bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forecast accuracy after pretesting with an application to the stock market
Authors: Danilov Dmitry , Magnus Jan R. 
Published: July 2004

AbstractIn econometrics, as a rule, the same data set is used to select the model and, conditional on the selected model, to forecast. However, one typically reports the properties of the (conditional) forecast, ignoring the fact that its properties are affected by the model selection (pretesting). This is wrong, and in this paper we show that the error can be substantial. We obtain explicit expressions for this error. To illustrate the theory we consider a regression approach to stock market forecasting, and show that the standard predictions ignoring pretesting are much less robust than naive econometrics might suggest. We also propose a forecast procedure based on the ‘neutral Laplace estimator’, which leads to an improvement over standard model selection procedures. Copyright © 2004 John Wiley & Sons, Ltd.
Forecasting the spot prices of various coffee types using linear and non‐linear error correction models
Authors: Milas Costas , Otero Jesús , Panagiotidis Theodore 
Published: July 2004

AbstractThis paper estimates linear and non‐linear error correction models for the spot prices of four different coffee types. In line with economic priors, we find some evidence that when prices are too high, they move back to equilibrium more slowly than when they are too low. This may reflect the fact that, in the short run, it is easier for countries to restrict the supply of coffee in order to raise prices, rather than increase supply in order to reduce them. Further, there is some evidence that adjustment is faster when deviations from the equilibrium level get larger. Our forecasting analysis suggests that asymmetric and polynomial error correction models offer weak evidence of improved forecasting performance relative to the random walk model. Copyright © 2004 John Wiley & Sons, Ltd.
The balance sheet channel of monetary policy: first empirical evidence for the euro area corporate bond market
Authors: de Bondt Gabe 
Published: July 2004

AbstractThe balance sheet channel of monetary policy working through the euro area corporate bond market is important, as shown by empirical results based on different methods for the first two and a half years since the introduction of the euro. The external finance premium on corporate bonds reflects, among other factors, monetary policy and leads real economic activity in the euro area. Copyright © 2004 John Wiley & Sons, Ltd.
Transforming growth factor‐β1‐dependent activation of Smad2/3 and up‐regulation of PAI‐1 expression is negatively regulated by Src in SKOV‐3 human ovarian cancer cells
Authors: Wakahara Kiyoshi , Kobayashi Hiroshi , Yagyu Tatsuo , Matsuzaki Hidenori , Kondo Toshiharu , Kurita Noriyuki , Sekino Hideo , Inagaki Kiyokazu , Suzuki Mika , Kanayama Naohiro , Terao Toshihiko 
Published: July 2004

AbstractThe net balance between urokinase‐type plasminogen activator (uPA) and plasminogen activator inhibitor type‐1 (PAI‐1) has been implicated in tumor cell invasion and metastasis. To elucidate the mechanism of the transforming growth factor‐β1 (TGF‐β1)‐dependent up‐regulation of PAI‐1 expression, we investigated which signaling pathway transduced by TGF‐β1 is responsible for this effect. Here, we show (1) nontoxic concentrations of TGF‐β1 up‐regulates uPA expression in HRA and SKOV‐3 human ovarian cancer cells, (2) TGF‐β1 activates Smads (phosphorylation of Smad2 and nuclear translocation of Smad3) and subsequently up‐regulates PAI‐1 expression in HRA cells, whereas TGF‐β1 neither activates Smads nor up‐regulates PAI‐1 in SKOV‐3 cells, (3) pharmacological Src inhibitor PP2 or antisense (AS) c‐Src oligodeoxynucleotide (ODN) treatment significantly induces TGF‐β1‐dependent activation of Smads, leading to PAI‐1 synthesis, compared with controls, in SKOV‐3 cells, (4) combination of TGF‐β1 and PP2, which activates PAI‐1 expression and reduces uPA expression in SKOV‐3, results in decreased invasiveness, (5) pharmacological inhibitors for mitogen‐activated protein kinase (MAPK) (PD98059) and phosphoinositide‐3‐kinase (PI3K) (LY294002 and wortmannin) or AS‐PI3K ODN transfection do not affect TGF‐β1‐induced Smad signaling and up‐regulation of PAI‐1 expression in SKOV‐3 cells pretreated with PP2, and (6) the induction of PAI‐1 protein was partially inhibited by an inhibitor of Sp1‐DNA binding, mithramycin, implicating, at least in part, Sp1 in the regulation of this gene by TGF‐β1. In conclusion, TGF‐β1‐dependent activation of Smad2/3, leading to PAI‐1 synthesis, may be negatively regulated by Src, but not its downstream targets MAPK and PI3K in SKOV‐3 cells. These data also reflect the complex biological effect of uPA‐PAI‐1 system. © 2004 Wiley‐Liss, Inc.
Inhibition of serum‐stimulated mitogen activated protein kinase by 1α,25(OH)2‐vitamin D3 in MCF‐7 breast cancer cells
Authors: Capiati Daniela A. , Rossi Ana M. , Picotto Gabriela , Benassati Silvia , Boland Ricardo L. 
Published: July 2004

