Efeito de grupo versus produção de CO2 em operárias da formiga cortadeira Atta sexdens rubropilosa

Does the social life entail greater individual activity, and consequently, higher energy expenditure? To answer this question, we hypothesized that there is higher CO2 production, when we increase the size of the group of workers, and hence a higher energy cost to the individual when they are in groups. Thus, groups of 10, 20, 30, 40 and 50 workers were sealed in a hermetic chamber for 24 hours. Subsequently, we performed the measurements of the CO2 concentration in the containers respirometric. Unlike the expected CO2 production, and consequently the individual energy expenditure did not differ when we increase the size of the group of workers. Thus, we refuted the hypothesis that the group size leads to a higher cost individual energy, since the greater interaction between individuals. In conclusion, our study with Atta sexdens rubropilosa workers determined that the size of the group does not lead to higher energy costs individual and CO2 production, and therefore energy expenditure similar individual, independent of the group size.

Comportamento de poedeiras criadas a diferentes densidades e tamanhos de grupo em ambiente enriquecido

The objective of this work was to determine the behavioral differences among laying hens reared at different densities and group sizes, in an enriched environment. Isa Brownlaying hens with ages from 30 to 32-week-old, in small-sized and deformed pens, were used. Hens were raised during 28 days in bays with shavings bedding, perch and nest. Two group sizes were evaluated (6 and 12 fowls) and at two rearing densities (774 and 1,440 cm2 by fowl) in a factorial arrangement with three replicates. In fifteen-minute video footages, it was recorded the frequency and the expression period for the following behavior were recorded: feather scratching, sand bath, wing beating, drinking water, pecking, head scratching, earth scratching, eating, perching, leg stretching, pursuing, sitting, and nest visiting. The treatments and the interaction between them had significant effects. The six-hen group increased the frequency of behavior types that indicate fowl frustration, regardless of density. The group size is the most important factor for hen well-being.

Ecologia e comportamento do Cuxiú-Preto (Chiropotes Satanas) na paisagem fragmentada da Amazônia Oriental

Cuxiús são primatas frugívoros especializados na predação de sementes. O cuxiú-preto (Chiropotes satanas), atualmente ameaçado de extinção, é endêmico de uma área da Amazônia oriental brasileira bastante povoada e desmatada. O principal objetivo deste estudo foi pesquisar o comportamento e a ecologia de dois grupos de cuxiús-pretos vivendo sob diferentes graus de fragmentação de hábitat, de maneira a entender como parâmetros ecológicos nestes diferentes contextos influenciam estratégias comportamentais. Além disso, o estudo procurou identificar fatores que limitam a viabilidade a longo prazo do cuxiú-preto e coletar informações que possam contribuir com planos de manejo e conservação. O estudo foi realizado na margem direita do rio Tocantins, no reservatório de Tucuruí, Estado do Pará, Brasil (415'S, 4931'W). Dois grupos de cuxiús-pretos foram estudados: um (denominado T4) em um grande fragmento de floresta situado na margem do reservatório (1.300 ha, 39 indivíduos) e outro numa pequena ilha (19,4 ha, oito indivíduos) coberta por floresta. O comportamento dos dois grupos foi monitorado durante 12 meses (1.153 horas de observação) utilizando metodologias de amostragem por varredura e de todas as ocorrências por 4 a 5 dias consecutivos por mês por grupo. Além de coletar dados sobre seus orçamentos de atividades, todos os recursos alimentares utilizados foram documentados, os percursos diários anotados e as interações sociais intra e interespécies registradas. Transecções botânicas (10 x 100 ha) cobrindo um hectare no sítio T4 e 0,5 ha no sítio Ilha foram estabelecidas e uma subamostra de árvores (DAP ≥ 10 cm) e cipós (DAP ≥ 5 cm) foi marcada e medida para um inventário florístico e para a coleta de dados fenológicos que ocorreu em intervalos de 30 dias durante 14 meses. Os dois grupos diferiram em todos os aspectos de seu comportamento e ecologia. O tempo empregado em diferentes atividades variou significativamente entre eles. O deslocamento (35,4%) foi responsável pela maior proporção do orçamento de atividades anual do grupo T4, enquanto o grupo Ilha dedicou mais tempo para a alimentação (30,0%). Interações sociais foram responsáveis por uma proporção relativamente grande do orçamento de atividades dos dois grupos (T4 8,5%; Ilha 15,2%). Ao longo do periodo do estudo ambos os grupos consumiram um grande número de diferentes espécies vegetais (173 grupo T4; 132 grupo Ilha; 240 ambos) e suas dietas variaram significantemente tanto em termos de itens consumidos quanto em composição taxonômica, sendo que a dieta do grupo T4 foi mais diversa. Ambos os grupos despenderam a maior parte de seu tempo consumindo sementes (T4 54,0%; Ilha 59,9%), apesar de sua dieta também incluir outros itens tais como polpa de frutos (T4 25,0%; Ilha 13,7%), flores (T4 12,3%; Ilha 17,4%) e, em menor grau, medula de galhos e artrópodes. O grupo T4 utilizou uma área de 98,6 ha, enquanto os membros do grupo Ilha utilizaram 17,2 ha. O uso do espaço e o tamanho do percurso diário (T4 4025 m 994 m; Island 2807 m 289 m) variaram entre os grupos e estiveram ligados, no grupo T4, à variação no tamanho do grupo ao longo do ano resultante de seu sistema de organização social de fissão-fusão. Ao contrário, o grupo Ilha foi mais coeso. As diferenças na ecologia e comportamento dos dois grupos estiveram ligadas ás diferenças em seus respectivos hábitats. O tamanho dos sítios foi importante mas também o foi a variação na disponibilidade de alimentos determinada pela composição taxonômica da vegetação dos mesmos. Resultados do inventário florístico revelaram uma maior diversidade de espécies no sítio T4. No entanto importantes espécies alimentares estavam ausentes ou disponíveis em quantidades variáveis em ambos os sítios. Além do valor intrínseco do conhecimento sobre as características ecológicas do cuxiú-preto, o conhecimento detalhado acumulado neste estudo pode contribuir para a formulação de ações de conservação e planos de manejo, assim como para a identificação de fatores que limitam a viabilidade a longo prazo das populações remanescentes nas paisagens fragmentadas da Amazônia oriental.

