Correction to: Application of a multiphase microreactor chemostat for the determination of reaction kinetics of Staphylococcus carnosus.

Unfortunately, in the "How to Cite as" section, the given and the family name of the author was incorrectly published, the correct name is Lladó Maldonado. S.

Application of a multiphase microreactor chemostat for the determination of reaction kinetics of Staphylococcus carnosus.

Bioreactors at the microliter scale offer a promising approach to accelerate bioprocess development. Advantages of such microbioreactors include a reduction in the use of expensive reagents. In this study, a chemostat operation mode of a cuvette-based microbubble column bioreactor made of polystyrene (working volume of 550 µL) was demonstrated. Aeration occurs through a nozzle (Ø ≤ 100 µm) and supports submerged whole-cell cultivation of Staphylococcus carnosus. Stationary concentrations of biomass and glucose were determined in the dilution rate regime ranging from 0.12 to 0.80 1/h with a glucose feed concentration of 1 g/L. For the first time, reaction kinetics of S. carnosus were estimated from data obtained from continuous cultivation. The maximal specific growth rate (µmax = 0.824 1/h), Monod constant (KS = 34 × 10- 3gS/L), substrate-related biomass yield coefficient (YX/S = 0.315 gCDW/gS), and maintenance coefficient (mS = 0.0035 gS/(gCDW·h)) were determined. These parameters are now available for further studies in the field of synthetic biology.

A compact design for velocity-map imaging of energetic electrons and ions.

We present a compact design for a velocity-map imaging spectrometer for energetic electrons and ions. The standard geometry by Eppink and Parker [Rev. Sci. Instrum. 68, 3477 (1997)] is augmented by just two extended electrodes so as to realize an additional einzel lens. In this way, for a maximum electrode voltage of 7 kV, we experimentally demonstrate imaging of electrons with energies up to 65 eV. Simulations show that energy acceptances ≲270 and ≲1200 eV with an energy resolution ΔE∕E≲5% are achievable for electrode voltages ≤20 kV when using diameters of the position-sensitive detector of 42 and 78 mm, respectively.

An examination of the bidirectional relationship between functioning and symptom levels in patients with anxiety disorders in the CALM study.

BACKGROUND: Patients with anxiety disorders suffer marked functional impairment in their activities of daily living. Many studies have documented that improvements in anxiety symptom severity predict functioning improvements. However, no studies have investigated how improvements in functioning simultaneously predict symptom reduction. We hypothesized that symptom levels at a given time point will predict functioning at the subsequent time point, and simultaneously that functioning at a given time point will predict symptom levels at a subsequent time point. METHOD: Patients were recruited from primary-care centers for the Coordinated Anxiety Learning and Management (CALM) study and were randomized to receive either computer-assisted cognitive-behavioral therapy and/or medication management (ITV) or usual care (UC). A cross-lagged panel design examined the relationship between functional impairment and anxiety and depression symptom severity at baseline, 6-, 12-, and 18-month follow-up assessments. RESULTS: Prospective prediction of functioning from symptoms and symptoms from functioning were both important in modeling these associations. Anxiety and depression predicted functioning as strongly as functioning predicted anxiety and depression. There were some differences in these associations between UC and ITV. Where differences emerged, the UC group was best modeled with prospective paths predicting functioning from symptoms, whereas symptoms and functioning were both important predictors in the ITV group. CONCLUSIONS: Treatment outcome is best captured by measures of functional impairment as well as symptom severity. Implications for treatment are discussed, as well as future directions of research.

Mediating mechanisms in a program to reduce intentions to use anabolic steroids and improve exercise self-efficacy and dietary behavior.

This study investigated the mediating mechanisms responsible for the effects of a program designed to reduce intentions to use anabolic steroids, improve nutrition, and increase strength training self-efficacy. Fifteen of 31 high school football teams (N = 1,506 players at baseline) in Oregon and Washington were assigned to receive the intervention. The multicomponent program addressed the social influences promoting ergogenic drug use and engaging students in healthy nutrition and strength training alternative behaviors. Although the results differed across the three dependent variables, the program appeared to work by changing team norms. Unlike prevention of other drugs, changes in knowledge and perceived severity were mediators of program effects in this study.

Multilevel Modeling of Individual and Group Level Mediated Effects.

This article combines procedures for single-level mediational analysis with multilevel modeling techniques in order to appropriately test mediational effects in clustered data. A simulation study compared the performance of these multilevel mediational models with that of single-level mediational models in clustered data with individual- or group-level initial independent variables, individual- or group-level mediators, and individual level outcomes. The standard errors of mediated effects from the multilevel solution were generally accurate, while those from the single-level procedure were downwardly biased, often by 20% or more. The multilevel advantage was greatest in those situations involving group-level variables, larger group sizes, and higher intraclass correlations in mediator and outcome variables. Multilevel mediational modeling methods were also applied to data from a preventive intervention designed to reduce intentions to use steroids among players on high school football teams. This example illustrates differences between single-level and multilevel mediational modeling in real-world clustered data and shows how the multilevel technique may lead to more accurate results.

