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1.
Sergey N. Kolomeichuk Christoph Randler Alexey Churov Mikhail Borisenkov 《Biological Rhythm Research》2015,46(5):725-737
Morningness–eveningness preference is commonly measured by questionnaires, such as the Composite Scale of Morningness (CSM). Purpose of our study was to assess the Russian translation of the CSM and provide psychometric properties of this scale. Participants (N = 406) were students from high schools and university in Petrozavodsk. Mean age was 20.47 ± 3.66 with a range of 12–38 years. Mean CSM scores were 31.43 ± 6.32, with a range from 14 to 50. Internal reliability, as measured by Cronbach’s α, was 0.823. There was no negative correlation among the items. The reliability of 0.82 is good and fits into previous work done with the CSM in many different countries. The factor structure appears as a two-factor structure based on parallel analysis and a three-factor structure based on the eigenvalue greater than one criterion. We suggest retaining the two-factor structure, one factor could be labelled as morning affect and the other one as self-assessment/activity planning. Construct validity was checked with the MCTQ and showed that the correlations between midpoint of sleep and CSM are comparable to other studies. 相似文献
2.
Estimates of life‐history parameters were made for shark‐like batoids of conservation concern Rhynchobatus spp. (Rhynchobatus australiae, Rhynchobatus laevis and Rhynchobatus palpebratus) and Glaucostegus typus using vertebral ageing. The sigmoid growth functions, Gompertz and logistic, best described the growth of Rhynchobatus spp. and G. typus, providing the best statistical fit and most biologically appropriate parameters. The two‐parameter logistic was the preferred model for Rhynchobatus spp. with growth parameter estimates (both sexes combined) L∞ = 2045 mm stretch total length, LST and k = 0·41 year?1. The same model was also preferred for G. typus with growth parameter estimates (both sexes combined) L∞ = 2770 mm LST and k = 0·30 year?1. Annual growth‐band deposition could not be excluded in Rhynchobatus spp. using mark‐recaptured individuals. Although morphologically similar G. typus and Rhynchobatus spp. have differing life histories, with G. typus longer lived, slower growing and attaining a larger maximum size. 相似文献
3.
Diesfeldt HF 《Tijdschrift voor gerontologie en geriatrie》2004,35(6):224-233
The Depression List is a Dutch self-report measure of depressive symptoms in persons with dementia. Fifteen items differ to the extent that they provide reliable measurements of latent constructs such as feeling depressed, tired or lonely. Item scalability and construct reliability were studied by administering the questionnaire to 599 consecutive visitors of a psychogeriatric day care department. Using confirmatory factor analysis three competing hypothetical models were tested for model fit. A four-factor model composed of latent constructs for feeling depressed, tired, lonesome and appetite or sleep disturbance provided an adequate fit to the clinical data, which did not apply to a two-factor model (distinguishing a construct of loneliness from a more general mood construct) and a one-factor model, that hypothesized a single general mood construct for all fifteen items. Nine items carried relatively small proportions of error variance. These reliable items were selected for the construction of three scales that satisfied the assumptions of Mokken's criteria for homogeneity. The resulting measures of feeling depressed, tired or lonely showed evidence of convergent validity for a latent affective construct. The affective measures were not associated with severity of cognitive impairment (discriminant validity). The three scales allow a reliable measurement of differences in affective function in cognitively impaired subjects. 相似文献
4.
How alike are the shapes of two random chains? 总被引:1,自引:0,他引:1
A D McLachlan 《Biopolymers》1984,23(7):1325-1331
Two completely flexible random chains containing N atoms joined by links of length L can be superimposed by rigid-body motions to match their structures as closely as possible. The statistics of the root-mean-square best-fit distance D are discussed. For long chains, D2 tends of 0.125L2N. Thus, for a protein of 100 residues, where the Cα-Cα distance is L = 3.8 Å, the expected root-mean-square atomic distance is 13.4 Å. This result gives a surprisingly good fit to the observed results for unrelated structures. 相似文献
5.
