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Sample records for exhaust affects spermatogenesis

  1. Detrimental effects of prenatal exposure to filtered diesel exhaust on mouse spermatogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Naoka; Niwata, Yuichiro; Takeda, Ken [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Chiba (Japan); Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); Oshio, Shigeru [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Chiba (Japan); Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); Ohu University, Department of Hygiene Chemistry, School of Pharmaceutical Sciences, Fukushima (Japan); Ohu University, Department of Hygiene Chemistry, School of Pharmaceutical Sciences, Koriyama, Fukushima (Japan); Yoshida, Seiichi [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); Oita University of Nursing and Health Sciences, Department of Health and Sciences, Oita (Japan); Tsukue, Naomi [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); Sugawara, Isamu [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); The Research Institute of Tuberculosis, Mycobacterial Reference Center, Tokyo (Japan); Takano, Hirohisa [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST), Saitama (Japan); National Institute for Environmental Studies, Environmental Health Sciences Division, Ibaraki (Japan)

    2008-11-15

    We recently showed that prenatal exposure to diesel exhaust (DE) disrupts spermatogenesis in mouse offspring. This study was undertaken to determine whether filtered DE in which 99.97% of diesel exhaust particles >0.3{mu}m in diameter were removed affects spermatogenesis in growing mice. After prenatal exposure to filtered DE for 2-16 days postcoitum, we examined daily sperm production (DSP), testicular histology, serum testosterone levels and mRNA expression of hormone synthesis process-related factors. In the filtered DE exposed group, DSP was markedly reduced at 12 weeks compared with the control group; clean air exposed group. Histological examination showed multinucleated giant cells and partial vacuolation in the seminiferous tubules of the exposed group. Testosterone was elevated significantly at 5 weeks. Moreover, luteinizing hormone receptor mRNA at 5 and 12 weeks, 17{alpha}-hydroxylase/C17-20-lyase and 17{beta}-hydroxysteroid dehydrogenase mRNAs at 12 weeks were significantly elevated. These results suggest that filtered DE retains its toxic effects on the male reproductive system following prenatal exposure. (orig.)

  2. Spermatogenesis, sperm DNA integrity, and testicular hormonal function are differentially affected following cytotoxic therapy

    International Nuclear Information System (INIS)

    Constine, L.S.; Schwartz, C.; Hobbie, W.; Evenson, D.; Hinkle, A.; Palisca, M.; Smudzin, T.; Centola, G.

    1997-01-01

    Purpose: Males treated with irradiation (RT) or certain chemotherapeutic (CT) agents are at risk for testicular damage in the form of germ cell injury and hormonal dysfunction. Sperm DNA structural defects or immaturity may affect reproductive potential both in terms of the likelihood for conception and early fetal loss. Preclinical data provoked our hypothesis that patients with subnormal sperm counts due to cytotoxic therapy could be demonstrated to have defective sperm chromatin; we also questioned whether structural abnormalities might be found in the sperm of patients with normal counts. Although the RT dose threshold for ablation of spermatogenesis is known to be below that for hormonal dysfunction, the relative effects of CT are unclear, which suggested the second component of our investigation. Methods: Eligibility criteria included treatment with CT including an alkylating agent, and/or RT with scattered dose to the testes for a cancer not involving the testes, and remission duration of at least 3 years. Of the 15 study patients, 12 received CT (including cyclophosphamide in 7) and 12 received RT (with peripheral testicular doses of 0-169 cGy, and including 4 also treated to the whole brain with doses below that associated with impaired gonadotropin secretion). Sperm number, motility, morphology and pattern of movement were assessed by computer-assisted spermanalysis, and for chromatin structural integrity and maturation using dual parameter flow cytometric (FC) analysis of acid-induced DNA denaturation. The mean age at tumor diagnosis was 14.4 yrs (range 6.5-36; 12 patients were ≤ 19 years old), and at testing was 25.5 yrs (range 18-46), with a mean interval of 9.7 yrs (range 3-21). Results: Only 3 patients (20%) had normal sperm counts (> 20 million/ml), 2 of whom had not received an alkylating agent but had scattered RT testes doses of 41 cGy and 169 cGy, respectively. These 2 patients had impaired sperm motility (13% and 32%, respectively), and the

  3. Relaxin affects cell organization and early and late stages of spermatogenesis in a coculture of rat testicular cells.

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    Pimenta, M T; Francisco, R A R; Silva, R P; Porto, C S; Lazari, M F M

    2015-07-01

    Relaxin and its receptor RXFP1 are co-expressed in Sertoli cells, and relaxin can stimulate proliferation of Sertoli cells. In this study, we investigated a role of relaxin in spermatogenesis, using a short-term culture of testicular cells of the rat that allowed differentiation of spermatogonia to spermatids. Sertoli, germ, and peritubular myoid cells were the predominant cell types in the culture. Sertoli and germ cells expressed RXFP1. Cultures were incubated without (control) or with 0.5% fetal bovine serum (FBS) or 100 ng/mL H2 relaxin (RLN) for 2 days. Cell organization, number, and differentiation were analyzed after 2 (D2), 5 (D5) or 8 (D8) days of culturing. Although the proportion of germ cells decayed from D2 to D5, the relative contribution of HC, 1C, 2C, and 4C germ cell populations remained constant in the control group during the whole culture. RLN did not affect the proportion of germ cell populations compared with control, but increased gene and/or protein expression of the undifferentiated and differentiated spermatogonia markers PLZF and c-KIT, and of the post-meiotic marker Odf2 in D5. RLN favored organization of cells in tubule-like structures, the arrangement of myoid cells around the tubules, arrangement of c-KIT-positive spermatogonia at the basal region of the tubules, and expression of the cell junction protein β-catenin close to the plasma membrane region. Knockdown of relaxin with small interfering RNA (siRNA) reduced expression of β-catenin at the cell junctions, and shifted its expression to the nucleus. We propose that relaxin may affect spermatogenesis by modulating spermatogonial self renewal and favoring cell contact. © 2015 American Society of Andrology and European Academy of Andrology.

  4. Daily Emotional Labor, Negative Affect State, and Emotional Exhaustion: Cross-Level Moderators of Affective Commitment

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    Hyewon Kong

    2018-06-01

    Full Text Available Employees’ emotional-labor strategies, experienced affects, and emotional exhaustion in the workplace may vary over time within individuals, even within the same day. However, previous studies on these relationships have not highlighted their dynamic properties of these relationships. In addition, although the effects of surface and deep acting on emotional exhaustion have been investigated in emotional-labor research, empirical studies on these relationships still report mixed results. Thus, we suggest that moderators may affect the relationship between emotional labor and emotional exhaustion. Also, this study examines the relationship between emotional labor and emotional exhaustion within individuals by repeated measurements, and verifies the mediating effect of a negative affect state. Finally, our study confirms the moderating effects that affective commitment has on the relationship between emotional labor and emotional exhaustion. Data was collected from tellers who had a high degree of interaction with clients at banks based in South Korea. A total of 56 tellers participated in the survey and responded for five working days. A total of 616 data entries were collected from the 56 respondents. We used a hierarchical linear model (HLM to examine our hypothesis. The results showed that surface-acting emotional labor increases emotional exhaustion; furthermore, the relationship between surface acting emotional labor and emotional exhaustion is mediated by a negative affect state within individuals. In addition, this study verified that affective commitment buffers the negative effects that surface acting emotional labor has on emotional exhaustion. These results suggest that emotional labor is a dynamic process within individuals, and that emotional exhaustion caused by emotional labor differs among individuals, and is dependent upon factors such as the individual’s level of affective commitment.

  5. How job demands affect absenteeism? The mediating role of work-family conflict and exhaustion.

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    Vignoli, Michela; Guglielmi, Dina; Bonfiglioli, Roberta; Violante, Francesco Saverio

    2016-01-01

    To investigate how psychosocial factors (such as job demands and work-family conflict) produce absenteeism in the workplace, using the health impairment process of the job demands-resources model. According to this model, job demands lead to burnout (often measured with the emotional exhaustion component), which in turn could lead to outcomes (such as absenteeism). Work-family conflict (WFC) was also studied, because of contradictory results collected in the existing literature on absenteeism in the workplace, regarding the role of WFC in causing absenteeism. Data were collected on 245 workers using both subjective (questionnaire on psychological risk factors and work-related health) and objective data (sickness leave frequency records). To test the hypothesis that job demands and WFC contribute to absenteeism in the workplace, a subsequent mediation analysis was used, which analysed both (a) the subsequent mediation of WFC and emotional exhaustion and (b) the separate roles played by the mediators proposed (WFC and emotional exhaustion). Job demands affect absenteeism through the subsequent mediation of WFC and emotional exhaustion. In addition, emotional exhaustion mediates the relationship between job demands and absenteeism, while WFC does not. In conclusion, subsequent mediation highlights the role of emotional exhaustion in causing absenteeism; in fact, when emotional exhaustion is included in the analysis, job demands are associated with higher levels of absenteeism. The results of this study suggest that without the concurrent contribution of emotional exhaustion, WFC does not influence absenteeism in the workplace. Our findings are useful for organizations that aim to reduce absenteeism.

  6. The endocannabinoid system and spermatogenesis

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    Paola eGrimaldi

    2013-12-01

    Full Text Available AbstractSpermatogenesis is a complex process in which male germ cells undergo a mitotic phase followed by meiosis and by a morphogenetic process to form mature spermatozoa. Spermatogenesis is under the control of gonadotropins, steroid hormones and it is modulated by a complex network of autocrine and paracrine factors. These modulators ensure the correct progression of germ cell differentiation to form mature spermatozoa. Recently, it has been pointed out the relevance of endocannabinoids as critical modulators of male reproduction. Endocannabinoids are natural lipids able to bind to cannabinoid receptors and whose levels are regulated by specific biosynthetic and degradative enzymes. Together with their receptors and metabolic enzymes, they form the endocannabinoid system (ECS. In male reproductive tracts, they affect Sertoli cell activities, Leydig cell proliferation, germ cell differentiation, sperm motility, capacitation and acrosome reaction. The ECS interferes with the pituitary-gonadal axis, and an intricate crosstalk between ECS and steroid hormones has been highlighted. This mini-review will focus on the involvement of the ECS in the control of spermatogenesis and on the interaction between ECS and steroid hormones.

  7. Molecular control of rodent spermatogenesis

    NARCIS (Netherlands)

    Jan, Sabrina Z.; Hamer, Geert; Repping, Sjoerd; de Rooij, Dirk G.; van Pelt, Ans M. M.; Vormer, Tinke L.

    2012-01-01

    Spermatogenesis is a complex developmental process that ultimately generates mature spermatozoa. This process involves a phase of proliferative expansion, meiosis, and cytodifferentiation. Mouse models have been widely used to study spermatogenesis and have revealed many genes and molecular

  8. Cycling before and after Exhaustion Differently Affects Cardiac Autonomic Control during Heart Rate Matched Exercise

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    Matthias Weippert

    2017-11-01

    Full Text Available During cycling before (PRE and after exhaustion (POST different modes of autonomic cardiac control might occur due to different interoceptive input and altered influences from higher brain centers. We hypothesized that heart rate variability (HRV is significantly affected by an interaction of the experimental period (PRE vs. POST and exercise intensity (HIGH vs. LOW; HIGH = HR > HR at the lactate threshold (HRLT, LOW = HR ≤ HRLT despite identical average HR.Methods: Fifty healthy volunteers completed an incremental cycling test until exhaustion. Workload started with 30 W at a constant pedaling rate (60 revolutions · min−1 and was gradually increased by 30 W · 5 min−1. Five adjacent 60 s inter-beat (R-R interval segments from the immediate recovery period (POST 1–5 at 30 W and 60 rpm were each matched with their HR-corresponding 60 s-segments during the cycle test (PRE 1–5. An analysis of covariance was carried out with one repeated-measures factor (PRE vs. POST exhaustion, one between-subject factor (HIGH vs. LOW intensity and respiration rate as covariate to test for significant effects (p < 0.050 on the natural log-transformed root mean square of successive differences between adjacent R-R intervals (lnRMSSD60s.Results: LnRMSSD60s was significantly affected by the interaction of experimental period × intensity [F(1, 242 = 30.233, p < 0.001, ηp2 = 0.111]. LnRMSSD60s was higher during PRE compared to POST at LOW intensity (1.6 ± 0.6 vs. 1.4 ± 0.6 ms; p < 0.001. In contrast, at HIGH intensity lnRMSSD60s was lower during PRE compared to POST (1.0 ± 0.4 vs. 1.2 ± 0.4 ms; p < 0.001.Conclusion: Identical net HR during cycling can result from distinct autonomic modulation patterns. Results suggest a pronounced sympathetic-parasympathetic coactivation immediately after the cessation of peak workload compared to HR-matched cycling before exhaustion at HIGH intensity. On the opposite, at LOW intensity cycling, a stronger coactivational

  9. Impacts of morphine addiction on spermatogenesis in rats

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    Nasrin Takzare

    2016-05-01

    Full Text Available Background: There are numerous investigations on wide range of issues that disrupt regulatory spermatogenesis, individuals who are exposed to drug abuse faced infertility and immature spermatogenesis. Objective: The aim of this study was to evaluate the addiction effects of morphine and its derivatives on rats spermatogenesis. Materials and Methods: 40 male Wistar rats were randomly divided into 5 equal groups, which were exposed either with intravenous morphine, naloxone, naloxone and morphine, sham (with normal saline injection and a control group without infusion. Spermatogenesis was assessed after three months via histological sections with hematoxylin and eosin staining, using a light microscope based on measurement of spermatogonia, spermatocyte, spermatid, and spermatozoa. Results: Those rats that received opioids had changes in spermatogenesis function. The population of spermatogenesis cycle cells at spermatogonia, spermatocyte, spermatid, and spermatozoa stages was significantly decreased in those rats that received opioid in comparison to the control group (p<0.05. Histological studies revealed that changes in different groups of opioid application might affect sperm formation. Sperm count in morphine group was (0±0 and in naloxone group, naloxone+morphine, sham and control were 235±3.77, 220±3.81, 247.12±6.10 and 250±6.54, respectively (p<0.001. Conclusion: Morphine could affect all spermatogenesis stages

  10. Perinatal exposure to diesel exhaust affects gene expression in mouse cerebrum

    Energy Technology Data Exchange (ETDEWEB)

    Tsukue, Naomi [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Noda, Chiba (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); Japan Automobile Research Institute, Health Effects Research Group, Energy and Environment Research Division, Tsukuba, Ibaraki (Japan); Watanabe, Manabu; Kumamoto, Takayuki; Takeda, Ken [Tokyo University of Science, Department of Hygiene Chemistry, Faculty of Pharmaceutical Sciences, Noda, Chiba (Japan); Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); Takano, Hirohisa [Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi, Saitama (Japan); National Institute for Environmental Studies, Pathophysiology Research Team, Tsukuba, Ibaraki (Japan)

    2009-11-15

    Many environmental toxins alter reproductive function and affect the central nervous system (CNS). Gonadal steroid hormones cause differentiation of neurons and affect brain function and behavior during the perinatal period, and the CNS is thought to be particularly susceptible to toxic insult during this period. It was, therefore, hypothesized that inhalation of diesel exhaust (DE) during the fetal or suckling period would disrupt the sexual differentiation of brain function in mice, and the effects of exposure to DE during the perinatal period on sexual differentiation related gene expression of the brain were investigated. In the fetal period exposure group, pregnant ICR mice were exposed to DE from 1.5 days post-coitum (dpc) until 16 dpc. In the neonatal period exposure group, dams and their offspring were exposed to DE from the day of birth [postnatal day (PND)-0] until PND-16. Then, the cerebrums of males and females at PND-2, -5, and -16 from both groups were analyzed for expression level of mRNA encoding stress-related proteins [cytochrome P450 1A1 (CYP1A1), heme oxygenase-1 (HO-1)] and steroid hormone receptors [estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta), androgen receptor (AR)]. Expression levels of ER alpha and ER beta mRNA were increased in the cerebrum of newborns in the DE exposure groups as well as mRNA for CYP1A1 and HO-1. Results indicate that perinatal exposure to DE during the critical period of sexual differentiation of the brain may affect endocrine function. (orig.)

  11. Spermatogenesis in mammals: proteomic insights.

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    Chocu, Sophie; Calvel, Pierre; Rolland, Antoine D; Pineau, Charles

    2012-08-01

    Spermatogenesis is a highly sophisticated process involved in the transmission of genetic heritage. It includes halving ploidy, repackaging of the chromatin for transport, and the equipment of developing spermatids and eventually spermatozoa with the advanced apparatus (e.g., tightly packed mitochondrial sheat in the mid piece, elongating of the tail, reduction of cytoplasmic volume) to elicit motility once they reach the epididymis. Mammalian spermatogenesis is divided into three phases. In the first the primitive germ cells or spermatogonia undergo a series of mitotic divisions. In the second the spermatocytes undergo two consecutive divisions in meiosis to produce haploid spermatids. In the third the spermatids differentiate into spermatozoa in a process called spermiogenesis. Paracrine, autocrine, juxtacrine, and endocrine pathways all contribute to the regulation of the process. The array of structural elements and chemical factors modulating somatic and germ cell activity is such that the network linking the various cellular activities during spermatogenesis is unimaginably complex. Over the past two decades, advances in genomics have greatly improved our knowledge of spermatogenesis, by identifying numerous genes essential for the development of functional male gametes. Large-scale analyses of testicular function have deepened our insight into normal and pathological spermatogenesis. Progress in genome sequencing and microarray technology have been exploited for genome-wide expression studies, leading to the identification of hundreds of genes differentially expressed within the testis. However, although proteomics has now come of age, the proteomics-based investigation of spermatogenesis remains in its infancy. Here, we review the state-of-the-art of large-scale proteomic analyses of spermatogenesis, from germ cell development during sex determination to spermatogenesis in the adult. Indeed, a few laboratories have undertaken differential protein profiling

  12. The role of Drosophila Merlin in spermatogenesis

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    Omelyanchuk Leonid V

    2008-01-01

    Full Text Available Abstract Background Drosophila Merlin, the homolog of the human Neurofibromatosis 2 (NF2 gene, is important for the regulation of cell proliferation and receptor endocytosis. Male flies carrying a Mer3 allele, a missense mutation (Met177→Ile in the Merlin gene, are viable but sterile; however, the cause of sterility is unknown. Results Testis examination reveals that hemizygous Mer3 mutant males have small seminal vesicles that contain only a few immotile sperm. By cytological and electron microscopy analyses of the Mer3, Mer4 (Gln170→stop, and control testes at various stages of spermatogenesis, we show that Merlin mutations affect meiotic cytokinesis of spermatocytes, cyst polarization and nuclear shaping during spermatid elongation, and spermatid individualization. We also demonstrate that the lethality and sterility phenotype of the Mer4 mutant is rescued by the introduction of a wild-type Merlin gene. Immunostaining demonstrates that the Merlin protein is redistributed to the area associated with the microtubules of the central spindle in telophase and its staining is less in the region of the contractile ring during meiotic cytokinesis. At the onion stage, Merlin is concentrated in the Nebenkern of spermatids, and this mitochondrial localization is maintained throughout sperm formation. Also, Merlin exhibits punctate staining in the acrosomal region of mature sperm. Conclusion Merlin mutations affect spermatogenesis at multiple stages. The Merlin protein is dynamically redistributed during meiosis of spermatocytes and is concentrated in the Nebenkern of spermatids. Our results demonstrated for the first time the mitochondrial localization of Merlin and suggest that Merlin may play a role in mitochondria formation and function during spermatogenesis.

  13. Decision-Making Processes in the Workplace: How Exhaustion, Lack of Resources and Job Demands Impair Them and Affect Performance.

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    Ceschi, Andrea; Demerouti, Evangelia; Sartori, Riccardo; Weller, Joshua

    2017-01-01

    The present study aims to connect more the I/O and the decision-making psychological domains, by showing how some common components across jobs interfere with decision-making and affecting performance. Two distinct constructs that can contribute to positive workplace performance have been considered: decision-making competency (DMCy) and decision environment management (DEM). Both factors are presumed to involve self-regulatory mechanisms connected to decision processes by influencing performance in relation to work environment conditions. In the framework of the job demands-resources (JD-R) model, the present study tested how such components as job demands, job resources and exhaustion can moderate decision-making processes and performance, where high resources are advantageous for decision-making processes and performance at work, while the same effect happens with low job demands and/or low exhaustion. In line with the formulated hypotheses, results confirm the relations between both the decision-making competences, performance (i.e., in-role and extra-role) and moderators considered. In particular, employees with low levels of DMCy show to be more sensitive to job demands toward in-role performance, whereas high DEM levels increase the sensitivity of employees toward job resources and exhaustion in relation to extra-role performance. These findings indicate that decision-making processes, as well as work environment conditions, are jointly related to employee functioning.

  14. Decision-Making Processes in the Workplace: How Exhaustion, Lack of Resources and Job Demands Impair Them and Affect Performance

    Directory of Open Access Journals (Sweden)

    Andrea Ceschi

    2017-05-01

    Full Text Available The present study aims to connect more the I/O and the decision-making psychological domains, by showing how some common components across jobs interfere with decision-making and affecting performance. Two distinct constructs that can contribute to positive workplace performance have been considered: decision-making competency (DMCy and decision environment management (DEM. Both factors are presumed to involve self-regulatory mechanisms connected to decision processes by influencing performance in relation to work environment conditions. In the framework of the job demands-resources (JD-R model, the present study tested how such components as job demands, job resources and exhaustion can moderate decision-making processes and performance, where high resources are advantageous for decision-making processes and performance at work, while the same effect happens with low job demands and/or low exhaustion. In line with the formulated hypotheses, results confirm the relations between both the decision-making competences, performance (i.e., in-role and extra-role and moderators considered. In particular, employees with low levels of DMCy show to be more sensitive to job demands toward in-role performance, whereas high DEM levels increase the sensitivity of employees toward job resources and exhaustion in relation to extra-role performance. These findings indicate that decision-making processes, as well as work environment conditions, are jointly related to employee functioning.

  15. Caffeine Affects Time to Exhaustion and Substrate Oxidation during Cycling at Maximal Lactate Steady State

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    Rogério Santos de Oliveira Cruz

    2015-06-01

    Full Text Available This study analyzed the effects of caffeine intake on whole-body substrate metabolism and exercise tolerance during cycling by using a more individualized intensity for merging the subjects into homogeneous metabolic responses (the workload associated with the maximal lactate steady state—MLSS. MLSS was firstly determined in eight active males (25 ± 4 years, 176 ± 7 cm, 77 ± 11 kg using from two to four constant-load tests of 30 min. On two following occasions, participants performed a test until exhaustion at the MLSS workload 1 h after taking either 6 mg/kg of body mass of caffeine or placebo (dextrose, in a randomized, double-blinded manner. Respiratory exchange ratio was calculated from gas exchange measurements. There was an improvement of 22.7% in time to exhaustion at MLSS workload following caffeine ingestion (95% confidence limits of ±10.3%, p = 0.002, which was accompanied by decrease in respiratory exchange ratio (p = 0.001. These results reinforce findings indicating that sparing of the endogenous carbohydrate stores could be one of the several physiological effects of caffeine during submaximal performance around 1 h.

  16. [Germ cell membrane lipids in spermatogenesis].

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    Wang, Ting; Shi, Xiao; Quan, Song

    2016-05-01

    Spermatogenesis is a complex developmental process in which a diploid progenitor germ cell transforms into highly specialized spermatozoa. During spermatogenesis, membrane remodeling takes place, and cell membrane permeability and liquidity undergo phase-specific changes, which are all associated with the alteration of membrane lipids. Lipids are important components of the germ cell membrane, whose volume and ratio fluctuate in different phases of spermatogenesis. Abnormal lipid metabolism can cause spermatogenic dysfunction and consequently male infertility. Germ cell membrane lipids are mainly composed of cholesterol, phospholipids and glycolipids, which play critical roles in cell adhesion and signal transduction during spermatogenesis. An insight into the correlation of membrane lipids with spermatogenesis helps us to better understand the mechanisms of spermatogenesis and provide new approaches to the diagnosis and treatment of male infertility.

  17. How job demands affect partners' experience of exhaustion: integrating work-family conflict and crossover theory.

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    Bakker, Arnold B; Demerouti, Evangelia; Dollard, Maureen F

    2008-07-01

    This study among 168 couples of dual-earner parents uses insights from previous work-family conflict and crossover research to propose an integrative model delineating how job demands experienced by men and women carry over to the home domain. The authors hypothesized that for both men and women, job demands foster their own work-family conflict (WFC), which in turn contributes to their partners' home demands, family-work conflict (FWC), and exhaustion. In addition, they hypothesized that social undermining mediates the relationship between individuals' WFC and their partners' home demands. The results of structural equation modeling analyses provided strong support for the proposed model. The hypothesis that gender would moderate the model relationships was rejected. These findings integrate previous findings on work-family conflict and crossover theories and suggest fluid boundaries between the work and home domains.

  18. DOES WORK-FAMILY CONFLICT AFFECT THE AUDITOR’S PERFORMANCE?: EXAMINING THE MEDIATING ROLES OF EMOTIONAL EXHAUSTION AND JOB SATISFACTION

    OpenAIRE

    Yustina, Andi Ina; Valerina, Tifanny

    2018-01-01

    This paper examines whether the work-family conflict (related to both work-interfering-family and family-interfering-work) of auditors affects their performance and if so, whether the effect is mediated by emotional exhaustion and job satisfaction. A mail survey is used to deliver a questionnaire to 151 auditors from ten CPA firm in Indonesia. The result shows that emotional exhaustion and job satisfaction fully mediates the relationship of work-family conflict with job performance. The resul...

  19. Spermatogenesis and testicular tumours in ageing dogs

    NARCIS (Netherlands)

    Peters, M. A.; de rooij, D. G.; Teerds, K. J.; van der Gaag, I.; van Sluijs, F. J.

    2000-01-01

    Spermatogenesis was examined in testes from 74 dogs of various breeds without clinically detected testicular disease. A modified Johnsen score system was used to determine whether spermatogenesis deteriorates with ageing. The diameter of seminiferous tubules was measured in dogs without testicular

  20. Spermatogenesis and testicular tumours in ageing dogs

    NARCIS (Netherlands)

    Peters, M. A.; de rooij, D. G.; Teerds, K. J.; van de Gaag, I.; van Sluijs, F. J.

    2001-01-01

    The aims of this investigation were to quantify the changes in canine spermatogenesis that occur during ageing and to study the prevalence of testicular tumours and their effects on spermatogenesis in dogs. Testes from 74 dogs of various breeds without clinically detected testicular disease and from

  1. Understanding spermatogenesis is a prerequisite for treatment

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    Schulze Wolfgang

    2003-11-01

    Full Text Available Abstract Throughout spermatogenesis multiplication, maturation and differentiation of germ cells results in the formation of the male gamete. The understanding of spermatogenesis needs detailed informations about the organization of the germinal epithelium, the structure and function of different types of germ cells, endocrine and paracrine cells and mechanisms, intratesticular and extratesticular regulation of spermatogenesis. Normal germ cells must be discriminated from malformed, apoptotic and degenerating germ cells and tumor cells. Identification of the border line between normal and disturbed spermatogenesis substantiate the diagnosis of impaired male fertility. The profound knowledge of the complicate process of spermatogenesis and all cells or cell systems involved with is the prerequisite to develop concepts for therapy of male infertility or to handle germ cells in the management of assisted reproduction.

  2. [An Investigation of Factors Associated with Emotional Exhaustion among Hospital Nurses: Adherence to "Maternal Affection" and Agreement with Stereotypical Gender Roles].

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    Takai, Rei; Nomura, Kyoko; Hiraike, Haruko; Murakami, Aya; Tanabe, Ayumi; Tsuchiya, Akiko; Okinaga, Hiroko

    2018-01-01

    To investigate factors including adherence to "maternal affection" and stereotypical gender roles associated with emotional exhaustion among hospital nurses. In 2014, among 2,690 workers recruited for this study, 891 participated with written informed consent. Of these, we investigated 464 hospital nurses. Adherence to maternal affection and emotional exhaustion were measured using valid and reliable scales developed by Egami (2005, 12 items) and Kubo (1992, 5 items), respectively. Stereotypical gender role was measured by asking "how much do you agree with the idea that women should stay home and men should work?". Workfamily conflict was measured in terms of the discrepancy in priority in life (i.e., a work or a private life) between the participant's ideal and the real world. The majority of our participants were women (86%), aged 39 or younger (80%), and single (70%). About one-quarter had workfamily conflict (26%) and agreed with the stereotypical gender role (28%). The mean scores of emotional exhaustion and adherence to maternal affection were 17.2 (out of 25) and 30.8 (out of 48), respectively. A stepwise multivariable model showed that being a woman (p=0.028), being young (p=0.022), being single (p=0.007), and having workfamily conflict (pgender role were not significantly associated with emotional exhaustion. This study demonstrated that adherence to "maternal affection" and stereotypical gender roles were not associated with psychological burnout. Special attention should be paid to hospital nurses who are women, young, or single, or who have workfamily conflict.

  3. Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

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    Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

  4. The Glass Half Empty: How Emotional Exhaustion Affects the State-Trait Discrepancy in Self-Reports of Teaching Emotions.

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    Goetz, Thomas; Becker, Eva S; Bieg, Madeleine; Keller, Melanie M; Frenzel, Anne C; Hall, Nathan C

    2015-01-01

    Following from previous research on intensity bias and the accessibility model of emotional self-report, the present study examined the role of emotional exhaustion in explaining the discrepancy in teachers' reports of their trait (habitual) versus state (momentary, "real") emotions. Trait reports (habitual emotions, exhaustion) were assessed via trait questionnaires, and state reports (momentary emotions) were assessed in real time via the experience sampling method by using personal digital assistants (N = 69 high school teachers; 1,089 measures within teachers). In line with our assumptions, multi-level analyses showed that, as compared to the state assessment, teachers reported higher levels of habitual teaching-related emotions of anger, anxiety, shame, boredom, enjoyment, and pride. Additionally, the state-trait discrepancy in self-reports of negative emotions was accounted for by teachers' emotional exhaustion, with high exhaustion levels corresponding with a greater state-trait discrepancy. Exhaustion levels did not moderate the state-trait discrepancy in positive emotions indicating that perceived emotional exhaustion may reflect identity-related cognitions specific to the negative belief system. Implications for research and educational practice are discussed.

  5. The Glass Half Empty: How Emotional Exhaustion Affects the State-Trait Discrepancy in Self-Reports of Teaching Emotions

    Science.gov (United States)

    Goetz, Thomas; Becker, Eva S.; Bieg, Madeleine; Keller, Melanie M.; Frenzel, Anne C.; Hall, Nathan C.

    2015-01-01

    Following from previous research on intensity bias and the accessibility model of emotional self-report, the present study examined the role of emotional exhaustion in explaining the discrepancy in teachers’ reports of their trait (habitual) versus state (momentary, “real”) emotions. Trait reports (habitual emotions, exhaustion) were assessed via trait questionnaires, and state reports (momentary emotions) were assessed in real time via the experience sampling method by using personal digital assistants (N = 69 high school teachers; 1,089 measures within teachers). In line with our assumptions, multi-level analyses showed that, as compared to the state assessment, teachers reported higher levels of habitual teaching-related emotions of anger, anxiety, shame, boredom, enjoyment, and pride. Additionally, the state-trait discrepancy in self-reports of negative emotions was accounted for by teachers’ emotional exhaustion, with high exhaustion levels corresponding with a greater state-trait discrepancy. Exhaustion levels did not moderate the state-trait discrepancy in positive emotions indicating that perceived emotional exhaustion may reflect identity-related cognitions specific to the negative belief system. Implications for research and educational practice are discussed. PMID:26368911

  6. Effect of rejuvenation hormones on spermatogenesis.

    Science.gov (United States)

    Moss, Jared L; Crosnoe, Lindsey E; Kim, Edward D

    2013-06-01

    To review the current literature for the effect of hormones used in rejuvenation clinics on the maintenance of spermatogenesis. Review of published literature. Not applicable. Men who have undergone exogenous testosterone (T) and/or anabolic androgenic steroid (AAS) therapies. None. Semen analysis, pregnancy outcomes, and time to recovery of spermatogenesis. Exogenous testosterone and anabolic androgenic steroids suppress intratesticular testosterone production, which may lead to azoospermia or severe oligozoospermia. Therapies that protect spermatogenesis involve human chorionic gonadotropin (hCG) therapy and selective estrogen receptor modulators (SERMs). The studies examining the effect of human growth hormone (HGH) on infertile men are uncontrolled and unconvincing, but they do not appear to negatively impact spermatogenesis. At present, routine use of aromatase inhibitors is not recommended based on a lack of long-term data. The use of hormones for rejuvenation is increasing with the aging of the Baby Boomer population. Men desiring children at a later age may be unaware of the side-effect profile of hormones used at rejuvenation centers. Testosterone and anabolic androgenic steroids have well-established detrimental effects on spermatogenesis, but recovery may be possible with cessation. Clomiphene citrate, human growth hormone (HGH)/insulin-like growth factor-1 (IGF-1), human chorionic gonadotropin (hCG), and aromatase inhibitors do not appear to have significant negative effects on sperm production, but quality data are lacking. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  7. Spermatogenesis Abnormalities following Hormonal Therapy in Transwomen

    Directory of Open Access Journals (Sweden)

    Sirachai Jindarak

    2018-01-01

    Full Text Available Objective. To measure spermatogenesis abnormalities in transwomen at the time of sex reassignment surgery (SRS and to analyze the association between hormonal therapy duration and infertility severity. Design. Retrospective study. Setting. University hospital. Patients. One-hundred seventy-three transwomen who underwent SRS from January 2000 to December 2015. Interventions. All orchidectomy specimens were retrospectively reviewed and classified. History of hormonal therapy duration was retrieved from medical records. Main Outcome Measures. Histological examinations of orchidectomy specimens were performed to assess spermatogenesis. Results. One-hundred seventy-three orchidectomy specimens were evaluated. Histological examinations showed maturation arrest in 36.4%, hypospermatogenesis in 26%, Sertoli cell-only syndrome in 20.2%, normal spermatogenesis in 11%, and seminiferous tubule hyalinization in 6.4% of the specimens. Spermatogenesis abnormality severity was not associated with the total therapy duration (P=0.81 or patient age at the time of surgery (P=0.88. Testicular volumes and sizes were associated with spermatogenesis abnormality severity (P=0.001 and P=0.026, right testicle and left testicle, resp.. Conclusion(s. Feminizing hormonal treatment leads to reductions in testicular germ cell levels. All transwomen should be warned about this consequence, and gamete preservation should be offered before starting hormonal treatment.

  8. In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

    Directory of Open Access Journals (Sweden)

    Odagiri Takashi

    2010-03-01

    Full Text Available Abstract Background Epidemiological studies have suggested that suspended particulate matter (SPM causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA and monoamine levels in the CNS were assessed. Methods Mice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3 for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC. Results and Discussion Mice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased

  9. Recombination homeostasis of meiosis during spermatogenesis under nicotine treatment

    Directory of Open Access Journals (Sweden)

    Zhai Jingli

    2018-01-01

    Full Text Available Cigarette smoking can affect male fertility via the quality of semen. To explore the effects of nicotine, a major component of cigarettes, on meiotic recombination during spermatogenesis, C57BL/6J male mice were injected with nicotine at a dosage of 0.2 mg/100 g body weight daily for 35 days (nicotine-treated group; mice in the control group were injected with isopycnic normal saline. According to previous expression profiles of mouse sperm, a subset of meiosis-related genes was pooled using bioinformatic analysis. Protein expression was compared between the two groups using by Western blotting and immunohistochemistry. Recombination frequency during the meiosis phase of spermatogenesis was estimated by combined use of chromosome spread and immunofluorescence staining in mouse testes. Data mining analysis indicated that 4 genes that express meiotic topoisomerase-like protein SPO11, MutS protein homolog 4 (MSH4, strand exchange protein RAD51 and MutL protein homologue 1 (MLH1, were associated with the meiosis recombination process. The results of Western blotting and immunohistochemistry further showed that the protein expression of SPO11 (0.73-fold and MSH4 (0.73-fold was downregulated in murine testes after nicotine treatment, whereas the protein expression of both RAD51 (2.06-fold and MLH1 (1.40-fold was upregulated. Unexpectedly, we did not detect a significant difference in recombination frequency in meiosis during spermatogenesis in the nicotine-treated group as compared to the control. Taken together, these results indicate that nicotine can affect the expression profile of restructuring-related genes, but it does not significantly change the recombination frequency during male meiosis. These findings suggest there is a self-regulating mechanism during meiotic chromosome restructuring in male mice that responds to environmental stress.

  10. Sustainability and Substitution of Exhaustible Natural Resources : How Resource Prices Affect Long-Term R&D Investments

    NARCIS (Netherlands)

    Bretschger, L.; Smulders, J.A.

    2003-01-01

    Traditional resource economics has been criticised for assuming too high elasticities of substitution, not observing material balance principles and relying too much on planner solutions to obtain long-term growth.By analysing a multi-sector R&D based endogenous growth model with exhaustible natural

  11. Mll5 is required for normal spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Damian B Yap

    Full Text Available Mll5 is currently a member of the Mll family of SET domain histone methyltransferase proteins but studies have also showed that it could be part of the SET3 branch of proteins. Recently, constitutive knock out animal studies have shown that Mll5 is required for proper haematopoietic stem cell differentiation, and loss of Mll5 results in synthetic lethality for genome de-methylation. Mll5 deficient male mice are infertile and here we analyse the consequences of Mll5 deficiency for spermatogenesis.Mll5 deficient male mice, but not female mice, are infertile. Here we show using RNA in-situ hybridization that Mll5 is expressed in the germ cells of the testes of wild type mice. Consistent with the expression of Mll5, we demonstrate by electron microscopy, video microscopy and in vitro fertilisation techniques that Mll5 deficient mice have defects in terminal maturation and packaging of sperm. The defects seen include detachment of the acrosomal cap and impaired excess cytoplasm removal. Functional tests of sperm motility show a lack of progressive motility of spermatozoa from Mll5 deficient animals. None of these defects could be rescued by in vitro fertilization. Using microarray analysis we show that transcripts implicated in spermatogenesis are dysregulated.Our data demonstrate a clear role of Mll5 in mammalian spermatogenesis at the level of terminal differentiation providing further support for its classification in the SET3 branch of proteins. Moreover, this study identifies Tlk2, Utx, Gpr64, Sult4a1, Rap2ip, Vstm2 and HoxA10 as possible Mll5 targets that together may account for the observed spermatozoa maturation defects.

  12. Decision-making processes in the workplace : how exhaustion, lack of resources and job demands impair them and affect performance

    NARCIS (Netherlands)

    Ceschi, A.; Demerouti, E.; Sartori, R.; Weller, J.

    2017-01-01

    The present study aims to connect more the I/O and the decision-making psychological domains, by showing how some common components across jobs interfere with decision-making and affecting performance. Two distinct constructs that can contribute to positive workplace performance have been

  13. Decision-making processes in the workplace : How exhaustion, lack of resources and job demands impair them and affect performance

    NARCIS (Netherlands)

    Ceschi, Andrea; Demerouti, Evangelia; Sartori, Riccardo; Weller, J.A.

    2017-01-01

    The present study aims to connect more the I/O and the decision-making psychological domains, by showing how some common components across jobs interfere with decision-making and affecting performance. Two distinct constructs that can contribute to positive workplace performance have been

  14. Intercellular adhesion molecules (ICAMs) and spermatogenesis

    Science.gov (United States)

    Xiao, Xiang; Mruk, Dolores D.; Cheng, C. Yan

    2013-01-01

    BACKGROUND During the seminiferous epithelial cycle, restructuring takes places at the Sertoli–Sertoli and Sertoli–germ cell interface to accommodate spermatogonia/spermatogonial stem cell renewal via mitosis, cell cycle progression and meiosis, spermiogenesis and spermiation since developing germ cells, in particular spermatids, move ‘up and down’ the seminiferous epithelium. Furthermore, preleptotene spermatocytes differentiated from type B spermatogonia residing at the basal compartment must traverse the blood–testis barrier (BTB) to enter the adluminal compartment to prepare for meiosis at Stage VIII of the epithelial cycle, a process also accompanied by the release of sperm at spermiation. These cellular events that take place at the opposite ends of the epithelium are co-ordinated by a functional axis designated the apical ectoplasmic specialization (ES)—BTB—basement membrane. However, the regulatory molecules that co-ordinate cellular events in this axis are not known. METHODS Literature was searched at http://www.pubmed.org and http://scholar.google.com to identify published findings regarding intercellular adhesion molecules (ICAMs) and the regulation of this axis. RESULTS Members of the ICAM family, namely ICAM-1 and ICAM-2, and the biologically active soluble ICAM-1 (sICAM-1) are the likely regulatory molecules that co-ordinate these events. sICAM-1 and ICAM-1 have antagonistic effects on the Sertoli cell tight junction-permeability barrier, involved in Sertoli cell BTB restructuring, whereas ICAM-2 is restricted to the apical ES, regulating spermatid adhesion during the epithelial cycle. Studies in other epithelia/endothelia on the role of the ICAM family in regulating cell movement are discussed and this information has been evaluated and integrated into studies of these proteins in the testis to create a hypothetical model, depicting how ICAMs regulate junction restructuring events during spermatogenesis. CONCLUSIONS ICAMs are crucial

  15. Cellular ontogeny of RBMY during human spermatogenesis and its ...

    Indian Academy of Sciences (India)

    2012-12-13

    Dec 13, 2012 ... Genetic analysis of men with infertility and subfertility has led to identification of genes .... USA) that recognizes the N-terminus of human RBMY. (N-RBMY) at a .... During spermatogenesis, quantitative changes in rates of RNA ...

  16. Gene expression profiles of mouse spermatogenesis during recovery from irradiation

    DEFF Research Database (Denmark)

    Shah, Fozia J; Tanaka, Masami; Nielsen, John E

    2009-01-01

    BACKGROUND: Irradiation or chemotherapy that suspend normal spermatogenesis is commonly used to treat various cancers. Fortunately, spermatogenesis in many cases can be restored after such treatments but knowledge is limited about the re-initiation process. Earlier studies have described the cell......BACKGROUND: Irradiation or chemotherapy that suspend normal spermatogenesis is commonly used to treat various cancers. Fortunately, spermatogenesis in many cases can be restored after such treatments but knowledge is limited about the re-initiation process. Earlier studies have described...... the cellular changes that happen during recovery from irradiation by means of histology. We have earlier generated gene expression profiles during induction of spermatogenesis in mouse postnatal developing testes and found a correlation between profiles and the expressing cell types. The aim of the present...... work was to utilize the link between expression profile and cell types to follow the cellular changes that occur during post-irradiation recovery of spermatogenesis in order to describe recovery by means of gene expression. METHODS: Adult mouse testes were subjected to irradiation with 1 Gy...

  17. Exhaust gas processing facility

    International Nuclear Information System (INIS)

    Terada, Shin-ichi.

    1995-01-01

    The facility of the present invention comprises a radioactive liquid storage vessel, an exhaust gas dehumidifying device for dehumidifying gases exhausted from the vessel and an exhaust gas processing device for reducing radioactive materials in the exhaust gases. A purified gas line is disposed to the radioactive liquid storage vessel for purging exhaust gases generated from the radioactive liquid, then dehumidified and condensed liquid is recovered, and exhaust gases are discharged through an exhaust gas pipe disposed downstream of the exhaust gas processing device. With such procedures, the scale of the exhaust gas processing facility can be reduced and exhaust gases can be processed efficiently. (T.M.)

  18. Whole and particle-free diesel exhausts differentially affect cardiac electrophysiology, blood pressure, and autonomic balance in heart failure-prone rats

    Science.gov (United States)

    Epidemiologic studies strongly link short-term exposures to vehicular traffic and particulate matter (PM) air pollution with adverse cardiovascular events, especially in those with preexisting cardiovascular disease. Diesel engine exhaust (DE) is a key contributor to urban ambien...

  19. Estrogen receptor alpha localization in the testes of men with normal spermatogenesis Estrogen receptor alpha localization in the testes of men with normal spermatogenesis

    Directory of Open Access Journals (Sweden)

    Eliza Filipiak

    2012-10-01

    Full Text Available It is known that estrogens act on the male reproductive tract by binding to estrogen receptors (ER a and
    b. However, studies on ER localization in the human testis are discordant. The aim of this study was to investigate
    the localization of ERa in the testes of adult men with normal spermatogenesis. Semen analysis of ten adult men
    revealed azoospermia. FSH, LH and testosterone serum concentrations were within normal values, and the volume
    of the testes was normal, hence obstructive azoospermia was suspected. The tissues from testicular surgical
    biopsies were fixed in Bouin’s fluid and embedded in paraffin. Assessments of the seminiferous epithelium (scoring
    10 to –1, the number of Leydig cells (scoring 1 to 5, the areal fraction of intertubular space (IS, measurements
    of seminiferous tubule diameter, and the thickness of the tubular wall, were performed on microscopic
    sections. Immunohistochemical staining was applied with monoclonal antibodies against ERa. The mean spermatogenesis
    score was 10 points; IS — 30.6 ± 8.1%; seminiferous tubule diameter — 193.9 ± 19.4 μm; thickness of
    tubular wall — 7.44 ± 1.1 μm; number of Leydig cells — 1.6 ± 1.1 points. Immunohistochemical staining showed
    the localization of ERa to be in the Sertoli and Leydig cell cytoplasm, while ERa was absent in germ cells. The
    results of testicular tissue analysis confirmed its normal structure and normal, full spermatogenesis. The presence
    of ERa in Sertoli and Leydig cells in normal human testis demonstrated in this study suggests that estrogens may
    affect testicular function.It is known that estrogens act on the male reproductive tract by binding to estrogen receptors (ER a and
    b. However, studies on ER localization in the human testis are discordant. The aim of this study was to investigate
    the localization of ERa in the testes of adult men with normal spermatogenesis. Semen

  20. Piwil1 mediates meiosis during spermatogenesis in chicken.

    Science.gov (United States)

    Xu, Lu; Chang, Guobin; Ma, Teng; Wang, Hongzhi; Chen, Jing; Li, Zhiteng; Guo, Xiaomin; Wan, Fang; Ren, Lichen; Lu, Wei; Chen, Guohong

    2016-03-01

    Piwil1 mediates spermatogenesis and ensures stable cell division rates in germline cells in mammals. However, the involvement of Piwil1 in poultry spermatogenesis and meiosis is poorly understood. In the present study, we used TaqMan RT-qPCR to characterize Piwil1 mRNA expression in different types of spermatogenic cells, including primordial germ cells (PGCs), spermatogonial stem cells (SSCs), spermatogonia cells (Sa), tetraploid cells (Tp), round sperm cells (Rs), mature sperm, and in PGCs treated with retinoic acid. Our results revealed that Piwil1 is differentially expressed during spermatogenesis in chicken. Compared to PGCs, SSCs, Tp, and Sa, Rs cells presented the highest Piwil1 mRNA expression levels. Retinoic acid significantly upregulated Piwil1 and Stra8 mRNA expression as well as Piwil1 levels in chicken PGCs. In addition, retinoic acid induced PGCs to progress through all the meiotic stages, eventually leading to haploid cell formation, which was determined using flow cytometry and western blot analysis. Taken together, our results showed that during spermatogenesis, Piwil1 was first expressed at low levels in germ stem cells, PGCs, and SSCs. Its expression levels increased during later meiosis stages. Finally, no expression was detected in mature sperm after meiosis. Treatment of PGCs with retinoic acid further demonstrated that Piwil1 plays a key role in meiosis during chicken spermatogenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Yangjing Capsule Ameliorates Spermatogenesis in Male Mice Exposed to Cyclophosphamide

    Directory of Open Access Journals (Sweden)

    Hongle Zhao

    2015-01-01

    Full Text Available Yangjing capsule (YC, a traditional Chinese compound herbal preparation, has been proven as an effective drug to improve spermatogenesis in clinical practice. However, its pharmacological mechanisms were not fully clarified. This study was designed to investigate the protective effects of YC on spermatogenesis in the mouse model of spermatogenesis dysfunction induced by cyclophosphamide (CP. The administration of YC significantly increased the epididymal index, sperm count, and sperm motility of model mice. Histopathological changes demonstrated that CP caused obvious structural damage to testis, which were reversed by the administration of YC. Results from TUNEL assay showed that treatment with YC dramatically decreased the apoptosis of spermatogenic cell induced by CP. Moreover, YC treatment could inhibit the mRNA and protein expression of Bax to Bcl-2 and also raised expression of AR at both mRNA and protein levels. These data suggest that YC might ameliorate spermatogenesis in male mice exposed to CP through inhibiting the apoptosis of spermatogenic cell and enhancing the actions of testosterone in spermatogenesis.

  2. Misexpression of cyclin B3 leads to aberrant spermatogenesis.

    Science.gov (United States)

    Refik-Rogers, Jale; Manova, Katia; Koff, Andrew

    2006-09-01

    Mus musculus cyclin B3 is an early meiotic cyclin that is expressed in leptotene and zygotene phases during gametogenesis. In order to determine whether downregulation of cyclin B3 at zygotene-pachytene transition was important for normal spermatogenesis, we investigated the consequences of expressing H. sapiens cyclin B3 after zygotene in mouse testes. Prolonging expression of cyclin B3 until the end of meiosis led to a reduction in sperm counts and disruption of spermatogenesis in four independent lines of transgenic mice. There were three distinct morphological defects associated with the ectopic expression of cyclin B3. Seminiferous tubules were either depleted of germ cells, had an abnormal cell mass in the lumen, or were characterized by the presence of abnormal round spermatids. These defects were associated with increased apoptosis in the testes. These results suggest that downregulation of cyclin B3 at the zygotene-pachytene transition is required to ensure normal spermatogenesis.

  3. Y chromosome microdeletions and alterations of spermatogenesis, patient approach and genetic counseling.

    Science.gov (United States)

    Rives, Nathalie

    2014-05-01

    Infertility affects 15% of couples at reproductive age and human male infertility appears frequently idiopathic. The main genetic causes of spermatogenesis defect responsible for non-obstructive azoospermia and severe oligozoospermia are constitutional chromosomal abnormalities and microdeletions in the azoospermia factor region of the Y chromosome. The improvement of the Yq microdeletion screening method gave new insights in the mechanism responsible for the genesis of Yq microdeletions and for the consequences of the management of male infertility and genetic counselling in case of assisted reproductive technology. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. [Identification of the meiotic events in grasshopper spermatogenesis].

    Science.gov (United States)

    Liu, Meng-Hao; Zhao, Kai-Qiang; Wang, Ya-Dong; Yang, Meng-Ping; Zhao, Ning-Ning; Yang, Da-Xiang

    2012-12-01

    The grasshoppers are ideal materials to study various meiotic stages of spermatogenesis due to their easy availability, fairly large chromosomes, and fewer numbers of chromosomes. It is easy to make temporary squash preparation of grasshopper testes; however, it is usually difficult for the beginners to differentiate between stages of meiosis. In view of this, we demonstrated the method of identification of meiotic stages by chromosome number and chromosome conformation, taking spermatogonial meiosis of Locusta migratoria manilensis as an example. We described briefly the mitosis of spermatogonia and the spermatogenesis of this species as well.

  5. Impact of chronic exposure to gasoline automotive exhaust gases on some bio-markers affecting the hormonal sexual function, the kidney function and blood parameters, in the rat

    International Nuclear Information System (INIS)

    Smaoui, M.; Ghorbel, F.; Boujelbene, M.; El Feki, A.; Makni-Ayadi, F.

    2000-01-01

    The automotive exhaust gases constitute an important source of urban pollution. The objective of this study is to explore, in the rat, the effects of repetitive exposure to gasoline automotive exhaust gases on the level variations of serum testosterone, blood lead, bone lead, blood carbon monoxide, on the kidney function and blood parameters. 200 rats inhaling a mixture of air and automotive exhaust gas (10/1, v/v), are distributed in 4 groups treated during 15, 30, 45 and 60 days. They are compared to non treated controls. Our results show a decrease of serum testosterone level. This result is the origin of a masculine sterility already demonstrated in our laboratory. This sterility seems to be reversible because polluted rats regain their sexual activity, 2 months after stopping of the pollutant treatment. An increase of the blood carbon monoxide level with a lead accumulation in blood and in the tail is noticed. Biochemical analyses show that glycaemia, urea, and creatininaemia increase in treated animals. The urinary rate of creatinine decreases. These results indicate kidney deficiency. Our results show also in treated animals an increase of the number of red blood corpuscles, of hematocrit, of the blood level of haemoglobin and of the VGM, and a decrease of the CGMH. The carbon monoxide and the lead detected in blood of the treated animals are the origin of these perturbations. In conclusion, our results show that gasoline automotive exhaust gas induces, in the rat, a decrease of serum testosterone level. The carbon monoxide and the lead present in the exhaust gas, and detected in blood and in the tail of the treated animals, are the origin of sexual, kidney and blood parameters perturbations. (author)

  6. Estrogen receptor alpha localization in the testes of men with normal spermatogenesis.

    Science.gov (United States)

    Filipiak, Eliza; Suliborska, Dagmara; Laszczynska, Maria; Walczak-Jedrzejowska, Renata; Oszukowska, Elzbieta; Marchlewska, Katarzyna; Kula, Krzysztof; Slowikowska-Hilczer, Jolanta

    2013-10-08

    It is known that estrogens act on the male reproductive tract by binding to estrogen receptors (ER) α and β. However, studies on ER localization in the human testis are discordant. The aim of this study was to investigate the localization of ERα in the testes of adult men with normal spermatogenesis. Semen analysis of ten adult men revealed azoospermia. FSH, LH and testosterone serum concentrations were within normal values, and the volume of the testes was normal, hence obstructive azoospermia was suspected. The tissues from testicular surgical biopsies were fixed in Bouin's fluid and embedded in paraffin. Assessments of the seminiferous epithelium (scoring 10 to -1), the number of Leydig cells (scoring 1 to 5), the areal fraction of intertubular space (IS), measurements of seminiferous tubule diameter, and the thickness of the tubular wall, were performed on microscopic sections. Immunohistochemical staining was applied with monoclonal antibodies against ERα. The mean spermatogenesis score was 10 points; IS - 30.6 ± 8.1%; seminiferous tubule diameter - 193.9 ± 19.4 μm; thickness of tubular wall - 7.44 ± 1.1 μm; number of Leydig cells - 1.6 ± 1.1 points. Immunohistochemical staining showed the localization of ERα to be in the Sertoli and Leydig cell cytoplasm, while ERα was absent in germ cells. The results of testicular tissue analysis confirmed its normal structure and normal, full spermatogenesis. The presence of ERα in Sertoli and Leydig cells in normal human testis demonstrated in this study suggests that estrogens may affect testicular function.

  7. Protamines and spermatogenesis in Drosophila and Homo sapiens : A comparative analysis.

    Science.gov (United States)

    Kanippayoor, Rachelle L; Alpern, Joshua H M; Moehring, Amanda J

    2013-04-01

    The production of mature and motile sperm is a detailed process that utilizes many molecular players to ensure the faithful execution of spermatogenesis. In most species that have been examined, spermatogenesis begins with a single cell that undergoes dramatic transformation, culminating with the hypercompaction of DNA into the sperm head by replacing histones with protamines. Precise execution of the stages of spermatogenesis results in the production of motile sperm. While comparative analyses have been used to identify similarities and differences in spermatogenesis between species, the focus has primarily been on vertebrate spermatogenesis, particularly mammals. To understand the evolutionary basis of spermatogenetic variation, however, a more comprehensive comparison is needed. In this review, we examine spermatogenesis and the final packaging of DNA into the sperm head in the insect Drosophila melanogaster and compare it to spermatogenesis in Homo sapiens.

  8. Methamidophos alters sperm function and DNA at different stages of spermatogenesis in mice

    International Nuclear Information System (INIS)

    Urióstegui-Acosta, Mayrut; Hernández-Ochoa, Isabel; Sánchez-Gutiérrez, Manuel; Piña-Guzmán, Belem; Rafael-Vázquez, Leticia; Solís-Heredia, M.J.; Martínez-Aguilar, Gerardo; Quintanilla-Vega, Betzabet

    2014-01-01

    Methamidophos (MET) is a highly toxic organophosphate (OP) pesticide that is widely used in developing countries. MET has male reproductive effects, including decreased fertility. We evaluated MET effects on sperm quality, fertilization and DNA integrity, exploring the sensitivity of different stages of spermatogenesis. Adult male mice received MET (3.75 or 5 mg/kg-bw/ip/day/4 days) and were euthanized 1, 28 or 45 days post-treatment (dpt) to evaluate MET's effects on epididymal maturation, meiosis or mitosis, respectively. Spermatozoa were obtained from the cauda epididymis–vas deferens and were evaluated for sperm quality, acrosome reaction (AR; Coomassie staining), mitochondrial membrane potential (by JC-1), DNA damage (comet assay), oxidative damage (malondialdehyde (MDA) production), in vitro fertilization and protein phosphorylation (immunodetection), and erythrocyte acetylcholinesterase (AChE) activity. At 1-dpt, MET inhibited AChE (43–57%) and increased abnormal cells (6%). While at 28- and 45-dpt, sperm motility and viability were significantly reduced with an increasing MET dose, and abnormal morphology increased at 5 mg/kg/day/4 days. MDA and mitochondrial activity were not affected at any dose or time. DNA damage (OTM and %DNA) was observed at 5 mg/kg/day/4 days in a time-dependent manner, whereas both parameters were altered in cells from mice exposed to 3.75 mg/kg/day/4 days only at 28-dpt. Depending on the time of collection, initial-, spontaneous- and induced-AR were altered at 5 mg/kg/day/4 days, and the fertilization capacity also decreased. Sperm phosphorylation (at serine and tyrosine residues) was observed at all time points. Data suggest that meiosis and mitosis are the more sensitive stages of spermatogenesis for MET reproductive toxicity compared to epididymal maturation. - Highlights: • Methamidophos alters sperm cell function at different stages of spermatogenesis. • Testicular stages of spermatogenesis are more sensitive to

  9. Methamidophos alters sperm function and DNA at different stages of spermatogenesis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Urióstegui-Acosta, Mayrut; Hernández-Ochoa, Isabel [Departamento de Toxicología, CINVESTAV-IPN, D.F. (Mexico); Sánchez-Gutiérrez, Manuel [Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Hidalgo (Mexico); Piña-Guzmán, Belem [Instituto Politécnico Nacional-UPIBI, D.F. (Mexico); Rafael-Vázquez, Leticia; Solís-Heredia, M.J.; Martínez-Aguilar, Gerardo [Departamento de Toxicología, CINVESTAV-IPN, D.F. (Mexico); Quintanilla-Vega, Betzabet, E-mail: mquintan@cinvestav.mx [Departamento de Toxicología, CINVESTAV-IPN, D.F. (Mexico)

    2014-09-15

    Methamidophos (MET) is a highly toxic organophosphate (OP) pesticide that is widely used in developing countries. MET has male reproductive effects, including decreased fertility. We evaluated MET effects on sperm quality, fertilization and DNA integrity, exploring the sensitivity of different stages of spermatogenesis. Adult male mice received MET (3.75 or 5 mg/kg-bw/ip/day/4 days) and were euthanized 1, 28 or 45 days post-treatment (dpt) to evaluate MET's effects on epididymal maturation, meiosis or mitosis, respectively. Spermatozoa were obtained from the cauda epididymis–vas deferens and were evaluated for sperm quality, acrosome reaction (AR; Coomassie staining), mitochondrial membrane potential (by JC-1), DNA damage (comet assay), oxidative damage (malondialdehyde (MDA) production), in vitro fertilization and protein phosphorylation (immunodetection), and erythrocyte acetylcholinesterase (AChE) activity. At 1-dpt, MET inhibited AChE (43–57%) and increased abnormal cells (6%). While at 28- and 45-dpt, sperm motility and viability were significantly reduced with an increasing MET dose, and abnormal morphology increased at 5 mg/kg/day/4 days. MDA and mitochondrial activity were not affected at any dose or time. DNA damage (OTM and %DNA) was observed at 5 mg/kg/day/4 days in a time-dependent manner, whereas both parameters were altered in cells from mice exposed to 3.75 mg/kg/day/4 days only at 28-dpt. Depending on the time of collection, initial-, spontaneous- and induced-AR were altered at 5 mg/kg/day/4 days, and the fertilization capacity also decreased. Sperm phosphorylation (at serine and tyrosine residues) was observed at all time points. Data suggest that meiosis and mitosis are the more sensitive stages of spermatogenesis for MET reproductive toxicity compared to epididymal maturation. - Highlights: • Methamidophos alters sperm cell function at different stages of spermatogenesis. • Testicular stages of spermatogenesis are more sensitive to

  10. 5-aza-2′-deoxycytidine impairs mouse spermatogenesis at multiple stages through different usage of DNA methyltransferases

    International Nuclear Information System (INIS)

    Song, Ning; Endo, Daisuke; Song, Bin; Shibata, Yasuaki; Koji, Takehiko

    2016-01-01

    Mammalian spermatogenesis is a progressive process comprising spermatogonial proliferation, spermatocytic meiosis, and later spermiogenesis, which is considered to be under the regulation of epigenetic parameters. To gain insights into the significance of DNA methylation in early spermatogenesis, 5-azadC was used as a molecular biological tool to mimic the level of DNA methylation in vivo. Since the drug is incorporated into DNA during the S-phase, spermatogonia and spermatocytes would be affected primarily in mouse spermatogenesis. Adult male ICR mice were intraperitoneally injected with 5-azadC at a dose of 0.25 mg/kg/day for 10 consecutive days, allowing us to examine its maximum effect on the kinetics of spermatogonia and spermatocytes. In this short-term protocol, 5-azadC induced significant histological abnormalities, such as a marked increase in apoptosis of spermatogonia and spermatocytes, followed by severe loss of spermatids, while after termination of 5-azadC treatment, normal histology was restored in the testis within 35 days. Quantification of the methylation level of CCGG sites as well as whole DNA showed spermatogonial hypomethylation, which correlated with increased apoptosis of spermatogonia. Interestingly, the hypomethylated cells were simultaneously positive for tri-methylated histone H3 at K4. On the other hand, no changes in methylation level were found in spermatocytes, but PCNA staining clearly showed disordered accumulation of S-phase spermatocytes, which increased their apoptosis in stage XII. In addition, different immunohistochemical staining pattern was found for DNA methyltransferases (DNMTs); DNMT1was expressed in the majority of all germ cells, but DNMT3a and b were only expressed in spermatogonia. Our results indicate that 5-azadC caused DNA hypomethylation in spermatogonia, but induced prolongation of S-phase in spermatocytes, resulting in the induction of apoptosis in both cases. Thus, 5-azadC affects spermatogenesis at more than

  11. Confocal Analysis of Nuclear Lamina Behavior during Male Meiosis and Spermatogenesis in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Fabiana Fabbretti

    Full Text Available Lamin family proteins are structural components of a filamentous framework, the nuclear lamina (NL, underlying the inner membrane of nuclear envelope. The NL not only plays a role in nucleus mechanical support and nuclear shaping, but is also involved in many cellular processes including DNA replication, gene expression and chromatin positioning. Spermatogenesis is a very complex differentiation process in which each stage is characterized by nuclear architecture dramatic changes, from the early mitotic stage to the sperm differentiation final stage. Nevertheless, very few data are present in the literature on the NL behavior during this process. Here we show the first and complete description of NL behavior during meiosis and spermatogenesis in Drosophila melanogaster. By confocal imaging, we characterized the NL modifications from mitotic stages, through meiotic divisions to sperm differentiation with an anti-laminDm0 antibody against the major component of the Drosophila NL. We observed that continuous changes in the NL structure occurred in parallel with chromatin reorganization throughout the whole process and that meiotic divisions occurred in a closed context. Finally, we analyzed NL in solofuso meiotic mutant, where chromatin segregation is severely affected, and found the strict correlation between the presence of chromatin and that of NL.

  12. Expression pattern of phb2 and its potential function in spermatogenesis of scallop ( Chlamys farreri)

    Science.gov (United States)

    Han, Tiantian; Ma, Xiaoshi; Liang, Shaoshuai; Gao, Beibei; Zhang, Zhifeng

    2015-12-01

    Prohibitin (PHB) participates in several biological processes including apoptosis, transcription regulation and suppression of cell proliferation in mammals. In this study, we cloned the full-length cDNA of prohibitin 2 ( Cf-phb2) from the testis of scallop ( Chlamys farreri). The deduced amino acid sequence presented a characteristic of PHB family with the PHB domain, and clustered with PHB2 of other species. Temporal and spatial expression of Cf-phb2 in testis during the reproductive cycle was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization. The expression of Cf-phb2 in the testis increased when testis developed from the resting stage to mature stage. The mRNA abundance of Cf-phb2 was the highest at mature stage, which was about 15-fold higher than that at proliferative stage. The expression of Cf-phb2 could be detected by in situ hybridization in all types of germ cells in testis, including spermatogonia, spermatocytes, spermatids and spermatozoa. The intensity of the signal increased with the spermatogenesis and was the highest in spermatids, which suggested that CF-PHB2 might affect the spermatogenesis of C. farreri.

  13. Putting things in place for fertilization: discovering roles for importin proteins in cell fate and spermatogenesis

    Directory of Open Access Journals (Sweden)

    Kate L. Loveland

    2015-01-01

    Full Text Available Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to control access by transcription factors and other nuclear proteins to genomic DNA, to achieve appropriate modulation of cellular behaviors affecting cell fate. Importin-mediated nucleocytoplasmic transport relies on their specific recognition of cargoes, with each importin binding to distinct and overlapping protein subsets. Knowledge of importin function has expanded substantially in regard to three key developmental systems: embryonic stem cells, muscle cells and the germ line. In the decade since the potential for regulated nucleocytoplasmic transport to contribute to spermatogenesis was proposed, we and others have shown that the importins that ferry transcription factors into the nucleus perform additional roles, which control cell fate. This review presents key findings from studies of mammalian spermatogenesis that reveal potential new pathways by which male fertility and infertility arise. These studies of germline genesis illuminate new ways in which importin proteins govern cellular differentiation, including via directing proteins to distinct intracellular compartments and by determining cellular stress responses.

