Controlling Variables Research Articles

T167. Measures of Activity- and Energy-Related Gait Variables as Behavioral Biomarkers of Bipolar Disorder: A 6-Month Longitudinal Study

Quantitative information about the association between mood symptoms and motor behavior in bipolar patients (BP) is very limited. We investigated activity- and energy-related gait variables in BP and healthy controls (HC) at baseline and 6-month follow-up sessions.

Effects of Heated versus Thermoneutral Bikram Yoga Interventions on Endothelial Function and Arterial Stiffness

Bikram (hot) yoga is a style of hatha yoga practiced at 40.5° C with 40–60% relative humidity. We have previously documented improvements in endothelium‐dependent vasodilation but not arterial stiffness in healthy, middle‐aged adults with an 8‐week Bikram yoga intervention. Currently, it is unknown whether the effect of hot yoga on endothelial function might be attributed to the hatha yoga asanas or the high temperature/humidity. It is also unknown whether a longer intervention might produce significant alterations in arterial stiffness.PURPOSEThe purpose of this investigation was to determine the effects of a 12‐week Bikram yoga intervention performed in standard heated conditions and in a thermoneutral environment on endothelium‐dependent vasodilation and arterial stiffness.METHODSFifty‐two sedentary but apparently healthy adults aged 40–60 years were randomly assigned to one of three groups: Bikram yoga practiced at 40.5°C (n=19); Bikram yoga practiced at 23°C (n=14); or sedentary time‐control (n=19). The 12‐week yoga intervention consisted of 3 weekly 90‐minute Bikram yoga classes. The time control group was instructed to maintain current lifestyle patterns for the study duration. Body composition was determined via dual energy x‐ray absorptiometry (DXA). Endothelium‐dependent vasodilation was measured noninvasively using brachial artery flow‐mediated dilation (FMD) after 5 minutes of blood flow occlusion. Arterial stiffness was measured via brachial‐ankle pulse wave velocity (PWV).RESULTSAge, anthropometric variables, plasma lipid, glucose, and triglyceride concentrations, brachial artery FMD and brachial‐ankle PWV were not different among the three groups at baseline. Body fat percentage declined (p<0.01) and total‐ (p=0.051) and LDL‐cholesterol (p =0.09) concentrations tended to decline only in the hot (40.5°C) yoga group. Brachial artery FMD increased (P<0.05) in both yoga groups but brachial‐ankle PWV was not significantly altered in any group. There were no changes in any outcome variables in the time control group.CONCLUSIONSBikram yoga practiced in hot/humid and thermoneutral conditions produced similar improvements in endothelium‐dependent vasodilation in healthy, middle‐aged adults. The addition of the heat led to reductions in body fat percentage. Bikram yoga does not appear to modulate arterial stiffness in middle‐aged adults.Support or Funding InformationThis study was funded by Pure Action, Inc. Austin, TX, USAThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Down regulation of human telomerase reverse transcriptase (hTERT) expression by BIBR1532 in human glioblastoma LN18 cells.

Increased telomerase activity can be blocked by targeting the hTERT activity at both RNA and catalytic subunits. Various inhibitors had been used to regulate hTERT activity in glioblastoma cell lines and showed promising results. The present study hypothesized that the telomerase specific inhibitor BIBR1532 can effectively down-regulate the telomerase activity in LN18 glioblastoma cell line. LN18 glioblastoma cell line was treated with various concentrations of BIBR1532 at different time intervals. MTT assay was performed to determine cell viability after BIBR1532 treatment. hTERT mRNA and protein expression were determined by qRT-PCR and western blotting, respectively. Flow cytometry and TRAP assay was performed to detect the rate of apoptosis and telomerase activity in treated and control samples. One-way ANOVA was performed to compare the mean values of variables in control and BIBR1532 treated groups. LN18 cells showed a significant dose dependent cytotoxic effect after treatment with BIBR1532. hTERT mRNA expression in cells treated with 25, 100 and 200μM BIBR1532 treated groups was decreased ~21, ~61.2, and ~77%, respectively (p<0.05). We also observed that, BIBR1532 treatment reduced the expression of hTERT protein in LN18 cells in a dose dependent manner. The Flow cytometry data showed that, the drug induced significant increase in the total percentage of apoptotic cells with 200μM concentration of BIBR1532 at all time points. BIBR1532 exhibited potent inhibition of telomerase activity in a dose-dependent manner in LN18 cells. BIBR1532 could induce apoptosis in LN18 cells through the downregulation of telomerase activity at transcriptional and translational level. We conclude that BIBR1532 may be a therapeutic agent to suppress telomerase activity, however, further efforts are necessary in order to explore this therapeutic strategy.

