STEM education is present in most recent curriculum reforms around the world. One of the main novelties of this educational movement is the integration of engineering practices into science ...education. In the Spanish educational context, this implies an important challenge for science teachers. So, this study analyzes whether secondary science teachers are sufficiently prepared for this purpose, as well as to find out their experiences, emotions, and appraisals in this regard. To this end, a questionnaire was designed and administered to 328 secondary science teachers as a representative sample of science teachers in Spain with a confidence level of just over 93%. The reliability of the questionnaire was evidenced by the high degree of internal consistency of the data (
α
= 0.88). And its validity was determined by means of an exploratory factor analysis. The results reveal that secondary science teachers, in general, have low levels of pedagogical preparation and self-efficacy to integrate engineering practices into science classes, as well as a predominant emotion of insecurity about it. There is also a strong preference among teachers for this to be done in technology subjects. It is concluded that the effective integration of engineering practices into science education is currently a complex challenge that requires ad hoc teacher training plans.
ABSTRACT
Using light curves with ∼3 min cadence and a duration of 2 h made using the OmegaWhite survey, we present the results of a search for short-period variable stars in the field of 20 open ...clusters. We identified 92 variable stars in these fields. Using a range of cluster member catalogues and Gaia EDR3 data, we have determined that 10 are cluster members and 2 more are probable members. Based on their position on the Gaia HRD and their photometric periods, we find that most of these are δ Sct stars. We obtained low-resolution optical spectroscopy of some of these cluster members and field stars. We discuss the cluster variable stars in the context of δ Sct stars in other open clusters.
Background: There is a growing interest in investigating attitudes towards science and views of Nature of Science among elementary grade students in terms of gender, cultural backgrounds, and grade ...level variables.
Purpose: The purpose of this study is to examine the attitudes toward science and views of Nature of Science among Spanish students, Spanish students of gypsy ethnicity and second-generation Spanish students with east-European heritage, and to determine if their attitudes are related to their views of Nature of Science.
Sample: Data for this study was gathered from seven elementary schools in Spain, forming a convenience sample of 149 students enrolled from 2nd to 5th grade.
Design and Methods: The Nature of Science Instrument (NOSI) and an adaptation of the Test of Science Related Attitudes scale (TOSRA) were used. Follow-up structured interviews were performed with 15 participants.
Results: Regarding gender, boys had better attitudes toward Science than girls but more naïve views of the empirical Nature of Science. In relation to cultural background, second generation Spanish students with east-European heritage reported significantly better attitudes toward Science than Spanish students and Spanish students of gypsy ethnicity. No differences in Nature of Science views were found. Concerning grade level, third graders had more positive attitudes toward Science than fifth and sixth graders and more informed views of the tentative Nature of Science. Finally, no relation between Nature of Science views and attitudes towards Science were identified.
Conclusion: This study stress the need to address the steady decline in positive attitude toward Science and to improve students' views of Nature of Science from early elementary grades, and to use gender and culturally inclusive science teaching strategies.
We present the goals, strategy and first results of the OmegaWhite survey: a wide-field high-cadence g-band synoptic survey which aims to unveil the Galactic population of short-period variable stars ...(with periods <80 min), including ultracompact binary star systems and stellar pulsators. The ultimate goal of OmegaWhite is to cover 400 deg2 along the Galactic plane reaching a depth of g = 21.5 mag (10σ), using OmegaCam on the VLT Survey Telescope (VST). The fields are selected to overlap with surveys such as the Galactic Bulge Survey and the VST Photometric Hα Survey of the Southern Galactic Plane for multiband colour information. Each field is observed using 38 exposures of 39 s each, with a median cadence of ∼2.7 min for a total duration of two hours. Within an initial 26 deg2, we have extracted the light curves of 1.6 million stars, and have identified 613 variable candidates which satisfy our selection criteria. Furthermore, we present the light curves and statistical properties of 20 sources which have the highest likelihood of being variable stars. One of these candidates exhibits the colours and light-curve properties typically associated with ultracompact AM CVn binaries, although its spectrum exhibits weak Balmer absorption lines and is thus not likely to be such a binary system. We also present follow-up spectroscopy of five other variable candidates, which identifies them as likely low-amplitude δ Sct pulsating stars.
