3,033 research outputs found
An Alternative Proof of Hesselholt's Conjecture on Galois Cohomology of Witt Vectors of Algebraic Integers
Let be a complete discrete valuation field of characteristic zero with
residue field of characteristic . Let be a finite Galois
extension with Galois group G=\Gal(L/K) and suppose that the induced
extension of residue fields is separable. Let
denote the ring of -typical Witt vectors of length . Hesselholt
conjectured that the pro-abelian group
is isomorphic to zero.
Hogadi and Pisolkar have recently provided a proof of this conjecture. In this
paper, we provide an alternative proof of Hesselholt's conjecture which is
simpler in several respects.Comment: 3 pages; added references, changed Remark 2.1 to a lemma and proof,
updated abstrac
ATD-2 Integrated Arrival/Departure/Surface (IADS) System Specification - Phase 2
The purpose of this document is to capture the core capabilities developed in ATD-2 Phase 2
Root architecture of provenances, seedlings and cuttings of Melia volkensii: implications for crop yield in dryland agroforestry
Melia volkensii (Gürke) is being increasingly promoted as an on-farm tree in Kenya. Researchers’ and farmers’ views on its competitiveness with crops differ; research station studies have found it to be highly competitive whereas farmers do not consider it to be so. Because of difficulties in seed germination, it is probable that dissemination programmes will rely upon plants produced from root and stem cuttings, rather than on seedlings. This study evaluates differences in root system architecture of plants raised from seed (of four provenances), stem or root cuttings and the relationships between the competitivity index (CI) and crop yield. Cuttings were more shallowly rooting than seedlings, and had higher competitivity indices, and there was a negative relationship between CI and crop yield. No differences in root architecture between provenances were found. Therefore, to reduce tree-crop competition, the use of seedlings rather than cuttings should be recommended when promoting the use of this species on dryland farms. If cuttings are used to circumvent the problems of seed germination, alternative methods of controlling competition, such as root pruning, need to be considered
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The Veterans Affairs Neuropathy Scale: A Reliable, Remote Polyneuropathy Exam.
Introduction: Polyneuropathy (PN) complaints are common, prompting many referrals for neurologic evaluation. To improve access of PN care in distant community clinics, we developed a telemedicine service (patient-clinician interactions using real-time videoconference technology) for PN. The primary goal of this study was to construct a remote exam for PN that is feasible, reliable, and concordant with in-person assessments for use in our tele-PN clinics. Methods: To construct the VA Neuropathy Scale (VANS), we searched the literature for existing, validated PN assessments. From these assessments, we selected a parsimonious set of exam elements based on literature-reported sensitivity and specificity of PN detection, with modifications as necessary for our teleneurology setting (i.e., a technician examination under the direction of a neurologist). We recruited 28 participants with varying degrees of PN to undergo VANS testing under 5 scenarios. The 5 scenarios differed by mode of VANS grading (in-person vs. telemedicine) and by the in-person examiner type (neurologist vs. technician) in telemedicine scenarios. We analyzed concordance between the VANS and a person's medical chart-derived PN status by modeling the receiver operating characteristic (ROC) curve. We analyzed reliability of the VANS by mixed effects regression and computing the intraclass correlation coefficient (ICC) of scores across the 5 scenarios. Results: The VA Neuropathy Scale (VANS) tests balance, gait, reflexes, foot inspection, vibration, and pinprick. Possible scores range from 0 to 50 (worst). From the ROC curve, a cutoff of >2 points on the VANS sets the sensitivity and specificity of detecting PN at 98 and 91%, respectively. There is a small (1.3 points) but statistically significant difference in VANS scoring between in-person and telemedicine grading scenarios. For telemedicine grading scenarios, there is no difference in VANS scores between neurologist and technician examinations. The ICC is 0.89 across all scenarios. Discussion: The VANS, informed by existing PN instruments, is a promising clinical assessment tool for diagnosing and monitoring the severity of PN in telemedicine settings. This pilot study indicates acceptable concordance and reliability of the VANS with in-person examinations
Tree growth and management in Ugandan agroforestry systems: effects of root pruning on tree growth and crop yield
Tree root pruning is a potential tool for managing below-ground competition when trees and crops are grown together in agroforestry systems. This study investigates its effects on growth and root distribution of Alnus acuminata (HB & K), Casuarina equisetifolia (L), Grevillea robusta (A. Cunn. ex R. Br), Maesopsis eminii (Engl.), and Markhamia lutea (Benth.) K. Schum. and on yield of adjacent crops in sub-humid Uganda. The trees were 3 years old at the commencement of the study, and most species were competing strongly with crops. Tree roots were pruned 41 months after planting by cutting and back-filling a trench to a depth of 0.3 m, at a distance of 0.3 m from the trees, on one side of the tree row. The trench was re-opened and roots re-cut at 50 and 62 months after planting. Effects on tree growth and root distribution were assessed over a 3 year period, and crop yield after the third root pruning at 62 months is reported here. Overall, root pruning had only a slight effect on tree growth: height growth was unaffected and diameter growth was reduced by only 4 %. A substantial amount of root re-growth was observed by 11 months after pruning. Tree species varied in the number and distribution of their roots, and Casuarina and Markhamia had considerably more roots per unit of trunk volume than the other tree species, especially in the surface soil layers. Casuarina and Maesopsis were the most competitive tree species with crops and Grevillea and Markhamia the least. Crop yield data provides strong evidence of the redistribution of root activity following root pruning, so that competition increased on the unpruned side of tree rows. Thus, one-sided root pruning will only be of use to farmers in a few circumstances.
