We report on the temporal and spectral characteristics of the early X-ray emission from the Gamma Ray Bursts GRB050126 and GRB050219A as observed by Swift . The X-ray light-curves of these 2 bursts ...both show remarkably steep early decays ($F(t)\propto t^{-3}$), breaking to flatter slopes on timescales of a few hundred seconds. For GRB050126 the burst shows no evidence of spectral evolution in the 20–150 keV band, and the spectral index of the γ-ray and X-ray afterglows are significantly different suggesting a separate origin. By contrast the BAT spectrum of GRB050219A displays significant spectral evolution, becoming softer at later times, with Γ evolving toward the XRT photon index seen in the early X-ray afterglow phase. For both bursts, the 0.2–10 keV spectral index pre- and post-break in the X-ray decay light-curve are consistent with no spectral evolution. We suggest that the steep early decline in the X-ray decay light-curve is either the curvature tail of the prompt emission; X-ray flaring activity; or external forward shock emission from a jet with high density regions of small angular size (${>}\Gamma^{-1}$). The late slope we associate with the forward external shock.
Context.
The upcoming new generation of optical spectrographs on four-meter-class telescopes will provide valuable opportunities for forthcoming galaxy surveys through their huge multiplexing ...capabilities, excellent spectral resolution, and unprecedented wavelength coverage.
Aims.
WEAVE is a new wide-field spectroscopic facility mounted on the 4.2 m
William Herschel
Telescope in La Palma. WEAVE-StePS is one of the five extragalactic surveys that will use WEAVE during its first five years of operations. It will observe galaxies using WEAVE MOS (∼950 fibres distributed across a field of view of ∼3 square degrees on the sky) in low-resolution mode (
R
∼ 5000, spanning the wavelength range 3660 − 9590 Å).
Methods.
WEAVE-StePS will obtain high-quality spectra (
S
/
N
∼ 10 Å
−1
at
R
∼ 5000) for a magnitude-limited (
I
AB
= 20.5) sample of ∼25 000 galaxies, the majority selected at
z
≥ 0.3. The survey goal is to provide precise spectral measurements in the crucial interval that bridges the gap between LEGA-C and SDSS data. The wide area coverage of ∼25 square degrees will enable us to observe galaxies in a variety of environments. The ancillary data available in each of the observed fields (including X-ray coverage, multi-narrow-band photometry and spectroscopic redshift information) will provide an environmental characterisation for each observed galaxy.
Results.
This paper presents the science case of WEAVE-StePS, the fields to be observed, the parent catalogues used to define the target sample, and the observing strategy that was chosen after a forecast of the expected performance of the instrument for our typical targets.
Conclusions.
WEAVE-StePS will go back further in cosmic time than SDSS, extending its reach to encompass more than ∼6 Gyr. This is nearly half of the age of the Universe. The spectral and redshift range covered by WEAVE-StePS will open a new observational window by continuously tracing the evolutionary path of galaxies in the largely unexplored intermediate-redshift range.
OBJECTIVE: The aim of this study was to evaluate the characteristics of pain and its impact on upper limb functioning in patients with trapeziometacarpal osteoarthritis (TMC OA) and their ...relationship with site-specific radiological findings. PATIENTS AND METHODS: We performed a retrospective observational study including patients affected by TMC OA, according to the European League Against Rheumatism (EULAR) recommendations and graded with Eaton-Glickel classification. We excluded men and women under 50 years, patients with other hand disorders, and hand injuries in the last 24 months and previous hand surgery. Strength, pain, and disability of the upper limb were assessed in all patients with handheld Jamar dynamometer, Numeric Rating Scale (NRS) and disability by the Quick DASH (Disabilities of the Arm, Shoulder and Hand) scale, respectively. We divided our cohort in two groups according to Eaton-Glickel classification. First group included stage 1 and 2, whereas the second group included 3 and 4 stage. RESULTS: Our results demonstrated that patients with TMC OA have a significant reduction of strength and function of upper limb, and moderate-severe pain. However, the comparison according to all the outcome measures did not demonstrate significant difference between groups. CONCLUSIONS: Our findings demonstrated that the severity of radiological stage assessed with Eaton-Glickel classification is not correlated with the magnitude of symptoms, especially pain and upper limb function.
