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San Diego State University

EducationSan Diego, California, United States
About: San Diego State University is a education organization based out in San Diego, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 12418 authors who have published 27950 publications receiving 1192375 citations. The organization is also known as: SDSU & San Diego State College.


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Journal ArticleDOI
TL;DR: It is suggested, for the first time, that increased SERCA2 expression is feasible in vivo and results in enhanced calcium transients, myocardial contractility, and relaxation that may have further therapeutic implications.
Abstract: The Ca2+ ATPase of the sarcoplasmic reticulum (SERCA2) plays a dominant role in lowering cytoplasmic calcium levels during cardiac relaxation and reduction of its activity has been linked to delayed diastolic relaxation in hypothyroid and failing hearts. To determine the contractile alterations resulting from increased SERCA2 expression, we generated transgenic mice overexpressing a rat SERCA2 transgene. Characterization of a heterozygous transgenic mouse line (CJ5) showed that the amount of SERCA2 mRNA and protein increased 2. 6-fold and 1.2-fold, respectively, relative to control mice. Determination of the relative synthesis rate of SERCA2 protein showed an 82% increase. The mRNA levels of some of the other genes involved in calcium handling, such as the ryanodine receptor and calsequestrin, remained unchanged, but the mRNA levels of phospholamban and Na+/Ca2+ exchanger increased 1.4-fold and 1.8-fold, respectively. The increase in phospholamban or Na+/Ca2+ exchanger mRNAs did not, however, result in changes in protein levels. Functional analysis of calcium handling and contractile parameters in isolated cardiac myocytes indicated that the intracellular calcium decline (t1/2) and myocyte relengthening (t1/2) were accelerated by 23 and 22%, respectively. In addition, the rate of myocyte shortening was also significantly faster. In isolated papillary muscle from SERCA2 transgenic mice, the time to half maximum postrest potentiation was significantly shorter than in negative littermates. Furthermore, cardiac function measured in vivo, demonstrated significantly accelerated contraction and relaxation in SERCA2 transgenic mice that were further augmented in both groups with isoproterenol administration. Similar results were obtained for the contractile performance of myocytes isolated from a separate line (CJ2) of homozygous SERCA2 transgenic mice. Our findings suggest, for the first time, that increased SERCA2 expression is feasible in vivo and results in enhanced calcium transients, myocardial contractility, and relaxation that may have further therapeutic implications.

327 citations

Journal ArticleDOI
TL;DR: The authors conducted a study to understand factors that impacted the inquiry-based instruction of 14 beginning secondary science teachers, who were part of a collaborative university/school district induction program designed to facilitate inquirybased instruction.
Abstract: ‘Science as inquiry’ is a key content standard in the National Science Education Standards to be enacted by US science teachers. This paper is the result of a study that was conducted in order to understand factors that impacted the inquiry-based instruction of 14 beginning secondary science teachers. These teachers were part of a collaborative university/school district induction program designed to facilitate inquiry-based instruction. For a period of 1 year, the teachers were followed in an attempt to understand their teaching beliefs, instructional practices, knowledge of the nature of science and scientific inquiry, and their experiences with inquiry instruction in the classroom. Case and cross-case comparisons revealed five main constraints that impacted their enactment of inquiry-based instruction: an understanding of the nature of science and scientific inquiry, content knowledge, pedagogical content knowledge, teaching beliefs, and concerns about management and students. This study reinforces the...

326 citations

Journal ArticleDOI
TL;DR: There was limited evidence that both community design and access to recreation facilities variables were associated with adolescent physical activity, but additional built environment variables need to be studied that have particular relevance for youth.
Abstract: BACKGROUND: Neighborhood-level environmental features have been associated with adult physical activity and weight status, but this link has not been estab- lished for adolescents. METHODS: Community design and access to recreational facilities variables were derived using geographic information systems (GIS) for 799 adolescents (age 11 to 15 y, mean = 12.8 y, 53% girls, 43% ethnic minority). Environment variables were calculated for a 1-mile buffer around each participant's residence. Accelerometers measured min/d of physical activity. RESULTS: Number of nearby recreation facilities and number of nearby parks correlated positively with girls' physical activity, and intersection density inversely related to girls' physical activity. Retail floor area ratio correlated positively with boys' physical activity. No community design or access to recreation variables were related to BMI-percentile. CONCLUSIONS: There was limited evidence that both community design and access to recreation facilities variables were associated with adolescent physical activity, but additional built environment variables need to be studied that have particular relevance for youth. Key Words: children, exercise, obesity, built environment, policy, safe routes to school programs

