689 research outputs found
Variability in coronary hemodynamics in response to ergonovine in patients with normal coronary arteries and atypical chest pain
Because an increase in coronary vascular resistance in response to ergonovine maleate has been suggested as a possible diagnostic aid for variant angina, changes were evaluated in coronary hemodynamics and serial myocardial thallium-201 perfusion scans in 15 patients without angina and with normal coronary arteries in response to ergonovine (0.05, 0.10 and 0.20 mg intravenously). For the group, heart rate-blood pressure product increased significantly (p < 0.001) without any change in coronary sinus flow, coronary vascular resistance, myocardial oxygen extraction, arterial-coronary sinus oxygen difference and lactate extraction. In 7 of 15 patients, however, coronary vascular resistance increased (mean 39%, range 11 to 75%, probability [p] < 0.001), and coronary sinus flow decreased (14%, p < 0.001), despite an increase in heart rate-blood pressure product (36%, p < 0.02). No electrocardiographic, metabolic or thallium-201 scan abnormalities occurred. Therefore, significant increases in coronary vascular resistance in response to ergonovine may occur in patients with normal coronary arteries and atypical chest pain
Cultural Stressors, Identity Development, and Substance Use Attitudes Among Hispanic Immigrant Adolescents
The goal of this investigation was to determine whether various cultural stressors (bicultural stress, perceived discrimination, and perceived negative context of reception [PNCR]) predict positive and negative substance use attitudes, directly and indirectly through personal identity, in a sample of immigrant Hispanic adolescents. Data on cultural stressors, substance use attitudes, and covariates were collected from 302 Hispanic immigrant adolescents (152 from Miami [61% Cuban] and 150 from Los Angeles [70% Mexican]) at 3 time points. PNCR was associated with identity confusion (=.175, p=.033). Identity confusion significantly predicted higher positive attitudes toward alcohol and other drug (AOD; =.216, p\u3c.001) and cigarette use (=.191, p=.015) and mediated the relationship between PNCR with unfavorable AOD attitudes ( =-.019, 95% confidence interval [CI] [-0.052,-0.001]) and favorable AOD attitudes (=0.038, 95% CI [0.003, 0.086]). Perceptions of a negative context of reception may hinder successful personal identity formation and impact health outcomes for immigrant youth
Radio Astronomy
Contains reports on five research projects.National Aeronautics and Space Administration (Grant NsG-419)National Aeronautics and Space Administration (Contract NSR-22-009-120)Lincoln Laboratory Purchase Order No. 74
Committing to ecological restoration: Efforts around the globe need legal and policy clarification
At the September 2014 United Nations Climate Summit, governments rallied around an international agreement—the New York Declaration on Forests—that underscored restoration of degraded ecosystems as an auspicious solution to climate change. Ethiopia committed to restore more than one-sixth of its land. Uganda, the Democratic Republic of Congo, Guatemala, and Colombia pledged to restore huge areas within their borders. In total, parties committed to restore a staggering 350 million hectares by 2030.Fil: Suding, Kathering. State University Of Colorado-boulder; Estados UnidosFil: Higgs, Eric. University Of Victoria; CanadáFil: Palmer, Margaret. University of Maryland; Estados UnidosFil: Callicott, J. Baird. University Of North Texas; Estados UnidosFil: Anderson, Christopher Brian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Baker, Matthew. University Of Maryland; Estados UnidosFil: Gutrich, John J.. Southern Oregon University; Estados UnidosFil: Hondula, Kelly L.. University of Maryland; Estados UnidosFil: Lafevor, Matthew C.. University of Maryland; Estados UnidosFil: Larson, Brendon M. H.. University Of Waterloo; CanadáFil: Randall, Alan. Ohio State University; Estados Unidos. University Of Sidney; AustraliaFil: Ruhl, J. B.. Vanderbilt University; Estados UnidosFil: Schwartz, Katrina Z. S.. Woodrow Wilson International Center for Scholars; Estados Unido
Biculturalism Dynamics: A Daily Diary Study of Bicultural Identity and Psychosocial Functioning
