622 research outputs found
Análises morfométricas entre apis mellifera da mesorregiao do sertao paraibano
Objetivou-se, com esse trabalho, caracterizar as populações de Apis mellifera da mesorregião do Sertão paraibano, comparando os indivíduos morfometricamente. As medidas tomadas foram: comprimento da asa anterior (CAA) e largura da asa anterior (LAA), ângulos B4, E9, G18, J16, K19, N23, O26 e distância b (Db); comprimento da asa posterior (CAP) e largura da asa posterior (LAP), distância L2 (DL2), L5 (DL5) e ângulo W3, comprimento do fêmur (CF), comprimento da tíbia (CT), comprimento do tarso (CTS) e largura do tarso (LTS) e comprimento da probóscide (CP). Para a comparação das diferentes variáveis estudadas utilizou-se a análise de variância, o teste de Tukey, análise canônica e o teste de Tocher a 5% de significância. Para as medidas realizadas em cada amostra utilizou-se um equipamento de análise de imagens, Programa Image Pro Plus 4.0. As variáveis CTS e LTS, ângulos G18 e K19 e DL2 diferiram significativamente (p<0,05) entre as localidades estudadas de acordo com o teste de Tukey. A análise canônica mostrou a existência de um agrupamento com base nas características morfológicas entre duas das localidades estudadas apesar da distância geográfica. Concluiu-se que existem dois grupos distintos morfometricamente para a microrregião estudada e que há um processo adaptativo das abelhas, quanto às medidas morfométricas, para as diferentes regiões geomorfológicas
Tuberculosis vaccine candidates based on mycobacterial cell envelope components
Even after decades searching for a new and more effective vaccine against tuberculosis, the scientific community is still pursuing this goal due to the complexity of its causative agent, Mycobacterium tuberculosis (Mtb). Mtb is a microorganism with a robust variety of survival mechanisms that allow it to remain in the host for years. The structure and nature of the Mtb envelope play a leading role in its resistance and survival. Mtb has a perfect machinery that allows it to modulate the immune response in its favor and to adapt to the host's environmental conditions in order to remain alive until the moment to reactivate its normal growing state. Mtb cell envelope protein, carbohydrate and lipid components have been the subject of interest for developing new vaccines because most of them are responsible for the pathogenicity and virulence of the bacteria. Many indirect evidences, mainly derived from the use of monoclonal antibodies, support the potential protective role of Mtb envelope components. Subunit and DNA vaccines, lipid extracts, liposomes and membrane vesicle formulations are some examples of technologies used, with encouraging results, to evaluate the potential of these antigens in the protective response against Mtb.Fil: Sarmiento, M.E.. Universiti Sains Malaysia; MalasiaFil: Alvarez, N.. Public Health Research Institute; Estados UnidosFil: Chin, K.L.. Universiti Sains Malaysia; MalasiaFil: Bigi, Fabiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Tirado, Y.. No especifíca;Fil: García, M.A.. No especifíca;Fil: Anis, F.Z.. Universiti Sains Malaysia; MalasiaFil: Norazmi, M.N.. Universiti Sains Malaysia; MalasiaFil: Acosta, A.. Universiti Sains Malaysia; Malasi
A Theory of a Spot
We present a simple inflationary scenario that can produce arbitrarily large
spherical underdense or overdense regions embedded in a standard Lambda cold
dark matter paradigm, which we refer to as bubbles. We analyze the effect such
bubbles would have on the Cosmic Microwave Background (CMB). For super-horizon
sized bubble in the vicinity of the last scattering surface, a signal is
imprinted onto CMB via a combination of Sach-Wolfe and an early integrated
Sach-Wolfe (ISW) effects. Smaller, sub-horizon sized bubbles at lower redshifts
(during matter domination and later) can imprint secondary anisotropies on the
CMB via Rees-Sciama, late-time ISW and Ostriker-Vishniac effects. Our scenario,
and arguably most similar inflationary models, produce bubbles which are
over/underdense in potential: in density such bubbles are characterized by
having a distinct wall with the interior staying at the cosmic mean density. We
show that such models can potentially, with only moderate fine tuning, explain
the \emph{cold spot}, a non-Gaussian feature identified in the Wilkinson
Microwave Anisotropy Probe (WMAP) data by several authors. However, more
detailed comparisons with current and future CMB data are necessary to confirm
(or rule out) this scenario.Comment: 19 pages, 19 figures, added references and explanations, JCAP in
pres
The association of Step-based metrics and adiposity in the Hispanic community Health Study/Study of Latinos
