8,988 research outputs found
Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Alewife/Blueback Herring
This profile covers life history
and environmental requirements of
both alewife (Alosa pseudoharengus)
and blueback herring (Alosa aestivalis),
since their distribution is
overlapping and their morphology,
ecological role, and environmental
requirements are similar.
The alewife is
an anadromous species found in
riverine, estuarine, and Atlantic
coastal habitats, depending on
life cycle stage, from Newfoundland
(Winters et al. 1973) to
Soutn Carolina (Berry 1964).
Landlocked populations are i n the
Great Lakes, Finger Lakes, and
many other freshwater lakes
(Bigelow and Sch roeder 1953;
Scott and Crossman 1973). The
blueback herring is an anadromous
species found in riverine,
estuarine, and Atlantic coastal
habitats, depending on life stage
cycle, from Nova Scotia to the
St. Johns River, Florida (Hildebrand
1963
Perivascular adipose tissue as a relevant fat depot for cardiovascular risk in obesity
Obesity is associated with increased risk of premature death, morbidity, and mortality from several cardiovascular diseases (CVDs), including stroke, coronary heart disease (CHD), myocardial infarction, and congestive heart failure. However, this is not a straightforward relationship. Although several studies have substantiated that obesity confers an independent and additive risk of all-cause and cardiovascular death, there is significant variability in these associations, with some lean individuals developing diseases and others remaining healthy despite severe obesity, the so-called metabolically healthy obese. Part of this variability has been attributed to the heterogeneity in both the distribution of body fat and the intrinsic properties of adipose tissue depots, including developmental origin, adipogenic and proliferative capacity, glucose and lipid metabolism, hormonal control, thermogenic ability, and vascularization. In obesity, these depot-specific differences translate into specific fat distribution patterns, which are closely associated with differential cardiometabolic risks. The adventitial fat layer, also known as perivascular adipose tissue (PVAT), is of major importance. Similar to the visceral adipose tissue, PVAT has a pathophysiological role in CVDs. PVAT influences vascular homeostasis by releasing numerous vasoactive factors, cytokines, and adipokines, which can readily target the underlying smooth muscle cell layers, regulating the vascular tone, distribution of blood flow, as well as angiogenesis, inflammatory processes, and redox status. In this review, we summarize the current knowledge and discuss the role of PVAT within the scope of adipose tissue as a major contributing factor to obesity-associated cardiovascular risk. Relevant clinical studies documenting the relationship between PVAT dysfunction and CVD with a focus on potential mechanisms by which PVAT contributes to obesity-related CVDs are pointed out
Maxwell-Chern-Simons vortices in a CPT-odd Lorentz-violating Higgs Electrodynamics
We have studied BPS vortices in a CPT-odd and Lorentz-violating
Maxwell-Chern-Simons-Higgs (MCSH) electrodynamics attained from the dimensional
reduction of the Carroll-Field-Jackiw-Higgs model. The Lorentz-violating
parameter induces a pronounced behavior at origin (for the magnetic/electric
fields and energy density) which is absent in the MCSH vortices. For some
combination of the Lorentz-violating coefficients there always exist a
sufficiently large winding number such that for all
the magnetic field flips its signal, yielding two well defined regions with
opposite magnetic flux. However, the total magnetic flux remains quantized and
proportional to the winding number.Comment: Revtex style, 8 page
Diabetic Foot Infection: Causative Pathogens and Empiric Antibiotherapy Considerations-The Experience of a Tertiary Center
Most moderate-to-severe diabetic foot infections (DFIs) require hospitalization with urgent surgical approach and administration of empiric antibiotherapy. To ensure optimal antibiotic coverage, regular microbiological background updates are imperative. The purpose is to characterize the microbiological profile and the antibiotic sensitivity pattern of the DFI causative pathogens isolated within a specialized DFI unit of a tertiary hospital, in order to establish evidence-based policies regarding empirical antibiotic use. A cross-sectional study was conducted. Microbiological cultures and corresponding antibiotic sensitivity tests collected from moderate-to-severe DFIs as a first approach to the hospitalized patient were retrieved and analyzed during a 12-month period. Two groups were analyzed: inpatients that had been