bluuebunny/crossref_metadata_2025 huggingface dataset:
Online Discussion
Authors: Skinner Barbara
Published: December 2008

International students arriving at UK higher education institutions often find the first stage of the period of transition from home to British university difficult. Research has shown that the difficulties relate to finding themselves in a new culture. This University of Ulster project encouraged them to explore their feelings by participating in a series of online WebCT discussion tasks during their 6-week presessional programme with the aim of helping to mitigate any disabling effects of arriving in a new country.

The article found that virtual contact did not help students to openly express their thoughts by producing comments at an emotional level; that supportive friendships can be built across cultures as well as in conational groups and that the provision of direct advice on practical and physical problems indirectly brought emotional benefits therefore helping students to manage this time of transition more effectively.
Added Value of Combined Gene and Protein Expression of CK20 and CEA in Non—macroscopically Involved Lymph Nodes of Colorectal Cancer
Authors: D'Armento Giuseppe , Daniele Lorenzo , Mariani Sara , Ottaviani Davide , Mussa Antonio , Cassoni Paola , Sapino Anna , Bussolati Gianni
Published: December 2008

A methacarn fixation permits an approach that comprises multiple techniques. In this study the procedure is used to examine 100 mesenteric lymph nodes from patients with colon cancer by means of histology, immunohistochemistry (IHC), and reverse transcriptase polymerase chain reaction (RT-PCR). The evaluated nodes are found to be grossly free of metastases. The combined expression of both messenger RNA (mRNA) and protein is investigated to validate the presence of structural (cytokeratin 20, or CK20) and tumor-specific (carcinoembrionic antigen, or CEA) markers. Histological analysis shows micrometastases on 4 nodes. IHC analysis identifies isolated (CK20 and CEA positive) tumor cells on 14 other nodes. In this group, none of the nodes that are positive for CK20 IHC express the related mRNA. RT-PCR confirms the CEA IHC positivity in 50% of the cases. The double CEA IHC/RT-PCR positivity would have up-staged 33% of the pN0 cases to pN1. This approach offers a technological framework for further studies that aim to validate the clinical significance of protein/mRNA expression of tumor markers in colorectal cancer sentinel lymph nodes.
The Predictive Brain State: Asynchrony in Disorders of Attention?
Authors: Ghajar Jamshid , Ivry Richard B.
Published: December 2008

It is postulated that a key function of attention in goal-oriented behavior is to reduce performance variability by generating anticipatory neural activity that can be synchronized with expected sensory information. A network encompassing the prefrontal cortex, parietal lobe, and cerebellum may be critical in the maintenance and timing of such predictive neural activity. Dysfunction of this temporal process may constitute a fundamental defect in attention, causing working memory problems, distractibility, and decreased awareness.
Navigating Poorly Charted Territory
Authors: Sofaer Shoshanna
Published: December 2008

American health care is complex, fragmented, and arcane rather than being patient centered. Many patients have considerable difficulty navigating this system. As a result, care is less timely, safe, effective, and efficient. Since navigation problems are more likely for those who are sicker and less educated, they contribute to inequity. Early solutions proposed for this problem focused on the use of yet another specialized professional, the “navigator,” to help individuals find their way through the system so they get the care they need. The author defines the patient navigation problem and its probable consequences and argues that research and action are needed to (a) document the problem empirically, (b) identify underlying organizational structures and behaviors that can make navigation easy or difficult, and (c) assess whether and how policies, regulations, and improvement strategies can influence these structures and behaviors.
Digital Videoconferencing
Authors: Dudding Carol C.
Published: December 2008

The purpose of this article is to describe the technologies and applications of digital videoconferencing (DVC) within the realm of communication sciences and disorders. The discussion includes (a) a brief description of videoconferencing, (b) an explanation of the types of DVC available along with the advantages and disadvantages of each, (c) applications of DVC in preservice and in-service settings, and (d) a discussion of potential applications in research venues. DVC can occur at varying levels, requiring differing technologies, support, and funding. Educators, practitioners, and researchers in communication sciences and disorders are encouraged to consider the application of DVC in the training and supervision of future professionals, in provision of services through telepractice, and in consultation models and in research endeavors.
Veni, Vidi, Disseri
Authors: Neiheisel Jacob R. , Djupe Paul A. , Sokhey Anand E.
Published: December 2008

As the most popular voluntary association in the United States, churches are sometimes touted as saviors of democracy. However, those who espouse deliberative models of democracy rarely see churches as nurturing the decision-making abilities of attenders. Thus, the authors examine the extent to which church small group sessions fulfill the conditions for deliberation as set forth by political theorists. Using a combination of quantitative and qualitative methods, the authors find that churches offer authentic opportunities through small group involvements and, accordingly, tentatively declare the existence of a religious civility, with churches acting in the service of democratic capacity.
Evaluation of a Collaborative Wheelchair System in Cerebral Palsy and Traumatic Brain Injury Users
Authors: Qiang Zeng  , Burdet Etienne , Chee Leong Teo
Published: December 2008

