bluuebunny/crossref_metadata_2025 huggingface dataset:
Rupture of the cranial cruciate ligament associated with deformity of the proximal tibia in five dogs
Authors: Selmi A. L. , Filho J. G. Padilha
Published: April 2008

Excessive mechanical stress due to caudal sloping of the tibial plateau may result in early breakdown of the cranial cruciate ligament (CrCL). Five dogs with CrCL rupture associated with caudal sloping of the proximal tibial plateau are described. All were small dogs, of between three and six years of age, with a mean bodyweight of 9‐3 kg, which had acute hlndlimb lameness. Radiographic examination revealed cranial displacement of the tibia, with a tibial angle varying from 58 to 60°. All cases were treated with a lateral fabellotiblal suture and cranial cuneiform osteotomy of the proximal tibia. All dogs were using the operated limb three days after surgery, with normal gait re‐established after a mean period of 10 days. Excessive tibial plateau sloping is not a frequent cause of hlndlimb lameness in small animals, although it Is Important to consider it as a predisposing factor for rupture of the CrCL.
Prevalence of odontoclastic resorptive lesions in a population of clinically healthy cats
Authors: Ingham K. E. , Gorrel C. , Blackburn J. , Farnsworth W.
Published: April 2008

The prevalence of odontoclastic resorptive lesions (ORLs) was determined in a clinically healthy cat population (228 cats) using both clinical (oral examination) and radiographic (full‐mouth series with intraorally positioned dental film) methods. The overall prevalence rate was 29 per cent (mean age of the cat population 4–9 years). The mandibular third premolars (307,407) were the most commonly affected tooth and the pattern of ORL development was symmetrical in most cats. The risk of having ORLs was found to increase with increasing age and cats with clinically and radiographically missing teeth were more likely to have the condition. Neutering, gender, age at neutering or mean whole mouth gingivitis index did not affect the prevalence of ORLs.
Extraskeletal fibroblastic osteosarcoma in a rabbit (Oryctolagus cuniculus)
Authors: Renfrew H. , Rest J. R. , Holden A. R.
Published: April 2008

A seven‐year‐old rabbit was presented with a non‐painfui mass in the right upper lip. Tissue samples from the mass at three different stages of the disease process were diagnosed sequentially as an osteogenic sarcoma, a fibroblastic tumour with rudimentary osteoid formation and, lastly, a fibrosarcoma. No bone involvement or metastatic disease was found. The final diagnosis was of an extraskeletal fibroblastic osteosarcoma, which is, to the authors' knowledge, the first reported such case in a domestic rabbit. Without the first two tissue samples, an incorrect diagnosis would have been reached; therefore, this disease may be underrepresented in the literature.
Radiography and ultrasonography in the diagnosis and treatment of abdominal enlargements in five guinea pigs
Authors: Beregi A. , Molnar V. , Perge E. , Felkai C.
Published: April 2008

Five guinea pigs with palpable abdominal masses were examined by radiography and ultrasonography, and laparotomy was performed. Splenic haematoma, splenic and uterine haemangioma, uterine fibroma and ovarian teratoma were found on histological examination after excision of the relevant organs. Both of the imaging methods allowed localisation of the affected organs, but the inner structure of the masses could only be imaged by ultrasonography. Ultrasonography served as an aid in decision‐making with respect to the laparotomy. Surgery was successful in four out of the five cases. Both imaging methods were found to be useful in diagnosis and in determining the choice of treatment in cases of abdominal masses in guinea pigs.
Identifying Early Cardiovascular Disease to Target Candidates for Treatment
Authors: Duprez Daniel A. , Cohn Jay N.
Published: April 2008

Most attempts to identify individuals at risk for cardiovascular morbid events have involved screening for risk factors. These traditional risk factors do not identify the underlying atherosclerotic disease nor assess the severity of disease in individual patients. The goal for identifying a marker or markers for early cardiovascular disease that could serve as a surrogate for disease progression and ultimate morbid events is to improve the precision for early detection and treatment. The authors utilize a variety of techniques, which consist of 7 vascular tests (large and small artery elasticity, resting blood pressure and exercise blood pressure response, optic fundus photography, carotid intimal‐media thickness, and microalbuminuria) and 3 cardiac tests (electrocardiography, [N‐terminal pro‐] B‐type natriuretic peptide, and left ventricular ultrasonography). Each test is individually scored, and the total disease score is the sum of all the test scores. A study is ongoing to compare the new disease score vs the classical Framingham risk estimate in the prediction of cardiovascular events.
Mail Education Is as Effective as In‐Class Education in Hypertensive Korean Patients
Authors: Kim Miyong T. , Kim Eun‐Young , Han Hae‐Ra , Jeong Seonghee , Lee Jong Eun , Park Hyun Jeong , Kim Kim B. , Hill Martha N.
Published: April 2008

Many Korean American persons have hypertension, but competing life priorities often prevent them from attending health‐promotion educational activities. Using principles of community‐based participatory research, the authors conducted a prospective clinical trial to determine the effectiveness of a mailed vs an in‐class culturally tailored education intervention. A total of 380 hypertensive Korean American persons from the Baltimore/Washington area were assigned to a more intense in‐class education group or a less intensive mail education group. Evaluation of postintervention blood pressure (BP) outcomes revealed that significant reductions in systolic BP (13.3 mm Hg and 16.1 mm Hg, respectively) and diastolic BP (9.5 mm Hg and 10.9 mm Hg) and increases in BP control rates (42.3% and 54.3%) were achieved in both groups. No significant differences in BP outcomes between groups, however, were found. In conclusion, education by mail was an effective strategy for improving BP control and may be a viable approach for other immigrant groups if the education materials address their cultural needs.
Electrocardiographic Left Ventricular Hypertrophy Regression Induced by an Angiotensin Receptor Blocker‐Based Regimen in Hypertensive Patients With the Metabolic Syndrome: Data From the SARA Study
Authors: Escobar Carlos , Barrios Vivencio , Calderón Alberto , Barrios Sara , Echarri Rocio , Navarro‐Cid Josefa , Ferrer Elena , Fernandez Raúl
Published: April 2008

