Numerical simulation based on the discrete element method (DEM) is used to investigate the flow field generated when a cylindrical obstacle is placed in a supersonic granular stream. Robust validation of the simulation model is performed by comparing numerical results with experiments. Experiments are performed using a two-dimensional set-up generating rapid granular flow owing to gravity. DEM simulations demonstrate that a rapid gas-like stream of grains suddenly decelerates across the shock wave and finally collapses into a slow-moving heap at the cylinder. The volume fraction suddenly increases across the shock layer and remains constant thereafter. The flow physics of the shock wave and the granular heap is elucidated through fundamental fluid dynamic quantities such as the velocity, volume fraction, pressure and granular temperature. It is shown that the interaction of grains with a cylindrical obstacle results in the generation of pressure, which is responsible for sustaining static granular heaps on the cylinder. The total pressure is resolved into collisional and streaming components. A streaming pressure is generated owing to velocity fluctuations, and is found to be significant only in the shock wave region. The observations show that the rheological complexity offered by granular shock waves is a direct manifestation of the dissipative and frictional nature of granular collisions. The new insight into the granular heaps could be relevant to a variety of applications involving granular-fluid–solid interactions.

Child labourers are at risk of poorer mental health and once rescued require urgent mental health interventions to ameliorate the long-term impact. In our review, only two published scientific studies evaluated custom-made interventions; other programmes were obtained from non-governmental organisations (NGOs), which need rigorous trial evaluation. We also sought the viewpoints of stakeholders working directly with rescued young people, as well as consulting young people with lived experiences of child labour. We propose that psychoeducational interventions aimed at employees working directly with young people could represent a fruitful approach for low- and middle-income countries in the Asia-Pacific region but also more generally.

This paper highlights unique sites in Ladakh, India, investigated during our 2016 multidisciplinary pathfinding expedition to the region. We summarize our scientific findings and the site's potential to support science exploration, testing of new technologies and science protocols within the framework of astrobiology research. Ladakh has several accessible, diverse, pristine and extreme environments at very high altitudes (3000–5700 m above sea level). These sites include glacial passes, sand dunes, hot springs and saline lake shorelines with periglacial features. We report geological observations and environmental characteristics (of astrobiological significance) along with the development of regolith-landform maps for cold high passes. The effects of the diurnal water cycle on salt deliquescence were studied using the ExoMars Mission instrument mockup: HabitAbility: Brines, Irradiance and Temperature (HABIT). It recorded the existence of an interaction between the diurnal water cycle in the atmosphere and salts in the soil (which can serve as habitable liquid water reservoirs). Life detection assays were also tested to establish the best protocols for biomass measurements in brines, periglacial ice-mud and permafrost melt water environments in the Tso-Kar region. This campaign helped confirm the relevance of clays and brines as interest targets of research on Mars for biomarker preservation and life detection.

A nonlinear mathematical model for innovation diffusion is proposed. The system of ordinary differential equations incorporates variable external influences (the cumulative density of marketing efforts), variable internal influences (the cumulative density of word of mouth) and a logistically growing human population (the variable potential consumers). The change in population density is due to various demographic processes such as intrinsic growth rate, emigration, death rate etc. Thus the problem involves two dynamic variables viz. a non-adopter population density and an adopter population density. The model is analysed qualitatively using the stability theory of differential equations, with the help of the corresponding characteristic equation of the system. The interior equilibrium point can be stable for all time delays to a critical value, beyond which the system becomes unstable and a Hopf bifurcation occurs at a second critical value. Employing normal form theory and a centre manifold theorem applicable to functional differential equations, we derive some explicit formulas determining the stability, the direction and other properties of the bifurcating periodic solutions. Our numerical simulations show that the system behaviour can become extremely complicated as the time delay increases, with a stable interior equilibrium point leading to a limit cycle with one local maximum and minimum per cycle (Hopf bifurcation), then limit cycles with more local maxima and minima per cycle, and finally chaotic solutions.

