bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cyclic loading on mechanical properties and microstructure of die cast magnesium alloy AZ91D
Authors: Li Jiquan , Chen Long , Wang Fenghua , Jiang Shaofei , Gan Huiqi , Zhou Jun , Hao Weina
Published: February 2023

Magnesium alloy materials are often affected by cyclic stress, resulting in fatigue fracture due to changes in mechanical properties. In this study, external cyclic loads were introduced to simulate the loading of AZ91D (Mg-9Al-0.5Zn) parts. Tensile tests under static and external circulation loads were performed on the same specimens, and the effect of loading conditions on the mechanical properties of the specimens (tensile strength, yield strength and elongation) were studied. The internal microstructure of the test specimens was analyzed, and the influence of cyclic loading on the microstructure change of the specimens was discussed. Compared with static load, under the condition of cyclic loading, the tensile strength and yield strength of the specimens are increased by more than 15%, and the elongation rate is increased by 3 times. In addition, the microstructure images showed that many twins and the second phase β-Mg17Al12 were generated inside the AZ91D microstructure under cyclic loading. The former results in specimens crack initiation and it is the root cause of fatigue fracture. And the latter accounts for the strengthening of the mechanical properties of specimens.
Effect of high temperatures on dry sliding friction and wear behaviour of CuCrZr copper alloy
Authors: Mısırlı Cenk , Ceviz Mehmet , Çetintav Işık , Kılıç Halil
Published: February 2023

Dry friction and wear behavior at high temperatures was investigated against an Al2O3 ball in order to characterize the wear rate, coefficient of friction (COF), hardness and thermal friction behavior at different temperatures in the wear-treated zones of the CuCrZr copper alloy. Experiments were fulfilled using a pin-on-disk wear device with the aid of a temperature modulated wear device at room temperature, 100, 200 and 300 °C. The loads applied during wear are given as 3N, 5N and 7N, respectively. In order to examine the morphological structure of the worn surfaces, appropriate samples were prepared and SEM (scanning electron microscopy) device was used. Similarly, EDS (energy dispersive x-ray spectrometry) was applied to worn surfaces to examine the abrasive-material interaction. Against the hardness of the material at 25 °C, the hardness value in measurements at 300 °C showed a small increase. The COF value increased at 100 °C and then decreased, while the wear rate increased significantly as the temperature increased. The temperature increase starting from RT up to 300 °C weakened the internal structure of the CuCrZr alloy and caused an increase in the wear rate. XRD test was used to show the phases that may occur in CuCrZr alloy due to temperature and heat treatment.
Emerging in ovo technologies in poultry production and the re-discovered chicken model in preclinical research
Authors: Niloofar Akhavan , Marek Bednarczyk , Krzysztof Krajewski , Katarzyna Stadnicka
Published: February 2023

Prenatal programming is a concept based on assumptions that the events occurring in critical points of embryonic development may pose epigenetic changes resulting from chemical rearrangements on the DNA structure. Epigenetic changes may pose life lasting phenotypic effects in the animal, or can be heritable, like gene silencing associated with methylation in gene promoters regions. The technical advancements in biotechnology, bioinformatics, molecular techniques and robotization have brought to new technological applications in poultry production. Intentional stimulation of embryonic development and determination of the future health of the hatched organism is possible by in ovo
application of natural antioxidants and prebiotics, gut stabilizers like probiotics and other immunological enhancements, including vaccines. In parallel, the fine-tuned and generally accessible techniques of chicken embryo incubation along with the novel tissue engineering tools have led to focus the attention of scientists on chicken embryo as the alternative animal model for some pre-clinical approaches, in the context of reducing and replacing the experiments on animals. In this chapter, some key highlights are provided on current achievements in poultry embryonic applications, with the attention put to the emerging in ovo
technologies (in ovo feeding, immunological stimulation and in ovo oncological tools), that address the societal challenges in food production and health management.
Removal and isolation of radioactive cobalt using DNA aptamers
Authors: Lee Sun Young , Jang Dae Hyuk , Kim Hyuncheol , Yun Miyong
Published: February 2023

Electricity generation using nuclear power has various advantages, such as carbon reduction, but the treatment of nuclear waste is emerging as a big issue in many countries. The development of technology that can selectively remove radionuclides from liquid radioactive waste is one of the ways to reduce nuclear waste. Here, we assessed a new way of removing radioactive cobalt from a liquid using an aptamer. Aptamers specifically binding cobalt ions were selected through systematic evolution of ligands by exponential enrichment (SELEX). Their binding strength and stability of their complexes with cobalt were analyzed through surface plasmon resonance assay and 2D program Mfold, respectively. The optimal aptamer/bead conjugate conditions for binding cobalt were established using an FA-C1 aptamer with the strongest binding to cobalt. Under these conditions, more than 80% of radioactive cobalt was removed, and more than 99.95% of removed cobalt was recovered. These results proved that radioactive cobalt removal using this aptamer can effectively reduce liquid radioactive waste. This means that the aptamer/bead complex can be utilized to remove various radioactive metal ions.
Analysis of the phase-dependent fluorescence decay time of treated wood using FD-FLIM
Authors: Leiter Nina , Wohlschläger Maximilian , Versen Martin
Published: February 2023

For sustainable handling of wood and high material utilization, post-consumer wood has to be sorted by post-consumer wood categories in Germany. The non-destructive FD-FLIM method could improve the wood recycling process by automatic classification of waste wood into post-consumer wood classes. Thus, the phase-dependent fluorescence decay time of treated wood is analysed in this study to obtain the impact of the treatment on the fluorescence decay time. It is shown that treated and untreated wood can be differentiated using the fluorescence decay time, although the state-of-the-art theoretical fluorescence decay time differs from the experimentally determined fluorescence decay time.
The Structure and Cultural Implications of the Inscriptions of Shandong Academy in the Qing Dynasty
Authors:   Institute of Korean Cultural Studies Yeungnam University, Seo An Peung , Noh Heung Min
Published: February 2023