Ashish A. Prabhu 《Preparative biochemistry & biotechnology》2017,47(10):953-962
Pichia pastoris is considered as one of the prominent host extensively used as a platform for heterologous protein production. In the present study, the growth inhibition kinetics of recombinant P. pastoris expressing human interferon gamma was studied under different initial substrate concentrations of gluconate (10–100?g?L?1) and methanol (2–50?g?L?1) in modified FM22 medium. The highest specific growth rate of 0.0206 and 0.019?hr?1 was observed at 60?g?L?1 of gluconate and 10?g?L?1 of methanol, respectively. Various three- and four-parametric Monod-variant models were chosen to analyze the inhibition kinetics. The model parameters as well as goodness of fit were estimated using nonlinear regression analysis. The three-parameter Haldane model was found to be best fit for both gluconate (R2?=?0.95) and methanol substrate (R2?=?0.96). The parameter sensitivity analysis revealed that µmax, Ki, and Ks are the most sensitive parameters for both methanol and gluconate. Different substrate inhibition models were fitted to the growth kinetic data and the additive form of double Webb model was found to be the best to explain the growth kinetics of recombinant P. pastoris. 相似文献
6.
Md. Dilshad Manzar Wassilatul Zannat Jamal Ali Moiz David Warren Spence Seithikurippu R. Pandi-Perumal Ahmed S. Bahammam 《Biological Rhythm Research》2016,47(6):851-864
The Pittsburgh Sleep Quality Index (PSQI) is a rigorously validated questionnaire with extensive use in sleep assessment. Findings from numerous factor analytic studies of the PSQI have been interpreted to support a heterogeneous factor structure model for the test. Nevertheless, the literature continues to lack a focused evaluation of whether this heterogeneous factor structure is justified. A consideration of this issue led to a conclusion that a closer analysis of the PSQI’s factor structure was merited. To address this need a comparative confirmatory factor analysis for assessing the performance of the accepted factors models of the PSQI was conducted. A sample of university students (n = 418), age = 20.92 ± 1.81 years, BMI = 23.30 ± 2.57 kg/m2 completed the multi-structured sleep survey at Jamia Millia Islamia, New Delhi, India. Seventeen putative factor structures (three 1-Factor, eight 2-Factor, and six 3-Factor) of the PSQI from the existing literature were selected for analysis. Fourteen models (82.35%) had almost similar values for model fit indices. Two models were misfits, and one model was a poor fit. The two misfit models incorporated gender and age as covariates. The third poor fit model was used to produce a unique path diagram, which made it distinct from the remaining 16 models. The overlapping values in the fit range of the model fit indices did not support the often projected heterogeneous factor structures of the PSQI for the vast majority of the models. 相似文献
7.
Age and growth of the sandbar shark, Carcharhinus plumbeus, in Hawaiian waters through vertebral analysis 总被引:1,自引:0,他引:1
Age and growth estimates were determined for the sandbar shark, Carcharhinus plumbeus, from Oahu, Hawaii in the central Pacific Ocean. Age estimates were obtained through vertebral centra analysis of 187 sharks. We verified our age estimates through marginal increment analysis of centra and oxytetracycline marking methods of at liberty sandbar sharks. Sizes of sampled sharks ranged from 46 to 147 cm pre-caudal length. Four growth models were fitted to length-at-age data; two forms of the von Bertalanffy growth model, the Gompertz growth model, and a logistic growth model. Males and females exhibited statistically significant differences in growth, indicating that females grow slower and attain larger sizes than males. Growth parameter estimates revealed slower growth rates than previously estimated (based on captive specimens) for Hawaiian sandbar sharks. The von Bertalanffy growth model using empirical length-at-birth provided the best biological and statistical fit to the data. This model gave parameter estimates of L
∞
= 138.5 cm PCL and k = 0.12 year−1 for males and L
∞
= 152.8 cm PCL, k = 0.10 year−1 for females. Male and female sandbar sharks mature at approximately 8 and 10 years of age, respectively. 相似文献
8.
