Social Cognitive Theory Variables as Correlates of Physical Activity Behavior Among Hispanics With Multiple Sclerosis.

OBJECTIVE: To examine the association between social cognitive theory (SCT) variables and physical activity (PA) behavior in Hispanic adults with multiple sclerosis (MS). DESIGN: Observational, survey study. SETTING: General community. PARTICIPANTS: Inclusion criteria: (a) age 18 years or older, (b) self-identify as Hispanic or Latino, (c) diagnosis of MS, and (d) English or Spanish as primary language. Two hundred forty-three individuals opened the survey, 24 individuals did not meet inclusion criteria, and 66 individuals were excluded due to not completing any of the SCT variable measures (N=153). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): PA was measured using the Godin Leisure Time Exercise Questionnaire (GLTEQ) total and Health Contribution Scores (HCS). SCT variables included standard measures of exercise self-efficacy, planning, goal setting, outcome expectations, social support, and functional impairment. RESULTS: The final sample included 153 participants with a mean (SD) age of 43 (11) years, 78% identified as women, 57% were employed, and 63% had a college degree or higher. The mean (SD) MS disease duration was 11 (9) years, 74% of participants reported relapsing remitting MS, and median (interquartile range) Patient Determined Disease Steps (PDDS) score was 3.0 (3.0). Significant correlations were observed between all SCT variables and both GLTEQ total and GLTEQ HCS scores (P<.001). Forward stepwise regression with Akaike's Information Criterion (AICC) identified PDDS, age, exercise planning, exercise self-efficacy, and exercise goal setting as the most appropriate covariates and SCT variables to include in a multivariable model examining independent contributions on GLTEQ HCS scores. The multivariable, linear regression analysis indicated that PDDS (Standardized B=-.280, P<.001), exercise planning (Standardized B=.214, P<.05), and exercise self-efficacy (Standardized B=.183, P<.05) explained 42.4% of variance in GLTEQ HCS scores. CONCLUSIONS: This study provides a contribution to the literature by identifying SCT variables that correlate with PA behavior among Hispanics with MS that may guide the creation of culturally appropriate PA programs.

Correlates of missed or late versus timely diagnosis of dementia in healthcare settings.

INTRODUCTION: There is limited evidence about factors related to the timeliness of dementia diagnosis in healthcare settings. METHODS: In five prospective cohorts at Rush Alzheimer's Disease Center, we identified participants with incident dementia based on annual assessments and examined the timing of healthcare diagnoses in Medicare claims. We assessed sociodemographic, health, and psychosocial correlates of timely diagnosis. RESULTS: Of 710 participants, 385 (or 54%) received a timely claims diagnosis within 3 years prior to or 1 year following dementia onset. In logistic regressions accounting for demographics, we found Black participants (odds ratio [OR] = 2.15, 95% confidence interval [CI]: 1.21 to 3.82) and those with better cognition at dementia onset (OR = 1.48, 95% CI: 1.10 to 1.98) were at higher odds of experiencing a diagnostic delay, whereas participants with higher income (OR = 0.89, 95% CI: 0.81 to 0.97) and more comorbidities (OR = 0.94, 95% CI: 0.89 to 0.98) had lower odds. DISCUSSION: We identified characteristics of individuals who may miss the optimal window for dementia treatment and support. HIGHLIGHTS: We compared the timing of healthcare diagnosis relative to the timing of incident dementia based on rigorous annual evaluation. Older Black adults with lower income, higher cognitive function, and fewer comorbidities were less likely to be diagnosed in a timely manner by the healthcare system.

Latin Dance Effects on Cardiorespiratory Fitness and Physical Function in Middle-Aged and Older Latino Adults.

We tested if a dance trial yielded improvements in physical function and cardiorespiratory fitness (CRF) in middle-aged/older Latino adults. Physical activity was assessed using the Community Healthy Activities Model Program for Seniors, physical function with the Short Physical Performance Battery (SPPB) protocol, and estimated CRF with the Jurca nonexercise test model. Multivariate analysis of covariance models found significant change in SPPB protocol total scores, F(1, 329) = 4.23, p = .041, and CRF, F(1, 329) = 5.16, p = .024, between the two study arms in favor of the dance group. Mediation models found moderate- to vigorous-intensity physical activity to mediate to mediate between group and SPPB scores (ß = 0.054, 95% confidence interval [0.0142, 0.1247]). Moderate- to vigorous-intensity physical activity and total physical activity were found to partially mediate between group and CRF (ß = 0.02, 95% confidence interval [-0.0261, 0.0751]), with the direct pathway no longer being significant (p > .05). This provides support for Latin dance programs to have an effect on SPPB protocol and CRF.

