Multi-wavelength properties of IGR J05007-7047 (LXP 38.55) and identification as a Be X-ray binary pulsar in the LMC

We report on the results of a $\sim$40 d multi-wavelength monitoring of the Be X-ray binary system IGR J05007-7047 (LXP 38.55). During that period the system was monitored in the X-rays using the Swift telescope and in the optical with multiple instruments. When the X-ray luminosity exceeded $10^{36}$ erg/s we triggered an XMM-Newton ToO observation. Timing analysis of the photon events collected during the XMM-Newton observation reveals coherent X-ray pulsations with a period of 38.551(3) s (1 {\sigma}), making it the 17$^{th}$ known high-mass X-ray binary pulsar in the LMC. During the outburst, the X-ray spectrum is fitted best with a model composed of an absorbed power law ($\Gamma =0.63$) plus a high-temperature black-body (kT $\sim$ 2 keV) component. By analysing $\sim$12 yr of available OGLE optical data we derived a 30.776(5) d optical period, confirming the previously reported X-ray period of the system as its orbital period. During our X-ray monitoring the system showed limited optical variability while its IR flux varied in phase with the X-ray luminosity, which implies the presence of a disk-like component adding cooler light to the spectral energy distribution of the system.Comment: 11 pages, 11 figures, Accepted for publication in MNRA

Covert contraceptive use among women attending a reproductive health clinic in a municipality in Ghana.

BACKGROUND: Covert contraceptive use (CCU) in sub-Saharan Africa is an indication of women's inability to exercise autonomy in their reproductive choices. The aim of this study was to assess the prevalence and determinants of CCU among a sample of FP clients in a municipality of Ghana. METHODS: We conducted a mixed method study among women attending a public reproductive health clinic in Sunyani, a city of over 250,000 inhabitants in Ghana. An initial survey inquired into sociodemographic characteristics, use of family planning (FP) methods and partner awareness of contraceptive use. The predictors of CCU were explored using logistic regressions. We used the findings to develop a guide which we applied in-depth interviews and focus group discussions with attendants at the same facility. Qualitative data analysis was conducted using a framework approach. RESULTS: We interviewed 300 women, 48 % of whom were aged between 26-33 years. The injectable was the most widely used method (56 %). The prevalence of CCU was 34 %. In multivariate analysis, single women were more likely to practice CCU than married or co-habiting women (Adjusted OR = 12.12, 95 % C.I. 4.73-31.1). Muslim and traditionalist women were similarly more likely to practice CCU than non-Muslim, non-traditionalist (Adjusted OR = 4.56, 2.29-9.06). Women who preferred to have their first or next child in 4 or more years from the time of the interview were more likely to be in CCU than women who intended to have children within 4 years of the interview (2.57; 1.37-4.83). Single women saw in covert use a statement of their social autonomy. To succeed in CCU, women wished that clinic attendance cards would not be given to them to keep at home. Though many participants saw in CCU a source of anxiety, they expected health workers to consider it and uphold confidentiality in the provision of services. CONCLUSIONS: Covert contraceptive use was high in this municipality and being single was the strongest predictor of the practice. Providers of FP services should reflect on how to adequately address the challenges faced by women who practice CCU

Possible coupling between climatically induced lake level change, volcanic eruptions and seismotectonic activation in the Rukwa-Rungwe-Nyasa rift, SW Tanzania

The Rukwa rift basin is presently a closed hydrogeological depression containing a shallow lake (max 20 me deep) with its surface at an altitude around 810 m above sea level. Lacustrine terraces and paleo-shorelines are known up to 980 m above sea level, an altitude at which it reach the overflow sill towards Lake Tanganyika. Both Lakes Tanganyika and Nyasa (Malawi) are presently overflowing, but as their lake level fluctuates, they have been disconnected from their outlet in the recent past. High resolution seismic profiling in both Lakes Rukwa and Malawi has show the presence of active fault systems underneath the lake floor. Some of these fault systems appear to have had a cyclic activity, with alternating periods of high tectonic activity/sedimentation and periods of tectonic quiescence. The accommodation zone between Lake Rukwa and Nyasa is occupied by the Rungwe volcanic Province, with the Ngozi, Rungwe and Kiejo volcanoes presenting signs of recent volcanic activity. The Rungwe Province is cross-cut by several directions of faults, which clearly control the location of the volcanic vents.In our work, we reviewed the available data on recent (Late Pleistocene – Holocene) volcanic eruptions, in the Rungwe area itself, in the drill cores from the surrounding lakes and from aerial observations up to 300 km away from the Rungwe Province. We performed morphotectonic and paleoseismic investigations of the Kanda fault, a major normal fault between lakes Rukwa and Tanganyika. We investigated lacustrine deposits of the Rukwa basin corresponding to the two last cycles of high lake level. The chronological framework was established using 30 new radiocarbon dating and the most prominent volcanic tephra layers were used as a reference in the correlations. The results are still preliminary, but a good correlation already appear between climatically induced lake level change (in Lake Rukwa), seismo-tectonic activation of the regional fault network (underneath Lake Rukwa and the Kanda fault between Lakes Rukwa and Tanganyika) and the timing of the recent strong volcanic eruptions in the Rungwe Volcanic Province since the last 40.000 years. This relation is explained taking into account that Lake Rukwa is very sensitive to climate change as it occupies a flat depression and its overflow outlet is 180 m above its present-day level. Its lake level rises rapidly when the climate becomes more humid as it was the case during the Last Glacial Maximum and during the Younger Dryas event. Increase in lake level means increasing of the load in the basin and perturbation of the ambient tectonic stresses. In most of the Rukwa rift, the tectonic stress is of extensional (normal faulting) regime, with the maximum principal stress axis (sigma 1) subvertical. In these conditions, increasing the vertical load will increase the shear stress on the existing normal faults, triggering (seismogenic) normal faulting deformation. As the architecture of the active volcanoes in the Rungwe Province is tectonically controlled, activation of the faults, together with a greater pressure of water in the tectonic discontinuities are likely to trigger large volcanic eruptions, strongly explosive

