Discovery of Dust Emission Activity Emanating from Main-belt Asteroid 2015 FW412

We present the discovery of activity emanating from main-belt asteroid 2015 FW412, a finding stemming from the Citizen Science project Active Asteroids, a NASA Partner program. We identified a pronounced tail originating from 2015 FW412 and oriented in the anti-motion direction in archival Blanco 4-m (Cerro Tololo Inter-American Observatory, Chile) Dark Energy Camera (DECam) images from UT 2015 April 13, 18, 19, 21 and 22. Activity occurred near perihelion, consistent with the main-belt comets (MBCs), an active asteroid subset known for sublimation-driven activity in the main asteroid belt; thus 2015 FW412 is a candidate MBC. We did not detect activity on UT 2021 December 12 using the Inamori-Magellan Areal Camera and Spectrograph (IMACS) on the 6.5 m Baade telescope, when 2015 FW412 was near aphelion.Comment: 4 pages, 1 figur

Frontal alpha asymmetry: A potential biomarker of approach-withdrawal motivation towards pain

Pain-related catastrophising is a maladaptive coping strategy known to have a strong influence on clinical pain outcomes and treatment efficacy. Notwithstanding, little is known about its neurophysiological correlates. There is evidence to suggest catastrophising is associated with resting-state EEG frontal alpha asymmetry (FAA) patterns reflective of greater relative right frontal activity, which is known to be linked to withdrawal motivation and avoidance of aversive stimuli. The present study aims to investigate whether such a relationship occurs in the situational context of experimental pain. A placebo intervention was also included to evaluate effects of a potential pain-relieving intervention on FAA. 35 participants, including both chronic pain patients and healthy subjects, completed the Pain Catastrophising Scale (PCS) questionnaire followed by EEG recordings during cold pressor test (CPT)-induced tonic pain with or without prior application of placebo cream. There was a negative correlation between FAA and PCS-subscale helplessness scores, but not rumination or magnification, during the pre-placebo CPT condition. Moreover, FAA scores were shown to increase significantly in response to pain, indicative of greater relative left frontal activity that relates to approach-oriented behaviours. Placebo treatment elicited a decrease in FAA in low helplessness scorers, but no significant effects in individuals scoring above the mean on PCS-helplessness. These findings suggest that, during painful events, FAA may reflect the motivational drive to obtain reward of pain relief, which may be diminished in individuals who are prone to feel helpless about their pain. This study provides valuable insights into biomarkers of pain-related catastrophising and prospects of identifying promising targets of brain-based therapies for chronic pain management

Generation of transgenic Mycosphaerella fijiensis expressing reporter genes: tools for pathogenicity and mating studies.

Mycosphaerella fijiensis, the causal agent of black leaf streak disease is the most devastating pathogen of banana and plantains. Detailed studies on the plant pathogen interaction as well as mating behavior could be improved by the use of non-destructive reporter gene assays. M. fijiensis isolates from different global populations and opposite mating types, CIRAD86 (Mat1-1) from Cameroon and CIRAD139A (Mat1-2) from Colombia, were selected for our studies. In order to generate transgenic M. fijiensis strains, two gene constructs carrying either reporter genes gfp (green fluorescent protein) or dsred (Discosoma sp. red fluorescent protein) driven by the constitutive promoter PtoxA were used. Both constructs also carried the hph gene for resistance to the antibiotic hygromycin as selective marker. Transformation procedures mediated by Agrobacterium tumefaciens strain LBA1100 were carried out using macerated mycelium from 3-week-old cultures of CIRAD86 and CIRAD139A. After the cocultivation period, the cultures were transferred to selective medium containing 30 mg/l hygromycin. Transgenic events were identified by fluorescent microscopy observations after 2-3 weeks. In this part of the work, we were able to generate transgenic strains from both isolates expressing either reporter genes, namely CIRAD86::GFP, CIRAD86::DsRed, CIRAD139A::GFP and CIRAD139A::DsRed. Simultaneously, pathogenicity validation screens and mating assays using in vitro leaf fragments are also being conducted in order to characterize the different stages in the pathogenesis on banana

