461 research outputs found
ANALYZING THE IMPACTS OF LAND COVER CHANGE TO THE HYDROLOGIC AND HYDRAULIC BEHAVIOURS OF THE PHILIPPINES' THIRD LARGEST RIVER BASIN
Changes in land cover can have negative impacts on the hydrological and hydraulic processes in river basins and watersheds such as increase in surface runoff and peak flows, and greater incidence, risk and vulnerability of flooding. In this study, the impacts of land-cover changes to the hydrologic and hydraulic behaviours of the Agusan River Basin (ARB), the third largest river basin in the Philippines, was analysed using an integrated approach involving Remote Sensing (RS), Geographic Information System (GIS), and hydrologic and hydraulic models. Different land-cover classes in the ARB for the years 1995 and 2017 were mapped using Landsat 5 TM and Landsat 8 OLI images. Using a post-classification change detection approach, changes in land-cover were then determined. The impacts of these changes in land-cover to the to the basin discharge were then estimated using a calibrated hydrologic model based on the Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS) under different extreme rainfall conditions. The impact of the changes in land-cover to flood depth and extent was also determined using a hydraulic model based on the HEC-RAS (River Analysis System). Land cover classification results revealed that the ARB is 67.7% forest in 1995 but have decreased to 62.8% in 2017. Agricultural areas in the basin were also found to have increased from 12.2% to 15.5% in the same period. Other notable land cover changes detected include the increase in built-up lands and range lands, and decrease in barren lands. HEC HMS and HEC RAS model simulation results showed that there was an increase in discharge, flood depth, and flood extents between 1995 and 2017, implying that that the detected changes in land cover have negative impacts to hydrologic and hydraulic behaviours of the ARB
The influence of fetal sex on patterns of change in anti-Mullerian hormone during pregnancy
Maternal anti-mullerian hormone declines sharply between 13-15 weeks, likely as a result of feto-placental signaling. Fetal AMH levels are known to be widely disparate after the first trimester, with high levels in male and absent levels in female. However, it is unclear as to whether differing fetal AMH levels influence the pattern of change of maternal AMH. Our objective was to examine AMH throughout gestation to determine if the maternal concentration varies according to the gender of the fetus
Effects of biological factors on the expression of arginine vasopressin receptors
Arginine vasopressin (AVP) is a hormone that functions to regulate blood pressure and bodily fluid homeostasis. Vasopressin has three main receptors AVPR1a, AVPR1b, and AVPR2 which were investigated in this project along with OXTR, LNPEP, and CUL5. AVPR1a functions in the smooth muscle and causes vasoconstriction, AVPR1b functions in the pituitary helping to regulate adrenocorticotropic hormone release, and AVPR2 is expressed highly in the kidneys and works to concentrate urine. This project investigates how these various receptors are expressed with different factors related to pregnancy such as, sex of the baby, chronically hypertensive mothers, and gestational age at deliver
NEAR-REAL TIME HAZARD MONITORING AND INFORMATION DISSEMINATION THROUGH INTEGRATION OF REMOTE SENSING, GIS, NUMERICAL MODELLING, WEB APPLICATIONS AND SOCIAL MEDIA
In mitigating and helping lessen the possible effects and damages of disaster to the communities, the transmission of information or end products derived from remote sensing and other multidisciplinary technologies into the community should be immediate, accessible and comprehensive to aid in better planning and decision-making procedures. In this paper, we share a hazard information dissemination procedure which integrates the use of outputs derived from numerical models, web applications and systems as well as the use of social media and telecommunications to promote the utilization of advanced science and technology outputs that could represent and visualize various flooding scenarios through social media and dynamic communication between stakeholders
The relationship between obesity, pregnancy, and levels of indoleamine 2,3-dioxygenase
For a successful pregnancy to occur, foreign genetic material such as the allogeneic fetus must be tolerated within the maternal host. Indoleamine 2,3-dioxygenase (IDO) is an enzyme induced by pro-inflammatory cytokines that has been shown to be key to this process. Obesity as a pro-inflammatory state is associated with poor obstetric outcomes. The primary objective of this study is to investigate the relationship between obesity and IDO activity
Complete Calabi-Yau metrics from Kahler metrics in D=4
In the present work the local form of certain Calabi-Yau metrics possessing a
local Hamiltonian Killing vector is described in terms of a single non linear
equation. The main assumptions are that the complex -form is of the form
, where is preserved by the Killing
vector, and that the space of the orbits of the Killing vector is, for fixed
value of the momentum map coordinate, a complex 4-manifold, in such a way that
the complex structure of the 4-manifold is part of the complex structure of the
complex 3-fold. The link with the solution generating techniques of [26]-[28]
is made explicit and in particular an example with holonomy exactly SU(3) is
found by use of the linearization of [26], which was found in the context of D6
branes wrapping a holomorphic 1-fold in a hyperkahler manifold. But the main
improvement of the present method, unlike the ones presented in [26]-[28], does
not rely in an initial hyperkahler structure. Additionally the complications
when dealing with non linear operators over the curved hyperkahler space are
avoided by use of this method.Comment: Version accepted for publication in Phys.Rev.
Evaluating the association of physical activity and weight gain in pregnancy
Previous research has shown that physical activity in pregnancy decreases the risk of poor pregnancy outcomes including development of gestational hypertension, pre-eclampsia, gestational diabetes, and the need for unplanned cesarean section. Research has also shown that excessive weight gain in pregnancy increases the risk of poor pregnancy outcomes. Tracking accurate physical activity in pregnancy is difficult using patient-reported data, however with commercially available and accurate physical activity monitors, objective data is more readily available. Our study is a feasibility study using objective data to track physical activity and weight gain in pregnancy
DNA methylation dynamics in a coastal foundation seagrass species under abiotic stressors
DNA methylation (DNAm) has been intensively studied in terrestrial plants in response to environmental changes, but its dynamic changes in a temporal scale remain unexplored in marine plants. The seagrass Posidonia oceanica ranks among the slowest-growing and longest-living plants on Earth, and is particularly vulnerable to sea warming and local anthropogenic pressures. Here, we analysed the dynamics of DNAm changes in plants collected from coastal areas differentially impacted by eutrophication (i.e. oligotrophic, Ol; eutrophic, Eu) and exposed to abiotic stressors (nutrients, temperature increase and their combination). Levels of global DNAm (% 5-mC) and the expression of key genes involved in DNAm were assessed after one, two and five weeks of exposure. Results revealed a clear differentiation between plants, depending on environmental stimuli, time of exposure and plants' origin. % 5-mC levels were higher during the initial stress exposure especially in Ol plants, which upregulated almost all genes involved in DNAm. Contrarily, Eu plants showed lower expression levels, which increased under chronic exposure to stressors, particularly to temperature. These findings show that DNAm is dynamic in P. oceanica during stress exposure and underlined that environmental epigenetic variations could be implicated in the regulation of acclimation and phenotypic differences depending on local conditions
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