We have observed the host galaxy of the low-redshift, low-luminosity Swift GRB 080517 at 105.8 GHz using the IRAM Plateau de Bure interferometer. We detect an emission line with integrated flux ...SDeltanu = 0.39 + or - 0.05 Jy km s super(-1)-consistent both spatially and in velocity with identification as the J= 1-0 rotational transition of carbon monoxide (CO) at the host galaxy redshift. This represents only the third long gamma-ray burst (GRB) host galaxy with molecular gas detected in emission. The inferred molecular gas mass, super(M) sub(H2)~ 6.3 x 10 super(8)M sub(middot in circle), implies a gas consumption timescale of ~40 Myr if star formation continues at its current rate. Similar short timescales appear characteristic of the long GRB population with CO observations to date, suggesting that the GRB in these sources occurs toward the end of their star formation episode.
We determine the space density of UV-luminous starburst galaxies at z≈ 6 using deep HST ACS SDSS-i′ (F775W) and SDSS-z′ (F850LP) and VLT ISAAC J and Ks band imaging of the Chandra Deep Field South. ...We find eight galaxies and one star with (i′−z′) > 1.5 to a depth of z′AB= 25.6 (an 8σ detection in each of the 3 available ACS epochs). This corresponds to an unobscured star formation rate of ≈15 h−270 M⊙ yr−1 at z= 5.9, equivalent to L* for the Lyman-break population at z= 3–4 (ΩΛ= 0.7, ΩM= 0.3). We are sensitive to star-forming galaxies at 5.6 ≲z≲ 7.0 with an effective comoving volume of ≈1.8 × 105h−370 Mpc3 after accounting for incompleteness at the higher redshifts due to luminosity bias. This volume should encompass the primeval subgalactic-scale fragments of the progenitors of about a thousand L* galaxies at the current epoch. We determine a volume-averaged global star formation rate of (6.7 ± 2.7) × 10−4h70 M⊙ yr−1 Mpc−3 at z∼ 6 from rest-frame UV selected starbursts at the bright end of the luminosity function: this is a lower limit because of dust obscuration and galaxies below our sensitivity limit. This measurement shows that at z∼ 6 the star formation density at the bright end is a factor of ∼6 times less than that determined by Steidel et al. for a comparable sample of UV-selected galaxies at z= 3–4, and so extends our knowledge of the star formation history of the Universe to earlier times than previous work and into the epoch where reionization may have occurred.
We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, ...respectively. The host remains undetected to 3sigma limits of F sub(v)(222GHz) lap mu Jy and F sub(v)(3.6 mu m) lap 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L sub(IR)(8-1000 mu m) lap 3 x 10 super(10) L sub(middot in circle), corresponding to a limit on the obscured star formation rate of SFR sub(IR) lap 5 M sub(middot in circle) yr super(-1). For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFR sub(UV) lap 1 M sub(middot in circle) yr super(-1). We also place a limit on the host galaxy stellar mass of M sub(*) lap 5 x 10 super(7) M sub(middot in circle) (for a stellar population age of 100Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z gap 4 (Lyman break galaxies, Ly alpha emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z gap 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.
We present an analysis of the photometry and spectroscopy of the host galaxy of Swift-detected GRB 080517. From our optical spectroscopy, we identify a redshift of z = 0.089 plus or minus 0.003, ...based on strong emission lines, making this a rare example of a very local, low-luminosity, long gamma-ray burst. The galaxy is detected in the radio with a flux density of S(4.8 GHz) = 0.22 plus or minus 0.04 mJy -- one of relatively few known gamma-ray bursts hosts with a securely measured radio flux. Both optical emission lines and a strong detection at 22 mu m suggest that the host galaxy is forming stars rapidly, with an inferred star formation rate similar to 16 Msun/yr and a high dust obscuration (E(B - V) > 1, based on sightlines to the nebular emission regions). The presence of a companion galaxy within a projected distance of 25 kpc, and almost identical in redshift, suggests that star formation may have been triggered by galaxy-galaxy interaction. However, fitting of the remarkably flat spectral energy distribution from the ultraviolet through to the infrared suggests that an older, 500 Myr post-starburst stellar population is present along with the ongoing star formation. We conclude that the host galaxy of GRB 080517 is a valuable addition to the still very small sample of well-studied local gamma-ray burst hosts.
