Delaware Longitudinal Study of Fraction Learning: Implications for Helping Children With Mathematics Difficulties

The goal of the present article is to synthesize findings to date from the Delaware Longitudinal Study of Fraction Learning. The study followed a large cohort of children ( N = 536) between Grades 3 and 6. The findings showed that many students, especially those with diagnosed learning disabilities, made minimal growth in fraction knowledge and that some showed only a basic grasp of the meaning of a fraction even after several years of instruction. Children with low growth in fraction knowledge during the intermediate grades were much more likely to fail to meet state standards on a broad mathematics measure at the end of Grade 6. Although a range of general and mathematics-specific competencies predicted fraction outcomes, the ability to estimate numerical magnitudes on a number line was a uniquely important marker of fraction success. Many children with mathematics difficulties have deep-seated problems related to whole number magnitude representations that are complicated by the introduction of fractions into the curriculum. Implications for helping students with mathematics difficulties are discussed.

Validity of the Samsung Phone S Health application for assessing steps and energy expenditure during walking and running: Does phone placement matter?

Background

The emergence of mHealth and the utilization of smartphones in physical activity interventions warrant a closer examination of validity evidence for such technology. This study examined the validity of the Samsung S Health application in measuring steps and energy expenditure.

Methods

Twenty-nine participants (mean age 21.69 ± 1.63) participated in the study. Participants carried a Samsung smartphone in their non-dominant hand and right pocket while walking around a 200-meter track and running on a treadmill at 2.24 m∙s⁻¹. Steps and energy expenditure from the S Health app were compared with StepWatch 3 Step Activity Monitor steps and indirect calorimetry.

Results

No significant differences between S Health estimated steps and energy expenditure during walking and their respective criterion measures, regardless of placement. There was also no significant difference between S Health estimated steps and the criterion measure during treadmill running, regardless of placement. There was significant differences between S Health estimated energy expenditure and the criterion during treadmill running for both placements (both p < 0.001).

Conclusions

The S Health application measures steps and energy expenditure accurately during self-selected pace walking regardless of placement. Placement of the phone impacts the S Health application accuracy in measuring physical activity variables during treadmill running.

From Precursors to Pollutants: Some Advances in Combustion Chemistry Diagnostics

The present assessment and prediction of potential pollutant emissions from combustion systems often rely on dedicated combustion models. Their validation depends on the critical examination of the relevant chemical reaction pathways. To this end, a number of combustion diagnostic techniques are available<br />which can probe important chemical constituents in situ, thus providing direct information on the progress of the combustion reactions. Here, some recent experimental advances for the investigation of a suite of targets from molecular intermediates and soot precursors to nascent particles will be presented. Examples include the application of quantum cascade laser absorption spectroscopy (QCLAS), molecular-beam mass<br />spectrometry (MBMS) with different ionization schemes, photoelectron–photoion coincidence (PEPICO) spectroscopy, helium ion microscopy (HIM), and polarization-modulated infrared reflection–absorption spectroscopy (PM-IRRAS).<br /><br />

Exploring the limit of dislocation based plasticity in nanostructured metals

A twofold decrease to an unexplored scale of 5 nm was produced in Cu by applying a large sliding load in liquid nitrogen. Statistical and universal scaling analyses of deformation induced high angle boundaries, dislocation boundaries, and individual dislocations observed by high resolution electron microscopy reveal that dislocation processes still dominate. Dislocation based plasticity continues far below the transition suggested by experiment and molecular dynamics simulations, with a limit below 5 nm. Very high strength metals may emerge based on this enhanced structural refinement.

Rapid identification of Stenotrophomonas maltophilia by peptide nucleic acid fluorescence in situ hybridization

The objective of this study was to develop a novel peptide nucleic acid (PNA) probe for Stenotrophomonas maltophilia identification by fluorescence in situ hybridization (FISH). The probe was evaluated using 33 human and veterinary clinical S. maltophilia isolates and 45 reference strains representing common bacterial species in the respiratory tract. The probe displayed 100% sensitivity and 100% specificity on pure cultures and allowed detection in sputum from cystic fibrosis patients. The detection limit was 10⁴ CFU/mL in spiked tracheal aspirate and bronchoalveolar lavage from healthy horses. Altogether the study shows that this species-specific PNA FISH probe facilitates rapid detection of S. maltophilia in biological specimens.

