4C Model Research Articles

How body composition techniques measure up for reliability across the age-span

Reliability of body composition measurement techniques is essential to the accurate reporting of intervention outcomes. However, the between-day precision error of commonly used techniques, as well as the reference multi-compartment model, in a population-representative sample are currently unknown. To quantify technical and biological precision error of body composition techniques in comparison to the referent 4-compartment (4C) model. Men and women (1:1 ratio; 18-85 years old; n=90) completed 2 consecutive-day body composition testing sessions, including individual components of the referent 4C model. Testing was undertaken in accordance with best practice guidance for each technique, including standardized presentation and a consistent time of day. Repeat measurements were conducted on day 1 for technical precision, and between-day measurements were conducted for biological precision quantification. On average, all measurements met acceptable error limits and presented typically low technical and biological error [<2% fat-free mass (FFM) and<3% fat mass (FM) precision error]. For technical precision of FFM, all techniques met a priori cut points (80%; CV=0.45-0.81%). For FM, all techniques were equivalent to the best-rating method on average (CV=0.78-1.35%), except air displacement plethysmography (CV=2.13%). For biological precision, only 3-compartment (3C) and 4C equations sufficiently met the a priori determined cut point for estimates for FFM (CV=0.77-0.79%), and only DXA met the 80% cut point (CV=1.17%) for FM. The primary purpose of a study design is imperative when deciding on body composition assessment techniques used for longitudinal measurements. If reliable longitudinal assessments of FFM are central, a 3C or 4C model may be indicated. If FM is a primary outcome, DXA may be preferable. However, considering the low error rates presented within the current study across a broad age span of healthy adults with implementation of best-practice guidelines, any technique assessed here may be used, provided that strict protocols are adhered to.

IMPLEMENTASI PENDEKATAN SAINTIFIK DAN KECAKAPAN ABAD 21 DALAM RENCANA PELAKSANAAN PEMBELAJARAN

The pedagogical competence is the teacher's ability with regard to understanding of learners and the management of the debriefing from planning, executing to evaluating. This competence consists of the ability to develop a curriculum related to a capable subject. The problem identified is (1) a knowledge of the components in curriculum 2013's RPP; (2) the teacher's understanding of the saintifical approach and the scientific learning models; And (3) teachers' inadequate ability to create an RPP based curriculum 2013. The purpose of this PKM is increased development of RPP based on application of a saintifical approach based on curriculum 2013. The method in this PkM, first establishing the target area and applying the appropriate permits for carrying out the activity to authorized institutions. Second, coordinating with the head of SMP Binagreha Bogor and preparing training materials, the implementation of PPK, literacy, 4C, HOTS, scientific approaches, and scientific learning models. Third, training at SMP Binagreha Bogor. In the training, methods the team uses are methods of lectures, demonstrations, discussions, and tasks. The result of PkM in collaboration with SMP Binagreha Bogor in general is increased development of RPP based on application of a saintifical approach based on curriculum 2013. Specific targets that have been achieved in this activity is the increasing knowledge of PPK implementation, literacy, 4C, HOTS, scientific approaches, and scientific learning models in RPP

Combining Anthropometry and Bioelectrical Impedance Analysis to Predict Body Fat in Female Athletes.