This article examines the constitutional structure of more than 100 inscriptions on Shandong Academy in Qing Dynasty, and reveals that there is a similar writing pattern among them: the author first cites the teachings of the former kings, and regards the establishment of the academy as a grand event to inherit the legacy of the three generations, and its significance is highlighted ; Then the author puts his brushwork on the tradition of a place, the mountains and rivers are so beautiful, the predecessors are so outstanding, how can the future generations be left alone, the rise of the academy is an act of reviving the humanities; Hard work, it is imperative to create an academy, but its creation is not easy, so future generations should not fall into their careers, and follow things to increase ; Finally, the author expresses his desire for the development of humanities. To explore the formation mechanism of this similar writing mode, we must return to the outstanding stylistic features of the stele, that is, the inscription, materiality and display presented on the stele. It seems to be a kind of “solid”·Writing writings that are expected to be handed down to future generations, they are produced in a rich context : In Shandong, which has rich cultural accumulation, it is an academy for cultivating talents; it was formed through the hands of local officials or local scribes; it is preserved in local chronicles such as art and literature records, school records, political and educational records, construction records, document records and historical site records. Each of them The background or related measures endow the inscription with special cultural and literary meaning , showing the cultural heritage and “local scenery” in the clues of the past, present and future.

본고에서는 백여 편에 달하는 청대 산동서원 비문의 구성 체계를 검토해봄으로써 그 가운데 존재하는 유사한 문장 양식을 도출해볼 것이다. 우선, 비문의 작자는 선왕(先王)의 가르침을 열거하면서 서원의 창건이 삼대(三代)의 유산을 전승하는 성대한 행사임을 강조한다. 그리고 작자는 필촉(筆觸)을 한 점에 두는 전통에 입각하여, ‘산천(山川)이 이처럼 영명하고, 고대 현인들이 이처럼 훌륭하니, 후손들이 어찌 이 장소를 방치할 수 있겠는가, 서원의 부흥이 바로 인문(人文)을 중흥하는 일이다’라고 말하고 있다. 또 그는 당면한 현실에대해 묘사하면서, 사인(士人)들이 과거를 준비하는 데 노고가 많으니 반드시서원을 창건, 수복하여 세(勢)를 회복하여야만 하는데, 이것은 결코 쉬운 작업이 아니므로 후손들이 마땅히 그 업무를 놓지 않고 더욱 발전시켜야 한다고말한다. 마지막으로, 작자는 인문(人文) 부흥이라는 소망을 드러내고 있다. 이러한 상호 유사한 문장 양식의 형성 근거를 탐구하려면, 반드시 비문에 드러나는 문체 특징을 검토하여야만 할 것이다. 이것이 바로 비석에 드러난 각명(刻銘)의 특징이자 고유한 물질성, 표현성이라 할 수 있다. 서원의 비문은 일종의 ‘견고함’을 특징으로 가지며, 후대에 전승되길 바라는 의도가 담긴 문자작품인 것으로 보인다. 비문은 지방 관원 또는 현지 선비들에 의해 제작되었으며, 보통 지방지의 예문지(藝文志), 학교지(學校志), 정교지(政敎志), 영건지(營建志), 문헌지(文獻志), 고적지(古跡志) 속에 많이 보존되어 있다. 각 비문의배경 혹은 이에 관련된 조치들은 모두 비문에 대하여 특별한 문화적, 문학적의미를 부여한다. 그것은 과거, 현재, 미래의 연속선 상에서 문화적 함의와“현지의 분위기”를 드러낸다.
A Study on the World of Works by Mumyeongja Yun Ki during the Declaration of silence
Authors:   Institute of Korean Cultural Studies Yeungnam University, Im Wanhyuk
Published: February 2023

The Mumyeong ja Yun Ki made a silent declaration at the ag e of 69 in 1819. 'I won't speak' doesn't mean passive. It is a declaration that 'I will talk about the world through writing' because speaking causes problems. The purpose of this paper is to confirm the will and substance of the work at the time of the declaration.
Yoongi had a problematic consciousness about the extreme gap between the rich and the poor in the 18th and 19th centuries, and he suffered from extreme poverty, In particular, at the ag e of 69, he became more critical of the social phenomenon amid a sense of crisis that he was the one who said he would starve to death even after wearing a red patch. After experiencing conflict due to utterance that appears from the age of 50, he finally declared that he would reveal his inner voice through writing at the age of 69.
At the age of 69, Yoongi re-established his situation, and his critical attitude toward the world became clearer.
He practiced speech about the world through satire on five lazy objects such as lazy scholars, descriptions of 14 old objects such as old scholars, and critical works on eight topics such as <詠不修業而科時奔走 者> and criticized gwageoje(制擧制). In particular, in this year, the critical perception of “money” was revealed in earnest, criticizing the state of the world being exhausted due to “money” symbolized by <錢說>, <錢 五十韻>, <詠守錢虜>, <打破歌>.
The psychological basis of the 69-year-old's declaration of silence, 'Critical attitude and spirit', was later practiced. It is meaningful in literary history and mental history that he kept his spirit and attitude as Poor and Humble Scholars and did not stop his critical voice of the world until the end of the life.
Constitution of Sanitary Space in Traditional Market: A Case of Seomun Market in Daegu
Authors:   Institute of Korean Cultural Studies Yeungnam University, Chung Jaeyoung
Published: February 2023

