Authors: Kaela Hierholzer , Robert Briggs , Michael Tolston , Nicholas Mackowski , Jason Eckerle , Maegan O’Connor , Kristyn Barrett , Roger Smith , Adam Strang

In Life Sciences, Psychology, Biology

By Science Publishing Group

The collection of heart rate variability (HRV) for health and performance observations have become prominent. However, each wearable device has proprietary algorithms that govern methods and timing of HRV capture and subsequent analysis. The purpose of this study was to evaluate HRV metrics taken from three, commonly used commercial wearables, and identify reliability and relationships to one another over time. Methods: Twenty-five subjects (18 males; 7 females) with ages ranging from 23 to 41 years (32.70 ± 4.65 years) were included in this study. These subjects were participants in a 12-week exercise intervention study. Each subject was equipped with a Whoop Strap (v2.0), the Garmin Fenix 5 Smartwatch and chest strap, and the Omegawave chest strap and sensor. Statistical Analysis: Between and within-subject correlations were calculated as well as average correlations, descriptive and inferential statistics, and the resultant z-score, which was transformed back into a correlation. Intraclass correlation coefficients (ICC) were calculated. Finally, linear mixed models were used to evaluate trends in HRV. Results: Within-subject correlations (0.24 ± 0.27) were lower than between-subjects correlations (0.54 ± 0.43), t (35) = -4.02, p < 0.001. Garmin HRV Stress, Whoop RMSSD, Omegawave SDNN, and Omegawave RMSSD yielded an ICC between 0.65 and 0.75. Garmin All-day stress, Garmin prior all-day stress, and Omegawave LF/HF yielded an ICC of 0.30 and 0.37. To test the effects of day of the week on HRV, we fitted linear mixed models to HRV metrics from three of the identified communities related to ICC: Omegawave RMSSD (moderate to high ICC), Omegawave LF/HF (low to moderate ICC), and Whoop recovery score (very low ICC). There was a main effect of gender on Omegawave RMSSD (p = 0.020) and a negative effect of day of the week (p = 0.030). Day of the week was the only significant predictor of Whoop recovery score (p < 0.001). Conclusion: The correlations of HRV values remain more consistent when assessed at similar times of the day, rather than being device dependent. Regardless of which wearable device is considered, HRV measures should be collected at a specific time each day for the best reliability. When creating an individualized or group exercise program, the human performance specialist should be aware that fatigue may become increasingly evident during the course of each week (e.g. individuals demonstrably fatigued by Friday may exhibit physiological indicators of relative recovery by Monday).

Authors: Iliya Bila Auta , Ibrahim Ikara Abdulkarim , Olubajo Olumide Olu

In Life Sciences, Biology

By Science Publishing Group

The aim of this research was to investigate the effect of replacing eggshell powder (ESP) with date palm seed pod ash (DPSA), curing age and cement replacement on the properties of cement blended with ESP and/or DPSA on the water consistence, setting times and mortar compressive strengths according to ASTM standards. DPSA was produced by calcining date palm seed pod at 590°C for 8 hours followed by 630°C for 3 hours and the resultant ash was ground and sieve with a 90-micron sieve. Portland limestone cement CEM II 42.5R was employed and replaced by eggshell powder and DPSA at various proportions between 0 – 12.5 wt.% at interval of 2.5 wt.% for consistence and setting times whereas cement replacement was varied between 0 -8 wt.% at interval of 2 wt.% for the mortar compressive strength by using 50 mm cubes with a mixing ratio 1:3:5 (water, binder and sand). DPSA revealed high silica content of 42.75 wt.% with SiO2+Al2O3+Fe2O3 < 70% (45.38 wt.%) and hence may not be considered as a good pozzolana whereas ESP revealed a high lime content of 55.45 wt.% and considered a filler respectively using X-ray fluorescence spectrometer. Results indicated an increase in the water consistence for DPSA cement blend in comparison with control which related to either presence of unburnt carbon, clinker diminution or formation of magnesium hydroxide as a protective layer. Most of the cement blends experienced a diminution in the setting time compared to control except for cement blended with higher DPSA content. The accelerated and retarded setting times could possibly be due to available lime which favors ettringite instead of monosulfate and unburnt carbon present resulting in high water demand. The compressive strengths of both the control and cement experienced increments as curing age progressed with most of the blends exhibiting enhanced strength especially at the later stage at 28 and 60 days in comparison with control PLC. The reason for the enhanced strength at the later stage despite clinker diminution could be attributed to pozzolanic reaction between silica present in DPSA coupled with the available lime present in ESP. The optimal cement replacement of 4 wt.% was observed beyond which cement blends produced slightly lower strength in comparison with control owing to clinker diminution effect and higher water demand due to unburnt carbon present.

Authors: Ogbutor Udoji Godsday , Olisa Chisom Kingsley , Ephraim Chukwuemeka , Kizito Bright , Ezunu Emmanuel , Nworah Awele Maria , Nwangwa Eze Kingsley

In Life Sciences, Biology

By Science Publishing Group

Background: Consequent upon the increasing pressure on health system created by growing population of older adults, attention has been channeled to ways to smoothen the aging process among older adults including studying on their physical activity (PA), physical function (PF) and neighborhood environment adaptation (NEA). This study aimed to determine the level and interrelationships between PA, PF and NEA among older adults dwelling in Asaba, Delta State, Nigeria. Methodology: This is a cross sectional study involving 150 older adults (56% females; mean age = 72.57±6.32 years) consecutively recruited from communities in Asaba, Delta State, Nigeria. The International Physical Activity Questionnaire, the Physical Function Activity Scale (SF-36) and Physical Activity Neighborhood Environment scale in Nigeria (PANES-N) were used to assess physical activity, physical function and neighborhood environment adaptation among the participants respectively. Data was analyzed using frequency counts, percentages, mean, standard deviation and spearman’s correlation test at alpha level of 0.05. Results: The mean total of PA, PF, and NEA scores were 1324±1124.35MET-min/week (adequate), 60.58±17.44 (dependent), 2.32±0.27 (moderate) respectively. PF had direct correlation with PA (rho=0.69; p=

