1,562 research outputs found
Environmental Response Management Application
The Coastal Response Research Center (CRRC), a partnership between the University of New Hampshire (UNH) and NOAA\u27s Office of Response and Restoration (ORR), is leading an effort to develop a data platform capable of interfacing both static and real-time data sets accessible simultaneously to a command post and assets in the field with an open source internet mapping server. The Environmental Response Management Application (ERMAâ„¢) is designed to give responders and decision makers ready access to geographically specific data useful during spill planning/drills, incident response, damage assessment and site restoration. In addition to oil spill and chemical release response, this website can be relevant to other environmental incidents and natural disasters, responses and regional planning efforts. The platform is easy to operate, without the assistance of Information Technology or Geographic Information Systems (GIS) specialists. It allows users to access individual data layer values, overlay relevant data sets, and zoom into segments of interest. The platform prototype is being developed specifically for Portsmouth Harbor and the Great Bay Estuary, NH. The prototype demonstrates the capabilities of an integrated data management platform and serves as the pilot for web-based GIS platforms in other regions
Barriers to family planning use in the Eastern Democratic Republic of the Congo: an application of the theory of planned behaviour using a longitudinal survey
OBJECTIVE: In the Democratic Republic of the Congo, there is a low adherence of the population to the use of family planning (FP) due to various social barriers. This study aimed to understand the drives from social barriers to the use of FP in women in the Kivu, a region particularly affected by poverty and many years of conflicts. A theory of planned behaviour (TPB) using a generalised structural equation modelling has been applied to understand the complex sociocultural drivers to the intention and the ultimate decision to use FP. DESIGN: Longitudinal study. SETTING: A community-based approach was used to investigate FP use in the North and South-Kivu regions. PARTICIPANTS: Overall, 1812 women 15 years and older were enrolled in the baseline study and 1055 were retrieved during the follow-up. PRIMARY AND SECONDARY OUTCOMES: FP use and intention to use FP. RESULTS: The mean age was 36+/-12.9 years, with a minimum of 15 years old and a maximum of 94 years old. Among sexually active participants, more than 40% used a modern contraceptive method at the last sexual intercourse. Education was positively and significantly associated with intention to use FP (beta=0.367; p=0.008). Being married was positively and marginally significantly associated with intention to use FP (beta=0.524: p=0.050). Subjective norms were negatively and significantly associated with intention to use FP (beta=-0.572; p=0.003) while perceived control was positively associated with intention to use FP (beta=0.578; p<0.0001). Education and perceived control were positively and significantly associated with the use of FP (respectively, beta=0.422, p=0.017; and beta=0.374; p=0.017), while Intention to use FP was positively and marginally significantly associated with the use of FP (beta=0.583; p=0.052). CONCLUSION: TPB helped understand sociocultural barriers to FP use and it can be useful to define adapted strategies in different contexts
CLASH: The Concentration-Mass Relation of Galaxy Clusters
We present a new determination of the concentration–mass (c–M) relation for galaxy clusters based on our
comprehensive lensing analysis of 19 X-ray selected galaxy clusters from the Cluster Lensing and Supernova
Survey with Hubble (CLASH). Our sample spans a redshift range between 0.19 and 0.89. We combine weak-lensing
constraints from the Hubble Space Telescope (HST) and from ground-based wide-field data with strong lensing constraints from HST. The results are reconstructions of the surface-mass density for all CLASH clusters on multi-scale grids. Our derivation of Navarro–Frenk–White parameters yields virial masses between
0.53 × 10^(15) M_⊙ h and 1.76 × 10^(15) M_⊙ h and the halo concentrations are distributed around c_(200c) ∼ 3.7 with a
1σ significant negative slope with cluster mass. We find an excellent 4% agreement in the median ratio of our
measured concentrations for each cluster and the respective expectation from numerical simulations after accounting for the CLASH selection function based on X-ray morphology. The simulations are analyzed in two dimensions to account for possible biases in the lensing reconstructions due to projection effects. The theoretical c–M relation from our X-ray selected set of simulated clusters and the c–M relation derived directly from the CLASH data agree at the 90% confidence level
Exposure to job-related violence among young female sex workers in urban slums of Southwest Nigeria
BACKGROUND: In Nigeria, many young girls are engaged in commercial sex work as a means of livelihood and support of dependent relatives. Although studies have documented some of the violence related issues among commercial sex workers, the plight of adolescent and young sex workers particularly in urban slums may be different in context and depth. OBJECTIVE: This study explored the lived experiences of violence and health related harm among vulnerable young female sex workers in urban slums in Ibadan and Lagos, Southwest Nigeria. It also analyzed their coping strategies and survival mechanisms. DESIGN: The study is cross-sectional and applied an interpretive phenomenological approach to this qualitative study through in-depth interviews. PARTICIPANTS: Young female sex workers ages (15-24 years) who reported having experienced violence were recruited for the study. Twelve participants completed the interviews out the 20 initially contacted. DATA COLLECTION AND ANALYSIS: Primary data were collected using in-depth interviews (IDIs). Data were transcribed using a phenomenological framework analysis. Participants' reports based on life experiences were identified: lived experience "daily brothel life experience"; sources of violence such as law enforcement agents' intermittent raids; violence experience with clients who often demanded sexual acts beyond the agreed scope; and coping strategies employed to mitigate the challenges. SETTINGS: The study was conducted in brothels of two selected slum areas in Ibadan and Lagos, Southwest Nigeria. RESULTS: The results showed that the major motivation for engaging in commercial sex work was for economic reasons. However, there are inherent risks involved particularly for the vulnerable young people. Stigmatization from the community, clients' uncontrolled-aggressive behavior and harassment from law enforcement agents are some of the frequent violence experiences reported. Self-help coping strategies are usually employed to prevent or mitigate the challenges. CONCLUSION: The plight of this young people required policy and program attention towards alternative economic empowerment to rehabilitate those willing to leave the profession. Also the need to develop arm reduction interventions towards protection of young sex workers against violence
Renegotiating cultural practices as a result of HIV in the eastern region of Malawi
A number of studies have shown that HIV awareness is very high among Malawians
and yet infection rates are rising. Local cultural practices have been identified as
contributing to this contradictory situation. Using data from 12 focus-group discussions
collected in Balaka, Zomba, Machinga and Mangochi, the paper explores the
reformulation of nine cultural practices as a preventive measure against HIV. The study
reveals that cultural practices that involve sexual acts for completion are mediated
through condoms and HIV tests. The study also shows that traditional herbs known for
healing ailments are repurposed to symbolise sexual acts. We conclude that the idea of
repurposing offers an avenue in which initiation and cleansing rites that involve sexual
acts are replaced by other semiotics such as a traditional medicine called mtela.
