175 research outputs found
The formation of planetary disks and winds: an ultraviolet view
Planetary systems are angular momentum reservoirs generated during star
formation. This accretion process produces very powerful engines able to drive
the optical jets and the molecular outflows. A fraction of the engine energy is
released into heating thus the temperature of the engine ranges from the 3000K
of the inner disk material to the 10MK in the areas where magnetic reconnection
occurs. There are important unsolved problems concerning the nature of the
engine, its evolution and the impact of the engine in the chemical evolution of
the inner disk. Of special relevance is the understanding of the shear layer
between the stellar photosphere and the disk; this layer controls a significant
fraction of the magnetic field building up and the subsequent dissipative
processes ougth to be studied in the UV.
This contribution focus on describing the connections between 1 Myr old suns
and the Sun and the requirements for new UV instrumentation to address their
evolution during this period. Two types of observations are shown to be needed:
monitoring programmes and high resolution imaging down to, at least,
milliarsecond scales.Comment: Accepted for publication in Astrophysics and Space Science 9 figure
Theoretical and experimental study of the normal modes in a coupled two-dimensional system
[EN] In this work, the normal modes of a two-dimensional oscillating system have been studied from a theoretical and experimental point of view.
The normal frequencies predicted by the Hessian matrix for a coupled two-dimensional particle system are compared to those obtained for
a real system consisting of two oscillating smartphones coupled one to the other by springs. Experiments are performed on an air table in
order to largely reduce the friction forces. The oscillation data are captured by the acceleration sensor of the smartphones and exported to
file for further analysis. The experimental frequencies compare reasonably well with the theoretical predictions, specifically, within 1.7% of
discrepancy.The authors would like to thank the Institute of Educational Sciences of the Universitat Politecnica de Val ` encia (Spain) ` for the support of the Teaching Innovation Groups MoMa and e-MACAF and for the financial support through the Project PIME 2015 B18. The authors would also like to thank Mrs Janet Anne Handcock for kindly revising the manuscript as a native English speaker.Giménez Valentín, MH.; Castro-Palacio, J.; Gómez-Tejedor, JA.; Velázquez, L.; Monsoriu Serra, JA. (2017). Theoretical and experimental study of the normal modes in a coupled two-dimensional system. Revista Mexicana de Fisica E. 63:100-106. http://hdl.handle.net/10251/99643S1001066
The Smartphone as a Sound Level Meter: Visualizing Acoustical Beats
[EN] Acoustics is a topic in first year Physics courses for engineering students. In this respect, we present in this work a simple experiment to study acoustic beat phenomenon. The superposition of sound waves of slightly different frequencies is captured with the microphone of a smartphone which is placed equidistantly from two speakers which are connected at the same time to AC generators. The smartphone is used here as a measuring instrument. Data registered from the sound level versus time were collected and exported to a «.csv» file for further analysis by means of a free Android application. Based on these data and applying a simple graphing analysis the frequency of the beat was determined and compared with the frequency difference set at the AC generators. Percentage discrepancies within 1% were obtained. This indicates the efficacy of the method used.The authors would like to thank the Institute of Education Sciences of the Universitat Politècnica de València (Spain), for the support to the research groups on teaching innovation MoMa and e-MACAFI and for supporting the Project PIME/2015/B18 which gave rise to this workSalinas Marín, I.; Gimenez Valentin, MH.; Castro-Palacio, J.; Gómez-Tejedor, J.; Monsoriu Serra, JA. (2017). The Smartphone as a Sound Level Meter: Visualizing Acoustical Beats. Tecnica Industrial. 318:34-38. https://doi.org/10.23800/9948S343831
Assessing the responses of exploited marine populations in a context of rapid climate change: the case of blackspot seabream from Strait of Gibraltar.
Assessing the response of exploited marine populations in a context of rapid climate change: the case of
blackspot seabream from the Strait of Gibraltar.—
There is a growing concern over the decline of fisheries and
the possibility of the decline becoming worse due to climate change. Studies on
small–scale fisheries
could help
to improve our understanding of the effect of climate on the ecology of exploited stocks. The Strait of Gibraltar
is an important fishery ground for artisanal fleets.
In this area, b
lackspot seabream (
Pagellus bogaraveo
) is
the main species targeted by artisanal fisheries
in view of its relevance in landed weight.
The aims of this
study were to explore the possible effects of two atmospheric oscillations, the North Atlantic Oscillation (NAO)
and the Arctic Oscillation (AO), on the capture of blackspot seabream in the Strait of Gibraltar, to determine
their association with oceanographic conditions, and to improve our knowledge about the possible effects of
climate change on fisheries ecology so that fishery management can be improved. We used two types of data
from different sources: (i) landings per unit of effort reported from a second working group between Morocco
and Spain on
Pagellus bogaraveo
in the Gibraltar Strait area,
for the period 1983–2011
, and (ii) the recorded
blackspot seabream landings obtained from the annual fisheries statistics published by the
Junta de Andalucía
(Andalusian Regional Government). Our results indicate that the long–term landing of blackspot seabream in
the Strait of Gibraltar is closely associated with atmospheric oscillations. Thus, prolonged periods of positive
trends in the NAO and AO could favour high fishery yields. In contrast, negative trends in NAO and AO could
drastically reduce yield.Postprint0,000
Analysis of the effect of atmospheric oscillations on physical condition of pre–reproductive bluefin tuna from the Strait of Gibraltar
Analysis of the effect of atmospheric oscillations on physical condition of pre–reproductive bluefin tuna from
the Strait of Gibraltar
.— The aim of this study was to explore the possible effects of atmospheric oscillations:
North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), on the physical condition of bluefin tuna (
Thunnus
thynnus
). We estimated a fitness ratio from 3,501 pairs of length–weight data based on bluefin tuna caught in
bait–boat fisheries before the spawning season (January, February and March), for each length class and year.