We have used the Large Apex Bolometer Camera Survey of the Extended Chandra Deep Field South to investigate rest-frame far-infrared (FIR) emission from typical star-forming systems (Lyman-break ...galaxies, LBGs, and Lyman α emitters, LAEs) at redshift 3, 4, 4.5 and 5 (922, 68, 46 and 20 sources, respectively). We initially concentrate on LBGs at z ∼ 3 and select three sub-samples on stellar mass (rest-frame optical brightest, M
* > 1010.25 M), extinction-corrected star formation (assuming βUV = −2 and applying a dust attenuation correction, SFRtot > 6.7 M yr−1) and rest-frame UV magnitude (representing a typical Lyman-break selection with R < 24.43). We produce composite 870 μm images of the typical source in our sub-samples, obtaining ∼4σ detections (0.61, 0.35 and 0.37 mJy, respectively) and suggesting a correlation between FIR luminosity and stellar mass. We apply a similar procedure to our full samples at z ∼ 3, 4, 4.5 and 5 and do not obtain detections - a result that is consistent with a simple scaling between FIR luminosity and stellar mass. In order to constrain the FIR spectral energy distribution (SED) of these systems, we explore their emission at multiple wavelengths spanning the peak of dust emission at z ∼ 3 using the Herschel Spectral and Photometric Imaging Receiver (SPIRE) observations of the field. We obtain detections at multiple wavelengths of both our stellar mass and UV-magnitude-selected samples, and find a best-fitting SED with dust temperatures in the ∼33-41 K range. We calculate FIR luminosity, obscured star formation rates (SFRs) and dust masses and find that a significant fraction of star formation in these systems is obscured. Interestingly, our sample selected on extinction-corrected SFR does not display the large FIR fluxes predicted from its red UV spectral slope. This suggests that the method of assuming an intrinsic UV slope and correcting for dust attenuation may be invalid for this sample - and that these are not in fact the most actively star-forming systems. All of our z ∼ 3 samples fall on the 'main sequence' of star-forming galaxies at z ∼ 3 and our detected sub-samples are likely to represent the high obscuration end of the LBGs population at their epoch. We compare the FIR properties of our sub-samples with various other galaxy populations, finding that our stellar mass selected sample shows some similar FIR characteristics to Submillimeter Galaxies (SMGs) at the same epoch and therefore potentially represents the low FIR luminosity end of the high-redshift FIR luminosity function.
Here we discuss proteomic analyses of whole cell preparations of the mosquito stages of malaria parasite development (i.e. gametocytes, microgamete, ookinete, oocyst and sporozoite) of Plasmodium ...berghei. We also include critiques of the proteomes of two cell fractions from the purified ookinete, namely the micronemes and cell surface. Whereas we summarise key biological interpretations of the data, we also try to identify key methodological constraints we have met, only some of which we were able to resolve. Recognising the need to translate the potential of current genome sequencing into functional understanding, we report our efforts to develop more powerful combinations of methods for the in silico prediction of protein function and location. We have applied this analysis to the proteome of the male gamete, a cell whose very simple structural organisation facilitated interpretation of data. Some of the in silico predictions made have now been supported by ongoing protein tagging and genetic knockout studies. We hope this discussion may assist future studies.
The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z>5) is small (∼15); however, these events provide a powerful way of probing star formation at the onset of ...galaxy evolution. In this paper, we present the case for GRB100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its host galaxy have not been explored in detail. By combining optical and near-infrared Gemini afterglow imaging (at t < 1.3 d since burst) with deep late-time limits on host emission from the Hubble Space Telescope, we show that the most likely scenario is that GRB100205A arose in the range 4 < z<8. GRB100205A is an example of a burst whose afterglow, even at ∼1 h post burst, could only be identified by 8-m class IR observations, and suggests that such observations of all optically dark bursts may be necessary to significantly enhance the number of high-redshift GRBs known.
Single arm phase 1 and 2 studies on Crizotinib in ALK-positive patients so far have shown rapid and durable responses. Spontaneous pneumothoraces as a result of response to anti-cancer therapy are ...rare in oncology but have been documented in a number of tumour types including lung cancer. This includes cytotoxic chemotherapy as well as molecular targeted agents such as gefitinib and Bevacizumab. These often require chest drain insertion or surgical intervention with associated morbidity and mortality. They have also been associated with response to treatment. This is the first report we are aware of documenting pneumothorax as response to crizotinib therapy.
A 48-year-old Caucasian male presented with a Stage IV, TTF1 positive, EGFR wild-type adenocarcinoma of the lung. He received first line chemotherapy with three cycles of cisplatin-pemetrexed chemotherapy with a differential response, and then second-line erlotinib for two months before further radiological evidence of disease progression. Further analysis of his diagnostic specimen identified an ALK rearrangement by fluorescence in situ hybridization (FISH). He was commenced on crizotinib therapy 250 mg orally twice daily. At his 4-week assessment he had a chest radiograph that identified a large left-sided pneumothorax with disease response evident on the right. Chest CT confirmed a 50% left-sided pneumothorax on a background of overall disease response. A chest tube was inserted with complete resolution of the pneumothorax that did not recur following its removal.
Our case demonstrates this potential complication of crizotinib therapy and we therefore recommend that pneumothorax be considered in patients on crizotinib presenting with high lung metastatic burden and with worsening dyspnoea.
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