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The near-limit oscillatory behaviors on wick flames of dimethyl carbonate (DMC) with trimethyl phosphate (TMP) additions have been investigated experimentally. The experiments were conducted under a wick burner in conjunction with the limiting oxygen concentration test (wick-LOC), and the fuels were selected as typical examples of electrolyte solvents and organophosphorus compounds (OPCs) for lithium-ion batteries. The near-limit oscillating flames on the wick configuration were observed into two main characters: side-to-wake or side oscillation in for the side-stabilized flame (full flame) and wake oscillation for the wake-stabilized flame (wake flame). By tracing the flame base movement using a 240-fps camera, stable limit cycle oscillations were found in full flame cases, while the wake flame cannot sustain the oscillation for long and finally leads to global extinction. With the addition of TMP in DMC, the transition from the side-to-wake oscillation to the side oscillation was found in the unstable full flames with a linear increase in frequency and a significant drop in amplitude, while the wake oscillating flames performed increased trends for both. To clarify the dominant mechanism of TMP-added flame oscillations, laminar burning velocities of DMC+TMP mixtures were calculated at the oxygen level of each near-limit oscillating flame. The weakened flame speed with TMP addition revealed the inadequacy of buoyancy-driven mechanisms for the OPC added wick-flame. Then the wick surface temperature was measured adopting a special thermocouple arrangement to validate the thermal-diffusive promotion by TMP addition. Results showed that the heat feedback from TMP-added flames compensated for the low reactivity and provided a faster oscillation near the extinction limit.

Atsuko Ikenouchi,1,2 Yusuke Konno,1,3 Yoshihisa Fujino,3 Naoto Adachi,4 Yukihisa Kubota,4 Takaharu Azekawa,4 Hitoshi Ueda,4 Koji Edagawa,4 Eiichi Katsumoto,4 Eiichiro Goto,4 Seiji Hongo,4 Masaki Kato,5,6 Takashi Tsuboi,5,7 Norio Yasui-Furukori,5,8 Atsuo Nakagawa,5,9 Toshiaki Kikuchi,5,9 Koichiro Watanabe,5,7 Reiji Yoshimura1,5 1Department of Psychiatry, University of Occupational and Environmental Health, Japan, Kitakyushu, Japan; 2Medical Center for Dementia, Hospital of the University of Occupational and Environmental Health, Japan, Kitakyushu, Japan; 3Department of Environmental Epidemiology, Institute of Ecological Sciences, University of Occupational and Environmental Health, Japan, Kitakyushu, Japan; 4The Japanese Association of Neuro-Psychiatric Clinics, Tokyo, Japan; 5The Japanese Society of Clinical Neuropsychopharmacology, Tokyo, Japan; 6Department of Neuropsychiatry, Kansai Medical University, Osaka, Japan; 7Department of Neuropsychiatry, Kyorin University, Tokyo, Japan; 8Department of Psychiatry, Dokkyo Medical University, Tochigi, Japan; 9Department of Neuropsychiatry, Keio University, Tokyo, JapanCorrespondence: Atsuko Ikenouchi, Department of Psychiatry, University of Occupational and Environmental Health, Japan, 1-1 Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, Japan, Tel +81-93-691-7253, Fax +81-93-692-4894, Email atsuko-i@med.uoeh-u.ac.jpPurpose: To clarify the relationship between the length of unstable periods and employment status of patients with bipolar disorder.Patients and Methods: Medical records of outpatients with bipolar disorder who visited 176 member clinics of the Japanese Association of Neuro-Psychiatric Clinics were investigated during September–October 2016, and details of their medical care and employment were surveyed using a questionnaire. The odds ratios (ORs) of length of unstable period and unemployment were analyzed with a logistic regression model.Results: The study included 816 patients, of whom 707 were employed full-time (continuous employment) and 70 were unemployed (loss of employment). Univariate analysis showed that ORs were statistically significant for patients who were unstable for “almost all” of the year (OR = 10.4 [4.48– 24.28] p < 0.001), but not for “few” unstable periods (OR = 1.06 [0.56– 1.98] p = 0.849) and for “significant” unstable periods (OR = 1.65 [0.73– 3.74] p = 0.231) were not significantly different. Multivariate analysis showed that ORs were statistically “significant” for patients who were unstable for “almost all” (OR = 12.1 [4.37– 33.3] p < 0.001), but not for “few” unstable periods (OR = 1.07 [0.55– 2.07] p = 0.846) and for “significant” unstable periods (OR = 1.62 [0.66– 3.98] p = 0.290) did not differ significantly.Conclusion: Patients with bipolar disorder with a long unstable period were associated with a higher risk of unemployment.Keywords: mood disorder, loss of employment, nationwide study, real world

Theoretical and experimental works have been carried out to clarify the effect of core material on the extinction characteristics of the flame spreading over electric wires. Additionally, an attempt has been made to explain previous experimental results (Takahashi et al., 2013 [1] ) which found that Limiting Oxygen Concentration (LOC) of copper (Cu) wire is higher than that of nickel-chrome (NiCr) wire. A theoretical model is developed to discuss the heat loss mechanism in the unburned zone ahead of the gas-phase preheat zone and its validity is confirmed by measured temperature profiles along Cu, iron (Fe), and NiCr wires insulated by low-density polyethylene (LDPE). The theoretical analysis reveals that the flame spread rate is a crucial value to assess the extinction characteristics of the flame spreading over electric wires because it controls heat loss in the unburned zone. The reduction of the flame spread rate increases heat loss in the unburned zone and induces the quenching extinction as a result of extended thermal diffusion length along the electric wire. It is also found that a highly conductive wire increases heat loss rather than poorly conductive wire even under the same flame spread rate. Such characteristics are well described by a newly introduced parameter, ηf, which is a dimensionless flame spread rate derived by the present study. By using ηf, previous experimental findings [1] are successfully explained.

