bluuebunny/crossref_metadata_2025 huggingface dataset:
ACCEPTANCE SAMPLING PLANS FOR BIRNBAUM-SAUNDERS DISTRIBUTION UNDER TRUNCATED LIFE TESTS
Authors: WU CHENG-JU , TSAI TZONG-RU
Published: December 2005

For modeling fatigue data, satatistical distributions are often used because the lifetimes of a fatiguing material can vary due to manufacturing variation or random flaws in the material. One of the popular distributions to describe the number of stress cycles until failure, or analogously, time to failure is the Birnbaum-Saunders distribution. If the lifetimes of products have the Birnbaum-Saunders distribution and a life test is conducted, one objective of the test is to accept the lot when the test shows that the mean life of products exceeds the standard; otherwise, we reject the lot if the test shows that the mean life of products below the standard. Frequently, it might time consuming to wait until all the products fail in a life test if the lifetimes of products are high. In this paper, a truncated life test is proposed to the Birnbaum-Saunders life data, which can save the testing time. An algorithm is provided to obtain the sampling plans based on the truncated life test. Moreover, some useful tables are provided for the sampling plans under Birnbaum-Saunders distribution.
MICROSCOPIC MODEL OF SOFTWARE BUG DYNAMICS: CLOSED SOURCE VERSUS OPEN SOURCE
Authors: CHALLET DAMIEN , DU YANN LE
Published: December 2005

We introduce a simple microscopic description of software bug dynamics where users, programmers and a maintainer of a given program interact through bug creation, detection and correction. When the program is written from scratch, the first phase of development is characterized by a fast decline of the number of bugs, followed by a slow phase where most bugs have been fixed, hence, are hard to find. Releasing immediately bug fixes speeds up the debugging process, which substantiates bazaar open-source methodology. We provide a mathematical analysis that supports our numerical simulations. Finally, we apply our model to Linux history and determine the existence of a lower bound to the quality of its programmers.
PROBABILITY VERSUS STATISTICAL MODELING: EXAMPLES FROM FATIGUE LIFE PREDICTION
Authors: HARLOW D. GARY
Published: December 2005

Probability analyses are increasingly being used for reliability and durability assessments for life prediction of engineered components and systems. Nevertheless, many of the current analyses are predominately statistical rather than probabilistic. Fatigue life prediction has historically been based on the safe-life or the crack growth approaches, both of which are empirically based. Consequently, they do not adequately reflect long-term operating conditions, or identify the sources and extent of their contributions to variability. A comparison between probability and statistical approaches for fatigue life prediction is developed herein. Using simple crack growth models, the variability inherent in S-N response can be related to key random variables that are readily identified in the models. The identification and quantification of these variables are paramount for predicting fatigue lives. The effectiveness of probability modeling compared to statistical methodologies is shown through the analysis of an extensive set of S-N data for 2024-T4 aluminum alloy. Subsequently, the probability approach is demonstrated with S-N data for SUJ2 steel, in which two distinct failure modes are operative. Variability associated with manufacturing and material variables are considered. The adoption of this technique to put life prediction on a sound scientific and probabilistic basis is recommended.
CHARACTERIZATION AND APPROXIMATION OF VALUE FUNCTIONS OF DIFFERENTIAL GAMES WITH MAXIMUM COST IN INFINITE HORIZON
Authors: DI MARCO S. , RAPAPORT A.
Published: December 2005

Value functions of differential games with L∞ criterion over infinite horizon are known to possess poor regularity. As an alternative to generalized solutions of the Isaacs equation, that usually requires some regularity properties, we propose a characterization of the value functions using the integral form of the Isaacs equation. We prove, without any regularity assumption, that value functions are the lowest super-solution and the largest element of a special set of sub-solutions, of the dynamic programming equation. We characterize also the limits of finite horizon value functions, and propose an approximation scheme in terms of iterations of an infinitesimal operator defined over the set of Lipschitz continuous functions. The images of this operator can be characterized by generalized solutions of a classical Isaacs equation.

We illustrate these results on a example, whose value functions can be determined analytically.
SUSTAINABILITY OF COOPERATION OVERTIME IN LINEAR-QUADRATIC DIFFERENTIAL GAMES
Authors: JØRGENSEN STEFFEN , MARTÍN-HERRÁN GUIOMAR , ZACCOUR GEORGES
Published: December 2005

This note deals with time-consistency and agreeability, two dynamic individual rationality concepts, in special linear-quadratic differential games. Conditions ensuring their satisfaction are derived and a link between sustainability of cooperation and fair sharing of cooperation surplus is established.
POTENTIAL MAXIMIZATION AND COALITION GOVERNMENT FORMATION
Authors: GARRATT ROD , PARCO JAMES E. , QIN CHENG-ZHONG , RAPOPORT AMNON
Published: December 2005

A model of coalition government formation is presented in which inefficient, non-minimal winning coalitions may form in Nash equilibrium. Predictions for five games are presented and tested experimentally. The experimental data support potential maximization as a refinement of Nash equilibrium. In particular, the data support the prediction that non-minimal winning coalitions occur when the distance between policy positions of the parties is small relative to the value of forming the government. These conditions hold in games 1, 3, 4 and 5, where subjects played their unique potential-maximizing strategies 91, 52, 82 and 84 percent of the time, respectively. In the remaining game (Game 2) experimental data support the prediction of a minimal winning coalition. Players A and B played their unique potential-maximizing strategies 84 and 86 percent of the time, respectively, and the predicted minimal-winning government formed 92 percent of the time (all strategy choices for player C conform with potential maximization in Game 2). In Games 1, 2, 4 and 5 over 98 percent of the observed Nash equilibrium outcomes were those predicted by potential maximization. Other solution concepts including iterated elimination of weakly dominated strategies and strong/coalition-proof Nash equilibrium are also tested.
THE DUTTA-RAY SOLUTION ON THE CLASS OF CONVEX GAMES: A GENERALIZATION AND MONOTONICITY PROPERTIES
Authors: HOUGAARD JENS LETH , PELEG BEZALEL , ØSTERDAL LARS PETER
Published: December 2005

