Impaired spermatogenesis in Finnish boars and bulls

Maintenance of breeding efficiency and high semen quality is essential for reproductive success in farm animals. Early recognition of possible inheritable factors causing infertility requires constant attention. This thesis focuses on describing different manifestations of impaired spermatogenesis, their impact on fertility and partly also their incidence in populations. The reasons for spermatogenic failure are various. An interruption of germ cell differentiation, spermatogenic arrest, can lead to infertility. The incidence of azoospermia was investigated in the 1996 2005 survey of Finnish AI and farm breeding boars. We focused on the diagnosis, testicular morphometry and the possible reasons for the condition. The incidence of azoospermia was significantly higher in Yorkshire boars than in the Landrace breed. The most common diagnosis in Yorkshire boars was germ cell arrest at the primary spermatocyte level. The second most frequent diagnosis in Yorkshire boars was segmental aplasia of the Wolffian ducts with idiopathic epididymal obstruction. Other reasons for azoospermia were infrequent. In the second study we investigated the incidence of two relatively well-defined specific sperm defects in Finnish Yorkshire and Landrace boars during the same survey, the immotile short-tail sperm (ISTS) defect and the knobbed acrosome (KA) defect. In the Finnish Yorkshire boars the inherited ISTS defect, and the probably inherited KA defect, were important causes of infertility during 1996 2005. The ISTS defect was found in 7.6% and the KA defect in 0.8% of the Yorkshire boars. No Landrace boars were diagnosed with either of these two defects. In the third study we described a new sterilizing sperm defect in an oligoasthenoterazoospermic bull. Because of its morphological characteristics this defect was termed the multinuclear-multiflagellar sperm (MNMFS) defect. The number of Sertoli cells in the seminiferous tubuli was highly increased in the MNMFS bull compared with the number in normal bulls. In the following two studies we used a combined approach of fluorescence in situ hybridization (FISH), flow cytometry and morphometric studies to provide information on the cytogenetic background of macrocephalic bull spermatozoa. We described cellular features of diploid spermatozoa and compared the failures in the first and second meiotic divisions. In the last study we describe how the transplantation of testicular cells was used to determine whether spermatogonia derived from donor animals are able to colonize and produce motile spermatozoa in immune-competent unrelated boars suffering the ISTS defect. Transplantation resulted in complete focal spermatogenesis, indicated by the appearance of motile spermatozoa and confirmed by genotyping.

Laboratory studies on ball wear in the grinding of a hematite-magnetite ore

Marked-ball grinding tests were carried out under different grinding conditions and environments. Three types of balls were used, namely, cast hyper steel, high chrome cast iron and EN-31 (forged), which cover a wide range of chemical composition, microstructure and media hardness. The effect of pulp density on ball wear and grinding efficiency was also studied. Relative pulp viscosities at different percent solids for the ore slurry were also determined. As the Kudremukh ore contained about 0.2% pyrite, the effect of addition of pyrite on ball wear was studied separately. Results of marked-ball grinding tests indicated that ball wear increased with time and showed a sharp increase for wet grinding over dry grinding. Ball wear under wet grinding conditions was also influenced by the gaseous atmosphere in the mill. At 70% solids, the best results in terms of reduced ball wear coupled with satisfactory grinding efficiency were obtained. The influence of oxygen on the corrosive wear of grinding balls was increasingly felt only if sulphide minerals such as pyrite were also present in the ore. The various ball materials could be arranged in the following order with respect to their overall wear resistance: high chrome cast iron > EN-31 (forged) > cast hyper steel.Possible ball wear mechanisms involved in the grinding of Kudremukh ore are discussed.

Ball wear and its control in the grinding of a lead-zinc sulphide ore

Marked ball grinding tests were carried out in the laboratory with a lead-zinc sulphide ore under different experimental conditions using high carbon low alloy steel (cast and forged) and high chrome cast iron balls. Relative ball wear as a function of grinding period and milling conditions was evaluated for the different types of ball materials. The role of corrosion and abrasion-erosion in the wear of grinding media is brought out. Methods to minimise ball wear through control of mill atmosphere and addition of reagents are discussed.

