2,349 research outputs found
Planning at the Grass Roots Level: The Guilford County Citizen Participation Program
Historically, local governments in this country have focused their programs and priorities almost exclusively on urban areas, where population, resources, and problems are most concentrated. Rural dwellers, by contrast, have been avoided by planners and other officials, their needs being left to such rural-oriented agencies as the Agricultural Extension Service. In the late summer of 1973, Guilford County Government and its citizens broke that tradition. Stimulated primarily by the need to dampen citizen dissatisfaction with land use regulations, the County Government set out to organize the citizens of its rural and suburban areas around community defined issues and problems. What has resulted is a community organization directly involving the citizens of Guilford County. Among their accomplishments to date have been the formation of a summer recreation program, a rural garbage collection study, a rural-suburban land use committee, and a citizen's budget committee. Prior to this effort, "citizen input" into the planning process of Guilford County came only through such conventional arrangements as public hearings on specific proposals, routine board or commission meetings, political representation, or the electoral process. As it was implemented in 1973, the "Community Councils Program" was a significant departure from this norm, because, one, it was non-urban in focus; two, its base was grass-roots community organization rather than individually oriented; and three, it attempted to involve organized county residents early in the planning stages of both short and long-range governmental decisions. Moreover, as a form of decentralization of political power toward the "county-wide" community and toward the local communities, its conceptualization and practice were a far cry from the rubber-stamp public hearing, the hand-picked board or commission, or the infrequent ritual of selecting remote decision-makers through the electoral process
Tobramycin-Treated Pseudomonas aeruginosa PA14 Enhances Streptococcus constellatus 7155 Biofilm Formation in a Cystic Fibrosis Model System
Cystic fibrosis (CF) is a human genetic disorder which results in a lung environment that is highly conducive to chronic microbial infection. Over the past decade, deep-sequencing studies have demonstrated that the CF lung can harbor a highly diverse polymicrobial community. We expanded our existing in vitro model of Pseudomonas aeruginosa biofilm formation on CF-derived airway cells to include this broader set of CF airway colonizers to investigate their contributions to CF lung disease, particularly as they relate to the antibiotic response of the population. Using this system, we identified an interspecies interaction between P. aeruginosa, a bacterium associated with declining lung function and worsening disease, and Streptococcus constellatus, a bacterium correlated with the onset of pulmonary exacerbations in CF patients. The growth rate and cytotoxicity of S. constellatus 7155 and P. aeruginosa PA14 were unchanged when grown together as mixed biofilms in the absence of antibiotics. However, the addition of tobramycin, the frontline maintenance therapy antibiotic for individuals with CF, to a mixed biofilm of S. constellatus 7155 and P. aeruginosa PA14 resulted in enhanced S. constellatus biofilm formation. Through a candidate genetic approach, we showed that P. aeruginosa rhamnolipids were reduced upon tobramycin exposure, allowing for S. constellatus 7155 biofilm enhancement, and monorhamnolipids were sufficient to reduce S. constellatus 7155 biofilm viability in the absence of tobramycin. While the findings presented here are specific to a biofilm of S. constellatus 7155 and P. aeruginosa PA14, they highlight the potential of polymicrobial interactions to impact antibiotic tolerance in unanticipated ways
Dispersed Repetitive DNA Has Spread to New Genomes Since Polyploid Formation in Cotton
Polyploid formation has played a major role in the evolution of many plant and animal genomes; however, surprisingly little is known regarding the subsequent evolution of DNA sequences that become newly united in a common nucleus. Of particular interest is the repetitive DNA fraction, which accounts for most nuclear DNA in higher plants and animals and which can be remarkably different, even in closely related taxa. In one recently formed polyploid, cotton (Gossypium barbadense L.; AD genome), 83 non-cross-hybridizing DNA clones contain dispersed repeats that are estimated to comprise about 24% of the nuclear DNA. Among these, 64 (77%) are largely restricted to diploid taxa containing the larger A genome and collectively account for about half of the difference in DNA content between Old World (A) and New World (D) diploid ancestors of cultivated AD tetraploid cotton. In tetraploid cotton, FISH analysis showed that some A-genome dispersed repeats appear to have spread to D-genome chromosomes. Such spread may also account for the finding that one, and only one, D-genome diploid cotton, Gossypium gossypioides, contains moderate levels of (otherwise) A-genome-specific repeats in addition to normal levels of D-genome repeats. The discovery of A-genome repeats in G. gossypioides adds genome-wide support to a suggestion previously based on evidence from only a single genetic locus that this species may be either the closest living descendant of the New World cotton ancestor, or an adulterated relic of polyploid formation. Spread of dispersed repeats in the early stages of polyploid formation may provide a tag to identify diploid progenitors of a polyploid. Although most repetitive clones do not correspond to known DNA sequences, 4 correspond to known transposons, most contain internal subrepeats, and at least 12 (including 2 of the possible transposons) hybridize to mRNAs expressed at readily discernible levels in cotton seedlings, implicating transposition as one possible mechanism of spread. Integration of molecular, phylogenetic, and cytogenetic analysis of dispersed repetitive DNA may shed new light on evolution of other polyploid genomes, as well as providing valuable landmarks for many aspects of genome analysis
