bluuebunny/crossref_metadata_2025 huggingface dataset:
Composite Device for Attachment of Polyvinyl Alcohol‐hydrogel to Underlying Bone
Authors: Kobayashi Masanori , Oka Masanori
Published: July 2004

Abstract:  Polyvinyl alcohol‐hydrogels (PVA‐H) have been specifically proposed as promising prosthetic biomaterials because of their excellent mechanical properties and biocompatibility. However, it is very difficult to obtain stable long‐term fixation of implanted PVA‐H and this problem is the key point to be solved in the further development of PVA‐H in biomedical applications more widely in various fields. Orthopedic implants using PVA‐H have been developed and in the process this problem was solved using a composite device. This device consists of PVA‐H and a titanium fiber mesh (TFM) as a porous tissue‐ingrowth material. In the present study, the mechanical properties of this composite device produced using a new improved production method (injection molding) were investigated and animal experiments for in vivo evaluation were performed. In vitro tests showed that the shear strength at the interface of  the  PVA‐H  and  TFM,  and  the  mechanical  properties of  PVA‐H itself were promising. Moreover, the histological appearance of the composite device implant in vivo showed abundant bone ingrowth into the deep pore spaces of TFM, which indicated that this device attached firmly to the adjacent bone. These results indicated this composite device prepared by this new method can supply firm attachment of PVA‐H onto underlying bone, and that it will be available for various biomedical applications using PVA‐H.
Information and the Cost of Capital
Authors: Easley David , O'hara Maureen
Published: July 2004

We investigate the role of information in affecting a firm's cost of capital. We show that differences in the composition of information between public and private information affect the cost of capital, with investors demanding a higher return to hold stocks with greater private information. This higher return arises because informed investors are better able to shift their portfolio to incorporate new information, and uninformed investors are thus disadvantaged. In equilibrium, the quantity and quality of information affect asset prices. We show firms can influence their cost of capital by choosing features like accounting treatments, analyst coverage, and market microstructure.
Diversification as a Public Good: Community Effects in Portfolio Choice
Authors: Demarzo Peter M. , Kaniel Ron , Kremer Ilan
Published: July 2004

Within a rational general equilibrium model in which agents care only about personal consumption, we consider a setting in which, due to borrowing constraints, individuals endowed with local resources underparticipate in financial markets. As a result, investors compete for local resources through their portfolio choices. Even with complete financial markets and no aggregate risk, agents may herd into risky portfolios. This yields a Pareto‐dominated outcome as agents introduce “community” risk unrelated to fundamentals. Moreover, if some agents are behaviorally biased, or cannot completely diversify their holdings, rational agents may choose more extreme portfolios and amplify the effect.
Tobin's Q, Debt Overhang, and Investment
Authors: Hennessy Christopher A.
Published: July 2004

Incorporating debt in a dynamic real options framework, we show that underinvestment stems from truncation of equity's horizon at default. Debt overhang distorts both the level and composition of investment, with underinvestment being more severe for long‐lived assets. An empirical proxy for the shadow price of capital to equity is derived. Use of this proxy yields a structural test for debt overhang and its mitigation through issuance of additional secured debt. Using measurement error‐consistent GMM estimators, we find a statistically significant debt overhang effect regardless of firms' ability to issue additional secured debt.
What Do Entrepreneurs Pay for Venture Capital Affiliation?
Authors: Hsu David H.
Published: July 2004

This study empirically evaluates the certification and value‐added roles of reputable venture capitalists (VCs). Using a novel sample of entrepreneurial start‐ups with multiple financing offers, I analyze financing offers made by competing VCs at the first professional round of start‐up funding, holding characteristics of the start‐up fixed. Offers made by VCs with a high reputation are three times more likely to be accepted, and high‐reputation VCs acquire start‐up equity at a 10–14% discount. The evidence suggests that VCs' “extra‐financial” value may be more distinctive than their functionally equivalent financial capital. These extra‐financial services can have financial consequences.
Short‐Selling Prior to Earnings Announcements
Authors: Christophe Stephen E. , Ferri Michael G. , Angel James J.
Published: July 2004

This paper examines short‐sales transactions in the five days prior to earnings announcements of 913 Nasdaq‐listed firms. The tests provide evidence of informed trading in pre‐announcement short‐selling because they reveal that abnormal short‐selling is significantly linked to post‐announcement stock returns. Also, the tests indicate that short‐sellers typically are more active in stocks with low book‐to‐market valuations or low SUEs. The levels of pre‐announcement short‐selling, however, mostly appear to reflect firm‐specific information rather than these fundamental financial characteristics. We believe that these results should encourage financial market regulators to consider providing more extensive and timely disclosures of short‐selling to investors.
Electricity Forward Prices: A High‐Frequency Empirical Analysis
Authors: Longstaff Francis A. , Wang Ashley W.
Published: July 2004

We conduct an empirical analysis of forward prices in the PJM electricity market using a high‐frequency data set of hourly spot and day‐ahead forward prices. We find that there are significant risk premia in electricity forward prices. These premia vary systematically throughout the day and are directly related to economic risk factors, such as the volatility of unexpected changes in demand, spot prices, and total revenues. These results support the hypothesis that electricity forward prices in the Pennsylvania, New Jersey, and Maryland market are determined rationally by risk‐averse economic agents.
Excessive Increase in QT Interval and Dispersion of Repolarization Predict Recurrent Ventricular Tachyarrhythmia after Amiodarone
Authors: AIBA TAKESHI , SHIMIZU WATARU , INAGAKI MASASHI , SATOMI KAZUHIRO , TAGUCHI ATSUSHI , KURITA TAKASHI , SUYAMA KAZUHIRO , AIHARA NAOHIKO , SUNAGAWA KENJI , KAMAKURA SHIRO
Published: July 2004

