An ultra stable optical bench for the magnetic survey satellite

NASA Technical Reports Server (NTRS)

Wingate, C. A., Jr.; Coughlin, T. B.; Sullivan, R. M.

1978-01-01

The Magsat optical bench has been designed and built to hold the alignment of five optical elements to deflections of 1-2 arcsec during orbital operation. The bench has been designed to withstand alignment changes during the launch and prestabilization phases of the mission. Severe weight constraints, in conjunction with the thermal and structural requirements, led to the choice of graphite-fiber-reinforced epoxy egg crate core and face sheets for the bench construction. Active temperature control was necessary to meet thermal deflection objectives, and novel kinematic mountings were required to prevent spacecraft bending from deflecting the bench.

Lens-free imaging-based low-cost microsensor for in-line wear debris detection in lube oils

NASA Astrophysics Data System (ADS)

Mabe, Jon; Zubia, Joseba; Gorritxategi, Eneko

2017-02-01

The current paper describes the application of lens-free imaging principles for the detection and classification of wear debris in lubricant oils. The potential benefits brought by the lens-free microscopy techniques in terms of resolution, deep of field and active areas have been tailored to develop a micro sensor for the in-line monitoring of wear debris in oils used in lubricated or hydraulic machines as gearboxes, actuators, engines, etc. The current work presents a laboratory test-bench used for evaluating the optical performance of the lens-free approach applied to the wear particle detection in oil samples. Additionally, the current prototype sensor is presented, which integrates a LED light source, CMOS imager, embedded CPU, the measurement cell and the appropriate optical components for setting up the lens-free system. The imaging performance is quantified using micro structured samples, as well as by imaging real used lubricant oils. Probing a large volume with a decent 2D spatial resolution, this lens-free micro sensor can provide a powerful tool at very low cost for inline wear debris monitoring.

Optical Bench for LISA-like missions

NASA Astrophysics Data System (ADS)

Mueller, Guido

The detection of B-modes in the μ-Wave background has rattled the scientific community and further enhanced the large scientific interest in gravitational waves and gravitational wave astronomy. The first direct detection of gravitational waves by Advanced LIGO and maybe also by pulsar timing arrays in the second half of this decade will be another watershed event which will start a new era in astronomy and astrophysics. However, the holy grail of gravitational wave astronomy will be opened by a LISA-like mission. Only space provides the environment that allows to cover the signal-rich mHz frequency range where we expect to see gravitational waves from massive black hole mergers, compact galactic binaries, and many other sources. All mature concepts use laser interferometry between free falling test masses separated by millions of km. The central piece in all these concepts is a stable optical bench which is used to prepare and exchange the laser beams between the different arms. It has always been assumed that the base material for the optical bench has to be one of the ultra-low expansion glasses such as Zerodur or ULE to meet the pm/#Hz stability requirements. This very conservative approach was a reflection of the state-of-the-art in frequency stabilization experiments which used optical reference cavities in the early ‘90s. It is not surprising that the LISA pathfinder (LPF) uses also an all Zerodur bench where each optical component is precision bonded to the bench using hydroxide bonding, a nonreversible bonding technique. The manufacturing of this bench was a very time consuming one-mirror-a-day effort and was one of the highest risk items in terms of schedule and cost. The original LISA design uses the same approach except that the LISA bench is far more complex than the LPF bench and manufacturing of the required 10+ benches, six flight units and at least four pre-flight models and spares, will be even more time consuming and expensive. We question the need for ultra-low expansion glass for the optical bench. We will streamline the design of the bench and explore other materials and assembly techniques to significantly simplify the manufacturing process. Why are we confident that this is possible? One argument is that in early LISA designs the reference cavity was also part of the bench. This cavity drove the requirements to 30 fm/#Hz, a factor 30 more stringent compared to the current requirements. Since the cavity has now been removed from the bench, the requirements have been relaxed. A second argument is that we demonstrated pm/#Hz performance for a number of different materials and structures which are all candidate materials for the telescopes which also have to meet the same requirements over actually a larger distance. Our objective is to take a fresh look at the optical bench. We will redesign core parts of the interferometer bench with a focus on reducing the number and lengths of critical paths and moving non-critical parts away from the core part of the bench and sometimes even into optical fibers. We also propose to use different materials and assembly techniques for the optical bench and strongly believe that they will still meet the pm/#Hz requirement and will also be stable on long time scales. This confidence is based on nearly ten years of experience during which we investigated different materials and structures for the telescopes which we plan to apply now to the optical bench.

Efficient optical cloud removal technique for earth observation based on MOEMs device

NASA Astrophysics Data System (ADS)

Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Noell, Wilfried

2017-11-01

In Earth Observation instruments, observation of scenes including bright sources leads to an important degradation of the recorded signal. We propose a new concept to remove dynamically the bright sources and then obtain a field of view with an optically enhanced Signal-to-Noise Ratio (SNR). Micro-Opto-Electro-Mechanical Systems (MOEMS) could be key components in future generation of space instruments. MOEMS-based programmable slit masks will permit the straylight control in future Earth Observation instruments. Experimental demonstration of this concept has been conducted on a dedicated bench. This successful first demonstration shows the high potential of this new concept in future spectro-imager for Earth Observation.

Evacuated optical structure comprising optical bench mounted to sidewall of vacuum chamber in a manner which inhibits deflection and rotation of the optical bench

DOEpatents

Bowers, Joel M.

1994-01-01

An improved evacuated optical structure is disclosed comprising an optical bench mounted in a vacuum vessel in a manner which inhibits transmission of movement of the vacuum vessel to the optical bench, yet provides a compact and economical structure. The vacuum vessel is mounted, through a sidewall thereof, to a support wall at four symmetrically positioned and spaced apart areas, each of which comprises a symmetrically positioned group of mounting structures passing through the sidewall of the vacuum vessel. The optical bench is pivotally secured to the vacuum vessel by four symmetrically spaced apart bolts and spherical bearings, each of which is centrally positioned within one of the four symmetrically positioned groups of vacuum vessel mounting structures. Cover plates and o-ring seals are further provided to seal the vacuum vessel mounting structures from the interior of the vacuum vessel, and venting bores are provided to vent trapped gases in the bores used to secure the cover plates and o-rings to the vacuum vessel. Provision for detecting leaks in the mounting structures from the rear surface of the vacuum vessel sidewall facing the support wall are also provided. Deflection to the optical bench within the vacuum vessel is further minimized by tuning the structure for a resonant frequency of at least 100 Hertz.

Evacuated optical structure comprising optical bench mounted to sidewall of vacuum chamber in a manner which inhibits deflection and rotation of the optical bench

DOEpatents

Bowers, J.M.

1994-04-19

An improved evacuated optical structure is disclosed comprising an optical bench mounted in a vacuum vessel in a manner which inhibits transmission of movement of the vacuum vessel to the optical bench, yet provides a compact and economical structure. The vacuum vessel is mounted, through a sidewall thereof, to a support wall at four symmetrically positioned and spaced apart areas, each of which comprises a symmetrically positioned group of mounting structures passing through the sidewall of the vacuum vessel. The optical bench is pivotally secured to the vacuum vessel by four symmetrically spaced apart bolts and spherical bearings, each of which is centrally positioned within one of the four symmetrically positioned groups of vacuum vessel mounting structures. Cover plates and o-ring seals are further provided to seal the vacuum vessel mounting structures from the interior of the vacuum vessel, and venting bores are provided to vent trapped gases in the bores used to secure the cover plates and o-rings to the vacuum vessel. Provision for detecting leaks in the mounting structures from the rear surface of the vacuum vessel sidewall facing the support wall are also provided. Deflection to the optical bench within the vacuum vessel is further minimized by tuning the structure for a resonant frequency of at least 100 Hertz. 10 figures.

Active Optical Zoom for Tracking

DTIC Science & Technology

2008-09-01

optical system. 2. Current Setup Deformable Flat Two Deformable Flat Figure 1. Zemax lens design layout and experimental layout on the...optical bench. Figure 1 is a ZEMAX design and setup on the optical bench of two Deformable Mirrors (DMs) from OKO technologies. These mirrors have

A New Optical Bench Concept for Space-Based Laser Interferometric Gravitational Wave Missions

NASA Astrophysics Data System (ADS)

Chilton, Andrew; Apple, Stephen; Ciani, Giacomo; Olatunde, Taiwo; Conklin, John; Mueller, Guido

2015-04-01

Space-based interferometric gravitational wave detectors such as LISA have been proposed to detect low-frequency gravitational wave sources such as the inspirals of compact objects into massive black holes or two massive black holes into each other. The optical components used to perform the high-precision interferometry required to make these measurements have historically been bonded to Zerodur optical benches, which are thermally ultrastable but difficult and time-consuming to manufacture. More modern implementations of LISA-like interferometry have reduced the length stability requirement on these benches from 30fm/√{Hz} to a few pm √{ Hz}. We therefore propose to alter the design of the optical bench in such a way as to no longer require the use of Zerodur; instead, we plan to replace it with more easily-used materials such as titanium or molybdenum. In this presentation, we discuss the current status of and future plans for the construction and testing of such an optical bench.

Digital optical correlator x-ray telescope alignment monitoring system

NASA Astrophysics Data System (ADS)

Lis, Tomasz; Gaskin, Jessica; Jasper, John; Gregory, Don A.

2018-01-01

The High-Energy Replicated Optics to Explore the Sun (HEROES) program is a balloon-borne x-ray telescope mission to observe hard x-rays (˜20 to 70 keV) from the sun and multiple astrophysical targets. The payload consists of eight mirror modules with a total of 114 optics that are mounted on a 6-m-long optical bench. Each mirror module is complemented by a high-pressure xenon gas scintillation proportional counter. Attached to the payload is a camera that acquires star fields and then matches the acquired field to star maps to determine the pointing of the optical bench. Slight misalignments between the star camera, the optical bench, and the telescope elements attached to the optical bench may occur during flight due to mechanical shifts, thermal gradients, and gravitational effects. These misalignments can result in diminished imaging and reduced photon collection efficiency. To monitor these misalignments during flight, a supplementary Bench Alignment Monitoring System (BAMS) was added to the payload. BAMS hardware comprises two cameras mounted directly to the optical bench and rings of light-emitting diodes (LEDs) mounted onto the telescope components. The LEDs in these rings are mounted in a predefined, asymmetric pattern, and their positions are tracked using an optical/digital correlator. The BAMS analysis software is a digital adaption of an optical joint transform correlator. The aim is to enhance the observational proficiency of HEROES while providing insight into the magnitude of mechanically and thermally induced misalignments during flight. Results from a preflight test of the system are reported.

The New LOTIS Test Facility

NASA Technical Reports Server (NTRS)

Bell, R. M.; Cuzner, G.; Eugeni, C.; Hutchison, S. B.; Merrick, A. J.; Robins, G. C.; Bailey, S. H.; Ceurden, B.; Hagen, J.; Kenagy, K.;

Integrated wide-angle scanner based on translating a curved mirror of acylindrical shape.

PubMed

Sabry, Yasser M; Khalil, Diaa; Saadany, Bassam; Bourouina, Tarik

2013-06-17

A wide angle microscanning architecture is presented in which the angular deflection is achieved by displacing the principle axis of a curved silicon micromirror of acylindrical shape, with respect to the incident beam optical axis. The micromirror curvature is designed to overcome the possible deformation of the scanned beam spot size during scanning. In the presented architecture, the optical axis of the beam lays in-plane with respect to the substrate opening the door for a completely integrated and self-aligned miniaturized scanner. A micro-optical bench scanning device, based on translating a 200 μm focal length micromirror by an electrostatic comb-drive actuator, is implemented on a silicon chip. The microelectromechanical system has a resonance frequency of 329 Hz and a quality factor of 22. A single-mode optical fiber is used as the optical source and inserted into a micromachined groove fabricated and lithographically aligned with the microbench. Optical deflection angles up to 110 degrees are demonstrated.

Parabolic trough receiver heat loss and optical efficiency round robin 2015/2016

NASA Astrophysics Data System (ADS)

Pernpeintner, Johannes; Schiricke, Björn; Sallaberry, Fabienne; de Jalón, Alberto García; López-Martín, Rafael; Valenzuela, Loreto; de Luca, Antonio; Georg, Andreas

2017-06-01

A round robin for parabolic trough receiver heat loss and optical efficiency in the laboratory was performed between five institutions using five receivers in 2015/2016. Heat loss testing was performed at three cartridge heater test benches and one Joule heating test bench in the temperature range between 100 °C and 550 °C. Optical efficiency testing was performed with two spectrometric test bench and one calorimetric test bench. Heat loss testing results showed standard deviations at the order of 6% to 12 % for most temperatures and receivers and a standard deviation of 17 % for one receiver at 100 °C. Optical efficiency is presented normalized for laboratories showing standard deviations of 0.3 % to 1.3 % depending on the receiver.

Dynamics of solid lubrication as observed by optical microscopy

NASA Technical Reports Server (NTRS)

Sliney, H. E.

1976-01-01

A bench metallograph was converted into a micro contact imager by the addition of a tribometer employing a steel ball in sliding contact with a glass disk. The sliding contact was viewed in real time by means of projection microscope optics. The dynamics of abrasive particles and of solid lubricant particles within the contact were observed in detail. The contact was characterized by a constantly changing pattern of elastic strain with the passage of surface discontinuities and solid particles. Abrasive particles fragmented upon entering the contact, embedded in one surface and scratched the other; in contrast, the solid lubricant particles flowed plastically into thin films. The rheological behavior of the lubricating solids gave every appearance of a paste-like consistency within the Hertzian contact.

A rigid and thermally stable all ceramic optical support bench assembly for the LSST Camera

NASA Astrophysics Data System (ADS)

Kroedel, Matthias; Langton, J. Brian; Wahl, Bill

2017-09-01

This paper will present the ceramic design, fabrication and metrology results and assembly plan of the LSST camera optical bench structure which is using the unique manufacturing features of the HB-Cesic technology. The optical bench assembly consists of a rigid "Grid" fabrication supporting individual raft plates mounting sensor assemblies by way of a rigid kinematic support system to meet extreme stringent requirements for focal plane planarity and stability.

Survival or Revival: Long-Term Preservation Induces a Reversible Viable but Non-Culturable State in Methane-Oxidizing Bacteria

PubMed Central

Hoefman, Sven; Van Hoorde, Koenraad; Boon, Nico; Vandamme, Peter; De Vos, Paul; Heylen, Kim

2012-01-01

Knowledge on long-term preservation of micro-organisms is limited and research in the field is scarce despite its importance for microbial biodiversity and biotechnological innovation. Preservation of fastidious organisms such as methane-oxidizing bacteria (MOB) has proven difficult. Most MOB do not survive lyophilization and only some can be cryopreserved successfully for short periods. A large-scale study was designed for a diverse set of MOB applying fifteen cryopreservation or lyophilization conditions. After three, six and twelve months of preservation, the viability (via live-dead flow cytometry) and culturability (via most-probable number analysis and plating) of the cells were assessed. All strains could be cryopreserved without a significant loss in culturability using 1% trehalose in 10-fold diluted TSB (TT) as preservation medium and 5% DMSO as cryoprotectant. Several other cryopreservation and lyophilization conditions, all of which involved the use of TT medium, also allowed successful preservation but showed a considerable loss in culturability. We demonstrate here that most of these non-culturables survived preservation according to viability assessment indicating that preservation induces a viable but non-culturable (VBNC) state in a significant fraction of cells. Since this state is reversible, these findings have major implications shifting the emphasis from survival to revival of cells in a preservation protocol. We showed that MOB cells could be significantly resuscitated from the VBNC state using the TT preservation medium. PMID:22539945

Sub-arcsecond, differential deflectometry to measure thermally induced distortions of the Swift optical bench

NASA Astrophysics Data System (ADS)

Leviton, Douglas B.; Frey, Brad J.; Madison, Larry E.; Parker, James A.; Sheinman, Oren E.

2003-03-01

The Swift optical bench is a roughly 2.7 m diameter, 0.1 m thick composite structure carrying the Burst Alert Telescope (BAT), X-ray Telescope (XRT), and the Ultraviolet Optical Telescope (UVOT) as well as various attitude control instrumentation for the spacecraft. A high precision test of the optical bench using multi-aperture optical deflectometry was developed to verify that the relative boresights of the XRT and UVOT instruments would not change by more than several arcseconds when a worst case on-orbit temperature gradient is imposed through the thickness of the bench. Results of validation tests in a laminar flow cleanroom environment without vibration isolation demonstrated a differential measurement capability with 0.2 arcsecond sensitivity and 0.5 arcsecond accuracy per day. The technique is easily adaptable to similar deflection monitoring requirements for other large spacecraft structures.

Dobson space telescope: development of an optical payload of the next generation

NASA Astrophysics Data System (ADS)

Segert, Tom; Danziger, Björn; Gork, Daniel; Lieder, Matthias

2017-11-01

The Dobson Space Telescope (DST) is a research project of the Department of Astronautics at the TUBerlin. For Development and commercialisation there is a close cooperation with the network of the Berlin Space Industry (RIBB). Major Partner is the Astro- und Feinwerktechnik Adlershof GmbH a specialist for space structures and head of the industry consortia which built the DLR BIRD micro satellite. The aim of the project is to develop a new type of deployable telescope that can overcome the mass and volume limitations of small satellites. With the DST payload micro satellites of the 100kg class will be able to carry 50cm main mirror diameter optics (→ 1m GSD). Basis of this technology is the fact that a telescope is mainly empty space between the optical elements. To fold down the telescope during launch and to undfold it after the satellite reached its orbit can save 70% of payload volume and 50% of payload mass. Since these advantages continue along the value added chain DST is of highest priority for the next generation of commercial EO micro satellites. Since 2002 the key technologies for DST have been developed in test benches in Labs of TU-Berlin and were tested on board a ESA parabolic flight campaign in 2005. The development team at TU-Berlin currently prepares the foundation of a start-up company for further development and commercialisation of DST.

Bottleneck limitations for microRNA-based therapeutics from bench to the bedside.

PubMed

Chen, Yan; Zhao, Hongliang; Tan, Zhijun; Zhang, Cuiping; Fu, Xiaobing

2015-03-01

MicroRNAs are endogenous non-coding small RNAs that repress expression of a broad array of target genes. Research into the role and underlying molecular events of microRNAs in disease processes and the potential of microRNAs as drug targets has expanded rapidly. Significant advances have been made in identifying the associations of microRNAs with cancers, viral infections, immune diseases, cardiovascular diseases, wound healing, biological development and other areas of medicine. However, because of intense competition and financial risks, there is a series of stringent criteria and conditions that must be met before microRNA-based therapeutics could be pursued as new drug candidates. In this review, we specifically emphasized the obstacles for bench-based microRNA to the bedside, including common barriers in basic research, application limitations while moving to the clinic at the aspects of vector delivery, off-target effects, toxicity mediation, immunological activation and dosage determination, which should be overcome before microRNA-based therapeutics take their place in the clinic.

An elegant Breadboard of the optical bench for eLISA/NGO

NASA Astrophysics Data System (ADS)

d'Arcio, Luigi; Bogenstahl, Johanna; Diekmann, Christian; Fitzsimons, Ewan D.; Heinzel, Gerhard; Hogenhuis, Harm; Killow, Christian J.; Lieser, Maike; Nikolov, Susanne; Perreur-Lloyd, Michael; Pijnenburg, Joep; Robertson, David I.; Taylor, Alasdair; Tröbs, Michael; Ward, Harry; Weise, Dennis

2017-11-01

The Laser Interferometer Space Antenna, as well as its reformulated European-only evolution, the New Gravitational-Wave Observatory, both employ heterodyne laser interferometry on million kilometer scale arm lengths in a triangular spacecraft formation, to observe gravitational waves at frequencies between 3 × 10-5 Hz and 1 Hz. The Optical Bench as central payload element realizes both the inter-spacecraft as well as local laser metrology with respect to inertial proof masses, and provides further functions, such as point-ahead accommodation, acquisition sensing, transmit beam conditioning, optical power monitoring, and laser redundancy switching. These functions have been combined in a detailed design of an Optical Bench Elegant Breadboard, which is currently under assembly and integration. We present an overview of the realization and current performances of the Optical Bench subsystems, which employ ultraprecise piezo mechanism, ultrastable assembly techniques, and shot noise limited RF detection to achieve translation and tilt metrology at Picometer and Nanoradian noise levels.

eLISA Telescope In-field Pointing and Scattered Light Study

NASA Astrophysics Data System (ADS)

Livas, J.; Sankar, S.; West, G.; Seals, L.; Howard, J.; Fitzsimons, E.

2017-05-01

The orbital motion of the three spacecraft that make up the eLISA Observatory constellation causes long-arm line of sight variations of approximately ± one degree over the course of a year. The baseline solution is to package the telescope, the optical bench, and the gravitational reference sensor (GRS) into an optical assembly at each end of the measurement arm, and then to articulate the assembly. An optical phase reference is exchanged between the moving optical benches with a single mode optical fiber (“backlink” fiber). An alternative solution, referred to as in-field pointing, embeds a steering mirror into the optical design, fixing the optical benches and eliminating the backlink fiber, but requiring the additional complication of a two-stage optical design for the telescope. We examine the impact of an in-field pointing design on the scattered light performance.

Measuring mobbing experiences of academic nurses: development of a mobbing scale.

PubMed

Ozturk, Havva; Sokmen, Serap; Yilmaz, Fatma; Cilingir, Dilek

2008-09-01

The aims of this study were to develop a mobbing scale for academic nurses and to determine their mobbing experiences. Data were collected between January and June 2006 with a 60-item mobbing scale and a questionnaire composed of 6 questions concerning demographics and 10 questions regarding nurses' opinions about mobbing. For the Mobbing Scale for Academic Nurses, the content validity index was 88%, item-to-total correlations ranged from .41 to .73, Cronbach alpha was .97, and Kaiser-Meyer-Olkin measure of sampling adequacy was .72. Barlett's test yielded quite significant results (chi2= 7905.47, p = .000). The scale was composed of eight subscales. One fifth of the academic nurses experienced mobbing, and there was evidence of mobbing at university nursing schools. The mobbing scale for academic nurses can be used to collect reliable and accurate data about mobbing experienced by academic nurses. If there is mobbing in nursing faculties and schools, appropriate precautions should be taken to protect people against mobbing, and a safe and comfortable atmosphere must be created in nursing faculties and schools.

The HSOB GAIA: a cryogenic high stability cesic optical bench for missions requiring sub-nanometric optical stability

NASA Astrophysics Data System (ADS)

Courteau, Pascal; Poupinet, Anne; Kroedel, Mathias; Sarri, Giuseppe

2017-11-01

Global astrometry, very demanding in term of stability, requires extremely stable material for optical bench. CeSiC developed by ECM and Alcatel Alenia Space for mirrors and high stability structures, offers the best compromise in term of structural strength, stability and very high lightweight capability, with characteristics leading to be insensitive to thermo-elastic at cryogenic T°. The HSOB GAIA study realised by Alcatel Alenia Space under ESA contract aimed to design, develop and test a full scale representative High Stability Optical Bench in CeSiC. The bench has been equipped with SAGEIS-CSO laser metrology system MOUSE1, Michelson interferometer composed of integrated optics with a nm resolution. The HSOB bench has been submitted to an homogeneous T° step under vacuum to characterise the homothetic behaviour of its two arms. The quite negligible inter-arms differential measured with a nm range reproducibility, demonstrates that a complete 3D structure in CeSiC has the same CTE homogeneity as characterisation samples, fully in line with the GAIA need (1pm at 120K). This participates to the demonstration that CeSiC properties at cryogenic T° is fully appropriate to the manufacturing of complex highly stable optical structures. This successful study confirms ECM and Alcatel Alenia Space ability to define and manufacture monolithic lightweight highly stable optical structures, based on inner cells triangular design made only possible by the unique CeSiC manufacturing process.

ESPRESSO optical bench: from mind to reality

NASA Astrophysics Data System (ADS)

Tenegi, F.; Santana, S.; Gómez, J.; Rodilla, E.; Hughes, I.; Mégevand, D.; Rebolo, R.; Riva, M.; Luis-Simoes, R.

2016-07-01

ESPRESSO [1] is a high-resolution spectrograph under development for the VLT telescope. In general, the Optical Bench (OB) structure can be considered as a 3D one, conformed by welding thin plates of Structural Steel (St-52) with a nickelplated surface treatment, combined for getting maximum stiffness and minimum weight, that will be finally re-machined to get stringent geometrical and dimensional tolerances at I/Fs positions. TIG conventional welding procedure has been selected to minimize the cost and facilitate the own welding process. This solution follows the inheritance from HARPS [2] due to its success to achieve the required performance for the bench. This paper contains an overview of the whole process of designing and manufacturing the Optical Bench of ESPRESSO, from the very first beginning with the specifications to the current status of the bench with its integration on the Spectrograph (including the Finite Element Models and the delivery of the final structure by the supplier) and lessons learned.

Validation of an optical encoder during free weight resistance movements and analysis of bench press sticking point power during fatigue.

PubMed

Drinkwater, Eric J; Galna, Brook; McKenna, Michael J; Hunt, Patrick H; Pyne, David B

2007-05-01

During the concentric movement of the bench press, there is an initial high-power push after chest contact, immediately followed by a characteristic area of low power, the so-called "sticking region." During high-intensity lifting, a decline in power can result in a failed lift attempt. The purpose of this study was to determine the validity of an optical encoder to measure power and then employ this device to determine power changes during the initial acceleration and sticking region during fatiguing repeated bench press training. Twelve subjects performed a free weight bench press, a Smith Machine back squat, and a Smith Machine 40-kg bench press throw for power validation measures. All barbell movements were simultaneously monitored using cinematography and an optical encoder. Eccentric and concentric mean and peak power were calculated using time and position data derived from each method. Validity of power measures between the video (criterion) and optical encoder scores were evaluated by standard error of the estimate (SEE) and coefficient of variation (CV). Seven subjects then performed 4 sets of 6 free weight bench press repetitions progressively increasing from 85 to 95% of their 6 repetition maximum, with each repetition continually monitored by an optical encoder. The SEE for power ranged from 3.6 to 14.4 W (CV, 1.0-3.0%; correlation, 0.97-1.00). During the free weight bench press training, peak power declined by approximately 55% (p < 0.01) during the initial acceleration phase of the final 2 repetitions of the final set. Although decreases in power of the sticking point were significant (p < 0.01), as early as repetition 5 (-40%) they reached critically low levels in the final 2 repetitions (>-95%). In conclusion, the optical encoder provided valid measures of kinetics during free weight resistance training movements. The decline in power during the initial acceleration phase appears a factor in a failed lift attempt at the sticking point.

[Analysis of a case series of workers with mobbing syndrome].

PubMed

Marinoni, B; Minelli, C M; Franzina, B; Martellosio, V; Scafa, F; Giorgi, I; Mazzacane, F; Stancanelli, M; Mennoia, N V; Candura, S M

2007-01-01

Mobbing represents nowadays a major challenge for Occupational Medicine. We examined, during the last seven years, 253 patients who asked medical assistance for psychopathological problems by them ascribed to mobbing in the working environment. All patients underwent occupational health visit, psychological counselling (including personality tests administration), and psychiatric evaluation. A clinical picture probably due to mobbing was diagnosed in 37 workers: 2 cases of Post-Traumatic Stress Disorder (PTSD), 33 of Adjustment Disorder (AD), and 2 of anxiety disorder. Regarding mobbing typology, we found 19 cases of vertical mobbing (by an employer/manager to employees), 14 cases of strategic mobbing, 3 cases of horizontal mobbing (among colleagues), and one non intentional mobbing. In conclusion, a pure mobbing syndrome was diagnosed in a lower proportion than that reported by other investigators. The described interdisciplinary approach appears useful for the diagnostic assessment of suspect mobbing cases, that in turn is crucial for prognosis and treatment, as well as in relation to medico-legal issues and work-related compensation claims.

Characterization benches for neutrino telescope Optical Modules at the APC laboratory

NASA Astrophysics Data System (ADS)

Avgitas, Theodore; Creusot, Alexandre; Kouchner, Antoine

2016-04-01

As has been demonstrated by the first generation of neutrino telescopes Antares and IceCube, precise knowledge of the photon detection efficiency of optical modules is of fundamental importance for the understanding of the instrument and accurate event reconstruction. Dedicated test benches have been developed to measure all related quantities for the Digital Optical Modules of the KM3NeT neutrino telescope being currently deployed in the Mediterranean sea. The first bench is a black box with robotic arms equipped with a calibrated single photon source or laser which enable a precise mapping of the detection efficiency at arbitrary incident angles as well as precise measurements of the time delays induced by the photodetection chain. These measurement can be incorporated and compared to full GEANT MonteCarlo simulations of the optical modules. The second bench is a 2 m×2 m ×2 m water tank equipped with muon hodoscopes on top and bottom. It enables to study and measure the angular dependence of the DOM's detection efficiency of the Cherenkov light produced in water by relativistic muons, thus reproducing in situ detection conditions. We describe these two benches and present their first results and status.

Altering Neurospora crassa MOB2A exposes its functions in development and affects its interaction with the NDR kinase COT1.

PubMed

Aharoni-Kats, Liran; Zelinger, Einat; Chen, She; Yarden, Oded

2018-06-01

The Neurospora crassa Mps One Binder (MOB) proteins MOB2A and MOB2B physically interact with the Nuclear Dbf2 Related (NDR) kinase COT1 and have been shown to have overlapping functions in various aspects of asexual development. Here, we identified two N. crassa MOB2A residues, Tyr117 and Tyr119, which are potentially phosphorylated. Using phosphomimetic mob-2a mutants we have been able to establish that apart from their previously described roles, MOB2A/B are involved in additional developmental processes. Enhanced conidial germination, accompanied by conidial agglutination, in the phosphomimetic mutants indicated that MOB2A is a negative regulator of germination. Thick-section imaging of perithecia revealed slow maturation and a lack of asci alignment in the mutant strains demonstrating a role for MOB2A in sexual development. We demonstrate that even though MOB2A and MOB2B have some overlapping functions, MOB2B cannot compensate for the roles MOB2A has in conidiation and germination. Altering Tyr residues 117 and 119 impaired the physical interactions between MOB2A and COT1, most likely contributing to some of the observed effects. As cot-1 and the phosphomimetic mutants share an extragenic suppressor (gul-1), we concluded that at least some of the effects imposed by altering Tyr117 and Tyr119 are mediated by the NDR kinase. © 2018 John Wiley & Sons Ltd.

Quasi-Monolithic Structures for Spaceflight Using Hydroxide-Catalysis Bonding

NASA Technical Reports Server (NTRS)

Preston, Alix; Thorpe, J. Ira; Miner, Linda

2012-01-01

Future space-based missions will take measurements of the universe with unprecedented results. To do this, these missions will require materials and bonding techniques with ever-increasing stability in order to make their measurements. As an example, the Laser Interferometer Space Antenna (LISA) will detect and observe gravitational waves in the 0.1 mHz to 1 Hz frequency range with strain sensitivities on the order of 10(exp -21) at its most sensitive frequency. To make these measurements, critical components such as the optical bench or telescope support structure, will need to have path-length stabilities of better than 1 pm/(square root)Hz. The baseline construction method for the LISA optical bench is to affix fused silica optical components to a Zerodur baseplate using hydroxide-catalysis bonding (HCB). HCB is a recently developed technique that allows the bonding of glasses, some metals, and silicon carbide with significant strength and stability with a bond thickness of less than a few micrometers. In addition, a wide range of surface profiles can be bonded using only a small amount of hydroxide solution. These characteristics make HCB ideal for adhering optical components in complex optical systems. In addition to being used to construct the LISA optical bench, the HCB technique shows great promise for constructing other structures such as hollow retroreflectors to be used for lunar laser ranging, or a visible nulling coronograph to be used for exo-planet detection. Here we present construction techniques that could be used to make an optical bench, hollow retroreflector, nulling coronograph, or other quasi-monolithic structures using HCB. In addition, we present dimensional stability results of an optical bench that was made using HCB, as well as HCB strength measurements.

Levels of mobbing perception among nurses in Eastern Turkey.

PubMed

Çevik Akyil, R; Tan, M; Saritaş, S; Altuntaş, S

2012-09-01

This is a descriptive and comparative study of levels of mobbing perception among nurses, causes and perpetrators of mobbing, reactions to and factors affecting mobbing. Data for the study were collected from a sample of 180 Turkish nurses between July 2007 and January 2008 using a three-part questionnaire. Nurses were frequently subjected to mobbing. Younger nurses, nurses with less institutional and professional experience, nurses with lower levels of education, and nurses working in internal medicine clinics and night shifts reported higher levels of mobbing. Nurses reported their managers as the most frequent perpetrators of mobbing, and bad working conditions as the most important cause of mobbing. Many participants reported that they had come to accept mobbing incidents and did not lodge any complaints prior to the study. However, they claimed that they will not tolerate mobbing any longer, and will lodge verbal and written complaints. © 2012 The Authors. International Nursing Review © 2012 International Council of Nurses.

3D MOEMS-based optical micro-bench platform for the miniaturization of sensing devices

NASA Astrophysics Data System (ADS)

Garcia-Blanco, Sonia; Caron, Jean-Sol; Leclair, Sébastien; Topart, Patrice A.; Jerominek, Hubert

2008-02-01

As we enter into the 21st century, the need for miniaturized portable diagnostic devices is increasing continuously. Portable devices find important applications for point-of-care diagnostics, patient self-monitoring and in remote areas, such as unpopulated regions where the cost of large laboratory facilities is not justifiable, underdeveloped countries and other remote locations such as space missions. The advantage of miniaturized sensing optical systems includes not only the reduced weight and size but also reduced cost, decreased time to results and robustness (e.g. no need for frequent re-alignments). Recent advances in micro-fabrication and assembly technologies have enabled important developments in the field of miniaturized sensing systems. INO has developed a technology platform for the three dimensional integration of MOEMS on an optical microbench. Building blocks of the platform include microlenses, micromirrors, dichroic beamsplitters, filters and optical fibers, which can be positioned using passive alignment structures to build the desired miniaturised system. The technology involves standard microfabrication, thick resist UV-lithography, thick metal electroplating, soldering, replication in sol-gel materials and flip-chip bonding processes. The technology is compatible with wafer-to-wafer bonding. A placement accuracy of +/- 5 μm has been demonstrated thanks to the integration of alignment marks co registered with other optical elements fabricated on different wafers. In this paper, the building blocks of the technology will be detailed. The design and fabrication of a 5x5 channels light processing unit including optical fibers, mirrors and collimating microlenses will be described. Application of the technology to various kinds of sensing devices will be discussed.

Structure and function of methanotrophic communities in a landfill-cover soil.

PubMed

Henneberger, Ruth; Lüke, Claudia; Mosberger, Lona; Schroth, Martin H

2012-07-01

In landfill-cover soils, aerobic methane-oxidizing bacteria (MOB) convert CH(4) to CO(2), mitigating emissions of the greenhouse gas CH(4) to the atmosphere. We investigated overall MOB community structure and assessed spatial differences in MOB diversity, abundance and activity in a Swiss landfill-cover soil. Molecular cloning, terminal restriction-fragment length polymorphism (T-RFLP) and quantitative PCR of pmoA genes were applied to soil collected from 16 locations at three different depths to study MOB community structure, diversity and abundance; MOB activity was measured in the field using gas push-pull tests. The MOB community was highly diverse but dominated by Type Ia MOB, with novel pmoA sequences present. Type II MOB were detected mainly in deeper soil with lower nutrient and higher CH(4) concentrations. Substantial differences in MOB community structure were observed between one high- and one low-activity location. MOB abundance was highly variable across the site [4.0 × 10(4) to 1.1 × 10(7) (g soil dry weight)(-1)]. Potential CH(4) oxidation rates were high [1.8-58.2 mmol CH(4) (L soil air)(-1) day(-1) ] but showed significant lateral variation and were positively correlated with mean CH(4) concentrations (P < 0.01), MOB abundance (P < 0.05) and MOB diversity (weak correlation, P < 0.17). Our findings indicate that Methylosarcina and closely related MOB are key players and that MOB abundance and community structure are driving factors in CH(4) oxidation at this landfill. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Proposed SLR Optical Bench Required to Track Debris Using 1550 nm Lasers

NASA Technical Reports Server (NTRS)

Shappirio, M.; Coyle, D. B.; McGarry, J. F.; Bufton, J.; Cheek, J. W.; Clarke, G.; Hull, S. M.; Skillman, D. R.; Stysley, P. R.; Sun, X.;

Mobbing Exposure of Anaesthesiology Residents in Turkey

PubMed Central

Aykut, Gülnihal; Efe, Esra Mercanoğlu; Bayraktar, Selcan; Şentürk, Sinem; Başeğmez, İrem; Özkumit, Özlem; Kabak, Elmas; Yavaşçaoğlu, Belgin; Bilgin, Hülya

2016-01-01

Objective In recent years, psychological problems that are caused by working conditions, like burn out syndrome, are more commonly observed. In our study, we aimed to evaluate mobbing exposure, factors causing mobbing and precautions for mobbing in residency students who are educated in anaesthesiology and reanimation clinics in Turkey. Methods After obtaining consent from the ethics committee, we sent our questionnaires to the secretariats of the departments by postal mail. Completed questionnaires were collected in our department’s secretariat blindly and randomly mixed. One hundred and one participants were returned the questionnaires. Data was statistically analysed in SPSS 21.0 software programme. Results During residency programme, sated to have experienced mobbing one or more time. Interestingly, 5.9% participants complained of physical mobbing. Mobbing exposure was more common in females. The most serious new onset psychosomatic symptoms stated during residency were committing suicide (2%), addiction (16%), severe depression (18%), panic attack (8%), more accidents (7%) and tendency of violence (15%). In mobbing group there was statistically significant dissatisfaction rate. Conclusion In professions where mobbing is common, incidences of psychiatric diseases and suicide attempts are high are increased. Who are under risk for experiencing mobbing should be noticed carefully to ensure good judgement and problems should be inspected objectively in a detailed manner. Anesthesiology societies and other medical professional societies should establish mobbing committees. Thus, mobbing problems can be resolved and healthy career oppurtunities can be presented to residents. PMID:27909591

Mobbing Exposure of Anaesthesiology Residents in Turkey.

PubMed

Aykut, Gülnihal; Efe, Esra Mercanoğlu; Bayraktar, Selcan; Şentürk, Sinem; Başeğmez, İrem; Özkumit, Özlem; Kabak, Elmas; Yavaşçaoğlu, Belgin; Bilgin, Hülya

2016-08-01

In recent years, psychological problems that are caused by working conditions, like burn out syndrome, are more commonly observed. In our study, we aimed to evaluate mobbing exposure, factors causing mobbing and precautions for mobbing in residency students who are educated in anaesthesiology and reanimation clinics in Turkey. After obtaining consent from the ethics committee, we sent our questionnaires to the secretariats of the departments by postal mail. Completed questionnaires were collected in our department's secretariat blindly and randomly mixed. One hundred and one participants were returned the questionnaires. Data was statistically analysed in SPSS 21.0 software programme. During residency programme, sated to have experienced mobbing one or more time. Interestingly, 5.9% participants complained of physical mobbing. Mobbing exposure was more common in females. The most serious new onset psychosomatic symptoms stated during residency were committing suicide (2%), addiction (16%), severe depression (18%), panic attack (8%), more accidents (7%) and tendency of violence (15%). In mobbing group there was statistically significant dissatisfaction rate. In professions where mobbing is common, incidences of psychiatric diseases and suicide attempts are high are increased. Who are under risk for experiencing mobbing should be noticed carefully to ensure good judgement and problems should be inspected objectively in a detailed manner. Anesthesiology societies and other medical professional societies should establish mobbing committees. Thus, mobbing problems can be resolved and healthy career oppurtunities can be presented to residents.

Stable MOB1 interaction with Hippo/MST is not essential for development and tissue growth control.

PubMed

Kulaberoglu, Yavuz; Lin, Kui; Holder, Maxine; Gai, Zhongchao; Gomez, Marta; Assefa Shifa, Belul; Mavis, Merdiye; Hoa, Lily; Sharif, Ahmad A D; Lujan, Celia; Smith, Ewan St John; Bjedov, Ivana; Tapon, Nicolas; Wu, Geng; Hergovich, Alexander

2017-09-25

The Hippo tumor suppressor pathway is essential for development and tissue growth control, encompassing a core cassette consisting of the Hippo (MST1/2), Warts (LATS1/2), and Tricornered (NDR1/2) kinases together with MOB1 as an important signaling adaptor. However, it remains unclear which regulatory interactions between MOB1 and the different Hippo core kinases coordinate development, tissue growth, and tumor suppression. Here, we report the crystal structure of the MOB1/NDR2 complex and define key MOB1 residues mediating MOB1's differential binding to Hippo core kinases, thereby establishing MOB1 variants with selective loss-of-interaction. By studying these variants in human cancer cells and Drosophila, we uncovered that MOB1/Warts binding is essential for tumor suppression, tissue growth control, and development, while stable MOB1/Hippo binding is dispensable and MOB1/Trc binding alone is insufficient. Collectively, we decrypt molecularly, cell biologically, and genetically the importance of the diverse interactions of Hippo core kinases with the pivotal MOB1 signal transducer.The Hippo tumor suppressor pathway is essential for development and tissue growth control. Here the authors employ a multi-disciplinary approach to characterize the interactions of the three Hippo kinases with the signaling adaptor MOB1 and show how they differently affect development, tissue growth and tumor suppression.

Magister Magistri Lupus? "Mobbing" am Arbeitsplatz Schule (Magister Magistri Lupus? Mobbing in Schools).

ERIC Educational Resources Information Center

Rothland, Martin

2003-01-01

Sketches the background of mobbing (bullying) in the workplace. Analyzes the school related debate on mobbing. Takes into account the structure and interaction related characteristics of the teaching profession. Asks whether these characteristics can lead to a higher potential for mobbing and how this potential should be assessed. (CAJ)

A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions

NASA Astrophysics Data System (ADS)

Danner, Rolf; Dailey, D.; Lillie, C.

2011-09-01

The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

Incorporating 2D Materials with Micro-electromechanical Systems to Explore Strain Physics and Devices

NASA Astrophysics Data System (ADS)

Christopher, Jason; Vutukuru, Mounika; Kohler, Travis; Bishop, David; Swan, Anna; Goldberg, Bennett

2D materials can withstand an order of magnitude more strain than their bulk counterparts which can be used to dramatically change electrical, thermal and optical properties or even cause unconventional behavior such as generating pseudo-magnetic fields. Here we present micro-electromechanical systems (MEMS) as a platform for straining 2D materials to make such novel phenomena accessible. Unlike other strain techniques, MEMS are capable of precisely controlling the magnitude and orientation of the strain field and are readily integrated with current technology facilitating a path from lab bench to application. In this study, we use graphene as our prototypical 2D material, and determine strain via micro-Raman spectroscopy making extensive use of graphene's well-characterized phonon strain response. We report on the strength of various techniques for affixing graphene to MEMS, and investigate the role of surface morphology and chemistry in creating a high friction interface capable of inducing large strain. This work is supported by NSF DMR Grant 1411008, and author J. Christopher thanks the NDSEG program for its support.

Referential calls coordinate multi-species mobbing in a forest bird community.

PubMed

Suzuki, Toshitaka N

2016-01-01

Japanese great tits ( Parus minor ) use a sophisticated system of anti-predator communication when defending their offspring: they produce different mobbing calls for different nest predators (snake versus non-snake predators) and thereby convey this information to conspecifics (i.e. functionally referential call system). The present playback experiments revealed that these calls also serve to coordinate multi-species mobbing at nests; snake-specific mobbing calls attracted heterospecific individuals close to the sound source and elicited snake-searching behaviour, whereas non-snake mobbing calls attracted these birds at a distance. This study demonstrates for the first time that referential mobbing calls trigger different formations of multi-species mobbing parties.

[Questionnaire for the mobbing risk: CDL2.0].

PubMed

Gilioli, R; Cassitto, M G; Campanini, P; Punzi, S; Consonni, D; Rengo, C; Fattorini, E; Foá, V

2005-01-01

The aim of the study is to develop and validate a questionnaire able to evaluate the risk of mobbing at the workplace. A multiple-choice questionnaire has been developed which contains, among the different items, only one revealing a mobbing situation. The questionnaire has been administered to two groups (group A--243 subjects in a mobbing situation and group B--63 subjects without exposure to mobbing) and the differences in the scores obtained have been analysed. The questionnaire has proved to be valid and reliable. The results show that the presence of five mobbing actions is sufficient to define the workplace situation as potentially at risk for mobbing. The study reveals some limits in the selection of the two samples thus needing some adjustment. However, the questionnaire, also in the present form, can be considered a tool able to detect the mobbing situations.

Alfalfa Mob1-like proteins are involved in cell proliferation and are localized in the cell division plane during cytokinesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Citterio, Sandra; Piatti, Simonetta; Albertini, Emidio

2006-04-15

Mps-one-binder (Mob) proteins play a crucial role in yeast cytokinesis. After cloning two Mob1-like genes, MsMob1-A and MsMob1-B from alfalfa (Medicago sativa L.) we show that, although they are constitutively expressed in roots, stems, leaves, flowers and pods, their transcripts and proteins are mostly produced in actively proliferating tissues. A polyclonal antibody specifically raised against MsMob1 proteins was used for immunolocalization studies in synchronized root tip cells. The subcellular localization of MsMob1-like proteins is demonstrated to be cell cycle-regulated. Cytoplasmic localization is faint and diffused during G{sub 1} and S. It becomes concentrated in punctuate and fibrillar structures in G{submore » 2} as well as M phase. At the stage of cytokinesis, the protein is found at the emerging cell plate marking the progressive formation of the septum. Mob1 proteins partially co-localize with microtubules structures functionally related to the spindles and important for cytokinesis in eukaryotic cells. The MsMob1 expression cannot rescue the lethality of the yeast mob1 mutant, suggesting that interaction of Mob1 proteins with their effectors may be species-specific. Localization of Mob1 proteins in the inner layer of the root cap indicates an additional function for this class of proteins in plants, which is likely related to the onset of programmed cell death.« less

Mobbing against nurses in the workplace in Turkey.

