Multi-wavelength environment of the Galactic globular cluster Terzan 5

Terzan 5 is a Galactic globular cluster exhibiting prominent X-ray and gamma-ray emission. Following the discovery of extended X- ray emission in this object, we explore here archival data at several wavelengths for other unexpected emission features in the vicinity of this globular cluster. Radio data from the Effelsberg 100 metre telescope show several extended structures near Terzan 5, albeit with large uncertainties in the flux estimates and no reliable radio spectral index. In particular, a radio source extending from the location of Terzan 5 to the north-west could result from long-term non-thermal electron production by the large population of milli-second pulsars in this globular cluster. Another prominent radio structure close to Terzan 5 may be explained by ionised material produced by a field O star. As for the diffuse X-ray emission found in Terzan 5, its extension appears to be limited to within 2.5 arcmin of the globular cluster and the available multi-wavelength data is compatible with an inverse Compton scenario but disfavours a non-thermal Bremsstrahlung origin.Comment: 8 pages, 4 figures. Accepted for publication in A&

Does soil erosion rejuvenate the soil phosphorus inventory?

Phosphorus (P) is an essential nutrient for life. Deficits in soil P reduce primary production and alter biodiversity. A soil P paradigm based on studies of soils that form on flat topography, where erosion rates are minimal, indicates P is supplied to soil mainly as apatite from the underlying parent material and over time is lost via weathering or transformed into labile and less-bioavailable secondary forms. However, little is systematically known about P transformation and bioavailability on eroding hillslopes, which make up the majority of Earth's surface. By linking soil residence time to P fractions in soils and parent material, we show that the traditional concept of P transformation as a function of time has limited applicability to hillslope soils of the western Southern Alps (New Zealand) and Northern Sierra Nevada (USA). Instead, the P inventory of eroding soils at these sites is dominated by secondary P forms across a range of soil residence times, an observation consistent with previously published soil P data. The findings for hillslope soils contrast with those from minimally eroding soils used in chronosequence studies, where the soil P paradigm originated, because chronosequences are often located on landforms where parent materials are less chemically altered and therefore richer in apatite P compared to soils on hillslopes, which are generally underlain by pre-weathered parent material (e.g., saprolite). The geomorphic history of the soil parent material is the likely cause of soil P inventory differences for eroding hillslope soils versus geomorphically stable chronosequence soils. Additionally, plants and dust seem to play an important role in vertically redistributing P in hillslope soils. Given the dominance of secondary soil P in hillslope soils, limits to ecosystem development caused by an undersupply of bio-available P may be more relevant to hillslopes than previously thought

The effectiveness of actively accumulating dust in rejuvenating soils and ecosystems in a super-humid, high weathering and leaching environment, West Coast, South Island, New Zealand

The deposition of mineral dust is an integral component of terrestrial and marine biogeochemical cycles. Dust is recognised as an important rejuvenator by supplying nutrients and unweathered mineral material to ecosystems. While deposition rates have been regularly quantified for terrestrial environments in the past, the rejuvenating effect of dust on soils and terrestrial ecosystems and the accessional processes have been rarely studied. This thesis addresses this gap by combining two environmental gradients, a dust-free chronosequence (170 to 6500 y) and a dust accumulation gradient on a 6500 y old surface (28 g m⁻² y⁻¹ to zero), located on the super-humid West Coast of the South Island, New Zealand. Across both gradients, soils were analysed for indicators of pedogenesis pathways (soil morphology, fractionation of pedogenic oxides, phosphorus (P) and particle sizes), and ecosystem fertility was evaluated by describing vegetation communities and foliar nutrient concentrations. Across the chronosequence, pedogenesis is characterised by rapid podsolisation including formation of distinct eluvial and illuvial horizons, high leaching losses of nutrients (Ca, K, Na, apatite P) and a rapid increase of secondary P fractions. This is followed by declining rates of change after the formation of Spodosols by 1000 y of pedogenesis. This soil fertility pattern is reflected in the vegetation by the presence of fertility-demanding species until the 1000 y old surface followed by a more persistent and less diverse species composition on the older surfaces. Foliar phosphorus concentrations decline rapidly within 2000 y towards levels similar to very old surfaces. The chronosequence is in agreement with progressive pedogenesis and ecosystem evolution driven by declining edaphic fertility. The pedogenesis response to increasing dust flux along the dust gradient is characterised by enhanced podsolisation as a result of upbuilding pedogenesis, which constantly resupplies the acidic topsoil with weatherable materials and forms upwardly growing illuvial horizons. As a result, pedogenic oxides and soil organic carbon increase with dust flux. Chemically, all dust-affected soils along the gradient follow a strongly progressive pedogenesis vector (Spodosols). Soil morphology, however, indicates regressive pedogenesis under the maximal dust flux rate where an Inceptisol has formed, indicating that soils can contain characteristics of both pedogenesis pathways, progressive and regressive, depending on the chosen soil property. As a result of burial by dust increments, the original, unweathered and nutrient-rich parent material becomes increasingly decoupled from the soil processes. This causes a decline of primary, apatite P (~50 to 3 g m⁻² 50 cm⁻¹) as the majority of mineral, dust-derived P is rapidly assimilated by the biota after deposition on the biologically and chemically most active topsoil. This is ultimately returned to the soil as organic P and then stored in the upper, most reactive and leached part of the soil, which raises the P content in these increments when compared to dust-free Spodosols (95 vs. 60 g m⁻² 30 cm⁻¹). The increase of ecosystem fertility in correlation with these processes is reflected by an increase of fertility-demanding species with dust flux, which is, however, not capable of maintaining vegetation suites characteristic of earlier stages of dust-free succession. Also, foliar P responds positively to the dust flux by an increase of up to 100% under the highest flux rate. When compared to the chronosequence, this concentration is equivalent to those of a ~90% younger chronosequence surface. The rejuvenation process by dust deposition is fundamentally different to nutrient accession by subsoil advection in dust-free soils and more effective, as dust is added directly to the part of the soil with the highest nutrient demand. The increase of a more stable, yet plantaccessible organic P pool may have significance in maintaining a higher long-term fertility after dust deposition has ceased. Dust significantly rejuvenates and fertilises soils and ecosystems in the study area but does not act equivalent to a backwards arrow in time. It instead induces characteristic accession processes and soil and ecosystem properties