Abstract1α,25‐Dihydroxyvitamin D3 [1α,25(OH)2D3], the hormonally active form of vitamin D3, has been shown to be a potent negative growth regulator of breast cancer cells both in vitro and in vivo. 1α,25(OH)2D3 acts through two different mechanisms. In addition to regulating gene transcription via its specific intracellular receptor (vitamin D receptor, VDR), 1α,25(OH)2D3 induces rapid, non‐transcriptional responses involving activation of transmembrane signal transduction pathways, like growth factors and peptide hormones. The mechanisms that mediate the antiproliferative effects of 1α,25(OH)2D3 in breast cancer cells are not fully understood. Particularly, there is no information about the early non‐genomic signal transduction effectors modulated by the hormone. The present study shows that 1α,25(OH)2D3 rapidly inhibits serum induced activation of ERK‐1 and ERK‐2 MAP kinases. The tyrosine kinase Src is involved in the pathway leading to activation of ERK 1/2 by serum. Furthermore, 1α,25(OH)2D3 increases the tyrosine‐phosphorylated state of Src and inhibits its kinase activity, while induces the association of the VDR with Src, either in the presence or absence of serum. In parallel, the hormone rapidly increases the amounts of VDR associated to plasma membranes (PM). Pretreatment with the tyrosine phosphatase inhibitors orthovanadate or bpV (phen) prevented mitogen‐activated protein kinase (MAPK) inhibition by 1α,25(OH)2D3. These data altogether suggest that 1α,25(OH)2D3 inhibits the MAPK cascade by inactivating Src tyrosine kinase through a mechanism mediated by the VDR and tyrosine phosphatases. © 2004 Wiley‐Liss, Inc.
Mutation of the highly conserved Arg165 and Glu168 residues of human Gsα disrupts the αD–αE loop and enhances basal GDP/GTP exchange rate
Authors: Hinrichs María Victoria , Montecino Martin , Bunster Marta , Olate Juan 
Published: July 2004

AbstractG protein signalling regulates a wide range of cellular processes such as motility, differentiation, secretion, neurotransmission, and cell division. G proteins consist of three subunits organized as a Gα monomer associated with a Gβγ heterodimer. Structural studies have shown that Gα subunits are constituted by two domains: a Ras‐like domain, also called the GTPase domain (GTPaseD), and an helical domain (HD), which is unique to heterotrimeric G‐proteins. The HD display significantly higher primary structure diversity than the GTPaseD. Regardless of this diversity, there are small regions of the HD which show high degree of identity with residues that are 100% conserved. One of such regions is the α helixD–α helixE loop (αD–αE) in the HD, which contains the consensus aminoacid sequence R*‐[RSA]‐[RSAN]‐E*‐[YF]‐[QH]‐L in all mammalian Gα subunits. Interestingly, the highly conserved arginine (R*) and glutamic acid (E*) residues form a salt bridge that stabilizes the αD–αE loop, that is localized in the top of the cleft formed between the GTPaseD and HD. Because the guanine nucleotide binding site is deeply buried in this cleft and those interdomain interactions are playing an important role in regulating the basal GDP/GTP nucleotide exchange rate of Gα subunits, we studied the role of these highly conserved R and E residues in Gα function. In the present study, we mutated the human Gsα R165 and E168 residues to alanine (A), thus generating the R165 → A, E168 → A, and R165/E168 → A mutants. We expressed these human Gsα (hGsα) mutants in bacteria as histidine tagged proteins, purified them by niquel‐agarose chromatography and studied their nucleotide exchange properties. We show that the double R165/E168 → A mutant exhibited a fivefold increased GTP binding kinetics, a higher GDP dissociation rate, and an augmented capacity to activate adenylyl cyclase. Structure analysis showed that disruption of the salt bridge between R165 and E168 by the introduced mutations, caused important structural changes in the HD at the αD–αE loop (residues 160–175) and in the GTPaseD at a region required for Gsα activation by the receptor (residues 308–315). In addition, other two GTPaseD regions that surround the GTP binding site were also affected. © 2004 Wiley‐Liss, Inc.
Study on the recognition of templates and their analogues on molecularly imprinted polymer using computational and conformational analysis approaches
Authors: Wu Liqing , Li Yuanzong 
Published: July 2004

