To FRA or not to FRA: what is the question for science education?

Nine years after reconceptualizing the nature of science for science education using the family resemblance approach (FRA) (Erduran & Dagher, 2014a), the time is ripe for taking stock of what this approach has accomplished, and what future research it can facilitate. This reflective paper aims to accomplish three goals. The first addresses several questions related to the FRA for the purpose of ensuring that the applications of FRA in science education are based on robust understanding of the framework. The second discusses the significance of the FRA by highlighting its capacity to support science educators with the exploration of a wide range of contemporary issues that are relevant to how teachers and learners perceive and experience science. The third goal of the paper offers recommendations for future directions in FRA research in the areas of science identity development and multicultural education as well as curriculum, instruction, and assessment in science education

Design of unit testing using xUnit.net

© 2014 IEEE. This paper presents an in-depth study of designing, implementing and executing unit test cases using the xUnit.net testing tool in general and in the context of the TeleMedicine Cluster System project within the ICT Design subject delivered at UTS, Australia. The case studies are based on the utilisation of the tool in Visual Basic 2012 using the.NET framework for C#. The paper elucidates on how and why the xUnit framework can be applied in the context of the TMC system, and how it can be tailored to meet the testing ad integration needs of the delivery of TMC system

Al_5+αSi_5+δN₁₂, a new Nitride compound

The family of III-Nitride semiconductors has been under intensive research for almost 30 years and has revolutionized lighting applications at the dawn of the 21st century. However, besides the developments and applications achieved, nitride alloys continue to fuel the quest for novel materials and applications. We report on the synthesis of a new nitride-based compound by using annealing of AlN heteroepitaxial layers under a Si-atmosphere at temperatures between 1350 °C and 1550 °C. The structure and stoichiometry of this compound are investigated by high resolution transmission electron microscopy (TEM) techniques and energy dispersive X-Ray (EDX) spectroscopy. Results are supported by density functional theory (DFT) calculations. The identified structure is a derivative of the parent wurtzite AlN crystal where the anion sublattice is fully occupied by N atoms and the cation sublattice is the stacking of 2 different planes along lt;0001gt;: The first one exhibits a ×3 periodicity along lt;11–20gt; with 1/3 of the sites being vacant. The rest of the sites in the cation sublattice are occupied by an equal number of Si and Al atoms. Assuming a semiconducting alloy, a range of stoichiometries is proposed, Al5+αSi5+δN12 with α being between −2/3 and 1/4 and δ between 0 and 3/4. © 2019, The Author(s)

Rate of Freeze Impacts the Survival and Immune Responses Post Cryoablation of Melanoma.

The emergence of ablative therapies has revolutionized the treatment of inoperable solid tumors. Cryoablation stands out for its uniqueness of operation based on hypothermia, and for its ability to unleash the native tumor antigens, resulting in the generation of anti-tumor immune responses. It is not clearly understood how alterations in the rate of freeze impact the immune response outcomes. In this study, we tested fast freeze and slow freeze rates for their locoregional effectiveness and their ability to elicit immune responses in a B16F10 mouse model of melanoma. Tumor bearing mice treated with fast freeze protocol survived better than the ones treated with slow freeze protocol. Fast freeze resulted in a higher magnitude of CD4 <sup>+</sup> and CD8 <sup>+</sup> T-cell responses, and a significantly extended survival post re-challenge. Thus, fast freeze rate should be applied in any future studies employing cryoablation as an in vivo vaccination tool in conjunction with targeted immunotherapies

Descriptive analysis of sepsis in a developing country

BACKGROUND: Most studies on sepsis were conducted in developed countries. The aim of this study is to report on a series of patients with sepsis in a tertiary hospital in a developing country. METHODS: Patients admitted through the emergency department of a single university-based institution between January 2008 and June 2012, with a final diagnosis of sepsis, bacteremia, or septic shock, were retrieved. A sample of 97 patients was selected. Vital signs at presentation, number of SIRS criteria, use of vasopressors and steroids, and in-hospital mortality were recorded. RESULTS: The mean age was 70.09 ± 16.82, ranging from 19 to 96 years; 48.5 % were females and 51.5 % were males; 42.3 % of the patients were found to be bacteremic. IV fluid requirement during the first 6 h was 1.75 ± 1.96 l. The time for antibiotic initiation was 3.43 ± 4.48 h, with 87.6 % of the antibiotics initiated in the emergency department. Norepinephrine was the most commonly used vasopressor (38.1 %) followed by dopamine (8.2 %), and the inotrope dobutamine (4.1 %); 45.3 % of the patients were admitted to the intensive care unit (ICU), and the remaining 54.7 % were managed on the general practice unit (GPU). A total of 30 (30.9 %) septic patients died. The 28-day mortality was 20.6 %. Deceased patients had greater vasopressor use, a longer stay in the ICU (p = 0.001), and a longer time to norepinephrine use (p = 0.004). CONCLUSIONS: This is the first study providing an in-depth analysis of sepsis patients in a developing country, looking at in-hospital mortality, SIRS criteria utility, and at the overall sepsis management.Gilbert Abou Dagher, Mothana Saadeldine, Rana Bachir, Dina Zebian and Ralphe Bou Cheb

Multivariate analysis reveals shared genetic architecture of brain morphology and human behavior.

Human variation in brain morphology and behavior are related and highly heritable. Yet, it is largely unknown to what extent specific features of brain morphology and behavior are genetically related. Here, we introduce a computationally efficient approach for multivariate genomic-relatedness-based restricted maximum likelihood (MGREML) to estimate the genetic correlation between a large number of phenotypes simultaneously. Using individual-level data (N = 20,190) from the UK Biobank, we provide estimates of the heritability of gray-matter volume in 74 regions of interest (ROIs) in the brain and we map genetic correlations between these ROIs and health-relevant behavioral outcomes, including intelligence. We find four genetically distinct clusters in the brain that are aligned with standard anatomical subdivision in neuroscience. Behavioral traits have distinct genetic correlations with brain morphology which suggests trait-specific relevance of ROIs. These empirical results illustrate how MGREML can be used to estimate internally consistent and high-dimensional genetic correlation matrices in large datasets

Ferroxitosis: a cell death from modulation of oxidative phosphorylation and PKM2-dependent glycolysis in melanoma

Reliance on glycolysis is a characteristic of malignancy, yet the development of resistance to BRAF inhibitors in melanoma is associated with gain of mitochondrial function. Concurrent attenuation of oxidative phosphorylation and HIF-1α/PKM2-dependent glycolysis promotes a non-apoptotic, iron- and oxygen-dependent cell death that we term ferroxitosis. The redox cycling agent menadione causes a robust increase in oxygen consumption, accompanied by significant loss of intracellular ATP and rapid cell death. Conversely, either hypoxic adaptation or iron chelation prevents menadione-induced ferroxitosis. Ectopic expression of K213Q HIF-1α mutant blunts the effects of menadione. However, knockdown of HIF-1α or PKM2 restores menadione-induced cytotoxicity in hypoxia. Similarly, exposure of melanoma cells to shikonin, a menadione analog and a potential PKM2 inhibitor, is sufficient to induce ferroxitosis under hypoxic conditions. Collectively, our findings reveal that ferroxitosis curtails metabolic plasticity in melanoma