23 research outputs found

    137CS gamma-ray detection at Summit, Greenland

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    Global fall-out from atmospheric testing of thermonuclear weapons produced horizon markers corresponding to the initiation of testing in 1953 and the maximum fall-out in 1963. The radioactive isotope 137Cs associated with these events has a half-life of 30.2 years. Therefore, with the appropriate radiation detectors, this fall-out can be used as a long-term temporal indicator in glaciers and snowpack. A prototype γ-ray detector system was successfully tested and was used to make in-situ measurements of the 137Cs marker in a borehole at Summit, Greenland. The system consisted of a 7.6 cm by 7.6 cm NaI (Tl) scintillation crystal/photomultiplier detector, commercial pre-amplifier, amplifier and power supplies, and a microcomputer-based pulse-height analyzer. The measurements were made in boreholes of 25.4 cm and 12.7 cm diameter to depths of 22 m. Based on the results reported here, the γ-ray detection technique promises to be a powerful way to locate quickly horizon markers in the field. -Author

    New quick method for isolating RNA from laser captured cells stained by immunofluorescent immunohistochemistry; RNA suitable for direct use in fluorogenic TaqMan one-step real-time RT-PCR

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    We describe a new approach for reliably isolating one-step real-time quantitative RT-PCR-quality RNA from laser captured cells retrieved from frozen sections previously subjected to immunofluorescent immunohistochemistry (IF-IHC) and subsequently subjected to fluorogenic one-step real-time RT-PCR analysis without the need for costly, time-consuming linear amplification. One cell’s worth of RNA can now be interrogated with confidence. This approach represents an amalgam of technologies already offered commercially by Applied Biosystems, Arcturus and Invitrogen. It is the primary focus of this communication to expose the details and execution of an important new LCM RNA isolation technique, but also provide a detailed account of the IF-IHC procedure preceding RNA isolation, and provide information regarding our approach to fluorogenic one-step real-time RT-PCR in general. Experimental results shown here are meant to supplement the primary aim and are not intended to represent a complete scientific study. It is important to mention, that since LCM-RT-PCR is still far less expensive than micro-array analysis, we feel this approach to isolating RNA from LCM samples will be of continuing use to many researchers with limited budgets in the years ahead

    Novel Indirect Calorimetry Technology to Analyze Metabolism in Individual Neonatal Rodent Pups

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    BACKGROUND: The ability to characterize the development of metabolic function in neonatal rodents has been limited due to technological constraints. Low respiratory volumes and flows at rest pose unique problems, making it difficult to reliably measure O(2) consumption, CO(2) production, respiratory quotient (RQ), and energy expenditure (EE). Our aim was to develop and validate a commercial-grade indirect calorimetry system capable of characterizing the metabolic phenotype of individual neonatal rodents. METHODOLOGY/PRINCIPAL FINDINGS: To address this research need, we developed a novel, highly sensitive open-circuit indirect calorimetry system capable of analyzing respiratory gas exchange in a single neonatal rodent pup. Additionally, we derived an equation from known metabolic relationships to estimate inlet flow rates, improving the efficiency of data collection. To validate the neonatal rodent indirect calorimetry system and evaluate the applicability of the derived equation for predicting appropriate flow rates, we conducted a series of experiments evaluating the impact of sex, litter size, time of day (during the light phase), and ambient temperature on neonatal rat metabolic parameters. Data revealed that the only metabolic parameter influenced by litter size is a neonatal rat's RQ, with rat pups reared in a small litter (5 pups) having lower RQ's than rat pups reared in either medium (8 pups) or large (11 pups) litters. Furthermore, data showed that ambient temperature affected all metabolic parameters measured, with colder temperatures being associated with higher CO(2) production, higher O(2) consumption, and higher energy expenditure. CONCLUSION/SIGNIFICANCE: The results of this study demonstrate that the modified Panlab Oxylet system reliably assesses early postnatal metabolism in individual neonatal rodents. This system will be of paramount importance to further our understanding of processes associated with the developmental origins of adult metabolic disease

    BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

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    Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

