Correction to: In vitro cellular and proteome assays identify Wnt pathway and CDKN2A-regulated senescence affected in mesenchymal stem cells from mice after a chronic LD gamma irradiation in utero

Radiation and Environmental Biophysics -     

A Prospective Epidemiological Study of Acute Mountain Sickness in Nepalese Pilgrims Ascending to High Altitude (4380 m)

Background

Each year, thousands of pilgrims travel to the Janai Purnima festival in Gosainkunda, Nepal (4380 m), ascending rapidly and often without the aid of pharmaceutical prophylaxis.

Methods

During the 2012 Janai Purnima festival, 538 subjects were recruited in Dhunche (1950 m) before ascending to Gosainkunda. Through interviews, subjects provided demographic information, ratings of AMS symptoms (Lake Louise Scores; LLS), ascent profiles, and strategies for prophylaxis.

Results

In the 491 subjects (91% follow-up rate) who were assessed upon arrival at Gosainkunda, the incidence of AMS was 34.0%. AMS was more common in females than in males (RR = 1.57; 95% CI = 1.23, 2.00), and the AMS incidence was greater in subjects >35 years compared to subjects ≤35 years (RR = 1.63; 95% CI = 1.36, 1.95). There was a greater incidence of AMS in subjects who chose to use garlic as a prophylactic compared to those who did not (RR = 1.69; 95% CI = 1.26, 2.28). Although the LLS of brothers had a moderate correlation (intraclass correlation = 0.40, p = 0.023), sibling AMS status was a weak predictor of AMS.

Conclusions

The incidence of AMS upon reaching 4380 m was 34% in a large population of Nepalese pilgrims. Sex, age, and ascent rate were significant factors in the development of AMS, and traditional Nepalese remedies were ineffective in the prevention of AMS.     

Biomass and Total Lipid Content Assessment of Microalgal Cultures Using Near and Short Wave Infrared Spectroscopy

The technique of near and short wave near-infrared spectroscopy was assessed with respect to analysis of dry matter and lipid content of microalgae with potential for biodiesel production. Microalgal culture samples were filtered through GF/C filter papers and spectral measurements of wet and oven dried (60 °C overnight) filter papers over the ranges of 300–1,100 nm and 1,100–2,500 nm were recorded. Partial least square models on culture biomass and lipid content for combined species data were poor in terms of RMSECV, R _CV and the ratio of RMSECV to SD. A single species model for C. vulgaris based on 1,100–2,500 nm spectra of dry filtrate supported a model with RMSECV, R _CV and SDR values of 0.32 g L^?1, 0.955 and 3.38 for biomass and 0.089 g L^?1, 0.874 and 2.06 with lipid, respectively. However, the dry filtrate models on biomass and lipid content performed poorly in the prediction of samples drawn from an independent series of C. vulgaris cultured under N-, P- and Fe-limited growth trial. Thus, while the near-infrared spectroscopy technique has potential for assessment of dry matter and lipid content of microalgal cultures using a dried filtrate sample, further work is required to examine the limits to model robustness.     

Heritability of brachydactyly type A3 in children, adolescents, and young adults from an endogamous population in eastern Nepal

Brachymesophalangia-V (BMP-V), a short and broad middle phalanx of the fifth digit, is the most common of all skeletal anomalies of the hand. When this feature appears alone, it is clinically known as brachydactyly type A3 (BDA3). A high prevalence of BDA3 has been observed among the children of the Jirel ethnic group in eastern Nepal. As part of the Jiri Growth Study, a hand-wrist radiograph is taken annually of each child to assess skeletal development. For this study the most recent radiographs of 1,357 Jirel children, adolescents, and young adults (676 boys, 681 girls), age 3-20 years, were examined for the presence or absence of BDA3, to report the prevalence and estimate the heritability of BDA3 in the Jirel population. The overall prevalence of BDA3 in this sample was 10.5% (12.9% of the males and 8.9% of the females were classified as BDA3 affected). The additive genetic heritability of BDA3 was statistically significant in this sample (h2 +/- SE = 0.87 +/- 0.16, p < 0.0001). This study is the first to estimate the prevalence and heritability of BDA3 in a large South Asian family-based sample.     

