bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological Differences between Hatchery and Wild Populations of Coho Salmon (Oncorhynchus kisutch): Environmental versus Genetic Origin
Authors: Swain D. P. , Riddell B. E. , Murray C. B.
Published: August 2008

Previous studies have demonstrated morphological differences between hatchery-reared coho salmon (Oncorhynchus kisutch) of hatchery origin and wild-reared coho of wild origin. We tested for a genetic component to this divergence by comparing coho from hatchery and wild populations both reared in the same hatchery environment and for an environmental component by comparing hatchery- and wild-reared coho both of wild origin. As in the previous studies, wild-reared fish from wild populations had greater head dimensions, larger median fins, and deeper bodies than did hatchery-reared fish from hatchery populations. This difference, summarized by the first principal component (PC1) of the size-adjusted data, was related to rearing environment rather than to genetic differences between hatchery and wild populations. Genetic divergence (or maternal effects) did occur between hatchery and wild populations along PC2 and PC3, but this divergence was slight compared with the environmentally induced differences between the two types of fish along PC1.
Biochemical Characterization of Third-Stage Larval Sealworm, Pseudoterranova decipiens (Nematoda: Anisakidae), in Canadian Atlantic Waters using Isoelectric Focusing of Soluble Proteins
Authors: Appleton Tracey E. , Burt M. D. B.
Published: August 2008

Isoelectric focusing (IEF) was performed on soluble protein extracts from whole specimens of third-stage larval sealworm (Pseudoterranova decipiens) recovered from the musculature of three fish intermediate host species: Atlantic cod (Gadus morhua), sea raven (Hemitripterus americanus), and rainbow smelt (Osmerus mordax). The fish were collected at various sites in the Canadian Atlantic, and IEF revealed the occurrence of two "variants" within what has previously been considered a single, uniform species of P. decipiens in these waters. The larvae were characterized by the absence ("type I" L3's) or presence ("type II" L3's) of a sharp, dark-staining protein band with a mean pl of 6.46 pH units. Type I larvae were predominant at two sites sampled in the lower Bay of Fundy, while type II larvae were predominant at three sites sampled in the Gulf of St. Lawrence region.
Analysing differences between two age determination methods by tests of symmetry
Authors: Hoenig J. M. , Morgan M. J. , Brown C. A.
Published: August 2008

A common problem in fisheries science is the comparison of two methods for obtaining ages of individual animals. Often, indices of precision are computed for this purpose. We believe such indices are inappropriate both as measures of precision and for comparative purposes because they do not properly account for age effects or take the experimental design into consideration. We suggest that if the overall level of agreement is low between two ageing methods used on the same sample of fish, then one can use a test of symmetry to look for evidence of systematic disagreement. A χ2 test is used to determine if the number of fish assigned age i from method 1 and age j from method 2 differs significantly from the number of fish assigned age j from method 1 and age i from method 2. Such a test can also be used to determine the range of nominal ages over which two methods appear to give comparable results.
Implications of trip regulations for high-grading; a model of the behavior of fishermen
Authors: Gillis Darren M. , Peterman Randall M. , Pikitch Ellen K.
Published: August 2008

We developed a simulation model, based on observations of the actions of fishermen, to determine how regulations on trips by management agencies may influence discarding behavior at sea. Our model employed the results of a separate dynamic optimization model and data from the Oregon groundfish trawl fishery to predict quantitative patterns of high-grading expected across a range of regulatory limits on both fishing effort and the quantity of landings per trip (trip quota). In all cases, the total seasonal landings were assumed to be constant. High-grading was predicted to be greatest when there is a high probability of the catch exceeding the trip quotas, as when effort limits are high and trip quotas are low. Our evaluation of regulations also considered indicators such as expected economic value of the trip, proportion of trip landing limit attained, and the number of trips made in a season. A combination of large trip landing limits and intermediate trip effort limits best satisfied the multiple goals typically used by management agencies.
An evaluation of light-mediated vertical migration of fish based on hydroacoustic analysis of the diel vertical movements of rainbow smelt (Osmerus mordax)
Authors: Appenzeller A. R. , Leggett W. C.
Published: August 2008

We used hydroacoustics to examine diel changes in the vertical distributions of rainbow smelt, Osmerus mordax, in Lake Memphremagog, Quebec/Vermont. Our objective was to evaluate hypotheses linking diel vertical movements of fish with light levels. Smelt distributions were also monitored from June through October (1988 and 1990) to evaluate seasonal changes in their behavior. A strong relationship (r2 = 0.83) between ambient light intensities and the upper fish layer in the water column was observed. Fish depth was also related to the depth of the thermocline during the night and when surface water temperatures were > 18 °C. The most characteristic feature was the strong avoidance of light levels > 0.1 μW/cm2. However, we found considerable variation in lower light levels experienced by the whole fish population. The results suggest that existing models of anti-predation behavior relating light and fish depth are consistent, with some limitations, with patterns of diel vertical migration in rainbow smelt.
Effects of 3,3′,4,4′-tetrachlorobiphenyl on the dynamics of vitamin A in brook trout (Salvelinus fontinalis) and intestinal retinoid concentrations in lake sturgeon (Acipenser fulvescens)
Authors: Ndayibagira Aristocle , Cloutier Marie-Josée , Anderson Perry D. , Spear Philip A.
Published: August 2008