Bioleaching of sulphides under applied potentials

The influence of applied DC potentials on the activity and growth of Thiobacillus ferrooxidans, as well as on the dissolution behaviour of some base metal sulphides is discussed with reference to bioleaching. Selective bioleaching of zinc from sphalerite could be achieved under an applied potential of −500 mV (saturated calomel electrode) from binary mineral mixtures containing the zinc mineral and chalcopyrite or pyrite. On the other hand, bioleaching of pyrite and chalcopyrite was found to be enhanced under positive potentials of +400 mV and +600 mV, respectively. Probable mechanisms in the electrobioleaching of sulphides are examined with respect to galvanic, microbiological and applied potential effects.

Inkluderande teaterverksamhet. Nya möjligheter för socialt arbete

I denna pro gradu-avhandling granskas teaterns möjligheter att främja social inklusion. Genom att analysera vad drama och teater kan ge ungdomar och hur social inklusion bland unga i ett samfund kan främjas, belyses även frågan om hur socialt arbete och teater ömsesidigt kan berika varandra. Avhandlingen är en fallstudie av Half Moon Young People’s Theatre, en barn- och ungdomsteater i Tower Hamlets i östra London. Teatern arbetar med barn och unga med ett särskilt fokus på att engagera grupper som ofta marginaliserats, exempelvis på grund av sin kulturella bakgrund eller till följd av funktionshinder. I denna studie är fokus på Half Moons projekt riktade till tonåringar: Careers in Theatre, Speak Up och ungdomsteatergrupperna Lunar och Solar. Studien är kvalitativ och studiens empiriska data har främst samlats in genom deltagande observation, intervjuer och granskning av dokument. Det empiriska materialet visar på Half Moons aktiva arbete för mångfald och för att göra verksamheten och deltagandet tillgängligt för alla barn och unga. Teatern blir en mötesplats genom vilken ungdomarna kan lära sig acceptera och uppskatta mångfalden i samfundet. Teaterarbetet bidrar till en ökad känsla för samfundet och till tolerans och förståelse för andra. Det är en glädjefylld, trygg och meningsfull fritidsverksamhet där nya vänskapskontakter kan knytas och många färdigheter övas inför framtiden. Teaterarbetet ger deltagarna bekräftelse vilket bidrar till att självförtroendet växer. Personalens engagemang och osjälviska arbete för inklusion genomsyrar verksamheten. Möjligheten att ge alla en ny chans och ett jämlikt bemötande är centralt i teaterns arbete. Forskningsresultaten pekar på teaterns potential inom socialt arbete och för att främja inklusion. Teaterns möjligheter att öka klientens delaktighet och utveckla förhållandet mellan socialarbetare och klient visar på betydelsen av etablera dylik verksamhet inom socialt arbete. Att inte låta sig begränsas, utan förutsättningslöst samarbeta över sektorer ökar chanserna att finna nya kreativa idéer och verksamhetsformer.

Electrobioleaching of base metal sulfides

Bioleaching of base metal sulfides, such as pyrite, chalcopyrite, and sphalerite, under the influence of applied direct current (DC) potentials is discussed. Contributions toward mineral dissolution from three effects, namely, galvanic, applied potential, and microbiological, are analyzed and compared. Sphalerite could be selectively bioleached in the presence of Thiobacillus ferrooxidans under an applied potential of -500 mV (SCE) from mixed sulfides containing sphalerite, pyrite, and chalcopyrite. Bacterial activity and growth were found to be promoted under electrobioleaching conditions. Probable mechanisms involved in the bioleaching of different sulfides under positive and negative applied potentials are discussed.

Erfarenheter av yrkesinriktad rehabilitering. Lantbruksföretagarnas berättelser om yrkesinriktad rehabilitering ur ett identitetsperspektiv.

