bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frugal IV alternatives to identify the parameter for an endogenous regressor
Authors: Ebbes Peter , Wedel Michel , Böckenholt Ulf 
Published: March 2009

AbstractA review of the econometric literature on instrumental variables (IV) estimation shows that the performance of traditional IV estimation relies critically on the quality of the instruments. We discuss three different approaches that do not require the availability of observed instrumental variables: the ‘Higher Moments’ (HM) estimator, the ‘Identification trough Heteroscedasticity’ (IH) estimator, and the ‘Latent Instrumental Variable’ (LIV) approach. These methods attempt to identify the regression parameters not through observed instruments but by using other information that enables identifiability. The performance of these methods is illustrated on simulated and empirical data. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling category‐level purchase timing with brand‐level marketing variables
Authors: Fok Dennis , Paap Richard 
Published: March 2009

AbstractPurchase timing of households is usually modeled at the category level. However, many potential explanatory variables are observed at the brand level. To explain interpurchase times one has to either construct category‐level measures of marketing efforts, or integrate the model with a model for brand choice. In this paper we pursue the latter where we use latent brand preferences to capture the relevance of the marketing mix of an individual brand. We compare our new model with several standard approaches on in‐sample and out‐of‐sample fit and on the interpretation of the estimates of key parameters. Copyright © 2009 John Wiley & Sons, Ltd.
Towards a quantitative SERS approach – online monitoring of analytes in a microfluidic system with isotope‐edited internal standards
Authors: März Anne , Ackermann Katrin R. , Malsch Daniéll , Bocklitz Thomas , Henkel Thomas , Popp Jürgen 
Published: March 2009

AbstractIn this contribution a new approach for quantitative measurements using surface‐enhanced Raman spectroscopy (SERS) is presented. Combining the application of isotope‐edited internal standard with the advantages of the liquid–liquid segmented‐flow‐based approach for flow‐through SERS detection seems to be a promising means for quantitative SERS analysis.For the investigations discussed here a newly designed flow cell, tested for ideal mixing efficiency on the basis of grayscale‐value measurements, is implemented. Measurements with the heteroaromatics nicotine and pyridine using their respective deuterated isotopomers as internal standards show that the integration of an isotopically labeled internal standard in the used liquid–liquid two‐phase segmented flow leads to reproducible and comparable SERS spectra independent from the used colloid. With the implementation of an internal standard into the microfluidic device the influence of the properties of the colloid on the SERS activity can be compensated. Thus, the problem of a poor batch‐to‐batch reproducibility of the needed nanoparticle solutions is solved.To the best of our knowledge these are the first measurements combining the above mentioned concepts in order to correct for differences in the enhancement behaviour of the respective colloid. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Is it quinine TTP/HUS or quinine TMA? ADAMTS13 levels and implications for therapy
Authors: Park Yara A. , Hay Shauna N. , King Karen E. , Matevosyan Karen , Poisson Jessica , Powers Amy , Sarode Ravindra , Shaz Beth , Brecher Mark E. 
Published: March 2009

AbstractThrombocytopenia with or without microangiopathy following quinine is often referred to as quinine “hypersensitivity.” When schistocytes are present it is frequently termed “quinine‐associated TTP/HUS.” A severe deficiency of the vWF‐cleaving protease, ADAMTS13, is associated with idiopathic TTP. A previous study of patients with “quinine‐associated TTP/HUS” found that ADAMTS13 activities were not abnormal in 12/12 patients. A retrospective review of TTP patients with quinine‐associated thrombotic microangiopathy (TMA) for whom ADAMTS13 was measured before plasma exchange was performed. Six patients were identified. All were females (age range: 43 to 73, mean = 61.7 years) and had taken quinine for leg cramps. Four of the six experienced renal failure requiring dialysis. Five of the patients had D‐Dimers levels measured, all were elevated. In four patients the levels were ≥18 times the upper limit of normal. ADAMTS13 was normal in four patients and mildly decreased in two patients. We conclude that while thrombocytopenia and schistocytosis can be seen in quinine‐associated TTP/HUS, the pathophysiology seems to be distinct from that seen in most cases of idiopathic TTP (i.e., severely decreased ADAMTS13 with an inhibitor). We recommend that a TMA in association with quinine be consistently referred to as quinine‐associated thrombotic microangiopathy (quinine‐TMA) to better distinguish this entity from idiopathic TTP. The use of plasma exchange in quinine‐TMA is called into question. J. Clin. Apheresis, 2009. © 2009 Wiley‐Liss, Inc.
Synergy between anti‐CCL2 and docetaxel as determined by DW‐MRI in a metastatic bone cancer model
Authors: Rozel Stefan , Galbán Craig J. , Nicolay Klaas , Lee Kuei C. , Sud Sudha , Neeley Chris , Snyder Linda A. , Chenevert Thomas L. , Rehemtulla Alnawaz , Ross Brian D. , Pienta Kenneth J. 
Published: March 2009

