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The distance to a star forming region can be determined by measuring the proper motions within H2O maser clusters. If the motions of the maser spots are random, the distance can be determined by applying the technique known as statistical parallax. Alternatively, if organized motions are evident in the proper motions, one can model the source to estimate its the distance. Both methods rely on a comparison of the radial component of the motion (in km/s) and the proper motion on the plane of the sky (in milli-arcseconds/year).
We report preliminary results of a long term spectral line VLBI experiment to observe internal proper motions of water maser sources in the vicinity of newly formed stars. This technique yields a picture of the three-dimensional kinematics of the region and a measure of the distance to the source. First results from the galactic center source SGR B2 are presented.
Using the IRAM interferometer we have mapped HCN(1 → 0), HCO+(1 → 0), and 3.5 mm continuum emission from Arp 220, the prototype infrared ultraluminous galaxy. The extended molecular emission and velocity gradient are aligned with the optical dust lane. The HCN and HCO+ lines are exceptionally strong, suggesting a connection between the dense molecular gas they trace and Arp 220's enhanced infrared emission. The inferred gas density and filling factor imply the nucleus of Arp 220 may be a giant molecular cloud.
Hemihedrite from the Florence Lead-Silver mine in Pinal County, Arizona, USA
was first described and assigned the ideal chemical formula
based upon a variety of chemical and crystal-structure analyses. The primary
methods used to determine the fluorine content for hemihedrite were
colorimetry, which resulted in values of F that were too high and
inconsistent with the structural data, and infrared (IR) spectroscopic
analysis that failed to detect OH or H2O. Our reinvestigation
using electron microprobe analysis of the type material, and additional
samples from the type locality, the Rat Tail claim, Arizona, and Nevada,
reveals the absence of fluorine, while the presence of OH is confirmed by
Raman spectroscopy. These findings suggest that the colorimetric
determination of fluorine in the original description of hemihedrite
probably misidentified F due to the interferences from PO4 and
SO4, both found in our chemical analyses. As a consequence of
these results, the study presented here proposes a redefinition of the
chemical composition of hemihedrite to the ideal chemical formula
Hemihedrite is isotypic with iranite with substitution of Zn for Cu, and
raygrantite with substitution of Cr for S. Structural data from a sample
from the Rat Tail claim, Arizona, indicate that hemihedrite is triclinic in
space group P1, a = 9.4891(7),
b = 11.4242(8), c = 10.8155(7) Å, α =
120.368(2)°, β = 92.017(3)°, γ = 55.857(2)°, V = 784.88(9)
Å3, Z= 1, consistent with previous
investigations. The structure was refined from singlecrystal X-ray
diffraction data to R1 = 0.022 for 5705 unique observed reflections, and the ideal
was assumed during the refinement. Electron microprobe analyses of this
sample yielded the empirical chemical formula
6.00 Si1.97O34H2.16 based on 34 O
atoms and six (Cr + S + P) per unit cell.
Free-range laying hen systems are increasing within Australia. The pullets for these systems are typically reared indoors before being provided first range access around 21 to 26 weeks of age. Thus, the rearing and laying environments are disparate and hens may not adapt well to free-range housing. In this study, we reared 290 Hy-Line® Brown day-old chicks divided into two rooms each with feed, water and litter. In the enriched room, multiple structural, manipulable, visual and auditory stimuli were also provided from 4 to 21 days, the non-enriched room had no additional objects or stimuli. Pullets were transferred to the laying facility at 12 weeks of age and divided into six pens (three enriched-reared, three non-enriched-reared) with identical indoor resources and outdoor range area. All birds were first provided range access at 21 weeks of age. Video observations of natural disturbance behaviours on the range at 22 to 23 and 33 to 34 weeks of age showed no differences in frequency of disturbance occurrences between treatment groups (P=0.09) but a decrease in disturbance occurrences over time (P<0.0001). Radio-frequency identification tracking of individually tagged birds from 21 to 37 weeks of age showed enriched birds on average, spent less time on the range each day (P<0.04) but with a higher number of range visits than non-enriched birds from 21 to 24 weeks of age (P=0.01). Enriched birds accessed the range on more days (P=0.03) but over time, most birds in both treatment groups accessed the range daily. Basic external health scoring showed minimal differences between treatment groups with most birds in visibly good condition. At 38 weeks of age all birds were locked inside for 2 days and from 40 to 42 weeks of age the outdoor range was reduced to 20% of its original size to simulate stressful events. The eggs from non-enriched birds had higher corticosterone concentrations following lock-in and 2 weeks following range reduction compared with the concentrations within eggs from enriched birds (P<0.0001). Correspondingly, the enriched hens showing a greater increase in the number of visits following range area reduction compared to non-enriched hens (P=0.02). Only one rearing room per treatment was used but these preliminary data indicate 3 weeks of early enrichment had some long-term effects on hen ranging behaviour and enhanced hen’s adaptability to environmental stressors.
