Sperm storage in the oviduct of the internal fertilizing frog Ascaphus truei.

Science.gov (United States)

Sever, D M; Moriarty, E C; Rania, L C; Hamlett, W C

2001-04-01

This study provides the first descriptions of sperm storage at the tissue and cellular levels in a female frog or toad. Oviducal anatomy was studied by light and electron microscopy in Ascaphus truei from north coastal California. Ascaphus truei is one of the few species of anurans in which fertilization is internal. Unlike other anurans with internal fertilization, however, mating in A. truei consists of a unique combination of amplectic and copulatory mechanisms that we term "copulexus." Posterior to a short, aglandular infundibular region, the oviduct possesses: 1) a proximal, convoluted ampullary region where intrinsic tubular glands secrete gelatinous envelopes around eggs; 2) a middle ovisac region where fertilization occurs; and 3) a distal oviducal sinus formed by medial junction of the ovisacs. Sperm storage tubules (SSTs) occur in the anterior portions of the ovisacs and consist of simple tubular glands. SSTs and the rest of the oviducal lining stain positively with the periodic acid-Schiff's procedure for neutral carbohydrates and this reaction is especially intense in reproductively active females. Sperm were found in the SSTs of gravid females as well as some nonvitellogenic females. The sperm are in orderly bundles in the SSTs, and although occasionally sperm nuclei were embedded in the epithelium, no evidence for spermiophagy was found. Oviducal sperm storage in A. truei is homoplastic, with closest structural similarities to squamate reptiles. Oviduct/sperm design constraints appear to limit the options for expression of features associated with oviducal sperm storage. Copyright 2001 Wiley-Liss, Inc.

Cyto- and chemoarchitecture of the dorsal thalamus of the monotreme Tachyglossus aculeatus, the short beaked echidna.

Science.gov (United States)

Ashwell, Ken W S; Paxinos, George

2005-12-01

We have examined the cyto- and chemoarchitecture of the dorsal thalamus of the short beaked echidna (Tachyglossus aculeatus), using Nissl and myelin staining, immunoreactivity for parvalbumin, calbindin, calretinin and non-phosphorylated neurofilament protein (SMI-32 antibody), and histochemistry for acetylcholinesterase and NADPH diaphorase. Immunohistochemical methods revealed many nuclear boundaries, which were difficult to discern with Nissl staining. Parvalbumin immunoreactive somata were concentrated in the ventral posterior, reticular, posterior, lateral and medial geniculate nuclei, while parvalbumin immunoreactivity of the neuropil was present throughout all but the midline nuclei. Large numbers of calbindin immunoreactive somata were also found within the midline thalamic nuclei, and thalamic sensory relay nuclei. Immunoreactivity for calretinin was found in many small somata within the lateral geniculate "a" nucleus, with other labelled somata found in the lateral geniculate "b" nucleus, ventral posterior medial and ventral posterior lateral nuclei. Immunoreactivity with the SMI-32 antibody was largely confined to somata and neuropil within the thalamocortical relay nuclei (ventral posterior medial and lateral nuclei, lateral and medial geniculate nuclei and the posterior thalamic nucleus). In broad terms there were many similarities between the thalamus of this monotreme and that of eutheria (e.g. disposition of somatosensory thalamus, complementarity of parvalbumin and calbindin immunoreactive structures), but there were some unique features of the thalamus of the echidna. These include the relatively small size of the thalamic reticular nucleus and the preponderance of calbindin immunoreactive neurons over parvalbumin immunoreactive neurons in the ventral posterior nucleus.

A Dual Wavelength Echidna® Lidar (DWEL) for Forest Structure Retrieval

Science.gov (United States)

Strahler, A. H.; Douglas, E. S.; Martel, J.; Cook, T.; Mendillo, C.; Marshall, R. A.; Chakrabarti, S.; Schaaf, C.; Woodcock, C. E.; Li, Z.; Yang, X.; Culvenor, D.; Jupp, D.; Newnham, G.; Lovell, J.

2012-12-01

A newly-constructed, ground-based lidar scanner designed for automated retrieval of forest structure, the Dual Wavelength Echidna Lidar (DWEL), separates laser "hits" of leaves from hits of trunks and branches using simultaneous laser pulses at 1548 nm, where leaf water content produces strong absorption, and at 1064 nm, where leaves and branches have similar reflectances. The DWEL uses a rotating mirror scan mechanism on a revolving mount, coupled with full digitization of return waveforms, to identify, locate, and parameterize scattering events in the three-dimensional space around the scanner. In the DWEL instrument, the two measurement lasers are triggered simultaneously. Laser pulses are sharply peaked; full-width half-max pulse length of the lasers is 5.1 ns, corresponding to 1.53 m in distance. The laser pulses are expanded and collimated to a 6-mm beam diameter (1/e2), then shaped into a top-hat cross section using a diffraction apparatus. Interchangeable optics provide a beam divergence of 1.25-, 2.5-, or 5-mrad. A mirror and two dichroic filters combine the beams and join them with a visible green continuous-wave marker laser. The combined beam is guided along an optical path to the 10-cm rotating scan mirror. Scan encoders in zenith and azimuth directions resolve the pointing of the instrument to 215 units per 2π radians. Scan resolution has three settings: 1-, 2-, and 4-mrad. Scan time varies with resolution: 11 min at 4 mrad; 41 min at 2 mrad; and 2.7 hr at 1 mrad. The return beam enters the 10-cm diameter Newtonian-Nasmyth telescope and is directed to the receiver assembly, which splits the return beam using a dichroic filter and narrowband pass filters. Two 0.5 mm InGaAs photodiodes measure the return signal, which is sampled by two digitizers at 2 gigasamples per second with 10-bit precision. This provides a 7.5-cm sampling of the 1.53 m pulse, allowing very good reconstruction of the return waveform. The designed signal-to-noise ratio is 10:1 (8

Sperm Production Rate, Gonadal and Extragonadal Sperm ...

African Journals Online (AJOL)

Five healthy West African Dwarf (WAD) rams, 1.5 to 2.5 years of age and weighing between 15 kg to 20 kg were used to determine daily sperm production, gonadal and exragonadal sperm reserves. Gonadal and extragonadal sperm reserves were estimated by the haemocytometric method, while the daily sperm production ...

Sperm morphology in five species of cicadettine cicadas (Hemiptera: Cicadomorpha: Cicadidae).

Science.gov (United States)

Chawanji, Abraham S; Hodgson, Alan N; Villet, Martin H

2006-12-01

Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species.

Individual adjustment of sperm expenditure accords with sperm competition theory.

Science.gov (United States)

Pilastro, Andrea; Scaggiante, Marta; Rasotto, Maria B

2002-07-23

Sperm competition theory predicts that males should strategically allocate their sperm reserves according to the level of sperm competition, defined as the probability that the sperm of two males compete for fertilizing a given set of ova. Substantial evidence from numerous animal taxa suggests that, at the individual level, sperm expenditure increases when the risk of sperm competition is greater. In contrast, according to the "intensity model" of sperm competition [Parker, G. A., Ball, M. A., Stockley, P. & Gage, M. J. G. (1996) Proc. R. Soc. London Ser. B 263, 1291-1297], when more than two ejaculates compete during a given mating event, sperm expenditure should decrease as the number of competing males increases. Empirical evidence supporting this prediction, however, is still lacking. Here we measured sperm expenditure in two gobiid fishes, the grass (Zosterisessor ophiocephalus) and black goby (Gobius niger), in which up to six sneakers can congregate around the nest of territorial males and release their sperm when females spawn. We show that, in accordance with theory, sneaker males of both species release fewer sperm as the number of competitors increases.

Sperm head's birefringence: a new criterion for sperm selection.

Science.gov (United States)

Gianaroli, Luca; Magli, M Cristina; Collodel, Giulia; Moretti, Elena; Ferraretti, Anna P; Baccetti, Baccio

2008-07-01

To investigate the characteristics of birefringence in human sperm heads and apply polarization microscopy for sperm selection at intracytoplasmic sperm injection (ICSI). Prospective randomized study. Reproductive Medicine Unit, Società Italiana Studi Medicina della Riproduzione, Bologna, Italy. A total of 112 male patients had birefringent sperm selected for ICSI (study group). The clinical outcome was compared with that obtained in 119 couples who underwent a conventional ICSI cycle (control group). The proportion of birefringent spermatozoa was evaluated before and after treatment in relation to the sperm sample quality. Embryo development and clinical outcome in the study group were compared with those in the controls. Proportion of birefringent sperm heads, rates of fertilization, cleavage, pregnancy, implantation, and ongoing implantation. The proportion of birefringent spermatozoa was significantly higher in normospermic samples when compared with oligoasthenoteratospermic samples with no progressive motility and testicular sperm extraction samples. Although fertilization and cleavage rates did not differ between the study and control groups, in the most severe male factor condition (oligoasthenoteratospermic with no progressive motility and testicular sperm extraction), the rates of clinical pregnancy, ongoing pregnancy, and implantation were significantly higher in the study group versus the controls. The analysis of birefringence in the sperm head could represent both a diagnostic tool and a novel method for sperm selection.

Sperm competition selects for sperm quantity and quality in the Australian Maluridae.

Science.gov (United States)

Rowe, Melissah; Pruett-Jones, Stephen

2011-01-25

When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm competition and both testes size and the number of sperm available for copulations. Sperm competition is also thought to favor increases in sperm quality and changes in testicular morphology that lead to increased sperm production. However, in contrast to sperm quantity, these hypotheses have received considerably less empirical support and remain somewhat controversial. In a comparative study using the Australian Maluridae (fairy-wrens, emu-wrens, grasswrens), we tested whether increasing levels of sperm competition were associated with increases in both sperm quantity and quality, as well as an increase in the relative amount of seminiferous tubule tissue contained within the testes. After controlling for phylogeny, we found positive associations between sperm competition and sperm numbers, both in sperm reserves and in ejaculate samples. Additionally, as sperm competition level increased, the proportion of testicular spermatogenic tissue also increased, suggesting that sperm competition selects for greater sperm production per unit of testicular tissue. Finally, we also found that sperm competition level was positively associated with multiple sperm quality traits, including the proportion of motile sperm in ejaculates and the proportion of both viable and morphologically normal sperm in sperm reserves. These results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae. Furthermore, our findings emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype.

Hyaluronic acid binding ability of human sperm reflects cellular maturity and fertilizing potential: selection of sperm for intracytoplasmic sperm injection.

Science.gov (United States)

Huszar, Gabor; Ozkavukcu, Sinan; Jakab, Attila; Celik-Ozenci, Ciler; Sati, G Leyla; Cayli, Sevil

2006-06-01

The current concepts of sperm biochemical markers and the central role of the HspA2 chaperone protein, a measure of sperm cellular maturity and fertilizing potential, are reviewed. Because HspA2 is a component of the synaptonemal complex, low HspA2 levels and increased frequency of chromosomal aneuploidies are related in diminished maturity sperm. We also suggest a relationship between HspA2 expression in elongating spermatids and events of late spermiogenesis, such as cytoplasmic extrusion and plasma membrane remodeling that aid the formation of the zona pellucida binding and hyaluronic acid binding sites. The presence of hyaluronic acid receptor on the plasma membrane of mature sperm, coupled with hyaluronic acid coated glass or plastic surfaces, facilitates testing of sperm function and selection of single mature sperm for intracytoplasmic sperm injection. The frequencies of sperm with chromosomal disomy are reduced approximately fourfold to fivefold in hyaluronic acid selected sperm compared with semen sperm, comparable to the increase in such abnormalities in intracytoplasmic sperm injection offspring. Hyaluronic acid binding also excludes immature sperm with cytoplasmic extrusion, persistent histones, and DNA chain breaks. Hyaluronic acid mediated sperm selection is a novel technique that is comparable to sperm zona pellucida binding. Hyaluronic acid selected sperm will also alleviate the risks related to intracytoplasmic sperm injection fertilization with sperm of diminished maturity that currently cause worldwide concern.

Higher order jet prolongations type gauge natural bundles over vector bundles

Directory of Open Access Journals (Sweden)

Jan Kurek

2004-05-01

Full Text Available Let $rgeq 3$ and $mgeq 2$ be natural numbers and $E$ be a vector bundle with $m$-dimensional basis. We find all gauge natural bundles ``similar" to the $r$-jet prolongation bundle $J^rE$ of $E$. We also find all gauge natural bundles ``similar" to the vector $r$-tangent bundle $(J^r_{fl}(E,R_0^*$ of $E$.

Sperm competition and reproductive mode influence sperm dimensions and structure among snakes.

Science.gov (United States)

Tourmente, Maximiliano; Gomendio, Montserrat; Roldan, Eduardo R S; Giojalas, Laura C; Chiaraviglio, Margarita

2009-10-01

The role of sperm competition in increasing sperm length is a controversial issue, because findings from different taxa seem contradictory. We present a comparative study of 25 species of snakes with different levels of sperm competition to test whether it influences the size and structure of different sperm components. We show that, as levels of sperm competition increase, so does sperm length, and that this elongation is largely explained by increases in midpiece length. In snakes, the midpiece is comparatively large and it contains structures, which in other taxa are present in the rest of the flagellum, suggesting that it may integrate some of its functions. Thus, increases in sperm midpiece size would result in more energy as well as greater propulsion force. Sperm competition also increases the area occupied by the fibrous sheath and outer dense fibers within the sperm midpiece, revealing for the first time an effect upon structural elements within the sperm. Finally, differences in male-male encounter rates between oviparous and viviparous species seem to lead to differences in levels of sperm competition. We conclude that the influence of sperm competition upon different sperm components varies between taxa, because their structure and function is different.

Association of sperm apoptosis and DNA ploidy with sperm chromatin quality in human spermatozoa.

Science.gov (United States)

Mahfouz, Reda Z; Sharma, Rakesh K; Said, Tamer M; Erenpreiss, Juris; Agarwal, Ashok

2009-04-01

To examine the relationship among sperm apoptosis, sperm chromatin status, and DNA ploidy in different sperm fractions. Prospective study. Reproductive research center in a tertiary care hospital. Sperm prepared by density gradient were evaluated for sperm count, motility, apoptosis, and sperm chromatin assessment. Sperm count, sperm motility, toluidine blue (TB) results, DNA fragmentation index (%DFI), high DNA stainability, DNA cytometry, and early and late apoptosis. Sperm motility was related to late apoptotic and subhaploid apoptotic sperm (r = -0.56 and -0.53, respectively). The sperm %DFI showed significant correlation with late apoptotic and subhaploid sperm (r = 0.62 and 0.68). TB-stained sperm were significantly correlated with late apoptotic sperm (r = 0.51). Significantly higher proportions of haploid sperm and light blue TB-stained sperm were seen in mature compared with immature fractions. Even in semen samples with low %DFI, semen processing results in a lower incidence of nuclear immaturity and subhaploidy, but the incidence of late apoptotic sperm remains unchanged. Therefore, simultaneous evaluation of apoptosis and sperm chromatin status is important for processing sperm in assisted reproductive procedures.

Subversive practices of sperm donation - globalizing Danish sperm

DEFF Research Database (Denmark)

Willum Adrian, Stine

as the use of donated sperm continuously has been debated as an ethical issue, and increasingly been regulated. In this presentation I will discuss how Denmark became a destination for fertility travelling (sperm donation) as a result of various subversive strategies of family making. The article inquires......-sited ethnography drawing on ethnographic research including observations and interviews from fertility clinics and sperm banks in Denmark during 2002/2003 and 2011- 2013, legislative documents and websites of fertility clinics and sperm banks. The presentation is methodologically inspired by Adele Clarke...

What use is an infertile sperm? A comparative study of sperm-heteromorphic Drosophila

DEFF Research Database (Denmark)

Holman, Luke; Freckleton, Robert P; Snook, Rhonda R

2007-01-01

Sperm size and number are important determinants of male reproductive success. The genus Drosophila exhibits a remarkable diversity of sperm production strategies, including the production of multiple sperm morphs by individual males, a phenomenon called sperm heteromorphism. Sperm-heteromorphic ......Sperm size and number are important determinants of male reproductive success. The genus Drosophila exhibits a remarkable diversity of sperm production strategies, including the production of multiple sperm morphs by individual males, a phenomenon called sperm heteromorphism. Sperm......-heteromorphic Drosophila species in the obscura group produce large numbers of infertile "parasperm" in addition to fertile eusperm. Parasperm have been hypothesized to perform a number of roles in place of fertilization, predominantly focused on their potential function in postcopulatory sexual selection. However...

The Atiyah bundle and connections on a principal bundle

Indian Academy of Sciences (India)

be the fiber bundle constructed as in (1.1) for the universal principal G-bundle. In a work in progress, we hope to show that the universal G-connection can be realized as a fiber bundle over C(EG). Turning this ... a G-invariant vector field on EG|U . In other words, we get a bijective linear map between. A(EG)(U) (the space of ...

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours.

Science.gov (United States)

Iwata, Yoko; Shaw, Paul; Fujiwara, Eiji; Shiba, Kogiku; Kakiuchi, Yasutaka; Hirohashi, Noritaka

2011-08-10

Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

Directory of Open Access Journals (Sweden)

Shiba Kogiku

2011-08-01

Full Text Available Abstract Background Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm. Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Results Large consort males transfer smaller (average total length = 73 μm sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Conclusions Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external, whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

Relationship between sperm parameters and intracytoplasmic sperm injection outcome

Directory of Open Access Journals (Sweden)

Shahla Chaichian

2015-12-01

Full Text Available Objectives: With the adventure of intracytoplasmic sperm injection (ICSI technique, great progresses have developed in the treatment of infertility. Concentration on the properties of male’s gamete has been encouraged by the increasing concerns about the causes of ICSI failure. We hence conducted this study to investigate the probable association of sperm parameters with ISCI outcome. Methods: A total of 523 couples referred to Isfahan Fertility and Sterility Center from January 2007 to June 2008 for ICSI. Semen analysis was performed before ICSI procedure according to the WHO criteria. Patients were assigned into successful ICSI (case and failed ICSI (control groups. Sperm parameters were then compared between the 2 groups. Results: One hundred and six patients (20% had successful ICSI results (case group compared with 417 couples (80% with undesirable ICSI outcomes (control group. Among evaluated factors, sperm agglutination (p = 0.007, sperm concentration (p = 0.043, leukocytospermia (p = 0.026 and head abnormality of sperm (p = 0.019 showed statistically significant differences between two groups with differing ICSI results. None of the other semen parameters revealed significant differences between these two groups. Conclusion: Our study showed that some sperm parameters are associated with desirable ICSI outcome. However, it is unclear whether these associations are causal.

Polyelectrolyte bundles

Energy Technology Data Exchange (ETDEWEB)

Limbach, H J; Sayar, M; Holm, C [Max-Planck-Institut fuer Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)

2004-06-09

Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited.

Polyelectrolyte bundles

International Nuclear Information System (INIS)

Limbach, H J; Sayar, M; Holm, C

2004-01-01

Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited

Polyelectrolyte bundles

Science.gov (United States)

Limbach, H. J.; Sayar, M.; Holm, C.

2004-06-01

Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter range relevant for sulfonated poly-para-phenylenes (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting to the possibility that the size of DNA aggregates is under certain circumstances thermodynamically limited.

Relationship between Porcine Sperm Motility and Sperm Enzymatic Activity using Paper-based Devices

Science.gov (United States)

Matsuura, Koji; Huang, Han-Wei; Chen, Ming-Cheng; Chen, Yu; Cheng, Chao-Min

2017-04-01

Mammalian sperm motility has traditionally been analyzed to determine fertility using computer-assisted semen analysis (CASA) systems. To develop low-cost and robust male fertility diagnostics, we created a paper-based MTT assay and used it to estimate motile sperm concentration. When porcine sperm motility was inhibited using sperm enzyme inhibitors for sperm enzymes related to mitochondrial activity and glycolysis, we simultaneously recorded sperm motility and enzymatic reactivity using a portable motility analysis system (iSperm) and a paper-based MTT assay, respectively. When using our paper-based MTT-assay, we calculated the area mean value signal intensity (AMV) to evaluate enzymatic reactivity. Both sperm motility and AMV decreased following treatment with iodoacetamide (IODO) and 3-bromopyruvic acid (3BP), both of which are inhibitors of glycolytic enzymes including glyceraldehyde-3-phosphate dehydrogenase (GAPDH). We found a correlation between recorded motility using iSperm and AMV from our paper-based assay (P Based on this inhibitor study, sperm motility can be estimated using our paper-based MTT-assay.

Strategic Aspects of Bundling

International Nuclear Information System (INIS)

Podesta, Marion

2008-01-01

The increase of bundle supply has become widespread in several sectors (for instance in telecommunications and energy fields). This paper review relates strategic aspects of bundling. The main purpose of this paper is to analyze profitability of bundling strategies according to the degree of competition and the characteristics of goods. Moreover, bundling can be used as price discrimination tool, screening device or entry barriers. In monopoly case bundling strategy is efficient to sort consumers in different categories in order to capture a maximum of surplus. However, when competition increases, the profitability on bundling strategies depends on correlation of consumers' reservations values. (author)

Sperm length, sperm storage and mating system characteristics in bumblebees

DEFF Research Database (Denmark)

Baer, Boris; Schmid-Hempel, Paul; Høeg, Jens Thorvald

2003-01-01

-term storage of sperm, using three bumblebee species with different mating systems as models. We show that individual males produce only one size-class of sperm, but that sperm length is highly variable among brothers, among unrelated conspecific males, and among males of different species. Males of Bombus...

Nonabelian bundle 2-gerbes

OpenAIRE

Jurco, Branislav

2009-01-01

We define 2-crossed module bundle 2-gerbes related to general Lie 2-crossed modules and discuss their properties. A 2-crossed module bundle 2-gerbe over a manifold is defined in terms of a so called 2-crossed module bundle gerbe, which is a crossed module bundle gerbe equipped with an extra sructure. It is shown that string structures can be described and classified using 2-crossed module bundle 2-gerbes.

Improving sperm banking efficiency in endangered species through the use of a sperm selection method in brown bear (Ursus arctos) thawed sperm.

Science.gov (United States)

Anel-Lopez, L; Ortega-Ferrusola, C; Álvarez, M; Borragán, S; Chamorro, C; Peña, F J; Morrell, J; Anel, L; de Paz, P

2017-06-26

Sperm selection methods such as Single Layer Centrifugation (SLC) have been demonstrated to be a useful tool to improve the quality of sperm samples and therefore to increase the efficiency of other artificial reproductive techniques in several species. This procedure could help to improve the quality of genetic resource banks, which is essential for endangered species. In contrast, these sperm selection methods are optimized and focused on farm animals, where the recovery task is not as important as in endangered species because of their higher sperm availability. The aim of this study was to evaluate two centrifugation methods (300 x g/20 min and 600 x g/10 min) and three concentrations of SLC media (Androcoll-Bear -80, 65 and 50%) to optimise the procedure in order to recover as many sperm with the highest quality as possible. Sperm morphology could be important in the hydrodynamic relationship between the cell and centrifugation medium and thus the effect of sperm head morphometry on sperm yield and its hydrodynamic relationship were studied. The samples selected with Androcoll-Bear 65% showed a very good yield (53.1 ± 2.9) although the yield from Androcoll-Bear 80% was lower (19.3 ± 3.3). The latter showed higher values of motility than the control immediately after post-thawing selection. However, both concentrations of colloid (65 and 80%) showed higher values of viable sperm and viable sperm with intact acrosome than the control. After an incubation of 2 h at 37 °C, the samples from Androcoll-Bear 80% had higher kinematics and proportion of viable sperm with intact acrosome. In the morphometric analysis, the sperm selected by the Androcoll-Bear 80% showed a head with a bigger area which was more elongated than the sperm from other treatments. We conclude that sperm selection with Androcoll-Bear at either 65% or 80% is a suitable technique that allows a sperm population with better quality than the initial sample to be obtained. We recommend the

Polycation induced actin bundles.

Science.gov (United States)

Muhlrad, Andras; Grintsevich, Elena E; Reisler, Emil

2011-04-01

Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4Å) MTS-1 (1,1-methanedyl bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

Analysis of limited fertility in intracytoplasmic sperm injection of sperm obtained by electroejaculation

Science.gov (United States)

Nakamura, Yoshihiro; Kitamura, Masaya; Nishimura, Kenji; Tsujimura, Akira; Takeyama, Masami; Kondoh, Nobuyuki; Miyazaki, Kazunori; Okuyama, Akihiko

2004-01-01

Background and Aims:  We correlated findings in semen from patients with ejaculatory dysfunction with results of in vitro fertilization using their electroejaculated sperm. Methods and Results:  Electroejaculation was carried out in six patients with the above‐mentioned criteria for a total of eight times. Sperm was obtained in six attempts. Intracytoplasmic injection of these sperm was performed in 156 eggs. Sixty‐seven eggs were fertilized; most of these were injected with motile sperm. Two women became pregnant, both after injection with motile sperm. As previously reported, electroejaculated sperm showed low motility and a low fertilization rate, but even motile sperm had a low fertilization rate. Conclusion:  The results of the present study suggest the importance in fertilization of undetermined factors in addition to sperm motility. (Reprod Med Biol 2004; 3: 9–12) PMID:29662380

No evidence of trade-offs in the evolution of sperm numbers and sperm size in mammals.

Science.gov (United States)

Tourmente, M; Delbarco Trillo, J; Roldan, E R S

2015-10-01

Post-copulatory sexual selection, in the form sperm competition, has influenced the evolution of several male reproductive traits. However, theory predicts that sperm competition would lead to trade-offs between numbers and size of spermatozoa because increased costs per cell would result in a reduction of sperm number if both traits share the same energetic budget. Theoretical models have proposed that, in large animals, increased sperm size would have minimal fitness advantage compared with increased sperm numbers. Thus, sperm numbers would evolve more rapidly than sperm size under sperm competition pressure. We tested in mammals whether sperm competition maximizes sperm numbers and size, and whether there is a trade-off between these traits. Our results showed that sperm competition maximizes sperm numbers in eutherian and metatherian mammals. There was no evidence of a trade-off between sperm numbers and sperm size in any of the two mammalian clades as we did not observe any significant relationship between sperm numbers and sperm size once the effect of sperm competition was taken into account. Maximization of both numbers and size in mammals may occur because each trait is crucial at different stages in sperm's life; for example size-determined sperm velocity is a key determinant of fertilization success. In addition, numbers and size may also be influenced by diverse energetic budgets required at different stages of sperm formation. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Daily Sperm Production, Gonadal and Extra-Gonadal Sperm ...

African Journals Online (AJOL)

SH

animals fed diets 2 and 3 were similar to the control animals but they were significantly (P<0.05) lower than those fed ... Keywords: Prebiotics, probiotics, rabbits, sperm reserves, sperm production. ... Materials and methods .... In: Handbook of.

Nefness of adjoint bundles for ample vector bundles

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Hidetoshi Maeda

1995-11-01

Full Text Available Let E be an ample vector bundle of rank >1 on a smooth complex projective variety X of dimension n. This paper gives a classification of pairs (X,E whose adjoint bundles K_X+det E are not nef in the case when  r=n-2.

The stochastic dance of circling sperm cells: sperm chemotaxis in the plane

Energy Technology Data Exchange (ETDEWEB)

Friedrich, B M; Juelicher, F [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, 01187 Dresden (Germany)], E-mail: ben@pks.mpg.de, E-mail: julicher@pks.mpg.de

2008-12-15

Biological systems such as single cells must function in the presence of fluctuations. It has been shown in a two-dimensional experimental setup that sea urchin sperm cells move toward a source of chemoattractant along planar trochoidal swimming paths, i.e. drifting circles. In these experiments, a pronounced variability of the swimming paths is observed. We present a theoretical description of sperm chemotaxis in two dimensions which takes fluctuations into account. We derive a coarse-grained theory of stochastic sperm swimming paths in a concentration field of chemoattractant. Fluctuations enter as multiplicative noise in the equations for the sperm swimming path. We discuss the stochastic properties of sperm swimming and predict a concentration-dependence of the effective diffusion constant of sperm swimming which could be tested in experiments.

The stochastic dance of circling sperm cells: sperm chemotaxis in the plane

International Nuclear Information System (INIS)

Friedrich, B M; Juelicher, F

2008-01-01

Biological systems such as single cells must function in the presence of fluctuations. It has been shown in a two-dimensional experimental setup that sea urchin sperm cells move toward a source of chemoattractant along planar trochoidal swimming paths, i.e. drifting circles. In these experiments, a pronounced variability of the swimming paths is observed. We present a theoretical description of sperm chemotaxis in two dimensions which takes fluctuations into account. We derive a coarse-grained theory of stochastic sperm swimming paths in a concentration field of chemoattractant. Fluctuations enter as multiplicative noise in the equations for the sperm swimming path. We discuss the stochastic properties of sperm swimming and predict a concentration-dependence of the effective diffusion constant of sperm swimming which could be tested in experiments.

Use of testicular sperm for intracytoplasmic sperm injection in men with high sperm DNA fragmentation: a SWOT analysis.

Science.gov (United States)

Esteves, Sandro C; Roque, Matheus; Garrido, Nicolás

2018-01-01

Spermatozoa retrieved from the testis of men with high levels of sperm DNA fragmentation (SDF) in the neat semen tend to have better DNA quality. Given the negative impact of SDF on the outcomes of Assisted Reproductive Technology (ART), an increased interest has emerged about the use of testicular sperm for intracytoplasmic sperm injection (Testi-ICSI). In this article, we used a SWOT (strengths, weaknesses, opportunities, and threats) analysis to summarize the advantages and drawbacks of this intervention. The rationale of Testi-ICSI is bypass posttesticular DNA fragmentation caused by oxidative stress during sperm transit through the epididymis. Hence, oocyte fertilization by genomically intact testicular spermatozoa may be optimized, thus increasing the chances of creating a normal embryonic genome and the likelihood of achieving a live birth, as recently demonstrated in men with high SDF. However, there is still limited evidence as regards the clinical efficacy of Testi-ICSI, thus creating opportunities for further confirmatory clinical research as well as investigation of Testi-ICSI in clinical scenarios other than high SDF. Furthermore, Testi-ICSI can be compared to other laboratory preparation methods for deselecting sperm with damaged DNA. At present, the available literature supports the use of testicular sperm when performing ICSI in infertile couples whose male partners have posttesticular SDF. Due to inherent risks of sperm retrieval, Testi-ICSI should be offered when less invasive treatments for alleviating DNA damage have failed. A call for continuous monitoring is nonetheless required concerning the health of generated offspring and the potential complications of sperm retrieval.

Sperm competition leads to functional adaptations in avian testes to maximize sperm quantity and quality.

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Lüpold, Stefan; Wistuba, Joachim; Damm, Oliver S; Rivers, James W; Birkhead, Tim R

2011-05-01

The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and sperm length or sperm energetics). Comparative studies have shown positive associations between the level of sperm competition and both relative testis size and the proportion of seminiferous (sperm-producing) tissue within the testes. However, it is unknown how the seminiferous tissue itself or the process of spermatogenesis might evolve in response to sperm competition. Therefore, we quantified the different germ cell types and Sertoli cells (SC) in testes to assess the efficiency of sperm production and its associations with sperm length and mating system across 10 species of New World Blackbirds (Icteridae) that show marked variation in sperm length and sperm competition level. We found that species under strong sperm competition generate more round spermatids (RS)/spermatogonium and have SC that support a greater number of germ cells, both of which are likely to increase the maximum sperm output. However, fewer of the RS appeared to elongate to mature spermatozoa in these species, which might be the result of selection for discarding spermatids with undesirable characteristics as they develop. Our results suggest that, in addition to overall size and gross morphology, testes have also evolved functional adaptations to maximize sperm quantity and quality.

Evaluation of bundle duct interaction by out of pile compressive test of FBR bundles. FFTF type bundle

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Kosuke; Yamamoto, Yuji; Nagamine, Tsuyoshi; Maeda, Koji [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

2000-10-01

Bundle duct interaction (BDI) caused by expansion of fuel pin bundle becomes one of the main limiting factors for fuel life times. Then, it is important for the design of fast reactor fuel assembly to understand the BDI behavior in detail. In order to understand the BDI behavior, out of pile compressive tests were conducted for FFTF type bundle by use of X-ray CT equipment. In these compressive tests, two type bundles with different accuracy of initial wire position were conducted. The objective of this test is to evaluate the influence of the initial error from standard position of wire at the same axial position. The locations of the pins and the duct flats are analyzed from CT image data. Quantitative evaluation was performed at the CT image data and discussed the bundle deformation status under BDI condition. Following results are obtained. 1) The accuracy of initial wire position is strongly depends on the pin-to-duct contact behavior. In the case of bundle with large error from standard position, pin-to-duct contact is delayed. 2) The BDI mitigation of the bundle with small error from standard wire position is following: The elastic ovality is the dominant deformation in mild BDI condition, then the wire dispersion and pin dispersion are occurred in severe BDI condition. 3) The BDI mitigation of the bundle with large error from standard wire position is following: The elastic ovality and local bowing of pins with large error from standard wire position are occurred in mild BDI condition, then pin dispersion is occurred around pins with large error from standard wire position, finally wire dispersion is occurred in severe BDI condition. 4) The existence of pins with large error from standard wire position is effective to delay the pin-to-duct contact, but the existence of these pins is possible to contact of pin- to- pin. (author)

On the relative effect of spawning asynchrony, sperm quantity and sperm quality on paternity under sperm competition in an external fertilizer

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Torvald Blikra Egeland

2015-07-01

Full Text Available How much of a fitness benefit is obtained by dominant males of external fertilizers from releasing ejaculates in synchrony with female egg-release when engaging in sperm competition, and what is the most important sperm trait for paternity in these situations? The Arctic charr (Salvelinus alpinus is an external fertilizer experiencing intense male-male competition over reproductive opportunities including sperm competition. To compensate for their disadvantage the sneaker males, which often spawn out of synchrony with the female, produce more and faster sperm than the guarding males. We used controlled in vitro fertilization trials with experimentally produced dominant and subordinate, sneaker males to test what effect relative synchrony in gamete release, sperm quality (i.e., motility and velocity and sperm quantity have on a male’s fertilization success in pair-wise sperm competitions. When the sneaker males released ejaculates after the guarding male there was no overall difference in fertilization success. The quality (i.e., motility and velocity of a male’s sperm relative to that of the competing male was the best predictor of male fertilization success regardless of their mating tactic and spawning synchrony. The relative number of sperm cells also had an effect on fertilization success, but mainly when the dominant and sneaker male ejaculated synchronously. Our close imitation of natural sperm competition in charr shows that the sneaker males of external fertilizing species may fully compensate for their disadvantaged mating role by producing ejaculates of higher quality - an adjustment strangely not met by dominants.

Effect of an isotonic lubricant on sperm collection and sperm quality.

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Agarwal, Ashok; Malvezzi, Helena; Sharma, Rakesh

2013-05-01

To assess the influence of an isotonic lubricant used during sperm sample collection on [1] ease of collection and [2] resultant sperm quality. Paired randomized cross-over design. Tertiary hospital. Healthy men over 18 years old with normal semen analysis as per World Health Organization 2010 guidelines. Collection of semen sample from 22 subjects by masturbation with or without the use of Pre-Seed personal lubricant. Qualitative survey results and quantitative sperm function outcomes were measured to determine resultant sperm quality and collection experience with and without Pre-Seed lubricant. The qualitative questionnaire results showed that 73% of donors prefer the semen collection process with the isotonic lubricant and 55% recommended the use of lubricant in their everyday collection. The motility, viability, membrane integrity, levels of reactive oxygen species, total antioxidant capacity, and percentage of DNA damage in collected semen samples were not affected by the use of the lubricant. More donors prefer, and find it easier, to collect semen samples with the use of the lubricant. The isotonic lubricant Pre-Seed did not compromise sperm quality as evaluated in an array of sperm assays, suggesting its safe use in fertility patients as required during sperm collection. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Birefringence of single and bundled microtubules.

Science.gov (United States)

Oldenbourg, R; Salmon, E D; Tran, P T

1998-01-01

We have measured the birefringence of microtubules (MTs) and of MT-based macromolecular assemblies in vitro and in living cells by using the new Pol-Scope. A single microtubule in aqueous suspension and imaged with a numerical aperture of 1.4 had a peak retardance of 0.07 nm. The peak retardance of a small bundle increased linearly with the number of MTs in the bundle. Axonemes (prepared from sea urchin sperm) had a peak retardance 20 times higher than that of single MTs, in accordance with the nine doublets and two singlets arrangement of parallel MTs in the axoneme. Measured filament retardance decreased when the filament was defocused or the numerical aperture of the imaging system was decreased. However, the retardance "area," which we defined as the image retardance integrated along a line perpendicular to the filament axis, proved to be independent of focus and of numerical aperture. These results are in good agreement with a theory that we developed for measuring retardances with imaging optics. Our theoretical concept is based on Wiener's theory of mixed dielectrics, which is well established for nonimaging applications. We extend its use to imaging systems by considering the coherence region defined by the optical set-up. Light scattered from within that region interferes coherently in the image point. The presence of a filament in the coherence region leads to a polarization dependent scattering cross section and to a finite retardance measured in the image point. Similar to resolution measurements, the linear dimension of the coherence region for retardance measurements is on the order lambda/(2 NA), where lambda is the wavelength of light and NA is the numerical aperture of the illumination and imaging lenses.

Theletrum lamothei sp. nov. (Digenea, parasite of Echidna nocturna from Cuajiniquil, Guanacaste, and other digenes of marine fishes from Costa Rica

Directory of Open Access Journals (Sweden)

Gerardo Pérez-Ponce de León

1998-06-01

Full Text Available A new species of Theletrum is described from the intestine of two palenose morays, Echidna nocturna, collected in Cuajiniquil, Guanacaste Province, Costa Rica. The new species differs from the type species, T. fustiforme Linton, 1910 by having a subspherical pars prostatica, a subspherical seminal vesicle extending anteriorly to the anterior border of the acetabulum, by the presence of a poorly developed hermaphroditic sac, and by having a larger body size. We also report eight additional species of digeneans parasitizing marine fishes in several localities along the Atlantic and Pacific coast of Costa Rica: Bianium simonei, Didymozoinae (metacercariae, Ectenurus virgulus, Hypocreadium myohelicatum, Lecithochirium microstomum, Pseudolecithaster sp., Stephanostomum casum, and Tergestia laticollis. In addition, we present an updated list of helminth parasites of marine fish from Costa Rica and discuss the importance of including parasites as an integral part of biodiversity inventories.Se describe una especie nueva de digéneo del género Theletrum, parásito del intestino de una "morena pecosa", Echidna nocturna, recolectada en Playa Cuajiniquil, Provincia de Guanacaste, Costa Rica. La nueva especie es diferente de T. fustiforme Linton, 1910, la especie tipo, por presentar una pars prostatica subesférica, una vesícula seminal subesférica que se extiende hasta el borde anterior del acetábulo, por la presencia de un saco hermafrodita y por una mayor longitud del cuerpo. También se registran ocho especies adicionales de digéneos parásitos de peces marinos en varias localidades de las costas del Atlántico y del Pacífico de Costa Rica. Por último, presentamos una lista actualizada de los helmintos parásitos de peces marinos y dulceacuícolas de Costa Rica y discutimos la importancia de incluir a los parásitos como una parte integral de las investigaciones sobre biodiversidad.

Different computer-assisted sperm analysis (CASA) systems highly influence sperm motility parameters.

Science.gov (United States)

Boryshpolets, S; Kowalski, R K; Dietrich, G J; Dzyuba, B; Ciereszko, A

2013-10-15

In this study, we examined different computer-assisted sperm analysis (CASA) systems (CRISMAS, Hobson Sperm Tracker, and Image J CASA) on the exact same video recordings to evaluate the differences in sperm motility parameters related to the specific CASA used. To cover a wide range of sperm motility parameters, we chose 12-second video recordings at 25 and 50 Hz frame rates after sperm motility activation using three taxonomically distinct fish species (sterlet: Acipenser ruthenus L.; common carp: Cyprinus carpio L.; and rainbow trout: Oncorhynchus mykiss Walbaum) that are characterized by essential differences in sperm behavior during motility. Systematically higher values of velocity and beat cross frequency (BCF) were observed in video recordings obtained at 50 Hz frame frequency compared with 25 Hz for all three systems. Motility parameters were affected by the CASA and species used for analyses. Image J and CRISMAS calculated higher curvilinear velocity (VCL) values for rainbow trout and common carp at 25 Hz frequency compared with the Hobson Sperm Tracker, whereas at 50 Hz, a significant difference was observed only for rainbow trout sperm recordings. No significant difference was observed between the CASA systems for sterlet sperm motility at 25 and 50 Hz. Additional analysis of 1-second segments taken at three time points (1, 6, and 12 seconds of the recording) revealed a dramatic decrease in common carp and rainbow trout sperm speed. The motility parameters of sterlet spermatozoa did not change significantly during the 12-second motility period and should be considered as a suitable model for longer motility analyses. Our results indicated that the CASA used can affect motility results even when the same motility recordings are used. These results could be critically altered by the recording quality, time of analysis, and frame rate of camera, and could result in erroneous conclusions. Copyright © 2013 Elsevier Inc. All rights reserved.

The Effect of Glyphosate on Human Sperm Motility and Sperm DNA Fragmentation

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George Anifandis

2018-05-01

Full Text Available Glyphosate is the active ingredient of Roundup®, which is one of the most popular herbicides worldwide. Although many studies have focused on the reproductive toxicity of glyphosate or glyphosate-based herbicides, the majority of them have concluded that the effect of the specific herbicide is negligible, while only a few studies indicate the male reproductive toxicity of glyphosate alone. The aim of the present study was to investigate the effect of 0.36 mg/L glyphosate on sperm motility and sperm DNA fragmentation (SDF. Thirty healthy men volunteered to undergo semen analysis for the purpose of the study. Sperm motility was calculated according to WHO 2010 guidelines at collection time (zero time and 1 h post-treatment with glyphosate. Sperm DNA fragmentation was evaluated with Halosperm® G2 kit for both the control and glyphosate-treated sperm samples. Sperm progressive motility of glyphosate-treated samples was significantly reduced after 1 h post-treatment in comparison to the respective controls, in contrast to the SDF of glyphosate-treated samples, which was comparable to the respective controls. Conclusively, under these in vitro conditions, at high concentrations that greatly exceed environmental exposures, glyphosate exerts toxic effects on sperm progressive motility but not on sperm DNA integrity, meaning that the toxic effect is limited only to motility, at least in the first hour.

Factors influencing boar sperm cryosurvival.

Science.gov (United States)

Roca, J; Hernández, M; Carvajal, G; Vázquez, J M; Martínez, E A

2006-10-01

Optimal sperm cryopreservation is a prerequisite for the sustainable commercial application of frozen-thawed boar semen for AI. Three experiments were performed to identify factors influencing variability of postthaw sperm survival among 464 boar ejaculates. Sperm-rich ejaculate fractions were cryopre-served using a standard freezing-thawing procedure for 0.5-mL plastic straws and computer-controlled freezing equipment. Postthaw sperm motility (assessed with a computer-assisted semen analysis system) and viability (simultaneously probed by flow cytometry analysis after triple-fluorescent stain), evaluated 30 and 150 min postthaw, were used to estimate the success of cryopreservation. In the first experiment, 168 unselected ejaculates (1 ejaculate/boar), from boars of 6 breeds with a wide age range (8 to 48 mo), were cryopreserved over a 12-mo period to evaluate the predictive value of boar (breed and age), semen collection, transport variables (season of ejaculate collection, interval between collections, and ejaculate temperature exposure), initial semen traits, and sperm quality before freezing on sperm survival after freezing-thawing. In Exp. 2, 4 ejaculates from each of 29 boars, preselected according to their initial semen traits and sperm quality before freezing, were collected and frozen over a 6-mo period to evaluate the influence of interboar and intraboar ejaculate variability in the survival of sperm after cryopreservation. In Exp. 3, 12 ejaculates preselected as for Exp. 2, from each of 15 boars with known good sperm cryosurvival, were collected and frozen over a 12-mo period to estimate the sustainability of sperm cryosurvival between ejaculates over time. Boar and semen collection and transport variables were not predictive of sperm cryosurvival among ejaculates. Initial semen traits and sperm quality variables observed before freezing explained 23.2 and 10.9%, respectively, of the variation in postthaw sperm motility and viability. However, more that

Ascidian Sperm Lysin System

OpenAIRE

Hitoshi, Sawada; Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University

2002-01-01

Fertilization is a precisely controlled process involving many gamete molecules in sperm binding to and penetration through the extracellular matrix of the egg. After sperm bind to the extracellular matrix (vitelline coat), they undergo the acrosome reaction which exposes and partially releases a lytic agent called "lysin" to digest the vitelline coat for the sperm penetration. The vitelline coat sperm lysin is generally a protease in deuterostomes. The molecular mechanism of the actual degra...

Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

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Lourdes Gallego-Calvo

2015-12-01

Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.

Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

Energy Technology Data Exchange (ETDEWEB)

Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.

2015-07-01

Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)

Phenotypic plasticity in sperm traits in scorpionflies (Mecoptera : Panorpidae): Consequences of larval history and seasonality on sperm length and sperm transfer

NARCIS (Netherlands)

Vermeulen, Andreas; Engels, Sierk; Engqvist, Leif; Sauer, Klaus Peter

2009-01-01

We examined effects of seasonality, larval food availability and larval rearing density on sperm length, sperm transfer rates and body size in the bivoltine scorpionfly Panorpa vulgaris. Males of the first annual generation were larger and had larger sperm. Comparing individuals of two summer

Sperm preparation for fertilization

NARCIS (Netherlands)

Gadella, B.M.

2014-01-01

Description This book contains 19 chapters that discuss theoretical and applied andrology for domestic, zoo and wild animals. Topics include semen and its constituents; sperm production and harvest; determinants of sperm morphology; sperm preparation for fertilization; practical aspects of semen

Sperm fractions obtained following density gradient centrifugation in human ejaculates show differences in sperm DNA longevity

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Jaime Gosálvez

2014-06-01

Conclusion: 1 Unnecessary incubation of spermatozoa prior to artificial insemination or in vitro fertilization, should be avoided, since sperm DNA longevity is significantly reduced after ex vivo sperm handling and 2 Although sperm selection by DCG significantly reduces the baseline levels of SDF of sperm in Fraction 3, sperm DNA longevity in this fraction was ultimately lower following 24 h incubation when compared to sperm recovered from non-centrifuged NSS.

Influence of Post-Mortem Sperm Recovery Method and Extender on Unstored and Refrigerated Rooster Sperm Variables.

