373 research outputs found

    Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

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    Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans

    The Influence of Moderate Hypercapnia on Neural Activity in the Anesthetized Nonhuman Primate

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    Hypercapnia is often used as vasodilatory challenge in clinical applications and basic research. In functional magnetic resonance imaging (fMRI), elevated CO2 is applied to derive stimulus-induced changes in the cerebral rate of oxygen consumption (CMRO2) by measuring cerebral blood flow and blood-oxygenation-level–dependent (BOLD) signal. Such methods, however, assume that hypercapnia has no direct effect on CMRO2. In this study, we used combined intracortical recordings and fMRI in the visual cortex of anesthetized macaque monkeys to show that spontaneous neuronal activity is in fact significantly reduced by moderate hypercapnia. As expected, measurement of cerebral blood volume using an exogenous contrast agent and of BOLD signal showed that both are increased during hypercapnia. In contrast to this, spontaneous fluctuations of local field potentials in the beta and gamma frequency range as well as multiunit activity are reduced by ∼15% during inhalation of 6% CO2 (pCO2 = 56 mmHg). A strong tendency toward a reduction of neuronal activity was also found at CO2 inhalation of 3% (pCO2 = 45 mmHg). This suggests that CMRO2 might be reduced during hypercapnia and caution must be exercised when hypercapnia is applied to calibrate the BOLD signal

    Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector

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    The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the MAJORANA Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure

    Effects of Tylosin Administration Routes on the Development of Antimicrobial Resistance in Fecal Enterococci of Finishing Swine

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    Antibiotics can be administered via various routes in pigs, which may influence antimicrobial resistance development. A total of 40 barrows and 40 gilts (Line 600 × 241; DNA, Columbus, NE; initially 207 ± 7.9 lb) were used in a 35-d trial to determine the effects of tylosin administration route on pig growth performance and development of antimicrobial resistance in fecal Enterococcus spp. isolates. Pens of pigs (1 pig/ pen, 20 pigs/treatment) were blocked by initial body weight (BW) and gender. Within blocks, pens were randomly allotted to 1 of 4 treatments. The antibiotic treatments followed US label directions and were: 1) no antibiotic (Control); 2) 110 mg tylosin per kg of feed for 21 d (Feed); 3) 8.82 mg tylosin per kg of BW through intramuscular injection twice daily for the first 3 d of each wk during the 3-wk treatment period (Injection); and 4) 66 mg of tylosin per liter of drinking water for the first 3 d of each wk during treatment period (Water). Treatments were offered during d 0 to 21, after which all pigs were fed a common diet with no antibiotic until d 35. Fecal samples were collected on d 0, 21, and 35. No evidence for route × gender interactions (P \u3e 0.55) were observed for any growth responses. From d 0 to 21, control pigs and pigs fed medicated feed had greater (P \u3c 0.05) average daily gain (ADG) than those that received injected tylosin, with the ADG of pigs receiving tylosin through the water intermediate. There was no evidence for different average daily feed intake (ADFI) among treatment groups. Pigs that received tylosin through injection or water had poorer (P \u3c 0.05) feed efficiency (F/G) compared with control pigs, but there was no evidence for difference from pigs receiving tylosin through feed. Among the medicated pigs, total tylosin dose administered was the greatest through injection, second highest through feed, with the water medication route the lowest. No evidence for route × day interactions (P \u3e 0.23) were observed for the development of bacterial resistance to any antibiotics. Enterococcal isolates collected from pigs receiving tylosin via feed or injection were more resistant (P \u3c 0.05) to erythromycin and tylosin compared with control pigs and those that received tylosin through water. The estimated probability of antimicrobial resistance to these 2 antibiotics was greater on d 21 and 35 than d 0. In summary, tylosin injection resulted in poorer ADG and F/G of finishing pigs, likely due to stress associated with handling and injection. Tylosin administration through injection and feed resulted in greater probability of enterococcal resistance to erythromycin and tylosin compared with in-water treatment, which is likely a combined effect of administration route and dosage

    The Co-Regulation of Emotions Between Mothers and their Children with Autism

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    Thirty-four toddlers with autism and their mothers participated in an early intervention targeting joint engagement. Across the 24 intervention sessions, any significant distress episode in the child was coded for emotion regulation outcomes including child negativity, child emotion self-regulation, and mother emotion co-regulation. Results revealed that emotion regulation strategies by both mother and child were employed during distress episodes. An effect of intervention was found such that children decreased their expression of negativity across the intervention and mothers increased their emotional and motivational scaffolding. The results of this study indicate a positive effect of an intervention targeting joint engagement on emotion co-regulation outcomes

    Small bowel MRI in adult patients: not just Crohn’s disease—a tutorial

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    To provide an overview of less well-known small bowel and mesenteric diseases found at small bowel magnetic resonance (MR) enterography/enteroclysis and to review the imaging findings. MR enterography and enteroclysis are important techniques for evaluation of small bowel diseases. In most centres these techniques are primarily used in Crohn's disease, and most radiologists are familiar with these MRI findings. However, the knowledge of findings in other diseases is often sparse, including diseases that may cause similar clinical symptoms to those of Crohn's disease. We present a spectrum of less common and less well-known bowel and mesenteric diseases (e.g. internal hernia, intussusception, neuroendocrine tumour) from our small bowel MR database of over 2,000 cases. These diseases can be found in patients referred for bowel obstruction, abdominal pain or rectal blood loss. Further, in patients with (or suspected to have) Crohn's disease, some of these diseases (e.g. neuroendocrine tumour, familial Mediterranean fever) may mislead radiologists to erroneously diagnose active Crohn's disease. Radiologists should be familiar with diseases affecting the small bowel other than Crohn's disease, including diseases that may mimic Crohn's diseas

    A Randomized Controlled Study of Parent-assisted Children’s Friendship Training with Children having Autism Spectrum Disorders

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    This study evaluated Children’s Friendship Training (CFT), a manualized parent-assisted intervention to improve social skills among second to fifth grade children with autism spectrum disorders. Comparison was made with a delayed treatment control group (DTC). Targeted skills included conversational skills, peer entry skills, developing friendship networks, good sportsmanship, good host behavior during play dates, and handling teasing. At post-testing, the CFT group was superior to the DTC group on parent measures of social skill and play date behavior, and child measures of popularity and loneliness, At 3-month follow-up, parent measures showed significant improvement from baseline. Post-hoc analysis indicated more than 87% of children receiving CFT showed reliable change on at least one measure at post-test and 66.7% after 3 months follow-up

    Mediators of the Link Between Autistic Traits and Relationship Satisfaction in a Non-Clinical Sample

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    People with ASD have deficits in their social skills and may therefore experience lower relationship satisfaction. This study investigated possible mechanisms to explain whether and how autistic traits, measured with the AQ, influence relationship satisfaction in a non-clinical sample of 195 married couples. More autistic traits were associated with lower relationship satisfaction for husbands but not for wives. Multiple mediation analyses revealed that husbands’ responsiveness towards their wives, trust, and intimacy mediated this link between autistic traits and relationship satisfaction. These findings suggest that autistic traits may hamper men’s relationship satisfaction because they impede relationship-specific feelings and behavior. There was no partner-effect of autistic traits, indicating that more autistic traits do not necessarily influence the partner’s perceptions of relationship satisfaction
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