Although chronic amiodarone has been proven to be effective to suppress ventricular tachycardia (VT) and ventricular fibrillation (VF), how we predict the recurrence of VT/VF after chronic amiodarone remains unknown. This study evaluated the predictive value of the QT interval, spatial, and transmural dispersions of repolarization (SDR and TDR) for further arrhythmic events after chronic amiodarone. Eighty‐seven leads body surface ECGs were recorded before (pre) and one month after (post) chronic oral amiodarone in 50 patients with sustained monomorphic VT associated with organic heart disease. The Q‐Tend (QTe), the Q‐Tpeak (QTp), and the interval between Tpeak and Tend (Tp‐e) as an index of TDR were measured automatically from 87‐lead ECG, corrected Bazett's method (QTce, QTcp, Tcp‐e), and averaged among all 87 leads. As an index of SDR, the maximum (max) minus minimum (min) QTce (max‐min QTce) and standard deviation of QTce (SD‐QTce) was obtained among 87 leads. All patients were prospectively followed (15 ± 10 months) after starting amiodarone, and 20 patients had arrhythmic events. The univariate analysis revealed that post max QTce, post SD‐QTce, post max‐min QTce, and post mean Tcp‐e from 87‐lead but not from 12‐lead ECG were the significant predictors for further arrhythmic events. ROC analysis indicated the post max‐min QTce ≥106 ms as the best predictor of events (hazard ratio = 10.4, 95%, CI 2.7 to 40.5, P = 0.0008). Excessive QT prolongation associated with increased spatial and transmural dispersions of repolarization predict the recurrence of VT/VF after amiodarone treatment. (PACE 2004; 27:901–909)
Situational Syncope:
Authors: LIVANIS EFTHIMIOS G. , LEFTHERIOTIS DIONYSSIOS , THEODORAKIS GEORGE N. , FLEVARI PANAGIOTA , ZARVALIS ELIAS , KOLOKATHIS FOTIS , KREMASTINOS DIMITRIOS TH.
Published: July 2004

Among sequential patients with neurally‐mediated syncope, we studied the response to head‐up tilt test (HUTT) in patients with situational syncope (SS) and their follow‐up. Our findings were compared to those in patients with vasovagal syncope (VVS). The response to HUTT in patients with SS has not to date been fully investigated. Additionally, the prognosis of SS patients has not been systematically studied. We studied 162 consecutive patients with recurrent SS or VVS, all free of structural heart disease. Before study inclusion, they underwent an HUTT and were followed up for 12 months. Patients with SS were advised to avoid the trigger event. Patients with VVS were treated with propranolol or fluoxetine. For each patient we compared the number of syncopal spells during the last 12 months before study inclusion with that during follow‐up. Among the 162 patients, 36 had SS and 126 had VVS. The response to HUTT and the number of syncopes before and during follow‐up were similar in both groups. Among patients with SS, 10 (28%) had also experienced occasional episodes of VVS; however, they had a similar response to HUTT and prognosis to the remaining 26 SS patients without VVS attacks. Patients with SS have a similar response to HUTT and similarly benign clinical course to patients with VVS. The coexistence of occasional VVS episodes in patients with SS is not associated with a higher rate of positive HUTT or worse prognosis. (PACE 2004; 27:918–923)
Endocardial Atrial Pacing Lead Implantation and Midterm Follow‐Up in Young Patients with Sinus Node Dysfunction After the Fontan Procedure
Authors: SHAH MAULLY J. , NEHGME RODRIGO , CARBONI MICHAEL , MURPHY JOHN D.
Published: July 2004

The purpose of the study was to investigate the results of endocardial lead implantation, lead performance, and follow‐up in young patients after the Fontan procedure. A retrospective study was conducted with patients who had endocardial atrial pacing for SND and intact AVN function after Fontan from two pediatric centers. Patient demographics, pacing, and sensing data of endocardial atrial leads were analyzed at the time of pacemaker implantation and follow‐up visits. Fifteen patients (weight 42.6 ± 35 kg) had transvenous endocardial atrial lead implantation at an average age of 11.4 ± 6.5 years. Active‐fixation leads were used in all patients and steroid elution was present in 12 (80%) patients. Adequate P wave sensing was obtained in patients with sinus rhythm (n = 10); the remaining four patients had junctional rhythm without measurable P waves. Lead failure was not observed in any patient during the follow‐up period of 2.9 ± 2.1 years. The energy threshold at implantation was 1.46 ± 1.5 μJ, 1.54 ± 0.75 μJ at 3 months, 0.62 ± 0.45 μJ at 1 year, 0.72 ± 0.65 μJ at 2 years, 0.75 ± 0.55 μJ at 3 years, and 0.8 ± 0.85 μJ at 5 years postimplant. The lead impedance was 648 ± 298 Ω at implantation, 714 ± 163 Ω at 3 months, 744 ± 195 Ω at 1 year, 734 ± 198 Ω at 2 years, 800 ± 142 Ω at 3 years and 830 ± 200 Ω 5 years postimplant. Anticoagulation therapy (aspirin n = 5, warfarin n = 8) was continued by 13 patients. Complications consisted of a pneumothorax at implantation and a transient ischemic attack in one patient 4 years after pacemaker implant. Endocardial atrial leads offer low energy thresholds and can be implanted relatively safely in Fontan patients. (PACE 2004; 27:949–954)
Accuracy of Atrial Tachyarrhythmia Detection in Implantable Devices with Arrhythmia Therapies
Authors: PURERFELLNER HELMUT , GILLIS ANNE M. , HOLBROOK REECE , HETTRICK DOUGLAS A.
Published: July 2004

