549 research outputs found
GRO J1744-28: an intermediate B-field pulsar in a low mass X-ray binary
The bursting pulsar, GRO J1744-28, went again in outburst after 18
years of quiescence in mid-January 2014. We studied the broad-band, persistent,
X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost
at the peak of the outburst, and from a close INTEGRAL observation, performed 3
days later, thus covering the 1.3-70.0 keV band. The spectrum shows a complex
continuum shape that cannot be modelled with standard high-mass X-ray pulsar
models, nor by two-components models. We observe broadband and peaked residuals
from 4 to 15 keV, and we propose a self-consistent interpretation of these
residuals, assuming they are produced by cyclotron absorption features and by a
moderately smeared, highly ionized, reflection component. We identify the
cyclotron fundamental at 4.7 keV, with hints for two possible harmonics
at 10.4 keV and 15.8 keV. The position of the cyclotron fundamental allows an
estimate for the pulsar magnetic field of (5.27 0.06) 10
G, if the feature is produced at its surface. From the dynamical and
relativistic smearing of the disk reflected component, we obtain a lower limit
estimate for the truncated accretion disk inner radius, ( 100 R),
and for the inclination angle (18-48). We also detect the
presence of a softer thermal component, that we associate with the emission
from an accretion disk truncated at a distance from the pulsar of 50-115 R.
From these estimates, we derive the magneto-spheric radius for disk accretion
to be 0.2 times the classical Alfv\'en radius for radial accretion.Comment: Accepted for publication in MNRA
On the taxonomy of some neotropical species of jumping spiders described by Caporiacco (Araneae, Salticidae)
Sustainable development city-beach in Alicante
[EN] Tourism development in recent decades has involved a large urban development in coastal areas, with different anthropogenic structural interventions on the coast such as the construction of commercial buildings and marinas, which has led to intense erosion and large imbalances in the last century. This situation also affects the city of Alicante, with the area between the port of Alicante and the Huertas Cape, one of the most depressed areas of the city, due to various actions carried out since the 70s, for anthropic example fillers for building marinas, jetties and broken in poor condition because they are made of sandstone, and a bad connection between the two parts of the city. In this work the creation of a new promenade that communicates both zones is proposed, creating new beaches eliminating anthro- pogenic fillings and the remains of breakwaters along the coast, the union of diverse marine area in one marina, and the insertion of an artificial reef multipurpose. With all this it is to improve the attraction of the area, and increase the mobility of the city on the coast.Aragonés, L.; García-Barba, J.; Villacampa, Y.; López, I.; Gómez Martín, ME.; Pagán, J. (2017). Sustainable development city-beach in Alicante. International Journal of Sustainable Development and Planning. 12(4):704-712. doi:10.2495/SDP-V12-N4-704-712S70471212
GROJ1744−28: an intermediate B-field pulsar in a low-mass X-ray binary
The bursting pulsar, GROJ1744−28, went again in outburst after ∼18yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3d later, thus covering the 1.3-70.0keV band. The spectrum shows a complex continuum shape that cannot be modelled with standard high-mass X-ray pulsar models, nor by two-components models. We observe broad-band and peaked residuals from 4 to 15keV, and we propose a self-consistent interpretation of these residuals, assuming they are produced by cyclotron absorption features and by a moderately smeared, highly ionized, reflection component. We identify the cyclotron fundamental at ∼4.7keV, with hints for two possible harmonics at ∼10.4 and ∼15.8keV. The position of the cyclotron fundamental allows an estimate for the pulsar magnetic field of (5.27±0.06)×1011G, if the feature is produced at its surface. From the dynamical and relativistic smearing of the disc reflected component, we obtain a lower limit estimate for the truncated accretion disc inner radius (≳100Rg) and for the inclination angle (18°-48°). We also detect the presence of a softer thermal component that we associate with the emission from an accretion disc truncated at a distance from the pulsar of 50-115Rg. From these estimates, we derive the magnetospheric radius for disc accretion to be ∼0.2times the classical Alfvén radius for radial accretio
Microtubules in Bacteria: Ancient Tubulins Build a Five-Protofilament Homolog of the Eukaryotic Cytoskeleton