A single i.p. injection of 5 μg 3,3′,4,4′-tetrachlorobiphenyl (TCBP)/g body mass in adult brook trout (Salvelinus fontinalis) resulted in decreased (p < 0.0001) growth rate despite pair feeding. Plasma retinol decreased (p < 0.0037). Intestinal retinyl palmitate (RP) and 3,4-dehydroretinyl palmitate (DRP) concentrations decreased in TCBP-injected males (RP, p < 0.0143; DRP, p < 0.0009), whereas retinoid levels did not decrease significantly in TCBP-injected females. The RP:DRP ratio in trout liver increased (p < 0.0001). These results suggested that DRP is more sensitive than RP to the effects of TCBP. No significant differences in ovarian retinoids occurred in post-spawning trout. Field validation of the effects on intestinal retinoids was conducted with lake sturgeon (Acipenser fulvescens) caught at a contaminated site on the Des Prairies River near Montréal (St. Lawrence River population) and reference sturgeon taken from a site near the origin of the Ottawa River in LaVerendrye Park. Intestinal retinoid concentrations were lower (RP, p < 0.0008; DRP, p < 0.0004) in the St. Lawrence River sturgeon. Our results demonstrate that a coplanar PCB is capable of altering vitamin A dynamics in several tissues and organs, and may cause a lowering of retinoids in the intestine.
Growth and maturation of the benthic stages of male snow crab, Chionoecetes opilio (Brachyura: Majidae)
Authors: Sainte-Marie Bernard , Raymond Sylvain , Brêthes Jean-Claude
Published: August 2008

Growth and maturation of postlarval male snow crab (Chionoecetes opilio) in an exploited Gulf of Saint Lawrence population were elucidated using size distributions in beam trawl samples taken bimonthly from April 1991 to May 1992, moult and maturity indices, and measures of growth per moult. Males develop in three stages: immature, without spermatophores; adolescent, with spermatophores but undifferentiated chelae; and adult, with spermatophores and differentiated chelae. Males change from immature to adolescent after a puberty moult, and from adolescent to adult after a terminal moult producing a final carapace width (CW) >40 mm. The slope of the regression relating post- to pre-moult CW decreases after puberty. Carapace moult increments are the same at pre-terminal and terminal moults, for a constant premoult CW. Males recruit to the legal size of 95-mm CW at instar XII, ≈8.7 years or more after settlement. The slope of the regression of gonad weight on CW is less for adult than for adolescent males owing to the formers' participation in reproduction and to greater depletion of sperm stores in large than in small adult males. Gonad weight increases with time since moult, but for large adults, did not reach levels recorded in prefishery times or in an unfished population.
Influence of food and predation on the depth distribution of juvenile spot (Leiostomus xanthurus) in tidal nurseries
Authors: Miltner Robert J. , Ross Steve W. , Posey Martin H.
Published: August 2008

Relative abundances of young-of-the-year (YOY) spot (Leiostomus xanthurus) sampled by trawling in two tidal creeks on Masonboro Island, North Carolina, were highest in the shallow creek margins. Abundances of benthic invertebrates sampled by cores in one of the study creeks, were also maximal at the creek margin. Polychaetes associated with the creek margin composed the largest fraction of spot diets, indicating spot located in the creek margins were in the area of highest food availability. Spot predators sampled by trawling and seining were uncommon and were primarily juvenile (75–200 mm total length) southern flounder (Paralichthys lethostigma), hake (Urophycis spp.), and bluefish (Pomotomus saltatrix). Large YOY spot experienced a size refuge from predation, as only small YOY spot were found in predator stomachs. In laboratory experiments testing the effects of the presence of a predator, food, or both food and predators on the depth distribution of YOY spot, food had a stronger effect on spot distributions than predators The results of field observations and laboratory experiments suggest food has the strongest effect on spot distribution in the field, and that food is relatively more important than refuge from predation to the nursery function of shallow estuarine habitats.
Development of digestive organs and feeding ability in larvae of Japanese eel (Anguilla japonica)
Authors: Kurokawa Tadahide , Kagawa Hirohiko , Ohta Hiromi , Tanaka Hideki , Okuzawa Koichi , Hirose Keiji
Published: August 2008

As part of a study on the early life of Japanese eel, the development of the digestive organs was observed during the 13 d after hatching. The digestive tract was formed only at the pharynx at hatching; the posterior part of the duct differentiated during 1 d posthatch (DPH). Pancreas and liver started to develop at 3 DPH. Immunohistochemistry using an antibody to eel trypsinogen showed weak signals first appearing in the pancreas at 6 DPH, suggesting that the eel pancreas starts to synthesize digestive enzymes at 6 DPH. The immunohistochemical signals became strong at 7 DPH, at which time the mouth opening orientation moved from ventral to anterior, the intestine differentiated into small intestine and rectum and the yolk was absorbed. Rotifers were first observed in the digestive tract of 13-d-old larvae. We inferred from the developmental process of the digestive organs that the larvae can start feeding at 7 DPH, which is earlier than observations of first feeding.
Diving behaviour of harbour porpoises, Phocoena phocoena
Authors: Westgate Andrew J. , Head Andrew J. , Berggren Per , Koopman Heather N. , Gaskin David E.
Published: August 2008

