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Unraveling How Candida albicans Forms Sexual Biofilms.
Biofilms, structured and densely packed communities of microbial cells attached to surfaces, are considered to be the natural growth state for a vast majority of microorganisms. The ability to form biofilms is an important virulence factor for most pathogens, including the opportunistic human fungal pathogen Candida albicans. C. albicans is one of the most prevalent fungal species of the human microbiota that asymptomatically colonizes healthy individuals. However, C. albicans can also cause severe and life-threatening infections when host conditions permit (e.g., through alterations in the host immune system, pH, and resident microbiota). Like many other pathogens, this ability to cause infections depends, in part, on the ability to form biofilms. Once formed, C. albicans biofilms are often resistant to antifungal agents and the host immune response, and can act as reservoirs to maintain persistent infections as well as to seed new infections in a host. The majority of C. albicans clinical isolates are heterozygous (a/α) at the mating type-like (MTL) locus, which defines Candida mating types, and are capable of forming robust biofilms when cultured in vitro. These "conventional" biofilms, formed by MTL-heterozygous (a/α) cells, have been the primary focus of C. albicans biofilm research to date. Recent work in the field, however, has uncovered novel mechanisms through which biofilms are generated by C. albicans cells that are homozygous or hemizygous (a/a, a/Δ, α/α, or α/Δ) at the MTL locus. In these studies, the addition of pheromones of the opposite mating type can induce the formation of specialized "sexual" biofilms, either through the addition of synthetic peptide pheromones to the culture, or in response to co-culturing of cells of the opposite mating types. Although sexual biofilms are generally less robust than conventional biofilms, they could serve as a protective niche to support genetic exchange between mating-competent cells, and thus may represent an adaptive mechanism to increase population diversity in dynamic environments. Although conventional and sexual biofilms appear functionally distinct, both types of biofilms are structurally similar, containing yeast, pseudohyphal, and hyphal cells surrounded by an extracellular matrix. Despite their structural similarities, conventional and sexual biofilms appear to be governed by distinct transcriptional networks and signaling pathways, suggesting that they may be adapted for, and responsive to, distinct environmental conditions. Here we review sexual biofilms and compare and contrast them to conventional biofilms of C. albicans
Arthroscopic transosseous rotator cuff repair: A prospective study on cost savings, surgical time, and outcomes
Objectives: Health expenditures in the United States are outpacing national income, and affordability has become a major policy issue. Over 500,000 rotator cuff repairs (RCR) are performed annually in the United States making RCR a potential source of cost savings. Arthroscopic trans-osseous equivalent (TOE) repair using a double row of anchors has shown superior biomechanical strength compared to other techniques, but at a higher cost. The arthroscopic transosseous (TO) repair is a novel technique allowing arthroscopic rotator cuff repair to be performed without suture anchors. Arthroscopic TO repair may be a means to provide similarly excellent patient outcomes while lowering the cost of care. The primary purpose is to compare the price differential and time of surgery for an arthroscopic rotator cuff repair using anchorless TO repair verses an anchor trans-osseous equivalent (TOE) repair. A secondary purpose of the study was to evaluate outcomes at 6 months postoperatively. Methods: A prospective, case-controlled study evaluating arthroscopic rotator cuff repair using two techniques was performed. The study group consisting of 21 patients undergoing TO repair was compared to a control group consisting of 22 patients undergoing TOE repair. The groups were controlled for size of tear, biceps treatment, acromioplasty, distal clavicle excision, and labral pathology. The primary outcome measures were surgical time as well as total cost of implants and equipment for each surgery, determined by an independent third party, Atlanticare Hospital. Secondary outcomes were changes in the SST, VAS, and SANE scores. Results: Mean total surgical implant/equipment cost per procedure for TOE repair was 1204.97 (SD 330.69; p\u3c0.0001). Mean cut to close time for TOE repair was 85 minutes (95% CI is 77-90) verses 74 (95% CI = 71-98) for TO repair. A log rank test revealed no difference in time (p =0.95). A linear regression model was developed to evaluate the change in SST, VAS, and SANE scores from pre-op to 6 months follow-up. Our study was underpowered but no difference in outcome was observed. Conclusion: Arthroscopic TO rotator cuff repair is a cost savings and time neutral technique compared to TOE repair. A mean of $1100 can be saved in surgical cost per case. In a country that performs over 500,000 RCRs annually, utilizing a TO repair technique can provide substantial cost savings to the healthcare system. © The Author(s) 2015
Quantum Error Correction on Linear Nearest Neighbor Qubit Arrays
A minimal depth quantum circuit implementing 5-qubit quantum error correction
in a manner optimized for a linear nearest neighbor architecture is described.