Analysis of Institutional Quality Influence on Shadow Economy Development

GDP is the main indicator of economy which reflects economic activities in a country. In fact, shadow economy is exist in every country, it is some of the activities which are not included in the national account. This condition can lead to a biased policies. So that, it is important to take into account the shadow economy when formulating policies. There are no such of data for shadow economy activities. The purpose of this research is to estimate shadow economy in seven developing countries of ASEAN. The estimation method used is the MIMIC approach in the period of 2007-2016. Besides, this research also examines the influence of the institutional quality on the shadow economy development. The results show that shadow economy in ASEAN has increased since 2007. Thailand is a country with the largest shadow economy among the ASEAN member countries with an average of 46.84% of GDP. On the other hand, the institutional quality shows a negative relationship with the development of shadow economy, except regulatory quality. Variables of control of corruption, political stability and absence of violent, and voice and accountability have influence on reducing the shadow economy development.

POSTURAL CONTROL ANALYSIS DURING A STANDARDIZED KICK TASK IN SOCCER ATHLETES

ABSTRACT Introduction: Postural control is a determining factor for functional performance and motor skills during sports activities. Objective: The objective of this study was to investigate postural control during the controlled soccer ball kicking task through a biomechanical analysis system. Methods: The sample consisted of 11 professional male athletes recruited using convenience sampling, with a mean age of 22 years. The athletes performed twenty-five precision kicks at a target, with the ball in vertical motion released by means of a hand-held device synchronized with the computed biomechanical measurements. Marking of the lower limb segments involved in the kick and the ball were analyzed by accelerometry, while postural control measures were quantified by a force platform in three axes of movement. The support leg was investigated in single leg stance during all tests on the force platform. The main variables of postural control calculated by stabilographic analysis and computed during the 25 kicks were: center of pressure (COP) displacement area, velocity and frequency of COP oscillation in the anteroposterior and mediolateral directions. The mean was used for final analysis to determine the differences in the three phases: pre-kick, kick, and post-kick. Results: The results revealed significant differences (p &lt;0.01) between the three phases, with the kick phase presenting higher values of postural COP oscillations than the other phases. The COP area and oscillation velocity were the variables with greatest sensitivity to changes in the kick phase, obtaining an effect size of d = 14 and d = 12, respectively. In clinical terms, the increase in COP values reached 557% between the pre-kick and kick phases; this difference was reduced to 241% when compared to post-kick (i.e., difference between kick and post-kick was 316%). Conclusion . These results have important implications for the perception of postural control responses during soccer ball kicks and consequently, for injury prevention when motor and sensory deficits are diagnosed in soccer players. Level of Evidence III; Study of nonconsecutive patients; without consistently applied reference ‘‘gold’’ standard.

Feedforward-feedback control of a solid oxide fuel cell power system

One of the main challenges for wide-spread utilization of the solid oxide fuel cell (SOFC) power systems is how to achieve high electrical efficiency without increasing the degradation rate of the fuel cells. To run the SOFC power system at high efficiency over a long period of time, properly designed controllers are indispensable.Although a number of various approaches to control SOFC have been proposed so far, it seems that the design of control system, along with simple tuning procedure, has not been treated in a consistent manner. This issue is addressed in the present paper resulting in a feedforward-feedback control structure. The feedforward part is based on the stoichiometry of electro-oxidation, reforming and combustion reactions, which allow immediate response to variable current demand. The feedback part performs additional fine adjustment of fuel and air supply in order to minimize the undesired system temperatures variations. The selection of pairings of manipulated and controlled variables for control is based on physical knowledge of the system. Input/output pairing for single-loop feedback control is assessed by the relative gain analysis. An efficient procedure for tuning the parameters of the feedback controllers is suggested, relying on simple open-loop step responses of the system.The proposed low-level control is assessed on a detailed physical model of a 2.5 kW SOFC power system by simulating two nonstationary load regimes. Simulations show that the control provides a robust operation under large load variations while meeting the operating constraints. Due to its simplicity, the control is feasible for implementation on a real SOFC system.

Top-Down Prioritization of Salient Items May Produce the So-Called Stimulus-Driven Capture.

