123 research outputs found
Disaggregation Model of Tigris River Inflow into a Proposed Makhol Reservoir Using Parametric Approach
Since Makhol dam is planned to be constructed on Tigris River to the north of Baiji discharge measurement station, it is essential to study the nature of inflow into this reservoir. The information concerning this inflow is of great help in operating and management of the prospective reservoir. From our point of view, it is necessary to know how these inflows are distributed and contributed to Tigris from different upstream sources. Disaggregation flow models are stochastic generation techniques, that used to divided data into lower time scales from higher time scales using parametric approaches with two main categories: spatial and temporal. In the streamflow disaggregation model, historical data statistics (mean, skewness, standard deviation, maximum, and minimum) can be preserved while distributing single-site values to several sites in space and time. In this study, the aggregated streamflows data at a key station will be disaggregated into a corresponding series of discharges at sub-stations that are statistically similar to those observed by applying Stochastic Analysis Modeling and Simulation (SAMS 2010) software. To investigate the appropriate the disaggregation method for modeling monthly flow data, we used the annual and monthly data flow of five gauging stations in the Tigres River in Iraq (Mosul Dam station on Tigris river, Asmawah on AlKhazir river, Eski Kalak on Upper Zab, Dibs Dam on Lower Zab, and Baiji station on Tigris river) for the duration 2000â2020. The application approach's statistical outcomes were contrasted with their historical counterparts and the results showed that most years and months at all stations were in good agreement with the historical data. Therefore, we argue that this method have ability to be used when making decisions about water management strategies in these regions which is essential for water resource managers and decision makers
Continuum of care in maternal, newborn and child health in Pakistan: analysis of trends and determinants from 2006 to 2012
Iqbal S, Maqsood S, Zakar R, Zakria Zakar M, Fischer F. Continuum of care in maternal, newborn and child health in Pakistan: analysis of trends and determinants from 2006 to 2012. BMC Health Services Research. 2017;17(1): 189.Background
Pakistan, being a developing country, presents the dismal picture of maternal and neonatal mortality and morbidity. The majority of maternal and neonatal deaths could be avoided if Continuum of Care (CoC) is provided in a structured pathway from pregnancy to birth and to the first week of life of the newborn child. This study aimed to analyse the trends of CoC at all three levels (antenatal care, skilled delivery and postpartum care) and to identify various factors affecting the continuation in receiving CoC in Pakistan during 2006 to 2012.
Methods
Secondary data analysis was performed on nationally representative data from the last two iterations of Pakistan Demographic and Health Survey (PDHS), conducted during 2006/07 to 2012/13. The analysis is limited to women of the reproductive age group (15â49 years) who gave birth during the last five years preceding both surveys. This leads to a sample size of 5,724 and 7,461 respondents from PDHS 2006/07 and 2012/13 respectively. The association between CoC and several factors, including individual attributes (reproductive status), family influences, community context, as well as cultural and social values was assessed in bivariate analyses in a first step. Furthermore, odds ratios and adjusted odds ratios with 95% confidence intervals using a binary and multivariable logistic regression were calculated.
Results
Our research presents the trends of a composite measure of CoC including antenatal care, delivery assistance and postpartum care. The largest gap in CoC was observed at antenatal care followed by delivery and postnatal care within 48 h after delivery. Results show that CoC completion rate has increased from 15% to 27% amongst women in Pakistan over time from 2006 to 2012. Women with high age at first birth, having less number of children, with higher education, belonging to richest quintile, living in Sindh province and urban areas, having high autonomy and exposure to mass media were most likely to avail complete CoC.
Conclusions
The findings show that women in Pakistan still lack the CoC. This calls for attention to develop and implement tailored interventions, focusing on the needs of women in Pakistan to provide CoC in an integrated manner, involving both public and private sectors by appropriately addressing the factors hindering CoC completion rates
Reconstructing charge-carrier dynamics in porous silicon membranes from time-resolved interferometric measurements
We performed interferometric time-resolved simultaneous reflectance and transmittance measurements to investigate the carrier dynamics in pump-probe experiments on thin porous silicon membranes. The experimental data was analysed by using a method built on the Wentzel-Kramers-Brillouin approximation and the Drude model, allowing us to reconstruct the excited carriersâ non-uniform distribution in space and its evolution in time. The analysis revealed that the carrier dynamics in porous silicon, with ~50% porosity and native oxide chemistry, is governed by the Shockley-Read-Hall recombination process with a characteristic time constant of 375 picoseconds, whereas diffusion makes an insignificant contribution as it is suppressed by the high rate of scattering
Drivers of grassland loss in Hungary during the post-socialist transformation (1987â1999)
The increase in the speed of land-cover change experienced worldwide is becoming a growing
concern. Major socio-economic transitions, such as the breakdown of socialism in Europe, may
lead to particularly high rates of landscape transformations. In this paper we examined the loss of semi-natural grasslands in Hungary between 1987 and 1999. We studied the relationship between 9
potential driving forces and the fate of grasslands using logistic GLMs.
