65 research outputs found

    Structure and management issues of the emerging ornamental fish trade in Eritrea

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    Following independence from Ethiopia in 1993, Eritrea resumed exploiting Red Sea and Arabian fish species for the ornamental trade in 1995 as a means to earn foreign exchange from sparsely exploited marine resources. This paper describes the findings of research conducted in 1997, in collaboration with the Eritrean Ministry of Fisheries. The capture, transport and export of aquarium fish were reviewed and potential impacts and the status of management were investigated through liaison with stakeholders and researchers. From 1995 to 1997 two companies exported approximately 60,000 fish per year, mainly to the USA, worth US$65,000 (export value). Seventyfive species (from 22 families) were exported. Damselfishes made up two-thirds of total exports but more valuable families (angelfishes and butterflyfishes) were more economically significant. To earn revenue for Eritrea, a 20% export tax was imposed, although this was calculated from declarations by the operators. The emerging nature of the trade allowed detailed monitoring by the Ministry of Fisheries. However, management efforts were constrained by a lack of capacity for enforcement and baseline research. Several potential effects of the trade exist but other, land-based impacts may be more pressing concerns for Eritrea’s reefs. Research priorities for management are discussed as well as the implications of mariculture of Eritrean species by other nations

    Electrocautery, diathermy, and surgical energy devices: are surgical teams at risk during the COVID-19 pandemic?

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    OBJECTIVE: The aim of the study was to provide a rapid synthesis of available data to identify the risk posed by utilizing surgical energy devices intraoperatively due to the generation of surgical smoke, an aerosol. Secondarily it aims to summarize methods to minimize potential risk to operating room staff. SUMMARY BACKGROUND DATA: Continuing operative practice during the coronavirus disease-19 (COVID-19) pandemic places the health of operating theatre staff at potential risk. SARS-CoV2 is transmitted through inhaled droplets and aerosol particles, thus posing an inhalation threat even at considerable distance. Surgical energy devices generate an aerosol of biological particular matter during use. The risk to healthcare staff through use of surgical energy devices is unknown. METHODS: This review was conducted utilizing a rapid review methodology to enable efficient generation and dissemination of information useful for concurrent clinical practice. RESULTS: There are conflicting stances on the use of energy devices and laparoscopy by different surgical governing bodies and societies. There is no definitive evidence that aerosol generated by energy devices may carry active SARS-CoV2 virus. However, investigations of other viruses have demonstrated aerosolization through energy devise use. Measures to reduce potential transmission include appropriate personal protective equipment, evacuation and filtration of surgical plume, limiting energy device use if appropriate, and adjusting endoscopic and laparoscopic practice (low CO2 pressures, evacuation through ultrafiltration systems). CONCLUSIONS: The risk of transmission of SARS-CoV2 through aerosolized surgical smoke associated with energy device use is not fully understood, however transmission is biologically plausible. Caution and appropriate measures to reduce risk to healthcare staff should be implemented when considering intraoperative use of energy devices

    Timescale-dependent X-ray to UV time lags of NGC 4593 using high-intensity XMM-Newton observations with Swift and AstroSat

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    We present a 140ks observation of NGC 4593 with XMM-Newton providing simultaneous and continuous PN X-ray and OM UV (UVW1 2910\AA) lightcurves which sample short-timescale variations better than previous observations. These observations were simultaneous with 22d of Swift X-ray and UV/optical monitoring, reported previously, and 4d of AstroSat X-ray (SXT), far (FUV 1541\AA), and near (NUV 2632\AA) UV allowing lag measurements between them and the highly-sampled XMM. From the XMM we find that UVW1 lags behind the X-rays by 29.5±\pm1.3ks, ∌\simhalf the lag previously determined from the Swift monitoring. Re-examination of the \textit{Swift} data reveals a bimodal lag distribution, with evidence for both the long and short lags. However if we detrend the Swift lightcurves by LOWESS filtering with a 5d width, only the shorter lag (23.8±\pm21.2ks) remains. The NUV observations, compared to PN and SXT, confirm the ∌\sim30ks lag found by XMM and, after 4d filtering is applied to remove the long-timescale component, the FUV shows a lag of ∌\sim23ks. The resultant new UVW1, FUV, and NUV lag spectrum extends to the X-ray band without requiring additional X-ray to UV lag offset, which if the UV arises from reprocessing of X-rays, implies direct illumination of the reprocessor. By referencing previous Swift and HST lag measurements, we obtain an X-ray to optical lag spectrum which agrees with a model using the KYNreverb disc-reprocessing code, assuming the accepted mass of 7.63×106M⊙7.63\times10^{6}M_{\odot} and a spin approaching maximum. Previously noted lag contribution from the BLR in the Balmer and Paschen continua are still prominent.Comment: 13 pages, 23 figure