Hydroxycalciomicrolite, Ca1.5Ta2O6(OH) is a
new microlite-group mineral found in the Volta Grande pegmatite, Nazareno,
Minas Gerais, Brazil. It occurs as isolated octahedral and as a combination
of octahedral and rhombic dodecahedral crystals, up to1.5 mm in size. The
crystals are yellow and translucent, with a white streak and vitreous to
resinous lustre. The mineral is brittle, with a Mohs hardness of 5–6.
Cleavage is not observed and fracture is conchoidal. The calculated density
is 6.176 g cm–3. Hydroxycalciomicroliteis isotropic,
ncalc. = 2.010. The infrared and Raman spectra exhibit bands due
to O–H stretching vibrations. The chemical composition determined from
electron microprobe analysis (n = 13) is (wt.%):
Na2O 0.36(8), CaO 15.64(13), SnO2
0.26(3),Nb2O5 2.82(30), Ta2O5
78.39(22), MnO 0.12(2), F 0.72(12) and H2O 1.30 (from the crystal
structure data), O = F –0.30, total 99.31(32), yielding an empirical
is cubic, with unit-cell parameters a = 10.4205(1) Å,
V = 1131.53(2) Å3 and Z = 8.
It represents a pyrochlore supergroup, microlite-group mineral exhibiting
P4332 symmetry, instead of
Fd3m. Thereduction in symmetry is due
to long-range ordering of Ca and vacancies on the A sites.
This is the first example of such ordering in a natural pyrochlore, although
it is known from synthetic compounds. This result is promising because it
suggests that other species with P4332or
lower-symmetry space group can be discovered and characterized.
Free-range laying hen systems are increasing within Australia and research is needed to determine optimal outdoor stocking densities. Six small (n=150 hens) experimental flocks of ISA Brown laying hens were housed with access to ranges simulating one of three outdoor stocking densities with two pen replicates per density: 2000 hens/ha, 10 000 hens/ha or 20 000 hens/ha. Birds were provided daily range access from 21 to 36 weeks of age and the range usage of 50% of hens was tracked using radio-frequency identification technology. Throughout the study, basic external health assessments following a modified version of the Welfare Quality® protocol showed most birds were in visibly good condition (although keel damage was increasingly present with age) with few differences between stocking densities. Toenail length at 36 weeks of age was negatively correlated with hours spent ranging for all pens of birds (all r⩾−0.23, P⩽0.04). At 23 weeks of age, there were no differences between outdoor stocking densities in albumen corticosterone concentrations (P=0.44). At 35 weeks of age, density effects were significant (P<0.001) where the eggs from hens in the highest outdoor stocking density showed the highest albumen corticosterone concentrations, although eggs from hens in the 10 000 hens/ha density showed the lowest concentrations (P<0.017). Behavioural observations of hens both on the range and indoors showed more dust bathing and foraging (scratching followed by ground-pecking) was performed outdoors, but more resting indoors (all P<0.001). Hens from the 2000 hens/ha densities showed the least foraging on the range but the most resting outdoors, with hens from the 20 000 hens/ha densities showing the least amount of resting outdoors (all P<0.017). Proportions of dust bathing outdoors tended to differ between the stocking densities (P=0.08). For each of the health and behavioural measures there were differences between pen replicates within stocking densities. These data show outdoor stocking density has some effects on hen welfare, and it appears that consideration of both individual and group-level behaviour is necessary when developing optimal stocking density guidelines and free-range system management practices.