Accurate methods for predicting the percentage of body fat (%Fat) in female athletes are needed for those who lose weight before competition. Methods mandated by sport governing bodies for minimal weight determination in such athletes lack validation. To (1) determine whether combining anthropometry using skinfold (SF) thicknesses and bioelectrical impedance analysis (BIA) in a 3-compartment (3C) model would improve the prediction of %Fat in female athletes and (2) evaluate the Slaughter SF equation. Cross-sectional study. Laboratory-based study during the preseason for collegiate sports. A total of 18 National Collegiate Athletic Association Division I female athletes were recruited from swim and gymnastics teams. We measured %Fat based on a 4-compartment (4C) criterion incorporating body density (air-displacement plethysmography), total body water (D2O dilution), and bone mineral mass (dual-energy x-ray absorptiometry) compared with predicted %Fat using SF alone (Slaughter equation), BIA (single frequency for total body water estimate), and combined SF and BIA (3C model). For the %Fat determined using the 4C criterion, the highest adjusted coefficient of determination and lowest prediction error (r2; ±standard error of estimate) were for the 3C model (r2 = 0.87; ±2.8%), followed by BIA (r2 = 0.80; ±3.5%) and SF (r2 = 0.76; ±3.8%; P values < .05 for all). Means differed for the %Fat determined using BIA (26.6% ± 7.5%) and the 3C (25.5% ± 7.2%) versus 4C model (23.5% ± 7.4%; analysis of variance and post hoc analyses: P values < .05). The SF estimate (24.0% ± 7.8%) did not differ from the 4C value. Combining SF and BIA might improve the prediction and lower the prediction error for determining the %Fat in female athletes compared with using SF or BIA separately. Regardless, the Slaughter equation for SF appeared to be accurate for determining the mean %Fat in these female athletes.

Changes in influenza vaccination coverage associated during the COVID-19 pandemic in Japan.

Changes in influenza vaccination coverage during the COVID-19 pandemic in Japan were limited. Not only changes in individual behavior and the threat of disease, but also vaccine dissemination policy based on system-based interventions, including behavioral economic approaches, is desirable.

Predicting Adaptations to Resistance Training Plus Overfeeding Using Bayesian Regression: A Preliminary Investigation.

Relatively few investigations have reported purposeful overfeeding in resistance-trained adults. This preliminary study examined potential predictors of resistance training (RT) adaptations during a period of purposeful overfeeding and RT. Resistance-trained males (n = 28; n = 21 completers) were assigned to 6 weeks of supervised RT and daily consumption of a high-calorie protein/carbohydrate supplement with a target body mass (BM) gain of ≥0.45 kg·wk−1. At baseline and post-intervention, body composition was evaluated via 4-component (4C) model and ultrasonography. Additional assessments of resting metabolism and muscular performance were performed. Accelerometry and automated dietary interviews estimated physical activity levels and nutrient intake before and during the intervention. Bayesian regression methods were employed to examine potential predictors of changes in body composition, muscular performance, and metabolism. A simplified regression model with only rate of BM gain as a predictor was also developed. Increases in 4C whole-body fat-free mass (FFM; (mean ± SD) 4.8 ± 2.6%), muscle thickness (4.5 ± 5.9% for elbow flexors; 7.4 ± 8.4% for knee extensors), and muscular performance were observed in nearly all individuals. However, changes in outcome variables could generally not be predicted with precision. Bayes R2 values for the models ranged from 0.18 to 0.40, and other metrics also indicated relatively poor predictive performance. On average, a BM gain of ~0.55%/week corresponded with a body composition score ((∆FFM/∆BM)*100) of 100, indicative of all BM gained as FFM. However, meaningful variability around this estimate was observed. This study offers insight regarding the complex interactions between the RT stimulus, overfeeding, and putative predictors of RT adaptations.

Validation of InBody 770 bioelectrical impedance analysis compared to a four-compartment model criterion in young adults.

Multi-frequency bioelectrical impedance analysis (MF-BIA) offers enhanced body composition outcomes in a time-efficient manner. The accuracy of stand-up MF-BIA compared against a four-compartment (4C) criterion lacks evidence. To validate a stand-up MF-BIA compared to a 4C criterion for fat mass (FM), fat-free mass (FFM) and body fat percentage (%fat). Eighty-two healthy (32% men) normal-weight (BMI: 18.5-24.9kg/m2 ) young adults were measured for body composition determined from a stand-up MF-BIA and 4C model. Validity statistics included total error (TE) and standard error of the estimate (SEE) to examine prediction error between methods. For the total sample, prediction error was the highest for %fat (TE=4.2%; SEE=3.9%) followed by FM (TE=2.4kg; SEE=2.2kg) and FFM (TE=2.4kg; SEE=2.2kg). In men, %fat (TE=2.5%; SEE=2.2%) and FM (TE=1.9kg; SEE=1.6kg) were ideal; FFM was similar to FM (TE=1.9kg; SEE=1.6kg). In women, %fat (TE=4.7%; SEE=4.4%) ranged from good to fairly good, and FM was very good to excellent (TE=2.6kg; SEE=2.4kg); FFM was similar to FM (TE=2.6kg; SEE=2.3kg). Stand-up MF-BIA may overestimate %fat and FM, and underestimate FFM compared to a 4C model. FM and FFM estimates from MF-BIA demonstrate good agreement to a 4C model and may be a practical measure of body composition in normal-weight adults. The highest error was seen in %fat for both sexes, with greater error in women.

