White dwarf dynamical interactions and fast optical transients

This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Recent advances in time-domain astronomy have uncovered a new class of optical transients with timescales shorter than typical supernovae and a wide range of peak luminosities. Several subtypes have been identi ed within this broad class, including Ca-rich transients, .Ia supernovae, and fast/bright transients. We examine the predic- tions from a state-of-the-art grid of three-dimensional simulations of dynamical white dwarf interactions in the context of these fast optical transients. We nd that for colli- sions involving carbon-oxygen or oxygen-neon white dwarfs the peak luminosities and durations of the light curves in our models are in good agreement with the properties of fast/bright transients. When one of the colliding white dwarfs is made of helium the properties of the light curves are similar to those of Ca-rich gap transients. The model lightcurves from our white dwarf collisions are too slow to reproduce those of .Ia SNe, and too fast to match any normal or peculiar Type Ia supernova.This work was partially funded by the MINECO grant AYA2014-59084-P and by the AGAUR (EG-B). CB acknowledges support from grants NASA ADAP NNX15AM03G S01 and NSF/AST-1412980. We acknowl- edge the useful comments of our referee, which helped in improving the original version of the paper

Compounds from multilayer plastic bags cause reproductive failures in artificial insemination

High levels of reproductive failure were detected in some Spanish sow farms in the Spring of 2010. Regular returns to estrus and variable reductions in litter size were observed. The problem started suddenly and did not appear to be related to the quality of the ejaculates, disease, alterations of body condition or any other apparent reasons. Subsequent studies determined that the problem was the origin of the plastic bags used for semen storage. Chemical analysis of the suspicious bags identified unexpected compounds such as BADGE, a cyclic lactone and an unknown phthalate that leached into the semen at concentrations of 0.2 to 2.5 mg/L. Spermatozoa preserved in these bags passed all of the routine quality control tests, and no differences were observed between storage in the control and suspicious bags (p . 0.05). In vitro fecundation tests and endocrine profiler panel analysis (EPP) did not show any alterations, whereas the in vivo tests confirmed the described failure. This is the first described relationship between reproductive failure and toxic compounds released from plastic bags

Tryptophan depletion affects compulsive behaviour in rats:strain dependent effects and associated neuromechanisms

RATIONALE: Compulsive behaviour, present in different psychiatric disorders, such as obsessive-compulsive disorder, schizophrenia and drug abuse, is associated with altered levels of monoamines, particularly serotonin (5-hydroxytryptamine) and its receptor system. OBJECTIVES: The present study investigated whether 5-HT manipulation, through a tryptophan (TRP) depletion by diet in Wistar and Lister Hooded rats, modulates compulsive drinking in schedule-induced polydipsia (SIP) and locomotor activity in the open-field test. The levels of dopamine, noradrenaline, serotonin and its metabolite were evaluated, as well as the 5-HT(2A) and 5-HT(1A) receptor binding, in different brain regions. METHODS: Wistar rats were selected as high (HD) or low (LD) drinkers according to their SIP behaviour, while Lister hooded rats did not show SIP acquisition. Both strains were fed for 14 days with either a TRP-free diet (T−) or a TRP-supplemented diet (T+) RESULTS: The TRP depletion diet effectively reduced 5-HT levels in the frontal cortex, amygdala and hippocampus in both strains of rats. The TRP-depleted HD Wistar rats were more sensitive to 5-HT manipulation, exhibiting more licks on SIP than did the non-depleted HD Wistar rats, while the LD Wistar and the Lister Hooded rats did not exhibit differences in SIP. In contrast, the TRP-depleted Lister Hooded rats increased locomotor activity compared to the non-depleted rats, while no differences were found in the Wistar rats. Serotonin 2A receptor binding in the striatum was significantly reduced in the TRP-depleted HD Wistar rats. CONCLUSIONS: These results suggest that alterations of the serotonergic system could be involved in compulsive behaviour in vulnerable populations

Collagen-laponite nanoclay hydrogels for tumor spheroid growth

The extracellular matrix (ECM) plays an important regulatory role in the development and progression of tumoral tissue. Its functions and properties are crucial in determining tumor cell behavior such as invasion, migration, and malignancy development. Our study explores the role of collagen type I in cancer development and spread using engineered tumor models like multicellular spheroids grown in collagen-based hydrogels to simulate early tumor formation. We employ microfluidic techniques to test the hypothesis that (i) adding Laponite nanoclay to collagen hydrogels modifies mechanical and rheological properties and (ii) changing the stiffness of the collagen microenvironment affects tumor spheroid growth. Our findings support our theories and suggest the use of ECM components and engineered tumor models in cancer research, offering a biocompatible and biomimetic method to tailor the mechanical properties of conventional collagen hydrogels

Eumycetoma caused by Diaporthe phaseolorum (Phomopsis phaseoli): a case report and a mini-review of Diaporthe/Phomopsis spp invasive infections in humans