  14. Ultrastructure of Spermatogenesis of the Paradise Fish, Macropodus opercularis

    Directory of Open Access Journals (Sweden)

    Tsung-Han Lee

    2006-09-01

    Full Text Available The intricate process of spermatogenesis in the paradise fish, Macropodus opercularis, was studied. In this species, the unrestricted or lobular type testes lining the caudal side of the body cavity are translucent and slender. Spermatogonia occur along the length of the tubules and the development of sperm takes place within cysts formed by Sertoli cells. Spermiogenesis involves preparatory morphological events followed by conspicuous modifications such as the movement of the centrioles, completion of the nuclear condensation, reduction of the cytoplasm, and the final differentiation of the flagellar complex. Mature spermatozoon has an oval nucleus, condensed chromatin, and typical 9 + 2 flagellar axoneme but lack acrosome. The role of the material in the nucleus and the cytoplasm as it reaches the Sertoli cell in the control of spermatogenesis is discussed.

  15. Role of cyclins in controlling progression of mammalian spermatogenesis

    OpenAIRE

    WOLGEMUTH, DEBRA J.; MANTEROLA, MARCIA; VASILEVA, ANA

    2013-01-01

    Cyclins are key regulators of the mammalian cell cycle, functioning primarily in concert with their catalytic partners, the cyclin-dependent kinases (Cdks). While their function during mitosis in somatic cells has been extensively documented, their function during both mitosis and meiosis in the germ line is poorly understood. From the perspective of cell cycle regulation there are several aspects of mammalian spermatogenesis that suggest unique modes of regulation and hence, possible unique ...

  16. Extremely low-frequency magnetic fields can impair spermatogenesis recovery after reversible testicular damage induced by heat.

    Science.gov (United States)

    Tenorio, Bruno Mendes; Ferreira Filho, Moisés Bonifacio Alves; Jimenez, George Chaves; de Morais, Rosana Nogueira; Peixoto, Christina Alves; Nogueira, Romildo de Albuquerque; da Silva Junior, Valdemiro Amaro

    2014-06-01

    Male infertility is often related to reproductive age couples experiencing fertility-related issues. Men may have fertility problems associated with reversible testicular damage. Considering that men have been increasingly exposed to extremely low-frequency magnetic fields generated by the production, distribution and use of electricity, this study analyzed whether 60 Hz and 1 mT magnetic field exposure may impair spermatogenesis recovery after reversible testicular damage induced by heat shock using rats as an experimental model. Adult male rats were subjected to a single testicular heat shock (HS, 43 °C for 12 min) and then exposed to the magnetic field for 15, 30 and 60 d after HS. Magnetic field exposure during the spermatogenesis recovery induced changes in testis components volume, cell ultrastructure and histomorphometrical parameters. Control animals had a reestablished and active spermatogenesis at 60 d after heat shock, while animals exposed to magnetic field still showed extensive testicular degeneration. Magnetic field exposure did not change the plasma testosterone. In conclusion, extremely low-frequency magnetic field may be harmful to fertility recovery in males affected by reversible testicular damage.

  17. A novel transcriptional factor Nkapl is a germ cell-specific suppressor of Notch signaling and is indispensable for spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Hidenobu Okuda

    Full Text Available Spermatogenesis is an elaborately regulated system dedicated to the continuous production of spermatozoa via the genesis of spermatogonia. In this process, a variety of genes are expressed that are relevant to the differentiation of germ cells at each stage. Although Notch signaling plays a critical role in germ cell development in Drosophila and Caenorhabditis elegans, its function and importance for spermatogenesis in mammals is controversial. We report that Nkapl is a novel germ cell-specific transcriptional suppressor in Notch signaling. It is also associated with several molecules of the Notch corepressor complex such as CIR, HDAC3, and CSL. It was expressed robustly in spermatogonia and early spermatocytes after the age of 3 weeks. Nkapl-deleted mice showed complete arrest at the level of pachytene spermatocytes. In addition, apoptosis was observed in this cell type. Overexpression of NKAPL in germline stem cells demonstrated that Nkapl induced changes in spermatogonial stem cell (SSC markers and the reduction of differentiation factors through the Notch signaling pathway, whereas testes with Nkapl deleted showed inverse changes in those markers and factors. Therefore, Nkapl is indispensable because aberrantly elevated Notch signaling has negative effects on spermatogenesis, affecting SSC maintenance and differentiation factors. Notch signaling should be properly regulated through the transcriptional factor Nkapl.

  18. Air flow quality analysis of modenas engine exhaust system

    Science.gov (United States)

    Shahriman A., B.; Mohamad Syafiq A., K.; Hashim, M. S. M.; Razlan, Zuradzman M.; Khairunizam W. A., N.; Hazry, D.; Afendi, Mohd; Daud, R.; Rahman, M. D. Tasyrif Abdul; Cheng, E. M.; Zaaba, S. K.

    2017-09-01

    The simulation process being conducted to determine the air flow effect between the original exhaust system and modified exhaust system. The simulations are conducted to investigate the flow distribution of exhaust gases that will affect the performance of the engine. The back flow pressure in the original exhaust system is predicted toward this simulation. The design modification to the exhaust port, exhaust pipe, and exhaust muffler has been done during this simulation to reduce the back flow effect. The new designs are introduced by enlarging the diameter of the exhaust port, enlarge the diameter of the exhaust pipe and created new design for the exhaust muffler. Based on the result obtained, there the pulsating flow form at the original exhaust port that will increase the velocity and resulting the back pressure occur. The result for new design of exhaust port, the velocity is lower at the valve guide in the exhaust port. New design muffler shows that the streamline of the exhaust flow move smoothly compare to the original muffler. It is proved by using the modification exhaust system, the back pressure are reduced and the engine performance can be improve.

  19. Portable Exhauster Position Paper

    International Nuclear Information System (INIS)

    KRISKOVICH, J.R.

    1999-01-01

    This document identifies the tasks that are involved in preparing the ''standby'' portable exhauster to support Interim Stabilization's schedule for saltwell pumping. A standby portable exhaust system will be assigned to any facility scheduled to be saltwell pumped with the exception of 241-S farm, 241-SX farm or 241-T farm. The standby portable exhauster shall be prepared for use and placed in storage. The standby portable exhaust system shall be removed from storage and installed to ventilate tanks being pumped that reach 25% LFL. There are three tasks that are evaluated in this document. Each task shall be completed to support portable exhaust system installation and operation. They are: Pre Installation Task; Portable Exhaust System Storage Task; and Portable Exhaust System Installation and Operation Task

  20. Local Exhaust Ventilation

    DEFF Research Database (Denmark)

    Madsen, Ulla; Breum, N. O.; Nielsen, Peter V.

    Capture efficiency of a local exhaust system, e.g. a kitchen hood, should include only contaminants being direct captured. In this study basic concepts of local exhaust capture efficiency are given, based on the idea of a control box. A validated numerical model is used for estimation of the capt......Capture efficiency of a local exhaust system, e.g. a kitchen hood, should include only contaminants being direct captured. In this study basic concepts of local exhaust capture efficiency are given, based on the idea of a control box. A validated numerical model is used for estimation...

  1. Exhaustion from prolonged gambling

    Directory of Open Access Journals (Sweden)

    Fatimah Lateef

    2013-01-01

    Full Text Available Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities. Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion. Recently, three patients were seen at the Department of Emergency Medicine, presenting with exhaustion from prolonged involvement in gambling activities. The cases serve to highlight some of the physical consequences of prolonged gambling.

  2. Inhibin B as a serum marker of spermatogenesis

    DEFF Research Database (Denmark)

    Jensen, T K; Andersson, A M; Hjollund, N H

    1997-01-01

    = -0.61, P sperm concentration (r = -0.40, P sperm concentration (r = 0.38, P sperm counts below 20 mill/mL among men who's inhibin B....... All blood samples were analyzed in the same laboratory. Median sperm concentration and the percentage of morphologically normal spermatozoa were significantly higher among men from centre A (56.0 mill/mL and 42.5%), compared with men from centre B (44.8 mill/mL and 39%). Men from centre B had...... reproductive health, may serve as a new marker of spermatogenesis, in addition to sperm concentration and serum FSH....

  3. Effects of lead, molybdenum, rubidium, arsenic and organochlorines on spermatogenesis in fish: Monitoring at Mekong Delta area and in vitro experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Sonoko [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Miura, Chiemi [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Ito, Aki [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Bui Cach Tuyen [Nong Lam University, Thu Duc Distr., Ho Chi Minh City (Viet Nam); Miura, Takeshi [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan)]. E-mail: miutake@agr.ehime-u.ac.jp

    2007-06-05

    To estimate the influence of water contaminants on fish reproduction in the Mekong Delta area, we sampled cultivated male catfish (Pangasianodon hypophthalmus), investigated testicular development, and measured persistent organic pollutants (POPs) and trace element levels in muscle and liver, respectively. Various testes sizes were observed although sampling took place during a short period. Histological analysis revealed that all developmental stages of germ cells were observed in catfish with large testis, whereas only necrotic spermatogonia but no other germ cells were observed in catfish with small testis. In small testis, furthermore, vacuolization and hypertrophy of Sertoli cells were observed. Measurement of POPs in muscle and trace elements in liver demonstrated that there were negative correlations between GSI and the concentrations of Pb, Mo, Rb and As. To clarify possible direct effects of Pb, Mo, Rb and As on spermatogenesis in fish, we investigated the effects of these trace elements on spermatogenesis using in vitro testicular organ culture of Japanese eel (Anguilla japonica). Treatment with each of the trace elements alone did not affect spermatogenesis. However, treatment with 10{sup -7} M of Pb, 10{sup -5} and 10{sup -4} M of Mo, 10{sup -5}-10{sup -3} M of Rb or 10{sup -5} M of As inhibited the spermatogenesis induced by 11-ketotestosterone (11KT). Furthermore, treatment with 10{sup -4} M of As in combination with 11KT caused necrosis of testicular fragments. Taken together, these results are consistent with the hypothesis that Pb, Mo, Rb and As can exert inhibitory effects on spermatogenesis in catfish inhabiting the Mekong Delta area.

  4. The induction of non-disjunction by irradiation in mammalian oogenesis and spermatogenesis

    International Nuclear Information System (INIS)

    Hansmann, I.; Probeck, H.D.

    1979-01-01

    Test systems to detect non-disjunction in oogenesis and spermatogenesis are described and the results obtained from a study of radiation effects on non-disjunction presented. It is shown that X-rays may induce non-disjunction in mouse oogenesis and spermatogenesis, thereby increasing the potential risk of aneuploidies among the F1 generation. (C.F.)

  5. The postnatal progeny development of males whose sexual cells were irradiated during different stages of spermatogenesis

    International Nuclear Information System (INIS)

    Lepekhin, N.P.; Palyga, G.F.

    1995-01-01

    Distinct genetic radiosensitivity if germinal cells of males irradiated during different stages of spermatogenesis with doses of 0.25-5.0 Gy leads to reduction in vital newborn rats number in the first generation progeny and to elevated postnatal mortality rate. These postnatal ontogeny disorders depend on the irradiation dose and spermatogenesis stage for a moment irradiation. 11 refs.; 4 tabs

  6. Unemployment Benefit Exhaustion

    DEFF Research Database (Denmark)

    Filges, Trine; Pico Geerdsen, Lars; Knudsen, Anne-Sofie Due

    2015-01-01

    This systematic review studied the impact of exhaustion of unemployment benefits on the exit rate out of unemployment and into employment prior to benefit exhaustion or shortly thereafter. Method: We followed Campbell Collaboration guidelines to prepare this review, and ultimately located 12...

  7. Duplex tab exhaust nozzle

    Science.gov (United States)

    Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

    2012-01-01

    An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

  8. Diesel exhaust emissions : health effects

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, M. [Natural Resources Canada, Sudbury, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2009-07-01

    Despite modern day ventilation, underground miners are exposed to diesel particulate matter (DPM) composed of elemental carbon, organic carbon, sulphates, metals and ashes. Diesel exhaust contains over 40 air contaminants that have been recognized as toxic, carcinogenic or reproductive and developmental hazards. Nearly all components of diesel exhaust interact with the human body at the bloodstream or tissue level. This presentation discussed the following 4 potential levels of threat posed by the physical and chemical nature of diesel exhaust: (1) cancer of the lungs and bladder, (2) toxins that affect the nervous, endocrine, reproductive and immune system as well as the liver and kidneys, (3) fine particulate matter that can cause premature death and an increase in respiratory illness, and (4) nitrogen oxides that contribute to increased ozone and smog. Non-cancer health effects from short-term exposure include acute irritation and respiratory symptoms. This presentation also referred to cancer risk assessments of diesel exhaust by national, state, and world health organizations. Particulate exposure standards for Canada, Quebec, Ontario and the United States were listed along with the percentage of DPM samples in excess of various exposure limits in 2008 according to Canadian underground mine data. DPM concentration levels in mines are in the range that environmental agencies would consider high for general population exposure. Solutions for underground mines include pollution control at the source; use of modern engines with certification for underground mining; emissions based maintenance; exhaust treatment; use of clean or alternative fuels such as hydrogen; regular sampling and monitoring; ventilation; training and technology transfer; and regulations. tabs., figs.

  9. Ultrastructural study of spermatogenesis in Phoronopsis harmeri (Lophophorata, Phoronida)

    Science.gov (United States)

    Reunov, Arkadiy; Klepal, Waltraud

    2004-02-01

    The process of sperm development in Phoronopsis harmeri was studied by electron microscopy. Developing spermatogenical cells are aggregated around the capillaries of the haemal plexus. The spermatogonia, which are situated around the capillary walls of the caeca, are remarkable for the presence of germ-line vesicles and contain their centrioles near the cell membrane. The spermatocytes and spermatids are flagellated cells arranged in clusters. During spermiogenesis the basal body/flagellum complex migrates to the apical pole of the spermatid. The acrosome-like structure arises from material produced by the Golgi complex. It lacks a surrounding membrane and has a fibrillar content. The nucleus elongates and the condensation of chromatin is caused by an activation of 'initiation centres'. The late spermatid and the spermatozoon appear as two-armed 'V'-shaped cells in which one arm contains the nucleus and posteriorly located mitochondria, and the other one is the axoneme. Spermatogenesis of P. harmeri is an interesting example of gamete differentiation where advanced sperm structure is combined with a plesiomorphic pattern of sperm development characterized as 'flagellate spermatogenesis'.

  10. Effect of acetylsalicylic acid on spermatogenesis in adult albino mice

    International Nuclear Information System (INIS)

    Ameer, M.K.; Tahrir, M.

    2015-01-01

    Spermatogenesis in male albino mice. Study Design: Laboratory based randomized controlled trial. Place and Duration of Study: Department of Anatomy University of Health Sciences, Lahore from Apr, 2012 to Dec, 2012. Material and Methods: Thirty nine male albino mice, 6-8 weeks old weighing 30 - 5 gm, were used; these were randomly divided into three groups having thirteen mice in each using random numbers table. Group A served as a control and was given distilled water orally via oral gavage 10 ml per kg for 30 days. Group B was given acetylsalicylic acid 100 mg/kg dissolved in 10 ml distilled orally for a period of 30 days. Group C was given acetylsalicylic acid 25 mg/kg dissolved in 2.5 ml distilled orally for a period of 30 days. Animals were sacrificed 24 hours after the last dose and the testes were removed, fixed in Bouin's fixative for 48 hours. Five microns thick sections of processed tissue were stained with H and E and PAS for calculation of Johnsen score and diameter of seminiferous tubules. Serum testosterone level was measured by testosterone enzyme immunoassay test kits. Results: Microscopic examination demonstrated that ASA treatment lead to statistically significant increase in the mean Johnsen score and mean diameter of seminiferous tubules. Conclusion: It was concluded from the current study that ASA treatment enhances spermatogenesis. (author)

  11. Ultrastructure of spermatogenesis in the sea star, Asterina minor.

    Science.gov (United States)

    Yamagata, A

    1988-02-01

    The ultrastructural features of spermatogenesis were investigated in the hermaphroditic sea star Asterina minor. The primordial germ cells in the genital rachis contain small clusters of electron-dense material (nuage material) and a stack of annulate lamellae. They also have a flagellum and basal body complex situated close to the Golgi complex. After the development of the genital rachis into the ovotestis, spermatogenic cells increase in number and differentiation begins. Nuage material is observed in spermatogonia, but it gradually disappears in spermatocytes. The annulate lamellae do not exist beyond the early spermatogonial stage. By contrast, a flagellum and basal body complex are found throughout spermatogenesis. The Golgi-derived proacrosomal vesicles appear in the spermatocyte and coalesce to form an acrosomal vesicle in the early spermatid. The process of acrosome formation is as follows: (1) a lamella of endoplasmic reticulum (ER) continuous with the outer nuclear membrane encloses the posterior portion of the acrosomal vesicle; (2) the vesicle attaches to the cell membrane with its anterior portion; (3) periacrosomal material accumulates in the space between the acrosomal vesicle and the ER; (4) the nucleus proper changes its features to surround the acrosome; (5) amorphous, electron-dense material is deposited under the electron-dense disk; and (6) the nucleus forms a hollow opposite the electron-dense material.

  12. In vitro mouse spermatogenesis with an organ culture method in chemically defined medium.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Sanjo

    Full Text Available We previously reported the successful induction and completion of mouse spermatogenesis by culturing neonatal testis tissues. The culture medium consisted of α-minimum essential medium (α-MEM, supplemented with Knockout serum replacement (KSR or AlbuMAX, neither of which were defined chemically. In this study, we formulated a chemically defined medium (CDM that can induce mouse spermatogenesis under organ culture conditions. It was found that bovine serum albumin (BSA purified through three different procedures had different effects on spermatogenesis. We also confirmed that retinoic acid (RA played crucial roles in the onset of spermatogonial differentiation and meiotic initiation. The added lipids exhibited weak promoting effects on spermatogenesis. Lastly, luteinizing hormone (LH, follicle stimulating hormone (FSH, triiodothyronine (T3, and testosterone (T combined together promoted spermatogenesis until round spermatid production. The CDM, however, was not able to produce elongated spermatids. It was also unable to induce spermatogenesis from the very early neonatal period, before 2 days postpartum, leaving certain factors necessary for spermatogenic induction in mice unidentified. Nonetheless, the present study provided important basic information on testis organ culture and spermatogenesis in vitro.

  13. Tokamak fusion reactor exhaust

    International Nuclear Information System (INIS)

    Harrison, M.F.A.; Harbour, P.J.; Hotston, E.S.

    1981-08-01

    This report presents a compilation of papers dealing with reactor exhaust which were produced as part of the TIGER Tokamak Installation for Generating Electricity study at Culham. The papers are entitled: (1) Exhaust impurity control and refuelling. (2) Consideration of the physical problems of a self-consistent exhaust and divertor system for a long burn Tokamak. (3) Possible bundle divertors for INTOR and TIGER. (4) Consideration of various magnetic divertor configurations for INTOR and TIGER. (5) A appraisal of divertor experiments. (6) Hybrid divertors on INTOR. (7) Refuelling and the scrape-off layer of INTOR. (8) Simple modelling of the scrape-off layer. (9) Power flow in the scrape-off layer. (10) A model of particle transport within the scrape-off plasma and divertor. (11) Controlled recirculation of exhaust gas from the divertor into the scrape-off plasma. (U.K.)

  14. Cellular content and biosynthesis of polyamines during rooster spermatogenesis.

    Science.gov (United States)

    Oliva, R; Vidal, S; Mezquita, C

    1982-01-01

    The natural polyamines spermine and spermidine, and the diamine putrescine, were extracted from rooster testis cells separated by sedimentation at unit gravity, and from vas-deferens spermatozoa. The ratios spermine/DNA and spermidine/DNA were kept relatively constant throughout spermatogenesis, whereas the ratio putrescine/DNA rose in elongated spermatids. The cellular content of spermine, spermidine and putrescine decreased markedly in mature spermatozoa. Two rate-limiting enzymes in the biosynthetic pathway of polyamines, ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase, showed their highest activities at the end of spermiogenesis and were not detectable in vas-deferens spermatozoa. A marked reduction in cell volume during spermiogenesis without a parallel decrease in the cellular content of polyamines suggests the possibility that the marked changes in chromatin composition and structure occurring in rooster late spermatids could take place in an ambience of high polyamine concentration. Images PLATE 1 PMID:7159401

  15. Long term effects of ionizing radiation on mouse spermatogenesis

    International Nuclear Information System (INIS)

    Hacker-Klom, U.

    1985-01-01

    The effects of acute or split dose exposure to radiation on murine stem cell spermatogonia were analysed. Flow cytometry was applied to estimate the percentages of haploid germ cells (round and elongated spermatids) up to 12 months after irradiation. The recovery in the number of haploid germ cells continued gradually during the period under observation. The intervals between the two equal doses in split dose exposures were 0, 4, 8, 24 and 48 hours. Split doses that were 24 h or 48 h apart had more harmful effects on spermatogenesis than split doses with 4 or 8 hours intervals or acute exposures. The repair capacity of the stem cell spermatogonia was remarkably high. (orig.)

  16. Mammalian spermatogenesis as a biologic dosimeter for radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, U; Schumann, J; Goehde, W; Mueller, K [Muenster Univ. (Germany, F.R.)

    1981-01-01

    Mouse spermatogenesis was used as an in vivo test system obviously suitable as a biologic dosimeter. Ionizing irradiation induced changes in the freqency distribution of the cellular DNA content of whole testis preparations. These changes can be analysed by flow cytometry. Such measurements deliver information on: (1) an increase of the coefficient of variation of the DNA histograms of some spermatogenic cells, (2) induction of diploid mature sperm, and (3) the dose-depending inactivation of the highly sensitive differentiated spermatogonia. In this model especially No. 3 delivers quantitative information on the cytotoxic action of ionizing irradiation and chemical noxae as well, whereas Nos 1 and 2 may be used as qualitative criteria of mutagenic action of physical and chemical agents, No. 2 obviously being more sensitive than No. 1.

  17. Internal Auger emitters: effects on spermatogenesis and oogenesis in mice

    International Nuclear Information System (INIS)

    Rao, D.V.; Mylavarapu, V.B.; Sastry, K.S.R.; Howell, R.W.

    1988-01-01

    The in vivo biological effects of Auger emitters are investigated using [A] spermatogenesis in mouse testis, and [B] oogenesis in mouse ovary as experimental models. Spermhead survival and induction of abnormal sperm, following intratesticular administration of radiopharmaceuticals, were the end points in Model A. Of interest in Model B is primary oocyte survival after intraperitoneal injection of the radiochemicals. The effectiveness of the Auger emitter is determined relative to its beta emitting companion or external X-rays in the absence of such an analogue. Results reveal pronounced effects of Auger emitters on all end points, not dependent on mode of administration. The efficacy of the Auger emitter is related intimately to its subcellular distribution, which, is governed by the chemical form of the carrier molecule. Conventional dosimetry is inadequate and biophysically meaningful dosimetric approaches are needed to understand in vivo effects of Auger emitters. (author)

  18. Spermatogenesis and sperm ultrastructure in the polychaete genus Ophryotrocha (Dorvilleidae)

    Science.gov (United States)

    Pfannenstiel, Hans-Dieter; Grünig, Charlotte

    1990-06-01

    The details of spermatogenesis and spermiogenesis are described for Ophryotrocha puerilis. The ultrastructure of mature sperm is shown for O. puerilis, O. hartmanni, O. gracilis, O. diadema, O. labronica, and O. notoglandulata. Clusters of sixteen cells each are proliferated by two stem cells in each setigerous segment of O. puerilis representing the very early stages of both oogenesis and spermatogenesis. In each spermatocyte-I cluster, the cells are interconnected by cytoplasmic bridges. Early, clusters are enveloped by peritoneal sheath cells. These transient gonad walls break down prior to meiosis. The meiotic processes may start in the clusters with the cells still interconnected, or during breakdown of the original cluster, giving rise to smaller subclusters of both spermatocytes I and spermatocytes II with various numbers of cells. Finally, spermatid tetrads are present. As spermiogenesis progresses, the tetrads disintegrate. Golgi vesicles in both spermatocytes and spermatids contain electron-dense material, presumably preacrosomal. The acrosome is formed by such vesicles. In the six species studied here, the acrosomes appear to be of a similar overall structure but are of different shape. Centrioles are usually located beneath the acrosome. The distal centriole forms the basal body of a flagellum-like cytoplasmic process. The microtubules of these flagellar equivalents do not show a normal ciliar arrangement. The flagellar equivalent appears to be non-motile. In O. hartmanni and in O. notoglandulata, a flagellar equivalent is missing. Microtubules originating from the proximal end of the distal centriole stretch to the nuclear envelope. This feature appears to be especially conspicuous in O. puerilis and in O. labronica. In O. labronica and in O. notoglandulata, bundles of microtubules paralleling the cell perimeter appear to stabilise the sperm. Various numbers of mitochondria are either randomly distributed around the nucleus or accumulate on one side

  19. Misregulation of spermatogenesis genes in Drosophila hybrids is lineage-specific and driven by the combined effects of sterility and fast male regulatory divergence.

    Science.gov (United States)

    Gomes, S; Civetta, A

    2014-09-01

    Hybrid male sterility is a common outcome of crosses between different species. Gene expression studies have found that a number of spermatogenesis genes are differentially expressed in sterile hybrid males, compared with parental species. Late-stage sperm development genes are particularly likely to be misexpressed, with fewer early-stage genes affected. Thus, a link has been posited between misexpression and sterility. A more recent alternative explanation for hybrid gene misexpression has been that it is independent of sterility and driven by divergent evolution of male-specific regulatory elements between species (faster male hypothesis). The faster male hypothesis predicts that misregulation of spermatogenesis genes should be independent of sterility and approximately the same in both hybrids, whereas sterility should only affect gene expression in sterile hybrids. To test the faster male hypothesis vs. the effect of sterility on gene misexpression, we analyse spermatogenesis gene expression in different species pairs of the Drosophila phylogeny, where hybrid male sterility occurs in only one direction of the interspecies cross (i.e. unidirectional sterility). We find significant differences among genes in misexpression with effects that are lineage-specific and caused by sterility or fast male regulatory divergence. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  20. Getting older can be exhausting.

    Science.gov (United States)

    Mittal, Rohit; Ford, Mandy L; Coopersmith, Craig M

    2014-07-29

    Sepsis is a disease that affects primarily the aged. Although mortality is higher in both older septic patients and aged septic mice, the mechanisms underlying decreased survival in older hosts are incompletely understood. New work by Inoue and colleagues demonstrates persistent inflammation and T-cell exhaustion in older septic patients and aged septic mice. The clinical significance of these findings is manifested not only in increased mortality but also in a marked difference in secondary infections in older patients as long as a month following ICU admission.

  1. Effects of exogenous hormones on spermatogenesis in the male prairie dog (Cynomys ludovicianus).

    Science.gov (United States)

    Foreman, D

    1998-01-01

    Male prairie dogs (Cynomys ludovicianus) breed anually and have complete testicular regression. Changes in the seminiferous tubules during the annual cycle have been described recently (Foreman, 1997). This is the first description of spermatogenesis in such a species. The definition of tubular stages during the cycle allows for evaluation of the effects of exogenous hormones, hemicastration, and hemicryptorchidism on spermatogenesis during the annual cycle. Hemicastration was performed during stages of the annual cycle to determine effects of exogenous hormones on remaining testes. Hemicryptorchidism was also done during stages of the annual cycle. FSH, LH, and testosterone were given in high and low doses for short- or long-term treatment periods during stages of the annual cycle. Testicular weights and counts of cell types in tubules of control and treated testes were made on testis tissues. Hemicastration during the out-of-season period does not cause compensatory hypertrophy of the remaining testis, but during recrudescence, hypertrophy of the remaining testis occurs. Hemicastration does not prevent loss of weight by the remaining testis during regression. The seminiferous epithelium of hemicryptorchid prairie dog testes shows damage during spermatogenic activity but not during testicular inactivity. Similarly, hemicryptorchid 15-day-old rat testes do not show damage from hemicryptorchidism. Long-term treatment with FSH preparations during testicular inactivity increased testis weights, spermatogonial proliferation, and spermatocyte differentiation in conjunction with Sertoli cell differentiation. Short-term treatments with low doses increased spermatogonial proliferation and abnormal meiotic activity. Both long- and short-term treatments with LH caused increased sloughing of germ cells and stimulated Leydig and Sertoli cells. Testosterone propionate injections stimulated Sertoli secretions but not Leydig cell activity. Hemicastration during inactivity does

  2. Detection of quantitative trait loci causing abnormal spermatogenesis and reduced testis weight in the small testis (Smt) mutant mouse.

    Science.gov (United States)

    Bolor, Hasbaira; Wakasugi, Noboru; Zhao, Wei Dong; Ishikawa, Akira

    2006-04-01

    The small testis (Smt) mutant mouse is characterized by a small testis of one third to one half the size of a normal testis, and its spermatogenesis is mostly arrested at early stages of meiosis, although a small number of spermatocytes at the late prophase of meiosis and a few spermatids can sometimes be seen. We performed quantitative trait locus (QTL) analysis of these spermatogenic traits and testis weight using 221 F2 males obtained from a cross between Smt and MOM (Mus musculus molossinus) mice. At the genome-wide 5% level, we detected two QTLs affecting meiosis on chromosomes 4 and 13, and two QTLs for paired testis weight as a percentage of body weight on chromosomes 4 and X. In addition, we found several QTLs for degenerated germ cells and multinuclear giant cells on chromosomes 4, 7 and 13. Interestingly, for cell degeneration, the QTL on chromosome 13 interacted epistatically with the QTL on chromosome 4. These results reveal polygenic participation in the abnormal spermatogenesis and small testis size in the Smt mutant.

  3. Affect

    NARCIS (Netherlands)

    Cetinic, M.; Diamanti, J.; Szeman, I.; Blacker, S.; Sully, J.

    2017-01-01

    This chapter historicizes four divergent but historically contemporaneous genres of affect theory – romantic, realist, speculative, and materialist. While critics credited with the turn to affect in the 1990s wrote largely in the wake of poststructuralism from the perspective of gender and queer

  4. Cytological evaluation of spermatogenesis: a novel and simple diagnostic method to assess spermatogenesis in non-obstructive azoospermia using testicular sperm extraction specimens.

    Science.gov (United States)

    Hessel, M; de Vries, M; D'Hauwers, K W M; Fleischer, K; Hulsbergen-van de Kaa, C A; Braat, D D M; Ramos, L

    2015-05-01

    Most of the non-obstructive azoospermia (NOA)-patients have only focal spermatogenesis which results in insufficient numbers of spermatozoa to reach the ejaculate. In ≈50% of these NOA-patients testicular sperm extraction (TESE) is successful and intracytoplasmic sperm injection (ICSI) is pursued. We studied whether (i) spermatogenesis can be evaluated by defining the ratios between Sertoli cells, pachytene spermatocytes and spermatozoa in a testicular cell suspension, and (ii) these ratios are associated with the outcome of fertility treatment. A retrospective cohort study was conducted between June 2007 and August 2012. In this period, 441 consecutive ICSI-TESE cycles were performed in 212 couples. For each TESE biopsy, the ratios between Sertoli cells, pachytene spermatocytes and spermatozoa were calculated. A control population of 32 vasectomized men was used to define cut-off values for complete spermatogenesis. Based on the pachytene to sperm ratio (P/Sp) and number of spermatozoa per 100 Sertoli cells (#Sp/100SC) groups were defined as complete spermatogenesis, hypospermatogenesis and partial maturation arrest (MA). Validation of the cytological diagnoses was performed by comparing the results of cytology to the histological evaluation of spermatogenesis in 40 cases. In 92.5%, a perfect match was observed and in the three remaining cases cytology corresponded well with the results of TESE. Couples with complete spermatogenesis have a higher ongoing pregnancy rate after the first treatment cycle compared to couples with hypospermatogenesis (34 vs. 16%; p = 0.02) and partial MA (34 vs. 19%; p = 0.11). In conclusion, pachytene spermatocytes, spermatozoa and Sertoli cells can be easily identified and counted in a cell suspension and their ratios can be successfully used to diagnose the level of spermatogenic impairment. This pilot study indicates that once successful spermatozoa retrieval is achieved, treatment outcome declines when spermatogenesis is

  5. Selective gas exhaustion method

    International Nuclear Information System (INIS)

    Hirano, Yoichi

    1998-01-01

    The present invention provides a method capable of evacuating gases at an exhaustion rate which varies depending on the kind of gases. For example, in a thermonuclear experimental device, a hydrogen gas exhaustion rate is determined to 0 and an exhaustion rate for other impure gases is made greater. Namely, a baffle plate is cooled to a temperature to a level at which the vapor pressure of gases to evacuate a baffle plate is required in a pump incorporating a baffle plate, for example, a cryopump or a sorption pump. In this case, the level of the vapor pressure required for evacuating the exhaustion gas ingredients is 1 x 10 -8 Torr or less, preferably, 1 x 10 -9 Torr. In a thermonuclear experimental device, a gas having a lower boiling point next to hydrogen is neon, but neon is scarcely present in natural world. Nitrogen has a lower boiling point next thereto, and if the temperature is lowered to such a level that the vapor pressure for evacuating gases such as nitrogen, and carbon monoxide, oxygen, fluorine, argon or methane having a boiling point at or lower than nitrogen is required. Then, evacuation rate sufficient for gases other than hydrogen gas can be obtained. (I.S.)

  6. Aerodynamic Control of Exhaust

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    In the autumn of 1985 the Unive!Sity of Aalborg was approached by the manufacturer C. P. Aaberg, who had obtained aerodynilmic control of the exhaust by means of injection. The remaining investigations comprising optimizations of the system with regard to effect, consumption, requirements...

  7. Exhaust bypass flow control for exhaust heat recovery

    Science.gov (United States)

    Reynolds, Michael G.

    2015-09-22

    An exhaust system for an engine comprises an exhaust heat recovery apparatus configured to receive exhaust gas from the engine and comprises a first flow passage in fluid communication with the exhaust gas and a second flow passage in fluid communication with the exhaust gas. A heat exchanger/energy recovery unit is disposed in the second flow passage and has a working fluid circulating therethrough for exchange of heat from the exhaust gas to the working fluid. A control valve is disposed downstream of the first and the second flow passages in a low temperature region of the exhaust heat recovery apparatus to direct exhaust gas through the first flow passage or the second flow passage.

  8. PLAG1 deficiency impairs spermatogenesis and sperm motility in mice.

    Science.gov (United States)

    Juma, Almas R; Grommen, Sylvia V H; O'Bryan, Moira K; O'Connor, Anne E; Merriner, D Jo; Hall, Nathan E; Doyle, Stephen R; Damdimopoulou, Pauliina E; Barriga, Daniel; Hart, Adam H; Van de Ven, Wim J M; De Groef, Bert

    2017-07-13

    Deficiency in pleomorphic adenoma gene 1 (PLAG1) leads to reduced fertility in male mice, but the mechanism by which PLAG1 contributes to reproduction is unknown. To investigate the involvement of PLAG1 in testicular function, we determined (i) the spatial distribution of PLAG1 in the testis using X-gal staining; (ii) transcriptomic consequences of PLAG1 deficiency in knock-out and heterozygous mice compared to wild-type mice using RNA-seq; and (iii) morphological and functional consequences of PLAG1 deficiency by determining testicular histology, daily sperm production and sperm motility in knock-out and wild-type mice. PLAG1 was sparsely expressed in germ cells and in Sertoli cells. Genes known to be involved in spermatogenesis were downregulated in the testes of knock-out mice, as well as Hsd17b3, which encodes a key enzyme in androgen biosynthesis. In the absence of Plag1, a number of genes involved in immune processes and epididymis-specific genes were upregulated in the testes. Finally, loss of PLAG1 resulted in significantly lowered daily sperm production, in reduced sperm motility, and in several animals, in sloughing of the germinal epithelium. Our results demonstrate that the subfertility seen in male PLAG1-deficient mice is, at least in part, the result of significantly reduced sperm output and sperm motility.

  9. Effects of Piper hispidinervum on spermatogenesis and histochemistry of ovarioles of Spodoptera frugiperda.

    Science.gov (United States)

    Alves, T J S; Cruz, G S; Wanderley-Teixeira, V; Teixeira, A A C; Oliveira, J V; Correia, A A; Câmara, C A G; Cunha, F M

    2014-05-01

    The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3(rd) instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest.

  10. Profiling of androgen response in rainbow trout pubertal testis: relevance to male gonad development and spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Antoine D Rolland

    Full Text Available The capacity of testicular somatic cells to promote and sustain germ cell differentiation is largely regulated by sexual steroids and notably androgens. In fish species the importance of androgens is emphasized by their ability to induce sex reversal of the developing fries and to trigger spermatogenesis. Here we studied the influence of androgens on testicular gene expression in trout testis using microarrays. Following treatment of immature males with physiological doses of testosterone or 11-ketotestosterone, 418 genes that exhibit changes in expression were identified. Interestingly, the activity of testosterone appeared stronger than that of 11-ketotestosterone. Expression profiles of responsive genes throughout testis development and in isolated germ cells confirmed androgens to mainly affect gene expression in somatic cells. Furthermore, specific clusters of genes that exhibit regulation coincidently with changes in the natural circulating levels of androgens during the reproductive cycle were highlighted, reinforcing the physiological significance of these data. Among somatic genes, a phylogenetic footprinting study identified putative androgen response elements within the proximal promoter regions of 42 potential direct androgen target genes. Finally, androgens were also found to alter the germ line towards meiotic expression profiles, supporting the hypothesis of a role for the somatic responsive genes in driving germ cell fate. This study significantly increases our understanding of molecular pathways regulated by androgens in vertebrates. The highly cyclic testicular development in trout together with functions associated with regulated genes reveal potential mechanisms for androgen actions in tubule formation, steroid production, germ cell development and sperm secretion.

  11. Functions of TAM RTKs in regulating spermatogenesis and male fertility in mice.

    Science.gov (United States)

    Chen, Yongmei; Wang, Huizhen; Qi, Nan; Wu, Hui; Xiong, Weipeng; Ma, Jing; Lu, Qingxian; Han, Daishu

    2009-10-01

    Mice lacking TYRO3, AXL and MER (TAM) receptor tyrosine kinases (RTKs) are male sterile. The mechanism of TAM RTKs in regulating male fertility remains unknown. In this study, we analyzed in more detail the testicular phenotype of TAM triple mutant (TAM(-/-)) mice with an effort to understand the mechanism. We demonstrate that the three TAM RTKs cooperatively regulate male fertility, and MER appears to be more important than AXL and TYRO3. TAM(-/-) testes showed a progressive loss of germ cells from elongated spermatids to spermatogonia. Young adult TAM(-/-) mice exhibited oligo-astheno-teratozoospermia and various morphological malformations of sperm cells. As the mice aged, the germ cells were eventually depleted from the seminiferous tubules. Furthermore, we found that TAM(-/-) Sertoli cells have an impaired phagocytic activity and a large number of differentially expressed genes compared to wild-type controls. By contrast, the function of Leydig cells was not apparently affected by the mutation of TAM RTKs. Therefore, we conclude that the suboptimal function of Sertoli cells leads to the impaired spermatogenesis in TAM(-/-) mice. The results provide novel insight into the mechanism of TAM RTKs in regulating male fertility.

  12. Impact of melatonin supplementation in the rat spermatogenesis subjected to forced swimming exercise.

    Science.gov (United States)

    Moayeri, A; Mokhtari, T; Hedayatpour, A; Abbaszadeh, H-A; Mohammadpour, S; Ramezanikhah, H; Shokri, S

    2018-04-01

    Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8 weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters. © 2017 Blackwell Verlag GmbH.

  13. Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

    International Nuclear Information System (INIS)

    Wang, Yandi; Zhao, Yong; Yu, Shuai; Feng, Yanni; Zhang, Hongfu; Kou, Xin; Chu, Meiqiang; Cui, Liantao; Li, Lan; Zhang, Pengfei; Shen, Wei; Min, Lingjiang

    2016-01-01

    Although it is well known that cysteamine is a potent chemical for treating many diseases including cystinosis and it has many adverse effects, the effect of cysteamine on spermatogenesis is as yet unknown. Therefore the objective of this investigation was to explore the effects of cysteamine on spermatogenesis and the underlying mechanisms. Sheep were treated with vehicle control, 10 mg/kg or 20 mg/kg cysteamine for six months. After that, the semen samples were collected to determine the spermatozoa motility by computer-assisted sperm assay method. Blood samples were collected to detect the levels of hormones and the activity of enzymes. Spermatozoa and testis samples were collected to study the mechanism of cysteamine's actions. It was found that the effects of cysteamine on spermatogenesis were dose dependent. A low dose (10 mg/kg) cysteamine treatment increased ovine spermatozoa motility; however, a higher dose (20 mg/kg) decreased both spermatozoa concentration and motility. This decrease might be due to a reduction in steroid hormone production by the testis, a reduction in energy in the testis and spermatozoa, a disruption in the blood-testis barrier, or a breakdown in the vital signaling pathways involved in spermatogenesis. The inhibitory effects of cysteamine on sheep spermatogenesis may be used to model its effects on young male patients with cystinosis or other diseases that are treated with this drug. Further studies on spermatogenesis that focus on patients treated with cysteamine during the peripubertal stage are warranted. - Highlights: • Dose dependent effects of cysteamine on spermatogenesis • A low dose (10 mg/kg) increased spermatozoa motility. • A higher dose (20 mg/kg) decreased both concentration and motility of spermatozoa. • Disruption in the blood-testis barrier caused reduction in concentration and motility.

  14. Regulation of steroid hormones and energy status with cysteamine and its effect on spermatogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yandi [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhao, Yong [Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109 (China); Yu, Shuai; Feng, Yanni [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhang, Hongfu [State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing (China); Kou, Xin [Shouguang Hongde Farmer Co., Weifang 262700 (China); Chu, Meiqiang; Cui, Liantao; Li, Lan [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Zhang, Pengfei [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109 (China); Shen, Wei [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China); Min, Lingjiang, E-mail: mlj020963@hotmail.com [College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109 (China); Key Laboratory of Animal Reproduction and Germplasm Enhancement, Universities of Shandong, Qingdao 266109 (China)

    2016-12-15

    Although it is well known that cysteamine is a potent chemical for treating many diseases including cystinosis and it has many adverse effects, the effect of cysteamine on spermatogenesis is as yet unknown. Therefore the objective of this investigation was to explore the effects of cysteamine on spermatogenesis and the underlying mechanisms. Sheep were treated with vehicle control, 10 mg/kg or 20 mg/kg cysteamine for six months. After that, the semen samples were collected to determine the spermatozoa motility by computer-assisted sperm assay method. Blood samples were collected to detect the levels of hormones and the activity of enzymes. Spermatozoa and testis samples were collected to study the mechanism of cysteamine's actions. It was found that the effects of cysteamine on spermatogenesis were dose dependent. A low dose (10 mg/kg) cysteamine treatment increased ovine spermatozoa motility; however, a higher dose (20 mg/kg) decreased both spermatozoa concentration and motility. This decrease might be due to a reduction in steroid hormone production by the testis, a reduction in energy in the testis and spermatozoa, a disruption in the blood-testis barrier, or a breakdown in the vital signaling pathways involved in spermatogenesis. The inhibitory effects of cysteamine on sheep spermatogenesis may be used to model its effects on young male patients with cystinosis or other diseases that are treated with this drug. Further studies on spermatogenesis that focus on patients treated with cysteamine during the peripubertal stage are warranted. - Highlights: • Dose dependent effects of cysteamine on spermatogenesis • A low dose (10 mg/kg) increased spermatozoa motility. • A higher dose (20 mg/kg) decreased both concentration and motility of spermatozoa. • Disruption in the blood-testis barrier caused reduction in concentration and motility.

  15. The outcome of ART in males with impaired spermatogenesis

    Directory of Open Access Journals (Sweden)

    V S Mangoli

    2008-01-01

    Full Text Available Aims: This study was conducted to evaluate the outcomes of assisted reproductive technology (ART procedures, viz., intrauterine insemination (IUI, in vitro fertilization (IVF and intracytoplasmic sperm injection (ICSI in males with impaired spermatogenesis. Settings and Design: The subjects of the study were infertile couples who were undergoing ART treatment due to male factor indications. The project was designed to correlate the outcome of the ART treatment and its efficacy in different study groups. Methods: Males were grouped as: 1. oligozoospermia (n = 153, 2. asthenoteratozoospermia (n = 158, 3. obstructive azoospermia (n = 110 and 4. nonobstructive azoospermia (n = 58. Patients from groups 1 and 2 were considered for IUI, IVF and ICSI. Those from group 3 were considered for IVF and ICSI and the 4th group underwent only ICSI treatment. Results: Oligozoospermia showed lower pregnancy rates with IUI than with both IVF and ICSI. An average minimum native and postharvest count was obtained to get an acceptable IUI outcome. Asthenoteratozoospermia had the lowest pregnancy rate with IUI as compared to IVF, whereas ICSI showed significantly higher pregnancy rates in this group. Obstructive azoospermia showed significant improvement with ICSI over IVF. In nonobstructive azoospermia, ICSI resulted in a 27.58% pregnancy rate. Conclusion: The IUI outcome was impressive though less effective whereas there was no difference between the IVF and ICSI outcomes in oligozoospermia. In asthenoteratozoospermia, ICSI showed a significant advantage over IUI and IVF, with IUI resulting in poor outcome in this group. In obstructive azoospermia, ICSI had a distinct advantage over IVF whereas in nonobstructive azoospermia, ICSI, the only option, was found to be effective and helpful in achieving an acceptable pregnancy rate.

  16. Restoration and maintenance of spermatogenesis by HCG therapy in patients with hypothalamo-hypophyseal damage.

    Science.gov (United States)

    Levalle, O; Bokser, L; Pacenza, N; Aszenmil, G; Fiszlejder, L; Chervin, A; Guitelman, A

    1984-01-01

    Both gonadotropins are necessary to induce spermatogenesis in man and to recover hypophysectomized males. The patients who suffer from tumoral or traumatic hypothalamo-hypophyseal lesion use to have low endogenous gonadotropins (opposite to hypophysectomized patients), which can produce a minor involution of spermatogenesis. Three patients with postpubertal hypogonadotropic hypogonadism and oligozoospermia were studied. Two of them were operated on for chromophobous adenoma of pituitary, and the other patient had traumatic hypothalamo-hypophyseal lesion. The three patients were treated with 5000 IU HCG/week, associated with testosterone enanthate, in two cases and with bromocryptine in the remaining one. All the patients had normalized spermiogram, but when HCG was interrupted, the sperm count regressed to pretreatment levels in spite of the maintenance of treatment with testosterone or bromocryptine. Minimal amounts of FSH together the testosterone supplied by Leydig cell under the HCG stimulus, are able to recover and maintain the spermatogenesis in these patients.

  17. Effect of previous exhaustive exercise on metabolism and fatigue development during intense exercise in humans

    DEFF Research Database (Denmark)

    Iaia, F. M.; Perez-Gomez, J.; Nordsborg, Nikolai

    2010-01-01

    The present study examined how metabolic response and work capacity are affected by previous exhaustive exercise. Seven subjects performed an exhaustive cycle exercise ( approximately 130%-max; EX2) after warm-up (CON) and 2 min after an exhaustive bout at a very high (VH; approximately 30 s), high...

  18. Advanced exhaust nozzle technology

    Energy Technology Data Exchange (ETDEWEB)

    Glidewell, R J; Warburton, R E

    1981-01-01

    Recent developments in turbine engine exhaust nozzle technology include nonaxisymmetric nozzles, thrust reversing, and thrust vectoring. Trade studies have been performed to determine the impact of these developments on the thrust-to-weight ratio and specific fuel consumption of an advanced high performance, augmented turbofan engine. Results are presented in a manner which provides an understanding of the sources and magnitudes of differences in the basic elements of nozzle internal performance and weight as they relate to conventional, axisymmetric nozzle technology. Conclusions are presented and recommendations are made with regard to future directions of advanced development and demonstration. 5 refs.

  19. Catalytic exhaust control

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, H

    1973-09-01

    Recent achievements and problems in the development of exhaust control devices in the USA are reviewed. To meet the 1976 emission standards, catalytic systems for the oxidation of carbon monoxide and hydrocarbons and for the reduction of nitrogen oxides to nitrogen and water are needed. While oxidizing catalysts using platinum, palladium, copper, vanadium, and chromium appplied on alumina or ceramic materials are more or less effective in emission control, there are no catalytic devices for the reduction of nitrogen oxides with the required useful life of 25,000 to 50,000 miles as yet available. In the case of platinum catalysts on monolithic supports, the operating temperature of 650 to 750/sup 0/C as required for the oxidation process may cause inactivation of the catalysts and fusion of the support material. The oxidation of CO and hydrocarbons is inhibited by high concentrations of CO, nitric oxide, and hydrocarbons. The use of catalytic converters requires the use of lead-free or low-lead gasoline. The nitrogen oxides conversion efficiency is considerably influenced by the oxygen-to-CO ratio of the exhaust gas, which makes limitation of this ratio necessary.

  20. Neonatal androgenization of hypogonadal (hpg male mice does not abolish estradiol-induced FSH production and spermatogenesis

    Directory of Open Access Journals (Sweden)

    Kerr Jeffrey B

    2005-09-01

    Full Text Available Abstract Background Testicular development is arrested in the hypogonadal (hpg mouse due to a congenital deficiency in hypothalamic gonadotropin-releasing hormone (GnRH synthesis. Chronic treatment of male hpg mice with estradiol induces FSH synthesis and secretion, and causes testicular maturation and qualitatively normal spermatogenesis. As estradiol negative feedback normally inhibits FSH production in the male, this study tested whether this paradoxical response to estradiol in the male hpg mouse might be due to inadequate masculinisation or incomplete defeminization in the neonatal period. Previous studies have demonstrated that treatment of hpg mice with testosterone propionate in the immediate neonatal period is necessary to allow full reproductive behaviors to be expressed following suitable endocrine stimulation at adult ages. Methods Hpg mice were treated with 100 μg testosterone propionate or vehicle on postnatal day 2. At 35 days of age, subgroups of these mice were treated with silastic implants containing estradiol or cholesterol. Reproductive behavior was scored in tests with steroid-primed female mice, then testicular development was assessed histologically, and measures of pituitary FSH content made at 85 days of age. Results The neonatal testosterone propionate treatment successfully defeminized female litter mates, as revealed by impaired vaginal opening and deficiencies in lordosis behavior, and it allowed appropriate male reproductive behavior to be expressed in a proportion of the hpg males when tested at an adult age. However, neonatal androgen supplementation did not block or even reduce the subsequent actions of estradiol in increasing pituitary FSH content, nor did it affect the ability of estradiol to induce qualitatively normal spermatogenesis. Conclusion The ability of the hpg male to show a "female" neuroendocrine response to estradiol is not a result of inadequate androgenization during neonatal development, and

  1. Recovery of spermatogenesis following testosterone replacement therapy or anabolic-androgenic steroid use

    Directory of Open Access Journals (Sweden)

    J Abram McBride

    2016-01-01

    Full Text Available The use of testosterone replacement therapy (TRT for hypogonadism continues to rise, particularly in younger men who may wish to remain fertile. Concurrently, awareness of a more pervasive use of anabolic-androgenic steroids (AAS within the general population has been appreciated. Both TRT and AAS can suppress the hypothalamic-pituitary-gonadal (HPG axis resulting in diminution of spermatogenesis. Therefore, it is important that clinicians recognize previous TRT or AAS use in patients presenting for infertility treatment. Cessation of TRT or AAS use may result in spontaneous recovery of normal spermatogenesis in a reasonable number of patients if allowed sufficient time for recovery. However, some patients may not recover normal spermatogenesis or tolerate waiting for spontaneous recovery. In such cases, clinicians must be aware of the pathophysiologic derangements of the HPG axis related to TRT or AAS use and the pharmacologic agents available to reverse them. The available agents include injectable gonadotropins, selective estrogen receptor modulators, and aromatase inhibitors, but their off-label use is poorly described in the literature, potentially creating a knowledge gap for the clinician. Reviewing their use clinically for the treatment of hypogonadotropic hypogonadism and other HPG axis abnormalities can familiarize the clinician with the manner in which they can be used to recover spermatogenesis after TRT or AAS use.

  2. Spermatogenesis-specific features of the meiotic program in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Diane C Shakes

    2009-08-01

    Full Text Available In most sexually reproducing organisms, the fundamental process of meiosis is implemented concurrently with two differentiation programs that occur at different rates and generate distinct cell types, sperm and oocytes. However, little is known about how the meiotic program is influenced by such contrasting developmental programs. Here we present a detailed timeline of late meiotic prophase during spermatogenesis in Caenorhabditis elegans using cytological and molecular landmarks to interrelate changes in chromosome dynamics with germ cell cellularization, spindle formation, and cell cycle transitions. This analysis expands our understanding C. elegans spermatogenesis, as it identifies multiple spermatogenesis-specific features of the meiotic program and provides a framework for comparative studies. Post-pachytene chromatin of spermatocytes is distinct from that of oocytes in both composition and morphology. Strikingly, C. elegans spermatogenesis includes a previously undescribed karyosome stage, a common but poorly understood feature of meiosis in many organisms. We find that karyosome formation, in which chromosomes form a constricted mass within an intact nuclear envelope, follows desynapsis, involves a global down-regulation of transcription, and may support the sequential activation of multiple kinases that prepare spermatocytes for meiotic divisions. In spermatocytes, the presence of centrioles alters both the relative timing of meiotic spindle assembly and its ultimate structure. These microtubule differences are accompanied by differences in kinetochores, which connect microtubules to chromosomes. The sperm-specific features of meiosis revealed here illuminate how the underlying molecular machinery required for meiosis is differentially regulated in each sex.

  3. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

    Directory of Open Access Journals (Sweden)

    Jennifer Ferguson

    Full Text Available In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  4. In vitro maintenance of spermatogenesis in Xenopus laevis testis explants cultured in serum-free media

    International Nuclear Information System (INIS)

    Risley, M.S.; Miller, A.; Bumcrot, D.A.

    1987-01-01

    Spermatogenesis has been maintained for extended periods in Xenopus laevis testis explants cultured in serum-free media supplemented with bovine serum albumin, insulin, transferrin, follicle-stimulating hormone, dihydrotestosterone, testosterone, retinol, ascorbate, and tocopherol. The organization of the testis fragments was maintained for 28 days, and all stages of development were present throughout the culture period. 3 H-Thymidine-labeled secondary (Type B) spermatogonia developed in 28 days into spermatids at the acrosomal vesicle stage whereas labeled zygotene spermatocytes became mature spermatids in 28 days. Spermatogonial proliferation also continued in vitro for 28 days. Germ cell differentiation was not dependent upon exogenous testosterone, ascorbate, or tocopherol since 3 H-labeled spermatogonia became mature spermatids in testes cultured 35 days in media lacking these supplements. Autoradiography demonstrated that 55% of the luminal sperm present in explants cultured 10 days had differentiated in vitro. Sperm from testes cultured 10-35 days were similar to sperm from freshly dissected testes with regard to motility and fecundity, and eggs fertilized with sperm from explant cultures developed normally into swimming tadpoles. The results demonstrate the feasibility of maintaining vertebrate spermatogenesis in culture and suggest that in vitro analysis of Xenopus spermatogenesis using defined media may provide important insights into the evolution of regulatory mechanisms in spermatogenesis

  5. Spermatogenesis is accelerated in the immature Djungarian and Chinese hamster and rat

    NARCIS (Netherlands)

    van Haaster, L. H.; de rooij, D. G.

    1993-01-01

    The rate of progression of spermatogenesis was studied in immature Djungarian and Chinese hamsters and Wistar rats by scoring the most advanced cell types present at various ages after birth. From 15 days of age onward, the most advanced cell types in the Djungarian hamsters were formed at a rate

  6. The effect of para-nonylphenol on Japanese eel (Anguilla japonica) spermatogenesis in vitro

    International Nuclear Information System (INIS)

    Miura, C.; Takahashi, N.; Michino, F.; Miura, T.

    2005-01-01

    Endocrine disrupters have been recognized to interfere with endocrine systems that regulate reproduction, for example, by mimicking or inhibiting the action of endogenous sex steroid hormones including estradiol-17β (E2). In the present study, we examined the effect of an endocrine disrupter, para-nonylphenol (p-NP) on spermatogenesis, and compared it with the action of E2, using an eel testicular organ culture system. p-NP alone stimulated early spermatogonial renewal in the same manner as E2. Neither induced further progress in spermatogenesis. In the presence of 11-ketotestosterone (11-KT), the major androgen in teleosts, p-NP did not prevent the 11-KT-induced progress in spermatogenesis. However, this treatment enlarged the Sertoli cells. Electron microscopic observation revealed that enlarged Sertoli cells contained well-developed organelles. Moreover, the proportion of germ cells appeared to have decreased as a result of Sertoli cell hypertrophy. These results clearly show that p-NP has an effect on Sertoli cells in the presence of an androgen (11-KT), potentially disturbing 11-KT-induced spermatogenesis

  7. Analysis of cell-type-specific gene expression during mouse spermatogenesis

    DEFF Research Database (Denmark)

    Almstrup, Kristian; Nielsen, John E; Hansen, Martin Asser

    2004-01-01

    In rodents, changes in gene expression during spermatogenesis can be monitored by sampling testis from each day during postnatal development. However, changes in gene expression at the tissue level can reflect changes in the concentration of an mRNA in a specific cell type, changes in volume of s...

  8. Hormonal control of spermatogenesis: expression of FSJH receptor and androgen receptor genes

    NARCIS (Netherlands)

    L.J. Blok (Leen)

    1992-01-01

    textabstractFSH and testosterone are the main hormonal regulators of spermatogenesis. The actions of androgens and FSH are mediated by their respective receptors. Receptor gene expression (mRNA and protein). is an important determinant of hormone action. Biochemical aspects of the regulation of

  9. Automotive Fuel and Exhaust Systems.

    Science.gov (United States)

    Irby, James F.; And Others

    Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

  10. High temperature sensors for exhaust diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Svenningstorp, Henrik

    2000-07-01

    One of the largest problems that we will have to deal with on this planet this millennium is to stop the pollution of our environment. In many of the ongoing works to reduce toxic emissions, gas sensors capable of enduring rough environments and high temperatures, would be a great tool. The different applications where sensors like this would be useful vary between everything from online measurement in the paper industry and food industry to measurement in the exhaust pipe of a car. In my project we have tested Schottky diodes and MlSiCFET sensor as gas sensors operating at high temperatures. The measurement condition in the exhaust pipe of a car is extremely tough, not only is the temperature high and the different gases quite harmful, there are also a lot of particles that can affect the sensors in an undesirable way. In my project we have been testing Schottky diodes and MlSiCFET sensors based on SiC as high temperature sensors, both in the laboratory with simulated exhaust and after a real engine. In this thesis we conclude that these sensors can work in the hostile environment of an engines exhaust. It is shown that when measuring in a gas mixture with a fixed I below one, where the I-value is controlled by the O{sub 2} concentration, a sensor with a catalytic gate metal as sensitive material respond more to the increased O{sub 2} concentration than the increased HC concentration when varying the two correspondingly. A number of different sensors have been tested in simulated exhaust towards NO{sub x}. It was shown that resistivity changes in the thin gate metal influenced the gas response. Tests have been performed where sensors were a part of a SCR system with promising results concerning NH{sub 3} sensitivity. With a working temperature of 300 deg C there is no contamination of the metal surface.

  11. Dioxin-induced changes in epididymal sperm count and spermatogenesis Mudanças induzidas por dioxina na contagem epididimal de esperma e espermatogênese

    Directory of Open Access Journals (Sweden)

    Warren G. Foster

    2011-06-01

    Full Text Available A single in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD on gestation day 15 decreased epididymal sperm count in adult rats and thus was used to establish a tolerable daily intake for TCDD. However, several laboratories have been unable to replicate these findings. Moreover, conflicting reports of TCDD effects on daily sperm production suggest that spermatogenesis may not be as sensitive to the adverse effects of TCDD as previously thought. We performed a PubMed search using relevant search terms linking dioxin exposure with adverse effects on reproduction and spermatogenesis. Developmental exposure to TCDD is consistently linked with decreased cauda epididymal sperm counts in animal studies, although at higher dose levels than those used in some earlier studies. However, the evidence linking in utero TCDD exposure and spermatogenesis is not convincing. Animal studies provide clear evidence of an adverse effect of in utero TCDD exposure on epididymal sperm count but do not support the conclusion that spermatogenesis is adversely affected. The mechanisms underlying decreased epididymal sperm count are unknown; however, we postulate that epididymal function is the key target for the adverse effects of TCDD.Uma única exposição in utero a 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD no 15º dia de gestação diminuiu a contagem de esperma epididimal em ratos adultos e por isso foi utilizada para estabelecer uma dosagem diária tolerável para TCDD. No entanto, diversos laboratórios não conseguiram reproduzir esses resultados. Além disso, relatórios conflitantes dos efeitos de TCDD na produção diária de esperma sugere que espermatogênese pode não ser tão sensível aos efeitos adversos do TCDD como antes se pensava. Foi feita uma pesquisa no PubMed usando termos de pesquisa relevantes, relacionados à exposição à dioxina com efeitos adversos na reprodução e na espermatogênese. Exposição em desenvolvimento ao TCDD

  12. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R C; Anderson, M R; Miake-Lye, R C; Kolb, C E [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A A; Buriko, Y I [Scientific Research Center ` Ecolen` , Moscow (Russian Federation)

    1998-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  13. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  14. Differential effects of genetic - and diet - induced obesity on fertility, spermatogenesis and sperm epigenome in adult male rats

    Directory of Open Access Journals (Sweden)

    Sharvari Deshpande

    2017-10-01

    Full Text Available Obesity is a global health issue affecting millions of people of different age groups. The incidence of male obesity induced infertility is rising in couples undergoing ARTs suggesting that obesity is an established risk factor for male infertility. Recent studies demonstrate that paternal diet induced obesity could induce epigenetic disturbances in offspring. Obesity is a multifactorial disorder with predominantly genetic or environmental causes. No studies have compared the effect of genetic and diet induced obesity on male reproduction. The present study aims to delineate effects of obesity on male fertility, spermatogenesis and sperm epigenome using two rat models: genetically induced obese (GIO – WNIN/OB and diet induced obese (DIO – High fat diet. Body weights were similar in both groups, but, differential effects on hormonal profiles were observed. Fertility assessment showed decreased litter size mainly due to increased pre- and post-implantation loss in DIO group. However, GIO group were infertile due to decrease in libido. We observed a decrease in sperm counts in GIO group but not in DIO group despite the body weights being similar in both the groups. Flow cytometry and cell type specific marker expression studies in testis revealed that both DIO and GIO affect mitosis and differentiation process by increasing spermatogonial proliferation. In DIO group, no effect was observed on meiosis whereas in GIO group, we observed an effect on meiosis. Spermiogenesis process was affected in both the groups. In order to study the effect of genetic and diet induced obesity on different aspects of spermatogenesis, we performed qRT-PCR to study expression of genes involved in spermatocyte progression, spermiogenesis process, reproductive hormone receptors and leptin signaling in testis. Since epigenetic mechanisms are susceptible to environmental and genetic changes, we analyzed the methylation status of Igf2-H19 DMR in spermatozoa of both the

  15. Estrogen receptor alpha localization in the testes of men with normal spermatogenesis Estrogen receptor alpha localization in the testes of men with normal spermatogenesis

    OpenAIRE

    Eliza Filipiak; Dagmara Suliborska; Maria Laszczynska; Renata Walczak-Jedrzejowska; Elzbieta Oszukowska; Katarzyna Marchlewska; Krzysztof Kula; Jolanta Slowikowska-Hilczer

    2012-01-01

    It is known that estrogens act on the male reproductive tract by binding to estrogen receptors (ER) a and
    b. However, studies on ER localization in the human testis are discordant. The aim of this study was to investigate
    the localization of ERa in the testes of adult men with normal spermatogenesis. Semen analysis of ten adult men
    revealed azoospermia. FSH, LH and testosterone serum concentrations were within normal values, and the volume
    of the te...

  16. Genetic, structural, and chemical insights into the dual function of GRASP55 in germ cell Golgi remodeling and JAM-C polarized localization during spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Amandine Cartier-Michaud

    2017-06-01

    Full Text Available Spermatogenesis is a dynamic process that is regulated by adhesive interactions between germ and Sertoli cells. Germ cells express the Junctional Adhesion Molecule-C (JAM-C, encoded by Jam3, which localizes to germ/Sertoli cell contacts. JAM-C is involved in germ cell polarity and acrosome formation. Using a proteomic approach, we demonstrated that JAM-C interacted with the Golgi reassembly stacking protein of 55 kDa (GRASP55, encoded by Gorasp2 in developing germ cells. Generation and study of Gorasp2-/- mice revealed that knock-out mice suffered from spermatogenesis defects. Acrosome formation and polarized localization of JAM-C in spermatids were altered in Gorasp2-/- mice. In addition, Golgi morphology of spermatocytes was disturbed in Gorasp2-/- mice. Crystal structures of GRASP55 in complex with JAM-C or JAM-B revealed that GRASP55 interacted via PDZ-mediated interactions with JAMs and induced a conformational change in GRASP55 with respect of its free conformation. An in silico pharmacophore approach identified a chemical compound called Graspin that inhibited PDZ-mediated interactions of GRASP55 with JAMs. Treatment of mice with Graspin hampered the polarized localization of JAM-C in spermatids, induced the premature release of spermatids and affected the Golgi morphology of meiotic spermatocytes.

  17. Device for purifying exhaust gas

    International Nuclear Information System (INIS)

    Makita, Kiyoshi.

