bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amplitude‐phase constraints based blind and semi‐blind channel estimation for OFDM systems
Authors: Chen Wei , Liu Guang‐hui , Zhu Wei‐le 
Published: March 2012

ABSTRACTIn this paper, a new blind channel estimation method for orthogonal frequency division multiplexing systems is presented. The proposed approach based on the amplitude‐phase constraints of the channel frequency response first estimates the channel amplitude‐frequency response, and then calculates the channel‐frequency response of the equivalent minimum phase system by its amplitude‐frequency response. The zeros of the actual system and its equivalent minimum phase system are symmetric about the unit circle, and the symmetric relationships are easily determined according to the finite alphabet property of information symbols. A semi‐blind estimation method based on the blind estimation method is also proposed in this paper, and it greatly reduces the numerical complexity of the blind method. Unlike existing statistical blind channel estimators, the proposed method requires short data records especially for phase‐shift keying modulation. Compared with the existing finite alphabet based method, the proposed method has a lower numerical complexity. Comparison of the proposed method with training based estimation method, which is presented by computer simulations, show the effectiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
A simple SPH algorithm for multi‐fluid flow with high density ratios
Authors: Monaghan J. J. , Rafiee Ashkan 
Published: March 2012

SUMMARYIn this paper, we describe an SPH algorithm for multi‐fluid flow, which is efficient, simple and robust. We derive the inviscid equations of motion from a Lagrangian together with the constraint provided by the continuity equation. The viscous flow equations then follow by adding a viscous term. Rigid boundaries are simulated using boundary force particles in a manner similar to the immersed boundary method. Each fluid is approximated as weakly compressible with a speed of sound sufficiently large to guarantee that the relative density variations are typically 1%. When the SPH force interaction is between two particles of different fluids, we increase the pressure terms. This simple procedure stabilizes the interface between the fluids. The equations of motion are integrated using a time stepping rule based on a second‐order symplectic integrator. When linear and angular momentum should be conserved exactly, they are conserved to within round‐off errors. We test the algorithm by simulating a variety of problems involving fluids with a density ratio in the range 1–1000. The first of these is a free surface problem with no rigid boundaries. It involves the flow of an elliptical distribution with one fluid inside the other. We show that the simulations converge as the particle spacing decreases, and the results are in good agreement with the exact inviscid, incompressible theory. The second test is similar to the first but involves the nonlinear oscillation of the fluids. As in the first test, the agreement with theory is very good, and the method converges. The third test is the simulation of waves at the interface between two fluids. The method is shown to converge, and the agreement with theory is satisfactory. The fourth test is the Rayleigh–Taylor instability for a configuration considered by other authors. Key parameters are shown to converge, and the agreement with other authors is good. The fifth and final test is how well the SPH method simulates gravity currents with density ratios in the range 2–30. The results of these simulations are in very good agreement with those of other authors and in satisfactory agreement with experimental results.Copyright © 2012 John Wiley & Sons, Ltd.
A qualitative study of HIV testing and referral practices of private hospital doctors treating patients with TB in Chennai, India
Authors: Miller Rosalind , Parkhurst Justin O. , Peckham Stephen , Singh Raj B. 
Published: March 2012

ABSTRACTObjectiveIn India, 50%–80% of patients with tuberculosis (TB) seek private care. This study set out to explore HIV testing and referral practices of private hospital doctors treating patients with TB.MethodsInterviews were conducted with private hospital doctors (n = 15). Interviews covered HIV testing, linking HIV‐positive patients with TB to HIV care, and coordination of care for co‐infected patients.ResultsDoctors did not routinely refer patients with TB to government HIV testing facilities as per national policy guidance. If deemed appropriate, then testing was conducted privately. Testing was more common when a facility guideline mandated testing or a public–private initiative for TB management was in place. Otherwise, testing was based on doctors' judgement. Patients accustomed to private care who could not afford treatment were reportedly reluctant to shift to public facilities. A lack of communication between public and private doctors was found to undermine co‐management.ConclusionsIn this sample, private provider practices were influenced by both the social and the health systems contexts in which they operated. An understanding of patient perceptions of HIV, private doctors concerns for retaining patients, and the contrasting philosophies of private medicine versus public health objectives was found to be critical to explain HIV testing and referral behaviours. The government has proposed to scale up HIV testing and treatment among patients with TB, yet operationalising this will require engagement with the realities of a large, diverse private sector. It will also require considering what role government policies can have on shaping private practice and how to potentially integrate public and private care. Copyright © 2012 John Wiley & Sons, Ltd.
TRIP-1: A regulator of osteoblast function
Authors: Metz-Estrella Diana , Jonason Jennifer H , Sheu Tzong-Jen , Mroczek-Johnston Rachel M , Puzas J Edward 
Published: March 2012