326 citations

Journal ArticleDOI
TL;DR: In this paper, the authors report results of a study aimed at evaluating MODIS NPP/GPP products at six sites varying widely in climate, land use, and vegetation physiognomy.
Abstract: Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling issues that must be addressed to link ground measurements to the satellite-based carbon flux estimates. Here, we report results of a study aimed at evaluating MODIS NPP/GPP products at six sites varying widely in climate, land use, and vegetation physiognomy. Comparisons were made for twenty-five 1km 2 cells at each site, with 8-day averages for GPP and an annual value for NPP. The validation data layers were made with a combination of ground measurements, relatively high resolution satellite data (Landsat Enhanced Thematic Mapper Plus at � 30m resolution), and process-based modeling. There was strong seasonality in the MODIS GPP at all sites, and mean NPP ranged from 80gCm � 2 yr � 1 at an arctic tundra site to 550gCm � 2 yr � 1 at a temperate deciduous forest site. There was not a consistent over- or underprediction of NPP across sites relative to the validation estimates. The closest agreements in NPP and GPP were at the temperate deciduous forest, arctic tundra, and boreal forest sites. There was moderate underestimation in the MODIS products at the agricultural field site, and strong overestimation at the desert grassland and at the dry coniferous forest sites. Analyses of specific inputs to the MODIS NPP/ GPP algorithm ‐ notably the fraction of photosynthetically active radiation absorbed by the vegetation canopy, the maximum light use efficiency (LUE), and the climate data ‐ revealed the causes of the over- and underestimates. Suggestions for algorithm improvement include selectively altering values for maximum LUE (based on observations at eddy covariance flux towers) and parameters regulating autotrophic respiration.

326 citations

Journal ArticleDOI
TL;DR: Discriminant function analysis indicated that essential characteristics of self-determination predicted membership in the high QOL group and that overallSelf-determination and QOL were significantly correlated, as were sub-scale scores.
Abstract: Background The aim of this study was to evaluate the relationship between self-determination and quality of life (QOL) of persons with intellectual disabilities (ID) living in four countries (Canada, United States, Belgium and France). Method Participants were 182 adults with mild ID living in community settings (with families, living independently or in supported living environments). QOL was measured with the Quality of Life Questionnaire. Self-determination was measured using the Adult version of The Arc's Self-Determination Scale. Discriminant function and correlational analyses were conducted. Results Discriminant function analysis indicated that essential characteristics of self-determination predicted membership in the high QOL group and that overall self-determination and QOL were significantly correlated, as were sub-scale scores. Conclusions The study replicates findings from a previous study with an international sample and confirms the importance of self-determination to enhance QOL. Subsequent research should examine the direction of the relationship between self-determination and QOL and examine the relationship of essential characteristics of self-determined behaviour and core domains of QOL in greater detail.

325 citations


Authors

Showing all 12533 results

NameH-indexPapersCitations
David R. Williams1782034138789
James F. Sallis169825144836
Steven Williams144137586712
Larry R. Squire14347285306
Murray B. Stein12874589513
Robert Edwards12177574552
Roberto Kolter12031552942
Jack E. Dixon11540847201
Sonia Ancoli-Israel11552046045
John D. Lambris11465148203
Igor Grant11379155147
Kenneth H. Nealson10848351100
Mark Westoby10831659095
Eric Courchesne10724041200
Marc A. Schuckit10664343484
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202345
2022168
20211,595
20201,535
20191,454
20181,262