AbstractA simplified computational model was proposed to simulate the synthesis of molecularly imprinted polymers (MIP), removal of template and recognition of the template and its analogues by MIP. The MIPs with nicotinamide and iso‐nicotinamide as templates were prepared using methacrylic acid as functional monomer. Based on our computational model, the interaction energies between the monomer and the template or its analogues were calculated, which were well correlated with the retention factors and imprinting factors obtained on HPLC columns packed with the corresponding MIP particles. The imprinting effects of the template and its analogues were also investigated from the viewpoint of conformational analysis. The computational data were successfully used to predict the chromatographic behaviour of some chemicals in separation on HPLC columns. We believe that the computational method will find application in designing monomers for MIP synthesis and in studying recognition of templates and their analogues on MIP. Copyright © 2004 John Wiley & Sons, Ltd.
Treatment of leg veins with the long pulse dye laser using variable pulse durations and energy fluences
Authors: Kono Taro , Yamaki Takashi , Erçöçen Ali Rıza , Fujiwara Osamu , Nozaki Motohiro 
Published: July 2004

AbstractBackground and ObjectivesAttempts at using the pulsed dye laser (PDL) operating at 585 nm wavelength and 0.45 milliseconds pulse duration to treat leg veins have been notably unsuccessful. The aim of this study is to evaluate the efficacy and complications of the 595 nm long PDL in the treatment of leg veins.Study Design/Patients and MethodsFourteen patients with 38 lesions were treated using a long PDL equipped with a cryogen spray cooling (CSC) device. Variable pulse durations ranging from 1.5 to 20 milliseconds and energy fluences from 10 to 20 J/cm2 were utilized depending on the size of treated vessels. All patients received two laser treatments at an interval of 2 months.ResultsOf patients with veins type 1A and type 1, 6 (100%) and 3 (13%) had complete clearing, respectively. Of patients with veins type 1 and type 2, 18 (78.3%) and 2 (22.2%) lesions showed excellent response, respectively. Hyperpigmentation was the only observed complication lasting several months in 57.9% of treated sites.ConclusionsThe long PDL operating at 595 nm is a safe and effective treatment for leg veins, especially in type 1A and type1 vessels. Lasers Surg. Med. 35:62–67, 2004. © 2004 Wiley‐Liss, Inc.
Long pulse Nd:YAG laser for treatment of leg veins in 40 patients with assessments at 6 and 12 months
Authors: Trelles Mario A. , Allones I. , Martín‐Vázquez M.J. , Trelles O. , Vélez M. , Mordon S. 
Published: July 2004

AbstractBackground and ObjectivesThis study assessed subjectively and objectively the efficacy of a long‐pulsed Nd:YAG laser system in clearing dermal leg veins, successful treatment of which remains problematic.Study Design/Patients and MethodsForty female patients (24–58 years old, skin types II–IV) with leg veins were treated with synchronized micropulses from a long‐pulsed 1,064 nm Nd:YAG laser, 6 mm diameter spot size, 130 and 140 J/cm2. One to three treatments were given at 6‐week intervals, with post‐treatment assessments at 6 and 12 months. Patients assessed improvement subjectively with a satisfaction index (SI). Objective assessment was based on the clinical photography, and in addition on computer‐generated data from a Canny operator‐based edge‐detection program.ResultsThe overall patient satisfaction rates and objective assessments at the 6 and 12 month assessments were 42.5 and 57.5%, and 75 and 82.5%, respectively.ConclusionsThe long‐pulsed Nd:YAG laser offered efficient treatment of leg veins. Side effects were minimal and transient. The edge‐detection program may help patients appreciate better the actual results of the treatment. Lasers Surg. Med. 35:68–76, 2004. © 2004 Wiley‐Liss, Inc.
On appropriate pathology for photothermal surgery
Authors: Shaco‐Levy Ruthy , Gordon Jeffrey M. , Feuermann Daniel , Huleihil Mahmoud , Mizrahi Solly 
Published: July 2004

