bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vivo Tracking of Human Mesenchymal Stem Cells in Experimental Stroke
Authors: Kim Daehong , Chun Byoung-Gi , Kim Yeon-Kyung , Lee Yong Hyun , Park Cheong-Soo , Jeon Iksoo , Cheong Chaejoon , Hwang Tae-Sun , Chung Hyungmin , Gwag Byoung Joo , Hong Kwan Soo , Song Jihwan
Published: April 2008

To understand the fates of human mesenchymal stem cells (hMSCs) following transplantation into a rodent model of middle cerebral artery occlusion (MCAo), magnetic resonance imaging (MRI) techniques were employed. hMSCs were labeled with ferumoxides (Feridex®)-protamine sulfate complexes, which were visualized and examined by MRI up to 10 weeks following transplantation. Migration of the transplanted cells to the infarcted area was further confirmed by histological methods. We found that the hMSCs transplanted in MCAo models possess the capacity to migrate to the infarcted area extensively in both ipsilateral and contralateral injections, exhibiting a pathotropism. We also analyzed the detailed migration patterns of transplanted hMSCs. We speculate that the extensive migratory ability of hMSCs may represent a therapeutic potential for developing efficient cell transplantation strategies in stroke.
Automated, High-Throughput Assays for Evaluation of Human Pancreatic Islet Function
Authors: Cabrera Over , Jacques-Silva M. Caroline , Berman Dora M. , Fachado Alberto , Echeverri Felipe , Poo Ramon , Khan Aisha , Kenyon Norma S. , Ricordi Camillo , Berggren Per-Olof , Caicedo Alejandro
Published: April 2008

An important challenge in pancreatic islet transplantation in association with type 1 diabetes is to define automatic high-throughput assays for evaluation of human islet function. The physiological techniques presently used are amenable to small-scale experimental samples and produce descriptive results. The postgenomic era provides an opportunity to analyze biological processes on a larger scale, but the transition to high-throughput technologies is still a challenge. As a first step to implement high-throughput assays for the study of human islet function, we have developed two methodologies: multiple automated perifusion to determine islet hormone secretion and high-throughput kinetic imaging to examine islet cellular responses. Both technologies use fully automated devices that allow performing simultaneous experiments on multiple islet preparations. Our results illustrate that these technologies can be applied to study the functional status and explore the pharmacological profiles of islet cells. These methodologies will enable functional characterization of human islet preparations before transplantation and thereby provide the basis for the establishment of predictive tests for β-cell potency.
The Significance of Preserving the Energy Status and Microcirculation in Liver Grafts from Non-Heart-Beating Donor
Authors: Miyagi Shigehito , Iwane Takeru , Akamatsu Yorihiro , Nakamura Atsushi , Sato Akira , Satomi Susumu
Published: April 2008

To complete a successful liver transplantation (LTx) from non-heart-beating donors (NHBD), it is necessary to both improve the energy status in liver grafts and to reduce the exposure to free radicals. This study investigated the effects of short perfusion with oxygenated buffer on the grafts prior to cold preservation. In addition, the effects of the antioxidant, biliverdin, for reduction of free radicals was investigated. Male Wistar rats were used. Livers were retrieved, preserved in UW solution, and perfused for 60 min with oxygenated Krebs-Henseleit solution. Rats were allocated to six groups as follows (n = 5): i) control group—no warm ischemia (WI) and cold preservation, ii) HBD group—no WI with cold preservation for 6 h; iii) NHBD group—with 30 min of WI and cold preservation, iv) NM group—with WI including nafamostat mesilate infusion before cardiac arrest and cold preservation; v) PRE group—with WI, 30-min pre-cold preservation perfusion with oxygenated buffer after cardiac arrest, and cold preservation, vi) BV group—with the same treatment as the PRE group plus the addition of biliverdin to the pre-cold preservation perfusion. The portal flow volume, bile production, AST, and TNF-α in perfusate, energy charge (EC), and ATP level in the tissue, and histological findings were investigated. The portal flow volume in the NM, PRE, and BV groups were higher than in the NHBD group. The bile production in the PRE and BV groups were also higher than in the NHBD group. The EC and ATP level of the BV group after reperfusion were higher than those of the NHBD group. Pre-cold preservation perfusion and addition of biliverdin to perfusate improved viability of grafts from NHBD. The results indicate that the preservation of the energy status and microcirculation of the graft is important for successful LTx from NHBD.
Immortalized Hepatocytes Using Human Artificial Chromosome
Authors: Ito Masahiro , Ito Ryoutaro , Yoshihara Daisuke , Ikeno Masashi , Kamiya Megumi , Suzuki Nobutaka , Horiguchi Akihiko , Nagata Hideo , Yamamoto Toshiyuki , Kobayashi Naoya , Fox Ira J. , Okazaki Tsuneko , Miyakama Syuichi
Published: April 2008

