The effects of plyometric jump training on lower-limb stiffness in healthy individuals:A meta-analytical comparison

Purpose:This study aimed to examine the effects of plyometric jump training(PJT)on lower-limb stiffness.Methods:Systematic searches were conducted in PubMed,Web of Science,and Scopus.Study participants included healthy males and females who undertook a PJT programme isolated from any other training type.Results:There was a small effect size(ES)of PJT on lower-limb stiffness(ES=0.33,95%confidence interval(95%CI):0.07-0.60,z=2.47,p=0.01).Untrained individuals exhibited a larger ES(ES=0.46,95%CI:0.08-0.84,p=0.02)than trained individuals(ES=0.15,95%CI:-0.23 to 0.53,p=0.45).Interventions lasting a greater number of weeks(>7 weeks)had a larger ES(ES=0.47,95%CI:0.06-0.88,p=0.03)than those lasting fewer weeks(ES=0.22,95%CI:-0.12 to 0.55,p=0.20).Programmes with<2 sessions per week exhibited a larger ES(ES=0.39,95%CI:0.01-0.77,p=0.04)than programmes that incorporated>2 sessions per week(ES=0.20,95%CI:-0.10 to 0.50,p=0.18).Programmes with<250 jumps per week(ES=0.50,95%CI:0.02-0.97,p=0.04)showed a larger effect than programmes with250-500 jumps per week(ES=0.36,95%CI:0.00-0.72,p=0.05).Programmes with>500 jumps per week had negative effects(ES=-0.22,95%CI:-1.10 to 0.67,p=0.63).Programmes with>7.5 jumps per set showed larger effect sizes(ES=0.55,95%CI:0.02-1.08,p=0.04)than those with<7.5 jumps per set(ES=0.32,95%CI:0.01-0.62,p=0.04).Conclusion:PJT enhances lower-body stiffness,which can be optimised with lower volumes(<250 jumps per week)over a relatively long period of time(>7 weeks).

Effects of Physical Exercise and Music Therapy on Cognitive Aspects in Tunisian Patients with Mild Alzheimer’s Type Dementia

Aim: The objective of this research is to highlight the effectiveness of physical exercise and music therapy in older patients with Alzheimer’s disease (AD). Methods: Patients with a mild level of AD were included in this study, divided into the therapy group (TG;N = 30, aged 68 ± 3.2 years) and the control group (CG;N=30, aged 65 ± 2.6 years). The therapy group was enrolled in an exercise-training program (walking, resistance and balance exercises) combined with musical therapy for 10 weeks (three sessions of 60 minutes per week). The Control group was instructed to follow their daily rhythm of life (e.g., rest, reading) under the same conditions. The intervention program was enrolled under the supervision of;one psychologist;a neurologist;two music therapists, and two physiotherapists, all belonging to the same hospital unit. After 10 weeks of participation in the combined program, cognitive parameters were improved in the therapy group measured with the Behavior Pathology in Alzheimer Disease (BEHAVE-AD), (p < 0.05) for activity disturbance, diurnal rhythm disturbances, anxieties and phobias, affective disturbance. The percentage range of improvements is 1.07% to 2.96%. Results: Our results demonstrate that physical exercise combined with music therapy improves cognitive function in patients with Alzheimer’s disease. Conclusions: Physical exercise and music therapy are beneficial combined treatments for improving life quality in older patients. This approach may be useful to help patients with a mild level of Alzheimer’s disease improve their behavioral and psychological parameters.

The effects of plyometric jump training on physical fitness attributes in basketball players:A meta-analysis`

Background:There is a growing body of experimental evidence examining the effects of plyometric jump training(PJT)on physical fitness attributes in basketball players;however,this evidence has not yet been comprehensively and systematically aggregated.Therefore,our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players,in comparison to a control condition.Methods:A systematic literature search was conducted in the databases PubMed,Web of Science,and Scopus,up to July 2020.Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes(muscle power,i.e.,jumping performance,linear sprint speed,change-of-direction speed,balance,and muscle strength)in basketball players,with no restrictions on their playing level,sex,or age.Hedge’s g effect sizes(ES)were calculated for physical fitness variables.Using a random-effects model,potential sources of heterogeneity were selected,including subgroup analyses(age,sex,body mass,and height)and single training factor analysis(program duration,training frequency,and total number of training sessions).Computation of metaregression was also performed.Results:Thirty-two studies were included,involving 818 total basketball players.Significant(p<0.05)small-to-large effects of PJT were evident on vertical jump power(ES=0.45),countermovement jump height with(ES=1.24)and without arm swing(ES=0.88),squat jump height(ES=0.80),drop jump height(ES=0.53),horizontal jump distance(ES=0.65),linear sprint time across distances≤10 m(ES=1.67)and>10 m(ES=0.92),change-of-direction performance time across distances≤40 m(ES=1.15)and>40 m(ES=1.02),dynamic(ES=1.16)and static balance(ES=1.48),and maximal strength(ES=0.57).The meta-regression revealed that training duration,training frequency,and total number of sessions completed did not predict the effects of PJT on physical fitness attributes.Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance(>17.15 years,ES=2.11;≤17.15 years,ES=0.10;p<0.001),linear sprint time>10 m(>16.3 years,ES=1.83;≤16.3 years,ES=0.36;p=0.010),and change-of-direction performance time≤40 m(>16.3 years,ES=1.65;≤16.3 years,ES=0.75;p=0.005).Greater increases in horizontal jump distance were apparent with>2 compared with≤2 weekly PJT sessions(ES=2.12 and ES=0.39,respectively;p<0.001).Conclusion:Data from 32 studies(28 of which demonstrate moderate-to-high methodological quality)indicate PJT improves muscle power,linear sprint speed,change-of-direction speed,balance,and muscle strength in basketball players independent of sex,age,or PJT program variables.However,the beneficial effects of PJT as measured by horizontal jump distance,linear sprint time>10 m,and change-of-direction performance time≤40 m,appear to be more evident among older basketball players.