Science.gov (United States)

Villaverde-Morcillo, S; Esteso, M C; Castaño, C; Santiago-Moreno, J

2016-02-01

Many post-mortem sperm collection techniques have been described for mammalian species, but their use in birds is scarce. This paper compares the efficacy of two post-mortem sperm retrieval techniques - the flushing and float-out methods - in the collection of rooster sperm, in conjunction with the use of two extenders, i.e., L&R-84 medium and Lake 7.1 medium. To determine whether the protective effects of these extenders against refrigeration are different for post-mortem and ejaculated sperm, pooled ejaculated samples (procured via the massage technique) were also diluted in the above extenders. Post-mortem and ejaculated sperm variables were assessed immediately at room temperature (0 h), and after refrigeration at 5°C for 24 and 48 h. The flushing method retrieved more sperm than the float-out method (596.5 ± 75.4 million sperm vs 341.0 ± 87.6 million sperm; p < 0.05); indeed, the number retrieved by the former method was similar to that obtained by massage-induced ejaculation (630.3 ± 78.2 million sperm). For sperm collected by all methods, the L&R-84 medium provided an advantage in terms of sperm motility variables at 0 h. In the refrigerated sperm samples, however, the Lake 7.1 medium was associated with higher percentages of viable sperm, and had a greater protective effect (p < 0.05) with respect to most motility variables. In conclusion, the flushing method is recommended for collecting sperm from dead birds. If this sperm needs to be refrigerated at 5°C until analysis, Lake 7.1 medium is recommended as an extender. © 2015 Blackwell Verlag GmbH.

More Pitfalls with Sperm Viability Staining and a Viability-Based Stress Test to Characterize Sperm Quality

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Barbara A. Eckel

2017-12-01

Full Text Available Sperm viability (SV, the proportion of live sperm in a sample, is a widely applied measure of sperm quality but few studies test its robustness. At least three reasons make SV problematic as a surrogate for sperm quality. First, reviewing the ecological literature revealed that previously identified methodological pitfalls have not been overcome, including low cross-study standardization of protocols, inadequate statistical treatment, and unaccounted for within-sample heterogeneity. Second, SV is affected by biological variation such as between species, reproductive organs, or sperm age cohorts. Third, the proportion of live sperm extracted from males appears more related to male than to sperm quality in the sense of the future performance of sperm. We propose an alternative method to assess sperm quality by characterizing the temporal decrease of SV in a stressor medium and illustrate in two species, the common bedbug (Cimex lectularius and the fruit fly (Drosophila melanogaster how some common methodological pitfalls may be circumvented. Our data empirically support the well-known but little-considered facts that (i non-blind measurements may alter SV and (ii that SV frequently have non-significant repeatability within one sample. (iii Cross-sectional sampling of ejaculates showed that this heterogeneity even masked a biological pattern—the sperm stratification within males. We show (iv that this shortcoming can be overcome by following the temporal decline of SV of a sperm subsample in a stress test. Finally, (v comparing the staining pattern of sperm between Cimex and Drosophila, we found that in the latter, the visibility of sperm is substantially delayed (30 min when sperm density is high. We show that this delay in stained sperm visibility was, however, not biased toward dead or live sperm. To measure sperm quality, we advocate analyzing the temporal decline in SV in a stressor medium over current protocols that use SV per se and

Rheotaxis guides mammalian sperm

Science.gov (United States)

Miki, Kiyoshi; Clapham, David E

2013-01-01

Background In sea urchins, spermatozoan motility is altered by chemotactic peptides, giving rise to the assumption that mammalian eggs also emit chemotactic agents that guide spermatozoa through the female reproductive tract to the mature oocyte. Mammalian spermatozoa indeed undergo complex adaptations within the female (the process of capacitation) that are initiated by agents ranging from pH to progesterone, but these factors are not necessarily taxic. Currently, chemotaxis, thermotaxis, and rheotaxis have not been definitively established in mammals. Results Here, we show that positive rheotaxis, the ability of organisms to orient and swim against the flow of surrounding fluid, is a major taxic factor for mouse and human sperm. This flow is generated within 4 hours of sexual stimulation and coitus in female mice; prolactin-triggered oviductal fluid secretion clears the oviduct of debris, lowers viscosity, and generates the stream that guides sperm migration in the oviduct. Rheotaxic movement is demonstrated in capacitated and uncapacitated spermatozoa in low and high viscosity medium. Finally, we show that a unique sperm motion we quantify using the sperm head's rolling rate reflects sperm rotation that generates essential force for positioning the sperm in the stream. Rotation requires CatSper channels, presumably by enabling Ca2+ influx. Conclusions We propose that rheotaxis is a major determinant of sperm guidance over long distances in the mammalian female reproductive tract. Coitus induces fluid flow to guide sperm in the oviduct. Sperm rheotaxis requires rotational motion during CatSper channel-dependent hyperactivated motility. PMID:23453951

Bundle Branch Block

Science.gov (United States)

... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

Cryopreservation of microencapsulated canine sperm.

Science.gov (United States)

Shah, Shambhu; Otsuki, Tsubasa; Fujimura, Chika; Yamamoto, Naoki; Yamashita, Yasuhisa; Higaki, Shogo; Hishinuma, Mitsugu

2011-03-01

The objective was to develop a method for cryopreserving microencapsulated canine sperm. Pooled ejaculates from three beagle dogs were extended in egg yolk tris extender and encapsulated using alginate and poly-L-lysine at room temperature. The microcapsules were cooled at 4 °C, immersed in pre-cooled extender (equivalent in volume to the microcapsules) to reach final concentration of 7% (v/v) glycerol and 0.75% (v/v) Equex STM paste, and equilibrated for 5, 30 and 60 min at 4 °C. Thereafter, microcapsules were loaded into 0.5 mL plastic straws and frozen in liquid nitrogen. In Experiment 1, characteristics of microencapsulated canine sperm were evaluated after glycerol addition at 4 °C. Glycerol exposure for 5, 30 and 60 min did not significantly affect progressive motility, viability, or acrosomal integrity of microencapsulated sperm compared with pre-cooled unencapsulated sperm (control). In Experiment 2, characteristics of frozen-thawed canine microencapsulated sperm were evaluated at 0, 3, 6, and 9 h of culture at 38.5 °C. Pre-freeze glycerol exposure for 5, 30, and 60 min at 4 °C did not influence post-thaw quality in unencapsulated sperm. Post-thaw motility and acrosomal integrity of microencapsulated sperm decreased more than those of unencapsulated sperm (P < 0.05) following glycerol exposure for 5 min. However, motility, viability and acrosomal integrity of microencapsulated sperm after 30 and 60 min glycerol exposure were higher than unencapsulated sperm cultured for 6 or 9 h (P < 0.05). In conclusion, since microencapsulated canine sperm were successfully cryopreserved, this could be a viable alternative to convention sperm cryopreservation in this species. Copyright © 2011 Elsevier Inc. All rights reserved.

Ovarian fluid mediates the temporal decline in sperm viability in a fish with sperm storage.

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Clelia Gasparini

Full Text Available A loss of sperm viability and functionality during sperm transfer and storage within the female reproductive tract can have important fitness implications by disrupting fertilization and impairing offspring development and survival. Consequently, mechanisms that mitigate the temporal decline in sperm function are likely to be important targets of selection. In many species, ovarian fluid is known to regulate and maintain sperm quality. In this paper, we use the guppy Poecilia reticulata, a highly polyandrous freshwater fish exhibiting internal fertilization and sperm storage, to determine whether ovarian fluid (OF influences the decline in sperm viability (the proportion of live sperm in the ejaculate over time and whether any observed effects depend on male sexual ornamentation. To address these questions we used a paired experimental design in which ejaculates from individual males were tested in vitro both in presence and absence of OF. Our results revealed that the temporal decline in sperm viability was significantly reduced in the presence of OF compared to a saline control. This finding raises the intriguing possibility that OF may play a role in mediating the decline in sperm quality due to the deleterious effects of sperm ageing, although other possible explanations for this observation are discussed. Interestingly, we also show that the age-related decline in sperm viability was contingent on male sexual ornamentation; males with relatively high levels of iridescence (indicating higher sexual attractiveness exhibited a more pronounced decline in sperm viability over time than their less ornamented counterparts. This latter finding offers possible insights into the functional basis for the previously observed trade-off between these key components of pre- and postcopulatory sexual selection.

Effect of transfection and co-incubation of bovine sperm with exogenous DNA on sperm quality and functional parameters for its use in sperm-mediated gene transfer.

Science.gov (United States)

Arias, María Elena; Sánchez-Villalba, Esther; Delgado, Andrea; Felmer, Ricardo

2017-02-01

Sperm-mediated gene transfer (SMGT) is based on the capacity of sperm to bind exogenous DNA and transfer it into the oocyte during fertilization. In bovines, the progress of this technology has been slow due to the poor reproducibility and efficiency of the production of transgenic embryos. The aim of the present study was to evaluate the effects of different sperm transfection systems on the quality and functional parameters of sperm. Additionally, the ability of sperm to bind and incorporate exogenous DNA was assessed. These analyses were carried out by flow cytometry and confocal fluorescence microscopy, and motility parameters were also evaluated by computer-assisted sperm analysis (CASA). Transfection was carried out using complexes of plasmid DNA with Lipofectamine, SuperFect and TurboFect for 0.5, 1, 2 or 4 h. The results showed that all of the transfection treatments promoted sperm binding and incorporation of exogenous DNA, similar to sperm incorporation of DNA alone, without affecting the viability. Nevertheless, the treatments and incubation times significantly affected the motility parameters, although no effect on the integrity of DNA or the levels of reactive oxygen species (ROS) was observed. Additionally, we observed that transfection using SuperFect and TurboFect negatively affected the acrosome integrity, and TurboFect affected the mitochondrial membrane potential of sperm. In conclusion, we demonstrated binding and incorporation of exogenous DNA by sperm after transfection and confirmed the capacity of sperm to spontaneously incorporate exogenous DNA. These findings will allow the establishment of the most appropriate method [intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF)] of generating transgenic embryos via SMGT based on the fertilization capacity of transfected sperm.

Safety assessment for the CANFLEX-NU fuel bundles with respect to the 37-element fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Suk, H. C.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-11-01

The KAERI and AECL have jointly developed an advanced CANDU fuel, called CANFLEX-NU fuel bundle. CANFLEX 43-element bundle has some improved features of increased operating margin and enhanced safety compared to the existing 37-element bundle. Since CANFLEX fuel bundle is designed to be compatible with the CANDU-6 reactor design, the behaviour in the thermalhydraulic system will be nearly identical with 37-element bundle. But due to different element design and linear element power distribution between the two bundles, it is expected that CANFLEX fuel behaviour would be different from the behaviour of the 37-element fuel. Therefore, safety assessments on the design basis accidents which result if fuel failures are performed. For all accidents selected, it is observed that the loading of CANFLEX bundle in an existing CANDU-6 reactor would not worsen the reactor safety. It is also predicted that fission product release for CANFLEX fuel bundle generally is lower than that for 37-element bundle. 3 refs., 2 figs., 2 tabs. (Author)

Changes in Sperm Motility and Capacitation Induce Chromosomal Aberration of the Bovine Embryo following Intracytoplasmic Sperm Injection.

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Yoku Kato

Full Text Available Intracytoplasmic sperm injection (ICSI has become the method of choice to treat human male infertility. One of the outstanding problems associated with this technique is our current lack of knowledge concerning the effect of sperm capacitation and motility upon the subsequent development of oocytes following ICSI. In the present study, we first examined the capacitation state of sperm exhibiting normal motility, along with sperm that had been activated, and examined the effect of reactive oxygen species (ROS produced by these sperm types upon embryogenesis following bovine in vitro fertilization (IVF and ICSI. Data showed that activated sperm reduced the chromosomal integrity of IVF/ICSI embryos at the blastocyst stage, while capacitated sperm produced ROS in capacitation media. Secondly, we treated sperm with carbonyl cyanide m-chlorophenyl hydrazine (CCCP, a chemical known to uncouple cell respiration within the mitochondria, and investigated the effect of this treatment upon blastocyst formation and chromosomal integrity at the blastocyst stage. Activated sperm in which the mitochondria had been treated with CCCP reduced levels of chromosomal aberration at the blastocyst stage following ICSI, by reducing mitochondrial activity in activated sperm. In conclusion, these findings suggest that capacitated sperm exhibiting activated motility induced chromosomal aberration during development to the blastocyst stage following ICSI. The injection of sperm exhibiting normal motility, or activated sperm in which mitochondrial activity had been reduced, improved the quality of ICSI-derived embryos. Therefore, the selection of sperm exhibiting progressive motility may not always be better for early embryo development and fetal growth following human ICSI, and that the use of a bovine model may contribute to a deeper understanding of sperm selection for human ICSI embryo development.

Low Sperm Count

Science.gov (United States)

... that the fluid (semen) you ejaculate during an orgasm contains fewer sperm than normal. A low sperm ... ejaculation occurs when semen enters the bladder during orgasm instead of emerging out of the tip of ...

Constructing co-Higgs bundles on CP^2

OpenAIRE

Rayan, Steven

2013-01-01

On a complex manifold, a co-Higgs bundle is a holomorphic vector bundle with an endomorphism twisted by the tangent bundle. The notion of generalized holomorphic bundle in Hitchin's generalized geometry coincides with that of co-Higgs bundle when the generalized complex manifold is ordinary complex. Schwarzenberger's rank-2 vector bundle on the projective plane, constructed from a line bundle on the double cover CP^1 \\times CP^1 \\to CP^2, is naturally a co-Higgs bundle, with the twisted endom...

CANFLEX fuel bundle impact test

International Nuclear Information System (INIS)

Chang, Seok Kyu; Chung, C. H.; Park, J. S.; Hong, S. D.; Kim, B. D.

1997-08-01

This document outlines the test results for the impact test of the CANFLEX fuel bundle. Impact test is performed to determine and verify the amount of general bundle shape distortion and defect of the pressure tube that may occur during refuelling. The test specification requires that the fuel bundles and the pressure tube retain their integrities after the impact test under the conservative conditions (10 stationary bundles with 31kg/s flow rate) considering the pressure tube creep. The refuelling simulator operating with pneumatic force and simulated shield plug were fabricated and the velocity/displacement transducer and the high speed camera were also used in this test. The characteristics of the moving bundle (velocity, displacement, impacting force) were measured and analyzed with the impact sensor and the high speed camera system. The important test procedures and measurement results were discussed as follows. 1) Test bundle measurements and the pressure tube inspections 2) Simulated shield plug, outlet flange installation and bundle loading 3) refuelling simulator, inlet flange installation and sensors, high speed camera installation 4) Perform the impact test with operating the refuelling simulator and measure the dynamic characteristics 5) Inspections of the fuel bundles and the pressure tube. (author). 8 refs., 23 tabs., 13 figs

Milk proteins interact with goat Binder of SPerm (BSP) proteins and decrease their binding to sperm.

Science.gov (United States)

de Menezes, Erika Bezerra; van Tilburg, Mauricio; Plante, Geneviève; de Oliveira, Rodrigo V; Moura, Arlindo A; Manjunath, Puttaswamy

2016-11-01

Seminal plasma Binder of SPerm (BSP) proteins bind to sperm at ejaculation and promote capacitation. When in excess, however, BSP proteins damage the sperm membrane. It has been suggested that milk components of semen extenders associate with BSP proteins, potentially protecting sperm. Thus, this study was conducted to investigate if milk proteins interact with BSP proteins and reduce BSP binding to goat sperm. Using gel filtration chromatography, milk was incubated with goat seminal plasma proteins and loaded onto columns with and without calcium. Milk was also fractionated into parts containing mostly whey proteins or mostly caseins, incubated with seminal plasma proteins and subjected to gel filtration. Eluted fractions were evaluated by immunoblot using anti-goat BSP antibodies, confirming milk protein-BSP protein interactions. As determined by ELISA, milk proteins coated on polystyrene wells bound to increasing of goat BSP proteins. Far-western dot blots confirmed that BSP proteins bound to caseins and β-lactoglobulin in a concentration-dependent manner. Then, cauda epididymal sperm from five goats was incubated with seminal plasma; seminal plasma followed by milk; and milk followed by seminal plasma. Sperm membrane proteins were extracted and evaluated by immunoblotting. The pattern of BSP binding to sperm membrane proteins was reduced by 59.3 % when epididymal sperm were incubated with seminal plasma and then with skimmed milk (p  0.05). In conclusion, goat BSP proteins have an affinity for caseins and whey proteins. Milk reduces BSP binding to goat sperm, depending whether or not sperm had been previously exposed to seminal plasma. Such events may explain the protective effect of milk during goat sperm preservation.

Polycation induced actin bundles

OpenAIRE

Muhlrad, Andras; Grintsevich, Elena E.; Reisler, Emil

2011-01-01

Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations an...

Presence and function of dopamine transporter (DAT in stallion sperm: dopamine modulates sperm motility and acrosomal integrity.

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Javier A Urra

Full Text Available Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT, serotonin (SERT and norepinephrine (NET transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylaminostyryl]-N-methylpyridinium iodide (ASP(+, as substrate. In addition, we also showed that dopamine (1 mM treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909 and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility.

Sperm dynamics in spiders (Araneae): ultrastructural analysis of the sperm activation process in the garden spider Argiope bruennichi (Scopoli, 1772).

Science.gov (United States)

Vöcking, Oliver; Uhl, Gabriele; Michalik, Peter

2013-01-01

Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in spiders. Male spiders produce sperm whose cell components are coiled within the sperm cell and that are surrounded by a proteinaceous sheath. These inactive and encapsulated sperm are transferred to the female spermathecae where they are stored for later fertilization. We analyzed the ultrastructural changes of sperm cells during residency time in the female genital system of the orb-web spider Argiope bruennichi. We found three clearly distinguishable sperm conditions: encapsulated sperm (secretion sheath present), decapsulated (secretion sheath absent) and uncoiled sperm (cell components uncoiled, presumably activated). After insemination, sperm remain in the encapsulated condition for several days and become decapsulated after variable periods of time. A variable portion of the decapsulated sperm transforms rapidly to the uncoiled condition resulting in a simultaneous occurrence of decapsulated and uncoiled sperm. After oviposition, only decapsulated and uncoiled sperm are left in the spermathecae, strongly suggesting that the activation process is not reversible. Furthermore, we found four different types of secretion in the spermathecae which might play a role in the decapsulation and activation process.

Real-time wavelet-based inline banknote-in-bundle counting for cut-and-bundle machines

Science.gov (United States)

Petker, Denis; Lohweg, Volker; Gillich, Eugen; Türke, Thomas; Willeke, Harald; Lochmüller, Jens; Schaede, Johannes

2011-03-01

Automatic banknote sheet cut-and-bundle machines are widely used within the scope of banknote production. Beside the cutting-and-bundling, which is a mature technology, image-processing-based quality inspection for this type of machine is attractive. We present in this work a new real-time Touchless Counting and perspective cutting blade quality insurance system, based on a Color-CCD-Camera and a dual-core Computer, for cut-and-bundle applications in banknote production. The system, which applies Wavelet-based multi-scale filtering is able to count banknotes inside a 100-bundle within 200-300 ms depending on the window size.

Evaluation of Single-Bundle versus Double-Bundle PCL Reconstructions with More Than 10-Year Follow-Up

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Masataka Deie

2015-01-01

Full Text Available Background. Posterior cruciate ligament (PCL injuries are not rare in acute knee injuries, and several recent anatomical studies of the PCL and reconstructive surgical techniques have generated improved patient results. Now, we have evaluated PCL reconstructions performed by either the single-bundle or double-bundle technique in a patient group followed up retrospectively for more than 10 years. Methods. PCL reconstructions were conducted using the single-bundle (27 cases or double-bundle (13 cases method from 1999 to 2002. The mean age at surgery was 34 years in the single-bundle group and 32 years in the double-bundle group. The mean follow-up period was 12.5 years. Patients were evaluated by Lysholm scoring, the gravity sag view, and knee arthrometry. Results. The Lysholm score after surgery was 89.1±5.6 points for the single-bundle group and 91.9±4.5 points for the double-bundle group. There was no significant difference between the methods in the side-to-side differences by gravity sag view or knee arthrometer evaluation, although several cases in both groups showed a side-to-side difference exceeding 5 mm by the latter evaluation method. Conclusions. We found no significant difference between single- and double-bundle PCL reconstructions during more than 10 years of follow-up.

An immunological approach of sperm sexing and different methods for identification of X- and Y-chromosome bearing sperm

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Shiv Kumar Yadav

2017-05-01

Full Text Available Separation of X- and Y-chromosome bearing sperm has been practiced for selection of desired sex of offspring to increase the profit in livestock industries. At present, fluorescence-activated cell sorter is the only successful method for separation of X- and Y-chromosome bearing sperm. This technology is based on the differences in DNA content between these two types of sperm and has been commercialized for bovine sperm. However, this technology still has problems in terms of high economic cost, sperm damage, and lower pregnancy rates compared to unsorted semen. Therefore, an inexpensive, convenient, and non-invasive approach for sperm sexing would be of benefit to agricultural sector. Within this perspective, immunological sperm sexing method is one of the attractive choices to separate X- and Y-chromosome bearing sperm. This article reviews the current knowledge about immunological approaches, viz., H-Y antigen, sex-specific antigens, and differentially expressed proteins for sperm sexing. Moreover, this review also highlighted the different methods for identification of X- and Y-sperm.

Confocal fluorescence microscopy in a murine model of microdissection testicular sperm extraction to improve sperm retrieval.

Science.gov (United States)

Smith, Ryan P; Lowe, Greg J; Kavoussi, Parviz K; Steers, William D; Costabile, Raymond A; Herr, John C; Shetty, Jagathpala; Lysiak, Jeffrey J

2012-05-01

Microdissection testicular sperm extraction markedly improves the sperm retrieval rates in men with nonobstructive azoospermia. However, localizing sperm foci can be time-consuming and it is not always successful. Fiberoptic confocal fluorescent microscopy offers the advantage of rapid in vivo detection of fluorescently labeled sperm in the seminiferous tubules. After establishing the feasibility of fiberoptic confocal fluorescent microscopy to identify antibody labeled sperm in vivo C57/B6 mice underwent intraperitoneal injection of busulfan to induce azoospermia. During spermatogenesis reestablishment at approximately 16 weeks the mice were anesthetized and the testes were delivered through a low midline incision. Fluorescein isothiocyanate labeled antibody to intra-acrosomal protein Hs-14 was injected retrograde into a single murine rete testis. The testes were imaged in vivo with fiberoptic confocal fluorescent microscopy and sperm foci were detected. The respective seminiferous tubules were excised and squash prepared for immunofluorescence microscopy. Sperm foci were identified in the testis injected with fluorescently tagged antibody by in vivo fiberoptic confocal fluorescence microscopy. The contralateral control testis of each mouse showed no specific signal. Immunofluorescence microscopy of the excised tubules provided morphological confirmation of the presence of labeled sperm with an absence in controls. Findings were consistent in the feasibility portion of the study and in the busulfan model of nonobstructive azoospermia. Fiberoptic confocal fluorescent microscopy was feasible during microdissection testicular sperm extraction in an azoospermic mouse model to identify fluorescently labeled sperm in vivo. Translation to the clinical setting could decrease operative time and improve the sperm harvest rate. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Sperm DNA fragmentation in boars is delayed or abolished by using sperm extenders.

Science.gov (United States)

Pérez-Llano, Begoña; Enciso, María; García-Casado, Pedro; Sala, Rubén; Gosálvez, Jaime

2006-12-01

The semen quality of seven young adult boars was assessed for percentages of sperm motility, normal acrosomes, abnormal sperm, cells positive to sHOST (short Hipoosmotic Swelling Test), HPNA cells (sHOST Positive with Normal Acrosome cells) and the percentage of sperm heads, which exhibited DNA fragmentation using the Sperm Chromatin Dispersion test (SCD). These parameters were analysed in sperm samples both undiluted and diluted using a commercial extender and stored at 15 degrees C for 21 days. Results showed that semen quality decreases faster in the undiluted semen samples from day 0 to day 7 compared to diluted semen samples that remained with a high quality up to day 11. The undiluted semen exhibited a low DNA fragmentation index (DFI) during the first days and then a significant increase from day 7 up to day 21. This increase in the DFI coincided with the lowest levels of the other semen quality parameters. On the contrary, the samples diluted in the commercial extender showed very low levels of DNA fragmentation in all boars during the preservation period. When the evolution of DNA fragmentation was analysed in the undiluted samples, differences were found among boars. These differences were not shown in the samples diluted in the extender where the basal DFI remained stable during the 21 days. The main conclusion of this study was that some sperm extenders delay or partially prevent sperm DNA fragmentation.

Co-Higgs bundles on P^1

OpenAIRE

Rayan, Steven

2010-01-01

Co-Higgs bundles are Higgs bundles in the sense of Simpson, but with Higgs fields that take values in the tangent bundle instead of the cotangent bundle. Given a vector bundle on P^1, we find necessary and sufficient conditions on its Grothendieck splitting for it to admit a stable Higgs field. We characterize the rank-2, odd-degree moduli space as a universal elliptic curve with a globally-defined equation. For ranks r=2,3,4, we explicitly verify the conjectural Betti numbers emerging from t...

Impact of bundle deformation on CHF: ASSERT-PV assessment of extended burnup Bruce B bundle G85159W

International Nuclear Information System (INIS)

Rao, Y.F.; Manzer, A.M.

2005-01-01

This paper presents a subchannel thermalhydraulic analysis of the effect on critical heat flux (CHF) of bundle deformation such as element bow and diametral creep. The bundle geometry is based on the post-irradiation examination (PIE) data of a single bundle from the Bruce B Nuclear Generating Station, Bruce B bundle G85159W, which was irradiated for more than two years in the core during reactor commissioning. The subchannel code ASSERT-PV IST is used to assess changes in CHF and dryout power due to bundle deformation, compared to the reference, undeformed bundle. (author)

Fluid structure interaction in tube bundles

International Nuclear Information System (INIS)

Brochard, D.; Jedrzejewski, F.; Gibert, R.J.

1995-01-01

A lot of industrial components contain tube bundles immersed in a fluid. The mechanical analysis of such systems requires the study of the fluid structure interaction in the tube bundle. Simplified methods, based on homogenization methods, have been developed to analyse such phenomenon and have been validated through experimental results. Generally, these methods consider only the fluid motion in a plan normal to the bundle axis. This paper will analyse, in a first part, the fluid structure interaction in a tube bundle through a 2D finite element model representing the bundle cross section. The influence of various parameters like the bundle size, and the bundle confinement will be studied. These results will be then compared with results from homogenization methods. Finally, the influence of the 3D fluid motion will be investigated, in using simplified methods. (authors). 11 refs., 12 figs., 2 tabs

Severe Fertility Effects of sheepish Sperm Caused by Failure To Enter Female Sperm Storage Organs in Drosophila melanogaster

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Masatoshi Tomaru

2018-01-01

Full Text Available In Drosophila, mature sperm are transferred from males to females during copulation, stored in the sperm storage organs of females, and then utilized for fertilization. Here, we report a gene named sheepish (shps of Drosophila melanogaster that is essential for sperm storage in females. shps mutant males, although producing morphologically normal and motile sperm that are effectively transferred to females, produce very few offspring. Direct counts of sperm indicated that the primary defect was correlated to failure of shps sperm to migrate into the female sperm storage organs. Increased sperm motion parameters were seen in the control after transfer to females, whereas sperm from shps males have characteristics of the motion parameters different from the control. The few sperm that occasionally entered the female sperm storage organs showed no obvious defects in fertilization and early embryo development. The female postmating responses after copulation with shps males appeared normal, at least with respect to conformational changes of uterus, mating plug formation, and female remating rates. The shps gene encodes a protein with homology to amine oxidases, including as observed in mammals, with a transmembrane region at the C-terminal end. The shps mutation was characterized by a nonsense replacement in the third exon of CG13611, and shps was rescued by transformants of the wild-type copy of CG13611. Thus, shps may define a new class of gene responsible for sperm storage.

Entropy for frame bundle systems and Grassmann bundle systems induced by a diffeomorphism

Institute of Scientific and Technical Information of China (English)

SUN; Weniang(孙文祥)

2002-01-01

ALiao hyperbolic diffeomorphism has equal measure entropy and topological entropy to that ofits induced systems on frame bundles and Grassmann bundles. This solves a problem Liao posed in 1996 forLiao hyperbolic diffeomorphisms.

Sperm-macrophage interaction in the mouse: a quantitative assay in vitro using 111indium oxine-labeled sperm

International Nuclear Information System (INIS)

Olive, D.L.; Weinberg, J.B.; Haney, A.F.

1987-01-01

The role of reproductive tract macrophages in contraception and reproductive failure has become widely recognized. However, in vitro analysis of sperm phagocytosis by macrophages has relied upon a semi-quantitative method of sperm counting that is of limited accuracy and reproducibility. We have developed an assay using murine sperm labeled with 111 indium oxine, and results indicate the labeling to be rapid and efficient. Incorporation of 111 indium into sperm increased the dose and sperm concentration and reached 90% maximal uptake after 15 min incubation, with maximal uptake occurring at 30 min. No decrease in sperm motility was noted with levels of oxine in excess of those required for significant labeling. Maximal labeling efficiency occurred in phosphate-buffered saline (PBS), with Dulbecco's modified Eagle's medium (DMEM) + 10% adult bovine serum (ABS) producing significantly less uptake. Label dissociation was detectable in PBS at room temperature, but at 37 degrees C in DMEM + 10% ABS, loss of label occurred at a rate of 23.5%/h. Addition of labeled sperm to murine macrophage monolayers under optimal conditions resulted in uptake of 111 indium by macrophages, while free label was unincorporated. Results indicated assay specificity for macrophage-limited uptake, with insignificant label uptake by nonphagocytic murine fibroblasts and better sensitivity than sperm counting. Macrophages from Bacillus Calmette-Guerin (BCG)-infected mice resulted in a decrease in sperm uptake. Female macrophages showed greater capacity for sperm uptake than those of the male mouse. These initial studies demonstrated the utility of this model system in enhancing the understanding of sperm-macrophage interaction in the female reproductive tract

Sperm origins and concentration do not impact the clinical outcomes in intracytoplasmic sperm injection cycles.

Science.gov (United States)

Yang, Cen; Zhou, Ze-Hong; Zheng, Dan-Ni; Xu, Xiao-Fei; Huang, Jin; Lian, Ying; Qiao, Jie

2018-05-25

In the present study, we evaluated the impact of sperm origins and concentration on the clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles. A total of 1201 ICSI cycles were retrospectively analyzed for male azoospermia or oligozoospermia between January 2015 and December 2015 in the Peking University Third Hospital. Patients were divided into three groups (Group 1 vs Group 2/3; surgically extracted sperm vs ejaculated sperms): Group 1 included 343 ICSI cycles and Group 2 analyzed 388 cycles on semen with sperm concentration cycles with sperm concentration between 5 × 10 6 ml -1 and 15 × 10 6 ml -1 (mild oligozoospermia group). Fertilization rates, clinical pregnancy rates, and live birth rates were analyzed and compared among groups of different semen origins and concentrations on the oocyte retrieval day. Group 2 showed a lower fertilization rate than Group 3 (62.9% ± 21.6% vs 66.8% ± 22.1%,Pcycles.

Analysis of sperm quality in recombinant inbred mouse strains: correlation of sperm head shape with sperm abnormalities and with the incidence of supplementary spermatozoa in the perivitelline space.

Science.gov (United States)

Krzanowska, H; Styrna, J; Wabik-Sliz, B

1995-07-01

Recombinant inbred strains were developed from reciprocal crosses between two inbred strains of mice (CBA and KE) differing in sperm head shape, proportion of normal sperm heads (CBA, 95%; KE, 78%) and fertilization efficiency (CBA, 100% of fertilized ova; KE, 72%), to determine whether the indices of sperm morphology and function were correlated. The following parameters were analysed in recombinant inbred and progenitor strains: index of sperm head shape (head width in the middle of its length/head length), percentage of abnormal sperm heads, percentage of spermatozoa with progressive movements, efficiency of penetration of hyaluronic acid polymer (Sperm Select) and percentage of fertilized ova after mating males from the tested strains with females from an outbred stock. For each investigated character, recombinant inbred strains, recombinant inbred EXCB and CBXE, could be divided into at least three categories: KE-like, CBA-like and intermediate, suggesting that in each case a minimum of two genes was involved. Recombinant strains derived from the reciprocal crosses of progenitor strains differed only with respect to the proportion of abnormal sperm heads, showing the involvement of the Y chromosome in determining this character. Penetration into Sperm Select was significantly correlated both with fertilization efficiency and sperm motility, while correlation with the proportion of normal spermatozoa did not reach the level of significance. However, there was a significant negative correlation of both sperm abnormalities and the incidence of supplementary spermatozoa in the perivitelline space with the index of sperm head shape.(ABSTRACT TRUNCATED AT 250 WORDS)

Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.

Science.gov (United States)

Campbell, Anna L; Ellis, Robert P; Urbina, Mauricio A; Mourabit, Sulayman; Galloway, Tamara S; Lewis, Ceri

2017-08-01

The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pH NBS 7.77, 1000 μatm pCO 2 ). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sperm competition in bats.

OpenAIRE

Hosken, D J

1997-01-01

Sperm competition is a widespread phenomenon influencing the evolution of male anatomy, physiology and behaviour. Bats are an ideal group for studying sperm competition. Females store fertile sperm for up to 200 days and the size of social groups varies from single animals to groups of hundreds of thousands. This study examines the relationship between social group size and investment in spermatogenesis across 31 species of microchiropteran bat using new and published data on testis mass and ...

Signal detection by active, noisy hair bundles

Science.gov (United States)

O'Maoiléidigh, Dáibhid; Salvi, Joshua D.; Hudspeth, A. J.

2018-05-01

Vertebrate ears employ hair bundles to transduce mechanical movements into electrical signals, but their performance is limited by noise. Hair bundles are substantially more sensitive to periodic stimulation when they are mechanically active, however, than when they are passive. We developed a model of active hair-bundle mechanics that predicts the conditions under which a bundle is most sensitive to periodic stimulation. The model relies only on the existence of mechanotransduction channels and an active adaptation mechanism that recloses the channels. For a frequency-detuned stimulus, a noisy hair bundle's phase-locked response and degree of entrainment as well as its detection bandwidth are maximized when the bundle exhibits low-amplitude spontaneous oscillations. The phase-locked response and entrainment of a bundle are predicted to peak as functions of the noise level. We confirmed several of these predictions experimentally by periodically forcing hair bundles held near the onset of self-oscillation. A hair bundle's active process amplifies the stimulus preferentially over the noise, allowing the bundle to detect periodic forces less than 1 pN in amplitude. Moreover, the addition of noise can improve a bundle's ability to detect the stimulus. Although, mechanical activity has not yet been observed in mammalian hair bundles, a related model predicts that active but quiescent bundles can oscillate spontaneously when they are loaded by a sufficiently massive object such as the tectorial membrane. Overall, this work indicates that auditory systems rely on active elements, composed of hair cells and their mechanical environment, that operate on the brink of self-oscillation.

Bundled payment fails to gain a foothold In California: the experience of the IHA bundled payment demonstration.

Science.gov (United States)

Ridgely, M Susan; de Vries, David; Bozic, Kevin J; Hussey, Peter S

2014-08-01

To determine whether bundled payment could be an effective payment model for California, the Integrated Healthcare Association convened a group of stakeholders (health plans, hospitals, ambulatory surgery centers, physician organizations, and vendors) to develop, through a consensus process, the methods and means of implementing bundled payment. In spite of a high level of enthusiasm and effort, the pilot did not succeed in its goal to implement bundled payment for orthopedic procedures across multiple payers and hospital-physician partners. An evaluation of the pilot documented a number of barriers, such as administrative burden, state regulatory uncertainty, and disagreements about bundle definition and assumption of risk. Ultimately, few contracts were signed, which resulted in insufficient volume to test hypotheses about the impact of bundled payment on quality and costs. Although bundled payment failed to gain a foothold in California, the evaluation provides lessons for future bundled payment initiatives. Project HOPE—The People-to-People Health Foundation, Inc.

Molybdenum-99-producing 37-element fuel bundle neutronically and thermal-hydraulically equivalent to a standard CANDU fuel bundle

Energy Technology Data Exchange (ETDEWEB)

Nichita, E., E-mail: Eleodor.Nichita@uoit.ca; Haroon, J., E-mail: Jawad.Haroon@uoit.ca

2016-10-15

Highlights: • A 37-element fuel bundle modified for {sup 99}Mo production in CANDU reactors is presented. • The modified bundle is neutronically and thermal-hydraulically equivalent to the standard bundle. • The modified bundle satisfies all safety criteria satisfied by the standard bundle. - Abstract: {sup 99m}Tc, the most commonly used radioisotope in diagnostic nuclear medicine, results from the radioactive decay of {sup 99}Mo which is currently being produced at various research reactors around the globe. In this study, the potential use of CANDU power reactors for the production of {sup 99}Mo is investigated. A modified 37-element fuel bundle, suitable for the production of {sup 99}Mo in existing CANDU-type reactors is proposed. The new bundle is specifically designed to be neutronically and thermal-hydraulically equivalent to the standard 37-element CANDU fuel bundle in normal, steady-state operation and, at the same time, be able to produce significant quantities of {sup 99}Mo when irradiated in a CANDU reactor. The proposed bundle design uses fuel pins consisting of a depleted-uranium centre surrounded by a thin layer of low-enriched uranium. The new molybdenum-producing bundle is analyzed using the lattice transport code DRAGON and the diffusion code DONJON. The proposed design is shown to produce 4081 six-day Curies of {sup 99}Mo activity per bundle when irradiated in the peak-power channel of a CANDU core, while maintaining the necessary reactivity and power rating limits. The calculated {sup 99}Mo yield corresponds to approximately one third of the world weekly demand. A production rate of ∼3 bundles per week can meet the global demand of {sup 99}Mo.

Sperm motility of externally fertilizing fish and amphibians.

Science.gov (United States)

Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

2015-01-01

We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P amphibian sperm in general and anurans reversion from internal to external fertilization. Our findings provide a greater understanding of the reproductive biology of externally fertilizing fish and amphibians, and a biological foundation for the further development of reproduction technologies for their sustainable management.

Sperm Impairment by Sperm Agglutinating Factor Isolated from Escherichia coli: Receptor Specific Interactions

Directory of Open Access Journals (Sweden)

Kiranjeet Kaur

2013-01-01

Full Text Available In an earlier work done in our laboratory, we have been able to isolate a sperm agglutinating strain of Escherichia coli from the semen sample of a male attending infertility clinic. Further, factor responsible for sperm agglutination (SAF was isolated and purified, and, using SAF as a tool, corresponding SAF binding receptor from human spermatozoa has been purified. Characterization of SAF and SAF binding receptor using MALDI-TOF showed homology to glutamate decarboxylase and MHC class I molecule, respectively. Coincubation of SAF with spermatozoa not only resulted in spermagglutination but could also compromise other sperm parameters, namely, Mg2+ dependent ATPase activity and apoptosis. Intravaginal administration of SAF could lead to infertility in Balb/c mice. SAF induced impairment of sperm parameters, and infertility was observed to be due to interaction of SAF with sperm surface receptor component as, when purified receptor was introduced, receptor completely inhibited all the detrimental effects induced by SAF. From these results, it could be concluded that interaction of SAF with spermatozoa is receptor mediated.

Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

Energy Technology Data Exchange (ETDEWEB)

Kaipainen, H; Seppaenen, V; Rinne, S

1997-12-31

The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

Energy Technology Data Exchange (ETDEWEB)

Kaipainen, H.; Seppaenen, V.; Rinne, S.

1996-12-31

The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

SMART USE OF COMPUTER-AIDED SPERM ANALYSIS (CASA) TO CHARACTERIZE SPERM MOTION

Science.gov (United States)

Computer-aided sperm analysis (CASA) has evolved over the past fifteen years to provide an objective, practical means of measuring and characterizing the velocity and parttern of sperm motion. CASA instruments use video frame-grabber boards to capture multiple images of spermato...

Vibration of fuel bundles

International Nuclear Information System (INIS)

Chen, S.S.

1975-06-01

Several mathematical models have been proposed for calculating fuel rod responses in axial flows based on a single rod consideration. The spacing between fuel rods in liquid metal fast breeder reactors is small; hence fuel rods will interact with one another due to fluid coupling. The objective of this paper is to study the coupled vibration of fuel bundles. To account for the fluid coupling, a computer code, AMASS, is developed to calculate added mass coefficients for a group of circular cylinders based on the potential flow theory. The equations of motion for rod bundles are then derived including hydrodynamic forces, drag forces, fluid pressure, gravity effect, axial tension, and damping. Based on the equations, a method of analysis is presented to study the free and forced vibrations of rod bundles. Finally, the method is applied to a typical LMFBR fuel bundle consisting of seven rods

Comparison of semen variables, sperm DNA damage and sperm membrane proteins in two male layer breeder lines.

Science.gov (United States)

M, Shanmugam; T R, Kannaki; A, Vinoth

2016-09-01

Semen variables are affected by the breed and strain of chicken. The present study was undertaken to compare the semen quality in two lines of adult chickens with particular reference to sperm chromatin condensation, sperm DNA damage and sperm membrane proteins. Semen from a PD3 and White Leghorn control line was collected at 46 and 47 weeks and 55 weeks of age. The semen was evaluated for gross variables and sperm chromatin condensation by aniline blue staining. Sperm DNA damage was assessed by using the comet assay at 47 weeks of age and sperm membrane proteins were assessed at 55 weeks of age. The duration of fertility was studied by inseminating 100 million sperm once into the hens of the same line as well as another line. The eggs were collected after insemination for 15days and incubated. The eggs were candled on 18th day of incubation for observing embryonic development. The White Leghorn control line had a greater sperm concentration and lesser percentage of morphologically abnormal sperm at the different ages where assessments occurred. There was no difference in sperm chromatin condensation, DNA damage and membrane proteins between the lines. Only low molecular weight protein bands of less than 95kDa were observed in samples of both lines. The line from which semen was used had no effect on the duration over which fertility was sustained after insemination either when used in the same line or another line. Thus, from the results of the present study it may be concluded that there was a difference in gross semen variables between the lines that were studied, however, the sperm chromatin condensation, DNA damage, membrane proteins and duration over which fertility was sustained after insemination did not differ between the lines. Copyright © 2016 Elsevier B.V. All rights reserved.

Ocean acidification impacts on sperm mitochondrial membrane potential bring sperm swimming behaviour near its tipping point.

Science.gov (United States)

Schlegel, Peter; Binet, Monique T; Havenhand, Jonathan N; Doyle, Christopher J; Williamson, Jane E

2015-04-01

Broadcast spawning marine invertebrates are susceptible to environmental stressors such as climate change, as their reproduction depends on the successful meeting and fertilization of gametes in the water column. Under near-future scenarios of ocean acidification, the swimming behaviour of marine invertebrate sperm is altered. We tested whether this was due to changes in sperm mitochondrial activity by investigating the effects of ocean acidification on sperm metabolism and swimming behaviour in the sea urchin Centrostephanus rodgersii. We used a fluorescent molecular probe (JC-1) and flow cytometry to visualize mitochondrial activity (measured as change in mitochondrial membrane potential, MMP). Sperm MMP was significantly reduced in ΔpH -0.3 (35% reduction) and ΔpH -0.5 (48% reduction) treatments, whereas sperm swimming behaviour was less sensitive with only slight changes (up to 11% decrease) observed overall. There was significant inter-individual variability in responses of sperm swimming behaviour and MMP to acidified seawater. We suggest it is likely that sperm exposed to these changes in pH are close to their tipping point in terms of physiological tolerance to acidity. Importantly, substantial inter-individual variation in responses of sperm swimming to ocean acidification may increase the scope for selection of resilient phenotypes, which, if heritable, could provide a basis for adaptation to future ocean acidification. © 2015. Published by The Company of Biologists Ltd.

Sperm quality but not relatedness predicts sperm competition success in threespine sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Mehlis, Marion; Rahn, Anna K; Bakker, Theo C M

2015-04-26

Mating between close relatives often leads to a reduction of an individual's fitness, due to an increased expression of deleterious alleles. Thus, in many animal taxa pre- as well as postcopulatory inbreeding avoidance mechanisms have evolved. An increased risk of inbreeding and hence a loss of genetic variation may occur during founder events as in most cases only few individuals establish a new population. The threespine stickleback (Gasterosteus aculeatus) is a small externally fertilizing fish species subject to strong sperm competition. Sticklebacks inhabit both marine and freshwater environments and anadromous populations have repeatedly established new genetically less diverse freshwater populations. Previous studies showed that anadromous sticklebacks strongly suffer from inbreeding depression and when given the choice females prefer to mate with unrelated males. The present study aimed to address whether there exists a postcopulatory inbreeding avoidance mechanism solely based on sperm-egg interactions in sperm competition experiments. We used F1 individuals that originated either from a large, genetically heterogeneous anadromous population or from a small, genetically less diverse freshwater population. For each population, eggs of two different females were in vitro fertilized by the same two males' sperm in a paired study design. In the main experiment one male was the female's full-sib brother and in the control experiment all individuals were unrelated. The results revealed that fertilization success was independent of relatedness in both populations suggesting a general lack of a postcopulatory inbreeding avoidance mechanism. Instead, male quality (i.e. sperm morphology) predicted paternity success during competitive fertilization trials. In sticklebacks, there is no evidence for postcopulatory inbreeding avoidance. Sperm morphology predicted paternity instead, thus sperm quality traits are under strong sexual selection, presumably driven by the

Sperm quality after swim up and density gradient centrifugation sperm preparation with supplementation of alpha lipoic acid (ALA): A preliminary study

Science.gov (United States)

Lestari, Silvia W.; Lestari, Sarah H.; Pujianto, Dwi A.

2018-02-01

Intra uterine insemination (IUI) as one of the treatment for infertility, persists low success rate. A factor that contributes to the unsuccessful of IUI is sperm preparation, performed through Swim-up (SU) and Density Gradient Centrifugation (DGC) methods. Furthermore, studies have shown that Alpha Lipoic Acid (ALA) is a potent antioxidant that could enhance the sperm motility and protect the DNA integrity of the sperm [1]. This study is aimed to re-evaluate the efficiency of the DGC and SU methods in selecting sperm before being transferred for IUI by the supplementation of ALA based on the sperm DNA integrity. Semen samples were obtained from 13 men from partners of women who are infertile (normozoospermia) and underwent IUI. Semen analysis based on the guideline of World Health Organization (WHO) 2010 was performed to measure the sperm motility and velocity, before and after sperm preparation. Then, samples were incubated with Alpha Lipoic Acid (ALA) in 0.625 mg (ALA 1), 1.25 mg (ALA 2) and 2.5 mg (ALA 3). The Sperm Chromatin Dispersion (SCD) test was performed to evaluate the sperm DNA Fragmentation Index (DFI). The percentage of motile sperm was higher in prepared sperm (post-DGC and post-SU) than in whole semen. Furthermore, the percentage of motile sperm was higher in post-DGC compared to post-SU. The level of DFI after the supplementation of ALA was decreased in prepared sperm compared to the whole semen. ALA was proved capable to select the better sperm quality with decreased sperm DNA fragmentation of prepared sperm in the all of DFI category.

Principal noncommutative torus bundles

DEFF Research Database (Denmark)

Echterhoff, Siegfried; Nest, Ryszard; Oyono-Oyono, Herve

2008-01-01

of bivariant K-theory (denoted RKK-theory) due to Kasparov. Using earlier results of Echterhoff and Williams, we shall give a complete classification of principal non-commutative torus bundles up to equivariant Morita equivalence. We then study these bundles as topological fibrations (forgetting the group...

Boiling heat transfer on horizontal tube bundles

International Nuclear Information System (INIS)

Anon.

