Eukaryotic plankton communities across reef environments in Bocas del Toro Archipelago,Panamá

Variation in light and temperature can influence the genetic diversity and structure of marine plankton communities. While open-ocean plankton communities receive much scientific attention, little is known about how environmental variation affects plankton communities on tropical coral reefs. Here, we characterize eukaryotic plankton communities on coral reefs across the Bocas del Toro Archipelago, Panamá. Temperature loggers were deployed, and midday light levels were measured to quantify environmental differences across reefs at four inshore and four offshore sites (Inshore = Punta Donato, Smithsonian Tropical Research Institute (STRI) Point, Cristobal, Punta Laurel and Offshore = Drago Mar, Bastimentos North, Bastimentos South, and Cayo de Agua). Triplicate vertical plankton tows were collected midday, and high-throughput 18S ribosomal DNA metabarcoding was leveraged to investigate the relationship between eukaryotic plankton community structure and inshore/offshore reef environments. Plankton communities from STRI Point were additionally characterized in the morning (~ 08:00), midday (~ 12:00), and late-day (~ 16:00) to quantify temporal variation within a single site. We found that inshore reefs experienced higher average seawater temperatures, while offshore sites offered higher light levels, presumably associated with reduced water turbidity on reefs further from shore. These significant environmental differences between inshore and offshore reefs corresponded with overall plankton community differences. We also found that temporal variation played a structuring role within these plankton communities, and conclude that time of community sampling is an important consideration for future studies. Follow-up studies focusing on more intensive sampling efforts across space and time, coupled with techniques that can detect more subtle genetic differences between and within communities will more fully capture plankton dynamics in this region and beyond.

     

Cuckoo–hawk mimicry? An experimental test

The similarity between many Old World parasitic cuckoos (Cuculinae) and Accipiter hawks, in size, shape and plumage, has been noted since ancient times. In particular, hawk-like underpart barring is more prevalent in parasitic than in non-parasitic cuckoos. Cuckoo-hawk resemblance may reflect convergent evolution of cryptic plumage that reduces detection by hosts and prey, or evolved mimicry of hawks by parasitic cuckoos, either for protection against hawk attacks or to facilitate brood parasitism by influencing host behaviour. Here, we provide the first evidence that some small birds respond to common cuckoos Cuculus canorus as if they were sparrowhawks Accipiter nisus. Great tits and blue tits were equally alarmed and reduced attendance at feeders during and after the presentation of mounted specimens of common cuckoos and sparrowhawks, but not in response to control presentations of collared doves or teal. Plumage manipulations revealed that the strong alarm response to cuckoos depended on their resemblance to hawks; cuckoos with barred underparts were treated like hawks, while those with unbarred underparts were treated like doves. However, barring was not the only feature inducing alarm because tits showed similarly strong alarm to barred and unbarred hawks, and little alarm to barred doves. These responses of tits, unsuitable as hosts and hence with no history of cuckoo parasitism, suggest that naive small birds can mistake cuckoos for hawks. Thus, any cuckoo-hawk discrimination by host species is likely to be an evolved response to brood parasitism.     

Batesian, quasi-Batesian or Müllerian mimicry? Theory and data in mimicry Research

In this paper I argue that the nature of mimetic relationships remains contentious because there are insufficient data to enable full evaluation of theoretical models. There is, however, a growing appreciation of the need to draw together empirical studies to provide foundations for theoretical work. I review some recent data that considers the responses of predators to changing numbers of defended prey items and the nature of mimicry along a palatability spectrum. A simple model of predator behaviour is constructed which combines assumptions from Pavlovian learning studies with traditional ‘number dependent’ learning models. This model has two important properties. First it shows that Pavlovian assumptions can be represented in a simple model which generates interesting predictions. Second it indicates some areas that still need detailed empirical study – most importantly perhaps is the way that predators respond to prey with different levels of edibility. This revised version was published online in July 2006 with corrections to the Cover Date.     