Effects of N-deficiency and timing of N supply on the recovery and distribution of labeled 15N in contrasting maize hybrids

Little information exists on the pattern of nitrogen (N) uptake, remobilization and N use efficiency (NUE) in Leafy and stay-green (SG) maize (Zea mays L.) genotypes. A pot experiment was conducted under controlled nutrition and growing conditions to determine the response of Leafy and SG maize genotypes to different levels of N-deficiency and timing of N supply. Three contrasting maize hybrids, Pioneer 3905 (a conventional hybrid with moderate SG characteristics), Pioneer 39F06 Bt (with a high score of SG trait) and Maizex LF850-RR (with a Leafy trait) were grown in 6 L plastic pots. Five different N treatments [no supply of N until V8 (N₁), no supply of N after V8 (N₂), no supply of N after silking (N₃), no supply of N beyond 3 weeks after silking (N₄), and continuous N supply from emergence to physiological maturity (N₅; standard check)] were imposed through modified Hoagland solution applied manually. Labeled ¹⁵N of 5% ¹⁵N₂–NH₄NO₃fertilizer was applied at 3 g per pot at the start of each schedule N treatment. Total amounts of N applied in different treatments were 3.13, 1.32, 1.90, 2.63 and 3.40 g, respectively in N₁, N₂, N₃, N₄ and N₅. Dry matter, N concentration, ¹⁵N (atom% enrichment) and NUE were determined in roots, stalk, leaves and grains at crop maturity. The three contrasting hybrids did not differ in grain yield, total N acquisition, partitioning of ¹⁵N and NUE. Restriction of N supply until V8, and from V8 to physiological maturity significantly reduced grain yield and N-uptake in all hybrids. Irrespective of the level of N-deficiency in plant and timing when the labeled fertilizer was applied, the amount of ¹⁵N recovered in the matured plant was the same in all N treatments. It has been evident that maize continued to take up N beyond 3 weeks after silking and the later N was applied during the development, the higher proportion of it was partitioned to grains. Of the total ¹⁵N uptake, 78% was partitioned to kernels in the N₄ treatment compared to only 61% in the control. Our data showed no evidence of differential N uptake, remobilization and NUE in the SG or Leafy hybrids tested, but the timing of N application and level of N-deficiency in plant significantly influenced N uptake, remobilization and N-dynamics in maize.     

Boron accumulation and partitioning in wheat cultivars with contrasting tolerance to boron deficiency

Two pot experiments at the Plant Environment Laboratory (PEL), Reading, UK investigated sterility, boron (B) accumulation and B partitioning of wheat cultivars grown with limited B in the growing medium. The first experiment evaluated nine cultivars of spring wheat with diverse field responses to low available soil B, supplied with or without 20 μM B. A second experiment examined the response of a susceptible (SW-41) and a tolerant (Fang-60) cultivar to B-deficiency. These cultivars were supplied with either 20 μM B from sowing to flag leaf emergence and no added B thereafter, or 20 μM B from sowing to maturity. When B was not supplied in the nutrient solution, the number of grains ranged from 4 per ear (cv. BL-1135) to 32 per ear (cv. BL-1249) and sterility of competent florets ranged from 39% to 93%. Boron concentration in the flag leaf at anthesis did not differ greatly when the growing medium contained limited B, but differences between cultivars were evident when B was unlimited. Tolerance of B-deficiency was not related to the B concentration in the flag leaf. Some cultivars produced viable pollen and set grains while others failed to do so at similar B concentrations in the flag leaf. The two contrasting cultivars did not differ much in their pattern of B partitioning when B supply was restricted from flag leaf emergence onwards. Similarly, little evidence was found that the tolerant cultivars translocated B from their leaves, roots or stems when the supply in the growing medium was restricted. The proportion of total B partitioned in different organs was the same irrespective of B supply and cultivar. On average, leaves contained 68% of the total B content in the whole plant compared to 16% in the roots, 10% in the ears and only 6% in the stems. Tolerant or susceptible cultivars of wheat could not be distinguished based on the B concentration and B content of the flag leaf. This revised version was published online in June 2006 with corrections to the Cover Date.     

