The Intermediate Line Region and the Baldwin Effect

Statistical investigations of samples of quasars have established that clusters of properties are correlated. The strongest trends among the ultraviolet emission-line properties are characterized by the object-to-object variation of emission from low-velocity gas, the so-called ``intermediate-line region'' or ILR. The strongest trends among the optical emission-line properties are characterized by the object-to-object variation of the line intensity ratio of [O III] 5007 to optical Fe II. Additionally, the strength of ILR emission correlates with [O III]/Fe II, as well as with radio and X-ray properties. The fundamental physical parameter driving these related correlations is not yet identified. Because the variation in the ILR dominates the variation in the equivalent widths of lines showing the Baldwin effect, it is important to understand whether the physical parameter underlying this variation also drives the Baldwin effect or is a primary source of scatter in the Baldwin effect.Comment: 11 pages, to appear in the proceedings of the meeting on "Quasars as Standard Candles for Cosmology" held on May 18-22, 1998, at La Serena, Chile. To be published by ASP, editor G. Ferlan

Challenges and Solutions for Functional Neurosurgery in Developing Countries.

Functional neurosurgery techniques remain integral to the neurosurgical treatment armamentarium but data on global implementation remains scarce. In comparison to high-income countries (HIC), low- and middle-income countries (LMIC) suffer from an increased prevalence of diseases like epilepsy, which may be amenable to functional techniques, and therefore, LMIC may benefit from an increased utilization of these treatment modalities. However, functional techniques tend to be expensive and thus difficult to implement in the LMIC setting. A review was performed to assess the current status of functional neurosurgical techniques in LMIC as a starting point for future initiatives. For methodology, a review of the current body of literature on functional neurosurgery in LMIC was conducted through the United States National Library of Medicine Pubmed search engine. Search terms included "functional neurosurgery," "developing countries," "low and middle income," and other related terms. It was found that though five billion people lack access to safe surgical care, the burden of disease amenable to treatment with functional neurosurgical procedures remains unknown. Increasingly, reports of successful, long-term, international neurosurgical collaborations are being reported, but reports in the sub-field of functional neurosurgery are lacking. In conclusion, awareness of global surgical disparities has increased dramatically while global guidelines for functional techniques are currently lacking. A concerted effort can harness these techniques for wider practice. Partnerships between centers in LMIC and HIC are making progress to better understand the burden of disease in LMIC and to create context-specific solutions for practice in the LMIC setting, but more collaborations are warranted

An Unbiassed Census of Active Galactic Nuclei in the Two Micron All Sky Survey

(Abridged) We present an unbiassed near-IR selected AGN sample, covering 12.56 square degrees down to K ~ 15.5, selected from the Two Micron All Sky Survey (2MASS). Our only selection effect is a moderate color cut (J-K>1.2) designed to reduce contamination from galactic stars. We observed both point-like and extended sources. Using the brute-force capabilities of the 2dF multi-fiber spectrograph on the Anglo-Australian Telescope, we obtained spectra of 65% of the target list: an unbiassed sub-sample of 1526 sources. 80% of the 2MASS sources in our fields are galaxies, with a median redshift of 0.15. The remainder are K- and M-dwarf stars. Seyfert-2 Galaxies are roughly three times more common in this sample than in optically selected galaxy samples (once corrections have been made for the equivalent width limit and for different aperture sizes). We find 14 broad-line (Type-1) AGNs, giving a surface density down to K<15 comparable to that of optical samples down to B=18.5. Half of our Type-1 AGNs could not have been found by normal color selection techniques. In all cases this was due host galaxy light contamination rather than intrinsically red colors. We conclude that the Type-1 AGN population found in the near-IR is not dramatically different from that found in optical samples. There is no evidence for a large population of AGNs that could not be found at optical wavelengths, though we can only place very weak constraints on any population of dusty high-redshift QSOs.Comment: AJ in pres

Endoscopic Management of an Internal Laryngopyocele Presenting with Acute Airway Obstruction

Statement of Problem. Laryngocele is a rare laryngeal disease, where there is an abnormal dilatation of the saccule of the laryngeal ventricle. It can either be internal or external, and a laryngopyocele is a rare complication of this anomaly. Internal laryngopyoceles can prove difficult to manage, as they often present with airway compromise. Method of Study. Case Report. Results. We present a case of a laryngopyocele that was successfully managed with suspension laryngoscopy and endoscopic marsupialisation and resection. To our knowledge, this is the first such case described in the literature. Conclusions. Surgical drainage of a laryngopyocele via the external approach is well documented in the literature. We feel that endoscopic resection of laryngopyoceles in an emergency situation is a viable alternative and also prevents the associated surgical morbidity

Microfluidic devices for cell cultivation and proliferation

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined

Confirmation of the classic tris(2,2̒-bipyridyl)ruthenium(II) and oxalate electrochemiluminescence mechanism using EPR spectroscopy

A chemically initiated adaptation of the classic [Ru(bipy) ]/oxalate electrochemiluminescence coreactant system has revealed the elusive radical intermediates of the light-producing pathway. Oxalyl (HCO) and hydroxyformyl (HCO) radicals have been captured on a quartz surface and characterised using EPR spectroscopy

997-90 Right (RV) and Left Ventricular (LV) Geometry and Myocyte Contractile Processes with Dilated Cardiomyopathy (DCM): Disparity Between Myocyte Growth and β-Adrenergic Responsiveness

The progression of DCM has been assumed to be a homogenous process for both the RV and LV. However, this assumption has never been tested. Accordingly, we measured myocyte contractile performance (velocity of shortening, VELSHORT; percent shortening, PERSHORT) at baseline (BASE) and after β-adrenergic receptor stimulation (βAR, 25 nM isoproterenol) of isolated myocytes taken from the RV and LV of 5 pigs with pacing induced DCM (240 bpm, 3 weeks) and 5 control pigs (CON). RV and LV mass/body weight (MASS) and myocyte length and cross-sectional area (CSA) were also determined.CON-RVCON-LVDCM-RVDCM-LVVELSHORT-BASE (μm/s)90±5+50±148±2*,+32±1*VELSHORT-βAR (μm/s)206±8+150±5123±8*111±9*PERSHORT-BASE (%)5.8±0.2+4.6±0.13.1±0.1*,+2.2±0.1*PERSHORT-βAR (%)11.5±0.3+10.2±0.359±0.3*5.2±0.4*Length (μm)150±2+137±1179±2*,+173±2*CSA (μm2)176±4+362±8232±4*,+292±5*Mass (gm/kg)0.8±0.1+2.8±0.11.6±0.1*,+2.9±0.2+p&lt;0.05 vs LV*p&lt;005 vS CONIn controls, RV myocytes were longer and had a smaller CSA, but enhanced contractile performance at baseline and with β-adrenergic stimulation. With DCM, no LV hypertrophy occurred. In contrast, RV chamber and cellular hypertrophy occurred and was associated with a persistent increase of RV myocyte baseline contractile function.SummaryThis study demonstrated, for the first time, that differences in RV and LV myocyte function and β-adrenergic responsiveness exist in normal and DCM states. More importantly, a disparity in RV and LV myocyte growth with DCM occurred. Thus, in this model of DCM, RV and LV growth and changes in contractile performance are not a homogenous process, and suggest that inherent differences exist in the response of RV and LV myocytes to stress