Publicness of goods and violent conflict : evidence from Colombia

How the degree of publicness of goods affect violent conflict? Based on the theoretical model in Esteban and Ray (2001) we find that the effect of the degree of publicness depends on the group size. When the group is small (large), the degree of publicness increases (decreases) the likelihood of conflict. This opens an empirical question that we tackle using microdata from the Colombian conflict at the municipality level. We use three goods with different publicness degree to identify the sign of the effect of publicness on conflict. These goods are coca crops (private good), road density (public good subject to congestion) and average education quality (a purer public good). After dealing with endogeneity issues using an IV approach, we find that the degree of publicness reduces the likelihood of both paramilitary and guerrilla attacks. Moreover, coca production exacerbates conflict and the provision of both public goods mitigates conflict. These results are robust to size, geographical, and welfare controls. Policies that improve public goods provision will help to fight the onset of conflict.

Rensch's rule in large herbivorous mammals derived from metabolic scaling

Rensch’s rule, which states that the magnitude of sexual size dimorphism tends to increase with increasing body size, has evolved independently in three lineages of large herbivorous mammals: bovids (antelopes), cervids (deer), and macropodids (kangaroos). This pattern can be explained by a model that combines allometry,life-history theory, and energetics. The key features are thatfemale group size increases with increasing body size and that males have evolved under sexual selection to grow large enough to control these groups of females. The model predicts relationships among body size and female group size, male and female age at first breeding,death and growth rates, and energy allocation of males to produce body mass and weapons. Model predictions are well supported by data for these megaherbivores. The model suggests hypotheses for why some other sexually dimorphic taxa, such as primates and pinnipeds(seals and sea lions), do or do not conform to Rensh’s rule.

Social organization of marine Tucuxi dolphins, Sotalia guianensis, in the Cananeia Estuary of southeastern Brazil

Social organization is an important component of the population biology of a species that influences gene flow, the spatial pattern and scale of movements, and the effects of predation or exploitation by humans. An important element of social structure in mammals is group fidelity, which can be quantified through association indices. To describe the social organization of marine tucuxi dolphins (Sotalia guianensis) found in the Cananeia estuary, southeastern Brazil, association indices were applied to photo-identification data to characterize the temporal stability of relationships among members of this population. Eighty-seven days of fieldwork were conducted from May 2000 to July 2003, resulting in direct observations of 374 distinct groups. A total of 138 dolphins were identified on 1-38 distinct field days. Lone dolphins were rarely seen, whereas groups were composed of up to 60 individuals (mean +/- 1 SD = 12.4 +/- 11.4 individuals per group). A total of 29,327 photographs were analyzed, of which 6,312 (21.5%) were considered useful for identifying individuals. Half-weight and simple ratio indices were used to investigate associations among S. guianensis as revealed by the entire data set, data from the core study site, and data from groups composed of <= 10 individuals. Monte Carlo methods indicated that only 3 (9.3%) of 32 association matrices differed significantly from expectations based on random association. Thus, our study suggests that stable associations are not characteristic of S. guianensis in the Cananeia estuary.

Fluctuating abundance of humpback whales (Megaptera novaeangliae) in a calving ground off coastal Brazil

The humpback whale (Megaptera novaeangliae) population that uses Abrolhos Bank, off the east coast of Brazil as a breeding ground is increasing. To describe temporal changes in the relative abundance of humpback whales around Abrolhos, seven years (1998-2004) of whale count data were collected during July through to November. During one-hour-scans, observers determined group size within 9.3 km (5 n.m.) of a land-based observing station. A total Of 930 scans, comprising 7996 sightings of adults and 2044 calves were analysed using generalized linear models that included variables for time of day, day of the season, years and two-way interactions as possible predictors. The pattern observed was the gradual build-up and decline in whale counts within seasons. Patterns and peaks of adult and calf counts varied among years. Although fluctuation was observed, there was generally an increasing trend in adult counts among years. Calf counts increased only in 2004. These fluctuations may have been caused by some environmental conditions in humpback whales` summering grounds and also by changes in spatial-temporal concentrations in Abrolhos Bank. The general pattern observed within the study area mirrored what was observed in the whole Abrolhos Bank. Knowledge of the consistency with which humpback whales use this important nursing area should prove beneficial for designing future monitoring programmes especially related to whale watching activities around Abrolhos Archipelago.