The current study proposes that top-down attentional prioritization of salient items may produce the so-called stimulus-driven capture. To test this proposal, the “expectation-based paradigm” was designed on the basis of a visual search task. In Experiment 1, a task-irrelevant singleton frame was presented at the same location in 70% of the trials. The target was either presented at chance level within the singleton location, or away from it. In line with the singleton capture phenomenon, participants were faster in identifying the target when it appeared in the singleton location compared to non-singleton locations. However, leaving out the singleton frame in 30% of the trials led to a similar effect; participants were faster in identifying the target when it appeared in the expected singleton location compared to expected non-singletons locations (a “quasi-capture” effect). These results suggest that the participants allocated their attention to the expected singleton location, rather than that the singleton itself captured attention. In Experiment 2, the same task-irrelevant color singleton was presented in a random position in 70% of the trials. This color frame was shown as a non-singleton in all of the 30% singleton-absent multicolored trials. A similar facilitation effect was obtained when the target appeared in the expected singleton color frame compared to other frames, in singleton-absent trials as in singleton-present trials. These results further support the idea that instances of singleton capture can be explained by top-down attentional shifts toward singleton items. Theoretical implications of these results are discussed. Mostly, the study calls to consider the possibility that all sources of attentional control may be represented by a continuous variable of top-down control, including the category of “physical salience.”

Examination of the effects of some variables in internal control and organizational stress management via multiple regression on perception of risk and uncertainty

Internal control is an essential element of successful and effective management. Internal control which plays a role as a proactive and integral element in organizations’ adapting to changing and changes also plays an important role in the realization of organizational strategy. In some cases, change brings risks along with uncertainties. One of the most effective tools against the stress occurring in cases where the risks and change cannot be managed is, without doubt, internal control practices. Risk management practices are dealt with within the scope of internal control. Risk management is directly related to perception of risks and uncertainties of the employees and the organization. The effect of some variables on the perception of risk and uncertainty has been investigated since the risks and uncertainties in the organizations are constantly in interaction with stress and internal control applications. The study was conducted face to face by asking 348 entrepreneurs operating on the textile industry to fill in the survey form in Kayseri in Turkey. The effects of total work experience, age, gender and strength on perception of risk and uncertainty have been determined.

Performance investigations of APSO tuned linear and nonlinear PID controllers for a nonlinear dynamical system

This paper investigates the performance of adaptive particle swarm optimization (APSO) algorithm to find the best optimal gain parameters (Kp, Ki, Kd) in linear PID (L-PID) and nonlinear PID (NL-PID) controllers for the trajectory control of a nonlinear dynamical system (NLDS). Mathematical modeling, stability and performance analysis of a NLDS are being carried out with L-PID and NL-PID controllers. It is found that the APSO based tuning of NL-PID controller provides better tracking of NLDS than L-PID controller in respect of its search domain, premature convergence, and computational efficiency. Simulation analysis of various variables of controllers and system response such as error, cost function, and response of NLDS and their comparison to that of APSO tuned L-PID controller is described.

Comparison of Different Controllers and Stability Analysis for Photovoltaic Powered Buck-Boost DC-DC Converter

In this study, proportional integral (PI), fuzzy logic (FL), and sliding mode (SM) control of DC-DC buck-boost converter are presented. The obtained results were compared for these controller methods. The converter system, which is powered by photovoltaic (PV) modules, was simulated using the MATLAB/Simulink software. The sliding mode controller in which the inductance current and the output voltage are used as controller variables was tested and the results are compared with the results obtained by the fuzzy logic controller and proportional integral controller. The small signal analysis of the DC-DC buck boost converter has been conducted for the stability analysis of the designed system. Bode phase and magnitude diagrams are plotted for different duty ratios. The performance of the converter has been analyzed in detail for different photovoltaic conditions. The converter has been simulated for controllers and PV module using different parameters and the effects have been observed by the results. The converter experimental setup was implemented and the results were repeated. A digital signal processor (DSP) was used for the experimental study for faster processing. The experimental results were found to be compatible with the simulation results.

The prevalence of APOL1 gene variants in a cohort of renal disease patients in Western Saudi Arabia.

