Multiple-crystal X-ray topographic characterization of periodically domain-inverted KTiOPO4 crystal

A periodically domain-inverted KTiOPO4 crystal has been characterized for the first time by multiple-crystal multiple-reflection x-ray topography. The striation contrast within the domain- inverted regions has been revealed in high strain-sensitivity reflection topographs. The origin of formation of the striation contrast and the mechanism of domain inversion in KTiOPO4 are discussed in terms of the structural characteristics of KTiOPO4

A high-performance integrated single-photon detector for telecom wavelengths

We have integrated a commercial avalanche photodiode (APD) and the circuitry needed to operate it as a single-photon detector (SPD) onto a single PC-board. At temperatures accessible with Peltier coolers (~200-240K), the PCB-SPD achieves high detection efficiency (DE) at 1308 and 1545 nm with low dark count probability (e.g. ~10-6/bias pulse at DE=20%, 220 K), making it useful for quantum key distribution (QKD). The board generates fast bias pulses, cancels noise transients, amplifies the signals, and sends them to an on-board discriminator. A digital blanking circuit suppresses afterpulsing.Comment: (10 pages, 6 figures

Solving the riddle of codon usage preferences: a test for translational selection

Translational selection is responsible for the unequal usage of synonymous codons in protein coding genes in a wide variety of organisms. It is one of the most subtle and pervasive forces of molecular evolution, yet, establishing the underlying causes for its idiosyncratic behaviour across living kingdoms has proven elusive to researchers over the past 20 years. In this study, a statistical model for measuring translational selection in any given genome is developed, and the test is applied to 126 fully sequenced genomes, ranging from archaea to eukaryotes. It is shown that tRNA gene redundancy and genome size are interacting forces that ultimately determine the action of translational selection, and that an optimal genome size exists for which this kind of selection is maximal. Accordingly, genome size also presents upper and lower boundaries beyond which selection on codon usage is not possible. We propose a model where the coevolution of genome size and tRNA genes explains the observed patterns in translational selection in all living organisms. This model finally unifies our understanding of codon usage across prokaryotes and eukaryotes. Helicobacter pylori, Saccharomyces cerevisiae and Homo sapiens are codon usage paradigms that can be better understood under the proposed model

Growth Environment and Sex Differences in Lipids, Body Shape and Diabetes Risk

Background. Sex differences in lipids and body shape, but not diabetes, increase at puberty. Hong Kong Chinese are mainly first or second generation migrants from China, who have shared an economically developed environment for years, but grew up in very different environments in Hong Kong or contemporaneously undeveloped Guangdong, China. We assessed if environment during growth had sex-specific associations with lipids and body shape, but not diabetes. Methodology and Principal Findings. We used multivariable regression in a population-based cross-sectional study, undertaken from 1994 to 1996, of 2537 Hong Kong Chinese residents aged 25 to 74 years with clinical measurements of ischaemic heart disease (IHD) risk, including HDL-cholesterol, ApoB, diabetes and obesity. Waist-hip ratio was higher ( mean difference 0.01, 95% CI 0.001 to 0.02) in men, who had grown up in an economically developed rather than undeveloped environment, as was apolipoprotein B (0.05 g/L, 95% CI 0.001 to 0.10), adjusted for age, socio-economic status and lifestyle. In contrast, the same comparison was associated in women with lower waist-hip ratio (20.01, 95% CI 20.001 to 20.02) and higher HDL-cholesterol ( 0.05 mmol/L, 95% CI 0.0004 to 0.10). The associations in men and women were significantly different (p-values, 0.001). There were no such differences for diabetes. Conclusions. Growth in a developed environment with improved nutrition may promote higher sex-steroids at puberty producing an atherogenic lipid profile and male fat pattern in men but the opposite in women, with tracking of increased male IHD risk into adult life

Fractional allele loss data indicate distinct genetic populations in the development of non-small-cell lung cancer.