The authors assessed the effect of an angiotensin receptor blocker (candesartan)‐based regimen on electrocardiographic left ventricular hypertrophy (ECG‐LVH) in 276 patients with hypertension, including 141 with the metabolic syndrome (MS). Baseline blood pressure (BP) and ECG‐LVH parameters did not differ in patients with and without MS. At the study's end, BP had decreased similarly in both groups. At baseline, 26.1% of patients with MS and 24.7% without MS exhibited ECG‐LVH by Cornell product (CorP) criteria (P=NS); 26.8% and 17.2%, respectively, by Sokolow‐Lyon product (SokP) (P=.01); 11.4%and 11.8% by Cornell voltage (CorV) (P=NS); and 12.4% and 6.5% by Sokolow‐Lyon voltage (SokV) (P=.01). At the study's end, in the MS group, prevalence of ECG‐LVH was reduced to 19.5% from 26.1% (P=.001), to 8.5% from 11.4% (P=.01), and to 24.4% from 26.8%(P=.03) by CorP, CorV, and SokP, respectively. In patients without MS, only the CorP criterion showed a significant decrease in ECG‐LVH prevalence, declining to 20.5% (P=.01). The relative risk reduction of ECG‐LVH was higher in patients with MS according to CorV and SokP criteria (P<.01).
Pay (Adequately) For What Works: The Economic Undervaluation of Office and Ambulatory Blood Pressure Recordings
Authors: Giles Thomas D. , Egan Peter
Published: April 2008

When they tell you it's not about the money—it's about the money.—H.L. Mencken (not verified)
Experimental and Theoretical Analysis of Transient Response of Plate Heat Exchangers in Presence of Nonuniform Flow Distribution
Authors: Srihari N. , Das Sarit K.
Published: April 2008

Transient analysis helps us to predict the behavior of heat exchangers subjected to various operational disturbances due to sudden change in temperature or flow rates of the working fluids. The present experimental analysis deals with the effect of flow distribution on the transient temperature response for U-type and Z-type plate heat exchangers. The experiments have been carried out with uniform and nonuniform flow distributions for various flow rates. The temperature responses are analyzed for various transient characteristics, such as initial delay and time constant. It is also possible to observe the steady state characteristics after the responses reach asymptotic values. The experimental observations indicate that the Z-type flow configuration is more strongly affected by flow maldistribution compared to the U-type in both transient and steady state regimes. The comparison of the experimental results with numerical solution indicates that it is necessary to treat the flow maldistribution separately from axial thermal dispersion during modeling of plate heat exchanger dynamics.
On the Physics of Heat Transfer and Aerodynamic Behavior of Separated Flow Along a Highly Loaded Low Pressure Turbine Blade Under Periodic Unsteady Wake Flow and Varying of Turbulence Intensity
Authors: Schobeiri M. T. , Öztürk B. , Kegalj M. , Bensing D.
Published: April 2008

This paper attempts to provide a detailed insight into the heat transfer and aerodynamic behavior of a separation zone that is generated as a result of boundary layer development along the suction surface of a highly loaded low pressure turbine blade. This paper experimentally investigates the individual and combined effects of periodic unsteady wake flows and freestream turbulence intensity (Tu) on heat transfer and aerodynamic behavior of the separation zone. Heat transfer experiments were carried out at Reynolds numbers of 110,000, 150,000, and 250,000 based on the suction surface length and the cascade exit velocity. Aerodynamic experiments were performed at Re=110,000. For the above Re numbers, the experimental matrix includes Tu’s of 1.9%, 3.0%, 8.0%, and 13.0% and three different unsteady wake frequencies with the steady inlet flow as the reference configuration. Detailed heat transfer and boundary layer measurements are performed with particular attention paid to the heat transfer and aerodynamic behavior of the separation zone at different Tu’s at steady and periodic unsteady flow conditions. The objectives of the research are (a) to quantify the effect of Tu on the aerothermal behavior of the separation bubble at steady inlet flow conditions, (b) to investigate the combined effects of Tu and the unsteady wake flow on the aerothermal behavior of the separation bubble, and (c) to provide a complete set of heat transfer and aerodynamic data for numerical simulation that incorporates Navier–Stokes and energy equations. The experimental investigations were performed in a large-scale, subsonic, unsteady turbine cascade research facility at the Turbomachinery Performance and Flow Research Laboratory of Texas A&M University.
Temperature/Heat Analysis of Annular Fins of Hyperbolic Profile Relying on the Simple Theory for Straight Fins of Uniform Profile
Authors: Campo Antonio , Cui Jianhong
Published: April 2008

