978 resultados para Foraging behavior
Resumo:
In the first week of a chick life, broilers are very sensitive to different conditions outside their thermoneutral zone. Thus, the goal of this study was to evaluate the behaviors and productive responses of broilers subjected to conditions of thermal comfort or challenge at different intensities (27, 30, 33 and 36ºC) and durations (1, 2, 3 and 4 days starting on the second day of life). In the experiment, ten minutes of images from each hour of each treatment were analyzed to evaluate the key behaviors of the birds. Similar behavior at different dry-bulb air temperatures were identified by using Ward's method of cluster analysis. These behaviors were grouped by dendograms in which the similarity of these data was qualified. Feed intake, water intake and body mass of these animals were evaluated and used to support the observed behaviors. Thus, a similar huddling behavior was observed in the birds from the 2nd to the 5th day of life subjected to 27ºC and 30ºC, while at 30ºC and 33ºC the behavior of accessing feeders and drinkers was also similar. Chicks subjected to 33ºC presented the best performance, and at 30 and 36ºC showed intermediate development.
Resumo:
Alkoholberusning r en av de starkaste riskfaktorerna fr aggressivt beteende. Alla individer blir dock inte aggressiva under alkoholberusning. I sin doktorsavhandling underskte Johansson ifall individens genetiska uppsttning kan frklara skillnader i vem som reagerar p alkohol med kat aggressivt beteende och ilska och vem som inte gr det. Resultaten visade att individer som r brare av en viss variant av genen som kodar fr oxytocinets receptorer r i hgre grad bengna att uppvisa aggressivt beteende n andra nr de r alkoholberusade. Sambandet mellan alkohol och ilska pverkades ven av individens genetiska uppsttning av tv oxytocinreceptorgenvarianter, vilket antyder att dessa genvarianter ven pverkar bengenheten att knna ilska under alkoholberusning. Oxytocinet, som fungerar bde som ett hormon och en neurotransmittor, har i tidigare studier visats ha breda effekter p sociala frmgor hos mnniskan, ssom frmga till igenknnande av andras knslouttryck. Resultaten r de frsta att hos mnniskan experimentellt pvisa att vissa individer beter sig mer aggressivt n andra nr de r berusade, beroende p individens genetiska uppsttning. Det r viktigt att komma ihg att genens effekt i det hr fallet inte r av en sdan natur att den direkt och ofrnkomligen orsakar aggressivt beteende. Med andra ord r det orimligt i detta fall att tnka att en individ skulle tillmtas ansvarsfrihet i exempelvis ett vldsbrottml om hon br p en viss variant av denna gen, ppekar Johansson. Oxytocinreceptorgenens effekter analyserades i tv olika urval. I ett experimentellt upplgg indelades 116 mn slumpssigt i tv grupper: en grupp som tilldelades alkoholhaltiga drycker, och en kontrollgrupp som tilldelades alkoholfria drycker. Aggressivt beteende mttes med ett laboratorietest dr frskspersonerna fick bestraffa en fiktiv motspelare genom att spela upp motbjudande ljud fr denne. Resultaten replikerades i ett populationsbaserat urval av mn och kvinnor (n = 3755) vilka besvarat frgor om deras aggressiva beteenden, ilska, och alkoholanvndning.
Resumo:
PURPOSE:Pregnant women have a 2-3 fold higher probability of developing restless legs syndrome (RLS – sleep-related movement disorders) than general population. This study aims to evaluate the behavior and locomotion of rats during pregnancy in order to verify if part of these animals exhibit some RLS-like features.METHODS:We used 14 female 80-day-old Wistar rats that weighed between 200 and 250 g. The rats were distributed into control (CTRL) and pregnant (PN) groups. After a baseline evaluation of their behavior and locomotor activity in an open-field environment, the PN group was inducted into pregnancy, and their behavior and locomotor activity were evaluated on days 3, 10 and 19 of pregnancy and in the post-lactation period in parallel with the CTRL group. The serum iron and transferrin levels in the CTRL and PN groups were analyzed in blood collected after euthanasia by decapitation.RESULTS:There were no significant differences in the total ambulation, grooming events, fecal boli or urine pools between the CTRL and PN groups. However, the PN group exhibited fewer rearing events, increased grooming time and reduced immobilization time than the CTRL group (ANOVA, p<0.05).CONCLUSION:These results suggest that pregnant rats show behavioral and locomotor alterations similar to those observed in animal models of RLS, demonstrating to be a possible animal model of this sleep disorder.