This paper considers generalized Lorenz-maximal solutions in the core of a convex TU-game and demonstrates that such solutions satisfy coalitional monotonicity and population monotonicity.
COOPERATION AND COMPETITION: LEARNING OF STRATEGIES AND EVOLUTION OF PREFERENCES IN PRISONERS' DILEMMA AND HAWK-DOVE GAMES
Authors: POSSAJENNIKOV ALEX
Published: December 2005

By means of simulations I investigate a two-speed dynamic on strategies and preferences in prisoners' dilemmas and in hawk-dove games. Players learn strategies according to their preferences while evolution leads to a change in the preference composition. With complete information about the preferences of the opponent, cooperation in prisoners' dilemmas is achieved temporarily, with "reciprocal" preferences. In hawk-dove games, a symmetric correlated strategy profile is played that does not place any weight on mutual restraint. Among preferences only "hawkish" preferences and "selfish" preferences survive. With incomplete information, the symmetric equilibrium of the game is played. In prisoners' dilemmas only "selfish" and "reciprocal" preferences survive. In hawk-dove games all preferences are present in the medium run.
BECKMANN'S EDGEWORTH-BERTRAND DUOPOLY EXAMPLE REVISITED
Authors: CHEVIAKOV ALEXEI F. , HARTWICK JOHN M.
Published: December 2005

In the Edgeworth-Bertrand price game, each player has a capacity output, faces the same market demand, and calls out a price. The high-price caller gets some residual market at her price. The low-price caller gets her capacity at her price or all of the market. We re-work Beckmann's closed form solution to his symmetric version of this game, mostly in mixed strategies, and observe that expected price played by a player declines with the size of her exogenously given capacity.
UNCERTAINTY OF THE SHAPLEY VALUE
Authors: KARGIN VLADISLAV
Published: December 2005

This paper defines a measure of bargaining uncertainty that quantifies Roth's concept of strategic risk. It shows how this measure can be used for checking reliability of the Shapley value in cost allocation problems and in the theory of competitive equilibrium. Salient properties of the new measure are investigated and illustrated by examples of majority voting and market games and by a cost allocation problem from epidemiology.
SOLUTION UNIQUENESS IN A CLASS OF CURRENCY CRISIS GAMES
Authors: BAUER CHRISTIAN
Published: December 2005

A common feature of many speculative attack models on currencies is the existence of multiple equilibrium solutions. When choosing the equilibrium strategy, a trader faces Knightian uncertainty about the rational choice of the other traders. We show that the concept of Choquet expected utility maximization under Knightian uncertainty leads to unique equilibria. In games of incomplete information the optimal strategy maximizes the expected utility with respect to a two-dimensional information: environment and rationality. We define a new concept of equilibria, the Choquet-expected-Nash-equilibria, which allows the analysis of decisions under uncertainty, which result in multiple equilibria in standard analysis.

We provide uniqueness theorems for a wide class of incomplete information games including global games and apply them to fairly general currency attack models. The uniqueness of the equilibrium remains valid for arbitrary noise distributions, positively correlated signals, the existence of large traders, individual payoff functions, and for the case that non attacking traders suffer a loss in case of a successful attack, as is the case for investors in the attacked country.
A NEW CHARACTERIZATION OF THE BANZHAF INDEX OF POWER
Authors: BARUA RANA , CHAKRAVARTY SATYA R. , ROY SONALI
Published: December 2005

This paper develops a new axiomatic characterization of the Banzhaf index of power using four axioms from four different contributions to the area. A nice feature of the characterization is independence of the axioms showing importance of each of them in the exercise.
Novel application of the “doubly labeled” water method: measuring CO2production and the tissue-specific dynamics of lipid and protein in vivo
Authors: Bederman Ilya R. , Dufner Danielle A. , Alexander James C. , Previs Stephen F.
Published: December 2005

The partitioning of whole body carbon flux between fat and lean compartments affects body composition. We hypothesized that it is possible to simultaneously determine whole body carbon (energy) balance and the dynamics of lipids and proteins in specific tissues in vivo. Growing C57BL/6J mice fed a high-fat low-carbohydrate diet were injected with a bolus of “doubly labeled” water (i.e.,2H2O and H218O). The rate of CO2production was determined from the difference between the elimination rates of2H and18O from body water. The rates of synthesis and degradation of triglycerides extracted from epididymal fat pads and of proteins extracted from heart muscle were determined by mathematically modeling the2H labeling of triglyceride-bound glycerol and protein-bound alanine, respectively. We found that mice were in positive carbon balance (∼20% retention per day) and accumulated lipid in epididymal fat pads (∼9 μmol triglyceride accumulated per day). This is consistent with the fact that mice were studied during a period of growth. Modeling the2H labeling of triglycerides revealed a substantial rate of lipid breakdown during this anabolic state (equivalent to ∼25% of the newly synthesized triglyceride). We found equal rates of protein synthesis and breakdown in heart muscle (∼10% of the pool per day), consistent with the fact that the heart muscle mass did not change. In total, these findings demonstrate a novel application of the doubly labeled water method. Utilization of this approach, especially in unique rodent models, should facilitate studies aimed at quantifying the efficacy of interventions that modulate whole body carbon balance and lipid flux while in parallel determining their impact on (cardiac) muscle protein turnover. Last, the simplicity of administering doubly labeled water and collecting samples allows this method to be used in virtually any laboratory setting.
Molecular mechanism of 1,25-dihydroxyvitamin D3inhibition of adipogenesis in 3T3-L1 cells
Authors: Kong Juan , Li Yan Chun
Published: December 2005

