The contribution of molecular relaxation in nitrogen to the absorption of sound in the atmosphere

Results and statistical analysis are presented for sound absorption in N2-H2O binary mixtures at room temperature. Experimental procedure, temperature effects, and preliminary results are presented for sound absorption in N2-H2O binary mixtures at elevated temperatures

Wave Profile for Anti-force Waves with Maximum Possible Currents

In the theoretical investigation of the electrical breakdown of a gas, we apply a one-dimensional, steady state, constant velocity, three component fluid model and consider the electrons to be the main element in propagation of the wave. The electron gas temperature, and therefore the electron gas partial pressure, is considered to be large enough to provide the driving force. The wave is considered to have a shock front, followed by a thin dynamical transition region. Our set of electron fluid-dynamical equations consists of the equations of conservation of mass, momentum, and energy, plus the Poisson\u27s equation. The set of equations is referred to as the electron fluid dynamical equations; and a successful solution therefor must meet a set of acceptable physical conditions at the trailing edge of the wave. For breakdown waves with a significant current behind the shock front, modifications must be made to the set of electron fluid dynamical equations, as well as the shock condition on electron temperature. Considering existence of current behind the shock front, we have derived the shock condition on electron temperature, and for a set of experimentally measured wave speeds, we have been able to find maximum current values for which solutions to our set of electron velocity, electron temperature, and electron number density within the dynamical transition region of the wave

Propagation of sound through the Earth's atmosphere. 1: Measurement of sound absorption in the air. 2: Measurement of ground impedance

The fabrication of parts for the acoustic ground impedance meter was completed, and the instrument tested. Acoustic ground impedance meter, automatic data processing system, cooling system for the resonant tube, and final results of sound absorption in N2-H2O gas mixtures at elevated temperatures are described

Management considerations of massive hemoptysis while on extracorporeal membrane oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is a life-saving procedure in patients with both respiratory and cardiac failure. Bleeding complications are common since patients must be maintained on anticoagulation. Massive hemoptysis is a rare complication of ECMO; however, it may result in death if not managed thoughtfully and expeditiously. METHODS: A retrospective chart review was performed of consecutive ECMO patients from 7/2010-8/2014 to identify episodes of massive hemoptysis. The management of and the outcomes in these patients were studied. Massive hemoptysis was defined as an inability to control bleeding (\u3e300 mL/day) from the endotracheal tube with conventional maneuvers, such as bronchoscopy with cold saline lavage, diluted epinephrine lavage and selective lung isolation. All of these episodes necessitated disconnecting the ventilator tubing and clamping the endotracheal tube, causing full airway tamponade. RESULTS: During the period of review, we identified 118 patients on ECMO and 3 (2.5%) patients had the complication of massive hemoptysis. One case was directly related to pulmonary catheter migration and the other two were spontaneous bleeding events that were propagated by antiplatelet agents. All three patients underwent bronchial artery embolization in the interventional radiology suite. Anticoagulation was held during the period of massive hemoptysis without any embolic complications. There was no recurrent bleed after appropriate intervention. All three patients were successfully separated from ECMO. CONCLUSIONS: Bleeding complications remain a major issue in patients on ECMO. Disconnection of the ventilator and clamping the endotracheal tube with full respiratory and cardiac support by V-A ECMO is safe. Early involvement of interventional radiology to embolize any potential sources of the bleed can prevent re-hemoptysis and enable continued cardiac and respiratory recovery

Low-frequency sound absorption measurements in air

Thirty sets of sound absorption measurements in air at a pressure of 1 atmosphere are presented at temperatures from 10 C to 50 C, relative humidities from 0 to 100 percent, and frequencies from 10 to 2500 Hz. The measurements were conducted by the method of free decay in a resonant tube having a length of 18.261 m and bore diameter of 0.152 m. Background measurements in a gas consisting of 89.5 percent N2 and 10.5 percent Ar, a mixture which has the same sound velocity as air, permitted the wall and structural losses of the tube to be separated from the constituent absorption, consisting of classical rotational and vibrational absorption, in the air samples. The data were used to evaluate the vibrational relaxation frequencies of N2 and/or O2 for each of the 30 sets of meteorological parameters. Over the full range of humidity, the measured relaxation frequencies of N2 in air lie between those specified by ANSI Standard S1.26-1978 and those measured earlier in binary N2H2O mixtures. The measured relaxation frequencies could be determined only at very low values of humidity, reveal a significant trend away from the ANSI standard, in agreement with a prior investigation

Misalignment of Expectations for Entry-Level IT Auditors

Information systems auditing is a growing profession. In order for information technology educators to help keep up with the demand for information systems audit professionals, more understanding is needed about the knowledge, skills and abilities required for entry-level IT auditors. In our ongoing research, we have analyzed several sources to identify such skills. In the process we noted that there are gaps between what academics, practitioners, and professional associations see as the key skills required for success in this lucrative profession. We suggest reasons for such gaps and discuss potential future research opportunities

Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies

Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies

Type I interferon rapidly restricts infectious hepatitis C virus particle genesis

Interferon-alpha (IFNα) has been used to treat chronic hepatitis C virus (HCV) infection for over 20 years with varying efficacy, depending on the infecting viral genotype. The mechanism of action of IFNα is not fully understood, but is thought to target multiple stages of the HCV lifecycle, inhibiting viral transcription and translation leading to a degradation of viral RNA and protein expression in the infected cell. IFNα induces the expression of an array of interferon-stimulated genes within minutes of receptor engagement; however, the impact of these early responses on the viral lifecycle are unknown. We demonstrate that IFNα inhibits the genesis of infectious extracellular HCV particles within 2 hours of treating infected cells, with minimal effect on the intracellular viral burden. Importantly, this short duration of IFNα treatment of infected cells significantly reduced cell-free and cell-to-cell dissemination. The secreted viral particles showed no apparent change in protein content or density, demonstrating that IFNα inhibits particle infectivity but not secretion rates. To investigate whether particles released from IFNα-treated cells have a reduced capacity to establish infection we used HCV lentiviral pseudotypes (HCVpp) and demonstrated a defect in cell entry. Using a panel of monoclonal antibodies targeting the E2 glycoprotein, we demonstrate that IFNα alters glycoprotein conformation and receptor utilization. Conclusion: These observations show a previously unreported and rapid effect of IFNα on HCV particle infectivity that inhibits de novo infection events. Evasion of this response may be a contributing factor in whether a patient achieves early or rapid virological response, a key indicator of progression to sustained virological response or clearance of viral infection. (Hepatology 2014;60:1890–1900