PubMed

Efe, S Y; Ayaz, S

2010-09-01

The aim of the study was to determine whether the nurses have been exposed to mobbing or not, and to reveal the causes of the mobbing between 3 November 2008 and 31 December 2008. This research was a mixed method study involving survey and focus group interviews. The sample was calculated using sample calculation formula, and 206 nurses were included in the survey study. Four focus group interviews were later carried out with 16 nurses. The survey method and semi-structured question form were used to collect data. The percentage and chi-square were used to evaluate the quantitative data, and for the analysis of the qualitative data, descriptive analyses were made through direct quotations from the nurses' statements. According to the mobbing scale, 9.7% of the nurses had been exposed to mobbing, but according to their own declarations, 33% had been exposed. Some of the nurses (25.2%) who expressed that they had been exposed to mobbing reported that the executor of mobbing was the head nurse and 9.2% said that the reason for mobbing was 'communication problems'. Nurses under 25 years of age and those who work in intensive care units are apparently exposed to mobbing more frequently than others (P<0.05). It is suggested that head nurses' mobbing behaviours should be determined and they should be educated about leadership. Nurses should be educated about assertiveness to prevent mobbing. The necessary measures should be adopted to solve the 'communication problems', which are shown as a major reason for mobbing.

Design, assembly, and optical bench testing of a high-numerical-aperture miniature injection-molded objective for fiber-optic confocal reflectance microscopy.

PubMed

Chidley, Matthew D; Carlson, Kristen D; Richards-Kortum, Rebecca R; Descour, Michael R

2006-04-10

The design, analysis, assembly methods, and optical-bench test results for a miniature injection-molded plastic objective lens used in a fiber-optic confocal reflectance microscope are presented. The five-lens plastic objective was tested as a stand-alone optical system before its integration into a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. The system performance of the miniature objective lens is measured by use of an industry-accepted slanted-edge modulation transfer function (MTF) metric. An estimated Strehl ratio of 0.61 and a MTF value of 0.66 at the fiber-optic bundle Nyquist frequency have been obtained. The optical bench testing system is configured to permit interactive optical alignment during testing to optimize performance. These results are part of an effort to demonstrate the manufacturability of low-cost, high-performance biomedical optics for high-resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to permit wide-scale clinical screening and detection of early cancers and precancerous lesions.

Dim star fringe stabilization demonstration using pathlength feed-forward on the SIM testbed 3 (STB3)

NASA Astrophysics Data System (ADS)

Goullioud, Renaud; Alvarez-Salazar, Oscar S.; Nemati, Bijan

2003-02-01

Future space-based optical interferometers such as the Space Interferometer Mission require fringe stabilization to the level of nanometers in order to produce astrometric data at the micro-arc-second level. Even the best attitude control system available to date will not be able to stabilize the attitude of a several thousand pound spacecraft to a few milli-arc-seconds. Active pathlength control is usually implemented to compensate for attitude drift of the spacecraft. This issue has been addressed in previous experiments while tracking bright stars. In the case of dim stars, as the sensor bandwidth falls below one hertz, feedback control will not provide sufficient rejection. However, stabilization of the fringes from a dim-star down to the nanometer level can be done open loop using information from additional interferometers looking at bright guide stars. The STB3 testbed developed at the Jet Propulsion Laboratory features three optical interferometers sharing a common baseline, dynamically representative to the SIM interferometer. An artificial star feeding the interferometers is installed on a separate optics bench. Voice coils are used to simulate the attitude motion of the spacecraft by moving the entire bench. Data measured on STB3 show that fringe motion of a dim star due to spacecraft attitude changes can be attenuated by 80 dB at 0.1Hz without feedback control, using only information from two guide stars. This paper describes the STB3 setup, the pathlength feed-forward architecture, implementation issues and data collected with the system.

Function of snake mobbing in spectral tarsiers.

PubMed

Gursky, Sharon

2006-04-01

Numerous species are known for their tendency to approach and confront their predators as a group. This behavior is known as mobbing. Snakes seem to be one of the more consistent recipients of this type of predator-directed behavior. This paper explores individual differences (sex and age) in the mobbing behavior of the spectral tarsier toward live and model snakes. This study was conducted at Tangkoko Nature Reserve (Sulawesi, Indonesia) during 2003-2004. During this research, 11 natural mobbing events and 31 artificially induced mobbing events were observed. The mean number of individuals at a mobbing was 5.7. The duration of mobbing events was strongly correlated with the number of assembled mobbers. Adults were more likely than other age classes to participate in mobbings. Males were more likely than females to participate in mobbings. Mobbing groups often contained more than one adult male, despite the fact that no spectral tarsier group contains more than one adult male. No difference in body size between extragroup males and resident males was observed, refuting the "attract the mightier" hypothesis. The number of mobbers did not affect whether the tarsier or the snake retreated first, countering the "move-on" hypothesis. The "perception advertisement" hypothesis was tentatively supported, in that live snakes were rarely seen in the area following mobbing calls, in comparison to when tarsiers either ignored the snake or alarm call. Copyright 2006 Wiley-Liss, Inc.

A study on "mobbing" in maritime field: a case study in the Turkish maritime industry.

PubMed

Kum, Serdar; Ertas, Yildiray

2016-01-01

Nowadays, there are many reasons for people to be stressful and restless in their working environments. One of the reasons leading to this situation is known as "mobbing". The term "mobbing" means "bullying of an individual by a group". It usually happens among employees. The main effects of mobbing are the generation of stress and reduction of employee performance at work. In general, research shows that mobbing is particularly common in the public sector. The aim of this research is to understand the frequency of mobbing on employees in the Turkish maritime industry as a case study. In this study, a questionnaire survey on ship, shipyard, public and private company workers was applied to understand how often employees are exposed to mobbing. After analysing the results, it is also aimed to obtain information about the reasons and causes of mobbing, and then we can get some advice for this issue.

Influence of mobbing (workplace bullying) on depressive symptoms: a longitudinal study among employees working with people with intellectual disabilities.

PubMed

Figueiredo-Ferraz, H; Gil-Monte, P R; Olivares-Faúndez, V E

2015-01-01

The problem of mobbing has attracted a great deal of attention over the past few years. This concern has increased the study of the phenomena, which has resulted in many scientific publications. Mobbing has been characterised as an emerging risk at work. The aim of this longitudinal study was to analyse the influence of mobbing on depressive symptoms in a sample of employees working with people with intellectual disabilities (ID). The sample consisted of 372 Spanish employees working with people with ID at 61 job centres in the Valencian Community (Spain). Seventy-nine (21.2%) participants were men, and 293 were (78.8%) women. Mobbing was evaluated by the Mobbing-UNIPSICO scale, and depressive symptoms were measured using the Zung Self Rating Depression Scale. Using analyses of variance (anova), we tested the differences in depressive symptoms according to the mobbing criteria indicated by Leymann, that is, frequency and duration at Time 1 and Time 2. Employees who met the mobbing criteria: frequency (at least once a week) and duration (at least 6 months) at the two study times presented significantly higher levels of depressive symptoms than employees who met mobbing criteria at Time 1, but did not meet any criteria for mobbing at Time 2, and employees who did not meet any criteria for mobbing at Time 1 or Time 2. We conclude that permanence of mobbing from Time 1 to Time 2 increases depressive symptoms. © 2013 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

[Mobbing--a work related risk factor of service-based society?].

PubMed

Weber, A; Hörmann, G; Köllner, V

2007-05-01

About a decade the background of the both public and scientific increasing interest in the topic "mobbing". But unfortunately the term "mobbing" is often applied in dubious and inflationary way as synonym for each professional disagreement. The reason for this may among others be that until today no internationally acknowledged standard definition on mobbing exists. According to the in German operational and judicial practice contemporarily most frequent and favourite paraphrases mobbing includes: intended chicanery/hostility (systematics) towards a person (purpose, asymmetry of power) in certain frequency/continuity (at least once a week for six months) with the intention to ostracize a person from his/her employment. In the European states prevalence varies between 2% and 15%, in Germany a national report supports with representative data about 3%, here women are more affected than man. The highest prevalence rates are found in services sector and in public health, social services and education. Aetiology places mobbing mainly as a multi-factor process with complex reciprocity between individual and professional/social factors conditioned in many cases by unresolved conflicts or occupational changes. In first place mobbing is no medical diagnosis, but health injuries resulting from mobbing makes this phenomenon more and more important for social and professional medicine. In view of diagnostic safeguarding with respect to differential diagnostic clarification of a mobbing case good interdisciplinary cooperation of both internal and external protagonists is recommended. Mobbing interventions include individual (for instance social support) as well as operational measures (for instance role of top executives, calling in of a mediation committee). Prevention against occupational mobbing must given high attention. An essential part is regarded the introduction of occupational conventions against mobbing. Within the scope of juridical examination of mobbing results (for example regarding potential impairments of health) in individual case aspects of criminal, civil, social, industrial or occupational law have checked. Mobbing and by means of mobbing caused or conditioned impairments of health are due to present valid juridical regulations neither regarded as occupational disease according to section sign 9 paragraph 1 or 2 SGB II nor as industrial accident. From aspect of prevention ( section sign 14 SGB VII/ section sign 20 SGB V) mobbing has to be considered as a serious psychosocial health hazard conditioned by work.

Structural basis for Mob1-dependent activation of the core Mst–Lats kinase cascade in Hippo signaling

DOE PAGES

Ni, Lisheng; Zheng, Yonggang; Hara, Mayuko; ...

2015-06-24

The Mst–Lats kinase cascade is central to the Hippo tumor-suppressive pathway that controls organ size and tissue homeostasis. The adaptor protein Mob1 promotes Lats activation by Mst, but the mechanism remains unknown. Here, we show that human Mob1 binds to autophosphorylated docking motifs in active Mst2. This binding enables Mob1 phosphorylation by Mst2. Phosphorylated Mob1 undergoes conformational activation and binds to Lats1. We determine the crystal structures of phospho-Mst2–Mob1 and phospho-Mob1–Lats1 complexes, revealing the structural basis of both phosphorylation-dependent binding events. Further biochemical and functional analyses demonstrate that Mob1 mediates Lats1 activation through dynamic scaffolding and allosteric mechanisms. Thus, Mob1more » acts as a phosphorylation-regulated coupler of kinase activation by virtue of its ability to engage multiple ligands. We propose that stepwise, phosphorylation-triggered docking interactions of nonkinase elements enhance the specificity and robustness of kinase signaling cascades.« less

Structural design and analysis for an ultra low CTE optical bench for the Hubble Space Telescope corrective optics

NASA Technical Reports Server (NTRS)

Neam, Douglas C.; Gerber, John D.

1992-01-01

The stringent stability requirements of the Corrective Optics Space Telescope Axial Replacement (COSTAR) necessitates a Deployable Optical Bench (DOB) with both a low CTE and high resonant frequency. The DOB design consists of a monocoque thin shell structure which marries metallic machined parts with graphite epoxy formed structure. Structural analysis of the DOB has been integrated into the laminate design and optimization process. Also, the structural analytical results are compared with vibration and thermal test data to assess the reliability of the analysis.

GeoCARB design maturity and geostationary heritage

NASA Astrophysics Data System (ADS)

Sawyer, Kevin; Clark, Charles; Katz, Noah; Kumar, Jack; Nast, Ted; Palmer, Alice

2013-09-01

Our companion paper `Progress in development of Tropospheric Infrared Mapping Spectrometers (TIMS): geostationary greenhouse gas (GHG) application' describes geoCARB performance and science. Here we describe a geoCARB instrument design study leading to near PDR maturity. It is based on heritage geostationary (AIA and HMI on SDO, SBIRS GEO-1 and upcoming GLM on GOES-R as examples) and other (IRIS and NIRcam) flight instrumentation. Heritage work includes experience and well developed specifications for near a-thermal carbon fiber honeycomb composite optical benches and optical element mounting design forms that utilize a "family" of mounts for nearly any type of optical element. The geoCARB approach utilizes composite optical benches and bipod flexures to kinematically mount optics. Tooling for alignment and staking of all elements is integral to the design and is "removed before flight" for mass minimization. GeoCARB requires a cryogenic region for focal planes and spectrometers but front end optics and main structure are designed to run much warmer. A star tracker is used for geoCARB posteriori geolocation including pseudo-diurnal thermal distortion characterization. It is kinematically mounted by low conductance thermal isolators directly on to the low expansion high stiffness composite bench that defines the master optical surfaces including the scanning mirrors. The thermal load from the camera heads is routed away from the bench heat pipes. Use of kinematic mounting is advantageous for low thermal conduction designs. Honeycomb composites enable the design's low thermal mechanical distortions.

Methane-oxidizing seawater microbial communities from an Arctic shelf

NASA Astrophysics Data System (ADS)

Uhlig, Christiane; Kirkpatrick, John B.; D'Hondt, Steven; Loose, Brice

2018-06-01

Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydrate. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L-1, approximately 4.8 times oversaturated relative to atmospheric equilibrium. The group of methane-oxidizing bacteria (MOB) in the natural seawater and incubated seawater was > 97 % dominated by Methylococcales (γ-Proteobacteria). Incubations of seawater under a range of methane concentrations led to loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5 % at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were 4 times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotroph sequences correlated tightly with the rate constant (kox) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg-1 were found, Methylobacterium (α-Proteobacteria) was the dominant MOB with a relative abundance of 80 %. Total MOB abundances were very low in sea ice, with maximal fractions found at the ice-snow interface (0.1 %), while non-MOB methylotrophs were present in abundances similar to natural seawater communities. The dissimilarities in MOB taxa, methane concentrations, and stable isotope ratios between the sea ice and water column point toward different methane dynamics in the two environments.

STOP Analysis and Optimization of a Very-Low-Distortion Space Instrument: HST WFC3 Case Study

NASA Technical Reports Server (NTRS)

Kunt, Cengiz; Broduer, Steve (Technical Monitor)

2001-01-01

New generation optical instruments with very demanding stability requirements are being proposed and developed for space applications. STOP (Structural-Thermal-Optical Performance) analysis and optimization is crucial in meeting the very tight distortion budgets of these instruments. This presentation outlines STOP analysis and optimization approach in the context of WFC3 (Wide-Field Camera 3), which is a radial instrument designed to replace the Wide-Field Planetary Camera 2 (WFPC2) of the Hubble Space Telescope (HST). WFC3 houses two separate channels, UVIS and IR, and will have greater throughput and sensitivity than WFPC2. WFC3 line-of-sight alignment budget for the UVIS and IR channels are as small as 10 and 20 milli-arcsec, respectively. Its optical bench is the most critical subsystem effecting the optical stability of WFC3 hence our effort concentrates on the design and analysis of the bench and its interfaces. Structural analysis has accompanied the mechanical design of the bench since the initial concept study. A high fidelity structural Finite Element Model (FEM) of the bench has been developed and used for minimizing its thermally induced distortions as well as sizing it to meet the stiffness and strength requirements of a Shuttle launch. The bench is a composite honeycomb panel box structure with a very low planar Coefficient of Thermal Expansion (CTE) of approximately 0.1 ppm/C. Optic components are mounted to super-INVAR inserts bonded into the panels. The bench is kinematically supported on three HST latches via interface struts, which are tailored to exhibit negative CTE to cancel out the thermal motions of the latches. The interface struts also incorporate flexure elements to minimize the mechanical distortions coming into the bench from its enclosure. Bench FEM is coupled with the enclosure FEM to quantify these effects. Short term or on-orbit STOP analysis includes distortion due to the temperature variations of the bench, the struts, and the enclosure. Long term or ground-to-orbit STOP analysis includes distortional effects of gravity release, desorption, and assembly in addition to the ground-to-orbit temperature variations. A rigorous testing program has been implemented for verifying the material properties and the analysis predictions. STOP analysis results demonstrate that both the short-term and the long-term alignment budgets will be met. Presentation will cover design and analysis details that are critical to a successful implementation of the STOP analysis and optimization process.

USAF Space Sensing Cryogenic Considerations

DTIC Science & Technology

2010-01-01

Background IR emissions and electronic noise that is inherently present in Focal Plane Arrays (FPAs) and surveillance optics bench designs prevents their use... noise that is inherently present in Focal Plane Arrays (FPAs) and surveillance optics bench designs prevents their use unless they are cooled to...experimental or not of sufficient sensitivity for the before mentioned missions [2]. Examples include Quantum Well IR Photodetectors ( QWIP ), nanotubes

Photonic Low Cost Micro-Sensor for in-Line Wear Particle Detection in Flowing Lube Oils.

PubMed

Mabe, Jon; Zubia, Joseba; Gorritxategi, Eneko

2017-03-14

The presence of microscopic particles in suspension in industrial fluids is often an early warning of latent or imminent failures in the equipment or processes where they are being used. This manuscript describes work undertaken to integrate different photonic principles with a micro- mechanical fluidic structure and an embedded processor to develop a fully autonomous wear debris sensor for in-line monitoring of industrial fluids. Lens-less microscopy, stroboscopic illumination, a CMOS imager and embedded machine vision technologies have been merged to develop a sensor solution that is able to detect and quantify the number and size of micrometric particles suspended in a continuous flow of a fluid. A laboratory test-bench has been arranged for setting up the configuration of the optical components targeting a static oil sample and then a sensor prototype has been developed for migrating the measurement principles to real conditions in terms of operating pressure and flow rate of the oil. Imaging performance is quantified using micro calibrated samples, as well as by measuring real used lubricated oils. Sampling a large fluid volume with a decent 2D spatial resolution, this photonic micro sensor offers a powerful tool at very low cost and compacted size for in-line wear debris monitoring.

Photonic Low Cost Micro-Sensor for in-Line Wear Particle Detection in Flowing Lube Oils

PubMed Central

Mabe, Jon; Zubia, Joseba; Gorritxategi, Eneko

2017-01-01

The presence of microscopic particles in suspension in industrial fluids is often an early warning of latent or imminent failures in the equipment or processes where they are being used. This manuscript describes work undertaken to integrate different photonic principles with a micro- mechanical fluidic structure and an embedded processor to develop a fully autonomous wear debris sensor for in-line monitoring of industrial fluids. Lens-less microscopy, stroboscopic illumination, a CMOS imager and embedded machine vision technologies have been merged to develop a sensor solution that is able to detect and quantify the number and size of micrometric particles suspended in a continuous flow of a fluid. A laboratory test-bench has been arranged for setting up the configuration of the optical components targeting a static oil sample and then a sensor prototype has been developed for migrating the measurement principles to real conditions in terms of operating pressure and flow rate of the oil. Imaging performance is quantified using micro calibrated samples, as well as by measuring real used lubricated oils. Sampling a large fluid volume with a decent 2D spatial resolution, this photonic micro sensor offers a powerful tool at very low cost and compacted size for in-line wear debris monitoring. PMID:28335436

[Mobbing: its relationships with organizational culture and personal outcomes].

PubMed

Topa Cantisano, Gabriela; Morales Domínguez, José Francisco; Gallastegui Galán, José Antonio

2006-11-01

A study dealing with the effects of both organizational culture and mobbing on personal and organizational outcomes of a sample of Spanish emergency workers, is reported here. It was found that there is a strong impact of organizational culture dimensions on mobbing, and that mobbing affects job satisfaction, organizational commitment and organizational citizenship behaviour. Results concerning organizational commitment show that this variable is not a mere effect of mobbing in general, but rather that it is also a direct impact of culture on this outcome.

Mobbing behaviors encountered by nurse teaching staff.

PubMed

Yildirim, Dilek; Yildirim, Aytolan; Timucin, Arzu

2007-07-01

The term 'mobbing' is defined as antagonistic behaviors with unethical communication directed systematically at one individual by one or more individuals in the workplace. This cross-sectional and descriptive study was conducted for the purpose of determining the mobbing behaviors encountered by nursing school teaching staff in Turkey, its effect on them, and their responses to them. A large percentage (91%) of the nursing school employees who participated in this study reported that they had encountered mobbing behaviors in the institution where they work and 17% that they had been directly exposed to mobbing in the workplace. The academic staff who had been exposed to mobbing behaviors experienced various physiological, emotional and social reactions. They frequently 'worked harder and [were] more organized and worked very carefully to avoid criticism' to escape from mobbing. In addition, 9% of the participants stated that they 'thought about suicide occasionally'.

[Prevalence of mobbing in workers and factor risk associates].

PubMed

Medina-Gómez, Oswaldo Sinoe

2016-01-01

In Mexico there is little research to know the magnitude of mobbing. To identify the prevalence of mobbing and characteristics associated in workers. A cross-sectional study of 499 workers who use medical unit. A questionnaire was used to determine the presence of mobbing and various instruments to know the personality, vulnerability to stress, self-esteem and depression. Prevalence odds ratio, dispersion, chi-square and Poisson regression were calculated. A prevalence of 36% was found; no significant differences between sex or school level in mobbing presence, 20.2%, were found. Sixty per cent women are perceived as victims of harassment high relative to men (p = 0.04). Workers with low self-esteem have a greater association with high mobbing (p < 0.001). The prevalence found is higher than reported in previous studies in Mexico, strong associations between mobbing and personality and emotional disorders were identified.

Those Mean Girls and Their Friends: Bullying and Mob Rule in the Academy

ERIC Educational Resources Information Center

Dentith, Audrey M.; Wright, Robin Redmon; Coryell, Joellen

2015-01-01

This article highlights the stories and experiences of three White women who were victims of bullying and mobbing in academic settings. Related literature grounds their experiences and offers insights related to the phenomena including definitions of mobbing and bullying, characteristics of bullies, the prevalence of bullying and mobbing, and the…

Teachers' Perceptions Regarding Mobbing at Schools

ERIC Educational Resources Information Center

Gülcan, Murat Gürkan

2015-01-01

The aim of the study is to determine whether there are mobbing applications at schools and if so, at which level and between whom. The Mobbing Perception Scale is applied, based on Leymann's (1993), "Mobbing Typology," and developed by Yavuz (2007), to 154 teachers at 5 selected schools in Ankara for the purpose of the study. According…

The Effect of Assertiveness Training on the Mobbing That Nurses Experience.

PubMed

Karakaş, Sibel Asi; Okanli, Ayşe

2015-10-01

This research was designed to determine the impact of assertiveness training on the mobbing experience of nurses. This study was conducted in two phases. In the first phase, 218 nurses completed the mobbing scale; the education group consisted of 38 nurses who received a score at or above 204 points. A total of 180 nurses were excluded from the education group because they received less than 204 points. The study was conducted with 30 nurses because 8 nurses did not agree to participate in the study. The 30 nurses received the assertiveness training program. Six months after training, the nurses completed the mobbing scale and Rathus Assertiveness Inventory (RAI) again. The assertiveness training positively affected the assertiveness and mobbing scores (p = .000). After the training, the assertiveness scores increased and the mobbing condition score decreased (p < .01). Assertiveness training is an effective method for decreasing mobbing. In line with these results, training programs, which support nurses' personal development by providing counseling and support to nurse victims of mobbing, are recommended. © 2015 The Author(s).

Mobbing: a problem in flocking and deterrence

NASA Astrophysics Data System (ADS)

Elias Tousley, M.; Glaze, Owen; Schall, Anna; Amador Kane, Suzanne

2010-03-01

We present experimental and theoretical studies of one type of mobbing behavior in which swarms of prey animals (e.g., tree swallows) harass a predator (e.g., a red-tailed hawk). Empirical field data were collected for tree swallows mobbing a fixed model predator; previous studies have established that this experimental design provokes the same response as actual ``perch-and-wait'' predator behavior. We extended these earlier studies using stereometric video to record the three-dimensional trajectories of prey birds and mobbing cries; we also analyzed single-angle video data taken of crows mobbing red-tailed hawks in flight. Video recordings of red-tailed hawk flight were filmed and analyzed to establish the dynamics of potential predator attacks. The trajectory analysis employed particle-tracking methods and statistical analyses to understand and model the dynamical rules governing this behavior. Swarming behavior during mobbing exhibited a high degree of periodicity and coordination both for fixed predator and in-flight mobbing attacks. The trajectories of individual mobbing birds were analyzed as a random walk superimposed on an approximately elliptical flightpath. Computer simulation studies reproduce several aspects of this behavior, in particular explaining how the mobbing strategy employed by prey birds minimizes the risk of hawk predation while optimizing the frequency of harassing attacks.

[Does mobbing cause posttraumatic stress disorder? Impact of coping and personality].

PubMed

Kreiner, Barbara; Sulyok, Christoph; Rothenhäusler, Hans-Bernd

2008-01-01

Previous research has documented that a variety of anxiety, depressive, and psychosomatic symptoms are present in a substantial portion of mobbing victims. This study aimed to explore the frequency of posttraumatic stress disorder (PTSD) among mobbing victims, and to investigate how PTSD was linked to pertinent psychometric scales. We recruited 20 mobbing victims and conducted the Structural Clinical Interview (SCID) to assess PTSD according to DSM-IV criteria. The trauma criterion was homogeneously defined as mobbing. 55% of our entire sample had a current PTSD, and 70% suffered from severe posttraumatic stress symptoms according to the Impact of Event Scale. Using multivariate analysis of variance (MANOVA), we found that mobbing victims with a current PTSD tended to demonstrate higher levels of stress and depressive symptoms, and less quality of life (SF 36 Short-Form Health Survey), especially in terms of bodily pain, compared with those without a PTSD diagnosis. No significant differences in personality factors (Freiburg Personality Inventory) between mobbing-victims with and without PTSD were evident by multivariate analysis. Univariate statistics, however, revealed that mobbing-related PTSD showed a trend towards higher scores in social orientation and somatic complaints. There was no general evidence that mobbing victims with a PTSD used more often negative and positive coping strategies (SVF - Stress Coping Questionnaire). However, they showed a tendency to employ control strategies, avoidance, social withdrawal, and cognitive preoccupation. Posttraumatic stress disorder subsequent to mobbing can occur frequently. PTSD therefore should be specifically considered in routine care.

Correlating optical bench performance with clinical defocus curves in varifocal and trifocal intraocular lenses.

PubMed

Plaza-Puche, Ana B; Alió, Jorge L; MacRae, Scott; Zheleznyak, Len; Sala, Esperanza; Yoon, Geunyoung

2015-05-01

To investigate the correlations existing between a trifocal intraocular lens (IOL) and a varifocal IOL using the "ex vivo" optical bench through-focus image quality analysis and the clinical visual performance in real patients by study of the defocus curves. This prospective, consecutive, nonrandomized, comparative study included a total of 64 eyes of 42 patients. Three groups of eyes were differentiated according to the IOL implanted: 22 eyes implanted with the varifocal Lentis Mplus LS-313 IOL (Oculentis GmbH, Berlin, Germany); 22 eyes implanted with the trifocal FineVision IOL (Physiol, Liege, Belgium), and 20 eyes implanted with the monofocal Acrysof SA60AT IOL (Alcon Laboratories, Inc., Fort Worth, TX). Visual outcomes and defocus curve were evaluated postoperatively. Optical bench through-focus performance was quantified by computing an image quality metric and the cross-correlation coefficient between an unaberrated reference image and captured retinal images from a model eye with a 3.0-mm artificial pupil. Statistically significant differences among defocus curves of different IOLs were detected for the levels of defocus from -4.00 to -1.00 diopters (D) (P < .01). Significant correlations were found between the optical bench image quality metric results and logMAR visual acuity scale in all groups (Lentis Mplus group: r = -0.97, P < .01; FineVision group: r = -0.82, P < .01; Acrys of group: r = -0.99, P < .01). Linear predicting models were obtained. Significant correlations were found between logMAR visual acuity and image quality metric for the multifocal and monofocal IOLs analyzed. This finding enables surgeons to predict visual outcomes from the optical bench analysis. Copyright 2015, SLACK Incorporated.

An examination of mobbing and burnout of residents.

PubMed

Dikmetaş, Elif; Top, Mehmet; Ergin, Gülpembe

2011-01-01

Mobbing and burnout in human resources management are important topics in labor psychology. It is important to research the levels of mobbing and burnout of human resources in the health sector, primarily in doctors. Although there have been some studies on the mobbing and burnout of doctors, there has been a limited number of studies on the relationship between mobbing and burnout in the health sector. This study aims to examine the relationship between mobbing and burnout (emotional exhaustion, depersonalization, personal accomplishment) levels of resident doctors at a public university research and training hospital in Turkey and to investigate whether mobbing and burnout levels vary significantly according to gender, marital status, medical branch and age. This study was conducted on resident doctors at the Ondokuz Mayıs University Research and Training Hospital between 01.04.2009 and 30.06.2009. Legal permission for the study was received from the Rector's Office of Ondokuz Mayıs University. The Maslach Burnout Inventory for measuring burnout levels in doctors and the Leymann Inventory of Psychological Terror for measuring doctors' mobbing levels were the research instruments employed. Sampling was not used in this study. The aim was to administer the research instruments to all the residents (the universe of this study consisted of 510 assistant doctors). 52.94 % of residents responded to all of the questions in these instruments. In the data analysis, a t-test, ANOVA, regression analysis and descriptive statistics were used. At the end of the analyses, it was found that the mean mobbing level of residents is 1.97; the mean emotional exhaustion level of residents is 2.97; the mean level of depersonalization is 2.95; and the mean level of personal accomplishment is 2.94. Mobbing and burnout levels of residents vary significantly in terms of medical branch. This study indicated that there are relationships between mobbing, emotional exhaustion, depersonalization and personal accomplishment. Mobbing is a significant regressor for emotional exhaustion, depersonalization and personal accomplishment in this study.

Mobbing among care workers in nursing homes: A cross-sectional secondary analysis of the Swiss Nursing Homes Human Resources Project.

PubMed

Tong, Myriam; Schwendimann, René; Zúñiga, Franziska

2017-01-01

As a category of bullying, mobbing is a form of violence in the workplace that damages the employing organization as well as the targeted employee. In Europe, the overall prevalence of mobbing in healthcare is estimated at 4%. However, few studies have explored mobbing among long-term care workers. This study aims to examine the frequency of mobbing in Swiss nursing homes and its relationships with care workers' (i.e. registered nurse, licensed practical nurse, assistant nurse, nurse aide) health status, job satisfaction, and intention to leave, and to explore the work environment as a contributing factor to mobbing. A cross-sectional, multi-center sub-study of the Swiss Nursing Homes Human Resource Project (SHURP). Nursing homes in Switzerland's three language regions. A total of 162 randomly selected nursing homes with 20 or more beds, including 5311 care workers with various educational levels. Controlling for facility and care worker characteristics, generalized estimation equations were used to assess the relationships between mobbing and care workers' health status, job satisfaction, and intention to leave as well as the association of work environment factors with mobbing. In Swiss nursing homes, 4.6% of surveyed care workers (n=242) reported mobbing experiences in the last 6 months. Compared to untargeted persons, those directly affected by mobbing had higher odds of health complaints (Odds Ratios (OR): 7.81, 95% CI 5.56-10.96) and intention to leave (OR: 5.12, 95% CI 3.81-6.88), and lower odds of high job satisfaction (OR: 0.19, 95% CI 0.14-0.26). Odds of mobbing occurrences increased with declining teamwork and safety climate (OR: 0.41, 95% CI 0.30-0.58), less supportive leadership (OR: 0.42, 95% CI 0.30-0.58), and higher perceived inadequacy of staffing resources (OR: 0.66, 95% CI 0.48-0.92). Mobbing experiences in Swiss nursing homes are relatively rare. Alongside teamwork and safety climate, risk factors are strongly associated with superiors' leadership skills. Targeted training is necessary to sensitize managers to mobbing's indicators, effects and potential influencing factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recent progress in MEMS technology development for military applications

NASA Astrophysics Data System (ADS)

Ruffin, Paul B.; Burgett, Sherrie J.

2001-08-01

The recent progress of ongoing efforts at the Army Aviation and Missile Command (AMCOM) to develop microelectromechanical systems (MEMS) technology for military applications is discussed in this paper. The current maturity level of low cost, low power, micro devices in industry, which range from simple temperature and pressure sensors to accelerometers in airbags, provides a viable foundation for the development of rugged MEMS devices for dual-use applications. Early MEMS technology development efforts at AMCOM emphasized inertial MEMS sensors. An Army Science and Technology Objective (STO) project was initiated to develop low cost inertial components with moderate angular rate sensor resolution for measuring pitch and yaw of missile attitude and rotational roll rate. Leveraging the Defense Advanced Research Projects Agency and other Government agencies has resulted in the development of breadboard inertial MEMS devices with improved robustness. During the past two years, MEMS research at AMCOM has been expanded to include environmental MEMS sensors for missile health monitoring, RF-MEMS, optical MEMS devices for beam steering, and micro-optic 'benches' for opto-electronics miniaturization. Additionally, MEMS packaging and integration issues have come into focus and are being addressed. Selected ongoing research efforts in these areas are presented, and some horizon MEMS sensors requirements for Army and law enforcement are presented for consideration.

Optimal design of a thermally stable composite optical bench

NASA Technical Reports Server (NTRS)

Gray, C. E., Jr.

1985-01-01

The Lidar Atmospheric Sensing Experiment will be performed aboard an ER-2 aircraft; the lidar system used will be mounted on a lightweight, thermally stable graphite/epoxy optical bench whose design is presently subjected to analytical study and experimental validation. Attention is given to analytical methods for the selection of such expected laminate properties as the thermal expansion coefficient, the apparent in-plane moduli, and ultimate strength. For a symmetric laminate in which one of the lamina angles remains variable, an optimal lamina angle is selected to produce a design laminate with a near-zero coefficient of thermal expansion. Finite elements are used to model the structural concept of the design, with a view to the optical bench's thermal structural response as well as the determination of the degree of success in meeting the experiment's alignment tolerances.

Mobbing in the Schools. Scandinavian Initiatives in the Prevention and Reduction of Group Violence among Children.

ERIC Educational Resources Information Center

Juul, Kristen D.

The paper defines the concept of mobbing and notes alternate terms such as bullying, scapegoating, and group violence or aggression. Scandinavian research and literature on mobbing is analyzed, especially as it relates to the incidence of mobbing and characteristics of aggressor and victim. Intervention efforts are described, such as individual…

Cultural transmission of snake-mobbing in free-ranging Hanuman langurs.

PubMed

Srivastava, A

1991-01-01

A focal troop of free-ranging Hanuman langurs (Presbytis entellus) living in an open scrub forest around Jodhpur was observed mobbing poisonous snakes on two different occasions during field observations of about 4,109 h. These observations of snake-mobbing demonstrate that langurs exhibit a special behaviour against 'potentially dangerous animals' which is similar to the mobbing displays of birds, and of other primates. It is suggested that the adaptive significance of snake-mobbing among langurs lies in the 'cultural transmission' of this information. These observations further support the 'kin-selection' model.

Personality and psychopathological profiles in individuals exposed to mobbing.

PubMed

Girardi, Paolo; Monaco, Edoardo; Prestigiacomo, Claudio; Talamo, Alessandra; Ruberto, Amedeo; Tatarelli, Roberto

2007-01-01

Increasingly, mental health and medical professionals have been asked to assess claims of psychological harm arising from harassment at the workplace, or "mobbing." This study assessed the personality and psychopathological profiles of 146 individuals exposed to mobbing using validity, clinical, and content scales of the Minnesota Multiphasic Personality Inventory 2. Profiles and factor analyses were obtained. Two major dimensions emerged among those exposed to mobbing: (a) depressed mood, difficulty in making decisions, change-related anguish, and passive-aggressive traits (b) somatic symptoms, and need for attention and affection. This cross-sectional pilot study provides evidence that personality profiles of mobbing victims and psychological damage resulting from mobbing may be evaluated using standardized assessments, though a longitudinal study is needed to delineate cause-and-effect relationships.

[Psychosocial risk factors at work as predictors of mobbing].

PubMed

Meseguer de Pedro, Mariano; Soler Sánchez, María I; García-Izquierdo, Mariano; Sáez Navarro, M C; Sánchez Meca, Julio

2007-05-01

This work analyses the way in which various psychosocial risk indicators may predict mobbing. A sample of 638 workers, 168 men and 470 women, from the fruit-and-vegetable sector was evaluated. An anonymous questionnaire was administered to all employees who were present on the evaluation days in the companies comprising the study. After analysing the data obtained with the mobbing questionnaire NAQ-RE (Sáez, García-Izquierdo, and Llor, 2003) and with the psychosocial risk factors evaluation method of the INSHT (Martín and Pérez, 1997), using canonical regression, we found that several psychosocial factors such as role definition, mental workload, interest in the workers, and supervision / participation predict two types of mobbing: personal mobbing and work-performance-related mobbing.

Lions, hyenas and mobs (oh my!)

PubMed Central

Montgomery, Tracy M.; MacLachlan, Sarah M.; Parker, Jenna M.; Spagnuolo, Olivia S.; VandeWetering, Kelsey J.; Bills, Patrick S.; Holekamp, Kay E.

2017-01-01

Abstract Understanding the factors that facilitate the emergence of cooperation among organisms is central to the study of social evolution. Spotted hyenas Crocuta crocuta frequently cooperate to mob lions Panthera leo, approaching the lions as a tightknit group while vocalizing loudly in an attempt to overwhelm them and drive them away. Whereas cooperative mobbing behavior has been well documented in birds and some mammals, to our knowledge it has never been described during interactions between 2 apex predators. Using a 27-year dataset, we characterize lion–hyena encounters, assess rates of mobbing behavior observed during these interactions, and inquire whether mobbing results in successful acquisition of food. Lions and hyenas interacted most often at fresh kills, especially as prey size and the number of hyenas present increased. Possession of food at the beginning of an interaction positively affected retention of that food by each predator species. The presence of male lions increased the probability of an interspecific interaction but decreased the likelihood of hyenas obtaining or retaining possession of the food. Hyena mobbing rates were highest at fresh kills, but lower when adult male lions were present. The occurrence of mobbing was predicted by an increase in the number of hyenas present. Whether or not mobbing resulted in acquisition of food from lions was predicted by an increase in the number of mobs formed by the hyenas present, suggesting that cooperation among hyenas enhances their fitness. PMID:29491990

Lions, hyenas and mobs (oh my!).

PubMed

Lehmann, Kenna D S; Montgomery, Tracy M; MacLachlan, Sarah M; Parker, Jenna M; Spagnuolo, Olivia S; VandeWetering, Kelsey J; Bills, Patrick S; Holekamp, Kay E

2017-06-01

Understanding the factors that facilitate the emergence of cooperation among organisms is central to the study of social evolution. Spotted hyenas Crocuta crocuta frequently cooperate to mob lions Panthera leo , approaching the lions as a tightknit group while vocalizing loudly in an attempt to overwhelm them and drive them away. Whereas cooperative mobbing behavior has been well documented in birds and some mammals, to our knowledge it has never been described during interactions between 2 apex predators. Using a 27-year dataset, we characterize lion-hyena encounters, assess rates of mobbing behavior observed during these interactions, and inquire whether mobbing results in successful acquisition of food. Lions and hyenas interacted most often at fresh kills, especially as prey size and the number of hyenas present increased. Possession of food at the beginning of an interaction positively affected retention of that food by each predator species. The presence of male lions increased the probability of an interspecific interaction but decreased the likelihood of hyenas obtaining or retaining possession of the food. Hyena mobbing rates were highest at fresh kills, but lower when adult male lions were present. The occurrence of mobbing was predicted by an increase in the number of hyenas present. Whether or not mobbing resulted in acquisition of food from lions was predicted by an increase in the number of mobs formed by the hyenas present, suggesting that cooperation among hyenas enhances their fitness.

Ligand specificity of MobR, a transcriptional regulator for the 3-hydroxybenzoate hydroxylase gene of Comamonas testosteroni KH122-3s

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshida, Mariko; Hiromoto, Takeshi; Hosokawa, Keiichi

2007-10-19

MobR from Comamonas testosteroni KH122-3s is a member of the MarR family of transcriptional regulators and functions as a repressor for the mobA gene that encodes a 3-hydroxybenzoate 4-hydroxylase. 3-Hydroxybenzoate binds to MobR as a ligand, resulting in an efficient induction of mobA. Various 3-hydroxybenzoate analogues were examined for their inducibilities using the mobA::lacZ transcriptional fusion system. {beta}-Galactosidase was induced by the addition of 2,3-dihydroxybenzoate or 3,5-dihydroxybenzoate besides 3-hydroxybenzoate, suggesting that the hydroxyl group at position 3 is critical in addition to the carboxyl group on the aromatic ring. A gel mobility-shift assay also showed that MobR was released frommore » the target DNA in the presence of these compounds. Circular dichroism studies demonstrated that MobR adopted two conformational states corresponding to the 3-hydroxybenzoate-bound and unbound forms. Other ligands also induced the structural change as well; however, the tertiary structures of converted forms were different from those by 3-hydroxybenzoate.« less

Improved methane removal in exhaust gas from biogas upgrading process using immobilized methane-oxidizing bacteria.

PubMed

Sun, Meng-Ting; Yang, Zhi-Man; Fu, Shan-Fei; Fan, Xiao-Lei; Guo, Rong-Bo

2018-05-01

Methane in exhaust gas from biogas upgrading process, which is a greenhouse gas, could cause global warming. The biofilter with immobilized methane-oxidizing bacteria (MOB) is a promising approach for methane removal, and the selections of inoculated MOB culture and support material are vital for the biofilter. In this work, five MOB consortia were enriched at different methane concentrations. The MOB-20 consortium enriched at the methane concentration of 20.0% (v/v) was then immobilized on sponge and two particle sizes of volcanic rock in biofilters to remove methane in exhaust gas from biogas upgrading process. Results showed that the immobilized MOB performed more admirable methane removal capacity than suspended cells. The immobilized MOB on sponge reached the highest methane removal efficiency (RE) of 35%. The rough surface, preferable hydroscopicity, appropriate pore size and particle size of support material might favor the MOB immobilization and accordingly methane removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

[A range of mobbing among female and male nurses employed in the Szczecin hospitals].

PubMed

Kunecka, Danuta; Kamińska, Magdalena; Karakiewicz, Beata

2008-01-01

Workplace mobbing, a particular type of conflict, has recently been recognized as one of the factors of occupational hazard, resulting from the social environment. Health service workers belong to occupational groups, which are particularly exposed to mobbing. Moreover, changes in the structure of medical labor market make that nurses often work under strong pressure and thus the phenomenon of mobbing becomes even more intensified. The aim of this study was to analyze the incidence of mobbing in the nursing stuff employed in the Szczecin hospitals. The method of diagnostic poll was based on a questionnaire, developed and distributed among 1578 respondents employed in hospitals in Szczecin. Of this number, 1261 correctly completed questionnaires were statistically analyzed. The results showed that the phenomenon of mobbing is actually common in the nursing occupational group (18.6%). The majority (40%) of respondents indicated a superior as a mobber (torturer). The high incidence of mobbing observed in the nursing occupational group may evidence that Human Resource Management (HRM) processes are not perfect.

[Mobbing and working environment: towards an organizational prevention].

PubMed

Bosco, Maria Giuseppina; Salerno, Silvana

2004-01-01

Psychological violence in the workplaces is increasing and the Italian national health service and trade unions are mostly involved in single cases of diagnosis strategy. To analyse published mobbing cases using a mobbing prevention approach that takes account of the main civil rights violation in mobbing actions. 25 cases were analysed in order to identify the type of mobbing, gender, the professional position and the main civil rights that were violated. Seven main civil rights had been violated in the 25 mobbing cases: health, work, professional skills, equal treatment, legality, diversity, dignity. Men working in unhealthy conditions, mostly due to unhealthy working environments, were forced to leave under the pressure of moral violence. In women, equal treatment and diversity were the main rights that were violated. Co-worker support was absent in all cases. A civil rights assessment to prevent mobbing is considered. Italian legislation, particularly the Civil Code, can be the legislation key for prevention, with the employer responsible for providing a violence-free environment as indicated in European Directive 626/94.

Frequency References for Gravitational Wave Missions

NASA Technical Reports Server (NTRS)

Preston, Alix; Thrope, J. I.; Donelan, D.; Miner, L.

2012-01-01

The mitigation of laser frequency noise is an important aspect of interferometry for LISA-like missions. One portion of the baseline mitigation strategy in LISA is active stabilization utilizing opto-mechanical frequency references. The LISA optical bench is an attractive place to implement such frequency references due to its environmental stability and its access to primary and redundant laser systems. We have made an initial investigation of frequency references constructed using the techniques developed for the LISA and LISA Pathfinder optical benches. Both a Mach-Zehnder interferometer and triangular Fabry-Perot cavity have been successfully bonded to a Zerodur baseplate using the hydroxide bonding method. We will describe the construction of the bench along with preliminary stability results.

[Dysfunctional workplace organization and mobbing. 4 representative cases].

PubMed

Albini, Elisa; Benedetti, Laura; Giordano, S; Punzi, Silvia; Cassitto, Maria Grazia

2003-01-01

Stress and psychological harassment at work are increasing worldwide, according to International Agencies (European Community, NIOSH) and to most authors. To describe typical working situations responsible for distress and mobbing, with the aim of early diagnosis and effectiveness of therapy and rehabilitation. Four cases are reported as representative of dysfunctional organization producing distress and pathology or inducing mobbing behavior or mobbing without clear organization responsibilities. In all cases dysfunctional organization appeared to have played a significant role even though not always a direct one. Also, common characteristics were highlighted in the three cases where mobbing was recognized.

[Mobbing, coping and narcisism: reflections in the light of a clinical experience].

PubMed

Ziliotto, G

2008-01-01

The term "mobbing" has today erroneously come to be a huge general recepticle for all the conflicts and interpersonal problems breaking out in the work environment. The author, who collaborates as clinical psychologist in an anti-mobbing network, shows that frequently events at work and personality structures are closely connected. In particular, attention to the modes of coping becomes a fundamental aspect for the diagnosis of mobbing. If psychic distress has gradually moved from a neurotic basis to a more preponderantly narcissistic pathology, the author underlines that precisely narcissistic pathologies may be correlated to the vast container of mobbing.

A review of electrochemiluminescence (ECL) in and for microfluidic analytical devices.

PubMed

Kirschbaum, Stefanie E K; Baeumner, Antje J

2015-05-01

The concept and realization of microfluidic total analysis systems (microTAS) have revolutionized the analytical process by integrating the whole breadth of analytical techniques into miniaturized systems. Paramount for efficient and competitive microTAS are integrated detection strategies, which lead to low limits of detection while reducing the sample volume. The concept of electrochemiluminescence (ECL) has been intriguing ever since its introduction based on Ru(bpy)3 (2+) by Tokel and Bard [1] (J Am Chem Soc 1853:2862-2863, 1972), especially because of its immense sensitivity, nonexistent auto-luminescent background signal, and simplicity in experimental design. Therefore, integrating ECL detection into microTAS is a logical consequence to achieve simple, yet highly sensitive, sensors. However, published microanalytical devices employing ECL detection focus in general on traditional ECL chemistry and have yet to take advantage of advances made in standard bench-top ECL strategies. This review will therefore focus on the most recent advancements in microfluidic ECL approaches, but also evaluate the potential impact of bench-top ECL research progress that would further improve performance and lower limits of detection of micro analytical ECL systems, ensuring their desirability as detection principle for microTAS applications.

Mobbing in the workplace by peers and managers: mobbing experienced by nurses working in healthcare facilities in Turkey and its effect on nurses.

PubMed

Yildirim, Aytolan; Yildirim, Dilek

2007-08-01

This research was conducted as a descriptive and cross-sectional study with the purpose of determining the mobbing experienced by nurses who work in healthcare facilities in Turkey, its emotional, social and physiological effects on the nurses and the actions that the individuals take to escape from the mobbing. The term 'mobbing', which includes workplace terrorizing, pressure, frightening, belittling and psycho-terror, is defined as the presence of systematic, directed, unethical communication and antagonistic behaviour by one or more individuals. These actions that occur frequently and continue for a long time are the most serious and effective causes of workplace stress. The person who is the target of the mobbing is left without help, without protection and alone in the workplace. Individuals who are exposed to psychological abuse experience physiological, psychological and social problems that are related to high levels of stress and anxiety. The research participants were 505 nurses of whom 325 (64%) worked in public and 180 (36%) in private hospitals. All of the participants were female. A questionnaire developed by the researchers in the light of information in the literature was used for data collection and had four sections including the participants' demographic characteristics and questions asking about mobbing behaviours, reaction to mobbing incidents and actions taken to escape from the mobbing. The data were collected between October and December 2005 by giving an envelope to the participants and then collecting the responses in the closed envelope. The overwhelming majority (86.5%) of the nurses participating in the research reported facing mobbing behaviour in the workplace in the last 12 months. The nurses working at private hospitals faced statistically significantly more mobbing behaviours than those at public hospitals (p

Mob/oriT, a mobilizable site-specific recombination system for unmarked genetic manipulation in Bacillus thuringiensis and Bacillus cereus.

PubMed

Wang, Pengxia; Zhu, Yiguang; Zhang, Yuyang; Zhang, Chunyi; Xu, Jianyi; Deng, Yun; Peng, Donghai; Ruan, Lifang; Sun, Ming

2016-06-10

Bacillus thuringiensis and Bacillus cereus are two important species in B. cereus group. The intensive study of these strains at the molecular level and construction of genetically modified bacteria requires the development of efficient genetic tools. To insert genes into or delete genes from bacterial chromosomes, marker-less manipulation methods were employed. We present a novel genetic manipulation method for B. thuringiensis and B. cereus strains that does not leave selection markers. Our approach takes advantage of the relaxase Mob02281 encoded by plasmid pBMB0228 from Bacillus thuringiensis. In addition to its mobilization function, this Mob protein can mediate recombination between oriT sites. The Mob02281 mobilization module was associated with a spectinomycin-resistance gene to form a Mob-Spc cassette, which was flanked by the core 24-bp oriT sequences from pBMB0228. A strain in which the wild-type chromosome was replaced with the modified copy containing the Mob-Spc cassette at the target locus was obtained via homologous recombination. Thus, the spectinomycin-resistance gene can be used to screen for Mob-Spc cassette integration mutants. Recombination between the two oriT sequences mediated by Mob02281, encoded by the Mob-Spc cassette, resulted in the excision of the Mob-Spc cassette, producing the desired chromosomal alteration without introducing unwanted selection markers. We used this system to generate an in-frame deletion of a target gene in B. thuringiensis as well as a gene located in an operon of B. cereus. Moreover, we demonstrated that this system can be used to introduce a single gene or an expression cassette of interest in B. thuringiensis. The Mob/oriT recombination system provides an efficient method for unmarked genetic manipulation and for constructing genetically modified bacteria of B. thuringiensis and B. cereus. Our method extends the available genetic tools for B. thuringiensis and B. cereus strains.

Innovative lightweight substrate for stable optical benches and mirrors

NASA Astrophysics Data System (ADS)

Rugi Grond, E.; Herren, A.; Mérillat, S.; Fermé, J. J.

2017-11-01

High precision space optics, such as spectrometers, relay optics, and filters, require ultra stable, lightweight platforms. These equipped platforms have on one side to survive the launch loads, on the other side they have to maintain their stability also under the varying thermal loads occurring in space. Typically such platforms have their equipment (prisms, etalons, beam expanders, etc.) mounted by means of classical bonding, hydro-catalytic bonding or optical contacting. Therefore such an optical bench requires to provide an excellent flatness, minimal roughness and is usually made of the same material as the equipment it carries (glass, glass ceramics). For space systems, mass is a big penalty, therefore such optical platforms are in most cases light weighted by means of machining features (i.e. pockets). Besides of being not extremely mass efficient, such pockets reduce the load carrying capability of the base material significantly. The challenge for Oerlikon Space, in this context, was to develop, qualify and deliver such optical benches, providing a substantial mass reduction compared to actual light weighted systems, while maintaining most of the full load carrying capacity of the base material. Additionally such a substrate can find an attractive application for mirror substrates. The results of the first development and of the first test results will be presented.

Influence of Dissipative Particle Dynamics parameters and wall models on planar micro-channel flows

NASA Astrophysics Data System (ADS)

Wang, Yuyi; She, Jiangwei; Zhou, Zhe-Wei; microflow Group Team

2017-11-01

Dissipative Particle Dynamics (DPD) is a very effective approach in simulating mesoscale hydrodynamics. The influence of solid boundaries and DPD parameters are typically very strong in DPD simulations. The present work studies a micro-channel Poisseuille flow. Taking the neutron scattering experiment and molecular dynamics simulation result as bench mark, the DPD results of density distribution and velocity profile are systematically studied. The influence of different levels of coarse-graining, the number densities of wall and fluid, conservative force coefficients, random and dissipative force coefficients, different wall model and reflective boundary conditions are discussed. Some mechanisms behind such influences are discussed and the artifacts in the simulation are identified with the bench mark. Chinese natural science foundation (A020405).

Mobbing, stress, and work ability index among physicians in Bosnia and Herzegovina: survey study.

PubMed

Pranjić, Nurka; Males-Bilić, Ljiljana; Beganlić, Azijada; Mustajbegović, Jadranka

2006-10-01

To assess the frequency of reported mobbing and the association among mobbing, working environment factors, stress, health outcome, personality type, and work ability index in a sample of physicians in Bosnia and Herzegovina. We conducted a questionnaire survey using a validated self-reported questionnaire among 511 physicians in national health sector of Bosnia and Herzegovina. The questions covered five major categories of mobbing behavior. Characteristics of the work, perceived work environment and its effects, stress, health, and satisfaction with work and life were assessed by the standardized abridged form of Occupational Stress Questionnaire (OSQ). A standardized questionnaire Work Ability Index (WAI) was used to determine the relation between mobbing and work ability. Of 511 surveyed physicians, 387 (76%) physicians self-reported mobbing behavior in the working environment and 136 (26%) was exposed to persistent mobbing. More than a half of the physicians experienced threats to their professional status and almost a half felt isolated. Logistic regression analysis showed that lack of motivation, loss of self-esteem, loss of confidence, fatigue, and depressiveness were significantly associated with lack of support from colleagues. Intention to leave work was associated with lack of support from colleagues (OR 2.3, 95% CI, 1.065-3.535; t =4.296, P =0.003) and lack of support from superiors (OR 1.526, 95% CI, 0.976-2.076; t =5.753; P =0.001). Isolation or exclusion and threats to professional status were predictors for mental health symptoms. Persistent mobbing experience was a significant predictor for sick leave. Exposure to persistent threat to professional status and isolation or exclusion as forms of mobbing are associated with mental health disturbances and lack of self-esteem and confidence. Setting up a system of support for physicians exposed to mobbing may have important benefits.

Effects of avian mobbing on roost use and diet of powerful owls, Ninox strenua

PubMed

Pavey; Smyth

1998-02-01

We observed the species and numbers of mobbing birds and their effects on a large, nocturnal, bird-eating predator, the powerful owl, together with the pattern of owl predation on mobbing and non-mobbing species. Owls were mobbed on 35 occasions by seven of 44 species of forest birds at a site composed of open forest (88% by area) and rainforest (12%). The majority of bouts involved individuals of a single species, although mixed groups were observed on nine occasions. Regular mobbers were between 4 and 26% of the owls' body weight. Owls abandoned their daytime roosts during 20% of bouts and responded by calling or actively monitoring mobbers during 54% of bouts. Mobbing appeared to explain why owls roosted in rainforest significantly more often than expected by its availability, mobbing being significantly less frequent in rainforest than in open forest. Only one mobbing species regularly occupied rainforest and the canopy of roosts in rainforest was denser than that in open forest, thus reducing the chances of an owl being detected by potential mobbers. Twelve species of forest birds were within the range of prey size of the powerful owl (75-800 g): six were mobbers and six non-mobbers. The frequency of owl predation on non-mobbers was 8.75 times that on mobbers. The species in this study took a high risk by mobbing a very large predator, but benefited by greatly reducing their chances of predation.Copyright 1998 The Association for the Study of Animal Behaviour.

The Relationship Between Sociodemographic Characteristics, Work Conditions, and Level of "Mobbing" of Health Workers in Primary Health Care.

PubMed

Picakciefe, Metin; Acar, Gulcihan; Colak, Zehra; Kilic, Ibrahim

2015-06-19

Mobbing is a type of violence which occurs in workplaces and is classified under the community violence subgroup of interpersonal violence. The aim of this study is to examine health care workers who work in primary health care in the city of Mugla and to determine whether there is a relationship between sociodemographic characteristics, work conditions, and their level of mobbing. A cross-sectional analysis has been conducted in which 130 primary health care workers were selected. Of the 130, 119 health workers participated, yielding a response rate of 91.5%; 83.2% of health workers are female, 42.9% are midwives, 27.7% are nurses, and 14.3% are doctors. In all, 31.1% of health workers have faced with "mobbing" in the last 1 year, and the frequency of experiencing "mobbing" of those 48.6% of them is 1 to 3 times per year. A total of 70.3% of those who apply "mobbing" are senior health workers, and 91.9% are female. The frequency of encountering with "mobbing" was found significantly in married health workers, in those 16 years and above according to examined total working time, in those who have psychosocial reactions, and in those who have counterproductive behaviors. It has been discovered that primary health care workers have high prevalence of "mobbing" exposure. To avoid "mobbing" at workplace, authorities and responsibilities of all employees have to be clearly determined. © The Author(s) 2015.

Verification of polarising optics for the LISA optical bench.

PubMed

Dehne, Marina; Tröbs, Michael; Heinzel, Gerhard; Danzmann, Karsten

2012-12-03

The Laser Interferometer Space Antenna (LISA) is a space-based interferometric gravitational wave detector. In the current baseline design for the optical bench, the use of polarising optics is foreseen to separate optical beams. Therefore it is important to investigate the influence of polarising components on the interferometer sensitivity and validate that the required picometre stability in the low-frequency band (1 mHz - 1 Hz) is achievable. This paper discusses the design of the experiment and the implemented stabilisation loops. A displacement readout fulfilling the requirement in the whole frequency band is presented. Alternatively, we demonstrate improvement of the noise performance by implementing various algorithms in data post-processing, which leads to an additional robustness for the LISA mission.

78 FR 29120 - Notice of Intent To Prepare an Environmental Impact Statement for the Main Operating Base 2 (MOB...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... Operating Base 2 (MOB-2) for the Beddown of KC-46A Tanker Aircraft AGENCY: Department of the Air Force, DOD... Operating Base 2 (MOB-2) for the beddown of KC-46A tanker aircraft. The EIS will assess the potential... infrastructure, and personnel in support of the MOB-2 at existing Air National Guard (ANG) installations within...

Understory avifauna exhibits altered mobbing behavior in tropical forest degraded by selective logging.

PubMed

Hua, Fangyuan; Sieving, Kathryn E

2016-11-01

In understanding the impacts of selective logging on biodiversity, relatively little is known about the critical behavioral link between altered forest conditions and population persistence. Predator-mobbing is a widespread anti-predator behavior in birds that expresses a well-known trade-off influencing prey survival under predation risk. Here, we ask whether the predator-mobbing behavior of understory forest birds is altered by selective logging and associated forest structural changes in the highly endangered lowland rainforest of Sumatra. At four study sites spanning a gradient of logging-induced forest degradation, we used standardized mobbing and owl call playbacks with predator model presentation to elicit the predator-mobbing behavior of understory prey birds, compared birds' mobbing intensity across sites, and related variation in this intensity to forest vegetation structure. We found that selective logging altered birds' predator-mobbing intensity (measured by behavioral conspicuousness and propensity to approach the predator) as well as forest structure, and that vegetative changes to canopy and understory were correlated with contrasting responses by the two major bird foraging guilds, gleaning versus flycatching birds. We additionally discuss the implications of our findings for further hypothesis testing pertaining to the impacts of selective logging on the ecological processes underlying prey mobbing behavior, particularly with regards to predator-prey interactions and prey accruement of energy reserves.

Mobbing in Schools and Hospitals in Uruguay: Prevalence and Relation to Loss of Status.

PubMed

Buunk, Abraham P; Franco, Silvia; Dijkstra, Pieternel; Zurriaga, Rosario

2016-01-19

In the present study in secondary schools and hospitals in Uruguay (N = 187), we examined the relationship between feeling the victim of mobbing and a perceived loss of status. Nearly all forms of mobbing were more prevalent among hospital employees than among school employees. Among hospital employees, 40.4%, and among school employees, 23.9% reported being the victim of mobbing at least once a week. Being the victim of mobbing was, in both hospitals and schools, more prevalent among older employees, and in hospitals, among employees who were more highly educated and who had been employed for a longer time. Men and women did not differ in reporting that one was a victim of mobbing, but men reported more perceived loss of status than women. However, among women, being the victim of mobbing was much more strongly related to experiencing a loss of status than among men. Several explanations for this gender difference and the practical and theoretical implications of the results are discussed. © The Author(s) 2016.

Dual-Band Optical Bench for Terahertz Radiometer for Outer Planet Atmospheres (TROPA)

NASA Technical Reports Server (NTRS)

Schlecht, Erich; Jamnejad, Vahraz

2012-01-01

We have developed a wide-band dual frequency spectrometer for use in deep space planetary atmospheric spectroscopy. The instrument uses a dual-band architecture, both to be able to observe spectral lines from a wide range of atmospheric species, and to allow a higher precision retrieval of temperature/pressure/partial pressure and wind profiles. This dual-band approach requires a new design for the optical bench to couple both frequencies into their respective receivers.

Asymmetries in commitment in an avian communication network.

PubMed

Randler, Christoph; Vollmer, Christian

2013-02-01

Mobbing of predators occurs within a conspecific and heterospecific context but has not been quantified within the framework of a communication network and analysed with respect to heterospecific reciprocity. Here, we used playbacks of mobbing calls to show that mobbing is unequally distributed within a community of deciduous forest birds. Five species (great tit Parus major, blue tit Cyanistes caeruleus, marsh tit Poecile palustris, nuthatch Sitta europaea and chaffinch Fringilla coelebs) responded to each other's playbacks of mobbing calls. Commitment to mob was measured by minimum distance, response latency and uttering of calls. Commitment was higher when conspecific calls were broadcast. Yet, responses to heterospecific calls were significantly different between the five species. Chaffinches had the lowest commitment, and blue tits tended to have the highest. The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community.

Asymmetries in commitment in an avian communication network

NASA Astrophysics Data System (ADS)

Randler, Christoph; Vollmer, Christian

2013-02-01

Mobbing of predators occurs within a conspecific and heterospecific context but has not been quantified within the framework of a communication network and analysed with respect to heterospecific reciprocity. Here, we used playbacks of mobbing calls to show that mobbing is unequally distributed within a community of deciduous forest birds. Five species (great tit Parus major, blue tit Cyanistes caeruleus, marsh tit Poecile palustris, nuthatch Sitta europaea and chaffinch Fringilla coelebs) responded to each other's playbacks of mobbing calls. Commitment to mob was measured by minimum distance, response latency and uttering of calls. Commitment was higher when conspecific calls were broadcast. Yet, responses to heterospecific calls were significantly different between the five species. Chaffinches had the lowest commitment, and blue tits tended to have the highest. The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community.

Stress and nurses' horizontal mobbing: moderating effects of group identity and group support.

PubMed

Topa, Gabriela; Moriano, Juan A

2013-01-01

Horizontal mobbing is a process of systematic and repeated aggression towards a worker by coworkers. Among others, stress has been pointed out as one of the antecedents that favors the onset of horizontal mobbing, whereas group support to the target could act as a buffer. Moreover, the social identity approach emphasizes that group identity is an antecedent of group support. This study explores the interaction of group support and group identity in the explanation of horizontal mobbing in a sample (N = 388) of registered nurses and licensed practical nurses employed at two large hospitals in Madrid and Navarre (Spain). The results show that stress is positively associated to horizontal mobbing, whereas group support and group identity were negative predictors of horizontal mobbing. Furthermore, the combination of low group identity and low group support precipitated HM among nurses. Copyright © 2013 Elsevier Inc. All rights reserved.

Functional properties and structural requirements of the plasmid pMV158-encoded MobM relaxase domain.

PubMed

Fernández-López, Cris; Pluta, Radoslaw; Pérez-Luque, Rosa; Rodríguez-González, Lorena; Espinosa, Manuel; Coll, Miquel; Lorenzo-Díaz, Fabián; Boer, D Roeland

2013-07-01

A crucial element in the horizontal transfer of mobilizable and conjugative plasmids is the relaxase, a single-stranded endonuclease that nicks the origin of transfer (oriT) of the plasmid DNA. The relaxase of the pMV158 mobilizable plasmid is MobM (494 residues). In solution, MobM forms a dimer through its C-terminal domain, which is proposed to anchor the protein to the cell membrane and to participate in type 4 secretion system (T4SS) protein-protein interactions. In order to gain a deeper insight into the structural MobM requirements for efficient DNA catalysis, we studied two endonuclease domain variants that include the first 199 or 243 amino acid residues (MobMN199 and MobMN243, respectively). Our results confirmed that the two proteins behaved as monomers in solution. Interestingly, MobMN243 relaxed supercoiled DNA and cleaved single-stranded oligonucleotides harboring oriTpMV158, whereas MobMN199 was active only on supercoiled DNA. Protein stability studies using gel electrophoresis and mass spectrometry showed increased susceptibility to degradation at the domain boundary between the N- and C-terminal domains, suggesting that the domains change their relative orientation upon DNA binding. Overall, these results demonstrate that MobMN243 is capable of nicking the DNA substrate independently of its topology and that the amino acids 200 to 243 modulate substrate specificity but not the nicking activity per se. These findings suggest that these amino acids are involved in positioning the DNA for the nuclease reaction rather than in the nicking mechanism itself.

Diversity of Cultivable Methane-Oxidizing Bacteria in Microsites of a Rice Paddy Field: Investigation by Cultivation Method and Fluorescence in situ Hybridization (FISH)

PubMed Central

Dianou, Dayéri; Ueno, Chihoko; Ogiso, Takuya; Kimura, Makoto; Asakawa, Susumu

2012-01-01

The diversity of cultivable methane-oxidizing bacteria (MOB) in the rice paddy field ecosystem was investigated by combined culture-dependent and fluorescence in situ hybridization (FISH) techniques. Seven microsites of a Japanese rice paddy field were the focus of the study: floodwater, surface soil, bulk soil, rhizosphere soil, root, basal stem of rice plant, and rice stumps of previous harvest. Based on pmoA gene analysis and transmission electron microscopy (TEM), four type I, and nine type II MOB isolates were obtained from the highest dilution series of enrichment cultures. The type I MOB isolates included a novel species in the genus Methylomonas from floodwater and this is the first type I MOB strain isolated from floodwater of a rice paddy field. In the type I MOB, two isolates from stumps were closely related to Methylomonas spp.; one isolate obtained from rhizosphere soil was most related to Methyloccocus-Methylocaldum-Methylogaea clade. Almost all the type II MOB isolates were related to Methylocystis methanotrophs. FISH confirmed the presence of both types I and II MOB in all the microsites and in the related enrichment cultures. The study reported, for the first time, the diversity of cultivable methanotrophs including a novel species of type I MOB in rice paddy field compartments. Refining growth media and culture conditions, in combination with molecular approaches, will allow us to broaden our knowledge on the MOB community in the rice paddy field ecosystem and consequently to implement strategies for mitigating CH4 emission from this ecosystem. PMID:22446309

Linking the runoff response at micro-plot and catchment scale following wildfire and terracing, north-central Portugal

NASA Astrophysics Data System (ADS)

Martins, Martinho A. S.; Rial-Rivas, María E.; Machado, Ana I.; Serpa, Dalila; Prats, Sergio A.; Faria, Sílvia R.; Varela, María E. T.; González-Pelayo, Óscar; Keizer, J. Jacob

2015-04-01

Wildfires are known as one of the principal natural hazards affecting the Mediterranean region. This includes Portugal, where wildfires have affected some 100.000 ha of rural lands each year. The effects of wildfires on runoff generation and/or the associated soil (fertility) losses have been studied in Portugal for more than two decades. Some of these studies have reported strong and sometimes extreme hydrological responses in recently burnt areas. Forestry operations in such areas have increasingly come to include bench terracing in preparation of new eucalypt plantations. The hydrological impacts of bench terracing, however, have received little research attention so far and the few existing publications are limited to small spatial scales. The construction of terraces is commonly considered an effective practice for soil conservation on steep slopes, having been applied by mankind since early history. Nonetheless, the present authors have measured high rates of splash as well as inter-rill erosion on recently constructed terraces, and have regularly observed rill formation, including on forest tracks which typically constitute an extensive network in such bench terraced plantations. The present study was carried out in a 29-ha forest catchment in north-central Portugal that was burnt by a wildfire during the summer of 2010, logged during early winter 2010/11, and then bench terraced with bulldozers during late winter 2011, some 6 months after the wildfire. The catchment outlet was instrumented immediately after the fire with an automatic hydrometric station comprising two subsequent flumes with maximum discharge capacities of 120 and 1700 l sec-1. Within the catchment, rainfall was measured using several automatic and storage gauges and overland flow was monitored on two contrasting slopes using 3 micro-plots of approximately 0.25m2 on each slope.Overland flow was measured at 1- to 2-weekly intervals during the hydrological years of 2010/11 and 2011/12, i.e. during the first six months after the wildfire but before the bench terracing and during the subsequent 18 months. While data analysis is still ongoing, preliminary results suggested that bench terracing had a greater impact on runoff generation than the wildfire itself, especially at the micro-plot scale

System for Measuring Flexing of a Large Spaceborne Structure

NASA Technical Reports Server (NTRS)

Scharf, Daniel; Kuhnert, Andreas; Kovalik, Joseph; Hadaegh, Fred; Shaddock, Daniel

2008-01-01

An optoelectronic metrology system is used for determining the attitude and flexing of a large spaceborne radar antenna or similar structure. The measurements are needed for accurate pointing of the antenna and correction and control of the phase of the radar signal wavefront. The system includes a dual-field-of-view star tracker; a laser ranging unit (LRU) and a position-sensitive-detector (PSD)-based camera mounted on an optical bench; and fiducial targets at various locations on the structure. The fiducial targets are illuminated in sequence by laser light coupled via optical fibers. The LRU and the PSD provide measurements of the position of each fiducial target in a reference frame attached to the optical bench. During routine operation, the star tracker utilizes one field of view and functions conventionally to determine the orientation of the optical bench. During operation in a calibration mode, the star tracker also utilizes its second field of view, which includes stars that are imaged alongside some of the fiducial targets in the PSD; in this mode, the PSD measurements are traceable to star measurements.

Does participative leadership reduce the onset of mobbing risk among nurse working teams?

PubMed

Bortoluzzi, Guido; Caporale, Loretta; Palese, Alvisa

2014-07-01

To evaluate the advancement of knowledge on the impact of an empowering leadership style on the risk of mobbing behaviour among nurse working teams. The secondary aim was to evaluate, along with leadership style, the contribution of other organisational- and individual-related mobbing predictors. The style of leadership in reducing the onset of mobbing risk in nurse working teams still remains a matter of discussion. Nurse working teams are particularly affected by mobbing and studies exploring individual and organisational inhibiting/modulating factors are needed. An empirical study involving 175 nurses of various public hospital corporations in northern Italy. Data were collected via structured and anonymous questionnaires and analysed through a logistic regression. Organisational, individual and participative leadership variables explained 33.5% (P < 0.01) of variance in the onset of mobbing. Two predictive factors emerged: a participative leadership enacted by nursing managers and the nursing shortage as perceived by clinical nurses. Results confirmed that the contribution made by a participative leadership style in attenuating the onset of mobbing risk in working teams was significant. A participative leadership style adopted by the nurse manager allows for the reduction of tensions in nurse working teams. However, mobbing remains a multifaceted phenomenon that is difficult to capture in its entirety and the leadership style cannot be considered as a panacea for resolving this problem in nurse working teams. © 2013 John Wiley & Sons Ltd.

Academic mobbing: hidden health hazard at workplace.

PubMed

Khoo, Sb

2010-01-01

Academic mobbing is a non-violent, sophisticated, 'ganging up' behaviour adopted by academicians to "wear and tear" a colleague down emotionally through unjustified accusation, humiliation, general harassment and emotional abuse. These are directed at the target under a veil of lies and justifications so that they are "hidden" to others and difficult to prove. Bullies use mobbing activities to hide their own weaknesses and incompetence. Targets selected are often intelligent, innovative high achievers, with good integrity and principles. Mobbing activities appear trivial and innocuous on its own but the frequency and pattern of their occurrence over long period of time indicates an aggressive manipulation to "eliminate" the target. Mobbing activities typically progress through five stereotypical phases that begins with an unsolved minor conflict between two workers and ultimately escalates into a senseless mobbing whereby the target is stigmatized and victimized to justify the behaviours of the bullies. The result is always physical, mental, social distress or illness and, most often, expulsion of target from the workplace. Organizations are subjected to great financial loss, loss of key workers and a tarnished public image and reputation. Public awareness, education, effective counselling, establishment of anti-bullying policies and legislations at all levels are necessary to curb academic mobbing. General practitioners (GPs) play an important role in supporting patients subjected to mental and physical health injury caused by workplace bullying and mobbing.

The relationship between burnout and mobbing among hospital managers.

PubMed

Karsavuran, Seda; Kaya, Sıdıka

2017-05-01

Mobbing and burnout can cause serious consequences, especially for health workers and managers. Level of burnout and exposure to mobbing may trigger each other. There is a need to conduct additional and specific studies on the topic to develop some strategies. The purpose of this study is to determine the relationship between level of burnout and exposure to mobbing of the managers (head physician, assistant head physician, head nurse, assistant head nurse, administrator, assistant administrator) at the Ministry of Health hospitals. The "Leymann Inventory of Psychological Terrorization" scale was used to measure the level of exposure to mobbing and the "Maslach Burnout Inventory" scale was used to measure the level of burnout of hospital managers. The relationship between level of burnout and exposure to mobbing was analyzed by Pearson's Correlation Analysis. Participants and research context: The population of this study included managers (454 managers) at the Ministry of Health hospitals in the metropolitan area of Ankara between September 2010 and May 2011. All the managers were tried to conduct, but some managers did not want to reply to the questionnaire and some managers were not found at their workplace. Consequently, using a convenience sampling, 54% of the managers replied to the questionnaire (244 managers). Ethical consideration: The approval of the study was granted by the Ministry of Health in Turkey. Furthermore, the study was evaluated and accepted by the Education, Planning and Coordination Council of one of the education and research hospitals in the study. Positive relationships were found among each subdimension of the mobbing and emotional exhaustion and depersonalization. A negative relationship was found between each subdimension of the mobbing and personal accomplishment. In hospitals, by detecting mobbing actions, burnout may be prevented. Exposure to mobbing and burnout could be a serious problem for head nurses who are responsible for both the performance of the nurses and organization. Additionally, head nurses who are faced with mobbing and burnout are more likely to provide suboptimal services which could potentially result in negative outcomes. Therefore, this study draws attention to the importance of preventing these attitudes in the organization.

Design of a Test Bench for Intraocular Lens Optical Characterization

NASA Astrophysics Data System (ADS)

Alba-Bueno, Francisco; Vega, Fidel; Millán, María S.

2011-01-01

The crystalline lens is the responsible for focusing at different distances (accommodation) in the human eye. This organ grows throughout life increasing in size and rigidity. Moreover, due this growth it loses transparency through life, and becomes gradually opacified causing what is known as cataracts. Cataract is the most common cause of visual loss in the world. At present, this visual loss is recoverable by surgery in which the opacified lens is destroyed (phacoemulsification) and replaced by the implantation of an intraocular lens (IOL). If the IOL implanted is mono-focal the patient loses its natural capacity of accommodation, and as a consequence they would depend on an external optic correction to focus at different distances. In order to avoid this dependency, multifocal IOLs designs have been developed. The multi-focality can be achieved by using either, a refractive surface with different radii of curvature (refractive IOLs) or incorporating a diffractive surface (diffractive IOLs). To analyze the optical quality of IOLs it is necessary to test them in an optical bench that agrees with the ISO119679-2 1999 standard (Ophthalmic implants. Intraocular lenses. Part 2. Optical Properties and Test Methods). In addition to analyze the IOLs according to the ISO standard, we have designed an optical bench that allows us to simulate the conditions of a real human eye. To do that, we will use artificial corneas with different amounts of optical aberrations and several illumination sources with different spectral distributions. Moreover, the design of the test bench includes the possibility of testing the IOLs under off-axis conditions as well as in the presence of decentration and/or tilt. Finally, the optical imaging quality of the IOLs is assessed by using common metrics like the Modulation Transfer Function (MTF), the Point Spread Function (PSF) and/or the Strehl ratio (SR), or via registration of the IOL's wavefront with a Hartmann-Shack sensor and its analysis through expansion in Zernike polynomials.

Missing Link: Bayesian detection and measurement of intermediate-mass black-hole binaries

NASA Astrophysics Data System (ADS)

Graff, Philip B.; Buonanno, Alessandra; Sathyaprakash, B. S.

2015-07-01

We perform Bayesian analysis of gravitational-wave signals from nonspinning, intermediate-mass black-hole binaries (IMBHBs) with observed total mass, Mobs, from 50 M⊙ to 500 M⊙ and mass ratio 1-4 using advanced LIGO and Virgo detectors. We employ inspiral-merger-ringdown waveform models based on the effective-one-body formalism and include subleading modes of radiation beyond the leading (2,2) mode. The presence of subleading modes increases signal power for inclined binaries and allows for improved accuracy and precision in measurements of the masses as well as breaking of degeneracies in distance, orientation and polarization. For low total masses, Mobs≲50 M⊙ , for which the inspiral signal dominates, the observed chirp mass Mobs=Mobsη3 /5 (η being the symmetric mass ratio) is better measured. In contrast, as increasing power comes from merger and ringdown, we find that the total mass Mobs has better relative precision than Mobs. Indeed, at high Mobs (≥300 M⊙ ), the signal resembles a burst and the measurement thus extracts the dominant frequency of the signal that depends on Mobs. Depending on the binary's inclination, at signal-to-noise ratio (SNR) of 12, uncertainties in Mobs can be as large as ˜20 - 25 % while uncertainties in Mobs are ˜50 - 60 % in binaries with unequal masses (those numbers become ˜17 % vs. ˜22 % in more symmetric mass-ratio binaries). Although large, those uncertainties in Mobs will establish the existence of IMBHs. We find that effective-one-body waveforms with subleading modes are essential to confirm a signal's presence in the data, with calculated Bayesian evidences yielding a false alarm probability below 10-5 for SNR ≳9 in Gaussian noise. Our results show that gravitational-wave observations can offer a unique tool to observe and understand the formation, evolution and demographics of IMBHs, which are difficult to observe in the electromagnetic window.

Mobbing, Stress, and Work Ability Index among Physicians in Bosnia and Herzegovina: Survey Study

PubMed Central

Pranjić, Nurka; Maleš-Bilić, Ljiljana; Beganlić, Azijada; Mustajbegović, Jadranka

2006-01-01

Aim To assess the frequency of reported mobbing and the association among mobbing, working environment factors, stress, health outcome, personality type, and work ability index in a sample of physicians in Bosnia and Herzegovina. Method We conducted a questionnaire survey using a validated self-reported questionnaire among 511 physicians in national health sector of Bosnia and Herzegovina. The questions covered five major categories of mobbing behavior. Characteristics of the work, perceived work environment and its effects, stress, health, and satisfaction with work and life were assessed by the standardized abridged form of Occupational Stress Questionnaire (OSQ). A standardized questionnaire Work Ability Index (WAI) was used to determine the relation between mobbing and work ability. Results Of 511 surveyed physicians, 387 (76%) physicians self-reported mobbing behavior in the working environment and 136 (26%) was exposed to persistent mobbing. More than a half of the physicians experienced threats to their professional status and almost a half felt isolated. Logistic regression analysis showed that lack of motivation, loss of self-esteem, loss of confidence, fatigue, and depressiveness were significantly associated with lack of support from colleagues. Intention to leave work was associated with lack of support from colleagues (OR 2.3, 95% CI, 1.065-3.535, t = 4.296, P = 0.003) and lack of support from superiors (OR 1.526, 95% CI, 0.976-2.076, t = 5.753; P = 0.001). Isolation or exclusion and threats to professional status were predictors for mental health symptoms. Persistent mobbing experience was a significant predictor for sick leave. Conclusion Exposure to persistent threat to professional status and isolation or exclusion as forms of mobbing are associated with mental health disturbances and lack of self-esteem and confidence. Setting up a system of support for physicians exposed to mobbing may have important benefits. PMID:17042067

Metrology System for a Large, Somewhat Flexible Telescope

NASA Technical Reports Server (NTRS)

Liebe, Carl Christian; Bartman, Randall; Cook, Walter; Craig, William

2009-01-01

A proposed metrology system would be incorporated into a proposed telescope that would include focusing optics on a rigid bench connected via a deployable mast to another rigid bench holding a focal-plane array of photon counting photodetectors. Deformations of the deployable mast would give rise to optical misalignments that would alter the directions (and, hence, locations) of incidence of photons on the focal plane. The metrology system would measure the relative displacement of the focusing- optics bench and the focal-plane array bench. The measurement data would be used in post-processing of the digitized photodetector outputs to compensate for the mast-deformation-induced changes in the locations of incidence of photons on the focal plane, thereby making it possible to determine the original directions of incidence of photons with greater accuracy. The proposed metrology system is designed specifically for the Nuclear Spectroscopic Telescope Array (NuSTAR) a proposed spaceborne x-ray telescope. The basic principles of design and operation are also applicable to other large, somewhat flexible telescopes, both terrestrial and spaceborne. In the NuSTAR, the structural member connecting the optical bench and the photodetector array would be a 10-m-long deployable mast, and there is a requirement to keep errors in measured directions of incidence of photons below 10 arc seconds (3 sigma). The proposed system would include three diode lasers that would be mounted on the focusing-optics bench. For clarity, only one laser is shown in the figure, which is a greatly simplified schematic diagram of the system. Each laser would be aimed at a position-sensitive photodiode that would be mounted on the detector bench alongside the aforementioned telescope photodetector array. The diode lasers would operate at a wavelength of 830 nm, each at a power of 200 mW. Each laser beam would be focused to a spot of .1-mm diameter on the corresponding position-sensitive photodiode. To reduce the effect of sunlight on the measurements, a one-stage light baffle and an 830-nm transmission filter of 10-nm bandwidth would be placed in front of the position- sensitive photodiode. For each metrology reading, the output of the position-sensitive detector would be sampled and digitized twice: once with the lasers turned on, then once with the lasers turned off. The data from these two sets of samples would be subtracted from each other to further reduce the effects of sun glints or other background light sources.

Reciprocal cooperation in avian mobbing: playing nice pays.

PubMed

Wheatcroft, David J; Price, Trevor D

2008-08-01

Unrelated passerine birds often join together while mobbing, a widespread antipredator behavior during which birds harass a predator. Although previous analyses concluded that mobbing could not have evolved via reciprocity, Krams and colleagues' field experiments show that birds preferentially join mobs with neighbors that have aided them previously, suggesting that these birds utilize reciprocity-based strategies involving individual recognition and recollection of previous interactions with others. This implies a level of sophistication in bird communities greater than had previously been realized.

Neural correlates of threat perception: neural equivalence of conspecific and heterospecific mobbing calls is learned.

PubMed

Avey, Marc T; Hoeschele, Marisa; Moscicki, Michele K; Bloomfield, Laurie L; Sturdy, Christopher B

2011-01-01

Songbird auditory areas (i.e., CMM and NCM) are preferentially activated to playback of conspecific vocalizations relative to heterospecific and arbitrary noise. Here, we asked if the neural response to auditory stimulation is not simply preferential for conspecific vocalizations but also for the information conveyed by the vocalization. Black-capped chickadees use their chick-a-dee mobbing call to recruit conspecifics and other avian species to mob perched predators. Mobbing calls produced in response to smaller, higher-threat predators contain more "D" notes compared to those produced in response to larger, lower-threat predators and thus convey the degree of threat of predators. We specifically asked whether the neural response varies with the degree of threat conveyed by the mobbing calls of chickadees and whether the neural response is the same for actual predator calls that correspond to the degree of threat of the chickadee mobbing calls. Our results demonstrate that, as degree of threat increases in conspecific chickadee mobbing calls, there is a corresponding increase in immediate early gene (IEG) expression in telencephalic auditory areas. We also demonstrate that as the degree of threat increases for the heterospecific predator, there is a corresponding increase in IEG expression in the auditory areas. Furthermore, there was no significant difference in the amount IEG expression between conspecific mobbing calls or heterospecific predator calls that were the same degree of threat. In a second experiment, using hand-reared chickadees without predator experience, we found more IEG expression in response to mobbing calls than corresponding predator calls, indicating that degree of threat is learned. Our results demonstrate that degree of threat corresponds to neural activity in the auditory areas and that threat can be conveyed by different species signals and that these signals must be learned.

Novel mobbing strategies of a fish population against a sessile annelid predator.

PubMed

Lachat, Jose; Haag-Wackernagel, Daniel

2016-09-12

When searching for food, foraging fishes expose themselves to hidden predators. The strategies that maximize the survival of foraging fishes are not well understood. Here, we describe a novel type of mobbing behaviour displayed by foraging Scolopsis affinis. The fish direct sharp water jets towards the hidden sessile annelid predator Eunice aphroditois (Bobbit worm). We recognized two different behavioural roles for mobbers (i.e., initiator and subsequent participants). The first individual to exhibit behaviour indicating the discovery of the Bobbit directed, absolutely and per time unit, more water jets than the subsequent individuals that joined the mobbing. We found evidence that the mobbing impacted the behaviour of the Bobbit, e.g., by inducing retraction. S. affinis individuals either mob alone or form mobbing groups. We speculate that this behaviour may provide social benefits for its conspecifics by securing foraging territories for S. affinis. Our results reveal a sophisticated and complex behavioural strategy to protect against a hidden predator.

[Do people with mobbing experience which apply for medical rehabilitation have a peculiar personality?].

PubMed

Kobelt, Axel; Gutenbrunner, Christoph; Schmid-Ott, Gerhard; Schwickerath, Josef; Petermann, Franz

2010-07-01

Recently results find that victims of mobbing place themselves apart because of their personality types. This study deals with the question whether a difference between victims of mobbing and those non victims can be determined as far as depression, fear and personality type is concerned. Anonymous questionnaires including anxiety-, depression- and personalityscales were sent to 1 000 insured whose application for medical rehabilitation had been granted. 25% of the applicants felt they had been mobbed. 60% of the victims suffered from psychic disorders. The values for depression and anxiety and the mark in the personality scale were significantly high. Mobbing is a relatively common problem for patients in rehabilitation which has to be taken seriously. Although it can not be resolved which direction has to be taken by judging cause and effect. It should be checked if there is enough support during medical rehabilitation for the victims of mobbing. Georg Thieme Verlag KG Stuttgart-New York.

Novel mobbing strategies of a fish population against a sessile annelid predator

PubMed Central

Lachat, Jose; Haag-Wackernagel, Daniel

2016-01-01

When searching for food, foraging fishes expose themselves to hidden predators. The strategies that maximize the survival of foraging fishes are not well understood. Here, we describe a novel type of mobbing behaviour displayed by foraging Scolopsis affinis. The fish direct sharp water jets towards the hidden sessile annelid predator Eunice aphroditois (Bobbit worm). We recognized two different behavioural roles for mobbers (i.e., initiator and subsequent participants). The first individual to exhibit behaviour indicating the discovery of the Bobbit directed, absolutely and per time unit, more water jets than the subsequent individuals that joined the mobbing. We found evidence that the mobbing impacted the behaviour of the Bobbit, e.g., by inducing retraction. S. affinis individuals either mob alone or form mobbing groups. We speculate that this behaviour may provide social benefits for its conspecifics by securing foraging territories for S. affinis. Our results reveal a sophisticated and complex behavioural strategy to protect against a hidden predator. PMID:27615670

On-chip infrared sensors: redefining the benefits of scaling

NASA Astrophysics Data System (ADS)

Kita, Derek; Lin, Hongtao; Agarwal, Anu; Yadav, Anupama; Richardson, Kathleen; Luzinov, Igor; Gu, Tian; Hu, Juejun

2017-03-01

Infrared (IR) spectroscopy is widely recognized as a gold standard technique for chemical and biological analysis. Traditional IR spectroscopy relies on fragile bench-top instruments located in dedicated laboratory settings, and is thus not suitable for emerging field-deployed applications such as in-line industrial process control, environmental monitoring, and point-of-care diagnosis. Recent strides in photonic integration technologies provide a promising route towards enabling miniaturized, rugged platforms for IR spectroscopic analysis. It is therefore attempting to simply replace the bulky discrete optical elements used in conventional IR spectroscopy with their on-chip counterparts. This size down-scaling approach, however, cripples the system performance as both the sensitivity of spectroscopic sensors and spectral resolution of spectrometers scale with optical path length. In light of this challenge, we will discuss two novel photonic device designs uniquely capable of reaping performance benefits from microphotonic scaling. We leverage strong optical and thermal confinement in judiciously designed micro-cavities to circumvent the thermal diffusion and optical diffraction limits in conventional photothermal sensors and achieve a record 104 photothermal sensitivity enhancement. In the second example, an on-chip spectrometer design with the Fellgett's advantage is analyzed. The design enables sub-nm spectral resolution on a millimeter-sized, fully packaged chip without moving parts.

Degenerate primer MOB typing of multiresistant clinical isolates of E. coli uncovers new plasmid backbones.

PubMed

Garcillán-Barcia, M Pilar; Ruiz del Castillo, Belén; Alvarado, Andrés; de la Cruz, Fernando; Martínez-Martínez, Luis

2015-01-01

Degenerate Primer MOB Typing is a PCR-based protocol for the classification of γ-proteobacterial transmissible plasmids in five phylogenetic relaxase MOB families. It was applied to a multiresistant E. coli collection, previously characterized by PCR-based replicon-typing, in order to compare both methods. Plasmids from 32 clinical isolates of multiresistant E. coli (19 extended spectrum beta-lactamase producers and 13 non producers) and their transconjugants were analyzed. A total of 95 relaxases were detected, at least one per isolate, underscoring the high potential of these strains for antibiotic-resistance transmission. MOBP12 and MOBF12 plasmids were the most abundant. Most MOB subfamilies detected were present in both subsets of the collection, indicating a shared mobilome among multiresistant E. coli. The plasmid profile obtained by both methods was compared, which provided useful data upon which decisions related to the implementation of detection methods in the clinic could be based. The phylogenetic depth at which replicon and MOB-typing classify plasmids is different. While replicon-typing aims at plasmid replication regions with non-degenerate primers, MOB-typing classifies plasmids into relaxase subfamilies using degenerate primers. As a result, MOB-typing provides a deeper phylogenetic depth than replicon-typing and new plasmid groups are uncovered. Significantly, MOB typing identified 17 plasmids and an integrative and conjugative element, which were not detected by replicon-typing. Four of these backbones were different from previously reported elements. Copyright © 2014 Elsevier Inc. All rights reserved.

An Epichloë festucae homologue of MOB3, a component of the STRIPAK complex, is required for the establishment of a mutualistic symbiotic interaction with Lolium perenne

PubMed Central

Green, Kimberly A.; Becker, Yvonne; Fitzsimons, Helen L.

2016-01-01

Summary In both Sordaria macrospora and Neurospora crassa, components of the conserved STRIPAK (striatin‐interacting phosphatase and kinase) complex regulate cell–cell fusion, hyphal network development and fruiting body formation. Interestingly, a number of Epichloë festucae genes that are required for hyphal cell–cell fusion, such as noxA, noxR, proA, mpkA and mkkA, are also required for the establishment of a mutualistic symbiotic interaction with Lolium perenne. To determine whether MobC, a homologue of the STRIPAK complex component MOB3 in S. macrospora and N. crassa, is required for E. festucae hyphal fusion and symbiosis, a mobC deletion strain was generated. The ΔmobC mutant showed reduced rates of hyphal cell–cell fusion, formed intrahyphal hyphae and exhibited enhanced conidiation. Plants infected with ΔmobC were severely stunted. Hyphae of ΔmobC showed a proliferative pattern of growth within the leaves of Lolium perenne with increased colonization of the intercellular spaces and vascular bundles. Although hyphae were still able to form expressoria, structures allowing the colonization of the leaf surface, the frequency of formation was significantly reduced. Collectively, these results show that the STRIPAK component MobC is required for the establishment of a mutualistic symbiotic association between E. festucae and L. perenne, and plays an accessory role in the regulation of hyphal cell–cell fusion and expressorium development in E. festucae. PMID:27277141

Comparison of odor and mating-induced glomerular activation in the main olfactory bulb of estrous female ferrets.

PubMed

Batterton, M N; Robarts, D; Woodley, S K; Baum, M J

2006-06-12

Previously [S.K. Woodley, M.J. Baum, Differential activation of glomeruli in the ferret's main olfactory bulb by anal scent gland odors from males and females: an early step in mate identification, Eur. J. Neurosci. 20 (2004) 1025-1032], the receipt of intromission from a male activated glomeruli (indexed by Fos immunoreactivity in juxtaglomerular cells) in the main olfactory bulb (MOB) of estrous female ferrets which exceeded the activation seen after exposure to male anal scent gland odorants alone. We asked whether centrifugal inputs (e.g., from the locus coeruleus to the MOB) generated by the receipt of vaginal-cervical stimulation influence odor-induced MOB glomerular activation. We compared the activation of MOB glomeruli in estrous female ferrets which received a unilateral naris occlusion prior to exposure to: unscented air, volatile odorants from an anesthetized male, volatile + non-volatile odorants from direct physical contact with an anesthetized male, or mating stimulation. Little glomerular activation was observed in the MOB ipsilateral to an occluded naris, including females which received intromission. An equivalent distribution of activated glomeruli was observed in the ventral MOB of estrous females which either received mating stimulation or had direct physical contact with an anesthetized male. Considerably less glomerular activation occurred in females exposed only to volatile male odors. The MOB of female ferrets responded to body odorants from the opposite sex; however, there was no evidence that mating-induced centrifugal inputs directly activated MOB glomeruli or modified odor-induced glomerular activation.

Comparing optical test methods for a lightweight primary mirror of a space-borne Cassegrain telescope

NASA Astrophysics Data System (ADS)

Lin, Wei-Cheng; Chang, Shenq-Tsong; Yu, Zong-Ru; Lin, Yu-Chuan; Ho, Cheng-Fong; Huang, Ting-Ming; Chen, Cheng-Huan

2014-09-01

A Cassegrain telescope with a 450 mm clear aperture was developed for use in a spaceborne optical remote-sensing instrument. Self-weight deformation and thermal distortion were considered: to this end, Zerodur was used to manufacture the primary mirror. The lightweight scheme adopted a hexagonal cell structure yielding a lightweight ratio of 50%. In general, optical testing on a lightweight mirror is a critical technique during both the manufacturing and assembly processes. To prevent unexpected measurement errors that cause erroneous judgment, this paper proposes a novel and reliable analytical method for optical testing, called the bench test. The proposed algorithm was used to distinguish the manufacturing form error from surface deformation caused by the mounting, supporter and gravity effects for the optical testing. The performance of the proposed bench test was compared with a conventional vertical setup for optical testing during the manufacturing process of the lightweight mirror.

Preliminary investigation of air bubbling and dietary sulfur reduction to mitigate hydrogen sulfide and odor from swine waste.

PubMed

Clark, O Grant; Morin, Brent; Zhang, Yongcheng; Sauer, Willem C; Feddes, John J R

2005-01-01

When livestock manure slurry is agitated, the sudden release of hydrogen sulfide (H(2)S) can raise concentrations to dangerous levels. Low-level air bubbling and dietary S reduction were evaluated as methods for reducing peak H(2)S emissions from swine (Sus scrofa) manure slurry samples. In a first experiment, 15-L slurry samples were stored in bench-scale digesters and continuously bubbled with air at 0 (control), 5, or 10 mL min(-1) for 28 d. The 5-L headspace of each digester was also continuously ventilated at 40 mL min(-1) and the mean H(2)S concentration in the outlet air was <10 microL L(-1). On Day 28, the slurry was agitated suddenly. The peak H(2)S concentration exceeded instrument range (>120 microL L(-1)) from the control treatment, and was 47 and 3.4 microL L(-1) for the 5 and 10 mL min(-1) treatments, respectively. In a second experiment, individually penned barrows were fed rations with dietary S concentrations of 0.34, 0.24, and 0.15% (w/w). Slurry derived from each diet was bubbled with air in bench-scale digesters, as before, at 10 mL min(-1) for 12 d and the mean H(2)S concentration in the digester outlet air was 11 microL L(-1). On Day 12, the slurry was agitated but the H(2)S emissions did not change significantly. Both low-level bubbling of air through slurry and dietary S reduction appear to be viable methods for reducing peak H(2)S emissions from swine manure slurry at a bench scale, but these approaches must be validated at larger scales.

Development of a pyramidal wavefront sensor test-bench at INO

NASA Astrophysics Data System (ADS)

Turbide, Simon; Wang, Min; Gauvin, Jonny; Martin, Olivier; Savard, Maxime; Bourqui, Pascal; Veran, Jean-Pierre; Deschenes, William; Anctil, Genevieve; Chateauneuf, François

2013-12-01

The key technical element of the adaptive optics in astronomy is the wavefront sensing (WFS). One of the advantages of the pyramid wavefront sensor (P-WFS) over the widely used Shack-Hartmann wavefront sensor seems to be the increased sensitivity in closed-loop applications. A high-sensitivity and large dynamic-range WFS, such as P-WFS technology, still needs to be further investigated for proper justification in future Extremely Large Telescopes application. At INO, we have recently carried out the optical design, testing and performance evaluation of a P-WFS bench setup. The optical design of the bench setup mainly consists of the super-LED fiber source, source collimator, spatial light modulator (SLM), relay lenses, tip-tilt mirror, Fourier-transforming lens, and a four-faceted glass pyramid with a large vertex angle as well as pupil re-imaged optics. The phase-only SLM has been introduced in the bench setup to generate atmospheric turbulence with a maximum phase shift of more than 2π at each pixel (256 grey levels). Like a modified Foucault knife-edge test, the refractive pyramid element is used to produce four images of the entrance pupil on a CCD camera. The Fourier-transforming lens, which is used before the pyramid prism, is designed for telecentric output to allow dynamic modulation (rotation of the beam around the pyramid-prism center) from a tip-tilt mirror. Furthermore, a P-WFS diffraction-based model has been developed. This model includes most of the system limitations such as the SLM discrete voltage steps and the CCD pixel pitch. The pyramid effects (edges and tip) are considered as well. The modal wavefront reconstruction algorithm relies on the construction of an interaction matrix (one for each modulation's amplitude). Each column of the interaction matrix represents the combination of the four pupil images for a given wavefront aberration. The nice agreement between the data and the model suggest that the limitation of the system is not the P-WFS itself, but rather its environment such as source intensity fluctuation and vibration of the optical bench. Finally, the phase-reconstruction errors of the P-WFS have been compared to those of a Shack-Hartmann, showing the regions of interest of the former system. The bench setup will be focusing on the astronomy application as well as commercial applications, such as bio-medical application etc.

Mobbing and Stress

ERIC Educational Resources Information Center

Yaman, Erkan

2015-01-01

Mobbing is an important construct which has impact on the numerous psychological variables. The purpose of this study is to examine the relationships between mobbing and stress. Participants were 436 teachers (206 (55%) were female, 230 (45%) were male) from Sakarya, Turkey. Their ages ranged from 26 to 55 years and the mean age of the…

Workplace Mobbing: A Discussion for Librarians

ERIC Educational Resources Information Center

Hecker, Thomas E.

2007-01-01

Workplace mobbing occurs in libraries but is usually unrecognized and unchecked because the phenomenon has not been described and given a name. This discussion provides the library profession with an overview but also with specific background details to assist with recognizing mobbing and preventing severe harm to employees and organizations.

Treatment of Mobbing in School: Principles for and the Results of the Work of an Anti Mobbing Group

ERIC Educational Resources Information Center

Pikas, Anatol

1975-01-01

Article attempted to define the concept of mobbing and to develop principles of treatment in connection with cases which really occur, and to use the work in a regular university course providing students with successful personal therapeutic experiences. (Author/RK)

Mobbing, Organizational Identification, and Perceived Support: Evidence from a Higher Education Institution

ERIC Educational Resources Information Center

Coskuner, Selda; Costur, Recai; Bayhan-Karapinar, Pinar; Metin-Camgoz, Selin; Ceylan, Savas; Demirtas-Zorbaz, Selen; Aktas, Emine Feyza; Ciffiliz, Gonca

2018-01-01

Purpose: The aim of the current study is twofold. First, it investigates the relationship between mobbing and organizational identification (OI) as an organizational attitude. Second, it explores the moderating effect of perceived organizational support (POS) on the relationship between mobbing and organizational identification. We proposed that…

SedMob: A mobile application for creating sedimentary logs in the field

NASA Astrophysics Data System (ADS)

Wolniewicz, Pawel

2014-05-01

SedMob is an open-source, mobile software package for creating sedimentary logs, targeted for use in tablets and smartphones. The user can create an unlimited number of logs, save data from each bed in the log as well as export and synchronize the data with a remote server. SedMob is designed as a mobile interface to SedLog: a free multiplatform package for drawing graphic logs that runs on PC computers. Data entered into SedMob are saved in the CSV file format, fully compatible with SedLog.

Serum levels of carbonylated and nitrosylated proteins in mobbing victims with workplace adjustment disorders.

PubMed

Di Rosa, A E; Gangemi, S; Cristani, M; Fenga, C; Saitta, S; Abenavoli, E; Imbesi, S; Speciale, A; Minciullo, P L; Spatari, G; Abbate, S; Saija, A; Cimino, F

2009-12-01

Today the most important problem in the work place is psychological abuse, which may affect the health because of high levels of stress and anxiety. There is evidence that most psychiatric disorders are associated with increased oxidative stress but nothing is reported about the presence of oxidative stress in mobbing victims. This study has been carried out in a group of 19 patients affected by workplace mobbing-due adjustment disorders, in comparison with 38 healthy subjects, to evaluate whether oxidative stress may be induced by mobbing. Serum levels of protein carbonyl groups and of nitrosylated proteins, biological markers of oxidative stress conditions, were higher than those measured in healthy subjects. These findings may contribute to a better understanding of the redox homeostasis dysregulation occurring in victims of workplace mobbing.

Mobbing calls signal predator category in a kin group-living bird species

PubMed Central

Griesser, Michael

2009-01-01

Many prey species gather together to approach and harass their predators despite the associated risks. While mobbing, prey usually utter calls and previous experiments have demonstrated that mobbing calls can convey information about risk to conspecifics. However, the risk posed by predators also differs between predator categories. The ability to communicate predator category would be adaptive because it would allow other mobbers to adjust their risk taking. I tested this idea in Siberian jays Perisoreus infaustus, a group-living bird species, by exposing jay groups to mounts of three hawk and three owl species of varying risks. Groups immediately approached to mob the mount and uttered up to 14 different call types. Jays gave more calls when mobbing a more dangerous predator and when in the presence of kin. Five call types were predator-category-specific and jays uttered two hawk-specific and three owl-specific call types. Thus, this is one of the first studies to demonstrate that mobbing calls can simultaneously encode information about both predator category and the risk posed by a predator. Since antipredator calls of Siberian jays are known to specifically aim at reducing the risk to relatives, kin-based sociality could be an important factor in facilitating the evolution of predator-category-specific mobbing calls. PMID:19474047

Mobbing calls signal predator category in a kin group-living bird species.

PubMed

Griesser, Michael

2009-08-22

Many prey species gather together to approach and harass their predators despite the associated risks. While mobbing, prey usually utter calls and previous experiments have demonstrated that mobbing calls can convey information about risk to conspecifics. However, the risk posed by predators also differs between predator categories. The ability to communicate predator category would be adaptive because it would allow other mobbers to adjust their risk taking. I tested this idea in Siberian jays Perisoreus infaustus, a group-living bird species, by exposing jay groups to mounts of three hawk and three owl species of varying risks. Groups immediately approached to mob the mount and uttered up to 14 different call types. Jays gave more calls when mobbing a more dangerous predator and when in the presence of kin. Five call types were predator-category-specific and jays uttered two hawk-specific and three owl-specific call types. Thus, this is one of the first studies to demonstrate that mobbing calls can simultaneously encode information about both predator category and the risk posed by a predator. Since antipredator calls of Siberian jays are known to specifically aim at reducing the risk to relatives, kin-based sociality could be an important factor in facilitating the evolution of predator-category-specific mobbing calls.

The phocein homologue SmMOB3 is essential for vegetative cell fusion and sexual development in the filamentous ascomycete Sordaria macrospora.

PubMed

Bernhards, Yasmine; Pöggeler, Stefanie

2011-04-01

Members of the striatin family and their highly conserved interacting protein phocein/Mob3 are key components in the regulation of cell differentiation in multicellular eukaryotes. The striatin homologue PRO11 of the filamentous ascomycete Sordaria macrospora has a crucial role in fruiting body development. Here, we functionally characterized the phocein/Mob3 orthologue SmMOB3 of S. macrospora. We isolated the gene and showed that both, pro11 and Smmob3 are expressed during early and late developmental stages. Deletion of Smmob3 resulted in a sexually sterile strain, similar to the previously characterized pro11 mutant. Fusion assays revealed that ∆Smmob3 was unable to undergo self-fusion and fusion with the pro11 strain. The essential function of the SmMOB3 N-terminus containing the conserved mob domain was demonstrated by complementation analysis of the sterile S. macrospora ∆Smmob3 strain. Downregulation of either pro11 in ∆Smmob3, or Smmob3 in pro11 mutants by means of RNA interference (RNAi) resulted in synthetic sexual defects, demonstrating for the first time the importance of a putative PRO11/SmMOB3 complex in fruiting body development.

Risk of psychiatric and neurological diseases in patients with workplace mobbing experience in Germany: a retrospective database analysis.

PubMed

Kostev, Karel; Rex, Juliana; Waehlert, Lilia; Hog, Daniela; Heilmaier, Christina

2014-01-01

The number of mobbing experiences recorded has increased during recent years and it has now been established as global phenomenon among the working population. The goal of our study was to analyze the incidence of certain neurologic and psychiatric diseases as a consequence of mobbing as compared with a control group and to examine the possible influence of previous diseases that occurred within one year before the first mobbing documentation on the incidence of mobbing. We used a large database (IMS® Disease Analyzer, Germany) to collect data from general practitioners in Germany from 01/2003 until 12/2012. Based on age, gender, and health insurance, patients with experience of mobbing were matched with a control group of patients who had not reported workplace mobbing and who were being treated by the same physicians. At first, diseases that occurred within one year before the bullying experience took place ("index date") were noted and compared to a control group of similar composition in terms of gender, age, and health insurance. Subsequently, the prevalence of depression, anxiety, somatoform disorders, and sleep disorders following experiences of mobbing were determined. After adjustment to take into account the odds of bullying, the ratios of these diseases were assessed using a logistic regression model. The study population consisted of n=2,625 patients and n=2,625 controls, of which 33% were men. The number of cases of bullying documented rose continuously from 2003 to 2011 and remained high in 2012. Those who would later become victims of mobbing demonstrated a considerably higher prevalence of diseases in general - these diseases were not confined to the neurologic-psychiatric spectrum. Following experiences of bullying, depression, anxiety, somatoform disorders, and sleep disorders were significantly more prevalent than in the control group (for all, p<0.05). Similarly, odds ratios (OR) representing the risk of suffering from diseases were higher in affected patients, with the highest value (4.28) for depression and the lowest value for sleep disorders (OR=2.4). Those who will later become the victims of bullying are more prone to suffer from diseases in general, even before this experience of mobbing has occurred, which underlines the importance of supporting (chronically) ill patients to protect them against bullying. Sequelae of mobbing include, in particular, diseases from the neurologic-psychiatric spectrum.

Developing microRNA therapeutics.

PubMed

van Rooij, Eva; Purcell, Angela L; Levin, Arthur A

2012-02-03

Rarely a new research area has gotten such an overwhelming amount of attention as have microRNAs. Although several basic questions regarding their biological principles still remain to be answered, many specific characteristics of microRNAs in combination with compelling therapeutic efficacy data and a clear involvement in human disease have triggered the biotechnology community to start exploring the possibilities of viewing microRNAs as therapeutic entities. This review serves to provide some general insight into some of the current microRNAs targets, how one goes from the initial bench discovery to actually developing a therapeutically useful modality, and will briefly summarize the current patent landscape and the companies that have started to explore microRNAs as the next drug target.

Burbank works on the CIR in the U.S. Laboratory

NASA Image and Video Library

2012-04-10

ISS030-E-234735 (10 April 2012) --- NASA astronaut Dan Burbank, Expedition 30 commander, works on the Combustion Integrated Rack (CIR) in the Destiny laboratory of the International Space Station. Burbank disconnected the Moderate Temperature Loop (MTL), Vacuum Exhaust System (VES) and station nitrogen lines of the Optics Bench, translated and rotated it out of the way and replaced a Fluids and Combustion Facility / Diagnostic Control Module (FCF DCM) on its back. Afterwards, Burbank returned the Optics Bench to its nominal position and reconnected the MTL, VES and station nitrogen lines.

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus.

PubMed

Królikowska, Natalia; Szymkowiak, Jakub; Laidlaw, Rebecca Anne; Kuczyński, Lechosław

2016-01-01

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing-observation, approach and usually harassment of a predator-being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing ( Vanellus vanellus ). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax , hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo , white stork Ciconia ciconia , black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory.

Clever strategists: Australian Magpies vary mobbing strategies, not intensity, relative to different species of predator

PubMed Central

Koboroff, A; Kaplan, G

2013-01-01

Anti-predator behaviour of magpies was investigated, using five species of model predators, at times of raising offspring. We predicted differences in mobbing strategies for each predator presented and also that raising juveniles would affect intensity of the mobbing event. Fourteen permanent resident family groups were tested using 5 different types of predator (avian and reptilian) known to be of varying degrees of risk to magpies and common in their habitat. In all, 210 trials were conducted (across three different stages of juvenile development). We found that the stage of juvenile development did not alter mobbing behaviour significantly, but predator type did. Aerial strategies (such as swooping) were elicited by taxidermic models of raptors, whereas a taxidermic model of a monitor lizard was approached on the ground and a model snake was rarely approached. Swooping patterns also changed according to which of the three raptors was presented. Our results show that, in contrast to findings in other species, magpies vary mobbing strategy depending on the predator rather than varying mobbing intensity. PMID:23638394

Clever strategists: Australian Magpies vary mobbing strategies, not intensity, relative to different species of predator.

PubMed

Koboroff, A; Kaplan, G; Rogers, Lj

2013-01-01

Anti-predator behaviour of magpies was investigated, using five species of model predators, at times of raising offspring. We predicted differences in mobbing strategies for each predator presented and also that raising juveniles would affect intensity of the mobbing event. Fourteen permanent resident family groups were tested using 5 different types of predator (avian and reptilian) known to be of varying degrees of risk to magpies and common in their habitat. In all, 210 trials were conducted (across three different stages of juvenile development). We found that the stage of juvenile development did not alter mobbing behaviour significantly, but predator type did. Aerial strategies (such as swooping) were elicited by taxidermic models of raptors, whereas a taxidermic model of a monitor lizard was approached on the ground and a model snake was rarely approached. Swooping patterns also changed according to which of the three raptors was presented. Our results show that, in contrast to findings in other species, magpies vary mobbing strategy depending on the predator rather than varying mobbing intensity.

Remarkable recovery and colonization behaviour of methane oxidizing bacteria in soil after disturbance is controlled by methane source only.

PubMed

Pan, Yao; Abell, Guy C J; Bodelier, Paul L E; Meima-Franke, Marion; Sessitsch, Angela; Bodrossy, Levente

2014-08-01

Little is understood about the relationship between microbial assemblage history, the composition and function of specific functional guilds and the ecosystem functions they provide. To learn more about this relationship we used methane oxidizing bacteria (MOB) as model organisms and performed soil microcosm experiments comprised of identical soil substrates, hosting distinct overall microbial diversities(i.e., full, reduced and zero total microbial and MOB diversities). After inoculation with undisturbed soil, the recovery of MOB activity, MOB diversity and total bacterial diversity were followed over 3 months by methane oxidation potential measurements and analyses targeting pmoA and 16S rRNA genes. Measurement of methane oxidation potential demonstrated different recovery rates across the different treatments. Despite different starting microbial diversities, the recovery and succession of the MOB communities followed a similar pattern across the different treatment microcosms. In this study we found that edaphic parameters were the dominant factor shaping microbial communities over time and that the starting microbial community played only a minor role in shaping MOB microbial community.

The Possible Crosstalk of MOB2 With NDR1/2 Kinases in Cell Cycle and DNA Damage Signaling.

PubMed

Gundogdu, Ramazan; Hergovich, Alexander

2016-09-06

This article is the authors' opinion of the roles of the signal transducer Mps one binder 2 (MOB2) in the control of cell cycle progression and the DNA Damage Response (DDR). We recently found that endogenous MOB2 is required to prevent the accumulation of endogenous DNA damage in order to prevent the undesired, and possibly detrimental, activation of cell cycle checkpoints. In this regard, it is noteworthy that MOB2 has been linked biochemically to the regulation of the NDR1/2 (aka STK38/STK38L) protein kinases, which themselves have functions at different steps of the cell cycle. Therefore, we are speculating in this article about the possible connections of MOB2 with NDR1/2 kinases in cell cycle and DDR Signaling.

Neural Correlates of Threat Perception: Neural Equivalence of Conspecific and Heterospecific Mobbing Calls Is Learned

PubMed Central

Avey, Marc T.; Hoeschele, Marisa; Moscicki, Michele K.; Bloomfield, Laurie L.; Sturdy, Christopher B.

2011-01-01

Songbird auditory areas (i.e., CMM and NCM) are preferentially activated to playback of conspecific vocalizations relative to heterospecific and arbitrary noise [1]–[2]. Here, we asked if the neural response to auditory stimulation is not simply preferential for conspecific vocalizations but also for the information conveyed by the vocalization. Black-capped chickadees use their chick-a-dee mobbing call to recruit conspecifics and other avian species to mob perched predators [3]. Mobbing calls produced in response to smaller, higher-threat predators contain more “D” notes compared to those produced in response to larger, lower-threat predators and thus convey the degree of threat of predators [4]. We specifically asked whether the neural response varies with the degree of threat conveyed by the mobbing calls of chickadees and whether the neural response is the same for actual predator calls that correspond to the degree of threat of the chickadee mobbing calls. Our results demonstrate that, as degree of threat increases in conspecific chickadee mobbing calls, there is a corresponding increase in immediate early gene (IEG) expression in telencephalic auditory areas. We also demonstrate that as the degree of threat increases for the heterospecific predator, there is a corresponding increase in IEG expression in the auditory areas. Furthermore, there was no significant difference in the amount IEG expression between conspecific mobbing calls or heterospecific predator calls that were the same degree of threat. In a second experiment, using hand-reared chickadees without predator experience, we found more IEG expression in response to mobbing calls than corresponding predator calls, indicating that degree of threat is learned. Our results demonstrate that degree of threat corresponds to neural activity in the auditory areas and that threat can be conveyed by different species signals and that these signals must be learned. PMID:21909363

Functional traits determine heterospecific use of risk-related social information in forest birds of tropical South-East Asia.

PubMed

Hua, Fangyuan; Yong, Ding Li; Janra, Muhammad Nazri; Fitri, Liza M; Prawiradilaga, Dewi; Sieving, Kathryn E

2016-12-01

In birds and mammals, mobbing calls constitute an important form of social information that can attract numerous sympatric species to localized mobbing aggregations. While such a response is thought to reduce the future predation risk for responding species, there is surprisingly little empirical evidence to support this hypothesis. One way to test the link between predation risk reduction and mobbing attraction involves testing the relationship between species' attraction to mobbing calls and the functional traits that define their vulnerability to predation risk. Two important traits known to influence prey vulnerability include relative prey-to-predator body size ratio and the overlap in space use between predator and prey; in combination, these measures strongly influence prey accessibility, and therefore their vulnerability, to predators. Here, we combine community surveys with behavioral experiments of a diverse bird assemblage in the lowland rainforest of Sumatra to test whether the functional traits of body mass (representing body size) and foraging height (representing space use) can predict species' attraction to heterospecific mobbing calls. At four forest sites along a gradient of forest degradation, we characterized the resident bird communities using point count and mist-netting surveys, and determined the species groups attracted to standardized playbacks of mobbing calls produced by five resident bird species of roughly similar body size and foraging height. We found that (1) a large, diverse subcommunity of bird species was attracted to the mobbing calls and (2) responding species (especially the most vigorous respondents) tended to be (a) small (b) mid-storey foragers (c) with similar trait values as the species producing the mobbing calls. Our findings from the relatively lesser known bird assemblages of tropical Asia add to the growing evidence for the ubiquity of heterospecific information networks in animal communities, and provide empirical support for the long-standing hypothesis that predation risk reduction is a major benefit of mobbing information networks.

Saccharomyces cerevisiae Mob1p Is Required for Cytokinesis and Mitotic Exit

PubMed Central

Luca, Francis C.; Mody, Manali; Kurischko, Cornelia; Roof, David M.; Giddings, Thomas H.; Winey, Mark

2001-01-01

The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved set of genes that mediate the transition from mitosis to G1 by regulating mitotic cyclin degradation and the inactivation of cyclin-dependent kinase (CDK). Here, we demonstrate that, in addition to mitotic exit, S. cerevisiae MEN gene MOB1 is required for cytokinesis and cell separation. The cytokinesis defect was evident in mob1 mutants under conditions in which there was no mitotic-exit defect. Observation of live cells showed that yeast myosin II, Myo1p, was present in the contractile ring at the bud neck but that the ring failed to contract and disassemble. The cytokinesis defect persisted for several mitotic cycles, resulting in chains of cells with correctly segregated nuclei but with uncontracted actomyosin rings. The cytokinesis proteins Cdc3p (a septin), actin, and Iqg1p/ Cyk1p (an IQGAP-like protein) appeared to correctly localize in mob1 mutants, suggesting that MOB1 functions subsequent to actomyosin ring assembly. We also examined the subcellular distribution of Mob1p during the cell cycle and found that Mob1p first localized to the spindle pole bodies during mid-anaphase and then localized to a ring at the bud neck just before and during cytokinesis. Localization of Mob1p to the bud neck required CDC3, MEN genes CDC5, CDC14, CDC15, and DBF2, and spindle pole body gene NUD1 but was independent of MYO1. The localization of Mob1p to both spindle poles was abolished in cdc15 and nud1 mutants and was perturbed in cdc5 and cdc14 mutants. These results suggest that the MEN functions during the mitosis-to-G1 transition to control cyclin-CDK inactivation and cytokinesis. PMID:11564880

Sporophytic and gametophytic functions of the cell cycle-associated Mob1 gene in Arabidopsis thaliana L.

PubMed

Galla, Giulio; Zenoni, Sara; Marconi, Gianpiero; Marino, Giada; Botton, Alessandro; Pinosa, Francesco; Citterio, Sandra; Ruperti, Benedetto; Palme, Klaus; Albertini, Emidio; Pezzotti, Mario; Mau, Martin; Sharbel, Timothy F; De Storme, Nico; Geelen, Danny; Barcaccia, Gianni

2011-09-15

Mob1 genes are primarily involved in the cell cycle progression and mitosis exit in yeasts and animals. The function of a Mob1-like gene (At5g45550) from Arabidopsis thaliana was investigated using RNAi and immunological staining. AtMob1-like RNAi silenced lines showed a reduced radial expansion of the inflorescence stem and a reduced elongation zone of the primary root. Morphological features of plant organs were accompanied by a reduction in cell size. The fertility of AtMob1-like RNAi silenced lines was very low as seed production was strongly reduced. About 2% of the progeny of AtMob1-like RNAi silenced plants were tetraploid. The female and male sporogenesis was affected differentially. The ovules developed irregularly and one third of the megaspores and embryo sacs degenerated prematurely. Up to 20% of the ovules produced binucleated megaspores that failed to develop further, being their degeneration likely accompanied with a delayed programmed cell death. The anthers produced about 30% of aborted pollen grains, showing also a strong variation in their size. Together, the results show that Arabidopsis MOB1-like is required to regulate cell expansion and cell division, presumably by affecting the mitotic as well as the meiotic cell cycle. Copyright © 2011 Elsevier B.V. All rights reserved.

[Workplace mobbing].

PubMed

Soljan, Ivana; Josipović-Jelić, Zeljka; Jelić Kis, I Anita

2008-03-01

Workplace mobbing is a hostile and unethical communication, systematically aimed from one or more individuals towards mostly one individual, who are forced into a helpless position and are held in it by constant bullying. This article describes some of the most important characteristics of mobbing: offensive behaviour, organizational and non-organizational causes of this behaviour, the victim and the consequences. Modern business environment is complex, dynamic, volatile, and requires better ability to adjust. Constant changes are a part of organizational reality, but they also produce an ideal environment for all kinds of conflicts. Conflicts are inevitable in every organization, but the task of its management is to identify them and resolve before they affect the workforce, productivity and costs. The idea is to avert psychological abuse and aberrant behaviour such as mobbing which that may cause physical and mental disorders. Mobbing is a problem of the modern society; as a violation of human rights it is relatively new and unrecognised in Croatia. Abuse is mostly psychological: it affects the victim's health and life, quality of work, productivity, profitability, and may lead to significant economic losses in the community. Mobbing can be averted by joint forces that would involve employee and management, medical and legal professionals, and even community as a whole. The more an organization pursues excellence based on trust and business ethics, the higher the probability that mobbing will be averted or stopped.

Perception of Mobbing by Teachers and Organizational Depression: A Correlational Model Study

ERIC Educational Resources Information Center

Toytok, Esef Hakan

2017-01-01

As is known, mobbing (intimidation) is an important concept being subject to many researches in numerous fields and many researchers suggest that this concept has the power to directly affect organizational structures. Even though the concept of mobbing changes from country to country, culture to culture and organization to organization, it is…

Au Contraire: Gifted in a Flash (Mob)

ERIC Educational Resources Information Center

Delisle, James R.

2012-01-01

A "flash mob" is defined by Wikipedia as "a large group of people who assemble suddenly in a public place, perform an unusual and pointless act for a brief time, then disperse." Fueled by social media and Smartphones, flash mobs have been used, primarily, as entertaining diversions by addicted techies with (apparently) tons of time on their hands.…

An Economic Model of Workplace Mobbing in Academe

ERIC Educational Resources Information Center

Faria, Joao Ricardo; Mixon, Franklin G., Jr.; Salter, Sean P.

2012-01-01

Workplace bullying or mobbing can be defined as the infliction of various forms of abuse (e.g., verbal, emotional, psychological) against a colleague or subordinate by one or more other members of a workplace. Even in the presence of academic tenure, workplace mobbing remains a prevalent issue in academe. This study develops an economic model that…

Bullying and Mobbing in Academe: Challenges for Distance Education and Social Media Applications

ERIC Educational Resources Information Center

Oravec, Jo Ann

2012-01-01

Bullying and mobbing are migrating to online realms, intensifying the damage involved and increasing the complexities of these issues. Social media (such as Facebook and Twitter) are intensely communal in many senses; they may serve to increase the negative aspects of bullying and mobbing as well as provide community-oriented tools for mitigation.…

Perception of Faculty Members Exposed to Mobbing about the Organizational Culture and Climate

ERIC Educational Resources Information Center

Yaman, Erkan

2010-01-01

The present research aimed to investigate non-ethical behaviors and mobbing to which academic staff in universities are subjected. Twelve academic staff who were subjected to mobbing in universities in Turkey were interviewed. The research was formed in a qualitative design. Results show that the metaphors that the instructors use to liken their…

Design guidelines for high dimensional stability of CFRP optical bench

NASA Astrophysics Data System (ADS)

Desnoyers, Nichola; Boucher, Marc-André; Goyette, Philippe

2013-09-01

In carbon fiber reinforced plastic (CFRP) optomechanical structures, particularly when embodying reflective optics, angular stability is critical. Angular stability or warping stability is greatly affected by moisture absorption and thermal gradients. Unfortunately, it is impossible to achieve the perfect laminate and there will always be manufacturing errors in trying to reach a quasi-iso laminate. Some errors, such as those related to the angular position of each ply and the facesheet parallelism (for a bench) can be easily monitored in order to control the stability more adequately. This paper presents warping experiments and finite-element analyses (FEA) obtained from typical optomechanical sandwich structures. Experiments were done using a thermal vacuum chamber to cycle the structures from -40°C to 50°C. Moisture desorption tests were also performed for a number of specific configurations. The selected composite material for the study is the unidirectional prepreg from Tencate M55J/TC410. M55J is a high modulus fiber and TC410 is a new-generation cyanate ester designed for dimensionally stable optical benches. In the studied cases, the main contributors were found to be: the ply angular errors, laminate in-plane parallelism (between 0° ply direction of both facesheets), fiber volume fraction tolerance and joints. Final results show that some tested configurations demonstrated good warping stability. FEA and measurements are in good agreement despite the fact that some defects or fabrication errors remain unpredictable. Design guidelines to maximize the warping stability by taking into account the main dimensional stability contributors, the bench geometry and the optical mount interface are then proposed.

Risk of psychiatric and neurological diseases in patients with workplace mobbing experience in Germany: a retrospective database analysis

PubMed Central

Kostev, Karel; Rex, Juliana; Waehlert, Lilia; Hog, Daniela; Heilmaier, Christina

2014-01-01

Introduction: The number of mobbing experiences recorded has increased during recent years and it has now been established as global phenomenon among the working population. The goal of our study was to analyze the incidence of certain neurologic and psychiatric diseases as a consequence of mobbing as compared with a control group and to examine the possible influence of previous diseases that occurred within one year before the first mobbing documentation on the incidence of mobbing. Material & methods: We used a large database (IMS® Disease Analyzer, Germany) to collect data from general practitioners in Germany from 01/2003 until 12/2012. Based on age, gender, and health insurance, patients with experience of mobbing were matched with a control group of patients who had not reported workplace mobbing and who were being treated by the same physicians. At first, diseases that occurred within one year before the bullying experience took place (“index date”) were noted and compared to a control group of similar composition in terms of gender, age, and health insurance. Subsequently, the prevalence of depression, anxiety, somatoform disorders, and sleep disorders following experiences of mobbing were determined. After adjustment to take into account the odds of bullying, the ratios of these diseases were assessed using a logistic regression model. Results: The study population consisted of n=2,625 patients and n=2,625 controls, of which 33% were men. The number of cases of bullying documented rose continuously from 2003 to 2011 and remained high in 2012. Those who would later become victims of mobbing demonstrated a considerably higher prevalence of diseases in general – these diseases were not confined to the neurologic-psychiatric spectrum. Following experiences of bullying, depression, anxiety, somatoform disorders, and sleep disorders were significantly more prevalent than in the control group (for all, p<0.05). Similarly, odds ratios (OR) representing the risk of suffering from diseases were higher in affected patients, with the highest value (4.28) for depression and the lowest value for sleep disorders (OR=2.4). Conclusion: Those who will later become the victims of bullying are more prone to suffer from diseases in general, even before this experience of mobbing has occurred, which underlines the importance of supporting (chronically) ill patients to protect them against bullying. Sequelae of mobbing include, in particular, diseases from the neurologic-psychiatric spectrum. PMID:24872810

Ordering the mob: Insights into replicon and MOB typing schemes from analysis of a curated dataset of publicly available plasmids.

PubMed

Orlek, Alex; Phan, Hang; Sheppard, Anna E; Doumith, Michel; Ellington, Matthew; Peto, Tim; Crook, Derrick; Walker, A Sarah; Woodford, Neil; Anjum, Muna F; Stoesser, Nicole

2017-05-01

Plasmid typing can provide insights into the epidemiology and transmission of plasmid-mediated antibiotic resistance. The principal plasmid typing schemes are replicon typing and MOB typing, which utilize variation in replication loci and relaxase proteins respectively. Previous studies investigating the proportion of plasmids assigned a type by these schemes ('typeability') have yielded conflicting results; moreover, thousands of plasmid sequences have been added to NCBI in recent years, without consistent annotation to indicate which sequences represent complete plasmids. Here, a curated dataset of complete Enterobacteriaceae plasmids from NCBI was compiled, and used to assess the typeability and concordance of in silico replicon and MOB typing schemes. Concordance was assessed at hierarchical replicon type resolutions, from replicon family-level to plasmid multilocus sequence type (pMLST)-level, where available. We found that 85% and 65% of the curated plasmids could be replicon and MOB typed, respectively. Overall, plasmid size and the number of resistance genes were significant independent predictors of replicon and MOB typing success. We found some degree of non-concordance between replicon families and MOB types, which was only partly resolved when partitioning plasmids into finer-resolution groups (replicon and pMLST types). In some cases, non-concordance was attributed to ambiguous boundaries between MOBP and MOBQ types; in other cases, backbone mosaicism was considered a more plausible explanation. β-lactamase resistance genes tended not to show fidelity to a particular plasmid type, though some previously reported associations were supported. Overall, replicon and MOB typing schemes are likely to continue playing an important role in plasmid analysis, but their performance is constrained by the diverse and dynamic nature of plasmid genomes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

PubMed

Krams, Indrikis; Krama, Tatjana

2002-11-22

When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities.

Cases of mobbing activities as commonly seen in the healthcare sector in the world and in Turkey.

PubMed

Ofluoğlu, Gökhan; Somunoğlu, Sinem

2012-01-01

Service process on a site in the health sector does not only bring people and services into contact, but also all other people who share the fate of particular working medium. Although these people should cooperate and care about each other, contributing new merits to humanity with their synergy, meeting of people with the other people from time to time intertwine into a bitter, pain giving relation, like the way it happens with meeting of people with services. Owing to its controversy to humanitarian nature, religious and social values, the pain that human beings cause to one another is occasionally disguised behind a veil, thus turning into a life tragedy for individuals in the background. Mobbing which is commonly a confrontable problem in every workplace means psychological violence, enclosure, harassment, molestation or endurance. This study aims to draw attention to the precautions required to be taken against mobbing activities by analyzing situations of health employees who undergo mobbing actions in Turkey and in the World. To achieve this, the existing studies concerning mobbing in the healthcare sector have been examined. In conclusion; it is determined that mobbing activities towards healthcare workers have limited their communication possibilities, damaged social relations and social image, prevented vocational improvement and destroyed mental health of employees. With respect to mobbing behavior towards health employees, we should adopt a democratic, contributing, and guiding administration style, we should apply organizational justice, excessive work inspections must be reduced, work ethics and social responsibility awareness must be developed, we should clearly determine the duties and responsibilities, physical conditions must be improved and necessary legal arrangements concerning the subject must be made to be able to prevent mobbing.

Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

PubMed Central

Krams, Indrikis; Krama, Tatjana

2002-01-01

When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities. PMID:12495502

The Relationship between Leadership Styles (Autocratic and Democratic) of School Administrators and the Mobbing Teachers Suffer

ERIC Educational Resources Information Center

Peker, Sevinç; Inandi, Yusuf; Giliç, Fahrettin

2018-01-01

The aim of the study is to investigate the relationship between democratic and autocratic leadership styles of school administrators and mobbing teachers experience as well as determining whether these leadership styles predict the mobbing level teachers suffer. The data in the study were collected from 395 primary school teachers (165 male and…

Mentoring as a Way to Change a Culture of Academic Bullying and Mobbing in the Humanities

ERIC Educational Resources Information Center

Metzger, Angela M.; Petit, Angela; Sieber, Sharon

2015-01-01

In 2009, the "Chronicle of Higher Education" defined "academic mobbing" as "a form of bullying in which members of a department gang up to isolate or humiliate a colleague". In their call for a special issue on mobbing for "Workplace: A Journal for Academic Labor", editors Stephen Petrina and E. Wayne Ross…

Avian Mobbing of the Puerto Rican Boa (Epicrates inornatus)

Treesearch

JAVIER E. MERCADO; ESTEBAN TERRANOVA; JR. WUNDERLE

2002-01-01

Mobbing, defined as an intense collective behavior in which birds of one or more species scold or even physically attack a predator, is known from a variety of bird species (Campbell and Lack, 1985; Gill, 1995). Targets commonly include hawks, owls, and snakes. In the West Indies, observations have documented avian mobbing towards various hawk species (e.g., Jeffrey-...

Suicide risk and exposure to mobbing.

PubMed

Pompili, Maurizio; Lester, David; Innamorati, Marco; De Pisa, Eleonora; Iliceto, Paolo; Puccinno, Marianna; Fiori Nastro, Paolo; Tatarelli, Roberto; Girardi, Paolo

2008-01-01

The aim of this study was to study suicide risk in subjects exposed to mobbing, that is, systematic psychological harassment in the workplace. Such psychological harassment, unique to the workplace, threatens both the emotional well-being and professional ability of its victims. The items of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) that assess suicide risk were studied in 102 individuals who were exposed to mobbing. The results indicated that individuals exposed to mobbing had clear differences on the MMPI-2 from normative samples. In addition, those who appeared to be at risk for suicide differed in their scores from those not at risk. Implications for psychopathology and suicide preventions are discussed.

Factors affecting performance and productivity of nurses: professional attitude, organisational justice, organisational culture and mobbing.

PubMed

Terzioglu, Fusun; Temel, Safiye; Uslu Sahan, Fatma

2016-09-01

To identify relationships among variables affecting nurses' performance and productivity, namely professional attitudes, organisational culture, organisational justice and exposure to mobbing. The determination of the factors affecting performance and productivity is important for providing efficient nursing services. These factors have been investigated in the literature independently, but the relationship among them has not been clearly identified. This cross-sectional questionnaire study included 772 nurses working in a University Hospital accredited by Joint Commission International. The professional attitude score of the nurses was high (4.35 ± 0.63). However, their organisational justice (2.22 ± 1.26) and organisational culture (2.47 ± 0.71) scores were low. Nurses were subjected to mobbing at a high level (0.82 ± 0.78). As the organisational justice increased, the organisational culture increased and the mobbing decreased. As the organisation culture decreased, the mobbing increased. There was a positive correlation between organisation culture and organisational justice of the nurses and a negative correlation with mobbing. The results of the study are essential for improving nurses' performance and productivity. © 2016 John Wiley & Sons Ltd.

Assessment of Turkish junior male physicians' exposure to mobbing behavior.

PubMed

Sahin, Bayram; Cetin, Mehmet; Cimen, Mesut; Yildiran, Nuri

2012-08-01

To determine the extent of Turkish junior male physicians' exposure to mobbing behavior and its correlation with physicians' characteristics. The study included physicians recruited for compulsory military service in April 2009. No sampling method was used, questionnaires were delivered to all physicians, and 278 of 292 (95%) questionnaires were returned. We used Leymann Inventory of Psychological Terror including 45 items for data collection and structural equation model for data analysis. A total of 87.7% of physicians experienced mobbing behavior. Physicians who worked more than 40 hours a week, single physicians, physicians working in university hospitals and private hospitals, and physicians who did not have occupational commitment were more exposed to mobbing (P<0.05). Mobbing was not associated with specialty status, service period, age, and personality variables (P>0.05). All goodness-of- fit indices of the model were acceptable (χ(2)=1.449, normed fit index=0.955, Tucker Lewis index=0.980, comparative fit index=0.985, and root mean square error of approximation=0.040). Workplace mobbing is a critical problem for junior male physicians in Turkey. We suggest an introduction of a reporting system and education activities for physicians in high-risk groups.

Hydrophobic Motif Phosphorylation Coordinates Activity and Polar Localization of the Neurospora crassa Nuclear Dbf2-Related Kinase COT1

PubMed Central

Maerz, Sabine; Dettmann, Anne

2012-01-01

Nuclear Dbf2p-related (NDR) kinases and associated proteins are recognized as a conserved network that regulates eukaryotic cell polarity. NDR kinases require association with MOB adaptor proteins and phosphorylation of two conserved residues in the activation segment and hydrophobic motif for activity and function. We demonstrate that the Neurospora crassa NDR kinase COT1 forms inactive dimers via a conserved N-terminal extension, which is also required for the interaction of the kinase with MOB2 to generate heterocomplexes with basal activity. Basal kinase activity also requires autophosphorylation of the COT1-MOB2 complex in the activation segment, while hydrophobic motif phosphorylation of COT1 by the germinal center kinase POD6 fully activates COT1 through induction of a conformational change. Hydrophobic motif phosphorylation is also required for plasma membrane association of the COT1-MOB2 complex. MOB2 further restricts the membrane-associated kinase complex to the hyphal apex to promote polar cell growth. These data support an integrated mechanism of NDR kinase regulation in vivo, in which kinase activation and cellular localization of COT1 are coordinated by dual phosphorylation and interaction with MOB2. PMID:22451488

Testing the pyramid truth wavefront sensor for NFIRAOS in the lab

NASA Astrophysics Data System (ADS)

Mieda, Etsuko; Rosensteiner, Matthias; van Kooten, Maaike; Veran, Jean-Pierre; Lardiere, Olivier; Herriot, Glen

2016-07-01

For today and future adaptive optics observations, sodium laser guide stars (LGSs) are crucial; however, the LGS elongation problem due to the sodium layer has to be compensated, in particular for extremely large telescopes. In this paper, we describe the concept of truth wavefront sensing as a solution and present its design using a pyramid wavefront sensor (PWFS) to improve NFIRAOS (Narrow Field InfraRed Adaptive Optics System), the first light adaptive optics system for Thirty Meter Telescope. We simulate and test the truth wavefront sensor function under a controlled environment using the HeNOS (Herzberg NFIRAOS Optical Simulator) bench, a scaled-down NFIRAOS bench at NRC-Herzberg. We also touch on alternative pyramid component options because despite recent high demands for PWFSs, we suffer from the lack of pyramid supplies due to engineering difficulties.

