bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between insulin sensitivity and the triglyceride–HDL-C ratio in overweight and obese postmenopausal women: a MONET study
Authors: Karelis Antony D. , Pasternyk Stephanie M. , Messier Lyne , St-Pierre David H. , Lavoie Jean-Marc , Garrel Dominique , Rabasa-Lhoret Rémi
Published: November 2007

The objective of this cross-sectional study was to examine the relationship between the triglyceride–HDL-cholesterol ratio (TG:HDL-C) and insulin sensitivity in overweight and obese sedentary postmenopausal women. The study population consisted of 131 non-diabetic overweight and obese sedentary postmenopausal women (age; 57.7 ± 5.0 y; body mass index (BMI), 32.2 ± 4.3 kg/m2). Subjects were characterized by dividing the entire cohort into tertiles based on the TG:HDL-C (T1 < 0.86 vs. T2= 0.86 to 1.35 vs. T3 > 1.35, respectively). We measured (i) insulin sensitivity (using the hyperinsulinenic–euglycemic clamp and homeostasis model assessment (HOMA)), (ii) body composition (using dual-energy X-ray absorptiometry), (iii) visceral fat (using computed tomography), (iv) plasma lipids, C-reactive protein, 2 h glucose concentration during an oral glucose tolerance test (2 h glucose), as well as fasting glucose and insulin, (v) peak oxygen consumption, and (vi) lower-body muscle strength (using weight training equipment). Significant correlations were observed between the TG:HDL-C and the hyperinsulinemic–euglycemic clamp (r = –0.45; p < 0.0001), as well as with HOMA (r = 0.42; p < 0.0001). Moreover, the TG:HDL-C significantly correlated with lean body mass, visceral fat, 2 h glucose, C-reactive protein, and muscle strength. Stepwise regression analysis showed that the TG:HDL-C explained 16.4% of the variation in glucose disposal in our cohort, which accounted for the greatest source of unique variance. Other independent predictors of glucose disposal were 2 h glucose (10.1%), C-reactive protein (CRP; 7.6%), and peak oxygen consumption (5.8%), collectively (including the TG:HDL-C) explaining 39.9% of the unique variance. In addition, the TG:HDL-C was the second predictor for HOMA, accounting for 11.7% of the variation. High levels of insulin sensitivity were associated with low levels of the TG:HDL-C. In addition, the TG:HDL-C was a predictor for glucose disposal rates and HOMA values in our cohort of overweight and obese postmenopausal women.
New oral fat tolerance tests feature tailoring of the polyunsaturated/saturated fatty acid ratio to elicit a specific postprandial response
Authors: Dekker Mark J. , Wright Amanda J. , Mazurak Vera C. , Graham Terry E. , Marangoni Alejandro G. , Robinson Lindsay E.
Published: November 2007

The impact of dietary fat on postprandial metabolic biomarkers for obesity-related chronic diseases, such as type-2 diabetes and cardiovascular disease, has received significant recent attention. However, there is no standard method to evaluate the postprandial response to dietary fat alone. Our goals were to develop a novel oral fat tolerance test (OFTT) consisting solely of emulsified lipids tailored for specific fatty acid compositions and to evaluate the functionality of specific ratios of polyunsaturated/saturated fatty acid (P/S) loading on postprandial triacylglyceride (TAG) concentrations. Two OFTTs of emulsified lipids were prepared with specific P/S ratios of 0.2 and 2.0. Physical characteristics of the fat blends, including TAG composition, melting point, and emulsion droplet size were quantified. Healthy, older (age > 45 y) men (n = 8) underwent an 8 h postprandial study wherein they received the OFTT treatment (either the P/S ratio of 0.2 or 2.0), with a total lipid load of 1 g/kg subject body mass. All subjects received both treatments separated by at least 1 week. Both the P/S 0.2 and 2.0 OFTT significantly elevated (p < 0.05) blood TAG and free fatty acid concentrations for 8 h without increasing blood glucose or serum insulin concentrations. The predominant fatty acids contained in the P/S 0.2 (palmitic acid, 16:0) and 2.0 (linoleic acid, 18:2(n–6)) OFTT blends were significantly elevated in the blood (p < 0.05) during their respective postprandial periods. We concluded that blood TAGs are elevated in a specific pattern through the administration of novel OFTTs with specific P/S blends without eliciting an insulin or glucose response.
Rat hindlimb unloading down-regulates insulin like growth factor-1 signaling and AMP-activated protein kinase, and leads to severe atrophy of the soleus muscle
Authors: Han Bing , Zhu Mei J. , Ma Changwei , Du Min
Published: November 2007

