Synergies of THESEUS with the large facilities of the 2030s and guest observer opportunities.

The proposed THESEUS mission will vastly expand the capabilities to monitor the high-energy sky. It will specifically exploit large samples of gamma-ray bursts to probe the early universe back to the first generation of stars, and to advance multi-messenger astrophysics by detecting and localizing the counterparts of gravitational waves and cosmic neutrino sources. The combination and coordination of these activities with multi-wavelength, multi-messenger facilities expected to be operating in the 2030s will open new avenues of exploration in many areas of astrophysics, cosmology and fundamental physics, thus adding considerable strength to the overall scientific impact of THESEUS and these facilities. We discuss here a number of these powerful synergies and guest observer opportunities.

Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

Design and implementation of electron diverters for lobster eye space-based X-ray optics.

Micropore optics have recently been implemented in a lobster eye geometry as a compact X-ray telescope. Fields generated by rare-earth magnets are used to reduce the flux of energetic electrons incident upon the focal plane detector in such a setup. We present the design and implementation of the electron diverters for X-ray telescopes of two upcoming missions: the microchannel X-ray telescope onboard the space-based multiband astronomical variable objects monitor and the soft X-ray instrument onboard the solar wind magnetosphere ionosphere link explorer. Electron diverters must be configured to conform to stringent limits on their total magnetic dipole moment and be compensated for any net moment arising from manufacturing errors. The two missions have differing designs, which are presented and evaluated in terms of the fractions of electrons reaching the detector, as determined by relativistic calculations of electron trajectories. The differential flux of electrons to the detector is calculated, and the integrated electron background is determined for both designs.

Swift and NuSTAR observations of GW170817: Detection of a blue kilonova.

With the first direct detection of merging black holes in 2015, the era of gravitational wave (GW) astrophysics began. A complete picture of compact object mergers, however, requires the detection of an electromagnetic (EM) counterpart. We report ultraviolet (UV) and x-ray observations by Swift and the Nuclear Spectroscopic Telescope Array of the EM counterpart of the binary neutron star merger GW170817. The bright, rapidly fading UV emission indicates a high mass (≈0.03 solar masses) wind-driven outflow with moderate electron fraction (Ye ≈ 0.27). Combined with the x-ray limits, we favor an observer viewing angle of ≈30° away from the orbital rotation axis, which avoids both obscuration from the heaviest elements in the orbital plane and a direct view of any ultrarelativistic, highly collimated ejecta (a γ-ray burst afterglow).

GRB 130427A: a nearby ordinary monster.

Long-duration gamma-ray bursts (GRBs) are an extremely rare outcome of the collapse of massive stars and are typically found in the distant universe. Because of its intrinsic luminosity (L ~ 3 × 10(53) ergs per second) and its relative proximity (z = 0.34), GRB 130427A reached the highest fluence observed in the γ-ray band. Here, we present a comprehensive multiwavelength view of GRB 130427A with Swift, the 2-meter Liverpool and Faulkes telescopes, and by other ground-based facilities, highlighting the evolution of the burst emission from the prompt to the afterglow phase. The properties of GRB 130427A are similar to those of the most luminous, high-redshift GRBs, suggesting that a common central engine is responsible for producing GRBs in both the contemporary and the early universe and over the full range of GRB isotropic energies.

Impact of acetaldehyde- and pyruvic acid-bound sulphur dioxide on wine lactic acid bacteria.

AIMS: To investigate the impact of acetaldehyde- and pyruvic acid-bound sulphur dioxide on wine lactic acid bacteria (LAB). METHODS AND RESULTS: Growth studies were performed where Oenococcus oeni, Pediococcus parvulus, Ped. damnosus and Lactobacillus hilgardii were inoculated into media containing various concentrations of acetaldehyde or pyruvic acid and an equimolar concentration of SO(2) at pH 3.50 and 3.70. Low concentrations of acetaldehyde- and pyruvic acid-bound SO(2) were inhibitory to the growth of all bacteria although acetaldehyde-bound SO(2) was generally more inhibitory than pyruvic acid-bound SO(2). Inhibition was greater at pH 3.50 than 3.70, and Lact. hilgardii was the most sensitive to acetaldehyde-bound SO(2), while O. oeni was the most sensitive to pyruvic acid-bound SO(2). Degradation of SO(2)-bound acetaldehyde was observed for all LAB, and aside from O. oeni, there was also complete degradation of SO(2)-bound pyruvic acid at both pH values. O. oeni only degraded pyruvic acid at pH 3.70. Degradation of SO(2)-bound acetaldehyde or pyruvic acid did not correlate with bacterial growth as inhibition was always observed in media containing bound SO(2). CONCLUSIONS: Acetaldehyde- and pyruvic acid-bound SO(2) were inhibitory to wine LAB growth at concentrations as low as 5 mg l(-1). Despite this inhibition, all wine LAB degraded SO(2)-bound acetaldehyde and pyruvic acid suggesting that bound SO(2) may have a bacteriostatic rather than bacteriocidal action. SIGNIFICANCE AND IMPACT OF THE STUDY: Sulphur dioxide bound to acetaldehyde or pyruvic acid is inhibitory to growth of wine LAB and must be considered when conducting the malolactic fermentation or controlling the growth of spoilage bacteria such as Pediococcus and Lactobacillus.