The canonical decomposition is used to construct fast and simple gates that
incorporate the necessary swap operations. Simulations of the circuit's
performance when subjected to discrete and continuous errors are presented. The
relationship between the error rate of a physical qubit and that of a logical
qubit is investigated with emphasis on determining the concatenated error
correction threshold.Comment: 4 pages, 5 figure
A BAYESIAN APPROACH TO ASSESSING LAB PROFICENCY WITH QUALITATIVE PCR ASSAYS USED TO DETECT BIOTECH TRAITS IN CROP SEED
Many seed testing laboratories currently use polymerase chain reaction (PCR) assays to test conventional crop seed for the adventitous presence of biotech trait seed. Seed organizations and companies are spending much time and resources assessing laboratories proficency in running PCR assays. Since many of these assays provide qualitative rather than quantitative results, laboratories must go through a significant effort to obtain adequate assay error estimates. Many sample-processing steps are very similar from assay to assay and therefore error results from different assays may be combined using a Bayesian approach to obtain estimates of assay error rates with increased precision. This paper introduces a relatively simple Bayesian approach that can be used to combine data from a present assay of interest with prior lab data on related assays to obtain updated estimates of assay error rates. If this approach is successfully implemented it can yield as much as a ten-fold reduction in required testing resources
A BAYESIAN APPROACH TO ASSESSING LAB PROFICENCY WITH QUALITATIVE PCR ASSAYS USED TO DETECT BIOTECH TRAITS IN CROP SEED
Many seed testing laboratories currently use polymerase chain reaction (PCR) assays to test conventional crop seed for the adventitous presence of biotech trait seed. Seed organizations and companies are spending much time and resources assessing laboratories proficency in running PCR assays. Since many of these assays provide qualitative rather than quantitative results, laboratories must go through a significant effort to obtain adequate assay error estimates. Many sample-processing steps are very similar from assay to assay and therefore error results from different assays may be combined using a Bayesian approach to obtain estimates of assay error rates with increased precision. This paper introduces a relatively simple Bayesian approach that can be used to combine data from a present assay of interest with prior lab data on related assays to obtain updated estimates of assay error rates. If this approach is successfully implemented it can yield as much as a ten-fold reduction in required testing resources
Recovery-informed Theory: Situating the Subjective in the Science of Substance Use Disorder Recovery
As recovery from substance use disorder becomes more than a mere quantifiable outcome, there exists a need to discuss and propose the underlying theoretical constructs that ultimately describe and identify the science of recovery. In this abstract undertaking, we propose an initial formulation of a grand theory of recovery science, built upon the seminal theories of recovery capital, recovery-oriented systems of care, and socioecological theory. This grand theory - labeled recovery-informed theory (RIT) - states that successful long-term recovery is self-evident and is a fundamentally emancipatory set of processes. This paper will discuss, analyze, and explore this theory as it is situated within the larger substance use, misuse, and disorder contexts. The uses, implications, and benefits of RIT as an organizing point of inquiry for recovery science are also discussed. By promoting the role of subjective recovery experience in the formulation of the study of recovery, it may be possible to summon new ideas, metrics, and strategies that can directly address substance use disorders in society. Adopting a recovery-informed understanding as follows from this grand theory may allow individual recovery and wellness trajectories to be explored, adapted, and modified to exemplify person-centered and individualized recovery strategies
Optical mode size control by MgO indiffusion in Ti:LiNbO3 waveguides
