241 research outputs found

    EVALUATION OF METHANE GAS PRODUCTION IN A SIMULTANEOUS REGRESSION SYSTEM

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    Methane gas production is a function of volatile solids activity in anaerobic digesters. Increasing the solids retention time of the swine manure digester system without increasing the hydraulic retention time would theoretically increase the methane gas production efficiency. Coagulation treatments were performed on the effluent of the second digester in a system of two digesters in series . The objective of this paper is to describe mathematically the relationship of the Coagulation treatments in the second digester to biogas production and volatile solids retention. An initial, single equation, ordinary least squares regression produced statistically significant parameter estimates, but failed to accurately describe the treatment activity occurring in the second digester. To assess the treatment activity of the second digester and account for the activity of first digester on the second, data was regressed through a simultaneous equation system. Both two-stage and three-stage least squares regression were examined

    APPLYING PRINCIPAL COMPONENT ANALYSIS TO SOIL-LANDSCAPE RESEARCH-QUANTIFYING THE SUBJECTIVE

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    Principal component analysis is a multivariate statistical procedure that can be used to identify factors (correlated subsets of variables) in large data sets. This statistical method appears useful for scientists investigating soil processes, but it has received little attention. Reported applications of principal component analysis share a common fault--subjective, user-specified analytical options apparently are not recognized, for they are not discussed. Reported data sets are often small, have low observations-per-variable ratios, and lack tests of robustness. A large soil data set is used to demonstrate systematic procedures for an optimum rotated principal component solution. This solution retained 21 variables aligned among four clean and logical factors, and extracted 79% of the variance. Robustness was confirmed by comparison with common factor analysis solutions. When carefully applied, the presented guidelines should enhance scientists\u27 abilities to identify and transfer knowledge about multivariate data sets, and should allow different scientists to independently arrive at similar factor solutions

    CONFIDENCE INTERVALS FOR SOIL PROPERTIES BASED ON DIFFERING STATISTICAL ASSUMPTIONS

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    Agricultural soil management is becoming increasingly precise as technology advances and as environmental concerns increase. Soil surveys are a readily available source of soils information, but soil properties are reported as generalized values or generic ranges. A need exists to define the central tendencies of soil properties in a rigorous, quantified fashion. Statistically, the central tendency is best expressed as confidence intervals about means or medians. Transect sampling was used to collect data on soil properties within a soil survey map unit. Key questions for data analysis include assumptions of independence within transects and normality. The choice of statistical method is based on assumptions about the data and on the sampling scheme. Narrower confidence intervals resulted from assumptions of independence within transects and normal distributions of soil property values. Wider confidence intervals were obtained if assumptions of independence and normality were not made. For transect sampling in general, and these data in particular, the wider confidence intervals seem most appropriate

    MULTIPLE REGRESSION ANALYSIS OF SOIL PROPERTIES ON ERODED AND NATIVE DEEP LOESS MISSOURI SOILS

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    Researchers have described the difficulty of studying the effects of cultivation on soil properties unless native (uncultivated) areas can be used as a baseline for comparison. Even when suitable areas are located the problems of quantifying and comparing the horizontal and vertical distributions of soil properties remain. Areal distributions of soil surface, subsurface, and upper subsoil properties were compared in cultivated and forested deep loess soils on similar geomorphic surfaces and hillslope positions in two counties adjacent to the Missouri River. A 3-dimensional grid was used to sample selected soils from the summit to the lower backs lope on 3 forested and 3 cultivated hillslopes . Multiple regress ion analysis revealed that a second order response surface equation adequately modeled the depths to maximum clay percentage and thickness of A horizon and a third-order response surface adequately modeled thickness of the subsurface horizon and depth to top of B horizon, based on the independent variables percent slope, distance from hillslope summit, and site management. Further analysis showed that each site had a significantly different response surface which could be related to site characteristics and current cover (forest or cultivation). The use of analysis of variance within multiple regression allowed for the systematic description and comparison of soil properties on forested and cultivated sites, and for the determination of the relationship between the selected soil properties and slope and site characteristics