Inactivity is known to induce muscle atrophy, which is associated with insulin and insulin-like growth factor-1 (IGF-1) resistance, but the associated mechanisms remain poorly defined. The hindlimb unloading model has been used to reduce muscle activity. The objective of this study was to show the effect of hindlimb unloading on IGF-1 signaling and AMP-activated protein kinase (AMPK) activity in rat soleus and extensor digitorum longus (EDL) muscles. Twelve 7-week-old male Sprague–Dawley rats were assigned to 2 treatments: (i) rats without hindlimb unloading (Con) and (ii) rats with hindlimb unloading (Unload). After 2 weeks of treatment, the soleus and EDL muscles were dissected and used for biochemical analyses. Hindlimb unloading induced severe muscle atrophy in soleus muscle (0.122 ± 0.007 g for Con vs. 0.031 ± 0.004 g for Unload, p < 0.01), but only slight atrophy in EDL muscle. The phosphorylation of AMPK (p < 0.05) and its downstream substrate, acetyl-CoA carboxylase (ACC) (p < 0.01) were reduced in soleus muscle due to unloading. The concentration of insulin receptor substrate-1 (IRS-1) and phosphorylation of IRS-1 at Ser636–639and Ser789were also reduced. Downstream IGF-1 signaling was downregulated in Unload rats. A reduction in IGF-1 concentration in unloaded soleus muscle was also observed. A slight reduction in AMPK activity and IGF-1 signaling were observed in EDL muscle. Since AMPK controls the sensitivity of IGF-1 signaling through phosphorylation at Ser789, the reduction in AMPK activity is expected to reduce the response of downstream IGF-1 signaling to IGF-1; this, in combination with reduced IGF-1 concentration, might be responsible for the severe muscle atrophy observed in unloaded soleus muscle.
Physical activity and inactivity profiling: the next generationThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Esliger Dale W. , Tremblay Mark S.
Published: November 2007

The accurate measurement of habitual physical activity is fundamental to the study of the relationship between physical activity and health. However, many physical activity measurement techniques produce variables accurate to only the day level, such as total energy expenditure via self-report questionnaire, pedometer step counts, or accelerometer measurements of minutes of moderate to vigorous physical activity. Monitoring technologies providing more detailed information on physical activity and inactivity behaviour can now be used to explore the relationships between health and movement frequency, intensity, and duration more comprehensively. This paper explores the activity–inactivity profile that can be acquired through objective monitoring, with a focus on accelerometry. Using previously collected objective data, a detailed physical activity profile is presented and case study examples of data utilization and interpretation are provided. The rich detail captured through comprehensive profiling creates new surveillance and study possibilities and could possibly inform new physical activity guidelines. Data are presented in various formats to demonstrate the dangers of misinterpretation when monitoring population adherence to Canada’s physical activity guidelines. Recommendations for physical activity–inactivity profiling are provided and future research needs identified.
Considerations for the development of a physical activity guide for Canadians with physical disabilitiesThis article is part of a supplement entitledAdvancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelinesco-published byApplied Physiology, Nutrition, and Metabolismand theCanadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Martin Ginis Kathleen A. , Hicks Audrey L.
Published: November 2007

This paper provides a brief overview of the epidemiological data regarding Canadians with physical disabilities, with a particular emphasis on health status. A literature review is then presented, focusing on activity levels and the physiological and health-related quality of life benefits of activity for people with four different physical disabilities (arthritis, fibromyalgia, spinal cord injury, and multiple sclerosis). The unique physical activity barriers faced by people with physical disabilities are discussed. The paper concludes with recommendations for the development of a physical activity guide for Canadians with physical disabilities.
Physical activity of Aboriginal people in CanadaThis article is part of a supplement entitledAdvancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelinesco-published byApplied Physiology, Nutrition, and Metabolismand theCanadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Young T. Kue , Katzmarzyk Peter T.
Published: November 2007

This paper summarizes available information on patterns of physical activity, their determinants and consequences, and the results of various interventions designed to increase the physical activity of Aboriginal peoples in Canada and the United States. There is a paucity of national data on this issue for Aboriginal peoples. The most recent data, from the First Nations Regional Longitudinal Health Survey of 2002–2003, indicate that 21% of adults (27% of men, 15% of women) were engaging in at least 30 min of moderate to vigorous physical activity on 4 d/week or more. The present paper highlights the unique challenges this group faces, underlining the need to integrate collective knowledge regarding how much physical activity is required for Aboriginal Canadians, and how this activity should be accomplished, to promote and maintain health. Efforts are currently underway to tailor Canada’s physical activity guide for First Nations, Inuit, and Métis. Future research among Aboriginal groups should examine the minimal and optimal levels of physical activity required to achieve health benefits.
Effects of ageing on muscle O2 utilization and muscle oxygenation during the transition to moderate-intensity exercise
Authors: DeLorey Darren S. , Paterson Donald H. , Kowalchuk John M.
Published: November 2007