Characterizing longitudinal change in accelerometry-based moderate-to-vigorous physical activity in the Hispanic Community Health Study/Study of Latinos and the Framingham Heart Study.

BACKGROUND: Physical activity promotes health and is particularly important during middle and older age for decreasing morbidity and mortality. We assessed the correlates of changes over time in moderate-to-vigorous physical activity (MVPA) in Hispanic/Latino adults from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL: mean [SD] age 49.2 y [11.5]) and compared them to a cohort of primarily White adults from the Framingham Heart Study (FHS: mean [SD] 46.9 y [9.2]). METHODS: Between 2008 and 2019, we assessed accelerometry-based MVPA at two time points with an average follow-up of: 7.6 y, SD 1.3 for HCHS/SOL, and 7.8 y, SD 0.7 for FHS. We used multinomial logistic regression to relate socio-demographic and health behaviors with changes in compliance with 2018 US recommendations for MVPA from time 1 to time 2 (remained active or inactive; became active or inactive) across the two cohorts. RESULTS: In HCHS/SOL mean MVPA was 22.6 (SD, 23.8) minutes at time 1 and dropped to 16.7 (19.0) minutes at time 2. In FHS Mean MVPA was 21.7 min (SD, 17.7) at time 1 and dropped to 21.3 min (SD, 19.2) at time 2. Across both cohorts, odds of meeting MVPA guidelines over time were about 6% lower in individuals who had lower quality diets vs. higher, about half in older vs. younger adults, about three times lower in women vs. men, and 9% lower in individuals who had a higher vs. lower BMI at baseline. Cohorts differed in how age, gender, income, education, depressive symptoms, marital status and perception of general health and pain associated with changes in physical activity. High income older Hispanics/Latino adults were more likely to become inactive at the follow-up visit as were HCHS/SOL women who were retired and FHS participants who had lower levels of education and income. Higher depressive symptomology was associated with becoming active only in HCHS/SOL women. Being male and married was associated with becoming inactive in both cohorts. Higher perception of general health and lower perception of pain were associated with remaining active only in FHS adults. CONCLUSIONS: These findings highlight potentially high-risk groups for targeted MVPA intervention.

The influence of Latino cultural values on the perceived caregiver role of family members with Alzheimer's disease and related dementias.

OBJECTIVES: We explored how Latino cultural values play a role in perceived caregiving experiences. DESIGN: We conducted a qualitative study that used individual, in-depth, semi-structured interviews with middle-aged and older Latinos who were primary caregivers of family members with Alzheimer's disease and related dementias (ADRD). The interview guide consisted of questions about participants' perceptions of family caregiving and interrelationships between the caregiver and care recipient. The interviews were recorded, translated, and transcribed verbatim. We performed direct content analysis. RESULTS: Participants were caregivers, 50-75 years old (n = 16), and the majority were female. We identified four cultural values that were salient to participants' caregiving experiences: (a) familismo, (b) fatalismo (c) marianismo, and (d) machismo. CONCLUSION: Latino cultural values influenced the role of caregiving and caregiving roles of family members with ADRD. Future research should consider these values as they affect different familial and health dynamics.

BAILA: A Randomized Controlled Trial of Latin Dancing to Increase Physical Activity in Spanish-Speaking Older Latinos.

