In South Africa and other parts of sub-Saharan Africa, market participation of smallholder farmers are rapidly being advocated as a means to achieve the United Nations Sustainable Development Agenda’s (SDGs): zero hunger and no poverty. Yet little is known about market participation in the sunflower industry. The study therefore, examine market participation of smallholder sunflower farmers in Ngaka Modiri Molema District Municipality, North West Province, South Africa. A quantitative research approach was developed to address the research objectives, and a proportional stratified random sampling technique was used to select 177 sunflower producing households. Respondents information were captured using semi-structured questionnaires, data were then entered and coded using statistical software computer programs (MS Excel, SPSS, and Stata). Socio-economic characteristics, level of market participation, and factors influencing households market participation within the district were analyzed using descriptive statistics, household commercialization index, and probit regression model. Overall, the result indicates that respondents exhibited high level of commercialization (90.1 % market participants). While, the result of the probit regression model shows that eight (8) of the regressors were statistically significant. Variables such as age (Coef = 0.103, p<0.01), gender (Coef = 1.267, p<0.05), market outlet (Coef = 1.351, p<0.01), access to information (Coef = 1.298, p<0.05), and quantity sold in tons (Coef = 0.015, p<0.010) were found to have positive and statistically significant influence, while household size (Coef = -0.409, p<0.01), market distance (Coef = 0.618, p<0.010) and land tenure system (Coef = -1.541, p<0.05) were found to have a negative but statistically significant impact on market participation among respondents. The pseudo R2 of the probit model is 0.5199, indicating that the model matches the dataset and the regressors accurately explains 51.99 % of the variation. The overall goodness of fit measures of the probit model was determined using postestimation test for predictive margin. With a high significant chi-square value of (p<0.0001), the result correctly predicted a 90 % likelihood of respondents to participate in the market. The findings suggests that rural-based initiatives and intervention programs be developed to boost households' access to finance, grants, and diversified markets for effective market competitiveness, while there is a greater need for proper awareness, supports, and partnerships focused on promoting women and youth participation in the sunflower sector across the district. / Agriculture and  Animal Health / M. Sci. (Agriculture)

Si bien se ha realizado una intensa selección genética a favor de frutos de girasol con mayor valor agronómico (mayor peso y contenido de materia grasa, resistencia a enfermedades, etc.) sorprende la escasez de información referida a los eventos anatómicos que controlan su crecimiento y madura-ción. La dinámica y el grado de superposición de los procesos de división y aumento de volumen celular y diferenciación de tejidos del ovario y pericarpo, y del óvulo, saco embrionario y semilla, que definen el peso y la estructura final que alcanza el fruto de girasol, no han sido estudiados. Delimitar temporal o fenológicamente dichos procesos resulta información indis-pensable para plantear y comparar trabajos en que se inves-tiguen las relaciones e interacciones entre factores genéticos y ambientales sobre el peso y la estructura final que alcanza el fruto de girasol. Estos parámetros inciden sobre el rendimiento del cultivo y la facilidad con que la cáscara se separa de la pepa, la que puede evaluarse determinando la aptitud al descascarado (AD) de los frutos, durante su indus-trialización. Los objetivos de esta tesis fueron: 1) establecer un modelo de desarrollo histogénico del fruto de girasol en una escala temporal y fenológica, en dos híbridos de similar base genética que diferían en su AD; 2) Analizar las modificaciones que se producen en el patrón de desarrollo de los frutos de tres posiciones del capítulo, al reducir la radiación incidente sobre el cultivo en un 80% mediante sombreado durante la preantesis (Pre-A) y postantesis temprana (Post-A) y 3) Eva-luar el efecto que el genotipo y las modificaciones generadas por los tratamientos de estrés lumínico tienen sobre la AD y parámetros subyacentes de los frutos. El modelo de desarrollo de los frutos fue similar entre híbridos. Entre los estadios reproductivos R2 y R4 se produjo la diferenciación del saco embrionario y de los granos de polen. La división celular en la pared del ovario (futuro pericarpo) fue disminuyendo a partir de R2, no observándose células en división en R4, momento en que quedó fijado el tamaño potencial del pericarpo. El ta-maño final del pericarpo se estableció al completarse la escle-rificación