Comportamento e dieta de Chiropotes albinasus (I. Geoffroy & Deville, 1848) - cuxiú-de-nariz-vermelho

Os cuxiús-de-nariz-vermelho são primatas neotropicais pouco conhecidos e encontramse na Lista de Espécies Ameaçadas da IUCN na categoria “Ameaçada de Extinção”. Este estudo foi desenvolvido com um grupo desta espécie de primatas na RPPN Cristalino, MT. Foi estudado o orçamento de atividades, uso de espaço e a ecologia alimentar do grupo, através do método de “Varredura Instantânea”. O grupo foi acompanhado durante 6 meses, incluindo 2 meses na estação chuvosa e 4 meses na estação seca. As categorias comportamentais Deslocamento, Alimentação e Parado foram responsáveis por 81,17% dos registros gerais de atividades. Os animais utilizaram com maior intensidade o estrato intermediário da floresta (entre 16 e 20 metros). A dieta do grupo foi preferencialmente frugívora (82,52%), mas também se alimentaram de invertebrados. Cerca de 18 famílias botânicas foram consumidas. Sendo os taxons Arrabidaea sp. e Brosimum latescens os mais comuns. Nos meses de seca houve um maior acréscimo de outros itens alimentares, como flores e invertebrados na dieta dos cuxiús. O tamanho do grupo variou entre 1 e 19 indivíduos ao longo do estudo, assim como a estrutura sexual que também variou bastante. Foi observado o cuidado parental por parte dos machos, além de interações agonísticas interespecíficas entre Ateles marginatus e Sapajus apella.

Notes on the feeding behaviour and swimming pattern of Manta alfredi (Chondrichthyes, Mobulidae) in the Red Sea

The feeding behaviour and the swimming pattern of the reef manta (Manta alfredi) are described based on video recordings conducted in Sudan, Red Sea, Indian Ocean, during June 2001. Three circular swimming patterns are described: horizontal circle pattern, inclined circle pattern and double circle pattern, related to feedings on zooplankton distributed in the water column. The observation of circle-like swimming patterns for reef manta rays in shallow waters expands our knowledge about M. alfredi and suggests that the distribution and abundance of zooplankton influence the occurrence and group size of this species in the studied area, as reported from other localities for Manta species.

