603 research outputs found
Managing water conflicts through dialogue in Pangani Basin, Tanzania
River basinsWater resource managementConflictWater users
A Toxic Metabolite Produced by Diaporthe Phaseolorum Var. Caulivora, the Causal Organism of Stem Canker of Soybean.
The role of a toxic metabolite in the stem canker disease of soybean was investigated. Isolates of Dpc produced a metabolite in the culture filtrate which produced symptoms similar to stem canker on soybean plants. The severity of symptoms was dose dependent. The isolate from Opelousas, Louisiana produced significantly higher amounts of the toxin than the other isolates. A positive correlation was seen between the amount of toxin produced and the severity of disease produced by the Dpc isolates. Among twelve plant species tested, only soybean and lima bean, were sensitive to the toxin. Reaction of five soybean cultivars to the culture filtrates of the Dpc isolates did not reflect the resistance of the cultivars to the pathogen as seen in the field. Spectral analyses indicated that the toxic metabolite is a low molecular weight aromatic compound, has one or more hydroxyl groups, methyl groups and C=C, and has a reducing nature. The trifoliates were not sensitive to cytochalasins H and B, but were sensitive to a toxic metabolite produced by a Phomopsis sp. isolated from wilted pine trees. Some of the chemical properties of Dpc toxin are similar to the Phomopsis/pine wilt toxin. Preliminary studies indicated a similar molecular ion peak of the two toxins. The initial symptom of toxin action was a red discoloration of midrib and veins before chlorosis was observed. The toxin induced yellow autofluorescence of vascular bundles. The fluorescence was also associated with lesions on the plant parts. The discoloration of the midrib and veins, and lesions on the plant were due to accumulation of phenols which are alkali soluble, can be extracted and separated by thin layer chromatography, and react with Folin-Ciocalteu reagent and ferric chloride. Two phenolic compounds, and a compound showing yellow fluorescence, not seen in untreated samples were observed in the toxin treated and fungus inoculated samples suggesting a common host response to toxin action and fungal inoculation. The role of toxin in the stem canker disease appears to be as a virulence factor
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Mapping individual brains to guide restorative therapy after stroke: rationale and pilot studies.
Some treatments under development to improve motor outcome after stroke require information about organization of individual subject's brain. The current study aimed to characterize normal inter-subject differences in localization of motor functions, and to consider these findings in relation to a potential treatment of motor deficits after stroke. Functional MRI (fMRI) scanning in 14 subjects examined right index finger tapping, shoulder rotation, or facial movement. The largest activation cluster in left sensorimotor cortex was identified for each task, and its center expressed in Talairach stereotaxic coordinates. Across subjects, each task showed considerable variability in activation site coordinates. For example, during finger tapping, the range for center of activation was 7 mm in the x-axis, 19 mm in the y-axis, and 11 mm in the z-axis. The mean value for center of activation was significantly different for all three coordinates for all pairwise task comparisons. However, the distribution of activation site centers for the finger task overlapped with the other two tasks in the x- and y-axes, and with the shoulder task in the z-axis. On average, the center of activation for the three motor tasks were spatially separated and somatotopically distributed. However, across the population, there was considerable overlap in the center of activation site, especially for finger and shoulder movements. Restorative therapies that aim to target specific body segments, such as the hand, in the post-stroke motor system may need to map the individual brain rather than rely on population averages. Initial details are presented of a study using this approach to evaluate such a therapy
Oxidative Stress Conditions Result in Trapping of PHF-Core Tau (297â391) Intermediates
Funding: This work was supported by funding from Alzheimerâs Society [345 (AS-PG-16b-010)] awarded to L.C.S. and funding M.B.M. Y.K.A.-H. is supported by WisTa Laboratories Ltd. (PAR1596). The work was supported by ARUK South Coast Network. G.B. was supported by European Molecular Biology Organisation (EMBO) Short-Term Fellowship award (EMBO-STF 7674). LCS is supported by BBSRC [BB/S003657/1]. Acknowledgments: TEM work was performed at the University of Sussexâs Electron microscopy imaging centre (EMC), funded by the School of Life Sciences, the Wellcome Trust (095605/Z/11/A, 208348/Z/17/Z) and the RM Phillips Trust. The authors thank Pascale Schellenberger for valuable support.Peer reviewedPublisher PD
Universality of Level Spacing Distributions in Classical Chaos
We suggest that random matrix theory applied to a classical action matrix can
be used in classical physics to distinguish chaotic from non-chaotic behavior.
We consider the 2-D stadium billiard system as well as the 2-D anharmonic and
harmonic oscillator. By unfolding of the spectrum of such matrix we compute the
level spacing distribution, the spectral auto-correlation and spectral
rigidity. We observe Poissonian behavior in the integrable case and Wignerian
behavior in the chaotic case. We present numerical evidence that the action
matrix of the stadium billiard displays GOE behavior and give an explanation
for it. The findings present evidence for universality of level fluctuations -
known from quantum chaos - also to hold in classical physics
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Use of functional MRI to guide decisions in a clinical stroke trial.