Two yeast strains isolated from soil collected in Hokkaido, Japan, were found to secrete two extracellular lipases that exhibited activities at both 25 and 4 °C. Both strains could utilize olive oil, rapeseed oil, lard and fish oil as sole carbon sources. The similarity of the D1/D2 domain of the large subunit ribosomal RNA (LSU rRNA) sequence of these yeast strains to that of other yeasts in the GenBank database was very low (tef1-α) sequences indicated that both strains represented a member of the Wickerhamomyces /Candida clade. Sexual reproduction was not observed. The name Wickerhamomyces psychrolipolyticus f.a., sp. nov is proposed for this newly described yeast species producing cold-active lipases. This novel species is distinguishable from the type strains of other related species, Wickerhamomyces alni, Candida ulmi and Candida quercuum due to their abilities to grow at 4 to 30 °C, to produce lipase that is active also at 4 °C and to assimilate soluble starch.

Combustion of electric wires is the most probable cause of fire in human space activities. Therefore, the fire performance of electric wires in microgravity conditions must be thoroughly analyzed. This study investigates the opposed-flow flame spread and its limits in electric wires preheated by external radiation, under both normal gravity and microgravity, to understand their fire performance when exposed to external heat sources in such gravity conditions. The experiments were performed on low-density polyethylene (LDPE)-insulated copper (Cu) wires having an outer diameter of 4 mm and differing in core diameter (2.5 and 0.7 mm, corresponding to insulation thicknesses of 0.75 and 1.65 mm, respectively). Both standard and black LDPE insulations were used to study the effect of radiation absorption on the wire preheating and subsequent flame spread. The comparison of the flame spread limits revealed that the wire with the thicker Cu core was less flammable under both normal gravity and microgravity; in particular, its flammability further decreased in the case of microgravity, in contrast with thinner electric wires (~ 1 mm outer diameter), which exhibited higher flammability in the same gravity condition. These results suggest that different mechanisms, for thicker and thinner wires, determining the critical conditions to sustain flame spread under microgravity. This study provides valuable information about the fire performance of electric wires in space gravity.

This study examined the association between increased alcohol consumption and telecommuting, comparing employees who expressed a preference for telecommuting and those who did not.We conducted an internet monitor survey. Responses from 20 395 of the 33 302 participants were included in the final sample. Participants were asked about their desire for and frequency of telecommuting, and about changes in alcohol consumption under the COVID-19 pandemic. Data were analyzed by logistic regression analysis.The ratio of increased drinking in those who telecommuted at least once a week was significantly different (OR = 1.29, 95% CI 1.16-1.43, p .001). The ratio of increased drinking in participants for whom telecommuting was not preferred was significantly different (OR = 1.08, 95%CI 1.02-1.14, p = .002). Since the interaction term was significant in preliminary analysis, stratification was performed. Participants who telecommuted despite preferring not to do so reported significantly increased alcohol consumption, as revealed by a multivariate analysis (OR = 1.53, 95% CI 1.18-2.00, p .001). Participants who expressed a preference for telecommuting showed no such increase (OR = 1.12, 95% CI 0.98-1.27, p = .074).Under the COVID-19 pandemic, telecommuting that involves a mismatch with employee preference for way of working may be a new risk factor for problematic drinking.

BackgroundThere are increasing concerns that prevention measures against coronavirus disease 2019 (COVID-19) such as social distancing and telework are leading to loneliness and poor lifestyle habits like increased alcohol consumption. The purpose of this study was to assess whether loneliness reported among workers during the COVID-19 pandemic is associated with changes in alcohol consumption.MethodsThe study comprised a cross-sectional, online survey of 27,036 workers between December 22 and 26, 2020. A questionnaire was used to assess loneliness, usual alcohol consumption and whether that consumption had changed. The odds ratios (ORs) were estimated by logistic regression analysis.ResultsA total of 2831 (10.5%) workers indicated they had increased alcohol consumption during the pandemic. Increased alcohol consumption was significantly associated with loneliness (OR=1.94, 95%CI 1.70–2.21). This association held true for those who indicated they were drinking two or more days per week (OR=1.98 95%CI 1.71–2.30) and those who drank less than one day per week (OR=1.51 95%CI 0.71–3.25). In contrast, there was no association between increased drinking and loneliness among those who indicated they hardly ever drank (OR=1.22 95%CI 0.55–2.72).ConclusionsAmong those with a drinking habit, increased alcohol consumption is associated with loneliness.

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has been linked to a rise in loneliness. Loneliness is associated with sleep-related problems, which in turn can be a risk factor for various psychiatric disorders. However, it is unclear whether loneliness is linked to sleep-related problems during the pandemic. Here, we studied the association between loneliness and sleep-related problems during the COVID-19 pandemic in Japan.MethodsA total of 33,302 individuals who indicated they were employed were surveyed online. The survey responses of 27,036 participants were analyzed. Odds ratios (ORs) were estimated using univariate and multiple logistic regression analyses.ResultsOf those analyzed, 2,750 (10.2%) experienced feelings of loneliness. Further, sleep-related problems were significantly more common among those who felt lonely both in the short term (more than 3 days) and the long term (more than 3 months). The OR was much weaker after adjusting for factors related to interpersonal connections, such as family and friendships, than after adjusting for factors related to socioeconomic status.ConclusionsLoneliness may be a risk factor for sleep-related problems in the COVID-19 pandemic. Having connections with family and friends may have a moderating effect on the occurrence of sleep-related problems.

This work studied the piloted ignition of electrical wires in both normal gravity and microgravity using the laser-induced spark. Unique experiments were conducted in the microgravity parabolic flight with laboratory wires under the oxygen concentration of 14–21% and external radiation of up to 15.9 kW/m2. The wire sample consists of a 2.5-mm thick core, using the solid copper (Cu) or the hollow stainless steel (SS) tube, and a 0.75-mm thick black polyethylene (PE) insulation. This is the first piloted-ignition experiment on solid fuel in microgravity with the laser-induced spark as the pilot. Experimental results show that regardless of the oxygen level, the ignition delay time is always smaller in microgravity than in normal gravity, indicating a higher fire risk in the microgravity space environment. As the heat flux and the oxygen concentration increase, auto-ignition is observed. Moreover, if the core is exposed to the external heating source, it can heat the insulation to promote the ignition, different from the heat sink found in past ignition research. This unique research provides valuable information about the fire risk of electrical wire in microgravity and future long-term space travel.