Grassland loss was found to be very high (1.31 % per year), which is far higher than either before
or after this period. The most influential predictors of grassland loss were environmental and
landscape characteristics (soil type, area of remnant grassland patches), and the socio-economic context (distance to paved road, and nearest settlement, human population density). Several
processes and relationships can only be understood from a historical perspective (e.g. large extent
of afforestation, strong decrease of soil water table). Grassland loss during the study period
emerged as a consequence of survival strategies of individual farmers seeking adaptation to the
changing environmental and socio-economic conditions, and not urbanization and agricultural intensification which are the main underlying drivers for the ongoing landscape transformations in
most parts of the developed world.
Though globalization increasingly influences local land use decisions , reconstructing and
modelling recent landscape changes cannot be done without a proper understanding of local history
and culture. Our analysis shows the importance of large-area yet high resolution landscape change research, which may reveal unexpected patterns of land cover change, undetected at coarser scales
Cervical Mucus Properties Stratify Risk for Preterm Birth
Background:
Ascending infection from the colonized vagina to the normally sterile intrauterine cavity is a well-documented cause of preterm birth. The primary physical barrier to microbial ascension is the cervical canal, which is filled with a dense and protective mucus plug. Despite its central role in separating the vaginal from the intrauterine tract, the barrier properties of cervical mucus have not been studied in preterm birth.
Methods and Findings:
To study the protective function of the cervical mucus in preterm birth we performed a pilot case-control study to measure the viscoelasticity and permeability properties of mucus obtained from pregnant women at high-risk and low-risk for preterm birth. Using extensional and shear rheology we found that cervical mucus from women at high-risk for preterm birth was more extensible and forms significantly weaker gels compared to cervical mucus from women at low-risk of preterm birth. Moreover, permeability measurements using fluorescent microbeads show that high-risk mucus was more permeable compared with low-risk mucus.
Conclusions:
Our findings suggest that critical biophysical barrier properties of cervical mucus in women at high-risk for preterm birth are compromised compared to women with healthy pregnancy. We hypothesize that impaired barrier properties of cervical mucus could contribute to increased rates of intrauterine infection seen in women with preterm birth. We furthermore suggest that a robust association of spinnbarkeit and preterm birth could be an effectively exploited biomarker for preterm birth prediction.Massachusetts Institute of Technology. Charles E. Reed Faculty Initiative FundBurroughs Wellcome Fund (Preterm Birth Research Grant)National Science Foundation (U.S.). Graduate Research Fellowship Progra
Micromechanical Properties of Injection-Molded StarchâWood Particle Composites
The micromechanical properties of injection molded starchâwood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starchâwood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
A computational model of lipopolysaccharide-induced nuclear factor kappa B activation:a key signalling pathway in infection-induced preterm labour
Preterm birth is the single biggest cause of significant neonatal morbidity and mortality, and the incidence is rising. Development of new therapies to treat and prevent preterm labour is seriously hampered by incomplete understanding of the molecular mechanisms that initiate labour at term and preterm. Computational modelling provides a new opportunity to improve this understanding. It is a useful tool in (i) identifying gaps in knowledge and informing future research, and (ii) providing the basis for an in silico model of parturition in which novel drugs to prevent or treat preterm labour can be "tested". Despite their merits, computational models are rarely used to study the molecular events initiating labour. Here, we present the first attempt to generate a dynamic kinetic model that has relevance to the molecular mechanisms of preterm labour. Using published data, we model an important candidate signalling pathway in infection-induced preterm labour: that of lipopolysaccharide (LPS) -induced activation of Nuclear Factor kappa B. This is the first model of this pathway to explicitly include molecular interactions upstream of Nuclear Factor kappa B activation. We produced a formalised graphical depiction of the pathway and built a kinetic model based on ordinary differential equations. The kinetic model accurately reproduced published in vitro time course plots of Lipopolysaccharide-induced Nuclear Factor kappa B activation in mouse embryo fibroblasts. In this preliminary work we have provided proof of concept that it is possible to build computational models of signalling pathways that are relevant to the regulation of labour, and suggest that models that are validated with wet-lab experiments have the potential to greatly benefit the field
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