bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Strength and Conditioning on Maximal Isometric Strength, Motor Unit Behavior, and Concentric Isokinetic Peak Torque in Middle-School Boys'
Authors: MacLennan Rob J. , Mota Jacob A. , Thompson Brennan J. , Stock Matt S. 
Published: March 2021

Abstract
MacLennan, RJ, Mota, JA, Thompson, BJ, and Stock, MS. Effects of strength and conditioning on maximal isometric strength, motor unit behavior, and concentric isokinetic peak torque in middle-school boys. J Strength Cond Res 36(5): 1318–1326, 2022—It has long been theorized that improvements in muscle strength in young athletes are mediated by motor unit adaptations. The ability to decompose surface electromyographic signals obtained during isometric contractions now allow for such research questions to be answered. We examined changes in isometric and concentric isokinetic strength, as well as vastus lateralis motor unit behavior, after 16 weeks of strength training and conditioning in middle-school aged boys. Nine boys (mean ± SD age = 12 ± 1 years) participated in training. Five boys (age = 13 ± 1 years) served as control subjects. The training subjects performed 90 minutes of high-intensity, multi-joint exercise twice per week. Assessments of unilateral maximal voluntary isometric contraction (MVIC) force of the knee extensors, concentric peak torque at velocities of 60, 180, and 300°·s−1, and vastus lateralis motor unit data during 50 and 80% MVIC tests were performed. Strength training and conditioning did not improve MVIC force. Greater training-induced strength increases were observed at faster isokinetic velocities, with a large effect size at 300°·s−1 (d = 0.813). The slopes and y-intercepts of the mean firing rate vs. recruitment threshold relationship and the action potential amplitude vs. recruitment threshold relationship were unaffected by training. Sixteen weeks of middle-school strength and conditioning did not enhance maximal isometric strength or vastus lateralis motor unit control, but improvements were observed during rapid isokinetic muscle actions. Given the lack of training (multi-joint) vs. testing (single-joint) specificity, we propose that motor unit adaptations in youth are task specific.
Quantity of Resistance Exercise for Breast Cancer Patients: Does the Dose Match the Objective?
Authors: Rosenberg Jared , Hyde Parker N. , Yancy William S. , Ford Kenneth M. , Champ Colin E. 
Published: March 2021

ABSTRACT
Rosenberg, J, Hyde, PN, Yancy, WS, Ford, KM, and Champ, CE. Quantity of resistance exercise for breast cancer patients: does the dose match the objective? J Strength Cond Res 35(5): 1467–1476, 2021—There is currently a lack of consensus as to what defines exercise and resistance training in the cancer setting and whether current studies comply with exercise guidelines. This study aimed to quantify the available research studies using resistance training exercise interventions in the breast cancer setting for future clinical trial utilization. We systemically reviewed all available resistance exercise studies during and after breast cancer treatment in an attempt to quantify to the prescribed dose and whether regimens aligned with general exercise guidelines to improve functional mobility, body composition, and metabolic function. They were then compared with recommendations set forth by the national committees that create evidence-based exercise guidelines. Fifty studies met the initial criteria, with 35 meeting analysis criteria for evaluation. Fifteen studies evaluated an exercise regimen during cancer treatment, and 20 evaluated a regimen after treatment. The average adherence rates were 84% for all studies. Only 23 studies listed specific exercises used within the protocol. Most exercise regimens relied on open chain movements and machine exercises. Around half of studies met criteria to achieve hypertrophy, and 66% met American College of Sports Medicine exercise guidelines for cancer patients. A minority of breast cancer studies implementing a resistance training exercise regimen prescribed a regimen or specific dose that follows general exercise guidelines. This study highlights a potential deficiency in exercise programs designed for patients with breast cancer, and these findings should be considered in future study design.
Relationships Between Sprinting, Broad Jump, and Vertical Jump Kinetics Are Limited in Elite, Collegiate Football Athletes
Authors: Boone Joseph B. , VanDusseldorp Trisha A. , Feito Yuri , Mangine Gerald T. 
Published: March 2021

