The effect of protein backbone hydration on the amide vibrations in Raman and Raman optical activity spectra

Raman and specifically Raman optical activity (ROA) spectroscopy are very sensitive to the solution structure and conformation of biomolecules. Because of this strong conformational sensitivity, density functional theory (DFT) calculations are often used to get a better understanding of the experimentally observed spectral patterns. While e.g. for carbohydrate structure the water molecules that surround the solute have been demonstrated to be of vital importance to get accurate modelled ROA spectra, the effect of explicit water molecules on the calculated ROA patterns of peptides and proteins is less well studied. Here, the effect of protein backbone hydration was studied using DFT calculations of HCO-(l-Ala)(5)-NH2 in specific secondary structure conformations with different treatments of the solvation. The effect of the explicit water molecules on the calculated spectra mainly arises from the formation of hydrogen bonds with the amide C?O and N-H groups. Hydrogen bonding of water with the C?O group determines the shape and position of the amide I band. The C?O bond length increases upon formation of C?OH2O hydrogen bonds. The effect of the explicit water molecules on the amide III vibrations arises from hydrogen bonding of the solvent with both the C?O and N-H group, but their contributions to this spectral region differ: geometrically, the formation of a C?OH2O bond decreases the C-N bond length, while upon forming a N-HH2O hydrogen bond, the N-H bond length increases

Feeding practices and growth among young children during two seasons in rural Ethiopia

BACKGROUND: The use of indices of infant and young child feeding practices to predict growth has generated inconsistent results, possibly through age and seasonal confounding. The aim of this study was to evaluate the association of a dietary diversity score (DDS) and infant and child feeding index (ICFI) with growth among young children in a repeated cross-sectional and a follow-up study in two distinct seasons in rural southwest Ethiopia. METHODS: We used a repeated cross-sectional design comparing child feeding practices to nutritional status in 6–12 month old children during harvest (HS; n = 320) and pre-harvest season (PHS; n = 312). In addition, 6–12 month old children from the HS were reassessed 6 months later during PHS. In addition to child anthropometry, child feeding practices were collected using 24-h and 7-day dietary recalls. RESULTS: The mean (±SD) length-for-age z-score (LAZ) of the 6–12 month old children was −0.77 (±1.4) and −1.0 (±1.3) in HS and PHS, respectively, while the mean (±SD) of the follow-up children in PHS was −1.0 (±1.3). The median DDS (IQR) was 2.0 (1.0, 3.0.), 2.0 (2.0, 3.0) and 3.0 (2.0, 4.0) for the children in HS, PHS and the follow-up children in PHS, respectively. The DDS in HS was positively associated with LAZ at follow-up (β = 0.16; 95% CI: 0.01, 0.30; P = 0.03) after controlling for confounding factors. ICFI and DDS were not associated with mean LAZ, weight-for-height z-score and weight-for-age z-score within season. However, the odds of being stunted when having a DDS ≤ 2 was 2.3 times (95% CI: 1.10, 4.78; P = 0.03) higher compared to a DDS > 2 child in HS and 1.7 times (95% CI: 1.04, 2.71; P = 0.04) higher for the pooled sample of 6–12 months old children in HS and PHS. CONCLUSIONS: The DDS was found to be an indicator for child stunting during the Ethiopian harvest season. The DDS can be an appropriate tool to evaluate the association of child feeding practices with child growth irrespective of season. Inclusion of other dimensions in the construction of ICFI should be considered in future analysis as we found no association with growth

Bidecadal Thermal Changes in the Abyssal Ocean

A dynamically consistent state estimate is used for the period 1992–2011 to describe the changes in oceanic temperatures and heat content, with an emphasis on determining the noise background in the abyssal (below 2000 m) depths. Interpretation requires close attention to the long memory of the deep ocean, implying that meteorological forcing of decades to thousands of years ago should still be producing trendlike changes in abyssal heat content. Much of the deep-ocean volume remained unobserved. At the present time, warming is seen in the deep western Atlantic and Southern Oceans, roughly consistent with those regions of the ocean expected to display the earliest responses to surface disturbances. Parts of the deeper ocean, below 3600 m, show cooling. Most of the variation in the abyssal Pacific Ocean is comparatively featureless, consistent with the slow, diffusive approach to a steady state expected there. In the global average, changes in heat content below 2000 m are roughly 10% of those inferred for the upper ocean over the 20-yr period. A useful global observing strategy for detecting future change has to be designed to account for the different time and spatial scales manifested in the observed changes. If the precision estimates of heat content change are independent of systematic errors, determining oceanic heat uptake values equivalent to 0.1 W m−2 is possibly attainable over future bidecadal periods.Earth and Planetary Science

How to use the Democratic Dashboard

Democratic Audit UK recently launched the Democratic Dashboard, a new online tool which seeks to give voters completely impartial and accurate information about their local constituency which might be helpful to them in making up their own minds about how to vote at the 2015 general election. Here, Carl Cullinane and Patrick Dunleavy explain how to use the site

Dietary contribution of wild edible plants to women's diets in the buffer zone around the Lama forest, Benin : an underutilized potential

Rural populations in developing countries face food insecurity and malnutrition despite being surrounded by extraordinary biodiversity. The international community increasingly recognizes the role of agro-biodiversity and Wild Edible Plants (WEPs) in their contributions to managing risk and building resilience and sustainable food systems. Studies on real contributions of WEPs to peoples’ diets, however, are uncommon. This study assessed the contribution ofWEPs to diets of women living in the buffer zone of the Lama forest in southern Benin. During the long dry season, a cross-sectional survey was carried out on 120 women, covering their knowledge and attitudes towards WEPs and two non-consecutive 24-h recalls of their WEP consumption. Contribution ofWEPs to total dietary intake was low due to infrequent use and small portion sizes. The highest nutrient contributions of WEPs measured were for copper (13.9 %) and iron (4.6%) but the majority of the women had intake values below the Estimated Average Requirements (EARs) for these elements - copper 65 % and iron 91 % Women’s dietary diversity was significantly higher among WEP consumers than non-consumers, mainly due to higher consumption of dark green leafy vegetables. WEPs were less consumed as a replacement for other foods but rather as a complement to the diet. The study population generally appreciated WEPs, while some constraints were reported regarding preparation, conservation and commercialization. Before widely promoting WEP consumption in order to exploit their dietary potential, additional investigations are needed into their nutrient composition, cultural and market value, their sustainable harvest levels and possible integration into innovative farming systems

What are cirrus point sources?

Most cirrus point sources are associated with interstellar gas. A subset of these was isolated, together with other sources showing large band 4 to 3 flux density ratios, that are not associated with interstellar gas. Most of the point sources are associated with diffuse cirrus emissions. The sources appear to be distributed randomly on the sky, with the exception of six clusters, one of which is not associated with any known object. Six sources out of seventeen that were observed for redshifted H I at Arecibo were found to be associated with relatively nondescript external galaxies. Most of the sources do not appear on the Palomar Sky Survey. Deep optical observations of eight fields revealed some fairly distant galaxies, one object with a very peculiar optical spectrum, and several blank fields

The JPL telerobot operator control station. Part 2: Software

The Operator Control Station of the Jet Propulsion Laboratory (JPL)/NASA Telerobot Demonstrator System provides the man-machine interface between the operator and the system. It provides all the hardware and software for accepting human input for the direct and indirect (supervised) manipulation of the robot arms and tools for task execution. Hardware and software are also provided for the display and feedback of information and control data for the operator's consumption and interaction with the task being executed. The software design of the operator control system is discussed