Manufacturing, integration, and test results of the MATISSE cold optics bench

NASA Astrophysics Data System (ADS)

Bettonvil, Felix C. M.; Kroes, G.; Agoćs, T.; van Duin, A.; Elswijk, E.; de Haan, M.; ter Horst, R.; Kragt, J.; Kuindersma, J.; Navarro, R.; Roelfsema, R.; Schuil, M.; Tromp, T.; Venema, L.; van Kessel, F.; Jaskó, A.

2014-07-01

MATISSE is the second-generation mid-infrared interferometric spectrograph and imager for ESO's Very Large Telescope Interferometer (VLTI). NOVA-ASTRON is responsible for the Cold Optics Bench (COB), representing the last part of the optics train where the four beams are re-arranged, spectrally dispersed and combined. The COB consist of two sister units, one for the LM-band, one for the N-band, which were successively completed at NOVA-ASTRON in autumn 2013 and spring 2014. The LM-band COB is under cryogenic test in its cryostat at MPIA/Heidelberg; the N-band COB finished cryogenic tests and has been installed at OCA/Nice for integration together with the Warm Optics. This paper focuses on the manufacturing, integration and test results of the COBs, and gives an overview of the current status.

4 channels x 10-Gbps optoelectronic transceiver based on silicon optical bench technology

NASA Astrophysics Data System (ADS)

Chen, Chin T.; Hsiao, Hsu L.; Chang, Chia. C.; Shen, Po K.; Lu, Guan F.; Lee, Yun C.; Chang, Shou F.; Lin, Yo S.; Wu, Mount L.

2012-01-01

In this paper, a bi-directional 4-channel x 10-Gbps optoelectronic transceiver based on this silicon optical bench (SiOB) technology is developed. A bi-directional optical sub-assembly (BOSA), fiber ribbon assembly, PCB with high frequency trace design, transmitter driver, and receiver TIA IC are included in this transceiver. The BOSA and PCB also have some specific design for conventional chip-on-board (COB) process. In eye diagram measurement, the transmitter can pass 10-G Ethernet eye mask with 25% margin at room temperature; Bit-error-rate (BER) performance from the transmitter to receiver via 10-meter fiber can achieve 10-12 order, which confirm the transceiver's ability of 10-Gbps data transmission per a channel.

Microgravity

NASA Image and Video Library

2000-01-31

The optical bench for the Fluids Integrated Rack section of the Fluids and Combustion Facility (FCF) is shown extracted for servicing and with the optical bench rotated 90 degrees for access to the rear elements. The FCF will be installed, in phases, in the Destiny, the U.S. Laboratory Module of the International Space Station (ISS), and will accommodate multiple users for a range of investigations. This is an engineering mockup; the flight hardware is subject to change as designs are refined. The FCF is being developed by the Microgravity Science Division (MSD) at the NASA Glenn Research Center. (Photo credit: NASA/Marshall Space Flight Center)

Microgravity

NASA Image and Video Library

2000-01-31

The optical bench for the Fluids Integrated Rack section of the Fluids and Combustion Facility (FCF) is shown extracted for servicing and with the optical bench rotated 90 degrees to access the rear elements. The FCF will be installed, in phases, in the Destiny, the U.S. Laboratory Module of the International Space Station (ISS), and will accommodate multiple users for a range of investigations. This is an engineering mockup; the flight hardware is subject to change as designs are refined. The FCF is being developed by the Microgravity Science Division (MSD) at the NASA Glenn Research Center. (Photo credit: NASA/Marshall Space Flight Center)

International Space Station -- Fluid Physics Rack

NASA Technical Reports Server (NTRS)

2000-01-01

The optical bench for the Fluids Integrated Rack section of the Fluids and Combustion Facility (FCF) is shown extracted for servicing and with the optical bench rotated 90 degrees to access the rear elements. The FCF will be installed, in phases, in the Destiny, the U.S. Laboratory Module of the International Space Station (ISS), and will accommodate multiple users for a range of investigations. This is an engineering mockup; the flight hardware is subject to change as designs are refined. The FCF is being developed by the Microgravity Science Division (MSD) at the NASA Glenn Research Center. (Photo credit: NASA/Marshall Space Flight Center)

Development of a mobbing short scale in the Gutenberg Health Study.

PubMed

Garthus-Niegel, Susan; Nübling, Matthias; Letzel, Stephan; Hegewald, Janice; Wagner, Mandy; Wild, Philipp S; Blettner, Maria; Zwiener, Isabella; Latza, Ute; Jankowiak, Sylvia; Liebers, Falk; Seidler, Andreas

2016-01-01

Despite its highly detrimental potential, most standard questionnaires assessing psychosocial stress at work do not include mobbing as a risk factor. In the German standard version of COPSOQ, mobbing is assessed with a single item. In the Gutenberg Health Study, this version was used together with a newly developed short scale based on the Leymann Inventory of Psychological Terror. The purpose of the present study was to evaluate the psychometric properties of these two measures, to compare them and to test their differential impact on relevant outcome parameters. This analysis is based on a population-based sample of 1441 employees participating in the Gutenberg Health Study. Exploratory and confirmatory factor analyses and reliability analyses were used to assess the mobbing scale. To determine their predictive validities, multiple linear regression analyses with six outcome parameters and log-binomial regression models for two of the outcome aspects were run. Factor analyses of the five-item scale confirmed a one-factor solution, reliability was α = 0.65. Both the single-item and the five-item scales were associated with all six outcome scales. Effect sizes were similar for both mobbing measures. Mobbing is an important risk factor for health-related outcomes. For the purpose of psychosocial risk assessment in the workplace, both the single-item and the five-item constructs were psychometrically appropriate. Associations with outcomes were about equivalent. However, the single item has the advantage of parsimony, whereas the five-item construct depicts several distinct forms of mobbing.

78 FR 18325 - Intent To Prepare an Environmental Impact Statement (EIS) for the Formal Training Unit (FTU) and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... Statement (EIS) for the Formal Training Unit (FTU) and Main Operating Base 1 (MOB 1) for the Beddown of KC... Statement (EIS) for the Formal Training Unit (FTU) and Main Operating Base 1 (MOB 1) for the Beddown of KC...-46A tanker aircraft, associated infrastructure and manpower of the FTU and MOB 1 at existing active...

Examine of Mobbing via Humour Styles of Lecturers at Schools of Physical Education and Sport

ERIC Educational Resources Information Center

Cengiz, Recep; Sunay, Hakan; Yasar, Onur Mutlu

2018-01-01

The aim of the study was to examine the mobbing via humour of the lecturers at Schools of Physical Education and Sport. The sample of the study consisted of 470 lecturers dutied at those schools. In order to analyze the lecturers' perception levels about mobbing via humour behaviours, the "Scale of Humour Behaviours" was used. T-test and…

Aerobic and anaerobic methanotrophic communities in urban landscape wetland.

PubMed

Chen, Sili; Chen, Jianfei; Chang, Sha; Yi, Hao; Huang, Dawei; Xie, Shuguang; Guo, Qingwei

2018-01-01

Both aerobic methane-oxidizing bacteria (MOB) and nitrite-dependent anaerobic methane oxidation (n-damo) organisms can be important methane sinks in a wetland. However, the influences of the vegetation type on aerobic MOB and n-damo communities in wetland, especially in constructed wetland, remain poorly understood. The present study investigated the influences of the vegetation type on both aerobic MOB and n-damo organisms in a constructed urban landscape wetland. Sediments were collected from eight sites vegetated with different plant species. The abundance (1.19-3.27 × 10 7 pmoA gene copies per gram dry sediment), richness (Chao1 estimator = 16.3-81.5), diversity (Shannon index = 2.10-3.15), and structure of the sediment aerobic MOB community were found to vary considerably with sampling site. In contrast, n-damo community abundance (8.74 × 10 5 -4.80 × 10 6 NC10 16S rRNA gene copies per gram dry sediment) changed slightly with the sampling site. The richness (Chao1 estimator = 1-11), diversity (Shannon index = 0-0.78), and structure of the NC10 16S rRNA gene-based n-damo community illustrated slight site-related changes, while the spatial changes of the pmoA gene-based n-damo community richness (Chao1 estimator = 1-8), diversity (Shannon index = 0-0.99), and structure were considerable. The vegetation type could have a profound impact on the wetland aerobic MOB community and had a stronger influence on the pmoA-based n-damo community than on the NC10 16S-based one in urban wetland. Moreover, the aerobic MOB community had greater abundance and higher richness and diversity than the n-damo community. Methylocystis (type II MOB) predominated in urban wetland, while no known type I MOB species was detected. In addition, the ratio of total organic carbon to total nitrogen (C/N) might be a determinant of sediment n-damo community diversity and aerobic MOB richness.

Investigation on the Practicality of Developing Reduced Thermal Models

NASA Technical Reports Server (NTRS)

Lombardi, Giancarlo; Yang, Kan

2015-01-01

Throughout the spacecraft design and development process, detailed instrument thermal models are created to simulate their on-orbit behavior and to ensure that they do not exceed any thermal limits. These detailed models, while generating highly accurate predictions, can sometimes lead to long simulation run times, especially when integrated with a spacecraft observatory model. Therefore, reduced models containing less detail are typically produced in tandem with the detailed models so that results may be more readily available, albeit less accurate. In the current study, both reduced and detailed instrument models are integrated with their associated spacecraft bus models to examine the impact of instrument model reduction on run time and accuracy. Preexisting instrument bus thermal model pairs from several projects were used to determine trends between detailed and reduced thermal models; namely, the Mirror Optical Bench (MOB) on the Gravity and Extreme Magnetism Small Explorer (GEMS) spacecraft, Advanced Topography Laser Altimeter System (ATLAS) on the Ice, Cloud, and Elevation Satellite 2 (ICESat-2), and the Neutral Mass Spectrometer (NMS) on the Lunar Atmosphere and Dust Environment Explorer (LADEE). Hot and cold cases were run for each model to capture the behavior of the models at both thermal extremes. It was found that, though decreasing the number of nodes from a detailed to reduced model brought about a reduction in the run-time, a large time savings was not observed, nor was it a linear relationship between the percentage of nodes reduced and time saved. However, significant losses in accuracy were observed with greater model reduction. It was found that while reduced models are useful in decreasing run time, there exists a threshold of reduction where, once exceeded, the loss in accuracy outweighs the benefit from reduced model runtime.

More than just one Methane Paradox? - Methane Production in Oxic Waters and Aerobic Methane Oxidation under Oxygen-Depleted Conditions

NASA Astrophysics Data System (ADS)

Lehmann, M. F.; Niemann, H.; Bartosiewicz, M.; Blees, J.; Steinle, L.; Su, G.; Zopfi, J.

2016-12-01

The standing paradigm is that methane (CH4) production through methanogenesis occurs exclusively under anoxic conditions and that at least in freshwater environments most of the biogenic CH4 is oxidized by aerobic methanotrophic bacteria (MOB) under oxic conditions. However, subsurface CH4 accumulation in oxic waters, a phenomenon referred to as the "CH4 paradox", has been observed both in the ocean and in lakes, and suggests in-situ CH4 production or a remarkable tolerance of at least some methanogens to O2. Analogously, MOB seem to thrive also under micro-oxic conditions, i.e., they may be responsible for significant CH4 turnover at extremely low O2 concentrations. O2 availability particularly within the sub-micromolar range is likely one of the key factors controlling the balance between CH4 production and consumption in redox-transition zones of aquatic environments, yet threshold O2 concentrations are poorly constrained. Here we provide multiple lines of evidence for apparent "methanogenesis" in well-oxygenated waters and discuss the potential mechanisms that lead to CH4 accumulation in the oxic epilimnia of two south-alpine lakes. On the other end, we present data from a deep meromictic lake, which indicate aerobic CH4 oxidation (MOx) at O2 concentrations below the detection limit of common O2 sensors. A strong MOx potential throughout the anoxic hyplimnion of the studied lake implies that the MOB community is able to survive prolonged periods of O2 starvation and is capable to rapidly resume microaerobic MOx upon introduction of low levels of O2. This conclusion is qualitatively consistent with field data from a coastal shelf environment in the Baltic Sea, where we observed maximum MOx rates during the summer stratification period when O2 concentrations were lowest, implying that in both environments MOx bacteria are adapted to trace levels of O2. Indeed, laboratory experiments at different manipulated O2 concentration levels suggest a nanomolar O2 optimum for MOx in both environments. The very low O2 requirements may reflect the adaption of water column MOB at the organismic level to O2-limited conditions, with several ecological advantages: it allows them to escape grazing pressure and to avoid the detrimental effects of oxidative stress and/or CH4 starvation in more oxygenated waters.

What kind of diagnosis in a case of mobbing: post-traumatic stress disorder or adjustment disorder?

PubMed

Signorelli, Maria Salvina; Costanzo, Maria Cristina; Cinconze, Maria; Concerto, Carmen

2013-06-11

Over the last decade a consistent increase in stress-related psychological consequences at the workplace, usually called 'mobbing', has been seen. It claimed physical, psychical and social distress as its victims, leading to an increased incidence of many illnesses, such as psychosomatic disorders (ache, high blood pressure, chronic fatigue and insomnia) and psychiatric disturbances (high level of anxiety, depression and suicidal attempts). It was recently demonstrated that mobbing is significantly widespread among healthcare workers, especially among female nurses. In this report, we illustrate the case of a nurse who, after a brilliant career, underwent mobbing at the workplace, showing depression, anxiety and sleep disorders that required hospitalisation and a substantial intervention.

[Interpersonal relations as a source of risk of mobbing in the local police].

PubMed

Segurado Torres, Almudena; Agulló Tomás, Esteban; Rodríguez Suárez, Julio; Agulló Tomás, Ma Silveria; Boada i Grau, Joan; Medina Centeno, Raúl

2008-11-01

Social relations in the workplace are one of the main sources of risk for the onset of mobbing. In this work, we analyzed, through the perceived social climate, the influence of interpersonal relations on the characterization of the processes of mobbing, in a sample of local police (N = 235). In particular, the policemen and women's opinions of the quality of the personal relations among the group members and the treatment they receive from the command posts were assessed. The results of the study show that the development of guidelines of social interaction based on discrimination and abuse of authority are predicting variables of mobbing in this group.

System Model for MEMS based Laser Ultrasonic Receiver

NASA Technical Reports Server (NTRS)

Wilson, William C.

2002-01-01

A need has been identified for more advanced nondestructive Evaluation technologies for assuring the integrity of airframe structures, wiring, etc. Laser ultrasonic inspection instruments have been shown to detect flaws in structures. However, these instruments are generally too bulky to be used in the confined spaces that are typical of aerospace vehicles. Microsystems technology is one key to reducing the size of current instruments and enabling increased inspection coverage in areas that were previously inaccessible due to instrument size and weight. This paper investigates the system modeling of a Micro OptoElectroMechanical System (MOEMS) based laser ultrasonic receiver. The system model is constructed in software using MATLAB s dynamical simulator, Simulink. The optical components are modeled using geometrical matrix methods and include some image processing. The system model includes a test bench which simulates input stimuli and models the behavior of the material under test.

Mechanical Description of the Mars Climate Sounder Instrument

NASA Technical Reports Server (NTRS)

Jau, Bruno M.

2008-01-01

This paper introduces the Mars Climate Sounder (MCS) Instrument of the Mars Reconnaissance Orbiter (MRO) spacecraft. The instrument scans the Martian atmosphere almost continuously to systematically acquire weather and climate observations over time. Its primary components are an optical bench that houses dual telescopes with a total of nine channels for visible and infrared sensing, and a two axis gimbal that provides pointing capabilities. Both rotating joints consist of an integrated actuator with a hybrid planetary/harmonic transmission and a twist cap section that enables the electrical wiring to pass through the rotating joint. Micro stepping is used to reduce spacecraft disturbance torques to acceptable levels while driving the stepper motors. To ensure survivability over its four year life span, suitable mechanical components, lubrication, and an active temperature control system were incorporated. Some life test results and lessons learned are provided to serve as design guidelines for actuator parts and flex cables.

Ionizing doses and displacement damage testing of COTS CMOS imagers

NASA Astrophysics Data System (ADS)

Bernard, Frédéric; Petit, Sophie; Courtade, Sophie

2017-11-01

CMOS sensors begin to be a credible alternative to CCD sensors in some space missions. However, technology evolution of CMOS sensors is much faster than CCD one's. So a continuous technology evaluation is needed for CMOS imagers. Many of commercial COTS (Components Off The Shelf) CMOS sensors use organic filters, micro-lenses and non rad-hard technologies. An evaluation of the possibilities offered by such technologies is interesting before any custom development. This can be obtained by testing commercial COTS imagers. This article will present electro-optical performances evolution of off the shelves CMOS imagers after Ionizing Doses until 50kRad(Si) and Displacement Damage environment tests (until 1011 p/cm2 at 50 MeV). Dark current level and non uniformity evolutions are compared and discussed. Relative spectral response measurement and associated evolution with irradiation will also be presented and discussed. Tests have been performed on CNES detection benches.

Linearly chirped fiber Bragg grating response to thermal gradient: from bench tests to the real-time assessment during in vivo laser ablations of biological tissue.

PubMed

Saccomandi, Paola; Varalda, Ambra; Gassino, Riccardo; Tosi, Daniele; Massaroni, Carlo; Caponero, Michele A; Pop, Raoul; Korganbayev, Sanzhar; Perrone, Guido; Diana, Michele; Vallan, Alberto; Costamagna, Guido; Marescaux, Jacques; Schena, Emiliano

2017-09-01

The response of a fiber optic sensor [linearly chirped fiber Bragg grating (LCFBG)] to a linear thermal gradient applied on its sensing length (i.e., 1.5 cm) has been investigated. After these bench tests, we assessed their feasibility for temperature monitoring during thermal tumor treatment. In particular, we performed experiments during ex vivo laser ablation (LA) in pig liver and in vivo thermal ablation in animal models (pigs). We investigated the following: (i) the relationship between the full width at half maximum of the LCFBG spectrum and the temperature difference among the extremities of the LCFBG and (ii) the relationship between the mean spectrum wavelength and the mean temperature acting on the LCFBG sensing area. These relationships showed a linear trend during both bench tests and LA in animal models. Thermal sensitivity was significant although different values were found with regards to bench tests and animal experiments. The linear trend and significant sensitivity allow hypothesizing a future use of this kind of sensor to monitor both temperature gradient and mean temperature within a tissue undergoing thermal treatment. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Sexual Abuse Prevention Mobile Application (SAP_MobAPP) for Primary School Children in Korea.

PubMed

Moon, Kyoung Ja; Park, Kyung Min; Sung, Yunsick

2017-07-01

This study aimed to develop and evaluate the effects of a sexual abuse prevention mobile application, SAP_MobAPP, for primary school children. Forty-five subjects were trained for 40 minutes once a week. The experimental group received education that utilized the SAP_MobAPP. Control group A received Web based sexual abuse prevention education, while control group B received textbook based sexual abuse prevention education. Effectiveness was verified through a survey on child sexual abuse recognition and avoidance skills administered before and after training. The SAP_MobAPP program improved recognition (awareness) and the child's skills to avoid child sexual abuse situations, and the effects were long-lasting. However, differences between groups were not statistically significant. This study developed a sexual abuse prevention application and verified its effectiveness. Awareness and skills to avoid child sexual abuse after app education increased immediately after training and four weeks later. The SAP_MobAPP could be used for sexual abuse prevention education in schools.

Autoethnography and cognitive adaptation: two powerful buffers against the negative consequences of workplace bullying and academic mobbing.

PubMed

Pheko, Mpho M

2018-12-01

Work is undoubtedly fundamental to human life, social development and the economic development of individuals, organizations and nations. However, the experience of working is not always pleasant as there are many instances where relationships between workers could deteriorate, leading to practices and behaviours that could be characterized as workplace bullying and/or mobbing. The current study is an exploratory study which used autoethnography to investigate experiences of academic bullying and mobbing, and relates the practices to power structures in academic institutions. Specifically, the author shares personal experiences and explores the physical and emotional pain of being bullied and mobbed. The author also outlines how both autoethnography and meaning in life strategies were used to cope with the physical and emotional distresses associated with the negative experiences. By outlining the success of the meaning in life strategies, the author hopes to inspire other "victims" to move from victims to being survivors of bullying and mobbing.

Influence of some psychosocial factors on mobbing and its consequences among employees working with people with intellectual disabilities.

PubMed

Figueiredo-Ferraz, Hugo; Gil-Monte, Pedro R; Grau-Alberola, Ester; Llorca-Pellicer, Marta; García-Juesas, Juan A

2012-09-01

The problem of mobbing has attracted a great deal of attention over the past few years. This concern has increased the study of the phenomena, which has resulted in many scientific publications. Mobbing has been characterized as an emerging risk at work. The aim of this study was to analyse the influence of some psychosocial factors at work - role clarity, interpersonal conflicts and social support - on mobbing and its consequences - that is, inclination towards absenteeism and psychosomatic disorders. The sample included 422 employees working with people with intellectual disabilities. Structural equation modelling (SEM) was used to test the hypotheses. The Hypothesized model showed an adequate fit to data, and all hypothesized relationships were significant. The results of this study provide support for the mediator role of mobbing in the relationship between high role ambiguity, low social support and high interpersonal conflicts and psychosomatic disorders and inclination towards absenteeism. © 2012 Blackwell Publishing Ltd.

Autoethnography and cognitive adaptation: two powerful buffers against the negative consequences of workplace bullying and academic mobbing

PubMed Central

Pheko, Mpho M.

2018-01-01

ABSTRACT Work is undoubtedly fundamental to human life, social development and the economic development of individuals, organizations and nations. However, the experience of working is not always pleasant as there are many instances where relationships between workers could deteriorate, leading to practices and behaviours that could be characterized as workplace bullying and/or mobbing. The current study is an exploratory study which used autoethnography to investigate experiences of academic bullying and mobbing, and relates the practices to power structures in academic institutions. Specifically, the author shares personal experiences and explores the physical and emotional pain of being bullied and mobbed. The author also outlines how both autoethnography and meaning in life strategies were used to cope with the physical and emotional distresses associated with the negative experiences. By outlining the success of the meaning in life strategies, the author hopes to inspire other “victims” to move from victims to being survivors of bullying and mobbing. PMID:29667923

Relationships between mobbing at work and MMPI-2 personality profile, posttraumatic stress symptoms, and suicidal ideation and behavior.

PubMed

Balducci, Cristian; Alfano, Vincenzo; Fraccaroli, Franco

2009-01-01

This study investigates the relationships between the experience of mobbing at work and personality traits and symptom patterns as assessed by means of the revised version of the Minnesota Multiphasic Personality Inventory (MMPI-2). Participants were 107 workers who had contacted mental health services because they perceived themselves as victims of mobbing. In line with previous research, the results showed that the MMPI-2 mean profile was characterized by a neurotic component as evidenced by elevations of Scales 1, 2, and 3 and a paranoid component as indicated by elevation of Scale 6. Contrary to previous research, a pattern of positive and significant correlations was found between the frequency of exposure to mobbing behaviors and the MMPI-2 clinical, supplementary, and content scales, including the posttraumatic stress scale. Only about half the participants showed a severity of posttraumatic stress symptoms indicative of a posttraumatic stress disorder. The frequency of exposure to mobbing predicted suicidal ideation and behavior, with depression only partially mediating this relationship.

Flocking and self-defense: experiments and simulations of avian mobbing

NASA Astrophysics Data System (ADS)

Kane, Suzanne Amador

2011-03-01

We have performed motion capture studies in the field of avian mobbing, in which flocks of prey birds harass predatory birds. Our empirical studies cover both field observations of mobbing occurring in mid-air, where both predator and prey are in flight, and an experimental system using actual prey birds and simulated predator ``perch and wait'' strategies. To model our results and establish the effectiveness of mobbing flight paths at minimizing risk of capture while optimizing predator harassment, we have performed computer simulations using the actual measured trajectories of mobbing prey birds combined with model predator trajectories. To accurately simulate predator motion, we also measured raptor acceleration and flight dynamics, well as prey-pursuit strategies. These experiments and theoretical studies were all performed with undergraduate research assistants in a liberal arts college setting. This work illustrates how biological physics provides undergraduate research projects well-suited to the abilities of physics majors with interdisciplinary science interests and diverse backgrounds.

[Work organization and mobbing: application of cognitive methodology in medical circle].

PubMed

Martire, M R; Lo Cascio, G; Picciotto, D; Lo Cascio, N

2006-01-01

Mobbing is a phenomenon produced for the most part by factors related to work organization. During the medical control of workers in Universitary Policlinico Hospital of Palermo, we used a methodology (in advance applied with effectiveness by ISPESL in other institutions) that is able to evidence factors of work organization causing Mobbing. 338 out 2060 workers (total staff) with different professional figures were recruited. We evidenced the working classes that had more troubles about communications of business information, about interpersonal relationships at work with top manager, with other members of team and with colleagues. Particularly doctors and OTA, in worrying percentage, stated that they suffered psychological molestations. Aim of our study was to assay a procedure that, even if it doesn't identify proclaimed mobbing phenomenon, enables us to acquire information about relationships between business management and workers and organizational aspects perceiving by subordinates. A I level study about a phenomenon in expansion is very useful to recognize preventively intentionally made mobbing actions.

Verbal abuse and mobbing in pre-hospital care services in Chile.

PubMed

Campo, Varinia Rodríguez; Klijn, Tatiana Paravic

2018-01-08

to determine the perception of verbal abuse and mobbing and the associated factors of paramedic technicians (nursing assistants) and professionals (nurses, midwives, kinesiologists) in the pre-hospital care areas of three regions in the south of Chile. descriptive and correlational study was performed within the professional community and a two-stage sample of the paramedic technician population in three regions. The questionnaire "workplace violence in the health sector" (spanish version) was applied after signing the informed consent. 51.4% of professionals and 46.6% of paramedic technicians consider they have been verbally abused during last year. 17.6% of paramedic technicians and 13.5% of professionals perceived mobbing. A low percentage of these events are reported. In only one case of mobbing, the aggressor was legally penalized. No significant differences were found between the job categories and the studied regions. A high percentage of participants in each group perceived verbal abuse and non-minor percentage perceived mobbing, but most of these events are not reported.

[Mobbing: a meta-analysis and integrative model of its antecedents and consequences].

PubMed

Topa Cantisano, Gabriela; Depolo, Marco; Morales Domínguez, J Francisco

2007-02-01

Although mobbing has been extensively studied, empirical research has not led to firm conclusions regarding its antecedents and consequences, both at personal and organizational levels. An extensive literature search yielded 86 empirical studies with 93 samples. The matrix correlation obtained through meta-analytic techniques was used to test a structural equation model. Results supported hypotheses regarding organizational environmental factors as main predictors of mobbing.

Influence of Some Psychosocial Factors on Mobbing and Its Consequences among Employees Working with People with Intellectual Disabilities

ERIC Educational Resources Information Center

Figueiredo-Ferraz, Hugo; Gil-Monte, Pedro R.; Grau-Alberola, Ester; Llorca-Pellicer, Marta; Garcia-Juesas, Juan A.

2012-01-01

Background: The problem of mobbing has attracted a great deal of attention over the past few years. This concern has increased the study of the phenomena, which has resulted in many scientific publications. Mobbing has been characterized as an emerging risk at work. The aim of this study was to analyse the influence of some psychosocial factors at…

Measuring Mobility Limitations in Children with Cerebral Palsy: Interrater and Intrarater Reliability of a Mobility Questionnaire (MobQues)

ERIC Educational Resources Information Center

Van Ravesteyn, Nicolien T.; Dallmeijer, Annet J.; Scholtes, Vanessa A.; Roorda, Leo D.; Becher, Jules G.

2010-01-01

Aim: The objective of this study was to assess the reliability of a mobility questionnaire (MobQues) that was developed to measure the mobility limitations of children with cerebral palsy (CP) as rated by their parents. A clinical version of the questionnaire, consisting of 47 items (MobQues47), is available, as well as a research version with 28…

Social mobbing calls in common marmosets (Callithrix jacchus): effects of experience and associated cortisol levels.

PubMed

Clara, Elena; Tommasi, Luca; Rogers, Lesley J

2008-04-01

We compared the mobbing response to model snakes of two groups of captive-born common marmosets (Callithrix jacchus) differing in genetic relatedness, age and past experience. Mobbing vocalisations (tsik calls), other mobbing behaviour and attention to the stimulus were recorded for 2 min. intervals pre-exposure, during exposure to various stimuli and post-exposure. Marmosets in one group were vocally reactive to all stimuli, although more so to one particular stimulus resembling rearing snakes and modified images of it, whereas the marmosets in a younger and genetically unrelated group attended to the stimuli but made very few mobbing calls. The parent stock of the first group had suffered stress in early life and had developed a phobic response to a specific stimulus, which they had transmitted to their offspring. A third group, matching the older group in age range but genetically unrelated, was also found to be unresponsive to the stimulus that elicited the strongest response in the first group. Cortisol levels in samples of hair were assayed and a significant negative correlation was found between the number of tsik calls made during presentation of the stimuli and the cortisol level, showing that mobbing behaviour/behavioural reactivity is associated with low levels of physiological stress.

Assessment of Turkish junior male physicians’ exposure to mobbing behavior

PubMed Central

Sahin, Bayram; Cetin, Mehmet; Cimen, Mesut; Yildiran, Nuri

2012-01-01

Aim To determine the extent of Turkish junior male physicians’ exposure to mobbing behavior and its correlation with physicians' characteristics. Methods The study included physicians recruited for compulsory military service in April 2009. No sampling method was used, questionnaires were delivered to all physicians, and 278 of 292 (95%) questionnaires were returned. We used Leymann Inventory of Psychological Terror including 45 items for data collection and structural equation model for data analysis. Results A total of 87.7% of physicians experienced mobbing behavior. Physicians who worked more than 40 hours a week, single physicians, physicians working in university hospitals and private hospitals, and physicians who did not have occupational commitment were more exposed to mobbing (P < 0.05). Mobbing was not associated with specialty status, service period, age, and personality variables (P > 0.05). All goodness-of- fit indices of the model were acceptable (χ2 = 1.449, normed fit index = 0.955, Tucker Lewis index = 0.980, comparative fit index = 0.985, and root mean square error of approximation = 0.040). Conclusions Workplace mobbing is a critical problem for junior male physicians in Turkey. We suggest an introduction of a reporting system and education activities for physicians in high-risk groups. PMID:22911529

[Comparison between the risk of mobbing at work and conditions of job strain and effort-reward imbalance in relation to stress-related disorders: a study in the public administration].

PubMed

Balducci, C; Fraccaroli, E

2013-01-01

A limitation of previous research on mobbing at work was that the individual consequences of the phenomenon were often assessed on 'clinical' samples of victims. Studies in organizations are less numerous and those available rarely evaluated the potential effect of mobbing over and above that of other psychosocial factors which provided robust evidence of adverse health effects. The relationship between exposure to mobbing and stress-related psychophysical conditions was investigated taking in consideration the possible concomitant exposure to job strain and effort-reward imbalance. Cross-sectional study on public administration administrative employees (No. = 538, 48% women). The psychosocial factors considered were assessed by means of well known and validated scales. The four health outcomes considered were psychological caseness (as operationalized by means of the general health questionnaire-12-item version), depression, gastritis and colitis/irritable colon syndrome as indicated by having reported a medical diagnosis of such conditions. Covariates: gender, age, body mass index, smoking habits and experience of a traumatic event in the last year. Analysis consisted of a series of logistic regressions. Exposure to mobbing was significantly associated with all the outcomes considered over and above the covariates. The inclusion in the models of job strain and effort-reward imbalance did not substantially alter the results. The relationship between mobbing at work and health outcomes is not confounded by concomitant exposure to job strain and effort-reward imbalance. These results offer further confirmation of the uniqueness of mobbing as a psychosocial risk factor.

Differential effects of unilateral olfactory deprivation on noradrenergic and cholinergic systems in the main olfactory bulb of the rat.

PubMed

Gómez, C; Briñón, J G; Colado, M I; Orio, L; Vidal, M; Barbado, M V; Alonso, J R

2006-09-15

The lack of environmental olfactory stimulation produced by sensory deprivation causes significant changes in the deprived olfactory bulb. Olfactory transmission in the main olfactory bulb (MOB) is strongly modulated by centrifugal systems. The present report examines the effects of unilateral deprivation on the noradrenergic and cholinergic centrifugal systems innervating the MOB. The morphology, distribution, and density of positive axons were studied in the MOBs of control and deprived rats, using dopamine-beta-hydroxylase (DBH)-immunohistochemistry and acetylcholinesterase (AChE) histochemistry in serial sections. Catecholamine content was compared among the different groups of MOBs (control, contralateral, and ipsilateral to the deprivation) using high-performance liquid chromatography analysis. Sensory deprivation revealed that the noradrenergic system developed adaptive plastic changes after olfactory deprivation, including important modifications in its fiber density and distribution, while no differences in cholinergic innervation were observed under the same conditions. The noradrenergic system underwent an important alteration in the glomerular layer, in which some glomeruli showed a dense noradrenergic innervation that was not detected in control animals. The DBH-positive glomeruli with the highest noradrenergic fiber density were compared with AChE-stained sections and it was observed that the strongly noradrenergic-innervated glomeruli were always atypical glomeruli (characterized by their strong degree of cholinergic innervation). In addition to the morphological findings, our biochemical data revealed that olfactory deprivation caused a decrease in the content of dopamine and its metabolite 3,4-dihydroxyphenylacetic acid in the ipsilateral MOB in comparison to the contralateral and control MOBs, together with an increase in noradrenaline levels in both the ipsilateral and contralateral MOBs. Our results show that regulation of the noradrenergic centrifugal system in the MOB depends on environmental olfactory stimulation and that it is highly reactive to sensory deprivation. By contrast, the cholinergic system is fairly stable and does not exhibit clear changes after the loss of sensory inputs.

MOBBED: a computational data infrastructure for handling large collections of event-rich time series datasets in MATLAB

PubMed Central

Cockfield, Jeremy; Su, Kyungmin; Robbins, Kay A.

2013-01-01

Experiments to monitor human brain activity during active behavior record a variety of modalities (e.g., EEG, eye tracking, motion capture, respiration monitoring) and capture a complex environmental context leading to large, event-rich time series datasets. The considerable variability of responses within and among subjects in more realistic behavioral scenarios requires experiments to assess many more subjects over longer periods of time. This explosion of data requires better computational infrastructure to more systematically explore and process these collections. MOBBED is a lightweight, easy-to-use, extensible toolkit that allows users to incorporate a computational database into their normal MATLAB workflow. Although capable of storing quite general types of annotated data, MOBBED is particularly oriented to multichannel time series such as EEG that have event streams overlaid with sensor data. MOBBED directly supports access to individual events, data frames, and time-stamped feature vectors, allowing users to ask questions such as what types of events or features co-occur under various experimental conditions. A database provides several advantages not available to users who process one dataset at a time from the local file system. In addition to archiving primary data in a central place to save space and avoid inconsistencies, such a database allows users to manage, search, and retrieve events across multiple datasets without reading the entire dataset. The database also provides infrastructure for handling more complex event patterns that include environmental and contextual conditions. The database can also be used as a cache for expensive intermediate results that are reused in such activities as cross-validation of machine learning algorithms. MOBBED is implemented over PostgreSQL, a widely used open source database, and is freely available under the GNU general public license at http://visual.cs.utsa.edu/mobbed. Source and issue reports for MOBBED are maintained at http://vislab.github.com/MobbedMatlab/ PMID:24124417

MOBBED: a computational data infrastructure for handling large collections of event-rich time series datasets in MATLAB.

PubMed

Cockfield, Jeremy; Su, Kyungmin; Robbins, Kay A

2013-01-01

Experiments to monitor human brain activity during active behavior record a variety of modalities (e.g., EEG, eye tracking, motion capture, respiration monitoring) and capture a complex environmental context leading to large, event-rich time series datasets. The considerable variability of responses within and among subjects in more realistic behavioral scenarios requires experiments to assess many more subjects over longer periods of time. This explosion of data requires better computational infrastructure to more systematically explore and process these collections. MOBBED is a lightweight, easy-to-use, extensible toolkit that allows users to incorporate a computational database into their normal MATLAB workflow. Although capable of storing quite general types of annotated data, MOBBED is particularly oriented to multichannel time series such as EEG that have event streams overlaid with sensor data. MOBBED directly supports access to individual events, data frames, and time-stamped feature vectors, allowing users to ask questions such as what types of events or features co-occur under various experimental conditions. A database provides several advantages not available to users who process one dataset at a time from the local file system. In addition to archiving primary data in a central place to save space and avoid inconsistencies, such a database allows users to manage, search, and retrieve events across multiple datasets without reading the entire dataset. The database also provides infrastructure for handling more complex event patterns that include environmental and contextual conditions. The database can also be used as a cache for expensive intermediate results that are reused in such activities as cross-validation of machine learning algorithms. MOBBED is implemented over PostgreSQL, a widely used open source database, and is freely available under the GNU general public license at http://visual.cs.utsa.edu/mobbed. Source and issue reports for MOBBED are maintained at http://vislab.github.com/MobbedMatlab/

Active hexagonally segmented mirror to investigate new optical phasing technologies for segmented telescopes.

PubMed

Gonté, Frédéric; Dupuy, Christophe; Luong, Bruno; Frank, Christoph; Brast, Roland; Sedghi, Baback

2009-11-10

The primary mirror of the future European Extremely Large Telescope will be equipped with 984 hexagonal segments. The alignment of the segments in piston, tip, and tilt within a few nanometers requires an optical phasing sensor. A test bench has been designed to study four different optical phasing sensor technologies. The core element of the test bench is an active segmented mirror composed of 61 flat hexagonal segments with a size of 17 mm side to side. Each of them can be controlled in piston, tip, and tilt by three piezoactuators with a precision better than 1 nm. The context of this development, the requirements, the design, and the integration of this system are explained. The first results on the final precision obtained in closed-loop control are also presented.

LISA pathfinder optical interferometry

NASA Astrophysics Data System (ADS)

Braxmaier, Claus; Heinzel, Gerhard; Middleton, Kevin F.; Caldwell, Martin E.; Konrad, W.; Stockburger, H.; Lucarelli, S.; te Plate, Maurice B.; Wand, V.; Garcia, A. C.; Draaisma, F.; Pijnenburg, J.; Robertson, D. I.; Killow, Christian; Ward, Harry; Danzmann, Karsten; Johann, Ulrich A.

2004-09-01

The LISA Technology Package (LTP) aboard of LISA pathfinder mission is dedicated to demonstrate and verify key technologies for LISA, in particular drag free control, ultra-precise laser interferometry and gravitational sensor. Two inertial sensor, the optical interferometry in between combined with the dimensional stable Glass ceramic Zerodur structure are setting up the LTP. The validation of drag free operation of the spacecraft is planned by measuring laser interferometrically the relative displacement and tilt between two test masses (and the optical bench) with a noise levels of 10pm/√Hz and 10 nrad/√Hz between 3mHz and 30mHz. This performance and additionally overall environmental tests was currently verified on EM level. The OB structure is able to support two inertial sensors (≍17kg each) and to withstand 25 g design loads as well as 0...40°C temperature range. Optical functionality was verified successfully after environmental tests. The engineering model development and manufacturing of the optical bench and interferometry hardware and their verification tests will be presented.

In vitro comparative optical bench analysis of a spherical and aspheric optic design of the same IOL model.

PubMed

Tandogan, Tamer; Auffarth, Gerd U; Choi, Chul Y; Liebing, Stephanie; Mayer, Christian; Khoramnia, Ramin

2017-02-08

To analyse objective optical properties of the spherical and aspheric design of the same intraocular lens (IOL) model using optical bench analysis. This study entailed a comparative analysis of 10 spherical C-flex 570 C and 10 aspheric C-flex 970 C IOLs (Rayner Intraocular Lenses Ltd., Hove, UK) of 26 diopters [D] using an optical bench (OptiSpheric, Trioptics, Germany). In all lenses, we evaluated the modulation transfer function (MTF) at 50 lp/mm and 100 lp/mm and the Strehl Ratio using a 3-mm (photopic) and 4.5-mm (mesopic) aperture. At 50 lp/mm, the MTF values were 0.713/0.805 (C-flex 570 C/C-flex 970 C) for a 3-mm aperture and 0.294/0.591 for a 4.5-mm aperture. At 100 lp/mm, the MTF values were 0.524/0.634 for a 3-mm aperture and 0.198/0.344 for a 4.5-mm aperture. The Strehl Ratio was 0.806/0.925 and 0.237/0.479 for a 3-mm and 4.5-mm aperture respectively. A Mann-Whitney U test revealed all intergroup differences to be statistically significant (p < 0.01). The aspheric IOL design achieved higher MTF values than the spherical design of the same IOL for both apertures. Moreover, the differences between the two designs of the IOL were more prominent for larger apertures. This suggests that the evaluated IOL provides enhanced optical quality to patients with larger pupils or working under mesopic conditions.

International Space Station -- Fluid Physics Ra;ck

NASA Technical Reports Server (NTRS)

2000-01-01

The optical bench for the Fluids Integrated Rack section of the Fluids and Combustion Facility (FCF) is shown extracted for servicing and with the optical bench rotated 90 degrees for access to the rear elements. The FCF will be installed, in phases, in the Destiny, the U.S. Laboratory Module of the International Space Station (ISS), and will accommodate multiple users for a range of investigations. This is an engineering mockup; the flight hardware is subject to change as designs are refined. The FCF is being developed by the Microgravity Science Division (MSD) at the NASA Glenn Research Center. (Photo credit: NASA/Marshall Space Flight Center)

Optical bench development for LISA

NASA Astrophysics Data System (ADS)

d'Arcio, L.; Bogenstahl, J.; Dehne, M.; Diekmann, C.; Fitzsimons, E. D.; Fleddermann, R.; Granova, E.; Heinzel, G.; Hogenhuis, H.; Killow, C. J.; Perreur-Lloyd, M.; Pijnenburg, J.; Robertson, D. I.; Shoda, A.; Sohmer, A.; Taylor, A.; Tröbs, M.; Wanner, G.; Ward, H.; Weise, D.

2017-11-01

For observation of gravitational waves at frequencies between 30 μHz and 1 Hz, the LISA mission will be implemented in a triangular constellation of three identical spacecraft, which are mutually linked by laser interferometry in an active transponder scheme over a 5 million kilometer arm length. On the end point of each laser link, remote and local beam metrology with respect to inertial proof masses inside the spacecraft is realized by the LISA Optical Bench. It implements further- more various ancillary functions such as point-ahead correction, acquisition sensing, transmit beam conditioning, and laser redundancy switching. A comprehensive design of the Optical Bench has been developed, which includes all of the above mentioned functions and at the same time ensures manufacturability on the basis of hydroxide catalysis bonding, an ultrastable integration technology already perfected in the context of LISA's technology demonstrator mission LISA Pathfinder. Essential elements of this design have been validated by dedicated pre-investigations. These include the demonstration of polarizing heterodyne interferometry at the required Picometer and Nanoradian performance levels, the investigation of potential non-reciprocal noise sources in the so-called backlink fiber, as well as the development of a laser redundancy switch breadboard.

Photonic integrated circuits based on novel glass waveguides and devices

NASA Astrophysics Data System (ADS)

Zhang, Yaping; Zhang, Deng; Pan, Weijian; Rowe, Helen; Benson, Trevor; Loni, Armando; Sewell, Phillip; Furniss, David; Seddon, Angela B.

2006-04-01

Novel materials, micro-, nano-scale photonic devices, and 'photonic systems on a chip' have become important focuses for global photonics research and development. This interest is driven by the rapidly growing demand for broader bandwidth in optical communication networks, and higher connection density in the interconnection area, as well as a wider range of application areas in, for example, health care, environment monitoring and security. Taken together, chalcogenide, heavy metal fluoride and fluorotellurite glasses offer transmission from ultraviolet to mid-infrared, high optical non-linearity and the ability to include active dopants, offering the potential for developing optical components with a wide range of functionality. Moreover, using single-mode large cross-section glass-based waveguides as an optical integration platform is an elegant solution for the monolithic integration of optical components, in which the glass-based structures act both as waveguides and as an optical bench for integration. We have previously developed a array of techniques for making photonic integrated circuits and devices based on novel glasses. One is fibre-on-glass (FOG), in which the fibres can be doped with different active dopants and pressed onto a glass substrate with a different composition using low-temperature thermal bonding under mechanical compression. Another is hot-embossing, in which a silicon mould is placed on top of a glass sample, and hot-embossing is carried out by applying heat and pressure. In this paper the development of a fabrication technique that combines the FOG and hot-embossing procedures to good advantage is described. Simulation and experimental results are presented.

