Accounting for much of the landscape of southern England, chalk stream environments hold significant cultural, economic and ecological value. However, attempts to retain this value are often hindered by the remnants of historic management practices that have occurred across several millennia, as well as contemporary demands upon chalk stream amenity, including water abstraction, recreational use and fisheries management. One land-use that is believed to have a detrimental effect upon chalk streams, but which has been inadequately researched, is cattle grazing. Within this thesis the effects of cattle grazing in English chalk streams are assessed using a range of techniques. Terrestrial laser-scanning is employed to show that cattle can cause small, local changes in river bank topography. Direct and remote observations are used to link cattle behaviour to landscape utilisation, and a staticially significant correlation between air temperature and in-stream cattle activity is identified. Laboratory faecal analysis is conducted to establish the nutrient loading due to cattle, with results showing that cattle faeces contain signfiicant concentrations of phosphate. In-stream water turbidity monitoring is combined with remotely sensed cattle behaviour data to demonstrate that in-stream cattle activity has a minimal effect upon suspended sediment concentrations in an English chalk stream. A study using the diffuse fine sediment risk model, SCIMAP, highlights the hydrologically disconnected nature of English chalk streams, with model outputs concluding that topography, rather than land-use (cattle grazing), is the key control on diffuse fine sediment risk in English chalk streams. Combined, these individual findings provide a detailed, inter-disciplinary assessment that concludes the effects of cattle grazing in English chalk streams are different to those recorded in research from other environments, with physio-chemical effects (i.e. nutrient loading) being of greater significance than geomorphological agency (i.e. river bank destabilisation). This overarching conclusion has implications for the management of cattle grazing in English chalk streams, and these are discussed.

Amningsfrekvensen i Värmland sjunker och är låg jämfört med riket. En bidragande faktor till den sjunkande amningsfrekvensen är bristen på tillit till amning. Det är viktigt att kunna identifiera kvinnor med låg tillit till amning för att vända den sjunkande amningsfrekvensen och stärka kvinnan i rollen som moder. Syfte: Syftet med denna studie var att undersöka kvinnors tillit till amning på Barnbördshuset (BB) och Eftervårdsmottagningen i Värmland. Med enkäten BSES-SF identifieras kvinnor med låg tillit till amning och kvinnor som behöver ett ökat amningsstöd efter förlossning. Design/Metod: Studien utfördes med kvantitativ ansats. Data inhämtades från enkäten BSES-SF som besvarats av 70 kvinnor på BB och Eftervårdsmottagningen i Värmland. All data analyserades genom SPSS. Resultat: De flesta kvinnor ansåg att det var mycket viktigt med en fungerande amning och när kvinnorna skattade amningens betydelse framkom ett medelvärde på 8,66 där 0=inte alls viktigt och 10=mycket viktigt. Kvinnor som ammat tidigare skattade sin upplevda amningserfarenhet som mycket god. Varje enskild fråga på BSES-SF jämfördes mellan kvinnorna som vårdats på BB och Eftervårdsmottagningen. Det framkom en skillnad på åtta frågor där kvinnorna på Eftervårdsmottagningen skattade en högre tillit till amning jämfört med kvinnorna på BB. Utifrån totalsumman på BSES-SF med ett poängintervall mellan 14-70, framkom det att tilliten till amning skattades högre hos kvinnorna på Eftervårdsmottagningen (M=56,54) än på BB (M=49,88). Slutsats och klinisk tillämpbarhet: BSES-SF kan utifrån studiens resultat vara ett användbart verktyg, framförallt på BB där kvinnorna skattat en lägre tillit till amning. Förstföderskor och omföderskor som upplevt en komplicerad förlossning kan vara i behov av större insatser av amningsstöd. Studiens resultat kan medföra att barnmorskan blir extra uppmärksam på de kvinnor vars amning inte fungerar och där extra stöd behövs för att öka tilliten. / Breastfeeding frequency in Värmland decreases and is low compared with the national average. A contributing factor to the decline in breastfeeding rates is the lack of confidence in breastfeeding. It is important to identify women with low confidence to reverse the decline in breastfeeding frequency and strengthen her in her role as a mother. Objective: The aim of this study was to investigate breastfeeding and self-efficacy in the Postnatal ward and Postnatal carecenter in Värmland. Using BSES-SF survey, women with low confidence in breastfeeding and women who need an increased breastfeeding support after delivery were identified. Design/Methods: The study was conducted with a quantitative approach. Data whas collected from BSES-SF, answered by 70 women in Postnatal ward and Postnatal carecenter in Värmland. All data were analyzed by SPSS. Results: Most women felt that it was very important to have a functioning breastfeeding and when the women estimated the importance of breastfeeding it showed a mean of 8.66, where 0 = not at all important and 10 = very important. Women who breastfed previously rated their perceived breastfeeding experience as very good. Every single question on BSES-SF whas compared between women who were treated in Postnatal ward and Postnatal carecenter. It showed a difference in eight questions, the women on the Postnatal carecenter estimated a higher confidence in breastfeeding compared with women in the Postnatal ward. The total sum of BSES-SF with a score range between 14-70, showed that trust in lactation whas estimated higher among women in the Postnatal carecenter (M = 56.54) than in the Postnatal ward (M = 49.88). Conclusion and clinical applicability: Primaparas and women with prior deliveries who now experienced a complicated childbirth may need extra breastfeeding support. The result of the study may leed to extra attention from the midwife to those women whose breastfeeding does not work and where additional support is needed to increase confidence. Based on the studys result BSES-SF can be a useful tool, especially in the Postnatal ward where women estimated a lower confidence in breastfeeding.