Implementasi Pendekatan Saintifik dan Kecakapan Abad 21 dalam Rencana Pelaksanaan Pembelajaran

Pedagogy competence consists of the ability to develop a curriculum related to a capable subject. The problem identified is (1) a knowledge of the components in curriculum 2013's RPP; (2) the teacher's understanding of the saintifical approach and the scientific learning models; And (3) teachers' inadequate ability to create an RPP based curriculum 2013. The purpose of this PKM is increased development of RPP based on application of a saintifical approach based on curriculum 2013. The method in this PkM, first establishing the target area and applying the appropriate permits for carrying out the activity to authorized institutions. Second, coordinating with the head of SMP Binagreha Bogor and preparing training materials, the implementation of PPK, literacy, 4C, HOTS, scientific approaches, and scientific learning models. Third, training at SMP Binagreha Bogor. In the training, methods the team uses are methods of lectures, demonstrations, discussions, and tasks. The result of PkM in collaboration with SMP Binagreha Bogor in general is increased development of RPP based on application of a saintifical approach based on curriculum 2013. Specific targets that have been achieved in this activity is the increasing knowledge of PPK implementation, literacy, 4C, HOTS, scientific approaches, and scientific learning models in RPP.

The Design of a Gamified Responsible Use of Social Media

Social media is part of almost everyone's daily life. Its networking facilities redefines the way people connect and interact with each other. However, social media is reported being misused in different ways, especially the millennials. There is a need to elevate the teens' level of empowerment on the responsible use of social media. Other technological innovations like augmented reality (AR) and digital gamification provides pedagogical benefits. Digital gamification in the classroom is a teaching strategy that translates content and delivery into a game using digital technology. On the other hand, AR is an emerging technology to enlarge real-life situations in multimedia. Research shows both technologies increase interactivity well as attention span among the learners. Additionally, these technologies, including social media, are among the many useful tools in teaching twenty first century learners once correctly used. With this, a game-based mobile application was developed to advocate responsible use of social media among teens. The learning content was gamified in augmented reality to provide an innovative teaching and learning way at Silliman University. This paper describes the gamification design of the learning trail on the topic of responsible use of social media. Specifically, it presents the publishing process of the augmented reality mobile application about responsible use of social media. Kuhlmann's 3C Model (Challenge, Choices, Consequences) was utilized to formulate the learning content. It also demonstrates the design phases, game mechanics, and the general evaluation of the learning application. Four challenges were developed. These are (a) be familiar with security and privacy policies, (b) do not express concerns about others, even if you think you are anonymous, (c) respond to digital offenders, (d) do not tell the world about an upcoming vacation. These challenges were translated into graphics and animations. The animated material was compiled, programmed, and published to a server of the mobile application. The gamified learning trail on responsible use of social media is accessible through QR codes leading to the augmented reality interface. The design was validated and found to be relevant and engaging.

Validity of a 3-compartment body composition model using body volume derived from a novel 2-dimensional image analysis program.