AbstractMetastatic prostate cancer continues to be the second leading cause of cancer death in American men with an estimated 28,660 deaths in 2008. Recently, monocyte chemoattractant protein‐1 (MCP‐1, CCL2) has been identified as an important factor in the regulation of prostate metastasis. CCL2, shown to attract macrophages to the tumor site, has a direct promotional effect on tumor cell proliferation, migration, and survival. Previous studies have shown that anti‐CCL2 antibodies given in combination with docetaxel were able to induce tumor regression in a pre‐clinical prostate cancer model. A limitation for evaluating new treatments for metastatic prostate cancer to bone is the inability of imaging to objectively assess response to treatment. Diffusion‐weighted MRI (DW‐MRI) assesses response to anticancer therapies by quantifying the random (i.e., Brownian) motion of water molecules within the tumor mass, thus identifying cells undergoing apoptosis. We sought to measure the treatment response of prostate cancer in an osseous site to docetaxel, an anti‐CCL2 agent, and combination treatments using DW‐MRI. Measurements of tumor apparent diffusion coefficient (ADC) values were accomplished over time during a 14‐day treatment period and compared to response as measured by bioluminescence imaging and survival studies. The diffusion data provided early predictive evidence of the most effective therapy, with survival data results correlating with the DW‐MRI findings. DW‐MRI is under active investigation in the pre‐clinical and clinical settings to provide a sensitive and quantifiable means for early assessment of cancer treatment outcome. J. Cell. Biochem. 107: 58–64, 2009. © 2009 Wiley‐Liss, Inc.
GFP‐LC3 labels organised smooth endoplasmic reticulum membranes independently of autophagy
Authors: Korkhov Vladimir M. 
Published: March 2009

AbstractDisruption of autophagy leads to accumulation of intracellular multilamellar inclusions morphologically similar to organised smooth endoplasmic reticulum (OSER) membranes. However, the relation of these membranous compartments to autophagy is unknown. The purpose of this study was to test whether OSER plays a role in the autophagic protein degradation pathway. Here, GFP‐LC3 is shown to localise to the OSER membranes induced by calnexin expression both in transiently transfected HEK293 cells and in mouse embryo fibroblasts. In contrast to GFP‐LC3, endogenous LC3 is excluded from these membranes under normal conditions as well as after cell starvation. Furthermore, YFP‐Atg5, a protein essential for autophagy and known to reside on autophagic membranes, is excluded from the calnexin‐positive inclusion structures. In cells devoid of Atg5, a protein essential for autophagy and known to reside on autophagic membranes, colocalisation of calnexin with GFP‐LC3 within the multilamellar bodies is preserved. I show that calnexin, a protein enriched in the OSER, is not subject to autophagic or lysosomal degradation. Finally, GFP‐LC3 targeting to these membranes is independent of its processing and insensitive to drugs modulating autophagic and lysosomal protein degradation. These observations are inconsistent with a role of autophagic/lysosomal degradation in clearance of multilamellar bodies comprising OSER. Furthermore, GFP‐LC3, a fusion protein widely used as a marker for autophagic vesicles and pre‐autophagic compartments, may be trapped in this compartment and this artefact must be taken into account if the construct is used to visualise autophagic membranes. J. Cell. Biochem. 107: 86–95, 2009. © 2009 Wiley‐Liss, Inc.
Changes in contraction‐induced phosphorylation of AMP‐activated protein kinase and mitogen‐activated protein kinases in skeletal muscle after ovariectomy
Authors: Wohlers Lindsay M. , Sweeney Sean M. , Ward Christopher W. , Lovering Richard M. , Spangenburg Espen E. 
Published: March 2009