The shortage of organ donors has impeded the development of human hepatocyte transplantation. Immortalized hepatocytes could provide an unlimited supply of transplantable cells. To determine whether immortalized hepatocytes could provide global metabolic support in end-stage liver disease, rat hepatocyte clones were developed by transduction with the gene encoding the Simian virus 40 T antigen (SVT) using the human artificial minichromosome (HAC). The SVLT sequence was excised by FRT recombination. Following HAC infusion, the transduced hepatocytes express SVT, blasticidine resistance (BS), and the PGK promoter TK gene. Forty-six cell clones were obtained and at least partially characterized, as previously described, for albumin, α-1-antitrypsin, glucose-6-phosphatase (G6Pase), dipeptidylpeptidase 4 (Dpp4), γ-glutamyltransferase 1 (Ggt), SVT, and β-actin expression using RT-PCR. Clones were also assessed for albumin secretion into the culture medium using ELISA. All of the cell line secreted approximately 10 mg/dl of albumin, which is equivalent to the amount secreted by primary hepatocytes. In further experiments, this cell line will be used for transplantable cells or artificial organ using HAC. These results represent an important step toward the development of immortalized hepatocytes.
ET-Kyoto Solution plus Dibutyryl Cyclic Adenosine Monophosphate is Superior to University of Wisconsin Solution in Rat Liver Preservation
Authors: Zhao Xiangdong , Koshiba Takaaki , Nakamura Takayuki , Tsuruyama Tatsuaki , Li Ying , Bando Toru , Wada Hiromi , Tanaka Koichi
Published: April 2008

ET-Kyoto solution (ET-K) is an extracellular-type organ preservation solution containing the cytoprotective disaccharide, trehalose. A previous study reported the supplement of dibutyryl cyclic adenosine monophosphate (db-cAMP) in conventional ET-K to attenuate lung ischemia-reperfusion injury. In this study, the efficacy of this modified ET-K for liver preservation was investigated by comparison with University of Wisconsin solution (UW). ET-K was supplemented with db-cAMP (2 mmol/L). Lewis rats were randomly assigned to two groups, and liver grafts were flushed and stored at 4°C for 24 h with ET-K or UW before syngeneic liver transplantation. The graft function and histological changes at 4 h posttransplant as well as 7-day survival were evaluated. Recipient rat survival rate was significantly higher in the ET-K group than in the UW group. Preservation in ET-K resulted in a significant reduction in serum parenchymal transaminase level and promotion of bile production in comparison with UW. The serum hyaluronic acid level, an indicator of sinusoidal endothelial cell injury, was significantly lower after ET-K preservation than that in UW. Histologically, at 4 h after transplantation, the liver grafts preserved in UW solution demonstrated a greater degree of injury than those in ET-K, which appeared to be apoptosis, rather than necrosis. The continuity of the sinusoidal lining was better preserved in ET-K than in UW. In conclusion, ET-K supplemented with db-cAMP is superior to UW in rat liver preservation. This modified ET-K might therefore be a novel candidate for the procurement and preservation of multiple organs.
Immunological Tolerance-Related Genes in a Spontaneous Tolerant Model of Rat Liver Transplantation Explored by Suppression Subtractive Hybridization
Authors: Zhang Huiqi , Ohmi Kazuhiro , Hirasawa Akira , Enosawa Shin , Hara Yoshiaki , Tamura Akihiko , Tsujimoto Gozoh
Published: April 2008

Natural immunological tolerance can be induced in certain types of allogeneic liver transplantation in rats. To screen for genes associated with the induction of tolerance, suppression subtractive hybridization was performed in the rat liver transplantation model between a DA donor and PVG recipient combination where spontaneous immunological tolerance is known to occur without any immunosuppressive treatment. As a result, 112 genes were cloned from a DA liver graft that survived for 20 days in the fully allogeneic PVG recipient. After confirmation of the expression intensity using an in-house manufactured DNA array with cDNAs from the DA graft, 36 genes were classified in the highly expressed group and 26 moderately expressed group. In the first group, there were 8 immunoglobulin-related genes and 6 MHC class II-related genes, suggesting the existence of an underlying rejection response. Among those genes, an antiapoptotic gene in the p38 MAP kinase pathway, heme oxygenase gene (HO-1), and a ras cascade gene, IQ motif containing GTPase activating protein 1 (Iqgap1), retained biological significance. The results suggested that the molecular response to a liver graft tends to be antiapoptotic and to terminate the rejection response. Unfortunately, there was no gene identified that qualified as a putative immunosuppressive protein, liver suppressor factor-1 (LSF-1). The panel of genes identified in the present work will be a useful panel of candidate genes to investigate the induction of spontaneous tolerance.
Laparoscopy-Assisted Creation of a Liver Failure Model in Pigs
Authors: Yuasa Takeshi , Yamamoto Tsuyoshi , Rivas-Carrillo Jorge D. , Chen Yong , Navarro-Alvarez Nalú , Soto-Guiterrez Alejandro , Noguchi Hirofumi , Matsumoto Shinichi , Tanaka Noriaki , Kobayashi Naoya
Published: April 2008

We created a hepatic failure pig model that was suitable for the assessment of cell therapies, such as hepatocyte transplantation and bioartificial livers, using a laparoscopic surgical technique. In our model, all of three hepatic arteries were resected, 5, 7.5, or 10 ml of carbon tetrachloride (CCL4) was injected into the liver through the portal vein, and subsequently the portal vein was mechanically occluded for 30 min. After the portal occlusion was released, a liver biopsy was performed, and then the surgery was completed. Blood samples were regularly taken during the surgery in order to perform biochemical examinations. All of five pigs in which 5 ml of CCL4was infused recovered spontaneously and survived; in contrast, all of five pigs that received 10 ml CCL4died within 1.5 h after surgery. The pigs in which 7.5 ml CCL4was administered developed liver failure and survived for 6.4 h on average (±1.4 SD). Induction of liver failure with the use of 7.5 ml CCL4and 30-min hepatic ischemia fulfilled five of the six criteria that were proposed by Terblanche and Hickman: reversibility, reproducibility, death from liver failure, a therapeutic window, and a large-animal model. We believe that our model is the first report on creation of a reliable model for liver failure in pigs to assess the efficacy of liver-targeted cell therapies.
Cancer Stem Cell Research: Current Situation and Problems
Authors: Kobayashi Naoya , Navarro-Alvarez Nalú , Soto-Gutierrez Alejandro , Kawamoto Hironobu , Kondo Yoshitaka , Yamatsuji Tomoki , Shirakawa Yasuhiro , Naomoto Yoshio , Tanaka Noriaki
Published: April 2008

