995 research outputs found

    Polarization vision: Behavioral studies in tethered flying desert locusts, Schistocerca gregaria

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    Behavioral studies with tethered flying desert locusts show orientation on linearly polarized light. The dorsal rim area is the responsible part of the compound eye for mediating this behavior. Polarization information is exclusively sent from the dorsal rim area via the anterior optic tract to the central complex of the locust brain

    Jyväskylän ammattikorkeakoulun opiskelijoiden psykoaktiivisten aineiden käyttö

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    Opinnäytetyön aihe kumpusi tekijöiden kiinnostuksesta tutkia oman ammattikorkeakoulunsa opiskelijoiden psykoaktiivisten aineiden (rajauksena alkoholi, kannabis ja tupakka) käyttöä, sillä Jyväskylän ammattikorkeakoulusta ei löydy vastaavaa aikaisemmin tehtyä tutkimusta. Aihe esiteltiin Jyväskylän ammattikorkeakoulun opiskeluterveydenhuollon edustajille, jotka osoittivat kiinnostuksensa aihetta kohtaan. Opinnäytetyön yhteistyökumppanit ovatkin Jyväskylän ammattikorkeakoulu sekä – opiskeluterveydenhuolto. Opinnäytetyön tavoitteena oli saada Jyväskylän ammattikorkeakoulun opiskeluterveydenhuollolle ajantasaista tietoa Jyväskylän ammattikorkeakoulun opiskelijoiden psykoaktiivisten aineiden (alkoholi, tupakka, kannabis) käytöstä. Opinnäytetyön tarkoituksena oli tuoda esille koulukohtainen käsitys siitä, minkälaista Jyväskylän ammattikorkeakoulun opiskelijoiden psykoaktiivisten aineiden käyttö on tällä hetkellä. Opinnäytetyön tutkimuskysymykset ovat: ”Mikä on psykoaktiivisten aineiden käytön tilanne Jyväskylän ammattikorkeakoulun opiskelijoiden keskuudessa tällä hetkellä?” sekä ”Miksi Jyväskylän ammattikorkeakoulun opiskelijat käyttävät psykoaktiivisia aineita?”. Työssä haluttiin myös tarkastella sitä, vaikuttavatko opiskelu, opiskeltava koulutusohjelma, ikä, sukupuoli tai perhe opiskelijoiden psykoaktiivisten aineiden käyttöön. Tutkimusta varten koottiin kyselylomake, joka lähetettiin Jyväskylän ammattikorkeakoulun opiskelijoille sähköpostitse. Tutkimustulokset analysoitiin käyttämällä kvalitatiivista ja kvantitatiivista tutkimusmenetelmää sekä SPSS-ohjelmaa. Työ aloitettiin syksyllä 2012 teoriatiedon keruulla. Tutkimuslupahakemus työtä varten saatiin maaliskuussa 2013. Tutkimus suoritettiin huhtikuussa 2013 Digium Enterprise-ohjelmistoa hyödyntäen. Tulokset analysoitiin ja raportti koottiin lopulliseen muotoonsa huhti-toukokuun 2013 aikana.Theme for the thesis was selected due to the interest of the authors’ towards usage of psychoactive substances (including alcohol, cannabis and tobacco) among the students of their own university of applied sciences since there are no similar studies done before. The subject was presented to the representatives of JAMK student health services, who showed positive interest. The collaborators of the thesis are JAMK University of Applied Sciences and City of Jyväskylä Social and Health Services. The goal of the thesis was to bring JAMK student health services current data of usage of psychoactive substances (alcohol, tobacco, cannabis) of students in JAMK University of Applied Sciences. The purpose of the thesis was to create an image of the usage of psychoactive substances of students of JAMK University of Applied Sciences at present. The questionnaire for the thesis were the following: “What is the situation of the usage of psychoactive substances among the students of JAMK University of Applied Sciences?” and “Why do the students of JAMK University of Applied Sciences use psychoactive substances?”. The thesis aimed to reflect if studies, degree programme, age, sex or family background in the usage of psychoactive substances. A questionnaire was developed which was sent to the students of JAMK University of Applied Sciences via email. The results of the study were analyzed through qualitative and quantitative research methods, and with SPSS programme. The work began in autumn 2012 with collection of theoretical research information. A study permit application for the thesis was granted in March 2013. The study carried out in April 2013 with Digium Enterprise-software. The results were analyzed and a report was assembled in its final form during April and May of 2013

