Preservice Teachers’ Algebraic Reasoning and Symbol Use on a Multistep Fraction Word Problem

Previous research on preservice teachers’ understanding of fractions and algebra has focused on one or the other. To extend this research, we examined 85 undergraduate elementary education majors and middle school mathematics education majors’ solutions and solution paths (i.e., the ways or methods in which preservice teachers solve word problems) when combining fractions with algebra on a multistep word problem. In this article, we identify and describe common strategy clusters and approaches present in the preservice teachers’ written work. Our results indicate that preservice teachers’ understanding of algebra include arithmetic methods, proportions, and is related to their understanding of a whole

Preservice teachers’ pictorial strategies for a multistep multiplicative fraction problem

Previous research has documented that preservice teachers (PSTs) struggle with under- standing fraction concepts and operations, and misconceptions often stem from their understanding of the referent whole. This study expands research on PSTs’ understanding of wholes by investigating pictorial strategies that 85 PSTs constructed for a multistep fraction task in a multiplicative context. The results show that many PSTs were able to construct valid pictorial strategies, and the strategies were widely diverse with respect to how they made sense of an unknown referent whole of a fraction in multiple steps, how they represented the wholes in their drawings, in which order they did multiple steps, and which type of model they used (area or set). Based on their wide range of pictorial strategies, we discuss potential benefits of PSTs’ construction of their own representations for a word problem in developing problem solving skills

Socioeconomic Status and Medical Care Expenditures in Medicare Managed Care

This study examined the effects of education, income, and wealth on medical care expenditures in two Medicare managed care plans. The study also sought to elucidate the pathways through which socioeconomic status (SES) affects expenditures, including preferences for health and medical care and ability to navigate the managed care system. We modeled the effect of SES on medical care expenditures using Generalized Linear Models, estimating separate models for each component of medical expenditures: inpatient, outpatient, physician, and other expenditures. We found that education, income, and wealth all affected medical care expenditures, although the effects of these variables differed across expenditure categories. Moreover, the effects of these SES variables were much smaller than the effects found in earlier studies of fee-for-service Medicare. The pathway variables also were associated with expenditures. Accounting for the pathways through which SES affects expenditures narrowed the effect of SES on expenditures; however, the change in the estimates was very small. Thus, although our measures of preferences and ability to navigate the system were associated with expenditures, they did not account for an appreciable share of the impact of SES on expenditures.

Meconium in the Amniotic Fluid of Pregnancies Complicated by Preterm Premature Rupture of Membranes Is Associated With Early Onset Neonatal Sepsis

Objective: This study was to determine the significance of meconium in the amniotic fluid of pregnancies complicated by preterm premature rupture of membranes (PPROM) without labor

Toe Pressure and Toe Brachial Index are Predictive of Cardiovascular Mortality, Overall Mortality, and Amputation Free Survival in Patients with Peripheral Artery Disease

Objective/Background: Peripheral haemodynamic parameters are used to assess the presence and severity of peripheral artery disease (PAD). The prognostic value of ankle brachial index (ABI) has been thoroughly delineated. Nonetheless, the relative usefulness of ankle pressure (AP), ABI, toe pressure (TP), and toe brachial index (TBI) in assessing patient outcome has not been investigated in a concurrent study setting. This study aimed to resolve the association of all four non-invasive haemodynamic parameters in clinically symptomatic patients with PAD with cardiovascular mortality, overall mortality, and amputation free survival (AFS). Methods: In total, 732 symptomatic patients with PAD admitted to the Department of Vascular Surgery for conventional angiography at Turku University Hospital, Turku, Finland, between January 2009 and August 2011 were reviewed retrospectively. Demographic factors, cardiovascular mortality, all-cause mortality, and above foot level amputations were obtained and assessed in relation to AP, ABI, TP, and TBI by means of Kaplan-Meier life tables and a multivariate Cox regression model. Results: The haemodynamic parameter that was associated with poor 36 month general outcome was TP <30 mmHg. Univariate Cox regression analysis of stratified values showed that TP and TBI associated significantly with mortality. In multivariate analysis both TP and TBI were associated with a significant risk of death. For TP <30 mmHg and TBI <0.25 the risk of cardiovascular mortality was hazard ratio [HR] 2.84, 95% confidence interval [CI] 1.75-4.61 [p Conclusion: Among non-invasive haemodynamic measurements and pressure indices both TP and TBI appear to be associated with cardiovascular and overall mortality and AFS for patients with PAD presenting symptoms of the disease. (C) 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Atypical periosteal osteoid osteoma: a case report

Osteoid osteoma is a benign osteoblastic tumor usually seen in adolescent and young males. In the paediatric age group, since the history may be difficult to elicit, there are often problems in early diagnosis. The author reports an unusual presentation of osteoid osteoma in a ten-year-old girl, which could not be diagnosed by conventional X-rays and CT scan

The inhibition of \u3cem\u3eStaphylococcus epidermidis\u3c/em\u3e biofilm formation by vancomycinmodified titanium alloy and implications for the treatment of periprosthetic infection

Peri-prosthetic infections are notoriously difficult to treat as the biomaterial implant is ideal for bacterial adhesion and biofilm formation, resulting in decreased antibiotic sensitivity. Previously, we reported that vancomycin covalently attached to a Ti alloy surface (Vanc-Ti) could prevent bacterial colonization. Herein we examine the effect of this Vanc-Ti surface on Staphylococci epidermidis, a Gram-positive organism prevalent in orthopaedic infections. By direct colony counting and fluorescent visualization of live bacteria, S. epidermidis colonization was significantly inhibited on Vanc-Ti implants. In contrast, the gram-negative organism Escherichia coli readily colonized the Vanc-Ti rod, suggesting retention of antibiotic specificity. By histochemical and SEM analysis, Vanc-Ti prevented S. epidermidis biofilm formation, even in the presence of serum. Furthermore, when challenged multiple times with S. epidermidis, Vanc-Ti rods resisted bacterial colonization. Finally, when S. epidermidis was continuously cultured in the presence of Vanc-Ti, the bacteria maintained a Vanc sensitivity equivalent to the parent strain. These findings indicate that antibiotic derivatization of implants can result in a surface that can resist bacterial colonization. This technology holds great promise for the prevention and treatment of periprosthetic infections