    Germline EMSY sequence alterations in hereditary breast cancer and ovarian cancer families

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    Background: BRCA1 and BRCA2 mutations explain approximately one-fifth of the inherited susceptibility in high-risk Finnish hereditary breast and ovarian cancer (HBOC) families. EMSY is located in the breast cancer-associated chromosomal region 11q13. The EMSY gene encodes a BRCA2-interacting protein that has been implicated in DNA damage repair and genomic instability. We analysed the role of germline EMSY variation in breast/ovarian cancer predisposition. The present study describes the first EMSY screening in patients with high familial risk for this disease.Methods: Index individuals from 71 high-risk, BRCA1/2-negative HBOC families were screened for germline EMSY sequence alterations in protein coding regions and exon-intron boundaries using Sanger sequencing and TaqMan assays. The identified variants were further screened in 36 Finnish HBOC patients and 904 controls. Moreover, one novel intronic deletion was screened in a cohort of 404 breast cancer patients unselected for family history. Haplotype block structure and the association of haplotypes with breast/ovarian cancer were analysed using Haploview. The functionality of the identified variants was predicted using Haploreg, RegulomeDB, Human Splicing Finder, and Pathogenic-or-Not-Pipeline 2.Results: Altogether, 12 germline EMSY variants were observed. Two alterations were located in the coding region, five alterations were intronic, and five alterations were located in the 3'untranslated region (UTR). Variant frequencies did not significantly differ between cases and controls. The novel variant, c.2709 + 122delT, was detected in 1 out of 107 (0.9%) breast cancer patients, and the carrier showed a bilateral form of the disease. The deletion was absent in 897 controls (OR = 25.28; P = 0.1) and in 404 breast cancer patients unselected for family history. No haplotype was identified to increase the risk of breast/ovarian cancer. Functional analyses suggested that variants, particularly in the 3'UTR, were located within regulatory elements. The novel deletion was predicted to affect splicing regulatory elements.Conclusions: These results suggest that the identified EMSY variants are likely neutral at the population level. However, these variants may contribute to breast/ovarian cancer risk in single families. Additional analyses are warranted for rare novel intronic deletions and the 3'UTR variants predicted to have functional roles

    Outcome of Chair-Side Dental Fear Treatment: Long-Term Follow-Up in Public Health Setting

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    Aim. Purpose of this practice and data-based study was to evaluate the outcome of dental fear treatment of patients referred to the Clinic for Fearful Dental Patients (CFDP) in the primary oral health care, City of Oulu, Finland, during period 2000-2005. Methods. A psychological approach including behavioral interventions and cognitive behavioral therapy (BT/CBT) was used for all participants combined with conscious sedation or dental general anesthesia (DGA), if needed. The outcome was considered successful if later dental visits were carried out without any notifications in the patient records of behavioral problems or sedation. Data collection was made in 2006; the average length of the observation period from the last visit in the CFPD to data collection was 2y 3m (SD 1y 5m). All information was available for 163 patients (mean age 8.9y at referral). Study population was dominated by males (58.0%). Cause for referrals was mostly dental fear (81.0%) or lack of cooperation. Results. The success rate was 69.6% among females and 68.1% among males. Success seemed to be (p=0.053) higher for those treated in 12years compared with the older ones. The participants, without need for dental general anesthesia (DGA) in the CFDP, had significantly a higher success rate (81.4%) compared with those who did (54.8%, p<0.001). Use of conscious oral sedation (p=0.300) or N2O (p=0.585) was not associated with the future success. Conclusions. A chair-side approach seems successful in a primary health care setting for treating dental fear, especially in early childhood. Use of sedation seems not to improve the success rate

    The charging of neutral dimethylamine and dimethylamine-sulfuric acid clusters using protonated acetone