BACKGROUND: Latinos are the fastest growing minority group of the older adult population. Although physical activity (PA) has documented health benefits, older Latinos are less likely to engage in leisure time PA than older non-Latino whites. Dance, popular among Latinos, holds promise as a culturally relevant form of PA. PURPOSE: To describe self-reported and device-assessed changes in PA as a result of a randomized controlled trial of BAILAMOS, a 4-month Latin dance program with a 4-month maintenance program, versus a health education control group. METHODS: Adults, aged 55+, Latino/Hispanic, Spanish speaking, with low PA levels at baseline, and risk for disability were randomized to the dance program (n = 167) or health education condition (n = 166). Data were analyzed using multilevel modeling with full information maximum likelihood. RESULTS: A series of multilevel models revealed significant time × group interaction effects for moderate-to-vigorous physical activity (MVPA), dance PA, leisure PA, and total PA. Exploring the interaction revealed the dance group to significantly increase their MVPA, dance PA, leisure PA, and total PA at months 4 and 8. Household PA and activity counts from accelerometry data did not demonstrate significant interaction effects. CONCLUSIONS: The study supports organized Latin dance programs to be efficacious in promoting self-reported PA among older Latinos. Efforts are needed to make dancing programs available and accessible, and to find ways for older Latinos to add more PA to their daily lives. CLINICAL TRIAL INFORMATION: NCT01988233.

Developmental disparities in sedentary time by period of the day among US youth: a cross-sectional study.

BACKGROUND: Definitive evidence shows sedentary time (ST) is an independent risk factor for chronic disease, irrespective of physical activity. Despite calls to limit youth ST, studies demonstrate a spike in ST at the transition from childhood to adolescence. Identifying periods of the day (e.g., before school, during school, afterschool, and evenings) during which ST is higher in adolescents vs. children-that is, specifying when within daily routines ST disparities emerge-may be important to inform intervention strategies, as periods of the day correspond with variations in setting and supervision. The purpose of this study was to examine device-assessed ST engagement by period of day and developmental stage in a nationally representative sample of United States youth. METHODS: Youth (N = 2,972 between 6-18 years) from the 2003-2004 and 2005-2006 waves of NHANES reported demographic variables and wore an accelerometer for seven consecutive days to determine ST. Linear regression analyses were applied to study associations between ST and developmental stage (childhood or adolescence) by period of the week and weekend days, while controlling for sex, race/ethnicity, annual family income, and body mass index. RESULTS: Adjusted linear regressions (p-values < 0.0001) showed that adolescents were more sedentary than children during school, afterschool, and weekday evening periods as well as all the weekend periods. However, during school (36.3 ± 7.3 vs. 28.2 ± 7.2 min/hour; b = -7.4 [-8.1, -6.6]) and afterschool periods (31.1 ± 7.7 vs. 22.7 ± 7.0 min/hour; b = -7.8 [-8.6, -7.0]) showed the largest weekly ST disparities by developmental stage. Overall, the during school and after school hours constitute most (during school = 35% and afterschool = 16%) of the weekly ST disparity between children and adolescents. CONCLUSIONS: Our data provide interventionists with estimates of the potential for ST reduction in each setting and period of the day among US adolescents. Future research should gather information about the barriers and facilitators of ST in adolescents by period of the day to help understand factors driving disparities.

Association of physical activity levels and brain white matter in older Latino adults.

OBJECTIVE: Investigate the associations between self-reported physical activity (PA) engagement and white matter (WM) health (i.e. volume, integrity, and hyperintensities) in older Latinos. DESIGN: Cross-sectional study with community-dwelling older adults from predominantly Latino neighborhoods. Participants: Thirty-four cognitively healthy older Latinos from two different cohorts. Measurements: Participants self-reported demographic information, PA engagement [Community Healthy Activities Model Program for Seniors (CHAMPS) Physical Activity Questionnaire for Older Adults] and magnetic resonance imaging (MRI). We used high-resolution three-dimensional T1- and T2-FLAIR weighted images and diffusion tensor imaging acquired via 3 T MRI. We performed a series of hierarchical linear regression models with the addition of relevant covariates to examine the associations between self-reported PA levels and WM volume, integrity, and hyperintensities (separately). We adjusted p-values with the use of the Benjamini-Hochberg's false discovery rate procedure. RESULTS: Higher reported levels of leisure-time moderate-to-vigorous PA were significantly associated with higher WM volume of the posterior cingulate (ß = 0.220, SE = 0.125, 95% CI 0.009-0.431, p = 0.047) and isthmus cingulate (ß = 0.212, SE = 0.110, 95% CI 0.001-0.443, p = 0.044) after controlling for intracranial volume. Higher levels of total PA were significantly associated with higher overall WM volume of these same regions (posterior cingulate: ß = 0.220, SE = 0.125, CI 0.024-0.421, p = 0.046; isthmus cingulate: ß = 0.220, SE = 0.125, 95% CI 0.003-0.393; p = 0.040). Significant p-values did not withstand Benjamini-Hochberg's adjustment. PA was not significantly associated with WM integrity or WM hyperintensities. CONCLUSION: Higher levels of PA, particularly higher leisure-time moderate-to-vigorous PA, might be associated with greater WM volume in select white matter regions key to brain network integration for physical and cognitive functioning in older Latinos. More research is needed to further confirm these associations.