The downward flame spread over laboratory electric wire under various oxygen concentrations has been investigated experimentally to improve our knowledge of electric-wire combustion. Two kinds of electrical wire (low-density-polyethylene (LDPE)-insulated copper (Cu) and nickel-chrome (NiCr)) are used in this study. The oxygen concentration of the mixture stream (O2 and N2) in the test section is varied between 15 and 41 vol%. Opposed-flow velocity in the test section is fixed at 15 cm/s. For NiCr wire, the flame spread rate (Vf) and flame length (Lf) monotonically increase with oxygen concentration. For Cu wire, both Vf and Lf show non-monotonic behavior against oxygen concentration. Most interestingly, Vf decreases with oxygen concentration increase in the 25–31% range. Theoretical analysis shows two regimes of variation of Vf with oxygen concentration: the “temperature-dependent regime (TDR)” and the “negative-oxygen-dependent regime (NOR)”. The non-monotonic behavior of Vf against oxygen concentration for Cu can be explained by the controlling mechanism behind TDR and NOR. However, experimental results show one more regime above 31% oxygen concentration that cannot be explained by the theory proposed in this work, namely the “soot-generation-dependent regime (SGR)”; here, radiation from the flame and soot deposit plays a dominant role in flame spread.

Yusuke Konno,1,2 Yoshihisa Fujino,2 Atsuko Ikenouchi,1,3 Naoto Adachi,4 Yukihisa Kubota,4 Takaharu Azekawa,4 Hitoshi Ueda,4 Koji Edagawa,4 Eiichi Katsumoto,4 Eiichiro Goto,4 Seiji Hongo,4 Masaki Kato,5,6 Takashi Tsuboi,5,7 Norio Yasui-Furukori,5,8 Atsuo Nakagawa,5,9 Toshiaki Kikuchi,5,9 Koichiro Watanabe,5,7 Reiji Yoshimura1,5 1Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan; 2Department of Environmental Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan; 3Medical Center for Dementia, University Hospital of Occupational and Environmental Health, Kitakyushu, Japan; 4The Japanese Association of Neuro-Psychiatric Clinics, Tokyo, Japan; 5The Japanese Society of Clinical Neuropsychopharmacology, Tokyo, Japan; 6Department of Neuropsychiatry, Kansai Medical University, Osaka, Japan; 7Department of Neuropsychiatry, Kyorin University School of Medicine, Tokyo, Japan; 8Department of Psychiatry, Dokkyo Medical University, Tochigi, Japan; 9Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, JapanCorrespondence: Yusuke KonnoDepartment of Psychiatry, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, JapanTel +81-93-691-7401Fax +81-93-692-4894Email yu-konno@med.uoeh-u.ac.jpObjective: The objective of this study was to clarify the relationship between mood episode and employment in patients with bipolar disorder to help improve their employment status.Methods: All medical records of patients with bipolar disorder who visited 176 member clinics of the Japanese Association of Neuro-Psychiatric Clinics in September–October 2016 were investigated in September–October 2017. Details of the medical care received were investigated using a survey sheet, which included employment status. Odds ratios of mood episodes for employment status were analyzed using a logistic regression model.Results: Among patients aged 60 years or less, 2292 described their occupation. On univariate analysis, odds ratios were statistically significant for depressive episode (OR = 2.68 [1.50– 4.78] p = 0.001) and manic episode (OR = 2.64 [1.07– 6.47] p = 0.034), whereas no significant difference was noted for mixed episode (OR = 1.72 [0.69– 4.33] p = 0.246). On multivariate analysis, odds ratios were statistically significant for depressive episode (OR = 2.16 [1.13– 4.13], p = 0.020) and manic episode (OR = 3.55 [1.36– 9.25], p = 0.010), whereas no significant difference was noted for mixed episode (OR = 1.83 [0.65– 5.14] p = 0.254).Conclusion: Employment status among these patients with bipolar disorder receiving outpatient treatment was 43.5%. Compared to remission episodes, manic and depressive episodes were associated with a higher risk of unemployment.Keywords: mood disorder, continuous employment, occupational health, Japan

The purpose of this study was to examine the association between loneliness and psychological distress during the COVID-19 pandemic in Japan. We conducted a cross-sectional, online study from 22 to 26 December 2020. A total of 27,036 participants, all employed at the time of the survey, were included in the analysis. Participants were asked if they felt loneliness in a single-item question. The Kessler 6 (K6) was used to assess psychological distress defined as K6 scores of 5 or higher, and 13 or higher. The odds ratios (ORs) of psychological distress associated with loneliness were estimated using a multilevel logistic model nested in the prefecture of residence, with adjustment for age, sex, marital status, equivalent income, educational level, smoking, alcohol consumption, job type, number of workplace employees, and cumulative incidence rate of COVID-19 in the prefecture. Communication with friends, acquaintances, and family was strongly associated with psychological distress, so we adjusted for these factors and eating meals alone. Results showed a significant association between loneliness and psychological distress (OR = 36.62, 95%CI = 32.95-40.69). Lack of friends to talk to, lack of acquaintances to ask for help, and lack of people to communicate with through social networking sites were all strongly associated with psychological distress, as were family time and solitary eating. Even after adjusting for these factors, loneliness was still strongly associated with psychological distress (OR = 29.36, 95%CI = 26.44-32.98). The association between loneliness during the COVID-19 pandemic and psychological distress indicates the need for intervention.

