Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

Global Burden of Sickle Cell Anaemia in Children under Five, 2010–2050: Modelling Based on Demographics,Excess Mortality,and Interventions

Background

The global burden of sickle cell anaemia (SCA) is set to rise as a consequence of improved survival in high-prevalence low- and middle-income countries and population migration to higher-income countries. The host of quantitative evidence documenting these changes has not been assembled at the global level. The purpose of this study is to estimate trends in the future number of newborns with SCA and the number of lives that could be saved in under-five children with SCA by the implementation of different levels of health interventions.

Methods and Findings

First, we calculated projected numbers of newborns with SCA for each 5-y interval between 2010 and 2050 by combining estimates of national SCA frequencies with projected demographic data. We then accounted for under-five mortality (U5m) projections and tested different levels of excess mortality for children with SCA, reflecting the benefits of implementing specific health interventions for under-five patients in 2015, to assess the number of lives that could be saved with appropriate health care services. The estimated number of newborns with SCA globally will increase from 305,800 (confidence interval [CI]: 238,400–398,800) in 2010 to 404,200 (CI: 242,500–657,600) in 2050. It is likely that Nigeria (2010: 91,000 newborns with SCA [CI: 77,900–106,100]; 2050: 140,800 [CI: 95,500–200,600]) and the Democratic Republic of the Congo (2010: 39,700 [CI: 32,600–48,800]; 2050: 44,700 [CI: 27,100–70,500]) will remain the countries most in need of policies for the prevention and management of SCA. We predict a decrease in the annual number of newborns with SCA in India (2010: 44,400 [CI: 33,700–59,100]; 2050: 33,900 [CI: 15,900–64,700]). The implementation of basic health interventions (e.g., prenatal diagnosis, penicillin prophylaxis, and vaccination) for SCA in 2015, leading to significant reductions in excess mortality among under-five children with SCA, could, by 2050, prolong the lives of 5,302,900 [CI: 3,174,800–6,699,100] newborns with SCA. Similarly, large-scale universal screening could save the lives of up to 9,806,000 (CI: 6,745,800–14,232,700) newborns with SCA globally, 85% (CI: 81%–88%) of whom will be born in sub-Saharan Africa. The study findings are limited by the uncertainty in the estimates and the assumptions around mortality reductions associated with interventions.

Conclusions

Our quantitative approach confirms that the global burden of SCA is increasing, and highlights the need to develop specific national policies for appropriate public health planning, particularly in low- and middle-income countries. Further empirical collaborative epidemiological studies are vital to assess current and future health care needs, especially in Nigeria, the Democratic Republic of the Congo, and India. Please see later in the article for the Editors'' Summary     

Comparative multilocus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation

While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species‐specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree‐killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles’ entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long‐standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced.     

Polarization of Myosin II Refines Tissue Material Properties to Buffer Mechanical Stress

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Functional diversity of leaf nitrogen concentrations drives grassland carbon fluxes

Little is known about the role of plant functional diversity for ecosystem‐level carbon (C) fluxes. To fill this knowledge gap, we translocated monoliths hosting communities with four and 16 sown species from a long‐term grassland biodiversity experiment (‘The Jena Experiment’) into a controlled environment facility for ecosystem research (Ecotron). This allowed quantifying the effects of plant diversity on ecosystem C fluxes as well as three parameters of C uptake efficiency (water and nitrogen use efficiencies and apparent quantum yield). By combining data on ecosystem C fluxes with vegetation structure and functional trait‐based predictors, we found that increasing plant species and functional diversity led to higher gross and net ecosystem C uptake rates. Path analyses and light response curves unravelled the diversity of leaf nitrogen concentration in the canopy as a key functional predictor of C fluxes, either directly or indirectly via LAI and aboveground biomass.     

Widespread polyphyly among Alopiinae snail genera: when phylogeny mirrors biogeography more closely than morphology

Consider a group of species that is evenly divided by an easily identifiable complex morphological character. Most biologists would assume that this character should provide better phylogenetic information than, say, the spatial distribution of these species over a fairly continuous 500-km radius area. Paradoxically, this is not the case among terrestrial snail genera in the clausiliid subfamily Alopiinae. Phylogenetic analysis using the nuclear markers ITS1/ITS2 and mitochondrial markers COI/12S reveals widespread homoplasy in the clausilial apparatus (a complex aperture-closing mechanism), and concomitant extensive polyphyly among Carinigera, Isabellaria, and Sericata. In contrast, phylogenetic relationships as revealed by molecular data are closely congruent with biogeography at a relatively small scale. A combination of extremely low vagility and extremely high morphological convergence has conspired to produce this unexpected result. Implications as to the function of the clausilial apparatus are discussed.     

Microtubule release from the centrosome in migrating cells

In migrating cells, force production relies essentially on a polarized actomyosin system, whereas the spatial regulation of actomyosin contraction and substrate contact turnover involves a complex cooperation between the microtubule (MT) and the actin filament networks (Goode, B.L., D.G. Drubin, and G. Barnes. 2000. Curr. Opin. Cell Biol., 12:63-71). Targeting and capture of MT plus ends at the cell periphery has been described, but whether or not the minus ends of these MTs are anchored at the centrosome is not known. Here, we show that release of short MTs from the centrosome is frequent in migrating cells and that their transport toward the cell periphery is blocked when dynein activity is impaired. We further show that MT release, but not MT nucleation or polymerization dynamics, is abolished by overexpression of the centrosomal MT-anchoring protein ninein. In addition, a dramatic inhibition of cell migration was observed; but, contrary to cells treated by drugs inhibiting MT dynamics, polarized membrane ruffling activity was not affected in ninein overexpressing cells. We thus propose that the balance between MT minus-end capture and release from the centrosome is critical for efficient cell migration.