529 research outputs found

    Diurnal defecation rate of moose in southwest Finland

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    An accurate measure of defecation rate is essential for application of pellet group counts in moose (Alces alces) population estimates. We measured the wintertime, diurnal defecation rate of moose by tracking 7 GPS-collared and 22 uncollared moose in southwest Finland. The mean defecation rate was 23.5 ± 4.2 pellet groups/d, one of the highest values reported. The mean defecation rate did not differ between the tracking methods (GPS vs. uncollared moose); limited sample size precluded conclusions about sex and age differences. The defecation rate was not correlated with calendar week, length of accumulation period, or number of diurnal beds. Our results are appropriate for use in southwest Finland when using the pellet group method to assess moose population density

    Kara and Barents sea ice thickness estimation based on CryoSat-2 radar altimeter and Sentinel-1 dual-polarized synthetic aperture radar

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    We present a method to combine CryoSat-2 (CS2) radar altimeter and Sentinel-1 synthetic aperture radar (SAR) data to obtain sea ice thickness (SIT) estimates for the Barents and Kara seas. From the viewpoint of tactical navigation, along-track altimeter SIT estimates are sparse, and the goal of our study is to develop a method to interpolate altimeter SIT measurements between CS2 ground tracks. The SIT estimation method developed here is based on the interpolation of CS2 SIT utilizing SAR segmentation and segmentwise SAR texture features. The SIT results are compared to SIT data derived from the AARI ice charts; to ORAS5, PIOMAS and TOPAZ4 ocean-sea ice data assimilation system reanalyses; to combined CS2 and Soil Moisture and Ocean Salinity (SMOS) radiometer weekly SIT (CS2SMOS SIT) charts; and to the daily MODIS (Moderate Resolution Imaging Spectro-radiometer) SIT chart. We studied two approaches: CS2 directly interpolated to SAR segments and CS2 SIT interpolated to SAR segments with mapping of the CS2 SIT distributions to correspond to SIT distribution of the PIOMAS ice model. Our approaches yield larger spatial coverage and better accuracy compared to SIT estimates based on either CS2 or SAR data alone. The agreement with modelled SIT is better than with the CS2SMOS SIT. The average differences when compared to ice models and the AARI ice chart SIT were typically tens of centimetres, and there was a significant positive bias when compared to the AARI SIT (on average 27 cm) and a similar bias (24 cm) when compared to the CS2SMOS SIT. Our results are directly applicable to the future CRISTAL mission and Copernicus programme SAR missions.Peer reviewe

    Sub-ppb detection of formaldehyde with cantilever enhanced photoacoustic spectroscopy using quantum cascade laser source

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    Abstract A novel cantilever enhanced photoacoustic spectrometer with mid-infrared quantum cascade laser was applied for selective and sensitive formaldehyde (CH 2 O) gas measurement. The spectrum of formaldehyde was measured from 1,772 to 1,777 cm -1 by tuning the laser with a spectral resolution of 0.018 cm -1 . The band at 1,773.959 cm -1 was selected for data analysis, at which position the laser emitted 47 mW. In univariate measurement, the detection limit (3r, 0.951 s) and the normalized noise equivalent absorption coefficient (3r) for amplitude modulation (AM) were 1.6 ppbv and 7.32 9 10 -10 W cm -1 (Hz) -1/2 and for wavelength modulation (WM) 1.3 ppbv and 6.04 9 10 -10 W cm -1 (Hz) -1/2 . In multivariate measurement, the detection limit (3r) can be as low as 901 pptv (1,773.833-1,774.085 cm -1 , 15 spectral points each 0.951 s) for AM and 623 pptv (1,773.743-1,774.265 cm -1 , 30 spectral points each 0.951 s) for WM. Because measurement time increases in multivariate measurement, its application is justified only when interferents need to be resolved. Potential improvements of the system are discussed

    Subpolar Southern Ocean response to changes in the surface momentum, heat, and freshwater fluxes under 2xCO2

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    The Antarctic subpolar Southern Ocean (sSO) has fundamental climate importance. Antarctic Bottom Water (AABW) originates in the sSO and supplies the lower limb of the meridional overturning circulation (MOC), occupying 36% of ocean volume. Climate models struggle to represent continental shelf processes that form AABW. We explore sources of persistent model biases by examining response of the sSO to perturbations in surface forcing in a global ocean–sea ice model (ACCESS-OM2) that forms AABW both on shelf and in open ocean. The sSO response to individual and combined perturbations of surface heat, freshwater, and momentum fluxes follows the WCRP CMIP6 FAFMIP-protocol. Wind perturbation (i.e., a poleward shift and intensification of the westerlies) is dominant, enhancing AABW formation and accelerating the global MOC. This occurs through upwelling of warm waters and inhibition of sea ice growth during winter, which triggers large open water polynya (OWP) events with associated deep convection. These events occur in the Weddell and Ross Seas and their variability is associated with availability of heat at midocean depths. These OWPs cease when the heat reservoir is depleted. Effects of surface warming and freshening only partially compensate changes from increasing winds on ocean stratification and depletion of AABW formation. These results indicate that overly convective models, such ACCESS-OM2, can respond to CO2-perturbed scenarios by forming too much AABW in OWP, which might not hold in models without OWPs. This might contribute to the large intermodel spread thermosteric sea level projections, being relevant to the interpretation of future projections by current climate models.Peer reviewe