Resumo:
This study aims to open up some typical models of organizational buying behavior. As the cloud computing and cloud services seem to be the todays hype, the study seeks to further facilitate the understanding of organizational buying behavior regarding cloud services by interviewing a decision maker of this field in the purchasers side and also for comparison a cloud service providers representative from the vendors side.
Resumo:
Alcohol consumption during pregnancy can potentially affect the developing fetus in devastating ways, leading to a range of physical, neurological, and behavioral alterations most accurately termed Fetal Alcohol Spectrum Disorders (FASD). Despite the fact that it is a preventable disorder, prenatal alcohol exposure today constitutes a leading cause of intellectual disability in the Western world. In Western countries where prevalence studies have been performed the rates of FASD exceed, for example, autism spectrum disorders, Downs syndrome and cerebral palsy. In addition to the direct effects of alcohol, children and adolescents with FASD are often exposed to a double burden in life, as their neurological sequelae are accompanied by adverse living surroundings exposing them to further environmental risk. However, children with FASD today remain remarkably underdiagnosed by the health care system. This thesis forms part of a larger multinational research project, The Collaborative Initiative on Fetal Alcohol Spectrum Disorders (the CIFASD), initiated by the National Institute of Alcohol Abuse and Alcoholism (NIAAA) in the U.S.A. The general aim of the present thesis was to examine a cohort of children and adolescents growing up with fetal alcohol-related damage in Finland. The thesis consists of five studies with a broad focus on diagnosis, cognition, behavior, adaptation and brain metabolic alterations in children and adolescents with FASD. The participants consisted of four different groups: one group with histories of prenatal exposure to alcohol, the FASD group; one IQ matched contrast group mostly consisting of children with specific learning disorder (SLD); and two typically-developing control groups (CON1 and CON2). Participants were identified through medical records, random sampling from the Finnish national population registry and email alerts to students. Importantly, the participants in the present studies comprise a group of very carefully clinically characterized children with FASD as the studies were performed in close collaboration with leading experts in the field (Prof. Edward Riley and Prof. Sarah Mattson, Center for Behavioral Teratology, San Diego State University, U.S.A; Prof. Eugene Hoyme, Sanford School of Medicine, University of South Dakota, U.S.A.). In the present thesis, the revised Institute of Medicine diagnostic criteria for FASD were tested on a Finnish population and found to be a reliable tool for differentiating among the subgroups of FASD. A weighted dysmorphology scoring system proved to be a valuable additional adjunct in quantification of growth deficits and dysmorphic features in children with FASD (Study 1). The purpose of Study 2 was to clarify the relationship between alcohol-related dysmorphic features and general cognitive capacity. Results showed a significant correlation between dysmorphic features and cognitive capacity, suggesting that children with more severe growth deficiency and dysmorphic features have more cognitive limitations. This association was, however, only moderate, indicating that physical markers and cognitive capacity not always go hand in hand in individuals with FASD. Behavioral problems in the FASD group proved substantial compared to the typically developing control group. In Study 3 risk and protective factors associated with behavioral problems in the FASD group were explored further focusing on diagnostic and environmental factors. Two groups with elevated risks for behavioral problems emerged: length of time spent in residential care and a low dysmorphology score proved to be the most pervasive risk factor for behavioral problems. The results underscore the clinical importance of appropriate services and care for less visibly alcohol affected children and highlight the need to attend to children with FASD being raised in institutions. With their background of early biological and psychological impairment compounded with less opportunity for a close and continuous caregiver relationship, such children seem to run an especially great risk of adverse life outcomes. Study 4 focused on adaptive abilities such as communication, daily