The clinical application of atrial tachyarrhythmia (AT) episode data stored by implantable devices is presently limited by the high proportion of inappropriate detection. We quantified the percentage of inappropriate AT detection in two implantable devices with AT diagnostics and therapies via meta‐analysis of stored AT episodes from a number of clinical trials. The AT500 and GEM III AT, contain dual chamber logic to discriminate AT from ventricular tachycardia and far‐field R wave (FFRW) oversensing using dual chamber bipolar electrograms. A subset of data from four clinical trials of 1,142 patients was considered. Manual analysis was performed on 21,553 stored episodes with atrial EGM and marker channel from 409 patients with stored episodes and the market‐released device detection configuration. The percentage of episodes with inappropriate detection and termination was evaluated and compared between septal and nonseptal lead locations. The percentage of inappropriately detected episodes receiving ATP therapy was also determined. The percentage of episodes appropriately detected and the percentage of net episode duration (i.e., burden) recorded by the device were also determined from a separate analysis of 24‐hour Holter recordings from a subset of 40 patients from one trial. Adjusted estimates of the percentage of inappropriate detection were 95.3% (93.5–96.7; 95% CI) for AT500 and 95.7% (84.3–98.9) for GEM III AT. Inappropriate detection was primarily due to FFRW oversensing or brief runs of premature atrial contractions (PACs). The device detected 100% of the sustained atrial arrhythmia episodes and 95.3% (range 76.1–99.9) of the net AT duration observed on the Holter recordings. AT detection was not influenced by atrial lead location. Appropriate detection of normal sinus rhythm at episode termination was 83.7% (80.7–86.3) for AT500 and 92.1% (84.5–96.2) for GEM III AT. Accurate detection and discrimination of FFRWs validates the reliability of AT diagnostic data and decreases the risk of inappropriate device therapy. (PACE 2004; 27:983–992)
Complete Loss of ICD Programmability After Magnetic Resonance Imaging
Authors: FIEK MICHAEL , REMP THOMAS , REITHMANN CHRISTOPHER , STEINBECK GERHARD
Published: July 2004

The purpose of this case report is to describe the effects of an MRI performed on a patient without realizing that an ICD has been previously implanted. After a few seconds of imaging the adversity was recognized and the examination was stopped immediately. The patient was not pacemaker dependent and had neither physical complaints nor electrocardiographic changes in the surface ECG. A consecutively performed ICD assessment showed a backup mode with standard parameters for pacing (VVI 50 beats/min) and arrhythmia detection and treatment. The device could not be programmed by the external programmer. With the exception of printing out the parameters, all software functions were no longer feasible. A device examination by the manufacturer after ICD replacement showed that a major portion of the device memory was corrupt. Even ICDs of a newer generation are susceptible to magnetic interference, with the danger of complete loss of programmability. (PACE 2004; 27:1002–1004)
Welfare Reform and Economic and Housing Capacity for Low‐Income Households, 1997–1999
Authors: Robbins Suzanne M. , Barcus Holly R.
Published: July 2004

The 1996 Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) marked the continued devolution of social policy to state and local government in addition to restructuring an ailing welfare system. Despite concerns that welfare recipients would find greater obstacles to economic stability as a result, declining welfare rolls have been accompanied by declining poverty rates over the past seven years. An important question is whether low‐income families have gained greater employment and housing capacity following welfare reform. Moreover, does capacity vary across states with different welfare policies? In addition, do families face greater economic vulnerability with respect to food scarcity and health care? This article uses the data from the 1997 and 1999 waves of the National Survey of America's Families to systematically assess differences in capacity and vulnerability among lower income families across different policy regimes. Using two measures of capacity for housing and employment, and quality of life, findings suggest that more stringent welfare rules are related to greater job and housing attainment but a reduced quality of life.
Values in clinical nursing practice and caring
Authors: GREGG Misuzu F. , MAGILVY Joan K.
Published: July 2004

Aim: The aims of this study were to describe nurses’ values in clinical nursing practice and to identify how caring exists in their practice, based on the description of values. In this paper, the definition of caring was adopted from the theory of human caring, where caring is depicted as the moral ideal of nursing.

Methods: Data were generated by participant observations from 24 nurses, semistructured formal interviews with seven nurses, and informal interviews. The nurses were associated with an internal medicine ward within an acute hospital in Japan. Data were analysed by using a qualitative descriptive method.

Results: Twelve categories emerged from the data analysis: considering a patient's feelings, having nursing knowledge and skills, advocating for their patients, having a relationship as a human being, being with a patient, touching a patient, listening to a patient, making a difference, helping each other as nurses, being connected to a patient, denoting the ‘meaning of one's life’, and realizing nursing as a means of self‐actualization. These categories were illustrated as a schematic model of values in clinical nursing practice.

