bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential of graded doses of neem (Azadirachta indica) seed oil on ruminal fermentation characteristics, degradability, and methane formation in vitro
Authors: Al-Marzooqi Waleed , Sallam Sobhy M. , Alqaisi Othman , El-Zaiat Hani M.
Published: November 2021

Neem (Azadirachta indica) belongs to Meliaceae family, represented mainly by trees, and widely cultivated and adapted in many tropical regions. The objective of this study was to evaluate the effect of increasing doses of neem seed oil (NSO) on ruminal methane (CH4) formation, diet degradability, and fermentation characteristics after 24 h of in vitro incubation. Treatments were randomly designed to four doses of NSO supplemented to the basal diet (0, 20, 40, or 60 ml/kg DM). Increasing NSO dose resulted in a quadratic decrease (P < 0.05) in net gas (expressed as ml/g DM and ml/g TDOM) and CH4 (expressed as ml/g TDNDF) production, while CH4 (expressed as ml/g TDOM), acetate and propionate proportions decreased linearly confirming a dose-related effect. A quadratic increase in TDOM and linear increase (P = 0.023) in DNDF, NH3-N concentrations, and total protozoal counts were observed. However, a linear increase (P = 0.009) was found in the ruminal butyrate proportion and partitioning factor as dietary NSO supplementation increased. In conclusion, dietary NSO supplementation mediated some desirable fermentation patterns, reducing ruminal NH3-N concentration and CH4 production with some adverse effects on fiber degradability. However, practical research under long-term conditions is required for further investigation.
Prenatal programming of the small intestine in piglets: the effect of supplementation with 3-hydroxy-3-methylbutyric acid (HMB) in pregnant sows on the structure of jejunum of their offspring
Authors: Tomaszewska Ewa , Prost Łukasz , Dobrowolski Piotr , Chand Deepesh K.P. , Donaldson Janine , Czech Anna , Klebaniuk Renata , Fabjanowska Julia , Muszyński Siemowit
Published: November 2021

When discussing the scale of the occurrence of diseases of the digestive system in farm animals, particularly pigs in the weaning period, it may be beneficial to study physiological and nutritional factors that could potentially affect the growth, development, and modelling of the structure and function of the digestive tract. Taking into account the reports on the beneficial effects of ß-hydroxy-ß-methylbutyrate (HMB) administration in the prenatal period on the development of various systems it was assumed that the HMB supplementation to pregnant sows can influence intestinal development in the offspring during weaning. Thus, the present experiment was conducted to evaluate the effect of HMB treatment of pregnant sows on jejunum development in offspring at weaning. From 70th day until the 90th day of gestation, sows received either a basal diet (n = 12) or the same diet supplemented with HMB (n = 12) at the dose of 0.2 g/kg of body weight/day. HMB given during prenatal time reduced the thickness of the longitudinal muscle; the apoptotic cell index in epithelium also significantly decreased after the HMB supplementation. Vasoactive intestinal (poly)peptide (VIP) expression in submucosal ganglia significantly increases in prenatally HMB treated piglets. The same strong reaction was observed with the expression of occludin, claudin-3, E-cadherin, and leptin in the jejunal epithelium. The obtained results indicate that the administration of HMB to pregnant sows significantly influenced the expression of VIP, leptin and some proteins of the intestinal barrier of their offspring less influencing the basal morphology.
Breast muscle myopathies in broiler: mechanism, status and their impact on meat quality – A review
Authors: Nawaz Ali Hassan , Zheng Jia Hui , Zhang Wei Lu , Wang Fu Jian , Jiao Zheng Hai , Amoah Kwaku , Zhang Li
Published: November 2021

Almost a decade ago, the sudden rise of breast muscle defects in fast-growing commercial broiler breeds challenged the broiler production industry and meat scientists to address the issue of these novel muscle abnormalities. After that, a widespread hypothesis showing a correlation between high muscle yield and incidence of these muscle myopathies received much acceptance from the research community. Increased muscle hypertrophy and unbalanced growth of connective tissues lead to an inadequate blood supply that ultimately causes hypoxia in muscle fibers. Reduced blood vascular density in muscle fibers induces oxidative stress and mitochondrial dysfunction, leading to muscle fibrosis, lipidosis and myodegeneration. Along with physical changes, the myopathic muscles exhibit poor sensory properties, abnormal texture properties and a low nutritional profile. As these myopathies alter meat’s physical appearance, they have a negative impact on customer’s behavior and preference. A better production environment with proper dietary supplementation with balanced breeding strategies can minimize the incidence of muscle myopathies in broiler chicken. This review aims to address the underlying mechanism behind these myopathies and their impact on poultry meat quality, including nutritional value and consumer behavior. It describes the link between genetic and non-genetic elements influencing myopathies, along with the strategies to minimize the occurrence of breast muscle myopathies.
The effect of light/dark cycles on performance and welfare in broiler
Authors: Ozkan Murat , Simsek Ulku Gulcihan
Published: November 2021