This study focuses on the analysis and assessment of competitiveness within the Uruguayan broiler industry. Porter's (1990) 'national diamond' was selected as the appropriate framework for analysis and was applied to the six major Uruguayan broiler firms. This research reveals that the unique characteristics of the Uruguayan broiler industry are successfully accommodated within the selected framework to explain the success of the broiler industry against other meat substitutes. Therefore, this study has confirmed Porter's (1990) diamond system as an adequate conceptualization of success in the Uruguayan broiler industry. These results are consistent with those found in the existing literature, lending support to the view that Porter's (1990) model seems to be applicable to developing countries such as Uruguay. However, some modifications of the model are required to fully explain the progress of this industry. This research project presents an adaptation of Porter's (1990) 'diamond' to the singularities of the firms investigated in this study. This study opted for an industry-level case study research strategy that is operationalized through in-depth personal interviews with owner directors and managers in six of the seven possible organizations within Uruguay. This is augmented by further data collection (additional interviews) through sources in government and market relevant bodies in order to generate information on the national context. The selected research method showed its utility for the investigation of weaknesses and strengths within the Uruguayan broiler industry. These findings were used to accomplish the second objective of this research which was to elaborate policy recommendations out of the primary and secondary collected data that would help Uruguayan broiler firms to compete with international broiler firms in a regional economic block (MERCOSUR) without barriers.

FROTA, Diego Araujo. Estudo de um sistema supercondutor-ferromagneto: efeitos da aplicação de campo magnético e corrente elétrica. 2016. 72 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2016-04-14T18:02:17Z No. of bitstreams: 1 2016_tese_dafrota.pdf: 22222249 bytes, checksum: 3c4b2e4990667c1280e4839ee1d811ac (MD5) / Approved for entry into archive by Edvander Pires (edvanderpires@gmail.com) on 2016-04-14T18:03:42Z (GMT) No. of bitstreams: 1 2016_tese_dafrota.pdf: 22222249 bytes, checksum: 3c4b2e4990667c1280e4839ee1d811ac (MD5) / Made available in DSpace on 2016-04-14T18:03:42Z (GMT). No. of bitstreams: 1 2016_tese_dafrota.pdf: 22222249 bytes, checksum: 3c4b2e4990667c1280e4839ee1d811ac (MD5) Previous issue date: 2016 / Using advanced Ginzburg-Landau simulations, we study the superconducting state of a thin super- conducting film under a ferromagnetic layer, separated by an insulating oxide, in applied external magnetic field and electric current. The taken uniaxial ferromagnet is organized into a series of parallel domains with alternating polarization of out-of-plane magnetization, sufficiently strong to induce vortex-antivortex pairs in the underlying superconductor in absence of other magnetic field. We show the organization of such vortex-antivortex matter into rich configurations, some of which are not matching the periodicity of the ferromagnetic film. The variety of possible configurations is enhanced by applied homogeneous magnetic field, where additional vortices in the superconductor may lower the energy of the system by either annihilating the present antivortices under negative ferromagnetic domains, or by lowering their own energy after positioning under positive ferromag- netic domains. As a consequence, both the vortex-antivortex reordering in increasing external field and the evolution of the energy of the system are highly nontrivial. Finally, we reveal the very inter- esting effects of applied dc electric current on the vortex-antivortex configurations, since resulting Lorentzian force has opposite direction for vortices and antivortices, while direction of the applied current with respect to ferromagnetic domains is of crucial importance for the interaction of the applied and the Meissner current, as well as the consequent vortex-antivortex dynamics - both of which are reflected in the anisotropic critical current of the system. / A partir da solução numérica das equações de Ginzburg-Landau, estudamos o estado supercondutor de um filme fino supercondutor sob uma camada ferromagnética, separados por um óxido isolante, na presença de campo magnético ou corrente elétrica aplicados. O ferromagneto considerado é organizado em uma série de domínios paralelos com magnetização oposta, perpendicular ao plano do ferromagneto, e suficientemente forte para induzir pares vórtice-antivórtice