713 research outputs found
Deformable image registration for geometrical evaluation of DIBH radiotherapy treatment of lung cancer patients
Evidence for Reduced Hydrogen-Bond Cooperativity in Ionic Solvation Shells from Isotope-Dependent Dielectric Relaxation
The lived experience of dysphagia following non-surgical treatment for head and neck cancer
The prevalence and severity of dysphagia in people treated non-surgically for primary head and neck cancer (HNC) is well documented. However, few studies have looked beyond the physiological impairment to explore the lived experience of dysphagia in the post-treatment period of HNC. The current study adopted a person-centred, qualitative approach to describe the experiences of people living with dysphagia in the months and years following non-surgical treatment for HNC. Using maximum variation sampling, 24 participants who had undergone radiotherapy treatment for HNC were recruited. Individual interviews were conducted to explore the impact of dysphagia on participants' everyday lives. The themes identified included: (1) physical changes related to swallowing; (2) emotions evoked by living with dysphagia; (3) altered perceptions and changes in appreciation of food; and (4) personal and lifestyle impacts. The data revealed the breadth and significance of the impact of dysphagia on the lives of people treated curatively for HNC. Assessment and management in the post-treatment period must be sufficiently holistic to address both the changing physical states and the psychosocial needs of people with dysphagia following HNC. Rehabilitation services which focus only on impairment-based management will fail to fully meet the support needs of this clinical population
Implications of flower developmental stage, plant isolation and microclimatic condition on a hemiparasitic plant–avian pollinator interaction
The pollination success of bird pollinated plants is determined by avian visits and duration of foraging which in turn have been shown to be regulated by several plant features. However, very few of these factors have been demonstrated on hemiparasitic plants under tropical African climate. This study, determined how three flower developmental stages (ripe, unripe and open flowers), plant isolation and microclimatic conditions (temperature and wind speed) influenced frequency of visits and duration of foraging by avian pollinators on the Loranthaceae mistletoe T. sessilifolius in a tropical savanna habitat in Nigeria, West Africa. One hour focal observations across 40 individuals of the study plant species was used to collect information on avian visits and duration of foraging. While numbers of flowers for the three flower developmental stages were obtained through direct counts. Results showed that increased number of closed ripe flowers on the study plant significantly attracted avian pollinators. This relationship between avian visitors and ripe flowers may be connected with the high nectar content of such flowers as reported in previous studies. Increased intensity of microclimatic factors; temperature (°C) and wind speed (m/s) however, negatively affected avian pollinators. This could be linked to their established effects of increasing avian thermoregulatory costs and mechanical inhibition of flight. These observations could potentially limit pollen deposition at stigma with consequences on plant fitness as shown in previous studies. The observations also give a picture of the potential effects of increasing temperatures in the face of global warming. Keywords: flower, avian, plant-isolation, microclimate, hemiparasitic-plant, interactio
Bat diversity and abundance in Omo Forest Reserve, Nigeria
Bats are yet to be incorporated in management plans in Nigeria. This is attributed to dearth in information as well as social stigma. This study was designed to determine bat species diversity, abundance and the relation of both indices to habitat structure. The survey was carried out in Omo forest reserve between May and June. Mist nets were deployed using stratified sampling method to place nets at 20 points. Netted points were set to be at least 200m apart. Total length of net averaged at 60 m, height ranged between 2-4m and set up after sunset from 1800-2300 hrs and before sunrise from 0400-0630 hrs. Sixty-four individuals were trapped belonging to 14 species in 8 genera and 6 families. Two other species were observed but not captured Eidolon helvum (Straw coloured fruit Bat) and Hypsignathus monstrosus (Hammer headed Fruit bat). Identification was based on Mammals of Nigeria and Mammals of Africa. Bat species diversity and bat abundance were higher in the forest compared to plantation but not significantly different. Bat species diversity decreased significantly as density of trees and litter cover increased while bat abundance decreased with increase in tree density but the relationship was not significant. Difference in diversity and abundance of bats is attributed to relative short distance between farmland and forest habitat types which provides easy access to bats for foraging. Habitat type and land usage influences the level of diversity and abundance of wildlife species for which bats are good indicators of habitat suitability.Keywords: Bats, diversity, Omo forest reserve, deforestation, density of tree
Expression Screening of Fusion Partners from an E. coli Genome for Soluble Expression of Recombinant Proteins in a Cell-Free Protein Synthesis System