The purpose of this study was: (1) to compare body volume (BV) estimated from a 2-dimensional (2D) image analysis program (BVIMAGE), and a dual-energy x-ray absorptiometry (DXA) equation (BVDXA-Smith-Ryan) to an underwater weighing (UWW) criterion (BVUWW); (2) to compare relative adiposity (%Fat) derived from a 3-compartment (3C) model using BVIMAGE (%Fat3C-IMAGE), and a 4-compartment (4C) model using BVDXA-Smith-Ryan (%Fat4C-DXA-Smith-Ryan) to a 4C criterion model using BVUWW (%Fat4C-UWW). Forty-eight participants were included (60% male, 22.9 ± 5.0 years, 24.2 ± 2.6 kg/m2). BVIMAGE was derived using a single digital image of each participant taken from the rear/posterior view. DXA-derived BV was calculated according to Smith-Ryan et al. Bioimpedance spectroscopy and DXA were used to measure total body water and bone mineral content, respectively, in the 3C and 4C models. A standardized mean effect size (ES) assessed the magnitude of differences between models with values of 0.2, 0.5, and 0.8 for small, moderate, and large differences, respectively. Data are presented as mean ± standard deviation. Near-perfect correlation (r = 0.998, p < 0.001) and no mean differences (p = 0.267) were observed between BVIMAGE (69.6 ± 11.5 L) and BVUWW (69.5 ± 11.4 L). No mean differences were observed between %Fat4C-DXA-Smith-Ryan and the %Fat4C-UWW criterion (p = 0.988). Small mean differences were observed between %Fat3C-IMAGE and %Fat4C-UWW (ES = 0.2, p < 0.001). %Fat3C-IMAGE exhibited smaller SEE and TE, and tighter limits of agreement than %Fat4C-DXA-Smith-Ryan. The 2D image analysis program provided an accurate and non-invasive estimate of BV, and subsequently %Fat within a 3C model in generally healthy, young adults.

A Scoping Review on Agency Collaboration in Emergency Management Based on the 3C Model

Most emergency responses involve collaborative efforts from teams operating in the field and in the backstage. Collaboration within and across agencies should therefore be regarded as an essential service in emergency management. We propose a conceptual lens to analyse the technological support to collaboration services in emergency management. The proposed lens is based on the 3C Model, which regards collaboration services as the articulation and composition of three other services: communication, coordination and cooperation. Using this lens, we conduct a scoping literature review of the emergency management domain. The review contributes to better understand the relationships between collaboration services and technology support in emergency management.

Agreement between laboratory methods and the 4-compartment model in assessing fat mass in obese older Hispanic-American adults

Densitometry (Siri's and Brožek's equations), hydrometry (by the deuterium dilution technique), and dual-energy X-ray absorptiometry (DXA) are three methods for estimating body composition. However, because they are all based on certain assumptions, they may not be applicable to aged and obese subjects due to changes in their body composition. Hence, the validity of these "laboratory methods" could be affected in obese older people. The main aim was to assess the agreement between densitometry, hydrometry, and DXA with the 4-compartment (4C) model to estimate fat mass (FM) in obese older Hispanic-American adults. As secondary goals, we explored whether the bias in densitometry and hydrometry results could be improved by modifying the assumptions regarding fat-free mass (FFM) density and hydration factor (HF) values, respectively. In the case of DXA, we explored the factors that contribute to bias. This is a cross-sectional study based on a sample of 171 obese subjects aged ≥60 years from 3 regions of northern Mexico. Body composition was assessed by the 4C model as the reference method and by all three laboratory methods. Agreement of the latter with the 4C model was probed by Bland and Altman analysis, a paired sample t-test, and simple linear regression analyses. In addition, the mean FFM density estimated in this sample, and HF values (published previously) of 0.737 and 0.753 for obese older Hispanic-American men and women, respectively, were considered as ethnic- and gender-specific values. These values were used to modify the densitometric and hydrometric equations in order to improve their bias. Finally, we tested whether the hydration status and indirect markers of adiposity are contributing factors to the bias of DXA using multiple linear regression analysis. Siri's equation overestimated FM by 0.57kg (p<0.01), while Brožek's equation, hydrometry, and DXA underestimated it by 1.24kg, 0.89kg, and 0.79kg (p<0.01), respectively, compared to the 4C model. The bias in the densitometry and hydrometry results was eliminated by substituting the ethnic- and gender-specific values into the equations. Finally, we found that hip circumference contributes to the bias in DXA. The densitometry, hydrometry, and DXA methods are not interchangeable with the 4C model for assessing fat mass in obese, older Hispanic-American adults. The lack of agreement could indicate that the assumptions of each method do not apply to this population.

