Can you Master This? : Initial Attempts at Specifications-based Grading in Introductory Chemistry

The Illinois Mathematics and Science Academy (IMSA) requires all incoming students to complete a one-semester introductory chemistry course in their sophomore year – Scientific Inquiries in Chemistry (SI-Chem). This course has historically been taught using a traditional grading/assessment model, however, in the Spring of 2021, a switch was made to a specification-based grading system. One motivating factor in this decision is an institutional shift to an equity-focused grading approach, and an analysis of our historical assessment model indicated areas for improvement. Our initial foray into specifications grading was during the Spring of 2021 semester, when all of our courses were taught synchronously via Zoom. During the return to in-person learning in the Fall of 2021, we continued utilizing the same model of specification grading. Throughout this shift, none of the course objectives, in-class delivery or activities were changed, except where necessitated by the online vs in-person format. The poster will explain the design approach in our specifications grading system in both formats, the main challenges and benefits of utilizing this new assessment model, impact on student grades, and the major takeaways moving forward

VISUALIZATION TOOLS AND ANALOGIES TO MODEL STRONG VS. WEAK ACIDS

We will present two different ways to introduce the difference between a strong acid and a weak acid. The first one uses a Phet simulation where the students can change different parameters in an inquiry based approach. The second one is a hands-on activity using a guided packet and manipulatives to model the differences between strong and weak acids. Attendees must bring a computer

Discussion Board Ideas for High School Science

This session will share some ideas for bringing online discussion board assignments into your classroom. We will share a few examples of assignments including components such as infographics, diversity and equity, and intermolecular forces, as well as give ideas for how to transition a traditional assignment into a discussion board assignment. Feel free to bring examples of discussion board assignments that have worked for you, and/or an assignment that you would like to transition into a discussion board assignment

Elements of oxidation/reduction balance in experimental hypothyroidism

Background: The aim of this study was to investigate the effect of the decreased level of thyroid hormones on selected parameters of the oxidation/reduction balance by assessing the activity of antioxidant enzymes: superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px); the level of antioxidant vitamins (A, C, and E); and the concentration of compounds reacting with thiobarbituric acid (TBARS). Material and methods: Investigations involved 20 Belgian giant rabbits of both sexes. Hypothyroidism was induced by intragastric administration of thiamizole. Before this was done, blood was collected from the ear marginal vein (control group) and then the animals received thiamizole through an intragastric tube at a dose of 2 mg/kg b.w. for 21 days. Blood was collected again (the experimental group) and the following determinations were performed: — in blood serum, the thyroid hormones T3, T4 and TSH; — vitamin A, C and E blood serum concentrations; — in erythrocytes, the concentration of compounds reacting with TBARS, SOD and GSH-Px. Results: A 21-day exposure of rabbits to thiamazole (2 mg/kg b.w./24 h) resulted in a statistically significant decrease of TBARS, a decrease of SOD and GPH-Px activity and in a statistically insignificant decrease in the level of vitamins A, C and E. Conclusions: Hypothyroidism decreases the level of erythrocytes oxidation/reduction balance by diminishing oxidative lipids damage and by decreasing the activity of antioxidative enzymes, but not by changes in the level of antioxidant vitamins. (Pol J Endocrinol 2011; 62 (3): 220–223)Wstęp: Celem badania była ocena wpływu zmniejszenia stężenia hormonów tarczycy na wybrane parametry równowagi oksydacyjno-redukcyjnej przez badanie aktywności enzymów antyoksydacyjnych ( SOD, GSH-Px), stężenia witamin antyoksydacyjnych (A, C, E) oraz związków reagujących z kwasem tiobarbiturowym (TBARS). Materiał i metody: Badania przeprowadzono na 40 królikach rasy olbrzym beligijski, obojga płci. Niedoczynność tarczycy wywołano dożołądkowym podawaniem thiamazolu. Przed podaniem thiamazolu pobrano krew żylną (grupa kontrolna), a następnie przez 21 dni zwierzęta otrzymywały dożołądkowo thiamazol w dawce 2 mg/kg mc. Po tym czasie ponownie pobierano krew (grupa badana) i oznaczano: — stężenie hormonów tarczycy T3, T4 i TSH; — stężenie witamin A, C i E w surowicy; — stężenie związków reagujących z kwasem tiobarbiturowym (TBARS) i aktywność dysmutazy ponadtlenkowej (SOD) i peroksydazy glutationowej (GPH-Px) w erytrocytach. Wyniki: Po 21 dniach dożołądkowego podawania królikom thiamazolu (2 mg/kg mc./24 h) stwierdzono statystycznie znamienne zmniejszenie stężenia TBARS, obniżenie aktywności SOD i GPH-Px oraz statystycznie nieznamienne obniżenie stężenia witaminy A, C i E. Wnioski: Niedoczynność tarczycy obniża poziom równowagi oksydacyjno-redukcyjnej erytrocytów poprzez zmniejszenie oksydacyjnych uszkodzeń tłuszczów oraz zmniejszenie aktywności enzymów antyoksydacyjnych, a nie poprzez zmiany w stężeniu witamin antyoksydacyjnych. (Endokrynol Pol 2011; 62 (3): 220–223

