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The phenology of seed ripening and release are important for dispersal, reproductive success and survival of plants. Most phenological studies, however, consider early phenological phases. Here, we examined the ecological and evolutionary basis of ripening and seed release phenology. We monitored single flower phenology for 104 plant species from 30 families and three life forms from central Europe. Further, we undertook an associate monitoring study along an elevational gradient over two years. We calculated temperature demands (as growing degree days) for ripening and seed release and examined them with respect to the species’ seed mass, life form, dispersal mode and phylogeny. We found a strong correlation between species’ seed mass and temperature demands for ripening. For both variables seed mass and temperature demands for seed ripening, we found a strong effect of the species phylogeny. These phylogenetic signals indicate that the evolutionary history of the species’ lineage affects its seed mass and the temperature demands for seed ripening. Among the studied life forms, shrub species showed the most efficient ripening process. Anemochorous species showed lower relative humidity during seed release than epizoochorous species. For anemochorous species, the synchronisation of release timing with periods that show favourable environmental conditions for wind dispersal could be interpreted as a phenological adaptation to increase dispersal distances. According to the monitoring along the elevational gradient, individuals from higher altitudes showed lower temperature demands for ripening than individuals from lower altitudes. This might tentatively indicate physiological adaptations to lower temperature demands for locations with a shorter growing season. Our study provides basic insights into the ecological, environmental and evolutionary constraints that shape the ripening and seed release phenology of plants. We introduce data that can be used to advance existing models of ripening phenology, seed release and plant spread.  相似文献   

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Gaia theory, which describes the life-environment system of the Earth as stable and self-regulating, has remained at the fringes of mainstream biological science owing to its historically inadequate definition and apparent incompatibility with individual-level natural selection. The key issue is whether and why the biosphere might tend towards stability and self-regulation. We review the various ways in which these issues have been addressed by evolutionary and ecological theory, and relate these to 'Gaia theory'. We then ask how this theory extends the perspectives offered by these disciplines, and how it might be tested by novel modelling approaches and laboratory experiments using emergent technologies.  相似文献   

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The increasing threat of infectious diseases in humans has renewed interest in factors leading to the emergence of new diseases and the re-emergence of familiar diseases. Examples of seemingly novel diseases currently spreading in human populations include HIV, dengue hemorrhagic fever and Lyme disease; drug-resistant forms of well-known diseases such as tuberculosis are also increasing. The problem of disease emergence also extends to other animal and plant populations. In most current epidemics, ecological factors (e.g. migration, climate, agricultural practices) play a more significant role in disease emergence than evolutionary changes in pathogens or hosts. Evolutionary biologists and ecologists have much to offer to the development of strategies for the control of emerging diseases.  相似文献   

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The coronavirus pandemic has caused a global public health crisis with an unprecedented shutdown of major establishments and non-emergency services. Disruptions across the country in dental hospitals led to challenges in addressing patient’s dental complaints. The present study aimed to analyse the difference in the pattern of the Outpatient dental visits during the pandemic period in comparison to that of the pre-pandemic period in a tertiary care hospital. This retrospective study was carried out by retrieving the patient data from the diagnostic register of the Department of Oral Medicine and Radiology for a period of one year. The data that was retrieved from 24th September 2019 to 23rd March 2020 was categorized under the pre-pandemic period and the data from 24th March 2020 to 24th September 2020 was grouped under the pandemic period. Patient data regarding the age, gender and clinical diagnosis was recorded and categorized under three main categories: “Emergency”, “urgent” and “elective”. 7550 patients during pre-pandemic period and 4035 patients during the pandemic period visited the dental hospital during the study period. Under the “emergency dental care” category, during the pre-pandemic period, majority of the cases reported of acute dental pain (71.0%) followed by cellulitis and space infection (20.1%) and maxillofacial trauma (8.7%). During the pandemic period, acute dental pain consisted of all emergency visits (n = 307). The proportion of emergency dental visits during the pandemic were significantly higher than the pre-pandemic period. Elective dental visits were significantly higher during pre-pandemic period in comparison to the pandemic period. (P < 0.001). There was a notable change in the outpatient trend of the dental visits during the COVID-19 pandemic in comparison to the pre-pandemic period. Emergency dental services were utilized at a higher rate during the pandemic period in comparison to the pre-pandemic counterpart.  相似文献   