AbstractRecent evidence suggests that ovarian hormones contribute to altered function of skeletal muscle, however the signaling processes thought to regulate muscle function remain undefined in females. Thus, the purpose of this investigation is to determine if ovarian hormone status is critical for contraction‐induced activation of AMPK or MAPK in skeletal muscle. Female mice were divided into two groups, ovariectomy (OVX) and SHAM, which were then subjected to in situ isometric contractile protocols. AMPK, ERK 1/2, p38, and JNK phosphorylation were measured in the control and contracting limb. In the in situ protocol, OVX muscles were significantly more resistant to fatigue compared to the SHAM animals. In addition, the muscles from OVX mice demonstrated significantly lower levels of normalized AMPK phosphorylation at rest. AMPK phosphorylation was not increased in the muscles from SHAM mice after the in situ contractile protocol, while the OVX demonstrated significant increases in AMPK phosphorylation. After contraction, normalized ERK2 phosphorylation was significantly higher in the OVX group compared to the SHAM group. Both p38 and JNK phosphorylation increased in response to contraction; but no group differences were detected. A second set of SHAM and OVX animals were subjected to fatigue stimulated under in vitro conditions. Significant increases in AMPK and ERK2 phosphorylation were detected, but no differences were found between groups. In conclusion, removal of the ovaries results in different responses to contraction‐induced changes in phosphorylation of AMPK and ERK2 in female mice and suggests hormones secreted from the ovaries significantly impacts cellular signaling in skeletal muscle. J. Cell. Biochem. 107: 171–178, 2009. © 2009 Wiley‐Liss, Inc.
Testing the factor structure of a scale to assess african american acculturation: a confirmatory factor analysis
Authors: Reid Robert J. , Brown Tiffany L. , Andrew Peterson N. , Snowden Lonnie , Hines Alice 
Published: March 2009

AbstractResearch has pointed to the important role that acculturation plays in understanding a range of physical health behaviors as well as psychological functioning, but only a few studies have attempted to establish reliable and valid measures of African American acculturation. The scale developed by Snowden and Hines (1999) to assess African American acculturation provided an interesting line of inquiry for the present study because no further validation studies have been conducted to assess the underlying factor structure of this measure since its introduction several years ago. Confirmatory factor analysis techniques were used to test the measure's underlying structure and to determine consistency with the results of the original study. Results suggest that this scale represents multiple dimensions of acculturation (i.e., media preferences, social interaction patterns, and attitudes). Findings will assist researchers and practitioners in the future measurement and application of this construct. © 2009 Wiley Periodicals, Inc.
An examination of the role of perceptions in neighborhood research
Authors: Roosa Mark W. , White Rebecca M. B. , Zeiders Katharine H. , Tein Jenn‐Yun 
Published: March 2009

AbstractAccumulating research demonstrates that both archival indicators and residents' self‐reports of neighborhood conditions are useful predictors of a variety of physical health, mental health, substance use, criminal, and educational outcomes. Although studies have shown these two types of measures are often related, no research has systematically examined their relationship. With a sample of Mexican Americans, this study examined this relationship and demographic factors that might account for variations of residents' perceptions of their neighborhoods. Results showed that country of birth, social class, family structure, and gender moderated relations between archival variables and adults' perceptions of danger. Thus using information from both archival data and self‐reports should improve the ability of neighborhood researchers to understand individual differences in responses to neighborhood conditions. © 2009 Wiley Periodicals, Inc.
Development of a measure of sense of community for individuals with serious mental illness residing in community settings
Authors: Townley Greg , Kloos Bret 
Published: March 2009

AbstractThe psychological sense of community is one of the most commonly investigated constructs in community psychology. Sense of community may be particularly important for individuals with serious mental illness (SMI) because they often face societal barriers to participation in community living, including stigma and discrimination. To date, no published studies have investigated the psychometric qualities of sense of community measures among individuals with SMI. The current study tested a series of confirmatory factor analyses using the Brief Sense of Community Index (Long & Perkins, 2003) in a sample of 416 persons with SMI living in community settings to suggest a model of sense of community for individuals with SMI and other disabilities. The resulting scale, the Brief Sense of Community Index‐Disability, demonstrated good model fit and construct validity. Implications are discussed for how this scale may be used in research investigating community integration and adaptive functioning in community settings. © 2009 Wiley Periodicals, Inc.
Beyond survival: tracing individual empowerment processes in a poor chilean settlement
Authors: Turró Clàudia , Krause Mariane 
Published: March 2009

