Abnormalities of the ventilatory equivalent for carbon dioxide in patients with chronic heart failure

Introduction. The relation between minute ventilation (VE) and carbon dioxide production (VCO2) can be characterised by the instantaneous ratio of ventilation to carbon dioxide production, the ventilatory equivalent for CO2 (VEqCO2). We hypothesised that the time taken to achieve the lowest VEqCO2 (time to VEqCO2 nadir) may be a prognostic marker in patients with chronic heart failure (CHF). Methods. Patients and healthy controls underwent a symptom-limited, cardiopulmonary exercise test (CPET) on a treadmill to volitional exhaustion. Results. 423 patients with CHF (mean age 63±12 years; 80% males) and 78 healthy controls (62% males; age 61±11 years) were recruited. Time to VEqCO2 nadir was shorter in patients than controls (327±204 s versus 514±187 s; P=0.0001). Univariable predictors of all-cause mortality included peak oxygen uptake (X 2 =53.0), VEqCO2 nadir (X 2 =47.9), and time to VEqCO2 nadir (X 2 =24.0). In an adjusted Cox multivariable proportional hazards model, peak oxygen uptake (X 2 =16.7) and VEqCO2 nadir (X 2 =17.9) were the most significant independent predictors of all-cause mortality. Conclusion. The time to VEqCO2 nadir was shorter in patients with CHF than in normal subjects and was a predictor of subsequent mortality. © 2012 Lee Ingle et al

A Cost Analysis of Carpal Tunnel Release Surgery Performed Wide Awake versus under Sedation.

BACKGROUND: Hand surgery under local anesthesia only has been used more frequently in recent years. The purpose of this study was to compare perioperative time and cost for carpal tunnel release performed under local anesthesia ( wide-awake local anesthesia no tourniquet, or WALANT) only to carpal tunnel release performed under intravenous sedation. METHODS: A retrospective comparison of intraoperative (operating room) surgical time and postoperative (postanesthesia care unit) time for consecutive carpal tunnel release procedures performed under both intravenous sedation and wide-awake local anesthesia was undertaken. All operations were performed by the same surgeon using the same mini-open surgical technique. A cost analysis was performed by means of standardized anesthesia billing based on base units, time, and conversion rates. RESULTS: There were no significant differences between the two groups in terms of total operative time, 28 minutes in the intravenous sedation group versus 26 minutes in the wide-awake local anesthesia group. Postanesthesia care unit times were significantly longer in the intravenous sedation group (84 minutes) compared to the wide-awake local anesthesia group (7 minutes). Depending on conversion rates used, a total of $139 to$432 was saved in each case performed with wide-awake local anesthesia by not using anesthesia services. In addition, a range of $1320 to$1613 was saved for the full episode of care, including anesthesia costs, operating room time, and postanesthesia care unit time for each patient undergoing wide-awake local anesthesia carpal tunnel release. CONCLUSION: Carpal tunnel release surgery performed with the wide-awake local anesthesia technique offers significant reduction in cost for use of anesthesia and postanesthesia care unit resources

Oxidised cosmic acceleration

We give detailed proofs of several new no-go theorems for constructing flat four-dimensional accelerating universes from warped dimensional reduction. These new theorems improve upon previous ones by weakening the energy conditions, by including time-dependent compactifications, and by treating accelerated expansion that is not precisely de Sitter. We show that de Sitter expansion violates the higher-dimensional null energy condition (NEC) if the compactification manifold M is one-dimensional, if its intrinsic Ricci scalar R vanishes everywhere, or if R and the warp function satisfy a simple limit condition. If expansion is not de Sitter, we establish threshold equation-of-state parameters w below which accelerated expansion must be transient. Below the threshold w there are bounds on the number of e-foldings of expansion. If M is one-dimensional or R everywhere vanishing, exceeding the bound implies the NEC is violated. If R does not vanish everywhere on M, exceeding the bound implies the strong energy condition (SEC) is violated. Observationally, the w thresholds indicate that experiments with finite resolution in w can cleanly discriminate between different models which satisfy or violate the relevant energy conditions.Comment: v2: corrections, references adde

Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell

PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Researching corporate social responsibility in the Middle East - the current state and future directions