In order to obtain a single fitness ratio (K–mean) per year we determined the average for all length classes.
We also evaluated
Le Cren’s condition index (K
LC
).
We observed significant positive correlations between the
atmospheric oscillations and both physical condition indexes. In the case of K–mean, the AO explained 75%
of the observed variability. Regarding K
LC
, the NAO explained approximately 73% of the observed variability,
while the AO explained 70% of the observed variability. The increase in physical conditions of bluefin tuna
in association with positive atmospheric oscillations could be mediated by the increase in the prevalence of
strong trade winds. We concluded that the increase in the prevalence of strong westerly winds, mediated by
a positive AO or NAO, favours the trip from the Atlantic to the Mediterranean by reducing energy costs due
to migration and by increasing the supply of nutrients at the surface by the mixing of deep water and surface
water in local areas such as the Strait of Gibraltar.Postprin
Evaluación urodinámica y comparativa de la calidad de vida en pacientes con trastorno de vaciamiento vesical sometidos a terapia InterStim, Medtronic®
ResumenAntecedentesDesde 1980 la terapia de neuroestimulación sacra ha demostrado ser una terapia válida y alternativa en el manejo de los trastornos miccionales por patología del tracto urinario bajo, siendo sus principales indicaciones la retención urinaria idiopática, la incontinencia de urgencia y la incontinencia fecal. En nuestro país sigue siendo una terapia novedosa y no se cuenta aún con estudios que evalúen esta eficacia en términos de calidad de vida o con parámetros cuantitativos.Objetivo del estudioEstablecer la eficacia de la terapia de neuroestimulación sacra tipo InterStim, Medtronic®, en el manejo de los pacientes con trastornos de vaciamiento vesical, efectuando un análisis urodinámico y de la calidad de vida comparativo previo y posterior al tratamiento, determinando los volúmenes miccionales, los períodos de incontinencia, la satisfacción del paciente y la calidad de vida.Material y métodosDesde enero de 2010 hasta junio de 2013, en el Hospital Central Militar se realizó evaluación urodinámica y comparativa de la calidad de vida mediante el empleo del instrumento SF-36 v2 (versión mexicana) e ICIQSF, en los pacientes que presentaron trastorno de vaciamiento vesical de etiología no obstructiva y que fueron refractarios a tratamiento médico.ResultadosSe incluyeron 10 pacientes en el estudio, bajo los siguientes diagnósticos: disinergia detrusor-esfínter, vejiga hiperactiva y retención urinaria no obstructiva, ubicados por género (2 masculinos y 8 femeninos). En la totalidad de los pacientes se presentó mejoría del 50% o superior durante la fase de prueba de la terapia de neuroestimulación, y se colocó fase definitiva con los siguientes resultados: se obtuvieron resultados equivalentes al 50-65% de mejoría en los parámetros cualitativos de función física, función social y rol emocional, así como en las variables cuantitativas de volumen de vaciamiento, eficacia de vaciamiento y disminución de los períodos de incontinencia.DiscusiónComo se ha establecido a nivel de la literatura mundial, nuestros resultados fueron similares en el efecto benéfico y la eficacia en la calidad de vida e incontinencia urinaria, respectivamente, y se reportan porcentajes de éxito mayores al 50% en el cese total de los episodios de incontinencia.ConclusionesLa neuromodulación mediante la estimulación del nervio sacro es una forma exitosa de tratamiento en los trastornos de vaciamiento vesical de etiología no obstructiva y refractaria al tratamiento médico, es segura, mínimamente invasiva y de fácil aplicación, y mejora la calidad de vida de los pacientes. Sin embargo, es necesario realizar estudios aleatorizados y que consideren parámetros objetivos (urodinámicos), así como las complicaciones posibles a mediano y largo plazo en este tipo de terapia.AbstractBackgroundSince 1980, sacral neuromodulation therapy has been shown to be a valid alternative therapy in the management of urinary disorders due to lower urinary tract pathology, and its primary indications are: idiopathic urinary retention, urge incontinence, and fecal incontinence. It is still considered a novel therapy in Mexico and there are no studies using quantitative parameters that evaluate its efficacy in terms of quality of life.AimsTo establish the efficacy of the Medtronic InterStim® sacral neuromodulation therapy in the management of patients with bladder voiding disorders through urodynamic and quality of life analyses before and after treatment. Urine volume, periods of incontinence, patient satisfaction, and quality of life were determined.MethodsA comparative urodynamic and quality of life evaluation was carried out using the SF-36 v2 (Mexican version) and the ICIQSF instruments on patients presenting with nonobstructive bladder voiding disorders that were refractory to medical treatment.ResultsTen patients with the following diagnoses were included in the study: detrusor sphincter dyssynergia, overactive bladder, and nonobstructive urinary retention. Two of the patients were men and 8 were women. There was a 50% or greater improvement in all 10 patients during the test phase