Talking Points on Publicly Engaged Scholarship at IUPUI
Talking Points on Publicly Engaged Scholarship at IUPUI
Informed by Public Scholarship at Indiana University-Purdue University Indianapolis, a concept paper written by the Faculty Learning Community (FLC) on Public Scholarship and refined through ongoing FLC work between 2015-18 in collaboration with faculty across the campus and with nationally-recognized scholars
Interactions between downslope flows and a developing cold-air pool
A numerical model has been used to characterize the development of a region of enhanced cooling in an alpine valley with a width of order (Formula presented.) km, under decoupled stable conditions. The region of enhanced cooling develops largely as a region of relatively dry air which partitions the valley atmosphere dynamics into two volumes, with airflow partially trapped within the valley by a developing elevated inversion. Complex interactions between the region of enhanced cooling and the downslope flows are quantified. The cooling within the region of enhanced cooling and the elevated inversion is almost equally partitioned between radiative and dynamic effects. By the end of the simulation, the different valley atmospheric regions approach a state of thermal equilibrium with one another, though this cannot be said of the valley atmosphere and its external environment.Peer reviewe
Balancing Selection on a Regulatory Region Exhibiting Ancient Variation That Predates Human–Neandertal Divergence
Ancient population structure shaping contemporary genetic variation has been recently appreciated and has important implications regarding our understanding of the structure of modern human genomes. We identified a ∼36-kb DNA segment in the human genome that displays an ancient substructure. The variation at this locus exists primarily as two highly divergent haplogroups. One of these haplogroups (the NE1 haplogroup) aligns with the Neandertal haplotype and contains a 4.6-kb deletion polymorphism in perfect linkage disequilibrium with 12 single nucleotide polymorphisms (SNPs) across diverse populations. The other haplogroup, which does not contain the 4.6-kb deletion, aligns with the chimpanzee haplotype and is likely ancestral. Africans have higher overall pairwise differences with the Neandertal haplotype than Eurasians do for this NE1 locus (p<10−15). Moreover, the nucleotide diversity at this locus is higher in Eurasians than in Africans. These results mimic signatures of recent Neandertal admixture contributing to this locus. However, an in-depth assessment of the variation in this region across multiple populations reveals that African NE1 haplotypes, albeit rare, harbor more sequence variation than NE1 haplotypes found in Europeans, indicating an ancient African origin of this haplogroup and refuting recent Neandertal admixture. Population genetic analyses of the SNPs within each of these haplogroups, along with genome-wide comparisons revealed significant FST (p = 0.00003) and positive Tajima's D (p = 0.00285) statistics, pointing to non-neutral evolution of this locus. The NE1 locus harbors no protein-coding genes, but contains transcribed sequences as well as sequences with putative regulatory function based on bioinformatic predictions and in vitro experiments. We postulate that the variation observed at this locus predates Human–Neandertal divergence and is evolving under balancing selection, especially among European populations
Aberrant developmental titin splicing and dysregulated sarcomere length in Thymosin β4 knockout mice
Sarcomere assembly is a highly orchestrated and dynamic process which adapts, during perinatal development, to accommodate growth of the heart. Sarcomeric components, including titin, undergo an isoform transition to adjust ventricular filling. Many sarcomeric genes have been implicated in congenital cardiomyopathies, such that understanding developmental sarcomere transitions will inform the aetiology and treatment. We sought to determine whether Thymosin β4 (Tβ4), a peptide that regulates the availability of actin monomers for polymerization in non-muscle cells, plays a role in sarcomere assembly during cardiac morphogenesis and influences adult cardiac function. In Tβ4 null mice, immunofluorescence-based sarcomere analyses revealed shortened thin filament, sarcomere and titin spring length in cardiomyocytes, associated with precocious up-regulation of the short titin isoforms during the postnatal splicing transition. By magnetic resonance imaging, this manifested as diminished stroke volume and limited contractile reserve in adult mice. Extrapolating to an in vitro cardiomyocyte model, the altered postnatal splicing was corrected with addition of synthetic Tβ4, whereby normal sarcomere length was restored. Our data suggest that Tβ4 is required for setting correct sarcomere length and for appropriate splicing of titin, not only in the heart but also in skeletal muscle. Distinguishing between thin filament extension and titin splicing as the primary defect is challenging, as these events are intimately linked. The regulation of titin splicing is a previously unrecognised role of Tβ4 and gives preliminary insight into a mechanism by which titin isoforms may be manipulated to correct cardiac dysfunction
The High Resolution IRAS Galaxy Atlas
An atlas of the Galactic plane (-4.7 deg < b < 4.7 deg) plus the molecular
clouds in Orion, Rho Oph, and Taurus-Auriga has been produced at 60 and 100
micron from IRAS data. The Atlas consists of resolution-enhanced coadded images
having 1 arcmin -- 2 arcmin resolution as well as coadded images at the native
IRAS resolution. The IRAS Galaxy Atlas, together with the DRAO HI line / 21 cm
continuum and FCRAO CO (1-0) line Galactic plane surveys, both with similar
(approx. 1 arcmin) resolution, provide a powerful venue for studying the
interstellar medium, star formation and large scale structure in our Galaxy.