We have investigated the molecular mechanism whereby 1,25-dihydroxyvitamin D3[1,25(OH)2D3] inhibits adipogenesis in vitro. 1,25(OH)2D3blocks 3T3-L1 cell differentiation into adipocytes in a dose-dependent manner; however, the inhibition is ineffective 24–48 h after the differentiation is initiated, suggesting that 1,25(OH)2D3inhibits only the early events of the adipogenic program. Treatment of 3T3-L1 cells with 1,25(OH)2D3does not block the mitotic clonal expansion or C/EBPβ induction; rather, 1,25(OH)2D3blocks the expression of C/EBPα, peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein-1, and other downstream adipocyte markers. The inhibition by 1,25(OH)2D3is reversible, since removal of 1,25(OH)2D3from the medium restores the adipogenic process with only a temporal delay. Interestingly, although the vitamin D receptor (VDR) protein is barely detectable in 3T3-L1 preadipocytes, its levels are dramatically increased during the early phase of adipogenesis, peaking at 4–8 h and subsiding afterward throughout the rest of the differentiation program; 1,25(OH)2D3treatment appears to stabilize the VDR protein levels. Consistently, adenovirus-mediated overexpression of human (h) VDR in 3T3-L1 cells completely blocks the adipogenic program, confirming that VDR is inhibitory. Inhibition of adipocyte differentiation by 1,25(OH)2D3is ameliorated by troglitazone, a specific PPARγ antagonist; conversely, hVDR partially suppresses the transacting activity of PPARγ but not of C/EBPβ or C/EBPα. Moreover, 1,25(OH)2D3markedly suppresses C/EBPα and PPARγ mRNA levels in mouse epididymal fat tissue culture. Taken together, these data indicate that the blockade of 3T3-L1 cell differentiation by 1,25(OH)2D3occurs at the postclonal expansion stages and involves direct suppression of C/EBPα and PPARγ upregulation, antagonization of PPARγ activity, and stabilization of the inhibitory VDR protein.
Attenuated corticosterone response to chronic ACTH stimulation in hepatic lipase-deficient mice: evidence for a role for hepatic lipase in adrenal physiology
Authors: Dichek Helén L. , Agrawal Nalini , Andaloussi Nazim El , Qian Kun
Published: December 2005

Hepatic lipase (HL), a liver-expressed lipolytic enzyme, hydrolyzes triglycerides and phospholipids in lipoproteins and promotes cholesterol delivery through receptor-mediated whole particle and selective cholesterol uptake. HL activity also occurs in the adrenal glands, which utilize lipoprotein cholesterol to synthesize glucocorticoids in response to pituitary ACTH. It is likely that the role of adrenal HL is to facilitate delivery of exogenous cholesterol for glucocorticoid synthesis. On this basis, we hypothesized that HL deficiency would blunt the glucocorticoid response to ACTH. Furthermore, because exogenous cholesterol also is derived from the LDL receptor (LDLR) pathway, we hypothesized that LDLR deficiency would blunt the response to ACTH. To test these hypotheses, we compared the corticosterone response to eight daily ACTH injections in HL-deficient ( hl−/−), LDLR-deficient ( Ldlr−/−), and HL- and LDLR-doubly deficient ( Ldlr−/−hl−/−) mice with that in wild-type ( WT) mice. Plasma corticosterone levels were measured on days 2, 5, and 8. Differences in plasma corticosterone levels between genotypes were analyzed by Kruskal-Wallis one-way ANOVA on ranks and pairwise multiple comparisons by Dunn’s test. Our results demonstrate a trend toward reductions in plasma corticosterone levels on day 2 and significant reductions on day 5 and day 8 in the knockout models. Thus, on day 5, plasma corticosterone levels were reduced by 57, 70, and 73% (all P < 0.05) and on day 8 by 76, 59, and 63% (all P < 0.05) in hl−/−, Ldlr−/−, and Ldlr−/−hl−/−mice, respectively. These results demonstrate that HL deficiency, like LDLR deficiency, blunts the adrenal response to chronic ACTH stimulation and suggest a novel role for HL in adrenal physiology.
DHT and testosterone, but not DHEA or E2, differentially modulate IGF-I, IGFBP-2, and IGFBP-3 in human prostatic stromal cells
Authors: Le Hanh , Arnold Julia T. , McFann Kimberly K. , Blackman Marc R.
Published: December 2005

