158 research outputs found
A weighted multiple classifier framework based on random projection.
In this paper, we propose a weighted multiple classifier framework based on random projections. Similar to the mechanism of other homogeneous ensemble methods, the base classifiers in our approach are obtained by a learning algorithm on different training sets generated by projecting the original up-space training set to lower dimensional down-spaces. We then apply a Least SquarE−based method to weigh the outputs of the base classifiers so that the contribution of each classifier to the final combined prediction is different. We choose Decision Tree as the learning algorithm in the proposed framework and conduct experiments on a number of real and synthetic datasets. The experimental results indicate that our framework is better than many of the benchmark algorithms, including three homogeneous ensemble methods (Bagging, RotBoost, and Random Subspace), several well-known algorithms (Decision Tree, Random Neural Network, Linear Discriminative Analysis, K Nearest Neighbor, L2-loss Linear Support Vector Machine, and Discriminative Restricted Boltzmann Machine), and random projection-based ensembles with fixed combining rules with regard to both classification error rates and F1 scores
D-Serine Is a Substrate for Neutral Amino Acid Transporters ASCT1/SLC1A4 and ASCT2/SLC1A5, and Is Transported by Both Subtypes in Rat Hippocampal Astrocyte Cultures
N-methyl-D-aspartate (NMDA) receptors play critical roles in synaptic transmission and plasticity. Activation of NMDA receptors by synaptically released L-glutamate also requires occupancy of co-agonist binding sites in the tetrameric receptor by either glycine or D-serine. Although D-serine appears to be the predominant co-agonist at synaptic NMDA receptors, the transport mechanisms involved in D-serine homeostasis in brain are poorly understood. In this work we show that the SLC1 amino acid transporter family members SLC1A4 (ASCT1) and SLC1A5 (ASCT2) mediate homo- and hetero-exchange of D-serine with physiologically relevant kinetic parameters. In addition, the selectivity profile of D-serine uptake in cultured rat hippocampal astrocytes is consistent with uptake mediated by both ASCT1 and ASCT2. Together these data suggest that SLC1A4 (ASCT1) may represent an important route of Na-dependent D-serine flux in the brain that has the ability to regulate extracellular D-serine and thereby NMDA receptor activity
Associations of Serum 25-Hydroxyvitamin D with Physical Performance and Bone Health in Overweight and Obese Older Adults
Low vitamin D status commonly accompanies obesity, and both vitamin D deficiency and obesity have been associated with falls and fracture risk in older adults. We aimed to determine the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with physical performance and bone health in community-dwelling, overweight and obese older men and women. Serum 25(OH)D concentrations were measured in 84 participants with body mass index ≥25 kg/m² (mean ± SD age 62.4 ± 7.9 years; 55% women). Physical function was determined by short physical performance battery, hand grip and quadriceps strength, and stair climb power tests. Body composition and bone structure were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. Mean ± SD 25(OH)D was 49.6 ± 17.7 nmol/L, and 50% of participants had low 25(OH)D ( 0.05). Lower 25(OH)D concentrations are associated with poorer quadricep strength and muscle power in overweight and obese older women but not men
Core-Shell Hydrogel Microcapsules for Improved Islets Encapsulation
Islets microencapsulation holds great promise to treat type 1 diabetes. Currently used alginate microcapsules often have islets protruding outside capsules, leading to inadequate immuno-protection. A novel design of microcapsules with core–shell structures using a two-fluid co-axial electro-jetting is reported. Improved encapsulation and diabetes correction is achieved in a single step by simply confining the islets in the core region of the capsules.Juvenile Diabetes Research Foundation International (grant 17-2007-1063)National Institutes of Health (U.S.) (Postdoctoral Fellowship F32 EB011580- 01)Tayebati Family Foundatio
Biology and genome of a newly discovered sibling species of Caenorhabditis elegans
A ‘sibling’ species of the model organism Caenorhabditis elegans has long been sought for use in comparative analyses that would enable deep evolutionary interpretations of biological phenomena. Here, we describe the first sibling species of C. elegans, C. inopinata n. sp., isolated from fig syconia in Okinawa, Japan. We investigate the morphology, developmental processes and behaviour of C. inopinata, which differ significantly from those of C. elegans. The 123-Mb C. inopinata genome was sequenced and assembled into six nuclear chromosomes, allowing delineation of Caenorhabditis genome evolution and revealing unique characteristics, such as highly expanded transposable elements that might have contributed to the genome evolution of C. inopinata. In addition, C. inopinata exhibits massive gene losses in chemoreceptor gene families, which could be correlated with its limited habitat area. We have developed genetic and molecular techniques for C. inopinata; thus C. inopinata provides an exciting new platform for comparative evolutionary studies
