96 research outputs found
Lateral Ordering of InAs Quantum Dots on Cross-hatch Patterned GaInP
We report the use of partially relaxed tensile as well as compressively strained GaInP layers for lateral ordering of InAs quantum dots with the aid of misfit dislocation networks. The strained layers and the InAs QDs were characterized by means of atomic force microscopy, scanning electron microscopy, and X-ray reciprocal space mapping. The QD-ordering properties of compressive GaInP are found to be very similar with respect to the use of compressive GaInAs, while a significantly stronger ordering of QDs was observed on tensile GaInP. Furthermore, we observed a change of the major type of dislocation in GaInP layers as the growth temperature was modified
Extensive neuroadaptive changes in cortical gene-transcript expressions of the glutamate system in response to repeated intermittent MDMA administration in adolescent rats
<p>Abstract</p> <p>Background</p> <p>Many studies have focused on the implication of the serotonin and dopamine systems in neuroadaptive responses to the recreational drug 3,4-methylenedioxy-metamphetamine (MDMA). Less attention has been given to the major excitatory neurotransmitter glutamate known to be implicated in schizophrenia and drug addiction. The aim of the present study was to investigate the effect of repeated intermittent MDMA administration upon gene-transcript expression of the glutamate transporters (EAAT1, EAAT2-1, EAAT2-2), the glutamate receptor subunits of AMPA (GluR1, GluR2, GluR3), the glutamate receptor subunits of NMDA (NR1, NR2A and NR2B), as well as metabotropic glutamate receptors (mGluR1, mGluR2, mGluR3, mGluR5) in six different brain regions. Adolescent male Sprague Dawley rats received MDMA at the doses of 3 Ă 1 and 3 Ă 5 mg/kg/day, or 3Ă vehicle 3 hours apart, every 7<sup>th </sup>day for 4 weeks. The gene-transcript levels were assessed using real-time PCR validated with a range of housekeeping genes.</p> <p>Results</p> <p>The findings showed pronounced enhancements in gene-transcript expression of GluR2, mGluR1, mGluR5, NR1, NR2A, NR2B, EAAT1, and EAAT2-2 in the cortex at bregma +1.6. In the caudate putamen, mRNA levels of GluR3, NR2A, and NR2B receptor subunits were significantly increased. In contrast, the gene-transcript expression of GluR1 was reduced in the hippocampus. In the hypothalamus, there was a significant increase of GluR1, GluR3, mGluR1, and mGluR3 gene-transcript expressions.</p> <p>Conclusion</p> <p>Repeated intermittent MDMA administration induces neuroadaptive changes in gene-transcript expressions of glutamatergic NMDA and AMPA receptor subunits, metabotropic receptors and transporters in regions of the brain regulating reward-related associative learning, cognition, and memory and neuro-endocrine functions.</p
Solar System Abundances of the Elements
Representative abundances of the chemical elements for use as a solar
abundance standard in astronomical and planetary studies are summarized.
Updated abundance tables for solar system abundances based on meteorites and
photospheric measurements are presented.Comment: 46 pages; 5 figures; 8 tables; In: Principles and Perspectives in
Cosmochemistry.Lecture Notes of the Kodai School on 'Synthesis of Elements in
Stars' held at Kodaikanal Observatory, India, April 29 - May 13, 2008 (Aruna
Goswami and B. Eswar Reddy eds.) Astrophysics and Space Science Proceedings,
Springer-Verlag Berlin Heidelberg, 2010, p. 379-417 (ISBN 978-3-642-10351-3),
201
Microbial Co-occurrence Relationships in the Human Microbiome
The healthy microbiota show remarkable variability within and among individuals. In addition to external exposures, ecological relationships (both oppositional and symbiotic) between microbial inhabitants are important contributors to this variation. It is thus of interest to assess what relationships might exist among microbes and determine their underlying reasons. The initial Human Microbiome Project (HMP) cohort, comprising 239 individuals and 18 different microbial habitats, provides an unprecedented resource to detect, catalog, and analyze such relationships. Here, we applied an ensemble method based on multiple similarity measures in combination with generalized boosted linear models (GBLMs) to taxonomic marker (16S rRNA gene) profiles of this cohort, resulting in a global network of 3,005 significant co-occurrence and co-exclusion relationships between 197 clades occurring throughout the human microbiome. This network revealed strong niche specialization, with most microbial associations occurring within body sites and a number of accompanying inter-body site relationships. Microbial communities within the oropharynx grouped into three distinct habitats, which themselves showed no direct influence on the composition of the gut microbiota. Conversely, niches such as the vagina demonstrated little to no decomposition into region-specific interactions. Diverse mechanisms underlay individual interactions, with some such as the co-exclusion of Porphyromonaceae family members and Streptococcus in the subgingival plaque supported by known biochemical dependencies. These differences varied among broad phylogenetic groups as well, with the Bacilli and Fusobacteria, for example, both enriched for exclusion of taxa from other clades. Comparing phylogenetic versus functional similarities among bacteria, we show that dominant commensal taxa (such as Prevotellaceae and Bacteroides in the gut) often compete, while potential pathogens (e.g. Treponema and Prevotella in the dental plaque) are more likely to co-occur in complementary niches. This approach thus serves to open new opportunities for future targeted mechanistic studies of the microbial ecology of the human microbiome.National Institutes of Health (U.S.) (grant CA139193)Fonds Wetenschappelijk Onderzoek â VlaanderenJuvenile Diabetes Research Foundation InternationalNational Institutes of Health (U.S.) (grant NIH U54HG004969)Crohn's and Colitis Foundation of AmericaNational Science Foundation (U.S.) (NSF DBI-1053486)United States. Army Research Office (ARO W911NF-11-1-0473)National Institutes of Health (U.S.) (grant NIH 1R01HG005969