A distance of R0 = 7.6 ± 1.6 kpc for the galactic center is given by comparison of expansion parallax of a cluster of H2O masers in W49(N) with the kinematic distance of that source. Data from additional epochs, now being calibrated, should further improve the accuracy of our determination of R0.
Bovine tuberculosis (bTB) is an important disease of cattle caused by infection with Mycobacterium bovis, a pathogen that may be extremely difficult to eradicate in the presence of a true wildlife reservoir. Our objective was to identify and review relevant literature and provide a succinct summary of current knowledge of risk factors for transmission of infection of cattle. Search strings were developed to identify publications from electronic databases to February 2015. Abstracts of 4255 papers identified were reviewed by three reviewers to determine whether the entire article was likely to contain relevant information. Risk factors could be broadly grouped as follows: animal (including nutrition and genetics), herd (including bTB and testing history), environment, wildlife and social factors. Many risk factors are inter-related and study designs often do not enable differentiation between cause and consequence of infection. Despite differences in study design and location, some risk factors are consistently identified, e.g. herd size, bTB history, presence of infected wildlife, whereas the evidence for others is less consistent and coherent, e.g. nutrition, local cattle movements. We have identified knowledge gaps where further research may result in an improved understanding of bTB transmission dynamics. The application of targeted, multifactorial disease control regimens that address a range of risk factors simultaneously is likely to be a key to effective, evidence-informed control strategies.
Oxyspirura petrowi is a heteroxenous parasitic nematode that has been reported in high prevalences from birds in the Order Galliformes experiencing population declines in the USA. There is a paucity of information regarding the natural history O. petrowi, including the life cycle and effects of infection on wild bird populations. In order to study the life cycle of this parasite, we collected plains lubber grasshoppers (Brachystola magna) from a field location in Mitchell County, Texas. We found third-stage larvae (L3) in 37.9% (66/174) B. magna. We determined that they were O. petrowi through morphological comparison of L3 from experimentally infected Acheta domesticus and by sequence analysis. Then, we showed that B. magna are a potential intermediate hosts for O. petrowi infections in northern bobwhites (Colinus virginianus) in a laboratory setting by experimental infection. We first detected shedding of eggs in feces using a fecal float technique 52 days post infection. In addition, we recovered 87 O. petrowi from experimentally infected northern bobwhites. Although we detected shedding in feces, recovery of eggs was low (>5 eggs/g). Future work is needed to understand shedding routes and shedding patterns of northern bobwhites infected with O. petrowi.
The subsurface exploration of other planetary bodies can be used to unravel their geological history and assess their habitability. On Mars in particular, present-day habitable conditions may be restricted to the subsurface. Using a deep subsurface mine, we carried out a program of extraterrestrial analog research – MINe Analog Research (MINAR). MINAR aims to carry out the scientific study of the deep subsurface and test instrumentation designed for planetary surface exploration by investigating deep subsurface geology, whilst establishing the potential this technology has to be transferred into the mining industry. An integrated multi-instrument suite was used to investigate samples of representative evaporite minerals from a subsurface Permian evaporite sequence, in particular to assess mineral and elemental variations which provide small-scale regions of enhanced habitability. The instruments used were the Panoramic Camera emulator, Close-Up Imager, Raman spectrometer, Small Planetary Linear Impulse Tool, Ultrasonic drill and handheld X-ray diffraction (XRD). We present science results from the analog research and show that these instruments can be used to investigate in situ the geological context and mineralogical variations of a deep subsurface environment, and thus habitability, from millimetre to metre scales. We also show that these instruments are complementary. For example, the identification of primary evaporite minerals such as NaCl and KCl, which are difficult to detect by portable Raman spectrometers, can be accomplished with XRD. By contrast, Raman is highly effective at locating and detecting mineral inclusions in primary evaporite minerals. MINAR demonstrates the effective use of a deep subsurface environment for planetary instrument development, understanding the habitability of extreme deep subsurface environments on Earth and other planetary bodies, and advancing the use of space technology in economic mining.
