bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allometric Grip Strength Norms for Children of Hawaiian Lineage
Authors: Kocher Morgan H. , Romine Rebecca K. , Stickley Christopher D. , Morgan Charles F. , Resnick Portia B. , Hetzler Ronald K. 
Published: February 2017

Abstract
Kocher, MH, Romine, RK, Stickley, CD, Morgan, CF, Resnick, PB, and Hetzler, RK. Allometric grip strength norms for children of Hawaiian lineage. J Strength Cond Res 31(10): 2794–2807, 2017—The purpose of the study was to determine allometric exponents for scaling grip strength in children that effectively control for body mass (BM) and stature (Ht) and to develop normative grip strength data for Hawaiian children. One thousand, four hundred thirty-seven students (754 boys) from a rural community in Hawaii participated in this 5-year study, resulting in 2,567 data points. Handgrip strength, BM, and Ht were collected every year. Multiple log-linear regression was used to determine allometric exponents for BM and Ht. Appropriateness of the allometric model was assessed through regression diagnostics, including normality of residuals and homoscedasticity. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. Allometric exponents for BM and Ht were calculated separately for each age group of boys and girls to satisfy the common exponent and group difference principles described by Vanderburgh. Unscaled grip strength had moderate to strong positive correlations with BM and Ht (p ≤ 0.05 for all) for all age groups. Ratio-scaled handgrip strength had significant moderate to strong negative correlations with BM (p ≤ 0.05 for all) and, to a lesser extent, Ht (p ≤ 0.05 for 8- to 12-year-old boys; p ≤ 0.05 for 8- to 12- and 14-year-old girls). Correlations between allometrically scaled handgrip strength and BM and Ht were not significant and approached zero. This study was the first to allometrically scale handgrip strength for BM and Ht in Hawaiian children. Allometric scaling applied to grip strength provides a useful expression of grip strength free of the confounding influence of body size.
Reliability of Zephyr Bioharness and Fitbit Charge Measures of Heart Rate and Activity at Rest, During the Modified Canadian Aerobic Fitness Test, and Recovery
Authors: Nazari Goris , MacDermid Joy C. , Sinden Kathryn E. , Richardson Julie , Tang Ada 
Published: February 2017

Abstract
Nazari, G, MacDermid, JC, Sinden, KE, Richardson, J, and Tang, A. Reliability of Zephyr Bioharness and Fitbit Charge measures of heart rate and activity at rest, during the modified Canadian Aerobic Fitness Test, and recovery. J Strength Cond Res 33(2): 559–571, 2019—The purpose of this study was to determine the intrasession and intersession reliability of Zephyr Bioharness (ZB) and Fitbit Charge variables in both healthy men and women at rest, during the Modified Canadian Aerobic Fitness Test (mCAFT), and throughout recovery. Stratified convenience and snowball sampling were used to recruit 60 participants (30 women, 48 ± 15 years) and (30 men, 48 ± 15 years) from McMaster University student, staff, and faculty population. At rest, intrasession average heart rate (b·min−1). Intraclass correlation coefficients (ICCs) and Standard Error of Measurement [SEM] for Zephyr ranged from (0.94–0.97) [1.17–1.70] to (0.92–0.97) [1.45–2.10] for Fitbit Charge. During the mCAFT, the Zephyr ICCs and (SEM) ranged from 0.31–0.99 (1.28–8.10) to 0.45–0.99 (1.45–8.71) for the Fitbit Charge. Throughout the recovery, the ICCs and (SEM) ranged from 0.44–0.98 (1.26–10.47) to 0.45–0.98 (1.15–11.90) for Zephyr and Fitbit devices, respectively. At rest, intersession ICCs (SEM) for Zephyr and Fitbit ranged from 0.90–0.94 (1.73–2.37) to 0.88–0.94 (1.83–2.67), respectively. At mCAFT, the Zephyr ICCs (SEM) ranged from 0.91–0.97 (3.12–4.64) to 0.85–0.98 (3.28–4.88) for the Fitbit. Throughout the recovery, the ICCs (SEM) ranged from 0.93–0.97 (2.65–4.66) to 0.76–0.91 (3.17–4.67) for Zephyr and Fitbit devices, respectively. To conclude, both the ZB and Fitbit Charge devices demonstrated excellent reliability measures throughout the 3 phases. The findings from our study add to the existing pool of literature regarding the reliability parameters of wearable devices and suggest that stable and consistent measures of heart rate and physical activity can be obtained using ZB and Fitbit Charge devices among healthy male and female participants at rest, during a standardized submaximal fitness test (mCAFT), and throughout recovery.
Performance Characteristics of Blended Cementitious Systems Incorporating Chemically Transformed Rice Husk Ash
Authors: Prasittisopin L. , Trejo D. 
Published: February 2017

