Changing livelihoods in rural Eastern Cape, South Africa (2002–2016): Diminishing employment and expanding social protection

This is evident in South Africa’s former ‘homelands’, the site where this study examined changes in rural livelihoods over a 14-year period. Detailed survey data (collected in 2002 and 2016) from two villages in the Pondoland region of Eastern Cape province, and augmented by in-depth fieldwork, are analysed to explore the drivers of contemporary livelihood change

Auger Electron Cascades in Water and Ice

Secondary electron cascades can induce significant ionisation in condensed matter due to electron-atom collisions. This is of interest in the context of diffraction and imaging using X-rays, where radiation damage is the main limiting factor for achieving high resolution data. Here we present new results on electron-induced damage on liquid water and ice, from the simulation of Auger electron cascades. We have compared our theoretical estimations to the available experimental data on elastic and inelastic electron-molecule interactions for water and found the theoretical results for elastic cross sections to be in very good agreement with experiment. As a result of the cascade we find that the average number of secondary electrons after 100 fs in ice is about 25, slightly higher than in water, where it is about 20. The difference in damage between ice and water is discussed in the context of sample handling for biomolecular systems.Comment: 19 pages, 8 figures. Includes slight corrections to the version submitted for publicatio

Estrogen activation of microglia underlies the sexually dimorphic differences in Nf1 optic glioma-induced retinal pathology

Children with neurofibromatosis type 1 (NF1) develop low-grade brain tumors throughout the optic pathway. Nearly 50% of children with optic pathway gliomas (OPGs) experience visual impairment, and few regain their vision after chemotherapy. Recent studies have revealed that girls with optic nerve gliomas are five times more likely to lose vision and require treatment than boys. To determine the mechanism underlying this sexually dimorphic difference in clinical outcome, we leveraged Nf1 optic glioma (Nf1-OPG) mice. We demonstrate that female Nf1-OPG mice exhibit greater retinal ganglion cell (RGC) loss and only females have retinal nerve fiber layer (RNFL) thinning, despite mice of both sexes harboring tumors of identical volumes and proliferation. Female gonadal sex hormones are responsible for this sexual dimorphism, as ovariectomy, but not castration, of Nf1-OPG mice normalizes RGC survival and RNFL thickness. In addition, female Nf1-OPG mice have threefold more microglia than their male counterparts, and minocycline inhibition of microglia corrects the retinal pathology. Moreover, pharmacologic inhibition of microglial estrogen receptor-β (ERβ) function corrects the retinal abnormalities in female Nf1-OPG mice. Collectively, these studies establish that female gonadal sex hormones underlie the sexual dimorphic differences in Nf1 optic glioma–induced retinal dysfunction by operating at the level of tumor-associated microglial activation

Space-time evolution of electron cascades in diamond

Here we describe model calculations to follow the spatio-temporal evolution of secondary electron cascades in diamond. The band structure of the insulator has been explicitly incorporated into the calculations as it affects ionizations from the valence band. A Monte-Carlo model was constructed to describe the path of electrons following the impact of a single electron of energy E 250 eV. The results show the evolution of the secondary electron cascades in terms of the number of electrons liberated, the spatial distribution of these electrons, and the energy distribution among the electrons as a function of time. The predicted ionization rates (5-13 electrons in 100 fs) lie within the limits given by experiments and phenomenological models. Calculation of the local electron density and the corresponding Debye length shows that the latter is systematically larger than the radius of the electron cloud. This means that the electron gas generated does not represent a plasma in a single impact cascade triggered by an electron of E 250 eV energy. This is important as it justifies the independent-electron approximation used in the model. At 1 fs, the (average) spatial distribution of secondary electrons is anisotropic with the electron cloud elongated in the direction of the primary impact. The maximal radius of the cascade is about 50 A at this time. As the system cools, energy is distributed more equally, and the spatial distribution of the electron cloud becomes isotropic. At 90 fs maximal radius is about 150 A. The Monte-Carlo model described here could be adopted for the investigation of radiation damage in other insulators and has implications for planned experiments with intense femtosecond X-ray sources.Comment: 26 pages, latex, 13 figure

Bone cylinder plug and coil technique for accurate pedicle localization in thoracic spine surgery: A technical note.

Intraoperative identification of the correct level during thoracic spine surgery is essential to avoid wrong-level procedures. Despite technological progress, intraoperative imaging modalities for identifying the correct thoracic spine level remain unreliable and often lead to wrong-level surgery. To counter potential wrong-level operations, here, we have proposed a novel pedicle/bone cylinder marking technique for use in the thoracic spine utilizing biplanar fluoroscopy and confirmed with computed tomography (CT). First, under fluoroscopic guidance, a bone cylinder is removed from the correct thoracic pedicle. Next, endovascular coils are packed into the cancellous bone defect followed by reinsertion of the bony plug. The patient then undergoes a CT scan of the entire thoracolumbosacral spine to precisely identify the marked level before surgery. We utilized this bone cylinder plug/coil technique to identify the T9-T10 level in a 56-year-old female with a soft thoracic disc herniation. The index thoracic pedicle was successfully localized before performing the unilateral minimally invasive laminectomy followed by the transpedicular thoracic disc excision. The bone cylinder plug/coil technique is a safe and effective method for marking the correct level in thoracic spine surgery, while also reducing the operative time

