A shared accretion instability for black holes and neutron stars.

Accretion disks around compact objects are expected to enter an unstable phase at high luminosity1. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion and refilling of the inner disk on short timescales2. Such a scenario, however, has only been quantitatively verified for a single stellar-mass black hole3-5. Although there are hints of these cycles in a few isolated cases6-10, their apparent absence in the variable emission of most bright accreting neutron stars and black holes has been a continuing puzzle11. Here we report the presence of the same multiwavelength instability around an accreting neutron star. Moreover, we show that the variability across the electromagnetic spectrum-from radio to X-ray-of both black holes and neutron stars at high accretion rates can be explained consistently if the accretion disks are unstable, producing relativistic ejections during transitions that deplete or refill the inner disk. Such a new association allows us to identify the main physical components responsible for the fast multiwavelength variability of highly accreting compact objects.

A persistent ultraviolet outflow from an accreting neutron star binary transient.

All disc-accreting astrophysical objects produce powerful disc winds. In compact binaries containing neutron stars or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are blue-shifted X-ray absorption lines, which are preferentially seen in disc-dominated 'soft states'1,2. By contrast, optical wind-formed lines have recently been detected in 'hard states', when a hot corona dominates the luminosity3. The relationship between these signatures is unknown, and no erupting system has as yet revealed wind-formed lines between the X-ray and optical bands, despite the many strong resonance transitions in this ultraviolet (UV) region4. Here we report that the transient neutron star binary Swift J1858.6-0814 exhibits wind-formed, blue-shifted absorption lines associated with C IV, N V and He II in time-resolved UV spectroscopy during a luminous hard state, which we interpret as a warm, moderately ionized outflow component in this state. Simultaneously observed optical lines also display transient blue-shifted absorption. Decomposing the UV data into constant and variable components, the blue-shifted absorption is associated with the former. This implies that the outflow is not associated with the luminous flares in the data. The joint presence of UV and optical wind features reveals a multi-phase and/or spatially stratified evaporative outflow from the outer disc5. This type of persistent mass loss across all accretion states has been predicted by radiation-hydrodynamic simulations6 and helps to explain the shorter-than-expected duration of outbursts7.

Contemporary reconstruction of a severe neuropathic foot burn injury.

The neuropathic foot in diabetic patients constitutes a special clinical entity that needs particular care and ministration. A burn on such a foot requires special care and attention in order to avoid amputation, especially when the burn is a deep partial or a full-thickness burn. The indication for early excision and coverage of a diabetic foot is taken under consideration in clinical practice. An 80-year-old male diabetic patient with deep partial and full-thickness burns on both his feet after a long hot footbath is presented. Even though feet appearance indicated the need for amputation of both feet, we performed gradual surgical debridement and primary coverage with human skin allografts. Both feet were finally covered with partial thickness skin grafts. Considering age, general condition and severity of the burn injuries, the final results were very satisfactory. We believe that the gamma-radiated allograft is another useful adjunct to the reconstructive armamentarium of the surgeon.

Les pieds du patient souffrant de neuropathie diabétique nécessitent des soins spécifiques. Le traitement d'une brûlure profonde de tels pieds a pour but d'en éviter l'amputation, l'indication d'excisiongreffe précoce étant systématiquement à évoquer. Nous présentant la cas d'une patiente diabétique de 80 ans ayant subi des brûlures profondes des 2 pieds du fait d'un bain trop chaud. Alors même que l'aspect des brûlures laissait craindre la nécessité d'une amputation, nous avons choisi des excisions réitérées avec couverture par allogreffe avant autogreffe dont les résultats, compte tenu de l'âge, de la comorbidité et de la profondeur de la brûlure, sont considérés comme satisfaisants. Les allogreffes irradiées représentent un élément utile dans l'arsenal thérapeutique du chirurgien brûlologue.

Water quality modelling of the Mekong River basin: Climate change and socioeconomics drive flow and nutrient flux changes to the Mekong Delta.