Prostate cancer is one of the four most common cancers in the United States, affecting one of six men. Increased serum levels of androgens and IGF-I are associated with an augmented risk of prostate cancer. Dihydrotestosterone (DHT) and testosterone (T) stimulate prostate cancer cell growth, development, and function, whereas the effects of DHT and T in prostate stromal cells, and of dehydroepiandrosterone (DHEA) in prostate cancer or stromal cells, are uncertain. We investigated the actions of DHT, T, DHEA, and estradiol (E2) on insulin-like growth factor (IGF)-I, IGF-II, IGF-I receptor (R), IGF-binding protein (IGFBP)-2, IGFBP-3, and IGFBP-5 in primary cultures of human prostatic stromal cells by assessing cell proliferation, mRNA expression, and protein secretion by MTT growth assay, quantitative real-time PCR, and ELISA, respectively. DHT and T each increased IGF-I (7-fold) and decreased IGFBP-3 (2-fold) mRNA expression and protein secretion in a dose- and time-dependent manner and increased IGFBP-2 (2-fold) mRNA in a dose- and time-dependent manner. DHEA and E2did not significantly alter these measures. Flutamide abolished the DHT-modulated increases in IGF-I and IGFBP-2, suggesting that the influences of DHT and T on these measures were androgen receptor mediated. None of the four steroids significantly affected IGF-IR, IGF-II, or IGFBP-5 mRNA levels or stromal cell proliferation. The effects of DHT on IGF-I, IGFBP-2, and IGFBP-3 were more pronounced in stromal cultures that did not express desmin. These data suggest that DHT and T promote prostate growth partly via modulation of the stromal cell IGF axis, with potential paracrine effects on prostate epithelial cells.
TGF-β1-induced EMT can occur independently of its proapoptotic effects and is aided by EGF receptor activation
Authors: Docherty Neil G. , O'Sullivan Orfhlaith E. , Healy Declan A. , Murphy Madeline , O'Neill Amanda J. , Fitzpatrick John M. , Watson R. William G.
Published: December 2005

Apoptosis and epithelial-mesenchymal transdifferentiation (EMT) occur in stressed tubular epithelial cells and contribute to renal fibrosis. Transforming growth factor (TGF)-β1promotes these responses and we examined whether the processes were interdependent in vitro. Direct (caspase inhibition) and indirect [epidermal growth factor (EGF) receptor stimulation] strategies were used to block apoptosis during TGF-β1stimulation, and the subsequent effect on EMT was assessed. HK-2 cells were exposed to TGF-β1with or without preincubation with ZVAD-FMK (pan-caspase inhibitor) or concomitant treatment with EGF plus or minus preincubation with LY-294002 (PI3-kinase inhibitor). Cells were then assessed for apoptosis and proliferation by flow cytometry, crystal violet assay, and Western blotting. Markers of EMT were assessed by microscopy, immunofluorescence, real-time RT-PCR, Western blotting, PAI-1 reporter assay, and collagen gel contraction assay. TGF-β1caused apoptosis and priming for staurosporine-induced apoptosis. This was blocked by ZVAD-FMK. However, ZVAD-FMK did not prevent EMT following TGF-β1treatment. EGF inhibited apoptosis and facilitated TGF-β1induction of EMT by increasing proliferation and accentuating E-cadherin loss. Additionally, EGF significantly enhanced TGF-β1-induced collagen I gel contraction. EGF increased Akt phosphorylation during EMT, and the prosurvival effect of this was confirmed using LY-294002, which reduced EGF-induced Akt phosphorylation and reversed its antiapoptotic and proproliferatory effects. TGF-β1induces EMT independently of its proapoptotic effects. TGF-β1and EGF together lead to EMT. EGF increases proliferation and resistance to apoptosis during EMT in a PI3-K Akt-dependent manner. In vivo, EGF receptor activation may assist in the selective survival of a transdifferentiated, profibrotic cell type.
Functional influence ofN-glycosylation in OCT2-mediated tetraethylammonium transport
Authors: Pelis Ryan M. , Suhre Wendy M. , Wright Stephen H.
Published: December 2005

OCT2, an organic cation transporter critical for removal of many drugs and toxins from the body, contains consensus sites for N-glycosylation at amino acid position 71, 96, and 112. However, the extent to which these sites are glycosylated by the cell, and the influence glycosylation has on OCT2 function, remains unknown. To address these issues, the acquisition of N-glycosylation was disrupted by mutating the amino acid asparagine (N) to glutamine (Q) at these sites in the rabbit ortholog of OCT2, which was expressed in Chinese hamster ovary cells. Disruption of N-glycosylation followed by Western blotting indicated that each site is indeed glycosylated and that OCT2 contains no other sites of N-glycosylation. Plasma membrane expression (determined by surface biotinylation) of the N112Q mutant, but not N71Q or N96Q mutants, was fourfold lower than that of wild-type OCT2, and unglycosylated OCT2 (N71Q/N96Q/N112Q) was sequestered in an unidentified intracellular compartment. The N71Q, N96Q, and N112Q mutants had a higher affinity (∼2-fold) for tetraethylammonium (TEA). Maximum transport rate was reduced in the N96Q (3-fold) and N112Q (5-fold) mutants, but not the N71Q mutant, and unglycosylated OCT2 failed to transport TEA (associated with its absence in the plasma membrane). Whereas the reduction in maximum transport rate of the N112Q mutant is consistent with its reduced plasma membrane expression, the lower rate of the N96Q mutant, which appeared to traffic properly, suggests that glycosylation at N96 increases the transporter turnover number.
Ca2+ Influx, But Not Ca2+ Release From Internal Stores, Is Required for the PACAP-Induced Increase in Excitability in Guinea Pig Intracardiac Neurons
Authors: Tompkins John D. , Hardwick Jean C. , Locknar Sarah A. , Merriam Laura A. , Parsons Rodney L.
Published: December 2005