Oxygen isotope analysis was performed on enamel phosphate of mammalian teeth from archaeological sites Kalli Pachchhim and Dadupur in the central Ganga plain and Charda in the northern Ganga plain. The bulk oxygen isotopic compositions of enamel phosphate from third molars (M3) of Bos indicus individuals belonging to different cultural periods were used to understand the climatic changes during the past 3600 cal yr B.P. Oxygen isotope ratios indicate humid conditions around 3600 cal yr B.P., followed by a trend toward drier conditions until around 2800 cal yr B.P. Then from 2500 to 1500 cal yr B.P. there is a trend toward higher humidity, followed by the onset of a dry period around 1300 cal yr B.P. The study of intratooth δ18O variations in teeth from different periods demonstrates that the monsoon seasonality was prominent. Spatial changes in the amount of annual rainfall are also reflected in the δ18O values. Teeth derived from areas with intense rainfall have lighter isotope ratios compared to teeth from regions receiving less rain, but they show similar seasonal patterns. The long-term paleoclimatic variations reflected by fluctuations in bulk δ18Op values from M3 teeth match well with the regional paleoenvironmental records and show a good correlation to the cultural changes that took place during this time span in Ganga plain.

Goats make up the largest group of ruminant livestock in Nigeria and are strategic in bridging animal protein supply gap and improving the economy of rural households. The hypervariable region 1 (HVR1) of the caprine mitochondrial genome was investigated to better understand genetic diversity important for improving selection for animal breeding and conservation programs. We sequenced and analysed the mitochondrial DNA (mtDNA) HVR1 in 291 unrelated indigenous Nigerian goats (West African Dwarf (WAD), Red Sokoto (RSO) and Sahel (SAH)), randomly sampled from around the country, and compared them with the HVR1 sequences of 336 Indian goats and 12 other sequences in five different species in the genus Capra (C. falconeri, C. ibex nubiana, C. aegagrus, C. cylindricornis and C. sibirica). A total of 139 polymorphic sites from 291 individuals were captured in 204 haplotypes. Within and among population variations were 77.25 and 22.74 percent, respectively. Nigerian goats showed high genetic diversity (0.87) and high FST values, and separate from Indian goats and other wild species. Haplogroups in WAD separates it from RSO and SAH concomitant with a different demographic history. Clear genetic structure was found among Nigerian goat breeds with appreciable variation in mtDNA HVR1 region. This study grouped Nigerian goat breeds into two major groups suggesting two different demographic origins for Northern and Southern breeds. High genetic admixing denotes different maternal origins and in contrast to evidence from goats from Levant and Central Asia, where goats were originally domesticated.

Genetic diversity of a red clover global collection was assessed using 36 simple sequence repeat (SSR) primers representing all seven linkage groups (LGs). The number of fragments amplified ranged from 1 to 6 for all the primers. Primer RCS0060 detected highest number of fragments, whereas four SSRs viz., RCS0899, RCS1594, TPSSR40 and RCS6927 amplified single fragment. Size range of amplicons generated by all the primers varied from 100 to 400 bp. Polymorphism information content values ranged from 0.301 to 0.719 with an average value of 0.605. LG wise diversity analysis showed that LG 3 was most diverse (I = 0.65, Ht = 0.44), whereas LG-1 showed minimum diversity (I = 0.48, Ht = 0.26) for the microsatellites used. Bayesian model-based clustering inferred three genetically distinct populations in the red clover germplasm holding and showed considerable admixture in individuals within clusters. Neighbour-joining analysis showed intermixing of accessions within groups. Principal component analysis plot complemented the clustering shown by Structure and distinguished three populations to greater extent. Analysis of molecular variance showed that 91% of the genetic variation was residing within populations, while 9% variation was among populations. Overall, the results showed that a high level of genetic diversity is prevailing in this worldwide collection of red clover, which can be exploited for its genetic improvement through breeding approaches.