The purpose of this study was to compare a continuous lighting programme (23 hours of lighting (L)/1 hour of darkness (D)) with intermittent lighting programmes (16L: 8D) and also to investigate the effects of the length of the dark cycle in the intermittent programme on the performance, carcass characteristics, water consumption, uniformity, metabolic parameters, and ammonia burns of chickens. Thus, five hundred Ross 308 male chicks were used. The 23L:1D programme was applied to the chicks for 7 days. On day 7, they were divided into four groups by balancing their live weight; group I: continuous 23L:1D; group II: intermittent 4x (4L:2D); group II: intermittent 2x (8L:4D); group IV: continuous 16L:8D. The study took place between days 7 and 42. At the end of the study, 10 chickens from each group were slaughtered, their carcass, blood, and bone properties were analysed. Body temperatures and ammonia burns were assessed for all broiler chickens. The mean live weight of group IV was the lowest. The difference among the groups in terms of live weight gains, feed intakes, feed conversion ratios, and survival rates was non-significant. Long-term darkness in group IV significantly dropped the water consumption. On day 21, group III’s best uniformity was calculated; but on day 42, the difference was non-significant. The highest breast ratio and the lowest wing ratio belonged to chicks in group I. Their free T4, glucose, and uric acid levels were lower; whilst their testosterone levels were higher. Body temperature and tibia ash levels were similar across all of the groups. The intermittent lighting programmes increased the number of ammonia burns. Consequently, the long-term darkness negatively affected both the chickens’ performance and well-being.
Dose-response effects of the Savory (Satureja khuzistanica) essential oil and extract on rumen fermentation characteristics, microbial protein synthesis and methane production in vitro
Authors: Golbotteh Mostafa Mehdipour , Malecky Mostafa , Aliarabi Hasan , Zamani Pouya , Ganjkhanlou Mehdi
Published: November 2021

The objective of the present study was to investigate dose-response effects of the essential oil (EO) and dry extract (EX) of Satureja khuzistanica (SK) on in vitro gas production kinetics, rumen fermentation, ruminal methanogenesis and microbial protein synthesis. So, EO and EX were tested at 0 (as control); 150 (low dose); 300, 450 (intermediate doses) and 600 mg/L (high dose). The gas produced over 24 h of incubation (GP24) decreased linearly with both EO and EX dosages (P<0.01). In vitro methane production was reduced by both EO (14–69%, depending on the included dose) and EX (7–58%). Microbial protein (MP) as well as the efficiency of microbial protein synthesis (EMPS) were improved by EO (18.8–49.8% and 20.4–61.5% for MP and EMPS, respectively) and to a lesser extent by EX (8.3–25.7% and 4.6–24.2% for MP and EMPS, respectively). Ammonia concentration was dropped in linear and quadratic manners with EO (P<0.05), and linearly with EX dosages (P<0.01). EO and EX exhibited depressive effects (in linear and quadratic (P<0.05), and linear manners (P<0.01), respectively) on total protozoa count. A mixed linear and quadratic effect was observed from both EO and EX on total VFA concentration (P<0.01). Total VFA concentration increased at 300 mg/L of EX, but decreased at high dose of both EO and EX. The acetate proportion increased with EO intermediate and high dosages, but it decreased at the expense of propionate at low and intermediate doses of EX. In total, these findings confirmed previous research on the great capacity of plant-based feed additives in positively modulating rumen fermentation that their effects may vary depending on the doses used. Specifically, these results suggest that EO and EX have high potentials to improve rumen functions at intermediate doses, which needs to be confirmed by in vivo experiments.
Dietary silage supplement modifies fatty acid composition and boar taint in pork fat
Authors: Argemí-Armengol Immaculada , Villalba Daniel , Bertolín Juan Ramón , Latorre María Ángeles , Panella-Riera Núria , Álvarez-Rodríguez Javier
Published: November 2021

In organic pig husbandry, the use of roughage is mandatory as dietary supplement. This study investigated the effects of oat silage on the fatty acid composition, in entire males and gilts, as well as indole and skatole levels in perirenal adipose tissue of entire males. Entire males and gilts (forty-five to forty-eight pigs/sex) were assigned to two dietary roughage feeds (control with straw vs. oat silage). There was no significant effect of silage or sex on total SFA and MUFA in pork fat. However, the oat silage increased the total PUFA n-3 and decreased the PUFA n-6/n-3 ratio. The content of boar taint compounds (skatole and indole) in the entire male pigs did not differ between diets, although human nose scoring rejected in a greater extent more pork fat from entire males supplemented with oat silage, compared with those only supplied with straw. Approximately 50% of the entire males (90 to 97 kg of carcass) had low skatole values (≤0.1 μg/g), that were below the range of boar taint detection, regardless of the feeding regime. This finding indicates that more studies should be performed to avoid the problem of taint detection in entire males under organic production.
Profitability and Impact of Inorganic Fertilizers on the Maize Production in Ekona, Cameroon
Authors: Nanganoa Lawrence Tatanah , Ngome Francis Ajebesone , Ngong Juliana Namein , Atache Sone Kone Edigar , Ebonlo Jeremiah Ndande , Njukeng Jetro Nkengafac
Published: November 2021