    Predator mixes and the conspicuousness of aposematic signals

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    Conspicuous warning signals of unprofitable prey are a defense against visually hunting predators. They work because predators learn to associate unprofitability with bright coloration and because strong signals are detectable and memorable. However, many species that can be considered defended are not very conspicuous; they have weak warning signals. This phenomenon has previously been ignored in models and experiments. In addition, there is significant within- and among-species variation among predators in their search behavior, in their visual, cognitive, and learning abilities, and in their resistance to defenses. In this article we explore the effects of variable predators on models that combine positive frequency-dependent, frequency-independent, and negative frequency-dependent predation and show that weak signaling of aposematic species can evolve if predators vary in their tendency to attack defended prey.<br /

    Long-Term Prophylactic Antibiotic Treatment : Effects on Survival, Immunocompetence and Reproduction Success of Parasemia plantaginis (Lepidoptera: Erebidae)

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    Hundreds of insect species are nowadays reared under laboratory conditions. Rearing of insects always implicates the risk of diseases, among which microbial infections are the most frequent and difficult problems. Although there are effective prophylactic treatments, the side effects of applied antibiotics are not well understood. We examined the effect of prophylactic antibiotic treatment on the overwintering success of wood tiger moth (Parasemia plantaginis) larvae, and the postdiapause effect on their life-history traits. Four weeks before hibernation larvae were treated with a widely used antibiotic (fumagillin). We monitored moths' survival and life-history traits during the following 10 mo, and compared them to those of untreated control larvae. Prophylactic antibiotic treatment had no effect on survival but we show effects on some life-history traits by decreasing the developmental time of treated larvae. However, we also revealed relevant negative effects, as antibiotic treated individuals show a decreased number of laid eggs and also furthermore a suppressed immunocompetence. These results implicate, that a prophylactic medication can also lead to negative effects on life-history traits and reproductive success, which should be seriously taken in consideration when applying a prophylactic treatment to laboratory reared insect populations.Peer reviewe

    The complete mitochondrial genome of the wood tiger moth (Arctia plantaginis) and phylogenetic analyses within Arctiinae

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    We report the assembly and annotation of the complete mitochondrial genome of the warningly-coloured wood tiger moth (Arctia plantaginis) and investigate its phylogenetic position within Arctiinae. The A.plantaginis mitogenome is 15,479 bp long with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNA genes, and an A + T-rich region (D-loop). The phylogenetic analyses based on 13 protein-coding genes showed A.plantaginis clustering within a clade of species with white wings and yellow or red bodies. This result can be useful in understanding the evolution of coloration in Arctiid moths.Peer reviewe

    Social transmission of avoidance among predators facilitates the spread of novel prey

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    Warning signals are an effective defence strategy for aposematic prey, but only if they are recognized by potential predators. If predators must eat prey to associate novel warning signals with unpalatability, how can aposematic prey ever evolve? Using experiments with great tits (Parus major) as predators, we show that social transmission enhances the acquisition of avoidance by a predator population. Observing another predator’s disgust towards tasting one novel conspicuous prey item led to fewer aposematic than cryptic prey being eaten for the predator population to learn. Despite reduced personal encounters with unpalatable prey, avoidance persisted and increased over subsequent trials. Next we use a mathematical model to show that social transmission can shift the evolutionary trajectory of prey populations from fixation of crypsis to fixation of aposematism more easily than was previously thought. Therefore, social information use by predators has the potential to have evolutionary consequences across ecological communities.Peer reviewe