The S.P.A.C.E Hypothesis: Physical Activity as Medium - Not Medicine - for Public Health Impact.

Most scientifically tested physical activity interventions end when research funding ends; interventions that last struggle to sustain benefits. We hypothesize that long-term public health impact will benefit from a shift in how interventionists conceptualize physical activity - from a form of medicine, of value for its innate health benefits, to a malleable medium, of value for the dynamic contexts it creates.

"My Parent's Body Is Sacred": Perspectives From Adult Latino Children About Brain Donation for Alzheimer Disease Research.

INTRODUCTION: Brain donation is a critical part of advancing research addressing Alzheimer disease and related dementias (ADRD). Studies on ADRD with an option for brain donation are reliant on family members to fulfill the research participant's plan for brain donation. Thus, family members play a pivotal role in increasing brain donation rates, particularly among under-represented groups. METHODS: This study examines knowledge, attitudes, and beliefs about brain donation for research among Latinos. Latino men (N=4) and Latina women (N=11) 18 years of age or older with a parental figure age 65 years and over were invited to participate in a focus group. RESULTS: Data analyses revealed 3 themes. Two themes focused on factors influencing a family's willingness to support brain donation: (a) social and cultural contexts, and (b) lack of knowledge and information about the brain donation process. The last theme provided recommendations for engaging older Latino adults in ADRD research and brain donation. DISCUSSION: Results suggest being inclusive of family members during all stages of the research process, from recruitment to dissemination. In addition, addressing information gaps among Latinos about the process and benefits of brain donation may help mitigate mistrust and misperceptions and increase participation rates in brain donation.

Long-Term Outcomes of 496 Anatomical Cementless Modular Femoral Stems: Eleven to Twenty Years of Follow-Up.

BACKGROUND: The aim of the study is to assess the long-term outcomes of this specific stem (anatomical cementless modular stem ESOP), to review the survivorship, complication rate, and radiographic and clinical outcomes. METHODS: Descriptive and analytical retrospective longitudinal observational study of patients was operated on total hip arthroplasty between 1998 and 2007. Four hundred ninety-six prostheses corresponding to 447 patients were reviewed, mean age was 65.8 years (standard deviation [SD] ±11.6 years), and median follow-up time was 13.4 years (range 1-20). The most used cups were cementless (75.8%). The most frequent friction pairs were metal-polyethylene (53.1%) and ceramic-polyethylene (24.2%). Main variables analyzed were stem survival, subsidence, coronal orientation, osteolysis, reintervention, and Oxford Hip Score. RESULTS: From 496 implants, there were 22 lost to follow-up (4.4%). Stem revision was performed in 51 patients: 26 periprosthetic joint infections (2-stage revision), 16 periprosthetic fractures, and 8 one-stage revisions (6 real aseptic loosening with negative culture after revision). The stem survivorship at more than 15 years for any reason was 89.2% and for aseptic loosening 97.97%. No specific complications were found due to modularity. The mean subsidence and orientation was 2.06 mm (SD ±5.11 mm) and 0.41° varus (SD ±2.20°) respectively. Subsidence >5 mm or varus >5° was associated with a higher revision rate. Osteolysis was found in 110 patients (zone I = 79, VII = 57), associated with zirconium-polyethylene, without relationship to the stem revision rate or Oxford Hip Score. CONCLUSION: To our knowledge, this study represents the largest series of this stem, revealing an excellent survival rate and long-term clinical outcomes similar to the best results of classical cementless stems published in the literature.

Productive, nutritional, and metabolic performance of Chino Santandereano cattle receiving different degrees of protein-energy supplementation.