The concept of a “cancer stem cell system” that continues to supply cancer component cells has been proposed. It is time to apply stem cell studies, which is a field of expertise in regenerative medicine, to cancer treatment. Cancer treatments that effectively attack cancer stem cells acting as a manufacturing plant for producing differentiated cancer progenies will be designed by revealing the cancer stem cell system. Therefore, in the near future we hope that revolution will occur in cancer therapy to eradicate cancer and prevent the recurrence thereof. In this review we discuss the current situation and problems of cancer stem cell research.
Cryopreservation of Human Pancreatic Islets from Non-Heart-Beating Donors Using Hydroxyethyl Starch and Dimethyl Sulfoxide as Cryoprotectants
Authors: Kenmochi Takashi , Asano Takehide , Maruyama Michihiro , Saigo Kenichi , Akutsu Naotake , Iwashita Chikara , Ohtsuki Kazunori , Suzuki Akiko , Miyazaki Mariko
Published: April 2008

Although widely used, DMSO is toxic for pancreatic islets. We combined hydroxyethyl starch (HES) with DMSO to simplify the procedure of freezing and thawing, and to decrease the toxicity of DMSO. A preclinical study was performed using islets from beagle dogs. After storage for 4 weeks, the islets were thawed and examined. The islet structure was well maintained after thawing. Although the number of the islets decreased to 71.2 ± 20.1%, the function of the islets was evaluated by static incubation after thawing and showed a 1.80 ± 0.78 stimulation index. We have introduced this technique for the cryopreservation of human islets from non-heart-beating donors. Twelve cases of human islet cryopreservation were performed. The sample tube of each human cryopreservation was thawed to evaluate the morphology, contamination, and endocrine function. Although fragmentation was observed in five samples (41.6%), the other seven (58.4%) showed a normal structure when evaluated by microscopic and electron microscopic study. The stimulation index (SI) of static incubation deteriorated from 3.37 ± 3.02 to 1.34 ± 0.28 after thawing. We divided the thawed islets into two groups: group 1 (n = 8), SI >1.2; group 2 (n = 4), SI <1.2. The group 1 islets showed a higher rate of normal structure (87%) than did group 2 (25%). Moreover, the SI before cryopreservation was 4.01 ± 3.57 in group 1, which was higher than the SI of 2.11 ± 0.72 in group 2. Based on the good results from the preclinical study using a large-animal model, this method was introduced for clinical application. Even from the pancreata of non-heart-beating donors, a successful islet cryopreservation was achieved. However, the isolated islets with poor function should not be cryopreserved for transplantation.
Promotion of Hydroxyapatite-Associated, Stem Cell-Based Bone Regeneration by CCN2
Authors: Ono Mitsuaki , Kubota Satoshi , Fujisawa Takuo , Sonoyama Wataru , Kawaki Harumi , Akiyama Kentaro , Shimono Kengo , Oshima Masamitsu , Nishida Takashi , Yoshida Yasuhiro , Suzuki Kazuomi , Takigawa Masaharu , Kuboki Takuo
Published: April 2008

Multiple roles have been already recognized for CCN2 in cartilage development and regeneration. However, the effects of CCN2 on bone regeneration remain to be elucidated. In this study, the utility of CCN2 on bone regeneration was examined in vitro and in vivo in combination with hydroxyapatite (HAp) as a scaffold. Human bone marrow stromal cells (hBMSCs) were isolated from human iliac bone marrow aspirates of healthy donors and expanded, and the effects of CCN2 on their proliferation and migration were examined in vitro. The proliferation of hBMSCs on a plastic or HAp plate was significantly enhanced by CCN2. Moreover, the migration of hBMSCs also dramatically increased by CCN2. Interestingly, a C-terminal signal modular fragment of CCN2 (CT-module) also enhanced the cell proliferation and migration as efficiently as the full-length CCN2. Next, in order to estimate the effect of CCN2 on the migration and survival of hBMSCs and bone formation inside the HAp scaffold in vivo, two experiments were performed. First, the porous HAp carrier was cultured with hBMSCs for a week, and the cell–scaffold hybrid was transplanted with or without CCN2 subcutaneously into immunocompromised mice. CCN2 accelerated the hBMSC-like cell migration and survival inside the porous HAp within 4 weeks after transplantation. Second, the porous HAp carrier with or without CCN2 was directly implanted into bone defects within a rabbit mandible, and bone regeneration inside was evaluated. As a result, CCN2 efficiently induced the cell invasion and bone formation inside the porous HAp scaffold. These findings suggest that CCN2 and its CT-module fragment could be useful for regeneration and reconstruction of large-scale bone defects.
Robust stabilization of a class of non‐minimum‐phase nonlinear systems in a generalized output feedback canonical form
Authors: Fu Jun , Jin Ying , Zhao Jun , Dimirovski G. M.
Published: April 2008

