Saddles in the energy landscape: extensivity and thermodynamic formalism

We formally extend the energy landscape approach for the thermodynamics of liquids to account for saddle points. By considering the extensive nature of macroscopic potential energies, we derive the scaling behavior of saddles with system size, as well as several approximations for the properties of low-order saddles (i.e., those with only a few unstable directions). We then cast the canonical partition function in a saddle-explicit form and develop, for the first time, a rigorous energy landscape approach capable of reproducing trends observed in simulations, in particular the temperature dependence of the energy and fractional order of sampled saddles.Comment: 4 pages, 1 figur

A test of non-equilibrium thermodynamics in glassy systems: the soft-sphere case

The scaling properties of the soft-sphere potential allow the derivation of an exact expression for the pressure of a frozen liquid, i.e., the pressure corresponding to configurations which are local minima in its multidimensional potential energy landscape. The existence of such a relation offers the unique possibility for testing the recently proposed extension of the liquid free energy to glassy out-of-equilibrium conditions and the associated expression for the temperature of the configurational degrees of freedom. We demonstrate that the non-equilibrium free energy provides an exact description of the soft-sphere pressure in glass states

Principals as Human Capital Managers: A Literature Review

This review focuses on the school system's evolution and the principal's role as an administrator. Principalship refers to the professional standards to which a school's leadership aims to meet the needs of staff, students, and parents. The roles include student management, enforcing curriculum, assisting teachers, and allocating material and financial resources to ensure high academic performance. The review identifies that most principals fulfill a minimum requirement of undergraduate and postgraduate education with vast experience as regular teachers, school counselors, or educational professionals.The review identifies several academic preparation programs for state credentialing to become a school administrator. The study reveals that applicants for school leadership roles achieve higher learning goals such as master's or doctoral in education, psychology, and business administration. Most states require a minimum of three years of field experience with diverse communities. Scholars emphasize the need for continued learning programs for effective principalship and managing diverse school communities. Furthermore, each state has a local credentialing agency open to various professionals, thus creating varied leadership experiences for different schools.The review seeks to establish the functions of a principal as a human capital manager. Scholars differentiate human resource management and human capital management by emphasizing the role of principals as business managers whose goal is to steer a school toward the best student, staff, and institutional output. The study uses human capital theory to maximize staff potential and achieve better institutional results. Therefore, the roles of a principal as a human capital manager include recruitment of qualified personnel, provision of professional growth opportunities for various staff, capacity building, and retention of qualified staff

Depressive Symptoms and Eating Behaviors: Do Atypical Symptoms Drive Associations with Food Attentional Bias, Emotional Eating, and External Eating?

Indiana University-Purdue University Indianapolis (IUPUI)Depression is an emerging risk factor for obesity; however, it is unclear whether certain depressive symptoms drive this relationship. Recent evidence suggests that atypical major depressive disorder (MDD) – whose key features include the reversed somatic-vegetative symptoms of hyperphagia (increased appetite) and hypersomnia (increased sleep) – is a stronger predictor of future obesity than other MDD subtypes. The present study sought to examine food attentional bias (increased attention to food cues), emotional eating (eating in response to negative emotions), and external eating (eating in response to external food cues) as candidate mechanisms of the depression-to-obesity relationship. This cross-sectional laboratory study hypothesized that total depressive symptom severity, hyperphagia severity, and hypersomnia severity would all be positively associated with measures of food attentional bias, emotional eating, and external eating. Data were collected from a sample of 95 undergraduate students. Depressive symptom severity was measured using the Hopkins Symptom Checklist (SCL-20); two measures of food attentional bias were obtained from eye tracking with high calorie food images: direction bias and duration bias; and emotional eating and external eating were assessed using the Dutch Eating Behavior Questionnaire. Simultaneous regression models (adjusted for age, sex, race/ethnicity, body mass index, and subjective hunger) revealed total depressive symptom severity and hypersomnia severity were not associated with measures of food attentional bias, while hyperphagia severity was negatively associated with direction bias but not associated with duration bias for high and low calorie food images. Findings related to emotional and external eating are consistent with previous literature: total depressive symptom severity and hyperphagia severity were positively associated with both emotional eating and external eating, and the pattern of results suggests that hyperphagia may be driving relationships between depressive symptoms and these eating behaviors. Hypersomnia severity was not associated with emotional eating and external eating, suggesting this symptom does not play an important role in the relationships between depressive symptoms and these eating behaviors. Future studies should examine prospective associations of hyperphagia severity with food attentional bias, emotional eating, and external eating in larger, more representative samples

Making Sense of Vietnam and Telling the Real Story: Military Women in The Combat Zone

An analysis of Kathryn Marshall\u27s 1987 book, In the Combat Zone: An Oral History of American Women in Vietnam, 1966-1975

Implementing a standardized pediatric bone marrow transplant orientation.

