1,763 research outputs found
Laser Light Scattering, from an Advanced Technology Development Program to Experiments in a Reduced Gravity Environment
Recent advancements in laser light scattering hardware are described. These include intelligent single card correlators; active quench/active reset avalanche photodiodes; laser diodes; and fiber optics which were used by or developed for a NASA advanced technology development program. A space shuttle experiment which will employ aspects of these hardware developments is previewed
Interfacial Self-Assembly of Water-Soluble Cationic Porphyrins for the Reduction of Oxygen to Water
AN APPEAL FROM JUDGMENT ENTERED BY THE THIRD JUDICIAL DISTRICT COURT, SALT LAKE COUNTY, STATE OF UTAH, MURRAY DEPARTMENT, The Hon. Michael K. Burton, Judge Presiding (Trial Court Case No. 00-201-0956
Detection of Mycosphaerella graminicola in Wheat Leaves by a Microsatellite Dinucleotide Specific-Primer
Early detection of infection is very important for efficient management of Mycosphaerella graminicola leaf blotch. To monitor and quantify the occurrence of this fungus during the growing season, a diagnostic method based on real-time PCR was developed. Standard and real-time PCR assays were developed using SYBR Green chemistry to quantify M. graminicola in vitro or in wheat samples. Microsatellite dinucleotide specific-primers were designed based on microsatellite repeats of sequences present in the genome of M. graminicola. Specificity was checked by analyzing DNA of 55 M. graminicola isolates obtained from different geographical origins. The method appears to be highly specific for detecting M. graminicola; no fluorescent signals were observed from 14 other closely related taxa. Primer (CT) 7 G amplified a specific amplicon of 570 bp from all M. graminicola isolates. The primers did not amplify DNA extracted from 14 other fungal species. The approximate melting temperature (Tm) of the (CT) 7 G primer was 84.2 °C. The detection limit of the real-time PCR assay with the primer sets (CT) 7 G is 10 fg/25 μL, as compared to 10 pg/25 μL using conventional PCR technology. From symptomless leaves, a PCR fragment could be generated two days after inoculation. Both conventional and real-time PCR could successfully detect the fungus from artificially inoculated wheat leaves. However, real-time PCR appeared much more sensitive than conventional PCR. The developed quantitative real-time PCR method proved to be rapid, sensitive, specific, cost-effective and reliable for the identification and quantification of M. graminicola in wheat
Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study
Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015
Transient Neuronal Populations Are Required to Guide Callosal Axons: A Role for Semaphorin 3C
Neurons, glia, and callosal axons operate as a “ménage à trois” in the development of the corpus callosum
Family physicians\u27 professional identity formation: a study protocol to explore impression management processes in institutional academic contexts.
BACKGROUND: Despite significant differences in terms of medical training and health care context, the phenomenon of medical students\u27 declining interest in family medicine has been well documented in North America and in many other developed countries as well. As part of a research program on family physicians\u27 professional identity formation initiated in 2007, the purpose of the present investigation is to examine in-depth how family physicians construct their professional image in academic contexts; in other words, this study will allow us to identify and understand the processes whereby family physicians with an academic appointment seek to control the ideas others form about them as a professional group, i.e. impression management.
METHODS/DESIGN: The methodology consists of a multiple case study embedded in the perspective of institutional theory. Four international cases from Canada, France, Ireland and Spain will be conducted; the \u22case\u22 is the medical school. Four levels of analysis will be considered: individual family physicians, interpersonal relationships, family physician professional group, and organization (medical school). Individual interviews and focus groups with academic family physicians will constitute the main technique for data generation, which will be complemented with a variety of documentary sources. Discourse techniques, more particularly rhetorical analysis, will be used to analyze the data gathered. Within- and cross-case analysis will then be performed.