Declining soil fertility and low fertilizer use are the major abiotic factors limiting the maize production in Cameroon. Therefore, the design and introduction of appropriate fertilizer schemes, which would improve maize yields and provide incentives for smallholder farmers, are considered imperative. In 2018, a field experiment was conducted on the farm of the Institute of Agricultural Research for Development (IRAD) in Ekona, the south-west region of Cameroon, to investigate the profitability and impact of inorganic fertilizers on maize production. The experiment was laid out in a randomized complete block design with four replications and four treatments, using different fertilizer rates per hectare in each treatment (namely unfertilized control (T1), 50 kg urea + 50 kg N-P-K (T2), 100 kg urea + 100 kg N-P-K (T3) and 150 kg urea + 150 kg N-P-K (T4)). The results obtained indicate that all the maize growth parameters (plant height, number of leaves per plant, stem girth and leaf area) and yield components considered (cob length, cob diameter and test weight of 100 grains) were significantly (P < 0.05) higher in T4 than T1. The grain yields recorded ranged from 4.09–5.88 t ha−1 and were also statistically (P < 0.05) higher in T4 than T1. The incremental income based on the fertilizer use was the highest in T4, followed by T3 and T2. The value cost ratio (VCR) was greater than 2 in all the treatments and was found to be highest in T2 (3.15), followed by T4 (2.52) and T3 (2.49). As T2, T3 and T4 did not differ statistically (P > 0.05), all the fertilizer rates considered were economically viable, but T4 provide the most cost-effective due to its higher grain yields and incremental income.
Influence of Total Production on the Planting Structure of Significant Vegetable Crops in the Republic of Serbia
Authors: Tekić Dragana , Novković Nebojša , Mutavdžić Beba , Pokuševski Maja , Zoranović Tihomir
Published: November 2021

The purpose of this paper is to examine, on the basis of the total production and distribution area parameters analyzed, a potential relationship between the actual production of major vegetable crops in Serbia in the current year and the following year’s distribution of planting areas devoted to the crops considered. The analysis was performed for the period 2005-2019. The results obtained indicate that the current year’s production of certain vegetable crops such as potatoes, cabbage, kale, peppers and beans affect the following year’s distribution of their planting areas.
A Mini Review of the Effects of NSP and Exogenous Enzymes in Broiler Diets on Digestibility and Some Intestinal Functions
Authors: Polovinski-Horvatović Miroslava
Published: November 2021

NSP (non-starch polysaccharides) are a large group of compounds, which vary greatly in their chemical structure and properties. They are linked with the use of some of the alternative proteins or energy feed ingredients in broiler nutrition. Exogenous enzymes which act on NSP are sometimes in broiler production with the purpose of increasing digestibility of nutrients and consequently increasing broiler performance in production. This paper will attempt to review changes occurring in the digestive tract as a result of the use of feed with NSP soluble and insoluble in water, and the effect of NSPase on them, in terms of how an animal organism is burdened or helped to overcome the problems.
Chlorophyll Fluorescence and Drought Tolerance in a Mapping Population of Durum Wheat
Authors: Larouk Chafia , Gabon Fatima , Kehel Zakaria , Djekoun Abdelhamid , Nachit Miloudi , Amri Ahmed
Published: November 2021

This study was conducted to compare and estimate the genetic variability among durum wheat lines in response to drought according to their grain yields and physiological traits. The use of fluorescence parameters as drought selection criteria for durum wheat was investigated in a population of 249 recombinant inbred lines (RILs) derived from a cross between two cultivars of durum wheat: ‘Svevo’ and ‘Kofa’. The durum wheat RILs considered were analyzed to determine the relationship between their grain yields and chlorophyll fluorescence parameters at the grain filling stage under drought stress (rainfed) and supplemental irrigation (irrigated) conditions during the 2004 and 2005 seasons at the ICARDA center. The results obtained show that the durum wheat line performance was influenced by drought stress, indicating significant differences between the grain yields and fluorescence parameters recorded under drought rainfed (RF) and irrigation (IR) conditions. Significant differences between the experimental groups of durum wheat RILs (P<0.05) were only recorded under drought conditions, with the exception of leaf water potential (Lwp). Under such conditions, nearly all the parameters examined were significantly increased in the high-yielding group (with the exception of the Que parameter), thus revealing the genetic variability of the durum wheat lines considered in response to drought stress. The potential quantum efficiency of photosystem II (Fv/Fm) was found to be positively associated with the grain yield parameter. The mean values of Fv/Fm in both the high- and low-yielding groups significantly dropped under drought stress (0.71 and 0.68, respectively) compared to the Fv/Fm values recorded under irrigated conditions (0.80 and 0.81). Under drought conditions, slopes were highly significant (P<0.001) nearly for all the fluorescence parameters examined (with the exception of CHLSPAD) compared to those recorded under irrigation conditions. It was concluded that chlorophyll content (SPAD), F0, Fm, Fv, Fv/Fm, Lwp, and Que could be used as additional indicators in screening wheat germplasm for drought tolerance.
Effect of Partial Substitution of Corn with Whole-Grain Wheat in Fattening Lamb Diets on their Growth Performance
Authors: Ivković Mirko , Krstović Saša , Polovinski-Horvatović Miroslava , Beuković Dejan , Pihler Ivan , Glamočić Dragan
Published: November 2021