Objective. This article describes the evaluation of the Collaborative Wheelchair Assistant (CWA), a robotic wheelchair that lets the user control the speed and provides guiding assistance along virtual paths programmed in software. Methods. Three people with cerebral palsy and 2 with traumatic brain injury, who had been ruled out as candidates for independent mobility, were recruited. These subjects were first trained to use the CWA with and without path guidance before completing a navigation task. Results. All subjects were able, after a few training sessions, to drive the wheelchair with path guidance safely and efficiently in an environment with obstacles and narrow passageways. The CWA enabled the subjects to drastically reduce their effort and intervention level without compromising performance. Conclusions. The results suggest that the CWA can provide driving assistance adapted to various disabilities. It could be used as a safe mobility device for some subjects who could eventually control a normal powered wheelchair after training and provide a way to increase the mobility of subjects with larger motor control or cognitive deficiencies.
Mirror Therapy Promotes Recovery From Severe Hemiparesis: A Randomized Controlled Trial
Authors: Dohle Christian , Püllen Judith , Nakaten Antje , Küst Jutta , Rietz Christian , Karbe Hans
Published: December 2008

Background. Rehabilitation of the severely affected paretic arm after stroke represents a major challenge, especially in the presence of sensory impairment. Objective. To evaluate the effect of a therapy that includes use of a mirror to simulate the affected upper extremity with the unaffected upper extremity early after stroke. Methods. Thirty-six patients with severe hemiparesis because of a first-ever ischemic stroke in the territory of the middle cerebral artery were enrolled, no more than 8 weeks after the stroke. They completed a protocol of 6 weeks of additional therapy (30 minutes a day, 5 days a week), with random assignment to either mirror therapy (MT) or an equivalent control therapy (CT). The main outcome measures were the Fugl-Meyer subscores for the upper extremity, evaluated by independent raters through videotape. Patients also underwent functional and neuropsychological testing. Results. In the subgroup of 25 patients with distal plegia at the beginning of the therapy, MT patients regained more distal function than CT patients. Furthermore, across all patients, MT improved recovery of surface sensibility. Neither of these effects depended on the side of the lesioned hemisphere. MT stimulated recovery from hemineglect. Conclusions. MT early after stroke is a promising method to improve sensory and attentional deficits and to support motor recovery in a distal plegic limb.
Laparoscopic Sleeve Gastrectomy After Gastric Banding Removal: A Feasibility Study
Authors: Frezza Eldo E. , Jaramillo-de la Torre Eduardo J. , Calleja Enriquez Carmen , Gee Laura , Wachtel Mitchell S. , Lopez Corvala Juan Antonio
Published: December 2008

Background and objectives. Laparoscopic adjustable gastric banding (LAGB) is a commonly performed bariatric procedure. When LAGB fails, restrictive procedures such as gastric bypass have been performed. Laparoscopic sleeve gastrectomy (LSG) has been suggested as an alternative, but it has not yet been fully studied. Evaluated in this report are the experiences of patients who underwent LSG, a restrictive procedure, as a rescue procedure for failed LAGB. Methods. From June 2002 to June 2007, charts of patients who underwent LAGB were reviewed to find those who had undergone LSG as a rescue procedure. Results. Of 294 patients who underwent LAGB, 10 later underwent LSG. Median excess weight loss (EWL) prior to LSG had been 34%; after LSG, median EWL was 55%. Before LSG was performed, patients had a median 11.5 comorbidities, all of which improved after LSG. No major complications or deaths resulted. Conclusion. The results suggest LSG might be a reasonable choice for patients who fail LAGB. A formal study comparing LSG with other rescue procedures should be performed.
Managing Anemia of Chronic Kidney Disease
Authors: Krikorian Susan A.
Published: December 2008

Anemia begins early in the course of declining kidney function and is a frequent complication of chronic kidney disease. Both anemia and chronic kidney disease are underdiagnosed and undertreated. Anemia is associated with significantly increased risk of morbidity and mortality, including increased risks of left ventricular hypertrophy and heart failure. Although the detrimental effects of anemia are more common in patients with advanced chronic kidney disease, it has been suggested that correcting anemia in early stage kidney disease may improve health-related quality of life and also delay the progression to end-stage kidney disease. The identification of anemia in early stage chronic kidney disease and its aggressive management may also improve cardiovascular complications. Anemia of chronic kidney disease is predominantly a result of abnormal erythropoietin production and iron deficiency. Anemia may be the result of kidney failure itself, blood losses, nutritional deficiencies, and endocrine disorders. Guidelines and protocols for treating anemia can assist practitioners in identifying patients with anemia, treating anemia, evaluating response to treatment, and modifying treatment based on response. Erythropoeisis-stimulating agents have been shown to be effective in treating anemia in predialysis and dialysis patients. Iron supplementation is usually required in patients receiving erythropoeisis-stimulating agent therapy or with iron deficiency. Successfully managing anemia of chronic kidney disease with treatment strategies that accommodate patient lifestyle and improve compliance is paramount. Primary care physicians play an important role in the care of patients with kidney disease, as does collaboration with other medical professionals involved in their care.
SHIP is required for a functional hematopoietic stem cell niche
Authors: Hazen Amy L. , Smith Michelle J. , Desponts Caroline , Winter Oliver , Moser Katrin , Kerr William G.
Published: December 2008