Den här avhandlingen handlar om lantbruksföretagare som genomgått yrkesinriktad rehabilitering. De har blivit tvungna att omskola sig till ett nytt yrke efter att de har insjuknat i yrkessjukdom eller skadat sig i ett olycksfall. Avhandlingens syfte är att öka förståelsen av hurdana erfarenheter lantbruksföretagare har av sin rehabiliteringsprocess. Rehabiliteringsätgärden, i det här fallet omskolningen, baserar sig på lagen om rehabilitering som ersätts enligt lagen om olycksfallsförsäkring. Materialet i avhandlingen bestär av 21 livsberättelser skrivna av de rehabiliterade som genomgått omskolningen. Undersökningen är därför narrativ tili sin natur. Analysen gjorde jag med hjälp av innehållsanalys och med hjälp av att tematisera innehållet i berättelserna. Tematiseringen var en central metod genom hela analysen och fungerade som ett redskap för att beskriva och tolka materialet. Rehabiliteringsprocessen frän början till slut ser jag även som ett identitetsprojekt och en process dar de rehabiliterade har varit tvungna att göra biografiskt arbete. Jag baserar min processindelning pä Corbin's och Strauss' (1988) defmition om att biografiskt arbete vid en krissituation i livet eller livsförändring innefattar fyra processer; kontextualisering, accepterande, äteruppbyggande av identiteten och omarbetning av biografin. Jag definierar insjuknandet eller skadan som en gemensam livsförändring för de rehabiliterade. De rehabiliterade har varit tvungna att konstruera en ny eller delvis en ny biografisk identitet som stämmer överens med de nya aktuella livsförhällandena, med framtida livsförhällanden och med tidigare erfarenheter. För största delen av de rehabiliterade hade rehabiliteringsprocessen varit en positiv erfarenhet och de hade lyckats med det biografiska arbetet för att återuppbygga identiteten och omarbeta biografin. Det var bara några av de rehabiliterade som ansåg att de inte hade haft någon nytta av rehabiliteringen. Det var personer som inte hade fått arbete efter omskolningen. Positiva studieerfarenheter och att man lyckas skaffa sig en utbildning i vuxen älder har för många varit faktorer som har gett dem bättre självkänsla och ökat deras självförtroende och dessutom skapat resurser för att kunna gå vidare i livet.

Serotypic and genotypic characterization of human serotype 10 rotaviruses from asymptomatic neonates

Human rotaviruses were isolated from asymptomatic neonates at various hospitals and clinics in the city of Bangalore, India, and were found to be subgroup I specific and possess long RNA patterns (M. Sukumaran, K. Gowda, P. P. Maiya, T. P. Srinivas, M. S. Kumar, S. Aijaz, R. R. Reddy, L. Padilla, H. B. Greenberg, and C. D. Rao, Arch. Virol. 126:239-251, 1992). Three of these strains were adapted to tissue culture and found by serotype analysis and neutralization assays to be of serotype 10, a serotype commonly found in cattle but infrequently found in humans and not previously identified in neonates. By RNA-RNA hybridization, a high level of relatedness to a serotype 10 bovine rotavirus strain and a low-to-medium level of relatedness to a human rotavirus strain were observed. Since this human isolate shares a genogroup with bovine rotavirus, it is likely that it originated by interspecies transmission. A human rotavirus strain isolated from asymptomatic neonates and similar to bovine rotavirus might represent a good vaccine candidate.

Structure of a steriod fungal metabolite

3a,7a, 14a-Trihydroxypregn-16-en-20-one, C21H3204, M r = 348.48, orthorhombic, P212121, a = 9.211 (1), b = 13.201 (1), c = 16.031 (1),~, V = 1949.28 (29)/~3, Z = 4, Dx = 1.187 g cm -3, A(Cu Ka), = 1.5418 ,~,/z = 6.07 cm-l, F(000) = 760, T= 293 K, R = 0.061 for 1337 observations. The A, B and C rings adopt normal chair conformations with the D ring in a 14a-envelope conformation. The molecules are held together by two hydrogen bonds [0(3)..'0(20) = 2.879 and O(7).--O(14)= 2.612 A,].

A simple equivalent circuit analysis of rectangular folded-waveguide slow-wave structure

A simple yet accurate equivalent circuit model was developed for the analysis of slow-wave properties (dispersion and interaction impedance characteristics) of a rectangular folded-waveguide slow-wave structure. Present formulation includes the effects of the presence of beam-hole in the circuit, which were ignored in existing approaches. The analysis was benchmarked against measurement as well as with 3D electromagnetic modeling using MAFIA for two typical slow-wave structures operating in Ka- and Q-bands, and close agreements were observed. The analysis was extended for demonstrating the effect of the variation of beam-hole radius on the RF interaction efficiency of the device. (C) 2009 Elsevier GmbH. All rights reserved.

