510 research outputs found
Local solvability and turning for the inhomogeneous Muskat problem
In this work we study the evolution of the free boundary between two different fluids in a porous medium where the permeability is a two dimensional step function. The medium can fill the whole plane R^2 or a bounded strip S=RX(-pi/2,pi/2). The system is in the stable regime if the denser fluid is below the lighter one. First, we show local existence in Sobolev spaces by means of energy method when the system is in the stable regime. Then we prove the existence of curves such that they start in the stable regime and in finite time they reach the unstable one. This change of regime (turning) was first proven in [5] for the homogenous Muskat problem with infinite depth
Models for damped water wave
In this paper we derive some new weakly nonlinear asymptotic models describing viscous waves in deep water with or without surface tension effects. These asymptotic models take into account several different dissipative effects and are obtained from the free boundary problems formulated in the works of Dias, Dyachenko, and Zakharov [Phys. Lett. A, 372 (2008), pp. 1297--1302], Jiang et al. [J. Fluid Mech., 329 (1996), pp. 275--307], and Wu, Liu and Yue [J. Fluid Mech., 556 (2006), pp. 45--54].The work of the second author was supported by the Basque Government through the BERC 2018-2021 program and by Spanish Ministry of Economy and Competitiveness MINECO through BCAM Severo Ochoa excellence accreditation SEV-2017-0718 and through project MTM2017-82184-R funded by (AEI/FEDER, UE) and acronym “DESFLU.
Sexuality throughout all the stages of pregnancy: experiences of expectant mothers
Objective: To explore and understand the sexual experiences of expectant mothers during their pregnancy.
Methods: The study was carried out in two healthcare centers in the Almería Health District, in southern Spain. The participants included pregnant women who received prenatal care and/or maternity education. The inclusion criteria were being pregnant, maintaining sexual activity and agreeing to participate in the study. The exclusion criteria were having limitations on sexual activity by medical prescription. The sample consisted of 15 expectant women selected using a convenience sample, of which 5 took part in a focus group (FG) and 10 in in-depth interviews (IDI). Data was collected between the months of June and December 2016. Participants were contacted by the main researcher and an appointment was made to carry out the FGs or the IDIs.
Results: Three main categories emerged: False beliefs and a holistic approach to sexuality during pregnancy, which is related to the concept of sexuality, false beliefs, and limited sexual counseling during pregnancy. Limitations: From fear at the beginning to physical diffi culty at the end, referring to the fluctuations in sexual desire as well as the physical changes that limit sexual activity. Adapting to changes: safe practices and satisfaction with one’s body image, which encompasses concerns about the risks and the relationship between body image and self-esteem.
Conclusion: A lack of sexual counseling during pregnancy leads to the creation of false beliefs, which, together with physical changes, concerns about the risk, and fl uctuations in sexual desire and interest, bring about a decrease in sexual activity. But sexuality remains an important aspect of pregnancy, toward which the participants must adopt a broader approach, not limited to intercourse, and adopt sexual practices that are adapted to the physical and emotional changes that happen during this time
Resilience of small-scale societies’ livelihoods: a framework for studying the transition from food gathering to food production
The origins of agriculture and the shift from hunting and gathering to committed agriculture is regarded as one of the major transitions in human history. Archeologists and anthropologists have invested significant efforts in explaining the origins of agriculture. A period of gathering intensification and experimentation and pursuing a mixed economic strategy seems the most plausible explanation for the transition to agriculture and provides an approach to study a process in which several nonlinear processes may have played a role. However, the mechanisms underlying the transition to full agriculture are not completely clear. This is partly due to the nature of the archeological record, which registers a practice only once it has become clearly established. Thus, points of transitions have limited visibility and the mechanisms involved in the process are difficult to untangle. The complexity of such transitions also implies that shifts can be distinctively different in particular environments and under varying historical and social conditions. In this paper we discuss some of the elements involved in the transition to food production within the framework of resilience theory. We propose a theoretical conceptual model in which the resilience of livelihood strategies lies at the intersection of three spheres: the environmental, economical, and social domains. Transitions occur when the rate of change, in one or more of these domains, is so elevated or its magnitude so large that the livelihood system is unable to bounce back to its original state. In this situation, the system moves to an alternative stable state, from one livelihood strategy to another.This paper is the result of a two-day workshop funded by ICREA (Catalan Higher Research Institution) and organized at the ICTA (Institute for Environmental Studies) of the Autonomous University of Barcelona and the Department of Humanities of the Universitat Pompeu Fabra. The workshop was cofounded by the SimulPast project (former Spanish Ministry of Science and Innovation, CSD2010-00034). CL, DZ, MM, and JJGG are part of CaSEs (Complexity and Socio-Ecological Dynamics Research Group), a Grup de Recerca Emergent of the Generalitat de Catalunya (SGR-e 1417). CL is currently a UPFellow; JJGG was supported by a JAE PreDOC PhD scholarship (Spanish National Research Council and European Social Fund) and the SimulPast project.Peer Reviewe
Drone Applications for Emergency and Urgent Care: A Systematic Review
Introduction: In recent years, the use of drones in health emergencies has increased. Among
their main benefits are avoiding endangering rescuers, travelling long distances in a short
time, or contacting victims in risky situations; but despite their multiple advantages, their
use has not been fully demonstrated.