The Young Outer Disk of M83

Deep near-infrared images recorded with NICI on Gemini South are used to investigate the evolved stellar content in the outer regions of the south east quadrant of the spiral galaxy M83. A diffuse population of asymptotic giant branch (AGB) stars is detected outside of the previously identified young and intermediate age star clusters in the outer disk. The brightest AGB stars have M_K > -8, and the AGB luminosity function (LF) is well-matched by model LFs that assume ages < 1 Gyr. The specific star formation rate (SFR) during the past few Gyr estimated from AGB star counts is consistent with that computed from mid-infrared observations of star clusters at similar radii, and it is concluded that the disruption timescale for star clusters in the outer disk is << 1 Gyr. The luminosity function and specific frequency of AGB stars varies with radius, in a manner that is indicative of lower luminosity-weighted ages at larger radii. Modest numbers of red supergiants are also found, indicating that there has been star formation during the past 100 Myr, while the ratio of C stars to M giants is consistent with that expected for a solar metallicity system that has experienced a constant SFR for the past few Gyrs.Comment: Accepted for publication in Ap

First report on the herpetofauna of Pulau Aur, Johor, West Malaysia

With the exception ofTweedie's (1983) account ofCalamaria lovii, published accounts on the herpetofauna of Pulau Aur, located 63 km off the south-east coast of peninsular Malaysia in the South China Sea did not exist prior to this report. The only species known from the island were based on the museum records ofLimnonectes blythii, Mabuya multi/asciata, Bronchocela cristatella, Gehyra mutilata, Varanus nebulosus and Ahaetulla prasina deposited in the Raffles Museum of Biodiversity Research. A short expedition to the island on 15-16 July 2001 yielded an additional 12 species, comprising 10 lizards and two snakes: Limnonectes blythii; Bronchocela cristatella; Cnemaspis cf. Nigridia; Cosymbotus platyurus; Cyrtodactylus consobrinus; Gehyra mutilata; Gekko monarchus; Hemidactylus frenatus; Dasia o/ivacea; Emoia atrocostata; Lygosoma bowring;;; Mabuya multi/asciata; Sphenomorphus scotophi/us; Varanus nebulosus; Varanus salvator; Ramphotyphlops cf. braminus; Calamaria lovii and Macropisthodon flaviceps

DNA Methylation-Independent Reversion of Gemcitabine Resistance by Hydralazine in Cervical Cancer Cells

BACKGROUND: Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in cervical cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: The cervical cancer cell line CaLo cell line was cultured in the presence of increasing concentrations of gemcitabine. Down-regulation of hENT1 & dCK genes was observed in the resistant cells (CaLoGR) which was not associated with promoter methylation. Treatment with hydralazine reversed gemcitabine resistance and led to hENT1 and dCK gene reactivation in a DNA promoter methylation-independent manner. No changes in HDAC total activity nor in H3 and H4 acetylation at these promoters were observed. ChIP analysis showed H3K9m2 at hENT1 and dCK gene promoters which correlated with hyper-expression of G9A histone methyltransferase at RNA and protein level in the resistant cells. Hydralazine inhibited G9A methyltransferase activity in vitro and depletion of the G9A gene by iRNA restored gemcitabine sensitivity. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that acquired gemcitabine resistance is associated with DNA promoter methylation-independent hENT1 and dCK gene down-regulation and hyper-expression of G9A methyltransferase. Hydralazine reverts gemcitabine resistance in cervical cancer cells via inhibition of G9A histone methyltransferase

Stress and sexual reproduction affect the dynamics of the wheat pathogen effector AvrStb6 and strobilurin resistance

Host resistance and fungicide treatments are cornerstones of plant-disease control. Here, we show that these treatments allow sex and modulate parenthood in the fungal wheat pathogen Zymoseptoria tritici. We demonstrate that the Z. tritici–wheat interaction complies with the gene-for-gene model by identifying the effector AvrStb6, which is recognized by the wheat resistance protein Stb6. Recognition triggers host resistance, thus implying removal of avirulent strains from pathogen populations. However, Z. tritici crosses on wheat show that sex occurs even with an avirulent parent, and avirulence alleles are thereby retained in subsequent populations. Crossing fungicide-sensitive and fungicide-resistant isolates under fungicide pressure results in a rapid increase in resistance-allele frequency. Isolates under selection always act as male donors, and thus disease control modulates parenthood. Modeling these observations for agricultural and natural environments reveals extended durability of host resistance and rapid emergence of fungicide resistance. Therefore, fungal sex has major implications for disease control