The purpose of this study is to understand how the concept of ‘sanitation’, as spoken of by those who lead change in space, operates in space and creates and constructs new space through the case of the Seomun Market in Daeg u.
For this, the formation and transition processes of the Yang-gok Alley in Seomun Market were traced and aspects of how the placeness of Yang-gok Alley was restructured were observed. At this, the following aspects could be understood.
First, g rain merchants of Seomun Market have continued to conduct business in Seomun Market since it was first formed until now and they have formed their space but the grain merchants of Seomun Market have experienced fluctuations following changes in the national and local economy and currently, grain merchants and the Yang-gok Alley have become established as marginalized presences in the Seomun Market, in which textile businesses have become the center.
Second, while butchery merchants and street vendors, who formed Yang-gok Alley alongside the grain merchants, have kept their place and have maintained business despite conflicts with surrounding merchants, they have been disbanded, unable to withstand pressure from the Jung-gu Office, the Merchants’ Association, and surrounding merchants as the 2nd District shopping area was burnt down by a fire and reconstructed and the space of the Yang-gok Alley is also being newly formed.
Third, as the 2nd District was being reconstructed, the butchery shops were disbanded throug h the cultural and political log ic of sanitary spaces and as the placeness of the Dak-jeon Alley became lost, the placeness of the Yang-gok Alley also changed. Also, as the placeness of stores with different characteristics such as coffee shops was attached, the placeness of Yang-gok Alley in the current Seomun Market is being reconstituted.
The Impact of Sarcopenia Risk on Postoperative Walking Independence in Older Adults Undergoing Total Joint Arthroplasty
Authors: Nanri Yuta , Shibuya Manaka , Nozaki Kohei , Takano Shotaro , Iwase Dai , Aikawa Jun , Fukushima Kensuke , Uchiyama Katsufumi , Takahira Naonobu , Fukuda Michinari
Published: February 2023

Background and Purpose:

Sarcopenia is known to be associated with poor outcomes after arthroplasty; however, no study has reported the relationship between sarcopenia and postoperative walking independence. This study aimed to determine the impact of sarcopenia risk screening using the SARC-CalF questionnaire and calf circumference on the time to walk independently after total hip or knee arthroplasty in older patients.

Methods:

We included 599 nonobese patients aged 65 years and older who underwent unilateral and primary total hip or knee arthroplasty. Preoperative sarcopenia risk was assessed using the SARC-CalF or calf circumference. The outcome of this study was the time to independent walking after surgery; it was calculated as the number of days from the date of surgery to the date when the patient was able to walk independently. The association between preoperative sarcopenia risk and time to independent walking after surgery was analyzed using Kaplan-Meier curves and Cox proportional hazards models.

Results:

Among the 599 patients undergoing total joint arthroplasty, 175 (29.2%) were determined to be at risk of sarcopenia using SARC-CalF and 193 (32.2%) using calf circumference. The Kaplan-Meier curve showed that sarcopenia risk assessed by SARC-CalF or calf circumference was associated with a prolonged time to independent walking in patients undergoing hip arthroplasty (log-rank test, P < .001 and P < .001, respectively). In patients undergoing hip arthroplasty, the Cox proportional hazards model showed that SARC-CalF score of 11 points and greater or a calf circumference less than the cutoff was a risk factor for delayed time to independent walking (hazard ratios: 0.55 and 0.57, P < .001 and P = .001, respectively). There was no association between preoperative sarcopenia risk and postoperative time to independent walking in patients who underwent knee arthroplasty.

Conclusions:

Sarcopenia screening tools, such as SARC-CalF or calf circumference, should be useful for planning postoperative rehabilitation in older adults scheduled for hip arthroplasty. However, the accuracy of SARC-CalF or calf circumference measurement in patients scheduled for knee arthroplasty may be low.
Individual and Group Responses of Cardiorespiratory Fitness to Running and Cycling Sprint Interval Training
Authors: Digby Lauren , McCarthy Seth F. , Bornath Derek P.B. , Copeland Jennifer L. , Hazell Tom J.
Published: February 2023

Digby, L, McCarthy, SF, Bornath, DPB, Copeland, JL, and Hazell, TJ. Individual and group responses of cardiorespiratory fitness to running and cycling sprint interval training. J Strength Cond Res XX(X): 000–000, 2022—Sprint interval training (SIT) has gained popularity as an effective way to improve peak oxygen consumption (V̇O2peak) and subsequently health in a time-efficient manner. In addition, SIT has demonstrated improvements of ∼5–12% in V̇O2peak for both running and cycling protocols, although comparisons of differing modalities have yet to be examined. Therefore, this study sought to determine group and individual responses to running and cycling SIT while examining any crossover effects of running and cycling SIT when V̇O2peak is tested in different modes of exercise where 18 subjects completed either 3 weeks of cycling SIT (6 male, 3 female) or running SIT (5 male, 4 female) consisting of 4–6 repeated 30-second all-out bouts interspersed with 240 seconds of recovery. Cycling and running V̇O2peak tests were completed pretraining and post-training for the investigation of mode-specific cardiorespiratory fitness improvements. There were main effects of time for cycling V̇O2peak (P = 0.022,

= 0.499) and running V̇O2peak (P = 0.080,

= 0.334) that seem greater when testing in the same mode as training (∼+5.5%). A similar proportion of responders were identified in both training modes (∼67%) suggesting running and cycling SIT are both effective for improving cardiorespiratory fitness. These results suggest that the specificity of testing and training are important for SIT and that both running and cycling SIT are similarly effective at improving V̇O2peak.
Sprint Interval Training Attenuates Neuromuscular Function and Vagal Reactivity Compared With High-Intensity Functional Training in Real-World Circumstances
Authors: Benítez-Flores Stefano , Castro Flávio A. de S. , Lusa Cadore Eduardo , Astorino Todd A.
Published: February 2023