Super-solar metallicity at the position of the ultra-long GRB130925A

Over the last decade there has been immense progress in the follow-up of short and long GRBs, resulting in a significant rise in the detection rate of X-ray and optical afterglows, in the determination of GRB redshifts, and of the identification of the underlying host galaxies. Nevertheless, our theoretical understanding on the progenitors and central engines powering these vast explosions is lagging behind, and a newly identified class of `ultra-long' GRBs has fuelled speculation on the existence of a new channel of GRB formation. In this paper we present high signal-to-noise X-shooter observations of the host galaxy of GRB130925A, which is the fourth unambiguously identified ultra-long GRB, with prompt gamma-ray emission detected for ~20ks. The GRB line of sight was close to the host galaxy nucleus, and our spectroscopic observations cover both this region along the bulge/disk of the galaxy, in addition to a bright star-forming region within the outskirts of the galaxy. From our broad wavelength coverage we obtain accurate metallicity and dust-extinction measurements at both the galaxy nucleus, and an outer star-forming region, and measure a super-solar metallicity at both locations, placing this galaxy within the 10-20% most metal-rich GRB host galaxies. Such a high metal enrichment has implications on the progenitor models of both long and ultra-long GRBs, although the edge-on orientation of the host galaxy does not allow us to rule out a large metallicity variation along our line of sight. The spatially resolved spectroscopic data presented in this paper offer important insight into variations in the metal and dust abundance within GRB host galaxies. They also illustrate the need for IFU observations on a larger sample of GRB host galaxies at varies metallicities to provide a more quantitative view on the relation between the GRB circumburst and the galaxy-whole properties.Comment: 9 pages, 3 figures, A&A in press, matches published versio

Immediate early protein of equid herpesvirus type 1 as a target for cytotoxic T-lymphocytes in the thoroughbred horse

Cytotoxic T-lymphocytes (CTLs) are associated with protective immunity against disease caused by equid herpesvirus type 1 (EHV-1). However, the EHV-1 target proteins for CTLs are poorly defined. This limits the development of vaccine candidates designed to stimulate strong CTL immunity. Here, classical CTL assays using lymphocytes from horses of three defined MHC class I types that experienced natural infection with EHV-1 and a modified vaccinia virus construct containing an EHV-1 gene encoding the immediate-early (IE) protein are reported. Horses homozygous for the equine leukocyte antigen (ELA)-A2 haplotype, but not the ELA-A5 haplotype, produced MHC-restricted CTL responses against the IE protein. Previously, horses homozygous for the ELA-A3 haplotype also mounted CTL responses against the IE protein. Both haplotypes are common in major horse breeds, including the Thoroughbred. Thus, the IE protein is an attractive candidate molecule for future studies of T-cell immunity to EHV-1 in the horse

The “invisible cholecystectomy”: A transumbilical laparoscopic operation without a scar

Background Looking to further reduce the operative trauma of laparoscopic cholecystectomy, we developed, in patients with no history of cholecystitis and a normal BMI, a scarless operation through the umbilicus. The operative technique, along with the results of the first 10 patients operated in this way, are fully described. Methods 10 female patients underwent transumbilical scarless laparoscopic cholecystectomy. Through the umbilicus, two trocars of 5 mm were introduced parallel to another with a bridge of fascia between them (one for the 5-mm laparoscope and the other for the grasper). With the help of one 1-mm Kirschner wire, introduced at the subcostal line and bent with a special designed device, the gallbladder was pulled up and the triangle of Callot was dissected free, clipped, cut, and the gallbladder was subsequently resected. Finally the gallbladder was taken out through the umbilicus and the umbilicus reconstructed. Results 10 female patients, mean age 36 years (range: 31–49), mean body mass index (BMI) 23 (range: 20–26), after one attack (six patients) or a second attack (four patients) and cholelithiasis confirmed by ultrasonography with no suspicion of inflammation were included in this preliminary study. Mean operative time was 70 minutes (range: 65–85) with no conversions; hospital stay was less than 24 hours with no complications. Conclusion Looking to reduce operative trauma and improve the cosmetic result following laparoscopic cholecystectomy, a transumbilical operative technique has been developed. Results of the operative procedure in a selected group of patients are encouraging with no signs of inflammation and normal BMI. The umbilicus can be developed as a natural port for performing various operative procedures with the help of the traction produced by thin Kirschner wires