no supercondutor subjacente, quando na ausência de campo magnético aplicado. Pares vórtice-antivórtice se auto-organizam em um rico conjunto de configurações, algumas das quais não apresentam correspondência com a periodicidade do filme ferromagnético. A variedade das possíveis configurações é aumentada pela aplicação de campo magnético externo, caso em que vórtices adicionais podem diminuir a energia do sistema pela aniquilação dos antivórtices, que estão sob os domínios negativos do ferromagneto, ou diminuindo sua própria energia após se posicionarem sob domínios positivos do ferromagneto. Como consequência, o reodernamento de vórtices-antivórtices bem como a evolução da energia do sistema são não-triviais em função do aumento da intensidade do campo magnético externo. Por fim, revelamos efeitos curiosos da corrente elétrica dc aplicada sobre as configurações de pares vórtice- antivórtice, uma vez que a força de Lorentz resultante tem direção oposta para vórtices e antivórtices, enquanto que a direção da corrente aplicada em relação aos domínios ferromagnéticos é de importância crucial para a interação das correntes e Meissner e aplicada, bem como a dinâmica de vórtice-antivórtice resultante - ambas as quais estão refletidas na anisotropia da corrente crítica do sistema.

coordenadoria de aperfeiÃoamento de pessoal de ensino superior / A partir da soluÃÃo numÃrica das equaÃÃes de Ginzburg-Landau, estudamos o estado supercondutor de um filme fino supercondutor sob uma camada ferromagnÃtica, separados por um Ãxido isolante, na presenÃa de campo magnÃtico ou corrente elÃtrica aplicados. O ferromagneto considerado à organizado em uma sÃrie de domÃnios paralelos com magnetizaÃÃo oposta, perpendicular ao plano do ferromagneto, e suficientemente forte para induzir pares vÃrtice-antivÃrtice no supercondutor subjacente, quando na ausÃncia de campo magnÃtico aplicado. Pares vÃrtice-antivÃrtice se auto-organizam em um rico conjunto de configuraÃÃes, algumas das quais nÃo apresentam correspondÃncia com a periodicidade do filme ferromagnÃtico. A variedade das possÃveis configuraÃÃes à aumentada pela aplicaÃÃo de campo magnÃtico externo, caso em que vÃrtices adicionais podem diminuir a energia do sistema pela aniquilaÃÃo dos antivÃrtices, que estÃo sob os domÃnios negativos do ferromagneto, ou diminuindo sua prÃpria energia apÃs se posicionarem sob domÃnios positivos do ferromagneto. Como consequÃncia, o reodernamento de vÃrtices-antivÃrtices bem como a evoluÃÃo da energia do sistema sÃo nÃo-triviais em funÃÃo do aumento da intensidade do campo magnÃtico externo. Por fim, revelamos efeitos curiosos da corrente elÃtrica dc aplicada sobre as configuraÃÃes de pares vÃrtice- antivÃrtice, uma vez que a forÃa de Lorentz resultante tem direÃÃo oposta para vÃrtices e antivÃrtices, enquanto que a direÃÃo da corrente aplicada em relaÃÃo aos domÃnios ferromagnÃticos à de importÃncia crucial para a interaÃÃo das correntes e Meissner e aplicada, bem como a dinÃmica de vÃrtice-antivÃrtice resultante - ambas as quais estÃo refletidas na anisotropia da corrente crÃtica do sistema. / Using advanced Ginzburg-Landau simulations, we study the superconducting state of a thin super- conducting film under a ferromagnetic layer, separated by an insulating oxide, in applied external magnetic field and electric current. The taken uniaxial ferromagnet is organized into a series of parallel domains with alternating polarization of out-of-plane magnetization, sufficiently strong to induce vortex-antivortex pairs in the underlying superconductor in absence of other magnetic field. We show the organization of such vortex-antivortex matter into rich configurations, some of which are not matching the periodicity of the ferromagnetic film. The variety of possible configurations is enhanced by applied homogeneous magnetic field, where additional vortices in the superconductor may lower the energy of the system by either annihilating the present antivortices under negative ferromagnetic domains, or by lowering their own energy after positioning under positive ferromag- netic domains. As a consequence, both the vortex-antivortex reordering in increasing external field and the evolution of the energy of the system are highly nontrivial. Finally, we reveal the very inter- esting effects of applied dc electric current on the vortex-antivortex configurations, since resulting Lorentzian force has opposite direction for vortices and antivortices, while direction of the applied current with respect to ferromagnetic domains is of crucial importance for the interaction of the applied and the Meissner current, as well as the consequent vortex-antivortex dynamics - both of which are reflected in the anisotropic critical current of the system.