    1973-01-01

    Purpose: To ensure the reliability in collection of krypton even on accident in liquidizing distillation tower. Constitution: Exhaust gas flows through active carbon adsorption tower where short half-life rare gas in exhaust gas is separated by adsorption, then through heat exchanger, then continuous distillation tower where krypton 85 is separated, then through batch distillation tower where krypton 85 is condensed, and then flows into storing cylinder. On accident in liquidizing distillation tower, at the first period exhaust gas flows through series connected active carbon adsorption tower, krypton 85 adsorbed in adsorption tower being transferred to cooling type adsorption tower, at the next period exhaust gas flows through tower, krypton 85 adsorbed in adsorption tower being transferred to tower. (M. K.)

  18. Studies on the role of gibberellins in the regulation of spermatogenesis in Chara vulgaris L.

    Directory of Open Access Journals (Sweden)

    Maria Kwiatkowska

    2014-01-01

    Full Text Available Antheridia from isolated nodes of Chara vulgaris, developing in the presence of either AMO-1618 or GA3, were studied. AMO-1618 which lowers the level of endogenous gibberellins causes a significant, proportional to the concentration, reduction in: 1 the number of antheridial filaments formed in antheridia, 2 spermatid number within a filament, as a result of eliminating one mitotic division at the first stage of spermatogenesis. Exogenous GA3 at the concentration 10-5 M evokes opposite effect i.e. increase in the number of antheridial filaments and increase in the number of spermatids within filament. Total number of spermatids within an antheridium decreases under the influence of 10-4M AMO-1618 three times in comparison with the control, whereas it increases twice following 10-5M GA3 treatment. It has been suggested that the normal course of spermatogenesis requires precisely determined level of endogenous gibberellins.

  19. Honey improves spermatogenesis and hormone secretion in testicular ischaemia-reperfusion-induced injury in rats.

    Science.gov (United States)

    Gholami, M; Abbaszadeh, A; Khanipour Khayat, Z; Anbari, K; Baharvand, P; Gharravi, A M

    2018-02-01

    This study was conducted to survey the protective effect of pre-treatment with Persian honey during post-ischaemia reperfusion on ischaemia-reperfusion (IR)-induced testis injury. Animals were divided into four groups of IR, honey + ischaemia- reperfusion (HIR), vitamin C + ischaemia- reperfusion (VIR) and carbohydrates + ischaemia- reperfusion (CIR). The testes were examined for spermatogenesis index. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed. Total serum concentration of FSH, LH and testosterone was measured using ELISA. All data were expressed as mean ± SD in each group, and significance was set at p ≤ .05. Spermatogenesis index was significant in the HIR group (p honey decreases the cellular damage and apoptosis during testicular I/R injury, with significant protective effects on reproductive hormone production. © 2017 Blackwell Verlag GmbH.

  20. Spermatogenesis in dogs after termination of the three-year exposure to γ-radiation

    International Nuclear Information System (INIS)

    Fedorova, N.L.; Markelov, B.A.

    1979-01-01

    A study was made of spermatogenesis of 15 dogs after termination of the three-year exposure to γ-radiation at dose rates of 0.34 and 0.17 rad/day plus dosages of 8 and 42 rad given 3 times a year (cumulative doses 375, 360 and 570 rad, respectively). A partial recovery of spermatogenesis was resistered. During the first 1-1.5 year following irradiation normalization was more intensive in males with most harmful lesions (cumulative dose of 570 rad). Subsequently (3-6 years), the rate of recovery slowed and the process of production of germ cells was stabilized at a lower level. Recovery of dogs received cumulative doses of 375 and 360 rad was less intensive

  1. Testis-Specific Histone Variant H3t Gene Is Essential for Entry into Spermatogenesis

    Directory of Open Access Journals (Sweden)

    Jun Ueda

    2017-01-01

    Full Text Available Cellular differentiation is associated with dynamic chromatin remodeling in establishing a cell-type-specific epigenomic landscape. Here, we find that mouse testis-specific and replication-dependent histone H3 variant H3t is essential for very early stages of spermatogenesis. H3t gene deficiency leads to azoospermia because of the loss of haploid germ cells. When differentiating spermatogonia emerge in normal spermatogenesis, H3t appears and replaces the canonical H3 proteins. Structural and biochemical analyses reveal that H3t-containing nucleosomes are more flexible than the canonical nucleosomes. Thus, by incorporating H3t into the genome during spermatogonial differentiation, male germ cells are able to enter meiosis and beyond.

  2. Effects of acute gamma-irradiation on spermatogenesis as revealed by flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, U; Schumann, J; Goehde, W [Muenster Univ. (Germany, F.R.)

    1980-01-01

    Mice irradiated with doses ranging from 0.1 to 15 Gy using a /sup 60/Co-source and controls were killed at intervals varying from 2 to 35 days after irradiation. The DNA content of the testicular cells in single cell suspensions was measured with the pulse cytophotometer to determine the frequencies of the different stages in the spermatogenesis. The relative amount of S-phase and 4c-cells was reduced initially but increased subsequently to hypernormal values. A decrease of 2c-cells indicated a higher cell-kill of diploid spermatogonia. Gamma ray-induced spermatids with abnormal DNA-values (diploid sperm) were identified. The results suggest that the spermatogenesis can be analysed with flow cytometry and used as a biologic dosimeter even for small doses of ionizing radiation.

  3. Effects of acute gamma-irradiation on spermatogenesis as revealed by flow cytometry

    International Nuclear Information System (INIS)

    Hacker, U.; Schumann, J.; Goehde, W.

    1980-01-01

    Mice irradiated with doses ranging from 0.1 to 15 Gy using a 60 Co-source and controls were killed at intervals varying from 2 to 35 days after irradiation. The DNA content of the testicular cells in single cell suspensions was measured with the pulse cytophotometer to determine the frequencies of the different stages in the spermatogenesis. The relative amount of S-phase and 4c-cells was reduced initially but increased subsequently to hypernormal values. A decrease of 2c-cells indicated a higher cell-kill of diploid spermatogonia. Gamma ray-induced spermatids with abnormal DNA-values (diploid sperm) were identified. The results suggest that the spermatogenesis can be analysed with flow cytometry and used as a biologic dosimeter even for small doses of ionizing radiation. (Auth.)

  4. Computer-assisted Biology Learning Materials: Designing and Developing an Interactive CD on Spermatogenesis

    Science.gov (United States)

    Haviz, M.

    2018-04-01

    The purpose of this article is to design and develop an interactive CD on spermatogenesis. This is a research and development. Procedure of development is making an outline of media program, making flowchart, making story board, gathering of materials, programming and finishing. The quantitative data obtained were analyzed by descriptive statistics. Qualitative data obtained were analyzed with Miles and Huberman techniques. The instrument used is a validation sheet. The result of CD design with a Macro flash MX program shows there are 17 slides generated. This prototype obtained a valid value after a self-review technique with many revisions, especially on sound and programming. This finding suggests that process-oriented spermatogenesis can be audio-visualized into a more comprehensive form of learning media. But this interactive CD product needs further testing to determine consistency and resistance to revisions.

  5. [Spermatogenesis of pulsatile gonadotropin-releasing hormone infusion versus gonadotropin therapy in male idiopathic hypogonadotropic hypogonadism].

    Science.gov (United States)

    Huang, Bingkun; Mao, Jiangfeng; Xu, Hongli; Wang, Xi; Liu, Zhaoxiang; Nie, Min; Wu, Xueyan

    2015-05-26

    To compare the efficacies of pulsatile gonadotropin-releasing hormone (GnRH) versus human chorionic gonadotropin/human menopausal gonadotropin (HCG/HMG) for spermatogenesis in male idiopathic hypogonadotropic hypogonadism (IHH). For this retrospective study, a total of 92 male IHH outpatients from May 2010 to October 2014 were recruited and categorized into GnRH (n = 40) and HCG/HMG (n = 52) groups. Each subject selected one specific therapy voluntarily. The gonadotropin levels were measured in the first week and monthly post-treatment in GnRH group. And serum total testosterone (TT), testicular volume (TV) and rate of spermatogenesis were observed monthly post-treatment in two groups. Spermatogenesis, TT and TV were compared between two groups. All IHH patients were treated for over 3 months. The median follow-up periods in GnRH and HCG/HMG groups was 8.2 (3.0-18.4) and 9.2 (3.0-18.6) months respectively (P = 0.413). In GnRH group, LH ((0.5 ± 0.6) vs (3.4 ± 2.4) U/L, P treatment. In GnRH group, at the end of follow-up, TT ((1.0 ± 1.0) vs (7.4 ± 5.2) nmol/L, P treatment time for initial sperm appearance than HCG/HMG group ((6.5 ± 3.1) vs (10.8 ± 3.7) months, P = 0.001). Pulsatile GnRH requires a shorter time for initiation of spermatogenesis than gonadotropin therapy in IHH male patients.

  6. Androgen receptor signalling in Vascular Endothelial cells is dispensable for spermatogenesis and male fertility

    Directory of Open Access Journals (Sweden)

    O'Hara Laura

    2012-01-01

    Full Text Available Abstract Background Androgen signalling is essential both for male development and function of the male reproductive system in adulthood. Within the adult testis, Germ cells (GC do not express androgen receptor (AR suggesting androgen-mediated promotion of spermatogenesis must act via AR-expressing somatic cell-types. Several recent studies have exploited the Cre/lox system of conditional gene-targeting to ablate AR function from key somatic cell-types in order to establish the cell-specific role of AR in promotion of male fertility. In this study, we have used a similar approach to specifically ablate AR-signalling from Vascular Endothelial (VE cells, with a view to defining the significance of androgen signalling within this cell-type on spermatogenesis. Findings AR expression in VE cells of the testicular vasculature was confirmed using an antibody against AR. A Cre-inducible fluorescent reporter line was used to empirically establish the utility of a mouse line expressing Cre Recombinase driven by the Tie2-Promoter, for targeting VE cells. Immunofluorescent detection revealed expression of YFP (and therefore Cre Recombinase function limited to VE cells and an interstitial population of cells, believed to be macrophages, that did not express AR. Mating of Tie2-Cre males to females carrying a floxed AR gene produced Vascular Endothelial Androgen Receptor Knockout (VEARKO mice and littermate controls. Ablation of AR from all VE cells was confirmed; however, no significant differences in bodyweight or reproductive tissue weights could be detected in VEARKO animals and spermatogenesis and fertility was unaffected. Conclusions We demonstrate the successful generation and empirical validation of a cell-specific knockout of AR from VE cells, and conclude that AR expression in VE cells is not essential for spermatogenesis or male fertility.

  7. Spermatogenesis in adult rhesus monkeys following irradiation with X-rays or fission neutrons

    International Nuclear Information System (INIS)

    Rooij, D.G. de; Sonneveld, P.; Bekkum, D.W. van

    A group of male rhesus monkeys was exposed to total body irradiation followed by autologous bone marrow transplantation. The animals were irradiated in the period between 1965 and 1976 and received a dose of 8.5 Gy of X-rays (300 KVP) or 3.6 Gy of 1 MeV fission neutrons. Of this group, a total of 11 male monkeys proved to be evaluable for studying the effects of irradiation on spermatogenesis. (Auth.)

  8. Transformational leadership moderates the relationship between emotional exhaustion and turnover intention among community mental health providers.

    Science.gov (United States)

    Green, Amy E; Miller, Elizabeth A; Aarons, Gregory A

    2013-08-01

    Public sector mental health care providers are at high risk for burnout and emotional exhaustion which negatively affect job performance and client satisfaction with services. Few studies have examined ways to reduce these associations, but transformational leadership may have a positive effect. We examine the relationships between transformational leadership, emotional exhaustion, and turnover intention in a sample of 388 community mental health providers. Emotional exhaustion was positively related to turnover intention, and transformational leadership was negatively related to both emotional exhaustion and turnover intention. Transformational leadership moderated the relationship between emotional exhaustion and turnover intention, indicating that having a transformational leader may buffer the effects of providers' emotional exhaustion on turnover intention. Investing in transformational leadership development for supervisors could reduce emotional exhaustion and turnover among public sector mental health providers.

  9. Concept of Heat Recovery from Exhaust Gases

    Science.gov (United States)

    Bukowska, Maria; Nowak, Krzysztof; Proszak-Miąsik, Danuta; Rabczak, Sławomir

    2017-10-01

    The theme of the article is to determine the possibility of waste heat recovery and use it to prepare hot water. The scope includes a description of the existing sample of coal-fired boiler plant, the analysis of working condition and heat recovery proposals. For this purpose, a series of calculations necessary to identify the energy effect of exhaust temperature decreasing and transferring recovery heat to hot water processing. Heat recover solutions from the exhaust gases channel between boiler and chimney section were proposed. Estimation for the cost-effectiveness of such a solution was made. All calculations and analysis were performed for typical Polish conditions, for coal-fired boiler plant. Typicality of this solution is manifested by the volatility of the load during the year, due to distribution of heat for heating and hot water, determining the load variation during the day. Analysed system of three boilers in case of load variation allows to operational flexibility and adaptation of the boilers load to the current heat demand. This adaptation requires changes in the operating conditions of boilers and in particular assurance of properly conditions for the combustion of fuel. These conditions have an impact on the existing thermal loss and the overall efficiency of the boiler plant. On the boiler plant efficiency affects particularly exhaust gas temperature and the excess air factor. Increasing the efficiency of boilers plant is possible to reach by following actions: limiting the excess air factor in coal combustion process in boilers and using an additional heat exchanger in the exhaust gas channel outside of boilers (economizer) intended to preheat the hot water.

  10. Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae).

    Science.gov (United States)

    Gribbins, Kevin; Anzalone, Marla; Collier, Matthew; Granados-González, Gisela; Villagrán-Santa Cruz, Maricela; Hernández-Gallegos, Oswaldo

    2011-10-01

    Sceloporus bicanthalis is a viviparous lizard that lives at higher elevations in Mexico. Adult male S. bicanthalis were collected (n = 36) from the Nevado de Toluca, Mexico (elevation is 4200 m) during August to December, 2007 and January to July, 2008. Testes were extracted, fixed in Trumps, and dehydrated in a graded series of ethanol. Tissues were embedded, sectioned (2 μm), stained, and examined via a light microscope to determine the spermatogenic developmental strategy of S. bicanthalis. In all months examined, the testes were spermiogenically active; based on this, plus the presence of sperm in the lumina of seminiferous tubules, we inferred that S. bicanthalis had year-round or continuous spermatogenesis, unlike most reptiles that occupy a temperate or montane habitat. It was recently reported that seasonally breeding reptiles had a temporal germ cell development strategy similar to amphibians, where germ cells progress through spermatogenesis as a single population, which leads to a single spermiation event. This was much different than spatial development within the testis of other derived amniotes. We hypothesized that germ cell development was temporal in S. bicanthalis. Therefore, we wanted to determine whether reptiles that practice continuous spermatogenesis have a mammalian-like spatial germ cell development, which is different than the typical temperate reptile exhibiting a temporal development. In the present study, S. bicanthalis had a temporal development strategy, despite its continuous spermatogenic cycle, making them similar to tropical anoles. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. X-ray fluorescence microscopy reveals the role of selenium in spermatogenesis

    Science.gov (United States)

    Kehr, Sebastian; Malinouski, Mikalai; Finney, Lydia; Vogt, Stefan; Labunskyy, Vyacheslav M.; Kasaikina, Marina V.; Carlson, Bradley A.; Zhou, You; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2009-01-01

    Selenium (Se) is a trace element with important roles in human health. Several selenoproteins have essential functions in development. However, the cellular and tissue distribution of Se remains largely unknown because of the lack of analytical techniques that image this element with sufficient sensitivity and resolution. Herein, we report that X-ray fluorescence microscopy (XFM) can be used to visualize and quantify the tissue, cellular and subcellular topography of Se. We applied this technique to characterize the role of Se in spermatogenesis and identified a dramatic Se enrichment specifically in late spermatids, a pattern that was not seen in any other elemental maps. This enrichment was due to elevated levels of the mitochondrial form of glutathione peroxidase 4 and was fully dependent on the supplies of Se by Selenoprotein P. High-resolution scans revealed that Se concentrated near the lumen side of elongating spermatids, where structural components of sperm are formed. During spermatogenesis, maximal Se associated with decreased phosphorus, whereas Zn did not change. In sperm, Se was primarily in the midpiece and co-localized with Cu and Fe. XFM allowed quantification of Se in the midpiece (0.8 fg) and head (0.14 fg) of individual sperm cells, revealing the ability of sperm cells to handle the amounts of this element well above its toxic levels. Overall, the use of XFM allowed visualization of tissue and cellular Se and provided important insights in the role of this and other trace elements in spermatogenesis. PMID:19379757

  12. STUDY OF INTRA TESTICULAR REGULATIONS OF SPERMATOGENESIS DIFFERENTIATION BY EX-VIVO APPROACH

    Directory of Open Access Journals (Sweden)

    A. Adaika

    2010-12-01

    Full Text Available The aim of this work is to study the regulation of intratesticular during spermatogenesis ex vivo. To highlight the progress of spermatogenesis ex vivo, we developed two cell culture systems of seminiferous tubules to study the role of local factors that control the proliferation and differentiation of male germ cells. Our studies are based on two main techniques: RT-PCR and RNA extraction to examine changes in the expression of some growth factors in the culture of seminiferous tubules as the SCF, c- Kit and TGFß. The results show, using RT-PCR, that expression of SCF, c-Kit and TGFb is probably not involved in the alterations of spermatogenesis ex vivo. Indeed, their expressions are not modified during three weeks of culture, and their expressions depend on the proportion of cells where they are expressed. Our results also show that clusterin is a marker of Sertoli cells in the culture of seminiferous tubules and its expression is not altered by the presence of germ cells.

  13. Testicular development and establishment of spermatogenesis in Nili-Ravi buffalo bulls.

    Science.gov (United States)

    Ahmad, N; Umair, S; Shahab, M; Arslan, M

    2010-01-01

    Fifteen longitudinally reared Nili-Ravi buffalo bulls (Bubalus bubalis) were slaughtered at 1, 6, 12, 18, and 24 mo of age (n=3 per group) to observe testicular development and to examine qualitatively the establishment of spermatogenesis. With the age held constant, scrotal circumference and testes weight were correlated (0.95; Pfashion (57microm at 1 mo and 178microm at 24 mo), and the lumen formed at 12 mo of age. Differentiation of basal indifferent supporting cells to Sertoli cells started at 6 mo, and formation of Sertoli cells completed near 12 mo of age. Gonocytes predominated at 1 mo, but by 12 mo, most had been replaced by spermatogonia, thus rapid proliferation of tubular contents occurred at 12 mo (testes weight=75g). Spermatocytes were first observed at 12 mo, and their number increased through 18 and 24 mo. Establishment of spermatogenesis, as reflected by appearance of significant number of spermatids, occurred by 18 mo of age (testes weight 122g). Thus, the establishment of spermatogenesis was progressive from birth, and marked changes were observed during the last 6 mo.

  14. Capture of Heat Energy from Diesel Engine Exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  15. 46 CFR 169.609 - Exhaust systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Exhaust systems. 169.609 Section 169.609 Shipping COAST... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... Yacht Council, Inc. Standard P-1, “Safe Installation of Exhaust Systems for Propulsion and Auxiliary...

  16. 49 CFR 325.91 - Exhaust systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Exhaust systems. 325.91 Section 325.91... EMISSION STANDARDS Exhaust Systems and Tires § 325.91 Exhaust systems. Link to an amendment published at 75 FR 57193, Sept. 20, 2010. A motor vehicle does not conform to the visual exhaust system inspection...

  17. Spermatogenesis and spermatozoa ultrastructure of two Dipolydora species (Annelida: Spionidae) from the Sea of Japan.

    Science.gov (United States)

    Radashevsky, Vasily I; Yurchenko, Olga V; Tyurin, Sergey A; Alexandrova, Yana N

    2015-02-01

    Spermatogenesis and the structure of the spermatozoa of two spionid polychaetes Dipolydora bidentata and Dipolydora carunculata are described by light and transmission electron microscopy. Both species are gonochoristic borers in shells of various molluscs. Proliferation of spermatogonia occurs in paired testes regularly arranged in fertile segments, and the rest of spermatogenesis occurs in the coelomic cavity. Early spermatogenesis occurs quite similarly in the two species but results in formation of tetrads of interconnected spermatids in D. bidentata and octads of spermatids in D. carunculata. Three consecutive stages of spermiogenesis are recognized according to the condensation of chromatin in nucleus: (1) early spermatids with heterogeneous, partly clumped chromatin, (2) middle spermatids with homogeneous, coarsely granular chromatin, and (3) late spermatids with homogeneous fibrillar chromatin. Moreover, late stage of spermatids is further classified into two stages, I and II, according to the position of the acrosome and shape of the nucleus. In late spermatids I, the acrosome is situated in the anterior invagination of the funnel-shaped to oval nucleus, whereas in late spermatids II the acrosome is situated on top of the elongated nucleus. Ultrastructural composition of cells at each stage of spermatogenesis is described and illustrated. The possible process of morphogenesis of organelles during spermato- and spermiogenesis is reconstructed for both species. The proacrosomal vesicle first appears in early spermatids near the Golgi complex and then migrates anteriorly; in the middle spermatids, the acrosome comes to lie in a deep anterior nuclear fossa. In late spermatids I, this fossa evaginates and a posterior fossa develops in the nucleus housing basal body and the anterior part of the axoneme. In late spermatids II, the mitochondria elongate and probably reduce in number due to fusion of some of them. The mature spermatozoa in both species are

  18. A tubulin alpha 8 mouse knockout model indicates a likely role in spermatogenesis but not in brain development.

    Directory of Open Access Journals (Sweden)

    Christine P Diggle

    Full Text Available Tubulin alpha 8 (Tuba8 is the most divergent member of the highly conserved alpha tubulin family, and uniquely lacks two key post-translational modification sites. It is abundantly expressed in testis and muscle, with lower levels in the brain. We previously identified homozygous hypomorphic TUBA8 mutations in human subjects with a polymicrogyria (PMG syndrome, suggesting its involvement in development of the cerebral cortex. We have now generated and characterized a Tuba8 knockout mouse model. Homozygous mice were confirmed to lack Tuba8 protein in the testis, but did not display PMG and appeared to be neurologically normal. In response to this finding, we re-analyzed the human PMG subjects using whole exome sequencing. This resulted in identification of an additional homozygous loss-of-function mutation in SNAP29, suggesting that SNAP29 deficiency, rather than TUBA8 deficiency, may underlie most or all of the neurodevelopmental anomalies in these subjects. Nonetheless, in the mouse brain, Tuba8 specifically localised to the cerebellar Purkinje cells, suggesting that the human mutations may affect or modify motor control. In the testis, Tuba8 localisation was cell-type specific. It was restricted to spermiogenesis with a strong acrosomal localization that was gradually replaced by cytoplasmic distribution and was absent from spermatozoa. Although the knockout mice were fertile, the localisation pattern indicated that Tuba8 may have a role in spermatid development during spermatogenesis, rather than as a component of the mature microtubule-rich flagellum itself.

  19. Transformational Leadership Moderates the Relationship between Emotional Exhaustion and Turnover Intention among Community Mental Health Providers

    OpenAIRE

    Green, Amy E.; Miller, Elizabeth A.; Aarons, Gregory A.

    2011-01-01

    Public sector mental health care providers are at high risk for burnout and emotional exhaustion which negatively affect job performance and client satisfaction with services. Few studies have examined ways to reduce these associations, but transformational leadership may have a positive effect. We examine the relationships between transformational leadership, emotional exhaustion, and turnover intention in a sample of 388 community mental health providers. Emotional exhaustion was positively...

  20. Semiconductor industry wafer fab exhaust management

    CERN Document Server

    Sherer, Michael J

    2005-01-01

    Given the myriad exhaust compounds and the corresponding problems that they can pose in an exhaust management system, the proper choice of such systems is a complex task. Presenting the fundamentals, technical details, and general solutions to real-world problems, Semiconductor Industry: Wafer Fab Exhaust Management offers practical guidance on selecting an appropriate system for a given application. Using examples that provide a clear understanding of the concepts discussed, Sherer covers facility layout, support facilities operations, and semiconductor process equipment, followed by exhaust types and challenges. He reviews exhaust point-of-use devices and exhaust line requirements needed between process equipment and the centralized exhaust system. The book includes information on wet scrubbers for a centralized acid exhaust system and a centralized ammonia exhaust system and on centralized equipment to control volatile organic compounds. It concludes with a chapter devoted to emergency releases and a separ...

  1. Application of three-dimensional culture systems to study mammalian spermatogenesis, with an emphasis on the rhesus monkey (Macaca mulatta

    Directory of Open Access Journals (Sweden)

    Mahmoud Huleihel

    2015-01-01

    Full Text Available In vitro culture of spermatogonial stem cells (SSCs has generally been performed using two-dimensional (2D culture systems; however, such cultures have not led to the development of complete spermatogenesis. It seems that 2D systems do not replicate optimal conditions of the seminiferous tubules (including those generated by the SSC niche and necessary for spermatogenesis. Recently, one of our laboratories has been able to induce proliferation and differentiation of mouse testicular germ cells to meiotic and postmeiotic stages including generation of sperm in a 3D soft agar culture system (SACS and a 3D methylcellulose culture system (MCS. It was suggested that SACS and MCS form a special 3D microenvironment that mimics germ cell niche formation in the seminiferous tubules, and thus permits mouse spermatogenesis in vitro. In this review, we (1 provide a brief overview of the differences in spermatogenesis in rodents and primates, (2 summarize data related to attempts to generate sperm in vitro, (3 report for the first time formation of colonies/clusters of cells and differentiation of meiotic (expression of CREM-1 and postmeiotic (expression of acrosin germ cells from undifferentiated spermatogonia isolated from the testis of prepubertal rhesus monkeys and cultured in SACS and MCS, and (4 indicate research needed to optimize 3D systems for in vitroprimate spermatogenesis and for possible future application to man.

  2. Ship exhaust gas plume cooling

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Neele, P.P.

    2004-01-01

    The exhaust gas plume is an important and sometimes dominating contributor to the infrared signature of ships. Suppression of the infrared ship signatures has been studied by TNO for the Royal Netherlands Navy over considerable time. This study deals with the suppression effects, which can be

  3. Male sex interspecies divergence and down regulation of expression of spermatogenesis genes in Drosophila sterile hybrids.

    Science.gov (United States)

    Sundararajan, Vignesh; Civetta, Alberto

    2011-01-01

    Male sex genes have shown a pattern of rapid interspecies divergence at both the coding and gene expression level. A common outcome from crosses between closely-related species is hybrid male sterility. Phenotypic and genetic studies in Drosophila sterile hybrid males have shown that spermatogenesis arrest is postmeiotic with few exceptions, and that most misregulated genes are involved in late stages of spermatogenesis. Comparative studies of gene regulation in sterile hybrids and parental species have mainly used microarrays providing a whole genome representation of regulatory problems in sterile hybrids. Real-time PCR studies can reject or reveal differences not observed in microarray assays. Moreover, differences in gene expression between samples can be dependant on the source of RNA (e.g., whole body vs. tissue). Here we survey expression in D. simulans, D. mauritiana and both intra and interspecies hybrids using a real-time PCR approach for eight genes expressed at the four main stages of sperm development. We find that all genes show a trend toward under expression in the testes of sterile hybrids relative to parental species with only the two proliferation genes (bam and bgcn) and the two meiotic class genes (can and sa) showing significant down regulation. The observed pattern of down regulation for the genes tested can not fully explain hybrid male sterility. We discuss the down regulation of spermatogenesis genes in hybrids between closely-related species within the contest of rapid divergence experienced by the male genome, hybrid sterility and possible allometric changes due to subtle testes-specific developmental abnormalities.

  4. 40 CFR 1065.130 - Engine exhaust.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Engine exhaust. 1065.130 Section 1065... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.130 Engine exhaust. (a) General. Use the exhaust system installed with the engine or one that represents a typical in-use configuration. This...

  5. Exposure assessment in studies on health effects of traffic exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Setaelae, S [Association for the Pulmonary Disabled, Helsinki (Finland); Jaakkola, J J.K. [Helsinki Univ. (Finland). Dept. of Public Health

    1996-12-31

    A main source of outdoor air pollution is road traffic, which produces a complex mixture of nitrogen oxides, carbon monoxide, volatile hydrocarbons, airborne particles and some other compounds. Traffic exhaust affects also the concentrations of ozone and other photo chemical oxidants. In earlier studies those components have had remarkable health effects. Several studies on occupational exposure to automobile exhaust have been published and several studies have been observed an association between both outdoor and indoor pollutant levels and health outcomes. However, there are only a few epidemiological studies in which traffic exhaust, a complex mixture, has been studied in its entirety. During recent years, interesting epidemiological studies of the health effects of this complex mixture have been published. Human exposure assessment for traffic exhaust can be categorized according to the environment of exposure (indoors, outdoors, in-traffic) or to the method of exposure assessment (direct or indirect methods). In this presentation the methods are further categorized into (1) traffic activity, (2) air concentration measurements, and (3) dispersion models, in order to better understand the advantages and disadvantages of different approaches. The objective of this presentation is to make a critical review of exposure assessments in the epidemiological studies on health effects of traffic exhaust. (author)

  6. Exposure assessment in studies on health effects of traffic exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Setaelae, S. [Association for the Pulmonary Disabled, Helsinki (Finland); Jaakkola, J.J.K. [Helsinki Univ. (Finland). Dept. of Public Health

    1995-12-31

    A main source of outdoor air pollution is road traffic, which produces a complex mixture of nitrogen oxides, carbon monoxide, volatile hydrocarbons, airborne particles and some other compounds. Traffic exhaust affects also the concentrations of ozone and other photo chemical oxidants. In earlier studies those components have had remarkable health effects. Several studies on occupational exposure to automobile exhaust have been published and several studies have been observed an association between both outdoor and indoor pollutant levels and health outcomes. However, there are only a few epidemiological studies in which traffic exhaust, a complex mixture, has been studied in its entirety. During recent years, interesting epidemiological studies of the health effects of this complex mixture have been published. Human exposure assessment for traffic exhaust can be categorized according to the environment of exposure (indoors, outdoors, in-traffic) or to the method of exposure assessment (direct or indirect methods). In this presentation the methods are further categorized into (1) traffic activity, (2) air concentration measurements, and (3) dispersion models, in order to better understand the advantages and disadvantages of different approaches. The objective of this presentation is to make a critical review of exposure assessments in the epidemiological studies on health effects of traffic exhaust. (author)

  7. Long-term recovery of spermatogenesis after radiotherapy in patient with testicular cancer

    International Nuclear Information System (INIS)

    Hansen, P.V.; Trykker, H.; Svennkjaer, I.L.; Hvolby, J.

    1990-01-01

    Gonadal function was evaluated before irradiation and by serial analyses after treatment in 27 patients with seminomas and 24 patients with nonseminomatous germ cell tumors of the testis. During subdiaphragmatic irradiation, a median testicular dose of 1.7 reached the remaining testis. Twenty nonseminoma patients were treated with adjuvant chemotherapy. After orchiectomy, 94% had spermatozoa in semen, 49% had a total sperm count exceeding the reference value, and in 67% serum follicle-stimulating hormone levels were normal. The corresponding estimated values 5 and 9 years after treatment were 61%, 13%, 14%, and 84%, 35%, 32%, respectively. A Cox regression analysis of recovery, with azoospermia used as an endpoint, showed that (1) recovery depended on the radiation dose, (2) adjuvant chemotherapy prolonged the recovery period, (3) recovery was decreased in patients with low pretreatment total sperm counts and in patients older than 25 years. A prognostic index was derived from the regression model and radiation dose-response curves were calculated. The authors conlude that a profound, dose-dependent impairment of spermatogenesis is caused by raiation scatter reaching the testis during subdiaphragmal irradiation. An effective gonadal shield should reduce the gonadal dose to a level low enough to preverse spermatogenesis in most patients. (authors). 36 refs.; 4 figs.; 3 tabs

  8. The effect of chronic administration of ketoconazol on spermatogenesis indices and testis tissue in mice

    Directory of Open Access Journals (Sweden)

    S.E Safavi

    2009-02-01

    Full Text Available Ketoconazole, a broad spectrum antifungal agent has been employed widely in the treatment of fungal diseases. In addition to being antifungal, studies have indicated that this drug has an inhibitory effect on steroid hormone production including glucocorticoids and sex hormones and also its administration causes reduction in the amount of blood testosterone level and histologic changes in testicular tissue of laboratory animals. The aim of this study is to determine the effect of long term ketoconazole administration on spermatogenesis indices in testicular tissue of mice. In this experimental study 50 male mice were used which were allocated to 5 groups each containing 10 animals. The mice received a 50 mg/kg dose of ketoconazole daily for a period of 15 days, 1, 2 and 3 months orally. One group was used as the control and the other 4 groups received Ketoconazole, testicular tissue samples were collected at the end of the aforementioned time period, and after preparation of tissue sections and staining with hematoxylin and coin the spermiogenesis indices including tubular differentiation index (TDI, spermatogenesis index (SI and repopulation index (RI were studied. The results indicated that SI and RI decreased significantly (p

  9. Effects of aqueous extract of celery (Apium graveolens L. leaves on spermatogenesis in healthy male rats

    Directory of Open Access Journals (Sweden)

    Ameneh Hardani

    2015-02-01

    Full Text Available Objectives: Nowadays, a lot of attention has been paid to the therapeutic properties of herbs, including evaluation of the effects of these plants on fertility in laboratory animals. Apium graveolens L. (celery has been widely used in traditional medicine for treatment of various disorders including impotency. Therefore, this study was designed to investigate the effects of aqueous extract of A. graveolens on testicular tissue and spermatogenesis in healthy male rats. Materials and Methods: In this research, 24 apparently healthy male rats were divided into three groups, including eight rats in each. The first group as control received only distilled water 1 ml/animal/day. The second and third groups orally received 100 and 200 mg/kg b.w. of the extract, respectively, for 30 days. The day after the last administration of the extract, the rats were sacrificed, the testes were removed entirely, and the morphometric studies were carried out. Epididymal sperm count and histological studies of testicular tissue were conducted. Results: The comparison between the treated and control groups revealed a remarkable increase in the seminiferous tubules diameter, testes volume (p≤0.001, and the number of spermatogonia, primary spermatocytes and spermatozoa. Furthermore, the increase in the number of spermatids and epididymal weight were only significant at high doses of the extract (p≤ 0.05. Conclusions: The results from this study indicated that administration of celery leaf extract may improve spermatogenesis process and also be useful for some sperm fertility parameters.

  10. Oocyte-specific gene Oog1 suppresses the expression of spermatogenesis-specific genes in oocytes.

    Science.gov (United States)

    Honda, Shinnosuke; Miki, Yuka; Miyamoto, Yuya; Kawahara, Yu; Tsukamoto, Satoshi; Imai, Hiroshi; Minami, Naojiro

    2018-05-03

    Oog1, an oocyte-specific gene that encodes a protein of 425 amino acids, is present in five copies on mouse chromosomes 4 and 12. In mouse oocytes, Oog1 mRNA expression begins at embryonic day 15.5 and almost disappears by the late two-cell stage. Meanwhile, OOG1 protein is detectable in oocytes in ovarian cysts and disappears by the four-cell stage; the protein is transported to the nucleus in late one-cell to early two-cell stage embryos. In this study, we examined the role of Oog1 during oogenesis in mice. Oog1 RNAi-transgenic mice were generated by expressing double-stranded hairpin Oog1 RNA, which is processed into siRNAs targeting Oog1 mRNA. Quantitative RT-PCR revealed that the amount of Oog1 mRNA was dramatically reduced in oocytes obtained from Oog1-knockdown mice, whereas the abundance of spermatogenesis-associated transcripts (Klhl10, Tekt2, Tdrd6, and Tnp2) was increased in Oog1 knockdown ovaries. Tdrd6 is involved in the formation of the chromatoid body, Tnp2 contributes to the formation of sperm heads, Tekt2 is required for the formation of ciliary and flagellar microtubules, and Klhl10 plays a key role in the elongated sperm differentiation. These results indicate that Oog1 down-regulates the expression of spermatogenesis-associated genes in female germ cells, allowing them to develop normally into oocytes.

  11. Study of Spermatogenesis in Wistar Adult Rats Administrated to Long Term of Ruta Graveolens

    Directory of Open Access Journals (Sweden)

    Bazrafkan

    2014-07-01

    Full Text Available Background In Iranian folk medicine Ruta graveolens has been used for female and male contraceptive. There are few studies about the effect of this plant on spermatogenesis. Objectives In this study the effect of long term administration of aqueous extract of RG on spermatogenesis has been investigated. Materials and Methods Animals were allocated into 1 control: which did not receive anything, 2 vehicle which received only normal saline and 3 experiment: which received Ruta extract (300 mg/kg administered by gavage once a day for 100 days. A day after last gavage all the individuals were killed by euthanasia. The right testes and epididymis were extruded. The sperm motility was assessed and classified as progressive, no progressive. Results There was a significant decrease in the number of spermatogonia (P 0.05.The fertilization capacity of sperm of rats in experimental group was significantly lower than other groups (P > 0.05. Conclusions It is concluded that the aqueous extract of Ruta graveolens diminishes the reproductive system activity and might be a useful substance for birth control process.

  12. Long-term recovery of spermatogenesis after radiotherapy in patients with testicular cancer.

    Science.gov (United States)

    Hansen, P V; Trykker, H; Svennekjaer, I L; Hvolby, J

    1990-06-01

    Gonadal function was evaluated before irradiation and by serial analyses after treatment in 27 patients with seminomas and 24 patients with nonseminomatous germ cell tumors of the testis. During subdiaphragmatic irradiation, a median testicular dose of 1.7 Gy (range, 1.2 to 4.8 Gy) reached the remaining testis. Twenty nonseminoma patients were treated with adjuvant chemotherapy using vincristine and bleomycin (OB) or cisplatin/dactinomycin, vinblastine, and bleomycin (P/DVB). After orchiectomy, 94% had spermatozoa in semen, 49% had a total sperm count exceeding the reference value (80 x 10(6], and in 67% serum follicle-stimulating hormone levels were normal. The corresponding estimated values 5 and 9 years after treatment were 61%, 13%, 14%, and 84%, 35%, 32%, respectively. A Cox regression analysis of recovery, with azoospermia used as an endpoint, showed that (1) recovery depended on the radiation dose, (2) adjuvant chemotherapy prolonged the recovery period, (3) recovery was decreased in patients with low pretreatment total sperm counts and in patients older than 25 years. A prognostic index was derived from the regression model and radiation dose-response curves were calculated (+/- chemotherapy). We conclude that a profound, dose-dependent impairment of spermatogenesis is caused by radiation scatter reaching the testis during subdiaphragmal irradiation. An effective gonadal shield should reduce the gonadal dose to a level low enough to preserve spermatogenesis in most patients.

  13. Dietary intake of high-dose biotin inhibits spermatogenesis in young rats.

    Science.gov (United States)

    Sawamura, Hiromi; Ikeda, Chieko; Shimada, Ryoko; Yoshii, Yui; Watanabe, Toshiaki

    2015-02-01

    To characterize a new function of the water-soluble vitamin, biotin, in reproduction and early growth in mammals, the effects of high dietary doses of biotin on early spermatogenesis were biochemically and histologically investigated in male rats. Weaned rats were fed a CE-2 (control) diet containing 0.00004% biotin, or a control diet supplemented with 0.01%, 0.1%, or 1.0% biotin. Pair-fed rats were fed a control diet that was equal in calories to the amount ingested by the 1.0% biotin group, because food intake was decreased in the 1.0% biotin group. Food intake and body weight gain were lower in the 1.0% biotin group than in the control group. The kidney, brain and testis weights were significantly lower in the 1.0% biotin group than in the pair-fed group after 6 weeks of feeding. The accumulation of biotin in the liver and testis increased in a dose-dependent manner. In the 1.0% biotin group, the number of mature sperm was markedly lower, that of sperm with morphologically abnormal heads, mainly consisting of round heads, had increased. In addition, the development of seminiferous tubules was inhibited, and few spermatogonia and no spermatocytes were histologically observed. These results demonstrated that the long-term intake of high-dose biotin inhibited spermatogenesis in young male rats. © 2014 Japanese Teratology Society.

  14. Thermodynamic control-oriented modeling of cycle-to-cycle exhaust gas temperature in an HCCI engine

    International Nuclear Information System (INIS)

    Dehghani Firoozabadi, M.; Shahbakhti, M.; Koch, C.R.; Jazayeri, S.A.

    2013-01-01

    Highlights: • First thermodynamic model in the literature to predict exhaust temperature in HCCI engines. • The model can be used for integrated control of HCCI combustion and exhaust temperature. • The model is experimentally validated at over 300 steady state and transient conditions. • Results show a good agreement between predicted and measured exhaust temperatures. • Sensitivity of exhaust gas temperature to variation of engine variables is shown. - Abstract: Model-based control of Homogenous Charge Compression Ignition (HCCI) engine exhaust temperature is a viable solution to optimize efficiency of both engine and the exhaust aftertreatment system. Low exhaust temperature in HCCI engines can limit the abatement of hydrocarbon (HC) and carbon monoxide (CO) emissions in an exhaust aftertreatment system. A physical–empirical model is described for control of exhaust temperature in HCCI engines. This model captures cycle-to-cycle dynamics affecting exhaust temperature and is based on thermodynamic relations and semi-empirical correlations. It incorporates intake and exhaust gas flow dynamics, residual gas mixing, and fuel burn rate and is validated with experimental data from a single cylinder engine at over 300 steady state and transient conditions. The validation results indicate a good agreement between predicted and measured exhaust gas temperature

  15. Boule gene expression underpins the meiotic arrest in spermatogenesis in male rainbow trout (Oncorhynchus mykiss) exposed to DEHP and butachlor.

    Science.gov (United States)

    Ahmadivand, Sohrab; Farahmand, Hamid; Teimoori-Toolabi, Ladan; Mirvaghefi, Alireza; Eagderi, Soheil; Geerinckx, Tom; Shokrpoor, Sara; Rahmati-Holasoo, Hooman

    2016-01-01

    Boule, the ancestor of the DAZ (Deleted in AZoospermia) gene family, in most organisms is mainly involved in male meiosis. The present study investigates the effects of the plasticizer DEHP (50mg/kg body weight) and herbicide butachlor (0.39mg/L) on male rainbow trout (Oncorhynchus mykiss) for a 10-day period in two independent experiments. The results showed that plasma testosterone (T) concentrations were significantly lower in fish exposed to either DEHP or butachlor compared to the control fish (P0.05). In addition, no significant differences were found in the gonadosomatic index (GSI) in both DEHP and butachlor treatments (P>0.05). Histologically, testes of male trout in the control groups were well differentiated and filled with large numbers of cystic structures containing spermatozoa. In contrast, the testes of male trout contained mostly spermatocytes with few spermatozoa in both treated group, suggesting that DEHP and butachlor may inhibit the progression of meiosis. Also, boule gene expression was significantly lower in the testes of male trout affected by DEHP and butachlor in comparison with their control groups (Ptrout. Based on the results, the present study demonstrated that DEHP and butachlor can inhibit the progression of spermatogenesis in male trout, potentially by causing an arrest of meiosis, maybe due to down-regulation of boule gene expression through T and/or IGF1 via ERK1/2 signaling in T-independent pathways. In addition, these results confirmed that boule can be considered as a predictive marker to assess meiotic efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Effect of Ruta graveolens and Cannabis sativa alcoholic extract on spermatogenesis in the adult wistar male rats

    Directory of Open Access Journals (Sweden)

    M R Sailani

    2007-01-01

    Full Text Available Objective: The present study was undertaken to evaluate the effects of alcohol extracts of Ruta graveolens and Cannabis sativa that were used traditionally in medieval Persian medicine as male contraceptive drugs, on spermatogenesis in the adult male rats. Materials and Methods: Ethanol extracts of these plants were obtained by the maceration method. The male rats were injected intraperitionaly with C. sativa and R. graveolens 5% ethanol extracts at dose of 20 mg/day for 20 consecutive days, respectively. Twenty-four hours after the last treatment, testicular function was assessed by epididymal sperm count. Result: The statistical results showed that the ethanol extracts of these plants reduced the number of sperms significantly ( P =0.00 in the treatment groups in comparison to the control group. The results also showed that the group, treated by extract of R. graveolens reduced spermatogenesis more than the group treated by extracts of C. sativa . Conclusion: The present study demonstrated the spermatogenesis reducing properties of the ethanol extracts of R. graveolens and C. sativa in the adult male wistar rats but more studies are necessary to reveal the mechanism of action that is involved in spermatogenesis.

  17. Expression profiles of relaxin family peptides and their receptors indicate their influence on spermatogenesis in the domestic cat (Felis catus).

    Science.gov (United States)

    Braun, B C; Müller, K; Jewgenow, K

    2015-07-01

    Disturbed spermatogenesis is a common problem in felines. Studying spermatogenesis in the domestic cat can improve the understanding of the biological background and help to counteract fertility problems in other feline species. Here, we analyzed 3 relaxin family peptides (relaxin, relaxin-3, and INSL3) and their receptors (RXFP1, RXFP2, and RXFP3) as potential spermatogenic factors involving their expression in the testis at different stages of its development. It may be concluded from its stage-dependent expression that relaxin, together with RXFP1, appears to be involved in the first stage of spermatogenesis, whereas relaxin-3 via binding to RXFP3 influences spermiogenesis. Furthermore, correlations were observed between relaxin, relaxin-3, RXFP1, RXFP2 and RXFP3 messenger RNA expression, and the relative numbers of haploid cells in testes. The peptide INSL3 was highly expressed at all testis development stages. Because of the low and stage-independent expression of its receptor RXFP2, an auto- and/or paracrine function of INSL3 in spermatogenesis seems unlikely. In the adult testis, messenger RNA expression of relaxin, RXFP1, and RXFP3 predominantly occurs in the tubular testis compartment, whereas INLS3 is mainly expressed in the interstitium. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Exhaust gas clean up process

    Science.gov (United States)

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  19. Gas turbine exhaust system silencing design

    International Nuclear Information System (INIS)

    Ozgur, D.

    1991-01-01

    Gas turbines are the preferred prime mover in many applications because of their high efficiency, fuel flexibility, and low environmental impact. A typical mid-size machine might have a power rating of 80 MW, a flow of about 1000 kg/hr, and an exhaust temperature of over 500C. The most powerful single source of noise is generally the exhaust, which may generate over a kilowatt of acoustic energy. This paper reports that there are two important ways in which exhaust systems can radiate noise. The first is through the discharge of the exhaust duct, with the exhaust gas. Because of the large quantity of hot gas, the duct exit is always oriented vertically; it may be fairly high in the air in order to promote dispersion of the exhaust plume. This source is almost always attenuated by means of a silencer located somewhere in the ductwork. The second source of noise is often called breakout; it is the radiation of exhaust noise through the walls of the ducting. Breakout is most important for those sections of the exhaust duct which lie upstream of the silencer, where sound levels inside the ducting are highest. Both exhaust duct exit noise and breakout noise can be calculated from the sound power level of the gas turbine exhaust and the sound transmission loss (TL) of the silencer and ducting

  20. Sublethal effects of phenol on spermatogenesis in sea urchins (Anthocidaris crassispina)

    International Nuclear Information System (INIS)

    Au, D.W.T.; Yurchenko, O.V.; Reunov, A.A.

    2003-01-01

    Adult sea urchins, Anthocidaris crassispina, were exposed to 0.1 and 10 mg L -1 phenol for 4 weeks. Abnormal sperm development was clearly evident in phenol-treated sea urchins, although no mortality was found throughout the exposure period. Occurrences of multinucleate sperm cells (including spermatocytes to spermatozoa) showed a significant increase from 0.07% in the control to 10.7% and 43.3% in the 0.1- and 10-mg L -1 treatments, respectively (P -1 phenol-treated sea urchins, respectively (P -1 could lower the quality of sperm and reproductive success in sea urchins, which may threaten the survival of these ecologically important species. The observed impairment of spermatogenesis by phenol might also occur in other invertebrate species

  1. Detecting the effects of toxic agents on spermatogenesis using DNA probes

    International Nuclear Information System (INIS)

    Hecht, N.B.

    1987-01-01

    Advances in the molecular biology of spermatogenesis suggest that DNA probes can be used to monitor the effects of toxic agents in male germ cells of mammals. Molecular hybridization analyses with DNA probes can provide a reproducible methodology capable of detecting changes ranging from massive deletions to single base pair substitutions in the genome of exposed individuals. A constantly increasing number of DNA probes that can be used to detect such alterations in human sperm DNA exist for both ubiquitously expressed proteins and for genes solely expressed in the testis. In this chapter, the currently available testicular stage-specific and/or cell type-specific DNA probes and the techniques by which they can be utilized in reproductive toxicology studies are discussed. The advantages, limitations, and future technological advances of this novel biological marker system for the human male reproductive system are also considered

  2. Checking the Pulse of Vitamin A Metabolism and Signaling during Mammalian Spermatogenesis

    Directory of Open Access Journals (Sweden)

    Travis Kent

    2014-03-01

    Full Text Available Vitamin A has been shown to be essential for a multitude of biological processes vital for mammalian development and homeostasis. Its active metabolite, retinoic acid (RA, is important for establishing and maintaining proper germ cell development. During spermatogenesis, the germ cells orient themselves in very distinct patterns, which have been organized into stages. There is evidence to show that, in the mouse, RA is needed for many steps during germ cell development. Interestingly, RA has been implicated as playing a role within the same two Stages: VII and VIII, where meiosis is initiated and spermiation occurs. The goal of this review is to outline this evidence, exploring the relevant players in retinoid metabolism, storage, transport, and signaling. Finally, this review will provide a potential model for how RA activity is organized across the murine stages of the spermatogenic cycle.

  3. Testicular dysgenesis syndrome comprises some but not all cases of hypospadias and impaired spermatogenesis

    DEFF Research Database (Denmark)

    Jørgensen, N; Rajpert-De Meyts, Ewa; Main, K M

    2010-01-01

    In 2001, when the testicular dysgenesis syndrome (TDS) concept was proposed, it suggested that impaired development of foetal testes could lead to increased risks of cryptorchidism, hypospadias, decreased spermatogenesis or testis cancer. The TDS concept links the pathogenesis of the four disorders...... with cryptorchidism or TGCC. By contrast, recent studies demonstrated that among men with isolated hypospadias, only a fraction of cases are linked to TDS. There is no doubt that TDS contributes to impaired semen quality. This is most obvious for cases with visible dysgenetic features in testis histology......, but in the majority of men with impaired semen quality as the only symptom, an association with TDS is less clear. Such cases have a very heterogeneous aetiology and may be caused by a host of other - often post-natal-factors. In conclusion, the TDS as a holistic concept has inspired new research activities and led...

  4. Effect of temperature on the concentration of plasma gonadotropine and spermatogenesis of the goldfish Carassius auratus

    Energy Technology Data Exchange (ETDEWEB)

    Gillet, C.; Billard, R.; Breton, B.

    1977-01-01

    Concentrations of immunoreactive plasma gonadotropin (c-GtH) were measured for goldfish kept at conditions of temperature held constant or increasing between 10 and 30/sup 0/C, between February and July. At temperatures of 17/sup 0/C or above the levels of plasma c-GtH were significantly (P < 0.005) higher during April and May than at 10/sup 0/C. In April the pituitary concentration of c-GtH was maximum for fish held at 17/sup 0/C or above and the minimum for fish held below 17/sup 0/C, but in June the situation was reversed. A study of the gonads showed that spermatogenesis is faster at 17--24/sup 0/C than at 10/sup 0/C, but at 30/sup 0/C spermatogenic activity was inhibited.

  5. Connexin 43 expression in human and mouse testes with impaired spermatogenesis

    Directory of Open Access Journals (Sweden)

    M Kotula-Balak

    2009-08-01

    Full Text Available Connexin 43 (Cx43 belongs to a family of proteins that form gap junction channels. The aim of this study was to examine the expression of Cx43 in the testis of a patient with Klinefelter’s syndrome and of mice with the mosaic mutation and a partial deletion in the long arm of the Y chromosome. These genetic disorders are characterized by the presence of numerous degenerated seminiferous tubules and impaired spermatogenesis. In mouse testes, the expression and presence of Cx43 were detected by means of immunohistochemistry and Western blot analysis, respectively. In testes of Klinefelter’s patient only immunoexpression of Cx43 was detected. Regardless of the species Cx43 protein was ubiquitously distributed in testes of reproductively normal males, whereas in those with testicular disorders either a weak intensity of staining or no staining within the seminiferous tubules was observed. Moderate to strong or very strong staining was confined to the interstitial tissue. In an immunoblot analysis of testicular homogenates Cx43 appeared as one major band of approximately 43 kDa. Our study adds three more examples of pathological gonads in which the absence or apparent decrease of Cx43 expression within the seminiferous tubules was found. A positive correlation between severe spermatogenic impairment and loss of Cx43 immunoreactivity observed in this study supports previous data that gap junctions play a crucial role in spermatogenesis. Strong Cx43 expression detected mostly in the interstitial tissue of the Klinefelter’s patient may presumably be of importance in sustaining Leydig cell metabolic activity. However, the role of gap junction communication in the control of Leydig cell function seems to be more complex than originally thought.

  6. Mucuna pruriens restores spermatogenesis in mice after exposure to 2-methoxyethanol

    Directory of Open Access Journals (Sweden)

    Putu Oky Tania

    2015-12-01

    Full Text Available Background Increasing industrial activity is causing many problems in reproductive health, such as infertility. The factors causing infertility are hormones, infection, radiation, drugs and chemicals. One of these is 2-methoxyethanol (2-ME. The objective of this study was to evaluate the effect of Mucuna pruriens (MP seed fraction on spermatogenesis, including number of spermatogenic cells and spermatozoal membrane protein profiles after exposure to 2-ME in mice. Methods This study was of experimental design. Thirty mice were randomized into 5 groups, i.e. 2 control groups and 3 treatment groups. All mice were injected subcutaneously with 2-ME doses of 100mg/kg body weight (BW/day, for a period of 12 days. Positive (PC and negative controls (NC were treated with carboxy methyl cellulose (CMC. The three treatment groups were given MP seed fraction in doses of 14 (T1, 28 (T2 and 56 mg/kg BW (T3, respectively, from day 13 until day 64. Data on spermatogenic cells were collected from histological cross-sections and analyzed with one-way ANOVA. The spermatozoal membrane protein profile was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE with silver staining and were analyzed descriptively. Results Administration of MP seed fractions resulted in significantly different numbers of spermatocytes I and round spermatids between PC and T1, T2, and T3. A protein with the molecular weight of 41.6 kDa was expressed in all groups except the positive controls, while a 24.5 kDa protein was expressed in the positive controls only. Conclusion MP seed fraction effectively recovers spermatogenesis loss in mice due to 2-ME exposure.

  7. Mucuna pruriens restores spermatogenesis in mice after exposure to 2-methoxyethanol

    Directory of Open Access Journals (Sweden)

    Putu Oky Ari Tania

    2013-12-01

    Full Text Available Background Increasing industrial activity is causing many problems in reproductive health, such as infertility. The factors causing infertility are hormones, infection, radiation, drugs and chemicals. One of these is 2-methoxyethanol (2-ME. The objective of this study was to evaluate the effect of Mucuna pruriens (MP seed fraction on spermatogenesis, including number of spermatogenic cells and spermatozoal membrane protein profiles after exposure to 2-ME in mice. Methods This study was of experimental design. Thirty mice were randomized into 5 groups, i.e. 2 control groups and 3 treatment groups. All mice were injected subcutaneously with 2-ME doses of 100mg/kg body weight (BW/day, for a period of 12 days. Positive (PC and negative controls (NC were treated with carboxy methyl cellulose (CMC. The three treatment groups were given MP seed fraction in doses of 14 (T1, 28 (T2 and 56 mg/kg BW (T3, respectively, from day 13 until day 64. Data on spermatogenic cells were collected from histological cross-sections and analyzed with one-way ANOVA. The spermatozoal membrane protein profile was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE with silver staining and were analyzed descriptively. Results Administration of MP seed fractions resulted in significantly different numbers of spermatocytes I and round spermatids between PC and T1, T2, and T3. A protein with the molecular weight of 41.6 kDa was expressed in all groups except the positive controls, while a 24.5 kDa protein was expressed in the positive controls only. Conclusion MP seed fraction effectively recovers spermatogenesis loss in mice due to 2-ME exposure.

  8. Two adenine nucleotide translocase paralogues involved in cell proliferation and spermatogenesis in the silkworm Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Ryohei Sugahara

    Full Text Available Mitochondrial adenine nucleotide translocase (ANT specifically acts in ADP/ATP exchange through the mitochondrial inner membrane. This transporter protein thereby plays a significant role in energy metabolism in eukaryotic cells. Most mammals have four paralogous ANT genes (ANT1-4 and utilize these paralogues in different types of cells. The fourth paralogue of ANT (ANT4 is present only in mammals and reptiles and is exclusively expressed in testicular germ cells where it is required for meiotic progression in the spermatocytes. Here, we report that silkworms harbor two ANT paralogues, the homeostatic paralogue (BmANTI1 and the testis-specific paralogue (BmANTI2. The BmANTI2 protein has an N-terminal extension in which the positions of lysine residues in the amino acid sequence are distributed as in human ANT4. An expression analysis showed that BmANTI2 transcripts were restricted to the testis, suggesting the protein has a role in the progression of spermatogenesis. By contrast, BmANTI1 was expressed in all tissues tested, suggesting it has an important role in homeostasis. We also observed that cultured silkworm cells required BmANTI1 for proliferation. The ANTI1 protein of the lepidopteran Plutella xylostella (PxANTI1, but not those of other insect species (or PxANTI2, restored cell proliferation in BmANTI1-knockdown cells suggesting that ANTI1 has similar energy metabolism functions across the Lepidoptera. Our results suggest that BmANTI2 is evolutionarily divergent from BmANTI1 and has developed a specific role in spermatogenesis similar to that of mammalian ANT4.

  9. Full field optical coherence tomography can identify spermatogenesis in a rodent sertoli-cell only model.

    Science.gov (United States)

    Ramasamy, Ranjith; Sterling, Joshua; Manzoor, Maryem; Salamoon, Bekheit; Jain, Manu; Fisher, Erik; Li, Phillip S; Schlegel, Peter N; Mukherjee, Sushmita

    2012-01-01

    Microdissection testicular sperm extraction (micro-TESE) has replaced conventional testis biopsies as a method of choice for obtaining sperm for in vitro fertilization for men with nonobstructive azoospermia. A technical challenge of micro-TESE is that the low magnification inspection of the tubules with a surgical microscope is insufficient to definitively identify sperm-containing tubules, necessitating tissue removal and cytologic assessment. Full field optical coherence tomography (FFOCT) uses white light interference microscopy to generate quick high-resolution tomographic images of fresh (unprocessed and unstained) tissue. Furthermore, by using a nonlaser safe light source (150 W halogen lamp) for tissue illumination, it ensures that the sperm extracted for in vitro fertilization are not photo-damaged or mutagenized. A focal Sertoli-cell only rodent model was created with busulfan injection in adult rats. Ex vivo testicular tissues from both normal and busulfan-treated rats were imaged with a commercial modified FFOCT system, Light-CT™, and the images were correlated with gold standard hematoxylin and eosin staining. Light-CT™ identified spermatogenesis within the seminiferous tubules in freshly excised testicular tissue, without the use of exogenous contrast or fixation. Normal adult rats exhibited tubules with uniform size and shape (diameter 328 ±11 μm). The busulfan-treated animals showed marked heterogeneity in tubular size and shape (diameter 178 ± 35 μm) and only 10% contained sperm within the lumen. FFOCT has the potential to facilitate real-time visualization of spermatogenesis in humans, and aid in micro-TESE for men with infertility.

  10. Effect of chocolate and Propolfenol on rabbit spermatogenesis and sperm quality following bacterial lipopolysaccharide treatment.

    Science.gov (United States)

    Collodel, Giulia; Moretti, Elena; Del Vecchio, Maria Teresa; Biagi, Marco; Cardinali, Raffaella; Mazzi, Lucia; Brecchia, Gabriele; Maranesi, Margherita; Manca, Daniela; Castellini, Cesare

    2014-08-01

    The aims of the study were to evaluate the effects of chocolate and propolis-enriched diets on rabbit spermatogenesis, sperm motility, and ultrastructure following bacterial lipopolysaccharide (LPS) treatment. Thirty-two New Zealand White rabbits were divided into four groups. The LPS-Propolfenol(®) group received propolis (500 mg/kg/day) in their diet for 15 days, while the LPS-chocolate group was fed 70% cacao chocolate (1 g/1 kg/day) for the same period. Following the diet treatments, rabbits in the LPS-Propolfenol(®) and LPS-chocolate groups, and an LPS group received a single intraperitoneal dose of 50 μg/kg LPS, and the control group received only saline. Kinematic sperm traits were evaluated with a computer assisted sperm analyzer (CASA) system, and ultrastructural characteristics were examined by transmission electron microscopy (TEM). Testicular and epididymal tissues were observed by light microscopy and TEM and multiplex real time reverse transcriptase-polymerase chain reaction (RT-PCR) assay was used to detect and quantify toll-like receptor-4 (TLR-4) gene expression. The values of the analyzed semen parameters of rabbits treated with LPS-Propolfenol(®) and LPS-chocolate did not show any variations compared with the control group, but they were lower in rabbits treated only with LPS. Alterations observed in the testicular tissue of LPS treated-rabbits were not detected in specimens from the LPS-chocolate and LPS-Propolfenol(®) groups, which showed normal spermatogenesis. The TLR-4 mRNA expression was similar in controls, in LPS treated, and in LPS-chocolate groups, but it was significantly (p chocolate and propolis-enriched diet showed a protective effect on the spermatogenetic process of buck rabbits following LPS treatment.

  11. Impaired spermatogenesis and gr/gr deletions related to Y chromosome haplogroups in Korean men.

    Directory of Open Access Journals (Sweden)

    Jin Choi

    Full Text Available Microdeletion of the Azoospermia Factor (AZF regions in Y chromosome is a well-known genetic cause of male infertility resulting from spermatogenetic impairment. However, the partial deletions of AZFc region related to spermatogenetic impairment are controversial. In this study, we characterized partial deletion of AZFc region in Korean patients with spermatogenetic impairment and assessed whether the DAZ and CDY1 contributes to the phenotype in patients with gr/gr deletions. Total of 377 patients with azoo-/oligozoospermia and 217 controls were analyzed using multiplex polymerase chain reaction (PCR, analysis of DAZ-CDY1 sequence family variants (SFVs, and quantitative fluorescent (QF-PCR. Of the 377 men with impaired spermatogenesis, 59 cases (15.6% had partial AZFc deletions, including 32 gr/gr (8.5%, 22 b2/b3 (5.8%, four b1/b3 (1.1% and one b3/b4 (0.3% deletion. In comparison, 14 of 217 normozoospermic controls (6.5% had partial AZFc deletions, including five gr/gr (2.3% and nine b2/b3 (4.1% deletions. The frequency of gr/gr deletions was significantly higher in the azoo-/oligozoospermic group than in the normozoospermic control group (p = 0.003; OR = 3.933; 95% CI = 1.509-10.250. Concerning Y haplogroup, we observed no significant differences in the frequency of gr/gr deletions between the case and the control groups in the YAP+ lineages, while gr/gr deletion were significantly higher in azoo-/oligozoospermia than normozoospermia in the YAP- lineage (p = 0.004; OR = 6.341; 95% CI = 1.472-27.312. Our data suggested that gr/gr deletion is associated with impaired spermatogenesis in Koreans with YAP- lineage, regardless of the gr/gr subtypes.

  12. HP1γ function is required for male germ cell survival and spermatogenesis

    Directory of Open Access Journals (Sweden)

    Brown Jeremy P

    2010-04-01

    Full Text Available Abstract Background HP1 proteins are conserved components of eukaryotic constitutive heterochromatin. In mammals, there are three genes that encode HP1-like proteins, termed HP1α, HP1β and HP1γ, which have a high degree of homology This paper describes for the first time, to our knowledge, the physiological function of HP1γ using a gene-targeted mouse. Results While targeting the Cbx3 gene (encoding the HP1γ protein with a conditional targeting vector, we generated a hypomorphic allele (Cbx3hypo, which resulted in much reduced (barely detectable levels of HP1γ protein. Homozygotes for the hypomorphic allele (Cbx3hypo/hypo are rare, with only 1% of Cbx3hypo/hypo animals reaching adulthood. Adult males exhibit a severe hypogonadism that is associated with a loss of germ cells, with some seminiferous tubules retaining only the supporting Sertoli cells (Sertoli cell-only phenotype. The percentage of seminiferous tubules that are positive for L1 ORF1 protein (ORF1p in Cbx3hypo/hypo testes is greater than that for wild-type testes, indicating that L1 retrotransposon silencing is reversed, leading to ectopic expression of ORF1p in Cbx3hypo/hypo germ cells. Conclusions The Cbx3 gene product (the HP1γ protein has a non-redundant function during spermatogenesis that cannot be compensated for by the other two HP1 isotypes. The Cbx3hypo/hypo spermatogenesis defect is similar to that found in Miwi2 and Dnmt3L mutants. The Cbx3 gene-targeted mice generated in this study provide an appropriate model for the study of HP1γ in transposon silencing and parental imprinting.

  13. Desulphurization of exhaust gases in chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1981-01-01

    The sulfur content of exhaust gases can be reduced by: desulphurization of fuels; modification of processes; or treatment of resultant gases. In this paper a few selected examples from the chemical industry in the German Democratic Republic are presented. Using modified processes and treating the resultant gases, the sulphuric content of exhaust gases is effectively reduced. Methods to reduce the sulfur content of exhaust gases are described in the field of production of: sulphuric acid; viscose; fertilizers; and paraffin.