Pheochromocytoma - chromaffin cell tumor

Pheochromocytoma (barwiak chromochłonny) jest rzadkim guzem, zbudowanym z komórek chromochłonnych, wytwarzającym aminy katecholowe. Występowanie tego guza dość często uważa się za jedną z przyczyn wtórnego nadciśnienia tętniczego, zaburzeń rytmu serca, zlewnych potów, a także, choć nieco rzadziej, zaburzeń psychicznych. Niniejsza praca stanowi próbę podsumowania aktualnej wiedzy na temat diagnostyki tego typu guza. Pheochromocytoma może być również składową zespołów endokrynologicznych, na przykład w zespole mnogiej gruczolakowatości wewnątrzwydzielniczej typu 2 (MEN 2, multiple endocrine neoplasia type 2). Badania genetyczne potwierdzają skłonność do rodzinnego występowania tego guza.Pheochromocytoma is a rare tumor derived from chromaffin cells, which produces catecholamins. The presence of this tumor is considered a cause of secondary hypertension, arrhythmias, sweating and also, but very rarely, mental disorders. Update diagnostic methods of pheochromocytoma are summarized in this article. Pheochromocytoma also coexists with endocrinological syndroms, e.g. multiple endocrine neoplasia type 2 (MEN 2). Studies confirm genetic background of pheochromocytoma occurrence

Text and Transmission

The modern reader may encounter the Greek text of Euripides' surviving plays in many forms: in print either in complete editions or in separate editions of single plays published with translations or commentaries or both, and in digital form at well-known sites on the internet. When Euripides composed his plays, he is most likely to have written on a papyrus roll, although for rough drafts of small sections he could have used wax tablets, loose papyrus sheets, or pottery sherds. Although the papyrus rolls and early codices give us intriguing glimpses of the text of the Euripides plays up the seventh century CE, the surviving complete plays depend on the medieval textual tradition. For Euripides as for Aeschylus and Sophocles, Alexandrian scholars collected texts of as many plays as they could, comparing their titles to those known from the didascalic records. About seventy plays of Euripides never reached the medieval manuscript tradition

Pulsational frequencies of the eclipsing delta-Scuti star HD 172189

The eclipsing delta-Scuti star HD 172189 is a probable member of the open cluster IC 4756 and a promising candidate target for the CoRoT mission. The detection of pulsation modes is the first step in the asteroseismological study of the star. Further, the calculation of the orbital parameters of the binary system allows us to make a dynamical determination of the mass of the star, which works as an important constraint to test and calibrate the asteroseismological models. From a detailed frequency analysis of 210 hours of photometric data of HD 172189 obtained from the STEPHI XIII campaign we have identified six pulsation frequencies with a confidence level of 99% and a seventh with a 65% confidence level in the range between 100-300 uHz. In addiction, three eclipses were observed during the campaign, allowing us to improve the determination of the orbital period of the system.Comment: 6 pages, 7 figure

Photochemistry of Furyl- and Thienyldiazomethanes: Spectroscopic Characterization of Triplet 3-Thienylcarbene

Photolysis (λ \u3e 543 nm) of 3-thienyldiazomethane (1), matrix isolated in Ar or N2 at 10 K, yields triplet 3-thienylcarbene (13) and α-thial-methylenecyclopropene (9). Carbene 13 was characterized by IR, UV/vis, and EPR spectroscopy. The conformational isomers of 3-thienylcarbene (s-E and s-Z) exhibit an unusually large difference in zero-field splitting parameters in the triplet EPR spectrum (|D/hc| = 0.508 cm–1, |E/hc| = 0.0554 cm–1; |D/hc| = 0.579 cm–1, |E/hc| = 0.0315 cm–1). Natural Bond Orbital (NBO) calculations reveal substantially differing spin densities in the 3-thienyl ring at the positions adjacent to the carbene center, which is one factor contributing to the large difference in D values. NBO calculations also reveal a stabilizing interaction between the sp orbital of the carbene carbon in the s-Z rotamer of 13 and the antibonding σ orbital between sulfur and the neighboring carbon—an interaction that is not observed in the s-E rotamer of 13. In contrast to the EPR spectra, the electronic absorption spectra of the rotamers of triplet 3-thienylcarbene (13) are indistinguishable under our experimental conditions. The carbene exhibits a weak electronic absorption in the visible spectrum (λmax = 467 nm) that is characteristic of triplet arylcarbenes. Although studies of 2-thienyldiazomethane (2), 3-furyldiazomethane (3), or 2-furyldiazomethane (4) provided further insight into the photochemical interconversions among C5H4S or C5H4O isomers, these studies did not lead to the spectroscopic detection of the corresponding triplet carbenes (2-thienylcarbene (11), 3-furylcarbene (23), or 2-furylcarbene (22), respectively)

X-ray Source Populations in the Region of the Open Clusters NGC 6633 and IC 4756

Using deep exposures (~10^5 s) with the ROSAT HRI, we have performed flux-limited surveys for X-ray sources in the vicinity of the Hyades-age open stellar clusters NGC 6633 and IC 4756, detecting 31 and 13 sources respectively. Our primary aim is to search for so-far unrecognised cluster members. We propose identifications or classifications (cluster member, field star, extragalactic field object) for the X-ray sources, based on published membership lists, and on X-ray:optical flux ratios and optical colour--magnitude diagrams. Results of simulating the expected X-ray-emitting source populations are compared with the ROSAT measurements and with the expected capabilities of the XMM mission. The simulations provide a novel method of comparing the activity levels of NGC 6633 and IC 4756 with that of the Hyades. The measurements and simulations confirm that cluster members are the major class of X-ray emitter in these fields at flux levels f_x > 10^{-14}/erg/cm^2/s (0.1--2.4 keV), contributing ~40 per cent of the total X-ray sources. We find 6 possible new members in NGC 6633, and 4 candidates in IC 4756; all require further observation to establish membership probability.Comment: 12 pages, 4 figure