At the onset of exercise, an increase in muscle and pulmonary O2 consumption is met by increases in muscle O2 delivery and muscle O2 extraction. Thus, the study of pulmonary O2 uptake kinetics reflects the integrated response between the convective and diffusive O2 delivery systems and the muscle metabolic machinery (i.e., mitochondrial enzyme activation and provision of acetyl groups to the tricarboxcylic acid cycle) to increase muscle O2 consumption. Pulmonary O2 uptake kinetics are slowed in older adults compared with young adults and previous studies suggest that the slower O2 uptake kinetics may be the result of an age-associated decline in the ability of older adults to increase O2 delivery to active muscles. However, an inherent limitation to understanding the control of and limitations to pulmonary O2 uptake kinetics is that it is methodologically difficult to examine the adaptation of muscle perfusion and O2 delivery and muscle O2 utilization in the muscle microcirculation of active muscles in the dynamically exercising human. In this review, we provide an overview of the effect of ageing on pulmonary O2 uptake kinetics (reflecting the activation of muscle O2 consumption) during the transition to moderate-intensity exercise. Age-related changes in O2 delivery systems and muscle oxidative capacity are examined as potential limitations to pulmonary O2 uptake kinetics. We then review recent studies from our laboratory that have investigated the control of pulmonary O2 uptake kinetics at the level of the muscle microcirculation by examining the adaptation of muscle O2 delivery and muscle O2 utilization using near-infrared spectroscopy during the transition to exercise in healthy young and older adults.
Canada’s physical activity guides: background, process, and developmentThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2).
Authors: Sharratt Michael T. , Hearst William E.
Published: November 2007

This historical background paper chronicles the major events leading to the development of Canada’s physical activity guides (for children, youth, adults, and older adults). The paper outlines the process and the steps used, including information (where applicable) regarding national partners, project administration, Health Canada communications, product development, endorsement, distribution and implementation, collateral activities, media relations and evaluation framework. Brief summaries of the science that led to the recommended guidelines are included. The paper also summarizes the various physical activity guide assessment and evaluation projects and their findings, particularly as they relate to research carried out on Canada’s physical activity guides for children and youth (and the associated support resources).
(R)-1-Phenylethylamine as chiral auxiliary in the diastereoselective synthesis of tetrahydro-β-carboline derivatives
Authors: Siwicka Aleksandra , Wojtasiewicz Krystyna , Leniewski Andrzej , Maurin Jan K , Zawadzka Anna , Czarnocki Zbigniew
Published: November 2007

Modified sodium borohydrides were used in the reduction of the imine moiety in compounds containing the (R)-1-arylethylamine motif as a chiral auxiliary. Diastereomeric products were formed with moderate to good stereoselectivity and were effectively separated by column chromatography.Key words: asymmetric synthesis, indole alkaloids, hydrogen bond.
Structural finding of R/S-3,4-dihydro-2,2-dimethyl-6-halo-4-(substituted phenylaminocarbonylamino)-2H-1-benzopyrans as selective pancreatic β-cells KATP-pβ channel openers
Authors: Alam Sk. Mahasin , Samanta Soma , Halder Amit Kumar , Basu Soumya , Jha Tarun
Published: November 2007

R/S-3,4-Dihydro-2,2-dimethyl-6-halo-4-(substituted phenylaminocarbonyl-amino)-2H-1-benzopyrans are pancreatic β-cells potassium (KATP-pβ) channel openers with inhibitory effect on insulin secretion. To find the more active and effective benzopyrans as selective potassium (KATP-pβ) channel openers towards the pancreatic tissues, quantitative structure–activity relationships (QSAR) study was performed using E-state and R-state indices along with Wang–Ford charges, n-octanol/water partition coefficient, molar refractivity, and indicator parameters. QSAR models were developed by statistical techniques, e.g., multiple linear regression (MLR), principle component regression analysis (PCRA), and partial least squares (PLS) analysis. The generated equations were validated by the leave-one-out cross-validation method. The models show the importance of ETSA indices of atom numbers 16, 17, 18, 19, 21 as well as 22. The positive coefficient of S16, S17, S18, S19, S21, and S22 indicate that with the increase of the value of E-state indices, desired activity decreases. RTSA index is also important for the biological activity, and the atom numbers 16, 17, 18, 19, 20 and 22 are involved in van der Waals interactions. RTSA index also possesses negative impact on the inhibition of residual insulin secretion. Wang–Ford charges of some particular atoms are also important for the inhibition. Increase of n-octanol/water partition coefficients of compounds inhibit insulin secretion, and the presence of chlorine atom at m- and p- positions of the phenyl ring B is necessary for the inhibition of residual insulin secretion.Key words: benzopyran derivatives, potassium channel openers, PCRA, PLS, QSAR.
GLOBAL CONSISTENCY OF DECISIONS AND CONVERGENCE OF COMPETITIVE CELLULAR NEURAL NETWORKS
Authors: DI MARCO M. , FORTI M. , GRAZZINI M. , NISTRI P. , PANCIONI L.
Published: November 2007