Acculturation and family functioning are related to health risks among pregnant Mexican American women.

The authors examined the independent and interactive effects of acculturation status and family cohesiveness on a series of psychosocial and medical risk factors of pregnancy among 500 women of Mexican origin. In general, both higher and lower levels of acculturation produced positive or negative psychosocial and healthcare consequences, and the operative relationships depended heavily on the particular outcome chosen. Higher levels of family cohesiveness tended to foster the most constructive health and psychosocial outcomes. However, in some circumstances higher levels of family cohesiveness resulted in less coping and a lower quality of prenatal care for less acculturated women. An important implication of this study is that psychosocial and health information can be obtained through assessments that identify different subgroups of Mexican American women and depend on women's level of acculturation and family cohesiveness. Culturally competent health practitioners or clinicians can conduct these assessments in a prenatal healthcare setting.

The relation of personality to alcohol abuse/dependence in a high-risk sample.

The current study had two goals. The first goal was to test the mediational role of young adult personality in the relation between parental alcoholism and young adult alcoholism. The second was to examine the associations between personality and alcohol use motives and reasons to limit drinking in order to explore possible mechanisms by which personality may influence alcohol abuse/dependence. Multilevel modeling techniques were used to analyze data obtained from a community sample of young adult children of alcoholics and demographically matched controls. Results revealed that young adult neuroticism and agreeableness each, in part, mediated the effect of parental alcoholism on young adult alcoholism. Moreover, individuals high in neuloticism reported stronger coping motives to use alcohol, individuals low in agreeableness reported stronger coping motives and weaker upbringing reasons to limit drinking, and individuals low in conscientiousness reported stronger coping and enhancement motives to use alcohol, and weaker performance reasons to limit drinking.

Equivalence of the mediation, confounding and suppression effect.

This paper describes the statistical similarities among mediation, confounding, and suppression. Each is quantified by measuring the change in the relationship between an independent and a dependent variable after adding a third variable to the analysis. Mediation and confounding are identical statistically and can be distinguished only on conceptual grounds. Methods to determine the confidence intervals for confounding and suppression effects are proposed based on methods developed for mediated effects. Although the statistical estimation of effects and standard errors is the same, there are important conceptual differences among the three types of effects.

Determinants of birth-weight outcomes among Mexican-American women: examining conflicting results about acculturation.

In this article, we describe a comprehensive model for exploring the determinants of birth-weight outcomes among Mexican-American women from the Arizona Perinatal Acculturation Project. Data for this article came from a longitudinal study consisting of two phases. In phase one, a detailed prenatal survey was administered to 500 pregnant women. Phase two consisted of a postnatal survey administered to the women at least three months after they delivered (N = 269). Subjects who provided data were recruited from two health care agencies. Separate model building processes were conducted for a continuous measure of birth weight, and a dichotomous indicator of low-moderate birth weight (<2900 grams) using multiple linear and logistic regression analyses, respectively. The potential predictor variables for the models were divided into twelve predictor sets. The results showed that both final models included a combination of biological/behavioral factors, as well as protective sociocultural factor indicators. Acculturation status, one of the primary variables of interest in the study was found to be important for predicting birth weight and low-moderate birth weight. This result did not change when low birth weight (<2500 grams) infants were removed from the analyses. Low acculturation status was found to be associated with better birth-weight outcomes than high acculturation status. Surprisingly, length of US residence had an opposite effect in predicting both birth-weight indicators when compared to acculturation status. These results suggest that the relationships between acculturation and birth outcomes should be redefined to take into account the complexity of the phenomenon of acculturation in addition to the measurement of an array of family and sociocultural factors.

Multilevel mediation modeling in group-based intervention studies.

This article proposes and evaluates a method to test for mediation in multilevel data sets formed when an intervention administered to intact groups is designed to produce change in individual mediator and outcome variables. Simulated data of this form were used to compare ordinary least squares (OLS) and two multilevel estimators of the mediated effect. OLS and multilevel standard error approximations were also evaluated and recommendations given for optimal estimator choice. These methods were applied to data from an existing substance use intervention to show the impact multilevel mediation modeling can have on the conclusions drawn from real-world evaluation studies.

Experimental personality designs: analyzing categorical by continuous variable interactions.

Theories hypothesizing interactions between a categorical and one or more continuous variables are common in personality research. Traditionally, such hypotheses have been tested using nonoptimal adaptations of analysis of variance (ANOVA). This article describes an alternative multiple regression-based approach that has greater power and protects against spurious conclusions concerning the impact of individual predictors on the outcome in the presence of interactions. We discuss the structuring of the regression equation, the selection of a coding system for the categorical variable, and the importance of centering the continuous variable. We present in detail the interpretation of the effects of both individual predictors and their interactions as a function of the coding system selected for the categorical variable. We illustrate two- and three-dimensional graphical displays of the results and present methods for conducting post hoc tests following a significant interaction. The application of multiple regression techniques is illustrated through the analysis of two data sets. We show how multiple regression can produce all of the information provided by traditional but less optimal ANOVA procedures.

