bluuebunny/crossref_metadata_2025 huggingface dataset:
The Plant Defense Elicitor Cryptogein Stimulates Clathrin-Mediated Endocytosis Correlated with Reactive Oxygen Species Production in Bright Yellow-2 Tobacco Cells
Authors: Leborgne-Castel Nathalie , Lherminier Jeannine , Der Christophe , Fromentin Jérôme , Houot Valérie , Simon-Plas Françoise
Published: January 2008

The plant defense elicitor cryptogein triggers well-known biochemical events of early signal transduction at the plasma membrane of tobacco (Nicotiana tabacum) cells, but microscopic observations of cell responses related to these early events were lacking. We determined that internalization of the lipophilic dye FM4-64, which is a marker of endocytosis, is stimulated a few minutes after addition of cryptogein to tobacco Bright Yellow-2 (BY-2) cells. This stimulation is specific to the signal transduction pathway elicited by cryptogein because a lipid transfer protein, which binds to the same receptor as cryptogein but without triggering signaling, does not increase endocytosis. To define the nature of the stimulated endocytosis, we quantified clathrin-coated pits (CCPs) forming on the plasma membrane of BY-2 cells. A transitory stimulation of this morphological event by cryptogein occurs within the first 15 min. In the presence of cryptogein, increases in both FM4-64 internalization and clathrin-mediated endocytosis are specifically blocked upon treatment with 5 μ  m tyrphostin A23, a receptor-mediated endocytosis inhibitor. The kinetics of the transient increase in CCPs at the plasma membrane coincides with that of transitory reactive oxygen species (ROS) production occurring within the first 15 min after elicitation. Moreover, in BY-2 cells expressing NtrbohD antisense cDNA, which are unable to produce ROS when treated with cryptogein, the CCP stimulation is inhibited. These results indicate that the very early endocytic process induced by cryptogein in tobacco is due, at least partly, to clathrin-mediated endocytosis and is dependent on ROS production by the NADPH oxidase NtrbohD.
Horseradish Peroxidase‐Catalyzed Generation of Acetophenone and Benzophenone in the Triplet State*
Authors: Nantes Lseli L. , Becharat Etelvino J. H. , Cilento Giuseppe
Published: January 2008

Horseradish peroxidase catalyzes the aerobic oxidation of 2‐phenylpropanal and diphenylacetaldehyde at physiological pH to yield acetophenone and benzophenone partly in the triplet state, respectively. These excited products plus formic acid are expected from the thermolysis of dioxetane intermediates. The presence of acetophenone was demonstrated spectrophotometr‐ically and the chemiluminescence spectrum (δmax ‐ 430 nm) was consistent with its triplet state. Energy transfer to 9,10‐dibromoanthracene‐2‐sulfonate ion, a triplet carbonyl counter, but not to anthracene‐2‐sulfonate ion, a singlet carbonyl acceptor, occurred, confirming the triplet nature of the main emitter. In the case of the diphenylacetaldehydelperoxidase system, benzophenone could also be detected spectrophotometrically but the corresponding chemiluminescence spectrum showed only red emission (δmax ‐ 630 nm), which was tentatively attributed to singlet oxygen formed by triplet‐triplet energy transfer to ground state oxygen. Horseradish peroxidase can be replaced by other he‐meproteins such as myoglobin, hemoglobin and micro‐peroxidase as catalyst of the chemiluminescent reaction. The distinct emission spectra achieved with different hemeproteins suggest a role of the microenvi‐ronment in totally or partly protecting the excited species from oxygen collisions, resulting in emission maxima around 430 nm, 630 nm or both.
Anthocyanin Content and UVB Sensitivity in Brassica rap
Authors: Klaper Rebecca , Frankel Steven , Berenbaum May R.
Published: January 2008

Three genotypes of rapid‐cycling Brassica rapa that differ in anthocyanin content were grown in the presence and absence of elevated levels of shortwave ultraviolet (UVB, 280–325 nm) radiation. After 41 days, UVB exposure reduced leaf length and plant height of all genotypes. Plants with low levels of anthocyanin experienced a reduction in flower number twice as great as in genotypes with normal or elevated levels of anthocyanins; however, the absence of differences in flower production by genotypes with normal and elevated levels of anthocyanins suggests that factors other than anthocyanin pigmentation contribute to UVB responses in this species.
The Selective Uptake of Benzoporphyrin Derivative Mono‐Acid Ring A Results in Differential Cell Kill of Multiple Myeloma Cells in vitro
Authors: Glück Stefan , Chadderton Antony , Ho Anthony D.
Published: January 2008