While access to soluble recombinant proteins is essential for a number of proteome studies, preparation of purified functional proteins is often limited by the protein solubility. In this study, potent solubility-enhancing fusion partners were screened from the repertoire of endogenous E. coli proteins. Based on the presumed correlation between the intracellular abundance and folding efficiency of proteins, PCR-amplified ORFs of a series of highly abundant E. coli proteins were fused with aggregation-prone heterologous proteins and then directly expressed for quantitative estimation of the expression efficiency of soluble translation products. Through two-step screening procedures involving the expression of 552 fusion constructs targeted against a series of cytokine proteins, we were able to discover a number of endogenous E. coli proteins that dramatically enhanced the soluble expression of the target proteins. This strategy of cell-free expression screening can be extended to quantitative, global analysis of genomic resources for various purposes.National Research Foundation of KoreaKorea (South). Ministry of Education, Science and Technology (MEST) (grant 2011K000841)Korea (South). Ministry of Education, Science and Technology (MEST) (grant 2011-0027901
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Fecal microbiota and bile acid interactions with systemic and adipose tissue metabolism in diet-induced weight loss of obese postmenopausal women
Microbiota and bile acids in the gastrointestinal tract profoundly alter systemic metabolic processes. In obese subjects, gradual weight loss ameliorates adipose tissue inflammation and related systemic changes. We assessed how rapid weight loss due to a very low calorie diet (VLCD) affects the fecal microbiome and fecal bile acid composition, and their interactions with the plasma metabolome and subcutaneous adipose tissue inflammation in obesity. We performed a prospective cohort study of VLCD-induced weight loss of 10% in ten grades 2-3 obese postmenopausal women in a metabolic unit. Baseline and post weight loss evaluation included fasting plasma analyzed by mass spectrometry, adipose tissue transcription by RNA sequencing, stool 16S rRNA sequencing for fecal microbiota, fecal bile acids by mass spectrometry, and urinary metabolic phenotyping by H-NMR spectroscopy. Outcome measures included mixed model correlations between changes in fecal microbiota and bile acid composition with changes in plasma metabolite and adipose tissue gene expression pathways. Alterations in the urinary metabolic phenotype following VLCD-induced weight loss were consistent with starvation ketosis, protein sparing, and disruptions to the functional status of the gut microbiota. We show that the core microbiome was preserved during VLCD-induced weight loss, but with changes in several groups of bacterial taxa with functional implications. UniFrac analysis showed overall parallel shifts in community structure, corresponding to reduced abundance of the genus Roseburia and increased Christensenellaceae;g__ (unknown genus). Imputed microbial functions showed changes in fat and carbohydrate metabolism. A significant fall in fecal total bile acid concentration and reduced deconjugation and 7-α-dihydroxylation were accompanied by significant changes in several bacterial taxa. Individual bile acids in feces correlated with amino acid, purine, and lipid metabolic pathways in plasma. Furthermore, several fecal bile acids and bacterial species correlated with altered gene expression pathways in adipose tissue. VLCD dietary intervention in obese women changed the composition of several fecal microbial populations while preserving the core fecal microbiome. Changes in individual microbial taxa and their functions correlated with variations in the plasma metabolome, fecal bile acid composition, and adipose tissue transcriptome
ORCHIDEE-PEAT (revision 4596), a model for northern peatland CO2, water, and energy fluxes on daily to annual scales
Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5 degrees grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC) observations from 30 northern peatland sites, with the maximum rate of carboxylation (V-cmax) being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP) (r(2) = 0.76; Nash-Sutcliffe modeling efficiency, MEF = 0.76) and ecosystem respiration (ER, r(2) = 0.78, MEF = 0.75), with lesser accuracy for latent heat fluxes (LE, r(2) = 0.42, MEF = 0.14) and and net ecosystem CO2 exchange (NEE, r(2) = 0.38, MEF = 0.26). Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r(2) values (0.57-0.86). For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r(2) values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT) variation was not well predicted (r(2) <0.1), likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized V-cmax and latitude (temperature), which better reflects the spatial gradients of annual NEE than using an average V-cmax value.Peer reviewe
Temperature evolution of structural and magnetic properties of stoichiometric LiCu2O2: correlation of thermal expansion coefficient and magnetic order
Temperature-dependent crystallographic and magnetic studies on stoichiometric
single crystals of LiCu2O2 are reported. The magnetic properties are similar to
earlier findings demonstrating antiferromagnetic ordering below 25 K. Evidence
of magnetoelastic coupling is observed in the thermal expansion along the
c-direction; not only at the low temperature antiferromagnetic transitions, but
an anomalous behavior of the thermal expansion indicate magnetoelastic coupling
also to the magnetic ordering related to a weak spontaneous magnetic moment
appearing at 150 K. Ac-susceptibility measurements at different frequencies and
superposed dc- fields are employed to further characterize this magnetic
anomaly.Comment: 12 pages, 5 figure
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