52 research outputs found

    Wolf spider burrows from a modern saline sandflat in central Argentina: Morphology, taphonomy and clues for recognition of fossil examples

    Get PDF
    Pavocosa sp. (Lycosidae) burrows found in an open sparsely vegetated area on the edge of the Gran Salitral saline lake, in central Argentina, are described. Burrows were studied by capturing the occupant and casting them with dental plaster. The hosting sediments and vegetation were also characterized. Inhabited Pavocosa sp. burrows display distinctive features as open, cylindrical, nearly vertical, silk lined shafts about 120 mm long, subcircular entrances, a gradual downward widening, and a particularly distinctive surface ornamentation in the form of sets of two linear parallel marks at a high angle to the burrow axis. Instead, casts of vacated Pavocosa sp. burrows showed some disturbances caused either by the reoccupation by another organism or by predation of the dweller. Two morphologies are related to reoccupation of burrows: those with a structure in form of an ``umbrella'' and another with smaller excavations at the bottom of the burrow. Predation by small mammals produces funnel-shaped burrows. Both active and abandoned Pavocosa sp. burrow casts are compared with existing ichnogenera and inorganic sedimentary structures, highlighting its distinction. It is argued that key features like the presence of a neck, a downward widening and the described surface texture will allow recognition of wolf spider burrows in the fossil record. However, the putative spider burrows described in the literature either lack the necessary preservational quality or do not show ornamentation similar to the modern wolf spider burrows. Fossil wolf spiders are recorded since the Paleogene (possibly Late Cretaceous), therefore Cenozoic continental rocks can contain wolf spider burrows awaiting recognition. In addition, the particular distribution of Pavocosa sp. in saline lakes may imply that this type of burrow is linked to saline environments.Fil: Mendoza Belmontes, Fatima del Rosario. Ministerio de Ciencia, Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica. Fondo para la Investigación Científica y Tecnológica; Argentina. Universidad Nacional de La Pampa; ArgentinaFil: Melchor, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Piacentini, Luis Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

    Get PDF
    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

    Get PDF
    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Application of vertebrate trace fossils to palaeoenvironmental analysis

    Get PDF
    This is a review of the main uses of vertebrate trace fossils, ichnofabrics and ichnofacies in the palaeoenvironmental analysis of sedimentary sequences. The article accounts for the significant developments produced in the last three decades, including the application of the ichnofacies concept to vertebrate trace fossils. Recognition of footprints in cross-sectional view and their distinction from inorganic structures and burrow fills, is first discussed. The response of different substrates, showing contrasting water content and imprinted by different animals or devices, is compared in terms of the morphology of the resultant footprint. Trackways with sand crescents are typical of aeolian cross-strata and are absent in associated flat-lying to low-angle deposits. Thick packages of highly bioturbated sandy dune and interdune sediments have been interpreted as reflecting periods of increased rainfall. Neoichnological observations in modern lake basins suggest that distinct zones can be recognized in the margins of fossil ponds and lakes, including onshore, shoreline and shallow subaqueous zones. Abundant flamingo-like footprints and flamingo nest mounds are good indicators of alkaline and/or saline lake waters. Hippopotamus trails are found closely associated with modern and fossil freshwater wetlands. Dinosaur and pterosaur swim traces from lacustrine and fluvial deposits can be used to estimate water depth. Turtle, crocodile, amphibian, hippopotamus and fish swim traces allow one to infer a subaqueous substrate. Certain modern intertidal fish feeding traces are oriented with the predominant tidal current and can be used as palaeocurrent indicators. The preferential orientation of tetrapod trackways in lacustrine and fluvial deposits is analyzed. Vertebrate trace fossils can help to infer discharge variability in fluvial channels. The descriptions of vertebrate ichnofabrics are commonly limited to heavily bioturbated beds due to trampling by vertebrates, and to a few examples of ichnofabrics with discrete trace fossils. The nature and implications of the recognized vertebrate ichnofacies are still being debated and have a limited utility in palaeoenvironmental analysis. The distinction of a potential vertebrate burrow ichnofacies in carbonate-bearing palaeosols is proposed to represent well-drained soils, developed under arid or semiarid climate.Fil: Melchor, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

    Changing lake dynamics and sequence stratigraphy of synrift lacustrine strata in a half-graben: An example from the Triassic Ischigualasto-Villa Unión Basin, Argentina

    No full text
    Well-exposed Triassic rift strata from the Ischigualasto-Villa Unión Basin (NW Argentina) include a 80 to ca 515 m thick lacustrine-dominated package that can be correlated across a half-graben using key stratigraphic surfaces (sequence boundaries, lacustrine flooding surfaces and forced regressive surfaces). The characteristics of the synrift lacustrine fill in different parts of the half-graben have been examined and the mechanisms controlling sedimentation inferred. A variety of sedimentary environments are recognized including; volcaniclastic floodplain, mildly saline lake and playa lake, offshore lacustrine, delta front to fluvial-dominated and wave-dominated deltas, distributary and fluvial channel, and interdistributary bay. The succession can be divided into four stratigraphic sequences (SS1 to SS4), the oldest of which (SS1) contains volcaniclastic, fluvial and saline lake deposits; it is thickest close to the western border fault zone, reflecting more rapid subsidence here. Accommodation exceeded sediment and water input during SS1. The second and third sequences (SS2 and SS3) mark the onset of widespread lacustrine sedimentation, reflecting a balance between accommodation creation and water and sediment fluxes. Sequences SS2 and SS3 are represented by offshore meromictic lacustrine and deltaic deposits, the latter mostly sourced from the flexural and southern axial margins of the half-graben. The presence of stacked parasequences bound by lacustrine flooding surfaces is related to climatically induced lake-level fluctuations superimposed on variable rates of subsidence on the controlling rift border fault zone. The youngest sequence (SS4) is represented by the deposits of littoral lacustrine and shallow shelf deltas distinguished by a change in lithofacies, palaeocurrents and sandstone composition, suggesting a switch in sediment supply to the footwall margin to the NW. The change in the sediment source is related to reduced footwall uplift, the possible presence of a relay ramp and/or supply from a captured antecedent drainage network. During SS4, the rate of creation of accommodation was exceeded by the sediment and water discharge. The stratigraphic evolution of lacustrine strata in the half-graben was mainly controlled by tectonic processes, including subsidence rate and the growth and evolution of the border fault zone, but changing climate (inducing changes in water balance and lake level) and autocyclic processes (delta lobe switching) were also important.Fil: Melchor, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