High‐dose chemotherapy (HDCT) and autologous bone marrow/blood stem cell transplantation are an effective combination for treating a number of malignant disorders. The contamination of the autograft by malignant cells may be a reason for recurrences in spite of this treatment, for instance, in multiple myeloma. Therefore, we evaluated the use of photodynamic therapy (PDT) using the photosensitizer benzoporphyrin derivative mono‐acid ring A (BPD‐MA) on multiple myeloma cells in comparison to the components of the normal bone marrow (NBM) and peripheral blood apheresis product. Flow cytometry was used to measure differential BPDMA uptake of NBM components: namely lymphocytes, monocytes, granulocytes and enriched hematopoietic stem cell (CD34+) populations and also the multiple myeloma cell lines OCI‐MY7 and OCI‐MY4. When each population was measured individually, the order of uptake was [OCI‐MY7/MY4] > [CD34+] > [granulocytes] = [monocytes] ≫ [lymphocytes]. Further, clonogenic assay was used to demonstrate surviving fractions for OCI‐MY7, OCI‐MY4 and NBM in vitro. The LD90 for OCI‐MY7 and OCI‐MY4 was between 10 and 20 ng/mL BPD‐MA whereas this concentration did not show any significant cell kill for the colony‐forming units‐granulocyte/macrophage (CFU‐GM) and burst‐forming units—erythrocyte (BFU‐E). When the NBM was “contaminated” with multiple myeloma cells in vitro, the LD90 for OCI‐MY7 in this cell mixture was shifted to between 40 and 80 ng/mL BPD‐MA. However, at 40 ng/ mL BPD‐MA at least 50% of normal CFU‐GM and BFU‐E colonies survived. For CFU‐GM and BFU‐E derived from the enriched CD34+ cell population, BPDMA up to a concentration of 80 ng/mL did not significantly reduce the surviving fractions. We have observed a 3–4 log therapeutic window with differential cell kill when comparing multiple myeloma cell lines to the components of the NBM and apheresis product in vitro. We conclude, that BPD‐MA is a molecule potentially useful as an ex vivo purging agent.
Photodynamic Action of Methylene Blue on the Paramecium Membrane
Authors: Saitow Fumihito , Nakaoka Yasuo
Published: January 2008

An electrophysiological study of photodynamic action on the Paramecium membrane was carried out. In the presence of methylene blue (MB), light‐spot stimulation of an anterior and a posterior part induced a depolarization and a hyperpolarization of the membrane, respectively. Under voltage‐clamping, the anterior stimulation induced an inward current, while the posterior stimulation induced an outward current. The amplitudes of these currents were dependent on the membrane potential. When K+ channels were blocked with Cs+ and tetraethylammonium (TEA+), the posterior outward current was inhibited, while the anterior inward current was not inhibited. Intracellular application of the Ca2+ chelator, 1,2‐bis (2‐aminophenoxy) ethane‐N,N,N',N'‐tetraacetic acid (BAPTA) also inhibited the posterior outward current, but the anterior inward current was unaffected. These results suggest that photodynamic action on the Paramecium membrane primarily opens the Ca2+ channels and the following influx of Ca2+ activates the Ca2+‐dependent K+ channels localized mainly on the posterior part of the membrane.
Comparison of Experimental and Numerical Air Temperature Distributions Behind a Cylindrical Volumetric Solar Absorber Module
Authors: Palero Silvia , Romero Manuel , Castillo José L.
Published: January 2008

The current trend in volumetric solar receiver technology is to build modular receivers cooled by air (Hitrec I and II, Solair 200kW and 3MW) in order to facilitate the replacement of broken absorber modules (cups) and to simplify the upscaling of the receiver. In addition, the modular designs include an air return circuit to cool down the structure supporting the cups. Usually, the air outlet temperature from each module is characterized by measurements taken from a single thermocouple. However, the air temperature distribution behind the volumetric absorber module is not homogeneous, as it can be seen in some specific tests where several thermocouples were added behind different absorber modules. The radial distribution of outlet air temperatures shows very high temperature gradients. The goal of this work is to explain the inhomogeneous thermal maps behind the metallic absorbers by comparing some experimental results with numerical simulations performed using the computational fluid dynamics FLUENT code. The results show the wind influence over the air recirculation flow and its effects on the outlet air temperature radial distribution. Thus, the simulations suggest different ways to reduce the temperature gradients behind each cup.
Well-To-Wheel Analysis of Solar Hydrogen Production and Utilization for Passenger Car Transportation
Authors: Felder Remo , Meier Anton
Published: January 2008

A well-to-wheel analysis is conducted for solar hydrogen production, transport, and usage in future passenger car transportation. Solar hydrogen production methods and selected conventional production technologies are examined using a life cycle assessment. Utilization of hydrogen in fuel cells is compared with advanced gasoline and diesel powertrains. Solar scenarios show distinctly lower greenhouse gas (GHG) emissions than fossil-based scenarios. For example, using solar hydrogen in fuel cell cars reduces life cycle GHG emissions by 70% compared to advanced fossil fuel powertrains and by more than 90% if car and road infrastructure are not considered. Solar hydrogen production allows a reduction of fossil energy requirements by a factor of up to 10 compared to using conventional technologies. Major environmental impacts are associated with the construction of the steel-intensive infrastructure for solar energy collection due to mineral and fossil resource consumption as well as discharge of pollutants related to today’s steel production technology.
Application of an Internally Circulating Fluidized Bed for Windowed Solar Chemical Reactor with Direct Irradiation of Reacting Particles
Authors: Kodama Tatsuya , Enomoto Syu-ichi , Hatamachi Tsuyoshi , Gokon Nobuyuki
Published: January 2008

Solar thermochemical processes require the development of a high-temperature solar reactor operating at 1000–1500°C, such as solar gasification of coal and the thermal reduction of metal oxides as part of a two-step water splitting cycle. Here, we propose to apply “an internally circulating fluidized bed” for a windowed solar chemical reactor in which reacting particles are directly illuminated. The prototype reactor was constructed in a laboratory scale and demonstrated on CO2 gasification of coal coke using solar-simulated, concentrated visible light from a sun simulator as the energy source. About 12% of the maximum chemical storage efficiency was obtained by the solar-simulated gasification of the coke.
Towards the Industrial Solar Carbothermal Production of Zinc
Authors: Epstein Michael , Olalde Gabriel , Santén Sven , Steinfeld Aldo , Wieckert Christian
Published: January 2008