Benítez-Flores, S, de S. Castro, FA, Lusa Cadore, E, and Astorino, TA. Sprint interval training attenuates neuromuscular function and vagal reactivity compared with high-intensity functional training in real-world circumstances. J Strength Cond Res XX(X): 000–000, 2022—The aim of this study was to compare the acute cardiovascular and neuromuscular effects of 3 time-matched sessions of high-intensity training. Eighteen moderately active adults (9 women and 9 men [age: 23 ± 2.9 years; maximum oxygen consumption (V̇o
2max): 47.6 ± 4.1 ml·kg−1·min−1]) performed three low-volume (∼9 minutes) sessions in a randomized order: sprint interval training (SIT), burpee interval training (BIT) (10 × 5 seconds efforts × 35 seconds recovery), and vigorous intensity continuous training (VICT) (6 minutes 5 seconds of running at ∼85% of peak heart rate [HRpeak]). Indices related to heart rate (HR), neuromuscular performance (counter movement jump height [CMJheight] and squat and bench press power), and autonomic balance (heart rate recovery and heart rate variability [HRR and HRV] )were monitored during exercise. Sprint interval training and VICT elicited a higher HRmean (171.3 ± 8.4 and 166.5 ± 7.5 vs. 150.5 ± 13.6 b·min−1, p < 0.001) and time of ≥90%HRpeak (133.3 ± 117.4 and 110 ± 128.9 vs. 10 ± 42.4 seconds, p < 0.01) than BIT. Sprint interval training exhibited a slower HRR and lower HRV than BIT and VICT (p < 0.05) postsession. Moreover, only SIT resulted in a significant decline (p < 0.01) in CMJheight (34.7 ± 7.2 to 33.5 ± 7.2 cm), relative squat mean power (25.5 ± 4.5 to 23.8 ± 4.9 W·kg−1), and relative bench press peak power (6.9 ± 2.4 to 6.2 ± 2.5 W·kg−1). Results revealed that SIT diminishes the sympathovagal reactivation and neuromuscular performance compared with work-matched BIT and VICT.
Longitudinal Effects of Traditional and Rest Redistribution Set Configurations on Explosive-Strength and Strength-Endurance Manifestations
Authors: Janicijevic Danica , González-Hernández Jorge M. , Jiménez-Reyes Pedro , Márquez Gonzalo , García-Ramos Amador
Published: February 2023

Janicijevic, D, González-Hernández, JM, Jiménez-Reyes, P, Márquez, G, and García-Ramos, A. Longitudinal effects of traditional and rest redistribution set configurations on explosive-strength and strength-endurance manifestations. J Strength Cond Res 37(5): 980–986, 2023—This study aimed to compare the long-term effects of resistance training programs based on traditional and rest redistribution set configurations on explosive-strength and strength-endurance performance of lower-body and upper-body muscles. Thirty physically active men were randomly assigned to a traditional group (TRG: 6 sets of 5 repetitions with 3 minutes of interset rest) or a rest redistribution group (RRG: 30 sets of 1 repetition with 31 seconds of interrepetition rest). The training program lasted 6 weeks (2 sessions·wk−1), and in each training session, the squat and bench press exercises were performed with maximal concentric effort against approximately the 75% of the 1 repetition maximum. Before and after training, explosive-strength performance (peak velocity reached at submaximal loads during the countermovement jump and bench press throw) and strength-endurance performance (mean set velocity of 10 repetitions using both traditional and cluster sets in the squat and bench press) were assessed. Significant improvements in all dependent variables were observed after training for both the TRG (p ≤ 0.004; effect size [ES] = 0.63–3.06) and RRG (p ≤ 0.001; ES = 0.58–3.23). The magnitude of the changes was comparable for both groups with the only exception of the larger improvements observed in the RRG for the bench press mean set velocity using both traditional (ES = 0.77) and cluster (ES = 0.82) set configurations. Traditional and rest redistribution set configurations are equally effective to improve lower-body explosive strength, lower-body strength endurance, and upper-body explosive strength, whereas rest redistribution set configurations could induce greater adaptations in upper-body strength endurance.
Selective Effect of Different High-Intensity Running Protocols on Resistance Training Performance
Authors: Pérez-Castilla Alejandro , García-Pinillos Felipe , Miras-Moreno Sergio , Ramirez-Campillo Rodrigo , García-Ramos Amador , Ruiz-Alias Santiago A.
Published: February 2023

Pérez-Castilla, A, García-Pinillos, F, Miras-Moreno, S, Ramirez-Campillo, R, García-Ramos, A, and Ruiz-Alias, SA. Selective effect of different high-intensity running protocols on resistance training performance. J Strength Cond Res 37(6): e369–e375, 2023—This study aimed to explore the acute effect of 2 high-intensity running protocols (high-intensity interval training [HIIT] and sprint interval training [SIT]) on resistance training (RT) performance and their combined effect on the lower-body maximal neuromuscular capacities. Eighteen healthy subjects randomly completed 3 experimental protocols: only RT, HIIT + RT, and SIT + RT. Characteristics of the RT protocol include 3 back-squat sets of 10 repetitions or 20% velocity loss against 60% of 1 repetition maximum with 3 minutes of interset rest. Characteristics of the high-intensity running protocols include HIIT (4 intervals of 4 minutes at ∼110% of functional threshold power with 3 minutes of interinterval rest) and SIT (6 all-out sprints of 30 seconds with 4 minutes and 24 seconds of interinterval rest). The force-velocity relationship (maximal values of force [F
0], velocity [v
0], and power [Pmax]) was evaluated at the beginning and at the end of each experimental protocol. The number of back-squat repetitions (p = 0.006; effect size [ES] = −0.96), fastest velocity (p = 0.003; ES = −0.63), and average velocity (p = 0.001; ES = −0.73) were lower for the SIT + RT protocol compared with the RT protocol, but no significant differences were observed between the RT and HIIT + RT (p ≥T0.057; ES ≤.−0.46, except −0.82 for the number of back-squat repetitions) and HIIT + RT and SIT + RT (p ≥T0.091; ES .0−0.35) protocols. The 3 protocols induced comparable decreases in v

