1,680 research outputs found
Fluency of School-Aged Children With a History of Specific Expressive Language Impairment: An Exploratory Study
A large volume of literature now links
language demand and fluency behaviors in
children. Although it might be reasonable to
assume that children with relatively weak
language skills might demonstrate higher levels
of disfluency, the sparse literature on this topic
is characterized by conflicting findings on the
relationship between language impairment and
disfluency. However, in studies finding elevated
disfluency in children with specific language
impairment, a higher frequency of disfluencies
more characteristic of stuttering has been
noted. This study asks whether children with
long-standing histories of language delay and
impairment are more disfluent, and display
different types of disfluencies than their
typically developing, age-matched peers. Elicited narratives from 22 pairs of 9-year-old
children were analyzed for fluency characteristics.
Half of the children had histories of specific
expressive language impairment (HSLI-E),
whereas the others had typical developmental
histories. The children with HSLI-E were
significantly more disfluent than their peers and
produced more stutter-like disfluencies,
although these behaviors were relatively
infrequent in both groups. Implications for
clinical intervention and future research are
discussed
Syllable structure development of toddlers with expressive specific language impairment
A total of 35 children – 20 with expressive specific language impairment (SLI-E) and 15 typically developing (TD) peers – were compared longitudinally from 24 to 36 months with respect to their production of syllable shapes in 10-minute spontaneous speech samples. SLI-E 24-month-olds predominantly
produced earlier developing syllable shapes containing vowels, liquids, and glides. TD
24-month-olds and SLI-E 36-month-olds produced approximately the same proportion of syllable types, with the exception of consonant clusters, where TD 24-month-olds produced more than SLI-E 36-month-olds. TD children at 36 months showed the greatest use of syllable shapes containing two different consonants and consonant clusters. Detailed analyses revealed that SLI-E children
produced fewer syllable shapes containing final consonants, more than one consonant type, and consonant clusters. Furthermore, the children with SLI-E were found to vocalize less often than their TD peers. The possible relationships between these findings, SLI-E children’s concomitant
deficits in morphology and syntax, and the implications for diagnosis and remediation are discussed
Loop corrections for Kaluza-Klein AdS amplitudes
Recently we conjectured the four-point amplitude of graviton multiplets in
at one loop by exploiting the operator product
expansion of super Yang-Mills theory. Here we give the first
extension of those results to include Kaluza-Klein modes, obtaining the
amplitude for two graviton multiplets and two states of the first KK mode. Our
method again relies on resolving the large N degeneracy among a family of long
double-trace operators, for which we obtain explicit formulas for the leading
anomalous dimensions. Having constructed the one-loop amplitude we are able to
obtain a formula for the one-loop corrections to the anomalous dimensions of
all twist five double-trace operators.Comment: 37 pages. One ancillary file containing data on the correlator
Association between class III obesity (BMI of 40-59 kg/m2) and mortality: A pooled analysis of 20 prospective studies
Background
The prevalence of class III obesity (body mass index [BMI]≥40 kg/m2) has increased dramatically in several countries and currently affects 6% of adults in the US, with uncertain impact on the risks of illness and death. Using data from a large pooled study, we evaluated the risk of death, overall and due to a wide range of causes, and years of life expectancy lost associated with class III obesity. Methods and Findings
In a pooled analysis of 20 prospective studies from the United States, Sweden, and Australia, we estimated sex- and age-adjusted total and cause-specific mortality rates (deaths per 100,000 persons per year) and multivariable-adjusted hazard ratios for adults, aged 19–83 y at baseline, classified as obese class III (BMI 40.0–59.9 kg/m2) compared with those classified as normal weight (BMI 18.5–24.9 kg/m2). Participants reporting ever smoking cigarettes or a history of chronic disease (heart disease, cancer, stroke, or emphysema) on baseline questionnaires were excluded. Among 9,564 class III obesity participants, mortality rates were 856.0 in men and 663.0 in women during the study period (1976–2009). Among 304,011 normal-weight participants, rates were 346.7 and 280.5 in men and women, respectively. Deaths from heart disease contributed largely to the excess rates in the class III obesity group (rate differences = 238.9 and 132.8 in men and women, respectively), followed by deaths from cancer (rate differences = 36.7 and 62.3 in men and women, respectively) and diabetes (rate differences = 51.2 and 29.2 in men and women, respectively). Within the class III obesity range, multivariable-adjusted hazard ratios for total deaths and deaths due to heart disease, cancer, diabetes, nephritis/nephrotic syndrome/nephrosis, chronic lower respiratory disease, and influenza/pneumonia increased with increasing BMI. Compared with normal-weight BMI, a BMI of 40–44.9, 45–49.9, 50–54.9, and 55–59.9 kg/m2 was associated with an estimated 6.5 (95% CI: 5.7–7.3), 8.9 (95% CI: 7.4–10.4), 9.8 (95% CI: 7.4–12.2), and 13.7 (95% CI: 10.5–16.9) y of life lost. A limitation was that BMI was mainly ascertained by self-report. Conclusions
Class III obesity is associated with substantially elevated rates of total mortality, with most of the excess deaths due to heart disease, cancer, and diabetes, and major reductions in life expectancy compared with normal weight