This technical brief addresses an elementary analytic procedure for solving approximately the quasi-1D heat conduction equation (a generalized Airy equation) governing the annular fin of hyperbolic profile. The importance of this fin configuration stems from the fact that its geometrical shape and heat transfer performance are reminiscent of the annular fin of convex parabolic profile, the so-called optimal annular fin. To avoid the disturbing variable coefficient in the quasi-1D heat conduction equation, usage of the mean value theorem for integration is made. Thereafter, invoking a coordinate transformation, the product is a differential equation, which is equivalent to the quasi-1D heat conduction equation for the simple straight fin of uniform profile. The nearly exact analytic temperature distribution is conveniently written in terms of the two controlling parameters: the normalized radii ratio c and the dimensionless thermogeometric parameter M2, also called the enlarged Biot number. For engineering analysis and design, the estimates of temperatures and heat transfer rates for annular fins of hyperbolic profile owing realistic combinations of c and M2 give evidence of good quality.
Heat Transfer Resulting From the Interaction of a Vortex Pair With a Heated Wall
Authors: Martin Roland , Zenit Roberto
Published: April 2008

The motion of a two-dimensional vortex pair moving toward a wall is studied numerically. The case for which the wall is heated is analyzed. The equations of momentum and energy conservation are solved using a finite volume scheme. In this manner, the instantaneous heat transfer from the wall is obtained and is related to the dynamics of the fluid vortex interacting with the wall. It was found that, as expected, when the fluid vortex approaches the wall, the heat transfer increases significantly. The heat transfer changes in a nonmonotonic manner as a function of time: When the vortex first reaches the wall, a volume of heated fluid is convected from the wall; this fluid volume circulates in the vicinity of the wall, causing the rate of heat transfer to decrease slightly, to then increase again. A wide range of Prandtl and Reynolds numbers were tested. A measure of the effective heat transfer coefficient, or Nusselt number, is proposed.
Transient Critical Heat Fluxes of Subcooled Water Flow Boiling in a Short Vertical Tube Caused by Exponentially Increasing Heat Inputs
Authors: Hata Koichi , Noda Nobuaki
Published: April 2008

The transient critical heat fluxes (CHFs) of the subcooled water flow boiling for the flow velocities (u=4.0–13.3m∕s), the inlet subcoolings (ΔTsub,in=68.08–161.12K), the inlet pressures (Pin=718.31–1314.62kPa), the dissolved oxygen concentrations (O2=2.94ppm to the saturated one), and the exponentially increasing heat inputs (Q0exp(t∕τ), τ=16.82msto15.52s) are systematically measured with an experimental water loop comprised of a pressurizer. The SUS304 tubes of the inner diameters (d=3mm, 6mm, 9mm, and 12mm), heated lengths (L=33.15–132.9mm), L∕d=5.48–11.08, and wall thickness (δ=0.3mm and 0.5mm) with the rough finished inner surface (surface roughness, Ra=3.18μm) are used in this work. The transient CHF data (qcr,sub=6.91–60MW∕m2) are compared with the values calculated by the steady state CHF correlations against inlet and outlet subcoolings. The transient CHF correlations against inlet and outlet subcoolings are derived based on the experimental data. The dominant mechanisms of the subcooled flow boiling CHF for a high heating rate are discussed.
USAYPT Holds Annual February Tournament
Authors: Oldaker Bruce
Published: April 2008

The United States Association for Young Physicists Tournaments (USAYPT) held its annual U.S. Invitational Young Physicists Tournament Feb. 8–9, 2008, at the North Carolina School for Science and Mathematics in Durham, NC. Young physicists tournaments are theoretical and experimental research-based team competitions described more fully at the USAYPT website: http://www.usaypt.org.
Surface Mobility of Postsynaptic AMPARs Tunes Synaptic Transmission
Authors: Heine Martin , Groc Laurent , Frischknecht Renato , Béïque Jean-Claude , Lounis Brahim , Rumbaugh Gavin , Huganir Richard L. , Cognet Laurent , Choquet Daniel
Published: April 2008

AMPA glutamate receptors (AMPARs) mediate fast excitatory synaptic transmission. Upon fast consecutive synaptic stimulation, transmission can be depressed. Recuperation from fast synaptic depression has been attributed solely to recovery of transmitter release and/or AMPAR desensitization. We show that AMPAR lateral diffusion, observed in both intact hippocampi and cultured neurons, allows fast exchange of desensitized receptors with naïve functional ones within or near the postsynaptic density. Recovery from depression in the tens of millisecond time range can be explained in part by this fast receptor exchange. Preventing AMPAR surface movements through cross-linking, endogenous clustering, or calcium rise all slow recovery from depression. Physiological regulation of postsynaptic receptor mobility affects the fidelity of synaptic transmission by shaping the frequency dependence of synaptic responses.
Connecting the Dots
Authors: Mertens Stephan
Published: April 2008

Nets, Puzzles, and Postmen
. An Exploration of Mathematical Connections.
By Peter M. Higgins
. Oxford University Press, Oxford, 2007. 255 pp. $29.95, £15.99. ISBN 9780199218424.

The author offers interested nonspecialists an engaging introduction to the mathematics of networks.
Current-Controlled Magnetic Domain-Wall Nanowire Shift Register
Authors: Hayashi Masamitsu , Thomas Luc , Moriya Rai , Rettner Charles , Parkin Stuart S. P.
Published: April 2008

The controlled motion of a series of domain walls along magnetic nanowires using spin-polarized current pulses is the essential ingredient of the proposed magnetic racetrack memory, a new class of potential non-volatile storage-class memories. Using permalloy nanowires, we achieved the successive creation, motion, and detection of domain walls by using sequences of properly timed, nanosecond-long, spin-polarized current pulses. The cycle time for the writing and shifting of the domain walls was a few tens of nanoseconds. Our results illustrate the basic concept of a magnetic shift register that relies on the phenomenon of spin-momentum transfer to move series of closely spaced domain walls.
Electronic Origin of the Inhomogeneous Pairing Interaction in the High-
T
c
Superconductor Bi
2
Sr
2
CaCu
2
O
8+δ
Authors: Pasupathy Abhay N. , Pushp Aakash , Gomes Kenjiro K. , Parker Colin V. , Wen Jinsheng , Xu Zhijun , Gu Genda , Ono Shimpei , Ando Yoichi , Yazdani Ali
Published: April 2008