Quantifying ecosystem rejuvenation: foliar nutrient concentrations and vegetation communities across a dust gradient and a chronosequence

Background and aims: Due to long-term weathering of land surfaces, aeolian nutrient contributions can become essential to maintain ecosystem fertility and avoid retrogression. However, studies that consider the qualitative and quantitative effects of dust deposition on ecosystem development are rare. We addressed this knowledge gap by studying an active Holocene dust flux gradient along a 6,500 year old dune ridge and a nearby chronosequence outside the influence of dust deposition in a super-humid, high leaching environment, on the west coast of the South Island in New Zealand. Methods: Along both sequences we measured foliar nutrients of two main tree species (Dacrydium cupressinum, Prumnopitys ferruginea) and analysed vegetation communities in survey plots. Results: Along the dust gradient, foliar phosphorus (P) concentrations increased up to 50 % with increasing dust flux. Across the nearby chronosequence a rapid decline of up to 50 % in foliar [P] occurred within the first 2,000 years after which it plateaued. At the highest dust flux rate, closest to the dust source, foliar [P] matched those of surfaces that are 5,702 to 6,098 years younger than the 6,500 year old dune. Vegetation communities along the dust gradient showed increasing relative abundance of species typical for successional communities on immature soils (Entisols, Inceptisols), while canopy cover and basal area (total, angiosperms, conifers) did not respond to increasing dust deposition. Tree fern basal area, however, positively responded to the dust flux. Conclusion: We conclude that naturally occurring dust deposition can fertilise ecosystems significantly, creating a foliar nutrient status normally found on land surfaces that are up to 94 % younger and vegetation communities that are typical for successional stages on young soils (Entisols, Inceptisols). We suspect that these observations mainly reflect more plant-available P in the ecosystem as a result of dust fertilisation. Thus, dust deposition can be an important mechanism to avoid or retard the development of an ecosystem toward natural retrogression. This is the first study to directly quantify the fertilising capacity of natural dust deposition by calibrating its rejuvenating effect against a well-dated successional vegetation sequence

The influence of erosion and vegetation on soil production and chemical weathering rates in the Southern Alps, New Zealand

This data repository contains Supplementary Tables S1 – S13 which mirror files hosted by the publisher. The repository additionally contains a 0.5 m digital elevation model (DEM) derived from historical aerial photographs using structure-from-motion and multiple raster files of topographic derivatives of the DEM. The topographic derivatives include a raster of slope, mean local relief, and 56 rasters of topographic curvature, calculated using different combinations of smoothing window sizes (0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 7.5, 10, and 12.5 m) and the number of grid cells used in the surfaces for which curvature was constructed (3, 5, 7, and 9 cells).https://scholarworks.umass.edu/data/1171/thumbnail.jp

Rapid Soil Production and Weathering in the Southern Alps, New Zealand

Evaluating conflicting theories about the influence of mountains on carbon dioxide cycling and climate requires understanding weathering fluxes from tectonically uplifting landscapes. The lack of soil production and weathering rate measurements in Earth’s most rapidly uplifting mountains has made it difficult to determine whether weathering rates increase or decline in response to rapid erosion. Beryllium-10 concentrations in soils from the western Southern Alps, New Zealand, demonstrate that soil is produced from bedrock more rapidly than previously recognized, at rates up to 2.5 millimeters per year. Weathering intensity data further indicate that soil chemical denudation rates increase proportionally with erosion rates. These high weathering rates support the view that mountains play a key role in global-scale chemical weathering and thus have potentially important implications for the global carbon cycle

Divergent profile of emerging cutaneous Leishmaniasis in subtropical Brazil: new endemic areas in the southern frontier.