Modifiers of the temperature–mortality association in Shanghai, China

Various factors can modify the health effects of temperature. Prior findings about modifiers are inconsistent, and such studies have been conducted mostly in developed countries. We conducted a time-series analysis to examine the modifying effect of gender, age and education on the association between temperature and daily mortality in Shanghai, China, using 4 years (2001–2004) of daily data. A natural spline model was used to analyze the data. Elderly subjects were found to be more vulnerable to temperature health effects compared with younger people. We observed no significant modifying effect of gender or education level. These findings may provide useful information for local governments seeking to take steps to protect vulnerable sub-populations.     

An epidemic of depression or the medicalization of distress?

The syndrome of major depression is widely regarded as a specific mental illness that has increased to the point where it will be second in the International Burden of Disease ranking by 2020. This article examines the assumption that major depression is a specific illness, that it is rapidly increasing, and that a medical response is justified. I argue that major depression is not a natural entity and does not identify a homogenous group of patients. The apparent increase in major depression results from: confusing those who are ill with those who share their symptoms; the surveying of symptoms out of context; the benefits that accrue from such a diagnosis to drug companies, researchers, and clinicians; and changing social constructions around sadness and distress. Standardized medical treatment of all these individuals is neither possible nor desirable. The major depression category should be replaced by a clinical staging strategy that acknowledges the continuous distribution of depressive symptoms. Trials that test social and lifestyle treatments as well as drugs and cognitive behavioral therapy across different levels of severity, chronicity, and symptom patterns might lead to the development of a coherent evidence-based stepped treatment model.     

Calculating males? An empirical and theoretical examination of the duration of paternal care in burying beetles

Summary Male and female burying beetles (Nicrophorus orbicollis) bury and preserve small carcasses which become food for their young. Typically, females remain with the brood until after larval development is complete, but males leave about 3 days after larvae hatch. In the absence of competitors, the effect of male presence throughout larval development is to reduce the size and weight of the brood on small carcasses, but not on larger ones. However, male assistance greatly reduces the probability that a conspecific competitor will usurp the carcass and kill the brood. A dynamic optimization model of the duration of paternal care is developed and the daily probabilities of discovery by conspecific competitors and of finding a new reproductive opportunity are varied. The model predicts that the duration of care should not be very sensitive to either the intensity of competition or the probability of finding another carcass. For a given probability of discovery by an intruder, the probability of finding a new carcass affects the duration of care in a stepwise fashion such that males should either provide no care or remain 10 days on large carcasses and 9 days on small ones (3 days after larvae hatch, in each case). The model also suggests that by providing an average of 9.5 days of care in nature, males act as if there is a negligible chance of having another brood, i.e. they are maximizing their reproductive success with their current brood.     

An empirical analysis of mtSSRs: could microsatellite distribution patterns explain the evolution of mitogenomes in plants?

Functional & Integrative Genomics - Microsatellites (SSRs) are tandem repeat sequences in eukaryote genomes, including plant cytoplasmic genomes. The mitochondrial genome (mtDNA) has been shown...     

An evaluation of educators’ views on the e-Bug resources in England

Introduction: e-Bug is an international educational resource for young people covering microbes, hygiene and antibiotics. e-Bug supports NICE guidance on changing public behaviour around antibiotic use. This study aimed to determine educators’ views of the e-Bug teacher resources to inform further development and dissemination of e-Bug. Methods: Age appropriate e-Bug resource packs were posted to every primary school (N = 19,142) and secondary school (N = 5637) in England with a cover letter signed by the Chief Medical Officer, Chief Executive of PHE and e-Bug Project Lead inviting educators to complete an online survey to evaluate the e-Bug resources. The online survey consisted of nine questions and took approximately 15 min to complete. Results: 695 participants completed the online survey. 94% of participants rated the e-Bug resource as excellent or good; one fifth of respondents used the e-Bug resources at least termly. Educators who used e-Bug rated the different lesson plans as excellent or good including ‘Introduction to Microbes’ (98%) and ‘Hand Hygiene’ (95%). Educators provided suggestions for the development of additional lessons plans. Conclusions: Educators view e-Bug as a valuable resource for teaching children about hygiene and antibiotics. Further e-Bug promotion and resource development is required to increase awareness and usage in schools.     

