Analysis of the Herschel/HEXOS Spectral Survey Towards Orion South: A massive protostellar envelope with strong external irradiation.

We present results from a comprehensive submillimeter spectral survey toward the source Orion South, based on data obtained with the HIFI instrument aboard the Herschel Space Observatory, covering the frequency range 480 to 1900 GHz. We detect 685 spectral lines with S/N > 3σ, originating from 52 different molecular and atomic species. We model each of the detected species assuming conditions of Local Thermodynamic Equilibrium. This analysis provides an estimate of the physical conditions of Orion South (column density, temperature, source size, & V LSR ). We find evidence for three different cloud components: a cool (T ex ~ 20 - 40 K), spatially extended (> 60″), and quiescent (ΔVFWHM ~ 4 km s -1) component; a warmer (T ex ~ 80 - 100 K), less spatially extended (~ 30″), and dynamic (ΔVFWHM ~ 8 km s -1) component, which is likely affected by embedded outflows; and a kinematically distinct region (T ex > 100 K; V LSR ~ 8 km s -1), dominated by emission from species which trace ultraviolet irradiation, likely at the surface of the cloud. We find little evidence for the existence of a chemically distinct "hot core" component, likely due to the small filling factor of the hot core or hot cores within the Herschel beam. We find that the chemical composition of the gas in the cooler, quiescent component of Orion South more closely resembles that of the quiescent ridge in Orion-KL. The gas in the warmer, dynamic component, however, more closely resembles that of the Compact Ridge and Plateau regions of Orion-KL, suggesting that higher temperatures and shocks also have an influence on the overall chemistry of Orion South.

Deuterium enhancement in H3+ in pre-stellar cores.

Deuterium enhancement of monodeuterated species has been recognized for more than 30 years as a result of chemical fractionation that results from the difference in zero-point energies of deuterated and hydrogenated molecules. The key reaction is the deuteron exchange in the reaction between HD, the reservoir of deuterium in dark interstellar clouds, and the H3+ molecular ion, leading to the production of H2D+ molecule, and the low temperature in dark interstellar clouds favours this production. Furthermore, the presence of multiply deuterated species have incited our group to proceed further and consider the subsequent reaction of H2D+ with HD, leading to D2H+, which can further react with HD to produce D3+. In pre-stellar cores, where CO was found to be depleted, this production should be increased as CO would normally destroy H3+. The first model including D2H+ and D3+ predicted that these molecules should be as abundant as H2D+. The first detection of the D2H+ was made possible by the recent laboratory measurement for the frequency of the fundamental line of para-D2H+. Here, we present observations of H2D+ and D2H+ towards a sample of dark clouds and pre-stellar cores and show how the distribution of ortho-H2D+ (1(1,0)-1(1,1)) can trace the deuterium factory in pre-stellar cores. We also present how future instrumentation will improve our knowledge concerning the deuterium enhancement of H3+.

Albumin in the pump prime: its effect on postoperative weight gain.

An investigation was conducted to determine whether adding albumin to the prime of the cardiopulmonary bypass circuit had any effect on postoperative weight gain. Patients undergoing non-emergency myocardial revascularization for coronary artery disease were divided into two groups. Group I (albumin) received 250 ml of 5% human albumin in their pump prime, whereas group II (control) served as controls. The same surgeon, anesthesia technique, perfusion circuit and conduct, and postoperative management were employed for all patients in the study. No statistically significant differences could be found between the groups for any of the variables studied, including fluid intake during surgery and the first 24 h postoperation, urine output, fluid balance and postoperative weight gain. The authors conclude from this investigation that adding 250 ml of 5% human albumin to the pump prime has no effect on postoperative weight gain. The next step could be to examine the effect of using larger amounts of albumin or plasma volume expanders in the pump prime.

Topical therapies for glaucoma: what family physicians need to know.

Medication classes historically used in the management of glaucoma include beta blockers, miotics, sympathomimetics and carbonic anhydrase inhibitors. Because topically applied medications are more site specific, they are preferred in the treatment of glaucoma. Compared with oral medications, topical agents are associated with a decreased incidence of systemic side effects. With topical administration, conjunctival and localized skin allergic reactions are relatively common, whereas severe reactions, including death, are rare. Recently introduced topical agents for glaucoma therapy include dorzolamide and brinzolamide, the first topical carbonic anhydrase inhibitors; brimonidine and apraclonidine, more ocular-specific alpha agonists; and latanoprost, a prostaglandin analog, which is a new class of glaucoma medication. Latanoprost has the unique side effect of increasing iris pigmentation. Like their predecessors, the newer agents lower intraocular pressure by a statistically significant degree. Preservation of visual field, the more substantial patient-oriented end point, continues to be studied.

A line survey of Orion KL from 325 to 360 GHz.