Microtubules play crucial roles in cytokinesis, transport, and motility, and are therefore superb targets for anti-cancer drugs. All tubulins evolved from a common ancestor they share with the distantly related bacterial cell division protein FtsZ, but while eukaryotic tubulins evolved into highly conserved microtubule-forming heterodimers, bacterial FtsZ presumably continued to function as single homopolymeric protofilaments as it does today. Microtubules have not previously been found in bacteria, and we lack insight into their evolution from the tubulin/FtsZ ancestor. Using electron cryomicroscopy, here we show that the tubulin homologs BtubA and BtubB form microtubules in bacteria and suggest these be referred to as “bacterial microtubules” (bMTs). bMTs share important features with their eukaryotic counterparts, such as straight protofilaments and similar protofilament interactions. bMTs are composed of only five protofilaments, however, instead of the 13 typical in eukaryotes. These and other results suggest that rather than being derived from modern eukaryotic tubulin, BtubA and BtubB arose from early tubulin intermediates that formed small microtubules. Since we show that bacterial microtubules can be produced in abundance in vitro without chaperones, they should be useful tools for tubulin research and drug screening
Overview of the Role for Calreticulin in the Enhancement of Wound Healing through Multiple Biological Effects
Calreticulin (CRT), an intracellular chaperone protein crucial for the proper folding and transport of proteins through the endoplasmic reticulum, has more recent acclaim as a critical regulator of extracellular functions, particularly in mediating cellular migration and as a requirement for phagocytosis of apoptotic cells. Consistent with these functions, we show that the topical application of CRT has profound effects on the process of wound healing by causing a dose-dependent increase in epithelial migration and granulation tissue formation in both murine and porcine normal and impaired animal models of skin injury. These effects of CRT are substantiated, in vitro, as we show that CRT strongly induces cell migration/wound closure of human keratinocytes and fibroblasts, using a wound/scratch plate assay, and stimulates cellular proliferation of human keratinocytes, fibroblasts, and vascular endothelial cells, providing mechanistic insight into how CRT functions in repair. Similarly, in both animal models, the histology of the wounds show marked proliferation of basal keratinocytes and dermal fibroblasts, dense cellularity of the dermis with notably increased numbers of macrophages and well-organized collagen fibril deposition. Thus, CRT profoundly affects the wound healing process by recruiting cells essential for repair into the wound, stimulating cell growth, and increasing extracellular matrix production
New 1-aryl-3-substituted propanol derivatives as antimalarial agents
This paper describes the synthesis and in vitro antimalarial activity against a P.
falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of
the tested compounds showed an IC50 lower than 1 μM. These compounds were also tested
for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated
for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited
more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was
performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data
indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic
option for the treatment of malaria
Diversity of small land mammals in a subtropical Atlantic forest in the western region of the state of Santa Catarina, southern Brazil
Association Between the Use of a Mobile Health Strategy App and Biological Changes in Breast Cancer Survivors: Prospective Pre-Post Study
The objectives of this study were to: (1) check whether it is feasible to find changes in inflammation biomarkers
through an mHealth strategy app as a delivery mechanism of an intervention to monitor energy balance; and (2) discover potential
predictors of change of these markers in breast cancer survivors (BCSs). Analyzing changes in inflammatory biomarker concentrations after using the mHealth app, differences between
preassessment CRP (4899.04 pg/ml; SD 1085.25) and IL-6 (87.15 pg/ml; SD 33.59) and postassessment CRP (4221.24 pg/ml;
SD 911.55) and IL-6 (60.53 pg/ml; SD 36.31) showed a significant decrease in both markers, with a mean difference of –635.25
pg/ml (95% CI –935.65 to –334.85; P<.001) in CRP and –26.61 pg/ml (95% CI –42.51 to –10.71; P=.002) in IL-6. Stepwise
regression analyses revealed that changes in global quality of life, as well as uMARS score and hormonal therapy, were possible predictors of change in CRP concentration after using the mHealth app. In the same way, the type of tumor removal surgery
conducted, as well as changes in weight and pain score, were possible predictors of change in IL-6 concentration after using the
app. In conclusion, through the results of this study, we hypothesize that there is a possible association between an
mHealth energy balance monitoring strategy and biological changes in BCSs. These changes could be explained by different
biopsychosocial parameters, such as the use of the application itself, quality of life, pain, type of tumor removal surgery, hormonal
treatment or obesity.The study was funded by the Spanish Ministry of Economy and Competitiveness (Plan Estatal de I+D+I 2013-2016), Fondo de
Investigación Sanitaria del Instituto de Salud Carlos III (PI14/01627), Fondos Estructurales de la Unión Europea (FEDER), and
by the Spanish Ministry of Education (FPU14/01069 and FPU17/00939)
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