Abstract
Transforming growth factor β (TGFβ) receptor interacting protein-1 (TRIP-1) is an intracellular protein expressed in osteoblasts with high affinity for type 5b tartrate resistant acid phosphatase (TRAP). It is suggested that through this interaction, TRIP-1 serves as a positive regulator of TGFβ signaling and osteoblast differentiation during bone remodeling. We show here that TRIP-1 is abundant in osteoblasts in vivo and in vitro. TRIP-1 mRNA and protein expression were increased at early stages and decreased at later stages during osteoblast differentiation, suggesting a predominant role during early maturation. To investigate a role during bone remodeling, primary osteoblasts were treated with different hormones and factors that are known to affect remodeling. TRIP-1 levels were decreased with dexamethasone and increased with vitamin D3, dihydrotestosterone (DHT), TGFβ1, and bone morphogenic protein 2 (BMP-2). Treatment with parathyroid hormone (PTH) and β-estradiol did not affect TRIP-1 levels. Transfected small interfering RNA (siRNA) against TRIP-1 inhibited osteoblast differentiation as characterized by a decrease in alkaline phosphatase staining and enzyme activity, and decrease in the expression of collagen I, alkaline phosphatase, Runx2, osteopontin, and osteocalcin. The proliferation of osteoblasts was also affected by TRIP-1 siRNA. This particular effect was defined by decreased cell number, marked reduction of cyclin D1, a 38% decrease of cells in S phase (p &lt; 0.001) and a 97% increase of cells in the G2/M phase (p &lt; 0.01) of the cell cycle. However, TRIP-1 siRNA did not induce an effect in apoptosis. Using a TGFβ luciferase reporter we found that knocking down TRIP-1 decreased the activation of TGFβ signaling by 40% percent (p &lt; 0.001). In conclusion, our characterization of TRIP-1 in osteoblasts provides the first evidence of its key role as a positive regulator of osteoblast function. © 2012 American Society for Bone and Mineral Research.
Therapeutic effects of intrabone and systemic mesenchymal stem cell cytotherapy on myeloma bone disease and tumor growth
Authors: Li Xin , Ling Wen , Khan Sharmin , Yaccoby Shmuel 
Published: March 2012

Abstract
The cytotherapeutic potential of mesenchymal stem cells (MSCs) has been evaluated in various disorders including those involving inflammation, autoimmunity, bone regeneration, and cancer. Multiple myeloma (MM) is a systemic malignancy associated with induction of osteolytic lesions that often are not repaired even after prolonged remission. The aims of this study were to evaluate the effects of intrabone and systemic injections of MSCs on MM bone disease, tumor growth, and tumor regrowth in the severe combined immunodeficiency (SCID)-rab model and to shed light on the exact localization of systemically injected MSCs. Intrabone injection of MSCs, but not hematopoietic stem cells, into myelomatous bones prevented MM-induced bone disease, promoted bone formation, and inhibited MM growth. After remission was induced with melphalan treatment, intrabone-injected MSCs promoted bone formation and delayed myeloma cell regrowth in bone. Most intrabone or systemically injected MSCs were undetected 2 to 4 weeks after injection. The bone-building effects of MSCs were mediated through activation of endogenous osteoblasts and suppression of osteoclast activity. Although a single intravenous injection of MSCs had no effect on MM, sequential weekly intravenous injections of MSCs prevented MM-induced bone disease but had no effect on tumor burden. MSCs expressed high levels of anti-inflammatory (eg, HMOX1) and bone-remodeling (eg, Decorin, CYR61) mediators. In vitro, MSCs promoted osteoblast maturation and suppressed osteoclast formation, and these effects were partially prevented by blocking decorin. A subset of intravenously or intracardially injected MSCs trafficked to myelomatous bone in SCID-rab mice. Although the majority of intravenously injected MSCs were trapped in lungs, intracardially injected MSCs were mainly localized in draining mesenteric lymph nodes. This study shows that exogenous MSCs act as bystander cells to inhibit MM-induced bone disease and tumor growth and that systemically injected MSCs are attracted to bone by myeloma cells or conditions induced by MM and inhibit bone disease. © 2012 American Society for Bone and Mineral Research.
Reference Intervals and Factors Contributing to Serum Cystatin C Levels in a Chinese Population
Authors: Li Dong‐Dong , Zou Meng‐Na , Hu Xin , Zhang Mei , Jia Cheng‐Yao , Tao Chuan‐Min , Wang Lan‐Lan , Ying Bin‐Wu 
Published: March 2012

