In situ measurements of the functional response of benthic suspension feeders exposed to cadmium and anti-fouling paint

In situ measurements of the functional response (feeding, respiration and excretion) of Mytilus edulis and Ciona intestinalis showed that the effects of 2.5 µg 1-1 tributyl tin and 100 µg 1-1 cadmium on an assemblage of the two species was lower than what could be predicted from the response of the two species separately. This is explained by biological interactions between the species and by the fact that the two species may react in different ways to the same disturbance. Thus, results from single species tests seem inadequate for making predictions of pollution effects in marine environments, and tests should instead be carried out at the community or ecosystem level

Cellular and Transcriptional Responses of Crassostrea gigas Hemocytes Exposed in Vitro to Brevetoxin (PbTx-2)

Hemocytes mediate a series of immune reactions essential for bivalve survival in the environment, however, the impact of harmful algal species and their associated phycotoxins upon bivalve immune system is under debate. To better understand the possible toxic effects of these toxins, Crassostrea gigas hemocytes were exposed to brevetoxin (PbTx-2). Hemocyte viability, monitored through the neutral red retention and MTT reduction assays, and apoptosis (Hoechst staining) remained unchanged during 12 h of exposure to PbTx-2 in concentrations up to 1000 µg/L. Despite cell viability and apoptosis remained stable, hemocytes incubated for 4 h with 1000 µg/L of PbTx-2 revealed higher expression levels of Hsp70 (p < 0.01) and CYP356A1 (p < 0.05) transcripts and a tendency to increase FABP expression, as evaluated by Real-Time quantitative PCR. The expression of other studied genes (BPI, IL-17, GSTO, EcSOD, Prx6, SOD and GPx) remained unchanged. The results suggest that the absence of cytotoxic effects of PbTx-2 in Crassostrea gigas hemocytes, even at high concentrations, allow early defense responses to be produced by activating protective mechanisms associated to detoxification (CYP356A1 and possibly FABP) and stress (Hsp70), but not to immune or to antioxidant (BPI, IL-17, EcSOD, Prx6, GPx and SOD) related genes

Geographic and seasonal patterns and limits on the adaptive response to temperature of European Mytilus spp. and Macoma balthica populations

Seasonal variations in seawater temperature require extensive metabolic acclimatization in cold-blooded organisms inhabiting the coastal waters of Europe. Given the energetic costs of acclimatization, differences in adaptive capacity to climatic conditions are to be expected among distinct populations of species that are distributed over a wide geographic range. We studied seasonal variations in the metabolic adjustments of two very common bivalve taxa at European scale. To this end we sampled 16 populations of Mytilus spp. and 10 Macoma balthica populations distributed from 39° to 69°N. The results from this large-scale comprehensive comparison demonstrated seasonal cycles in metabolic rates which were maximized during winter and springtime, and often reduced in the summer and autumn. Studying the sensitivity of metabolic rates to thermal variations, we found that a broad range of Q10 values occurred under relatively cold conditions. As habitat temperatures increased the range of Q10 narrowed, reaching a bottleneck in southern marginal populations during summer. For Mytilus spp., genetic-group-specific clines and limits on Q10 values were observed at temperatures corresponding to the maximum climatic conditions these geographic populations presently experience. Such specific limitations indicate differential thermal adaptation among these divergent groups. They may explain currently observed migrations in mussel distributions and invasions. Our results provide a practical framework for the thermal ecophysiology of bivalves, the assessment of environmental changes due to climate change and its impact on (and consequences for) aquaculture

Assessing the ecological impact of banana farms on water quality using aquatic macroinvertebrate community composition