[Psychiatric aspects in workers subject to mobbing].

PubMed

Bernabei, A; Gebhardt, Eva; Petrucci, Manuela

2005-01-01

Mobbing in the language of ethologists means a particular behaviour of a group of animals consisting of several members forming an alliance against a single animal, in order to eliminate this animal away from the group. This term has been adopted in current usage to mean a kind of relationship at the workplace that, by aggressive and underhand means, aims at influencing or expelling the person. The term "bossing" is used to indicate a negative action, under the meaning described above, made by one or more senior persons, or possibly by the employer. In the Italian Parliament, under the current legislature, several bills are pending regarding this problem. Besides the aspects of topical interest in the problem, there are first and foremost the different kinds of reaction-adaptation to mobbing, according to the type of individual internal working models in action, that can be anxious/avoiding, anxious/resistant or disorganised. The purpose of our study was a clinical evaluation of the different ways of adaptation-reaction to a mobbing-type relationship at the workplace, and of the type of internal working models found among the examined patients. A clinical interview was carried out with 40 patients who, over a period of 12 months of observation, came to request a clinical assessment, for medical-legal reasons, of their psycho-pathological state and ways to react to adverse situations at the workplace, such as a mobbing or bossing. Besides the psychological and relational effects of mobbing, the reactions of the examined subjects to mobbing are also described, considering also the different cognitive self-organization possibilities, according to the individual internal working model, regarding patterns of attachment in adult age. The most frequent internal working model seems to be the one related to resistant attachment, followed by the avoidance and lastly--rarely--the disorganized model. Furthermore we observed among these subjects a certain deficit in meta-cognitive capacity of self reflection and decentralization. Cognitive therapy is proposed as the most effective of therapeutic approaches, associated with symptomatic psycho-pharmacological therapy as needed. Initial clinical results on cognitive therapy of these patients are reported. The individual type of internal working model seems to be the critical element in mobbing reaction and, besides specific intervention plans regarding relationship in the workplace, individual psychotherapy appears to be the best instrument of treatment and prevention of the psychopathologic effects caused by mobbing.

4 channel × 10 Gb/s bidirectional optical subassembly using silicon optical bench with precise passive optical alignment.

PubMed

Kang, Eun Kyu; Lee, Yong Woo; Ravindran, Sooraj; Lee, Jun Ki; Choi, Hee Ju; Ju, Gun Wu; Min, Jung Wook; Song, Young Min; Sohn, Ik-Bu; Lee, Yong Tak

2016-05-16

We demonstrate an advanced structure for optical interconnect consisting of 4 channel × 10 Gb/s bidirectional optical subassembly (BOSA) formed using silicon optical bench (SiOB) with tapered fiber guiding holes (TFGHs) for precise and passive optical alignment of vertical-cavity surface-emitting laser (VCSEL)-to-multi mode fiber (MMF) and MMF-to-photodiode (PD). The co-planar waveguide (CPW) transmission line (Tline) was formed on the backside of silicon substrate to reduce the insertion loss of electrical data signal. The 4 channel VCSEL and PD array are attached at the end of CPW Tline using a flip-chip bonder and solder pad. The 12-channel ribbon fiber is simply inserted into the TFGHs of SiOB and is passively aligned to the VCSEL and PD in which no additional coupling optics are required. The fabricated BOSA shows high coupling efficiency and good performance with the clearly open eye patterns and a very low bit error rate of less than 10^-12 order at a data rate of 10 Gb/s with a PRBS pattern of 2³¹-1.

Life Science-Related Physics Laboratory on Geometrical Optics

ERIC Educational Resources Information Center

Edwards, T. H.; And Others

1975-01-01

Describes a laboratory experiment on geometrical optics designed for life science majors in a noncalculus introductory physics course. The thin lens equation is used by the students to calculate the focal length of the lens necessary to correct a myopic condition in an optical bench simulation of a human eye. (Author/MLH)

A direct main olfactory bulb projection to the ‘vomeronasal’ amygdala in female mice selectively responds to volatile pheromones from males

PubMed Central

Kang, Ningdong; Baum, Michael J.; Cherry, James A.

2009-01-01

The main olfactory system, like the accessory olfactory system, responds to pheromones involved in social communication. Whereas pheromones detected by the accessory system are transmitted to the hypothalamus via the medial (‘vomeronasal’) amygdala, the pathway by which pheromones are detected and transmitted by the main system is not well understood. We examined in female mice whether a direct projection from mitral/tufted (M/T) cells in the main olfactory bulb (MOB) to the medial amygdala exists, and whether medial amygdala-projecting M/T cells are activated by volatile urinary odors from conspecifics or a predator (cat). Simultaneous anterograde tracing using Phaseolus vulgaris leucoagglutinin and Fluoro-Ruby placed in the MOB and accessory olfactory bulb (AOB), respectively, revealed that axons of MOB M/T cells projected to superficial laminae of layer Ia in anterior and posterodorsal subdivisions of the medial amygdala, whereas projection neurons from the AOB sent axons to non-overlapping, deeper layer Ia laminae of the same subdivisions. Placement of the retrograde tracer cholera toxin B into the medial amygdala labeled M/T cells that were concentrated in the ventral MOB. Urinary volatiles from male mice, but not from female conspecifics or cat, induced Fos in medial amygdala-projecting MOB M/T cells of female subjects, suggesting that information about male odors is transmitted directly from the MOB to the ‘vomeronasal’ amygdala. The presence of a direct MOB-to-medial amygdala pathway in mice and other mammals could enable volatile, opposite-sex pheromones to gain privileged access to diencephalic structures that control mate recognition and reproduction. PMID:19187265

Olfactory Bulb Deep Short-Axon Cells Mediate Widespread Inhibition of Tufted Cell Apical Dendrites

PubMed Central

LaRocca, Greg

2017-01-01

In the main olfactory bulb (MOB), the first station of sensory processing in the olfactory system, GABAergic interneuron signaling shapes principal neuron activity to regulate olfaction. However, a lack of known selective markers for MOB interneurons has strongly impeded cell-type-selective investigation of interneuron function. Here, we identify the first selective marker of glomerular layer-projecting deep short-axon cells (GL-dSACs) and investigate systematically the structure, abundance, intrinsic physiology, feedforward sensory input, neuromodulation, synaptic output, and functional role of GL-dSACs in the mouse MOB circuit. GL-dSACs are located in the internal plexiform layer, where they integrate centrifugal cholinergic input with highly convergent feedforward sensory input. GL-dSAC axons arborize extensively across the glomerular layer to provide highly divergent yet selective output onto interneurons and principal tufted cells. GL-dSACs are thus capable of shifting the balance of principal tufted versus mitral cell activity across large expanses of the MOB in response to diverse sensory and top-down neuromodulatory input. SIGNIFICANCE STATEMENT The identification of cell-type-selective molecular markers has fostered tremendous insight into how distinct interneurons shape sensory processing and behavior. In the main olfactory bulb (MOB), inhibitory circuits regulate the activity of principal cells precisely to drive olfactory-guided behavior. However, selective markers for MOB interneurons remain largely unknown, limiting mechanistic understanding of olfaction. Here, we identify the first selective marker of a novel population of deep short-axon cell interneurons with superficial axonal projections to the sensory input layer of the MOB. Using this marker, together with immunohistochemistry, acute slice electrophysiology, and optogenetic circuit mapping, we reveal that this novel interneuron population integrates centrifugal cholinergic input with broadly tuned feedforward sensory input to modulate principal cell activity selectively. PMID:28003347

Effects of a Community-Based Fall Management Program on Medicare Cost Savings.

PubMed

Ghimire, Ekta; Colligan, Erin M; Howell, Benjamin; Perlroth, Daniella; Marrufo, Grecia; Rusev, Emil; Packard, Michael

2015-12-01

Fall-related injuries and health risks associated with reduced mobility or physical inactivity account for significant costs to the U.S. healthcare system. The widely disseminated lay-led A Matter of Balance (MOB) program aims to help older adults reduce their risk of falling and associated activity limitations. This study examined effects of MOB participation on health service utilization and costs for Medicare beneficiaries, as a part of a larger effort to understand the value of community-based prevention and wellness programs for Medicare. A controlled retrospective cohort study was conducted in 2012-2013, using 2007-2011 MOB program data and 2006-2013 Medicare data. It investigated program effects on falls and fall-related fractures, and health service utilization and costs (standardized to 2012 dollars), of 6,136 Medicare beneficiaries enrolled in MOB from 2007 through 2011. A difference-in-differences analysis was employed to compare outcomes of MOB participants with matched controls. MOB participation was associated with total medical cost savings of $938 per person (95% CI=$379, $1,498) at 1 year. Savings per person amounted to $517 (95% CI=$265, $769) for unplanned hospitalizations; $81 for home health care (95% CI=$20, $141); and $234 (95% CI=$55, $413) for skilled nursing facility care. Changes in the incidence of falls or fall-related fractures were not detected, suggesting that cost savings accrue through other mechanisms. This study suggests that MOB and similar prevention programs have the potential to reduce Medicare costs. Further research accounting for program delivery costs would help inform the development of Medicare-covered preventive benefits. Copyright © 2015 American Journal of Preventive Medicine. All rights reserved.

[Mobbing as the syndrome of destructive professiogenesis].

PubMed

Sidorov, P I

2013-01-01

Mobbing has entered reference books as the syndrome including harassment and insult of employees in the workplaces for the purpose of constraint for dismissal. In the framework of the synergetic methodology, fractal dynamics of mobbing sociogenesis, psychogenesis and somatogenesis have been separated. Approaches to early diagnostics and prevention in the framework of the strategies of adaptive professiogenesis formation have been explained. A system approach to development of preventive-correctional and treatment-rehabilitation medicopsychosocial programs has been proposed.

Methane turnover and methanotrophic communities in arctic aquatic ecosystems of the Lena Delta, Northeast Siberia.

PubMed

Osudar, Roman; Liebner, Susanne; Alawi, Mashal; Yang, Sizhong; Bussmann, Ingeborg; Wagner, Dirk

2016-08-01

Large amounts of organic carbon are stored in Arctic permafrost environments, and microbial activity can potentially mineralize this carbon into methane, a potent greenhouse gas. In this study, we assessed the methane budget, the bacterial methane oxidation (MOX) and the underlying environmental controls of arctic lake systems, which represent substantial sources of methane. Five lake systems located on Samoylov Island (Lena Delta, Siberia) and the connected river sites were analyzed using radiotracers to estimate the MOX rates, and molecular biology methods to characterize the abundance and the community composition of methane-oxidizing bacteria (MOB). In contrast to the river, the lake systems had high variation in the methane concentrations, the abundance and composition of the MOB communities, and consequently, the MOX rates. The highest methane concentrations and the highest MOX rates were detected in the lake outlets and in a lake complex in a flood plain area. Though, in all aquatic systems, we detected both, Type I and II MOB, in lake systems, we observed a higher diversity including MOB, typical of the soil environments. The inoculation of soil MOB into the aquatic systems, resulting from permafrost thawing, might be an additional factor controlling the MOB community composition and potentially methanotrophic capacity. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

People and the labour market: integration and differences.

PubMed

Fattorini, E; Campo, G

2006-01-01

This survey aims at identifying methods and procedures to prevent possible gender discrimination at the workplace. It is intended to: a) establish whether mobbing is present in the companies involved in this survey; b) verify whether the aetiology and mobbing dynamics are the same for men and women. This survey involved 887 persons in eight companies, operating in different economic sectors, and located in the VIII, IX and X Municipalities, in the south east area of Rome. The collected data seem to exclude the presence of evident psychological terrorism, even though there can be sound reasons for it to develop: bad job organization, lack of personnel policy and an increase in the stress level, all of which are the most common elements paving the way for mobbing. The results of the survey reveal a highly dysfunctional working situation even though they do not comply with the characteristic criteria of psychological violence, known as mobbing. In Italy, a major organizational restructuring (privatisation, mergers, etc), as well as the introduction of new types of jobs, has contributed to turn mobbing from an occasional phenomenon into a social problem about which everyone is concerned (anti-mobbing centres, specialized clinics, bills, etc). This study focuses on some aspects of the organizational work structure which would otherwise usually be disregarded at the risk of causing uneasiness and/or stress pathologies.

No association between month of birth and biliary atresia in a country with tropical climate.

PubMed

Tanpowpong, Pornthep; Lertudomphonwanit, Chatmanee; Phuapradit, Pornpimol; Treepongkaruna, Suporn

2018-06-04

Children with biliary atresia (BA) born in countries with temperate climate showed month-of-birth (MoB) predilection during cooler months. To date, no study on the MoB-BA association has been performed in a tropical country. Our aim was to define MoB variation in children with BA in a tropical country. We studied 150 children diagnosed with BA between January 1996 and April 2015 at a teaching hospital. MoB was defined by two categories based on the precipitation: rain and dry, and three categories based on the air temperature: high, average and low. We applied the country's population data on the number of births in each period as the expected proportions of birth. A slightly higher proportion of BA children was born in the rainy months (52.7%); however, the difference was not significant compared to the general population's birth (P = 0.87). For the MoB based on the air temperature, no statistically significant difference was noted. Males with BA seemed to have a greater MoB variation compared to females, but this did not reach statistical significance. We could not find an association between MoB and BA in a tropical country. Multinational studies may aid in understanding the MoB-BA association in the tropical countries. © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

[Mobbing and its effects on health. the experience of the "Clinica del Lavoro Luigi Devoto" in Milan].

PubMed

Punzi, Silvia; Cassitto, Maria Grazia; Castellini, Giovanna; Costa, G; Gilioli, R

2007-01-01

There is increasing interest in research, prevention and management of mobbing in the field of occupational psychosocial risks. To describe mobbing and its health effects by analysis of the cases examined from 1997 to 2003 at the Department of Occupational Health "Clinica del Lavoro Luigi Devoto" in Milan. A total of 226 clinical records of patients who reported a mobbing situation when undergoing medical examination were selected out of 2455 patients examined for stress-related disorders. The percentage of women was higher (53.1%) than in men (46.9%) with a prevalent age range of 35-54 years. There was a great variety of jobs, especially white-collars and workers in large service companies. In one third of the cases, mobbing occurred within 4 years from beginning of employment and mostly after company reorganization and management changes. The most frequent negative acts included social isolation and demotion. The most frequent symptoms were exhaustion, sleep, mood and sexual disorders. The number of symptoms was not related to the duration of mobbing but to the number and frequency of negative actions. 61.1% of the subjects took psychotropic drugs. Occupational health physicians play an essential role in primary prevention (information on occupational risks) and in early diagnosis and rehabilitation and could act as mediators between workers and enterprises.

Verbal abuse and mobbing in pre-hospital care services in Chile

PubMed Central

Campo, Varinia Rodríguez; Klijn, Tatiana Paravic

2018-01-01

ABSTRACT Objective: to determine the perception of verbal abuse and mobbing and the associated factors of paramedic technicians (nursing assistants) and professionals (nurses, midwives, kinesiologists) in the pre-hospital care areas of three regions in the south of Chile. Methods: descriptive and correlational study was performed within the professional community and a two-stage sample of the paramedic technician population in three regions. The questionnaire “workplace violence in the health sector” (spanish version) was applied after signing the informed consent. Results: 51.4% of professionals and 46.6% of paramedic technicians consider they have been verbally abused during last year. 17.6% of paramedic technicians and 13.5% of professionals perceived mobbing. A low percentage of these events are reported. In only one case of mobbing, the aggressor was legally penalized. No significant differences were found between the job categories and the studied regions. Conclusions: A high percentage of participants in each group perceived verbal abuse and non-minor percentage perceived mobbing, but most of these events are not reported. PMID:29319741

Structural basis of a histidine-DNA nicking/joining mechanism for gene transfer and promiscuous spread of antibiotic resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pluta, Radoslaw; Boer, D. Roeland; Lorenzo-Diaz, Fabian

Relaxases are metal-dependent nucleases that break and join DNA for the initiation and completion of conjugative bacterial gene transfer. Conjugation is the main process through which antibiotic resistance spreads among bacteria, with multidrug-resistant staphylococci and streptococci infections posing major threats to human health. The MOB V family of relaxases accounts for approximately 85% of all relaxases found in Staphylococcus aureus isolates. Here, we present six structures of the MOB V relaxase MobM from the promiscuous plasmid pMV158 in complex with several origin of transfer DNA fragments. A combined structural, biochemical, and computational approach reveals that MobM follows a previously uncharacterizedmore » histidine/metal-dependent DNA processing mechanism, which involves the formation of a covalent phosphoramidate histidine-DNA adduct for cell-to-cell transfer. In conclusion, we discuss how the chemical features of the high-energy phosphorus-nitrogen bond shape the dominant position of MOB V histidine relaxases among small promiscuous plasmids and their preference toward Gram-positive bacteria.« less

Structural basis of a histidine-DNA nicking/joining mechanism for gene transfer and promiscuous spread of antibiotic resistance

DOE PAGES

Pluta, Radoslaw; Boer, D. Roeland; Lorenzo-Diaz, Fabian; ...

2017-07-24

Relaxases are metal-dependent nucleases that break and join DNA for the initiation and completion of conjugative bacterial gene transfer. Conjugation is the main process through which antibiotic resistance spreads among bacteria, with multidrug-resistant staphylococci and streptococci infections posing major threats to human health. The MOB V family of relaxases accounts for approximately 85% of all relaxases found in Staphylococcus aureus isolates. Here, we present six structures of the MOB V relaxase MobM from the promiscuous plasmid pMV158 in complex with several origin of transfer DNA fragments. A combined structural, biochemical, and computational approach reveals that MobM follows a previously uncharacterizedmore » histidine/metal-dependent DNA processing mechanism, which involves the formation of a covalent phosphoramidate histidine-DNA adduct for cell-to-cell transfer. In conclusion, we discuss how the chemical features of the high-energy phosphorus-nitrogen bond shape the dominant position of MOB V histidine relaxases among small promiscuous plasmids and their preference toward Gram-positive bacteria.« less

Low vibration microminiature split Stirling cryogenic cooler for infrared aerospace applications

NASA Astrophysics Data System (ADS)

Veprik, A.; Zechtzer, S.; Pundak, N.; Kirkconnel, C.; Freeman, J.; Riabzev, S.

2011-06-01

The operation of the thermo-mechanical unit of a cryogenic cooler may originate a resonant excitation of the spacecraft frame, optical bench or components of the optical train. This may result in degraded functionality of the inherently vibration sensitive space-borne infrared imager directly associated with the cooler or neighboring instrumentation typically requiring a quiet micro-g environment. The best practice for controlling cooler induced vibration relies on the principle of active momentum cancellation. In particular, the pressure wave generator typically contains two oppositely actuated piston compressors, while the single piston expander is counterbalanced by an auxiliary active counter-balancer. Active vibration cancellation is supervised by a dedicated DSP feed-forward controller, where the error signals are delivered by the vibration sensors (accelerometers or load cells). This can result in oversized, overweight and overpriced cryogenic coolers with degraded electromechanical performance and impaired reliability. The authors are advocating a reliable, compact, cost and power saving approach capitalizing on the combined application of a passive tuned dynamic absorber and a low frequency vibration isolator. This concept appears to be especially suitable for low budget missions involving mini and micro satellites, where price, size, weight and power consumption are of concern. The authors reveal the results of theoretical study and experimentation on the attainable performance using a fullscale technology demonstrator relying on a Ricor model K527 tactical split Stirling cryogenic cooler. The theoretical predictions are in fair agreement with the experimental data. From experimentation, the residual vibration export is quite suitable for demanding wide range of aerospace applications. The authors give practical recommendations on heatsinking and further maximizing performance.

Numerical modeling of immiscible two-phase flow in micro-models using a commercial CFD code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crandall, Dustin; Ahmadia, Goodarz; Smith, Duane H.

2009-01-01

Off-the-shelf CFD software is being used to analyze everything from flow over airplanes to lab-on-a-chip designs. So, how accurately can two-phase immiscible flow be modeled flowing through some small-scale models of porous media? We evaluate the capability of the CFD code FLUENT{trademark} to model immiscible flow in micro-scale, bench-top stereolithography models. By comparing the flow results to experimental models we show that accurate 3D modeling is possible.

Compact system with handheld microfabricated optoelectronic probe for needle-based tissue sensing applications

NASA Astrophysics Data System (ADS)

Lee, Seung Yup; Na, Kyounghwan; Pakela, Julia M.; Scheiman, James M.; Yoon, Euisik; Mycek, Mary-Ann

2017-02-01

We present the design, development, and bench-top verification of an innovative compact clinical system including a miniaturized handheld optoelectronic sensor. The integrated sensor was microfabricated with die-level light-emitting diodes and photodiodes and fits into a 19G hollow needle (internal diameter: 0.75 mm) for optical sensing applications in solid tissues. Bench-top studies on tissue-simulating phantoms have verified system performance relative to a fiberoptic based tissue spectroscopy system. With dramatically reduced system size and cost, the technology affords spatially configurable designs for optoelectronic light sources and detectors, thereby enabling customized sensing configurations that would be impossible to achieve with needle-based fiber-optic probes.

Biochemical Process Development and Integration | Bioenergy | NREL

Science.gov Websites

Process Development We develop and scale fermentation processes that produce fuels and chemicals from guide experimental designs. Our newly updated fermentation laboratory houses 38 bench-scale fermentors current projects cover the fermentation spectrum including anaerobic, micro-aerobic, aerobic, and gas-to

Mobbing and Its Impact on Interpersonal Relationships at the Workplace.

PubMed

da Silva João, Ana Lúcia; Saldanha Portelada, António Fernando

2016-08-01

Mobbing is characterized by the repetition, over a long period of time, of hostile behavior and unethical conduct carried out by a hierarchical superior or co-worker, against someone's physic and mental integrity, endangering one's job or disturbing the work environment. This current investigative study intends to assess the existence, frequency, and intensity of mobbing within the Portuguese nurse population, as well as its impact on their well-being and interpersonal relationships. The study carried out was quantitative, correlational, and cross-sectional. A questionnaire was used as the form to collect data. The questionnaire was sent out to 11 institutions in Portugal which were chosen at random, and it was also made available on a website for whoever wished to respond. The sample was composed of 3,227 nurses from various health institutions in Portugal. From the results obtained it was observed that on average each nurse undergoes 11 aggression conducts in their main place of work. The types of aggression suffered with greater intensity by the victims are communication blockage and being discredited at work. The predominant types of mobbing are the horizontal and the descending type. Nurses suspected the following motivations for those who had perpetrated mobbing against them: envy or jealous, not yielding or having been influenced by blackmail, not being subservient and being innovative, or entrepreneurial in the new work methods or perspectives. Almost half of the victims claim to have had health problems as a result of having suffered mobbing in their workplace.

[Mobbing--special reference to the nursing profession].

PubMed

Milutinović, Dragana; Prokes, Bela; Gavrilov-Jerkovié, Vesna; Filipović, Danka

2009-01-01

Heinz Leymann defined this phenomenon as a hostile and unethical communication. In his definition Leymann points out that the distinction between "conflict" and "mobbing" does not focus on what is done or how it is done, but rather on the frequency and duration of whatever is done. The exposure to the strain of mobbing begins to result in psychiatrically or psychosomatically pathological conditions due to the accumulation of negative emotions. Leyman emphasizes four main factors which cause harrasment in the workplace: lack of clarity of goals in work, inadequate management, victim's social status and low moral standards in the work environment. The epidemiological data in the European Union, indicate great national differences relative to the percentage of those subjected to mobbing, with increasing exposure rates in all professions, the highest being found in education (14%) and health services. Nurses are considered a professional group at a rather high risk for trauma caused by harrasment in the workplace. "Horizontal violence" is a widely used term regarding mobbing aclions in nursing profession even though vertical violence is present both in this profession and all other health services. Horizontal violence is implied due to the traditional assumption that nurses have a subordinate role compared to doctors, which often brings them into conflict with their peers. Mobbing may be prevented by systematic primary prevention, information, education, and training in communication skills. As a result, we could expect to get a higher quality of nursing care and healthier nurses.

[Work-related stress and mobbing: case series and gender differences].

PubMed

Tonini, Stefano; Lanfranco, Andrea; Costa, Maria Cristina; Lumelli, Diego; Giorgi, Ines; Mazzacane, Fulvio; Scafa, Fabrizio; Candura, Stefano M

2011-01-01

The attention of international agencies and scientific community on mobbing (bullying) and work-related stress is increasing. However, research on gender differences and etiologic agents is still limited. This study describes the gender differences found in victims of mobbing and work-related stress in an Italian case series. Between 2001 and 2009, at the Occupational Medicine Unit of our Institution we examined 345 outpatients (197 women and 148 men) for suspected psychopathological work-related problems. After interdisciplinary diagnostic evaluation, the diagnosis of "mobbing syndrome" was formulated, according to international criteria (ICD-I0 and DSM-IV), in a minority of cases: 35 subjects. In the other workers, we found pre-existing psychiatric conditions (not related to work), or altered relationships dynamics with the colleagues. Significant gender differences emerged among people with "mobbing syndrome": there was a high prevalence of women (65%), with medium to high level of education; the most affected age group was between 34 and 45 years; several occupations were involved, with a clear preponderance of office workers. Women are mostly harassed for personal aspects related to emotional and relational factors; men for the content of their work. The knowledge of the phenomenon is an essential prerogative to contrast mobbing; this can be realized, at a preventive level, only through effective information and training for workers and employers, who have the legal obligation to preserve the integrity of the mental and physical status of their employees during the work.

Versatile Optical Bench for Teaching, Development, and Testing of Electron and Ion Optical Systems

ERIC Educational Resources Information Center

Bhiday, M. R.; And Others

1977-01-01

Describes a versatile apparatus for demonstrating the imaging properties of various types of electrostatic lenses. The apparatus can be used to study the focusing properties of different types of electrostatic electron or ion lenses or their combinations. (MLH)

Visualization of fluid turbulence and acoustic cavitation during phacoemulsification.

PubMed

Tognetto, Daniele; Sanguinetti, Giorgia; Sirotti, Paolo; Brezar, Edoardo; Ravalico, Giuseppe

2005-02-01

To describe a technique for visualizing fluid turbulence and cavitational energy created by ultrasonic phaco tips. University Eye Clinic of Trieste, Trieste, Italy. Generation of cavitational energy by the phaco tip was visualized using an optical test bench comprising several components. The technique uses a telescope system to expand a laser light source into a coherent, collimated beam of light with a diameter of approximately 50.0 mm. The expanded laser beam shines on the test tube containing the tip activated in a medium of water or ophthalmic viscosurgical device (OVD). Two precision optical collimators complete the optical test bench and form the system used to focus data onto a charge-coupled device television camera connected to a recorder. Images of irrigation, irrigation combined with aspiration, irrigation/aspiration, and phacosonication were obtained with the tip immersed in a tube containing water or OVD. Optical image processing enabled acoustic cavitation to be visualized during phacosonication. The system is a possible means of evaluating a single phaco apparatus power setting and comparing phaco machines and techniques.

Laser figuring for the generation of analog micro-optics and kineform surfaces

NASA Technical Reports Server (NTRS)

Gratrix, Edward J.

1993-01-01

To date, there have been many techniques used to generate micro-optic structures in glass or other materials. Using methods common to the lithographic industry, the manufacturing technique known as 'binary optics,' has demonstrated the use of diffractive optics in a variety of micro-optic applications. It is well established that diffractive structures have limited capability when applied in a design more suited for a refractive element. For applications that demand fast, highly efficient, broadband designs, we have developed a technique which uses laser figuring to generate the refractive micro-optical surface. This paper describes the technique used to fabricate refractive micro-optics. Recent results of micro-optics in CdZnTe focal planes are shown.

Interchip link system using an optical wiring method.

PubMed

Cho, In-Kui; Ryu, Jin-Hwa; Jeong, Myung-Yung

2008-08-15

A chip-scale optical link system is presented with a transmitter/receiver and optical wire link. The interchip link system consists of a metal optical bench, a printed circuit board module, a driver/receiver integrated circuit, a vertical cavity surface-emitting laser/photodiode array, and an optical wire link composed of plastic optical fibers (POFs). We have developed a downsized POF and an optical wiring method that allows on-site installation with a simple annealing as optical wiring technologies for achieving high-density optical interchip interconnection within such devices. Successful data transfer measurements are presented.

Mobbing and sitting tight at the nest as methods of avoiding brood parasitism.

PubMed

Rands, Sean A

2012-04-06

The arms race between brood parasites and their hosts has led to many different host behaviours for avoiding parasitism. Some of these behaviours are social, and require the presence of conspecifics to work effectively: in response to alarm calls, some species engage in mobbing behaviour where neighbours join nest tenants in attacking and repelling an invading brood parasite. There are risks involved for the neighbours, but it has been demonstrated that social mobbing allows individuals to learn about the presence of brood parasites in the environment, suggesting that social learning is occurring. Here, I consider whether using social signals to alert naive individuals to the presence of brood parasites is a suitable strategy, compared with sitting tight on the nest in response to the signal (which should reduce the chances of being parasitized). I also compare the efficiency of these strategies with the case where individuals fail to change behaviour in response a brood parasite. Using an individual-based simulation model, I demonstrate that both mobbing and sitting tight are effective strategies in response to a signal, and that mobbing is more effective when the chances of being parasitized increase. These results are discussed and compared with known host-brood parasite relationships.

Workplace physical violence, verbal violence, and mobbing experienced by nurses at a university hospital.

PubMed

Aksakal, Fatma Nur Baran; Karaşahin, Emine Füsun; Dikmen, Asiye Uğraş; Avci, Emine; Ozkan, Seçil

2015-01-01

The aim of this study was to determine the frequency of and risk factors for physical violence, verbal violence, and mobbing experienced by nurses in a university hospital. This was a cross-sectional study conducted at Gazi University Medical Faculty Hospital. A questionnaire form recommended by the WHO and the International Labor Organization was administered through face-to-face interviews to determine the violence experienced in the past 12 months by nurses. The prevalence of physical violence, verbal violence, and mobbing was 13.9%, 41.8%, and 17.1%, respectively. Working more than 40 h per week increased the risk of physical violence by 1.86 times. The majority of nurses who experienced verbal violence and mobbing were significantly more willing to change their work, their institution, and their profession if given the opportunity. Fewer than one-fourth of the victims indicated they reported any incident. We knew that the prevalence of physical violence, verbal violence, and mobbing were high among nurses and that incidents were underreported, and the study corroborated this information. What this study adds to the topic is that long working hours increased the prevalence of physical violence and was defined as an important contributory factor.

Medico-legal implications of mobbing. A false accusation of psychological harassment at the workplace.

PubMed

Jarreta, Begoña Martínez; García-Campayo, Javier; Gascón, Santiago; Bolea, Miguel

2004-12-02

Mobbing, or psychological harassment at the workplace, is usually defined as a situation in which a person or a group of people engage in extreme psychological violence against another person. In Spain, the number of reports for mobbing has increased extraordinarily in the last years. The reports are increasing dramatically not only before the Labour Courts, but also before the Civil Courts, with claims for damages, and before the Penal Court for offences causing physical or moral injury, etc., since at the present time this figure is not typified as an offence in the Spanish Penal Code. The high degree of complexity of this situation has given rise to frequent misuse of the term and to a number of false accusations of mobbing. A recent European Parliament Resolution on harassment at the workplace addressed the devastating consequences of false accusations. In this paper we present a case in which the "false" victim was mentally ill (paranoia) but succeed in generating an extreme dangerous environment of great harassment against the "false" assailants that were "falsely" accused of mobbing. Forensic diagnosis of the psychiatric disorder suffered by the "false" victim was essential to clarify the issue at the Penal Court.

[Socioprofessional variables involved in mobbing in nursing].

PubMed

Fornés-Vives, Joana; Martínez-Abascal Martínez, M Angeles; García-Banda García, Gloria

2008-01-01

To determine the type, frequency and cause of the most frequent hostile behaviors in a sample of nurses in the Balearic Islands and the socio-professional variables involved. We performed a cross-sectional descriptive study. The sample was composed of 464 members of the association of nurses of the Balearic Islands (392 women and 49 men). Age ranged from 25 to 65 years (mean: 35.11; SD: 9.62); 368 worked in public institutions and 71 in private centers. The instrument used was the Psychological Mobbing Questionnaire. A total of 17.2% of the nurses believed they had experienced mobbing at work (men: 22.4%; women: 14.5%). Significant differences were found according to age, but not according to institution. The most frequent hostile behavior was related to distortion of information, criticism of the purported victim, and lack of professional consideration. The perpetrators of mobbing were mainly, and very significantly, the bosses. According to these results, one in five nurses in the Balearic Islands has experienced mobbing in the workplace. However, because of the low response rate, caution should be exercised when generalizing these results. Nevertheless, health institutions should bear these findings in mind to ensure standards of behavior that do not jeopardize workers' health and dignity.

[Significance of mobbing in Italian law].

PubMed

Bollani, A

2008-01-01

The author analyzes the juridical profile that the phenomenon of mobbing assumes within the Italian legal system, emphasizing that the English term of current usage does not designate any specific legal entity as such but simply refers, in summary fashion, to deeds and behaviours that need to be qualified according to the law in vigour. The normative frame of reference for mobbing is found in article 2087 of the Civil code, which states, as an open, teleologically oriented norm, the employer's obligation to safeguard the moral person of the employee; hence the onus is on the interpreter, essentially, to evaluate if there has been, in actual fact, a contravention of this safeguarded legal right. The author then discusses profiles that intersect with mobbing (or behaviours perceived as such) drawing on other cases regulated by the law such as the safeguarding of professionality (art. 2103 of the Civil code), and underlines that often mobbing ends by being construed as a mere accompaniment to, if not duplication of, other typical cases. Finally, the author discusses aspects of the judicial process related to the allegation and proof of the facts constituting the offence, and to the damage, in its various non patrimonial components.

The Effects of the A Matter of Balance Program on Falls and Physical Risk of Falls, Tampa, Florida, 2013.

PubMed

Chen, Tuo-Yu; Edwards, Jerri D; Janke, Megan C

2015-09-24

This study investigated the effects of the A Matter of Balance (MOB) program on falls and physical risk factors of falling among community-dwelling older adults living in Tampa, Florida, in 2013. A total of 110 adults (52 MOB, 58 comparison) were enrolled in this prospective cohort study. Data on falls, physical risk of falling, and other known risk factors of falling were collected at baseline and at the end of the program. Multivariate analysis of covariance with repeated measures and logistic regressions were used to investigate the effects of this program. Participants in the MOB group were less likely to have had a fall and had significant improvements in their physical risk of falling compared with adults in the comparison group. No significant effects of the MOB program on recurrent falls or the number of falls reported were found. This study contributes to our understanding of the MOB program and its effectiveness in reducing falls and the physical risk of falling among older adults. The findings support extended use of this program to reduce falls and physical risk of falling among older adults.

Biotic Interactions in Microbial Communities as Modulators of Biogeochemical Processes: Methanotrophy as a Model System

PubMed Central

Ho, Adrian; Angel, Roey; Veraart, Annelies J.; Daebeler, Anne; Jia, Zhongjun; Kim, Sang Yoon; Kerckhof, Frederiek-Maarten; Boon, Nico; Bodelier, Paul L. E.

2016-01-01

Microbial interaction is an integral component of microbial ecology studies, yet the role, extent, and relevance of microbial interaction in community functioning remains unclear, particularly in the context of global biogeochemical cycles. While many studies have shed light on the physico-chemical cues affecting specific processes, (micro)biotic controls and interactions potentially steering microbial communities leading to altered functioning are less known. Yet, recent accumulating evidence suggests that the concerted actions of a community can be significantly different from the combined effects of individual microorganisms, giving rise to emergent properties. Here, we exemplify the importance of microbial interaction for ecosystem processes by analysis of a reasonably well-understood microbial guild, namely, aerobic methane-oxidizing bacteria (MOB). We reviewed the literature which provided compelling evidence for the relevance of microbial interaction in modulating methane oxidation. Support for microbial associations within methane-fed communities is sought by a re-analysis of literature data derived from stable isotope probing studies of various complex environmental settings. Putative positive interactions between active MOB and other microbes were assessed by a correlation network-based analysis with datasets covering diverse environments where closely interacting members of a consortium can potentially alter the methane oxidation activity. Although, methanotrophy is used as a model system, the fundamentals of our postulations may be applicable to other microbial guilds mediating other biogeochemical processes. PMID:27602021

Field-Scale Stable-Isotope Probing of Active Methanotrophs in a Landfill-Cover Soil

NASA Astrophysics Data System (ADS)

Schroth, M. H.; Henneberger, R.; Chiri, E.

2012-12-01

The greenhouse gas methane (CH4) is an important contributor to global climate change. While its atmospheric concentration is increasing, a large portion of produced CH4 never reaches the atmosphere, but is consumed by aerobic methane-oxidizing bacteria (MOB). The latter are ubiquitous in soils and utilize CH4 as sole source of energy and carbon. Among other methods, MOB may be differentiated based on characteristic phospholipid fatty acids (PLFA). Stable-isotope probing (SIP) on PLFA has been widely applied to identify active members of MOB communities in laboratory incubation studies, but results are often difficult to extrapolate to the field. Thus, novel field-scale approaches are needed to link activity and identity of MOB in their natural environment. We present results of field experiments in which we combined PLFA-SIP with gas push-pull tests (GPPTs) to label active MOB at the field-scale while simultaneously quantifying CH4 oxidation activity. During a SIP-GPPT, a mixture of reactive (here 13CH4, O2) and non-reactive tracer gases (e.g., Ar, Ne, He) is injected into the soil at a location of interest. Thereafter, gas flow is reversed and the gas mixture diluted with soil air is extracted from the same location and sampled periodically. Rate constants for CH4 oxidation can be calculated by analyzing breakthrough curves of 13CH4 and a suitable non-reactive tracer gas. SIP-GPPTs were performed in a landfill-cover soil, and feasibility of this novel approach was tested at several locations along a gradient of MOB activity and soil temperature. Soil samples were collected before and after SIP-GPPTs, total PLFA were extracted, and incorporation of 13C in the polar lipid fraction was analyzed. Potential CH4 oxidation rates derived from SIP-GPPTs were similar to those derived from regular GPPTs (using unlabeled CH4) performed at the same locations prior to SIP-GPPTs, indicating that application of 13CH4 did not adversely affect bacterial CH4 oxidation rates. Rates calculated for different locations ranged from 0.2 to 52.8 mmol CH4 (L soil air)-1 d-1. PLFA analyses showed high levels of 13C incorporation into different 14C and 16C fatty acids (FA), typically found in Type I MOB, and 18C FAs, typical for Type II MOB. The amount of 13C incorporated into biomass clearly increased with increasing activity, and δ13C values of >1500 ‰ were observed for selected FAs at high-activity locations. In addition, the range of labeled FAs also changed with activity, and no Type II MOB specific FAs were labeled at the low-activity location. The novel SIP-GPPT approach was shown to be a valuable field-scale method to detect and identify active MOB over a wide range of activities.

Wafer-scale micro-optics fabrication

NASA Astrophysics Data System (ADS)

Voelkel, Reinhard

2012-07-01

Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

Mobbing (bullying at work) in Italy: characteristics of successful court cases

PubMed Central

Acquadro Maran, Daniela; Bernardelli, Silvia; Varetto, Antonella

2018-01-01

Abstract: Background: Mobbing (bullying at work) refers to a form of psychological harassment that occurs in the workplace, in which the victim must be systematically and continuously persecuted for a long period of time. The aim of this work is to analyze the court judgments related to mobbing. Methods: The data, collected from a website that included judgments from an Italian court, were analyzed according to the literature, identifying the type of victims, consequences, methods of harassment, type of mobbers, and compensation decided by the court. Results: A total of 35 court sentences were analyzed. The findings showed that the duration of the mobbing campaign was on average 1.5 years and that the frequency of harassment was every day in most cases. In the majority of cases (17, 48.6%) the mobbing occurred in a private company. The gender of the victims who reported the mobbing experience was predominantly female (19, 54.3%), and on average, the victims were 44.54 years of age. The victims were classified as captives (12, 34.3%), scapegoats (8, 22.9%), ambitious (8, 22.9%), passives (5, 14.3%) and hypochondriacs (2, 5.7%). The mobbers were predominantly men (25, 71.4%) and on average 53.20 years of age. They were classified as casual (12, 34.3%), sadists (11, 31.4%), instigators (8, 22.9%) and choleric (4, 11.4%). The witnesses were described in the majority of cases as active, while the asymmetry of power was vertical. On average, the victims suffered 4.9 types of harassment, and the most cited consequences were anxiety disorder and physical symptoms. The motives for beginning the mobbing campaign were principally related to difficulties in relationships. The compensation imposed by the court ranged from less than 20,000 to more than 70,000 euros. Conclusions: The sentences analyzed showed that for different types of victims, there are behaviors, motives and consequences that are linked to different types of perpetrators. PMID:29187725

Defective monocyte oxidative burst predicts infection in alcoholic hepatitis and is associated with reduced expression of NADPH oxidase.

PubMed

Vergis, Nikhil; Khamri, Wafa; Beale, Kylie; Sadiq, Fouzia; Aletrari, Mina O; Moore, Celia; Atkinson, Stephen R; Bernsmeier, Christine; Possamai, Lucia A; Petts, Gemma; Ryan, Jennifer M; Abeles, Robin D; James, Sarah; Foxton, Matthew; Hogan, Brian; Foster, Graham R; O'Brien, Alastair J; Ma, Yun; Shawcross, Debbie L; Wendon, Julia A; Antoniades, Charalambos G; Thursz, Mark R

2017-03-01

In order to explain the increased susceptibility to serious infection in alcoholic hepatitis, we evaluated monocyte phagocytosis, aberrations of associated signalling pathways and their reversibility, and whether phagocytic defects could predict subsequent infection. Monocytes were identified from blood samples of 42 patients with severe alcoholic hepatitis using monoclonal antibody to CD14. Phagocytosis and monocyte oxidative burst (MOB) were measured ex vivo using flow cytometry, luminometry and bacterial killing assays. Defects were related to the subsequent development of infection. Intracellular signalling pathways were investigated using western blotting and PCR. Interferon-γ (IFN-γ) was evaluated for its therapeutic potential in reversing phagocytic defects. Paired longitudinal samples were used to evaluate the effect of in vivo prednisolone therapy. MOB, production of superoxide and bacterial killing in response to Escherichia coli were markedly impaired in patients with alcoholic hepatitis. Pretreatment MOB predicted development of infection within two weeks with sensitivity and specificity that were superior to available clinical markers. Accordingly, defective MOB was associated with death at 28 and 90 days. Expression of the gp91 phox subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was reduced in patients with alcoholic hepatitis demonstrating defective MOB. Monocytes were refractory to IFN-γ stimulation and showed high levels of a negative regulator of cytokine signalling, suppressor of cytokine signalling-1. MOB was unaffected by 7 days in vivo prednisolone therapy. Monocyte oxidative burst and bacterial killing is impaired in alcoholic hepatitis while bacterial uptake by phagocytosis is preserved. Defective MOB is associated with reduced expression of NADPH oxidase in these patients and predicts the development of infection and death. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Flash Mob Science - Increasing Seismic Hazard Awareness and Preparedness in Oregon

NASA Astrophysics Data System (ADS)

Hoffman, J. S.; Lownsbery, D. S.

2015-12-01

Living in a region of imminent threat of a magnitude-9.0 (M­­­w ≈ ­9) earthquake is a daily reality for the millions of people predicted to be directly affected by a full rupture of the Cascadia Subduction Zone (CSZ), a fault line extending for hundreds of miles off the western coast of North America. Many coastal residents and visitors will also be affected by the tsunami caused by the rupture. How can the scientific community effectively communicate with those who are unaware of the threat and unprepared to respond? We are studying the effects of a novel approach to science outreach we have called Flash Mob Science. You have probably seen examples of flash mobs staging dynamic musical and dance routines to unsuspecting audiences. Similarly, Flash Mob Science takes the challenging (and often avoided) topic of earthquake and tsunami awareness and preparedness to unsuspecting audiences. However, Flash Mob Science seeks to move beyond having an audience of observers by engaging others as participants who enact important roles in an unfolding drama. We simulate the effects of seismic and tsunami events (e.g., prolonged surface shaking, falling debris, repeated tsunami surges) and model best practices in response (e.g., "Drop, Cover, Hold On" and moving quickly to high ground). True to the general flash mob model, when the Cascadia event inevitably does occur, it will come suddenly, and everyone affected will unavoidably be involved as actors in a real-life drama of immense scale. We seek to embed the learning of basic understandings and practices for an actual Cascadia event in a very small-scale, memorable, and sometimes even humorous, dramatization. We present here the lessons we have learned in the background, planning, and implementation of Flash Mob Science. We highlight the successes, limitations, and preliminary results evaluating the effectiveness of this outreach in developing learners' understandings and preparedness in an Oregon community affected by the CSZ.

Mobbing (bullying at work) in Italy: characteristics of successful court cases.

PubMed

Acquadro Maran, Daniela; Bernardelli, Silvia; Varetto, Antonella

2018-01-01

Mobbing (bullying at work) refers to a form of psychological harassment that occurs in the workplace, in which the victim must be systematically and continuously persecuted for a long period of time. The aim of this work is to analyze the court judgments related to mobbing. The data, collected from a website that included judgments from an Italian court, were analyzed according to the literature, identifying the type of victims, consequences, methods of harassment, type of mobbers, and compensation decided by the court. A total of 35 court sentences were analyzed. The findings showed that the duration of the mobbing campaign was on average 1.5 years and that the frequency of harassment was every day in most cases. In the majority of cases (17, 48.6%) the mobbing occurred in a private company. The gender of the victims who reported the mobbing experience was predominantly female (19, 54.3%), and on average, the victims were 44.54 years of age. The victims were classified as captives (12, 34.3%), scapegoats (8, 22.9%), ambitious (8, 22.9%), passives (5, 14.3%) and hypochondriacs (2, 5.7%). The mobbers were predominantly men (25, 71.4%) and on average 53.20 years of age. They were classified as casual (12, 34.3%), sadists (11, 31.4%), instigators (8, 22.9%) and choleric (4, 11.4%). The witnesses were described in the majority of cases as active, while the asymmetry of power was vertical. On average, the victims suffered 4.9 types of harassment, and the most cited consequences were anxiety disorder and physical symptoms. The motives for beginning the mobbing campaign were principally related to difficulties in relationships. The compensation imposed by the court ranged from less than 20,000 to more than 70,000 euros. The sentences analyzed showed that for different types of victims, there are behaviors, motives and consequences that are linked to different types of perpetrators.

