On the properties of the interstellar medium in extremely metal-poor blue compact dwarf galaxies: GMOS-IFU spectroscopy and SDSS photometry of the double-knot galaxy HS 2236+1344

The main goal of this study is to carry out a spatially resolved investigation of the warm interstellar medium (ISM) in the extremely metal-poor Blue Compact Dwarf (BCD) galaxy HS 2236+1344. Special emphasis is laid on the analysis of the spatial distribution of chemical abundances, emission-line ratios and kinematics of the ISM, and to the recent star-forming activity in this galaxy. This study is based on optical integral field unit spectroscopy data from Gemini Multi-Object Spectrograph at the Gemini North telescope and archival Sloan Digital Sky Survey images. The data were obtained in two different positions across the galaxy, obtaining a total 4 arcsec X 8 arcsec field which encompasses most of its ISM. Emission-line maps and broad-band images obtained in this study indicate that HS 2236+1344 hosts three Giant HII regions. Our data also reveal some faint curved features in the BCD periphery that might be due to tidal perturbations or expanding ionized-gas shells. The ISM velocity field shows systematic gradients along the major axis of the BCD, with its south-eastern and north-western half differing by ~80 km/s in their recessional velocity. The Ha and Hb equivalent width distribution in the central part of HS 2236+1344 is consistent with a very young (~3 Myr) burst. Our surface photometry analysis indicates that the ongoing starburst provides ~50% of the total optical emission, similar to other BCDs. It also reveals an underlying lower-surface brightness component with moderately red colors, which suggest that the galaxy has undergone previous star formation. We derive an integrated oxygen abundance of 12+log(O/H)=7.53\pm0.06 and a nitrogen-to-oxygen ratio of log(N/O)=-1.57\pm0.19. Our results are consistent, within the uncertainties, with a homogeneous distribution of oxygen and nitrogen within the ISM of the galaxy. (abridged)Comment: 15 pages, 16 figures, accepted for publication in A&

Ti3SiC2-Cf composites by spark plasma sintering: Processing, microstructure and thermo-mechanical properties

MAX phases, and particularly Ti3SiC2, are interesting for high temperature applications. The addition of carbon fibers can be used to reduce the density and to modify the properties of the matrix. This work presents the densification and characterization of Ti3SiC2 based composites with short carbon fibers using a fast and simple fabrication approach: dry mixing and densification by Spark Plasma Sintering. Good densification level was obtained below 1400 °C even with a high amount of fibers. The reaction of the fibers with the matrix is limited thanks to the fast processing time and depends on the amount of fibers in the composite. Bending strength at room temperature, between 437 and 120 MPa, is in the range of conventional CMCs with short fibers and according to the resistance of the matrix and the presence of residual porosity. Thermo-mechanical properties of the composites up to 1500 °C are also presented.This work has received funding from the European Union’s Horizon2020 “Research and innovation programme” under grant agreement No 685594 (C3HARME

Survivorship of soybean aphid biotypes (Hemiptera: Aphididae) on winter hosts, common and glossy buckthorn

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean, Glycine max (L.) Merr., both in Asia where it is native, and in the USA where it is adventive. The rapid spread and establishment of the soybean aphid in the USA since its discovery in 2000 was successful because of extensive soybean production in the Midwest and the wide distribution of common buckthorn, Rhamnus cathartica (L.), its preferred primary winter host. The survivorship of four soybean aphid biotypes on com­mon and glossy buckthorn, Frangula alnus Mill., were compared. Our study showed that nymph oviparae of soybean aphid biotypes 1, 2, 3 and 4 reached adulthood and produced eggs on glossy buckthorn. When com­paring morphs between the hosts, greater numbers were recorded on common than glossy buckthorn, with one exception where the number of eggs per bud for soybean aphid biotype 2 was not different between the hosts. We found for the first-time soybean aphid biotypes 2 and 3 apterous males produced on common and glossy buckthorn. Morphological descriptions of live and mounted alate and apterous males are presented

New records of invasive aphids (Hemiptera: Aphididae) on garlic mustard in the USA

Lipaphis alliariae Müller (Hemiptera: Aphididae) was identified from specimens collected in Lake County, Ohio, on the invasive garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae). The identification was performed on apterous viviparae using morphological and molecular data. Body color and shape of the cauda discriminated L. alliariae and L. pseudobrassicae Davis. Measurements of morphological characters of both species were similar, but they have distinct characters distinguishing them from L. erysimi Kaltenbach. Neighbor-joining analysis of cytochrome oxidase 1 (Cox1) barcoding indicated a close relation­ship of the aphids that feed on Brassicaceae, and the range of pair-wise distances for Cox1 barcoding of these species was 0.3–0.9%. Garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae) is a highly invasive weed species in the United States. It was brought from Europe in the 1800s for herbal uses and erosion control (Munger 2001; USDA 2022). Records of aphids that feed on garlic mustard include Aphis gossypii Glover, Brevicoryne brassicae Linnaeus, Lipaphis alliariae Müller, L. erysimi Kaltenbach, Myzus ascalonicus Doncaster, M. ornatus Laing, M. persicae (Sulzer), and Rhopalosiphoninus latysiphon Davidson (Blackman and Eastop 2022). Out of this list L. alliariae and L. erysimi were not included in the list of aphid species adventive to North America north of Mexico (Foottit et al. 2006; Skvarla et al. 2017). Our article presents new records of aphids on garlic mustard in the USA