AbstractBased on the life histories of residents from La Victoria, a poor settlement in Santiago, Chile, this study reconstructed the central biographic elements in individual empowerment processes, linking them with the sociocultural context in which they occurred. Results show the following main characteristics related to individual empowerment: identification with struggle, coping with poverty, a positive attitude towards learning throughout life, a perception of meaning in life, the search for intimacy, and the desire to help others. The most empowering contextual elements found are the family models regarding work and the context that the La Victoria settlement offers its inhabitants as a protective space in which a sense of community and participation can develop. © 2009 Wiley Periodicals, Inc.
Molecular bases of myelodysplastic syndromes: Lessons from animal models
Authors: Komeno Yukiko , Kitaura Jiro , Kitamura Toshio 
Published: March 2009

AbstractMyelodysplastic syndrome (MDS) is a clonal disorder of hematopietic stem cells characterized by ineffective hematopoiesis, peripheral blood cytopenia, morphologic dysplasia, and susceptibility to acute myeloid leukemia. Several mechanisms have been suggested as causes of MDS: unbalanced chromosomal abnormalities reflecting a gain or loss of chromosomal material, point mutations of transcription factors, and inactivation of p53. However, appropriate animal models that mimic MDS have long been lacking. We recently reported a novel murine model of MDS that recapitulates trilineage dysplasia and transformation to AML. In this review, we summarize the animal models of MDS and discuss the molecular bases of MDS as well as those of leukemia and myeloproliferative disorders (MPD). J. Cell. Physiol. 219: 529–534, 2009. © 2009 Wiley‐Liss, Inc.
Hypoxia stimulates vesicular ATP release from rat osteoblasts
Authors: Orriss Isabel R. , Knight Gillian E. , Utting Jennifer C. , Taylor Sarah E.B. , Burnstock Geoffrey , Arnett Timothy R. 
Published: March 2009

AbstractMany neuronal and non‐neuronal cell types release ATP in a controlled manner. After release, extracellular ATP (or, following hydrolysis, ADP) acts on cells in a paracrine manner via P2 receptors. Extracellular nucleotides are now thought to play an important role in the regulation of bone cell function. ATP (and ADP), acting via the P2Y1receptor, stimulate osteoclast formation and activity, whilst P2Y2receptor stimulation by ATP (or UTP) inhibits bone mineralization by osteoblasts. We found that rat calvarial osteoblasts released ATP constitutively, in a differentiation‐dependent manner, with mature, bone‐forming osteoblasts releasing up to sevenfold more ATP than undifferentiated, proliferating cells. The inhibitors of vesicular exocytosis, monensin, andN‐ethylmaleimide (1–1,000 µM) inhibited basal ATP release by up to 99%. The presence of granular ATP‐filled vesicles within the osteoblast cytoplasm was demonstrated by quinacrine staining. Exposure to hypoxia (2% O2) for up to 3 min increased ATP release from osteoblasts up to 2.5‐fold without affecting cell viability. Peak concentrations of ATP released into culture medium were >1 µM, which equates with concentrations known to exert significant effects on osteoblast and osteoclast function. Monensin andN‐ethylmaleimide (100 µM) attenuated the hypoxia‐induced ATP release by up to 80%. Depletion of quinacrine‐stained vesicles was also apparent after hypoxic stimulation, indicating that ATP release had taken place. These data suggest that vesicular exocytosis is a key mediator of ATP release from osteoblasts, in biologically significant amounts. Moreover, increased extracellular ATP levels following acute exposure to low O2could influence local purinergic signaling and affect the balance between bone formation and bone resorption. J. Cell. Physiol. 220: 155–162, 2009. © 2009 Wiley‐Liss, Inc.
Endogenous IGFBP‐3 is required for both growth factor‐stimulated cell proliferation and cytokine‐induced apoptosis in mammary epithelial cells
Authors: Leibowitz Brian J. , Cohick Wendie S. 
Published: March 2009

