bluuebunny/crossref_metadata_2025_split huggingface dataset:
Camera Calibration Based on Snell’s Law
Authors: Lin Psang Dain , Sung Chi-Kuen 
Published: September 2006

Abstract
In this paper we present a camera calibration method using Snell’s Law. Traditional camera calibration is based on the pinhole model, which is an approximation algorithm using untrue geometrical assumptions and giving a single lumped result for the various optical elements in the camera system. Using full modeling of lens geometry, the proposed method establishes the geometric relationship between images and objects via Snell’s Law. A matrix equation that relates the intrinsic/extrinsic parameters of image the plane and six pose parameters of each element is determined from sensitivity analysis. These parameters can be identified using the least square method by observing points with known coordinates. An illustrative example using a two-camera stereo coordinate measurement system demonstrates that system performance via the proposed method is better than the pinhole model.
Dynamic Constraint-Based Energy-Saving Control of Pneumatic Servo Systems
Authors: Al-Dakkan Khalid A. , Barth Eric J. , Goldfarb Michael 
Published: September 2006

AbstractThis paper proposes a control approach that can provide significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by decoupling the standard four-way spool valve used for pneumatic servo control into two three-way valves, then using the resulting two control degrees of freedom to simultaneously satisfy a performance constraint (which for this paper is based on the sliding mode sliding condition), and an energy-saving dynamic constraint that minimizes cylinder pressures. The control formulation is presented, followed by experimental results that indicate significant energy savings with essentially no compromise in tracking performance relative to control with a standard four-way spool valve.
Adaptive Controller and Observer Design for a Class of Nonlinear Systems
Authors: Zhu Yongliang , Pagilla Prabhakar R. 
Published: September 2006

Abstract
Design of a stable adaptive controller and observer for a class of nonlinear systems that contain product of unmeasurable states and unknown parameters is considered. The nonlinear system is cast into a suitable form based on which a stable adaptive controller and observer are designed using a parameter dependent Lyapunov function. The class of nonlinear systems considered is practically relevant; mechanical systems with dynamic friction fall into this category. Experimental results on a single-link mechanical system with dynamic friction are shown for the proposed design.
Pressure Drop of Fully-Developed, Laminar Flow in Microchannels of Arbitrary Cross-Section
Authors: Bahrami M. , Yovanovich M. M. , Culham J. R. 
Published: September 2006

Abstract
The pressure drop of fully developed, laminar, incompressible flow in smooth mini- and microchannels of arbitrary cross-section is investigated. A compact approximate model is proposed that predicts the pressure drop for a wide variety of shapes. The model is only a function of geometrical parameters of the cross-section, i.e., area, perimeter, and polar moment of inertia. The proposed model is compared with analytical and numerical solutions for several shapes. Also, the comparison of the model with experimental data, collected by several researchers, shows good agreement.
Regulation of ϵ germline transcription and switch region mutations by IgH locus 3′ enhancers in transgenic mice
Authors: Laurencikiene Jurga , Tamosiunas Vytas , Severinson Eva 
Published: September 2006

AbstractGermline (GL) transcription is regulated by specific promoters and immunoglobulin heavy chain (IgH) 3′ locus enhancers and is necessary for Ig class-switch recombination (CSR). We have generated different transgenic lines containing the GL ϵ promoter, switch (S) ϵ region, and constant (C) ϵ region with or without the DNase I–sensitive regions (HS) 3A-HS1,2 or HS3B-HS4 3′ IgH enhancer pairs. The enhancerless construct was expressed in B cells activated by interleukin (IL)–4 and CD40, thus resembling regulation of the endogenous gene. Both enhancer-containing transgenes efficiently increased expression in B cells and were strongly up-regulated by stimuli. In addition, Sϵ regions of the transgene containing HS3B-HS4 were mutated in activated, sorted B cells. Such mutations are known to precede CSR and are dependent on activation-induced cytidine deaminase (AID). Our findings show that all elements necessary for recruitment of the recombination machinery are present in the transgene containing HS3 and HS4. These enhancers probably provide something more specific than mere increased accessibility of switch regions. We propose that transcription factors binding the enhancers help to target the recombination machinery to the switch regions.
Oncogenic role of Pax5 in the T-lymphoid lineage upon ectopic expression from the immunoglobulin heavy-chain locus
Authors: Souabni Abdallah , Jochum Wolfram , Busslinger Meinrad 
Published: September 2006