0
and Pmax (F
(2,34) 2,0.96; p ≥ 0.393), but F

0
tended to decrease after the SIT + RT protocol and to increase after the RT and HIIT + RT protocols (F
(2,34) = 4.37; p = 0.035). Compared with RT alone, the data suggest that SIT deteriorates RT quality and F
0 capacity more than long-interval HIIT.
Position-Specific Running and Technical Demands During Male Elite-Junior and Elite-Senior Australian Rules Football Match-Play
Authors: Jennings Jacob , Štaka Zorana , Wundersitz Daniel W. , Sullivan Courtney J. , Cousins Stephen D. , Čustović Edhem , Kingsley Michael I.
Published: February 2023

Jennings, J, Štaka, Z, Wundersitz, DW, Sullivan, CJ, Cousins, SD, Čustović, E, and Kingsley, MI. Position-specific running and technical demands during male elite-junior and elite-senior Australian rules football match-play. J Strength Cond Res XX(X): 000–000, 2022—The aim of this study was to compare position-specific running and technical demands of elite-junior and elite-senior Australian rules football match-play to better inform practice and assist transition between the levels. Global positioning system and technical involvement data were collated from 12 Victorian U18 male NAB League (n = 553) and 18 Australian Football League (n = 702) teams competing in their respective 2019 seasons. Players were grouped by position as nomadic, fixed, or ruck, and data subsets were used for specific analyses. Relative total distance (p = 0.635, trivial effect), high-speed running (HSR) distance (p = 0.433, trivial effect), acceleration efforts (p = 0.830, trivial effect), deceleration efforts (p = 0.983, trivial effect), and efforts at >150 m·min−1 (p = 0.229, trivial effect) and >200 m·min−1 (p = 0.962, trivial effect) did not differ between elite-junior and elite-senior match-play. Elite juniors covered less total and HSR distance during peak periods (5 seconds–10 minutes) of demand (p ≤ 0.022, small-moderate effects). Within both leagues, nomadic players had the greatest running demands followed by fixed position and then rucks. Relative disposals (p = 0.330, trivial effect) and possessions (p = 0.084, trivial effect) were comparable between the leagues. During peak periods (10 seconds to 2 minutes), elite juniors had less technical involvements than elite seniors (p ≤ 0.001, small effects). Although relative running demands and positional differences were comparable between the leagues, elite juniors perform less running, HSR, and technical involvements during peak periods when compared with elite seniors. Therefore, coaching staff in elite-senior clubs should maintain intensity while progressively increasing the volume of training that recently drafted players undertake when they have transitioned from elite-junior leagues.
Assessing Injury Susceptibility at Marine Corps Recruit Depot, San Diego, California
Authors: Poh Paula Y.S. , Sessoms Pinata H. , Haluch Kathrine S. , Trone Daniel W.
Published: February 2023

Poh, PYS, Sessoms, PH, Haluch, KS, and Trone, DW. Assessing injury susceptibility at Marine Corps Recruit Depot, San Diego, California. J Strength Cond Res XX(X): 000–000, 2022—Marine Corps Recruit Depot (MCRD) recruits undergo demanding training. Musculoskeletal injury (MSKI) accounts for attrition and graduation delays. Functional tests, such as Functional Movement Screen (FMS), Y-Balance Test-Lower Quarter (YBT-LQ), and ankle dorsiflexion range of motion (AD-ROM), may identify individuals at greater MSKI risk. This study tested the hypothesis that functional assessments may inform injury prediction. Male recruits (N = 407; mean ± SD: age, 20 ± 2 years) performed baseline functional tests. Marine Corps Recruit Depot staff tracked MSKI and graduation outcomes. The chi-square test of independence (individual FMS exercises) and Mann-Whitney U (FMS composite score) test examined the relationship between FMS and MSKI incidence. One-way analysis of variance compared YBT-LQ and AD-ROM with MSKI incidence. Twelve recruits (3%) incurred a lower extremity MSKI and were dropped. Of those 12, 9 had a delayed graduation, and 3 separated from enlistment. The level of significance was set at p < 0.10 to identify between-group differences (yes-MSKI vs. no-MSKI). Functional movement screen composite score (p = 0.064), hurdle step (p = 0.059), and trunk stability (p = 0.001) were lower in yes-MSKI. Y-Balance Test-Lower Quarter anterior direction difference between legs (p = 0.011) and AD-ROM right side (p = 0.055) was greater in yes-MSKI. Odds ratios (OR) were calculated using cut-off scores, with strong odds of sustaining MSKI with FMS trunk stability score <2 (OR: 7.56, 95% confidence interval [CI]: [2.32, 24.61]) and YBT-LQ anterior difference >6.25 cm (OR: 6.38, 95% CI: [1.98, 20.55]). Recruits who incurred MSKI had scores that indicated lesser mobility and stability of the lower extremity, providing preliminary evidence that when assessed together, FMS, YBT-LQ, and AD-ROM, may have predictive value for identifying those at MSKI risk.
Time Course Evaluation of Mitogen-Activated Protein Kinase Phosphorylation to Resistance Exercise: A Systematic Review
Authors: Lee Christopher J. , Nicoll Justin X.
Published: February 2023