Two variants for APOL1; the gastrointestinal (G1) variant (S342G and 1384M substitutions) and the G2 variant (N388 and Y389 deletions) have been previously described to be associated with renal disease. The prevalence of APOL1 variants in Saudi Arabia is unknown. We aimed to determine the prevalence of APOL1 variants in a cohort of patients with renal disease in Saudi Arabia. Patients with renal disease followed up at King Abdulaziz University Hospital were approached consecutively at the out patient clinic, and unaffected controls were approached at the blood donation area. Clinical and laboratory data were collected from electronic medical records. Laboratory variables in controls were obtained on enrollment. This is a cross-sectional, cohort study. One hundred and one patients with a mean age of 54.5 (±19) years, and 119 unaffected controls with a mean age of 31.9 (±7.89) years, were enrolled. Seventy-four patients (68.5%) had hypertension and 62 (57.4%) had diabetes. The mean estimated glomerular filtration rate was 22.47 (± 27.6) mL/min. Two patients were heterozygous for G1 allele. Among the control group, two were heterozygous for G1 allele, and three were heterozygous for G2. All five controls had no evidence of renal disease and no family history of renal disease. The prevalence of APOL1 genetic risk variants in the study cohort was very low. Larger studies are needed to determine the prevalence among renal disease patients in Saudi Arabia.

Effectiveness of self worth therapy on depression among elderly in selected old age homes, Kancheepuram District

In our ageing society, the problem of depression can reach further than the undoubted emotional suffering of elderly individual. The objective was to determine the effectiveness of self worth therapy on depression among elderly in study group. The quantitative approach and quasi experimental-Pretest-post test control group design was used for this study. The study was conducted with 62 samples of elderly with mild depression using purposive sampling technique. The study was conducted at selected old age homes, Kancheepuram District. The data was analyzed and interpreted based on the objectives using descriptive and inferential statistics. Self worth therapy was found to be effective in reducing the level of depression. There is no association between post-test level of depression among elderly with their demographic, personal and clinical variables in study and control group.self worth therapy was highly effective in reducing depression of elderly persons those who were in selected old age homes, Kancheepuram District.

Nutritional status, body image, and their association with extreme weight control behaviors among Brazilian adolescents, National Adolescent Student Health Survey 2015.

This study aimed to analyze the association between nutritional status, body image perception, and extreme weight control behaviors among adolescents. This is an analytical cross-sectional study conducted in Brazil based on the National Adolescent Student Health Survey (Pesquisa Nacional de Saúde do Escolar - PeNSE) of 2015, with adolescents aged 13 to 17 years. Nutritional status and body image perception were the independent variables. The two dependent variables were vomiting or laxative use and use of medicines and other formulas for weight control in the 30 days prior to data collection. We used Poisson regression models for association, with demographic variables for control. 7.4% of adolescents (95%CI 6.7 - 8.2) reported vomiting or using laxatives, with no difference between genders. The prevalence of use of medicines and formulas was higher among boys (7.8%; 95%CI 6.6 - 8.9). The association between nutritional status and extreme behaviors was not significant. However, the prevalence of vomiting or laxative use for adolescents who considered themselves very fat was 2.3 (95%CI 1.1 - 4.7) times higher for boys and 5.3 (95%CI 3.3 - 8.6) times higher for girls, while the use of medicines and formulas was 4.0 (95%CI 2.3 - 7.1) times higher for girls who considered themselves very fat. Body image perception seems to have a greater influence on extreme behaviors than nutritional status. Strategies involving health services and schools have great potential to impact the self-esteem and health of students positively.

Los sobrecostos en los equipos de medición del proceso de pintura de la empresa Renault Sofasa, aplicando la metodología Kaizen

En este artículo se presentan los resultados de la investigación sobre los factores que inciden en el retiro de los equipos de medición del proceso de pintura, de la empresa colombiana ensambladora de vehículos Renault Sofasa. Empleando métodos como el Kaizen y el Sistema de Aseguramiento Metrológico (SAM), se realiza un diagnóstico para determinar la pérdida económica generada por los sobrecostos ocasionados por los equipos de medición en etapas críticas del proceso productivo. Los resultados obtenidos por medio de esta investigación servirán de base para que la compañía desarrolle soluciones pertinentes, utilizando esta información como una herramienta para mitigar los sobrecostos generados en el departamento de producción. Los resultados obtenidos sugieren la importancia de contar con un método adecuado para controlar y mejorar los procesos, no solo en la industria automotriz, sino en todos los sectores económicos que utilicen equipos de medición y que estos se encuentren vinculados con las variables críticas de control y la elaboración de los productos.

