213 research outputs found
It's all in a day's work : an institutional analysis of the rehabilitation system
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1983.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Bibliography: leaves 364-370.by Deborah Ruth Schreiber.Ph.D
Contrasting Factors on the Kinetic Path to Protein Complex Formation Diminish the Effects of Crowding Agents
AbstractThe crowded environment of cells poses a challenge for rapid protein-protein association. Yet, it has been established that the rates of association are similar in crowded and in dilute solutions. Here we probe the pathway leading to fast association between TEM1 β-lactamase and its inhibitor protein BLIP in crowded solutions. We show that the affinity of the encounter complex, the rate of final complex formation, and the structure of the transition state are similar in crowded solutions and in buffer. The experimental results were reproduced by calculations based on the transient-complex theory for protein association. Both experiments and calculations suggest that while crowding agents decrease the diffusion constant of the associating proteins, they also induce an effective excluded-volume attraction between them. The combination of the two opposing effects thus results in nearly identical overall association rates in diluted and crowded solutions
The Iowa Homemaker vol.26, no.7
Five-Pound Party Planning, Ruth Hackett, page 2
Homemaking Under the Round Roof, Shirliann Fortmann, page 3
Home Economists Look to New Horizons, Katherine Goeppinger, page 4
Graduate Studies Solve Research Questions, Marjorie Clampitt, page 5
Headlines Challenge Home Economists, Eloise Davison, page 6
Both Sides of the Pacific, Margaret Waterland, page 7
Wardrobe Accompaniments Chase Winter Blues, Jean Bunge, page 8
Home Economics Journeys from Iowa State to China, Jean Ory, page 9
What’s New, Marjorie Clampitt, page 10
Shoe Care Means Longer Wear, Charlene Stettler, page 11
Counselling Homemakers is Fun, Sue Marie Schreiber, page 12
Glamour is Her Business, Mary Margaret Ryan, page 13
Notions for Campus and Home, Margaret Buswell, page 14
’46 Graduate Combines College and Career, Beverly Seig, page 15
Keeping Up With Today, Joyce Edgar, page 1
The structures and total (minor + major) merger histories of massive galaxies up to z = 3 in the HST GOODS NICMOS Survey: A possible solution to the size evolution problem
We investigate the total major (> 1:4 by stellar mass) and minor (> 1:100 by
stellar mass) merger history of a population of 80 massive (M_* > 10^11 M_sol)
galaxies at high redshifts (z = 1.7 - 3). We utilize extremely deep and high
resolution HST H-band imaging from the GOODS NICMOS Survey (GNS), which
corresponds to rest-frame optical wavelengths at the redshifts probed. We find
that massive galaxies at high redshifts are often morphologically disturbed,
with a CAS deduced merger fraction f_m = 0.23 +/- 0.05 at z = 1.7 - 3. We find
close accord between close pair methods (within 30 kpc apertures) and CAS
methods for deducing major merger fractions at all redshifts. We deduce the
total (minor + major) merger history of massive galaxies with M_* > 10^9 M_sol
galaxies, and find that this scales roughly linearly with log-stellar-mass and
magnitude range. We test our close pair methods by utilizing mock galaxy
catalogs from the Millennium Simulation. We compute the total number of mergers
to be (4.5 +/- 2.9) / from z = 3 to the present, to a stellar mass
sensitivity threshold of ~ 1:100 (where \tau_m is the merger timescale in Gyr
which varies as a function of mass). This corresponds to an average mass
increase of (3.4 +/- 2.2) x 10^11 M_sol over the past 11.5 Gyrs due to merging.