Lee, CJ and Nicoll, JX. Time course evaluation of mitogen-activated protein kinase phosphorylation to resistance exercise: a systematic review. J Strength Cond Res 37(3): 710–725, 2023—Resistance exercise (RE) can increase the signaling activities of mitogen-activated protein kinases (MAPKs), specifically extracellular signal-regulated kinases 1/2 (ERK1/2), p90 ribosomal S6 kinases (p90RSK), c-Jun NH2-terminal kinases (JNK), and p38-MAPK. These RE-induced responses contribute to various intracellular processes modulating growth and development in skeletal muscles, playing an essential role in resistance training adaptations. The time course of MAPK phosphorylation to different RE conditions, such as training experience and varying loads, remains ambiguous. A systematic review was conducted to determine the effects of different post-RE recovery time points on the MAPK signaling cascade. In addition, the effects of loading and training statuses on MAPK responses were also investigated. The review was performed according to the preferred reporting items for systematic reviews and meta-analyses guidelines with a literature search incorporating 3 electronic databases. A modified version of the Downs and Black checklist was used to evaluate the methodological quality of the studies. The signaling responses were measured within a time range between immediately post-RE and >6 hours post-RE. Forty-four studies met the inclusion criteria, and all were classified as good-to-moderate methodological quality. Mitogen-activated protein kinase phosphorylation increased to different levels after RE, with the highest near the cessation of exercise. Although overall signaling was attenuated among trained individuals likely because of training adaptations, greater MAPK responses can be attributed to moderate loads of 65–85% 1RM regardless of the training experience. However, specific training-induced responses remain equivocal, and further investigations are required to determine the ideal training parameters to optimize anabolic intramuscular signaling, which may likely optimize resistance training adaptations.
Power, Endurance, and Body Composition Changes Over a Collegiate Career in National Collegiate Athletic Association Division I Women Soccer Athletes
Authors: McFadden Bridget A. , Bozzini Brittany N. , Cintineo Harry P. , Hills Samuel P. , Walker Alan J. , Chandler Alexa J. , Sanders David J. , Russell Mark , Arent Shawn M.
Published: February 2023

McFadden, BA, Bozzini, BN, Cintineo, HP, Hills, SP, Walker, AJ, Chandler, AJ, Sanders, DJ, Russell, M, and Arent, SM. Power, endurance, and body composition changes over a collegiate career in National Collegiate Athletic Association Division I women soccer athletes. J Strength Cond Res XX(X): 000–000, 2022—The purpose of this study was to determine longitudinal changes in fitness and body composition throughout athletes' 4-year collegiate soccer careers. Performance testing occurred before preseason during freshman, sophomore, junior, and senior year in 17 female Division I soccer players. Body composition was assessed through air-displacement plethysmography to determine percent body fat (%BF), fat-free mass (FFM), and body mass (BM). Maximal countermovement vertical jump height was assessed through contact mat using arm swing (CMJAS) and hands-on-hips (CMJHOH) methods to calculate power (CMJwatts/HOHwatts). Aerobic capacity (V̇o
2max) and ventilatory threshold (VT) were assessed by indirect calorimetry during a maximal graded exercise test on a treadmill. Linear mixed models were used to assess changes across academic years (p < 0.05). No changes occurred in %BF, BM, V̇o
2max, VT, CMJAS, or CMJwatts. A time main effect was seen for FFM (p = 0.01) with increases from freshman to senior (p = 0.02). Time main effects were observed for CMJHOH (p < 0.001) and CMJHOHwatts (p < 0.001) with increases from freshman to junior (CMJHOH,
p = 0.001; CMJHOHwatts, p = 0.02) and senior (CMJHOH, p < 0.001; CMJHOHwatts, p = 0.003) as well as sophomore to senior (CMJHOH, p < 0.001; CMJHOHwatts, p = 0.02). Countermovement vertical jump with hands on hips also increased from sophomore to junior (p = 0.005). The lower FFM and power capabilities as freshmen compared with upperclassman indicate a potential limited readiness. Coaches and training staff should account for these developmental differences when entering the preseason. Adequate conditioning programs before starting a collegiate program may help build a fitness foundation and prepare freshmen athletes to compete at the same level as their upperclassmen counterparts.
The Acute Effect of High-Intensity Resistance Training on Subsequent Firefighter Performance
Authors: Mason M. Ryan , Heebner Nicholas R. , Abt John P. , Bergstrom Haley C. , Shapiro Robert , Langford Emily L. , Abel Mark G.
Published: February 2023

Mason, MR, Heebner, NR, Abt, JP, Bergstrom, HC, Shapiro, R, Langford, EL, and Abel, MG. The acute effect of high-intensity resistance training on subsequent firefighter performance. J Strength Cond Res 37(7): 1507–1514, 2023—High-intensity resistance training (HIRT) is commonly performed by structural firefighters on duty to enhance occupational readiness. However, exercise-induced fatigue may negatively impact subsequent occupational performance. Therefore, the purpose of this study was to assess the acute effect of HIRT on subsequent occupational physical ability in structural firefighters and to determine the time course of recovery. Seven resistance-trained male firefighters performed a timed maximal effort simulated fireground test (SFGT) in 3 randomized conditions: baseline (SFGTbaseline), 10 minutes post HIRT (SFGT10min), and 60 minutes post HIRT (SFGT60min). Work efficiency and air depletion were assessed during the SFGT. The timed HIRT session consisted of a standardized set of exercises using absolute training loads. Repeated measures analysis of variance and minimal difference (MD) analysis assessed group and individual effects between the conditions, respectively. The level of significance was set at p < 0.05. SFGT10min completion time was greater than SFGTbaseline (430 ± 137 vs. 297 ± 69 seconds, p < 0.01), with no difference between SFGTbaseline and SFGT60min (297 ± 69 vs. 326 ± 89 seconds, p = 0.08). The MD analysis indicated that all firefighters' SFGT10min times exceeded the MD (±26.4 seconds) compared with SFGTbaseline. However, 43% of firefighters still exceeded the MD at SFGT60min. Air depletion during SFGT10min was greater than that during SFGTbaseline (2,786 ± 488 vs. 2,186 ± 276 lb·in−2, p = 0.02), with no difference between SFGTbaseline and SFGT60min (p = 0.25). Work efficiency during SFGT10min was 40% lower than that during SFGTbaseline (p < 0.01), with no difference between SFGTbaseline and SFGT60min (p = 0.25). These findings indicate that an acute bout of HIRT decreases multiple descriptors of firefighters' occupational performance 10 minutes post exercise with varied responses at 60 minutes post exercise.
Comparative Effects of Contrast Training and Progressive Resistance Training on Strength and Power-Related Measures in Subelite Australian Rules Football Players
Authors: Schneiker Knut T. , Fyfe Jackson J. , Teo Shaun Y.M. , Bishop David J.
Published: February 2023