Abstract
Research has indicated that an as-received rice husk ash (AR-RHA) can be chemically transformed by being treated with alkali solutions. Such a chemical transformation could result in an increase in silicate ion concentration, reduction of particle size, and elimination of the cellular morphology. In this paper, the early- and later-age performance was investigated including flowability, setting time, chemical shrinkage (CS), compressive strength, hardened porosity, and apparent chloride ion permeability (Da). The process provides several benefits to the rice husk ash (RHA) blended cementitious system, including faster setting, increased early-age compressive strength, reduced porosity, and decreased Da. These benefits occurred due to the physico-chemical mechanisms of better particle packing from smaller RHA particles, the NaOH addition, and the increased silicate ion concentration in solution. This chemical transformation method is promising and can make RHA a more user-friendly supplementary cementing material (SCM), enhancing its likelihood of being utilized.
Simulation of Microtextured Surfaces in Starved EHL Contacts Using Commercial FE Software
Authors: Marian Max , Weschta Martin , Tremmel Stephan , Wartzack Sandro 
Published: February 2017

Abstract
In order to improve the lubricating conditions and thus realize a reduction of friction and wear, the surfaces of contacting bodies in lubricated tribological contacts can be microtextured. Although this approach has already reached industrial applications for lower loaded contacts, it is still in basic research for higher loaded contacts, where elastic deformation plays a significant role. In the past, it was common in theoretical studies to assume a fully flooded condition for the inlet to the contact. However, in reality a lubricant contact may suffer from starvation due to high speeds, highly viscous lubricants, or limited lubricant supply. This article presents an efficient straightforward approach to compute starved microtextured elastohydrodynamic contacts based on a full-system approach and using commercial FE software. The numerical study on starvation is realized by shifting the position of the inlet meniscus toward the contact zone combined with the use of an appropriate cavitation model. Therefore, negative pressures are penalized by reducing the lubricant's density, respectively its volume or mass fraction, with a penalty term. First, the implementation for the steady-state smooth-surface problem as well as the impact of decreasing lubricant supply on the film thickness are discussed as a reference case. Special is paid to proving suitability and validity of the used cavitation model for starvation problems. Subsequently, the influence of different degrees of starvation on film thickness and pressure distribution for a microtextured time-dependent demonstrator case is illustrated.
Tribological Behavior of Oil-Lubricated Laser Textured Steel Surfaces in Conformal Flat and Non-Conformal Contacts
Authors: Kovalchenko A. M. , Erdemir A. , Ajayi O. O. , Etsion I. 
Published: February 2017