y acumulación de materia seca del mismo, entre 10 y 13 días después de la antesis (DDA). El tamaño potencial del embrión se fijó 18 DDA cuando ya había transcurrido la etapa inicial del período de rápida acumulación de materia seca del embrión. Este período se extendió desde 11 DDA hasta, aproximadamente, 29 a 32 DDA cuando se registró el máximo peso del embrión y la madurez fisiológica (MF) del fruto. El sombreado de Pre-A redujo el período de acumulación de materia seca del pericarpo de los frutos de la posición interna del capítulo. El sombreado de Post-A también modificó la dinámica de crecimiento del pericarpo. Así, el peso del pericarpo (PP) de los frutos medios e internos se mantuvo constante desde el inicio del tratamiento hasta 4-7 días después de finalizado el mismo. Luego de ello, el PP se incrementó durante 3 a 4 días. En MF, la reducción en el PP (18 a 52%) y en el espesor (20-33%) de la capa media (ECM) del mismo fue similar entre tratamientos de sombreado. El sombreado de Pre-A redujo el número de estratos (NTE) e incrementó el grosor de las paredes celulares de la CM del pericarpo en la posición media e interna del capítulo. Por el contrario, el tratamiento de Post-A redujo el número de estratos esclerificados de la CM (NEECM) y el espesor y el contenido de celulosa, hemicelulosa y lignina de las paredes celulares del pericarpo en las tres posiciones del capítulo. En MF, el peso de los embriones (PE) de los frutos del sombreado de Pre-A, fue inferior al tratamiento control (Con) y el de los frutos de Post-A fue igual al de los frutos del control. Ello estuvo asociado a la reducción del número de células de los cotiledones de los frutos en las tres posiciones del capítulo, la duración del periodo de llenado de los embriones (PLLE) de los frutos externos, la tasa de crecimiento de los embriones (TCE) de los frutos medios y la TCE y el PLLE de los frutos en la posición interna en el sombreado de Pre-A. El sombreado de Post-A solo prolongó la duración de la fase de lento crecimiento del embrión (fase lag) de los frutos medios e internos. La reducción en el rendimiento por planta fue similar en ambos tratamientos de sombreado, variando, con respecto al Con, los componentes del rendimiento a través de los cuales se realizó el ajuste. Las plantas sombreadas en Pre-A presentaron el mismo número de frutos llenos, pero el peso individual de los mismos fue inferior al Con. Por el contrario, en el sombreado de Post-A se redujo el número de frutos llenos por planta, mientras que su peso individual fue similar al Con. La heterogeneidad entre los frutos de las distintas posiciones del capítulo no fueron modi-ficadas por los tratamientos de sombreado, y estuvieron asociadas a diferencias, en el número de células de los cotile-dones, excepto entre los frutos medios e internos del trata-miento de Pre-A, y en la TCE, excepto entre los frutos externos y medios del tratamiento de Post-A. Las variaciones en la AD de los frutos resultaron tanto consecuencia de dife-rencias entre híbridos como de las condiciones de manejo del cultivo (sombreado). Así, la frecuencia de radios de parén-quima por mm de sección transversal de pericarpo, que determinó las diferencias en la AD entre híbridos, se mantuvo, salvo ligeras variantes, constante entre localidades. La menor AD observada en el sombreado de Post-A, con respecto al tratamiento Con y al sombreado de Pre-A, estuvo asociada a la reducción en el grosor de las paredes celulares del pericarpo. Los resultados de esta tesis permiten avanzar en el marco actual de conocimiento sobre los procesos involucrados en la determinación de la estructura y peso final que alcanza el fruto de girasol, componente que incide sobre el rendi-miento del cultivo y la calidad de los subproductos obtenidos durante la industrialización de sus frutos. Además, constitu-yen el primer aporte que analiza los efectos del estrés lumínico (sombreado) sobre los cambios morfo-anatómicos asociados al crecimiento y desarrollo del pericarpo y/o embrión de girasol, así como, sobre las variaciones en la AD de sus frutos. Palabras clave: girasol, Helianthus annuus L., tamaño potencial del pericarpo, tamaño final del fruto, aptitud al descascarado, estrés lumínico. / In spite of the intense genetic selection to obtain sunflower fruits with a higher agronomic value (higher weight and oil content, resistance to diseases, etc.), there is a surprising lack of information on the developmental events that control their growth and maturity. No one has studied the dynamics and overlapping degree of the cell division and volume increase processes and the differentiation of ovary, pericarp, ovule, embryo sac and seed tissues which define the final weight and structure of the sunflower fruit. Understanding the timing and phenological definition of these processes is essential to proposing and comparing research on the relations and interactions