190 research outputs found
European Film Commissions as Transcultural Promoters and Mediators
Abstract
This article investigates transcultural communication taking film commissions as case study. Film commissions are non-profit organisations looking to attract audiovisual productions to their areas and supply these audiovisual productions with services free of charge. Although relatively recent and little studied, film commissions are spreading fast worldwide. Combining the political economy approach with the most recent production studies, the article contends that film commissions can stimulate transcultural phenomena on three levels. First, they act as intermediaries between the audiovisual production and the host area. Second, they encourage collaboration between different production cultures. Third, they incentivise brand-new collaboration between the audiovisual production and the tourist sector
Vertical Distrubution in the Water Column of Drifting Stream Macroinvertebrates
ABSTRACT We examined the macroinvertebrate composition and drift density in a Mediterranean lotic system, the Erro River (northwestern Italy). Drift density and composition were sampled for one year at three levels of the water column; temperature and flow velocity were also measured. We found that drift density was generally highest near the bottom. We also noticed that various taxa tended to drift at preferential levels of the water column, with 41.4 % of taxa mainly at the bottom level and 31.0 % mainly at the top. Drift density decreased with increasing water temperature. Both taxa richness and macroinvertebrate abundance in the drift were positively associated with natural riverbed richness and abundance
Mass fluctuation in breeding females, males, and helpers of the Florida scrub-jay Aphelocoma coerulescens
Much evidence suggests that birds actively regulate their body mass reserves relative to their energy needs. Energy requirements during reproduction may differ in relation to sex-specific behavioural roles or, in the case of cooperative breeders, breeders relative to helpers. We measured body mass of free-living Florida scrub-jays throughout the nesting season by training them to land on an electronic balance. Jays exhibited a pattern of diurnal linear mass gain, from morning to afternoon. Day-to-day mass fluctuations, defined as the difference between mass on two consecutive days, were small (>80% were within 2 g, less than 3% of the mass of an adult bird) for all classes of jays: female breeders, male breeders and prebreeding helpers. The jays, which live in subtropical south-central Florida, did not exhibit changes in day-to-day mass fluctuation relative to weather or climate variables or calendar date. Day-to-day mass fluctuations influenced mass fluctuation between the following third and fourth days. These changes were usually compensatory, indicating that jays are able to regulate their body mass on a short-term basis, despite strong differences in their roles in reproduction. During reproduction, jays have a relatively predictable and abundant food supply, thus the appropriate strategy may be to maintain a stable body mass that balances some energy reserves against maintaining a low body mass for efficient flight, as required during reproduction
Studio sull’impatto ambientale delle attività di maricoltura nel Golfo di Oristano
L’obiettivo del presente lavoro è stato di simulare la dispersione e il tempo di residenza delle sostanze organiche immesse nell’ambiente a seguito delle attività di acquacoltura all’interno del Golfo di Oristano (Sardegna, Italia). A questo scopo è stato implementato un modello numerico di circolazione, con moduli di dispersione e diffusione euleriana e lagrangiana. Il modello ha evidenziato il ruolo fondamentale della direzione e dell’intensità del vento sulla dispersione dei rifiuti organici. A parità d’intensità , la direzione del vento influenza in maniera decisiva la distanza alla quale i rifiuti organici vengono trasportati e depositati. In tutti gli scenari di vento, il mangime non consumato, indipendentemente dalla sua dimensione, si deposita in un’area direttamente sotto le gabbie ma con una distribuzione spaziale che dipende dalle correnti indotte. In tutti i casi, la materia organica disciolta si diluisce ed è trasportata al di fuori del golfo. Con i venti da Maestrale i rifiuti organici sono spinti verso, l’interno del golfo per poi uscirne in forma disciolta da sud. Negli scenari di Libeccio e Scirocco i rifiuti organici disciolti tendono a diluirsi ed essere trasportati al di fuori del golfo dalla parte nord. In tutti gli scenari, la capacità di ricambio delle acque interne al golfo risulta elevata, con la maggior parte delle sostanze organiche disciolte presenti in concentrazioni molto basse dopo dieci ore dalla loro produzione. Dal punto di vista del ricambio d’acqua e conseguentemente per la dispersone di agenti inquinanti, quasi tutti i 13 siti simulati, ad esclusione dei due in prossimità dei capi, hanno tempi di residenza idonei per il posizionamento delle gabbie. Sono comunque da preferire le regioni più a sud perché i tempi di transito sono più bassi creando un impatto minore. Infine considerando che il golfo è ricoperto quasi interamente da Posidonia, i siti meno impattanti sono quelli che si trovano su un fondale fangoso e in prossimità del fiume Tirso (Sito 3 e 4). L’utilizzo di modelli numerici ha permesso di portare a termine studi a priori (tempi di transito, zone di deposizione, dispersioni inquinanti) per la pianificazione della disposizione ottimale delle gabbie, avente come conseguenza una più proficua produzione (maggiore redditività ) e un minore impatto ambientale. Si può infine affermare che nonostante l’assenza di studi antecedenti al presente, le gabbie all’interno del Golfo di Oristano siano state posizionate correttamente, in una regione ottimale per produzione e impatto ambientale
Nymphal growth, life cycle, and feeding habits of Potamanthus luteus (Linnaeus, 1767) (Insecta: Ephemeroptera) in the Bormida River, Northwestern Italy
Avian haemosporidian diversity on Sardinia: a first general assessment for the Insular Mediterranean