In a series of papers published in the seventies, Grossberg had developed a geometric approach for analyzing the global dynamical behavior and convergence properties of a class of competitive dynamical systems. The approach is based on the property that it is possible to associate a decision scheme with each competitive system in that class, and that global consistency of the decision scheme implies convergence of each solution toward some stationary state. In this paper, the Grossberg approach is extended to the class of competitive standard Cellular Neural Networks (CNNs), and it is used to investigate convergence under the hypothesis that the competitive CNN has a globally consistent decision scheme. The extension is nonobvious and requires to deal with the set-valued vector field describing the dynamics of the CNN output solutions. It is also stressed that the extended approach does not require the existence of a Lyapunov function, hence it is applicable to address convergence in the general case where the CNN neuron interconnections are not necessarily symmetric. By means of the extended approach, a number of classes of third-order nonsymmetric competitive CNNs are discovered, which have a globally consistent decision scheme and are convergent. Moreover, global consistency and convergence hold for interconnection parameters belonging to sets with non-empty interior, and thus they represent physically robust properties. The paper also shows that when the dimension is higher than three, there are fundamental differences between the convergence properties of competitive CNNs implied by a globally consistent decision scheme, and those of the class of competitive dynamical systems considered by Grossberg. These differences lead to the need to introduce a stronger notion of global consistency of decisions, with respect to that proposed by Grossberg, in order to guarantee convergence of competitive CNNs with more than three neurons.
EXPERIMENTAL RESULTS ON CHUA'S CIRCUIT ROBUST SYNCHRONIZATION VIA LMIs
Authors: CAMPOS C. D. , PALHARES R. M. , MENDES E. M. A. M. , TORRES L. A. B. , MOZELLI L. A.
Published: November 2007

This paper investigates the synchronization of coupled chaotic systems using techniques from the theory of robust [Formula: see text] control based on Linear Matrix Inequalities. To deal with the synchronization of a class of Lur'e discrete time systems, a project methodology is proposed. A laboratory setup based on Chua's oscillator circuit is used to demonstrate the main ideas of the paper in the context of the problem of information transmission.
DYNAMIC TRANSMURALITY: CARDIAC OPTICAL MAPPING REVEALS WAVES TRAVEL ACROSS TRANSMURAL ABLATION LINES
Authors: SIMONOTTO JENNIFER D. , FURMAN MICHAEL D. , DITTO WILLIAM L. , MILIOTIS ABRAHAM , SPANO MARK L. , BEAVER THOMAS M.
Published: November 2007

Cardiac ablation is increasingly used to interdict the complex propagation of excitatory waves during atrial fibrillation. While such procedures are useful, they can often fail. Here we use fluorescence imaging to observe the electrical activity of an ablated porcine heart. We find that, while ablation lines do attenuate cardiac waves, the attenuation is incomplete. A remnant of the incident wave survives passage through the ablation barrier, albeit as a subthreshold signal. More importantly, we have found that these subthreshold signals may add constructively and thereby dynamically reduce the effective attenuation, an effect which we call "dynamic transmurality". We suspect this as a factor in the persistence of arrhythmia after ablative.
A NONLINEAR DYNAMICS PERSPECTIVE OF WOLFRAM'S NEW KIND OF SCIENCE PART VII: ISLES OF EDEN
Authors: CHUA LEON O. , GUAN JUNBIAO , SBITNEV VALERY I. , SHIN JINWOOK
Published: November 2007

This paper continues our quest to develop a rigorous analytical theory of 1-D cellular automata via a nonlinear dynamics perspective. The 18 yet uncharacterized local rules are henceforth partitioned into ten complex Bernoulliστ-shift rules and eight hyper Bernoulliστ-shift rules, the latter including such famous rules [Formula: see text] and [Formula: see text]. All exhibit a bizarre composite wave dynamics with arbitrarily large Bernoulli velocity σ and Bernoulli return time τ as the length L → ∞.

Basin tree diagrams of all ten complex Bernoulli στ-shift rules are exhibited for lengths L = 3, 4, …, 8. Superficial as it may seem, these basin tree diagrams suggest general qualitative properties which have since been proved to be true in general. Two such properties form the main results of this paper; namely, [Formula: see text]

Explicit global state transition formulas are given for local rules [Formula: see text], [Formula: see text] and [Formula: see text]. Such formulas led to the rigorous proof of several surprising periodicity constraints for rule [Formula: see text], and to the discovery of a new global, quasi-equivalence class, defined via an alternating transformation. In particular, local rules [Formula: see text] and [Formula: see text]are globally quasi-equivalent where corresponding space-time patterns can be derived from each other by simply complementing every other row.

Another important result of this paper is the discovery of a scale-free phenomenon exhibited by the local rules [Formula: see text], [Formula: see text] and [Formula: see text]. In particular, the period "T" of all attractors of rules [Formula: see text], [Formula: see text] and [Formula: see text], as well as of all isles of Eden of rules [Formula: see text] and [Formula: see text], increases linearly with unit slope, in logarithmic scale, with the length L.
THE COMPETITION BETWEEN INCOMING AND OUTGOING FLUXES IN AN ELLIPTIC PROBLEM
Authors: GARCÍA-MELIÁN JORGE , ROSSI JULIO D. , SUÁREZ ANTONIO
Published: November 2007