SH2-domain-containing inositol 5′-phosphatase-1 (SHIP) deficiency significantly increases the number of hematopoietic stem cells (HSCs) present in the bone marrow (BM). However, the reconstitution capacity of these HSCs is severely impaired, suggesting that SHIP expression might be an intrinsic requirement for HSC function. To further examine this question, we developed a model in which SHIP expression is ablated in HSCs while they are resident in a SHIP-competent milieu. In this setting, we find that long-term repopulation by SHIP-deficient HSCs is not compromised. Moreover, SHIP-deficient HSCs from this model repopulate at levels comparable with wild-type HSCs upon serial transfer. However, when HSCs from mice with systemic ablation of SHIP are transplanted, they are functionally compromised for repopulation. These findings demonstrate that SHIP is not an intrinsic requirement for HSC function, but rather that SHIP is required for the BM milieu to support functionally competent HSCs. Consistent with these findings, cells that comprise the BM niche express SHIP and SHIP deficiency profoundly alters their function.
Myeloid leukemic progenitor cells can be specifically targeted by minor histocompatibility antigen LRH-1–reactive cytotoxic T cells
Authors: Norde Wieger J. , Overes Ingrid M. , Maas Frans , Fredrix Hanny , Vos Johanna C. M. , Kester Michel G. D. , van der Voort Robbert , Jedema Inge , Falkenburg J. H. Frederik , Schattenberg Anton V. , de Witte Theo M. , Dolstra Harry
Published: December 2008

CD8+ T cells recognizing minor histocompatibility antigens (MiHAs) on leukemic stem and progenitor cells play a pivotal role in effective graft-versus-leukemia reactivity after allogeneic stem cell transplantation (SCT). Previously, we identified a hematopoiesis-restricted MiHA, designated LRH-1, which is presented by HLA-B7 and encoded by the P2X5 purinergic receptor gene. We found that P2X5 is significantly expressed in CD34+ leukemic subpopulations from chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) patients. Here, we demonstrate that LRH-1–specific CD8+ T-cell responses are frequently induced in myeloid leukemia patients following donor lymphocyte infusions. Patients with high percentages of circulating LRH-1–specific CD8+ T cells had no or only mild graft-versus-host disease. Functional analysis showed that LRH-1–specific cytotoxic T lymphocytes (CTLs) isolated from 2 different patients efficiently target LRH-1–positive leukemic CD34+ progenitor cells from both CML and AML patients, whereas mature CML cells are only marginally lysed due to down-regulation of P2X5. Furthermore, we observed that relative resistance to LRH-1 CTL-mediated cell death due to elevated levels of antiapoptotic XIAP could be overcome by IFN-γ prestimulation and increased CTL-target ratios. These findings provide a rationale for use of LRH-1 as immunotherapeutic target antigen to treat residual or persisting myeloid malignancies after allogeneic SCT.
High-level expression of the T-cell chemokines CCL3 and CCL4 by chronic lymphocytic leukemia B cells in nurselike cell cocultures and after BCR stimulation
Authors: Burger Jan A. , Quiroga Maite P. , Hartmann Elena , Bürkle Andrea , Wierda William G. , Keating Michael J. , Rosenwald Andreas
Published: December 2008

In lymphatic tissues, chronic lymphocytic leukemia (CLL) cells are interspersed with CD68+ nurselike cells (NLCs), T cells, and other stromal cells that constitute the leukemia microenvironment. However, the mechanism regulating colocalization of CLL and these accessory cells are largely unknown. To dissect the molecular cross talk between CLL and NLCs, we profiled the gene expression of CD19-purified CLL cells before and after coculture with NLCs. NLC coculture induced high-level expression of B-cell maturation antigen and 2 chemoattractants (CCL3, CCL4) by CLL cells. CCL3/CCL4 induction in NLC cocultures correlated with ZAP-70 expression by CLL cells. High CCL3/CCL4 protein levels were found in CLL cocultures with NLCs, and CCL3/CCL4 induction was abrogated by R406, a Syk inhibitor, suggesting that NLCs induce these chemokines via B-cell receptor (BCR) activation. BCR triggering also caused robust CCL3/CCL4 protein secretion by CLL cells. High CCL3 and CCL4 plasma levels in CLL patients suggest that this pathway plays a role in vivo. These studies reveal a novel mechanism of cross talk between CLL cells and their microenvironment, namely, the secretion of 2 T-cell chemokines in response to NLC coculture and BCR stimulation. Through these chemokines, CLL cells can recruit accessory cells and thereby actively create a supportive microenvironment.
Regulation of TLR4-mediated signaling by IBP/Def6, a novel activator of Rho GTPases
Authors: Chen Qinzhong , Gupta Sanjay , Pernis Alessandra B
Published: December 2008

TLRs play a fundamental role in innate immune responses. Although Rho GTPases have been implicated in TLR-mediated signaling pathways, the molecules that control their activation in response to TLR engagement are largely unknown. IFN regulatory factor-4-binding protein (IBP; which is encoded by the gene Def6) is a unique type of activator for Rac that plays a crucial role in TCR-mediated signaling and adaptive immune responses. Here, we demonstrate that IBP/Def6 also controls innate immune responses by modulating TLR-induced signaling events. Mice deficient in IBP/Def6 are protected from LPS-induced septic shock. This protection is associated with a decrease in the production of proinflammatory cytokines and is accompanied by diminished activation of MAPKs and NF-κB. Our results thus identify IBP/Def6 as a novel component of the TLR4-induced signaling cascade that controls the production of proinflammatory cytokines.
Expression and functional role of MDL-1 (CLEC5A) in mouse myeloid lineage cells
Authors: Aoki Naoko , Kimura Yuka , Kimura Shoji , Nagato Toshihiro , Azumi Makoto , Kobayashi Hiroya , Sato Keisuke , Tateno Masatoshi
Published: December 2008