Schneiker, KT, Fyfe, JJ, Teo, SYM, and Bishop, DJ. Comparative effects of contrast training and progressive resistance training on strength and power-related measures in subelite Australian Rules Football players. J Strength Cond Res XX(X): 000–000, 2022—The aim of this study was to determine whether contrast training (CST) elicits superior strength-related and power-related outcomes compared with progressive resistance training (PRT). Sixteen male amateur Australian Rules Football players (age, 19 ± 2 years; height, 183 ± 8 cm; body mass, 78.5 ± 8.8 kg; mean ± SD) completed 2 weeks of standardized resistance training followed by 6 weeks of either CST or PRT. Both CST and PRT improved absolute (20 and 19%) and relative (19 and 16%) 1 repetition maximum (1RM) half squat strength, absolute (8.7 and 8.7%, respectively) and relative (8.2 and 6.1%, respectively) squat jump peak power, and 20-m sprint performance (5.4 and 4.7%, respectively), including both 0 to 5 m (15 and 14%, respectively) and 0 to 10 m (8.6 and 7.5%, respectively) splits. Vertical jump height only improved with CST (6.5%), whereas body mass only increased after PRT (1.9%). There were negative associations between the baseline power-to-strength ratio (PSR) and improvements in both absolute (r
2 = 0.51 and 0.72 for CST and PRT, respectively) and relative (r
2 = 0.65 and 0.60 for CST and PRT, respectively) squat jump peak power. There were no statistically significant (i.e., p ≥ 0.05) between-group differences for all training outcomes. Both interventions improved various strength-related and power-related measures, although a lower baseline PSR was associated with greater improvements in power-related outcomes after both interventions. Contrast training is therefore an effective alternative to progressive resistance training during relatively short-term (6–8 weeks) training periods in young, male, team-sport athletes, particularly in those with a lower power-to-strength ratio.
Cross-Sectional Analysis of Ground Reaction Forces During Jumps in Professional Baseball Players
Authors: Amonette William E. , Vazquez Jose , Coleman A. Eugene
Published: February 2023

Amonette, WE, Vazquez, J, and Coleman, AE. Cross-sectional analysis of ground reaction forces during jumps in professional baseball players. J Strength Cond Res 37(8): 1616–1622, 2023—This study described and compared force plate kinetics in major (MLB) and minor (MiLB) baseball players while performing vertical jumps (CMVJ), squat jumps (SSJ), and depth jumps (DJ). Second, comparisons were made between playing positions. Data were collected on 101 professional baseball players. Peak force, eccentric and concentric impulses, peak power, and jump height were determined from each test. Reactive strength index was computed from the DJ. Data were compared using factorial analysis of variances, alpha was set at p ≤ 0.05, and effect sizes were reported using Cohen's d. During CMVJ, MiLB players generated more force (p = 0.04; d = 0.48), power (p = 0.02; d = 0.42), and jumped higher (p = 0.03; d = 0.32) than MLB players. Pitchers generated higher propulsive impulses than catchers (p = 0.004; d = 0.93). Outfielders generated more power (p = 0.02; d = 0.98) and jumped higher (p = 0.049; d = 1.08) than catchers and infielders (p = 0.025; d = 0.32). Minor league baseball players generated more force (p = 0.002; d = 0.62), power (p = 0.001; d = 0.84), and jumped higher (p = 0.02; d = 0.48) than MLB players in SSJ. No differences were observed by position in SSJ. Minor league baseball players jumped higher than MLB players in the DJ (p = 0.01; d = 0.57) and outfielders generated more power in the DJ than pitchers (p = 0.05; d = 0.43) and catchers (p = 0.007; d = 1.61). Reactive strength index was greater in outfielders compared with catchers (p = 0.01; d = 1.20). These data indicate that MiLB players were generally more powerful and jumped higher than MLB players in the 3 performance tasks. The difference observed by playing level were likely related to physical preparedness at the beginning of spring training; positional differences were the result of athletic skill sets required for tactical excellence at each position.
Anthropometric Evaluation of First Round Draft Selections in Major League Baseball
Authors: Crotin Ryan L. , Conforti Christian M. , Szymanski David J. , Oseguera Jordan
Published: February 2023