  14. Exhaust system of an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-04

    A catalytic converter system for internal combustion engines is described that includes a means to maintain the catalyst temperature within a predetermined range for the efficient reduction of nitrogen oxides in the exhaust gas. Upstream of the catalytic converter, the exhaust pipe is encased in a structure such that a space is provided for the flow of a coolant around the exhaust pipe in response to the sensed catalytic temperature. A coolant control valve is actuated in response to the temperature sensor.

  15. PIXE analysis of vehicle exhaust particulate

    International Nuclear Information System (INIS)

    Shi Xianfeng; Yao Huiying; Liu Bo; Sun Minde; Xu Huawei; Mi Yong; Shen Hao

    2001-01-01

    PIXE technique on the analysis of vehicle exhaust particulate is introduced. The clement composition and concentration of particulate are obtained. Some elements which are related to environmental pollution such as sulfur lead, silicon and manganese, were analyzed and discussed in detail by PIXE technique Nowadays although unleaded gasoline is widely used, the lead concentration is still very high in exhaust particulate. The concentrations of silicon and manganese in exhaust particulate from different model vehicles are also quite high from measurements. It shows that an evidence for exhaust pollution control could be provided from this work

  16. Biodiesel exhaust: the need for a systematic approach to health effects research.

    Science.gov (United States)

    Larcombe, Alexander N; Kicic, Anthony; Mullins, Benjamin J; Knothe, Gerhard

    2015-10-01

    Biodiesel is a generic term for fuel that can be made from virtually any plant or animal oil via transesterification of triglycerides with an alcohol (and usually a catalyst). Biodiesel has received considerable scientific attention in recent years, as it is a renewable resource that is directly able to replace mineral diesel in many engines. Additionally, some countries have mandated a minimum biodiesel content in all diesel fuel sold on environmental grounds. When combusted, biodiesel produces exhaust emissions containing particulate matter, adsorbed chemicals and a range of gases. In many cases, absolute amounts of these pollutants are lower in biodiesel exhaust compared with mineral diesel exhaust, leading to speculation that biodiesel exhaust may be less harmful to health. Additionally, engine performance studies show that the concentrations of these pollutants vary significantly depending on the renewable oil used to make the biodiesel and the ratio of biodiesel to mineral diesel in the fuel mix. Given the strategic and legislative push towards the use of biodiesel in many countries, a concerning possibility is that certain biodiesels may produce exhaust emissions that are more harmful to health than others. This variation suggests that a comprehensive, systematic and comparative approach to assessing the potential for a range of different biodiesel exhausts to affect health is urgently required. Such an assessment could inform biodiesel production priorities, drive research and development into new exhaust treatment technologies, and ultimately minimize the health impacts of biodiesel exhaust exposure. © 2015 Asian Pacific Society of Respirology.

  17. Effects of tyrosine kinase inhibitors on spermatogenesis and pituitary gonadal axis in males with chronic myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Yassin MA

    2014-08-01

    Full Text Available Objective: The introduction of several classes of targeted therapeutics for the treatment of chronic myelogenous leukemia (CML raises the question of whether male fertility is affected and the degree of this affection, if any, among the different generations of tyrosine kinase inhibitors (TKIs. Additionally, when two drugs are equally effective, the drug with less toxic effect on fertility is favourable. Our aims were to evaluate semen parameters and pituitary gonadal function before and four months after starting TKIs namely, dasatinib, nilotinib, and imatinib in patients with CML. Design: Prospective study. Setting, patients and interventions: We studied the effect of TKIs' first generation (imatinib and second generation (dasatinib and nilotinib on semen parameters and endocrine functions in 20 eugonadal male patients with CML, aged between 35 to 51 years. They were receiving imatinib (400 mg once daily, dasatinib (100 mg once daily or nilotinib (300 mg twice daily as upfront therapy. We assessed the serum gonadotropins (LH and FSH and testosterone (T secretion and sperm parameters before and after four months of using these TKIs. Results: Four months after starting TKIs, serum testosterone, LH and FSH concentrations decreased significantly. The total sperm count (SC, total and rapid progressive sperm motility, and % sperms with normal morphology decreased significantly versus pre-treatment. After 4 months of therapy, dasatinib had comparatively the least deleterious effects on SC, ejaculate volume (SV, sperm motility and % of sperms with normal morphology (%NM compared to imatinib and nilotinib. Significant correlations were found between serum T concentrations and semen parameters before and after TKIs therapy including SC (r = 0.658 and r = 0.73 respectively, p < 0.001, rapid progressive motility (r = 0.675 and r = 0.758, respectively; p < 0.001, and the % NM (r = 0.752 and r = 0.834, respectively; p < 0.001. After TKIs therapy, LH were

  18. An Investigation on Exhaustion of SAP ERP Users: Influence of Pace of Change and Technostress

    Directory of Open Access Journals (Sweden)

    Prashanta Kumar Roy

    2017-10-01

    Full Text Available Despite recent growing research interest on ERP research, the understanding on ERP induced exhaustion is still limited. This study examines how the pace of change of ERP functionalities and interface causes exhaustion in workplace. For this purpose, we conducted an investigation on 128 ERP users from two different organizations in Bangladesh. We extended theory of technostress by integrating pace of change of ERP system. Result suggests that pace of change on ERP system significantly affect work-overload, work-life conflict and role ambiguity on ERP users. Result also shows that work-overload and role ambiguity are strong predictors for ERP induced exhaustion.

  19. 49 CFR 393.83 - Exhaust systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Exhaust systems. 393.83 Section 393.83... NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.83 Exhaust systems. (a) Every motor... shall have a system to direct the discharge of such fumes. No part shall be located where its location...

  20. Vital exhaustion and risk for cancer

    DEFF Research Database (Denmark)

    Bergelt, Corinna; Christensen, Jane Hvarregaard; Prescott, Eva

    2005-01-01

    Vital exhaustion, defined as feelings of depression and fatigue, has previously been investigated mainly as a risk factor for cardiovascular disease. The authors investigated the association between depressive feelings and fatigue as covered by the concept of vital exhaustion and the risk...... for cancer....

  1. Vacuum exhaust duct used for thermonuclear device

    International Nuclear Information System (INIS)

    Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

    1990-01-01

    The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

  2. Vital exhaustion and risk for cancer

    DEFF Research Database (Denmark)

    Bergelt, Corinna; Christensen, Jane Hvarregaard; Prescott, Eva

    2005-01-01

    Vital exhaustion, defined as feelings of depression and fatigue, has previously been investigated mainly as a risk factor for cardiovascular disease. The authors investigated the association between depressive feelings and fatigue as covered by the concept of vital exhaustion and the risk...

  3. How School Climate Influences Teachers' Emotional Exhaustion: The Mediating Role of Emotional Labor.

    Science.gov (United States)

    Yao, Xiuping; Yao, Meilin; Zong, Xiaoli; Li, Yulan; Li, Xiying; Guo, Fangfang; Cui, Guanyu

    2015-10-08

    Currently, in China, improving the quality of teachers' emotional labor has become an urgent need for most pre-kindergarten through 12th grade (p-12) schools because the new curriculum reform highlights the role of emotion in teaching. A total of 703 primary and high school teachers in Mainland China were investigated regarding their perceptions of school climate, emotional labor strategy and emotional exhaustion via questionnaires. The findings revealed that the teachers' perceptions of the school climate negatively affected surface acting but positively affected deep acting. Surface acting positively predicted emotional exhaustion, and deep acting had no significant effect on emotional exhaustion. Moreover, emotional labor mediated the relationship between the teachers' perceptions of the school climate and emotional exhaustion. Programs aimed at improving the school climate and the teachers' use of appropriate emotional labor strategies should be implemented in schools in Mainland China.

  4. Method for removing soot from exhaust gases

    Science.gov (United States)

    Suib, Steven L.; Dharmarathna, D. A. Saminda; Pahalagedara, Lakshitha R.

    2018-01-16

    A method for oxidizing soot from diesel exhaust gas from a diesel engine. The method involves providing a diesel particulate filter for receiving the diesel exhaust gas; coating a catalyst composition on the diesel particulate filter; and contacting the soot from the diesel exhaust gas with the catalyst coated diesel particulate filter at a temperature sufficient to oxidize the soot to carbon dioxide. The catalyst composition is a doped or undoped manganese oxide octahedral molecular sieve (OMS-2) material. A diesel exhaust gas treatment system that includes a diesel particulate filter for receiving diesel exhaust gas from a diesel engine and collecting soot; and a catalyst composition coated on the diesel particulate filter. The catalyst composition is a doped or undoped manganese oxide octahedral molecular sieve (OMS-2).

  5. Discussion of the effects of recirculating exhaust air on performance and efficiency of a typical microturbine

    International Nuclear Information System (INIS)

    De Paepe, Ward; Delattin, Frank; Bram, Svend; De Ruyck, Jacques

    2012-01-01

    This paper reports on a specific phenomenon, noticed during steam injection experiments on a microturbine. During the considered experiments, measurements indicated an unsteady inlet air temperature of the compressor, resulting in unstable operation of the microturbine. Non-continuous exhaust air recirculation was a possible explanation for the observed behaviour of the microturbine. The aim of this paper is to investigate and demonstrate the effects of exhaust recirculation on a microgasturbine. Depending on wind direction, exhaust air re-entered the engine, resulting in changing inlet conditions which affects the operating regime of the microturbine. For this paper, a series of experiments were performed in the wind tunnel. These series of experiments allowed investigation of the effect of the wind direction on flue gasses flow. Next to the experiments, steady-state simulations of exhaust recirculation were performed in order to study the effect of exhaust recirculation on thermodynamic performance of the microturbine. Dynamic simulations of the non-continuous recirculation revealed the effects of frequency and amplitude on average performance and stability. Results from simulations supported the important impact of exhaust recirculation. Wind tunnel tests demonstrated the influence of the wind direction on recirculation and revealed the necessity to heighten the stack, thus preventing exhaust recirculation. -- Highlights: ► Unstable operation of a T100 microturbine during steam injection tests was noticed, caused by exhaust gas recirculation. ► Wind tunnel tests were performed to study the effect of the wind direction on the recirculation process. ► Steady-state simulations to investigate the effect of exhaust gas recirculation on thermodynamic performance. ► Dynamic simulations to reveal effects of frequency and amplitude on average performance and stability. ► Wind tunnel tests revealed the necessity to heighten the stack to prevent exhaust

  6. Molecular and histological evaluation of tributyltin toxicity on spermatogenesis in a marine fish, the mummichog (Fundulus heteroclitus)

    Energy Technology Data Exchange (ETDEWEB)

    Mochida, Kazuhiko [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan)]. E-mail: kmochida@fra.affrc.go.jp; Ito, Katsutoshi [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan); Kono, Kumiko [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan); Onduka, Toshimitsu [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan); Kakuno, Akira [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan); Fujii, Kazunori [National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, Maruishi 2-17-5, Hatsukaichi, Hiroshima 739-0452 (Japan)

    2007-06-05

    There is still concern about the effects of organotin compounds (OTs) on marine organisms, and especially on their reproductive systems. We investigated the toxicity of tributyltin oxide (TBTO) on spermatogenesis in a marine fish, mummichog, Fundulus heteroclitus. TBTO exposure caused serious histological damage to the testis, including reduction in counts of spermatids and spermatozoa and malformation of somatic cells around the seminal duct. Analysis of the incorporation of bromodeoxyuridine into spermatogenic cells revealed inhibition of the proliferation of germ cells. To find a biomarker for evaluation of the effects of TBTO on fish spermatogenesis, we cloned genes downregulated by TBTO exposure in the mummichog testis, and identified mummichog creatine kinase (mCK). The cDNA sequence of mCK contained an open reading frame encoding 387 amino acid residues (M {sub r} = 43,344). The derived amino acid sequence of mCK was very similar to that of the testicular-type CK of the rainbow trout, Oncorhynchus mykiss. Furthermore, Northern blot analysis revealed that mCK was produced specifically in the testis. We therefore identified mCK in the mummichog as a testicular-type CK. Real-time PCR revealed that exposure of the fish to TBTO significantly reduced mCK expression in the testis. To some extent, this reduction was coincident with that of bromodeoxyuridine incorporation into spermatogenic cells. The mCK gene can therefore be used as a biomarker for evaluating the effects of TBTO on fish spermatogenesis. In addition, levels of expression of the mCK gene in control fish were well correlated with increments in the gonad somatic index (GSI) below 4%. Individuals that were thought to have testicular damage caused by TBTO could be discriminated from those considered normal. The results suggest that TBTO is involved in the suppression of fish spermatogenesis and that analysis of both GSI values and mCK gene expression is useful for evaluating the levels of xenobiotic

  7. Molecular and histological evaluation of tributyltin toxicity on spermatogenesis in a marine fish, the mummichog (Fundulus heteroclitus)

    International Nuclear Information System (INIS)

    Mochida, Kazuhiko; Ito, Katsutoshi; Kono, Kumiko; Onduka, Toshimitsu; Kakuno, Akira; Fujii, Kazunori

    2007-01-01

    There is still concern about the effects of organotin compounds (OTs) on marine organisms, and especially on their reproductive systems. We investigated the toxicity of tributyltin oxide (TBTO) on spermatogenesis in a marine fish, mummichog, Fundulus heteroclitus. TBTO exposure caused serious histological damage to the testis, including reduction in counts of spermatids and spermatozoa and malformation of somatic cells around the seminal duct. Analysis of the incorporation of bromodeoxyuridine into spermatogenic cells revealed inhibition of the proliferation of germ cells. To find a biomarker for evaluation of the effects of TBTO on fish spermatogenesis, we cloned genes downregulated by TBTO exposure in the mummichog testis, and identified mummichog creatine kinase (mCK). The cDNA sequence of mCK contained an open reading frame encoding 387 amino acid residues (M r = 43,344). The derived amino acid sequence of mCK was very similar to that of the testicular-type CK of the rainbow trout, Oncorhynchus mykiss. Furthermore, Northern blot analysis revealed that mCK was produced specifically in the testis. We therefore identified mCK in the mummichog as a testicular-type CK. Real-time PCR revealed that exposure of the fish to TBTO significantly reduced mCK expression in the testis. To some extent, this reduction was coincident with that of bromodeoxyuridine incorporation into spermatogenic cells. The mCK gene can therefore be used as a biomarker for evaluating the effects of TBTO on fish spermatogenesis. In addition, levels of expression of the mCK gene in control fish were well correlated with increments in the gonad somatic index (GSI) below 4%. Individuals that were thought to have testicular damage caused by TBTO could be discriminated from those considered normal. The results suggest that TBTO is involved in the suppression of fish spermatogenesis and that analysis of both GSI values and mCK gene expression is useful for evaluating the levels of xenobiotic pollution

  8. RFX2 is a candidate downstream amplifier of A-MYB regulation in mouse spermatogenesis

    Directory of Open Access Journals (Sweden)

    Kistler Malathi K

    2009-12-01

    Full Text Available Abstract Background Mammalian spermatogenesis involves formation of haploid cells from the male germline and then a complex morphological transformation to generate motile sperm. Focusing on meiotic prophase, some tissue-specific transcription factors are known (A-MYB or suspected (RFX2 to play important roles in modulating gene expression in pachytene spermatocytes. The current work was initiated to identify both downstream and upstream regulatory connections for Rfx2. Results Searches of pachytene up-regulated genes identified high affinity RFX binding sites (X boxes in promoter regions of several new genes: Adam5, Pdcl2, and Spag6. We confirmed a strong promoter-region X-box for Alf, a germ cell-specific variant of general transcription factor TFIIA. Using Alf as an example of a target gene, we showed that its promoter is stimulated by RFX2 in transfected cells and used ChIP analysis to show that the promoter is occupied by RFX2 in vivo. Turning to upstream regulation of the Rfx2 promoter, we identified a cluster of three binding sites (MBS for the MYB family of transcription factors. Because testis is one of the few sites of A-myb expression, and because spermatogenesis arrests in pachytene in A-myb knockout mice, the MBS cluster implicates Rfx2 as an A-myb target. Electrophoretic gel-shift, ChIP, and co-transfection assays all support a role for these MYB sites in Rfx2 expression. Further, Rfx2 expression was virtually eliminated in A-myb knockout testes. Immunohistology on testis sections showed that A-MYB expression is up-regulated only after pachytene spermatocytes have clearly moved away from the tubule wall, which correlates with onset of RFX2 expression, whereas B-MYB expression, by contrast, is prevalent only in earlier spermatocytes and spermatogonia. Conclusion With an expanding list of likely target genes, RFX2 is potentially an important transcriptional regulator in pachytene spermatocytes. Rfx2 itself is a good candidate to be

  9. Health effects of exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Pihlava, T.; Uuppo, M.; Niemi, S.

    2013-11-01

    This report introduces general information about diesel particles and their health effects. The purpose of this report is to introduce particulate matter pollution and present some recent studies made regarding the health effects of particulate matter. The aim is not to go very deeply into the science, but instead to keep the text understandable for the average layman. Particulate matter is a complex mixture of extremely small particles and liquid droplets. These small particles are made up of a number of components that include for example acids, such as nitrates and sulphates, as well as organic chemicals, metals and dust particles from the soil. Particulate matter comes from several sources, such as transportation emissions, industrial emissions, forest fires, cigarette smoke, volcanic ash and climate variations. Particles are divided into coarse particles with diameters less than 10 ..m, fine particles with diameters smaller than 2.5 ..m and ultra-fine particles with diameters less than 0.1 ..m. The particulate matter in diesel exhaust gas is a highly complex mixture of organic, inorganic, solid, volatile and partly volatile compounds. Many of these particles do not form until they reach the air. Many carcinogenic compounds have been found in diesel exhaust gas and it is considered carcinogenic to humans. Particulate matter can cause several health effects, such as premature death in persons with heart or lung disease, cancer, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and an increase in respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. It is estimated that in Finland about 1300 people die prematurely due to particles and the economic loss in the EU due to the health effects of particles can be calculated in the billions. Ultra-fine particles are considered to be the most harmful to human health. Ultrafine particles usually make the most of their quantity and surface area

  10. Molecular cloning of a novel nuclear factor, TDRP1, in spermatogenic cells of testis and its relationship with spermatogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuanchun [Department of Endocrinology, Huashan Hospital, Institute of Endocrinology and Diabetology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Jiang, Haowen [Department of Urology, Huashan Hospital, Institute of Urology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Zhou, Wenbai; Zhang, Zhaoyun; Yang, Zhihong [Department of Endocrinology, Huashan Hospital, Institute of Endocrinology and Diabetology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Lu, Yong [Department of Urology, Huashan Hospital, Institute of Urology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Lu, Bin [Department of Endocrinology, Huashan Hospital, Institute of Endocrinology and Diabetology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Wang, Xiang [Department of Urology, Huashan Hospital, Institute of Urology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Ding, Qiang, E-mail: dingqiangd@hotmail.com [Department of Urology, Huashan Hospital, Institute of Urology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China); Hu, Renming, E-mail: renminghu@fudan.edu.cn [Department of Endocrinology, Huashan Hospital, Institute of Endocrinology and Diabetology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040 (China)

    2010-03-26

    We reported the identification of a novel gene termed TDRP (encoding testis development-related protein) that might be involved in spermatogenesis. The human TDRP gene had two distinct transcripts, TDRP1 and TDRP2, which encoded proteins of 183 aa and 198 aa respectively. Tdrp mRNA was predominantly expressed in testis tissue. We generated rabbit polyclonal antibodies specific against human TDRP1. Immunohistochemistry analysis showed TDRP1 was expressed in spermatogenic cells, especially with high expression in spermatocytes. We provided evidence that TDRP1 distributed in both cytoplasm and nuclei of spermatogenic cells. Expression patterns of Tdrp1 mRNA and its protein were investigated in the rat testis tissues of different developmental stages. Both Tdrp1 mRNA and its protein were barely detected in the testis of neonatal rats, increased remarkably at 3 weeks postpartum, and peaked at 2 months postpartum. We also investigated TDRP1 expressions in testis tissues of azoospermic men with defective spermatogenesis. Western blot analysis showed that TDRP1 expressions were significantly lower in the testis tissues of azoospermic men compared with normal controls. These current data demonstrated that as a nuclear factor, TDRP1 might play an important role in spermatogenesis.

  11. Characterization of Fasciola spp. in Myanmar on the basis of spermatogenesis status and nuclear and mitochondrial DNA markers.

    Science.gov (United States)

    Ichikawa, Madoka; Bawn, Saw; Maw, Ni Ni; Htun, Lat Lat; Thein, Myint; Gyi, Aung; Sunn, Kyaw; Katakura, Ken; Itagaki, Tadashi

    2011-12-01

    Fasciola spp. in Myanmar were characterized on the basis of spermatogenesis status and DNA markers of nuclear internal transcribed spacer 1 (ITS1) and mitochondrial NADH dehydrogenase subunit 1 (nad1). We collected 88 adult flukes from Yangon, Lashio, and Myitkyina. Spermatogenesis status was analyzed by the presence of sperm in the seminal vesicles, and 8 aspermic and 80 spermic flukes were detected. The flukes were identified on the basis of spermatogenesis status and ITS1 types which were analyzed by a PCR-RFLP method, and 80 spermic flukes were identified as F. gigantica. A very low detection rate of aspermic Fasciola sp. indicated that they are not established in Myanmar. In phylogenetic analyses, the 7 aspermic Fasciola sp. from Myitkyina displayed a haplotype in nad1 sequence, which was identical to that of aspermic Fasciola sp. from other Asian countries including China. Therefore, they were probably introduced from China through an infected domestic ruminant. On the other hand, 17 nad1 haplotypes detected in F. gigantica belonged to 2 clades unique to Myanmar, each with a distinct founder haplotype in a network analysis. This indicated a unique history of F. gigantica introduction into Myanmar involving ancient artificial movements of domestic ruminants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Molecular cloning of a novel nuclear factor, TDRP1, in spermatogenic cells of testis and its relationship with spermatogenesis

    International Nuclear Information System (INIS)

    Wang, Xuanchun; Jiang, Haowen; Zhou, Wenbai; Zhang, Zhaoyun; Yang, Zhihong; Lu, Yong; Lu, Bin; Wang, Xiang; Ding, Qiang; Hu, Renming

    2010-01-01

    We reported the identification of a novel gene termed TDRP (encoding testis development-related protein) that might be involved in spermatogenesis. The human TDRP gene had two distinct transcripts, TDRP1 and TDRP2, which encoded proteins of 183 aa and 198 aa respectively. Tdrp mRNA was predominantly expressed in testis tissue. We generated rabbit polyclonal antibodies specific against human TDRP1. Immunohistochemistry analysis showed TDRP1 was expressed in spermatogenic cells, especially with high expression in spermatocytes. We provided evidence that TDRP1 distributed in both cytoplasm and nuclei of spermatogenic cells. Expression patterns of Tdrp1 mRNA and its protein were investigated in the rat testis tissues of different developmental stages. Both Tdrp1 mRNA and its protein were barely detected in the testis of neonatal rats, increased remarkably at 3 weeks postpartum, and peaked at 2 months postpartum. We also investigated TDRP1 expressions in testis tissues of azoospermic men with defective spermatogenesis. Western blot analysis showed that TDRP1 expressions were significantly lower in the testis tissues of azoospermic men compared with normal controls. These current data demonstrated that as a nuclear factor, TDRP1 might play an important role in spermatogenesis.

  13. Diesel exhaust controls and aftertreatment

    Energy Technology Data Exchange (ETDEWEB)

    Rubeli, B. [Natural Resources Canada, Sudbury, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2009-07-01

    This presentation discussed the safe use of diesel fuels in underground mines, with particular reference to advanced technology engines and system technology options for mines. The use of diesel fuels underground requires well designed diesel engines with an effective preventive maintenance programs utilizing diesel emissions testing. The mines must have a well-engineered ventilation system and an adequate air quality monitoring system. An outline of diesel pollutant formation was included in the presentation. Diesel emission control technologies can address localized air quality problems and control emissions at the source. This presentation summarized the best available diesel emission control technologies for underground mines, namely diesel oxidation catalysts (DOC); diesel particulate filters (DPF); active diesel particulate filters (A-DPF); selective catalytic reduction (SCR); water scrubbers; and fume diluters. An emissions control plan using aftertreatment technology should target the vehicles that are the biggest contributors to diesel exhaust. Low sulphur fuel is a prerequisite for most emission control technologies. The successful control of emissions requires knowledge of the high emitting vehicle groups; an integrated ventilation and emission control technology application plan; ambient and tailpipe emissions testing; and training of operators and mechanics. tabs., figs.

  14. Exhaust gas recirculation system for an internal combustion engine

    Science.gov (United States)

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  15. Neutron activation analysis of automobile exhaust pollutants

    International Nuclear Information System (INIS)

    Oakes, T.W.; Furr, A.K.; Adair, D.J.; Parkinson, T.F.

    1977-01-01

    An approximation of the distribution of lead particulate from vehicular exhausts is given. Soil and grass (Poa trivialis) samples were collected at five-foot intervals from the roadside out to 300 feet, at ten-foot intervals from 300 to 350 feet, and at 25-foot intervals from 350 to 600 feet. All samples were irradiated twice: once for a brief period of from 10 to 120 seconds and later for periods of from 6 to 8 hours. The short irradiations were at a thermal neutron flux of 1.2x10 12 ncm -2 sec -1 (decay time=1 min, counting time=8 min). The long irradiations were at a thermal neutron flux of 1.3x10 12 ncm -2 sec -1 , and the samples counted twice at decay intervals of two days and twelve days. The counting intervals were one hour. The spectra were stored on magnetic tape for processing by an IBM 370/158 computer. This initial neutron-activation analysis study has shown that there is an extremely detailed pattern of the effluent from vehicular highway traffic which is strongly affected by micrometeorological conditions. In order to detect these patterns it is necessary to use a very compact sample grid with every possible precaution taken to ensure sample homogeneity and cleanliness. A possibility of elevated levels of pollution may exist at considerable distances from the highway, perhaps even greater than at the immediate roadside. (T.G.)

  16. A NEW EXHAUST VENTILATION SYSTEM DESIGN SOFTWARE

    Directory of Open Access Journals (Sweden)

    H. Asilian Mahabady

    2007-09-01

    Full Text Available A Microsoft Windows based ventilation software package is developed to reduce time-consuming and boring procedure of exhaust ventilation system design. This program Assure accurate and reliable air pollution control related calculations. Herein, package is tentatively named Exhaust Ventilation Design Software which is developed in VB6 programming environment. Most important features of Exhaust Ventilation Design Software that are ignored in formerly developed packages are Collector design and fan dimension data calculations. Automatic system balance is another feature of this package. Exhaust Ventilation Design Software algorithm for design is based on two methods: Balance by design (Static pressure balance and design by Blast gate. The most important section of software is a spreadsheet that is designed based on American Conference of Governmental Industrial Hygienists calculation sheets. Exhaust Ventilation Design Software is developed so that engineers familiar with American Conference of Governmental Industrial Hygienists datasheet can easily employ it for ventilation systems design. Other sections include Collector design section (settling chamber, cyclone, and packed tower, fan geometry and dimension data section, a unit converter section (that helps engineers to deal with units, a hood design section and a Persian HTML help. Psychometric correction is also considered in Exhaust Ventilation Design Software. In Exhaust Ventilation Design Software design process, efforts are focused on improving GUI (graphical user interface and use of programming standards in software design. Reliability of software has been evaluated and results show acceptable accuracy.

  17. Effects of Ferula assa-foetida extract on spermatogenesis of rats

    Directory of Open Access Journals (Sweden)

    2017-11-01

    Full Text Available Background and objectives: Ferula assa-foetida is an herbaceous perennial plant which belongs to Apiaceae family. It is native to the east and central parts of Iran. This old traditional medicine has been used as antispasmodic, carminative, expectorant, laxative, sedative, stimulant, emmenagogue and vermifuge. In addition to the several therapeutic effects of the plant, it is known as an aphrodisiac herb traditionally; therefore, the present study has evaluated the effect of hydro-alcoholic extract of F. assa-foetida on spermatogenesis of rats. Methods: The seeds of the plant (500 g were identified and extracted by aqueous ethanol 80% using maceration methods (3×48 h.Adult male rats (6 weeks were orally treated with 50 mg/kg body weight of extract for 6 weeks. The extract was dispersed in distilled water. Control group received distilled water for the same duration. Some fertility parameters including sperm count, morphology and mobility of sperms with serum levels of testosterone, estrogen, luteinizing hormone (LH and follicle-stimulating hormone (FSH were evaluated using immunoassay methods.  Results: Sperm parameters and levels of testosterone and LH were significantly improved in the treated group compared to the control group. Conclusion: The results revealed that extract of F. assa-foetida significantly (p

  18. Ultrastructural characteristics of spermatogenesis in Pallas's mastiff bat, Molossus molossus (Chiroptera: Molossidae).

    Science.gov (United States)

    Beguelini, Mateus R; Taboga, Sebastião R; Morielle-Versute, Eliana

    2012-07-01

    Despite the large number of species, their wide distribution, and unique reproductive characteristics, Neotropical bats have been poorly studied, and important aspects of the reproduction of these animals have not been elucidated. We made an ultrastructural analysis of spermatogenesis in Molossus molossus (Molossidae). The process of spermatogonial differentiation is similar to that found in other bats and is also relatively similar to that of Primates, with three main spermatogonia types: A(d), A(p), and B. Meiotic divisions proceed similarly to those of most mammals, and spermiogenesis is clearly divided into 12 steps, in the middle of the range known for bats (9-16 steps). Formation of the acrosome is similar to that known from other mammals; however, the ultrastructure of spermatozoa was found to have unique characteristics, including many wavy acrosomal projections on its surface, which seems to be specific for the family Molossidae. Comparing the ultrastructure of the spermatozoon of M. molossus with other bats already study, we observed that three characters vary: morphology of the outer dense fibers, of the perforatorium, and of the spermatozoon head. The great similarity of morphological characters between M. molossus and Platyrrhinus lineatus suggests that M. molossus is more closely related to the Phyllostomidae than to the Rhinolophidae and the Vespertilionidae. Copyright © 2012 Wiley Periodicals, Inc.

  19. The Dnmt3L ADD Domain Controls Cytosine Methylation Establishment during Spermatogenesis

    Directory of Open Access Journals (Sweden)

    Georgios Vlachogiannis

    2015-02-01

    Full Text Available A critical aspect of mammalian gametogenesis is the reprogramming of genomic DNA methylation. The catalytically inactive adaptor Dnmt3L is essential to ensuring this occurs correctly, but the mechanism by which it functions is unclear. Using gene targeting to engineer a single-amino-acid mutation, we show that the Dnmt3L histone H3 binding domain (ADD is necessary for spermatogenesis. Genome-wide single-base-resolution DNA methylome analysis of mutant germ cells revealed overall reductions in CG methylation at repetitive sequences and non-promoter CpG islands. Strikingly, we also observe an even more severe loss of non-CG methylation, suggesting an unexpected role for the ADD in this process. These epigenetic deficiencies were coupled with defects in spermatogonia, with mutant cells displaying marked changes in gene expression and reactivation of retrotransposons. Our results demonstrate that the Dnmt3L ADD is necessary for Dnmt3L function and full reproductive fitness.

  20. Protection from radiation-induced damage to spermatogenesis by hormone treatment

    International Nuclear Information System (INIS)

    Kurdoglu, B.; Wilson, G.; Parchuri, N.; Ye, W.; Meistrich, M.L.

    1994-01-01

    Infertility caused by killing of the spermatogonial stem cells occurs frequently in men treated for cancer with radiotherapy and chemotherapy. We investigated whether pretreatment of rats with testosterone plus estradiol, which reversibly inhibits the completion of spermatogenesis and protects spermatogonial stem cells from procarbazine-induced damage, would also protect these cells from radiation. Adult male LBNF rats were implanted for 6 weeks with capsules containing testosterone and estradiol and then irradiated with doses from 2.5-7.0 Gy. Controls were irradiated with 1.8-3.5 Gy. Implants were removed 1 day after irradiation, and all animals were killed 10 weeks later for assessment of stem cell survival by counting repopulating tubules in histological sections and by sperm head counts. At doses of 2.5 and 3.5 Gy the repopulation indices and sperm head counts were significantly higher (P < 0.001) in the rats treated with testosterone and estradiol than in the controls. Protection factors calculated from the dose-response curves were in the range of 1.5-2.2. Elucidation of the mechanism of protection is essential to apply it to clinical situations. The fact that the spermatogonia are protected against radiation as well as procarbazine indicates that the mechanism does not involve drug delivery or metabolism. 32 refs., 3 figs

  1. Hormonal stimulation of the recovery of spermatogenesis following chemo- or radiotherapy

    International Nuclear Information System (INIS)

    Meistrich, M.L.

    1998-01-01

    Radiation and chemotherapeutic drugs produce prolonged depression of sperm counts in rodents and humans. Previously, three approaches have been developed in experimental animals that have had some success in preventing or reversing this toxicity. These approaches included pretreatment with hormones that suppress spermatogenesis, stimulation of stem cell number, and supplementation with testosterone. A different rationale for the ability of particular hormonal treatments to reverse prolonged azoospermia is presented in this review. In many cases prolonged azoospermia occurs even though the stem spermatogonia survive the toxic insult, but the differentiation of these spermatogonia to produce sperm fails. In the rat, the block appears to be at the differentiation of the A spermatogonia. Hormone treatments with testosterone or with GnRH agonists, which suppress intratesticular testosterone levels, relieve this block and result in the production of differentiating cells. When the hormone treatment is stopped the production of differentiating cells continues, mature sperm are produced, and fertility is restored. If a similar mechanism can be demonstrated to hold in humans, the fertility of men who have been rendered infertile by treatments for testicular and other cancers could be improved. (au)

  2. Acetylation-Mediated Proteasomal Degradation of Core Histones during DNA Repair and Spermatogenesis

    Science.gov (United States)

    Qian, Min-Xian; Pang, Ye; Liu, Cui Hua; Haratake, Kousuke; Du, Bo-Yu; Ji, Dan-Yang; Wang, Guang-Fei; Zhu, Qian-Qian; Song, Wei; Yu, Yadong; Zhang, Xiao-Xu; Huang, Hai-Tao; Miao, Shiying; Chen, Lian-Bin; Zhang, Zi-Hui; Liang, Ya-Nan; Liu, Shan; Cha, Hwangho; Yang, Dong; Zhai, Yonggong; Komatsu, Takuo; Tsuruta, Fuminori; Li, Haitao; Cao, Cheng; Li, Wei; Li, Guo-Hong; Cheng, Yifan; Chiba, Tomoki; Wang, Linfang; Goldberg, Alfred L.; Shen, Yan; Qiu, Xiao-Bo

    2013-01-01

    SUMMARY Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes (“spermatoproteasomes”) contain a spermatid/sperm-specific α-subunit α4s/PSMA8 and/or the catalytic β-subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks, and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis. PMID:23706739

  3. [Effect of tobacco consumption on the spermatogenesis in males with idiopathic infertility].

    Science.gov (United States)

    Reina Bouvet, Beatriz; Vicenta Paparella, Cecilia; Nestor Feldman, Rodolfo

    2007-04-01

    Our objective was to relate the tobacco with seminal spermatogenic parameters such as sperm morphology, concentration of spermatozoids and germinal cells in samples of semen from men with idiopatic infertility. A prospective study was carried out on a population of 131 men with idiopatic infertility that attended the Reproduction Service of Centenario Hospital in Rosario from may 2004 to june 2006. Sperm study according to WHO was carried out evaluating germinal cells and sperm morphology with Papannicolaou. The concentration of spermatozoids was determined by means of a subjective method with Neubauer camera. The studied population was divided in the three groups: G1: smokers more of 20 cigarettes/day, G2: smokers under 20 cigarettes/day, G3 non smokers. The smokers had had the habit for over a year. Results were analyzed with the student's t-test. Statistically significant differences between G1 vs G3 (p0.1). The results show that tobacco alters sperm concentration and morphology with an increase of immature forms, demonstrating an altered spermatogenesis process. The consumption of tobacco should be evaluated to carry out the integral study of infertile man.

  4. Effects of Trans-Resveratrol on hyperglycemia-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase signaling in rat testis

    Energy Technology Data Exchange (ETDEWEB)

    Abdelali, Ala [Department of Anatomy, Faculty of Medicine, Kuwait University (Kuwait); Al-Bader, Maie [Department of Physiology, Faculty of Medicine, Kuwait University (Kuwait); Kilarkaje, Narayana, E-mail: knarayana@hsc.edu.kw [Department of Anatomy, Faculty of Medicine, Kuwait University (Kuwait)

    2016-11-15

    Diabetes induces oxidative stress, DNA damage and alters several intracellular signaling pathways in organ systems. This study investigated modulatory effects of Trans-Resveratrol on type 1 diabetes mellitus (T1DM)-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase (PARP) signaling in rat testis. Trans-Resveratrol administration (5mg/kg/day, ip) to Streptozotocin-induced T1DM adult male Wistar rats from day 22–42 resulted in recovery of induced oxidative stress, abnormal spermatogenesis and inhibited DNA synthesis, and led to mitigation of 8-hydroxy-2'-deoxyguanosine formation in the testis and spermatozoa, and DNA double-strand breaks in the testis. Trans-Resveratrol aggravated T1DM-induced up-regulation of aminoacyl tRNA synthetase complex-interacting multifunctional protein 2 expression; however, it did not modify the up-regulated total PARP and down-regulated PARP1 expressions, but recovered the decreased SirT1 (Sirtuin 1) levels in T1DM rat testis. Trans-Resveratrol, when given alone, reduced the poly (ADP-ribosyl)ation (pADPr) process in the testis due to an increase in PAR glycohydrolase activity, but when given to T1DM rats it did not affect the pADPr levels. T1DM with or without Trans-Resveratrol did not induce nuclear translocation of apoptosis-inducing factor and the formation of 50 kb DNA breaks, suggesting to the lack of caspase-3-independent cell death called parthanatos. T1DM with or without Trans-Resveratrol did not increase necrotic cell death in the testis. Primary spermatocytes, Sertoli cells, Leydig cells and intra-testicular vessels showed the expression of PARP pathway related proteins. In conclusion, Trans-Resveratrol mitigates T1DM-induced sperm abnormality and DNA damage, but does not significantly modulate PARP signaling pathway, except the SirT1 expression, in the rat testis. - Highlights: • Resveratrol inhibits diabetes-induced abnormal sperm morphogenesis • Resveratrol recovers

  5. Effects of Trans-Resveratrol on hyperglycemia-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase signaling in rat testis

    International Nuclear Information System (INIS)

    Abdelali, Ala; Al-Bader, Maie; Kilarkaje, Narayana

    2016-01-01

    Diabetes induces oxidative stress, DNA damage and alters several intracellular signaling pathways in organ systems. This study investigated modulatory effects of Trans-Resveratrol on type 1 diabetes mellitus (T1DM)-induced abnormal spermatogenesis, DNA damage and alterations in poly (ADP-ribose) polymerase (PARP) signaling in rat testis. Trans-Resveratrol administration (5mg/kg/day, ip) to Streptozotocin-induced T1DM adult male Wistar rats from day 22–42 resulted in recovery of induced oxidative stress, abnormal spermatogenesis and inhibited DNA synthesis, and led to mitigation of 8-hydroxy-2'-deoxyguanosine formation in the testis and spermatozoa, and DNA double-strand breaks in the testis. Trans-Resveratrol aggravated T1DM-induced up-regulation of aminoacyl tRNA synthetase complex-interacting multifunctional protein 2 expression; however, it did not modify the up-regulated total PARP and down-regulated PARP1 expressions, but recovered the decreased SirT1 (Sirtuin 1) levels in T1DM rat testis. Trans-Resveratrol, when given alone, reduced the poly (ADP-ribosyl)ation (pADPr) process in the testis due to an increase in PAR glycohydrolase activity, but when given to T1DM rats it did not affect the pADPr levels. T1DM with or without Trans-Resveratrol did not induce nuclear translocation of apoptosis-inducing factor and the formation of 50 kb DNA breaks, suggesting to the lack of caspase-3-independent cell death called parthanatos. T1DM with or without Trans-Resveratrol did not increase necrotic cell death in the testis. Primary spermatocytes, Sertoli cells, Leydig cells and intra-testicular vessels showed the expression of PARP pathway related proteins. In conclusion, Trans-Resveratrol mitigates T1DM-induced sperm abnormality and DNA damage, but does not significantly modulate PARP signaling pathway, except the SirT1 expression, in the rat testis. - Highlights: • Resveratrol inhibits diabetes-induced abnormal sperm morphogenesis • Resveratrol recovers

  6. Power and particle exhaust in tokamaks

    International Nuclear Information System (INIS)

    Stambaugh, R.D.

    1998-01-01

    The status of power and particle exhaust research in tokamaks is reviewed in the light of ITER requirements. There is a sound basis for ITER's nominal design positions; important directions for further research are identified

  7. Soundproofed exhaust system; Gegen stoerenden Abgasschall. Akustik

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Faerber, M.

    2008-03-15

    Acoustic emissions of heating systems are a nuisance, especially the humming noise of big heating boilers and cogeneration units. Noise reduction measures, e.g. with exhaust sound absorbers, should be considered already in the projecting stage. (orig.)

  8. Two phase exhaust for internal combustion engine

    Science.gov (United States)

    Vuk, Carl T [Denver, IA

    2011-11-29

    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  9. The interplay between teamwork, clinicians' emotional exhaustion, and clinician-rated patient safety: a longitudinal study.

    Science.gov (United States)

    Welp, Annalena; Meier, Laurenz L; Manser, Tanja

    2016-04-19

    Effectively managing patient safety and clinicians' emotional exhaustion are important goals of healthcare organizations. Previous cross-sectional studies showed that teamwork is associated with both. However, causal relationships between all three constructs have not yet been investigated. Moreover, the role of different dimensions of teamwork in relation to emotional exhaustion and patient safety is unclear. The current study focused on the long-term development of teamwork, emotional exhaustion, and patient safety in interprofessional intensive care teams by exploring causal relationships between these constructs. A secondary objective was to disentangle the effects of interpersonal and cognitive-behavioral teamwork. We employed a longitudinal study design. Participants were 2100 nurses and physicians working in 55 intensive care units. They answered an online questionnaire on interpersonal and cognitive-behavioral aspects of teamwork, emotional exhaustion, and patient safety at three time points with a 3-month lag. Data were analyzed with cross-lagged structural equation modeling. We controlled for professional role. Analyses showed that emotional exhaustion had a lagged effect on interpersonal teamwork. Furthermore, interpersonal and cognitive-behavioral teamwork mutually influenced each other. Finally, cognitive-behavioral teamwork predicted clinician-rated patient safety. The current study shows that the interrelations between teamwork, clinician burnout, and clinician-rated patient safety unfold over time. Interpersonal and cognitive-behavioral teamwork play specific roles in a process leading from clinician emotional exhaustion to decreased clinician-rated patient safety. Emotionally exhausted clinicians are less able to engage in positive interpersonal teamwork, which might set in motion a vicious cycle: negative interpersonal team interactions negatively affect cognitive-behavioral teamwork and vice versa. Ultimately, ineffective cognitive

  10. Fuel consumption and exhaust emissions of aircrafts

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, R. [Institute of Flightmechanics, Braunschweig (Germany)

    1997-12-31

    The reduction of contamination of sensitive atmospheric layers by improved flight planning steps, is investigated. Calculated results have shown, that a further development of flight track planning allows considerable improvements on fuel consumption and exhaust emissions. Even if air traffic will further increase, optimistic investigations forecast a reduction of the environmental damage by aircraft exhausts, if the effects of improved flight track arrangement and engine innovations will be combined. (R.P.) 4 refs.

  11. An experimental investigation of exhaust emission from agricultural tractors

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Rashid; Rabbani, Hekmat; Lorestani, Ali Nejat; Javadikia, Payam; Jaliliantabar, Farzad [Mechanics of Agricultural Machinery Department, Razi University of Kermanshah (Iran, Islamic Republic of)

    2013-07-01

    Agricultural machinery is an important source of emission of air pollutant in rural locations. Emissions of a specific tractor engine mainly depend on engine speed. Various driving methods and use of implements with different work capacities can affect the engine load. This study deals with the effects of types of tractors and operation conditions on engine emission. In this study two types of agricultural tractors (MF285 and U650) and some tillage implements such as centrifugal type spreader, boom type sprayer and rotary tiller were employed. Some of the exhausted gases from both tractors in each condition were measured such as, hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2) and nitrogen oxide (NO). Engine oil temperature was measured at every step for both types of tractors. Difference between steady-state condition and operation conditions was evaluated. The results showed all exhaust gases that measured and engine oil temperature at every operation conditions are higher than steady-state condition. A general conclusion of the work was that, using various implements and employing different types of tractors effect on engine emissions. The results of variance analysis showed all exhausted gases had a significant relationship with types of implements used at 1%. Also, all exhausted gases except CO had a significant relationship with types of tractors. A further conclusion was that NO emission increased as engine oil temperature increased. The final conclusion was about the difference between MF285 and U650; using U650 at operation conditions is better than MF285 in terms of pollution.

  12. Restoration of spermatogenesis and male fertility using an androgen receptor transgene.

    Directory of Open Access Journals (Sweden)

    William H Walker

    Full Text Available Androgens signal through the androgen receptor (AR to regulate male secondary sexual characteristics, reproductive tract development, prostate function, sperm production, bone and muscle mass as well as body hair growth among other functions. We developed a transgenic mouse model in which endogenous AR expression was replaced by a functionally modified AR transgene. A bacterial artificial chromosome (BAC was constructed containing all AR exons and introns plus 40 kb each of 5' and 3' regulatory sequence. Insertion of an internal ribosome entry site and the EGFP gene 3' to AR allowed co-expression of AR and EGFP. Pronuclear injection of the BAC resulted in six founder mice that displayed EGFP production in appropriate AR expressing tissues. The six founder mice were mated into a Sertoli cell specific AR knockout (SCARKO background in which spermatogenesis is blocked at the meiosis stage of germ cell development. The AR-EGFP transgene was expressed in a cyclical manner similar to that of endogenous AR in Sertoli cells and fertility was restored as offspring were produced in the absence of Sertoli cell AR. Thus, the AR-EGFP transgene under the control of AR regulatory elements is capable of rescuing AR function in a cell selective, AR-null background. These initial studies provide proof of principle that a strategy employing the AR-EGFP transgene can be used to understand AR functions. Transgenic mice expressing selective modifications of the AR-EGFP transgene may provide crucial information needed to elicit the molecular mechanisms by which AR acts in the testis and other androgen responsive tissues.

  13. The Effects of Vitex agnus castus Total Extract on Spermatogenesis of Balb/C Mice

    Directory of Open Access Journals (Sweden)

    M Ramezani

    2008-12-01

    Full Text Available ABSTRACT Introduction & Objective: Vitex agnus castus (Verbenaceae is a phytoestrogeic herb native to the Middle East and southern Europe. It has clinical usage in so many countries. In this research, the effects of Vitex agnus castus extract was investigated on spermatogenesis of male Balb/C mice. Materials & Methods: This is an experimental study in which adult male mice were chosen and divided into 3 groups: control, vehicle, and experimental. Animals were daily injected (i.p. with 65, 165 265, 365, and 465 mg/kg of seed extract for ten consecutive days. Then the animals were weighed and eventually killed by cervical dislocation 2 weeks after the last injection. The caudal part of the right epididymis was used for sperm counting. After macroscopic investigation (weight, diameter and volume of testes tissues were fixed in Buin's fixative. Tissues were cut at 5 µm, stained with Hematoxylin and Eosin (H& E.Ccollected data was analyzed by the SPSS software by using one-way ANOVA. Results: No significant differences in body weight, volume, weight and diameter of testes was seen. Light microscopic studies showed a significant reduction in germinal epithelium in doses of 265 and 365 mg/kg and increased of interstitial tissue area in doses of 265, 365, and 465 mg/kg of extract. There was no significant difference in epithelium thickness and of the diameter of the epididymis. Germinal cells contained pyknotic nuclei and several holes that were found scattered in the tubules. Testis also showed a general disarrangement in various germinal elements of seminiferous tubules. Result of sperms count indicated a significant decreasing of spermatozoa in animals which received 265 and 365 mg/kg of extract. Conclusion: Vitex agnus castus contains essential oils, iridoid glycosides, flavonoids diterpenes, and essential fatty acids. The results suggest that its contraceptive effects is related to its flavonoids and essential fatty acids but further studies is

  14. Cell polarity, cell adhesion, and spermatogenesis: role of cytoskeletons [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Linxi Li

    2017-08-01

    Full Text Available In the rat testis, studies have shown that cell polarity, in particular spermatid polarity, to support spermatogenesis is conferred by the coordinated efforts of the Par-, Crumbs-, and Scribble-based polarity complexes in the seminiferous epithelium. Furthermore, planar cell polarity (PCP is conferred by PCP proteins such as Van Gogh-like 2 (Vangl2 in the testis. On the other hand, cell junctions at the Sertoli cell–spermatid (steps 8–19 interface are exclusively supported by adhesion protein complexes (for example, α6β1-integrin-laminin-α3,β3,γ3 and nectin-3-afadin at the actin-rich apical ectoplasmic specialization (ES since the apical ES is the only anchoring device in step 8–19 spermatids. For cell junctions at the Sertoli cell–cell interface, they are supported by adhesion complexes at the actin-based basal ES (for example, N-cadherin-β-catenin and nectin-2-afadin, tight junction (occludin-ZO-1 and claudin 11-ZO-1, and gap junction (connexin 43-plakophilin-2 and also intermediate filament-based desmosome (for example, desmoglein-2-desmocollin-2. In short, the testis-specific actin-rich anchoring device known as ES is crucial to support spermatid and Sertoli cell adhesion. Accumulating evidence has shown that the Par-, Crumbs-, and Scribble-based polarity complexes and the PCP Vangl2 are working in concert with actin- or microtubule-based cytoskeletons (or both and these polarity (or PCP protein complexes exert their effects through changes in the organization of the cytoskeletal elements across the seminiferous epithelium of adult rat testes. As such, there is an intimate relationship between cell polarity, cell adhesion, and cytoskeletal function in the testis. Herein, we critically evaluate these recent findings based on studies on different animal models. We also suggest some crucial future studies to be performed.

  15. Obif, a Transmembrane Protein, Is Required for Bone Mineralization and Spermatogenesis in Mice.

    Directory of Open Access Journals (Sweden)

    Koji Mizuhashi

    Full Text Available Various kinds of transmembrane and secreted proteins play pivotal roles in development through cell-cell communication. We previously reported that Obif (Osteoblast induction factor, Tmem119, encoding a single transmembrane protein, is expressed in differentiating osteoblasts, and that Obif-/- mice exhibit significantly reduced bone volume in the femur. In the current study, we characterized the Obif protein and further investigated the biological phenotypes of a variety of tissues in Obif-/- mice.First, we found that O-glycosylation of the Obif protein occurs at serine residue 36 in the Obif extracellular domain. Next, we observed that Obif-/- mice exhibit bone dysplasia in association with significantly increased osteoid volume per osteoid surface (OV/OS and osteoid maturation time (Omt, and significantly decreased mineral apposition rate (MAR and bone formation rate per bone surface (BFR/BS. In addition, we observed that Obif-/- mice show a significant decrease in testis weight as well as in sperm number. By histological analysis, we found that Obif is expressed in spermatocytes and spermatids in the developing testis and that spermatogenesis is halted at the round spermatid stage in the Obif-/- testis that lacks sperm. However, the number of litters fathered by male mice was slightly reduced in Obif-/- mice compared with wild-type mice, although this was not statistically significant.Our results, taken together with previous observations, indicate that Obif is a type Ia transmembrane protein whose N-terminal region is O-glycosylated. In addition, we found that Obif is required for normal bone mineralization and late testicular differentiation in vivo. These findings suggest that Obif plays essential roles in the development of multiple tissues.

  16. Endocrine testicular function and spermatogenesis persist in calves after partial scrotal resection but not Burdizzo castration.

    Science.gov (United States)

    Pieler, D; Wohlsein, P; Peinhopf, W; Aurich, J E; Erber, R; Ille, N; Baumgärtner, W; Aurich, C

    2014-06-01

    Bull calves for fattening are often castrated during the first weeks of life. Because androgens stimulate growth, there is an interest in males that are infertile but exposed to endogenous testicular steroids. Such a situation occurs in cryptorchids and has been imitated by shortening the scrotum to an extent that the testes are located in a near-inguinal position. In this study, effects of partial scrotal resection (SR) and Burdizzo castration (BZ) on endocrine testicular function, testes histology and on weight at slaughter were studied and compared to orchidectomized (OR) and gonad-intact calves (CO; n = 10 per group; age at castration, 54 ± 3 days; fattening period, 474 ± 11 days). Plasma testosterone concentrations were determined repeatedly, and testes were collected for histopathology at slaughter. We hypothesized that SR inhibits spermatogenesis without loss of testicular steroidogenesis. Group SR animals gained more weight than groups OR and BZ (P < 0.01). Plasma testosterone concentration increased in groups SR and CO (P < 0.01 vs. BZ and OR). Histologically, in all SR animals, testicular and epididymal tissue was identified with a seminiferous epithelium of up to three-cell layers in two animals. Germ cells including elongated spermatids were present in three animals. Shortening of the scrotum thus induced varying degrees of testicular degeneration but 3/10 animals had to be suspected as fertile. In one BZ animal, spermatids were identified whereas in the remaining BZ animals, testes and epididymides consisted of sclerotic fibrous tissue. Partial SR thus induced a cryptorchid-like status but fertility in individual animals must be assumed. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice.

    Science.gov (United States)

    Comish, Paul B; Drumond, Ana Luiza; Kinnell, Hazel L; Anderson, Richard A; Matin, Angabin; Meistrich, Marvin L; Shetty, Gunapala

    2014-01-01

    Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼ 70% of control and induced atrophic seminiferous tubules in ∼ 30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

  18. Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice.

    Directory of Open Access Journals (Sweden)

    Paul B Comish

    Full Text Available Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1 mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2% and to 80% in the male offspring of L1 (control value 33%. These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼ 70% of control and induced atrophic seminiferous tubules in ∼ 30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i DNA damage is a common mechanism leading to induction of testicular cancer, ii increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

  19. Obif, a Transmembrane Protein, Is Required for Bone Mineralization and Spermatogenesis in Mice.

    Science.gov (United States)

    Mizuhashi, Koji; Chaya, Taro; Kanamoto, Takashi; Omori, Yoshihiro; Furukawa, Takahisa

    2015-01-01

    Various kinds of transmembrane and secreted proteins play pivotal roles in development through cell-cell communication. We previously reported that Obif (Osteoblast induction factor, Tmem119), encoding a single transmembrane protein, is expressed in differentiating osteoblasts, and that Obif-/- mice exhibit significantly reduced bone volume in the femur. In the current study, we characterized the Obif protein and further investigated the biological phenotypes of a variety of tissues in Obif-/- mice. First, we found that O-glycosylation of the Obif protein occurs at serine residue 36 in the Obif extracellular domain. Next, we observed that Obif-/- mice exhibit bone dysplasia in association with significantly increased osteoid volume per osteoid surface (OV/OS) and osteoid maturation time (Omt), and significantly decreased mineral apposition rate (MAR) and bone formation rate per bone surface (BFR/BS). In addition, we observed that Obif-/- mice show a significant decrease in testis weight as well as in sperm number. By histological analysis, we found that Obif is expressed in spermatocytes and spermatids in the developing testis and that spermatogenesis is halted at the round spermatid stage in the Obif-/- testis that lacks sperm. However, the number of litters fathered by male mice was slightly reduced in Obif-/- mice compared with wild-type mice, although this was not statistically significant. Our results, taken together with previous observations, indicate that Obif is a type Ia transmembrane protein whose N-terminal region is O-glycosylated. In addition, we found that Obif is required for normal bone mineralization and late testicular differentiation in vivo. These findings suggest that Obif plays essential roles in the development of multiple tissues.

  20. 46 CFR 182.430 - Engine exhaust pipe installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Engine exhaust pipe installation. 182.430 Section 182... 100 GROSS TONS) MACHINERY INSTALLATION Specific Machinery Requirements § 182.430 Engine exhaust pipe... equipment might come in contact with an exhaust pipe. (b) Exhaust gas must not leak from the piping or any...

  1. 46 CFR 119.430 - Engine exhaust pipe installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Engine exhaust pipe installation. 119.430 Section 119... INSTALLATION Specific Machinery Requirements § 119.430 Engine exhaust pipe installation. (a) The design of all... an exhaust pipe. (b) Exhaust gas must not leak from the piping or any connections. The piping must be...

  2. 46 CFR 119.425 - Engine exhaust cooling.

    Science.gov (United States)

    2010-10-01

    ..., all engine exhaust pipes must be water cooled. (1) Vertical dry exhaust pipes are permissible if installed in compliance with §§ 116.405(c) and 116.970 of this chapter. (2) Horizontal dry exhaust pipes are...) They are installed in compliance with §§ 116.405(c) and 116.970 of this chapter. (b) The exhaust pipe...

  3. Gasoline reformulation to reduce exhaust emissions in Finnish conditions. Influence of sulphur and benzene contents of gasoline on exhaust emissions

    International Nuclear Information System (INIS)

    Kytoe, M.; Aakko, P.; Lappi, M.

    1994-01-01

    At earlier stages of the study it was found that the exhaust emissions from cars are reduced when using fuels with no more than 4 wt% of oxygen. At this stage of the study the work focused on impacts of the sulphur and benzene content of gasoline on exhaust emissions in Finland. Sulphur in gasoline retards the operation of the catalyst, and consequently the exhaust emissions of catalyst cars increase if the sulphur content of the fuel increases. In the present study, evaporation during refuelling were measured for fuels with varying vapour pressures and benzene contents of gasoline. The total hydrocarbon evaporation was reduced by 22 % (10 g) when the vapour pressure of gasoline was reduced from 85 kPa to 65 kPa. Correspondingly, benzene evaporation during refuelling was reduced to a third when the benzene content of the fuel was reduced from the level of 3 wt% to 1 wt%. The reduction of the sulphur content of gasoline from 500 ppm to 100 ppm affected regulated exhaust emissions from the catalyst car at +22 deg C as follows: CO emission was reduced on average by 14 % (0.175 g/km), CH emission by 7 % (0.010 g/km) and NO x emission by 9 % (0.011 g/km). At-7 deg C the percentual changes were smaller. When the benzene content of the fuel was reduced from 3 wt% to 1 wt%, the benzene emission from the catalyst cars was reduced by 20-30 % and from the non-catalyst cars on average by 30 % both at +22 deg C and -7 deg C. The benzene emission ranged 3-22 mg/km for the catalyst cars and 40-90 mg/km for the non-catalyst cars at +22 deg C in the FTP test

  4. Action mechanism of inhibin α-subunit on the development of Sertoli cells and first wave of spermatogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Kailai Cai

    Full Text Available Inhibin is an important marker of Sertoli cell (SC activity in animals with impaired spermatogenesis. However, the precise relationship between inhibin and SC activity is unknown. To investigate this relationship, we partially silenced both the transcription and translation of the gene for the α-subunit of inhibin, Inha, using recombinant pshRNA vectors developed with RNAi-Ready pSIREN-RetroQ-ZsGreen Vector (Clontech Laboratories, Mountain View, Calif. We found that Inha silencing suppresses the cell-cycle regulators Cyclin D1 and Cyclin E and up-regulates the cell-cycle inhibitor P21 (as detected by Western blot analysis, thereby increasing the number of SCs in the G1 phase of the cell cycle and decreasing the amount in the S-phase of the cell cycle (as detected by flow cytometry. Inha silencing also suppressed Pdgfa, Igf1, and Kitl mRNA levels and up-regulated Tgfbrs, Inhba, Inhbb, Cyp11a1, Dhh, and Tjp1 mRNA levels (as indicated by real-time polymerase chain reaction [PCR] analysis. These findings indicate that Inha has the potential to influence the availability of the ligand inhibin and its antagonist activin in the SC in an autocrine manner and inhibit the progression of SC from G1 to S. It may also participate in the development of the blood-testis barrier, Leydig cells, and spermatogenesis through its effect on Dhh, Tjp1, Kitl, and Pdgfa. Real-time PCR and Western blot analyses of Inha, Inhba, and Inhbb mRNA and Inha levels over time show that Inha plays an important role in the formation of round spermatid during the first wave of spermatogenesis in mice.

  5. Histological analysis and identification of spermatogenesis-related genes in 2-, 6-, and 12-month-old sheep testes

    Science.gov (United States)

    Bai, Man; Sun, Limin; Zhao, Jia; Xiang, Lujie; Cheng, Xiaoyin; Li, Jiarong; Jia, Chao; Jiang, Huaizhi

    2017-10-01

    Testis development and spermatogenesis are vital factors that influence male animal fertility. In order to identify spermatogenesis-related genes and further provide a theory basis for finding biomarkers related to male sheep fertility, 2-, 6-, and 12-month-old Small Tail Han Sheep testes were selected to investigate the dynamic changes of sheep testis development. Hematoxylin-eosin routine staining and RNA-Seq technique were used to perform histological and transcriptome analysis for these testes. The results showed that 630, 102, and 322 differentially expressed genes (DEGs) were identified in 2- vs 6-month-old, 6- vs 12-month-old, and 2- vs 12-month-old testes, respectively. GO and KEGG analysis showed the following: DEGs in 2- vs 6-month-old testes were mainly related to the GO terms of sexual maturation and the pathways of multiple metabolism and biosynthesis; in 6- vs 12-month-old testes, most of the GO terms that DEGs involved in were related to metabolism and translation processes; the most significantly enriched pathway is the ribosome pathway. The union of DEGs in 2- vs 6-month-old, 6- vs 12-month-old, and 2- vs 12-month-old testes was categorized into eight profiles by series cluster. Subsequently, the eight profiles were classified into four model profiles and four co-expression networks were constructed based on the DEGs in these model profiles. Finally, 29 key regulatory genes related to spermatogenesis were identified in the four co-expression networks. The expression of 13 DEGs (CA3, APOH, MYOC, CATSPER4, SYT6, SERPINA10, DAZL, ADIPOR2, RAB13, CEP41, SPAG4, ODF1, and FRG1) was validated by RT-PCR.

  6. Occurrence and ultrastructural characterization of "nuage" during oogenesis and early spermatogenesis of Piaractus mesopotamicus Holmberg, 1887 (Teleostei

    Directory of Open Access Journals (Sweden)

    F. C. Abdalla

    Full Text Available We investigated the occurrence and ultrastructurally characterized electrondense nuclear material (nuage released from the nucleus during oogenesis and early spermatogenesis of Piaractus mesopotamicus, a fish from Pantanal Matogrossense (Brazil having a seasonal reproductive cycle. The female germ cells presented two instances of nuclear material extrusion: in the oogonia and in the oocyte in the perinucleolar phase. In males, material with similar morphology and behavior occurred in the spematogonia. In all cases, this material was associated to mitochondria. The possible function of this material is discussed.

  7. Exhaust purification with on-board ammonia production

    Science.gov (United States)

    Robel, Wade J [Peoria, IL; Driscoll, James Joshua [Dunlap, IL; Coleman, Gerald N [Peterborough, GB

    2008-05-13

    A system of ammonia production for a selective catalytic reduction system is provided. The system includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream may be converted into ammonia.

  8. Performance of Installed Cooking Exhaust Devices

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C.; Delp, William W.; Apte, Michael G.; Price, Philip N.

    2011-11-01

    The performance metrics of airflow, sound, and combustion product capture efficiency (CE) were measured for a convenience sample of fifteen cooking exhaust devices, as installed in residences. Results were analyzed to quantify the impact of various device- and installation-dependent parameters on CE. Measured maximum airflows were 70% or lower than values noted on product literature for 10 of the devices. Above-the-cooktop devices with flat bottom surfaces (no capture hood) – including exhaust fan/microwave combination appliances – were found to have much lower CE at similar flow rates, compared to devices with capture hoods. For almost all exhaust devices and especially for rear-mounted downdraft exhaust and microwaves, CE was substantially higher for back compared with front burner use. Flow rate, and the extent to which the exhaust device extends over the burners that are in use, also had a large effect on CE. A flow rate of 95 liters per second (200 cubic feet per minute) was necessary, but not sufficient, to attain capture efficiency in excess of 75% for the front burners. A-weighted sound levels in kitchens exceeded 57 dB when operating at the highest fan setting for all 14 devices evaluated for sound performance.

  9. Engineering task plan for five portable exhausters

    International Nuclear Information System (INIS)

    Rensink, G.E.

    1997-01-01

    Exhausters will be employed to ventilate certain single-shell tanks (SSTs) during salt well pumping campaigns. Active ventilation is necessary to reduce the potential flammable gas inventory (LANL 1996a) in the dome space that may accumulate during steady-state conditions or during/after postulated episodic gas release events. The tanks described in this plan support the activities required to fabricate and test three 500 cfm portable exhausters in the 200 W area shops, and to procure, design, fabricate and test two 1000 cfm units. Appropriate Notice of Construction (NOC) radiological and toxic air pollutant permits will be obtained for the portable exhausters. The portable exhauster design media to be employed to support this task was previously developed for the 241-A-101 exhauster. The same design as A101 will be fabricated with only minor improvements to the design based upon operator input/lessons learned. The safety authorization basis for this program effort will follow SAD 36 (LANL 1996b), and each tank will be reviewed against this SAD for changes or updates. The 1000 cfm units will be designed by the selected offsite contractor according to the specification requirements in KHC-S-O490. The offsite units have been specified to utilize as many of the same components as the 500 cfm units to ensure a more cost effective operation and maintenance through the reduction of spare parts and additional procedures

  10. System for measuring engine exhaust constituents

    International Nuclear Information System (INIS)

    Carduner, K.R.; Colvin, A.D.; Leong, D.Y.W.