Myeloid DNAX activation protein 12 (DAP12)-associating lectin-1 (MDL-1), also known as C-type lectin domain family 5, member A, is a type II transmembrane protein belonging to the C-type lectin family and associates with DAP12 (also called KARAP or TYROBP). It has been reported that two isoforms of MDL-1—long form (MDL-1L) and short form (MDL-1S)—exist in mice. Previously, we observed the marked induction of MDL-1 mRNA expression during the pulmonary mycobacterial infection in mice. The data suggested that the MDL-1-expressing cells were involved in immune responses against mycobacterial infection; however, little is known about the function of MDL-1 as yet. In this study, we demonstrated the significant protein expression of MDL-1L and MDL-1S in mouse neutrophils and macrophages. MDL-1L was highly glycosylated by N-linked glycan and sialic acid. Interestingly, the expression pattern of MDL-1 was different between neutrophils and macrophages. MDL-1 expression was notably induced during the differentiation of the mouse myeloid cell line 32Dcl3 into neutrophils. Additionally, we observed that MDL-1 stimulation induced a significant amount of RANTES and macrophage-derived chemokine production in 32Dcl3 cells in cooperation with signaling through TLR. MDL-1 stimulation also up-regulated CD11b expression and maintained cell survival. Our findings indicate that MDL-1, therefore, plays an important role in immune defense as a result of an innate immunity, which involves neutrophils and macrophages.
Expression of Bone Morphogenetic Protein Receptor (BMPR) during Perinatal Ovary Development and Primordial Follicle Formation in the Hamster: Possible Regulation by FSH
Authors: Wang Cheng , Roy Shyamal K.
Published: December 2008

To understand whether bone morphogenetic protein plays any role in the formation of primordial follicles in the hamster, we examined the temporal and spatial expression of bone morphogenetic protein receptor (BMPR) mRNA and protein in embryonic (E) 13 through postnatal day (P) 15 ovarian cells and a possible regulation by FSH during the formation of primordial follicles on P8. BMPRIA and BMPRII mRNA levels were significantly higher than that of BMPR1B throughout ovary development. BMPRIA and BMPRII mRNA levels increased significantly on E14 and declined by P5 through P6. Whereas BMPRII mRNA increased again by P7, BMPRIA mRNA levels increased through P8 concurrent with primordial follicle formation. In contrast, BMPRIB mRNA levels increased greater than 10-fold on P7-9, with a further 3-fold increase by P10. BMPR proteins were low in the somatic cells and oocytes on E13 but increased progressively during postnatal development. BMPR expression in somatic cells increased markedly on P8. Whereas BMPRII expression declined by P10 and remained steady thereafter, BMPRIA protein expression fluctuated until P15 when it became low and steady. Overall, BMPRIB immunoreactivity also declined by P10 and then remained low in the interstitial cells through P15. FSH antiserum treatment on E12 significantly attenuated receptor mRNA and protein levels by P8, but equine chorionic gonadotropin replacement on P1 reversed the inhibition. Furthermore, FSH in vitro up-regulated BMPR levels in P4 ovaries. This unique pattern of BMPR expression in the oocytes and somatic cells during perinatal ovary development suggests that BMP may play a regulatory role in primordial follicle formation. Furthermore, FSH may regulate BMP action by modulating the expression of its receptors.
Virtual trabecular bone models and their mechanical response
Authors: Donaldson F E , Pankaj P , Law A H , Simpson A H
Published: December 2008

The study of the mechanical behaviour of trabecular bone has extensively employed micro-level finite element (μFE) models generated from images of real bone samples. It is now recognized that the key determinants of the mechanical behaviour of bone are related to its micro-architecture. The key indices of micro-architecture, in turn, depend on factors such as age, anatomical site, sex, and degree of osteoporosis. In practice, it is difficult to acquire sufficient samples that encompass these variations. In this preliminary study, a method of generating virtual finite element (FE) samples of trabecular bone is considered. Virtual samples, calibrated to satisfy some of the key micro-architectural characteristics, are generated computationally. The apparent level elastic and post-elastic mechanical behaviour of the generated samples is examined: the elastic mechanical response of these samples is found to compare well with natural trabecular bone studies conducted by previous investigators; the post-elastic response of virtual samples shows that material non-linearities have a much greater effect in comparison with geometrical non-linearity for the bone densities considered. Similar behaviour has been reported by previous studies conducted on real trabecular bone. It is concluded that virtual modelling presents a potentially valuable tool in the study of the mechanical behaviour of trabecular bone and the role of its micro-architecture.
Cancellous bone screw purchase: A comparison of synthetic femurs, human femurs, and finite element analysis
Authors: Zdero R , Olsen M , Bougherara H , Schemitsch E H
Published: December 2008

