Kent State University

About: Kent State University is a education organization based out in Kent, Ohio, United States. It is known for research contribution in the topics: Liquid crystal & Population. The organization has 10897 authors who have published 24607 publications receiving 720309 citations. The organization is also known as: Kent State & KSU.

The Mutual Exclusivity Bias in Children's Word Learning

Abstract: Nearly every recent account of children's word learning has addressed the claim that children are biased to construct mutually exclusive extensions, that is, that they are disposed to keep the set of referents of one word from overlapping with those of others. Three basic positions have been taken--that children have the bias when they first start to learn words, that they never have it, and that they acquire it during early childhood. A review of diary and test evidence as well as the results of four experiments provide strong support for this last view and indicate that the bias develops in the months following the second birthday but does not gain full strength or become accessible to consciousness until sometime after the third birthday. Several studies also show that, after this point, it can still be counteracted by information in input or by a strong belief that something belongs to the extension of a particular word. The full body of evidence is compatible with the view that mutual exclusivity is the default option in children's and adults' procedures for integrating the extensions of new and old words. We present several arguments for the adaptive value of this kind of bias.

Evolution of Human Walking

Abstract: �ked to choose the most distinc­ tive feature of the human spe­ cies, many people would cite our massive brain. Others might men­ tion our ability to make and use so­ phisticated tools. A third feature also sets us apart: our upright mode of locomotion, which is found only in human beings and our immediate an­ cestors. All other primates are basical­ ly quadrupedal, and with good reason: walking on two limbs instead of four has many drawbacks. It deprives us of speed and agility and all but elim­ inates our capacity to climb trees, which yield many important primate foods, such as fruits and nuts. For most of this century evolution­ ary theorists have held that human ancestors evolved this strange mode of locomotion because it freed their hands to carry the tools their larger brains enabled them to make. Over the past two decades, however, knowledge of the human fossil record has ex­ panded. Neither a unique brain nor stone tools are in evidence among our earliest known ancestors, the austra­ lopithecines of three million years ago and more. Yet these same ancestors do clearly show many of the hallmarks of bipedal walking. How long had human ancestors been walking upright? Was bipedal­ ity fully developed in the hominids of three million years ago, or did they

Refining our Understanding of Traumatic Growth in the Face of Terrorism: Moving from Meaning Cognitions to Doing what is Meaningful

Abstract: Recent studies related to global terrorism have suggested the potential of posttraumatic growth (PTG) following experiences of terror exposure. However, investigations of whether psychological distress is reduced or increased by PTG in other trauma contexts have been inconsistent. Results from our studies conducted in New York following the attacks of 11 September 2001 and in Israel during recent tumultuous periods of violence and terrorism, the Al Aqsa Intifada, have found posttraumatic growth to be related to greater psychological distress, more right-wing political attitudes, and support for retaliatory violence. Only when individuals were deeply involved in translating growth cognitions to growth actions in our research on the forced disengagement of settlers from Gaza did we find positive benefit in posttraumatic growth. Findings are considered within the framework of a new formulation of action-focused growth. De recentes recherches en rapport avec le terrorisme international ont souligne le potentiel du developpement post-traumatique (PTG) decoulant de la confrontation a la terreur. Toutefois, les travaux cherchant a savoir si la detresse psychologique etait attenuee ou accentuee par le PTG dans d’autres contextes traumatiques se sont reveles contradictoires. Nos investigations a New York apres l’attentat du 11 septembre 2001 et en Israel durant des periodes recentes de violence et de terrorisme, la seconde Intifada, ont montre que le developpement post-traumatique etait plutot liea une grande detresse psychologique, a des opinions politiques de droite et a une attente de represailles. On a observe lors du demenagement obligatoire des colons de Gaza que ce n’est que lorsque les individus etaient profondement impliques dans la transformation des cognitions de developpement en actions de developpement que le developpement post-traumatique avait des retombees positives. Ces resultats sont apprehendes dans le cadre d’une nouvelle approche du developpement centre sur l’action.