The Western Palearctic is one of the most investigated regions for avian haemosporidian parasites (Haemoproteus, Plasmodium and Leucocytozoon), yet geographic gaps in our regional knowledge remain. Here, we report the first haemosporidian screening of the breeding birds from Sardinia (the second-largest Mediterranean Island and a biodiversity hotspot), and the first for the insular Mediterranean in general. We examined the occurrence of haemosporidians by amplifying their mtDNA cytb gene in 217 breeding birds, belonging to 32 species. The total prevalence of infected birds was 55.3%, and of the 116 haplotypes recovered, 84 were novel. Despite the high number of novel lineages, phylogenetic analysis did not highlight Sardinia-specific clades; instead, some Sardinian lineages were more closely related to lineages previously recovered from continental Europe. Host-parasite network analysis indicated a specialized host-parasite community. Binomial generalized linear models (GLMs), performed at the community level, suggested an elevational effect on haemosporidian occurrence probability (negative for Haemoproteus; positive for Leucocytozoon) likely due to differences in the abundance of insect vectors at different elevations. Furthermore, a GLM revealed that sedentary birds showed a higher probability of being infected by novel haplotypes and long-distance migrants showed a lower probability of novel haplotype infection. We hypothesize that the high diversity of haemosporidians is linked to the isolation of breeding bird populations on Sardinia. This study adds to the growing knowledge on haemosporidians lineage diversity and distribution in insular environments and presents new insights on potential host-parasite associations
Effects of immune challenge and supernormal clutch production on egg quality in the red-legged partridge
ABSTRACT Background: Because maintenance of the immune system is thought to be resource-limited, trade-offs between immune function, body condition, and reproductive allocation are expected. Questions: Do females confronted with the simultaneous challenges of immune stimulation and supernormal egg production face a trade-off in terms of self-maintenance (body mass and blood parameters) and/or egg quality? Organism: Red-legged partridge, Alectoris rufa, a precocial bird species with a huge investment in eggs. Methods: We challenged the immune systems of females, before egg laying, with a novel antigen (Newcastle Disease virus vaccine, NDV). We also removed eggs as they were laid, so as to induce supernormal egg production. Conclusion: Compared with the other eggs, the last-laid eggs of hens with supernormal production were smaller, contained less yolk, had a lighter shell, and contained albumen with less lysozyme. However, the immune challenge had no effect on female condition or egg quality. Thus we found no evidence of a trade-off between immune function, body condition, and reproductive allocation
Reproduction of the Crag Martin (Ptyonoprogne rupestris) in relation to weather and colony size
From 1994 to 1999, we investigated how climatic conditions influence the laying dates and number of fledged young of the Crag Martin Ptyonoprogne rupestris, a poorly studied colonial martin that, like other aerial feeding birds, is supposed to be highly dependent on weather conditions. Laying dates were concentrated in May and the first half of June. The mean annual laying date differed significantly among years; however, probably because of the small absolute difference between early and late years, there was no influence on the clutch size nor on the number of fledged young. Mean clutch size was 4.4 ± 0.9 eggs, the hatching rate was 80.2 percent, and the average number of fledged young was 3.1 ± 1.9. Temperature and rainfall in the days before laying and during the incubation period did not influence the breeding success, while in the chick rearing period there was a negative relationship between temperature and number of fledged young. It is supposed that high temperature can negatively influence breeding success through the drying up of small rivers where parents find food (mainly aquatic insects). In our study area the Crag Martins nested solitarily or in small colonies (mean 3.5 ± 1.9 nests). Colony size did not influence the laying date, the clutch size or the number of successfully fledged young
Static and Dynamic Nonlinear Effects in Silicon Micro-Rings: Impact of Trap Assisted Shockley Read Hall Carrier Recombination
We present a new model for the analysis of non-linear effects in silicon micro-ring resonators based on the Shockley Read Hall model for carrier recombination in the silicon core. We can reproduce both measured ring transmission spectra varying input power and measured ring oscillating regimes. We report also pump-probe experiments for extracting the recovery dynamics of the effective loss and refractive index change
Separase prevents genomic instability by controlling replication fork speed
Proper chromosome segregation is crucial for preserving genomic integrity, and errors in this process cause chromosome mis-segregation, which may contribute to cancer development. Sister chromatid separation is triggered by Separase, an evolutionary conserved protease that cleaves the cohesin complex, allowing the dissolution of sister chromatid cohesion. Here we provide evidence that Separase participates in genomic stability maintenance by controlling replication fork speed. We found that Separase interacted with the replication licensing factors MCM2-7, and genome-wide data showed that Separase co-localized with MCM complex and cohesin. Unexpectedly, the depletion of Separase increased the fork velocity about 1.5-fold and caused a strong acetylation of cohesin's SMC3 subunit and altered checkpoint response. Notably, Separase silencing triggered genomic instability in both HeLa and human primary fibroblast cells. Our results show a novel mechanism for fork progression mediated by Separase and thus the basis for genomic instability associated with tumorigenesis
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