Based on the experimental results of a 300kW solar chemical pilot plant for the production of zinc by carbothermal reduction of ZnO, we performed a conceptual design of a 5MW demonstration plant and of a 30MW commercial plant. Zinc can be used as a fuel for zinc-air batteries and fuel cells, or it can be reacted with water to form high-purity hydrogen. In either case, the chemical product is ZnO, which in turn is solar recycled to zinc. The proposed thermochemical process provides an energy efficient route for the conversion, storage, and transportation of solar energy in the form of solar fuels.
Recognition of a Ubiquitous Self Antigen by Prostate Cancer-Infiltrating CD8
+
T Lymphocytes
Authors: Savage Peter A. , Vosseller Keith , Kang Chulho , Larimore Kevin , Riedel Elyn , Wojnoonski Kathleen , Jungbluth Achim A. , Allison James P.
Published: January 2008

Substantial evidence exists that many tumors can be specifically recognized by CD8
+
T lymphocytes. The definition of antigens targeted by these cells is paramount for the development of effective immunotherapeutic strategies for treating human cancers. In a screen for endogenous tumor-associated T cell responses in a primary mouse model of prostatic adenocarcinoma, we identified a naturally arising CD8
+
T cell response that is reactive to a peptide derived from histone H4. Despite the ubiquitous nature of histones, T cell recognition of histone H4 peptide was specifically associated with the presence of prostate cancer in these mice. Thus, the repertoire of antigens recognized by tumor-infiltrating T cells is broader than previously thought and includes peptides derived from ubiquitous self antigens that are normally sequestered from immune detection.
Comment on "The Southern Ocean Biological Response to Aeolian Iron Deposition"
Authors: Boyd Philip W. , Mackie Douglas
Published: January 2008

Cassar
et al
. (Reports, 24 August 2007, p. 1067) proposed that aerosol-iron input enhances Southern Ocean export production. Their conclusion critically depends upon aerosol-iron modeling simulations not validated with iron-deposition data and dust dissolution rates based on Northern Hemisphere atmospheric chemical conditions (low pH). This diminishes the relevance of their findings and demonstrates that applying such models to this region is premature.
Response to Comment on "The Southern Ocean Biological Response to Aeolian Iron Deposition"
Authors: Cassar Nicolas , Bender Michael L. , Barnett Bruce A. , Fan Songmiao , Moxim Walter J. , Levy Hiram , Tilbrook Bronte
Published: January 2008

Net community production in the Southern Ocean is correlated with simulated local dust deposition, and more so with modeled deposition of soluble iron. Model simulations of the latter two properties are consistent with observations in both hemispheres. These results provide strong evidence that aerosol iron deposition is a first-order control on net community production and export production over large areas of the Southern Ocean.
Endothelial Progenitor Cells Control the Angiogenic Switch in Mouse Lung Metastasis
Authors: Gao Dingcheng , Nolan Daniel J. , Mellick Albert S. , Bambino Kathryn , McDonnell Kevin , Mittal Vivek
Published: January 2008

Angiogenesis-mediated progression of micrometastasis to lethal macrometastasis is the major cause of death in cancer patients. Here, using mouse models of pulmonary metastasis, we identify bone marrow (BM)–derived endothelial progenitor cells (EPCs) as critical regulators of this angiogenic switch. We show that tumors induce expression of the transcription factor Id1 in the EPCs and that suppression of Id1 after metastatic colonization blocked EPC mobilization, caused angiogenesis inhibition, impaired pulmonary macrometastases, and increased survival of tumor-bearing animals. These findings establish the role of EPCs in metastatic progression in preclinical models and suggest that selective targeting of EPCs may merit investigation as a therapy for cancer patients with lung metastases.
Designed Protein-Protein Association
Authors: Grueninger Dirk , Treiber Nora , Ziegler Mathias O. P. , Koetter Jochen W. A. , Schulze Monika-Sarah , Schulz Georg E.
Published: January 2008

The analysis of natural contact interfaces between protein subunits and between proteins has disclosed some general rules governing their association. We have applied these rules to produce a number of novel assemblies, demonstrating that a given protein can be engineered to form contacts at various points of its surface. Symmetry plays an important role because it defines the multiplicity of a designed contact and therefore the number of required mutations. Some of the proteins needed only a single side-chain alteration in order to associate to a higher-order complex. The mobility of the buried side chains has to be taken into account. Four assemblies have been structurally elucidated. Comparisons between the designed contacts and the results will provide useful guidelines for the development of future architectures.
Keeping Time
Authors: Gray Stephen
Published: January 2008

Introduction to Quantum Mechanics
. A Time-Dependent Perspective.
By David J. Tannor
. University Science, Sausalito, CA, 2007. 686 pp. $84.50. ISBN 9781891389238.

The author offers a new approach to presenting quantum mechanics in upper-level undergraduate and graduate courses in physical chemistry.
Dendritic Cell-Induced Memory T Cell Activation in Nonlymphoid Tissues
Authors: Wakim Linda M. , Waithman Jason , van Rooijen Nico , Heath William R. , Carbone Francis R.
Published: January 2008

Secondary lymphoid organs are dominant sites of T cell activation, although many T cells are subsequently retained within peripheral tissues. Currently, these nonlymphoid compartments are viewed as sites only of effector T cell function, without the involvement of renewed induction of immunity via the interactions with professional antigen-presenting cells. We describe a method of reactivation of herpes simplex virus to examine the stimulation of tissue-resident T cells during secondary challenge. The results revealed that memory CD8
+
T cell responses can be initiated within peripheral tissues through a tripartite interaction that includes CD4
+
T cells and recruited dendritic cells. These findings lend evidence for the existence of a sophisticated T cell response mechanism in extra-lymphoid tissues that can act to control localized infection.
Membrane Phosphatidylserine Regulates Surface Charge and Protein Localization
Authors: Yeung Tony , Gilbert Gary E. , Shi Jialan , Silvius John , Kapus Andras , Grinstein Sergio
Published: January 2008