DISCUSSION: This empirical study is strongly grounded in theory and will contribute to the scant body of literature on family physicians\u27 professional identity formation processes in medical schools. Findings will potentially have important implications for the practice of family medicine, medical education and health and educational policies
A Phylogenetic Analysis of Human Immunodeficiency Virus Type 1 Sequences in Kiev: Findings Among Key Populations
Background: The human immunodeficiency virus (HIV) epidemic in Ukraine has been driven by a rapid rise among people who inject drugs, but recent studies have shown an increase through sexual transmission. Methods: Protease and reverse transcriptase sequences from 876 new HIV diagnoses (April 2013–March 2015) in Kiev were linked to demographic data. We constructed phylogenetic trees for 794 subtype A1 and 64 subtype B sequences and identified factors associated with transmission clustering. Clusters were defined as ≥2 sequences, ≥80% local branch support, and maximum genetic distance of all sequence pairs in the cluster ≤2.5%. Recent infection was determined through the limiting antigen avidity enzyme immunoassay. Sequences were analyzed for transmitted drug resistance mutations. Results Thirty percent of subtype A1 and 66% of subtype B sequences clustered. Large clusters (maximum 11 sequences) contained mixed risk groups. In univariate analysis, clustering was significantly associated with subtype B compared to A1 (odds ratio [OR], 4.38 [95% confidence interval {CI}, 2.56–7.50]); risk group (OR, 5.65 [95% CI, 3.27–9.75]) for men who have sex with men compared to heterosexual males; recent, compared to long-standing, infection (OR, 2.72 [95% CI, 1.64–4.52]); reported sex work contact (OR, 1.93 [95% CI, 1.07–3.47]); and younger age groups compared with age ≥36 years (OR, 1.83 [95% CI, 1.10–3.05] for age ≤25 years). Females were associated with lower odds of clustering than heterosexual males (OR, 0.49 [95% CI, .31–.77]). In multivariate analysis, risk group, subtype, and age group were independently associated with clustering (P < .001, P = .007, and P = .033, respectively). Eighteen sequences (2.1%) indicated evidence of transmitted drug resistance. Conclusions Our findings suggest high levels of transmission and bridging between risk groups
PDRs4All II: JWST's NIR and MIR imaging view of the Orion Nebula
The JWST has captured the most detailed and sharpest infrared images ever
taken of the inner region of the Orion Nebula, the nearest massive star
formation region, and a prototypical highly irradiated dense photo-dissociation
region (PDR). We investigate the fundamental interaction of far-ultraviolet
photons with molecular clouds. The transitions across the ionization front
(IF), dissociation front (DF), and the molecular cloud are studied at
high-angular resolution. These transitions are relevant to understanding the
effects of radiative feedback from massive stars and the dominant physical and
chemical processes that lead to the IR emission that JWST will detect in many
Galactic and extragalactic environments. Due to the proximity of the Orion
Nebula and the unprecedented angular resolution of JWST, these data reveal that
the molecular cloud borders are hyper structured at small angular scales of
0.1-1" (0.0002-0.002 pc or 40-400 au at 414 pc). A diverse set of features are
observed such as ridges, waves, globules and photoevaporated protoplanetary
disks. At the PDR atomic to molecular transition, several bright features are
detected that are associated with the highly irradiated surroundings of the
dense molecular condensations and embedded young star. Toward the Orion Bar
PDR, a highly sculpted interface is detected with sharp edges and density
increases near the IF and DF. This was predicted by previous modeling studies,
but the fronts were unresolved in most tracers. A complex, structured, and
folded DF surface was traced by the H2 lines. This dataset was used to revisit
the commonly adopted 2D PDR structure of the Orion Bar. JWST provides us with a
complete view of the PDR, all the way from the PDR edge to the substructured
dense region, and this allowed us to determine, in detail, where the emission
of the atomic and molecular lines, aromatic bands, and dust originate
PDRs4All IV. An embarrassment of riches: Aromatic infrared bands in the Orion Bar
(Abridged) Mid-infrared observations of photodissociation regions (PDRs) are
dominated by strong emission features called aromatic infrared bands (AIBs).
The most prominent AIBs are found at 3.3, 6.2, 7.7, 8.6, and 11.2 m. The
most sensitive, highest-resolution infrared spectral imaging data ever taken of
the prototypical PDR, the Orion Bar, have been captured by JWST. We provide an
inventory of the AIBs found in the Orion Bar, along with mid-IR template
spectra from five distinct regions in the Bar: the molecular PDR, the atomic
PDR, and the HII region. We use JWST NIRSpec IFU and MIRI MRS observations of
the Orion Bar from the JWST Early Release Science Program, PDRs4All (ID: 1288).
We extract five template spectra to represent the morphology and environment of
the Orion Bar PDR. The superb sensitivity and the spectral and spatial
resolution of these JWST observations reveal many details of the AIB emission
and enable an improved characterization of their detailed profile shapes and
sub-components. While the spectra are dominated by the well-known AIBs at 3.3,
6.2, 7.7, 8.6, 11.2, and 12.7 m, a wealth of weaker features and
sub-components are present. We report trends in the widths and relative
strengths of AIBs across the five template spectra. These trends yield valuable
insight into the photochemical evolution of PAHs, such as the evolution
responsible for the shift of 11.2 m AIB emission from class B in
the molecular PDR to class A in the PDR surface layers. This
photochemical evolution is driven by the increased importance of FUV processing
in the PDR surface layers, resulting in a "weeding out" of the weakest links of
the PAH family in these layers. For now, these JWST observations are consistent
with a model in which the underlying PAH family is composed of a few species:
the so-called 'grandPAHs'.Comment: 25 pages, 10 figures, to appear in A&
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