Cattle of Colombian creole breed Chino Santandereano in the raising phase were subjected to stabling for 100 days in order to determine the productive, nutritional, and metabolic capacity when exposed to different degrees of protein-energy supplementation. Sixteen whole males with an initial mean weight of 377.69 ± 16.55 kg were used in completely randomized delineation with four treatments and four repetitions per treatment, as follows: UNS, not supplemented; low, supplemented with amounts relative to 0.5% of body weight; medium, supplemented with amounts relative to 1.0% of the live weight; and high, supplemented with amounts relative to 1.5% of body weight. At the end of each experimental period, the animals were weighed, and samples of feed, feces, blood, and urine were collected to determine the performance, consumption, and digestibility of the nutritional components, and nitrogen balance. In the greater performance, consumption, and digestibility of DM, OM, C-NFCP, EE, and NFC, the concentration of ureic nitrogen in blood and urine (P <0.05) was observed in supplemented animals when contrasted with UNS. Bovine Chinese Santandereano presents high productive, nutritional, and metabolic potential as a response to high levels of protein-energy supplementation.

Representation of Older Latinxs in Cohort Studies at the Rush Alzheimer's Disease Center.

The Rush Alzheimer's Disease Center (RADC) conducts 5 harmonized prospective clinical-pathologic cohort studies of aging - with 1 study, the Latino Core, focused exclusively on Latinxs, 2 studies consisting of mostly non-Latinx whites, and 2 studies of mostly non-Latinx blacks. This paper contextualizes the Latino Core within the other 4 harmonized RADC cohort studies. The overall aim of the paper is to provide information from the RADC, so that researchers can learn from our participants and procedures to better advance the science of Alzheimer's disease and related dementias in Latinxs. We describe an annual clinical evaluation that assesses risk factors for Alzheimer's dementia among older adults without known dementia at enrollment. As all RADC cohort studies offer brain donation as a part of research participation, we discuss our approach to brain donation and subsequent participant decision-making among older Latinxs. We also summarize baseline characteristics of older Latinxs across the 5 RADC cohort studies in relation to the baseline characteristics of non-Latinx blacks and non-Latinx whites. Finally, we outline challenges and considerations as well as potential next steps in cognitive aging research with older Latinxs.

Fit and Strong! Plus: Twelve and eighteen month follow-up results for a comparative effectiveness trial among overweight/obese older adults with osteoarthritis.

This comparative effectiveness trial compared the longer-term effectiveness (12 and 18 months) of the standard Fit & Strong! physical activity program to Fit & Strong! Plus, which combined physical activity and dietary weight loss. Outcomes were weight, diet quality, physical activity, osteoarthritis symptoms, performance measures, and anxiety/depression. In this study, 413 overweight/obese participants with OA, ≥60 years old and primarily African American, were randomly assigned to Fit & Strong! (F&S!) or Fit & Strong! Plus (F&S! Plus), with outcomes assessed at 2, 6, 12, and 18 months. 356 (86%) participants completed the 18-month visit. Compared with participants randomized to standard F&S!, F&S! Plus participants maintained longer-term benefits at 12 months in weight (mean change ± SE: -1.7 ± 0.3 kg for F&S! Plus vs -0.9 ± 0.3 kg for F&S!, p = 0.049), BMI (-0.6 ± 0.1 vs -0.3 ± 0.1 kg/m2, p = 0.04), waist circumference (-2.7 ± 0.6 vs -0.4 ± 0.6 cm, p = 0.004), and lower extremity strength (1.6 ± 0.2 vs 1.0 ± 0.2 chair stands, p = 0.046). At 18 months, F&S! Plus participants showed improved lower extremity strength (1.4 ± 0.2 vs. 0.7 ± 0.2 chair stands, p = 0.045. African American older adults in the F&S! Plus arm showed sustained modest improvements in weight, waist circumference, and lower extremity strength at 12 months and in lower extremity strength at 18 months compared to F&S!. Implications for the translation of evidence-based programs into community settings to support healthy behaviors in older adults are discussed.

Sources of Caregiving Burden in Middle-Aged and Older Latino Caregivers.

