Changes in species richness and composition in European acidic grasslands over the past 70 years: the contribution of cumulative atmospheric nitrogen deposition

Our study investigates the negative impact of nitrogen (N) deposition on species richness in acidic grasslands, based on a temporal comparison of vegetation data spanning a period of almost 70 years. We compiled a large data base of plots assigned to the Violion caninae grassland type, composed of managed, but unfertilized semi-natural grasslands on nutrient-poor, acidic soils. In total 1114 plots, mainly from Great Britain, the Netherlands and Germany, were compiled, dating back to 1939. Environmental site information included geographical and soil (mean Ellenberg values) variables as well as estimates of cumulative N and sulphur (S) deposition since 1939. Statistical analyses were carried out separately for the data subsets from the three regions. In all regions, the vegetation differentiation was mainly related to soil acidity and nutrient availability, as well as to the year of sampling and the cumulative amounts of N and S deposition. Plot-species richness of vascular plants and bryophytes (analysed for Great Britain only) decreased with time and analyses suggest these are affected by various factors, notably soil pH, but also latitude and cumulative N deposition. The latter explained more of the variation in species number than the year of sampling and cumulative S deposition, which supports the interpretation that the decline in species richness is mainly caused by increasing N availability and less by altered management and soil acidification. For Great Britain and Germany, cumulative N deposition showed a strong negative relationship with several biodiversity measures, especially the proportion of dicots, whereas it was positively related to the proportion of grass species. In general, our results give temporal evidence for the negative effect of N deposition on species richness in semi-natural vegetation.     

Population Genetics of the Washington National Primate Research Center's (WaNPRC) Captive Pigtailed Macaque (Macaca nemestrina) Population

Pigtailed macaques (Macaca nemestrina) provide an important model for biomedical research on human disease and for studying the evolution of primate behavior. The genetic structure of captive populations of pigtailed macaques is not as well described as that of captive rhesus (M. mulatta) or cynomolgus (M. fascicularis) macaques. The Washington National Primate Research Center houses the largest captive colony of pigtailed macaques located in several different housing facilities. Based on genotypes of 18 microsatellite (short tandem repeat [STR]) loci, these pigtailed macaques are more genetically diverse than captive rhesus macaques and exhibit relatively low levels of inbreeding. Colony genetic management facilitates the maintenance of genetic variability without compromising production goals of a breeding facility. The periodic introduction of new founders from specific sources to separate housing facilities at different times influenced the colony's genetic structure over time and space markedly but did not alter its genetic diversity significantly. Changes in genetic structure over time were predominantly due to the inclusion of animals from the Yerkes National Primate Research Center in the original colony and after 2005. Strategies to equalize founder representation in the colony have maximized the representation of the founders’ genomes in the extant population. Were exchange of animals among the facilities increased, further differentiation could be avoided. The use of highly differentiated animals may confound interpretations of phenotypic differences due to the inflation of the genetic contribution to phenotypic variance of heritable traits. Am. J. Primatol. 74:1017‐1027, 2012. © 2012 Wiley Periodicals, Inc.     

Behavioural notes on the Neotropical parasocial spider wasp Ageniella (Lissagenia) flavipennis (Banks) (Hymenoptera: Pompilidae), with host association

1. Ageniella is a species‐rich group of spider wasps restricted to the New World. Knowledge regarding the behaviour of this genus is based mainly on the Nearctic species, which have been reported to nest solitarily in the soil. This study reports for the first time the nesting behaviour, with host association of Ageniella (Lissagenia) flavipennis Banks. 2. Behavioural aspects on the nesting of A. flavipennis were observed from a study of six nests found in an Atlantic Forest conservation area in São Paulo State, Brazil. Host specimens were collected from a nest, as well as while being carried by an A. flavipennis individual. 3. The present study reports the A. flavipennis females cohabiting or nesting solitarily in mud nests, indicating that this spider wasp shows some lower level of parasociality. In addition, the spider Enoploctenus cyclothorax (Bertkau) was reported for the first time as host. As has been observed for other Ageniellini, females of A. flavipennis amputate the host's legs and transport the spider to the nest, flying or walking forward. 4. Communal behaviour has been reported for species of different genera of Pompilidae, such as Macromeris Lepeletier, Paragenia Bingham and Auplopus Spinola. Recent phylogenetic analyses suggest that the Lissagenia species are more closely related to the other Ageniellini genera than to the other Ageniella species. The present information on nesting and prey could contribute towards a more conclusive phylogenetic position of Lissagenia.     

Evergreen foliage allows early hatching in a pine processionary moth and escape from predation

1. Seasonal variation in leaf quality and climate conditions often imposes constraints on the temporal occurrence of tree‐feeding insect larvae, but the seasonal effects of predation have received limited attention. In temperate climate zones, both the abundance and activity of predators can be expected to vary over time. 2. The study reported herein examined the impact of temporal variation in predator activity levels on the life history of an herbivorous insect feeding on a constant food source: previous‐year needles of Scots pine (Pinus sylvestris L.). In field experiments, the survival and growth rates of colonies of Thaumetopoea pinivora Treitschke larvae that had been manipulated to hatch at three different dates were compared. Eggs of T. pinivora usually hatch by mid‐April in southern Sweden, which is earlier than most other herbivorous insects that overwinter as eggs in this region. 3. Predator exclusion experiments indicated that larvae which hatched later than April experienced a higher level of predator activity, mainly by ants. The final larval size and the timing of pupation were not affected by hatching date. First instar larvae were more extensively preyed on than second instars. 4. The life history of herbivore species can be affected by seasonal variation in predation pressures. This study suggests that early hatching in a lepidopteran species can allow a temporal escape from predation during the vulnerable early life stages.     