The diving behaviour of seven free-ranging harbour porpoises (Phocoena phocoena) was examined using time–depth recorders. In total, 8167 individual dives were recorded over 254 h. The longest period of data collection from an individual was 106.1 h. Mean dive depths and durations ranged from 14 ± 16 to 41 ± 32 m, and from 44 ± 37 to 103 ± 67 s, respectively. The maximum recorded dive depth and duration was 226 m and 321 s. This performance may not represent the maximum capacity of harbour porpoises but rather the maximum depth of the study area. Individual dives had similar rates of descent and ascent, which ranged from 1.1 ± 0.6 to 2.3 ± 1.4 m/s, and from 0.9 ± 0.6 to 2.1 ± 1.4 m/s, respectively. Two porpoises with monitoring periods >2 days demonstrated a diel pattern in their diving, making fewer, but deeper dives at night. Comparison of the diving behaviour of harbour porpoises with data on the depth of 140 porpoises entanglements in groundfish gill nets in the Bay of Fundy showed these seven porpoises made between 22 and 70% of dives to depths (range 20–130 m) where the majority of entanglements were reported.
Testing the temporal and spatial validity of site-specific models derived from airborne remote sensing of phytoplankton
Authors: Millie David F. , Vinyard Bryan T. , Baker Michael C. , Tucker Craig S.
Published: August 2008

Validations of predictive models are necessary for the accurate application of remotely sensed imagery within ecological research and fisheries management. Multiple regression models derived from airborne imagery on 16 May 1990 accurately depicted phytoplankton biomass and turbidity within aquaculture impoundments. To examine their temporal validity, the exact models, as well as identical model forms, were fit to similar imagery and in situ data collected on 20 June 1990. None of the exact models for 16 May accurately predicted in situ data on 20 June; however, model forms were robust for describing in situ variables. To examine their spatial validity, identical model forms were fit to in situ data partitioned among phytoplankton composition and biomass. The fit of the models and the contribution of imagery variables to the models varied among in situ variables. Although imagery variables explained all of the observed variability for turbidity, regression tree modeling indicated that a significant proportion of the variability in chlorophyll distribution both among and within impoundments was explained through both imagery variables and phytoplankton biomass. Consequently, universal models for the airborne remote sensing of water-quality variables in systems having distinct optical signatures is unlikely. Rather, robust site-specific models will need to be developed.
Restoration of endothelin-1-induced impairment in endothelium-dependent relaxation by interleukin-10 in murine aortic ringsThis article is one of a selection of papers published in the special issue (part 2 of 2) on Forefronts in Endothelin.
Authors: Zemse Saiprasad M. , Hilgers Rob H.P. , Simkins G. Bryan , Rudic R. Daniel , Webb R. Clinton
Published: August 2008

Endothelin-1 (ET-1) is implicated in the development of endothelial dysfunction through the generation of reactive oxygen species by NADPH oxidase activation. Interleukin-10 (IL-10) is an antiinflammatory cytokine that stimulates nitric oxide production, decreases superoxide production, and restores endothelial integrity after vascular injury. In this study, we tested whether IL-10 attenuates ET-1-induced endothelial dysfunction by improving acetylcholine (ACh)-induced relaxation of cultured murine aortic rings. Aortic rings (2 mm long) of C57BL/6 mice were incubated in 2 mL DMEM containing 120 U/mL penicillin and 120 μg/mL streptomycin in the presence of one of 4 treatments: vehicle (deionized water), ET-1 (100 nmol/L), recombinant mouse IL-10 (300 ng/mL), or a combination of both ET-1 and IL-10. After incubation at 37 °C for either 1 or 6 h (short-term exposure) or 22 h (overnight exposure), rings were mounted in a wire myograph and stretched to a passive force of 5 mN. Endothelium-dependent vasorelaxation was assessed by constructing cumulative concentration–response curves to ACh (0.001–10 μmol/L) during 10 μmol/L phenylephrine (PE)-induced contraction. Short-term exposure of ET-1 did not result in an impairment of ACh-induced relaxation. Overnight exposure of aortic rings to ET-1 resulted in a statistically significant endothelial dysfunction characterized by a reduced maximal relaxation response to ACh compared with that of untreated rings (Emax 57% ± 3% versus 82% ± 4%). IL-10 treatment restored ACh-induced relaxation (Emax 77% ± 3%). Western blotting showed decreased eNOS expression in response to ET-1, whereas vessels treated with a combination of ET-1 and IL-10 showed increased expression of eNOS. Immunohistochemical analysis showed decreased eNOS expression in ET-1-treated vessels compared with those treated with both ET-1 and IL-10. We conclude that, in murine aorta, the antiinflammatory cytokine IL-10 prevents impairment in endothelium-dependent relaxation induced in response to long-term incubation with ET-1 via normalization of eNOS expression.
Antagonism of endothelin-1 inhibits hypoxia-induced apoptosis in cardiomyocytesThis article is one of a selection of papers published in the special issue (part 2 of 2) on Forefronts in Endothelin.
Authors: Ren Anjing , Yan Xiaohong , Lu Hong , Shi Jingsong , Yin Yuanjun , Bai Jie , Yuan Wenjun , Lin Li
Published: August 2008