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PurposeWe present the implementation of e-learning in the Master of Medical Physics programme at the University of Malaya during a partial lockdown from March to June 2020 due to the COVID-19 pandemic.MethodsTeaching and Learning (T&L) activities were conducted virtually on e-learning platforms. The students' experience and feedback were evaluated after 15 weeks.ResultsWe found that while students preferred face-to-face, physical teaching, they were able to adapt to the new norm of e-learning. More than 60% of the students agreed that pre-recorded lectures and viewing videos of practical sessions, plus answering short questions, were beneficial. Certain aspects, such as hands-on practical and clinical experience, could never be replaced. The e-learning and study-from-home environment accorded a lot of flexibility. However, students also found it challenging to focus because of distractions, lack of engagement and mental stress. Technical problems, such as poor Internet connectivity and limited data plans, also compounded the problem.ConclusionWe expect e-learning to prevail in future. Hybrid learning strategies, which includes face-to-face classes and e-learning, will become common, at least in the medical physics programme of the University of Malaya even after the pandemic.  相似文献   

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Consistent individual differences in behaviour, aka personality, pose several evolutionary questions. For example, it is difficult to explain within-individual consistency in behaviour because behavioural plasticity is often advantageous. In addition, selection erodes heritable behavioural variation that is related to fitness, therefore we wish to know the mechanisms that can maintain between-individual variation in behaviour. In this paper, we argue that whole genome expression data can reveal new insights into the proximate mechanisms underlying personality, as well as its evolutionary consequences. After introducing the basics of whole genome expression analysis, we show how whole genome expression data can be used to understand whether behaviours in different contexts are affected by the same molecular mechanisms. We suggest strategies for using the power of genomics to understand what maintains behavioural variation, to study the evolution of behavioural correlations and to compare personality traits across diverse organisms.  相似文献   

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The increased application of abundance data embedded within a more detailed and precise environmental context is enabling paleontologists to explore more rigorously the dynamics and underlying processes of ecological and evolutionary change in deep time. Several recent findings are of special theoretical interest. Community membership is commonly more stable and persistent than expected by chance, even in the face of the extreme environmental changes of the Ice Ages, and major evolutionary novelties commonly lie dormant for tens of millions of years before the ecological explosions of the clades that possess them. As we discuss here, questions such as these cannot be adequately addressed without the use of the fossil record.  相似文献   

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The academic disciplines of Science, Technology, Engineering and Mathematics (STEM) have long suffered from a lack of diversity. While in recent years there has been some progress in addressing the underrepresentation of women in STEM subjects, other characteristics that have the potential to impact on equality of opportunity have received less attention. In this study, we surveyed 188 early career scientists (ECRs), defined as within 10 years of completing their PhD, in the fields of ecology, evolutionary biology, behaviour, and related disciplines. We examined associations between ethnicity, age, sexual orientation, sex, socioeconomic background, and disability, with measures of career progression, namely publication record, number of applications made before obtaining a postdoc, type of contract, and number of grant applications made. We also queried respondents on perceived barriers to progression and potential ways of overcoming them. Our key finding was that socioeconomic background and ethnicity were associated with measures of career progression. While there was no difference in the number of reported first‐authored papers on PhD completion, ethnic minority respondents reported fewer other‐authored papers. In addition, ECRs from a lower socioeconomic background were more likely to report being in teaching and research positions, rather than research‐only positions, the latter being perceived as more prestigious by some institutions. We discuss our findings in the context of possible inequality of opportunity. We hope that this study will stimulate wider discussion and help to inform strategies to address the underrepresentation of minority groups in the fields of ecology and evolution, and STEM subjects more widely.  相似文献   

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The polymerase chain reaction has been a boon to the study of molecular ecology and population genetics of birds. But the nagging truth is that for many bird species, the number of polymerase chain reaction (PCR) primer pairs that one can pick off the shelf and expect to amplify their target loci with ease is frustratingly small. Now, studying DNA sequence variation in natural populations of birds just got a whole lot easier. This issue of Molecular Ecology reports a large-scale bioinformatics search for exonic sequences conserved between the chicken and zebra finch genomes and flanking polymorphic introns that has generated a staggering 242 PCR primer pairs that readily amplify their single-copy target loci in five avian species spanning ~100 million years of avian evolution ( Backström et al . 2008 ). As proof of principle, these primers have also been used to survey the genomic landscape in over 110 kb of intronic sequence in the collared flycatcher, a model species in ecology and evolution. These resources pave the way for easy multilocus study of evolving populations and lineages of birds, and bring the goal of quickly turning nonmodel species in to ecological genomic models tantalizingly close.  相似文献   