In this work, we consider existence and uniqueness of positive solutions to the elliptic equation -Δu = λu in Ω, with the nonlinear boundary conditions [Formula: see text] on Γ1, [Formula: see text] on Γ2, where Ω is a smooth bounded domain, ∂Ω = Γ1 ∪ Γ2, [Formula: see text], ν is the outward unit normal, p, q > 0 and λ is a real parameter. We obtain a complete picture of the bifurcation diagram of the problem, depending on the values of p, q and the parameter λ. Our proofs are based on different techniques: variational arguments, bifurcation techniques or comparison arguments, depending on the range of parameters considered.
THE MODULI SPACE OF N = 2 SUPER-RIEMANN SPHERES WITH TUBES
Authors: BARRON KATRINA
Published: November 2007

Within the framework of complex supergeometry and motivated by two-dimensional genus-zero holomorphic N = 2 superconformal field theory, we define the moduli space of N = 2 super-Riemann spheres with oriented and ordered half-infinite tubes (or equivalently, oriented and ordered punctures, and local superconformal coordinates vanishing at the punctures), modulo N = 2 superconformal equivalence. We develop a formal theory of infinitesimal N = 2 superconformal transformations based on a representation of the N = 2 Neveu–Schwarz algebra in terms of superderivations. In particular, via these infinitesimals we present the Lie supergroup of N = 2 superprojective transformations of the N = 2 super-Riemann sphere. We give a reformulation of the moduli space in terms of these infinitesimals. We introduce generalized N = 2 super-Riemann spheres with tubes and discuss some group structures associated to certain moduli spaces of both generalized and non-generalized N = 2 super-Riemann spheres. We define an action of the symmetric groups on the moduli space. Lastly we discuss the nonhomogeneous (versus homogeneous) coordinate system associated to N = 2 superconformal structures and the corresponding results in this coordinate system.
A NOVEL DECISION FUSION METHOD BASED ON MULTI-SENSOR BEHAVIOR AND ITS APPLICATION FOR NETWORKED TARGET IDENTIFICATION
Authors: RASHIDI ALI J.
Published: November 2007

In this paper, we would focus on submitting a new decision fusion method based on multiple sensors' behaviors applying to target detection and identification in a network of distributed sensors. Each sensor has its own reliability, error rate and output data. Hence, in a processing and decision-making center in which target data are received from different sensors and sources, correctness and speed of final decision-making depend on data fusion method. The extraction, modeling and weighing of long-time and temporary behavior functions of each data source and using precise and fast decision making/fusion method are the main purpose of this article. After the introduction, we try to consider the data fusion method in decision level, such as voting schemes, rank based method and Bayesian inference. Hence, in a distributed target detection and identification system, we explain the specific and the functional features model of each source using long-time and temporary behavior functions. So we introduce the behavior based method as a new decision fusion method based on long-time and temporary behaviors of local decision makers. Therefore, we will observe that the behavior based method results, which pointed both to the temporal and the long time behaviors of the input decision makings, are very much nearer to reality and its correctness in target identification is much higher than the other methods. Examples are given corresponding to the target detection and identification systems to compare the new method with the other methods are shown that the behavior based method has its own exclusive capability in target detection, identification and producing final decision without ambiguity.
Perceptual rendering of participating media
Authors: Sundstedt Veronica , Gutierrez Diego , Anson Oscar , Banterle Francesco , Chalmers Alan
Published: November 2007

High-fidelity image synthesis is the process of computing images that are perceptually indistinguishable from the real world they are attempting to portray. Such a level of fidelity requires that the physical processes of materials and the behavior of light are accurately simulated. Most computer graphics algorithms assume that light passes freely between surfaces within an environment. However, in many applications, we also need to take into account how the light interacts with media, such as dust, smoke, fog, etc., between the surfaces. The computational requirements for calculating the interaction of light with such participating media are substantial. This process can take many hours and rendering effort is often spent on computing parts of the scene that may not be perceived by the viewer. In this paper, we present a novel perceptual strategy for physically based rendering of participating media. By using a combination of a saliency map with our new extinction map (X map), we can significantly reduce rendering times for inhomogeneous media. The visual quality of the resulting images is validated using two objective difference metrics and a subjective psychophysical experiment. Although the average pixel errors of these metric are all less than 1%, the subjective validation indicates that the degradation in quality still is noticeable for certain scenes. We thus introduce and validate a novel light map (L map) that accounts for salient features caused by multiple light scattering around light sources.
Algorithms for power savings
Authors: Irani Sandy , Shukla Sandeep , Gupta Rajesh
Published: November 2007

This article examines two different mechanisms for saving power in battery-operated embedded systems. The first strategy is that the system can be placed in a sleep state if it is idle. However, a fixed amount of energy is required to bring the system back into an active state in which it can resume work. The second way in which power savings can be achieved is by varying the speed at which jobs are run. We utilize a power consumption curve
P
(
s
) which indicates the power consumption level given a particular speed. We assume that
P
(
s
) is convex, nondecreasing, and nonnegative for
s
≥ 0. The problem is to schedule arriving jobs in a way that minimizes total energy use and so that each job is completed after its release time and before its deadline. We assume that all jobs can be preempted and resumed at no cost. Although each problem has been considered separately, this is the first theoretical analysis of systems that can use both mechanisms. We give an offline algorithm that is within a factor of 2 of the optimal algorithm. We also give an online algorithm with a constant competitive ratio.
Partial fillup and search time in LC tries
Authors: Janson Svante , Szpankowski Wojciech
Published: November 2007

