203 research outputs found
Supporting Physics Teachers to Deliver the New High School Certificate Syllabus: What are the Priorities?
For the first time since 2000, the New South Wales High School Certificate (HSC) school-leavers\u27 Physics syllabus has been updated. Topics not taught in schools since 2000 have been reintroduced, the number of mandated equations has more than doubled, and students must now do 15 hours of individual or group investigations in both Years 11 and 12. The Vniversity of Wollongong (UOW) intends to support teachers in our local area by providing outreach and professional learning activities for teachers and students. To determine teachers\u27 priorities, we invited teachers to complete a short online survey. Respondents stated that they were very likely to access activities and resources, and that their top priorities were accredited professional learning workshops and support with depth studies
Recess in the 21st Century Post-COVID World
The abrupt onset of the COVID-19 pandemic forced the world into frenzied action, creating a series of ongoing stressors: school/work closings, remote learning, canceled events, family strife, fear, and a significant loss of social interactions. It is now unsurprising to learn that children's mental health has suffered. As social connection is tightly entwined with children's mental health, supporting school-based spaces for quality social interactions is an important post-pandemic recovery strategy. The unstructured school recess space is ideal for supporting recovery. A large and growing body of evidence supports the important role of recess, yet evidence also suggests that recess is not always implemented in ways that fulfill its promise
Protostars in the Elephant Trunk Nebula
The optically-dark globule IC 1396A is revealed using Spitzer images at 3.6,
4.5, 5.8, 8, and 24 microns to be infrared-bright and to contain a set of
previously unknown protostars. The mid-infrared colors of the 24 microns
detected sources indicate several very young (Class I or 0) protostars and a
dozen Class II stars. Three of the new sources (IC 1396A: gamma, delta, and
epsilon) emit over 90% of their bolometric luminosities at wavelengths greater
than 3 microns, and they are located within ~0.02 pc of the ionization front at
the edge of the globule. Many of the sources have spectra that are still rising
at 24 microns. The two previously-known young stars LkHa 349 a and c are both
detected, with component c harboring a massive disk and component a being bare.
Of order 5% of the mass of material in the globule is presently in the form of
protostars in the 10^5 to 10^6 yr age range. This high star formation rate was
likely triggered by radiation from a nearby O star.Comment: Spitzer first ApJS special issue (in press
Synthesis, Characterisation, and Preliminary In Vitro Studies of Vanadium(IV) Complexes with a Schiff Base and Thiosemicarbazones as Mixed Ligands
[VO(salâLâtryp)(H2O)] (1, salâLâtryp = NâsalicylideneâLâtryptophanate) was used as a precursor to produce the new complexes [VO(salâLâtryp)(MeATSC)]¡1.5C2H5OH [2, MeATSC = 9âAnthraldehydeâN(4)âmethylthiosemicarbazone], [VO(salâLâtryp)(Nâethhymethohcarbthio)]¡H2O [3, Nâethhymethohcarbthio = (E)âNâethylâ2â(4âhydroxyâ3âmethoxybenzylidene)hydrazinecarbothioamide] and [VO(salâLâtryp)(acetylethTSC)]¡C2H5OH {4, acetylethTSC = (E)âNâethylâ2â[1â(thiazolâ2âyl)ethylidene]hydrazinecarbothioamide} by reaction with the respective thiosemicarbazone. The chemical and structural properties of these ligands and complexes were characterised by elemental analysis, ESIâMS, FTIR, UV/Vis, ESR and 1H and 13C NMR spectroscopy and Xâray crystallography. Dimethyl sulfoxide (DMSO) and [D6]DMSO solutions of 1â4 were oxidised in air to produce vanadium(V) species, which were verified by ESIâMS and 51V NMR spectroscopy. The anticancer properties of 2â4 were examined with three colon cancer cell lines, HTCâ116, Cacoâ2 and HTâ29, and noncancerous colonic myofibroblasts, CCD18âCo. Compounds 2â3 exhibited less inhibitory effects in the CCDâ18Co cells, which indicates a possible cytotoxic selectivity towards colon cancer cells. In general, compounds that exhibit antiproliferative activity to cancer cells but do not affect noncancerous cells may have a potential in chemotherapy