1987-01-01

Nucleate boiling heat transfer characteristics for a tube in a bundle differ from that for a single tube in a pool and this difference is known as 'tube bundle effect.' There exist two bundle effects, positive and negative. The positive bundle effect enhances heat transfer due to convective flow induced by rising bubbles generated from the lower tubes, while the negative bundle effect deteriorates heat transfer due to vapor blanketing caused by accumulation of bubbles. Staggered tube bundles tested and found that the upper tubes in bundles have higher heat transfer coefficients than the lower tubes. The effects of various parameters such as pressure, tube geometry and oil contamination on heat transfer have been examined. Some workers attempted to clarify the mechanism of occurrence of 'bundle effect' by testing tube arrangements of small scale. All reported only enhancement in heat transfer but results showed the symptom of heat transfer deterioration at higher heat fluxes. As mentioned above, it has not been clarified so far even whether the 'tube bundle effect' should serve as enhancement or deterioration of heat transfer in nucleate boiling. In this study, experiments are performed in detail by using bundles of small scale, and effects of heat flux distribution, pressure and tube location are clarified. Furthermore, some consideration on the mechanisms of occurrence of 'tube bundle effect' is made and a method for prediction of heat transfer rate is proposed

Varicocele Negatively Affects Sperm Mitochondrial Respiration.

Science.gov (United States)

Ferramosca, Alessandra; Albani, Denise; Coppola, Lamberto; Zara, Vincenzo

2015-10-01

To evaluate the effect of varicocele on oxidative stress, sperm mitochondrial respiratory efficiency, sperm morphology, and semen parameters. A total of 20 patients with varicocele and 20 normozoospermic subjects without varicocele (control group) were recruited from a medical center for reproductive biology. The levels of serum reactive oxygen metabolites and seminal lipid peroxides were assessed for both control and varicocele subjects. Sperm deoxyribonucleic acid fragmentation was measured by sperm chromatin dispersion test. Mitochondrial respiratory activity was evaluated with a polarographic assay of oxygen consumption carried out in hypotonically treated sperm cells. In this study, varicocele patients were compared with men without varicoceles. Oxidative stress was observed in the serum and seminal fluid of varicocele patients. These patients showed an increase of 59% (P <.05) in serum reactive oxygen metabolites and a 3-fold increase in the level of sperm lipid peroxides. A parallel and significant increase (a 2-fold increase; P <.05) in the degree of sperm deoxyribonucleic acid fragmentation was also observed. Varicocele patients showed a 27% decrease (P <.05) in mitochondrial respiratory activity in comparison to the control group. A 32% increase (P <.05) in sperm midpiece defects and a 41% decrease (P <.05) in sperm concentration and motility were also observed. Men with varicocele have increased markers of oxidative stress and decreased mitochondrial respiratory activity. These results correlated with abnormalities in semen parameters. For morphology, these correlated with midpiece defects. Copyright © 2015 Elsevier Inc. All rights reserved.

Hypercholesterolemia Impaired Sperm Functionality in Rabbits

Science.gov (United States)

Monclus, Maria A.; Cabrillana, Maria E.; Clementi, Marisa A.; Espínola, Leandro S.; Cid Barría, Jose L.; Vincenti, Amanda E.; Santi, Analia G.; Fornés, Miguel W.

2010-01-01

Hypercholesterolemia represents a high risk factor for frequent diseases and it has also been associated with poor semen quality that may lead to male infertility. The aim of this study was to analyze semen and sperm function in diet-induced hypercholesterolemic rabbits. Twelve adult White New Zealand male rabbits were fed ad libitum a control diet or a diet supplemented with 0.05% cholesterol. Rabbits under cholesterol-enriched diet significantly increased total cholesterol level in the serum. Semen examination revealed a significant reduction in semen volume and sperm motility in hypercholesterolemic rabbits (HCR). Sperm cell morphology was seriously affected, displaying primarily a “folded head”-head fold along the major axe-, and the presence of cytoplasmic droplet on sperm flagellum. Cholesterol was particularly increased in acrosomal region when detected by filipin probe. The rise in cholesterol concentration in sperm cells was determined quantitatively by Gas chromatographic-mass spectrometric analyses. We also found a reduction of protein tyrosine phosphorylation in sperm incubated under capacitating conditions from HCR. Interestingly, the addition of Protein Kinase A pathway activators -dibutyryl-cyclic AMP and iso-butylmethylxanthine- to the medium restored sperm capacitation. Finally, it was also reported a significant decrease in the percentage of reacted sperm in the presence of progesterone. In conclusion, our data showed that diet-induced hypercholesterolemia adversely affects semen quality and sperm motility, capacitation and acrosomal reaction in rabbits; probably due to an increase in cellular cholesterol content that alters membrane related events. PMID:20976152

Microfluidic single sperm entrapment and analysis

NARCIS (Netherlands)

de Wagenaar, B.; Berendsen, Johanna Theodora Wilhelmina; Berendsen, J.T.W.; Bomer, Johan G.; Olthuis, Wouter; van den Berg, Albert; Segerink, Loes Irene

2015-01-01

Selection of healthy spermatozoa is of crucial importance for the success rates of assisted reproduction technologies (ART) such as in vitro fertilization and intra-cytoplasmic sperm injection. Although sperm selection for ART procedures is predominantly based on sperm motility, successful

Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm

Directory of Open Access Journals (Sweden)

Thais Rose dos Santos Hamilton

2016-01-01

Full Text Available Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm.

Cotangent bundle approach to noninertial frames

International Nuclear Information System (INIS)

DeFacio, B.; Retzloff, D.

1980-01-01

The most general possible noninertial acceleration in special relativity is formulated with differential forms in the cotangent bundle. We show that the Lie derivative plays the same role in the cotangent bundle that the covariant derivative plays in the tangent bundle. We also show that a cotangent bundle analog of Fermi--Walker transport can be based upon the, ''cotangent-geodesic'' equation, L/sub u/ω=0. This gives a generalization of the work by Kiehn on classical Hamiltonian mechanics to special relativity

Immature germ cells in semen - correlation with total sperm count and sperm motility.

Science.gov (United States)

Patil, Priya S; Humbarwadi, Rajendra S; Patil, Ashalata D; Gune, Anita R

2013-07-01

Current data regarding infertility suggests that male factor contributes up to 30% of the total cases of infertility. Semen analysis reveals the presence of spermatozoa as well as a number of non-sperm cells, presently being mentioned in routine semen report as "round cells" without further differentiating them into leucocytes or immature germ cells. The aim of this work was to study a simple, cost-effective, and convenient method for differentiating the round cells in semen into immature germ cells and leucocytes and correlating them with total sperm counts and motility. Semen samples from 120 males, who had come for investigation for infertility, were collected, semen parameters recorded, and stained smears studied for different round cells. Statistical analysis of the data was done to correlate total sperm counts and sperm motility with the occurrence of immature germ cells and leucocytes. The average shedding of immature germ cells in different groups with normal and low sperm counts was compared. The clinical significance of "round cells" in semen and their differentiation into leucocytes and immature germ cells are discussed. Round cells in semen can be differentiated into immature germ cells and leucocytes using simple staining methods. The differential counts mentioned in a semen report give valuable and clinically relevant information. In this study, we observed a negative correlation between total count and immature germ cells, as well as sperm motility and shedding of immature germ cells. The latter was statistically significant with a P value 0.000.

Experimental evolution of sperm competitiveness in a mammal

Directory of Open Access Journals (Sweden)

Simmons Leigh W

2011-01-01

Full Text Available Abstract Background When females mate with multiple partners, sperm from rival males compete to fertilise the ova. Studies of experimental evolution have proven the selective action of sperm competition on male reproductive traits. However, while reproductive traits may evolve in response to sperm competition, this does not necessarily provide evidence that sperm competitive ability responds to selection. Indeed, a study of Drosophila failed to observe divergence in sperm competitive ability of males in lines selected for enhanced sperm offence and defence. Results Adopting the naturally polygamous house mouse (Mus domesticus as our vertebrate model, we performed an experimental evolution study and observed genetic divergence in sperm quality; males from the polygamous selection lines produced ejaculates with increased sperm numbers and greater sperm motility compared to males from the monogamous lines. Here, after 12 generations of experimental evolution, we conducted competitive matings between males from lineages evolving under sperm competition and males from lineages subject to relaxed selection. We reduced variation in paternity arising from embryo mortality by genotyping embryos in utero at 14 days gestation. Our microsatellite data revealed a significant paternity bias toward males that evolved under the selective regime of sperm competition. Conclusion We provide evidence that the sperm competitiveness phenotype can respond to selection, and show that improved sperm quality translates to greater competitive fertilisation success in house mice.

Sperm-Hybrid Micromotor for Targeted Drug Delivery.

Science.gov (United States)

Xu, Haifeng; Medina-Sánchez, Mariana; Magdanz, Veronika; Schwarz, Lukas; Hebenstreit, Franziska; Schmidt, Oliver G

2018-01-23

A sperm-driven micromotor is presented as a targeted drug delivery system, which is appealing to potentially treat diseases in the female reproductive tract. This system is demonstrated to be an efficient drug delivery vehicle by first loading a motile sperm cell with an anticancer drug (doxorubicin hydrochloride), guiding it magnetically, to an in vitro cultured tumor spheroid, and finally freeing the sperm cell to deliver the drug locally. The sperm release mechanism is designed to liberate the sperm when the biohybrid micromotor hits the tumor walls, allowing it to swim into the tumor and deliver the drug through the sperm-cancer cell membrane fusion. In our experiments, the sperm cells exhibited a high drug encapsulation capability and drug carrying stability, conveniently minimizing  toxic side effects and unwanted drug accumulation in healthy tissues. Overall, sperm cells are excellent candidates to operate in physiological environments, as they neither express pathogenic proteins nor proliferate to form undesirable colonies, unlike other cells or microorganisms. This sperm-hybrid micromotor is a biocompatible platform with potential application in gynecological healthcare, treating or detecting cancer or other diseases in the female reproductive system.

Boundaries of Ethics, Sperm on the Border –The Globalization of Danish Sperm

DEFF Research Database (Denmark)

Willum Adrian, Stine

as sperm donation in parliamentary debates, and in the media, often raises ethical questions. This presentation inquires into how the bending of boundaries by “inappropriate parents”, fertility travelers, private sperm banks and fertility clinics have been part in negotiating the changes of the legislation......’s situational analysis based on Anselm Strauss’ social world arena theory. Furthermore, I draw theoretically on Karen Barad and Donna Haraway’s notion of diffractive readings. I use their understanding of accountability to question and intervene in the doing of ethics in practice......., relatedness and family by politicians and bioethicists, in the parliament and in the media. I will argue that the globalization of Danish sperm is a story of combined subversive acts by women and men using the technologies, sperm banks and private fertility clinics. I will explore what the labeling...

Predictive value of sperm morphology and progressively motile sperm count for pregnancy outcomes in intrauterine insemination.

Science.gov (United States)

Lemmens, Louise; Kos, Snjezana; Beijer, Cornelis; Brinkman, Jacoline W; van der Horst, Frans A L; van den Hoven, Leonie; Kieslinger, Dorit C; van Trooyen-van Vrouwerff, Netty J; Wolthuis, Albert; Hendriks, Jan C M; Wetzels, Alex M M

2016-06-01

To investigate the value of sperm parameters to predict an ongoing pregnancy outcome in couples treated with intrauterine insemination (IUI), during a methodologically stable period of time. Retrospective, observational study with logistic regression analyses. University hospital. A total of 1,166 couples visiting the fertility laboratory for their first IUI episode, including 4,251 IUI cycles. None. Sperm morphology, total progressively motile sperm count (TPMSC), and number of inseminated progressively motile spermatozoa (NIPMS); odds ratios (ORs) of the sperm parameters after the first IUI cycle and the first finished IUI episode; discriminatory accuracy of the multivariable model. None of the sperm parameters was of predictive value for pregnancy after the first IUI cycle. In the first finished IUI episode, a positive relationship was found for ≤4% of morphologically normal spermatozoa (OR 1.39) and a moderate NIPMS (5-10 million; OR 1.73). Low NIPMS showed a negative relation (≤1 million; OR 0.42). The TPMSC had no predictive value. The multivariable model (i.e., sperm morphology, NIPMS, female age, male age, and the number of cycles in the episode) had a moderate discriminatory accuracy (area under the curve 0.73). Intrauterine insemination is especially relevant for couples with moderate male factor infertility (sperm morphology ≤4%, NIPMS 5-10 million). In the multivariable model, however, the predictive power of these sperm parameters is rather low. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

SPERM COUNT DISTRIBUTIONS IN FERTILE MEN

Science.gov (United States)

Sperm concentration and count are often used as indicators of environmental impacts on male reproductive health. Existing clinical databases may be biased towards subfertile men with low sperm counts and less is known about expected sperm count distributions in cohorts of fertil...

Influence of Bundle Diameter and Attachment Point on Kinematic Behavior in Double Bundle Anterior Cruciate Ligament Reconstruction Using Computational Model

Directory of Open Access Journals (Sweden)

Oh Soo Kwon

2014-01-01

Full Text Available A protocol to choose the graft diameter attachment point of each bundle has not yet been determined since they are usually dependent on a surgeon’s preference. Therefore, the influence of bundle diameters and attachment points on the kinematics of the knee joint needs to be quantitatively analyzed. A three-dimensional knee model was reconstructed with computed tomography images of a 26-year-old man. Based on the model, models of double bundle anterior cruciate ligament (ACL reconstruction were developed. The anterior tibial translations for the anterior drawer test and the internal tibial rotation for the pivot shift test were investigated according to variation of bundle diameters and attachment points. For the model in this study, the knee kinematics after the double bundle ACL reconstruction were dependent on the attachment point and not much influenced by the bundle diameter although larger sized anterior-medial bundles provided increased stability in the knee joint. Therefore, in the clinical setting, the bundle attachment point needs to be considered prior to the bundle diameter, and the current selection method of graft diameters for both bundles appears justified.

Relationship of Total Motile Sperm Count and Percentage Motile Sperm to Successful Pregnancy Rates Following Intrauterine Insemination

OpenAIRE

Pasqualotto, Eleonora B.; Daitch, James A.; Hendin, Benjamin N.; Falcone, Tommaso; Thomas, Anthony J.; Nelson, David R.; Agarwal, Ashok

1999-01-01

Purpose:This study sought (i) to investigate the relationship between postwash total motile sperm count and postwash percentage motile sperm in predicting successful intrauterine insemination and (ii) to determine the minimal postwash total motile sperm count required to achieve pregnancy with intrauterine insemination.

Mass spectrometry profiling of oxysterols in human sperm identifies 25-hydroxycholesterol as a marker of sperm function

Directory of Open Access Journals (Sweden)

Chiara Zerbinati

2017-04-01

Full Text Available Cholesterol is a main lipid component of sperm cell that is essential for sperm membrane fluidity, capacitation, and acrosomal reaction. Recent data obtained in bovine sperm showed that sperm capacitation is associated to the formation of oxysterols, oxidized products of cholesterol. The aim of this study was to profile oxysterol content in human semen, and to investigate their potential role in sperm pathophysiology. Among the 12 oxysterols analyzed, 25-hydroxycholesterol (25-HC resulted the most represented in normozoospermic samples, and its concentration positively correlated with spermatozoa number. We detected Cholesterol 25-hydroxylase, the enzyme responsible for 25-HC production, in human spermatozoa at the level of the neck and the post acrosomal area. Upon incubation with spermatozoa, 25-HC induced calcium and cholesterol transients in connection with the acrosomal reaction. Our results support a role for 25-HC in sperm function.

Pulmonary exposure to carbonaceous nanomaterials and sperm quality

DEFF Research Database (Denmark)

Skovmand, Astrid; Lauvas, Anna Jacobsen; Christensen, Preben

2018-01-01

. Pulmonary inflammation was determined by differential cell count in bronchoalveolar lavage fluid. Epididymal sperm concentration and motility were measured by computer-assisted sperm analysis. Epididymal sperm viability and morphological abnormalities were assessed manually using Hoechst 33,342/PI...... inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model.Methods: Effects on sperm quality after pulmonary inflammation induced by carbonaceous...... flourescent and Spermac staining, respectively. Epididymal sperm were assessed with regard to sperm DNA integrity (damage). Daily sperm production was measured in the testis, and testosterone levels were measured in blood plasma by ELISA.Results: Neutrophil numbers in the bronchoalveolar fluid showed...

Nanotube bundle oscillators: Carbon and boron nitride nanostructures

International Nuclear Information System (INIS)

Thamwattana, Ngamta; Hill, James M.

2009-01-01

In this paper, we investigate the oscillation of a fullerene that is moving within the centre of a bundle of nanotubes. In particular, certain fullerene-nanotube bundle oscillators, namely C 60 -carbon nanotube bundle, C 60 -boron nitride nanotube bundle, B 36 N 36 -carbon nanotube bundle and B 36 N 36 -boron nitride nanotube bundle are studied using the Lennard-Jones potential and the continuum approach which assumes a uniform distribution of atoms on the surface of each molecule. We address issues regarding the maximal suction energies of the fullerenes which lead to the generation of the maximum oscillation frequency. Since bundles are also found to comprise double-walled nanotubes, this paper also examines the oscillation of a fullerene inside a double-walled nanotube bundle. Our results show that the frequencies obtained for the oscillation within double-walled nanotube bundles are slightly higher compared to those of single-walled nanotube bundle oscillators. Our primary purpose here is to extend a number of established results for carbon to the boron nitride nanostructures.

Sperm competition, immunity, selfish genes and cancer.

Science.gov (United States)

Lewis, Z; Price, T A R; Wedell, N

2008-10-01

Sperm competition is widespread and has played an important role in shaping male reproductive characters such as testis size and numbers of sperm produced, and this is reflected in the rapid evolution of many reproductive genes. Additionally, sperm competition has been implicated in the rapid evolution of seminal fluids. However, our understanding of the molecular basis of many traits thought to be important in sperm competition is rudimentary. Furthermore, links between sperm competition and a range of issues not directly related to reproduction are only just beginning to be explored. These include associations between sperm competition and selfish genes, immunity and diseases such as cancer.We briefly review these topics and suggest areas we consider worthy of additional research.

Proteins associated with critical sperm functions and sperm head shape are differentially expressed in morphologically abnormal bovine sperm induced by scrotal insulation

NARCIS (Netherlands)

Saadi, H.A.S.; Riemsdijk, van E.L.C.; Dance, A.L.; Rajamanickam, G.D.; Kastelic, J.P.; Thundathil, J.C.

2013-01-01

The objective was to investigate expression patterns of proteins in pyriform sperm, a common morphological abnormality in bull sperm. Ejaculates were collected from sexually mature Holstein bulls (n = 3) twice weekly for 10 weeks (pre-thermal insult samples). Testicular temperature was elevated in

Trigonellae Semen Enhances Sperm Motility and the Expression of the Cation Sperm Channel Proteins in Mouse Testes

Directory of Open Access Journals (Sweden)

Do Rim Kim

2015-01-01

Full Text Available Genetic defects during spermatogenesis can lead to a reduction in sperm motility and cause male infertility. The cation channels of sperm (CatSper play a role in the regulation of hyperactivated sperm motility in mouse testes. The effect of Trigonellae Semen (TS on the male reproductive system and CatSper protein in mouse testes during spermatogenesis was examined. C57BL/c mice were divided into the following five groups: normal, cyclophosphamide- (CP- only treated (control group, and three groups treated with varying concentrations of TS with CP (100, 500, and 1000 mg/kg TS and 100 mg/kg CP. Real-time PCR, western blot analysis, and a testosterone immunoassay were performed to assess CatSper protein levels in the five groups. Additionally, sperm cell counts and motility were examined. Results indicate that sperm motility and sperm counts increased in the TS treated groups in a dose-dependent manner (p<0.01. CatSper levels were also significantly higher in the TS treated groups compared to that of the control group (p<0.001. Therefore, TS treatment could enhance sperm function by promoting spermatogenesis and the expression of CatSper proteins in mouse testes.

Holomorphic bundles over elliptic manifolds

International Nuclear Information System (INIS)

Morgan, J.W.

2000-01-01

In this lecture we shall examine holomorphic bundles over compact elliptically fibered manifolds. We shall examine constructions of such bundles as well as (duality) relations between such bundles and other geometric objects, namely K3-surfaces and del Pezzo surfaces. We shall be dealing throughout with holomorphic principal bundles with structure group GC where G is a compact, simple (usually simply connected) Lie group and GC is the associated complex simple algebraic group. Of course, in the special case G = SU(n) and hence GC = SLn(C), we are considering holomorphic vector bundles with trivial determinant. In the other cases of classical groups, G SO(n) or G = Sympl(2n) we are considering holomorphic vector bundles with trivial determinant equipped with a non-degenerate symmetric, or skew symmetric pairing. In addition to these classical cases there are the finite number of exceptional groups. Amazingly enough, motivated by questions in physics, much interest centres around the group E8 and its subgroups. For these applications it does not suffice to consider only the classical groups. Thus, while often first doing the case of SU(n) or more generally of the classical groups, we shall extend our discussions to the general semi-simple group. Also, we shall spend a good deal of time considering elliptically fibered manifolds of the simplest type, namely, elliptic curves

Evaluation of bundle duct interaction by out-of-pile compression test of FBR fuel pin bundles

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Kosuke; Yamamoto, Yuji; Nagamine, Tsuyoshi; Maeda, Koji [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

2001-06-01

Bundle duct interaction (BDI) caused by expansion of fuel pin bundle is a main factor to limit the fuel lifetime. Therefore, it is important for the design of fast reactor fuel assembly to understand the fuel pin deformation behavior under BDI condition. In order to understand the fuel pin deformation behavior under BDI condition, out-of-pile compression tests were conducted for FBR fuel pin bundle by use of X-ray CT equipment. In these compression tests, two kinds of fuel pin bundles were conducted. One was the fuel pin bundle with the short wire-pitch and the other was the fuel pin bundle with the short wire-pitch and large diameter claddings. The general discussions were also performed based on the results of out-of-pile compression tests obtained by use of X-ray CT equipment in the previous work. Following results were obtained. 1) The occurrence of the pin-to-duct contact depends on the wire-pitch. In the fuel pin bundle with large wire-pitch, the pin-to-duct contact occurred at the early stage of BDI. The reason of this result is due to the low bowing rigidity of the fuel pins with long wire-pitch. 2) The value of the ovalation stiffness strongly depends on the geometry of cladding (diameter, thickness) and especially on wire-pitch. This result in this work revealed that the occurrence of the pin-to-duct contact depends on the value of the ovalation stiffness. 3) The occurrence of wire dispersion and dispersive displacement of pins depends on the wire-pitch strongly. In the fuel pin bundle with the long wire-pitch, the occurrence of the above-mentioned suppression mechanism to BDI is remarkable. 4) The suppression mechanism to BDI of the fuel pin bundle with the long wire-pitch is elastic oval deformation of cladding, wire dispersion and dispersive displacement of pins. On the other hand, the elastic and plastic oval deformation of cladding is the major suppression mechanism to BDI in the fuel pin bundle with the short wire-pitch. 5) The appearance of

Implementing an open-access CASA software for the assessment of stallion sperm motility: Relationship with other sperm quality parameters.

Science.gov (United States)

Giaretta, Elisa; Munerato, Mauro; Yeste, Marc; Galeati, Giovanna; Spinaci, Marcella; Tamanini, Carlo; Mari, Gaetano; Bucci, Diego

2017-01-01

Setting an open-access computer assisted sperm analysis (CASA) may benefit the evaluation of motility in mammalian sperm, especially when economic constraints do not allow the use of a commercial system. There have been successful attempts to develop such a device in Zebra fish sperm and the system has been used in very few studies on mammalian spermatozoa. Against this background, the present study aimed at developing an open-access CASA system for mammalian sperm using the horse as a model and based upon the Image J software previously established for Zebra fish sperm. Along with determining the sperm progressive motility and other kinetic parameters (such as amplitude of lateral head displacement), the "results" window was adjusted to simplify subsequent statistical analyses. The path window was enriched with colored sperm trajectories on the basis of the subpopulation they belong to and a number that allowed the sperm track to be associated to the sperm motility data shown in the "results" window. Data obtained from the novel plugin (named as CASA_bgm) were compared with those of the commercial CASA Hamilton-Thorn IVOS Vers.12, through Bland Altman's plots. While the percentage of total and progressive motile sperm, VCL, VAP, VSL, LIN and STR and ALH were in agreement with those obtained with the commercial system, BCF significantly differed between the two systems probably due to their settings. Interestingly, a positive and significant correlation between the percentages of total motile sperm evaluated through CASA_bgm and those showing high mitochondrial membrane potential evaluated by JC-1 staining was found. In conclusion, CASA_bgm ImageJ plugin could be useful and reliable for stallion sperm motility analysis and it is our aim to apply this system to other mammalian species. Copyright © 2016 Elsevier B.V. All rights reserved.

Oxidative stress negatively affects human sperm mitochondrial respiration.

Science.gov (United States)

Ferramosca, Alessandra; Pinto Provenzano, Sara; Montagna, Daniela Domenica; Coppola, Lamberto; Zara, Vincenzo

2013-07-01

To correlate the level of oxidative stress in serum and seminal fluid and the level of sperm deoxyribonucleic acid (DNA) fragmentation with sperm mitochondrial respiratory efficiency. Sperm mitochondrial respiratory activity was evaluated with a polarographic assay of oxygen consumption carried out in hypotonically treated sperm cells. A possible relationship between sperm mitochondrial respiratory efficiency, the level of oxidative stress, and the level of sperm DNA fragmentation was investigated. Sperm motility was positively correlated with mitochondrial respiration but negatively correlated with oxidative stress and DNA fragmentation. Interestingly, sperm mitochondrial respiratory activity was negatively affected by oxidative stress and DNA fragmentation. Our data indicate that sperm mitochondrial respiration is decreased in patients with high levels of reactive oxygen species by an uncoupling between electron transport and adenosine triphosphate synthesis. This reduction in mitochondrial functionality might be 1 of the reasons responsible for the decrease in spermatozoa motility. Copyright © 2013 Elsevier Inc. All rights reserved.

Muon bundles from the Universe

Directory of Open Access Journals (Sweden)

Kankiewicz P.

2018-01-01

Full Text Available Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. We argue that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe.

Infinitesimal bundles and projective relativity

International Nuclear Information System (INIS)

Evans, G.T.

1973-01-01

An intrinsic and global presentation of five-dimensional relativity theory is developed, in which special coordinate conditions are replaced by conditions of Lie invariance. The notion of an infinitesimal bundle is introduced, and the theory of connexions on principal bundles is extended to infinitesimal bundles. Global aspects of projective relativity are studied: it is shown that projective relativity can describe almost any space-time. In particular, it is not necessary to assume that the electromagnetic field have a global potential. (author)

CANFLEX fuel bundle strength tests (test report)

International Nuclear Information System (INIS)

Chang, Seok Kyu; Chung, C. H.; Kim, B. D.

1997-08-01

This document outlines the test results for the strength tests of the CANFLEX fuel bundle. Strength tests are performed to determine and verify the amount of the bundle shape distortion which is against the side-stops when the bundles are refuelling. There are two cases of strength test; one is the double side-stop test which simulates the normal bundle refuelling and the other is the single side-stop test which simulates the abnormal refuelling. the strength test specification requires that the fuel bundle against the side-stop(s) simulators for this test were fabricated and the flow rates were controlled to provide the required conservative hydraulic forces. The test rig conditions of 120 deg C, 11.2 MPa were retained for 15 minutes after the flow rate was controlled during the test in two cases, respectively. The bundle loading angles of number 13- number 15 among the 15 bundles were 67.5 deg CCW and others were loaded randomly. After the tests, the bundle shapes against the side-stops were measured and inspected carefully. The important test procedures and measurements were discussed as follows. (author). 5 refs., 22 tabs., 5 figs

Formation of primary sperm conjugates in a haplogyne spider (Caponiidae, Araneae) with remarks on the evolution of sperm conjugation in spiders.

Science.gov (United States)

Lipke, Elisabeth; Michalik, Peter

2012-11-01

Sperm conjugation, where two or more sperm are physically united, is a rare but widespread pheno-menon across the animal kingdom. One group well known for its different types of sperm conjugation are spiders. Particularly, haplogyne spiders show a high diversity of sperm traits. Besides individual cleistospermia, primary (synspermia) and secondary (coenospermia, "spermatophore") sperm conjugation occurs. However, the evolution of sperm conjugates and sperm is not understood in this group. Here, we look at how sperm are transferred in Caponiidae (Haplogynae) in pursuit of additional information about the evolution of sperm transfer forms in spiders. Additionally, we investigated the male reproductive system and spermatozoa using light- and transmission electron-microscopy and provide a 3D reconstruction of individual as of well as conjugated spermatozoa. Mature spermatozoa are characterized by an extremely elongated, helical nucleus resulting in the longest spider sperm known to date. At the end of spermiogenesis, synspermia are formed by complete fusion of four spermatids. Thus, synspermia might have evolved early within ecribellate Haplogynae. The fused sperm cells are surrounded by a prominent vesicular area. The function of the vesicular area remains still unknown but might be correlated with the capacitation process inside the female. Further phylogenetic and functional implications of the spermatozoa and sperm conjugation are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microdissection Testicular Sperm Extraction (micro-TESE as a Sperm Acquisition Method for Men with Nonobstructive Azoospermia Seeking Fertility: Operative and Laboratory Aspects

Directory of Open Access Journals (Sweden)

Sandro C. Esteves

2013-06-01

Full Text Available Introduction Rare foci of sperm production may be found in up to 60% of men with nonobstructive azoospermia (NOA. Sperm production, if present, is minimal for sperm appearance in the ejaculate. Given that there are no treatment options to restore fertility, sperm retrieval is the only alternative to find testicular sperm than then can be used for in vitro fertilization (IVF. Among sperm acquisition methods, micro-TESE has higher success rates at obtaining sperm compared with testicular sperm extraction and testicular sperm aspiration. Materials and Methods This video describes the operative aspects of micro-TESE, performed on an outpatient basis, in a man with NOA and history of cryptorchidism in whom orchidopexy was performed at age 6. The concept of micro-TESE is to identify areas of sperm production within the testes with the aid of optical magnification (15-25X and based on the size and appearance of the seminiferous tubules (ST. Conclusion Micro-TESE allowed the identification and extraction of sperm-containing STs with minimum tissue excision and marked reduction in time processing of testicular specimens for sperm injection.

The Comparison Analysis of Thermalhydraulic Behavior Between A Reference 37-element Bundle and A Modified 37-element Bundle

International Nuclear Information System (INIS)

Ryu, Eui-Seung; You, Sung-Chang

2014-01-01

As pressure tube diameter creep increase, the coolant flows through some of the interior subchannels of the fuel bundle are reduced and consequently reduces the Critical Heat Flux (CHF). For this reason, Canadian Utilities have performed the project that developing the new fuel design (modified 37-element bundle) to increase critical heat flux. The modified 37-element (37M) bundle has the same overall geometry as the reference 37-element (37R) bundle that is using in the Wolsong units now but the center element diameter has been reduced from 13.06mm to 11.5mm. The reduction in center element diameter of the 37M bundle design increase the flow of center areas to improve the cooling and thus to enhance CHF. The CHF experiments with 37M bundle string simulator in un-crept and crept (3.3%, 5.1% peak creep) flow channels were completed at Stern Laboratories in 2008. A substantially large increase in dryout-power was observed for the 37M bundle compared to the 37R bundle, particularly in the 5.1% crept channel. As a result of the experiments, Ontario Power Generation (OPG) and Bruce Power (BP) have increased the operational margin with this CHF correlation and has fully refueled the 37M fuel on some units or almost done on the other units. KHNP also has performed the project to refuel the 37M bundle which is the same design with OPG and BP recently. This paper summarizes the comparison assessment of Thermalhydraulic (T/H) behavior for 37M bundle and 37R bundle with their own correlations and geometry parameters. This analysis performed with the thermal hydraulic code (NUCIRC) and the site measured data at the Wolsong Unit2. Tests to evaluate the CHF performance with the 37M fuel bundle have been conducted in 2008 using the un-crept, 3.3% crept and 5.1% crept flow channels in the CHF Test facility at Stern Laboratories. In addition pressure drop tests have been performed at the same time. The changes of geometry from 37R bundle to 37M bundle reduced the center element

Fiber bundles in non-relativistic quantum mechanics

International Nuclear Information System (INIS)

Moylan, P.

1979-11-01

The problem of describing a quantum-mechanical system with symmetry by a fiber bundle is considered. The quantization of a fiber bundle is introduced. Fiber bundles for the Kepler problem and the rotator are constructed. The fiber bundle concept provides a new model for a physical system: it provides a model for an elementary particle with extension having integral values of spin. 5 figures

Twisted Vector Bundles on Pointed Nodal Curves

Indian Academy of Sciences (India)

Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

Sperm length evolution in the fungus-growing ants

DEFF Research Database (Denmark)

Baer, B.; Dijkstra, M. B.; Mueller, U. G.

2009-01-01

-growing ants, representing 9 of the 12 recognized genera, and mapped these onto the ant phylogeny. We show that average sperm length across species is highly variable and decreases with mature colony size in basal genera with singly mated queens, suggesting that sperm production or storage constraints affect...... the evolution of sperm length. Sperm length does not decrease further in multiply mating leaf-cutting ants, despite substantial further increases in colony size. In a combined analysis, sexual dimorphism explained 63.1% of the variance in sperm length between species. As colony size was not a significant...... predictor in this analysis, we conclude that sperm production trade-offs in males have been the major selective force affecting sperm length across the fungus-growing ants, rather than storage constraints in females. The relationship between sperm length and sexual dimorphism remained robust...

Effects of hydrostatic pressure on mouse sperm.

Science.gov (United States)

Karimi, N; Kamangar, P Bahrami; Azadbakht, M; Amini, A; Amiri, I

2014-01-01

The objective of this study was to investigate the abnormalities in sperm after exposure to hydrostatic pressure. Hydrostatic pressure acting on the cells is one of the fundamental environmental mechanical forces. Disorders of relationship between the cells and this mechanical force, such as when pressure varies beyond physiological limits, can lead to disease or pathological states. Sperm exposed to different range of hydrostatic pressure within male reproductive system and after entering the female reproductive system. Sexually mature male NMRI mice, 8-12 weeks-old were sperm donors. Sperms were separated from the caudal epididymis and maintained in Ham's F-10 culture medium supplemented with 10 % FBS and divided into control and treatments. Sperm suspensions in the treatments were placed within pressure chamber and were subjected to increased hydrostatic pressure of 25, 50 and 100 mmHg (treatment I, II and III) above atmospheric pressure for 2 and 4 h. Sperm viability, motility, morphology, DNA integrity and fertilizing ability were assessed and compared with control. Results showed that hydrostatic pressure dependent on ranges and time manner reduced sperm quality due to adverse effect on viability, motility , morphology, DNA integrity and fertilizing ability in all of treatments, especially after 4h (phydrostatic pressure reduces sperm quality as a consequence of adverse effects on sperm parameters and may cause male infertility or subfertility (Tab. 5, Ref. 5).

BMI in relation to sperm count

DEFF Research Database (Denmark)

Sermondade, N; Faure, C; Fezeu, L

2013-01-01

BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review...... with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men...... studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm...

Tactic-specific differences in seminal fluid influence sperm performance.

Science.gov (United States)

Locatello, Lisa; Poli, Federica; Rasotto, Maria B

2013-03-22

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

Study of Sperm Parameters and Sperm Fertility in Mice were Exposed to Tamoxifen during Embryonic Development

Directory of Open Access Journals (Sweden)

J Soleimanirad

2017-05-01

Full Text Available Introduction: Tamoxifen is steroidal drug, which mainly treats breast cancer and also used to stimulate ovulation. The purpose of the present study was the evaluation of sperm parameters and fertility of mice whose mothers had received tamoxifen during pregnancy. Methods: In this study, 30 female and 15 male mice of NMRI were selected for mating. After mating female mice were randomly divided into two groups, the first group (control and second group (experimental. All of which contained 15 mice. From the day 13th day of pregnancy, experimental group has received tamoxifen with the dosage of 5 mg/kg for 7 days. After childbirth of the mated mice, male infants were selected. After reaching the age of puberty (6-8Weeks, adult mice were sacrificed by the cervical dislocation. After take sperm, sperm parameters (count, normality and motility, and sperm fertility was performed. In this study SPSS software and statistical t-test was used (p <0.001. Results: Studies showed that sperm parameters and sperm fertilization were significantly different. The number of sperm in the control group was 83.50±28.20 million, and in the experimental group was 60±14.14 million. There was a decrease in average sperm count in the experimental group compared with the control group (p <0.001. Our findings from in vitro fertilization culture media showed that embryos formation and oocyte disruption between control and experimental groups significantly different (p <0.001. Conclusion: The results showed that tamoxifen exposure during development can cause histological changes in the seminiferous tubules, which can lead to infertility.

Preliminary report: NIF laser bundle review

International Nuclear Information System (INIS)

Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

1995-01-01

As requested in the guidance memo 1 , this committe determined whether there are compelling reasons to recommend a change from the NIF CDR baseline laser. The baseline bundle design based on a tradeoff between cost and technical risk, which is replicated four times to create the required 192 beams. The baseline amplifier design uses bottom loading 1x4 slab and flashlamp cassettes for amplifier maintenance and large vacuum enclosures (2.5m high x 7m wide in cross-section for each of the two spatial filters in each of the four bundles. The laser beams are arranged in two laser bays configured in a u-shape around the target area. The entire bundle review effort was performed in a very short time (six weeks) and with limited resources (15 personnel part-time). This should be compared to the effort that produced the CDR design (12 months, 50 to 100 personnel). This committee considered three alternate bundle configurations (2x2, 4x2, and 4x4 bundles), and evaluated each bundle against the baseline design using the seven requested issues in the guidance memo: Cost; schedule; performance risk; maintainability/operability; hardware failure cost exposure; activation; and design flexibility. The issues were reviewed to identify differences between each alternate bundle configuration and the baseline

Warps, grids and curvature in triple vector bundles

Science.gov (United States)

Flari, Magdalini K.; Mackenzie, Kirill

2018-06-01

A triple vector bundle is a cube of vector bundle structures which commute in the (strict) categorical sense. A grid in a triple vector bundle is a collection of sections of each bundle structure with certain linearity properties. A grid provides two routes around each face of the triple vector bundle, and six routes from the base manifold to the total manifold; the warps measure the lack of commutativity of these routes. In this paper we first prove that the sum of the warps in a triple vector bundle is zero. The proof we give is intrinsic and, we believe, clearer than the proof using decompositions given earlier by one of us. We apply this result to the triple tangent bundle T^3M of a manifold and deduce (as earlier) the Jacobi identity. We further apply the result to the triple vector bundle T^2A for a vector bundle A using a connection in A to define a grid in T^2A . In this case the curvature emerges from the warp theorem.

Comparison of cryopreserved human sperm in vapor and liquid phases of liquid nitrogen: effect on motility parameters, morphology, and sperm function.

Science.gov (United States)

Punyatanasakchai, Piyaphan; Sophonsritsuk, Areephan; Weerakiet, Sawaek; Wansumrit, Surapee; Chompurat, Deonthip

2008-11-01

To compare the effects of cryopreserved sperm in vapor and liquid phases of liquid nitrogen on sperm motility, morphology, and sperm function. Experimental study. Andrology laboratory at Ramathibodi Hospital, Thailand. Thirty-eight semen samples with normal motility and sperm count were collected from 38 men who were either patients of an infertility clinic or had donated sperm for research. Each semen sample was divided into two aliquots. Samples were frozen with static-phase vapor cooling. One aliquot was plunged into liquid nitrogen (-196 degrees C), and the other was stored in vapor-phase nitrogen (-179 degrees C) for 3 days. Thawing was performed at room temperature. Motility was determined by using computer-assisted semen analysis, sperm morphology was determined by using eosin-methylene blue staining, and sperm function was determined by using a hemizona binding test. Most of the motility parameters of sperm stored in the vapor phase were not significantly different from those stored in the liquid phase of liquid nitrogen, except in amplitude of lateral head displacement. The percentages of normal sperm morphology in both vapor and liquid phases also were not significantly different. There was no significant difference in the number of bound sperm in hemizona between sperm cryopreserved in both vapor and liquid phases of liquid nitrogen. Cryopreservation of human sperm in a vapor phase of liquid nitrogen was comparable to cryopreservation in a liquid phase of liquid nitrogen.

Viscoelasticity promotes collective swimming of sperm

Science.gov (United States)

Tung, Chih-Kuan; Harvey, Benedict B.; Fiore, Alyssa G.; Ardon, Florencia; Suarez, Susan S.; Wu, Mingming

From flocking birds to swarming insects, interactions of organisms large and small lead to the emergence of collective dynamics. Here, we report striking collective swimming of bovine sperm, with sperm orienting in the same direction within each cluster, enabled by the viscoelasticity of the fluid. A long-chain polyacrylamide solution was used as a model viscoelastic fluid such that its rheology can be fine-tuned to mimic that of bovine cervical mucus. In viscoelastic fluid, sperm formed dynamic clusters, and the cluster size increased with elasticity of the polyacrylamide solution. In contrast, sperm swam randomly and individually in Newtonian fluids of similar viscosity. Analysis of the fluid motion surrounding individual swimming sperm indicated that sperm-fluid interaction is facilitated by the elastic component of the fluid. We note that almost all biological fluids (e.g. mucus and blood) are viscoelastic in nature, this finding highlights the importance of fluid elasticity in biological function. We will discuss what the orientation fluctuation within a cluster reveals about the interaction strength. Supported by NIH Grant 1R01HD070038.

Variation in sperm morphometry and sperm competition among barn swallow (Hirundo rustica) populations

Czech Academy of Sciences Publication Activity Database

Laskemoen, T.; Albrecht, Tomáš; Bonisoli-Alquati, A.; Cepák, J.; De Lope, F.; Hermosell, I. G.; Johannessen, L. E.; Kleven, O.; Marzal, A.; Mousseau, T. A.; Moller, A. P.; Robertson, R. J.; Rudolfsen, G.; Saino, N.; Vortman, Y.; Lifjeld, J. T.

2013-01-01

Roč. 67, č. 2 (2013), s. 301-309 ISSN 0340-5443 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : Barn swallow * Extrapair paternity * Hirundo rustica * Sperm competition * Sperm size Subject RIV: EG - Zoology Impact factor: 3.049, year: 2013

Delta opioid receptor on equine sperm cells: subcellular localization and involvement in sperm motility analyzed by computer assisted sperm analyzer (CASA

Directory of Open Access Journals (Sweden)

Lacalandra Giovanni M

2010-06-01

Full Text Available Abstract Background Opioid receptors and endogenous opioid peptides act not only in the control of nociceptive pathways, indeed several reports demonstrate the effects of opiates on sperm cell motility and morphology suggesting the importance of these receptors in the modulation of reproduction in mammals. In this study we investigated the expression of delta opioid receptors on equine spermatozoa by western blot/indirect immunofluorescence and its relationship with sperm cell physiology. Methods We analyzed viability, motility, capacitation, acrosome reaction and mitochondrial activity in the presence of naltrindole and DPDPE by means of a computer assisted sperm analyzer and a fluorescent confocal microscope. The evaluation of viability, capacitation and acrosome reaction was carried out by the double CTC/Hoechst staining, whereas mitochondrial activity was assessed by means of MitoTracker Orange dye. Results We showed that in equine sperm cells, delta opioid receptor is expressed as a doublet of 65 and 50 kDa molecular mass and is localized in the mid piece of tail; we also demonstrated that naltrindole, a delta opioid receptor antagonist, could be utilized in modulating several physiological parameters of the equine spermatozoon in a dose-dependent way. We also found that low concentrations of the antagonist increase sperm motility whereas high concentrations show the opposite effect. Moreover low concentrations hamper capacitation, acrosome reaction and viability even if the percentage of cells with active mitochondria seems to be increased; the opposite effect is exerted at high concentrations. We have also observed that the delta opioid receptor agonist DPDPE is scarcely involved in affecting the same parameters at the employed concentrations. Conclusions The results described in this paper add new important details in the comprehension of the mammalian sperm physiology and suggest new insights for improving reproduction and for

Sex-sorting sperm using flow cytometry/cell sorting.

Science.gov (United States)

Garner, Duane L; Evans, K Michael; Seidel, George E

2013-01-01

The sex of mammalian offspring can be predetermined by flow sorting relatively pure living populations of X- and Y-chromosome-bearing sperm. This method is based on precise staining of the DNA of sperm with the nucleic acid-specific fluorophore, Hoechst 33342, to differentiate between the subpopulations of X- and Y-sperm. The fluorescently stained sperm are then sex-sorted using a specialized high speed sorter, MoFlo(®) SX XDP, and collected into biologically supportive media prior to reconcentration and cryopreservation in numbers adequate for use with artificial insemination for some species or for in vitro fertilization. Sperm sorting can provide subpopulations of X- or Y-bearing bovine sperm at rates in the 8,000 sperm/s range while maintaining; a purity of 90% such that it has been applied to cattle on a commercial basis. The sex of offspring has been predetermined in a wide variety of mammalian species including cattle, swine, horses, sheep, goats, dogs, cats, deer, elk, dolphins, water buffalo as well as in humans using flow cytometric sorting of X- and Y-sperm.

Intracytoplasmic sperm injection outcomes with cryopreserved testicular sperm aspiration samples.

Science.gov (United States)

Roque, M; Valle, M; Marques, F; Sampaio, M; Geber, S

2016-04-01

Intracytoplasmic sperm injection (ICSI) may be performed with testicular frozen-thawed spermatozoa in patients with nonobstructive azoospermia (NOA). Sperm retrieval can be performed in advance of oocyte aspiration, as it may avoid the possibility of no recovery of spermatozoa on the day of oocyte pickup. There are few studies available in the literature concerning the use of frozen-thawed spermatozoa obtained from testicular sperm aspiration (TESA). To evaluate the effects and the outcomes of ICSI with frozen-thawed spermatozoa obtained by TESA, we performed a retrospective analysis of 43 ICSI cycles using frozen-thawed TESA. We obtained acceptable results with a fertilisation rate of 67.9%, an implantation rate (IR) of 17.1%, and clinical and ongoing pregnancy rates of 41.9% and 37.2% respectively. The results of this study suggest that performing ICSI using cryopreserved frozen-thawed testicular spermatozoa with TESA as a first option is a viable, safe, economic and effective method for patients with NOA. © 2015 Blackwell Verlag GmbH.

Bundling ecosystem services in Denmark

DEFF Research Database (Denmark)

Turner, Katrine Grace; Odgaard, Mette Vestergaard; Bøcher, Peder Klith

2014-01-01

We made a spatial analysis of 11 ecosystem services at a 10 km × 10 km grid scale covering most of Denmark. Our objective was to describe their spatial distribution and interactions and also to analyze whether they formed specific bundle types on a regional scale in the Danish cultural landscape....... We found clustered distribution patterns of ecosystem services across the country. There was a significant tendency for trade-offs between on the one hand cultural and regulating services and on the other provisioning services, and we also found the potential of regulating and cultural services...... to form synergies. We identified six distinct ecosystem service bundle types, indicating multiple interactions at a landscape level. The bundle types showed specialized areas of agricultural production, high provision of cultural services at the coasts, multifunctional mixed-use bundle types around urban...