We present a high-sensitivity spectral line survey of the high-mass star-forming region Orion KL in the 325-360 GHz frequency band. The survey was conducted at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. The sensitivity achieved is typically 0.1-0.5 K and is limited mostly by the sideband separation method utilized. We find 717 resolvable features consisting of 1004 lines, among which 60 are unidentified. The identified lines are due to 34 species and various isotopomers. Most of the unidentified lines are weak, and many of them most likely due to isotopomers or vibrationally or torsionally excited states of known species with unknown line frequencies, but a few reach the 2-5 K level. No new species have been identified, but we were able to strengthen evidence for the identification of ethanol in Orion and found the first nitrogen sulfide line in this source. The molecule dominating the integrated line emission is S02, which emits twice the intensity of CO, followed by SO, which is only slightly stronger than CO. In contrast, the largest number of lines is emitted from heavy organic rotors like HCOOCH3, CH3CH2CN, and CH3OCH3, but their contribution to the total flux is unimportant. CH3OH is also very prominent, both in the number of lines and in integrated flux. An interesting detail of this survey is the first detection of vibrationally excited HCN in the v2 = 2 state, 2000 K above ground. Clearly this is a glimpse into the very inner part of the Orion hot core.

Spectroscopic evidence for interstellar ices in comet Hyakutake.

Volatile compounds in comets are the most pristine materials surviving from the time of formation of the Solar System, and thus potentially provide information about conditions that prevailed in the primitive solar nebula. Moreover, comets may have supplied a substantial fraction of the volatiles on the terrestrial planets, perhaps including organic compounds that played a role in the origin of life on Earth. Here we report the detection of hydrogen isocyanide (HNC) in comet Hyakutake. The abundance of HNC relative to hydrogen cyanide (HCN) is very similar to that observed in quiescent interstellar molecular clouds, and quite different from the equilibrium ratio expected in the outermost solar nebula, where comets are thought to form. Such a departure from equilibrium has long been considered a hallmark of gas-phase chemical processing in the interstellar medium, suggesting that interstellar gases have been incorporated into the comet's nucleus, perhaps as ices frozen onto interstellar grains. If this interpretation is correct, our results should provide constraints on the temperature of the solar nebula, and the subsequent chemical processes that occurred in the region where comets formed.

Characterization of a submillimeter high-angular-resolution camera with a monolithic silicon bolometer array for the Caltech Submillimeter Observatory.

We constructed a 24-pixel bolometer camera operating in the 350- and 450-µm atmospheric windows for the Caltech Submillimeter Observatory (CSO). This instrument uses a monolithic silicon bolometer array that is cooled to approximately 300 mK by a single-shot (3)He refrigerator. First-stage amplification is provided by field-effect transistors at approximately 130 K. The sky is imaged onto the bolometer array by means of several mirrors outside the Dewar and a cold off-axis elliptical mirror inside the cryostat. The beam is defined by cold aperture and field stops, which eliminates the need for any condensing horns. We describe the instrument, present measurements of the physical properties of the bolometer array, describe the performance of the electronics and the data-acquisition system, and demonstrate the sensitivity of the instrument operating at the observatory. Approximate detector noise at 350 µm is 5 × 10(-15) W/√Hz, referenced to the entrance of the Dewar, and the CSO system noise-equivalent flux density is approximately 4 Jy/√Hz. These values are within a factor of 2.5 of the background limit.

The molecular emission-line spectrum of IRC +10216 between 330 and 358 GHz.

We have conducted a spectral line survey of IRC +10216 using the Caltech Submillimeter Observatory to an average sensitivity of < or approximately 95 mK. A deconvolution algorithm has been used to derive the continuous single-sideband spectrum from 330.2 to 358.1 GHz. A total of 56 spectral lines were detected of which 54 have been identified with 8 molecules and a total of 18 isotopomers. The observed lines are used to derive column densities and relative abundances for the detected species. Within this frequency range the spectral lines detected contribute the majority of the total flux emitted by IRC +10216. We use the derived column densities and excitation temperatures to simulate the molecular line emission (assuming LTE) at frequencies up to 1000 GHz. The observed and simulated flux from line emission is compared to broadband total flux measurements and to dust emission assuming a power-law variation of the dust emissivity. We conclude that significant corrections for the line flux must be made to broadband flux measurements of IRC +10216 at wavelengths longer than approximately 750 micrometers.

Use of cardioplegia delivery equipment for rapid warm volume replacement after cardiopulmonary bypass.

Often, after cardiopulmonary bypass involving aortic dissection, aortic root replacements, or valve conduits, rapid volume replacement with blood products is essential to obtain hemostasis and patient survival. We describe a method of using cardiopulmonary bypass equipment for rapid warm volume replacement and infusion of remaining residual volume in the cardiopulmonary bypass circuit after a cardiac operation.

Surface figure measurements of radio telescopes with a shearing interferometer.

A new technique for determining the surface figure of large submillimeter wavelength telescopes is presented, which is based on measuring the telescope's focal plane diffraction pattern with a shearing interferometer. In addition to the instrumental theory, results obtained using such an interferometer on the 10.4-m diam telescope of the Caltech Submillimeter Observatory are discussed. Using wavelengths near 1 mm, a measurement accuracy of 9 microm, or lambda/115, has been achieved, and the rms surface accuracy has been determined to be just under 30 microm. The distortions of the primary reflector with changing elevation angle have also been measured and agree well with theoretical predictions of the dish deformation.

Left recurrent laryngeal nerve injury following internal mammary artery bypass.

To our knowledge, recurrent laryngeal nerve injury has not been reported previously as a complication of internal mammary artery mobilization for coronary artery bypass. We recently experienced this complication and are presenting a case history of the problem and comments.