61 research outputs found

    The detailed Middle to early Late Ordovician faunal succession and δ13Ccarbon chemistry of the Kårehamn drill core, offshore eastern Öland, Sweden: implications for stratigraphy and correlation

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    The Middle to lower Upper Ordovician stratigraphy of the KÃ¥rehamn core, drilled ca 7 km offshore to the east of the KÃ¥rehamn village, northeastern Ãland, is presented. The investigated core is one of four drill cores obtained during the preparation of the KÃ¥rehamn offshore wind farm. It is ca 41 m long and has a diameter of 10 cm. The lithostratigraphy, faunal (conodonts and chitinozoans) succession and δ13Ccarbon isotope chemistry pattern are built upon this complete core. The drilling stopped at 64.5 m b.s.l. in the Swedish Orthoceratite limestone, within the upper Lenodus variabilis Conodont Zone. The horizon is largely equivalent to the strata that in Sweden were previously named âlimestone with Asaphus âranicepsââ, which is within the Orthoceratite limestone. It is characterized by and composed of mainly light-grey, highly fossiliferous and stylolitic limestone with little clay material. The next unit includes the Yangtzeplacognathus crassus and lower Lenodus pseudoplanus conodont zones. The upper Lenodus pseudoplanus (with Microzarkodina ozarkodella late form sensu Lindström), Eoplacognathus suecicus and E. foliaceus conodont zones are recorded from the overlying succession of the upper Orthoceratite limestone. This interval corresponds to the Segerstad, Skärlöv and Seby topoformations of Jaanusson, all of which are included in the upper part of the Swedish Orthoceratite limestone. The prominent δ13Ccarbon isotope MDICE peak recorded from the KÃ¥rehamn drill core is biostratigraphically precisely assigned to the upper part of the newly redefined Eoplacognathus suecicus Conodont Zone. The conformably overlying Folkeslunda Limestone is the top unit of the Orthoceratite limestone; it is composed of lime mudstone and grey bedded wackestone. Biostratigraphically, it is referred to the Eoplacognathus reclinatus Subzone of the Pygodus serra Conodont Zone corresponding to the lower part of the Laufeldochitina striata Chitinozoan Zone. The Furudal Limestone â on Ãland known as the Källa Limestone and Persnäs Limestone â overlies the Orthoceratite limestone and represents an important change of the depositional environment in the Baltic Basin. The Källa Limestone contains the Eoplacognathus robustus Conodont Subzone of the Pygodus serra Conodont Zone and the Laufeldochitina striata Chitinozoan Zone. Pygodus protoanserinus Zhang is the transitional taxon from P. serra to P. anserinus and is securely and precisely recorded for the first time in the region. The important conodont species Pygodus anserinus Lamont and Lindström is recorded from the Persnäs Limestone (= upper Furudal Formation) from which also theLaufeldochitina striata Chitinozoan Zone is documented. Pygodus anserinus extends into the overlying Dalby Formation, in which it is succeeded by the lower Amorphognathus tvaerensis Conodont Zone. The diagnostic chitinozoans Eisenackitina rhenana, Laufeldochitina stentor, Conochitina savalaensis, Belonechitina intonsa and Conochitina viruana are well documented from the same formation. The top of the core is within the Baltoniodus variabilis Conodont Subzone of theAmorphognathus tvaerensis Conodont Zone of the Bergström conodont zonation. The precise integrated biostratigraphy of the conodonts and chitinozoans along with the carbon isotope curve are results of this study, which largely agree with those of previous research of the Baltic Basin and thus provide data for precise correlation across the Baltic Basin. The fossil assemblages are clearly related to the east Baltic chronostratigraphic scheme and to the new chronostratigraphic scheme of Scandinavia, and the succession is referred to the established stages of the two systems

    Herbivorous reptiles and body mass: Effects on food intake, digesta retention, digestibility and gut capacity, and a comparison with mammals