AbstractFour of 9 PAX transcription factor genes have been associated with chromosomal translocations in human tumors, although their oncogenic potential has not yet been demonstrated in transgenic mouse models. The B-lymphoidPAX5 gene participates in the generation of the t(9;14)(p13;q32) translocation in germinal center B cells, which leads to deregulated PAX5 expression under the control of the immunoglobulin heavy-chain (IgH) locus in a subset of B-cell non-Hodgkin lymphomas. Here we reconstructed a human t(9;14) translocation in a knock-in mouse by inserting a PAX5 minigene into the IgH locus. The IgHP5ki allele, which corresponds to a germline rather than somatic mutation, is activated in multipotent hematopoietic progenitors and is subsequently expressed in dendritic cells (DCs) and in natural killer (NK), T, and B cells. Ectopic Pax5 expression interferes with normal T-cell development and causes immature T-lymphoblastic lymphomas in IgHP5ki/+ and IgHP5ki/P5ki mice. Aggressive T-cell lymphomas develop even faster in IkPax5/+ mice expressing Pax5 from the Ikaros locus. Pax5 expression in thymocytes activates B-cell–specific genes and represses T-lymphoid genes, suggesting that Pax5 contributes to lymphomagenesis by deregulating the T-cell gene-expression program. These data identify Pax5 as a potent oncogene and demonstrate that the T-lymphoid lineage is particularly sensitive to the oncogenic action of Pax5.
Efficiency of T-cell receptor expression in dual-specific T cells is controlled by the intrinsic qualities of the TCR chains within the TCR-CD3 complex
Authors: Heemskerk Mirjam H. M. , Hagedoorn Renate S. , van der Hoorn Menno A. W. G. , van der Veken Lars T. , Hoogeboom Manja , Kester Michel G. D. , Willemze Roel , Falkenburg J. H. Frederik 
Published: September 2006

AbstractGenetic engineering of T lymphocytes is an attractive strategy to specifically redirect T-cell immunity toward viral infections and malignancies. We previously demonstrated redirected antileukemic reactivity of cytomegalovirus (CMV)–specific T cells by transfer of minor histocompatibility antigen HA-2–specific T-cell receptors (TCRs). HA-2–TCR-transferred CMV-specific T cells were potent effectors against HA-2–expressing leukemic cells, as well as CMV-expressing cells. Functional activity of these T cells correlated with TCR cell-surface expression. In the present study we analyzed which properties of transferred and endogenous TCRs are crucial for efficient cell-surface expression. We demonstrate that expression of the introduced TCR is not a random process but is determined by characteristics of both the introduced and the endogenously expressed TCR. The efficiency of TCR cell-surface expression is controlled by the intrinsic quality of the TCR complex. In addition, we demonstrate that chimeric TCRs can be formed and that efficiency of TCR expression is independent of whether TCRs are retrovirally introduced or naturally expressed. In conclusion, introduced, endogenous, and chimeric TCRs compete for cell-surface expression in favor of the TCR-CD3 complex with best-pairing properties.
Foamy virus–mediated gene transfer to canine repopulating cells
Authors: Kiem Hans-Peter , Allen James , Trobridge Grant , Olson Erik , Keyser Kirsten , Peterson Laura , Russell David W. 
Published: September 2006