Study Objective: This study aims to identify the available evidence on the use of drones in
emergency health care compared to traditional health care.
Methods: Systematic review of the literature was conducted. Search protocols were developed
to locate studies that met the established selection criteria. Six experimental or quasiexperimental
studies with high methodological quality published from the beginning of
indexing until 2020 were included.
Results: Drones covered a significantly larger area than other traditional tracking methods
and were very useful for performing preliminary triage, determining needs, and knowing the
scene prior to the arrival of rescuers. In addition, drones reduced the time required to locate
the victim.
Conclusions: Drones are an element to be taken into account when attending health emergencies
as they significantly improve the distance travelled to locate accident victims, have
the possibility of performing triage prior to the arrival of the health care units, and improve
the time and quality of the care provided
Development of the Aerial Remote Triage System: Result of a survey of international expert
The use of drones for triage in mass-casualty incidents has recently emerged as a promising
technology. However, there is no triage system specifically adapted to a remote usage. Our
study aimed to develop a remote triage procedure using drones. The research was performed
in three stages: literature review, the development of a remote triage algorithm using
drones and evaluation of the algorithm by experts. Qualitative synthesis and the calculation
of content validity ratios were done to achieve the Aerial Remote Triage System. This algorithm
assesses (in this order): major bleeding, walking, consciousness and signs of life; and
then classify the injured people into several priority categories: priority 1 (red), priority 2 (yellow),
priority 3 (green) and priority * (violet). It includes the possibility to indicate save-living
interventions to injured people and bystanders, like the compression of bleeding injuries or
the adoption of the recovery position. The Aerial Remote Triage System may be a useful
way to perform triage by drone in complex emergencies when it is difficult to access to the
scene due to physical, chemical or biological risks
AmrZ is a major determinant of c-di-GMP levels in Pseudomonas fluorescens F113
The transcriptional regulator AmrZ is a global regulatory protein conserved within the pseudomonads. AmrZ can act both as a positive and a negative regulator of gene expression, controlling many genes implicated in environmental adaption. Regulated traits include motility, iron homeostasis, exopolysaccharides production and the ability to form biofilms. In Pseudomonas fluorescens F113, an amrZ mutant presents a pleiotropic phenotype, showing increased swimming motility, decreased biofilm formation and very limited ability for competitive colonization of rhizosphere, its natural habitat. It also shows different colony morphology and binding of the dye Congo Red. The amrZ mutant presents severely reduced levels of the messenger molecule cyclic-di-GMP (c-di-GMP), which is consistent with the motility and biofilm formation phenotypes. Most of the genes encoding proteins with diguanylate cyclase (DGCs) or phosphodiesterase (PDEs) domains, implicated in c-di-GMP turnover in this bacterium, appear to be regulated by AmrZ. Phenotypic analysis of eight mutants in genes shown to be directly regulated by AmrZ and encoding c-di-GMP related enzymes, showed that seven of them were altered in motility and/or biofilm formation. The results presented here show that in P. fluorescens, AmrZ determines c-di-GMP levels through the regulation of a complex network of genes encoding DGCs and PDEs
The efficacy of a web-based gambling intervention program for high school students: A preliminary randomized study
Early onset in adolescent gambling involvement can be a precipitator of later gambling problems. The aim of the present study was to test the preliminary efficacy of a web-based gambling intervention program for students within a high school-based setting. Students attending a high school in Italy (N=168) participated in the present study (58% male–age, M=15.01; SD=0.60). Twelve classes were randomly assigned to one of two conditions: intervention ( N=6; 95 students) and control group (N=6; 73 students). Both groups received personalized feedback and then the intervention group received online training (interactive activities) for three weeks. At a two-month follow-up, students in the intervention group reported a reduction in gambling problems relative to those in the control group. However, there were no differences in gambling frequency, gambling expenditure, and attitudes toward the profitability of gambling between the two groups. In addition, frequent gamblers (i.e., those that gambled at least once a week at baseline) showed reductions in gambling problems and gambling frequency post- intervention. Frequent gamblers that only received personalized feedback showed significantly less realistic attitudes toward the profitability of gambling post-intervention. The present study is the first controlled study to test the preliminary efficacy of a web-based gambling intervention program for students within a high school-based setting. The results indicate that a brief web-based intervention delivered in the school setting may be a potentially promising strategy for a low-threshold, low-cost, preventive tool for at-risk gambling high school students
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