Block Groups (block + groups)

Distribution by Scientific Domains


Selected Abstracts


Adaptation of normal and hypofunctional masseter muscle after bite-raising in growing rats

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2000
Andrea Bresin
The aim of this study was to analyze the effects of prolonged muscular elongation induced by bite-raising on the length of the muscle belly, sarcomeres and aponeurosis of the anterior deep masseter in the growing rat. Another aim was to determine the role of different functional conditions of this muscle in the adaptation process. Ninety-six young male rats were split into two groups: one was fed a hard diet and the other a soft diet to develop different functional capacities in the masticatory muscles. After 2 wk, half of the rats in both groups were fitted with an appliance that raised the bite by 2 mm. The measurements on the muscles were performed in situ. The insertion of the appliance stretched the anterior masseter muscle. After 4 wk, the vertical dentoskeletal dimension, the muscle belly, and the sarcomeres showed no difference in length among the groups. However, the aponeurosis was longer in the rats wearing the appliance compared to the controls, and among the bite block groups it was longer in the rats fed a hard diet. Length adaptation occurred in the aponeurosis. Clinically this may imply a need for reactivation of functional appliances to increase their efficiency, at a rate possibly depending on masseter muscles functional condition. [source]


Population Estimation Using Landsat Enhanced Thematic Mapper Imagery

GEOGRAPHICAL ANALYSIS, Issue 1 2007
Changshan Wu
An assessment of two groups of approaches for estimating urban population with remote-sensing information is presented in this article. These approaches, zonal and pixel-based models, are applied to Landsat Enhanced Thematic Mapper images of a portion of Columbus, Ohio, to generate population estimates. The zonal approach uses impervious surface fraction, spectral radiance, and land-use/land-cover classification to derive population estimates. The pixel-based approach uses impervious surface fraction and spectral radiance to estimate the population of residential areas. To assess robustness, these models were applied to Dayton, Ohio. A comparative study indicates that the models generated promising results in estimating regional population counts. However, zonal regression with spectral radiance produced large errors (76%) for census block groups, whereas other models gave significantly better estimation accuracy. Comparing the performance of the indicators, impervious surface fraction is competitive, and slightly but consistently better than land-use classification. In comparison with traditional zonal approaches, pixel-based models give somewhat better estimation accuracy. [source]


Community and Individual Race/Ethnicity and Home Health Care Use among Elderly Persons in the United States

HEALTH SERVICES RESEARCH, Issue 5p1 2010
James B. Kirby
Objective. To investigate whether the interaction between individual race/ethnicity and community racial/ethnic composition is associated with health-related home care use among elderly persons in the United States. Data Sources. A nationally representative sample of community-dwelling elders aged 65+ from the 2000 to 2006 Medical Expenditure Panel Survey (N=23,792) linked to block group-level racial/ethnic information from the 2000 Decennial Census. Design. We estimated the likelihood of informal and formal home health care use for four racial/ethnic elderly groups (non-Hispanic [NH] whites, NH-blacks, NH-Asians, and Hispanics) living in communities with different racial/ethnic compositions. Principal Findings. NH-Asian and Hispanic elders living in block groups with ,25 percent of residents being NH-Asian or Hispanic, respectively, were more likely to use informal home health care than their counterparts in other block groups. No such effect was apparent for formal home health care. Conclusions. NH-Asian and Hispanic elders are more likely to use informal home care if they live in communities with a higher proportion of residents who share their race/ethnicity. A better understanding of how informal care is provided in different communities may inform policy makers concerned with promoting informal home care, supporting informal caregivers, or providing formal home care as a substitute or supplement to informal care. [source]


TRENDS IN NEIGHBORHOOD INCOME INEQUALITY IN THE U.S.: 1980,2000,

JOURNAL OF REGIONAL SCIENCE, Issue 5 2008
Christopher H. Wheeler
ABSTRACT This paper reports evidence on the geographic pattern of income inequality, both within and between neighborhoods, across a sample of 359 U.S. metropolitan areas between 1980 and 2000. The results indicate that overall income inequality within a metro area tends to be driven by variation within neighborhoods, not between them, although we find that between-neighborhood differences rose dramatically during the 1980s and subsided somewhat during the 1990s. While this trend is similar to what existing research has found, our findings reveal potentially important differences in the magnitudes of the changes depending on whether neighborhoods are defined by block groups or tracts. [source]


Unilateral groin surgery in children: will the addition of an ultrasound-guided ilioinguinal nerve block enhance the duration of analgesia of a single-shot caudal block?

PEDIATRIC ANESTHESIA, Issue 9 2009
NARASIMHAN JAGANNATHAN MD
Summary Background:, Inguinal hernia repair, hydrocelectomy, and orchidopexy are commonly performed surgical procedures in children. Postoperative pain control is usually provided with a single-shot caudal block. Blockade of the ilioinguinal nerve may lead to additional analgesia. The aim of this double-blind, randomized controlled trial was to evaluate the efficacy of an adjuvant blockade of the ilioinguinal nerve using ultrasound (US) guidance at the end of the procedure with local anesthetic vs normal saline and to explore the potential for prolongation of analgesia with decreased need for postoperative pain medication. Methods:, Fifty children ages 1,6 years scheduled for unilateral inguinal hernia repair, hydrocelectomy, orchidopexy, or orchiectomy were prospectively randomized into one of two groups: Group S that received an US-guided ilioinguinal nerve block with 0.1 ml·kg,1 of preservative-free normal saline and Group B that received an US-guided nerve block with 0.1 ml·kg,1 of 0.25% bupivacaine with 1 : 200 000 epinephrine at the conclusion of the surgery. After induction of anesthesia but prior to surgical incision, all patients received caudal anesthesia with 0.7 ml·kg,1 of 0.125% bupivacaine with 1 : 200 000 epinephrine. Patients were observed by a blinded observer for (i) pain scores using the Children and Infants Postoperative Pain Scale, (ii) need for rescue medication in the PACU, (iii) need for oral pain medications given by the parents at home. Results:, Forty-eight patients, consisting of 46 males and two females, with a mean age of 3.98 (sd ± 1.88) were enrolled in the study. Two patients were excluded from the study because of study protocol violation and/or alteration in surgical procedure. The average pain scores reported for the entire duration spent in the recovery room for the caudal and caudal/ilioinguinal block groups were 1.92 (sd ± 1.59) and 1.18 (sd ± 1.31), respectively. The average pain score difference was 0.72 (sd ± 0.58) and was statistically significant (P < 0.05). In addition, when examined by procedure type, it was found that the difference in the average pain scores between the caudal and caudal/ilioinguinal block groups was statistically significant for the inguinal hernia repair patients (P < 0.05) but not for the other groin surgery patients (P = 0.13). For all groin surgery patients, six of the 23 patients in the caudal group and eight of the 25 patients in the caudal/ilioinguinal block group required pain rescue medications throughout their entire hospital stay or at home (P = 0.76). Overall, the caudal group received an average of 0.54 (sd ± 1.14) pain rescue medication doses, while the caudal/ilioinguinal block group received an average of 0.77 (sd ± 1.70) pain rescue medication doses; this was, however, not statistically significant (P = 0.58). Conclusions:, The addition of an US-guided ilioinguinal nerve block to a single-shot caudal block decreases the severity of pain experienced by pediatric groin surgery patients. The decrease in pain scores were particularly pronounced in inguinal hernia repair patients. [source]