Metodologia de atribuição dos escores visuais e estudo de associação genômica para os escores de conformação, precocidade e musculosidade em bovinos Nelore

Pós-graduação em Genética e Melhoramento Animal - FCAV

Estimating abundance of killer whales in the nearshore waters of the Gulf of Alaska and Aleutian Islands using line-transect sampling

Killer whale (Orcinus orca Linnaeus, 1758) abundance in the North Pacific is known only for a few populations for which extensive longitudinal data are available, with little quantitative data from more remote regions. Line-transect ship surveys were conducted in July and August of 2001–2003 in coastal waters of the western Gulf of Alaska and the Aleutian Islands. Conventional and Multiple Covariate Distance Sampling methods were used to estimate the abundance of different killer whale ecotypes, which were distinguished based upon morphological and genetic data. Abundance was calculated separately for two data sets that differed in the method by which killer whale group size data were obtained. Initial group size (IGS) data corresponded to estimates of group size at the time of first sighting, and post-encounter group size (PEGS) corresponded to estimates made after closely approaching sighted groups.

Cetaceans of Southeast Alaska: Distribution and Seasonal Occurrence

Aim To assess the distribution, group size, seasonal occurrence and annual trends of cetaceans. Location The study area included all major inland waters of Southeast Alaska. Methods Between 1991 and 2007, cetacean surveys were conducted by observers who kept a constant watch when the vessel was underway and recorded all cetaceans encountered. For each species, we examined distributional patterns, group size, seasonal occurrence and annual trends. Analysis of variance (anova F) was used to test for differences in group sizes between multiple means, and Student’s t-test was used to detect differences between pairwise means. Cetacean seasonal occurrence and annual trends were investigated using a generalized linear model framework. Results Humpback whales (Megaptera novaeangliae) were seen throughout the region, with numbers lowest in spring and highest in the fall. Fin whale (Balaenoptera physalus) and minke whale (Balaenoptera acutorostrata) distributions were more restricted than that reported for humpback whales, and the low number of sightings precluded evaluating seasonal trends. Three killer whale (Orcinus orca) eco-types were documented with distributions occurring throughout inland waters. Seasonal patterns were not detected or could not be evaluated for resident and offshore killer whales, respectively; however, the transient eco-type was more abundant in the summer. Dall’s porpoise (Phocoenoides dalli) were distributed throughout the region, with more sightings in spring and summer than in fall. Harbour porpoise (Phocoena phocoena) distribution was clumped, with concentrations occurring in the Icy Strait/Glacier Bay and Wrangell areas and with no evidence of seasonality. Pacific white-sided dolphins (Lagenorhynchus obliquidens) were observed only occasionally, with more sightings in the spring. For most species, group size varied on both an annual and seasonal basis. Main conclusions Seven cetacean species occupy the inland waters of Southeast Alaska, with distribution, group size, seasonal occurrence and annual trends varying by species. Future studies that compare spatial and temporal patterns with other features (e.g. oceanography, prey resources) may help in identifying the key factors that support the high density and biodiversity of cetaceans found in this region. An increased understanding of the region’s marine ecology is an essential step towards ensuring the long-term conservation of cetaceans in Southeast Alaska.

Flexible and conservative features of social systems in tufted capuchin monkeys: comparing the socioecology of Sapajus libidinosus and Sapajus nigritus

Socioecological models assume that primates adapt their social behavior to ecological conditions, and predict that food availability and distribution, predation risk and risk of infanticide by males affect patterns of social organization, social structure and mating system of primates. However, adaptability and variation of social behavior may be constrained by conservative adaptations and by phylogenetic inertia. The comparative study of closely related species can help to identify the relative contribution of ecological and of genetic determinants to primate social systems. We compared ecological features and social behavior of two species of the genus Sapajus, S. nigritus in Carlos Botelho State Park, an area of Atlantic Forest in Sao Paulo state, and S. libidinosus in Fazenda Boa Vista, a semi-arid habitat in Piaui state, Brazil. S. libidinosus perceived higher predation risk and fed on clumped, high quality, and usurpable resources (fruits) all year round, whereas S. nigritus perceived lower predation risk and relied on evenly distributed, low-quality food sources (leaves) during periods of fruit shortage. As predicted by socioecology models, S. libidinosus females were philopatric and established linear and stable dominance hierarchies, coalitions, and grooming relationships. S. nigritus females competed less often, and could transfer between groups, which might explain the lack of coalitions and grooming bonds among them. Both populations presented similar group size and composition and the same polygynous mating system. The species differed from each other in accordance with differences in the characteristics of their main food sources, as predicted by socioecological models, suggesting that phylogenetic inertia does not constrain social relationships established among female Sapajus. The similarity in mating systems indicates that this element of the social system is not affected by ecological variables and thus, is a more conservative behavioral feature of the genus Sapajus. Am. J. Primatol. 74:315331, 2012. (c) 2011 Wiley Periodicals, Inc.