In Costa Rica, considerable effort goes to conservation and protection of biodiversity, while at the same time agricultural pesticide use is among the highest in the world. Several protected areas, some being wetlands or marine reserves, are situated downstream large-scale banana farms, with an average of 57 pesticide applications per year. The banana industry is increasingly aware of the need to reduce their negative environmental impact, but few ecological field studies have been made to evaluate the efficiency of proposed mitigation strategies. This study compared the composition of benthic macroinvertebrate communities up- and downstream effluent water from banana farms in order to assess whether benthic invertebrate community structure can be used to detect environmental impact of banana farming, and thereby usable to assess improvements in management practises. Aquatic invertebrate samples were collected at 13 sites, using kick-net sampling, both up- and downstream banana farms in fast flowing streams in the Caribbean zone of Costa Rica. In total, 2888 invertebrate specimens were collected, belonging to 15 orders and 48 families or taxa. The change in community composition was analysed using multivariate statistics. Additionally, a biodiversity index and the Biological Monitoring Working Party (BMWP) score system was applied along with a number of community composition descriptors. Multivariate analyses indicated that surface waters immediately up- and downstream large-scale banana farms have different macroinvertebrate community compositions with the most evident differences being higher dominance by a single taxa and a much higher total abundance, mostly of that same taxon. Assessment of macroinvertebrate community composition thus appears to be a viable approach to detect negative impact from chemical-intensive agriculture and could become an effective means to monitor the efficacy of changes/proposed improvements in farming practises in Costa Rica and similar systems

Benchmarking och Utvärdering av Protokollet QUIC : En jämförelse av QUIC gentemot TCP

Since 2012 Google has been developing a new transport protocol called QUIC (Quick UDP Internet Connections). The purpose of the QUIC-protocol is to speed up the web and first of all produce lower response time on websites. This is interesting in several perspectives. First of all, this is good news for the common user that browse the web but also in an economical perspective. Studies show that quicker response time on websites attracts customers both short term and long term which is important in areas as e-commerce. On top of this the Internet alone (home computers, data centers etc.) stands for about 10% of the worlds electricity consumption and a quicker and more effective transport protocol could contribute to lower this number since a lot of data is transferred through the Internet each day. QUIC is already in use by many of Google´s servers and can be used when browsing the web in a chrome or Opera browser. This means that many people have already been in touch with QUIC unknowingly. This degree project focuses on the main problems which makes the QUICprotocol needed and compares QUIC to TCP. TCP has been the dominating transport protocol regarding reliable data transmission for decades and still is. In this project an environment for testing is implemented which makes it possible to compare response time for websites. Two different tests are made where different common internet conditions are simulated to see how these conditions effects the response time for each protocol. The tests have shown that QUIC and TCP are pretty much equal regarding response time when the delay is 100 ms or less and there is no packet loss. When the delay exceeds 100 ms have our tests shown that QUIC delivers quicker response times. The tests have also shown that QUIC is superior to TCP when data is transferred over a connection with packet losses. Although it can be questioned if we could have optimized our TCP-server to compete with QUIC in a better way.Google utvecklar sedan 2012 ett nytt pålitligt transportprotokoll, QUIC (Quick UDP Internet Connections). Syftet med detta är att göra webben ”snabbare” genom att bland annat minska svarstider för hemsidor. Detta är intressant ur en mängd perspektiv. Dels ur användarsynpunkt vid surf på webben men även ur ett rent ekonomiskt perspektiv då forskning visar att snabbare hemsidor lockar fler kunder både på kort och lång sikt vilket är intressant inom t ex. ehandel. Dessutom beräknas Internet stå för ungefär 10% av all elkonsumtion på hela planeten och ett snabbare och effektivare transportprotokoll kan förhoppningsvis bidra till att förbättra den siffran. QUIC används redan idag på flera av Googles egna servrar och uppkopplad mot Internet med webbläsaren Chrome eller Opera har användaren med stor sannolikhet redan stött på QUIC utan att veta om det. Detta arbete fokuserar på några av de problem som ligger som grund för vad QUIC är tänkt att förbättra och jämförs sedan med transportprotokollet TCP som har varit standardprotokollet för pålitlig dataöverföring i decennier. I arbetet upprättas en testmiljö som gör det möjligt att mäta svarstider på en webbklient för de olika protokollen vid olika simulerade förhållanden. Testerna går ut på att variera fördröjning och paketförluster för att se hur detta påverkar svarstiderna för respektive protokoll. Jämförelsen har resulterat i att QUIC och TCP är jämna i avseende på svarstider då inga paketförluster förekommer och fördröjningen är 100 ms eller lägre. Däremot när fördröjningen ökar till en nivå över den genomsnittliga fördröjningen överstiger 100 ms så pekar våra tester på att QUIC levererar snabbare svarstider. Dessutom har testerna visat att QUIC är överlägset TCP gällande svarstider då paketförluster förekommer. Det kan dock ifrågasättas huruvida vår TCP-server hade kunnat optimerats för hålla jämnare steg med QUIC

