bluuebunny/crossref_metadata_2025 huggingface dataset:
Application-specific workload shaping in multimedia-enabled personal mobile devices
Authors: Raman Balaji , Chakraborty Samarjit
Published: February 2008

Today, most personal mobile devices (e.g., cell phones and PDAs) are multimedia-enabled and support a variety of concurrently running applications, such as audio/video players, word processors, and web browsers. Media-processing applications are often computationally expensive and most of these devices typically have 100--400-MHz processors. As a result, the user-perceived application response times are often poor when multiple applications are concurrently fired. In this paper, we show that by using application-specific dynamic buffering techniques, the workload of these applications can be suitably “shaped” to fit the available processor bandwidth. Our techniques are analogous to
traffic shaping
, which is widely used in communication networks to optimally utilize network bandwidth. Such shaping techniques have recently attracted a lot of attention in the context of embedded systems design (e.g., for dynamic voltage scaling). However, they have not been exploited for enhanced schedulability of multiple applications, as we do in this paper.
Dynamic scratchpad memory management for code in portable systems with an MMU
Authors: Egger Bernhard , Lee Jaejin , Shin Heonshik
Published: February 2008

In this work, we present a dynamic memory allocation technique for a novel, horizontally partitioned memory subsystem targeting contemporary embedded processors with a memory management unit (MMU). We propose to replace the on-chip instruction cache with a scratchpad memory (SPM) and a small minicache. Serializing the address translation with the actual memory access enables the memory system to access either only the SPM or the minicache. Independent of the SPM size and based solely on profiling information, a postpass optimizer classifies the code of an application binary into apageableand acacheablecode region. The latter is placed at a fixed location in the external memory and cached by the minicache. The former, the pageable code region, is copied on demand to the SPM before execution. Both the pageable code region and the SPM are logically divided into pages the size of an MMU memory page. Using the MMU's pagefault exception mechanism, a runtime scratchpad memory manager (SPMM) tracks page accesses and copies frequently executed code pages to the SPM before they get executed. In order to minimize the number of page transfers from the external memory to the SPM, good code placement techniques become more important with increasing sizes of the MMU pages. We discuss code-grouping techniques and provide an analysis of the effect of the MMU's page size on execution time, energy consumption, and external memory accesses. We show that by using the data cache as a victim buffer for the SPM, significant energy savings are possible. We evaluate our SPM allocation strategy with fifteen applications, including H.264, MP3, MPEG-4, and PGP. The proposed memory system requires 8% less die are compared to a fully-cached configuration. On average, we achieve a 31% improvement in runtime performance and a 35% reduction in energy consumption with an MMU page size of 256 bytes.
Minimal placement of bank selection instructions for partitioned memory architectures
Authors: Scholz Bernhard , Burgstaller Bernd , Xue Jingling
Published: February 2008

We have devised an algorithm for minimal placement of bank selections in partitioned memory architectures. This algorithm is parameterizable for a chosen metric, such as speed, space, or energy. Bank switching is a technique that increases the code and data memory in microcontrollers without extending the address buses. Given a program in which variables have been assigned to data banks, we present a novel optimization technique that minimizes the overhead of bank switching through cost-effective placement of bank selection instructions. The placement is controlled by a number of different objectives, such as runtime, low power, small code size or a combination of these parameters. We have formulated the minimal placement of bank selection instructions as a discrete optimization problem that is mapped to a partitioned boolean quadratic programming (PBQP) problem. We implemented the optimization as part of a PIC Microchip backend and evaluated the approach for several optimization objectives. Our benchmark suite comprises programs from MiBench and DSPStone plus a microcontroller real-time kernel and drivers for microcontroller hardware devices. Our optimization achieved a reduction in program memory space of between 2.7 and 18.2%, and an overall improvement with respect to instruction cycles between 5.0 and 28.8%. Our optimization achieved the minimal solution for all benchmark programs. We investigated the scalability of our approach toward the requirements of future generations of microcontrollers. This study was conducted as a worst-case analysis on the entire MiBench suite. Our results show that our optimization (1) scales well to larger numbers of memory banks, (2) scales well to the larger problem sizes that will become feasible with future microcontrollers, and (3) achieves minimal placement for more than 72% of all functions from MiBench.
A unified hardware/software runtime environment for FPGA-based reconfigurable computers using BORPH
Authors: So Hayden Kwok-Hay , Brodersen Robert
Published: February 2008

This paper explores the design and implementation of BORPH, an operating system designed for FPGA-based reconfigurable computers. Hardware designs execute as normal UNIX processes under BORPH, having access to standard OS services, such as file system support. Hardware and software components of user designs may, therefore, run as communicating processes within BORPH's runtime environment. The familiar language independent UNIX kernel interface facilitates easy design reuse and rapid application development. To develop hardware designs, a Simulink-based design flow that integrates with BORPH is employed. Performances of BORPH on two on-chip systems implemented on a BEE2 platform are compared.
A design framework for real-time embedded systems with code size and energy constraints
Authors: Lee Sheayun , Shin Insik , Kim Woonseok , Lee Insup , Min Sang Lyul
Published: February 2008