Relativistic jet activity from the tidal disruption of a star by a massive black hole.

Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.

Running an international paediatric non-commercial clinical trial.

The current regulations for conducting non-commercial clinical trials in Europe are many and complex. These are explored from the perspective of a UK based non-commercial international clinical trial. The reasons for the difficulties encountered are discussed and suggestions made as to how best to overcome them. Improvements are suggested for our law makers and competent authorities. It is argued that the current regulatory environment could be considered unethical as it inhibits and delays research.

Cerebral venous sinus thrombosis: a case series including thrombolysis.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) in children is associated with a high incidence of serious morbidity and mortality. The presenting features are variable. It can be diagnostically challenging and the optimal treatment is uncertain. AIM: To describe the features of a series of children with CVST treated in a single paediatric neurology centre and to discuss the role of local thrombolysis. METHODS: Electronic databases were searched using diagnostic labels and International Classification of Diseases (ICD) codes to identify children aged 1 month to under 17 years with CVST. Their records were reviewed. RESULTS: 21 children were identified over a period of 8.25 years with a median age of 7.1 years. The presenting symptoms included headache (15 children), vomiting (14 children) and visual disturbance (eight children). Signs found included papilloedema (16 children), fever (six children) and sixth nerve palsy (six children). The most common underlying condition was middle ear infection (13 children). All cases received unfractionated heparin and four severe cases received local pharmacological thrombolysis. 48% of cases had an adverse outcome (death, chronic intracranial hypertension, residual hemiparesis or sixth nerve palsy). DISCUSSION: CVST has non-specific presenting features and a high risk of significant morbidity. CVST is typically found in association with a predisposing condition. Although heparin is the mainstay of treatment, thrombolysis may reverse deterioration as seen in three cases in this series. However, there is insufficient evidence to recommend the routine use of thrombolysis at present.

Subependymal nodules, giant cell astrocytomas and the tuberous sclerosis complex: a population-based study.

OBJECTIVES: (1) In a population-based study of tuberous sclerosis (TSC), to identify the number of patients presenting with symptomatic giant cell astrocytomas (GCAs); (2) within a subset of this population, to identify the number who would be diagnosed with GCAs on predetermined radiological criteria. METHODS: Patients with TSC in Wessex (a geographical region of England) were identified, and their medical history determined. A subset were invited to have a cranial MRI if they did not have a history of a symptomatic GCA and if they were likely to tolerate cranial imaging without a general anaesthetic. Scans were performed according to a standard protocol on a single scanner and were reported blindly by a neuroradiologist. RESULTS: 179 people were identified with TSC. Ten of these had a history of treatment for a symptomatic GCA. Forty-one of the remainder had a cranial MRI. Thirty-nine of these had subependymal nodules, of whom 24 (59%) had at least one (maximum 11) that showed enhancement with gadolinium. In seven (17%), the lesion was >1 cm, and all of these lesions showed gadolinium enhancement. CONCLUSIONS: In this study, the proportion of patients with TSC who had a history of symptomatic GCA was 5.6%. In the subset without such a history, who underwent imaging, the number diagnosed as having a GCA on radiological criteria was much higher (59% gadolinium enhancement and 17% >1 cm in size). Screening for GCAs (performing scans on asymptomatic patients with TSC) would therefore identify large numbers of patients who had not presented with symptoms. This finding leads us to recommend that screening should not be undertaken.

X-ray flares in early GRB afterglows.

The Swift X-ray Telescope (XRT) has discovered that flares are quite common in early X-ray afterglows of gamma-ray bursts (GRBs), being observed in roughly 50% of afterglows with prompt follow-up observations. The flares range in fluence from a few per cent to approximately 100% of the fluence of the prompt emission (the GRB). Repetitive flares are seen, with more than four successive flares detected by the XRT in some afterglows. The rise and fall times of the flares are typically considerably smaller than the time since the burst. These characteristics suggest that the flares are related to the prompt emission mechanism, but at lower photon energies. We conclude that the most likely cause of these flares is late-time activity of the GRB central engine.