Structure and function of the regulatory C-terminal HRDC domain from Deinococcus radiodurans RecQ
RecQ helicases are critical for maintaining genome integrity in organisms ranging from bacteria to humans by participating in a complex network of DNA metabolic pathways. Their diverse cellular functions require specialization and coordination of multiple protein domains that integrate catalytic functions with DNA–protein and protein–protein interactions. The RecQ helicase from Deinococcus radiodurans (DrRecQ) is unusual among RecQ family members in that it has evolved to utilize three ‘Helicase and RNaseD C-terminal’ (HRDC) domains to regulate its activity. In this report, we describe the high-resolution structure of the C-terminal-most HRDC domain of DrRecQ. The structure reveals unusual electrostatic surface features that distinguish it from other HRDC domains. Mutation of individual residues in these regions affects the DNA binding affinity of DrRecQ and its ability to unwind a partial duplex DNA substrate. Taken together, the results suggest the unusual electrostatic surface features of the DrRecQ HRDC domain may be important for inter-domain interactions that regulate structure-specific DNA binding and help direct DrRecQ to specific recombination/repair sites
Reproductive Factors and Non-Hodgkin Lymphoma Risk in the California Teachers Study
BACKGROUND:Non-Hodgkin lymphoma (NHL) is a malignancy etiologically linked to immunomodulatory exposures and disorders. Endogenous female sex hormones may modify immune function and influence NHL risk. Few studies have examined associations between reproductive factors, which can serve as surrogates for such hormonal exposures, and NHL risk by subtype. METHODOLOGY/PRINCIPAL FINDINGS:Women in the California Teachers Study cohort provided detailed data in 1995-1996 on reproductive history. Follow-up through 2007 identified 574 women with incident B-cell NHL. Hazard rate ratios (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models to assess associations between reproductive factors and all B-cell NHL combined, diffuse large B-cell lymphomas, follicular lymphomas, and B-cell chronic lymphocytic leukemias/small lymphocytic lymphomas. Pregnancy was marginally associated with lower risk of B-cell NHL (RR = 0.84, 95% CI = 0.68-1.04). Much of the reduction in risk was observed after one full-term pregnancy relative to nulligravid women (RR = 0.75, 95% CI = 0.54-1.06; P for trend <0.01), particularly for diffuse large B-cell lymphomas (P for trend = 0.13), but not among women who had only incomplete pregnancies. Age at first full-term pregnancy was marginally inversely associated with B-cell NHL risk overall (P for trend = 0.08) and for diffuse large B-cell lymphomas (P for trend = 0.056). Breast feeding was not associated with B-cell NHL risk overall or by subtype. CONCLUSIONS:Full-term pregnancy and early age at first full-term pregnancy account for most of the observed reduction in B-cell NHL risk associated with gravidity. Pregnancy-related hormonal exposures, including prolonged and high-level exposure to progesterone during a full-term pregnancy may inhibit development of B-cell NHL
Epidemiologic Evaluation of Measurement Data in the Presence of Detection Limits
Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or interfering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of “fill-in” values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5–10%). The fill-in approach generally produces unbiased parameter estimates but may produce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various approaches using measurements of pesticide residues in carpet dust in control subjects from a case–control study of non-Hodgkin lymphoma
Use of complementary and alternative medicine and breast cancer survival in the Health, Eating, Activity, and Lifestyle Study
PURPOSE:
Use of complementary and alternative medicine (CAM) is common among breast cancer patients, but less is known about whether CAM influences breast cancer survival.
METHODS:
Health Eating, Activity, and Lifestyle (HEAL) Study participants (n = 707) were diagnosed with stage I-IIIA breast cancer. Participants completed a 30-month post-diagnosis interview including questions on CAM use (natural products such as dietary and botanical supplements, alternative health practices, and alternative medical systems), weight, physical activity, and comorbidities. Outcomes were breast cancer-specific and total mortality, which were ascertained from the Surveillance Epidemiology and End Results registries in Western Washington, Los Angeles County, and New Mexico. Cox proportional hazards regression models were fit to data to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for mortality. Models were adjusted for potential confounding by sociodemographic, health, and cancer-related factors.
RESULTS:
Among 707 participants, 70 breast cancer-specific deaths and 149 total deaths were reported. 60.2 % of participants reported CAM use post-diagnosis. The most common CAM were natural products (51 %) including plant-based estrogenic supplements (42 %). Manipulative and body-based practices and alternative medical systems were used by 27 and 13 % of participants, respectively. No associations were observed between CAM use and breast cancer-specific (HR 1.04, 95 % CI 0.61-1.76) or total mortality (HR 0.91, 95 % CI 0.63-1.29).
CONCLUSION:
Complementary and alternative medicine use was not associated with breast cancer-specific mortality or total mortality. Randomized controlled trials may be needed to definitively test whether there is harm or benefit from the types of CAM assessed in HEAL in relation to mortality outcomes in breast cancer survivors
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