Abstract
Changing the surface texture of sliding surfaces is an effective way to manipulate friction and wear of lubricated surfaces. Having realized its potential, we have done very extensive studies on the effects of laser surface texturing (LST, which involves the creation of an array of microdimples on a surface) on friction and wear behavior of oil-lubricated steel surfaces in the early 2000s. In this paper, we reviewed some of our research accomplishments and assessed future directions of the laser texturing field in many diverse industrial applications. Our studies specifically addressed the impact of laser texturing on friction and wear of both the flat conformal and initial non-conformal point contact configurations using a pin-on-disk test rig under fully-flooded synthetic oil lubricants with different viscosities. Electrical resistance measurement between pin and LST disks was also used to determine the operating lubrication regimes in relation to friction. In conformal contact, we confirmed that LST could significantly expand the operating conditions for hydrodynamic lubrication to significantly much higher loads and slower speeds. In particular, with LST and higher viscosity oils, the low-friction full hydrodynamic regime was shifted to the far left in the Stribeck diagram. Overall, the beneficial effects of laser surface texturing were more pronounced at higher speeds and loads and with higher viscosity oil. LST was also observed to reduce the magnitude of friction coefficients in the boundary regime. For the non-conformal contact configuration, we determined that LST would produce more abrasive wear on the rubbing counterface compared to the untreated surfaces due to a reduction in lubricant fluid film thickness, as well as the highly uneven and rough nature of the textured surfaces. However, this higher initial wear rate has led to faster generation of a conformal contact, and thus transition from the high-friction boundary to lower friction mixed lubrication regime, resulting in a rapid reduction in the friction coefficient with increased ball wear. Higher density of LST, lower oil viscosity, and hardness of counterface steel surface facilitate an increase of the initial wear, which promotes friction reduction. This phenomenon can be beneficial if the initial accelerated wear on the counterface is acceptable in intended applications. This paper summarizes our experimental investigation of the effect of LST on friction properties and lubrication regime transitions in a unidirectional sliding contact.
Design and Tribological Performance of Textured Surfaces
Authors: Sedlaček M. , Podgornik B. 
Published: February 2017

Abstract
The aim of this work was to show that surface texturing could be regarded as ordered roughness, and therefore designed with the use of roughness parameters. By knowing which surface topography and especially which surface roughness parameters result in lower friction, we were able to select proper surface texturing parameters, and thus properly design the surface for given contact conditions. For this investigation, steel samples were laser surface textured in the shape of channels and dimples with different spacing between the channels/dimples. The experimental results performed on grooved and dimpled surfaces under lubricated sliding contact confirmed that the parameters Ssk and Sku can be used to design the surface texturing, where a higher value of Sku and more negative Ssk lead to lower friction. It was also shown that dimple texturing results in more favorable roughness parameters and consequently in better tribological behavior.
Influence of Different Micro-Imprints to Fatigue Life of Components
Authors: Tomazincic D. , Sedlacek M. , Podgornik B. , Klemenc J. 
Published: February 2017

Abstract
To improve tribological properties of components, different kinds of textures are added to their surfaces. Although the added imprints or craters are only few tens of micrometers wide and a few micrometers deep, they form an initial crack from which a fatigue crack may propagate. In this article, a numerical approach for calculating the fatigue life of a body with present micro-imprints with standard finite-element software will be presented. The objective is to show how the imprint shape and its manufacturing process influences the fatigue life. The considered specimens are round bodies that were made from Boehler K890 microclean cold-working steel. Three shapes of the imprints are studied: the imprints produced by a Vickers pyramid and a Rockwell cone and a half-spherical crater void produced by a laser device. The flat-surface round body served as a reference. The imprint shape and its manufacturing process is also considered. For this reason, a simulation of impression of Vickers and Rockwell indenters is simulated first, which is followed by a numerical fatigue-life prediction. In this manner, the residual stresses from the imprinting process are considered during the fatigue-life prediction. For the laser-induced craters and the reference body, only the fatigue life is numerically predicted. Because the material inhomogeneities are much smaller than the geometrical ones, the calculated fatigue lives for different texturing represent the fatigue-life reduction caused by the applied textures. To validate the presented numerical approach, the calculated fatigue lives are compared to the experimentally determined.
Effect of Heating and Mold Temperature on the Mechanical Properties and Microstructure of B1500HS Boron Steel
Authors: Li H. , Wang C. , He L. , Zhang C. 
Published: February 2017