living skills and social skills, in other words skills that are important for gradually enabling an independent life, maintain social relationships and allow the individual to become integrated into society. The results showed that adaptive abilities of children and adolescents growing up with FASD were significantly compromised compared to both typically-developing peers and IQ-matched children with SLD. Clearly different adaptive profiles were revealed where the FASD group performed worse than the SLD group, who in turn performed worse than the CON1 group. Importantly, the SLD group outperformed the FASD group on adaptive behavior in spite of comparable cognitive levels. This is the first study to compare adaptive abilities in a group of children and adolescents with FASD relative to both a contrast group of IQ-matched children with SLD and to a group of typically-developing peers. Finally, in Study 5, through magnetic resonance spectroscopic imaging (MRS) evidence of longstanding neurochemical alterations were observed in adolescents and young adults with FASD related to alcohol exposure in utero 14-20 years earlier. Neurochemical alterations were seen in several brain areas: in frontal and parietal cortices, corpus callosum, thalamus and frontal white matter areas as well as in the cerebellar dentate nucleus. The findings are compatible with neuropsychological findings in FASD. Glial cells seemed to be more affected than neurons. In conclusion, more societal efforts and resources should be focused on recognizing and diagnosing FASD, and supporting subgroups with elevated risk of poor outcome. Without adequate intervention children and adolescents with FASD run a great risk of marginalization and social maladjustment, costly not only to society but also to the lives of the many young people with FASD.
Resumo:
In order to encourage children and adolescents to defend and support their victimized peers, it is important to identify factors that either maximize or minimize the probability that students will engage in such behaviors. This thesis is composed of four studies designed to elucidate how a variety of factors work in conjunction to explain why some children defend their victimized classmates, whereas others remain passive or reinforce the bully. The conceptual framework of this thesis is drawn from several theoretical considerations, including social cognitive learning theory, the expectancy-value framework as well as the literature emphasizing the importance of empathy in motivating behaviors. Also the child-by-environment perspective and the socialecological perspective influenced this research. Accordingly, several intra- and interpersonal characteristics (e.g., social cognitions, empathy, and social status) as well as group-level factors (e.g., norms) that may either enhance or reduce the probability that students defend their victimized peers are investigated. In Studies I and II, the focus is on social cognitions, and special attention is paid to take into account the domain-specificity of cognition-behavior processes. Self-efficacy for defending is still an interest of study III, but the role of affective empathy on defending is also investigated. Also social status variables (preference and perceived popularity) are evaluated as possible moderators of links between intrapersonal factors and defending. In Study IV, the focus is expanded further by concentrating on characteristics of childrens proximal environments (i.e., classroom). Bullying norms and collective perceptions (i.e., connectedness among the students and the teachers ability to deal with bullying situations) are examined. Data are drawn from two research projects: the Kaarina Cohort Study (consisting of fourth and eighth graders) and the randomized controlled trial (RCT) evaluating the effects of the KiVa antibullying program (consisting of third to fifth graders). The results of the thesis suggest that defending the victims of bullying is influenced by a variety of individual level motivational characteristics, such as social cognitions and affective empathy. Also, both perceived popularity and social preference play a role in defending, and the findings support the conceptualization that behavior results from the interplay between the characteristics of an individual child and their social-relational environment. Classroom context further influences students defending behavior. Thus, antibullying efforts targeting peer bystanders should aim to influence intra- and interpersonal characteristics of children and adolescents as well as their social environment.
