2,082 research outputs found
Recent activity of the Be/X-ray binary system SAX J2103.5+4545
Aims. We present a multiwavelength study of the Be/X-ray binary system SAX
J2103.5+4545 with the goal of better characterizing the transient behaviour of
this source.
Methods. SAX J2103.5+4545 was observed by Swift-XRT four times in 2007 from
April 25 to May 5, and during quiescence in 2012 August 31. In addition, this
source has been monitored from the ground-based astronomical observatories of
El Teide (Tenerife, Spain), Roque de los Muchachos (La Palma, Spain) and Sierra
Nevada (Granada, Spain) since 2011 August, and from the TUBITAK National
Observatory (Antalya, Turkey) since 2009 June. We have performed spectral and
photometric temporal analyses in order to investigate the different states
exhibited by SAX J2103.5+4545.
Results. In X-rays, an absorbed power law model provided the best fit for all
the XRT spectra. An iron-line feature at ~6.42 keV was present in all the
observations except for that taken during quiescence in 2012. The photon
indexes are consistent with previous studies of SAX J2103.5+4545 in high/low
luminosity states. Pulsations were found in all the XRT data from 2007
(2.839(2) mHz; MJD 54222.02), but not during quiescence. Both optical outbursts
in 2010 and 2012 lasted for about 8/9 months (as the one in 2007 probably did
and the current one in 2014 might do) and were most probably caused by mass
ejection events from the Be star that eventually fed the circumstellar disc.
All of these outbursts started about 3 months before the triggering of the
X-ray activity, and about the same period before the maximum of the H_alpha
line equivalent width (in emission) was reached at only ~ -5 \AA. In this work
we found that the global correlation between the BV variability and the X-ray
intensity was also observed at longer wavelengths in the IR domain.Comment: 11 pages, 7 figures, and online material (2 tables). Submitted to A&A
in 2014 Januar
Detection of a large Be circumstellar disk during X-ray quiescence of XTE J1946+274
We present a multiwavelength study of the Be/X-ray binary system XTE
J1946+274 with the main goal of better characterizing its behavior during X-ray
quiescence. We aim to shed light on the mechanism which triggers the X-ray
activity for this source. XTE J1946+274 was observed by Chandra-ACIS during
quiescence in 2013 March 12. In addition, this source has been monitored from
the ground-based astronomical observatories of El Teide (Tenerife, Spain),
Roque de los Muchachos (La Palma, Spain) and Sierra Nevada (Granada, Spain)
since 2011 September, and from the TUBITAK National Observatory (Antalya,
Turkey) since 2005 April. We have performed spectral and photometric temporal
analyses in order to investigate the quiescent state and transient behavior of
this binary system. In 2006, a long mass ejection event took place from the Be
star, lasting for about seven years. We also found that a large Be
circumstellar disk was present during quiescence, although major X-ray activity
was not observed. We made an attempt to explain this scenario by assuming the
permanently presence of a tilted and warped Be circumstellar disk. The 0.3-10
keV X-ray spectrum during quiescence was well fitted with either an absorbed
blackbody or absorbed power-law models. The main parameters obtained for these
models were kT=1.43+/-0.17 and Gamma=0.9+/-0.4 (with N_H~2-7E+22 cm-2). The
0.3-10 keV flux of the source was ~0.8E-12 erg-1 cm-2 s-1. Pulsations were
found with P_pulse=15.757(1) s (MJD 56363.115) and an rms pulse fraction of
32.1(3)%. The observed X-ray luminosity during quiescent periods may be
explained by the neutron star being in supersonic propeller regimen.Comment: 9 pages, 7 figures, accepte
Perinatal asphyxia: CNS development and deficits with delayed onset
Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary
oxygenation is delayed or interrupted. The primary insult relates to the duration of the period
lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary
insult, related to a cascade of biochemical events required for restoring proper function. Perinatal
asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental
and neurological diseases with delayed clinical onset, by mechanisms not yet clarified.
In the experimental scenario, the effects observed long after perinatal asphyxia have been explained
by over expression of sentinel proteins, such as poly(ADP-ribose) polymerase-1 (PARP-1),
competing for NAD+ during re-oxygenation, leading to the idea that sentinel protein inhibition
constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of proinflammatory
factors, in tandem with PARP-1 overactivation, and pharmacologically induced
PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines.
Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in
an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing
rat foetuses into a water bath for various periods of time. Following asphyxia, the pups are
delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide
rapidly distributes into the brain following systemic administration, reaching steady state
concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the
long-term consequences of perinatal asphyxia, supporting the idea that it constitutes a lead for
exploring compounds with similar or better pharmacological profiles
Evaluating the design of the Integrated Care for Older People: a theory of change approach
IntroductionGiven the progressive aging of the population, there is an urgent need at the health system level to implement effective models to care for older people (OP). Healthy aging is imperative to reach the Sustainable Development Goals. The World Health Organization (WHO) developed the Integrated Care for Older People (ICOPE) strategy to address this challenge. Implementing ICOPE requires its adaption to a specific context. We propose a pathway for such adaptation through an evaluation of the design of ICOPE; thus, we aim to describe the Theory of Change (ToC) of ICOPE and evaluate it for its implementation in Mexico City.MethodsBased on the WHO and published literature documentation, we drafted an initial ToC for ICOPE. Then, we validated the ToC with experts in ICOPE, after which we evaluated and refined it by discussing the causal pathway, intervention required to activate it, rationale, and assumptions in consecutive workshops with 91 stakeholders and healthcare workers, using the nominal group technique to reach a consensus.ResultsThe resulting ToC has the potential to contribute to healthy aging by three expected impacts: (1) prevention, reversal, or delaying of the decline of intrinsic capacity (IC) in OP; (2) improvement of the quality of life of OP; and (3) increase of disability-free life expectancy. The ICOPE causal pathway had ten preconditions, including the availability of resources, identifying at-risk individuals, available treatments, and evaluating results.DiscussionWe adapted ICOPE to a specific implementation context by evaluating its ToC in a participatory process that allows us to identify challenges and address them, at least in terms of the guidelines to operate the strategy. As ICOPE is an approach for a primary healthcare system, its adoption in a community healthcare program is promising and feasible. Evaluation as a tool could contribute to the design of effective interventions. The evaluation of the design of ICOPE for its implementation contributes to the strength of its potential to improve care for OP. This design for implementing ICOPE has the potential to be applied to similar contexts, for example, in other lower-middle-income countries
Comparación ultrasonográfica transvaginal y transrectal de la dinámica folicular en ondas sucesivas de llamas (Lama glama)
The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum follicular diameter and duration of follicular wave via TR was y=0.89766x+6.5554 (R²=0.423) and for the TV route y=0.8466x+10.184 (R²=0.479). The duration of the follicular phases was similar between both techniques except for the dominance phase (10.2±3.19 days for TR and 8.67±2.46 for TV, p=0.0418). The relationship between the follicular diameter and the number of follicles detected showed a low negative correlation (R²=-0.0827 for TV and R²=-0.0876 for TR). In conclusion, the transvaginal endocavitary transducer makes it possible to determine with greater precision the characteristics of llama follicular dynamics in their recruitment, dominance and regression phases with overlapping of follicular waves as an important characteristic.La dinámica folicular ovárica monitoreada por vÃa transrectal (TR) y transvaginal (TV) en ondas sucesivas en llamas fue estudiada en 10 llamas con más de 4 años, multÃparas, sin crÃa, estado corporal de 3.0, durante un periodo de 90 dÃas en la época reproductiva. Se utilizó el ecógrafo Sonostar SS8® con un transductor lineal para el examen transrectal y transductor microconvexo endocavitario para el examen transvaginal, ambos con frecuencia de 6.5 MHz. El intervalo inter-onda fue de 20±4.4 y 22.5±5.3 por vÃa TR y TV, respectivamente; el número de folÃculos por cohorte fue 5.21±0.92 y 6.38±1.26 para TR y TV, respectivamente (p=0.0011); el diámetro máximo de folÃculos fue 12.49±3.57 mm para TR y 13.56±3.91 mm para TV; la tasa de crecimiento fue de 0.70±0.35 y 0.67±0.32 mm/dÃa para TR y TV, respectivamente. La ecuación de regresión para relación del diámetro máximo folicular y duración de onda folicular vÃa TR fue de y=0.89766x+6.5554 (R²=0.423) y para la vÃa TV de y=0.8466x+10.184 (R²=0.479). La duración de las fases foliculares fue similar entre ambas técnicas con excepción de la fase de dominancia (10.2±3.19 dÃas para TR y 8.67±2.46 para TV, p=0.0418). La relación entre el diámetro folicular y número de folÃculos