Abstract
To know the effect of the heating temperature and the temperature of mold surface on the mechanical properties and microstructure of B1500HS steel, and supply some practical guides for the components with the distributed microstructure and mechanical properties, B1500HS steel sheets, heated at different austenitization temperatures (870°C, 900°C, 930°C, and 960°C), were formed in hot stamping tools with the different mold temperatures (100°C, 200°C, 300°C, and 400°C). The strength of hot stamping parts was tested by the uniaxial tensile experiment. Moreover, the microstructure, fractography, and micro-hardness of hot stamping parts were measured to evaluate the effect of austenitization temperature and mold temperature on the microstructure and mechanical performance of UHSS steel. The results show that when the heating temperature is 900°C or above, the original microstructure of B1500HS steel can be fully austenitized. Variation of austenitization temperature in the range of 900°C ∼ 960°C has no obvious effect on the mechanical properties of hot stamping parts cooled at the same mold temperature. The mold temperature has a significant effect on the mechanical properties; the structural components with distributed properties can be manufactured by controlling the mold temperature. The austenitization and mold temperatures have no obvious effect on the elongation of parts except the part with the subcritical quenching. The austenitization temperature of 900°C and mold temperature of 100°C are the better parameters of hot stamping for the parts of B1500HS steel required with higher hardness and strength.
Investigation of Structural, Morphological, and Dynamic Mechanical Properties of Unvulcanized PDMS/Silica Compound
Authors: Liu J. S. , Li F. P. , He X. 
Published: February 2017

Abstract
In this study, the interaction between the silica filler and polydimethylsiloxanes (PDMS) was investigated from the aspects of the bound rubber and morphological characterization. With special attention to the dynamic properties, the dynamic test was conducted by dynamic shear rheometer. The results show that the modified filler disperses uniformly within the PDMS matrix without aggregation and connects closely with the matrix compared to that of the unmodified fillers. Surface modification of the filler increases the bound-rubber content. The increase in silica loading leads to an increase in the silica–silica interaction and a decrease in filler–rubber interaction, which results in the aggregation of fillers and the increase of the bound-rubber content. It was apparent that storage modulus, loss modulus, and tanδ of unvulcanized PDMS/filler compounds filled with treated silica filler were lower than that of the untreated silica system. Moreover, the tanδ decreases with increasing silica loading.
An Agonist of the Protective Factor SIRT1 Improves Functional Recovery and Promotes Neuronal Survival by Attenuating Inflammation after Spinal Cord Injury
Authors: Chen Haihong , Ji Hao , Zhang Ming , Liu Zude , Lao Lifeng , Deng Chao , Chen Jianwei , Zhong Guibin 
Published: February 2017

Targeting posttraumatic inflammation is crucial for improving locomotor function. SIRT1 has been shown to play a critical role in disease processes such as hepatic inflammation, rheumatoid arthritis, and acute lung inflammation by regulating inflammation. However, the role of SIRT1 in spinal cord injury (SCI) is unknown. We hypothesized that SIRT1 plays an important role in improving locomotor function after SCI by regulating neuroinflammation. In this study, we investigate the effect of SIRT1 in SCI using pharmacological intervention (SRT1720) and the Mx1-Cre/loxP recombination system to knock out target genes. First, we found that SIRT1 expression at the injured lesion site of wild-type (WT) mice (C57BL/6) decreased 4 h after SCI and lasted for 3 d. Moreover, administration of SRT1720, an agonist of SIRT1, to WT mice significantly improved functional recovery for up to 28 d after injury by reducing the levels of proinflammatory cytokines, the number of M1 macrophages, the number of macrophages/microglia, and the accumulation of perivascular macrophages. In contrast, administration of SRT1720 to SIRT1 knock-out (KO) mice did not improve locomotor recovery or attenuate inflammation. Furthermore, SIRT1 KO mice exhibited worse locomotor recovery, increased levels of inflammatory cytokines, and more M1 macrophages and perivascular macrophages than those of WT mice after SCI. Together, these findings indicate that SRT1720, an SIRT1 agonist, can improve functional recovery by attenuating inflammation after SCI. Therefore, SIRT1 is not only a protective factor but also an anti-inflammatory molecule that exerts beneficial effects on locomotor function after SCI.SIGNIFICANCE STATEMENTPosttraumatic inflammation plays a central role in regulating the pathogenesis of spinal cord injury (SCI). Here, new data show that administration of SRT1720, an SIRT1 agonist, to wild-type (WT) mice significantly improved outcomes after SCI, most likely by reducing the levels of inflammatory cytokines, the number of macrophages/microglia, perivascular macrophages, and M1 macrophages. In contrast, SIRT1 KO mice exhibited worse locomotor recovery than that of WT mice due to aggravated inflammation. Taken together, the results of this study expand upon the previous understanding of the functions and mechanisms of SIRT1 in neuroinflammation following injury to the CNS, suggesting that SIRT1 plays a critical role in regulating neuroinflammation following CNS injury and may be a novel therapeutic target for post-SCI intervention.
Paraventricular Thalamus Balances Danger and Reward
Authors: Choi Eun A. , McNally Gavan P. 
Published: February 2017