Synthesis, Characterisation, and Preliminary Anti-Cancer Photodynamic Therapeutic \u3ci\u3eIn Vitro\u3c/i\u3e Studies of Mixed-Metal Binuclear Ruthenium(II)-Vanadium(IV) Complexes
We report the synthesis and characterisation of mixed-metal binuclear ruthenium(II)-vanadium(IV) complexes, which were used as potential photodynamic therapeutic agents for melanoma cell growth inhibition. The novel complexes, [Ru(pbt)2(phen2DTT)](PF6)2â˘1.5H2O 1 (where phen2DTT = 1,4-bis(1,10-phenanthrolin-5-ylsulfanyl)butane-2,3-diol and pbt = 2-(2\u27-pyridyl)benzothiazole) and [Ru(pbt)2(tpphz)](PF6)2â˘3H2O 2 (where tpphz = tetrapyrido[3,2-a:2â˛,3â˛-c:3âł,2âł-h:2â´,3â´-j]phenazine) were synthesised and characterised. Compound 1 was reacted with [VO(sal-L-tryp)(H2O)] (where sal-L-tryp = N-salicylidene-L-tryptophanate) to produce [Ru(pbt)2(phen2DTT)VO(sal-L-tryp)](PF6)2â˘5H2O 4; while [VO(sal-L-tryp)(H2O)] was reacted with compound 2 to produce [Ru(pbt)2(tpphz)VO(sal-L-tryp)](PF6)2â˘6H2O 3. All complexes were characterised by elemental analysis, HRMS, ESI MS, UV-visible absorption, ESR spectroscopy, and cyclic voltammetry, where appropriate. In vitro cell toxicity studies (with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay) via dark and light reaction conditions were carried out with sodium diaqua-4,4\u27,4â,4â\u27tetrasulfophthalocyaninecobaltate(II) (Na4[Co(tspc)(H2O)2]), [VO(sal-L-tryp)(phen)]â˘H2O, and the chloride salts of complexes 3 and 4. Such studies involved A431, human epidermoid carcinoma cells; human amelanotic malignant melanoma cells; and HFF, non-cancerous human skin fibroblast cells. Both chloride salts of complexes 3 and 4 were found to be more toxic to melanoma cells than to non-cancerous fibroblast cells, and preferentially led to apoptosis of the melanoma cells over non-cancerous skin cells. The anti-cancer property of the chloride salts of complexes 3 and 4 was further enhanced when treated cells were exposed to light, while no such effect was observed on non-cancerous skin fibroblast cells. ESR and 51V NMR spectroscopic studies were also used to assess the stability of the chloride salts of complexes 3 and 4 in aqueous media at pH 7.19. This research illustrates the potential for using mixed-metal binuclear ruthenium(II)-vanadium(IV) complexes fighting skin cancer
WISE J233237.05â505643.5: A Double-peaked, Broad-lined Active Galactic Nucleus with a Spiral-shaped Radio Morphology
We present radio continuum mapping, optical imaging, and spectroscopy of the newly discovered double-peaked, broad-lined active galactic nucleus (AGN) WISE J233237.05â505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid morphology, characterized by a bright core, jet, and Doppler-boosted lobe structures in Australian Telescope Compact Array continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332â5056 is hosted by a disk-like galaxy. The core has a projected 5'' linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch, optical-near-IR photometric measurements indicate significant variability over a 3-20 yr baseline from the AGN component. Gemini South optical data show unusual double-peaked emission-line features: the centroids of the broad-lined components of HÎą and Hβ are blueshifted with respect to the narrow lines and host galaxy by ~3800 km s^(â1). We examine possible cases that involve single or double supermassive black holes in the system and discuss the required future investigations to disentangle the mysterious nature of this system
Synthesis, characterization, DNA binding, topoisomerase inhibition, and apoptosis induction studies of a novel cobalt(III) complex with a thiosemicarbazone ligand