The association of GRB 060218 with a supernova and the evolution of the shock wave.

Although the link between long gamma-ray bursts (GRBs) and supernovae has been established, hitherto there have been no observations of the beginning of a supernova explosion and its intimate link to a GRB. In particular, we do not know how the jet that defines a gamma-ray burst emerges from the star's surface, nor how a GRB progenitor explodes. Here we report observations of the relatively nearby GRB 060218 (ref. 5) and its connection to supernova SN 2006aj (ref. 6). In addition to the classical non-thermal emission, GRB 060218 shows a thermal component in its X-ray spectrum, which cools and shifts into the optical/ultraviolet band as time passes. We interpret these features as arising from the break-out of a shock wave driven by a mildly relativistic shell into the dense wind surrounding the progenitor. We have caught a supernova in the act of exploding, directly observing the shock break-out, which indicates that the GRB progenitor was a Wolf-Rayet star.

Degradation of free and sulfur-dioxide-bound acetaldehyde by malolactic lactic acid bacteria in white wine.

AIMS: Acetaldehyde is the major carbonyl compound formed during winemaking and has implications for sensory and colour qualities of wines as well as for the use of the wine preservative SO(2). The current work investigated the degradation of acetaldehyde and SO(2)-bound acetaldehyde by two commercial Oenococcus oeni starters in white wine. METHODS AND RESULTS: Wines were produced by alcoholic fermentation with commercial yeast and adjusted to pH 3.3 and 3.6. While acetaldehyde was degraded rapidly and concurrently with malic acid at both pH values, SO(2)-bound acetaldehyde caused sluggish bacterial growth. Strain differences were small. CONCLUSIONS: Efficient degradation of acetaldehyde can be achieved by commercial starters of O. oeni. According to the results, the degradation of acetaldehyde could not be separated from malolactic conversion by oenococci. While this may be desirable in white winemaking, it may be necessary to delay malolactic fermentation (MLF) in order to allow for colour development in red wines. SO(2)-bound acetaldehyde itself maybe responsible for the sluggish or stuck MLF, and thus bound SO(2) should be considered next to free SO(2) in order to evaluate malolactic fermentability. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study provides new results regarding the metabolism of acetaldehyde and SO(2)-bound acetaldehyde during the MLF in white wine. The information is of significance to the wine industry and may contribute to reducing the concentration of wine preservative SO(2).

Psychopathology in tuberous sclerosis: an overview and findings in a population-based sample of adults with tuberous sclerosis.

BACKGROUND: Tuberous sclerosis (TS) is a multi- system disorder with complex genetics. The neurodevelopmental manifestations of TS are responsible for considerable morbidity. The prevalence of epilepsy and intellectual disabilities among individuals with TS have been well described. Ours is the first study that explores the prevalence and pattern of psychopathology in a population-based sample of adults with TS. METHODS: Sixty subjects were identified through a capture-recapture analysis of TS. Information was gathered as to seizure history, cognitive functioning (WISC-III) and psychopathology (SADS-L, SAPPA). Lifetime psychopathology was categorized according to Research Diagnostic Criteria. The overall pattern of mental illness (MI) was examined as well as how this varied with IQ and seizure history. RESULTS: Twenty-four (40.0%) subjects had a history of MI. The most common diagnosis was that of an affective disorder [18 (30.0%)], the majority of which were major depressive episodes. Alcoholism [4 (6.7%)] and anxiety disorders [3 (5.0%)] were the next most common diagnoses. Two (3.3%) subjects had had a tic disorder. Only one individual had a diagnosis of schizophrenia. MI was found in 75.0% of those with a history of epilepsy and 37.5% of those without epilepsy. MI was significantly more prevalent in those with a full-scale IQ above 70. CONCLUSIONS: A significant proportion of adult with TS experience MI. MI was significantly more [corrected] prevalent in subjects with a full-scale IQ above 70. Reasons for such a finding are explored, and related methodological considerations for future research outlined.

Gamma-ray bursts: huge explosion in the early Universe.