Real-time embedded systems are typically constrained in terms of three system performance criteria: space, time, and energy. The performance requirements are directly translated into constraints imposed on the system's resources, such as code size, execution time, and energy consumption. These resource constraints often interact or even conflict with each other in a complex manner, making it difficult for a system developer to apply a well-defined design methodology in developing a real-time embedded system. Motivated by this observation, we propose a design framework that can flexibly balance the tradeoff involving the system's code size, execution time, and energy consumption. Given a system specification and an optimization criteria, the proposed technique generates a set of design parameters in such a way that a system cost function is minimized while the given resource constraints are satisfied. Specifically, the technique derives code generation decision for each task so that a specific version of code is selected among a number of different ones that have distinct characteristics in terms of code size and execution time. In addition, the design framework determines the voltage/frequency setting for a variable voltage processor whose supply voltage can be adjusted at runtime in order to minimize the energy consumption while execution performance is degraded accordingly. The proposed technique formulates this design process as a constrained optimization problem. We show that this optimization problem is NP-hard and then provide a heuristic solution to it. We show that these seemingly conflicting design goals can be pursued by using a simple optimization algorithm that works with a single optimization criteria. Moreover, the optimization is driven by an abstract system specification given by the system developer, so that the system development process can be automated. The results from our simulation show that the proposed algorithm finds a solution that is close to the optimal one with the average error smaller than 1.0%.
Deep network packet filter design for reconfigurable devices
Authors: Cho Young H. , Mangione-Smith William H.
Published: February 2008

Most network routers and switches provide some protection against the network attacks. However, the rapidly increasing amount of damages reported over the past few years indicates the urgent need for tougher security. Deep-packet inspection is one of the solutions to capture packets that can not be identified using the traditional methods. It uses a list of signatures to scan the entire content of the packet, providing the means to filter harmful packets out of the network. Since one signature does not depend on the other, the filtering process has a high degree of parallelism. Most software and hardware deep-packet filters that are in use today execute the tasks under Von Neuman architecture. Such architecture can not fully take advantage of the parallelism. For instance, one of the most widely used network intrusion-detection systems, Snort, configured with 845 patterns, running on a dual 1-GHz Pentium III system, can sustain a throughput of only 50 Mbps. The poor performance is because of the fact that the processor is programmed to execute several tasks sequentially instead of simultaneously. We designed scalable deep-packet filters on field-programmable gate arrays (FPGAs) to search for all data-independent patterns simultaneously. With FPGAs, we have the ability to reprogram the filter when there are any changes to the signature set. The smallest full-pattern matcher implementation for the latest Snort NIDS fits in a single 400k Xilinx FPGA (Spartan 3-XC3S400) with a sustained throughput of 1.6 Gbps. Given a larger FPGA, the design can scale linearly to support a greater number of patterns, as well as higher data throughput.
False-name bids in combinatorial auctions
Authors: Yokoo Makoto
Published: February 2008

In Internet auctions, it is easy for a bidder to submit multiple bids under multiple identifiers (e.g., multiple e-mail addresses). If only one good is sold, a bidder cannot make any additional profit by using multiple bids. However, in combinatorial auctions, where multiple goods are sold simultaneously, submitting multiple bids under fictitious names can be profitable. A bid made under a fictitious name is called a false-name bid. This article gives a brief introducion on false-name bids in combinatorial auctions.
Combinatorial betting
Authors: Chen Yiling , Fortnow Lance , Nikolova Evdokia , Pennock David M.
Published: February 2008

We discuss the design of combinatorial betting mechanisms. We characterize the computational complexity of several variants of the problem and pose some open research questions.
Dropping CS enrollments
Authors: Manaris Bill
Published: February 2008

According to CRA [1], the number of new CS majors dropped by approximately 50% from Fall 2000 to Fall 2006. So, what happened right before Fall 2001 when the CS enrollments started dropping?
A LAMP-LEGO experience of motivating minority students to study engineering
Authors: Qidwai Uvais A
Published: February 2008

In this paper, I would like to share my experience with Louisiana Alliance for Minority Participation Program (LAMP) in which I participated as a faculty mentor from Tulane University in New Orleans, Louisiana, USA. This program is aimed at improving the education level and the standards of education in certain areas where students are not encouraged to go to college or take basic sciences and engineering as their career. This is due to either lack of financial resources or lack of focus and motivation on part of the students, which in turn is due to several social problems probing into poverty and crimes' vicious circle. I have served in this program as a faculty mentor from an elite university and have made the students from minority colleges to participate directly with my own senior and graduate students to encourage them as to how they can be of the same caliber. Other than inter-personal skills, the use of Lego Mindstorm Robotics Invention system has shown a great increase in motivation and focusing the students towards Engineering Education.
Lessons learned from seven years of pair programming at North Carolina State University
Authors: Williams Laurie
Published: February 2008