Electrostatic interactions with negatively charged membranes contribute to the subcellular targeting of proteins with polybasic clusters or cationic domains. Although the anionic phospholipid phosphatidylserine is comparatively abundant, its contribution to the surface charge of individual cellular membranes is unknown, partly because of the lack of reagents to analyze its distribution in intact cells. We developed a biosensor to study the subcellular distribution of phosphatidylserine and found that it binds the cytosolic leaflets of the plasma membrane, as well as endosomes and lysosomes. The negative charge associated with the presence of phosphatidylserine directed proteins with moderately positive charge to the endocytic pathway. More strongly cationic proteins, normally associated with the plasma membrane, relocalized to endocytic compartments when the plasma membrane surface charge decreased on calcium influx.
Considerable Differences in Vaccine Immunogenicities and Efficacies Related to the Diluent Used for Aluminum Hydroxide Adjuvant
Authors: Lin Lin , Ibrahim Ashraf S. , Avanesian Valentina , Edwards John E. , Fu Yue , Baquir Beverlie , Taub Rebecca , Spellberg Brad
Published: January 2008

We are developing an anticandidal vaccine using the recombinant N terminus of Als3p (rAls3p-N). We report that although more rAls3p-N was bound by aluminum hydroxide diluted in saline than by aluminum hydroxide diluted in phosphate-buffered saline (PBS), its immunogenicity and efficacy were superior in PBS. Thus, protein binding, by itself, may not predict the efficacy of some vaccines with aluminum adjuvants.
Endophthalmitis Caused by
Acinetobacter baumannii
: Report of Two Cases
Authors: Chen Kuan-Jen , Hou Chiun-Ho , Sun Ming-Hui , Lai Chi-Chun , Sun Chi-Chin , Hsiao Ching-Hsi
Published: January 2008

Acinetobacter baumannii
is most often responsible for hospital-acquired infections and is occasionally associated with community-acquired infections. We report two cases of
A. baumannii
endophthalmitis, one with endogenous endophthalmitis and the other with postkeratoplasty endophthalmitis. Although endophthalmitis is rare, ophthalmologists should be alert to the possibility of patients having endophthalmitis caused by
A. baumannii
.
Prospective Study of Human Metapneumovirus Detection in Clinical Samples by Use of Light Diagnostics Direct Immunofluorescence Reagent and Real-Time PCR
Authors: Landry Marie L. , Cohen Sandra , Ferguson David
Published: January 2008

A Light Diagnostics human metapneumovirus (HMPV) monoclonal antibody reagent was evaluated using cytospin-enhanced direct immunofluorescence (DFA), and the results were compared to those for TaqMan reverse transcription-PCR (RT-PCR). Of the 202 samples tested, 48 were positive by RT-PCR, and 41 (85.4%) of these were positive by DFA (
P
= 0.0771). The commercial availability of an HMPV DFA reagent will be of significant benefit to clinical laboratories.
Geometric Mismatches within the Concentric Layers of Rotavirus Particles: a Potential Regulatory Switch of Viral Particle Transcription Activity
Authors: Libersou Sonia , Siebert Xavier , Ouldali Malika , Estrozi Leandro F. , Navaza Jorge , Charpilienne Annie , Garnier Pascale , Poncet Didier , Lepault Jean
Published: January 2008

Rotaviruses are prototypical double-stranded RNA viruses whose triple-layered icosahedral capsid constitutes transcriptional machinery activated by the release of the external layer. To understand the molecular basis of this activation, we studied the structural interplay between the three capsid layers by electron cryo-microscopy and digital image processing. Two viral particles and four virus-like particles containing various combinations of inner (VP2)-, middle (VP6)-, and outer (VP7)-layer proteins were studied. We observed that the absence of the VP2 layer increases the particle diameter and changes the type of quasi-equivalent icosahedral symmetry, as described by the shift in triangulation number (T) of the VP6 layer (from T = 13 to T = 19 or more). By fitting X-ray models of VP6 into each reconstruction, we determined the quasi-atomic structures of the middle layers. These models showed that the VP6 lattices, i.e., curvature and trimer contacts, are characteristic of the particle composition. The different functional states of VP6 thus appear as being characterized by trimers having similar conformations but establishing different intertrimeric contacts. Remarkably, the external protein VP7 reorients the VP6 trimers located around the fivefold axes of the icosahedral capsid, thereby shrinking the channel through which mRNA exits the transcribing rotavirus particle. We conclude that the constraints arising from the different geometries imposed by the external and internal layers of the rotavirus capsid constitute a potential switch regulating the transcription activity of the viral particles.
The DNA Deaminase Activity of Human APOBEC3G Is Required for Ty1, MusD, and Human Immunodeficiency Virus Type 1 Restriction
Authors: Schumacher April J. , Haché Guylaine , MacDuff Donna A. , Brown William L. , Harris Reuben S.
Published: January 2008

