108 research outputs found
Quantifying Seasonal-Variation In Somatic Tissue - Surfclam Spisula-Solidissima (Dillwyn, 1817) - A Case-Study
Condition indexes are commonly derived from bivalve species. Usable meat yields (UMY, in l/bu) from 181 daily landings of Atlantic surfclams, Spisula solidissima (Dellwyn, 1817), at a Virginia processing plant in 1974 and 160 landings in 1975 were used as an index in our analysis. The data were fitted to a basic sinusoidal model and a two-compartment sinusoidal model to demonstrate the utility of these models for quantifying cyclic events. The basic model, x = x(0) + A cos2 pi t + B sin2 pi t, is linear in its independent variables and fitted by multiple regression, with x = UMY, 1 = time in years, where x(0), A, and B are constants determined by the regression procedure (x(0) = mean UMY). Its alternate form is x = x(0) + r cos2 pi(t - t(0)), with x, x(0), and t as before, r = amplitude of the sinusoidal variation, and t, = time when the maximal UMY occurs; r and t, are related to A and B as r = root A(2) + B-2, and t(0) = (1/2 pi)tan(-1) (B/A). The sinusoidal fit to the 1974 data was highly significant (p \u3c 0.0005); therefore, the null hypothesis that the data are not a function of time was rejected. The annual mean yield, x(0), was 5.93 l/bu, t(0) was 0.45 (i.e., the maximal UMY occurred about mid-June), and the amplitude r was 0.730; thus, the difference between the lowest and highest yields, 2r, was almost 1.5 l/bu. Similar estimates were determined from the 1975 data and the combined data. The fit was recalculated for both data sets after excluding apparent outliers. As expected, the root-mean-square residual (RMS,,,) decreased, whereas the coefficient of determination (R(2)) increased with the removal of the apparent outliers, but the fitted parameters were inconsequentially affected. A fit of the data to a two-component sinusoidal model, x = x(0) + A(1) cos2 pi t + B-1 sin2 pi t + A(2) cos4 pi t + B-2 sin4 pi t, modeled an annual variation with an asymmetric rise and fall. As a demonstration, the data were also fitted to a parabolic model, x = a, + a(1)t + a(2)t(2). Although this model produced fits comparably as close as the sinusoidal models, the coefficients are not interpretable in a simple manner, as is the case with the sinusoidal fits, and it does not allow asymmetric behavior
Directional and fluctuating asymmetry in finger and a-b ridge counts in psychosis: a case-control study
BACKGROUND: Several studies have reported alterations in finger and a-b ridge counts, and their derived measures of asymmetry, in schizophrenia compared to controls. Because ridges are fully formed by the end of the second trimester, they may provide clues to disturbed early development. The aim of this study was to assess these measures in a sample of patients with psychosis and normal controls. METHODS: Individuals with psychosis (n = 240), and normal controls (n = 228) were drawn from a catchment-area case-control study. Differences in finger and a-b ridge count and Fluctuating Asymmetry were assessed in three group comparisons (non-affective psychosis versus controls; affective psychosis versus controls; non-affective psychosis versus affective psychosis). The analyses were performed separately for males and females. RESULTS: There were no significant group differences for finger nor a-b ridge counts. While there were no group difference for Directional Asymmetry, for Fluctuating Asymmetry measures men with non-affective psychosis had significantly higher fluctuating asymmetry of the index finger ridge count (a) when compared to controls (FA-correlation score, p = 0.02), and (b) when compared to affective psychosis (adjusted FA-difference score, p = 0.04). CONCLUSION: Overall, measures of finger and a-b ridge counts, and their derived measures of directional and fluctuating asymmetry were not prominent features of psychosis in this sample. While directional asymmetry in cerebral morphology is reduced in schizophrenia, this is not reflected in dermatoglyphic variables
Neoadjuvant Chemotherapy with Gemcitabine-Containing Regimens in Patients with Early-Stage Non-small Cell Lung Cancer
BACKGROUND: Surgical resection alone remains suboptimal for patients with early-stage (I or II) non-small cell lung cancer. Two similar randomized phase II trials were conducted to define an active preoperative regimen in this disease state. METHODS: In the first study, patients were randomized to receive gemcitabine 1000 mg/m2 on days 1 and 8 plus cisplatin 80 mg/m2 on day 1 (GC) or gemcitabine 1000 mg/m2 on days 1 and 8 plus carboplatin area under the curve 5.5 on day 1 (GCb). In the second trial, patients received the same regimen of GCb or gemcitabine 1000 mg/m2 on days 1 and 8 plus paclitaxel 200 mg/m2 on day 1 (GP). Cycles were repeated every 21 days for three cycles. The primary end point was pathologic complete response (pCR) rate. RESULTS: Eighty-seven eligible patients were randomized (GC n = 12, GP n = 35, and GCb n = 40), and 71 (82%) underwent surgery after chemotherapy. The confirmed pCR rate was 2.3% (2 of 87, 95% confidence interval 0.3-8.1). Clinical response rate was 28.7%, complete resection rate was 91.5% (65 of 71 patients), and perioperative mortality rate was 2.8%. As of October 2006, median survival for all patients was 45 months (65.5% censored), with 87.2% alive at 1 year and 69.8% alive at 2 years. DISCUSSION: Neoadjuvant chemotherapy with gemcitabine was feasible and well tolerated, and outcomes were similar to other reports of this treatment strategy. However, no regimen achieved the predefined pCR rate that would be sufficient to warrant further evaluation in the phase III setting. This trial design provides an efficient way of providing a rationale for choosing or rejecting regimens of potential value
An enhanced model for digital reference services
Digital Reference Service (DRS) play a vital role in the Digital Library (DL) research.