A recent survey conducted on the SIGCSE mailing list indicated that up to 80% of CS1, CS2, and data structures instructors allow students to collaborate. The use of collaboration increases as students advance through the computer science curriculum. Some computer science educators use pair programming as the model for their student collaboration, sometimes with mixed results. At North Carolina State University, over a thousand students have pair programmed in CS1, undergraduate software engineering, and graduate level courses over the last seven years. This paper provides a summary of the lessons we have learned through experience and through extensive research over this period.
No slacker on team programming projects
Authors: Lorenzen Torben , Santore John , Glassman David , Baltikauskas Juozas
Published: February 2008

It is necessary for students to learn how to program in a team environment because they will be required to do so in industry after graduation. However, it is difficult to ensure that each student on an academic team is contributing significantly to the overall team effort. The authors describe several failed attempts to grade teamwork fairly and a new method that guarantees individual accountability in a team environment. This last method promotes fairness in grading each member's work on a team.
The role of social networks in students' learning experiences
Authors: Liccardi Ilaria , Ounnas Asma , Pau Reena , Massey Elizabeth , Kinnunen Päivi , Lewthwaite Sarah , Midy Marie-Anne , Sarkar Chandan
Published: February 2008

The aim of this research is to investigate the role of social networks in computer science education. The Internet shows great potential for enhancing collaboration between people and the role of social software has become increasingly relevant in recent years. This research focuses on analyzing the role that social networks play in students' learning experiences. The construction of students' social networks, the evolution of these networks, and their effects on the students' learning experience in a university environment are examined.
VISA
Authors: Assent Ira , Krieger Ralph , Müller Emmanuel , Seidl Thomas
Published: February 2008

To gain insight into today's large data resources, data mining extracts interesting patterns. To generate knowledge from patterns and benefit from human cognitive abilities, meaningful visualization of patterns are crucial. Clustering is a data mining technique that aims at grouping data to patterns based on mutual (dis)similarity. For high dimensional data, subspace clustering searches patterns in any subspace of the attributes as patterns are typically obscured by many irrelevant attributes in the full space. For visual analysis of subspace clusters, their comparability has to be ensured. Existing subspace clustering approaches, however, lack interactive visualization and show bias with respect to the dimensionality of subspaces.

In this work, dimensionality unbiased subspace clustering and a novel distance function for subspace clusters are proposed. We suggest two visualization techniques that allow users to browse the entire subspace clustering, to zoom into individual objects, and to analyze subspace cluster characteristics in-depth. Bracketing of different parameter settings enable users to immediately see the effect of parameters on their data and hence to choose the best clustering result for further analysis. Usage of user analysis for feedback to the subspace clustering algorithm directly improves the subspace clustering. We demonstrate our visualization techniques on real world data and confirm results through additional accuracy measurements and comparison with existing subspace clustering algorithms.
Managing discoveries in the visual analytics process
Authors: Yang Di , Xie Zaixian , Rundensteiner Elke A. , Ward Matthew O.
Published: February 2008

Visualization systems traditionally focus on graphical representation of information. They tend not to provide integrated analytical services that could aid users in tackling complex knowledge discovery tasks. Users' exploration in such environments is usually impeded due to several problems: 1) valuable information is hard to discover when too much data is visualized on the screen; 2) Users have to manage and organize their discoveries off line, because no systematic discovery management mechanism exists; 3) their discoveries based on visual exploration alone may lack accuracy; and 4)they have no convenient access to the important knowledge learned by other users. To tackle these problems, it has been recognized that analytical tools must be introduced into visualization systems. In this paper, we present a novel analysis-guided exploration system, called the Nugget Management System (NMS). It leverages the collaborative effort of human comprehensibility and machine computations to facilitate users' visual exploration processes. Specifically, NMS first helps users extract the valuable information (nuggets) hidden in datasets based on their interests. Given that similar nuggets may be rediscovered by different users, NMS consolidates the nugget candidate set by clustering based on their semantic similarity. To solve the problem of inaccurate discoveries, localized data mining techniques are applied to refine the nuggets to best represent the captured patterns in datasets. Visualization techniques are then employed to present our collected nugget pool and thus create the nugget view. Based on the nugget view, interaction techniques are designed to help users observe and organize the nuggets in a more intuitive manner and eventually faciliate their sense-making process. We integrated NMS into XmdvTool, a freeware multivariate visualization system. User studies were performed to compare the users' efficiency and accuracy in finishing tasks on real datasets, with and without the help of NMS. Our user studies confirmed the effectiveness of NMS.
Effect of temperature on cross-bridge properties in intact frog muscle fibers
Authors: Colombini Barbara , Nocella Marta , Benelli Giulia , Cecchi Giovanni , Bagni M. Angela
Published: February 2008