Human APOBEC3G and several other APOBEC3 proteins have been shown to inhibit the replication of a variety of retrotransposons and retroviruses. All of these enzymes can deaminate cytosines within single-strand DNA, but the overall importance of this conserved activity in retroelement restriction has been questioned by reports of deaminase-independent mechanisms. Here, three distinct retroelements, a yeast retrotransposon, Ty1, a murine endogenous retrovirus, MusD, and a lentivirus, human immunodeficiency virus type 1 (HIV-1), were used to evaluate the relative contributions of deaminase-dependent and -independent mechanisms. Although human APOBEC3G can restrict the replication of all three of these retroelements, APOBEC3G lacking the catalytic glutamate (E259Q) was clearly defective. This phenotype was particularly clear in experiments with low levels of APOBEC3G expression. In contrast, purposeful overexpression of APOBEC3G-E259Q was able to cause modest to severe reductions in the replication of Ty1, MusD, and HIV-1(ΔVif). The importance of these observations was highlighted by data showing that CEM-SS T-cell lines expressing near-physiologic levels of APOBEC3G-E259Q failed to inhibit the replication of HIV-1(ΔVif), whereas similar levels of wild-type APOBEC3G fully suppressed virus infectivity. Despite the requirement for DNA deamination, uracil DNA glycosylase did not modulate APOBEC3G-dependent restriction of Ty1 or HIV-1(ΔVif), further supporting prior studies indicating that the major uracil excision repair system of cells is not involved. In conclusion, the absolute requirement for the catalytic glutamate of APOBEC3G in Ty1, MusD, and HIV-1 restriction strongly indicates that DNA cytosine deamination is an essential part of the mechanism.
New regimen for eccentric calf-muscle training in patients with chronic insertional Achilles tendinopathy: results of a pilot study
Authors: Jonsson P , Alfredson H , Sunding K , Fahlström M , Cook J
Published: January 2008

Background:

Chronic painful insertional Achilles tendinopathy is seen in both physically active and non-active individuals. Painful eccentric training, where the patients load the Achilles tendon into full dorsiflexion, has shown good results in patients with mid-portion Achilles tendinosis. However, only 32% of patients with insertional Achilles tendinopathy had good clinical results with that type of eccentric training regimen.

Aim:

To investigate whether a new model of painful eccentric training had an effect on chronic painful insertional Achilles tendinopathy.

Patients and methods:

27 patients (12 men, 15 women, mean age 53 years) with a total of 34 painful Achilles tendons with a long duration of pain (mean 26 months), diagnosed as insertional Achilles tendinopathy, were included. The patients performed a new model of painful eccentric training regimen without loading into dorsiflexion. This was done as 3×15 reps, twice a day, 7 days/week, for 12 weeks. Pain during Achilles-tendon-loading activity (VAS) and patient’s satisfaction (back to previous activity) were evaluated.

Results:

At follow-up (mean 4 months) 18 patients (67%, 23/34 tendons) were satisfied and back to their previous tendon-loading activity. Their mean VAS had decreased from 69.9 (SD 18.9) to 21 (SD 20.6) (p<0.001). Nine patients (11 tendons) were not satisfied with the treatment, although their VAS was significantly reduced from 77.5 (8.6) to 58.1 (14.8) (p<0.01).

Conclusion:

In this short-term pilot study this new model of painful eccentric calf-muscle training showed promising clinical results in 67% of the patients.
MULTILAYER NONNEGATIVE MATRIX FACTORIZATION USING PROJECTED GRADIENT APPROACHES
Authors: CICHOCKI ANDRZEJ , ZDUNEK RAFAL
Published: January 2008

The most popular algorithms for Nonnegative Matrix Factorization (NMF) belong to a class of multiplicative Lee-Seung algorithms which have usually relative low complexity but are characterized by slow-convergence and the risk of getting stuck to in local minima. In this paper, we present and compare the performance of additive algorithms based on three different variations of a projected gradient approach. Additionally, we discuss a novel multilayer approach to NMF algorithms combined with multi-start initializations procedure, which in general, considerably improves the performance of all the NMF algorithms. We demonstrate that this approach (the multilayer system with projected gradient algorithms) can usually give much better performance than standard multiplicative algorithms, especially, if data are ill-conditioned, badly-scaled, and/or a number of observations is only slightly greater than a number of nonnegative hidden components. Our new implementations of NMF are demonstrated with the simulations performed for Blind Source Separation (BSS) data.
IRREGULAR SAMPLING IN SHIFT INVARIANT SPACES OF HIGHER DIMENSIONS
Authors: ERICSSON STEFAN
Published: January 2008

We consider irregular sampling in shift invariant spaces V of higher dimensions. The problem that we address is: find ε so that given perturbations (λk) satisfying sup |λk| < ε, we can reconstruct an arbitrary function f of V as a Riesz basis expansions from its irregular sample values f(k + λk). A framework for dealing with this problem is outlined and in which one can explicitly calculate sufficient limits ε for the reconstruction. We show how it works in two concrete situations.
THE IMPACT OF ENTREPRENEURIAL ORIENTATION AND OWNERSHIP TYPE ON FIRM PERFORMANCE IN THE EMERGING REGION OF CHINA
Authors: TANG JINTONG , TANG ZHI , ZHANG YULI , LI QIANWEN
Published: January 2008

Entrepreneurial orientation (EO) has been widely studied in the US context, but its examination in emerging regions such as China has been very limited. In this study, we investigate the EO-performance relationship in China. Results based on a sample of 166 firms in Northern China confirm the positive influence of EO on performance. More importantly, the EO-performance relationship is more positive among state-owned enterprises (SOEs) than among privately-owned enterprises (POEs). Research and practical implications for EO in China are discussed.
LEARNING ABOUT WOMEN. ECONOMIC DEVELOPMENT, ENTREPRENEURSHIP AND THE ENVIRONMENT IN INDIA: A CASE STUDY
Authors: BERTAUX NANCY , CRABLE ELAINE
Published: January 2008

On a recent semester-long stay in India, students from Xavier University (Cincinnati, Ohio) learned about a variety of social and economic development issues, with an emphasis on the role and status of women. This study describes and assesses the impact and effectiveness of their learning with a particular focus on their exposure to Meerut Seva Samaj (MSS), one economic development initiative concentrating on rural women.

