Parental care is likely to evolve when benefits of care are greater than costs. Provision of parental care may buffer vulnerable offspring against unpredictable or hazardous environments permitting parents to breed in situations too hostile for unassisted juvenile survival. The nature of environmental unpredictability faced by parents and their offspring (e.g., availability of nutritional resources, breeding resources and/or the strength of competition) provides the ecological context in which costs and benefits of parental traits are defined. Therefore investigations about how the environment might shape parental traits ought not only to be conducted in the laboratory but also in a natural setting where unanticipated parameters may have profound effects on theoretical predictions. I conducted a series of manipulative experiments and observational studies in the laboratory and in the field using burying beetles, Nicrophorus vespilloides, to examine the effects of environmental variation on parental competitive ability, reproductive productivity, longevity and the expression of parental sex-role differences and alternative reproductive tactics. In these beetles a relative size advantage confers success in contests for scarce and vital breeding resources so a central prediction was that reproductive success would be positively correlated with body size. In contrast I found that reproductive performance was favoured over contest success when nutritional resources were delayed temporarily during a developmental window. Larger beetles do win contests for breeding-resources but the benefits of being large depend on the quality of the social environment experienced (i.e., the relative size of an opponent). In a naturalistic setting, smaller males avoided direct contests because they attracted proportionately more females and as a result their breeding associations were more often monogamous. This has potential benefits for females because they avoid female-female contests and brood parasitism. Variation in the nutritional environment provided by parents (the carcass size on which offspring are reared) directly influences body size creating a dynamism between the nutritional and social environments experienced by these beetles depending on their size, which has ramifications for their individual success and maintenance of alternative strategies in the population as a whole.

Orientadora: Eliana Gonçalves de Freitas / Banca: Silvia Maria Guimarães de Souza / Banca: Mateus José Rodrigues Paranhos da Costa / Banca: Silvia Mitiko Nishida / Banca: Rodrigo Egydio Barreto / Resumo: O comportamento reprodutivo dos teleósteos envolve a seleção de parceiros para acasalamento por meio de escolha da fêmea e da disputa entre machos. A disputa pode levar à formação de hierarquia de dominância, na qual os machos dominantes têm vantagem no acasalamento por impedir que outros machos se aproximem da fêmea. Por outro lado, é possível que a fêmea prefira machos com maior habilidade competitiva, antes da formação da hierarquia. Assim, para compreender os fatores que afetam a preferência da fêmea e se a presença da fêmea durante as competições fornece vantagem na luta dos machos, realizamos dois estudos com a tilápia-do-Nilo (Oreochromis niloticus). O primeiro estudo testou a preferência das fêmeas em relação à características indicadoras da habilidade competitiva dos machos, sem a interferência da competição entre eles. Para isso, uma fêmea foi submetida ao contato visual com dois machos isolados e a preferência por um deles foi testada. Posteriormente os mesmos machos interagiram e estabeleceram a dominância. O macho preferido não se tornou dominante. Assim, não houve associação entre a preferência da fêmea e características indicadoras da habilidade competitiva dos machos. No segundo estudo testamos o efeito do contato visual de um macho com uma fêmea sobre a disputa hierárquica entre machos, uma vez que as interações macho-fêmea podem modular a reprodução e agressão dos peixes. Para isso, um macho em contato visual prévio com uma fêmea interagiu com um macho previamente isolado até o estabelecimento hierárquico. Porém, o macho em contato visual com a fêmea não se tornou dominante nem emitiu maior freqüência de ataques ao oponente. A presença da fêmea causou aumento do Índice Gonadossomático do...(Resumo completo clicar acesso eletrônico abaixo) / Abstract: Reproductive behavior of many fish species is performed by sexual selection and mate choice based on male-male contests. In such situation, selection is related to individual male competitive ability. Competition causes a social hierarchy, and dominant fish takes advantages for mating by avoid subordinate approach of females. Thus, it is possible that female prefer highest competitive ability males. To understand factors affecting female preference and, whether female presence can affect reproductive male ability, we performed two studies with Nile tilapia (Oreochromis niloticus) to understand the factors involved in dominance and female choice. In the first study we tested the female preference for highest competitive ability male. For this purpose, a female was kept in a visual contact with two males and the preference was tested by recording time female spent near to them. After that, both males were put together to fight, and we analyzed the chosen male was the winner. There was no association between female choice and male competitive ability. In the second study, we tested the effect of male visual contact with female and we supposed this could guarantee victories in a contest. Thus, a male was kept seeing a female during 6 days, and after that it was paired with a 6-days isolated male until hierarchical settlement. Female presence causes gonadosomatic index rise, but did not enhance chances for male victory in the social contest. This means that males that have more developed gonads do not take advantage in social interactions. Finally, we concluded that: i) females showed preference for one male; ii) female preference is not associated to male competitive ability; iii) visual stimulated males by female (with better gonadal condition) have not advantage in the hierarchy settlement. / Doutor