Biomechanical assessments of orthopaedic fracture fixation constructs are increasingly using commercially available analogues such as the fourth-generation composite femur (4GCF). The aim of this study was to compare cancellous screw purchase directly between these surrogates and human femurs, which has not been done previously. Synthetic and human femurs each had one orthopaedic cancellous screw (major diameter, 6.5 mm) inserted along the femoral neck axis and into the spongy bone of the femoral head to a depth of 30 mm. Screws were removed to obtain pull-out force, shear stress, and energy values. The three experimental study groups ( n = 6 femurs each) were the 4GCF with a ‘solid’ cancellous matrix, the 4GCF with a ‘cellular’ cancellous matrix, and human femurs. Moreover, a finite element model was developed on the basis of the material properties and anatomical geometry of the two synthetic femurs in order to assess cancellous screw purchase. The results for force, shear stress, and energy respectively were as follows: 4GCF solid femurs, 926.47 ± 66.76 N, 2.84 ± 0.20 MPa, and 0.57 ± 0.04 J; 4GCF cellular femurs, 1409.64 ± 133.36 N, 4.31 ± 0.41 MPa, and 0.99 ± 0.13 J; human femurs, 1523.29 ± 1380.15 N, 4.66 ± 4.22 MPa, and 2.78 ± 3.61 J. No statistical differences were noted when comparing the three experimental groups for pull-out force ( p = 0.413), shear stress ( p = 0.412), or energy ( p = 0.185). The 4GCF with either a ‘solid’ or ‘cellular’ cancellous matrix is a good biomechanical analogue to the human femur at the screw thread—bone interface. This is the first study to perform a three-way investigation of cancellous screw purchase using 4GCFs, human femurs, and finite element analysis.
Blind adaptive filtering for non-invasive extraction of the fetal electrocardiogram and its non-stationarities
Authors: Graupe D , Graupe M H , Zhong Y , Jackson R K
Published: December 2008

The objective is to extract automatically a beat-to-beat fetal electrocardiogram (fECG) from a maternal electrocardiogram (mECG) using surface electrodes placed on the maternal abdomen and to derive fetal PR, QT, QTc, and QS durations to allow early diagnosis and monitoring treatment of certain fetal cardiac disorders. mECG and abdominal noise in abdominal maternal recordings can be orders of magnitude stronger than the fECG signal and the P and T waves that are embedded in them. A two-stage blind adaptive filtering algorithm was used for fECG extraction, the first stage using frequency-domain electrocardiogram features and the second considering time-domain features. Three channels of abdominal recordings were obtained from 12 patients at 20–40 weeks of gestation. In each case beat-to-beat unaveraged fECGs were isolated. The combined filter allowed identification of diagnostically important PR, QT, and RR durations. Comparison with synthetic data is also included.
The influence of tibial tray design on the wear of fixed-bearing total knee replacements
Authors: Galvin A , Jennings L M , McEwen H M , Fisher J
Published: December 2008

Debris-induced osteolysis due to surface wear is a potential long-term problem in total knee replacements (TKRs). Wear between the tibial tray and ultra-high molecular weight polyethylene insert is thought to contribute to the wear. This study investigated the influence of tibial tray design on the wear of fixed-bearing TKRs. Specifically, this study investigated the influence of the material's surface finish and design characteristics of the locking mechanism of the tibial tray on the wear in fixed-bearing knees for both cruciate-retaining (CR) and posterior-stabilized designs. A new fixed-bearing tibial tray design using Co—Cr and with an improved locking mechanism significantly reduced polyethylene wear from 22.8 ± 6.0 mm3 per 106 cycles to 15.9 ± 2.9 mm3 per 106 cycles compared with a previous titanium alloy tray with a CR design. The wear rates were similar to those of a fixed-bearing insert clamped into a tibial tray, suggesting that the decrease in wear was due to a reduction in backside wear. There was no significant difference between the wear rates of a cruciate-retaining design and a posterior-stabilized design under the two kinematic conditions tested.
Compliant-layer tibial bearing inserts: Friction testing of different materials and designs for a new generation of prostheses that mimic the natural joint
Authors: Jones E , Scholes S C , Unsworth A , Burgess I C
Published: December 2008

Total joint replacements (TJRs) have a limited lifetime, but the introduction of devices that exhibit good lubricating properties with low friction and low wear could well extend this. A novel tibial bearing design, using polyurethane (PU) as a compliant layer, to mimic the natural joint, has been developed. To determine accurately the mode of lubrication under which these joints operate, a synthetic lubricant was used in all these tests. Friction tests were carried out to assess the effects of material modulus and surface roughness, together with bearing design parameters such as bearing thickness and conformity, on lubrication. Corethane 80A was the preferred material and was chosen as the compliant layer for subsequent testing. A low surface roughness resulted in lower asperity contact as the asperities were depressed by the pressurized entraining fluid and full-fluid-film lubrication was approached. The three different tibial bearing conformities (low, medium, and high) did not appear to influence the mode of lubrication and all these bearings performed with extremely low friction. Similarly, the bearing thickness effects on lubrication at the levels tested (2 mm, 3 mm, and 4 mm) were minimal, although the effects of layer thickness on interface shear stress could be expected to be significant. This study describes a series of friction tests that have been used to select the most appropriate material and to optimize the design parameters to establish optimum conditions for these compliant layer joints.
Impact of Genetic and Environmental Factors on hsCRP Concentrations and Response to Therapeutic Agents
Authors: Shen Jian , Ordovas Jose M
Published: December 2008

Background: Inflammation plays an instrumental role in all stages of atherosclerosis. High-sensitivity C-reactive protein (hsCRP), a systemic inflammatory marker, has been gaining recognition as an independent risk factor for cardiovascular disease (CVD). Both baseline hsCRP concentrations and drug-induced hsCRP changes are highly variable and potentially subject to genetic regulation.