How Have Political Incentives for Local Officials Reduced the Environmental Pollution of Resource-depleted Cities?

Chinese resource-exhausted cities face more severe environmental pollution problems than other cities. In addressing these problems, the way local officials, usually senior party and government leaders, operate, is very important, in that their focus on political achievements may complicate how they manage environmental pollution in these cities. Based on this, we analyze the relationship between political incentives and environmental pollution by applying the 2004-2014 panel data from 37 resource-exhausted cities. The findings reveal that: (1) Local openness levels, degree of industrial upgrading and local investment in fixed assets are not the key variables in environmental pollution control. (2) The extent to which officials vie for political achievement affects environmental pollution in resource-exhausted cities. It depends on whether the officials are municipal party secretaries or mayors; the former play a greater dynamic role in environmental pollution and have a stronger robustness than the latter. The conclusion verifies that the selection of municipal party secretaries, rather than mayors, is particularly important in coming to terms with local environmental pollution.

Flortaucipir F 18 Quantitation Using Parametric Estimation of Reference Signal Intensity.

PET imaging of tau pathology in Alzheimer disease may benefit from the use of white matter reference regions. These regions have shown reduced variability compared with conventional cerebellar regions in amyloid imaging. However, they are susceptible to contamination from partial-volume blurring of tracer uptake in the cortex. We present a new technique, PERSI (Parametric Estimation of Reference Signal Intensity), for flortaucipir F 18 count normalization that leverages the advantages of white matter reference regions while mitigating potential partial-volume effects. Methods: Subjects with a clinical diagnosis of Alzheimer disease, mild cognitive impairment, or normal cognition underwent T1-weighted MRI and florbetapir imaging (to determine amyloid [Aβ] status) at screening and flortaucipir F 18 imaging at single or multiple time points. Flortaucipir F 18 images, acquired as 4 × 5 min frames 80 min after a 370-MBq injection, were motion-corrected, averaged, and transformed to Montreal Neurological Institute (MNI) space. The PERSI reference region was calculated for each scan by fitting a bimodal gaussian distribution to the voxel-intensity histogram within an atlas-based white matter region and using the center and width of the lower-intensity peak to identify the voxel intensities to be included. Four conventional reference regions were also evaluated: whole cerebellum, cerebellar gray matter, atlas-based white matter, and subject-specific white matter. SUVr (standardized uptake value ratio) was calculated for a statistically defined neocortical volume of interest. Performance was evaluated with respect to test-retest variability in a phase 2 study of 21 subjects (5-34 d between scans). Baseline variability in controls (SD of SUVr and ΔSUVr) and effect sizes for group differences (Cohen d; Aβ-positive impaired vs. Aβ-negative normal) were evaluated in another phase 2 study with cross-sectional data (n = 215) and longitudinal data (n = 142/215; 18 ± 2 mo between scans). Results: PERSI showed superior test-retest reproducibility (1.84%) and group separation ability (cross-sectional Cohen d = 9.45; longitudinal Cohen d = 2.34) compared with other reference regions. Baseline SUVr variability and ΔSUVr were minimal in Aβ control subjects with no specific flortaucipir F 18 uptake (SUVr, 1.0 ± 0.04; ΔSUVr, 0.0 ± 0.02). Conclusion: PERSI reduced variability while enhancing discrimination between diagnostic cohorts. Such improvements could lead to more accurate disease staging and robust measurements of changes in tau burden over time for the evaluation of putative therapies.

Robustness Analysis of an Optimized Controller via Particle Swarm Algorithm

This paper deals with an evaluation on the effectiveness of the robust controller in terms of its robustness towards the changes in the electro-hydraulic actuator (EHA) system parameters. It is well known that the defects exposed in this system are the existence of disturbances, parameters variation, and uncertainties in nature that yielding great difficulties in the development of system controller and the modelling of EHA system. Such difficulties simultaneously vitiating system performance and imposed if inappropriate control strategy is employed. A nonlinear EHA system model is established and the proposed controller which is sliding mode controller (SMC) is implemented in the simulation studies. The proposed control strategy has been compared with the conventional proportional-integral-derivative (PID) controller concerning its robustness characteristic with the variation in the system supply pressure in which the controller variables are obtained through particle swarm optimization (PSO) algorithm. The finding shows that the SMC that utilized the PSO algorithm parameters are capable to produce smaller robustness index values, which demonstrated better robustness characteristic in confront with the variation of the system parameter.