Conclusions: This study described nurses’ values in clinical nursing practice. The results showed that there was evidence of caring in daily Japanese clinical nursing practice, even within a strong medical model acute hospital.
A randomized controlled trial of a group care program for community‐dwelling elderly people with dementia
Authors: TADAKA Etsuko , KANAGAWA Katsuko
Published: July 2004

Aim:  To examine the effectiveness of a group care program consisting of reminiscence and reality orientation care methods to prevent the decline of cognitive and daily activity function in community‐dwelling elderly persons with dementia in a randomized controlled trial with a 6‐month follow‐up period.

Methods:  Sixty community‐dwelling elderly persons with dementia were randomly assigned to either an intervention or a control group. The intervention group followed the group care program consisting of reminiscence and reality orientation care methods in addition to a routine day‐care service once a week for 10 consecutive weeks; the control group followed only a routine day‐care service in the same institution as the intervention group for the same study period.

Results:  On cognitive function, the intervention group exhibited a significant effect compared with the control group immediately after the intervention (P < 0.05), but no significant effect was observed after 6 months. On daily activity function, the intervention group exhibited significant effects compared with the control group in disorientation and withdrawal immediately after the intervention (P < 0.05) and after 6 months (P < 0.05).

Conclusions:  The group care program consisting of reminiscence and reality orientation care methods can be effective for the improvement of cognitive function in the short‐term and on the improvement of disorientation and withdrawal in the long‐term. It is suggested, however, that sustained intervention may be necessary to maintain the effect over time.
A Synthetic Conjugate Polysaccharide Vaccine Against
Haemophilus influenzae
Type b
Authors: Verez-Bencomo V. , Fernández-Santana V. , Hardy Eugenio , Toledo Maria E. , Rodríguez Maria C. , Heynngnezz Lazaro , Rodriguez Arlene , Baly Alberto , Herrera Luis , Izquierdo Mabel , Villar Annette , Valdés Yury , Cosme Karelia , Deler Mercedes L. , Montane Manuel , Garcia Ernesto , Ramos Alexis , Aguilar Aristides , Medina Ernesto , Toraño Gilda , Sosa Iván , Hernandez Ibis , Martínez Raydel , Muzachio Alexis , Carmenates Ania , Costa Lourdes , Cardoso Félix , Campa Concepción , Diaz Manuel , Roy René
Published: July 2004

Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of
Haemophilus influenzae
type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate–based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.
Public Information: From Nosy Neighbors to Cultural Evolution
Authors: Danchin Étienne , Giraldeau Luc-Alain , Valone Thomas J. , Wagner Richard H.
Published: July 2004

Psychologists, economists, and advertising moguls have long known that human decision-making is strongly influenced by the behavior of others. A rapidly accumulating body of evidence suggests that the same is true in animals. Individuals can use information arising from cues inadvertently produced by the behavior of other individuals with similar requirements. Many of these cues provide public information about the quality of alternatives. The use of public information is taxonomically widespread and can enhance fitness. Public information can lead to cultural evolution, which we suggest may then affect biological evolution.
Comet or Asteroid Shower in the Late Eocene?
Authors: Tagle Roald , Claeys Philippe
Published: July 2004

The passage of a comet shower ~35 million years ago is generally advocated to explain the coincidence during Earth's late Eocene of an unusually high flux of interplanetary dust particles and the formation of the two largest craters in the Cenozoic, Popigai and the Chesapeake Bay. However, new platinum-group element analyses indicate that Popigai was formed by the impact of an L-chondrite meteorite. Such an asteroidal projectile is difficult to reconcile with a cometary origin. Perhaps instead the higher delivery rate of extraterrestrial matter, dust, and large objects was caused by a major collision in the asteroid belt.
Functional Adaptation of BabA, the
H. pylori
ABO Blood Group Antigen Binding Adhesin
Authors: Aspholm-Hurtig Marina , Dailide Giedrius , Lahmann Martina , Kalia Awdhesh , Ilver Dag , Roche Niamh , Vikström Susanne , Sjöström Rolf , Lindén Sara , Bäckström Anna , Lundberg Carina , Arnqvist Anna , Mahdavi Jafar , Nilsson Ulf J. , Velapatiño Billie , Gilman Robert H. , Gerhard Markus , Alarcon Teresa , López-Brea Manuel , Nakazawa Teruko , Fox James G. , Correa Pelayo , Dominguez-Bello Maria Gloria , Perez-Perez Guillermo I. , Blaser Martin J. , Normark Staffan , Carlstedt Ingemar , Oscarson Stefan , Teneberg Susann , Berg Douglas E. , Borén Thomas
Published: July 2004

Adherence by
Helicobacter pylori
increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in
babA
sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to
babA
diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O–dominant human populations.
Phosphorylation by Cyclin B-Cdk Underlies Release of Mitotic Exit Activator Cdc14 from the Nucleolus
Authors: Azzam Ramzi , Chen Susan L. , Shou Wenying , Mah Angie S. , Alexandru Gabriela , Nasmyth Kim , Annan Roland S. , Carr Steven A. , Deshaies Raymond J.
Published: July 2004