Field pea (Pisum sativum L.) is an important grain legume in western Canada. Growers can, however, be reluctant to include pulse crops such as field pea in their rotation because they are poor competitors with weeds. This thesis research was conducted to determine whether competitive differences exist among semi-leafless field pea cultivars and to determine the mechanism(s) driving competitive differences. Cultivars included in the studies were chosen on the basis of varying seed size and vine length, which are traits known to confer competitive ability. Differences in competitive ability were identified among cultivars as yield loss ranged from 9% to 31% and 14% to 31% for model weed seed return. However, cultivars were inconsistent in their competitive ranking as cultivars typically performed well for one metric, but not both. None of the traits measured in this study correlated with competitive ability. The greenhouse research was unable to identify the mechanism responsible for these competitive differences. Focal pea plants generally responded to the presence of below-ground neighbours by allocating more resources to shoot production. Therefore, semi-leafless field pea cultivars exhibit differences in below-ground responses to neighbours and it may be useful to include this as part of the selection criteria in breeding programs.

Darbo tikslas - įvertinti bendrą konkurencinę situaciją Šiaulių miesto sporto klubų paslaugų rinkoje. Tyrimo uždaviniai - nustatyti pagrindinius sporto klubų konkurencingumą lemiančius veiksnius Šiaulių mieste, bei įvertinti sporto klubų konkurencinę padėtį rinkoje remiantis kokybiniais konkurencingumo rodikliais. Atlikus tyrimą paaiškėjo, kad sporto paslaugų sektoriuje veikiančių įmonių konkurencinę padėtį labiausiai įtakoja jų strateginė vieta, bei paslaugų kainos. Nepasitvirtino hipotezės, jog sporto klubų konkurencingumą lemia paslaugų skaičius, bei vykdoma reklama. Atlikus tyrime dalyvavusių organizacijų SSGG analizę, nustatyti kiekvienos iš jų sėkmės veiksniai bei trūkumai. Atsižvelgiant į juos, pateiktos bendro pobūdžio, bei atskirai kiekvienam sporto klubui skirtos rekomendacijos konkurencinės pozicijos gerinimui. / The aim of the work is to assess general competitive situation in sports clubs‘ market in Siauliai. The task of the research is to identify the main factors of sports clubs‘ competitive ability in Siauliai, and to assess their competitive position using qualitative indicators of competitive ability. The results of the research have indicated that the main factors of competitive ability of enterprises working in sports service market are their strategic place and prices of service. Hypotheses about the number of services and advertisement as a factor of sports clubs‘ competitive ability have not been proved. SWOT analysis defined the factors of success and drawbacks of each organization. General and individual recommendations on improvement of their competitive position have been submitted to the sports clubs.

Magistro baigiamajame darbe nagrinėjama UAB „Metalo prekyba“ konkurencinė aplinka Šiaulių mieste. Darbe išanalizuota konkurencijos samprata bei apibendrinti įmonių konkurencingumą lemiantys veiksniai, apžvelgtos bendros tendencijos, būdingos visai metalo ir jo gaminių gamybos pramonei Lietuvoje, įvertintos šios pramonės šakos perspektyvos bei galimybės. Praktinėje dalyje identifikuoti UAB „Metalo prekyba“ konkurentai Šiaulių mieste, atliktas jų profiliavimas bei išanalizuoti privalumai ir trūkumai. Remiantis vartotojų apklausa, nustatyti veiksniai, turintys didžiausią įtaką jų apsisprendimui, kurioje juoduoju metalu prekiaujančioje įmonėje Šiaulių mieste įsigyti reikiamos produkcijos. Pagal šiuos veiksnius bei atliktą konkurentų analizę nustatytos išskirtinės UAB „Metalo prekyba“ kompetencijos, įvertintos priežastys, dėl ko dalis vartotojų renkasi konkurentų įmones, bei pateiktos rekomendacijos UAB „Metalo prekyba“ konkurencinės pozicijos stiprinimui. / In the master’s final paper it was analysed competitive setting of JSC “Metalo prekyba” in Siauliai City. In the paper it was analysed concept of rivalry, summarized factors, predetermining competitive ability, reviewed general trends characteristic to the all metal and metalwork industry in Lithuania, assessed perspectives and opportunities of this industry. In the practical part it was identified rivals of JSC “Metalo prekyba” in Siauliai City, made their profile, analysed their advantages and disadvantages. Basing upon customer’s questioning, it was found out the factors most strongly influencing their determination about the company to select for purchase of ferrous metals in Siauliai City. Using these factors and analysis of the rivals, it was found out exceptional competences of JSC “Metalo prekyba” and the reasons, why the customers select other companies; then it was offered the recommendations for JSC “Metalo prekyba” to strengthen its competitive position.

