Sub-mm counterparts to Lyman-break galaxies

We summarize the main results from our SCUBA survey of Lyman-break galaxies (LBGs) at z~3. Analysis of our sample of LBGs reveals a mean flux of S850=0.6$\pm$0.2 mJy, while simple models of emission based on the UV properties predict a mean flux about twice as large. Known populations of LBGs are expected to contribute flux to the weak sub-mm source portion of the far-IR background, but are not likely to comprise the bright source (S850>5 mJy) end of the SCUBA-detected source count. The detection of the LBG, Westphal-MM8, at 1.9 mJy suggests that deeper observations of individual LBGs in our sample could uncover detections at similar levels, consistent with our UV-based predictions. By the same token, many sub-mm selected sources with S850<2 mJy could be LBGs. The data are also consistent with the FarIR/$\beta$ relation holding at z=3.Comment: 6 pages, 1 figure, contributed talk at UMass/INAOE Conference ``Deep Millimeter Surveys'

The CHESS spectral survey of star forming regions: Peering into the protostellar shock L1157-B1 - II. Shock dynamics

Context. The outflow driven by the low-mass class 0 protostar L1157 is the prototype of the so-called chemically active outflows. The bright bowshock B1 in the southern outflow lobe is a privileged testbed of magneto-hydrodynamical (MHD) shock models, for which dynamical and chemical processes are strongly interdependent. Aims. We present the first results of the unbiased spectral survey of the L1157-B1 bowshock, obtained in the framework of the key program “Chemical HErschel Surveys of star forming regions” (CHESS). The main aim is to trace the warm and chemically enriched gas and to infer the excitation conditions in the shock region. Methods. The CO 5-4 and o-H2_O 1_(10)–1_(01) lines have been detected at high-spectral resolution in the unbiased spectral survey of the HIFI-band 1b spectral window (555–636 GHz), presented by Codella et al. in this volume. Complementary ground-based observations in the submm window help establish the origin of the emission detected in the main-beam of HIFI and the physical conditions in the shock. Results. Both lines exhibit broad wings, which extend to velocities much higher than reported up to now. We find that the molecular emission arises from two regions with distinct physical conditions : an extended, warm (100 K), dense (3 × 10^5 cm^(-3)) component at low-velocity, which dominates the water line flux in Band 1; a secondary component in a small region of B1 (a few arcsec) associated with high-velocity, hot (>400 K) gas of moderate density ((1.0–3.0) × 10^4 cm^(-3)), which appears to dominate the flux of the water line at 179μm observed with PACS. The water abundance is enhanced by two orders of magnitude between the low- and the high-velocity component, from 8 × 10^(-7) up to 8 × 10^(-5). The properties of the high-velocity component agree well with the predictions of steady-state C-shock models

METABOLISM OF SKIN DERIVED PRECURSOR (SKP) CELLS IN STIRRED SUSPENSION BIOREACTORS

INTRODUCTION More than six million people suffer from burn injuries every year. These injuries can result in psychological trauma, disabilities and permanent disfigurement. A common treatment for burn victims is an autologous graft surgery in which skin is transplanted from a healthy part of the body to the injury site (i.e. split thickness skin graft). This graft, however, does not contain functional dermal tissue, hair follicles or glands, often causing graft contraction, chronic irritation, and unnatural in appearance. We have hypothesized that skin-derived precursor (SKP) cells, a multipotent dermal stem cell that resides within skin hair follicles, can be utilized in conjunction with split thickness skin grafts to improve their function and minimize irritation. SKPs have a high proliferative potential and need to be expanded in a well-controlled, standardized culture environment before they can be utilized in clinical treatments [1]. It is essential to optimize the expansion of SKP cells in order to generate a bioprocess capable of producing enough cells for a clinical setting. METHODS -qNUTR = ∆[NUTR]/Int(Xv)dtThe specific uptake and production rates were calculated for cells cultured in static T-Flask environments and stirred suspension bioreactors run at 40, 60, 80, and 100 rpm. Equation 1 was used to calculate specific rates (qNUTR). The integral change in viable cells (Int(Xv)dt) was calculated using a numerical trapezoid approximation, and the change in nutrient concentration (∆[NUTR]) was measured using the Nova Bioprofile 100+ analyzer. SKP cells were taken from a 68 year old female. RESULTS The specific uptake rates of glucose and glutamine and specific production rates of lactate and ammonia have been determined under altered cell culture environments for SKP cells (Figure1). This provides details into nutrient limitations and cell metabolic behaviours needed to access parameters to guide our bioprocess design and development of robust expansion protocols. DISCUSSION AND CONCLUSIONS Low levels of oxygen and nutrients result in significant changes to cell growth rates [2].  We were able to conclude that SKP cell growth is not limited by the glucose or glutamine concentrations in the media, and lactate and ammonia do not reach toxic levels. It is interesting to note that the stirred suspension environment does appear to have an effect on the specific consumption rates of glucose and glutamine. According to these initial results, we are predicting that under shear stress environments, SKP cells are changing their metabolic behaviour to allow more glucose to convert to pyruvate and enter the TCA cycle. The specific production rates of lactate and ammonia, however, do not follow the same patterns. Further validation and reasons behind these differences need to be investigated

Further multiwavelength observations of the SSA22 Ly_alpha emitting `blob'