AbstractBackground and ObjectivesThe standard hematoxylin and eosin (H&E) stain can yield dramatic underestimates of tissue death when pathology is performed immediately after radiative surgery. Our objectives were to identify an accurate, consistent histology, and to understand under what conditions the problem is manifested.Study Design/Materials and MethodsPhotothermal surgery with highly concentrated sunlight was performed ex vivo on chicken livers, and in vivo on healthy live rats that were sacrificed at periods of 0, 24, 48, and 72 hours. Pathology with both H&E and an alternative NADH‐diaphorase (NADH) stain were prepared.ResultsH&E pathology performed shortly after surgery errs by close to an order of magnitude in appraising lesion volume, but the shortfall is mitigated when histological examination is postponed for 24 hours. The biochemical signals missed by the H&E technique at short times can be captured by the NADH stain which reveals the cessation of enzymatic activity, albeit at greater expense and complexity.ConclusionsThe significance lies in avoiding false positives in surgery, providing reliable estimates of photothermal surgical efficacy, and highlighting the relative merits of alternative histological practices with photothermal surgery. Lasers Surg. Med. 35:28–34, 2004. © 2004 Wiley‐Liss, Inc.
CO2 laser resurfacing and photocarcinogenesis: An experimental study
Authors: Hedelund Lene , Haedersdal Merete , Egekvist Henrik , Heidenheim Michael , Wulf Hans Christian , Poulsen Thomas 
Published: July 2004

AbstractBackground and ObjectivesTo examine whether carbon dioxide (CO2) laser treatment has a carcinogenic potential or may influence ultraviolet (UV)‐induced carcinogenesis.Study Design/Materials and MethodsHairless mice (n = 211) were treated with a Sharplan CO2 laser with FeatherTouch scanner. Simulated solar irradiations were administrated either pre‐operatively or pre‐ and post‐operatively. Weekly clinical assessments of skin tumors were performed blinded during the entire observation period of 12 months.ResultsNo tumors appeared (a) in mice just treated with CO2 laser, (b) in mice exposed to UV irradiation only before CO2 laser treatment or (c) in untreated control mice. Tumors developed in CO2 laser treated mice that were exposed to UV‐irradiation both pre‐ and post‐operatively and in UV‐irradiated control mice. The time to first, second, and third tumors ranged from 18 to 20 weeks and no significant differences were demonstrated.ConclusionsCO2 laser treatment does not have a carcinogenic potential in itself, nor does CO2 laser treatment influence UV‐induced carcinogenesis. Lasers Surg. Med. 35:58–61, 2004. © 2004 Wiley‐Liss, Inc.
Thermal therapy of canine cerebral tumors using a 980 nm diode laser with MR temperature‐sensitive imaging feedback
Authors: Kangasniemi Marko , McNichols Roger J. , Bankson James A. , Gowda Ashok , Price Roger E. , Hazle John D. 
Published: July 2004

AbstractBackground and PurposeThe laser‐induced thermal therapy (LITT) of cerebral tumors has conventionally been performed using Nd:YAG lasers and is associated with a risk of high focal temperatures potentially followed by cavitation that could result in boiling and/or explosive char. We have developed small diffusing laser fiber tips to better distribute the energy deposition and a computer controlled feedback system to monitor therapy and prevent excess temperature buildup. In this study, we evaluated the feasibility of using magnetic resonance temperature imaging (MRTI)‐based feedback system for the thermal treatment of experimental intracerebral tumors using 980 nm laser irradiation delivered through these diffusing tips.Study Design/Materials and MethodsTransmissible venereal tumors (TVTs) were grown via inoculation in the right cerebral hemisphere of seven canines. The laser fiber tips were inserted into a total of 10 independent TVT‐suspected regions in the seven animals. Margins for the target area in each animal were prescribed on the basis of pretreatment MR images. MRTI‐based feedback software was used to measure and regulate both temperature and the delivered thermal dose to achieve the desired thermal ablation and prevent excess heating. The effects of treatment were verified by results of histologic analyses.ResultsTreatments resulted in contiguous areas of thermal necrosis in tumors and adjacent brain margin. The feedback software successfully cut off the laser power once the desired treatment volume was achieved, and prevented focal temperatures from exceeding predefined thresholds. Follow‐up MRI studies showed 1.4‐ to 2.9‐fold LITT‐induced lesion expansion within 1–6 days after treatment.ConclusionsTargeted thermal coagulation of small intracerebral tumors is feasible using MRTI‐based feedback and diffused 980 nm diode laser light. Lasers Surg. Med. 35:41–50, 2004. © 2004 Wiley‐Liss, Inc.
Closure of skin incisions in rabbits by laser soldering II: Tensile strength
Authors: Brosh Tamar , Simhon David , Halpern Marisa , Ravid Avi , Vasilyev Tamar , Kariv Naam , Nevo Zvi , Katzir Abraham 
Published: July 2004