Content: This review summarizes the current studies examining the effect of genetic and environmental factors on baseline plasma hsCRP concentrations, with a main focus on C-reactive protein, pentraxin-related (CRP) genetic polymorphisms and various dietary components that affect hsCRP concentrations. We also address the association of CRP genetic variations with CVD risk, a relationship that may support or refute the causality of CRP in the atherosclerotic process. Moreover, we discuss the impact of CRP genetic polymorphisms on hsCRP changes in response to 3-week fenofibrate treatment in the genetic intervention of the Genetics of Lipid Lowering Drugs and Diet Network study.

Summary: Genetic variants on the CRP locus and other loci and dietary and lifestyle factors are responsible for the interindividual variability of plasma hsCRP concentrations. CRP genetic variants further influence differing plasma hsCRP response after 3-week fenofibrate treatment in patients with metabolic syndrome. Future studies focusing on the influence and interaction of genetic variation on the hsCRP response to dietary and other behavior modification as well as drug treatment could have important implications for the development of more personalized preventive and therapeutic approaches to reduce CVD.
Prospective evaluation of the natural course of idiopathic subclinical hypothyroidism in childhood and adolescence
Authors: Wasniewska Malgorzata , Salerno Mariacarolina , Cassio Alessandra , Corrias Andrea , Aversa Tommaso , Zirilli Giuseppina , Capalbo Donatella , Bal Milva , Mussa Alessandro , De Luca Filippo
Published: December 2008

Objective

To prospectively evaluate the course of subclinical hypothyroidism (SH) in children and adolescents with no underlying diseases and no risk factors, which might interfere with the progression of SH.

Design

Clinical status, thyroid function, and autoimmunity were prospectively evaluated at entry and after 6, 12, and 24 months in 92 young patients (mean age 8.1±3.0 years) with idiopathic SH.

Results

During the study, mean TSH levels showed a trend toward a progressive decrease while FT4 levels remained unchanged. Overall, 38 patients normalized their TSH (group A): 16 patients between 6 and 12 months, and 22 patients between 12 and 24 months. Among the remaining 54 patients, the majority maintained TSH within the baseline values (group B), whereas 11 exhibited a further increase in TSH above 10 mU/l (group C). Baseline TSH and FT4 levels were similar in the patients who normalized TSH, compared with those with persistent hyperthyrotropinemia. Even in the patients of group C, both TSH and FT4 at entry were not different with respect to those of groups A and B. No patients showed any symptoms of hypothyroidism during follow-up and no changes in both height and body mass index were observed throughout the observation period.

Conclusions

(a) The natural course of TSH values in a pediatric population with idiopathic SH is characterized by a progressive decrease over time; (b) the majority of patients (88%) normalized or maintained unchanged their TSH; and (c) TSH changes were not associated with either FT4 values or clinical status or auxological parameters.
Low-activity (2.0 GBq; 54 mCi) radioiodine post-surgical remnant ablation in thyroid cancer: comparison between hormone withdrawal and use of rhTSH in low-risk patients
Authors: Chianelli M , Todino V , Graziano F M , Panunzi C , Pace D , Guglielmi R , Signore A , Papini E
Published: December 2008

Objective

(a) To compare the efficacy of low-activity (2 GBq; 54 mCi) 131I ablation using l-thyroxine withdrawal or rhTSH stimulation, and (b) to assess the influence of thyroid remnants volume on the ablation rate.

Design

Patients underwent neck ultrasound, 131I neck scintigraphy and radioiodine uptake. Post-therapy whole body scan (WBS) was acquired after 4–6 days. Ablation was assessed after 6–12 months by WBS, Tg and TgAb following l-thyroxine withdrawal.

Methods

Group A: preparation by L-T4 withdrawal (37 days); 21 patients received 131I (2.02±0.22 GBq; 54.6±5.9 mCi) and on the day of treatment, TSH, Tg, TgAb were measured; Group B: stimulation by rhTSH; 21 patients received 131I (1.97±0.18 GBq; 53.2±4.9 mCi) 24 h after the second injection of rhTSH (0.9 mg) and TSH, Tg and TgAb were measured after 2 days.

Results

At follow-up, 90.0% of patients from group A and 85.0% of patients from group B had Tg levels <1 ng/ml; no uptake was observed in 95.2% and in 90.5% of patients from group A or B respectively, with no statistical differences for both ablation criteria. Before 131I treatment, small thyroid remnants (<1 ml) were detected by US in <25% of all patients.

Conclusions

The use of rhTSH for the preparation of low-risk patients to ablation therapy with low activities of 131I (2 GBq; 54 mCi) is safe and effective and avoids hypothyroidism. The presence of thyroid remnants smaller than 1 ml at US evaluation had no effect on the ablation rate.
AFM Investigation of Mechanical Properties of Dentin
Authors: Cohen Sidney R. , Apter Nathan , Jesse Stephen , Kalinin Sergei , Barlam David , Peretz Adi Idit , Ziskind Daniel , Wagner H. Daniel
Published: December 2008

Mechanical properties of peritubular dentin were investigated using scanning probe microscopy techniques, namely Nanoindentation and Band Excitation. Particular attention was directed to the possible existence of a gradient in these properties moving outward from the tubular lumen to the junction with the intertubular dentin. Finite element analysis showed that the influence of the boundaries is small relative to the effects observed. Thus, these results strongly support the concept of a lowering of modulus and hardness from the tubular exterior to its periphery, which appear to correlate with graded changes in the mineral content.
Integrated Chemical Genomics Reveals Modifiers of Survival in Human Embryonic Stem Cells
Authors: Damoiseaux Robert , Sherman Sean P. , Alva Jackelyn A. , Peterson Cory , Pyle April D.
Published: December 2008

Understanding how survival is regulated in human embryonic stem cells (hESCs) could improve expansion of stem cells for production of cells for regenerative therapy. There is great variability in comparing the differentiation potential of multiple hESC lines. One reason for this is poor survival upon dissociation, which limits selection of homogeneous populations of cells. Understanding the complexity of survival signals has been hindered by the lack of a reproducible system to identify modulators of survival in pluripotent cells. We therefore developed a high-content screening approach with small molecules to examine hESC survival. We have identified novel small molecules that improve survival by inhibiting either Rho-kinase or protein kinase C. Importantly, small molecule targets were verified using short hairpin RNA. Rescreening with stable hESCs that were genetically altered to have increased survival enabled us to identify groups of pathway targets that are important for modifying survival. Understanding how survival is regulated in hESCs could overcome severe technical difficulties in the field, namely expansion of stem cells to improve production of cells and tissues for regenerative therapy.
BAC Transgenesis in Human Embryonic Stem Cells as a Novel Tool to Define the Human Neural Lineage
Authors: Placantonakis Dimitris G. , Tomishima Mark J. , Lafaille Fabien , Desbordes Sabrina C. , Jia Fan , Socci Nicholas D. , Viale Agnes , Lee Hyojin , Harrison Neil , Tabar Viviane , Studer Lorenz
Published: December 2008

Human embryonic stem cells (hESCs) have enormous potential for applications in basic biology and regenerative medicine. However, harnessing the potential of hESCs toward generating homogeneous populations of specialized cells remains challenging. Here we describe a novel technology for the genetic identification of defined hESC-derived neural cell types using bacterial artificial chromosome (BAC) transgenesis. We generated hESC lines stably expressing Hes5::GFP, Dll1::GFP, and HB9::GFP BACs that yield green fluorescent protein (GFP)+ neural stem cells, neuroblasts, and motor neurons, respectively. Faithful reporter expression was confirmed by cell fate analysis and appropriate transgene regulation. Prospective isolation of HB9::GFP+ cells yielded purified human motor neurons with proper marker expression and electrophysiological activity. Global mRNA and microRNA analyses of Hes5::GFP+ and HB9::GFP+ populations revealed highly specific expression signatures, suggesting that BAC transgenesis will be a powerful tool for establishing expression libraries that define the human neural lineage and for accessing defined cell types in applications of human disease.
A Study of the J-Curve for Seven Selected Latin American Countries
Authors: Hsing Yu
Published: December 2008

This study finds that there is evidence of a J-curve for Chile, Ecuador, and Uruguay and lack of support for a J-curve for Argentina, Brazil, Colombia, and Peru. Increased real income in the home country would improve the trade balance for Brazil and Ecuador and deteriorate the trade balance for Argentina, Chile, Colombia, Peru, and Uruguay. Increased real income in the U.S. would improve the trade balance for Argentina, Chile, Colombia, Peru, and Uruguay and deteriorate the trade balance for Brazil and Ecuador. Hence, the conventional wisdom to pursue real depreciation to improve the trade balance may not apply to some of these countries.
Corruption and Openness
Authors: Neeman Zvika , Paserman M. Daniele , Simhon Avi
Published: December 2008

We report an intriguing empirical observation. The relationship between corruption and output depends on the economy's degree of openness: in open economies, corruption and GNP per capita are strongly negatively correlated, but closed economies display no relationship at all. This stylized fact is robust to a variety of different empirical specifications. In particular, the same basic pattern persists if we use alternative measures of openness, if we focus on different time periods, if we restrict the sample to include only highly corrupt countries, and if we restrict attention to specific geographic areas or to poor countries. We find that the degree of financial openness is primarily what determines whether corruption and output are correlated. Moreover, corruption is negatively related to capital accumulation in open economies, but not in closed economies. We present a model, consistent with these findings, in which the main channel through which corruption affects output is capital drain.
Lab-scale testing of a low-loaded activated sludge process with membrane filtration
Authors: Jakubčová Zuzana , Hlavínek Petr , Drtil Miloslav , Bodík Igor
Published: December 2008

Two membrane bioreactors (MBRs; volume = 300 L) equipped with different types of immersed membrane modules were operated simultaneously under the same laboratory conditions as a low-loaded activated sludge process without any membrane regeneration and excess sludge uptake (sludge retention time SRT up to 170 d; activated sludge concentration MLSS up to 11 g L−1). The aim was to verify the quality of treated water and to study the properties of "very old" activated sludge. Another aim was to compare different selected membrane types and choose the best one for further pilot-scale testing.
External Focus Instructions Reduce Postural Instability in Individuals With Parkinson Disease
Authors: Wulf Gabriele , Landers Merrill , Lewthwaite Rebecca , Toöllner Thomas
Published: December 2008

Background

Postural instability while standing, walking, and interacting with objects or the environment places individuals with Parkinson disease (PD) at risk for falls, injuries, and self-imposed restrictions in activity. Recent research with motor skills, including those demanding postural stability, has demonstrated performance and learning advantages when performers are instructed to adopt an external rather than an internal focus of attention. Despite the potential benefits in stability-related risk reduction and enhanced movement effectiveness, attentional focus research in individuals challenged with postural instability is limited.