Corporate social responsibility (CSR) has the potential to yield economic and social value in the Middle East (ME), especially given the current high environmental flux in the region. Although much scholarly has been paid to CSR issues, a key question remains about how to operate responsibly in the ME, particularly since institutional environments and stakeholders’ needs vary across ME states. The purpose of this paper is to provide a systematic review of the current state of CSR in the ME. We identify thirty-eight articles that are most pertinent to CSR in the ME and examine the main theoretical frameworks, methodologies, trajectories for further conceptual development, gaps where new research pathways need to be created and also future research questions. From the systematic review, we reveal how attention on CSR in the ME is slowly gaining traction. A snapshot of the gaps identified include the collaboration between business and NGOs, the impact of stakeholders and institutions on CSR, the impact of political and economic crisis on CSR and the influence of individualistic characteristics shaping managers’ CSR behaviour. In addition to such gaps, we present an agenda for future research

Visuo-spatial ability in colonoscopy simulator training

Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To remedy this situation, the current study investigated the role of a broad range of visuo-spatial factors in colonoscopy simulator training. Fifteen medical trainees (no clinical experience in colonoscopy) participated in two psycho-metric test sessions to assess four visuo-spatial ability factors. Next, participants trained flexible endoscope manipulation, and navigation to the cecum on the GI Mentor II simulator, for four sessions within 1 week. Visualization, and to a lesser degree Spatial relations were the only visuo-spatial ability factors to correlate with colonoscopy simulator performance. Visualization additionally covaried with learning rate for time on task on both simulator tasks. High Visualization ability indicated faster exercise completion. Similar to other endoscopic procedures, performance in colonoscopy is positively associated with Visualization, a visuo-spatial ability factor characterized by the ability to mentally manipulate complex visuo-spatial stimuli. The complexity of the visuo-spatial mental transformations required to successfully perform colonoscopy is likely responsible for the challenging nature of this technique, and should inform training- and assessment design. Long term training studies, as well as studies investigating the nature of visuo-spatial complexity in this domain are needed to better understand the role of visuo-spatial ability in colonoscopy, and other endoscopic techniques

Comparison of Recent SnIa datasets

We rank the six latest Type Ia supernova (SnIa) datasets (Constitution (C), Union (U), ESSENCE (Davis) (E), Gold06 (G), SNLS 1yr (S) and SDSS-II (D)) in the context of the Chevalier-Polarski-Linder (CPL) parametrization $w(a)=w_0+w_1 (1-a)$, according to their Figure of Merit (FoM), their consistency with the cosmological constant ($\Lambda$CDM), their consistency with standard rulers (Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO)) and their mutual consistency. We find a significant improvement of the FoM (defined as the inverse area of the 95.4% parameter contour) with the number of SnIa of these datasets ((C) highest FoM, (U), (G), (D), (E), (S) lowest FoM). Standard rulers (CMB+BAO) have a better FoM by about a factor of 3, compared to the highest FoM SnIa dataset (C). We also find that the ranking sequence based on consistency with $\Lambda$CDM is identical with the corresponding ranking based on consistency with standard rulers ((S) most consistent, (D), (C), (E), (U), (G) least consistent). The ranking sequence of the datasets however changes when we consider the consistency with an expansion history corresponding to evolving dark energy $(w_0,w_1)=(-1.4,2)$ crossing the phantom divide line $w=-1$ (it is practically reversed to (G), (U), (E), (S), (D), (C)). The SALT2 and MLCS2k2 fitters are also compared and some peculiar features of the SDSS-II dataset when standardized with the MLCS2k2 fitter are pointed out. Finally, we construct a statistic to estimate the internal consistency of a collection of SnIa datasets. We find that even though there is good consistency among most samples taken from the above datasets, this consistency decreases significantly when the Gold06 (G) dataset is included in the sample.Comment: 13 pages, 9 figures. Included recently released SDSS-II dataset. Improved presentation. Main results unchanged. The mathematica files and datasets used for the production of the figures may be downloaded from http://leandros.physics.uoi.gr/datacomp

Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka

Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions

Blue Bird

https://digitalcommons.library.umaine.edu/mmb-vp/3039/thumbnail.jp