detectados presentó una correlación negativa baja (R²=-0.0827 para TV y R²=-0.0876 para TR). En conclusión, el transductor endocavitario transvaginal permite determinar con mayor precisión las caracterÃsticas de dinámica folicular en llamas en sus fases de reclutamiento, dominancia y regresión con sobreposición de ondas foliculares como caracterÃstica importante.The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum follicular diameter and duration of follicular wave via TR was y=0.89766x+6.5554 (R²=0.423) and for the TV route y=0.8466x+10.184 (R²=0.479). The duration of the follicular phases was similar between both techniques except for the dominance phase (10.2±3.19 days for TR and 8.67±2.46 for TV, p=0.0418). The relationship between the follicular diameter and the number of follicles detected showed a low negative correlation (R²=-0.0827 for TV and R²=-0.0876 for TR). In conclusion, the transvaginal endocavitary transducer makes it possible to determine with greater precision the characteristics of llama follicular dynamics in their recruitment, dominance and regression phases with overlapping of follicular waves as an important characteristic
GENERALIZED URTICARIA AS A VASCULITIC MANIFESTATION IN A PATIENT WITH SARS-CoV-2 INFECTION: A CASE REPORT IN COLOMBIA
Skin manifestations have been reported in up to 20% of cases of SARS-CoV-2 infection, including morbilliform rash (22%), pernio-like acral lesions (18%), urticaria (16%), and macular erythema (13%). It is believed that in the case of SARS-CoV-2 infection, the mechanism involved is an inflammatory response that generates immune dysregulation, vascular congestion, vasculitis, vascular thrombosis, or neoangiogenesis. This case study, present the case of a patient with no previous history of urticarial reactions, autoimmune diseases, or exposure to medications who develops generalized urticaria lasting more than 24 hours and who was diagnosed with SARS-CoV-2 infection by RT-PCR with a nasopharyngeal swab. We suggest in this patient vasculitic urticaria as a manifestation of SARS-CoV-2 infection
Unravelling the mechanisms that determine the uptake and metabolism of magnetic single and multicore nanoparticles in a Xenopus laevis model.
Multicore superparamagnetic nanoparticles have been proposed as ideal tools for some biomedical applications because of their high magnetic moment per particle, high specific surface area and long term colloidal stability. Through controlled aggregation and packing of magnetic cores it is possible to obtain not only single-core but also multicore and hollow spheres with internal voids. In this work, we compare toxicological properties of single and multicore nanoparticles. Both types of particles showed moderate in vitro toxicity (MTT assay) tested in Hep G2 (human hepatocellular carcinoma) and Caco-2 (human colorectal adenocarcinoma) cells. The influence of surface chemistry in their biological behavior was also studied after functionalization with O,O′-bis(2-aminoethyl) PEG (2000 Da). For the first time, these nanoparticles were evaluated in a Xenopus laevis model studying their whole organism toxicity and their impact upon iron metabolism. The degree of activation of the metabolic pathway depends on the size and surface charge of the nanoparticles which determine their uptake. The results also highlight the potential of Xenopus laevis model bridging the gap between in vitro cell-based assays and rodent models for toxicity assessment to develop effective nanoparticles for biomedical applications
COSMOGRAIL XVI: Time delays for the quadruply imaged quasar DES J0408-5354 with high-cadence photometric monitoring
We present time-delay measurements for the new quadruply imaged quasar DES
J0408-5354, the first quadruply imaged quasar found in the Dark Energy Survey
(DES). Our result is made possible by implementing a new observational strategy
using almost daily observations with the MPIA 2.2m telescope at La Silla
observatory and deep exposures reaching a signal-to-noise ratio of about 1000
per quasar image. This data quality allows us to catch small photometric
variations (a few mmag rms) of the quasar, acting on temporal scales much
shorter than microlensing, hence making the time delay measurement very robust
against microlensing. In only 7 months we measure very accurately one of the
time delays in DES J0408-5354: Dt(AB) = -112.1 +- 2.1 days (1.8%) using only
the MPIA 2.2m data. In combination with data taken with the 1.2m Euler Swiss
telescope, we also measure two delays involving the D component of the system
Dt(AD) = -155.5 +- 12.8 days (8.2%) and Dt(BD) = -42.4 +- 17.6 days (41%),
where all the error bars include systematics. Turning these time delays into
cosmological constraints will require deep HST imaging or ground-based Adaptive
Optics (AO), and information on the velocity field of the lensing galaxy.Comment: 9 pages, 5 figures, accepted for publication in Astronomy &
Astrophysic
Response timing in the lunge and target change in elite versus medium-level fencers.