In this paper, a globally robust stabilizer for a class of uncertain non‐minimum‐phase nonlinear systems in generalized output feedback canonical form is designed. The system contains unknown parameters multiplied by output‐dependent nonlinearities and output‐dependent nonlinearities enter such a system both additively and multiplicatively. The proposed method relies on a recently developed novel parameter estimator and state observer design methodology together with a combination of backstepping and small‐gain approach. Our design has three distinct features. First, the parameter estimator and state observer do not necessarily follow the classical certainty‐equivalent principle any more. Second, the design treats unknown parameters and unmeasured states in a unified way. Third, the technique by combining standard backstepping and small‐gain theorem ensures robustness with respect to dynamic uncertainties. Finally, two numerical examples are given to show that the proposed method is effective, and that it can be applied to more general systems that do not satisfy the cascading upper diagonal dominance conditions developed in recent papers, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
No pathogenic rearrangement within the DISC 1 gene in psychosis
Authors: Legallic Solenn , Bou Jacqueline , Haouzir Sadeq , Allio Gabrielle , Demily Caroline , Petit Michel , Frebourg Thierry , Thibaut Florence , Campion Dominique
Published: April 2008

A translocation disrupting the DISC 1 gene segregates with schizophrenia and related psychiatric disorders in a large Scottish family. Mutation screening of this gene by routine PCR‐based methods has remained largely negative. We sought to detect rearrangements affecting DISC 1 in 347 individuals meeting the DSM3R criteria for schizophrenia or schizoaffective disorder, 70 subjects with bipolar disorder and 377 psychiatrically healthy controls, but failed to detect any pathological rearrangement. © 2008 Wiley‐Liss, Inc.
Preparation of sulfonated polypropylene and its dyeability: Thiol as a functionalization template of polypropylene
Authors: Choi Yeon Beom , Park O Ok
Published: April 2008

A two‐step process has been invented to prepare sulfonated polypropylene from chlorinated polypropylene via thiolation and successive oxidation to enhance the dyeability of polypropylene. With a short thiolation reaction time of 3 h in an N‐methyl‐2‐pyrrolidone solution, 1.7–20.5% sulfur can be incorporated into a polypropylene bulk effectively. Chlorine–thiol substitution and hydrosulfide conversion have been examined with elemental analysis, and their behaviors as a function of the SH/Cl ratio can be explained with an equilibrium model of hydrosulfide and accessible chlorine in a given timescale. Oxidation of thiol has been performed successfully with hydrogen peroxide. The evolution of oxidation intermediates such as sulfoxide, sulfone, sulfinic acid, and sulfonic acid can be identified by Raman and Fourier transform infrared analyses. Sulfonated polypropylene can be stained by a basic dye very effectively, and its dye uptake reaches 190 mmol of dye/kg of polymer for 3.6 mmol of sulfur/g of polymer. This dye uptake is 20 times more effective than that of chlorinated polypropylene on a molar basis. Thus, it is clear that a modification can be performed effectively to enhance the dyeability of polypropylene. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Digital differential interference contrast autofocus for high‐resolution oil‐immersion microscopy
Authors: Shen Feimo , Hodgson Louis , Price Jeffrey H. , Hahn Klaus M.
Published: April 2008

Continued advances in cellular fluorescent biosensors enable studying intracellular protein dynamics in individual, living cells. Autofocus is valuable in such studies to compensate for temperature drift, uneven substrate over multiple fields of view, and cell growth during long‐term high‐resolution time‐lapse studies of hours to days. Observing cellular dynamics with the highest possible resolution and sensitivity motivates the use of high numerical aperture (NA) oil‐immersion objectives, and control of fluorescence exposure to minimize phototoxicity. To limit phototoxicity, to maximize light throughput of the objective for biosensor studies, and because phase contrast is distorted by the meniscus in microtiter plates, we studied autofocus in differential interference contrast (DIC) microscopy with a 60× 1.45 NA oil objective after removing the analyzer from the fluorescent light path. Based on a study of the experimental DIC modulation transfer function, we designed a new bandpass digital filter for measuring image sharpness. Repeated tests of DIC autofocus with this digital filter on 225 fields‐of‐view resulted in a precision of 8.6 nm (standard deviation). Autofocus trials on specimens with thicknesses from 9.47 to 33.20 μm, controlled by cell plating density, showed that autofocus precision was independent of specimen thickness. The results demonstrated that the selected spatial frequencies enabled very high‐precision autofocus for high NA DIC automated microscopy, thereby potentially removing the problems of meniscus distortion in phase contrast imaging of microtiter plates and rendering the toxicity of additional fluorescence exposure unnecessary. © 2008 International Society for Advancement of Cytometry
Temporally controlled prostate epithelium‐specific gene alterations
Authors: Luchman H. Artee , Friedman Hana C. , Villemaire Michelle L. , Peterson Alan C. , Jirik Frank R.
Published: April 2008