Mechanisms modulating the pituitary adenylate cyclase activating polypeptide (PACAP)-induced increase in excitability have been studied using dissociated guinea pig intrinsic cardiac neurons and intact ganglion preparations. Measurements of intracellular calcium (Ca2+) with the fluorescent Ca2+ indicator dye fluo-3 indicated that neither PACAP nor vasoactive intestinal polypeptide (VIP) at either 100 nM or 1 μM produced a discernible elevation of intracellular Ca2+ in dissociated intracardiac neurons. For neurons in ganglion whole mount preparations kept in control bath solution, local application of PACAP significantly increased excitability, as indicated by the number of action potentials generated by long depolarizing current pulses. However, in a Ca2+-deficient solution in which external Ca2+ was replaced by Mg2+ or when cells were bathed in control solution containing 200 μM Cd2+, PACAP did not enhance action potential firing. In contrast, in a Ca2+-deficient solution with Ca2+ replaced by strontium (Sr2+), PACAP increased excitability. PACAP increased excitability in cells treated with a combination of 20 μM ryanodine and 10 mM caffeine to interrupt release of Ca2+ from internal stores. Experiments using fluo-3 showed that ryanodine/caffeine pretreatment eliminated subsequent caffeine-induced Ca2+ release from intracellular stores, whereas exposure to the Ca2+-deficient solution did not. In dissociated intracardiac neurons voltage clamped with the perforated patch recording technique, 100 nM PACAP decreased the voltage-dependent barium current ( IBa). These results show that, in the guinea pig intracardiac neurons, the PACAP-induced increase in excitability apparently requires Ca2+ influx through Cd2+-sensitive calcium permeable channels other than voltage-dependent Ca2+ channels, but not Ca2+ release from internal stores.
Genomic annotation of 15,809 ESTs identified from pooled early gestation human eyes
Authors: Choy K. W. , Wang C. C. , Ogura A. , Lau T. K. , Rogers M. S. , Ikeo K. , Gojobori T. , Lam D. S. C. , Pang C. P.
Published: December 2005

To complement cDNA libraries from the human eye at early gestation and to discover candidate genes associated with early ocular development, we used freshly dissected human eyeballs from week 9–14 of gestation to construct the early human fetal eye cDNA library. A total of 15,809 clones were isolated and sequenced from the unamplified and unnormalized library. We screened 11,246 good-quality ESTs, leading to the identification of 5,534 nonredundant clusters. Among them, 4,010 (72%) genes matched in the human protein database (Ensembl). The remaining 28% (1,524) corresponded to potentially novel or previously unidentified ESTs. We used BLASTX to compare our EST data with eight organisms and found common expression of a high portion of genes: Caenorhabditis briggsae (26%), Caenorhabditis elegans (27%), Anopheles gambiae (37%), Drosophila melanogaster (32%), Danio rerio (42%), Fugu rubripes (49%), Rattus norvegicusvalitus (52%), and Mus musculus (59%). Nevertheless, 48% (2,680 of 5,534) of the genes expressed in the early developing eye were not shared with current NEIBank human eye cDNA data. In addition, eight known retinal disease genes existed in our ESTs. Among them, six ( COL11A1, BBS5, PDE6B, OAT, VMD2, and PGK1) were conserved among the genomes of other organisms, indicating that our annotated EST set provides not only a valuable resource for gene discovery and functional genomic analysis but also for phylogenetic analysis. Our foremost early gestation human eye cDNA library could provide detailed comparisons across species to identify physiological functions of genes and to elucidate evolutionary mechanisms.
Distinct gene expression profiles in adult mouse heart following targeted MAP kinase activation
Authors: Mitchell Scherise , Ota Asuka , Foster William , Zhang Bin , Fang Zixing , Patel Shilpa , Nelson Stanley F. , Horvath Steve , Wang Yibin
Published: December 2005

Three major MAP kinase signaling cascades, ERK, p38, and JNK, play significant roles in the development of cardiac hypertrophy and heart failure in response to external stress and neural/hormonal stimuli. To study the specific function of each MAP kinase branch in adult heart, we have generated three transgenic mouse models with cardiac-specific and temporally regulated expression of activated mutants of Ras, MAP kinase kinase (MKK)3, and MKK7, which are selective upstream activators for ERK, p38, and JNK, respectively. Gene expression profiles in transgenic adult hearts were determined using cDNA microarrays at both early (4–7 days) and late (2–4 wk) time points following transgene induction. From this study, we revealed common changes in gene expression among the three models, particularly involving extracellular matrix remodeling. However, distinct expression patterns characteristic for each pathway were also identified in cell signaling, growth, and physiology. In addition, genes with dynamic expression differences between early vs. late stages illustrated primary vs. secondary changes on MAP kinase activation in adult hearts. These results provide an overview to both short-term and long-term effects of MAP kinase activation in heart and support some common as well as unique roles for each MAP kinase cascade in the development of heart failure.
Regulation of hypothalamic gene expression by glucocorticoid: implications for energy homeostasis
Authors: Nishida Yuichiro , Yoshioka Mayumi , St-Amand Jonny
Published: December 2005

The present study investigated the hypothalamic gene expressions regulated by glucocorticoids (GC), key hormones in energy homeostasis. Using the serial analysis of gene expression (SAGE) method, we studied the effects of adrenalectomy (ADX) and GC on the transcriptomes of mouse hypothalamus. Approximately 180,000 SAGE tags, which correspond to 50,000 tag species, were isolated from each group of intact or adrenalectomized mice as well as 1, 3, and 24 h after GC injection. ADX upregulated diazepam binding inhibitor gene expression while downregulating vomeronasal 1 receptor D4, genes involved in mitochondrial phosphorylation (cytochrome- c oxidase 1 and NADH dehydrogenase 3), 3β-hydroxysteroid dehydrogenase-1, and prostaglandin D2synthase. GC increased the gene expression levels of dehydrogenase/reductase member 3, prostaglandin D2synthase, solute carrier family 4 member 4, and five cytoskeletal proteins including myosin light chain phosphorylatable fast and troponin C2 fast. On the other hand, GC reduced the mRNA levels of calmodulin 1 and expressed sequence tag similar to calmodulin 2, ATP synthase F0 subunit 6, and solute carrier family 4 member 3. Moreover, 7 uncharacterized and 43 novel transcripts were modulated by ADX and GC. The present study has identified genes that may regulate hypothalamic systems governing energy balance in response to ADX and GC.
Respiratory Tract Mucin Genes and Mucin Glycoproteins in Health and Disease
Authors: Rose Mary Callaghan , Voynow Judith A.
Published: December 2005