Crotin, RL, Conforti, CM, Szymanski, DJ, and Oseguera, J. Anthropometric Evaluation of first round draft selections in Major League Baseball. J Strength Cond Res 37(8): 1609–1615, 2023—Physical stature effects on future Major League Baseball (MLB) performance and player evaluation are not known among amateurs. Amateur athletes with greater stature were expected to perform at a higher MLB level, play first base or catcher, be drafted earlier, begin earlier MLB careers, and receive higher signing bonuses compared with lower stature players. Publicly available high-school amateur data on 319 first round player selections from 2005 to 2015 identified athletes' body mass, heights, and body mass index (BMI) to determine impacts on MLB Wins Above Replacement (WAR) ratings, draft selection number, signing bonuses, position, educational background, innings pitched, and plate appearances before making an MLB debut. Student t tests split sample data above and below the median to examine mean differences for body mass, height, and BMI, whereas one-way analysis of variance with Bonferroni correction calculated first round selection groups and positional differences in anthropometry at an a priori alpha level of p ≤ 0.05. First basemen and catchers had the highest BMI of all positions (p < 0.05, d > 0.80), high-school signees had higher BMI than collegiate signees during high-school years (p < 0.03, d > 0.05), the first 5 selections had higher BMI than the last 5 selections in the first round (p < 0.05, d = 0.38), all with moderate-to-large effects. High-school pitchers with less body mass reached the MLB level in less innings than heavier pitchers (p < 0.001, d = 0.62). No anthropometric differences were seen in player WAR ratings. Results indicate a scouting preference toward high-school athletes with greater BMI, yet high-school anthropometrics seem to not influence future MLB performance.
Athlete External Loads Across a Collegiate Men's Lacrosse Season
Authors: Fields Jennifer B. , Jones Margaret T. , Feit Mary Kate , Jagim Andrew R.
Published: February 2023

Fields, JB, Jones, MT, Feit, MK, and Jagim, AR. Athlete external loads across a collegiate men’s lacrosse season. J Strength Cond Res 37(8): e455–e461, 2023—Tracking and quantifying athlete workload may provide insight into best practice periodization strategies and workload management. Limited information exists detailing the external demands associated with collegiate men's lacrosse. Therefore, the purpose of this study was to investigate and compare practice, game, and positional differences across a lacrosse season. Male collegiate lacrosse athletes (n = 17; body mass: 79.9 kg ± 9.7 kg; body fat %: 14.7 ± 3.8%) wore a global positional system device during practices (n = 66) and games (n = 19). External load metrics were total distance (TD), sprint distance (SD), accelerations (>3 m·s−2), sprint efforts, player load (PL), PL/min, and top speed. Multiple analysis of variances assessed differences in external loads across session (practice versus game) and sport position (attackers, midfielders, and defenders). A 3 × 4 analysis of variance was used to determine a position-by-time (first quarter [Q1], second quarter [Q2], third quarter [Q3], and fourth quarter [Q4]) interaction (p < 0.05). Total distance (p < 0.001, η
2: 0.047), SD (p < 0.001, η
2: 0.093), sprint efforts (p < 0.001, η
2: 0.077), PL (p < 0.001, η
2: 0.022), and top speeds (p < 0.001, η
2: 0.086) were all higher in games compared with practices. Attackers and defenders covered more TD (p < 0.001, η
2 = 0.0257), accelerations (p < 0.001, η
2 = 0.126), PL (p < 0.001, η
2 = 0.233), and PL/min (p < 0.001, η
2 = 0.193) than midfielders. Attackers and midfielders covered more SD (p = 0.002 η
2 = 0.043), sprint efforts (p < 0.001, η
2 = 0.053), and achieved higher top speed (p < 0.001, η
2 = 0.0063) than defenders. Volume and intensity metrics declined by Q4 in attackers and defenders (p < 0.05), whereas external load measures did not differ across quarters for midfielders. Monitoring in-game external loads can assist coaches with individualizing training programs and preparing athletes for game demands.
Evaluating the Effect of Incorporating Slag Cement with Pre-wetted Lightweight Aggregate on Reducing Cracking of Concrete Bridge Decks
Authors: Hamid Waleed K. , Khoury Issam , Mandadapu Mahendra , Al Rikabi Fouad T. , Ali Hajir
Published: February 2023

Early-age cracking is a severe problem in concrete bridges because it reduces the durability of the superstructure. One of the techniques to minimize early-age cracks is the addition of pre-wetted lightweight aggregate (LWA). There is limited research regarding the effect of pre-wetted LWA on the early-age performance of concrete. This paper aims to evaluate the efficiency of incorporating slag cement with pre-wetted LWA to reduce the potential cracking of the concrete decks. Also, the effect of fly ash on the shrinkage properties of concrete was investigated. Mixtures used in this study consist of replacements of total aggregate with pre-wetted LWA and partial replacements of cement with slag cement or fly ash. The performance of concrete specimens containing slag cement with pre-wetted LWA was evaluated in terms of mechanical properties, plastic shrinkage, free shrinkage, and restrained shrinkage. The results showed that the tensile strength was not the most significant parameter affecting the cracking potential of the concrete. The cracking potential of the concrete was strongly related to the tensile strength and free shrinkage. It was observed that incorporating slag cement with pre-wetted LWA significantly enhances the early-age performance of concrete as the tested specimens showed no sign of cracks. The results also showed that the shrinkage of the mixtures containing coarse LWA was reduced by 43 % compared with the control mixture. Moreover, it was noted that the LWA with higher absorption increases plastic shrinkage cracks for concrete decks under severe conditions.
Modeling of the Three-Dimensional Point Cloud Based on the Binocular Stereovision and Structure Identification
Authors: Wang Peitao , Zhang Bo , Haishaer Daowuerjiang , Zhu Chencheng , Cai Meifeng
Published: February 2023

The existence of weak planes affects the stability of rock engineering, especially the failure modes of the surrounding rocks. Therefore, investigation of the structural planes of rock mass and the extraction of discontinuities is important for rock mechanics. In this work, the LenaCV binocular stereovision system was studied and applied to establish three-dimensional (3D) surface models. Calibration of the binocular camera parameters, optimal distance discussion, and 3D modeling optimization were conducted. The optimal measuring distance and the intrinsic parameters suitable for the LenaCV stereovision were discussed. Finally, the 3D reconstruction of two case studies was carried out and the 3D point cloud modeling was established. The structural discontinuity mapping in rock faces was also carried out. The feasibility of the binocular stereovision system, as well as the optimum baseline distance, was discussed and verified. The study results can provide a new platform for the economic investigation of 3D rock mass structures and provide a new approach for the efficient extraction of rock mass discontinuities.