Warm HCN, C2H2, and CO in the disk of GV Tau

We present the first high-resolution, ground-based observations of HCN and C2H2 toward the T Tauri binary star system GV Tau. We detected strong absorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+) absorption toward the primary (GV Tau S) but not the infrared companion. We also report CO column densities and rotational temperatures, and present abundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit for CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward the infrared companion and results suggest that abundances may differ between the two sources.Comment: 23 pages, 6 figures, accepted by Ap

Uniaxial magnetocrystalline anisotropy in CaRuO3{\rm CaRuO_3}

${\rm CaRuO_3}$ is a paramagnetic metal and since its low temperature resistivity is described by $\rho=\rho_0+AT^\gamma$ with $\gamma \sim 1.5$, it is also considered a non-Fermi liquid (NFL) metal. We have performed extensive magnetoresistance and Hall effect measurements of untwinned epitaxial films of ${\rm CaRuO_3}$. These measurements reveal that ${\rm CaRuO_3}$ exhibits uniaxial magnetocrystalline anisotropy. In addition, the low-temperature NFL behavior is most effectively suppressed when a magnetic field is applied along the easy axis, suggesting that critical spin fluctuations, possibly due to proximity of a quantum critical phase transition, are related to the NFL behavior.Comment: 7 figure

A comparison of entering vs. exiting visual acuities of a humanitarian eye glass mission to Mexico

Background: The purpose of this study was to determine the amount of improvement in visual acuity (VA) of persons helped through humanitarian optometry. Methods: A humanitarian clinic was established for 3 days in San Bias, Nayarit, Mexico. During the 3 days, 890 people were evaluated for refractive error, binocularity, and ocular health. Visual acuity was taken at the beginning of the evaluation and at the end when spectacle correction was dispensed. Results: Significant improvement was seen in visual acuities at both distance and nearing the vast majority of patients seen. Data showed that of 731 people who received glasses for near (either as single vision or bifocal), the average exiting VA was between 20/20 and 20/3 0. The data also showed that of 413 people that received glasses for distance (single vision or bifocal), the average exiting VA was 20/32. An improvement in near acuity for cataract patients was evident, while improvement in distance acuity for these patients was minimal. Conclusion: The people of third world countries are at a significant disadvantage in the realm of eye care. By simply providing spectacle corrections, a large portion of the population seen was able to improve their acuity status and be removed from the categories of visually impaired or legally blind

A survey of SiO 5-4 emission towards outflows from massive young stellar objects

Results are presented of a survey of SiO 5-4 emission observed with the James Clerk Maxwell Telescope (JCMT) towards a sample of outflows from massive young stellar objects. The sample is drawn from a single-distance study by Ridge & Moore. In a sample of 12 sources, the 5-4 line was detected in 5, a detection rate of 42 per cent. This detection rate is higher than that found for a sample of low-luminosity outflow sources, although for sources of comparable luminosity, it is in good agreement with the results of a previous survey of high luminosity sources. For most of the detected sources, the 5-4 emission is compact or slightly extended along the direction of the outflow. NGC6334I shows a clear bipolar flow in the 5-4 line. Additional data were obtained for W3-IRS5, AFGL5142 and W75N for the 2-1 transition of SiO using the Berkeley-Illinois-Maryland Association (BIMA) millimetre interferometer. There is broad agreement between the appearance of the SiO emission in both lines, though there are some minor differences. The 2-1 emission in AFGL5142 is resolved into two outflow lobes which are spatially coincident on the sky, in good agreement with previous observations. In general the SiO emission is clearly associated with the outflow. The primary indicator of SiO 5-4 detectability is the outflow velocity, i.e. the presence of SiO is an indicator of a high velocity outflow. This result is consistent with the existence of a critical shock velocity required to disrupt dust grains and subsequent SiO formation in post-shock gas. There is also weak evidence that higher luminosity sources and denser outflows are more likely to be detected.Comment: Accepted for publication in MNRA

Dense cores in the L1630 molecular cloud: discovering new protostars with SCUBA

Maps of the 450 micron and 850 micron dust continuum emission from three star-forming condensations within the Lynds 1630 molecular cloud, made with the SCUBA bolometer array, reveal the presence of four new submillimetre sources, each of a few solar masses, two of which are probably Class I, two Class 0, as well as several sources whose existence was previously known. The sources are located in filaments and appear elongated when observed at 450 microns. They likely have dust temperatures in the range 10 to 20 K, in good agreement with previous ammonia temperature estimates. Attempts to fit their structures with power-law and Gaussian density distributions suggest that the central distribution is flatter than expected for a simple singular isothermal sphere. Although the statistics are poor, our results suggest that the ratio of `protostellar core' mass to total virial mass may be similar for both large and small condensations.Comment: 10 pages, 9 figures, uses mn.st

A convenient one-pot synthesis, and characterisation of the ω-bromo-1-(4-cyanobiphenyl-4’-yl) alkanes (CBnBr)

Open access via T&F agreementPeer reviewedPublisher PD

Striatal Synapse Degeneration and Dysfunction Are Reversed by Reactivation of Wnt Signaling

Synapse degeneration in the striatum has been associated with the early stages of Parkinson’s and Huntington’s diseases (PD and HD). However, the molecular mechanisms that trigger synaptic dysfunction and loss are not fully understood. Increasing evidence suggests that deficiency in Wnt signaling triggers synapse degeneration in the adult brain and that this pathway is affected in neurodegenerative diseases. Here, we demonstrate that endogenous Wnt signaling is essential for the integrity of a subset of inhibitory synapses on striatal medium spiny neurons (MSNs). We found that inducible expression of the specific Wnt antagonist Dickkopf-1 (Dkk1) in the adult striatum leads to the loss of inhibitory synapses on MSNs and affects the synaptic transmission of D2-MSNs. We also discovered that re-activation of the Wnt pathway by turning off Dkk1 expression after substantial loss of synapses resulted in the complete recovery of GABAergic and dopamine synapse number. Our results also show that re-activation of the Wnt pathway leads to a recovery of amphetamine response and motor function. Our studies identify the Wnt signaling pathway as a potential therapeutic target for restoring neuronal circuits after synapse degeneration

Bunk attendance of feedlot cattle monitored with radio frequency technology

Bunk attendance of 72 feedlot cattle (412 ± 23.6 kg) was monitored for 86 d using radio frequency technology. Late morning and late afternoon were confirmed as primary ad libitum feeding periods. The system detected differences (P \u3c 0.005) in feeding behaviour in response to level of feeding and frequency of meals

Can even-membered liquid crystal dimers exhibit the twist-bend nematic phase? The preparation and properties of disulphide and thioether linked dimers

Publisher Copyright: © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Peer reviewedPublisher PD