We present new follow-up observations of the sub-mm luminous Ly_alpha-emitting object in the SSA22 z=3.09 galaxy overdensity, referred to as `Blob 1' by Steidel et al.(2000). In particular we discuss high resolution Hubble Space Telescope optical imaging, Owens Valley Radio Observatory spectral imaging, Keck spectroscopy, VLA 20cm radio continuum imaging, and Chandra X-ray observations. We also present a more complete analysis of the existing James Clerk Maxwell Telescope sub-mm data. We detect several optical continuum components which may be associated with the core of the submillimeter emitting region. A radio source at the position of one of the HST components (22:17:25.94, +00:12:38.9) identifies it as the likely counterpart to the submillimeter source. We also tentatively detect the CO(4-3) molecular line, centered on the radio position. We use the CO(4-3) intensity to estimate a limit on the gas mass for the system. The optical morphology of sources within the Ly_alpha cloud appears to be filamentary, while the optical source identified with the radio source has a dense knot which may be an AGN or compact starburst. We obtain a Keck-LRIS spectrum of this object, despite its faintness (R=26.8). The spectrum reveals weak Ly_alpha emission, but no other obvious features, suggesting that the source is not an energetic AGN (or that it is extremely obscured). We use non-detections in deep Chandra X-ray images to constrain the nature of the `Blob'. Although conclusive evidence regarding the nature of the object remains hard to obtain at this redshift, the evidence presented here is at least consistent with a dust-obscured AGN surrounded by a starburst situated at the heart of this giant Ly_alpha cloud.Comment: 8 pages, 9figs (low res), to appear in ApJ, for higher res figures, http://www.submm.caltech.edu/~schapman/sa22_sept4.ps.g

Protocol development to overcome bioprocess bottlenecks in the large-scale expansion of high quality hIPSC aggregates in vertical-wheel bioreactors

Human-induced pluripotent stem cells (hiPSCs) have generated a great deal of attention owing to their capacity for self-renewal and trilineage differentiation. hiPSCs are cultured as adherent colonies at small scale, which is sufficient to generate cells for experimental purposes but impractical to achieve large quantities for clinical applications. Bioreactor-based processes are the method of choice for efficient expansion and differentiation of cells. Current protocols for the expansion of hiPSCs, however, utilize horizontal impeller, paddle, or rocking wave mixing method bioreactors which require large static cell-culture starting populations and achieve only moderate cell fold increases within the bioreactor. We have recently demonstrated that the vertical-wheel bioreactor produces a unique fluid flow pattern that results in a homogeneous distribution of hydrodynamic forces, making it the opportune environment for systematic bioprocess optimization of hiPSC expansion. Please click Additional Files below to see the full abstract

Incidence of tricyclic antidepressant-like complications after cyclobenzaprine overdose

Background: The cyclobenzaprine structure is similar to amitriptyline; however, tricyclic antidepressant (TCA)-like wide complex dysrhythmia has not been reported. Our objective was to determine the incidence of TCA-like effects in cyclobenzaprine overdoses as reported to 6 poison centers for 2 years. We compared the incidence of these effects to amitriptyline overdoses collected during the same period. Methods: We performed a retrospective review of 2 years of cases as reported to the Texas Poison Center Network. We identified sole ingestions of cyclobenzaprine and of amitriptyline. Cases had a recorded clinical outcome and clinical effect. A trained reviewer used a standard data collection sheet within a secured electronic database. One investigator audited a random sample of charts. Results: We identified 3974 cases of cyclobenzaprine calls. Of these, we collected 209 cases of acute overdoses without coingestions. There were no deaths. No cases of cyclobenzaprine ingestions were reported to have died or have a wide QRS or ventricular dysrhythmia. Seizures were reported in 2 cases; however, both were unrelated to cyclobenzaprine. Hypotension was reported in 1.4% (3/209) of cases, and a vasopressor was used in one case (0.5%). Patients with an amitriptyline overdose were more likely to have seizure, coma, tachycardia, a wide QRS or ventricular dysrhythmia, and have received sodium bicarbonate or be intubated. Conclusions: Cyclobenzaprine overdoses were not reported to cause widened QRS, ventricular dysrhythmias, or seizures, and hypotension was rarely reported. Tricyclic antidepressant-related effects occurred more often in our comparison group of amitriptyline overdoses

Data processing pipeline for Herschel HIFI

Context. The HIFI instrument on the Herschel Space Observatory performed over 9100 astronomical observations, almost 900 of which were calibration observations in the course of the nearly four-year Herschel mission. The data from each observation had to be converted from raw telemetry into calibrated products and were included in the Herschel Science Archive. Aims. The HIFI pipeline was designed to provide robust conversion from raw telemetry into calibrated data throughout all phases of the HIFI missions. Pre-launch laboratory testing was supported as were routine mission operations. Methods. A modular software design allowed components to be easily added, removed, amended and/or extended as the understanding of the HIFI data developed during and after mission operations. Results. The HIFI pipeline processed data from all HIFI observing modes within the Herschel automated processing environment as well as within an interactive environment. The same software can be used by the general astronomical community to reprocess any standard HIFI observation. The pipeline also recorded the consistency of processing results and provided automated quality reports. Many pipeline modules were in use since the HIFI pre-launch instrument level testing. Conclusions. Processing in steps facilitated data analysis to discover and address instrument artefacts and uncertainties. The availability of the same pipeline components from pre-launch throughout the mission made for well-understood, tested, and stable processing. A smooth transition from one phase to the next significantly enhanced processing reliability and robustness