Relationship between blood remifentanil concentration and stress hormone levels during pneumoperitoneum in patients undergoing laparoscopic cholecystectomy

The effect of remifentanil on stress response to surgery is unclear. However, there are not clinical studies investigating the relationship between blood remifentanil concentrations and stress hormones. Therefore, the aim of the present study was to assess the association between blood remifentanil concentrations measured after pneumoperitoneum and cortisol (CORT) or prolactin (PRL) ratio (intraoperative/preoperative value), in patients undergoing laparoscopic cholecystectom

A two-level local search heuristic for pickup and delivery problems in express freight trucking

We consider a multiattribute vehicle routing problem inspired by a freight transportation company operating a fleet of heterogeneous trucks. The company offers an express service for requests including multiple pickup and multiple delivery positions spread in a regional area, with associated soft or hard time windows often falling in the same working day. Routes are planned on a daily basis and reoptimized on-the-fly to fit new requests, taking into account constraints and preferences on capacities, hours of service, route termination points. The objective is to maximize the difference between the revenue from satisfied orders and the operational costs. The problem mixes attributes from both intercity less-than-truckload and express couriers operations, and we propose a two-level local search heuristic. The first level assigns orders to vehicles through a variable neighborhood stochastic tabu search; the second level optimizes the route service sequences. The algorithm, enhanced by neighborhood filtering and parallel exploration, is embedded in a decision support tool currently in use in a small trucking company. Results have been compared to bounds obtained from a mathematical programming model solved by column generation. Experience on the field and test on literature instances attest to the quality of results and the efficiency of the proposed approach

The quantum mechanics of electric conduction in crystals

Permalink: http://dx.doi.org/10.1119/1.3436664We introduce a model of electrons incident on a one-dimensional periodic potential and show that conduction is a result of the interference of different parts of an electron wave that bounce multiple times through a series of potentials, ultimately being transmitted or reflected. Simple iterative equations are derived that determine the transmission and reflection coefficients of a periodic system.We find that total reflection of the electron occurs in certain energy ranges, as well as ranges of energy within which complete transmission can occur. The energy ranges in which transmission occurs are equivalent to the conduction bands traditionally found using Bloch's theorem. These equations are solved numerically, allowing a concrete demonstration of conduction. The disordered case is also addressed.This work was supported in part by the National Science Foundation under Grant No. DMR-0705460 and the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357

Effect of manure application timing on roots, canopy and must quality in Vitis vinifera 'Merlot': a case study in Italy, North-East

The maintenance and improvement of soil fertility are among the most important management practices in viticulture. The system efficiency fertilization (SEF) which is a new concept based on a maximum utilization of organic fertilizers (i.e., manure) has become very important, especially within the organic viticulture sector, since other fertilizers are not allowed. The aim of this study was to determine the effect of different manure application timing on the root, shoot, and the grapevine yield, accumulation, and quality of biochemical compounds in the grape must since the timing effect was not previously investigated. The study was carried out on 'Merlot' variety organically cultivated, whose production aims at obtaining high-quality red wines. Three treatments were applied: NT (Non-Treated), T1 (Treated1- manure applied in late October) and T2 (Treated2 - manure applied in late February). After two study-years, the undertaken research has shown positive influences of soil manure application on the canopy features (T1), yield, and yield components (T2), along with a major accumulation of the primary metabolites (T2) (soluble solid, carbohydrates, chlorophyll). Yet, the secondary metabolites (polyphenols and anthocyanins) were promoted in the grape must at harvest time, especially when the manure was applied in late October (T2). Considering the benefits of manure application in the T2, after two study years, this timing is recommended in order to improve 'Merlot' grapes for high-quality red wine production

A multianalytical approach to investigate stone biodeterioration at a UNESCO world heritage site: the volcanic rock-hewn churches of Lalibela, Northern Ethiopia.

A multianalytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy, and Microbiological techniques has been applied to characterize decay products and processes occurring at the surface of two rockhewn churches (Bete Gyorgis and Bete Amanuel) at the UNESCO’s World Heritage site of Lalibela, Northern Ethiopia. The two churches were carved into volcanic scoria deposits of basaltic composition. In their geological history, the Lalibela volcanic rocks underwent late to post-magmatic hydrothermal alteration together with partial laterization and are therefore characterized by a decay-prone highly vesicular microtexture with late stage to post-magmatic precipitation of secondary mineral phases (calcite–zeolite–smectite). The main objective of the study was to gain a better insight into the weathering products and mechanisms affecting the surface of the stone monuments and to assess the relative contribution of natural “geological” weathering processes versus biological/salt attack in stone decay at this unique heritage site. Results indicate that while the main cause of bulk rock deterioration and structural failure could be related to the stone inherited “geological” features, biological attack by micro- (bacteria) and/or macro- (lichens) organisms is currently responsible for severe stone surface physical and chemical weathering leading to significant weakening of the stone texture and to material loss at the surface of the churches walls. A prompt and careful removal of the biological patinas with the correct biocidal treatment is therefore recommended

Hemodynamic Corelates of Abnormal Aortic Root Dimension in an Adult Population:The Strong Heart Study.

We evaluated the relationship of aortic root dimension (ARD) with flow output and both peripheral and central blood pressure, using multivariable equations predicting ideal sex-specific ARD at a given age and body height

On 't Hooft's S-matrix Ansatz for quantum black holes

The S-matrix Ansatz has been proposed by 't Hooft to overcome difficulties and apparent contradictions of standard quantum field theory close to the black hole horizon. In this paper we revisit and explore some of its aspects. We start by computing gravitational backreaction effects on the properties of the Hawking radiation and explain why a more powerful formalism is needed to encode them. We then use the map bulk-boundary fields to investigate the nature of exchange algebras satisfied by operators associated with ingoing and outgoing matter. We propose and comment on some analogies between the non covariant form of the S-matrix amplitude and liquid droplet physics to end up with similarities with string theory amplitudes via an electrostatic analogy. We finally recall the difficulties that one encounters when trying to incorporate non linear gravity effects in 't Hooft's S-matrix and observe how the inclusion of higher order derivatives might help in the black hole microstate counting.Comment: 22 Pages. Latex Fil

A multianalytical approach to investigate stone biodeterioration at a UNESCO world heritage site: the volcanic rock-hewn churches of Lalibela, Northern Ethiopia.

A multianalytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy, and Microbiological techniques has been applied to characterize decay products and processes occurring at the surface of two rockhewn churches (Bete Gyorgis and Bete Amanuel) at the UNESCO’s World Heritage site of Lalibela, Northern Ethiopia. The two churches were carved into volcanic scoria deposits of basaltic composition. In their geological history, the Lalibela volcanic rocks underwent late to post-magmatic hydrothermal alteration together with partial laterization and are therefore characterized by a decay-prone highly vesicular microtexture with late stage to post-magmatic precipitation of secondary mineral phases (calcite–zeolite–smectite). The main objective of the study was to gain a better insight into the weathering products and mechanisms affecting the surface of the stone monuments and to assess the relative contribution of natural “geological” weathering processes versus biological/salt attack in stone decay at this unique heritage site. Results indicate that while the main cause of bulk rock deterioration and structural failure could be related to the stone inherited “geological” features, biological attack by micro- (bacteria) and/or macro- (lichens) organisms is currently responsible for severe stone surface physical and chemical weathering leading to significant weakening of the stone texture and to material loss at the surface of the churches walls. A prompt and careful removal of the biological patinas with the correct biocidal treatment is therefore recommended