BackgroundSerum cystatin C (Cys‐C), an inhibitor of cysteine proteases, has been suggested as an ideal biomarker of glomerular filtration rate (GFR).ObjectivesThe objective of this study was to describe the reference intervals of serum Cys‐C and identify factors associated with serum Cys‐C or its variability, including age, gender, creatinine (Crea), blood urea nitrogen (BUN), and uric acid (UA).Design and MethodsSerum Cys‐C, Crea, BUN, and UA were measured in 4,517 healthy participants aged 8–89 years attending our hospital. Serum Cys‐C was analyzed using a latex‐enhanced immunoturbidimetric method. Crea were tested by picric acid jaffe method, BUN, and UA by kinetic UV assays.ResultsThe predominant characteristic of Cys‐C distribution was that Cys‐C concentration in age ≥60 years group was the highest (P < 0.05). The differences of Cys‐C concentration between males and females existed for subjects aged from 30 to 59 years (P < 0.05). In a multiple model adjusted only for gender and age, gender (β = 0.007) has stronger effect on Cys‐C levels, compared with age (β = 0.003). The clinical variables, comprised of age, gender, Crea, BUN, and UA, involved in the fully adjusted equation accounted for 37.6% of variation of Cys‐C.ConclusionsNinety‐five percent reference intervals for healthy population were partitioned into three categories only by age, 0.59–1.07 mg/L for subjects aged 19–59 years; 0.74–1.14 mg/L for the older aged ≥60 years; and 0.63–1.11 mg/L for children aged ≤18 years. Serum Cys‐C is significantly related to gender, age, UA, Crea, and BUN. Besides, there are still other factors contributing to variation of Cys‐C levels.
Bone Turnover Markers Failed to Predict the Occurrence of Osteonecrosis of the Femoral Head—A Preliminary Study
Authors: Floerkemeier Thilo , Hirsch Stefanie , Budde Stefan , Radtke Kerstin , Thorey Fritz , Windhagen Henning , von Lewinski Gabriela 
Published: March 2012

Background: The early detection of osteonecrosis of the femoral head (ONFH) is difficult, but important for prevention of destruction of the femoral head. The objective of this study was to determine whether the occurrence of osteonecrosis of the femoral head (ONFH) correlates with changes in bone turnover markers.Methods: In 40 patients undergoing primary total hip arthroplasty (THA), different bone turnover markers and hormones (bone specific alkaline phosphatase, osteocalcin, beta cross‐laps, 25‐hydroxy‐cholecalciferol, and parathormone) gained from blood were determined on the morning of the surgery. Twenty‐two patients needed a THA due to progressed ONFH. In 18 cases blood was gained from patients with the indication for a THA given due to advanced osteoarthritis (AO) of the hip.Results: Bone specific alkaline phosphatase, osteocalcin, beta cross‐laps, and parathormone did not show any deviation from standard values, neither for the group of osteonecrosis nor for the osteoarthritis group. 25‐Hydroxy‐cholecalciferol revealed on average decreased values without significant differences between both groups (P < 0.05).The tested bone turnover markers and hormones failed to predict the occurrence of ONFH. Thus, the focus has to be put on different parameters to find a specific parameter that possibly predicts the risk of ostenecrosis and that is suited to follow up ONFH.
Effect of Pneumatic Tube Delivery System Rate and Distance on Hemolysis of Blood Specimens
Authors: Evliyaoğlu Osman , Toprak Gülten , Tekin Alicem , Başarali Mustafa Kemal , Kilinç Cumhur , Çolpan Leyla 
Published: March 2012