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    Differences in the allometric scaling between gut capacity (with body mass, BM1.00) and food intake (with BM0.75) should theoretically result in a scaling of digesta retention time with BM0.25 and therefore a higher digestive efficiency in larger herbivores. This concept is an important part of the so-called ‘Jarman-Bell principle’ (JBP) that explains niche differentiation along a body size gradient in terms of digestive physiology. Empirical data in herbivorous mammals, however, do not confirm the scaling of retention time, or of digestive efficiency, with body mass. Here, we test these concepts in herbivorous reptiles, adding data of an experiment that measured food intake, digesta retention, digestibility and gut capacity in 23 tortoises (Testudo graeca, T. hermanni , Geochelone nigra, G. sulcata, Dipsochelys dussumieri) across a large BM range (0.5-180 kg) to a literature data collection. While dry matter gut fill scaled to BM1.07 and dry matter intake to BM0.76, digesta mean retention time (MRT) scaled to BM0.17; the scaling exponent was not significantly different from zero for species > 1 kg. Food intake level was a major determinant of MRT across reptiles and mammals. In contrast to dietary fibre level, BM was not a significant contributor to dry matter digestibility in a General Linear Model. Digestibility coefficients in reptiles depended on diet nutrient composition in a similar way as described in mammals. Although food intake is generally lower and digesta retention longer in reptiles than in mammals, digestive functions scale in a similar way in both clades, indicating universal principles in herbivore digestive physiology. The reasons why the theoretically derived JBP has little empirical support remain to be investigated. Until then, the JBP should not be evoked to explain niche differentiation along a body size axis in terms of digestive physiology

    Hospital use of systemic antifungal drugs

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    BACKGROUND: Sales data indicate a major increase in the prescription of antifungal drugs in the last two decades. Many new agents for systemic use that only recently have become available are likely to be prescribed intensively in acute care hospitals. Sales data do not adequately describe the developments of drug use density. Given the concerns about the potential emergence of antifungal drug resistance, data on drug use density, however, may be valuable and are needed for analyses of the relationship between drug use and antifungal resistance. METHODS: Hospital pharmacy records for the years 2001 to 2003 were evaluated, and the number of prescribed daily doses (PDD, defined according to locally used doses) per 100 patient days were calculated to compare systemic antifungal drug use density in different medical and surgical service areas between five state university hospitals. RESULTS: The 3-year averages in recent antifungal drug use for the five hospitals ranged between 8.6 and 29.3 PDD/100 patient days in the medical services (including subspecialties and intensive care), and between 1.1 and 4.0 PDD/100 patient days in the surgical services, respectively. In all five hospitals, systemic antifungal drug use was higher in the hematology-oncology service areas (mean, 48.4, range, 24 to 101 PDD/100 patient days, data for the year 2003) than in the medical intensive care units (mean, 18.3, range, 10 to 33 PDD/100) or in the surgical intensive care units (mean, 10.7, range, 6 to 18 PDD/100). Fluconazole was the most prescribed antifungal drug in all areas. In 2003, amphotericin B consumption had declined to 3 PDD/100 in the hematology-oncology areas while voriconazole use had increased to 10 PDD/100 in 2003. CONCLUSION: Hematology-oncology services are intense antifungal drug prescribing areas. Fluconazole and other azol antifungal drugs are the most prescribed drugs in all patient care areas while amphotericin B use has considerably decreased. The data may be useful as a benchmark for focused interventions to improve prescribing quality

    Feeding enrichment by self-operated food boxes for white-fronted lemurs (Eulemur fulvus albifrons) in the Masoala exhibit of the Zurich Zoo

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    In the new Masoala exhibit of the Zurich Zoo four self-operated food boxes were installed to encourage arboreal behavior and higher activity levels, and to increase the attractiveness to visitors of a group of three white-fronted lemurs (Eulemur fulvus albifrons) and one Alaotran gentle lemur (Hapalemur griseus alaotrensis). Data obtained by direct observations with and without food boxes present were compared. In addition, visitors were surveyed to investigate attractiveness of the lemurs. Overall activity and locomotor behavior increased due to food box presentation. Furthermore, the visitor survey documented that the lemurs were spotted more often in trees when the food boxes were present. Because behavior patterns of the subjects approached natural levels with food boxes, the presentation of self-operated food boxes seems a valuable tool to improve the captive environment of lemurs

    Relevance of global forest change data set to local conservation: case study of forest degradation in Masoala National Park, Madagascar

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    Article first published online: 13 FEB 2015A global data set on forest cover change was recently published and made freely available for use (Hansen et al. 2013. Science 342: 850–853). Although this data set has been criticized for inaccuracies in distinguishing vegetation types at the local scale, it remains a valuable source of forest cover information for areas where local data is severely lacking. Masoala National Park, in northeastern Madagascar, is an example of a region for which very little spatially explicit forest cover information is available. Yet, this extremely diverse tropical humid forest is undergoing a dramatic rate of forest degradation and deforestation through illegal selective logging of rosewood and ebony, slash-and-burn agriculture, and damage due to cyclones. All of these processes result in relatively diffuse and small-scale changes in forest cover. In this paper, we examine to what extent Hansen et al.'s global forest change data set captures forest loss within Masoala National Park by comparing its performance to a locally calibrated, object-oriented classification approach. We verify both types of classification with substantial ground truthing. We find that both the global and local classifications perform reasonably well in detecting small-scale slash-and-burn agriculture, but neither performs adequately in detecting selective logging. We conclude that since the use of the global forest change data set requires very little technical and financial investment, and performs almost as well as the more resource-demanding, locally calibrated classification, it may be advantageous to use the global forest change data set even for local conservation purposes.Zuzana Burivalova, Martin R. Bauert, Sonja Hassold, Nandinanjakana T. Fatroandrianjafinonjasolomiovazo, and Lian Pin Ko