The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA is designed to detect gamma rays between 20 GeV and a few TeV with a 23-meter diameter mirror. We have developed the focal plane camera of the first LST, which has 1855 photomultiplier tubes (PMTs) and the readout system which samples a PMT waveform at GHz with switched capacitor arrays, Domino Ring Sampler ver4 (DRS4). To measure the precise pulse charge and arrival time of Cherenkov signals, we developed a method to calibrate the output voltage of DRS4 and the sampling time interval, as well as an analysis method to correct the spike noise of DRS4. Since the first LST was inaugurated in 2018, we have performed the commissioning tests and calibrated the camera. We characterised the camera in terms of the charge pedestal under various conditions of the night sky background, the charge resolution of each pixel, the charge uniformity of the whole camera, and the time resolutions with a test pulse and calibration laser., 14 pages, 13 figures, Proceedings of the SPIE Astronomical Telescopes + Instrumentation, 114470H (2020)

Detection of low-intensity light relies on the conversion of photons to photoelectrons, which are then multiplied and detected as an electrical signal. To measure the actual intensity of the light, one must know the factor by which the photoelectrons have been multiplied. To obtain this amplification factor, we have developed a procedure for estimating precisely the signal caused by a single photoelectron. The method utilizes the fact that the photoelectrons conform to a Poisson distribution. The average signal produced by a single photoelectron can then be estimated from the number of noise events, without requiring analysis of the distribution of the signal produced by a single photoelectron. The signal produced by one or more photoelectrons can be estimated experimentally without any assumptions. This technique, and an example of the analysis of a signal from a photomultiplier tube, are described in this study., Comment: 18 pages, 6 figures

In electrical wires with insulations that burn and melt, the dripping of molten insulation can change the wire fire behavior, ignite nearby objects, and enhance the fire spread. Dripping is a result of gravity and depends on the insulation type of the wire and its orientation. In this work, the opposed flame spread over simulated electrical wires was studied with emphasis on the effect of the core and insulation type, and the melting and dripping of insulation. To facilitate the study, “laboratory” wires with polyethylene (PE) as insulation, were selected for the experiments. Horizontal and vertical wires of 8- and 9-mm diameter with soild copper (Cu) and hollow stainless steel (SS) cores and two types of PE insulations, low density and high density, were tested. The sizes of the laboratory wires were selected to facilitate the study of the effect of the type of insulation, the ratio of insulation to core thickness, or the thermal properties of the core, on the wire fire behaviors. Experimental results show a strong dependence of wire orientation on molten insulation dripping and flame spread. For horizontal wires, the flame spread is faster with Cu core than SS core because of a larger heat transfer ahead of the flame through the core. For vertical wires, the flame spread rate is dominated by the downward dripping of the molten insulation, but is comparatively not sensitive to the core material. Increasing the opposed flow speed, the flame gets closer to the wire which enhances the heating from Cu core and locally increases the flame spread. The effects of other parameters such as oxygen concentration, wire diameter, and insulation material are also discussed. This work provides important support to a larger project aimed at studying the fire behavior of electrical wires in a spacecraft environment. Without gravity, the dripping of molten material will not occur in a spacecraft, thus, characteristics of the flame spread process over a wire insulation material that melts during the spread of the flame will be drastically different on Earth or in a spacecraft.

The purpose of this study was to examine the association between loneliness and psychological distress during the COVID-19 pandemic in Japan. We conducted a cross-sectional online study from 22 to 26 December 2020. A total of 27,036 participants, all employed at the time, were included in the analysis. Participants were asked if they felt loneliness in a single-item question. The Kessler 6 (K6) was used to assess psychological distress, defined as mild for K6 scores of 5 to 12 and severe for 13 or higher. The odds ratios (ORs) of psychological distress associated with loneliness were estimated using a multilevel logistic model nested in the prefecture of residence, with adjustment for age, sex, marital status, equivalent income, educational level, smoking, alcohol consumption, job type, number of workplace employees, and cumulative incidence rate of COVID-19 in the prefecture. Communication with friends, acquaintances, and family was strongly associated with psychological distress, so we adjusted for these factors and eating meals alone. Results showed a significant association between loneliness and psychological distress (OR = 36.62, 95% CI = 32.95-40.69). Lack of friends to talk to, lack of acquaintances to ask for help, and lack of people to communicate with through social networking sites were all strongly associated with psychological distress, as were family time and solitary eating. Even after adjusting for these factors, loneliness remained strongly associated with psychological distress (OR = 29.36, 95% CI = 26.44-32.98). The association between loneliness during the COVID-19 pandemic and psychological distress indicates the need for intervention.

[Aims] The aim of this study is to search for evidence of a common emission engine between radio giant pulses (GPs) and very-high-energy (VHE, E > 100 GeV) γ-rays from the Crab pulsar., [Methods] We performed 16 h of simultaneous observations of the Crab pulsar at 1.4 GHz with the Effelsberg radio telescope and the Westerbork Synthesis Radio Telescope (WSRT), and at energies above 60 GeV we used the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes. We searched for a statistical correlation between the radio and VHE γ-ray emission with search windows of different lengths and different time lags to the arrival times of a radio GP. A dedicated search for an enhancement in the number of VHE γ-rays correlated with the occurrence of radio GPs was carried out separately for the P1 and P2 phase ranges, respectively., [Results] In the radio data sample, 99444 radio GPs were detected. We find no significant correlation between the GPs and VHE photons in any of the search windows. Depending on phase cuts and the chosen search windows, we find upper limits at a 95% confidence level on an increase in VHE γ-ray events correlated with radio GPs between 7% and 61% of the average Crab pulsar VHE flux for the P1 and P2 phase ranges, respectively. This puts upper limits on the flux increase during a radio GP between 12% and 2900% of the pulsed VHE flux, depending on the search window duration and phase cuts. This is the most stringent upper limit on a correlation between γ-ray emission and radio GPs reported so far., The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009-00064), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project 09/176 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ.