OBJECTIVE: We aimed to identify sources of caregiver burden in middle-aged and older Latino caregivers of people with Alzheimer disease and related dementia (ADRD). METHODS: Participants were recruited through an agreement with the Rush Alzheimer's Disease Center Clinic Data Repository. We conducted semistructured interviews with 16 middle-aged and older Latinos who were the primary caregiver for a family member diagnosed with ADRD. The interview guide consisted of questions and probes to capture participants' perceptions of family caregiving. Direct content analysis was performed. RESULTS: Participants were aged 50 to 75 years (n = 16) and a majority female (n = 12). The sources of burden identified were (1) caregiver responsibilities, (2) caregiving-related health decline, (3) lack of support, (4) financial status, (5) vigilance, and (6) concerns about the future. CONCLUSIONS: The influence of gender roles seemed to play a role in caregivers' perceptions of sources of burden, especially on caregiver responsibilities and perceptions of lack of support. Latinos cultural values such as familismo and marianismo likely reinforced gender disparities in family caregiving.

Exercise and Academic Performance Among Children With Attention-Deficit Hyperactivity Disorder and Disruptive Behavior Disorders: A Randomized Controlled Trial.

PURPOSE: To examine effects of a 10-week after-school physical activity (PA) program on academic performance of 6- to 12-year-old African American children with behavior problems. METHODS: Participants were randomized to PA (n = 19) or sedentary attention control (n = 16) programs. Academic records, curriculum-based measures, and classroom observations were obtained at baseline, postintervention, and/or follow-up. Mixed models tested group × time interactions on academic records and curriculum-based measures. One-way analysis of variance or Kruskal-Wallis tested for differences in postintervention classroom observations. RESULTS: Intent-to-treat analyses demonstrated a moderate effect within groups from baseline to postintervention on disciplinary referrals (PA: d = -0.47; attention control: d = -0.36) and a null moderate effect on academic assessments (PA: d = 0.11 to 0.36; attention control: d = 0.05 to 0.40). No significant group × time interactions emerged on direct academic assessments (all Ps ≥ .05, d = -0.23 to 0.26) or academic records (all Ps ≥ .05, d = -0.28 to 0.16). Classroom observations revealed that intervention participants were off-task due to moving at twice the rate of comparative classmates (F = 15.74, P < .001) and were off-task due to talking 33% more often (F = 1.39, P = .257). CONCLUSION: Academic outcome improvements were small within and between groups and did not sustain at follow-up. Academic benefits of after-school PA programs for children with attention-deficit hyperactivity disorder and/or disruptive behavior disorders were smaller than neurobiological, behavioral, and cognitive outcomes as previously reported.

Nutritional strategies for heifers under grazing system: productive and nutritional performance, metabolic profile and ovarian activity.

The objective of this study was to evaluate the effects of nutritional strategies on productive and nutritional performance, metabolic profile, and ovarian activity in heifers under grazing in the tropics in Brazil. Forty Nellore heifers averaging 8.5 ± 0.06 months and 248.6 ± 3.3 kg body weight (BW) were distributed in a completely randomized 2 × 2 factorial design with four treatments and ten replicates. The evaluated strategies consisted of different amounts of energetic-protein supplement: (1) 4 g/kg of BW of supplement in the pre-weaning and post-weaning; (2) 4 g/kg of BW of supplement pre-weaning and 6 g/kg in the post-weaning; (3) 6 g/kg of BW of supplement in the pre-weaning and 4 g/kg of BW in the post-weaning and; (4) 6 g/kg of BW of supplement in the pre-weaning and post-weaning. Crude protein (CP) and organic matter (OM) intake were increased (P < 0.05) by increasing the amounts of supplement in the post-weaning. Additionally, increasing supplement amounts in the post-weaning increased the digestibility of OM and CP (P < 0.05). Means insulin and glucose concentrations were greater (P < 0.05) for heifers that received higher amounts of supplement in the post-weaning. Average daily gain and fat thickness in the rump were increased (P < 0.05) by increasing supplement amounts in the post-weaning. Amounts of supplement did not influence the body growth of heifers. However, follicular number, diameter, and progesterone concentration were greater (P < 0.05) for heifers that received higher amounts of supplement in the post-weaning. In summary, increasing supplement amounts in the post-weaning improve the performance, energy and metabolic status, and ovarian activity in beef heifers under grazing in the tropics. Due to higher intake of supplement, the heifers receiving 6 g/kg of BW post-weaning had greater responses, independently of the supplement amount received pre-weaning.

Multiple Physiological Signals Fusion Techniques for Improving Heartbeat Detection: A Review.