Objective

The present translational research study examined the generalizability of the attentional focus effect to balance in older adults with PD.

Design

A within-participant design was used to account for potentially substantial individual variations in balancing capabilities.

Methods

Fourteen participants diagnosed with idiopathic PD (Hoehn and Yahr stages II and III) participated in the experiment. They were asked to balance on an unstable surface (inflated rubber disk). In counterbalanced orders, they were instructed to focus on reducing movements of their feet (internal focus) or the disk (external focus), or they were not given attentional focus instructions (control).

Results

The adoption of an external focus resulted in less postural sway relative to both internal focus and control conditions. There was no difference between the internal focus and control conditions.

Limitations

Mental functioning was not formally assessed, and comprehensive clinical profiles of participants were not obtained.

Conclusions

The results are consistent with previous findings on attentional focus in samples of patients and people without disabilities. Subtle wording distinctions that direct attention to movement effects external to the mover reduce postural instability during standing for individuals with PD relative to an internal focus. The findings have potentially important implications for instructions given by clinicians and the reduction of fall risk.
Byrd Station drilling 1966–69
Authors: Ueda Herbert T.
Published: December 2008

After completion of the drilling by the US Army Cold Regions Research and Engineering Laboratory (USA-CRREL) at Camp Century, Greenland, in July 1966, the operation was moved to Byrd Station, Antarctica, during the 1966/67 austral summer. The drill employed was an electromechanical cable-suspended drill that used ethylene glycol to dissolve the chips formed, producing a core with an average diameter of 114 mm. A mixture of diesel oil and trichlorethylene was used as a borehole fluid. Ice-core drilling at Byrd Station occurred from 2 to 18 February 1967 and from 12 October 1967 to 2 February 1968 when the ice sheet was penetrated at a depth of 2164 m. During the ensuing 1968/69 season the drill was lost, and ultimately the cable was severed in early 1969/70 at a depth of 1545 m. This brief report reviews the drilling operation and some of the problems encountered primarily during the 1967/68 season, with a focus on the last few days of drilling.
In situ assembly of linked geometrically coupled microdevices
Authors: Sawetzki T. , Rahmouni S. , Bechinger C. , Marr D. W. M.
Published: December 2008

Complex systems require their distinct components to function in a dynamic, integrated, and cooperative fashion. To accomplish this in current microfluidic networks, individual valves are often switched and pumps separately powered by using macroscopic methods such as applied external pressure. Direct manipulation and control at the single-device level, however, limits scalability, restricts portability, and hinders the development of massively parallel architectures that would take best advantage of microscale systems. In this article, we demonstrate that local geometry combined with a simple global field can not only reversibly drive component assembly but also power distinct devices in a parallel, locally uncoupled, and integrated fashion. By employing this single approach, we assemble and demonstrate the operation of check valves, mixers, and pistons within specially designed microfluidic environments. In addition, we show that by linking these individual components together, more complex devices such as pumps can be both fabricated and powered in situ.
Ubiquitin signals autophagic degradation of cytosolic proteins and peroxisomes
Authors: Kim Peter Kijun , Hailey Dale Warren , Mullen Robert Thomas , Lippincott-Schwartz Jennifer
Published: December 2008

Autophagy is responsible for nonspecific, bulk degradation of cytoplasmic components. Recent work has revealed also that there is specific, autophagic degradation of polyubiquitinated protein aggregates, whose buildup occurs during neurodegenerative disease. Here, we report that simple mono-ubiquitination of normally long-lived cytoplasmic substrates is sufficient to target these substrates for autophagic degradation in mammalian cells. That is, upon their ubiquitination, both small [i.e., red fluorescent protein (RFP)] and large (i.e., peroxisomes) substrates are efficiently targeted to autophagosomes and then degraded within lysosomes upon autophagosome-lysosome fusion. This targeting requires the ubiquitin-binding protein, p62, and is blocked by the Class III phosphatidylinositol 3-kinase (PI3K) inhibitor, 3-methyladenine (3-MA), or by depletion of the autophagy-related-12 (Atg12) protein homolog. Mammalian cells thus use a common pathway involving ubiquitin and p62 for targeting diverse types of substrates for autophagy.
Using large corpora of conversation to investigate narrative
Authors: Norrick Neal R.
Published: December 2008

This article describes a hybrid corpus linguistic approach to conversational storytelling, whereby one first identifies a feature of interest in a small set of narratives, then moves to a general investigation of this feature in large corpora of transcribed conversation, focusing only later on the distribution and functions of this feature within narrative portions of the corpora investigated. Interjections are conversational units par excellence with no syntactic relation to adjacent clauses, so that investigation of large corpora is particularly vital for determining their patterning and functions in conversation. I show that interjections play a number of important roles in the organization of conversational storytelling, first in justifying tellability, next in marking narrative climaxes, particularly within constructed dialogue, then in evaluating the narrative point, and finally in receiving and commenting on the storytelling performance. I further describe combinations of interjections and the interaction of interjections with exclamative clauses.