Effects of 12 weeks of back-squat training program on jump performances and bone markers in female students

Background:The training program promoted improvements of jump abilities throughout the musculoskeletal system including bone markers.The aim of this study is to examine both the acute and chronic response of bone markers to resistance training program.Methods:Ten female students(age:18±0.7 years,body mass:63±3.6 kg;height:164±5.2 cm)participated in this study.They were recruited for a back-squat training program for 12 weeks,two days/week.The full-back squat protocol consisted of 3–5 sets×3–8 repetitions at 45–55%one repetition maximum.Testing sessions included a 5 jump test(5JT),standing long jump(SLJ),drop jump(DJ),and vertical jump(VJ).Results:Substantial improvements in all testing jumps(5JT:∆10%;P=0.000;ES=1.72;SLJ:∆7%;P=0.000;ES=1.33;DJ:∆11%;P=0.000;ES=0.72;VJ:∆20%;P=0.000;ES=1.84)were found during post program in comparison to pre-program results.Moreover,a significant change(P≤0.05)of bone markers during post-exercise compared to pre-exercise either before or after the training program.Only collagen type I carboxy-terminal peptide(CICP)levels elevated after the training program(pre-exercise only)compared to former levels.Conclusion:12 weeks of back-squat training program resulted greater acute improvements of jump abilities with adaptation in all musculoskeletal system including bone formation.

Small ruminant value chain in Al-Ruwaished District,Jordan

This study aims to assess the small ruminant value chain in Al-Ruwaished District,Jordan,to identify the potential intervention areas that could improve the production efficiency and guarantee the sustainability of the small ruminant sector in this area.Sheep breeding is the source of livelihood for most of the people in Al-Ruwaished District,which is characterized by the large number of sheep and goats.We surveyed 5.0% of the small ruminant holders in the study area and conducted individual interviews and surveys with the potential actors in the value chain to undertake a small ruminant value chain analysis.From the survey,we found that the small ruminant value chain consists of five core functions,namely,input supply,production management,marketing,processing,and consumption.Despite the stable impression given by the large number of holdings in the small ruminant sector,the surveyed results show a clear fragility in the value chain of small ruminants in this area.The small ruminant production system is negatively impacted by climate change,especially continuous drought.In addition,the high prices of feed that the farmer cannot afford with clear and real absence of the governmental and non-governmental support activities also impact the development of the value chain.The results of strengths,weaknesses,opportunities,and threats(SWOT)analysis reveal that the major constraints faced by this value chain could be divided into external and internal threats.Specifically,the most prominent external threats are the nature of the desert land and continuous drought,while the major internal threats are the absence of appropriate infrastructure,shortage of inputs,and weakness in the production management and marketing.We proposed solutions to these challenges to ensure the sustainability and effectiveness of the sector,such as the formulation of emergency response plans to severe weather,qualifying farmers’skills,and establishment of agricultural cooperative societies.

Diversification, bank performance and risk:have Tunisian banks adopted the new business model?

Background:The objective of this paper is threefold.First,we test the most important factors that determine the level of non-interest income for Tunisian banks.Second,we study the impact of non-interest income on banks’profitability measured by both return on assets(ROA)and return on equity(ROE).Finally,we investigate the relationship between non-interest income and the level of risk taking.Methods:To achieve this goal,we used annual data of 20 Tunisian banks during the period 2005-2012.In the empirical section we performed a Dynamic Panel Data model.Results:Empirical results indicate that the main determinants of non-interest income are:relative performance(RROA and RROE),bank size,loan specialization and new epayments channels,automatic teller machine(ATM)and credit cards.We also find that diversification increases bank performance for both ROA and ROE measures.Eventually,non-interest income appears to be negatively and significantly correlated with the effect on the level of risk.Conclusions:Tunisian banks are invited to more diversify their activities and do not focus only on the traditional activity.The noninterest income seems to be associated with a higher level of profitability and a lower risk.

