Mapping scientists' career trajectories in the survey of doctorate recipients using three statistical methods.

This paper investigates to what extent there is a 'traditional' career among individuals with a Ph.D. in a science, technology, engineering, or math (STEM) discipline. We use longitudinal data that follows the first 7-9 years of post-conferral employment among scientists who attained their degree in the U.S. between 2000 and 2008. We use three methods to identify a traditional career. The first two emphasize those most commonly observed, with two notions of commonality; the third compares the observed careers with archetypes defined by the academic pipeline. Our analysis includes the use of machine-learning methods to find patterns in careers; this paper is the first to use such methods in this setting. We find that if there is a modal, or traditional, science career, it is in non-academic employment. However, given the diversity of pathways observed, we offer the observation that traditional is a poor descriptor of science careers.

Leak or link? the overrepresentation of women in non-tenure-track academic positions in STEM.

This paper examines gender variation in departures from the tenure-track science, technology, engineering, and math (STEM) academic career pathway to non-tenure-track academic careers. We integrate multiple data sources including the Survey of Earned Doctorates and the Survey of Doctorate Recipients to examine longitudinal career outcomes of STEM doctorate women. We consider three types of careers after receipt of a PhD: academic, academic non-tenure-track, and non-academic positions. We find that STEM women are more likely to hold academic non-tenure-track positions, which are associated with lower job satisfaction and lower salaries among men and women. Explanations including differences in field of study, preparation in graduate school, and family structure only explain 35 percent of the gender gap in non-tenure-track academic positions.

Secondary care usage and characteristics of hospital inpatients referred to a UK homeless health team: a retrospective service evaluation.

BACKGROUND: UK "Pathway" teams offer specialist hospital care coordination for people experiencing homelessness. Emergency healthcare use is high among homeless people, yet "homelessness" is not routinely coded in National Health Service (NHS) data. Pathway team records provide an opportunity to assess patterns in admissions and outcomes for inpatients identified as homeless. METHODS: Retrospective analysis of patients referred to "Pathway" homelessness teams in seven UK hospitals to explore the patterns of hospital admission, morbidity, secondary healthcare utilisation and housing status. Each patient was individually identified as experiencing homelessness. Within a six-month period, demographic data, reason for admission, morbidity, mortality and secondary care hospital usage 120-days before and 120-days after the index admission was collected. RESULTS: A total of 1009 patients were referred, resulting in 1135 admissions. Most admissions had an acute physical health need (94.9%). Co-morbid mental illness and/or substance misuse was common (55.7%). Reasons for admission included mental and behavioral disorders (overdose, alcohol withdrawal or depression, 28.3%), external causes of morbidity and mortality (assault or trauma, 18.7%), and injury, poisoning and external causes (head injury, falls and fractures, 12.4%). Unplanned Emergency Department attendances reduced after index admission and unplanned hospital admissions increased slightly. Planned admissions doubled and total bed days increased. Housing status was maintained or improved for over 60% of inpatients upon discharge. Within 12 months of index admission, 50 patients (5%) died, 15 deaths (30%) occurred during the index admission. CONCLUSIONS: Disengagement with health services is common among homeless people. Many deaths are due to treatable medical conditions (heart disease, pneumonia, cancer). Observed increases in planned admissions suggests intervention from Pathway teams facilitates necessary investigations and treatment for homeless people. Equity, parity of care, and value should be inbuilt interventions for inclusion health groups and evaluations need to move beyond simply seeking cost reductions.

Sorption of copper and phosphate to diverse biogenic iron (oxyhydr)oxide deposits.