DRS is a very valuable service provided by DL. Unfortunately, the reference service
movement towards digital environment begins late, and this shift was not model
based. So, a journey towards a digital environment without following a proper model
raises some issues. A few researchers presented a general process model (GPM) in
the late 1990s, but this process model could not overcome the problems of DRS. This
paper proposes an enhanced model for DRS that use the storage and re-use
mechanism with other vital components like DRS search engine and ready reference
for solving the issues in DRS. Initially, storage and re-use mechanism are designed
and finally, DRS search engine is designed to search appropriate answers in the
knowledge base. We improved the GPM by incorporating the new components. The
simulation results clearly states that the proposed model increased the service
efficiency by reducing the response time from days to seconds for repeated questions
and decreased the workload of librarian
Wetland Issues Affecting Waterfowl Conservation in North America
This paper summarises discussions by invited speakers during a special session at the 6th North American Duck Symposium on wetland issues that affect waterfowl, highlighting current ecosystem challenges and opportunities for the conservation of waterfowl in North America. Climate change, invasive species, U.S. agricultural policy (which can encourage wetland drainage and the expansion of row-crop agriculture into grasslands), cost and competition for water rights, and wetland management for non-waterfowl species were all considered to pose significant threats to waterfowl populations in the near future. Waterfowl populations were found to be faced with significant threats in several regions, including: the Central Valley of California, the
Playa Lakes Region of the south-central U.S., the Prairie Pothole Region of the northern U.S. and western and central Canada, the boreal forest of northern Canada, the Great Lakes region and Latin America. Apart from direct and indirect threats to habitat, presenters identified that accurate and current data on the location, distribution and diversity of wetlands are needed by waterfowl managers, environmental planners and regulatory agencies to ensure focused, targeted and cost-effective wetland conservation. Although populations of many waterfowl species are currently at or above long-term average numbers, these populations are thought to be at risk of decline in the near future because of ongoing and predicted nesting habitat loss and wetland destruction in many areas of North America
A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome
Intelligence testing in children with intellectual disabilities (ID) has significant limitations. The normative samples of widely used intelligence tests, such as the Wechsler Intelligence Scales, rarely include an adequate number of subjects with ID needed to provide sensitive measurement in the very low ability range, and they are highly subject to floor effects. The IQ measurement problems in these children prevent characterization of strengths and weaknesses, poorer estimates of cognitive abilities in research applications, and in clinical settings, limited utility for assessment, prognosis estimation, and planning intervention. Here, we examined the sensitivity of the Wechsler Intelligence Scale for Children (WISC-III) in a large sample of children with fragile X syndrome (FXS), the most common cause of inherited ID. The WISC-III was administered to 217 children with FXS (age 6–17 years, 83 girls and 134 boys). Using raw norms data obtained with permission from the Psychological Corporation, we calculated normalized scores representing each participant’s actual deviation from the standardization sample using a z-score transformation. To validate this approach, we compared correlations between the new normalized scores versus the usual standard scores with a measure of adaptive behavior (Vineland Adaptive Behavior Scales) and with a genetic measure specific to FXS (FMR1 protein or FMRP). The distribution of WISC-III standard scores showed significant skewing with floor effects in a high proportion of participants, especially males (64.9%–94.0% across subtests). With the z-score normalization, the flooring problems were eliminated and scores were normally distributed. Furthermore, we found correlations between cognitive performance and adaptive behavior, and between cognition and FMRP that were very much improved when using these normalized scores in contrast to the usual standardized scores. The results of this study show that meaningful variation in intellectual ability in children with FXS, and probably other populations of children with neurodevelopmental disorders, is obscured by the usual translation of raw scores into standardized scores. A method of raw score transformation may improve the characterization of cognitive functioning in ID populations, especially for research applications
The Spectrum of Neurological and White Matter Changes and Premutation Status Categories of Older Male Carriers of the FMR1 Alleles Are Linked to Genetic (CGG and FMR1 mRNA) and Cellular Stress (AMPK) Markers