We examined two conceptualizations of bicultural identity – the Bicultural Identity Integration (BII) framework (cultural identity blendedness-distance and harmony-conflict) and cultural hybridizing and alternating (mixing one’s two cultural identities and/or switching between them). Utilizing data from a 12-day diary study with 873 Hispanic college students, we examined three research questions: (1) cross-sectional and longitudinal intercorrelations among these biculturalism components, (2) links among daily variability in these biculturalism components, and (3) how this daily variability predicts well-being and mental health outcomes over time. Bicultural hybridizing was positively related to, and longitudinally predicted by, both BII blendedness and harmony. Daily fluctuation scores for BII blendedness, BII harmony, and bicultural hybridizing were strongly interrelated. Well-being was negatively predicted by fluctuations in hybridizing, whereas internalizing symptoms were positively predicted by fluctuations in blendedness. These results are discussed in terms of what biculturalism is and how best to promote it
RPGR-associated retinal degeneration in human X-linked RP and a murine model
PURPOSE. We investigated the retinal disease due to mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene in human patients and in an Rpgr conditional knockout (cko) mouse model. METHODS. XLRP patients with RPGR-ORF15 mutations (n = 35, ages at first visit 5–72 years) had clinical examinations, and rod and cone perimetry. Rpgr-cko mice, in which the proximal promoter and first exon were deleted ubiquitously, were back-crossed onto a BALB/c background, and studied with optical coherence tomography and electroretinography (ERG). Retinal histopathology was performed on a subset. RESULTS. Different patterns of rod and cone dysfunction were present in patients. Frequently, there were midperipheral losses with residual rod and cone function in central and peripheral retina. Longitudinal data indicated that central rod loss preceded peripheral rod losses. Central cone-only vision with no peripheral function was a late stage. Less commonly, patients had central rod and cone dysfunction, but preserved, albeit abnormal, midperipheral rod and cone vision. Rpgr-cko mice had progressive retinal degeneration detectable in the first months of life. ERGs indicated relatively equal rod and cone disease. At late stages, there was greater inferior versus superior retinal degeneration. CONCLUSIONS. RPGR mutations lead to progressive loss of rod and cone vision, but show different patterns of residual photoreceptor disease expression. Knowledge of the patterns should guide treatment strategies. Rpgr-cko mice had onset of degeneration at relatively young ages and progressive photoreceptor disease. The natural history in this model will permit preclinical proof-of-concept studies to be designed and such studies should advance progress toward human therapy
Comparison of the cellular cytotoxic activities of colostral lymphocytes and maternal peripheral blood lymphocytes
Colostral lymphocytes (CL) from mothers 2 to 4 days post-partum and autologous maternal peripheral blood lymphocytes (PBL) were investigated for (1) natural killer (NK) and antibody-dependent cellular cytotoxic (ADCC) activities, (2) target binding ability, (3) interferon (IFN)- and interleukin 2 (IL2)-induced augmentation of NK activity, (4) lectin-dependent cellular cytotoxicity (LDCC), and (5) the ability of culture-derived soluble suppressor factor(s) to inhibit the NK activity of normal allogeneic lymphocytes. CL depleted of adherent cells and Percoll-separated NK-enriched subpopulations of CL demonstrated significantly lower NK and ADCC activities compared to autologous PBL. However, the target binding ability of CL was comparable to autologous PBL. Although the residual NK activity of CL was augmented by IFN and IL2, the activity was not enhanced to the same level shown by autologous PBL. CL also demonstrated a significant enhancement of LDCC activity, although the activity was not stimulated to the levels shown by PBL. Culture supernates of CL manifested greater suppression of the NK ability of allogeneic PBL than culture supernates produced by autologous PBL. These results are consistent with a model that suggests differential partitioning of lymphocyte subpopulations between colostrum and peripheral blood.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25675/1/0000228.pd