    1992-01-01

    This patent describes a system for measuring an automotive engine exhaust constituent. It comprises: a meter for determining the mass of air flowing through the engine and for generating an engine airflow signal corresponding to the airflow; sample handling apparatus; diluent adding means; processor means. This patent also describes a method for using an analyzer to determine the amount of lubricating oil consumed by an automotive engine. It comprises: determining the amount of sulfur dioxide within the room air being drawn into the engine; maintaining a constant total flow comprised of a constant fraction of the engine's exhaust gas and a diluent gas through the analyzer, while: determining the amount of sulfur dioxide contained within the engine's exhaust, determining the amount of sulfur dioxide contained within the engine's exhaust, while operating the engine on room air; determining an efficiency factor for the analyzer; and using the efficiency factor and the concentration of sulfur in the engine oil and the amounts of sulfur dioxide determined in steps a and d to determine the amount of lubrication oil leaving the engine through its exhaust

  11. Lightweight Exhaust Manifold and Exhaust Pipe Ducting for Internal Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved exhaust system for an internal combustion gasoline-and/or diesel-fueled engine includes an engine exhaust manifold which has been fabricated from carbon- carbon composite materials in operative association with an exhaust pipe ducting which has been fabricated from carbon-carbon composite materials. When compared to conventional steel. cast iron. or ceramic-lined iron paris. the use of carbon-carbon composite exhaust-gas manifolds and exhaust pipe ducting reduces the overall weight of the engine. which allows for improved acceleration and fuel efficiency: permits operation at higher temperatures without a loss of strength: reduces the "through-the wall" heat loss, which increases engine cycle and turbocharger efficiency and ensures faster "light-off" of catalytic converters: and, with an optional thermal reactor, reduces emission of major pollutants, i.e. hydrocarbons and carbon monoxide.

  12. The downside of goal-focused leadership: the role of personality in subordinate exhaustion.

    Science.gov (United States)

    Perry, Sara Jansen; Witt, L A; Penney, Lisa M; Atwater, Leanne

    2010-11-01

    Exhaustion has a significant impact on employees and organizations, and leader behavior may affect it. We applied conservation of resources theory to test propositions regarding the joint effects of goal-focused leadership (GFL) and personality on employee exhaustion. We proposed that the relationship between GFL and exhaustion depends on employees' standing on both conscientiousness and emotional stability. Specifically, we expected that high-conscientiousness subordinates experience greater compatibility with a goal-focused leader because of their predisposition to direct resources toward achievement and goal setting, resulting in lower exhaustion under such a leader than among low-conscientiousness employees. Furthermore, high emotional stability may compensate for GFL incompatibility among low-conscientiousness employees by providing additional resources to manage GFL. In contrast, employees low on both traits likely experience greater exhaustion under a goal-focused leader compared with other employees. Results revealed a 3-way interaction in 2 independent samples and were generally supportive of our predictions. GFL was associated with heightened exhaustion among individuals in the low-emotional-stability, low-conscientiousness group but not among workers having any other trait combination. (c) 2010 APA, all rights reserved.

  13. Physical characterization of diesel exhaust nucleation mode particles

    Energy Technology Data Exchange (ETDEWEB)

    Lahde, T.

    2013-11-01

    An increasing concern of the adverse health effects of aerosol particles is forcing the combustion engine industry to develop engines with lower particle emissions. The industry has put most of their efforts into soot control and has achieved a significant reduction in diesel exhaust particle mass. Nevertheless, it is not clear that the large particles, dominating the mass, cause the harmfulness of the exhaust particles in the biological interaction. Nowadays, the harmful potential of diesel exhaust particles often connects with the particle surface area, and the view has turned to particle number below 100 nm size range. Unfortunately, the achieved low exhaust particle mass does not necessarily imply a low particle number. This text focuses on the physical characteristics of diesel exhaust nucleation model particles. The volatility characteristics and the electrical charge state of the particles are studied first. Second, the relation between the nonvolatile nucleation mode emissions and the soot, the nitrogen oxide (NO{sub x}) emissions and the engine parameters are covered. The nucleation mode particles had distinctively different physical characteristics with different after-treatment systems. The nucleation mode was volatile and electrically neutral with a diesel particle filter after-treatment system. Without an after-treatment system or with an after-treatment system with low particle removal efficiency, the nucleation mode was partly nonvolatile and included an electrical charge. The difference suggests different formation routes for the nucleation particles with different after-treatment systems. The existence of the nonvolatile nucleation mode particles also affected the soot mode charge state. The soot charge state was positively biased when the nonvolatile nucleation mode was detected but slightly negatively biased when the nonvolatile nucleation mode was absent. The nonvolatile nucleation mode was always negatively biased. This electrical charge

  14. Baking exhaustion device in thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Mitsunori.

    1987-02-02

    Purpose: To rapidly remove tritium and impurity from the vacuum region in the access port of the baking exhaustion device in a thermonuclear device. Constitution: Each of the gaps at the boundary between a fixed shielding member and a blanket module and at the boundary between the blanket and a divertor is made extremely small so as to minimize the neutron streaming from plasmas. Accordingly, in the case of evacuating the vacuum region in the access port, the gap conductance is extremely poor and the exhaustion speed is low. Then, baking pipeways for flowing high temperature fluids are embedded to the surface layer at the position facing to the vacuum region and the plasma evacuation duct and the vacuum region are connected with an evacuation duct of the access port. By flowing high temperature fluids in the pipeways and conducting evacuation, baking exhaustion can be carried out rapidly. (Kamimura, M.).

  15. Sexual characteristics and spermatogenesis in males of the parthenogenetic gecko Lepidodactylus lugubris (Reptilia, Gekkonidae).

    Science.gov (United States)

    Röll, Beate; von Düring, Monika U G

    2008-01-01

    Obligately parthenogenetic lizards usually are all-female populations of hybrids producing diploid oocytes by premeiotic endomitosis and quasi-normal meiosis. In an all-female strain of the gekkonid lizard Lepidodactylus lugubris several phenotypic males arose spontaneously. The sexual characteristics of these males were studied using light and electron microscopy and compared with normal males of the bisexual genus Lygodactylus. Emphasis was layed on morphology of seminiferous tubules, occurrence of spermatogenic stages and ultrastructure of spermatozoa. The phenotypic males possessed preanal pores filled with secretions and a sexual nephric segment which were exactly the same as in normal, reproductively active males. In the testes, density and morphology of non-spermatogenic cell types, the Leydig and Sertoli cells, indicate a normal production of testicular testosterone and a normal function of the blood-testis barrier, respectively. Both in the normal and the phenotypic males, all meiotic cell types of spermatogenesis can be recognised in the seminiferous tubules and are apparently identical, indicating a normal meiosis without impairment in the phenotypic males. In contrast, the differentiation process of spermatids is markedly disturbed in the phenotypic males of L. lugubris. In the normal male, spermiogenesis results in mature spermatids and spermatozoa with small elongated nuclei, an acrosomal complex, and a flagellar tail possessing one axoneme. Spermatozoa fill both the lumen of most seminiferous tubules and the lumina of ductus epididymidis and ductus deferens. In the phenotypic male, spermiogenesis results in seemingly normal spermatids and in spermatozoa with large, non-elongated, deformed nuclei and/or irregular tails possessing more than one axoneme. Both the lumen of most seminiferous tubules and the lumina of the ductus epididymidis and the ductus deferens contain relatively few spermatozoa. We suggest that the phenotypic males inherited the

  16. PUREX exhaust ventilation system installation test report

    International Nuclear Information System (INIS)

    Blackaby, W.B.

    1997-01-01

    This Acceptance Test Report validates the testing performed, the exceptions logged and resolved and certifies this portion of the SAMCONS has met all design and test criteria to perform as an operational system. The proper installation of the PUREX exhaust ventilation system components and wiring was systematically evaluated by performance of this procedure. Proper operation of PUREX exhaust fan inlet, outlet, and vortex damper actuators and limit switches were verified, using special test equipment, to be correct and installed wiring connections were verified by operation of this equipment

  17. Time course of changes in sperm morphometry and semen variables during testosterone-induced suppression of human spermatogenesis.

    Science.gov (United States)

    Garrett, C; Liu, D Y; McLachlan, R I; Baker, H W G

    2005-11-01

    Quantification of changes in semen may give insight into the testosterone (T)-induced disruption of spermatogenesis in man. A model analogous to flushing of sperm from the genital tract after vasectomy was used to quantify the time course of semen changes in subjects participating in male contraceptive trials using 800 mg T-implant (n = 25) or 200 mg weekly intramuscular injection (IM-T; n = 33). A modified exponential decay model allowed for delayed onset and incomplete disruption to spermatogenesis. Semen variables measured weekly during a 91-day period after initial treatment were fitted to the model. Sperm concentration, total count, motility and morphometry exhibited similar average decay rates (5 day half-life). The mean delay to onset of decline in concentration was 15 (IM-T) and 18 (T-implant) days. The significantly longer (P sperm viability (43 and 55 days), and the change of morphometry to smaller more compact sperm heads are consistent with sperm being progressively cleared from the genital tract rather than continued shedding of immature or abnormal sperm by the seminiferous epithelium. A significant negative relationship was found between lag time and baseline sperm concentration, consistent with longer sperm-epididymal transit times associated with lower daily production rates.

  18. Comparative Study on Histopatological and Histomorphometric Effect of Raw and Cooked Garlic on Spermatogenesis in Testis and Epidydims of Rats

    Directory of Open Access Journals (Sweden)

    khadijeh bahrami

    2014-03-01

    Full Text Available Background &Objective: The present study aims at studying two forms of raw and cooked garlic to identify the effect of this plant on the amount of change in histopatological of spermatogenesis of wistar rat.Materials & Methods: 40 male rats were divided into five equal groups (4 treatment 1 control group the first and second treatment were received palete food consisted of 5% and 15% of raw garlic every day. The third and fourth reatment were received palete food consisted of 5%and 15% of cooked garlic as a food . The control group received standard palete food every day in a month. Finally,the testis were taken out of stomach and after preparing tissue and coloring, they were gone under microscopic studies. Thence, the data were analyzed using SPSS and Duncan test.Results: The study indicated that the amount of sexual cells in the group having cook garlic for 15% compared with that of controlled group had a significant increase and the amount of sexual cells in the group using raw garlic as a food had a significant decrease compared with that of the controlled group.Conclusion: Prescription of cooked garlic has an influence on Proliferation of sexual cells in testicular tubules and epidydymes and so increased spermatogenesis in this group in caparison with the control group. However, prescribing raw garlic has harmful effects on tissue of testis and process of spermatogenes in empric compared with the control group.

  19. Molecular basis for the effects of zinc deficiency on spermatogenesis: An experimental study in the Sprague-dawley rat model

    Directory of Open Access Journals (Sweden)

    Alexander E Omu

    2015-01-01

    Full Text Available Introduction: The objective of this study is to investigate the molecular mechanisms underlying the effects of zinc deficiency on spermatogenesis in the Sprague-Dawley (SD rat. Materials and Methods: Three groups of eight adult male SD rats were maintained for 4 weeks on a normal diet as control, zinc deficient diet and zinc deficient diet with zinc supplementation of 28 mg zinc/kg body weight respectively. Using standard techniques, the following parameters were compared between the three groups of experimental animals at the end of 4 weeks: (a Serum zinc, magnesium (Mg, copper (Cu, selenium (Se and cadmium (Cd, (b serum sex hormones, malondialdehyde (MDA, superoxide dismutase (SOD and glutathione peroxidase (GPX, (c interleukin-4 (IL-4, tumor necrosis factor-alpha (TNF-α, Bcl-2, Bax and caspase-3 expression in the testes, (d assessment of apoptosis of testicular cells using electron microscopy and (e testicular volume and histology using the orchidometer and Johnsen score, respectively. Results: The zinc deficient group showed a reduction of testicular volume, serum concentrations of Zn, Cu, Se, Mg, SOD, GPX, IL-4, Bcl-2 and testosterone (P < 0.05, as well as increased levels of serum Cd, MDA and tissue TNF-α, Bax, caspase-3 and apoptosis of the germ cells (P < 0.05 compared with control and zinc supplementation groups. Conclusion: Zinc deficiency is associated with impaired spermatogenesis because of reduced testosterone production, increased oxidative stress and apoptosis. These findings suggest that zinc has a role in male reproduction.

  20. An Autosomal Factor from Drosophila Arizonae Restores Normal Spermatogenesis in Drosophila Mojavensis Males Carrying the D. Arizonae Y Chromosome

    Science.gov (United States)

    Pantazidis, A. C.; Galanopoulos, V. K.; Zouros, E.

    1993-01-01

    Males of Drosophila mojavensis whose Y chromosome is replaced by the Y chromosome of the sibling species Drosophila arizonae are sterile. It is shown that genetic material from the fourth chromosome of D. arizonae is necessary and sufficient, in single dose, to restore fertility in these males. In introgression and mapping experiments this material segregates as a single Mendelian factor (sperm motility factor, SMF). Light and electron microscopy studies of spermatogenesis in D. mojavensis males whose Y chromosome is replaced by introgression with the Y chromosome of D. arizonae (these males are symbolized as mojY(a)) revealed postmeiotic abnormalities all of which are restored when the SMF of D. arizonae is co-introgressed (these males are symbolized as mojY(a)SMF(a)). The number of mature sperm per bundle in mojY(a)SMF(a) is slightly less than in pure D. mojavensis and is even smaller in males whose fertility is rescued by introgression of the entire fourth chromosome of D. arizonae. These observations establish an interspecific incompatibility between the Y chromosome and an autosomal factor (or more than one tightly linked factors) that can be useful for the study of the evolution of male hybrid sterility in Drosophila and the genetic control of spermatogenesis. PMID:8514139

  1. Toxicological aspects of fuel and exhaust gas

    International Nuclear Information System (INIS)

    Avella, F.

    1993-01-01

    Some aspects concerning fuels (gasoline) and gas exhaust vehicle emissions toxicology are briefly examined in light of the results reported in recent literature on this argument. Many experimental studies carried out on animals and men turn out incomplete and do not allow thorough evaluations, for every aspect, of the risk to which men and the environment are subjected

  2. Application of plasma techniques for exhaust aftertreatment

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, M.; Viden, I.; Šimek, Milan; Pekárek, S.

    2001-01-01

    Roč. 27, 1-4 (2001), s. 306-314 ISSN 0143-3369 R&D Projects: GA ČR GA202/99/1298 Institutional research plan: CEZ:AV0Z2043910 Keywords : Non-thermal plasma, elctrical discharge, exhaust aftertreatment Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.190, year: 2001

  3. Malaria drives T cells to exhaustion

    Directory of Open Access Journals (Sweden)

    Michelle N Wykes

    2014-05-01

    Full Text Available Malaria is a significant global burden but after >30 years of effort there is no vaccine on the market. While the complex life cycle of the parasite presents several challenges, many years of research have also identified several mechanisms of immune evasion by Plasmodium spp.. Recent research on malaria, has investigated the Programmed cell death-1 (PD-1 pathway which mediates exhaustion of T cells, characterized by poor effector functions and recall responses and in some cases loss of the cells by apoptosis. Such studies have shown exhaustion of CD4+ T cells and an unappreciated role for CD8+ T cells in promoting sterile immunity against blood stage malaria. This is because PD-1 mediates up to a 95% reduction in numbers and functional capacity of parasite-specific CD8+ T cells, thus masking their role in protection. The role of T cell exhaustion during malaria provides an explanation for the absence of sterile immunity following the clearance of acute disease which will be relevant to future malaria-vaccine design and suggests the need for novel therapeutic solutions. This review will thus examine the role of PD-1-mediated T cell exhaustion in preventing lasting immunity against malaria.

  4. Cooking exhaust systems for low energy dwellings

    NARCIS (Netherlands)

    Jacobs, P.; Borsboom, W.A.

    2017-01-01

    Especially in airtight low energy dwellings exhaust systems are of utmost importance as cooking can be a major source of PM2.5 exposure. Dwellings should be designed including facilities enabling extraction of at least 83 dm3/s (300 m3/h) directly to outside. Residents should be able to select an

  5. Assessing population exposures to motor vehicle exhaust.

    Science.gov (United States)

    Van Atten, Chris; Brauer, Michael; Funk, Tami; Gilbert, Nicolas L; Graham, Lisa; Kaden, Debra; Miller, Paul J; Bracho, Leonora Rojas; Wheeler, Amanda; White, Ronald H

    2005-01-01

    The need is growing for a better assessment of population exposures to motor vehicle exhaust in proximity to major roads and highways. This need is driven in part by emerging scientific evidence of adverse health effects from such exposures and policy requirements for a more targeted assessment of localized public health impacts related to road expansions and increasing commercial transportation. The momentum for improved methods in measuring local exposures is also growing in the scientific community, as well as for discerning which constituents of the vehicle exhaust mixture may exert greater public health risks for those who are exposed to a disproportionate share of roadway pollution. To help elucidate the current state-of-the-science in exposure assessments along major roadways and to help inform decision makers of research needs and trends, we provide an overview of the emerging policy requirements, along with a conceptual framework for assessing exposure to motor-vehicle exhaust that can help inform policy decisions. The framework includes the pathway from the emission of a single vehicle, traffic emissions from multiple vehicles, atmospheric transformation of emissions and interaction with topographic and meteorologic features, and contact with humans resulting in exposure that can result in adverse health impacts. We describe the individual elements within the conceptual framework for exposure assessment and discuss the strengths and weaknesses of various approaches that have been used to assess public exposures to motor vehicle exhaust.

  6. Exhaust gas treatment by electron beam irradiation

    International Nuclear Information System (INIS)

    Shibamura, Yokichi; Suda, Shoichi; Kobayashi, Toshiki

    1991-01-01

    Among global environmental problems, atmospheric pollution has been discussed since relatively old days, and various countermeasures have been taken, but recently in connection with acid rain, the efficient and economical treatment technology is demanded. As the denitration and desulfurization technology for the exhaust gas from the combustion of fossil fuel, the incineration of city trash and internal combustion engines, three is the treatment method by electron beam irradiation. By irradiating electron beam to exhaust gas, nitrogen oxides and sulfur oxides are oxidized to nitric acid and sulfuric acid, and by promoting the neutralization of these acids with injected alkali, harmless salts are recovered. This method has the merit that nitrogen oxides and surfur oxides can be removed efficiently with a single system. In this report, as for the exhaust gas treatment by electron beam irradiation, its principle, features, and the present status of research and development are described, and in particular, the research on the recent exhaust gas treatment in city trash incineration is introduced. This treatment method is a dry process, accordingly, waste water disposal is unnecessary. The reaction products are utilized as fertilizer, and waste is not produced. (K.I.)

  7. Aircraft Piston Engine Exhaust Emission Symposium

    Science.gov (United States)

    1976-01-01

    A 2-day symposium on the reduction of exhaust emissions from aircraft piston engines was held on September 14 and 15, 1976, at the Lewis Research Center in Cleveland, Ohio. Papers were presented by both government organizations and the general aviation industry on the status of government contracts, emission measurement problems, data reduction procedures, flight testing, and emission reduction techniques.

  8. Exhaust gas afterburner for internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Haertel, G

    1977-05-12

    The invention pertains to an exhaust gas afterburner for internal combustion engines, with an auxiliary fuel device arranged upstream from the afterburner proper and controlled by the rotational speed of the engine, which is additionally controlled by an oxygen or carbon monoxide sensor. The catalytic part of the afterburner, together with a rotochamber, is a separate unit.

  9. Comparative toxicity and mutagenicity of biodiesel exhaust

    Science.gov (United States)

    Biodiesel (BD) is commercially made from the transesterification of plant and animal derived oils. The composition of biodiesel exhaust (BE) depends on the type of fuel, the blend ratio and the engine and operating conditions. While numerous studies have characterized the health ...

  10. Technology-Induced Stressors, Job Satisfaction and Workplace Exhaustion Among Journalism and Mass Communication Faculty.

    Science.gov (United States)

    Beam, Randal A.; Kim, Eunseong; Voakes, Paul S.

    2003-01-01

    Contends that teaching journalism and mass communication has become a technology-intensive occupation. Reports on results of a national study of the use of technology in journalism and mass communication programs. Examines how technology-induced stress affects two aspects of work-life quality: job satisfaction and work-related exhaustion. (PM)

  11. Effects of Teacher Personalities on Emotional Exhaustion: Mediating Role of Emotional Labor

    Science.gov (United States)

    Basim, H. Nejat; Begenirbas, Memduh; Can Yalcin, Rukiye

    2013-01-01

    One of the most indispensable and important elements of education is teachers whose personality closely affects training and education. In this context, this study examined the effects of teachers' personality traits on their emotional exhaustion in a mediating model which centers around emotional labor. Data were obtained from 798 teachers…

  12. Maternal exposure to anti-androgenic compounds, vinclozolin, flutamide and procymidone, has no effects on spermatogenesis and DNA methylation in male rats of subsequent generations

    International Nuclear Information System (INIS)

    Inawaka, Kunifumi; Kawabe, Mayumi; Takahashi, Satoru; Doi, Yuko; Tomigahara, Yoshitaka; Tarui, Hirokazu; Abe, Jun; Kawamura, Satoshi; Shirai, Tomoyuki

    2009-01-01

    To verify whether anti-androgens cause transgenerational effects on spermatogenesis and DNA methylation in rats, gravid Crl:CD(SD) female rats (4 or 5/group, gestational day (GD) 0 = day sperm detected) were intraperitoneally treated with anti-androgenic compounds, such as vinclozolin (100 mg/kg/day), procymidone (100 mg/kg/day), or flutamide (10 mg/kg/day), from GD 8 to GD 15. Testes were collected from F1 male pups at postnatal day (PND) 6 for DNA methylation analysis of the region (210 bp including 7 CpG sites) within the lysophospholipase gene by bisulfite DNA sequencing method. F0 and F1 males underwent the sperm analysis (count, motility and morphology), followed by DNA methylation analysis of the sperm. Remaining F1 males were cohabited with untreated-females to obtain F2 male pups for subsequent DNA methylation analysis of the testes at PND 6. These analyses showed no effects on spermatogenesis and fertility in F1 males of any treatment group. DNA methylation status in testes (F1 and F2 pups at PND 6) or sperms (F1 males at 13 weeks old) of the treatment groups were comparable to the control at all observation points, although DNA methylation rates in testes were slightly lower than those in sperm. In F0 males, no abnormalities in the spermatogenesis, fertility and DNA methylation status of sperm were observed. No transgenerational abnormalities of spermatogenesis and DNA methylation status caused by anti-androgenic compounds were observed.

  13. Human-specific subcellular compartmentalization of P-element induced wimpy testis-like (PIWIL) granules during germ cell development and spermatogenesis

    NARCIS (Netherlands)

    Gomes Fernandes, Maria; He, Nannan; Wang, Fang; Van Iperen, Liesbeth; Eguizabal, Cristina; Matorras, Roberto; Roelen, Bernard A J; Chuva de Sousa Lopes, Susana M

    2018-01-01

    STUDY QUESTION: What is the dynamics of expression of P-element induced wimpy testis-like (PIWIL) proteins in the germline during human fetal development and spermatogenesis? SUMMARY ANSWER: PIWIL1, PIWIL2, PIWIL3 and PIWIL4 were expressed in a sex-specific fashion in human germ cells (GC) during

  14. Transplantation of germ cells from glial cell line-derived neurotrophic factor-overexpressing mice to host testes depleted of endogenous spermatogenesis by fractionated irradiation

    NARCIS (Netherlands)

    Creemers, L. B.; Meng, X.; den Ouden, K.; van Pelt, A. M. M.; Izadyar, F.; Santoro, M.; Sariola, H.; de rooij, D. G.

    2002-01-01

    With a novel method of eliminating spermatogenesis in host animals, male germ cells isolated from mice with targeted overexpression of glial cell line-derived neurotrophic factor (GDNF) were transplanted to evaluate their ability to reproduce the phenotype previously found in the transgenic animals.

  15. Maternal exposure to anti-androgenic compounds, vinclozolin, flutamide and procymidone, has no effects on spermatogenesis and DNA methylation in male rats of subsequent generations.

    Science.gov (United States)

    Inawaka, Kunifumi; Kawabe, Mayumi; Takahashi, Satoru; Doi, Yuko; Tomigahara, Yoshitaka; Tarui, Hirokazu; Abe, Jun; Kawamura, Satoshi; Shirai, Tomoyuki

    2009-06-01

    To verify whether anti-androgens cause transgenerational effects on spermatogenesis and DNA methylation in rats, gravid Crl:CD(SD) female rats (4 or 5/group, gestational day (GD) 0=day sperm detected) were intraperitoneally treated with anti-androgenic compounds, such as vinclozolin (100 mg/kg/day), procymidone (100 mg/kg/day), or flutamide (10 mg/kg/day), from GD 8 to GD 15. Testes were collected from F1 male pups at postnatal day (PND) 6 for DNA methylation analysis of the region (210 bp including 7 CpG sites) within the lysophospholipase gene by bisulfite DNA sequencing method. F0 and F1 males underwent the sperm analysis (count, motility and morphology), followed by DNA methylation analysis of the sperm. Remaining F1 males were cohabited with untreated-females to obtain F2 male pups for subsequent DNA methylation analysis of the testes at PND 6. These analyses showed no effects on spermatogenesis and fertility in F1 males of any treatment group. DNA methylation status in testes (F1 and F2 pups at PND 6) or sperms (F1 males at 13 weeks old) of the treatment groups were comparable to the control at all observation points, although DNA methylation rates in testes were slightly lower than those in sperm. In F0 males, no abnormalities in the spermatogenesis, fertility and DNA methylation status of sperm were observed. No transgenerational abnormalities of spermatogenesis and DNA methylation status caused by anti-androgenic compounds were observed.

  16. The expression pattern of the C-terminal kinesin gene kifc1 during the spermatogenesis of Sepiella maindroni.

    Science.gov (United States)

    Tan, Fu-Qing; Ma, Xiao-Xin; Zhu, Jun-Quan; Yang, Wan-Xi

    2013-12-10

    In this study, we investigated the gene sequence and characteristic of kifc1 in Sepiella maindroni through PCR and RACE technology. Our research aimed particularly at the spatio-temporal expression pattern of kifc1 in the developmental testis through in situ hybridization. The particular role of kifc1 in the spermatogenesis of S. maindroni was our particular interest. Based on multiple protein sequence alignments of KIFC1 homologues, kifc1 gene from the testis of S. maindroni was identified, which consisted of 2432bp including a 2109 in-frame ORF corresponding to 703 continuous amino acids. The encoded polypeptide shared highest similarity with Octopus tankahkeei. Through the prediction of the secondary and tertiary structures, the motor domain of KIFC1 was conserved at the C-terminal, having putative ATP-binding and microtubule-binding motifs, while the N-terminal was more specific to bind various cargoes for cellular events. The stalk domain connecting between the C-terminal and N-terminal determined the direction of movement. According to RT-PCR results, the kifc1 gene is not tissue-specific, commonly detected in different tissues, for example, the testis, liver, stomach, muscle, caecum and gills. Through an in situ hybridization method, the expression pattern of KIFC1 protein mimics in the spermatogenesis of S. maindroni. During the primary stage of the spermatogenesis, the kifc1 mRNA signal was barely detectable. At the early spermatids, the signal started to be present. With the elongation of spermatids, the signals increased substantially. It peaked and gathered around the acrosome area when the spermatids began to transform to spindle shape. As the spermatids developed into mature sperm, the signal vanished. In summary, the expression of kfic1 at specific stages during spermiogenesis and its distribution shed light on the potential functions of this motor in major cytological transformations. The KIFC1 homologue may provide a direct shaping force to the

  17. Effects of microwave oven exposed diet on spermatogenesis in testicular tissue of mice and comparative effects of mentha piperita and melatonin

    International Nuclear Information System (INIS)

    Naheed, K.; Qamar, K.; Jamal, S.

    2017-01-01

    Objective: To observe the effects of microwave oven exposed diet on spermatogenesis in the testis of mice and comparative effects of Mentha piperita and melatonin. Study Design: Laboratory based randomized controlled trial. Place and Duration of Study: Anatomy Department, Army Medical College Rawalpindi, in collaboration with National Institute of Health (NIH), Islamabad, from Apr 2015 to May 2015. Material and Method: Study comprised of 32 adult male mice (BALBc strain) weighing 25-30 gms. Selection criteria based on non-probability (purposive) simple random sampling. Mice were divided into four equal groups of 8 mice each. Group 1, taken as control, was given standard diet 5-10gm/animal/day daily for four weeks. Group 2 was given 5-10 gm/animal/day of microwave oven exposed mice pellets for four weeks. Group 3 received Mentha piperita leaf extract (1g/kg b.wt./day) along with microwave oven exposed mice pellets (5-10gm/animal/day) for 4 weeks and group 4 received oral dosage of melatonin 12mg/kg/day along with microwave oven exposed mice pellets (5-10gm/animal/day) for 4 weeks. After four weeks animals were dissected. The shape, color and any abnormal finding of the testis were observed. Testis were processed, embedded and stained for histological study. Spermatogenesis was assessed by the Johnsons scoring. SPSS 21 was used for statistical analysis. Chi square test was applied for intergroup comparison. Results: Spermatogenesis was suppressed and Johnsons score was decreased from normal spermatogenesis (10) to (6-8) in the experimental group 2 and was more improved in the Mentha piperita treated group as compare to the melatonin. Conclusion: Microwave oven exposed mice pellets suppressed spermatogenesis and Mentha piperita had better ameliorative effects than melatonin on the testis of mice. (author)

  18. TCV experiments towards the development of a plasma exhaust solution

    Science.gov (United States)

    Reimerdes, H.; Duval, B. P.; Harrison, J. R.; Labit, B.; Lipschultz, B.; Lunt, T.; Theiler, C.; Tsui, C. K.; Verhaegh, K.; Vijvers, W. A. J.; Boedo, J. A.; Calabro, G.; Crisanti, F.; Innocente, P.; Maurizio, R.; Pericoli, V.; Sheikh, U.; Spolare, M.; Vianello, N.; the TCV Team; the EUROfusion MST1 Team

    2017-12-01

    Research towards a plasma exhaust solution for a fusion power plant aims at validating edge physics models, strengthening predictive capabilities and improving the divertor configuration. The TCV tokamak is extensively used to investigate the extent that geometric configuration modifications can affect plasma exhaust performance. Recent TCV experiments continue previous detachment studies of Ohmically heated L-mode plasmas in standard single-null configurations, benefitting from a range of improved diagnostic capabilities. Studies were extended to nitrogen seeding and an entire suite of alternative magnetic configurations, including flux flaring towards the target (X divertor), increasing the outer target radius (Super-X) and movement of a secondary x-point inside the vessel (X-point target) as well as the entire range of snowflake configurations. Nitrogen seeding into a snowflake minus configuration demonstrated a regime with strong radiation in the large region between the two x-points, confirming EMC3-Eirene simulations, and opening a promising path towards highly radiating regimes with limited adverse effects on core performance.

  19. Children's Exhaustive Readings of Questions

    Science.gov (United States)

    Cremers, Alexandre; Tieu, Lyn; Chemla, Emmanuel

    2017-01-01

    Questions, just like plain declarative sentences, can give rise to multiple interpretations. As discussed by Spector & Egré (2015), among others, questions embedded under know are ambiguous between "weakly exhaustive" (WE), "intermediate exhaustive" (IE), and "strongly exhaustive" (SE) interpretations (for…

  20. 46 CFR 52.25-20 - Exhaust gas boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Exhaust gas boilers. 52.25-20 Section 52.25-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-20 Exhaust gas boilers. Exhaust gas boilers with a maximum allowable working pressure...

  1. Anesthesiologists work-related exhaustion: A comparison study with other hospital employees

    Directory of Open Access Journals (Sweden)

    Waleed Riad

    2011-01-01

    Full Text Available Background: Anesthesia is a demanding occupation due to long working hours, sustained vigilance, unpredictability of stressful situation, fear of litigation, competence, and production pressure. Work-related exhaustion can lead to several physical and psychological symptoms and delay decision making. The aim of this study was to evaluate how different work conditions affect personnel exhaustion by studying a sample of anesthesiologists comparing them with ophthalmologists and ancillary hospital staff Methods: One hundred fifty persons divided into three equal groups (50 each were invited to participate in this study. Subjects were asked to answer two self report questionnaires: The Multidimensional Fatigue Inventory (MFI-20 and General Health Questionnaire (GHQ-12 which used to assess work related exhaustion and mental health, respectively. Results: Multidimensional Fatigue Inventory scale (MFI 20 and General Health Questionnaire (GHQ 12 were significantly higher in anesthesiologists than in other groups ( P = 0.001. Different aspects of work-related exhaustion showed that general, physical and mental fatigue were significantly higher in anesthesiologists ( P = 0.002 and 0.001, respectively. Reduced activity and reduced motivation were also higher in anesthesiologists compare to the other groups ( P = 0.005 and 0.001, respectively. Conclusion: Work-related exhaustion under the current study is more obvious among anesthesiologists. Ophthalmologist and ancillary hospital employees felt that they had less stress at their work.

  2. Contextualizing Emotional Exhaustion and Positive Emotional Display : The Signaling Effects of Supervisors' Emotional Exhaustion and Service Climate

    NARCIS (Netherlands)

    Lam, Catherine K.; Huang, Xu; Janssen, Onne; Lam, K.C.

    In this study, we investigated how supervisors' emotional exhaustion and service climate jointly influence the relationship between subordinates' emotional exhaustion and their display of positive emotions at work. Using data from frontline sales employees and their immediate supervisors in a

  3. Morphofunctional evaluation of the testis, duration of spermatogenesis and spermatogenic efficiency in the Japanese fancy mouse (Mus musculus molossinus).

    Science.gov (United States)

    Costa, Guilherme M J; Leal, Marcelo C; França, Luiz R

    2017-08-01

    Japanese fancy mouse, mini mouse or pet mouse are common names used to refer to strains of mice that present with different colour varieties and coat types. Although many genetic studies that involve spotting phenotype based on the coat have been performed in these mice, there are no reports of quantitative data in the literature regarding testis structure and spermatogenic efficiency. Hence, in this study we researched testis function and spermatogenesis in the adult Japanese fancy mouse. The following values of 68 ± 6 mg and 0.94 ± 0.1% were obtained as mean testis weight and gonadosomatic index, respectively. In comparison with other investigated mice strains, the fancy mouse Leydig cell individual size was much smaller, resulting in higher numbers of these cells per gram of testis. As found for laboratory mice strains, as a result of the development of the acrosomic system, 12 stages of the seminiferous epithelium cycle have been described in this study. The combined frequencies of pre-meiotic and post-meiotic stages were respectively 24% and 64% and very similar to the laboratory mice. The more differentiated germ cell types marked at 1 h or 9 days after tritiated thymidine administration were preleptotene/leptotene and pachytene spermatocytes at the same stage (VIII). The mean duration of one spermatogenic cycle was 8.8 ± 0.01 days and the total length of spermatogenesis lasted 37.8 ± 0.01 days (4.5 cycles). A high number of germ cell apoptosis was evident during meiosis, resulting in lower Sertoli cell and spermatogenic efficiencies, when compared with laboratory mice strains.

  4. Induction of spermatogenesis and fertility in hypogonadotropic azoospermic men by intravenous pulsatile gonadotropin-releasing hormone (GnRH).

    Science.gov (United States)

    Blumenfeld, Z; Makler, A; Frisch, L; Brandes, J M

    1988-06-01

    Gonadotropin-releasing hormone (GnRH) has only recently become a helpful tool in the medication of hypogonadotropic hypogonadism (HH). Two azoospermic patients with HH who had previously been treated with hCG/hMG because of delayed puberty and each of whom had fathered a child after previous gonadotropin therapy were referred due to secondary failure of hCG/hMG treatment to induce spermatogenesis and fertility. A pulse study where blood was drawn every 15 minutes for LH, FSH and PRL RIAs was performed in each patient, and afterwards a bolus of i.v. GnRH was injected to assess gonadotropin responsiveness. A portable GnRH pump was connected to each patient so that it administered 5-20 micrograms of GnRH i.v. every 89 minutes. Spermatogenesis was first detected after 42 and 78 days respectively in the 2 treated HH men and 4 1/2 months from the start of treatment their wives became pregnant. No thrombophlebitis or other complications of the i.v. therapy occurred. In the case of the first patient, the semen was washed and concentrated and intra-uterine inseminations were carried out in an attempt to shorten the time needed to achieve fertility. The first pregnancy was successfully terminated at 38 weeks with the delivery of 2 heterozygotic normal male babies. The second pregnancy ended in spontaneous delivery of a healthy female. We conclude that i.v. pulsatile, intermittent GnRH administration is a safe, efficient and highly successful means of treating azoospermic men with HH.

  5. Noise study in laboratories with exhaust fans

    International Nuclear Information System (INIS)

    Shaikh, G.H.; Hashmi, R.; Shareef, A.

    2005-01-01

    Noise study has been carried out in 25 laboratories fitted with exhaust fans. We have studied A- Weighted equivalent sound pressure levels (dB(A) LAeJ and equivalent octave band sound pressure levels (dB L/sub eq/ in each of the laboratories surveyed. The data collected has been analyzed for Preferred Speech Interference Levels (PSIL). The results show that the interior noise levels in these laboratories vary from 59.6 to 72.2 dB(A) L/sub Aeq/, which are very high and much beyond the interior noise limits recommended for laboratories. Some ways and means to limit emission of high-level noise from exhaust fans are also discussed. (author)

  6. Rare earth metals for automotive exhaust catalysts

    International Nuclear Information System (INIS)

    Shinjoh, Hirohumi

    2006-01-01

    The usage of rare earth metals for automotive exhaust catalysts is demonstrated in this paper. Rare earth metals have been widely used in automotive catalysts. In particular, three-way catalysts require the use of ceria compounds as oxygen storage materials, and lanthana as both a stabilizer of alumina and a promoter. The application for diesel catalysts is also illustrated. Effects of inclusion of rare earth metals in automotive catalysts are discussed

  7. On Gas Dynamics of Exhaust Valves

    OpenAIRE

    Winroth, Marcus

    2017-01-01

    With increasing effects of global warming, efforts are made to make transportation in general more fuel efficient. When it comes to internal combustion engines, the most common way to improve fuel efficiency is through ‘downsizing’. Downsizing means that a smaller engine (with lower losses and less weight) performs the task of a larger engine. This is accomplished by fitting the smaller engine with a turbocharger, to recover some of the energy in the hot exhaust gases. Such engine systems nee...

  8. Chemical laser exhaust pipe design research

    Science.gov (United States)

    Sun, Yunqiang; Huang, Zhilong; Chen, Zhiqiang; Ren, Zebin; Guo, Longde

    2016-10-01

    In order to weaken the chemical laser exhaust gas influence of the optical transmission, a vent pipe is advised to emissions gas to the outside of the optical transmission area. Based on a variety of exhaust pipe design, a flow field characteristic of the pipe is carried out by numerical simulation and analysis in detail. The research results show that for uniform deflating exhaust pipe, although the pipeline structure is cyclical and convenient for engineering implementation, but there is a phenomenon of air reflows at the pipeline entrance slit which can be deduced from the numerical simulation results. So, this type of pipeline structure does not guarantee seal. For the design scheme of putting the pipeline contract part at the end of the exhaust pipe, or using the method of local area or tail contraction, numerical simulation results show that backflow phenomenon still exists at the pipeline entrance slit. Preliminary analysis indicates that the contraction of pipe would result in higher static pressure near the wall for the low speed flow field, so as to produce counter pressure gradient at the entrance slit. In order to eliminate backflow phenomenon at the pipe entrance slit, concerned with the pipeline type of radial size increase gradually along the flow, flow field property in the pipe is analyzed in detail by numerical simulation methods. Numerical simulation results indicate that there is not reflow phenomenon at entrance slit of the dilated duct. However the cold air inhaled in the slit which makes the temperature of the channel wall is lower than the center temperature. Therefore, this kind of pipeline structure can not only prevent the leak of the gas, but also reduce the wall temperature. In addition, compared with the straight pipe connection way, dilated pipe structure also has periodic structure, which can facilitate system integration installation.

  9. Fronting and exhaustive exclusion in Biblical Hebrew

    African Journals Online (AJOL)

    Kate H

    48, 2017, 219-222 doi: 10.5774/48-0-292. Fronting and exhaustive exclusion in Biblical Hebrew. Christo H. J. van der Merwe. Department of Ancient Studies, University of Stellenbosch, South ... Merwe, Naudé and Kroeze 2017: 491-493). .... “And I will give him to the Lord all the days of his life, and no razor shall touch his.

  10. Validation of Karolinska Exhaustion Scale: psychometric properties of a measure of exhaustion syndrome.

    Science.gov (United States)

    Saboonchi, Fredrik; Perski, Aleksander; Grossi, Giorgio

    2013-12-01

    The syndrome of exhaustion is currently a medical diagnosis in Sweden. The description of the syndrome largely corresponds to the suggested core component of burnout, that is exhaustion. Karolinska Exhaustion Scale (KES) has been constructed to provide specific assessment of exhaustion in clinical and research settings. The purpose of the present study was to examine the psychometric properties of this scale in its original and revised versions by examining the factorial structure and measures of convergent and discriminant validity. Data gathered from two independent samples (n1 = 358 & n2 = 403) consisting of patients diagnosed with 'reaction to severe stress, and adjustment disorder' were subjected to confirmatory factor analysis. The study's instruments were Karolinska Exhaustion Scale and Shirom Melam Burnout Measure. Correlation analyses were employed to follow up the established factorial structure of the scale. The study was ethically approved by Karolinska Institute regional ethic committee. The findings demonstrated adequate fit of the data to the measurement model provided by the revised version of KES Limitations: The main limitation of the present study is the lack of a gold standard of exhaustion for direct comparison with KES. (KES-26) and partially supported convergent validity and discriminant validity of the scale. The demonstrated psychometric properties of KES-26 indicate sound construct validity for this scale encouraging use of this scale in assessment of exhaustion. The factorial structure of KES-26 may also be used to provide information concerning possible different clinical profiles. © 2012 The Authors Scandinavian Journal of Caring Sciences © 2012 Nordic College of Caring Science.

  11. Particle and Power Exhaust in EAST

    Science.gov (United States)

    Wang, Liang; Ding, Fang; Yu, Yaowei; Gan, Kaifu; Liang, Yunfeng; Xu, Guosheng; Xiao, Bingjia; Sun, Youwen; Luo, Guangnan; Gong, Xianzu; Hu, Jiansheng; Li, Jiangang; Wan, Baonian; Maingi, Rajesh; Guo, Houyang; Garofalo, Andrea; EAST Team

    2017-10-01

    A total power injection up to 0.3GJ has been achieved in EAST long pulse USN operation with ITER-like water-cooling W-monoblock divertor, which has steady-state power exhaust capability of 10 MWm-2. The peak temperature of W target saturated at t = 12 s to the value T 500oC and a heat flux 3MWm-2was maintained. Great efforts to reduce heat flux and accommodate particle exhaust simultaneously have been made towards long pulse of 102s time scale. By exploiting the observation of Pfirsch-Schlüter flow direction in the SOL, the Bt direction with Bx ∇B away from the W divertor (more particles favor outer target in USN) was adopted along with optimizing the strike point location near the pumping slot, to facilitate particle and impurity exhaust with the top cryo-pump. By tailoring the 3D divertor footprint through edge magnetic topology change, the heat load was dispersed widely and thus peak heat flux and W sputtering was well controlled. Active feedback control of total radiative power with neon seeding was achieved within frad = 17-35%, exhibiting further potential for heat flux reduction with divertor and edge radiation. Other heat flux handling techniques, including quasi snowflake configuration, will also be presented.

  12. Exhaust gas recirculation apparatus for internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Shigemori, M; Eguchi, N

    1975-01-07

    An exhaust gas recirculation device to reduce nitrogen oxides emission from internal combustion engines is described. The recirculation is achieved by employing a tube connecting between the exhaust pipe and intake tube. A throttle valve is installed within the exhaust pipe between the muffler and recirculation tube, and regulated by exhaust gas temperature. Whenever the gas temperature is high, the valve closes and increases the gas flow to the intake tube. A temperature sensor is installed within the exhaust pipe and controls a solenoid or magnetic air valve linking to the throttle valve through a relay. The recirculation tube can be cooled by a fan to improve the engine power.

  13. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  14. Engine with exhaust gas recirculation system and variable geometry turbocharger

    Science.gov (United States)

    Keating, Edward J.

    2015-11-03

    An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.

  15. Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity.

    Science.gov (United States)

    Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S; Soya, Hideaki

    2017-06-13

    Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.

  16. EGNAS: an exhaustive DNA sequence design algorithm

    Directory of Open Access Journals (Sweden)

    Kick Alfred

    2012-06-01

    Full Text Available Abstract Background The molecular recognition based on the complementary base pairing of deoxyribonucleic acid (DNA is the fundamental principle in the fields of genetics, DNA nanotechnology and DNA computing. We present an exhaustive DNA sequence design algorithm that allows to generate sets containing a maximum number of sequences with defined properties. EGNAS (Exhaustive Generation of Nucleic Acid Sequences offers the possibility of controlling both interstrand and intrastrand properties. The guanine-cytosine content can be adjusted. Sequences can be forced to start and end with guanine or cytosine. This option reduces the risk of “fraying” of DNA strands. It is possible to limit cross hybridizations of a defined length, and to adjust the uniqueness of sequences. Self-complementarity and hairpin structures of certain length can be avoided. Sequences and subsequences can optionally be forbidden. Furthermore, sequences can be designed to have minimum interactions with predefined strands and neighboring sequences. Results The algorithm is realized in a C++ program. TAG sequences can be generated and combined with primers for single-base extension reactions, which were described for multiplexed genotyping of single nucleotide polymorphisms. Thereby, possible foldback through intrastrand interaction of TAG-primer pairs can be limited. The design of sequences for specific attachment of molecular constructs to DNA origami is presented. Conclusions We developed a new software tool called EGNAS for the design of unique nucleic acid sequences. The presented exhaustive algorithm allows to generate greater sets of sequences than with previous software and equal constraints. EGNAS is freely available for noncommercial use at http://www.chm.tu-dresden.de/pc6/EGNAS.

  17. A study of automobile exhaust noise preferences

    Science.gov (United States)

    Haire, Jay B.; Carney, Melinda J.; Cheenne, Dominique J.

    2005-04-01

    A study was conducted to investigate the relationship between preferences in automobile exhaust noise and the demographic factors of a listening jury. Noise samples of four different vehicles were recorded at idle as well as at 3000 RPM, and 1/3 octave sound spectra were acquired simultaneously. The recordings were presented to the jury using headphones and a preference survey was administered. Zwicker loudness was computed for all samples. Demographic factors such as gender, age, current and future vehicle ownership, were correlated to listening preferences, and unforeseen results were found, especially in regards to sport utility vehicles (SUV).

  18. Deletion of the pluripotency-associated Tex19.1 gene causes activation of endogenous retroviruses and defective spermatogenesis in mice

    DEFF Research Database (Denmark)

    Ollinger, Rupert; Childs, Andrew J; Burgess, Hannah M

    2008-01-01

    . During male spermatogenesis, Tex19.1 expression is highest in mitotic spermatogonia and diminishes as these cells differentiate and progress through meiosis. In pluripotent stem cells, Tex19.1 expression is also downregulated upon differentiation. However, it is not clear whether Tex19.1 has an essential...... spermatogenesis. Immunostaining and histological analysis revealed defects in meiotic chromosome synapsis, the persistence of DNA double-strand breaks during meiosis, and a loss of post-meiotic germ cells in the testis. Furthermore, expression of a class of endogenous retroviruses is upregulated during meiosis...... in the Tex19.1(-/-) testes. Increased transposition of endogenous retroviruses in the germline of Tex19.1(-/-) mutant mice, and the concomitant increase in DNA damage, may be sufficient to disrupt the normal processes of recombination and chromosome synapsis during meiosis and cause defects...

  19. Effect of EGR on the exhaust gas temperature and exhaust opacity ...

    Indian Academy of Sciences (India)

    In diesel engines, NOx formation is a highly temperature-dependent phenomenon and takes place when the temperature in the combustion chamber exceeds 2000 K. Therefore, in order to reduce NOx emissions in the exhaust, it is necessary to keep peak combustion temperatures under control. One simple way of ...

  20. The long-term effects of FSH and triiodothyronine administration during the pubertal period on Connexin 43 expression and spermatogenesis efficiency in adult rats.

    Science.gov (United States)

    Marchlewska, Katarzyna; Slowikowska-Hilczer, Jolanta; Walczak-Jedrzejowska, Renata; Oszukowska, Elzbieta; Filipiak, Eliza; Kula, Krzysztof

    2015-04-01

    Follicle-stimulating hormone (FSH) and triiodothyronine (T3) are known regulatory factors of spermatogenesis initiation. Hyperstimulation of both hormones evokes regressional changes in connexin 43 expression and the seminiferous epithelium in young rats during testicular maturation. However, separate treatments with T3 reduce Sertoli cell number, which seems to be closely connected with the maturation of connexin 43 gap junctions. FSH elevates Sertoli cell number and function, but this effect may take place regardless of the presence of connexin 43-dependent intercellular communication. The aim of the study was to evaluate the later effects of such treatments. Newborn, male Wistar rats were divided randomly into experimental groups receiving daily subcutaneous injections of either 7.5 IU/animal FSH, or 100 mg/kg b.w. T3, or both substances or the same volume of vehicle (control group) until day 15 of life. The animals were sacrificed on day 50. Morphometric analysis and immunohistochemical reactions were performed using antibodies against Vimentin, Proliferating Cell Nuclear Antigen and Connexin 43 in the testis. Sertoli cell count, efficiency of spermatogenesis, and hormonal pattern were examined. Disturbances in the connexin 43 expression reduced the number of Sertoli cells, the efficiency of spermatogenesis and impaired endocrine function of testes in adult rats treated with FSH and T3 during puberty. Stimulation with FSH alone increased Sertoli cell number, but was associated with a negative effect on cell-to-cell connexin 43-dependent communication, with a consequential reduction of spermatogenesis efficiency. J. Exp. Zool. 323A: 256-265, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  1. High-Throughput Screening for Spermatogenesis Candidate Genes in the AZFc Region of the Y Chromosome by Multiplex Real Time PCR Followed by High Resolution Melting Analysis

    OpenAIRE

    Alechine, Evguenia; Corach, Daniel

    2014-01-01

    Microdeletions in the AZF region of the Y chromosome are among the most frequent genetic causes of male infertility, although the specific role of the genes located in this region is not fully understood. AZFa and AZFb deletions impair spermatogenesis since no spermatozoa are found in the testis. Deletions of the AZFc region, despite being the most frequent in azoospermic patients, do not correlate with spermatogenic failure. Therefore, the aim of this work was to develop a screening method t...

  2. High-throughput screening for spermatogenesis candidate genes in the AZFc region of the Y chromosome by multiplex real time PCR followed by high resolution melting analysis

    OpenAIRE

    Alechine, Evguenia; Corach, Daniel

    2017-01-01

    Microdeletions in the AZF region of the Y chromosome are among the most frequent genetic causes of male infertility, although the specific role of the genes located in this region is not fully understood. AZFa and AZFb deletions impair spermatogenesis since no spermatozoa are found in the testis. Deletions of the AZFc region, despite being the most frequent in azoospermic patients, do not correlate with spermatogenic failure. Therefore, the aim of this work was to develop a screening method t...

  3. Specific down-regulation of spermatogenesis genes targeted by 22G RNAs in hybrid sterile males associated with an X-Chromosome introgression.

    Science.gov (United States)

    Li, Runsheng; Ren, Xiaoliang; Bi, Yu; Ho, Vincy Wing Sze; Hsieh, Chia-Ling; Young, Amanda; Zhang, Zhihong; Lin, Tingting; Zhao, Yanmei; Miao, Long; Sarkies, Peter; Zhao, Zhongying

    2016-09-01

    Hybrid incompatibility (HI) prevents gene flow between species, thus lying at the heart of speciation genetics. One of the most common HIs is male sterility. Two superficially contradictory observations exist for hybrid male sterility. First, an introgression on the X Chromosome is more likely to produce male sterility than on autosome (so-called large-X theory); second, spermatogenesis genes are enriched on the autosomes but depleted on the X Chromosome (demasculinization of X Chromosome). Analysis of gene expression in Drosophila hybrids suggests a genetic interaction between the X Chromosome and autosomes that is essential for male fertility. However, the prevalence of such an interaction and its underlying mechanism remain largely unknown. Here we examine the interaction in nematode species by contrasting the expression of both coding genes and transposable elements (TEs) between hybrid sterile males and its parental nematode males. We use two lines of hybrid sterile males, each carrying an independent introgression fragment from Caenorhabditis briggsae X Chromosome in an otherwise Caenorhabditis nigoni background, which demonstrate similar defects in spermatogenesis. We observe a similar pattern of down-regulated genes that are specific for spermatogenesis between the two hybrids. Importantly, the down-regulated genes caused by the X Chromosome introgressions show a significant enrichment on the autosomes, supporting an epistatic interaction between the X Chromosome and autosomes. We investigate the underlying mechanism of the interaction by measuring small RNAs and find that a subset of 22G RNAs specifically targeting the down-regulated spermatogenesis genes is significantly up-regulated in hybrids, suggesting that perturbation of small RNA-mediated regulation may contribute to the X-autosome interaction. © 2016 Li et al.; Published by Cold Spring Harbor Laboratory Press.

  4. The anti-oxidant effects of ginger and cinnamon on spermatogenesis dys-function of diabetes rats.

    Science.gov (United States)

    Khaki, Arash; Khaki, Amir Afshin; Hajhosseini, Laleh; Golzar, Farhad Sadeghpour; Ainehchi, Nava

    2014-01-01

    Diabetes rats have been linked to reproductive dysfunction and plant medicine has been shown to be effective in its treatment. Antioxidants have distinctive effects on spermatogenesis, sperm biology and oxidative stress, and changes in anti-oxidant capacity are considered to be involved in the pathogenesis of chronic diabetes mellitus. Ginger and cinnamon are strong anti-oxidants and have been shown to reduce oxidative stress in the long-term treatment of streptozotocin (STZ)-induced diabetes in animal models. The present study examined the influence of combined ginger and cinnamon on spermatogenesis in STZ-induced diabetes in male Wistar rats. Animals (n = 80) were allocated randomly into eight groups, 10 each: Group 1: Control rats given only 5cc Normal saline (0.9% NaCl) daily;Group2: rats received ginger (100mg/kg/rat) daily; Group 3: rats received cinnamon (75mg/kg) daily; Group 4: rats received ginger and cinnamon, (100mg/kg/rat ginger and 75mg/kg cinnamon) daily; Group 5: Diabetic control rats received only normal saline. Group 6: Diabetic rats received 100mg/kg/day ginger; Group 7: Diabetic rats received 75mg /kg/ day cinnamon; Group 8: Diabetic rats received ginger and cinnamon (100mg/kg/day and 75mg/kg /day). Diabetes was induced with 55 mg/kg, single intra-peritoneal injection of STZ in all groups. At the end of the experiment (56th day), blood samples were taken for determination of testosterone, LH,FSH, total anti-oxidant capacity, and levels of malondialdehyde, SOD, Catalase and GPX. All rats were euthanized, testes were dissected out and spermatozoa were collected from the epididymis for analysis. Sperm numbers, percentages of sperm viability and motility, and total serum testosterone increased in ginger and cinnamon and combined ginger and cinnamon treated diabetic rats compared with control groups. Serum testosterone, LH and FSH were higher compared to control group and also serum anti-oxidants (TAC, SOD, GPX and catalase) all were increased at the

  5. Aircraft exhaust aerosol formation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R C; Miake-Lye, R C; Anderson, M R; Kolb, C E [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

    1998-12-31

    Aerosol formation and growth in the exhaust plume of the ATTAS aircraft at an altitude of approximately 9 km, burning fuels with 2 ppmm sulfur (`low`) and 266 ppmm (`high`) sulfur has been modeled using an aerosol dynamics model for nucleation, vapor condensation and coagulation, coupled to a 2-dimensional, axisymmetric flow code to treat plume dilution and turbulent mixing. For both the `low` and `high` sulfur fuels, approximately 60% of the available water had condensed within the first 200 m downstream of the exhaust exit. The contrail particle diameters ranged between 0.4 to 1.6 {mu}m. However, the size distributions as a function of radial position for the `low` sulfur plume were broader than the corresponding distributions for the `high` sulfur plume. The model results indicate for a fuel sulfur mass loading of 2 ppmm, sulfuric acid remains a viable activating agent and that the differences in the contrail particle size distributions for sulfur mass loadings between 2 ppmm and 260 ppmm would be difficult to detect. (author) 12 refs.

  6. Local Pain Dynamics during Constant Exhaustive Exercise.

    Directory of Open Access Journals (Sweden)

    Agne Slapsinskaite

    Full Text Available The purpose of this study was to delineate the topological dynamics of pain and discomfort during constant exercise performed until volitional exhaustion. Eleven physical education students were tested while cycling and running at a "hard" intensity level (e.g., corresponding to Borg's RPE (6-20 = 15. During the tests, participants reported their discomfort and pain on a body map every 15s. "Time on task" for each participant was divided into five equal non-overlapping temporal windows within which their ratings were considered for analysis. The analyses revealed that the number of body locations with perceived pain and discomfort increased throughout the five temporal windows until reaching the mean (± SE values of 4.2 ± 0.7 and 4.1 ± 0.6 in cycling and running, respectively. The dominant locations included the quadriceps and hamstrings during cycling and quadriceps and chest during running. In conclusion, pain seemed to spread throughout the body during constant cycling and running performed up to volitional exhaustion with differences between cycling and running in the upper body but not in the lower body dynamics.

  7. On the exhaust of electromagnetic drive

    Directory of Open Access Journals (Sweden)

    Patrick Grahn

    2016-06-01

    Full Text Available Recent reports about propulsion without reaction mass have been met on one hand with enthusiasm and on the other hand with some doubts. Namely, closed metal cavities, when fueled with microwaves, have delivered thrust that could eventually maintain satellites on orbits using solar power. However, the measured thrust appears to be without any apparent exhaust. Thus the Law of Action-Reaction seems to have been violated. We consider the possibility that the exhaust is in a form that has so far escaped both experimental detection and theoretical attention. In the thruster’s cavity microwaves interfere with each other and invariably some photons will also end up co-propagating with opposite phases. At the destructive interference electromagnetic fields cancel. However, the photons themselves do not vanish for nothing but continue in propagation. These photon pairs without net electromagnetic field do not reflect back from the metal walls but escape from the resonator. By this action momentum is lost from the cavity which, according to the conservation of momentum, gives rise to an equal and opposite reaction. We examine theoretical corollaries and practical concerns that follow from the paired-photon conclusion.

  8. Aircraft exhaust aerosol formation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Miake-Lye, R.C.; Anderson, M.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

    1997-12-31

    Aerosol formation and growth in the exhaust plume of the ATTAS aircraft at an altitude of approximately 9 km, burning fuels with 2 ppmm sulfur (`low`) and 266 ppmm (`high`) sulfur has been modeled using an aerosol dynamics model for nucleation, vapor condensation and coagulation, coupled to a 2-dimensional, axisymmetric flow code to treat plume dilution and turbulent mixing. For both the `low` and `high` sulfur fuels, approximately 60% of the available water had condensed within the first 200 m downstream of the exhaust exit. The contrail particle diameters ranged between 0.4 to 1.6 {mu}m. However, the size distributions as a function of radial position for the `low` sulfur plume were broader than the corresponding distributions for the `high` sulfur plume. The model results indicate for a fuel sulfur mass loading of 2 ppmm, sulfuric acid remains a viable activating agent and that the differences in the contrail particle size distributions for sulfur mass loadings between 2 ppmm and 260 ppmm would be difficult to detect. (author) 12 refs.

  9. Exhaust purification with on-board ammonia production

    Science.gov (United States)

    Robel, Wade J.; Driscoll, James J.; Coleman, Gerald N.; Knox, Kevin J.

    2009-06-30

    A power source is provided for use with selective catalytic reduction systems for exhaust-gas purification. The power source includes a first cylinder group with a first air-intake passage and a first exhaust passage, and a second cylinder group with a second air-intake passage and a second exhaust passage. The second air-intake passage is fluidly isolated from the first air-intake passage. A fuel-supply device may be configured to supply fuel into the first exhaust passage, and a catalyst may be disposed downstream of the fuel-supply device to convert at least a portion of the exhaust stream in the first exhaust passage into ammonia.

  10. Ultrastructural changes during spermatogenesis, biochemical and hormonal evidences of testicular toxicity caused by TBT in freshwater prawn Macrobrachium rosenbergii (De Man, 1879).

    Science.gov (United States)

    Revathi, Peranandam; Iyapparaj, Palanisamy; Vasanthi, Lourduraj Arockia; Munuswamy, Natesan; Krishnan, Muthukalingan

    2014-10-01

    The present investigation documents the impact of tributyltin (TBT) on the ultrastructural variation of spermatogenesis in freshwater prawn Macrobrachium rosenbergii. The environmentally realistic concentration of TBT can cause damages to the endocrine and reproductive physiology of crustaceans. In this context, three concentrations viz. 10, 100, and 1000 ng/L were selected and exposed to prawns for 90 days. The TBT exposed prawn exhibited decrease the reproductive activity as evidenced by sperm count and sperm length compared to control. Histopathological results revealed the retarded testicular development, abnormal structure of seminiferous tubule, decrease in the concentration of spermatozoa, diminution of seminiferous tubule membrane, abundance of spermatocytes and vacuolation in testis of treated prawns. Ultrastructural study also confirmed the impairment of spermatogenesis in treated prawns. Furthermore, radioimmunoassay (RIA) clearly documented the reduction of testosterone level in TBT exposed groups. Thus, TBT substantially reduced the level of male sex hormone as well as biochemical constituents which ultimately led to impairment of spermatogenesis in the freshwater male prawn M. rosenbergii. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  11. The effects of increased testicular temperature on testis-specific isoform of Na+/K+ -ATPase in sperm and its role in spermatogenesis and sperm function.

    Science.gov (United States)

    Thundathil, J C; Rajamanickam, G D; Kastelic, J P; Newton, L D

    2012-08-01

    Impaired testicular thermoregulation is commonly implicated in abnormal spermatogenesis and impaired sperm function in animals and humans, with outcomes ranging from subclinical infertility to sterility. Bovine testes must be maintained 4-5 °C below body-core temperature for normal spermatogenesis. The effects of elevated testicular temperature have been extensively studied in cattle using a scrotal insulation model, which results in abnormal spermatogenesis and impaired sperm morphology and function. Using this model and proteomic approaches, we compared normal and abnormal sperm (from the same bulls) to elucidate the molecular basis of impaired function. We identified a cohort of sperm functional proteins differentially expressed between normal vs abnormal sperm, including a testis-specific isoform of Na(+) /K(+) -ATPase. In addition to its role as a sodium pump regulating sperm motility, Na(+) /K(+) -ATPase is also involved as a signalling molecule during sperm capacitation. In conclusion, because of its involvement in regulation of sperm function, this protein has potential as a fertility marker. Furthermore, comparing normal vs abnormal sperm (induced by scrotal insulation) is a useful model for identifying proteins regulating sperm function. © 2012 Blackwell Verlag GmbH.

  12. Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Health Risk Management, China Medical University, Taichung, Taiwan (China); Lin, Kuo-Hsiung [Department of Environmental Engineering and Science, Fooyin University, Kaohsiung, Taiwan (China)

    2014-01-15

    Highlights: • Recycling of waste printed circuit boards is an important issue. • Pyrolysis is an emerging technology for PCB treatment. • Emission factors of VOCs are determined for PCB pyrolysis exhaust. • Iron-Al{sub 2}O{sub 3} catalyst was employed for the exhaust control. -- Abstract: The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H{sub 2}, CH{sub 4}, CO{sub 2}, and NOx, were 60–115, 0.4–4.0, 1.1–10, 30–95, and 0–0.7 mg/g, corresponding to temperatures ranging from 200 to 500 °C. When the pyrolysis temperature was lower than 300 °C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400 °C. When VOC exhaust was flowed through the bed of Fe-impregnated Al{sub 2}O{sub 3}, the emission of ozone precursor VOCs could be reduced by 70–80%.

  13. Passive Sampling and Analysis of Naphthalene in Internal Combustion Engine Exhaust with Retracted SPME Device and GC-MS

    Directory of Open Access Journals (Sweden)

    Nassiba Baimatova

    2017-07-01

    Full Text Available Exhaust gases from internal combustion engines are the main source of urban air pollution. Quantification of Polycyclic aromatic hydrocarbons (PAHs in the exhaust gases is needed for emissions monitoring, enforcement, development, and testing of control technologies. The objective was to develop quantification of gaseous naphthalene in diesel engine exhaust based on diffusion-controlled extraction onto a retracted solid-phase microextraction (SPME fiber coating and analysis on gas chromatography-mass spectrometry (GC-MS. Extraction of naphthalene with retracted fibers followed Fick’s law of diffusion. Extracted mass of naphthalene was proportional to Cg, t, Dg, T and inversely proportional to Z. Method detection limit (p = 0.95 was 11.5 ppb (0.06 mg·m−3 at t = 9 h, Z = 10 mm and T = 40 °C, respectively. It was found that the % mass extracted of naphthalene by SPME needle assembly depended on the type of fiber. Storage time at different temperatures did not affect analyte losses extracted by polydimethylsiloxane (PDMS 100 µm fiber. The developed method was tested on exhaust gases from idling pickup truck and tractor, and compared side-by-side with a direct injection of sampled exhaust gas method. Time-weighted average (TWA concentrations of naphthalene in exhaust gases from idling pickup truck and a tractor ranged from 0.08 to 0.3 mg·m−3 (15.3–53.7 ppb.

  14. Three-dimensional approach to exhaust gas energy analysis

    Science.gov (United States)

    Sekavčnik, M.; Ogorevc, T.; Katrašnik, T.; Rodman-Oprešnik, S.

    2012-06-01

    Presented work is based on an extensive CFD simulation of the exhaust stroke of a single-cylinder four-stroke internal combustion engine with the exhaust manifold attached. Since the dynamics of the exhaust flow are extremely 3D, an innovative approach to calculate the local entropy generation is developed and implemented in the discussed 3D numerical model. It allows temporal and spatial determination of critical regions and periods of entropy generation in the process with objective to reduce it.