Andersson and Nilsson introduced in 1993 a
level-compressed trie
(for short, LC trie) in which a full subtree of a node is compressed to a single node of degree being the size of the subtree. Recent experimental results indicated a “dramatic improvement” when full subtrees are replaced by “partially filled subtrees.” In this article, we provide a theoretical justification of these experimental results, showing, among others, a rather moderate improvement in search time over the original LC tries. For such an analysis, we assume that
n
strings are generated independently by a binary memoryless source, with
p
denoting the probability of emitting a “1” (and
q
= 1 −
p
). We first prove that the so-called α-fillup level
F

n

(α) (i.e., the largest level in a trie with α fraction of nodes present at this level) is concentrated on two values with high probability: either
F

n

(α) =
k

n

or
F

n

(α) =
k

n

+ 1, where
k

n

= log

1/√
pq

n
− |ln (
p/q
)|/2 ln
3/2
(1√
pq
) Φ
−1
(α) √ ln
n
+
O
(1) is an integer and Φ(
x
) denotes the normal distribution function. This result directly yields the typical depth (search time)
D

n

(α) in the α-LC tries, namely, we show that with high probability
D

n

(α) ∼
C
2
log log
n
, where
C
2
= 1/|log(1 −
h
/log(1/√
pq
))| for
p
≠
q
and
h
= −
p
log
p
−
q
log
q
is the Shannon entropy rate. This should be compared with recently found typical depth in the original LC tries, which is
C
1
log log
n
, where
C
1
= 1/|log(1−
h
/log(1/min{
p
, 1−
p
}))|. In conclusion, we observe that α affects only the lower term of the α-fillup level
F

n

(α), and the search time in α-LC tries is of the same order as in the original LC tries.
Approximation algorithms and hardness results for cycle packing problems
Authors: Krivelevich Michael , Nutov Zeev , Salavatipour Mohammad R. , Verstraete Jacques , Yuster Raphael
Published: November 2007

The
cycle packing number
ν

e

(
G
) of a graph
G
is the maximum number of pairwise edge-disjoint cycles in
G
. Computing ν

e

(
G
) is an NP-hard problem. We present approximation algorithms for computing ν

e

(
G
) in both undirected and directed graphs. In the undirected case we analyze a variant of the modified greedy algorithm suggested by Caprara et al. [2003] and show that it has approximation ratio Θ(√log
n
), where
n
= |
V
(
G
)|. This improves upon the previous
O
(log
n
) upper bound for the approximation ratio of this algorithm. In the directed case we present a √
n
-approximation algorithm. Finally, we give an
O
(
n
2/3
)-approximation algorithm for the problem of finding a maximum number of edge-disjoint cycles that intersect a specified subset
S
of vertices. We also study generalizations of these problems. Our approximation ratios are the currently best-known ones and, in addition, provide upper bounds on the
integrality gap
of standard LP-relaxations of these problems. In addition, we give lower bounds for the integrality gap and approximability of ν

e

(
G
) in directed graphs. Specifically, we prove a lower bound of Ω(log
n
/loglog
n
) for the integrality gap of edge-disjoint cycle packing. We also show that it is quasi-NP-hard to approximate ν

e

(
G
) within a factor of
O
(log
1
− ε
n
) for any constant ε > 0. This improves upon the previously known APX-hardness result for this problem.
An adaptive packed-memory array
Authors: Bender Michael A. , Hu Haodong
Published: November 2007

The
packed-memory array
(
PMA
) is a data structure that maintains a dynamic set of
N
elements in sorted order in a Θ(
N
)-sized array. The idea is to intersperse Θ(
N
) empty spaces or
gaps
among the elements so that only a small number of elements need to be shifted around on an insert or delete. Because the elements are stored physically in sorted order in memory or on disk, the PMA can be used to support extremely efficient range queries. Specifically, the cost to scan
L
consecutive elements is
O
(1 +
L
/
B
) memory transfers.

This article gives the first
adaptive packed-memory array
(
APMA
), which automatically adjusts to the input pattern. Like the traditional PMA, any pattern of updates costs only
O
(log
2
N
) amortized element moves and
O
(1 + (log
2
N
)/
B
) amortized memory transfers per update. However, the APMA performs even better on many common input distributions achieving only
O
(log
N
) amortized element moves and
O
(1+ (log
N
)/
B
) amortized memory transfers. The article analyzes
sequential
inserts, where the insertions are to the front of the APMA,
hammer
inserts, where the insertions “hammer” on one part of the APMA,
random
inserts, where the insertions are after random elements in the APMA, and
bulk
inserts, where for constant α ϵ [0, 1],
N
α
elements are inserted after random elements in the APMA. The article then gives simulation results that are consistent with the asymptotic bounds. For sequential insertions of roughly 1.4 million elements, the APMA has four times fewer element moves per insertion than the traditional PMA and running times that are more than seven times faster.
Unified framework for fast exact and approximate search in dissimilarity spaces
Authors: Skopal Tomáš
Published: November 2007