between genetic and environmental factors determining final weight and structure (volume, weight and anatomic structure) of the sunflower fruit. These last variables have an impact on the crop yield and on the ability of the hull to separate from the seed, which can be assessed by establishing the dehulling ability (DA) of fruits during processing. The objectives of this thesis are: 1) to establish a histogenic development model, on both a time and a phenological scale, of the fruit of two sunflower hybrids with similar genetic background but with different fruit DA; 2) to analyze the modifications of the fruit development pattern, in three positions of the capitulum, with 80% reduction of incident radiation (shading) on the crop during preanthesis (Pre-A) and early postanthesis (Post-A); and 3) to assess the effect of genotype and light stress on the fruit DA and underlying parameters. The fruit development model was similar between hybrids. Differentiation of the embryo sac and the pollen grains took place between stages R2 and R4. The ovary wall (future pericarp) cell division decreased after R2, with no dividing cells found at R4, when the potential size of the pericarp was determined. The final size of the pericarp was established between 10 and 13 days after anthesis (DAA) upon completion of its sclerification and accumulation of dry matter. The embryo potential size was established by 18 DAA, when the initial stage of rapid dry matter accumulation of the embryo had already passed. The last stage lasted from the 11 DAA until about 29 to 32 DAA when the maximum weight of the embryo (MF) was recorded. Pre-A shading decreased the dry matter accumulation period of the pericarp in the capitulum central position. Post-A shading also modified the pericarp growth dynamics. In this way, the pericarp weight (PW) of the mid and central fruits remained constant during the treatment and for 4-7 days after it was completed. After that the PW increased during 3 to 4 days. At MF, the PW reduction (18 to 52%) and thickness (20-33%) of the middle layer (ML) of the pericarp was similar in both shading treatments. In the Pre-A treatment, the number of strata decreased and the thickness of the cell wall of the ML increased in the capitulum mid and central positions. On the contrary, the Post-A treatment decreased the number of sclerified strata of the ML, as well as the thickness and the content of cellulose, hemicellulose and lignin of the pericarp cell wall of the fruits from the three positions on the capitulum. At PM, the weight of the embryos (EW) from the Pre-A shade was lower than the EW of the Con and Post-A treatment fruits. The EW reduction was associated with the reduction in the cotyledon cells number at the three capitulum positions, the duration of the embryo filling period (EFP) of the peripheral fruits, the embryo growth rate (EGR) of mid fruits and the EGR and the EEP of central fruits from Pre-A shading. The Post-A shading extended the slow growth phase duration of the embryo (lag phase) of the central and mid fruits only. The reduction of yield per plant, with respect to Con, was similar in both shading treatments. The yield components responsible for the adjustments depended on the treatment. Pre-A shaded plants produced the same number of filled fruits but with a lower weight per fruit. On the contrary, in Post-A shading the number of filled fruits decreased while their individual weight was similar to Con. The heterogeneity among fruits in the different capitulum positions was not modified by the shading treatments, and it was associated to differences in cotyledons cell number, except for the mid and central fruits of the Pre-A treatment, and to EGR, except between peripheral and mid fruits of the Post-A treatment. Variations in the DA were both a consequence of the differences between hybrids and the crop management conditions (shading). Thus the frequency of parenchyma radii by mm of cross section of the pericarp, that determined the DA differences among hybrids, remained the same, except for slight variants, throughout locations. The lowest EW/PW ratio observed in Post-A shading with respect to Con treatment and the Pre-A shading, resulted from the PW reduction and not from EW, which was associated with a reduction in cell wall thickness and in the DA.The results of this thesis are the first contribution that analyzed the effects of light stress (shading) on the morphological and anatomical changes associated to growth and development of the sunflower pericarp and embryo. They improve our understanding of the processes involved in the determination of the structure and finalweight of the sunflower fruit, a component that impacts crop yield and also the quality of the byproducts of fruit processing. Keywords: sunflower, Helianthus annuus L., pericarp potential size, fruit final size, dehulling ability, light stress.