This review focuses on the role and regulation of mucin glycoproteins (mucins) in airway health and disease. Mucins are highly glycosylated macromolecules (≥50% carbohydrate, wt/wt). MUC protein backbones are characterized by numerous tandem repeats that contain proline and are high in serine and/or threonine residues, the sites of O-glycosylation. Secretory and membrane-tethered mucins contribute to mucociliary defense, an innate immune defense system that protects the airways against pathogens and environmental toxins. Inflammatory/immune response mediators and the overproduction of mucus characterize chronic airway diseases: asthma, chronic obstructive pulmonary diseases (COPD), or cystic fibrosis (CF). Specific inflammatory/immune response mediators can activate mucin gene regulation and airway remodeling, including goblet cell hyperplasia (GCH). These processes sustain airway mucin overproduction and contribute to airway obstruction by mucus and therefore to the high morbidity and mortality associated with these diseases. Importantly, mucin overproduction and GCH, although linked, are not synonymous and may follow from different signaling and gene regulatory pathways. In section i, structure, expression, and localization of the 18 human MUC genes and MUC gene products having tandem repeat domains and the specificity and application of MUC-specific antibodies that identify mucin gene products in airway tissues, cells, and secretions are overviewed. Mucin overproduction in chronic airway diseases and secretory cell metaplasia in animal model systems are reviewed in section ii and addressed in disease-specific subsections on asthma, COPD, and CF. Information on regulation of mucin genes by inflammatory/immune response mediators is summarized in section iii. In section iv, deficiencies in understanding the functional roles of mucins at the molecular level are identified as areas for further investigations that will impact on airway health and disease. The underlying premise is that understanding the pathways and processes that lead to mucus overproduction in specific airway diseases will allow circumvention or amelioration of these processes.
Signaling Mechanisms Regulating Endothelial Permeability
Authors: Mehta Dolly , Malik Asrar B.
Published: December 2005

The microvascular endothelial cell monolayer localized at the critical interface between the blood and vessel wall has the vital functions of regulating tissue fluid balance and supplying the essential nutrients needed for the survival of the organism. The endothelial cell is an exquisite “sensor” that responds to diverse signals generated in the blood, subendothelium, and interacting cells. The endothelial cell is able to dynamically regulate its paracellular and transcellular pathways for transport of plasma proteins, solutes, and liquid. The semipermeable characteristic of the endothelium (which distinguishes it from the epithelium) is crucial for establishing the transendothelial protein gradient (the colloid osmotic gradient) required for tissue fluid homeostasis. Interendothelial junctions comprise a complex array of proteins in series with the extracellular matrix constituents and serve to limit the transport of albumin and other plasma proteins by the paracellular pathway. This pathway is highly regulated by the activation of specific extrinsic and intrinsic signaling pathways. Recent evidence has also highlighted the importance of the heretofore enigmatic transcellular pathway in mediating albumin transport via transcytosis. Caveolae, the vesicular carriers filled with receptor-bound and unbound free solutes, have been shown to shuttle between the vascular and extravascular spaces depositing their contents outside the cell. This review summarizes and analyzes the recent data from genetic, physiological, cellular, and morphological studies that have addressed the signaling mechanisms involved in the regulation of both the paracellular and transcellular transport pathways.
Function of cGMP-Dependent Protein Kinases as Revealed by Gene Deletion
Authors: Hofmann F. , Feil R. , Kleppisch T. , Schlossmann J.
Published: December 2005

Over the past few years, a wealth of biochemical and functional data have been gathered on mammalian cGMP-dependent protein kinases (cGKs). In mammals, three different kinases are encoded by two genes. Mutant and chimeric cGK proteins generated by molecular biology techniques yielded important biochemical knowledge, such as the function of the NH2-terminal domains of cGKI and cGKII, the identity of the cGMP-binding sites of cGKI, and the substrate specificity of the enzymes. Genetic approaches have proven especially useful for the analysis of the biological functions of cGKs. Recently, some of the in vivo targets and mechanisms leading to changes in neuronal adaptation, smooth muscle relaxation and growth, intestinal water secretion, bone growth, renin secretion, and other important functions have been identified. These data show that cGKs are signaling molecules involved in many biological functions.
Calcium at Fertilization and in Early Development
Authors: Whitaker Michael
Published: December 2005