Budding yeast protein phosphatase Cdc14 is sequestered in the nucleolus in an inactive state during interphase by the anchor protein Net1. Upon entry into anaphase, the Cdc14 early anaphase release (FEAR) network initiates dispersal of active Cdc14 throughout the cell. We report that the FEARnetwork promotes phosphorylation of Net1 by cyclin-dependent kinase (Cdk) complexed with cyclin B1 or cyclin B2. These phosphorylations appear to be required for FEAR and sustain the proper timing of late mitotic events. Thus, a regulatory circuit exists to ensure that the arbiter of the mitotic state, Cdk, sets in motion events that culminate in exit from mitosis.
A Model Population of Large Herbivores
Authors: Stenseth Nils Chr.
Published: July 2004

Soay Sheep
Dynamics and Selection in an Island Population. Tim Clutton-Brock and Josephine Pemberton, Eds. Cambridge University Press, Cambridge, 2004. 395 pp. $120, £80. ISBN 0-521-82300-5. Paper, $50, £33. ISBN 0-521-52990-5.

The contributors offer a synthesis of nearly 50 years of research on a classic model system for population biology, the Soay sheep of Hirta.
Quantitative Gene Expression Profiling Implicates Genes for Susceptibility and Resistance to Alveolar Bone Loss
Authors: Hart G. T. , Shaffer D. J. , Akilesh S. , Brown A. C. , Moran L. , Roopenian D. C. , Baker P. J.
Published: July 2004

Periodontal disease is one of the most prevalent chronic inflammatory diseases. There is a genetic component to susceptibility and resistance to this disease. Using a mouse model, we investigated the progression of alveolar bone loss by gene expression profiling of susceptible and resistant mouse strains (BALB/cByJ and A/J, respectively). We employed a novel and sensitive quantitative real-time PCR method to compare basal RNA transcription of a 48-gene set in the gingiva and the spleen and the subsequent changes in gene expression due toPorphyromonas gingivalisoral infection. Basal expression of interleukin-1 beta (Il1b) and tumor necrosis factor alpha (Tnf) mRNA was higher in the gingiva of the susceptible BALB/cByJ mice than in the gingiva of resistant A/J mice. GingivalIl1bgene expression increased further andStat6gene expression was turned on afterP. gingivalisinfection in BALB/cByJ mice but not in A/J mice. The basal expression of interleukin-15 (Il15) in the gingiva and the basal expression of p-selectin (Selp) in the spleen were higher in the resistant A/J mice than in the susceptible BALB/cByJ mice. In the resistant A/J mice the expression of no genes detectably changed in the gingiva after infection. These results suggest a molecular phenotype in which discrete sets of differentially expressed genes are associated with genetically determined susceptibility (Il1b,Tnf, andStat6) or resistance (Il15andSelp) to alveolar bone loss, providing insight into the genetic etiology of this complex disease.
Immunostimulatory CpG Oligodeoxynucleotide Confers Protection in a Murine Model of Infection withBurkholderia pseudomallei
Authors: Wongratanacheewin Surasakdi , Kespichayawattana Wannapa , Intachote Pakamas , Pichyangkul Sathit , Sermswan Rasana W. , Krieg Arthur M. , Sirisinha Stitaya
Published: July 2004

Although CpG oligodeoxynucleotides (CpG ODNs) are known to enhance resistance against infection in a number of animal models, little is known about the CpG-induced protection against acute fatal sepsis such as that associated with the highly virulent bacteriumBurkholderia pseudomallei. We previously demonstrated in an in vitro study that immunostimulatory CpG ODN 1826 enhances phagocytosis ofB. pseudomalleiand induces nitric oxide synthase and nitric oxide production by mouse macrophages. In the present study, CpG ODN 1826 given intramuscularly to BALB/c mice 2 to 10 days prior toB. pseudomalleichallenge conferred better than 90% protection. CpG ODN 1826 given 2 days before the bacterial challenge rapidly enhanced the innate immunity of these animals, judging from the elevated serum levels of interleukin-12 (IL-12)p70 and gamma interferon (IFN-γ) over the baseline values. No bacteremia was detected on day 2 in 85 to 90% of the CpG-treated animals, whereas more than 80% of the untreated animals exhibited heavy bacterial loads. Although marked elevation of IFN-γ was found consistently in the infected animals 2 days after the bacterial challenge, it was ameliorated by the CpG ODN 1826 pretreatment (P= 0.0002). Taken together, the kinetics of bacteremia and cytokine profiles presented are compatible with the possibility that protection by CpG ODN 1826 against acute fatal septicemic melioidosis in this animal model is associated with a reduction of bacterial load and interference with the potential detrimental effect of the robust production of proinflammatory cytokines associated withB. pseudomalleimultiplication.
Intranasal Vaccination against Cutaneous Leishmaniasis with a Particulated Leishmanial Antigen or DNA Encoding LACK
Authors: Pinto Eduardo Fonseca , Pinheiro Roberta Olmo , Rayol Alice , Larraga Vicente , Rossi-Bergmann Bartira
Published: July 2004