Allelic imbalance or loss of heterozygosity (LOH) has been widely used to assess genetic instability in tumours, and high LOH on chromosome arms 3p, 9p and 17p has been considered to be a common event in non-small-cell lung cancer (NSCLC). We have investigated allelic imbalance in 45 NSCLCs using 92 microsatellite markers on 38 chromosome arms. LOH of 38% was observed on 3p using nine markers, 58% on 9p using 15 markers and 38% on 17p using five markers. Fractional allele loss (FAL) has been calculated for each tumour (FAL is the number of chromosome arms showing LOH/number of informative chromosome arms) and a median FAL value of 0.09 was obtained in the 45 NSCLCs studied. The LOH data were examined on the basis of FAL scores: low FAL (LFAL) (0.00-0.04), medium FAL (MFAL) (0.05-0.13) and high FAL (HFAL) (0.14-0.45) based symmetrically around the median FAL value of 0.09. Tumours with HFAL values showed a very clear polarisation of the LOH data on chromosome arms 3p, 9p and 17p, such that 80% showed loss on 3p, 80% on 9p and 73% on 17p. These incidences of LOH were significantly higher than would be expected, since overall genetic instability in these HFAL tumours ranged from 14% to 45% LOH. Nine of the 14 patients in the LFAL group were found to have no LOH on 3p, 9p or 17p, but five of these had LOH at other sites: i.e. LOH on 5p, 5q, 8p, 13q, 16q and 19q. These results indicate that LFAL patients form a new subset of NSCLC tumours with distinct molecular-initating events, and may represent a discrete genetic population

Prediction of photoperiodic regulators from quantitative gene circuit models

Photoperiod sensors allow physiological adaptation to the changing seasons. The external coincidence hypothesis postulates that a light-responsive regulator is modulated by a circadian rhythm. Sufficient data are available to test this quantitatively in plants, though not yet in animals. In Arabidopsis, the clock-regulated genes CONSTANS (CO) and FLAVIN, KELCH, F-BOX (FKF1) and their lightsensitive proteins are thought to form an external coincidence sensor. We use 40 timeseries of molecular data to model the integration of light and timing information by CO, its target gene FLOWERING LOCUS T (FT), and the circadian clock. Among other predictions, the models show that FKF1 activates FT. We demonstrate experimentally that this effect is independent of the known activation of CO by FKF1, thus we locate a major, novel controller of photoperiodism. External coincidence is part of a complex photoperiod sensor: modelling makes this complexity explicit and may thus contribute to crop improvement

The Association of Hemoglobin A1c With Incident Heart Failure Among People Without Diabetes: The Atherosclerosis Risk in Communities Study

OBJECTIVE-This study sought to investigate an association of HbA1c (A1C) with incident heart failure among individuals without diabetes and compare it to fasting glucose. RESEARCH DESIGN AND METHODS-We studied 11,057 participants of the Atherosclerosis Risk in Communities (ARIC) Study without heart failure or diabetes at baseline and estimated hazard ratios of incident heart failure by categories of A1C (<5.0, 5.0-5.4 [reference], 5 5-59, and 6.0-6.4%) and fasting glucose (<90, 90-99 [reference], 100-109, and 110-125 mg/dl) using Cox proportional hazards models. RESULTS-A total of 841 cases of incident heart failure hospitalization or deaths (International Classification of Disease, 9th/10th Revision, 428/150) occurred during a median follow-up of 14.1 years (incidence rate 5.7 per 1,000 person-years). After the adjustment for covariates including fasting glucose, the hazard ratio of incident heart failure was higher in individuals with A1C 6.0-6.4% (1.40 [95% CI, 1 09-1.79]) and 5.5-6.0% (1.16 [0.98-1 37]) as compared with the reference group. Similar results were observed when adjusting for insulin level or limiting to heart failure cases without preceding coronary events or developed diabetes during follow-up. In contrast, elevated fasting glucose was not associated with heart failure after adjustment for covariates and A1C. Similar findings were observed when the top quartile (A1C, 5.7-6.4%, and fasting glucose, 108-125 mg/dl) was compared with the lowest quartile (<5 2% and <95 mg/dl, respectively). CONCLUSIONS-Elevated A1C (>= 5.5-6 0%) was associated with incident heart failure in a middle-aged population without diabetes, suggesting that chronic hyperglycemia prior to the development of diabetes contributes to development of heart failure. Diabetes 59:2020-2026, 2010National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55015]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55016]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55018]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55019]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55020]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55021]National Heart, Lung, and Blood Institute (NHLBI/NIH)[N01-HC-55022]NIH/NIDDK[R21-DK-080294]NIH/NIDDK[K01-DK-076595]NIH/NIDDK[R01-DK-076770]NIH/NHLBI[5T32-HL-007024

