3,341 research outputs found
Boundary Dissipation in a Driven Hard Disk System
A simulation is performed aiming at checking the existence of a well defined
stationary state for a two dimensional system of driven hard disks when energy
dissipation takes place at the system boundaries and no bulk impurities are
presentComment: 5 pages, 7 figure
Bulk dynamics for interfacial growth models
We study the influence of the bulk dynamics of a growing cluster of particles
on the properties of its interface. First, we define a {\it general bulk growth
model} by means of a continuum Master equation for the evolution of the bulk
density field. This general model just considers arbitrary addition of
particles (though it can be easily generalized to consider substraction) with
no other physical restriction. The corresponding Langevin equation for this
bulk density field is derived where the influence of the bulk dynamics is
explicitly shown. Finally, when it is assumed a well-defined interface for the
growing cluster, the Langevin equation for the height field of this interface
for some particular bulk dynamics is written. In particular, we obtain the
celebrated Kardar-Parisi-Zhang (KPZ) equation. A Monte Carlo simulation
illustrates the theoretical results.Comment: 6 pages, 2 figure
Is the particle current a relevant feature in driven lattice gases?
By performing extensive MonteCarlo simulations we show that the infinitely
fast driven lattice gas (IDLG) shares its critical properties with the randomly
driven lattice gas (RDLG).
All the measured exponents, scaling functions and amplitudes are the same in
both cases. This strongly supports the idea that the main relevant
non-equilibrium effect in driven lattice gases is the anisotropy (present in
both IDLG and RDLG) and not the particle current (present only in the IDLG).
This result, at odds with the predictions from the standard theory for the
IDLG, supports a recently proposed alternative theory. The case of finite
driving fields is also briefly discussed.Comment: 4 pages. Slightly improved version. Journal Reference: To appear in
Phys. Rev. Let
Evolving SPIDe Towards the Integration of Requirements Elicitation in Interaction Design
Among the various interaction (re)design processes and approaches, SPIDe is a semio-participatory
methodological process inspired by communication-centered design. However, the development of computational
solutions is not limited to interaction design. Requirements elicitation is also an integral part of this process. Some
SPIDe studies indicated that it is also possible to raise requirements through its application due to its participatory
characteristics. This article presents an investigation on the feasibility of SPIDe when applied to requirements elic itation integrated with interaction design, presenting an exploratory case study. From the perspective of different
experts, we explain the strengths and needs of SPIDe in supporting requirements elicitation integrated into inter action design. Data were collected through logbooks, semi-structured interviews, and the TAM questionnaire and
then analyzed through thematic analysis. The results show that the SPIDe use for requirements elicitation integrated
into the interaction design is feasible. Furthermore, they indicated that possible improvements in SPIDe could ben efit the development of the computational solutions considering a single application of SPIDe to obtain data for
interaction design and requirements elicitation integrated.info:eu-repo/semantics/publishedVersio
Inferring past refugia and range dynamics through the integration of fossil, niche modelling and genomic data
Aim: Reconstructing species' glacial refugial history and demographic changes over
time has greatly relied on comparing inferences from multiple methods while not sufficiently
acknowledging their limitations. Here, we aim to integrate as fully as possible
complementary methods in ecology, genomics and palaeobiology to improve the reconstruction
of species biogeographical history.
Location: South-western
Europe.
Taxon: Cabrera vole (Microtus cabrerae).
Methods: We compiled and mapped the raw fossil data of the Cabrera vole for the
Last Glacial Maximum (LGM) and Mid-Holocene
(MH). Alongside, we projected the
calibrated ecological niche model (ENM) of the species' current distribution for the
LGM, the Younger Dryas and the MH. Complementarily, we used previously obtained
Genotyping-by-
Sequencing
data to evaluate the demographic history and range expansion
patterns of all four Evolutionarily Significant Units of the species, in an integrative
framework. Results: ENM-inferred
refugial areas and genomic modelling consistently supported
northern Iberian glacial refugia for the Cabrera vole. This contrasted with the higher
fossil abundance of the species in southern and eastern Iberia and southern France
from the LGM to the MH. Our results suggest that populations in areas with high fossil
abundance went extinct, and were later replaced by northern Iberian populations
such that they did not contribute significantly to the current gene pool.
