Linguistics

Contains reports on four research projects.U. S. Air Force (Electronics Systems Division) under Contract AF 19(628)-2487Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)National Science Foundation (Grant GK-835)National Institutes of Health (Grant 2 PO1 MH-04737-06)National Aeronautics and Space Administration (Grant NsG-496

Effectiveness of implant-supported fixed partial denture in patients with history of periodontitis: A systematic review and meta-analysis

Aim: This systematic review investigates the effectiveness of implant-supported fixed partial denture (IS-FPD) in patients with history of periodontitis (HP) vs. patients with no history of periodontitis (NHP). Methods: A literature search was performed on different databases on May 2020. Prospective and retrospective studies assessing survival (primary outcome), success and biological/mechanical complications of IS-FPDs in HP vs. NHP patients at ≥1 year after implant loading were evaluated. Meta-analyses were conducted by estimating hazard ratio (HR), risk ratio (RR) and standardized mean differences (SMD) with 95% confidence intervals (CI) using random effect models. Results: Of the initially identified 4096 articles, 349 underwent a full-text evaluation. Finally, 17 were included. Pooled data analyses showed that overall implant survival was significantly higher in the NHP than the HP group (HR = 2.06; 95% CI = 1.37–3.09; I2 = 0%). This difference was noted when follow-up ≥5 years. The risk of peri-implantitis was higher in HP than NHP patients (RR = 3.3; 95% CI = 1.31–8.3; I2 = 0%), whereas the mean marginal bone level change over time was not different between the groups (SMD = −0.16 mm; 95% CI = −1.04–0.73; I2 = 98%). Conclusions: In partially edentulous patients receiving IS-FPDs, a history of periodontitis is associated with poorer survival rate and higher risk of peri-implantitis during a 5–10 years period after implant loading

Arcobacter Species in Humans1

During an 8-year study period, Arcobacter butzleri was the fourth most common Campylobacter-like organism isolated from 67,599 stool specimens. Our observations suggest that A. butzleri displays microbiologic and clinical features similar to those of Campylobacter jejuni; however, A. butzleri is more frequently associated with a persistent, watery diarrhea

Burkholderia anthina sp. nov. and Burkholderia pyrrocinia , two additional Burkholderia cepacia complex bacteria, may confound results of new molecular diagnostic tools

Nineteen Burkholderia cepacia -like isolates of human and environmental origin could not be assigned to one of the seven currently established genomovars using recently developed molecular diagnostic tools for B. cepacia complex bacteria. Various genotypic and phenotypic characteristics were examined. The results of this polyphasic study allowed classification of the 19 isolates as an eighth B. cepacia complex genomovar ( Burkholderia anthina sp. nov.) and to design tools for its identification in the diagnostic laboratory. In addition, new and published data for Burkholderia pyrrocinia indicated that this soil bacterium is also a member of the B. cepacia complex. This highlights another potential source for diagnostic problems with B. cepacia -like bacteria.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71564/1/j.1574-695X.2002.tb00584.x.pd

Analytical expressions for the conductance noise measured with four circular contacts placed in a square array

In the ideal case, noise measurements with four contacts minimize the contribution of the contact interface. There is a need to characterize conductance noise and noise correction factors for the different geometries provided with four contacts, as already is the case for resistivity measurements with van der Pauw structures. Here, we calculate the noise correction factors for two geometries with a pair of sensors and a pair of current driver electrodes placed in a square array. The first geometry investigated is a very large film compared to the distance L between four circular electrodes, which are placed in a square array far away from the borders of the film. The second is a square-shaped conductive film with side length L and provided with four quarter-circle corner contacts with radius l. The effect of the conductance noise in the film can be observed between current free sensors in a four-point measurement or between current carrying drivers in a two-point measurement. Our analytical expressions are based on approximations to solve the integrals (J·)2dA and |J|4dA for the voltage noise measured across a pair of sensors, SVQ, and across the drivers, SVD, respectively. The first and second integrands represent the squared dot product of the current density and adjoint current density and the modulus of the current density to the fourth power, respectively. The current density J in the samples is due to the current I passing through the driver contacts. The calculated expressions are applicable to samples with thickness tl0.1L. Hence, the disturbances in the neighborhood of the sensors on J and of the drivers on are ignored. Noise correction factors for two- and four-point measurements are calculated for sensors on an equipotential (transversal noise) with the driver contacts on the diagonal of a square and for sensors next to each other on one side of the square with the drivers next to each other on the other side of the square (longitudinal noise). In all cases the noise between the sensors is smaller and less sensitive to the contact size 2l/L than the noise between the drivers. The ratio SVQ/SVD becomes smaller with smaller contact radius l. Smaller sensors give a better suppression of interface noise at the contacts. But overly low 2l/L values result in overly high resistance between the sensors and too strong a contribution of thermal noise at the sensors. Therefore, equations are derived to calculate the current level needed to observe 1/f conductance fluctuations on top of the thermal noise. The results from the calculated analytical expressions show good agreement with experimental results obtained from the noise in carbon sheet resistance and numerical results. Transversal noise measurements on a square sample with corner contacts are recommended to characterize the 1/f noise of the layer. This is due to the increased current densities in the sample compared to the open structure, which result in easier detection of the 1/f on top of the thermal noise. ©2007 American Institute of Physic