Wheat grain is commonly used for animal feeding in some regions while it is rarely used in others. Its nutrient composition is quite similar to more commonly used corn grain, but there are some concerns regarding its effect on animal performance and health. However, it appears that usage of wheat grain in animal feeding is dominantly affected by economic rather than nutritional reasons. When used with caution, wheat can be a good alternative to corn. In order to test this, 20 Wurttemberg lambs, three months old, were randomly separated in two groups and fed diets containing 600 g of corn grain, or 300 g of corn grain and 300 g of wheat grain, for a period of one month. The used grains were whole, non processed grains. Two diets contained the same commercial protein supplement and alfalfa hay was offered ad libitum. Both groups accepted their experimental diet well and readily consumed the amounts offered. No health problems were observed. Growth rate was higher in male than in female lambs, but was not affected by wheat inclusion.
Creative Personal Identity and Creative Mindsets, and Their Implications for Creative Potential and Metacognition: A Latent Variable and a Latent Class Approach
Authors: Puente-Diaz Rogelio , Cavazos-Arroyo Judith
Published: November 2021

The amount of attention given to creative beliefs has increased in recent years. This article suggests that the selection of one´s best ideas from a set of self-generated alternatives should be included as an indicator of metacognition; something known as creative metacognition accuracy. The present investigation examined the role of creative mindsets and creative personal identity on the selection of one´s best idea, creative self-efficacy, and potential, under two conceptualizations of these beliefs: latent variables and latent classes. College business students completed a battery of questionnaires assessing creative mindsets, creative personal identity, and creative self-efficacy. In addition, participants completed a divergent thinking task involving improvement of smartphones an-d were asked to choose their best idea. Two independent judges also selected the best idea from participants’ set of self-generated ideas. Under the latent class conceptualization, a class with high levels of growth mindset and creative personal identity, and low levels of a fixed mindset showed higher levels of accurate idea selection and creative self-efficacy than the rest of the classes. Similarly, under the latent variable conceptualization, creative personal identity had a positive influence on accurate idea selection and creative self-efficacy.
Assessing Creativity from the Viewpoint of Law
Authors: Veiksa Ingrida
Published: November 2021

Originality is the main criterion for creating an author’s work. However, authors are often influenced by previous works of other authors that they have seen, heard or experienced. The aim of this study is to identify criteria for determining creativity in authors’ works, trying to find and define the difference between accidental influence and deliberate misappropriation or plagiarism. This article does not claim an in-depth analysis of creativity and originality from a social science perspective. It is more a scientific essay on creativity from a law science point of view, so that further research can be carried out in the field of authorship and its determination. In order to find an answer to the research question (Where does influence end and plagiarism begin?), theoretical framework and knowledge about creativity were observed, international and national laws were studied, case law from different countries was researched, materials of international conferences were examined, as well as information accessible on the Internet on copyright issues was observed. The research used a descriptive method to investigate the works of various researchers on the types of mutual influence, regulatory framework and court practice in this field, as well as a grammatical, systemic, teleological, and historical interpretation of legal norms to assess the inadequacy of existing legal norms and propose the necessary amendments in legislative enactments. The main result of this study is understanding that the factor of consciousness or subconscious forms the main criteria. If the influence is unintentional, the copyright of the original work is not infringed, but if repetition is intentional, when it goes beyond originality, the new work is considered to be an appropriation of authorship or plagiarism.
Visual Art Gifted Child in Pre-School and Early School Years
Authors: Podobnik Uršula , Selan Jurij
Published: November 2021

Visual arts media in pre-school and early school years and development of children’s drawing are well researched. However, when one considers that children are endowed with a talent for visual arts, the research is not as comprehensive and clear-cut. The signs of freedom of expression and imagination, intuitiveness and originality, an inclination to individual work, high sensitivity, and other indicators begin to show soon after visual art gifted (VAG) children enter the representative stages of visual arts. This article was based on a longitudinal case study that was carried out to show some aspects of the functioning of a VAG child in pre-school and early school years and to make some suggestions on how to consider the needs of VAG children.
How Groups Generate Creative Ideas? Interview with Roni Reiter-Palmon
Authors: Reiter-Palmon Roni , Lebuda Izabela
Published: November 2021

In the interview with Roni Reiter-Palmon, one of most prolific creativity researchers, we discuss her career, main areas of research interest, chosen research methods and share her thoughts about the future of research on creativity and effectiveness in scientific work.
Of Anthropophagy and Anthropology: Monsters and Men in Beowulf and Northwest Coast Myth and Ritual
Authors: Harkin Michael E.
Published: November 2021

Monsters can be divided into two categories: human-like and non-human. Non-human monsters tend to be chthonic beings that are associated with the earth and natural forces. Humanoid monsters represent metaphorical transformations of humanity itself, and as such reveal basic cultural values, such as sociability, while displaying their opposite. Humanoid monsters are the more terrifying, precisely because we recognize ourselves in them, although in an uncanny refraction. In the epic poem Beowulf and in myth and ritual of the Kwakiutl and Heiltsuk cultures of the Northwest Coast, manlike monsters play a central role.
A Monstrous Morality: Tzitzimime and their Relatives as Enforcers of Social Control
Authors: Hudson Kathryn M. , Henderson John S.
Published: November 2021