Resveratrol in the fruits of bilberry (Vaccinium myrtillus L.), the lowbush “wild” blueberry (Vaccinium angustifolium Aiton), the rabbiteye blueberry (Vaccinium ashei Reade), and the highbush ...blueberry (Vaccinium corymbosum L.) were measured using a new assay based on high-performance liquid chromatography−tandem mass spectrometry (LC-MS/MS). The LC-MS/MS assay provided lower limits of detection than previous methods for resveratrol measurement, 90 fmol of trans-resveratrol injected on-column, and a linear standard curve spanning >3 orders of magnitude. The recoveries of resveratrol from blueberries spiked with 1.8, 3.6, or 36 ng/g were 91.5 ± 4.5, 95.6 ± 6.5, and 88.0 ± 3.6%, respectively. trans-Resveratrol but not cis-resveratrol was detected in both blueberry and bilberry samples. The highest levels of trans-resvertatrol in these specimens were 140.0 ± 29.9 pmol/g in highbush blueberries from Michigan and 71.0 ± 15.0 pmol/g in bilberries from Poland. However, considerable regional variation was observed; highbush blueberries from British Columbia contained no detectable resveratrol. Because blueberries and bilberries are often consumed after cooking, the effect of baking on resveratrol content was investigated. After 18 min of heating at 190 °C, between 17 and 46% of the resveratrol had degraded in the various Vaccinium species. Therefore, the resveratrol content of baked or heat-processed blueberries or bilberries should be expected to be lower than in the raw fruit. Although blueberries and bilberries were found to contain resveratrol, the level of this chemoprotective compound in these fruits was <10% that reported for grapes. Furthermore, cooking or heat processing of these berries will contribute to the degradation of resveratrol. Keywords: Blueberry; bilberry; Vaccinium sp.; resveratrol; mass spectrometry; LC-MS/MS
We report the discovery of the ultracompact hot subdwarf (sdOB) binary OW J074106.0-294811.0 with an orbital period of minutes, making it the most compact hot subdwarf binary known. Spectroscopic ...observations using the VLT, Gemini and Keck telescopes revealed a He-sdOB primary with an intermediate helium abundance, = K and = 5.74 0.09. High signal-to-noise ratio light curves show strong ellipsoidal modulation resulting in a derived sdOB mass with a WD companion ( ). The mass ratio was found to be . The derived mass for the He-sdOB is inconsistent with the canonical mass for hot subdwarfs of . To put constraints on the structure and evolutionary history of the sdOB star we compared the derived , , and sdOB mass to evolutionary tracks of helium stars and helium white dwarfs calculated with Modules for Experiments in Stellar Astrophysics (MESA). We find that the best-fitting model is a helium white dwarf with a mass of 0.320 , which left the common envelope ago, which is consistent with the observations. As a helium white dwarf with a massive white dwarf companion, the object will reach contact in 17.6 Myr at an orbital period of 5 minutes. Depending on the spin-orbit synchronization timescale the object will either merge to form an R CrB star or end up as a stably accreting AM CVn-type system with a helium white dwarf donor.
The incidence of kidney stones in children has increased in recent years. Unlike adults, the treatment of pediatric kidney stones is more difficult because of the size of the stones and the high risk ...of recurrence.
The present study aimed to evaluate the management of pediatric kidney stones with percutaneous nephrolithotomy in general and with both types of percutaneous nephrolithotomy (PCNL).
Methods. This retrospective cross-sectional study was conducted at Al-Safeer Al-Imam Al-Hussein Hospital from November 1, 2019 to October 31, 2021. A total of 90 children with kidney stones were divided into 45 with tubular PCNL and 45 with tubeless PCNL. The children were followed up for at least six months postoperatively.
Results. After PCNL, only 4 children were not stone-free and no injury was noted, whereas sepsis was noted in only one child. Renal status after PCNL was stable renal function in 97.8% of children and improved renal function in 2.2% of children, while no deterioration of renal function was noted. The characteristics of the children, the characteristics of the surgical procedure (except access), and the results of PCNL were not significantly different among the different types of PCNL
Conclusion. PCNL in both variants (with and without tubing) is a safe and effective surgical option in the treatment of children with renal stones.
OmegaWhite is a wide-field, high cadence, synoptic survey targeting fields in the southern Galactic plane, with the aim of discovering short period variable stars. Our strategy is to take a series of ...39 s exposures in the g band of a 1 deg2 of sky lasting 2 h using the OmegaCAM wide field imager on the VLT Survey Telescope (VST). We give an overview of the initial 4 yr of data which covers 134 deg2 and includes 12.3 million light curves. As the fields overlap with the VLT Survey Telescope Hα Photometric Survey of the Galactic plane and Bulge (VPHAS+), we currently have ugriHα photometry for ∼1/3 of our fields. We find that a significant fraction of the light curves have been affected by the diffraction spikes of bright stars sweeping across stars within a few dozen of pixels over the two hour observing time interval due to the alt-az nature of the VST. We select candidate variable stars using a variety of variability statistics, followed by a manual verification stage. We present samples of several classes of short period variables, including: an ultra compact binary, a DQ white dwarf, a compact object with evidence of a 100 min rotation period, three CVs, one eclipsing binary with an 85 min period, a symbiotic binary which shows evidence of a 31 min photometric period, and a large sample of candidate δ Sct type stars including one with a 9.3 min period. Our overall goal is to cover 400 deg2, and this study indicates we will find many more interesting short period variable stars as a result.
Passion fruits are nutritious for fresh and industrial consumption. Insect pests, such as defoliating caterpillars, including Dione juno juno (Lepidoptera: Nymphalidae), defoliate completely ...Passiflora spp. plants (Passifloraceae) at high population densities. Biological control is an environmentally safe method to manage harmful arthropods. Parasitoid insects are known for their effectiveness and specificity as biological control agents and they are mainly of the Diptera and Hymenoptera orders. Here, Pinheiro et al report the first record of Brachymeria koehleri (Hymenoptera: Chalcididae) as a hyperparasitoid in D. juno juno pupae trough C. aff. scutellaris.
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