Surface Chemistry of Thiobacillus ferrooxidans Relevant to Adhesion on Mineral Surfaces

Thiobacillus ferrooxidans cells grown on sulfur, pyrite, and chalcopyrite exhibit greater hydrophobicity than ferrous ion-grown cells. The isoelectric points of sulfur-, pyrite-, and chalcopyrite-grown cells were observed to be at a pH higher than that for ferrous ion-grown cells. Microbe-mineral interactions result in change in the surface chemistry of the organism as well as that of the minerals with which it has interacted. Sulfur, pyrite, and chalcopyrite after interaction with T. ferrooxidans exhibited a significant shift in their isoelectric points from the initial values exhibited by uninteracted minerals. With antibodies raised against sulfur-grown T. ferrooxidans, pyrite- and chalcopyrite-grown cells showed immunoreactivity, whereas ferrous ion-grown cells failed to do so. Fourier transform infrared spectroscopy of sulfur-grown cells suggested that a proteinaceous new cell surface appendage synthesized in mineral-grown cells brings about adhesion to the solid mineral substrates. Such an appendage was found to be absent in ferrous ion-grown cells as it is not required during growth in liquid substrates.

Microstructure evolution and hardness variation during annealing of equal channel angular pressed ultra-fine grained nickel subjected to 12 passes

The microstructure, thermal stability and hardness of ultra-fine grained (UFG) Ni produced by 12 passes of equal channel angular pressing (ECAP) through the route Bc were studied. Comparing the microstructure and hardness of the as-ECAPed samples with the published data on UFG Ni obtained after 8 passes of ECAP through the route Bc reveals a smaller average grain size (230 nm in the present case compared with 270 nm in 8-pass Ni), significantly lower dislocation density (1.08 x 10(14) m(-2) compared with 9 x 10(14) m(-2) in 8-pass Ni) and lower hardness (2 GPa compared with 2.45 GPa for 8-pass Ni). Study of the thermal stability of the 12-pass UFG Ni revealed that recovery is dominant in the temperature range 150-250A degrees C and recrystallisation occurred at temperatures > 250 A degrees C. The UFG microstructure is relatively stable up to about 400 A degrees C. Due to the lower dislocation density and consequently a lower stored energy, the recrystallisation of 12-pass ECAP Ni occurred at a higher temperature (similar to 250 A degrees C) compared with the 8-pass Ni (similar to 200 A degrees C). In the 12-pass Nickel, hardness variation shows that its dependence on grain size is inversely linear rather than the common grain size(-0.5) dependence.

Analysis of serpentine folded-waveguide slow-wave structure using elliptical conformal transformation

Elliptical conformal transformation was used to derive closed form expressions for the equivalent circuit series inductance and shunt capacitance per period of a serpentine folded-waveguide slow-wave structure including the effects of the beam-hole. The lumped parameters were subsequently interpreted for the dispersion and interaction impedance characteristics of the structure. The analysis was benchmarked for two typical millimeter-wave structures operating in Ka- and W-bands, against measurement, 3D electromagnetic modeling using CST Microwave Studio, parametric analysis and equivalent circuit analysis. (C) 2010 Elsevier GmbH. All rights reserved.

Ball wear mechanisms and control in the grinding of sulfide and phosphate ores

Marked ball grinding tests were carried out in the laboratory using high carbon low alloy steel (cast and forged) and high chrome cast iron balls. Relative ball wear as a function of grinding period and milling conditions was evaluated for the different type of ball materials in the grinding of lead-zinc sulphide and phosphate ores. Results indicated that ball wear increased with time and showed a sharp increase for wet grinding over dry grinding. Ball wear under wet grinding conditions was also influenced by the gaseous atmosphere in the mill. The influence of oxygen on the corrosive wear of grinding balls was increasingly felt in case of sulphide ore grinding. The grinding ball materials could be arranged in the following order with respect to their overall wear resistance: