bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic analysis reveals polygenic influences on iron, copper, and zinc in mouse hippocampus with neurobiological implications
Authors: Jones Leslie C. , Beard John L. , Jones Byron C.
Published: January 2008

Fe, Cu, and Zn are of widespread neurobiological importance, but must be regulated closely as too much or too little of these metals can have adverse effects on brain function. Recent evidence from nutritional models notes that the hippocampus is particularly vulnerable to Fe and Zn deficiencies. We recently performed a quantitative trait loci (QTL) analysis as a preliminary step in identifying genes that contribute to natural variation in hippocampal Fe, Cu, and Zn content. We used ICP‐MS to measure the concentrations of these metals in 120‐day‐old mice from 30 strains of the BXD/TY panel. The BXD/Ty recombinant inbred strain panel is well‐suited for complex trait analysis, as all strains are genotyped with a dense marker set and have been phenotyped extensively for neurobehavioral traits and hippocampal gene expression. We observed a wide‐range of hippocampal Fe, Cu, and Zn concentrations across the BXD strains. These concentrations were related to systemic Fe status, but not to Fe, Cu, and Zn elsewhere in the brain. The three metals also showed strong covariance, suggestive of overlap in their regulatory pathways. We identified two QTL, on chromosomes 14 and 9, most strongly associated with Cu but also suggestively associated with Fe (chr. 14) and Zn (chr. 9). We also performed genetic correlational analyses with existing data on these strains and revealed associations with cognitive, anxiety‐related, and alcohol‐related phenotypes. Covariance of these metals with gene expression is also discussed. This work shows that hippocampal Fe, Cu, and Zn are under polygenic influence and that trace metal regulation is associated with hippocampus‐related behaviors. Future work will elucidate the genes underlying the two QTL identified, to aid in identifying homologous genetic variants in human populations, which may underlie altered trace metal homeostasis and related neurological disease. © 2008 Wiley‐Liss, Inc.
Calretinin expression in hilar mossy cells of the hippocampal dentate gyrus of nonhuman primates and humans
Authors: Seress László , Ábrahám Hajnalka , Czéh Boldizsár , Fuchs Eberhard , Léránth Csaba
Published: January 2008

Mossy cells, the major excitatory neurons of the hilus of the dentate gyrus constitutively express calretinin in several rodent species, including mouse and hamster, but not in rats. Several studies suggest that mossy cells of the monkey dentate gyrus are calretinin‐positive, but others have reported mossy cells in monkeys to be devoid of detectable calretinin‐like immunoreactivity. In the present study, the hilar region was investigated throughout the entire longitudinal extent of the hippocampal dentate gyrus in both Old World and New World monkeys, as well as in humans. In the examined four monkey species, mossy cells were found to be calretinin‐positive at the uncal pole and at variable length within the main body of the dentate gyrus but not in the tail part. The associational pathway, formed by axons of mossy cells in the inner dentate molecular layer was calretinin‐positive in more caudal sections, suggesting that mossy cell axon terminals may contain calretinin, whereas mossy cell somata may contain calretinin in a concentration too low to be detected by immunocytochemistry. In contrast, human mossy cells appear to be devoid of calretinin immunoreactivity in both their somata and their axon terminals. Taken together, mossy cells of nonhuman primates and humans exhibit different expression pattern for calretinin whereas they show similarities in neurochemical content, such as the cocaine and amphetamine‐related transcript peptide. © 2008 Wiley‐Liss, Inc.
Distinct classes of pyramidal cells exhibit mutually exclusive firing patterns in hippocampal area CA3b
Authors: Hemond Peter , Epstein Daniel , Boley Angela , Migliore Michele , Ascoli Giorgio A. , Jaffe David B.
Published: January 2008

It is thought that CA3 pyramidal neurons communicate mainly through bursts of spikes rather than so‐called trains of regular firing action potentials. Reports of both burst firing and nonburst firing CA3 cells suggest that they may fire with more than one output pattern. With the use of whole‐cell recording methods we studied the firing properties of rat hippocampal pyramidal neurons in vitro within the CA3b subregion and found three distinct types of firing patterns. Approximately 37% of cells were regular firing where spikes generated by minimal current injection (rheobase) were elicited with a short latency and with stronger current intensities trains of spikes exhibited spike frequency adaptation (SFA). Another 46% of neurons exhibited a delayed onset at rheobase with a weakly‐adapting firing pattern upon stronger stimulation. The remaining 17% of cells showed a burst‐firing pattern, though only elicited in response to strong current injection and spontaneous bursts were never observed. Control experiments indicated that the distinct firing patterns were not due to our particular slicing methods or recording techniques. Finally, computer modeling was used to identify how relative differences in K+ conductances, specifically KC, KM, and KD, between cells contribute to the different characteristics of the three types of firing patterns observed experimentally. © 2008 Wiley‐Liss, Inc.
Introduction of gelatin microspheres into an injectable calcium phosphate cement
Authors: Habraken W. J. E. M. , de Jonge L. T. , Wolke J. G. C. , Yubao L. , Mikos A. G. , Jansen J. A.
Published: January 2008