No description available.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

As nutrition is of central importance to cattle fertility, this study sought to assess how veterinarians and nutritional advisers manage trace element imbalance in the UK; diagnosis and treatment. The study also sought to develop a robust system for oocyte recovery (ovum pick-up (OPU)) and in vitro embryo production (IVP) for commercial use, and to identify key factors influencing success, including oestrus synchrony and ovarian stimulation prior to OPU. The intention originally was to use OPU/IVP to investigate the impact of mineral imbalances on bovine oocyte quality, early embryo development and pregnancy establishment following embryo transfer (ET). In the first survey of its kind in the UK, the understanding and approach of advisers to mineral nutrition on farms was investigated. Of the 173 respondents, 78% were vets in practice. The overall importance of minerals was recorded by vets as low 33%, medium 37%, and high 30%, while non-vets scored importance as low 17%, medium 48%, and high 35%. There was little consensus amongst the advisers, or within the vet and non-vet subgroups about mechanisms and interactions associated with deficiency, and particularly of copper responsive conditions. The most frequently identified deficiencies were selenium, copper and iodine, while the most commonly identified toxicity was molybdenum. For copper responsive conditions, all of the listed treatments were used at least "occasionally"; the most frequently being glass boluses, in-feed supplementation, matrix boluses, and then copper injections. While there was a diverse choice of treatments, altering the ration was relatively rarely selected. This thesis also provides the first large-scale retrospective analysis of factors influencing the establishment of a commercially robust ovum pick up (OPU) and in vitro embryo production (IVP) platform in the UK. Over a 5-year period, a system was developed and validated for use in the UK with 2,138 cycles of OPU. These cycles were analysed as four sets of data and included two IVP laboratories and 6 OPU teams. Factors in these analyses included OPU team, IVP laboratory, ovarian stimulation protocol and semen type (unsorted vs sex-sorted). The mean number of follicles aspirated by the OPU teams ranged from 6.5 to 14.9 (P < 0.001), while the number of oocytes collected was between 4.0 and 12.4 (P < 0.001). There was an indication (P=0.055) that the blastocyst per oocyte rate varied between teams. The proportion of blastocysts from oocytes that cleaved was higher (P=0.01) for unsorted than sexed semen. Two commercial products containing different ratios of follicle stimulating hormone (FSH) to luteinising hormone (LH) (Folltropin® and Pluset®) were compared in ovarian stimulation programs. The addition of 'coasting' (short-term (typically 48h) hormonal withdrawal after FSH stimulation), prior to OPU was also investigated. Pluset® resulted in a greater (P < 0.001) mean number of follicles aspirated, more (P=0.003) blastocysts per oocyte matured and more (P < 0.001) embryos per cycle (2.45), compared with Folltropin® (1.17) or with no stimulation (1.24). Throughout the study there was a steady improvement in blastocyst production per OPU cycle. In a separate analysis, Grade 1 cumulus oocyte complexes (COCs) as a proportion of COCs recovered, oocytes that cleaved as a proportion of total COCs, and blastocysts as a proportion of total COCs, were all greater (P < 0.05) for stimulated than non-stimulated cycles, irrespective of FSH/LH product. A composite score of oocyte quality and quantity was proposed (sCOC); Log Total Mean sCOC was correlated (P < 0.001) with both the proportion of blastocysts per oocyte collected, and the total number of embryos produced per cycle. Finally, twelve peri-pubertal heifers (approximately 10 months old) participated in a crossover trial which compared PRID® (Delta®) vs CIDR® progesterone releasing intravaginal devices for use in OPU/IVP cycles. Vaginoscopic examination found higher vaginal inflammation grades for PRID® than CIDR® (P < 0.001). There was evidence of vaginal inflammation continuing for at least 2 weeks after device withdrawal. The proportion cleaved of oocytes inseminated was higher for PRID® than CIDR® (P < 0.05). Numerically but not significantly there was a higher proportion of blastocysts per cycle and a higher Log Total Mean sCOC score per cycle with PRID® than CIDR® treatments, but blastocyst yield was low throughout, suggesting a need to repeat the trial. Data collection and analyses are ongoing, to identify other key performance indicators within the OPU/IVP embryo transfer (ET) system, with a view to refining the sCOC composite score model. A robust OPU/IVP/ET system has been developed and this could be used to investigate further how mineral imbalances impact oocyte competence and blastocyst yield.