  15. Effects of exhaust temperature on helicopter infrared signature

    International Nuclear Information System (INIS)

    Cheng-xiong, Pan; Jing-zhou, Zhang; Yong, Shan

    2013-01-01

    The effects of exhaust temperature on infrared signature (in 3–5 μm band) for a helicopter equipped with integrative infrared suppressor were numerically investigated. The internal flow of exhaust gas and the external downwash flow, as well as the mixing between exhaust gas and downwash were simulated by CFD software to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that for a helicopter with its integrative infrared suppressor embedded inside its rear airframe, the exhaust temperature has significant influence on the plume radiation characteristics, while the helicopter skin radiation intensity has little impact. When the exhaust temperature is raised from 900 K to 1200 K, the plume radiation intensity in 3–5 μm band is increased by about 100%, while the skin radiation intensity is increased by only about 5%. In general, the effects of exhaust temperature on helicopter infrared radiation intensity are mainly concentrated on plume, especially obvious for a lower skin emissivity case. -- Highlights: ► The effect of exhaust temperature on infrared signature for a helicopter is numerically investigated. ► The impact of exhaust temperature on helicopter skin temperature is revealed. ► The impact of exhaust temperature on plume radiation characteristics is revealed. ► The impact of exhaust temperature on helicopter skin radiation is revealed. ► The impact of exhaust temperature on helicopter's total infrared radiation intensity is revealed

  16. The important role of protamine in spermatogenesis and quality of sperm: A mini review

    Directory of Open Access Journals (Sweden)

    Muslim Akmal

    2016-09-01

    Conclusion: Our results of a study in mice confirmed that inhibin B injection caused a reduction in the expression of protamine 2 in cauda epididymis. It has implications in the decrease of motility, concentration, and spermatozoa viability so that it affects the fertilization ability and the number of child production.

  17. Removing method for radon gas exhausted from nuclear fuel material

    International Nuclear Information System (INIS)

    Kato, Kenji.

    1993-01-01

    A centrifugal separator is disposed in the midway of an exhaustion pipe of a nuclear fuel handling facility, and exhausted gases are sent into a rotational cylinder of the separator. Radon gases in the midway of exhaustion are separated from the exhaustion gases by the centrifugal force of the separator and caused to stagnate at the periphery of the circumferential wall of the rotational cylinder. At the same time, the exhaustion gases having the radon gases separated therefrom are exhausted from the periphery of a rotational shaft of the rotational cylinder. Then, the radon gases stagnated in the rotational cylinder are decayed depending on the half-decay time. With such procedures, the radon gases can be removed continuously without discharging them to the outside. Further, it is preferred that an exhaustion blower or the like for putting the inside of the nuclear fuel handing facility to a negative pressure is disposed as in a conventional case. Further, a plurality of centrifugal separators may be disposed to exhaustion pipes, to remove radon gases in the exhaust gases by a multi stage way. Radon gases can be removed in a saved space with no requirement for exchange of adsorbents or temperature control. (T.M.)

  18. Two studies on the effects of small exhaust fans on indoor air quality: Field study of exhaust fans for mitigating indoor air quality problems; Indoor air quality, exhaust fan mitigation

    International Nuclear Information System (INIS)

    1987-07-01

    Overall, the findings show that exhaust fans basically provide small amounts of ventilation compensation. By monitoring the common indoor air pollutants (radon, formaldehyde, carbon monoxide, nitrogen dioxide, and water vapor), it was found that the quality of the indoor air was not adversely affected by the use of exhaust fans. Nor did their use provide any measurable or significant benefits since no improvement in air quality was ascertained. While exhaust fans of this small size did not increase radon, which is the contaminant of most concern, the researchers caution that operation of a larger fan or installation in a very tight home could result in higher levels because depressurization is greater. The daily energy consumption for use of these appliances during the heating season was calculated to be 1.5 kilowatt hours or approximately 3% of the energy consumption in the study homes. The information collected in this collaborative field study indicates that the use of these particular ventilation systems has no significant effect on indoor air quality

  19. Hepatoprotective Effects of Ixora parviflora Extract against Exhaustive Exercise-Induced Oxidative Stress in Mice

    Directory of Open Access Journals (Sweden)

    Chi-Chang Huang

    2013-09-01

    Full Text Available Ixora parviflora, a species of the Rubiaceae, is rich in polyphenols and flavonoids, and has been traditionally used as a folk medicine. An I. parviflora extract (IPE has great antioxidant activity in vitro, including a scavenging effect on superoxide radicals, reducing power, and ferrous ion-chelating ability. However, whether IPE is efficacious against oxidative damage in vivo is not known. The purpose of this study was to determine the protective effects of IPE treatment on hepatic oxidative stress and antioxidant defenses after exhaustive exercise in mice. Fifty male C57BL/6 mice (6 week old were randomly divided into five groups and designated a sedentary control with vehicle (C, and exhaustive exercise with vehicle (IPE0, low dosage (IPE10, medium dosage (IPE50 and high dosage (IPE100 of IPE at 0, 10, 50, and 100 mg/kg, respectively. After a single bout of exhaustive swimming exercise challenge, levels of blood ammonia and creatine kinase (CK, and hepatic superoxide dismutase (SOD protein expression, thiobarbituric acid-reactive substance (TBARS, and gp91phox, p22phox, and p47phox subunits of nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressions in the IPE0 group were significantly affected compared to those of the C group, but they were all significantly inhibited by the IPE treatments. Results of the present in vivo study in mice indicate that I. parviflora extract possesses antioxidative and hepatoprotective potential following exhaustive exercise.

  20. Role of snow and cold environment in the fate and effects of nanoparticles and select organic pollutants from gasoline engine exhaust.

    Science.gov (United States)

    Nazarenko, Yevgen; Kurien, Uday; Nepotchatykh, Oleg; Rangel-Alvarado, Rodrigo B; Ariya, Parisa A

    2016-02-01

    Exposure to vehicle exhaust can drive up to 70 % of excess lifetime cancer incidences due to air pollution in urban environments. Little is known about how exhaust-derived particles and organic pollutants, implicated in adverse health effects, are affected by freezing ambient temperatures and the presence of snow. Airborne particles and (semi)volatile organic constituents in dilute exhaust were studied in a novel low-temperature environmental chamber system containing natural urban snow under controlled cold environmental conditions. The presence of snow altered the aerosol size distributions of dilute exhaust in the 10 nm to 10 μm range and decreased the number density of the nanoparticulate (snow from 0.218 ± 0.014 to 0.539 ± 0.009 mg L(-1), and over 40 additional (semi)volatile organic compounds and a large number of exhaust-derived carbonaceous and likely organic particles were identified. The concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) increased from near the detection limit to 52.48, 379.5, 242.7, and 238.1 μg kg(-1) (± 10 %), respectively, indicating the absorption of exhaust-derived toxic organic compounds by snow. The alteration of exhaust aerosol size distributions at freezing temperatures and in the presence of snow, accompanied by changes of the organic pollutant content in snow, has potential to alter health effects of human exposure to vehicle exhaust.

  1. The effect of finasteride on spermatogenesis of Mesocricetus auratus Impacto da finasterida na espermatogênese do Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Dimas José Araújo Vidigal

    2008-06-01

    Full Text Available PURPOSE: To study the effect of finasteride on the spermatogenesis of adult Mesocricetus auratus. METHODS: Twenty adult hamsters were evaluated. The animals were one year-older, and were randomly divided in 2 different groups: control group with ten animals (n=10 and experimental group also with ten animals (n=10. The animals in the experimental group were shot 7.14 ng/mL (0.5mL of finasteride by 100mg/Kg, subcutaneously in the dorsal region three times per week during 90 days. This dose correspondes to 5mg of the drug used in adult men for the treatment of benign prostatic hyperplasia (BPH. After three months, the animals were anesthetized through association of 200mg/kg ketamine chloridrate and 2.5 mg/kg of diazepan and were dead through hypovolemia.. The testis removed along with the whole genitourinary apparel were fixed with 10% formalin and submitted to histological analisys by optical microscopy. The hematoxilin-eosin (HE method was used to stain the slides. RESULTS: The mean weight of animals in the control group before death was 129.0±18.8gr. The mean weight of animals in experimental group was 145.0±15.25gr. The mean age of animals in control group before death was 15.2±1.13 months. The mean age of animals in experimental group before death was 17.16±0.82 months. The mean difference in weight between both groups was not statistical significant (p=0.0514. The totality of animals in control group (100% presented no tubular alterations and showed no disturbancy in the spermatogenesis stages. Four animals (40% in the experimental group showed hypotrophy of the seminiferous tubules and six (60% showed normal spermatogenesis, however reduced compared to control group. There was statiscally significant difference (p=0.043 between the control and experimental group related to testicular alterations. CONCLUSION: The animals that were administered finasteride showed significant tubules atrophy and spermatogenesis reduction compared to

  2. Abnormal spermatogenesis following sodium fluoride exposure is associated with the downregulation of CREM and ACT in the mouse testis.

    Science.gov (United States)

    Wang, Chong; Chen, Yan; Manthari, Ram Kumar; Wang, Jundong

    2018-04-01

    cAMP response element modulator (CREM) is involved in regulating gene expression in normal spermatogenesis. The transcriptional activity of CREM is partly regulated by activator of CREM in the testis (ACT). To investigate the effects of different concentrations of sodium fluoride (NaF) on the gene and protein expression of CREM and ACT in the mouse testis, sexually mature male Kunming mice were exposed to 50, 100, or 150 mg/L NaF in their drinking water for 90 days. NaF reduced the sperm count and viability and increased the percentage of malformed sperm in a dose-dependent manner. The mRNA expression of CREM and ACT was markedly downregulated in the NaF-treated groups. Furthermore, immunohistochemistry revealed that CREM and ACT proteins were decreased significantly in the 50, 100, and 150 mg/L NaF-treated groups compared to the control group. These findings indicate that the decreased gene and protein expression of CREM and ACT in the testis is associated with an impairment of reproductive functions by NaF.

  3. Reticulate Evolution of the Rock Lizards: Meiotic Chromosome Dynamics and Spermatogenesis in Diploid and Triploid Males of the Genus Darevskia.

    Science.gov (United States)

    Spangenberg, Victor; Arakelyan, Marine; Galoyan, Eduard; Matveevsky, Sergey; Petrosyan, Ruzanna; Bogdanov, Yuri; Danielyan, Felix; Kolomiets, Oxana

    2017-05-24

    Knowing whether triploid hybrids resulting from natural hybridization of parthenogenetic and bisexual species are fertile is crucial for understanding the mechanisms of reticulate evolution in rock lizards. Here, using males of the bisexual diploid rock lizard species Darevskia raddei nairensis and Darevskia valentini and a triploid hybrid male Darevskia unisexualis × Darevskia valentini , we performed karyotyping and comparative immunocytochemistry of chromosome synapsis and investigated the distribution of RAD51 and MLH1 foci in spread spermatocyte nuclei in meiotic prophase I. Three chromosome sets were found to occur in cell nuclei in the D. unisexualis × D. valentini hybrid, two originating from a parthenogenetic D. unisexualis female and one from the D. valentini male. Despite this distorted chromosome synapsis and incomplete double-strand breaks repair in meiotic prophase I, the number of mismatch repair foci in the triploid hybrid was enough to pass through both meiotic divisions. The defects in synapsis and repair did not arrest meiosis or spermatogenesis. Numerous abnormal mature spermatids were observed in the testes of the studied hybrid.

  4. GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

    2003-08-24

    The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple

  5. Vital Exhaustion and Coronary Heart Disease Risk

    DEFF Research Database (Denmark)

    Frestad, Daria; Prescott, Eva

    2017-01-01

    INFO (1980 to July 2015; articles in English and published articles only), and bibliographies. Information on aim, study design, sample size, inclusion and exclusion criteria, assessment methods of psychological risk factors, and results of crude and adjusted regression analyses were abstracted independently......OBJECTIVES: The construct of vital exhaustion has been identified as a potential independent psychological risk factor for incident and recurrent coronary heart disease (CHD). Despite several decades of research, no systematic review or meta-analysis has previously attempted to collate.......22-1.85) for prospective studies, and 2.61 (95% CI = 1.66-4.10) for case-control studies using hospital controls. Risk of recurrent events in patients with CHD was 2.03 (95% CI = 1.54-2.68). The pooled adjusted risk of chronic heart failure in healthy populations was 1.37 (95% CI = 1.21-1.56), but this was based...

  6. Inerting Aircraft Fuel Systems Using Exhaust Gases

    Science.gov (United States)

    Hehemann, David G.

    2002-01-01

    Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

  7. Research on the Efficiency of Side Exhausters

    Directory of Open Access Journals (Sweden)

    Ina Tetsman

    2011-02-01

    Full Text Available The article focuses on the relevant technology of environmental protection which includes an effective collection, disposal and control of aerosol and gases contaminants removed from the evaporating surfaces of electroplating tanks. The task of the paper is to help with finding the new ways of collecting and disposing aerosol pollution and to reduce the quantity of equipment and service costs. The article also discusses pollution formation and sorts and performance of side draft and slot hoods for vapour capture. Besides, the paper deals with the formation of vapour over the tank and the features of benefit that depend on absorber‘s shape. Exhaust velocity and its dependencies are analyzed.Article in Lithuanian

  8. The Effect of Unemployment Insurance Exhaustion

    DEFF Research Database (Denmark)

    Lyk-Jensen, Stéphanie; Weatherall, Cecilie Dohlmann

    In this article we investigate how the long-term unemployed react to the threat of running out of unemployment insurance (UI) in a system in which other social benefits are available. The empirical analysis is based on very precise administrative records of unemployment spells in Denmark...... risk model to estimate the conditional probability of leaving unemployment to enter employment or receive other social benefits. We restrict our analysis to men aged 25-44 in 1998. Our results show that even for men having an initial UI entitlement for 4 years the threat of running out of UI indeed....... To identify the effect of UI exhaustion, we exploit the 1999 legislative change in the duration of benefit that progressively reduced regular UI entitlement from five to four years. According to time of entry into the UI system, all UI recipients had their potential UI period shortened. We use a competing...

  9. Reduction method of exhaust gas quantity

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Y.; Morishita, K.

    1975-02-08

    A cleaning method for automobile exhaust through contact with sintered oxide semiconductors consisting of tin, antimony, manganese, and palladium oxides is discussed. This device has a much higher efficiency and lasts longer than any similar device developed previously consisting of oxides of iron, manganese cobalt, nickel, aluminum, and other rare earth metals. This sintered oxide semiconductor device is composed of: tin oxide: 30 wt ratio, tin hydrogen oxide: 30 wt ratio, antimony oxide: 2 wt ratio, manganese chloride: 2 wt ratio, palladium chloride: 1 wt ratio, carbon powder: 4 wt ratio, and ammonium carbonate: 10 wt ratio, for example. This device converts 100 percent of carbon monoxide into carbon dioxide at 350 C. This compound provides oxygen to CO at higher temperatures and absorbs oxygen from air at normal temperatures. There is no effect on efficiency.

  10. Neural activation in stress-related exhaustion

    DEFF Research Database (Denmark)

    Gavelin, Hanna Malmberg; Neely, Anna Stigsdotter; Andersson, Micael

    2017-01-01

    The primary purpose of this study was to investigate the association between burnout and neural activation during working memory processing in patients with stress-related exhaustion. Additionally, we investigated the neural effects of cognitive training as part of stress rehabilitation. Fifty...... association between burnout level and working memory performance was found, however, our findings indicate that frontostriatal neural responses related to working memory were modulated by burnout severity. We suggest that patients with high levels of burnout need to recruit additional cognitive resources...... to uphold task performance. Following cognitive training, increased neural activation was observed during 3-back in working memory-related regions, including the striatum, however, low sample size limits any firm conclusions....

  11. Diesel Exhaust Exposure, Wheezing and Sneezing

    Science.gov (United States)

    2012-01-01

    The rising incidence of allergic disorders in developed countries is unexplained. Exposure to traffic related air pollutants may be an important cause of wheezing and asthma in childhood. Experimental evidence from human studies suggests that diesel exhaust particles, constituents of fine particulate matter less than 2.5 microns (PM2.5), may act to enhance IgE mediated aeroallergen sensitization and Th2 directed cytokine responses. To date, epidemiologic investigations indicate that children living in close proximity to heavily travelled roads are more likely to be atopic and wheeze. The Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) birth cohort study was initiated to test the hypothesis that early high exposure to traffic related air pollutants is associated with early aeroallergen sensitization and allergic respiratory phenotypes. Using an exposure cohort design, more than 700 infants born to atopic parents were recruited at age 1 living either less than 400 meters (high traffic pollutant exposure) or greater than 1,500 meters (low exposure) from a major road. Children were medically evaluated and underwent skin prick testing with aeroallergen at screening, and re-evaluated sequentially at ages 1, 2, 3, 4, and 7. In this study, both proximity and land use regression (LUR) models of traffic air pollutant exposure have been assessed. Proximity to stop and go traffic with large concentrations of bus and truck traffic predicted persistent wheezing during infancy. The LUR model estimated elemental carbon attributable to traffic (ECAT) as a proxy for diesel exhaust particulate exposure. High ECAT was significantly associated with wheezing at age 1 as well as persistent wheezing at age 3. High mold exposure predicted a well defined asthma phenotype at age 7. PMID:22754710

  12. Effects of Rocket Exhaust on Lunar Soil Reflectance Properties

    Science.gov (United States)

    Clegg, R. N.; Jolliff, B. L.; Robinson, M. S.; Hapke, B. W.; Plescia, J. B.

    2012-12-01

    The Apollo, Surveyor, and Luna spacecraft descent engine plumes affected the regolith at and surrounding their landing sites. Owing to the lack of rapid weathering processes on the Moon, surface alterations are still visible as photometric anomalies in Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images. These areas are interpreted as disturbance of the regolith by rocket exhaust during descent of the spacecraft, which we refer to as "blast zones" (BZs). The BZs consist of an area of lower reflectance (LR-BZ) compared to the surroundings that extends up to a few meters out from the landers, as well as a broader halo of higher reflectance (HR-BZ) that extends tens to hundreds of meters out from the landers. We use phase-ratio images for each landing site to determine the spatial extent of the disturbed regions and to quantify differences in reflectance and backscattering characteristics within the BZs compared to nearby undisturbed regolith. We also compare the reflectance changes and BZ dimensions at the Apollo sites with those at Luna and Surveyor sites. We seek to determine the effects of rocket exhaust in terms of erosion and particle redistribution, as well as the cause(s) of the reflectance variations, i.e., physical changes at the regolith surface. When approximated as an ellipse, the average Apollo BZ area is ~29,000 m2 (~175 ± 60 m by 200 ± 27 m) which is 10x larger than the average Luna BZ, and over 100x larger than the average Surveyor BZ. Moreover, BZ area scales roughly with lander mass (as a proxy for thrust). The LR-BZs are evident at the Apollo sites, especially where astronaut bioturbation has roughened the soil, leading to a 2-14% reduction in reflectance at ~30° phase. The LR-BZs at the Luna and Surveyor sites are less evident and may be mostly confined to the area below the landers. The average normalized reflectance in the HR-BZs for images with a 30° phase angle is 2-16% higher than in the undisturbed surrounding

  13. The Effect of Condensing Steam Turbine Exhaust Hood Body Geometry on Exhaust Performance Efficiency

    Science.gov (United States)

    Gribin, V. G.; Paramonov, A. N.; Mitrokhova, O. M.

    2018-06-01

    The article presents data from combined numerical and experimental investigations of the effect that the overall dimensions of the exhaust hood of a steam turbine with an underslung condenser has on the aerodynamic losses in the hood. Owing to the properly selected minimum permissible overall dimensions of the exhaust hood, more efficient operation of this turbine component is achieved, better vibration stability of the turbine set shaft line is obtained, and lower costs are required for arranging the steam turbine plant in the turbine building. Experiments have shown that the main overall dimensions of the hood body have a determining effect on the exhaust hood flow path profile and on its aerodynamic performance. Owing to properly selected ratios between the exhaust hood body main sizes without a diffuser, a total loss coefficient equal to approximately unity has been obtained. By using an axial-radial diffuser, the energy loss can be decreased by 30-40% depending on the geometrical parameters and level of velocities in the inlet section of a hood having the optimal overall dimensions. By using the obtained results, it becomes possible to evaluate the overall dimensions necessary for achieving the maximal aerodynamic hood efficiency and, as a consequence, to obtain better technical and economic indicators of the turbine plant as a whole already at the initial stage of its designing. If a need arises to select overall dimensions smaller than their optimal values, the increase of energy loss can be estimated using the presented dependences. The cycle of investigations was carried out on the experimental setups available in the fundamental research laboratory of the Moscow Power Engineering Institute National University's Department of Steam and Gas Turbines with due regard to the operating parameters and similarity criteria.

  14. Unemployment Benefit Exhaustion: Incentive Effects on Job-Finding Rates

    Science.gov (United States)

    Filges, Trine; Geerdsen, Lars Pico; Knudsen, Anne-Sofie Due; Jørgensen, Anne-Marie Klint

    2015-01-01

    Purpose: This systematic review studied the impact of exhaustion of unemployment benefits on the exit rate out of unemployment and into employment prior to benefit exhaustion or shortly thereafter. Method: We followed Campbell Collaboration guidelines to prepare this review, and ultimately located 12 studies for final analysis and interpretation.…

  15. 46 CFR 63.25-7 - Exhaust gas boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Exhaust gas boilers. 63.25-7 Section 63.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-7 Exhaust gas boilers. (a) Construction...

  16. Perceived social support and emotional exhaustion in HIV/AIDS ...

    African Journals Online (AJOL)

    Counsellors have been identified as a group of professionals at elevated risk of burnout in general and emotional exhaustion in particular. Considering the nature of the illness, ... the quality of the services they provide. Key words: Emotional exhaustion, perceived social support, burnout syndrome, demographic variables.

  17. 49 CFR 229.43 - Exhaust and battery gases.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Exhaust and battery gases. 229.43 Section 229.43... § 229.43 Exhaust and battery gases. (a) Products of combustion shall be released entirely outside the... conditions. (b) Battery containers shall be vented and batteries kept from gassing excessively. ...

  18. 30 CFR 36.25 - Engine exhaust system.

    Science.gov (United States)

    2010-07-01

    ... (see § 36.23(b)(2)). (3) In lieu of a space-place flame arrester, an exhaust-gas cooling box or... exhaust system for convenient, temporary attachment of a pressure gage at a point suitable for measuring the total back pressure in the system. The connection also shall be suitable for temporary attachment...

  19. Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

    Science.gov (United States)

    Taxell, Piia; Santonen, Tiina

    2017-08-01

    Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Experimental studies of impact of exhaust gas recirculation on the ...

    African Journals Online (AJOL)

    This paper considers the problem of reducing the nitrogen oxides emissions in exhaust gases (EG) of diesel engine by exhaust gas recirculation (EGR). Based on the carried out study the influence of EGR on technical-and-economic and environmental performance of a diesel engine was found as well as main directions of ...

  1. 40 CFR 1065.230 - Raw exhaust flow meter.

    Science.gov (United States)

    2010-07-01

    ... the following cases, you may use a raw exhaust flow meter signal that does not give the actual value... dew and pressure, p total at the flow meter inlet. Use these values in emission calculations according... CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.230 Raw exhaust...

  2. 40 CFR 86.1342-90 - Calculations; exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... exhaust sample in sampling solution, µg/ml. (vii) VAE = Volume of sampling solution for dilute exhaust... sampling solution, µg/ml. (xiii) VAA = Volume of sampling solution for dilution air formaldehyde sample, ml... paragraph (d)(3) of this section): Wet concentration = Kw × dry concentration. Where: (1)(i) For English...

  3. 30 CFR 36.26 - Composition of exhaust gas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Composition of exhaust gas. 36.26 Section 36.26... EQUIPMENT Construction and Design Requirements § 36.26 Composition of exhaust gas. (a) Preliminary engine... methane) is a satisfactory substitute for pure methane in these tests. (c) Coupling or adapter. The...

  4. Effect of diesel generator exhaust pollutants on growth of Vinca ...

    African Journals Online (AJOL)

    The effects of exhaust pollutants of generator on root and shoot length, root and shoot weight, number of leaflets and leaf area, leaf and total plant dry weight of Vinca rosea and Ruellia tuberosa were studied. The treatment of exhaust pollutants produced significant effects on root, shoot growth, number of leaflet and leaf ...

  5. Emotional exhaustion may trigger cut in working hours

    NARCIS (Netherlands)

    Koppes, L.

    2012-01-01

    Researchers in the Netherlands have been examining to what extent workers are modifying their hours to cope with high levels of work-related emotional exhaustion. Findings reveal that most full-time employees would prefer a cut in their hours, with those reporting emotional exhaustion wanting a

  6. 40 CFR 86.211-94 - Exhaust gas analytical system.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Exhaust gas analytical system. 86.211-94 Section 86.211-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.211-94 Exhaust gas...

  7. PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES

    Science.gov (United States)

    The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

  8. Effect of broccoli extract enriched diet on liver cholesterol oxidation in rats subjected to exhaustive exercise.

    Science.gov (United States)

    Cardenia, Vladimiro; Rodriguez-Estrada, Maria Teresa; Lorenzini, Antonello; Bandini, Erika; Angeloni, Cristina; Hrelia, Silvana; Malaguti, Marco

    2017-05-01

    The effect of broccoli extract (BE)-enriched diet was studied in order to evaluate its ability to counteract liver cholesterol oxidation products (COPs) induced by acute strenuous exercise in rats. Thirty-two female Wistar rats were randomly divided into four groups: control diet without exercise (C), BE-enriched diet without exercise (B), control diet with acute exhaustive exercise (S) and BE-enriched diet with acute exhaustive exercise (BS). The study lasted 45days and on the last day, rats of S and BS groups were forced to run until exhaustion on a treadmill. Glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT) and cholesterol oxidation products (COPs) were determined in liver. Exhaustive exercise was clearly responsible for tissue damage, as evidenced by the increase of lactate dehydrogenase (LDH) plasma activity in the S group. Moreover, the exercise protocol reduced CAT activity in liver, while it did not affect GST, GR and GPx. BE-enriched diet raised GST, GR and CAT activities in rats of BS group. The main COPs found were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol, cholestanetriol, 24-hydroxycholesterol and 27-hydroxycholesterol. The BE-enriched diet led to reduced cholesterol oxidation following exhaustive exercise; the highest level of COPs was found in the S group, whereas the BS rats showed the lowest amount. This study indicates that the BE-enriched diet increases antioxidant enzyme activities and exerts an antioxidant effect towards cholesterol oxidation in rat liver, suggesting the use of phytochemicals in the prevention of oxidative damage and in the modulation of the redox environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Literature review supporting assessment of potential radionuclides in the 291-Z exhaust ventilation

    International Nuclear Information System (INIS)

    Mahoney, L.A.; Ballinger, M.Y.; Jette, S.J.; Thomas, L.M. Glissmeyer, J.A.; Davis, W.E.

    1994-08-01

    This literature review was prepared to support a study conducted by Pacific Northwest Laboratory to assess the potential deposition and resuspension of radionuclides in the 291-Z ventilation exhaust building located in the 200 West Area of the US Department of Energy's Hanford Project near Richland, Washington. The filtered ventilation air from three of the facilities at the Plutonium Finishing Plant (PFP) complex are combined together in the 291-Z building before discharge through a common stack. These three facilities contributing filtered exhaust air to the discharge stream are (1) the PFP, also known as the Z-Plant or 234-5Z, (2) the Plutonium Reclamation Facility (PRF or 236-Z), and (3), the Waste Incinerator Building (WIB or 232-Z). The 291-Z building houses the exhaust fans that pull air from the 291-Z central collection plenum and exhausts the air to the stack. Section 2.0 of this report is a description of the physical characteristic of the ventilation system from the High Efficiency Particulate Air (HEPA) filters to the exhaust stack. A description of the processes performed in the facilities that are vented through 291-Z is given in Section 3.0. The description focuses on the chemical and physical forms of potential aerosols given off from the unit operations. A timeline of the operations and events that may have affected the deposition of material in the ventilation system is shown. Aerosol and radiation measurements taken in previous studies are also discussed. Section 4.0 discusses the factors that influence particle deposition and adhesion. Mechanisms of attachment and resuspension are covered with specific attention to the PFP ducts. Conclusions and recommendations are given in Section 5.0

  10. Explaining emotional exhaustion and work engagement : The role of job demands-resources and Type D personality

    NARCIS (Netherlands)

    van den Tooren, M.; Rutte, C.G.

    2016-01-01

    The aim of the current study was to show that Type D personality—a personality trait characterized by high levels of negative affectivity and high levels of social inhibition—can explain a significant amount of variance in emotional exhaustion and work engagement above and beyond the variance

  11. Engine with pulse-suppressed dedicated exhaust gas recirculation

    Science.gov (United States)

    Keating, Edward J.; Baker, Rodney E.

    2016-06-07

    An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.

  12. Infrared thermography application on predictive maintenance for exhaust fan motor

    International Nuclear Information System (INIS)

    I Wayan Widiana; Jakaria; Artadi Heru; Mulyono

    2013-01-01

    To determine the condition of the exhaust fan motor in terms of heat dissipation, predictive maintenance needs to be done. One way is to use infrared thermography. The method used is an infrared thermography with qualitative technique which the analysis focused on the distribution patterns of heat captured by the infrared camera. From measurement results expected to be obtained data of the heat distribution occurs in the motor exhaust fan so it can be given treatment or further improvements recommendations to avoid failure of the operation. Results of measurements on the motor exhaust fan 9 and the motor exhaust fan 10 indicates that there is excessive heat dissipation (over heating). The recommendation given is increasing the motor capacity of 11 kW to 18 kW with a consideration of the addition load on exhaust fan system and age of motor more than 22 years. (author)

  13. Dedicated exhaust gas recirculation control systems and methods

    Science.gov (United States)

    Sczomak, David P.; Narayanaswamy, Kushal; Keating, Edward J.

    2018-05-01

    An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

  14. Exhaust pressure pulsation observation from turbocharger instantaneous speed measurement

    Science.gov (United States)

    Macián, V.; Luján, J. M.; Bermúdez, V.; Guardiola, C.

    2004-06-01

    In internal combustion engines, instantaneous exhaust pressure measurements are difficult to perform in a production environment. The high temperature of the exhaust manifold and its pulsating character make its application to exhaust gas recirculation control algorithms impossible. In this paper an alternative method for estimating the exhaust pressure pulsation is presented. A numerical model is built which enables the exhaust pressure pulses to be predicted from instantaneous turbocharger speed measurements. Although the model is data based, a theoretical description of the process is also provided. This combined approach makes it possible to export the model for different engine operating points. Also, compressor contribution in the turbocharger speed pulsation is discussed extensively. The compressor contribution is initially neglected, and effects of this simplified approach are analysed.

  15. Affects and Affect Consciousness

    Science.gov (United States)

    MONSEN, JON T.; EILERTSEN, DAG ERIK; MELGÅRD, TROND; ØDEGÅRD, PÅL

    1996-01-01

    Affect consciousness (AC) was operationalized as degrees of awareness, tolerance, nonverbal expression, and conceptual expression of nine specific affects. A semistructured interview (ACI) and separate scales were developed to assess these aspects of affect integration. Their psychometric properties were preliminarily explored by having 20 former psychiatric outpatients complete the interview. Concurrent validity was assessed by using DSM-III-R Axis I and II diagnoses, the Health-Sickness Rating Scale, SCL-90-R, and several indexes from the Minnesota Multiphasic Personality Inventory. Satisfactory interrater reliability and high levels of internal consistency supported the construct validity of the measure. Results suggest the most meaningful use of this instrument is in measuring specific affect and overall AC. Clinically, the ACI has provided highly specific and relevant qualitative data for use in planning psychotherapeutic interventions. PMID:22700292

  16. Acceptance test procedure for SY Tank Farm replacement exhauster unit

    Energy Technology Data Exchange (ETDEWEB)

    Becken, G.W.

    1994-12-16

    The proper functioning of a new 241-SY Tank Farm replacement exhauster will be acceptance tested, to establish operability and to provide an operational baseline for the equipment. During this test, a verification of all of the alarm and control circuits associated with the exhaust, which provide operating controls and/or signals to local and remote alarm/annunciator panels, shall be performed. Test signals for sensors that provide alarms, warnings, and/or interlocks will be applied to verify that alarm, warning, and interlock setpoints are correct. Alarm and warning lights, controls, and local and remote readouts for the exhauster will be verified to be adequate for proper operation of the exhauster. Testing per this procedure shall be conducted in two phases. The first phase of testing, to verify alarm, warning, and interlock setpoints primarily, will be performed in the MO-566 Fab Shop. The second phase of testing, to verify proper operation and acceptable interface with other tank farm systems, will be conducted after the exhauster and all associated support and monitoring equipment have been installed in the SY Tank Farm. The exhauster, which is mounted on a skid and which will eventually be located in the SY tank farm, receives input signals from a variety of sensors mounted on the skid and associated equipment. These sensors provide information such as: exhauster system inlet vacuum pressure; prefilter and HEPA filter differential pressures; exhaust stack sampler status; exhaust fan status; system status (running/shut down); and radiation monitoring systems status. The output of these sensors is transmitted to the exhauster annunciator panel where the signals are displayed and monitored for out-of-specification conditions.

  17. Impact of lymphoma treatments on spermatogenesis and sperm deoxyribonucleic acid: a multicenter prospective study from the CECOS network.

    Science.gov (United States)

    Bujan, Louis; Walschaerts, Marie; Brugnon, Florence; Daudin, Myriam; Berthaut, Isabelle; Auger, Jacques; Saias, Jacqueline; Szerman, Ethel; Moinard, Nathalie; Rives, Nathalie; Hennebicq, Sylvianne

    2014-09-01

    To determine consequences of lymphoma treatments on sperm characteristics and sperm DNA, and to evaluate predictors of sperm recovery. Multicenter prospective longitudinal study of patients analyzed before treatment and after 3, 6, 12, and 24 months. University hospitals. Seventy-five Hodgkin lymphoma and non-Hodgkin lymphoma patients and a control group of 257 fertile men. Semen analyses, and sperm DNA and chromatin assessments. Comparisons of sperm characteristics before and after treatment. Patients already had altered sperm characteristics before lymphoma treatment, with no identified risk factor. Sperm count, total sperm count, motility, and vitality decreased after treatment, with lowest values at 3 and 6 months. Twelve months after treatment, mean sperm count recovered to pretreatment values after doxorubicin, bleomycin, vinblastine, darcarbacine (ABVD) or ABVD+radiotherapy, but not after doxorubicin, cyclophosphamide, vincristine, prednisone (CHOP) or mechlorethamine, oncovin, procarbazine, prednisone (MOPP) chemotherapies. It was noteworthy that 7% of patients remained azoospermic at 24 months. After 24 months, Kaplan-Meier estimates showed that more than 90% of patients will recover normal sperm count after ABVD or ABVD+radiotherapy vs. 61% for CHOP chemotherapies. In multivariate analyses including diagnosis and treatment protocol, only pretreatment total sperm count was related to recovery. Compared with a control group, lymphoma patients had higher sperm chromatin alterations and DNA fragmentation before any treatment. After treatment, DNA fragmentation assessed by TUNEL assay and sperm chromatin structure assay decreased from 3 and 6 months, respectively, while remaining higher than in the control group during follow-up. Lymphoma patients had altered sperm DNA and chromatin before treatment. Lymphoma treatment had damaging effects on spermatogenesis. These data on both the recovery period according to treatment modalities and the pre- and post

  18. Sodium metabisulfite-induced changes on testes, spermatogenesis and epididymal morphometric values in adult rats

    Directory of Open Access Journals (Sweden)

    Shahnaz Shekarforoush

    2015-12-01

    Full Text Available Background: Sulphites are widely used as a preservative and antioxidant additives in the food and pharmaceutical industries. Many types of biological and toxicological effects of sulphites in multiple organs of mammals have been shown in previous studies. Objective: The aim of this study was to investigate the effects of sodium metabisulfite (SMB on testicular function and morphometric values of epididymis in adult male Wistar rats. Materials and Methods: A total of 32 rats were randomly divided into four groups. The experimental groups received SMB at doses of 10 mg/kg (S10, 100mg/kg (S100, and 260 mg/kg (S260 while an equal volume of normal saline was administered to the control group via gavage. The rats were anaesthetized after 28 days and the left testis with the head of epididimis was excised following abdominal incision for histological observation using hematoxylin and eosin staining. Serum samples were collected for assay of testosterone level. The initial epididymis was analyzed for motility, morphology, and the number of sperms. Result: The results of this study showed that normal morphology, count, and motility of sperms and testosterone level were decreased in the SMB treated groups. In comparison with the control group, SMB resulted in a lower total number of spermatogonia, primary spermatocyte, spermatids, and Leydig cells. Conclusion: It is suggested that SMB decreases the sperm production and has the potential to affect the fertility adversely in male rats.

  19. LRGUK-1 is required for basal body and manchette function during spermatogenesis and male fertility.

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2015-03-01

    Full Text Available Male infertility affects at least 5% of reproductive age males. The most common pathology is a complex presentation of decreased sperm output and abnormal sperm shape and motility referred to as oligoasthenoteratospermia (OAT. For the majority of OAT men a precise diagnosis cannot be provided. Here we demonstrate that leucine-rich repeats and guanylate kinase-domain containing isoform 1 (LRGUK-1 is required for multiple aspects of sperm assembly, including acrosome attachment, sperm head shaping and the initiation of the axoneme growth to form the core of the sperm tail. Specifically, LRGUK-1 is required for basal body attachment to the plasma membrane, the appropriate formation of the sub-distal appendages, the extension of axoneme microtubules and for microtubule movement and organisation within the manchette. Manchette dysfunction leads to abnormal sperm head shaping. Several of these functions may be achieved in association with the LRGUK-1 binding partner HOOK2. Collectively, these data establish LRGUK-1 as a major determinant of microtubule structure within the male germ line.

  20. New catalysts for exhaust gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, M [Kemira Metalkat Oy, Oulu (Finland)

    1997-12-31

    Major challenge for future catalyst systems was to develop thermally more stable washcoats for close coupled operating conditions and for engines operating under high speed and load conditions. To design these future emission systems extensive research and development was undertaken to develop methods to disperse and stabilize the key catalytic materials for operation at much higher temperatures. Second priority was to design catalysts that are more effective under low temperature exhaust conditions and have improved oxygen storage properties in the washcoats. Incorporating new materials and modified preparation technology a new generation of metallic catalyst formulations emerged, those being trimetallic K6 (Pt:Pd:Rh and bimetallic K7) (Pd+Pd:Rh). The target was to combine the best property of Pt:Rh (good NO{sub x} reduction) with that of the good HC oxidation activity of Pd and to ensure that precious metal/support interactions were positively maintained. Both K6 and K7 concepts contain special catalyst structures with optimized washcoat performance which can be brick converter configuration. Improvement in light-off, thermal stability and transient performance with these new catalyst formulations have clearly been shown in both laboratory and vehicle testing. (author) (20 refs.)

  1. New catalysts for exhaust gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, M. [Kemira Metalkat Oy, Oulu (Finland)

    1996-12-31

    Major challenge for future catalyst systems was to develop thermally more stable washcoats for close coupled operating conditions and for engines operating under high speed and load conditions. To design these future emission systems extensive research and development was undertaken to develop methods to disperse and stabilize the key catalytic materials for operation at much higher temperatures. Second priority was to design catalysts that are more effective under low temperature exhaust conditions and have improved oxygen storage properties in the washcoats. Incorporating new materials and modified preparation technology a new generation of metallic catalyst formulations emerged, those being trimetallic K6 (Pt:Pd:Rh and bimetallic K7) (Pd+Pd:Rh). The target was to combine the best property of Pt:Rh (good NO{sub x} reduction) with that of the good HC oxidation activity of Pd and to ensure that precious metal/support interactions were positively maintained. Both K6 and K7 concepts contain special catalyst structures with optimized washcoat performance which can be brick converter configuration. Improvement in light-off, thermal stability and transient performance with these new catalyst formulations have clearly been shown in both laboratory and vehicle testing. (author) (20 refs.)

  2. Measurements of ion concentration in gasoline and diesel engine exhaust

    Science.gov (United States)

    Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

    The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

  3. Exhaustive Training Increases Uncoupling Protein 2 Expression and Decreases Bcl-2/Bax Ratio in Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    W. Y. Liu

    2013-01-01

    Full Text Available This work investigates the effects of oxidative stress due to exhaustive training on uncoupling protein 2 (UCP2 and Bcl-2/Bax in rat skeletal muscles. A total of 18 Sprague-Dawley female rats were randomly divided into three groups: the control group (CON, the trained control group (TC, and the exhaustive trained group (ET. Malondialdehyde (MDA, superoxide dismutase (SOD, xanthine oxidase (XOD, ATPase, UCP2, and Bcl-2/Bax ratio in red gastrocnemius muscles were measured. Exhaustive training induced ROS increase in red gastrocnemius muscles, which led to a decrease in the cell antiapoptotic ability (Bcl-2/Bax ratio. An increase in UCP2 expression can reduce ROS production and affect mitochondrial energy production. Thus, oxidative stress plays a significant role in overtraining.

  4. Impact of chronic exposure to gasoline automotive exhaust gases on some bio-markers affecting the hormonal sexual function, the kidney function and blood parameters, in the rat; Impact de l'exposition chronique aux gaz d'echappement d'origine automobile sur certains biomarqueurs touchant la fonction hormonale sexuelle male, la fonction renale et l'hemogramme chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Smaoui, M.; Ghorbel, F.; Boujelbene, M.; El Feki, A. [Faculte des Sciences de Sfax, Lab. d' Ecophysiologie Animale (Tunisia); Makni-Ayadi, F. [Faculte de Medecine de Sfax, Lab. de Biochimie (Tunisia)

    2000-09-01

    The automotive exhaust gases constitute an important source of urban pollution. The objective of this study is to explore, in the rat, the effects of repetitive exposure to gasoline automotive exhaust gases on the level variations of serum testosterone, blood lead, bone lead, blood carbon monoxide, on the kidney function and blood parameters. 200 rats inhaling a mixture of air and automotive exhaust gas (10/1, v/v), are distributed in 4 groups treated during 15, 30, 45 and 60 days. They are compared to non treated controls. Our results show a decrease of serum testosterone level. This result is the origin of a masculine sterility already demonstrated in our laboratory. This sterility seems to be reversible because polluted rats regain their sexual activity, 2 months after stopping of the pollutant treatment. An increase of the blood carbon monoxide level with a lead accumulation in blood and in the tail is noticed. Biochemical analyses show that glycaemia, urea, and creatininaemia increase in treated animals. The urinary rate of creatinine decreases. These results indicate kidney deficiency. Our results show also in treated animals an increase of the number of red blood corpuscles, of hematocrit, of the blood level of haemoglobin and of the VGM, and a decrease of the CGMH. The carbon monoxide and the lead detected in blood of the treated animals are the origin of these perturbations. In conclusion, our results show that gasoline automotive exhaust gas induces, in the rat, a decrease of serum testosterone level. The carbon monoxide and the lead present in the exhaust gas, and detected in blood and in the tail of the treated animals, are the origin of sexual, kidney and blood parameters perturbations. (author)

  5. Molecular mechanism of serine/threonine protein phosphatase 1 (PP1cα-PP1r7) in spermatogenesis of Toxocara canis.

    Science.gov (United States)

    Ma, Guang Xu; Zhou, Rong Qiong; Song, Zhen Hui; Zhu, Hong Hong; Zhou, Zuo Yong; Zeng, Yuan Qin

    2015-09-01

    Toxocariasis is one of the most important, but neglected, zoonoses, which is mainly caused by Toxocara canis. To better understand the role of serine/threonine protein phosphatase 1 (PP1) in reproductive processes of male adult T. canis, differential expression analysis was used to reveal the profiles of PP1 catalytic subunit α (PP1cα) gene Tc-stp-1 and PP1 regulatory subunit 7 (PP1r7) gene TcM-1309. Indirect fluorescence immunocytochemistry was carried out to determine the subcellular distribution of PP1cα. Double-stranded RNA interference (RNAi) assays were employed to illustrate the function and mechanism of PP1cα in male adult reproduction. Real-time quantitative PCR (qPCR) showed transcriptional consistency of Tc-stp-1 and TcM-1309 in sperm-producing germline tissues and localization research showed cytoplasmic distribution of PP1cα in sf9 cells, which indicated relevant involvements of PP1cα and PP1r7 in spermatogenesis. Moreover, spatiotemporal transcriptional differences of Tc-stp-1 were determined by gene knockdown analysis, which revealed abnormal morphologies and blocked meiotic divisions of spermatocytes by phenotypic aberration scanning, thereby highlighting the crucial involvement of PP1cα in spermatogenesis. These results revealed a PP1cα-PP1r7 mechanism by which PP1 regulates kinetochore-microtubule interactions in spermatogenesis and provided important clues to identify novel drug or vaccine targets for toxocariasis control. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Emotional exhaustion is associated with work related stressors: a cross-sectional multicenter study in Malaysian public hospitals.

    Science.gov (United States)

    Khoo, Erwin J; Aldubai, Sami; Ganasegeran, Kurubaran; Lee, Bernice Xe; Zakaria, Nurul A; Tan, Kah K

    2017-06-01

    Emotional exhaustion is an important component of burnout. Burnout is common among doctors. It affects the physical and mental health of doctors, their performance and the quality of care they provide. This study aimed to investigate the level and factors associated with emotional exhaustion among doctors in pediatric practice in Malaysia. A self-administered questionnaire was used in this multicenter cross-sectional study. It included questions on the socio-demographics, work characteristics, Emotional Exhaustion, Perceived Stress Scale and sources of job stress. Descriptive, univariate and multivariate analysis were conducted using the SPSS software. A total of 197 doctors working in the Pediatric department in eight hospitals returned complete questionnaire. High and moderate emotional exhaustion was reported by 25.4% and 24.4% doctors, respectively. In bivariate analysis, 29 out of the 38 items of sources of stress showed significant association with emotional exhaustion (p appreciation from supervisors, lack of incentives and promotions, time pressures and deadlines to meet, and setting unrealistic goals of having them imposed on oneself (p workplace but not with socio-demographic factors.

  7. Elevated exhaust temperature, zoned, electrically-heated particulate matter filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI; Bhatia, Garima [Bangalore, IN

    2012-04-17

    A system includes an electrical heater and a particulate matter (PM) filter that is arranged one of adjacent to and in contact with the electrical heater. A control module selectively increases an exhaust gas temperature of an engine to a first temperature and that initiates regeneration of the PM filter using the electrical heater while the exhaust gas temperature is above the first temperature. The first temperature is greater than a maximum exhaust gas temperature at the PM filter during non-regeneration operation and is less than an oxidation temperature of the PM.

  8. High-speed schlieren imaging of rocket exhaust plumes

    Science.gov (United States)

    Coultas-McKenney, Caralyn; Winter, Kyle; Hargather, Michael

    2016-11-01

    Experiments are conducted to examine the exhaust of a variety of rocket engines. The rocket engines are mounted in a schlieren system to allow high-speed imaging of the engine exhaust during startup, steady state, and shutdown. A variety of rocket engines are explored including a research-scale liquid rocket engine, consumer/amateur solid rocket motors, and water bottle rockets. Comparisons of the exhaust characteristics, thrust and cost for this range of rockets is presented. The variety of nozzle designs, target functions, and propellant type provides unique variations in the schlieren imaging.

  9. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    CERN Document Server

    Foust, D J

    2000-01-01

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

  10. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    International Nuclear Information System (INIS)

    FOUST, D.J.

    2000-01-01

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering

  11. Effect Effects of Auricularia auricula Polysaccharides on Exhaustive ...

    African Journals Online (AJOL)

    Exhaustive Swimming Exercise-Induced Oxidative Stress in Mice. Haitao Hao .... of the College of Life Sciences, China Jiliang. University ..... The delicate physiological balance between oxidative ... This work was supported by funds from.

  12. Surface chloride salt formation on Space Shuttle exhaust alumina

    Science.gov (United States)

    Cofer, W. R., III; Pellett, G. L.; Sebacher, D. I.; Wakelyn, N. T.

    1984-01-01

    Aluminum oxide samples from the exhaust of Space Shuttle launches STS-1, STS-4, STS-5, and STS-6 were collected from surfaces on or around the launch pad complex and chemically analyzed. The results indicate that the particulate solid-propellant rocket motor (SRM) alumina was heavily chlorided. Concentrations of water-soluble aluminum (III) ion were large, suggesting that the surface of the SRM alumina particles was rendered soluble by prior reactions with HCl and H2O in the SRM exhaust cloud. These results suggest that Space Shuttle exhaust alumina particles are good sites for nucleation and condensation of atmospheric water. Laboratory experiments conducted at 220 C suggest that partial surface chloriding of alumina may occur in hot Space Shuttle exhaust plumes.

  13. Muscle interstitial potassium kinetics during intense exhaustive exercise

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai; Mohr, Magni; Pedersen, Lasse Dannemann

    2003-01-01

    Interstitial K+ ([K+]i) was measured in human skeletal muscle by microdialysis during exhaustive leg exercise, with (AL) and without (L) previous intense arm exercise. In addition, the reproducibility of the [K+]i determinations was examined. Possible microdialysis-induced rupture of the sarcolemma...... was assessed by measurement of carnosine in the dialysate, because carnosine is only expected to be found intracellularly. Changes in [K+]i could be reproduced, when exhaustive leg exercise was performed on two different days, with a between-day difference of approximately 0.5 mM at rest and 1.5 m......M at exhaustion. The time to exhaustion was shorter in AL than in L (2.7 +/- 0.3 vs. 4.0 +/- 0.3 min; P exercise period in AL compared with L (9.2 +/- 0.7 vs. 6.4 +/- 0.9 mM; P

  14. Effect of diesel generator exhaust pollutants on growth of Vinca ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: The effects of exhaust pollutants of generator on root and shoot length, root and shoot weight, number of .... single cylinders with cooling system of air dry. The frequency is 50 .... and reproduction along CO2 gradients. Nonlinear.

  15. Exhaust gas purifying system for an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Minami, H; Saito, Z

    1976-10-07

    The exhaust gas purification system is a so-called three-way catalytic converter. It consists of an oxidation converter, a reduction converter, or a thermal converter. An exhaust sensor made up of an oxygen sensor, a carbon sensor, a carbon monoxide sensor, hydrocarbon sensor, or a nitrogen peroxide sensor, tests the composition of the exhaust and controls the air-fuel feed system in dependence of the exhaust mixture in such a manner that in the intake system an air-fuel mixture is taken in which the stoichiometric air-fuel relation is produced. Moreover, a thermostatically controlled air intake device is built into the fuel injection system which supplies the air of the fuel injection system with a relatively consistent temperature.

  16. EFEK ZAT AKTIF EKSTRAK DAUN JAMBU BIJI MERAH (PSIDIUM GUAJAVA.L TERHADAP SPERMATOGENESIS PADA TIKUS PUTIH JANTAN (RATTUS NORVEGICUS

    Directory of Open Access Journals (Sweden)

    Ervi Husni

    2016-11-01

    Full Text Available Pendahuluan: Jumlah penduduk Indonesia sensus tahun 2010 sebanyak 237,6 juta jiwa dengan laju pertumbuhan penduduk 1,49 % per tahun. Target RPJPMN 2010-2014 sebesar1,14 %, laju pertumbuhan penduduk saat ini  0,53 % masih lebih tinggi. Pengendalian penduduk diperlukan antara lain dengan pemakaian kontrasepsi pada wanita maupun pria. Keterlibatan pria dalam KB masih rendah hanya 6,26 %. Tujuan penelitian untuk membuktikan zat aktif daun jambu biji merah dapat menurunkan kadar FSH dan spermatogenesis pada tikus putih jantan (Rattus norvegikus. Metode: Penelitian ini merupakan penelitian eksperimen dengan rancangan Post test only control group design. Besar sampel menggunakan rumus Federer dengan jumlah sampel 30 ekor tikus putih, terbagi tiga kelompok yaitu Kelompok 1 (K1 kelompok kontrol diberikan larutan CMC 0,5 % 1 ml/ hari, Kelompok Perlakuan 1 (P1 diberikan ekstrak daun jambu biji merah dosis 40 mg/ml/hari dan kelompok Perlakuan 2 (P2 diberikan ekstrak daun jambu biji merah dosis 80 mg/ml/hari dan diberikan selama 30 hari. Variabel penelitian  jumlah sel spermatogenik ( Spermatogonium, Spermatosit primer dan Spermatid. Data dianalisis menggunakan uji  ANOVA. Hasil: Hasil analisis data dengan uji ANOVA jumlah sel spermatogonium nilai p 0,801 (p < 0,05: tidak ada perbedaan signifikan diantara ketiga kelompok, uji LSD tidak dilakukan. Hasil uji ANOVA untuk jumlah sel spermatosit primer didapatkan nilai p 0,102 ( p < 0,05 , berarti  tidak ada perbedaan signifikan diantara ketiga kelompok, uji LSD tidak dilakukan. Hasil uji ANOVA untuk jumlah sel spermatid nilai p 0,001  (p < 0,05 berarti terdapat perbedaan signifikan diantara ketiga kelompok. Hasil uji LSD kontrol dengan P1 (p 0,036 : berbeda, Kontrol dengan P2 (p <0,000: berbeda, P1 dengan P2 (p <0,033 : berbeda. Diskusi: Kesimpulan penelitian ini adalah pemberian ekstrak daun jambu biji merah tidak menurunkan jumlah sel spermatogonium dan sel spermatosit primer tetapi menurunkan jumlah

  17. Exhaustible natural resources, normal prices and intertemporal equilibrium

    OpenAIRE

    Parrinello, Sergio

    2003-01-01

    This paper proposes an extension of the classical theory of normal prices to an n-commodity economy with exhaustible natural resources. The central idea is developed by two analytical steps. Firstly, it is assumed that a given flow of an exhaustible resource in short supply is combined with the coexistence of two methods of production using that resource. Sraffa’s equations are reinterpreted by adopting the concept of effectual supply of natural resources and avoiding the assumption of perfec...

  18. A system recovering heat from exhaust gases. Abgasenergie-Rueckgewinnungseinrichtung

    Energy Technology Data Exchange (ETDEWEB)

    John, E; Hultsch, H; Brendorp, W

    1990-08-16

    The proposed exhaust gas heat recovery system is provided with a hydraulic clutch (8) which is located between a gas tubine (2) to be driven by the exhaust gases of an internal combustion engine (20) and a drive unit (18) of the internal combustion engine (20). A mechanical blocking device (6) prevents the turbine from running at explosion speed when the hydraulic clutch (8) is emptied or when the oil pressure of the hydraulic clutch drops below a certain minimum.

  19. Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-15-1-0644 TITLE: Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells PRINCIPAL INVESTIGATOR: Chun-Ju...Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0644 5c. PROGRAM ELEMENT...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Cancer stem cells (CSCs), a cell population with acquired perpetuating self-renewal properties which

  20. LOFT diesel generator ''A'' exhaust stack seismic analysis

    International Nuclear Information System (INIS)

    Blandford, R.K.

    1978-01-01

    A stress analysis of the LOFT Diesel Generator ''A'' Exhaust Stack was performed to determine its reaction to Safe-Shutdown Earthquake loads. The exhaust stack silencer and supporting foundation was found to be inadequate for the postulated seismic accelerations. Lateral support is required to prevent overturning of the silencer pedestal and reinforcement of the 4'' x 0.5'' silencer base straps is necessary. Basic requirements for this additional support are discussed

  1. The cognitive/affective distinction of job insecurity: Validation and ...

    African Journals Online (AJOL)

    Kirstam

    emotional exhaustion were also gathered from employees in a variety of South African ... the cognitive and affective dimensions of job insecurity could be distinguished ...... from the perception of an external reality, whereas the affective response represents an internal .... 'Differentiating cognitive and affective job insecurity: ...

  2. Diesel engine exhaust particulate filter with intake throttling incineration control

    Energy Technology Data Exchange (ETDEWEB)

    Ludecke, O.; Rosebrock, T.

    1980-07-08

    A description is given of a diesel engine exhaust filter and particulate incineration system in combination with a diesel engine having a normally unthrottled air induction system for admitting combustion air to the engine and an exhaust system for carrying off spent combustion products exhausted from the engine, said filter and incineration system comprising: a combustion resistant filter disposed in the exhaust system and operative to collect and retain portions of the largely carbonaceous particulate matter contained in the engine exhaust products, said fiber being capable of withstanding without substantial damage internal temperatures sufficient to burn the collected particulate matter, a throttle in the indication system and operable to restrict air flow into the engine to reduce the admittance of excess combustion air and thereby increase engine exhaust gas temperature, and means to actuate said throttle periodically during engine operation to an air flow restricting burn mode capable of raising the particulates in said filter to their combustion temperature under certain engine operating conditions and to maintain said throttle mode for an interval adequate to burn retained particulates in the filter.

  3. Simulation of exhaust gas heat recovery from a spray dryer

    International Nuclear Information System (INIS)

    Golman, Boris; Julklang, Wittaya

    2014-01-01

    This study explored various alternatives in improving the energy utilization of spray drying process through the exhaust gas heat recovery. Extensible and user-friendly simulation code was written in Visual Basic for Applications within Microsoft Excel for this purpose. The effects of process parameters were analyzed on the energy efficiency and energy saving in the industrial-scale spray drying system with exhaust gas heat recovery in an air-to-air heat exchanger and in the system with partial recirculation of exhaust air. The spray dryer is equipped with an indirect heater for heating the drying air. The maximum gains of 16% in energy efficiency and 50% in energy saving were obtained for spray drying system equipped with heat exchanger for exhaust air heat recovery. In addition, 34% in energy efficiency and 61% in energy saving for system with recirculation of exhaust air in the present range of process parameters. The high energy efficiency was obtained during drying of large amount of dilute slurry. The energy saving was increased using the large amount of hot drying air. - Highlights: • We model industrial-scale spray drying process with the exhaust gas heat recovery. • We develop an Excel VBA computer program to simulate spray dryer with heat recovery. • We examine effects of process parameters on energy efficiency and energy saving. • High energy efficiency is obtained during drying of large amount of dilute slurry. • Energy saving is increased using the large amount of hot drying air

  4. Effect of Pellet Boiler Exhaust on Secondary Organic Aerosol Formation from α-Pinene.

    Science.gov (United States)

    Kari, Eetu; Hao, Liqing; Yli-Pirilä, Pasi; Leskinen, Ari; Kortelainen, Miika; Grigonyte, Julija; Worsnop, Douglas R; Jokiniemi, Jorma; Sippula, Olli; Faiola, Celia L; Virtanen, Annele

    2017-02-07

    Interactions between anthropogenic and biogenic emissions, and implications for aerosol production, have raised particular scientific interest. Despite active research in this area, real anthropogenic emission sources have not been exploited for anthropogenic-biogenic interaction studies until now. This work examines these interactions using α-pinene and pellet boiler emissions as a model test system. The impact of pellet boiler emissions on secondary organic aerosol (SOA) formation from α-pinene photo-oxidation was studied under atmospherically relevant conditions in an environmental chamber. The aim of this study was to identify which of the major pellet exhaust components (including high nitrogen oxide (NO x ), primary particles, or a combination of the two) affected SOA formation from α-pinene. Results demonstrated that high NO x concentrations emitted by the pellet boiler reduced SOA yields from α-pinene, whereas the chemical properties of the primary particles emitted by the pellet boiler had no effect on observed SOA yields. The maximum SOA yield of α-pinene in the presence of pellet boiler exhaust (under high-NO x conditions) was 18.7% and in the absence of pellet boiler exhaust (under low-NO x conditions) was 34.1%. The reduced SOA yield under high-NO x conditions was caused by changes in gas-phase chemistry that led to the formation of organonitrate compounds.

  5. Hospital nurse staffing and patient mortality, emotional exhaustion, and job dissatisfaction.

    Science.gov (United States)

    Halm, Margo; Peterson, Michelle; Kandels, Mary; Sabo, Julie; Blalock, Miriam; Braden, Rebecca; Gryczman, Anna; Krisko-Hagel, Kathryn; Larson, Dave; Lemay, Diane; Sisler, Bette; Strom, Linda; Topham, Debra

    2005-01-01

    To conduct an investigation similar to a landmark study that investigated the association between nurse-to-patient ratio and patient mortality, failure-to-rescue, emotional exhaustion and job satisfaction of nurses. Cross-sectional analysis of 2709 general, orthopedic, and vascular surgery patients, and 140 staff nurses (42% response rate) caring for these patients in a large Midwestern institution. The main outcome measures were mortality, failure-to-rescue, emotional exhaustion, and job dissatisfaction. Staffing was not a significant predictor of mortality or failure-to-rescue, nor did clinical specialty predict emotional exhaustion or job dissatisfaction. Although these findings reinforce adequate staffing ratios at this institution, programs that support nurses in their daily practice and positively impact job satisfaction need to be explored. The Nursing Research Council not only has heightened awareness of how staffing ratios affect patient and nurse outcomes, but also a broader understanding of how the research process can be used to effectively shape nurse's practice and work environments.

  6. Effects of a process-based cognitive training intervention for patients with stress-related exhaustion.

    Science.gov (United States)

    Gavelin, Hanna Malmberg; Boraxbekk, Carl-Johan; Stenlund, Therese; Järvholm, Lisbeth Slunga; Neely, Anna Stigsdotter

    2015-01-01

    Stress-related exhaustion has been linked to a pattern of selective cognitive impairments, mainly affecting executive functioning, attention and episodic memory. Little is known about potential treatments of these cognitive deficits. The purpose of this study was to evaluate the effects of a process-based cognitive training intervention, designed to target the specific cognitive impairments associated with stress-related exhaustion. To this end, patients diagnosed with exhaustion disorder (ED) were randomized to either a multimodal stress rehabilitation program with the addition of a process-based cognitive training intervention (training group, n = 27) or a treatment-as-usual control condition, consisting of multimodal stress rehabilitation with no additional training (control group, n = 32). Treatment effects were evaluated through an extensive cognitive test battery, assessing both near and far transfer effects, as well as self-report forms regarding subjective cognitive complaints and burnout levels. Results showed pronounced training-related improvements on the criterion updating task (p effects to updating (p = 0.01) and episodic memory (p = 0.04). Also, the trained group reported less subjective memory complaints (p = 0.02) and levels of burnout decreased for both groups, but more so for the trained group (p = 0.04), following the intervention. These findings suggest that process-based cognitive training may be a viable method to address the cognitive impairments associated with ED.

  7. Effect of exhaust gas recirculation on some combustion characteristics of dual fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Selim, Mohamed Y.E. [United Arab Emirates Univ., Dept. of Mechanical Engineering, Al-Ain (United Arab Emirates)

    2003-03-01

    Combustion pressure rise rate and thermal efficiency data are measured and presented for a dual fuel engine running on a dual fuel of Diesel and compressed natural gas and utilizing exhaust gas recirculation (EGR). The maximum pressure rise rate during combustion is presented as a measure of combustion noise. The experimental investigation on the dual fuel engine revealed the noise generated from combustion and the thermal efficiency at different EGR ratios. A Ricardo E6 Diesel version engine is converted to run on a dual fuel of Diesel and compressed natural gas and having an exhaust gas recycling system is used throughout the work. The engine is fully computerized, and the cylinder pressure data and crank angle data are stored in a PC for offline analysis. The effects of EGR ratio, engine speeds, loads, temperature of recycled exhaust gases, intake charge pressure and engine compression ratio on combustion noise and thermal efficiency are examined for the dual fuel engine. The combustion noise and thermal efficiency of the dual fuel engine are found to be affected when EGR is used in the dual fuel engine. (Author)

  8. Numerical study on the influence of aluminum on infrared radiation signature of exhaust plume

    Science.gov (United States)

    Zhang, Wei; Ye, Qing-qing; Li, Shi-peng; Wang, Ning-fei

    2013-09-01

    The infrared radiation signature of exhaust plume from solid propellant rockets has been widely mentioned for its important realistic meaning. The content of aluminum powder in the propellants is a key factor that affects the infrared radiation signature of the plume. The related studies are mostly on the conical nozzles. In this paper, the influence of aluminum on the flow field of plume, temperature distribution, and the infrared radiation characteristics were numerically studied with an object of 3D quadrate nozzle. Firstly, the gas phase flow field and gas-solid multi phase flow filed of the exhaust plume were calculated using CFD method. The result indicates that the Al203 particles have significant effect on the flow field of plume. Secondly, the radiation transfer equation was solved by using a discrete coordinate method. The spectral radiation intensity from 1000-2400 cm-1 was obtained. To study the infrared radiation characteristics of exhaust plume, an exceptional quadrate nozzle was employed and much attention was paid to the influences of Al203 particles in solid propellants. The results could dedicate the design of the divert control motor in such hypervelocity interceptors or missiles, or be of certain meaning to the improvement of ingredients of solid propellants.

  9. Some aspects on the reproductive cycle of European conger eel, Conger conger (Linnaeus, 1758 (Osteichthyes, Anguilliformes, Congridae captured from Western Algerian coasts: a histological description of spermatogenesis

    Directory of Open Access Journals (Sweden)

    Abi-ayad Sidi-Mohammed El-Amine

    2011-09-01

    Full Text Available The aim of this work was to study the annual reproductive cycle of European conger eel (Conger conger,Linnaeus, 1758 through analysis and description of spermatogenesis. A sample of 168 males was capturedbetween September 2008 and August 2009 from the Western coast of Algeria, from Béni Saf. Fish length andweight varied between 26.20-112 cm and 0.45-3.44 kg, respectively.Condition factors (K, gonadosomatic index (G.S.I. and hepatosomatic index (H.S.I. were calculatedmonthly. Factor K reached the minimum in August/September (0.10% corresponding to reproductive periodand a maximum in January (0.18%. Although G.S.I. values revealed to be statistically not significant, therewere two peaks for G.S.I., the first in March, denoting the beginning of spermatogenesis, and the second inAugust/September, indicating the reproduction period. H.S.I. reached a peak in December (1.90%, then thevalue decreased to a minimum in April.Histological analysis of testis allowed us to distinguish 5 stages summarized as follows: Stage 1:Spermatogonia A; Stage 2: Spermatogonia B; Stage 3: Spermatocytes and spermatids; Stage 4: Spermatocytes,spermatids and spermatozoa (cytodifferentiation of spermatids into spermatozoa; Stage 5: Spermatozoa(spermiogenesis or cytodifferentiation of spermatids into spermatozoa.