Clinical significance of ventricular fibrillation-flutter induced by ventricular programmed stimulation
Two hundred twenty-four patients underwent ventricular programmed stimulation (VPS) without prior documentation of the clinical occurrence of sustained ventricular tachycardia (VT) or ventricular fibrillation-flutter (VF). Indications for VPS were: palpitations or nonsustained VT during ambulatory monitoring (85 patients), syncope or presyncope (137 patients), and a family history of sudden death (two patients). Sustained VF requiring transthoracic defibrillation was initiated by VPS in 18 patients (8.0%). Four patients were treated for inducible VF with antiarrhythmic agents directed by electropharmacologic testing; five patients were treated empirically; nine patients received no therapy. No patient has had a cardiac arrest or sudden death during a follow-up period of 25.2 +/- 13.8 months (mean +/- standard deviation). VF was initiated by two ventricular extrastimuli in three patients and by three extrastimuli in 15 patients. The incidence of VF was similar in patients with and without previous symptoms (8.8% vs 6.9%) or heart disease (7.1% vs 9.6%). It was significantly higher when VPS at three ventricular sites with a current of 5 mA (pulse width 2 msec) was compared to programmed stimulation at two ventricular sites with a current twice diastolic threshold (pulse width 2 msec) (15.2% vs 3.0%, p < 0.05). VF initiated by VPS in patients without prior VT or VF appears to be a nonspecific finding. Antiarrhythmic therapy for VF may not be necessary in these patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25695/1/0000249.pd
Longitudinal Trajectories of Family Functioning Among Recent Immigrant Adolescents and Parents: Links With Adolescent and Parent Cultural Stress, Emotional Wellâ Being, and Behavioral Health
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148234/1/cdev12914.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148234/2/cdev12914_am.pd
Exploiting MeSH indexing in MEDLINE to generate a data set for word sense disambiguation
<p>Abstract</p> <p>Background</p> <p>Evaluation of Word Sense Disambiguation (WSD) methods in the biomedical domain is difficult because the available resources are either too small or too focused on specific types of entities (e.g. diseases or genes). We present a method that can be used to automatically develop a WSD test collection using the Unified Medical Language System (UMLS) Metathesaurus and the manual MeSH indexing of MEDLINE. We demonstrate the use of this method by developing such a data set, called MSH WSD.</p> <p>Methods</p> <p>In our method, the Metathesaurus is first screened to identify ambiguous terms whose possible senses consist of two or more MeSH headings. We then use each ambiguous term and its corresponding MeSH heading to extract MEDLINE citations where the term and only one of the MeSH headings co-occur. The term found in the MEDLINE citation is automatically assigned the UMLS CUI linked to the MeSH heading. Each instance has been assigned a UMLS Concept Unique Identifier (CUI). We compare the characteristics of the MSH WSD data set to the previously existing NLM WSD data set.</p> <p>Results</p> <p>The resulting MSH WSD data set consists of 106 ambiguous abbreviations, 88 ambiguous terms and 9 which are a combination of both, for a total of 203 ambiguous entities. For each ambiguous term/abbreviation, the data set contains a maximum of 100 instances per sense obtained from MEDLINE.</p> <p>We evaluated the reliability of the MSH WSD data set using existing knowledge-based methods and compared their performance to that of the results previously obtained by these algorithms on the pre-existing data set, NLM WSD. We show that the knowledge-based methods achieve different results but keep their relative performance except for the Journal Descriptor Indexing (JDI) method, whose performance is below the other methods.</p> <p>Conclusions</p> <p>The MSH WSD data set allows the evaluation of WSD algorithms in the biomedical domain. Compared to previously existing data sets, MSH WSD contains a larger number of biomedical terms/abbreviations and covers the largest set of UMLS Semantic Types. Furthermore, the MSH WSD data set has been generated automatically reusing already existing annotations and, therefore, can be regenerated from subsequent UMLS versions.</p
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