Guides of the Falu Mine : Perceptions of Differences and Similarities onDomestic and International Visitors

Industrial heritage tourism has been in focus for many academic studies and tourism is an alternative developmental tool for mines and contributes to their economic success. This thesis is about the Falu Mine in Dalarna, Sweden, which has World Heritage status since 2001 and is one of the biggest attractions in the region. Its history and cultural importance are reasons for the importance of preserving the heritage. The Falu Mine is under the management of the Great Copper Mountain Trust and one of their ambitions is to ensure the continuous popularity among domestic and international visitors. In order to gain a better understanding of the visitors and to find strategies to improve performance, a visitor survey has been conducted in the summer of 2011. It is the authors believe that the guides of the Falu Mine have the best available insight and that their perceptions help to add to the understanding about the visitors. Therefore, this thesis aims to explore the perceptions of the guides about their visitors, to investigate how the perceptions correspond to the statistical results and to study if there are any differences between domestic and international visitors. The mixed methods approach will increase the depth and accuracy of the results, by linking qualitative with quantitative data. The results show that differences between domestic and international visitors exist, both proven by interviews with the guides and the visitor survey. These differences occur in the factors, such as level of education of the visitors, group size and number of children in the group, knowledge of the visitors prior to and after the visit, sources of information and the fulfillment of the visitor expectations. The perceptions emphasize how these differences impact the guided tours. The guides of the Falu Mine have to be aware of those differences in order to adjust the tour accordingly, as well as the management of the Falu Mine can use this knowledge in order to identify strategies for improving performance.

A blue whale (Balaenoptera musculus) feeding ground in a southern Australian coastal upwelling zone

A localised aggregation of blue whales. which may be pygmy blue whales (B. m. brevicauda), occurs in southern Australian coastal waters (between I39°45'E-143°E) during summer and autumn (December-May), where they feed on coastal krill (Nyctiphanes australis). a species which often forms surface swarms. While the abundance of blue whales using this area is unknown, up to 32 blue whales have been sighted in individual aerial  surveys. Krill appear to aggregate in response to enhanced productivity  resulting from the summer-autumn wind-forced Bonney Coast upwelling along the continental shelf. During the upwelling's quiescent (winter-spring) period. blue whales appear to be absent from the region. Krill surface  swarms have been associated with 48% of 261 blue whale sightings since 1998, with direct evidence of feeding observed in 36% of all sightings. Mean blue whale group size was 1.55 (SD =0.839), with all size classes represented including calves. This seasonally predictable upwelling system is evidently a regular feeding ground for blue whales, and careful  management of human activities is required there.

A decision support tool for resource allocation in batch manufacturing

A decision support tool for production planning is discussed in this paper to perform the job of machine grouping and labour allocation within a machining line. The production plans within the industrial partner have been historically inefficient because the relationship between the cycle times, the machine group size, and the operator's utilisation hasn't been properly understood. Starting with a simulation model, a rule-base has been generated to predict the operator's utilisation for a range of production settings. The resource allocation problem is then solved by breaking the problem into a series of smaller sized tasks. The objective is to minimise the number of operators and the difference between the maximum and minimum cycle times of machines within each group. The results from this decision support tool is presented for the particular case study.

Reliability and validity of the system for observing children's activity and relationships during play (SOCARP)

Background: Children frequently engage in diverse activities that are broadly defined as play, but little research has documented children’s activity levels during play and how they are influenced by social contexts. Assessing potentially modifiable conditions that influence play behavior is needed to design optimal physical activity interventions.

Methods: System for Observing Children’s Activity and Relationships during Play (SOCARP) was developed to simultaneously assess children’s physical activity, social group sizes, activity type, and social behavior during play. One hundred and fourteen children (48 boys, 66 girls; 42% overweight) from 8 elementary schools were observed during recess over 24 days, with 12 days videotaped for reliability purposes. Ninety-nine children wore a uni-axial accelerometer during their observation period.

Results: Estimated energy expenditure rates from SOCARP observations and mean accelerometer counts were significantly correlated (r = .67; P < .01), and interobserver reliabilities (ie, percentage agreement) for activity level (89%), group size (88%), activity type (90%) and interactions (88%) met acceptable criteria. Both physical activity and social interactions were influenced by group size, activity type, and child gender and body weight status.

Conclusions: SOCARP is a valid and reliable observation system for assessing physical activity and play behavior in a recess context.

Passenger walking speed data for Australian domestic airports

The data covers the speed at which passengers walk through Australian domestic airport terminals, based on their group size.