This paper documents the production and characteristics of the Atlas.Comment: To appear in Astrophysical Journal Supplement Series. Replaced June
2, 1997. Text unchanged. Missing tables added. Wrong figure sequence
corrected. The Atlas images can now be accessed on line at
http://crystal.ipac.caltech.edu:8001/applications/IGA
Early pre-radiographic structural pathology precedes the onset of accelerated knee osteoarthritis.
BACKGROUND: Accelerated knee osteoarthritis (AKOA) is characterized by more pain, impaired physical function, and greater likelihood to receive a joint replacement compared to individuals who develop the typical gradual onset of disease. Prognostic tools are needed to determine which structural pathologies precede the development of AKOA compared to individuals without AKOA. Therefore, the purpose of this manuscript was to determine which pre-radiographic structural features precede the development of AKOA. METHODS: The sample comprised participants in the Osteoarthritis Initiative (OAI) who had at least one radiographically normal knee at baseline (Kellgren-Lawrence [KL] grade  3) and No AKOA. The index visit was the study visit when participants met criteria for AKOA or a matched timepoint for those who did not develop AKOA. Magnetic resonance (MR) images were assessed for 12 structural features at the OAI baseline, and 1 and 2 years prior to the index visit. Separate logistic regression models (i.e. OAI baseline, 1 and 2 years prior) were used to determine which pre-radiographic structural features were more likely to antedate the development of AKOA compared to individuals not developing AKOA. RESULTS: At the OAI baseline visit, degenerative cruciate ligaments (Odds Ratio [OR] = 2.2, 95% Confidence Interval [CI] = 1.3,3.5), infrapatellar fat pad signal intensity alteration (OR = 2.0, 95%CI = 1.2,3.2), medial/lateral meniscal pathology (OR = 2.1/2.4, 95%CI = 1.3,3.4/1.5,3.8), and greater quantitative knee effusion-synovitis (OR = 2.2, 95%CI = 1.4,3.4) were more likely to antedate the development of AKOA when compared to those that did not develop AKOA. These results were similar at one and two years prior to disease onset. Additionally, medial meniscus extrusion at one year prior to disease onset (OR = 3.5, 95%CI = 2.1,6.0) increased the likelihood of developing AKOA. CONCLUSIONS: Early ligamentous degeneration, effusion/synovitis, and meniscal pathology precede the onset of AKOA and may be prognostic biomarkers
Composite quantitative knee structure metrics predict the development of accelerated knee osteoarthritis:data from the osteoarthritis initiative
BACKGROUND: We aimed to determine if composite structural measures of knee osteoarthritis (KOA) progression on magnetic resonance (MR) imaging can predict the radiographic onset of accelerated knee osteoarthritis. METHODS: We used data from a nested case-control study among participants from the Osteoarthritis Initiative without radiographic KOA at baseline. Participants were separated into three groups based on radiographic disease progression over 4 years: 1) accelerated (Kellgren-Lawrence grades [KL] 0/1 to 3/4), 2) typical (increase in KL, excluding accelerated osteoarthritis), or 3) no KOA (no change in KL). We assessed tibiofemoral cartilage damage (four regions: medial/lateral tibia/femur), bone marrow lesion (BML) volume (four regions: medial/lateral tibia/femur), and whole knee effusion-synovitis volume on 3 T MR images with semi-automated programs. We calculated two MR-based composite scores. Cumulative damage was the sum of standardized cartilage damage. Disease activity was the sum of standardized volumes of effusion-synovitis and BMLs. We focused on annual images from 2 years before to 2 years after radiographic onset (or a matched time for those without knee osteoarthritis). To determine between group differences in the composite metrics at all time points, we used generalized linear mixed models with group (3 levels) and time (up to 5 levels). For our prognostic analysis, we used multinomial logistic regression models to determine if one-year worsening in each composite metric change associated with future accelerated knee osteoarthritis (odds ratios [OR] based on units of 1 standard deviation of change). RESULTS: Prior to disease onset, the accelerated KOA group had greater average disease activity compared to the typical and no KOA groups and this persisted up to 2 years after disease onset. During a pre-radiographic disease period, the odds of developing accelerated KOA were greater in people with worsening disease activity [versus typical KOA OR (95% confidence interval [CI]): 1.58 (1.08 to 2.33); versus no KOA: 2.39 (1.55 to 3.71)] or cumulative damage [versus typical KOA: 1.69 (1.14 to 2.51); versus no KOA: 2.11 (1.41 to 3.16)]. CONCLUSIONS: MR-based disease activity and cumulative damage metrics may be prognostic markers to help identify people at risk for accelerated onset and progression of knee osteoarthritis
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