新聞報導是一種語藝的行動或一種說服之過程，也是一種真實的再現，透過不斷的傳播，建構出團體成員對外在世界的共同認知，逐漸成為閱聽人的共同印象。以社會運動來說，新聞工作者往往認為「衝突、對抗、造勢」等戲劇性效果，最具新聞價值，也最能代表社運，因此，媒體建構了社運，同時建構了人們對社運的印象。而以學生為主體的社會運動，因角色的轉換與社會的想像，使得媒體刻意在報導中多了些「保護」與「憐惜」，易產生與其它社會運動不同的報導取徑。 　　本研究以《聯合報》的野百合學運和太陽花學運的新聞報導作為研究對象，透過「幻想主題分析」的研究架構，輔以外在分析，探討單一媒體建構學運的語藝視野是否會隨著時代變遷而有所變化？ 　　研究發現，在《聯合報》語藝建構下，兩代學運呈現迥然不同的語藝視野，野百合學運的語藝視野為「憲政改革眾望所歸」和「民主自由難能可貴」；太陽花學運的語藝視野為「朝野惡鬥國會失能」和「民主之恥民主鬧劇」，並發現學運期間的讀者投書，具明顯的覆誦現象，形成一致的語藝社群，不僅如此，本研究同時驗證了單一媒體在建構不同世代學運的語藝視野，並不會全然產生相同的觀看視角與報導取徑。

The thesis brings a global insight into the Prague's suburb of Bohnice. Captures the appearance since the first settlements until nowadays. Focusing mainly on both historical and socio-economical milestones, which created the city. According to the lack of written resources for the historical part of the theses and to the fact, that Bohnice are often reduced to the activities of the famous mental institution, the main target is the forming of Bohnice city in the 20th century. Concentrates on institutions of both social and health care, which can compete the famous mental institution. The thesis also supplies materials about the urban concept of the housing estate of Bohnice including the traffic solutions through the past century. Points out also outstanding architectural solitaires.