In multimedia systems we usually need to retrieve database (DB) objects based on their similarity to a query object, while the similarity assessment is provided by a measure which defines a (dis)similarity score for every pair of DB objects. In most existing applications, the similarity measure is required to be a metric, where the triangle inequality is utilized to speed up the search for relevant objects by use of metric access methods (MAMs), for example, the M-tree. A recent research has shown, however, that nonmetric measures are more appropriate for similarity modeling due to their robustness and ease to model a made-to-measure similarity. Unfortunately, due to the lack of triangle inequality, the nonmetric measures cannot be directly utilized by MAMs. From another point of view, some sophisticated similarity measures could be available in a black-box nonanalytic form (e.g., as an algorithm or even a hardware device), where no information about their topological properties is provided, so we have to consider them as nonmetric measures as well. From yet another point of view, the concept of similarity measuring itself is inherently imprecise and we often prefer fast but approximate retrieval over an exact but slower one.

To date, the mentioned aspects of similarity retrieval have been solved separately, that is,
exact versus approximate
search or
metric versus nonmetric
search. In this article we introduce a similarity retrieval framework which incorporates both of the aspects into a single unified model. Based on the framework, we show that for any dissimilarity measure (either a metric or nonmetric) we are able to change the “amount” of triangle inequality, and so obtain an approximate or full metric which can be used for MAM-based retrieval. Due to the varying “amount” of triangle inequality, the measure is modified in a way suitable for either an exact but slower or an approximate but faster retrieval. Additionally, we introduce the
TriGen algorithm
aimed at constructing the desired modification of any black-box distance automatically, using just a small fraction of the database.
NaLIX
Authors: Li Yunyao , Yang Huahai , Jagadish H. V.
Published: November 2007

We describe the construction of a generic natural language query interface to an XML database. Our interface can accept a large class of English sentences as a query, which can be quite complex and include aggregation, nesting, and value joins, among other things. This query is translated, potentially after reformulation, into an XQuery expression. The translation is based on mapping grammatical proximity of natural language parsed tokens in the parse tree of the query sentence to proximity of corresponding elements in the XML data to be retrieved. Iterative search in the form of followup queries is also supported. Our experimental assessment, through a user study, demonstrates that this type of natural language interface is good enough to be usable now, with no restrictions on the application domain.
A semantic approach to approximate service retrieval
Authors: Toch Eran , Gal Avigdor , Reinhartz-Berger Iris , Dori Dov
Published: November 2007

Web service discovery is one of the main applications of semantic Web services, which extend standard Web services with semantic annotations. Current discovery solutions were developed in the context of automatic service composition. Thus, the “client” of the discovery procedure is an automated computer program rather than a human, with little, if any, tolerance to inexact results. However, in the real world, services which might be semantically distanced from each other are glued together using manual coding. In this article, we propose a new retrieval model for semantic Web services, with the objective of simplifying service discovery for human users. The model relies on simple and extensible keyword-based query language and enables efficient retrieval of approximate results, including approximate service compositions. Since representing all possible compositions and all approximate concept references can result in an exponentially-sized index, we investigate clustering methods to provide a scalable mechanism for service indexing. Results of experiments, designed to evaluate our indexing and query methods, show that satisfactory approximate search is feasible with efficient processing time.
Model-driven design and development of semantic Web service applications
Authors: Brambilla Marco , Ceri Stefano , Facca Federico Michele , Celino Irene , Cerizza Dario , Valle Emanuele Della
Published: November 2007

This article proposes a model-driven methodology to design and develop semantic Web service applications and their components, described according to the emerging WSMO standard. In particular, we show that business processes and Web engineering models have sufficient expressive power to support the semiautomatic extraction of semantic descriptions (i.e., WSMO ontologies, goals, Web services, and mediators), thus partially hiding the complexity of dealing with semantics. Our method is based on existing models for the specification of business processes (BPMN) combined with Web engineering models for designing and developing semantically rich Web applications (WebML). The proposed approach leads from an abstract view of the business needs to a concrete implementation of the application by means of several design steps; high-level models are transformed into software components. Our framework increases the efficiency of the whole design process, yielding to the construction of semantic Web service applications spanning over several enterprises.
Automated design of pin-constrained digital microfluidic biochips under droplet-interference constraints
Authors: Xu Tao , Hwang William L. , Su Fei , Chakrabarty Krishnendu
Published: November 2007

Microfluidics-based biochips, also referred to as lab-on-a-chip, are devices that integrate fluid-handling functions such as sample preparation, analysis, separation, and detection. This emerging technology combines electronics with biology to open new application areas such as point-of-care diagnosis, on-chip DNA analysis, and automated drug discovery. We propose a design automation method for pin-constrained biochips that manipulate nanoliter volumes of discrete droplets on a microfluidic array. In contrast to the direct-addressing scheme that has been studied thus far in the literature, we assign a small number of independent control pins to a large number of electrodes in the biochip, thereby reducing design complexity and product cost. The design procedure relies on a droplet-trace-based array partitioning scheme and an efficient pin assignment technique, referred to as the “Connect-5 algorithm.” The proposed method is evaluated using a set of multiplexed bioassays.
Creativity support tools: accelerating discovery and innovation
Authors: Shneiderman Ben
Published: November 2007

