Heterogeneities in the solar nebula

Oxygen isotopic compositions of the high-temperatue phases in carbonaceous chondrites define a mixing line with an O-16 rich component and show little superimposed chemical isotope fractionation. Within a single inclusion in Allende, variations of delta O-18 and delta O-17 of 39% are found. The ordinary chondrites are slightly displaced from the terrestrial fractionation trend, implying that at least 0.2% of the oxygen in terrestrial rocks was derived from the O-16 rich component

Electron Positron Annihilation Radiation from SgrA East at the Galactic Center

Maps of the Galactic electron-positron annihilation radiation show evidence for three distinct and significant features: (1) a central bulge source, (2) emission in the Galactic plane, and (3) an enhancement of emission at positive latitudes above the Galactic Center. In this paper, we explore the possibility that Sgr A East, a very prominent radio structure surrounding the Galactic nucleus, may be a significant contributer to the central bulge feature. The motivation for doing so stems from a recently proposed link between this radio object and the EGRET gamma-ray source 2EG J1746-2852. If this association is correct, then Sgr A East is also expected to be a source of copious positron production. The results presented here show that indeed Sgr A East must have produced a numerically significant population of positrons, but also that most of them have not yet had sufficient time to thermalize and annihilate. As such, Sgr A East by itself does not appear to be the dominant current source of annihilation radiation, but it will be when the positrons have cooled sufficiently and they have become thermalized. This raises the interesting possibility that the bulge component may be due to the relics of earlier explosive events like the one that produced Sgr A East.Comment: This manuscript was prepared with the AAS Latex macros v4.0 It is 37 pages long and has 16 figure

The Fabry disease-associated lipid Lyso-Gb3 enhances voltage-gated calcium currents in sensory neurons and causes pain

Fabry disease is an X-linked lysosomal storage disorder characterised by accumulation of glycosphingolipids, and accompanied by clinical manifestations, such as cardiac disorders, renal failure, pain and peripheral neuropathy. Globotriaosylsphingosine (lyso-Gb3), a deacylated form of globotriaosylceramide (Gb3), has emerged as a marker of Fabry disease. We investigated the link between Gb3, lyso-Gb3 and pain. Plantar administration of lyso-Gb3 or Gb3 caused mechanical allodynia in healthy mice. In vitro application of 100nM lyso-Gb3 caused uptake of extracellular calcium in 10% of sensory neurons expressing nociceptor markers, rising to 40% of neurons at 1μM, a concentration that may occur in Fabry disease patients. Peak current densities of voltage-dependent Ca(2+) channels were substantially enhanced by application of 1μM lyso-Gb3. These studies suggest a direct role for lyso-Gb3 in the sensitisation of peripheral nociceptive neurons that may provide an opportunity for therapeutic intervention in the treatment of Fabry disease-associated pain

Record of a Sixteen-year-old White-tailed Deer (Odocoileus virginianus) in Carbondale, Illinois: a Brief Note.

In May 2004, a dead white-tailed deer (Odocoileus virginianus) radiocollared in 1991 was found in Carbondale, Illinois, and was aged at 16 years old via cementum annuli analysis. She was a member of an unharvested, free-ranging population and likely died of natural causes. Given the average longevity of deer in unharvested populations at about 8 years of age, our finding is quite rare. Increased longevity of deer can heighten lifetime reproductive output, which may contribute to elevated deer abundance and concentrated herbivory in urban settings

Associative spike timing-dependent potentiation of the basal dendritic excitatory synapses in the hippocampus in vivo.

Spike timing-dependent plasticity in the hippocampus has rarely been studied in vivo. Using extracellular potential and current source density analysis in urethane-anesthetized adult rats, we studied synaptic plasticity at the basal dendritic excitatory synapse in CA1 after excitation-spike (ES) pairing; E was a weak basal dendritic excitation evoked by stratum oriens stimulation, and S was a population spike evoked by stratum radiatum apical dendritic excitation. We hypothesize that positive ES pairing-generating synaptic excitation before a spike-results in long-term potentiation (LTP) while negative ES pairing results in long-term depression (LTD). Pairing (50 pairs at 5 Hz) at ES intervals of -10 to 0 ms resulted in significant input-specific LTP of the basal dendritic excitatory sink, lasting 60-120 min. Pairing at +10- to +20-ms ES intervals, or unpaired 5-Hz stimulation, did not induce significant basal dendritic or apical dendritic LTP or LTD. No basal dendritic LTD was found after stimulation of stratum oriens with 200 pairs of high-intensity pulses at 25-ms interval. Pairing-induced LTP was abolished by pretreatment with an N-methyl-d-aspartate receptor antagonist, 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), which also reduced spike bursting during 5-Hz pairing. Pairing at 0.5 Hz did not induce spike bursts or basal dendritic LTP. In conclusion, ES pairing at 5 Hz resulted in input-specific basal dendritic LTP at ES intervals of -10 ms to 0 ms but no LTD at ES intervals of -20 to +20 ms. Associative LTP likely occurred because of theta-rhythmic coincidence of subthreshold excitation with a backpropagated spike burst, which are conditions that can occur naturally in the hippocampus

Seed Dispersal of an Invasive Shrub, Amur Honeysuckle (Lonicera maackii ), by White-tailed Deer in a Fragmented Agricultural-forest Matrix