Background
Given the immense burden of HIV/AIDS on health systems in sub-Saharan Africa and the intricate link between HIV/AIDS and mental health problems, health care providers need a valid and reliable instrument to assess mental health rapidly. The Hospital Anxiety and Depression Scale (HADS) may constitute such an instrument. The aims of this study were to: (1) examine the factor structure of the HADS in a population of South African HIV/AIDS patients on antiretroviral treatment (ART); and (2) identify and control the disturbing influence of systematic wording effects in vulnerable respondent groups.Methodology/Principal Findings
The translated scale was administered to 716 HIV/AIDS patients enrolled in the public sector ART program in South Africa. A combined confirmatory factor analysis and correlated-traits-correlated-methods framework was used to determine the preferred factor structure of the HADS, while controlling for the disturbing influence of systematic wording effects. When assessing the structure without a negative wording factor, all three factor structures displayed an acceptable fit to the data. The three-factor solution best fitted the data. Addition of a method factor significantly improved the fit of all three factor solutions. Using χ2 difference testing, Razavi''s one-factor solution displayed a superior fit compared to the other two factor solutions.Conclusions
The study outcomes support the use of the HADS as a valid and reliable means to screen for mental health problems in HIV/AIDS patients enrolled in a public-sector ART program in a resource-limited context. The results demonstrate the importance of evaluating and correcting for wording effects when examining the factor structure of the screening instrument in vulnerable patient groups. In light of the inter-relationships between HIV/AIDS and mental health problems and the scarcity of adequate screening tools, additional studies on this topic are required. 相似文献9.
Population biology and assessment of the white-spotted spinefoot, Siganus canaliculatus (Park, 1797), in the southern Arabian Gulf 总被引:1,自引:0,他引:1
E. Grandcourt T. Al Abdessalaam F. Francis A. Al Shamsi 《Zeitschrift fur angewandte Ichthyologie》2007,23(1):53-59
The age, growth, mortality, reproduction and resource status of Siganus canaliculatus in the southern Arabian Gulf were investigated using a combination of size frequency, biological and size‐at‐age data. Defined structural increments consisting of alternating translucent and opaque bands in transverse sections of sagittal otoliths were validated as annuli. The maximum absolute age estimate was 7.8 years. Parameter values of the von Bertalanffy growth function fit to size‐at‐age data (males and females combined) were: k = 1.0, L∞ = 24.8 cm (LF), to = −0.1 years. Fish in spawning condition were only observed between April and July although patterns in gonadosomatic indices suggested a second but less well defined spawning event in November. The mean sizes and ages at first sexual maturity were 21.5 cm LF (1.9 years) for males and 25.7 cm LF (2.1 years) for females. Fish were fully recruited to the fishery at a size (L100 = 19.7 cm LF) that was smaller than the sizes at which sexual maturity was attained. The annual instantaneous rate of fishing mortality (F = 0.85 year−1) (0.26–1.44 year−1 95% CI) was considerably greater than the target (Fopt = 0.33 year−1) and limit (Flimit = 0.44 year−1) biological reference points, indicating that the stock is overexploited. 相似文献
10.
Seasonal variations in Fulton’s condition factor (K) and the length–weight relationship (LWR) were investigated for Capoeta sieboldii in the upper Çoruh River (Turkey) from March 2000 to February 2001. There was a slight seasonal variation in condition, with generally lower values in summer and winter, and higher values in autumn. LWR was calculated as W = 0.016 × L2.933, W = 0.014 ×L3.001, and W = 0.009 × L3.118 for males, females, and juveniles, respectively. 相似文献
11.
Factors affecting estimates of size at age and growth in grey triggerfish Balistes capriscus from the northern Gulf of Mexico
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R. J. Allman W. F. Patterson III C. L. Fioramonti A. E. Pacicco 《Journal of fish biology》2018,92(2):386-398
Growth zones in dorsal spines of grey triggerfish Balistes capriscus from the northern Gulf of Mexico were utilized to estimate growth and examine factors that may affect estimates of size at age. Age was estimated from dorsal‐spine sections of 4687 individuals sampled from U.S. waters during 2003–2013, including both fishery‐independent (n = 1312) and fishery‐dependent (n = 3375) samples. Ninety‐six per cent (n = 4498) of these sections were deemed suitable for ageing; average per cent error between two independent readers was 10·8%. Fork length (LF) ranged from 65 to 697 mm and age estimates from 0 to 14 years. Both sex and sample source (fishery‐independent v. recreational) significantly affected estimated size at age for 2–6 year‐old fish. Data were pooled between sources to fit sex‐specific von Bertalanffy growth functions. Results for the female model were L∞ = 387 mm LF, k = 0·52 year?1 and t0 = 0·01 year, while for males L∞ = 405 mm LF, k = 0·55 year?1 and t0 = 0·02 year. These results were significantly different between sexes and indicate clear sexual dimorphism. Thus, growth should be modelled separately by sex when examining population parameters or conducting stock assessment modelling. The positive bias in estimates of size at age computed for recreational v. fishery‐independent samples also has clear implications for stock assessment as growth functions computed with fishery‐dependent samples would tend to overestimate stock productivity. 相似文献
12.