Hepatitis B prevalence in Denmark - an estimate based on nationwide registers and a national screening programme, as on 31 December 2007

The prevalence of chronic hepatitis B virus (HBV) infection in Denmark is not clear. The primary aim of this study was to estimate the prevalence of chronic HBV infection in Denmark. The capture–recapture method was used to estimate the total population diagnosed with chronic HBV infection in Denmark using four nationwide registers. The population with undiagnosed chronic HBV infection was estimated by incorporating data from a two-year nationwide HBsAg screening programme in pregnant women. We identified 4,466 individuals with chronic HBV infection in the four registers until the end of 2007, and the capture–recapture estimate of the total population diagnosed with chronic hepatitis B was 7,112 (95% confidence interval (CI): 6,953–10,747). Only 17% of the identified patients attended recommended clinical care according to national guidelines. Including undiagnosed patients, the current population alive with HBV infection was 10,668 (95% CI: 10,224–16,164), corresponding to a prevalence of 0.24% (95% CI: 0.23–0.37%) in the Danish population older than 15 years. The estimated prevalence of chronic HBV infection among adults in Denmark was lower than reported from other northern European countries. Only half of the infected population had been diagnosed, and a minority attended specialised clinical care.

Abstract P1-01-06: Evaluation of the stage IB designation of the 7th edition of the AJCC staging system: Biologic factors are more important

Purpose: The stage IB designation was added to the AJCC 7th edition staging system to denote micrometastasis in patients with T1 tumors. We have previously examined this group and found that receptor status and nuclear grade were better survival discriminates than the presence of micrometastases. The current study was undertaken to validate this finding in a larger cohort from the American College of Surgeons Oncology Group (ACOSOG) Z0010 study.

Methods: Clinicopathologic and outcomes data from patients enrolled on ACOSOG Z0010 were recorded. All patients underwent breast conserving surgery, sentinel lymph node biopsy and whole breast radiation for clinical T1-2, N0 breast cancer. Sentinel lymph nodes were evaluated by H&E locally and if negative, by immunohistochemistry (IHC) at a central laboratory. Patients were staged according to the 7th edition AJCC system and recurrence-free (RFS), disease-specific (DSS) and overall survival (OS) were determined using the Kaplan-Meier method and compared using the log-rank test.

Results: There were 5210 eligible and evaluable patients enrolled on ACOSOG Z0010. AJCC stage distribution was known in 4590 and included: 2849 (62.0%) stage IA, 376 (8.2%) stage IB, 878 (19.1%) stage IIA, 322 (7.0%) stage IIB, and 170 (3.7%) stage III. Median follow-up for the cohort was 9.0 years (range 0–12.6). Five and 10-year RFS, DSS and OS rates for patients with stage IA versus IB disease are shown in table 1.

[Clinical application of pain-related evoked potentials]

Pain-related evoked potentials (PREPs) represent a novel method for the evaluation of peripheral and central nociceptive pathways, e.g. in the diagnosis of small fiber neuropathy (SFN) or after therapeutic interventions for headache. Compared to contact heat-evoked and laser-evoked potentials, recording of PREPs is less stressful for the subjects and technically less demanding. The clinical usefulness of PREPs has been described for SFN associated with diabetes, HIV and hepatitis C infections as well as in headache and facial pain disorders. They have also been evaluated after interventional methods, such as direct current stimulation (tDCS). The article reviews and discusses the advantages and pitfalls of this technique in the context of recent clinical studies as compared to other paradigms of peripheral electrical stimulation and delineates perspectives and possible indications.

SOCS2 is dispensable for BCR/ABL1-induced chronic myeloid leukemia-like disease and for normal hematopoietic stem cell function

Suppressor of cytokine signaling 2 (SOCS2) is known as a feedback inhibitor of cytokine signaling and is highly expressed in primary bone marrow (BM) cells from patients with chronic myeloid leukemia (CML). However, it has not been established whether SOCS2 is involved in CML, caused by the BCR/ABL1 fusion gene, or important for normal hematopoietic stem cell (HSC) function. In this study, we demonstrate that although Socs2 was found to be preferentially expressed in long-term HSCs, Socs2-deficient HSCs were indistinguishable from wild-type HSCs when challenged in competitive BM transplantation experiments. Furthermore, by using a retroviral BCR/ABL1-induced mouse model of CML, we demonstrate that SOCS2 is dispensable for the induction and propagation of the disease, suggesting that the SOCS2-mediated feedback regulation of the JAK/STAT pathway is deficient in BCR/ABL1-induced CML.

[Antiepileptic drug-induced encephalopathy]

The clinical features of an antiepileptic drug-induced encephalopathy (ADE) are confusion, reduction of vigilance, neurological deficits or an increase of the seizure frequency. In the electroencephalogram a general slowing or epileptic discharges are found. Characteristic are non-toxic blood levels of the antiepileptic drugs. So far an ADE was reported under phenytoin, carbamazepine or valproatic acid (valproate) therapy. More seldom, an ADE has been described after the intake of vigabatrine, lamotrigine und topiramate. Potential pathogenic mechanisms of AED are hyperammonemia, intrinsic effects on cerebral receptors, drug interactions, hepatic enzyme interactions, metabolic reasons or paradoxical proconvulsive effects of antiepileptic drugs. The medicamentous therapy consists of an immediate discontinuation of the antiepileptic drug.