Evaluation of Obesity Cutoff Values in Hispanic Adults: Derivation of New Standards

The diagnostic accuracy of clinical-based body composition methods such as body mass index (BMI), waist circumference (WC), bioimpedance analysis (BIA), and dual energy X-ray absorptiometry (DXA) has yet to be evaluated in Hispanic adults. Moreover, it has also been suggested that previously established obesity cutoff values may need adjusting. Purpose: The primary aim of this study was to investigate the diagnostic accuracy of BMI, WC, BIA, and DXA for obesity classification in Hispanic adults. The secondary aim was to internally derive obesity cutoff values producing equal sensitivity and specificity for the respective tests. Methods: Hispanic females (n = 101) and males (n = 90) volunteered to participate in this study (18–45 years). Body fat percentage was estimated with BIA, DXA, and a 4-compartment (4C) model. Obesity-defined criteria was employed as follows: (Body fat percentage ≥ 25% and 35% and WC ≥ 102cm and 88cm for males and females, respectively; BMI ≥ 30 kg/m2). A 4C model was used as a criterion to evaluate BMI, WC, DXA, and BIA. Results: Sensitivity of DXA and BIA (74.1%–96.9%) was greater than BMI and WC (25.8%–51.9%) when using previously established standards. However, specificity was poor for DXA (<70%), but considered good to excellent for BMI, WC, and BIA (83.1%–96.6%) when using previously established standards. Internally derived cutoff values improved sensitivity for BMI and WC (74.2%–81.5%) and improved specificity for DXA (>80.0%). Conclusion: The internally derived cutoff values, producing identical sensitivity, and specificity, were developed and shown to improve the diagnostic performance of the body composition methods compared to previously established obesity cutoff standards. Consequently, the internally derived obesity cutoff values are recommended for use by allied health professionals in clinical practice when equal sensitivity and specificity is desired.

Anthropometric and bioimpedance equations for fat and fat-free mass in Chilean children 7-9 years of age.

Assessing children's growth adequately is important due to the necessary prevention of adequate body composition, especially at pre-pubertal age. Simpler measurements such as anthropometry or bioimpedance, using equations validated in Caucasian children, have been demonstrated to overestimate or underestimate fat mass percentage (FM%) or fat-free mass (FFM) in Chilean children. In a sample of 424 children (198 boys and 226 girls) of 7-9 years old, the three component (3C) model was assessed, where total body water was determined by 2H dilution and body volume by air displacement plethysmography, in order to design and validate anthropometry and bioimpedance equations. The FM (%) equation specific for Chilean children was validated as (1·743 × BMI z-score) + (0·727 × triceps skinfold) + (0·385 × biceps skinfold) + 15·985, against the 3C model (R2 0·79). The new FFM equation (kg) generated was (log FFM = (0·018 × age) + (0·047 × sex) + (0·006 × weight) + (0·027 × resistance) + 2·071), with an R2 0·93 (female = 1 and male = 2). The Bland-Altman analysis shows a mean difference of 0·27 (sd 3·5) for the FM% in the whole group as well as 0·004 (sd 0·9) kg is the mean difference for the bioelectrical impedance analysis (BIA) FFM (kg) equation. The new equations for FM (%) and FFM (kg) in Chilean children will provide a simple and valid tool for the assessment of body composition in cohort studies or to assess the impact of nutritional programmes or public policies.