Sperm DNA quality evaluated by comet assay and sperm chromatin structure assay in stallions after unilateral orchiectomy.

Science.gov (United States)

Serafini, R; Varner, D D; Bissett, W; Blanchard, T L; Teague, S R; Love, C C

2015-09-15

Unilateral orchiectomy (UO) may interfere with thermoregulation of the remaining testis caused by inflammation surrounding the incision site, thus altering normal spermatogenesis and consequently sperm quality. Two measures of sperm DNA quality (neutral comet assay and the sperm chromatin structure assay [SCSA]) were compared before UO (0 days) and at 14, 30, and 60 days after UO to determine whether sperm DNA changed after a mild testis stress (i.e., UO). The percent DNA in the comet tail was higher at 14 and 60 days compared to 0 days (P comet tail measures (i.e., length, moment, migration) were higher at all time periods after UO compared to 0 days (P comet assay and the SCSA, which was not identified using traditional measures of sperm quality. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of droplet deposition in rod bundle

International Nuclear Information System (INIS)

Ji, W.; Gu, C.Y.; Anglart, H.

1997-01-01

Deposition model for droplets in gas droplet two-phase flow in rod bundle is developed in this work using the Lagrangian method. The model is evaluated in a 9-rod bundle geometry. The deposition coefficient in the bundle geometry are compared with that in round tube. The influences of the droplet size and gas mass flow rate on deposition coefficient are investigated. Furthermore, the droplet motion is studied in more detail by dividing the bundle channel into sub-channels. The results show that the overall deposition coefficient in the bundle geometry is close to that in the round tube with the diameter equal to the bundle hydraulic diameter. The calculated deposition coefficient is found to be higher for higher gas mass flux and smaller droplets. The study in the sub-channels show that the ratio between the local deposition coefficient for a sub-channel and the averaged value for the whole bundle is close to a constant value, deviations from the mean value for all the calculated cases being within the range of ±13%. (author)

Outdoor air pollution and sperm quality.

Science.gov (United States)

Lafuente, Rafael; García-Blàquez, Núria; Jacquemin, Bénédicte; Checa, Miguel Angel

2016-09-15

Exposure to air pollution has been clearly associated with a range of adverse health effects, including reproductive toxicity, but its effects on male semen quality are still unclear. We performed a systematic review (up to June 2016) to assess the impact of air pollutants on sperm quality. We included 17 semi-ecological, panel, and cohort studies, assessing outdoor air pollutants, such as PM2.5, PM10, NOx, SO2, and O3, and their effects on DNA fragmentation, sperm count, sperm motility, and sperm morphology. Thirteen studies assessed air pollution exposure measured environmentally, and six used biomarkers of air pollution exposure (two did both). We rated the studies using the Newcastle-Ottawa Scale and assessed with the exposure method. Taking into account these factors and the number of studies finding significant results (positive or negative), the evidence supporting an effect of air pollution on DNA fragmentation is weak but suggestive, on sperm motility is limited and probably inexistent, on lower sperm count is inconclusive, and on sperm morphology is very suggestive. Because of the diversity of air pollutants and sperm parameters, and the studies' designs, we were unable to perform a meta-analysis. In summary, most studies concluded that outdoor air pollution affects at least one of the four semen quality parameters included in the review. However, results lack consistency, and furthermore, studies were not comparable. Studies using standardized air pollution and semen measures are required to obtain more reliable conclusions. CRD42015007175. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Prudent sperm use by leaf-cutter ant queens

DEFF Research Database (Denmark)

Den Boer, Susanne Petronella A; Baer, Boris; Dreier, Stéphanie Agnès Jeanine

2009-01-01

are able to fertilize close to 100 per cent of the eggs and that the average sperm use per egg is very low, but increases with queen age. The robustness of stored sperm was found to decrease with years of storage, signifying that senescence affects sperm either directly or indirectly via the declining...... glandular secretions or deteriorating sperm-storage organs. We evaluate our findings with a heuristic model, which suggests that the average queen has sperm for almost 9 years of normal colony development. We discuss the extent to which leaf-cutter ant queens have been able to optimize their sperm...

Bundle Security Protocol for ION

Science.gov (United States)

Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

2011-01-01

This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

Connections on discrete fibre bundles

International Nuclear Information System (INIS)

Manton, N.S.; Cambridge Univ.

1987-01-01

A new approach to gauge fields on a discrete space-time is proposed, in which the fundamental object is a discrete version of a principal fibre bundle. If the bundle is twisted, the gauge fields are topologically non-trivial automatically. (orig.)

Testicular Damage following Testicular Sperm Retrieval

DEFF Research Database (Denmark)

Fedder, Jens; Marcussen, Niels; Fedder, Maja D.K.

2017-01-01

The aim of this study was to evaluate the possible development of histological abnormalities such as fibrosis and microcalcifications after sperm retrieval in a ram model. Fourteen testicles in nine rams were exposed to open biopsy, multiple TESAs, or TESE, and the remaining four testicles were...... left unoperated on as controls. Three months after sperm retrieval, the testicles were removed, fixed, and cut into 1/2 cm thick slices and systematically put onto a glass plate exposing macroscopic abnormalities. Tissue from abnormal areas was cut into 3 μm sections and stained for histological...... evaluation. Pathological abnormalities were observed in testicles exposed to sperm retrieval (≥11 of 14) compared to 0 of 4 control testicles. Testicular damage was found independently of the kind of intervention used. Therefore, cryopreservation of excess sperm should be considered while retrieving sperm....

The predictive value of parameters of clinical presentations for sperm yield in patients with nonobstructive azoospermia receiving microdissection testicular sperm extraction

Directory of Open Access Journals (Sweden)

Ming-Hsuan Ku

2017-12-01

Conclusion: Clinical presentations or phenotypes can be used as predictive factors for successful sperm retrieval during mTESE in patients with NOA. Hypogonadotropic hypogonadism and cases with UDT history have a higher chance of sperm retrieval. Initial testicular needle biopsy, if available, can provide valuable information about chances of sperm retrieval. Hypospermatogenesis predicts high sperm yield rate, and LMA can have best upgrade results of sperm yield after mTESE.

Deformation quantization of principal fibre bundles

International Nuclear Information System (INIS)

Weiss, S.

2007-01-01

Deformation quantization is an algebraic but still geometrical way to define noncommutative spacetimes. In order to investigate corresponding gauge theories on such spaces, the geometrical formulation in terms of principal fibre bundles yields the appropriate framework. In this talk I will explain what should be understood by a deformation quantization of principal fibre bundles and how associated vector bundles arise in this context. (author)

Deformations of the generalised Picard bundle

International Nuclear Information System (INIS)

Biswas, I.; Brambila-Paz, L.; Newstead, P.E.

2004-08-01

Let X be a nonsingular algebraic curve of genus g ≥ 3, and let Mξ denote the moduli space of stable vector bundles of rank n ≥ 2 and degree d with fixed determinant ξ over X such that n and d are coprime. We assume that if g = 3 then n ≥ 4 and if g = 4 then n ≥ 3, and suppose further that n 0 , d 0 are integers such that n 0 ≥ 1 and nd 0 + n 0 d > nn 0 (2g - 2). Let E be a semistable vector bundle over X of rank n 0 and degree d 0 . The generalised Picard bundle W ξ (E) is by definition the vector bundle over M ξ defined by the direct image p M ξ *(U ξ x p X * E) where U ξ is a universal vector bundle over X x M ξ . We obtain an inversion formula allowing us to recover E from W ξ (E) and show that the space of infinitesimal deformations of W ξ (E) is isomorphic to H 1 (X, End(E)). This construction gives a locally complete family of vector bundles over M ξ parametrised by the moduli space M(n 0 ,d 0 ) of stable bundles of rank n 0 and degree d 0 over X. If (n 0 ,d 0 ) = 1 and W ξ (E) is stable for all E is an element of M(n 0 ,d 0 ), the construction determines an isomorphism from M(n 0 ,d 0 ) to a connected component M 0 of a moduli space of stable sheaves over M ξ . This applies in particular when n 0 = 1, in which case M 0 is isomorphic to the Jacobian J of X as a polarised variety. The paper as a whole is a generalisation of results of Kempf and Mukai on Picard bundles over J, and is also related to a paper of Tyurin on the geometry of moduli of vector bundles. (author)

Stability of Picard bundle over moduli space of stable vector bundles ...

Indian Academy of Sciences (India)

Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

Since the morphism ϕ is given by the universal property of the moduli space, the pullback of the universal bundle E on X × M to X × P by the map idX × ϕ is isomorphic (up to a twist by a line bundle coming from P) to ˜E. In other words, there is an integer k such that. 0 −→ (idX × ϕ)∗E −→ W ⊠ OP (k) −→ Ox×P (k + 1) −→ 0.

Characteristics of CANDU fuel bundles that caused pressure tube fretting at the bundle midplane

Energy Technology Data Exchange (ETDEWEB)

Dennier, D; Manzer, A M [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Koehn, E [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

Detailed measurements on new bundles, and those that caused fretting during in- and out-reactor tests, have given insight into the factors responsible for fretting at the midplane of the inlet bundle. Bottom fuel elements that were attached near radial endplate spokes and had inboard bearing pads in the rolled joint cavity produced a significant portion of the observed fret marks. These elements are influenced by several driving forces that deflect the centre bearing pads towards the pressure tube surface. The evidence suggests that slight changes in bundle design may be possible to reduce pressure tube fretting. (author). 4 refs., 3 tabs., 8 figs.

Sperm DNA fragmentation, recurrent implantation failure and recurrent miscarriage

Directory of Open Access Journals (Sweden)

Carol Coughlan

2015-01-01

Full Text Available Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage (RM. To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure (RIF following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers (control were examined. Sperm were examined pre- and post-density centrifugation by the sperm chromatin dispersion (SCD test and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay. There were no significant differences in the age of either partner or sperm concentration, motility or morphology between three groups. Moreover, there were no obvious differences in sperm DNA fragmentation measured by either test. However, whilst on average sperm DNA fragmentation in all groups was statistically lower in prepared sperm when measured by the SCD test, this was not seen with the results from the TUNEL assay. These results do not support the hypothesis that sperm DNA fragmentation is an important cause of RIF or RM, or that sperm DNA integrity testing has value in such patients. It also highlights significant differences between test methodologies and sperm preparation methods in interpreting the data from sperm DNA fragmentation tests.

Gold-standard for computer-assisted morphological sperm analysis.

Science.gov (United States)

Chang, Violeta; Garcia, Alejandra; Hitschfeld, Nancy; Härtel, Steffen

2017-04-01

Published algorithms for classification of human sperm heads are based on relatively small image databases that are not open to the public, and thus no direct comparison is available for competing methods. We describe a gold-standard for morphological sperm analysis (SCIAN-MorphoSpermGS), a dataset of sperm head images with expert-classification labels in one of the following classes: normal, tapered, pyriform, small or amorphous. This gold-standard is for evaluating and comparing known techniques and future improvements to present approaches for classification of human sperm heads for semen analysis. Although this paper does not provide a computational tool for morphological sperm analysis, we present a set of experiments for comparing sperm head description and classification common techniques. This classification base-line is aimed to be used as a reference for future improvements to present approaches for human sperm head classification. The gold-standard provides a label for each sperm head, which is achieved by majority voting among experts. The classification base-line compares four supervised learning methods (1- Nearest Neighbor, naive Bayes, decision trees and Support Vector Machine (SVM)) and three shape-based descriptors (Hu moments, Zernike moments and Fourier descriptors), reporting the accuracy and the true positive rate for each experiment. We used Fleiss' Kappa Coefficient to evaluate the inter-expert agreement and Fisher's exact test for inter-expert variability and statistical significant differences between descriptors and learning techniques. Our results confirm the high degree of inter-expert variability in the morphological sperm analysis. Regarding the classification base line, we show that none of the standard descriptors or classification approaches is best suitable for tackling the problem of sperm head classification. We discovered that the correct classification rate was highly variable when trying to discriminate among non-normal sperm

Total motile sperm count has a superior predictive value over the WHO 2010 cut-off values for the outcomes of intracytoplasmic sperm injection cycles.

Science.gov (United States)

Borges, E; Setti, A S; Braga, D P A F; Figueira, R C S; Iaconelli, A

2016-09-01

The objective of this study was to compare (i) the intracytoplasmic sperm injection outcomes among groups with different total motile sperm count ranges, (ii) the intracytoplasmic sperm injection outcomes between groups with normal and abnormal total motile sperm count, and (iii) the predictive values of WHO 2010 cut-off values and pre-wash total motile sperm count for the intracytoplasmic sperm injection outcomes, in couples with male infertility. This study included data from 518 patients undergoing their first intracytoplasmic sperm injection cycle as a result of male infertility. Couples were divided into five groups according to their total motile sperm count: Group I, total motile sperm count sperm count 1-5 × 10(6) ; group III, total motile sperm count 5-10 × 10(6) ; group IV, total motile sperm count 10-20 × 10(6) ; and group V, total motile sperm count >20 × 10(6) (which was considered a normal total motile sperm count value). Then, couples were grouped into an abnormal and normal total motile sperm count group. The groups were compared regarding intracytoplasmic sperm injection outcomes. The predictive values of WHO 2010 cut-off values and total motile sperm count for the intracytoplasmic sperm injection outcomes were also investigated. The fertilization rate was lower in total motile sperm count group I compared to total motile sperm count group V (72.5 ± 17.6 vs. 84.9 ± 14.4, p = 0.011). The normal total motile sperm count group had a higher fertilization rate (84.9 ± 14.4 vs. 81.1 ± 15.8, p = 0.016) and lower miscarriage rate (17.9% vs. 29.5%, p = 0.041) compared to the abnormal total motile sperm count group. The total motile sperm count was the only parameter that demonstrated a predictive value for the formation of high-quality embryos on D2 (OR: 1.18, p = 0.013), formation of high-quality embryos on D3 (OR: 1.12, p = 0.037), formation of blastocysts on D5 (OR: 1.16, p = 0.011), blastocyst expansion grade on D5

Sperm motility and morphology as changing parameters linked to sperm count variations.

OpenAIRE

Dua A; Vaidya S

1996-01-01

Variations in semen analyses of 177 males over a 1 year period were assessed. The average means of total counts, motility, morphology, total motile count and non-motile % were determined for 5 classes of patients ranging from azoospermic to normospermic. Positive relationships between a falling sperm count, a decrease in motility and total motile counts were seen. Also, increasingly, abnormal forms were found with lower sperm counts.

Study of fuel bundle geometry on inter subchannel flow in a 19 pin wire wrapped bundle

International Nuclear Information System (INIS)

Naveen Raj, M.; Velusamy, D.K.

2015-01-01

In typical sodium cooled fast reactor (SFR) fuel pin bundle, gap between the pins is maintained by helically wound wire wrap around each pin. The presence of wire induces large inter-subchannel transverse flow, eventually promoting mixing and heat transfer. The magnitude of the transverse flow is highly dependent on the various pin-bundle dimensions. Appropriate modeling of these transverse flows in subchannel codes is necessary to predict realistic temperature distribution in pin bundle. Hence, detailed parametric study of transverse flow on pin-bundle geometric parameters has been conducted. The parameters taken for the present study are pin diameter, wire diameter, helical wire pitch and edge gap. Towards this 3-D computational fluid dynamic analysis on a structured mesh of 19 pin bundle is carried out using k-epsilon turbulence model. Periodic oscillations along the primacy flow direction were found in subchannel transverse flow and peripheral pin clad temperatures with periodicity over one pitch length. Based on parametric studies, correlations for transverse flow in central subchannels are proposed. (author)

Lifestyle influences human sperm functional quality

Institute of Scientific and Technical Information of China (English)

Mnica Ferreira; Joana Vieira Silva; Vladimiro Silva; Antnio Barros; Margarida Fardilha

2012-01-01

Objective:To investigate the impact of acute lifestyle changes on human sperm functional quality.Methods:In the academic festivities week, young and apparently healthy male students who voluntarily submit themselves to acute lifestyle alterations(among the potentially important variations are increase in alcohol, caffeine, and tobacco consumption and circadian rhythm shifts) were used as a model system.Sperm samples were obtained before and after the academic week and compared by traditional semen analysis(n=54) and also tested for cleavedPolyADP-ribose polymerase(PARP) protein, an apoptotic marker(n=35).Results:Acute lifestyle changes that occurred during the academic week festivities(the study model) resulted both in a significant reduction in sperm quality, assessed by basic semen analysis(decrease in sperm concentration, total number of spermatozoa, progressive and non-progressive motility and increase in sperm morphological abnormalities) and by an increase in the expression of the apoptotic marker, cleavedPARP, in the ejaculate.Conclusions:Acute lifestyle changes have clear deleterious effects on sperm quality.We propose cleavedPARP as a novel molecular marker, valuable for assessing spermquality in parallel with the basic semen analysis method.

Environmental toxicants cause sperm DNA fragmentation as detected by the Sperm Chromatin Structure Assay (SCSA[reg])

International Nuclear Information System (INIS)

Evenson, Donald P.; Wixon, Regina

2005-01-01

Studies over the past two decades have clearly shown that reproductive toxicants cause sperm DNA fragmentation. This DNA fragmentation can usually be detected prior to observing alterations of metaphase chromosomes in embryos. Thus, Sperm Chromatin Structure Assay (SCSA)-detected DNA damage is viewed as the molecular precursor to later gross chromosome damage observed under the light microscope. SCSA measurements of animal or human sperm consist of first obtaining a fresh or flash frozen neat semen sample in LN2 or dry ice. Samples are then sent to a SCSA diagnostic laboratory where the samples are thawed, diluted to ∼1-2 x 106 sperm/ml, treated for 30 s with a pH 1.2 detergent buffer and then stained with acridine orange (AO). The low pH partially denatures DNA at the sites of DNA strand breaks and the AO-ssDNA fluoresces red while the AO-dsDNA fluoresces green. Flow cytometry measurements of 5000 sperm/sample provide statistically robust data on the ratio of red to green sperm, the extent of the DNA fragmentation and the standard deviations of measures. Numerous experiments on rodents treated with reproductive toxicants clearly showed that SCSA measures are highly dose responsive and have a very low CV. Different agents that act on germ cells at various stages of development usually showed sperm DNA fragmentation when that germ cell fraction arrived in the epididymis or ejaculate. Some of these treated samples were capable of successful in vitro fertilization but with frequent embryo failure. A 2-year longitudinal study of men living a valley town with a reported abnormal level of infertility and spontaneous miscarriages and also a seasonal atmospheric smog pollution, showed, for the first time, that SCSA measurements of human sperm DNA fragmentation were detectable and correlated with dosage of air pollution while the classical semen measures were not correlated. Also, young men spraying pesticides without protective gear are at an increased risk for elevated

A comparison of sperm agglutination and immobilization assays with a quantitative ELISA for anti-sperm antibody in serum.

Science.gov (United States)

Lynch, D M; Leali, B A; Howe, S E

1986-08-01

An enzyme-linked immunosorbent assay (ELISA) that quantitates antisperm antibody in serum was compared with standard sperm agglutination and immobilization assays with the use of sera from 40 normal and 292 subfertile individuals. Quantitation of the assay was accomplished by standardizing assay parameters, including the incorporation of a standard reference curve, the number of whole target sperm, the optimal dilution of serum, the selection of microtiter plate, and the time and temperatures involved in the adsorption and incubation phases. With this method, the level of antisperm antibody binding to target sperm in 40 normal fertile individuals was found to be 2.3 (+/- 1.1 standard deviation [SD]) fg immunoglobulin (Ig)/sperm. An increased mean level of 7.4 +/- 3.7 fg Ig/sperm was determined in 84 infertile patients with positive agglutination and/or immobilization tests. In 208 individuals with negative agglutination and immobilization tests the mean concentration of antisperm antibody was 2.5 +/- 1.3 fg Ig/sperm. Postvasectomy patients assayed by this method had a mean Ig binding value of 7.1 +/- 2.4 fg Ig/sperm. The infertile group with positive agglutination and/or immobilization tests had a significantly higher mean antisperm antibody level than the normal fertile group, according to the Student's t-test for independent samples (P less than 0.001). This indirect serum-based assay reproducibly quantitates antisperm antibody binding to whole target sperm, suggests the normal and abnormal levels of antisperm antibody, and correlates with standard functional assays.

Hydraulic characteristics of HANARO fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Cho, S; Chung, H J; Chun, S Y; Yang, S K; Chung, M K [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

Hydraulic characteristics of HANARO fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

In-pool damaged fuel bundle recovery

International Nuclear Information System (INIS)

Piascik, T.G.; Patenaude, R.S.

1988-01-01

While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power / Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved

Verification of the FBR fuel bundle-duct interaction analysis code BAMBOO by the out-of-pile bundle compression test with large diameter pins

Science.gov (United States)

Uwaba, Tomoyuki; Ito, Masahiro; Nemoto, Junichi; Ichikawa, Shoichi; Katsuyama, Kozo

2014-09-01

The BAMBOO computer code was verified by results for the out-of-pile bundle compression test with large diameter pin bundle deformation under the bundle-duct interaction (BDI) condition. The pin diameters of the examined test bundles were 8.5 mm and 10.4 mm, which are targeted as preliminary fuel pin diameters for the upgraded core of the prototype fast breeder reactor (FBR) and for demonstration and commercial FBRs studied in the FaCT project. In the bundle compression test, bundle cross-sectional views were obtained from X-ray computer tomography (CT) images and local parameters of bundle deformation such as pin-to-duct and pin-to-pin clearances were measured by CT image analyses. In the verification, calculation results of bundle deformation obtained by the BAMBOO code analyses were compared with the experimental results from the CT image analyses. The comparison showed that the BAMBOO code reasonably predicts deformation of large diameter pin bundles under the BDI condition by assuming that pin bowing and cladding oval distortion are the major deformation mechanisms, the same as in the case of small diameter pin bundles. In addition, the BAMBOO analysis results confirmed that cladding oval distortion effectively suppresses BDI in large diameter pin bundles as well as in small diameter pin bundles.

Toward microfluidic sperm refinement: continuous flow label-free analysis and sorting of sperm cells

NARCIS (Netherlands)

de Wagenaar, B.; Dekker, Stefan; van den Berg, Albert; Segerink, Loes Irene

2015-01-01

This manuscript reports upon the development of a microfluidic setup to detect and sort sperm cells from polystyrene beads label-free and non-invasively. Detection is performed by impedance analysis. When sperm cells passed the microelectrodes, the recorded impedance (19.6 ± 5.7 Ω) was higher

Mitochondrial respiratory efficiency is positively correlated with human sperm motility.

Science.gov (United States)

Ferramosca, Alessandra; Provenzano, Sara Pinto; Coppola, Lamberto; Zara, Vincenzo

2012-04-01

To correlate sperm mitochondrial respiratory efficiency with variations in sperm motility and with sperm morphologic anomalies. Sperm mitochondrial respiratory activity was evaluated with a polarographic assay of oxygen consumption carried out in hypotonically-treated sperm cells. A possible relationship among sperm mitochondrial respiratory efficiency, sperm motility, and morphologic anomalies was investigated. Mitochondrial respiratory efficiency was positively correlated with sperm motility and negatively correlated with the percentage of immotile spermatozoa. Moreover, midpiece defects impaired mitochondrial functionality. Our data indicate that an increase in sperm motility requires a parallel increase in mitochondrial respiratory capacity, thereby supporting the fundamental role played by mitochondrial oxidative phosphorylation in sperm motility of normozoospermic subjects. These results are of physiopathological relevance because they suggest that disturbances of sperm mitochondrial function and of energy production could be responsible for asthenozoospermia. Copyright © 2012 Elsevier Inc. All rights reserved.

Diisopropyl fluorophosphate labeling of sperm-associated proteinases

International Nuclear Information System (INIS)

Odem, R.R.; Willand, J.L.; Polakoski, K.L.

1990-01-01

Proteinase inhibitors have been shown to be capable of preventing various aspects of fertilization. Diisopropyl fluorophosphate (DFP) is an irreversible inhibitor of trypsin-like enzymes that is commercially available in a radiolabeled form. The experiments described herein were designed to determine if DFP would prevent sperm function in live, motile sperm and to identify the sperm proteins bound with DFP. DFP at 5 mM concentrations had no observable effect on sperm motility, but inhibited the penetration of zona-free hamster ova by human sperm (5.5%) compared to controls (33.5%). Acid extracts of motile sperm that had been incubated with radiolabeled DFP and collected by the swim-up procedure demonstrated the presence of radiolabeled DFP, and the autoradiography of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels of these extracts localized the uptake of radiolabeled DFP to proteins in the molecular weight region of the proacrosin-acrosin system. Acid-extracted proteinases from semen samples incubated with DFP demonstrated a concentration-dependent inhibition of both esterolytic hydrolysis of benzoyl-arginine ethyl ester on spectrophotometric analysis and proteolytic activity on gelatin SDS-PAGE zymography. DFP-labeled proteins were precipitated by highly specific antibodies to proacrosin. These results demonstrated that DFP is capable of inhibiting sperm function, and that it associates with the proacrosin-acrosin system in live motile sperm

Diisopropyl fluorophosphate labeling of sperm-associated proteinases

Energy Technology Data Exchange (ETDEWEB)

Odem, R.R.; Willand, J.L.; Polakoski, K.L. (Washington Univ. School of Medicine, St. Louis, MO (USA))

1990-02-01

Proteinase inhibitors have been shown to be capable of preventing various aspects of fertilization. Diisopropyl fluorophosphate (DFP) is an irreversible inhibitor of trypsin-like enzymes that is commercially available in a radiolabeled form. The experiments described herein were designed to determine if DFP would prevent sperm function in live, motile sperm and to identify the sperm proteins bound with DFP. DFP at 5 mM concentrations had no observable effect on sperm motility, but inhibited the penetration of zona-free hamster ova by human sperm (5.5%) compared to controls (33.5%). Acid extracts of motile sperm that had been incubated with radiolabeled DFP and collected by the swim-up procedure demonstrated the presence of radiolabeled DFP, and the autoradiography of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels of these extracts localized the uptake of radiolabeled DFP to proteins in the molecular weight region of the proacrosin-acrosin system. Acid-extracted proteinases from semen samples incubated with DFP demonstrated a concentration-dependent inhibition of both esterolytic hydrolysis of benzoyl-arginine ethyl ester on spectrophotometric analysis and proteolytic activity on gelatin SDS-PAGE zymography. DFP-labeled proteins were precipitated by highly specific antibodies to proacrosin. These results demonstrated that DFP is capable of inhibiting sperm function, and that it associates with the proacrosin-acrosin system in live motile sperm.

The effects of male age on sperm analysis by motile sperm organelle morphology examination (MSOME

Directory of Open Access Journals (Sweden)

Silva Liliane FI

2012-03-01

Full Text Available Abstract Background This study aimed to investigate the influence of age on sperm quality, as analysed by motile sperm organelle morphology examination (MSOME. Methods Semen samples were collected from 975 men undergoing evaluation or treatment for infertility. Sperm cells were evaluated at 8400× magnification using an inverted microscope equipped with Nomarski (differential interference contrast optics. Two forms of spermatozoa were considered: normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV, defined as vacuoles occupying > 50% of the sperm nuclear area. At least 200 spermatozoa per sample were evaluated, and the percentages of normal and LNV spermatozoa were determined. The subjects were divided into three groups according to age: Group I, less than or equal to 35 years; Group II, 36-40 years; and Group III, greater than or equal to 41 years. Results There was no difference in the percentages of normal sperm between the two younger (I and II groups (P >0.05. The percentage of normal sperm in the older group (III was significantly lower than that in the younger (I and II groups (P P >0.05. The percentage of LNV spermatozoa was significantly higher in the older group (III than in the younger (I and II groups (P P P Conclusion The results demonstrated a consistent decline in semen quality, as reflected by morphological evaluation by MSOME, with increased age. Considering the relationship between nuclear vacuoles and DNA damage, these age-related changes predict that increased paternal age should be associated with unsuccessful or abnormal pregnancy as a consequence of fertilisation with damaged spermatozoa. Given that sperm nuclear vacuoles can be evaluated more precisely at high magnification, these results support the routine use of MSOME for ICSI as a criterion for semen analysis.

Office-based sperm concentration: A simplified method for ...

African Journals Online (AJOL)

Methods: Semen samples from 51 sperm donors were used. Following swim-up separation, the sperm concentration of the retrieved motile fraction was counted, as well as progressive motile sperm using a standardised wet preparation. The number of sperm in a 10 μL droplet covered with a 22 × 22 mm coverslip was ...

Testicular sperm is superior to ejaculated sperm for ICSI in cryptozoospermia: An update systematic review and meta-analysis.

Science.gov (United States)

Kang, Yi-No; Hsiao, Ya-Wen; Chen, Chien-Yu; Wu, Chien-Chih

2018-05-18

Intracytoplasmic sperm injection (ICSI) is well established and provides patients with severely impaired sperm quality with an opportunity to father a child. However, previous studies do not clearly indicate whether male with cryptozoospermia should use testicular sperm or ejaculated sperm for ICSI. The newest systematic review of this topic also gave a controversial conclusion that was based on incorrect pooling result. Moreover, two clinical studies published after the systematic review. In the present update systematic review and meta-analysis, a comprehensive citation search for relevant studies was performed using the Cochrane library databases, Embase, Ovid MEDLINE, PubMed, ScienceDirect, Scopus, and Web of Science up to September 2017. The search returned 313 records, in which six studies were included in quantitative synthesis. These studies involved 578 male infertility patients who had undergone 761 ICSI cycles. The risk ratios favour fresh testicular sperm for good quality embryo rate (1.17, 95% CI 1.05-1.30, P = 0.005), implantation rate (95% CI 1.02-2.26, P = 0.04), and pregnancy rate (RR = 1.74, 95% CI 1.20-2.52, P = 0.004). In conclusion, the existing evidence suggests that testicular sperm is better than ejaculated sperm for ICSI in male with cryptozoospermia.

Anatomic Double-bundle ACL Reconstruction

NARCIS (Netherlands)

Schreiber, Verena M.; van Eck, Carola F.; Fu, Freddie H.

2010-01-01

Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee trauma. The traditional surgical treatment for ACL rupture is single-bundle reconstruction. However, during the past few years there has been a shift in interest toward double-bundle reconstruction to closely

Output commitment through product bundling : Experimental evidence

NARCIS (Netherlands)

Hinloopen, Jeroen; Mueller, Wieland; Normann, Hans-Theo

We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to

ACM Bundles on Del Pezzo surfaces

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Joan Pons-Llopis

2009-11-01

Full Text Available ACM rank 1 bundles on del Pezzo surfaces are classified in terms of the rational normal curves that they contain. A complete list of ACM line bundles is provided. Moreover, for any del Pezzo surface X of degree less or equal than six and for any n ≥ 2 we construct a family of dimension ≥ n − 1 of non-isomorphic simple ACM bundles of rank n on X.

Bundling and mergers in energy markets

International Nuclear Information System (INIS)

Granier, Laurent; Podesta, Marion

2010-01-01

Does bundling trigger mergers in energy industries? We observe mergers between firms belonging to various energy markets, for instance between gas and electricity providers. These mergers enable firms to bundle. We consider two horizontally differentiated markets. In this framework, we show that bundling strategies in energy markets create incentives to form multi-market firms in order to supply bi-energy packages. Moreover, we find that this type of merger is detrimental to social welfare. (author)

Sperm flagellum volume determines freezability in red deer spermatozoa.

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José Luis Ros-Santaella

Full Text Available The factors affecting the inter-individual differences in sperm freezability is a major line of research in spermatology. Poor sperm freezability is mainly characterised by a low sperm velocity, which in turn is associated with low fertility rates in most animal species. Studies concerning the implications of sperm morphometry on freezability are quite limited, and most of them are based on sperm head size regardless of the structural parts of the flagellum, which provides sperm motility. Here, for the first time, we determined the volumes of the flagellum structures in fresh epididymal red deer spermatozoa using a stereological method under phase contrast microscopy. Sperm samples from thirty-three stags were frozen and classified as good freezers (GF or bad freezers (BF at two hours post-thawing using three sperm kinetic parameters which are strongly correlated with fertility in this species. Fourteen stags were clearly identified as GF, whereas nineteen were BF. No significant difference in sperm head size between the two groups was found. On the contrary, the GF exhibited a lower principal piece volume than the BF (6.13 µm3 vs 6.61 µm3, respectively, p = 0.006. The volume of the flagellum structures showed a strong negative relationship with post-thawing sperm velocity. For instance, the volume of the sperm principal piece was negatively correlated with sperm velocity at two hours post-thawing (r = -0.60; p<0.001. Our results clearly show that a higher volume of the sperm principal piece results in poor freezability, and highlights the key role of flagellum size in sperm cryopreservation success.

Sperm motility and morphology as changing parameters linked to sperm count variations.

Directory of Open Access Journals (Sweden)

Dua A

1996-10-01

Full Text Available Variations in semen analyses of 177 males over a 1 year period were assessed. The average means of total counts, motility, morphology, total motile count and non-motile % were determined for 5 classes of patients ranging from azoospermic to normospermic. Positive relationships between a falling sperm count, a decrease in motility and total motile counts were seen. Also, increasingly, abnormal forms were found with lower sperm counts.

The different types of sperm morphology and behavior within a single species: Why do sperm of squid sneaker males form a cluster?

Science.gov (United States)

Hirohashi, Noritaka; Iwata, Yoko

2013-11-01

Some coastal squids exhibit male dimorphism (large and small body size) that is linked to mating behaviors. Large "consort" males compete with other, rival males to copulate with a female, and thereby transfer their spermatophores to her internal site around the oviduct. Small "sneaker" males rush to a single female or copulating pair and transfer spermatophores to her external body surface around the seminal receptacle near the mouth. We previously found that in Loligo bleekeri, sneaker sperm are ~50% longer than consort sperm, and only the sneaker sperm, once ejaculated from the spermatophore (sperm mass), form a cluster because of chemoattraction toward their own respiratory CO2. Here, we report that sperm clusters are able to move en masse. Because a fraction of ejaculated sperm from a sneaker's spermatophore are eventually located in the female's seminal receptacle, we hypothesize that sperm clustering facilitates collective migration to the seminal receptacle or an egg micropyle. Sperm clustering is regarded as a cooperative behavior that may have evolved by sperm competition and/or physical and physiological constraints imposed by male mating tactics.

Computational imaging through a fiber-optic bundle

Science.gov (United States)

Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

2017-05-01

Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

Glycolysis and mitochondrial respiration in mouse LDHC-null sperm.

Science.gov (United States)

Odet, Fanny; Gabel, Scott; London, Robert E; Goldberg, Erwin; Eddy, Edward M

2013-04-01

We demonstrated previously that a knockout (KO) of the lactate dehydrogenase type C (Ldhc) gene disrupted male fertility and caused a considerable reduction in sperm glucose consumption, ATP production, and motility. While that study used mice with a mixed genetic background, the present study used C57BL/6 (B6) and 129S6 (129) Ldhc KO mice. We found that B6 KO males were subfertile and 129 KO males were infertile. Sperm from 129 wild-type (WT) mice have a lower glycolytic rate than sperm from B6 WT mice, resulting in a greater reduction in ATP production in 129 KO sperm than in B6 KO sperm. The lower glycolytic rate in 129 sperm offered a novel opportunity to examine the role of mitochondrial respiration in sperm ATP production and motility. We observed that in media containing a mitochondrial substrate (pyruvate or lactate) as the sole energy source, ATP levels and progressive motility in 129 KO sperm were similar to those in 129 WT sperm. However, when glucose was added, lactate was unable to maintain ATP levels or progressive motility in 129 KO sperm. The rate of respiration (ZO2) was high when 129 KO or WT sperm were incubated with lactate alone, but addition of glucose caused a reduction in ZO2. These results indicate that in the absence of glucose, 129 sperm can produce ATP via oxidative phosphorylation, but in the presence of glucose, oxidative phosphorylation is suppressed and the sperm utilize aerobic glycolysis, a phenomenon known as the Crabtree effect.

Intracellular pH in sperm physiology.

Science.gov (United States)

Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

2014-08-01

Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. Copyright © 2014 Elsevier Inc. All rights reserved.

Cystic fibrosis transmembrane conductance regulator is correlated closely with sperm progressive motility and normal morphology in healthy and fertile men with normal sperm parameters.

Science.gov (United States)

Jiang, L-Y; Shan, J-J; Tong, X-M; Zhu, H-Y; Yang, L-Y; Zheng, Q; Luo, Y; Shi, Q-X; Zhang, S-Y

2014-10-01

Cystic fibrosis transmembrane conductance regulator (CFTR) has been demonstrated to be expressed in mature spermatozoa and correlated with sperm quality. Sperm CFTR expression in fertile men is higher than that in infertile men suffering from teratospermia, asthenoteratospermia, asthenospermia and oligospermia, but it is unknown whether CFTR is correlated with sperm parameters when sperm parameters are normal. In this study, 282 healthy and fertile men with normal semen parameters were classified into three age groups, group (I): age group of 20-29 years (98 cases, 27.1 ± 6.2), group (II): age group of 30-39 years (142 cases, 33.7 ± 2.6) and group (III): age group of more than or equal to 40 years (42 cases, 44.1 ± 4.6). Sperm concentration, total count and progressive motility were analysed by computer-assisted sperm analysis. Sperm morphology was analysed by modified Papanicolaou staining. Sperm CFTR expression was conducted by indirect immunofluorescence staining. There was a significant positive correlation (P sperm progressive motility (r = 0.221) and normal morphology (r = 0.202), but there were no correlations between sperm CFTR expression and semen volume, sperm concentration, sperm total count as well as male age (P > 0.05). Our findings show that CFTR expression is associated with sperm progressive motility and normal morphology in healthy and fertile men with normal sperm parameters, but not associated with the number of spermatozoa and male age. © 2013 Blackwell Verlag GmbH.

Reduction in sperm count and increase in abnormal sperm in the mouse following x-irradiation or injection of 22Na

International Nuclear Information System (INIS)

Harrison, A.; Moore, P.C.

1980-01-01

The accumulated reduction in sperm count and increase in the number of aberrant sperm in the mouse were used to compare acute X-irradiation with protracted radiation from an injection of 22 Na. The effects per unit of absorbed dose of acute and protracted radiation were similar on sperm count, but in respect of numbers of abnormal sperm the 22 Na induced a significantly greater maximum than X-rays. (author)

Standard-model bundles

CERN Document Server

Donagi, Ron; Pantev, Tony; Waldram, Dan; Donagi, Ron; Ovrut, Burt; Pantev, Tony; Waldram, Dan

2002-01-01

We describe a family of genus one fibered Calabi-Yau threefolds with fundamental group ${\\mathbb Z}/2$. On each Calabi-Yau $Z$ in the family we exhibit a positive dimensional family of Mumford stable bundles whose symmetry group is the Standard Model group $SU(3)\\times SU(2)\\times U(1)$ and which have $c_{3} = 6$. We also show that for each bundle $V$ in our family, $c_{2}(Z) - c_{2}(V)$ is the class of an effective curve on $Z$. These conditions ensure that $Z$ and $V$ can be used for a phenomenologically relevant compactification of Heterotic M-theory.

An in vitro biomechanical comparison of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

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Sandra Umeda Sasaki

2008-01-01

Full Text Available INTRODUCTION: Anterior cruciate ligament ruptures are frequent, especially in sports. Surgical reconstruction with autologous grafts is widely employed in the international literature. Controversies remain with respect to technique variations as continuous research for improvement takes place. One of these variations is the anatomical double bundle technique, which is performed instead of the conventional single bundle technique. More recently, there has been a tendency towards positioning the two bundles through double bone tunnels in the femur and tibia (anatomical reconstruction. OBJECTIVES: To compare, through biomechanical tests, the practice of anatomical double bundle anterior cruciate ligament reconstruction with a patellar graft to conventional single bundle reconstruction with the same amount of patellar graft in a paired experimental cadaver study. METHODS: Nine pairs of male cadaver knees ranging in age from 44 to 63 years were randomized into two groups: group A (single bundle and group B (anatomical reconstruction. Each knee was biomechanically tested under three conditions: intact anterior cruciate ligament, reconstructed anterior cruciate ligament, and injured anterior cruciate ligament. Maximum anterior dislocation, rigidity, and passive internal tibia rotation were recorded with knees submitted to a 100 N horizontal anterior dislocation force applied to the tibia with the knees at 30, 60 and 90 degrees of flexion. RESULTS: There were no differences between the two techniques for any of the measurements by ANOVA tests. CONCLUSION: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior with regard to anterior tibial dislocation, rigidity, and passive internal tibial rotation.

Reduction of symplectic principal R-bundles

International Nuclear Information System (INIS)

Lacirasella, Ignazio; Marrero, Juan Carlos; Padrón, Edith

2012-01-01

We describe a reduction process for symplectic principal R-bundles in the presence of a momentum map. These types of structures play an important role in the geometric formulation of non-autonomous Hamiltonian systems. We apply this procedure to the standard symplectic principal R-bundle associated with a fibration π:M→R. Moreover, we show a reduction process for non-autonomous Hamiltonian systems on symplectic principal R-bundles. We apply these reduction processes to several examples. (paper)

Bundles of C*-categories and duality

OpenAIRE

Vasselli, Ezio

2005-01-01

We introduce the notions of multiplier C*-category and continuous bundle of C*-categories, as the categorical analogues of the corresponding C*-algebraic notions. Every symmetric tensor C*-category with conjugates is a continuous bundle of C*-categories, with base space the spectrum of the C*-algebra associated with the identity object. We classify tensor C*-categories with fibre the dual of a compact Lie group in terms of suitable principal bundles. This also provides a classification for ce...

Sperm Na+, K+-ATPase and Ca2+-ATPase activity: A preliminary study of comparison of swim up and density gradient centrifugation methods for sperm preparation

Science.gov (United States)

Lestari, Silvia W.; Larasati, Manggiasih D.; Asmarinah, Mansur, Indra G.

2018-02-01

As one of the treatment for infertility, the success rate of Intrauterine Insemination (IUI) is still relatively low. Several sperm preparation methods, swim-up (SU) and the density-gradient centrifugation (DGC) are frequently used to select for better sperm quality which also contribute to IUI failure. Sperm selection methods mainly separate the motile from the immotile sperm, eliminating the seminal plasma. The sperm motility involves the structure and function of sperm membrane in maintaining the balance of ion transport system which is regulated by the Na+, K+-ATPase, and Ca2+-ATPase enzymes. This study aims to re-evaluate the efficiency of these methods in selecting for sperm before being used for IUI and based the evaluation on sperm Na+,K+-ATPase and Ca2+-ATPase activities. Fourteen infertile men from couples who underwent IUI were involved in this study. The SU and DGC methods were used for the sperm preparation. Semen analysis was performed based on the reference value of World Health Organization (WHO) 2010. After isolating the membrane fraction of sperms, the Na+, K+-ATPase activity was defined as the difference in the released inorganic phosphate (Pi) with and without the existence of 10 mM ouabain in the reaction, while the Ca2+-ATPase was determined as the difference in Pi contents with and without the existence of 55 µm CaCl2. The prepared sperm demonstrated a higher percentage of motile sperm compared to sperm from the whole semen. Additionally, the percentage of motile sperm of post-DGC showed higher result than the sperm from post-SU. The velocity of sperm showed similar pattern with the percentage of motile sperm, in which the velocity of prepared sperm was higher than the sperm from whole semen. Furthermore, the sperm velocity of post-DGC was higher compared to the sperm from post-SU. The Na+, K+-ATPase activity of prepared sperm was higher compared to whole semen, whereas Na+, K+-ATPase activity in the post DGC was higher than post SU. The Ca2

Evaluating big deal journal bundles.

Science.gov (United States)

Bergstrom, Theodore C; Courant, Paul N; McAfee, R Preston; Williams, Michael A

2014-07-01

Large commercial publishers sell bundled online subscriptions to their entire list of academic journals at prices significantly lower than the sum of their á la carte prices. Bundle prices differ drastically between institutions, but they are not publicly posted. The data that we have collected enable us to compare the bundle prices charged by commercial publishers with those of nonprofit societies and to examine the types of price discrimination practiced by commercial and nonprofit journal publishers. This information is of interest to economists who study monopolist pricing, librarians interested in making efficient use of library budgets, and scholars who are interested in the availability of the work that they publish.

Dimensional measurement of fresh fuel bundle for CANDU reactor

International Nuclear Information System (INIS)

Jo, Chang Keun; Cho, Moon Sung; Suk, Ho Chun; Koo, Dae Seo; Jun, Ji Su; Jung, Jong Yeob

2005-01-01

This report describes the results of the dimensional measurement of fresh fuel bundles for the CANDU reactor in order to estimate the integrity of fuel bundle in two-phase flow in the CANDU-6 fuel channel. The dimensional measurements of fuel bundles are performed by using the 'CANDU Fuel In-Bay Inspection and Dimensional Measurement System', which was developed by this project. The dimensional measurements are done from February 2004 to March 2004 in the CANDU fuel storage of KNFC for the 36 fresh fuel bundles, which are produced by KNFC and are waiting for the delivery to the Wolsong-3 plant. The detail items of dimensional measurements are included fuel rod and bearing pad profiles of the outer ring in fuel bundle, diameter of fuel bundle, bowing of fuel bundle, fuel rod length, and surface profile of end plate profile. The measurement data will be compared with those of the post-irradiated bundles cooled in Wolsong-3 NPP spent fuel pool by using the same bundles and In-Bay Measurement System. So, this analysis of data will be applied for the evaluation of fuel bundle integrity in two-phase flow of the CANDU-6 fuel channel

Sasakian and Parabolic Higgs Bundles

Science.gov (United States)

Biswas, Indranil; Mj, Mahan

2018-03-01

Let M be a quasi-regular compact connected Sasakian manifold, and let N = M/ S 1 be the base projective variety. We establish an equivalence between the class of Sasakian G-Higgs bundles over M and the class of parabolic (or equivalently, ramified) G-Higgs bundles over the base N.

Fuel bundle movement due to reverse flow

Energy Technology Data Exchange (ETDEWEB)

Wahba, N N; Akalin, O [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

When a break occurs in the inlet feeder or inlet header, the rapid depressurization will cause the channel flow to reverse forcing the string of bundles to accelerate and impact with upstream shield plug. A model has been developed to predict the bundle motion due to the channel flow reversal. The model accounts for various forces acting on the bundle. A series of five reverse flow, bundle acceleration experiments have been conducted simulating a break in the inlet feeder of a CANDU fuel channel. The model has been validated against the experiments. The predicted impact velocities are in good agreement with the measured values. It is demonstrated that the model may be successfully used in predicting bundle relocation timing following a large LOCA (loss of coolant). (author). 7 refs., 3 tabs., 11 figs.

Bundles over Quantum RealWeighted Projective Spaces

Directory of Open Access Journals (Sweden)

Tomasz Brzeziński

2012-09-01

Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.

Sperm cryopreservation in fish and shellfish.