The Indian economy has recently witnessed an increase in entrepreneurship among women. Entrepreneurship often allows women to engage in home-based work so that they still can attend to their domestic duties, while also helping to financially support the family. Banks, companies, and NGOs (non-governmental organizations) are finding that offering micro-credit, or small loans, and other types of entrepreneurial assistance can help women start businesses. Meerut Seva Samaj provides a concrete example of how Indian women, especially in rural areas, can become successful entrepreneurs with the help of technology, training and other resources. MSS also assists local communities in the use of biogas, an environmentally friendly energy source that improves the environment and fertility of land in rural areas. The study places this service learning case study from India in the context of the literature on women, economic development, entrepreneurship and environmental issues.
Reversing Advanced Heart Failure by Targeting Ca2+Cycling
Authors: Kaye David M. , Hoshijima Masahiko , Chien Kenneth R.
Published: January 2008

Heart failure is a major cardiovascular disease, characterized by considerable morbidity and mortality. Despite major advances in the pharmacotherapy of heart failure, the options for patients with severe end-stage symptoms remain limited. However, recent developments in the identification of the molecular basis for the progressive nature of heart failure have identified a number of potentially important new therapeutic targets. In particular, key components of the cardiomyocyte calcium-handling pathway show characteristic changes in heart failure. A body of research examining the effect of restoration of these defects in experimental models of heart failure, whether in genetically engineered mouse models or by myocardial gene transfer, very strongly supports the calcium-handling pathway as a target for clinical intervention.
A Decade of Rituximab: Improving Survival Outcomes in Non-Hodgkin's Lymphoma
Authors: Molina Arturo
Published: January 2008

The anti-CD20 monoclonal antibody rituximab, first approved for clinical use in 1997, has changed the standard of care for many patients with non-Hodgkin's lymphoma (NHL). Recent data from large randomized clinical trials confirm that the addition of rituximab to standard chemotherapy regimens (chemoimmunotherapy) improves both response rates and survival outcomes in patients with follicular NHL and diffuse large B cell lymphoma (DLBCL), the two most common subtypes of NHL. Population-based analyses have found substantial improvements in NHL survival over the past decade; studies indicate that rituximab has favorably altered the long-term prognosis of follicular NHL and DLBCL patients. This review discusses the clinical development of rituximab-based therapies for patients with low-grade or follicular NHL and newly diagnosed DLBCL, highlighting recent key randomized trials with a focus on survival outcomes.
The Challenge of Hepatitis C in the HIV-Infected Person
Authors: Thomas David L.
Published: January 2008

Hepatitis C virus (HCV) coinfection occurs in an estimated one quarter of HIV-infected persons in Europe, Australia, and the United States. As use of highly active antiretroviral drugs has markedly reduced opportunistic infections, HCV-related liver disease has emerged as a leading cause of death. HIV infection adversely affects both the natural history and the treatment of hepatitis C. Because there are no experimental models of coinfection and because the pathogenesis of each infection is incompletely understood, how HIV infection alters hepatitis C is not clear. This review considers the epidemiology, natural history, treatment, and pathogenesis of hepatitis C in HIV-infected persons.
Insights into Zn2+ homeostasis in neurons from experimental and modeling studies
Authors: Colvin Robert A. , Bush Ashley I. , Volitakis Irene , Fontaine Charles P. , Thomas Dustin , Kikuchi Kazuya , Holmes William R.
Published: January 2008

To understand the mechanisms of neuronal Zn2+ homeostasis better, experimental data obtained from cultured cortical neurons were used to inform a series of increasingly complex computational models. Total metals (inductively coupled plasma-mass spectrometry), resting metallothionein, 65Zn2+ uptake and release, and intracellular free Zn2+ levels using ZnAF-2F were determined before and after neurons were exposed to increased Zn2+, either with or without the addition of a Zn2+ ionophore (pyrithione) or metal chelators [EDTA, clioquinol (CQ), and N, N, N′, N′-tetrakis(2-pyridylmethyl)ethylenediamine]. Three models were tested for the ability to match intracellular free Zn2+ transients and total Zn2+ content observed under these conditions. Only a model that incorporated a muffler with high affinity for Zn2+, trafficking Zn2+ to intracellular storage sites, was able to reproduce the experimental results, both qualitatively and quantitatively. This “muffler model” estimated the resting intracellular free Zn2+ concentration to be 1.07 nM. If metallothionein were to function as the exclusive cytosolic Zn2+ muffler, the muffler model predicts that the cellular concentration required to match experimental data is greater than the measured resting concentration of metallothionein. Thus Zn2+ buffering in resting cultured neurons requires additional high-affinity cytosolic metal binding moieties. Added CQ, as low as 1 μM, was shown to selectively increase Zn2+ influx. Simulations reproduced these data by modeling CQ as an ionophore. We conclude that maintenance of neuronal Zn2+ homeostasis, when challenged with Zn2+ loads, relies heavily on the function of a high-affinity muffler, the characteristics of which can be effectively studied with computational models.
Cholinergic stimulation induces asynchrony between the circular and longitudinal muscle contraction during esophageal peristalsis
Authors: Korsapati Hariprasad , Babaei Arash , Bhargava Valmik , Mittal Ravinder K.
Published: January 2008