Les protéagineux pourraient contribuer à réduire le déficit en protéines de l’Europe mais ils sont peu cultivés. L’association à une céréale permettrait de contourner leur variabilité de rendement et leur faible compétitivité vis-à-vis des adventices. Cette stratégie serait particulièrement pertinente pour le lupin blanc d’hiver, qui présente un fort potentiel de production de protéines mais un fort risque d’enherbement. Ce travail de thèse étudie en dynamique les interactions entre lupin, céréale et adventices afin de mettre en évidence les traits des espèces permettant d’accroitre leur complémentarité et la compétitivité vis-à-vis des adventices tout en sécurisant la productivité. L’étude d’un réseau de parcelles démontre que l’ajout de triticale permet d’augmenter la compétitivité vis-à-vis des adventices par rapport au lupin pur, d’obtenir un rendement supérieur et plus stable et de maintenir la production de protéines. Un essai en micro parcelles démontre le rôle majeur de la capture précoce d’azote (N) de la céréale pour accroitre la compétitivité vis-à-vis des adventices. Nous montrons que les rapports de compétition varient au cours du cycle et en fonction des espèces ou variétés ainsi que des conditions climatiques et influencent ainsi l’élaboration du rendement. De forts contrastes entre lupin et céréale pour des traits liés à l’acquisition précoce d’N sont décrits ainsi que leurs conséquences sur la mise en place de la complémentarité. Ce travail met en évidence que le choix d’espèces et de variétés aux traits complémentaires permet d’orienter les interactions entre lupin, céréale et adventices et ouvre des perspectives pour l’optimisation des performances. / Pea, faba bean and lupin could help to reduce the European protein deficit but they are not widely grown. Intercropping with a cereal can be seen as a way to circumvent their high yield variability and their low competitive ability against weeds. This strategy could be particularly relevant for winter white lupin, a crop that can produce high amounts of proteins but that is prone to high weed infestations. This doctoral thesis studies the dynamic interactions between lupin, cereal and weeds to highlight species traits that allow increasing their complementarity and their competitive ability against weeds while securing productivity. Results of a multisite study in agricultural fields demonstrate that adding triticale in lupin allows increasing competitive ability against weeds as well as yield and yield stability compared with sole-cropped lupin while maintaining protein production. A plot experiment highlights the key role of cereal early Nitrogen (N) uptake in the increase of competitive ability against weeds. Analysis of resource sharing shows that competitive relationships vary throughout the cropping cycle, depend on species or cultivars as well as climatic conditions and that they influence yield formation. Strong contrasts between lupin and a cereal for traits related to early soil N uptake and their consequences on complementarity are highlighted by the results of rhizotron experiments. This work emphasizes the role of species and cultivar choice to manage interactions between lupin, cereal and weeds and opens perspectives for the optimization of intercrop performances.

This dissertation deals with the competitive ability analysis on the basis of srategical methods. The analysis was applied in company Jednota, spotřební družstvo České Budějovice.