How can designers of programming interfaces, interactive tools, and rich social environments enable more people to be more creative more often?
Multidisciplinary research on the datapath of the computing disciplines
Authors: Lopez Antonio M. , Lopez Frederick G. , Lent Robert W. , Constantine Madonna G.
Published: November 2007

Social cognitive career theory helps determine why minorities and women are still so underrepresented in the computing disciplines in colleges and universities.
Counting the cost of virtual teams
Authors: Pillis Emmeline de , Furumo Kimberly
Published: November 2007

Studying the performance, satisfaction, and group dynamics of virtual and face-to-face teams.
Training future software developers to acquire agile development skills
Authors: Tan Chuan-Hoo , Teo Hock-Hai
Published: November 2007

Giving students experience developing and delivering large-scale systems under time constraints and shifting deadlines.
The effect of intermittent hypobaric hypoxic exposure and sea level training on submaximal economy in well-trained swimmers and runners
Authors: Truijens Martin J. , Rodríguez Ferran A. , Townsend Nathan E. , Stray-Gundersen James , Gore Christopher J. , Levine Benjamin D.
Published: November 2007

To evaluate the effect of intermittent hypobaric hypoxia combined with sea level training on exercise economy, 23 well-trained athletes (13 swimmers, 10 runners) were assigned to either hypobaric hypoxia (simulated altitude of 4,000–5,500 m) or normobaric normoxia (0–500 m) in a randomized, double-blind design. Both groups rested in a hypobaric chamber 3 h/day, 5 days/wk for 4 wk. Submaximal economy was measured twice before (Pre) and after (Post) the treatment period using sport-specific protocols. Economy was estimated both from the relationship between oxygen uptake (V̇o2) and speed, and from the absolute V̇o2at each speed using sport-specific protocols. V̇o2was measured during the last 60 s of each (3–4 min) stage using Douglas bags. Ventilation (V̇e), heart rate (HR), and capillary lactate concentration ([La−]) were measured during each stage. Velocity at maximal V̇o2(velocity at v̇o2max) was used as a functional indicator of changes in economy. The average V̇o2for a given speed of the Pre values was used for Post test comparison using a two-way, repeated-measures ANOVA. Typical error of measurement of V̇o2was 4.7% (95% confidence limits 3.6–7.1), 3.6% (2.8–5.4), and 4.2% (3.2–6.9) for speeds 1, 2, and 3, respectively. There was no change in economy within or between groups (ANOVA interaction P = 0.28, P = 0.23, and P = 0.93 for speeds 1, 2, and 3). No differences in submaximal HR, [La−], V̇e, or velocity at V̇o2maxwere found between groups. It is concluded that 4 wk of intermittent hypobaric hypoxia did not improve submaximal economy in this group of well-trained athletes.
Augmented Ototoxic Effect of Cisplatin in Heterozygotes of the German Waltzing Guinea Pig
Authors: Skjönsberg Åsa , Bucinskaite Violeta , Laurell Göran , Ulfendahl Mats
Published: November 2007

It has previously been demonstrated that the carriers of the German waltzing guinea pig are less susceptible to noise trauma. To explore whether this represents a general resistance to inner ear trauma, carriers of the German waltzing guinea pig were exposed to the ototoxic agent cisplatin. Two doses of cisplatin were injected intravenously into anesthetized carriers and weight-matched control animals. Prior to and 96 h after the injections hearing thresholds were established by recording the auditory brainstem responses at 3.5, 7, 14, and 28 kHz. The cochleae were harvested to estimate hair cell loss and to analyze total platinum content. The carriers of the German waltzing guinea pig strain suffered from a more pronounced cisplatin-induced hearing loss compared to the control animals. The results suggest that mechanisms responsible for the protection against acoustic stress do not provide any protection against cisplatin in carriers of the German waltzing guinea pig.
Neuro-Otological Findings in Patients with Migraine- and Nonmigraine-Related Dizziness
Authors: Vitkovic Jessica , Paine Mark , Rance Gary
Published: November 2007

This study presents the neuro-otological findings of 523 patients attending a tertiary vestibular clinic with migraine- and nonmigraine-related dizziness. Subjects were categorized into one of 4 groups, definite migrainous vertigo, probable migrainous vertigo, vestibular disorder coexisting with migraine and nonmigraine-related dizziness. No notable relationship was found between the numbers of abnormal findings between the groups for the majority of the neuro-otological tests. However, there was a significant trend in emetic response to caloric testing. The definite migrainous vertigo group were at least 4 times more likely to be nauseous to caloric testing than any other migraine category. This difference was independent of the magnitude of caloric responses between the emetic migraine groups. While further investigation is required, this study has potentially identified that nauseous/emetic response to caloric stimulation may be a distinguishing factor between migrainous vertigo and other vestibular disorders including those with a coexisting history of migraine.