    Between-group competition and human cooperation

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    A distinctive feature of human behaviour is the widespread occurrence of cooperation among unrelated individuals. Explaining the maintenance of costly within-group cooperation is a challenge because the incentive to free ride on the efforts of other group members is expected to lead to decay of cooperation. However, the costs of cooperation can be diminished or overcome when there is competition at a higher level of organizational hierarchy. Here we show that competition between groups resolves the paradigmatic ‘public goods’ social dilemma and increases within-group cooperation and overall productivity. Further, group competition intensifies the moral emotions of anger and guilt associated with violations of the cooperative norm. The results suggest an important role for group conflict in the evolution of human cooperation and moral emotions

    Variation in Hsp70 Levels after Cold Shock: Signs of Evolutionary Responses to Thermal Selection among Leptinotarsa decemlineata Populations

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    Individuals of widely spread species are expected to show local adaption in temperature tolerance as they encounter a range of thermal conditions. We tracked thermal adaptations of the Colorado potato beetle (Leptinotarsa decemlineata) that invaded Europe within the last 100 years. It has occupied various conditions although, like the majority of invasive species, it lost a measurable amount of neutral genetic variation due to bottleneck effect when it invaded Europe. We exposed diapausing beetles originated from three different latitudes (54°N, 59°N, 60°N) to cold shock (−5°C, 1.5 hrs) in order to test if beetles from the northern populations express differential levels of cold-induced and constitutive Hsp70 compared to the beetles from milder temperature regime. The level of cold-induced Hsp70 was lowest in the northernmost beetle populations while the level of constitutive Hsp70 did not differ with the population. Moreover, the southernmost beetles were more plastic in their response to cold shock than the northernmost beetles. These results suggest that physiological adaptation, like the synthesis of Hsp70, can evolve very quickly

    De novo transcriptome assembly and its annotation for the aposematic wood tiger moth (Parasemia plantaginis)

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    In this paper we report the public availability of transcriptome resources for the aposematic wood tiger moth (Parasemia plantaginis). A comprehensive assembly methods, quality statistics, and annotation are provided. This reference transcriptome may serve as a useful resource for investigating functional gene activity in aposematic Lepidopteran species. All data is freely available at the European Nucleotide Archive (http://www.ebi.ac.uk/ena) under study accession number: PRJEB14172.Peer reviewe

    Coinfection outcome in an opportunistic pathogen depends on the inter-strain interactions

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    Background: In nature, organisms are commonly coinfected by two or more parasite strains, which has been shown to influence disease virulence. Yet, the effects of coinfections of environmental opportunistic pathogens on disease outcome are still poorly known, although as host-generalists they are highly likely to participate in coinfections. We asked whether coinfection with conspecific opportunistic strains leads to changes in virulence, and if these changes are associated with bacterial growth or interference competition. We infected zebra fish (Danio rerio) with three geographically and/or temporally distant environmental opportunist Flavobacterium columnare strains in single and in coinfection. Growth of the strains was studied in single and in co-cultures in liquid medium, and interference competition (growth-inhibiting ability) on agar. Results: The individual strains differed in their virulence, growth and ability for interference competition. Number of coinfecting strains significantly influenced the virulence of infection, with three-strain coinfection differing from the two-strain and single infections. Differences in virulence seemed to associate with the identity of the coinfecting bacterial strains, and their pairwise interactions. This indicates that benefits of competitive ability (production of growth-inhibiting compounds) for virulence are highest when multiple strains co-occur, whereas the high virulence in coinfection may be independent from in vitro bacterial growth. Conclusions: Intraspecific competition can lead to plastic increase in virulence, likely caused by faster utilization of host resources stimulated by the competitive interactions between the strains. However, disease outcome depends both on the characteristics of individual strains and their interactions. Our results highlight the importance of strain interactions in disease dynamics in environments where various pathogen genotypes co-occur.peerReviewe
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