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    Sulfuric acid is generally considered one of the most important substances taking part in atmospheric particle formation. However, in typical atmospheric conditions in the lower troposphere, sulfuric acid and water alone are unable to form particles. It has been suggested that strong bases may stabilize sulfuric acid clusters so that particle formation may occur. More to the point, amines - strong organic bases - have become the subject of interest as possible cause for such stabilization. To probe whether amines play a role in atmospheric nucleation, we need to be able to measure accurately the gas-phase amine vapour concentration. Such measurements often include charging the neutral molecules and molecular clusters in the sample. Since amines are bases, the charging process should introduce a positive charge. This can be achieved by, for example, using chemical ionization with a positively charged reagent with a suitable proton affinity. In our study, we have used quantum chemical methods combined with a cluster dynamics code to study the use of acetone as a reagent ion in chemical ionization and compared the results with measurements performed with a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF). The computational results indicate that protonated acetone is an effective reagent in chemical ionization. However, in the experiments the reagent ions were not depleted at the predicted dimethylamine concentrations, indicating that either the modelling scheme or the experimental results - or both - contain unidentified sources of error.Peer reviewe

    Effect of alloy treatment and coiling temperature on microstructure and bending performance of ultra-high strength strip steel

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    Two different high strength B-containing microalloyed steel strips produced in industrial processing conditions, one treated with Ti and the other treated with Al, processed by controlled rolling, accelerated cooling and coiling in two different temperatures ranges [723 K to 733 K (450 °C to 460 °C)] and [633 K to 653 K (360 °C to 380 °C)] were subjected to bend testing. The Ti treated steel coiled at the higher temperature 733 K (460 °C) showed the best bending performance. The relatively softer (tensile strength of and even {112} in the sub-surface region as well as uniformity of through thickness texture of the rolled sheet improve the bendability. In the presence of crack initiators, like coarse and brittle TiN particles found in the Ti treated steel, a harder microstructure and the presence of Cube and Goss texture in the sub-surface layer, seen for the lower coiling temperature can cause local transgranular cleavage cracking. Finally the post-uniform elongation obtained from tensile testing and bendability follow a good correlation

    Lack of relationship between TIMP-1 tumour cell immunoreactivity, treatment efficacy and prognosis in patients with advanced epithelial ovarian cancer

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    <p>Abstract</p> <p>Background</p> <p>Tissue inhibitor of metalloproteinase 1 (TIMP-1) is a natural inhibitor of the matrix metalloproteinases (MMPs) which are proteolytic enzymes involved in degradation of extracellular matrix thereby favoring tumour cell invasion and metastasis. TIMP-1 activity in tumour tissue may therefore play an essential role in the progression of a malignant tumour.</p> <p>The primary aim of the present study was to evaluate TIMP-1 protein immunoreactivity in tissue from primary ovarian cancer patients and associate these findings with the course of the disease including response to treatment in the individual patient.</p> <p>Methods</p> <p>TIMP-1 was assessed by immunohistochemistry (in tissue micro arrays) in a total of 163 ovarian cancer specimens obtained from primary debulking surgery during 1991-1994 as part of a randomized clinical protocol.</p> <p>Results</p> <p>Positive TIMP-1 immunoreactivity was found in 12.3% of the tumours. The median survival time for the 143 patients with TIMP-1 negative tumours was 23.7 months [19.0-29.4] 95% CI, while the median survival time for the 20 patients with TIMP-1 positive tumours was 15.9 months [12.3-27.4] 95% CI. Although a difference of 7.8 months in median overall survival in favor of the TIMP-1 tumour negative patients was found, this difference did not reach statistical significance (<it>p </it>= 0.28, Kaplan-Meier, log-rank test). Moreover, TIMP-1 immunoreactivity was not associated with CA125 response (p = 0.53) or response at second look surgery (p = 0.72).</p> <p>Conclusion</p> <p>TIMP-1 immunoreactivity in tumour tissue from patients with primary epithelial ovarian cancer did not correlate with patient survival or response to combination platinum/cyclophosphamide therapy.</p
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