Anxiety and depression are common following traumatic brain injury (TBI), often co-occurring. This study evaluated the efficacy of a 9-week cognitive behavioral therapy (CBT) program in reducing anxiety and depression and whether a three-session motivational interviewing (MI) preparatory intervention increased treatment response.
A randomized parallel three-group design was employed. Following diagnosis of anxiety and/or depression using the Structured Clinical Interview for DSM-IV, 75 participants with mild-severe TBI (mean age 42.2 years, mean post-traumatic amnesia 22 days) were randomly assigned to an Adapted CBT group: (1) MI + CBT (n = 26), or (2) non-directive counseling (NDC) + CBT (n = 26); or a (3) waitlist control (WC, n = 23) group. Groups did not differ in baseline demographics, injury severity, anxiety or depression. MI and CBT interventions were guided by manuals adapted for individuals with TBI. Three CBT booster sessions were provided at week 21 to intervention groups.
Using intention-to-treat analyses, random-effects regressions controlling for baseline scores revealed that Adapted CBT groups (MI + CBT and NDC + CBT) showed significantly greater reduction in anxiety on the Hospital Anxiety and Depression Scale [95% confidence interval (CI) −2.07 to −0.06] and depression on the Depression Anxiety and Stress Scale (95% CI −5.61 to −0.12) (primary outcomes), and greater gains in psychosocial functioning on Sydney Psychosocial Reintegration Scale (95% CI 0.04–3.69) (secondary outcome) over 30 weeks post-baseline relative to WC. The group receiving MI + CBT did not show greater gains than the group receiving NDC + CBT.
Findings suggest that modified CBT with booster sessions over extended periods may alleviate anxiety and depression following TBI.
Botulism has rarely been reported in Africa. In October 2008, botulism was reported in three Ugandan boarding-school students. All were hospitalized and one died. A cohort study was performed to assess food exposures among students, and clinical specimens and available food samples were tested for botulinum toxin. Three case-patients were identified; a homemade, oil-based condiment was eaten by all three. In the cohort study, no foods were significantly associated with illness. Botulinum toxin type A was confirmed in clinical samples. This is the first confirmed outbreak of foodborne botulism in Uganda. A homemade, oil-based condiment was the probable source. Consumption of homemade oil-based condiments is widespread in Ugandan schools, putting children at risk. Clinicians and public health authorities in Uganda should consider botulism when clusters of acute flaccid paralysis are seen. Additionally, schools should be warned of the hazard of homemade oil-based condiments, and take steps to prevent their use.
We investigated offspring quality in fleas (Xenopsylla ramesis) feeding on non-reproducing, pregnant or lactating rodents (Meriones crassus) and asked whether (a) quality of flea offspring differs dependent on host reproductive status; (b) fleas trade off offspring quantity for quality; and (c) quality variables are inter-correlated. Emergence success was highest when parents exploited pregnant hosts, while development time was longest when parents exploited lactating hosts. Male offspring from fleas fed on non-reproductive and pregnant hosts were larger than those from lactating hosts whereas female offspring from fleas fed on pregnant hosts were larger than those from both lactating and non-reproductive hosts. Male offspring survived under starvation the longest when their parents exploited lactating hosts and the shortest when their parents exploited pregnant hosts. Female offspring of parents that exploited lactating hosts survived under starvation longer than those that exploited non-reproductive and pregnant hosts. Emergence success and development time decreased as mean number of eggs laid by mothers increased. Fleas that were larger and took longer to develop lived significantly longer under starvation. These results indicate the presence of a trade-off between offspring quantity and quality in fleas exploiting female Sundevall's jird in varying reproductive condition but this trade-off depended on the quality trait considered.