Identifying the mechanism of superconductivity in the high-temperature cuprate superconductors is one of the major outstanding problems in physics. We report local measurements of the onset of superconducting pairing in the high–transition temperature (
T
c
) superconductor Bi
2
Sr
2
CaCu
2
O
8+δ
using a lattice-tracking spectroscopy technique with a scanning tunneling microscope. We can determine the temperature dependence of the pairing energy gaps, the electronic excitations in the absence of pairing, and the effect of the local coupling of electrons to bosonic excitations. Our measurements reveal that the strength of pairing is determined by the unusual electronic excitations of the normal state, suggesting that strong electron-electron interactions rather than low-energy (<0.1 volts) electron-boson interactions are responsible for superconductivity in the cuprates.
Convergence of
Campylobacter
Species: Implications for Bacterial Evolution
Authors: Sheppard Samuel K. , McCarthy Noel D. , Falush Daniel , Maiden Martin C. J.
Published: April 2008

The nature of species boundaries in bacteria remains controversial. In particular, the mechanisms of bacterial speciation and maintenance in the face of frequent genetic exchange are poorly understood. Here, we report patterns of genetic exchange that show two closely related zoonotic pathogenic species,
Campylobacter jejuni
and
Campylobacter coli
, are converging as a consequence of recent changes in gene flow. Population expansion into a novel ecological niche generated by human activity is the most probable explanation for the increase in genetic exchange between these species. Bacterial speciation can therefore occur by mechanisms analogous to those seen in metazoans, where genetic diversification and incipient speciation caused by ecological factors have been reported in several genera.
Return to Natural History
Authors: Sagarin Raphael D.
Published: April 2008

Return to Warden's Grove
. Science, Desire, and the Lives of Sparrows.
By Christopher Norment
. University of Iowa Press, Iowa City, IA, 2008. 231 pp. $26. ISBN 9781587296338. Iowa Series in Literary Nonfiction.

Focusing on the author's fieldwork in Canada's Northwest Territories of Canada, this memoir makes a thoughtful case for building holistic understanding of systems through careful and repeated observations at small scales.
LruA and LruB Antibodies in Sera of Humans with Leptospiral Uveitis
Authors: Verma Ashutosh , Rathinam S. R. , Priya C. Gowri , Muthukkaruppan V. R. , Stevenson Brian , Timoney John F.
Published: April 2008

Uveitis can be a serious complication of leptospirosis. Previous studies indicated that the leptospiral lipoproteins LruA and LruB are expressed in the eyes of uveitic horses and that antibodies directed against those proteins show in vitro cross-reactivity with components of equine lens, ciliary body, and/or retina. We now demonstrate that sera from a significant proportion of humans who have leptospiral uveitis also contain antibodies against LruA and LruB. Different categories of nonleptospiral uveitis and autoimmune uveitis were also screened; patients diagnosed with Fuchs uveitis or Behçet's syndrome produced antibodies that cross-reacted with LruA and LruB, suggesting similarities of the autoimmune responses in those diseases with those of leptospiral uveitis.
Dendritic Cells Differentiated in the Presence of a Single-Stranded Viral RNA Sequence Conserve Their Ability To Activate CD4 T Lymphocytes but Lose Their Capacity for Th1 Polarization
Authors: Marin-Esteban Viviana , Abdul Mubashira , Charron Dominique , Haziot Alain , Mooney Nuala
Published: April 2008

Monocyte-derived dendritic cells (DCs) differentiate in the presence of Toll-like-receptor (TLR) ligands in the course of ongoing infections. A single-stranded RNA (ssRNA) sequence, corresponding to the sequence of the U5 region of human immunodeficiency virus type 1 RNA, was used to mimic viral activation of TLR7 in human DCs. We determined the effector potential of DCs differentiated in the presence of this ssRNA molecule (ssRNA-DCs). ssRNA-DCs phenotypically resembled mature DCs. In contrast, their capacity to allostimulate naive CD4
+
T cells resembled that of conventional immature DCs and could be increased by TLR4 stimulation. Th1 polarization of CD4
+
T cells and production of interleukin 12p70 (IL-12p70) by ssRNA-DCs were selectively abrogated in response to a late TLR4, but not in response to a CD40, maturation signal. Inhibition of p38 mitogen-activated protein kinase partially restored IL-12p70 secretion but did not restore Th1 polarization, whereas addition of exogenous IL-12 led to recovery of Th1 polarization. In contrast to lipopolysaccharide, ssRNA induced IL-12p70 production at the very earliest stages of DC differentiation, indicating a particular role for TLR7 in monocyte-derived DCs recently engaged in differentiation. These data demonstrate generation of phenotypically mature DCs with the ability to expand CD4
+
T lymphocytes lacking Th1/2-polarizing capacity.
Association of Strong Immune Responses to PPE Protein Rv1168c with Active Tuberculosis
Authors: Khan Nooruddin , Alam Kaiser , Nair Shiny , Valluri Vijaya Lakshmi , Murthy Kolluri J. R. , Mukhopadhyay Sangita
Published: April 2008

