The maximum efficiency of nano heat engines depends on more than temperature

Sadi Carnot's theorem regarding the maximum efficiency of heat engines is considered to be of fundamental importance in thermodynamics. This theorem famously states that the maximum efficiency depends only on the temperature of the heat baths used by the engine, but not on the specific structure of baths. Here, we show that when the heat baths are finite in size, and when the engine operates in the quantum nanoregime, a revision to this statement is required. We show that one may still achieve the Carnot efficiency, when certain conditions on the bath structure are satisfied; however if that is not the case, then the maximum achievable efficiency can reduce to a value which is strictly less than Carnot. We derive the maximum efficiency for the case when one of the baths is composed of qubits. Furthermore, we show that the maximum efficiency is determined by either the standard second law of thermodynamics, analogously to the macroscopic case, or by the non increase of the max relative entropy, which is a quantity previously associated with the single shot regime in many quantum protocols. This relative entropic quantity emerges as a consequence of additional constraints, called generalized free energies, that govern thermodynamical transitions in the nanoregime. Our findings imply that in order to maximize efficiency, further considerations in choosing bath Hamiltonians should be made, when explicitly constructing quantum heat engines in the future. This understanding of thermodynamics has implications for nanoscale engineering aiming to construct small thermal machines.Comment: Main text 14 pages. Appendix 60 pages. Accepted in Journal Quantu

SYRINGE AND NEEDLE EXCHANGE PROGRAMS: A VALUABLE HARM REDUCTION TECHNIQUE IN THE BATTLE AGAINST INJECTION DRUG USE

In the last two decades there has been a growing interest surrounding the topic of clean needle exchange programs, the effects they have on injection drug users, their effectiveness in the prevention and spreading of HIV, AIDS and other blood borne pathogens, the cost surrounding the operation of NEPs and SEPs, and their beneficialness on society as a whole. The objective of this research paper is to examine all the aforementioned facets as well as other benefits that stem from NEPs and SEPs. Since injection drug use is driving HIV epidemics in many countries and accounts for almost a third of new infections outside of sub-Saharan Africa, it seems this knowledge is imperative

Gaze on belonging : investigating rural preservice teachers' experiences at a flagship university

This qualitative study examined rural undergraduate students' process of developing a sense of belonging in a teacher preparation program at a large Midwestern public university. Eleven undergraduates, each having completed at least one semester of study on campus, participated in the study. Perspectives of college belonging were explored by gathering data from both rural students (8) and urban students (3). Multiple data sources included student interviews, online public documents, and NCES data of participants' high schools. Three waves of data collection were utilized: a digital story submission and two semi-structured interviews conducted via video conferencing. Constant comparison analysis (Corbin & Straus, 2015) of the participant's experiences within the campus system and at home resulted in the emergence of five dimensions of belongingness development: stressors associated with rurality, reconceptualizing community by integrating goals, considering contributions to campus through reflection on their sense of purpose, finding fit to get comfortable on campus, and dynamic relationships that stimulate development. Interpretation of the findings indicated the importance of recognizing rural community values and supporting new relationship development for rural preservice teachers. Based on these findings, this study suggests adding the dimension of reconceptualizing community goals to college student success models, especially for those students who are cultural minorities and considered on the fringes of campus culture

Work and reversibility in quantum thermodynamics

It is a central question in quantum thermodynamics to determine how irreversible is a process that transforms an initial state $\rho$ to a final state $\sigma$, and whether such irreversibility can be thought of as a useful resource. For example, we might ask how much work can be obtained by thermalizing $\rho$ to a thermal state $\sigma$ at temperature $T$ of an ambient heat bath. Here, we show that, for different sets of resource-theoretic thermodynamic operations, the amount of entropy produced along a transition is characterized by how reversible the process is. More specifically, this entropy production depends on how well we can return the state $\sigma$ to its original form $\rho$ without investing any work. At the same time, the entropy production can be linked to the work that can be extracted along a given transition, and we explore the consequences that this fact has for our results. We also exhibit an explicit reversal operation in terms of the Petz recovery channel coming from quantum information theory. Our result establishes a quantitative link between the reversibility of thermodynamical processes and the corresponding work gain.Comment: 14 page

Influence of physician, patient, and health care system characteristics on the use of outpatient mastectomy‏

BACKGROUND: Breast cancer is the 2nd leading cause of cancer deaths among women in the United States. Breast cancer surgeries can be performed on either an inpatient or ambulatory basis. This systematic review of literature on outpatient mastectomy examines what is known about the factors that influence the use of this procedure, existing public policies, and strategies to promote the appropriate use of outpatient mastectomy. METHODS: Factors associated with the utilization of outpatient mastectomy were categorized and discussed under the following headings: ‘‘patient level,’’ ‘‘physician level,’’ and ‘‘system level.’’ RESULTS: Potential contributing factors to the use of outpatient mastectomy at the patient level were race, educational level, comorbid conditions, cancer stage, and health insurance. Contributing factors at the provider level were demographics, surgeon specialty, and whether physician is an American or international graduate. The associated factors at the system level were state policy and legislation and hospital characteristics. CONCLUSIONS: The evidence in the research literature suggests that the use of outpatient mastectomy is a function of interactions between patient and physician characteristics, managed care influences, and the state policies and law