Panethnic differences in blood pressure in Europe : a systematic review and meta-analysis

Background: People of Sub Saharan Africa (SSA) and South Asians(SA) ethnic minorities living in Europe have higher risk of stroke than native Europeans(EU). Study objective is to provide an assessment of gender specific absolute differences in office systolic(SBP) and diastolic(DBP) blood pressure(BP) levels between SSA, SA, and EU. Methods and Findings: We performed a systematic review and meta-analysis of observational studies conducted in Europe that examined BP in non-selected adult SSA, SA and EU subjects. Medline, PubMed, Embase, Web of Science, and Scopus were searched from their inception through January 31st 2015, for relevant articles. Outcome measures were mean SBP and DBP differences between minorities and EU, using a random effects model and tested for heterogeneity. Twenty-one studies involving 9,070 SSA, 18,421 SA, and 130,380 EU were included. Compared with EU, SSA had higher values of both SBP (3.38 mmHg, 95% CI 1.28 to 5.48 mmHg; and 6.00 mmHg, 95% CI 2.22 to 9.78 in men and women respectively) and DBP (3.29 mmHg, 95% CI 1.80 to 4.78; 5.35 mmHg, 95% CI 3.04 to 7.66). SA had lower SBP than EU(-4.57 mmHg, 95% CI -6.20 to -2.93; -2.97 mmHg, 95% CI -5.45 to -0.49) but similar DBP values. Meta-analysis by subgroup showed that SA originating from countries where Islam is the main religion had lower SBP and DBP values than EU. In multivariate meta-regression analyses, SBP difference between minorities and EU populations, was influenced by panethnicity and diabetes prevalence. Conclusions: 1) The higher BP in SSA is maintained over decades, suggesting limited efficacy of prevention strategies in such group in Europe;2) The lower BP in Muslim populations suggests that yet untapped lifestyle and behavioral habits may reveal advantages towards the development of hypertension;3) The additive effect of diabetes, emphasizes the need of new strategies for the control of hypertension in groups at high prevalence of diabetes

Radiocarbon evidence for annual growth rings in a deep sea octocoral (Primnoa resedaeformis)

The deep-sea gorgonian octocoral Primnoa resedaeformis is distributed throughout the Atlantic and Pacific Oceans at depths of 65-3200 m. It has a two-part skeleton of calcite and gorgonin. Towards the inside of the axial skeleton gorgonin and calcite are deposited in concentric growth rings, similar to tree rings. Colonies were collected from the Northeast Channel (northwest Atlantic Ocean, southwest of Nova Scotia, Canada) from depths of 250-475 m. Radiocarbon was measured in individual rings isolated from sections of each colony, after dissolution of calcite. Each {Delta}{sup 14}C measurement was paired with a ring age determined by three amateur ring counters. The precision of ring counts averaged better than {+-} 2 years. Accurate reconstruction of 20th century bomb-radiocarbon shows that (1) the growth rings are formed annually, (2) the gorgonin is derived from surface particulate organic matter (POM) and (3) useful environmental data are recorded in the organic endoskeletons of deep-sea octocorals. These results support the use of Primnoa resedaeformis as a long-term, high resolution monitor of surface ocean conditions, particularly in temperate and boreal environments where proxy data are lacking