Nurse orientation programs focus on establishing a nurse’s ability to perform skills necessary in the organization’s setting. The purpose of this project was to develop a unit-specific orientation program for the experienced registered nurse transitioning into providing care for pediatric bone marrow transplant (BMT) patients at a local children’s hospital to enhance nurse knowledge and satisfaction. Melnyk and Fineout-Overholt’s rating system for the hierarchy of evidence was used in the selection of articles with high levels of evidence for the critical appraisal of the supporting literature for the program development. The best practices for orientation content provide constructive effects on nursing knowledge, satisfaction, and serve as evidence for the content. Bandura’s Social Cognitive Theory, specifically self-efficacy, was the contributing theoretical framework for advancing the knowledge of pediatric oncology nurses who participate in the orientation program. Orientation materials were obtained and adapted as the main components for a positive orientation at the hospital. A unit-specific orientation based on evidence will provide an operational process for the experienced nurse transitioning to a specialized unit. The results of this project aided in the transition of nurses into the new environment and expected role. After implementation, this project was aimed to increase nurse knowledge and self-efficacy

Streaming Down the Stern-Brocot Tree: Finding and Expressing Solutions to Pell\u27s Equation in SL(2,Z)

This paper explores and elaborates on a method of solving Pell’s equation as introduced by Norman Wildberger. In the first chapters of the paper, foundational topics are introduced in expository style including an explanation of Pell’s equation. An explanation of continued fractions and their ability to express quadratic irrationals is provided as well as a connection to the Stern-Brocot tree and a convenient means of representation for each in terms of 2×2 matrices with integer elements. This representation will provide a useful way of navigating the Stern-Brocot tree computationally and permit us a means of computing continued fractions without the tedium of unraveling nested denominators. The paper also introduces simple unary operations for describing select permutations on continued fractions and, more importantly, their matrix-product counterparts. In the latter chapters of the paper, interesting symmetries appear as a result of using the Wildberger Algorithm. Quadratic forms and the subset of balanced quadratic forms will be shown to act as SL2(Z)-sets. Using this language we explore solutions to the generalized Pell equation and demonstrate a generalization for Norman Wildberger’s algorithm

Using airborne LiDAR Survey to explore historic-era archaeological landscapes of Montserrat in the eastern Caribbean

This article describes what appears to be the first archaeological application of airborne LiDAR survey to historic-era landscapes in the Caribbean archipelago, on the island of Montserrat. LiDAR is proving invaluable in extending the reach of traditional pedestrian survey into less favorable areas, such as those covered by dense neotropical forest and by ashfall from the past two decades of active eruptions by the Soufrière Hills volcano, and to sites in localities that are inaccessible on account of volcanic dangers. Emphasis is placed on two aspects of the research: first, the importance of ongoing, real-time interaction between the LiDAR analyst and the archaeological team in the field; and second, the advantages of exploiting the full potential of the three-dimensional LiDAR point cloud data for purposes of the visualization of archaeological sites and features

Molecular structural order and anomalies in liquid silica

The present investigation examines the relationship between structural order, diffusivity anomalies, and density anomalies in liquid silica by means of molecular dynamics simulations. We use previously defined orientational and translational order parameters to quantify local structural order in atomic configurations. Extensive simulations are performed at different state points to measure structural order, diffusivity, and thermodynamic properties. It is found that silica shares many trends recently reported for water [J. R. Errington and P. G. Debenedetti, Nature 409, 318 (2001)]. At intermediate densities, the distribution of local orientational order is bimodal. At fixed temperature, order parameter extrema occur upon compression: a maximum in orientational order followed by a minimum in translational order. Unlike water, however, silica's translational order parameter minimum is broad, and there is no range of thermodynamic conditions where both parameters are strictly coupled. Furthermore, the temperature-density regime where both structural order parameters decrease upon isothermal compression (the structurally anomalous regime) does not encompass the region of diffusivity anomalies, as was the case for water.Comment: 30 pages, 8 figure

Relationship between Structure, Entropy and Diffusivity in Water and Water-like Liquids

Anomalous behaviour of the excess entropy ($S_e$) and the associated scaling relationship with diffusivity are compared in liquids with very different underlying interactions but similar water-like anomalies: water (SPC/E and TIP3P models), tetrahedral ionic melts (SiO$_2$ and BeF$_2$) and a fluid with core-softened, two-scale ramp (2SRP) interactions. We demonstrate the presence of an excess entropy anomaly in the two water models. Using length and energy scales appropriate for onset of anomalous behaviour, the density range of the excess entropy anomaly is shown to be much narrower in water than in ionic melts or the 2SRP fluid. While the reduced diffusivities ($D^*$) conform to the excess entropy scaling relation, $D^* =A\exp (\alpha S_e)$ for all the systems (Y. Rosenfeld, Phys. Rev. A {\bf 1977}, {\it 15}, 2545), the exponential scaling parameter, $\alpha$, shows a small isochore-dependence in the case of water. Replacing $S_e$ by pair correlation-based approximants accentuates the isochore-dependence of the diffusivity scaling. Isochores with similar diffusivity scaling parameters are shown to have the temperature dependence of the corresponding entropic contribution. The relationship between diffusivity, excess entropy and pair correlation approximants to the excess entropy are very similar in all the tetrahedral liquids.Comment: 24 pages, 4 figures, to be published in Journal of Physical Chemistry