We show that the size evolution observed for these galaxies may be mostly
explained by this merging.Comment: 19 pages, 10 figures, re-submitted to ApJ after a positive referee
report, originally submitted on Sept 20 201
Effects of b-lactam antibiotics and fluoroquinolones on human gut microbiota in relation to clostridium difficile associated diarrhea
Clostridium difficile infections are an emerging health problem in the modern hospital environment. Severe alterations of the gut microbiome with loss of resistance to colonization against C. difficile are thought to be the major trigger, but there is no clear concept of how C. difficile infection evolves and which microbiological factors are involved. We sequenced 16S rRNA amplicons generated from DNA and RNA/cDNA of fecal samples from three groups of individuals by FLX technology: (i) healthy controls (no antibiotic therapy); (ii) individuals receiving antibiotic therapy (Ampicillin/Sulbactam, cephalosporins, and fluoroquinolones with subsequent development of C. difficile infection or (iii) individuals receiving antibiotic therapy without C. difficile infection. We compared the effects of the three different antibiotic classes on the intestinal microbiome and the effects of alterations of the gut microbiome on C. difficile infection at the DNA (total microbiota) and rRNA (potentially active) levels. A comparison of antibiotic classes showed significant differences at DNA level, but not at RNA level. Among individuals that developed or did not develop a C. difficile infection under antibiotics we found no significant differences. We identified single species that were up- or down regulated in individuals receiving antibiotics who developed the infection compared to non-infected individuals. We found no significant differences in the global composition of the transcriptionally active gut microbiome associated with C. difficile infections. We suggest that up- and down regulation of specific bacterial species may be involved in colonization resistance against C. difficile providing a potential therapeutic approach through specific manipulation of the intestinal microbiome.This work was supported by the ERANET Project PathoGenoMics program grant number 0315441A.Peer Reviewe
Countercurrent chromatography in analytical chemistry (IUPAC technical report)
© 2009 IUPACCountercurrent chromatography (CCC) is a generic term covering all forms of liquid-liquid chromatography that use a support-free liquid stationary phase held in place by a simple centrifugal or complex centrifugal force field. Biphasic liquid systems are used with one liquid phase being the stationary phase and the other being the mobile phase. Although initiated almost 30 years ago, CCC lacked reliable columns. This is changing now, and the newly designed centrifuges appearing on the market make excellent CCC columns. This review focuses on the advantages of a liquid stationary phase and addresses the chromatographic theory of CCC. The main difference with classical liquid chromatography (LC) is the variable volume of the stationary phase. There are mainly two different ways to obtain a liquid stationary phase using centrifugal forces, the hydrostatic way and the hydrodynamic way. These two kinds of CCC columns are described and compared. The reported applications of CCC in analytical chemistry and comparison with other separation and enrichment methods show that the technique can be successfully used in the analysis of plants and other natural products, for the separation of biochemicals and pharmaceuticals, for the separation of alkaloids from medical herbs, in food analysis, etc. On the basis of the studies of the last two decades, recommendations are also given for the application of CCC in trace inorganic analysis and in radioanalytical chemistry
Galaxy Zoo: CANDELS barred discs and bar fractions
The formation of bars in disc galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in discs decreases from the local Universe to z ~ 1, and by z > 1 simulations predict that bar features in dynamically mature discs should be extremely rare. Here, we report the discovery of strong barred structures in massive disc galaxies at z ~ 1.5 in deep rest-frame optical images from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey. From within a sample of 876 disc galaxies identified by visual classification in Galaxy Zoo, we identify 123 barred galaxies. Selecting a subsample within the same region of the evolving galaxy luminosity function (brighter than L*), we find that the bar fraction across the redshift range 0.5 ≤ z ≤ 2 (fbar = 10.7+6.3 -3.5 per cent after correcting for incompleteness) does not significantly evolve.We discuss the implications of this discovery in the context of existing simulations and our current understanding of the way disc galaxies have evolved over the last 11 billion yearsPeer reviewedFinal Accepted Versio
Hypoparathyroidism-retardation-dysmorphism syndrome—Clinical insights from a large longitudinal cohort in a single medical center
BackgroundHypoparathyroidism, retardation, and dysmorphism (HRD) Syndrome is a rare disease composed of hypoparathyroidism, retardation of both growth and development, and distinctive dysmorphic features. Here, we describe the long-term morbidity and mortality in a large cohort of HRD patients and suggest recommendations for follow up and treatment.MethodsMedical records of 63 HRD syndrome patients who were followed at Soroka Medical Center during 1989–2019 were reviewed retrospectively. Information regarding demographics, medical complications, laboratory findings, and imaging studies was collected.ResultsThe mortality rate was 52%. The main causes of death were infectious diseases including pneumonia, septic shock, and meningitis. Multiple comorbidities were found including brain anomalies in 90% of examined patients (basal ganglia calcifications, tightening of corpus callosum, Chiari malformation, hydrocephalous, and brain atrophy), seizures in 62%, nephrocalcinosis and/or nephrolithiasis in 47%, multiple eye anomalies were recorded in 40%, bowel obstructions in 9.5%, and variable expression of both conductive and senso-neural hearing loss was documented in 9.5%.ConclusionHRD is a severe multisystem disease. Active surveillance is indicated to prevent and treat complications associated with this rare syndrome
Hundreds of variants clustered in genomic loci and biological pathways affect human height
Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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