Mechanical competence of ovariectomy-induced compromised bone after single or combined treatment with high-frequency loading and bisphosphonates

Osteoporosis leads to increased bone fragility, thus effective approaches enhancing bone strength are needed. Hence, this study investigated the effect of single or combined application of high-frequency (HF) loading through whole body vibration (WBV) and alendronate (ALN) on the mechanical competence of ovariectomy-induced osteoporotic bone. Thirty-four female Wistar rats were ovariectomized (OVX) or sham-operated (shOVX) and divided into five groups: shOVX, OVX-shWBV, OVX-WBV, ALN-shWBV and ALN-WBV. (Sham)WBV loading was applied for 10 min/day (130 to 150 Hz at 0.3g) for 14 days and ALN at 2 mg/kg/dose was administered 3x/week. Finite element analysis based on micro-CT was employed to assess bone biomechanical properties, relative to bone micro-structural parameters. HF loading application to OVX resulted in an enlarged cortex, but it was not able to improve the biomechanical properties. ALN prevented trabecular bone deterioration and increased bone stiffness and bone strength of OVX bone. Finally, the combination of ALN with HF resulted in an increased cortical thickness in OVX rats when compared to single treatments. Compared to HF loading, ALN treatment is preferred for improving the compromised mechanical competence of OVX bone. In addition, the association of ALN with HF loading results in an additive effect on the cortical thickness

Factors influencing adherence to antiretroviral therapy among people living with HIV in an urban and rural setting, Tanzania

Adherence is one of the most crucial determinants of treatment response to antiretroviral therapy (ART). An analytical cross-sectional study was conducted in 24 Care and Treatment Centres (CTC) in Dar es Salaam and Iringa regions in Tanzania. Data was collected using questionnaire and appointments records. A total of 943 patients attending at the care and treatment sites in Dar es Salaam and Iringa were recruited. Adherence based on keeping appointments and on four days recall was 65% and 70%, respectively. Adherence based on taking ART more than 95% of the time in one month was 83%. Satisfaction with health services, having treatment support, having knowledge on the use of ART, early presentation to CTC, and being on ART for more than one year, were associated with good adherence. Being in the urban region, using traditional medicine, medicine side effects and alcohol consumption problems negatively associated with adherence to ART.Keywords: Adherence barriers, antiretroviral therapy, HIV, Tanzania, rural, urba

CHARACTERIZATION OF F107 FIMBRIAE OF ESCHERICHIA-COLI 107/86, WHICH CAUSES EDEMA DISEASE IN PIGS, AND NUCLEOTIDE-SEQUENCE OF THE F107 MAJOR FIMBRIAL SUBUNIT GENE, FEDA

F107 fimbriae were isolated and purified from edema disease strain 107/86 of Escherichia coli. Plasmid pIH120 was constructed, which contains the gene cluster that codes for adhesive F107 fimbriae. The major fimbrial subunit gene, fedA, was sequenced. An open reading frame that codes for a protein with 170 amino acids, including a 21-amino-acid signal peptide, was found. The protein without the signal sequence has a calculated molecular mass of 15,099 Da. Construction of a nonsense mutation in the open reading frame of fedA abolished both fimbrial expression and the capacity to adhere to isolated porcine intestinal villi. In a screening of 28 reference edema disease strains and isolates from clinically ill piglets, fedA was detected in 24 cases (85.7%). In 20 (83.3%) of these 24 strains, fedA was found in association with Shiga-like toxin II variant genes, coding for the toxin that is characteristic for edema disease strains of E. coli. The fimbrial subunit gene was not detected in enterotoxigenic E. coli strains. Because of the capacity of E. coli HB101(pIH120) transformants to adhere to isolated porcine intestinal villi, the high prevalence of fedA in edema disease strains, and the high correlation with the Shiga-like toxin II variant toxin-encoding genes, we suggest that F107 fimbriae are an important virulence factor in edema disease strains of E. coli