686 research outputs found
A need for dynamic hematology and serum biochemistry reference tools: Novel use of sine wave functions to produce seasonally varying reference curves in platypuses (Ornithorhynchus anatinus)
Seasonal changes in hematology and serum biochemistry results, described by separate reference intervals for different seasons, have been reported in many animals. We developed a novel method to investigate seasonal variation in values and a reference tool (the reference curve) based on sine wave functions that, for suitable variables, represents data more appropriately than a fixed reference interval. We applied these techniques to values observed in blood samples from 126 adult wild platypuses (Ornithorhynchus anatinus; 58 females and 68 males). Samples were collected under isoflurane anesthesia from animals captured in the Inglis Catchment in northwest Tasmania. In general, packed cell volume (PCV), red cell count (RCC), and hemoglobin (Hb) values appeared to be lower than those in two studies that previously reported platypus hematology reference intervals. This likely resulted from reduced stress-related splenic contraction or isoflurane-associated splenic sequestration of red blood cells in our study. Reference curves were described for five variables (PCV, RCC, Hb, albumin, and magnesium). We found evidence that this seasonal variation may result from metabolic changes associated with seasonal variations in environmental temperature. These observations suggest that it is important for researchers reporting platypus hematology and serum biochemistry to look for seasonal changes in their data to ensure it is appropriately interpreted
Investigation into the characteristics, triggers and mechanism of apnoea and bradycardia in the anaesthetized platypus (Ornithorhynchus anatinus)
Health and conservation research on platypuses (Ornithorhynchus anatinus) may require anaesthesia to reduce stress and the risk of injury to both the animal and the researcher, as well as to facilitate examination and sample collection. Platypus anaesthesia can be difficult to manage, with reports of periods of apnoea and bradycardia described. This study investigated the conditions around sudden-onset apnoea and bradycardia in 163 field-anaesthetized platypuses as part of a health study. Anaesthesia was induced and maintained using isoflurane delivered in oxygen by face mask. Sudden-onset apnoea and bradycardia was observed in 19% of platypuses, occurring either at induction of anaesthesia, during recovery, or both. At induction, occurrence was more often recorded for adults (P = 0.19) and was correlated with low body temperature (P < 0.001), season (P = 0.06; greater incidence in summer) and longer pre-anaesthetic holding time (P = 0.16). At recovery, sudden-onset apnoea and bradycardia occurred only in platypuses that had been placed in dorsal recumbency as part of their examination, and correlated with poor body condition (P = 0.002), time in dorsal recumbency (P = 0.005), adults (P = 0.06), number of fieldworkers (P = 0.06) and females (P = 0.11). The sudden-onset apnoea and bradycardia we observed is likely to result from the irritant nature of isoflurane (stimulating the trigeminal nerve via nasal chemoreceptors). We propose that this mechanism is analogous to that of submersion of the face/nasal cavity in cold water during a natural dive response, but that the term ‘nasopharyngeal response’ would more appropriately describe the changes observed under isoflurane anaesthesia. Although we did not record any long-term adverse effects on platypuses that had undergone this response, the nasopharyngeal response could complicate the diagnosis of anaesthetic dose-dependent apnoea and bradycardia. Therefore, we suggest that these responses during anaesthesia of platypuses might be avoided by minimizing the stress around capture and handling, as well as reducing the time in dorsal recumbency
Novel use of in-stream microchip readers to monitor wild platypuses
A variety of techniques have been used to monitor platypus populations to assess the impacts of the threats they face, but each technique has limitations. In this study we investigated the novel use of in-stream microchip readers, to remotely monitor the movements of microchipped wild platypuses. Over 13 months, we recorded movements of 18 microchipped individuals past nine fixed locations in the Inglis Catchment in northwest Tasmania, using three units of which all were capable of detecting Trovan® unique microchips and two were additionally capable of detecting ISO microchips. Each site was monitored one or two times, for durations of 8–39 days. We undertook direction of movement investigations during two monitoring periods, by placing the antennas from two systems in the same creek within 3 m of each other. In a total of 264 days of monitoring, 528 platypus observations were made from 18 individual platypuses, consisting of 13 of 18 (72%) platypuses captured at the monitoring sites within 16 months prior to monitoring, two platypuses captured at other sites in the same time period, and three of seven (43%) individuals microchipped 3–5 years previously. This number of platypus observations, in combination with the stable number of platypuses observed per day, the range of movement behaviours recorded and the results of the direction of movement investigations, indicates that at appropriate sites, in-stream microchip readers are an effective method of monitoring the movements and survivorship of microchipped wild platypuses
