1,670 research outputs found
LTER IMC community of practice: a learning environment
The SGS-LTER research site was established in 1980 by researchers at Colorado State University as part of a network of long-term research sites within the US LTER Network, supported by the National Science Foundation. Scientists within the Natural Resource Ecology Lab, Department of Forest and Rangeland Stewardship, Department of Soil and Crop Sciences, and Biology Department at CSU, California State Fullerton, USDA Agricultural Research Service, University of Northern Colorado, and the University of Wyoming, among others, have contributed to our understanding of the structure and functions of the shortgrass steppe and other diverse ecosystems across the network while maintaining a common mission and sharing expertise, data and infrastructure.Includes bibliographical references.Communities of practice are groups of people who share a concern or a passion for something they do and learn how to do it better as they interact regularly. A community of practice is not merely a group of people having the same job or a network of connections between people
Governor’s Task Force on the Planning and Development of Marine Aquaculture in Maine - Executive Summary of Final Report
Astronom
The rkpU gene of Sinorhizobium fredii HH103 is required for bacterial K-antigen polysaccharide production and for efficient nodulation with soybean but not with cowpea
In this work, the role of the rkpU and rkpJ genes in the production of the K-antigen
polysaccharides (KPS) and in the symbiotic capacity of Sinorhizobium fredii HH103, a broad
host-range rhizobial strain able to nodulate soybean and many other legumes, was studied. The
rkpJ- and rkpU-encoded products are orthologous to Escherichia coli proteins involved in
capsule export. S. fredii HH103 mutant derivatives were contructed in both genes. To our
knowledge, this is the first time that the role of rkpU in KPS production has been studied in
rhizobia. Both rkpJ and rkpU mutants were unable to produce KPS. The rkpU derivative also
showed alterations in its lipopolysaccharide (LPS). Neither KPS production nor rkpJ and rkpU
expression was affected by the presence of the flavonoid genistein. Soybean (Glycine max) plants
inoculated with the S. fredii HH103 rkpU and rkpJ mutants showed reduced nodulation and clear
symptoms of nitrogen starvation. However, neither the rkpJ nor the rkpU mutants were
significantly impaired in their symbiotic interaction with cowpea (Vigna unguiculata). Thus, we
demonstrate for the first time to our knowledge the involvement of the rkpU gene in rhizobial KPS
production and also show that the symbiotic relevance of the S. fredii HH103 KPS depends on
the specific bacterium–legume interaction
Recommended from our members
Imaging Cyclotron Orbits of Electrons in Graphene
Electrons in graphene can travel for several microns without scattering at low temperatures, and their motion becomes ballistic, following classical trajectories. When a magnetic field B is applied perpendicular to the plane, electrons follow cyclotron orbits. Magnetic focusing occurs when electrons injected from one narrow contact focus onto a second contact located an integer number of cyclotron diameters away. By tuning the magnetic field B and electron density n in the graphene layer, we observe magnetic focusing peaks. We use a cooled scanning gate microscope to image cyclotron trajectories in graphene at 4.2 K. The tip creates a local change in density that casts a shadow by deflecting electrons flowing nearby; an image of flow can be obtained by measuring the transmission between contacts as the tip is raster scanned across the sample. On the first magnetic focusing peak, we image a cyclotron orbit that extends from one contact to the other. In addition, we study the geometry of orbits deflected into the second point contact by the tip.Physic
Outcomes of adjunctive radiation therapy for the treatment of mast cell tumors in dogs and assessment of toxicity: A multicenter observational study of 300 dogs.