Sex-related,growth–climate association of Araucaria angustifolia in the neotropical ombrophilous woodlands of Argentina

Araucaria angustifolia is a dioecious dominant tree in araucaria forests in Brazil and Argentina, South America. The species is nowadays critically endangered by deforestation and global climate change. The goal of this study was to analyse the dynamics of radial growth in this species and its association with climatic variables, according to the sex, at its western range boundary in Argentina. Standard dendrochronological techniques were applied on stem disks from female and male trees. Xylem anatomical anomalies made the tree-ring dating process difficult. Female and male trees showed growth patterns that changed over time, not being significant in the 1950–1990 period and highly significant from the 1990s onwards (p < 0.1) when female trees had a higher growth rate. Female and male trees showed a different association with climatic variables. No significant effect of temperature and precipitation was identified on female trees. For male trees, rainfall had a positive effect in August, before the growing season, and a negative effect at the end of the growing season (March). Temperature had a negative effect on male trees, before and during the growing season (February and January, respectively). No effect of SOI was detected on both sexes. Results emphasised the usefulness of A. angustifolia for dendrochronological studies and the value of dioecious species for the study of sex-related growth–climate association.     

Fig choice by the pollinator of a gynodioecious fig: selection to rush,or intersexual mimicry?

Due to selection to maximise the benefits accrued, conflicts of interest exist between mutualists. An extreme conflict occurs between gynodioecious fig trees and their pollinating wasps. Female wasps, which are required for pollination, cannot reproduce in female figs and should be selected to avoid them. We investigate fig choice in Liporrhopalum tentacularis , pollinator of Ficus montana . We show that entry rates are independent of fig sex and diameter, with wasps instead entering the first fig encountered (although significant between-tree differences in entry rates to figs were observed). This suggests that wasps are unable to discriminate between the sexes because of selection for inter-sexual fig mimicry. In conjuction with data on other species pairs, these findings imply that that the resolution of the conflict is ultimately under the tree's control, with the level of mimicry evolving in response to both the propensity of wasps to discriminate and the costs of them doing so.     

An evaluation of restoration practises in lowland streams: Has the physical integrity been re-created?

Intensive land use by humans has led to severe degradation of streams and rivers, especially in highly industrialised countries and in lowland agricultural areas. Restorations have been conducted with the aim to improve hydromorphological conditions in modified streams. However, success has often been limited, partly because the restorations have been conducted without due regard to river-type-specific characteristics. The aim of this study was to evaluate restorations of Danish lowland streams by applying a type-specific approach. We compared the physical condition of restored streams with that of near-natural streams (least disturbed condition) and channelized streams. We stratified the data according to different stream types and included also reference sites from a less impacted country (Lithuania) in the evaluation. Our results revealed that restorations have created physical conditions that do not resemble river-type-specific LDCs, primarily due to the addition of large amounts of coarse substrate. This may have implications for the ecological communities and for biodiversity and consequently for the implementation of the Water Framework Directive in restored lowland streams. We also found that observations of physical condition in nearby reference streams may be used to advantage in future restoration planning, thereby assuring a higher degree of physical integrity in restored streams.     

An emergy evaluation of the sustainability of Chinese crop production system during 2000–2010