In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)(OCO)]Cl¡6HO 2 (where phenâŻ=âŻ1,10-phenanthroline) were synthesized. [Co(phen)(OCO)]Cl¡6HO 2 was used to produce anhydrous [Co(phen)(HO)](NO)3. Subsequently, anhydrous [Co(phen)(HO)](NO)3 was reacted with MeATSC 1 to produce [Co(phen)(MeATSC)](NO)¡1.5HO¡CHOH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV-visible, and multinuclear NMR (H, C, and Co) spectroscopy, along with HRMS, and conductivity measurements, where appropriate. Interactions of MeATSC 1 and complex 4 with calf thymus DNA (ctDNA) were investigated by carrying out UV-visible spectrophotometric studies. UV-visible spectrophotometric studies revealed weak interactions between ctDNA and the analytes, MeATSC 1 and complex 4 (KâŻ=âŻ8.1âŻĂâŻ10 and 1.6âŻĂâŻ10âŻM, respectively). Topoisomerase inhibition assays and cleavage studies proved that complex 4 was an efficient catalytic inhibitor of human topoisomerases I and IIÎą. Based upon the results obtained from the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on 4T1-luc metastatic mammary breast cancer cells (ICâŻ=âŻ34.4âŻÂąâŻ5.2âŻÎźM when compared to ICâŻ=âŻ13.75âŻÂąâŻ1.08âŻÎźM for the control, cisplatin), further investigations into the molecular events initiated by exposure to complex 4 were investigated. Studies have shown that complex 4 activated both the apoptotic and autophagic signaling pathways in addition to causing dissipation of the mitochondrial membrane potential (ÎΨ). Furthermore, activation of cysteine-aspartic proteases3 (caspase 3) in a time- and concentration-dependent manner coupled with the ÎΨ, studies implicated the intrinsic apoptotic pathway as the major regulator of cell death mechanism
The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
The all sky surveys done by the Palomar Observatory Schmidt, the European
Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed
Astronomical Satellite and the 2 Micron All Sky Survey have proven to be
extremely useful tools for astronomy with value that lasts for decades. The
Wide-field Infrared Survey Explorer is mapping the whole sky following its
launch on 14 December 2009. WISE began surveying the sky on 14 Jan 2010 and
completed its first full coverage of the sky on July 17. The survey will
continue to cover the sky a second time until the cryogen is exhausted
(anticipated in November 2010). WISE is achieving 5 sigma point source
sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the
ecliptic in bands centered at wavelengths of 3.4, 4.6, 12 and 22 microns.
Sensitivity improves toward the ecliptic poles due to denser coverage and lower
zodiacal background. The angular resolution is 6.1, 6.4, 6.5 and 12.0
arc-seconds at 3.4, 4.6, 12 and 22 microns, and the astrometric precision for
high SNR sources is better than 0.15 arc-seconds.Comment: 22 pages with 19 included figures. Updated to better match the
accepted version in the A
Shocked Molecular Gas in the Supernova Remnants W 28 and W 44: Near-infrared and millimeter-wave observations
High resolution millimeter-wave and near-infrared observations of the
supernova remnants W28 and W44 reveal extensive shocked molecular gas where
supernova blast waves are propagating into giant molecular clouds. New CO
observations were carried out with the IRAM 30-m and ARO 12-m telescopes, and
the near-infrared observations were with Palomar 200-inch telescope. The
near-infrared observations reveal shocked H2 emission from both supernova
remnants, showing intricate networks of filaments on arcsec scales, following
the bright ridges of the radio shells. The CO and CS linewidths, indicative of
the shock speed, are 20-30 km/s. Both the near-infrared and millimeter-wave
emission are attributed to shocks into gas with density >1e3 cm-3. Individual
shock structures are resolved in the H2 emission, with inferred edge-on shock
thickness ~1e17 cm, consistent with non-dissociative shocks into gas densities
of 1e3-1e4 cm-3. Bright 1720 MHz OH masers are located within the shocked H2
gas complexes and highlight only localized areas where the conditions for
masing are optimal. The Halpha and X-ray emission, have morphologies very
different from the radio. We find a detailed correlation of the radio and H2
emission for some long filaments, indicating cosmic ray acceleration or
re-acceleration due to the shocks into moderately dense gas. The different
morphologies of these two remnants at different wavelengths is explained by a
highly nonuniform structure for giant molecular clouds.Comment: ApJ, in press; several figures in jpg for
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