The Volatility and Price Sensitivities of Managerial Stock Option Portfolios and Corporate Hedging

Abstract: We use estimates of the Black-Scholes sensitivity of managers' stock option portfolios to stock return volatility and the sensitivity of managers' stock and stock option portfolios to stock price to test the relationship between managers' risk preferences and hedging activities. We find that as the sensitivity of managers' stock and stock option portfolios to stock price increases, firms tend to hedge more. However, as the sensitivity of managers' stock option portfolios to stock return volatility increases, firms tend to hedge less. ONE OF THE AGENCY COSTS associated with the corporate form of ownership comes from the risk aversion of the firm's managers. The typical corporate manager has a significant portion of his or her wealth invested in the corporation, both through portfolio holdings and the value of firm-specific human capital. As a result, managers have an incentive to reduce firm risk more than may be desirable from the perspective of an unaffiliated, diversified shareholder. One way to mitigate managerial risk aversion is to provide the manager with contracts that have a payoff structure that is a convex function of the firm's stock price (Smith and Stulz (1985)). Guay (1999) finds that stock options are an important way in which convexity is added to managers' portfolios. However, as recognized by Carpenter (2000) and Lambert, Larcker, and Verrecchia (1991), stock options create two opposing effects on managerial incentives. The first effect is sensitivity to stock return volatility. Due to the convex payoff structure of options, the value of a manager's stock option portfolio increases with the volatility of the firm's stock returns. This sensitivity to stock return volatility should, ceteris paribus, give the manager an incentive to take more risk. The second effect is sensitivity to stock price. This effect comes from the direct link between the payoff of an option and

Fine-particle water and pH in the southeastern United States

Abstract: . Particle water and pH are predicted using meteorological observations (relative humidity (RH), temperature (T)), gas/particle composition, and thermodynamic modeling (ISORROPIA-II). A comprehensive uncertainty analysis is included, and the model is validated. We investigate mass concentrations of particle water and related particle pH for ambient fine-mode aerosols sampled in a relatively remote Alabama forest during the Southern Oxidant and Aerosol Study (SOAS) in summer and at various sites in the southeastern US during different seasons, as part of the Southeastern Center for Air Pollution and Epidemiology (SCAPE) study. Particle water and pH are closely linked; pH is a measure of the particle H+ aqueous concentration and depends on both the presence of ions and amount of particle liquid water. Levels of particle water, in turn, are determined through water uptake by both the ionic species and organic compounds. Thermodynamic calculations based on measured ion concentrations can predict both pH and liquid water but may be biased since contributions of organic species to liquid water are not considered. In this study, contributions of both the inorganic and organic fractions to aerosol liquid water were considered, and predictions were in good agreement with measured liquid water based on differences in ambient and dry light scattering coefficients (prediction vs. measurement: slope = 0.91, intercept = 0.5 μg m−3, R2 = 0.75). ISORROPIA-II predictions were confirmed by good agreement between predicted and measured ammonia concentrations (slope = 1.07, intercept = −0.12 μg m−3, R2 = 0.76). Based on this study, organic species on average contributed 35% to the total water, with a substantially higher contribution (50%) at night. However, not including contributions of organic water had a minor effect on pH (changes pH by 0.15 to 0.23 units), suggesting that predicted pH without consideration of organic water could be sufficient for the purposes of aqueous secondary organic aerosol (SOA) chemistry. The mean pH predicted in the Alabama forest (SOAS) was 0.94 ± 0.59 (median 0.93). pH diurnal trends followed liquid water and were driven mainly by variability in RH; during SOAS nighttime pH was near 1.5, while daytime pH was near 0.5. pH ranged from 0.5 to 2 in summer and 1 to 3 in the winter at other sites. The systematically low pH levels in the southeast may have important ramifications, such as significantly influencing acid-catalyzed reactions, gas–aerosol partitioning, and mobilization of redox metals and minerals. Particle ion balances or molar ratios, often used to infer pH, do not consider the dissociation state of individual ions or particle liquid water levels and do not correlate with particle pH.