The effect of ambient pressure on flame spread and insulation dripping of copper-cored, LDPE-insulated wires exposed to opposed airflows was investigated to increase understanding of electrical wire fire hazards in spacecraft environments. Utilized wire samples consisted of 0.64 mm-diameter copper cores surrounded by 4 mm-outer diameter LDPE insulation sheaths. The wire characteristics were selected for comparison with future experiments planned in the International Space Station (ISS) with similar wires. Environmental pressure was varied from sub-atmospheric (40 kPa) to atmospheric (100 kPa). Wires oriented horizontally were exposed to opposed airflows with speeds of 10 or 20 cm/s. Results showed that flame spread rates increase with pressure and decrease with increasing opposed flow speeds. Melted and burning insulation left behind by flame spread dripped with a frequency that increased with pressure; the total mass dripped decreased with pressure. It was also found that lower flows produced more frequent dripping with less total mass dripped, and higher flows produced the opposite. Coincidingly, as the mass of dripped insulation increased, the flame spread rate decreased. Comparison of present results with those from studies with different wire samples show that the effect of environmental parameters on flame spread and insulation dripping depends strongly on core conductivity and core/insulation diameters. Consequently, care should be taken in extending results obtained from specific wire tests to other wires without justification.

The Cherenkov Telescope Array (CTA) is the next generation VHE γ-ray observatory which will improve the currently available sensitivity by a factor of 10 in the range 100 GeV to 10 TeV. The array consists of different types of telescopes, called large size telescope (LST), medium size telescope (MST) and small size telescope (SST). A LST prototype is currently being built and will be installed at the Observatorio Roque de los Muchachos, island of La Palma, Canary islands, Spain. The readout system for the LST prototype has been designed and around 300 readout boards will be produced in the coming months. In this note we describe an automated quality control system able to measure basic performance parameters and quickly identify faulty boards.

To quantify the flammability limits of organic electrolyte solvents used in lithium-ion batteries, a unique wick combustion system was developed in conjunction with limiting oxygen concentration (LOC) of candle-like flame, named wick-LOC method. By controlling the oxygen-nitrogen ratio of external flow of the wick diffusion flame, the flammability limits (LOC) of electrolyte solvents were determined experimentally. To provide reproducible results under specified conditions, the effects of axial flow velocity, exposed wick length and elapsed time after ignition on the wick-LOC were studied, and the proper experimental conditions were selected for further applications. To validate the reliability of wick-LOC in flammability evaluation, correlation analyses to other flammability properties (flash point, auto-ignition temperature, the heat of combustion and other types of LOC) were conducted. The wick-LOC method was then applied to quantify the flammability of mixed solvents. The linear changes of wick-LOC with mixing ratios were found in the mixture of linear and cyclic carbonates, while the non-linear trends were found in carbonate-ether mixed solvents. To evaluate the flame-retardant effectiveness of organophosphorus compounds (OPCs) as additives in electrolyte solvents, a series of tests were conducted. Results showed that small amounts of OPCs had significant flame-retardant effects, but the efficiency decreased with the higher OPC additions. The effectiveness of four OPCs was distinguished as well. The results of this work provided valuable information about the flammability limits of single and mixed electrolyte solvents, and it may be useful for designing electrolyte balanced in both performance and safety.

Ovarian cancer is the most aggressive female reproductive tract tumours. Taxane (paclitaxel; TX) is widely used for ovarian cancer treatment. However, ovarian cancers often acquire chemoresistance. MicroRNAs (miR) have been reported to mediate many tumours'chemoresistance. We investigated the role of miR-363 in the chemoresistance of the ovarian cancer cell line, KF, and its TX-resistant derivative (KF-TX) cells. QRT-PCR indicated that miR-363 was upregulated in KF-TX cells, and introduction of miR-363 into sensitive ovarian cancer cells confers TX-resistance and significantly inhibited the expression of the Hippo member, LATS2, as indicated by viability, clonogenic assay and expression analysis. Furthermore, we validated the role of LATS2 in TX-response by sh-based silencing, which also confers TX-resistance to the ovarian cancer cells. On the other hand, specific inhibitor against miR-363 restored the response to TX in the resistant cells. In addition, miR-363 was found to bind to the 3'-UTR of LATS2 mRNA, confirming that miR-363 directly targets LATS2 as indicated by dual luciferase assay. RT-PCR-based evaluation of miR-363 in a panel of human ovarian tumours revealed its upregulation in most of the tumour tissues identified as resistant while it was downregulated in most of the tissues identified as sensitive ones. Moreover, higher levels of miR-363 in human ovarian cancer specimens were significantly correlated with TX chemoresistance. Taken together, our study reveals the involvement of miR-363 in chemoresistance by targeting LATS2 in ovarian cancers, raising the possibility that combination therapy with a miR-363 inhibitor and TX may increase TX efficacy and reduce the chance of TX-resistance.

A neutrino with energy of $\sim$290 TeV, IceCube-170922A, was detected in coincidence with the BL Lac object TXS~0506+056 during enhanced gamma-ray activity, with chance coincidence being rejected at $\sim 3\sigma$ level. We monitored the object in the very-high-energy (VHE) band with the MAGIC telescopes for $\sim$41 hours from 1.3 to 40.4 days after the neutrino detection. Day-timescale variability is clearly resolved. We interpret the quasi-simultaneous neutrino and broadband electromagnetic observations with a novel one-zone lepto-hadronic model, based on interactions of electrons and protons co-accelerated in the jet with external photons originating from a slow-moving plasma sheath surrounding the faster jet spine. We can reproduce the multiwavelength spectra of TXS 0506+056 with neutrino rate and energy compatible with IceCube-170922A, and with plausible values for the jet power of $\sim 10^{45} - 4 \times 10^{46} {\rm erg \ s^{-1}}$. The steep spectrum observed by MAGIC is concordant with internal $\gamma\gamma$ absorption above a few tens of GeV entailed by photohadronic production of a $\sim$290 TeV neutrino, corroborating a genuine connection between the multi-messenger signals. In contrast to previous predictions of predominantly hadronic emission from neutrino sources, the gamma-rays can be mostly ascribed to inverse Compton up-scattering of external photons by accelerated electrons. The X-ray and VHE bands provide crucial constraints on the emission from both accelerated electrons and protons. We infer that the maximum energy of protons in the jet co-moving frame can be in the range $\sim 10^{14}$ to $10^{18}$ eV., Comment: 11 pages, 3 figues, 3 tables, Accepted for publication in ApJL. Major changes in the revised Version: corrected author list

Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsähovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC. Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E > 100 GeV). In the constructed SED, the Swift-XRT+NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of z = 0:31 ± 0:02 ± 0:05, confirming the literature value. Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling. © ESO 2018., We would like to thank the Instituto de Astrofisica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009-00064), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia "Severo Ochoa" SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia "Maria de Maeztu" MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq and FAPERJ. The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat a l'Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucleaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d'Etudes Spatiales in France. This research was supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Universities Space Research Association through a contract with NASA. We thank the Swift team duty scientists and science planners., The Metsahovi team acknowledges the support from the Academy of Finland to our observing projects (numbers 212656, 210338, 121148, and others). The VLBA is an instrument of the Long Baseline Observatory. The Long Baseline Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc. The Sub-millimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. The OVRO 40-m monitoring program is supported in part by NASA grants NNX08AW31G, NNX11A043G and NNX14AQ89G, and NSF grants AST-0808050 and AST-1109911. The St. Petersburg University team acknowledges support from Russian Science Foundation grant 17-12-01029. The BU group acknowledges support by NASA under Fermi Guest Investigator grant NNX14AQ58G and by NSF under grant AST-1615796. Part of this work was done with funding by the UK Space Agency. The VLBA is an instrument of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The PRISM (Perkins Re-Imaging SysteM) camera at Lowell Observatory was developed by K. Janes et al. at BU and Lowell Observatory, with funding from the NSF, BU, and Lowell Observatory. This paper makes use of data obtained with the 100m Effelsberg radio-telescope, which is operated by the Max-Planck-Institut fur Radioastronomy (MPIfR) in Bonn (Germany). Part of this work is based on archival data, software or online services provided by the ASI Science Data Center (ASDC). PYRAF is a product of the Space Telescope Science Institute, which is operated by AURA for NASA. This paper is partly based on observations carried out with the IRAM 30 m. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). IA acknowledges support by a Ramon y Cajal grant of the Ministerio de Economia, Industria y Competitividad (MINECO) of Spain. The research at the IAA-CSIC was supported in part by the MINECO through grants AYA2016-80889-P, AYA2013-40825-P, and AYA2010-14844, and by the regional government of Andalucia through grant P09-FQM-4784. The Liverpool Telescope is operated by JMU with financial support from the UK-STFC.

Imaging Atmospheric Cherenkov Telescopes (IACT) are designed to detect γ -ray photons in the very-high energy (VHE) band from 50 GeV to more than 10 TeV. The few degree-scale field of view and the good angular resolution γ -ray photons of IACTs using Crab Nebula data collected with the MAGIC stereoscopic system. Through a careful description of the background and response of the instrument we can build the γ -ray PSF corrected for the angular acceptance. We find a good analytical model describing the γ -ray PSF for IACTs and assess its stability.

Astroparticle physics 102, 77 - 88 (2018). doi:10.1016/j.astropartphys.2018.05.002, A search for tau neutrino induced showers with the MAGIC telescopes is presented. The MAGIC telescopes located at an altitude of 2200 m a.s.l. in the Canary Island of La Palma, can point towards the horizon or a few degrees below across an azimuthal range of about 80°. This provides a possibility to search for air showers induced by tau leptons arising from interactions of tau neutrinos in the Earth crust or the surrounding ocean. In this paper we show how such air showers can be discriminated from the background of very inclined hadronic showers by using Monte Carlo simulations. Taking into account the orography of the site, the point source acceptance and the event rates expected have been calculated for a sample of generic neutrino fluxes from photo-hadronic interactions in AGNs. The analysis of about 30 h of data taken towards the sea leads to a 90% C.L. point source limit for tau neutrinos in the energy range from 1.0 × 10$^{15}$ eV to 3.0 × 10$^{18}$ eV of about $E^{2}_{\nu_{\tau}} \times \phi (E_{\nu_{\tau}}) < 2.0 \times 10^{-4}$ GeV cm$^{-2} s^{-1}$ for an assumed power-law neutrino spectrum with spectral index $\gamma =−2$. However, with 300 h and in case of an optimistic neutrino flare model, limits of the level down to $E^{2}_{\nu_{\tau}} \times \phi (E_{\nu_{\tau}}) < 8.4 \times 10^{-6}$ GeV cm$^{-2} s^{-1}$ can be expected., Published by Elsevier Science, Amsterdam [u.a.]

The MAGIC telescopes observed S2 0109+22 in 2015 July during its flaring activity in high energy gamma rays observed by Fermi-LAT. We analyse the MAGIC data to characterise the very high energy (VHE) gamma-ray emission of S2 0109+22, which belongs to the subclass of intermediate synchrotron peak (ISP) BL Lac objects. We study the multi-frequency emission in order to investigate the source classification. Finally, we compare the source long-term behaviour to other VHE gamma-ray emitting (TeV) blazars. We performed a temporal and spectral analysis of the data centred around the MAGIC interval of observation (MJD 57225-57231). Long-term radio and optical data have also been investigated using the discrete correlation function. The redshift of the source is estimated through optical host-galaxy imaging and also using the amount of VHE gamma-ray absorption. The quasi-simultaneous multi-frequency spectral energy distribution (SED) is modelled with the conventional one-zone synchrotron self-Compton (SSC) model. MAGIC observations resulted in the detection of the source at a significance level of $5.3\,\sigma$. The VHE gamma-ray emission of S2 0109+22 is variable on a daily time scale. VHE gamma-ray luminosity of the source is lower than the average of TeV BL Lacs. The optical polarization, and long-term optical/radio behaviour of the source are different from the general population of TeV blazars. All these findings agree with the classification of the source as an ISP BL Lac object. We estimate the source redshift as $z = 0.36 \pm 0.07$. The SSC parameters describing the SED are rather typical for blazars., Comment: 15 pages, 10 figures, Corresponding authors: Fallah Ramazani, V. (vafara@utu.fi), Hovatta, T. (talvikki.hovatta@utu.fi), Lindfors, E. (elilin@utu.fi) and Nilsson, K. (kani@utu.fi)