Background and purposeAn investigational trial examined safety and efficacy of targeted subthreshold cortical stimulation in patients with chronic stroke. The anatomical location for the target, hand motor area, varies across subjects, and so was localized with functional MRI (fMRI). This report describes the experience of incorporating standardized fMRI into a multisite stroke trial.MethodsAt 3 enrollment centers, patients moved (0.25 Hz) the affected hand during fMRI. Hand motor function was localized at a fourth center guiding intervention for those randomized to stimulation.ResultsThe fMRI results were available within 24 hours. Across 12 patients, activation site variability was substantial (12, 23, and 11 mm in x, y, and z directions), exceeding stimulating electrode dimensions.ConclusionsUse of fMRI to guide decision-making in a clinical stroke trial is feasible
Management of infections pre- and post-liver transplantation: Report of an AISF consensus conference
The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre- as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns
Umbilical cord mesenchymal stem cells modulate dextran sulphate sodium induced acute colitis in immunodeficient mice.
Inflammatory bowel diseases (IBD) are complex multi-factorial diseases with increasing incidence worldwide but their treatment is far from satisfactory. Unconventional strategies have consequently been investigated, proposing the use of stem cells as an effective alternative approach to IBD. In the present study we examined the protective potential of exogenously administered human umbilical cord derived mesenchymal stem cells (UCMSCs) against Dextran Sulphate Sodium (DSS) induced acute colitis in immunodeficient NOD.CB17-Prkdc scid/J mice with particular attention to endoplasmic reticulum (ER) stress.
METHODS:
UCMSCs were injected in NOD.CB17-Prkdc scid/J via the tail vein at day 1 and 4 after DSS administration. To verify attenuation of DSS induced damage by UCMSCs, Disease Activity Index (DAI) and body weight changes was monitored daily. Moreover, colon length, histological changes, myeloperoxidase and catalase activities, metalloproteinase (MMP) 2 and 9 expression and endoplasmic reticulum (ER) stress related proteins were evaluated on day 7.
RESULTS:
UCMSCs administration to immunodeficient NOD.CB17-Prkdc scid/J mice after DSS damage significantly reduced DAI (1.45\u2009\ub1\u20090.16 vs 2.08\u2009\ub1\u20090.18, p\u20093-fold), which were significantly reduced in mice receiving UCMSCs. Moreover, positive modulation in ER stress related proteins was observed after UCMSC administration.
CONCLUSIONS:
Our results demonstrated that UCMSCs are able to prevent DSS-induced colitis in immunodeficient mice. Using these mice we demonstrated that our UCMSCs have a direct preventive effect other than the T-cell immunomodulatory properties which are already known. Moreover we demonstrated a key function of MMPs and ER stress in the establishment of colitis suggesting them to be potential therapeutic targets in IBD treatment
Recent advances in alcohol-related liver disease (ALD): summary of a Gut roundtable meeting
Alcohol-related liver disease (ALD), which includes a range of disorders of different severity and is
one of the most prevalent types of liver disease worldwide, has recently regained increased
attention. Among other reasons, the realisation that any alcohol intake, regardless of type of
beverage represents a health risk, and the new therapeutic strategies tested in recently published or
undergoing clinical trials spur scientific interest in this area.
In April 2019, Gut convened a round table panel of experts during the European Association for the
Study of the Liver (EASL) International Liver Congress (ILC) in Vienna to discuss critical and up-to-date
issues and clinical trial data regarding ALD, its epidemiology, diagnosis, management,
pathomechanisms, possible future treatments and prevention. This paper summarises the discussion
and its conclusions
Quantifying geocode location error using GIS methods
BACKGROUND: The Metropolitan Atlanta Congenital Defects Program (MACDP) collects maternal address information at the time of delivery for infants and fetuses with birth defects. These addresses have been geocoded by two independent agencies: (1) the Georgia Division of Public Health Office of Health Information and Policy (OHIP) and (2) a commercial vendor. Geographic information system (GIS) methods were used to quantify uncertainty in the two sets of geocodes using orthoimagery and tax parcel datasets. METHODS: We sampled 599 infants and fetuses with birth defects delivered during 1994â2002 with maternal residence in either Fulton or Gwinnett County. Tax parcel datasets were obtained from the tax assessor's offices of Fulton and Gwinnett County. High-resolution orthoimagery for these counties was acquired from the U.S. Geological Survey. For each of the 599 addresses we attempted to locate the tax parcel corresponding to the maternal address. If the tax parcel was identified the distance and the angle between the geocode and the residence were calculated. We used simulated data to characterize the impact of geocode location error. In each county 5,000 geocodes were generated and assigned their corresponding Census 2000 tract. Each geocode was then displaced at a random angle by a random distance drawn from the distribution of observed geocode location errors. The census tract of the displaced geocode was determined. We repeated this process 5,000 times and report the percentage of geocodes that resolved into incorrect census tracts. RESULTS: Median location error was less than 100 meters for both OHIP and commercial vendor geocodes; the distribution of angles appeared uniform. Median location error was approximately 35% larger in Gwinnett (a suburban county) relative to Fulton (a county with urban and suburban areas). Location error occasionally caused the simulated geocodes to be displaced into incorrect census tracts; the median percentage of geocodes resolving into incorrect census tracts ranged between 4.5% and 5.3%, depending upon the county and geocoding agency. CONCLUSION: Geocode location uncertainty can be estimated using tax parcel databases in a GIS. This approach is a viable alternative to global positioning system field validation of geocodes
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