Acquisition of Ca2+ and HCO3−/CO32− for shell formation in embryos of the common pond snail Lymnaea stagnalis

Embryos of the freshwater common pond snail Lymnaea stagnalis develop to hatch within 10 days under control conditions (22°C, Miami-Dade tap water) and this development is impaired by removal of ambient calcium. In contrast, embryos did not exhibit dependence upon an ambient HCO3−/CO32− source, developing and hatching in HCO3−/CO32−-free water at rates comparable to controls. Post-metamorphic, shell-laying embryos exhibited a significant saturation-type calcium uptake as a function of increasing ambient calcium concentration. However, changes in ambient bicarbonate concentration did not influence calcium or apparent titratable alkalinity uptake. There was a distinct shift from no significant flux in pre-metamorphic embryos to net uptake of calcium in post-metamorphic stages as indicated by an increased uptake from the micro-environment surrounding the egg mass and increased net uptake in 24-h, whole egg mass flux measurements. Furthermore, HCO3−/CO32− acquisition as measured by titratable alkalinity flux is at least partially attributable to an endogenous carbonate source that is associated with acid extrusion. Thus, calcium requirements for embryonic shell formation are met via uptake but HCO3−/CO32−, which is also necessary for shell formation is acquired in part from endogenous sources with no detectable correlation to ambient HCO3−/CO32− availability

PreCam, a Precursor Observational Campaign for Calibration of the Dark Energy Survey

PreCam, a precursor observational campaign supporting the Dark Energy Survey (DES), is designed to produce a photometric and astrometric catalog of nearly a hundred thousand standard stars within the DES footprint, while the PreCam instrument also serves as a prototype testbed for the Dark Energy Camera (DECam)'s hardware and software. This catalog represents a potential 100-fold increase in Southern Hemisphere photometric standard stars, and therefore will be an important component in the calibration of the Dark Energy Survey. We provide details on the PreCam instrument's design, construction and testing, as well as results from a subset of the 51 nights of PreCam survey observations on the University of Michigan Department of Astronomy's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory. We briefly describe the preliminary data processing pipeline that has been developed for PreCam data and the preliminary results of the instrument performance, as well as astrometry and photometry of a sample of stars previously included in other southern sky surveys.Comment: 21 pages, 15 figures, submitted to PAS

Medium-term health of seniors following exposure to a natural disaster

The article aims to describe the medium-term impacts of a major earthquake event (Chile, February 27, 2010) on 26 seniors. The authors adopted a qualitative study approach. Data obtained using the Impact of Event Scale–Revised (IES-R) show the presence of manifestations of posttraumatic stress in the majority of respondents. In addition, data collected in interviews demonstrated a progressive deterioration of the health of respondents over a period of 4 years following the disaster. Seniors are particularly vulnerable to the effects of material loss, emotional stress, and postdisaster health complications. These impacts are exacerbated by low economic status. Furthermore, broader research is necessary involving elderly living in poverty who have survived natural disasters and others without such experiences, in order to better identify and differentiate between health complications associated with exposure to disaster events and those linked more strictly with natural aging processes

Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C i lines, and the C iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C ii counterparts were found, even though the optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C i compared to the weaker optical C ii appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a "transitional" event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. There is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si iiλ0.6355 μm line, implying a long dark phase of ∼4 days. © 2015 ESO

Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge.

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations. The results of the challenge suggest that methods selected by the 14 teams participating in the challenge can provide high correlations between estimated and ground-truth connectivity weights, in complex numerical environments. Additionally, the methods used by the participating teams were able to accurately identify the binary connectivity of the numerical dataset. However, specific false positive and false negative connections were consistently estimated across all methods. Although the challenge dataset doesn't capture the complexity of a real brain, it provided unique data with known macrostructure and microstructure ground-truth properties to facilitate the development of connectivity estimation methods

Global Variation of Nutritional Status in Children Undergoing Chronic Peritoneal Dialysis : A Longitudinal Study of the International Pediatric Peritoneal Dialysis Network