It is well known that the force developed by skeletal muscles increases with temperature. Despite the work done on this subject, the mechanism of force potentiation is still debated. Most of the published papers suggest that force enhancement is due to the increase of the individual cross-bridge force. However, reports on skinned fibers and single-molecule experiments suggest that cross-bridge force is temperature independent. The effects of temperature on cross-bridge properties in intact frog fibers were investigated in this study by applying fast stretches at various tension levels ( P) on the tetanus rise at 5°C and 14°C to induce cross-bridge detachment. Cross-bridge number was measured from the force (critical force, Pc) needed to detach the cross-bridge ensemble, and the average cross-bridge strain was calculated from the sarcomere elongation needed to reach Pc (critical length, Lc). Our results show that P c increased linearly with the force developed at both temperatures, but the P c /P ratio was considerably smaller at 14°C. This means that the average force per cross bridge is greater at high temperature. This mechanism accounts for all the tetanic force enhancement. The critical length L c was independent of the tension developed at both temperatures but was significantly lower at high temperature suggesting that cross bridges at 14°C are more strained. The increased cross-bridge strain accounts for the greater average force developed.
Head Movements Produced During Whole Body Rotations and Their Sensitivity to Changes in Head Inertia in Squirrel Monkeys
Authors: Reynolds J. S. , Gdowski G. T.
Published: February 2008

The head's inertia produces forces on the neck when the body moves. One collective function of the vestibulocollic and cervicocollic reflexes (VCR and CCR) is thought to be to stabilize the head with respect to the trunk during whole body movements. Little is known as to whether their head-movement kinematics produced by squirrel monkeys during whole body rotations are similar to those of cats and humans. Prior experiments with cats and human subjects have shown that yaw head-movement kinematics are unaffected by changes in the head's inertia when the whole body is rotated. These observations have led to the hypothesis that the combined actions of the VCR and CCR accommodate for changes in the head's inertia. To test this hypothesis in squirrel monkeys, it was imperative to first characterize the behavior of head movements produced during whole body rotation and then investigate their sensitivity to changes in the head's inertia. Our behavioral studies show that squirrel monkeys produce only small head movements with respect to the trunk during whole body rotations over a wide range of stimulus frequencies and velocities (0.5–4.0 Hz; 0–100°/s). Similar head movements were produced when only small additional changes in the head's inertia occurred. Electromyographic recordings from the splenius muscle revealed that an active process was utilized such that increases in muscle activation occurred when the inertia of the head was increased. These results are consistent with prior cat and human studies, suggesting that squirrel monkeys have a similar horizontal VCR and CCR.
Distribution of Natural Radioactivity,137Cs,90Sr, and Plutonium Isotopes in a Water Column and Sediment Core along the Algerian Coast
Authors: Noureddine A. , Benkrid M. , Maoui R. , Menacer M. , Boudjenoun R.
Published: February 2008

Concentrations of natural (40K,210Pb, uranium, and thorium series) and artificial radioelements (137Cs,90Sr,239+240Pu) were determined in seawater and sediment samples collected from stations along the Algerian coast. Seawater was collected from the surface to a maximum depth of 2000 m; the sediment cores were sampled from a depth of around 1500 m. This work was carried out in August 2001, in the framework of the Regional African project /7/004 (RAF), by the accomplishment of an oceanographic campaign organized by the International Atomic Energy Agency (IAEA) in collaboration with Commissariat à l'Energie Atomique (COMENA) and L'Institut des Sciences de la Mer et de L'Amenagement du Littoral (ISMAL), on board of the research vessel of M.S. Benyahia of ISMAL. In addition to the record of the conductivity (mS) and temperature (°C) data at each station, seawater samples were treated and preconcentrated on board, those of sediment cores were divided into different layers in order to undergo analyses in the laboratory of radiological impact studies of Algiers. Concentration results were obtained for137Cs and90Sr in mBq/L and239+240Pu inμBq/L in seawater, and also for natural and artificial radionuclides in Bq/kg dry weight in the layers of the sediment cores. The different profiles of137Cs,239+240Pu,90Sr, and210Pb concentrations against depth were presented to show artificial radioactivity distribution in the water column and sediment core. Concentrations of137Cs in the sediment core were also used to identify the137Cs peak in the area of interest.
Combining Microarray Technology and Molecular Epidemiology to Identify Genes Associated with Invasive Group BStreptococcus
Authors: Zhang Lixin , Reddi Usha , Srinivasan Usha , Li Sheng , Borchardt Stephanie M. , Pillai Parvathy , Mehta Puja , Styka Anne N. , DeBusscher Joan , Marrs Carl F. , Foxman Betsy
Published: February 2008

Many bacterial species function as both commensals and pathogens; we used this dual nature to develop a high-throughput molecular epidemiological approach to identifying bacterial virulence genes. We applied our approach to Group BStreptococcus(GBS). Three representative commensal and one invasive GBS isolates were selected as tester strains from a population-based collection. We used microarray-based comparative genomic hybridization to identify open reading frames (ORFs) present in two sequenced invasive strains, but absent or divergent in tester strains. We screened 23 variable ORFs against 949 GBS isolates using a GBS Library on a Slide (LOS) microarray platform. Four ORFs occurred more frequently in invasive than commensal isolates, and one appeared more frequently in commensal isolates. Comparative hybridization using an oligonucleotide microarray, combined with epidemiologic screening using the LOS microarray platform, enabled rapid identification of bacterial genes potentially associated with pathogenicity.
Characterization of Phototransduction Gene Knockouts Revealed Important Signaling Networks in the Light‐ Induced Retinal Degeneration
Authors: Krishnan Jayalakshmi , Lee Gwang , Han Sang-Uk , Choi Sangdun
Published: February 2008