BackgroundWe evaluated the effects of pneumatic tube system (PTS) transport rates and distances on routine hematology and coagulation analysis. PTS effects on centrifuged blood samples were also examined.MethodThe study was completed at Dicle University Hospital, which has the longest pneumatic tube system in Turkey. Blood samples were collected at three different locations within the hospital and an emergency department, and delivered to the central laboratory by the PTS or a human carrier. Samples were transported at different rates and over varying distances. Each specimen's potassium (K) and lactic dehydrogenase (LDH) levels, in both the serum and plasma, were tracked to monitor hemolysis. Measurements of LDH and K were obtained using heparin or citrate.ResultA positive correlation was observed between distance and hemolysis in serum samples transported at 4.2 m/sec, and at 3.1 m/sec for more than 2200 m (r = 0.774 and r = 0.766, respectively). Distance and hemolysis were also correlated in non‐centrifuged samples (r = 0.871). The alterations in plasma LDH and K levels at different rates and PTS lengths were not statistically significant.ConclusionThe rate of hemolysis in PTS transported samples, dependent on PTS length and rate, may seriously affect routine tests of non‐centrifuged samples.
RHD Allelic Identification Among D−Brazilian Blood Donors as a Routine Test Using Pools of DNA
Authors: Mota Mariza , Dezan M. , Valgueiro M.C. , Sakashita A.M. , Kutner J.M. , Castilho L. 
Published: March 2012

BackgroundRHD alleles leading to a reduced expression of D antigen of the red blood cell (RBC) surface may be erroneously typed as D− by serology and may cause anti‐D immunizations when transfused to recipients.MethodsTo determine the occurrence of such alleles among apparent D− blood donors, molecular typing was implemented as a routine test using a pool of DNA. A total of 2,450 pretyped D− samples were tested in pools of 10 for the RHD‐specific polymorphism in intron 4 and exon 7. Samples in polymer chain reaction (PCR) positive pools were individually reevaluated by exon‐specific PCRs, sequencing, and serologic methods.ResultsAmong 2,450 serologically D− blood donor samples tested, 101 (4.1%) carried the RHD gene. Nonfunctional RHD (RHDψ, RHD*CE(2–9)‐D, and RHD*CE(3–7)‐D), different weak D alleles such as RHD*weak D type 1, RHD*weak D type 4.3, RHD*weak D type 5, RHD*weak D type 38, and RHD*DEL were identified.ConclusionWe employed a PCR‐based assay for RHD as a routine test using pools of ten DNA blood donor samples. The integration of RHD genotyping into the routine screening program using pools of DNA samples was straightforward. As a consequence, 19 (0.8%) blood donors carrying a weak D and Del phenotypes with the potential of causing anti‐D immunizations in recipients were reclassified as D+. For each population, it would be necessary to adapt the RHD genotyping strategy to the spectrum of prevalent alleles.
Visfatin Levels in Nonalcoholic Fatty Liver Disease
Authors: Akbal Erdem , Koçak Erdem , Taş Adnan , Yüksel Enver , Köklü Seyfettin 
Published: March 2012

PurposeRecently, role of adipokin in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) has been suggested. Among adipokins, role of leptin and adiponectin is rather well known; however, there are only a few data concerning visfatin.Material and MethodsNAFLD is confirmed in 30 patients by ultrasonography. As a control group, patients without fatty liver or other liver diseases were included. Viral hepatitis, metabolic liver diseases, and autoimmune hepatitis and consumption of alcohol were excluded in all patients. Fasting serum level of visfatin was determined by ELISA method.ResultsSerum visfatin concentration in the NAFLD group (14.7 ± 8.1 ng/ml) was significantly higher than in controls (9.4 ± 1.6 ng/ml) (P < 0.001). There were no correlations between visfatin and anthropometric parameters, transaminases, lipids, and homeostasis model assessment‐estimated insulin resistance (HOMA‐IR).ConclusionSerum visfatin concentration increases in patients with NAFLD.
On the acceleration of the numerical solution of partial differential equations using radial basis functions and graphics processing units
Authors: Elliott Hutchcraft W. , Woolsey Maxwell , Gordon Richard K. 
Published: March 2012