The fragile X premutation (PM) allele contains a CGG expansion of 55–200 repeats in the FMR1 gene’s promoter. Male PM carriers have an elevated risk of developing neurological and psychiatric changes, including an approximately 50% risk of the fragile X-associated tremor/ataxia syndrome (FXTAS). The aim of this study was to assess the relationships of regional white matter hyperintensities (wmhs) semi-quantitative scores, clinical status, motor (UPDRS, ICARS, Tremor) scales, and cognitive impairments, with FMR1-specific genetic changes, in a sample of 32 unselected male PM carriers aged 39–81 years. Half of these individuals were affected with FXTAS, while the non-FXTAS group comprised subcategories of non-affected individuals and individuals affected with non-syndromic changes. The dynamics of pathological processes at the cellular level relevant to the clinical status of PM carriers was investigated using the enzyme AMP-activated protein kinase (AMPK), which is a highly sensitive cellular stress-sensing alarm protein. This enzyme, as well as genetic markers – CGG repeat number and the levels of the FMR1 mRNA – were assessed in blood lymphoblasts. The results showed that the repeat distribution for FXTAS individuals peaked at 85–90 CGGs; non-FXTAS carriers were distributed within the lowest end of the PM repeat range, and non-syndromic carriers assumed an intermediate position. The size of the CGG expansion was significantly correlated, across all three categories, with infratentorial and total wmhs and with all motor scores, and the FMR1 mRNA levels with all the wmh scores, whilst AMPK activity showed considerable elevation in the non-FXTAS combined group, decreasing in the FXTAS group, proportionally to increasing severity of the wmhs and tremor/ataxia. We conclude that the size of the CGG expansion relates to the risk for FXTAS, to severity of infratentorial wmhs lesions, and to all three motor scale scores. FMR1 mRNA shows a strong association with the extent of wmhs, which is the most sensitive marker of the pathological process. However, the AMPK activity findings – suggestive of a role of this enzyme in the risk of FXTAS – need to be verified and expanded in future studies using larger samples and longitudinal assessment
Limb development genes underlie variation in human fingerprint patterns
Fingerprints are of long-standing practical and cultural interest, but little is known about the mechanisms that underlie their variation. Using genome-wide scans in Han Chinese cohorts, we identified 18 loci associated with fingerprint type across the digits, including a genetic basis for the long-recognized “pattern-block” correlations among the middle three digits. In particular, we identified a variant near EVI1 that alters regulatory activity and established a role for EVI1 in dermatoglyph patterning in mice. Dynamic EVI1 expression during human development supports its role in shaping the limbs and digits, rather than influencing skin patterning directly. Trans-ethnic meta-analysis identified 43 fingerprint-associated loci, with nearby genes being strongly enriched for general limb development pathways. We also found that fingerprint patterns were genetically correlated with hand proportions. Taken together, these findings support the key role of limb development genes in influencing the outcome of fingerprint patterning
Autoimmune disease in mothers with the FMR1 premutation is associated with seizures in their children with fragile X syndrome
An increased prevalence of autoimmune diseases in family members of children with autism spectrum disorders (ASD) has been previously reported. ASD is also a common problem co-occurring in children with fragile X syndrome (FXS). Why ASD occurs in some individuals with FXS, but not all, is largely unknown. Furthermore, in premutation carrier mothers, there is an increased risk for autoimmune diseases. This study compared the rate of ASD and other neurodevelopmental/behavioral problems in 61 children with FXS born to 41 carrier mothers who had autoimmune disease and in 97 children with FXS of 78 carrier mothers who did not have autoimmune disease. There were no significant differences in the mean age (9.61 ± 5.59 vs. 9.41 ± 6.31, P = 0.836), cognitive and adaptive functioning in children of mothers with and without autoimmune disease. Among children whose mothers had autoimmune disease, the odds ratio (OR) for ASD was 1.27 (95% CI 0.62–2.61, P = 0.5115). Interestingly, the OR for seizures and tics was 3.81 (95% CI 1.13–12.86, P = 0.031) and 2.94 (95% CI 1.19–7.24, P = 0.019), respectively, in children of mothers with autoimmune disease compared to children of mothers without autoimmune disease. In conclusion, autoimmune disease in carrier mothers was not associated with the presence of ASD in their children. However, seizures and tics were significantly increased in children of mothers with autoimmune disease. This suggests a potential new mechanism of seizure and tic exacerbation in FXS related to an intergenerational influence from autoimmunity in the carrier mother
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