Next generation sequencing applied to food safety. A new professional profile

Abstract The advent of “omics” is transforming Biological Sciences. Next Generation Sequencing (NGS) in Food Safety represents a challenge for Clinical Microbiology and Public Health. A new professional profile which combines different domains represents a strategic lever to increase competitiveness in this field. The Erasmus+ project Learning Genomics for Food Safety(LEGO) is aimed at defining an innovative profile, the Food Microbial Bioinformatician (FMB), a professional able to use NGS technologies applied to the analysis of food-borne pathogens. FMB bridges diverse professional areas within processes integrating Genomics, Computer Science, Statistics and Microbiology. It mixes hard/technical and soft skills and competencies to be applied in different sectors. LEGO is carried out by a European consortium (UH, UTP,UNIVAQ, AINIA, UdAnet), led by IZSAM.Desk and in-field research activities have been conducted at European level to define the FMB profile, leveraging on: national/international professional classification; the 4C model, clustering the profile in 4 areas of hard and soft skills(primary - cognitive, individual, social; organisational interpersonal behaviours). The new profile development process is made of three key phaces. First of all, a questionnaire has been delivered to almost 50 experts within the Consortium to set the draft scheme concerning FMB roles, activities and competences. Secondly, a broad range of relevant stakeholders have beeninvolved for deepening relevance, frequency and complexity of each professional dimension. Finally, the collected information guided the Consortium through the validation of the new profile at the European level. The definition of a comprehensive, standard FMB profileallows to: analyse existing curricula and training gaps; ground customised modular training programmes to fill in the gaps; increase Food Safety, promoting continuous training in a sector strongly influenced by the evolution of technology. Key messages Professional excellence bridging different areas (both scientific and technical).Health System innovation for wellbeing and professional development of carrier pathways and mobility.

Emerging cross-disciplinary profiles: The Geomatic Epidemiologist

Abstract Issue Geographic information systems (GIS) and remote sensing technologies are increasingly used in Public Health epidemiology, showing a great potential in anticipating and responding to actual and future challenges for the public health system and in improving health services' excellence. According to the evidences collected within a wide meta-research carried on of relevant literature (”GIS geographic information system” and “GIS geographic information system and training” on Pubmed; “epidemiologist use of GIS and training” and “epidemiologist use of gis” on Google Scholar),GIS and new sensing technologies are mostly used to: map air and water pollution, map diseases prevalence, predict infection diseases and vector-spread diseases in big areas, study health service coverage and preparedness in emergencies, map cities and study urban health, study climate changes for decision making. Description of the Problem Specific skills and training are required to address the use of GIS and new sensing technologies.The specific aim of our study is to identify the professional profile of a new figure, called 'Geomatic Epidemiologist' and to define its professional and educational standards, as well as the relevant training programs. Results Data collection and analysis of INAPP and ESCO databases about existing professional profiles (starting from 2016) has allowed drafting a first qualification schema and profile. The profile has been defined according to the 4C model (elaborated by Univaq) distinguishing between Hard Skills (technical knowledge and skills),Soft Skills (cognitive, individual and social) and interpersonal behaviors. Conclusions Profile will be validated with relevant stakeholders and Public Health professionals in order to deepen the understanding of the main competences required to study health issues with GIS and related technologies; to this extent, a questionnaire has been elaborated to evaluate relevance, frequency and complexity of each component of the profile Key messages Developing cross-disciplinary profiles, (i.e. the Geomatic Epidemiologist) integrating clusters of competences (holistic approach). Public health research challenges and excellence.

Institutional Voids and Social Entrepreneurship: How are Social Entrepreneurs Developing Unique Strategies to Cope with Institutional Voids?