New records of invasive aphids (Hemiptera: Aphididae) on garlic mustard in the USA

Lipaphis alliariae Müller (Hemiptera: Aphididae) was identified from specimens collected in Lake County, Ohio, on the invasive garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae). The identification was performed on apterous viviparae using morphological and molecular data. Body color and shape of the cauda discriminated L. alliariae and L. pseudobrassicae Davis. Measurements of morphological characters of both species were similar, but they have distinct characters distinguishing them from L. erysimi Kaltenbach. Neighbor-joining analysis of cytochrome oxidase 1 (Cox1) barcoding indicated a close relation­ship of the aphids that feed on Brassicaceae, and the range of pair-wise distances for Cox1 barcoding of these species was 0.3–0.9%. Garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae) is a highly invasive weed species in the United States. It was brought from Europe in the 1800s for herbal uses and erosion control (Munger 2001; USDA 2022). Records of aphids that feed on garlic mustard include Aphis gossypii Glover, Brevicoryne brassicae Linnaeus, Lipaphis alliariae Müller, L. erysimi Kaltenbach, Myzus ascalonicus Doncaster, M. ornatus Laing, M. persicae (Sulzer), and Rhopalosiphoninus latysiphon Davidson (Blackman and Eastop 2022). Out of this list L. alliariae and L. erysimi were not included in the list of aphid species adventive to North America north of Mexico (Foottit et al. 2006; Skvarla et al. 2017). Our article presents new records of aphids on garlic mustard in the USA

New Records of aphids (Hemiptera: Aphididae) on Industrial Hemp in the US Midwest

Industrial hemp (Cannabis sativa L.) production in the USA is increasing, and with it the list of insects colonizing the crop. In this article, we report new records of Aphis craccivora Koch 1854, Aphis fabae Scopoli, Aphis gossypiiGlover 1763, Aphis spiraecola Patch 1914 and Myzus persicae (Sulzer 1776) on industrial hemp in East Lansing, Michigan in fall 2020. In addition, between 2017 and 2020, the number of suction trap sites detecting P. cannabisincreased, and as well as the number of sites with multiple weeks of detections. The timing of detection changed, from only late season (fall migrants) in 2017, to catches spanning spring, summer, and fall in 2019 and 2020. These changes likely reflect the increase in industrial hemp production in the landscape in the Midwestern US

FGC 1287 and its enigmatic 250 kpc long HI tail in the outskirts of Abell 1367

We present H i and radio continuum, narrow-band H alpha imaging, IFU spectroscopy, and X-ray observations of the FGC 1287 triplet projected similar to 1.8 Mpc west of the galaxy cluster Abell 1367. One triplet member, FGC 1287, displays an exceptionally long, 250 kpc H i tail and an unperturbed stellar disc which are the typical signatures of ram pressure stripping (RPS). To generate detectable RPS signatures the presence of an Intracluster medium ICM or intragroup medium IGM with sufficient density to produce RPS at a realistic velocity relative to the ICM or IGM is a prerequisite. However, XMM-Newton observations were not able to detect X-ray emission from the triplet, implying that if a hot ICM/IGM is present, its density, n(e), is less than 2.6 x 10(-5) cm(-3). Higher resolution VLA H i data presented here show FGC 1287's H i disc is truncated and significantly warped, whereas the H i tail is clumpy. TNG H alpha imaging identified three star-forming clumps projected within 20 kpc of FGC 1287's disc, with VIMOS-IFU data confirming two of these are counterparts to H i clumps in the tail. The triplet's H i kinematics, together with H alpha and radio continuum imaging suggests an interaction may have enhanced star formation in FGC 1287's disc, but cannot readily account for the origin of the long H i tail. We consider several scenarios which might reconcile RPS with the non-detection of ICM or IGM X-ray emission but none of these unambiguously explains the origin of the long H i tail.Peer reviewe

Susceptibility to unconscious influences is unaffected by a challenging inhibitory task or mental exhaustion

Unconscious influences have been demonstrated in a variety of behavioural contexts, however, a key question remains – to what extent do such influences vary with our changing mental states? We examine whether a prior inhibitory challenge increases susceptibility to subliminal priming in a stem completion task employing neutral (Experiment 1) and reward salient terms (Experiment 2). Results show stem completions to be significantly influenced by unconscious priming, and the challenging inhibitory task (the Stroop) to be significantly more mentally exhausting than the control task. However, neither the degree of inhibitory challenge, trait self-control, nor task-related mental exhaustion significantly influenced unconscious priming. Bayesian analysis provides strong evidence that prior inhibitory challenge does not affect susceptibility to unconscious priming. The study supports the conclusion that unconscious processing can be independent of consciously experienced mental states and provides reassurance that inhibitory impairment, common to mood disorders, should not increase susceptibility to unconscious influences