Main conclusions: Our integrative approach indicates how the range of the Cabrera
vole fluctuated in response to environmental change during and following the LGM.
Despite methodological limitations, the ENM and genomic approaches produced generally
congruent results. Instead, the fossil record may misrepresent the ancestral distribution
of this species and should be considered cautiously for ancestral distribution
reconstruction, considering that it also reflects the fossilization conditions. Overall,
our study supports the idea that integrative approaches are essential to provide an
accurate and well-supported
picture of historical refugial areas and range dynamicsinfo:eu-repo/semantics/publishedVersio
Aids, estigma e desemprego: implicações para os serviços de saúde
OBJECTIVE: To analyze the effect of the stigmatization and discrimination process in the work environment on the routine healthcare and well-being of men living with HIV/AIDS. METHODS: Qualitative study with 17 men living with HIV, conducted in 2002. Testimonies given in a group to discuss the difficulties concerning discrimination in the work environment were studied, by means of discursive practice analysis. The group, originating from a specialized center for HIV/AIDS treatment in the city of São Paulo, represented a segment of previous research. RESULTS: The discussion among participants pointed out the fact that antiretroviral treatment requires frequent visits to medical assistance services, resulting in absences and delays at work. To show medical certificates to justify absences at work, even without indicating AIDS, can lead to dismissal. Unemployed, many are barred during medical examinations and have their right to confidentiality violated. As a last resource, the request for retirement results in a humiliating or discriminatory scene during the medical inspection. CONCLUSIONS: Assistance planned with the patients' participation enables the broadening of psychosocial attention and the consideration of the needs of both employed and unemployed patients, acknowledging that the stigma limits care, affecting mental health and the evolution of infection. To reduce the effect of stigma and discrimination is something that requires intersectoral political articulation and will contribute to reach goals that are globally recognized as fundamental to control the epidemic.OBJETIVO: Analisar o efeito do processo de estigmatização e discriminação no ambiente de trabalho sobre os cuidados cotidianos à saúde e o bem-estar de homens vivendo com HIV/Aids. MÉTODOS: Estudo qualitativo com 17 homens vivendo com HIV, realizado em 2002. Foram estudados os depoimentos em grupo para discutir as dificuldades sobre discriminação no ambiente de trabalho, utilizando análise das práticas discursivas. O grupo, proveniente de centro especializado em HIV/Aids da cidade de São Paulo, representou segmento de pesquisa anterior. RESULTADOS: O debate entre os participantes indicou que o tratamento anti-retroviral exige idas freqüentes aos serviços de assistência médica, que implicam em faltas ou atrasos no trabalho. A apresentação de atestados médicos para justificar ausência no trabalho, mesmo sem indicar Aids, pode resultar em demissão. Desempregados, muitos são barrados nos exames médicos e têm o direito ao sigilo de sua condição violado. Como último recurso, o pedido de aposentadoria implica em cenas de humilhação ou discriminação na perÃcia médica. CONCLUSÕES: A assistência planejada com o envolvimento dos pacientes consegue ampliar a atenção psicossocial e considerar as necessidades do paciente trabalhador ou desempregado, reconhecendo que o estigma limita o cuidado, afetando a saúde mental e a evolução da infecção. Mitigar o efeito do estigma e da discriminação requer articulação polÃtica intersetorial e contribuirá para atingir metas globalmente reconhecidas como fundamentais para o controle da epidemia
Blood Phytosterol Concentration and Genetic Variant Associations in a Sample Population
The main objective of this study was to determine plasma levels of PS and to study SNVs rs41360247, rs4245791, rs4148217, and rs11887534 of ABCG8 and the r657152 SNV at the ABO blood group locus in a sample of a population treated at our hospital, and to determine whether these SNVs are related to plasma PS concentrations. The secondary objective was to establish the variables associated with plasma PS concentrations in adults. Participants completed a dietary habit questionnaire and a blood sample was collected to obtain the following variables: campesterol, sitosterol, sitostanol, lanosterol, stigmasterol, biochemical parameters, and the SNVs. In addition, biometric and demographic variables were also recorded. In the generalized linear model, cholesterol and age were positively associated with total PS levels, while BMI was negatively related. For rs4245791, homozygous T allele individuals showed a significantly lower campesterol concentration compared with C homozygotes, and the GG alleles of rs657152 had the lowest levels of campesterol compared with the other alleles of the SNV. Conclusions: The screening of certain SNVs could help prevent the increase in plasma PS and maybe PNALD in some patients. However, further studies on the determinants of plasma phytosterol concentrations are needed