Accurate diagnosis of tuberculosis (TB) infection is critical for the treatment, prevention, and control of TB. Conventional diagnostic tests based on purified protein derivative (PPD) do not achieve the required diagnostic sensitivity. Therefore, in this study, we have evaluated the immunogenic properties of Rv1168c, a member of the PPE family, in comparison with PPD, which is routinely used in the tuberculin test, and Hsp60 and ESAT-6, well-known immunodominant antigens of
Mycobacterium tuberculosis
. In a conventional enzyme immunoassay, the recombinant Rv1168c protein displayed stronger immunoreactivity against the sera obtained from patients with clinically active TB than did PPD, Hsp60, or ESAT-6 and could distinguish TB patients from
Mycobacterium bovis
BCG-vaccinated controls. Interestingly, Rv1168c antigen permits diagnosis of smear-negative pulmonary TB as well as extrapulmonary TB cases, which are often difficult to diagnose by conventional tests. The immunodominant nature of Rv1168c makes it a promising candidate to use in serodiagnosis of TB. In addition, our studies also show that Rv1168c is a potent T-cell antigen which elicits a strong gamma interferon response in sensitized peripheral blood mononuclear cells obtained from TB patients.
In Vitro Replication of Varicella-Zoster Virus in Human Retinal Pigment Epithelial Cells
Authors: Schmidt-Chanasit Jonas , Bleymehl Karoline , Rabenau Holger F. , Ulrich Rainer G. , Cinatl Jindrich , Doerr Hans Wilhelm
Published: April 2008

Here we describe for the first time the productive in vitro infection of human retinal pigment epithelial cells by varicella-zoster virus (VZV), resulting in a typical cytopathic effect (CPE) that is characterized by enlarged cells with increased granularity. Depending on the CPE dissemination, high titers of up to 1.6 × 10
6
PFU of cell-free and cryostable VZV/ml can be recovered.
Development and Evaluation of a Novel Multiplex PCR Technology for Molecular Differential Detection of Bacterial Respiratory Disease Pathogens
Authors: Benson Robert , Tondella Maria L. , Bhatnagar Julu , Carvalho Maria da Glória S. , Sampson Jacquelyn S. , Talkington Deborah F. , Whitney Anne M. , Mothershed Elizabeth , McGee Lesley , Carlone George , McClee Vondguraus , Guarner Jeannette , Zaki Sherif , Dejsiri Surang , Cronin K. , Han Jian , Fields Barry S.
Published: April 2008

The ResPlex I assay (Qiagen) was designed to amplify and detect DNA of six bacterial respiratory pathogens. This assay was compared with real-time PCR assays based upon the same target sequences for the ability detect the target bacteria by use of both stock strains and specimens from respiratory disease patients. The ResPlex I assay is somewhat less sensitive than real-time PCR assays but offers the advantage of multiple assays in a single reaction.
Comparison of Sensitivities of Two Commercial Gamma Interferon Release Assays for Pulmonary Tuberculosis
Authors: Chee Cynthia B. E. , Gan Suay H. , KhinMar Kyi W. , Barkham Timothy M. , Koh Chwee K. , Liang Shen , Wang Yee T.
Published: April 2008

There are few head-to-head comparisons of the commercial gamma interferon release assays (GIRAs). We compared the performance of the T-SPOT.
TB
and QuantiFERON-TB Gold In-Tube (QFT-IT) assays in patients with culture-proven pulmonary tuberculosis. Blood was drawn for both assays within 14 days of starting antituberculosis treatment. The QFT-IT indeterminate rate was 3.5%; the T-SPOT.
TB
failure rate was 1.4%. There was poor agreement between the GIRAs (κ = 0.257) among the 270 patients with valid results for both tests. The sensitivities of the T-SPOT.
TB
and QFT-IT assays were 94.1 and 83.0%, respectively, with a significant difference in the performance of the assays (
P
= 0.001 [McNemar test]). Factors independently associated with indeterminate QFT-IT results were an age of ≥60 years (odds ratio [OR] 11.18, 95% confidence interval [CI] = 1.841 to 67.823,
P
= 0.009), female sex (OR = 7.47, 95% CI = 1.517 to 36.733,
P
= 0.013) and non-Chinese (i.e., Indian or Malay) race (OR = 7.89, 95% CI = 1.585 to 39.267,
P
= 0.012). The QFT-IT assay was significantly less sensitive in patients ≥60 years old (OR = 0.41, 95% CI = 0.181 to 0.918,
P
= 0.030) and in Indian compared to Chinese patients (OR = 0.27, 95% CI = 0.073 to 0.990,
P
= 0.048). The T-SPOT.
TB
assay was significantly less sensitive in Malay (OR = 0.23, 95% CI = 0.063 to 0.815,
P
= 0.023) and Indian patients (OR = 0.09, 95% CI = 0.017 to 0.429,
P
= 0.003) compared to Chinese patients. The performance of both assays was not significantly altered in diabetics. The diminished sensitivity of the GIRAs in persons of Malay and Indian race merits further study.
Critical Role of Conserved Hydrophobic Residues within the Major Homology Region in Mature Retroviral Capsid Assembly
Authors: Purdy John G. , Flanagan John M. , Ropson Ira J. , Rennoll-Bankert Kristen E. , Craven Rebecca C.
Published: April 2008