    Bird tracks preserved in fluvial channel facies of the Río Negro Formation (Neogene), La Pampa Province, Argentina

    Get PDF
    The vertebrate ichnofauna of the Neogene Río Negro Formation is composed of abundant mammal footprints and rare bird footprints. This ichnofauna has been extensively recorded from sea cliff exposures located south of the mouth, and also on the margin of the Negro river downstream of Carmen de Patagones city (figure 1). One of the remarkable aspects of this ichnofauna is the presence of trackways of large mammals, including those named as Megatherichnium oportoi Casamiquela, 1974, which provides evidence for bipedal locomotion in Megatherioidea (Casamiquela, 1974, Leonardi, 1994; Casinos, 1996). The tracks of other large mammals display a lower quality of preservation and have been recognized as Macrauchenichnus rector Casamiquela in Angulo and Casamiquela, 1982 and cf. Mylodontidichnum Aramayo and Manera de Bianco, 1987 (Angulo and Casamiquela, 1982; Aramayo, 1999; Aramayo et al., 2004). The materials used to erect other ichnotaxa of possible large mammals are poorly preserved tracks or undertracks and the status of that ichnotaxa is uncertain. This is the case of Falsatorichnum calceocannabius and Caballichnus impersonalis, which were tentatively assigned to Megatherioidea and Equidae by Casamiquela (in Angulo and Casamiquela, 1982). The remaining mammal trace fossils are Porcellusignum conculcator Casamiquela, in Angulo and Casamiquela, 1982 (purported Hydrochoeridae tracks); large meniscated burrows (compared by Casamiquela with Octodontidae burrows), and a digitigrade trackway assigned to a carnivorous marsupial (Angulo and Casamiquela, 1982; Leonardi, 1994; Aramayo et al., 2004). The record of bird tracks are restricted to one undertrack assigned to a phororhacid from the vicinity of El Cóndor town (Aramayo et al., 2004) and undetermined tracks of small birds found near Ingeniero Jacobacci (Casamiquela, 1969, p. 308; Leonardi, 1994, p. 35), both from Río Negro province. Despite that the outcrops of the Río Negro Formation cover a large area in Buenos Aires, Río Negro and La Pampa provinces, no findings of continental trace fossils have been reported for other localities. The purpose of this communication is to describe, to assign ichnotaxonomically, and to infer the paleoenvironmental significance of small bird tracks from outcrops of the Río Negro Formation at La Adela town, La Pampa province.Fil: Melchor, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

    Neogene paleoenvironmental evolution of the Northern Patagonian extra-Andean foreland basin, Argentina

    No full text
    This paper includes a detailed sedimentologic and stratigraphic analysis of the fill of the western part of the Neogene Northern Patagonian extra-Andean foreland basin of Argentina. Using facies analysis, stratigraphic relationships, independent age indicators and physical correlation between sections, the depositional history of the basin is reconstructed and linked to regional climatic and tectonic events. The fill of the basin comprises the El Sauzal, Barranca de los Loros, El Palo, Bayo Mesa and Río Negro formations and it reaches up to 60 m thick in outcrop. On the basis of fourteen detailed sedimentologic logs located in the western side of the basin, a total of nine facies associations are recognized: braided permanent fluvial channel belt, pedogenized floodplain, shallow floodplain lakes, eolian dune field, alkaline lake, saline lake, shallow freshwater lake, and permanent braided gravelly channel belt facies associations. Basin sediments were deposited on an erosive unconformity on Late Cretaceous/Paleocene to early Eocene sedimentary rocks and are divided into five depositional episodes. The first depositional episode is represented by a shallow freshwater lacustrine system of local occurrence, tentatively assigned to the late Miocene. The second depositional episode is represented by permanent braided sandy fluvial system that occurred in the late Miocene-early Pliocene in a depression from the center and south of the study area. The large rivers of this episode flowed toward the east and northeast. The third depositional episode is represented from south to north by ephemeral fluvial, eolian dune and saline-alkaline lacustrine deposits that were recorded in all sections and is tentatively assigned to the Pliocene. Eolian dunes migrated toward the northeast and east. The fourth depositional episode is composed of permanent sandy braided fluvial deposits occurring only in the center of the study area. The fifth depositional episode (early Pleistocene?) is represented by permanent braided gravelly fluvial deposits that rests on a regional erosive unconformity interpreted as a large fluvial fan sourced from the south. These deposits resulted calcretized prior to the middle Pleistocene. The paleoclimatic evolution suggest a wetter period (depositional episodes 1 and 2) tentatively linked to the middle member of the Río Negro Formation and the Paranense transgression, followed by a progressive aridization during the Pliocene and Pleistocene.Fil: Espinoza, Nahuel Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Melchor, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin
    corecore