Testing the governance-performance relationship for the Tunisian banks: a GMM in system analysis

Rationale:This study aims to contribute to settling the lack of consensus regarding the determinants of bank performance,not only by considering bank governance,but also by including factors such as CEO compensation and risk management committee.Previous literature has included bank governance and considered only large banks in their surveys.The exclusion of other factors such as small-and medium-size banks may render the findings of these studies limited in applicability.Objective:The objective of this paper is to examine the impact of internal governance on bank performance.Methodology:To achieve this goal,we used annual data of a sample of ten Tunisian commercial banks listed in the Tunisian Stock Exchange observed during the period 1998–2015.We use the Generalized Method of Moments(GMM)to estimate the parameters of our econometric model.Results:Our study finds that the correlation between the size of the board of directors,the state’s inclusion,and the presence of independent directors is positive and significant.On the other hand,we have found that CEO compensation,as well as foreign and institutional investors negatively affect the performance of the banks.Conclusions and implications:Tunisian banks are invited to broaden their size through appropriate restructuring,adopt new remuneration policies and define the optimal number of directors representing the state within the board of directors.Our results suggest managerial implications that can be of great value to ensuring the success of Tunisian banks.The latter should favor a higher presence of independent directors to reduce the bank control ineffectiveness caused by having a significant number of foreign and institutional investors in the board of directors.

Nitrogen and Organic Matter Mineralization in the Tunisian Cork Oak Forest: A Laboratory Study

The mineralization of the organic matter is a very important phenomenon which leads to the release of nutriments used by plants. The rate of transformation of the organic matter depends on several factors and parameters such as climatic factors and biological and physicochemical properties of the soil and the litter. In this study, we investigate the effect of the addition of litter of various species as well as the effect of soil moisture on mineralization of organic matter and on mineral nitrogen release in three soils sampled in three cork oak stands during a period of 41 days under the same laboratory conditions. Carbon mineralization was determined using CO2 respiration method, whereas the mineral nitrogen content was measured at the last day of incubation both in soil samples with added plant leaf material, and in control soil samples without addition under two treatments of moisture (40% and 80% WHC—water holding capacity). Our results show that the addition of leaf litter causes an increase in the microbial activity. Soils without addition were significantly different from the plant leaf added soils in respect to carbon mineralization at the end of the incubation period. Moreover, it is noted that the mineralization of carbon is more marked with moisture at 80% than that of 40%, contrary to that of the nitrogen, which is not influenced by the variation of moisture.

A Bio-Hydraulic Modelling Approach to Control the Hemodialysis Patient Status—Calculus and Validation

We have developed a model permitting the control of the hemodialysis patient status. We have represented the functioning of each body compartment by a set of differential equations that express the mass balance of the carbonate and bicarbonate concentrations in each one. Experimental data from bibliography were analyzed and compared to our calculus. Results were well satisfying.

A Hybrid Particle Swarm Optimization to Forecast Implied Volatility Risk

The application of optimization methods to prediction issues is a continually exploring field.In line with this,this paper investigates the connectedness between the infected cases of COVID-19 and US fear index from a forecasting perspective.The complex characteristics of implied volatility risk index such as non-linearity structure,time-varying and nonstationarity motivate us to apply a nonlinear polynomial Hammerstein model with known structure and unknown parameters.We use the Hybrid Particle Swarm Optimization(HPSO)tool to identify the model parameters of nonlinear polynomial Hammerstein model.Findings indicate that,following a nonlinear polynomial behaviour cascaded to an autoregressive with exogenous input(ARX)behaviour,the fear index in US financial market is significantly affected by COVID-19-infected cases in the US,COVID-19-infected cases in the world and COVID-19-infected cases in China,respectively.Statistical performance indicators provided by the developed models show that COVID-19-infected cases in the US are particularly powerful in predicting the Cboe volatility index compared to COVID-19-infected cases in the world and China(MAPE(2.1013%);R2(91.78%)and RMSE(0.6363 percentage points)).The proposed approaches have also shown good convergence characteristics and accurate fits of the data.

Quantum correlations and optical effects in a quantum-well cavity with a second-order nonlinearity

In this paper,we investigate the photon correlations and the statistical properties of light produced by an optical cavity with an embedded quantum well interacting with squeezed light.We show that the squeezed source substantially improves the intensity of the emitted light and generates a narrowing and a duplication of the spectrum peaks.With a strong dependence on frequency detuning,the cavity produces considerably squeezed radiation,and perfect squeezing is predicted for weak light–matter interactions.Furthermore,the system under consideration presents a bunching effect of the transmitted radiation resulting from weak pumping of the coherent field.The results obtained may have potential applications in the fields of very accurate measurement and quantum computing.

Investigating Plasma Jets Behavior using Axisymmetric Lattice Boltzmann Model under Temperature Dependent Viscosity

This study aims to investigate turbulent plasma flow using the lattice Boltzmann(LB)method.A double population model D2Q9-D2Q4 is employed to calculate the plasma velocity and temperature fields.Along with the calculation process a conversion procedure is made between the LB and the physical unit systems,so that thermo-physical properties variation is fully accounted for and the convergence is checked in physical space.The configuration domain and the boundary condition treatment are selected based on the most cited studies in order to illustrate a realistic situation.The jet morphology analysis gives credible results by comparison with commonly published works.It was demonstrated also that accounting for the substrate as wall boundary condition modify greatly the flow and temperature structures with may affect absolutely the particles behavior during its in-flight in the hot gas.