20 research outputs found

    Distinguishing personal belief from scientific knowledge for the betterment of killer whale welfare \u2013 a commentary

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    We contest publication of Marino et al. regarding captive killer whale (Orcinus orca) welfare because of misrepresentations of available data and the use of citations that do not support assertions. Marino et al. misrepresent stress response concepts and erroneously cite studies, which appear to support Marino et al.\u2019s philosophical beliefs regarding the cetacean hypothalamic\u2013pituitary\u2013adrenal axis. To be clear, these misrepresentations are not differences of scientific opinion, as the authors\u2019 conclusions lack any scientific basis. More extensive review of Marino et al.\u2019s citations reveal a dearth of empirical evidence to support their assertions. Further, Marino et al.\u2019s approach to animal welfare is not consistent with conventional veterinary approaches to animal welfare, including their apparent opposition to use of preventative and therapeutic veterinary interventions. While Marino et al. argue that killer whales\u2019 cognitive and spatial needs preclude management of this species under human care, misrepresentation of the citations used to support this opinion invalidates their arguments. Misleading interpretations of data relative to killer whales\u2019 cognitive and emotional needs and specious and unsubstantiated comparisons with states experienced by humans with posttraumatic stress disorder and other conditions, represent a number of strategies used to misrepresent knowledge regarding killer whale welfare. These misrepresentations and fallacies are inconsistent with scientific ethical standards for credible, peer-reviewed journals (ICMJE, 2018), and are barriers to rigorous discourse and identification of strategies for optimizing killer whale welfare. Assertions in the paper amount to nothing more than a compilation of conclusory, philosophical statements. We would also like to mention that manuscripts such as Marino et al.\u2019s do great damage to the fields of comparative psychology and to behavioral science as a whole

    Star formation losses due to tidal debris in `hierarchical' galaxy formation

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    Bottom-up hierarchical formation of dark matter haloes is not as monotonic as implicitly assumed in the Press-Schechter formalism: matter can be ejected into tidal tails, shells or low density `atmospheres'. The implications that the possible truncation of star formation in these tidal `debris' may have for observational galaxy statistics are examined here using the ArFus N-body plus semi-analytical galaxy modelling software. Upper and lower bounds on stellar losses implied by a given set of N-body simulation output data can be investigated by choice of the merging/identity criterion of haloes between successive N-body simulation output times. A median merging/identity criterion is defined and used to deduce an upper estimate of possible star formation and stellar population losses. A largest successor merging/identity criterion is defined to deduce an estimate which minimises stellar losses. In the N-body simulations studied, the debris losses are short range in length and temporary; maximum loss is around 16%. The induced losses for star formation and luminosity functions are strongest (losses of 10%-30%) for low luminosity galaxies and at intermediate redshifts (1 < z < 3). This upper bound on likely losses is smaller than present observational uncertainties. Hence, Press-Schechter based galaxy formation models are approximately valid despite ignoring loss of debris, provided that dwarf galaxy statistics are not under study.Comment: 17 pages, 14 figures, accepted for Astronomy & Astrophysic

    Controls on subaerial erosion rates in Antarctica

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    Erosion rates offer insight on landscape development and the relative importance of chemical and physical processes of weathering. Minimal chemical weathering makes Antarctica an ideal location in which to compare the physical weathering of carbonate rocks to other lithologies. Here we report the first cosmogenic nuclide-derived erosion rates for carbonate rocks in Antarctica. Carbonate samples collected in the southernmost Ellsworth Mountains reflect a 36Cl erosion rate of 0.22 ± 0.02 mm/ka. This erosion rate is consistent with other reported Antarctic erosion rates, but is lower than 36Cl erosion rates derived from other arid regions in the world. These results are integrated with a continent-wide reanalysis of 28 erosion rate studies (>200 measurements), which comprise numerous rock types and other cosmogenic nuclides. By combining cosmogenic nuclide-derived erosion rates across studies, the larger trends provide insight into factors (e.g. lithology, glacial history, and availability of abrasive material) affecting subaerial erosion rates in Antarctica. Statistical analysis of the compiled data set shows differences based on lithology, with sandstone having the largest range of erosion rates. The compiled data also reveals higher erosion rates in areas with a large potential sediment supply, like the Dry Valleys. Samples collected from boulders yield lower erosion rates than those collected from bedrock, likely due to a combination of physical processes that affect boulders and bedrock differently, and glacial history, which can affect the apparent cosmogenic-nuclide derived erosion rate

    Observations of the High Redshift Universe

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    (Abridged) In these lectures aimed for non-specialists, I review progress in understanding how galaxies form and evolve. Both the star formation history and assembly of stellar mass can be empirically traced from redshifts z~6 to the present, but how the various distant populations inter-relate and how stellar assembly is regulated by feedback and environmental processes remains unclear. I also discuss how these studies are being extended to locate and characterize the earlier sources beyond z~6. Did early star-forming galaxies contribute significantly to the reionization process and over what period did this occur? Neither theory nor observations are well-developed in this frontier topic but the first results presented here provide important guidance on how we will use more powerful future facilities.Comment: To appear in `First Light in Universe', Saas-Fee Advanced Course 36, Swiss Soc. Astrophys. Astron. in press. 115 pages, 64 figures (see http://www.astro.caltech.edu/~rse/saas-fee.pdf for hi-res figs.) For lecture ppt files see http://obswww.unige.ch/saas-fee/preannouncement/course_pres/overview_f.htm

    Glucose time series complexity as a predictor of type 2 diabetes

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    Background Complexity analysis of glucose profile may provide valuable information about the gluco‐regulatory system. We hypothesized that a complexity metric (detrended fluctuation analysis, DFA) may have a prognostic value for the development of type 2 diabetes in patients at risk. Methods A total of 206 patients with any of the following risk factors (1) essential hypertension, (2) obesity or (3) a first‐degree relative with a diagnosis of diabetes were included in a survival analysis study for a diagnosis of new onset type 2 diabetes. At inclusion, a glucometry by means of a Continuous Glucose Monitoring System was performed, and DFA was calculated for a 24‐h glucose time series. Patients were then followed up every 6 months, controlling for the development of diabetes. Results In a median follow‐up of 18 months, there were 18 new cases of diabetes (58.5 cases/1000 patient‐years). DFA was a significant predictor for the development of diabetes, with ten events in the highest quartile versus one in the lowest (log‐rank test chi2 = 9, df = 1, p = 0.003), even after adjusting for other relevant clinical and biochemical variables. In a Cox model, the risk of diabetes development increased 2.8 times for every 0.1 DFA units. In a multivariate analysis, only fasting glucose, HbA1c and DFA emerged as significant factors. Conclusions Detrended fluctuation analysis significantly performed as a harbinger of type 2 diabetes development in a high‐risk population. Complexity analysis may help in targeting patients who could be candidates for intensified treatment.Sin financiación3.904 JCR (2017) Q2, 39/142 Endocrinology & MetabolismUE
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