Behavioral Mechanism during Human Sperm Chemotaxis: Involvement of Hyperactivation

When mammalian spermatozoa become capacitated they acquire, among other activities, chemotactic responsiveness and the ability to exhibit occasional events of hyperactivated motility—a vigorous motility type with large amplitudes of head displacement. Although a number of roles have been proposed for this type of motility, its function is still obscure. Here we provide evidence suggesting that hyperactivation is part of the chemotactic response. By analyzing tracks of spermatozoa swimming in a spatial chemoattractant gradient we demonstrate that, in such a gradient, the level of hyperactivation events is significantly lower than in proper controls. This suggests that upon sensing an increase in the chemoattractant concentration capacitated cells repress their hyperactivation events and thus maintain their course of swimming toward the chemoattractant. Furthermore, in response to a temporal concentration jump achieved by photorelease of the chemoattractant progesterone from its caged form, the responsive cells exhibited a delayed turn, often accompanied by hyperactivation events or an even more intense response in the form of flagellar arrest. This study suggests that the function of hyperactivation is to cause a rather sharp turn during the chemotactic response of capacitated cells so as to assist them to reorient according to the chemoattractant gradient. On the basis of these results a model for the behavior of spermatozoa responding to a spatial chemoattractant gradient is proposed

Quantification and identification of sperm subpopulations using computer-aided sperm analysis and species-specific cut-off values for swimming speed

Motility is an essential characteristic of all fl agellated spermatozoa and assessment of this parameter is one criterion for most semen or sperm evaluations. Computer-aided sperm analysis (CASA) can be used to measure sperm motility more objectively and accurately than manual methods, provided that analysis techniques are standardized. Previous studies have shown that evaluation of sperm subpopulations is more important than analyzing the total motile sperm population alone. We developed a quantitative method to determine cut-off values for swimming speed to identify three sperm subpopulations. We used the Sperm Class Analyzer ® (SCA) CASA system to assess the total percentage of motile spermatozoa in a sperm preparation as well as the percentages of rapid, medium and slow swimming spermatozoa for six mammalian species. Curvilinear velocity (VCL) cut-off values were adjusted manually for each species to include 80% rapid, 15% medium and 5% slow swimming spermatozoa. Our results indicate that the same VCL intervals cannot be used for all species to classify spermatozoa according to swimming speed. After VCL intervals were adjusted for each species, three unique sperm subpopulations could be identifi ed. The effects of medical treatments on sperm motility become apparent in changes in the distribution of spermatozoa among the three swimming speed classes.Web of Scienc