During retroviral maturation, the CA protein undergoes dramatic structural changes and establishes unique intermolecular interfaces in the mature capsid shell that are different from those that existed in the immature precursor. The most conserved region of CA, the major homology region (MHR), has been implicated in both immature and mature assembly, although the precise contribution of the MHR residues to each event has been largely undefined. To test the roles of specific MHR residues in mature capsid assembly, an in vitro system was developed that allowed for the first-time formation of Rous sarcoma virus CA into structures resembling authentic capsids. The ability of CA to assemble organized structures was destroyed by substitutions of two conserved hydrophobic MHR residues and restored by second-site suppressors, demonstrating that these MHR residues are required for the proper assembly of mature capsids in addition to any role that these amino acids may play in immature particle assembly. The defect caused by the MHR mutations was identified as an early step in the capsid assembly process. The results provide strong evidence for a model in which the hydrophobic residues of the MHR control a conformational reorganization of CA that is needed to initiate capsid assembly and suggest that the formation of an interdomain interaction occurs early during maturation.
Replication in a Superficial Epithelial Cell Niche Explains the Lack of Pathogenicity of Primate Foamy Virus Infections
Authors: Murray Shannon M. , Picker Louis J. , Axthelm Michael K. , Hudkins Kelly , Alpers Charles E. , Linial Maxine L.
Published: April 2008

Foamy viruses (FVs) are ancient retroviruses that are ubiquitous in nonhuman primates (NHPs). While FVs share many features with pathogenic retroviruses, such as human immunodeficiency virus, FV infections of their primate hosts have no apparent pathological consequences. Paradoxically, FV infections of many cell types in vitro are rapidly cytopathic. Previous work has shown that low levels of proviral DNA are found in most tissues of naturally infected rhesus macaques, but these proviruses are primarily latent. In contrast, viral RNA, indicative of viral replication, is restricted to tissues of the oral mucosa, where it is abundant. Here, we perform in situ hybridization on tissues from rhesus macaques naturally infected with simian FV (SFV). We show that superficial differentiated epithelial cells of the oral mucosa, many of which appear to be shedding from the tissue, are the major cell type in which SFV replicates. Thus, the innocuous nature of SFV infection can be explained by replication that is limited to differentiated superficial cells that are short-lived and shed into saliva. This finding can also explain the highly efficient transmission of FVs among NHPs.
Poly(rC) Binding Proteins and the 5′ Cloverleaf of Uncapped Poliovirus mRNA Function during De Novo Assembly of Polysomes
Authors: Kempf Brian J. , Barton David J.
Published: April 2008

Poliovirus (PV) mRNA is unusual because it possesses a 5′-terminal monophosphate rather than a 5′-terminal cap. Uncapped mRNAs are typically degraded by the 5′ exonuclease XRN1. A 5′-terminal cloverleaf RNA structure interacts with poly(rC) binding proteins (PCBPs) to protect uncapped PV mRNA from 5′ exonuclease (K. E. Murray, A. W. Roberts, and D. J. Barton, RNA 7:1126-1141, 2001). In this study, we examined de novo polysome formation using HeLa cell-free translation-replication reactions. PV mRNA formed polysomes coordinate with the time needed for ribosomes to traverse the viral open reading frame (ORF). Nascent PV polypeptides cofractionated with viral polysomes, while mature PV proteins were released from the polysomes. Alterations in the size of the PV ORF correlated with alterations in the size of polysomes with ribosomes present every 250 to 500 nucleotides of the ORF. Eukaryotic initiation factor 4GI (eIF4GI) was cleaved rapidly as viral polysomes assembled and the COOH-terminal portion of eIF4GI cofractionated with viral polysomes. Poly(A) binding protein, along with PCBP 1 and 2, also cofractionated with viral polysomes. A C24A mutation that inhibits PCBP-5′-terminal cloverleaf RNA interactions inhibited the formation and stability of nascent PV polysomes. Kinetic analyses indicated that the PCBP-5′ cloverleaf RNA interaction was necessary to protect PV mRNA from 5′ exonuclease immediately as ribosomes initially traversed the viral ORF, before viral proteins could alter translation factors within nascent polysomes or contribute to ribonucleoprotein complexes at the termini of the viral mRNA.
Ninety-Nine Is Not Enough: Molecular Characterization of Inhibitor-Resistant Human Immunodeficiency Virus Type 1 Protease Mutants with Insertions in the Flap Region
Authors: Kožíšek Milan , Šašková Klára Grantz , Řezáčová Pavlína , Brynda Jiří , van Maarseveen Noortje M. , De Jong Dorien , Boucher Charles A. , Kagan Ron M. , Nijhuis Monique , Konvalinka Jan
Published: April 2008

While the selection of amino acid insertions in human immunodeficiency virus (HIV) reverse transcriptase (RT) is a known mechanism of resistance against RT inhibitors, very few reports on the selection of insertions in the protease (PR) coding region have been published. It is still unclear whether these insertions impact protease inhibitor (PI) resistance and/or viral replication capacity. We show that the prevalence of insertions, especially between amino acids 30 to 41 of HIV type 1 (HIV-1) PR, has increased in recent years. We identified amino acid insertions at positions 33 and 35 of the PR of HIV-1-infected patients who had undergone prolonged treatment with PIs, and we characterized the contribution of these insertions to viral resistance. We prepared the corresponding mutated, recombinant PR variants with or without insertions at positions 33 and 35 and characterized them in terms of enzyme kinetics and crystal structures. We also engineered the corresponding recombinant viruses and analyzed the PR susceptibility and replication capacity by recombinant virus assay. Both in vitro methods confirmed that the amino acid insertions at positions 33 and 35 contribute to the viral resistance to most of the tested PIs. The structural analysis revealed local structural rearrangements in the flap region and in the substrate binding pockets. The enlargement of the PR substrate binding site together with impaired flap dynamics could account for the weaker inhibitor binding by the insertion mutants. Amino acid insertions in the vicinity of the binding cleft therefore represent a novel mechanism of HIV resistance development.
Definition of a Conserved Immunodominant Domain on Hepatitis C Virus E2 Glycoprotein by Neutralizing Human Monoclonal Antibodies
Authors: Keck Zhen-Yong , Li Ta-Kai , Xia Jinming , Gal-Tanamy Meital , Olson Oakley , Li Sophia H. , Patel Arvind H. , Ball Jonathan K. , Lemon Stanley M. , Foung Steven K. H.
Published: April 2008