The tzitzimime – as reflected in central Mexican ethnohistorical sources and precolumbian imagery – represent a diverse array of mostly female divinities associated with fertility. Under Spanish influence, they were re-conceptualized as malevolent, mostly male agents of the Christian devil. Related beings attested elsewhere, especially in the ethnography of eastern Mesoamerica, are distinctly monstrous. They are particularly salient in “wild” contexts, outside the realm of culture, and serve as enforcers of social norms. This paper traces the development of these creatures from their quasi-monstrous tzitzimime forbears and considers how they have been – and continue to be – conceptualized in relation to sociopolitical differences in their cultural contexts.
Effects of Post-Activation Performance Enhancement (PAPE) Induced by a Plyometric Protocol on Deceleration Performance
Authors: Ciocca Gianmarco , Tschan Harald , Tessitore Antonio
Published: November 2021

Post-Activation Potentiation (PAP) is a phenomenon which can improve power performance executed after a previous conditioning activity. PAP is usually evoked through heavy resistance or plyometric exercise. It has been suggested to refer to as Postactivation Performance Enhancement (PAPE) when research is field-based on explosive activities. To our best knowledge, no studies have investigated the effects of PAPE on deceleration performance, which is a key factor in sports involving change of directions. Therefore, the aim of this study was to investigate the influence of a plyometric exercise protocol on a subsequent deceleration running performance. University soccer players (n = 18) performed seven deceleration trials and were assessed at baseline and after ~15 s, 2, 4, 8, 12 and 16 min either following a walking control condition (C) or three sets of ten repetitions of alternate-leg bounding (plyometric, P). Results showed no significant differences at any of the trials under the control condition (C) in comparison to the relative baseline. Under the plyometric condition (P), deceleration performance executed two minutes after the plyometric activity resulted in significantly faster results compared to the baseline values (p = 0.042; ES = 0.86, large effect; % of improvement = 4.13 %). The main findings are that plyometric exercise improves a subsequent running deceleration performance, 2 min after its execution. Future investigations should focus on more complex actions such as changes of direction and agility.
Biomechanical Effects of Flamenco Footwork
Authors: Vargas-Macías Alfonso , Baena-Chicón Irene , Gorwa Joanna , Michnik Robert , Nowakowska-Lipiec Katarzyna , Gómez-Lozano Sebastián , Forczek-Karkosz Wanda
Published: November 2021

Footwork is one of the basic features of flamenco dancing and is performed in traditional high-heeled shoes. The purpose of this study was to analyse the mechanical profile of flamenco dancing in terms of vertical ground reaction force, and knee joint kinematics of the supporting limb in footwork technique in order to understand causes which predispose injuries derived from the practice of flamenco dancing. The participant in our study was a professional female flamenco dancer (34 years, 58 kg, 1.65 m) who performed the ZAP 3 test, a sequence of single strikes of the feet performed continuously for 15 s. 3D lower extremity kinematic data were collected using a five-camera motion analysis system (Vicon; Oxford Metrics Ltd., Oxford, UK). Ground reaction forces were recorded using a Kistler force plate. Our analysis was based on 30 cycles of each lower limb consisting of 177 footwork steps. The vertical component of the ground reaction force did not reveal any significant differences between the left and the right limb. The most dynamic strike was provided by the heel (twice the participant's body weight). The mean angular displacement of the supporting limb’s knee was ~27°. Results reveal that these impacts could make the knee joint more prone to injuries.
Training vs. Competition in Sport: State Anxiety and Response of Stress Hormones in Young Swimmers
Authors: Carrasco Páez Luis , Martínez-Díaz Inmaculada
Published: November 2021

This study was aimed to assess the neuroendocrine response to stress induced by different sports environments (a regular training session and a competitive event), to define the contribution of psychological and physical stress, and to check the possible relationship between state-anxiety and stress hormones responses to competitive and non-competitive sports practices. Twelve young national-level male swimmers participated in this investigation. Endorphins, adrenocorticotropin, and prolactin plasma levels were measured at baseline conditions (t0), before a regular swimming training session (t1), and before and after real swimming competition consisting of 100 m freestyle (t2 and t3, respectively). Moreover, state-anxiety was evaluated in all assessment time-points. The results showed no differences in endorphin, adrenocorticotropin, prolactin and state-anxiety between t0 and t1; however, significant increases in endorphins (142%), prolactin (137%) and state-anxiety (13%) were observed in t2. Huge stress response was observed in t3 (increases of 354%, 387%, and 250% for endorphins, adrenocorticotropin, and prolactin, respectively) although state-anxiety decreased slightly. Lastly, a lack of the relationship between stress hormones and state-anxiety was found in all conditions. Mental and especially physical stress associated with sports competition induces a significant release of stress hormones which is not relevant for the regular training session.
Pacing and Body Weight Changes During a Mountain Ultramarathon: Sex Differences and Performance
Authors: Martínez-Navarro Ignacio , Montoya-Vieco Antonio , Collado Eladio , Hernando Barbara , Hernando Carlos
Published: November 2021