Resumo:
Ett mne som vckt intresse bde inom industrin och forskningen r hantering av kundfrhllanden (CRM, eng. Customer Relationship Management), dvs. en kundorienterad affrsstrategi dr fretagen frn att ha varit produktorienterade vljer att bli mera kundcentrerade. Numera kan kundernas beteende och aktiviteter ltt registreras och sparas med hjlp av integrerade affrssystem (ERP, eng. Enterprise Resource Planning) och datalager (DW, eng. Data Warehousing). Kunder med olika preferenser och kpbeteende skapar sin egen signatur i synnerhet via anvndningen av kundkort, vilket mjliggr mngsidig modellering av kundernas kpbeteende. Fr att f en versikt av kundernas kpbeteende och deras lnsamhet, anvnds ofta kundsegmentering som en metod fr att indela kunderna i grupper utgende frn deras likheter. De mest anvnda metoderna fr kundsegmentering r analytiska modeller konstruerade fr en viss tidsperiod. Dessa modeller beaktar inte att kundernas beteende kan frndras med tiden. I freliggande avhandling skapas en holistisk versikt av kundernas karaktr och kpbeteende som utver de konventionella segmenteringsmodellerna ven beaktar dynamiken i kpbeteendet. Dynamiken i en kundsegmenteringsmodell innefattar frndringar i segmentens struktur och innehll, samt frndringen av individuella kunders tillhrighet i ett segment (s.k migrationsanalyser). Vardera frndringen modelleras, analyseras och exemplifieras med visuella datautvinningstekniker, frmst med sjlvorganiserande kartor (SOM, eng. Self-Organizing Maps) och sjlvorganiserande tidskartor (SOTM), en vidareutveckling av SOM. Visualiseringen anteciperas underltta tolkningen av identifierade mnster och gra processen med kunskapsverfring mellan den som gr analysen och beslutsfattaren smidigare. Asiakkuudenhallinta (CRM) eli organisaation muuttaminen tuotepainotteisesta asiakaskeskeiseksi on herttnyt mielenkiintoa niin yliopisto- kuin yritysmaailmassakin. Asiakkaiden kyttytymist ja toimintaa pystytn nykyn helposti tallentamaan ja varastoimaan toiminnanohjausjrjestelmien ja tietovarastojen avulla; asiakkaat jttvt jatkuvasti piirteistn ja ostokyttytymisestn kertovia tietojlki, joita voidaan analysoida. On tavallista, ett asiakkaat poikkeavat toisistaan eri tavoin, ja heidn mieltymyksens kuten mys ostokyttytymisens saattavat olla hyvinkin erilaisia. Asiakaskyttytymisen monimuotoisuuteen ja tuottavuuteen paneuduttaessa kytetnkin laajalti asiakassegmentointia eli asiakkaiden jakamista ryhmiin samankaltaisuuden perusteella. Perinteiset asiakassegmentoinnin ratkaisut ovat usein yksittisi analyyttisia malleja, jotka on tehty tietyn aikajakson perusteella. Tmn vuoksi ne monesti jttvt huomioimatta sen, ett asiakkaiden kyttytyminen saattaa ajan kuluessa muuttua. Tss vitskirjassa pyritnkin tarjoamaan holistinen kuva asiakkaiden ominaisuuksista ja ostokyttytymisest tarkastelemalla kahta muutosvoimaa tiettyyn aikarajaukseen perustuvien perinteisten segmentointimallien lisksi. Nm kaksi asiakassegmentointimallin dynamiikkaa ovat muutokset segmenttien rakenteessa ja muutokset yksittisten asiakkaiden kuulumisessa ryhmn. Ensimmist dynamiikkaa lhestytn ajallisen asiakassegmentoinnin avulla, jossa visualisoidaan ajan kuluessa tapahtuvat muutokset segmenttien rakenteissa ja profiileissa. Toista dynamiikkaa taas lhestytn kytten nk. segmenttisiirtymien analyysia, jossa visuaalisin keinoin tunnistetaan samantyyppisesti segmentist toiseen vaihtavat asiakkaat. Visualisoinnin tehtvn on tukea havaittujen kaavojen tulkitsemista sek helpottaa tiedonsiirtoa analysoijan ja pttjien vlill. Visuaalisia tiedonlouhintamenetelmi, kuten itseorganisoivia karttoja ja niiden laajennuksia, kytetn osoittamaan niden menetelmien hydyllisyys sek asiakkuudenhallinnassa yleisesti ett erityisesti asiakassegmentoinnissa.