Understanding the molecular pathways mediating neuronal function in retinas can be greatly
facilitated by the identification of genes regulated in the retinas of different mutants under
various light conditions. We attempted to conduct a gene chip analysis study on the genes
regulated during rhodopsin kinase (Rhok−/−) and arrestin (Sag−/−) knockout and double knockouts in mice retina. Hence, mice were exposed to constant illumination of 450 lux or 6,000 lux on dilated pupils for indicated periods. The retinas were removed after the exposure and processed for microarray analysis. Double knockout was associated with immense changes in gene expression regulating a number of apoptosis inducing transcription factors. Subsequently, network analysis revealed that during early exposure the transcription factors, p53, c‐MYC, c‐FOS, JUN, and, in late phase, NF‐κB, appeared to be essential for the initiation of light‐induced retinal rod loss, and some other classical pro‐ and antipoptotic genes appeared to be significantly important as well.
Periodic Oscillation of Fuzzy Cohen‐Grossberg Neural Networks with Distributed Delay and Variable Coefficients
Authors: Xiang Hongjun , Cao Jinde
Published: February 2008

A class of fuzzy Cohen‐Grossberg neural networks with distributed delay and variable coefficients is discussed.
It is neither employing coincidence degree theory nor constructing Lyapunov functionals, instead, by applying matrix theory and inequality analysis, some sufficient conditions are obtained to ensure the existence, uniqueness, global attractivity and global exponential stability of the periodic solution for the fuzzy Cohen‐Grossberg neural networks. The method is very concise and practical. Moreover, two examples are posed to illustrate the effectiveness of our results.
Synthesis, Characterization, and Biological Activity of N1‐Methyl‐2‐(1H‐1,2,3‐Benzotriazol‐1‐y1)‐3‐Oxobutan‐ ethioamide Complexes with Some Divalent Metal (II) Ions
Authors: Al-Awadi Nouria A. , Shuaib Nadia M. , Abbas Alaa , El-Sherif Ahmed A. , El-Dissouky Ali , Al-Saleh Esmaeil
Published: February 2008

A new series of Zn2+, Cu2+, Ni2+, and Co2+ complexes of N1‐methyl‐2‐(1H‐1,2,3‐benzotriazol‐1‐yl)‐3‐oxobutanethioamide (MBOBT), HL, has been synthesized and characterized by different spectral and magnetic measurements and elemental analysis. IR spectral data indicates that (MBOBT) exists only in the thione form in the solid state while
13C NMR spectrum indicates its existence in thione and thiole tautomeric forms. The IR spectra of all complexes indicate that (MBOBT) acts as a monobasic bidentate ligand coordinating to the metal(II) ions via the keto‐oxygen and thiolato‐sulphur
atoms. The electronic spectral studies showed that (MBOBT) bonded to all metal ions through sulphur and nitrogen atoms based on the positions and intensity of their charge transfer bands. Furthermore, the spectra reflect four coordinate tetrahedral zinc(II), tetragonally distorted copper(II), square planar nickel(II),
and cobalt(II) complexes. Thermal decomposition study of the complexes was monitored by TG and
DTG analyses under N2 atmosphere. The decomposition course and steps were analyzed and the activation parameters of the nonisothermal decomposition are determined. The isolated metal chelates have been screened for their antimicrobial activities and the findings have been reported and discussed in relation to their structures.
A Sufficient Condition for Asymptotic Stability of Discrete‐Time Interval System with Delay
Authors: Zhu Wei
Published: February 2008

The asymptotic stability of discrete‐time interval
system with delay is discussed. A new sufficient condition for preserving the
asymptotic stability of the system is presented by means of the inequality
techniques. By mathematical analysis, the stability criterion is less conservative
than that in previous result. Finally, one example is given to demonstrate
the applicability of the present scheme.
Fault Detection, Isolation, and Accommodation for LTI Systems Based on GIMC Structure
Authors: Campos-Delgado D. U. , Palacios E. , Espinoza-Trejo D. R.
Published: February 2008

In this contribution, an active fault‐tolerant scheme that achieves fault detection, isolation, and accommodation is developed for LTI systems. Faults and perturbations are considered as additive signals that modify the state or output equations. The accommodation scheme is based on the generalized internal model control architecture recently proposed for fault‐tolerant control. In order to improve the performance after a fault, the compensation is considered in two steps according with a fault detection and isolation algorithm. After a fault scenario is detected, a general fault compensator is activated. Finally, once the fault is isolated, a specific compensator is introduced. In this setup, multiple faults could be treated simultaneously since their effect is additive. Design strategies for a nominal condition and under model uncertainty are presented in the paper. In addition, performance indices are also introduced to evaluate the resulting fault‐tolerant scheme for detection, isolation, and accommodation. Hard thresholds are suggested for detection and isolation purposes, meanwhile, adaptive ones are considered under model uncertainty to reduce the conservativeness. A complete simulation evaluation is carried out for a DC motor setup.
Role of Mitochondrial Dysfunction in Insulin Resistance
Authors: Kim Jeong-a , Wei Yongzhong , Sowers James R.
Published: February 2008