The study was aimed at comparing pacing adopted by males and females in a 107-km mountain ultramarathon and assessing whether pacing-related variables were associated with intracompetition body weight changes and performance. Forty-seven athletes (29 males; 18 females) were submitted to a cardiopulmonary exercise test before the race. Athletes were also weighted before the start of the race, at three midpoints (33 km, 66 km and 84 km) and after the race. Pacing was analyzed using absolute and relative speeds and accelerometry-derived sedentary time spent during the race. Results showed that females spent less sedentary time (4.72 ± 2.91 vs. 2.62 ± 2.14%; p = 0.035; d = 0.83) and displayed a smaller body weight loss (3.01 ± 1.96 vs. 4.37 ± 1.77%; p = 0.048; d = 0.77) than males. No significant sex differences were revealed for speed variability, absolute and relative speed. In addition, finishing time was correlated with: speed variability (r = 0.45; p = 0.010), index of pacing (r = -0.63; p < 0.001) and sedentary time (r = 0.64; p < 0.001). Meanwhile, intracompetition body weight changes were related with both the absolute and relative speed in the first and the last race section. These results suggest that females, as compared with males, take advantage of shorter time breaks at aid stations. Moreover, performing a more even pacing pattern may be positively associated with performance in mountain ultramarathons. Finally, intracompetition body weight changes in those races should be considered in conjunction with running speed fluctuations.
Antioxidants Markers of Professional Soccer Players During the Season and their Relationship with Competitive Performance
Authors: Ponce-Gonzalez Jesus , Corral-Pérez Juan , Villarreal Eduardo , Gutierrez-Manzanedo Jose , Castro-Maqueda Guillermo , Casals Cristina
Published: November 2021

The aim of this study was to assess antioxidant markers before and after a mid-season of professional soccer players from the 3rd Spanish Division, and to correlate antioxidant markers with competitive performance. Sixty-five male players (age = 25.3 ± 4.2 yr, body mass = 73.2 ± 6.7 kg, body height = 177.8 ± 5.7 cm) from three soccer clubs from Cádiz (Spain) participated in the study. Body composition, maximal aerobic capacity (VO2max), and baseline antioxidant blood markers (Total Antioxidant Status (TAS) and Reduced glutathione/Oxidized glutathione ratio) were assessed in the first week of the championship season (pre-test) and after 18 weeks in the mid-season (post-test). Soccer performance was registered according to the official classification ranking at both the mid-season and at the end of the season; ranking positions for Team A were 2nd and 1st, for Team B were 5th and 5th, while for Team C were 12th and 14th, respectively. Regression analyses showed that TAS and VO2max were able to independently predict (p < 0.05) performance in our participants. Moreover, antioxidant levels showed significant main effects on performance (p < 0.001); where a higher antioxidant capacity was observed in the best performance soccer team, both before and after the mid-season. Notwithstanding, the competitive period compromised the antioxidant status since TAS levels significantly decreased after the 18-week training program and competition compared with baseline values in all soccer teams (p < 0.001). These results suggest the need of monitoring antioxidants in soccer players to prevent excessive oxidative stress and cellular damage which could compromise success in competition, by adjusting the training loads, diet or ergogenic aids, if needed.
Age and Maturity Effects on Morphological and Physical Performance Measures of Adolescent Judo Athletes
Authors: Giudicelli Bruno , Luz Leonardo , Santos Douglas , Sarmento Hugo , Massart Alain , Júnior Arnaldo , Field Adam , Figueiredo António
Published: November 2021

Studies assessing age and maturation effects on morphological and physical performance measures of young judokas are scarce. This study aimed to assess the independent and combined effects of chronological age and biological maturation on anthropometry and physical performance of 67 judokas aged 11-14. Participants’ anthropometric profiles were assessed, and physical performance tests were completed. Multivariate analyses of variance revealed an independent effect of age (anthropometry: F = 1.871; p < 0.05; Pillai’s trace = 0.545; η2p = 0.272; physical performance: F = 2.876; p < 0.01; Pillai’s trace = 0.509; η2p = 0.254) and maturity (anthropometry: F = 10.085; p < 0.01; Pillai’s trace = 0.669; η2p = 0.669; physical performance: F = 11.700; p < 0.01; Pillai’s trace = 0.581; η2p = 0.581). There was no significant combined effect of age and maturity. The maturation effect remained significant when controlled for age (anthropometry: F = 4.097; p < 0.01; Pillai’s trace = 0.481; η2p = 0.481; physical performance: F = 3.859; p < 0.01; Pillai’s trace = 0.0.318; η2p = 0.318). Inadolescent judokas, the maturation effect on growth and physical performance seems to be more relevant than the age effect, leading to the need to control this effect in training routines and competitive events. As in studies with youth soccer players and other youth athletes, bio-banding can be a strategy for controlling maturation in combat sports.
Relevance of a Sprint Interval Swim Training Set to the 100‐Meter Freestyle Event Based on Blood Lactate and Kinematic Variables
Authors: Terzi Elissavet , Skari Ariadni , Nikolaidis Stefanos , Papadimitriou Konstantinos , Kabasakalis Athanasios , Mougios Vassilis
Published: November 2021