AbstractBackground and ObjectivesThe basic characteristic property of wound closure is the immediate and long‐term tensile strength (LTS). The objective of the current study was to compare tissue laser soldering to other available methods (i.e., cyanoacrylate glues and sutures) in the performance and outcome of wound closure and reparative healing process, with an emphasis on the immediate and LTS.Study Design/Materials and MethodsThe animals were divided into three groups according to the type and details of the closure procedure. Group A: laser treatments at different temperatures were compared to sutured incisions, emphasizing the LTS after 10 days. Group B: laser soldering at 65 ± 5°C was compared to chemical glues (i.e., Histoacryl® and Dermabond®), emphasizing the immediate tensile strength (ITS). Group C: LTS of laser soldered incisions was compared to that of sutured incisions at various time intervals emphasizing LTS (3, 7, 14, 28 days).ResultsGroup A: LTS at 60°C exhibited the highest values (0.48 MPa). Group B: no ITS difference was detected between laser soldering and chemical glues. Group C: soldered incisions at 65°C exhibited higher LTS (1.81 MPa) than that of sutured incisions (1.08 MPa) (P < 0.043).ConclusionsTemperature‐controlled laser soldering at 65°C provided sufficient ITS and higher bonding LTS values compared with sutures, resulting in better wound healing characteristics. The laser soldering system presented here should be tested on larger animal models before adopting it for clinical usage. Lasers Surg. Med. 35:12–17, 2004. © 2004 Wiley‐Liss, Inc.
Assessing teratogenicity of antiretroviral drugs: monitoring and analysis plan of the Antiretroviral Pregnancy Registry
Authors: Covington Deborah L. , Tilson Hugh , Elder Jenna , Doi Peggy 
Published: July 2004

AbstractThis paper describes the Antiretroviral Pregnancy Registry's (APR) monitoring and analysis plan. APR is overseen by a committee of experts in obstetrics, pediatrics, teratology, infectious diseases, epidemiology and biostatistics from academia, government and the pharmaceutical industry. APR uses a prospective exposure‐registration cohort design. Clinicians voluntarily register pregnant women with prenatal exposures to any antiretroviral therapy and provide fetal/neonatal outcomes. A birth defect is any birth outcome ≥20 weeks gestation with a structural or chromosomal abnormality as determined by a geneticist. The prevalence is calculated by dividing the number of defects by the total number of live births and is compared to the prevalence in the CDC's population‐based surveillance system. Additionally, first trimester exposures, in which organogenesis occurs, are compared with second/third trimester exposures. Statistical inference is based on exact methods for binomial proportions. Overall, a cohort of 200 exposed newborns is required to detect a doubling of risk, with 80% power and a Type I error rate of 5%. APR uses the Rule of Three: immediate review occurs once three specific defects are reported for a specific exposure. The likelihood of finding three specific defects in a cohort of ≤600 by chance alone is less than 5% for all but the most common defects. To enhance the assurance of prompt, responsible, and appropriate action in the event of a potential signal, APR employs the strategy of ‘threshold’. The threshold for action is determined by the extent of certainty about the cases, driven by statistical considerations and tempered by the specifics of the cases. Copyright © 2004 John Wiley & Sons, Ltd.
Preparation and characterization of PBT nanocomposites compounded with different montmorillonites
Authors: Acierno Domenico , Scarfato Paola , Amendola Eugenio , Nocerino Giuseppe , Costa Giovanna 
Published: July 2004

AbstractBecause of their superior mechanical and thermal properties, light weight, and favorable cost/performance ratio, nanocomposite materials appear to be suitable replacements for metals and alloys in many industrial applications in fields such as automotive, structural plastics, electronics, packaging, and so on (1). The technological relevance of this large‐scale market for polymers is evidenced by the numerous patents issued over the last few years, even though only few applications have entered the market. Polymer‐clay nanocomposite systems were successfully prepared by melt compounding using several thermoplastic matrices (polyamides, polyolefins, etc.), but few data are reported in the scientific literature on polyester‐based nanocomposites (2). Because of the high commercial relevance of polyesters, we have investigated the effect of organoclay inclusion on the structure and properties of these hybrid systems. In particular, we have studied the relationships between processing conditions, hybrid composition (organoclay type and content), nanoscale morphology and properties of poly(butylene terephthalate) (PBT) nanocomposites based upon several commercial organo‐modified montmorillonites at different weight percentages. The melt compounding was performed using a twin‐screw extruder, at extrusion rates of 90 or 150 rpm. Polym. Eng. Sci. 44:1012–1018, 2004. © 2004 Society of Plastics Engineers.