Crop production systems are the basis of human survival and development because they can produce grain and industrial raw materials. As one of the largest agricultural countries in the world, the sustainability of China's crop production system is being concerned widely with its economic development and increasing population. This study adopted emergy analysis to explore the comprehensive performance of this system. A set of emergy based indicator system was used to investigate its economic benefit, environmental pressure and sustainability from 2000 to 2010. The study results show that the purchased nonrenewable input makes the largest contribution to the total input (average value 60.73% of the total input), which mainly derived from agricultural mechanic equipments and chemical fertilizer; on the average, beans has the largest share (20.20%) to the total emergy output, next from rape seed (18.36%), then from peanuts (15.85%), fruits (15.74%), wheat (8.26%), rice (8.07%), corn (7.66%) and cotton (4.60%) accordingly, and the other four categories crops just have a contribution of 1.28%; the production efficiency of China's crop production system has been raised by 11.54% with decrease of the indicator unit emergy value of product (UEVP) from 1.82E09 sej/g to 1.61E09 sej/g, the dependence of this system on economic market has increased by 24.92% with growth of the indicator EIR from 6.22 to 7.77, its economic benefit has been reduced by 0.59% with decline of the indicator EYR from 1.69 to 1.68, and its environmental loading has raised by 57.89% with growth of the indicator ELR from 1.33 to 2.10; the sustainability of China's crop production system is reduced by 37.01% with decrease of the index ESI from 1.27 to 0.80, during this study period. Based on these study results, the following measures should be emphasized in future, including raising the efficiency of purchased non-renewable resources (especially agricultural mechanical equipments and chemical fertilizer), using other methods of cultivation inherently more sustainable (e.g. replacing chemical fertilizer with organic fertilizer, recycling organic wastes, biological control of agricultural pests, use of local renewable energy, and more), strengthening supervision of the related industrial processes and further promoting agricultural environmental protection.     

Trickle or clumped infection process? An analysis of aggregation in the weights of the parasitic roundworm of humans, Ascaris lumbricoides

Studying the distribution of parasitic helminth body size across a population of definitive hosts can advance our understanding of parasite population biology. Body size is typically correlated with egg production. Consequently, inequalities in body size have been frequently measured to infer variation in reproductive success (VRS). Body size is also related to parasite age (time since entering the definitive host) and potentially provides valuable information on the mode of acquisition and establishment of immature (larval) parasites within the host: whether parasites tend to establish singly or in aggregates. The mode of acquisition of soil-transmitted helminths has been a theoretical consideration in the parasitological literature but has eluded data-driven investigation. In this paper, we analyse individual Ascaris lumbricoides weight data collected from a cohort of human hosts before and after re-infection following curative treatment, and explore its distribution within and among individuals in the population. Lorenz curves and Gini coefficients indicate that levels of weight inequality (a proxy for VRS) in A. lumbricoides are lower than other published estimates from animal-helminth systems. We explore levels of intra-host weight aggregation using statistical models to estimate the intraclass correlation coefficient (ICC) while adjusting for covariates using a flexible fractional polynomial transformation approach capable of handling non-linear functional relationships. The estimated ICCs indicate that weights are aggregated within hosts both at equilibrium and after re-infection, suggesting that parasites may establish within the host in clumps. The implications of a clumped infection process are discussed in terms of ascariasis transmission dynamics, control and anthelmintic resistance.     

Does the examiner's experience matter in evaluation of the kinematics of the upper limb?

This study aimed to evaluate test and retest reliability according to examiner experience with the three-dimensional kinematics of the trunk, scapula, and arm segments during flexion and unilateral abduction of the arm. Ten men and 10 women (mean age, 25.1 [1.1] years) participated in this study. Each volunteer participated in six test sessions, four on the first day (two for each examiner) and two on the second day (one for each examiner). A 48-h interval was given between test days. The assessments were made by one examiner with movement analysis experience and a second examiner without experience. For each session (intra-day), the volunteers performed five repetitions of unilateral arm flexions and abductions using their dominant arms. After 1 h, the data were re-collected and all markers were replaced. Data from the trunk, scapula, and arm were analysed at 30°, 60°, 90°, and 120° of arm flexion and abduction using intraclass coefficient correlation, standard error of the measurement, and analysis of variance. The results did not differ between the experienced and inexperienced examiners except for trunk axial rotation at all studied angles and for arm rotation at 120° of abduction. The examiner previously trained in movement analysis marker placement demonstrated the same intra-tester reliability as the inexperienced tester when marker placement accuracy was the variable of interest.