Resumo:
Some material aspects such as grain size, purity and anisotropy exert an important influence on surface quality, especially in single point diamond turning. The aim of this paper is to present and discuss some critical factors that can limit the accuracy of ultraprecision machining of non-ferrous metals and to identify the effects of them on the cutting mechanism with single point diamond tools. This will be carried out through observations of machined surfaces and chips produced using optical and scanning electron microscopy. Solutions to reduce the influence of some of these limiting factors related with the mechanism of generation of mirror-like surfaces will be discussed.
Resumo:
In nuclear reactors, the occurrence of critical heat flux leads to fuel rod overheating with clad fusion and radioactive products leakage. To predict the effects of such phenomenon, experiments are performed using electrically heated rods to simulate operational and accidental conditions of nuclear fuel rods. In the present work, it is performed a theoretical analysis of the drying and rewetting front propagation during a critical heat flux experiment, starting with the application of an electrical power step from steady state condition. After the occurrence of critical heat flux, the drying front propagation is predicted. After a few seconds, a power cut is considered and the rewetting front behavior is analytically observed. Studies performed with various values of coolant mass flow rate show that this variable has more influence on the drying front velocity than on the rewetting one.
Effect of particle morphology on the mechanical and thermo-mechanical behavior of polymer composites
Resumo:
Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites were prepared by incorporating glass particles of different morphologies on poly(aryl sulfones) matrices. Particles with aspect ratios equal to 1, 2.5 and 10 were used. The prepared composites were characterized using electron microscopy and thermal analysis. Mechanical properties of the composites were evaluated using a four-point bending test. The thermo-mechanical behavior of the obtained composites was also investigated. The results showed that the morphology of the particles alter significantly the mechanical properties of composites. Particles with larger values of aspect ratio led to large elastic modulus but low levels of strain at failure. This result was explained by modeling the thermo-mechanical behavior of the composites using a viscoelastic model. Parameters of the model, obtained from a Cole-Cole type of plot, demonstrated that interactions at the polymer-reinforcing agent interface were higher for composites with large aspect ratio particles. Higher levels of interactions at interfaces can lead to higher degrees of stress transfer and, consequently, to composites with large elastic modulus, as experimentally observed.
Resumo:
Larsmo-jasjn i sterbotten skapades genom invallningar p 1960-talet pga. industrins behov av stvatten. Sedan dess har vattenomrdet drabbats av terkommande frsurning och fiskdd, och invallningen har ofta beskyllts fr problemen. Avhandlingen undersker syrabelastningen i omrdet; bl.a. hur markanvndning, hydrologi och klimatfrndringen pverkar belastningen. Konsekvenserna undersks med fiskyngel som bioindikator, och olika miljmetoder testas och diskuteras. kad kunskap om frsurningen hjlper oss att tillmpa effektiva miljmetoder och f frbttrad vattenkvalitet i framtiden. Den primra orsaken till den frsmrade vattenkvaliteten under de senaste 40 ren r intensiv dikning av svavelrika sediment. Detta leder till oxidering av svavlet till svavelsyra och uppkomst av sura sulfatjordar. Syran lser upp mngder med toxiska metaller som spolas ut i vattendragen. Underskningen visar att tiotusentals ton svavelsyra tillsammans med stora mngder metaller rinner till Larsmo-jasjn per r frn sura sulfatjordar. arna bidrar med mest belastning, men den sammanlagda belastningen frn de otaliga dikena och bckarna r ovntat stor. Andra potentiella kllor till frsurningen, t.ex. muddringar och humussyror, berknas vara obetydliga. Syra- och metallbelastningen varierar kraftigt med hydrologin, dvs. strst belastning sker under vr- och hstflden. En eventuell klimatfrndring kan ndra p avrinningsmnstret och orsaka mera belastning vintertid. Den rligt terkommande syra- och metallbelastningen kan ofta hindra lakens frkning, vilket kan ha strre lngtgende konsekvenser fr fiskpopulationerna n de relativt sllsynta stora surchockerna med synlig fiskdd. Fr att frebygga skador p vattendragen br man undvika att drnera svavelrika sedimenten. P redan existerande sura sulfatjordar visade sig kontroll av grundvattennivn kunna mjliggra en effektiverad markanvndning utan mrkbart kade miljkonsekvenser.