    The Clinical Frailty Scale is a useful tool for predicting postoperative complications following elective colon cancer surgery at the age of 80 years and above: A prospective, multicentre observational study

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    Aim Identification of the risks of postoperative complications may be challenging in older patients with heterogeneous physical and cognitive status. The aim of this multicentre, observational study was to identify variables that affect the outcomes of colon cancer surgery and, especially, to find tools to quantify the risks related to surgery. Method Patients aged >= 80 years with electively operated Stage I-III colon cancer were recruited. The prospectively collected data included comorbidities, results of the onco-geriatric screening tool (G8), Clinical Frailty Scale (CFS), Charlson Comorbidity Index (CCI) and Mini Nutritional Assessment-Short Form (MNA-SF), and operative and postoperative outcomes. Results A total of 161 patients (mean 84.5 years, range 80-97, 60% female) were included. History of cerebral stroke (64% vs. 37%, p = 0.02), albumin level 31-34 g/l compared with >= 35 g/l (57% vs. 32%, p = 0.007), CFS 3-4 and 5-9 compared with CFS 1-2 (49% and 47% vs. 16%, respectively) and American Society of Anesthesiologists score >3 (77% vs. 28%, P = 0.006) were related to a higher risk of complications. In multivariate logistic regression analysis CFS >= 3 (OR 6.06, 95% CI 1.88-19.5, p = 0.003) and albumin level 31-34 g/l (OR 3.88, 1.61-9.38, p = 0.003) were significantly associated with postoperative complications. Severe complications were more common in patients with chronic obstructive pulmonary disease (43% vs. 13%, p = 0.047), renal failure (25% vs. 12%, p = 0.021), albumin level 31-34 g/l (26% vs. 8%, p = 0.014) and CCI >6 (23% vs. 10%, p = 0.034). Conclusion Surgery on physically and cognitively fit aged colon cancer patients with CFS 1-2 can lead to excellent operative outcomes similar to those of younger patients. The CFS could be a useful screening tool for predicting postoperative complications.Peer reviewe

    Dysfunction of complement receptors CR3 (CD11b/18) and CR4 (CD11c/18) in pre-eclampsia : a genetic and functional study

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    Objective To study genetic variants and their function within genes coding for complement receptors in pre-eclampsia. Design A case-control study. Setting Pre-eclampsia is a common vascular disease of pregnancy. The clearance of placenta-derived material is one of the functions of the complement system in pregnancy. Population We genotyped 500 women with pre-eclamptic pregnancies and 190 pregnant women without pre-eclampsia, as controls, from the FINNPEC cohort, and 122 women with pre-eclamptic pregnancies and 1905 controls from the national FINRISK cohort. Methods The functional consequences of genotypes discovered by targeted exomic sequencing were explored by analysing the binding of the main ligand iC3b to mutated CR3 or CR4, which were transiently expressed on the surface of COS-1 cells. Main outcome measures Allele frequencies were compared between pre-eclamptic pregnancies and controls in genetic studies. The functional consequences of selected variants were measured by binding assays. Results The most significantly pre-eclampsia-linked CR3 variant M441K (P = 4.27E-4, OR = 1.401, 95% CI = 1.167-1.682) displayed a trend of increased adhesion to iC3b (P = 0.051). The CR4 variant A251T was found to enhance the adhesion of CR4 to iC3b, whereas W48R resulted in a decrease of the binding of CR4 to iC3b. Conclusions Results suggest that changes in complement-facilitated phagocytosis are associated with pre-eclampsia. Further studies are needed to ascertain whether aberrant CR3 and CR4 activity leads to altered pro- and anti-inflammatory cytokine responses in individuals carrying the associated variants, and the role of these receptors in pre-eclampsia pathogenesis. Tweetable abstract Genetic variants of complement receptors CR3 and CR4 have functional consequences that are associated with pre-eclampsia.Peer reviewe

    Fire in Australian savannas: From leaf to landscape

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    © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd. Savanna ecosystems comprise 22% of the global terrestrial surface and 25% of Australia (almost 1.9 million km2) and provide significant ecosystem services through carbon and water cycles and the maintenance of biodiversity. The current structure, composition and distribution of Australian savannas have coevolved with fire, yet remain driven by the dynamic constraints of their bioclimatic niche. Fire in Australian savannas influences both the biophysical and biogeochemical processes at multiple scales from leaf to landscape. Here, we present the latest emission estimates from Australian savanna biomass burning and their contribution to global greenhouse gas budgets. We then review our understanding of the impacts of fire on ecosystem function and local surface water and heat balances, which in turn influence regional climate. We show how savanna fires are coupled to the global climate through the carbon cycle and fire regimes. We present new research that climate change is likely to alter the structure and function of savannas through shifts in moisture availability and increases in atmospheric carbon dioxide, in turn altering fire regimes with further feedbacks to climate. We explore opportunities to reduce net greenhouse gas emissions from savanna ecosystems through changes in savanna fire management
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