Submitted by Luciane Willcox ([email protected]) on 2016-09-02T19:18:15Z No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5)Approved for entry into archive by Luciane Willcox ([email protected]) on 2016-09-02T19:37:00Z (GMT) No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5)Made available in DSpace on 2016-09-02T19:37:00Z (GMT). No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5) Previous issue date: 2013-02-14CAPES, FAPESC, PPSUS and CNPqUniversidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Secretaria Estadual de Saúde de Santa Catarina. Diretoria de Vigilância Epidemiológica. Departamento de Zoonoses. Florianópolis, SC, Brasil.Universidade do Vale do Itajaí. Centro de Ciências da Saúde. Itajaí, Brasil. / Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.Universidade do Vale do Itajaí. Centro de Ciências da Saúde. Itajaí, Brasil.Universidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil.Universidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil. / Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.BACKGROUND: Although known to be highly endemic in the Amazon regions of Brazil, the presence of cutaneous leishmaniasis (CL) in the subtropical southern part of the country has largely been ignored. This study was conducted to demonstrate CL is emerging in the Brazilian state of Santa Catarina, as well as to characterize the epidemiological profile and Leishmania species involved. METHODOLOGY/PRINCIPAL FINDINGS: For this cross-sectional study, data from all CL cases from Santa Catarina, Brazil, reported to the Brazilian National Notifiable Diseases Information System from 2001 to 2009 were investigated. Amplification of the kDNA minicircle conserved region followed by restriction fragment length polymorphism (PCR-RFLP) was conducted to screen for Leishmania species present in patient biopsy. Overall, 542 CL cases were reported, with majority resulting from autochthonous transmission (n = 401, 73.99%) and occurring in urban zones (n = 422, 77.86%). Age, gender, zone of residence, origin of case, clinical form and case outcome were found to differ significantly by region. Imported cases were over seven times more likely to relapse (95% CI 2.56-21.09). Mapping of cases revealed new endemic areas in northeastern Santa Catarina with two species present. With the exception of three L. (Leishmania) amazonensis cases (1.20%), majority of PCR positive samples were found to be L. (Viannia) braziliensis (n = 248, 98.80%). CONCLUSIONS/SIGNIFICANCE: CL is now endemic in the state of Santa Catarina, Brazil, with case profiles varying significantly by region. L. (V.) braziliensis has been identified as the predominant species in the region

Theoretical effect of hyperventilation on speed of recovery and risk of rehypnotization following recovery - a GasMan^® simulation

<p>Abstract</p> <p>Background</p> <p>Hyperventilation may be used to hasten recovery from general anesthesia with potent inhaled anesthetics. However, its effect may be less pronounced with the newer, less soluble agents, and it may result in rehypnotization if subsequent hypoventilation occurs because more residual anesthetic will be available in the body for redistribution to the central nervous system. We used GasMan^® simulations to examine these issues.</p> <p>Methods</p> <p>One MAC of isoflurane, sevoflurane, or desflurane was administered to a fictitious 70 kg patient for 8 h with normoventilation (alveolar minute ventilation [V_A] 5 L.min^-1), resulting in full saturation of the vessel rich group (VRG) and >95% saturation of the muscle group. After 8 h, agent administration was stopped, and fresh gas flow was increased to 10 L.min^-1 to avoid rebreathing. At that same time, we continued with one simulation where normoventilation was maintained, while in a second simulation hyperventilation was instituted (10 L.min^-1). We determined the time needed for the partial pressure in the VRG (F_VRG; representing the central nervous system) to reach 0.3 MAC (MACawake). After reaching MACawake in the VRG, several degrees of hypoventilation were instituted (V_A of 2.5, 1.5, 1, and 0.5 L.min^-1) to determine whether F_VRG would increase above 0.3 MAC(= rehypnotization).</p> <p>Results</p> <p>Time to reach 0.3 MAC in the VRG with normoventilation was 14 min 42 s with isoflurane, 9 min 12 s with sevoflurane, and 6 min 12 s with desflurane. Hyperventilation reduced these recovery times by 30, 18, and 13% for isoflurane, sevoflurane, and desflurane, respectively. Rehypnotization was observed with V_A of 0.5 L.min^-1 with desflurane, 0.5 and 1 L.min^-1 with sevoflurane, and 0.5, 1, 1.5, and 2.5 L.min^-1 with isoflurane. Only with isoflurane did initial hyperventilation slightly increase the risk of rehypnotization.</p> <p>Conclusions</p> <p>These GasMan^® simulations confirm that the use of hyperventilation to hasten recovery is marginally beneficial with the newer, less soluble agents. In addition, subsequent hypoventilation results in rehypnotization only with more soluble agents, unless hypoventilation is severe. Also, initial hyperventilation does not increase the risk of rehypnotization with less soluble agents when subsequent hypoventilation occurs. Well-controlled clinical studies are required to validate these simulations.</p