A firm’s performance is shaped by its ability to effectively manage the institutional context of its operations. With the institutional settings of developing countries varying greatly from those of developed countries, institutional voids are expected to impact social enterprises (SEs) differently due to their hybridity, in comparison to their western counterparts as well as their local counterparts (traditional for-profit businesses). Thus, whilst developing strategies to cope with institutional arrangements is important everywhere, it is more critical for SEs in particular, and entrepreneurs in general, operating in developing countries due to the underdeveloped institutional regimes that those entrepreneurs face. Yet theories and findings have been dominated by observations of, and insights derived from, developed market contexts with the few conducted in developing countries focusing largely on MNEs. Relying on an exploratory multiple-case study approach, this study seeks to strengthen and deepen our understanding of “social entrepreneurship” in and around institutional voids such as those found in developing countries. Specifically, the study explores how social entrepreneurs are developing unique strategies to cope with formal market institutional voids. Through a multiple case study of nine social enterprises, this paper theorizes a model, herein referred to as the Creative action-Connection-Capability-building and education model (3C model) that depicts the three key strategies that social entrepreneurs rely on in order to achieve their aims while overcoming institutional voids. The study contributes to the literature on institutional strategizing by illustrating how micro and small firms respond to formal market voids.

A mathematical model of dynamics of cell populations in squamous epithelium after irradiation

Purpose To develop multi-compartment mechanistic models of dynamics of stem and functional cell populations in epithelium after irradiation. Methods and materials: We present two models, with three (3C) and four (4C) compartments respectively. We use delay differential equations, and include accelerated proliferation, loss of division asymmetry, progressive death of abortive stem cells, and turnover of functional cells. The models are used to fit experimental data on the variations of the number of cells in mice mucosa after irradiation with 13 Gy and 20 Gy. Akaike information criteria (AIC) was used to evaluate the performance of each model. Results Both 3C and 4C models provide good fits to experimental data for 13 Gy. Fits for 20 Gy are slightly poorer and may be affected by larger uncertainties and fluctuations of experimental data. Best fits are obtained by imposing constraints on the fitting parameters, so to have values that are within experimental ranges. There is some degeneration in the fits, as different sets of parameters provide similarly good fits. Conclusions The models provide good fits to experimental data. Mechanistic approaches like this can facilitate the development of mucositis response models to nonstandard schedules/treatment combinations not covered by datasets to which phenomenological models have been fitted. Studying the dynamics of cell populations in multifraction treatments, and finding links with induced toxicity, is the next step of this work.

Estimating resting energy expenditure from dual-energy X-ray absorptiometry: A cross-sectional study in healthy young adults.

To qualify a 3C approach model of dual-energy X-ray absorptiometry (DXA) to estimate multicomponent resting energy expenditure (REE) referenced by indirect calorimetry (IC). A sample of 155 college students, of both sexes (18-30 years old) was evaluated. Anthropometric measures, REE by IC, and whole-body DXA-scans were performed. The REE for each body component was determined after transforming the components from the molecular (DXA) to the organ tissue level. Bland-Altman and proportional bias analyses were used to verify agreement between REE measured (REEIC ) and estimated (REEDXA ). Statistically significant differences were found for all sex comparisons (P < .001), except for age (P = .950). Differences from the final sex-specific models' were not found between REEIC and REEDXA (P > .05). Men also presented greater expenditure (P < .001) in each component, except for adipose tissue. The plots confirmed the validity of the model for both sexes, with low difference values between the measured and estimated REE. The mean of the differences of REEIC and REEDXA showed heteroscedasticity of the data for men (P = .004). The same error tendency was not evident for women (P = .333). This 3C model, estimating REE from a multicomponent approach, allows a new application of DXA as tool for understanding intraindividual differences in terms of the mass of metabolically active tissue. Sex and populational differences should be taken in account. Consequently, we present qualified sex-specific DXA models that can be applied in different contexts such as health and sports, besides considering interpersonal differences in terms of energy expenditure.