Insulin resistance is characteristic of obesity, type 2 diabetes, and components of the cardiometabolic syndrome, including hypertension and dyslipidemia, that collectively contribute to a substantial risk for cardiovascular disease. Metabolic actions of insulin in classic insulin target tissues (eg, skeletal muscle, fat, and liver), as well as actions in nonclassic targets (eg, cardiovascular tissue), help to explain why insulin resistance and metabolic dysregulation are central in the pathogenesis of the cardiometabolic syndrome and cardiovascular disease. Glucose and lipid metabolism are largely dependent on mitochondria to generate energy in cells. Thereby, when nutrient oxidation is inefficient, the ratio of ATP production/oxygen consumption is low, leading to an increased production of superoxide anions. Reactive oxygen species formation may have maladaptive consequences that increase the rate of mutagenesis and stimulate proinflammatory processes. In addition to reactive oxygen species formation, genetic factors, aging, and reduced mitochondrial biogenesis all contribute to mitochondrial dysfunction. These factors also contribute to insulin resistance in classic and nonclassic insulin target tissues. Insulin resistance emanating from mitochondrial dysfunction may contribute to metabolic and cardiovascular abnormalities and subsequent increases in cardiovascular disease. Furthermore, interventions that improve mitochondrial function also improve insulin resistance. Collectively, these observations suggest that mitochondrial dysfunction may be a central cause of insulin resistance and associated complications. In this review, we discuss mechanisms of mitochondrial dysfunction related to the pathophysiology of insulin resistance in classic insulin-responsive tissue, as well as cardiovascular tissue.
The MAGS Water and Energy Budget Study
Authors: Szeto K. K. , Tran H. , MacKay M. D. , Crawford R. , Stewart R. E.
Published: February 2008

This study represents the first attempt at developing a comprehensive climatology of atmospheric and surface water and energy budgets for the Mackenzie River basin (MRB). Different observed, remotely sensed, (re)analyzed, and modeled datasets were used to obtain independent estimates of the budgets. In particular, assimilated datasets, including the National Centers for Environmental Prediction Global Reanalysis 2 (NCEP-R2), the global 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40), the NCEP North American Regional Reanalysis (NARR), and the Canadian Meteorological Centre (CMC) operational regional analysis as well as results from the Canadian Regional Climate Model (CRCM) simulations, are used in the study. Apart from the development of state-of-the-art budget estimates for the MRB, the relative merits of current models, data assimilation systems, and global blended datasets in representing aspects of the water and energy cycle of this northern and data-sparse region were also assessed. In addition, the levels of uncertainty in assessing the budgets as well as their sources are discussed. The regional water budget for the MRB is closed within 10% of the observed runoff by using the moisture flux convergence from ERA-40, NARR, CMC, or CRCM. While these are noted improvements over previous water closure assessments for the region, magnitudes of the residuals in balancing the budgets are often comparable to the budget terms themselves in all the model and analysis datasets, and the spreads of budget estimates from the different datasets are also typically large, suggesting that substantial improvements to the models and observations are needed before the assessments of water and energy budgets for this northern region can be vastly improved.
Evaluation of the Surface Radiation Budget in the Atmospheric Component of the Hadley Centre Global Environmental Model (HadGEM1)
Authors: Bodas-Salcedo A. , Ringer M. A. , Jones A.
Published: February 2008

The partitioning of the earth radiation budget (ERB) between its atmosphere and surface components is of crucial interest in climate studies as it has a significant role in the oceanic and atmospheric general circulation. An analysis of the present-day climate simulation of the surface radiation budget in the atmospheric component of the new Hadley Centre Global Environmental Model version 1 (HadGEM1) is presented, and the simulations are assessed by comparing the results with fluxes derived from satellite data from the International Satellite Cloud Climatology Project (ISCCP) and ground measurements from the Baseline Surface Radiation Network (BSRN).

Comparisons against radiative fluxes from satellite and ground observations show that the model tends to overestimate the surface incoming solar radiation (Ss,d). The model simulates Ss,d very well over the polar regions. Consistency in the comparisons against BSRN and ISCCP-FD suggests that the ISCCP-FD database is a good test for the performance of the surface downwelling solar radiation in climate model simulations. Overall, the simulation of downward longwave radiation is closer to observations than its shortwave counterpart. The model underestimates the downward longwave radiation with respect to BSRN measurements by 6.0 W m−2.

