Climate-driven sea level anomalies modulate coastal groundwater dynamics and discharge

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 2701–2706, doi:10.1002/grl.50192.To better understand the physical drivers of submarine groundwater discharge (SGD) in the coastal ocean, we conducted a detailed field and modeling study within an unconfined coastal aquifer system. We monitored the hydraulic gradient across the coastal aquifer and movement of the mixing zone over multiple years. At our study site, sea level dominated over groundwater head as the largest contributor to variability in the hydraulic gradient and therefore SGD. Model results indicate the seawater recirculation component of SGD was enhanced during summer while the terrestrial component dominated during winter due to seasonal changes in sea level driven by a combination of long period solar tides, temperature and winds. In one year, sea level remained elevated year round due to a combination of ENSO and NAO climate modes. Hence, predicted changes in regional climate variability driven sea level may impact future rates of SGD and biogeochemical cycling within coastal aquifers.This work is a result of research sponsored by the NSF Chemical Oceanography program (OCE- 0425061 to M.C. and A.M. and OCE-0751525 to M.C.) and an NDSEG graduate fellowship (to M.G.).2013-12-0

Conservation of structure and mechanism in primary and secondary transporters exemplified by SiaP, a sialic acid binding virulence factor from Haemophilus influenzae

Extracytoplasmic solute receptors (ESRs) are important components of solute uptake systems in bacteria, having been studied extensively as parts of ATP binding cassette transporters. Herein we report the first crystal structure of an ESR protein from a functionally characterized electrochemical ion gradient-dependent secondary transporter. This protein, SiaP, forms part of a tripartite ATP-independent periplasmic transporter specific for sialic acid in Haemophilus influenzae. Surprisingly, the structure reveals an overall topology similar to ATP binding cassette ESR proteins, which is not apparent from the sequence, demonstrating that primary and secondary transporters can share a common structural component. The structure of SiaP in the presence of the sialic acid analogue 2,3-didehydro-2-deoxyN-acetylneuraminic acid reveals the ligand bound in a deep cavity with its carboxylate group forming a salt bridge with a highly conserved Arg residue. Sialic acid binding, which obeys simple bimolecular association kinetics as determined by stopped-flow fluorescence spectroscopy, is accompanied by domain closure about a hinge region and the kinking of an alpha-helix hinge component. The structure provides insight into the evolution, mechanism, and substrate specificity of ESR-dependent secondary transporters that are widespread in prokaryotes

Multipoint, high time resolution galactic cosmic ray observations associated with two interplanetary coronal mass ejections

[1] Galactic cosmic rays (GCRs) play an important role in our understanding of the interplanetary medium (IPM). The causes of their short timescale variations, however, remain largely unexplored. In this paper, we compare high time resolution, multipoint space-based GCR data to explore structures in the IPM that cause these variations. To ensure that features we see in these data actually relate to conditions in the IPM, we look for correlations between the GCR time series from two instruments onboard the Polar and INTEGRAL (International Gamma Ray Astrophysical Laboratory) satellites, respectively inside and outside Earth\u27s magnetosphere. We analyze the period of 18–24 August 2006 during which two interplanetary coronal mass ejections (ICMEs) passed Earth and produced a Forbush decrease (Fd) in the GCR flux. We find two periods, for a total of 10 h, of clear correlation between small-scale variations in the two GCR time series during these 7 days, thus demonstrating that such variations are observable using space-based instruments. The first period of correlation lasted 6 h and began 2 h before the shock of the first ICME passed the two spacecraft. The second period occurred during the initial decrease of the Fd, an event that did not conform to the typical one- or two-step classification of Fds. We propose that two planar magnetic structures preceding the first ICME played a role in both periods: one structure in driving the first correlation and the other in initiating the Fd

Developing a gender-based approach to chronic conditions and women's health: A qualitative investigation of communitydwelling women and service provider perspectives

© 2015 DiGiacomo et al. Background: Chronic conditions contribute to over 70 % of Australia's total disease burden, and this is set to increase to 80 % by 2020. Women's greater longevity means that they are more likely than men to live with disability and have unique health concerns related to their gender based roles in society. Cultural and social issues can impact on women's health and are important to consider in health services planning and research. In this study, we aimed to identify barriers and facilitators to providing a gender-based approach to chronic conditions and women's health in an eastern metropolitan region of Australia. Methods: Focus groups were used to engage both community-dwelling women who had chronic conditions and relevant professional stakeholders in the target area. Recorded proceedings underwent thematic analysis. Results: Five focus groups were conducted with professional stakeholders and women community members in February and March 2014. Resultant themes included: women's disempowerment through interactions with health systems; social and economic constraints and caregiving roles act to exclude women from participating in self-care and society; and empowerment can be achieved through integrated models of care that facilitate voice and enable communication and engagement. Conclusions: This study underscores the importance of including perspectives of sex and gender in health care services planning. Tailoring services to socio-demographic and cultural groups is critical in promoting access to health care services. Unique epidemiological trends, particularly the ageing of women and new migrant groups, require particular attention

Pretransplant Fasting Glucose Predicts New-Onset Diabetes after Liver Transplantation

New-onset diabetes after transplantation (NODAT) is common after liver transplant and associated with poorer outcomes. The aim of this study was to identify risk factors for NODAT in liver transplant recipients off corticosteroids. In 225 adult nondiabetic liver transplant recipients, the mean age was 51.7 years, the majority were men (71%), and half had HCV (49%). The mean calculated MELD score at transplantation was 18.7, and 19% underwent living-donor transplant (LDLT). One year after transplantation, 17% developed NODAT, and an additional 16% had impaired fasting glucose. The incidence of NODAT in patients with HCV was 26%. In multivariate analysis, HCV, pretransplant FPG, and LDLT were significant. Each 10 mg/dL increase in pretransplant FPG was associated with a twofold increase in future development of NODAT. The incidence of NODAT after liver transplant in patients off corticosteroids is 17%. Risk factors for developing NODAT include HCV and pretransplant FPG; LDLT is protective

Successful Transplantation of a Split Crossed Fused Ectopic Kidney into a Patient with End-Stage Renal Disease

Potential donors with congenital renal anomalies but normal renal function are often overlooked because of a possible increase in technical difficulty and complications associated with the surgery. However, as the waiting list for a deceased donor kidney transplant continues to grow, it is important to consider these kidneys for potential transplant. This paper describes the procurement of a crossed fused ectopic kidney, and subsequent parenchymal transection prior to transplantation as part of a combined simultaneous kidney pancreas transplant. The transplant was uncomplicated, and the graft had immediate function. The patient is now two years from transplant with excellent function