Nocturnal passerine migration without tailwind assistance

Nocturnal passerine migrants could substantially reduce the amount of energy spent per distance covered if they fly with tailwind assistance and thus achieve ground speeds that exceed their airspeeds (the birds’ speed in relation to the surrounding air). We analysed tracking radar data from two study sites in southern and northern Scandinavia and show that nocturnally migrating passerines, during both spring and autumn migration, regularly travelled without tailwind assistance. Average ground and airspeeds of the birds were strikingly similar for all seasonal and site‐specific samples, demonstrating that winds had little overall influence on the birds’ resulting travel speeds. Distributions of wind effects, measured as (1) the difference between ground and airspeed and (2) the tail/headwind component along the birds’ direction of travel, showed peaks close to a zero wind effect, indicating that the migratory flights often occurred irrespective of wind direction. An assessment of prevailing wind speeds at the birds’ mean altitude indicated a preference for lower wind speeds, with flights often taking place in moderate winds of 3–10 m/s. The limited frequency of wind‐assisted flights among the nocturnal passerine migrants studied is surprising and in clear contrast to the strong selectivity of tailwinds exhibited by some other bird groups. Relatively high costs of waiting for favourable winds, rather low probabilities of occurrence of tailwind conditions and a need to use a large proportion of nights for flying are probably among the factors that explain the lack of a distinct preference for wind‐assisted flights among nocturnal passerine migrants.     

Seasonal changes in a cactus‐hoverfly (Diptera: Syrphidae) network

1. We analysed a cacti‐syrphid community focusing on the exploitation of decaying cacti resources by the flies, i.e. if exploitation exhibited a nested topology as a structural pattern, or whether it was temporally random. If availability of cactus resources was predictable during the rainy season, it would then be exploited by a more structured community, or as resource availability would be unpredictable during the dry season, we should expect it to be exploited by a random community. 2. We registered 12 Copestylum species (9 in dry and 11 in rainy season). Four cactus species were recorded per season, three were shared between seasons. 3. The community of Copestylum larvae in the rainy season was not randomly assembled but highly nested, revealing a highly structured pattern of resource use. It exhibited a random organization for the dry season. The high nestedness value obtained for the rainy season suggests that factors along with competition must play a major role in determining community structure. 4. Succession in the cacti‐syrphid community mediated by microorganisms involved in necrosis is an important factor structuring nested subsets. The studied networks were small, which may limit the power of the analysis, and strong conclusions could also be limited.     

Proceedings of the signature series symposium “cellular therapies for orthopaedics and musculoskeletal disease proven and unproven therapies—promise,facts and fantasy,” international society for cellular therapies,montreal, canada,may 2, 2018

The Signature Series Symposium “Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies—Promise, Facts and Fantasy” was held as a pre-meeting of the 26^th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions.     

STAKEHOLDER PERSPECTIVES ON ETHICAL CHALLENGES IN HIV VACCINE TRIALS IN SOUTH AFRICA

There is little published literature on the ethical concerns of stakeholders in HIV vaccine trials. This study explored the ethical challenges identified by various stakeholders, through an open-ended, in-depth approach. While the few previous studies have been largely quantitative, respondents in this study had the opportunity to spontaneously identify the issues that they perceived to be of priority concern in the South African context. Stakeholders spontaneously identified the following as ethical priorities: informed consent, social harms, collaborative relationships between research stakeholders, the participation of children and adolescents, access to treatment for participants who become infected with HIV, physical harms, fair participant and community selection, confidentiality, benefits, and payment.
While there is some speculation that research in developing countries poses special ethical challenges, overall no issues were identified that have not been anticipated in international guidance, literature and popular frameworks. However, the South African context affords a distinctive gloss to these expected issues; for example, respondents were concerned that the predominant selection of black participants may perpetuate racist practices of apartheid. Stakeholders should be aware of contextual factors impacting on the implementation of ethical principles. We make a series of recommendations for South African trials, including amendments to the ethical-legal framework and research policies, and, for further research.     

Urinary 5-aminolevulinic acid in lead-exposed children

Lead intoxication can interfere with haem synthesis and alter the concentration of haem precursors, such as the neurotoxin 5-aminolevulinic acid, in plasma and urine. The relationship between blood lead concentration (PbB), a biomarker of lead exposure, and 5-aminolevulinic acid concentration in urine (ALAU), a biomarker of the early biological effect of lead, was examined in lead-exposed children. ALAU was assayed by chemical derivatization and high performance liquid chromatography with fluorescence detection. The study subjects were 79 children with moderate to high lead exposure recruited from a lead-poisoning prevention clinic. Their urine had been previously analysed for creatinine (CR) concentration and the benzene metabolite trans,trans- muconic acid, and their blood had been analysed for lead. We found that ALAU was not correlated with PbB (Spearman r=0.088, p=0.44), but the ratio ALAU/CR was correlated with PbB (Spearman r=0.22, p=0.054). Creatinine and ALAU concentrations were higher in urine samples collected in the afternoon than those collected in the morning, a finding that is consistent with known diurnal variation. However the ratio ALAU/CR was not different in morning and afternoon urines, supporting the use of creatinine adjustment of ALAU analysis of spot urine samples. In view of the neurotoxic properties of ALA, future validation studies of biomarkers of lead exposure and effect in children should include ALAU or ALAU/CR as potential markers of lead effect.