The very high energy (VHE ¿ 100 GeV) -ray MAGIC observations of the blazar S4 0954+65, were triggered by an exceptionally high flux state of emission in the optical. This blazar has a disputed redshift of z = 0.368 or z ¿ 0.45 and an uncertain classification among blazar subclasses. The exceptional source state described here makes for an excellent opportunity to understand physical processes in the jet of S4 0954+65 and thus contribute to its classification. Methods. We investigated the multiwavelength (MWL) light curve and spectral energy distribution (SED) of the S4 0954+65 blazar during an enhanced state in February 2015 and have put it in context with possible emission scenarios. We collected photometric data in radio, optical, X-ray, and ¿-ray. We studied both the optical polarization and the inner parsec-scale jet behavior with 43 GHz data. Results. Observations with the MAGIC telescopes led to the first detection of S4 0954+65 at VHE. Simultaneous data with Fermi-LAT at high energy ¿-ray(HE, 100 MeV < E < 100 GeV) also show a period of increased activity. Imaging at 43 GHz reveals the emergence of a new feature in the radio jet in coincidence with the VHE flare. Simultaneous monitoring of the optical polarization angle reveals a rotation of approximately 100. Conclusions. The high emission state during the flare allows us to compile the simultaneous broadband SED and to characterize it in the scope of blazar jet emission models. The broadband spectrum can be modeled with an emission mechanism commonly invoked for flat spectrum radio quasars (FSRQs), that is, inverse Compton scattering on an external soft photon field from the dust torus, also known as external Compton. The light curve and SED phenomenology is consistent with an interpretation of a blob propagating through a helical structured magnetic field and eventually crossing a standing shock in the jet, a scenario typically applied to FSRQs and low-frequency peaked BL Lac objects (LBL). © ESO 2018., The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009-00064), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq, and FAPERJ. IA acknowledges support by a Ramón y Cajal grant of the Ministerio de Economía, Industria y Competitividad (MINECO) of Spain. The research at the IAA–CSIC was supported in part by the MINECO through grants AYA2016–80889–P, AYA2013–40825–P, and AYA2010–14844, and by the regional government of Andalucía through grant P09–FQM–4784.

Case presentation A 62-year-old man was diagnosed with peritoneal dialysis (PD)-related peritonitis following diarrhea and determination of a dialysate leukocyte count of 10,224/μL. We cultured peritoneal effluent and started intraperitoneal antibiotic therapy. Peritonitis immediately improved. Peritoneal effluent culture yielded Aeromonas hydrophila. The medical interview revealed that the patient kept goldfish as pets. We suspected that the fish tank water was the source of the infection, considering the association of A. hydrophila with aquatic environments. Culturing of tank water confirmed the presence of Aeromonas. Furthermore, we observed that one of the goldfish was suffering from lepidorthosis, which is commonly caused by Aeromonas, and we then confirmed that the fish's infection was caused by an aeromonad. Conclusion Aeromonas species have rarely been identified as the pathogens in PD-related peritonitis; to our knowledge, there hitherto have been no reports identifying the source of this organism. We present here the process of this infection as elucidated through investigation of the living environment of the patient.

Monthly notices of the Royal Astronomical Society 451(1), 739 - 750 (2015). doi:10.1093/mnras/stv895, The high-frequency-peaked BL Lac (HBL) 1ES 0806+524 (z = 0.138) was discovered in very high energy (VHE) γ-rays in 2008. Until now, the broad-band spectrum of 1ES 0806+524 has been only poorly characterized, in particular at high energies. We analysed multiwavelength observations from γ-rays to radio performed from 2011 January to March, which were triggered by the high activity detected at optical frequencies. These observations constitute the most precise determination of the broad-band emission of 1ES 0806+524 to date. The stereoscopic Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) observations yielded a γ-ray signal above 250 GeV of (3.7 ± 0.7) per cent of the Crab Nebula flux with a statistical significance of 9.9σ. The multiwavelength observations showed significant variability in essentially all energy bands, including a VHE γ-ray flare that lasted less than one night, which provided unprecedented evidence for short-term variability in 1ES 0806+524. The spectrum of this flare is well described by a power law with a photon index of 2.97 ± 0.29 between ∼150 GeV and 1 TeV and an integral flux of (9.3 ± 1.9) per cent of the Crab nebula flux above 250 GeV. The spectrum during the non-flaring VHE activity is compatible with the only available VHE observation performed in 2008 with VERITAS when the source was in a low optical state. The broad-band spectral energy distribution can be described with a one-zone synchrotron self-Compton model with parameters typical for HBLs, indicating that 1ES 0806+524 is not substantially different from the HBLs previously detected., Published by Oxford Univ. Press, Oxford

Peritoneal dialysis (PD)-related infections (PDIs) such as peritonitis, exit-site infection, and tunnel infection are serious complications affecting patients on PD. Because patients with diabetes (DM) and of older age have increased in number in Japan, the number of patients with visual impairment is estimated also to have increased. Near vision is necessary for performing proper PD daily care. However, no studies have reported whether visual impairment is likely to increase the risk of PDIs.Our study included 31 PD patients (16 men, 15 women; mean age: 61.5 ± 11.8 years; mean PD duration: 27.3 ± 20.3 months; 38.7% with DM; 54.8% wearing glasses) who performed their own PD care. At our facility and related facilities, we used a standard near-vision test chart, which classifies vision into 12 grades, from 0.1 (poor) to 1.5 (clear), to assess near-vision binocular visual acuity in those patients between March 2015 and September 2015. In addition, we retrospectively examined the medical records of the patients to determine their history of PDIs. We then evaluated the correlation between near-vision acuity and the incidence of PDIs.Mean measured near-vision acuity was 0.61 ± 0.29, and we observed no significant difference in the visual acuity of patients with and without DM (0.55 ± 0.31 vs. 0.63 ± 0.26 respectively, p = 0.477). In addition, we observed no significant difference in the incidence of PDIs between patients with and without DM (1.298 ± 1.609 per year vs. 1.164 ± 0.908 per year respectively, p = 0.804). We did not find a correlation between near-vision acuity and the incidence of PDIs (r = -0.071, p = 0.795).