Ungulates are potentially important seed dispersers for many invasive plant species. While our understanding of which invasive plant species are dispersed by ungulates has improved over the last decade, the factors influencing this process remain poorly understood. To address this, we explored whitetailed deer (Odocoileus virginianus) seed consumption and dispersal of an invasive shrub (Lonicera maackii) in fragmented agricultural-forest matrices in western Ohio. In a pairwise browse preference experiment, deer browsed at similar levels on branches of L. maackii with fruits removed and fruits intact (mean ± 95 % CI 57 ± 14 and 62 ± 14 %, respectively). We found no evidence that white-tailed deer disperse L. maackii seeds along an invasion front, but 31 % of deer pellet groups collected in an invaded area contained germinable L. maackii seeds (maximum number of germinable seeds = 30). By combining hourly movement data specific to fragmented landscapes and gut retention time data, we projected that female deer disperse 91 %of ingested seeds further than 100 m from seed sources (i.e., long-distance seed dispersal), and rarely disperse seeds up to 7.9 km. We conclude that white-tailed deer can be important long-distance seed dispersal vectors of L. maackii, and that invader abundance and/or patch connectivity likely influence patterns of seed dispersal by white-tailed deer

Variable-Speed-of-Light Cosmology and Second Law of Thermodynamics

We examine whether the cosmologies with varying speed of light (VSL) are compatible with the second law of thermodynamics. We find that the VSL cosmology with varying fundamental constant is severely constrained by the second law of thermodynamics, whereas the bimetric cosmological models are less constrained.Comment: 15 pages, LaTeX, Revised version with minor corrections to appear in Phys. Rev.

Economic Impact of Beef Cattle Best Management Practices in South Texas: Stocking Strategies during Drought

In a drought situation, forage is normally reduced due to lack of adequate moisture. Moreover, the availability of hay may become limited, and hay prices often escalate. Cow-calf producers are faced with the integral decision to maintain their herds and supplemental feed or reduce the herd to minimize feeding requirements and costs. The management decision to maintain versus destock can significantly impact producer profits and financial position. This paper illustrates the financial implications of alternative management stocking strategies in a drought situation optimizing profitability of ranching operations

A Reanalysis of theUltraviolet Extinction from Interstellar Dust in the Large Magellanic Cloud

We have reanalyzed the Large Magellanic Cloud's (LMC) ultraviolet (UV) extinction using data from the IUE final archive. Our new analysis takes advantage of the improved signal--to--noise of the IUE NEWSIPS reduction, the exclusion of stars with very low reddening, the careful selection of well matched comparison stars, and an analysis of the effects of Galactic foreground dust. Differences between the average extinction curves of the 30 Dor region and the rest of the LMC are reduced compared to previous studies. We find that there is a group of stars with very weak 2175 Ang. bumps that lie in or near the region occupied by the supergiant shell, LMC 2, on the southeast side of 30 Dor. The average extinction curves inside and outside LMC 2 show a very significant difference in 2175 Ang. bump strength, but their far--UV extinctions are similar. While it is unclear whether or not the extinction outside the LMC 2 region can be fit with the relation of Cardelli, Clayton and Mathis (CCM), sightlines near LMC 2 cannot be fit with CCM due to their weak 2175 Ang. bumps. While the extinction properties seen in the LMC lie within the range of properties seen in the Galaxy, the correlations of UV extinction properties with environment seen in the Galaxy do not appear to hold in the LMC.Comment: 29 pages, 10 figures, to be published in Ap

Online tool for monitoring adverse events in patients with cancer during treatment (eRAPID): field testing in a clinical setting

Objectives: Electronic patient self-Reporting of Adverse-events: Patient Information and aDvice (eRAPID) is an online system developed to support patient care during cancer treatment by improving the detection and management of treatment-related symptoms. Patients can complete symptom reports from home and receive severity-based self-management advice, including notifications to contact the hospital for severe symptoms. Patient data are available in electronic records for staff to review. Prior to the commencement of a randomised controlled trial (RCT), field testing of the intervention was undertaken to troubleshoot practical issues with intervention integration in clinical practice. Design: Observational clinical field testing. Setting: Medical oncology breast service in a UK cancer centre. Participants: 12 patients receiving chemotherapy for early breast cancer and 10 health professionals (oncologists and specialist nurses). Intervention: Patients were asked to use the eRAPID intervention and complete weekly online symptom reports during four cycles of chemotherapy. Clinical staff were invited to access and use patient data in clinical assessments. Analysis: Descriptive data on the frequency of online symptom report completion and severe symptom notifications were collated. Verbal and written feedback was collected from patients and staff and semistructured interviews were conducted to explore patient experiences. Interviews were transcribed and analysed thematically. Results: The testing ran from January 2014 to March 2014. Feedback from patients and staff was largely positive. Patients described eRAPID as ‘reassuring’ and ‘comforting’ and valued the tailored management advice. Several changes were made to refine eRAPID. In particular, improvement of the clinical notification, patient reminder systems and changes to patient and staff training. Conclusions: The field testing generated valuable results used to guide refinement of eRAPID prior to formal intervention evaluation. Feedback indicated that eRAPID has the potential to improve patients’ self-efficacy, knowledge and confidence with managing symptoms during treatment. A large-scale RCT is underway with data collection due to finish in October 2018