For tissue engineered bone constructs, calcium phosphate cement (CPC) has a high potential as scaffold material because of its biocompatibility and osteoconductivity. However, in vivo resorption and tissue ingrowth is slow. To address these issues, microspheres can be incorporated into the cement, which will create macroporosity after in situ degradation. The goal of this study was to investigate the handling properties and degradation characteristics of CPC containing gelatin microspheres. Setting time and injectability were determined and an in vitro degradation study was performed. Samples were assayed on mass, compression strength, E‐modulus, and morphology. A supplementary degradation test with gelatin microspheres was performed to investigate the influence of physical conditions inside the cement on microsphere stability. The gelatin microsphere CPCs were easy to inject and showed initial setting times of less than 3 min. After 12‐weeks in vitro degradation no increase in macroporosity was observed, which was supported by the small mass loss and stabilizing mechanical strength. Even a clear densification of the composite was observed. Explanations for the lack of macroporosity were recrystallization of the cement onto or inside the gelatin spheres and a delayed degradation of gelatin microspheres inside the scaffold. The supplementary degradation test showed that the pH is a factor in the delayed gelatin microsphere degradation. Also differences in degradation rate between types of gelatin were observed. Overall, the introduction of gelatin microspheres into CPC renders composites with good handling properties, though the degradation characteristics should be further investigated to generate a macroporous scaffold. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Through‐thickness plasma modification of biodegradable and nonbiodegradable porous polymer constructs
Authors: Safinia Laleh , Wilson Karen , Mantalaris Athanasios , Bismarck Alexander
Published: January 2008

Pure poly(lactide‐co‐glycolide) and polystyrene surfaces are not very suitable to support cell adhesion/spreading owing to their hydrophobic nature and low surface energy. The interior surfaces of large porous 3D scaffolds were modified and activated using radio‐frequency, low‐pressure air plasma. An increase in the wettability of the surface was observed after exposure to air plasma, as indicated by the decrease in the contact angles of the wet porous system. The surface composition of the plasma‐treated polymers was studied using X‐ray photoelectron spectroscopy. pH‐dependent zeta‐potential measurements confirm the presence of an increased number of functional groups. However, the plasma‐treated surfaces have a less acidic character than the original polymer surfaces as seen by a shift in their isoelectric point. Zeta‐potential, as well as contact angle measurements, on 3D scaffolds confirm that plasma treatment is a useful tool to modify the surface properties throughout the interior of large scaffolds. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Bone reaction to nano hydroxyapatite modified titanium implants placed in a gap‐healing model
Authors: Meirelles Luiz , Albrektsson Tomas , Kjellin Per , Arvidsson Anna , Franke‐Stenport Victoria , Andersson Martin , Currie Fredrik , Wennerberg Ann
Published: January 2008

Nanohydroxyapatite materials show similar chemistry to the bone apatite and depending on the underlying topography and the method of preparation, the nanohydroxyapatite may simulate the specific arrangement of the crystals in bone. Hydroxyapatite (HA) and other CaP materials have been indicated in cases in which the optimal surgical fit is not achievable during surgery, and the HA surface properties may enhance bone filling of the defect area. In this study, very smooth electropolished titanium implants were used as substrata for nano‐HA surface modification and as control. One of each implant (control and nano HA) was placed in the rabbit tibia in a surgical site 0.7 mm wider than the implant diameter, resulting in a gap of 0.35 mm on each implant side. Implant stability was ensured by a fixating plate fastened with two side screws. Topographical evaluation performed with an optical interferometer revealed the absence of microstructures on both implants and higher resolution evaluation with AFM showed similar nanoroughness parameters. Surface pores detected on the AFM measurements had similar diameter, depth, and surface porosity (%). Histological evaluation demonstrated similar bone formation for the nano HA and electropolished implants after 4 weeks of healing. These results do not support that nano‐HA chemistry and nanotopography will enhance bone formation when placed in a gap‐healing model. The very smooth surface may have prevented optimal activity of the material and future studies may evaluate the synergic effects of the surface chemistry, micro, and nanotopography, establishing the optimal parameters for each of them. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
In situ formation of hydrogels as vitreous substitutes: Viscoelastic comparison to porcine vitreous
Authors: Swindle Katelyn E. , Hamilton Paul D. , Ravi Nathan
Published: January 2008

The human vitreous is a gelatinous substance predominantly composed of water (97–99%). Vitreous substitutes are needed for treatment of retinal detachments by reapproximating the retina to the back of the eye, or during vitrectomies for maintenance of ocular volume. None of the current substitutes can be used long‐term due to their short retention time, toxicity, or complications such as glaucoma or cataracts. In addition, all of the current compounds have a specific gravity less than water and so are not appropriate for inferior retinal detachments. The viscoelastic properties of the porcine vitreous were analyzed to develop a model for ideal substitutes. Synthetic polymers that form hydrogels in situ were researched for the development of artificial vitreous. In this study, the physical, mechanical, and optical properties of four self‐gelling polyacrylamide copolymeric hydrogels were determined and compared with those of the porcine vitreous. The 2% formulation of high crosslink density, hydrophobically modified hydrogel most closely mimicked the porcine vitreous. The viscoelastic properties of hydrogels capable of being formed in situ were compared to those of the porcine vitreous to determine their efficacy as vitreous substitutes. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Cell migration by a FRS2‐adaptor dependent membrane relocation of ret receptors
Authors: Lundgren T. Kalle , Stenqvist Anna , Scott Rizaldy P. , Pawson Tony , Ernfors Patrik
Published: January 2008

During development neural progenitor cells migrate with extraordinary precision to inhabit tissues and organs far from their initial position. Little is known about the cellular basis for directional guidance by tyrosine kinase receptors (RTKs). RET is a RTK with important functions in guiding the migration of neuronal cells, and RET dysregulation leads to clinical disease such as agangliosis of the colon. We show here that RET migration in neuroepitheliomal and non‐neuronal cells is elicited by the activation of specific signaling pathways initiated by the competitive recruitment of the FRS2 adaptor molecule to tyrosine 1062 (Y1062) in RET. FRS2 selectively recruited RET to focal complexes and led to activation of SRC family kinases and focal adhesion kinase (FAK). Activation of SRC depended on its direct interaction with RET at a different intracellular tyrosine (Y981) and activation of molecular signaling from these two separate sites in concert regulated migration. Our data suggest that an important function for FRS2 is to concentrate RET in membrane foci, leading to an engagement of specific signaling complexes localized in these membrane domains. J. Cell. Biochem. 104: 879–894, 2008. © 2008 Wiley‐Liss, Inc.
Sanguinarine‐induced apoptosis: Generation of ROS, down‐regulation of Bcl‐2, c‐FLIP, and synergy with TRAIL
Authors: Kim Shin , Lee Tae‐Jin , Leem Jaechan , Choi Kyeong Sook , Park Jong‐Wook , Kwon Taeg Kyu
Published: January 2008

Sanguinarine is a benzophenanthridine alkaloid derived from the root of Sanguinaria canadensis and other poppy‐fumaria species, possessing potent antibacterial, antifungal, and anti‐inflammatory activities. In this study, we investigated the underling mechanisms by which sanguinarine induce apoptosis in human breast cancer MDA‐231 cells. Treatment of MDA‐231 cells with sanguinarine induced remarkable apoptosis accompanying the generation of ROS. Consistently, sanguinarine‐induced apoptosis was mediated by the increased reproductive cell death. Pretreatment with NAC or GSH attenuated sanguinarine‐induced apoptosis, suggesting the involvement of ROS in this cell death. During sanguinarin‐induced apoptosis, protein levels of pro‐caspase‐3, Bcl‐2, cIAP2, XIAP, and c‐FLIPs were reduced. Sanguinarine‐mediated apoptosis was substantially blocked by ectopic expression of Bcl‐2 and cFLIPs. Additionally, we found that sub‐lethal doses of sanguinarine remarkably sensitized breast cancer cells to TRAIL‐mediated apoptosis, but the cell death induced by sanguinarine and TRAIL in combination was not blocked by overexpression of Bcl‐2 or Akt. Therefore, combinatory treatment of sanguinarine and TRAIL may overcome the resistance of breast cancer cells due to overexpression of Akt or Bcl‐2. J. Cell. Biochem. 104: 895–907, 2008. © 2008 Wiley‐Liss, Inc.
Reishi immuno‐modulation protein induces interleukin‐2 expression via protein kinase‐dependent signaling pathways within human T cells
Authors: Hsu Hsien‐Yeh , Hua Kuo‐Feng , Wu Wei‐Chi , Hsu Jason , Weng Shih‐Ting , Lin Tsai‐Leng , Liu Chun‐Yi , Hseu Ruey‐Shyang , Huang Ching‐Tsan
Published: January 2008

Ganoderma lucidum, a medicinal fungus is thought to possess and enhance a variety of human immune functions. An immuno‐modulatory protein, Ling Zhi‐8 (LZ‐8) isolated from G. lucidum exhibited potent mitogenic effects upon human peripheral blood lymphocytes (PBL). However, LZ‐8‐mediated signal transduction in the regulation of interleukin‐2 (IL‐2) gene expression within human T cells is largely unknown. Here we cloned the LZ‐8 gene of G. lucidum, and expressed the recombinant LZ‐8 protein (rLZ‐8) by means of a yeast Pichia pastoris protein expression system. We found that rLZ‐8 induces IL‐2 gene expression via the Src‐family protein tyrosine kinase (PTK), via reactive oxygen species (ROS), and differential protein kinase‐dependent pathways within human primary T cells and cultured Jurkat T cells. In essence, we have established the nature of the rLZ‐8‐mediated signal‐transduction pathways, such as PTK/protein kinase C (PKC)/ROS, PTK/PLC/PKCalpha/ERK1/2, and PTK/PLC/PKCalpha/p38 pathways in the regulation of IL‐2 gene expression within human T cells. Our current results of analyzing rLZ‐8‐mediated signal transduction in T cells might provide a potential application for rLZ‐8 as a pharmacological immune‐modulating agent. J. Cell. Physiol. 215: 15–26, 2008. © 2008 Wiley‐Liss, Inc.
Wheat germ agglutinin stains dispersed post‐golgi vesicles after treatment with the cytokinesis inhibitor psychosine
Authors: Kanazawa Takayuki , Takematsu Hiromu , Yamamoto Akitsugu , Yamamoto Harumi , Kozutsumi Yasunori
Published: January 2008

The galactosylsphingosine psychosine (Psy) is one of the sphingolipids and induce the formation of multinuclear cells in several cell lines by inhibiting cytokinesis. In the present report, we show that intracellular organelles, including wheat germ agglutinin (WGA)‐positive vesicles and early endosomes, are selectively dispersed by Psy. WGA is a conventional Golgi marker and WGA‐positive vesicles appeared to co‐localize with the Golgi apparatus in untreated cells. Psy treatment induced the dispersal of WGA‐positive vesicles without affecting the structure of the Golgi apparatus, resulting in discrimination of WGA‐positive vesicles from the Golgi apparatus. In sharp contrast to this effect of Psy, WGA‐positive vesicles were not affected by brefeldin A treatment, which induced the disappearance of the Golgi apparatus. Immunostaining with anti‐TGN46 antibodies revealed that a large portion of the WGA‐positive vesicles were derived from the trans‐Golgi network. Notably, the dispersed WGA‐positive vesicles did not stain with anti‐syntaxin 6, another marker of the trans‐Golgi network. During cytokinesis, WGA‐positive vesicles in the cytoplasm decreased, and WGA staining accumulated at the cleavage furrow, which was apparently inhibited by the presence of Psy. These data suggest that the transport of WGA‐positive vesicles to the cleavage furrow is associated with the progression of cytokinesis. J. Cell. Physiol. 215: 517–525, 2008. © 2008 Wiley‐Liss, Inc.
Mechanism of electron transfer reaction of ternary nitrilotriacetatocobalt(II) complexes involving succinate and malonate as secondary ligands
Authors: Ewais Hassan A.
Published: January 2008

The mechanism of oxidation of ternary complexes, [CoII(nta)(S)(H2O)2]3− and [CoII(nta)(M)(H2O)]3− (nta = nitrilotriacetate acid, S = succinate dianion, and M = malonate dianion), by periodate in aqueous medium has been studied spectrophotometrically over the (20.0–40.0) ± 0.1°C range. The reaction is first order with respect to both [IO4−] and the complex, and the rate decreases over the [H+] range (2.69–56.20) × 10−6 mol dm−3 in both cases. The experimental rate law is consistent with a mechanism in which both the hydroxy complexes [CoII(nta)(S)(H2O)(OH)]4− and [CoII(nta)(M)(OH)]4− are significantly more reactive than their conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of the [CoII(nta)(S)(H2O)2]3−, k1 (3.60 × 10−3 s−1), is greater than the value of k6 (1.54 × 10−3 s−1) for the oxidation of [CoII(nta)(M)(H2O)]3− at 30.0 ± 0.1°C and I = 0.20 mol dm−3. The thermodynamic activation parameters have been calculated. It is assumed that electron transfer takes place via an inner‐sphere mechanism. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 103–113, 2008
Ru(III)‐catalyzed oxidation of cysteine hydrochloride by methylene blue in acidic medium; synergetic effect of Cu(II): A kinetic study
Authors: Chaturvedi R. , Mishra K. K.
Published: January 2008

Cysteine hydrochloride and methylene blue (MB) interact in a molar ratio of 2:1 in acidic medium forming cystine and dihydromethylene blue, and the reaction is catalyzed by Ru(III). At low concentrations (ca. 2.0 × 10−8 M), Cu(II) does not catalyze the reaction significantly but at this concentration level the catalytic activity of Ru(III) is found to be augmented by the addition of Cu(II) and the kinetics of Ru(III)‐catalyzed reaction has been studied in the absence and in the presence of externally added Cu(II). The reaction follows a half‐order kinetics in MB that increases to ¾ on increasing [MB] beyond 1.5 × 10−5 M in the Ru‐catalyzed reaction. In the Ru–Cu catalyzed reaction; the order in MB is ¾ even at lower concentrations of MB. The order in cysteine is unity. The rate decreases on increasing [MB] in both cases but attains a limiting value at higher concentrations of MB (ca. >2.0 × 10−5 M) in the presence of Ru(III) alone. The rate increases on increasing [H+] and in Ru‐catalyzed reaction, an optimum is noticed. The rate increases linearly with increasing [Ru(III)], but equilibration of the catalyst with other ingredients of the reaction system decreases the rate. The FTIR spectra of the reaction system exhibit time‐dependent changes in the stretching as well as bending modes of –SH group. The synergetic effect of Cu(II) has been attributed to its ligation with cysteine and its subsequent interaction with Ru(II) produced in situ in the system. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 145–150, 2008
Peculiar kinetics of the complex formation in the iron(III)–sulfate system
Authors: Kormányos Balázs , Peintler Gábor , Nagy Andrea , Nagypál István
Published: January 2008

The results of comprehensive equilibrium and kinetic studies of the iron(III)–sulfate system in aqueous solutions at I = 1.0 M (NaClO4), in the concentration ranges of T = 0.15–0.3 mM, and at pH 0.7–2.5 are presented. The iron(III)–containing species detected are FeOH2+ (=FeH−1), (FeOH) (=Fe2H−2), FeSO, and Fe(SO4) with formation constants of log β = −2.84, log β = −2.88, log β = 2.32, and log β = 3.83. The formation rate constants of the stepwise formation of the sulfate complexes are k1a = 4.4 × 103 M−1 s−1 for the \documentclass{article}\pagestyle{empty}\begin{document}${\rm Fe}^{3+} + {\rm SO}_4^{2-}\,\stackrel{k_{1a}}{\rightleftharpoons}\, {\rm FeSO}_4^+$\end{document} step and k2 = 1.1 × 103 M−1 s−1 for the \documentclass{article}\pagestyle{empty}\begin{document}${\rm FeSO}_4^+ + {\rm SO}_4^{2-} \stackrel{k_2}{\rightleftharpoons}\, {\rm Fe}({\rm SO}_4)_2^-$\end{document} step. The mono‐sulfate complex is also formed in the \documentclass{article}\pagestyle{empty}\begin{document}${\rm Fe}({\rm OH})^{2+} + {\rm SO}_4^{2-} \stackrel{k_{1b}}{\longrightarrow} {\rm FeSO}_4^+$\end{document} reaction with the k1b = 2.7 × 105 M−1 s−1 rate constant. The most surprising result is, however, that the 2 FeSO⇌ Fe3+ + Fe(SO4) equilibrium is established well before the system as a whole reaches its equilibrium state, and the main path of the formation of Fe(SO4) is the above fast (on the stopped flow scale) equilibrium process. The use and advantages of our recently elaborated programs for the evaluation of equilibrium and kinetic experiments are briefly outlined. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 114–124, 2008
Analysis and computational study of several integer programming formulations for minimum‐energy multicasting in wireless ad hoc networks
Authors: Bauer Joanna , Haugland Dag , Yuan Di
Published: January 2008

A multicast session in a wireless ad hoc network concerns routing messages from a source to a set of destination devices. Transmitting messages consumes energy at the source and intermediate devices of the session. Since a battery is the only energy source in many applications of wireless ad hoc networks, energy efficiency is an important performance measure of multicasting. In this paper, we present and analyze integer programming models for the problem of minimizing the total energy required by multicasting. We start from a straightforward multicommodity flow model, which is strengthened by a more efficient representation of transmission power. Further strengthening is accomplished by lifting the capacity constraints of the model. We then present cut‐based models for the problem, and prove, from a bounding standpoint, the equivalence in strength between these models and their flow‐based counterparts. By expanding the underlying graph, we show that the problem can be transformed into finding a minimum Steiner arborescence. The expanded graph arises also in the separation procedure for solving one of the cut‐based models. In addition to a theoretical analysis of the relation between various models, we perform extensive computational experiments to study the numerical strengths of these models and their efficiency in solving the problem. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Exact algorithms for the master ring problem
Authors: Shachnai Hadas , Zhang Lisa , Matsui Tomomi
Published: January 2008

We consider the master ring problem (MRP) which often arises in optical network design. Given a network which consists of a collection of interconnected rings R1,…,RK, with n1,…,nK distinct nodes, respectively, we need to find an ordering of the nodes in the network that respects the ordering of every individual ring, if one exists. We show that MRP is NP‐complete, and therefore, it is unlikely to be solvable by a polynomial time algorithm. Our main result is an algorithm which solves MRP in $ Q \cdot \Pi_{k=1}^{K} (n_{k}/\sqrt{2}) $ steps, for some polynomial Q, as the nk values become large. For the ring clearance problem, a special case of practical interest, our algorithm achieves this running time for rings of any size nk ≥ 2. This yields the first nontrivial improvement, by factor of $ (2\sqrt{2})^{K} \approx (2.82)^{K} $, over the running time of the naive algorithm, which exhaustively enumerates all $ \Pi_{k=1}^{K} (2n_{k}) $ possible solutions. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
On the diameter of the generalized undirected de Bruijn graphsUGB(n,m),n2<m≤n3
Authors: Kuo Jyhmin , Fu Hung‐Lin
Published: January 2008

The generalized de Bruijn digraphGB(n,m) is the digraph (V,A) whereV= {0, 1,…,m− 1} and (i,j) ∈Aif and only ifj≡in+α(modm) for someα∈ {0, 1, 2,…,n− 1}. By replacing each arc ofGB(n,m) with an undirected edge and eliminating loops and multi‐edges, we obtain the generalized undirected de Bruijn graphUGB(n,m). In this article, we prove that when 2n2≤m≤n3the diameter ofUGB(n,m) is equal to 3. We also show that for pairs (n,m) wheren2<m< 2n2the diameter ofUGB(n,m) can be 2 or 3. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Reliability of interconnection networks modeled by Cartesian product digraphs
Authors: Yang Chao , Xu Jun‐Ming
Published: January 2008

We determine that the connectivity and the edge‐connectivity of the Cartesian product G1 × G2 of two strongly connected and finite digraphs G1 and G2 are equal to min{n1κ2,n2κ1,δ + δ, δ + δ} and min{n1λ2,n2λ1, δ + δ, δ + δ}, respectively, where ni, κi, λi, δ, δ are the order, the connectivity, the edge‐connectivity, the minimum out‐degree and the minimum in‐degree of Gi, respectively, for i = 1, 2. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Valid cycles: A source of infeasibility in open shortest path first routing
Authors: Broström Peter , Holmberg Kaj
Published: January 2008

Many telecommunication networks use the open shortest path first (OSPF) protocol for the routing of traffic. In such networks, each router sends the traffic on the shortest paths to the destination, with respect to the link weights assigned. An interesting question is whether or not a set of desired routing patterns can be obtained in an OSPF network by assigning appropriate weights. If not, we wish to find the source of the infeasibility. We study these issues by formulating a mathematical model and investigating its feasibility. A certain structure, called valid cycle, is found to be present in most infeasible instances. This yields new necessary conditions, stronger than those previously known, for the existence of weights yielding a set of given desired shortest path graphs. A valid cycle indicates which parts of the routing patterns are in conflict and can be used for changing the routing patterns to make the problem feasible. A polynomial algorithm for finding valid cycles is presented, the method is illustrated by a numerical example, and computational tests are reported. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Considerations in the identification, assessment, and intervention process for deaf and hard of hearing students with reading difficulties
Authors: Gilbertson Donna , Ferre Scot
Published: January 2008

Problematic assessment and intervention issues present substantial challenges when making educational decisions for deaf or hard of hearing (D/HH) students who are experiencing reading difficulties. These students present a diverse set of language acquisition skills, hearing ability, and orientation to early school learning activities that are different from the hearing student population. Given the importance of selecting assessment approaches that lead to effective interventions for D/HH students, three assessment procedures for identification of at‐risk children and learning disabilities within the D/HH population are examined. Assessments reviewed are teacher referral, norm‐referenced testing, and student response to intervention. Challenges to each process and the need for additional assessment and empirically validated treatment options are discussed. Finally, a case example is presented to illustrate a framework that may help school psychologists promote early identification of learning problems and outline interventions that meets a D/HH child's unique needs by focusing on reading outcomes in the curriculum. © 2008 Wiley Periodicals, Inc.
Attachment relationships and adolescents' life satisfaction: Some relationships matter more to girls than boys
Authors: Ma Claudia Q. , Huebner E. Scott
Published: January 2008

This study examined the extent to which the quality of parent and peer attachments related to early adolescents' life satisfaction (LS), whether peer attachment served as a mediator between parent attachment and LS, and potential gender differences. A total of 587 middle school students in grades 6 through 8 participated. Although both parent and peer attachment positively related to LS, parent attachment was the stronger unique predictor. There was no significant difference between males and females in levels of parent attachment; however, females reported higher levels of attachment to peers. This study also found that early adolescents were more attached to their mothers than their fathers. Finally, peer attachment partially mediated the relationship between parent attachment and LS, but only for females. Implications for gender‐specific intervention programs are discussed. © 2008 Wiley Periodicals, Inc.
Theoretical studies on aromaticity of selected hydroxypyrones and their cations and anions. Part 2. Electron delocalisation in the OCCO group
Authors: Zborowski Krzysztof , Proniewicz Leonard M.
Published: January 2008

Electron delocalisation in the OCCO part of hydroxypyrones with two exocyclic oxygens linked by two carbon atoms was studied using well‐known aromaticity indices like: HOMA, EN, GEO, NICS(0) and NICS(1). This part of hydroxypyrones is very important due to the fact that the two exocyclic oxygens of deprotonated hydroxypyrone units are responsible for metal ion binding. Values of the aromaticity indices were obtained for geometries calculated by several theoretical methods (HF, SVWN, B3LYP and B1LYP) with 6‐311 ++ G(d,p) basis set. Electron delocalisation in the corresponding cations and anions was also considered. The data obtained in this work revealed that the relative delocalisation order in the OCCO group is the same as the aromaticity order determined earlier for the heterocyclic rings of hydroxypyrones (anions < neutral molecule < cation). The problem of quasiaromaticity in neutral hydroxypyrones and their cations is also considered and discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Immunoproteomics: From biomarker discovery to diagnostic applications
Authors: Tjalsma Harold , Schaeps Renée M. J. , Swinkels Dorine W.
Published: January 2008

Circulating antibodies reflect a molecular imprint of antigens that are related to autoimmune diseases, cancer or infection. Importantly, serum antibodies are useful clinical markers as they carry diagnostic information from all around the human body. Moreover, the amplification cascade governed by the humoral immune system causes a surplus of circulating antibodies after appearance of the corresponding (low abundance) antigen. In combination with the fact that antibodies are highly stable compared to many other serum proteins, they seem ideal to be implemented in clinical diagnostic assays for the detection of antigen‐associated diseases. This review summarises advances in immunoproteomics with respect to technologies for biomarker discovery, with special emphasis on recently developed gel‐free MS‐based approaches, and looks forward to potential immunoproteomic applications in diagnostic medicine.
RNASEL and RNASEL‐inhibitor variation and prostate cancer risk in Afro‐Caribbeans
Authors: Shea Patrick R. , Ishwad Chandramohan S. , Bunker Clareann H. , Patrick Alan L. , Kuller Lewis H. , Ferrell Robert E.
Published: January 2008

BACKGROUND

Afro‐Caribbeans from Tobago are at high risk of developing prostate cancer. This elevated risk of prostate cancer is shared by populations of African ancestry living in diverse environments in the Western hemisphere. Variation in the ribonuclease L (RNASEL) gene has recently been reported to be associated with an increased risk of prostate cancer. However, whether RNASEL variation contributes to the increased risk of prostate cancer observed in populations of African ancestry remains unclear.

METHODS

We resequenced the positional candidate gene RNASEL in 48 prostate cancer cases and genotyped the previously reported R462Q and D541E polymorphisms in 230 prostate cancer cases and 458 controls. We also examined the inhibitor of RNASEL (ABCE1) for variation associated with prostate cancer risk.

RESULTS

We found no evidence of association between R462Q and D541E polymorphisms and prostate cancer risk in our case/control analysis. A novel variant (K294E) was identified in a single heterozygous individual with prostate cancer. We also observed a 20 bp insertion/deletion polymorphism 1,109 bp upstream of the initiation codon, but this variant was not associated with prostate cancer. We identified 16 single nucleotide polymorphisms in the ABCE1 gene, only 3 of which had a minor allele frequency >5%. A common A/G transition −1,071 bp from the transcriptional start site was genotyped and showed no evidence of association with prostate cancer.

CONCLUSIONS

Our results suggest that common variation in the putative prostate cancer susceptibility gene, RNASEL, or its inhibitor does not contribute significantly to prostate cancer risk in this Afro‐Caribbean population. Prostate 68: 354–359, 2008. © 2008 Wiley‐Liss, Inc.
Obesity and screening PSA levels among men undergoing an annual physical exam
Authors: Rundle Andrew , Neugut Alfred I.
Published: January 2008

BACKGROUND

Prior reports suggest that obesity is inversely associated with screening prostate‐specific antigen (PSA) levels and may reduce screening sensitivity.

METHODS

We evaluated data on 10,623 men screened for prostate cancer during an annual physical examination program administered by EHE International, Inc., between 1/1/2004 and 6/30/2006. Of these, 3,623 men returned for additional physical exams during this period. We used multivariate linear regression analyses to determine whether higher BMI was inversely associated with PSA, and whether BMI, or change in BMI, was associated with change in PSA levels over time. We also developed a theoretical model for the effect of obesity on PSA levels in which increased plasma volume in the obese dilutes PSA levels.

RESULTS

After control for age and race/ethnicity, higher BMI was associated with lower PSA levels; men with a BMI ≥40 had a geometric mean PSA level 0.14 ng/ml lower than men with a BMI <25 (P < 0.001). Prospectively, BMI at initial screening and change in BMI over 2 years were not associated with change in PSA or PSA velocity. Our theoretical model accurately predicted observed PSA levels and suggests that a screening PSA of 4.0 ng/ml in normal weight and overweight men corresponds to 3.5 ng/ml in obese men and 3.1 ng/ml in morbidly obese men.

CONCLUSION

Across the study population, increased BMI was significantly inversely associated with lower PSA. Based on a theoretical model in which increased plasma volume in the obese dilutes PSA levels we propose new cut‐points for a positive screening test. Prostate 68: 373–380, 2008. © 2008 Wiley‐Liss, Inc.
Gamma radiation sensitivity of the eggs, larvae and pupae of Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)
Authors: Ayvaz Abdurrahman , Albayrak Sevil , Karaborklu Salih
Published: January 2008

BACKGROUND: This study focused on determining the minimal effective gamma radiation dose that prevents commodity damage caused by the Indian meal moth Plodia interpunctella (Hübner). The study was also designed to assess the effect of releasing either partially sterilized males alone or both partially sterilized males and females on the reproductive potential of P. interpunctella populations.

RESULTS: The dose of radiation required to prevent larval emergence from irradiated eggs was 350 Gy, and the same dose was also required to prevent adult emergence from mature larvae. A dose of 300 Gy was not able to prevent adult emergence from irradiated pupae. The dose at which 100% sterility was achieved in treated females mated to treated males was 300 Gy for the parental generation of irradiated pupae. Fertility of the parental males from irradiated pupae was 48.17% at 300 Gy in treated males crossed with untreated females, but male progeny of irradiated male parents had a residual fertility of 11.06% at the same dose.

CONCLUSION: F1 males from irradiated pupae were more sterile than parental males. To prevent larval emergence from irradiated eggs, a dose of 350 Gy is required. The same dose is required to prevent the larvae from reaching the adult stage. Copyright © 2008 Society of Chemical Industry
Distribution of a juvenogen and its metabolites in a laboratory system during juvenogen‐induced caste differentiation in a termite, Reticulitermes santonensis (Isoptera: Rhinotermitidae)
Authors: Tykva Richard , Černý Bohuslav , Wimmer Zdeněk , Hanus Robert
Published: January 2008

BACKGROUND: Juvenoids and juvenogens have been for many years considered promising candidates for control of pest insect species including termites. Their use as termite pest management agents requires the generation of knowledge concerning their degradation and distribution in time and space. Groups of 40 Reticulitermes santonensis de Feytaud workers were provided with wood impregnated with a juvenogen, ethyl cis‐N‐{2‐[4‐(2‐butyryloxycyclohexylmethyl)phenoxy]ethyl}carbamate, labelled with tritium in the benzene ring (305 GBq mmol−1). After 14 days the radioactivity was determined in all elements of the experimental system.

RESULTS: The majority of the input activity was detected in the wood, only about 1% in the bodies of surviving termites and 1% in the substrate. A considerable part of the input activity was probably lost as gaseous termite metabolites. The activity in workers was significantly higher than in presoldiers, which had differentiated under the influence of the labelled juvenogen. A stable value of radioactivity was detected on the body surfaces.

CONCLUSIONS: The results suggest good stability of the compound in the wooden carrier and low contamination of the environment with non‐gaseous residuals, together with the desired biological impact on termite caste differentiation. Copyright © 2008 Society of Chemical Industry
Recently identified a novel neuropeptide manserin colocalize with the TUNEL‐positive cells in the top villi of the rat duodenum
Authors: Yajima Aika , Narita Naoko , Narita Masaaki
Published: January 2008

We recently isolated a novel 40 amino acid neuropeptide designated manserin from the rat brain. Manserin is derived from secretogranin II, a member of granin acidic secretory protein family by proteolytic processing, as previously reported secretoneurin and EM66. Manserin peptide are localized in the endocrine cells of the pituitary. In this study, we further investigated the manserin localization in the digestive system by immunohistochemical analysis using antimanserin antibody. In the duodenum, manserin immunostaining was exclusively observed in the nuclei of top villi instead of cytosol as observed in neurons in our previous study. Interestingly, manserin‐positive cells in the duodenum are colocalized with terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) positive cells, the cells whose DNA was damaged. Since the top villi of duodenum epithelial cells are known to undergo spontaneous apoptosis during epithelial cell turn over, and since other peptides such as secretoneurin and EM66 derived from SgII have been reported to be cancer‐related, these results indicated that manserin peptide may have a role in apoptosis and/or cancer pathogenesis in the digestive organ. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
A field and laboratory method for monitoring the concentration and isotopic composition of soil CO2
Authors: Breecker Dan , Sharp Zachary D.
Published: January 2008