We have previously demonstrated that oral delivery of a disease-promoting particulated antigen ofLeishmania amazonensis(LaAg) partially protects mice against cutaneous leishmaniasis. In the present work, we sought to optimize a mucosal vaccine by using the intranasal route for delivery of different antigen preparations, including (i) LaAg, (ii) soluble recombinant p36/LACK leishmanial antigen (LACK), and (iii) plasmid DNA encoding LACK (LACK DNA). BALB/c mice that received two intranasal doses of 10 μg of LaAg and were challenged 1 week postvaccination withL. amazonensisdeveloped delayed but effective control of lesion growth. A diminished parasite burden was accompanied by enhancement of both gamma interferon (IFN-γ) and interleukin-10 levels in the lesion-draining lymph nodes. The vaccine efficacy improved with time. At 4 months postvaccination, when a strong parasite-specific TH1-type response was present in vivo, the infection was controlled for at least 5 months after challenge. In contrast to the particulated LaAg, soluble LACK (10 μg/dose) had no effect. Interestingly, LACK DNA (30 μg/dose), but not empty DNA, promoted rapid and durable protective immunity. Parasite growth was effectively controlled, and at 5 months after challenge LACK-reactive cells in both the mucosal and lesion-draining lymph nodes produced high levels of IFN-γ. These results demonstrate for the first time the feasibility of using the intranasal route for long-lived memory vaccination against cutaneous leishmaniasis with adjuvant-free crude antigens or DNA.
Molecular Interactions of Surface Protein Peptides ofStreptococcus gordoniiwith Human Salivary Components
Authors: Hamada Tomoyuki , Kawashima Masatsugu , Watanabe Haruo , Tagami Junji , Senpuku Hidenobu
Published: July 2004

Oral streptococci play a large role in dental biofilm formation, and several types interact as early colonizers with the enamel salivary pellicle to form the primary biofilm, as well as to incorporate other bacteria on tooth surfaces. Interactions of surface molecules of individual streptococci with the salivary pellicle on the tooth surface have an influence on the etiological properties of an oral biofilm. To elucidate the molecular interactions of streptococci with salivary components, binding between surface protein (SspB and PAg) peptides ofStreptococcus gordoniiandStreptococcus sobrinuswere investigated by utilizing BIAcore biosensor technology. The analogous peptide [change of T at position 400 to K in SspB(390-402), resulting in the SspB(390-T400K-402) peptide] fromS. gordoniishowed the greatest response for binding to salivary components and inhibited the binding ofStreptococcus sanguisby more than 50% in a competitive inhibition assay in a comparison with other SspB and PAg peptides. This peptide also bound to the high-molecular-weight protein complex of salivary components and the agglutinin (gp340/DMBT1) peptide (scavenger receptor cysteine-rich domain peptide 2 [SRCRP 2]). In addition, the SspB(390-T400K-402) peptide was visualized by two surface positive charges in connection with the positively charged residues, in which lysine was a key residue for binding. Therefore, the region containing lysine may have binding activity inS. gordoniiandS. sanguis, and the SRCRP 2 region may function as a receptor for the binding. These findings may provide useful information regarding the molecular mechanism of early biofilm formation by streptococci on tooth surfaces.
Proapoptotic Effect of Proteolytic Activation of Matrix Metalloproteinases byStreptococcus pyogenesThiol Proteinase (StreptococcusPyrogenic Exotoxin B)
Authors: Tamura Fumio , Nakagawa Rumiko , Akuta Teruo , Okamoto Shigefumi , Hamada Shigeyuki , Maeda Hiroshi , Kawabata Shigetada , Akaike Takaaki
Published: July 2004

Streptococcus pyogenesthiol proteinase, also known as streptococcal pyrogenic exotoxin B (SpeB), has been suggested to be a major virulence factor inS. pyogenesinfection. SpeB was reported to induce apoptosis of host cells, but its mechanism of action is not yet fully understood. In this study, we examined the involvement of matrix metalloproteinases (MMPs) in SpeB-induced apoptosis. We first developed a large-scale preparation of recombinant SpeB and precursors of human MMP-9 and -2 (proMMPs) by usingEscherichia coliRosetta (DE3)pLysS and baculovirus-insect cell expression systems, respectively. Treatment with SpeB induced effective proteolytic activation of both proMMP-9 and -2. When RAW264 murine macrophages were incubated with SpeB-activated proMMP-9, the level of tumor necrosis factor alpha (TNF-α) in conditioned medium (CM), assessed by an enzyme immunoassay, was elevated. This increase was completely inhibited by addition of the MMP inhibitor SI-27 to the cell culture. The CM also produced marked induction of apoptosis of U937 human monocytic cells. Similarly, soluble Fas ligand (sFasL) was detected in CM of cultures of SW480 cells expressing FasL after treatment with SpeB-activated proMMPs; this CM also induced apoptosis in U937 cells. SpeB had a direct effect as well and caused the release of TNF-α and sFasL from the cells. SpeB-dependent production of MMP-9 and -2 and proapoptotic molecules (TNF-α and sFasL) was evident in a murine model of severe invasiveS. pyogenesinfection. These results suggest that SpeB or SpeB-activated MMPs contribute to tissue damage and streptococcal invasion in the host via extracellular release of TNF-α and sFasL.
Electronic Properties of GaN (0001) – Dielectric Interfaces
Authors: Cook T. E. , Fulton C. C. , Mecouch W. J. , Davis R. F. , Lucovsky G. , Nemanich R. J.
Published: July 2004

