Cosmology and stellar equilibrium using Newtonian hydrodynamics with general relativistic pressure

We revisit the analysis made by Hwang and Noh [JCAP 1310 (2013)] aiming the construction of a Newtonian set of equations incorporating pressure effects typical of the General Relativity theory. We explicitly derive the Hwang-Noh equations, comparing them with similar computations found in the literature. Then, we investigate $i)$ the cosmological expansion, $ii)$ linear cosmological perturbations theory and $iii)$ stellar equilibrium by using the new set of equations and comparing the results with those coming from the usual Newtonian theory, from the Neo-Newtonian theory and from the General Relativity theory. We show that the predictions for the background evolution of the Universe are deeply changed with respect to the General Relativity theory: the acceleration of the Universe is achieved with positive pressure. On the other hand, the behaviour of small cosmological perturbations reproduces the one found in the relativistic context, even if only at small scales. We argue that this last result may open new possibilities for numerical simulations for structure formation in the Universe. Finally, the properties of neutron stars are qualitatively reproduced by Hwang-Noh equations, but the upper mass limit is at least one order of magnitude higher than the one obtained in General Relativity.Comment: 15 pages, 4 figures. Section 2 greatly extended with a post-Newtonian analysis. Final results strengthe

Giant FAZ10 is required for flagellum attachment zone stabilization and furrow positioning in Trypanosoma brucei

The flagellum and flagellum attachment zone (FAZ) are important cytoskeletal structures in trypanosomatids, being required for motility, cell division and cell morphogenesis. Trypanosomatid cytoskeletons contain abundant high molecular mass proteins (HMMPs), but many of their biological functions are still unclear. Here, we report the characterization of the giant FAZ protein, FAZ10, in Trypanosoma brucei, which, using immunoelectron microscopy, we show localizes to the intermembrane staples in the FAZ intracellular domain. Our data show that FAZ10 is a giant cytoskeletal protein essential for normal growth and morphology in both procyclic and bloodstream parasite life cycle stages, with its depletion leading to defects in cell morphogenesis, flagellum attachment, and kinetoplast and nucleus positioning. We show that the flagellum attachment defects are probably brought about by reduced tethering of the proximal domain of the paraflagellar rod to the FAZ filament. Further, FAZ10 depletion also reduces abundance of FAZ flagellum domain protein, ClpGM6. Moreover, ablation of FAZ10 impaired the timing and placement of the cleavage furrow during cytokinesis, resulting in premature or asymmetrical cell division

Correções de pressão na dinâmica de fluidos newtoniana e comparação com a teoria da Relatividade Geral.

O equilíbrio estelar e a cosmologia são ramos da física originadas num só tronco, a relatividade geral. Entretanto é possível descrevê-los sob certas condições utilizando hidrodinâmica newtoniana. O campo de atuação destas equações pode ser estendida com a introdução de um termo de pressão relativística, que atuará como fonte de campo gravitacional. Esse termo de correção ainda não é muito bem entendido de forma que recentemente Hwang e Noh o propuseram alternativamente às teorias hidrodinâmicas semi-relativísticas existentes. Estudaremos os resultados obtidos para as teorias newtonianas, neo-newtonianas e de Hwang-Noh assim como a própria relatividade aplicada a estrelas e cosmologia e os compararemos. Veremos que apesar da previsão de estrelas de nêutrons super gigantes no estudo do equilíbrio estelar, as equações hidrodinâmicas de Hwang-Noh nos trazem, em casos particulares, resultados semelhantes à Relatividade Geral quanto à evolução do universo

Benefits of improved rice husk combustion, Bangladesh (NRI report no. 2764)

The report is structured as follows. Chapter 2 presents the background to this study. Based on secondary data, it first describes the rice milling sector to illustrate the characteristics of the sector and to establish the importance of small scale parboiling rice mills. No secondary data were available either on the socio-economic characteristics of the user group or on the attitudes to technological change among owners and operators of rice mills. This information was important to the design of the project methodology; for indicating the nature of technological improvements acceptable to user groups; for issues of affordability and for subsequent dissemination activities. Section 2.3, draws on the baseline survey carried out in Phase 1, to analyse these characteristics. Chapter 3 first analyses the characteristics of the traditional furnace design and then demonstrates how the new design of furnace-boiler unit has increased combustion efficiency by more than the project objective; improved the working conditions of the workers and increased profitability of the owners. It also sets out the potentials and limitations for wider replications. Chapter 4 focuses on enhancing the production of briquettes using husk from parboiled rice. It describes the current procedures used for briquette production, the difficulties of using husk of parboiled rice, and the improvements developed by this project to address these constraints. Chapter 5 discusses the wider socio-economic benefits that could be generated by the rice husk and bran saved by improved combustion efficiency. It also shows that briquettes, where available, have become the poor man's fuel. Chapter 6 initially set out the characteristics of the rice husk ash in Bangladesh. It then describes the current uses in other countries and identifies potential alternative uses in Bangladesh. Chapter 7 describes the dissemination activities already undertaken and their outcomes and then outlines further dissemination activities that could potentially enhance uptake. Chapter 8 will conclude the report with recommendations and identify further research needs in biomass fuel use

"You should go so that others can come"; The Role of Facilities in Determining an Early Departure after Childbirth in Morogoro Region, Tanzania.

