162 research outputs found
The VISCACHA survey -- V. Rejuvenating three faint SMC clusters
We present the analysis of three faint clusters of the Small Magellanic Cloud
RZ82, HW42 and RZ158. We employed the SOAR telescope instrument SAM with
adaptive optics, allowing us to reach to V~23-24 mag, unprecedentedly, a depth
sufficient to measure ages of up to about 10-12Gyr. All three clusters are
resolved to their centres, and the resulting colour-magnitude diagrams (CMDs)
allow us to derive ages of 3.9, 2.6, and 4.8Gyr respectively. These results are
significantly younger than previous determinations (7.1, 5.0, and 8.3Gyr,
respectively), based on integrated photometry or shallower CMDs. We rule out
older ages for these clusters based on deep photometry and statistical
isochrone fitting. We also estimate metallicities for the three clusters of
[Fe/H]=-0.68, -0.57 and -0.90, respectively. These updated ages and
metallicities are in good agreement with the age-metallicity relation for the
bulk of SMC clusters. Total cluster masses ranging from ~7-11x10^3Mo were
estimated from integrated flux, consistent with masses estimated for other SMC
clusters of similar ages. These results reduce the number of SMC clusters known
to be older than about 5 Gyr and highlight the need of deep and spatially
resolved photometry to determine accurate ages for older, low-luminosity SMC
star clusters.Comment: Accepted for publication as MNRAS letter, 5 pages, 5 figure
Classificação de solos em uma topossequência na sub-bacia do Córrego Maria Casimira no Parque Nacional da Serra do Gandarela, Minas Gerais.
The VISCACHA survey -- VII. Assembly history of the Magellanic Bridge and SMC Wing from star clusters
The formation scenario of the Magellanic Bridge during an encounter between
the Large and Small Magellanic Clouds Myr ago, as proposed by
-body models, would be imprinted in the chemical enrichment and kinematics
of its stars, and sites of ongoing star formation along its extension. We
present an analysis of 33 Bridge star clusters using photometry obtained with
the SOAR 4-m telescope equipped with adaptive optics for the VISCACHA survey.
We performed a membership selection and derived self-consistent ages,
metallicities, distances and reddening values via statistical isochrone
fitting, as well as tidal radii and integrated masses from structure analysis.
Two groups are clearly detected: 13 well-studied clusters older than the
Bridge, with Gyr and dex; and 15 clusters with
dex, probably formed in-situ. The old
clusters follow the overall age and metallicity gradients of the SMC, whereas
the younger ones are uniformly distributed along the Bridge. The main results
are as follows: we derive ages and metallicities for the first time for 9
and 18 clusters, respectively; we detect two metallicity dips in the
age-metallicity relation of the Bridge at Myr and Gyr ago
for the first time, possibly chemical signatures of the formation of the Bridge
and Magellanic Stream; we estimate a minimum stellar mass for the
Bridge of ; we confirm that all the young
Bridge clusters at are metal-rich dex.Comment: 15 pages, 13 figures + appendix. Accepted for publication in MNRA
Capturing protest in urban environments:The ‘police kettle’ as a territorial strategy
‘Kettling’ has emerged in recent decades as an established, if controversial, tactic of public order policing. Departing from a historical emphasis on dispersal, kettling instead acts to contain protesters within a police cordon for sustained periods of time. This article elaborates upon the spatial and temporal logics of kettling by investigating the conditions of is historical emergence. We argue that kettling should be understood as a territorial strategy that co-evolved in relation to forms of disruptive protest. Whereas techniques of crowd dispersal serve to diffuse a unified collective, ‘kettling’ aims to capture the volatile intensities of public dissent and exhaust its political energies. Drawing on police manuals, media coverage, accounts from activists and expert interviews, we show how the ‘kettle’ re-territorializes protest by acting on its spatio-temporal and affective constitution. By fabricating an inner outside of the urban milieu, freezing the time of collective mobilization and inducing debilitating affects such as fear and boredom, kettling intervenes into the scene of political subjectification that each congregation of protesting bodies seeks to fashion
The VISCACHA survey-deep and resolved photometry of star clusters in the Magellanic Clouds
