Viewpoint Discovery and Understanding in Social Networks

The Web has evolved to a dominant platform where everyone has the opportunity to express their opinions, to interact with other users, and to debate on emerging events happening around the world. On the one hand, this has enabled the presence of different viewpoints and opinions about a - usually controversial - topic (like Brexit), but at the same time, it has led to phenomena like media bias, echo chambers and filter bubbles, where users are exposed to only one point of view on the same topic. Therefore, there is the need for methods that are able to detect and explain the different viewpoints. In this paper, we propose a graph partitioning method that exploits social interactions to enable the discovery of different communities (representing different viewpoints) discussing about a controversial topic in a social network like Twitter. To explain the discovered viewpoints, we describe a method, called Iterative Rank Difference (IRD), which allows detecting descriptive terms that characterize the different viewpoints as well as understanding how a specific term is related to a viewpoint (by detecting other related descriptive terms). The results of an experimental evaluation showed that our approach outperforms state-of-the-art methods on viewpoint discovery, while a qualitative analysis of the proposed IRD method on three different controversial topics showed that IRD provides comprehensive and deep representations of the different viewpoints

Gang Brooding in Canada Geese: Role of Parental Condition and Experience

Some Canada Geese (Branta canadensis) raise their broods by themselves (two-parent families), while others raise them in gang broods, defined as two or more broods amalgamated into a single cohesive unit and shepherded by four or more parents. From 1984 to 2005, I individually marked Canada Geese in New Haven County, Connecticut, so that I could compare the characteristics of adults that raise their goslings in gang broods to those of adults that raised their goslings in two-parent families. I wanted to determine if a parent\u27s decision to form a gang brood was influenced by its age or body mass, its own parents (indicating either that the behavior has a genetic component or that the behavior is learned while a gosling), its prior experiences raising broods, or the loss of its mate. Parents tended to use the same brood-rearing approach from one year to the next: 61% of parents of gang broods (i.e., gang-brooders) during one year also were gang-brooders the next year they had goslings; likewise, 65% of parents in two-parent families during one year raised their next brood in a two-parent family. Geese that changed mates from the previous year were more likely to switch brood-rearing approaches than those that stayed with the same mate. As geese gained more years of experience raising goslings, their propensity to form a gang brood increased; only 29% of geese raising broods for the first time formed a gang brood versus 80% for geese with 5 or more years of experience. Geese raised in gang broods themselves were no more likely than geese raised in two-parent families to form gang broods once they became adults and had their own broods. These results indicate that gang brooding is a behavior learned as an adult. I tested the hypothesis that adult geese attending the same gang brood are members of the same extended family but found that geese were as likely to form a gang brood with unrelated individuals as with siblings or parents

Delayed Nesting by Female Canada Geese (Branta Canadensis): Benefits and Costs

In many avian species, females do not nest the first year they attain sexual maturity. I examined the benefits and costs of delayed nesting in a nonmigratory population of Canada Geese (Branta canadensis) in New Haven County, Connecticut, from 1984 through 2008. I individually marked 381 female goslings and monitored them throughout their lives. Eighty-seven females were recruited into the local breeding population; 16 of these started nesting when 1 or 2 years old (young nesters), and 71 started nesting when 3 to 9 years old (delayed nesters). During their first reproductive effort, young nesters and delayed nesters produced similar-sized clutches but young nesters produced fewer hatchlings or fledglings. Young nesters died sooner than delayed nesters, but the two groups were similar in number of years of life following first nesting effort, number of nesting years during life span, and total lifetime production of eggs, hatchlings, and fledglings. Both young nesters and delayed nesters had similar values of λ(m), which is an integrated measure of an individual\u27s propensity fitness. Young nesters weighed more at fledging than delayed nesters, which suggests that larger and healthier females were more likely to become young nesters. Competition among Canada Geese for safe nesting sites on islands was keen in the study area. This may have contributed to the prevalence of delayed nesting because geese that were unable to secure a safe nesting site may have delayed nesting until the following year

Numbers of Human Fatalities, Injuries, and Illnesses in the United States Due to Wildlife

I reviewed published and unpublished papers, government reports, and websites to estimate how many people are injured or killed each year by wildlife or stricken by a zoonotic disease. Over 47,000 people annually in the United States sought medical attention after being attacked or bitten by wildlife, and approximately 8 people died annually. Most bites were by snakes, birds, rodents, and raccoons (Procyon lotor). Each year, wildlife–vehicle collisions resulted in \u3e59,000 human injuries and \u3e440 human fatalities, while wildlife–aircraft collisions added 16 more injuries and 10 fatalities. I also found that \u3e68,000 people each year sought medical assistance for a zoonotic disease, and 243 of these cases were fatal. When wildlife-related casualties and fatalities are summed, \u3e174,000 people were injured or sickened and \u3e700 were killed by wildlife annually. These figures do not mean that wildlife populations should be reduced; they do indicate, however, that wildlife biologists have an opportunity to serve society by preventing human injuries, morbidities, and fatalities resulting from wildlife. In doing so, wildlife biologists will also be protecting the future of wildlife

HOW BIRDS INTERPRET DISTRESS CALLS: IMPLICATIONS FOR APPLIED USES OF DISTRESS CALL PLAYBACKS

Distress call playbacks are used as deterrents to keep birds out of areas where they are causing problems. However, the calls often are ineffective, owing to birds\u27 rapid habitation to them. Recent studies on the functional significance of distress calls indicate that adult passerines only distress call when physically constrained and that the calls are designed to startle the predator holding the caller into releasing it. Further, distress calls attract other birds, which approach the caller to acquire information about the predator. These findings suggest that distress calls would be more effective if their broadcast is paired with a predator model that appears to be grasping the caller. Such a pairing should reinforce a bird\u27s fear of the predator model and delay its habituation to the distress call

Emerging Challenges in Wildlife Management

Several challenges confronting wildlife agencies today will become even more important in the future. These challenges include: reducing threats to human safety, preventing the spread of zoonotic diseases, increasing wildlife populations in suboptimal habitats, managing problems caused by overabundant native species and exotic species, and helping to sustain human food supplies by alleviating wildlife damage to agricultural production. Challenges such as these provide an opportunity for wildlife management to increase its importance in the future, especially for biologists and scientists within the field of wildlife damage management. We have the opportunity to enhance the value of the wildlife resource for society while, at the same time, preserving it for future generations