Calculating growth parameters of Genidens barbus (Siluriformes, Ariidae) using length composition and age data 总被引:1,自引:0,他引:1
The marine catfish Genidens barbus was once one of the most important estuarine fishery resources in the Patos Lagoon (southern Brazil), which had the largest population known for the species. However, clear signs of overfishing have been observed since the 1980s. Growth parameters for this population were estimated by combining length frequency data for juveniles and selected published data on annuli reading from adult otoliths. This methodology yielded a more realistic set of parameters using both the specialized and generalized von Bertalanffy growth model. The species growth can be described as: Lt = 118.6[1 − e−0.043(t+1.505)] or Lt = 104.6[1 −e−0.137D(t+4.013)]1/D with the surface factor D = 0.542. The growth performance index ϕ′ was estimated as 2.78 for the special (classical) model. Stock rebuilding is expected to be slow, as the species is slow‐growing, has a low natural mortality rate, and mouthbreeds a small amount of large eggs. 相似文献
13.
Background
The Chinese version of the Activities of Daily Living Rating Scale III (ADLRS-III), which has 10 domains, is commonly used for assessing activities of daily living (ADL) in patients with schizophrenia. However, construct validity (i.e., unidimensionality) for each domain of the ADLRS-III is unknown, limiting the explanations of the test results.Purpose
This main purpose of this study was to examine unidimensionality of each domain in the ADLRS-III. We also examined internal consistency and ceiling/floor effects in patients with schizophrenia.Methods
From occupational therapy records, we obtained 304 self-report data of the ADLRS-III. Confirmatory factor analysis (CFA) was conducted to examine the 10 one-factor structures. If a domain showed an insufficient model fit, exploratory factor analysis (EFA) was performed to investigate the factor structure and choose one factor representing the original construct. Internal consistency was examined using Cronbach’s alpha (α). Ceiling and floor effects were determined by the percentage of patients with the maximum and minimum scores in each domain, respectively.Results
CFA analyses showed that 4 domains (i.e., leisure, picture recognition, literacy ability, communication tools use) had sufficient model fits. These 4 domains had acceptable internal consistency (α = 0.79-0.87) and no ceiling/floor effects, except the leisure domain which had a ceiling effect. The other 6 domains showed insufficient model fits. The EFA results showed that these 6 domains were two-factor structures.Conclusion
The results supported unidimensional constructs of the leisure, picture recognition, literacy ability, and communication tool uses domains. The sum scores of these 4 domains can be used to represent their respective domain-specific functions. Regarding the 6 domains with insufficient model fits, we have explained the two factors of each domain and chosen one factor to represent its original construct. Future users may use the items from the chosen factors to assess domain-specific functions in patients with schizophrenia. 相似文献14.