AbstractTNF‐α and IGF‐I exert opposing effects on mammary epithelial cell (MEC) growth and survival. However, both increase IGF binding protein‐3 (IGFBP‐3) expression, a multifunctional protein that plays both IGF‐dependent as well as independent roles in these processes. We have reported that IGF‐I utilizes the PI3‐K and MAPK pathways to induce IGFBP‐3 expression in bovine MEC. Here we show that TNF‐α requires the SAPK pathway p38, but not JNK, to induce IGFBP‐3 expression. Contrary to reports in cancer cell lines, TNF‐α retained its ability to decrease DNA synthesis in cells transfected with IGFBP‐3 siRNA. It also retained its ability to inhibit IGF‐I‐stimulated DNA synthesis in these cells. In contrast, the ability of IGF‐I to increase DNA synthesis was attenuated with IGFBP‐3 knockdown. IGFBP‐3 knockdown also decreased basal DNA synthesis, indicating that a certain level of IGFBP‐3 may be required for cell proliferation. While TNF‐α alone failed to induce apoptosis, it increased cell death when added with the JNK agonist anisomycin (ANS). TNF‐α and ANS were unable to induce apoptosis when either IGFBP‐3 or JNK‐2 was knocked‐down, suggesting that both JNK and IGFBP‐3 may interact with a downstream molecule central to apoptosis. There are reports that IGFBP‐3 promotes either cell proliferation or apoptosis in different cell systems. However, this is the first report that endogenous IGFBP‐3 is required for the action of both stimulatory and inhibitory factors within the same cell line. Therefore, the actions of IGFBP‐3 are not pre‐determined, but instead governed by cellular context such as JNK activation. J. Cell. Physiol. 220: 182–188, 2009. © 2009 Wiley‐Liss, Inc.
Experimental evaluation of alkaline treatment as a method for enhancing the enzymatic digestibility of autohydrolysed Acacia dealbata
Authors: Yáñez Remedios , Romaní Aloia , Garrote Gil , Alonso José Luis , Parajó Juan Carlos 
Published: March 2009

AbstractBACKGROUND: Acacia dealbata wood samples were subjected to hydrothermal processing in aqueous media, yielding a liquid phase (containing xylooligosaccharides) and a solid phase, enriched in cellulose, which was treated with alkaline solutions to obtain solids with improved susceptibility towards enzymatic hydrolysis. The effects of the most influential variables involved in the alkaline processing (sodium hydroxide concentration, temperature and reaction time) on solid yield, solid composition and kinetic parameters involved in the modelling of the enzymatic hydrolysis were assessed using the response surface methodology (RSM).RESULTS: Analysis of the RSM equations allowed selection of operational conditions (temperature = 130 °C, sodium hydroxide concentration = 4.5%, time of alkaline processing = 3 h), leading to selective removal of non‐cellulosic components and to a solid substrate highly susceptible to enzymatic hydrolysis. Operating at an enzyme loading of 20 FPU (filter paper units) g−1 autohydrolysed, extracted solids (denoted AES) with a liquor to solid ratio of 30 g liquor g−1 AES, solutions containing 29.7 g glucose L−1 (corresponding to a yield of 47.3 g glucose per 100 g solids from autohydrolysis) were obtained after 48 h.CONCLUSION: Samples of Acacia dealbata wood were processed by autohydrolysis, sodium hydroxide treatment and enzymatic hydrolysis, yielding xylooligomers and processed solids highly susceptible to the enzymatic hydrolysis. Copyright © 2009 Society of Chemical Industry
Effect of feed composition on PHB production from methanol by HCDC of Methylobacterium extorquens (DSMZ 1340)
Authors: Mokhtari‐Hosseini Zahra Beagom , Vasheghani‐Farahani Ebrahim , Shojaosadati Seyed Abbas , Karimzadeh Ramin , Heidarzadeh‐Vazifekhoran Ali 
Published: March 2009

AbstractBACKGROUND: Poly‐β‐hydroxybutyrate (PHB), produced by several species of bacteria, has attracted great attention as a biodegradable and biocompatible compound with similar properties to polypropylene. Unfortunately, its use is currently limited due to high production costs. One of the most common methods for overcoming this constraint is the use of inexpensive substrates, like methanol, in high cell density cultivations (HCDC).RESULTS: Fermentation was carried out with optimized feed composition (639 g l−1 methanol, 4 g l−1 MgSO4.7H2O, 41 mL L−1 trace elements, 5.6 g L−1 NaH2PO4.H2O and 24.3 g L−1 K2HPO4) and a feeding strategy based on the detection of substrate limitation by dissolved oxygen (DO). After 35 h, at which dry cell weight (DCW) reached a value of 70 g L−1, PHB production was stimulated, and biomass and PHB productivities of 2.8 and 0.98 g L−1 h−1 were obtained, respectively. These results surpassed those reported in the literature for PHB production from methanol by Methylobacterium species.CONCLUSION: The proposed feed composition and feeding strategy for PHB production from methanol by Methylobacterium extorquens 1340 in fed‐batch cultivation resulted in high biomass and PHB productivity. They can be implemented for recombinant bioproducts (proteins) produced by M. extorquens due to the lack of PHB accumulation in the growth phase. Copyright © 2009 Society of Chemical Industry