Broadcast spawning coral <i>Mussismilia hispida</i> can vertically transfer its associated bacterial core
The hologenome theory of evolution (HTE), which is under fierce debate, presupposes that parts of the microbiome are transmitted from one generation to the next [vertical transmission (VT)], which may also influence the evolution of the holobiont. Even though bacteria have previously been described in early life stages of corals, these early life stages (larvae) could have been inoculated in the water and not inside the parental colony (through gametes) carrying the parental microbiome. How Symbiodinium is transmitted to offspring is also not clear, as only one study has described this mechanism in spawners. All other studies refer to incubators. To explore the VT hypothesis and the key components being transferred, colonies of the broadcast spawner species Mussismilia hispida were kept in nurseries until spawning. Gamete bundles, larvae and adult corals were analyzed to identify their associated microbiota with respect to composition and location. Symbiodinium and bacteria were detected by sequencing in gametes and coral planula larvae. However, no cells were detected using microscopy at the gamete stage, which could be related to the absence of those cells inside the oocytes/dispersed in the mucus or to a low resolution of our approach. A preliminary survey of Symbiodinium diversity indicated that parental colonies harbored Symbiodinium clades B, C and G, whereas only clade B was found in oocytes and planula larvae [5 days after fertilization (a.f.)]. The core bacterial populations found in the bundles, planula larvae and parental colonies were identified as members of the genera Burkholderia, Pseudomonas, Acinetobacter, Ralstonia, Inquilinus and Bacillus, suggesting that these populations could be vertically transferred through the mucus. The collective data suggest that spawner corals, such as M. hispida, can transmit Symbiodinium cells and the bacterial core to their offspring by a coral gamete (and that this gamete, with its bacterial load, is released into the water), supporting the HTE. However, more data are required to indicate the stability of the transmitted populations to indicate whether the holobiont can be considered a unit of natural selection or a symbiotic assemblage of independently evolving organisms
Current Fluctuations and Statistics During a Large Deviation Event in an Exactly-Solvable Transport Model
We study the distribution of the time-integrated current in an
exactly-solvable toy model of heat conduction, both analytically and
numerically. The simplicity of the model allows us to derive the full current
large deviation function and the system statistics during a large deviation
event. In this way we unveil a relation between system statistics at the end of
a large deviation event and for intermediate times. Midtime statistics is
independent of the sign of the current, a reflection of the time-reversal
symmetry of microscopic dynamics, while endtime statistics do depend on the
current sign, and also on its microscopic definition. We compare our exact
results with simulations based on the direct evaluation of large deviation
functions, analyzing the finite-size corrections of this simulation method and
deriving detailed bounds for its applicability. We also show how the
Gallavotti-Cohen fluctuation theorem can be used to determine the range of
validity of simulation results.Comment: 13 pages, 7 figures, published versio
Metabolic and Functional Profile of Premenopausal Women With Metabolic Syndrome After Training With Elastics as Compared to Free Weights
The aim of this study was to compare the effects of a strength training program (STP) using free weights (FW) versus elastic tubing (ET) in 62 premenopausal, sedentary women diagnosed with metabolic syndrome (MS). Participants were randomly assigned to the FW or ET experimental group (EG) or a control group whose members remained sedentary. Members of each EG followed their assigned STP for 12 weeks, and biomarkers (BMs) related to MS and motor function (MF) parameters were evaluated. Both EGs showed a significant reduction in C-reactive protein level and a positive trend in the other BMs. Almost all MF parameters increased significantly in both EGs. No positive changes were found in the CG. These results indicate that the implementation of an STP, with either FW or ET, improves both metabolic health and MF and should be considered part of the basic approach to health care in women
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