Nuclear suppliers group: finding entry points

As India continues to seek membership of the Nuclear Suppliers Group, Kanica Rakhra reflects on current controls regarding the trade of nuclear material. She argues that these have been unable to take account of the many rapid changes in the international system, and needs to be updated to provide reference points for acceptable behaviour and strengthen the goals of non-proliferation

MATERNAL DEPRESSION AND ANXIETY AND IMPACT ON PHYSICAL, COGNITIVE AND EMOTIONAL DEVELOPMENT OF CHILDREN AT THREE YEARS OF AGE

Perinatal depression and anxiety are defined as depression or anxiety during pregnancy up to one year after birth. Along with the immediate health impacts and losses in productivity for the mother, perinatal depression and anxiety can have long-term detrimental effects on both the mother and child. Studying changes in measures of depression and anxiety through pregnancy, the postpartum period, and beyond can aid in identifying the most suitable time periods for implementation of screening and preventive programs. The primary goal of this study was to examine the course of depression and anxiety in women from early pregnancy to three years postpartum and to identify predictors of depression and anxiety scores across this period. The secondary goal was to examine the role of maternal mental health and high-risk behaviours, as well as other important socio-demographic factors, in physical, cognitive, personal-social, and emotional-behavioural development of three-year-old children. Overall maternal depression and anxiety scores declined across the study time points. Pre-pregnancy maternal mental health was a significant predictor of both longitudinal depression and anxiety scores. Early postpartum stress and affective lability three years after birth were associated with higher longitudinal depression and anxiety scores in the study. Emotional support in all stages of pregnancy and after birth significantly and consistently lowered the average depression scores. Having a not very satisfactory relationship with the father of the child as compared to no relationship significantly increased the depression scores over the study time points. Lagged variable analysis suggested that previous depression scores were more important predictors of subsequent depression scores than previous anxiety scores. Furthermore, early pregnancy depression scores were significant predictors of both depression and anxiety scores. Prenatal maternal mental health (depression, anxiety, stress) was not significantly associated with early childhood development in this study. However, several maternal mental health measures reported after pregnancy were associated with the physical, cognitive, personal-social, emotional, and behavioural development of children at three years of age. Maternal high-risk behaviours (smoking, alcohol consumption, and drug use), independently and in association with maternal family history of perinatal depression, were associated with early childhood development

Modeling and simulation enabled UAV electrical power system design

With the diversity of mission capability and the associated requirement for more advanced technologies, designing modern unmanned aerial vehicle (UAV) systems is an especially challenging task. In particular, the increasing reliance on the electrical power system for delivering key aircraft functions, both electrical and mechanical, requires that a systems-approach be employed in their development. A key factor in this process is the use of modeling and simulation to inform upon critical design choices made. However, effective systems-level simulation of complex UAV power systems presents many challenges, which must be addressed to maximize the value of such methods. This paper presents the initial stages of a power system design process for a medium altitude long endurance (MALE) UAV focusing particularly on the development of three full candidate architecture models and associated technologies. The unique challenges faced in developing such a suite of models and their ultimate role in the design process is explored, with case studies presented to reinforce key points. The role of the developed models in supporting the design process is then discussed

Boiling stable acid phosphatases (BsAPases) in Triticum aestivum induced by phosphate (Pi) deficiency

Nutrient limitation represents a ubiquitous form of environmental abiotic stress and Pi limitation is especially common due to low availability in most soils. As a result, most natural soils have soluble Pi concentrations lower than cytoplasmic Pi concentrations required for plant growth. Acid phosphatases (APases) are widely found in plants having intracellular and extracellular activities. APases are believed to be important for Pi scavenging and remobilization in plants, but role of boiling stable APases in adaptation to Pi stress at germination level has not been critically evaluated. To address this issue, the effect of low phosphate stress (LPS) on boiling stable acid phosphatases in wheat embryos and endosperm was investigated. With comparison to high phosphate condition (HP), a considerable increase in boiling stable acid phosphatase (BsAPase) activity was observed both in embryos and endosperm under LPS treatment. Post-LPS study revealed that BsAPase activity decreased considerably upon relieving the Pi stress. Further, as compared to HP conditions, SDS-PAGE analysis also detected a differential strong band under LPS conditions, which disappeared upon relieving Pi stress. These findings suggest that changes in the phosphatase enzymes might play important roles in adaptation of germinating seeds under Pi stress conditions. Based upon these results, a possible physiological role of BsAPases in germinating wheat seeds is discussed

Purification and characterization of a heat-stable acid phosphatase from chickpea

Acid phosphatases (APases) form a group of enzymes catalyzing hydrolysis of avariety of phosphate esters in the acidic environments. APases are believed to increaseorthophosphate (Pi) availability under phosphorous deficient conditions. The APase fromchickpea was purified by ethanol precipitation, followed by successive chromatographies onDEAE-Cellulose and Sephadex G-150. The enzyme was purified 73-folds. The optimumtemperature and pH for enzyme activity were 50 °C and 5.5, respectively. All metal saltsexcept ZnCl2 and HgCl2 were tolerated and did not adversely affect APase activity. Thepurified enzyme had a lower Km (0.25 mM) and higher Vmax (9 mM) for PNPP. The APase hadbroad substrate specificity with PNPP and natural substrates

