148,183 research outputs found
The Social Relationships of Captive African Elephant (Loxodonta africana) Juveniles
In situ female African bush elephants (Loxodonta africana) live in a fission- fusion society comprised of “core groups” in which adult females associate with their dependent offspring (Archie, Moss, & Alberts, 2006). Most of the animals in a core group are related (Archie et al., 2006), but kinship is not the only contributor to elephant sociality.Pre-reproductive females (allomothers) often assist in the care of calves and juveniles (Lee, 1987). The concept of inclusive fitness (Riedman, 1982) is the favored hypothesis for the evolution of allomothering. Zoological settings, with varied social groupings, provide the perfect opportunity to test this hypothesis (Schulte, 2000). During the winter of 2017-2018, four female elephants at the Indianapolis Zoo were grouped together temporarily (one hour per day) and given access to an outside yard. The group included an adolescent (Zahara), her juvenile sister (Nyah), another female juvenile (Kalina) and the (unrelated) dominant elephant at the facility (Sophi). Video recordings of the animals moving freely in the yard were examined to document proximity, changes in proximity, and behavioral observations. Zahara spent more time close to the calves than did Sophi. Zahara and each of the juveniles made and broke contact equally often; however, the juveniles were primarily responsible for maintaining proximity to Sophi. Zahara, surprisingly, associated more with Kalina than with Nyah. Finally, Zahara displayed far more agonistic behaviors towards Kalina than towards Nyah. These results suggest that Zahara was an allomother to both juveniles, favoring Nyah over Zahara, but also interacted with Kalina as a peer
Productivity Environmental Preference Survey (PEPS) of Undergraduate Nursing Students - A Generational Perspective
A change in the generational demographics of college students is occurring throughout the United States. By 2012, the number of Millennial students, those born from 1982 to 2003, will jump from 44 percent to 75 percent of the total college enrollment. It has been suggested that their methods of learning are different from those of previous generations. The purpose of this study was to identify and compare individual productivity and learning style preferences of undergraduate nursing students that fall into the Generation X and Millennial age cohort. Using the Dunn & Dunn Learning Style Model and the Productivity Environmental Preferences Survey(PEPS), the study examined the conditions under which an adult learner is most likely to achieve the highest level of productivity and learning. Seventy-three undergraduate nursing students in their junior year of college were surveyed on twenty different stimuli subscales. Overall results did not demonstrate strong learning style preferences in either group and demonstrated more similarities than differences. Four areas of slightly stronger preferences were noted: Generation X preference for learning from authority figures verses peer learning and the need for frequent snacking for increased productivity and learning. Millennia} students demonstrated a greater preference for wanting a more structured learning environment and having afternoon and evenings as the time of their highest level of energy for learning more difficult content. Using at-test and 2-tailed significance analysis showed a statistical significant difference between the generational cohorts in the subscales referring to Authority oriented learner , Time of day and Afternoon . Understanding the academic productivity and preferred learning style preferences of these two groups is important for both curriculum planning and policies to help increase student retention
The molecular genetics and cellular mechanisms underlying pulmonary arterial hypertension
Pulmonary arterial hypertension (PAH) is an incurable disorder clinically characterised by a sustained elevation of mean arterial pressure in the absence of systemic involvement. As the adult circulation is a low pressure, low resistance system, PAH represents a reversal to a foetal state. The small pulmonary arteries of patients exhibit luminal occlusion resultant from the uncontrolled growth of endothelial and smooth muscle cells. This vascular remodelling is comprised of hallmark defects, most notably the plexiform lesion. PAH may be familial in nature but the majority of patients present with spontaneous disease or PAH associated with other complications. In this paper, the molecular genetic basis of the disorder is discussed in detail ranging from the original identification of the major genetic contributant to PAH and moving on to current next-generation technologies that have led to the rapid identification of additional genetic risk factors. The impact of identified mutations on the cell is examined, particularly, the determination of pathways disrupted in disease and critical to pulmonary vascular maintenance. Finally, the application of research in this area to the design and development of novel treatment options for patients is addressed along with the future directions PAH research is progressing towards
Substance abuse treatment: what do we know? an economist's perspective
The substance abuse treatment literature has basically dealt with four important questions: 1) Is treatment effective? 2) Are all programs equally effective? 3) why do programs differ in their effectiveness? and 4) which treatments are most cost-effective?. This paper reviews the substance abuse literature around these four questions
A consistent estimator for the binomial distribution in the presence of "incidental parameters": an application to patent data
In this paper a consistent estimator for the Binomial distribution in the presence of incidental parameters, or fixed effects, when the underlying probability is a logistic function is derived. The consistent estimator is obtained from the maximization of a conditional likelihood function in light of Andersen's work. Monte Carlo simulations show its superiority relative to the traditional maximum likelihood estimator with fixed effects also in small samples, particularly when the number of observations in each cross-section, T, is small. Finally, this new estimator is applied to an original dataset that allows the estimation of the probability of obtaining a patent
Dollars and Performance: Treating Alcohol Misuse in Maine
If public funds are allocated efficiently, then an increase in funding should improve the performance of substance abuse treatment programs. In the data used in this paper, performance (measured as abstinence rates) and expenditures per patient are not positively correlated. One explanation is
that funding is endogeneous, i.e. programs treating more difficult patients receive more funding. The data comes from all Maine´s outp/atient drug-free programs that received public funding between 1991 and 1994. After controlling for endogeneity, this paper concludes that the marginal impact of expenditures per patient on abstinence rates is small and statistically insignificantly different from
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