Long gamma-ray bursts (GRBs) are bright flashes of high-energy photons that can last for tens of minutes; they are generally associated with galaxies that have a high rate of star formation and probably arise from the collapsing cores of massive stars, which produce highly relativistic jets (collapsar model). Here we describe gamma- and X-ray observations of the most distant GRB ever observed (GRB 050904): its redshift (z) of 6.29 means that this explosion happened 12.8 billion years ago, corresponding to a time when the Universe was just 890 million years old, close to the reionization era. This means that not only did stars form in this short period of time after the Big Bang, but also that enough time had elapsed for them to evolve and collapse into black holes.

An unexpectedly rapid decline in the X-ray afterglow emission of long gamma-ray bursts.

'Long' gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which give rise to highly relativistic jets. Inhomogeneities in the expanding flow result in internal shock waves that are believed to produce the gamma-rays we see. As the jet travels further outward into the surrounding circumstellar medium, 'external' shocks create the afterglow emission seen in the X-ray, optical and radio bands. Here we report observations of the early phases of the X-ray emission of five GRBs. Their X-ray light curves are characterised by a surprisingly rapid fall-off for the first few hundred seconds, followed by a less rapid decline lasting several hours. This steep decline, together with detailed spectral properties of two particular bursts, shows that violent shock interactions take place in the early jet outflows.

Bright x-ray flares in gamma-ray burst afterglows.

Gamma-ray burst (GRB) afterglows have provided important clues to the nature of these massive explosive events, providing direct information on the nearby environment and indirect information on the central engine that powers the burst. We report the discovery of two bright x-ray flares in GRB afterglows, including a giant flare comparable in total energy to the burst itself, each peaking minutes after the burst. These strong, rapid x-ray flares imply that the central engines of the bursts have long periods of activity, with strong internal shocks continuing for hundreds of seconds after the gamma-ray emission has ended.

The relation of infantile spasms, tubers, and intelligence in tuberous sclerosis complex.

BACKGROUND: The aetiology of the learning difficulty in tuberous sclerosis is debated. It may be related to the amount of tubers in the brain or caused by the infantile spasms that occur in early life. AIMS: To examine the relative contributions to final intelligence (IQ) made by both cerebral tubers and infantile spasms. METHODS: As part of an epidemiological study of tuberous sclerosis in the south of England, patients were recruited who were able to undergo magnetic resonance imaging (MRI) without the need for an anaesthetic. Epilepsy history was determined by interview and review of clinical records. IQ was assessed using either Wechsler intelligence scales or Raven's matrices. RESULTS: A total of 41 patients consented to have an MRI scan. IQ scores were normally distributed about a mean of 91. Twenty six patients had a positive history of epilepsy, and 11 had suffered from infantile spasms. There was a significant relation between the number of tubers and IQ. Infantile spasm status partly confounded the relation between tubers and IQ, but did not render the relation statistically insignificant. The relation between infantile spasms and learning difficulty remained strong even when controlling for the number of tubers.

Learning disability and epilepsy in an epidemiological sample of individuals with tuberous sclerosis complex.

BACKGROUND: Intellectual impairments are a recognized feature of tuberous sclerosis complex (TSC), but the frequency and degree of intellectual impairments has not been systematically studied in large epidemiological samples using standardized measures. As such, the form of the IQ distribution (uni- or bi-modal) has not been established and the relationship between IQ and other features (e.g. epilepsy history) is poorly delineated. To address these shortcomings, we assessed the intellectual abilities of a large epidemiological sample of individuals with TSC, drawn from the 'Wessex' area of SW England and compared them with the abilities of their unaffected siblings. METHOD: Standardized tests were used to estimate the abilities of 108 (56 males, 52 females, median age = 25, range = 4-75) individuals with TSC and 29 unaffected siblings (14 males, 15 females, median age = 18, range = 6-55). Seizure history was obtained from informants and medical records. RESULTS: Estimated IQ was bi-modally distributed: 55.5% had an IQ in the normal range; 14% had mild to severe impairments: and 30.5% had profound disability (IQ < 21). Forty-four per cent of the individuals with TSC had an IQ < 70. In the subset of normally intelligent individuals with TSC, IQ was normally distributed with a mean of 93.6. This mean was significantly lower than the mean IQ of unaffected siblings (IQ = 105.6). All individuals with learning disability had a history of seizures that usually commenced before 12 months of age and that often presented as infantile spasms. Multivariate analyses indicated that a history of seizures as well as a history of infantile spasms was predictive of the degree of intellectual impairment. CONCLUSIONS: Intellectual abilities were bi-modally distributed in a representative sample of individuals with TSC. The likelihood of impairment was associated with a history of seizures, particularly infantile spasms. The genetic and brain basis of these findings requires further investigation.