of the neuromodulation therapy and the definitive placement phase produced the following results: a 50-65% improvement in the qualitative parameters of physical function, social function, and emotional role, as well as in the quantitative variables of voiding volume, voiding efficacy, and reduced periods of incontinence.DiscussionOur results were similar to those established in the international literature in relation to the beneficial effect on quality of life and efficacy in urinary incontinence management; the literature reports success percentages in the complete cessation of incontinence episodes at above 50%.ConclusionsNeuromodulation through sacral nerve stimulation is a successful form of treatment of nonobstructive and medical treatment-refractory bladder voiding disorders. It is safe, minimally invasive, and easy to apply and it improves patient quality of life. Nevertheless, further randomized studies on this type of therapy need to be conducted that take into account objective parameters (urodynamics) and possible medium and long-term complications
Long-term benefits of nevirapine-containing regimens: multicenter study with 506 patients, followed-up a median of 9 years
[Abstract] OBJECTIVE: To evaluate long-term outcomes in patients maintaining a nevirapine (NVP)-based regimen.
METHODS: Retrospective, multicenter, cohort study including patients currently receiving an NVP regimen that had been started at least 5 years previously. Demographic, clinical, and analytical variables were recorded.
RESULTS: Median follow-up was 8.9 (5.7-11.3) years. Baseline characteristics: 74% men, 47 years old, 36% drug users, 40% AIDS, 40% HCV+, 51.4% detectable HIV-1 viral load, CD4 count 395 (4-1,421)/μL, 19% CD4 3.37 mmol/L significantly decreased in a subsample with available values. A significant decrease in transaminases, alkaline phosphatase, and Fib4 score was observed, mainly in HCV+ and ARV-naive patients.
CONCLUSIONS: In patients who tolerate NVP therapy, (even those with HCV coinfection), long term benefits may be significant in terms of a progressive improvement in general health status markers and CD4 response, a favorable lipid profile, and good liver tolerability
Early elimination of cyclosporine in kidney transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions
Efficacy and safety of a hexanic extract of Serenoa repens (Permixon (R)) for the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH): systematic review and meta-analysis of randomised controlled trials and observational studies
Objectives To comprehensively evaluate the efficacy and safety of the hexanic extract of Serenoa repens (HESr, Permixon (R); Pierre Fabre Medicament, Castres, France), at a dose of 320 mg daily, as monotherapy for the treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). Materials and methods We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) and prospective observational studies in patients with LUTS/BPH identified through searches in Medline, Web of Knowledge (Institute for Scientific Information), Scopus, the Cochrane Library, and bibliographic references up to March 2017. Articles studying S. repens extracts other than Permixon were excluded. Data were collected on International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), nocturia, quality of life, prostate volume, sexual function, and adverse drug reactions (ADRs). Data obtained from RCTs and observational studies were analysed jointly and separately using a random effects model. A sub-group analysis was performed of studies that included patients on longer-term treatment (= 1 year). Results Data from 27 studies (15 RCTs and 12 observational studies) were included for meta-analysis (total N = 5 800). Compared with placebo, the HESr was associated with 0.64 (95% confidence interval [CI] -0.98 to -0.31) fewer voids/ night (P < 0.001) and an additional mean increase in Q(max) of 2.75 mL/s (95% CI 0.57 to 4.93; P = 0.01). When compared with a-blockers, the HESr showed similar improvements on IPSS (weighted mean difference [WMD] 0.57, 95% CI -0.27 to 1.42; P = 0.18) and a comparable increase in Q(max) to tamsulosin (WMD -0.02, 95% CI -0.71 to 0.66; P = 0.95). Efficacy assessed using the IPSS was similar after 6 months of treatment between the HESr and 5a-reductase inhibitors (5ARIs). Analysis of all available published data for the HESr showed a mean improvement in IPSS from baseline of -5.73 points (95% CI -6.91 to -4.54; P < 0.001). HESr did not negatively affect sexual function and no clinically relevant effect was observed on prostate-specific antigen. Prostate volume decreased slightly. Similar efficacy results were seen in patients treated for = 1 year (n = 447). The HESr had a favourable safety profile, with gastrointestinal disorders being the most frequent ADR (mean incidence of 3.8%). Conclusion The present meta-analysis, which includes all available RCTs and observational studies, shows that the HESr (Permixon) reduced nocturia and improved Q(max) compared with placebo and had a similar efficacy to tamsulosin and short-term 5ARI in relieving LUTS. HESr (Permixon) appears to be an efficacious and well-tolerated therapeutic option for the longterm medical treatment of LUTS/BPH
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