Design and validation of a novel method to measure cross-sectional area of neck muscles included during routine MR brain volume imaging

Introduction

Low muscle mass secondary to disease and ageing is an important cause of excess mortality and morbidity. Many studies include a MR brain scan but no peripheral measure of muscle mass. We developed a technique to measure posterior neck muscle cross-sectional area (CSA) on volumetric MR brain scans enabling brain and muscle size to be measured simultaneously.

Methods

We performed four studies to develop and test: feasibility, inter-rater reliability, repeatability and external validity. We used T1-weighted MR brain imaging from young and older subjects, obtained on different scanners, and collected mid-thigh MR data.

Results

After developing the technique and demonstrating feasibility, we tested it for inter-rater reliability in 40 subjects. Intraclass correlation coefficients (ICC) between raters were 0.99 (95% confidence intervals (CI) 0.98–1.00) for the combined group (trapezius, splenius and semispinalis), 0.92 (CI 0.85–0.96) for obliquus and 0.92 (CI 0.85–0.96) for sternocleidomastoid. The first unrotated principal component explained 72.2% of total neck muscle CSA variance and correlated positively with both right (r = 0.52, p = .001) and left (r = 0.50, p = .002) grip strength. The 14 subjects in the repeatability study had had two MR brain scans on three different scanners. The ICC for between scanner variation for total neck muscle CSA was high at 0.94 (CI 0.86–0.98). The ICCs for within scanner variations were also high, with values of 0.95 (CI 0.86–0.98), 0.97 (CI 0.92–0.99) and 0.96 (CI 0.86–0.99) for the three scanners. The external validity study found a correlation coefficient for total thigh CSA and total neck CSA of 0.88.

Discussion

We present a feasible, valid and reliable method for measuring neck muscle CSA on T1-weighted MR brain scans. Larger studies are needed to validate and apply our technique with subjects differing in age, ethnicity and geographical location.     

Identification of Multiple Phosphorylation Sites on Maize Endosperm Starch Branching Enzyme IIb,a Key Enzyme in Amylopectin Biosynthesis

Starch branching enzyme IIb (SBEIIb) plays a crucial role in amylopectin biosynthesis in maize endosperm by defining the structural and functional properties of storage starch and is regulated by protein phosphorylation. Native and recombinant maize SBEIIb were used as substrates for amyloplast protein kinases to identify phosphorylation sites on the protein. A multidisciplinary approach involving bioinformatics, site-directed mutagenesis, and mass spectrometry identified three phosphorylation sites at Ser residues: Ser⁶⁴⁹, Ser²⁸⁶, and Ser²⁹⁷. Two Ca²⁺-dependent protein kinase activities were partially purified from amyloplasts, termed K1, responsible for Ser⁶⁴⁹ and Ser²⁸⁶ phosphorylation, and K2, responsible for Ser⁶⁴⁹ and Ser²⁹⁷ phosphorylation. The Ser²⁸⁶ and Ser²⁹⁷ phosphorylation sites are conserved in all plant branching enzymes and are located at opposite openings of the 8-stranded parallel β-barrel of the active site, which is involved with substrate binding and catalysis. Molecular dynamics simulation analysis indicates that phospho-Ser²⁹⁷ forms a stable salt bridge with Arg⁶⁶⁵, part of a conserved Cys-containing domain in plant branching enzymes. Ser⁶⁴⁹ conservation appears confined to the enzyme in cereals and is not universal, and is presumably associated with functions specific to seed storage. The implications of SBEIIb phosphorylation are considered in terms of the role of the enzyme and the importance of starch biosynthesis for yield and biotechnological application.