Apoptosis is well documented to be a common feature of many pathological processes of the heart. Exogenous endothelin-1 (ET-1) has been shown to be proapoptotic or antiapoptotic, depending on ET-1 concentration, cell type, and the ratio of ETA/ETBreceptor subtypes. The role of endogenous ET-1 in cardiomyocyte apoptosis, however, is not clarified. This study observed the effects of the ETA-receptor antagonists BQ610 and BQ123 and the ETB-receptor antagonist BQ788 on hypoxia-induced apoptosis in primary cultured neonatal rat cardiomyocytes. Hypoxic apoptosis was induced by incubating cardiomyocytes in serum-free medium under 3% O2and 5% CO2for 24 h and evaluated by TUNEL analysis and flow cytometry. TUNEL analysis showed that the apoptotic cardiomyocytes constituted 24.2% ± 2.2% of the total cells under hypoxic conditions. Treatment with BQ610 (5 μmol/L) significantly reduced the apoptosis rate to 13.2% ± 3.7% (data from 4 independent experiments, p < 0.01 vs. hypoxia). Flow cytometry showed that the percentage of apoptotic cells positively stained with annexin V and propidium iodide was 42.76% ± 4.44% (n = 12) in cultures subjected to hypoxia. BQ123 at 0.04, 0.2, and 1.0 μmol/L dose-dependently reduced the apoptosis rate to 34.00% ± 10.35% (n = 6, p < 0.05), 30.38% ± 8.28% (n = 6, p < 0.01), and 22.89% ± 4.19% (n = 6, p < 0.01), respectively. In contrast, BQ788 did not affect hypoxic apoptosis. These findings suggested that endogenous ET-1 contributed to hypoxia-induced apoptosis in cultured cardiomyocytes, which was mediated by ETAreceptors, but not by ETBreceptors.
The endothelin axis in cancer: the promise and the challenges of molecularly targeted therapyThis article is one of a selection of papers published in the special issue (part 2 of 2) on Forefronts in Endothelin.
Authors: Bagnato Anna , Spinella Francesca , Rosanò Laura
Published: August 2008

The endothelin (ET) axis, which includes ET-1, ET-2, ET-3, and 2 G protein-coupled receptor subtypes, ETAR and ETBR, promotes growth and progression of a variety of tumors, such as prostatic, ovarian, renal, pulmonary, colorectal, cervical, breast, lung, bladder, endometrial carcinoma, Kaposi’s sarcoma, brain tumors, and melanoma. Acting on selective receptors, ET-1 regulates mitogenesis, cell survival, angiogenesis, bone remodeling, stimulation of nociceptors, tumor-infiltrating immune cells, epithelial-to-mesenchymal transition, invasion, and metastatic dissemination. At the molecular level, endothelin receptor antagonists, besides providing ideal tools for dissecting the ET axis, have demonstrated their potential in developing novel therapeutic strategies. Emerging experimental and clinical data demonstrate that interfering with endothelin receptors provides an opportunity for the development of rational combinatorial approaches using endothelin receptor antagonists in combination with chemotherapy or molecularly targeted therapy.
EXPERIENCE-CONSISTENT MODELING FOR RADIAL BASIS FUNCTION NEURAL NETWORKS
Authors: PEDRYCZ WITOLD , RAI PARTAB , ZURADA JOZEF
Published: September 2008

We develop a new approach to the design of neural networks, which utilizes a collaborative framework of knowledge-driven experience. In contrast to the "standard" way of developing neural networks, which explicitly exploits experimental data, this approach incorporates a mechanism of knowledge-driven experience. The essence of the proposed scheme of learning is to take advantage of the parameters (connections) of neural networks built in the past for the same phenomenon (which might also exhibit some variability over time or space) for which are interested to construct the network on a basis of currently available data. We establish a conceptual and algorithmic framework to reconcile these two essential sources of information (data and knowledge) in the process of the development of the network. To make a presentation more focused and come up with a detailed quantification of the resulting architecture, we concentrate on the experience-based design of radial basis function neural networks (RBFNNs). We introduce several performance indexes to quantify an effect of utilization of the knowledge residing within the connections of the networks and establish an optimal level of their use. Experimental results are presented for low-dimensional synthetic data and selected datasets available at the Machine Learning Repository.
A NEW METHOD FOR THE RE-IMPLEMENTATION OF THRESHOLD LOGIC FUNCTIONS WITH CELLULAR NEURAL NETWORKS
Authors: BÉNÉDIC Y. , WIRA P. , MERCKLÉ J.
Published: September 2008

A new strategy is presented for the implementation of threshold logic functions with binary-output Cellular Neural Networks (CNNs). The objective is to optimize the CNNs weights to develop a robust implementation. Hence, the concept of generative set is introduced as a convenient representation of any linearly separable Boolean function. Our analysis of threshold logic functions leads to a complete algorithm that automatically provides an optimized generative set. New weights are deduced and a more robust CNN template assuming the same function can thus be implemented. The strategy is illustrated by a detailed example.
A MODIFIED LAMSTAR NEURAL NETWORK AND ITS APPLICATIONS
Authors: SCHNEIDER NATHAN C. , GRAUPE DANIEL
Published: September 2008