Development of a successful hepatitis C virus (HCV) vaccine requires the definition of neutralization epitopes that are conserved among different HCV genotypes. Five human monoclonal antibodies (HMAbs) are described that cross-compete with other antibodies to a cluster of overlapping epitopes, previously designated domain B. Each HMAb broadly neutralizes retroviral pseudotype particles expressing HCV E1 and E2 glycoproteins, as well as the infectious chimeric genotype 1a and genotype 2a viruses. Alanine substitutions of residues within a region of E2 involved in binding to CD81 showed that critical E2 contact residues involved in the binding of representative antibodies are identical to those involved in the binding of E2 to CD81.
Functional and Structural Dynamics of Hepadnavirus Reverse Transcriptase during Protein-Primed Initiation of Reverse Transcription: Effects of Metal Ions
Authors: Lin Li , Wan Fen , Hu Jianming
Published: April 2008

Reverse transcription in hepadnaviruses is primed by the viral reverse transcriptase (RT) (protein priming) and requires the interaction between the RT and a specific viral RNA template termed ε. Protein priming is resistant to a number of RT inhibitors that can block subsequent viral DNA elongation and likely requires a distinct “priming” conformation. Furthermore, protein priming may consist of two distinct stages, i.e., the attachment of the first deoxynucleotide to RT (initiation) and the subsequent addition of 2 or 3 deoxynucleotides (polymerization). In particular, a truncated duck hepatitis B virus RT (MiniRT2) is competent in initiation but defective in polymerization when tested in the presence of Mg
2+
. Given the known effects of metal ions on the activities of various DNA and RNA polymerases, we tested if metal ions could affect hepadnavirus RT priming. We report here that Mn
2+
, in comparison with Mg
2+
, showed dramatic effects on the priming activity of MiniRT2 as well as the full-length RT. First and foremost, MiniRT2 exhibited full polymerization activity in the presence of Mn
2+
, indicating that MiniRT2 contains all sequences essential for polymerization but is unable to transition from initiation to polymerization with Mg
2+
. Second, the initiation activities of MiniRT2 and the full-length RT were much stronger with Mn
2+
. Third, the nucleotide and template specificities during protein priming were decreased in the presence of Mn
2+
. Fourth, polymerization was sensitive to inhibition by a pyrophosphate analog in the presence of Mn
2+
but not in the presence of Mg
2+
. Finally, limited proteolysis provided direct evidence that the priming active MiniRT2 adopted distinct conformations depending on the presence of Mn
2+
versus that of Mg
2+
and that the transition from initiation to polymerization was accompanied by RT conformational change.
Effective prevention of sports injuries: a model integrating efficacy, efficiency, compliance and risk-taking behaviour
Authors: Van Tiggelen D , Wickes S , Stevens V , Roosen P , Witvrouw E
Published: April 2008

In 1992 van Mechelenet alpublished a “sequence of prevention model” based on a four-step process. This model has been widely used to implement preventive measures in response to sports injuries. However, the execution of this model has been shown to lack validity in determining the success of a preventive measure. A modified model has therefore been proposed which incorporates additional steps that enable the inclusion of external factors with a significant effect on the outcome of a prevention intervention. This expansion of van Mechelen’s model leads to a more global model in which the compliance level and risk-taking behaviour of the individual and the assessment of efficiency of the stakeholders have a key influence on the preventive measure. This model gives a better insight into the different processes in injury prevention that can be used by clinicians, coaches and managers to decide whether to implement a preventive measure programme.
Drinking policies and exercise-associated hyponatraemia: is anyone still promoting overdrinking?
Authors: Beltrami F G , Hew-Butler T , Noakes T D
Published: April 2008

Objectives:

The purpose of this review is to describe the evolution of hydration research and advice on drinking during exercise from published scientific papers, books and non-scientific material (advertisements and magazine contents) and detail how erroneous advice is likely propagated throughout the global sports medicine community.

Design:

Hydration advice from sports-linked entities, the scientific community, exercise physiology textbooks and non-scientific sources was analysed historically and compared with the most recent scientific evidence.

Conclusions:

Drinking policies during exercise have changed substantially throughout history. Since the mid-1990s, however, there has been an increase in the promotion of overdrinking by athletes. While the scientific community is slowly moving away from “blanket” hydration advice in which one form of advice fits all and towards more modest, individualised, hydration guidelines in which thirst is recognised as the best physiological indicator of each subject’s fluid needs during exercise, marketing departments of the global sports drink industry continue to promote overdrinking.
Brick–mortar interface effects on masonry under compressionThis article is one of a selection of papers published in this Special Issue on Masonry.
Authors: Vermeltfoort A.T. , Martens D.R.W. , van Zijl G.P.A.G.
Published: April 2008