  10. Changes in the biochemical composition of testes during spermatogenesis in Asterias vulgaris, with emphasis on the role of polyamines in regulating proliferation

    International Nuclear Information System (INIS)

    Smith, F.F.

    1985-01-01

    Testes of Asterias vulgaris are potentially useful for investigating mechanisms regulating spermatogenic events because of their structural simplicity and annual spermatogenic cycle. Examination of major biochemical classes during the spermatogenic cycle provides a definition of the changing chemical microenvironment influencing germinal cells and also suggests temporal relationships among successive spermatogenic events. Testes from seastars collected throughout the year were homogenized and lyophilized and aliquots assayed for DNA, RNA, total protein, free amino acids, total lipids, glycogen, and other carbohydrates; spermatogenic stage was determined by examination of paraffin sections. Activity of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine synthesis, increases during the proliferative phase of spermatogenesis. Testicular ODC activity correlates well with DNA synthetic rate. To test the possible role of polyamines in regulating initiation of spermatogonial mitoses, intact testes near the beginning of the proliferative phase were incubated in vitro with exogenous polyamines. They subsequently showed a significant increase in incorporation of 3 H-thymidine into DNA. These results suggest a direct role for polyamines in the regulation of spermatogenic proliferation in a. vulgaris. Evidence for a regulatory role of polyamines in the initiation of proliferation, together with existing information on the environmental, hormonal, and cytological interactions, facilitates development of a preliminary model for regulation and entrainment of spermatogenesis

  11. 3-Monochloropropane-1,2-diol (alpha-chlorohydrin) disrupts spermatogenesis and causes spermatotoxicity in males of the Egyptian fruit-bat (Rousettus aegyptiacus).

    Science.gov (United States)

    Mahmoud, Y I; Taha, A; Soliman, S

    2018-03-29

    We evaluated the sterilizing effect of 3-monochloropropane-1, 2-diol (3-MCPD) in male Egyptian fruit bats (Rousettus aegyptiacus). We used three groups. One was treated with 70 mg/kg 3-MCPD for 4 days. The second group was treated with 3-MCPD as a bait formulation (known concentration of 3-MCPD mixed with a known amount of food). The third group was untreated controls. We compared the weights of the reproductive organs, histology of the testes, occurrence of spermatogenesis, and the count, motility and abnormalities of epididymal sperm of treated males with those of the untreated control group. 3-MCPD caused significantly decreased weights of reproductive organs, several testicular histological alterations and spermatogenic arrest accompanied by significant decreases in sperm count and motility, and significantly increased number of abnormal sperm. 3-MCPD bait was readily accepted by the animals. 3-MCPD, even in low doses and after limited exposure, disrupted spermatogenesis in males of the Egyptian fruit bat. Our findings have potential value for public health and agricultural authorities, and for vertebrate pest managers. 3-MCPD may have application for control of this pest.

  12. Effect of Hydro Alcoholic Ginger Extracts on the Body Weight, Testis Weight and Spermatogenesis in Male Rats Undergoing Chemotherapy with Cyclophosphamide

    Directory of Open Access Journals (Sweden)

    E Sharifi

    2010-03-01

    Full Text Available Introduction: Cyclophosphamide is used as an anti cancer medicine in chemotherapy. This is an alkalizing medicine and causes the binding of DNA strands, breaking of DNA and control of protein synthesis and RNA. The side effects of this medicine include lack of appetite, nausea, reduction in activity of sexual lymph nodes, causing amenorrhea, azoospermia and oligospermia. Ginger includes many compounds, some of which are shogaols, gingerols, pyrogallols and sesquiterpenes. Ginger has anti nauseating, anti cancer, anti oxidant effects and eliminates free radicals. This medicine is used along with cyclophosphamide to reduce its destructive side effects in the body. Methods: For 21 days, the rats were fed with ginger and cyclophosphamide. After 21 days, the animals were weighed and rendered unconscious. Their testes were removed and tissue samples were provided from their testes. Results: The results showed that cyclophosphamide alone reduces body weight, testes weight and spermatogenesis as compared to the control group. In other experimental groups that were fed with ginger and cyclophosphamide, increased dosage of ginger increased the body weight, the testes weight and spermatogenesis in comparison to the other experimental groups. Conclusion: It seems that compounds present in ginger are anti tumoral and control the production of active metabolites. Therefore, if administered together with Cyclophosphamide, it can be useful and effective in patients undergoing chemotherapy.

  13. Evaluation of Fertility Disrupting Potentials of Abrus precatorius Seed Extracts in Male Rats for Arresting Spermatogenesis and Suppressed Fertility In Vivo

    Directory of Open Access Journals (Sweden)

    Saranika Talukder

    2014-01-01

    Full Text Available This study was aimed to evaluate the contraceptive potentials of different chemical extracts of Abrus precatorius seeds in male albino rats. The active ingredients of crushed seeds were extracted with 60% aqueous acetone and then partitioned consecutively with n-hexane, ethyl acetate, methanol and water. Water suspended chemical fractions at different doses were administered orally to the male rats for 40 days. Effects of different treatments on various male reproductive endpoints and contraceptive efficacy were evaluated. Oral administration of both organic (methanol soluble at 50 and 75 mg/kg BW and aqueous soluble of A. precatorius seed extracts caused infertility in study subjects at varying degrees. At necropsy, average weights of testes, epididymis, ventral prostate gland and seminal vesicles were decreased significantly. Histology of testes revealed marked atrophy of the seminiferous tubules characterized by disruption of the germinal epithelium and atrophy of the Leydig cells. Epididymis also showed histological alterations. Hormonal assay revealed a significant decrease in serum level of testosterone, follicle stimulating hormone (FSH and luteinizing hormone (LH that possibly resulted in suppressed spermatogenesis of male rats. These effects lead to the reduction of pregnancy rate of untreated fertile female rats while mated with the methanol extract (50 and 75 mg/kg BW and aqueous extract-treated male rats. The results show that A. precatorius seed extract causes suppression of spermatogenesis and fertility, thereby suggesting the potential of this plant in the regulation of male fertility.

  14. Perturbation in protein expression of the sterile salmonid hybrids between female brook trout Salvelinus fontinalis and male masu salmon Oncorhynchus masou during early spermatogenesis.

    Science.gov (United States)

    Zheng, Liang; Senda, Yoshie; Abe, Syuiti

    2013-05-01

    Most males and females of intergeneric hybrid (BM) between female brook trout (Bt) Salvelinus fontinalis and male masu salmon (Ms) Oncorhynchus masou had undeveloped gonads, with abnormal germ cell development shown by histological examination. To understand the cause of this hybrid sterility, expression profiles of testicular proteins in the BM and parental species were examined with 2-DE coupled with MALDI-TOF/TOF MS. Compared with the parental species, more than 60% of differentially expressed protein spots were down-regulated in BM. A total of 16 up-regulated and 48 down-regulated proteins were identified in BM. Up-regulated were transferrin and other somatic cell-predominant proteins, whereas down-regulated were some germ cell-specific proteins such as DEAD box RNA helicase Vasa. Other pronouncedly down-regulated proteins included tubulins and heat shock proteins that are supposed to have roles in spermatogenesis. The present findings suggest direct association of the observed perturbation in protein expression with the failure of spermatogenesis and the sterility in the examined salmonid hybrids. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Anatomy and histology of the male reproductive tract and spermatogenesis fine structure in the lesser anteater (Tamandua tetradactyla, Myrmecophagidae, Xenarthra): morphological evidences of reproductive functions.

    Science.gov (United States)

    Rossi, L F; Luaces, J P; Aldana Marcos, H J; Cetica, P D; Perez Jimeno, G; Merani, M S

    2013-08-01

    The anatomy and histology of the male genital tract of the lesser anteater were studied. Fine details of spermatozoa regarding their genesis and morphology were also studied in six adult specimens. The testes lie in the pelvic cavity. The deferent duct emerges from the epididymis and opens into the ejaculatory duct, which drains into the membranous urethra. Accessory glands (prostate, seminal vesicle and bulbourethral gland) are histologically similar to those described in other mammals. The short penis presents an urethral orifice, while the corpus spongiosum becomes thinner at the end indicating the absence of a histologically defined glans. The seminiferous epithelium shows: (1) Sertoli cells with deep nuclear indentations, (2) spermatogonia with crusty-like chromatin, (3) spermatocytes at different stages of maturation and (4) three morphologically distinct stages of spermatid differentiation according to nuclear shape, acrosome development and chromatin condensation. Sperm heads appear oval. The length of the spermatozoa averages 67.33 ± 1.60 μm. Two specimens with inactive spermatogenesis were azoospermic. Their testes and epididymis presented sizes smaller than those with active spermatogenesis. These studies together with others in anteaters may contribute to successful breeding in conservation programmes. © 2012 Blackwell Verlag GmbH.

  16. 40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.

    Science.gov (United States)

    2010-07-01

    ... exhaust duct excludes the length of pipe representative of the vehicle exhaust pipe) shall be minimized... exhaust manifold, immediately after exhaust aftertreatment systems, or after a length of pipe representative of the vehicle exhaust pipe; or (iv) Partial dilution of the exhaust gas prior to entering the...

  17. Chemosterilization: Spermatogenesis, Steroidogenesis ...

    African Journals Online (AJOL)

    the oxidative stress inducing (i.e., reactive oxygen species generating) ... of fertility is in direct relation to the degree of motility of sperm.[10] ... female. Furthermore, chemical castration had a greater effect on the decrease of aggression than surgical castration.[16]. In 2001, a study was performed to determine the effects.

  18. Swimming training induces liver mitochondrial adaptations to oxidative stress in rats submitted to repeated exhaustive swimming bouts.

    Directory of Open Access Journals (Sweden)

    Frederico D Lima

    Full Text Available BACKGROUND AND AIMS: Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts. METHODS: Wistar rats were divided into training (n = 14 and control (n = 14 groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7 and control (n = 7 rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed. RESULTS: Trained group showed increased reduced glutathione (GSH content and reduced/oxidized (GSH/GSSG ratio, higher superoxide dismutase (MnSOD activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group. CONCLUSIONS: Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance.

  19. A combined approach to heat stress effect on male fertility in Nasonia vitripennis: from the physiological consequences on spermatogenesis to the reproductive adjustment of females mated with stressed males.

    Directory of Open Access Journals (Sweden)

    Marlène Chirault

    Full Text Available In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.

  20. A combined approach to heat stress effect on male fertility in Nasonia vitripennis: from the physiological consequences on spermatogenesis to the reproductive adjustment of females mated with stressed males.

    Science.gov (United States)

    Chirault, Marlène; Lucas, Christophe; Goubault, Marlène; Chevrier, Claude; Bressac, Christophe; Lécureuil, Charlotte

    2015-01-01

    In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.

  1. Investigation of the effect of different carbon film thickness on the exhaust valve

    Science.gov (United States)

    Karamangil, M. I.; Avci, A.; Bilal, H.

    2008-03-01

    Valves working under different loads and temperatures are the mostly forced engine elements. In an internal combustion engine, pressures and temperatures affecting on the valves vary with fuel type and the combustion characteristics of the fuel. Consequently, valves are exposed to different dynamic and thermal stress. In this study, stress distributions and temperature profiles on exhaust valve are obtained depending on different carbon film thickness. It is concluded that heat losses and valve temperatures decrease and valve surfaces are exposed to less thermal shocks with increasing carbon film thickness.

  2. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2009-11-01

    The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats

  3. REVIEW ARTICLE: MODELLING AND ANALYSIS OF A GASOLINE ENGINE EXHAUST GAS SYSTEMS

    OpenAIRE

    Barhm Mohamad

    2018-01-01

    The engine exhaust gas behaviour is strongly influencing the engine performance. This paper presents the modelling and analysis of four stroke - gasoline engine exhaust gas systems. An automotive example is considered whereby the pulsating exhausts gas flow through an exhaust pipe and silencer are considered over a wide range of speeds. Analytical procedures are outlined enabling the general analysis and modelling of vehicle engine exhaust gas systems also in this paper present...

  4. Effect of the nandrolone decanoate on the efficiency of spermatogenesis of sedentary rats and rats subjected to physical training - DOI: 10.4025/actascihealthsci.v32i1.5741

    Directory of Open Access Journals (Sweden)

    Fernanda Ferrari

    2009-12-01

    Full Text Available Spermatogenesis is a complex, highly organized and coordinated process that results in the production of male gametes. This process is influenced by a number of drugs that enhance physical performance, which have been used mainly by young people, athletes or not, seeking to gain athletic performance or only a prominent social position. The objective of this study was to evaluate the effects of the anabolic steroid nandrolone decanoate on the efficiency of spermatogenesis in sedentary rats and rats subjected to physical training. Twenty-four male rats were divided into four experimental groups: sedentary control, sedentary treated, trained control and trained treated. Treated animals received intramuscular injection of nandrolone decanoate (0.5 mg kg-1 body weight during the last four weeks of physical training. The training program consisted of running on a programmable ergometer treadmill, tailored to train eight rats simultaneously, for nine weeks. We evaluated the morphological and morphoquantitative profiles of the male reproductive system. The results showed that the treatment causes a reduction in the efficiency of spermatogenesis; however, when associated with physical training, this compensates for the anabolic action, keeping the process of spermatogenesis within normality.

  5. Trace elements in particles of motor vehicle exhaust in Shanghai

    International Nuclear Information System (INIS)

    Jiang Da; Qiu Zhijun; Lu Rongrong; Qiu Huiyuan; Zhu Jieqing; Li Xiaolin

    2002-01-01

    A nuclear microprobe with high spatial resolution and high analytical sensitivity was applied to analyze trace elements, especially lead, in vehicle exhaust of Shanghai city. The result shows that the chemical composition and its corresponding x-ray relative intensity are different among different vehicle exhausts. There are many kinds of metal elements in particles of vehicle exhaust, most are harmful to people, such as Ti, Cr, Mn, Pb, etc. The authors found that the lead concentration was 6820 μg/g and the bromine concentration was 5300 μg/g in the exhaust from Santana using leaded gasoline (SULG), which is higher than any other kinds of vehicle exhausts. The authors have also detected the minimum lead in the particles of unleaded gasoline and its content varies from one to another. Its mean concentration was 450 μg/g and the highest reached 6210 μg/g. The unleaded gasoline's Pb existed in the whole particle while the leaded gasoline's enriched in the surface of the particle and was more harmful to the human beings

  6. Variation of particle exhaust with changes in divertor magnetic balance

    International Nuclear Information System (INIS)

    Petrie, T.W.; Allen, S.L.; Brooks, N.H.

    2006-01-01

    Recent experiments on DIII-D point to the importance of two factors in determining how effectively the deuterium particle inventory in a tokamak plasma can be controlled through pumping at the divertor target(s): (1) the divertor magnetic balance, i.e. the degree to which the divertor topology is single-null or double-null (DN) and (2) the direction of the of B x ∇B ion drift with respect to the X-point(s). Changes in divertor magnetic balance near the DN shape have a much stronger effect on the particle exhaust rate at the inner divertor target(s) than on the particle exhaust rate at the outer divertor target(s). The particle exhaust rate for the DN shape is strongest at the outer strike point opposite the B x ∇B ion particle drift direction. Our data suggests that the presence of B x ∇B and E x B ion particle drifts in the scrape-off layer and divertor(s) play an important role in the particle exhaust rates of DN and near-DN plasmas. Particle exhaust rates are shown to depend strongly on the edge (pedestal) density. These results have implications for particle control in ITER and other future tokamaks

  7. Design and experimental study on desulphurization process of ship exhaust

    Science.gov (United States)

    Han, Mingyang; Hao, Shan; Zhou, Junbo; Gao, Liping

    2018-02-01

    This desulfurization process involves removing sulfur oxides with seawater or alkaline aqueous solutions and then treating the effluent by aeration and pH adjustment before discharging it into the ocean. In the desulfurization system, the spray tower is the key equipment and the venturi tubes are the pretreatment device. The two stages of plates are designed to fully absorb sulfur oxides in exhaust gases. The spiral nozzles atomize and evenly spray the desulfurizers into the tower. This study experimentally investigated the effectiveness of this desulfurization process and the factors influencing it under laboratory conditions, with a diesel engine exhaust used to represent ship exhaust. The experimental results show that this process can effectively absorb the SO2 in the exhaust. When the exhaust flow rate was 25 m3/h and the desulfurizer flow rate was 4 L/min, the sulfur removal efficiency (SRE) reached 99.7%. The flow rate, alkalinity, and temperature of seawater were found to have significant effects on the SRE. Adjusting seawater flow rate (SWR) and alkalinity within certain ranges can substantially improve the SRE.

  8. Simulation of Wake Vortex Radiometric Detection via Jet Exhaust Proxy

    Science.gov (United States)

    Daniels, Taumi S.

    2015-01-01

    This paper describes an analysis of the potential of an airborne hyperspectral imaging IR instrument to infer wake vortices via turbine jet exhaust as a proxy. The goal was to determine the requirements for an imaging spectrometer or radiometer to effectively detect the exhaust plume, and by inference, the location of the wake vortices. The effort examines the gas spectroscopy of the various major constituents of turbine jet exhaust and their contributions to the modeled detectable radiance. Initially, a theoretical analysis of wake vortex proxy detection by thermal radiation was realized in a series of simulations. The first stage used the SLAB plume model to simulate turbine jet exhaust plume characteristics, including exhaust gas transport dynamics and concentrations. The second stage used these plume characteristics as input to the Line By Line Radiative Transfer Model (LBLRTM) to simulate responses from both an imaging IR hyperspectral spectrometer or radiometer. These numerical simulations generated thermal imagery that was compared with previously reported wake vortex temperature data. This research is a continuation of an effort to specify the requirements for an imaging IR spectrometer or radiometer to make wake vortex measurements. Results of the two-stage simulation will be reported, including instrument specifications for wake vortex thermal detection. These results will be compared with previously reported results for IR imaging spectrometer performance.

  9. Non-exhaust PM emissions from electric vehicles

    Science.gov (United States)

    Timmers, Victor R. J. H.; Achten, Peter A. J.

    2016-06-01

    Particulate matter (PM) exposure has been linked to adverse health effects by numerous studies. Therefore, governments have been heavily incentivising the market to switch to electric passenger cars in order to reduce air pollution. However, this literature review suggests that electric vehicles may not reduce levels of PM as much as expected, because of their relatively high weight. By analysing the existing literature on non-exhaust emissions of different vehicle categories, this review found that there is a positive relationship between weight and non-exhaust PM emission factors. In addition, electric vehicles (EVs) were found to be 24% heavier than equivalent internal combustion engine vehicles (ICEVs). As a result, total PM10 emissions from EVs were found to be equal to those of modern ICEVs. PM2.5 emissions were only 1-3% lower for EVs compared to modern ICEVs. Therefore, it could be concluded that the increased popularity of electric vehicles will likely not have a great effect on PM levels. Non-exhaust emissions already account for over 90% of PM10 and 85% of PM2.5 emissions from traffic. These proportions will continue to increase as exhaust standards improve and average vehicle weight increases. Future policy should consequently focus on setting standards for non-exhaust emissions and encouraging weight reduction of all vehicles to significantly reduce PM emissions from traffic.

  10. Acceptance test report for portable exhauster POR-008/Skid F

    International Nuclear Information System (INIS)

    Kriskovich, J.R.

    1998-01-01

    Portable Exhauster POR-008 was procured via HNF-0490, Specification for a Portable Exhausted System for Waste Tank Ventilation. Prior to taking ownership, acceptance testing was performed at the vendors. However at the conclusion of testing a number of issues remained that required resolution before the exhausters could be used by Project W-320. The purpose of acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-O49O, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reports (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuum exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document

  11. Vacuum exhaustion system for thermonuclear reactor and cryopump thereof

    International Nuclear Information System (INIS)

    Kobayashi, Shigetada.

    1992-01-01

    An impurity removing device is connected to a gas exhaust side of a plasma vacuum vessel by way of a gate valve, a cryopump is connected to the exit side of the device by way of an exit valve, a fuel transfer line is disposed for transferring fuels to a fuel purification system and a vacuum pump line is disposed to an exhaust gas line. Further, a tritium monitor is disposed to an exhaustion line and the line on the side of the exit of the monitor is branched into two ways, in which a tritium transfer pipe is disposed to one of them and an atmosphere release pipe is disposed on the other of them by way of an atmosphere releasing valve. Further, a condensation shebron is disposed for flowing in and out fuel isotope gases discharged from the plasma vacuum vessel, and a funnel discharge pipe is disposed for discharging a liquefied and condensed fluid. Since the gases to be exhausted are liquefied and condensed without coagulation or coagulation products are removed while operating the pump, the exhaust gases are processed continuously to reduce tritium inventory and make the regeneration step unnecessary and remarkably improve the heat efficiency. (N.H.)

  12. Effects of prenatal exposure to diesel exhaust particles on postnatal development, behavior, genotoxicity and inflammation in mice

    DEFF Research Database (Denmark)

    Hougaard, K. S.; Jensen, K. A.; Nordly, P.

    2008-01-01

    Background: Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether...... exposure to diesel exhaust particles (DEP; NIST 2975) would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac) were exposed to 19 mg/m(3) DEP (similar to 1.10(6) particles/cm(3); mass median diameter congruent...... to 240 nm) on gestational days 9-19, for 1 h/day. Results: Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed...

  13. Economic analysis of gradual "social exhaustion" of waste management capacity.

    Science.gov (United States)

    Koide, Hideo; Nakayama, Hirofumi

    2013-12-01

    This article proposes to analyze the quantitative effects of a gradual physical and "social" exhaustion of a landfill site on an equilibrium waste management service. A gradual social exhaustion of a landfill is defined here as an upward shift of a "subjective factor" associated with the amount of waste, based on the plausible hypothesis that an individual will not accept excessive presence of landfilled waste. Physical exhaustion occurs when the absolute capacity of a landfill site decreases. The paper shows some numerical examples using specific functions and parameters, and proposes appropriate directions for three policy objectives: to decrease the equilibrium waste disposal, to increase the economic surplus of the individual and/or the waste management firm, and to lower the equilibrium collection fee. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  14. Schlieren image velocimetry measurements in a rocket engine exhaust plume

    Science.gov (United States)

    Morales, Rudy; Peguero, Julio; Hargather, Michael

    2017-11-01

    Schlieren image velocimetry (SIV) measures velocity fields by tracking the motion of naturally-occurring turbulent flow features in a compressible flow. Here the technique is applied to measuring the exhaust velocity profile of a liquid rocket engine. The SIV measurements presented include discussion of visibility of structures, image pre-processing for structure visibility, and ability to process resulting images using commercial particle image velocimetry (PIV) codes. The small-scale liquid bipropellant rocket engine operates on nitrous oxide and ethanol as propellants. Predictions of the exhaust velocity are obtained through NASA CEA calculations and simple compressible flow relationships, which are compared against the measured SIV profiles. Analysis of shear layer turbulence along the exhaust plume edge is also presented.

  15. Emotional exhaustion and defense mechanisms in intensive therapy unit nurses.

    Science.gov (United States)

    Regan, Anna; Howard, Ruth A; Oyebode, Jan R

    2009-05-01

    Contrary to its original conceptualization, research has found that emotional demands do not lead to burnout in nurses. According to psychoanalytic theory, unconscious defense mechanisms may protect nurses from conscious awareness of work-related anxiety. This prevents self-report and may explain research findings. The maturity of defense style influences how anxiety is managed. Immature defenses prevent the conscious processing necessary for resolution of anxiety. Therefore, it is hypothesized that the use of immature defenses will lead to emotional exhaustion. This cross-sectional study used questionnaires to explore the defense mechanisms of 87 Intensive Therapy Unit nurses. Although the sample endorsed a predominantly mature defense style, the use of immature defenses predicted emotional exhaustion. Also, lower levels of reported stress associated with emotional demands predicted emotional exhaustion. Although this strongly implies the mediating role of immature defense mechanisms, the results were not statistically significant.

  16. Emissions of exhaust gases and health of the person

    Science.gov (United States)

    Germanova, Tatiana; Kernozhitskaya, Anna

    2017-10-01

    The auto-road complex brings the considerable contribution to pollution and adverse change of environment. Influence of exhaust gases of cars is at the bottom of occurrence and developments of various forms of diseases. Every townsman feels the negative influence rendered by motor transport on himself. The modern city dweller is so accustomed to the smell of exhaust gases that he does not even notice it at all, continues to breathe a poisonous mixture, while neither the car nor the road can be isolated from the habitats of people. The higher the population density, the higher the need for motor transport. The health effects of emissions of exhaust gases and vapors, including regulated and unregulated pollutants, are discussed in this article.

  17. Acceptance test report for portable exhauster POR-007/Skid E

    International Nuclear Information System (INIS)

    Kriskovich, J.R.

    1998-01-01

    This document describes Acceptance Testing performed on Portable Exhauster POR-007/Skid E. It includes measurements of bearing vibration levels, pressure decay testing, programmable logic controller interlocks, high vacuum, flow and pressure control functional testing. The purpose of Acceptance testing documented by this report was to demonstrate compliance of the exhausters with the performance criteria established within HNF-0490, Rev. 1 following a repair and upgrade effort at Hanford. In addition, data obtained during this testing is required for the resolution of outstanding Non-conformance Reports (NCR), and finally, to demonstrate the functionality of the associated software for the pressure control and high vacuum exhauster operating modes provided for by W-320. Additional testing not required by the ATP was also performed to assist in the disposition and close out of receiving inspection report and for application design information (system curve). Results of this testing are also captured within this document

  18. Opportunity to reduce the exhaust gases with engine adjust

    International Nuclear Information System (INIS)

    Dimitrovski, Mile; Mucevski, Kiril

    2002-01-01

    According to statistics in the Republic of Macedonia, the number of old vehicles is about 90%. These are vehicles produced between 1975 and 1990 with classical systems for forming and burning the fuel mixture. The most of them do not have system for processing exhaust gases (catalytic converter) and are serious air pollutants of carbon monoxide (CO). In this article we try to make an attempt to reduce exhaust gases in some kinds of these vehicles with adjusting to the system for burning fuel mixture and with adjusting to the system for forming fuel mixture (carburetor). At the same time the changes on the rotate bending moment and engine power are followed. It is noticed that with a proper adjustment the emission of exhaust gases can be reduced without a serious depreciation of the rotate bending moment and the engine power. (Author)

  19. Device for the elimination of noxious components of exhaust gases

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, A

    1975-04-24

    A device for the removal of noxious components from the exhaust gases of an internal combustion engine is described. It consists of a chemical reactor installed in the tail-pipe. Behind the reactor, in the flow direction of the exhaust gases, there is a catalytic temperature sensor whose electrical output is transmitted to an analyzer which provides a signal if the reactor fails. The temperature sensor is situated directly in the waste gas duct or in a branch of the tail-pipe which is supplied with air. There is also another, catalytically inactive, temperature sensor. A failure is signalled (a) if the chemical reactor has failed, and (b) if there is not enough oxygen in the exhaust gas to keep up a chemical reaction.

  20. Effect of exhausting exercise and calcium supplementation on potassium, magnesium, copper, zinc and calcium levels in athletes

    International Nuclear Information System (INIS)

    Cinar, V.; Baltaci, A.K.; Mogulkoc, R.

    2009-01-01

    Present study was performed to determine four week calcium supplementation and athleticism exercise on plasma potassium, calcium, magnesium, cupper and zinc levels in resting and exhaustion. Research was carried out on 30 healthy male people. Group 1; Exercise, Group 2; Exercise + Calcium supplementation, Group 3; Sedentary + Calcium supplemented. All elements levels increased by exhausting exercise (P<0.05). Plasma K and Ca levels increased in exercise group after supplementation (P<0.05). Ca levels increased in exercise + supplemented group (P<0.05). This increase was much more in group three (P<0.05). Plasma Cu levels increased by Ca supplementation in sedentary (P<0.05). Exhausting exercise increased Zn levels in sedentary after supplementation (P<0.05). The results of present study show that calcium supplementation for 4 week does not have clear affect on potassium and Mg. However, calcium levels were increased by supplementation and Cu after the supplementation. It was also exhausting exercise that caused increase in all parameters. (author)

  1. Wearable Personal Exhaust Ventilation, WPEV: Improved Indoor Air Quality and Reduced Exposure to Air Exhaled from a Sick Doctor

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho D.; Barova, Maria; Melikov, Arsen K.

    2015-01-01

    pause) and a tidal flow rate of 6 L/min. A second thermal manikin and heated dummy were used to resemble lying patients. Exhaled air by the doctor was mixed with tracer gas to mimic pathogens. The wearable personal exhaust unit was positioned frontally by the mouth of the doctor at three distances: 0.......02, 0.04, and 0.06 m. It was operated at 0.25 or 0.50 L/s under mixing background ventilation at three air changes per hour. The effect of the wearable exhaust unit geometry by modifying the exhaust surface, as well as the posture of the doctor, standing or seated, was also studied. The use...... of the wearable personal exhaust resulted in cleaner air in the room compared to mixing alone at 12 air changes per hour, reducing the exposure of the two patients. The nozzle geometry and posture of the doctor affected the indoor exposure to exhaled air. The high potential to capture exhaled air makes the device...

  2. An investigation of the treatment of particulate matter from gasoline engine exhaust using non-thermal plasma

    International Nuclear Information System (INIS)

    Ye Dan; Gao Dengshan; Yu Gang; Shen Xianglin; Gu Fan

    2005-01-01

    A plasma reactor with catalysts was used to treat exhaust gas from a gasoline engine in order to decrease particulate matter (PM) emissions. The effect of non-thermal plasma (NTP) of the dielectric discharges on the removal of PM from the exhaust gas was investigated experimentally. The removal efficiency of PM was based on the concentration difference in PM for particle diameters ranging from 0.3 to 5.0 μm as measured by a particle counter. Several factors affecting PM conversion, including the density of plasma energy, reaction temperature, flow rate of exhaust gas, were investigated in the experiment. The results indicate that PM removal efficiency ranged approximately from 25 to 57% and increased with increasing energy input in the reactor, reaction temperature and residence time of the exhaust gas in the reactor. Enhanced removal of the PM was achieved by filling the discharge gap of the reactor with Cu-ZSM-5 catalyst pellets. In addition, the removal of unburned hydrocarbons was studied. Finally, available approaches for PM conversion were analyzed involving the interactions between discharge and catalytic reactions

  3. IC ENGINE SUPERCHARGING AND EXHAUST GAS RECIRCULATION USING JET COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Adhimoulame Kalaisselvane

    2010-01-01

    Full Text Available Supercharging is a process which is used to improve the performance of an engine by increasing the specific power output whereas exhaust gas recirculation reduces the NOx produced by engine because of supercharging. In a conventional engine, supercharger functions as a compressor for the forced induction of the charge taking mechanical power from the engine crankshaft. In this study, supercharging is achieved using a jet compressor. In the jet compressor, the exhaust gas is used as the motive stream and the atmospheric air as the propelled stream. When high pressure motive stream from the engine exhaust is expanded in the nozzle, a low pressure is created at the nozzle exit. Due to this low pressure, atmospheric air is sucked into the expansion chamber of the compressor, where it is mixed and pressurized with the motive stream. The pressure of the mixed stream is further increased in the diverging section of the jet compressor. A percentage volume of the pressurized air mixture is then inducted back into the engine as supercharged air and the balance is let out as exhaust. This process not only saves the mechanical power required for supercharging but also dilutes the constituents of the engine exhaust gas thereby reducing the emission and the noise level generated from the engine exhaust. The geometrical design parameters of the jet compressor were obtained by solving the governing equations using the method of constant rate of momentum change. Using the theoretical design parameters of the jet compressor, a computational fluid dinamics analysis using FLUENT software was made to evaluate the performance of the jet compressor for the application of supercharging an IC engine. This evaluation turned out to be an efficient diagnostic tool for determining performance optimization and design of the jet compressor. A jet compressor was also fabricated for the application of supercharging and its performance was studied.

  4. Noise Radiation Of A Strongly Pulsating Tailpipe Exhaust

    Science.gov (United States)

    Peizi, Li; Genhua, Dai; Zhichi, Zhu

    1993-11-01

    The method of characteristics is used to solve the problem of the propagation of a strongly pulsating flow in an exhaust system tailpipe. For a strongly pulsating exhaust, the flow may shock at the pipe's open end at some point in a pulsating where the flow pressure exceeds its critical value. The method fails if one insists on setting the flow pressure equal to the atmospheric pressure as the pipe end boundary condition. To solve the problem, we set the Mach number equal to 1 as the boundary condition when the flow pressure exceeds its critical value. For a strongly pulsating flow, the fluctuations of flow variables may be much higher than their respective time averages. Therefore, the acoustic radiation method would fail in the computation of the noise radiation from the pipe's open end. We simulate the exhaust flow out of the open end as a simple sound source to compute the noise radiation, which has been successfully applied in reference [1]. The simple sound source strength is proportional to the volume acceleration of exhaust gas. Also computed is the noise radiation from the turbulence of the exhaust flow, as was done in reference [1]. Noise from a reciprocating valve simulator has been treated in detail. The radiation efficiency is very low for the pressure range considered and is about 10 -5. The radiation efficiency coefficient increases with the square of the frequency. Computation of the pipe length dependence of the noise radiation and mass flux allows us to design a suitable length for an aerodynamic noise generator or a reciprocating internal combustion engine. For the former, powerful noise radiation is preferable. For the latter, maximum mass flux is desired because a freer exhaust is preferable.

  5. Investigations into the effect of automobile exhausts on the phenology, periodicity and productivity of some roadside trees

    Directory of Open Access Journals (Sweden)

    Ghulam Bhatti

    2014-01-01

    Full Text Available In response to a polluted atmosphere, the phenology of Ficus benyalensis and Eucalyptus sp. was highly affected. The yield of seeds and fruits of Gunincun officinale and Azadirachta indica was lessened at the polluted sites. The automobile emissions significantly reduced the productivity in G. officinale, F. bengalensis and Eucalyptus sp., whereas, A. indica was comparatively resistant to vehicle exhaust pollution. Leaf area and dry weight were significantly reduced in most of the plants.

  6. Fetal bovine serum simultaneously stimulates apoptosis and DNA synthesis in premeiotic stages of spermatogenesis in spiny dogfish (Squalus acanthias) in vitro: modulation by androgen and spermatogenic activity status.

    Science.gov (United States)

    McClusky, Leon Mendel

    2008-05-01

    Using the simple cystic spermatogenesis in the shark testis as a model, we previously reported the relative resistance of immature spermatogonia (stem cell and early-stage spermatogonia) to apoptosis in the normal testis and after spermatoxicant exposure in vivo. Apoptosis was monitored by fluorescence image analysis of living cysts, using the validated acridine orange (AO) vital staining technique. Findings show that FBS simultaneously stimulates both apoptosis and [(3)H]thymidine incorporation in immature spermatogonial clones in a concentration-dependent manner in vitro. Furthermore, androgen inhibits apoptosis and increases cyst viability, more so with 10% FBS than with 1% FBS. All the effects were as a function of spermatogenic activity status but were distinct in early-stage spermatogonial cysts isolated from testes awakening from the previous winter spermatogenic arrest period. Results are discussed in the context of the alternating germ-Sertoli cell population kinetics of early-stage spermatogonial cysts in Squalus acanthias's protracted testicular cycle.

  7. Leydig cell micronodules are a common finding in testicular biopsies from men with impaired spermatogenesis and are associated with decreased testosterone/LH ratio

    DEFF Research Database (Denmark)

    Holm, Mette; Rajpert-De Meyts, Ewa; Andersson, Anna-Maria

    2003-01-01

    To assess the biological significance of Leydig cell 'hyperplasia' in man, Leydig cell distribution, volume, and function were studied in patients with infertility or testicular cancer and in suddenly deceased controls. A total of 156 biopsies from 95 patients and 18 necropsies from 13 controls......), and were rare in testes from controls (median = 0, p = 0.02). The proportion of testicular tissue occupied by Leydig cells increased with decreasing spermatogenic capacity. In contrast, the total volume of Leydig cells per testis was roughly comparable irrespective of the histological pattern...... in the hyperstimulated testes, as reflected by an increased LH/testosterone ratio. In conclusion, Leydig cell micronodules were more frequent in biopsies with impaired spermatogenesis and associated with decreased ratios of testicular hormones to gonadotrophins. The presence of micronodules thus seems...

  8. Leydig cell micronodules are a common finding in testicular biopsies from men with impaired spermatogenesis and are associated with decreased testosterone/LH ratio

    DEFF Research Database (Denmark)

    Holm, Mette; Rajpert-De Meyts, Ewa; Andersson, Anna-Maria

    2003-01-01

    were examined using a semi-quantitative stereological method. In patients, serum concentrations of testosterone, sex hormone binding globulin (SHBG), luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol and inhibin-B were correlated with the findings on histological examination......, with the exception of testes with bilateral micronodules, which had significantly increased Leydig cell volume compared to those without micronodules. The number of micronodules correlated positively to LH (r = 0.577, p ... in the hyperstimulated testes, as reflected by an increased LH/testosterone ratio. In conclusion, Leydig cell micronodules were more frequent in biopsies with impaired spermatogenesis and associated with decreased ratios of testicular hormones to gonadotrophins. The presence of micronodules thus seems...

  9. System for exposing animals to radiolabeled diesel exhaust

    International Nuclear Information System (INIS)

    Lopez, J.A.; Wolf, I.; Wolff, R.K.; Sun, J.D.; Mokler, B.V.

    1981-01-01

    One approach to determining the deposition and fate of inhaled diesel particles is the conduct of inhalation exposure studies with radiolabeled diesel fuel. A system was designed, constructed and tested for the simultaneous exposure of animals to radiolabeled diesel exhaust and collection of large quantities of radiolabeled diesel exhaust particles from a single cylinder diesel engine. The system performance was characterized and evaluated over a range of operating conditions: 0 to 1800 watts of engine load, 1000 to 2500 rpm and dilution air rates of 1:2 and 1:10. The exposure system met required design and operating criteria for safety, portability, space and flexibility

  10. Numerical Simulation of Ionospheric Electron Concentration Depletion by Rocket Exhaust

    International Nuclear Information System (INIS)

    Huang Yong; Shi Jiaming; Yuan Zhongcai

    2011-01-01

    In terms of the diffusive process of the gases injected from rocket exhaust into the ionosphere and the relevant chemical reactions between the gases and the composition of ionosphere, the modifications in ionosphere caused by the injected hydrogen and carbon dioxide gas from the rocket exhaust are investigated. The results show that the diffusive process of the injected gases at the ionospheric height is very fast, and the injected gases can lead to a local depletion of electron concentration in the F-region. Furthermore, the plasma 'hole' caused by carbon dioxide is larger, deeper and more durable than that by the hydrogen. (astrophysics and space plasma)

  11. ATR Prohibits Replication Catastrophe by Preventing Global Exhaustion of RPA

    DEFF Research Database (Denmark)

    Toledo Lazaro, Luis Ignacio; Altmeyer, Matthias; Rask, Maj-Britt

    2013-01-01

    origin firing generates an excess of single-stranded DNA that exhausts the nuclear pool of RPA. Partial reduction of RPA accelerated fork breakage, and forced elevation of RPA was sufficient to delay such "replication catastrophe" even in the absence of ATR activity. Conversely, unscheduled origin firing...... induced breakage of stalled forks even in cells with active ATR. Thus, ATR-mediated suppression of dormant origins shields active forks against irreversible breakage via preventing exhaustion of nuclear RPA. This study elucidates how replicating genomes avoid destabilizing DNA damage. Because cancer cells...

  12. Acceptance test report MICON software exhaust fan control

    International Nuclear Information System (INIS)

    Keck, R.D.

    1998-01-01

    This test procedure specifies instructions for acceptance testing of software for exhaust fan control under Project ESPT (Energy Savings Performance Contract). The software controls the operation of two emergency exhaust fans when there is a power failure. This report details the results of acceptance testing for the MICON software upgrades. One of the modifications is that only one of the emergency fans will operate at all times. If the operating fan shuts off or fails, the other fan will start and the operating fan will be stopped

  13. Correlation between spermatogenesis disorders and rat testes CYP2E1 mRNA contents under experimental alcoholism or type I diabetes.

    Science.gov (United States)

    Shayakhmetova, Ganna M; Bondarenko, Larysa B; Matvienko, Anatoliy V; Kovalenko, Valentina M

    2014-09-01

    The aim of the study was to investigate the correlation between spermatogenesis disorders and CYP2E1 mRNA contents in testes of rats with experimental alcoholism or type I diabetes. Two pathological states characterized by CYP2E1 induction were simulated on Wistar male rats: experimental alcoholism and type I diabetes. As controls for each state, equal number of animals (of the same age and weight) were used. Morphological evaluation of rat testes was carried out. The spermatogenic epithelium state was estimated by four points system. CYP2E1 mRNA expression was rated by method of reverse transcriptase polymerase chain reaction. Pearson correlation coefficients were used for describing relationships between variables. The presence of alcoholism and diabetes-mediated quantitative and qualitative changes in male rat spermatogenic epithelium in comparison with norm has been demonstrated. The increased levels of testes CYP2E1 have been fixed simultaneously. CYP2E1 mRNA content negatively strongly correlated with spermatogenic index value (r=-0.99; Palcoholism. The strong correlation between CYP2E1 mRNA content and number of spermatogonia (r=0.99; P<0.001) and "windows" occurrence (r=0.96; P<0.001) has been fixed in diabetic rats testes. Present investigation has demonstrated that the testicular failure following chronic ethanol consumption and diabetes type I in male rats accompanied CYP2E1 mRNA over-expression in testes. The correlation between the levels of CYP2E1 mRNA in testes and spermatogenesis disorders allow supposing the involvement of CYP2E1 into the non-specific pathogenetic mechanisms of male infertility under above-mentioned pathologies. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  14. Stage and season effects on cell cycle and apoptotic activities of germ cells and Sertoli cells during spermatogenesis in the spiny dogfish (Squalus acanthias).

    Science.gov (United States)

    McClusky, L M

    2005-01-01

    To understand the processes involved in the spatial and temporal maturation of testicular cells in Squalus acanthias, we used standard morphometry, proliferating-cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) immunohistochemistry. Except for immature spermatocysts (germinal zone, GZ; early-stage pre-meiotic, E-PrM), the number of cysts in all subsequent stages and the total number of cysts in the spermatogenic progression varied seasonally. The spermatogenic cycle spans about 2 years and is interrupted by germcell clone deletion via apoptosis at the mitosis-meiosis transition in April/May, manifesting as a zone of degeneration (ZD). Rate of displacement of the ZD across the testis diameter indicates that late-stage premeiotic (L-PrM) generations 12-13 require 9-10 months to reach the mature-spermatid stage. Also, the number of cysts completing spermatogenesis is approximately 4-5-fold less than the number that entered spermatogenesis proper 2 years earlier. Pronounced gonocytogenesis in the germinal ridge was coincident with ZD formation in April/May, but it was absent in the fall when mature spermatogonial and meiotic activities had resumed. Whereas strong Sertoli cell PCNA immunoreactivity dominated the GZ cyst cell-cycle activities throughout the year, except during the spring/summer months, the spermatogonial- and Sertoli-cell PCNA indices in E-PrM cysts were inversely related. PCNA immunoreactivity in spermatocytes was seasonal and dependent on the stage of meiosis. TUNEL labelling was limited to spermatogonia and increased stage-dependently in the PrM region (L-PrM = mid-stage PrM >E-PrM >GZ), correlating with ZD formation, in a season-dependent manner. Results imply that effects of normal regulatory factors in Squalus are stage- and process-specific.

  15. Evaluation of in vitro spermatogenesis system effectiveness to study genes behavior: monitoring the expression of the testis specific 10 (Tsga10) gene as a model.

    Science.gov (United States)

    Miryounesi, Mohammad; Nayernia, Karim; Mobasheri, Maryam Beigom; Dianatpour, Mahdi; Oko, Richard; Savad, Shahram; Modarressi, Mohammad Hossein

    2014-10-01

    In vitro generation of germ cells introduces a novel approach to male infertility and provides an effective system in gene tracking studies, however many aspects of this process have remained unclear. We aimed to promote mouse embryonic stem cells (mESC) differentiation into germ cells and evaluate its effectiveness with tracking the expression of the Tsga10 during this process. mESCs were differentiated into germ cells in the presence of Retinoic Acid. Based on developmental schedule of the postnatal testis, samples were taken on the 7th, 12th, and 25th days of the culture and were subjected to expression analysis of a panel of germ cell specific genes. Expression of Tsga10 in RNA and protein levels was then analyzed. Transition from mitosis to meiosis occurred between 7th and 12th days of mESC culture and post-meiotic gene expression did not occur until the 25th day of the culture. Results showed low level of Tsga10expression in undifferentiated stem cells. During transition from meiotic to post-meiotic phase, Tsga10 expression increased in 6.6 folds. This finding is in concordance with in vivo changes during transition from pre-pubertal to pubertal stage. Localization of processed and unprocessed forms of the related protein was similar to those in vivo as well. Expression pattern of Tsga10, as a gene with critical function in spermatogenesis, is similar during in vitro and in vivo germ cell generation. The results suggest that in vitro derived germ cells could be a trusted model to study genes behavior during spermatogenesis.

  16. Pulsatile gonadotropin-releasing hormone therapy is associated with earlier spermatogenesis compared to combined gonadotropin therapy in patients with congenital hypogonadotropic hypogonadism

    Directory of Open Access Journals (Sweden)

    Jiang-Feng Mao

    2017-01-01

    Full Text Available Both pulsatile gonadotropin-releasing hormone (GnRH infusion and combined gonadotropin therapy (human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG] are effective to induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism (CHH. However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH: twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months (range: 12-27 months for the GnRH group and 28.7 ± 13.0 months (range: 12-66 months for the HCG/HMG group. The median time to first sperm appearance was 6 months (95% confidence interval [CI]: 1.6-10.4 in the GnRH group versus 18 months (95% CI: 16.4-20.0 in the HCG/HMG group (P 1 × 10 6 ml−1 was 43.7% ± 20.4% (16 samples in the GnRH group versus 43.2% ± 18.1% (153 samples in the HCG/HMG group (P = 0.921. Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group (8.3 ± 4.6 vs 16.2 ± 8.2 nmol l−1 , P < 0.001. Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.

  17. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 1: background to spermatogenesis, spermatogonia, and spermatocytes.

    Science.gov (United States)

    Hermo, Louis; Pelletier, R-Marc; Cyr, Daniel G; Smith, Charles E

    2010-04-01

    Spermatogenesis, a study of germ cell development, is a long, orderly, and well-defined process occurring in seminiferous tubules of the testis. It is a temporal event whereby undifferentiated spermatogonial germ cells evolve into maturing spermatozoa over a period of several weeks. Spermatogenesis is characterized by three specific functional phases: proliferation, meiosis, and differentiation, and it involves spermatogonia, spermatocytes, and spermatids. Germ cells at steps of development form various cellular associations or stages, with 6, 12, and 14 specific stages being identified in human, mouse, and rat, respectively. The stages evolve over time in a given area of the seminiferous tubule forming a cycle of the seminiferous epithelium that has a well-defined duration for a given species. In this part, we discuss the proliferation and meiotic phase whereby spermatogonia undergo several mitotic divisions to form spermatocytes that undergo two meiotic divisions to form haploid spermatids. In the rat, spermatogonia can be subdivided into several classes: stem cells (A(s)), proliferating cells (A(pr), A(al)), and differentiating cells (A(1)-A(4), In, B). They are dependent on a specific microenvironment (niche) contributed by Sertoli, myoid, and Leydig cells for proper development. Spermatogonia possess several surface markers whereby they can be identified from each other. During meiosis, spermatocytes undergo chromosomal pairing, synapsis, and genetic exchange as well as transforming into haploid cells following meiosis. The meiotic cells form specific structural entities such as the synaptonemal complex and sex body. Many genes involved in spermatogonial renewal and the meiotic process have been identified and shown to be essential for this event. Copyright 2009 Wiley-Liss, Inc.

  18. Electron beam treatment of simulated marine diesel exhaust gases

    Directory of Open Access Journals (Sweden)

    Licki Janusz

    2015-09-01

    Full Text Available The exhaust gases from marine diesel engines contain high SO2 and NOx concentration. The applicability of the electron beam flue gas treatment technology for purification of marine diesel exhaust gases containing high SO2 and NOx concentration gases was the main goal of this paper. The study was performed in the laboratory plant with NOx concentration up to 1700 ppmv and SO2 concentration up to 1000 ppmv. Such high NOx and SO2 concentrations were observed in the exhaust gases from marine high-power diesel engines fuelled with different heavy fuel oils. In the first part of study the simulated exhaust gases were irradiated by the electron beam from accelerator. The simultaneous removal of SO2 and NOx were obtained and their removal efficiencies strongly depend on irradiation dose and inlet NOx concentration. For NOx concentrations above 800 ppmv low removal efficiencies were obtained even if applied high doses. In the second part of study the irradiated gases were directed to the seawater scrubber for further purification. The scrubbing process enhances removal efficiencies of both pollutants. The SO2 removal efficiencies above 98.5% were obtained with irradiation dose greater than 5.3 kGy. For inlet NOx concentrations of 1700 ppmv the NOx removal efficiency about 51% was obtained with dose greater than 8.8 kGy. Methods for further increase of NOx removal efficiency are presented in the paper.

  19. Systems for eliminating pathogens from exhaust air of animal houses

    NARCIS (Netherlands)

    Aarnink, A.J.A.; Landman, W.J.M.; Melse, R.W.; Huynh Thi Thanh Thuy,

    2005-01-01

    Recent outbreaks of highly infectious viral diseases like swine fever and avian influenza in The Netherlands have shown that despite extensive bio-security measures aiming at minimizing physical contacts between farms, disease spread could not be halted. Dust in exhaust air from swine and chicken

  20. 7 CFR 400.56 - Administrative appeal exhaustion.

    Science.gov (United States)

    2010-01-01

    ... contained in 7 CFR part 400, subpart J. Administrative remedies through the appeal process must be exhausted prior to any action for judicial review. The approved APH yield determined as a result of the appeal process will be the yield applicable to the crop year. ...

  1. Exhaustive Weakly Wandering Sequences and Alpha-type Transformations

    Directory of Open Access Journals (Sweden)

    Stanley Eigen

    2015-12-01

    Full Text Available An increasing sequence of integers, $\\mathbb{B}$, is given for which there exists a family of ergodic, infinite measure preserving transformations $T_\\alpha$, $0 \\leq \\alpha \\leq 1$ so that (1 $T_\\alpha$ is of $\\alpha$-type and (2 $\\mathbb{B}$ is an exhaustive weakly wandering sequence for each $T_\\alpha$.

  2. A Numerical and Experimental Study of Local Exhaust Capture Efficiency

    DEFF Research Database (Denmark)

    Madsen, U.; Breum, N. O.; Nielsen, Peter Vilhelm

    1993-01-01

    Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods for estim...... location is less important for the case studied. The choice of sampling strategy to obtain a representative background concentration is essential as substantial differences on direct capture efficiency are found. Recommendations are given......Direct capture efficiency of a local exhaust system is defined by introducing an imaginary control box surrounding the contaminant source and the exhaust opening. The imaginary box makes it possible to distinguish between contaminants directly captured and those that escape. Two methods...... for estimation of direct capture efficiency are given: (1) a numerical method based on the time-averaged Navier-Stokes equations for turbulent flows; and (2) a field method based on a representative background concentration. Direct capture efficiency is sensitive to the size of the control box, whereas its...

  3. Fast exhaustive search for polynomial systems in F2

    NARCIS (Netherlands)

    Bouillaguet, C.; Chen, H.-C.; Cheng, C.M.; Chou, T.; Niederhagen, R.F.; Shamir, A.; Yang, B.Y.

    2010-01-01

    Abstract. We analyze how fast we can solve general systems of multivariate equations of various low degrees over F2; this is a well known hard problem which is important both in itself and as part of many types of algebraic cryptanalysis. Compared to the standard exhaustive-search technique, our

  4. Fast exhaustive search for polynomial systems in F2

    NARCIS (Netherlands)

    Bouillaguet, C.; Chen, H.-C.; Cheng, C.M.; Chou, T.; Niederhagen, R.F.; Shamir, A.; Yang, B.Y.; Mangard, S.; Standaert, F.X.

    2010-01-01

    Abstract: We analyze how fast we can solve general systems of multivariate equations of various low degrees over $F_2$; this is a well known hard problem which is important both in itself and as part of many types of algebraic cryptanalysis. Compared to the standard exhaustive search technique, our

  5. Optimal Design of an Automotive Exhaust Thermoelectric Generator

    Science.gov (United States)

    Fagehi, Hassan; Attar, Alaa; Lee, Hosung

    2018-07-01

    The consumption of energy continues to increase at an exponential rate, especially in terms of conventional automobiles. Approximately 40% of the applied fuel into a vehicle is lost as waste exhausted to the environment. The desire for improved fuel efficiency by recovering the exhaust waste heat in automobiles has become an important subject. A thermoelectric generator (TEG) has the potential to convert exhaust waste heat into electricity as long as it is improving fuel economy. The remarkable amount of research being conducted on TEGs indicates that this technology will have a bright future in terms of power generation. The current study discusses the optimal design of the automotive exhaust TEG. An experimental study has been conducted to verify the model that used the ideal (standard) equations along with effective material properties. The model is reasonably verified by experimental work, mainly due to the utilization of the effective material properties. Hence, the thermoelectric module that was used in the experiment was optimized by using a developed optimal design theory (dimensionless analysis technique).

  6. Herpes viruses, cytokines, and altered hemostasis in vital exhaustion.

    NARCIS (Netherlands)

    Ven, A.J.A.M. van der; Diest, R. van; Hamulyak, K.; Maes, M.; Bruggeman, C.A.; Appels, A.

    2003-01-01

    OBJECTIVE: Infections with herpes viruses have been implicated in the pathogenesis of atherosclerosis. We tested the hypothesis that vital exhaustion (VE) is associated with multiple herpesvirus infections, such as herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, and

  7. Exhaustible-resource theory and the uranium market

    International Nuclear Information System (INIS)

    Hsieh, Y.L.

    1982-01-01

    Exhaustible-resource theory has been developed rapidly by economists since the OPEC shocks of 1973-1974 and the theory now provides a framework for analyzing the optimal production pattern for resource commodities. However, applications of the theory to particular markets, such as crude oil, have not provided accurate predictions due no doubt to theoretical problems in explaining exploration and discovery events, market organization changes, and uncertainty. This thesis investigated the uranium market in an effort to determine how well the exhaustible-resource theory explains the past price and quantity time paths of this energy resource, and what might be expected in the future. The exhaustible-resource theory was first developed in a form appropriate to an application to the uranium market. An econometric simulation model that combines the history of uranium price formation and the exhaustible-resource theory was developed to forecast future uranium prices. The model was designed not only to reflect the physical processes of drilling activities, changing reserves, production, and prices of uranium through individual equations, but also to account for the interaction of all these interrelationships at the same time

  8. Exhaustive Search for Sparse Variable Selection in Linear Regression

    Science.gov (United States)

    Igarashi, Yasuhiko; Takenaka, Hikaru; Nakanishi-Ohno, Yoshinori; Uemura, Makoto; Ikeda, Shiro; Okada, Masato

    2018-04-01

    We propose a K-sparse exhaustive search (ES-K) method and a K-sparse approximate exhaustive search method (AES-K) for selecting variables in linear regression. With these methods, K-sparse combinations of variables are tested exhaustively assuming that the optimal combination of explanatory variables is K-sparse. By collecting the results of exhaustively computing ES-K, various approximate methods for selecting sparse variables can be summarized as density of states. With this density of states, we can compare different methods for selecting sparse variables such as relaxation and sampling. For large problems where the combinatorial explosion of explanatory variables is crucial, the AES-K method enables density of states to be effectively reconstructed by using the replica-exchange Monte Carlo method and the multiple histogram method. Applying the ES-K and AES-K methods to type Ia supernova data, we confirmed the conventional understanding in astronomy when an appropriate K is given beforehand. However, we found the difficulty to determine K from the data. Using virtual measurement and analysis, we argue that this is caused by data shortage.

  9. Test Program for High Efficiency Gas Turbine Exhaust Diffuser

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Thomas R.

    2009-12-31

    This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

  10. The isotopic composition of CO in vehicle exhaust

    NARCIS (Netherlands)

    Naus, S.; Röckmann, T.; Popa, M.E.

    2018-01-01

    We investigated the isotopic composition of CO in the exhaust of individual vehicles. Additionally, the CO 2 isotopes, and the CO:CO 2 , CH 4 :CO 2 and H 2 :CO gas ratios were measured. This was done under idling and revving conditions, and for three vehicles in a full driving cycle on a testbench.

  11. Organic positive ions in aircraft gas-turbine engine exhaust

    Science.gov (United States)

    Sorokin, Andrey; Arnold, Frank

    Volatile organic compounds (VOCs) represent a significant fraction of atmospheric aerosol. However the role of organic species emitted by aircraft (as a consequence of the incomplete combustion of fuel in the engine) in nucleation of new volatile particles still remains rather speculative and requires a much more detailed analysis of the underlying mechanisms. Measurements in aircraft exhaust plumes have shown the presence of both different non-methane VOCs (e.g. PartEmis project) and numerous organic cluster ions (MPIK-Heidelberg). However the link between detected organic gas-phase species and measured mass spectrum of cluster ions is uncertain. Unfortunately, up to now there are no models describing the thermodynamics of the formation of primary organic cluster ions in the exhaust of aircraft engines. The aim of this work is to present first results of such a model development. The model includes the block of thermodynamic data based on proton affinities and gas basicities of organic molecules and the block of non-equilibrium kinetics of the cluster ions evolution in the exhaust. The model predicts important features of the measured spectrum of positive ions in the exhaust behind aircraft. It is shown that positive ions emitted by aircraft engines into the atmosphere mostly consist of protonated and hydrated organic cluster ions. The developed model may be explored also in aerosol investigations of the background atmosphere as well as in the analysis of the emission of fine aerosol particles by automobiles.

  12. Base flow and exhaust plume interaction. Part 1 : Experimental study

    NARCIS (Netherlands)

    Schoones, M.M.J.; Bannink, W.J.

    1998-01-01

    An experimental study of the flow field along an axi-symmetric body with a single operating exhaust nozzle has been performed in the scope of an investigation on base flow-jet plume interactions. The structure of under-expanded jets in a co-flowing supersonic free stream was described using

  13. Generation and characterization of gasoline engine exhaust inhalation exposure atmospheres.

    Science.gov (United States)

    McDonald, Jacob D; Barr, Edward B; White, Richard K; Kracko, Dean; Chow, Judith C; Zielinska, Barbara; Grosjean, Eric

    2008-10-01

    Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 4.3-L gasoline engine coupled to a dynamometer and operated on an adapted California Unified Driving Cycle. Exposure levels were maintained at three different dilution rates. One chamber at the lowest dilution had particles removed by filtration. Each exposure atmosphere was characterized for particle mass, particle number, particle size distribution, and detailed chemical speciation. The majority of the mass in the exposure atmospheres was gaseous carbon monoxide, nitrogen oxides, and volatile organics, with small amounts of particle-bound carbon/ions and metals. The atmospheres varied according to the cycle, with the largest spikes in volatile organic and inorganic species shown during the "cold start" portion of the cycle. Ammonia present from the exhaust and rodents interacted with the gasoline exhaust to form secondary inorganic particles, and an increase in exhaust resulted in higher proportions of secondary inorganics as a portion of the total particle mass. Particle size had a median of 10-20 nm by number and approximately 150 nm by mass. Volatile organics matched the composition of the fuel, with large proportions of aliphatic and aromatic hydrocarbons coupled to low amounts of oxygenated organics. A new measurement technique revealed organics reacting with nitrogen oxides have likely resulted in measurement bias in previous studies of combustion emissions. Identified and measured particle organic species accounted for about 10% of total organic particle mass and were mostly aliphatic acids and polycyclic aromatic hydrocarbons.

  14. Technique for radiation treatment of exhaust gas due to combustion

    International Nuclear Information System (INIS)

    Machi, Sueo

    1978-01-01

    As the Japanese unique research in the field of preservation of environment, the technique to remove simultaneously sulphur dioxide and nitrogen oxides in exhaust gas using electron beam irradiation is noteworthy. This research was started by the experiment in the central research laboratory of Ebara Manufacturing Co., Ltd., in which it was found that the sulphur dioxide of initial concentration of 1,000 ppm was almost completely vanished when the exhaust gas of heavy oil combustion in a batch type vessel was irradiated for 9 minutes by electron beam. Based on this experiment, JAERI installed a continuous irradiation equipment with a large accelerator, and has investigated the effect of various parameters such as dose rate, irradiation temperature, total dose and agitation. This resulted in the remarkable finding that nitrogen oxides were also completely removed as well as sulphur dioxide when the exhaust gas containing both sulphur dioxide and nitrogen oxides was irradiated for a few seconds. In this case, if water of about 0.3% is added, removal rate of sulphur dioxide is greatly increased. The research group of University of Tokyo obtained other findings concerning removal rates. Then, after the pilot plant stage in Ebara Manufacturing Co., Ltd. from 1974, the test plant of exhaust gas treatment for a sintering machine, having the capacity of 3,000 Nm 3 /hr, has been constructed in Yawata Works of Nippon Steel Corp. This is now operating properly. (Wakatsuki, Y.)

  15. Occupational exposure to diesel engine exhaust and serum cytokine levels

    NARCIS (Netherlands)

    Dai, Yufei; Ren, Dianzhi; Bassig, Bryan A.; Vermeulen, Roel; Hu, Wei; Niu, Yong; Duan, Huawei; Ye, Meng; Meng, Tao; Xu, Jun; Li, Ping; Shen, Meili; Yang, Jufang; Fu, Wei; Meliefste, Kees; Silverman, Debra T.; Rothman, Nathaniel; Lan, Qing; Zheng, Yuxin

    The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response

  16. Psychic and moral exhaustion in primary care workers

    Directory of Open Access Journals (Sweden)

    Priscilla Brandão Bacci Pegoraro

    2017-12-01

    Full Text Available Abstract OBJECTIVE To report the experience of developing a workshop proposal to assist local managers with the identification, management and prevention of primary care workers' psychic and moral exhaustion. METHOD The workshop was developed through a literature review performed between November 2014 and June 2015. The temporal cut considered studies of the ten previous years. The selection included studies describing collective interventions for situations generating psychic and moral exhaustion, preferably in primary care services. RESULTS Thirty-five articles were analyzed. The workshop provides five meetings with an average duration of one hour. The themes are: awareness; recognizing personal stress; dealing with personal stress; recognizing team stress; and dealing with team stress. The workshop is based on five key principles: detection and coping; attention to interpersonal relationships; communication; self-knowledge and mindfulness. CONCLUSION Psychic and moral exhaustion may reflect negatively on workers' health, the care, and the organization. The proposal of measures to recognize, deal with and prevent psychic and moral exhaustion is relevant and strategic in the constant search for improvement of satisfaction and quality.

  17. 40 CFR 86.240-94 - Exhaust sample analysis.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Exhaust sample analysis. 86.240-94 Section 86.240-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... 1994 and Later Model Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium...

  18. Optimal Design of an Automotive Exhaust Thermoelectric Generator

    Science.gov (United States)

    Fagehi, Hassan; Attar, Alaa; Lee, Hosung

    2018-04-01

    The consumption of energy continues to increase at an exponential rate, especially in terms of conventional automobiles. Approximately 40% of the applied fuel into a vehicle is lost as waste exhausted to the environment. The desire for improved fuel efficiency by recovering the exhaust waste heat in automobiles has become an important subject. A thermoelectric generator (TEG) has the potential to convert exhaust waste heat into electricity as long as it is improving fuel economy. The remarkable amount of research being conducted on TEGs indicates that this technology will have a bright future in terms of power generation. The current study discusses the optimal design of the automotive exhaust TEG. An experimental study has been conducted to verify the model that used the ideal (standard) equations along with effective material properties. The model is reasonably verified by experimental work, mainly due to the utilization of the effective material properties. Hence, the thermoelectric module that was used in the experiment was optimized by using a developed optimal design theory (dimensionless analysis technique).

  19. Heat pipes and use of heat pipes in furnace exhaust

    Science.gov (United States)

    Polcyn, Adam D.

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  20. Neuropsychological sequelae of work-stress-related exhaustion.

    Science.gov (United States)

    Österberg, Kai; Skogsliden, Sofia; Karlson, Björn

    2014-01-01

    The aim was to assess long-term cognitive performance after substantial recovery from work-stress-related exhaustion, in relation to subjective cognitive complaints and return to active work. In total, 54 patients previously diagnosed with work-stress-related exhaustion participated in a neuropsychological examination ∼2 years after initial sick leave. Most participants were substantially recovered at follow-up, with only 13% still meeting the criteria for exhaustion disorder suggested by the Swedish National Board of Health and Welfare. When participants' scores on 14 neuropsychological tests were compared to a matched group of 50 controls, the former patient group showed lower performance mainly on attention tests of the reaction time type, but also slightly lower scores on visuo-spatial constructional ability. However, the former patient group performed better than controls on two memory tests and, in part, on a test of simultaneous capacity. Self-ratings of everyday cognitive problems remained significantly higher in the former patient group than among controls, but the extent of self-rated cognitive problems was generally unrelated to performance on the neuropsychological tests. No relationship between performance on these tests and the extent of work resumption was observed. In summary, persons with previous work-stress-related exhaustion showed persistent signs of a minor attention deficit, despite considerable general recovery and return to work.

