Scratch for Budding Computer Scientists

Scratch is a "media-rich programming environment" recently developed by MIT's Media Lab that "lets you create your own animations, games, and interactive art." Although Scratch is intended to "enhance the development of technological fluency [among youths] at after-school centers in economically disadvantaged communities," we find rarkable potential in this programming environment for higher education as well.We propose Scratch as a first language for first-time programmers in introductory courses, for majors and non-majors alike. Scratch allows students to program with a mouse: programmatic constructs are represented as puzzle pieces that only fit together if "syntactically" appropriate. We argue that this environment allows students not only to master programmatic constructs before syntax but also to focus on probls of logic before syntax. We view Scratch as a gateway to languages like Java.To validate our proposal, we recently deployed Scratch for the first time in higher education via harvard Summer School's Computer Science S-1: Great Ideas in Computer Science, the summertime version of a course at harvard College. Our goal was not to improve scores but instead to improve first-time programmers' experiences. We ultimately transitioned to Java, but we first introduced programming itself via Scratch. We present in this paper the results of our trial.We find that, not only did Scratch excite students at a critical time (i.e.,, their first foray into computer science), it also familiarized the inexperienced among the with fundamentals of programming without the distraction of syntax. Moreover, when asked via surveys at term's end to reflect on how their initial experience with Scratch affected their subsequent experience with Java, most students (76%) felt that Scratch was a positive influence, particularly those without prior background. Those students (16%) who felt that Scratch was not an influence, positive or negative, all had prior programming experience.Engineering and Applied Science

Multidissiplinêre beskouinge op veroudering vanuit ‘n pastorale perspektief

Multiprofessional aspects of ageing seen from a pastoral perspectiveThis article describes existing research on gerontology, and explores the role of pastoral care. When focusing on gerontology from a pastoral care point of view, certain multiprofessional aspects need to be considered. The article aims to highlight insights on the subject from the fi eld of sociology,and to enable pastors to engage meaningfully with elderly persons. Refl ection on the changing social environment emphasises the diffi culties that retirement and the resulting loss of authenticity pose to the older person. The article considers how pastoral care as part of a multidisciplinary teamcould fulfi l a positive role in gerontology

Search Engine Advertising: Channel Substitution when Pricing Ads to Context

We explore substitution patterns across advertising platforms. Using data on the advertising prices paid by lawyers for 139 Google search terms in 195 locations, we exploit a natural experiment in “ambulance-chaser” regulations across states. When lawyers cannot contact clients by mail, advertising prices per click for search engine advertisements are 5%–7% higher. Therefore, online advertising substitutes for offline advertising. This substitution toward online advertising is strongest in markets with fewer customers, suggesting that the relationship between the online and offline media is mediated by the marketers' need to target their communications.NET Institut

Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes

Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.Comment: To be published in At. Data Nucl. Data Table

Hydrogen Epoch of Reionization Array (HERA)

The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn ($z\sim30$). During these epochs, early stars and black holes heated and ionized the IGM, introducing fluctuations in 21 cm emission. HERA is designed to characterize the evolution of the 21 cm power spectrum to constrain the timing and morphology of reionization, the properties of the first galaxies, the evolution of large-scale structure, and the early sources of heating. The full HERA instrument will be a 350-element interferometer in South Africa consisting of 14-m parabolic dishes observing from 50 to 250 MHz. Currently, 19 dishes have been deployed on site and the next 18 are under construction. HERA has been designated as an SKA Precursor instrument. In this paper, we summarize HERA's scientific context and provide forecasts for its key science results. After reviewing the current state of the art in foreground mitigation, we use the delay-spectrum technique to motivate high-level performance requirements for the HERA instrument. Next, we present the HERA instrument design, along with the subsystem specifications that ensure that HERA meets its performance requirements. Finally, we summarize the schedule and status of the project. We conclude by suggesting that, given the realities of foreground contamination, current-generation 21 cm instruments are approaching their sensitivity limits. HERA is designed to bring both the sensitivity and the precision to deliver its primary science on the basis of proven foreground filtering techniques, while developing new subtraction techniques to unlock new capabilities. The result will be a major step toward realizing the widely recognized scientific potential of 21 cm cosmology.Comment: 26 pages, 24 figures, 2 table