1963

Trees for a Beautiful Golf Course by Philip Scott (page 1) The Golf Course\u27s Worst Enemy by Charles Amorim and Hal Haskell (2) Message from the President by James f. Gilligan (2) Turf Management Club News (3) Quotes from 1962 Freshman (4) When I consider How my Night is Spent Leonard Mailloux(5) Protection of a Golf Course by Pay Lucas Jr. (6) Safety - The Superintendents\u27 Responsibility by Gerald Peters (7) Picture - Senior Stockbridge Turf Majors (8) Picture - Freshmen Stockbridge Turf Majors (9) Kansas - In the Transition Zone by Carl Beer (10 Seeds by Don Daigle (11) Picture - Dean F. P. Jeffrey, Dr. W.G. Colby and Director J. R. Beattie (12) Picture - Graduates of Winter School for Turf Managers - 1963 (13) The Effect of Last Year\u27s Weather Upon This Year\u27s Incidence of Turf Insects by John C. Schread (A-1) Labor-Management Relations by Mortimer H. Gavin S.J. (A-4) Massachusetts Labor Laws by Andrew C. SInclair (A-7) Golf Course Budget by John Espey (A-10) Golf Course Budgets by Robert St. Thomas (A-12) Purpose & Method of Budgeting by Leon St. Pierre (A-13) The Committee Chairman, His Duties by Charles Connelly (A-16) Long-range vs. Short-range Planning by George Farber (A-18) The Golf Course Superintendent, His Duties by Sherwood Moore (A-20) The Budget by Leo Kowalski (A-25) Public Relations by Leon St. Pierre (A-26) A Study of WIlt by Harry Meusal (A-28) Specifications for a Method of Putting Green Construction by Alexander Radko (A-33) Management of Kentucky Bluegrass & Grass Mixtures for Turf by F.V. Juska (A-38) What\u27s New in Fertilizers by Geoffrey S. Cornish (A-40) Methylene Ureas by Harvey Stangel (A-42) Plastic Coated Fertilizers by Louis I. Hansen (A-44) The Role of Sewage Sludge by James Latham Jr. (A-49) The Role of Ureaforms in the Turf Fertilizer Industry by Robert T. Miller (A-51) Why Low Phosphorus & Higher Potassium by L. J. Sullivan (A-55) Uptake of Potassium by Evangel Bredakis (A-59) Responsibility of Industry & Community in Land Usage & Plantings by Joseph L. Beasley (A-61) Turf & Other Planting Problems by H. Thurston Handley Jr. (A-65) Weeds & Diseases by Dominic Marini (A-67) General Maintenacne & Equipment by Lewis Hodgkinson (A-68) Fertilizer Problems by William J. Bennett (A-70) Lawn Construction & Insect Problems by herbert C. Fordham (A-71

Local text cohesion, reading ability and individual science aspirations: key factors influencing comprehension in science classes

In response to the concern of the need to improve the scientific skills of school children, this study investigated the influence of text design (in terms of text cohesion) and individual differences, with the aim of identifying pathways to improving science education in early secondary school (Key Stage 3). One hundred and four secondary school children (56 females, 48 males), aged 12–13 years took part in the study. To assess the influence of local cohesion (lexical and grammatical links between adjacent sentences) in science texts, we measured students’ comprehension (through multiple choice questions) of science text that was high and low in local cohesion. To explore the role of individual differences, students completed tests to measure general reading ability, general intelligence, facets of conscientiousness, science self-concept and individual, friends and family aspirations in science. Students were more accurate in answering comprehension questions after reading text that was high in cohesion than low in cohesion, suggesting that high local text cohesion improved students’ comprehension of science text. Reading ability predicted increased comprehension for both text designs. Individual aspirations in science accounted for unique variance for comprehension for high cohesion text. Implications for the teaching of secondary school science are discussed

Happy Aged People Are All Alike, While Every Unhappy Aged Person Is Unhappy in Its Own Way

Aging of the world's population represents one of the most remarkable success stories of medicine and of humankind, but it is also a source of various challenges. The aim of the collaborative cross-cultural European study of adult well being (ESAW) is to frame the concept of aging successfully within a causal model that embraces physical health and functional status, cognitive efficacy, material security, social support resources, and life activity. Within the framework of this project, we show here that the degree of heterogeneity among people who view aging in a positive light is significantly lower than the degree of heterogeneity of those who hold a negative perception of aging. We base this conclusion on our analysis of a survey involving 12,478 people aged 50 to 90 from six West European countries. We treat the survey database as a bipartite network in which individual respondents are linked to the actual answers they provide. Taking this perspective allows us to construct a projected network of respondents in which each link indicates a statistically validated similarity of answers profile between the connected respondents, and to identify clusters of individuals independently of demographics. We show that mental and physical well-being are key factors determining a positive perception of aging. We further observe that psychological aspects, like self-esteem and resilience, and the nationality of respondents are relevant aspects to discriminate among participants who indicate positive perception of aging

Tropical summer induces DNA fragmentation in boar spermatozoa: implications for evaluating seasonal infertility