Cancer risk reduction in Mexican American women: the role of acculturation, education, and health risk factors.

This article describes a two-factor schema for the development of culturally appropriate cancer risk reduction interventions for Mexican American women. Regarding this approach, risk factors for two major cancer areas are reviewed: cigarette smoking and obesity/diet. We first describe a schema that facilitates the planning of strategies associated with preferred health interventions and preventive approaches for cancer risk reduction with Mexican American and other Latino/Hispanic persons. This schema examines Acculturation and Education as key factors that should be considered in developing health education messages and interventions that are culturally and educationally appropriate to the identified subpopulations of Hispanics in terms of language and informational content of the message and in terms of psychological factors related to health behavior change. Empirical data from a community sample is presented for the purpose of illustrating the validity of this schema. Then we review studies that examine the effect of acculturation on the distribution of the risk factors, based on studies in the current literature. Here we note the target group of women with the highest risk, based on the available information on Acculturation and other sociodemographic factors. Additionally, an illustration is presented where information and the concepts offered by the two-factor schema facilitate the analysis of (a) health education message needs and (b) needed behavior change, thus pointing to (c) more appropriate health promotion strategies for targeted Hispanic/Latino individuals or groups. The information described in this article aims to help program planners, researchers, and health educators in the design of more effective programs of health intervention for Mexican American and other Hispanic/Latino women.

Application of long synthetic oligonucleotides for gene analysis: effect of probe length and stringency conditions on hybridization specificity.

Two different lengths of long unique synthetic oligonucleotide probes (37- and 48-mers) specific for human major histocompatibility complex (MHC) class II beta genes were synthesized. These oligonucleotides were utilized to examine factors influencing hybridization specificity. Both probe length and stringency of washing conditions were found to be crucial factors for sequence-specific hybridization.

Pharmacokinetics and pharmacodynamics of atenolol in children.

The pharmacokinetics and pharmacodynamics of intravenous atenolol were studied in 10 children during cardiac electrophysiologic studies. The intravenous pharmacokinetic data were best described by a two-compartment model and revealed the following (mean +/- SD): total body clearance, 0.15 +/- 0.06 L/hr/kg; volume of the central compartment 0.33 +/- 0.06 L/kg; volume of distribution at steady state, 0.83 +/- 0.15 L/kg; distributive elimination half-life, 0.29 +/- 0.08 hour; and terminal elimination half-life, 4.56 +/- 1.05 hours. The data suggest that children have a slightly shorter terminal elimination half-life than that of adults. Pharmacodynamic data showed a significantly (p less than 0.01) increased sinus cycle length and an increase in His to ventricle conduction time (p less than 0.05). Further studies are necessary to determine the optimal oral dose and dosing frequency of atenolol and to access the response of children to long-term treatment.

Application of synthetic oligonucleotides to detect DQ beta genes transmission within insulin-dependent diabetes families.

Class II antigen genes encoded by the major histocompatibility complex region (HLA-D region) in man play an important role in susceptibility to insulin dependent diabetes mellitus (IDDM). Evidence suggests that the DQ subregion within the HLA-D region is more directly responsible for susceptibility to IDDM. Therefore, we designed a synthetic oligonucleotide specific for the DQ beta gene to further the understanding of the disease association with HLA-D region genes at the molecular level. Restriction fragment length polymorphism (RFLP) analysis was carried out using DNA isolated from nine families, each including at least two affected siblings (a total of 37 siblings). The segregation pattern of hybridizing fragments showed that: (1) for each of the DR2, DR3, and DR4 specificities, two different alleles can be identified by the DQ beta probe; (2) a 1.9 kb-Taq 1 fragment with the DR4 specificity and a 6.0 kb-Taq-1 fragment within the DR2 specificity tend to cosegregate with IDDM; (3) there was no preferential segregation of the two alleles detected within the DR3 specificity (one allele identified by a 4.7 kb-Taq 1 fragment is quite common among individuals with the DR3 specificity). The results from this study add to the evidence that certain DQ alleles appear to be more directly associated with the diabetogenic gene (or genes) in certain DR specificities.

Effect of the counterforce armband on wrist extension and grip strength and pain in subjects with tennis elbow.

This study investigated the effect of the lateral counterforce armband on wrist extension and grip strength, and pain of 14 subjects with tennis elbow. Dynametric strength tests and pain analogue scale assessments were obtained on the affected and unaffected arms of subjects, while wearing the armband and without wearing the armband. Use of the armband produced parallel effects in both the affected and unaffected arms, i.e., increases in wrist extension and grip strength. The greatest effects were seen in the affected arm. There was a statistically significant increase in wrist extension strength with the armband on relative to without the armband. The increase in wrist extension strength approximately doubled the increase in grip strength for both arms, indicating the armband's greater influence on wrist extension. Although there was a low negative correlation between changes in pain and strength, it was not statistically significant. J Orthop Sports Phys Ther 1989;11(5):192-197.