Fallet "Julia Caesar" : En fallstudie i hur spänningen mellan etablerade medier och alternativa medier tar sig uttryck

Internet tillhandahåller möjligheter för personer att publicera material och uttrycka känslor och åsikter utan att detta nödvändigtvis får konsekvenser i dessas straffrättsliga eller personliga liv, vilket lett till att de traditionella massmedierna inte längre har ensamrätt på opinionsbildning. Expressen publicerade under hösten år 2015 två artiklar i vilka den politiska skribenten som går under pseudonymen “Julia Caesar” namngavs. Genom att med en kritisk diskursanalys tillsammans med en retorisk analys studera de två Expressentexterna samt två texter skrivna av “Julia Caesar” i samband med Expressens publiceringar undersöks spänningen som uppstått mellan traditionella massmedier och alternativa medier som i takt med internets framväxt uppstått. Med hjälp av en fallstudie på “Julia Caesar” ville vi utreda relationen mellan alternativa medier och pressetik i en digital offentlighet och därigenom belysa större mediefenomen. Studiens teoretiska ramverk utgörs av teorier som rör anonymitet i en internetkontext samt två perspektiv på pressens roll i samhället. Studiens resultat visar att spänningarna mellan de etablerade respektive de alternativa medierna kan härledas till diskrepansen mellan de diskurser som de båda perspektiven ger uttryck för. Studien har vidare gjort det möjligt att urskilja vissa processer vilka normaliserar och befäster olika ideologiska budskap.

"I've been guilty of provocation but it's also just common sense marketing" : En studie av framställningen av genus och sexualitet inom reklamkampanjer i form av modefotografi

The purpose of this essay is to analyze the portrayal of gender and sexuality within fashion photography through a representational study of men and women in select Gucci fashion campaigns, Fall/Winter 1996 and Spring/Summer 2003. In doing so we also find specifics as to how artistic expression can manifest itself in the form of sexist advertising, this being through the sexualisation of fashion photography. The study commences with an introduction, explanation of its purpose, and a descriptive background of the Gucci fashion house and it’s then creative director Tom Ford, the material used and the public criticism it has received as sexist portrayal of women. The frame of the study takes form  through the theoretical approaches of gender theory and postfeminism focusing on the structural order of gender, gender roles and the use of feminine pleasure within advertising. Moreover we base our study on the concept of previous research on male pleasure alongside its female counterpart as well as the male concept of power. The analysis is performed through the methodical approach of Roland Barthes semiotic analysis including the use of denotation, connotation and myth as well as a multimodal analysis with a chosen set of semiotic resources; these are primarily focused on terms such as gaze, actions, positioning and camera angles. The material in question is divided into three pictures from each fashion house, totaling a set of six pictures each analyzed individually and ultimately discussed as a whole. Our findings result in a significantly more diverse interpretation than the single result expressed by public, governmental and editorial outcry; implying that the campaigns analysed can, through the use of semiotic and multimodal analysis carry significantly different meaning depending on what pictures are being analyzed as well how it is analyzed and interpreted. As such our results imply significantly less sexist and more conceptually diverse campaigns than what they, and Gucci under Tom Ford, have been known for. Moreover we found that the portrayal of fashion photography can be used as a tool for masking sexual violations through the pretext of artistic expression