A Comparison of Empathy in Sophomore and Senior Baccalaureate Nursing Students

Empathy is a cognitive process rather than an emotional and is often learned through life. Hildegard Peplau’s theory of interpersonal relations explains the importance of the nurse having a shared experience with the patient. Empathy is a crucial skill for nursing students to develop because it is shown that nurses showing empathy is directly related to improved patient satisfaction. Empathy levels tend to decrease as students progress throughout nursing school. The purpose of this study is to examine the empathy levels in sophomore baccalaureate nursing students compared to senior baccalaureate nursing students. Using a descriptive comparison design and a cross-sectional survey will allow adequate representation for data collection

Spatial and temporal colonization dynamics of segmented filamentous bacteria is influenced by gender, age and experimental infection with Helicobacter hepaticus in Swiss Webster mice

In this study, we examined colonization dynamics of segmented filamentous bacteria (SFB) in intestine of Swiss Webster (SW) mice infected with Helicobacter hepaticus (Hh). At 8 weeks post-inoculation with Hh (WPI), cecal and colonic SFB levels in the control males were significantly lower compared to those at 16 WPI. Hh infection in both genders did not alter SFB levels in the jejunum and ileum, but increased SFB levels in the cecum and colon of males compared to the controls (P < 0.05) at 8 WPI. At 16 WPI, the Hh-infected females contained lower levels of SFB in the jejunum, cecum and colon compared to the female controls. Irrespective of gender, aging and Hh infection, the Il-17A mRNA levels decreased from the small intestine to the cecum and then to the colon, whereas the Foxp3 mRNA levels were comparable in these intestinal regions. There were significant differences in Il-17A mRNA levels in the ileum (P < 0.05, R2 = 0.31), with females having greater Il-17A mRNA levels than males, and higher SFB colonization levels related to more Il-17A mRNA. These results indicate that aging and gender play an important role in colonization dynamics of intestinal SFB and ileal SFB-associated Th17 response.United States. National Institutes of Health (P30-ES002109)United States. National Institutes of Health (R01OD11141)United States. National Institutes of Health (R01-CA067529

Improving Pharmacy Education and Patient Centered Care Through Virtual Reality

This qualitative research explored the impact of immersive virtual reality (VR) experiences on student pharmacist knowledge, attitudes, and anticipated behaviors, when used as a supplement to traditional didactic education. Participants completed one or more simulated VR experiences role-playing a person with Alzheimer\u27s Disease, which included experiencing realistic visual and auditory disturbances, struggling with language comprehension, and displaying symptoms of aphasia. Post experience, students completed several short essay prompts. Overall, the study assessed student\u27s self-perceived empathy and anticipated changes to provision of patient care as a result of this activity. Major categories of themes that emerged included 1.) the dementia experience (communication and isolation, feeling like a burden, scared and helpless, confused, altered perception), 2.) importance of patient centered care (patient centered care, pharmacist perception, importance of caregiver care and inclusion, empathy), and 3.) resultant changes in practice (approach slowly and calmly, regimen simplicity and total medication care, monitor signs and symptoms, trust and rapport).https://dune.une.edu/cecespring2022/1014/thumbnail.jp

The Stress of Public Speaking Increases Cortisol Levels in Undergraduates: Is increased Preparation Really the Best Remedy?

Perceived stress is prevalent among the undergraduate population. When this stress persists, it has the potential to lead to mental health illnesses. Recent research shows 85% of students experience overwhelming anxiety from academic pressures. Physiologically, during stressful events, cortisol levels rise in the body which disrupts homeostasis. The anticipation prior to a class presentation, a form of public speaking, is a common source of perceived stress among undergraduates. The focus of this experiment was to determine if there is a correlation between factors such as increased preparedness, sleep, level of understanding, perceived anxiety and physiological stress parameters. Twenty-eight student volunteers with an impending oral presentation were enrolled from both 100- level and 200-level undergraduate courses. At baseline and on the day of the presentation, salivary cortisol, heart rate, and blood pressure were measured. The participants were also asked to complete the Beck’s Anxiety Inventory (BAI). Compared to baseline, cortisol levels on the day of the presentation were significantly increased in both groups. The change in salivary cortisol levels did not correlate with the number of hours spent preparing, the level of understanding nor hours of sleep the night before the presentation. However, the analyses revealed a trend toward an inverse correlation between the self-reported level of understanding and change in cortisol levels. Essentially, students who felt ambiguous toward their level of understanding of their presentation experienced lower changes in cortisol levels when compared to those students who reported a stronger understanding of the material. This study confirms that undergraduates’ perceived stress in anticipation of public speaking does manifest in significantly elevated cortisol levels. It does not provide a link between increased preparation and reduction of stress parameters. Future studies could focus on alternative methods such as mindfulness and meditation and their efficacy in reducing undergraduate stress associated with public speaking