<p>U&nbsp; radu&nbsp; je&nbsp; prikazana&nbsp; distribucija,&nbsp; dinamika&nbsp; i&nbsp; diverzitet&nbsp; insekata opra&scaron;ivača iz reda Hymenoptera&nbsp; -&nbsp; Apiformes (Anthophila) i Diptera Syrphidae)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; i&nbsp; na&nbsp; suncokretu&nbsp; u agroekosistema&nbsp; Vojvodine.&nbsp; U&nbsp; cilju&nbsp; uvida&nbsp; u&nbsp; strukturu&nbsp; predela&nbsp; injenog&nbsp; uticaja&nbsp; na&nbsp; sastav&nbsp; i&nbsp; brojnost&nbsp; polinatora,&nbsp; kartirani&nbsp; su&nbsp; tipovistani&scaron;ta&nbsp; oko&nbsp; svakog&nbsp; stepskog&nbsp; fragmenta.&nbsp; Na&nbsp; osnovu&nbsp; podataka dobijenih kartiranjem, odabrano je sedam stepskih fragmenata kojiu&nbsp; svom&nbsp; okruženju&nbsp; imaju&nbsp; visok&nbsp; udeo&nbsp; suncokreta&nbsp; kao&nbsp; masovnocvetajuće&nbsp; kulture&nbsp; i&nbsp; sedam&nbsp; stepskih&nbsp; fragmenata&nbsp; koji&nbsp; su&nbsp; bez&nbsp; ili&nbsp; saniskim&nbsp; udelom&nbsp; suncokreta.&nbsp; Iz&nbsp; reda&nbsp; Hymenoptera&nbsp; &ndash;&nbsp; Apoideazabeleženo&nbsp; je&nbsp; &scaron;est&nbsp; familija:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae,Halictidae,&nbsp; Melittidae&nbsp; i&nbsp; Megachilidae,&nbsp; 114&nbsp; vrsta,&nbsp; a&nbsp; iz&nbsp; reda&nbsp; Diptera(Syrphidae),&nbsp; registrovano&nbsp; je&nbsp; ukupno&nbsp; 11&nbsp; vrsta.&nbsp; Predstavnici&nbsp; familija Andrenidae, Apidae i Halictidae su distribuirani na svim lokalitetima,predstavnici&nbsp; familije&nbsp; Megachilidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; 15&nbsp; od&nbsp; 16lokaliteta,&nbsp; a&nbsp; najmanje&nbsp; su&nbsp; zastupljene&nbsp; jedinke&nbsp; familija&nbsp; Colletidae&nbsp; i<br />Melittidae,&nbsp; distribuirane&nbsp; na&nbsp; pet&nbsp; lokaliteta.&nbsp; Polinatori&nbsp; reda&nbsp; Diptera familije&nbsp; Syrphidae&nbsp; su&nbsp; distribuirani&nbsp; na&nbsp; svim&nbsp; lokalitetima.&nbsp; Rezultati Kruskal-Volisovog H testa ukuzuju da je tokom sve tri sezone (2011.,2012.,&nbsp; 2013.)&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; najvi&scaron;e&nbsp; bilo&nbsp; zastupljeno vrsta&nbsp; solitarnih&nbsp; pčela,&nbsp; zatim&nbsp; vrsta&nbsp; osolikih&nbsp; muva,&nbsp; a&nbsp; najmanje&nbsp; vrsta bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijano&nbsp; da&nbsp; je&nbsp; tokom&nbsp; sve&nbsp; tri&nbsp; sezone&nbsp; na stepskim&nbsp; fragmentima,&nbsp; registrovano&nbsp; najvi&scaron;e&nbsp; jedinki&nbsp; osolikih&nbsp; muva,<br />zatim&nbsp; medonosne&nbsp; pčele,&nbsp; solitarne&nbsp; pčele,&nbsp; a&nbsp; najmanje&nbsp; jedinki bumbara.&nbsp; Fridmanovim&nbsp; testom&nbsp; su&nbsp; utvrđene&nbsp; razlike&nbsp; u&nbsp; brojnosti (dinamici)&nbsp; polinatora&nbsp; kroz&nbsp; sezone,&nbsp; uočen&nbsp; je&nbsp; porast&nbsp; broja&nbsp; jedinki medonosne pčele i opadanje broja jedinki solitarnih pčela.Rezultati&nbsp; dobijeni&nbsp; Man-Vitnijevim&nbsp; U-testom&nbsp; pokazuju&nbsp; da&nbsp; je&nbsp; na<br />stepskim&nbsp; fragmentima&nbsp; koji&nbsp; imaju&nbsp; niži&nbsp; udeo&nbsp; suncokreta&nbsp; u&nbsp; predelu zastupljeno&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; i&nbsp; vrsta&nbsp; bumbara.&nbsp; Istim&nbsp; testom&nbsp; je&nbsp; dobijen rezultat&nbsp; da&nbsp; je&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; sa&nbsp; visokim&nbsp; udelom suncokreta&nbsp; ima&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; medonosne&nbsp; pčele.