A population is never constant, but changes over time, and a connection is often found in population changes between predator and prey. A population increase in one can affect the other species positively or negatively. An increase in wood voles (Clehtrinomys glareolus) and field voles (Microtus agrestis) provides more food for the red fox (Vulpes vulpes), which in turn gets a better chance to reproduce. When the fox then increases in number, the vole decreases because the fox hunts and eats more food. Cycles are formed in the ups and downs of the populations which are followed. The purpose of this study is to see if a large vole population increases the fox's reproductive success in subsequent years and if a cycle interval with displacement between voles and foxes exists with a clear interval. Grimsö Research Station has contributed its data on the populations from the year 1973 until the year 2023. Lotka-Volterra's equations for predator-prey interactions were used and to see if a clear cycle interval between the populations existed. The result shows that the Lotka-Volterra equation does not give any clear shifts between the peaks and valleys of the populations as we thought before the test. In contrast, an autocorrelation analysis shows that the fox appears to follow the typical pattern of population cycles while the vole does not. A cross-correlation strengthens the result as the result is highest at a minimal time shift. A non-parametric correlation analysis finally shows that the correlation is strongly positive but not significant. / En population är aldrig konstant utan förändras över tid och ofta återfinns ett samband i populationsförändringar mellan predator och bytesdjur. En populationsökning hos den ena kan påverka den andra arten positivt eller negativt. En ökning av skogssork (Clehtrionomys glareolus) och åkersork (Microtus agrestis) ger mer mat åt rödräven (Vulpes vulpes) som i sin tur får bättre chans att reproducera sig. När räven då ökar i antal så minskar sorken eftersom räven jagar och äter mer mat. Det bildas då cykler i populationernas upp- och nedgångar som följs åt. Syftet med denna studie är att se om en stor sorkpopulation ökar rävens reproduktionsframgång efterföljande år samt om ett cykelintervall med förskjutning mellan sork och räv finns med tydligt intervall. Grimsö Forskningsstation har bidragit med data på populationerna från år 1973 fram till år 2023. Lotka-Volterras ekvationer för predator-prey interaktioner användes för att se om ett tydligt cykelintervall mellan populationerna fanns. Resultatet visar på att Lotka-Volterras ekvation inte ger några tydliga förskjutningar mellan populationernas toppar och dalar som vi trodde inför testet. Däremot visar en autokorrelationsanalys att räven ser ut att följa det typiska mönstret för populationscykler medan sorken inte gör det. En korskorrelation stärker resultatet då resultatet är högst vid minimal tidsförskjutning. En icke-parametrisk korrelationsanalys visar slutligen att korrelationen är starkt positiv men att den inte är signifikant.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2017-05-15T16:25:48Z No. of bitstreams: 1 Daniel Péricles Arruda.pdf: 7430022 bytes, checksum: 63856457278e532ccf76226df52f7d69 (MD5) / Made available in DSpace on 2017-05-15T16:25:48Z (GMT). No. of bitstreams: 1 Daniel Péricles Arruda.pdf: 7430022 bytes, checksum: 63856457278e532ccf76226df52f7d69 (MD5) Previous issue date: 2017-04-07 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This thesis aims to offer a critical reading about the interfaces between art and the social invisibility of the peripheral youth and offer a construction of knowledge in/to the area, mainly for Social Work. As far as art is concerned, in the critical perspective, we emphasize hip-hop culture as one of the most significant artistic modalities for the peripheral youth. For the accomplishment of this study, the bibliographic analysis on the subject was important, as well as the analysis of songs, poetry, films, documentaries and reports. This research is based on the Marxian legacy and the Marxist tradition, however, it does not deny important contributions from other theoretical matrices consistent with this approach. It is a qualitative study (with the presentation of quantitative data), through oral history, focusing on data collected from an interviewed group of individuals. For this, three people who belong to the hip-hop culture were interviewed. Two young people with an average age of 26.5 years - both living in the district of Brasilândia, in the North Zone of São Paulo / SP -, and one individual about 50 years old - who lives in São Bernardo do Campo / SP, whom is a well known figure in national and international scopes because of his militancy in the hip-hop culture. The interviews conducted with the two people who live in Brasilândia aimed to understand how they experience art in their life trajectory and their daily experience in the community where they live. The interview with the Sao Bernardo resident was focused on understanding his early life and his current practice with youth, through the hip-hop culture. The analytic course demonstrated that hip-hop culture presents significant elements for Social Work and that overcoming social invisibility through art is possible from the moment it is related to culture through daily relationships built from significant territorial sociabilities / Esta tese tem por finalidade propor uma leitura crítica acerca das interfaces entre a arte e a invisibilidade social da juventude periférica e oferecer uma construção de conhecimento na/para a área, principalmente para o Serviço Social. No que se refere à arte, na perspectiva crítica, enfatizamos a cultura hip-hop por ser uma das modalidades artísticas mais significativas para a juventude periférica. Para a realização deste estudo, foi importante a análise bibliográfica acerca do tema, bem como a análise de músicas, poesias, filmes, documentários e reportagens. Esta pesquisa tem por base o legado marxiano e a tradição marxista, porém, sem recusar importantes contribuições de outras matrizes teóricas condizentes com essa abordagem. Trata-se de um estudo qualitativo (com a apresentação de dados quantitativos), por meio da história oral, com foco nos depoimentos dos sujeitos entrevistados. Para isso, foram entrevistados três sujeitos que fazem parte da cultura hip-hop. Sendo: dois jovens com média de idade de 26,5 anos – ambos residentes no distrito de Brasilândia, Zona Norte de São Paulo/SP –, e um sujeito adulto – com cerca de 50 anos – que reside em São Bernardo do Campo/SP, porém é conhecido em âmbitos nacional e internacional em razão de sua militância na cultura hip-hop. As entrevistas realizadas com os jovens tiveram por objetivo compreender o modo como eles vivenciam a arte em sua trajetória de vida e em sua experiência cotidiana na comunidade onde moram. A entrevista realizada com o adulto teve por objetivo compreender a sua vivência enquanto jovem e a sua prática atual com a juventude, por meio da cultura hip-hop. O percurso analítico realizado demonstrou que a cultura hip-hop apresenta elementos significativos para o Serviço Social e que a superação da invisibilidade social por meio da arte é possível a partir do momento em que estiver relacionada à cultura por meio das relações cotidianas construídas a partir de sociabilidades territoriais significativas