How does gender influence the recognition of cardiovascular risk and adherence to self-care recommendations? : a study in polish primary care

Background: Studies have shown a correlation between gender and an ability to change lifestyle to reduce the risk of disease. However, the results of these studies are ambiguous, especially where a healthy lifestyle is concerned. Additionally, health behaviors are strongly modified by culture and the environment. Psychological factors also substantially affect engagement with disease-related lifestyle interventions. This study aimed to examine whether there are differences between men and women in the frequency of health care behavior for the purpose of reducing cardiovascular risk (CVR), as well as cognitive appraisal of this type of risk. We also aimed to identify the psychological predictors of engaging in recommended behavior for reducing the risk of cardiovascular disease after providing information about this risk in men and women. Methods: A total of 134 consecutive eligible patients in a family practice entered a longitudinal study. At initial consultation, the individual’s CVR and associated health burden was examined, and preventive measures were recommended by the physician. Self-care behavior, cognitive appraisal of risk, and coping styles were then assessed using psychological questionnaires. Six months after the initial data collection, the frequency of subjects’ self-care behavior was examined. Results: We found an increase in health care behavior after providing information regarding the rate of CVR in both sexes; this increase was greater for women than for men. Women followed self-care guidelines more often than men, particularly for preventive measures and dietary advice. Women were more inclined to recognize their CVR as a challenge. Coping style, cognitive appraisal, age, level of health behaviors at baseline and CVR values accounted for 48% of the variance in adherence to self-care guidelines in women and it was 52% in men. In women, total risk of CVD values were most important, while in men, cognitive appraisal of harm/loss was most important. Conclusions: Different predictors of acquisition of health behavior are encountered in men and women. Our results suggest that gender-adjusted motivation models influencing the recognition process need to be considered to optimize compliance in patients with CVR

Comparative gender analysis of the efficacy and safety of atazanavir/ritonavir and lopinavir/ritonavir at 96 weeks in the CASTLE study.

OBJECTIVES: To examine whether the overall results of the CASTLE study pertain to both genders, we analysed the efficacy and safety of atazanavir/ritonavir and lopinavir/ritonavir in 277 female and 606 male patients in the open-label, multinational trial over 96 weeks. The trial is registered with ClinicalTrials.gov, number NCT00272779. METHODS: Treatment-naive patients aged ≥ 18 years with HIV-1 RNA ≥ 5000 copies/mL were randomized to receive either atazanavir/ritonavir 300/100 mg once daily or lopinavir/ritonavir 400/100 mg twice daily, with fixed-dose tenofovir/emtricitabine 300/200 mg once daily. RESULTS: At week 96, confirmed virological response rates (HIV RNA \u3c50 copies\u3e/mL; intent-to-treat analysis) were higher in women and men receiving atazanavir/ritonavir than those receiving lopinavir/ritonavir and lower in women than men in both treatment arms (67% of women and 77% of men on atazanavir/ritonavir and 63% of women and 71% of men on lopinavir/ritonavir). These differences were not observed in the on-treatment analysis. Mean change in CD4 cell count from baseline to week 96 was 265 cells/mm(3) for women and 269 cells/mm(3) for men on atazanavir/ritonavir and 298 cells/mm(3) for women and 286 cells/mm(3) for men on lopinavir/ritonavir. Discontinuation rates were higher in women than men in each treatment arm (22% of women and 15% of men on atazanavir/ritonavir and 29% of women and 18% of men on lopinavir/ritonavir). In women and men, grade 2-4 nausea and diarrhoea were more frequent in the lopinavir/ritonavir group; jaundice and hyperbilirubinaemia occurred more frequently in the atazanavir/ritonavir group. CONCLUSIONS: Once-daily atazanavir/ritonavir is an effective and well-tolerated therapeutic option for women and men with HIV-1 infection. The sex-based differences in response may be due to higher discontinuation rates in women

Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure

Erratum

Original article: Day JA, Malan HL, Malijani E and Abegunde AP (2019) Water quality in non-perennial rivers. Water SA 45 (3) 487–500. https://doi.org/10.17159/ wsa/2019.v45.i3.6746 How to cite: Erratum: Water quality in non-perennial rivers. [Water SA 45 (3) 487–500]. Water SA 46 (2) 330–344. https://doi.org/10.17159/wsa.2020.v46i2.825