&nbsp; Vilkoksonovim testom&nbsp; sume&nbsp; rangova&nbsp; je&nbsp; pokazano&nbsp; da&nbsp; su&nbsp; jedinke&nbsp; i&nbsp; vrste&nbsp; bumbara zastupljenije na stepskim fragmentima nakon cvetanja suncokreta, za&nbsp; vreme&nbsp; cvetanja&nbsp; suncokreta&nbsp; na&nbsp; stepskim&nbsp; fragmentima&nbsp; je registrovano&nbsp; vi&scaron;e&nbsp; jedinki&nbsp; <em>Apis&nbsp; mellifera</em>,&nbsp; osolikih&nbsp; muva&nbsp; i&nbsp; solitarnih pčela.&nbsp; Modeli&nbsp; regresionih&nbsp; analiza&nbsp; linearnih&nbsp; me&scaron;ovitih&nbsp; modela&nbsp; su pokazali&nbsp; da&nbsp; se&nbsp; sa&nbsp; porastom&nbsp; udela&nbsp; suncokreta&nbsp; u&nbsp; predelu&nbsp; smanjuje broj jedinki divljih pčela i jedinki i vrsta bumbara. Sa porastom udela polu-prirodnih&nbsp; stani&scaron;ta&nbsp; u&nbsp; predelu&nbsp; i&nbsp; većom&nbsp; cvetnom&nbsp; pokrovnosti, povećava se udeo jedinki i vrsta osolikih muva.</p> / <p>This&nbsp; paper&nbsp; shows&nbsp; distribution,&nbsp; dynamic&nbsp; and&nbsp; pollinator&nbsp; diversity Hymenoptera&nbsp; -&nbsp; Apiformes&nbsp; (Anthophila)&nbsp; and Diptera (Syrphidae)&nbsp; in semi-natural&nbsp; habitats&nbsp; and&nbsp; in&nbsp; sunflower&nbsp; crops&nbsp; in&nbsp; Vojvodina&nbsp; agroecosystems.&nbsp; Around&nbsp; each&nbsp; of&nbsp; 16&nbsp; selected&nbsp; steppe&nbsp; fragments,&nbsp; habitat types&nbsp; were&nbsp; mapped&nbsp; to&nbsp; test&nbsp; how&nbsp; do&nbsp; landscape&nbsp; structure&nbsp; affects pollinator&nbsp; diversity&nbsp; and&nbsp; abundance&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats&nbsp; and&nbsp; in sunflower&nbsp; crops.&nbsp; Based&nbsp; on&nbsp; the&nbsp; results&nbsp; obtained&nbsp; by&nbsp; mapping,&nbsp; seven study sites with high % of sunflower like mass flowering crops, and eight&nbsp; study&nbsp; sites&nbsp; with&nbsp; no&nbsp; or&nbsp; low&nbsp; %&nbsp; of&nbsp; mass&nbsp; flowering&nbsp; crops&nbsp; are selected. In total, there were 114 species from 6 families&nbsp; from order Hymenoptera-Apiformes:&nbsp; Andrenidae,&nbsp; Apidae,&nbsp; Colletidae, Halictidae, Melittidae and Megachilidae, and 11 species from order Diptera&nbsp; (Syrphidae).&nbsp; Insects&nbsp; from&nbsp; families:&nbsp; Andrenidae,&nbsp; Apidae, Colletidae&nbsp; and&nbsp; Halictidae&nbsp; were&nbsp; distributed&nbsp; on&nbsp; all&nbsp; study&nbsp; sites,&nbsp; while insects&nbsp; from&nbsp; family&nbsp; Megachilidae&nbsp; were&nbsp; distributed&nbsp; almost&nbsp; on&nbsp; all study&nbsp; sites&nbsp; (15&nbsp; sites).&nbsp; At&nbsp; least&nbsp; only&nbsp; on&nbsp; five&nbsp; study&nbsp; sites&nbsp; were distributed insects from family: Colletidae and Melittidae. Hoverflies were distributed on all study sites.&nbsp; Kruskal-Wallis H test shows that an&nbsp; all&nbsp; three&nbsp; seasons&nbsp; (2011.,&nbsp; 2012.,&nbsp; 2013.)&nbsp; in&nbsp; semi&nbsp; natural&nbsp; habitats wild bees species were most abundant, followed by hoverfly species, and bumblebee species at the end. Same test&nbsp; shows that&nbsp; in all three seasons in semi natural habitats individuals of hoverflies were more abundant than individuals of honey bees, wild bees&nbsp; and individuals of&nbsp; bumblebees,&nbsp; which&nbsp; were&nbsp; least&nbsp; abundant.&nbsp; Friedman&nbsp; test&nbsp; shows differences in densities of pollinator through the seasons, and these results&nbsp; shows&nbsp; increasing&nbsp; in&nbsp; Apis&nbsp; mellifera&nbsp; densities&nbsp; and&nbsp; decline&nbsp; of wild bees densities through seasons. Man-Whitney&nbsp; U-test&nbsp; shows&nbsp; that&nbsp; there&nbsp; were&nbsp; more&nbsp; species&nbsp; and individuals of bumble bees in semi-natural habitats which landscapes are without&nbsp; or low % of sunflower. Same test shows that there were more&nbsp; individuals&nbsp; of&nbsp; honey&nbsp; bees&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; which landscapes&nbsp; have&nbsp; high&nbsp; %&nbsp; of&nbsp; sunflower.