AbstractDiaporthe phaseolorum (syn. Phomopsis phaseoli) is a frequent fungal parasite of plants, present on all continents around the world. It has rarely been involved in human diseases. We report a case of eumycetoma with osteomyelitis of the forefoot caused by this fungus and diagnosed by molecular biology. The patient had positive HTLV-1 serology and was a farmer from French Guiana who walked barefoot. He was successfully treated with long-term oral itraconazole (400 mg/day). A review of the literature underlines the essential roles of plants and host immunosuppression in this infection and the favourable outcome with a triazole antifungal treatment

X-ray detection with Micromegas with background levels below 10−6^{-6} keV−1^{-1}cm−2^{-2}s−1^{-1}

Micromegas detectors are an optimum technological choice for the detection of low energy x-rays. The low background techniques applied to these detectors yielded remarkable background reductions over the years, being the CAST experiment beneficiary of these developments. In this document we report on the latest upgrades towards further background reductions and better understanding of the detectors' response. The upgrades encompass the readout electronics, a new detector design and the implementation of a more efficient cosmic muon veto system. Background levels below 10$^{-6}$keV$^{-1}$cm$^{-2}$s$^{-1}$ have been obtained at sea level for the first time, demonstrating the feasibility of the expectations posed by IAXO, the next generation axion helioscope. Some results obtained with a set of measurements conducted in the x-ray beam of the CAST Detector Laboratory will be also presented and discussed

Colossal barocaloric effects near room temperature in plastic crystals of neopentylglycol.

There is currently great interest in replacing the harmful volatile hydrofluorocarbon fluids used in refrigeration and air-conditioning with solid materials that display magnetocaloric, electrocaloric or mechanocaloric effects. However, the field-driven thermal changes in all of these caloric materials fall short with respect to their fluid counterparts. Here we show that plastic crystals of neopentylglycol (CH3)2C(CH2OH)2 display extremely large pressure-driven thermal changes near room temperature due to molecular reconfiguration, that these changes outperform those observed in any type of caloric material, and that these changes are comparable with those exploited commercially in hydrofluorocarbons. Our discovery of colossal barocaloric effects in a plastic crystal should bring barocaloric materials to the forefront of research and development in order to achieve safe environmentally friendly cooling without compromising performance

Recent increase of ulcerative lesions caused by Anisakis spp. in cetaceans from the north-east Atlantic

Species of Anisakis typically infect the stomach of cetaceans worldwide, often causing ulcerative lesions that may compromise the host’s health. These nematodes also cause anisakiasis or allergic reactions in humans. To assess the risks of this emerging zoonosis, data on long-term changes in Anisakis infections in cetaceans are necessary. Here, we compare the prevalence and severity of ulcerative lesions caused by Anisakis spp. in five cetacean species stranded along the north-west Spanish coast in 2017–2018 with published data from 1991–1996. Open ulcers were found in 32/ 43 short-beaked common dolphins, Delphinus delphis; 3/5 striped dolphins, Stenella coeruleoalba; 1/7 bottlenose dolphins, Tursiops truncatus; and 1/3 harbour porpoises, Phocoena phocoena mer- idionalis; a single individual of long-finned pilot whale, Globicephala melas, was found unin- fected. In common dolphins, the mean abundance of open ulcers per host was 1.1 (95% confidence interval: 0.8–1.3), with a maximum diameter (mean ± standard deviation) of 25.4 ± 16.9 mm. Stomachs with scars or extensive fibrosis putatively associated with Anisakis were detected in 14 and five animals, respectively. A molecular analysis based on the mitochondrial cytochrome c oxidase II gene using 18 worms from three cetacean species revealed single or mixed infections ofAnisakis simplex sensu stricto and Anisakis pegreffii. Compared with the per- iod 1991–1996, we found a strong increase of prevalence, abundance and extension of ulcerative lesions in most cetacean species. Anisakis populations could have increased in the study area over the last decades, although we cannot rule out that a higher environmental stress has also boosted the pathological effects of these parasites.En prens

Beyond small-scale transients: a closer look at the diffuse quiet solar corona

Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. We seek to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configuration from the more well-studied dynamic coronal features. We analyze a time series of observations from Solar Orbiter's High Resolution Imager in the Extreme Ultraviolet to quantify the characterization of the diffuse corona at high spatial and temporal resolutions. We then compare this to the dynamic features within the field of view, mainly a coronal bright point. We find that the diffuse corona lacks visible structuring, such as small embedded loops, and that this is persistent over the 25 min duration of the observation. The intensity fluctuations of the diffuse corona, which are within +/-5%, are significantly smaller in comparison to the coronal bright point. Yet, the total intensity observed in the diffuse corona is of the same order as the bright point. It seems inconsistent with our data that the diffuse corona is a composition of small loops or jets or that it is driven by discrete small heating events that follow a power-law-like distribution. We speculate that small-scale processes like MHD turbulence might be energizing the diffuse regions, but at this point we cannot offer a conclusive explanation for the nature of this feature.Comment: Accepted for publication in A&A. 10 pages, 8 figure