Abstract
Boone, JB, VanDusseldorp, TA, Feito, Y, and Mangine, GT. Relationships between sprinting, broad jump, and vertical jump kinetics are limited in elite, collegiate football athletes. J Strength Cond Res 35(5): 1306–1316, 2021—To evaluate the relationships and agreement in kinetics measured during a 10-yd sprint, a standing broad jump (SBJ), and a vertical jump (VJ), 73 collegiate football players (22.3 ± 0.8 years, 188 ± 7 cm, 113 ± 23 kg) volunteered for this cross-sectional study over a 3-year period. At the beginning of each athlete's off-season training phase and after a standard warm-up, each athlete completed 2–3 maximal trials of each test while tethered to a robotic, cable-resistance device (10-yd sprint and SBJ) or a linear position transducer (VJ alone). Force (N), velocity (m·s−1), and power (W) were measured during the first 2 steps, acceleration phase (units·step−1), and entire 10-yd sprint, and the entire SBJ and VJ. Spearman and partial correlations (controlling for stature) revealed small-to-moderate relationships (r = −0.30 to −0.34) between the second sprinting step and VJ force. Small negative relationships were also noted between sprinting and VJ force and power, but not when controlling for height. Agreement was determined by examining relationships between the differences in and averaged kinetics measured on each test. Trivial-to-small relationships (r < 0.29) were observed between sprinting (first step and 10-yd) and VJ velocity, and between VJ and SBJ velocity, although coefficient of variation (CV) ranged between 64 and 104%. All other relationships ranged from moderate-to-practically perfect with CVs exceeding 500%. Although some relationships exist between sprinting and jumping kinetics, their agreement is variable. These data suggest that coaches and athletes should not use one of these assessments in place of, or to predict performance in, the other assessments.
Hip and Knee Extensor Activation During the Hip Thrust and Rear-Foot–Elevated Split Squat in Trained Females
Authors: McCurdy Kevin , Walker John , Kelly Camila , Polinski Michael 
Published: March 2021

Abstract
McCurdy, K, Walker, J, Kelly, C, and Polinski, M. Hip and knee extensor activation during the hip thrust and rear-foot–elevated split squat in trained females. J Strength Cond Res 35(5): 1201–1207, 2021—The aim of the study was to compare hip and knee extensor muscle activation between the hip thrust (HT) and rear-foot–elevated split squat (RFESS) within different depths and the entire range of motion. Twenty, young adult female subjects (age, 20.9 ± 1.3 years; height, 164.6 ± 7.5 cm; mass 63.2 ± 8.8 kg) with an intermediate level of resistance training experience completed the study. Three repetitions were completed at 80% of the 1-repetition maximum. Gluteus maximus, vastus lateralis, and the medial (semitendinosus and semimembranosus) and lateral (biceps femoris) hamstrings electromyographic data were compared at the top, middle, and bottom one-third of the hip range of motion and for the entire repetition. A repeated-measures analysis of variance was used to test significance set at p ≤ 0.05. All 4 muscles revealed higher (p < 0.001) activation at the top position of the HT compared with the middle and bottom, whereas higher scores (p < 0.001) were found in the bottom position during the RFESS. The HT revealed greater activity (p < 0.001) than the RFESS in all muscles at the top, whereas the RFESS showed higher scores (p < 0.001) than the HT in all muscles in the bottom position. For the entire repetition, the RFESS produce significantly greater vastus lateralis activation (59.4 vs 43.6%). The data indicate that the greatest effect for the HT is demonstrated in the top position and at the bottom for the RFESS. Thus, we recommend to implement both exercises in a training program to maximize gluteus maximus and hamstring activation across the full range of motion. For the greatest vastus lateralis activation, the RFESS is recommended.
Unraveling the Temporal Dynamics of Reward Signals in Music-Induced Pleasure with TMS
Authors: Mas-Herrero Ernest , Dagher Alain , Farrés-Franch Marcel , Zatorre Robert J. 
Published: March 2021