&nbsp; Wilcoxon&nbsp; signed-rank&nbsp; test shows&nbsp; that&nbsp; in&nbsp; semi-natural&nbsp; habitats&nbsp; species&nbsp; and&nbsp; individuals&nbsp; of bumblebees&nbsp; were&nbsp; more&nbsp; abundant&nbsp; after&nbsp; blooming&nbsp; sunflower,&nbsp; while species&nbsp; and&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; as&nbsp; well&nbsp; as&nbsp; individuals&nbsp; of hoverflies and&nbsp; <em>Apis mellifera</em>&nbsp; were&nbsp; more abundant during blooming sunflower.&nbsp; Linear mixed-effect model shows that with increase of % of&nbsp; sunflower&nbsp; in&nbsp; landscape&nbsp; number&nbsp; of&nbsp; individuals&nbsp; of&nbsp; wild&nbsp; bees&nbsp; and species and individuals of bumblebees decreasing, and individuals of hoverflies increasing. With an increase of % of semi natural habitats and&nbsp; increase&nbsp; of&nbsp; flower&nbsp; cover,&nbsp; abundance&nbsp; and&nbsp; species&nbsp; of&nbsp; hoverflies<br />increases.</p>

No description available.

Ce travail a pour objectif de tester des solutions viables et durables pour la phytoremédiation de sols contaminés en éléments traces. Il inclut à la fois des données sur l'évaluation initiale et résiduelle des risques (biomonitoring) et sur des solutions de phytomanagement à long terme utilisant des plantes et microorganismes associés, en particulier la phytoextraction aidée couplant l’épuisement du pool labile de contaminants du sol, la production de matière première végétale et la restauration de services écosystémiques. La phytotoxicité du Cu, le rôle améliorant des amendements organiques et minéraux et la tolérance des plantes ont été examinés utilisant des essais biologiques ainsi qu’une technique de dilution du sol. L'utilité d’une lignée de mutant de tournesol (Helianthus annuus) et d’une lignée parental de tabac (Nicotiana tabacum) pour le biomonitoring de sols contaminés en Cu a été investiguée. Les paramètres biochimiques qui sont en relation avec le statut antioxidant des plantes et leurs réponses moléculaires à l’excès de Cu ont en général montré une plus grande sensibilité que les traits morphologiques. Le tabac est plus tolérant au Cu que le tournesol. Des bactéries endophytes issues de différentes sources, notamment des graines d’une population métallicole d’une graminée (Agrostis capillaris) peuvent stimuler la croissance du tournesol et du tabac aux expositions en Cu modérément en excès. Pour ces plantes annuelles, accumulatrices secondaires du Cu et à phénotype d’exclusion, l'augmentation de la capacité de phytoextraction de Cu par les parties aériennes s’effectue principalement par l’accroissement de la biomasse aérienne, plutôt que par celui de sa concentration en Cu. Par conséquent, une attention a été prêtée aux pratiques agricoles dans les essais en parcelles sur site. Plusieurs options d’amélioration ont été examinées in situ: l'application d’amendements du sol, l'utilisation de lignées de mutants et de variants somaclonaux, la rotation de cultures et des cultivars, la bioaugmentation, la fertilisation, l’irrigation, etc. Deux lignées de mutants et des cultivars commerciaux de tournesol ainsi qu’une lignée parentale de tabac ont montré un fort potentiel pour la phytoextraction du Cu, accompagné d’une production significative de graines et/ou autre biomasse valorisable. Les