cases of infectious polyneuritis of a kind not previously reported in this country were observed in Los Angeles—three of them in hospital personnel. The clinical features at onset were headache, fever, dizziness of peculiar order, weakness and aching muscles. Motor weakness then developed, more severe in the proximal muscle groups and more often in the lower extremity. Sensory changes were also present. In two cases, debility was so severe as to necessitate prolonged inactivity. The condition was observed in 13 females (one a child) and one man. The age range was 10 to 65 years.Similarity of this illness to one reported in England in 1954 was noted.Treatment included administration of multiple vitamins, B12 and thiamine chloride. Recovery occurred in from one week to over ten months.  相似文献   

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