Significant salinity anomalies have been observed in the Arctic Ocean surface layer during the last decade. Our study is based on an extensive gridded dataset of winter salinity in the upper 50 m layer of the Arctic Ocean for the periods 1950–1993 and 2007–2012, obtained from ~20 000 profiles. We investigate the interannual variability of the salinity fields, identify predominant patterns of anomalous behavior and leading modes of variability, and develop a statistical model for the prediction of surface-layer salinity. The statistical model is based on linear regression equations linking the principal components of surface-layer salinity obtained through empirical orthogonal function decomposition with environmental factors, such as atmospheric circulation, river runoff, ice processes and water exchange with neighboring oceans. Using this model, we obtain prognostic fields of the surface-layer salinity for the winter period 2013–2014. The prognostic fields generated by the model show tendencies of surface-layer salinification, which were also observed in previous years. Although the used data are proprietary and have gaps, they provide the most spatiotemporally detailed observational resource for studying multidecadal variations in basin-wide Arctic salinity. Thus, there is community value in the identification, dissemination and modeling of the principal modes of variability in this salinity record.

We present the results of stable carbon and nitrogen isotope analyses of bone collagen and bone bioapatite from the ancient Maya center of Minanha, Belize (ca. 100 B.C. to A.D. 1260). The purpose of this research was to reconstruct diet and investigate the influence of sociopolitical and environmental factors. Overall, diet was relatively stable over time, with maize being a staple in all periods. Maize consumption reached its peak in the transitional Early to Middle Classic periods and decreased over time. When isotope data from dry periods were compared to normal periods, there were no significant differences, although comparisons of isotope data by burial location and type suggest that the apical or ruling elite consumed a more diverse diet, with more animal protein, relative to the lesser elites. The temporal variability in maize consumption seems best explained by sociopolitical factors documented at Minanha and within the Vaca Plateau. This study demonstrates the resilience of ancient subsistence practices in the face of climatic instability and highlights the impact that social and political factors can have on diet and subsistence economy.

Because individuals develop dementia as a manifestation of neurodegenerative or neurovascular disorder, there is a need to develop reliable approaches to their identification. We are undertaking an observational study (Ontario Neurodegenerative Disease Research Initiative [ONDRI]) that includes genomics, neuroimaging, and assessments of cognition as well as language, speech, gait, retinal imaging, and eye tracking. Disorders studied include Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson’s disease, and vascular cognitive impairment. Data from ONDRI will be collected into the Brain-CODE database to facilitate correlative analysis. ONDRI will provide a repertoire of endophenotyped individuals that will be a unique, publicly available resource.

The Compton Gamma-Ray Observatory (C-GRO) has completed a full-sky survey during which the number of known γ-ray pulsars has more than doubled. COMPTEL has observed the classical pulsars Crab and Vela on several occasions and has derived detailed pulse patterns and spectral parameters in the 0.7-30 MeV energy interval. The new C-GRO γ-ray pulsars have different properties in terms of energy spectra and light-curve shapes, and, in fact, only the Crab is seen by all four C-GRO instruments. This raises intriguing questions about the particle acceleration processes and beaming taking place in the neutron magnetosphere. We have examined the COMPTEL data to add information on these objects in the 0.7-30 MeV energy interval and present evidence for the detection of one of them, PSR B1509-58. We have also undertaken a search for candidate radio pulsars whose ephemerides are well defined. The results of these analyses are presented.

Subject headings: gamma rays: observations — pulsars: general

N-acetyl-glutamate synthase (NAGS) deficiency is a rare autosomal recessive urea cycle disorder (UCD) that uncommonly presents in adulthood. Adult presentations of UCDs include; confusional episodes, neuropsychiatric symptoms and encephalopathy. To date, there have been no detailed neurological descriptions of an adult onset presentation of NAGS deficiency. In this review we examine the clinical presentation and management of UCDs with an emphasis on NAGS deficiency. An illustrative case is provided. Plasma ammonia levels should be measured in all adult patients with unexplained encephalopathy, as treatment can be potentially life-saving. Availability of N-carbamylglutamate (NCG; carglumic acid) has made protein restriction largely unnecessary in treatment regimens currently employed. Genetic counselling remains an essential component of management of NAGS.

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005–2006 were asked to participate in a cross-sectional study. Household members aged ⩾12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.

Heterojunction p++ GeSi / Si internal photoemission (HIP) detectors deposited by ultra high vacuum chemical vapor deposition (UHV/CVD) were investigated as alternatives to silicide Schottky-barrier type detectors for infrared focal plane arrays. HIP structures were grown using SiH4, GeH4, and B2H6 source gases on (100) p- Si substrates patterned with thermal oxide windows. Selective epitaxy was maintained over a range of boron concentrations (6×1019 – 6.5×1020 cm-3) and Ge fractions (0.38–0.50), and a maximum selective thickness of ~300Å was determined for silicon growth at 550°C. These structures were fabricated into IR detectors using techniques compatible with standard Si focal plane array processing technology. Photoresponse data were analyzed according to the modified Fowler equation, indicating cut-off wavelengths of 5–12 (μm) and Cl values of 8–21 (%/eV) depending on sample parameters. I(V) characteristics were also measured at various temperatures, yielding electrical barrier heights consistent with optical measurements.

The miniaturization of electrochemical transducers is crucial for the development of implantable biosensors, wearable microdetectors, and remote sensing networks due to the small dimensions required in these applications. As sensors scale, the analytical response degrades and integrated instrumentation is required to maintain acceptable detection limits. This work details the development of CMOS-integrated liquid chemical sensors. The sensors were cost-effectively post-processed on top of foundry-fabricated CMOS electronics using thin-film techniques. CMOS-integrated voltammetric sensors demonstrated a 25x improvement in detection limit/electrode area versus passive sensors. CMOS-integrated, ion-selective electrodes demonstrated a 50x improvement in lifetime and a 200x improvement in response time versus passive sensors. With their improved performance, these smart sensors can be used in a wide range of applications and can additionally serve as enabling technologies for more complex, chip-scale systems.