Authors: Mohamed Abdel-Fatah Abo-Farw , Wael Mohamed Nagy , Sherief Mohamed Zayed , George Ezaat Younan , Rehab Fawzy Ismail

In Life Sciences, Biology

By Science Publishing Group

This study aimed to evaluate the effect of the litter size (LS) category on the reproductive performance of nulliparous (NP) and second-parous (SP) NZW rabbits and the performance of their offspring. A total of 39 NP and 33 SP doe rabbits were divided into low (LLS, &#60;7) and high (HLS, ≥7) after parturition. Reproductive measurements of each LS category and doe type were determined. The results show LS of 3-8 and 4-10 NP and SP, respectively. Doe rabbits with 6 LS show the highest distribution. Doe body weight at mating and from mating to parturition was higher (P&#60;0.0001) for HLS than LLS, and SP than NP. Kit weight at birth and weaning, LS and viability were higher in HLS than in LLS does. At weaning, LS was higher (P&#60;0.0001) in SP than NP. Levels of P4 at mid-pregnancy (P&#60;0.001) were higher in HLS than in LLS, and in SP than in NP. In conclusion, a high litter size category (≥7/doe) was obtained from heavier NP or SP doe rabbits (LBW around 3 kg) and from second-parous compared with nulliparous does, with near similarity in conception rate of does. Weight and viability rate at birth and weaning as well as plasma progesterone level at mid-pregnancy were higher for does with high than low litter size category. In conclusion, body weight and parity may have a significant role in improving the litter size of doe rabbits, which may be useful in breeding and managerial programs to increase the economic value of rabbit production.

Authors: Nguyen Trung Dung , Bui Thi Thu Hoa , Nguyen Tuan Anh

In Life Sciences, Biology

By Science Publishing Group

The integrated pest management (IPM) program was implemented in 2015 and 2016 in the province of Soc Trang. The research question is whether Artificial Neural Networks (ANNs) with pattern recognition can be useful for classifying farmers for a more realistic assessment of the performance of an IPM program. To evaluate the performance of the program, three datasets were collected, including dataset S1i with 450 farmers interviewed before conducting the IPM program, S2i with 250 farmers in the pilot area (communes/villages), and S3i with 50 farmers outside the pilot area. The conventional statistical assessment method (CAM) assumes that all farmers in each dataset behave similarly related to IPM concerning the seed, spray frequency, and dosage. This means that the original datasets were used to estimate the required statistical parameters. Thus, the traditional approach wastes information hidden in all surveyed data. Based on ANN, we can classify and determine the percentage of farmers in the six groups or the level of IPM adoption (3 neutral groups and 3 active groups) as well as the actual benefits of the IPM program. ANN-based assessment method (ANN-M) has been proven to be better than CAM in evaluating the performance of the project.

Authors: Gary D. James , Linda M. Gerber

In Life Sciences, Biology

By NCBI Pubmed

Human biologists have been examining arterial blood pressure since they began studying the effects of the environment and culture on the health of diverse populations. The Korotkoff auscultatory technique with a trained observer and aneroid sphygmomanometer is the method of choice for blood pressure measurement in many bioanthropological field contexts. Korotkoff sounds (the first and fifth phases) are the preferred determinants of systolic and diastolic pressure, even in infants, children, pregnant women, and the elderly. Training of observers, positioning of individuals, and selection of cuff size are all essential for obtaining standardized measurements. Automatic electronic devices are increasingly being used for blood pressure measurement in human biological studies. The automatic monitors often use the oscillometric method for measuring pressure, but must be validated before use. The emergence of automatic ambulatory blood pressure monitors has opened another avenue of research on blood pressure in human biology, where allostasis and circadian responses to environmental change and real life behavioral challenges can be defined and evaluated, largely because there is now the ability to make multiple measurements over time and in varying contexts. Stand-alone automatic monitors can also be substituted for manual auscultated readings in field contexts, although in studies where participants measure their own pressure, education about how the devices work and protocol specifics are necessary. Finally, computer-driven plethysmographic devices that measure pressure in the finger are available to evaluate short-term reactivity to specific challenges.

Authors: Bailey A.T. Weatherbee , Tongtong Cui , Magdalena Zernicka-Goetz

In Biology

By NCBI Pubmed

Early human post-implantation development involves extensive growth combined with a series of complex morphogenetic events. The lack of precise spatial and temporal control over these processes leads to pregnancy loss. Given the ethical and technical limitations in studying the natural human embryo, alternative approaches are needed to investigate mechanisms underlying this critical stage of human development. Here, we present an overview of the different stem cells and stem cell-derived models which serve as useful, albeit imperfect, tools in understanding human embryogenesis. Current models include stem cells that represent each of the three earliest lineages: human embryonic stem cells corresponding to the epiblast, hypoblast-like stem cells and trophoblast stem cells. We also review the use of human embryonic stem cells to model complex aspects of epiblast morphogenesis and differentiation. Additionally, we propose that the combination of both embryonic and extra-embryonic stem cells to form three-dimensional embryo models will provide valuable insights into cell-cell chemical and mechanical interactions that are essential for natural embryogenesis.