Higher levels of glutamate in the associative-striatum of subjects with prodromal symptoms of schizophrenia and patients with first-episode psychosis
The glutamatergic and dopaminergic systems are thought to be involved in the pathophysiology of schizophrenia. Their interaction has been widely documented and may have a role in the neurobiological basis of the disease. The aim of this study was to compare, using proton magnetic resonance spectroscopy (1H-MRS), glutamate levels in the precommissural dorsal-caudate (a dopamine-rich region) and the cerebellar cortex (negligible for dopamine) in the following: (1) 18 antipsychotic-naĂŻve subjects with prodromal symptoms and considered to be at ultra high-risk for schizophrenia (UHR), (2) 18 antipsychotic-naĂŻve first- episode psychosis patients (FEP), and (3) 40 age- and sex- matched healthy controls. All subjects underwent a 1H-MRS study using a 3Tesla scanner. Glutamate levels were quantified and corrected for the proportion of cerebrospinal fluid and percentage of gray matter in the voxel. The UHR and FEP groups showed higher levels of glutamate than controls, without differences between UHR and FEP. In the cerebellum, no differences were seen between the three groups. The higher glutamate level in the precommissural dorsal-caudate and not in the cerebellum of UHR and FEP suggests that a high glutamate level (a) precedes the onset of schizophrenia, and (b) is present in a dopamine-rich region previously implicated in the pathophysiology of schizophrenia.peer-reviewe
Medical yoga: Another way of being in the world * A phenomenological study from the perspective of persons suffering from stress-related symptoms
Abstract The prevalence of stress-related illness has grown in recent years. Many of these patients seek help in primary health care. Yoga can reduce stress and thus complements pharmacological therapy in medical practice. To our knowledge, no studies have investigated patients' experiences of yoga treatment in a primary health care setting or, specifically, the experiences of yoga when suffering from stress-related illness. Thus, the aim of the present study was to explore the meaning of participating in medical yoga as a complementary treatment for stress-related symptoms and diagnosis in a primary health care setting. This study has a descriptive phenomenological design and took place at a primary health care centre in Sweden during 2011. Five women and one man (43Ă51 years) participated. They were recruited from the intervention group (n 018) in a randomized control trial, in which they had participated in a medical yoga group in addition to standard care for 12 weeks. Data were collected by means of qualitative interviews, and a phenomenological data analysis was conducted. The essential meaning of the medical yoga experience was that the medical yoga was not an endpoint of recovery but the start of a process towards an increased sense of wholeness. It was described as a way of alleviating suffering, and it provided the participants with a tool for dealing with their stress and current situation on a practical level. It led to greater selfawareness and self-esteem, which in turn had an implicit impact on their lifeworld. In phenomenological terms, this can be summarized as Another way of being in the world, encompassing a perception of deepened identity. From a philosophical perspective, due to using the body in a new way (yoga), the participants had learnt to see things differently, which enriched and recast their perception of themselves and their lives
Medical yoga: Another way of being in the world * A phenomenological study from the perspective of persons suffering from stress-related symptoms
Abstract The prevalence of stress-related illness has grown in recent years. Many of these patients seek help in primary health care. Yoga can reduce stress and thus complements pharmacological therapy in medical practice. To our knowledge, no studies have investigated patients' experiences of yoga treatment in a primary health care setting or, specifically, the experiences of yoga when suffering from stress-related illness. Thus, the aim of the present study was to explore the meaning of participating in medical yoga as a complementary treatment for stress-related symptoms and diagnosis in a primary health care setting. This study has a descriptive phenomenological design and took place at a primary health care centre in Sweden during 2011. Five women and one man (43Ă51 years) participated. They were recruited from the intervention group (n 018) in a randomized control trial, in which they had participated in a medical yoga group in addition to standard care for 12 weeks. Data were collected by means of qualitative interviews, and a phenomenological data analysis was conducted. The essential meaning of the medical yoga experience was that the medical yoga was not an endpoint of recovery but the start of a process towards an increased sense of wholeness. It was described as a way of alleviating suffering, and it provided the participants with a tool for dealing with their stress and current situation on a practical level. It led to greater selfawareness and self-esteem, which in turn had an implicit impact on their lifeworld. In phenomenological terms, this can be summarized as Another way of being in the world, encompassing a perception of deepened identity. From a philosophical perspective, due to using the body in a new way (yoga), the participants had learnt to see things differently, which enriched and recast their perception of themselves and their lives
Short-term effect of topical application of delmopinol on salivary microbiology, plaque, and gingivitis
Risk factors for thrombosis in patients with immune mediated heparin-induced thrombocytopenia
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