Science.gov (United States)

Tiersch, Terrence R; Yang, Huiping; Jenkins, Jill A; Dong, Qiaoxiang

2007-01-01

Initial success in sperm cryopreservation came at about the same time for aquatic species and livestock. However, in the 50-plus years since then cryopreserved sperm of livestock has grown into a billion-dollar global industry, while despite work in some 200 species with well over 200 published reports, cryopreservation of aquatic species sperm remains essentially a research activity with little commercial application. Most research has focused on large-bodied culture and sport fishes, such as salmonids, carps, and catfishes, and mollusks such as commercially important oyster and abalone species. However, only a handful of studies have addressed sperm cryopreservation in small fishes, such as zebrafish, and in endangered species. Overall, this work has yielded techniques that are being applied with varying levels of success around the world. Barriers to expanded application include a diverse and widely distributed literature base, technical problems, small sperm volumes, variable results, a general lack of access to the technology, and most importantly, the lack of standardization in practices and reporting. The benefits of cryopreservation include at least five levels of improvements for existing industries and for creation of new industries. First, cryopreservation can be used to improve existing hatchery operations by providing sperm on demand and simplifying the timing of induced spawning. Second, frozen sperm can enhance efficient use of facilities and create new opportunities in the hatchery by eliminating the need to maintain live males, potentially freeing resources for use with females and larvae. Third, valuable genetic lineages such as endangered species, research models, or improved farmed strains can be protected by storage of frozen sperm. Fourth, cryopreservation opens the door for rapid genetic improvement. Frozen sperm can be used in breeding programs to create improved lines and shape the genetic resources available for aquaculture. Finally

21 CFR 173.275 - Hydrogenated sperm oil.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogenated sperm oil. 173.275 Section 173.275... CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.275 Hydrogenated sperm oil. The food additive hydrogenated sperm oil may be safely used in accordance with the following prescribed...

COMP-1 promotes competitive advantage of nematode sperm.

Science.gov (United States)

Hansen, Jody M; Chavez, Daniela R; Stanfield, Gillian M

2015-03-19

Competition among sperm to fertilize oocytes is a ubiquitous feature of sexual reproduction as well as a profoundly important aspect of sexual selection. However, little is known about the cellular mechanisms sperm use to gain competitive advantage or how these mechanisms are regulated genetically. In this study, we utilize a forward genetic screen in Caenorhabditis elegans to identify a gene, comp-1, whose function is specifically required in competitive contexts. We show that comp-1 functions in sperm to modulate their migration through and localization within the reproductive tract, thereby promoting their access to oocytes. Contrary to previously described models, comp-1 mutant sperm show no defects in size or velocity, thereby defining a novel pathway for preferential usage. Our results indicate not only that sperm functional traits can influence the outcome of sperm competition, but also that these traits can be modulated in a context-dependent manner depending on the presence of competing sperm.

An automatic system to study sperm motility and energetics.

Science.gov (United States)

Shi, Linda Z; Nascimento, Jaclyn M; Chandsawangbhuwana, Charlie; Botvinick, Elliot L; Berns, Michael W

2008-08-01

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membrane potential) using real-time tracking (done by the upper-level system) and fluorescent ratio imaging (done by the lower-level system). The communication between these two systems is achieved by a gigabit network. The custom-built image processing algorithm identifies the sperm swimming trajectory in real-time using phase contrast images, and then subsequently traps the sperm by automatically moving the microscope stage to relocate the sperm to the laser trap focal plane. Once the sperm is stably trapped (determined by the algorithm), the algorithm can also gradually reduce the laser power by rotating the polarizer in the laser path to measure the trapping power at which the sperm is capable of escaping the trap. To monitor the membrane potential of the mitochondria located in a sperm's mid-piece, the sperm is treated with a ratiometrically-encoded fluorescent probe. The proposed algorithm can relocate the sperm to the center of the ratio imaging camera and the average ratio value can be measured in real-time. The three parameters, sperm escape power, sperm swimming speed and ratio values of the mid-piece membrane potential of individual sperm can be compared with respect to time. This two-level automatic system to study individual sperm motility and energetics has not only increased experimental throughput by an order of magnitude but also has allowed us to monitor sperm energetics prior to and after exposure to the laser trap. This system should have application in both the

Dynamic behaviour of FBR fuel pin bundles

International Nuclear Information System (INIS)

Martin, P.H.; Van Dorsselaere, J.P.; Ravenet, A.

1990-01-01

A programme of shock tests on a fast neutron reactor subassembly model (SPX1 geometry) including a complete bundle of fuel pins (dummy elements) is being carried out in the BELIER test facility at Cadarache. The purpose of these tests is: to determine the distribution of dynamic forces applied to the fuel rod clads under the impact conditions encountered in a reactor during a earthquake; to reduce as much as possible the conservatism of the methods presently used for the calculation of those forces. The test programme, now being completed, consists of the following steps: impacts on the mock-up in air with an non-compact bundle (situation of the subassembly at beginning of life (BOL) with clearances within the bundle); impacts under the same conditions but with fluid (water) in the subassembly; impacts on the mock-up in air and with a compacted bundle (simulating the conditions of an end-of-life (EOL) bundle with no clearance within the bundle). The accelerations studied in these tests cover the range encountered in design calculations for the subassembly frequencies in beam mode. (author)

The Semen pH Affects Sperm Motility and Capacitation.

Science.gov (United States)

Zhou, Ji; Chen, Li; Li, Jie; Li, Hongjun; Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

2015-01-01

As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na(+)/K(+)-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2(+ )concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na(+)/K(+)-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility.

Localized accumulation of cytosolic calcium near the fused sperm is associated with the calcium- and voltage-dependent block of sperm entry in the sea urchin egg.

Science.gov (United States)

Ivonnet, Pedro I; Mohri, Tatsuma; McCulloh, David H

2017-10-01

Interaction of the sperm and egg depolarizes the egg membrane, allowing the sperm to enter; however, if the egg membrane is not allowed to depolarize from its resting potential (e.g., by voltage-clamp), the sperm will not enter. Previous studies demonstrated that sperm entry into sea urchin eggs that are voltage-clamped at negative membrane potentials is regulated both by the egg's membrane potential and a voltage-dependent influx of calcium into the egg. In these cases, electrical or cytoplasmic continuity (sperm-egg membrane fusion) occurs at negative membrane potentials, but subsequent loss of cytoplasmic continuity results in failure of sperm entry (unfusion). The work presented herein examined where, in relation to the sperm, and when, in relation to the sperm-induced electrophysiological events, the egg's calcium influx occurs, and how these events relate to successful or failed sperm entry. When sperm entered the egg, elevation of intracellular calcium concentration ([Ca 2+ ] i ) began near the fused sperm on average 5.9 s after sperm-egg membrane fusion. Conversely, when sperm failed to enter the egg, [Ca 2+ ] i elevated near the site of sperm-egg fusion on average 0.7 s after sperm-egg membrane fusion, which is significantly earlier than in eggs for which sperm entered. Therefore, the accumulation of calcium near the site of sperm-egg fusion is spatially and temporally consistent with the mechanism that may be responsible for loss of cytoplasmic continuity and failure of sperm entry. © 2017 Wiley Periodicals, Inc.

Tolerance to environmental desiccation in moss sperm.

Science.gov (United States)

Shortlidge, Erin E; Rosenstiel, Todd N; Eppley, Sarah M

2012-05-01

• Sexual reproduction in mosses requires that sperm be released freely into the environment before finding and fertilizing a receptive female. After release from the male plant, moss sperm may experience a range of abiotic stresses; however, few data are available examining stress tolerance of moss sperm and whether there is genetic variation for stress tolerance in this important life stage. • Here, we investigated the effects of environmental desiccation and recovery on the sperm cells of three moss species (Bryum argenteum, Campylopus introflexus, and Ceratodon purpureus). • We found that a fraction of sperm cells were tolerant to environmental desiccation for extended periods (d) and that tolerance did not vary among species. We found that this tolerance occurs irrespective of ambient dehydration conditions, and that the addition of sucrose during dry-down improved cell recovery. Although we observed no interspecific variation, significant variation among individuals within species in sperm cell tolerance to environmental desiccation was observed, suggesting selection could potentially act on this basic reproductive trait. • The observation of desiccation-tolerant sperm in multiple moss species has important implications for understanding bryophyte reproduction, suggesting the presence of a significant, uncharacterized complexity in the ecology of moss mating systems. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

MONTHLY VARIATION IN SPERM MOTILITY IN COMMON CARP ASSESSED USING COMPUTER-ASSISTED SPERM ANALYSIS (CASA)

Science.gov (United States)

Sperm motility variables from the milt of the common carp Cyprinus carpio were assessed using a computer-assisted sperm analysis (CASA) system across several months (March-August 1992) known to encompass the natural spawning period. Two-year-old pond-raised males obtained each mo...

Leukocytospermia and sperm preparation - a flow cytometric study

Directory of Open Access Journals (Sweden)

Perticarari Sandra

2009-01-01

Full Text Available Abstract Background Leukocytes represent the predominant source of reactive oxygen species both in seminal plasma and in sperm suspensions and have been demonstrated to negatively influence sperm function and fertilization rate in assisted reproduction procedures. Peroxidase test is the standard method recommended by WHO to detect semen leukocytes but it may be inaccurate. The aims of this study were (i to compare the efficiency of swim-up and density-gradient centrifugation techniques in removing seminal leukocytes, (ii to examine the effect of leukocytes on sperm preparation, and (iii to compare flow cytometry and peroxidase test in determining leukocyte concentration in semen using a multiparameter flow cytometric method. Methods Semen samples from 126 male partners of couples undergoing infertility investigations were analyzed for leukocytospermia using standard optical microscopy and flow cytometry. Sixty-nine out of 126 samples were also processed using simultaneously the swim-up and density-gradient centrifugation techniques. A multiparameter flow cytometric analysis to assess simultaneously sperm concentration, sperm viability, sperm apoptosis, and leukocyte concentration was carried out on neat and prepared sperm. Results Both sperm preparation methods removed most seminal leukocytes. However, the concentration of leukocytes was significantly lower after swim-up compared to that after density-gradient centrifugation preparation. Leukocytes concentration, either initial or in prepared fractions, was not correlated with sperm parameters (optical microscopy and flow cytometry parameters after semen processing. There was no correlation between leukocyte concentration in the ejaculate and sperm recovery rate, whereas a significant correlation was found between the concentration of the residual leukocytes in prepared fractions and viable sperm recovery rate. Although the overall concordance between the flow cytometry and the optical

Sperm storage induces an immunity cost in ants

DEFF Research Database (Denmark)

Baer, Boris; Armitage, Sophie A O; Boomsma, Jacobus J

2006-01-01

Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known...... what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow...

Fuel temperature characteristics of the 37-element and CANFLEX fuel bundle

International Nuclear Information System (INIS)

Bae, Jun Ho; Rho, Gyu Hong; Park, Joo Hwan

2009-10-01

This report describes the fuel temperature characteristics of CANFLEX fuel bundles and 37-element fuel bundles for a different burnup of fuel. The program was consisted for seeking the fuel temperature of fuel bundles of CANFLEX fuel bundles and 37-element fuel bundles by using the method in NUCIRC. Fuel temperature has an increasing pattern with the burnup of fuel for CANFLEX fuel bundles and 37-element fuel bundles. For all the case of burnup, the fuel temperature of CANFLEX fuel bundles has a lower value than that of 37-element fuel bundles. Especially, for the high power channel, the CANFLEX fuel bundles show a lower fuel temperature as much as about 75 degree, and the core averaged fuel temperature has a lower fuel temperature of about 50 degree than that of 37-element fuel bundles. The lower fuel temperature of CANFLEX fuel bundles is expected to enhance the safety by reducing the fuel temperature coefficient. Finally, for each burnup of CANFLEX fuel bundles and 37-element fuel bundles, the equation was present for predicting the fuel temperature of a bundle in terms of a coolant temperature and bundle power

Radiolabelling of sperm cells with 99mTc-HMPAO. In vivo visualization of sperm cell migration in rabbits

International Nuclear Information System (INIS)

Bockisch, A.; Tennessee Univ., Knoxville, TN; Tennessee Univ., Knoxville, TN; Al-Hasani, S.; Ven, H.V.D.; Diedrich, K.; Krebs, D.; Posch, C.; Hotze, A.; Biersack, H.J.

1989-01-01

The present paper is the first descriptive radiolabeling of sperm cells in order to visualize their in vivo migration and imaging by scintigraphic technique, 99m Tc-HMPAO was used which combines favourable characteristics of both imaging modalities and radiation exposure. The radiolabeling yield was optimised for human sperm cells, and was increasing with the number of sperm cells, the amount of HMPAO, the 99m Tc-HMPAO concentration and the duration of the incubation. Incubation periods greater than 20 min, however, resulted only in a minor increase of labeling yield. A delay of more than 5 min between the labeling of the HMPAO with 99m Tc and initiation of the incubation of the sperm cells with the 99m Tc-HMPAO also decreased the maximum labeling yield. The radiolabeled cells were found to be stable and after 18 h > 93% of the activity was still bound to the sperm cells. After insemination of labeled sperm cells in ovulating rabbits the accumulation of the cells in the Fallopian tubes and their subsequent migration could be clearly visualized by scintigraphic techniques in vivo. (orig.) [de

Epididymal sperm from Spix's yellow-toothed cavies sperm successfully cryopreserved in Tris extender with 6% glycerol and 20% egg yolk.

Science.gov (United States)

Silva, Andréia M; Praxedes, Erica C G; Campos, Lívia B; Bezerra, Luana G P; Moreira, Samara S J; Maia, Keilla M; Souza, Ana L P; Silva, Alexandre R

2018-04-01

As a non-threatened hystricognath rodent species, Spix's yellow-toothed cavies can be used as a model for the development of assisted reproductive techniques for the conservation of closely related species. The objective was to establish a functional protocol for cryopreservation of epididymal sperm from these cavies. Twelve sexually mature males, ∼2 y old and weighing ∼300 g, were euthanized. Sperm were recovered by retrograde flushing of the vas deferens and cauda epididymis with Tris extender. Thereafter, sperm were extended in Tris plus 20% egg yolk, with 3%, 6% or 9% glycerol or dimethyl sulfoxide (DMSO), placed in 0.25 mL straws and cryopreserved in liquid nitrogen. Sperm concentration, motility (using computer-assisted sperm analysis; CASA), plasma membrane integrity, osmotic response, morphology and sperm binding-ability were determined in fresh and frozen-thawed sperm. For most sperm endpoints, glycerol was a more desirable cryoprotectant than DMSO. Data (mean ± SEM) were similar with use of 3%, 6%, and 9% glycerol (P > 0.05) in osmotic response (40.66 ± 6.3%, 42.5 ± 7.1%, and 39.5 ± 5.0% respectably), and membrane integrity (55.17 ± 5.5%, 68.4 ± 4.1%, and 59.1 ± 4.9% respectably). Among concentrations assessed, the use of 6% glycerol resulted in the greatest (P < 0.05) post-thaw values for total motility (60.9 ± 4.4%), rapid subpopulation motility (27.7 ± 3.1%) and sperm-binding capability (227.0 ± 20.2). In conclusion, epididymal sperm from the Spix's yellow-toothed cavies (G. spixii) are optimally cryopreserved in Tris extender with 6% glycerol and 20% egg yolk. Copyright © 2018 Elsevier B.V. All rights reserved.

Episodic payments (bundling): PART I.

Science.gov (United States)

Jacofsky, D J

2017-10-01

Episodic, or bundled payments, is a concept now familiar to most in the healthcare arena, but the models are often misunderstood. Under a traditional fee-for-service model, each provider bills separately for their services which creates financial incentives to maximise volumes. Under a bundled payment, a single entity, often referred to as a convener (maybe the hospital, the physician group, or a third party) assumes the risk through a payer contract for all services provided within a defined episode of care, and receives a single (bundled) payment for all services provided for that episode. The time frame around the intervention is variable, but defined in advance, as are included and excluded costs. Timing of the actual payment in a bundle may either be before the episode occurs (prospective payment model), or after the end of the episode through a reconciliation (retrospective payment model). In either case, the defined costs over the defined time frame are borne by the convener. Cite this article: Bone Joint J 2017;99-B:1280-5. ©2017 The British Editorial Society of Bone & Joint Surgery.

Equilibrium polyelectrolyte bundles with different multivalent counterion concentrations

Science.gov (United States)

Sayar, Mehmet; Holm, Christian

2010-09-01

We present the results of molecular-dynamics simulations on the salt concentration dependence of the formation of polyelectrolyte bundles in thermodynamic equilibrium. Extending our results on salt-free systems we investigate here deficiency or excess of trivalent counterions in solution. Our results reveal that the trivalent counterion concentration significantly alters the bundle size and size distribution. The onset of bundle formation takes place at earlier Bjerrum length values with increasing trivalent counterion concentration. For the cases of 80%, 95%, and 100% charge compensation via trivalent counterions, the net charge of the bundles decreases with increasing size. We suggest that competition among two different mechanisms, counterion condensation and merger of bundles, leads to a nonmonotonic change in line-charge density with increasing Bjerrum length. The investigated case of having an abundance of trivalent counterions by 200% prohibits such a behavior. In this case, we find that the difference in effective line-charge density of different size bundles diminishes. In fact, the system displays an isoelectric point, where all bundles become charge neutral.

A new approach to sperm preservation based on bioenergetic theory.

Science.gov (United States)

Froman, D P; Feltmann, A J

2010-04-01

To date, attempts to preserve chicken sperm have been based on a trial-and-error experimental approach. The present work outlines the development of an alternative approach based on empiricism and bioenergetic theory. In previous work, we found fowl sperm motility to be dependent on mitochondrial calcium cycling, phospholipase A(2), and long-chain fatty acids as an endogenous energy source. It is noteworthy that fowl sperm reside within the sperm storage tubules (SST) of the oviduct over an interval of days to weeks after insemination. In this regard, a model for in vivo sperm storage was developed and tested in additional previous research. Sperm penetration of the SST, sperm residence within the SST, and sperm egress from the SST can be explained in terms mitochondrial function. Understanding sperm function and longevity in terms of bioenergetics presented the possibility that sperm could be inactivated by disrupting mitochondrial calcium cycling and could thereby be preserved. However, this possibility also posed a problem: maintenance of the inner membrane potential of the mitochondrion within inactivated sperm. This report describes a series of experiments in which fowl sperm were inactivated by treatment with the calcium chelator tetrasodium 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, and then reactivated by treatment with calcium ions. The effect of tetrasodium 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid on mitochondrial calcium cycling was confirmed by flow cytometry and confocal microscopy. When treated sperm were cooled to 10 degrees C, inactivated sperm could be reactivated throughout a 5-h storage interval. When stored sperm were held for 3 h before reactivation and insemination, fertility was 88% of the control. Storage did not affect hatchability. In summary, short-term storage was realized by manipulating mitochondrial function. We propose that 1) complex V consumes ATP within inactivated sperm and, by doing so, maintains

Effect of sperm concentration on characteristics and fertilization capacity of rooster sperm frozen in the presence of the antioxidants catalase and vitamin E.

Science.gov (United States)

Moghbeli, Morteza; Kohram, Hamid; Zare-Shahaneh, Ahmad; Zhandi, Mahdi; Sharideh, Hossein; Sharafi, Mohsen

2016-10-01

The objective of this study conducted was to determine the influence of different levels of sperm concentration, including catalase (CAT) and vitamin E (VitE) in rooster semen extender on postthawed quality and fertility of rooster semen. Semen was collected twice a week from six roosters (Arian) and diluted according to experimental treatments consisting of sperm suspensions containing different sperm concentrations (200, 400, and 600 × 106 sperm/mL) without antioxidant supplementation as control (Con) groups (Con200, Con400, and Con600, respectively), sperm suspensions containing different sperm concentrations (200, 400, and 600 × 106 sperm/mL) supplemented with 5-μg/mL VitE (VitE200, VitE400, and VitE600, respectively) and different sperm concentrations (200, 400, and 600 × 106 sperm/mL) supplementation with 100 IU/mL CAT (CAT200, CAT400, and CAT600, respectively). After thawing; sperm motility, membrane integrity, and mitochondrial function were assessed. Fertility and hatchability rates were determined by using 100 artificially inseminated hens. The percentage of total motility (TM) and activity of mitochondria decreased (P rooster extender with different level sperm concentrations had no effect (P > 0.05) on fertility and hatchability rates. In conclusion, although adding VitE and CAT in extender with different levels of sperm concentration improved postthawed quality of rooster semen, but adding VitE and CAT in the extender have no effect on fertility rate. Copyright © 2016 Elsevier Inc. All rights reserved.

Sperm cryopreservation in live-bearing Xiphophorus fishes: offspring production from Xiphophorus variatus and strategies for establishment of sperm repositories.

Science.gov (United States)

Yang, Huiping; Cuevas-Uribe, Rafael; Savage, Markita G; Walter, Ronald B; Tiersch, Terrence R

2012-09-01

Cryopreservation of sperm from Xiphophorus fishes has produced live young in three species: X. hellerii, X. couchianus, and X. maculatus. In this study, the goal was to establish protocols for sperm cryopreservation and artificial insemination to produce live young in X. variatus, and to identify needs for repository development. The objectives were to: 1) collect basic biological characteristics of males; 2) cryopreserve sperm from X. variatus, 3) harvest live young from cryopreserved sperm, and 4) discuss the requirements for establishment of sperm repositories. The 35 males used in this study had a body weight of 0.298±0.096 g (mean±SD), body length of 2.5±0.2 cm, and testis weight of 6.4±3.4 mg. The sperm production per gram of testis was 2.33±1.32×10(9) cells. After freezing, the post-thaw motility decreased significantly to 37%±17% (ranging from 5% to 70%) (p=0.000) from 57%±14% (40%-80%) of fresh sperm (N=20). Artificial insemination of post-thaw sperm produced confirmed offspring from females of X. hellerii and X. variatus. This research, taken together with previous studies, provides a foundation for development of strategies for sperm repositories of Xiphophorus fishes. This includes: 1) the need for breeding strategies for regeneration of target populations, 2) identification of minimum fertilization capacity of frozen samples, 3) identification of fish numbers necessary for sampling and their genetic relationships, 4) selection of packaging containers for labeling and biosecurity, 5) assurance of quality control and standardization of procedures, 6) information systems that can manage the data associated with cryopreserved samples, including the genetic data, 7) biological data of sampled fish, 8) inventory data associated with frozen samples, and 9) data linking germplasm samples with other related materials such as body tissues or cells saved for DNA and RNA analyses.

[Eosin Y-water test for sperm function examination].

Science.gov (United States)

Zha, Shu-wei; Lü, Nian-qing; Xu, Hao-qin

2015-06-01

Based on the principles of the in vitro staining technique, hypotonic swelling test, and water test, the Eosin Y-water test method was developed to simultaneously detect the integrity of the sperm head and tail and sperm membrane structure and function. As a widely used method in clinical laboratories in China, the Eosin Y-water test is methodologically characterized by three advantages. Firstly, both the sperm head and tail can be detected at the same time, which allows easy and comprehensive assessment of membrane damage in different parts of sperm. Secondly, distilled water is used instead of the usual formula solution to simplify and standardize the test by eliminating any potential effects on the water molecules through the sperm membrane due to different osmotic pressure or different sugar proportions and electrolyte solutions. Thirdly, the test takes less time and thus can be repeated before and after treatment. This article focuses on the fundamental principles and modification of the Eosin Y-water test and its application in sperm function examination and routine semen analysis for male infertility, assessment of the quality of sperm retrieved by testicular fine needle aspiration, semen cryopreservation program development, and evaluation of sperm membrane integrity after microwave radiation.

COMP-1 promotes competitive advantage of nematode sperm

Science.gov (United States)

Hansen, Jody M; Chavez, Daniela R; Stanfield, Gillian M

2015-01-01

Competition among sperm to fertilize oocytes is a ubiquitous feature of sexual reproduction as well as a profoundly important aspect of sexual selection. However, little is known about the cellular mechanisms sperm use to gain competitive advantage or how these mechanisms are regulated genetically. In this study, we utilize a forward genetic screen in Caenorhabditis elegans to identify a gene, comp-1, whose function is specifically required in competitive contexts. We show that comp-1 functions in sperm to modulate their migration through and localization within the reproductive tract, thereby promoting their access to oocytes. Contrary to previously described models, comp-1 mutant sperm show no defects in size or velocity, thereby defining a novel pathway for preferential usage. Our results indicate not only that sperm functional traits can influence the outcome of sperm competition, but also that these traits can be modulated in a context-dependent manner depending on the presence of competing sperm. DOI: http://dx.doi.org/10.7554/eLife.05423.001 PMID:25789512

Parallel Evolution of Sperm Hyper-Activation Ca2+ Channels.

Science.gov (United States)

Cooper, Jacob C; Phadnis, Nitin

2017-07-01

Sperm hyper-activation is a dramatic change in sperm behavior where mature sperm burst into a final sprint in the race to the egg. The mechanism of sperm hyper-activation in many metazoans, including humans, consists of a jolt of Ca2+ into the sperm flagellum via CatSper ion channels. Surprisingly, all nine CatSper genes have been independently lost in several animal lineages. In Drosophila, sperm hyper-activation is performed through the cooption of the polycystic kidney disease 2 (pkd2) Ca2+ channel. The parallels between CatSpers in primates and pkd2 in Drosophila provide a unique opportunity to examine the molecular evolution of the sperm hyper-activation machinery in two independent, nonhomologous calcium channels separated by > 500 million years of divergence. Here, we use a comprehensive phylogenomic approach to investigate the selective pressures on these sperm hyper-activation channels. First, we find that the entire CatSper complex evolves rapidly under recurrent positive selection in primates. Second, we find that pkd2 has parallel patterns of adaptive evolution in Drosophila. Third, we show that this adaptive evolution of pkd2 is driven by its role in sperm hyper-activation. These patterns of selection suggest that the evolution of the sperm hyper-activation machinery is driven by sexual conflict with antagonistic ligands that modulate channel activity. Together, our results add sperm hyper-activation channels to the class of fast evolving reproductive proteins and provide insights into the mechanisms used by the sexes to manipulate sperm behavior. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Percoll gradient-centrifuged capacitated mouse sperm have increased fertilizing ability and higher contents of sulfogalactosylglycerolipid and docosahexaenoic acid-containing phosphatidylcholine compared to washed capacitated mouse sperm.

Science.gov (United States)

Furimsky, Anna; Vuong, Ngoc; Xu, Hongbin; Kumarathasan, Premkumari; Xu, Min; Weerachatyanukul, Wattana; Bou Khalil, Maroun; Kates, Morris; Tanphaichitr, Nongnuj

2005-03-01

Although Percoll gradient centrifugation has been used routinely to prepare motile human sperm, its use in preparing motile mouse sperm has been limited. Here, we showed that Percoll gradient-centrifuged (PGC) capacitated mouse sperm had markedly higher fertilizing ability (sperm-zona pellucida [ZP] binding and in vitro fertilization) than washed capacitated mouse sperm. We also showed that the lipid profiles of PGC capacitated sperm and washed capacitated sperm differed significantly. The PGC sperm had much lower contents of cholesterol and phospholipids. This resulted in relative enrichment of male germ cell-specific sulfogalactosylglycerolipid (SGG), a ZP-binding ligand, in PGC capacitated sperm, and this would explain, in part, their increased ZP-binding ability compared with that of washed capacitated sperm. Analyses of phospholipid fatty acyl chains revealed that PGC capacitated sperm were enriched in phosphatidylcholine (PC) molecular species containing highly unsaturated fatty acids (HUFAs), with docosahexaenoic acid (DHA; C22: 6n-3) being the predominant HUFA (42% of total hydrocarbon chains of PC). In contrast, the level of PC-HUFAs comprising arachidonic acid (20:4n-6), docosapentaenoic acid (C22:5n-6), and DHA in washed capacitated sperm was only 27%. Having the highest unsaturation degree among all HUFAs in PC, DHA would enhance membrane fluidity to the uppermost. Therefore, membranes of PGC capacitated sperm would undergo fertilization-related fusion events at higher rates than washed capacitated sperm. These results suggested that PGC mouse sperm should be used in fertilization experiments and that SGG and DHA should be considered to be important biomarkers for sperm fertilizing ability.

Annular burnout data from rod-bundle experiments

International Nuclear Information System (INIS)

Yoder, G.L.; Morris, D.G.; Mullins, C.B.

1983-01-01

Burnout data for annular flow in a rod bundle are presented for both transient and steady-state conditions. Tests were performed at the Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF), a pressurized-water loop containing an electrically heated 64-rod bundle. The bundle configuration is typical of later generation pressurized-water reactors with 17 x 17 fuel arrays. Both axial and radial power profiles are flat. All experiments were carried out in upflow with subcooled inlet conditions, insuring accurate flow measurement. Conditions within the bundle were typical of those which could be encountered during a nuclear reactor loss-of-coolant accident

Evolutionary genetics and ecology of sperm-dependent parthenogenesis

NARCIS (Netherlands)

Beukeboom, L.W.; Vrijenhoek, R.C.

1998-01-01

Sperm-dependent (or pseudogamous) forms of parthenogenetic reproduction occur in a wide variety of animals. Inheritance is typically clonal and matroclinous (of female descent), but sperm are needed to initiate normal development. As opposed to true parthenogenesis (i.e., sperm-independent

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.

Short communication Relationship between sperm plasma ...

African Journals Online (AJOL)

Matshidiso MB. Masenya

2017-01-04

Jan 4, 2017 ... observed between sperm plasma membrane integrity and fertility. There was a weak positive correlation between normal sperm morphology and conception rate (r = 0.11). Additionally ..... been approved by all of us. Authors' ...

Monoubiquitination Inhibits the Actin Bundling Activity of Fascin.

Science.gov (United States)

Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

2016-12-30

Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys 247 and Lys 250 , two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC 50 , delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Monoubiquitination Inhibits the Actin Bundling Activity of Fascin*

Science.gov (United States)

Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

2016-01-01

Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. PMID:27879315

Pulmonary exposure to carbonaceous nanomaterials and sperm quality.

Science.gov (United States)

Skovmand, Astrid; Jacobsen Lauvås, Anna; Christensen, Preben; Vogel, Ulla; Sørig Hougaard, Karin; Goericke-Pesch, Sandra

2018-01-31

Semen quality parameters are potentially affected by nanomaterials in several ways: Inhaled nanosized particles are potent inducers of pulmonary inflammation, leading to the release of inflammatory mediators. Small amounts of particles may translocate from the lungs into the lung capillaries, enter the systemic circulation and ultimately reach the testes. Both the inflammatory response and the particles may induce oxidative stress which can directly affect spermatogenesis. Furthermore, spermatogenesis may be indirectly affected by changes in the hormonal milieu as systemic inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model. Effects on sperm quality after pulmonary inflammation induced by carbonaceous nanomaterials were investigated by intratracheally instilling sexually mature male NMRI mice with four different carbonaceous nanomaterials dispersed in nanopure water: graphene oxide (18 μg/mouse/i.t.), Flammruss 101, Printex 90 and SRM1650b (0.1 mg/mouse/i.t. each) weekly for seven consecutive weeks. Pulmonary inflammation was determined by differential cell count in bronchoalveolar lavage fluid. Epididymal sperm concentration and motility were measured by computer-assisted sperm analysis. Epididymal sperm viability and morphological abnormalities were assessed manually using Hoechst 33,342/PI flourescent and Spermac staining, respectively. Epididymal sperm were assessed with regard to sperm DNA integrity (damage). Daily sperm production was measured in the testis, and testosterone levels were measured in blood plasma by ELISA. Neutrophil numbers in the bronchoalveolar fluid showed sustained inflammatory response in the nanoparticle-exposed groups one week after the last instillation. No significant changes in epididymal sperm parameters, daily sperm production or plasma testosterone levels

Some Reflections on Intracytoplasmic Morphologically Selected Sperm Injection

Directory of Open Access Journals (Sweden)

Thomas Ebner

2014-07-01

Full Text Available Although intracytoplasmic sperm injection (ICSI allows proper fertilization in most cases of male sub fertility, it is one of the most unphysiological techniques in assisted reproductive technologies (ART. Thus, over the last decade, researchers have tried to improve sperm observation with higher-resolution microscopy techniques such as the intracytoplasmic morphologically selected sperm injection (IMSI technique. In order to identify literatures for this review, the PubMed database was searched from 2000 onwards using the terms IMSI, motile sperm organelle morphology examination (MSOME and sperm vacuole. Approximately 10 years after the introduction of the MSOME and IMSI procedures, several questions related to the prevalence, origin, location, and clinical consequences of sperm vacuoles have not yet been clarified. It seems that IMSI as a routine application is not state of the art and the only confirmed indications for IMSI are recurrent implantation failure following ICSI and severe male factor.

Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

Science.gov (United States)

Rickman, S. L.; Iamello, C. J.

2016-01-01

Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

A dictionary learning approach for human sperm heads classification.

Science.gov (United States)

Shaker, Fariba; Monadjemi, S Amirhassan; Alirezaie, Javad; Naghsh-Nilchi, Ahmad Reza

2017-12-01

To diagnose infertility in men, semen analysis is conducted in which sperm morphology is one of the factors that are evaluated. Since manual assessment of sperm morphology is time-consuming and subjective, automatic classification methods are being developed. Automatic classification of sperm heads is a complicated task due to the intra-class differences and inter-class similarities of class objects. In this research, a Dictionary Learning (DL) technique is utilized to construct a dictionary of sperm head shapes. This dictionary is used to classify the sperm heads into four different classes. Square patches are extracted from the sperm head images. Columnized patches from each class of sperm are used to learn class-specific dictionaries. The patches from a test image are reconstructed using each class-specific dictionary and the overall reconstruction error for each class is used to select the best matching class. Average accuracy, precision, recall, and F-score are used to evaluate the classification method. The method is evaluated using two publicly available datasets of human sperm head shapes. The proposed DL based method achieved an average accuracy of 92.2% on the HuSHeM dataset, and an average recall of 62% on the SCIAN-MorphoSpermGS dataset. The results show a significant improvement compared to a previously published shape-feature-based method. We have achieved high-performance results. In addition, our proposed approach offers a more balanced classifier in which all four classes are recognized with high precision and recall. In this paper, we use a Dictionary Learning approach in classifying human sperm heads. It is shown that the Dictionary Learning method is far more effective in classifying human sperm heads than classifiers using shape-based features. Also, a dataset of human sperm head shapes is introduced to facilitate future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Single-phase convective heat transfer in rod bundles

International Nuclear Information System (INIS)

Holloway, Mary V.; Beasley, Donald E.; Conner, Michael E.

2008-01-01

The convective heat transfer for turbulent flow through rod bundles representative of nuclear fuel rods used in pressurized water reactors is examined. The rod bundles consist of a square array of parallel rods that are held on a constant pitch by support grids spaced axially along the rod bundle. Split-vane pair support grids, which create swirling flow in the rod bundle, as well as disc and standard support grids are investigated. Single-phase convective heat transfer coefficients are measured for flow downstream of support grids in a rod bundle. The rods are heated using direct resistance heating, and a bulk axial flow of air is used to cool the rods in the rod bundle. Air is used as the working fluid instead of water to reduce the power required to heat the rod bundle. Results indicate heat transfer enhancement for up to 10 hydraulic diameters downstream of the support grids. A general correlation is developed to predict the heat transfer development downstream of support grids. In addition, circumferential variations in heat transfer coefficients result in hot streaks that develop on the rods downstream of split-vane pair support grids

Single-phase convective heat transfer in rod bundles

Energy Technology Data Exchange (ETDEWEB)

Holloway, Mary V. [Mechanical Engineering Department, United States Naval Academy, 590 Holloway Rd., Annapolis, MD 21402 (United States)], E-mail: holloway@usna.edu; Beasley, Donald E. [Mechanical Engineering Department, Clemson University, Clemson, SC 29634 (United States); Conner, Michael E. [Westinghouse Nuclear Fuel, 5801 Bluff Road, Columbia, SC 29250 (United States)

2008-04-15

The convective heat transfer for turbulent flow through rod bundles representative of nuclear fuel rods used in pressurized water reactors is examined. The rod bundles consist of a square array of parallel rods that are held on a constant pitch by support grids spaced axially along the rod bundle. Split-vane pair support grids, which create swirling flow in the rod bundle, as well as disc and standard support grids are investigated. Single-phase convective heat transfer coefficients are measured for flow downstream of support grids in a rod bundle. The rods are heated using direct resistance heating, and a bulk axial flow of air is used to cool the rods in the rod bundle. Air is used as the working fluid instead of water to reduce the power required to heat the rod bundle. Results indicate heat transfer enhancement for up to 10 hydraulic diameters downstream of the support grids. A general correlation is developed to predict the heat transfer development downstream of support grids. In addition, circumferential variations in heat transfer coefficients result in hot streaks that develop on the rods downstream of split-vane pair support grids.

Methods of sperm vitality assessment.

Science.gov (United States)

Moskovtsev, Sergey I; Librach, Clifford L

2013-01-01

Sperm vitality is a reflection of the proportion of live, membrane-intact spermatozoa determined by either dye exclusion or osmoregulatory capacity under hypo-osmotic conditions. In this chapter we address the two most common methods of sperm vitality assessment: eosin-nigrosin staining and the hypo-osmotic swelling test, both utilized in clinical Andrology laboratories.

Characterization of Na+K+-ATPase in bovine sperm.

Science.gov (United States)

Hickey, Katie D; Buhr, Mary M

2012-04-15

Existing as a ubiquitous transmembrane protein, Na(+)K(+)-ATPase affects sperm fertility and capacitation through ion transport and a recently identified signaling function. Functional Na(+)K(+)-ATPase is a dimer of α and β subunits, each with isoforms (four and three, respectively). Since specific isoform pairings and locations may influence or indicate function, the objective of this study was to identify and localize subunits of Na(+)K(+)-ATPase in fresh bull sperm by immunoblotting and immunocytochemistry using antibodies against α1 and 3, and all β isoforms. Relative quantity of Na(+)K(+)-ATPase in head plasma membranes (HPM's) from sperm of different bulls was determined by densitometry of immunoblot bands, and compared to bovine kidney. Sperm and kidney specifically bound all antibodies at kDa equivalent to commercial controls, and to additional lower kDa bands in HPM. Immunofluorescence of intact sperm confirmed that all isoforms were present in the head region of sperm and that α3 was also uniformly distributed post-equatorially. Permeabilization exposing internal membranes typically resulted in an increase in fluorescence, indicating that some antibody binding sites were present on the inner surface of the HPM or the acrosomal membrane. Deglycosylation of β1 reduced the kDa of bands in sperm, rat brain and kidney, with the kDa of the deglycosylated bands differing among tissues. Two-dimensional blots of β1 revealed three distinct spots. Based on the unique quantity, location and structure Na(+)K(+)-ATPase subunits in sperm, we inferred that this protein has unique functions in sperm. Copyright © 2012 Elsevier Inc. All rights reserved.

Cost-effectiveness of a central venous catheter care bundle.

Directory of Open Access Journals (Sweden)

Kate A Halton

Full Text Available BACKGROUND: A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI. Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients. METHODS AND FINDINGS: A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters, or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds. CONCLUSIONS: A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision

In-pool damaged fuel bundle recovery

International Nuclear Information System (INIS)

Piascik, T.G.; Patenaude, R.S.

1988-01-01

While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package, and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power/Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved. In spite of several emergent problems which a task of this nature presents, this small, close knit utility/vendor team completed the work on schedule and within the exposure and cost budgets

Post Thawing Sperm Quality and Ca+2 Intensity Characters of Local Goat Sperm After Freezing by Simple Method Using Deep Freezing

Directory of Open Access Journals (Sweden)

Gatot Ciptadi

2018-02-01

Full Text Available The objective of this research was to determine the effect of the simple modified freezing method, 1°C/minute freezing rate with different diluter ration on a post-thawing quality of local goat sperm namely Peranakan Etawah (PE. This work is aimed to study the quality of post-thawing sperm and to characterize the calcium intensity profile of both fresh and post thawing goat sperm. The method used is the experimental design of a laboratory. Freezing semen was performed in 2 main temperatures of -45°C then -196°C respectively using Mr. Frosty (® System. Early Sperm characters of Ca+2 intensity was performed by Confocal Laser Scanning Microscope (CLSM through Fluo-3 staining and Ca++ intensity was analysis descriptively. The result showed that post-thawing qualities are considered as good as standard qualities, at least, more than 40% based on Indonesian National Standard (SNI, 2014. The different level diluents commercial of Andromeda used were influenced highly significant (P<0.01. The best diluents ration is 1:4 (v/v for final sperms stocked at -196°C. However freezing sperm conserved in -196°C is better than in -45°C. Meanwhile, the sperm characters of two condition showed the important variation of Ca+2 intensity, with the length of region measurement of 39.06±4.595 and 32.696±9.011 µm each.  It was concluded that the calcium intensity pattern was varied more and higher in fresh sperm than in freezing sperms. This simple modified method of a freezing system was considered as a feasible alternative method for goat semen in a reason for both for sperm post-thawing quality and practical purposes.

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

Sperm immobilization by dental focus microorganisms.

Science.gov (United States)

Linossier, A; Thumann, A; Bustos-Obregon, E

1982-01-01

Focal infections and their ability to produce alterations in different tissues have been in dispute for long time. The purpose of this work was to observe "in vitro" the effect of an Escherichia coli filtrate obtained from open pulpar necrosis on human sperm motility. It was observed that the E. coli filtrate produced a loss in sperm motility. The immobilizating factor was studied and characterized as a heat-stable, resistant to lyophilization and non-dializable substance, which could via blood stream reach the male reproductive system and affect sperm motility.

Comparison of ASSERT subchannel code with Marviken bundle data

International Nuclear Information System (INIS)

Tahir, A.; Carver, M.B.

1984-04-01

In this paper ASSERT predictions are compared with the Marviken 6-rod bundle and 36+1 rod bundle. The predictions are presented for two experiments in the 6-rod bundle and four experiments in the 36+1 rod bundle. For low inlet subcooling, the void predictions are in good agreement with the experimental data. For high inlet subcooling, however, the agreement is not as good. This is attributed to the fact that in the high inlet subcooling experiments, single phase turbulent mixing plays a more important role in determining flow conditions in the bundle

Sperm depletion as a consequence of increased sperm competition risk in the European bitterling, Rhodeus amarus

Czech Academy of Sciences Publication Activity Database

Smith, C.; Pateman-Jones, C.; Zieba, G.; Przybylski, M.; Reichard, Martin

2009-01-01

Roč. 77, č. 5 (2009), s. 1227-1233 ISSN 0003-3472 Institutional research plan: CEZ:AV0Z60930519 Keywords : alternative mating tactics * European bitterling * mating system * sexual conflict * sexual selection * sneaking * sperm competition * sperm economy Subject RIV: EG - Zoology Impact factor: 2.890, year: 2009

One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

Directory of Open Access Journals (Sweden)

Ho Jong Ra

2017-01-01

Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

Aggregation of human sperm at higher temperature is due to hyperactivation.

Science.gov (United States)

Keppler, E L; Chan, P J; Patton, W C; King, A

1999-01-01

Chemotaxis of sperm cells to chemicals and hormones, such as progesterone, helps us to understand the concept of sperm transport. Here, the hypothesis was that heat increased sperm hyperactive motility, which caused the sperm to aggregate at the higher temperature. The objectives were (1) to determine the concentration of sperm at both halves of an artificial female reproductive tract made from a hermetically sealed cryopreservation straw filled with culture medium and placed with each end at different temperatures, and (2) to analyze the motility or kinematic parameters and hyperactivation of sperm found at the different temperatures. Cryopreserved-thawed human donor sperm (N = 6) were pooled and processed through 2-layer colloid solution. Analyses of the motile sperm were carried out and the washed sperm were homogeneously mixed and pipetted into several 0.5-mL French cryopreservation straws and heat-sealed. The control substance, consisting of acid-treated sperm, was also placed in several straws. The plastic straws of sperm were placed half at 23 degrees C and half was at either 37 or 40 degrees C. After 4 h, sperm at different sections of the straws were analyzed using the Hamilton Thorn motility analyzer (HTM-C). After 4 h of incubation, the concentration of sperm was doubled at the 40 degrees C heated half of the straw when compared with the other half of the straw at 23 degrees C. There were no differences in sperm concentration in the straw kept half at 37 degrees C and half at 23 degrees C. There were significantly higher percent motility, mean average path velocity, straight line velocity, lateral head displacement, and percent hyperactivation in sperm at the 40 degrees C temperature. The aggregation of sperm at the higher temperature of 40 degrees C may be due to enhanced motility, increased sperm velocities, and a 10-fold increase in hyperactivation at that temperature. The 37 degrees C temperature was not sufficient to attract sperm. Sperm cells

Bundling of elastic filaments induced by hydrodynamic interactions

Science.gov (United States)

Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric

2017-12-01

Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long

PDS4 Bundle Creation Governance Using BPMN

Science.gov (United States)

Radulescu, C.; Levoe, S. R.; Algermissen, S. S.; Rye, E. D.; Hardman, S. H.

2015-06-01

The AMMOS-PDS Pipeline Service (APPS) provides a Bundle Builder tool, which governs the process of creating, and ultimately generates, PDS4 bundles incrementally, as science products are being generated.

Enthalpy and void distributions in subchannels of PHWR fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Park, J W; Choi, H; Rhee, B W [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1999-12-31

Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

Enthalpy and void distributions in subchannels of PHWR fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Park, J. W.; Choi, H.; Rhee, B. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

Accountings of Selecting Sperm on the (ethical) border

DEFF Research Database (Denmark)

Willum Adrian, Stine

During the past years, Denmark has become a destination for fertility travellers, in need for donated sperm. Today, treatment is possible no matter of marital status or sexuality. Furthermore, users of sperm donation can choose between anonymous and non-anonymous sperm, with either basic...... will analyze how women and their partners crossing the Danish border accounts for their donor choice, and their practices of choosing. I will be exploring the question: How are women and their partners accounting for choosing a sperm donor, crossing the (ethical) border to Denmark? The use of the term...

CANFLEX fuel bundle junction pressure drop

International Nuclear Information System (INIS)

Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

1996-11-01

This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs

CANFLEX fuel bundle junction pressure drop

Energy Technology Data Exchange (ETDEWEB)

Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

1996-11-01

This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs.

Cytometry of mammalian sperm

Energy Technology Data Exchange (ETDEWEB)

Gledhill, B.L.

1983-10-11

Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. The accessibility of male cells makes them well suited for analytical cytology. We might automate the process of determining sperm morphology but should not do so solely for increased speed. Rather, richer tangible benefits will derive from cytometric evaluation through increased sensitivity, reduced subjectivity, standardization between investigators and laboratories, enhanced archival systems, and the benefits of easily exchanged standardized data. Inroads on the standardization of assays for motility and functional integrity are being made. Flow cytometric analysis of total DNA content of individual sperm is an insensitive means to detect exposure to reproductive toxins because of the small size and low frequency of the DNA content errors. Flow cytometry can be applied to determine the proportions of X- and Y-sperm in semen samples.

Cytometry of mammalian sperm

International Nuclear Information System (INIS)

Gledhill, B.L.