Accumulation of water stress-responsive class-Ill type of boiling stable peroxidases (BsPOD) in different cultivars of wheat [Triticum aestivum)

Drought is one of the most important abiotic stress that affects plant growth and productivity. Class-III Peroxidases (PODs) are known to maintain oxidative stress induced-ROS at sub-lethal levels in plants under abiotic stress conditions, but, studies documenting how drought regulates boiling stable class-III PODs are still a matter of conjecture. In this study, changes in total protein content (TPC), water content (WC), H2O2, malondialdehyde (MDA) and ROS scavenging class-III boiling stable POD were studied in the shoots of seven cultivars of wheat at different stages of drought treatment (3 days: D3, 5 days: D5 and 7 days: D7) followed by recovery from stress (post stress: PS). Simultaneous analysis of H2O2, MDA contents and activities of ROS-scavenging class-III boiling stable POD (BsPOD) enzymes gave an integrative view of physiological state and detoxifying potential under conditions of sensitivity and tolerance. Drought stress increased TPC and decreased WC in all the cultivars of wheat. H2O2 content decreased considerably under various stage of drought stress in a genotype dependent manner. As a result, amount of MDA, a product of lipid peroxidation, was also less in all the cultivars at all stress durations. During initial stress conditions (D3), a marked increase in BsPOD activity was observed in cultivars PBW343, PBW550, PBW175, DBW17 and HD2967. An especially high increase (55-fold) was noticed in PBW175 accompanied by enhanced expression of boiling stable POD isoenzyme(s) suggesting that this cultivar has more efficient mechanisms to scavenge ROS species. In addition, this cultivar has also maintained higher BsPOD activity when the stress duration increased from D3 to D7. The other cultivars having lowest enzyme activities are mentioned as cultivars sensitive to drought stress. Compared to stress, significantly higher soluble protein content accompanied by BsPOD activity was observed after the exposure to recovery conditions in the majority of cultivars. Based on these results, the possible role of BsPOD activity and isoenzyme(s) to perform biological antioxidative reactions to combat drought-induced oxidative stress was discussed

Multi-sample differential protection scheme in DC microgrids

This paper proposes a novel solution to the issue of protection instability caused by time synchronization error in high-speed differential protection schemes for DC microgrids. DC microgrids provide a more efficient platform to integrate fast-growing renewable energy sources, energy storage systems, and electronic loads. However, the integration of distributed generators (DG) may result in variable fault current magnitude and direction during fault conditions, potentially causing mis-coordination of conventional time graded overcurrent relays. One identified solution to this issue utilizes high-speed differential protection schemes to maintain effective selectivity in DG-dominated DC microgrids. However, as DC short-circuit fault currents are highly transient, microseconds of synchronization error in the measured line currents may cause protection stability issues, whereby mal-operation of relays may occur as a result of faults external to the protected zone. This paper investigates the impact of time synchronization errors for high-speed differential protection in DC distribution systems. It then proposes a multi-sample differential (MSD) scheme that performs multiple differential comparisons over a sampling window to ensure the stability of high-speed differential protection schemes for external faults whilst maintaining sensitivity to internal faults

Increased acetabular subchondral bone density is associated with cam-type femoroacetabular impingement

SummaryObjectiveFemoroacetabular impingement (FAI) has been associated with significant acetabular cartilage damage and subsequent degenerative arthritis. Subchondral bone, often neglected in osteoarthritis studies, may play an important role in the degenerative cascade. Hence the goal of this study was to assess acetabular subchondral bone mineral density (BMD) in subjects with asymptomatic or symptomatic cam deformities compared to normal control subjects. The relationship between BMD and the alpha angle, a quantitative measure of the deformity, was also analyzed.MethodsPatients diagnosed with symptomatic cam FAI were recruited (‘Surgical’) as well as subjects from the general asymptomatic population, classified from CT imaging as normal (‘Control’) or having a cam deformity (‘Bump’) based on their alpha angle measurement. There were 12 subjects in each group. All subjects underwent a CT scan with a calibration phantom. BMD was calculated in regions of interest around the acetabulum from CT image intensity and the phantom calibration. BMD was compared between groups using spine BMD as a covariate. The relationship between BMD and alpha angle was assessed by linear regression.ResultsIn the antero-superior regions bone density was 15–34% higher in the Bump group (P < 0.05) and 14–38% higher in the Surgical group (P < 0.05) compared to Controls. BMD correlated positively with the alpha angle measurements (R2 = 0.44, P < 0.001).ConclusionBMD was elevated in subjects with cam-type deformities, with the severity of the deformity more correlative than symptom status. Similarities to the symptomatic group suggest that hips with an asymptomatic deformity may already be in early stages of joint degeneration