Symmetries of the Energy-Momentum Tensor: Some Basic Facts

It has been pointed by Hall et al. [1] that matter collinations can be defined by using three different methods. But there arises the question of whether one studies matter collineations by using the ${\cal L}_\xi T_{ab}=0$, or ${\cal L}_\xi T^{ab}=0$ or ${\cal L}_\xi T_a^b=0$. These alternative conditions are, of course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition.Comment: 17 pages, accepted for publication in "Communications in Theoretical Physics

Germin and germin-like proteins: evolution, structure, and function

Germin and germin-like proteins (GLPs) are encoded by a family of genes found in all plants. They are part of the cupin superfamily of biochemically diverse proteins, a superfamily that has a conserved tertiary structure, though with limited similarity in primary sequence. The subgroups of GLPs have different enzyme functions that include the two hydrogen peroxide-generating enzymes, oxalate oxidase (OxO) and superoxide dismutase. This review summarizes the sequence and structural details of GLPs and also discusses their evolutionary progression, particularly their amplification in gene number during the evolution of the land plants. In terms of function, the GLPs are known to be differentially expressed during specific periods of plant growth and development, a pattern of evolutionary subfunctionalization. They are also implicated in the response of plants to biotic (viruses, bacteria, mycorrhizae, fungi, insects, nematodes, and parasitic plants) and abiotic (salt, heat/cold, drought, nutrient, and metal) stress. Most detailed data come from studies of fungal pathogenesis in cereals. This involvement with the protection of plants from environmental stress of various types has led to numerous plant breeding studies that have found links between GLPs and QTLs for disease and stress resistance. In addition the OxO enzyme has considerable commercial significance, based principally on its use in the medical diagnosis of oxalate concentration in plasma and urine. Finally, this review provides information on the nutritional importance of these proteins in the human diet, as several members are known to be allergenic, a feature related to their thermal stability and evolutionary connection to the seed storage proteins, also members of the cupin superfamily

Stability of the pentaquark in a naive string model

The pentaquark is studied in a simple model of confinement where the quarks and the antiquark are linked by flux tubes of minimal cumulated length, and the Coulomb-like interaction, the spin-dependent terms and the antisymmetrization constraints are neglected.. The ground-state is found to be stable against spontaneous dissociation into a meson and a baryon, both in the case of five equal-mass constituents and for a static quark or antiquark surrounded by four equal masses.Comment: 8 pages, 2 figures, minor corrections, references added, to appear in Phys. Rev.

Intersectionality at work: South Asian Muslim women’s experiences of employment and leadership in the United Kingdom

Drawing on qualitative interviews with 20 South Asian heritage, Muslim, female leaders, managers, and supervisors in the United Kingdom, we examine the multi-layered issues and challenges they face in pursuit of employment and leadership positions. The paper offers an intersectional perspective taking into account interconnected and overlapping factors (gender, ethnicity, religion, and family status) that affect not only the issues and challenges these women face in the labour market but also the individual agency and strategies they use to overcome any obstacles in the way of their employment and career. The results show that although Muslim women continue to face a myriad of challenges in the workplace, they are also able to tackle some of these issues through their individual strategies and networks, such as personal networks and further education. The study highlights the need for policymakers and employers to consider intersectionality to enable ethnic minority women’s inclusion and leadership within and outside the workplace

Every student counts: promoting numeracy and enhancing employability

This three-year project investigated factors that influence the development of undergraduates’ numeracy skills, with a view to identifying ways to improve them and thereby enhance student employability. Its aims and objectives were to ascertain: the generic numeracy skills in which employers expect their graduate recruits to be competent and the extent to which employers are using numeracy tests as part of graduate recruitment processes; the numeracy skills developed within a diversity of academic disciplines; the prevalence of factors that influence undergraduates’ development of their numeracy skills; how the development of numeracy skills might be better supported within undergraduate curricula; and the extra-curricular support necessary to enhance undergraduates’ numeracy skills

Study the Band Energy Structure and Absorption Coefficient for PbSe Thin Films

The PbSe alloy was prepared in evacuated quarts tubs by the method of melt quenching from element, the PbSe thin films prepared by thermal evaporation method and deposited at different substrate temperature (Ts) =R.T ,373 and 473K . The thin films that deposited at room temperature (R.T=303)K was annealed at temperature, Ta= R.T, 373 and 473K . By depended on D.C conductivity measurements calculated the density of state (DOS), The density of extended state N(Eext) increases with increasing the Ts and Ta, while the density of localized state N(Eloc) is decreased . We investigated the absorption coefficient (?) that measurement from reflection and transmission spectrum result, and the effect of Ts and Ta on it , also we calculated the tail width for each prepared films

The impact of the menopause transition on the health and wellbeing of women living with HIV: A narrative review

Improvements in survival due to advances in antiretroviral therapy (ART) have led to a shift in the age distribution of those receiving HIV care, with increasing numbers of women living with HIV (WLHIV) reaching menopausal age. We present a narrative literature review of 26 studies exploring the menopause transition in WLHIV, focusing on: (1) natural history (2) symptomatology and management, and (3) immunologic and virologic effects. Data are conflicting on the association between HIV and earlier age at menopause, and the role of HIV-specific factors such as HIV viral load and CD4 count. There are some data to suggest that WLHIV experience more vasomotor and psychological symptoms during the menopause than HIV-negative women, and that uptake of hormone replacement therapy by WLHIV is comparatively low. There is no evidence that menopause affects either CD4 count or response to ART, although there may be increased immune activation in older WLHIV. We conclude that menopause in WLHIV is a neglected area of study. Specific information gaps include qualitative studies on experiences of reproductive ageing; data on the impact of the menopause on women’s quality of life and ability to adhere to health-sustaining behaviors; as well as studies investigating the safety and efficacy of pharmacological and psychosocial interventions. There is likely to be a burden of unmet health need among this growing population, and better data are required to inform optimal provision of care, supporting WLHIV to maintain their health and wellbeing into their post-reproductive years