    Patterns of activity and body temperature of Aldabra giant tortoises in relation to environmental temperature

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    We studied the temperature relations of wild and zoo Aldabra giant tortoises (Aldabrachelys gigantea) focusing on (1) the relationship between environmental temperature and tortoise activity patterns (n = 8 wild individuals) and (2) on tortoise body temperature fluctuations, including how their core and external body temperatures vary in relation to different environmental temperature ranges (seasons; n = 4 wild and n = 5 zoo individuals). In addition, we surveyed the literature to review the effect of body mass on core body temperature range in relation to environmental temperature in the Testudinidae. Diurnal activity of tortoises was bimodally distributed and influenced by environmental temperature and season. The mean air temperature at which activity is maximized was 27.9°C, with a range of 25.8–31.7°C. Furthermore, air temperature explained changes in the core body temperature better than did mass, and only during the coldest trial, did tortoises with higher mass show more stable temperatures. Our results, together with the overall Testudinidae overview, suggest that, once variation in environmental temperature has been taken into account, there is little effect of mass on the temperature stability of tortoises. Moreover, the presence of thermal inertia in an individual tortoise depends on the environmental temperatures, and we found no evidence for inertial homeothermy. Finally, patterns of core and external body temperatures in comparison with environmental temperatures suggest that Aldabra giant tortoises act as mixed conformer–regulators. Our study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change

    Building 2D crystals from 5-fold-symmetric molecules

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    Concepts of close packing in monolayers of 5-fold-symmetric buckybowls are discussed. When the symmetry of lattice and molecular building blocks are incompatible, new strategies evolve. Corannulene forms a hexagonal lattice on Cu(111) by tilting away from the C5 symmetry and aligning one hexagonal ring parallel to the surface. The chiral 5-fold-substituted chloro and methyl derivatives do not show this tilt and maintain the 5-fold symmetry as adsorbates. Consequently, a nonperfect tiling is observed. Their lattices are quasi-hexagonal: one in an antiparallel fashion with almost pm symmetry and the other with azimuthal and positional disorder on the hexagonal grid. Our results are in remarkable agreement with computational and mechanical modeling experiments of close packing of hard pentagonal discs in macroscopic two-dimensional systems and prove the validity of such modeling strategies

    Polymorph selection in 2D crystals by phase transition blocking

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    A phase transition between two-dimensional polymorphs of the buckybowl corannulene on a Cu(111) surface can be suppressed by spatial confinement, allowing stabilisation of the metastable polymorph over the stable one

    Evaluation of artificial heating sources for the thermoregulation of Aldabra giant tortoises (Aldabrachelys gigantea) in Zurich zoo

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    We recorded the thermoregulatory patterns of five Aldabra giant tortoises (Aldabrachelys gigantea) (25–193 kg) during spring (ZRH spring trial), after the installation of a heating area (concrete heat pad and basking lamp) at Zurich Zoo, Switzerland. The measurements were compared to published results on the same tortoises observed prior to the installation of the heater (ZRH summer and winter trials), and on wild tortoises on Aldabra Atoll. The mean environmental temperature outside the heating area was 23.3 °C, significantly lower compared to Aldabra Atoll (30.3 °C; r ange: 23.8–43.8 °C), and to the environmental temperature range at which tortoises maximize their activity in the wild (Ta-opt; 25.8–31.7 °C). The heating area exhibited a mean temperature of 36.3 °C, and tortoises that made use of the heating area were able to maintain a mean core body temperature (Tbc) of 30.0 °C, which was comparable to the Tbc of tortoises during ZRH summer and on Aldabra trials, and an improvement over the mean Tbc recorded during the ZRH winter trial (21.2 °C). The smaller individuals reached the upper limits of Tbc recommended for the species, probably due to heating pad temperatures above Ta-opt.We discuss current practices to provide external heating sources for tortoises and how this method can be used to provide an adequate thermal environment for large captive reptiles. Finally, we provide recommendations for the installation of artificial heating sources for tortoises and large reptiles
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