Estudio sobre Flebotomineos en Araracuara Caquetá, Colombia S.A Incluyendo la descripción de Lutzomyia Araracuarensis (Diptera, Psychodidae)

During July and August 1977, in an Amazonian rain forest area of about 1 km2 near the settlement of Araracuara, Caqueta, Colombia, Sur America, a survey of the phlebotomine sandfly fauna was carried out, using several methods of collection (Shannon traps, light traps, human bait catches and manual catches of resting sandflies with aspirators). Thirty five species of Lutzomyia were encountered (2.145 and 2.903), of which 6 species were new records for Colombia and one a new species which is described from 23 male specimens as Lutzomyia araracuarensis sp. nov. and is allocated to the Gasparviannai group. The female of Lutzomyia wagleyi (longispina group) is described for the first time. Males and females of two apparently unknown species are described and provisionally designated as Lutzomyia sp. No. 1, Araracuara, and Lu. sp.No. 2, Araracuara: Lu. sp. No. 1 is allocated to the subgenus Trichophoramyia and Lu. sp. No. 2 to the oswaldoi group. Twenty four female sandflies (5 species) were infested with mites which were identified variously to the family or generic level.Durante julio y agosto de 1977. en un área de cerca de 1 km2 de bosque lluvioso tropical de la Amazonía, cerca de la localidad de Araracuara. Caquetá, Colombia, se hizo un estudio de la fauna de flebotomíneos, usando varios métodos de captura (trampa Shannon, trampa de luz, cebo humano y captura manual de flebotomíneos con aspiradores en los sitios de reposo). 35 especies de Lutzomyia fueron encontradas (2.145 22 y 2.903), de las cuales 6 especies fueron nuevos registros para Colombia y una, nueva especie, la cual es descrita a partir de 23 ejemplares machos, como Lutzomyia araracuarensis sp. nov. y colocada en el grupo Gasparviannai. La hembra de Lu. wagleyi (grupo longispinal es descrita por la primera vez. Se describen ademas machos y hembras de dos aparentemente desconocidas especies y provisionalmente se nominan como Lutzomyia sp. No. 1 de Araracuara. y Lu. sp. No. 2 de Araracuara; Lu. sp. No. 1 es colocada en el subghnero Trichophoromyia y Lu. sp. No. 2 en el grupo Oswaldoi. Veinticuatro hembras de flebotomineos (5 especies) estaban infestadas con ácaros los cuales fueron identificados hasta nivel de familia o género

Simultaneous Multi-band Radio & X-ray Observations of the Galactic Center Magnetar SGR 1745−-2900

We report on multi-frequency, wideband radio observations of the Galactic Center magnetar (SGR 1745$-$2900) with the Green Bank Telescope for $\sim$100 days immediately following its initial X-ray outburst in April 2013. We made multiple simultaneous observations at 1.5, 2.0, and 8.9 GHz, allowing us to examine the magnetar's flux evolution, radio spectrum, and interstellar medium parameters (such as the dispersion measure (DM), the scattering timescale and its index). During two epochs, we have simultaneous observations from the Chandra X-ray Observatory, which permitted the absolute alignment of the radio and X-ray profiles. As with the two other radio magnetars with published alignments, the radio profile lies within the broad peak of the X-ray profile, preceding the X-ray profile maximum by $\sim$0.2 rotations. We also find that the radio spectral index $\gamma$ is significantly negative between $\sim$2 and 9 GHz; during the final $\sim$30 days of our observations $\gamma \sim -1.4$, which is typical of canonical pulsars. The radio flux has not decreased during this outburst, whereas the long-term trends in the other radio magnetars show concomitant fading of the radio and X-ray fluxes. Finally, our wideband measurements of the DMs taken in adjacent frequency bands in tandem are stochastically inconsistent with one another. Based on recent theoretical predictions, we consider the possibility that the dispersion measure is frequency-dependent. Despite having several properties in common with the other radio magnetars, such as $L_{\textrm{X,qui}}/L_{\textrm{rot}} \lesssim 1$, an increase in the radio flux during the X-ray flux decay has not been observed thus far in other systems.Comment: 15 pages, 9 figures, 3 tables; accepted to Ap

A 42.3-43.6 GHz spectral survey of Orion BN/KL: First detection of the v=0 J=1-0 line from the isotopologues 29SiO and 30SiO