Employing the Hprt locus as the site for targeted transgenesis we have developed mice expressing the tamoxifen‐inducible Cre‐ER(T2) fusion protein under the control of the ARR2‐rat probasin promoter. This system enables external control over the timing of prostate epithelial cell‐specific gene alterations. Using both the ROSA26‐lacZ and ROSA26‐EYFP reporter strains to monitor recombinase activity, Cre‐ER(T2) was found to be specifically expressed in the prostatic epithelium and was strictly tamoxifen dependent. This strain thus allows precise control over the timing of gene alterations in the mouse prostate, enabling analyses of the phenotypic consequences of gene alterations in mice of any age. It also provides an ideal platform to study the impact of environmental, hormonal, and age‐related factors on prostate tumorigenesis. This latter feature will be of particular value given the paucity of murine models that accurately mimic the late onset and prolonged natural history of human prostate cancer. genesis 46:229–234, 2008. © 2008 Wiley‐Liss, Inc.
Analysis of water and food security scenarios for 2025 with the PODIUM model: the case of Agro‐Ecological Region 12 of India
Authors: Singandhupe R. B. , Nanda P. , Panda D. K. , Swain M.
Published: April 2008

The Policy Interactive Dialogue Model (PODIUM), developed by the International Water Management Institute (IWMI), has been used to consider data of 1995 as a base to predict water–food security scenarios for 2025 of Agro‐Ecological Region 12 (AER12) of India having a total geographical area of 26.8 million ha. The model has been used to address the food and water security issues simultaneously and generates alternative scenarios highlighting the interlinkages between water and food security. In this study four scenarios: business as usual scenario (BAU); food security scenario (FS); water security scenario (WS); and water and food security scenario (WFS) have been analysed. The BAU scenario projects that the region AER12 of India will face a food deficit of 7.46 million t in 2025. The total annually renewable water resources of the region will be 40.3 billion m3 in 2025, out of which a maximum of 21.7 billion m3 will be available in Agro‐Ecological Sub Region (AESR12.1), followed by 10.2 and 8.3 billion m3 in AESR12.2 and AESR12.3, respectively. The diversion of available water in all sectors (agriculture, domestic, industry) in AER12 was 15.4 billion m3 in 1995, which is expected to increase by 81.7% in 2025, but due to urbanisation and industrial demand, the available water for the agricultural sector is expected to reduce by 64%. In the industry sector it is projected to jump from 10% in 1995 to 28% in 2025.

After analysing the BAU scenario of the region, some of the specific alternative options have been explored with the PODIUM model by altering the drivers in order to find feasible ways to make the region secure and sustainable with a comfortable level of food and water by 2025. The outcomes of the alternative options are discussed in this paper. Copyright © 2008 John Wiley & Sons, Ltd.
Three‐layered membranes of collagen/hydroxyapatite and chitosan for guided bone regeneration
Authors: Teng Shu‐Hua , Lee Eun‐Jung , Wang Peng , Shin Du‐Sik , Kim Hyoun‐Ee
Published: April 2008

The purpose of this study was to design a novel hybrid membrane with optimized properties for guided bone regeneration (GBR). Both the top and bottom layers of the sandwich‐structured membrane were composed of collagen containing 20 wt% hydroxyapatite (HA), while the middle layer was made of chitosan. The above three layers were formulated into an integral membrane from their respective slurries through a layer‐by‐layer filtration process. The phase and composition of the membrane were confirmed by FT‐IR and XRD analyses. The observation of its morphology by SEM showed that the membrane had a porous structure and structural integrity. The chitosan layer ensured the high tensile strength and elastic modulus of the membrane, while the presence of the collagen/HA composite layers endowed it with good flexibility and bioactivity. These results suggest that the integrated membrane prepared in this study would have the potential for use as a GBR material. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Comparison of postmortem changes in goose cardiac and breast muscles at 5 °C
Authors: Ho Sy‐Shyan , Lin Chia‐Ying , Chou Rong‐Ghi R.
Published: April 2008

BACKGROUD: The tenderness of goose heart is an important consideration in its utilization as a popular meat product. It is generally thought that postmortem degradation of myofibrillar proteins may improved meat tenderness. Little information, however, is available regarding the postmortem changes in goose cardiac muscle. Therefore, the postmortem proteolysis between goose cardiac and breast muscles at 5 °C is compared.

RESULTS: The pH is higher (P < 0.05) in cardiac samples than in breast samples. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis and western blots results indicate that postmortem degradation of titin and desmin and the appearance of the 28 and 30 kDa components are faster in breast muscle than in cardiac muscle.

CONCLUSION: Our results may suggest that goose postmortem proteolysis occurs more rapidly in breast muscle than in cardiac muscle at 5 °C. Copyright © 2008 Society of Chemical Industry
Macromol. Theory Simul. 2–3/2008
Authors: Wang Zheng , Li Baohui , Jin Qinghua , Ding Datong , Shi An‐Chang
Published: April 2008

Cover: The picture on the cover shows a phase diagram for lamella‐forming ABA triblock copolymers confined in cylindrical pores of various diameters (D/L0) and of different surface preferences (α). Schematics of chains in concentric lamellae are given on the right side of the cover. Further details can be found in the article by Z. Wang, B. Li,* Q. Jin, D. Ding, and A.‐C. Shi* on page 86.
Sequence and structural properties of identical mutations with varying phenotypes in human coagulation factor IX
Authors: Chavali Sreenivas , Sharma Amitabh , Tabassum Rubina , Bharadwaj Dwaipayan
Published: April 2008