Structural aspects of polyanion and hydrophobically modified polycation multilayers on hydrophilic or hydrophobic surfaces

Multilayer films of carboxymethylcellulose (CMC), a polyanion, and bromide salts of poly(4-vinylpyridine) quaternized with linear aliphatic chains of 2 (ethyl) and 5 (pentyl) carbon atoms, coded as QPVP-C2 and QPVP-C5, respectively, were fabricated by layer-by-layer (LbL) self-assembly onto Si/SiO2 wafers (hydrophilic substrate) or polystyrene, PS, films (hydrophobic substrate). The films were characterized by means of ex situ and in situ ellipsometry, atomic force microscopy (AFM), contact angle measurements and sum frequency generation vibrational spectroscopy (SFG). Antimicrobial tests were used to assess the exposure of pyridinium moieties to the aqueous medium. In situ ellipsometry indicated that for Si/SiO2 the chains were more expanded than the PS films and both substrates systems composed of QPVP-C5 were thicker than those with QPVP-C2. For dried layers, the alkyl side group size had a small effect on the thickness evolution, regardless of the substrate. At pH 2 the multilayers showed high resistance, evidencing that the build-up is driven not only by cooperative polymer-polymer ion pairing, but also by hydrophobic interactions between the alkyl side chains. The LbL films became irregular as the number of depositions increased. After the last deposition, the wettability of QPVP-C2 or QPVP-C5 terminated systems on the Si/SiO2 wafers and PS films were similar, except for QPVP-C2 on Si/SiO2 wafers. Unlike the morphology observed for LbL films on Si/SiO2 wafers, PS induced the formation of porous structures. SFG showed that in air the molecular orientation of pyridinium groups in multilayers with QPVP-C5 was stronger than in those containing QPVP-C2. The exposure of pyridinium moieties to the aqueous medium was more pronounced when the LbL were assembled on Si/SiO2 wafers.

A threshold hypothesis of institutional change: collective action in the Italian Alps during the 13th - 19th centuries.

This dissertation is about collective action issues in common property resources. Its focus is the “threshold hypothesis,” which posits the existence of a threshold in group size that drives the process of institutional change. This hypothesis is tested using a six-century dataset concerning the management of the commons by hundreds of communities in the Italian Alps. The analysis seeks to determine the group size threshold and the institutional changes that occur when groups cross this threshold. There are five main findings. First, the number of individuals in villages remained stable for six centuries, despite the population in the region tripling in the same period. Second, the longitudinal analysis of face-to-face assemblies and community size led to the empirical identification of a threshold size that triggered the transition from informal to more formal regimes to manage common property resources. Third, when groups increased in size, gradual organizational changes took place: large groups split into independent subgroups or structured interactions into multiple layers while maintaining a single formal organization. Fourth, resource heterogeneity seemed to have had no significant impact on various institutional characteristics. Fifth, social heterogeneity showed statistically significant impacts, especially on institutional complexity, consensus, and the relative importance of governance rules versus resource management rules. Overall, the empirical evidence from this research supports the “threshold hypothesis.” These findings shed light on the rationale of institutional change in common property regimes, and clarify the mechanisms of collective action in traditional societies. Further research may generalize these conclusions to other domains of collective action and to present-day applications.

Helper response to experimentally manipulated predation risk in the cooperatively breeding cichlid Neolamprologus pulcher

Background We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: ‘pay-to-stay’ PS, ‘risk avoidance’ RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy. Methodology/Principal Findings Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, ‘punishment’ by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS). Conclusions/Significance We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were inconsistent with RB.

Social skills as predictors of communication, performance and quality of collaboration in project-based learning

The assumption that social skills are necessary ingredients of collaborative learning is well established but rarely empirically tested. In addition, most theories on collaborative learning focus on social skills only at the personal level, while the social skill configurations within a learning group might be of equal importance. Using the integrative framework, this study investigates which social skills at the personal level and at the group level are predictive of task-related e-mail communication, satisfaction with performance and perceived quality of collaboration. Data collection took place in a technology-enhanced long-term project-based learning setting for pre-service teachers. For data collection, two questionnaires were used, one at the beginning and one at the end of the learning cycle which lasted 3 months. During the project phase, the e-mail communication between group members was captured as well. The investigation of 60 project groups (N = 155 for the questionnaires; group size: two or three students) and 33 groups for the e-mail communication (N = 83) revealed that personal social skills played only a minor role compared to group level configurations of social skills in predicting satisfaction with performance, perceived quality of collaboration and communication behaviour. Members from groups that showed a high and/or homogeneous configuration of specific social skills (e.g., cooperation/compromising, leadership) usually were more satisfied and saw their group as more efficient than members from groups with a low and/or heterogeneous configuration of skills.

