Chemical Bonding in the C2_2 Molecule

Bonding in the C$_2$ molecule is investigated with CAS(8,8) wave functions using canonical MOs. In a subsequent step, orthogonal atomic orbitals are constructed by localizing the CASSCF MOs on the two carbon atoms with an orthogonal transformation. This orbital transformation causes an orthogonal transformation of the configuration state functions (CSF) spanning the function space of the singlet ground state of C$_2$. Instead of CSFs built from canonical MOs one gets CSFs of orthogonal deformed atomic orbitals (AO). This approach resembles the orthogonal valence bond methods (OVB) CSFs which are very different from conventional VB, based on non-orthogonal AOs. To get used to the different argumentation, the bonding situation in ethane (single bond), ethene (double bond), and the nitrogen molecule (triple bond) are also studied. The complex bonding situation in C$_2$ is caused by the possibility to excite an electron with spin flip from the doubly occupied 2s AO into the 2p subshell, the resulting high-spin $^5S_u$ state of the carbon atom allows for a better reduction of the Pauli repulsion. But the electron structure around the equilibrium distance does not allow to say that C$_2$ in its ground state has a double, or triple, or even a quadruple bond

How Undergraduates Are Affected by Service Participation

Based on entering freshman and follow-up data collected from 3,450 students (2,287 women and 1,163 men) attending 42 institutions with federally funded community service programs, the impact of community service participation on undergraduate student development was examined. Even after regression analyses controlled for individual student characteristics at the time of college entry, including the propensity to engage in service, results indicate that participating in service during the undergraduate years substantially enhances the student\u27s academic development, life skill development, and sense of civic responsibility

Long-Term Effects of Volunteerism During the Undergraduate Years

A growing number of colleges and universities in the United States have become actively engaged in encouraging their undergraduate students to participate in some form of volunteer service (Cohen & Kinsey, 1994; Levine, 1994; Markus, Howard, & King, 1993; O\u27Brien, 1993). Further, service is increasingly being incorporated into the curriculums of major and general education courses (Cohen & Kinsey, 1994; Levine, 1994). While relatively few colleges include service learning or volunteer service as a curricular requirement, the number is growing and such a requirement has become an increasingly frequent topic of debate (Markus, Howard, & King, 1993). That the top leadership in higher education has become increasingly supportive of service as part of the [End Page 187] undergraduate experience is reflected in the phenomenal growth of the Campus Compact, a consortium of colleges and universities dedicated to promoting service among students and faculty. The Campus Compact now numbers well over 500 institutions

Implementation of a surgical unit-based safety programme in African hospitals: a multicentre qualitative study.

Background: A Surgical Unit-based Safety Programme (SUSP) has been shown to improve perioperative prevention practices and to reduce surgical site infections (SSI). It is critical to understand the factors influencing the successful implementation of the SUSP approach in low- and middle-income settings. We undertook a qualitative study to assess viability, and understand facilitators and barriers to implementing the SUSP approach in 5 African hospitals. Methods: Qualitative study based on interviews with individuals from all hospitals participating in a WHO-coordinated before-after SUSP study. The SUSP intervention consisted of a multimodal strategy including multiple SSI prevention measures combined with an adaptive approach aimed at improving teamwork and safety culture. Results: Thirteen interviews (5 head surgeons, 3 surgeons, 5 nurses) were conducted with staff from five hospital sites. Identified facilitators included influential individuals (intrinsic motivation of local SUSP teams, boundary spanners, multidisciplinary engagement, active leadership support), peer-to-peer learning (hospital networking and positive deviance, benchmarking), implementation fitness (enabling infrastructures, momentum from previous projects), and timely feedback of infection rates and process indicators. Barriers (organisational 'constipators', workload, mistrust, turnover) and local solutions to these were also identified. Conclusions: Participating hospitals benefitted from the SUSP programme structures (e.g. surveillance, hospital networks, formation of multidisciplinary teams) and adaptive tools (e.g. learning from defects, executive rounds guide) to change perceptions around patient safety and improve behaviours to prevent SSI. The combination of technical and adaptive elements represents a promising approach to facilitate the introduction of evidence-based best practices and to improve safety culture through local team engagement in resource-limited settings

Improving ICD-based semantic similarity by accounting for varying degrees of comorbidity

Finding similar patients is a common objective in precision medicine, facilitating treatment outcome assessment and clinical decision support. Choosing widely-available patient features and appropriate mathematical methods for similarity calculations is crucial. International Statistical Classification of Diseases and Related Health Problems (ICD) codes are used worldwide to encode diseases and are available for nearly all patients. Aggregated as sets consisting of primary and secondary diagnoses they can display a degree of comorbidity and reveal comorbidity patterns. It is possible to compute the similarity of patients based on their ICD codes by using semantic similarity algorithms. These algorithms have been traditionally evaluated using a single-term expert rated data set. However, real-word patient data often display varying degrees of documented comorbidities that might impair algorithm performance. To account for this, we present a scale term that considers documented comorbidity-variance. In this work, we compared the performance of 80 combinations of established algorithms in terms of semantic similarity based on ICD-code sets. The sets have been extracted from patients with a C25.X (pancreatic cancer) primary diagnosis and provide a variety of different combinations of ICD-codes. Using our scale term we yielded the best results with a combination of level-based information content, Leacock & Chodorow concept similarity and bipartite graph matching for the set similarities reaching a correlation of 0.75 with our expert's ground truth. Our results highlight the importance of accounting for comorbidity variance while demonstrating how well current semantic similarity algorithms perform.Comment: 11 pages, 6 figures, 1 tabl

Evaluation of Learn and Serve America, Higher Education: First Year Report, Volume I

This report presents evaluation results for the first year of the Learn and Serve America, Higher Education (LSAHE) initiative, sponsored by the Corporation for National and Community Service (CNS). It addresses impacts of LSAHE on communities, higher education institutions, and service providers