Masonry component products are increasingly made industrially with reduced variation in mechanical properties. The joint is the only part of the masonry that is affected by manual action and so the load bearing capacity is not only determined by the quality of the bricks and mortar used but moreover by the way the masonry has been built and cured. As a result, it may be expected that the largest material variations are at the brick–mortar interfaces. This has been observed as irregular interface bonding with a bonded central area surrounded by fissures. As a consequence of the final shape of the joint, forces concentrate in the central part of the joint and strain variations occur near fissure tips which result in spalling of bricks in experiments. This paper demonstrates the need for detailed deformational measurements in the brick–mortar interface region. To overcome the limitations with traditional measuring instruments, a refined methodology based on the laser speckle technique is introduced in a companion paper [Canadian Journal of Civil Engineering, 34(11), 1467 (2007)] by the authors of this paper.
Sprayed glass fibre reinforced polymer masonry columns under concentric and eccentric loadingThis article is one of a selection of papers published in this Special Issue on Masonry.
Authors: Shaheen E. , Shrive N. G.
Published: April 2008

Strengthening masonry columns by spraying them with glass fibre reinforced polymer (GFRP) was investigated experimentally. The study was aimed at assessing the strength and strain increases imparted by the technique under both concentric and eccentric axial loading. Plain and steel-reinforced columns were tested. Twenty-four columns were constructed from Type S mortar and straight and bullnose clay masonry units. The columns were 1 m high and either 290 mm × 290 mm or 390 mm × 390 mm in cross section. Two thicknesses of sprayed GFRP (SGFRP) were attempted, but it was found to be difficult to maintain uniform thickness. Nevertheless, with only minor increases in strength, large increases in strain capacity were achieved with both the plain and reinforced columns under concentric axial compression. Eccentric loading reduced the effect of the SGFRP laminate on the strength of masonry columns. Failure of SGFRP included both mode I and mode III fractures.
Electronic speckle pattern interferometry observation of brick–mortar interface behaviour under compressionThis article is one of a selection of papers published in this Special Issue on Masonry.
Authors: Vermeltfoort A.T. , Martens D.R.W. , van Zijl G.P.A.G.
Published: April 2008

The brick–mortar interaction is important in the mechanical behaviour of masonry. It affects the load transfer considerably, as shown by detailed deformation measurements taken using electronic speckle pattern interferometry (ESPI), a laser speckle interference technique. A companion paper [Canadian Journal of Civil Engineering, 34(11), 1475 (2007)] by the authors of this paper argues that the joint is the only part of contemporary masonry significantly affected by manual action, which is why large material variations appear at the brick–mortar interface. To evaluate this phenomenon, ESPI measurements were performed and compared with accompanying linear variable differential transformer (LVDT) results. The behaviour of specimens loaded with various eccentricities was relatively soft in the brick–mortar interface area when compared with the behaviour shown in the surrounding stiff brick and mortar. The brick–mortar interface was characterized by a central part surrounded by fissures. Most of the load was transmitted in the central part. Because of this, the axial strain curve over the width of the specimens was U-shaped for concentrically loaded specimens (i.e., those with zero eccentricity). Over the height of the two-brick one-joint specimen, a smooth, B-shaped lateral strain curve was observed, in which the largest strains were found in the bricks.
Dry-cast concrete masonry products: properties and durabilityThis article is one of a selection of papers published in this Special Issue on Masonry.
Authors: Chidiac S. E. , Zibara H.
Published: April 2008

Performance of dry-cast concrete masonry products (DCCMPs), which are becoming the product of choice for many applications, has yet to be assessed in a comprehensive manner. This study was undertaken to investigate the effects of mix design and manufacturing parameters on the mechanical and transport properties, as well as the freeze–thaw (F/T) durabilities, of DCCMPs. The variables studied were water to cement ratio, mixing time, vibration time, and curing regime. Freeze–thaw durability was assessed in accordance with the American Society for Testing and Materials (ASTM) standard C1262 by exposing specimens to four conditions: water, 3% NaCl, 4% CaCl2, and 4% MgCl2 solutions. Results revealed that 3% NaCl exposure yielded the most mass loss due to scaling, whereas 4% MgCl2 exposure exhibited the least. Increase in either water content, vibration time, mixing time, or use of moist curing led to improvement in the mechanical properties, refinement of large pores in the range of 40 to 400 μm, reduction of total porosity, and enhancement of F/T durability of capstones. Ionic sorptivity yielded a strong statistical correlation with mass loss due to F/T action in the presence of 3% NaCl and 4% CaCl2.
Innovative seismic design of a post-tensioned concrete masonry houseThis article is one of a selection of papers published in this Special Issue on Masonry.
Authors: Wight Gavin D. , Ingham Jason M. , Wilton Andrew R.
Published: April 2008

Post-tensioned concrete masonry walls provide improved seismic performance, but have had limited application in seismic regions because of a lack of research pertaining to their in-plane response. Following focused research over recent years, a consortium of product suppliers has collaborated with the University of Auckland to construct New Zealand’s first post-tensioned concrete masonry house. A feature of this innovative design was that all incorporated products were commercially available, with no proprietary products being specifically developed for the prestressed masonry system used. Consequently, it is hoped that this house will be a showcase, and provide exposure for the technology in New Zealand and elsewhere. This paper provides a brief review of previous post-tensioned concrete masonry research applications, then discusses post-tensioning details and their application to house design and construction.
BASIC ALGORITHM FOR ATTRIBUTE IMPLICATIONS AND FUNCTIONAL DEPENDENCIES IN GRADED SETTING
Authors: BĚLOHLÁVEK RADIM , VYCHODIL VILEM
Published: April 2008

We present GLINCLOSURE, a graded extension of the well-known LINCLOSURE algorithm. GLINCLOSURE can be used to compute degrees of semantic entailment from sets of fuzzy attribute implications. It can also be used together with graded extension of Ganter's NEXTCLOSURE algorithm to compute non-redundant bases of data tables with fuzzy attributes. We present foundations, the algorithm, analysis of its complexity, implementation details, and illustrative examples.