Organization of the main olfactory bulbs of some mammals: musk shrews, moles, hedgehogs, tree shrews, bats, mice, and rats.

PubMed

Kosaka, Katsuko; Kosaka, Toshio

2004-04-19

We immunohistochemically examined the organization of the main olfactory bulbs (MOBs) in seven mammalian species, including moles, hedgehogs, tree shrews, bats, and mice as well as laboratory musk shrews and rats. We focused our investigation on two points: 1) whether nidi, particular spheroidal synaptic regions subjacent to glomeruli, which we previously reported for the laboratory musk shrew MOBs, are also present in other animals and 2) whether the compartmental organization of glomeruli and two types of periglomerular cells we proposed for the rat MOBs are general in other animals. The general laminar pattern was similar among these seven species, but discrete nidi and the nidal layer were recognized only in two insectivores, namely, the mole and laboratory musk shrew. Olfactory marker protein-immunoreactive (OMP-IR) axons extended beyond the limits of the glomerular layer (GL) into the superficial region of the external plexiform layer (EPL) or the nidal layer in the laboratory musk shrew, mole, hedgehog, and tree shrew but not in bat, mouse, and rat. We observed, in nidi and the nidal layer in the mole and laboratory musk shrew MOBs, only a few OMP-IR axons. In the hedgehog, another insectivore, OMP-IR processes extending from the glomeruli were scattered and intermingled with calbindin D28k-IR cells at the border between the GL and the EPL. In the superficial region of the EPL of the tree shrew MOBs, there were a small number of tiny glomerulus-like spheroidal structures where OMP-IR axons protruding from glomeruli were intermingled with dendritic branches of surrounding calbindin D28k-IR cells. Furthermore, we recognized the compartmental organization of glomeruli and two types of periglomerular cells in the MOBs of all of the mammals we examined. These structural features are therefore considered to be common and important organizational principles of the MOBs. Copyright 2004 Wiley-Liss, Inc.

Olfactory Bulb Deep Short-Axon Cells Mediate Widespread Inhibition of Tufted Cell Apical Dendrites.

PubMed

Burton, Shawn D; LaRocca, Greg; Liu, Annie; Cheetham, Claire E J; Urban, Nathaniel N

2017-02-01

In the main olfactory bulb (MOB), the first station of sensory processing in the olfactory system, GABAergic interneuron signaling shapes principal neuron activity to regulate olfaction. However, a lack of known selective markers for MOB interneurons has strongly impeded cell-type-selective investigation of interneuron function. Here, we identify the first selective marker of glomerular layer-projecting deep short-axon cells (GL-dSACs) and investigate systematically the structure, abundance, intrinsic physiology, feedforward sensory input, neuromodulation, synaptic output, and functional role of GL-dSACs in the mouse MOB circuit. GL-dSACs are located in the internal plexiform layer, where they integrate centrifugal cholinergic input with highly convergent feedforward sensory input. GL-dSAC axons arborize extensively across the glomerular layer to provide highly divergent yet selective output onto interneurons and principal tufted cells. GL-dSACs are thus capable of shifting the balance of principal tufted versus mitral cell activity across large expanses of the MOB in response to diverse sensory and top-down neuromodulatory input. The identification of cell-type-selective molecular markers has fostered tremendous insight into how distinct interneurons shape sensory processing and behavior. In the main olfactory bulb (MOB), inhibitory circuits regulate the activity of principal cells precisely to drive olfactory-guided behavior. However, selective markers for MOB interneurons remain largely unknown, limiting mechanistic understanding of olfaction. Here, we identify the first selective marker of a novel population of deep short-axon cell interneurons with superficial axonal projections to the sensory input layer of the MOB. Using this marker, together with immunohistochemistry, acute slice electrophysiology, and optogenetic circuit mapping, we reveal that this novel interneuron population integrates centrifugal cholinergic input with broadly tuned feedforward sensory input to modulate principal cell activity selectively. Copyright © 2017 the authors 0270-6474/17/371117-22$15.00/0.

Bench Test of the Vibration Compensation Interferometer for EAST Tokamak

NASA Astrophysics Data System (ADS)

Li, Gongshun; Yang, Yao; Liu, Haiqing; Jie, Yinxian; Zou, Zhiyong; Wang, Zhengxing; Zeng, Long; Wei, Xuechao; Li, Weiming; Lan, Ting; Zhu, Xiang; Liu, Yukai; Gao, Xiang

2016-02-01

A visible laser-based vibration compensation interferometer has recently been designed for the EAST tokamak and the bench test has been finished. The system was optimized for its installation on EAST. The value of the final optical power before the detectors without plasma has been calculated from the component bench test result, which is quite close to the measured value. A nanometer level displacement (of the order of the laser's wavelength) has been clearly measured by a modulation of piezoelectric ceramic unit, proving the system's capability. supported by the National Magnetic Confinement Fusion Program of China (Nos. 2014GB106002, 2014GB106003, 2014GB106004) and National Natural Science Foundation of China (Nos. 11105184, 11375237, 11505238)

Development of optical tools for the characterization of selective solar absorber at elevated temperature

NASA Astrophysics Data System (ADS)

Giraud, Philemon; Braillon, Julien; Delord, Christine; Raccurt, Olivier

2016-05-01

Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The objective is to develop new optical equipment for characterization of this solar absorber in condition of use that is to say in air and at elevated temperature. In this paper we present two new optical test benches developed for optical characterization of solar absorbers in condition of use up to 800°C. The first equipment is an integrated sphere with heated sample holder which measures the hemispherical reflectance between 280 and 2500 nm to calculate the solar absorbance at high temperature. The second optical test bench measures the emittance of samples up to 1000°C in the range of 1.25 to 28.57 µm. Results of high temperature measurements on a series of metallic absorbers with selective coating and refractory material for high thermal receiver are presented.

[Fitness, disability and mobbing].

PubMed

Magnavita, N; Bosco, M G; Ranalletta, D; Salerno, S

2006-01-01

Workers with handicap or psychological impairment are frequently submitted to mobbing. If causative factors of psychological disorders are not recognized, the physician charged of medical surveillance of workers may himself become a prosecutor and enhance the mobbing actions to the extent that the mobbed worker is discharged. In order to avoid this undue effect, the physician should strictly adhere to the body of legislation and to good occupational medicine practices. Health surveillance for occupationally exposed groups of workers is required under specific health and safety legislation. Workers unexposed to hazard in the workplace cannot be included in health surveillance programme, and declaring these workers unfit for their job is a patent violation of Workers' Statute Law. Psychological disorders should be carefully evaluated in order to clarify their relationship with work. The case of a worker affected with schizophrenia, already reported in the literature, is here re-analysed in order to emphasize these concepts.

Methane biofiltration using autoclaved aerated concrete as the carrier material.

PubMed

Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Boeckx, Pascal; Ho, Adrian; Boon, Nico

2015-09-01

The methane removal capacity of mixed methane-oxidizing bacteria (MOB) culture in a biofilter setup using autoclaved aerated concrete (AAC) as a highly porous carrier material was tested. Batch experiment was performed to optimize MOB immobilization on AAC specimens where optimum methane removal was obtained when calcium chloride was not added during bacterial inoculation step and 10-mm-thick AAC specimens were used. The immobilized MOB could remove methane at low concentration (~1000 ppmv) in a biofilter setup for 127 days at average removal efficiency (RE) of 28.7 %. Unlike a plug flow reactor, increasing the total volume of the filter by adding a biofilter in series did not result in higher total RE. MOB also exhibited a higher abundance at the bottom of the filter, in proximity with the methane gas inlet where a high methane concentration was found. Overall, an efficient methane biofilter performance could be obtained using AAC as the carrier material.

Nano-stepper-driven optical shutter for applications in free-space micro-optics

NASA Astrophysics Data System (ADS)

Zawadzka, Justyna; Li, Lijie; Unamuno, Anartz; Uttamchandani, Deepak G.

2002-09-01

In this paper we report a simple design of a micro-optical shutter/attenuator. The standard MUMPS process was used to fabricate the device. A vertically erected, gold-coated, 200x300 mm side length micro-mirror was precisely placed between the end faces of two closely spaced optical fibers. The position of the micro-mirror with respect to the optical fiber end face was controlled by a nano-stepping motor array. Optical and mechanical tests were performed on the device. A 1.55 mm laser beam was sent along the optical fiber. When the micro-mirror was removed from the front of the fiber, the coupling efficiency between two fibers was -10 dBm. Once the micro-mirror was placed in the optical path the coupling efficiency dropped to -51.5 dBm. The best attenuation was obtained when the micro-mirror blocked the whole cross-section of the laser beam diameter. It is evident that the device can operate as a high precision fiber optic attenuator or shutter.

Inverse correlation between morning plasma cortisol levels and MMPI psychasthenia and depression scale scores in victims of mobbing with adjustment disorders.

PubMed

Rocco, Antonio; Martocchia, Antonio; Frugoni, Patrizia; Baldini, Rossella; Sani, Gabriele; Di Simone Di Giuseppe, Barbara; Vairano, Andrea; Girardi, Paolo; Monaco, Edoardo; Tatarelli, Roberto; Falaschi, Paolo

2007-10-01

Evidence in the literature suggests stress-related changes of hypothalamus-pituitary-adrenal (HPA) axis in mobbing. We investigated the association between HPA activity and psychological profiles in mobbing, using a multidisciplinary approach. Forty-eight victims of mobbing were evaluated by a working group of the Departments of Occupational Medicine, Psychiatry and Internal Medicine. After an informed consent, a detailed occupational history, a psychiatric interview with Minnesota Multiphasic Personality Inventory 2 (MMPI-2) administration and a blood sample (8:00 AM) for the determination of basal adrenocorticotropin (ACTH), cortisol and dehydroepiandrosterone sulphate (DHEAS) plasma levels were collected. Twenty-six patients received an overnight dexamethasone (dex) test. Mean ACTH, cortisol and DHEAS levels were within normal ranges. The dex-test response was normal, with a significant hormone suppression (ACTH p<0.001, cortisol p<0.001, DHEAS p<0.001). The correlations between basal hormones and the psychometric scales of MMPI-2 revealed that cortisol was significantly and negatively related to Psychasthenia (Pt, p=0.003) and Depression (D, p=0.006), while DHEAS showed a significant negative correlation to Hysteria (Hy, p=0.008). Basal ACTH levels were not significantly related to psychometric scales. A significant inverse correlation between morning plasma cortisol levels and psychometric parameters in victims of mobbing with adjustment disorders was observed. A larger group of patients is necessary to identify and validate a cut-off cortisol level that may become an innovative biological parameter for the diagnosis and follow-up in victims of mobbing.

Calibration of the MCAO Canopus Bench

NASA Astrophysics Data System (ADS)

Garcia-Rissmann, Aurea; Rigaut, François; Bec, Matthieu; Boccas, Maxime; Galvez, Ramon; Gausachs, Gaston; Gratadour, Damien; Neichel, Benoit

The final phase of implementation of all optical components, as well as their integration and tests on the Canopus MCAO bench is currently underway. We present here a detailed description of the LGS and NGS WFS calibration sequences implemented through MYST (MCAO Yorick Smart Tool), a yorick+python+glade software package developed in-house which allows multiple users to control and monitor the bench remotely over the network using EPICS commands. A fine tuning of the optical setup and a better understanding of the flexure/temperature dependencies is being carried out and will allow us to build the many look-up tables to be eventually used by the system (e.g. telescope primary and secondary mirrors). Preliminary work on non-common path aberrations to account for the static aberrations in the central 60 arcsec science field of view (FoV) has been done iteratively using a science focal plane wavefront sensor and has shown good results both in individual directions as well as simultaneously over the entire FoV, the latter using the tomographic approach (presented in another paper in this conference).

Micro benchtop optics by bulk silicon micromachining

DOEpatents

Lee, Abraham P.; Pocha, Michael D.; McConaghy, Charles F.; Deri, Robert J.

2000-01-01

Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

[The relationship between mobbing and depression syndrome in the female working population of service industry: the problem statement and the prevention strategies in Sicilian environment].

PubMed

Romano, C; De Giovanni, L; Santoro, P E; Spataro, M

2007-01-01

The concept of "work" and the social interactions in the workplace contribute to develop the working satisfaction and the social and personal identity of the adult. The aim of the survey is that of checking up on the presence of a statistically significant relation between The Depression Syndrome and The Mobbing Phenomenon. It is necessary to understand and value if and how some of the employer's behaviours could have a heavy influence on the worker's psychophysical condition, up to causing a state of anxiety and depression. It has been used the now famous "LIPT" (Leymann Inventory of Psychological Terror), elaborated by Leymann at the beginning of the 90's. It is a short anonymous questionnaire recognized all over Europe as a standard to confirm the Mobbing existence in organizational contexts. The current version of the questionnaire is called "LIPT EGE", a more suitable tool to check the seven parameters of the Mobbing determination, as well as the quantification of the consequent harm. Some scales for depressive symptoms evaluation have been added to the Mobbing questionnaire: The Self Rating Depression Scale (SDS) and The Depression Status Inventory (DSI) of Zung. The questionnaires are administered to 500 workers women in public and private corporation in Sicily, exactly in Siracusa and Catania provinces. 206 women aged 34-50 have answered the questionnaires. In addition to the age and the sex, the distinction variables of the examined people are the position in the firm, nationality, vocational qualification, and the yearly gross income. The research has begun in july and has continued on august 2006. Attention has been focused only on the administrative sectors. Through the chi2 test and the exact Fisher test, the dependence between the changeable presence of depression in the two questionnaires (Zung 1 and Zung 2) and every single variable of the questionnaire on the Mobbing has been pointed out. In particular, the results establish a connection between the presence of depression and systematic isolation, and depression and the changes in the working tasks. The survey has pointed out the working conditions that may lead to Mobbing situations and to psychological frustration; it follows that the Mobbing prevention is a key element if you want to better working life and avoid social emargination.

Micro optical fiber light source and sensor and method of fabrication thereof

DOEpatents

Kopelman, Raoul; Tan, Weihong; Shi, Zhong-You

1997-01-01

This invention relates generally to the development of and a method of fabricating a fiber optic micro-light source and sensor (50). An optical fiber micro-light source (50) is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors (22) in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material (60). This process allows significant control of the size of the micro light source (50). Furthermore, photo-chemically attaching an optically active material (60) enables the implementation of the micro-light source in a variety of sensor applications.

Micro optical fiber light source and sensor and method of fabrication thereof

DOEpatents

Kopelman, Raoul; Tan, Weihong; Shi, Zhong-You

1994-01-01

This invention relates generally to the development of and a method of fabricating a micro optical fiber light source. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications.

Micro optical fiber light source and sensor and method of fabrication thereof

DOEpatents

Kopelman, R.; Tan, W.; Shi, Z.Y.

1997-05-06

This invention relates generally to the development of and a method of fabricating a fiber optic micro-light source and sensor. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications. 10 figs.

Micro optical fiber light source and sensor and method of fabrication thereof

DOEpatents

Kopelman, R.; Tan, W.; Shi, Z.Y.

1994-11-01

This invention relates generally to the development of and a method of fabricating a micro optical fiber light source. An optical fiber micro-light source is presented whose aperture is extremely small yet able to act as an intense light source. Light sources of this type have wide ranging applications, including use as micro-sensors in NSOM. Micro-sensor light sources have excellent detection limits as well as photo stability, reversibility, and millisecond response times. Furthermore, a method for manufacturing a micro optical fiber light source is provided. It involves the photo-chemical attachment of an optically active material onto the end surface of an optical fiber cable which has been pulled to form an end with an extremely narrow aperture. More specifically, photopolymerization has been applied as a means to photo-chemically attach an optically active material. This process allows significant control of the size of the micro light source. Furthermore, photo-chemically attaching an optically active material enables the implementation of the micro-light source in a variety of sensor applications. 4 figs.

Wafer-level micro-optics: trends in manufacturing, testing, packaging, and applications

NASA Astrophysics Data System (ADS)

Voelkel, Reinhard; Gong, Li; Rieck, Juergen; Zheng, Alan

2012-11-01

Micro-optics is an indispensable key enabling technology (KET) for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the last decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks (supercomputer, ROADM), bringing high-speed internet to our homes (FTTH). Even our modern smart phones contain a variety of micro-optical elements. For example, LED flashlight shaping elements, the secondary camera, and ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by semiconductor industry. Thousands of components are fabricated in parallel on a wafer. We report on the state of the art in wafer-based manufacturing, testing, packaging and present examples and applications for micro-optical components and systems.

EPE The Extreme Physics Explorer

NASA Technical Reports Server (NTRS)

Garcia, Michael; Elvis, Martin; Bookbinder, Jay; Brenneman, Laura; Bulbul, Esra; Nulsen, Paul; Patnaude, Dan; Smith, Randall; Bandler, Simon; Okajima, Takashi;

Duplex-imprinted nano well arrays for promising nanoparticle assembly

NASA Astrophysics Data System (ADS)

Li, Xiangping; Manz, Andreas

2018-02-01

A large area nano-duplex-imprint technique is presented in this contribution using natural cicada wings as stamps. The glassy wings of the cicada, which are abundant in nature, exhibit strikingly interesting nanopillar structures over their membrane. This technique, with excellent performance despite the nonplanar surface of the wings, combines both top-down and bottom-up nanofabrication techniques. It transitions micro-nanofabrication from a cleanroom environment to the bench. Two different materials, dicing tape with an acrylic layer and a UV optical adhesive, are used to make replications at the same time, thus achieving duplex imprinting. The promise of a large volume of commercial manufacturing of these nanostructure elements can be envisaged through this contribution to speeding up the fabrication process and achieving a higher throughput. The contact angle of the replicated nanowell arrays before and after oxygen plasma was measured. Gold nanoparticles (50 nm) were used to test how the nanoparticles behaved on the untreated and plasma-treated replica surface. The experiments show that promising nanoparticle self-assembly can be obtained.

Community structure of planktonic methane-oxidizing bacteria in a subtropical reservoir characterized by dominance of phylotype closely related to nitrite reducer

NASA Astrophysics Data System (ADS)

Kojima, Hisaya; Tokizawa, Riho; Kogure, Kouhei; Kobayashi, Yuki; Itoh, Masayuki; Shiah, Fuh-Kwo; Okuda, Noboru; Fukui, Manabu

2014-07-01

Methane-oxidizing bacteria (MOB) gain energy from the oxidation of methane and may play important roles in freshwater ecosystems. In this study, the community structure of planktonic MOB was investigated in a subtropical reservoir. Bacterial community structure was investigated through the analysis of the 16S rRNA gene. Three groups of phylogenetically distinct MOB were detected in the clone libraries of polymerase chain reaction products obtained with universal primers. The groups belonged to the class Gammaproteobacteria, the class Alphaproteobacteria, and the candidate phylum NC10. The last group, which consists of close relatives of the nitrite reducer `Candidatus Methylomirabilis oxyfera', was frequently detected in the clone libraries of deep-water environments. The presence of 3 groups of MOB in deep water was also shown by a cloning analysis of the pmoA gene encoding particulate methane monooxygenase. The dominance of `M. oxyfera'-like organisms in deep water was confirmed by catalyzed reporter deposition-fluorescence in situ hybridization, in which cells stained with a specific probe accounted for 16% of total microbial cells. This is the first study to demonstrate that close relatives of the nitrite reducer can be major component of planktonic MOB community which may affect carbon flow in aquatic ecosystems.

Mobbing and sitting tight at the nest as methods of avoiding brood parasitism

PubMed Central

Rands, Sean A.

2012-01-01

The arms race between brood parasites and their hosts has led to many different host behaviours for avoiding parasitism. Some of these behaviours are social, and require the presence of conspecifics to work effectively: in response to alarm calls, some species engage in mobbing behaviour where neighbours join nest tenants in attacking and repelling an invading brood parasite. There are risks involved for the neighbours, but it has been demonstrated that social mobbing allows individuals to learn about the presence of brood parasites in the environment, suggesting that social learning is occurring. Here, I consider whether using social signals to alert naive individuals to the presence of brood parasites is a suitable strategy, compared with sitting tight on the nest in response to the signal (which should reduce the chances of being parasitized). I also compare the efficiency of these strategies with the case where individuals fail to change behaviour in response a brood parasite. Using an individual-based simulation model, I demonstrate that both mobbing and sitting tight are effective strategies in response to a signal, and that mobbing is more effective when the chances of being parasitized increase. These results are discussed and compared with known host–brood parasite relationships. PMID:23565334

Perception of mobbing during the study: results of a national quantitative research among Slovenian midwifery students.

PubMed

Došler, Anita Jug; Skubic, Metka; Mivšek, Ana Polona

2014-09-01

Mobbing, defined as sustained harassment among workers, in particular towards subordinates, merits investigation. This study aims to investigate Slovenian midwifery students' (2nd and 3rd year students of midwifery at the Faculty for Health Studies Ljubljana; the single educational institution for midwives in Slovenia) perception of mobbing, since management of acceptable behavioural interrelationships in midwifery profession forms already during the study, through professional socialization. Descriptive and causal-nonexperimental method with questionnaire was used. Basic descriptive statistics and measures for calculating statistical significance were carried out with SPSS 20.0 software version. All necessary ethical measures were taken into the consideration during the study to protect participants. The re- sults revealed that several participants experienced mobbing during the study (82.3%); 58.8% of them during their practical training and 23.5% from midwifery teachers. Students are often anxious and nervous in face of clinical settings (60.8%) or before faculty commitments (exams, presentations etc.) (41.2%). A lot of them (40.4%) estimate that mobbing affected their health. They did not show effective strategies to solve relationship problems. According to the findings, everyone involved in midwifery education, but above all students, should be provided with more knowledge and skills on successful management of conflict situations.

[Mobbing: between personality traits and organizational-managerial characteristics of the occupational environment].

PubMed

Fenga, Concettina; Platania, Chiara Anna; Di Rosa, Antonio; Alibrandi, Angela; De Luca, Annamaria; Barresi, Gaetano; Di Nola, Carmelina; Cacciola, Anna

2012-01-01

INTRODUCTION. The relationship between stressful events in the workplace and their effect on health is the subject of numerous studies where the phenomenon of"Mobbing" has become of increasing interest in Social Psychiatry and Occupational Medicine. The aim of this study is to evaluate the relationship between mobbing, occupational stress and personality structure in a group of persons who consulted the "Work Adaptation Disorders Centre" at the Institute of Occupational Medicine between December 2008 and June 2010 for mobbing-related issues. Referring to Leymann Inventory of Psychological Terrorization (LIPT), H. Ege, Occupational Stress Indicator (OSI), Minnesota Multiphasic Personality Inventory 2 (MMPI-2), it has been possible to assess situations of harassment, the sources and the effects of work stress, as well as personality traits in the study group. The results showed that high levels of occupational stress and inadequate coping strategies can lead to depressive, hysterical and paranoid manifestations. Although the relationship between mobbing, occupational stress and personality traits still remains controversial, there is an association between perception of adverse behaviour and mental health, regardless of the subject's ability to cope with stressful life events. The data seem to confirm that the prevention of bullying must be implemented by the work organization and by handling interpersonal conflicts in the work context.

Micro-optics technology and sensor systems applications

NASA Technical Reports Server (NTRS)

Gal, George; Herman, B.; Anderson, W.; Whitney, R.; Morrow, H.

1993-01-01

The current generation of electro-optical sensors utilizing refractive and reflective optical elements require sophisticated, complex, and expensive designs. Advanced-technology-based electro-optical sensors of minimum size and weight require miniaturization of optical, electrical, and mechanical devices with an increasing trend toward integration of various components. Micro-optics technology has the potential in a number of areas to simplify optical design with improved performance. This includes internally cooled apertures, hybrid optical design, microlenses, dispersive multicolor microlenses, active dither, electronically controlled optical beam steer, and microscopic integration of micro-optics, detectors, and signal processing layers. This paper describes our approach to the development of micro-optics technology with our main emphasis for sensors applications.

Mobilization Function of the pBHR1 Plasmid, a Derivative of the Broad-Host-Range Plasmid pBBR1

PubMed Central

Szpirer, Cédric Y.; Faelen, Michel; Couturier, Martine

2001-01-01

The pBHR1 plasmid is a derivative of the small (2.6-kb), mobilizable broad-host-range plasmid pBBR1, which was isolated from the gram-negative bacterium Bordetella bronchiseptica (R. Antoine and C. Locht, Mol. Microbiol. 6:1785–1799, 1992). Plasmid pBBR1 consists of two functional cassettes and presents sequence similarities with the transfer origins of several plasmids and mobilizable transposons from gram-positive bacteria. We show that the Mob protein specifically recognizes a 52-bp sequence which contains, in addition to the transfer origin, the promoter of the mob gene. We demonstrate that this gene is autoregulated. The binding of the Mob protein to the 52-bp sequence could thus allow the formation of a protein-DNA complex with a double function: relaxosome formation and mob gene regulation. We show that the Mob protein is a relaxase, and we located the nic site position in vitro. After sequence alignment, the position of the nic site of pBBR1 corresponds with those of the nick sites of the Bacteroides mobilizable transposon Tn4555 and the streptococcal plasmid pMV158. The oriT of the latter is characteristic of a family of mobilizable plasmids that are found in gram-positive bacteria and that replicate by the rolling-circle mechanism. Plasmid pBBR1 thus appears to be a new member of this group, even though it resides in gram-negative bacteria and does not replicate via a rolling-circle mechanism. In addition, we identified two amino acids of the Mob protein necessary for its activity, and we discuss their involvement in the mobilization mechanism. PMID:11222611

Single-tube analysis of DNA methylation with silica superparamagnetic beads.

PubMed

Bailey, Vasudev J; Zhang, Yi; Keeley, Brian P; Yin, Chao; Pelosky, Kristen L; Brock, Malcolm; Baylin, Stephen B; Herman, James G; Wang, Tza-Huei

2010-06-01

DNA promoter methylation is a signature for the silencing of tumor suppressor genes. Most widely used methods to detect DNA methylation involve 3 separate, independent processes: DNA extraction, bisulfite conversion, and methylation detection via a PCR method, such as methylation-specific PCR (MSP). This method includes many disconnected steps with associated losses of material, potentially reducing the analytical sensitivity required for analysis of challenging clinical samples. Methylation on beads (MOB) is a new technique that integrates DNA extraction, bisulfite conversion, and PCR in a single tube via the use of silica superparamagnetic beads (SSBs) as a common DNA carrier for facilitating cell debris removal and buffer exchange throughout the entire process. In addition, PCR buffer is used to directly elute bisulfite-treated DNA from SSBs for subsequent target amplifications. The diagnostic sensitivity of MOB was evaluated by methylation analysis of the CDKN2A [cyclin-dependent kinase inhibitor 2A (melanoma, p16, inhibits CDK4); also known as p16(INK4a)] promoter in serum DNA of lung cancer patients and compared with that of conventional methods. Methylation analysis consisting of DNA extraction followed by bisulfite conversion and MSP was successfully carried out within 9 h in a single tube. The median pre-PCR DNA yield was 6.61-fold higher with the MOB technique than with conventional techniques. Furthermore, MOB increased the diagnostic sensitivity in our analysis of the CDKN2A promoter in patient serum by successfully detecting methylation in 74% of cancer patients, vs the 45% detection rate obtained with conventional techniques. The MOB technique successfully combined 3 processes into a single tube, thereby allowing ease in handling and an increased detection throughput. The increased pre-PCR yield in MOB allowed efficient, diagnostically sensitive methylation detection.

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF)

NASA Astrophysics Data System (ADS)

Mueller, Mark; Szentgyorgyi, Andrew; Baldwin, Daniel; Bean, Jacob; Ben-Ami, Sagi; Brennan, Patricia; Budynkiewicz, J.; Chun, Moo-Yung; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Foster, Jeff; Frebel, Anna; Gauron, Thomas; Glenday, Alex; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jordan, Andreas; Kim, Jihun; Kim, Kang-Min; Mendes de Oliveira, Claudia; Lopez-Morales, Mercedes; McCracken, Kenneth; McMuldroch, Stuart; Miller, Joseph; Oh, Jae Sok; Onyuksel, Cem; Ordway, Mark; Park, Chan; Park, Sung-Joon; Paxson, Charles; Phillips, David; Plummer, David; Podgorski, William; Seifahrt, Andreas; Steiner, Joao; Uomoto, Alan; Walsworth, Ronald; Yu, Young-Sam

2016-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical echelle spectrograph selected as the first light instrument for the Giant Magellan Telescope (GMT) now under construction at the Las Campanas Observatory in Chile. G-CLEF has been designed to be a general-purpose echelle spectrograph with precision radial velocity (PRV) capability for exoplanet detection. The radial velocity (RV) precision goal of G-CLEF is 10 cm/sec, necessary for detection of Earth-sized exoplanets. This goal imposes challenging stability requirements on the optical mounts and the overall spectrograph support structures especially when considering the instrument's operational environment. The accuracy of G-CLEF's PRV measurements will be influenced by minute changes in temperature and ambient air pressure as well as vibrations and micro gravity-vector variations caused by normal telescope slewing. For these reasons we have chosen to enclose G-CLEF's spectrograph in a well-insulated, vibration isolated vacuum chamber in a gravity invariant location on GMT's azimuth platform. Additional design constraints posed by the GMT telescope include: a limited space envelope, a thermal emission ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology and budget are also significant design drivers. All of the above considerations must be managed while ensuring performance requirements are achieved. In this paper, we discuss the design of G-CLEF's optical mounts and support structures including the choice of a low coefficient of thermal expansion (CTE) carbon-fiber optical bench to minimize the system's sensitivity to thermal soaks and gradients. We discuss design choices made to the vacuum chamber geared towards minimize the influence of daily ambient pressure variations on image motion during observation. We discuss the design of G-CLEF's insulated enclosure and thermal control systems which will maintain the spectrograph at milli-Kelvin level stability while simultaneously limiting thermal emissions into the telescope dome. Also discussed are micro gravity-vector variations caused by normal telescope slewing, their uncorrected influence on image motion, and how they are dealt with in the design. Finally, we discuss G-CLEF's front-end assembly and fiber-feed system as well as other interface challenges presented by the telescope, enclosure and neighboring instrumentation.

Defining the measurand in radius of curvature measurements

NASA Astrophysics Data System (ADS)

Davies, Angela; Schmitz, Tony L.

2003-11-01

Traceable radius of curvature measurements are critical for precision optics manufacture. An optical bench measurement of radius is very repeatable and is the preferred method for low-uncertainty applications. On an optical bench, the displacement of the optic is measured as it is moved between the cat's eye and confocal positions, each identified using a figure measuring interferometer. Traceability requires connection to a basic unit (the meter, here) in addition to a defensible uncertainty analysis, and the identification and proper propagation of all uncertainty sources in this measurement is challenging. Recent work has focused on identifying all uncertainty contributions; measurement biases have been approximately taken into account and uncertainties combined in an RSS sense for a final measurement estimate and uncertainty. In this paper we report on a new mathematical definition of the radius measurand, which is a single function that depends on all uncertainty sources, such as error motions, alignment uncertainty, displacement gauge uncertainty, etc. The method is based on a homogeneous transformation matrix (HTM) formalism, and intrinsically defines an unbiased estimate for radius, providing a single mathematical expression for uncertainty propagation through a Taylor-series expansion.

[The leadership style as a mitigator of the insurgence of mobbing risk. Results from an empirical research on Italian nurses].

PubMed

Caporale, Loretta; Palese, Alvisa; Bortoluzzi, Guido

2012-01-01

The influence of the organizational factors in mobbing onset, is supported by several studies. The leadership style is considered as one of its main antecedents. To investigate the relation between the leadership style adopted by the Nurse Coordinator and the diffusion of "negative actions", main indicator and antecedent of mobbing onset. Empirical study that involved 175 nurses and obstetricians of a Public Hospital Corporation in North Italy. Data has been collected via a semi-structured and anonymous questionnaire. The results confirm the hypothesis that the adoption of a non-collaborative leadership style goes with a greater diffusion of "negative actions" among the nurses. To intervene on organizational variables, such as the leadership style, allows to reduce the working unease and, therefore, the factors which are linked to it and which bear on the provided relief quality. The results of this study underline the Nurse Coordinator role in preventing and thwarting the onset of "negative actions", which are a potential source for mobbing onset.

You mob my owl, I'll mob yours: birds play tit-for-tat game.

PubMed

Krama, Tatjana; Vrublevska, Jolanta; Freeberg, Todd M; Kullberg, Cecilia; Rantala, Markus J; Krams, Indrikis

2012-01-01

Reciprocity is fundamental to cooperative behaviour and has been verified in theoretical models. However, there is still limited experimental evidence for reciprocity in non-primate species. Our results more decisively clarify that reciprocity with a tit-for-tat enforcement strategy can occur among breeding pied flycatchers Ficedula hypoleuca separate from considerations of byproduct mutualism. Breeding pairs living in close proximity (20-24 m) did exhibit byproduct mutualism and always assisted in mobbing regardless of their neighbours' prior actions. However, breeding pairs with distant neighbours (69-84 m) either assisted or refused to assist in mobbing a predatory owl based on whether or not the distant pair had previously helped them in their own nest defense against the predator. Clearly, these birds are aware of their specific spatial security context, remember their neighbours' prior behaviour, and choose a situation-specific strategic course of action, which could promote their longer-term security, a capacity previously thought unique to primates.

Non-specific alarm calls trigger mobbing behavior in Hainan gibbons (Nomascus hainanus).

PubMed

Deng, Huaiqing; Gao, Kai; Zhou, Jiang

2016-09-30

Alarm calls are important defensive behaviors. Here, we report the acoustic spectrum characteristics of alarm calls produced by Hainan gibbons (Nomascus hainanus) inhabiting Bawangling National Nature Reserve in Hainan, China. Analysis of call data collected from 2002-2014 shows that alarm calls are emitted by all family group members, except infants. Alarm behavior included simple short alarming calls (7-10 min) followed by longer variable-frequency mobbing calls lasting 5-12 min. The duration of individual alarming and mobbing calls was 0.078 ± 0.014 s and 0.154 ± 0.041 s at frequency ranges of 520-1000 Hz and 690-3920 Hz, respectively. Alarming call duration was positively associated with group size. The alarm calls can trigger mobbing behavior in Hainan gibbons; this is a defense way of social animals, and first report among the primates' species. The system of vocal alarm behavior described in this critically endangered species is simple and effective.

You mob my owl, I'll mob yours: birds play tit-for-tat game

PubMed Central

Krama, Tatjana; Vrublevska, Jolanta; Freeberg, Todd M.; Kullberg, Cecilia; Rantala, Markus J.; Krams, Indrikis

2012-01-01

Reciprocity is fundamental to cooperative behaviour and has been verified in theoretical models. However, there is still limited experimental evidence for reciprocity in non-primate species. Our results more decisively clarify that reciprocity with a tit-for-tat enforcement strategy can occur among breeding pied flycatchers Ficedula hypoleuca separate from considerations of byproduct mutualism. Breeding pairs living in close proximity (20–24 m) did exhibit byproduct mutualism and always assisted in mobbing regardless of their neighbours' prior actions. However, breeding pairs with distant neighbours (69–84 m) either assisted or refused to assist in mobbing a predatory owl based on whether or not the distant pair had previously helped them in their own nest defense against the predator. Clearly, these birds are aware of their specific spatial security context, remember their neighbours' prior behaviour, and choose a situation-specific strategic course of action, which could promote their longer-term security, a capacity previously thought unique to primates. PMID:23150772

Mobilization of the relaxable Staphylococcus aureus plasmid pC221 by the conjugative plasmid pGO1 involves three pC221 loci.

PubMed Central

Projan, S J; Archer, G L

1989-01-01

The Staphylococcus aureus plasmid pC221, a 4.6-kilobase multicopy chloramphenicol resistance plasmid that forms plasmid-protein relaxation complexes, was mobilized for transfer by the conjugative plasmid pGO1. Two open reading frames on the pC221 genome, now designated mobA and mobB, as well as a cis-acting locus, the putative oriT, were shown to be in involved in pC221 mobilization. The mobA (but not mobB) and oriT loci were required for pC221 relaxation, and relaxation was necessary but not sufficient for pC221 mobilization by pGO1. oriT was cloned onto a pE194 derivative and complemented in trans for both relaxation and mobilization. Mobilization of relaxable plasmids in S. aureus appears to be analogous to mobilization by donation observed in gram-negative bacteria. Images PMID:2703461

Nrp2 is sufficient to instruct circuit formation of mitral-cells to mediate odour-induced attractive social responses.

PubMed

Inokuchi, Kasumi; Imamura, Fumiaki; Takeuchi, Haruki; Kim, Ryang; Okuno, Hiroyuki; Nishizumi, Hirofumi; Bito, Haruhiko; Kikusui, Takefumi; Sakano, Hitoshi

2017-07-21

Odour information induces various innate responses that are critical to the survival of the individual and for the species. An axon guidance molecule, Neuropilin 2 (Nrp2), is known to mediate targeting of olfactory sensory neurons (primary neurons), to the posteroventral main olfactory bulb (PV MOB) in mice. Here we report that Nrp2-positive (Nrp2 + ) mitral cells (MCs, second-order neurons) play crucial roles in transmitting attractive social signals from the PV MOB to the anterior part of medial amygdala (MeA). Semaphorin 3F, a repulsive ligand to Nrp2, regulates both migration of Nrp2 + MCs to the PV MOB and their axonal projection to the anterior MeA. In the MC-specific Nrp2 knockout mice, circuit formation of Nrp2 + MCs and odour-induced attractive social responses are impaired. In utero, electroporation demonstrates that activation of the Nrp2 gene in MCs is sufficient to instruct their circuit formation from the PV MOB to the anterior MeA.

Deep Proton Writing for the rapid prototyping of polymer micro-components for optical interconnects and optofluidics

NASA Astrophysics Data System (ADS)

Van Erps, Jürgen; Vervaeke, Michael; Ottevaere, Heidi; Hermanne, Alex; Thienpont, Hugo

2013-07-01

The use of photonics in data communication and numerous other industrial applications brought plenty of prospects for innovation and opened up different unexplored market opportunities. This is a major driving force for the fabrication of micro-optical and micro-mechanical structures and their accurate alignment and integration into opto-mechanical modules and systems. To this end, we present Deep Proton Writing (DPW) as a powerful rapid prototyping technology for such micro-components. The DPW process consists of bombarding polymer samples (PMMA or SU-8) with swift protons, which results after chemical processing steps in high-quality micro-optical components. One of the strengths of the DPW micro-fabrication technology is the ability to fabricate monolithic building blocks that include micro-optical and mechanical functionalities which can be precisely integrated into more complex photonic systems. In this paper we comment on how we shifted from using 8.3 to 16.5 MeV protons for DPW and give some examples of micro-optical and micro-mechanical components recently fabricated through DPW, targeting applications in optical interconnections and in optofluidics.

Micro-CT in situ study of carbonate rock microstructural evolution for geologic CO2 storage

NASA Astrophysics Data System (ADS)

Zheng, Y.; Yang, Y.; Rogowska, M.; Gundlach, C.

2017-09-01

To achieve the 2°C target made in the 2016 Paris Agreement, it is essential to reduce the emission of CO2 into the atmosphere. Carbon Capture and Storage (CCS) has been given increasing importance over the last decade. One of the suggested methods for CCS is to inject CO2 into geologic settings such as the carbonate reservoirs in the North Sea. The final aim of our project is to find out how to control the evolution of petrophysical parameters during CO2 injection using an optimal combination of flow rate, injection pressure and chemical composition of the influent. The first step to achieve this is to find a suitable condition to create a stable 3D space in carbonate rock by injecting liquid to prepare space for the later CO2 injection. Micro-CT imaging is a non-destructive 3D method that can be used to study the property changes of carbonate rocks during and after CO2 injection. The advance in lab source based micro-CT has made it capable of in situ experiments. We used a commercial bench top micro-CT (Zeiss Versa XRM410) to study the microstructure changes of chalk during liquid injection. Flexible temporal CT resolution is essential in this study because that the time scales of coupled physical and chemical processes can be very different. The results validated the feasibility of using a bench top CT system with a pressure cell to monitor the mesoscale multiphase interactions in chalk.

Performance of an untethered micro-optical pressure sensor

NASA Astrophysics Data System (ADS)

Ioppolo, Tindaro; Manzo, Maurizio; Krueger, Paul

2012-11-01

We present analytical and computational studies of the performance of a novel untethered micro-optical pressure sensor for fluid dynamics measurements. In particular, resolution and dynamic range will be presented. The sensor concept is based on the whispering galley mode (WGM) shifts that are observed in micro-scale dielectric optical cavities. A micro-spherical optical cavity (liquid or solid) is embedded in a thin polymeric sheet. The applied external pressure perturbs the morphology of the optical cavity leading to a shift in its optical resonances. The optical sensors are interrogated remotely, by embedding quantum dots or fluorescent dye in the micro-optical cavity. This allows a free space coupling of excitation and monitoring of the optical modes without the need of optical fibers or other cabling. With appropriate excitation and monitoring equipment, the micro-scale sensors can be distributed over a surface (e.g., including flexible biological surfaces) to monitor the local pressure field. We acknowledge the financial support from the National Science Foundation through grant CBET-1133876 with Dr. Horst Henning Winter as the program director.

Preliminary research on monitoring the durability of concrete subjected to sulfate attack with optical fibre Raman spectroscopy

NASA Astrophysics Data System (ADS)

Yue, Yanfei; Bai, Yun; Basheer, P. A. Muhammed; Boland, John J.; Wang, Jing Jing

2013-04-01

Formation of ettringite and gypsum from sulfate attack together with carbonation and chloride ingress have been considered as the most serious deterioration mechanisms of concrete structures. Although Electrical Resistance Sensors and Fibre Optic Chemical Sensors could be used to monitoring the latter two mechanisms in situ, currently there is no system for monitoring the deterioration mechanisms of sulfate attack and hence still needs to be developed. In this paper, a preliminary study was carried out to investigate the feasibility of monitoring the sulfate attack with optical fibre Raman spectroscopy through characterizing the ettringite and gypsum formed in deteriorated cementitious materials under an `optical fibre excitation + spectroscopy objective collection' configuration. Bench-mounted Raman spectroscopy analysis was also used to validate the spectrum obtained from the fibre-objective configuration. The results showed that the expected Raman bands of ettringite and gypsum in the sulfate attacked cement paste have been clearly identified by the optical fibre Raman spectroscopy and are in good agreement with those identified from bench-mounted Raman spectroscopy. Therefore, based on these preliminary results, there is a good potential of developing an optical fibre Raman spectroscopy-based system for monitoring the deterioration mechanisms of concrete subjected to the sulfate attack in the future.

[Mobbing, bullying and other forms of aggression among pupils as a source of stress in school. How far the "victims" are involved?].

PubMed

Seiffge-Krenke, Inge; Welter, Nicole

2008-01-01

Aggression among pupils is one of the frequent sources of stress in school. Aggression among pupils can display diverse forms and also has different origins. In this contribution, bullying, mobbing and relational aggression as different forms of aggression were described, based on recent research. In addition, a psychoanalytic treatment of a female adolescent is presented who suffered from mobbing. The treatment includes 70 hours work with the female patient and additional work with her parents. Based on this case study, it became obvious that it necessary to precisely analyse the own contribution for eliciting and maintaining aggression.

Mob grazing for dairy cows

USDA-ARS?s Scientific Manuscript database

Proponents of mob grazing emphasize increased forage use efficiency and soil improvement by grazing mature forage with stocking densities up to 560,425 lb/ac of beef cattle on small paddocks with rest periods up to 125 days. However, it is unclear if this management technique is appropriate for dair...

Micro-optics for microfluidic analytical applications.

PubMed

Yang, Hui; Gijs, Martin A M

2018-02-19

This critical review summarizes the developments in the integration of micro-optical elements with microfluidic platforms for facilitating detection and automation of bio-analytical applications. Micro-optical elements, made by a variety of microfabrication techniques, advantageously contribute to the performance of an analytical system, especially when the latter has microfluidic features. Indeed the easy integration of optical control and detection modules with microfluidic technology helps to bridge the gap between the macroscopic world and chip-based analysis, paving the way for automated and high-throughput applications. In our review, we start the discussion with an introduction of microfluidic systems and micro-optical components, as well as aspects of their integration. We continue with a detailed description of different microfluidic and micro-optics technologies and their applications, with an emphasis on the realization of optical waveguides and microlenses. The review continues with specific sections highlighting the advantages of integrated micro-optical components in microfluidic systems for tackling a variety of analytical problems, like cytometry, nucleic acid and protein detection, cell biology, and chemical analysis applications.

Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing

PubMed Central

Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette

2015-01-01

Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing. PMID:26353118

Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing.

PubMed

Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette

2015-01-01

Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing.

Design of micro-ring optical sensors and circuits for integration on optical printed circuit boards (O-PCBs)

NASA Astrophysics Data System (ADS)

Lee, El-Hang; Lee, Hyun S.; Lee, S. G.; O, B. H.; Park, S. G.; Kim, K. H.