Nuri Başusta Asiye Başusta Eyüp Mümtaz Tıraşın James A. Sulikowski 《Zeitschrift fur angewandte Ichthyologie》2020,36(6):880-887
Between September 2010 and June 2012, a total 291 (166 females and 125 males) blackchin guitarfish Glaucostegus cemiculus were captured by a commercial bottom trawler (F/V Coşkun Reis) in Iskenderun Bay, Turkey (northeastern Mediterranean Sea). The total length (L) and total weight (W) of the female and male guitarfish ranged between 32.0–165.0 cm and 88 g–16.68 kg, and 34.3–128.3 cm and 112 g–6.00 kg, respectively. Vertebral age estimates ranged from 0 to 8 years for females and 0 to 5 years for males. The growth models of von Bertanlanffy and Gompertz were fitted to the length at age data using the nonlinear regression method. Model selection was based on the values of the residual standard error and the Akaike's information criterion corrected for small sample size (AICC) associated with each fit. The von Bertalanffy growth model provided the best fitting growth curves for each sex with parameters reaching L∞ = 187.17 cm, K = 0.195 year-1, t0 = −1.38 year for females, and L∞ = 144.85 cm, K = 0.321 year-1, t0 = −1.13 year-1 for males. The W–L relationship parameters did not differ significantly between sexes, the estimated values of a and b were 0.0018 and 3.11, respectively. By using these values of a and b, and also respective estimates of L∞, the values of W∞ were obtained as 20.53 kg for females and 9.25 kg for males. The overall percentage ratios of females and males in the samples were 57% and 43% respectively. 相似文献
15.
16.
Dimitris Kardassis Ludger Grote Lars Sjöström Jan Hedner Kristjan Karason 《Obesity (Silver Spring, Md.)》2013,21(4):698-704
Objective:
Obesity is frequently associated with obstructive sleep apnea (OSA). Both conditions are proinflammatory and proposed to deteriorate cardiac function. We used a nested cohort study design to evaluate the long‐term impact of bariatric surgery on OSA and how weight loss and OSA relate to inflammation and cardiac performance.Design and Methods:
At 10‐year follow‐up in the Swedish Obese Subjects (SOS) study, we identified 19 obese subjects (BMI 31.2 ± 5.3 kg m?2), who following bariatric surgery at SOS‐baseline had displayed sustained weight losses (surgery group), and 20 obese controls (BMI 42.0 ± 6.2 kg m?2), who during the same time‐period had maintained stable weight (control group). All study participants underwent overnight polysomnography examination, echocardiography and analysis of inflammatory markers.Results:
The surgery group displayed a lower apnea hypopnea index (AHI) (19.9 ± 21.5 vs. 37.8 ± 27.7 n/h, P = 0.013), lower inflammatory activity (hsCRP 2.3 ± 3.0 vs. 7.2 ± 5.0 mg L?1, P < 0.001), reduced left ventricular mass (165 ± 22 vs. 207 ± 22 g, P < 0.001) and superior left ventricular diastolic function (E/A ratio 1.24 ± 1.10 vs. 1.05 ± 0.20, P = 0.006) as compared with weight stable obese controls. In multiple regression analyses including all subjects (n = 39) and controlling for BMI, the AHI remained independently associated with hsCRP (β = 0.09, P < 0.001), TNF‐α (β = 0.03, P = 0.031), IL‐6 (β = 0.01, P = 0.007), IL 10 (β = ?0.06; P = 0.018), left ventricular mass (β = 0.64, P < 0.001), left atrial area (β = 0.08, P = 0.002), pulmonary artery pressure (β = 0.08, P = 0.011) and E/Ea ratio (β = 0.04, P = 0.021).Conclusions:
Patients with sustained weight loss after bariatric surgery display less severe sleep apnea, reduced inflammatory activity, and enhanced cardiac function. Persisting sleep apnea appears to limit the beneficial effect of weight loss on inflammation and cardiac performance.17.
Astrid Müller Patrick Trotzke James E. Mitchell Martina de Zwaan Matthias Brand 《PloS one》2015,10(10)
The study was designed to develop a new screening instrument for pathological buying (PB), and to examine its psychometric properties in a large-scale sample. By using a facet theoretical approach and based on literature as well as on clinical experience, a 20-item Pathological Buying Screener (PBS) was developed and administered to a representative German sample (n = 2,539). Valid data were available from 2,403 participants who were subjects for three subsequent empirical studies. The first study explored the factor structure using exploratory factor analyses in a subsample of 498 participants. Based on factor loadings, a 13-item version with the two factors loss of control / consequences and excessive buying behavior was revealed. This two-factor model was confirmed in study 2 by confirmatory factor analysis performed on another subsample (n = 1,905). Study 3 investigated age and gender effects and convergent validity of the PBS using the Compulsive Buying Scale (CBS) in the full sample (N = 2,403). The total PBS score was adequately correlated with the CBS score. Hierarchical regression analyses with the CBS score as the dependent variable and the two PBS factors as the predictors indicated an own incremental validity of the two factors in participants ≤ 65 years. The reliability of the total score as well as of the two subscales was good to excellent. Overall, the PBS represents a useful measure for PB. Future studies are needed to replicate the two-factor structure in clinical samples and to define a valid cutoff for PB. 相似文献
18.