1983-01-01

Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. The accessibility of male cells makes them well suited for analytical cytology. We might automate the process of determining sperm morphology but should not do so solely for increased speed. Rather, richer tangible benefits will derive from cytometric evaluation through increased sensitivity, reduced subjectivity, standardization between investigators and laboratories, enhanced archival systems, and the benefits of easily exchanged standardized data. Inroads on the standardization of assays for motility and functional integrity are being made. Flow cytometric analysis of total DNA content of individual sperm is an insensitive means to detect exposure to reproductive toxins because of the small size and low frequency of the DNA content errors. Flow cytometry can be applied to determine the proportions of X- and Y-sperm in semen samples

Thyroxin Is Useful to Improve Sperm Motility

Directory of Open Access Journals (Sweden)

Mendeluk Gabriela Ruth

2016-07-01

Full Text Available Background The aim of this study was to evaluate the non-genomic action of thyroxin on sperm kinetic and its probable use to improve sperm recovery after applying an en- richment method like “swim-up” in comparison with the available one, pentoxifylline. Materials and Methods This is an experimental study. A total of 50 patients were re- cruited, followed by infertility consultation. Conventional sperm assays were performed according to World Health Organization criteria-2010 (WHO-2010. A Computer Aided Semen Analysis System was employed to assess kinetic parameters and concentrations. Number of the motile sperm recovered after preparation technique was calculated. Results Addition of T4 (0.002 µg/ml to semen samples increased hypermotility at 20 minutes (control: 14.18 ± 5.1% vs. 17.66 ± 8.88%, P<0.03, data expressed as mean ± SD and remained unchanged after 40 minutes. Significant differences were found in the motile sperm recovered after swim-up (control: 8.93×106 ± 9.52× 06vs. 17.20×106 ± 21.16×106, P<0.03, achieving all of the tested samples a desirable threshold value for artificial insemination outcome, while adding pentoxifylline increased the number of recovered sperm after swim-up in 60% of the studied cases. No synergism between two treatments could be determined. Conclusion We propose a new physiological tool to artificially improve insemination. The discussion opens windows to investigate unknown pathways involved in sperm ca- pacitation and gives innovative arguments to better understand infertility mechanisms.

Patterns of sperm damage in Chernobyl passerine birds suggest a trade-off between sperm length and integrity

Czech Academy of Sciences Publication Activity Database

Hermosell, I. G.; Laskemoen, T.; Rowe, M.; Moller, A. P.; Mousseau, T. A.; Albrecht, Tomáš; Lifjeld, J. T.

2013-01-01

Roč. 9, č. 5 (2013), s. 20130530 ISSN 1744-9561 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : acrosome * radiation * sperm evolution * sperm size Subject RIV: EG - Zoology Impact factor: 3.425, year: 2013

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.

2012-09-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.; Kirkman-Brown, J.C.; Connolly, T.J.; Gaffney, E.A.

2012-01-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Vitrification of neat semen alters sperm parameters and DNA integrity.

Science.gov (United States)

Khalili, Mohammad Ali; Adib, Maryam; Halvaei, Iman; Nabi, Ali

2014-05-06

Our aim was to evaluate the effect of neat semen vitrification on human sperm vital parameters and DNA integrity in men with normal and abnormal sperm parameters. Semen samples were 17 normozoospermic samples and 17 specimens with abnormal sperm parameters. Semen analysis was performed according to World Health Organization (WHO) criteria. Then, the smear was provided from each sample and fixed for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Vitrification of neat semen was done by plunging cryoloops directly into liquid nitrogen and preserved for 7 days. The samples were warmed and re-evaluated for sperm parameters as well as DNA integrity. Besides, the correlation between sperm parameters and DNA fragmentation was assessed pre- and post vitrification. Cryopreserved spermatozoa showed significant decrease in sperm motility, viability and normal morphology after thawing in both normal and abnormal semen. Also, the rate of sperm DNA fragmentation was significantly higher after vitrification compared to fresh samples in normal (24.76 ± 5.03 and 16.41 ± 4.53, P = .002) and abnormal (34.29 ± 10.02 and 23.5 ± 8.31, P < .0001), respectively. There was negative correlation between sperm motility and sperm DNA integrity in both groups after vitrification. Vitrification of neat ejaculates has negative impact on sperm parameters as well as DNA integrity, particularly among abnormal semen subjects. It is, therefore, recommend to process semen samples and vitrify the sperm pellets.

Axicon-based annular laser trap for studies on sperm activity

Science.gov (United States)

Shao, Bing; Vinson, Jaclyn M.; Botvinick, Elliot L.; Esener, Sadik C.; Berns, Michael W.

2005-08-01

As a powerful and noninvasive tool, laser trapping has been widely applied for the confinement and physiological study of biological cells and organelles. Researchers have used the single spot laser trap to hold individual sperm and quantitatively evaluated the motile force generated by a sperm. Early studies revealed the relationship between sperm motility and swimming behavior and helped the investigations in medical aspects of sperm activity. As sperm chemotaxis draws more and more interest in fertilization research, the studies on sperm-egg communication may help to explain male or female infertility and provide exciting new approaches to contraception. However, single spot laser trapping can only be used to investigate an individual target, which has limits in efficiency and throughput. To study the chemotactic response of sperm to eggs and to characterize sperm motility, an annular laser trap with a diameter of several hundred microns is designed, simulated with ray tracing tool, and implemented. An axicon transforms the wavefront such that the laser beam is incident on the microscope objective from all directions while filling the back aperture completely for high efficiency trapping. A trapping experiment with microspheres is carried out to evaluate the system performance. The power requirement for annular sperm trapping is determined experimentally and compared with theoretical calculations. With a chemo-attractant located in the center and sperm approaching from all directions, the annular laser trapping could serve as a speed bump for sperm so that motility characterization and fertility sorting can be performed efficiently.

Restriction of Preferences to the Set of Consumption Bundles, In a Model with Production and Consumption Bundles

NARCIS (Netherlands)

Schalk, S.

1999-01-01

In contrast to the neo-classical theory of Arrow and Debreu, a model of a private ownership economy is presented, in which production and consumption bundles are treated separately. Each of the two types of bundles is assumed to establish a con- vex cone. Production technologies can convert

Aspermy, Sperm Quality and Radiation in Chernobyl Birds

Science.gov (United States)

Møller, Anders Pape; Bonisoli-Alquati, Andrea; Mousseau, Timothy A.; Rudolfsen, Geir

2014-01-01

Background Following the Chernobyl nuclear power plant accident, large amounts of radionuclides were emitted and spread in the environment. Animals living in such contaminated areas are predicted to suffer fitness costs including reductions in the quality and quantity of gametes. Methodology/Principal Findings We studied whether aspermy and sperm quality were affected by radioactive contamination by examining ejaculates from wild caught birds breeding in areas varying in background radiation level by more than three orders of magnitude around Chernobyl, Ukraine. The frequency of males with aspermy increased logarithmically with radiation level. While 18.4% of males from contaminated areas had no sperm that was only the case for 3.0% of males from uncontaminated control areas. Furthermore, there were negative relationships between sperm quality as reflected by reduced sperm velocity and motility, respectively, and radiation. Conclusions/Significance Our results suggest that radioactive contamination around Chernobyl affects sperm production and quality. We are the first to report an interspecific difference in sperm quality in relation to radioactive contamination. PMID:24963711

Effect of ionizing radiations on sperm of mice

International Nuclear Information System (INIS)

Khattab, F.I.; Hassan, N.H.A.; Eldawt, H.A.; Roushdy, H.M.

1995-01-01

Effects of both gamma rays and reactor beams of mixed neutrons and gamma rays on sperms were investigated. Caudal sperms of adult male mice were examined 3 and 6 weeks post-exposure to 0.5 , 1.5, 3.0 and 6.0 Gy gamma rays and 1, 2, 3, and 4 weeks in animals exposed to 42.5 and 58.5 R of mixed neutrons and gamma-rays. Sperms were seriously affected due to exposure to both types of irradiation. There were dose dependent changes in the mean frequency of abnormal sperms. The peak values were at dose level of 3.0 Gy recording 26.43% and 29.82% in both groups sacrificed 3 and 6 weeks respectively compared with 1.57% for the control group. The increase in the abnormal sperms in the groups of the animals exposed to the reactor beam was always related to the time interval between treatment and observation, the longer the time the more sperms with abnormal head were encountered. 14 figs., 2 tabs

Sperm variables as predictors of fertility in Black Castellana roosters; use in the selection of sperm donors for genome resource banking purposes

Energy Technology Data Exchange (ETDEWEB)

Santiago Moreno, J.; Lopez Sebastian, A.; Castano, C.; Coloma, M. A.; Gomez Brunet, A.; Toledano Diaz, A.; Prieto, M. T.; Campo, J. L.

2009-07-01

Semen was collected from 10 Black Castellana roosters and the classic sperm variables (ejaculate volume, sperm concentration and sperm motility) examined. In addition, the hypo-osmotic swelling test was used to investigate sperm cell membrane integrity, and acidic aniline blue staining used to screen for morphological abnormalities (including acrosome integrity) and to examine the condensation status of the chromatin. The latter was also examined by Gram staining. Large and small semen volumes were associated high and low sperm concentrations respectively (R2=0.04, P<0.05). The percentage of motile spermatozoa correlated strongly with the percentage of sperm cells showing an intact acrosome (R2=0.13, P<0.001) and with the percentage of morphologically normal spermatozoa (R2=0.04, P<0.05). The percentage of Gram positive spermatozoa was positively correlated with semen appearance (R2=0.12, P<0.05), sperm cell concentration (R2=0.13, P<0.05), and with the sperm motility variables studied (R2=0.14, P<0.05 for percentage mobility, and R2=0.12, P<0.05 for quality of movement). Only three of the 10 roosters, all with fertilisation potentials of 80-90%, were considered potential sperm donors for genome resource banking purposes. The remaining birds were all of low fertility (. 50%); in fact, some produced semen volumes too small to perform fertility tests. Semen volume and membrane integrity were found to be the best variables for predicting the fertilisation potential of rooster ejaculates. (Author) 37 refs.

FEMALE CONTROL OF SPERM TRANSFER AND INTRASPECIFIC VARIATION IN SPERM PRECEDENCE: ANTECEDENTS TO THE EVOLUTION OF A COURTSHIP FOOD GIFT.

Science.gov (United States)

Sakaluk, Scott K; Eggert, Anne-Katrin

1996-04-01

Manipulation of ejaculates is believed to be an important avenue of female choice throughout the animal kingdom, but evidence of its importance to sexual selection remains scarce. In crickets, such manipulation is manifest in the premature removal of the externally attached spermatophore, which may afford females an important means of postcopulatory mate choice. We tested the hypothesis that premature spermatophore removal contributes significantly to intraspecific variation in sperm precedence by (1) experimentally manipulating spermatophore attachment durations of competing male Gryllodes sigillatus and (2) employing protein electrophoresis to determine the paternity of doubly mated females. The relative spermatophore attachment durations of competing males had a significant influence on male paternity, but the pattern of sperm precedence deviated significantly from the predictions of an ideal lottery. Instead, paternity data and morphological evidence accorded best with a model of partial sperm displacement derived here. Our model is similar to a displacement model of Parker et al. in that sperm of the second male mixes instantaneously with that of the first throughout the displacement process, but the novel feature of our model is that the number of sperm displaced is only a fraction of the number of sperm transferred by the second male. Regardless of the underlying mechanism, female G. sigillatus can clearly alter the paternity of their offspring through their spermatophore-removal behavior, and employ such cryptic choice in favoring larger males and those providing larger courtship food gifts. We discuss how female control of sperm transfer and intraspecific variation in sperm precedence may be important precursors to the evolution of gift giving in insects. © 1996 The Society for the Study of Evolution.

GPU Parallel Bundle Block Adjustment

Directory of Open Access Journals (Sweden)

ZHENG Maoteng

2017-09-01

Full Text Available To deal with massive data in photogrammetry, we introduce the GPU parallel computing technology. The preconditioned conjugate gradient and inexact Newton method are also applied to decrease the iteration times while solving the normal equation. A brand new workflow of bundle adjustment is developed to utilize GPU parallel computing technology. Our method can avoid the storage and inversion of the big normal matrix, and compute the normal matrix in real time. The proposed method can not only largely decrease the memory requirement of normal matrix, but also largely improve the efficiency of bundle adjustment. It also achieves the same accuracy as the conventional method. Preliminary experiment results show that the bundle adjustment of a dataset with about 4500 images and 9 million image points can be done in only 1.5 minutes while achieving sub-pixel accuracy.

Mouse Y-Encoded Transcription Factor Zfy2 Is Essential for Sperm Head Remodelling and Sperm Tail Development

NARCIS (Netherlands)

Vernet, Nadege; Mahadevaiah, Shantha K.; Decarpentrie, Fanny; Longepied, Guy; de Rooij, Dirk G.; Burgoyne, Paul S.; Mitchell, Michael J.

2016-01-01

A previous study indicated that genetic information encoded on the mouse Y chromosome short arm (Yp) is required for efficient completion of the second meiotic division (that generates haploid round spermatids), restructuring of the sperm head, and development of the sperm tail. Using mouse models

Impaired Sperm Maturation in Rnase9 Knockout Mice1

Science.gov (United States)

Westmuckett, Andrew D.; Nguyen, Edward B.; Herlea-Pana, Oana M.; Alvau, Antonio; Salicioni, Ana M.; Moore, Kevin L.

2014-01-01

ABSTRACT Ribonuclease, RNase A family, 9 (RNASE9) is a ribonuclease A superfamily member that is expressed only in the epididymis. It is a small, secreted polypeptide, it lacks ribonuclease activity, and its function(s) is unknown. However, epididymis-specific expression suggests a role in sperm maturation. We generated Rnase9−/− mice to study RNASE9 function in vivo. We confirm that RNASE9 expression is restricted to the epididymis. Within the epididymis, RNASE9 is first detected in midcaput, persists through the distal caput and corpus, and wanes in the cauda. Rnase9−/− mice are born at the expected Mendelian ratio, have normal postnatal growth and development, and have no outwardly apparent phenotype. Spermatogenesis is normal, and Rnase9-null sperm are morphologically normal. Rnase9−/− males have normal fertility in unrestricted mating trials, and fertilization rates in in vitro fertilization assays are indistinguishable from wild-type mice. Visual observations coupled with analyses of sperm velocities shortly after swim out from the corpus shows that motility of Rnase9-null sperm is significantly impaired. However, no differences between wild-type and Rnase9-null sperm are detected by computer-assisted sperm analysis 10–90 min after sperm isolation from the corpus or cauda. Assessment of capacitation-dependent signaling pathways in Rnase9-null sperm showed that, while levels of tyrosine phosphorylation of sperm proteins were normal, there was decreased phosphorylation of protein kinase A substrates upon capacitation compared to wild-type mice. In conclusion, RNASE9 is dispensable for fertility, but the absence of RNASE9 during epididymal transit results in impaired sperm maturation. PMID:24719258

Mammalian Sperm Motility: Observation and Theory

KAUST Repository

Gaffney, E.A.

2011-01-21

Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics. © 2011 by Annual Reviews. All rights reserved.

Sperm quality in New Zealand: Is the downward trend continuing?

Science.gov (United States)

Birdsall, Mary A; Peek, John; Valiapan, Sumithra

2015-10-16

To investigate whether the decline in sperm concentration in New Zealand sperm donors observed from 1987 to 2007 continued in the period 2008-2014. A retrospective study from 2008 to 2014. The first semen sample of 285 men presenting as sperm donors in Auckland and Wellington was analysed for sperm concentration, seminal fluid volume and the percentage of motile sperm. These results were compared to results from 1987 to 2007 from the same clinics. The decline in semen volume and sperm concentration observed between 1987 and 2007 did not continue in 2008-2014. Sperm concentration decreased from 1987 until some time between 1997 and 2001, and has remained stable at an average of 62x106/ml between 2001 and 2014. Sperm motility declined significantly (8%) in the period 2008-2014, but there was no significant change over the total period studied, between 1987 and 2014. After a decline between 1987 and sometime during 1997-2001, the sperm concentration in men presenting as donors remained unchanged between 2002 and 2014, suggesting semen quality has not changed in New Zealand men over the last decade.

Pronounced within-individual plasticity in sperm morphometry across social environments.

Science.gov (United States)

Immler, Simone; Pryke, Sarah R; Birkhead, Tim R; Griffith, Simon C

2010-06-01

Sperm morphometry (i.e., size and shape) and function are important determinants of male reproductive success and are thought to be under stabilizing selection. However, recent studies suggest that sperm morphometry can be a phenotypically plastic trait, which can be adjusted to varying conditions. We tested whether different behavioral strategies in aggression between aggressive red and nonaggressive black males of the color polymorphic Gouldian finch (Erythrura gouldiae) can influence sperm morphometry. We show pronounced within-individual phenotypic plasticity in sperm morphometry of male Gouldian finches in three different social environments. Both red and black males placed in intermediate to high competitive environments (high frequency of red males) increased the relative length of their sperm midpiece. By contrast, red males placed in low to intermediate competitive environments (higher frequency of black males) increased the length of the sperm flagellum. Significant changes in stress and sex steroid hormone levels (in response to the competitive environment) appear to influence sperm traits in red but not in black males, suggesting that changes in hormonal levels are not solely responsible for the observed changes in sperm morphometry. These findings imply that males can adjust sperm morphometry across social environments.

Nuclear fuel bundle disassembly and assembly tool

International Nuclear Information System (INIS)

Yates, J.; Long, J.W.

1975-01-01

A nuclear power reactor fuel bundle is described which has a plurality of tubular fuel rods disposed in parallel array between two transverse tie plates. It is secured against disassembly by one or more locking forks which engage slots in tie rods which position the transverse plates. Springs mounted on the fuel and tie rods are compressed when the bundle is assembled thereby maintaining a continual pressure against the locking forks. Force applied in opposition to the springs permits withdrawal of the locking forks so that one tie plate may be removed, giving access to the fuel rods. An assembly and disassembly tool facilitates removal of the locking forks when the bundle is to be disassembled and the placing of the forks during assembly of the bundle. (U.S.)

Effect of Vitrification on Sperm Parameters and Apoptosis in Fertile Men

OpenAIRE

M Adib; M Ramezani; MA Khalili

2011-01-01

Introduction & Objective: Today, cryopreservation of the human sperm is a common technique for treating infertility. It has been indicated that cryopreservation by different methods decrease the sperm motility and viability in fertile men, but still effect of freezing of the sperm by vitrification method have not been evaluated on sperm parameters and apoptosis. The aim of this study was to evaluate the effect of vitrification of sperm of fertile men on different sperm parameters (motility, m...

Sperm competition risk drives rapid ejaculate adjustments mediated by seminal fluid.

Science.gov (United States)

Bartlett, Michael J; Steeves, Tammy E; Gemmell, Neil J; Rosengrave, Patrice C

2017-10-31

In many species, males can make rapid adjustments to ejaculate performance in response to sperm competition risk; however, the mechanisms behind these changes are not understood. Here, we manipulate male social status in an externally fertilising fish, chinook salmon ( Oncorhynchus tshawytscha ), and find that in less than 48 hr, males can upregulate sperm velocity when faced with an increased risk of sperm competition. Using a series of in vitro sperm manipulation and competition experiments, we show that rapid changes in sperm velocity are mediated by seminal fluid and the effect of seminal fluid on sperm velocity directly impacts paternity share and therefore reproductive success. These combined findings, completely consistent with sperm competition theory, provide unequivocal evidence that sperm competition risk drives plastic adjustment of ejaculate quality, that seminal fluid harbours the mechanism for the rapid adjustment of sperm velocity and that fitness benefits accrue to males from such adjustment.

Flow in rod bundles

International Nuclear Information System (INIS)

Hazi, G.; Mayer, G.

2005-01-01

For power upgrading VVER-440 reactors we need to know exactly how the temperature measured by the thermocouples is related to the average outlet temperature of the fuel assemblies. Accordingly, detailed knowledge on mixing process in the rod bundles and in the fuel assembly head have great importance. Here we study the hydrodynamics of rod bundles based on the results of direct numerical and large eddy simulation of flows in subchannels. It is shown that secondary flow and flow pulsation phenomena can be observed using both methodologies. Some consequences of these observations are briefly discussed. (author)

Sperm quality assessment via separation and sedimentation in a microfluidic device.

Science.gov (United States)

Chen, Chang-Yu; Chiang, Tsun-Chao; Lin, Cheng-Ming; Lin, Shu-Sheng; Jong, De-Shien; Tsai, Vincent F-S; Hsieh, Ju-Ton; Wo, Andrew M

2013-09-07

A major reason for infertility is due to male factors, including the quality of spermatozoa, which is a primary factor and often difficult to assess, particularly the total sperm concentration and its motile percentage. This work presents a simple microfluidic device to assess sperm quality by quantifying both total and motile sperm counts. The key design feature of the microfluidic device is two channels separated by a permeative phase-guide structure, where one channel is filled with raw semen and the other with pure buffer. The semen sample was allowed to reach equilibrium in both chambers, whereas non-motile sperms remained in the original channel, and roughly half of the motile sperms would swim across the phase-guide barrier into the buffer channel. Sperms in each channel agglomerated into pellets after centrifugation, with the corresponding area representing total and motile sperm concentrations. Total sperm concentration up to 10(8) sperms per ml and motile percentage in the range of 10-70% were tested, encompassing the cutoff value of 40% stated by World Health Organization standards. Results from patient samples show compact and robust pellets after centrifugation. Comparison of total sperm concentration between the microfluidic device and the Makler chamber reveal they agree within 5% and show strong correlation, with a coefficient of determination of R(2) = 0.97. Motile sperm count between the microfluidic device and the Makler chamber agrees within 5%, with a coefficient of determination of R(2) = 0.84. Comparison of results from the Makler Chamber, sperm quality analyzer, and the microfluidic device revealed that results from the microfluidic device agree well with the Makler chamber. The sperm microfluidic chip analyzes both total and motile sperm concentrations in one spin, is accurate and easy to use, and should enable sperm quality analysis with ease.

Bundling harvester; Nippukorjausharvesteri

Energy Technology Data Exchange (ETDEWEB)

Koponen, K [Eko-Log Oy, Kuopio (Finland)

1997-12-31

The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

Bundling harvester; Nippukorjausharvesteri

Energy Technology Data Exchange (ETDEWEB)

Koponen, K. [Eko-Log Oy, Kuopio (Finland)

1996-12-31

The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

Sperm-egg penetration assay assessment of the contraceptive effects of glycerol and egg yolk in rooster sperm diluents.

Science.gov (United States)

Abouelezz, F M K; Castaño, C; Toledano-Díaz, A; Esteso, M C; López-Sebastián, A; Campo, J L; Santiago-Moreno, J

2015-06-01

Glycerol (GLY) and egg yolk (EY) are good cryoprotectants of avian and mammalian sperm, but in birds, they strongly inhibit the eventual fertilization of ova. Using the sperm penetration (SP-holes) assay and fertility trials, the present study investigates (1) the possible mechanism by which this contraceptive effect occurs in chickens and (2) the maximum concentrations of GLY and EY tolerated by fresh rooster sperm. Seventy Black-Barred Andaluza hens (five per treatment) were inseminated four times (twice per week) with 0.1 mL of fresh semen from roosters of the same breed diluted 1:1 (v:v) with Lake and Ravie medium containing different concentrations of GLY or EY. No adverse effects on acrosome integrity, sperm motility, or viability were seen with any concentration of GLY or EY. The number of SP-holes on perivitelline layer samples taken from above the germinal disc became progressively lower at GLY concentrations of 1.5% or greater (P > 0.05). No holes caused by sperms were seen in unfertilized eggs. The corresponding fertility results showed similar reductions when the GLY concentration was 1.5% or greater. No changes in the number of SP-holes were seen with increasing EY concentrations (0%-7.5%), nor were any differences in fertility observed, except for a reduction when 15% EY was used. The results therefore reveal that GLY affects the transit of sperms through the oviduct in their attempt to reach the infundibulum area, limiting their access to the ovum perivitelline layer. Egg yolk had no such effect, nor did it influence acrosome reaction capacity; its mechanism of contraceptive action therefore remains unknown. The maximum GLY and EY concentrations tolerated by the rooster sperm were 0.75% and 7.5%, respectively. Copyright © 2015 Elsevier Inc. All rights reserved.

Sperm banking is of key importance in patients with prostate cancer.

Science.gov (United States)

Salonia, Andrea; Capogrosso, Paolo; Castiglione, Fabio; Russo, Andrea; Gallina, Andrea; Ferrari, Matteo; Clementi, Maria Chiara; Castagna, Giulia; Briganti, Alberto; Cantiello, Francesco; Damiano, Rocco; Montorsi, Francesco

2013-08-01

To assess the need for sperm banking among patients with prostate cancer (PCa) who are candidates for radical prostatectomy (RP). Cross-sectional study. Urologic department. Cohort of 510 Caucasian-European candidates for RP. A 10-item self-administered questionnaire to assess opinions on sperm banking before RP, to which descriptive statistics and logistic regression models were applied. PCa patients' wishes for preoperative sperm banking. Data collection was completed for 495 patients (97.1%). Ninety-nine (20%) expressed a wish for preoperative sperm banking. Men who wanted to bank sperm were younger (mean 62.2 vs. 65.1 years), were more frequently childless (21.2% vs. 8.8%), and more frequently had a more intense desire for fatherhood (64.7% vs. 9.3%) than the patients not interested in banking sperm. Willingness to bank sperm was not affected by the patient's educational or relationship status. Moreover, the interest for sperm banking was maintained regardless of cost issues. Overall, 84% of the patients considered it necessary to have a dedicated service of preoperative sperm cryopreservation. One out of five PCa patients would bank sperm before RP. Most patients considered it necessary to establish a dedicated service for preoperative sperm cryopreservation, regardless of their own motivation to bank sperm. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Postmortem sperm procurement: a legal perspective.

Science.gov (United States)

Kahan, S E; Seftel, A D; Resnick, M I

1999-06-01

Postmortem sperm procurement with subsequent artificial insemination has become a technically feasible method for posthumous conception. A variety of legal questions exist involving the rights and relationships of the deceased, his family and his issue. We addressed these questions and designed a workable protocol for postmortem sperm procurement. MEDLINE, WESTLAW and LEXIS medical literature, and case law searches were conducted. United States and international case law, United States (federal and state) statutes, Uniform Law Commissions Acts, and law review commentaries and articles were reviewed. While postmortem sperm procurement is being requested throughout the United States, no standard protocol or procedural guidelines have been established by federal or state statute. Furthermore, the courts have not yet addressed this specific scenario in reported case law. Statutes and case law do address related factual scenarios and issues, including property rights in human bodies, rules governing transplantation of human organs/body parts, rights of parties in in vivo sperm bank donations and responsibilities of parents to the conceptus of artificial insemination. A workable protocol can be established by analyzing case law and statutes addressing factually similar scenarios. Urologists must focus on the express intent of the decedent and limit any postmortem sperm retrieval to the specific requests made by the decedent. Decedent requests should be documented in writing. The decedent must be competent and of majority age. In the absence of decedent expressed affirmative directive calling for sperm retrieval, no other relative or guardian may authorize this retrieval. Issues regarding the legitimacy and inheritance rights of the conceptus will most consistently be addressed when explicitly provided for in the will of the decedent.

Role of WNT signaling in epididymal sperm maturation.

Science.gov (United States)

Cheng, Jin-Mei; Tang, Ji-Xin; Li, Jian; Wang, Yu-Qian; Wang, Xiu-Xia; Zhang, Yan; Chen, Su-Ren; Liu, Yi-Xun

2018-02-01

Spermatozoa maturation, a process required for spermatozoa to acquire progressive motility and the ability to fertilize ova, primarily occurs in the caput and corpus of the epididymis. Despite considerable efforts, the factor(s) promoting epididymal sperm maturation remains unclear. Recently, WNT signaling has been implicated in epididymal sperm maturation. To further investigate WNT signaling function in epididymal sperm maturation, we generated Wntless conditional knockout mice (Wls cKO), Wls flox/flox ; Lcn5-Cre. In these mice, WNTLESS (WLS), a conserved membrane protein required for all WNT protein secretion, was specifically disrupted in the principal cells of the caput epididymidis. Immunoblot analysis showed that WLS was significantly reduced in the caput epididymidis of Wls cKO mice. In the caput epididymidis of Wls cKO mice, WNT 10A and WNT 2b, which are typically secreted by the principal cells of the caput epididymis, were not secreted. Interestingly, sperm motility analysis showed that the WLS deficiency in the caput epididymidis had no effect on sperm motility. Moreover, fertility tests showed that Wls cKO male mice had normal fertility. These results indicate that the disruption of WLS in principal cells of the caput epididymidis inhibits WNT protein secretion but has no effect on sperm motility and male fertility, suggesting that WNT signaling in the caput epididymidis may be dispensable for epididymal sperm maturation in mice.

A Tannakian approach to dimensional reduction of principal bundles

Science.gov (United States)

Álvarez-Cónsul, Luis; Biswas, Indranil; García-Prada, Oscar

2017-08-01

Let P be a parabolic subgroup of a connected simply connected complex semisimple Lie group G. Given a compact Kähler manifold X, the dimensional reduction of G-equivariant holomorphic vector bundles over X × G / P was carried out in Álvarez-Cónsul and García-Prada (2003). This raises the question of dimensional reduction of holomorphic principal bundles over X × G / P. The method of Álvarez-Cónsul and García-Prada (2003) is special to vector bundles; it does not generalize to principal bundles. In this paper, we adapt to equivariant principal bundles the Tannakian approach of Nori, to describe the dimensional reduction of G-equivariant principal bundles over X × G / P, and to establish a Hitchin-Kobayashi type correspondence. In order to be able to apply the Tannakian theory, we need to assume that X is a complex projective manifold.

The chromosomal risk in sperm from heterozygous Robertsonian translocation carriers is related to the sperm count and the translocation type.

Science.gov (United States)

Ferfouri, Fatma; Selva, Jacqueline; Boitrelle, Florence; Gomes, Denise Molina; Torre, Antoine; Albert, Martine; Bailly, Marc; Clement, Patrice; Vialard, François

2011-12-01

To study the chromosomal risk in sperm from Robertsonian translocation (RobT) carriers as a function of the sperm count and translocation type. Prospective study. Departments of reproductive biology, cytogenetics, gynecology, and obstetrics. A total of 29 RobT patients (8 normozoospermic and 21 oligozoospermic) and 20 46,XY patients (10 normozoospermic and 10 oligozoospermic). Sperm fluorescence in situ hybridization with probes for translocation malsegregation and chromosome 13, 18, 21, X, and Y probes for studying the interchromosomal effect (ICE). Translocation malsegregation and ICE aneuploidy rates. In RobT carriers, the sperm translocation malsegregation rate was significantly lower in normozoospermic patients (9.7%) than in oligozoospermic patients (18.0%). Considering only oligozoospermic patients, sperm malsegregation rates were significantly lower for rob(14;21) than for rob(13;14) (11.4% vs. 18.9%). In turn, the rates were significantly lower for rob(13;14) than for rare RobTs (18.9% vs. 25.3%). In sperm from normozoospermic RobT, an ICE was suggested by higher chromosome 13 and 21 aneuploidy rates than in control sperm. Conversely, chromosome 13 and 21 sperm aneuploidy rates were lower in oligozoospermic RobT patients than in oligozoospermic 46,XY patients, but higher than in control subjects. Both translocation type and sperm count influence the RobT malsegregation risk. Of the chromosomes analyzed (13, 18, 21, X, and Y), only chromosomes 13 and 21 were found to be associated with an ICE. Relative to the RobT effect, idiopathic alterations in spermatogenesis in 46,XY patients appear to be more harmful for meiosis. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Restriction Theorem for Principal bundles in Arbitrary Characteristic

DEFF Research Database (Denmark)

Gurjar, Sudarshan

2015-01-01

The aim of this paper is to prove two basic restriction theorem for principal bundles on smooth projective varieties in arbitrary characteristic generalizing the analogues theorems of Mehta-Ramanathan for vector bundles. More precisely, let G be a reductive algebraic group over an algebraically...... closed field k and let X be a smooth, projective variety over k together with a very ample line bundle O(1). The main result of the paper is that if E is a semistable (resp. stable) principal G-bundle on X w.r.t O(1), then the restriction of E to a general, high multi-degree, complete-intersection curve...

Does breastfeeding influence future sperm quality and reproductive hormones?

DEFF Research Database (Denmark)

Laustsen, J M; Jensen, M S; Thulstrup, Ane Marie

2011-01-01

was not statistically significantly associated with sperm concentration, total sperm count, sperm motility or morphology, oligozoospermia, follicle-stimulating hormone, inhibin B, luteinizing hormone, sex hormone-binding globulin (SHBG), the calculated level of free testosterone, free oestradiol, the free testosterone...... testosterone nor free oestradiol was different between the two groups. This study shows no association between breastfeeding and sperm quality or reproductive hormones and a strong association is unlikely. A larger study would be needed to detect more subtle effects....

Wave equations on a de Sitter fiber bundle. [Semiclassical wave function, bundle space, L-S coupling

Energy Technology Data Exchange (ETDEWEB)

Drechsler, W [Max-Planck-Institut fuer Physik und Astrophysik, Muenchen (F.R. Germany)

1975-01-01

A gauge theory of strong interaction is developed based on fields defined on a fiber bundle. The structural group of the bundle is taken to be the Lsub(4,1) de Sitter group. An internal variable xi, varying in the fiber over a space-time point x, is introduced as a means to describe - with the help of a semiclassical wave function psi(x,xi) defined on the bundle space - the internal structure of extended hadrons in a framework using differential geometric techniques. Three basic nonlinear wave equations for psi(x,xi) are established which are of integro-differential type. The nonlinear coupling terms in these de Sitter gauge invariant equations represent physically a generalized spin orbit coupling or a generalized spin coupling for the motion taking place in the fiber. The motivation for using a bigger space for the definition of hadronic matter wave functions as well as the implications of this geometric approach to strong interaction physics is discussed in detail, in particular with respect to the problem of hadronic constituents. The proposed fiber bundle formalism allows a dynamical description of extended structures for hadrons without implying the necessity of introducing any constituents.

Upward swimming of a sperm cell in shear flow.

Science.gov (United States)

Omori, Toshihiro; Ishikawa, Takuji

2016-03-01

Mammalian sperm cells are required to swim over long distances, typically around 1000-fold their own length. They must orient themselves and maintain a swimming motion to reach the ovum, or egg cell. Although the mechanism of long-distance navigation is still unclear, one possible mechanism, rheotaxis, was reported recently. This work investigates the mechanism of the rheotaxis in detail by simulating the motions of a sperm cell in shear flow adjacent to a flat surface. A phase diagram was developed to show the sperm's swimming motion under different shear rates, and for varying flagellum waveform conditions. The results showed that, under shear flow, the sperm is able to hydrodynamically change its swimming direction, allowing it to swim upwards against the flow, which suggests that the upward swimming of sperm cells can be explained using fluid mechanics, and this can then be used to further understand physiology of sperm cell navigation.

Sperm banking for fertility preservation: a 20-year experience.

Science.gov (United States)

Johnson, Matrika D; Cooper, Amber R; Jungheim, Emily S; Lanzendorf, Susan E; Odem, Randall R; Ratts, Valerie S

2013-09-01

Sperm banking is an effective method to preserve fertility, but is not universally offered to males facing gonadotoxic treatment in the United States. We compared the disposition and semen parameters of cryopreserved sperm from individuals referred for sperm banking secondary to a cancer diagnosis to those of sperm from men banking for infertility reasons. We performed a retrospective cohort study that reviewed 1118 records from males who presented to bank sperm at Washington University between 1991 and 2010. We collected and analyzed demographics, semen parameters, and disposition of banked sperm. Four hundred and twenty-three men with cancer and 348 banking for infertility reasons attempted sperm cryopreservation in our unit during the specified time period. The most prevalent cancers in our cohort were testicular (32%), lymphoma (25%), and leukemia (11%). Patients with leukemia had the lowest pre-thaw counts and motility. Most cancer patients (57%) who banked elected to use, transfer to another facility, or keep their specimens in storage. The remaining samples were discarded electively (34%) or following death (8%). Overall semen parameters were similar between the cancer and infertility groups, but demographics, ability to bank a sample, azoospermia rates, length of storage, current banking status, and use of banked sperm differed significantly between the two groups. The majority of cancer patients who banked survived their cancer and chose to continue storage of banked samples. Cancer patients were more likely than infertility patients to use or continue storage of banked samples. Our study provides evidence that sperm banking is a utilized modality of fertility preservation in patients with a myriad of cancer diagnoses and should be offered to all men facing gonadotoxic therapies. Further work is needed to determine where disparities in access to sperm banking exist to improve the potential for future fertility in these males. Copyright © 2013 Elsevier

[Study on sperm damage caused by trichloroethylene in male rats].

Science.gov (United States)

Wu, De-sheng; Yang, Lin-qing; Huang, Sui; Liu, Jian-jun; Xu, Xin-yun; Huang, Hai-yan; Gong, Chun-mei; Hu, Gong-hua; Liu, Qing-cheng; Yang, Xi-fei; Hong, Wen-xu; Zhou, Li; Huang, Xin-feng; Yuan, Jian-hui; Zhuang, Zhi-xiong

2013-11-01

To study in vitro sperm damage caused by trichloroethylene in male rats. Sperms of Sprague-Dawley (SD) rats were collected 4 hours after being contaminated by trichloroethylene of 0, 2, 4, 6, 8, and 10 mmol/L in vitro. Giemsa staining was performed to observe the morphological changes of sperms, and flow cytometer was used to detect the changes in mitochondrial membrane potential. The sperm motilities in 6, 8, and 10 mmol/L trichloroethylene groups decreased significantly compared with that in control group (P trichloroethylene groups were significantly higher than that in control group (Ptrichloroethylene groups and control group (Ptrichloroethylene can reduce sperm motility and increase the aberration rate and apoptosis rate of sperms in male SD rats.

Relativistic rotators: a quantum mechanical de Sitter bundle

International Nuclear Information System (INIS)

Boehm, A.

1976-02-01

If de Sitter fiber bundle over space time is the classical picture of hadrons then for a quantum mechanical description one has to generalize the concept of a principal fiber bundle to a bundle that contains the representation of the group of motion. This idea is related to the relativistic rotator model, and the radius of the de Sitter fiber is determined from the experimental hadron spectrum

Enhancement of mouse sperm motility by trophinin-binding peptide

Directory of Open Access Journals (Sweden)

Park Seong

2012-11-01

Full Text Available Abstract Background Trophinin is an intrinsic membrane protein that forms a complex in the cytoplasm with bystin and tastin, linking it microtubule-associated motor dynein (ATPase in some cell types. Previously, we found that human sperm tails contain trophinin, bystin and tastin proteins, and that trophinin-binding GWRQ (glycine, tryptophan, arginine, glutamine peptide enhanced motility of human sperm. Methods Immunohistochemistry was employed to determine trophinin protein in mouse spermatozoa from wild type mouse, by using spermatozoa from trophinin null mutant mice as a negative control. Multivalent 8-branched GWRQ (glycine, tryptophan, arginine, glutamine peptide or GWRQ-MAPS, was chemically synthesized, purified by HPLC and its structure was confirmed by MALDI-TOF mass spectrometry. Effect of GWRQ-MAPS on mouse spermatozoa from wild type and trophinin null mutant was assessed by a computer-assisted semen analyzer (CASA. Results Anti-trophinin antibody stained the principal (central piece of the tail of wild type mouse sperm, whereas the antibody showed no staining on trophinin null sperm. Phage particles displaying GWRQ bound to the principal piece of sperm tail from wild type but not trophinin null mice. GWRQ-MAPS enhanced motility of spermatozoa from wild type but not trophinin null mice. CASA showed that GWRQ-MAPS enhanced both progressive motility and rapid motility in wild type mouse sperm. Conclusions Present study established the expression of trophinin in the mouse sperm tail and trophinin-dependent effect of GWRQ-MAPS on sperm motility. GWRQ causes a significant increase in sperm motility.

Successful long-term preservation of rat sperm by freeze-drying.

Directory of Open Access Journals (Sweden)

Takehito Kaneko

Full Text Available BACKGROUND: Freeze-drying sperm has been developed as a new preservation method where liquid nitrogen is no longer necessary. An advantage of freeze-drying sperm is that it can be stored at 4 °C and transported at room temperature. Although the successful freeze-drying of sperm has been reported in a number of animals, the possibility of long-term preservation using this method has not yet been studied. METHODOLOGY/PRINCIPAL FINDINGS: Offspring were obtained from oocytes fertilized with rat epididymal sperm freeze-dried using a solution containing 10 mM Tris and 1 mM EDTA adjusted to pH 8.0. Tolerance of testicular sperm to freeze-drying was increased by pre-treatment with diamide. Offspring with normal fertility were obtained from oocytes fertilized with freeze-dried epididymal sperm stored at 4 °C for 5 years. CONCLUSIONS AND SIGNIFICANCE: Sperm with -SS- cross-linking in the thiol-disulfide of their protamine were highly tolerant to freeze-drying, and the fertility of freeze-dried sperm was maintained for 5 years without deterioration. This is the first report to demonstrate the successful freeze-drying of sperm using a new and simple method for long-term preservation.

Sperm count. Do we need a new reference value?

Science.gov (United States)

Cardona Maya, Walter

2010-03-01

To evaluate the sperm count in fertile men, general population, and infertile men in different regions of the world. Sperm counts were recorded according to their fertility status, proven fertility, men recruited from an andrology/infertility clinic, or healthy men. The average of sperm count in the different studies is lower in infertile men that in fertile men (p>0.001) and in the general population (p>0.001). Based on this analysis the normal sperm count is about 65 million per mL. Using these reference value, only the 25% of the studies in infertile men are above this value, and the 75% studies with fertile men (>65 x 106 sperm/mL).

Seasonal variation of sperm quality and the relationship between spermatocrit and sperm concentration in yamú Brycon amazonicus

DEFF Research Database (Denmark)

Cruz-Casallas, Pablo E.; Medina-Robles, Víctor M.; Velasco-Santamaría, Yohana M.

2007-01-01

and sperm concentration were examined over two reproductive seasons. Activation time, spermatocrit, and sperm concentration were significantly higher in 2003 than in 2004. Spermatocrit and sperm concentration showed a significant positive relationship (r2=0.79). During the 2004 reproductive season......, a significant variation was observed for spermatocrit and sperm concentration between the initial period (February 15th to March 14th) and the middle and final periods (March 15th to April 14th and April 15th to May 14th, respectively). Neither the ion concentrations nor the glucose and cholesterol...... concentrations varied between any periods of the reproductive season. Osmolality and triglyceride concentrations showed significant variations between periods during the reproductive season....

Dietary fatty acids influence sperm quality and function.

Science.gov (United States)

Ferramosca, A; Moscatelli, N; Di Giacomo, M; Zara, V

2017-05-01

Recently, obesity has been linked to male infertility. In animal models the administration of a high-fat diet caused a reduction in sperm quality, by impairing gamete energy metabolism. The aim of this study was to investigate a possible effect of dietary fatty acids supplementation in the modulation of sperm energy metabolism and, in turn, in the improvement of sperm quality in rats fed a high-fat diet. Sexually mature male Sprague-Dawley rats were divided into four groups and fed for 4 weeks a standard diet (control group), a high-fat diet (enriched in 35% of fat and 15% sucrose), a high-fat diet supplemented with 2.5% olive oil (a source of monounsaturated fatty acids) or a high-fat diet supplemented with 2.5% krill oil (a source of n-3 polyunsaturated fatty acids). Liver and adipose tissue weight, plasma glucose, insulin and lipid concentrations were determined. Activities of enzymes involved in sperm energetic metabolism were evaluated by spectrophotometric assays. Sperm mitochondrial respiratory efficiency was also assayed. The obtained results suggest that olive oil partially counteracts the negative effects of a high-fat diet on sperm quality, by increasing gamete motility, by reducing oxidative stress and slightly improving mitochondrial respiration efficiency. On the other hand, krill oil determines an increase in sperm concentration and motility, an increase in the activities of lactate dehydrogenase, Krebs cycle enzymes and respiratory chain complexes; a parallel increase in the cellular levels of ATP and a reduction in oxidative damage were also observed. These results suggest that dietary fatty acids are able to positively influence sperm quality and function. © 2017 American Society of Andrology and European Academy of Andrology.

Sperm viability staining in ecology and evolution: potential pitfalls

DEFF Research Database (Denmark)

Holman, Luke

2009-01-01

The causes and consequences of variation in sperm quality, survival and ageing are active areas of research in ecology and evolution. In order to address these topics, many recent studies have measured sperm viability using fluorescent staining. Although sperm viability staining has produced a nu...

Deduction of a calcium ion circuit affecting rooster sperm in vitro.

Science.gov (United States)

Froman, D P

2016-08-01

Four premises for rooster sperm preservation were outlined previously. Understanding mitochondrial Ca cycling in terms of whole-cell Ca flux was one premise. The present work tested the hypothesis that sperm mitochondria can be damaged by intracellular as well as extracellular Ca. Sperm were washed by centrifugation through 12% (wt/vol) Sperm were washed by centrifugation through 12%(at/vol) Accudenz to procure sperm at a physiological concentration within a chemically-defined suspension. Five solutions were tested. Each solution contained 30 m glucose, and had an osmolality of 320 mmol/kg and a pH of 7.4. Washed sperm were diluted to 2.0 × 10 sperm/mL. Each replicate sperm suspension was cooled to 10°C. Sperm mobility was measured after 1, 2, 4, 8, 12, and 24 h. Data were plotted as a function of time in each experiment. Function type was confirmed by lack of fit analysis. A parabola with a maximum at 3.7 h was observed when sperm were suspended in 205 m taurine buffered with 50 m-tris[hydroxyl-methyl]methyl-2-amino-ethanesulfonic acid (TES). This effect was attributed to a Ca flux from the nuclear envelope into mitochondria. An exponential decay was observed when TES-buffered taurine contained 2 m Ca. This effect was attributed to mitochondrial Ca overload induced by uptake of extracellular Ca. Exponential decay also was observed when TES-buffered taurine contained a Ca chelator. This effect was attributed to a Ca flux from the nuclear envelope through mitochondria and then into an extracellular Ca sink. This possibility was supported by the response of sperm to thapsigargin. Specifically, inhibition of sarcoendoplasmic reticulum Ca-ATPase compromised sperm mobility relative to a buffer control. Finally, a 60 m phosphate buffer containing 2 m citrate yielded a linear relationship in contrast to the TES-buffered solutions tested. Sperm mobility after 24 h of storage in the phosphate buffer was 92% of that observed for prewashed sperm. The linear response was

Bundling Actin Filaments From Membranes: Some Novel Players

Directory of Open Access Journals (Sweden)

Clément eThomas

2012-08-01

Full Text Available Progress in live-cell imaging of the cytoskeleton has significantly extended our knowledge about the organization and dynamics of actin filaments near the plasma membrane of plant cells. Noticeably, two populations of filamentous structures can be distinguished. On the one hand, fine actin filaments which exhibit an extremely dynamic behavior basically characterized by fast polymerization and prolific severing events, a process referred to as actin stochastic dynamics. On the other hand, thick actin bundles which are composed of several filaments and which are comparatively more stable although they constantly remodel as well. There is evidence that the actin cytoskeleton plays critical roles in trafficking and signaling at both the cell cortex and organelle periphery but the exact contribution of actin bundles remains unclear. A common view is that actin bundles provide the long-distance tracks used by myosin motors to deliver their cargo to growing regions and accordingly play a particularly important role in cell polarization. However, several studies support that actin bundles are more than simple passive highways and display multiple and dynamic roles in the regulation of many processes, such as cell elongation, polar auxin transport, stomatal and chloroplast movement, and defense against pathogens. The list of identified plant actin-bundling proteins is ever expanding, supporting that plant cells shape structurally and functionally different actin bundles. Here I review the most recently characterized actin-bundling proteins, with a particular focus on those potentially relevant to membrane trafficking and/or signaling.