BACKGROUND: Radiation therapy is commonly used as an adjunct to incomplete surgical excision in dogs with mast cell tumors (MCT), but the optimal dose and fractionation regimen have yet to be determined. HYPOTHESIS: We assessed outcomes (time to local recurrence, patient survival and toxicity) of a large population of dogs with MCT that received adjunctive radiation therapy. ANIMALS: Three hundred dogs with 302 MCT treated using adjunctive radiation therapy. METHODS: Retrospective observational study. Clinical records of 4 veterinary radiation centers were reviewed. RESULTS: Local recurrence rates were similar regardless of radiation protocol with 6.6% of patients developing recurrent cutaneous MCT at a median of 526 days. Local recurrence rate was similar between high and low-risk MCT. Mast cell tumor related death was reported in 19% of all dogs, with 13% of dogs with low-risk MCT dying of their disease compared to 29% of dogs with high-risk MCT. No SC MCT (SCMCT) recurred after radiation therapy and only 7% of dogs with SCMCT were reported to have died of their disease. Mild late toxicity was common in both protocols and severe late toxicity occurred in 1.9% of dogs many years after treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Our study supports the use of adjunctive radiation for the long-term control of incompletely or narrowly excised cutaneous and SCMCT in dogs. More moderate dose and fractionation protocols may be appropriate in the adjunctive treatment of low-risk MCT in dogs. Large multicenter prospective studies are required to establish the optimal dose and fractionation for MCT of different risk categories
Recommended from our members
ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries.
This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors
Salud mental y democracia participativa en Colombia periodo 2010 – 2014
Tesis¿Por qué hablar de salud mental y democracia en Colombia? Realmente fue la pregunta inicial por la cual se dio el inicio a esta investigación, tratando de entender la enredada realidad por la cual se ha venido materializando el sujeto como actor político en un ecosistema complejo y distorsionado. Por ejemplo, según el plan Decenal de Salud Pública 2012 – 2021, planteó una reforma al Sistema General de Seguridad Social en Salud del país, que, mediante la conocida ley 1438 del 2011 (ley que fue sancionada en el periodo de observación de la presente investigación), buscó promover mecanismos de participación colectiva e individual, orientada hacia la Atención Primaria en Salud, buscando tener una marca importante en los determinantes sociales y económicos de la salud dentro del territorio colombiano. Para esta investigación, se utilizó un enfoque de corte cualitativo exploratoria, con un diseño hermeneútico. De igual forma, se utilizó el muestreo por expertos.1. LINEAMIENTOS GENERALES DE LA INVESTIGACIÓN
2. SALUD MENTAL
3. DEMOCRACIA
4. MÉTODO
5. RESULTADOS Y DISCUSIÓN
6. CONCLUSIONES
7. RECOMENDACIONES
8. REFERENCIASMaestríaMagister en Ciencia Polític
Purification of antibodies to O antigen of Salmonella Typhimurium from human serum by affinity chromatography
AbstractNontyphoidal Salmonellae (NTS) are a common cause of bacteraemia in children and HIV-infected adults in Sub-Saharan Africa. We have previously shown that antibodies play a key role in both bactericidal and cellular mechanisms of immunity to NTS, but found that high concentrations of antibody to Salmonella Typhimurium O antigen (OAg) in the serum of some HIV-infected African adults is associated with impaired killing of NTS. To further investigate the function of antibodies to the OAg of NTS, we developed a method to purify these antibodies from human serum by affinity chromatography. Purified Salmonella Typhimurium OAg was activated with adipic acid dihydrazide (ADH) via two different chemistries before linking to N-hydroxysuccinamide-Sepharose resin: one ADH molecule was introduced per OAg chain on its terminal 3-deoxy-D-manno-octulosonic acid sugar (OAg–ADH), or multiple ADH molecules were attached along the OAg chain after oxidation with sodium periodate (OAgoxADH). Both resulting columns worked well when tested with commercial polyclonal anti-O:4,5 antibodies from rabbit serum. Over 90% of the applied antibodies bound to the resin and 89% of these antibodies were then eluted as detected by ELISA. OAg–ADH was preferred as the method for OAg derivatisation as it does not modify the saccharide chain and can be applied to OAg from different bacteria. Both columns were able to bind OAg-specific antibodies in human serum, but antibody recovery was initially low. Different elution buffers were tested and different amounts of OAg–ADH were linked to the resin to improve the yield. Optimal recovery (51%) was obtained by loading 1mg of activated OAg per ml of resin and eluting with 0.1M glycine, 0.1M NaCl pH2.4. The column matrix could be regenerated following elution with no detectable loss in performance for over ten uses. This method offers the potential to purify antibodies to Salmonella OAg from polyclonal serum following vaccination or natural exposure to Salmonella and so investigate the functionality and diversity of the antibody response to OAg
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis
- …