726 research outputs found
Does the CEO elite education affect firm hedging policies?
This paper studies the relationship between CEO elite education and firm hedging decisions. It uses the particular specificities of the French post-secondary educational institutions to examine the effect of CEO educational background on the use of foreign currency derivatives. The results show a positive and significant relationship between education quality and derivatives use. Neither the level nor the type of education has any significant effect. The results also show that the use of derivatives enhances firm performance only when CEOs are from elite institutions. These results are robust to a battery of tests that involve alternative estimation techniques, the use of different subsamples, additional control variables, and control for endogeneity and selection bias
SU(5) grand unification on a domain-wall brane from an E_6-invariant action
An SU(5) grand unification scheme for effective 3+1-dimensional fields
dynamically localised on a domain-wall brane is constructed. This is achieved
through the confluence of the clash-of-symmetries mechanism for symmetry
breaking through domain-wall formation, and the Dvali-Shifman gauge-boson
localisation idea. It requires an E_6 gauge-invariant action, yielding a
domain-wall solution that has E_6 broken to differently embedded SO(10) x U(1)
subgroups in the two bulk regions on opposite sides of the wall. On the wall
itself, the unbroken symmetry is the intersection of the two bulk subgroups,
and contains SU(5). A 4+1-dimensional fermion family in the 27 of E_6 gives
rise to localised left-handed zero-modes in the 5^* + 10 + 1 + 1 representation
of SU(5). The remaining ten fermion components of the 27 are delocalised exotic
states, not appearing in the effective 3+1-dimensional theory on the
domain-wall brane. The scheme is compatible with the type-2 Randall-Sundrum
mechanism for graviton localisation; the single extra dimension is infinite.Comment: 21 pages, 9 figures. Minor changes to text and references. To appear
in Phys. Rev.
Wasting and associated factors among children under 5 years in five South Asian countries (2014-2018) : analysis of demographic health surveys
Child wasting continues to be a major public health concern in South Asia, having a prevalence above the emergency threshold. This paper aimed to identify factors associated with wasting among children aged 0–23 months, 24–59 months, and 0–59 months in South Asia. A weighted sample of 564,518 children aged 0–59 months from the most recent demographic and health surveys (2014–2018) of five countries in South Asia was combined. Multiple logistic regression analyses that adjusted for clustering and sampling weights were used to examine associated factors. Wasting prevalence was higher for children aged 0–23 months (25%) as compared to 24–59 months (18%), with variations in prevalence across the South Asian countries. The most common factor associated with child wasting was maternal BMI [adjusted odds ratio (AOR) for 0–23 months = 2.02; 95% CI: (1.52, 2.68); AOR for 24–59 months = 2.54; 95% CI: (1.83, 3.54); AOR for 0–59 months = 2.18; 95% CI: (1.72, 2.77)]. Other factors included maternal height and age, household wealth index, birth interval and order, children born at home, and access to antenatal visits. Study findings suggest need for nutrition specific and sensitive interventions focused on women, as well as adolescents and children under 2 years of age
Factors associated with stunting among children under 5 years in five South Asian countries (2014-2018) : analysis of Demographic Health Surveys
South Asia continues to be the global hub for child undernutrition with 35% of children still stunted in 2017. This paper aimed to identify factors associated with stunting among children aged 0–23 months, 24–59 months, and 0–59 months in South Asia. A weighted sample of 564,518 children aged 0–59 months from the most recent Demographic and Health Surveys (2014–2018) was combined of five countries in South Asia. Multiple logistic regression analyses that adjusted for clustering and sampling weights were used to examine associated factors. The common factors associated with stunting in three age groups were mothers with no schooling ([adjusted odds ratio (AOR) for 0–23 months = 1.65; 95% CI: (1.29, 2.13)]; [AOR for 24–59 months = AOR = 1.46; 95% CI: (1.27, 1.69)] and [AOR for 0–59 months = AOR = 1.59; 95% CI: (1.34, 1. 88)]) and maternal short stature (height < 150 cm) ([AOR for 0–23 months = 2.00; 95% CI: (1.51, 2.65)]; [AOR for 24–59 months = 3.63; 95% CI: (2.87, 4.60)] and [AOR for 0–59 months = 2.87; 95% CI: (2.37, 3.48)]). Study findings suggest the need for a balanced and integrated nutrition strategy that incorporates nutrition-specific and nutrition-sensitive interventions with an increased focus on interventions for children aged 24–59 months
Past drivers of and priorities for child undernutrition in South Asia : a mixed methods systematic review protocol
BACKGROUND: South Asia has one of the largest proportions of undernourished children in the world, especially stunting, wasting, and underweight as well as micronutrient deficiencies such as the deficiency of iron, vitamin A, and zinc. Undernutrition continues to pose a major threat to this region's economic and social growth. This systematic review aims to assess the drivers and identify priorities for child undernutrition in South Asia. It aims to appraise, synthesise, and summarise literature to create an evidence base that looks at multiple faces of macro and micro child undernutrition in South Asia. METHODS: A systematic review of published and grey literature on child undernutrition, including macro and micronutrient deficiencies, in South Asia covering the period January 2000 to September 2019 will be undertaken. Studies with all relevant study designs and those published in English will be considered for inclusion. Five academic databases will be searched: CINAHL, EMBASE, PubMed, PsycINFO, and Scopus, in addition to various grey literature sources. The analysis will incorporate a narrative synthesis, meta-ethnography or a meta-analysis as appropriate, depending on the nature of the retrieved data. Quality of the included studies will be assessed by validated tools. The UNICEF conceptual framework on child undernutrition will be used to frame findings. DISCUSSION: This protocol is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines. The protocol gives an insight into the scope and parameters for the systematic review to be carried out. SYSTEMATIC REVIEW REGISTRATION: The protocol was registered by the PROSPERO international prospective register of systematic reviews, reference CRD42018112696