The VISCACHA (VIsible Soar photometry of star Clusters in tApii and Coxi HuguA†) Survey is an ongoing project based on deep and spatially resolved photometric observations of Magellanic Cloud star clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with the SOAR Adaptive Module Imager. So far we have used >300h of telescope time to observe ∼150 star clusters, mostly with low mass (M < 104M⊠) on the outskirts of the LMC and SMC. With this high-quality data set, we homogeneously determine physical properties using deep colour-magnitude diagrams (ages, metallicities, reddening, distances, mass, luminosity and mass functions) and structural parameters (radial density profiles, sizes) for these clusters which are used as a proxy to investigate the interplay between the Magellanic Clouds and their evolution. We present the VISCACHA survey and its initial results, based on our first two papers. The project's long term goals and expected legacy to the community are also addressed.Fil: Dias, Bruno. European Southern Observatory Chile; Chile. Universidad Andrés Bello; ChileFil: Maia, Francisco. Universidade Federal do Rio de Janeiro; BrasilFil: Kerber, Leandro. Universidade Estadual de Santa Cruz; BrasilFil: Dos Santos, João F. C.. Universidade Federal de Minas Gerais; BrasilFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Armond, Tina. Universidade Federal de São João del Rei; BrasilFil: Barbuy, Beatriz. Universidade de Sao Paulo; BrasilFil: Fraga, Luciano. Laboratório Nacional de Astrofísica; BrasilFil: Hernandez Jimenez, Jose A.. Universidad Andrés Bello; ChileFil: Katime Santrich, Orlando J.. Universidade Estadual de Santa Cruz; BrasilFil: Oliveira, Raphael A. P.. Universidade de Sao Paulo; BrasilFil: Pérez Villegas, Angeles. Universidade de Sao Paulo; BrasilFil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Quint, Bruno. Observatorio Gemini; ChileFil: Sanmartin, David. Observatorio Gemini; ChileFil: Angelo, Mateus S.. Centro Federal de Educação Tecnológica de Minas Gerais; BrasilFil: Souza, Stefano O.. Universidade de Sao Paulo; BrasilFil: Vieira, Rodrigo G.. Universidade de Sao Paulo; BrasilFil: Westera, Pieter. Universidad Federal Do Abc; BrasilFil: Parisi, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Geisler, Doug. Universidad de La Serena; Chile. Universidad de Concepción; ChileFil: Minniti, Dante. Universidad Andrés Bello; Chile. Millennium Institute of Astrophysics; Chile. Vatican Observatory; ItaliaFil: Saito, Roberto. Universidade Federal de Santa Catarina; BrasilFil: Bassino, Lilia Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: de Bórtoli, Bruno Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Figueiredo, André. Universidade de Sao Paulo; BrasilFil: Rímulo, Leandro. Universidad de los Andes; Colombi
Polymorphic variants of SCN1A and EPHX1 influence plasma carbamazepine concentration, metabolism and pharmacoresistance in a population of Kosovar Albanian epileptic patients
Aim
The present study aimed to evaluate the effects of gene variants in key genes influencing pharmacokinetic and pharmacodynamic of carbamazepine (CBZ) on the response in patients with epilepsy.
Materials & Methods
Five SNPs in two candidate genes influencing CBZ transport and metabolism, namely ABCB1 or EPHX1, and CBZ response SCN1A (sodium channel) were genotyped in 145 epileptic patients treated with CBZ as monotherapy and 100 age and sex matched healthy controls. Plasma concentrations of CBZ, carbamazepine-10,11-epoxide (CBZE) and carbamazepine-10,11-trans dihydrodiol (CBZD) were determined by HPLC-UV-DAD and adjusted for CBZ dosage/kg of body weight.
Results
The presence of the SCN1A IVS5-91G>A variant allele is associated with increased epilepsy susceptibility. Furthermore, carriers of the SCN1A IVS5-91G>A variant or of EPHX1 c.337T>C variant presented significantly lower levels of plasma CBZ compared to carriers of the common alleles (0.71±0.28 vs 1.11±0.69 μg/mL per mg/Kg for SCN1A IVS5-91 AA vs GG and 0.76±0.16 vs 0.94±0.49 μg/mL per mg/Kg for EPHX1 c.337 CC vs TT; PG showed a reduced microsomal epoxide hydrolase activity as reflected by a significantly decreased ratio of CBZD to CBZ (0.13±0.08 to 0.26±0.17, pT SNP and SCN1A 3148A>G variants were not associated with significant changes in CBZ pharmacokinetic. Patients resistant to CBZ treatment showed increased dosage of CBZ (657±285 vs 489±231 mg/day; P<0.001) but also increased plasma levels of CBZ (9.84±4.37 vs 7.41±3.43 μg/mL; P<0.001) compared to patients responsive to CBZ treatment. CBZ resistance was not related to any of the SNPs investigated.
Conclusions
The SCN1A IVS5-91G>A SNP is associated with susceptibility to epilepsy. SNPs in EPHX1 gene are influencing CBZ metabolism and disposition. CBZ plasma levels are not an indicator of resistance to the therapy
O jogo de empresas no processo de aprendizagem em administração: o discurso coletivo de alunos
Biometria e parâmetros hematológicos em tartarugas da Amazônia de um criatório comercial de Rio Branco/AC
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