AbstractFoamy virus (FV) vectors are particularly attractive gene-transfer vectors for stem-cell gene therapy because they form a stable transduction intermediate in quiescent cells and can efficiently transduce hematopoietic stem cells. Here, we studied the use of FV vectors to transduce long-term hematopoietic repopulating cells in the dog, a clinically relevant large animal model. Mobilized canine peripheral blood (PB) CD34+ cells were transduced with an enhanced green fluorescent protein (EGFP)–expressing FV vector in an 18-hour transduction protocol. All 3 dogs studied had rapid neutrophil engraftment to greater than 500/μL with a median of 10 days. Transgene expression was detected in all cell lineages (B cells, T cells, granulocytes, red blood cells, and platelets), indicating multilineage engraftment of transduced cells. Up to 19% of blood cells were EGFP+, and this was confirmed at the DNA level by real-time polymerase chain reaction (PCR) and Southern blot analysis. These transduction rates were higher than the best results we obtained previously with lentiviral vectors in a similar transduction protocol. Integration site analysis also demonstrated polyclonal repopulation and the transduction of multipotential hematopoietic repopulating cells. These data suggest that FV vectors should be useful for stem-cell gene therapy, particularly for applications in which short transduction protocols are critical.
A first insight into the genetic diversity of Mycobacterium tuberculosis in Dar es Salaam, Tanzania, assessed by spoligotyping
Authors: Eldholm Vegard , Matee Mecky , Mfinanga Sayoki GM , Heun Manfred , Dahle Ulf R 
Published: September 2006

Abstract

Background
Tanzania has a high tuberculosis incidence, and genotyping studies of Mycobacterium tuberculosis in the country are necessary in order to improve our understanding of the epidemic. Spoligotyping is a potentially powerful genotyping method due to fast generation of genotyping results, high reproducibility and low operation costs. The recently constructed SpolDB4 database and the model-based program 'Spotclust' can be used to assign isolates to families, subfamilies and variants. The results of a study can thus be analyzed in a global context.

Results
One hundred forty-seven pulmonary isolates from consecutive tuberculosis patients in Dar es Salaam were spoligotyped. SpolDB4 and 'Spotclust' were used to assign isolates to families, subfamilies and variants. The CAS (37%), LAM (22%) and EAI (17%) families were the most abundant. Despite the dominance of these three families, diversity was high due to variation within M. tuberculosis families. Of the obtained spoligopatterns, 64% were previously unrecorded.

Conclusion
Spoligotyping is useful to gain an overall understanding of the local TB epidemic. This study demonstrates that the extensive TB epidemic in Dar es Salaam, Tanzania is caused by a few successful M. tuberculosis families, dominated by the CAS family. Import of strains was a minor problem.
Malaria hotspot areas in a highland Kenya site are consistent in epidemic and non-epidemic years and are associated with ecological factors
Authors: Ernst Kacey C , Adoka Samson O , Kowuor Dickens O , Wilson Mark L , John Chandy C 
Published: September 2006

Abstract

Background
Malaria epidemics in highland areas of East Africa have caused considerable morbidity and mortality in the past two decades. Knowledge of "hotspot" areas of high malaria incidence would allow for focused preventive interventions in resource-poor areas, particularly if the hotspot areas can be discerned during non-epidemic periods and predicted by ecological factors.

Methods
To address this issue, spatial distribution of malaria incidence and the relationship of ecological factors to malaria incidence were assessed in the highland area of Kipsamoite, Kenya, from 2001–2004.

Results
Clustering of disease in a single geographic "hotspot" area occurred in epidemic and non-epidemic years, with a 2.6 to 3.2-fold increased risk of malaria inside the hotspot, as compared to outside the area (P < 0.001, all 4 years). Altitude and proximity to the forest were independently associated with increased malaria risk in all years, including epidemic and non-epidemic years.

Conclusion
In this highland area, areas of high malaria risk are consistent in epidemic and non-epidemic years and are associated with specific ecological risk factors. Ongoing interventions in areas of ecological risk factors could be a cost-effective method of significantly reducing malaria incidence and blunting or preventing epidemics, even in the absence of malaria early warning systems. Further studies should be conducted to see if these findings hold true in varied highland settings.
The early responses of VEGF and its receptors during acute lung injury: implication of VEGF in alveolar epithelial cell survival
Authors: Mura Marco , Han Bing , Andrade CristianoF , Seth Rashmi , Hwang David , Waddell Thomas K , Keshavjee Shaf , Liu Mingyao 
Published: September 2006

Abstract
Introduction
The function of the vascular endothelial growth factor (VEGF) system in acute lung injury (ALI) is controversial. We hypothesized that the role of VEGF in ALI may depend upon the stages of pathogenesis of ALI.