Investigation into individual health and exposure to infectious agents of platypuses (Ornithorhynchus anatinus) in two river catchments in northwest Tasmania
Changes in the health of individuals within wildlife populations can be a cause or effect of population declines in wildlife species. Aspects of individual platypus (Ornithorhynchus anatinus) health have been reported. However, holistic studies investigating potential synergistic effects of both pathogens and environmental factors are needed to expand understanding of platypus individual health. We collected baseline data on the health of platypuses in two Tasmanian river catchments (including evidence of the potentially fatal fungal disease mucormycosis) and on individual, demographic, and geographic patterns associated with health data results. We examined 130 wild platypuses from the Inglis River Catchment and 24 platypuses from the Seabrook Creek Catchment in northwest Tasmania between 29 August 2011 and 31 August 2013. More than 90% of captured platypuses were infected with ticks, Theileria spp., and trypanosomes. Evidence of exposure to other infections, including Salmonella spp., Leptospira spp., and intestinal parasites, was low (<10%). Three platypuses had single fungal granulomas in the webbing of a forefoot, but no evidence of mucormycosis was found in any of the study animals. Possible subclinical hepatopathies or cholangiohepatopathies were found in six platypuses. Exposure to infectious agents did not cluster geographically, demographically, or in individuals, and there was minimal evidence of morbidity resulting from infection. This study has provided important baseline data for monitoring the effects of threatening processes, including mucormycosis, on the health of infected populations
Nursing education and beliefs towards tobacco cessation and control: a cross- sectional national survey (GHPSS) among nursing students in Greece
<p>Abstract</p> <p>Background</p> <p>Within the healthcare system, nurses have the ability to influence their patients' smoking habits through counselling. Therefore, it is of great importance to appropriately train health professionals on smoking cessation strategies with the aim to help them provide advice to their patients. In light of the above, the objective of this study was to assess the association between Greek nursing students' beliefs towards tobacco control/smoking cessation and the professional training received.</p> <p>Methods</p> <p>During February 2009, we conducted a cross sectional national survey among all 3<sup>rd </sup>year nursing students of the two university based nursing departments in Greece (University of Athens, University of the Peloponnese). The Global Health Professional Student Survey (GHPSS) questionnaire was applied and following written informed consent 73% provided a completed questionnaire (n = 192/263 enrolled students).</p> <p>Results</p> <p>Overall, 33% were current active smokers, while 74% reported ever to experiment smoking. In regards to their beliefs towards tobacco control policies, non smokers were more positive in regards to banning smoking in restaurants (94% vs. 61%, p < 0.001), in bars and cafes (82% vs. 34%, p < 0.001), and all public places (93% vs. 51%, p < 0.001) when compared to current smokers. In comparison with students who had not received training on the importance of asking patients about their smoking habits, those that did were more likely to believe that nurses should have a role in smoking cessation and should act as role models for their patients.</p> <p>Conclusions</p> <p>Resources should be invested in improving the quality of undergraduate education in nursing departments in Greece with respect to tobacco control and smoking cessation.</p
Recycling Argon through Metamorphic Reactions: the Record in Symplectites
The 40Ar/39Ar ages of metamorphic micas that crystallized at high temperatures are commonly interpreted as cooling ages, with grains considered to have lost 40Ar via thermally-driven diffusion into the grain boundary network. Recently reported laser-ablation data suggest that the spatial distribution of Ar in metamorphic micas does not always conform to the patterns predicted by diffusion theory and that despite high metamorphic temperatures, argon was not removed efficiently from the local system during metamorphic evolution. In the Western Gneiss Region (WGR), Norway, felsic gneisses preserve microtextural evidence for the breakdown of phengite to biotite and plagioclase symplectites during near isothermal decompression from c. 20–25 to c. 8–12 kbar at ~700°C. These samples provide an ideal natural laboratory to assess whether the complete replacement of one K-bearing mineral by another at high temperatures completely ‘resets’ the Ar clock, or whether there is some inheritance of 40Ar in the neo-crystallized phase. The