Christos Stritsis Bernd Steingrobe Norbert Claassen 《International journal of phytoremediation》2014,16(11):1104-1118
Maize, sunflower, flax, and spinach differed in the accumulation of Cd when grown on a Cd contaminated soil. This was mainly due to the different Cd net influx, In , that varied among species by a factor of up to 30. The objective of this study was to find possible reasons for the different Cd In by using a mechanistic model. After 14 days of Cd uptake the model calculated only a small Cd depletion at the root surface, e.g. from 0.22 μmol L?1down to 0.19 μmol L?1for maize and from 0.48 μmol L?1down to 0.35 μmol L?1for spinach. Even so the model always overestimated the Cd In , for spinach by a factor of 1.5 and for maize by a factor of 10. Only simulating a decrease of CLi or the root absorbing power, α, by 40% to 90% gave an agreement of calculated and measured In . This may be interpreted as that about 40% in the case of spinach and 90% in the case of maize of the Cd in soil solution were not accessible for plant uptake. The high sensitivity to α also shows that not the Cd transport to the root but α was limiting the step for Cd uptake. 相似文献
19.
《Chronobiology international》2013,30(2):239-252
Children who grow up in developing countries of the world must work to help financially support their families, and they must also attend school. We investigated the impact of work on the sleep of working vs. nonworking high school students. Twenty-seven São Paulo, Brazil, public high school students (eight male and eight female working students plus six nonworking female and five nonworking male students) 14–18 yrs of age who attended school Monday–Friday between 19:00 to 22:30 h participated. A comprehensive questionnaire about work and living conditions, health status, and diseases and their symptoms was also answered. The activity level and rest pattern (sleep at night and napping during the day) were continuously assessed by wrist actigraphy (Ambulatory Monitoring, USA). The main variables were analyzed by a two-factor ANOVA with application of the Tukey HSD test for multiple comparisons, and the length of sleep during weekdays vs. weekends was compared by Student t-test. Working students went to sleep earlier weekends [F(1,23) = 6.1; p = 0.02] and woke up earlier work days than nonworking students [F(1,23) = 17.3; p = 0.001]. The length of nighttime sleep during weekdays was shorter among all the working [F(1,23) = 16.7; p < 0.001] than all the nonworking students. The sleep duration of boys was shorter than of girls during weekends [F(1,23) = 10.8; p < 0.001]. During weekdays, the duration of napping by working and nonworking male students was shorter than nonworking female students. During weekdays, working girls took the shortest naps [F(1,23) = 5.6; p = 0.03]. The most commonly reported sleep complaint during weekdays was difficulty waking up in the morning [F(1,23) = 6.5; p = 0.02]. During weekdays, the self-perceived sleep quality of working students was worse than nonworking students [F(1,23) = 6.2; p = 0.02]. The findings of this study show that work has negative effects on the sleep of adolescents, with the possible build-up of a chronic sleep debt with potential consequent impact on quality of life and school learning. 相似文献
20.
This study examined the psychometric properties of the Connor-Davidson Resilience Scale (CD-RISC) with a Chinese military population with the aim of finding a suitable instrument to quantify resilience in Chinese military service members. The confirmatory factor analysis results did not support the factorial structure of the original or the Chinese community version of the CD-RISC, but the exploratory factor analysis results revealed a three-factor model (composed of Competency, Toughness, and Adaptability) that seemed to fit. Moreover, the repeat confirmatory factory analysis replicated the three-factor model. Additionally, the CD-RISC with a Chinese military sample exhibited appropriate psychometric properties, including internal consistency, test-retest reliability, and structural and concurrent validity. The revised CD-RISC with a Chinese military sample provides insight into the resilience measurement framework and could be a reliable and valid measurement for evaluating resilience in a Chinese military population. 相似文献