previously followed at the diabetic foot clinic of the hospital and inpatients without a previous contact with the hospital services. A total of 125 isolates obtained from 87 patients were deemed for analysis. Globally, a predominance of Gram-positive bacteria was observed (60%). Staphylococcus aureus was the most common pathogen. The global ratio of methicillin-sensitive S aureus to methicillin-resistant S aureus (MRSA) was 1.3:1, with similar findings in both groups. According to the antibiotic sensitivity test results, and within the recommended empiric antibiotic regimens for DFI, piperacillin/tazobactam seems to be the most suitable option. Gram-positive bacteria prevail as the main isolates in DFIs. Screening for MRSA-specific risk factors is mandatory. When going for a first empiric therapy, piperacillin/tazobactam is recommended in this institution, and an anti-MRSA agent should be added early, if necessary. We encourage continuous monitoring for the bacterial prevalence in Portuguese diabetic foot centers as it is paramount for the decision making regarding DFI protocols.info:eu-repo/semantics/publishedVersio
Fever and Generalised Lymphadenopathy in an HIV-Positive Patient: a Diagnostic Challenge
Fever and generalised lymphadenopathy is a common presentation of a variety of diseases and a thorough investigation is often necessary for appropriate diagnosis.We present a 53-year-old male patient admitted with fever, weight loss of 15 kg in 3 months and abdominal discomfort. Examination was only remarkable for axillary and inguinal lymphadenopathy. Blood tests showed normocytic normochromic anaemia, cholestasis and a previously unknown HIV-1 infection with lymphocyte CD4 +count of 239 cells/mm(3) and viral load 3.172.370 copies/mL. A body CT scan showed multiple axillary, mediastinal, lumbar, aortic, iliac and pelvic lymphadenopathy as well as hepatosplenomegaly. An excisional biopsy of the left axillary lymphadenopathy was performed and histology ultimately revealed multicentric Castleman's disease associated with Human Herpes Virus-8. After initiation of antiretroviral therapy, rituximab was given and progressive clinical improvement occurred.info:eu-repo/semantics/publishedVersio
MODELLING OF HYDRODYNAMICS AROUND AN IMPERMEABLE BREAKWATER: COMPARISON BETWEEN PHYSICAL AND SPH NUMERICAL MODELING
This work presents the new developments and the validation of a Smoothed Particle Hydrodynamics (SPH) numerical model used in the National Laboratory of Civil Engineering (Laboratório Nacional de Engenharia Civil - LNEC) for studies in coastal engineering processes. Although the model requires a high CPU time, it proved to be very promising in the simulation of complex flows, such as the wave-structure interaction and the wave breaking phenomenon. For the SPH model validation, physical modeling tests were performed in one LNEC’s flume to study the interaction between an impermeable structure and an incident regular wave. The comparison between numerical and experimental results, i.e. free surface elevation, overtopping volume and pressure, shows the good accuracy of the SPH model to reproduce the various phenomena involving on the wave propagation and interaction with the structure, namely the wave breaking, the wave overtopping and the pressure field on the structure
The Effect of a positive cosmological constant on the bounce of Loop Quantum Cosmology
We provide an analytical solution to the quantum dynamics of a flat
Friedmann-Lema\^itre- Robertson-Walker model with a massless scalar field in
the presence of a small and positive cosmological constant, in the context of
Loop Quantum Cosmology. We use a perturbative treatment with respect to the
model without a cosmological constant, which is exactly solvable. Our solution
is approximate, but it is precisely valid at the high curvature regime where
quantum gravity corrections are important. We compute explicitly the evolution
of the expectation value of the volume. For semiclassical states characterized
by a Gaussian spectral profile, the introduction of a positive cosmological
constant displaces the bounce of the solvable model to lower volumes and to
higher values of the scalar field. These displacements are state dependent, and
in particular, they depend on the peak of the Gaussian profile, which measures
the momentum of the scalar field. Moreover, for those semiclassical states, the
bounce remains symmetric, as in the vanishing cosmological constant case.
However, we show that the behavior of the volume is more intricate for generic
states, leading in general to a non-symmetric bounce.Comment: 17 pages, 3 figures, v2: matches published versio
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