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The COVID-19 pandemic is going into its third year with Europe again being the focus of major epidemic activity. The present review tries to answer the question whether one can come to grip with the pandemic by a combination of vaccinations and non-pharmaceutical interventions (NPIs). Several COVID-19 vaccines are of remarkable efficacy and achieve high protection rates against symptomatic disease, especially severe disease, but mathematical models suggest that the current vaccination coverage in many countries is insufficient to achieve pandemic control. NPIs are needed as complementary measures because recent research has also revealed the limits of vaccination alone. Here, we review the evidence for efficacy of face mask wearing in various settings. Overall pooled analysis showed significant reduction in COVID-19 incidence with mask wearing, although heterogeneity between studies was substantial. Controlled trials of mask wearing are difficult to conduct, separating mask wearing effects in population studies from the impact of other NPIs is challenging and the efficacy of masks depend on mask material and mask fit. The combination of vaccination and mask wearing is potentially synergistic since vaccination protects so far well from disease development (the omicron variant is currently an unknown) but immunity from infection wanes over few months after vaccination. In comparison, masks interfere with the virus transmission process at a level of a physical barrier independent of coronavirus variant. Vaccination and masks are much less costly to apply than other NPI measures which are associated with high economic and social costs, but paradoxically both measures are the target of a vocal opposition by a sizable minority of the society. In parallel with biomedical research, we need more social science research into this opposition to guide political decisions on how to end the pandemic.  相似文献   

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The need for open, reproducible science is of growing concern in the twenty-first century, with multiple initiatives like the widely supported FAIR principles advocating for data to be Findable, Accessible, Interoperable and Reusable. Plant ecological and evolutionary studies are not exempt from the need to ensure that the data upon which their findings are based are accessible and allow for replication in accordance with the FAIR principles. However, it is common that the collection and curation of herbarium specimens, a foundational aspect of studies involving plants, is neglected by authors. Without publicly available specimens, huge numbers of studies that rely on the field identification of plants are fundamentally not reproducible. We argue that the collection and public availability of herbarium specimens is not only good botanical practice but is also fundamental in ensuring that plant ecological and evolutionary studies are replicable, and thus scientifically sound. Data repositories that adhere to the FAIR principles must make sure that the original data are traceable to and re-examinable at their empirical source. In order to secure replicability, and adherence to the FAIR principles, substantial changes need to be brought about to restore the practice of collecting and curating specimens, to educate students of their importance, and to properly fund the herbaria which house them.  相似文献   

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Immunopathology (immune-mediated pathology) is a ubiquitous cause of disease during infection, but how will parasite exploitation strategies evolve in its presence? Immunopathology can act to increase parasite fitness if it increases transmission rate, but can equally act to decrease parasite fitness if it increases host mortality. The focus here is on understanding how immunopathology, mediated through different immune mechanisms, can influence parasite fitness and how experimental manipulations of the immune system can be carried out to examine this. A better understanding of how parasite fitness scales with, or responds to, immunopathology is crucial to understanding the nature of selection acting on parasite virulence traits and will allow more informed predictions to be made regarding the trajectory of parasite virulence evolution.  相似文献   

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Movement is central to the survival of all free‐living organisms. Consequently, movement and what anthropologists often refer to as mobility, which is the sum of small‐scale movements tracked across larger geographic and temporal scales, are key targets of selection. Movement and mobility also underpin many of the key features that make us human and that allowed our lineage to adapt to changing environments across the globe. The most obvious example is the evolution of humans' singular mode of locomotion. Bipedalism is arguably the most important derived anatomical trait of the hominin lineage. The mechanisms and circumstances that gave rise to this novel mode of movement remain subjects of intense research.  相似文献   

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In the absence of valid medicine or vaccine for treating the pandemic Coronavirus (COVID-19) infection, other control strategies like; quarantine, social distancing, self- isolation, sanitation and use of personal protective equipment are effective tool used to prevent and curtail the spread of the disease. In this paper, we present a mathematical model to study the dynamics of COVID-19. We then formulate an optimal control problem with the aim to study the most effective control strategies to prevent the proliferation of the disease. The existence of an optimal control function is established and the Pontryagin maximum principle is applied for the characterization of the controller. The equilibrium solutions (DFE & endemic) are found to be locally asymptotically stable and subsequently the basic reproduction number is obtained. Numerical simulations are carried out to support the analytic results and to explicitly show the significance of the control. It is shown that Quarantine/isolating those infected with the disease is the best control measure at the moment.  相似文献   

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