Methods
To determine the responses of VEGF and its receptors during the early onset of ALI, C57BL6 mice were subjected to intestinal ischemia or sham operation for 30 minutes followed by intestinal ischemia-reperfusion (IIR) for four hours under low tidal volume ventilation with 100% oxygen. The severity of lung injury, expression of VEGF and its receptors were assessed. To further determine the role of VEGF and its type I receptor in lung epithelial cell survival, human lung epithelial A549 cells were treated with small interference RNA (siRNA) to selectively silence related genes.

Results
IIR-induced ALI featured interstitial inflammation, enhancement of pulmonary vascular permeability, increase of total cells and neutrophils in the bronchoalveolar lavage (BAL), and alveolar epithelial cell death. In the BAL, VEGF was significantly increased in both sham and IIR groups, while the VEGF and VEGF receptor (VEGFR)-1 in the lung tissues were significantly reduced in these two groups. The increase of VEGF in the BAL was correlated with the total protein concentration and cell count. Significant negative correlations were observed between the number of VEGF or VEGFR-1 positive cells, and epithelial cells undergoing cell death. When human lung epithelial A549 cells were pre-treated with 50 nM of siRNA either against VEGF or VEGFR-1 for 24 hours, reduced VEGF and VEGFR-1 levels were associated with reduced cell viability.

Conclusion
These results suggest that VEGF may have dual roles in ALI: early release of VEGF may increase pulmonary vascular permeability; reduced expression of VEGF and VEGFR-1 in lung tissue may contribute to the death of alveolar epithelial cells.
Exposure to Mycobacterium avium can modulate established immunity against Mycobacterium tuberculosis infection generated by Mycobacterium bovis BCG vaccination
Authors: Flaherty David K , Vesosky Bridget , Beamer Gillian L , Stromberg Paul , Turner Joanne 
Published: September 2006

Abstract
Mycobacterium bovis bacille Calmette Guerin (BCG), the current vaccine against infection with Mycobacterium tuberculosis, offers a variable, protective efficacy in man. It has been suggested that exposure to environmental mycobacteria can interfere with the generation of BCG-specific immunity. We hypothesized that exposure to environmental mycobacteria following BCG vaccination would interfere with established BCG immunity and reduce protective efficacy, thus modeling the guidelines for BCG vaccination within the first year of life. Mice were vaccinated with BCG and subsequently given repeated oral doses of live Mycobacterium avium to model exposure to environmental mycobacteria. The protective efficacy of BCG with and without subsequent exposure to M. avium was determined following an aerogenic challenge with M. tuberculosis. Exposure of BCG-vaccinated mice to M. avium led to a persistent increase in the number of activated T cells within the brachial lymph nodes but similar T cell activation profiles in the lungs following infection with M. tuberculosis. The capacity of BCG-vaccinated mice to reduce the bacterial load following infection with M. tuberculosis was impaired in mice that had been exposed to M. avium. Our data suggest that exposure to environmental mycobacteria can negatively impact the protection afforded by BCG. These findings are relevant for the development of a vaccine administered in regions with elevated levels of environmental mycobacteria.
Premature Mortality in Patients with Addison’s Disease: A Population-Based Study
Authors: Bergthorsdottir Ragnhildur , Leonsson-Zachrisson Maria , Odén Anders , Johannsson Gudmundur 
Published: September 2006

Abstract
Background: The survival rate of patients with primary adrenal insufficiency (Addison’s disease) undergoing currently accepted replacement therapy is not known, although well-informed patients are considered to have a normal survival rate. In this study, we evaluated the mortality of patients with Addison’s disease in Sweden.
Methods: A population-based, retrospective, observational study was performed, using the National Swedish Hospital and Cause of Death Registers, covering the period from 1987–2001. After a diagnosis of Addison’s disease, each patient was followed until the end of follow-up or death. Mortality was compared with that of the Swedish background population.
Findings: We identified 1675 patients (995 women and 680 men) diagnosed with primary adrenal insufficiency. The average follow-up from initial diagnosis was 6.5 yr. Five hundred seven patients died during the study period compared with an expected 199. The risk ratio for all-cause mortality was 2.19 (confidence interval 1.91–2.51) for men and 2.86 (confidence interval 2.54–3.20) for women. The excess mortality in both men and women was attributed to cardiovascular, malignant, and infectious diseases. Concomitant diabetes mellitus was observed in 12% of the patients, but only contributed to the increased mortality to a minor extent.
Interpretation: Compared with the background population, we observed that the risk ratio for death was more than 2-fold higher in patients with Addison’s disease. Cardiovascular, malignant, and infectious diseases were responsible for the higher mortality rate.
Dynamic Strength Training Improves Insulin Sensitivity without Altering Plasma Levels and Gene Expression of Adipokines in Subcutaneous Adipose Tissue in Obese Men
Authors: Klimcakova E. , Polak J. , Moro C. , Hejnova J. , Majercik M. , Viguerie N. , Berlan M. , Langin D. , Stich V. 
Published: September 2006