Sprint interval training (SIT) sets are commonly used by coaches in the training routine of swimmers competing in short-distance events; however, data regarding their relevance to competitive events are scarce. The aim of this study was to examine whether performance variables differed or correlated between a 4 × 50-m maximal swimming set (with a work-to-rest ratio of 1:4) and the 100-m freestyle event. Eleven male and 16 female competitive swimmers aged 16.1 ± 1.1 years participated in the study. All swimmers trained at least six times a week and had training experience of more than 4 years. They completed the two freestyle tests on different days, in random and counterbalanced order. In each test, speed, blood lactate, stroke rate (SR), and stroke index (SI) were measured. Speed, blood lactate, and SR were higher at the 4 × 50 m compared to the 100 m and were positively correlated between tests (p < 0.001). The SI did not differ significantly, but was positively correlated between tests. Males were faster and had a higher SI than females, but genders did not differ in lactate. Since performance variables were better in the SIT set and correlated with those in the 100-m bout, we suggest that the 4 × 50-m set can be used to improve performance in the 100-m freestyle event. Moreover, this set can help coaches identify which swimmers will swim fastest in the event.
The Dirty League: English Premier League Provides Higher Incentives for Fouling as Compared to other European Soccer Leagues
Authors: Phatak Ashwin , Rein Robert , Memmert Daniel
Published: November 2021

Fouling in soccer has been studied from an ethical standpoint as a measure of aggression. However, there is limited research related to fouling for performance. The present study investigated fouling as a factor influencing performance in European soccer leagues. Out of possession fouls (FPGNorm), yellow cards (YCFNorm), and their ratio (YCPFPG) were used as predictors of points (Pts) and goals conceded (GA) at the end of the season using three separate linear regression models. Furthermore, 5-fold cross-validation was used to measure out sample reliability. All the models significantly predicted GA and Pts (p < 0.001). Models predicting GA showed higher reliability than models predicting points. Cross validation (CV) results suggested that FPGNorm and YCPFPG models showed a small standard deviation (SD) in the R2 results whereas the results from YCFNorm were not reliable to high SD in the 5-fold CV results. In summary, FPGNorm and YCPFPG seem to predict success (low GA and high Pts) across European soccer leagues, with EPL showing the maximum effect. The findings of the current study and the methodology can be applied to an actual game analysis by coaches in multiple invasion sports. Normalizing for out of possession time is a crucial step for the time spent in particular phases of play, which has not been done in previous research while analyzing ‘key performance indices’ (KPIs). Normalization can successfully introduce domain-specific knowledge into predictors, which can be used in complex algorithms improving predictions and investigation of underlying mechanisms.
A Mathematical Model for the Take-Off in Platform Diving
Authors: Noth Niklas , Köthe Thomas
Published: November 2021

In platform diving the take-off phase is of outstanding importance in order to achieve both a high level of performing quality and a high degree of difficulty. The diver has to produce the right forces and direction of the center of mass (COM) in order to attain the required angular momentum and dive height. To support the development of an optimum take-off technique, the Institute for Applied Training Science designed a dryland measuring and feedback system. Using the example of the dive back 1¼ somersault tucked in preparation for the dive back 3½ somersault tucked (207 C) from the 10-m-platform, kinematic and kinetic reference values for key positions were determined. Therefore, we developed a mathematical model using a multi-step examination plan with the following parts: (1) variables defined using nonparametric correlation analyses rs of the motion parameters, (2) statistical modelling to predict values of the parameters, (3) stochastic modelling. The model is based on a selection of 18 dives from 10 different elite divers of the German Swimming Federation (DSV). The approach presented provides helpful insights into the mechanisms of an optimal take-off, enables a target-performance comparison with objective motion parameters and therefore, enables individualized feedback to guide the training process more efficiently.
GALNTL6 rs558129: A Novel Polymorphism for Swimming Performance?
Authors: Zmijewski Piotr , Trybek Grzegorz , Czarny Wojciech , Leońska-Duniec Agata
Published: November 2021

The enzyme polypeptide N-acetylgalactosaminyltransferase like 6, encoded by the GALANTL6 gene, plays a role in the gut microbiome regarding regulation of short-chain fatty acids and their anti-inflammatory and resynthesis functions. It was hypothesized that the T allele of the GALNTL6 rs558129 polymorphism could have a positive effect on anaerobic metabolism. Thus, this study was performed to investigate the association between GALNTL6 rs558129 polymorphism and athletic performance in swimmers. A total of 147 Polish short distance (SDS) and 49 long distance swimmers (LDS) of national or international competitive levels and 379 controls were genotyped using the real-time polymerase chain reaction (real-time PCR). We found that the carriers of the T allele (CT+TT) had a 1.56 times higher chance of being SDS (odds ratio (OR): 95%CI 1.06-2.29) than the CC homozygotes. The T allele was overrepresented in the SDS compared with controls (33.7% vs. 25.7%, p = 0.025, OR 1.40, 95% CI 1.04-1.87), but no statistically significant differences were found for LDS. This study provides evidence for an association between the GALNTL6 rs558129 polymorphism and short distance swimming athlete status. Although more replication studies are needed, the preliminary data suggest an opportunity to use the analysis of GALNTL6 polymorphism along with other variants of candidate genes and standard phenotypic assessment in power-oriented sports selection.
The Relationship Between Speed and Strength in the Beach Volleyball Serve
Authors: Terol-Sanchis Mario , Elvira-Aranda Carlos , Gomis-Gomis María , Pérez-Turpin José
Published: November 2021