Comparisons of land surface albedo from the model and estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) show that HadGEM1 overestimates the land surface albedo over deserts and over midlatitude landmasses in the Northern Hemisphere in January. Analysis of the seasonal cycle of the land surface albedo in different regions shows that the amplitude and phase of the seasonal cycle are not well represented in the model, although a more extensive validation needs to be carried out.

Two decades of coupled model simulations of the twentieth-century climate are used to look into the model’s simulation of global dimming/brightening. The model results are in line with the conclusions of the studies that suggest that global dimming is far from being a uniform phenomenon across the globe.
Barotropic Zonal Jets Induced by Islands in the Southwest Pacific
Authors: Couvelard Xavier , Marchesiello Patrick , Gourdeau Lionel , Lefèvre Jerome
Published: February 2008

The oceanic circulation entering the tropical southwest Pacific (SWP) is dominated by the broad westward flow of the South Equatorial Current (SEC), which is forced by the trade winds. It has been argued that the numerous islands of the SWP are able to restructure the SEC into a series of deep and narrow zonal jets, which control important pathways connecting equatorial and extraequatorial signals. The primary objective of this paper is to improve the understanding of the structure and dynamics of SWP zonal jets, giving special attention to topographic effects. This study is based on the use of a high-resolution regional oceanic model, whose solution is compared with observations, as well as with solutions from global models and the Sverdrup relation. The model used here indicates that the regional topography drives a general equatorward shift of the SEC, which is beneficial to the North Fiji, North Vanuatu, and North Caledonian jets. A depth-integrated vorticity budget shows that this topographic effect is considerably attenuated by baroclinicity and advection processes, but not to the point of total compensation as often admitted for the interior ocean. The effect of nonlinear advection is to allow flow rectification of the jets fluctuations, taking the form of zonally elongated dipole circulations in the leeward side of the islands.
Kinematic and Moisture Characteristics of a Nonprecipitating Cold Front Observed during IHOP. Part II: Alongfront Structures
Authors: Friedrich Katja , Kingsmill David E. , Flamant Cyrille , Murphey Hanne V. , Wakimoto Roger M.
Published: February 2008

Kinematic and thermodynamic structures of a nonprecipitating cold front observed in west-central Kansas on 10 June 2002 during the International H2O Project (IHOP) are examined with dropsondes and airborne instrumentation that includes Doppler radars, a differential absorption lidar, and in situ sensors. Intensive observations were collected along a 125-km segment of the front, with coverage of both the cold front leading edge and the post- and prefrontal areas. Whereas the first part of this two-part series of papers focused on across-front kinematic and moisture characteristics, the study herein investigates alongfront structures relevant for convection initiation. A northeast–southwest-oriented cold front moved into the observational domain from the northwest, but its motion slowed to less than 1 m s−1 in the early afternoon. In the late afternoon it was intersected by a north-northeast–south-southwest-oriented reflectivity thin line that was advected from the southwest, and another boundary that is an extension of a large-scale dryline paralleling the thin line but located farther to the east. Doppler wind synthesis suggests an increase in low-level horizontal wind shear across the cold front leading edge with the approach and intersection of the boundaries causing an increase in low-level convergence (up to ∼1 × 10−3 s−1), positive vertical vorticity (up to ∼0.5 × 10−3 s−1), and upward motion (up to ∼1 m s−1). An organized pattern of misocyclones (vertical vorticity maxima <4 km) and enhanced updrafts with a spacing of ∼5–8 km were observed at the cold front leading edge. At the same time vortex lines manifested as horizontal vorticity maxima were observed within the cold air oriented perpendicular to the cold front leading edge and on top of the vertical wind shear layer. The analysis suggests that inflection point instability was the dominant mechanism for their development. Low Richardson number (0.3–0.4), short lifetime (<2 h), horizontal wavelength of 3–6 km, and collocation with strong horizontal and vertical wind shear are characteristics that support the hypothesis that these instabilities were Kelvin–Helmholtz waves. Towering cumulus developed along the cold front forming a convective cell close to the intersection of the cold front, dryline, and reflectivity thin line.
Life Events Associated With Major Depression in Ugandan Primary Healthcare (PHC) Patients: Issues of Cultural Specificity
Authors: Muhwezi Wilson Winstons , Ågren Hans , Neema Stella , Koma Maganda Albert , Musisi Seggane
Published: February 2008

Objective: The study compared life events experienced by depressed patients seen at primary healthcare (PHC) centres with those among healthy community controls.

Method: Data was collected from 74 depressed patients and 64 unmatched controls from village locales of patients. Interview instruments included the depression module of the Mini International Neuropsychiatric Interview (MINI) and Interview for Recent Life Events (IRLE). Associations between type of respondent and demographic variables were examined. Statistical comparisons were done for the two groups on other variables.

Results: Most depressed patients were single by marital status, lacked formal employment and had less post-primary education.They had experienced more life events; job changes, discomforting working hours, unfavourable working conditions, and job losses; personal health problems; loss of valuables; difficulties with intimate partners and family members' marital problems. Independent life events were more among depressed patients and clustered around work, health, bereavement and marriage. Most events reported by depressed patients had high negative impact ratings compared to controls.

