Economic integration and security in the Middle East and North Africa: what prospects for a liberal peace?

Since the late 1980s governments in the Middle East and North Africa (MENA) have created commercial institutions in order to promote regional economic integration. The primary aim of this policy has been regarded as the promotion of economic welfare gains at the national level. A second, albeit less-emphasized goal, has been to promote regional peace through economic interdependence. This study examines the prospects for a liberal peace in the MENA by analyzing two stages of the commercial institutional peace. Firstly, the study considers whether commercial institutions have promoted intra-regional trade in the MENA. Secondly, it examines if economic interaction has had an impact on promoting peace within the region. Twenty states are considered here and the unit of analysis is the dyad-year over a 25-year period from 1990-2014. This study finds that commercial institutions in the MENA have only a limited positive correlation with trade volume and while there is a direct positive correlation between economic integration and peace in the region, this is quite limited. These findings suggest that the conclusions made by previous studies that demonstrate a direct positive correlation between commercial institutions (and economic integration more generally) and peace, may be less applicable to some regions such as MENA

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability

The Scales Project, a cross-national dataset on the interpretation of thermal perception scales

Thermal discomfort is one of the main triggers for occupants' interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses

The Scales Project, a cross-national dataset on the interpretation of thermal perception scales

Thermal discomfort is one of the main triggers for occupants’ interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses

Matrix Metalloproteinases in Cytotoxic Lymphocytes Impact on Tumour Infiltration and Immunomodulation

To efficiently combat solid tumours, endogenously or adoptively transferred cytotoxic T cells and natural killer (NK) cells, need to leave the vasculature, traverse the interstitium and ultimately infiltrate the tumour mass. During this locomotion and migration in the three dimensional environment many obstacles need to be overcome, one of which is the possible impediment of the extracellular matrix. The first and obvious one is the sub-endothelial basement membrane but the infiltrating cells will also meet other, both loose and tight, matrix structures that need to be overridden. Matrix metalloproteinases (MMPs) are believed to be one of the most important endoprotease families, with more than 25 members, which together have function on all known matrix components. This review summarizes what is known on synthesis, expression patterns and regulation of MMPs in cytotoxic lymphocytes and their possible role in the process of tumour infiltration. We also discuss different functions of MMPs as well as the possible use of other lymphocyte proteases for matrix degradation

Digital Controller Design For A Practicing Power Electronics Engineer

Practical digital controller design for switching power converters is addressed in this paper. A simplified direct-digital design approach is proposed where digital compensation tools are analyzed in the familiar analog frequency domain. The design is based on traditional concepts and tools such as Bode plots, zero/pole insertion, and gain/phase margins. In contrast to analog redesign methods, this approach is able to accurately account for loop parasitics such as zero-order holds and computational delays and predict the system response. It does not entail the creation of a discrete-time model of the controlled plant, necessary for other direct-digital design approaches. Families of compensation zeros/poles are presented. Notably powerful are two families of complex zero pairs, able to create a sharp phase boost of 180 degrees, specifically useful for converters with high-Q filters. A numbering system is introduced that enables simple -yet optimized- number representation within a fixed-point environment. This system is utilized to model different controller blocks, and to construct a blue-print of the controller code. A design example is then used to demonstrate the design methodology. Experimental results of a matching prototype are then presented that show close correspondence to theoretical and simulation predictions. © 2007 IEEE

Tubeless percutaneous nephrolithotomy with and without a hemostatic product: A prospective, randomized study

INTRODUCTION: Guidelines for the use of topical hemostatic products have not been established and their necessity for every case is not determined. The purpose of the present prospective, randomized study was to compare the outcomes of tubeless percutaneous nephrolithotomy (PNL) with and without a hemostatic agent. METHODS: A total of 48 patients with lower calyceal, middle calyceal, or pelvic renal stones ≤ 3 cm were randomly divided into 2 equal groups. All patients received single-stage tubeless PNL through 1 access tract. Group 1 had no local hemostatic agent; group 2 had oxidized regenerated cellulose (Surgicel; Ethicon Inc, Somerville, NJ, USA). Plain kidney, ureter, bladder X-ray and renal ultrasound were performed at the frst postoperative day to evaluate the stone-free rate and detect any perinephric hematoma. Postoperative urinary leakage and postoperative hemoglobin (Hb) were also measured. Patients had ultrasound to determine the amount of the perinephric collection before being discharged. RESULTS: No postoperative urinary leakage through the percutaneous tract was detected in either group. The mean (standard deviation) postoperative reduction in Hb concentration was 1.13 g/dL (1.11) for patients in group 1 and 1 g/dL (0.76) for patients in group 2; the group difference was not signifcant (P =.20). Most patients had no postoperative perinephric collection; minimal collection of 1 cm x 0.5 cm was detected in 2 cases in group 1 and 3 cases in group 2 (P =.30). No patient in either group had perinephric hematoma. Most patients were stone free: 22 patients (91.7%) in group 1; 20 patients (83.3%) in group 2. CONCLUSIONS: Topical hemostatic agents may not be needed after an uncomplicated percutaneous renal procedure. © 2010 UroToday International Journal