Comparison of plane mirror vs retroreflector performance for laser-self-mixing displacement sensors

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A PLAC8-containing protein from an endomycorrhizal fungus confers cadmium resistance to yeast cells by interacting with Mlh3p

Cadmium is a genotoxic pollutant known to target proteins that are involved in DNA repair and in antioxidant defence, altering their functions and ultimately causing mutagenic and carcinogenic effects. We have identified a PLAC8 domain-containing protein, named OmFCR, by a yeast functional screen aimed at identifying genes involved in cadmium resistance in the endomycorrhizal fungus Oidiodendron maius. OmFCR shows a remarkable specificity in mediating cadmium resistance. Both its function and its nuclear localization in yeast strictly depend on the interaction with Mlh3p, a subunit of the mismatch repair (MMR) system. Although proteins belonging to the PLAC8 family are widespread in eukaryotes, they are poorly characterized and their biological role still remains elusive. Our work represents the first report about the potential role of a PLAC8 protein in physically coupling DNA lesion recognition by the MMR system to appropriate effectors that affect cell cycle checkpoint pathways. On the basis of cell survival assays and yeast growth curves, we hypothesize that, upon cadmium exposure, OmFCR might promote a higher rate of cell division as compared to control cells

Ageing exacerbates damage of systemic and salivary neutrophils from patients presenting Candida-related denture stomatitis

<p>Abstract</p> <p>Background</p> <p>Ageing leads to a decline in the function of the immune system, increasing the body's susceptibility to infections through the impairment of T-cells, macrophages, neutrophils and dendritic cells Denture stomatitis is a primary oral disease affecting elderly denture wearers. The major etiologic factor involved in this pathology is the infection by <it>Candida albicans</it>, an opportunistic pathogen that causes local and disseminated diseases in immunosuppressed humans. Neutrophils play a critical role in the immune response against <it>C. albicans </it>and are continually present in the salivary fluid and in the blood. The aim of this study was to determine ageing-related changes in salivary and blood neutrophils and their potential implications in <it>Candida</it>-related denture stomatitis.</p> <p>Results</p> <p>Our results showed a lower number of neutrophils in the saliva from patients presenting <it>Candida</it>-related denture stomatitis in comparison to their matched controls. Furthermore, fewer neutrophils were isolated from the saliva of aged control individuals in comparison to matched younger subjects. CXCR1, CD62L and CD11b expression were significantly greater on systemic neutrophils from younger control individuals. Elderly individuals showed more apoptotic salivary neutrophils and lower GM-CSF levels than younger ones, regardless of the occurrence of <it>Candida </it>infection. On the other hand, CXCL-8 concentrations were higher in the saliva from elderly individuals. Besides, TNF-α was detected at elevated levels in the saliva from infected elderly subjects. Salivary neutrophils from elderly and young patients presented impaired phagocytic activity against <it>C. albicans</it>. However, just systemic neutrophils from elderly showed decreased phagocytosis when compared to the younger ones, regardless of the occurrence of infection. In addition, neutrophils from aged individuals and young patients presented low fungicidal activity.</p> <p>Conclusion</p> <p>The data suggests that the <it>Candida </it>related-denture stomatitis is associated to neutrophils function deficiency, and ageing drastically appears to alter important characteristics of such cells, facilitating the establishment of this infection.</p

A NEW THREE DEGREES-OF-FREEDOM MOTION SENSOR BASED ON LASER SELF-MIXING WITH PIGTAILED SOURCES

Real time simultaneous measurement by remote laser source of long range longitudinal displacement and small angle wobbling of a sliding target is demonstrated. The compact self-aligned laser-self-mixing interferometer achieves 0.8 µm axial resolution over 1 m linear and 17 µrad of pitch and yaw resolution over 2 mrad angular ranges, respectively

Comparison of plane mirror vs retroreflector performance for laser-self-mixing displacement sensors

The behavior of a displacement optical sensor based on the Laser-Self-Mixing effect employing a plane mirror (PT) and a solid corner-cube (CC) as moving target is analyzed. The performance of the sensor is compared in terms of simplification of the optical setup, measurement accuracy and tolerance to angular misalignment of the target. On the basis of the innovative assumption that only the fraction of the laser beam orthogonal to the target plane gives rise to the Self – Mixing modulation, it is demonstrated that the interferometer tolerates small tilt of the plane target (up to approximately 0.7◦) only when illuminated by a divergent beam, in which case the displacement measurement becomes affected by a cosine – type error. Instead the corner cube preserves the self-mixing signal over a larger angular range (up to approximately 2◦) at the same time preserving high measurement accuracy

Laser-Self-Mixing Interferometry for Mechatronics Applications

We report on the development of an all-interferometric optomechatronic sensor for the detection of multi-degrees-of-freedom displacements of a remote target. The prototype system exploits the self-mixing technique and consists only of a laser head, equipped with six laser sources, and a suitably designed reflective target. The feasibility of the system was validated experimentally for both single or multi-degrees-of-freedom measurements, thus demonstrating a simple and inexpensive alternative to costly and bulky existing systems