In this paper, the use of magnesium oxide (MgO) indiffusion in combination with Ti:LiNbO<sub>3</sub> through appropriate control of pre- and post-diffusion parameters is investigated as a way of controlling optical mode size. The co-diffusion of pre-patterned Ti with various patterned MgO films on LiNbO<sub>3</sub> has been compared experimentally. This method has been applied to study straight waveguides and couplers. The waveguides were optically characterized by near-field mode size and loss measurements methods at a wavelength of 1.55 μm. Reduction of inter-mode coupling between adjacent waveguides with the introduction of MgO has been observed
Absorption of Energy at a Metallic Surface due to a Normal Electric Field
The effect of an oscillating electric field normal to a metallic surface may
be described by an effective potential. This induced potential is calculated
using semiclassical variants of the random phase approximation (RPA). Results
are obtained for both ballistic and diffusive electron motion, and for two and
three dimensional systems. The potential induced within the surface causes
absorption of energy. The results are applied to the absorption of radiation by
small metal spheres and discs. They improve upon an earlier treatment which
used the Thomas-Fermi approximation for the effective potential.Comment: 19 pages (Plain TeX), 2 figures, 1 table (Postscript
Prevention of ulcer disease in goldfish by means of vaccination
A vaccine comprising cells of Aeromonas bestiarum grown in tryptic soy broth and atypical A. salmonicida cells produced in iron-limited and iron-supplemented media protected goldfish Carassius auratus when administered by immersion (dosage ≈ 5 × 107 cells/mL for 60 s) followed after 28 d by an oral booster (dosage = 5 × 107 cells/g of feed), which was fed for 7 d so that each fish received about 1 g of vaccine-containing feed. After challenge by intramuscular injection of a virulent culture of atypical A. salmonicida, the relative percent survival (RPS) was more than 90%. The approach was more successful than using a commercial furunculosis vaccine with or without supplementation with A. bestiarum or atypical A. salmonicida cells. Moreover, a smooth derivative of the virulent rough culture of atypical A. salmonicida was less effective as a vaccine candidate, yielding an RPS of only 65%. Low antibody titers of 1:39–1:396 were found in the vaccinated fish. The vaccinated fish had a significantly higher proportion of dead head kidney macrophages (10.9 ± 3.5%; P = 0.0149) than did the controls (6.8 ± 3.1%). However, differences in the number of erythrocytes and leukocytes, the level of phagocytic and lysozyme activities, and the proportion of lymphocytes, monocytes, and polymorphonuclear cells were not statistically significant between the two groups
Elemental bio-imaging of trace elements in teeth using laser ablation-inductively coupled plasma-mass spectrometry
Objectives: In this study we present the application of a novel laboratory method that employs laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to construct two-dimensional maps of trace elements in teeth. Methods: Teeth were sectioned longitudinally, embedded in resin and polished to a smooth surface. Data were generated by laser ablating the entire sectioned tooth surface. Elemental images were constructed using custom-built software. Results: Quantified images of 66Zn, 88Sr, 111Cd and 208Pb, with a spatial resolution of 30 μm2, were generated from three teeth. Concentrations were determined by single-point calibration against NIST SRM 1486 (bone meal). Zn and Sr concentrations were determined in the μg g-1 range and Cd and Pb in the ng g -1 range. Concentrations of Pb, Zn and Cd were higher in dentine particularly in regions adjacent the pulp. Conclusions: Elemental bio-imaging employing LA-ICP-MS is a novel method for constructing μm-scale maps of trace elements in teeth. This simple imaging method displays the heterogeneity of trace elements throughout the tooth structure that correspond to specific structural and developmental features of teeth. As a preliminary study, this work demonstrates the capabilities of LA-ICP-MS imaging in dental research. © 2011 Elsevier Ltd. All rights reserved
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