Weeds consist of the main type of direct interference with annual crops and are responsible for yield reduction. In this context , the objective of this research was to investigate the competitive ability of wheat cultivars with Italian ryegrass and radish weed plants. There were conducted works in the laboratory, field and in the greenhouse in 2012 and 2013. The article I includes laboratory and greenhouse experiments, where were evaluated the physiological quality of seeds of wheat cultivars and the effect of competition with weeds on germination and vigor of seeds, besides the maximum expression of their plant characteristics. In the article II there were evaluated coexistence among wheat cultivars BRS Guamirim, BRS 296, Fundacep Cristalino and Fundacep Raízes and Italian ryegrass and radish weeds. The articles III and IV show experiments developed in greenhouse, being the article III about to wheat ability in to compete with Italian ryegrass and radish weeds in a replacement series arrangement In the article IV is simulated the initial competition for light and the effects on the morphology of wheat plants, Italian ryegrass and radish. Thus, it is possible to conclude that the cultivar Fundacep Cristalino has the ability to maintain vigor of seeds when in competition throughout the cycle, besides to show morphological characteristics (plant height, leaf area, dry weight matter and high initial vigor), which confers superior competitive ability with weeds. The coexistence through the cycle with Italian ryegrass do not affect the yield of BRS Guamirim, BRS 296 , Fundacep Cristalino and Fundacep Raízes, however, the coexistence with radish affects significantly the PBA, ICA and yield components.Undependable of the competitor species, there are morphological alterations in the plants resulting from the initial competition for light. / As plantas daninhas consistem no principal tipo de interferência direta sobre os cultivos anuais e são responsáveis pela redução do rendimento de grãos. Neste contexto, o objetivo do presente trabalho de pesquisa foi investigar a habilidade competitiva de cultivares de trigo com as plantas daninhas de azevém e nabo. Foram realizados trabalhos em laboratório, em nível de campo e em casa de vegetação em 2012 e 2013. O artigo I contempla os trabalhos em laboratório e casa de vegetação, onde foi avaliada a qualidade fisiológica das sementes das cultivares de trigo e o efeito da competição com plantas daninhas sobre a germinação e o vigor de sementes, além da máxima expressão de suas características de planta. No artigo II, avaliou-se a convivência entre as cultivares de trigo BRS Guamirim, BRS 296, Fundacep Cristalino e Fundacep Raízes com as plantas daninhas de azevém e nabo em condição de campo. Os artigos III e IV abordam os trabalhos desenvolvidos em casa de vegetação, sendo o artigo III relativo à habilidade do trigo em competir com as plantas daninhas em esquema de série de substituição. No artigo IV, é simulada a competição inicial por radiação luminosa e os seus efeitos sobre características morfológicos de plantas de trigo, azevém e nabo. É possível concluir que a cultivar Fundacep Cristalino possui a habilidade de manter o vigor de sementes quando mantida em competição por todo o ciclo, além de apresentar características morfológicas (estatura, área foliar, massa seca e vigor inicial elevados), as quais lhe conferem maior habilidade competitiva com as plantas daninhas. A convivência durante todo o ciclo com o azevém, não afeta o rendimento de BRS Guamirim, BRS 296, Fundacep Cristalino e Fundacep Raízes, no entanto, a presença de nabo afeta significativamente a PBA, ICA e os componentes de rendimento. Independente da espécie competidora ocorrem alterações morfológicas nas plantas decorrentes da competição inicial por radiação luminosa.

Magistrantūros studijų baigiamasis darbas, 99 puslapiai, 31 paveikslas, 18 lentelių, 3 formulės, 56 literatūros šaltiniai, 4 priedai, lietuvių kalba. Tyrimo objektas – Šilalės rajono pieno ūkiai. Tyrimo dalykas – pieno ūkių veiklos strategijos. Tikslas – ištirti Šilalės rajono pieno ūkius ir nustatyti strategijos poveikį įvairaus dydžio ūkių konkurenciniams pranašumams. Uždaviniai: 1.Išanalizuoti šalies ir užsienio autorių mokslinę literatūrą strategijų rengimo ir konkurencinių pranašumų kūrimo klausimais. 2.Parengti pieno ūkių tyrimo metodiką. 3.Pateikti pieno ūkio strategijos vertinimo modelį. 4.Atlikti pieno ūkių apklausą Šilalės rajone. 5.Parengti pieno ūkio konkurencinių pranašumų kūrimo modelį. 6.Sukurti smulkaus, vidutinio ir stambaus pieno ūkio veiklos strategijas ir įvertinti jų įtaką ūkio konkurenciniams pranašumams. Tyrimo metodai - mokslinės literatūros loginė, aprašomoji ir palyginamoji analizė; anketinė apklausa bei pusiau struktūrizuota smulkaus, vidutinio ir stambaus pieno ūkių savininkų apklausa; ūkių stiprybių, silpnybių, galimybių ir grėsmių analizė; statistinis metodas (SPSS 13.0 programa); finansinė rizikos vertinimo analizė; grafinis modeliavimas. Apibendrinant mokslinės literatūros analizės, statistinės analizės bei empirinio tyrimo rezultatus galima teigti, jog veiklos strategijos įgyvendinimas pieno ūkyje padeda sukurti konkurencinį pranašumą lyginant su kitais tokio pat dydžio ūkiais. / The final work of master studies, 99 pages, 31 pictures, 18 tables, 3 formulas, 56 sources of literature, 4 supplements, Lithuanian. Research object – milk farms of Šilalė district. Research subject – milk farms action strategies. The purpose of work is to investigate milk farms of Šilalė district and to define strategy influence on different size farms competitive advantages. Research tasks: 1.To analyze national and foreign authors research literature of strategy arrangement and competitive advantages creation. 2.To prepare a technique for research of milk farm. 3.To propose milk farm strategy evaluation model. 4.To investigate milk farms owners in Šilalė district. 5.To frame milk farm competitive advantages creation model. 6.To create small, medium and large milk farm action strategies and to evaluate influence on farm competitive advantages. Research methods – scientific literature logic, monographic and comparable analysis; questionnaire survey and semi-structured interview of small, medium and large milk farm owners; the analysis of farms strengths, weaknesses, opportunities and threats; statistic method (SPSS 13.0 program); financial evaluation of risk; graphic modeling. In conclusion of scientific literature research, a statistic analysis and empiric research result the decision is that actions strategy in milk farm helps to create competitive advantage in comparison with other the same size farms.