Mutations in human coagulation factor IX cause an X‐linked bleeding disorder Hemophilia B, which can be classified as severe, moderately severe and mild based on the plasma levels of factor IX among affected individuals with respect to normal factor IX activity assayed in the patients' plasma (<1%, 2–5%, 6–30%, respectively). Recently, we identified hemophilia B to be a disease with mutations showing clinical variation and speculated that this phenotypic heterogeneity might be a replacement‐specific property. Here, we have analyzed the differences in sequence and structural properties among identical mutations with varying phenotypes (IMVPs) by comparing with mutations with uniform phenotypes (MUPs), with recurring reports in Haemophilia B mutation database. Classification of mutations into IMVPs and MUPs has been done based on rigorous systematic evaluation of the clotting activity each mutation is associated with. IMVPs (n = 51) occur in less conserved mutant sites with more tolerated substitutions compared to MUPs (n = 100). A preponderance of CpG site mutations and Arg as the mutated residue in IMVPs compared to Cys in MUPs was observed. Hence, a CpG site substitution at less conserved Arg site might have an increased propensity of expressing variable phenotypes. The changes in intrinsic properties associated with the mutation are less drastic for IMVPs than for MUPs, though no significant differences were observed in structural properties. Based on this study and available literature we speculate that modifier genes at other loci, epigenetic interactions and environment may serve individually or cumulatively to bring about the clinical variation implicating hemophilia B to be deviation from classical Mendelian disorder with complete penetrance. We demonstrate that phenotypic heterogeneity appears to be site‐specific also owing to the lesser conservation of the mutant site. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Some geometric properties of quantum phases and calculation of phase formulas
Authors: Bracken Paul
Published: April 2008

An introduction to several geometrical ideas which are of use to quantum mechanics is presented. The Aharonov‐Anandan phase is introduced and without reference to any dynamical equation, this phase is formulated by defining an appropriate connection on a specific fiber bundle. The holonomy element gives the phase. By introducing another connection, the Pancharatnam phase formula is derived following a different procedure. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Robust control of constrained max‐plus‐linear systems
Authors: Necoara Ion , De Schutter Bart , van den Boom Ton J. J. , Hellendoorn Hans
Published: April 2008

Max‐plus‐linear (MPL) systems are a class of nonlinear systems that can be described by models that are ‘linear’ in the max‐plus algebra. We provide here solutions to the three types of finite‐horizon min–max control problems for uncertain MPL systems, depending on the nature of the control input over which we optimize: open‐loop input sequences, disturbances feedback policies, and state feedback policies. We assume that the uncertainty lies in a bounded polytope and that the closed‐loop input and state sequence should satisfy a given set of linear inequality constraints for all admissible disturbance realizations. Despite the fact that the controlled system is nonlinear, we provide sufficient conditions that allow one to preserve convexity of the optimal value function and its domain. As a consequence, the min–max control problems can be either recast as a linear program or solved via N parametric linear programs, where N is the prediction horizon. In some particular cases of the uncertainty description (e.g. interval matrices), by employing results from dynamic programming, we show that a min–max control problem can be recast as a deterministic optimal control problem. Copyright © 2008 John Wiley & Sons, Ltd.
Ranging error‐tolerable localization in wireless sensor networks with inaccurately positioned anchor nodes
Authors: Fan Rongfei , Jiang Hai , Wu Shaohua , Zhang Naitong
Published: April 2008

Localization is essential for wireless sensor networks (WSNs). It is to determine the positions of sensor nodes based on incomplete mutual distance measurements. In this paper, to measure the accuracy of localization algorithms, a ranging error model for time of arrival (TOA) estimation is given, and the Cramer—Rao Bound (CRB) for the model is derived. Then an algorithm is proposed to deal with the case where (1) ranging error accumulation exists, and (2) some anchor nodes broadcast inaccurate/wrong location information. Specifically, we first present a ranging error‐tolerable topology reconstruction method without knowledge of anchor node locations. Then we propose a method to detect anchor nodes whose location information is inaccurate/wrong. Simulations demonstrate the effectiveness of our algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
Ledrappier’s system is almost mixing of all orders
Authors: ARENAS-CARMONA L. , BEREND D. , BERGELSON V.
Published: April 2008

We consider Ledrappier’s dynamical system, which was the first example of a $\mathbb {Z}^2$-action which is 2-mixing but not 3-mixing. Our main result is that, excluding certain small ‘constructible’ sets, the system is mixing of every order.
The mathematical research of William Parry FRS
Authors: POLLICOTT M. , SHARP R. , TUNCEL S. , WALTERS P.
Published: April 2008

In this article we survey the mathematical research of the late William (Bill) Parry, FRS.
Cusps of Hilbert modular varieties - CORRIGENDUM
Authors: McREYNOLDS D. B.
Published: April 2008

In this paper, the dates when the paper and its revised version were received, were inadvertently omitted. The missing information is:

Received 23 November 2006; revised 26 June 2007
Modelling and prediction of weekly incidence of influenza A specimens in England and Wales
Authors: ŠALTYTĖ BENTH J. , HOFOSS D.
Published: April 2008

We propose a rather simple model, which fits well the weekly human influenza incidence data from England and Wales. A standard way to analyse seasonally varying time-series is to decompose them into different components. The residuals obtained after eliminating these components often do not reveal time dependency and are normally distributed. We suggest that conclusions should not be drawn only on the basis of residuals and that one should consider the analysis of squared residuals. We show that squared residuals can reveal the presence of the remaining seasonal variation, which is not exhibited by the analysis of residuals, and that the modelling of such seasonal variations undoubtedly improves model fit.
The biochemistry of drugs and doping methods used to enhance aerobic sport performance
Authors: Cooper Chris E.
Published: April 2008