This paper describes a modification of the LArge Memory STorage And Retrieval (LAMSTAR) neural network. The purpose of the modification is to allow rare events a larger role in decision-making when they are strongly biased towards a particular decision. As a by-product, the modification also permits the introduction of a confidence measure. This measure allows comparison across different network inputs so that the user may choose the "best" solution. The authors have applied the modified LAMSTAR network to a financial forecasting problem.
COLOR IMAGE SEGMENTATION WITH SUPPORT VECTOR MACHINES: APPLICATIONS TO ROAD SIGNS DETECTION
Authors: CYGANEK BOGUSŁAW
Published: September 2008

In this paper we propose efficient color segmentation method which is based on the Support Vector Machine classifier operating in a one-class mode. The method has been developed especially for the road signs recognition system, although it can be used in other applications. The main advantage of the proposed method comes from the fact that the segmentation of characteristic colors is performed not in the original but in the higher dimensional feature space. By this a better data encapsulation with a linear hypersphere can be usually achieved. Moreover, the classifier does not try to capture the whole distribution of the input data which is often difficult to achieve. Instead, the characteristic data samples, called support vectors, are selected which allow construction of the tightest hypersphere that encloses majority of the input data. Then classification of a test data simply consists in a measurement of its distance to a centre of the found hypersphere. The experimental results show high accuracy and speed of the proposed method.
NEW METAHEURISTIC APPROACHES FOR THE LEAF-CONSTRAINED MINIMUM SPANNING TREE PROBLEM
Authors: SINGH ALOK , BAGHEL ANURAG SINGH
Published: September 2008

Given an undirected, connected, weighted graph, the leaf-constrained minimum spanning tree (LCMST) problem seeks a spanning tree of the graph with smallest weight among all spanning trees of the graph, which contains at least l leaves. In this paper we have proposed two new metaheuristic approaches for the LCMST problem. One is an ant-colony optimization (ACO) algorithm, whereas the other is a tabu search based algorithm. Similar to a previously proposed genetic algorithm, these metaheuristic approaches also use the subset coding that represents a leaf-constrained spanning tree by the set of its interior vertices. Our new approaches perform well in comparison with two best heuristics reported in the literature for the problem — the subset-coded genetic algorithm and a greedy heuristic.
SOLVING THE GENERALIZED BURGERS–KdV EQUATION BY A COMBINATION METHOD
Authors: XIE YUANXI
Published: September 2008

In view of the analysis on the characteristics of the generalized Burgers equation, generalized KdV equation and generalized Burgers–KdV equation, a combination method is presented to seek the explicit and exact solutions to the generalized Burgers–KdV equation by combining with those of the generalized Burgers equation and generalized KdV equation. As a result, many explicit and exact solutions for the generalized Burgers–KdV equation are successfully obtained by this technique.
THE INTEGRABLE PROPERTY OF LOTKA–VOLTERRA TYPE DISCRETE NONLINEAR LATTICE SOLITON SYSTEMS
Authors: LI XIN-YUE , XU XI-XIANG , ZHAO QIU-LAN
Published: September 2008

A hierarchy of discrete lattice soliton equation is obtained by using a novel algebraic system, and its Hamiltonian structure is generated by use of the Tu model. Then, conservation laws and integrable coupling of the obtained equation hierarchies are discussed.
GROWTH AND CHARACTERIZATION OF GLYCINE HYDROBROMIDE SINGLE CRYSTAL FOR NONLINEAR OPTICAL APPLICATIONS
Authors: KIRUBAVATHI K. , SELVARAJU K. , VIJAYAN N. , KUMARARAMAN S.
Published: September 2008

Single crystals of a new semi-organic nonlinear optical material glycine hydrobromide were grown from solution by slow evaporation at room temperature. Good optical quality single crystals with dimensions 17×8×5 mm3 were obtained. The grown crystal had been confirmed by single-crystal X-ray diffraction and the vibrational frequencies of various functional groups in the crystals had been derived from Fourier transform infrared spectrum. The optical quality of the grown crystals was analyzed by the Ultraviolet visible spectrum method. The mechanical behavior of the grown crystal was evaluated by Vickers' micro-hardness indentation method. The nonlinear optical property of the crystal was confirmed by the Kurtz powder technique using Nd : YAG laser as a source.
FACE RECOGNITION BY ARTIFICIAL VISION SYSTEMS: A COGNITIVE PERSPECTIVE
Authors: RADUCANU BOGDAN , VITRIÀ JORDI
Published: September 2008

Cognitive development refers to the ability of a system to gradually acquire knowledge through experiences during its existence. As a consequence, the learning strategy should be represented as an integrated, online process that aims to build a model of the "world" and a continuous update of this model. Considering as reference the Modal Model of Memory introduced by Atkinson and Schiffrin, we propose an online learning algorithm for cognitive systems design. The incremental part of the algorithm is responsible of updating existing information or creating new data categories and the decremental part, to efficiently evaluate the system's performance facing partial or total loss of data. The proposed algorithm has been applied to the face recognition problem. More generally, the current approach can be extended to large-scale classification problems, to limit the memory requirements for optimal data representation and storage.
A GRAPH-BASED ALGORITHM FOR CLUSTER DETECTION
Authors: FOGGIA PASQUALE , PERCANNELLA GENNARO , SANSONE CARLO , VENTO MARIO
Published: September 2008

In some Computer Vision applications there is the need for grouping, in one or more clusters, only a part of the whole dataset. This happens, for example, when samples of interest for the application at hand are present together with several noisy samples.