Structural variability and the incoherent addition of scattered intensities in single-particle diffraction

X-ray lasers may allow structural studies on single particles and biomolecules without crystalline periodicity in the samples. We examine here the effect of sample dynamics as a source of structural heterogeneity on the resolution of the reconstructed image of a small protein molecule. Structures from molecular-dynamics simulations of lysozyme were sampled and aligned. These structures were then used to calculate diffraction patterns corresponding to different dynamic states. The patterns were incoherently summed and the resulting data set was phased using the oversampling method. Reconstructed images of hydrated and dehydrated lysozyme gave resolutions of 3.7 Å and 7.6 Å, respectively. These are significantly worse than the root-mean-square deviation of the hydrated ͑2.7 Å for all atoms and 1.45 Å for C-␣ positions͒ or dehydrated ͑3.7 Å for all atoms and 2.5 Å for C-␣ positions͒ structures. The noise introduced by structural dynamics and incoherent addition of dissimilar structures restricts the maximum resolution to be expected from direct image reconstruction of dynamic systems. A way of potentially reducing this effect is by grouping dynamic structures into distinct structural substates and solving them separately

A systematic review on health resilience to economic crises

Background The health effects of recent economic crises differ markedly by population group. The objective of this systematic review is to examine evidence from longitudinal studies on factors influencing resilience for any health outcome or health behaviour among the general population living in countries exposed to financial crises. Methods We systematically reviewed studies from six electronic databases (EMBASE, Global Health, MEDLINE, PsycINFO, Scopus, Web of Science) which used quantitative longitudinal study designs and included: (i) exposure to an economic crisis; (ii) changes in health outcomes/behaviours over time; (iii) statistical tests of associations of health risk and/or protective factors with health outcomes/behaviours. The quality of the selected studies was appraised using the Quality Assessment Tool for Quantitative Studies. PRISMA reporting guidelines were followed. Results From 14,584 retrieved records, 22 studies met the eligibility criteria. These studies were conducted across 10 countries in Asia, Europe and North America over the past two decades. Ten socio-demographic factors that increased or protected against health risk were identified: gender, age, education, marital status, household size, employment/occupation, income/ financial constraints, personal beliefs, health status, area of residence, and social relations. These studies addressed physical health, mortality, suicide and suicide attempts, mental health, and health behaviours. Women’s mental health appeared more susceptible to crises than men’s. Lower income levels were associated with greater increases in cardiovascular disease, mortality and worse mental health. Employment status was associated with changes in mental health. Associations with age, marital status, and education were less consistent, although higher education was associated with healthier behaviours. Conclusions Despite widespread rhetoric about the importance of resilience, there was a dearth of studies which operationalised resilience factors. Future conceptual and empirical research is needed to develop the epidemiology of resilience

First Bio-Anthropological Evidence for Yamnaya Horsemanship.

The origins of horseback riding remain elusive. Scientific studies show that horses were kept for their milk similar to 3500 to 3000 BCE, widely accepted as indicating domestication. However, this does not confirm them to be ridden. Equipment used by early riders is rarely preserved, and the reliability of equine dental and mandibular pathol-ogies remains contested. However, horsemanship has two interacting components: the horse as mount and the human as rider. Alterations associated with riding in human skeletons therefore possibly provide the best source of information. Here, we report five Yamnaya individuals well-dated to 3021 to 2501 calibrated BCE from kurgans in Romania, Bulgaria, and Hungary, displaying changes in bone morphology and distinct pathologies associated with horseback riding. These are the oldest humans identified as riders so far.Peer reviewe

Fine-scale sampling uncovers the complexity of migrations in 5th–6th century Pannonia

As the collapse of the Western Roman Empire accelerated during the 4th and 5th centuries, arriving "barbarian" groups began to establish new communities in the border provinces of the declining (and eventually former) empire. This was a time of significant cultural and political change throughout not only these border regions but Europe as a whole.1,2 To better understand post-Roman community formation in one of these key frontier zones after the collapse of the Hunnic movement, we generated new paleogenomic data for a set of 38 burials from a time series of three 5th century cemeteries3,4,5 at Lake Balaton, Hungary. We utilized a comprehensive sampling approach to characterize these cemeteries along with data from 38 additional burials from a previously published mid-6th century site6 and analyzed them alongside data from over 550 penecontemporaneous individuals.7,8,9,10,11,12,13,14,15,16,17,18,19 The range of genetic diversity in all four of these local burial communities is extensive and wider ranging than penecontemporaneous Europeans sequenced to date. Despite many commonalities in burial customs and demography, we find that there were substantial differences in genetic ancestry between the sites. We detect evidence of northern European gene flow into the Lake Balaton region. Additionally, we observe a statistically significant association between dress artifacts and genetic ancestry among 5th century genetically female burials. Our analysis shows that the formation of early Medieval communities was a multifarious process even at a local level, consisting of genetically heterogeneous groups