Optimum performance in aerobic sports performance requires an efficient delivery to, and consumption of, oxygen by the exercising muscle. It is probable that maximal oxygen uptake in the athlete is multifactorial, being shared between cardiac output, blood oxygen content, muscle blood flow, oxygen diffusion from the blood to the cell and mitochondrial content. Of these, raising the blood oxygen content by raising the haematocrit is the simplest acute method to increase oxygen delivery and improve sport performance. Legal means of raising haematocrit include altitude training and hypoxic tents. Illegal means include blood doping and the administration of EPO (erythropoietin). The ability to make EPO by genetic means has resulted in an increase in its availability and use, although it is probable that recent testing methods may have had some impact. Less widely used illegal methods include the use of artificial blood oxygen carriers (the so-called ‘blood substitutes’). In principle these molecules could enhance aerobic sports performance; however, they would be readily detectable in urine and blood tests. An alternative to increasing the blood oxygen content is to increase the amount of oxygen that haemoglobin can deliver. It is possible to do this by using compounds that right-shift the haemoglobin dissociation curve (e.g. RSR13). There is a compromise between improving oxygen delivery at the muscle and losing oxygen uptake at the lung and it is unclear whether these reagents would enhance the performance of elite athletes. However, given the proven success of blood doping and EPO, attempts to manipulate these pathways are likely to lead to an ongoing battle between the athlete and the drug testers.
Time-of-flight spectroscopy of the energy distribution of laser-ablated atoms and ions
Authors: Buchsbaum A. , Rauchbauer G. , Varga P. , Schmid M.
Published: April 2008

The growth of ultrathin films, deposited by laser ablation, crucially depends on the energy of the ablated species. Therefore, a time-of-flight (TOF) spectrometer has been constructed and measurements have been carried out in order to determine the energy distribution of laser-ablated Fe and Pt atoms and ions in the plasma created by nanosecond pulses of a frequency-doubled neodymium doped yttrium aluminum garnet laser. The experiments have been performed in ultrahigh vacuum at relatively low laser power. For measuring the spectra of the neutrals, a cross-beam electron source for postionization and electric as well as magnetic fields for repelling the ions are employed. Nevertheless, measurements of neutral particles are restricted to low plasma densities due to electrostatic shielding within the plasma, leading to an inefficient deflection of charged particles by electrostatic and magnetic fields. Test measurements have been performed by utilizing the TOF spectrometer as a pressure gauge and also by chopping the electron beam, running the TOF spectrometer as a residual gas mass spectrometer. The spectra of the laser-ablated plasmas have shown plasma conditions with a Debye length of approximately 10−4m, densities of 1015–1016m−3 and ion energies up to 150eV. Neutral spectra have shown an unexpectedly low fraction of neutrals (10−3–10−4) and hyperthermal energies up to several 10eV, possibly contributed by recombination of ions and electrons in the plasma. Even though gas spectra had demonstrated the expected sensitivity of the TOF spectrometer for low-energy neutrals, no thermally evaporated neutral atoms could be found.
Phonon screening in photochemically doped zinc oxide nanocrystals
Authors: Yamamoto S. , Mishina T.
Published: April 2008

Persistent absorption bleaching and resonant Raman scattering are measured in ZnO nanocrystal films photochemically doped with electrons. A prominent intensity change and a slight redshift are observed in the Raman spectra as a result of the doping. The redshift is assigned to screening of the LO phonon by the doped electrons and intensity change is regarded as a result of the change in the capture rate of the excitons by the surface states.
Effect of ultrathin buffer on the microstructure of highly mismatched epitaxial ZnO films on Al2O3 (0001)
Authors: Kim In-Woo , Lee Kyu-Mann
Published: April 2008

The effect of the ultra thin (4nm) ZnO buffer layer grown at a low temperature of 300°C on the microstructural evolution of highly mismatched ZnO∕Al2O3(0001) films was investigated. Based on the real time synchrotron x-ray scattering, atomic force microscopy, and high resolution electron microscopy, it was shown that the ultrathin two-dimensional (2D) layers play a critical role for improving the ZnO layer quality by inducing 2D growth mode instead of three-dimensional mode at 500°C in early stage. The ZnO films grown on the ultrathin buffer exhibited structural coherence between the surface and the interface in the substrate normal direction in early stage. The great enhancement of the microstructural quality was attributed to the strain accommodation by the 2D ultrathin buffer.
Effect of grazing strategy, ryegrass overdrilling and herbicide application on vulpia content, tiller density and seed production in perennial pastures
Authors: Tozer K. N. , Chapman D. F. , Quigley P. E. , Dowling P. M. , Cousens R. D. , Kearney G. A.
Published: April 2008

Vulpia species C.C. Gmel. are annual grass weeds that can reduce the productivity of perennial pastures throughout southern Australia. To develop more effective strategies to manage vulpia, a 3-year experiment was established in western Victoria (average annual rainfall: 625 mm) comparing different methods currently used to control this weed. Overdrilling perennial ryegrass (Lolium perenne L.) seed and simazine application treatments were applied to phalaris (Phalaris aquatica L.) pastures that were set-stocked or rotationally grazed (either as a four-paddock or strategic rotation) with Merino ewes. The content of vulpia, subterranean clover (Trifolium subterraneum L.) and other annual grasses as a proportion of total dry matter increased, and the proportion of phalaris decreased in most grazing treatments throughout the experiment. The mean vulpia content was lowest and the phalaris content was highest in the four-paddock rotation, whereas vulpia content was greatest and phalaris content was lowest under set-stocking. Simazine application in June with or without ryegrass overdrilling reduced the number of vulpia tillers/m2 in 2000 and 2001 and vulpia panicle production in 2000, although vulpia populations increased to pretreatment levels in herbicide-treated swards by 2002. The number of vulpia seeds in the soil seed bank was not affected by any of the treatments. The most effective treatment was a combination of ryegrass overdrilling and herbicide application in the four-paddock, rotationally grazed pastures. This experiment highlights the need for an integrated approach to manage vulpia since relying on herbicide application alone is ineffective. This is particularly the case when competitive pasture species are unable to adequately utilise available resources and prevent a recovery in vulpia populations.
Water management as a future necessity in sheep feedlots
Authors: Pluske J. M. , Schlink A. C.
Published: April 2008