In this paper we present a graph-based algorithm for cluster detection that is particularly suited for detecting clusters of any size and shape, without the need of specifying either the actual number of clusters or the other parameters.

The algorithm has been tested on data coming from two different computer vision applications. A comparison with other four state-of-the-art graph-based algorithms was also provided, demonstrating the effectiveness of the proposed approach.
IRONIC EXPRESSIONS AND MOVING WORDS
Authors: STOCK OLIVIERO , STRAPPARAVA CARLO , VALITUTTI ALESSANDRO
Published: September 2008

Among forms of creative language, verbal humor has received some attention in the computational milieu. Some aspects of irony and wordplay could be experimented in automated systems. For instance, we developed a system that makes fun of existing acronyms, based mainly on lexical reasoning. The dimension of emotion in words is also starting to be understood among computational linguists. The challenge of electronic advertisements offers in particular a great opportunity for getting now deeper into creative language expression and emotion. An advertising message induces in the recipient a positive or negative attitude toward the advertised object. A prototype we have developed for advertising professionals has two steps: (i) the creative variation of familiar expressions, taking into account the effective content of the produced text, (ii) the automatic animation (semantically consistent with the affective text content) of the resulting expression, using kinetic typography techniques. In this way the ironic-affective effect is perceptually emphasized.
NEURAL OBJECT RECOGNITION BY HIERARCHICAL APPEARANCE LEARNING
Authors: OBERHOFF DANIEL , KOLESNIK MARINA
Published: September 2008

We present a system for object recognition that is largely inspired by physiologically identified processing streams in the visual cortex, specifically in the ventral stream. It consists of neural units organized in a hierarchy of layers with encoding features of increasing complexity. A key feature of the system is that the neural units learn their preferred patterns from visual input alone. Through this "soft wiring" of neural units the system becomes tuned for target object classes through passive visual experience and no labels are required in this stage. Object labels are only introduced in the last step to train a classifier on the system's output. While this tuning process is purely feed-forward we also present a neural mechanism for back projection of the learned image patterns down the hierarchical layers, and demonstrate how this feedback can be used to stabilize the system in the presence of noise. We test the neural system with natural images from publicly available data-sets of natural scenes and handwritten digits.
A NEURAL NETWORK-BASED CLASSIFICATION MODEL FOR PARTIAL EPILEPSY BY EEG SIGNALS
Authors: SAHIN CENK , OGULATA SEYFETTIN NOYAN , ASLAN KEZBAN , BOZDEMIR HACER , EROL RIZVAN
Published: September 2008

Epilepsy is a disorder of cortical excitability and still an important medical problem. The correct diagnosis of a patient's epilepsy syndrome clarifies the choice of drug treatment and also allows an accurate assessment of prognosis in many cases. The aim of this study is to evaluate epileptic patients and classify subgroups of partial epilepsy by Multilayer Perceptron Neural Networks (MLPNNs). This is the first study to classify the partial epilepsy groups using the neural network according to EEG signals. 418 patients with epilepsy diagnoses according to International League against Epilepsy (ILAE, 1981) were included in this study. The epilepsy outpatients at the Neurology Department Clinic of Cukurova University Medical School between the years of 2002–2005 were examined and included in the study. The MLPNNs were trained by the parameters obtained from the EEG signals and clinical findings of the patients. Test results show that the MLPNN model is able to classify partial epilepsy with an accuracy of 91.5%. Moreover, new MLPNNs were constructed for determining significant variables on classification. The loss of consciousness in the course of seizure time variable caused the largest decrease in the classification accuracy when it was left out. In conclusion, we think that the classification performance of MLPNN model for partial epilepsy is satisfactory and this model may be used in clinical studies as a decision support tool to determine the partial epilepsy classification of the patients.
ROBOT NAVIGATION BASED ON NEUROSYMBOLIC REASONING OVER LANDMARKS
Authors: CORAGGIO PAOLO , DE GREGORIO MASSIMO , FORASTIERE MANOLO
Published: September 2008

In this paper a neurosymbolic hybrid system for robot self-localization is proposed. This crucial issue in autonomous robotic research field has been tackled with slightly different approaches depending mainly on robot sensors and actuation devices, its available computational resources, and the environment in which it acts. The system we present has been designed for robot endowed with poor sensors (a 16-element sonar array, a camera just performing very light computation, odometric sensors) which acts in an office-like environment. In the proposed landmark based approach, we have considered as "natural" environmental features the corners formed by wall intersections, and corners formed by doors that are present in the scene. The whole problem, from landmark recognition to position estimation, is carried out by a unified neurosymbolic system.
VISUAL FEATURE BINDING WITHIN THE SELECTIVE TUNING ATTENTION FRAMEWORK
Authors: ROTHENSTEIN ALBERT L. , RODRÍGUEZ-SÁNCHEZ ANTONIO J. , SIMINE EVGUENI , TSOTSOS JOHN K.
Published: September 2008