Non-intersecting squared Bessel paths: critical time and double scaling limit

We consider the double scaling limit for a model of $n$ non-intersecting squared Bessel processes in the confluent case: all paths start at time $t=0$ at the same positive value $x=a$, remain positive, and are conditioned to end at time $t=1$ at $x=0$. After appropriate rescaling, the paths fill a region in the $tx$--plane as $n\to \infty$ that intersects the hard edge at $x=0$ at a critical time $t=t^{*}$. In a previous paper (arXiv:0712.1333), the scaling limits for the positions of the paths at time $t\neq t^{*}$ were shown to be the usual scaling limits from random matrix theory. Here, we describe the limit as $n\to \infty$ of the correlation kernel at critical time $t^{*}$ and in the double scaling regime. We derive an integral representation for the limit kernel which bears some connections with the Pearcey kernel. The analysis is based on the study of a $3\times 3$ matrix valued Riemann-Hilbert problem by the Deift-Zhou steepest descent method. The main ingredient is the construction of a local parametrix at the origin, out of the solutions of a particular third-order linear differential equation, and its matching with a global parametrix.Comment: 53 pages, 15 figure

Earthquake geology of the Kanda fault system (Tanganyika-Rukwa rift, SW highlands of Tanzania)

The 160 km-long Kanda normal fault system is running longitudinally across the Ufipa tilted horst between the Tanganyika and Rukwa rift basins in the western branch of the East African Rift System. It is likely to have been affected the Ms 7.4 earthquake in 1910 whose instrumental epicentre was located approximately near Sumbawanga town, along the northern portion of the fault. Remote sensing, morphotectonic, and palaeoseismological investigations together with structural geology and electric resistivity profiling allow to characterise the main seismological parameters of this major active fault.In order to reconstruct the along-trend displacement profile and fault segmentation, topographic profiles were made across the fault scarp using data from differential GPS, Hand GPS and the 90 m resolution STRM DEM. Comparison of topographic profiles from the same site using the different topographic data provides some insight on the methodology and validity of topographic profiles extraction. Due to the large dimensions of the fault scarp (10-30 m high) the strong magnitude of the potential earthquakes (Ms. 7.5) and the large associated co-seismic slip (2-4 m), classical paleoseismic trenching is difficult to apply. Instead, we used existing exposures such as natural trenches, road cuts and outcrops, supplemented by a dense topographic survey (5000 points on differential GPS over less than 1 km2) to produce a 2 m resolution digital elevation model, performed detailed geological mapping, airphoto interpretation, electric resistivity profiling, small drillings, and C14 dating. Efforts were concentrated on a promising site where river sediments and peat deposits are interbedded with volcanic tephra layers and largely exposed on the footwall. Results show that the Kanda fault had different cycles of activity, separated by tectonically quite periods. The last period of activity probably started by 11 cal Ka BP, soon after the deposition of a marked tephra layer, but sedimentation on the footwall continued up to 5 Ka cal BP. Since then, the minimum offset is estimated at 17.9 m, which gives a minimum slip rate of 3.58 mm/year, of an equivalent of one earthquakes generating 3.58 m slip per 1000 years (Ms in the range of 7.0 - 7.5)

Surface ruptures associated to the July-August 2007 Gelai volcano-tectonic event, North Tanzania

A seismic crisis with a series of moderate earthquakes started on July 12th 2007 in the Natron area in North Tanzania. According to the USGS-NEIC earthquake catalogue, it lasted up to the 8th of September and 80 teleseismic earthquakes were recorded, with the strongest one on July 17th (Mw 5.9). Soon after the main event of July 17th, the presence of open surface fissures was reported on the ground, on the southern flank of the recent (th event shows the presence of two surface fracture systems delimiting a NNE-trending narrow graben in the southern flank of the Gelai volcano. These features were subsequently mapped in relative detail in the field in October 2007 before the following rain season. They turn to be subvertical open fissures, arranged in en-échelon way and displaying horizontal dilation as well as vertical offset. They are interpreted to evolve at depth into 60-75° dipping normal fault systems. According to their calculated dip, these fault systems converge at depth where they should either merge or intersect. Assuming a 50 m high vertical portion for the open fracture, the depth and horizontal coordinates of the fault intersection point are calculated for a series of profiles drawn across the graben structure.It is suspected that the July-August moderate-magnitude earthquake swam crisis might correspond to a volcano-tectonic event during which a magmatic dyke was injected at depth under the southern flank of the Gelai volcano. In this scenario, the observed graben structure bounded by the open fracture network and the inferred normal faults at depth are similar to the volcano-extensional structures that commonly form in the upper crust above a thin subvertical dyke injection. The top of this inferred dyke should correspond approximately to the intersection of the lines prolonging the two normal faults (even if physically the faults did not join the top of dyke), with an average depth of 4000m under the topographic surface