Iron (Fe) transformations partially control the biogeochemical cycling of biologically and environmentally important elements, such as carbon (C), nitrogen (N), phosphorus (P), and trace metals. In marine and freshwater environments, iron oxidizing bacteria commonly promote the oxidation of ferrous iron (Fe(II)) at circumneutral oxic-anoxic interfaces, resulting in the formation of mineral-organic composites known as biogenic Fe(III) (oxyhydr)oxides (BIOS). Previous studies have examined the microbial ecology, composition, morphology, and sorption reactivity of BIOS. However, a broad survey of BIOS properties and sorption reactivity is lacking. To further explore these relationships, this study utilized X-ray absorption spectroscopy (XAS) to characterize the Fe mineral species, acid digestions and elemental analysis to determine composition, Brunauer-Emmett-Teller (BET) analysis to measure specific surface area, and copper (Cu) and phosphorus (P) adsorption experiments at concentrations designed to measure maximum sorption to evaluate reactivity of BIOS samples collected in lakes and streams of the North Carolina Piedmont. Sample composition varied widely, with Fe and C content ranging from 6.3 to 34% and 3.4-13%, respectively. XAS spectra were best fit with 42-100% poorly crystalline Fe (oxyhydr)oxides, with the remainder composed of crystalline Fe minerals and organic complexes. On a sorbent mass basis, Cu and P sorption varied by a factor of two and 15, respectively. Regression analyses reveal interrelationships between physicochemical properties, and suggest that differences in P binding are driven by sorption to Fe(III) (oxyhydr)oxide surfaces. In total, results suggest that the physical and chemical characteristics of organic and Fe(III) (oxyhydr)oxide phases in BIOS interplay to control the sorption of solutes, and thus influence nutrient and contaminant cycling in soil and natural waters.

Use of an educational, audiovisual podcast to maximise safety with variable rate intravenous insulin infusions.

Variable rate intravenous insulin infusions (VRIII) are used to maintain stable blood glucose in hospitalised patients with diabetes who are unable to eat or have a severe illness where good glycaemic control is paramount. With VRIII it is important to prescribe an adequate substrate to avoid hypoglycaemia and maintain electrolyte balance. Traditionally the substrate would have been varied to achieve this; current guidelines advise varying the infusion rate rather than the type of substrate. The local hospital Trust updated their VRIII prescription chart to reflect the Joint British Diabetes Societies' suggestions for inpatient care in October 2014. A local audit in January 2015 highlighted that 48% of patients on VRIII were prescribed the correct fluid as per the guideline. A questionnaire to assess prescriber knowledge regarding VRIII showed 40.4% of prescribers selected appropriate fluid for a patient with normal renal function and 11.5% of prescribers selected appropriate fluid for a patient with renal failure. An educational podcast was devised to explain the rationale behind appropriate fluid prescription with VRIII; this was shown to prescribers. Following the podcast, 75.8% of prescribers selected appropriate fluids for normal renal function and 54.5% for renal failure. Questionnaires were completed to assess prescriber knowledge prepodcast and postpodcast. Following the podcast, there was a significant increase in questionnaire scores, indicating improved prescriber knowledge surrounding VRIII. A reaudit of prescriptions for VRIII showed improvement in practice, where 63% of patients on VRIII were prescribed correct fluids. The use of a simple audiovisual podcast on VRIII led to a significant improvement in prescriber knowledge. Podcasts are an ideal medium to raise awareness around safety issues, including safe prescription of insulin. Further work will include the follow-up of participants to evaluate sustained knowledge and improvements of prescriptions in practice, with the overall aim of improving patient safety.

Reconstruction of clonal trees and tumor composition from multi-sample sequencing data.

MOTIVATION: DNA sequencing of multiple samples from the same tumor provides data to analyze the process of clonal evolution in the population of cells that give rise to a tumor. RESULTS: We formalize the problem of reconstructing the clonal evolution of a tumor using single-nucleotide mutations as the variant allele frequency (VAF) factorization problem. We derive a combinatorial characterization of the solutions to this problem and show that the problem is NP-complete. We derive an integer linear programming solution to the VAF factorization problem in the case of error-free data and extend this solution to real data with a probabilistic model for errors. The resulting AncesTree algorithm is better able to identify ancestral relationships between individual mutations than existing approaches, particularly in ultra-deep sequencing data when high read counts for mutations yield high confidence VAFs. AVAILABILITY AND IMPLEMENTATION: An implementation of AncesTree is available at: http://compbio.cs.brown.edu/software.