Fertilization calcium waves are introduced, and the evidence from which we can infer general mechanisms of these waves is presented. The two main classes of hypotheses put forward to explain the generation of the fertilization calcium wave are set out, and it is concluded that initiation of the fertilization calcium wave can be most generally explained in invertebrates by a mechanism in which an activating substance enters the egg from the sperm on sperm-egg fusion, activating the egg by stimulating phospholipase C activation through a src family kinase pathway and in mammals by the diffusion of a sperm-specific phospholipase C from sperm to egg on sperm-egg fusion. The fertilization calcium wave is then set into the context of cell cycle control, and the mechanism of repetitive calcium spiking in mammalian eggs is investigated. Evidence that calcium signals control cell division in early embryos is reviewed, and it is concluded that calcium signals are essential at all three stages of cell division in early embryos. Evidence that phosphoinositide signaling pathways control the resumption of meiosis during oocyte maturation is considered. It is concluded on balance that the evidence points to a need for phosphoinositide/calcium signaling during resumption of meiosis. Changes to the calcium signaling machinery occur during meiosis to enable the production of a calcium wave in the mature oocyte when it is fertilized; evidence that the shape and structure of the endoplasmic reticulum alters dynamically during maturation and after fertilization is reviewed, and the link between ER dynamics and the cytoskeleton is discussed. There is evidence that calcium signaling plays a key part in the development of patterning in early embryos. Morphogenesis in ascidian, frog, and zebrafish embryos is briefly described to provide the developmental context in which calcium signals act. Intracellular calcium waves that may play a role in axis formation in ascidian are discussed. Evidence that the Wingless/calcium signaling pathway is a strong ventralizing signal in Xenopus, mediated by phosphoinositide signaling, is adumbrated. The central role that calcium channels play in morphogenetic movements during gastrulation and in ectodermal and mesodermal gene expression during late gastrulation is demonstrated. Experiments in zebrafish provide a strong indication that calcium signals are essential for pattern formation and organogenesis.
Generalized g‐quasivariational inequality
Authors: Nessah Rabia , Larbani Moussa
Published: December 2005

Suppose that X is a nonempty subset of a metric space E and Y is a nonempty subset of a topological vector space F. Let g : X → Y and ψ : X × Y → ℝ be two functions and let S : X → 2Y and be two maps. Then the generalized g‐quasivariational inequality problem (GgQVI) is to find a point and a point such that and . In this paper, we prove the existence of a solution of (GgQVI).
The envelope of a subcategory in topology and group theory
Authors: Ayache Ahmed , Echi Othman
Published: December 2005

A collection of results are presented which are loosely centered
around the notion of reflective subcategory. For example, it is
shown that reflective subcategories are orthogonality classes,
that the morphisms orthogonal to a reflective subcategory are
precisely the morphisms inverted under the reflector, and that
each subcategory has a largest “envelope” in the ambient
category in which it is reflective. Moreover, known results
concerning the envelopes of the category of sober spaces, spectral
spaces, and jacspectral spaces, respectively, are summarized and
reproved. Finally, attention is focused on the envelopes of one‐object
subcategories, and examples are considered in the category of groups.
Existence of solutions for a family of polyharmonic andbiharmonic equations
Authors: Hesaaraki M. , Raessi B.
Published: December 2005

We consider a family of polyharmonic problems of the form
(−Δ) mu = g(x, u) in Ω, Dαu = 0 on ∂Ω, where Ω ⊂ ℝn is a bounded domain, g(x, ⋅) ∈ L∞(Ω), and
|α| < m. By using the fibering method, we obtain some results about the existence of solution and its multiplicity under certain assumptions on
g. We also consider a family of biharmonic problems of the form
Δ2u + (Δϕ + |∇ϕ|2)Δu + 2∇ϕ · ∇Δu = g(x, u), where , and Ω, g, and the boundary condition are the same as above. For this problem, we prove the existence and multiplicity of solutions too.
A class of inequalities relating degrees of adjacent nodes to the average degree in edge‐weighteduniform hypergraphs
Authors: Johnson P. D. , Mohapatra R. N.
Published: December 2005

In 1986, Johnson and Perry proved a class of inequalities for
uniform hypergraphs which included the following: for any such
hypergraph, the geometric mean over the hyperedges of the
geometric means of the degrees of the nodes on the hyperedge is
no less than the average degree in the hypergraph, with equality
only if the hypergraph is regular. Here, we prove a wider class of
inequalities in a wider context, that of edge‐weighted uniform
hypergraphs.
Limit theorems for randomly selected adjacent order statistics from a Pareto distribution
Authors: Adler André
Published: December 2005

Consider independent and identically distributed random variables
{Xnk, 1 ≤ k ≤ m, n ≥ 1} from the Pareto distribution. We randomly select two adjacent order statistics from each row, Xn(i) and Xn(i+1), where 1 ≤ i ≤ m − 1. Then, we test to see whether or not strong and weak laws of large numbers with nonzero limits for weighted sums of the random variables
Xn(i+1)/Xn(i) exist, where we place a prior distribution on the selection of each of these possible pairs of order statistics.
A class of ℐ‐conservative matrices
Authors: Çakan Celal , Çoşkun Hüsamettin
Published: December 2005

By using the concept of ℐ‐convergence defined by Kostyrko et al. in 2001, the ℐ‐limit superior of real sequences was introduced and the inequality
ℐ − lim⁡sup⁡(Ax) ≤ ℐ − lim⁡sup⁡(x) for all x ∈ ℓ∞ was studied by Demirci in 2001. In this paper, we have characterized
a class of ℐ‐conservative matrices by studying some new inequalities related to the ℐ‐limit superior.
A q‐analog of Euler′s decomposition formula forthe double zeta function
Authors: Bradley David M.
Published: December 2005

The double zeta function was first studied by Euler in response to
a letter from Goldbach in 1742. One of Euler′s results for this
function is a decomposition formula, which expresses the product
of two values of the Riemann zeta function as a finite sum of
double zeta values involving binomial coefficients. Here, we
establish a q‐analog of Euler′s decomposition formula. More
specifically, we show that Euler′s decomposition formula can be
extended to what might be referred to as a “double q‐zeta
function” in such a way that Euler′s formula is recovered in the
limit as q tends to 1.
The dock problem revisited
Authors: Chakrabarti A. , Mandal B. N. , Gayen Rupanwita
Published: December 2005

The well‐known semi‐infinite dock problem of the theory of
scattering of surface water waves is reexamined and known results
are recovered by utilizing a Fourier type of analysis, giving rise
to Carleman‐type singular integral equations over semi‐infinite
ranges.
On Riemannian manifolds endowed with a locally conformalcosymplectic structure
Authors: Mihai Ion , Rosca Radu , Ghişoiu Valentin
Published: December 2005