Made available in DSpace on 2014-06-11T19:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-03Bitstream added on 2014-06-13T20:00:48Z : No. of bitstreams: 1 castro_als_dr_jabo.pdf: 338540 bytes, checksum: 2873a81aaff2ff97d28c2182b3255c16 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O comportamento reprodutivo dos teleósteos envolve a seleção de parceiros para acasalamento por meio de escolha da fêmea e da disputa entre machos. A disputa pode levar à formação de hierarquia de dominância, na qual os machos dominantes têm vantagem no acasalamento por impedir que outros machos se aproximem da fêmea. Por outro lado, é possível que a fêmea prefira machos com maior habilidade competitiva, antes da formação da hierarquia. Assim, para compreender os fatores que afetam a preferência da fêmea e se a presença da fêmea durante as competições fornece vantagem na luta dos machos, realizamos dois estudos com a tilápia-do-Nilo (Oreochromis niloticus). O primeiro estudo testou a preferência das fêmeas em relação à características indicadoras da habilidade competitiva dos machos, sem a interferência da competição entre eles. Para isso, uma fêmea foi submetida ao contato visual com dois machos isolados e a preferência por um deles foi testada. Posteriormente os mesmos machos interagiram e estabeleceram a dominância. O macho preferido não se tornou dominante. Assim, não houve associação entre a preferência da fêmea e características indicadoras da habilidade competitiva dos machos. No segundo estudo testamos o efeito do contato visual de um macho com uma fêmea sobre a disputa hierárquica entre machos, uma vez que as interações macho-fêmea podem modular a reprodução e agressão dos peixes. Para isso, um macho em contato visual prévio com uma fêmea interagiu com um macho previamente isolado até o estabelecimento hierárquico. Porém, o macho em contato visual com a fêmea não se tornou dominante nem emitiu maior freqüência de ataques ao oponente. A presença da fêmea causou aumento do Índice Gonadossomático do... / Reproductive behavior of many fish species is performed by sexual selection and mate choice based on male-male contests. In such situation, selection is related to individual male competitive ability. Competition causes a social hierarchy, and dominant fish takes advantages for mating by avoid subordinate approach of females. Thus, it is possible that female prefer highest competitive ability males. To understand factors affecting female preference and, whether female presence can affect reproductive male ability, we performed two studies with Nile tilapia (Oreochromis niloticus) to understand the factors involved in dominance and female choice. In the first study we tested the female preference for highest competitive ability male. For this purpose, a female was kept in a visual contact with two males and the preference was tested by recording time female spent near to them. After that, both males were put together to fight, and we analyzed the chosen male was the winner. There was no association between female choice and male competitive ability. In the second study, we tested the effect of male visual contact with female and we supposed this could guarantee victories in a contest. Thus, a male was kept seeing a female during 6 days, and after that it was paired with a 6-days isolated male until hierarchical settlement. Female presence causes gonadosomatic index rise, but did not enhance chances for male victory in the social contest. This means that males that have more developed gonads do not take advantage in social interactions. Finally, we concluded that: i) females showed preference for one male; ii) female preference is not associated to male competitive ability; iii) visual stimulated males by female (with better gonadal condition) have not advantage in the hierarchy settlement.