SALTWATER – FRESHWATER WETLAND ECOSYSTEM AND URBAN LAND USE CHANGE IN PORT HARCOURT METROPOLIS, NIGERIA
Urban development in wetland ecosystems for human settlement, transport networks, exploration /exploitation of
natural resources, agriculture and industrial development is one of the biggest menace to wetland change and
management. To estimate future urban expansion is very crucial for urban planners and environmental managers in
fastest growing cities. This study aims to examine the saltwater/freshwater ecosystem and urban land use change in
Port Harcourt metropolis, Nigeria. Sources of data for this study were acquired from a time series of landsat Thematic
Mapper (TM) and Enhanced Thematic Mapper plus (ETM+) with Thermal Infrared Sensor (TIRS) images were used to
derive land use and land cover maps of the Port-Harcourt metropolis. This study revealed that both freshwater wetland
and saltwater wetlands ecosystem occupied 46.99% (18837.1 Ha) of the total classes. This may be the result of wetland
being in an undisturbed nature without any conversion or alteration for use. The urban land use change of PortHarcourt metropolis had changed dramatically during the period of 29 years. The two wetlands (saltwater and
freshwater wetland) sum up to a total of 40% (16497.5 Ha) which indicates that there is pressure on wetland use such
as plant products harvested from fuel wood, human settlement, urban agriculture, sand dredging, sanitation, water
pollution and industrial activities from oil companies within the metropolis. Efforts should be made to increase
knowledge, sensitization, consultation, stakeholder’s participation and awareness on the wetlands values and wise use
economy through dissemination of information, using appropriate techniques and training of adequate staff as well as
the need for sound wetland policies, laws and legislation for sustainable use, management and control in conservation
of wetland
The gene regulatory basis of genetic compensation during neural crest induction.
The neural crest (NC) is a vertebrate-specific cell type that contributes to a wide range of different tissues across all three germ layers. The gene regulatory network (GRN) responsible for the formation of neural crest is conserved across vertebrates. Central to the induction of the NC GRN are AP-2 and SoxE transcription factors. NC induction robustness is ensured through the ability of some of these transcription factors to compensate loss of function of gene family members. However the gene regulatory events underlying compensation are poorly understood. We have used gene knockout and RNA sequencing strategies to dissect NC induction and compensation in zebrafish. We genetically ablate the NC using double mutants of tfap2a;tfap2c or remove specific subsets of the NC with sox10 and mitfa knockouts and characterise genome-wide gene expression levels across multiple time points. We find that compensation through a single wild-type allele of tfap2c is capable of maintaining early NC induction and differentiation in the absence of tfap2a function, but many target genes have abnormal expression levels and therefore show sensitivity to the reduced tfap2 dosage. This separation of morphological and molecular phenotypes identifies a core set of genes required for early NC development. We also identify the 15 somites stage as the peak of the molecular phenotype which strongly diminishes at 24 hpf even as the morphological phenotype becomes more apparent. Using gene knockouts, we associate previously uncharacterised genes with pigment cell development and establish a role for maternal Hippo signalling in melanocyte differentiation. This work extends and refines the NC GRN while also uncovering the transcriptional basis of genetic compensation via paralogues
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Associations of walkability, regional and transit accessibility around home and workplace with active and sedentary travel
Few studies have simultaneously examined whether the neighborhood built environment near work is independently associated with active versus sedentary travel. We investigate the associations of objectively assessed built environment and regional/transit accessibility around home and work locations with active (walking, biking) and sedentary (auto-use) transportation while controlling for attitudinal predispositions, perceptions, and demographic factors. Baseline data from 2012 to 2013 on a sample of 648 participants in the Rails & Health study based in Portland, Oregon were analyzed. Data about active and sedentary travel outcomes, attitudes, perceptions, and demographics were derived from a survey. Road network buffers (with a 1 km range) around each of the home and work locations were used to create detailed measures of walkability, natural environment, regional and transit accessibility. Log-linear and log-linear Tobit regression models tested associations of home and worksite neighborhood features with weekly amount of walking, biking, and auto use. Significant differences in walkability, regional accessibility, and natural environment between home and workplaces were observed. Independent of walkability around home, a one-unit increase in walkability index around work was correlated with a 2.8% [90% CI: 0.5% - 4.9%] and 2.7% [90% CI: 0.5% - 4.8%] higher weekly duration of biking and walking, respectively. Greater walkability around workplace was associated with lower time spent in automobiles. Greater regional and transit accessibility around work was correlated with higher walking/biking and lower automobile travel. The study highlights the important role of more walkable, connected, denser, and diverse workplace environments in enhancing public health
Heating up the cold bounce
Self-dual string cosmological models provide an effective example of bouncing
solutions where a phase of accelerated contraction smoothly evolves into an
epoch of decelerated Friedmann--Robertson--Walker expansion dominated by the
dilaton. While the transition to the expanding regime occurs at sub-Planckian
curvature scales, the Universe emerging after the bounce is cold, with sharply
growing gauge coupling. However, since massless gauge bosons (as well as other
massless fields) are super-adiabatically amplified, the energy density of the
maximally amplified modes re-entering the horizon after the bounce can
efficiently heat the Universe. As a consequence the gauge coupling reaches a
constant value, which can still be perturbative.Comment: 28 pages, 13 figure
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