Off-Balance Items and Their Impact on the Financial Performance Standards of the Banks: An Empirical Study on the Commercial Banks of Jordan

The purpose of this study is to test the effect of off-balance items on the Jordanian commercial banks performance criteria. The test is based on a sample of 13 Jordanian commercial banks listed on the stock exchange of Amman during the period 2009-2016. The depend variables of the study included the financial performance standards represented in of rate of return on assets (ROA) and return on the equity (ROE). The independent variables included the percentage of off-balance items to the total assets, in addition to three controller variables; namely credit facilities, equity ratio and the size of the bank. The results of the study showed that the volume of Jordanian commercial banks off-balance items are high as they constitute more than one-fifth of the total assets. The results of the regression analysis showed that the off-balance items have a positive effect with statisticalsignificance on the rate of return on assets and the ROE. The size of the bank and ratio of the credit facilities granted by the banks also have is a positive and statistical significance impact on the rate of return on assets and the ROE. ROE ration has a positive impact on the assets, while ROE ratio has not impact on the rate of return of equity. The study recommended that the Jordanian commercial banks must seek to set out limits and certain ceilings for the levels of off-balance items. The study also recommended the regulatory authorities to issue instructions and circulars governing the work of off-balance items and determines the allocations the banks must reserve to face any case where these items have to be paid.

How Have Political Incentives for Local Officials Reduced Environmental Pollution in Resource-Depleted Cities?

Chinese resource-exhausted cities face more severe environmental pollution problems than other cities. In addressing these problems, the way local officials (usually senior party and government leaders) operate is very important, as their focus on political achievements may complicate how they manage environmental pollution in these cities. On the one hand, the traditional Gross Domestic Product-based quest for political achievement may lead top leaders to de-emphasize environmental pollution. On the other hand, changes made in 2003 to the way the performance of Chinese officials is evaluated have encouraged some local senior party and government leaders to pay more attention to environmental problems. Based on this, we analyze the relationship between political incentives and environmental pollution by applying the 2004–2014 panel data from 37 resource-exhausted cities. The findings reveal that firstly, among the factors which impact the environmental pollution of resource-exhausted cities, investment in fixed assets, foreign direct investment, industrial structure, per-capita education expenditure, and population density do not have a significant impact, thus indicating that local openness levels, the degree of industrial upgrading, and local investment in fixed assets are not the key variables in environmental pollution control. Secondly, the extent to which officials vie for political achievement affects environmental pollution in resource-exhausted cities. This depends upon whether the officials are municipal party secretaries or mayors; the former play a greater dynamic role in environmental pollution and have stronger robustness than the latter. The conclusion verifies both the existing authority structure of China and its effectiveness in the control of environmental pollution of resource-exhausted cities. That is to say, in contrast to the principles of the party committees, the mayors are in a subordinate position and often fail to fully and effectively exercise their functions. Accordingly, we point out that the selection of municipal party secretaries, rather than mayors, is particularly important in coming to terms with local environmental pollution.

Nitric oxide, malondialdheyde and non-enzymatic antioxidants assessed in viable spermatozoa from selected infertile men

There are growing evidences that the semen of infertile male population shows higher reactive oxygen species (ROS) levels concomitant with lower antioxidant capacity compared to those detected in semen of fertile population. The plasma membrane of the sperm cell, which has high levels of polyunsaturated fatty acids, renders it particularly sensitive to ROS. The aim of this study was to compare the sperm parameters (concentration, motility, morphology and vitality) and the levels of malondialdehyde (MDA), as marker of lipid peroxidation (LPO), nitric oxide (NO), ascorbic acid (AA), total (GSHt) and oxidized glutathione (GSSG) in viable sperm in a group of 38 infertile patients and in a group of 55 control subjects with unknown reproductive potential. The comparison between variables in infertile patients and controls revealed that the sperm quality was reduced in the infertile group, whereas the levels of NO, AA and GSH were significantly increased in viable spermatozoa from infertile men; however, the endogenous levels of MDA were similar in infertile and control groups. Based on our results, we could speculate that the rise of GSHt and AA levels in viable sperm of infertile group help partially to counteract the damaging effect of ROS and partly prevent a substantial LPO. The observation of the concomitant increase of NO and antioxidant indices in viable spermatozoa of infertile subjects is a novel finding and we think that these results can be useful since the viable sperm population is conceivably used in assisted reproductive technology.