In healthy subjects, a close temporal correlation exists between contractions of the circular muscle (CM) and longitudinal muscle (LM) layers of the esophagus. Patients with nutcracker esophagus show disassociation between the peak of contractions of the CM and LM layers and the peak of contraction 1–3 s apart (Jung HY, Puckett JL, Bhalla V, Rojas-Feria M, Bhargava V, Liu J, Mittal RK. Gastroenterology 128: 1179–1186, 2005). The purpose of the present study was to evaluate the effect of acetylcholinesterase inhibitor (edrophonium) and acetylcholine receptor antagonist (atropine) on human esophageal peristalsis in normal subjects. High-frequency intraluminal ultrasound imaging and manometry were performed simultaneously during swallow-induced peristalsis in ten normal subjects. Standardized 5-ml water swallows were recorded 2 cm above the lower esophageal sphincter under three study conditions: control, edrophonium (80 μg/kg iv), and atropine (10 μg/kg iv). A close temporal correlation exists between the peak pressure and peak wall thickness during the control period. The mean time lag between the peak LM and peak CM contraction was 0.03 s. After edrophonium administration, the mean contraction amplitude increased from 101 ± 9 mmHg to 150 ± 20 mmHg ( P < 0.05) and mean peak muscle thickness increased from 3.0 ± 0.2 mm to 3.6 ± 0.3 mm ( P < 0.01), and duration of both CM and LM contractions were also increased. Furthermore, the mean time difference between the peak LM and CM was increased to 1.1 s, (ranging 0.2 to 3.4 s) ( P < 0.0001). We conclude that cholinomimetic agent induces discoordination between the two muscle layers of the esophagus.
Regulation of ion transport by pH and [HCO3−] in isolated gills of the crabNeohelice(Chasmagnathus)granulata
Authors: Tresguerres Martin , Parks Scott K. , Sabatini Sebastian E. , Goss Greg G. , Luquet Carlos M.
Published: January 2008

Posterior isolated gills of Neohelice ( Chasmagnathus) granulatus were symmetrically perfused with hemolymph-like saline of varying [HCO3−] and pH. Elevating [HCO3−] in the saline from 2.5 to 12.5 mmol/l (pH 7.75 in both cases) induced a significant increase in the transepithelial potential difference ( Vte), a measure of ion transport. The elevation in [HCO3−] also induced a switch from acid secretion (−43.7 ± 22.5 μequiv·kg−1·h−1) in controls to base secretion (84.7 ± 14.4 μequiv·kg−1·h−1). The HCO3−-induced Vteincrease was inhibited by basolateral acetazolamide (200 μmol/l), amiloride (1 mmol/l), and ouabain (5 mmol/l) but not by bafilomycin (100 nmol/l). The Vteresponse to HCO3−did not take place in Cl−-free conditions; however, it was unaffected by apical SITS (2 mmol/l) or DIDS (1 mmol/l). A decrease in pH from 7.75 to 7.45 pH units in the perfusate also induced a significant increase in Vte, which was matched by a net increase in acid secretion of 67.8 ± 18.4 μequiv kg−1h−1. This stimulation was sensitive to basolateral acetazolamide, bafilomycin, DIDS, and Na+-free conditions, but it still took place in Cl−-free saline. Therefore, the cellular response to low pH is different from the HCO3−-stimulated response. We also report V-H+-ATPase- and Na+-K+-ATPase-like immunoreactivity in gill sections for the first time in this crab. Our results suggest that carbonic anhydrase (CA), basolateral Na+/H+exchangers and Na+-K+-ATPase and apical anion exchangers participate in the HCO3−-stimulated response, while CA, apical V-H+-ATPase and basolateral HCO3−-dependent cotransporters mediate the response to low pH.
Angiotensin-(1-7) serves as an aquaretic by increasing water intake and diuresis in association with downregulation of aquaporin-1 during pregnancy in rats
Authors: Joyner J. , Neves L. A. A. , Stovall K. , Ferrario C. M. , Brosnihan K. B.
Published: January 2008

We previously demonstrated that kidney and urine levels of angiotensin-(1-7) [ANG-(1-7)] were increased in pregnancy. To explore the role of ANG-(1-7) on fluid and electrolyte homeostasis during pregnancy, we evaluated the effect of the ANG-(1-7) antagonist d-alanine-[ANG-(1-7)] (A-779) on kidney function. Virgin and pregnant rats received infusion of vehicle or A-779 (48 μg·kg−1·h−1) for 8 days by osmotic minipumps. Metabolic studies were done on treatment day 7–8. Virgin and pregnant rats at day 15 and 19 were killed, and blood and kidneys were collected. Kidneys were prepared for Western blot analysis for aquaporin-1 (AQP1) and aquaporin-2. In virgin female rats, A-779 increased urine volume and decreased urinary osmolality and AQP1 with no change in water intake. In 19-day pregnant rats, A-779 significantly decreased water intake and urine volume and increased urinary osmolality and kidney AQP1 expression. Only in late gestation did A-779 treatment decrease the difference between intake and output (balance). A-779 treatment increased plasma vasopressin in late gestation but did not change vasopressin in virgins. In virgin and pregnant animals, A-779 administration had no effect on blood pressure, plasma volume, blood volume, or urinary electrolytes. These results suggest that ANG-(1-7) produces antidiuresis associated with upregulation of AQP1 in virgin rats, whereas ANG-(1-7) produces diuresis in late gestation with downregulation of AQP1. ANG-(1-7) contributes to the enhanced water intake during pregnancy, allowing maintenance of the normal volume-expanded state despite diuresis produced in part by decreased AVP and AQP1.
Effects of freshwater and saltwater adaptation and dietary salt on fluid compartments, blood pressure, and venous capacitance in trout
Authors: Olson Kenneth R. , Hoagland Todd M.
Published: January 2008

