675 research outputs found
Potential impacts of climate variability on Dengue Hemorrhagic Fever in Honduras, 2010
Climate change and variability are affecting human health and disease direct or indirectly through many mechanisms. Dengue is one of those diseases that is strongly influenced by climate variability; however its study in Central America has been poorly approached. In this study, we assessed potential associations between macroclimatic and microclimatic variation and dengue hemorrhagic fever (DHF) cases in the main
hospital of Honduras during 2010. In this year, 3,353 cases of DHF were reported in the
Hospital Escuela, Tegucigalpa. Climatic periods marked a difference of 158% in the mean incidence of cases, from El Niño weeks (-99% of cases below the mean incidence) to La Niña months (+59% of cases above it) (p<0.01). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (p=0.0097), higher rain probability (p=0.0149), accumulated rain (p=0.0443) and higher relative humidity (p=0.0292). At a multiple linear regression model using those variables, ONI values shown to be the most important and significant factor found to be associated with the monthly occurrence of DHF cases (r2=0.649; βstandardized=–0.836; p=0.01). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in
Honduras. However, it is necessary to extend these studies in this and other countries in
the Central America region, because these models can be applied for surveillance as
well as for prediction of dengue
Quantum Gravity Hamiltonian for Manifolds with Boundary
In canonical quantum gravity, when space is a compact manifold with boundary
there is a Hamiltonian given by an integral over the boundary. Here we compute
the action of this `boundary Hamiltonian' on observables corresponding to open
Wilson lines in the new variables formulation of quantum gravity. In cases
where the boundary conditions fix the metric on the boundary (e.g., in the
asymptotically Minkowskian case) one can obtain a finite result, given by a
`shift operator' generating translations of the Wilson line in the direction of
its tangent vector. A similar shift operator serves as the Hamiltonian
constraint in Morales-T\'ecotl and Rovelli's work on quantum gravity coupled to
Weyl spinors. This suggests the appearance of an induced field theory of Weyl
spinors on the boundary, analogous to that considered in Carlip's work on the
statistical mechanics of the 2+1-dimensional black hole.Comment: 17 pages in LaTeX format, vastly improved versio
Adrenalectomy promotes a permanent decrease of plasma corticoid levels and a transient increase of apoptosis and the expression of Transforming Growth Factor β1 (TGF-β1) in hippocampus: effect of a TGF-β1 oligo-antisense
BACKGROUND: Corticosterone reduction produced by adrenalectomy (ADX) induces apoptosis in dentate gyrus (DG) of the hippocampus, an effect related to an increase in the expression of the pro-apoptotic gene bax. However it has been reported that there is also an increase of the anti-apoptotic gene bcl-2, suggesting the promotion of a neuroprotective phenomenon, perhaps related to the expression of transforming growth factor β1 (TGF-β1). Thus, we have investigated whether TGF-β1 levels are induced by ADX, and whether apoptosis is increased by blocking the expression of TGF-β1 with an antisense oligonucleotide (ASO) administered intracerebrally in corticosterone depleted rats. RESULTS: It was observed an increase of apoptosis in DG, 2 and 5 days after ADX, in agreement with a reduction of corticosterone levels. However, the effect of ADX on the number of apoptotic positive cells in DG was decreased 5 days after the lesion. In CA1–CA3 regions, the effect was only observed 2 days after ADX. TGF-β1 mRNA levels were increased 2 days after ADX. The sustained intracerebro-ventricular administration of a TGF-β1 ASO via an osmotic mini pump increased apoptosis levels in CA and DG regions 5 days after ADX as well as sham-operated control animals. No significant effect was observed following a scrambled-oligodeoxynucleotide treatment. CONCLUSION: The changes in both the pattern and the magnitude of apoptotic-cell morphology observed 2 and 5 days after ADX suggest that, as a consequence of the reduction of corticosteroids, some trophic mechanisms restricting cell death to a particular time window are elicited. Sustained intracerebral administration of TGF-β1 ASO increased the apoptosis promoted by ADX, suggesting that TGF-β1 plays an anti-apoptotic role in vivo in hippocampus
Infographic. How does exercise treatment compare with antihypertensive medications?