solutions de restauration écologique basées sur la phytoextraction, utilisant des plantes annuelles accumulatrices secondaires de Cu permettraient (1) la décontamination progressive des sols contaminés en Cu au cours des rotations culturales, (2) un retour financier lié à la valorisation de la biomasse végétale, et (3) la restauration de services écosystémiques. / This work aimed at assessing sustainable phytoremediation options for trace element-contaminated soils. It includes both the assessment of initial and residual risks (biomonitoring) and long-term sustainable decontamination options using plants and associated microbes, especially aided phytoextraction with the secondary purposes of producing plant-based feedstock and restoring ecosystem services. Copper phytotoxicity, the improving role of soil conditioners, and plant tolerance were tested using a bioassay as well as a fading technique. The usefulness of a mutant line of sunflower (Helianthus annuus) and a motherline of tobacco (Nicotiana tabacum) for the biomonitoring of Cu-contaminated soils was investigated. Biochemical parameters in relation to antioxidant status of plants and molecular responses to Cu excess generally showed a greater sensitivity than morphologic ones. Tobacco has a higher Cu tolerance than sunflower. Endophytic bacteria from various sources, notably from the seeds of metallicolous populations of grasses (Agrostis capillaris) can promote the growth of sunflower and tobacco exposed to Cu excess. For annual Cu-secondary accumulator plants with an excluder phenotype, increase in shoot Cu removal occurred primarily through increase in shoot biomass, rather than in shoot Cu concentration. Therefore, attention in field trials was paid to agricultural practices. Various improving options were tested in situ: application of soil amendments, the use of mutant lines and somaclonal variation, cultivars and crop rotation, bioaugmentation, fertilization, irrigation, etc. Two mutant lines and some commercial cultivars of sunflower as well as the motherline of tobacco showed a high potential for Cu phytoextraction as well as for plant-based feedstock. Ecological restoration options for Cu-contaminated soils based on phytoextraction using annual Cu-secondary accumulator plants with a high shoot biomass would (1) result in the progressive decontamination of Cu-contaminated soils during crop rotations, (2) provide a financial return through biomass valorization, and (3) promote ecosystem services.

The dissertation thesis deals with the analysis of prospective environmentally compatible electrical insulating fluids for electrical engineering in relation to their chemical structure. The thesis starts with the overview of the current state of the art and of the latest trends in the use of synthetic and biodegradable natural oils. In the experimental part were studied these oils: mineral oils, rapeseed oil, sunflower oils, soybean oil, methyl oleate, peanut oil, MCT oil, castor oil and other. Dielectric properties were measured using LRC meter Agilent 4980A including dielectric liquid test fixture Agilent 16452A and also by the Novocontrol Alpha-A analyzer. Electrical properties are presented in the frequency range 10 mHz – 1 MHz range in the temperature interval 253 K to 363 K. The work goes on with the study of the suitability of individual oils for lower temperature, including the impact of the chemical structure and formulation on electrical properties.

This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.