Music's ability to induce feelings of pleasure has been the subject of intense neuroscientific research lately. Prior neuroimaging studies have shown that music-induced pleasure engages cortico-striatal circuits related to the anticipation and receipt of biologically relevant rewards/incentives, but these reports are necessarily correlational. Here, we studied both the causal role of this circuitry and its temporal dynamics by applying transcranial magnetic stimulation (TMS) over the left dorsolateral PFC combined with fMRI in 17 male and female participants. Behaviorally, we found that, in accord with previous findings, excitation of fronto-striatal pathways enhanced subjective reports of music-induced pleasure and motivation, whereas inhibition of the same circuitry led to the reduction of both. fMRI activity patterns indicated that these behavioral changes were driven by bidirectional TMS-induced alteration of fronto-striatal function. Specifically, changes in activity in the NAcc predicted modulation of both hedonic and motivational responses, with a dissociation between pre-experiential versus experiential components of musical reward. In addition, TMS-induced changes in the fMRI functional connectivity between the NAcc and frontal and auditory cortices predicted the degree of modulation of hedonic responses. These results indicate that the engagement of cortico-striatal pathways and the NAcc, in particular, is indispensable to experience rewarding feelings from music.SIGNIFICANCE STATEMENTNeuroimaging studies have shown that music-induced pleasure engages cortico-striatal circuits involved in the processing of biologically relevant rewards. Yet, these reports are necessarily correlational. Here, we studied both the causal role of this circuitry and its temporal dynamics by combining brain stimulation over the frontal cortex with functional imaging. Behaviorally, we found that excitation and inhibition of fronto-striatal pathways enhanced and disrupted, respectively, subjective reports of music-induced pleasure and motivation. These changes were associated with changes in NAcc activity and NAcc coupling with frontal and auditory cortices, dissociating between pre-experimental versus experiential components of musical reward. These results indicate that the engagement of cortico-striatal pathways, and the NAcc in particular, is indispensable to experience rewarding feeling from music.
Participation of the C-terminal propeptide procollagen type I in the formation of cardiofibrosis in patients with myocardial infarction with preserved left ventricular ejection fraction
Authors: Osokina A. V. , Karetnikova V. N. , Polikutina O. M. , Ivanova A. V. , Pecherina T. B. , Gruzdeva O. V. , Dyleva Yu. A. , Kokov A. N. , Brel N. K. , Barbarash O. L. 
Published: March 2021

Aim. To study the dynamics of procollagen type I carboxy-terminal propeptide (PICP) with an assessment of potential associations with cardiac fibrosis (CF) and diastolic dysfunction (DD) of the left ventricle (LV) during the hospitalization and one year after ST segment elevation myocardial infarction (STEMI).Material and methods. The study included 120 patients with STEMI. There were following inclusion criteria: diagnosis of STEMI (2015 European Society of Cardiology guidelines); Killip £III acute heart failure (AHF); signed informed consent; patient age >18 years old. There were following exclusion criteria: STEMI due to percutaneous coronary intervention or coronary artery bypass grafting; Killip IV AHF; patient age >80 years; clinically significant comorbidities; death of the patient during the first day of hospitalization. On the 1st, 12th day of the disease and after a year all patients underwent echocardiography and the PICP concentration was determined. One year after myocardial infarction, contrast-enhanced cardiac magnetic resonance imaging was performed to assess CF. In the analyzed group of patients, on day 1 of STEMI, mean values of LV ejection fraction (EF) in the range of 40-49% were observed in 3 (2,5%) patients, LVEF <40% — in 31 (26%), LVEF ≥50% — in 86 (71,7%). The final analysis was performed on a sample of patients with preserved LVEF (n=86) (71,7%).Results. On the first day of myocardial infarction, signs of DD were noted in 25 (29,1%) patients, while after 1 year, their number increased by 9 (10%) and amounted to 34 (39,5%) patients. In 15 (17,6%) people, worsening of myocardial systolic dysfunction was noted. Patients with a CF ³16% had the highest PICP expression on the first day of the disease. CF ≥16% one year after STEMI with preserved EF is associated with PICP concentration on day 1 of the disease. In addition, multidirectional correlations were revealed between the CF ≥16% and parameters of LV diastolic function (e’, mean pulmonary artery pressure, E/e’).Conclusion. Determination of the PICP concentration on the 1st day of myocardial infarction will allow early identification of patients at risk of CF one year after STEMI with preserved EF.
Heart failure with preserved ejection fraction: the role of diastolic stress test in diagnostic algorithms
Authors: Pavlyukova E. N. , Kuzhel D. A. 
Published: March 2021