Resumo:
The Bradyrhizobium japonicun strains SEMIA 5073, SEMIA 5074, SEMIA 5079 and SEMIA 5080 were grown in vitro using Vincent medium combined with different rates of the herbicides imazaquin (0, 0.04, 0.12, 0.24, 0.36 mg a.i. g-1), clomazone (0, 0.4, 0.8, 1.6 and 3.2 mg a.i. g-1) and sulfentrazone (0, 0.2, 0.4, 0.8 and 1.6 mg a.i. g-1) to evaluate the strains tolerance to herbicides. The three herbicides drastically inhibited all the rhizobium strains tested, showing a significant decrease of the CFU number as a function of herbicide rates. The rhizobium strains presented a differentiated tolerance to the herbicides. The herbicide rates that reduced 50% (I50) of the growth or survival of the rhizobium strains were below the recommended sprayed rates for weed control in the soybean crop, for all the three herbicides studied; however, sulfentrazone I50 was smaller than imazaquin and clomazone I50.
Resumo:
The purpose of this masters thesis was to investigate the effects which benefits obtained from reading a newspaper and using its website have on behavioral outcomes such as word-of-mouth behavior and willingness to pay. Several other antecedents of willingness to pay have been used as the control variables. However, their interrelations havent been hypothesized. The empirical part focused on a case company Finnish regional newspaper. Empirical research has been conducted using a quantitative method and data was collected via online survey placed on newspapers website during 2010. 1001 responses have been collected. The results showed that benefits obtained both from traditional printed newspaper and from online one have positive effects on the word-of-mouth about this newspaper and its website. However, it has been revealed that benefits obtained from reading the newspaper dont have effect on the willingness to pay for this newspaper. Additionally, only interpersonal and convenience benefits obtained from using the newspapers website influence on the willingness to pay for it. Finally, willingness to pay for the bundle of printed newspaper and its website access is affected positively only by the information/learning benefits obtained from reading the newspaper and by the interpersonal benefits obtained from using the newspapers website.
Resumo:
This thesis investigates the influence of cultural distance on entrepreneurs negotiation behaviour. For this purpose, Turku was chosen as the unit of analysis due to the exponential demographic change experienced during the last two decades that has derived in a more diversified local environment. The research aim set for this study was to identify to what extent entrepreneurs face cultural distance, how cultural distance influences the entrepreneurs negotiation behaviour and how can it be addressed in order to turn dissimilarities into opportunities. This study presented the relation and apparent dichotomy of cultural distance and global culture, including the component of diversity. The impact of cultural distance in the entrepreneurial mindset and its consequent effect in negotiation behaviour was presented too. Addressing questions about the way individuals perceive, behave and interact allowed the use of interviews for this qualitative research study. In the empirical part of this study it was found that negotiation behaviour differed in terms of how congenial entrepreneurs felt when managing cultural distance, encompassing their performance. It was also acknowledged that after time and effort, some of the personal traits were enhanced while others reduced, allowing for more flexibility and adaptation. Furthermore, depending on the level of trust and shared interests, entrepreneurs determined their attitudinal approach, being adaptive or reactive subject to situational aspects. Additionally, it was found that the acquisition of cultural savvy not necessarily conveyed to more creativity. This experiential learning capability led to the proposition of new ways of behaviour. Likewise, it was proposed that growing cultural intelligence bridge distances, reducing mistrusts and misunderstandings. The capability of building more collaborative relationships allows entrepreneurs to see cultural distance as a cultural perspective instead of as a threat. Therefore it was recommended to focus on proximity rather than distance to better identify and exploit untapped opportunities and better perform when negotiating in whichever cultural conditions.