High systolic blood pressure (SBP) remains the major cause of premature death globally despite advances in pharmacological treatment.1 2 The global direct medical costs associated with hypertension treatment are estimated at 100 billion/year.3 Unfortunately, relatively little attention is given to non-pharmacological strategies, including structured exercise interventions. A recent network meta-analysis of randomised controlled trials (RCTs) published in the BJSM4 aimed to compare the effects of exercise interventions and medications on SBP. We highlight the key findings of this network meta-analysis that are particularly relevant for clinical practice and health policy.Sin financiaciĂłn12.022 JCR (2019) Q1, 1/85 Sport Sciences3.712 SJR (2019) Q1, 48/2754 Medicine (miscellaneous), 1/284 Orthopedics and Sports Medicine, 1/207 Physical Therapy, Sports Therapy and Rehabilitation, 2/125 Sports ScienceNo data IDR 2019UE
Viejas aunque “nuevas” metodologĂas de enseñanza-aprendizaje: los talleres de experimentaciĂłn lĂtica prehistĂłrica como herramienta de formaciĂłn
Explicar y comprender la Historia de la Humanidad requiere conocer cĂłmo y quĂ© herramientas se fueron elaborando a lo largo de más de 2,5 millones de años. Una parte importante de dichos instrumentos se fabricaron durante la Prehistoria usando diferentes tipos de rocas. AsĂ, entre los contenidos curriculares incluidos en los grados en Historia y en másteres afines en España, destacan diversas nociones sobre tecnologĂa e instrumental lĂtico prehistĂłrico, con los que se intenta que el alumnado conozca los procesos de producciĂłn lĂtica tallada, su evoluciĂłn tecnolĂłgica y tipolĂłgica, y los procesos de clasificaciĂłn y análisis. El empleo de material gráfico como recurso docente, se viene mostrando insuficiente para conseguir buenos resultados de aprendizaje. El desarrollo de talleres de experimentaciĂłn lĂtica tallada sobre instrumental prehistĂłrico constituye la mejor metodologĂa de enseñanza-aprendizaje con la que mostrar e interactuar con los estudiantes, aunque dicha actividad requiere de una serie de condiciones de difĂcil consecuciĂłn. La experiencia llevada a cabo en asignaturas del Grado en Historia y del Máster en ArqueologĂa Profesional y GestiĂłn del Patrimonio de la UA, es un claro ejemplo de evaluaciĂłn de las fortalezas y debilidades de la implementaciĂłn de dichos talleres
Thienopyrimidine Derivatives as GPR55 Receptor Antagonists: Insight into Structure-Activity Relationship
GPR55 is an orphan G-protein coupled receptor involved in various pathophysiological conditions. However, there are only a few noncannabinoid GPR55 ligands reported so far. The lack of potent and selective GPR55 ligands precludes a deep exploration of this receptor. The studies presented here focused on a thienopyrimidine scaffold based on the GPR55 antagonist ML192, previously discovered by high-throughput screening. The GPR55 activities of the new synthesized compounds were assessed using β-arrestin recruitment assays in Chinese hamster ovary cells overexpressing human GPR55. Some derivatives were identified as GPR55 antagonists with functional efficacy and selectivity versus CB1 and CB2 cannabinoid receptors.M.E.A., P.H.R., and N.J. are supported by National Institutes of Health grant R01 DA0455698. M.E.A. and P.Z. thank the financial support NIH P30 DA013429. P.M. and N.J. are supported by the Ministry of Science, Innovation, and Universities, Spain (MCIU)/FEDER grant RTI2018-095544-B-I00 and the Spanish National Research Council (CSIC) grant PIE-201580E033. P.M. acknowledges the Comunidad de Madrid (CM) programme “Atraccion de Talento” number 2018-T2/BMD-10819 and “Juan de la Cierva Incorporación Programme-MICIU” (IJC 2019-042182-I
Asymmetric Dark Matter and Dark Radiation
Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry,
similar to the one observed in the Baryon sector, to account for the Dark
Matter (DM) abundance. Both asymmetries are usually generated by the same
mechanism and generally related, thus predicting DM masses around 5 GeV in
order to obtain the correct density. The main challenge for successful models
is to ensure efficient annihilation of the thermally produced symmetric
component of such a light DM candidate without violating constraints from
collider or direct searches. A common way to overcome this involves a light
mediator, into which DM can efficiently annihilate and which subsequently
decays into Standard Model particles. Here we explore the scenario where the
light mediator decays instead into lighter degrees of freedom in the dark
sector that act as radiation in the early Universe. While this assumption makes
indirect DM searches challenging, it leads to signals of extra radiation at BBN
and CMB. Under certain conditions, precise measurements of the number of
relativistic species, such as those expected from the Planck satellite, can
provide information on the structure of the dark sector. We also discuss the
constraints of the interactions between DM and Dark Radiation from their
imprint in the matter power spectrum.Comment: 22 pages, 5 figures, to be published in JCAP, minor changes to match
version to be publishe
Probing Nucleation Mechanism of Self-Catalyzed InN Nanostructures
The nucleation and evolution of InN nanowires in a self-catalyzed growth process have been investigated to probe the microscopic growth mechanism of the self-catalysis and a model is proposed for high pressure growth window at ~760 Torr. In the initial stage of the growth, amorphous InNx microparticles of cone shape in liquid phase form with assistance of an InNx wetting layer on the substrate. InN crystallites form inside the cone and serve as the seeds for one-dimensional growth along the favorable [0001] orientation, resulting in single-crystalline InN nanowire bundles protruding out from the cones. An amorphous InNx sheath around the faucet tip serves as the interface between growing InN nanowires and the incoming vapors of indium and nitrogen and supports continuous growth of InN nanowires in a similar way to the oxide sheath in the oxide-assisted growth of other semiconductor nanowires. Other InN 1D nanostructures, such as belts and tubes, can be obtained by varying the InN crystallites nucleation and initiation process
Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours: results from the COPPADIS cohort.
The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose
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