Heart failure (HF) with preserved ejection fraction (HFpEF) is currently the most common type of this condition, especially among elderly patients. Despite the preserved left ventricular (LV) and a moderate increase in natriuretic peptide, patients with HFpEF have the same out-of-hospital mortality as those with HF with reduced ejection fraction (HFrEF). Diagnosis of HFpEF is difficult due to nonspecific symptoms, expensive blood tests, and questionable rest echocardiographic data on diastolic function. In addition, the reason for poor diagnosis of HfpEF in clinical practice may be old age and comorbidities, which can also cause nonspecific symptoms of moderate chronic shortness of breath, weakness, and palpitations. The consequence is the detection of HFpEF only in every fourth patient with an acute or chronic heart failure. The use of simplified clinical diagnostic protocols along with a non-invasive ultrasound stress test can help overcome the existing problems in the diagnosis of HFpEF.
Relationship of obesity, low-density lipoprotein cholesterol and myocardial perfusion in patients with risk factors and without atherosclerotic cardiovascular diseases
Authors: Sergienko V. B. , Ansheles A. A. , Sergienko I. V. , Boytsov S. A. 
Published: March 2021

Aim. In the retrospective study, to identify the relationship between body mass index (BMI), low-density lipoprotein cholesterol (LDL-C) levels and myocardial perfusion in patients without established atherosclerotic cardiovascular diseases.Material and methods. The study included 534 patients with cardiovascular risk factors but without established coronary artery disease, diabetes, myocardial infarction or coronary revascularization. In 76 of them, stress/rest myocardial perfusion single-photon emission computed tomography (SPECT) was performed.Results. The relationship between BMI and LDL-C levels is described by a quadratic (r2=0,21, p<0,001) function or a linear spline kinked in BMI of 27 kg/m2 (r=0,51, -0,46 — before and after this value, respectively; p<0,001). According to SPECT, focal stable and transient left ventricular myocardial perfusion abnormalities were not detected. However, there was a direct linear correlation between the heterogeneity of rest myocardial perfusion (ohet) and BMI (r=0,43, p<0,001), ohet and waist circumference (r=0,40, p<0,001), as well as between ohet and LDL-C (r=0,44, p<0,001).Conclusion. The relationship between BMI and LDL-C levels can be explained by endocrine dysfunction of adipose tissue, which disturbs the synthesis and metabolism of atherogenic lipoproteins. Obesity and increased LDL-C levels affect myocardial perfusion both by aggravating coronary atherogenesis and by microcirculatory disorders. Rest myocardial perfusion SPECT can be a method of screening for myocardial disorders caused by both diffuse atherosclerosis and metabolic syndrome.
Experimental and theoretical evidence for the load sequence effect in the compressive fatigue behavior of concrete
Authors: Baktheer Abedulgader , Chudoba Rostislav 
Published: March 2021