Distance from water, sex and approach direction influence flight distances among habituated black swans

In many animals, response to predators occurs at greater distances the further an individual is from a refuge, but this has rarely been investigated in birds. Here, we test the hypothesis that the further from refuge (i.e. water) a foraging black swan Cygnus atratus is situated, the longer its flight initiation distance (FID) in response to a pedestrian approach on land. As predicted, swans situated farther from water exhibited longer FIDs compared with those closer to the shore. In addition, there was the possibility of an interesting interaction effect (p < 0.061) of sex and direction of approach on FID. Whilst males tended to not alter their response in relation to the angle of approach relative to the water, females tended to respond at longer distances, when approached from the shore than when approached from the land or parallel to the shore. This is one of the first reports of sex differences in FIDs for birds, with sex differences only manifesting themselves under certain approach types. Group size, the order of repeated approaches, and time of day did not influence responses, although starting distance of approach was positively related to FID.

Investigating Facebook groups through a random graph model

Facebook disseminates messages for billions of users everyday. Though there are log files stored on central servers, law enforcement agencies outside of the U.S. cannot easily acquire server log files from Facebook. This work models Facebook user groups by using a random graph model. Our aim is to facilitate detectives quickly estimating the size of a Facebook group with which a suspect is involved. We estimate this group size according to the number of immediate friends and the number of extended friends which are usually accessible by the public. We plot and examine UML diagrams to describe Facebook functions. Our experimental results show that asymmetric Facebook friendship fulfills the assumption of applying random graph models.

At-sea associations in foraging little penguins

Prey distribution, patch size, and the presence of conspecifics are important factors influencing a predator's feeding tactics, including the decision to feed individually or socially. Little is known about group behaviour in seabirds as they spend most of their lives in the marine environment where it is difficult to observe their foraging activities. In this study, we report on at-sea foraging associations of little penguins (Eudyptula minor) during the breeding season. Individuals could be categorised as (1) not associating; (2) associating when departing from and/or returning to the colony; or (3) at sea when travelling, diving or performing synchronised dives. Out of 84 separate foraging tracks, 58 (69.0%) involved associations with conspecifics. Furthermore, in a total of 39 (46.4%), individuals were found to dive during association and in 32 (38.1%), individuals were found to exhibit synchronous diving. These behaviours suggest little penguins forage in groups, could synchronise their underwater movements and potentially cooperate to concentrate their small schooling prey.

What determines habitat quality for a declining woodland bird in a fragmented environment: the grey-crowned babbler pomatostomus temporalis in South-Eastern Australia?

Understanding what constitutes high quality habitat is crucial for the conservation of species, especially those threatened with extinction. Habitat quality frequently is inferred by comparing the attributes of sites where a species is present with those where it is absent. However, species presence may not always indicate high quality habitat. Demographic parameters are likely to provide a more biologically relevant measure of quality, including a species' ability to successfully reproduce. We examined factors believed to influence territory quality for the grey-crowned babbler (Pomatostomus temporalis), a cooperatively breeding woodland bird that has experienced major range contraction and population decline in south-eastern Australia. Across three broad regions, we identified active territories and determined the presence of fledglings and the size of family groups, as surrogates of territory quality. These measures were modelled in relation to habitat attributes within territories, the extent of surrounding wooded vegetation, isolation from neighbouring groups, and the size of the neighbourhood population. Fledgling presence was strongly positively associated with group size, indicating that helpers enhance breeding success. Surprisingly, no other territory or landscape-scale variables predicted territory quality, as inferred from either breeding success or group size. Relationships between group size and environmental variables may be obscured by longer-term dynamics in group size. Variation in biotic interactions, notably competition from the noisy miner (Manorina melanocephala), also may contribute. Conservation actions that enhance the number and size of family groups will contribute towards reversing declines of this species. Despite associated challenges, demographic studies have potential to identify mechanistic processes that underpin population performance; critical knowledge for effective conservation management.

Obtenção de conceitos no indivíduo e no grupo

O objetivo deste trabalho foi comparar o desempenho de indivíduos e grupos e verificar a influência do tamanho do grupo na solução de problemas sobre a obtenção de conceitos conjuntivos, apresentados através do paradigma de recepção. Usou-se como variável independente o tamanho do grupo, com três níveis: grupos de dois, três e quatro elementos. Os principais resultados encontrados foram: 1) Os grupos de três e quatro elementos apresentaram um desempenho (número de problemas resolvidos corretamente) significantemente superior aos individuos. 2) Não se observaram diferenças significativas de desempenho entre os grupos de dois e os indivíduos. 3) Os grupos de três e quatro elementos apresentaram um desempenho significantemente superior aos grupos de dois. 4) Não se observaram diferenças significativas de desempenho entre os grupos de três e quatro elementos. O modelo A de Lorge e Solomon (1955), segundo o qual o desempenho do grupo reflete o desempenho de seu membro mais apto, foi usado para interpretar os resultados obtidos.