We deal with a locally conformal cosymplectic manifold
M(φ, Ω, ξ, η, g) admitting a conformal contact quasi‐torse‐forming vector field T. The presymplectic 2‐form Ω is a locally conformal cosymplectic 2‐form. It is shown that T is a 3‐exterior concurrent vector field. Infinitesimal transformations of the Lie algebra of ∧M are investigated. The Gauss map of the hypersurface Mξ normal to ξ is conformal and Mξ × Mξ is a Chen submanifold of M × M.
The convergence of mean value iteration for a family of maps
Authors: Rhoades B. E. , Şoltuz Ştefan M.
Published: December 2005

We consider a mean value iteration for a family of functions, which corresponds to
the Mann iteration with lim⁡n→∞  αn ≠ 0. We prove convergence results for this iteration when applied to strongly
pseudocontractive or strongly accretive maps.
Flat circle bundles, pullbacks, and the circle madediscrete
Authors: Oprea John , Tanré Daniel
Published: December 2005

We use basic homotopical methods applied to Lie groups
made discrete to prove that the real Euler class of a
circle bundle vanishes if and only if the bundle is flat.
Mappings preserving regular hexahedrons
Authors: Jung Soon-Mo , Kim Byungbae
Published: December 2005

We will prove that if a one‐to‐one mapping f : ℝ3 → ℝ3 preserves regular hexahedrons, then f is a linear isometry up to translation.
Annihilators of nilpotent elements
Authors: Klein Abraham A.
Published: December 2005

Let x be a nilpotent element of an infinite ring R (not necessarily with 1). We prove that A(x)—the two‐sided annihilator of x—has a large intersection with any infinite ideal I of R in the sense that card(A(x)∩I) = cardI. In particular, cardA(x) = cardR; and this is applied to prove that if N is the set of nilpotent elements of R and R ≠ N, then card(R\N) ≥ cardN.
A note on self‐extremal sets in Lp(Ω) spaces
Authors: Nguyen-Khac Viet , Nguyen-Van Khiem
Published: December 2005

We give a necessary condition for a set in Lp(Ω) spaces (1 < p < ∞) to be self‐extremal that partially extends our
previous results to the case of Lp spaces. Examples of self‐extremal sets in Lp(Ω)(1 < p < ∞) are also given.
A sequential Riesz‐like criterion for the Riemann hypothesis
Authors: Báez-Duarte Luis
Published: December 2005

Let . We prove that the Riemann hypothesis is equivalent to ck ≪ k−3/4+ε for all ε > 0; furthermore, we prove that ck ≪ k−3/4 implies that the zeros of ζ(s) are simple. This is closely related to M. Riesz′s criterion which states that
the Riemann hypothesis is equivalent to as x → +∞, for all ε > 0.
Isolation and Characterization of Type I Signal Peptidase ofDifferent Malaria Parasites
Authors: Sharma Sutikshan , Pradhan Arun , Chauhan Virander S. , Tuteja Renu
Published: December 2005

Type I signal peptidases are important membrane‐bound serine
proteases responsible for the cleavage of the signal peptide of
the proteins. These enzymes are unique serine proteases that
carry out catalysis using a serine/lysine catalytic dyad. In the
present study, we report the isolation of type I signal peptidase
from the malaria parasites Plasmodium falciparum,
Plasmodium knowlesi, and Plasmodium yoelii and
some characterization of type I signal peptidase of
Plasmodium falciparum. We show that these enzymes are
homologous to signal peptidases from various sources and also
contain the conserved boxes present in other type I signal
peptidases. The type I signal peptidase from P falciparum
is an intron‐less and a single‐copy gene. The results also show
that the enzyme from Plasmodium falciparum is subject to
self‐cleavage and it has been demonstrated to possess type I
signal peptidase activity in E coli preprotein processing
in vivo by complementation assay. This study will be helpful in
understanding one of the important metabolic pathways “the
secretory pathway” in the parasite and should make an important
contribution in understanding the complex process of protein
targeting in the parasite.
HLA Allele Associations and V‐Beta T‐Lymphocyte Expansions inPatients With Psoriasis, Harboring Toxin‐Producing Staphylococcus aureus
Authors: Ajib Rola , Janbazian Lori , Rahal Elias , Matar Ghassan M. , Zaynoun Shukrallah , Kibbi Abdul-Ghani , Abdelnoor Alexander M.
Published: December 2005

HLA alleles have been associated with psoriasis. Toxin‐producing
strains of Staphylococcus aureus behave as superantigens, and
if present in patients, might play a role in the exacerbation
of psoriatic lesions by activating certain V‐beta (Vβ) T‐lymphocyte subsets. Allele frequencies in 22 patients and 22
controls (alleles determined by DNA/SSP typing) were used to calculate a relative risk
of 4.7 (P < .05) for HLA‐Cw6. S aureus was isolated from the throat of 11
patients. Enterotoxins A and C were detected by agglutination in the culture filtrate of one
isolate. The enterotoxin A and/or C genes were detected by PCR in 9 isolates, and
transcripts were detected by RT‐PCR in 7 of them. None of the isolates from controls
harbored enterotoxin genes. Vβ expansions were detected by RT‐PCR in all 22 patients. Low or
no Vβ expansions were obtained in controls. The association of HLA‐Cw6 with
psoriasis in Lebanese concurs with that reported for other ethnic groups.
Toxin‐producing isolates that colonize patients might play a role in the
exacerbation of psoriatic lesions.