We present a biologically plausible computational model for solving the visual feature binding problem, based on recent results regarding the time course and processing sequence in the primate visual system. The feature binding problem appears due to the distributed nature of visual processing in the primate brain, and the gradual loss of spatial information along the processing hierarchy. This paper puts forward the proposal that by using multiple passes of the visual processing hierarchy, both bottom-up and top-down, and using task information to tune the processing prior to each pass, we can explain the different recognition behaviors that primate vision exhibits. To accomplish this, four different kinds of binding processes are introduced and are tied directly to specific recognition tasks and their time course. The model relies on the reentrant connections so ubiquitous in the primate brain to recover spatial information, and thus allow features represented in different parts of the brain to be integrated in a unitary conscious percept. We show how different tasks and stimuli have different binding requirements, and present a unified framework within the Selective Tuning model of visual attention.
WHAT THE DRAUGHTSMAN'S HAND TELLS THE DRAUGHTSMAN'S EYE: A SENSORIMOTOR ACCOUNT OF DRAWING
Authors: CAGLI RUBEN COEN , CORAGGIO PAOLO , NAPOLETANO PAOLO , BOCCIGNONE GIUSEPPE
Published: September 2008

In this paper we address the challenging problem of sensorimotor integration, with reference to eye-hand coordination of an artificial agent engaged in a natural drawing task. Under the assumption that eye-hand coupling influences observed movements, a motor continuity hypothesis is exploited to account for how gaze shifts are constrained by hand movements. A Bayesian model of such coupling is presented in the form of a novel Dynamic Bayesian Network, namely an Input–Output Coupled Hidden Markov Model. Simulation results are compared to those obtained by eye-tracked human subjects involved in drawing experiments.
A SUPPORT VECTOR DATA DESCRIPTION APPROACH FOR BACKGROUND MODELING IN VIDEOS WITH QUASI-STATIONARY BACKGROUNDS
Authors: TAVAKKOLI ALIREZA , NICOLESCU MIRCEA , BEBIS GEORGE , NICOLESCU MONICA
Published: September 2008

Video segmentation is one of the most important tasks in high-level video processing applications. Stationary cameras are usually used in applications such as video surveillance and human activity recognition. However, possible changes in the background of the video such as waving flags, fluctuating monitors, water surfaces, etc. make the detection of objects of interest particularly challenging. These types of backgrounds are called quasi-stationary backgrounds. In this paper we propose a novel, non-statistical technique to generate a background model and use this model for background subtraction and foreground region detection in the presence of such challenges. The main advantage of the proposed method over the state of the art is that unlike statistical techniques the accuracy of foreground regions is not limited to the estimate of the probability density. Also, the memory requirements of our method are independent of the number of training samples. This makes the proposed method useful in various scenarios including the presence of slow changes in the background. A comprehensive study is presented on the efficiency of the proposed method. Its performance is compared with various existing techniques quantitatively and qualitatively to show its superiority in various applications.
GENETIC-BASED APPROACH FOR SYNTHESIZING TEXTURE
Authors: CHANG CHIN-CHEN , KUO YEN-TING , TAI WEN-KAI
Published: September 2008

Intensive search schemes are commonly adopted in patched-based texture synthesis to identity the proper neighbors of each patch. However, they do not always provide perfect solutions. This work presents a genetic algorithm in evolutionary computation for patch-based texture synthesis. The representation of an input source texture is first adjusted. Then, the synthesizing result is generated and refined by the selection of individuals based on their fitness and executing crossover and mutation until the criteria are met. After the entire execution, a large output texture is generated with texture features similar to the source texture. Because this approach optimizes the genetic algorithm, the results are satisfactory.
RECOGNITION OF PROTEIN FUNCTION USING THE LOCAL SIMILARITY
Authors: ALEXANDROV KIRILL , SOBOLEV BORIS , FILIMONOV DMITRY , POROIKOV VLADIMIR
Published: September 2008

The functional annotation of amino acid sequences is one of the most important problems in bioinformatics. Different programs have been successfully applied for recognition of some functional classes; nevertheless, many functional groups still cannot be predicted with the required accuracy. We developed a new method for protein function recognition using the original approach of sequence description. Each sequence of the training set is compared with the query sequence, and the local similarity scores are calculated for the query sequence positions and used as input data for the original classifier. The method was tested using leave-one-out cross-validation for three data sets covering 58 enzyme classes. Two tested sets including noncrossing functional classes were recognized with high accuracy at various levels of classification hierarchy. The majority of these classes were predicted with 100% accuracy, showing a prediction ability comparable with the HMMer method and an accuracy superior to the SVM-Prot program. When the tested set was composed of intersected classes of ligand specificity, the prediction accuracy was less; however, the accuracy increased as the size of the predicted class expanded. The proposed method can be used for both predicting protein functional class and selecting the functionally significant sites in a sequence.
HUMAN TRASH ESTs — SEQUENCES FROM cDNA COLLECTION THAT ARE NOT ALIGNED TO GENOME ASSEMBLY
Authors: PANCHIN ALEXANDER Y. , SPIRIN SERGEY A. , LUKYANOV SERGEY A. , LEBEDEV YURI B. , PANCHIN YURI V.
Published: September 2008