While children approaching end-stage kidney disease (ESKD) are considered at risk of uremic anorexia and underweight they are also exposed to the global obesity epidemic. We sought to investigate the variation of nutritional status in children undergoing chronic peritoneal dialysis (CPD) around the globe. The distribution and course of body mass index (BMI) standard deviation score over time was examined prospectively in 1001 children and adolescents from 35 countries starting CPD who were followed in the International Pediatric PD Network (IPPN) Registry. The overall prevalence of underweight, and overweight/obesity at start of CPD was 8.9% and 19.7%, respectively. Underweight was most prevalent in South and Southeast Asia (20%), Central Europe (16.7%) and Turkey (15.2%), whereas overweight and obesity were most common in the Middle East (40%) and the US (33%). BMI SDS at PD initiation was associated positively with current eGFR and gastrostomy feeding prior to PD start. Over the course of PD BMI SDS tended to increase on CPD in underweight and normal weight children, whereas it decreased in initially overweight patients. In infancy, mortality risk was amplified by obesity, whereas in older children mortality was markedly increased in association with underweight. Both underweight and overweight are prevalent in pediatric ESKD, with the prevalence varying across the globe. Late dialysis start is associated with underweight, while enteral feeding can lead to obesity. Nutritional abnormalities tend to attenuate with time on dialysis. Mortality risk appears increased with obesity in infants and with underweight in older children.Peer reviewe

Erratum: The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions (2017, AJ, 154, 211)

GalaxiesStars and planetary system

Recurrence of nephrotic syndrome following kidney transplantation is associated with initial native kidney biopsy findings

Background and objectives: Steroid-resistant nephrotic syndrome (SRNS) due to focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) is a leading cause of end-stage kidney disease in children. Recurrence of primary disease following transplantation is a major cause of allograft loss. The clinical determinants of disease recurrence are not completely known. Our objectives were to determine risk factors for recurrence of FSGS/MCD following kidney transplantation and factors that predict response to immunosuppression following recurrence. Methods: Multicenter study of pediatric patients with kidney transplants performed for ESKD due to SRNS between 1/2006 and 12/2015. Demographics, clinical course, and biopsy data were collected. Patients with primary-SRNS (PSRNS) were defined as those initially resistant to corticosteroid therapy at diagnosis, and patients with late-SRNS (LSRNS) as those initially responsive to steroids who subsequently developed steroid resistance. We performed logistic regression to determine risk factors associated with nephrotic syndrome (NS) recurrence. Results: We analyzed 158 patients; 64 (41%) had recurrence of NS in their renal allograft. Disease recurrence occurred in 78% of patients with LSRNS compared to 39% of those with PSRNS. Patients with MCD on initial native kidney biopsy had a 76% recurrence rate compared with a 40% recurrence rate in those with FSGS. Multivariable analysis showed that MCD histology (OR; 95% CI 5.6; 1.3–23.7) compared to FSGS predicted disease recurrence. Conclusions: Pediatric patients with MCD and LSRNS are at higher risk of disease recurrence following kidney transplantation. These findings may be useful for designing studies to test strategies for preventing recurrence

Clinimetric evaluation of active range of motion measures in patients with non-specific neck pain: a systematic review

The study is to provide a critical analysis of the research literature on clinimetric properties of instruments that can be used in daily practice to measure active cervical range of motion (ACROM) in patients with non-specific neck pain. A computerized literature search was performed in Medline, Cinahl and Embase from 1982 to January 2007. Two reviewers independently assessed the clinimetric properties of identified instruments using a criteria list. The search identified a total of 33 studies, investigating three different types of measurement instruments to determine ACROM. These instruments were: (1) different types of goniometers/inclinometers, (2) visual estimation, and (3) tape measurements. Intra- and inter-observer reliability was demonstrated for the cervical range of motion instrument (CROM), Cybex electronic digital instrument (EDI-320) and a single inclinometer. The presence of agreement was assessed for the EDI-320 and a single inclinometer. The CROM received a positive rating for construct validity. When clinical acceptability is taken into account both the CROM and the single inclinometer can be considered appropriate instruments for measuring the active range of motion in patients with non-specific neck pain in daily practice. Reliability is the aspect most frequently evaluated. Agreement, validity and responsiveness are documented less frequently