Conclusion: Compared to healthy community controls, depressed patients reported more undesirable life events. The relationship between life events and depression implies that in PHC settings of poor countries, deploying mental health-oriented workers to manage life events may lessen escalation of distress.
Pharmacokinetic Interaction Between Tadalafil and Bosentan in Healthy Male Subjects
Authors: Wrishko Rebecca E. , Dingemanse Jasper , Yu Albert , Darstein Christelle , Phillips Diane L. , Mitchell Malcolm I.
Published: February 2008

Tadalafil, an oral phosphodiesterase 5 (PDE5) inhibitor, is being investigated as a treatment for pulmonary arterial hypertension. Bosentan is an oral endothelin receptor antagonist widely used in the treatment of pulmonary arterial hypertension. Tadalafil is mainly metabolized by cytochrome P450 (CYP) 3A4, and as bosentan induces CYP2C9 and CYP3A4, a pharmacokinetic interaction is possible between these agents. This open‐label, randomized study investigated whether any pharmacokinetic interaction exists between tadalafil and bosentan. Healthy adult men (n = 15; 19–52 years of age) received 10 consecutive days of tadalafil 40 mg once daily, bosentan 125 mg twice daily, and a combination of both in a 3‐period, crossover design. Following 10 days of multiple‐dose coadministration of bosentan and tadalafil, compared with tadalafil alone, tadalafil geometric mean ratios (90% confidence interval [CI]) for AUCτ and Cmax were 0.59 (0.55, 0.62) and 0.73 (0.68, 0.79), respectively, with no observed change in tmax. Following coadministration of bosentan with tadalafil, bosentan ratios (90% CI) for AUCτ and Cmax were 1.13 (1.02, 1.24) and 1.20 (1.05, 1.36), respectively. Tadalafil alone and combined with bosentan was generally well tolerated. In conclusion, after 10 days of coadministration, bosentan decreased tadalafil exposure by 41.5% with minimal and clinically irrelevant differences (<20%) in bosentan exposure.
On the Way to Theory: A Processual Approach
Authors: Nayak Ajit
Published: February 2008

Debates on theory have focused on the nature of good theories and the process of theorizing, but have failed to engage with the ontology of becoming emphasized by process philosophers such as Heraclitus, Bergson and James, and more recently by Cooper, Shotter and Chia. This paper argues that engaging with reality as becoming implies departing from any claims of `essence' in theories. Theories are not representations, better or worse, of a particular phenomenon, real or socially constructed. Instead, mobility, movement and creativity are the primordial qualities of theory. A becoming ontology also points to the non-sequential, imaginative and paradoxical `way' of theory-building. This paper argues that a processual approach which is reposed on introspective reality and the method of intuition is better suited to revealing a becoming reality.
Richard Kearney's hermeneutics of Otherness
Authors: Masterson Patrick
Published: February 2008

The article considers a particular case of Richard Kearney's characteristic hermeneutical exploration of `the possible' as an `imaginative' way of casting light upon philosophical issues. This particular case is his recent hermeneutical and phenomenological consideration of `Otherness' in the context of philosophy of religion. This consideration, strongly influenced by philosophers such as Heidegger, Levinas, Ricoeur and Derrida, is developed in two of his recent works Strangers, Gods and Monsters and The God Who May Be.

The article examines how he seeks to navigate an interpretation of divine otherness as an ethical appeal which escapes the dilemma of a God either so transcendent as to be anonymous or so immanent as to be a mere projection. It outlines how, rejecting onto-theology in favour of eschatology, Kearney envisages the divine as an ethically enabling possibility. This possibility, he claims, enables us to achieve, beyond our own intrinsic resources, an ethical order of justice and love through which the kingdom of God — the God Who May Be — is accomplished. There is a co-relativity between the divine as enabling possibility and humanity which accomplishes this possibility.

It investigates the way in which Kearney seeks to legitimize, within a phenomenological frame of reference, an experiential affirmation of this conception of divine transcendence as eschatological possibility. It argues that this phenomenological consideration needs to be qualified and complemented by certain metaphysical considerations which Kearney disputes.
Identifying concrete ethical demands in the face of the abstract other
Authors: Burns Lawrence
Published: February 2008

Critics of Levinas reject the notion that the abstract face of the other can ground ethics and generate specific responsibilities. To the contrary, I argue that the face does ground a practical and pragmatic ethics. Drawing on Levinas' phenomenological analyses of the enjoying subject, I show that the face communicates an imperative to the subject that obligates her or him to repair the concrete context of action in which the subject encounters the other. My elucidation takes very seriously the notion that the face speaks and the face is a body. When coupled with a pragmatic account of communication, Levinas gives us a robust elucidation of the phenomenological and pragmatic dimensions of ethical responsibility.
Summary and Implications for the Next Stage
Authors: Bargal David , Garvin Charles
Published: February 2008

This epilogue summarizes the articles presented earlier in this issue and indicates directions the project is likely to take in the future.