403 research outputs found
Biologia reprodutiva do bagre ameaçado de extinção Genidens barbus (Lacépède, 1803) (Ariidae, Siluriformes), em ambiente estuarino no Sul do Brasil
A presente pesquisa descreve aspectos de biologia reprodutiva do bagre marinho ameaçado de extinção Genidens barbus (Lacépède, 1803), na região do estuário do rio Tramandaí, sul do Brasil, objetivando a compreensão acerca da biologia populacional da espécie e resiliência frente à pressão pesqueira, capaz de gerar de subsídios para o monitoramento e manejo pesqueiro da espécie na região. Os exemplares foram coletados a partir de capturas provenientes da pesca artesanal e e amostragem científica, de julho de 2020 a fevereiro de 2021. Seis fases reprodutivas foram atribuidas para cada sexo. Para as fêmeas, foi descoberta uma estrutura ainda não descrita em peixes, denominada de “zona de reserva”, e a análise gonadal macroscópica (baseada em características externas e internas dos ovários, incluindo o comprimento da zona de reserva), foi integrada com dados histológicos para a descrição das fases reprodutivas. Para os machos, as características macroscópicas dos testículos provaram não ser confiáveis para definir a maiorias das fases, e o método histológico foi essencial para a descrição das fases reprodutivas. A fecundidade absoluta variou de 104 a 272 oócitos vitelogênicos hidratados, e correlacionou-se significativa e positivamente com o comprimento e peso total dos peixes. A análise da distribuição de frequências dos diâmetros dos oócitos sugere que a espécie apresenta desova do tipo total, fecundidade determinada e desenvolvimento sincrônico dos oócitos. A temporada reprodutiva da espécie (excluindo o cuidado parental) na região foi definida com base nos Índices Gonadossomático e Hepatossomático, e frequência mensal de fases reprodutivas, iniciando em outubro e terminando em fevereiro. O IHS mostrou-se útil como um indicador do período prévio à temporada reprodutiva para ambos os sexos, com base em diferenças entre os meses reprodutivos e os que os antecedem, além de variar inversamente ao IGS. Os resultados encontrados podem contribuir para a revisão do período defeso da espécie na região, bem como dos tamanhos mínimos e máximos de captura, e na elaboração de planos de manejo pesqueiro sustentáveis, contribuindo para a conservação da espécie, e, consequentemente, com a manutenção da biodiversidade e desenvolvimento socioeconômico regional.This study describes reproductive biology aspects of the endangered white sea catfish Genidens barbus in the Tramandaí River Estuary region, southern Brazil, aiming the understanding of the species populational biology and resilience under fishery pressure, providing subsidies for the species local fishery monitoring and management. Fish were sampled from artisanal fisheries captures and scientific sampling, from July/2020 to February/2021. Six reproductive phases were assigned to each sex. For females, analysis of a new structure that was never described before for fish, named “reserve zone”, and macroscopic gonadal analysis (based on external and internal ovaries features, including reserve zone’s length) were integrated with histological data to phases description. For males, macroscopic features of the testis prove to be unreliable for most phases, and the histological method was essential for reproductive phases description. Absolute fecundity ranged from 104 to 272 hydrated vitellogenic oocytes and correlated significatively and positively with fish total length and weight. Analysis of frequency distribution of oocytes diameter suggests that the species is a total spawner, with group-synchrony spawn and determinate fecundity. The species spawning season (excluding parental care) in the region was defined as starting in October and ending in February, based on gonadal and liver indexes (GSI and HSI, respectively) and reproductive phases monthly frequencies. The HSI was useful as a pre-spawning indicator, showing differences between spawning months and the predecessors’ months for both sexes, and also varying inversely to GSI. The results found here can subsidize local sustainable fisheries management plans, supporting the species conservation and hence biodiversity maintenance and regional socioeconomic development
Policy approaches for placing parcel lockers in public space
This paper explores policy approaches for parcel lockers in public space. While last- mile delivery service providers primarily focus on the economic and customer service benefits of parcel lockers, securing approval from local governments to place lockers in public spaces requires justification of their public value. Our study identifies six factors that decisionmakers can consider when evaluating requests for parcel locker placement: carbon emissions, nuisances of the delivery vehicle, nuisances at a locker location, customer preferences, innovation, and the pull effect of parcel lockers. Through a series of semi-structured interviews and a workshop with public decisionmakers in cities across the Netherlands and Europe, we find that delivery vehicle nuisances and potential new nuisances at the locker location are important factors for decisionmakers at local government. Our study reveals two distinct approaches taken by local governments when facing requests for parcel locker placement in public spaces: reactive and proactive. Overall, this study contributes to the understanding of the policy perspective on parcel lockers in public spaces and provides insights for sustainable urban logistics planning
Beyond manifestos: Exploring how political campaigns use online advertisements to communicate policy information and pledges
Personality and susceptibility to political microtargeting: A comparison between a machine-learning and self-report approach
Based on recent technological advances, campaigners and political actors can use psychographic-based political marketing. Yet, empirical evidence about its effectiveness is still very limited. Based on self-congruity theory, a pre-registered experiment (N = 280) investigated the persuasion effects of personality-congruent political microtargeting on the attitude toward the political party and voting intentions of citizens. More precisely, the focus was on the thinking vs feeling personality dimension (MBTI), and it was tested whether this personality “interacts” with exposure to a matching advertising appeal: rational vs. emotional political ad. To do so, two different methodological approaches were used: 1) a machine learning approach; 2) a self-report survey measure of personality. Results revealed significant “congruence effects” between personality and ad appeal, and showed that perceived ad relevance was serving as the underlying mechanism (mediator). However, these results were only found when the self-report measure of personality was used. When the algorithmic approach was used, no significant results were found. These findings feed into timely societal, methodological, and theoretical contributions
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