    Creating and curating an archive: Bury St Edmunds and its Anglo-Saxon past

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    This contribution explores the mechanisms by which the Benedictine foundation of Bury St Edmunds sought to legitimise and preserve their spurious pre-Conquest privileges and holdings throughout the Middle Ages. The archive is extraordinary in terms of the large number of surviving registers and cartularies which contain copies of Anglo-Saxon charters, many of which are wholly or partly in Old English. The essay charts the changing use to which these ancient documents were put in response to threats to the foundation's continued enjoyment of its liberties. The focus throughout the essay is to demonstrate how pragmatic considerations at every stage affects the development of the archive and the ways in which these linguistically challenging texts were presented, re-presented, and represented during the Abbey’s history

    A gamma-ray detector for in-situ measurement of 137Cs radioactivity in snowfields and glaciers

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    he rate of snow deposition at various cold regions on the earth is an important quantity for glaciological and climatological studies. Radioactive debris from above-ground tests of nuclear weapons (mainly 1954–1970) and from the Chernobyl accident (1986) have been deposited on glaciers and snowfields, where they can be used as time and depth markers to determine the subsequent accumulation of snow. We discuss a technique to locate these markers that has been used just recently — in-situ measurement of γ-rays from 137Cs. These γ-rays, which are associated with radioactive fallout, have a distinctive depth profile and serve as markers of the historical nuclear events. The γ-ray measurement involves lowering a scintillation detector down a borehole in the snow or ice and recording the response to the 137Cs γ-rays as a function of depth. The in-situ measurement can be done relatively quickly and can replace sample retrieval, or it can be used to decide which ice or snow samples should be transported for later analysis in the laboratory. The feasibility of in-situ γ-ray measurement has been demonstrated at sites in the French Alps and Greenland. We report on a portable detector system that is being developed for use in Antarctica. It is based, as much as possible, on inexpensive, commercially available detectors and electronics. The advantages and disadvantages of this approach are discussed. The problems involved with making these measurements in a harsh environment and the steps taken to deal with them are also presented

    The effect of litter size on metabolic outcomes.

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    <p>Metabolic parameters from each rat subject in small (SML), medium (MED) and large (LRG) litters were surveyed on alternate days from P2–P14 at an ambient temperature of 28°C. All data are expressed as means±SEM. No differences between groups were noted for (A) carbon dioxide production (<i>VCO<sub>2</sub></i>), (B) oxygen consumption (<i>VO<sub>2</sub></i>), or (D) daily energy expenditure (<i>EE</i>). Differences between groups were observed for (C) respiratory quotient (<i>RQ</i>), with rats from the SML litter having lower <i>RQ's</i> than rats from the other litters. Days in which significant differences existed between groups are noted by asterisks.</p

    Oxylet Neonatal Indirect Calorimetry System.

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    <p>To collect metabolic data, the Panlab Oxylet neonatal rodent indirect calorimetry system prototype was used in conjunction with associated apparati. The following components are identified: (A) LE 405 gas analyzer, (B) LE 400 Air Supply and Switching unit, (C) 215 ml metabolic chamber with bedding material, (D) 10-gallon aquarium, (E) Plexiglas sheet over water-filled Pyrex pan, and (F) variable-control heating pad.</p

    The effect of ambient temperature on metabolic outcomes.

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    <p>Metabolic parameters from each rat subject tested at ambient temperatures of 25°C, 30°C, and 34°C were surveyed on alternate days from P2–P6. All data are expressed as means±SEM. Differences between groups were observed for (A) carbon dioxide production (<i>VCO<sub>2</sub></i>), (B) oxygen consumption (<i>VO<sub>2</sub></i>), (C) respiratory quotient (<i>RQ</i>), and (D) daily energy expenditure (<i>EE</i>). Rats tested at 25°C demonstrated the highest <i>VCO<sub>2</sub></i>, <i>VO<sub>2</sub></i>, and <i>EE</i> values, while rats tested at 34°C demonstrated the lowest values in the same parameters. Days in which significant differences existed between groups are noted by asterisks.</p

    The effect of litter size on growth outcomes.

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    <p>Growth measures were collected for each rat subject used from small (SML), medium (MED) and large (LRG) litters at an ambient temperature of 28°C. All data are presented as means±SEM. Analysis of (A) body weight, (B) snout-to-rump (<i>SR</i>) length, and (C) snout-to-occiput (<i>SO</i>) length data revealed that rats from the SML litter showed the greatest increases in growth from P2–P14. Days in which significant differences existed between groups are noted by asterisks.</p
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