Improving water management in rural towns such as Wagin, Western Australia, will decrease infrastructure damage caused by water and salinity and produce a ‘new water’ resource. The aim of this paper is to predict feedlot water demand using a bioeconomic model, H20Sheep, to determine if using such a ‘new water’ resource could be a viable option for this production system. Wagin (–33.3075 S, 117.3403 E), a township south-east of Perth, was chosen as the specific location for a sheep feedlot producing prime lambs. In this paper, the H20Sheep model was used to show how feedlot returns are influenced by the price of water, different feeding regimens and climate change. This was done by integrating feed and water intake of lambs, general feedlot water use and waste disposal. To show relative sensitivity of changing other model parameters that are not directly connected with water, changes in the purchase and sale price of lambs were also investigated. As might be expected, H20Sheep shows that returns from a sheep feedlot enterprise can be extremely sensitive to changes in lamb purchase (just over 7% increase will result in negative returns) and sale prices (a 4% decrease will generate a negative outcome). With respect to water, the findings indicate that, while increases in water use in the feedlot and price have to be greater than the increase in relative price of sheep, monitoring the biological parameters associated with water as well as water prices is still important both from a management and an economic perspective. Hence, if towns involved in the Rural Towns – Liquid Assets project, such as Wagin, decide to sell their water, the relevant policy makers should ensure that the sale price enables an effective water management system for the town and is also attractive to end-users such as feedlots.
Pushing for answers: is myosin V directly involved in moving mitochondria?
Authors: Valiathan Rajeshwari R. , Weisman Lois S.
Published: April 2008

In budding yeast, the actin-based class V myosin motors, Myo2 and Myo4, transport virtually all organelles from mother to bud during cell division. Until recently, it appeared that mitochondria may be an exception, with studies showing that the Arp2/3 complex is required for their movement. However, several recent studies have proposed that Myo2 has a direct involvement in mitochondria inheritance. In this issue, Altmann et al. (Altmann, K., M. Frank, D. Neumann, S. Jakobs, and B. Westermann. 2008. J. Cell Biol. 181:119–130) provide the strongest support yet that Myo2 and its associated light chain Mlc1 function directly and significantly in both mitochondria–actin interactions and in the movement of mitochondria from mother to bud. The conflicting functions of Arp 2/3 and Myo2 may be reconciled by the existence of multiple pathways involved in mitochondrial transport.
Predicting zebra mussel fouling on native mussels from physicochemical variables
Authors: JOKELA ANNELI , RICCIARDI ANTHONY
Published: April 2008

1. Predictive models of impact are needed for the risk assessment of invasive species. One such species is the Eurasian zebra mussel (Dreissena polymorpha), a fouling bivalve that overgrows and kills native mussels (Unionidae) in many North American lakes and rivers. The level of mortality in a native mussel population increases with the fouling intensity – i.e. the mean number of zebra mussels attached to each native mussel.

2. We conducted a multi‐site survey within the St Lawrence and Richelieu rivers (Quebec, Canada) to determine whether zebra mussel fouling intensity can be predicted from environmental variables. We found fouling intensity to be positively correlated with calcium concentration [Ca2+] and negatively correlated with sediment size, but not affected by local macrophyte cover.

3. A multiple regression model that includes calcium concentration and sediment size explains 86% of variation in fouling intensity across all sites.

4. Analysis of data from invaded sites in North America and Europe revealed a nonlinear relationship in which fouling intensity increases with calcium concentration up to an asymptotic threshold of 24 mg L−1 Ca2+.

5. Our results suggest that the community‐level impacts of zebra mussels are mediated by abiotic environmental variables and gradients in these variables may provide local habitat refugia for native mussels.
Teaching Computer Studies: an investigation based on teachers' lesson diaries
Authors: Moore J.
Published: April 2008

Abstract In preparation for a programme of pre‐service and inservice teacher training, information was obtained on the teaching of Computer Studies to pupils aged 14 – 16 years. A structured document, the Lesson Diary Report Form (LDRF), completed by classroom teachers was used to gather data on nearly 700 lessons involving 1800 pupils. Information was obtained about the lesson type, the use of resources by teachers and pupils, homework assignments, and the timing of classroom activities.

Analysis of the data showed many similarities and only a few differences between lessons given in the first and second years of the two‐year course. It was found that teacher training in Computer Studies teaching was a significant variable in deciding the choice of lesson type and the use of resources. No consistent pattern of lesson adaptation to pupils of different abilities was found.
The role of computer‐aided modelling in learning physics
Authors: Niedderer H. , Schecker H. , Bethge T.
Published: April 2008

Abstract Physics education should take the chance to link research about students' alternative frameworks and new teaching strategies with the use of modern information technology tools. The article shows how iconic model building software like STELLA can be used to help students gain a deeper qualitative conceptual understanding.