In this work we present data from observations with the MAGIC telescopes of SN 2014J detected in January 21 2014, the closest Type Ia supernova since Imaging Air Cherenkov Telescopes started to operate. We probe the possibility of very-high-energy (VHE; $E\geq100$ GeV) gamma rays produced in the early stages of Type Ia supernova explosions. We performed follow-up observations after this supernova explosion for 5 days, between January 27 and February 2 in 2014. We search for gamma-ray signal in the energy range between 100 GeV and several TeV from the location of SN 2014J using data from a total of $\sim5.5$ hours of observations. Prospects for observing gamma-rays of hadronic origin from SN 2014J in the near future are also being addressed. No significant excess was detected from the direction of SN 2014J. Upper limits at 95$\%$ confidence level on the integral flux, assuming a power-law spectrum, d$F/$d$E\propto E^{-\Gamma}$, with a spectral index of $\Gamma=2.6$, for energies higher than 300 GeV and 700 GeV, are established at $1.3\times10^{-12}$ and $4.1\times10^{-13}$ photons~cm$^{-2}$s$^{-1}$, respectively. For the first time, upper limits on the VHE emission of a Type Ia supernova are established. The energy fraction isotropically emitted into TeV gamma rays during the first $\sim10$ days after the supernova explosion for energies greater than 300 GeV is limited to $10^{-6}$ of the total available energy budget ($\sim 10^{51}$ erg). Within the assumed theoretical scenario, the MAGIC upper limits on the VHE emission suggest that SN 2014J will not be detectable in the future by any current or planned generation of Imaging Atmospheric Cherenkov Telescopes., Comment: 5 pages, 2 figures. Accepted for publication in A&A

B1957+20 is a millisecond pulsar located in a black-widow-type compact binary system with a low-mass stellar companion. The interaction of the pulsar wind with the companion star wind and/or the interstellar plasma is expected to create plausible conditions for acceleration of electrons to TeV energies and subsequent production of very high-energy γ-rays in the inverse Compton process. We performed extensive observations with the Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) telescopes of B1957+20. We interpret results in the framework of a few different models, namely emission from the vicinity of the millisecond pulsar, the interaction of the pulsar and stellar companion wind region or bow shock nebula. No significant steady very high-energy γ-ray emission was found. We derived a 95 per cent confidence level upper limit of 3.0 × 10−12 cm−2 s−1 on the average γ-ray emission from the binary system above 200 GeV. The upper limits obtained with the MAGIC constrain, for the first time, different models of the high-energy emission in B1957+20. In particular, in the inner mixed wind nebula model with mono-energetic injection of electrons, the acceleration efficiency of electrons is constrained to be below ∼2–10 per cent of the pulsar spin-down power. For the pulsar emission, the obtained upper limits for each emission peak are well above the exponential cut-off fits to the Fermi-LAT data, extrapolated to energies above 50 GeV. The MAGIC upper limits can rule out a simple power-law tail extension through the sub-TeV energy range for the main peak seen at radio frequencies., Monthly Notices of the Royal Astronomical Society, 470 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711

The microquasar V404 Cygni underwent a series of outbursts in 2015, June 15-31, during which its flux in hard X-rays (20-40 keV) reached about 40 times the Crab Nebula flux. Because of the exceptional interest of the flaring activity from this source, observations at several wavelengths were conducted. The MAGIC telescopes, triggered by the INTEGRAL alerts, followed-up the flaring source for several nights during the period June 18-27, for more than 10 hours. One hour of observation was conducted simultaneously to a giant 22 GHz radio flare and a hint of signal at GeV energies seen by Fermi-LAT. The MAGIC observations did not show significant emission in any of the analysed time intervals. The derived flux upper limit, in the energy range 200--1250 GeV, is 4.8$\times 10^{-12}$ ph cm$^{-2}$ s$^{-1}$. We estimate the gamma-ray opacity during the flaring period, which along with our non-detection, points to an inefficient acceleration in the V404\,Cyg jets if VHE emitter is located further than $1\times 10^{10}$ cm from the compact object., Comment: 7 pages, accepted by MNRAS

The microquasar Cygnus X-1 displays the two typical soft and hard X-ray states of a black hole transient. During the latter, Cygnus X-1 shows a one-sided relativistic radio-jet. Recent detection of the system in the high energy (HE; E greater than or similar to 60 MeV) gamma-ray range with FermiLAT associates this emission with the outflow. Former MAGIC observations revealed a hint of flaring activity in the very high-energy (VHE; E greater than or similar to 100 GeV) regime during this X-ray state. We analyse ~ to 97 h of Cygnus X-1 data taken with the MAGIC telescopes between July 2007 and October 2014. To shed light on the correlation between hard X-ray and VHE gamma rays as previously suggested, we study each main X-ray state separately. We perform an orbital phase-folded analysis to look for variability in the VHE band. Additionally, to place this variability behaviour in a multiwavelength context, we compare our results with Fermi-LAT, AGILE, Swift-BAT, MAXI, RXTE-ASM, AMI and RATAN-600 data. We do not detect Cygnus X-1 in the VHE regime. We establish upper limits for each X-ray state, assuming a power-law distribution with photon index Γ = 3.2. For steady emission in the hard and soft X-ray states, we set integral upper limits at 95 %per cent confidence level for energies above 200 GeV at 2.6 x 10⁻¹² photons cm⁻² s⁻¹ and 1.0 x 10⁻¹¹ photons cm⁻² s ⁻¹, respectively. We rule out steady VHE gamma-ray emission above this energy range, at the level of theMAGIC sensitivity, originating in the interaction between the relativistic jet and the surrounding medium, while the emission above this flux level produced inside the binary still remains a valid possibility.