Variation in sperm morphology among Afrotropical sunbirds

Czech Academy of Sciences Publication Activity Database

Omotoriogun, T. C.; Laskemoen, T.; Rowe, M.; Albrecht, Tomáš; Bowie, R. C. K.; Sedláček, O.; Hořák, D.; Ottosson, U.; Lifjeld, J. T.

2016-01-01

Roč. 158, č. 1 (2016), s. 155-166 ISSN 0019-1019 Institutional support: RVO:68081766 Keywords : comparative analysis * Nectariniidae * phylogenetic signal * sperm competition * sperm size Subject RIV: EG - Zoology Impact factor: 2.279, year: 2016

Sperm quality and cryopreservation of Brazilian freshwater fish species: a review.

Science.gov (United States)

Viveiros, A T M; Godinho, H P

2009-03-01

The Brazilian freshwater fish diversity is the richest in the world. Only 0.7% of all Brazilian species have had any aspect of their sperm biology addressed up to this date. The majority of the fish species described in this review migrate during the spawning season (a phenomenon known as piracema). Urbanization, pollution, hydroelectric dams and deforestation are some of the causes of stock depletion or even local extinction of some of these species. The knowledge concerning sperm quality and minimum sperm:egg ratio is important to maximize the use of males without reducing hatching rates. Furthermore, sperm cryopreservation and gene banking can guarantee the conservation of genetic diversity and development of adequate breeding programs of native fish species. In this review, we present and evaluate the existing information on Brazilian fish species that have been subject to sperm quality and cryopreservation studies. The following parameters were evaluated: volume of extractable sperm, sperm motility, sperm concentration, freezing media, freezing methods, and post-thaw sperm quality. Although the existing protocols yield relatively high post-thaw motility and fertilization rates, the use of cryopreserved sperm in routine hatchery production is still limited in Brazil.

Polyandrous females provide sons with more competitive sperm: Support for the sexy-sperm hypothesis in the rattlebox moth (Utetheisa ornatrix).

Science.gov (United States)

Egan, Andrea L; Hook, Kristin A; Reeve, H Kern; Iyengar, Vikram K

2016-01-01

Given the costs of multiple mating, why has female polyandry evolved? Utetheisa ornatrix moths are well suited for studying multiple mating in females because females are highly polyandrous over their life span, with each male mate transferring a substantial spermatophore with both genetic and nongenetic material. The accumulation of resources might explain the prevalence of polyandry in this species, but another, not mutually exclusive, possibility is that females mate multiply to increase the probability that their sons will inherit more-competitive sperm. This latter "sexy-sperm" hypothesis posits that female multiple mating and male sperm competitiveness coevolve via a Fisherian runaway process. We tested the sexy-sperm hypothesis by using competitive double matings to compare the sperm competition success of sons of polyandrous versus monandrous females. In accordance with sexy-sperm theory, we found that in 511 offspring across 17 families, the male whose polyandrous mother mated once with each of three different males sired significantly more of all total offspring (81%) than did the male whose monandrous mother was mated thrice to a single male. Interestingly, sons of polyandrous mothers had a significantly biased sex ratio of their brood toward sons, also in support of the hypothesis. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

Science.gov (United States)

Cortés-Gutiérrez, Elva I.; López-Fernández, Carmen; Fernández, José Luis; Dávila-Rodríguez, Martha I.; Johnston, Stephen D.; Gosálvez, Jaime

2014-01-01

Key Concepts The two-dimensional Two-Tailed Comet assay (TT-comet) protocol is a valuable technique to differentiate between single-stranded (SSBs) and double-stranded DNA breaks (DSBs) on the same sperm cell.Protein lysis inherent with the TT-comet protocol accounts for differences in sperm protamine composition at a species-specific level to produce reliable visualization of sperm DNA damage.Alkaline treatment may break the sugar–phosphate backbone in abasic sites or at sites with deoxyribose damage, transforming these lesions into DNA breaks that are also converted into ssDNA. These lesions are known as Alkali Labile Sites “ALSs.”DBD–FISH permits the in situ visualization of DNA breaks, abasic sites or alkaline-sensitive DNA regions.The alkaline comet single assay reveals that all mammalian species display constitutive ALS related with the requirement of the sperm to undergo transient changes in DNA structure linked with chromatin packing.Sperm DNA damage is associated with fertilization failure, impaired pre-and post- embryo implantation and poor pregnancy outcome.The TT is a valuable tool for identifying SSBs or DSBs in sperm cells with DNA fragmentation and can be therefore used for the purposes of fertility assessment. Sperm DNA damage is associated with fertilization failure, impaired pre-and post- embryo implantation and poor pregnancy outcome. A series of methodologies to assess DNA damage in spermatozoa have been developed but most are unable to differentiate between single-stranded DNA breaks (SSBs) and double-stranded DNA breaks (DSBs) on the same sperm cell. The two-dimensional Two-Tailed Comet assay (TT-comet) protocol highlighted in this review overcomes this limitation and emphasizes the importance in accounting for the difference in sperm protamine composition at a species-specific level for the appropriate preparation of the assay. The TT-comet is a modification of the original comet assay that uses a two dimensional electrophoresis to

NIF laser bundle review. Final report

International Nuclear Information System (INIS)

Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

1995-01-01

We performed additional bundle review effort subsequent to the completion of the preliminary report and are revising our original recommendations. We now recommend that the NIF baseline laser bundle size be changed to the 4x2 bundle configuration. There are several 4x2 bundle configurations that could be constructed at a cost similar to that of the baseline 4x12 (from $11M more to about $11M less than the baseline; unescalated, no contingency) and provide significant system improvements. We recommend that the building cost estimates (particularly for the in-line building options) be verified by an architect/engineer (A/E) firm knowledgeable about building design. If our cost estimates of the in-line building are accurate and therefore result in a change from the baseline U-shaped building layout, the acceptability of the in-line configuration must be reviewed from an operations viewpoint. We recommend that installation, operation, and maintenance of all laser components be reviewed to better determine the necessity of aisles, which add to the building cost significantly. The need for beam expansion must also be determined since it affects the type of bundle packing that can be used and increases the minimum laser bay width. The U-turn laser architecture (if proven viable) offers a reduction in building costs since this laser design is shorter than the baseline switched design and requires a shorter laser bay

Image-Based Edge Bundles : Simplified Visualization of Large Graphs

NARCIS (Netherlands)

Telea, A.; Ersoy, O.

2010-01-01

We present a new approach aimed at understanding the structure of connections in edge-bundling layouts. We combine the advantages of edge bundles with a bundle-centric simplified visual representation of a graph's structure. For this, we first compute a hierarchical edge clustering of a given graph

First production of larvae using cryopreserved sperm: Effects of preservation temperature and cryopreservation on European eel sperm fertilization capacity

DEFF Research Database (Denmark)

Asturiano, J.F.; Sørensen, Sune Riis; Perez, L.

2016-01-01

Sperm cryopreservation is a useful tool in captive fish reproduction management, that is to synchronize gamete production, especially in the case of species as the European eel, where the time of female spawning readiness is unpredictable. Several protocols to cryopreserve sperm of this species....... Fertilization of two egg batches was attempted. Diluted sperm caused a similar percentage of fertilized eggs and a similar number of embryos and larvae, independently of storage temperature (4 or 20°C). The cryopreserved sperm resulted in a lower percentage of fertilized eggs, but embryos developed and a few...... larvae ('cryolarvae') were obtained 55 h after fertilization in one of the two egg batches. This result evidences that the tested cryopreservation protocol is applicable for eel reproduction management, although improvements will be required to enhance fertilization success...

Etiologies of sperm oxidative stress

Directory of Open Access Journals (Sweden)

Parvin Sabeti

2016-04-01

Full Text Available Sperm is particularly susceptible to reactive oxygen species (ROS during critical phases of spermiogenesis. However, the level of seminal ROS is restricted by seminal antioxidants which have beneficial effects on sperm parameters and developmental potentials. Mitochondria and sperm plasma membrane are two major sites of ROS generation in sperm cells. Besides, leukocytes including polymer phonuclear (PMN leukocytes and macrophages produce broad category of molecules including oxygen free radicals, non-radical species and reactive nitrogen species. Physiological role of ROS increase the intracellular cAMP which then activate protein kinase in male reproductive system. This indicates that spermatozoa need small amounts of ROS to acquire the ability of nuclear maturation regulation and condensation to fertilize the oocyte. There is a long list of intrinsic and extrinsic factors which can induce oxidative stress to interact with lipids, proteins and DNA molecules. As a result, we have lipid peroxidation, DNA fragmentation, axonemal damage, denaturation of the enzymes, over generation of superoxide in the mitochondria, lower antioxidant activity and finally abnormal spermatogenesis. If oxidative stress is considered as one of the main cause of DNA damage in the germ cells, then there should be good reason for antioxidant therapy in these conditions

Fiber bundle geometry and space-time structure

International Nuclear Information System (INIS)

Nascimento, J.C.

1977-01-01

Within the framework of the geometric formulation of Gauge theories in fiber bundles, the general relation between the bundle connection (Gauge field) and the geometry of the base space is obtained. A possible Gauge theory for gravitation is presented [pt

Reproductive-tactic-specific variation in sperm swimming speeds in a shell-brooding cichlid.

Science.gov (United States)

Fitzpatrick, J L; Desjardins, J K; Milligan, N; Montgomerie, R; Balshine, S

2007-08-01

Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics in Telmatochromis vittatus, a small shell-brooding cichlid fish endemic to Lake Tanganyika. Males exhibit four different reproductive tactics: pirate, territorial, satellite, and sneaker. Pirate males temporarily displace all other competing males from a shell nest, whereas sneaker males always release sperm in the presence of territorial and satellite males. Due to the fact that sneakers spawn in the presence of another male, sneakers face the highest levels of sperm competition and pirates the lowest, whereas satellites and territorials experience intermediate levels. In accordance with predictions, sperm from sneakers swam faster than sperm from males adopting the other reproductive tactics, whereas sperm from pirates was slowest. Interestingly, we were unable to detect any variation in sperm tail length among these reproductive tactics. Thus, sperm competition appears to have influenced sperm energetics in this species without having any influence on sperm size.

Temporal trends in sperm count

DEFF Research Database (Denmark)

Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson

2017-01-01

a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years.......006, respectively). WIDER IMPLICATIONS: This comprehensive meta-regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because......BACKGROUND: Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. OBJECTIVE AND RATIONALE: To provide a systematic review and meta-regression...

Triviality and Split of Vector Bundles on Rationally Connected Varieties

OpenAIRE

Pan, Xuanyu

2013-01-01

In this paper, we give a simple proof of a triviality criterion due to I.Biswas and J.Pedro and P.Dos Santos. We also prove a vector bundle on a homogenous space is trivial if and only if the restrictions of the vector bundle to Schubert lines are trivial. Using this result and Chern classes of vector bundles, we give a general criterion of a uniform vector bundle on a homogenous space to be splitting. As an application, we prove a uniform vector bundle on classical Grassmannians and quadrics...

CANDU fuel bundle deformation modelling with COMSOL multiphysics

International Nuclear Information System (INIS)

Bell, J.S.; Lewis, B.J.

2012-01-01

Highlights: ► The deformation behaviour of a CANDU fuel bundle was modelled. ► The model has been developed on a commercial finite-element platform. ► Pellet/sheath interaction and end-plate restraint effects were considered. ► The model was benchmarked against the BOW code and a variable-load experiment. - Abstract: A model to describe deformation behaviour of a CANDU 37-element bundle has been developed under the COMSOL Multiphysics finite-element platform. Beam elements were applied to the fuel elements (composed of fuel sheaths and pellets) and endplates in order to calculate the bowing behaviour of the fuel elements. This model is important to help assess bundle-deformation phenomena, which may lead to more restrictive coolant flow through the sub-channels of the horizontally oriented bundle. The bundle model was compared to the BOW code for the occurrence of a dry-out patch, and benchmarked against an out-reactor experiment with a variable load on an outer fuel element.

Wire-wrap bundle compression-characteristics study. Phase I

International Nuclear Information System (INIS)

Chertock, A.J.

1974-06-01

An analytical computer comparison was made of the compression characteristics of proposed wire-wrap bundles. The study included analysis of 7- and 37-rod straight-start bundles (base configuration), and softened 37-rod configurations. The softened configurations analyzed were: straight-start with distributed wireless fuel rods, and the staggered wire-wrap start angles of 0 0 -30 0 -60 0 and 0 0 -45 0 -90 0 . The compression of the bundle simulates the bundle-to-channel interference at end-of-life conditions at which high differential swelling between the channel and bundle has been predicted. The computer results do not include the so-called dispersion effects. The effects of other variables such as pitch length, creep, axial variations in swelling, and degree of swelling were not studied. These analytic studies give an indication of trends only. No credence should be given to specific quantitative load or deflection results quoted in this report

Right bundle branch block

DEFF Research Database (Denmark)

Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

2013-01-01

AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included...... in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.......5%/2.3% in women, P block was associated with significantly...

Comparison of sperm subpopulation structures in first and second ejaculated semen from Japanese black bulls by a cluster analysis of sperm motility evaluated by a CASA system.

Science.gov (United States)

Kanno, Chihiro; Sakamoto, Kentaro Q; Yanagawa, Yojiro; Takahashi, Yoshiyuki; Katagiri, Seiji; Nagano, Masashi

2017-08-04

In the present study, bull sperm in the first and second ejaculates were divided into subpopulations based on their motility characteristics using a cluster analysis of data from computer-assisted sperm motility analysis (CASA). Semen samples were collected from 4 Japanese black bulls. Data from 9,228 motile sperm were classified into 4 clusters; 1) very rapid and progressively motile sperm, 2) rapid and circularly motile sperm with widely moving heads, 3) moderately motile sperm with heads moving frequently in a short length, and 4) poorly motile sperm. The percentage of cluster 1 varied between bulls. The first ejaculates had a higher proportion of cluster 2 and lower proportion of cluster 3 than the second ejaculates.

Cryopreservation of donkey sperm using non-permeable cryoprotectants.

Science.gov (United States)

Diaz-Jimenez, M; Dorado, J; Ortiz, I; Consuegra, C; Pereira, B; Gonzalez-De Cara, C A; Aguilera, R; Mari, G; Mislei, B; Love, C C; Hidalgo, M

2018-02-01

The aim of this study was to evaluate the effect of different concentrations of sucrose combined with bovine serum albumin (BSA), as non-permeable cryoprotectants, on donkey sperm parameters after cryopreservation, in comparison to a control extender containing glycerol. Semen from five Andalusian donkeys (n = 12) were centrifuged and resuspended with a commercial extender for equine sperm (Gent A, Minitube) adding 1% BSA and different concentrations (M, mol/l) of water-diluted sucrose: 0.05, 0.1, 0.25, 0.35 and 0.45. Thereafter, semen (n = 24) were diluted in the same base extender containing 0.25 M sucrose (S25) or glycerol (GLY, Gent B). Sperm were slowly cooled, filled in 0.5 ml straws and frozen in nitrogen vapours. Post-thaw samples were assessed for sperm motility, plasma membrane and DNA integrity and results were compared by ANOVA. In Experiment 1, sperm motility was significantly higher (P < 0.001) for S25 than the remaining treatments, and no differences were found for plasma membrane or DNA integrity. In Experiment 2, no differences were found between S25 or GLY for sperm motility and DNA integrity but plasma membrane integrity was significantly higher (P < 0.05) for S25. In conclusion, the extender with sucrose 0.25 M combined with BSA can be considered as an alternative to conventional extenders with glycerol for donkey sperm cryopreservation. Copyright © 2017 Elsevier B.V. All rights reserved.

Design concept and testing of an in-bundle gamma densitometer for subchannel void fraction measurements in the THTF electrically heated rod bundle

International Nuclear Information System (INIS)

Felde, D.K.

1982-04-01

A design concept is presented for an in-bundle gamma densitometer system for measurement of subchannel average fluid density and void fraction in rod or tube bundles. This report describes (1) the application of the design concept to the Thermal-Hydraulic Test Facility (THTF) electrically heated rod bundle; and (2) results from tests conducted in the THTF

Topological T-duality for torus bundles with monodromy

Science.gov (United States)

Baraglia, David

2015-05-01

We give a simplified definition of topological T-duality that applies to arbitrary torus bundles. The new definition does not involve Chern classes or spectral sequences, only gerbes and morphisms between them. All the familiar topological conditions for T-duals are shown to follow. We determine necessary and sufficient conditions for existence of a T-dual in the case of affine torus bundles. This is general enough to include all principal torus bundles as well as torus bundles with arbitrary monodromy representations. We show that isomorphisms in twisted cohomology, twisted K-theory and of Courant algebroids persist in this general setting. We also give an example where twisted K-theory groups can be computed by iterating T-duality.

Evolutionary Modeling Predicts a Decrease in Postcopulatory Sperm Viability as a Response to Increasing Levels of Sperm Competition

NARCIS (Netherlands)

Engqvist, Leif

Sperm competition has been found to have a strong influence on the evolution of many male and female reproductive traits. Theoretical models have shown that, with increasing levels of sperm competition, males are predicted to increase ejaculate investment, and there is ample empirical evidence

Validation of the sperm class analyser CASA system for sperm counting in a busy diagnostic semen analysis laboratory.

Science.gov (United States)

Dearing, Chey G; Kilburn, Sally; Lindsay, Kevin S

2014-03-01

Sperm counts have been linked to several fertility outcomes making them an essential parameter of semen analysis. It has become increasingly recognised that Computer-Assisted Semen Analysis (CASA) provides improved precision over manual methods but that systems are seldom validated robustly for use. The objective of this study was to gather the evidence to validate or reject the Sperm Class Analyser (SCA) as a tool for routine sperm counting in a busy laboratory setting. The criteria examined were comparison with the Improved Neubauer and Leja 20-μm chambers, within and between field precision, sperm concentration linearity from a stock diluted in semen and media, accuracy against internal and external quality material, assessment of uneven flow effects and a receiver operating characteristic (ROC) analysis to predict fertility in comparison with the Neubauer method. This work demonstrates that SCA CASA technology is not a standalone 'black box', but rather a tool for well-trained staff that allows rapid, high-number sperm counting providing errors are identified and corrected. The system will produce accurate, linear, precise results, with less analytical variance than manual methods that correlate well against the Improved Neubauer chamber. The system provides superior predictive potential for diagnosing fertility problems.

Sperm motility in fish: technical applications and perspectives through CASA-Mot systems.

Science.gov (United States)

Gallego, V; Asturiano, J F

2018-03-09

Although a relatively high number of sperm quality biomarkers have been reported over the years in several fish species, sperm motility is nowadays considered the best biomarker for fish spermatozoa. The first scientific reports focusing on fish sperm motility date from a century ago, but the objective assessment allowed by computer-aided sperm analysis (CASA-Mot) systems was not applied to fish species until the mid-1980s. Since then, a high number of sperm kinetic parameters from more than 170 fish species have been reported in more than 700 scientific articles, covering a wide range of topics, such as sperm physiology, sperm storage, broodstock management, the phenomenon of sperm competition, ecotoxicology and understanding the life cycle of the species. The sperm kinetic parameters provided by CASA-Mot systems can serve as powerful and useful tools for aquaculture and ecological purposes, and this review provides an overview of the major research areas in which fish sperm motility assessment by a CASA-Mot system has been used successfully.

Sperm proteins in teleostean and chondrostean (sturgeon) fishes.

Science.gov (United States)

Li, Ping; Hulak, Martin; Linhart, Otomar

2009-11-01

Sperm proteins in the seminal plasma and spermatozoa of teleostean and chondrostean have evolved adaptations due to the changes in the reproductive environment. Analysis of the composition and functions of these proteins provides new insights into sperm motility and fertilising abilities, thereby creating possibilities for improving artificial reproduction and germplasm resource conservation technologies (e.g. cryopreservation). Seminal plasma proteins are involved in the protection of spermatozoa during storage in the reproductive system, whereas all spermatozoa proteins contribute to the swimming and fertilising abilities of sperm. Compared to mammalian species, little data are available on fish sperm proteins and their functions. We review here the current state of the art in this field and focus on relevant subjects that require attention. Future research should concentrate on protein functions and their mode of action in fish species, especially on the role of spermatozoa surface proteins during fertilisation and on a description of sturgeon sperm proteins.

Shape and shear guide sperm cells spiraling upstream

Science.gov (United States)

Kantsler, Vasily; Dunkel, Jorn; Goldstein, Raymond E.

2014-11-01

A major puzzle in biology is how mammalian sperm determine and maintain the correct swimming direction during the various phases of the sexual reproduction process. Currently debated mechanisms for sperm long range travel vary from peristaltic pumping to temperature sensing (thermotaxis) and direct response to fluid flow (rheotaxis), but little is known quantitatively about their relative importance. Here, we report the first quantitative experimental study of mammalian sperm rheotaxis. Using microfluidic devices, we investigate systematically the swimming behavior of human and bull sperm over a wide range of physiologically relevant shear rates and viscosities. Our measurements show that the interplay of fluid shear, steric surface-interactions and chirality of the flagellar beat leads to a stable upstream spiraling motion of sperm cells, thus providing a generic and robust rectification mechanism to support mammalian fertilization. To rationalize these findings, we identify a minimal mathematical model that is capable of describing quantitatively the experimental observations.

Post-Translational Modifications of Histones in Human Sperm.

Science.gov (United States)

Krejčí, Jana; Stixová, Lenka; Pagáčová, Eva; Legartová, Soňa; Kozubek, Stanislav; Lochmanová, Gabriela; Zdráhal, Zbyněk; Sehnalová, Petra; Dabravolski, Siarhei; Hejátko, Jan; Bártová, Eva

2015-10-01

We examined the levels and distribution of post-translationally modified histones and protamines in human sperm. Using western blot immunoassay, immunofluorescence, mass spectrometry (MS), and FLIM-FRET approaches, we analyzed the status of histone modifications and the protamine P2. Among individual samples, we observed variability in the levels of H3K9me1, H3K9me2, H3K27me3, H3K36me3, and H3K79me1, but the level of acetylated (ac) histones H4 was relatively stable in the sperm head fractions, as demonstrated by western blot analysis. Sperm heads with lower levels of P2 exhibited lower levels of H3K9ac, H3K9me1, H3K27me3, H3K36me3, and H3K79me1. A very strong correlation was observed between the levels of P2 and H3K9me2. FLIM-FRET analysis additionally revealed that acetylated histones H4 are not only parts of sperm chromatin but also appear in a non-integrated form. Intriguingly, H4ac and H3K27me3 were detected in sperm tail fractions via western blot analysis. An appearance of specific histone H3 and H4 acetylation and H3 methylation in sperm tail fractions was also confirmed by both LC-MS/MS and MALDI-TOF MS analysis. Taken together, these data indicate that particular post-translational modifications of histones are uniquely distributed in human sperm, and this distribution varies among individuals and among the sperm of a single individual. © 2015 Wiley Periodicals, Inc.

Intrauterine insemination versus fallopian tube sperm perfusion for non-tubal infertility

NARCIS (Netherlands)

Cantineau, Astrid E. P.; Cohlen, Ben J.; Heineman, Maas Jan; Marjoribanks, Jane; Farquhar, Cindy

2013-01-01

Background Intrauterine insemination (IUI) is a common treatment for couples with subfertility that does not involve the fallopian tubes. It is used to bring the sperm close to the released oocyte. Another method of introducing sperm is fallopian tube sperm perfusion (FSP). Fallopian tube sperm

Human sperm degradation of zona pellucida proteins contributes to fertilization.

Science.gov (United States)

Saldívar-Hernández, Analilia; González-González, María E; Sánchez-Tusié, Ana; Maldonado-Rosas, Israel; López, Pablo; Treviño, Claudia L; Larrea, Fernando; Chirinos, Mayel

2015-09-02

The mammalian oocyte extracellular matrix known as the zona pellucida (ZP) acts as a barrier to accomplish sperm fusion with the female gamete. Although penetration of the ZP is a limiting event to achieve fertilization, this is one of the least comprehended stages of gamete interaction. Even though previous studies suggest that proteases of sperm origin contribute to facilitate the passage of sperm through the ZP, in human this process is not yet fully understood. The aim of this study was to determine the ability of human sperm to degrade recombinant human ZP (rhZPs) proteins and to characterize the proteases involved in this process. Purified rhZP2, rhZP3 and rhZP4 proteins were incubated with capacitated sperm and the proteolytic activity was determined by Western blot analysis. To further characterize the proteases involved, parallel incubations were performed in the presence of the protease inhibitors o-phenanthroline, benzamidine and MG-132 meant to block the activity of metalloproteases, serine proteases and the proteasome, respectively. Additionally, protease inhibitors effect on sperm-ZP binding was evaluated by hemizona assay. The results showed that rhZPs were hydrolyzed in the presence of capacitated sperm. O-phenanthroline inhibited the degradation of rhZP3, MG-132 inhibited the degradation of rhZP4 and benzamidine inhibited the degradation of the three proteins under investigation. Moreover, hemizona assays demonstrated that sperm proteasome inhibition impairs sperm interaction with human native ZP. This study suggests that sperm proteasomes could participate in the degradation of ZP, particularly of the ZP4 protein. Besides, metalloproteases may be involved in specific degradation of ZP3 while serine proteases may contribute to unspecific degradation of the ZP. These findings suggest that localized degradation of ZP proteins by sperm is probably involved in ZP penetration and may be of help in understanding the mechanisms of fertilization in humans.

Quantitation of sperm bindable IgA and IgG in seminal fluid.

Science.gov (United States)

Howe, S E; Lynch, D M

1986-05-01

Seminal fluid and serum from 95 infertile males were assayed for sperm bindable immunoglobulins using an indirect ELISA with whole target sperm. The ELISA method was compared to seminal fluid and serum immobilization and agglutination assays (functional assays). In this infertile group, the ELISA assay was positive in 22% of seminal fluids (greater than 1.2 fg IgA/sperm and greater than 0.3 fg IgG/sperm). The seminal fluid antibodies were IgA and had an accompanying elevated IgG component in 78% of patients. There was a 96% correlation between negative seminal fluid functional assays and negative ELISA, and a 95% correlation between positive seminal fluid functional assays and positive ELISA. Positive serum sperm antibody tests were found in 71% of the infertile males with positive seminal fluid sperm antibodies, but 29% of the infertile males with strongly positive IgA seminal fluid sperm antibodies showed normal levels of serum sperm antibodies by either ELISA or functional assays. The ELISA method gives reproducible quantitation of sperm antibodies in seminal fluid and correlates well with accepted functional assays. Comparisons with serum sperm antibody assays suggests that seminal fluid sperm antibody analysis complements the serum analysis of sperm antibodies.

Bundle duct interaction studies for fuel assemblies

International Nuclear Information System (INIS)

Hsia, H.T.S.; Kaplan, S.

1981-06-01

It is known that the wire-wrapped rods and duct in an LMFBR are undergoing a gradual structural distortion from the initially uniform geometry under the combined effects of thermal expansion and irradiation induced swelling and creep. These deformations have a significant effect on flow characteristics, thus causing changes in thermal behavior such as cladding temperature and temperature distribution within a bundle. The temperature distribution may further enhance or retard irradiation induced deformation of the bundle. This report summarizes the results of the continuing effort in investigating the bundle-duct interaction, focusing on the need for the large development plant

Motility and fertilizing ability of cryopreserved Caspian brown trout (Salmo trutta caspius) sperm: Effect of post-thaw storage time and different sperm-to-egg ratios.

Science.gov (United States)

Golshahi, Karim; Shabani, Nariman; Aramli, Mohammad Sadegh; Noori, Elnaz

2015-10-01

This study was designed to test the effect of post-thaw storage time on sperm motility parameters of Caspian brown trout (n=7). Furthermore, we investigated the effect of sperm-to-egg ratios of 100,000:1, 300,000:1 and 600,000:1 on fertility of cryopreserved Caspian brown semen. Quality was assessed by measuring sperm motility parameters and fertilization rates at the eyed and hatching stages. The percentage of post-thawed sperm motility, curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH) were not affected by 60 min of storage, whereas a decrease in straight line velocity (VSL), average path velocity (VAP) and linearity (LIN) were found in cryopreserved semen. Thus, the cryopreserved sperm of Caspian brown trout could be stored up to 60 min without loss of the percentage of sperm motility. The fertilization rate was not affected by 60 min of post-thaw storage and was over 70% for sperm-to-egg ratios of both 300,000 and 600,000:1. To our knowledge, this study is the first to report the high post-thaw fertilization ability of Caspian brown trout semen at a sperm-to-egg ratio as low as 300,000:1. This procedure after scaling up can be recommended for routine Caspian brown trout sperm cryopreservation. Copyright © 2015 Elsevier Inc. All rights reserved.

Cryopreservation of yamú (Brycon amazonicus) sperm for large scale fertilization

DEFF Research Database (Denmark)

Velasco-Santamaría, Yohana M.; Medina-Robles, Mauricio; Cruz-Casallas, Pablo E.

2006-01-01

  To determine the effect of straw size and thawing temperature on cryopreserved sperm quality of yamú (Brycon amazonicus), ovulation and spermiation were induced in sexually mature broodstock using Carp Pituitary Extract. Sperm quality was evaluated by motility, activation time and fertility...... assays consisted of 40 g eggs inseminated with approximately 5.0 mL (ca. 75,000 motile spermatozoa/egg) of cryopreserved sperm in large straws thawed at 35 °C. The fertilization rate was estimated 6 h post-insemination. In all straws, postthaw motility was significantly lower than for fresh sperm (pb0.......05) to sperm frozen in 0.5-mL straws (48±2%, 51±2%, 52±2% and 54±3%, respectively). In large scale fertilization trials, fresh sperm showed a higher (pb0.05) fertilization rate (83±1%) than frozen-thawed sperm (68±1%). Although the fertility percentage with fresh sperm was significantly higher than with frozen...

Effect of 4-nonylphenol on the sperm dynamic parameters ...

African Journals Online (AJOL)

4-Nonylphenol (NP) is a compound that causes endocrine disruption and affects sperm quality of mammals and fish. However, the effects of NP on the sperm and fertilization rate of amphibians remain unknown. This study investigates the in vivo and in vitro effects of NP on the sperm dynamic parameters and fertilization ...

Good Quality - the Routinization of Sperm Banking in China

DEFF Research Database (Denmark)

Wahlberg, Ayo

Good Quality is an assemblage ethnography of how sperm banking came to be routinized in China. Based on 8 years of episodic fieldwork at China’s oldest and largest sperm bank in Changsha, Hunan province, the book meticulously chronicles how, beginning in the early 1980s, a unique style of sperm b...

Development of Domestic Cat Embryo Produced by Preserved Sperms

Directory of Open Access Journals (Sweden)

KARTINI ERIANI

2008-12-01

Full Text Available The ability to mature and fertilize oocytes of endangered species may allow us to sustain genetic and global biodiversity. Epididymis sperms may be the last chance to ensure preservation of genetic materials after injury or death of a valuable animal. Studies have been conducted to determine wether both epididymis sperms and oocytes can be used to produce viable embryos and offspring. The purpose of this study was to determine how long cats sperms contained in epididymis were remain motile and had intact membranes when preserved at 4 ° C, and to determine whether such those preserved sperms are able to fertilize oocytes. Epididymis was preserved immediately in phosphate buffer saline at 4 ° C for 1, 3, and 6 days. The observation of sperm quality and viability after preservation was performed by vital staining acrosom and Hoechst-Propidium Iodine. Biological functions of sperms were evaluated by in vitro culture technique for fertilization, micro fertilization and embryonic development rate in CR1aa medium. The results showed that average motility of sperms collected from ductus deferens, cauda and corpus epididymis decreased not significantly (P > 0.05 from 0, 1, 3, and 6 days of preservation times (from 83.0%, 80.2%, 79.0%; 80.9%, 75.0%, 75.5%; 52.0%, 63.2%, 55.0% to 34.6%, 34.6%, 33.3%, respectively. The general results showed that sperms from epididymis preserved for 1, 3, and 6 days can be used for IVF. The rate of embryonal cleavage produced by IVF technique using sperms collected from epididymis preserved for 1-, 3- and 6-days were 33.3, 26.7, and 20.0%, respectively and significantly different (p < 0.05 from that of controll (50.0%. In conclusion, sperms contained in epididyimis preserved at 4 ° C in PBS (Phospate Buffer Saline for 1-6 days can be used to IVF and in vitro production of cat embryos.

Epididymosomes: transfer of fertility-modulating proteins to the sperm surface

OpenAIRE

Patricia A Martin-DeLeon

2015-01-01

A variety of glycosylphosphatidylinositol (GPI)-linked proteins are acquired on spermatozoa from epididymal luminal fluids (ELF) during sperm maturation. These proteins serve roles in immunoprotection and in key steps of fertilization such as capacitation, acrosomal exocytosis and sperm-egg interactions. Their acquisition on sperm cells is mediated both by membrane vesicles (epididymosomes, EP) which were first reported to dock on the sperm surface, and by lipid carriers which facilitate the ...

Experimental investigation of the coolability of blocked hexagonal bundles

Energy Technology Data Exchange (ETDEWEB)

Hózer, Zoltán, E-mail: zoltan.hozer@energia.mta.hu; Nagy, Imre; Kunstár, Mihály; Szabó, Péter; Vér, Nóra; Farkas, Róbert; Trosztel, István; Vimi, András

2017-06-15

Highlights: • Experiments were performed with electrically heated hexagonal fuel bundles. • Coolability of ballooned VVER-440 type bundle was confirmed up to high blockage rate. • Pellet relocation effect causes delay in the cool-down of the bundle. • The bypass line does not prevent the reflood of ballooned fuel rods. - Abstract: The CODEX-COOL experimental series was carried out in order to evaluate the effect of ballooning and pellet relocation in hexagonal bundles on the coolability of fuel rods after a LOCA event. The effects of blockage geometry, coolant flowrate, initial temperature and axial profile were investigated. The experimental results confirmed that a VVER bundle up to 80% blockage rate remains coolable after a LOCA event under design basis conditions. The ballooned section creates some obstacles for the cooling water during reflood of the bundle, but this effect causes only a short delay in the cooling down of the hot fuel rods. The accumulation of fuel pellet debris in the ballooned volume results in a local power peak, which leads to further slowing down of quench front.

Postcopulatory sexual selection is associated with reduced variation in sperm morphology.

Directory of Open Access Journals (Sweden)

Sara Calhim

2007-05-01

Full Text Available The evolutionary role of postcopulatory sexual selection in shaping male reproductive traits, including sperm morphology, is well documented in several taxa. However, previous studies have focused almost exclusively on the influence of sperm competition on variation among species. In this study we tested the hypothesis that intraspecific variation in sperm morphology is driven by the level of postcopulatory sexual selection in passerine birds.Using two proxy measures of sperm competition level, (i relative testes size and (ii extrapair paternity level, we found strong evidence that intermale variation in sperm morphology is negatively associated with the degree of postcopulatory sexual selection, independently of phylogeny.Our results show that the role of postcopulatory sexual selection in the evolution of sperm morphology extends to an intraspecific level, reducing the variation towards what might be a species-specific 'optimum' sperm phenotype. This finding suggests that while postcopulatory selection is generally directional (e.g., favouring longer sperm across avian species, it also acts as a stabilising evolutionary force within species under intense selection, resulting in reduced variation in sperm morphology traits. We discuss some potential evolutionary mechanisms for this pattern.

Quantitative evaluation of radiation-induced changes in sperm morphology and chromatin distribution

International Nuclear Information System (INIS)

Aubele, M.; Juetting, U.R.; Rodenacker, K.; Gais, P.; Burger, G.; Hacker-Klom, U.

1990-01-01

Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mouse germ cells. Exposure of the gonads to radiation is known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm was performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head, changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show larger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to discriminate sperm 35 dpr. This may be explained by differentiation processes, which take place in different stages during mouse spermatogenesis

Identification Male Fertility Through Abnormalities Sperm Based Morphology (Teratospermia) using Invariant Moment Method

Science.gov (United States)

Syahputra, M. F.; Chairani, R.; Seniman; Rahmat, R. F.; Abdullah, D.; Napitupulu, D.; Setiawan, M. I.; Albra, W.; Erliana, C. I.; Andayani, U.

2018-03-01

Sperm morphology is still a standard laboratory analysis in diagnosing infertility in men. Manually identification of sperm form is still not accurate, the difficulty in seeing the form of the invisible sperm from the digital microscope image is often a weakness in the process of identification and takes a long time. Therefore, male fertility identification application system is needed Through sperm abnormalities based on sperm morphology (teratospermia). The method used is invariant moment method. This study uses 15 data testing and 20 data training sperm image. That the process of male fertility identification through sperm abnormalities based on sperm morphology (teratospermia) has an accuracy rate of 80.77%. Use of time to process Identification of male fertility through sperm abnormalities Based on sperm morphology (teratospermia) during 0.4369 seconds.

Experimental and numerical investigations of BWR fuel bundle inlet flow

International Nuclear Information System (INIS)

Hoashi, E; Morooka, S; Ishitori, T; Komita, H; Endo, T; Honda, H; Yamamoto, T; Kato, T; Kawamura, S

2009-01-01

We have been studying the mechanism of the flow pattern near the fuel bundle inlet of BWR using both flow visualization test and computational fluid dynamics (CFD) simulation. In the visualization test, both single- and multi-bundle test sections were used. The former test section includes only a corner orifice facing two support beams and the latter simulates 16 bundles surrounded by four beams. An observation window is set on the side of the walls imitating the support beams upstream of the orifices in both test sections. In the CFD simulation, as well as the visualization test, the single-bundle model is composed of one bundle with a corner orifice and the multi-bundle model is a 1/4 cut of the test section that includes 4 bundles with the following four orifices: a corner orifice facing the corner of the two neighboring support beams, a center orifice at the opposite side from the corner orifice, and two side orifices. Twin-vortices were observed just upstream of the corner orifice in the multi-bundle test as well as the single-bundle test. A single-vortex and a vortex filament were observed at the side orifice inlet and no vortex was observed at the center orifice. These flow patterns were also predicted in the CFD simulation using Reynolds Stress Model as a turbulent model and the results were in good agreement with the test results mentioned above. (author)

Sperm storage and duration of fertility in female ostriches ( Struthio ...

African Journals Online (AJOL)

, the duration of sperm storage and the fertile period following separation of sexes were investigated by egg break-out and by counting the sperm in the perivitelline membrane (spermOPVL) above the germinal disc (GD) region. Fertilisation ...

Monitoring sperm mitochondrial respiration response in a laser trap using ratiometric fluorescence

Science.gov (United States)

Mei, Adrian; Botvinick, Elliot; Berns, Michael

2005-08-01

Sperm motility is an important area in understanding male infertility. Various techniques, such as the Computer Assisted Sperm Analysis (CASA), have been used to understand sperm motility. Sperm motility is related to the energy (ATP) production of sperm. ATP is produced by the depolarization of the membrane potential of the inner membrane of the mitochondria. In this study, a mitochondrial dye, JC-1, has been used to monitor the energetics of the mitochondria. This fluorescent dye can emit at two different wavelengths, depending on the membrane potential of the mitochondria. It can fluoresce green at low membrane potential and red at high membrane potential. The ratio of the two colors (red/green) allows for an accurate measurement of the change of membrane potential. Various experiments were conducted to quantify the behavior of the dye within the sperm and the reaction of the sperm to trap. Sperm were trapped using laser tweezers. Results have shown that the ratio drops dramatically when sperm are trapped, indicating a depolarization of the membrane. The physiological response to this depolarization is yet to be determined, but the studies indicate that the sperm could have been slightly damaged by the laser. However, knowing that sperm depolarizes their membrane when trapped can help understand how sperm react to their environment and consequently help treat male infertility.

Sperm from sneaker male squids exhibit chemotactic swarming to CO₂.

Science.gov (United States)

Hirohashi, Noritaka; Alvarez, Luis; Shiba, Kogiku; Fujiwara, Eiji; Iwata, Yoko; Mohri, Tatsuma; Inaba, Kazuo; Chiba, Kazuyoshi; Ochi, Hiroe; Supuran, Claudiu T; Kotzur, Nico; Kakiuchi, Yasutaka; Kaupp, U Benjamin; Baba, Shoji A

2013-05-06

Behavioral traits of sperm are adapted to the reproductive strategy that each species employs. In polyandrous species, spermatozoa often form motile clusters, which might be advantageous for competing with sperm from other males. Despite this presumed advantage for reproductive success, little is known about how sperm form such functional assemblies. Previously, we reported that males of the coastal squid Loligo bleekeri produce two morphologically different euspermatozoa that are linked to distinctly different mating behaviors. Consort and sneaker males use two distinct insemination sites, one inside and one outside the female's body, respectively. Here, we show that sperm release a self-attracting molecule that causes only sneaker sperm to swarm. We identified CO2 as the sperm chemoattractant and membrane-bound flagellar carbonic anhydrase as its sensor. Downstream signaling results from the generation of extracellular H(+), intracellular acidosis, and recovery from acidosis. These signaling events elicit Ca(2+)-dependent turning behavior, resulting in chemotactic swarming. These results illuminate the bifurcating evolution of sperm underlying the distinct fertilization strategies of this species. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sperm as microswimmers - navigation and sensing at the physical limit

Science.gov (United States)

Kaupp, Ulrich B.; Alvarez, Luis

2016-11-01

Many cells and microorganisms have evolved a motility apparatus to explore their surroundings. For guidance, these biological microswimmers rely on physical and chemical cues that are transduced by cellular pathways into directed movement - a process called taxis. Only few biological microswimmers have been studied as detailed as sperm from sea urchins. Sperm and eggs are released into the seawater. To enhance the chances of fertilization, eggs release chemical factors - called chemoattractants - that establish a chemical gradient and, thereby, guide sperm to the egg. Sea urchin sperm constitute a unique model system for understanding cell navigation at every level: from molecules to cell behaviours. We will outline the chemotactic signalling pathway of sperm from the sea urchin Arbacia punctulata and discuss how signalling controls navigation in a chemical gradient. Finally, we discuss recent insights into sperm chemotaxis in three dimensions (3D).

Sperm ultrastructure, morphometry, and abnormal morphology in American black bears (Ursus americanus).

Science.gov (United States)

Brito, L F C; Sertich, P L; Stull, G B; Rives, W; Knobbe, M

2010-11-01

The objective of this study was to describe sperm ultrastructure, morphometry, and abnormal morphology in American black bears. Electroejaculation was successful in 53.8% (7/13) of the attempts, but urine contamination was common. Epididymal sperm samples were also obtained from five bears. Sperm had a paddle-like head shape and the ultrastructure was similar to that of most other mammals. The most striking particularity of black bear sperm ultrastructure was a tightening of the nucleus in the equatorial region. Although the differences were not significant in all bears, the overall decrease in sperm nucleus dimensions during transport from the caput epididymis to the cauda suggested increasing compaction of the nucleus during maturation. For ejaculated sperm, nucleus length, width, and base width were 4.9, 3.7, and 1.8 μm, respectively, whereas sperm head length, width, and base width were 6.6, 4.8, and 2.3 μm, and midpiece, tail (including midpiece), and total sperm lengths were 9.8, 68.8, and 75.3 μm. Evaluation of sperm cytoplasmic droplets in the epididymis revealed that proximal droplets start migrating toward a distal position in the caput epididymis and that the process was mostly completed by the time sperm reached the cauda epididymis. The proportion of morphologically normal sperm in the ejaculate was 35.6%; the most prevalent sperm defects were distal cytoplasmic droplets and bent/coiled tails. The morphology of abnormal sperm and the underlying ultrastructural defects were similar to that in other large domestic animals thus suggesting similar underlying pathogenesis of specific sperm defects and similar effects on fertility. Copyright © 2010 Elsevier Inc. All rights reserved.

Output commitment through product bundling: experimental evidence

NARCIS (Netherlands)

Hinloopen, J.; Mueller, W.; Normann, H.T.

2011-01-01

We analyze the impact of product bundling in experimental markets. A firm has monopoly power in one market but faces competition by a second firm in another market. We compare treatments where the monopolist can bundle its two products to treatments where it cannot, and we contrast simultaneous and

On sperm competition games: raffles and roles revisited.

Science.gov (United States)

Mesterton-Gibbons, M

1999-08-01

In principle there are two approaches to modelling a trade-off between the positive and negative outcomes of a behavior: after suitably defining a value for the behavior in the absence of any trade-off, one can either multiply that value by an appropriate discount or subtract an appropriate cost. In a prospective analysis of sperm competition, Parker (Proc. Roy. Soc. Lond. B (1990) 242, 120-126) adopted the multiplicative approach to model the trade-off between the value of a mating and the cost of its acquisition. He obtained two paradoxical results. First, if two males 'know' whether they are first or second to mate, but these roles are assigned randomly, then sperm numbers should be the same for both males whether the 'raffle' for fertilization is fair or unfair. Second, if mating order is constant, then a favored male should expend less on sperm. His results are puzzling not only in terms of intuition about nature, but also in terms of his model's consistency. In other words, they present both an external and an internal paradox. Parker assumed the fairness of the raffle to a disfavored male to be independent of how much sperm a favored male deposits. This article both generalizes Parker's analysis by allowing fairness to decrease with sperm expenditure by the favored male and compares Parker's results to those obtained by the additive approach. In many respects, results are similar. Nevertheless, if the costs of mating are assumed to increase with sperm expenditure but not to depend on the role in which sperm is expended, as Parker assumed, then the additive approach is more fundamentally correct. In particular, Parker's constant-role paradox is an artifact of his approach. His random-role paradox is internally rationalized in terms of standard microeconomic theory. When fairness decreases, however slightly, with sperm expenditure by the favored male, both models demonstrate that the evolutionarily stable strategy is for more sperm to be deposited during a

Double-bundle depiction of the anterior cruciate ligament at 3 Tesla

Energy Technology Data Exchange (ETDEWEB)

Adriaensen, M.E.A.P.M. [Atrium Medical Center Parkstad, Department of Radiology, Heerlen (Netherlands); Hogan, B. [Sports Surgery Clinic, Department of Radiology, Dublin (Ireland); Al-Bulushi, H.I.J. [Armed Forces Hospital, Department of Radiology, Muscat (Oman); Kavanagh, E.C. [Mater Misericordiae Hospital, Department of Radiology, Dublin (Ireland)

2012-07-15

Magnetic resonance imaging on 3 Tesla (3T MRI) with arthroscopic correlation has proven to adequately identify the anteromedial bundle (AMB) and posterolateral bundle (PLB) in cadaver knees. The purpose of this study was to describe the depiction of ACL bundle anatomy on 3T MRI in daily practice. In a retrospective cohort study, we included 50 consecutive patients who underwent standard 3T MRI of the knee and had an intact ACL. Two musculoskeletal radiologists independently reviewed all scans for depiction of ACL bundle anatomy using standardized forms. Descriptive statistics were used. Twenty-three right knees (46%) and 27 left knees (54%) were included in the study. Mean age of the patients was 35 years (range 12 to 68 years); 37 patients were male (74%). ACL bundle anatomy was best depicted in the axial plane in 44 knees (88%) and in the coronal plane in six knees (12%). Two bundles were seen in 47 knees (94%). The AMB was completely seen in 45 knees (90%). The PLB was completely seen in 40 knees (80%). Both bundles were completely seen in 37 knees (76%). The double-bundle anatomy of the ACL is visualized in 94% of patients on 3T MRI. Because of potentially associated clinical benefits, we advocate to report separately on the anteromedial bundle and posterolateral bundle in case of anterior cruciate ligament injury of the knee. (orig.)