This paper presents a review of the techniques found in the literature that aim to achieve a robust heartbeat detection from fusing multi-modal physiological signals (e.g., electrocardiogram (ECG), blood pressure (BP), artificial blood pressure (ABP), stroke volume (SV), photoplethysmogram (PPG), electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG), among others). Techniques typically employ ECG, BP, and ABP, of which usage has been shown to obtain the best performance under challenging conditions. SV, PPG, EMG, EEG, and EOG signals can help increase performance when included within the fusion. Filtering, signal normalization, and resampling are common preprocessing steps. Delay correction between the heartbeats obtained over some of the physiological signals must also be considered, and signal-quality assessment to retain the best signal/s must be considered as well. Fusion is usually accomplished by exploiting regularities in the RR intervals; by selecting the most promising signal for the detection at every moment; by a voting process; or by performing simultaneous detection and fusion using Bayesian techniques, hidden Markov models, or neural networks. Based on the results of the review, guidelines to facilitate future comparison of the performance of the different proposals are given and promising future lines of research are pointed out.

Positive and Negative Evidence Accumulation Clustering for Sensor Fusion: An Application to Heartbeat Clustering.

In this work, a new clustering algorithm especially geared towards merging data arising from multiple sensors is presented. The algorithm, called PN-EAC, is based on the ensemble clustering paradigm and it introduces the novel concept of negative evidence. PN-EAC combines both positive evidence, to gather information about the elements that should be grouped together in the final partition, and negative evidence, which has information about the elements that should not be grouped together. The algorithm has been validated in the electrocardiographic domain for heartbeat clustering, extracting positive evidence from the heartbeat morphology and negative evidence from the distances between heartbeats. The best result obtained on the MIT-BIH Arrhythmia database yielded an error of 1.44%. In the St. Petersburg Institute of Cardiological Technics 12-Lead Arrhythmia Database database (INCARTDB), an error of 0.601% was obtained when using two electrocardiogram (ECG) leads. When increasing the number of leads to 4, 6, 8, 10 and 12, the algorithm obtains better results (statistically significant) than with the previous number of leads, reaching an error of 0.338%. To the best of our knowledge, this is the first clustering algorithm that is able to process simultaneously any number of ECG leads. Our results support the use of PN-EAC to combine different sources of information and the value of the negative evidence.

Nutritional planning for Nellore heifers post-weaning to conception at 15 months of age: performance and nutritional, metabolic, and reproductive responses.

The objective of this study was to evaluate the effects of strategic supplementation in the dry period and dry/rainy transition period on the performance and nutritional, metabolic, and reproductive responses of Nellore heifers grazing Urochloa decumbens. Forty-eight Nellore heifers with age and body weight (BW) of eight months and 235 ± 3.3 kg, respectively, were used. The experimental design was a completely randomized design, with four treatments, all with 12 replications. The evaluated strategies were as follows: low supplementation (LOHI; 0.2% of BW/heifer/day) in the first 90 days and high supplementation (0.6% of BW/heifer/day) in the 90 days thereafter; average supplementation (AVER) with 0.4% of BW/heifer/day for 180 days; high supplementation (HILO; 0.6% of BW/heifer/day) in the first 90 days and low supplementation (0.2% of BW/heifer/day) in the 90 days thereafter; only mineral mix (MM) ad libitum during the 180 days. Data were evaluated using orthogonal contrasts. Supplementation improved the performance of the animals during of dry period (P < 0.05) and dry/rainy transition period (P < 0.05). Supplemented animals had higher longissimus muscle area (LMA) and subcutaneous fat thickness (SFT) at the end of the experiment (P < 0.05). Multiple supplementation increased intake of dry matter (DM), organic matter (OM), and crude protein (CP) in kg/day throughout the experiment. The supplementation increased the digestibility of DM, OM, CP, apNDF, and TDN (P < 0.05). Serum urea nitrogen (SUN), glucose (GLUC), insulin (INS), and progesterone (PROG) were higher in supplemented heifers (P < 0.05). Supplementation reduced the concentrations of non-esterified fatty acids (NEFA) (P < 0.05) and increased conception rate (P < 0.05). In summary, the supplementation strategies adopted in this study improve the performance, metabolic status, and carcass traits of heifers under grazing, allowing an improvement in the conception rate of 15-month-old Nellore heifers.