AbstractA realistic prediction of the concrete fatigue life exposed to high-cycle loading scenarios with variable amplitudes is of utmost importance for a reliable and economically efficient design of civil engineering infrastructure for transport and energy supply. Current design codes estimate the fatigue life under variable amplitudes using the Palmgren–Miner rule, which assumes a linear scaling between lifetimes measured for uniform cyclic loading scenarios. Several experimental series conducted in the past, however, indicate that this assumption is not valid and that it may lead to unsafe design. In this paper, an experimental and theoretical investigations of the fatigue loading sequence effect in normal- and high-strength concrete behavior are presented, which confirm this observation. In particular, a test campaign with 135 cylinder specimens, including three concrete grades and six different loading scenarios has been conducted. Several response characteristics of the fatigue behavior including Wöhler curves, fatigue creep curves and evolving shapes of hysteretic loops have been evaluated. To substantiate the experimental results, a theoretical explanation of the observed sequence effect is formulated based on the assumption, that energy is dissipated uniformly within the volume of a test specimen during subcritical, compressive cyclic loading. Then, superposition of energy dissipation profiles along the lifetime measured for constant amplitudes becomes possible and a theoretical justification of the experimentally observed sequence effect can be provided. Moreover, a reverse sequence effect reported in the literature for bending fatigue of concrete can then be explained by an unevenly distributed energy dissipation over a cracked specimen. Supported by the theoretical consideration, the processed experimental data is used to validate existing fatigue life assessment rules by testing their ability to reflect the load sequence effect.
The effect of titanium-carbon mixture mechanical activation on SHS pressing parameters and consolidated titanium carbide microstructure
Authors: Bogatov Yu. V. , Shcherbakov V. A. , Kovalev I. D. 
Published: March 2021

The paper studies the effect of mechanical activation (MA) modes when stirring a stoichiometric mixture of titanium and soot powders in a ball mill on the properties of mixtures, combustion parameters, relative density, and the microstructure of consolidated titanium carbide samples obtained by SHS. MA conditions for Ti + C reaction mixtures in a ball mill were determined. An increase in the mass of grinding bodies activates the MA mechanism. It was shown that the greatest effect from MA was obtained with a two-stage preparation of mixtures: firstly, the titanium powder was activated separately, then the components were mixed together, and this process included not only their mixing, but also soot powder activation. It was found that combustion behavior is affected by the activation of not only titanium, but also soot. After MA of both components, an anomalous increase in the burning rate (more than 100 cm/s) was found on pressed samples. At the bulk density, there was no effect of MA on the mixture combustion process, since in this case the burning rate of all mixtures was in the range of 1.5–2.5 cm/s. It was revealed that MA of reagents for pressed samples leads to an increase in the combustion temperature, an increase in the relative density of the consolidated refractory product to 93–95 %, and a decrease in the average size of TiC grains. A decrease in the residual porosity of consolidated TiC is due to an increase in the hot pressing temperature and plasticity of the product synthesized during the reaction mixture combustion after MA. The main reason is an increase in the exothermic interaction rate. It was shown that MA when mixing reagents makes it possible to control combustion parameters, the microstructure of consolidated products and opens up new opportunities for obtaining refractory materials featuring a unique structure and properties by SHS pressing.
ISOLATION AND MOLECULAR IDENTIFICATION OF BRUCELLA MELITENSIS IN ABORTED FETUSES OF SHEEP AND GOATS IN SULAIMANI PROVINCE, IRAQ
Authors: Nassrullah Othman , Mohammad Mohammad , Rachid Shwan 
Published: March 2021

Background
Brucellosis is a zoonotic disease that is endemic in Sulaimani Province, Iraq. The most accurate, credible, and susceptible method for detecting Brucella DNA is Polymerase Chain Reaction (PCR). A significant increase in abortion rates among the sheep and goats population in Sulaimani Province, Iraq was recorded by Veterinary centers.
Objectives
To detect the most common causes of abortion in sheep and goats.
Materials and Methods
A total of 73 aborted fetuses were collected during the delivery season in 2018, 53 sheep and 20 goats. Four sets of primers gene were achieved: firstly, for identification of the positive infection with all possible Brucella genus, the universal ‘catch-all’ primers (OMP2). Others, the specific primers (IS711) for identification Brucella species in all positive and negative samples.
Results
PCR showed that Brucella was the important cause of abortion in sheep and goats (P<0.05). Brucella melitensis was the only species detected, with prevalence rates of (32%) and (60%) in sheep and goats, respectively. Some independent variable risk factors were estimated that were statistically significant, including sex and age of the fetus, age of dam, infected organs of the fetus, history of abortion, and parity.
Conclusion
There was a significant relationship between abortion and the history of abortion in sheep and goats. Brucella melitensis is a serious reason for abortion in sheep and goats, and a great hazard to public health in Sulaimani Province.