The aim of the present work is to examine the differences between two groups of fencers with different levels of competition, elite and medium level. The timing parameters of the response reaction have been compared together with the kinetic variables which determine the sequence of segmented participation used during the lunge with a change in target during movement. A total of 30 male sword fencers participated, 13 elite and 17 medium level. Two force platforms recorded the horizontal component of the force and the start of the movement. One system filmed the movement in 3D, recording the spatial positions of 11 markers, while another system projected a mobile target over a screen. For synchronisation, an electronic signal enabled all the systems to be started simultaneously. Among the timing parameters of the reaction response, the choice reaction time (CRT) to the target change during the lunge was measured. The results revealed differences between the groups regarding the flight time, horizontal velocity at the end of the acceleration phase, and the length of the lunge, these being higher for the elite group, as well as other variables related to the temporal sequence of movement. No significant differences have been found in the simple reaction time or in CRT. According to the literature, the CRT appears to improve with sports practice, although this factor did not differentiate the elite from medium-level fencers. The coordination of fencing movements, that is, the right technique, constitutes a factor that differentiates elite fencers from medium-level ones
Ablation of the carboxy-terminal end of MAMDC2 causes a distinct muscular dystrophy
The extracellular matrix (ECM) has an important role in the development and maintenance of skeletal muscle, and several muscle diseases are associated with the dysfunction of ECM elements. MAMDC2 is a putative ECM protein and its role in cell proliferation has been investigated in certain cancer types. However, its participation in skeletal muscle physiology has not been previously studied.
We describe 17 individuals with an autosomal dominant muscular dystrophy belonging to two unrelated families in which different heterozygous truncating variants in the last exon of MAMDC2 co-segregate correctly with the disease. The radiological aspect of muscle involvement resembles that of COL6 myopathies with fat replacement at the peripheral rim of vastii muscles. In this cohort, a subfascial and peri-tendinous pattern is observed in upper and lower limb muscles. Here we show that MAMDC2 is expressed in adult skeletal muscle and differentiating muscle cells, where it appears to localize to the sarcoplasm and myonuclei. In addition, we show it is secreted by myoblasts and differentiating myotubes into to the extracellular compartment. The last exon encodes a disordered region with a polar residue compositional bias loss of which likely induces a toxic effect of the mutant protein. The precise mechanisms by which the altered MAMDC2 proteins cause disease remains to be determined.
MAMDC2 is a skeletal muscle disease-associated protein. Its role in muscle development and ECM-muscle communication remains to be fully elucidated. Screening of the last exon of MAMDC2 should be considered in patients presenting with autosomal dominant muscular dystrophy, particularly in those with a subfascial radiological pattern of muscle involvement.This work was supported by resources provided by the Pawsey Supercomputing Centre with funding from the Australian National Health and Medical Research Council Ideas Grant APP2002640, Fellowships APP1117510 and APP1122952 and Investigator Grant APP2007769, the Australian Government and the Government of Western Australia as well as the Instituto de Salud Carlos III (grant numbers PI19/01497, PI21/00759 and PI20/01200) and Junta de Andalucia, Consejeria de Salud y Consumo (grant numbers PIER-0100-2019 and PIER-0468-2019). M.C-S. has been supported by Instituto de Salud Carlos III (BAE21/00007 at the HRACall 2021). L.D. is supported by an Australian Government Research Training Program at the University of Western Australia (RTP) Scholarship. G.C. has been supported by ConsejerÃa de Salud y Consumo, Junta de AndalucÃa and Programa Operativo Fondo Social Europeo de AndalucÃa 2014-2020 (RH0046-2020).Peer reviewe
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