Tanzania is among ten countries that account for a majority of the world's newborn deaths. However, data on time-to-discharge after facility delivery, receipt of postpartum messaging by time to discharge and women's experiences in the time preceding discharge from a facility after childbirth are limited. Household survey of 1267 women who delivered in the preceding 2-14 months; in-depth interviews with 24 women, 12 husbands, and 5 community elders. Two-thirds of women with vaginal, uncomplicated births departed within 12 h; 90 % within 24 h, and 95 % within 48 h. Median departure times varied significantly across facilities (hospital: 23 h, health center: 10 h, dispensary: 7 h, p < 0.001). Quantitative and qualitative data highlight the importance of type of facility and facility amenities in determining time-to-discharge. In multiple logistic regression, level of facility (hospital, health center, dispensary) was the only significant predictor of early discharge (p = 0.001). However across all types of facilities a majority of women depart before 24 h ranging from hospitals (54 %) to health centers (64 %) to dispensaries (74 %). Most women who experienced a delivery complication (56 %), gave birth by caesarean section (90 %), or gave birth to a pre-term baby (70 %) stayed longer than 24 h. Reasons for early discharge include: facility practices including discharge routines and working hours and facility-based discomforts for women and those who accompany them to facilities. Provision of postpartum counseling was inadequate regardless of time to discharge and regardless of type of facility where delivery occurred. Our quantitative and qualitative findings indicate that the level of facility care and comforts existing or lacking in a facility have the greatest effect on time to discharge. This suggests that individual or interpersonal characteristics play a limited role in deciding whether a woman would stay for shorter or longer periods. Implementation of a policy of longer stay must incorporate enhanced postpartum counseling and should be sensitive to women's perceptions that it is safe and beneficial to leave hospitals soon after birth

Factors affecting early identification of pregnant women by community health workers in Morogoro, Tanzania

Background: It is recommended that Antenatal Care (ANC) be initiated within the first trimester of pregnancy for essential interventions, such folic acid supplementation, to be effective. In Tanzania, only 24% of mothers attend their first ANC appointment during their first trimester. Studies have shown that women who have had contact with a health worker are more likely to attend their first antenatal care appointment earlier in pregnancy. Community health workers (CHWs) are in an opportune position to be this contact. This study explored CHW experiences with identifying women early in gestation to refer them to facility-based antenatal care services in Morogoro, Tanzania. Methods: This qualitative study employed 10 semi-structured focus group discussions, 5 with 34 CHWs and 5 with 34 recently delivered women in three districts in Morogoro, Tanzania. A thematic analytical approach was used to identify emerging themes among the CHW and RDW responses.ResultsStudy findings show CHWs play a major role in identifying pregnant women in their communities and linking them with health facilities. Lack of trust and other factors, however, affect early pregnancy identification by the CHWs. They utilize several methods to identify pregnant women, including: asking direct questions to households when collecting information on the national census, conducting frequent household visits and getting information about pregnant women from health facilities. Conclusions: We present a framework for the interaction of factors that affect CHWs' ability to identify pregnant women early in gestation. Further studies need to be conducted investigating optimal workload for CHWs, as well as reasons pregnant women might conceal their pregnancies.USAID through the Health Research Challenge for Impact (HRC) [GHS-A-00-09-00004-00]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The case for launch of an international DNA-based birth cohort study

The global health agenda beyond 2015 will inevitably need to broaden its focus from mortality reduction to the social determinants of deaths, growing inequities among children and mothers, and ensuring the sustainability of the progress made against the infectious diseases. New research tools, including technologies that enable high-throughput genetic and ‘-omics’ research, could be deployed for better understanding of the aetiology of maternal and child health problems. The research needed to address those challenges will require conceptually different studies than those used in the past. It should be guided by stringent ethical frameworks related to the emerging collections of biological specimens and other health related information. We will aim to establish an international birth cohort which should assist low- and middle-income countries to use emerging genomic research technologies to address the main problems in maternal and child health, which are still major contributors to the burden of disease globally

Care Seeking for Neonatal Illness in Low- and Middle-Income Countries: A Systematic Review

Hadley Herbert and colleagues systematically review newborn care-seeking behaviors by caregivers in low- and middle-income countries

Disgust sensitivity is not associated with health in a rural Bangladeshi sample.

Disgust can be considered a psychological arm of the immune system that acts to prevent exposure to infectious agents. High disgust sensitivity is associated with greater behavioral avoidance of disease vectors and thus may reduce infection risk. A cross-sectional survey in rural Bangladesh provided no strong support for this hypothesis. In many species, the expression of pathogen- and predator-avoidance mechanisms is contingent on early life exposure to predators and pathogens. Using childhood health data collected in the 1990s, we examined if adults with more infectious diseases in childhood showed greater adult disgust sensitivity: no support for this association was found. Explanations for these null finding and possible directions for future research are discussed