We have surveyed molecular line emission from Orion BN/KL from 42.3 to 43.6 GHz with the Green Bank Telescope. Sixty-seven lines were identified and ascribed to 13 different molecular species. The spectrum at 7 mm is dominated by SiO, SO2, CH3OCH3, and C2H5CN. Five transitions have been detected from the SiO isotopologues 28SiO, 29SiO, and 30SiO. We report here for the first time the spectra of the 29SiO and 30SiO v=0 J=1-0 emission in Orion BN/KL, and we show that they have double-peaked profiles with velocity extents similar to the main isotopologue. The main motivation for the survey was the search of high-velocity (100-1000 km/s) outflows in the BN/KL region as traced by SiO Doppler components. Some of the unidentified lines in principle could be high-velocity SiO features, but without imaging data their location cannot be established. Wings of emission are present in the v=0 28SiO, 29SiO and 30SiO profiles, and we suggest that the v=0 emission from the three isotopologues might trace a moderately high-velocity (~30-50 km/s) component of the flows around the high-mass protostar Source I in the Orion BN/KL region. We also confirm the 7 mm detection of a complex oxygen-bearing species, acetone (CH3COCH3), which has been recently observed towards the hot core at 3 mm, and we have found further indications of the presence of long cyanopolyynes (HC5N and HC7N) in the quiescent cold gas of the extended ridge.Comment: 27 pages, 3 figures, accepted by Ap

A strongly magnetized pulsar within grasp of the Milky Way's supermassive black hole

The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A*. Young, massive stars within 0.5 pc of SgrA* are evidence of an episode of intense star formation near the black hole a few Myr ago, which might have left behind a young neutron star traveling deep into SgrA*'s gravitational potential. On 2013 April 25, a short X-ray burst was observed from the direction of the Galactic center. Thanks to a series of observations with the Chandra and the Swift satellites, we pinpoint the associated magnetar at an angular distance of 2.4+/-0.3 arcsec from SgrA*, and refine the source spin period and its derivative (P=3.7635537(2) s and \dot{P} = 6.61(4)x10^{-12} s/s), confirmed by quasi simultaneous radio observations performed with the Green Bank (GBT) and Parkes antennas, which also constrain a Dispersion Measure of DM=1750+/-50 pc cm^{-3}, the highest ever observed for a radio pulsar. We have found that this X-ray source is a young magnetar at ~0.07-2 pc from SgrA*. Simulations of its possible motion around SgrA* show that it is likely (~90% probability) in a bound orbit around the black hole. The radiation front produced by the past activity from the magnetar passing through the molecular clouds surrounding the Galactic center region, might be responsible for a large fraction of the light echoes observed in the Fe fluorescence features.Comment: ApJ Letters in pres

The adequacy of Hepato‐Pancreato‐Biliary training: how closely do perceptions of fellows and programme directors align?

BackgroundHepatopancreatobiliary fellowship programmes have recently undergone significant changes with regards to training standards, case‐volume thresholds and multimodality educational platforms. The goals of this study were to compare the perspectives of fellows and programme directors (PDs) on perceptions of readiness to enter practice and identify core Hepato‐Pancreato‐Biliary (HPB) procedures that require increased emphasis during training.MethodsThis survey targeted PDs and trainees participating in the Fellowship Council/AHPBA pathway. Data related to demographics, education and career plans were collected. Analysis of PD and fellow opinions regarding their confidence to perform core HPB procedures was completed.ResultsThe response rate was 88% for both fellows (21/24) and PDs (23/26). There was good agreement between PDs and fellows in the perception of case volumes. Select differences where PDs ranked higher perceptions included major hepatectomies (PDs: 87% versus fellows: 57%, P = 0.04), pancreaticoduodenectomies (100% versus 81%, P = 0.04) and laparoscopic distal pancreatectomies (78% versus 43%, P = 0.03). ‘Good or excellent’ case volumes translated into increased fellow readiness, except for some pancreatitis procedures, laparoscopic distal pancreatectomies and potentially major hepatectomies.ConclusionsThis study provides insight into content domains that may require additional attention to achieve an appropriate level of proficiency and confidence upon completion of training.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113116/1/hpb12457.pd