The characteristics of clean n- and p-type GaN (0001) surfaces and the interface between this surface and SiO 2, Si 3 N 4, and HfO 2 have been investigated. Layers of SiO 2, Si3 N 4, or HfO 2 were carefully deposited to limit the reaction between the film and clean GaN surfaces. After stepwise deposition, the electronic states were measured with x-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS). A valence band offset (VBO) of 2.0±0.2 eV with a conduction band offset (CBO) of 3.6±0.2 eV was determined for the GaN / SiO 2 interface. The large band offsets suggest SiO 2 is an excellent candidate for passivation of GaN . For the GaN / Si 3 N 4, interface, type II band alignment was observed with a VBO of -0.5±0.2 eV and a CBO of 2.4±0.2 eV . While Si3 N 4 should passivate n-type GaN surfaces, it may not be appropriate for p-type GaN surfaces. A VBO of 0.3±0.2 eV with a CBO of 2.1±0.2 eV was determined for the annealed GaN / HfO 2 interface. An instability was observed in the HfO 2 film, with energy bands shifting ~0.4 eV during a 650°C densification anneal. The electron affinity measurements via UPS were 3.0, 1.1, 1.8, and 2.9±0.1 eV for GaN , SiO 2, Si 3 N 4, and HfO 2 surfaces, respectively. The deduced band alignments were compared to the predictions of the electron affinity model and deviations were attributed to a change of the interface dipole. Interface dipoles contributed 1.6, 1.1 and 2.0±0.2 eV to the band alignment of the GaN / SiO 2, GaN / Si 3 N 4, and GaN / HfO 2 interfaces, respectively. It was noted that the existence of Ga-O bonding at the heterojunction could significantly affect the interface dipole, and consequently the band alignment in relation to the GaN .
Lessons learned from eClass
Authors: Brotherton Jason A. , Abowd Gregory D.
Published: July 2004

This article presents results from a study of an automated capture and access system, eClass, which was designed to capture the materials presented in college lectures for later review by students. In this article, we highlight the lessons learned from our three-year study focusing on the effect of capture and access on grades, attendance, and use of the captured notes and media. We then present suggestions for building future systems discussing improvements from our system in the capture, integration, and access of college lectures.
A formal model for reasoning about adaptive QoS-enabled middleware
Authors: Venkatasubramanian Nalini , Talcott Carolyn , Agha Gul A.
Published: July 2004

Systems that provide distributed multimedia services are subject to constant evolution; customizable middleware is required to effectively manage this change. Middleware services for resource management execute concurrently with each other, and with application activities, and can, therefore, potentially interfere with each other. To ensure cost-effective QoS in distributed multimedia systems, safe composability of resource management services is essential. In this article, we present a meta-architectural framework, the Two-Level Actor Model (TLAM) for customizable QoS-based middleware, based on the actor model of concurrent active objects. Using TLAM, a semantic model for specifying and reasoning about components of open distributed systems, we show how a QoS brokerage service can be used to coordinate multimedia resource management services in a safe, flexible, and efficient manner. In particular, we show a system in which the multimedia actor behaviors satisfy the specified requirements and provide the required multimedia service. The behavior specification leaves open the possibility of a variety of algorithms for resource management. Furthermore, constraints are identified that are sufficient to guarantee noninterference among the multiple broker resource management services, as well as providing guidelines for the safe composition of additional services.
Why Western vendors don't dominate China's ERP market
Authors: Liang Huigang , Xue Yajiong , Boulton William R. , Byrd Terry Anthony
Published: July 2004

Examining cases of failed ERP system implementation in China and explaining the unique circumstances.
Representing composites in conceptual modeling
Authors: Shanks Graeme , Tansley Elizabeth , Weber Ron
Published: July 2004

Using an object or entity class to represent a composite provides straightforward answers, making this approach superior to the use of relationship classes or associations.
What global sourcing means for U.S. IT workers and for the U.S. economy
Authors: Mann Catherine L.
Published: July 2004

The result is likely to be increased IT employment diffused throughout the U.S. economy, especially in non-tech industrial sectors.
Convergence conundrums
Authors: Fowler Dennis
Published: July 2004

"Convergence" is one of those buzz-words that refuses to die. And why should it? On the face of it, the coalescing of computers and networks and communications and electronic and electrical appliances is, well "doh," as Homer Simpson might say.
Relevance models to help estimate document and query parameters
Authors: Bodoff David
Published: July 2004

A central idea of Language Models is that documents (and perhaps queries) are random variables, generated by data-generating functions that are characterized by document (query) parameters. The key new idea of this paper is to model that a relevance judgment is also generated stochastically, and that its data generating function is also governed by those same document and query parameters. The result of this addition is that any available relevance judgments are easily incorporated as additional evidence about the true document and query model parameters. An additional aspect of this approach is that it also resolves the long-standing problem of document-oriented versus query-oriented probabilities. The general approach can be used with a wide variety of hypothesized distributions for documents, queries, and relevance. We test the approach on Reuters Corpus Volume 1, using one set of possible distributions. Experimental results show that the approach does succeed in incorporating relevance data to improve estimates of both document and query parameters, but on this data and for the specific distributions we hypothesized, performance was no better than two separate one-sided models. We conclude that the model's theoretical contribution is its integration of relevance models, document models, and query models, and that the potential for additional performance improvement over one-sided methods requires refinements.
Fault tolerance in hypercube-derivative networks (preliminary version)
Authors: Annexstein Fred
Published: July 2004

We present algorithms which reconfigure faulty deBruijn and Butterfly networks. We show that, with high probability, an
N
-node deBruijn (resp., Butterfly) network with uniformly distributed faulty processors can simulate a fault-free
N
-node deBruijn (resp., Butterfly) network with a slowdown factor of
O
(log log
N
). Our configuration algorithm is deterministic, operates in a distributed fashion, uses only local control, and takes time
O
(log
2
N
).
Optimal VLSI architectures for multidimensional DFT (preliminary version)
Authors: Bilardi Ginfranco , Hornick Scot W. , Sarrafzadeh Majid
Published: July 2004