Expressed sequence tags (ESTs) represent 500–1000-bp-long sequences corresponding to mRNAs derived from different sources (cell lines, tissues, etc.). The human EST database contains over 8,000,000 sequences, with over 4,000,000,000 total nucleotides. RNA molecules are transcribed from a genomic DNA template; therefore, all ESTs should match corresponding genomes. Nevertheless, we have found in the human EST database approximately 11,000 ESTs not matching sequences in the human genome database. The presence of "trash" ESTs (TESTs) in the EST database could result from DNA or RNA contamination of the laboratory equipment, tissues, or cell lines. TESTs could also represent sequences from unidentified human genes or from species inhabiting the human body. Here, we attempt to identify the sources of human EST database contaminations. In particular, we discuss systematic contamination of the mammalian EST databases with sequences of plants.
The Impact of Natural Selection on the Genome: Emerging Patterns in Drosophila and Arabidopsis
Authors: Wright Stephen I. , Andolfatto Peter
Published: September 2008

Species in the Drosophila and Arabidopsis species groups share the feature of having relatively small, streamlined genomes. In Drosophila, evidence for pervasive negative and positive selection is overturning long-held views about the functional significance of noncoding DNA, the frequency of positive selection, and the extent to which coding and noncoding polymorphism and divergence between species is neutral. However, despite sharing some similarities with Drosophila, Arabidopsis shows quite distinct patterns of selective constraint and positive selection. Two conspicuous differences between these species groups are their effective population sizes and population structure, which may explain lower levels of selective constraint in coding and noncoding DNA of Arabidopsis, more evidence for balancing selection and less evidence for canonical signature of positive selection than in Drosophila species. As more comparative genomic data accumulate in the Arabidopsis group, the combination of polymorphism and divergence data allow these initial contrasts to be quantified on a genomic scale.
The Evolution of Animal Weapons
Authors: Emlen Douglas J.
Published: September 2008

Males in many species invest substantially in structures that are used in combat with rivals over access to females. These weapons can attain extreme proportions and have diversified in form repeatedly. I review empirical literature on the function and evolution of sexually selected weapons to clarify important unanswered questions for future research. Despite their many shapes and sizes, and the multitude of habitats within which they function, animal weapons share many properties: They evolve when males are able to defend spatially restricted critical resources, they are typically the most variable morphological structures of these species, and this variation honestly reflects among-individual differences in body size or quality. What is not clear is how, or why, these weapons diverge in form. The potential for male competition to drive rapid divergence in weapon morphology remains one of the most exciting and understudied topics in sexual selection research today.
Insect Herbivore Nutrient Regulation
Authors: Behmer Spencer T.
Published: September 2008

The primary reason animals, including insect herbivores, eat is to acquire a mix of nutrients needed to fuel the processes of growth, development, and reproduction. Most insect herbivores strongly regulate their nutrient intake when given the opportunity. When they are restricted to imbalanced diets, they employ regulatory rules that govern the extent to which nutrients occurring in excess or deficit are eaten. Insect herbivores also regularly encounter allelochemicals as they eat, and recent work indicates the effect an allelochemical has on nutrient regulation, and insect herbivore performance, is modified depending on a food's nutrient composition. Comparative studies of nutrient regulation suggest coexisting generalist herbivores occupy unique nutritional feeding niches, and work with pathogens and parasitoids has revealed the manner in which top-down pressures influence patterns of nutrient intake. Insect herbivores regulate their nutrient intake using pre- and postingestive mechanisms, plus learning, and there is evidence that some of these mechanisms are shaped by natural selection.
Use of labeled oral minimal model to measure hepatic insulin sensitivity
Authors: Man Chiara Dalla , Toffolo Gianna , Basu Rita , Rizza Robert A. , Cobelli Claudio
Published: September 2008

The ability to accurately quantify indexes of the individual role of glucose (GEL) and insulin (SIL) in the suppression of endogenous glucose production (EGP) would improve the understanding of liver metabolism. Measuring these indexes during an IVGTT by minimal modeling of tracer labeled and unlabeled glucose data is often unreliable, possibly due to an inadequate description of EGP included in the Minimal Model. Moreover, a validation of the assumptions of the Minimal Model on EGP data has never been done. Recently, Krudys et al. (Krudys KM, Dodds MG, Nissen SM, Vicini P. Am J Physiol Endocrinol Metab 288: E1038–E1046, 2005) have proposed a PK/PD (pharmacokinetic/pharmacodynamic) model of the EGP profile that occurs during an intravenous glucose tolerance test (IVGTT); however, this model has also not been validated. The aim of this study was thus to test the Minimal Model, the PK/PD model, and six alternative EGP descriptions on recent model-independent EGP data of 20 subjects obtained with a triple-tracer meal protocol. Model performance was compared in terms of data fit, precision of the estimated parameters, and physiological plausibility. Neither the PK/PD nor the traditional Minimal Model were able to accurately describe EGP data or provide reliable estimates of the indexes. In contrast, one of the new models performed best by showing a good fit and providing accurate and precise estimates of hepatic sensitivity indexes: GEL = 0.013 ± 0.001 dl·kg−1·min−1; SIL = 5.34 ± 0.47 10−4 dl·kg−1·min−1 per μU/ml (42 and 34%, respectively, of total sensitivity indexes GETOT and SITOT). Although this model requires further validation, it has the potential to improve our understanding of the role of the liver in pathophysiological states.