Objective: Examine cross-sectional and longitudinal associations of accelerometer measured step volume (steps/day) and cadence with adiposity and six-year changes in adiposity in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Methods: HCHS/SOL's target population was 60% female with a mean age of 41 years. Cross-sectional (n = 12,353) and longitudinal analyses (n = 9,077) leveraged adjusted complex survey regression models to examine associations between steps/day, and cadence with weight (kg), waist circumference (cm) and body mass index (kg/m2). Effect measure modification by covariates was examined. Results: Lower steps/day and intensity was associated with higher adiposity at baseline. Compared to those in the highest quartile of steps/day those in the lowest quartile have 1.42 95% CI (1.19, 1.70) times the odds of obesity. Compared to those in the highest categories of cadence step-based metrics, those in the lowest categories had a 1.62 95% CI (1.36, 1.93), 2.12 95% CI (1.63, 2.75) and 1.41 95% CI (1.16, 1.70) odds of obesity for peak 30-minute cadence, brisk walking and faster ambulation and bouts of purposeful steps and faster ambulation, respectively. Compared to those with the highest stepping cadences, those with the slowest peak 30-minute cadence and fewest minutes in bouts of purposeful steps and faster ambulation had 0.72 95% CI (0.57, 0.89) and 0.82 95% CI (0.60, 1.14) times the odds of gaining weight, respectively. Conclusion: Inverse cross-sectional relationships were found for steps/day and cadence and adiposity. Over a six-year period, higher step intensity but not volume was associated with higher odds of gaining weight
Theory and phenomenology of two-Higgs-doublet models
We discuss theoretical and phenomenological aspects of two-Higgs-doublet
extensions of the Standard Model. In general, these extensions have scalar
mediated flavour changing neutral currents which are strongly constrained by
experiment. Various strategies are discussed to control these flavour changing
scalar currents and their phenomenological consequences are analysed. In
particular, scenarios with natural flavour conservation are investigated,
including the so-called type I and type II models as well as lepton-specific
and inert models. Type III models are then discussed, where scalar flavour
changing neutral currents are present at tree level, but are suppressed by
either specific ansatze for the Yukawa couplings or by the introduction of
family symmetries. We also consider the phenomenology of charged scalars in
these models. Next we turn to the role of symmetries in the scalar sector. We
discuss the six symmetry-constrained scalar potentials and their extension into
the fermion sector. The vacuum structure of the scalar potential is analysed,
including a study of the vacuum stability conditions on the potential and its
renormalization-group improvement. The stability of the tree level minimum of
the scalar potential in connection with electric charge conservation and its
behaviour under CP is analysed. The question of CP violation is addressed in
detail, including the cases of explicit CP violation and spontaneous CP
violation. We present a detailed study of weak basis invariants which are odd
under CP. A careful study of spontaneous CP violation is presented, including
an analysis of the conditions which have to be satisfied in order for a vacuum
to violate CP. We present minimal models of CP violation where the vacuum phase
is sufficient to generate a complex CKM matrix, which is at present a
requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results;
referee comments taken into account; submitted to Physics Report
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Data from the Pierre Auger Observatory are analyzed to search for
anisotropies near the direction of the Galactic Centre at EeV energies. The
exposure of the surface array in this part of the sky is already significantly
larger than that of the fore-runner experiments. Our results do not support
previous findings of localized excesses in the AGASA and SUGAR data. We set an
upper bound on a point-like flux of cosmic rays arriving from the Galactic
Centre which excludes several scenarios predicting sources of EeV neutrons from
Sagittarius . Also the events detected simultaneously by the surface and
fluorescence detectors (the `hybrid' data set), which have better pointing
accuracy but are less numerous than those of the surface array alone, do not
show any significant localized excess from this direction.Comment: Matches published versio
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
RICORS2040 : The need for collaborative research in chronic kidney disease
Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true
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