Key words: Alnus acuminata, Casuarina equisetifolia, Grevillea robusta, Maesopsis eminii, Markhamia lutea, root distribution, root functio
Optimization of Agrobacterium-Mediated Transformation Parameters for Melastomatacea Spp. Using Green Fluorescent Protein(GFP) as A Reporter
Agrobacterium-mediated transformation for both Melastoma malabathricum and Tibouchinu semidecanda were optimized using green fluorescent protein (GFP) as a reporter. The binary vector pCAMBIA1304 harboring the modified green fluorescent protein (mgfp) gene driven by the CuMV 35S promoter was used. Parameters optimized were bacterial strain, bacterial concentration, pre-culture period, co-cultivation period,immersion time, acetosyring concentration and wounding type. Results obtained obtained were based on the percentage of (GFP expression which was observed 3 days post-transformation. Agrobacterium tumefaciens starin LBA4404 and EHA105 at concentration 1 X 107 cfu ml -1 (OD 600mm 0.8) showed the highest virulence on M. malabathricum and T.semidecandra, respectively. Four days of pre-culture and 2 days of co-cultivation were optimum for M.malabathricum transformation, while 3 days of pre-culture and co-cultivation fot T, semidecandra, . result also showed that 60 min of immersion and addition of 200 p.M acetosyringone gave the highest percentage of positive transformants for both M. malabathricum and T.semidecandra. Mild wounding also significantly increased the efficiency 0f M.malabathricum transformation
Agrobacterium-mediated transformation of melastoma malabathricum and tibouchina semidecandra with sense and antisense dihydroflavonol-4-reductase(DFR)genes.
Genetic engineering of a wide variety of plant species has led to the improvement of plant traits. In this study, the genetic transformation of two potentially important flowering ornamentals, Melastoma malabathricum and Tibouchina semidecandra, with sense and antisense dihydroflavonol-4-reductase (DFR) genes using the
Agrobacterium mediated method was carried out. Plasmids pBETD10 and pBETD11, each harbouring the DFR gene at different orientations (sense and antisense) and selectable marker npt II for kanamycin resistance, were used to transform M. malabathricum and T. semidecandra under the optimized transformation protocol. Putative transformants were selected in the presence of kanamycin with their respective optimized concentration. The results indicated that approximately 4.0% of shoots and 6.7% of nodes for
M. malabathricum regenerated after transforming with pBETD10, whereas only 3.7% (shoots) and 5.3%(nodes) regenerated with pBETD11 transformation. For the selection of T. semidecandra, 5.3% of shoots and 9.3% of nodes regenerated with pBETD10 transformation, while only 4.7% (shoots) and 8.3% (nodes) regenerated after being transformed with pBETD11. The presence and integration of the sense and antisense DFR genes into the genome of
M. malabathricum and T. semidecandra were verified by polymerase chain reaction (PCR) and nucleotide sequence alignment and confirmed by southern analysis. The regenerated putative transformants were acclimatized to glasshouse conditions. Approximately 31.0% pBETD10-ransformed and 23.1% pBETD11-transformed M. malabathricum
survived in the glasshouse, whereas 69.4% pBETD10-transformed and 57.4% pBETD11-transformed T. semidecandra
survived. The colour changes caused by transformation were observed at the budding stage of putative T. semidecandra
transformants where greenish buds were produced by both
T. semidecandra harbouring the sense and antisense DFR
transgenes. Besides that, the production of four-petal
flowers also indicated another morphological difference of
putative T. semidecandra transformants from the wild type
plants which produce five-petal flowers
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Teleneurology clinics for polyneuropathy: a pilot study.
INTRODUCTION:Polyneuropathy (PN) is a common condition with significant morbidity. We developed tele-polyneuropathy (tele-PN) clinics to improve access to neurology and increase guideline-concordant PN care. This article describes the mixed-methods evaluation of pilot tele-PN clinics at three community sites within the Greater Los Angeles VA Healthcare System. METHODS:For the first 25 patients (48 scheduled visits), we recorded the duration of the tele-PN visit and exam; the performance on three guideline-concordant care indicators (PN screening labs, opiate reduction, physical therapy for falls); and patient-satisfaction scores. We elicited comments about the tele-PN clinic from patients and the clinical team. We combined descriptive statistics with qualitative themes to determine the feasibility and acceptability of the tele-PN clinics. RESULTS:The average tele-PN encounter and exam times were 28.5 and 9.1 min, respectively. PN screening lab completion increased from 80 to 100%. Opiate freedom improved from 68 to 88%. Physical therapy for patients with recent falls increased from 58 to 100%. The tele-PN clinic was preferred for follow-up over in-person clinics in 86% of cases. Convenience was paramount to the clinic's success, saving an average of 231 min per patient in round-trip travel. The medical team's caring and collaborative spirit received high praise. While the clinic's efficiency was equal or superior to in-person care, the limited treatment options for PN and the small clinical exam space are areas for improvement. CONCLUSION:In this pilot, we were able to efficiently see and examine patients remotely, promote guideline-concordant PN care, and provide a high-satisfaction encounter
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