Trout are of interest in defining the relationship between fluid and salt balance on cardiovascular function because they thrive in freshwater (FW; volume loading, salt depleting), saltwater (SW; volume depleting, salt loading), and FW while fed a high-salt diet (FW-HS; volume and salt loading). The effects of chronic (>2 wk) adaptation to these three protocols on blood volume (51Cr red cell space), extracellular fluid volume (99mTc-diethylene triaminepenta-acetic acid space), arterial (dorsal aortic; PDA) and venous (ductus Cuvier; Pven) blood pressure, mean circulatory filling pressure (zero-flow Pven), and vascular capacitance were examined in the present study on unanesthetized rainbow trout. Blood volume, extracellular fluid volume, PDA, Pven, and mean circulatory filling pressure progressively increased in the order SW < FW < FW-HS. Vascular capacitance in SW fish appeared to be continuous with the capacitance curve of FW fish and reflect a passive volume-dependent unloading of the venous system of FW fish. Vascular capacitance curves for FW-HS fish were displaced upward and parallel to those of FW fish, indicative of an active increase in unstressed blood volume without any change in vascular compliance. These studies are the first in any vertebrate to measure the relationship between fluid compartments and cardiovascular function during independent manipulation of volume and salt balance, and they show that volume, but not salt, balance is the primary determinant of blood pressure in trout. They also present a new paradigm with which to investigate the relative contributions of water and salt balance in cardiovascular homeostasis.
Ezrin promotes functional expression and parathyroid hormone-mediated regulation of the sodium-phosphate cotransporter 2a in LLC-PK1 cells
Authors: Mahon Matthew J.
Published: January 2008

The sodium-phosphate cotransporter 2a (NPT2a) is the principal phosphate transporter expressed in the brush border of renal proximal tubules and is downregulated by parathyroid hormone (PTH) through an endocytic mechanism. Apical membrane expression of NPT2a is dependent on interactions with the sodium-hydrogen exchanger regulatory factor 1 (NHERF-1). An LLC-PK1 renal cell line stably expressing the PTH receptor (PTH1R) and NHERF-1, termed B28-N1, fails to functionally express NPT2a. In B28-N1 cells, NHERF-1 and NPT2a are inappropriately localized to the cytoplasm. Ezrin, in the activated state, is capable at linking NHERF-1-assembled complexes to the actin cytoskeleton. Early-passage LLC-PK1 cells stably transfected with either empty vector or wild-type ezrin express a comparable level of the active, T567 phosphorylated form of ezrin and are capable of functionally expressing NPT2a. Colocalization of the PTH1R, NPT2a, and ezrin exists and is prominently associated with actin-containing microvilli in apical domains of these cells. Upon PTH treatment, the PTH1R, NPT2a, NHERF-1, and ezrin colocalize to endocytic vesicles and NPT2a-dependent phosphate uptake is markedly inhibited. LLC-PK1 cells expressing the constitutively active ezrin (T567D) display enhanced NPT2a functional expression and PTH-mediated regulation of phosphate. Expression of a dominant-negative ezrin, consisting of the NH2-terminal half of the protein, markedly disrupts NPT2a-dependent phosphate uptake. PTH does not appear to alter ezrin phosphorylation at T567. Instead, PTH perhaps initiates NPT2a endocytosis by inducing reorganization of the actin-containing microvilli in a process that is blocked by the actin-stabilizing compound jasplakinolide.
Membrane current oscillations in descending vasa recta pericytes
Authors: Zhang Qingli , Cao Chunhua , Zhang Zhong , Wier W. Gil , Edwards Aurélie , Pallone Thomas L.
Published: January 2008

We investigated the origin of spontaneous transient inward current (STIC) oscillations in descending vasa recta (DVR) pericytes. In cells clamped at −80 mV, angiotensin II (ANG II; 10 nmol/l) induced oscillations with mean amplitude and frequency of −65.5 pA and 1.2 Hz. Simultaneous recording of cytoplasmic calcium ([Ca2+]CYT) and membrane current oscillations verified their synchrony and the correlation of their amplitudes. Confocal recording in fluo-4-loaded DVR showed that ANG II can induce either stable pericyte [Ca2+]CYTelevation or oscillations, while decreasing adjacent endothelial [Ca2+]CYT. Oscillating currents reversed sign at −30.2 mV and were blocked by niflumic acid, implicating charge transfer via Cl−ion. Removal of extracellular Ca2+, blockade of Ca2+influx with SKF96365 (30 μmol/l), ryanodine (30 μmol/l), or caffeine (10 mmol/l) inhibited oscillations. In contrast, they were insensitive to removal of extracellular Na+and exposure to either nifedipine (1 μmol/l) or 2-aminoethoxydiphenyl borate (10 μmol/l). Ouabain (100 nmol/l) increased basal pericyte [Ca2+]CYTand the frequency of resting STICs but did not affect the larger oscillations that followed ANG II stimulation. We conclude that [Ca2+]CYToscillations stimulate Cl−currents. The former are most likely maintained by repetitive cycles of ryanodine-sensitive SR Ca2+release and SKF96365 -sensitive store refilling.