Development Of A Dxa-derived Body Volume Equation In Hispanic Adults For Administering In 4-compartment Models

PURPOSE: The purpose of the current study was two-fold: 1) to develop a new dual energy X-ray absorptiometry (DXA)-derived body volume (BV) equation with the GE-Lunar Prodigy while utilizing underwater weighing (UWW) as a criterion and 2) cross-validate 4-compartment(4C) models when utilizing the new DXA-derived BV equation (4C-DXANICKERSON), Wilson DXA-derived BV equation (4C-DXAWILSON), and air displacement plethysmography (ADP)-derived BV (4C-ADP) in Hispanic adults. METHODS: 191 Hispanic adults (18-45yrs) participated in the current study. The development sample consisted of 60 females and 60 males whereas the cross-validation sample comprised of 41 females and 30 males. Criterion body fat percentage (BF%) and fat-free mass (FFM) were determined using a 4C model with UWW as a criterion for BV (4C-UWW). The new DXA-derived BV equation (Nickerson) was developed by linearly regressing UWW-derived BV with DXA fat mass (FM), lean mass (LM), and bone mineral content (BMC). 4C-DXANICKERSON, 4C-DXAWILSON, and 4C-ADP were compared against 4C-UWW in the cross-validation sample. RESULTS: The new DXA-derived BV equation (L) was generated in the development sample as follows: (FM/0.91) + (LM/1.06) + (BMC/16.95) + 0.268. 4C-DXANICKERSON, 4C-DXAWILSON, and 4C-ADP all produced similar mean values (BF%=21.04±5.99, 22.23±6.93, and 20.62±6.26%, respectively) when compared to 4C-UWW (21.29±6.14%) in Hispanic males (all p>0.05). 4C-DXANICKERSON also yielded similar BF% and FFM values as 4C-UWW when evaluating the constant error (CE) in Hispanic females (CE=-0.79% and 0.38kg; p=0.060 and 0.174, respectively). However, 4C-DXAWILSON produced significantly different BF% and FFM values (CE=3.22% and -2.20kg, respectively; both p<0.001). Additionally, 4C-DXAWILSON yielded significant proportional bias when estimating BF% (coefficient=0.226; p<0.001) whereas 4C-ADP produced significant proportional bias for BF% and FFM (coefficient=0.188 and -0.084; both p<0.05) when evaluated in Hispanic females. CONCLUSIONS: Current study findings demonstrate that 4C-DXANICKERSON is a valid measure of BV in Hispanics and is recommended for use in clinics where DXA is the main body composition assessment technique.

Beyond agency and stewardship theory: shareholder–manager relationships and governance structures in family firms

PurposeChallenging the static view of family business governance, we propose a model of owner–manager relationships derived from the configurational analysis of managerial behavior and change in governance structure.Design/methodology/approachStemming from social exchange theory and building on the 4C model proposed by Miller and Le Breton-Miller (2005), we consider the evolving owner–manager relationship in four main configurations. On the one hand, we account for family businesses shifting from a generalized to a restricted exchange system, and vice versa, according to whether a family manager misbehaves in a stewardship-oriented governance structure or a nonfamily manager succeeds in building a trusting relationship in an agency-oriented governance structure. On the other hand, we consider that family firms will strengthen a generalized exchange system, rather than a restricted one, according to whether a family manager contributes to the stewardship-oriented culture in the business or a nonfamily manager proves to be driven by extrinsic rewards. Four scenarios are analyzed in terms of the managerial behavior and governance structure that characterize the phases of the relationship between owners and managers.FindingsVarious factors trigger managerial behavior, making the firm deviate from or further build on what is assumed by stewardship and agency theories (i.e. proorganizational versus opportunistic behavior, respectively), which determine the governance structure over time. Workplace deviance, asymmetric altruism and patriarchy on the one hand, and proorganizational behavior, relationship building and long-term commitment on the other, are found to determine how the manager behaves and thus characterize the owner's reactions in terms of governance mechanisms. This enables us to present a dynamic view of governance structures, which adapt to the actual attitudes and behaviors of employed managers.Research limitations/implicationsAs time is a relevant dimension affecting individual behavior and triggering change in an organization, one must consider family business governance as being dynamic in nature. Moreover, it is not family membership that determines the most appropriate governance structure but the owner–manager relationship that evolves over time, thus contributing to the 4C model.Originality/valueThe proposed model integrates social exchange theory and the 4C model to predict changes in governance structure, as summarized in the final framework we propose.