    The first spectroscopic IR reverberation programme on Mrk 509

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    Near IR spectroscopic reverberation of Active Galactic Nuclei (AGN) potentially allows the IR broad line region (BLR) to be reverberated alongside the disc and dust continua, while the spectra can also reveal details of dust astro-chemistry. Here we describe results of a short pilot study (17 near-IR spectra over a 183 day period) for Mrk 509. The spectra give a luminosity-weighted dust radius of 〈Rd, lum〉 = 186 ± 4 light-days for blackbody (large grain dust), consistent with previous (photometric) reverberation campaigns, whereas carbon and silicate dust give much larger radii. We develop a method of calibrating spectral data in objects where the narrow lines are extended beyond the slit width. We demonstrate this by showing our resultant photometric band lightcurves are consistent with previous results, with a hot dust lag at >40 days in the K-band, clearly different from the accretion disc response at <20 days in the z-band. We place this limit of 40 days by demonstrating clearly that the modest variability that we do detect in the H and K-band does not reverberate on timescales of less than 40 days. We also extract the PaÎČ line lightcurve, and find a lag which is consistent with the optical BLR HÎČ line of ∌70 − 90 days. This is important as direct imaging of the near-IR BLR is now possible in a few objects, so we need to understand its relation to the better studied optical BLR

    AGN STORM 2. IV. Swift X-ray and ultraviolet/optical monitoring of Mrk 817

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    The AGN STORM 2 campaign is a large, multiwavelength reverberation mapping project designed to trace out the structure of Mrk 817 from the inner accretion disk to the broad emission line region and out to the dusty torus. As part of this campaign, Swift performed daily monitoring of Mrk 817 for approximately 15 months, obtaining observations in X-rays and six UV/optical filters. The X-ray monitoring shows that Mrk 817 was in a significantly fainter state than in previous observations, with only a brief flare where it reached prior flux levels. The X-ray spectrum is heavily obscured. The UV/optical light curves show significant variability throughout the campaign and are well correlated with one another, but uncorrelated with the X-rays. Combining the Swift UV/optical light curves with Hubble UV continuum light curves, we measure interband continuum lags, τ(λ)\tau(\lambda), that increase with increasing wavelength roughly following τ(λ)∝λ4/3\tau(\lambda) \propto \lambda^{4/3}, the dependence expected for a geometrically thin, optically thick, centrally illuminated disk. Modeling of the light curves reveals a period at the beginning of the campaign where the response of the continuum is suppressed compared to later in the light curve - the light curves are not simple shifted and scaled versions of each other. The interval of suppressed response corresponds to a period of high UV line and X-ray absorption, and reduced emission line variability amplitudes. We suggest that this indicates a significant contribution to the continuum from the broad line region gas that sees an absorbed ionizing continuum.Comment: 20 pages, 13 figures, 3 tables, accepted for publication in Ap

    An integrative review exploring decision-making factors influencing mental health nurses in the use of restraint

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    Introduction: While mechanical and manual restraint as an institutional method of control within mental health settings may be perceived to seem necessary at times, there is emergent literature highlighting the potential counter-therapeutic impact of this practice for patients as well as staff. Nurses are the professional group who are most likely to use mechanical and manual restraint methods within mental health settings. In-depth insights to understand what factors influence nurses’ decision-making related to restraint use are therefore warranted. Aim: To explore what influences mental health nurses’ decision-making in the use of restraint. Method: An integrative review using Cooper’s framework was undertaken. Results: Eight emerging themes were identified: ‘safety for all’, ‘restraint as a necessary intervention’, ‘restraint as a last resort’, ‘role conflict’, ‘maintaining control’, ‘staff composition’, ‘knowledge and perception of patient behaviours’, and ‘psychological impact’. These themes highlight how mental health nurses’ decision-making is influenced by ethical and safety responsibilities, as well as, interpersonal and staff-related factors. Conclusion: Research to further understand the experience and actualization of ‘last resort’ in the use of restraint and to provide strategies to prevent restraint use in mental health settings are needed