Antimicrobial drug use and risk factors associated with treatment incidence and mortality in Swiss veal calves reared under improved welfare conditions

Ninety-one Swiss veal farms producing under a label with improved welfare standards were visited between August and December 2014 to investigate risk factors related to antimicrobial drug use and mortality. All herds consisted of own and purchased calves, with a median of 77.4% of purchased calves. The calves' mean age was 29±15days at purchasing and the fattening period lasted at average 120±28 days. The mean carcass weight was 125±12kg. A mean of 58±33 calves were fattened per farm and year, and purchased calves were bought from a mean of 20±17 farms of origin. Antimicrobial drug treatment incidence was calculated with the defined daily dose methodology. The mean treatment incidence (TIADD) was 21±15 daily doses per calf and year. The mean mortality risk was 4.1%, calves died at a mean age of 94±50 days, and the main causes of death were bovine respiratory disease (BRD, 50%) and gastro-intestinal disease (33%). Two multivariable models were constructed, for antimicrobial drug treatment incidence (53 farms) and mortality (91 farms). No quarantine, shared air space for several groups of calves, and no clinical examination upon arrival at the farm were associated with increased antimicrobial treatment incidence. Maximum group size and weight differences >100kg within a group were associated with increased mortality risk, while vaccination and beef breed were associated with decreased mortality risk. The majority of antimicrobial treatments (84.6%) were given as group treatments with oral powder fed through an automatic milk feeding system. Combination products containing chlortetracycline with tylosin and sulfadimidine or with spiramycin were used for 54.9%, and amoxicillin for 43.7% of the oral group treatments. The main indication for individual treatment was BRD (73%). The mean age at the time of treatment was 51 days, corresponding to an estimated weight of 80-100kg. Individual treatments were mainly applied through injections (88.5%), and included administration of fluoroquinolones in 38.3%, penicillines (amoxicillin or benzylpenicillin) in 25.6%, macrolides in 13.1%, tetracyclines in 12.0%, 3th and 4th generation cephalosporines in 4.7%, and florfenicol in 3.9% of the cases. The present study allowed for identifying risk factors for increased antimicrobial drug treatment and mortality. This is an important basis for future studies aiming at reducing treatment incidence and mortality in veal farms. Our results indicate that improvement is needed in the selection of drugs for the treatment of veal calves according to the principles of prudent use of antibiotics.

(Table 1) Species abundance at DSDP Hole 63-467

Neogene palynofloras of southern California have been all too infrequently studied. Previous investigations of Pacific Coast sediments have been largely restricted to Pacific Northwest locales. Some important studies include those by Gray (1964), Wolfe, Hopkins, and Leopold (1966), Wolfe and Leopold (1967), Hopkins (1968), Piel (1969, 1977), Ballog, Sparks, and Waloweek (1972), and Musich (1973). The only published study of southern California materials is that of Heusser (1978) on Holocene sediments of the Santa Barbara basin. Most of these studies are concerned with the microflora from a particular formation; thus they have limited stratigraphic value and in most cases involve nonmarine to marginal marine rocks where no planktonic zonation was available. Musich's (1973) study was the first attempt at tying pollen assemblages to a planktonic zonation over an extended stratigraphic interval (Miocene to Pleistocene).Its location in the southern California Borderland and the sedimentary sections sampled make Leg 63 extremely valuable in deciphering the palynologic history of the Pacific Coast Neogene. Site 467 was chosen for our initial detailed study, because the relatively slow sedimentation rate provides an almost complete Neogene sequence of mainly terrigenous sediments and reliable planktonic age control is available.The goals of this study were to: (1) establish a reference section of Neogene palynomorph assemblages; (2) develop biostratigraphic criteria for use in correlation with other localities; (3) correlate the palynologic assemblages with the planktonic zonations; and (4) study the paleoenvironmental history in the southern California Neogene.