The objective of this study was to analyze the relationship between isometric force produced in different joints and its effects on the power kick serve speed in beach volleyball as a predictive aspect to improve sports performance. Seven athletes competing at national and international levels (mean ± standard deviation; age: 21.6 ± 3.20 years; body height: 1.87 ± 0.08 cm; body mass 80.18 ± 7.11 kg) were evaluated using maximum isometric force contractions (i.e., spinal and knee extension, grip by a hand dynamometer (handgrip), internal shoulder rotation, shoulder flexion, elbow flexion and extension, and wrist flexion). Speed of the ball was recorded with a pistol radar and force was measured with a strain gauge. Results showed a relationship between isometric force developed in the internal rotation of the shoulder and speed of the ball (r = 0.76*; p < 0.05). In the remaining isometric exercises, positive low to moderate correlations were found in the spine and knee extension (r = 0.56; p = 0.200) and elbow flexion (r = 0.41; p = 0.375). On the other hand, the remaining isometric exercises obtained weak or non-significant correlations. Force developed in the internal rotation of the shoulder highly correlated with the speed of the power kick, explaining, together with the elbow flexion and the extension of the knee and back, much of the variability of the power kick of beach volleyball athletes.
Vertical Jumping as a Monitoring Tool in Endurance Runners: A Brief Review
Authors: García-Pinillos Felipe , Ramírez-Campillo Rodrigo , Boullosa Daniel , Jiménez-Reyes Pedro , Latorre-Román Pedro
Published: November 2021

Jumping performance (e.g., countermovement jump [CMJ]), as a measure of neuromuscular performance, has been suggested as an easy-to-use tool which simultaneously provides neuromuscular and metabolic information and, thereby, allows coaches to confidently monitor the status of their athletes during a workout. This hypothesis has been satisfactorily tested with sprint athletes. However, the rationale for the use of CMJ height loss as an index to monitor the workload during an endurance running session is not sufficiently evidence-based. First, it is assumed that a CMJ height loss occurs during typical interval training for endurance runners. Second, it is also assumed that a significant relationship between metabolic stress and the neuromuscular strain induced during these endurance workouts exists. These two assumptions will be questioned in this review by critically analyzing the kinetics of CMJ performance during and after running workouts, and the relationship between neuromuscular and physiological stress induced during different protocols in endurance runners. The current evidence shows that fatigue induced by common running workouts for endurance runners does not counterbalance the potentiation effect in the CMJ height. Additionally, the findings reported among different studies are consistent regarding the lack of association between CMJ height loss and physiological stress during interval sessions in endurance runners. In practical terms, the authors suggest that this marker of neuromuscular fatigue may not be used to regulate the external training load during running workouts in endurance runners. Nevertheless, the analysis of CMJ height during running workouts may serve to monitor chronic adaptations to training in endurance runners.
Effects of Intensity Modulated Total-Body Circuit Training Combined with Soccer Training on Physical Fitness in Prepubertal Boys After a 6-Month Intervention
Authors: Boraczyński Michał , Boraczyński Tomasz , Gajewski Jan , Kamelska-Sadowska Anna , Gronek Piotr , Laskin James
Published: November 2021

The purpose of this study was to examine the effects of a 6-month high- or moderate-intensity total-body circuit training (CT) program on physical fitness in prepubertal soccer players. Sixty-seven prepubertal boys with a mean age of 11.2 ± 0.7 years completed the study. Participants from a soccer academy were randomly assigned either to a high-intensity CT group (HCT, n = 22) or a moderate-intensity CT group (MCT, n = 24). A control group (CON, n = 21) comprised age-matched individuals who were not involved in any regular training regime. CT protocols were included in the experimental group’s training sessions 3 times per week over 24 weeks as part of their usual weekly training regime. Based on the HR zone method, CT protocols included high- or moderate-intensity (85–95% HRmax or 75–85% HRmax) series of 3 different sets of upper- and lower-body strength exercises with articular and muscular mobilization, all culminated with 40-m sprints. Physical fitness was evaluated by the Eurofit test which included the flamingo balance (FLB), plate tapping (PLT), sit-and-reach (SAR), standing broad jump (SBJ), handgrip (HG), sit-ups (SUP), bent arm hang (BAH), 10×5 m shuttle run (SHR), and the Physical Working Capacity test (PWC170). The two-way ANOVA indicated group×time interaction effects for 5 components: the largest was for the SBJ (F2,63 = 42.895, p < 0.001, η2 = 0.577), and the lowest for the SHR (F2,63 = 5.006, p < 0.01, η2 = 0.137) indicating better improvements in the HCT compared to the MCT group. Furthermore, for HCT and MCT groups the highest pre- to post-intervention percentage changes were for the FLB and the SAR, while in the CON group the changes of all physical fitness components were not significant (p < 0.05). In conclusion, the intensity-controlled total-body CT protocol incorporated into a standard soccer training program is effective for enhancement in physical fitness performance in prepubertal soccer players.