  1. A Lagrangian Simulation of Subsonic Aircraft Exhaust Emissions

    Science.gov (United States)

    Schoeberl, M. R.; Morris, G. A.

    1999-01-01

    To estimate the effect of subsonic and supersonic aircraft exhaust on the stratospheric concentration of NO(y), we employ a trajectory model initialized with air parcels based on the standard release scenarios. The supersonic exhaust simulations are in good agreement with 2D and 3D model results and show a perturbation of about 1-2 ppbv of NO(y) in the stratosphere. The subsonic simulations show that subsonic emissions are almost entirely trapped below the 380 K potential temperature surface. Our subsonic results contradict results from most other models, which show exhaust products penetrating above 380 K, as summarized. The disagreement can likely be attributed to an excessive vertical diffusion in most models of the strong vertical gradient in NO(y) that forms at the boundary between the emission zone and the stratosphere above 380 K. Our results suggest that previous assessments of the impact of subsonic exhaust emission on the stratospheric region above 380 K should be considered to be an upper bound.

  2. How job demands affect partners' experience of exhaustion : integrating work-family conflict and crossover theory

    NARCIS (Netherlands)

    Bakker, A.B.; Demerouti, E.; Dollard, M.F.

    2008-01-01

    This study among 168 couples of dual-earner parents uses insights from previous work-family conflict and crossover research to propose an integrative model delineating how job demands experienced by men and women carry over to the home domain. The authors hypothesized that for both men and women,

  3. Factors affecting cleanup of exhaust gases from a pressurized, fluidized-bed coal combustor

    Science.gov (United States)

    Rollbuhler, R. J.; Kobak, J. A.

    1980-01-01

    The cleanup of effluent gases from the fluidized-bed combustion of coal is examined. Testing conditions include the type and feed rate of the coal and the sulfur sorbent, the coal-sorbent ratio, the coal-combustion air ratio, the depth of the reactor fluidizing bed, and the technique used to physically remove fly ash from the reactor effluent gases. Tests reveal that the particulate loading matter in the effluent gases is a function not only of the reactor-bed surface gas velocity, but also of the type of coal being burnt and the time the bed is operating. At least 95 percent of the fly ash particules in the effluent gas are removed by using a gas-solids separator under controlled operating conditions. Gaseous pollutants in the effluent (nitrogen and sulfur oxides) are held within the proposed Federal limits by controlling the reactor operating conditions and the type and quantity of sorbent material.

  4. Heat exhaustion in a deep underground metalliferous mine.

    Science.gov (United States)

    Donoghue, A M; Sinclair, M J; Bates, G P

    2000-03-01

    To examine the incidence, clinical state, personal risk factors, haematology, and biochemistry of heat exhaustion occurring at a deep underground metalliferous mine. To describe the underground thermal conditions associated with the occurrence of heat exhaustion. A 1 year prospective case series of acute heat exhaustion was undertaken. A history was obtained with a structured questionnaire. Pulse rate, blood pressure, tympanic temperature, and specific gravity of urine were measured before treatment. Venous blood was analysed for haematological and biochemical variables, during the acute presentation and after recovery. Body mass index (BMI) and maximum O2 consumption (VO2 max) were measured after recovery. Psychrometric wet bulb temperature, dry bulb temperature, and air velocity were measured at the underground sites where heat exhaustion had occurred. Air cooling power and psychrometric wet bulb globe temperature were derived from these data. 106 Cases were studied. The incidence of heat exhaustion during the year was 43.0 cases/million man-hours. In February it was 147 cases/million man-hours. The incidence rate ratio for mines operating below 1200 m compared with those operating above 1200 m was 3.17. Mean estimated fluid intake was 0.64 l/h (SD 0.29, range 0.08-1.50). The following data were increased in acute presentation compared with recovery (p value, % of acute cases above the normal clinical range): neutrophils (p air velocity was 0.54 m/s (SD 0.57, range 0.00-4.00). Mean air cooling power was 148 W/m2 (SD 49, range 33-290) Mean psychrometric wet bulb globe temperature was 31.5 degrees C (SD 2.0, range 25.2-35.3). Few cases (air velocity > 1.56 m/s, air cooling power > 248 W/m2, or psychrometric wet bulb globe temperature air cooling power > 250 W/m2 at all underground work sites.

  5. Effect of exhaust emissions on carbon monoxide levels in employees working at indoor car wash facilities.

    Science.gov (United States)

    Topacoglu, H; Katsakoglou, S; Ipekci, A

    2014-01-01

    Exhaust emissions from motor vehicles threaten the environment and human health. Carbon monoxide (CO) poisoning, especially the use of exhaust gas CO in suicidal attempts is well known in the literature. Recently, indoor car wash facilities established in large shopping malls with closed parking, lots is a new risk area that exposes car wash employees to prolonged periods of high level CO emissions from cars. The aim of this study was to investigate how carboxyhemoglobin (COHb) blood levels of employees get affected in confined areas with relatively poor air circulation. Twenty male volunteers working in indoor parking car wash facilities were included in the study. Participants were informed about the aim of this study and their consent was obtained. Their pulse COHb levels were measured twice, at the beginning and at the end of the working day using Rad-57 pulse CO-oximeter device, allowing non-invasive measurement of COHb blood levels to compare the changes in their COHb levels before and after work. The mean age of the male volunteers was 29.8 ± 11.9 (range 18-55). While the mean COHb levels measured at the start of the working day was 2.1 ± 2.0 (range 0-9), it was increased to 5.2 ± 3.3 (range 1-15) at the end of work shift (Wilcoxon test, p car wash facility employees is directly impacted and gets elevated by motor vechile exhaust emissions. For the health of the employees at indoor parking car wash facilities, stricter precautions are needed and the government should not give permit to such operations.

  6. The diesel exhaust in miners study: IV. Estimating historical exposures to diesel exhaust in underground non-metal mining facilities.

    NARCIS (Netherlands)

    Vermeulen, R.; Coble, J.B.; Lubin, J.H.; Portengen, L.; Blair, A.; Attfield, M.D.; Silverman, D.T.; Stewart, P.A.

    2010-01-01

    We developed quantitative estimates of historical exposures to respirable elemental carbon (REC) for an epidemiologic study of mortality, including lung cancer, among diesel-exposed miners at eight non-metal mining facilities [the Diesel Exhaust in Miners Study (DEMS)]. Because there were no

  7. The Diesel Exhaust in Miners study: a nested case-control study of lung cancer and diesel exhaust

    NARCIS (Netherlands)

    Silverman, D.T.; Samanic, C.; Lubin, J.H.; Blair, A.; Stewart, P.A.; Vermeulen, R.; Schleiff, P.L.; Travis, W.D.; Ziegler, R.; Wacholder, S.; Attfield, M.D.

    2012-01-01

    BACKGROUND Most studies of the association between diesel exhaust exposure and lung cancer suggest a modest, but consistent, increased risk. However, to our knowledge, no study to date has had quantitative data on historical diesel exposure coupled with adequate sample size to evaluate the

  8. Experiment and CFD simulation of exhaust tube in highvoltage circuit breaker

    Directory of Open Access Journals (Sweden)

    Ye Xiangyang

    2018-01-01

    Full Text Available In a high-voltage circuit breaker, the exhaust tube connects the arc zone with the exhaust volume. During the arc interruption process, the exhaust tube transports the hot gas from the arc interruption zone to the exhaust volume through its distributed holes. The design of a high performance exhaust tube in the circuit breaker development aims for well controlled hot gas evacuation mass flow and pressure waves. In this paper, the exhaust tube behaviour is investigated using Computational Fluid Dynamics (CFD. To verify the CFD simulation, a basic experimental study with pressure measurements at different positions of the exhaust tube is performed. Further, the design parameters influencing the exhaust tube behaviour and circuit breaker performance are investigated and discussed.

  9. Evaluation of the Effect of Exhausts from Liquid and Solid Rockets on Ozone Layer

    Science.gov (United States)

    Yamagiwa, Yoshiki; Ishimaki, Tetsuya

    This paper reports the analytical results of the influences of solid rocket and liquid rocket exhausts on ozone layer. It is worried about that the exhausts from solid propellant rockets cause the ozone depletion in the ozone layer. Some researchers try to develop the analytical model of ozone depletion by rocket exhausts to understand its physical phenomena and to find the effective design of rocket to minimize its effect. However, these models do not include the exhausts from liquid rocket although there are many cases to use solid rocket boosters with a liquid rocket at the same time in practical situations. We constructed combined analytical model include the solid rocket exhausts and liquid rocket exhausts to analyze their effects. From the analytical results, we find that the exhausts from liquid rocket suppress the ozone depletion by solid rocket exhausts.

  10. Analysis of the effects of meteorology on aircraft exhaust dispersion and deposition using a Lagrangian particle model

    Energy Technology Data Exchange (ETDEWEB)

    Pecorari, Eliana, E-mail: eliana.pecorari@unive.it [Department of Environmental Science, Informatics and Statistics, University Ca’ Foscari Venice, Calle Larga Santa Marta 2137, Dorsoduro, 30123 Venezia (Italy); Mantovani, Alice [OSMOTECH S.r.l., via Francesco Sforza, 15, 20122 Milano (Italy); Franceschini, Chiara [Department of Environmental Science, Informatics and Statistics, University Ca’ Foscari Venice, Calle Larga Santa Marta 2137, Dorsoduro, 30123 Venezia (Italy); Bassano, Davide [SAVE S.p.A., Marco Polo Venice airport viale G. Galilei 30/1, 30173 Tessera-Venezia (Italy); Palmeri, Luca [Department of Industrial Engineering, University of Padova, v. Marzolo 9, 35131 Padova (Italy); Rampazzo, Giancarlo [Department of Environmental Science, Informatics and Statistics, University Ca’ Foscari Venice, Calle Larga Santa Marta 2137, Dorsoduro, 30123 Venezia (Italy)

    2016-01-15

    The risk of air quality degradation is of considerable concern particularly for those airports that are located near urban areas. The ability to quantitatively predict the effects of air pollutants originated by airport operations is important for assessing air quality and the related impacts on human health. Current emission regulations have focused on local air quality in the proximity of airports. However, an integrated study should consider the effects of meteorological events, at both regional and local level, that can affect the dispersion and the deposition of exhausts. Rigorous scientific studies and extensive experimental data could contribute to the analysis of the impacts of airports expansion plans. This paper is focused on the analysis of the effects of meteorology on aircraft emission for the Marco Polo Airport in Venice. This is the most important international airport in the eastern part of the Po’ Valley, one of the most polluted area in Europe. Air pollution is exacerbated by meteorology that is a combination of large and local scale effects that do not allow significant dispersion. Moreover, the airport is located near Venice, a city of noteworthy cultural and architectural relevance, and nearby the lagoon that hosts several areas of outstanding ecological importance at European level (Natura 2000 sites). Dispersion and deposit of the main aircraft exhausts (NOx, HC and CO) have been evaluated by using a Lagrangian particle model. Spatial and temporal aircraft exhaust dispersion has been analyzed for LTO cycle. Aircraft taxiing resulted to be the most impacting aircraft operation especially for the airport working area and its surroundings, however occasionally peaks may be observed even at high altitudes when cruise mode starts. Mixing height can affect concentrations more significantly than the concentrations in the exhausts themselves. An increase of HC and CO concentrations (15–50%) has been observed during specific meteorological events

  11. Analysis of the effects of meteorology on aircraft exhaust dispersion and deposition using a Lagrangian particle model

    International Nuclear Information System (INIS)

    Pecorari, Eliana; Mantovani, Alice; Franceschini, Chiara; Bassano, Davide; Palmeri, Luca; Rampazzo, Giancarlo

    2016-01-01

    The risk of air quality degradation is of considerable concern particularly for those airports that are located near urban areas. The ability to quantitatively predict the effects of air pollutants originated by airport operations is important for assessing air quality and the related impacts on human health. Current emission regulations have focused on local air quality in the proximity of airports. However, an integrated study should consider the effects of meteorological events, at both regional and local level, that can affect the dispersion and the deposition of exhausts. Rigorous scientific studies and extensive experimental data could contribute to the analysis of the impacts of airports expansion plans. This paper is focused on the analysis of the effects of meteorology on aircraft emission for the Marco Polo Airport in Venice. This is the most important international airport in the eastern part of the Po’ Valley, one of the most polluted area in Europe. Air pollution is exacerbated by meteorology that is a combination of large and local scale effects that do not allow significant dispersion. Moreover, the airport is located near Venice, a city of noteworthy cultural and architectural relevance, and nearby the lagoon that hosts several areas of outstanding ecological importance at European level (Natura 2000 sites). Dispersion and deposit of the main aircraft exhausts (NOx, HC and CO) have been evaluated by using a Lagrangian particle model. Spatial and temporal aircraft exhaust dispersion has been analyzed for LTO cycle. Aircraft taxiing resulted to be the most impacting aircraft operation especially for the airport working area and its surroundings, however occasionally peaks may be observed even at high altitudes when cruise mode starts. Mixing height can affect concentrations more significantly than the concentrations in the exhausts themselves. An increase of HC and CO concentrations (15–50%) has been observed during specific meteorological events

  12. Effect of nocturnal exhaustion exercise on the metabolism of selected elements

    Directory of Open Access Journals (Sweden)

    Patlar Suleyman

    2014-01-01

    Full Text Available The present study aims to examine how exercise performed until fatigue at night affects element distribution in the serum. The study examined 10 healthy sedentary males who were not actively engaged in any particular sport and whose mean age was 23.00±0.25 years, mean height 177.79±2.25 cm, and mean weight 70.70±1.63 kg. Blood samples were collected from the subjects at midnight twice: during rest before exercise and after exercise. Serum phosphorus, sodium, potassium, sulfur (mmol/L, cobalt, boron, cadmium, chrome, nickel, manganese, molybdenum, copper, iron, zinc and calcium levels (mg/L were measured using atomic emission spectroscopy (ICP-AES. Exhaustion exercise performed at night brought about a decrease in copper levels only (p<0.05, while elevating levels of potassium, sodium, magnesium, calcium, iron, zinc, manganese, nickel, selenium, molybdenum, chrome, cobalt, lead and cadmium (p<0.05. The results of the study demonstrate that nighttime exercise until exhaustion significantly alters element metabolism.

  13. Investigation of baffle configuration effect on the performance of exhaust mufflers

    Directory of Open Access Journals (Sweden)

    Ahmed Elsayed

    2017-09-01

    Full Text Available Using baffles in exhaust mufflers is known to improve their transmission loss. The baffle cut ratio should affect the muffler performance analogous to a shell-and-tube heat exchanger. To the authors’ knowledge, there is no previous assessment reported in literature of the effects that the baffle cut ratio configuration has on acoustic response and back pressure. This investigation presents a parametric study on the effect of baffle configuration on transmission loss and pressure drop predicted. The effect of (i the baffle cut ratio and baffle spacing, (ii the number of baffle holes, and (iii the hole distribution for their effect on transmission loss was investigated. Results show that decreasing the baffle cut ratio tends to increase the transmission loss at intermediate frequencies by up to 45%. Decreasing the spacing between muffler plates was shown to enhance the muffler transmission loss by 40%. To assess the baffle effect on flow, the OpenFoam CFD libraries were utilized using the thermal baffle approach model. Baffles were found to cause sudden drop in fluid temperature in axial flow direction. The outlet exhaust gases temperature was found to decrease by 15% as the baffle cut ratio changed from 75% to 25%.

  14. Analysis of a Temperature-Controlled Exhaust Thermoelectric Generator During a Driving Cycle

    Science.gov (United States)

    Brito, F. P.; Alves, A.; Pires, J. M.; Martins, L. B.; Martins, J.; Oliveira, J.; Teixeira, J.; Goncalves, L. M.; Hall, M. J.

    2016-03-01

    Thermoelectric generators can be used in automotive exhaust energy recovery. As car engines operate under wide variable loads, it is a challenge to design a system for operating efficiently under these variable conditions. This means being able to avoid excessive thermal dilution under low engine loads and being able to operate under high load, high temperature events without the need to deflect the exhaust gases with bypass systems. The authors have previously proposed a thermoelectric generator (TEG) concept with temperature control based on the operating principle of the variable conductance heat pipe/thermosiphon. This strategy allows the TEG modules’ hot face to work under constant, optimized temperature. The variable engine load will only affect the number of modules exposed to the heat source, not the heat transfer temperature. This prevents module overheating under high engine loads and avoids thermal dilution under low engine loads. The present work assesses the merit of the aforementioned approach by analysing the generator output during driving cycles simulated with an energy model of a light vehicle. For the baseline evaporator and condenser configuration, the driving cycle averaged electrical power outputs were approximately 320 W and 550 W for the type-approval Worldwide harmonized light vehicles test procedure Class 3 driving cycle and for a real-world highway driving cycle, respectively.

  15. Health Sector Reform, Emotional Exhaustion, and Nursing Burnout: A Retrospective Panel Study in Iran.

    Science.gov (United States)

    Sadati, Ahmad Kalateh; Rahnavard, Farnaz; Heydari, Seyed Taghi; Hemmati, Soroor; Ebrahimzadeh, Najmeh; Lankarani, Kamran Bagheri

    2017-10-01

    Nursing burnout is affected by various factors, including work overload. Since the inauguration of the Health Sector Evolution Plan (HSEP) in Iran in 2014, government hospitals have been required to provide health services to the public at all levels. This decision, however, has increased the volume of patients admitted to government hospitals. Because nurses are on the front line of health services, they are faced with a greater load of care provision. This study aimed to evaluate nursing burnout before and after HSEP in Iran, with an emphasis on the differences between government and private hospitals. This retrospective panel study used Maslach's burnout inventory to evaluate nursing burnout in 371 nurses working in government and private hospitals in Shiraz, Iran, before and 7 months after the health sector reform. Chi-square test and paired t test were used to compare burnout scores. The results showed that nursing burnout had changed significantly after HSEP was launched (p = .030). A more detailed assessment found that burnout and emotional exhaustion had both increased significantly in the government-hospital group (ps = .014 and .001, respectively). However, no significant change in burnout was found in the private-hospital group over the same period. The findings of this study indicate an increase in nursing burnout in government hospitals. An important issue in every health sector reform is nursing resource management, with a focus on burnout. Accordingly, policymakers should consider the work overload situation of nurses and work to prevent increased burnout, especially emotional exhaustion.

  16. Global analyses of evolutionary dynamics and exhaustive search for social norms that maintain cooperation by reputation.

    Science.gov (United States)

    Ohtsuki, Hisashi; Iwasa, Yoh

    2007-02-07

    Reputation formation is a key to understanding indirect reciprocity. In particular, the way to assign reputation to each individual, namely a norm that describes who is good and who is bad, greatly affects the possibility of sustained cooperation in the population. Previously, we have exhaustively studied reputation dynamics that are able to maintain a high level of cooperation at the ESS. However, this analysis examined the stability of monomorphic population and did not investigate polymorphic population where several strategies coexist. Here, we study the evolutionary dynamics of multiple behavioral strategies by replicator dynamics. We exhaustively study all 16 possible norms under which the reputation of a player in the next round is determined by the action of the self and the reputation of the opponent. For each norm, we explore evolutionary dynamics of three strategies: unconditional cooperators, unconditional defectors, and conditional cooperators. We find that only three norms, simple-standing, Kandori, and shunning, can make conditional cooperation evolutionarily stable, hence, realize sustained cooperation. The other 13 norms, including scoring, ultimately lead to the invasion by defectors. Also, we study the model in which private reputation errors exist to a small extent. In this case, we find the stable coexistence of unconditional and conditional cooperators under the three norms.

  17. Emotional exhaustion and cognitive performance in apparently healthy teachers: a longitudinal multi-source study.

    Science.gov (United States)

    Feuerhahn, Nicolas; Stamov-Roßnagel, Christian; Wolfram, Maren; Bellingrath, Silja; Kudielka, Brigitte M

    2013-10-01

    We investigate how emotional exhaustion (EE), the core component of burnout, relates to cognitive performance, job performance and health. Cognitive performance was assessed by self-rated cognitive stress symptoms, self-rated and peer-rated cognitive impairments in everyday tasks and a neuropsychological test of learning and memory (LGT-3); job performance and physical health were gauged by self-reports. Cross-sectional linear regression analyses in a sample of 100 teachers confirm that EE is negatively related to cognitive performance as assessed by self-rating and peer-rating as well as neuropsychological testing (all p Longitudinal linear regression analyses confirm similar trends (p longitudinal analyses, EE also significantly predicts physical health. Contrary to our expectations, EE does not affect job performance. When reversed causation is tested, none of the outcome variables at Time 1 predict EE at Time 2. This speaks against cognitive dysfunctioning serving as a vulnerability factor for exhaustion. In sum, results underpin the negative consequences of EE for cognitive performance and health, which are relevant for individuals and organizations alike. In this way, findings might contribute to the understanding of the burnout syndrome. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Physiological, biochemical and defense system responses of parthenium hysterophorus to vehicular exhaust pollution

    International Nuclear Information System (INIS)

    Khalid, N.; Hussain, M.; Hameed, M.; Ahmad, R.

    2017-01-01

    Pollution caused by vehicular exhaust emissions detrimentally affect plants and other living beings. This investigation was carried out to evaluate the effects of vehicular exhaust pollutants on Parthenium hysterophorus at various sites along two major roads [Pindi Bhattian to Lillah (M-2) and Faisalabad to Sargodha (FSR)]in the Punjab, Pakistan. Control samples of P. hysterophorus were also collected from 100m away from the roads. Chlorophyll contents, photosynthetic rate, transpiration rate, stomatal conductance, substomatal CO/sub 2/ concentration, water use efficiency, total free amino acids and total antioxidant activity of P. hysterophorus were measured. The results depicted significant reductions in chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents of P. hysterophorus. Likewise, reduction in stomatal conductance was also recorded which resulted in lowered photosynthetic and transpiration rates. The overall reduction in photosynthetic rate of P. hysterophorus was 30.92% and 35.38% along M-2 and FSR roads, respectively. The limited photosynthesis resulted in increased levels of sub stomatal /sub 2/ concentration and water use efficiency. The elevated levels of free amino acids and total antioxidant activity were noted and could be attributed to activation of plant's defense system to cope with the deleterious effects of vehicular air pollutants. The significant correlations between various attributes of P. hysterophorus with traffic density signifies the stress caused by vehicular emissions. (author)

  19. Comment on the Nanoparticle Conclusions in Crüts et al. (2008, "Exposure to diesel exhaust induces changes in EEG in human volunteers"

    Directory of Open Access Journals (Sweden)

    Long Christopher M

    2008-07-01

    Full Text Available Abstract A recent publication in this journal reported interesting changes in electroencephalographic (EEG waves that occurred in 10 young, male volunteers following inhalation for one hour of elevated levels of diesel-engine exhaust fumes 1. The authors then proposed a chain of causal events that they hypothesized underlay their observed EEG changes. Their reasoning linked the observed results to nanoparticles in diesel-engine exhaust (DEE, and went on to suggest that associations between changes in ambient particulate matter (PM levels and changes in health statistics might be due to the effects of diesel-engine exhaust (DEE nanoparticles on EEG. We suggest that the extrapolations of the Crüts et al. EEG findings to casual mechanisms about how ambient levels of DEE particulate might affect electrical signals in the brain, and subsequently to how DEE particulate might alter disease risk, are premature.

  20. Analysis of the effects of meteorology on aircraft exhaust dispersion and deposition using a Lagrangian particle model.

    Science.gov (United States)

    Pecorari, Eliana; Mantovani, Alice; Franceschini, Chiara; Bassano, Davide; Palmeri, Luca; Rampazzo, Giancarlo

    2016-01-15

    The risk of air quality degradation is of considerable concern particularly for those airports that are located near urban areas. The ability to quantitatively predict the effects of air pollutants originated by airport operations is important for assessing air quality and the related impacts on human health. Current emission regulations have focused on local air quality in the proximity of airports. However, an integrated study should consider the effects of meteorological events, at both regional and local level, that can affect the dispersion and the deposition of exhausts. Rigorous scientific studies and extensive experimental data could contribute to the analysis of the impacts of airports expansion plans. This paper is focused on the analysis of the effects of meteorology on aircraft emission for the Marco Polo Airport in Venice. This is the most important international airport in the eastern part of the Po' Valley, one of the most polluted area in Europe. Air pollution is exacerbated by meteorology that is a combination of large and local scale effects that do not allow significant dispersion. Moreover, the airport is located near Venice, a city of noteworthy cultural and architectural relevance, and nearby the lagoon that hosts several areas of outstanding ecological importance at European level (Natura 2000 sites). Dispersion and deposit of the main aircraft exhausts (NOx, HC and CO) have been evaluated by using a Lagrangian particle model. Spatial and temporal aircraft exhaust dispersion has been analyzed for LTO cycle. Aircraft taxiing resulted to be the most impacting aircraft operation especially for the airport working area and its surroundings, however occasionally peaks may be observed even at high altitudes when cruise mode starts. Mixing height can affect concentrations more significantly than the concentrations in the exhausts themselves. An increase of HC and CO concentrations (15-50%) has been observed during specific meteorological events

  1. 40 CFR 205.171-2 - Test exhaust system sample selection and preparation.

    Science.gov (United States)

    2010-07-01

    ... Systems § 205.171-2 Test exhaust system sample selection and preparation. (a)(1) Exhaust systems... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test exhaust system sample selection and preparation. 205.171-2 Section 205.171-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  2. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.; Keller, G.M.

    1997-01-01

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  3. 40 CFR 90.414 - Raw gaseous exhaust sampling and analytical system description.

    Science.gov (United States)

    2010-07-01

    ... probe may not be greater than 0.10 cm. The fitting that attaches the probe to the exhaust pipe must be... the different analyzers. (2) Heat the sample transport system from the engine exhaust pipe to the HC... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Raw gaseous exhaust sampling and...

  4. 40 CFR 89.412 - Raw gaseous exhaust sampling and analytical system description.

    Science.gov (United States)

    2010-07-01

    ... the exhaust pipe shall be as small as practical in order to minimize heat loss from the probe. (2) The... sample transport system from the engine exhaust pipe to the HC analyzer and the NOX analyzer must be... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Raw gaseous exhaust sampling and...

  5. 40 CFR 91.414 - Raw gaseous exhaust sampling and analytical system description.

    Science.gov (United States)

    2010-07-01

    ... shall not be greater than 0.10 cm. The fitting that attaches the probe to the exhaust pipe shall be as... internally to the different analyzers. (2) Heat the sample transport system from the engine exhaust pipe to... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Raw gaseous exhaust sampling and...

  6. Current sheets and pressure anisotropy in the reconnection exhaust

    International Nuclear Information System (INIS)

    Le, A.; Karimabadi, H.; Roytershteyn, V.; Egedal, J.; Ng, J.; Scudder, J.; Daughton, W.; Liu, Y.-H.

    2014-01-01

    A particle-in-cell simulation shows that the exhaust during anti-parallel reconnection in the collisionless regime contains a current sheet extending 100 inertial lengths from the X line. The current sheet is supported by electron pressure anisotropy near the X line and ion anisotropy farther downstream. Field-aligned electron currents flowing outside the magnetic separatrices feed the exhaust current sheet and generate the out-of-plane, or Hall, magnetic field. Existing models based on different mechanisms for each particle species provide good estimates for the levels of pressure anisotropy. The ion anisotropy, which is strong enough to reach the firehose instability threshold, is also important for overall force balance. It reduces the outflow speed of the plasma

  7. Current sheets and pressure anisotropy in the reconnection exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Le, A.; Karimabadi, H.; Roytershteyn, V. [SciberQuest, Inc., Del Mar, California 92014 (United States); Egedal, J. [University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States); Ng, J. [PPPL, Princeton University, Princeton, New Jersey 08543 (United States); Scudder, J. [University of Iowa, Iowa City, Iowa 52242 (United States); Daughton, W.; Liu, Y.-H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-01-15

    A particle-in-cell simulation shows that the exhaust during anti-parallel reconnection in the collisionless regime contains a current sheet extending 100 inertial lengths from the X line. The current sheet is supported by electron pressure anisotropy near the X line and ion anisotropy farther downstream. Field-aligned electron currents flowing outside the magnetic separatrices feed the exhaust current sheet and generate the out-of-plane, or Hall, magnetic field. Existing models based on different mechanisms for each particle species provide good estimates for the levels of pressure anisotropy. The ion anisotropy, which is strong enough to reach the firehose instability threshold, is also important for overall force balance. It reduces the outflow speed of the plasma.

  8. ATR prohibits replication catastrophe by preventing global exhaustion of RPA.

    Science.gov (United States)

    Toledo, Luis Ignacio; Altmeyer, Matthias; Rask, Maj-Britt; Lukas, Claudia; Larsen, Dorthe Helena; Povlsen, Lou Klitgaard; Bekker-Jensen, Simon; Mailand, Niels; Bartek, Jiri; Lukas, Jiri

    2013-11-21

    ATR, activated by replication stress, protects replication forks locally and suppresses origin firing globally. Here, we show that these functions of ATR are mechanistically coupled. Although initially stable, stalled forks in ATR-deficient cells undergo nucleus-wide breakage after unscheduled origin firing generates an excess of single-stranded DNA that exhausts the nuclear pool of RPA. Partial reduction of RPA accelerated fork breakage, and forced elevation of RPA was sufficient to delay such "replication catastrophe" even in the absence of ATR activity. Conversely, unscheduled origin firing induced breakage of stalled forks even in cells with active ATR. Thus, ATR-mediated suppression of dormant origins shields active forks against irreversible breakage via preventing exhaustion of nuclear RPA. This study elucidates how replicating genomes avoid destabilizing DNA damage. Because cancer cells commonly feature intrinsically high replication stress, this study also provides a molecular rationale for their hypersensitivity to ATR inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Animals afflicted with lead poisoning from motor exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Scheel-Thomsen, A

    1956-01-01

    Three cases of dogs treated for ulcerous conditions of the oral cavity and a trembling of the limbs, which were eventually discovered to be lead poisoning derived from constant exposure to gasoline and automotive exhaust, are reported. The first case, typical of all three, was first treated in April 1951. The lesions healed after a stay in the hospital but recurred after he returned home. The dog was also asymptomatic when at the owner's summer home for any length of time. It was discovered that at his winter home the dog spent much of his time around a large automobile garage. After treatment with Antoxol (dimercaprol) and benzyl benzoate, he recovered and had no more symptoms of lead poisoning until his death from cancer several years later. Each of the three involved an animal whose daily activities exposed him to the continual presence of gasolines and exhaust fumes containing tetraethyl lead.

  10. Development of alternative ship propulsion in terms of exhaust emissions

    Directory of Open Access Journals (Sweden)

    Markowski Jarosław

    2016-01-01

    Full Text Available The introduction of new emission limits for exhaust emissions of ship engines contributes to the development of new powertrain solutions. New solutions in the simplest approach concern the reduction of the concentration of sulfur in motor fuels. Typically, the aforementioned fuels have a lower value of viscosity which causes a number of supply system problems. It is becoming more and more common to use fuel cells in engine rooms of various types of marine vessels. Unlike conventional systems that use internal combustion engines, these systems have zero exhaust emissions. Hydrogen, methanol, methane and other substances may be used as a fuel in fuel cells. However, so far the best operating parameters are manifested by cells powered by hydrogen, which is associated with difficulties in obtaining and storing this fuel. Therefore, the use of turbine engines allows the obtaining of large operating and environmental advantages. The paper presents a comparison of the ecological parameters of turbine and piston engines.

  11. Particle collector scoops for improved exhaust in ''axisymmetric'' devices

    International Nuclear Information System (INIS)

    Conn, R.W.; Wolf, G.H.

    1987-11-01

    Application of particle collector scoops in front of the pumping ducts of axisymmetric divertor/magnetic limiter configurations is proposed. These scoops should enclose a significant fraction of the recycling particles. The resulting increase in natural particle pressure in front of the pumping ducts leads to an improved exhaust efficiency. This can permit an extension of the operational margin for density control. Alternatively, aiming at a prescribed exhaust flow in reactor-type devices such as INTOR, the pumping ducts could be reduced in aperture, leaving valuable space for other components. The lay-out of the proposed scheme depends on the heat load on the leading edge in front of the scoop and on the deflector in front of the pumping ducts. 14 refs., 5 figs

  12. High exhaust temperature, zoned, electrically-heated particulate matter filter

    Science.gov (United States)

    Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima

    2015-09-22

    A system includes a particulate matter (PM) filter, an electric heater, and a control circuit. The electric heater includes multiple zones, which each correspond to longitudinal zones along a length of the PM filter. A first zone includes multiple discontinuous sub-zones. The control circuit determines whether regeneration is needed based on an estimated level of loading of the PM filter and an exhaust flow rate. In response to a determination that regeneration is needed, the control circuit: controls an operating parameter of an engine to increase an exhaust temperature to a first temperature during a first period; after the first period, activates the first zone; deactivates the first zone in response to a minimum filter face temperature being reached; subsequent to deactivating the first zone, activates a second zone; and deactivates the second zone in response to the minimum filter face temperature being reached.

  13. PIXE analysis of exhaust gas from diesel engine

    International Nuclear Information System (INIS)

    Miyake, Hirosi; Michijima, Masami; Onishi, Masayuki; Fujitani, Tatsuya.

    1986-01-01

    The variation of elemental concentrations in exhaust gas of a Diesel engine with the outputs was studied. Particulates in high temperature gas were collected on silica fiber filters and analyzed by PIXE method. Concentrations of S and V were nearly proportional to particulate masses and fuel consumption rates per discharging rates of exhaust gas respectively. While, concentrations of Fe and Mn were markedly increased together with engine outputs, and Mn/Fe ratios were nearly equal to those of the material of piston rings and the cylinder liner. Concentrations of the elements contained in lubricant, such as Ca and Mo, were also conspicuously increased with the outputs. It was shown that PIXE analysis is a useful tool for engine diagonostics owing to its high sensitive multi-elemental availability without chemical treatments. (author)

  14. Design and Optimisation of Electrostatic Precipitator for Diesel Exhaust

    Science.gov (United States)

    Srinivaas, A.; Sathian, Samanyu; Ramesh, Arjun

    2018-02-01

    The principle of an industrially used emission reduction technique is employed in automotive diesel exhaust to reduce the diesel particulate emission. As the Emission regulation are becoming more stringent legislations have been formulated, due to the hazardous increase in the air quality index in major cities. Initially electrostatic precipitation principle and working was investigated. The High voltage requirement in an Electrostatic precipitator is obtained by designing an appropriate circuit in MATLAB -SIMULINK. Mechanical structural design of the new model after treatment device for the specific diesel exhaust was done. Fluid flow analysis of the ESP model was carried out using ANSYS CFX for optimized fluid with a reduced back pressure. Design reconsideration was done in accordance with fluid flow analysis. Accordingly, a new design is developed by considering diesel particulate filter and catalytic converter design to ESP model.

  15. Divertor particle exhaust and wall inventory on DIII-D

    International Nuclear Information System (INIS)

    Maingi, R.; Jackson, G.L.; Mahdavi, M.A.; Schaffer, M.J.; Wade, M.R.; Mioduszewski, P.K.; Hogan, J.T.; Klepper, C.C.; Haas, G.

    1995-01-01

    Many tokamaks achieve optimum plasma performance by achieving low recycling; various wall conditioning techniques including helium glow discharge cleaning (HeGDC) are routinely applied to help achieve low recycling. Many of these techniques allow strong, transient wall pumping, but they may not be effective for long-pulse tokamaks, such as the International Thermonuclear Experimental Reactor (ITER), the Tokamak Physics Experiment (TPX), Tore Supra Continu, and JT-60SU. Continuous particle exhaust using an in-situ pumping scheme may be effective for wall inventory control in such devices. Recent particle balance experiments on the Tore Supra and DIII-D tokamaks demonstrated that the wall particle inventory could be reduced during a given discharge by use of continuous particle exhaust. In this paper the authors report the first results of wall inventory control and good performance with the in-situ DIII-D cryopump, replacing the HeGDC normally applied between discharges

  16. Mixed graphite cast iron for automotive exhaust component applications

    OpenAIRE

    De-lin Li

    2017-01-01

    Both spheroidal graphite iron and compacted graphite iron are used in the automotive industry. A recently proposed mixed graphite iron exhibits a microstructure between the conventional spheroidal graphite iron and compacted graphite iron. Evaluation results clearly indicate the suitability and benefits of mixed graphite iron for exhaust component applications with respect to casting, machining, mechanical, thermophysical, oxidation, and thermal fatigue properties. A new ASTM standard speci...

  17. Diesel emission reduction using internal exhaust gas recirculation

    Science.gov (United States)

    He, Xin [Denver, CO; Durrett, Russell P [Bloomfield Hills, MI

    2012-01-24

    A method for controlling combustion in a direct-injection diesel engine includes monitoring a crankshaft rotational position of a cylinder of the engine, monitoring an engine load, determining an intake stroke within the cylinder based upon the crankshaft rotational position, and when the engine load is less than a threshold engine load, opening an exhaust valve for the cylinder during a portion of the intake stroke.

  18. Reducing drag of a commuter train, using engine exhaust momentum

    Science.gov (United States)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  19. Experimental exposure to diesel exhaust increases arterial stiffness in man

    Directory of Open Access Journals (Sweden)

    Newby David E

    2009-03-01

    Full Text Available Abstract Introduction Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. Methods In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 μg/m3 or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA, as well as at the femoral and carotid arteries for pulse wave velocity (PWV. PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP, augmentation index (AIx and time to wave reflection (Tr were calculated. Results Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02 and in AIx of 7.8% (p = 0.01, along with a 16 ms reduction in Tr (p = 0.03, 10 minutes post-exposure. Conclusion Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution.

  20. Health effects of subchronic inhalation exposure to gasoline engine exhaust.

    Science.gov (United States)

    Reed, M D; Barrett, E G; Campen, M J; Divine, K K; Gigliotti, A P; McDonald, J D; Seagrave, J C; Mauderly, J L; Seilkop, S K; Swenberg, J A

    2008-10-01

    Gasoline engine emissions are a ubiquitous source of exposure to complex mixtures of particulate matter (PM) and non-PM pollutants; yet their health hazards have received little study in comparison with those of diesel emissions. As a component of the National Environmental Respiratory Center (NERC) multipollutant research program, F344 and SHR rats and A/J, C57BL/6, and BALBc mice were exposed 6 h/day, 7 days/week for 1 week to 6 months to exhaust from 1996 General Motors 4.3-L engines burning national average fuel on a simulated urban operating cycle. Exposure groups included whole exhaust diluted 1:10, 1:15, or 1:90, filtered exhaust at the 1:10 dilution, or clean air controls. Evaluations included organ weight, histopathology, hematology, serum chemistry, bronchoalveolar lavage, cardiac electrophysiology, micronuclei in circulating cells, DNA methylation and oxidative injury, clearance of Pseudomonas aeruginosa from the lung, and development of respiratory allergic responses to ovalbumin. Among the 120 outcome variables, only 20 demonstrated significant exposure effects. Several statistically significant effects appeared isolated and were not supported by related variables. The most coherent and consistent effects were those related to increased red blood cells, interpreted as likely to have resulted from exposure to 13-107 ppm carbon monoxide. Other effects supported by multiple variables included mild lung irritation and depression of oxidant production by alveolar macrophages. The lowest exposure level caused no significant effects. Because only 6 of the 20 significant effects appeared to be substantially reversed by PM filtration, the majority of effects were apparently caused by non-PM components of exhaust.

  1. Gravimetric Measurements of Filtering Facepiece Respirators Challenged With Diesel Exhaust.

    Science.gov (United States)

    Satish, Swathi; Swanson, Jacob J; Xiao, Kai; Viner, Andrew S; Kittelson, David B; Pui, David Y H

    2017-07-01

    Elevated concentrations of diesel exhaust have been linked to adverse health effects. Filtering facepiece respirators (FFRs) are widely used as a form of respiratory protection against diesel particulate matter (DPM) in occupational settings. Previous results (Penconek A, Drążyk P, Moskal A. (2013) Penetration of diesel exhaust particles through commercially available dust half masks. Ann Occup Hyg; 57: 360-73.) have suggested that common FFRs are less efficient than would be expected for this purpose based on their certification approvals. The objective of this study was to measure the penetration of DPM through NIOSH-certified R95 and P95 electret respirators to verify this result. Gravimetric-based penetration measurements conducted using polytetrafluoroethylene (PTFE) and polypropylene (PP) filters were compared with penetration measurements made with a Scanning Mobility Particle Sizer (SMPS, TSI Inc.), which measures the particle size distribution. Gravimetric measurements using PP filters were variable compared to SMPS measurements and biased high due to adsorption of gas phase organic material. Relatively inert PTFE filters adsorbed less gas phase organic material resulting in measurements that were more accurate. To attempt to correct for artifacts associated with adsorption of gas phase organic material, primary and secondary filters were used in series upstream and downstream of the FFR. Correcting for adsorption by subtracting the secondary mass from the primary mass improved the result for both PTFE and PP filters but this correction is subject to 'equilibrium' conditions that depend on sampling time and the concentration of particles and gas phase hydrocarbons. Overall, the results demonstrate that the use of filters to determine filtration efficiency of FFRs challenged with diesel exhaust produces erroneous results due to the presence of gas phase hydrocarbons in diesel exhaust and the tendency of filters to adsorb organic material. Published by

  2. Heat-pipe assisted thermoelectric generators for exhaust gas applications

    OpenAIRE

    Gonçalves, L. M.; Martins, Jorge; Antunes, Joaquim; Rocha, Romeu; Brito, F. P.

    2012-01-01

    Millions of hybrid cars are already running on our roads with the purpose of reducing fossil fuel dependence. One of their main advantages is the recovery of wasted energy, namely by brake recovery. However, there are other sources of wasted energy in a car powered by an internal combustion engine, such as the heat lost through the cooling system, lubrication system (oil coolers) and in the exhaust system. These energies can be recuperated by the use of thermoelectric generators (TEG) based o...

  3. 40 CFR 86.1544 - Calculation; idle exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... the dilute wet-basis CO to dilute dry-basis values. An assumption that the percent of water by volume in the sample bag is 2 percent is acceptable. For example: Dilute dry CO=(dilute wet CO)/(1.00-0.02) (6) Calculate the raw dry-basis CO values by: Raw dry CO=(DF) (dilute dry CO) (c) If the raw exhaust...

  4. Performance and exhaust emissions of a biodiesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Canakci, Mustafa [Kocaeli University, Technical Education Faculty, 41380 Kocaeli (Turkey); Erdil, Ahmet [Kocaeli University, Engineering Faculty, 41040 Kocaeli (Turkey); Arcaklioglu, Erol [Kirikkale University, Engineering Faculty, 71450 Kirikkale (Turkey)

    2006-06-15

    In this study, the applicabilities of Artificial Neural Networks (ANNs) have been investigated for the performance and exhaust-emission values of a diesel engine fueled with biodiesels from different feedstocks and petroleum diesel fuels. The engine performance and emissions characteristics of two different petroleum diesel-fuels (No. 1 and No. 2), biodiesels (from soybean oil and yellow grease), and their 20% blends with No. 2 diesel fuel were used as experimental results. The fuels were tested at full load (100%) at 1400-rpm engine speed, where the engine torque was 257.6Nm. To train the network, the average molecular weight, net heat of combustion, specific gravity, kinematic viscosity, C/H ratio and cetane number of each fuel are used as the input layer, while outputs are the brake specific fuel-consumption, exhaust temperature, and exhaust emissions. The back-propagation learning algorithm with three different variants, single layer, and logistic sigmoid transfer function were used in the network. By using weights in the network, formulations have been given for each output. The network has yielded R{sup 2} values of 0.99 and the mean % errors are smaller than 4.2 for the training data, while the R{sup 2} values are about 0.99 and the mean % errors are smaller than 5.5 for the test data. The performance and exhaust emissions from a diesel engine, using biodiesel blends with No. 2 diesel fuel up to 20%, have been predicted using the ANN model. sing the ANN model. (author)

  5. Adsorbent cartridge for the exhaust of diazo process machines

    International Nuclear Information System (INIS)

    Michlin, N.; Thies, E.J.

    1982-01-01

    A disposable cartridge filled with a chemical composition that acts as an adsorbent for ammonia vapor is adapted to be used in connection with a diazo process printing machine having a vacuum exhausted chamber. Exhaust from the chamber is passed through the cartridge to remove the noxious ammonia vapors and then is vented into the atmosphere. The cartridge is housed in an elongated rectangular cardboard box having three end flaps formed at each of its opposed open ends. Two opposed flaps of each set are formed with central holes and a plastic screen section adhered between these flaps to retain and allow access to the center section of the box which contains the adsorbent chemical. The center end flaps have knock-outs or tear strips that allow holes to be formed in their centers. These center end flaps cover the screens during shipment and when the cartridge is ready for use the center sections of these end flaps are knocked-out to allow the machine exhaust to be vented into and out of the cartridge

  6. Thermal analysis on x-ray tube for exhaust process

    Science.gov (United States)

    Kumar, Rakesh; Rao Ratnala, Srinivas; Veeresh Kumar, G. B.; Shivakumar Gouda, P. S.

    2018-02-01

    It is great importance in the use of X-rays for medical purposes that the dose given to both the patient and the operator is carefully controlled. There are many types of the X- ray tubes used for different applications based on their capacity and power supplied. In present thesis maxi ray 165 tube is analysed for thermal exhaust processes with ±5% accuracy. Exhaust process is usually done to remove all the air particles and to degasify the insert under high vacuum at 2e-05Torr. The tube glass is made up of Pyrex material, 95%Tungsten and 5%rhenium is used as target material for which the melting point temperature is 3350°C. Various materials are used for various parts; during the operation of X- ray tube these waste gases are released due to high temperature which in turn disturbs the flow of electrons. Thus, before using the X-ray tube for practical applications it has to undergo exhaust processes. Initially we build MX 165 model to carry out thermal analysis, and then we simulate the bearing temperature profiles with FE model to match with test results with ±5%accuracy. At last implement the critical protocols required for manufacturing processes like MF Heating, E-beam, Seasoning and FT.

  7. Chemical processes in the turbine and exhaust nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Lukachko, S P; Waitz, I A [Massachusetts Inst. of Tech., Cambridge, MA (United States). Aero-Environmental Lab.; Miake-Lye, R C; Brown, R C; Anderson, M R [Aerodyne Research, Inc., Billerica, MA (United States); Dawes, W N [University Engineering Dept., Cambridge (United Kingdom). Whittle Lab.

    1998-12-31

    The objective is to establish an understanding of primary pollutant, trace species, and aerosol chemical evolution as engine exhaust travels through the nonuniform, unsteady flow fields of the turbine and exhaust nozzle. An understanding of such processes is necessary to provide accurate inputs for plume-wake modeling efforts and is therefore a critical element in an assessment of the atmospheric effects of both current and future aircraft. To perform these studies, a numerical tool was developed combining the calculation of chemical kinetics and one-, two-, or three-dimensional (1-D, 2-D, 3-D) Reynolds-averaged flow equations. Using a chemistry model that includes HO{sub x}, NO{sub y}, SO{sub x}, and CO{sub x} reactions, several 1-D parametric analyses were conducted for the entire turbine and exhaust nozzle flow path of a typical advanced subsonic engine to understand the effects of various flow and chemistry uncertainties on a baseline 1-D result. These calculations were also used to determine parametric criteria for judging 1-D, 2-D, and 3-D modeling requirements as well as to provide information about chemical speciation at the nozzle exit plane. (author) 9 refs.

  8. Basement depressurization using dwelling mechanical exhaust ventilation system

    International Nuclear Information System (INIS)

    Collignan, B.; O'Kelly, P.; Pilch, E.

    2004-01-01

    The mechanical ventilation exhaust system is commonly used in France to generate air renewal into building and especially into dwelling. It consists of a permanent mechanical air extraction from technical rooms (kitchen, bathrooms and toilets) using a unique fan connected to exhaust ducts. Natural air inlets in living room and bed rooms ensure an air flow from living spaces towards technical rooms. To fight against radon into building, the most recognised efficient technique is the Soil Depressurization System (S.D.S.) consisting in depressurizing the house basement. The aim of this study is to test the ability of the dwelling mechanical ventilation system to depressurize the basement in conjunction with air renewal of a house. For that purpose, a S.D.S. has been installed in an experimental house at CSTB during its construction. At first, tests undertaken with a variable velocity fan connected to the S.D.S. have characterised the permeability of the basement. It is shown that basement can be depressurized adequately with a relatively low air flow rate. At a second stage, S.D.S. has been connected to the exhaust ventilation fan used for the mechanical ventilation of the house. Results obtained show the ability of such ventilation system to generate sufficient depressurization in the basement and to ensure simultaneously adequate air change rate in the dwelling. (author)

  9. Exhaust emissions from an indirect injection dual-fuel engine

    International Nuclear Information System (INIS)

    Abd Alla, G.H.; Badr, O.A.; Soliman, H.A.; Abd Rabbo, M.F.

    2000-01-01

    Diesel engines operating on gaseous fuels are commonly known as dual-fuel engines. In the present work, a single-cylinder, compression ignition, indirect injection research (Ricardo E6) engine has been installed at United Arab Emirates University for investigation of the exhaust emissions when the engine is operating as a dual-fuel engine. The influence of changes in major operating and design parameters, such as the concentration of gaseous fuel in the cylinder charge, pilot fuel quantity, injection timing and intake temperature, on the production of exhaust emissions was investigated. Diesel fuel was used as the pilot fuel, while methane or propane was used as the main fuel which was inducted in the intake manifold and mixed with the intake air. The experimental investigations showed that the poor emissions at light loads can be improved significantly by increasing the concentration of gaseous fuel (total equivalence ratio), employing a large pilot fuel quantity, advancing the injection timing of the pilot fuel and increasing the intake temperature. It is demonstrated that, in general, any measure that tends to increase the size of the combustion regions within the overly lean cylinder charge will reduce markedly the concentrations of unburned hydrocarbons and carbon monoxide in the exhaust gases. (Author)

  10. Exhaust emissions from an indirect injection dual-fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Abd Alla, G.H.; Badr, O.A.; Soliman, H.A.; Abd Rabbo, M.F. [Zagazig Univ., Dept. of Mechanical Engineering, Cairo (Egypt)

    2000-04-01

    Diesel engines operating on gaseous fuels are commonly known as dual-fuel engines. In the present work, a single-cylinder, compression ignition, indirect injection research (Ricardo E6) engine has been installed at United Arab Emirates University for investigation of the exhaust emissions when the engine is operating as a dual-fuel engine. The influence of changes in major operating and design parameters, such as the concentration of gaseous fuel in the cylinder charge, pilot fuel quantity, injection timing and intake temperature, on the production of exhaust emissions was investigated. Diesel fuel was used as the pilot fuel, while methane or propane was used as the main fuel which was inducted in the intake manifold and mixed with the intake air. The experimental investigations showed that the poor emissions at light loads can be improved significantly by increasing the concentration of gaseous fuel (total equivalence ratio), employing a large pilot fuel quantity, advancing the injection timing of the pilot fuel and increasing the intake temperature. It is demonstrated that, in general, any measure that tends to increase the size of the combustion regions within the overly lean cylinder charge will reduce markedly the concentrations of unburned hydrocarbons and carbon monoxide in the exhaust gases. (Author)

  11. RNs and LPNs: emotional exhaustion and intention to leave.

    Science.gov (United States)

    Havaei, Farinaz; MacPhee, Maura; Dahinten, V Susan

    2016-04-01

    To describe and compare registered nurse (RN) and licensed practical nurse (LPN) emotional exhaustion, intention to leave and reasons for leaving. Different skill mix/care delivery models are being used to address nurse shortages and rising health-care costs. Skill mix may include RNs and LPNs. More LPNs are being employed in areas, such as acute care, that have been previously staffed by all RNs. Little is known about nurse outcomes since the introduction of LPNs to acute care settings. This study was a cross-sectional correlational design. A stratified, random sample of acute care nurses completed surveys via Fluidsurveys. The survey was modelled after the RN4CAST nursing workforce survey. For both groups of nurses higher levels of emotional exhaustion were associated with intention to leave and workload was the most frequent reason cited for intention to leave. More RNs than LPNs cited career advancement as a reason to leave, and more LPNs than RNs identified poor salary as a reason to leave. Emotional exhaustion is linked to intention to leave health care. Nurse managers should address work environment factors associated with turnover intentions, such as professional development opportunities and shared decision-making. © 2015 John Wiley & Sons Ltd.

  12. Particle exhaust studies in Tore Supra with a pump limiter

    International Nuclear Information System (INIS)

    Klepper, C.C.; Haste, G.R.; Horton, L.D.; Mioduszewski, P.K.; Uckan, T.; Bonnel, P.; Bruneau, J.L.; Chatelier, M.; Gil, C.; Grisolia, C.; Loarer, T.; Martin, G.; Pegourie, B.; Rodriguez, L.; Watkins, J.G.

    1990-01-01

    The aim of the Tore Supra pump limiter program is to study particle exhaust with a pump limiter system in long-pulse discharges with continuous pellet fueling and strong auxiliary heating. The pump limiter system consists of six vertical modules, located at the bottom of the machine, and one horizontal module at the outer midplane. The results presented here were obtained with the horizontal module only. This module was equipped with two titanium pumps with a total pumping speed of 100000 L/s. The instrumentation of the limiter included pressure gauges, a residual gas analyzer, Langmuir probes, a spectrometer viewing the neutralizer plate for H α and impurity measurements, and water calorimeters. All diagnostics have been commissioned and are operational. Initial results were obtained in low-density discharges, with no gas puffing during the shot. While only a modest effect on the plasma density was observed, large exhaust fluxes were measured in the pump limiter. The most likely source of this gas was outgassing of the graphite walls. Straightforward particle balance between the plasma efflux and the pump limiter exhaust, as applied in previous pump limiter experiments, did not apply. The core plasma and the edge plasma seemed to be largely decoupled and a multi-layer model is being developed to explain the experimental results. (orig.)

  13. Chemical processes in the turbine and exhaust nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Lukachko, S.P.; Waitz, I.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Aero-Environmental Lab.; Miake-Lye, R.C.; Brown, R.C.; Anderson, M.R. [Aerodyne Research, Inc., Billerica, MA (United States); Dawes, W.N. [University Engineering Dept., Cambridge (United Kingdom). Whittle Lab.

    1997-12-31

    The objective is to establish an understanding of primary pollutant, trace species, and aerosol chemical evolution as engine exhaust travels through the nonuniform, unsteady flow fields of the turbine and exhaust nozzle. An understanding of such processes is necessary to provide accurate inputs for plume-wake modeling efforts and is therefore a critical element in an assessment of the atmospheric effects of both current and future aircraft. To perform these studies, a numerical tool was developed combining the calculation of chemical kinetics and one-, two-, or three-dimensional (1-D, 2-D, 3-D) Reynolds-averaged flow equations. Using a chemistry model that includes HO{sub x}, NO{sub y}, SO{sub x}, and CO{sub x} reactions, several 1-D parametric analyses were conducted for the entire turbine and exhaust nozzle flow path of a typical advanced subsonic engine to understand the effects of various flow and chemistry uncertainties on a baseline 1-D result. These calculations were also used to determine parametric criteria for judging 1-D, 2-D, and 3-D modeling requirements as well as to provide information about chemical speciation at the nozzle exit plane. (author) 9 refs.

  14. Dislocation Starvation and Exhaustion Hardening in Mo-alloy Nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, Claire [University of California, Berkeley & LBNL; Bei, Hongbin [ORNL; Lowry, M. B. [University of California, Berkeley; Oh, Jason [Hysitron, Inc., MN; Asif, S.A. Syed [Hysitron, Inc., MN; Warren, O. [Hysitron, Inc., MN; Shan, Zhiwei [Xi' an Jiaotong University, China & Hysitron, Inc., MN; George, Easo P [ORNL; Minor, Andrew [University of California, Berkeley & LBNL

    2012-01-01

    The evolution of defects in Mo alloy nanofibers with initial dislocation densities ranging from 0 to 1.6 1014 m2 were studied using an in situ push-to-pull device in conjunction with a nanoindenter in a transmission electron microscope. Digital image correlation was used to determine stress and strain in local areas of deformation. When they had no initial dislocations the Mo alloy nanofibers suffered sudden catastrophic elongation following elastic deformation to ultrahigh stresses. At the other extreme fibers with a high dislocation density underwent sustained homogeneous deformation after yielding at much lower stresses. Between these two extremes nanofibers with intermediate dislocation densities demonstrated a clear exhaustion hardening behavior, where the progressive exhaustion of dislocations and dislocation sources increases the stress required to drive plasticity. This is consistent with the idea that mechanical size effects ( smaller is stronger ) are due to the fact that nanostructures usually have fewer defects that can operate at lower stresses. By monitoring the evolution of stress locally we find that exhaustion hardening causes the stress in the nanofibers to surpass the critical stress predicted for self-multiplication, supporting a plasticity mechanism that has been hypothesized to account for the rapid strain softening observed in nanoscale bcc materials at high stresses.

  15. Weight Penalty Incurred in Thermoelectric Recovery of Automobile Exhaust Heat

    Science.gov (United States)

    Rowe, D. M.; Smith, J.; Thomas, G.; Min, G.

    2011-05-01

    Thermoelectric recovery of automobile waste exhaust heat has been identified as having potential for reducing fuel consumption and environmentally unfriendly emissions. Around 35% of combustion energy is discharged as heat through the exhaust system, at temperatures which depend upon the engine's operation and range from 800°C to 900°C at the outlet port to less than 50°C at the tail-pipe. Beneficial reduction in fuel consumption of 5% to 10% is widely quoted in the literature. However, comparison between claims is difficult due to nonuniformity of driving conditions. In this paper the available waste exhaust heat energy produced by a 1.5 L family car when undergoing the new European drive cycle was measured and the potential thermoelectric output estimated. The work required to power the vehicle through the drive cycle was also determined and used to evaluate key parameters. This enabled an estimate to be made of the engine efficiency and additional work required by the engine to meet the load of a thermoelectric generating system. It is concluded that incorporating a thermoelectric generator would attract a penalty of around 12 W/kg. Employing thermoelectric modules fabricated from low-density material such as magnesium silicide would considerably reduce the generator weight penalty.

  16. The transillumination technique as a method for the assessment of spermatogenesis using medicinal plants: the effect of extracts of black maca (Lepidium meyenii) and camu camu (Myrciaria dubia) on stages of the spermatogenic cycle in male rats.

    Science.gov (United States)

    Gonzales, Gustavo F; Vasquez, Vanessa Bertha; Gasco, Manuel

    2013-10-01

    Transillumination technique for assessment of stages of spermatogenic cycle is a useful tool for toxicological studies. This study was designed to determine the effect of two medicinal plants on spermatogenesis in male rats using the transillumination technique. For this, the effect of the combination of a fruit with highest content of ascorbic acid (Myrciaria dubia, camu camu) and extract of black maca (Lepidium meyenii) on seminiferous tubule stages scored by transillumination on intact tubules in adult male rats was assessed. Animals were treated during seven days with vehicle, black maca, camu camu or a mixture of black maca + camu camu and assessed for daily sperm production (DSP), stages of spermatogenic cycle as well as antioxidant activity and levels of flavonoids and polyphenols. Black maca increased stages of spermiation (VII-VIII) and mitosis of germ cells (IX-XI), whereas camu camu increased stages of mitosis (IX-XI) and meiosis (XII). Mixture of maca + camu camu increased stages of spermiation, mitosis and meiosis. All treatments increased DSP (pmaca. In conclusion, M. dubia (camu camu) has potential effects improving spermatogenesis and co-administered with maca increase stages of mitosis, meiosis and spermiation of the spermatogenic cycle as assessed by the transillumination technique. This technique is becoming increasingly a useful tool for assessment spermatogenesis.

  17. Construction and evaluation of a self rating scale for stress-induced exhaustion disorder, the Karolinska Exhaustion Disorder Scale.

    Science.gov (United States)

    Besèr, Aniella; Sorjonen, Kimmo; Wahlberg, Kristina; Peterson, Ulla; Nygren, Ake; Asberg, Marie

    2014-02-01

    Prolonged stress (≥ six months) may cause a condition which has been named exhaustion disorder (ED) with ICD-10 code F43.8. ED is characterised by exhaustion, cognitive problems, poor sleep and reduced tolerance to further stress. ED can cause long term disability and depressive symptoms may develop. The aim was to construct and evaluate a self-rating scale, the Karolinska Exhaustion Disorder Scale (KEDS), for the assessment of ED symptoms. A second aim was to examine the relationship between self-rated symptoms of ED, depression, and anxiety using KEDS and the Hospital Anxiety and Depression Scale (HAD). Items were selected based on their correspondence to criteria for ED as formulated by the Swedish National Board of Health and Welfare (NBHW), with seven response alternatives in a Likert-format. Self-ratings performed by 317 clinically assessed participants were used to analyse the scale's psychometric properties. KEDS consists of nine items with a scale range of 0-54. Receiver operating characteristics analysis demonstrated that a cut-off score of 19 was accompanied by high sensitivity and specificity (each above 95%) in the discrimination between healthy subjects and patients with ED. Reliability was satisfactory and confirmatory factor analysis revealed that ED, depression and anxiety are best regarded as different phenomena. KEDS may be a useful tool in the assessment of symptoms of Exhaustion Disorder in clinical as well as research settings. There is evidence that the symptom clusters of ED, anxiety and depression, respectively, reflect three different underlying dimensions. © 2013 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  18. The isotopic composition of CO in vehicle exhaust

    Science.gov (United States)

    Naus, S.; Röckmann, T.; Popa, M. E.

    2018-03-01

    We investigated the isotopic composition of CO in the exhaust of individual vehicles. Additionally, the CO2 isotopes, and the CO:CO2, CH4:CO2 and H2:CO gas ratios were measured. This was done under idling and revving conditions, and for three vehicles in a full driving cycle on a testbench. The spread in the results, even for a single vehicle, was large: for δ13 C in CO ∼ -60 to 0‰, for δ18 O in CO ∼ +10 to +35‰, and for all gas ratios several orders of magnitude. The results show an increase in the spread of isotopic values for CO compared to previous studies, suggesting that increasing complexity of emission control in vehicles might be reflected in the isotopic composition. When including all samples, we find a weighted mean for the δ13 C and δ18 O in CO of -28.7 ± 0.5‰ and +24.8 ± 0.3‰ respectively. This result is dominated by cold petrol vehicles. Diesel vehicles behaved as a distinct group, with CO enriched in 13C and depleted in 18O, compared to petrol vehicles. For the H2:CO ratio of all vehicles, we found a value of 0.71 ± 0.31 ppb:ppb. The CO:CO2 ratio, with a mean of 19.4 ± 6.8 ppb:ppm, and the CH4:CO2 ratio, with a mean of 0.26 ± 0.05 ppb:ppm, are both higher than recent literature indicates. This is likely because our sampling distribution was biased towards cold vehicles, and therefore towards higher emission situations. The CH4:CO2 ratio was found to behave similarly to the CO:CO2 ratio, suggesting that the processes affecting CO and CH4 are similar. The δ13 C values in CO2 were close to the expected δ13 C in fuel, with no significant difference between petrol and diesel vehicles. The δ18 O values in CO2 for petrol vehicles covered a range of 20-35‰, similar to the δ18 O of CO. The δ18 O values in CO2 for diesel vehicles were close to the δ18 O in atmospheric oxygen. A set of polluted atmospheric samples, taken near a highway and inside parking garages, showed an isotopic signature of CO and a H2:CO ratio that were

  19. A numerical study on the effects of exhaust locations on energy consumption and thermal environment in an office room served by displacement ventilation

    International Nuclear Information System (INIS)

    Ahmed, Ahmed Qasim; Gao, Shian; Kareem, Ali Khaleel

    2016-01-01

    Highlights: • An advanced CFD program was developed and validated successfully. • The relation between the exhaust positions and heat sources was analysed. • Energy saving, thermal comfort and inhaled air quality were studied for 5 cases. • By combining the exhaust with office lamps, a 25% of energy saving was achieved. - Abstract: In an office room, many factors affect the pattern of airflow, thermal comfort, indoor air quality and energy saving. In this study, the effects of the location of exhaust diffusers where the warm and contaminant air is extracted and their relation to room heat sources on thermal comfort and energy saving were investigated numerically for an office served by a displacement ventilation system. The indoor air quality in the breathing level and the inhaled zone were also evaluated. The contaminants were released from window and door frames in order to simulate the contaminants coming from outside. The amount of energy consumption and the indoor thermal environment for various exhaust locations were investigated numerically using the computational fluid dynamics techniques. The results showed that the thermal indoor environment, thermal comfort, quality of indoor air and energy saving were greatly improved by combining the exhaust outlets with some of the room’s heat sources such as ceiling lamps and external walls. In particular, a 25.0% of energy saving was achieved by combining the exhaust diffuser with room’s ceiling lamps. In addition, locating the exhaust diffuser near the heat sources also reduced the cooling coil load by 13.8%. The risk of a large difference in temperature between the head and foot levels, increased particle concentration in the occupied zone, as well as increased energy consumption was also clearly demonstrated when the exhaust and recirculated air outlet (return opening) were combined in one unit in the occupied boundary area that is located at 2 m away from the occupants. Thus, for the optimum energy

  20. Job demands, job resources and safety outcomes: The roles of emotional exhaustion and safety compliance.

    Science.gov (United States)

    Li, Feng; Jiang, Li; Yao, Xiang; Li, YongJuan

    2013-03-01

    The aim of this study was to assess the effectiveness of the job demands-resources (JD-R) model in explaining the relationship of job demands and resources with safety outcomes (i.e., workplace injuries and near-misses). We collected self-reported data from 670 crude oil production workers from three sub-companies of a major oilfield company in China. The results of a structural equation analysis indicated that job demands (psychological and physical demands) and job resources (decision latitude, supervisor support and coworker support) could affect emotional exhaustion and safety compliance, and thus influence the occurrence of injuries and near-misses. The implications of the present findings regarding both the JD-R model and occupational safety research were discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.