On Pulsar Distance Measurements and their Uncertainties

Accurate distances to pulsars can be used for a variety of studies of the Galaxy and its electron content. However, most distance measures to pulsars have been derived from the absorption (or lack thereof) of pulsar emission by Galactic HI gas, which typically implies that only upper or lower limits on the pulsar distance are available. We present a critical analysis of all measured HI distance limits to pulsars and other neutron stars, and translate these limits into actual distance estimates through a likelihood analysis that simultaneously corrects for statistical biases. We also apply this analysis to parallax measurements of pulsars in order to obtain accurate distance estimates and find that the parallax and HI distance measurements are biased in different ways, because of differences in the sampled populations. Parallax measurements typically underestimate a pulsar's distance because of the limited distance to which this technique works and the consequential strong effect of the Galactic pulsar distribution (i.e. the original Lutz-Kelker bias), in HI distance limits, however, the luminosity bias dominates the Lutz-Kelker effect, leading to overestimated distances because the bright pulsars on which this technique is applicable are more likely to be nearby given their brightness.Comment: 32 pages, 1 figure, 2 tables; Accepted for publication in the Astrophysical Journa

The Fine Structure Lines of Hydrogen in HII Regions

The 2s_{1/2} state of hydrogen is metastable and overpopulated in HII regions. In addition, the 2p states may be pumped by ambient Lyman-alpha radiation. Fine structure transitions between these states may be observable in HII regions at 1.1 GHz (2s_{1/2}-2p_{1/2}) and/or 9.9 GHz (2s_{1/2}-2p_{3/2}), although the details of absorption versus emission are determined by the relative populations of the 2s and 2p states. The n=2 level populations are solved with a parameterization that allows for Lyman-alpha pumping of the 2p states. The density of Lyman-alpha photons is set by their creation rate, easily determined from the recombination rate, and their removal rate. Here we suggest that the dominant removal mechanism of Lyman-alpha radiation in HII regions is absorption by dust. This circumvents the need to solve the Lyman-alpha transfer problem, and provides an upper limit to the rate at which the 2p states are populated by Lyman-alpha photons. In virtually all cases of interest, the 2p states are predominantly populated by recombination, rather than Lyman-alpha pumping. We then solve the radiative transfer problem for the fine structure lines in the presence of free-free radiation. In the likely absence of Lyman-alpha pumping, the 2s_{1/2}-2p_{1/2} lines will appear in stimulated emission and the 2s_{1/2}-2p_{3/2} lines in absorption. Searching for the 9.9 GHz lines in high emission measure HII regions offers the best prospects for detection. The lines are predicted to be weak; in the best cases, line-to-continuum ratios of several tenths of a percent might be expected with line strengths of tens to a hundred mK with the Green Bank Telescope.Comment: 18 pages, 2 figures, accepted by ApJ, references added, typos correcte

Reduced free asparagine in wheat grain resulting from a natural deletion of TaASNB2: investigating and exploiting diversity in the asparagine synthetase gene family to improve wheat quality

Background: Understanding the determinants of free asparagine concentration in wheat grain is necessary to reduce levels of the processing contaminant acrylamide in baked and toasted wheat products. Although crop management strategies can help reduce asparagine levels, breeders have limited options to select for genetic variation underlying this trait. Asparagine synthetase enzymes catalyse a critical step in asparagine biosynthesis in plants and, in wheat, are encoded by five homeologous gene triads that exhibit distinct expression profiles. Within this family, TaASN2 genes are highly expressed during grain development but TaASN-B2 is absent in some varieties. Results: Natural genetic diversity in the asparagine synthetase gene family was assessed in different wheat varieties revealing instances of presence/absence variation and other polymorphisms, including some predicted to affect the function of the encoded protein. The presence and absence of TaASN-B2 was determined across a range of UK and global common wheat varieties and related species, showing that the deletion encompassing this gene was already present in some wild emmer wheat genotypes. Expression profiling confirmed that TaASN2 transcripts were only detectable in the grain, while TaASN3.1 genes were highly expressed during the early stages of grain development. TaASN-A2 was the most highly expressed TaASN2 homeologue in most assayed wheat varieties. TaASN-B2 and TaASN-D2 were expressed at similar, lower levels in varieties possessing TaASN-B2. Expression of TaASN-A2 and TaASN-D2 did not increase to compensate for the absence of TaASN-B2, so total TaASN2 expression was lower in varieties lacking TaASN-B2. Consequently, free asparagine levels in field-produced grain were, on average, lower in varieties lacking TaASN-B2, although the effect was lost when free asparagine accumulated to very high levels as a result of sulphur deficiency. Conclusions: Selecting wheat genotypes lacking the TaASN-B2 gene may be a simple and rapid way for breeders to reduce free asparagine levels in commercial wheat grain