Maternal exposure to a mixture of persistent organic pollutants (POPs) affects testis histology, epididymal sperm count and induces sperm DNA fragmentation in mice.

Science.gov (United States)

Khezri, Abdolrahman; Lindeman, Birgitte; Krogenæs, Anette K; Berntsen, Hanne F; Zimmer, Karin E; Ropstad, Erik

2017-08-15

Persistent organic pollutants (POPs) are widespread throughout the environment and some are suspected to induce reproductive toxicity. As animals and humans are exposed to complex mixtures of POPs, it is reasonable to assess how such mixtures could interact with the reproductive system. Our aim is to investigate how maternal exposure to a mixture of 29 different persistent organic pollutants, formulated to mimic the relative POP levels in the food basket of the Scandinavian population, could alter reproductive endpoints. Female mice were exposed via feed from weaning, during pregnancy and lactation in 3 exposure groups (control (C), low (L) and high (H)). Testicular morphometric endpoints, epididymal sperm concentration and sperm DNA integrity were assessed in adult male offspring. We found that the number of tubules, proportion of tubule compartments and epididymal sperm concentration significantly decreased in both POP exposed groups. Epididymal sperm from both POP exposed groups showed increased DNA fragmentation. It is concluded that maternal exposure to a defined POP mixture relevant to human exposure can affect testicular development, sperm production and sperm chromatin integrity. Copyright © 2017 Elsevier Inc. All rights reserved.

Feed-backs among inbreeding, inbreeding depression in sperm traits, and sperm competition can drive evolution of costly polyandry.

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Bocedi, Greta; Reid, Jane M

2017-12-01

Ongoing ambitions are to understand the evolution of costly polyandry and its consequences for species ecology and evolution. Emerging patterns could stem from feed-back dynamics between the evolving mating system and its genetic environment, defined by interactions among kin including inbreeding. However, such feed-backs are rarely considered in nonselfing systems. We use a genetically explicit model to demonstrate a mechanism by which inbreeding depression can select for polyandry to mitigate the negative consequences of mating with inbred males, rather than to avoid inbreeding, and to elucidate underlying feed-backs. Specifically, given inbreeding depression in sperm traits, costly polyandry evolved to ensure female fertility, without requiring explicit inbreeding avoidance. Resulting sperm competition caused evolution of sperm traits and further mitigated the negative effect of inbreeding depression on female fertility. The evolving mating system fed back to decrease population-wide homozygosity, and hence inbreeding. However, the net overall decrease was small due to compound effects on the variances in sex-specific reproductive success and paternity skew. Purging of deleterious mutations did not eliminate inbreeding depression in sperm traits or hence selection for polyandry. Overall, our model illustrates that polyandry evolution, both directly and through sperm competition, might facilitate evolutionary rescue for populations experiencing sudden increases in inbreeding. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Effect of different monosaccharides and disaccharides on boar sperm quality after cryopreservation.

Science.gov (United States)

Gómez-Fernández, José; Gómez-Izquierdo, Emilio; Tomás, Cristina; Mocé, Eva; de Mercado, Eduardo

2012-07-01

The aim of the present study was to evaluate the cryoprotectant effect of different non-permeating sugars for boar sperm. Pooled semen from three boars was used for the experiments. In the first experiment, the sperm quality of boar sperm cryopreserved with an egg-yolk based extender supplemented with different monosaccharides (glucose, galactose or fructose) was compared to a control cryopreserved in lactose-egg yolk extender. In the second experiment, the effect of five disaccharides (lactose, sucrose, lactulose, trehalose or melibiose) on boar sperm cryosurvival was studied. Several sperm quality parameters were assessed by flow cytometry in samples incubated for 30 and 150 min at 37°C after thawing: percentages of sperm with intact plasma membrane (SIPM), sperm presenting high plasma membrane fluidity (HPMF), sperm with intracellular reactive oxygen substances production (IROSP) and apoptotic sperm (AS). In addition, the percentages of total motile (TMS) and progressively motile sperm (PMS) were assessed at the same incubation times with a computer-assisted sperm analysis system. Freezing extenders supplemented with each of the monosaccharide presented smaller cryoprotective effect than the control extender supplemented with lactose (Pextender supplemented with lactulose exhibited in general the lowest sperm quality, except for the percentage of capacitated sperm, which was highest (Pextender. Our results suggest that disaccharides have higher cryoprotective effect than monosaccharides, although the monosaccharide composition of the disaccharides is also important, since the best results were obtained with those disaccharides presenting glucose in their composition. Copyright © 2012 Elsevier B.V. All rights reserved.

Geometry of Quantum Principal Bundles. Pt. 1

International Nuclear Information System (INIS)

Durdevic, M.

1996-01-01

A theory of principal bundles possessing quantum structure groups and classical base manifolds is presented. Structural analysis of such quantum principal bundles is performed. A differential calculus is constructed, combining differential forms on the base manifold with an appropriate differential calculus on the structure quantum group. Relations between the calculus on the group and the calculus on the bundle are investigated. A concept of (pseudo)tensoriality is formulated. The formalism of connections is developed. In particular, operators of horizontal projection, covariant derivative and curvature are constructed and analyzed. Generalizations of the first Structure Equation and of the Bianchi identity are found. Illustrative examples are presented. (orig.)

New permeable cryoprotectant-free vitrification method for native human sperm.

Science.gov (United States)

Aizpurua, J; Medrano, L; Enciso, M; Sarasa, J; Romero, A; Fernández, M A; Gómez-Torres, M J

2017-10-01

Is permeable cryoprotectant-free vitrification of native sperm samples a good alternative to conventional slow freezing? The permeable cryoprotectant-free sperm vitrification protocol tested in this study renders considerably better recovery rates of good quality sperm compared to slow freezing. Slow freezing is currently the most commonly used technique for sperm cryopreservation, though this method has been repeatedly shown to have negative effects on both structural and functional sperm features. New alternative methods such as vitrification have been established as a successful alternative in other reproductive cell types, but vitrification of spermatozoa is still a rather unexplored methodology, with limited studies showing its efficacy in male gametes. This study included 18 normozoospermic sperm samples from patients seeking ART treatment between 2014 and 2015. The effects of a new vitrification protocol on functional and structural sperm quality parameters in comparison to fresh and slow-frozen samples were assessed. All samples were divided into three aliquots: fresh (F), slow freezing-thawing (S) and vitrification-warming (V). Sperm concentration, motility, morphology, vitality, DNA fragmentation, cytoskeleton integrity and spontaneous acrosome reaction were assessed and compared between the groups. Results showed improved preservation of sperm features after vitrification compared to conventional freezing. Permeable cryoprotectant-free vitrification presented a significantly higher percentage of live spermatozoa, than slow freezing, better preservation of acrosomes was achieved in vitrified samples and DNA fragmentation was reduced approximately one-third on average compared to slow freezing. Regarding tubulin assay, three different labelling patterns were observed. The frequency of these labelling patterns was similar in F and V groups but this was not the case of the S group. The multivariate analysis of all sperm quality parameters studied revealed

Bioenergetics of mammalian sperm capacitation.

Science.gov (United States)

Ferramosca, Alessandra; Zara, Vincenzo

2014-01-01

After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods.

A comparative CFD investigation of helical wire-wrapped 7, 19 and 37 fuel pin bundles and its extendibility to 217 pin bundle

International Nuclear Information System (INIS)

Gajapathy, R.; Velusamy, K.; Selvaraj, P.; Chellapandi, P.; Chetal, S.C.

2009-01-01

Preliminary investigations of sodium flow and temperature distributions in heat generating fuel pin bundles with helical spacer wires have been carried out. Towards this, the 3D conservation equations of mass, momentum and energy have been solved using a commercial computational fluid dynamics (CFD) code. Turbulence has been accounted through the use of high Reynolds number version of standard k-ε model, with uniform mesh density respecting wall function requirements. The geometric details of the bundle and the heat flux in are similar to that of the Indian Prototype Fast Breeder Reactor (PFBR) that is currently under construction. The mixing characteristics of the flow among the peripheral and central zones are compared for 7, 19 and 37 fuel pin bundles and the characteristics are extended to a 217 pin bundle. The friction factors of the pin bundles obtained from the present study is seen to agree well with the values derived from experimental correlations. It is found that the normalized outlet velocities in the peripheral and central zones are nearly equal to 1.1-0.9, respectively which is in good agreement with the published hydraulic experimental measurements of 1.1-0.85 for a 91 pin bundle. The axial velocity is the maximum in the peripheral zone where spacer wires are located and minimum in the zones which are diametrically opposite to the respective zone of maximum velocity. The sodium temperature is higher in the zones where the flow area and mass flow rates are less due to the presence of the spacer wires though the axial velocity is higher there. It is the minimum in the peripheral zones where the circumferential flow is larger. Based on the flow and temperature distributions obtained for 19 and 37 pin bundles, a preliminary extrapolation procedure has been established for estimating the temperatures of peripheral and central zones of 217 pin bundle.

Energy Homeostasis in Monotremes

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Stewart C. Nicol

2017-04-01

Full Text Available In 1803, the French anatomist Étienne Geoffroy Saint-Hilaire decided that the newly described echidna and platypus should be placed in a separate order, the monotremes, intermediate between reptiles and mammals. The first physiological observations showed monotremes had low body temperatures and metabolic rates, and the consensus was that they were at a stage of physiological development intermediate between “higher mammals” and “lower vertebrates.” Subsequent studies demonstrated that platypuses and echidnas are capable of close thermoregulation in the cold although less so under hot conditions. Because the short-beaked echidna Tachyglossus aculeatus, may show very large daily variations in body temperature, as well as seasonal hibernation, it has been suggested that it may provide a useful model of protoendotherm physiology. Such analysis is complicated by the very significant differences in thermal relations between echidnas from different climates. In all areas female echidnas regulate Tb within 1°C during egg incubation. The lactation period is considered to be the most energetically expensive time for most female mammals but lactating echidnas showed no measurable difference in field metabolic rate from non-lactating females, while the lactation period is more than 200 days for Kangaroo Island echidnas but only 150 days in Tasmania. In areas with mild winters echidnas show reduced activity and shallow torpor in autumn and early winter, but in areas with cold winters echidnas enter true hibernation with Tb falling as low as 4.5°C. Monotremes do not possess brown adipose tissue and maximum rates of rewarming from hibernation in echidnas were only half those of marmots of the same mass. Although echidnas show very large seasonal variations in fat stores associated with hibernation there is no relationship between plasma leptin and adiposity. Leptin levels are lowest during post-reproductive fattening, supporting suggestions that in

Decline of semen quality among Chinese sperm bank donors within 7 years (2008-2014

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Li Wang

2017-01-01

Full Text Available Semen from 5210 sperm bank donors was analyzed and trends in semen quality were evaluated at Shandong Human Sperm Bank between 2008 and 2014. After 2-7 days of abstinence, semen samples were collected. Measurements of semen volume, sperm concentration, sperm forward motility, and total sperm count were performed. There were significant declining trends in semen volume, sperm concentration, sperm forward motility, and total sperm count. Our results indicate that the quality of semen in this cohort of sperm donors had decreased during the study period.

Productivity of the supply system based on whole-tree bundling

Energy Technology Data Exchange (ETDEWEB)

Laitila, J. (Finnish Forest Research Inst., Joensuu (Finland)), Email: juha.laitila@metla.fi; Jylhae, P. (Finnish Forest Research Inst., Kannus (Finland)), Email: paula.jylha@metla.fi; Kaerhae, K. (Metsaeteho Oy, Helsinki (Finland)), Email: kalle.karha@metsateho.fi

2009-07-01

In the present study, time consumption models for bundle harvesting and forwarding were created by applying regression analyses. The time studies related to on-road transportation were created by applying regression analyses. The time studies related to on-road transportation were focused on comparing the terminal times spent on handling of whole-tree bundles and conventional 5-m pulpwood. The number of whole-tree bundles per truck load and the weights of the payloads were also recorded. The forwarding productivity of whole-tree bundles was about double compared to conventional pulpwood and whole-trees. In on-road transportation, the mean loading and unloading time of whole-tree bundles per truck load was 46 % higher compared to that of conventional 5-m pulpwood. The second prototype of the bundle harvester is under construction, and the time studies are to be continued after accomplishing the machine in the autumn 2009. (orig.)

Sperm dosage and site of insemination in relation to fertility in bovines

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Tushar Kumar Mohanty

2018-01-01

Full Text Available Low sperm numbers in artificial insemination (AI-doses are being used widely to make the best use of high genetic value bulls as well as sex-sorted semen. Sperm concentration needed for AI to obtain reasonable fertility, taking genetic value of bull and numerous others components into consideration is one of the essential constituents for successful AI breeding program. However, low sperm concentrations in AI-doses lead to reducing post-thaw viability. The reduction in viability of low sperm doses may be affected by fresh semen volume, sperm number and seminal plasma level at final dilution. Reduction in quality and fertility of low sperm doses is one of the limitations for their use in successful AI programme. Sperm number per AI required to achieve optimum fertility is one of the main crucial things to AI industry, and numerous efforts have been made in this regard. Due to great variability among bulls, sperm number per AI could be a limiting factor in achieving acceptable fertility values. Fertility of low sperm doses may vary among bulls, and non-return rates (NRRs with low sperm doses may be determined by fertility level of bull. On the basis of individual bulls, sperm numbers in AI doses needed to be adjusted to reduce the variations in NRRs among bulls. Utilizing high fertile bulls for low sperm doses with acceptable non-return rates (NRRs may be a way to cover a large number of bovines under AI in countries like India. Deposition site within the uterine horn may alter non return rates following inseminations with low sperm doses. Following deep-uterine inseminations, acceptable pregnancies may be achieved with low sperm doses and even if ovulation side is unknown.

Sperm morphological and morphometric evaluation in captive collared peccaries (Pecari tajacu

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Patrícia C. Sousa

2013-07-01

Full Text Available The aim of this study was to compare different staining methods for the evaluation of sperm morphology by light microscopy and also to describe the morphometry of the entire sperm in collared peccaries (Pecari tajacu. Semen from 10 males was obtained by electroejaculation and evaluated for sperm motility, vigor, and concentration. Semen smears were prepared through three different staining methods: Bengal rose, brome-phenol blue, and eosin-nigrosin. Smears were evaluated under light microscopy and sperm morphologic alterations were determined in percentage. In addition, sperm morphometric analysis was conducted by light microscopy coupled to image analyzer software. The smears stained with Bengal Rose provide the best results for the visualization of the sperm tail, midpiece, and head. The use of eosin-nigrosin stain did not allow an adequate impregnation, and some sperm presented a few contrasts with the background. A higher incidence of bent coiled tails was verified in the use of brome-phenol blue staining (P<0.05. Through morphometric evaluation, it was observed that the tail occupies the greatest proportion (89% of the sperm which presents a discretely elongated head. According to the results, the use of the Bengal Rose stain is recommended for the morphologic evaluation of the collared peccary sperm.

Sperm harvesting and cryopreservation during vasectomy reversal is not cost effective.

Science.gov (United States)

Boyle, Karen E; Thomas, Anthony J; Marmar, Joel L; Hirshberg, Steven; Belker, Arnold M; Jarow, Jonathan P

2006-04-01

To determine whether sperm harvesting and cryopreservation at the time of vasectomy reversal is cost-effective. Model of actual costs and results at five institutions. Multicenter study comprising five centers, including university hospitals and private practices. Men undergoing vasectomy reversal. We established two models for vasectomy reversal. The first model was sperm harvesting and cryopreservation at the time of vasectomy reversal. The second model was sperm harvesting at the time of IVF only if the patient remained azoospermic after vasectomy reversal. Vasectomy reversal procedures modeled included bilateral vasovasostomy and bilateral epididymovasostomy. The costs for each procedure at the five institutions were collated and median costs determined. Median cost of procedure and calculated financial comparisons. The median cost of testicular sperm extraction/cryopreservation performed at the time of bilateral vasovasostomy was $1,765 (range, $1,025-$2,800). The median cost of microsurgical epididymal sperm aspiration or testicular sperm extraction with cryopreservation performed at the time of epididymovasostomy was $1,209 (range, $905-$2,488). The average of the median costs for percutaneous sperm aspiration or testicular sperm aspiration for those patients with a failed vasectomy reversal was $725 (range, $400-$1,455). Sperm retrieval with cryopreservation at the time of vasectomy reversal is not a cost-effective management strategy.

Body mass index effects sperm quality: a retrospective study in Northern China

Directory of Open Access Journals (Sweden)

En-Yin Wang

2017-01-01

Full Text Available Excess weight and obesity have become a serious problem in adult men of reproductive age throughout the world. The purpose of this retrospective study was to assess the relationships between body mass index and sperm quality in subfertile couples in a Chinese Han population. Sperm analyses were performed and demographic data collected from 2384 male partners in subfertile couples who visited a reproductive medical center for treatment and preconception counseling. The subjects were classified into four groups according to their body mass index: underweight, normal, overweight, and obese. Of these subjects, 918 (38.3% had a body mass index of >25.0 kg m−0 2 . No significant differences were found between the four groups with respect to age, occupation, level of education, smoking status, alcohol use, duration of sexual abstinence, or the collection time of year for sperm. The results clearly indicated lower sperm quality (total sperm count, sperm concentration, motile sperm, relative amounts of type A motility, and progressive motility sperm [A + B] in overweight and obese participants than in those with normal body mass index. Normal sperm morphology and sperm volume showed no clear difference between the four groups. This study indicates that body mass index has a negative effect on sperm quality in men of subfertile couples in a Northern Chinese population. Further study should be performed to investigate the relationship between body mass index and sperm quality in a larger population.

Computer-assisted sperm analysis (CASA): capabilities and potential developments.

Science.gov (United States)

Amann, Rupert P; Waberski, Dagmar

2014-01-01

Computer-assisted sperm analysis (CASA) systems have evolved over approximately 40 years, through advances in devices to capture the image from a microscope, huge increases in computational power concurrent with amazing reduction in size of computers, new computer languages, and updated/expanded software algorithms. Remarkably, basic concepts for identifying sperm and their motion patterns are little changed. Older and slower systems remain in use. Most major spermatology laboratories and semen processing facilities have a CASA system, but the extent of reliance thereon ranges widely. This review describes capabilities and limitations of present CASA technology used with boar, bull, and stallion sperm, followed by possible future developments. Each marketed system is different. Modern CASA systems can automatically view multiple fields in a shallow specimen chamber to capture strobe-like images of 500 to >2000 sperm, at 50 or 60 frames per second, in clear or complex extenders, and in information for ≥ 30 frames and provide summary data for each spermatozoon and the population. A few systems evaluate sperm morphology concurrent with motion. CASA cannot accurately predict 'fertility' that will be obtained with a semen sample or subject. However, when carefully validated, current CASA systems provide information important for quality assurance of semen planned for marketing, and for the understanding of the diversity of sperm responses to changes in the microenvironment in research. The four take-home messages from this review are: (1) animal species, extender or medium, specimen chamber, intensity of illumination, imaging hardware and software, instrument settings, technician, etc., all affect accuracy and precision of output values; (2) semen production facilities probably do not need a substantially different CASA system whereas biology laboratories would benefit from systems capable of imaging and tracking sperm in deep chambers for a flexible period of time

Quantitative evaluation of radiation-induced changes in sperm morphology and chromatin distribution

International Nuclear Information System (INIS)

Aubele, M.; Burger, G.; Gais, P.; Juetting, V.; Rodenacker, K.; Hacker-Klom, V.

1993-01-01

Sperm head cytometry provides a useful assay for the detection of radiation induced damage in mouse germ cells. Exposure of the gonads to radiation is long known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm were performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show bigger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to discriminate sperm 35 dpr. This may be explained by differentiation processes, which take place in different stages during mouse spermatogenesis. (authors). 25 refs., 4 tabs., 7 figs

Carbonic anhydrases and their functional differences in human and mouse sperm physiology.

Science.gov (United States)

José, O; Torres-Rodríguez, P; Forero-Quintero, L S; Chávez, J C; De la Vega-Beltrán, J L; Carta, F; Supuran, C T; Deitmer, J W; Treviño, C L

2015-12-25

Fertilization is a key reproductive event in which sperm and egg fuse to generate a new individual. Proper regulation of certain parameters (such as intracellular pH) is crucial for this process. Carbonic anhydrases (CAs) are among the molecular entities that control intracellular pH dynamics in most cells. Unfortunately, little is known about the function of CAs in mammalian sperm physiology. For this reason, we re-explored the expression of CAI, II, IV and XIII in human and mouse sperm. We also measured the level of CA activity, determined by mass spectrometry, and found that it is similar in non-capacitated and capacitated mouse sperm. Importantly, we found that CAII activity accounts for half of the total CA activity in capacitated mouse sperm. Using the general CA inhibitor ethoxyzolamide, we studied how CAs participate in fundamental sperm physiological processes such as motility and acrosome reaction in both species. We found that capacitated human sperm depend strongly on CA activity to support normal motility, while capacitated mouse sperm do not. Finally, we found that CA inhibition increases the acrosome reaction in capacitated human sperm, but not in capacitated mouse sperm. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantitative evaluation of radiation-induced changes in sperm morphology and chromatin distribution

Energy Technology Data Exchange (ETDEWEB)

Aubele, M; Burger, G; Gais, P; Juetting, V; Rodenacker, K [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany); Hacker-Klom, V [Muenster Univ. (Germany). Inst. fuer Strahlenbiologie

1994-12-31

Sperm head cytometry provides a useful assay for the detection of radiation induced damage in mouse germ cells. Exposure of the gonads to radiation is long known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm were performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show bigger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to discriminate sperm 35 dpr. This may be explained by differentiation processes, which take place in different stages during mouse spermatogenesis. (authors). 25 refs., 4 tabs., 7 figs.

Kernel bundle EPDiff

DEFF Research Database (Denmark)

Sommer, Stefan Horst; Lauze, Francois Bernard; Nielsen, Mads

2011-01-01

In the LDDMM framework, optimal warps for image registration are found as end-points of critical paths for an energy functional, and the EPDiff equations describe the evolution along such paths. The Large Deformation Diffeomorphic Kernel Bundle Mapping (LDDKBM) extension of LDDMM allows scale space...

Interplanetary Overlay Network Bundle Protocol Implementation

Science.gov (United States)

Burleigh, Scott C.

2011-01-01

The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

Male crickets adjust ejaculate quality with both risk and intensity of sperm competition.

Science.gov (United States)

Simmons, Leigh W; Denholm, Amy; Jackson, Chantelle; Levy, Esther; Madon, Ewa

2007-10-22

Sperm competition theory predicts that males should increase their expenditure on the ejaculate with increasing risk of sperm competition, but decrease their expenditure with increasing intensity. There is accumulating evidence for sperm competition theory, based on examinations of testes size and/or the numbers of sperm ejaculated. However, recent studies suggest that ejaculate quality can also be subject to selection by sperm competition. We used experimental manipulations of the risk and intensity of sperm competition in the cricket, Teleogryllus oceanicus. We found that males produced ejaculates with a greater percentage of live sperm when they had encountered a rival male prior to mating. However, when mating with a female that presented a high intensity of sperm competition, males did not respond to risk, but produced ejaculates with a reduced percentage of live sperm. Our data suggest that males exhibit a fine-tuned hierarchy of responses to these cues of sperm competition.

Drosophila melanogaster seminal fluid can protect the sperm of other males

DEFF Research Database (Denmark)

Holman, Luke

2009-01-01

a different male. This study therefore provides strong evidence that seminal fluid does not kill rival sperm, and instead can actually protect them. This study also tested whether chemicals in the female reproductive tract harm sperm as in another Drosophila species, but found no evidence of this. # 3...... physiology. # 2. Seminal fluid is well-studied in Drosophila melanogaster, a species in which it has been suggested to 'incapacitate' the sperm of rival males (e.g. by killing them) and thereby provide an advantage in sperm competition. This hypothesis has been tested several times over many years......, but different studies have yielded conflicting conclusions. Here, I use fluorescent staining to directly measure the effects of D. melanogaster seminal fluid on the survival of sperm from the same male or from a rival. The results suggest that seminal fluid improves sperm survival, even if the sperm are from...

Superconductivity in an Inhomogeneous Bundle of Metallic and Semiconducting Nanotubes

Directory of Open Access Journals (Sweden)

Ilya Grigorenko

2013-01-01

Full Text Available Using Bogoliubov-de Gennes formalism for inhomogeneous systems, we have studied superconducting properties of a bundle of packed carbon nanotubes, making a triangular lattice in the bundle's transverse cross-section. The bundle consists of a mixture of metallic and doped semiconducting nanotubes, which have different critical transition temperatures. We investigate how a spatially averaged superconducting order parameter and the critical transition temperature depend on the fraction of the doped semiconducting carbon nanotubes in the bundle. Our simulations suggest that the superconductivity in the bundle will be suppressed when the fraction of the doped semiconducting carbon nanotubes will be less than 0.5, which is the percolation threshold for a two-dimensional triangular lattice.

Two-categorical bundles and their classifying spaces

DEFF Research Database (Denmark)

Baas, Nils A.; Bökstedt, M.; Kro, T.A.

2012-01-01

-category is a classifying space for the associated principal 2-bundles. In the process of proving this we develop a lot of powerful machinery which may be useful in further studies of 2-categorical topology. As a corollary we get a new proof of the classification of principal bundles. A calculation based...

CFD modeling of secondary flows in fuel rod bundles

International Nuclear Information System (INIS)

Baglietto, Emilio; Ninokata, Hisashi

2004-01-01

An optimized non-linear eddy viscosity model is introduced, for calculations of detailed coolant velocity distribution in a tight lattice fuel bundle. The low Reynolds formulation has been optimized based on DNS data for channel flow. The non-linear stress-strain relationship has been modified in the coefficients to model the flow anisotropy, which causes the formation of turbulence driven secondary flows inside the bundle subchannels. Predictions of the model are first compared to experimental measurements of secondary flows in a triangularly arrayed rod bundle with p/d=1.3. Subsequently wall shear stress and velocity predictions are compared with different experimental data for a rod bundle with p/d=1.17. The model shows to be able to correctly reproduce the scale of the secondary motion, and to accurately reproduce both wall shear stress and velocity distributions inside the rod bundle subchannels. (author)

The zinc transporter ZIPT-7.1 regulates sperm activation in nematodes.

Directory of Open Access Journals (Sweden)

Yanmei Zhao

2018-06-01

Full Text Available Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding to activating signals. The zipt-7.1 gene is expressed in the germ line and functions in germ cells to promote sperm activation. When expressed in mammalian cells, ZIPT-7.1 mediates zinc transport with high specificity and is predominantly located on internal membranes. Finally, genetic epistasis places zipt-7.1 at the end of the spe-8 sperm activation pathway, and ZIPT-7.1 binds SPE-4, a presenilin that regulates sperm activation. Based on these results, we propose a new model for sperm activation. In spermatids, inactive ZIPT-7.1 is localized to the membranous organelles, which contain higher levels of zinc than the cytoplasm. When sperm activation is triggered, ZIPT-7.1 activity increases, releasing zinc from internal stores. The resulting increase in cytoplasmic zinc promotes the phenotypic changes characteristic of activation. Thus, zinc signaling is a key step in the signal transduction process that mediates sperm activation, and we have identified a zinc transporter that is central to this activation process.

Gulf of Mexico sperm whale photo-ID catalog

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Photo-identification data on sperm whales occupying the north central Gulf of Mexico have been collected during vessel surveys. Photographs of sperm whales are taken...

Sperm freezing to address the risk of azoospermia on the day of ICSI.

Science.gov (United States)

Montagut, M; Gatimel, N; Bourdet-Loubère, S; Daudin, M; Bujan, L; Mieusset, R; Isus, F; Parinaud, J; Leandri, R

2015-11-01

In which cases is freezing of ejaculated sperm indicated before ICSI? Sperm freezing should be performed only when out of two analyses at least one total sperm count in the ejaculate is lower than 10(6). Due to variations in individual sperm parameters, in cases of severe oligozoospermia there is a risk of absence of spermatozoa on the day of ICSI, leading to cancellation of the attempt. Sperm freezing can avoid this problem but little is known of the parameters governing the decision to freeze sperm or not. This retrospective study included 247 men who underwent sperm cryopreservation to prevent the risk of azoospermia on the day of ICSI, from 2000 to 2012. Receiver operating characteristic curve analysis was used to define the threshold value. The lowest total sperm count per ejaculate was studied as a predictive factor for the use of frozen sperm in a total of 593 ICSI attempts. Moreover, 2003 patients who had at least 4 semen analyses for andrological diagnosis have been studied to evaluate the reproducibility of sperm count. To evaluate the psychological impact of sperm freezing, a questionnaire was administered to 84 men who attended for sperm cryopreservation between June and December 2014. The cost of sperm freezing was analysed according to the French prices. When at least one total sperm count was counts were ≥10(5) (P sperm freezing is recommended when one analysis from at least two, showed a sperm count sperm freezings. The psychological impact of sperm freezing was good since >70% of men had positive feelings about this technique. This was a fairly short-term study and preservation of future fertility was not assessed. It appeared impossible to find a threshold that would predict the risk of azoospermia with 100% accuracy. Therefore there is still a risk of absence of spermatozoa on the day of ICSI despite a good negative predictive value when no total sperm count was lower than 10(5). These data suggest that sperm freezing should be proposed when

Analysis of the impact of cryopreservation and theophylline on motility of sperm

Directory of Open Access Journals (Sweden)

Elaheh Gorji

2018-06-01

Full Text Available Objective: Sperm parameters, particularly motility, decrease during cryopreservation. Theophylline generally enhances sperm motility. We analyzed effects of theophylline and freezing on sperm motility.Design: Experimental study.Setting: Private IVF lab.Setting: IVF lab of Mehrgan Hospital. Method: 22–55 year-old men participated in this study (30 fresh ejaculation and 8 TESE samples. After sperm analysis, we added theophylline (40 mM to half of our samples as case group to compare motility with the remaining samples as control group. Cryopreservation was performed in two groups. After thawing, motility of both groups was recorded. Furthermore, theophylline (40 mM was applied to both groups after thawing again. Result: After adding theophylline, sperm motility improved significantly in all samples. Sperm motility reduced in control group more than the study group after freeze-thaw procedure (P < 0.002, normal morphology <5%. Sperm motility was not enhanced significantly by re-adding of theophylline to the two groups. Interactions between stages and groups were statistically significant in semen and biopsy samples (p < 0.001. Conclusion: Adding theophylline before freezing can preserve motility of sperms in samples with different parameters and even sperms extracted in testicular biopsy. Theophylline may have protective impact on sperms in freezing procedure. Keywords: Sperm motility, Theophylline, Freezing, Morphology, Biopsy

Frobenius splitting of projective toric bundles

Indian Academy of Sciences (India)

He Xin

2018-03-19

Mar 19, 2018 ... Firstly it is easy to see that the image of s under the restriction map (2.5) falls in the χ-isotypical component of (Uσ , E), i.e. for all t ∈ T .... σ falls in the χ-isotypical component of (E,Uσ ). D. As mentioned in Remark 2.3, for a vector v .... The determinant of a toric bundle. LetE be a toric bundle on a toric variety X ...

Anti sperm antibodies detection in infertile patients by radioimmunometry

International Nuclear Information System (INIS)

ELnabarawy, F.; Megahed, Y.M.; Tadrous, G.A.; Hamada, T.; Elbadry, A.

1992-01-01

Three different methods of testing for anti sperm antibodies were compared: complement cytotoxicity, sperm agglutination, and radiolabelled anti globulin antibody technique, for detection of anti sperm antibodies in serum and secretions (seminal plasma and cervical mucus). Sample from 120 patients with infertility were investigated by the previous three methods. The results of unexplained infertile patients revealed wide variations in figures, concerning the positivity of anti sperm antibody whether in their serum or secretions, by using the cytotoxicity or sperm agglutination tests. Using a specific radiolabelled anti globulin test, a subset of patients (44.9% in the serum of men and 50% in seminal plasma) with IgG anti sperm antibody was identified, and this antibody was present in 65.4% and 78,6% of infertile wives sera and cervical mucus, respectively. Therefore, this test has been used to identify and quantitate antibodies directed toward other human cell surfaces. It was concluded that this radiolabelled method is a clinically useful and a potentially versatile procedure that can be successfully applied to the diagnosis and management of patients with suspected immunologic infertility. 1 fig., 5 tab

Application of Sperm Selection Using Hyaluronic Acid Binding in Intracytoplasmic Sperm Injection Cycles: A Sibling Oocyte Study

Science.gov (United States)

Choe, Seung Ah; Tae, Jin Chul; Shin, Mi Young; Kim, Hyun Jung; Kim, Chung Hyon; Lee, Joong Yeup; Hwang, Doyeong; Kim, Ki Chul; Suh, Chang Suk

2012-01-01

The purpose of this study was to investigate whether sperm selection by hyaluronic acid (HA) binding could improve fertilization rate and embryo quality in intracytoplasmic sperm injection (ICSI) cycles. Two hundred nineteen oocytes obtained from eighteen women were injected with either HA-bound (n = 107) or conventionally selected spermatozoa (n = 112) in a randomized way. All of the participants were infertile couples who had normal sperm parameters but low fertilization rate in previous in vitro fertilization (IVF) cycle (n = 5) or experienced multiple IVF failures (n = 13). Lower fertilization (75.7% vs 83.0%) and cleavage rate on day 2 (72.9% vs 83.0%) was observed in oocytes injected with HA-bound spermatozoa than the conventional group, but the difference was not significant. Significantly lower cleavage rate was observed on day 3 in HA group (56.0% vs 69.6%, P = 0.038). Blastocyst formation rate and the number of transferred embryos were similar in both groups. In multiple IVF failure patients, significantly reduced fertilization rate (71.8% vs 85.3%, P = 0.046) and cleavage rate on day 2 (70.4% vs 85.3%, P = 0.029) and day 3 (53.5% vs 77.3%, P = 0.002) were noticed in HA group. Five women achieved pregnancy continuing more than 12 weeks after transfer (27.8%). Success of ICSI was not related with the number of embryos fertilized by HA-bound spermatozoa. Application of ICSI by sperm selection using HA binding is not helpful in couples with repeated poor fertilization or implantation despite normal sperm parameters. PMID:23255860

Linear models for assessing mechanisms of sperm competition: the trouble with transformations.

Science.gov (United States)

Eggert, Anne-Katrin; Reinhardt, Klaus; Sakaluk, Scott K

2003-01-01

Although sperm competition is a pervasive selective force shaping the reproductive tactics of males, the mechanisms underlying different patterns of sperm precedence remain obscure. Parker et al. (1990) developed a series of linear models designed to identify two of the more basic mechanisms: sperm lotteries and sperm displacement; the models can be tested experimentally by manipulating the relative numbers of sperm transferred by rival males and determining the paternity of offspring. Here we show that tests of the model derived for sperm lotteries can result in misleading inferences about the underlying mechanism of sperm precedence because the required inverse transformations may lead to a violation of fundamental assumptions of linear regression. We show that this problem can be remedied by reformulating the model using the actual numbers of offspring sired by each male, and log-transforming both sides of the resultant equation. Reassessment of data from a previous study (Sakaluk and Eggert 1996) using the corrected version of the model revealed that we should not have excluded a simple sperm lottery as a possible mechanism of sperm competition in decorated crickets, Gryllodes sigillatus.

THE SIGNIFICANCE OF ANTISPERM ANTIBODIES FOR SPERM - CERVICAL-MUCUS INTERACTION

NARCIS (Netherlands)

KREMER, J; JAGER, S

An overview is presented of the effects of antisperm antibodies on the sperm - cervical mucus interaction. Antisperm IgA on spermatozoa or in cervical mucus can severely inhibit sperm penetration of cervical mucus and migration through it. Disturbance of the sperm - cervical mucus interaction is the

Analytical prediction of turbulent friction factor for a rod bundle

International Nuclear Information System (INIS)

Bae, Jun Ho; Park, Joo Hwan

2011-01-01

An analytical calculation has been performed to predict the turbulent friction factor in a rod bundle. For each subchannel constituting a rod bundle, the geometry parameters are analytically derived by integrating the law of the wall over each subchannel with the consideration of a local shear stress distribution. The correlation equations for a local shear stress distribution are supplied from a numerical simulation for each subchannel. The explicit effect of a subchannel shape on the geometry parameter and the friction factor is reported. The friction factor of a corner subchannel converges to a constant value, while the friction factor of a central subchannel steadily increases with a rod distance ratio. The analysis for a rod bundle shows that the friction factor of a rod bundle is largely affected by the characteristics of each subchannel constituting a rod bundle. The present analytic calculations well predict the experimental results from the literature with rod bundles in circular, hexagonal, and square channels.

Matrix remodeling between cells and cellular interactions with collagen bundle

Science.gov (United States)

Kim, Jihan; Sun, Bo

When cells are surrounded by complex environment, they continuously probe and interact with it by applying cellular traction forces. As cells apply traction forces, they can sense rigidity of their local environment and remodel the matrix microstructure simultaneously. Previous study shows that single human carcinoma cell (MDA-MB-231) remodeled its surrounding extracellular matrix (ECM) and the matrix remodeling was reversible. In this study we examined the matrix microstructure between cells and cellular interaction between them using quantitative confocal microscopy. The result shows that the matrix microstructure is the most significantly remodeled between cells consisting of aligned, and densified collagen fibers (collagen bundle)., the result shows that collagen bundle is irreversible and significantly change micromechanics of ECM around the bundle. We further examined cellular interaction with collagen bundle by analyzing dynamics of actin and talin formation along with the direction of bundle. Lastly, we analyzed dynamics of cellular protrusion and migrating direction of cells along the bundle.

Large bundle BWR test CORA-18: Test results

International Nuclear Information System (INIS)

Hagen, S.; Hofmann, P.; Noack, V.; Sepold, L.; Schanz, G.; Schumacher, G.

1998-04-01

The CORA out-of-pile experiments are part of the international Severe Fuel Damage (SFD) Program. They were performed to provide information on the damage progression of Light Water Reactor (LWR) fuel elements in Loss-of-coolant Accidents in the temperature range 1200 C to 2400 C. CORA-18 was the large BWR bundle test corresponding to the PWR test CORA-7. It should investigate if there exists an influence of the BWR bundle size on the fuel damage behaviour. Therefore, the standard-type BWR CORA bundle with 18 fuel rod simulators was replaced by a large bundle with two additional surrounding rows of 30 rods (48 rods total). Power input and steam flow were increased proportionally to the number of fuel rod simulators to give the same initial heat-up rate of about 1 K/s as in the smaller bundles. Emphasis was put on the initial phase of the damage progression. More information on the chemical composition of initial and intermediate interaction products and their relocation behaviour should be obtained. Therefore, power and steam input were terminated after the onset of the temperature escalation. (orig.) [de

A Systematic Analysis of a Deep Mouse Epididymal Sperm Proteome

Energy Technology Data Exchange (ETDEWEB)

Chauvin, Theodore; Xie, Fang; Liu, Tao; Nicora, Carrie D.; Yang, Feng; Camp, David G.; Smith, Richard D.; Roberts, Kenneth P.

2012-12-21

Spermatozoa are highly specialized cells that, when mature, are capable of navigating the female reproductive tract and fertilizing an oocyte. The sperm cell is thought to be largely quiescent in terms of transcriptional and translational activity. As a result, once it has left the male reproductive tract, the sperm cell is essentially operating with a static population of proteins. It is therefore theoretically possible to understand the protein networks contained in a sperm cell and to deduce its cellular function capabilities. To this end we have performed a proteomic analysis of mouse sperm isolated from the cauda epididymis and have confidently identified 2,850 proteins, which is the most comprehensive sperm proteome for any species reported to date. These proteins comprise many complete cellular pathways, including those for energy production via glycolysis, β-oxidation and oxidative phosphorylation, protein folding and transport, and cell signaling systems. This proteome should prove a useful tool for assembly and testing of protein networks important for sperm function.

Surgical anatomy of the atrioventricular conduction bundle in anomalous muscle bundle of the right ventricle with subarterial ventricular septal defect

NARCIS (Netherlands)

Kurosawa, H.; Becker, A. E.

1985-01-01

A stillborn baby girl was found to have an anomalous muscle bundle of the right ventricle, associated with a doubly committed subarterial ventricular septal defect. The latter was separated from the area of the atrioventricular conduction bundle by muscle. Serial histologic sectioning of the

Broadband and flexible acoustic focusing by metafiber bundles

Science.gov (United States)

Sun, Hong-Xiang; Chen, Jia-He; Ge, Yong; Yuan, Shou-Qi; Liu, Xiao-Jun

2018-06-01

We report a broadband and flexible acoustic focusing through metafiber bundles in air, in which each metafiber consists of eight circular and narrow rectangular cavities. The fractional bandwidth of the acoustic focusing could reach about 0.2, which arises from the eigenmodes of the metafiber structure. Besides, owing to the flexible characteristic of the metafibers, the focus position can be manipulated by bending the metafiber bundles, and the metafiber bundles could bypass rigid scatterers inside the lens structure. More interestingly, the acoustic propagation and focusing directions can be changed by using a designed right-angled direction converter fabricated by the metafibers, and a waveform converter and a focusing lens of the cylindrical acoustic source are realized based on the metafiber bundles. The proposed focusing lens has the advantages of broad bandwidth, flexible structure, and high focusing performance, showing great potentials in versatile applications.

Evidence for nuclear internalization of exogenous DNA into mammalian sperm cells

International Nuclear Information System (INIS)

Francolini, M.; Lavitrano, M.; Lamia, C.L.; French, D.; Frati, L.; Cotelli, F.; Spadafora, C.

1993-01-01

Mature sperm cells have the spontaneous capacity to take up exogenous DNA. Such DNA specifically interacts with the subacrosomal segment of the sperm head corresponding to the nuclear area. Part of the sperm-bound foreign DNA is further internalized into nuclei. Using end-labelled plasmid DNA we have found that 15-22% of the total sperm bound DNA is associated with nuclei as determined on isolated nuclei. On the basis of autoradiographic analysis, nuclear permeability to exogenous DNA seems to be a wide phenomenon involving the majority of the sperm nuclei. In fact, the foreign DNA, incubated with sperm cells for different lengths of time, is found in 45% (10 min) to 65% (2 hr) of the sperm nuclei. Ultrastructural autoradiography on thin sections of mammalian spermatozoa, preincubated with end-labelled plasmid DNA, shows that the exogenous DNA is internalized into the nucleus. This conclusion is further supported by ultrastructural autoradiographic analysis on thin sections of nuclei isolated from spermatozoa preincubated with end-labelled DNA

Sperm traits differ between winged and wingless males of the ant Cardiocondyla obscurior.

Science.gov (United States)

Schrempf, Alexandra; Moser, Astrid; Delabie, Jacques; Heinze, Jürgen

2016-11-01

Size and shape of sperm cells vary tremendously throughout the animal kingdom. The adaptive significance of this variation is not fully understood. In addition to sperm-female interactions and the environmental conditions, the risk of sperm competition might affect number, morphology and other "quality" traits of sperm. In the male-diphenic ant Cardiocondyla obscurior, winged sneaker males have limited sperm number, because their testes degenerate shortly after adult emergence, as is typical for males of social Hymenoptera. In contrast, wingless fighter males continuously replenish their sperm supply due to their exceptional lifelong spermatogenesis. While winged males usually have to compete with several other winged males for virgin queens, wingless males are able to monopolize queens by killing all other rivals. Hence, this presents a unique system to investigate how alternative reproductive tactics and associated physiology affect sperm morphology and viability. We found that sperm-limited males invest into sperm number instead of sperm size. Variance in sperm length is smaller in winged males, probably reflecting that they have to compete with several other males. Finally, sperm viability is equally high in both male phenotypes. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Sperm Donation and the Right to Privacy.

Science.gov (United States)

Hallich, Oliver

2017-07-01

Sperm donation is an increasingly common method of assisted reproduction. In the debate on sperm donation, the right to privacy - construed as a right that refers to the limits of the realm of information to which others have access - plays a pivotal role with regard to two questions. The first question is whether the sperm donor's right to privacy implies his right to retain his anonymity, the second is whether the gamete recipients' right to privacy entitles them to withhold information about the circumstances of their conception from their donor-conceived offspring. In this contribution, I tackle these two interrelated questions. In part (1), I defend the view that there is a prima facie right of sperm donors to remain anonymous. Part (2) widens the perspective by taking into consideration the welfare of donor-conceived offspring. I argue that anonymity may harm the child only if the gametes' recipients decide to disclose information about the circumstances of her birth to the child. Non-disclosure of these circumstances, however, is morally problematic because it may not necessarily harm, but wrong the child. In section (3), I attempt to rebut some arguments in defense of non-disclosure. In part (4), I defend the view that the best practice of sperm donation would be 'direct donation', i.e. that the identity of the donor is known from the time of conception. Part (5) concludes.

Abundance and Distribution of Sperm Whales in the Canary Islands: Can Sperm Whales in the Archipelago Sustain the Current Level of Ship-Strike Mortalities?

Science.gov (United States)

Fais, Andrea; Lewis, Tim P.; Zitterbart, Daniel P.; Álvarez, Omar; Tejedor, Ana; Aguilar Soto, Natacha

2016-01-01

Sperm whales are present in the Canary Islands year-round, suggesting that the archipelago is an important area for this species in the North Atlantic. However, the area experiences one of the highest reported rates of sperm whale ship-strike in the world. Here we investigate if the number of sperm whales found in the archipelago can sustain the current rate of ship-strike mortality. The results of this study may also have implications for offshore areas where concentrations of sperm whales may coincide with high densities of ship traffic, but where ship-strikes may be undocumented. The absolute abundance of sperm whales in an area of 52933 km2, covering the territorial waters of the Canary Islands, was estimated from 2668 km of acoustic line-transect survey using Distance sampling analysis. Data on sperm whale diving and acoustic behaviour, obtained from bio-logging, were used to calculate g(0) = 0.92, this is less than one because of occasional extended periods when whales do not echolocate. This resulted in an absolute abundance estimate of 224 sperm whales (95% log-normal CI 120–418) within the survey area. The recruitment capability of this number of whales, some 2.5 whales per year, is likely to be exceeded by the current ship-strike mortality rate. Furthermore, we found areas of higher whale density within the archipelago, many coincident with those previously described, suggesting that these are important habitats for females and immature animals inhabiting the archipelago. Some of these areas are crossed by active shipping lanes increasing the risk of ship-strikes. Given the philopatry in female sperm whales, replacement of impacted whales might be limited. Therefore, the application of mitigation measures to reduce the ship-strike mortality rate seems essential for the conservation of sperm whales in the Canary Islands. PMID:26999791