timing of the high-temperature portion of the WGR metamorphic cycle has been well constrained in previous studies. However, the timing of cooling following the overprint is still much debated. In-situ laser ablation spot dating in phengite, biotite-plagioclase symplectites and coarser, texturally later biotite yielded 40Ar/39Ar ages that span much of the metamorphic cycle. Together these data show that despite residence at temperatures of ~700°C, Ar is not completely removed by diffusive loss or during metamorphic recrystallization. Instead, Ar released during phengite breakdown appears to be partially reincorporated into the newly crystallizing biotite and plagioclase (or is trapped in fluid inclusions in those phases) within a close system. Our data show that the microtextural and petrographic evolution of the sample being dated provides a critical framework in which local 40Ar recycling can be tracked, thus potentially allowing 40Ar/39Ar dates to be linked more accurately to metamorphic history
Spectroscopic detection of quasars in the 2dF Galaxy Redshift Survey
The 100,000 spectra from the 2 degree Field Galaxy Redshift Survey (2dFGRS)
in the 100k Public Data Release represent the largest single compilation of
galaxy spectra available. By virtue of its sheer size and the properties of the
photometric catalogue that defines the sample, the 2dFGRS is expected to
contain a number of potentially interesting objects other than galaxies. A
search of the spectra in the 100k Data Release results in a census of 55
candidate high-redshift (z > 0.3) quasars. One additional 2dFGRS spectrum of a
low-redshift galaxy shows an apparent anomalous broad emission feature perhaps
indicating the presence of a gravitationally lensed quasar. These objects have
been identified primarily using two automated routines that we have developed
specifically for this task, one of which uses a matched filter and the other a
wavelet transform. A number of the quasar images possess complicated
morphologies, suggesting the presence of either diffuse foreground objects
along the line-of-sight or very nearby point sources. The quasar catalogue will
form a target list for future absorption and lensing studies, as well as
providing an assessment of the loss of quasars with non-stellar images from the
companion 2dF QSO Redshift Survey.Comment: Latex 13 pages, 8 figures. Accepted for publication in MNRA
Deep Submillimeter Surveys: Luminous Infrared Galaxies at High Redshift
Deep surveys at 850microns from Mauna Kea using the SCUBA camera on the JCMT
appear to have discovered a substantial population of ultraluminous infrared
galaxies (ULIGs: L_ir > 10^{12} L_sun). The cumulative space density of these
sources (~10,000 per sq.deg with S_850 > 1mJy) is sufficient to account for
nearly all of the extragalactic background light at submillimeter wavelengths.
Current estimates of the redshift distribution suggest a peak in the comoving
space density of SCUBA sources at z = 1-3, similar to what is observed for QSOs
and radio galaxies. The luminosity density in the far-infrared/submillimeter
exceeds that in the UV by factors of 3-10 over this redshift range, implying
that as much as 80-90% of the "activity" in galaxies at z < 4 is hidden by
dust. The SCUBA sources plausibly represent the primary epoch in the formation
of spheroids and massive black holes triggered by major mergers of large
gas-rich disks.Comment: LaTex, 14 pages with 9 embedded .eps figures. To appear in ``Space
Infrared Telescopes and Related Science", 32nd COSPAR workshop, Nagoya, Japan
1998, ed. T. Matsumoto, T. de Graau
Exact and near backscattering measurements of the linear depolarisation ratio of various ice crystal habits generated in a laboratory cloud chamber
© 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license(http://creativecommons.org/licenses/by/4.0/).Ice clouds were generated in the Manchester Ice Cloud Chamber (MICC), and the backscattering linear depolarisation ratio, δ, was measured for a variety of habits. To create an assortment of particle morphologies, the humidity in the chamber was varied throughout each experiment, resulting in a range of habits from the pristine to the complex. This technique was repeated at three temperatures: −7 °C, −15 °C and −30 °C, in order to produce both solid and hollow columns, plates, sectored plates and dendrites. A linearly polarised 532 nm continuous wave diode laser was directed through a section of the cloud using a non-polarising 50:50 beam splitter. Measurements of the scattered light were taken at 178°, 179° and 180°, using a Glan–Taylor prism to separate the co- and cross-polarised components. The intensities of these components were measured using two amplified photodetectors and the ratio of the cross- to co-polarised intensities was measured to find the linear depolarisation ratio. In general, it was found that Ray Tracing over-predicts the linear depolarisation ratio. However, by creating more accurate particle models which better represent the internal structure of ice particles, discrepancies between measured and modelled results (based on Ray Tracing) were reduced.Peer reviewe
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