We also conclude that the modifications to cultural practices do not indicate complete
abandonment of associated traditions, rather, they constitute the renegotiation of
cultural practices and meanings associated with particular rites of passage. Lastly,
we propose that a comprehensive prevention programme needs to be part of a wider
national HIV-prevention effort combining a women and child rights and empowerment
agenda and, critically, lifestyle lessons in a process of cultural renegotiation.IBS
Concept of an efficient self-startup voltage converter with dynamic maximum power point tracking for microscale thermoelectric generators
Microscale Thermoelectric Generators (microTEGs) have a high application potential for energy harvesting for autonomous microsystems. In contrast to conventional thermoelectric generators, microTEGs can only supply small output-voltages. Therefore, voltage converters are required to provide supply-voltages that are sufficiently high to power microelectronics. However, for high conversion efficiency, voltage converters need to be optimized for the limited input voltage range and the typically high internal resistance of microTEGs. To overcome the limitations of conventional voltage converters we present an optimized self-startup voltage converter with dynamic maximum power point tracking. The performance potential of our concept is theoretically and experimentally analyzed. The voltage conversion interface demonstrates energy harvesting from open-circuit voltages as low as 30.7 mV, and enables independent and full start-up from 131 mV. No additional external power supply is required at any time during operation. It can be operated with a wide range of internal resistances from 20.6 to − 4 kΩ with a conversation efficiency between η = 68–79%
The MUSIC of CLASH: Predictions on the Concentration-Mass Relation
We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ~11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61
Reconstruction of the two-dimensional gravitational potential of galaxy clusters from X-ray and Sunyaev-Zel'dovich measurements
The mass of galaxy clusters is not a direct observable, nonetheless it is
commonly used to probe cosmological models. Based on the combination of all
main cluster observables, that is, the X-ray emission, the thermal
Sunyaev-Zel'dovich (SZ) signal, the velocity dispersion of the cluster
galaxies, and gravitational lensing, the gravitational potential of galaxy
clusters can be jointly reconstructed. We derive the two main ingredients
required for this joint reconstruction: the potentials individually
reconstructed from the observables and their covariance matrices, which act as
a weight in the joint reconstruction. We show here the method to derive these
quantities. The result of the joint reconstruction applied to a real cluster
will be discussed in a forthcoming paper. We apply the Richardson-Lucy
deprojection algorithm to data on a two-dimensional (2D) grid. We first test
the 2D deprojection algorithm on a -profile. Assuming hydrostatic
equilibrium, we further reconstruct the gravitational potential of a simulated
galaxy cluster based on synthetic SZ and X-ray data. We then reconstruct the
projected gravitational potential of the massive and dynamically active cluster
Abell 2142, based on the X-ray observations collected with XMM-Newton and the
SZ observations from the Planck satellite. Finally, we compute the covariance
matrix of the projected reconstructed potential of the cluster Abell 2142 based
on the X-ray measurements collected with XMM-Newton. The gravitational
potentials of the simulated cluster recovered from synthetic X-ray and SZ data
are consistent, even though the potential reconstructed from X-rays shows
larger deviations from the true potential. Regarding Abell 2142, the projected
gravitational cluster potentials recovered from SZ and X-ray data reproduce
well the projected potential inferred from gravitational-lensing observations.
(abridged)Comment: accepted for publication in the journal A&
Quark-antiquark composite systems: the Bethe-Salpeter equation in the spectral-integration technique
The Bethe-Salpeter equations for the light-quark composite systems, q q-bar,
are written in terms of spectral integrals. For the q q-bar -mesons
characterized by the mass M, spin J and radial quantum number n, the equations
are presented for the following (n,M^2)-trajectories: pi_J, eta_J, a_J, f_J,
rho_J, omega_J, h_J and b_J.Comment: 42 pages, 5 figures, typos correcte
Multiple spatially localized dynamical states in friction-excited oscillator chains
International audienceFriction-induced vibrations are known to affect many engineering applications. Here, we study a chain of friction-excited oscillators with nearest neighbor elastic coupling. The excitation is provided by a moving belt which moves at a certain velocity v d while friction is modelled with an exponentially decaying friction law. It is shown that in a certain range of driving velocities, multiple stable spatially localized solutions exist whose dynamical behavior (i.e. regular or irregular) depends on the number of oscillators involved in the vibration. The classical non-repeatability of friction-induced vibration problems can be interpreted in light of those multiple stable dynamical states. These states are found within a "snaking-like" bifurcation pattern. Contrary to the classical Anderson localization phenomenon, here the underlying linear system is perfectly homogeneous and localization is solely triggered by the friction nonlinearity
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