ABSTRACTGeneral purpose computation on graphics processing units is becoming very important as a means for speeding up numerical computations. In this research, nVidia's Compute Unified Device Architecture (CUDA) language is used along with a graphics processing unit to accelerate the generation of the system matrix for the numerical solution of a partial differential equation employing radial basis functions. Details of the CUDA implementation as well as speedup curves using several different graphics processing units will be discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Transient analysis of printed lines using finite‐difference time‐domain method
Authors: Ahmed Shahid 
Published: March 2012

SUMMARYComprehensive studies of ultra‐wideband pulses and electromagnetic coupling on printed coupled lines have been performed using full‐wave 3D finite‐difference time‐domain analysis. Effects of unequal phase velocities of coupled modes, coupling between line traces, and the frequency dispersion on the waveform fidelity and crosstalk have been investigated in detail. To discriminate the contributions of different mechanisms into pulse evolution, single and coupled microstrip lines without (ϵr = 1) and with (ϵr > 1) dielectric substrates have been examined. To consistently compare the performance of the coupled lines with substrates of different permittivities and transients of different characteristic times, a generic metric similar to the electrical wavelength has been introduced. The features of pulse propagation on coupled lines with layered and pedestal substrates and on the irregular traces have been explored. Physical interpretations of the simulation results are discussed in the paper. Copyright © 2012 John Wiley & Sons, Ltd.
Etiologic causes of late osteocutaneous free flap failures in oral cavity cancer reconstruction
Authors: Zender Chad A. , Mehta Vikas , Pittman Amy L. , Feustel Paul J. , Jaber James J. 
Published: March 2012

AbstractObjectives/Hypothesis:To evaluate perioperative complications in a homogeneous cohort undergoing microvascular osteocutaneous free flap (OCFF) reconstruction following segmental mandibulectomy for advanced oral cancer and to identify the causes of late OCFF failures.Study Design:Retrospective chart review.Methods:The records of 65 adults who underwent a segmental mandibulectomy for primary oral cavity cancer followed by single‐stage reconstruction OCFF were reviewed. Early and late complications were identified and their associations to patients' independent variables and to each other were analyzed to assess etiologic causes of late OCFF failure.Results:The incidence of early and late complications mirrored each another at 29%, and a 95% early‐success rate was achieved. An early complication did predict an early infection (odds ratio [OR], 63.3; 95% confidence interval [CI], 6.8‐585.3). Furthermore, an early perioperative infection impacted the incidence of late complications (OR, 4.8; 95% CI, 1.3‐18.3), and moreover severely impacted the incidence of osteomyelitis/osteoradionecrosis (OR, 8.8; 95% CI, 1.8‐41.9) and late failures (OR, 12.8; 95% CI, 1.9‐84.5).Conclusions:Mandibular reconstruction following segmental mandibulectomy provides immediate restoration but is often plagued with perioperative complications that are difficult to predict. Early perioperative infections impact patient long‐term morbidity by increasing the risk of late graft failure by almost 13‐fold. Consequently, it is felt that early aggressive treatment of these infections may reduce the incidence and severity of late complications and improve patient outcomes. Laryngoscope, 2012
Consumer Decision Making Regarding a “Green” Everyday Product
Authors: Thøgersen John , Jørgensen Anne‐Katrine , Sandager Sara 
Published: March 2012

ABSTRACTOne of the techniques marketers use to convert low‐involvement products into high‐involvement ones is adding an important product feature. A case in point is the common practice of adding a “green” or environmentally friendly product feature to an everyday product, something which is often assumed to elevate consumer involvement in the choice of the product. However, there is a lack of research investigating whether adding such a “green” product attribute actually makes any difference to how consumers make choices. Does the way in which consumers make decisions about groceries change when both “green” and conventional alternatives are available? Does it make them deliberate more or do they just develop another, simple choice heuristic? Based on observation and follow‐up interviews of consumers at the milk counter in two supermarkets which stock both organic (a “green” attribute) and conventional milk, it is concluded that, rather than changing the way consumers make decisions when buying this type of product, the availability of a “green” alternative seems to make “green” consumers develop a new, simple choice heuristic that allows them to do their shopping as effortless and time‐efficient as consumers buying conventional products.