A family of VLSI architectures for computing an (
n
1
×
n
2
× … ×
n

d

)-point multidimensional DFT (MDDFT) over ℤ
M
, the ring of integers modulo
M
, is presented. These architectures achieve VLSI area
A
=
O
((
N
2
log
2
M
)/
T
2
for any computation time
T
∊ [Ω(log
N
),
O
(√
N
log
M
)] where
N
= ∏

d

k
=1

n

k

and it is assumed that log
M
=
O
(log
N
). A lower bound argument is developed to show that the proposed architectures are area-time optimal. The applicability of these architectures to computation of the MDDFT over the complex field is also discussed. Using fixed-point arithmetic with
b
bits of precision, their area-time performance is
AT
2
=
O
(
N
2
b
2
) for any computation time
T
∊ [Ω(log
N
),
O
(√
Nb
)].
Technologies for low latency interconnection switches
Authors: Knight Thomas F.
Published: July 2004

This paper presents an engineering design for a low latency high bandwidth interconnection network which will form the switching substrate for a multi-model parallel processing system. The performance is enhanced with a variety of approaches covering interconnection protocols, routing, fault tolerance, advanced packaging, and electrical interconnection techniques. The synergistic application of these technologies leads to a high performance design.
Running algorithms efficiently on faulty hypercubes (extended abstract)
Authors: Bruck Jehoshua , Cypher Robert , Soroker Danny
Published: July 2004

We examine the issue of running algorithms with a constant factor slowdown on a faulty hypercube in a worst case scenario. We present two sets of novel results related to this issue. We first consider edge faults and show how to tolerate faults with a constant factor slow-down in communication and
no
slowdown in computation. The key to our approach is an efficient method for embedding a fault free Cube Connected Cycles (CCC) graph in the faulty hypercube. Using this embedding we can run ascend-descend algorithms (such as bitonic sort) on the faulty hypercube by implementing them on the embedded CCC. We then consider hypercubes with both edge and node faults. We prove that for any constant
c
there exists a fault-free subgraph of an
n
-dimensional hypercube with

n
c

faulty components that can implement a large class of hypercube algorithms with only a constant factor slowdown. To the best of our knowledge, this result is the first in which a hypercube can tolerate more than
O
(
n
) faults in the worst case sense.
On the potential of asynchronous pipelined processors
Authors: Ginosar Ran , Michell Nick
Published: July 2004

An asynchronous version of the pipelined R3000 and DLX processors, the A3000, is being designed. Simulation was employed to investigate the potential speed-up obtainable due to the asynchronous operation. Preliminary results show up to a 64% improvement in performance.
DSNS (dynamically-hazard-resolved statically-code-scheduled, nonuniform superscalar)
Authors: Kuga Morihiro , Murakami Kazuaki , Tomita Shinji
Published: July 2004

A new superscalar processor architecture, called DSNS (Dynamically-hazard-resolved, Statically-code-scheduled, Nonuniform Superscalar), is proposed and discussed. DSNS has the following major architectural features.1. Dynamically-hazard-resolved superscalar: DSNS is object-code compatible with respect to the degree of superscalar. Pipeline interlock hardware should be provided for detecting and resolving hazards at run time.2. Statically-cade-scheduled superscalar: The performance of DSNS could not be scalable with respect to the degree of superscalar. Compilers must be responsible for scheduling instructions to reduce the pipeline stalls for a particular degree of superscalar.3. Nonuniform superscalar: Although nonuniform superscalar potentially suffers instruction-class conflicts, it can be more cost-effective than uniform superscalar. Again compilers must take care that the class conflicts do not increase structural hazards.4. Static memory disambiguation: The DSNS architecture provides three types of LOAD/STORE instructions; strongly ordered, weakly ordered, and unordered. Memory disambiguation at compile time is responsible for marking each LOAD/STORE instruction. At run time, processors need not detect nor resolve data hazards for every type; they just perform memory accesses inorder for strongly or weakly ordered instructions, and arbitrarily for unordered.5. Static branch prediction with branch-target buffer: Branch instructions predicted as taken by compilers are stored in the branch target buffer. Hardware never guesses the outcomes of branch instructions.6. Early branch resolution with advanced conditioning: Advanced conditioning allows branch decisions to precede further the corresponding branches. It reduces the branch delay and results in resolving branches early in the pipeline.7. Conditional mode execution with dual register files: Dual register file facilitates maintaining the precise machine state that otherwise might be violated by speculative execution such as conditional mode.8. Weakly precise interrupts: The DSNS architecture defines interrupts as being somewhat imprecise but restartable with the help of interrupt handlers. The definition alleviates hardware constraints for ensuring precise interrupts strongly.This paper also presents an implementation of the DSNS architecture. The DSNS processor prototype under development is a four-stage pipelined processor of superscalar-degree four. The instruction pipelines, especially the branch pipeline, are discussed in detail.
An improved conditional branching scheme for a single instruction computer architecture
Authors: Laplante P. A.
Published: July 2004

A conditional branching scheme for the single instruction computer described in [3] is described. The new scheme is more practical than the one previously given.