To date there are no effective treatments for prion diseases, and these diseases are always fatal in both humans and animals. Additionally, the gold standard for diagnosis of these disease remains to be the analysis of biopsied brain tissue obtained post mortem. Consequently, there is a continued demand for therapeutics and ante-mortem diagnostics for prion diseases. This project addresses these demands by investigating candidate therapeutic and diagnostic ligands for prion diseases. This study investigated recombinant prion proteins (rPrPs) as inhibitors in scrapie and bovine spongiform encephalopathy (BSE) in vitro amplification by protein misfolding cyclic amplification (PMCA). Three ovine rPrPs with the polymorphisms VRQ, ARQ and ARR and hamster rPrP were tested against scrapie PMCA in dilution series to calculate IC50 values. The two most potent inhibitors, VRQ and ARQ, were then similarly tested against bovine spongiform encephalopathy (BSE) amplification. The most potent inhibitor of both disease types, the ovine rPrP VRQ, was then observed to inhibit a range of different scrapie and BSE strains at a fixed concentration. It is recommended that further investigation into rPrP inhibitors is performed. Strain characterisation of scrapie was investigated using rPrP inhibitors, following observations that the rPrP inhibitors generate a pattern of inhibition at a set concentration. Although this pattern of inhibition was repeatable in scrapie amplification by PMCA, this was limited to a single round of PMCA. Ultimately, this limited the application of this method to only amplification efficient prion strains and isolates. It is recommended that this method be investigated further in combination with the amplification of different isolates in substrates of different genotypes over multiple rounds of PMCA, as well as the analysis of glycoform ratios by western blotting. Here it was also identified that the imidazole used in the elution buffer for immobilised metal affinity chromatography (IMAC) can inhibit prion amplification in a strain dependent manner. This inhibition could be used in combination with the proposed method as a multi-faceted assay of prion strain characterisation. The use of next generation phage display (NGPD) to map the epitopes of autoantibodies in the sera of scrapie infected sheep was also investigated. This was performed to identify peptides that were immunoreactive to autoantibodies specific to the disease state. The identification of diagnostic peptides would then enable the development of an ante-mortem serological diagnostic test for scrapie. NGPD successfully selected immunoreactive peptides, of which 39 were selected for validation by peptide enzyme-linked immunosorbent assays (ELISAs). Although none of the peptides demonstrated diagnostic specificity by peptide ELISA, an optimised ELISA methodology was developed for future use in the validation of NGPD selected peptides. Further variations in the NGPD method, as well as validation by immunoassay, can be investigated to identify diagnostic peptides immunoreactive to scrapie specific autoantibodies.

Using patch clamp and Ca2+ imaging techniques, we have studied Ca2+ entry pathways in human hepatoblastoma (HepG2) cells. These cells express the mRNA of TRPV1, TRPV2, TRPV3 and TRPV4 channels, but not those of TRPV5 and TRPV6. Functional assessment showed that capsaicin (10 μM), 4α-phorbol-12,13-didecanoate (4αPDD, 1 μM), arachidonic acid (10 μM), hypotonic stress, and heat all stimulated increases in [Ca2+]i within minutes. The increase in [Ca2+]i depended on extracellular Ca2+ and on the transmembrane potential, which indicated that both driving forces affected Ca2+ entry. Capsaicin also stimulated an increase in [Ca2+]i in nominally Ca2+-free solutions, which was compatible with the receptor functioning as a Ca2+ release channel. Hepatocyte growth factor/scatter factor (HGF/SF) modulated Ca2+ entry. Ca2+ influx was greater in HepG2 cells incubated with HGF/SF (20 ng/ml for 20 h) compared with non-stimulated cells, but this occurred only in those cells with a migrating phenotype as determined by presence of a lamellipodium and trailing footplate. The effect of capsaicin on [Ca2+]i was greater in migrating HGF/SF-treated cells, and this was inhibited by capsazepine. The difference between control and HGF/SF-treated cells was not found in Ca2+-free solutions. 4αPDD also had no greater effect on HGF/SF-treated cells. We conclude that TRPV1 and TRPV4 channels provide Ca2+ entry pathways in HepG2 cells. HGF/SF increases Ca2+ entry via TRPV1, but not via TRPV4. This rise in [Ca2+]i may constitute an early response of a signalling cascade that gives rise to cell locomotion and the migratory phenotype.