Forty-two samples of preharvest maize ear rot, collected in 1992-1993 from different maize fields throughout Italy, were examined for the relative incidence of Fusarium proliferatum and its ...toxigenicity. F. proliferatum (34%), together with F. moniliforme (54%), were the predominant species in infected ear kernels. Less frequently isolated were F equiseti (8%) and F. graminearum (2%), and to a much lesser extent, F chlamydosporum, F culmorum, F. oxysporum, F. semitectum, F. solani, F sporotrichioides, and F. subglutinans. When cultured on autoclaved maize kernels for 4 wk in the dark at 25 C, mycotoxin production by strains of F proliferarum was as follows: all of the 26 assayed strains ( 100%) produced fumonisin Bl (up to 2,250 mg/kg); 22 strains (85%) also produced beauvericin (up to 200 mg/kg); and 12 (46%) produced fumonisin B1, beauvericin, and moniliformin (up to 5,300 mg/kg). Cultural extracts of almost all F proliferatum strains revealed a high level of toxicity towards Artemia salina larvae. Selected infected maize ears, mostly colonized by F. proliferatum, were found to be contaminated by fumonisin Bl (up to 250 mg/ kg), beauvericin (up to 40 mg/kg), and moniliformin (200 mg/ kg). This is the first investigation of the relative incidence of toxigenic F. proliferatum strains as causal agents of maize ear rot, as well as of the natural occurrence of mycotoxins in preharvest F. proliferatum-colonized maize ears. The results strongly suggest a more significant role of F proliferatum in maize ear rot and in the associated mycotoxicoses. Moreover, these results show that a potential exists for the production of beauvericin, fumonisin Bl, and moniliformin in maize grown in Italy
Sphingosine kinase catalyzes the formation of sphingosine 1-phosphate, a lipid second messenger that has been implicated in a number of agonist-driven cellular responses including mitogenesis, ...anti-apoptosis, and expression of inflammatory molecules. Despite the importance of sphingosine kinase, very little is known regarding its structure or mechanism of catalysis. Moreover, sphingosine kinase does not contain recognizable catalytic or substrate-binding sites, based on sequence motifs found in other kinases. Here we have elucidated the nucleotide-binding site of human sphingosine kinase 1 (hSK1) through a combination of site-directed mutagenesis and affinity labeling with the ATP analogue, FSBA. We have shown that Gly82 of hSK1 is involved in ATP binding since mutation of this residue to alanine resulted in an enzyme with an ∼45-fold higher Km(ATP). We have also shown that Lys103 is important in catalysis since an alanine substitution of this residue ablates catalytic activity. Furthermore, we have shown that this residue is covalently modified by FSBA. Our data, combined with amino acid sequence comparison, suggest a motif of SGDGX17–21K is involved in nucleotide binding in the sphingosine kinases. This motif differs in primary sequence from all previously identified nucleotide-binding sites. It does, however, share some sequence and likely structural similarity with the highly conserved glycine-rich loop, which is known to be involved in anchoring and positioning the nucleotide in the catalytic site of many protein kinases.
We present observations of the X-ray afterglow of GRB 050408, a gamma-ray burst discovered by HETE-II. Swift began observing the field 42 min after the burst, performing follow-up over a period of ...38 d (thus spanning three decades in time). The X-ray light curve showed a steepening with time, similar to many other afterglows. However, the steepening was unusually smooth, over the duration of the XRT observation, with no clear break time. The early decay was too flat to be described in terms of standard models. We therefore explore alternative explanations, such as the presence of a structured afterglow or of long-lasting energy injection into the fireball from the central GRB engine. The lack of a sharp break puts constraints on these two models. In the former case, it may indicate that the angular energy profile of the jet was not a simple power law, while in the second model it implies that injection did not stop abruptly. The late decay may be due either to a standard afterglow (that is with no energy injection), or to a jetted outflow still being refreshed. A significant amount of absorption was present in the X-ray spectrum, corresponding to a rest-frame hydrogen column density $N_{\rm H} = 1.2_{-0.3}^{+0.4} \times 10^{22}$ cm-2, indicative of a dense environment.
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