Foraging animals balance the need to seek food and energy against the accompanying dangers of injury and predation. To do so, they rely on learning systems encoding reward and danger. Whereas much is known about these separate learning systems, little is known about how they interact to shape and guide behavior. Here we show a key role for the rat paraventricular nucleus of the thalamus (PVT), a nucleus of the dorsal midline thalamus, in this interaction. First, we show behavioral competition between reward and danger: the opportunity to seek food reward negatively modulates expression of species-typical defensive behavior. Then, using a chemogenetic approach expressing the inhibitory hM4Di designer receptor exclusively activated by a designer drug in PVT neurons, we show that the PVT is central to this behavioral competition. Chemogenetic PVT silencing biases behavior toward either defense or reward depending on the experimental conditions, but does not consistently favor expression of one over the other. This bias could not be attributed to changes in fear memory retrieval, learned safety, or memory interference. Rather, our results demonstrate that the PVT is essential for balancing conflicting behavioral tendencies toward danger and reward, enabling adaptive responding under this basic selection pressure.SIGNIFICANCE STATEMENTAmong the most basic survival problems faced by animals is balancing the need to seek food and energy against the accompanying dangers of injury and predation. Although much is known about the brain mechanisms that underpin learning about reward and danger, little is known about how these interact to solve basic survival problems. Here we show competition between defensive (to avoid predatory detection) and approach (to obtain food) behavior. We show that the paraventricular thalamus, a nucleus of the dorsal midline thalamus, is integral to this behavioral competition. The paraventricular thalamus balances the competing behavioral demands of danger and reward, enabling adaptive responding under this selection pressure.
RainbowEnhancers Regulate Restrictive Transcription in Teleost Green, Red, and Blue Cones
Authors: Fang Wei , Guo Chuanyu , Wei Xiangyun 
Published: February 2017

Photoreceptor-specific transcription of individual genes collectively constitutes the transcriptional profile that orchestrates the structural and functional characteristics of each photoreceptor type. It is challenging, however, to study the transcriptional specificity of individual photoreceptor genes because each gene's distinct spatiotemporal transcription patterns are determined by the unique interactions between a specific set of transcription factors and the gene's owncis-regulatory elements (CREs), which remain unknown for most of the genes. For example, it is unknown what CREs underlie the zebrafishmpp5bponli(ponli) andcrumbs2b(crb2b) apical polarity genes' restrictive transcription in the red, green, and blue (RGB) cones in the retina, but not in other retinal cell types. Here we show that the intronic enhancers of both theponliandcrb2bgenes are conserved among teleost species and that they share sequence motifs that are critical for RGB cone-specific transcription. Given their similarities in sequences and functions, we name theponliandcrb2benhancers collectivelyrainbowenhancers.Rainbowenhancers may represent acis-regulatory mechanism to turn on a group of genes that are commonly and restrictively expressed in RGB cones, which largely define the beginning of the color vision pathway.SIGNIFICANCE STATEMENTDim-light achromatic vision and bright-light color vision are initiated in rod and several types of cone photoreceptors, respectively; these photoreceptors are structurally distinct from each other. In zebrafish, although quite different from rods and UV cones, RGB cones (red, green, and blue cones) are structurally similar and unite into mirror-symmetric pentamers (G-R-B-R-G) by adhesion. This structural commonality and unity suggest that a set of genes is commonly expressed only in RGB cones but not in other cells. Here, we report that therainbowenhancers activate RGB cone-specific transcription of theponliandcrb2bgenes. This study provides a starting point to study how RGB cone-specific transcription defines RGB cones' distinct functions for color vision.