The Mekong delta is recognised as one of the world's most vulnerable mega-deltas, being subject to a range of environmental pressures including sea level rise, increasing population, and changes in flows and nutrients from its upland catchment. With changing climate and socioeconomics there is a need to assess how the Mekong catchment will be affected in terms of the delivery of water and nutrients into the delta system. Here we apply the Integrated Catchment model (INCA) to the whole Mekong River Basin to simulate flow and water quality, including nitrate, ammonia, total phosphorus and soluble reactive phosphorus. The impacts of climate change on all these variables have been assessed across 24 river reaches ranging from the Himalayas down to the delta in Vietnam. We used the UK Met Office PRECIS regionally coupled climate model to downscale precipitation and temperature to the Mekong catchment. This was accomplished using the Global Circulation Model GFDL-CM to provide the boundary conditions under two carbon control strategies, namely representative concentration pathways (RCP) 4.5 and a RCP 8.5 scenario. The RCP 4.5 scenario represents the carbon strategy required to meet the Paris Accord, which aims to limit peak global temperatures to below a 2 °C rise whilst seeking to pursue options that limit temperature rise to 1.5 °C. The RCP 8.5 scenario is associated with a larger 3-4 °C rise. In addition, we also constructed a range of socio-economic scenarios to investigate the potential impacts of changing population, atmospheric pollution, economic growth and land use change up to the 2050s. Results of INCA simulations indicate increases in mean flows of up to 24%, with flood flows in the monsoon period increasing by up to 27%, but with increasing periods of drought up to 2050. A shift in the timing of the monsoon is also simulated, with a 4 week advance in the onset of monsoon flows on average. Decreases in nitrogen and phosphorus concentrations occur primarily due to flow dilution, but fluxes of these nutrients also increase by 5%, which reflects the changing flow, land use change and population changes.

Excessive single lateral rectus muscle recession in the treatment of intermittent exotropia.

Ten patients with small angle intermittent exotropia of 14 to 16 prism diopters were treated by unilateral lateral rectus muscle recession of 11.5 to 12 mm on the nondominant eye. In the immediate postoperative phase, overcorrection of 4 to 6 delta gave a very good functional result. Abduction deficiency was minimal for recession up to 12 mm. This procedure should be considered as an alternative approach in the treatment of small angle intermittent exotropia showing a "basic" pattern.

Cytotoxic effects on viable human leukemic cells by combinations of lymphokine activated killer cells and monoclonal antibodies.

Earlier studies with individually phenotyped monoclonal antibody combinations and complement or lymphokine activated killer (LAK) cells showed that many acute myeloid leukemic cells were resistant to these cytotoxic agents when used singly. Therefore, a combination of both agents was studied. When the leukemic target cells were submitted to killer cells activated with 100 or 800 IU of recombinant interleukin-2 (rIL-2), only averages of 6.0 and 16.7% of the targets were killed respectively. When the remaining, refractory cells were confronted with a cocktail of individually phenotyped monoclonal antibodies and complement, an additional significant cell kill was obtained, but it amounted to only between 7.4 and 5.5% (for LAK-100 and LAK-800, respectively). In contrast, of the target cells initially refractory to the same cocktail of monoclonal antibodies, all were cross-resistant both to LAK-cells activated with 100 and to those activated with 800 IU of rIL-2. This cross-resistance was caused neither by sub-optimal LAK-cell activation, nor by antibody blocking of hypothetical LAK-cell receptors, since pre-incubation with monoclonal antibodies without complement did not inhibit LAK-cell cytotoxicity. Although only partial cross-resistance was found in the present study, it still remains that only a minority of the tumor cells could be killed. A higher in-vitro cell kill should be attempted prior to clinical trials in order to avoid clinical effects resembling those of a partial surgical tumor resection.

The effect of a calf thymus acid lysate on bone marrow cell growth in vitro.

Granulocyte-macrophage colony forming units (CFU-GM) were studied in cultures of bone marrow from 16 apparently healthy normal controls, 9 patients with the myelodysplastic syndrome, 5 patients with myeloproliferative disease and 2 with myeloma. Supernatants from non-stimulated 72 hr cultures of nonadherent mononuclear blood cells ("lymphocytes") stimulated the forming of an average of 38.4 colonies per 100,000 cells from normal marrow. The addition of GIBCO's commercial conditioned medium or of a medium produced by lymphocytes stimulated with different concentrations (5, 10 and 20 mcg/ml) of an acid lysate of thymus (thymomoduline), increased growth to 65.2 - 55.4 colonies (p less than 0.001 to 0.05). Similarly, a significant increase (p less than 0.05) was found in the number of clusters and colonies formed in cultures of marrow from patients with the myelodysplastic syndrome. In contrast, no growth was found when the thymus acid lysate was added directly to the bone marrow cultures, suggesting that the lysate induces the production of colony stimulating activity by lymphocytes, but does not contain it. Similarly no significant increase was found as regards the initially high number of colonies from the five patients with myeloproliferative disease, or as regards the initially low number in the two myeloma patients.