    AGN STORM 2: V. Anomalous Behavior of the CIV Light Curve in Mrk 817

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    An intensive reverberation mapping campaign on the Seyfert 1 galaxy Mrk817 using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) revealed significant variations in the response of the broad UV emission lines to fluctuations in the continuum emission. The response of the prominent UV emission lines changes over a ∌\sim60-day duration, resulting in distinctly different time lags in the various segments of the light curve over the 14 months observing campaign. One-dimensional echo-mapping models fit these variations if a slowly varying background is included for each emission line. These variations are more evident in the CIV light curve, which is the line least affected by intrinsic absorption in Mrk817 and least blended with neighboring emission lines. We identify five temporal windows with distinct emission line response, and measure their corresponding time delays, which range from 2 to 13 days. These temporal windows are plausibly linked to changes in the UV and X-ray obscuration occurring during these same intervals. The shortest time lags occur during periods with diminishing obscuration, whereas the longest lags occur during periods with rising obscuration. We propose that the obscuring outflow shields the ultraviolet broad lines from the ionizing continuum. The resulting change in the spectral energy distribution of the ionizing continuum, as seen by clouds at a range of distances from the nucleus, is responsible for the changes in the line response.Comment: 20 pages, 8 figures, submitted to Ap

    AGN STORM 2. I. First results: A Change in the Weather of Mrk 817

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    We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura–Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C IV and Lyα lags suggest that the accretion disk extends beyond the UV broad-line region. Unified

    The Bantustan State and the South African Transition: Militarisation, Patrimonialism and the Collapse of the Ciskei Regime, 1986-1994

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    This article examines the Ciskei bantustan and processes of state formation during the transition to democracy. In the Ciskei, the rule of Brigadier Gqozo rested on the continued support of the South African state: identified as the weakest link in the National Party’s conservative alliance, the Ciskei became the first target for the African National Congress’ mass action campaign of 1992. The struggle in the Ciskei thus had some significance for the shape of the transition. While at a constitutional level the National Party eventually conceded to the re-incorporation of the bantustans in late 1992, it continued to stall change and to bolster the bantustans through covert military operations and land transfers to bantustan elites. These dynamics of state formation are critical aspects of the history of the transition and were at the heart of the emerging political conflict in the Ciskei, which by mid-1992 was escalating into civil war. This article examines mass mobilisation, political repression and the consequences of the patrimonial militarisation of the Ciskei state in the Ciskei/ Border region. By focusing on processes of state formation and struggles over the fabric of the state, this article provides a corrective to the prevailing academic focus on the elite negotiations and argues for the value of social histories of the bantustan states for understanding the enduring legacies of these regimes

    AGN STORM 2. IV. Swift X-Ray and Ultraviolet/Optical Monitoring of Mrk 817

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    The AGN STORM 2 campaign is a large, multiwavelength reverberation mapping project designed to trace out the structure of Mrk 817 from the inner accretion disk to the broad emission line region and out to the dusty torus. As part of this campaign, Swift performed daily monitoring of Mrk 817 for approximately 15 months, obtaining observations in X-rays and six UV/optical filters. The X-ray monitoring shows that Mrk 817 was in a significantly fainter state than in previous observations, with only a brief flare where it reached prior flux levels. The X-ray spectrum is heavily obscured. The UV/optical light curves show significant variability throughout the campaign and are well correlated with one another, but uncorrelated with the X-rays. Combining the Swift UV/optical light curves with Hubble Space Telescope UV continuum light curves, we measure interband continuum lags, τ(λ), that increase with increasing wavelength roughly following τ(λ) ∝ λ 4/3, the dependence expected for a geometrically thin, optically thick, centrally illuminated disk. Modeling of the light curves reveals a period at the beginning of the campaign where the response of the continuum is suppressed compared to later in the light curve—the light curves are not simple shifted and scaled versions of each other. The interval of suppressed response corresponds to a period of high UV line and X-ray absorption, and reduced emission line variability amplitudes. We suggest that this indicates a significant contribution to the continuum from the broad-line region gas that sees an absorbed ionizing continuum
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