The stable isotope composition of nmol size gas samples can be determined accurately and precisely using continuous flow isotope ratio mass spectrometry (IRMS). We have developed a technique that exploits this capability in order to measure δ13C and δ18O values and, simultaneously, the concentration of CO2 in sub‐mL volume soil air samples. A sampling strategy designed for monitoring CO2 profiles at particular locations of interest is also described. This combined field and laboratory technique provides several advantages over those previously reported: (1) the small sample size required allows soil air to be sampled at a high spatial resolution, (2) the field setup minimizes sampling times and does not require powered equipment, (3) the analytical method avoids the introduction of air (including O2) into the mass spectrometer thereby extending filament life, and (4) pCO2, δ13C and δ18O are determined simultaneously. The reproducibility of measurements of CO2 in synthetic tank air using this technique is: ±0.08‰ (δ13C), ±0.10‰ (δ18O), and ±0.7% (pCO2) at 5550 ppm. The reproducibility for CO2 in soil air is estimated as: ±0.06‰ (δ13C), ±0.06‰ (δ18O), and ±1.6% (pCO2). Monitoring soil CO2 using this technique is applicable to studies concerning soil respiration and ecosystem gas exchange, the effect of elevated atmospheric CO2 (e.g. free air carbon dioxide enrichment) on soil processes, soil water budgets including partitioning evaporation from transpiration, pedogenesis and weathering, diffuse solid‐earth degassing, and the calibration of speleothem and pedogenic carbonate δ13C values as paleoenvironmental proxies. Copyright © 2008 John Wiley & Sons, Ltd.
New insights on the Cd UPD on Au(111)
Authors: del Barrio M. C. , García S. G. , Mayer C. E. , Salinas D. R.
Published: January 2008

The Cd underpotential deposition (UPD) process on Au(111) was analyzed by means of combined electrochemical measurements and in situ scanning tunneling microscopy (STM). In the underpotential range 300⩽ΔE (mV) ⩽400, 2D Cd islands are formed on the fcc regions of the Au(111)‐(√3 × 22) reconstructed surface without lifting the reconstruction. At lower underpotentials, the 2D Cd islands grow and, simultaneously, new 2D islands nucleate and coalesce with the previous ones forming a complete condensed Cd monolayer (ML). STM images and long time polarization experiments performed at ΔE = 70 mV demonstrate the formation of an AuCd surface alloy. At ΔE = 10 mV, the formation of the complete Cd ML is accompanied by a significant AuCd surface alloying and the kinetic results reveal two different solid‐state diffusion processes. The first one, with a diffusion coefficient D1 = 4 × 10−17 cm2 s−1, could be ascribed to the mutual diffusion of Au and Cd atoms through a highly distorted (vacancy‐rich) AuCd alloy layer. The second and faster diffusion process (D2 = 7 × 10−16 cm2 s−1) is associated with the appearance of an additional peak in the anodic stripping curves and could be attributed to the formation of another CdzAux alloy phase. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of deposition pressure on the properties of DLC coatings deposited by bipolar‐type PBII&D
Authors: Choi Junho , Nakao Setsuo , Ikeyama Masami , Kato Takahisa
Published: January 2008

In the present study, the effect of deposition pressure on the deposition rate and various properties of diamond‐like carbon (DLC) coatings were investigated. The DLC coatings were deposited on Si substrates using a bipolar‐type plasma‐based ion implantation and deposition plasma based ion implantation and deposition (PBIID) technique. The toluene was used as a source gas and the deposition pressure ranged from 0.03 to 2.0 Pa. The deposition rate of the DLC coatings increases about 12 times as the deposition pressure is changed from 0.03 to 2.0 Pa. Also, the surface roughness increases with increasing deposition pressure due to high deposition rate. The hardness and elastic modulus decrease when the deposition pressure exceed 0.7 Pa due to the remarkable growth of graphitic islands. The corrosion protection performance of the DLC coating deposited at 2.0 Pa is superior to that of the DLC coating deposited at 0.2 Pa for the same deposition time of 1 h. The high deposition pressure for the DLC coating is effective in improvement of corrosion protection properties. Copyright © 2008 John Wiley & Sons, Ltd.
Resampling‐based analyses of the effects of combinations of HIV genetic mutations on drug susceptibility
Authors: Schumi Jennifer , DeGruttola Victor
Published: January 2008

Viral genotype data aid in understanding the development of antiretroviral drug resistance and in identifying appropriate treatments. Using HIV‐1 protease sequences and measures of in vitro sensitivity to the drug amprenavir, we develop a novel statistical approach that can be used to investigate combinations of mutations that alter drug susceptibility. Our method is based on the use of order statistics whose null distributions are estimated through resampling and used for formal hypothesis testing. We present a step‐down testing method that preserves the overall family‐wise error rate in finite samples via an application of the monotonicity condition of Romano and Wolf. Simulations demonstrate that the power of this new approach is comparable to a traditional resampling method; however, this approach can also be used as a visual diagnostic that may be informative even when specified hypotheses are not rejected, for example, in suggesting candidate regression models. Analysis of the data from the Stanford HIV database shows that while M46I/L mutations are associated with drug resistance, addition of the L88D/S mutation leads to hypersusceptible virus. Further addition of T90M/L mutations results in highly resistant virus. Use of this order statistics method allows the investigation of how mutations act in the presence of others and may suggest mechanisms by which resistance occurs or is reversed through the accumulation of mutations. Copyright © 2008 John Wiley & Sons, Ltd.