AbstractContext: Obesity is characterized by a low-grade inflammatory state, which could play a role in insulin resistance. Dynamic strength training improves insulin sensitivity.Objective: The objective of this study was to investigate, in obese subjects, whether the insulin sensitizing effect of dynamic strength training is associated with changes in plasma levels and gene expression of adipokines potentially involved in the development of insulin resistance.Design: Twelve obese male subjects were investigated before and at the end of 3 months of dynamic strength training. Insulin sensitivity was evaluated using euglycemic-hyperinsulinemic clamp. Blood samples and needle biopsy samples of sc abdominal adipose tissue were obtained. The plasma levels and adipose tissue mRNA levels of adiponectin, leptin, IL-1β, IL-6, and TNF-α were determined.Results: The training induced an increase in the whole-body glucose disposal rate by 24% (P = 0.04). The body weight was not altered during the training. Plasma levels of leptin decreased during the training (16.6 ± 6.3 vs. 13.1 ± 5.7 ng/ml) by 21% (P &lt; 0.02), whereas no change in plasma levels of other adipokines and C-reactive protein was observed. Gene expression of the investigated adipokines was not changed in sc adipose tissue during the training.Conclusions: In obese subjects, the dynamic strength training resulted in an improvement of whole-body insulin sensitivity. The increase in insulin sensitivity was not associated with training-induced modifications of plasma levels or adipose tissue gene expression of adipokines supposedly involved in the development of insulin resistance.
Acromegaly and Somatotroph Hyperplasia with Adenomatous Transformation Due to Pituitary Metastasis of a Growth Hormone-Releasing Hormone-Secreting Pulmonary Endocrine Carcinoma
Authors: Nasr Christian , Mason Alexander , Mayberg Marc , Staugaitis Susan M. , Asa Sylvia L. 
Published: September 2006

Abstract
Context: GHRH excess from extracranial endocrine tumors is known to cause somatotroph hyperplasia and acromegaly. Hypothalamic gangliocytomas producing GHRH are also known to be associated with pituitary adenomas causing acromegaly.
Objectives: The objective of this study was to describe a case of acromegaly due to a pulmonary GHRH-secreting endocrine carcinoma with metastasis to the pituitary gland and to look at the peculiar histological features of this case.
Subject: The patient was a 44-yr-old woman who was diagnosed with a biopsy-proven metastatic pulmonary endocrine tumor during pregnancy. After delivery, she underwent radiation and chemotherapy for pulmonary and skeletal metastases. Her disease was clinically stable for 7 yr until she developed bitemporal hemianopia. She had symptoms and signs of acromegaly.
Methods: Imaging, biochemical, and histological studies were performed.
Results: Magnetic resonance imaging (MRI) of the brain confirmed the presence of a 2.6-cm lesion within the sella turcica extending above the sella and compressing the optic chiasm. Endocrine studies showed elevated serum levels of GH, prolactin, α-subunit of glycoprotein hormones, IGF-I, chromogranin A, and GHRH. The patient underwent uneventful transsphenoidal resection of the sellar tumor. Postoperatively, she noted an improvement in symptoms of acromegaly. Histological examination confirmed metastatic endocrine carcinoma to the pituitary, and immunohistochemistry localized GHRH to the tumor cells. The adjacent pituitary exhibited somatotroph hyperplasia with abundant reactivity for GH and α-subunit. In addition, there was focal neoplastic transformation to a sparsely granulated somatotroph phenotype with fibrous bodies.
Conclusion: This is the first report of a GHRH-producing endocrine tumor metastasizing to the pituitary and causing local hyperstimulation with somatotroph hyperplasia and adenomatous transformation.