The STF2p Hydrophilin from Saccharomyces cerevisiae Is Required for Dehydration Stress Tolerance
The yeast Saccharomyces cerevisiae is able to overcome cell dehydration; cell metabolic activity is arrested during this period but restarts after rehydration. The yeast genes encoding hydrophilin proteins were characterised to determine their roles in the dehydration-resistant phenotype, and STF2p was found to be a hydrophilin that is essential for survival after the desiccation-rehydration process. Deletion of STF2 promotes the production of reactive oxygen species and apoptotic cell death during stress conditions, whereas the overexpression of STF2, whose gene product localises to the cytoplasm, results in a reduction in ROS production upon oxidative stress as the result of the antioxidant capacity of the STF2p protein
Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents
The Adapting Agriculture to Climate Change Project set out to improve the diversity,
quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and
2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed
collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we
describe the implementation of the 25 national collecting programs and present the key results. A total
of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety
duplicated in national and international genebanks, and made available through the Multilateral
System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant
Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most
collected genepools, although the greatest number of primary genepool collections were made for
rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets
were best achieved. Several of the newly collected samples have already been used in pre-breeding
programs to adapt crops to future challenges.info:eu-repo/semantics/publishedVersio
Combinatorial hydrogel library enables identification of materials that mitigate the foreign body response in primates
The foreign body response is an immune-mediated reaction that can lead to the failure of implanted medical devices and discomfort for the recipient. There is a critical need for biomaterials that overcome this key challenge in the development of medical devices. Here we use a combinatorial approach for covalent chemical modification to generate a large library of variants of one of the most widely used hydrogel biomaterials, alginate. We evaluated the materials in vivo and identified three triazole-containing analogs that substantially reduce foreign body reactions in both rodents and, for at least 6 months, in non-human primates. The distribution of the triazole modification creates a unique hydrogel surface that inhibits recognition by macrophages and fibrous deposition. In addition to the utility of the compounds reported here, our approach may enable the discovery of other materials that mitigate the foreign body response.Leona M. and Harry B. Helmsley Charitable Trust (3-SRA-2014-285-M-R)United States. National Institutes of Health (EB000244)United States. National Institutes of Health (EB000351)United States. National Institutes of Health (DE013023)United States. National Institutes of Health (CA151884)United States. National Institutes of Health (P41EB015871-27)National Cancer Institute (U.S.) (P30-CA14051
t10c12 Conjugated Linoleic Acid Suppresses HER2 Protein and Enhances Apoptosis in SKBr3 Breast Cancer Cells: Possible Role of COX2
BACKGROUND: HER2-targeted therapy with the monoclonal antibody trastuzumab (Herceptin) has improved disease-free survival for women diagnosed with HER2-positive breast cancers; however, treatment resistance and disease progression are not uncommon. Current data suggest that resistance to treatment in HER2 cancers may be a consequence of NF-kappaB overexpression and increased COX2-derived prostaglandin E2 (PGE(2)). Conjugated linoleic acid (CLA) has been shown to have anti-tumor properties and to inhibit NF-kappaB activity and COX2. METHODS: In this study, HER2-overexpressing SKBr3 breast cancer cells were treated with t10c12 CLA. Protein expression of the HER2 receptor, nuclear NF-kappaB p65, and total and phosphorylated IkappaB were examined by western blot and immunofluorescence. PGE(2) levels were determined by ELISA. Proliferation was measured by metabolism of 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), and apoptosis was measured by FITC-conjugated Annexin V staining and flow cytometry. RESULTS/CONCLUSIONS: We observed a significant decrease in HER2 protein expression on western blot following treatment with 40 and 80 microM t10c12 CLA (p<0.01 and 0.001, respectively) and loss of HER2 protein in cells using immunoflourescence that was most pronounced at 80 microM. Protein levels of nuclear NF-kappaB p65 were also significantly reduced at the 80 microM dose. This was accompanied by a significant decrease in PGE(2) levels (p = 0.05). Pretreatment with t10c12 CLA significantly enhanced TNFalpha-induced apoptosis and the anti-proliferative action of trastuzumab (p = 0.05 and 0.001, respectively). These data add to previous reports of an anti-tumor effect of t10c12 CLA and suggest an effect on the HER2 oncogene that may be through CLA mediated downregulation of COX2-derived PGE(2)
- …