Summer infertility continues to undermine pig productivity, costing the pig industry millions in annual losses. The boar’s inefficient capacity to sweat, non-pendulous scrotum and the extensive use of European breeds in tropical conditions, can make the boar particularly vulnerable to the effects of heat stress; however, the link between summer heat stress and boar sperm DNA damage has not yet been demonstrated. Semen from five Large White boars was collected and evaluated during the early dry, late dry and peak wet seasons to determine the effect of seasonal heat stress on the quality and DNA integrity of boar spermatozoa. DNA damage in spermatozoa during the peak wet was 16-fold greater than during the early dry and nearly 9-fold greater than during the late dry season. Sperm concentration was 1.6-fold lower in the peak wet than early dry whereas no difference was found across several motility parameters as determined by computer-assisted sperm analysis. These results demonstrate that tropical summer (peak wet season) induces DNA damage and reduces concentration without depressing motility in boar spermatozoa, suggesting that traditional methods of evaluating sperm motility may not detect inherently compromised spermatozoa. Boar management strategies (such as antioxidant supplementation) need to be developed to specifically mitigate this problem

Genetic association analysis of N-methyl-d-aspartate receptor subunit gene GRIN2B and clinical response to clozapine

OBJECTIVE: Approximately 30% of patients with schizophrenia fail to respond to antipsychotic therapy and are classified as having treatment-resistant schizophrenia. Clozapine is the most efficacious drug for treatment-resistant schizophrenia and may deliver superior therapeutic effects partly by modulating glutamate neurotransmission. Response to clozapine is highly variable and may depend on genetic factors as indicated by twin studies. We investigated eight polymorphisms in the N-methyl-d-aspartate glutamate receptor subunit gene GRIN2B with response to clozapine. METHODS: GRIN2B variants were genotyped using standard TaqMan procedures in 175 European patients with schizophrenia deemed resistant or intolerant to treatment. Response was assessed using change in Brief Psychiatric Rating Scale scores following six months of clozapine therapy. Categorical and continuous response was assessed using chi-squared test and analysis of covariance, respectively. RESULTS: No associations were observed between the variants and response to clozapine. A-allele carriers of rs1072388 responded marginally better to clozapine therapy than GG-homozygotes; however, the difference was not statistically significant (p = 0.067, uncorrected). CONCLUSIONS: Our findings do not support a role for these GRIN2B variants in altering response to clozapine in our sample. Investigation of additional glutamate variants in clozapine response is warranted. Copyright © 2016 John Wiley & Sons, Ltd

Semen molecular and cellular features: these parameters can reliably predict subsequent ART outcome in a goat model

Currently, the assessment of sperm function in a raw or processed semen sample is not able to reliably predict sperm ability to withstand freezing and thawing procedures and in vivo fertility and/or assisted reproductive biotechnologies (ART) outcome. The aim of the present study was to investigate which parameters among a battery of analyses could predict subsequent spermatozoa in vitro fertilization ability and hence blastocyst output in a goat model. Ejaculates were obtained by artificial vagina from 3 adult goats (Capra hircus) aged 2 years (A, B and C). In order to assess the predictive value of viability, computer assisted sperm analyzer (CASA) motility parameters and ATP intracellular concentration before and after thawing and of DNA integrity after thawing on subsequent embryo output after an in vitro fertility test, a logistic regression analysis was used. Individual differences in semen parameters were evident for semen viability after thawing and DNA integrity. Results of IVF test showed that spermatozoa collected from A and B lead to higher cleavage rates (0 < 0.01) and blastocysts output (p < 0.05) compared with C. Logistic regression analysis model explained a deviance of 72% (p < 0.0001), directly related with the mean percentage of rapid spermatozoa in fresh semen (p < 0.01), semen viability after thawing (p < 0.01), and with two of the three comet parameters considered, i.e tail DNA percentage and comet length (p < 0.0001). DNA integrity alone had a high predictive value on IVF outcome with frozen/thawed semen (deviance explained: 57%). The model proposed here represents one of the many possible ways to explain differences found in embryo output following IVF with different semen donors and may represent a useful tool to select the most suitable donors for semen cryopreservation