2007-05-01

We report on the design of micro-ring resonator optical sensors for integration on what we call optical printed circuit boards (O-PCBs). The objective is to realize application-specific O-PCBs, either on hard board or on flexible board, by integrating micro/nano-scale optical sensors for compact, light-weight, low-energy, high-speed, intelligent, and environmentally friendly processing of information. The O-PCBs consist of two-dimensional planar arrays of micro/nano-scale optical wires, circuits and devices that are interconnected and integrated to perform the functions of sensing and then storing, transporting, processing, switching, routing and distributing optical signals that have been collected by means of sensors. For fabrication, the polymer and organic optical wires and waveguides are first fabricated on a board and are used to interconnect and integrate sensors and other micro/ nano-scale photonic devices. Here, in our study, we focus on the sensors based on the micro-ring structures. We designed bio-sensors using silicon based micro-ring resonator. We investigate the characteristics such as sensitivity and selectivity (or quality factor) of micro-ring resonator for their use in bio-sensing application. We performed simulation studies on the quality factor of micro-ring resonators by varying the radius of the ring resonators and the separation between adjacent waveguides. We introduce the effective coupling coefficient as a realistic value to describe the strength of the coupling in micro-ring resonators.

Test-bench system for a borehole azimuthal acoustic reflection imaging logging tool

NASA Astrophysics Data System (ADS)

Liu, Xianping; Ju, Xiaodong; Qiao, Wenxiao; Lu, Junqiang; Men, Baiyong; Liu, Dong

2016-06-01

The borehole azimuthal acoustic reflection imaging logging tool (BAAR) is a new generation of imaging logging tool, which is able to investigate stratums in a relatively larger range of space around the borehole. The BAAR is designed based on the idea of modularization with a very complex structure, so it has become urgent for us to develop a dedicated test-bench system to debug each module of the BAAR. With the help of a test-bench system introduced in this paper, test and calibration of BAAR can be easily achieved. The test-bench system is designed based on the client/server model. The hardware system mainly consists of a host computer, an embedded controlling board, a bus interface board, a data acquisition board and a telemetry communication board. The host computer serves as the human machine interface and processes the uploaded data. The software running on the host computer is designed based on VC++. The embedded controlling board uses Advanced Reduced Instruction Set Machines 7 (ARM7) as the micro controller and communicates with the host computer via Ethernet. The software for the embedded controlling board is developed based on the operating system uClinux. The bus interface board, data acquisition board and telemetry communication board are designed based on a field programmable gate array (FPGA) and provide test interfaces for the logging tool. To examine the feasibility of the test-bench system, it was set up to perform a test on BAAR. By analyzing the test results, an unqualified channel of the electronic receiving cabin was discovered. It is suggested that the test-bench system can be used to quickly determine the working condition of sub modules of BAAR and it is of great significance in improving production efficiency and accelerating industrial production of the logging tool.

From hub to MOB: a strategy to extend your hospital's reach.

PubMed

Arnold, David C

2007-11-01

When used effectively for strategic purposes, a successful MOB will: Align physicians with the hospital. Increase ancillary utilization, improving the hospital's bottom line Support physician recruitment. Allow the hospital to reallocate capital for operational needs. Improve the hospital's image. Expand the hospital's geographical market share. Enhance physicians' revenue.

Mobbing: Workplace Violence in the Academy

ERIC Educational Resources Information Center

Keim, Jeanmarie; McDermott, J. Cynthia

2010-01-01

Incidents of workplace violence are becoming all too common at colleges and universities. Generally, one thinks of shootings and assaults in relation to campus workplace violence. However, mobbing and bullying of faculty by other faculty are types of workplace violence that, while very common, are rarely discussed or reported. This article raises…

Improved selectivity from a wavelength addressable device for wireless stimulation of neural tissue

PubMed Central

Seymour, Elif Ç.; Freedman, David S.; Gökkavas, Mutlu; Özbay, Ekmel; Sahin, Mesut; Ünlü, M. Selim

2014-01-01

Electrical neural stimulation with micro electrodes is a promising technique for restoring lost functions in the central nervous system as a result of injury or disease. One of the problems related to current neural stimulators is the tissue response due to the connecting wires and the presence of a rigid electrode inside soft neural tissue. We have developed a novel, optically activated, microscale photovoltaic neurostimulator based on a custom layered compound semiconductor heterostructure that is both wireless and has a comparatively small volume (<0.01 mm3). Optical activation provides a wireless means of energy transfer to the neurostimulator, eliminating wires and the associated complications. This neurostimulator was shown to evoke action potentials and a functional motor response in the rat spinal cord. In this work, we extend our design to include wavelength selectivity and thus allowing independent activation of devices. As a proof of concept, we fabricated two different microscale devices with different spectral responsivities in the near-infrared region. We assessed the improved addressability of individual devices via wavelength selectivity as compared to spatial selectivity alone through on-bench optical measurements of the devices in combination with an in vivo light intensity profile in the rat cortex obtained in a previous study. We show that wavelength selectivity improves the individual addressability of the floating stimulators, thus increasing the number of devices that can be implanted in close proximity to each other. PMID:24600390

MicroRNAs in cancer therapeutics: "from the bench to the bedside".

PubMed

Monroig-Bosque, Paloma del C; Rivera, Carlos A; Calin, George A

2015-01-01

MicroRNAs (miRNAs) are non-coding RNA transcripts that regulate physiological processes by targeting proteins directly. Their involvement in research has been robust, and evidence of their regulative functions has granted them the title: master regulators of the human genome. In cancer, they are considered important therapeutic agents, due to the fact that their aberrant expression contributes to disease development, progression, metastasis, therapeutic response and patient overall survival. This has endeavored fields of biomedical sciences to invest in developing and exploiting miRNA-based therapeutics thoroughly. Herein we highlight relevant ongoing/open clinical trials involving miRNAs and cancer.

A micro-vibration generated method for testing the imaging quality on ground of space remote sensing

NASA Astrophysics Data System (ADS)

Gu, Yingying; Wang, Li; Wu, Qingwen

2018-03-01

In this paper, a novel method is proposed, which can simulate satellite platform micro-vibration and test the impact of satellite micro-vibration on imaging quality of space optical remote sensor on ground. The method can generate micro-vibration of satellite platform in orbit from vibrational degrees of freedom, spectrum, magnitude, and coupling path. Experiment results show that the relative error of acceleration control is within 7%, in frequencies from 7Hz to 40Hz. Utilizing this method, the system level test about the micro-vibration impact on imaging quality of space optical remote sensor can be realized. This method will have an important applications in testing micro-vibration tolerance margin of optical remote sensor, verifying vibration isolation and suppression performance of optical remote sensor, exploring the principle of micro-vibration impact on imaging quality of optical remote sensor.

Fabrication of micro/nano optical fiber by mechano-electrospinning

NASA Astrophysics Data System (ADS)

Chen, Qinnan; Wu, Dezhi; Yu, Zhe; Mei, Xuecui; Fang, Ke; Sun, Daoheng

2017-10-01

We study a novel fabrication method of micro/nano optical fiber by mechano-electrospinning (MES) direct-written technology. MES process is able to precisely manipulate the position and diameter of the electro-spun micro/nano fiber by adjusting the mechanical drawing force, which through changing the speed of motion stage (substrate). By adjusting the substrate speed, the nozzle-to-substrate distance and the applied voltage, the poly(methyl methacrylate) (PMMA) micro/nano optical fibers (MNOF) with controlled diameter are obtained and the tapered MNOF are fabricated by continuously changing the substrate speed. The transmission characteristics of PMMA micro/nano fiber is experimentally demonstrated, and a PMMA micro/nano fiber based refractive index sensor is designed. Our works shows the new fabrication method of MNOF by MES has the potential in the field of light mode conversion, optical waveguide coupling, refractive index detection and new micro/nano optical fiber components.

Social learning of a brood parasite by its host

PubMed Central

Feeney, William E.; Langmore, Naomi E.

2013-01-01

Arms races between brood parasites and their hosts provide model systems for studying the evolutionary repercussions of species interactions. However, how naive hosts identify brood parasites as enemies remains poorly understood, despite its ecological and evolutionary significance. Here, we investigate whether young, cuckoo-naive superb fairy-wrens, Malurus cyaneus, can learn to recognize cuckoos as a threat through social transmission of information. Naive individuals were initially unresponsive to a cuckoo specimen, but after observing conspecifics mob a cuckoo, they made more whining and mobbing alarm calls, and spent more time physically mobbing the cuckoo. This is the first direct evidence that naive hosts can learn to identify brood parasites as enemies via social learning. PMID:23760171

Social learning of a brood parasite by its host.

PubMed

Feeney, William E; Langmore, Naomi E

2013-08-23

Arms races between brood parasites and their hosts provide model systems for studying the evolutionary repercussions of species interactions. However, how naive hosts identify brood parasites as enemies remains poorly understood, despite its ecological and evolutionary significance. Here, we investigate whether young, cuckoo-naive superb fairy-wrens, Malurus cyaneus, can learn to recognize cuckoos as a threat through social transmission of information. Naive individuals were initially unresponsive to a cuckoo specimen, but after observing conspecifics mob a cuckoo, they made more whining and mobbing alarm calls, and spent more time physically mobbing the cuckoo. This is the first direct evidence that naive hosts can learn to identify brood parasites as enemies via social learning.

[Woman's experience with the choice of the Billings Ovulation Method].

PubMed

de Magalhães, Adriana Cristina; Pereira, Daliane da Silva Alves; Jardim, Danúbia Mariane Barbosa; Caillaux, Michelle; Sales, Vinícius Bernardo Lemos

2013-01-01

This is a case study with a qualitative approach, carried out between February and November 2010 with 10 women, mean age of 34 years old, users of this Billings Ovulation Method (MOB) for over than two years, with the objective of understand the experience of women by choosing the MOB. Data was obtained from interviews, and analyzed through content analysis technique. The categories of analysis showed that the reasons for the choices of the MOB were: religion; natural method, and benefits of self-knowledge. It was concluded that women show confidence in carrying out the method, that it brings benefits for users and that there is a need for professional guidance for its correct practice.

[Aggression and mobbing among correctional officers].

PubMed

Merecz-Kot, Dorota; Cebrzyńska, Joanna

2008-01-01

The paper addresses the issue of violence among correctional officers. The aim of the study was to assess the frequency of exposure to violence in this professional group. The study comprised the sample of 222 correctional officers who voluntary and anonymously fulfilled the MDM questionnaire. The MDM Questionnaire allows for assessing exposure to aggression and mobbing at work. Preliminary assessment of exposure to single aggressive acts and mobbing shows a quite alarming tendency--around one third of subjects under the study experienced repetitive aggressive acts from coworkers and/or superiors. The problem of organizational aggression in correctional institutions should be recognized in details to develop effective preventive measures against violent behaviors occurring at work.

Workplace mobbing and effects on workers' health.

PubMed

Meseguer de Pedro, Mariano; Soler Sánchez, María Isabel; Sáez Navarro, María Concepción; García Izquierdo, Mariano

2008-05-01

In this work, we analyze various consequences of the phenomenon of mobbing on the health of a work sector with special characteristics: the agro fruit sector. For this purpose, we collected data from a sample of 396 workers (61 men and 331 women) belonging to this sector in the Region of Murcia (Spain). A questionnaire with the following measurement instruments was administered: a Spanish adaptation of the revised Negative Acts Questionnaire (Sáez, García, & Llor, 2003), the Psychosomatic Problems Questionnaire (Hock, 1988), and a measure of absenteeism. The results revealed a significant and positive relation between workplace mobbing and psychosomatic symptoms, but not with absenteeism. The implications of the results for future research are discussed.

Microsystem enabled photovoltaic modules and systems

DOEpatents

Nielson, Gregory N; Sweatt, William C; Okandan, Murat

2015-05-12

A microsystem enabled photovoltaic (MEPV) module including: an absorber layer; a fixed optic layer coupled to the absorber layer; a translatable optic layer; a translation stage coupled between the fixed and translatable optic layers; and a motion processor electrically coupled to the translation stage to controls motion of the translatable optic layer relative to the fixed optic layer. The absorber layer includes an array of photovoltaic (PV) elements. The fixed optic layer includes an array of quasi-collimating (QC) micro-optical elements designed and arranged to couple incident radiation from an intermediate image formed by the translatable optic layer into one of the PV elements such that it is quasi-collimated. The translatable optic layer includes an array of focusing micro-optical elements corresponding to the QC micro-optical element array. Each focusing micro-optical element is designed to produce a quasi-telecentric intermediate image from substantially collimated radiation incident within a predetermined field of view.

Novel Payload Architectures for LISA

NASA Astrophysics Data System (ADS)

Johann, Ulrich A.; Gath, Peter F.; Holota, Wolfgang; Schulte, Hans Reiner; Weise, Dennis

2006-11-01

As part of the current LISA Mission Formulation Study, and based on prior internal investigations, Astrium Germany has defined and preliminary assessed novel payload architectures, potentially reducing overall complexity and improving budgets and costs. A promising concept is characterized by a single active inertial sensor attached to a single optical bench and serving both adjacent interferometer arms via two rigidly connected off-axis telescopes. The in-plane triangular constellation ``breathing angle'' compensation is accomplished by common telescope in-field of view pointing actuation of the transmit/received beams line of sight. A dedicated actuation mechanism located on the optical bench is required in addition to the on bench actuators for differential pointing of the transmit and receive direction perpendicular to the constellation plane. Both actuators operate in a sinusoidal yearly period. A technical challenge is the actuation mechanism pointing jitter and the monitoring and calibration of the laser phase walk which occurs while changing the optical path inside the optical assembly during re-pointing. Calibration or monitoring of instrument internal phase effects e.g. by a laser metrology truss derived from the existing interferometry is required. The architecture exploits in full the two-step interferometry (strap down) concept, separating functionally inter spacecraft and intra-spacecraft interferometry (reference mass laser metrology degrees of freedom sensing). The single test mass is maintained as cubic, but in free-fall in the lateral degrees of freedom within the constellation plane. Also the option of a completely free spherical test mass with full laser interferometer readout has been conceptually investigated. The spherical test mass would rotate slowly, and would be allowed to tumble. Imperfections in roundness and density would be calibrated from differential wave front sensing in a tetrahedral arrangement, supported by added attitude information via a grid of tick marks etched onto the surface and monitored by the laser readout.

Advanced structural design for precision radial velocity instruments

NASA Astrophysics Data System (ADS)

Baldwin, Dan; Szentgyorgyi, Andrew; Barnes, Stuart; Bean, Jacob; Ben-Ami, Sagi; Brennan, Patricia; Budynkiewicz, Jamie; Chun, Moo-Young; Conroy, Charlie; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Foster, Jeff; Frebel, Anna; Gauron, Thomas; Guzman, Dani; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jordan, Andres; Kim, Jihun; Kim, Kang-Min; Mendes de Oliveira, Claudia; Lopez-Morales, Mercedes; McCracken, Kenneth; McMuldroch, Stuart; Miller, Joseph; Mueller, Mark; Oh, Jae Sok; Ordway, Mark; Park, Byeong-Gon; Park, Chan; Park, Sung-Joon; Paxson, Charles; Phillips, David; Plummer, David; Podgorski, William; Seifahrt, Andreas; Stark, Daniel; Steiner, Joao; Uomoto, Alan; Walsworth, Ronald; Yu, Young-Sam

2016-07-01

The GMT-Consortium Large Earth Finder (G-CLEF) is an echelle spectrograph with precision radial velocity (PRV) capability that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF has a PRV precision goal of 40 cm/sec (10 cm/s for multiple measurements) to enable detection of Earth-like exoplanets in the habitable zones of sun-like stars1. This precision is a primary driver of G-CLEF's structural design. Extreme stability is necessary to minimize image motions at the CCD detectors. Minute changes in temperature, pressure, and acceleration environments cause structural deformations, inducing image motions which degrade PRV precision. The instrument's structural design will ensure that the PRV goal is achieved under the environments G-CLEF will be subjected to as installed on the GMT azimuth platform, including: Millikelvin (0.001 °K) thermal soaks and gradients 10 millibar changes in ambient pressure Changes in acceleration due to instrument tip/tilt and telescope slewing Carbon fiber/cyanate composite was selected for the optical bench structure in order to meet performance goals. Low coefficient of thermal expansion (CTE) and high stiffness-to-weight are key features of the composite optical bench design. Manufacturability and serviceability of the instrument are also drivers of the design. In this paper, we discuss analyses leading to technical choices made to minimize G-CLEF's sensitivity to changing environments. Finite element analysis (FEA) and image motion sensitivity studies were conducted to determine PRV performance under operational environments. We discuss the design of the optical bench structure to optimize stiffness-to-weight and minimize deformations due to inertial and pressure effects. We also discuss quasi-kinematic mounting of optical elements and assemblies, and optimization of these to ensure minimal image motion under thermal, pressure, and inertial loads expected during PRV observations.

Micro-optical design of a three-dimensional microlens scanner for vertically integrated micro-opto-electro-mechanical systems.

PubMed

Baranski, Maciej; Bargiel, Sylwester; Passilly, Nicolas; Gorecki, Christophe; Jia, Chenping; Frömel, Jörg; Wiemer, Maik

2015-08-01

This paper presents the optical design of a miniature 3D scanning system, which is fully compatible with the vertical integration technology of micro-opto-electro-mechanical systems (MOEMS). The constraints related to this integration strategy are considered, resulting in a simple three-element micro-optical setup based on an afocal scanning microlens doublet and a focusing microlens, which is tolerant to axial position inaccuracy. The 3D scanning is achieved by axial and lateral displacement of microlenses of the scanning doublet, realized by micro-electro-mechanical systems microactuators (the transmission scanning approach). Optical scanning performance of the system is determined analytically by use of the extended ray transfer matrix method, leading to two different optical configurations, relying either on a ball lens or plano-convex microlenses. The presented system is aimed to be a core component of miniature MOEMS-based optical devices, which require a 3D optical scanning function, e.g., miniature imaging systems (confocal or optical coherence microscopes) or optical tweezers.

Perform light and optic experiments in Augmented Reality

NASA Astrophysics Data System (ADS)

Wozniak, Peter; Vauderwange, Oliver; Curticapean, Dan; Javahiraly, Nicolas; Israel, Kai

2015-10-01

In many scientific studies lens experiments are part of the curriculum. The conducted experiments are meant to give the students a basic understanding for the laws of optics and its applications. Most of the experiments need special hardware like e.g. an optical bench, light sources, apertures and different lens types. Therefore it is not possible for the students to conduct any of the experiments outside of the university's laboratory. Simple optical software simulators enabling the students to virtually perform lens experiments already exist, but are mostly desktop or web browser based. Augmented Reality (AR) is a special case of mediated and mixed reality concepts, where computers are used to add, subtract or modify one's perception of reality. As a result of the success and widespread availability of handheld mobile devices, like e.g. tablet computers and smartphones, mobile augmented reality applications are easy to use. Augmented reality can be easily used to visualize a simulated optical bench. The students can interactively modify properties like e.g. lens type, lens curvature, lens diameter, lens refractive index and the positions of the instruments in space. Light rays can be visualized and promote an additional understanding of the laws of optics. An AR application like this is ideally suited to prepare the actual laboratory sessions and/or recap the teaching content. The authors will present their experience with handheld augmented reality applications and their possibilities for light and optic experiments without the needs for specialized optical hardware.

Teaching "Banished". A Facing History and Ourselves Study Guide

ERIC Educational Resources Information Center

Bacote, Catina

2009-01-01

Thousands of African Americans were banished from their communities by violent mobs in the late nineteenth century and the early part of the twentieth. The banishments happened quickly, sometimes overnight. Mobs would often lynch one or more men and then go through town burning down homes and churches and shooting at individuals. The African…

A Scale of Mobbing Impacts

ERIC Educational Resources Information Center

Yaman, Erkan

2012-01-01

The aim of this research was to develop the Mobbing Impacts Scale and to examine its validity and reliability analyses. The sample of study consisted of 509 teachers from Sakarya. In this study construct validity, internal consistency, test-retest reliabilities and item analysis of the scale were examined. As a result of factor analysis for…

Relationship between Organizational Mobbing and Silence Behavior among Teachers

ERIC Educational Resources Information Center

Hüsrevsahi, Selda Polat

2015-01-01

This study mainly aims to investigate the correlation between teachers' exposure to mobbing in their workplaces and their display of the act of silence. This study is based on a survey design where data from 312 teachers were collected and analyzed using correlation and regression analyses. Specifically, "The Structure and Dimensions of…

Luteinizing hormone-releasing hormone (LHRH) in rat olfactory systems.

PubMed

Witkin, J W; Silverman, A J

1983-08-20

The luteinizing hormone-releasing hormone (LHRH) systems of rat olfactory bulbs and nasal areas were studied in neonatal and adult rats. Animals were perfused with Zamboni's fixative and olfactory bulbs with nasal olfactory areas intact were removed, postfixed, and decalcified. LHRH was immunohistochemically demonstrated in unembedded frozen or vibratome sections. Luteinizing hormone-releasing hormone immunoreactive elements were found along the course of the nervus terminalis (NT) and within both the main and accessory olfactory bulbs (MOB and AOB, respectively). Both LHRH neurons and fibers were present in the AOB, but only fibers were detected in the MOB. The fibers of the AOB were not confined to any particular lamina while fibers in the MOB were found mainly in the external plexiform layer. LHRH fibers were found in the mucosa of the olfactory epithelium of the vomeronasal organ in both neonatal and adult rats. The NT probably serves as a source of LHRH fibers for both the AOB and the MOB and for fibers observed in the olfactory epithelium of the vomeronasal organ. Other likely sources of LHRH fibers in the olfactory bulb are discussed.

Olfactory fingerprints for major histocompatibility complex-determined body odors.

PubMed

Schaefer, M L; Young, D A; Restrepo, D

2001-04-01

Recognition of individual body odors is analogous to human face recognition in that it provides information about identity. Individual body odors determined by differences at the major histocompatibility complex (MHC or H-2) have been shown to influence mate choice, pregnancy block, and maternal behavior in mice. Unfortunately, the mechanism and extent of the main olfactory bulb (MOB) and accessory olfactory bulb (AOB) involvement in the discrimination of animals according to H-2-type has remained ambiguous. Here we study the neuronal activation patterns evoked in the MOB in different individuals on exposure to these complex, biologically meaningful sensory stimuli. We demonstrate that body odors from H-2 disparate mice evoke overlapping but distinct maps of neuronal activation in the MOB. The spatial patterns of odor-evoked activity are sufficient to be used like fingerprints to predict H-2 identity using a novel computer algorithm. These results provide functional evidence for discrimination of H-2-determined body odors in the MOB, but do not preclude a role for the AOB. These data further our understanding of the neural strategies used to decode socially relevant odors.

Non-specific alarm calls trigger mobbing behavior in Hainan gibbons (Nomascus hainanus)

PubMed Central

Deng, Huaiqing; Gao, Kai; Zhou, Jiang

2016-01-01

Alarm calls are important defensive behaviors. Here, we report the acoustic spectrum characteristics of alarm calls produced by Hainan gibbons (Nomascus hainanus) inhabiting Bawangling National Nature Reserve in Hainan, China. Analysis of call data collected from 2002–2014 shows that alarm calls are emitted by all family group members, except infants. Alarm behavior included simple short alarming calls (7–10 min) followed by longer variable-frequency mobbing calls lasting 5–12 min. The duration of individual alarming and mobbing calls was 0.078 ± 0.014 s and 0.154 ± 0.041 s at frequency ranges of 520–1000 Hz and 690–3920 Hz, respectively. Alarming call duration was positively associated with group size. The alarm calls can trigger mobbing behavior in Hainan gibbons; this is a defense way of social animals, and first report among the primates’ species. The system of vocal alarm behavior described in this critically endangered species is simple and effective. PMID:27686623

[Discriminating capacity of the MASI-R questionnaire in the perception of work-stress].

PubMed

Giorgi, Ines; Mainetti, Paolo; Fiabane, Elena; Bertolotti, Giorgio; Baiardi, Paola; Massidda, Davide; Tringali, Salvatore; Candura, Stefano Massimo; Imbriani, Marcello

2014-01-01

Workplace mobbing represents a severe type of occupational stress. The aim of this study is to evaluate the discriminant validity of the Maugeri Stress Index-Revised questionnaire (MASI-R) for the perceived work stress assessment. A total of 105 patients were enrolled at the Occupational Medicine Uinit of our Institute for mobbing-related issues; they were compared to a control group matched for age, sex and professional category. Work stress perception was assessed in both samples using the self-report questionnaire MASI-R, which is the Maugeri Stress Index short form. Workers who perceived exposure to mobbing scored significantly lower compared to the control group in the four MASI-R scales (p < 0.001) and in the two visual analogue scales measuring job satisfaction (p < 0.001) and life satisfaction (p < 0.001). Further analyses have identified the items which significant discriminate between the two groups of workers. These findings show a good discriminant validity of the MASI-R questionnaire: workers who perceived exposure to workplace mobbing reveal higher work stress levels compared to the control group in all aspects measured.

Elimination of methane in exhaust gas from biogas upgrading process by immobilized methane-oxidizing bacteria.

PubMed

Wu, Ya-Min; Yang, Jing; Fan, Xiao-Lei; Fu, Shan-Fei; Sun, Meng-Ting; Guo, Rong-Bo

2017-05-01

Biogas upgrading is essential for the comprehensive utilization of biogas as substitute of natural gas. However, the methane in the biogas can be fully recovered during the upgrading process of biogas, and the exhaust gas produced during biogas upgrading may contain a very low concentration of methane. If the exhaust gas with low concentration methane releases to atmosphere, it will be harmful to environment. In addition, the utilization of large amounts of digestate produced from biogas plant is another important issue for the development of biogas industry. In this study, solid digestate was used to produce active carbon, which was subsequently used as immobilized material for methane-oxidizing bacteria (MOB) in biofilter. Biofilter with MOB immobilized on active carbon was used to eliminate the methane in exhaust gas from biogas upgrading process. Results showed porous active carbon was successfully made from solid digestate. The final methane elimination capacity of immobilized MOB reached about 13molh -1 m -3 , which was more 4 times higher than that of MOB without immobilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mob justice in Tanzania: a medico-social problem.

PubMed

Ng'walali, Paul M; Kitinya, James N

2006-03-01

To investigate the magnitude of mob justice and associated factors. Mob justice is a social and public health problem that has grown in Tanzania in recent decades that has negative effects on social and health of the country, communities, and families. A four-year autopsy study was conducted at the Department of Pathology, MUCHS. Information on the cases was obtained from police, the relatives, friends and other witnesses if available. 1,249 persons were killed by mobs in Dar es Salaam during the period of 5 years (2000-2004). The alleged offense ranged from a serious crime like theft or murder to a mere violation of local customs or religious beliefs. The mode of the killings were mostly burning (48.11%) and stoning (49.96%). Other modes accounted for only 3.0% of the cases. The pattern of injuries ranged from skull and other skeletal fractures to viscera rupture. MJ is a social, legal and public health problem in Tanzania that needs immediate attention. Unemployment of youth and perceived economic inequalities should be addressed. As long as the judicial system doesn't work and corruption is not punished, people will continue to organize their own trials and judge their suspects in the street. These must be tackled in order to reduce the growing incidences of mob justice, hence saving life. It must be ensured that criminals do not violate the freedom, dignity and respect of each and every human or member of the society.

Early reduction of matrix metalloproteinase-8 serum levels is associated with leptin drop and predicts diabetes remission after bariatric surgery.

PubMed

Liberale, Luca; Bonaventura, Aldo; Carbone, Federico; Bertolotto, Maria; Contini, Paola; Scopinaro, Nicola; Camerini, Giovanni Bruno; Papadia, Francesco Saverio; Cordera, Renzo; Camici, Giovanni Guido; Dallegri, Franco; Adami, Gian Franco; Montecucco, Fabrizio

2017-10-15

We aimed at investigating whether the acute abrogation of leptin after bariatric surgery is able to reduce neutrophil activation and potentially affect type 2 diabetes mellitus (T2DM) remission. Metabolic and inflammatory parameters (i.e. leptin, IL-6 and neutrophil products) were compared at baseline (before bariatric surgery), one month, one and three years after surgery in morbid obese (MOB) T2DM patients (n=12) and non-MOB controls (n=32). In vitro, the effects of leptin on Il-6-induced human neutrophil degranulation and integrin upregulation were assessed. At baseline, MOB T2DM patients had a similar demographic, lipid and glycemic profiles than non-MOB T2DM controls, but higher levels of inflammatory mediators, such as CRP, fibrinogen, neutrophil-to-lymphocyte ratio (NLR), matrix metalloproteinase (MMP)-8 and leptin. One month after surgery, CRP, fibrinogen and MMP-8 were reduced only in MOB T2DM patients, while serum leptin was reduced in both groups. In the overall cohort, leptin and MMP-8 drops from baseline to one month post-surgery were positively correlated (Δleptin vs. ΔMMP8: r=0.391, p=0.025). Moreover, ΔMMP8 inversely correlated with fasting glucose levels at one-year follow-up and with glycated hemoglobin at both one- and three-year. At the cut-off point identified by ROC curve analysis (>0ng/mL), ΔMMP8 predicted complete T2DM remission at 3-year follow-up. In vitro, leptin increased IL-6-induced MMP-8 release and abrogated CD18 up-regulation. Bariatric surgery is associated to an acute abrogation of leptin that could affect MMP-8 levels, particularly in MOB T2DM patients. This beneficial event is associated with T2DM remission at 3-year follow-up. Copyright © 2017 Elsevier B.V. All rights reserved.

High Temporal and Spatial Variability of Atmospheric-Methane Oxidation in Alpine Glacier Forefield Soils

PubMed Central

Chiri, Eleonora; Nauer, Philipp A.; Rainer, Edda-Marie; Zeyer, Josef

2017-01-01

ABSTRACT Glacier forefield soils can provide a substantial sink for atmospheric CH4, facilitated by aerobic methane-oxidizing bacteria (MOB). However, MOB activity, abundance, and community structure may be affected by soil age, MOB location in different forefield landforms, and temporal fluctuations in soil physical parameters. We assessed the spatial and temporal variability of atmospheric-CH4 oxidation in an Alpine glacier forefield during the snow-free season of 2013. We quantified CH4 flux in soils of increasing age and in different landforms (sandhill, terrace, and floodplain forms) by using soil gas profile and static flux chamber methods. To determine MOB abundance and community structure, we employed pmoA gene-based quantitative PCR and targeted amplicon sequencing. Uptake of CH4 increased in magnitude and decreased in variability with increasing soil age. Sandhill soils exhibited CH4 uptake rates ranging from −3.7 to −0.03 mg CH4 m−2 day−1. Floodplain and terrace soils exhibited lower uptake rates and even intermittent CH4 emissions. Linear mixed-effects models indicated that soil age and landform were the dominating factors shaping CH4 flux, followed by cumulative rainfall (weighted sum ≤4 days prior to sampling). Of 31 MOB operational taxonomic units retrieved, ∼30% were potentially novel, and ∼50% were affiliated with upland soil clusters gamma and alpha. The MOB community structures in floodplain and terrace soils were nearly identical but differed significantly from the highly variable sandhill soil communities. We concluded that soil age and landform modulate the soil CH4 sink strength in glacier forefields and that recent rainfall affects its short-term variability. This should be taken into account when including this environment in future CH4 inventories. IMPORTANCE Oxidation of methane (CH4) in well-drained, “upland” soils is an important mechanism for the removal of this potent greenhouse gas from the atmosphere. It is largely mediated by aerobic, methane-oxidizing bacteria (MOB). Whereas there is abundant information on atmospheric-CH4 oxidation in mature upland soils, little is known about this important function in young, developing soils, such as those found in glacier forefields, where new sediments are continuously exposed to the atmosphere as a result of glacial retreat. In this field-based study, we investigated the spatial and temporal variability of atmospheric-CH4 oxidation and associated MOB communities in Alpine glacier forefield soils, aiming at better understanding the factors that shape the sink for atmospheric CH4 in this young soil ecosystem. This study contributes to the knowledge on the dynamics of atmospheric-CH4 oxidation in developing upland soils and represents a further step toward the inclusion of Alpine glacier forefield soils in global CH4 inventories. PMID:28687652

The Opaque Projector: The Inverse of the Camera Obscura

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

2011-01-01

Many years ago I was running the standard laboratory experiment on thin lens optics. The source was the usual self illuminated object mounted on an optical bench, and a converging lens formed a real image on a screen. One of the students sitting near one wall of the darkened lab was having some trouble with the idea of image formation. Her face…

Hectospec, the MMT's 300 Optical Fiber-Fed Spectrograph

NASA Astrophysics Data System (ADS)

Fabricant, Daniel; Fata, Robert; Roll, John; Hertz, Edward; Caldwell, Nelson; Gauron, Thomas; Geary, John; McLeod, Brian; Szentgyorgyi, Andrew; Zajac, Joseph; Kurtz, Michael; Barberis, Jack; Bergner, Henry; Brown, Warren; Conroy, Maureen; Eng, Roger; Geller, Margaret; Goddard, Richard; Honsa, Michael; Mueller, Mark; Mink, Douglas; Ordway, Mark; Tokarz, Susan; Woods, Deborah; Wyatt, William; Epps, Harland; Dell'Antonio, Ian

2005-12-01

The Hectospec is a 300 optical fiber fed spectrograph commissioned at the MMT in the spring of 2004. In the configuration pioneered by the Autofib instrument at the Anglo-Australian Telescope, Hectospec's fiber probes are arranged in a radial ``fisherman on the pond'' geometry and held in position with small magnets. A pair of high-speed, six-axis robots move the 300 fiber buttons between observing configurations within ~300 s, and to an accuracy of ~25 μm. The optical fibers run for 26 m between the MMT's focal surface and the bench spectrograph, operating at R~1000-2000. Hectochelle, another high-dispersion bench spectrograph offering R~35,000, is also available. The system throughput, including all losses in the telescope optics, fibers, and spectrograph, peaks at ~10% at the grating blaze in 1" FWHM seeing. Correcting for aperture losses at the 1.5" diameter fiber entrance aperture, the system throughput peaks at ~17%, close to our prediction of 20%. Hectospec has proven to be a workhorse instrument at the MMT. Together, Hectospec and Hectochelle have been scheduled for 1/3 of the available nights since its commissioning. Hectospec has returned approximately 60,000 reduced spectra for 16 scientific programs during its first year of operation.

Optical testbed for the LISA phasemeter

NASA Astrophysics Data System (ADS)

Schwarze, T. S.; Fernández Barranco, G.; Penkert, D.; Gerberding, O.; Heinzel, G.; Danzmann, K.

2016-05-01

The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup.

NEMO educational kit on micro-optics at the secondary school

NASA Astrophysics Data System (ADS)

Flores-Arias, M. T.; Bao-Varela, Carmen

2014-07-01

NEMO was the "Network of Excellence in Micro-Optics" granted in the "Sixth Framework Program" of the European Union. It aimed at providing Europe with a complete Micro-Optics food-chain, by setting up centers for optical modeling and design; measurement and instrumentation; mastering, prototyping and replication; integration and packaging and reliability and standardization. More than 300 researchers from 30 groups in 12 countries participated in the project. One of the objectives of NEMO was to spread excellence and disseminate knowledge on micro-optics and micro-photonics. To convince pupils, already from secondary school level on, about the crucial role of light and micro-optics and the opportunities this combination holds, several partners of NEMO had collaborate to create this Educational Kit. In Spain the partner involved in this aim was the "Microoptics and GRIN Optics Group" at the University of Santiago of Compostela (USC). The educational kits provided to the Secondary School were composed by two plastic cards with the following microoptical element: different kinds of diffractive optical elements or DOES and refractive optical elements or ROEs namely arrays of micro-lenses. The kit also included a DVD with a handbook for performing the experiments as well as a laser pointer source. This kit was distributed free of charge in the countries with partners in NEMO. In particular in Spain was offered to around 200 Secondary School Centers and only 80 answered accepting evaluate the kit.

Programmable CGH on photochromic material using DMD

NASA Astrophysics Data System (ADS)

Alata, Romain; Pariani, Giorgio; Zamkotsian, Frederic; Lanzoni, Patrick; Bianco, Andrea; Bertarelli, Chiara

2016-07-01

Computer Generated Holograms (CGHs) are useful for wavefront shaping and complex optics testing, including aspherical and free-form optics. Today, CGHs are recorded directly with a laser or intermediates masks but allows only recording binary CGHs; binary CGHs are efficient but can reconstruct only pixilated images. We propose to use a Digital Micro-mirror Device (DMD) for writing binary CGHs as well as grayscale CGHs, able to reconstruct fulfilled images. DMD is actually studied at LAM, for generating programmable slit masks in multi-object spectrographs. It is composed of 2048x1080 individually controllable micro-mirrors, with a pitch of 13.68 μm. This is a real-time reconfigurable mask, perfect for recording CGHs. A first setup has been developed for hologram recording, where the DMD is enlightened with a collimated beam and illuminates a photosensible plate through an Offner relay, with a magnification of 1:1. Our set up resolution is 2-3 μm, leading to a CGH resolution equal to the DMD micro mirror size. In order to write and erase CGHs during test procedure or on request, we use a photochromic plate called PUR-GD71-50-ST developed at Politecnico di Milano. It is opaque at rest, and becomes transparent when it is illuminated with visible light, between 500 and 700 nm; then it can be erased by a UV flash. We choose to code the CGHs in equally spaced levels, so called stepped CGH. We recorded up to 1000x1000 pixels CGHs with a contrast greater than 50, knowing that the material is able to reach an ultimate contrast of 1000. A second bench has also been developed, dedicated to the reconstruction of the recorded images with a 632.8nm He-Ne laser beam. Very faithful reconstructions have been obtained. Thanks to our recording and reconstruction set-ups, we have been able to successfully record binary and stepped CGHs, and reconstruct them with a high fidelity, revealing the potential of this method for generating programmable/rewritable stepped CGHs on photochromic materials.

An overhead specimen handling system for variable workloads.

PubMed

Eggert, A A; Bowers, K L; Smulka, G J; Emmerich, K A; Iwanski, A L; Quam, E F

1999-02-01

This unique overhead specimen handling system requires virtually no floor space and only a minimal amount of bench space. It uses state-of-the-art conveyors suspended near the ceiling to transport, log-in and sort blood specimens in standard specimen containers. Specimens placed into the system at bench-level bins are automatically singulated and loaded onto cleated conveyors and lifted to the main conveyor belt near the ceiling. The barcoded labels are then read as the containers are rotated under an optical scanner. The specimens are then diverted to the appropriate branch conveyor and lowered back to the bench level by cleated conveyors. The specimen handling system is rapid and accurate, requires no special containers, allows laboratorians to move unimpeded below it, and is inexpensive by automation standards. Studies show no adverse effect upon the specimens.

Mobbing Experiences of Instructors: Causes, Results, and Solution Suggestions

ERIC Educational Resources Information Center

Celep, Cevat; Konakli, Tugba

2013-01-01

In this study, it was aimed to investigate possible mobbing problems in universities, their causes and results, and to attract attention to precautions that can be taken. Phenomenology as one of the qualitative research methods was used in the study. Sample group of the study was selected through the criteria sampling method and eight instructors…

Relationship between Teachers' Perceptions of Mobbing and Their Problem Solving Skills

ERIC Educational Resources Information Center

Mutlu Gö?men, Nejla; Güle?, Selma

2018-01-01

The purpose of this study is to determine the relationship between classroom teachers' perception of mobbing phenomenon and their problem solving skills. The sample of the study is composed of 208 classroom teachers working in the primary schools in the Osmangazi district of Bursa during the 2013-2014 educational year. The data required for the…

Exposure to Mobbing: Perceptions of Primary School Teachers

ERIC Educational Resources Information Center

Çeliköz, Mine; Çeliköz, Nadir

2017-01-01

The general purpose of the present research is to examine teachers' perceptions of being exposed to Mobbing. The population of the research, in which the screening model is used, consists of teachers working in private and public elementary schools during the 2015-2016 school year. The study group is formed with 305 teachers who were voluntarily…

Mobbing Behaviour: Victims and the Affected

ERIC Educational Resources Information Center

Erturk, Abbas

2013-01-01

The purpose of this research was to identify the level of mobbing behaviour faced by teachers and managers working in primary schools, their responses to such behaviour and the difference in these responses according to the gender variable. The sample of the research consists of a total of 1,316 teachers and managers including 691 men and 625…

The Validity and Reliability of the Mobbing Scale (MS)

ERIC Educational Resources Information Center

Yaman, Erkan

2009-01-01

The aim of this research is to develop the Mobbing Scale and examine its validity and reliability. The sample of the study consisted of 515 persons from Sakarya and Bursa. In this study, construct validity, internal consistency, test-retest reliability, and item analysis of the scale were examined. As a result of factor analysis for construct…

Organizational Trust of Mobbing Victims: A Study of Turkish Teachers

ERIC Educational Resources Information Center

Ertürk, Abbas

2016-01-01

The purpose of this study is to investigate the relationship between mobbing behaviour faced by high schools teachers and their organizational trust. The study was based on the survey model. 418 teachers from five different prefectures in the province of Ankara participated in the survey. The NAQ negative acts scale and organizational trust scale…

What kind of diagnosis in a case of mobbing: post-traumatic stress disorder or adjustment disorder?

PubMed Central

Signorelli, Maria Salvina; Costanzo, Maria Cristina; Cinconze, Maria; Concerto, Carmen

2013-01-01

Over the last decade a consistent increase in stress-related psychological consequences at the workplace, usually called ‘mobbing’, has been seen. It claimed physical, psychical and social distress as its victims, leading to an increased incidence of many illnesses, such as psychosomatic disorders (ache, high blood pressure, chronic fatigue and insomnia) and psychiatric disturbances (high level of anxiety, depression and suicidal attempts). It was recently demonstrated that mobbing is significantly widespread among healthcare workers, especially among female nurses. In this report, we illustrate the case of a nurse who, after a brilliant career, underwent mobbing at the workplace, showing depression, anxiety and sleep disorders that required hospitalisation and a substantial intervention. PMID:23761569

The current development status of the Orbiting Carbon Observatory (OCO) instrument optical design

NASA Technical Reports Server (NTRS)

Haring, Robert; Sutin, Brian; Crisp, David; Pollock, Randy; Sundstrand, Hamilton

2005-01-01

The status of the OCO instrument optical design is presented in this paper. The optical bench assembly comprises three cooled grating spectrometers coupled to an all-reflective telescope/relay system. Dichroic beam splitters are used to separate the light from a common telescope into the three spectral bands. The three bore sighted spectrometers allow the total column CO2 absorption path to be corrected for optical path and surface pressure uncertainties, aerosols, and water vapor. The design of the instrument is based on classic flight proven technologies.

Simple method based on intensity measurements for characterization of aberrations from micro-optical components.

PubMed

Perrin, Stephane; Baranski, Maciej; Froehly, Luc; Albero, Jorge; Passilly, Nicolas; Gorecki, Christophe

2015-11-01

We report a simple method, based on intensity measurements, for the characterization of the wavefront and aberrations produced by micro-optical focusing elements. This method employs the setup presented earlier in [Opt. Express 22, 13202 (2014)] for measurements of the 3D point spread function, on which a basic phase-retrieval algorithm is applied. This combination allows for retrieval of the wavefront generated by the micro-optical element and, in addition, quantification of the optical aberrations through the wavefront decomposition with Zernike polynomials. The optical setup requires only an in-motion imaging system. The technique, adapted for the optimization of micro-optical component fabrication, is demonstrated by characterizing a planoconvex microlens.

Optimization of an Optical Test Bench for Tire Properties Measurement and Tread Defects Characterization

PubMed Central

Castillo Aguilar, Juan Jesús; Cabrera Carrillo, Juan Antonio; Guerra Fernández, Antonio Jesús; Postigo Pozo, Sergio

2017-01-01

Tire characteristics and behavior are of great importance in vehicle dynamics since the forces transmitted in the tire-road contact are the main contributors to global vehicle performance. Several research groups have focused on the study and modeling of tires. Some of the most important factors that need to be known are tread characteristics and pressure distribution in the tire-ground contact patch. In this work, a test bench has been used to adequately determine the aforementioned factors. The measurement principle of the test bench is the frustration of total internal reflection (FTIR) of light. It makes use of a laterally illuminated glass on which the tire leans. An interposed plastic interface between them causes the reflection of light. Finally, a video camera captures the bright image formed through the glass. The brightness level in each pixel of the image is related to existing normal pressure. A study of the parameters that affect the test bench calibration such as type of interface material used, diffuse light, hysteresis, creep and transverse light absorption is performed. Experimental tests are conducted to relate tire inflation pressure and camber angle to the pressure distribution. Furthermore, the test bench is used to detect and evaluate the influence of defects in the tire on the contact pressures. PMID:28353674

Optimization of an Optical Test Bench for Tire Properties Measurement and Tread Defects Characterization.

PubMed

Castillo Aguilar, Juan Jesús; Cabrera Carrillo, Juan Antonio; Guerra Fernández, Antonio Jesús; Postigo Pozo, Sergio

2017-03-29

Tire characteristics and behavior are of great importance in vehicle dynamics since the forces transmitted in the tire-road contact are the main contributors to global vehicle performance. Several research groups have focused on the study and modeling of tires. Some of the most important factors that need to be known are tread characteristics and pressure distribution in the tire-ground contact patch. In this work, a test bench has been used to adequately determine the aforementioned factors. The measurement principle of the test bench is the frustration of total internal reflection (FTIR) of light. It makes use of a laterally illuminated glass on which the tire leans. An interposed plastic interface between them causes the reflection of light. Finally, a video camera captures the bright image formed through the glass. The brightness level in each pixel of the image is related to existing normal pressure. A study of the parameters that affect the test bench calibration such as type of interface material used, diffuse light, hysteresis, creep and transverse light absorption is performed. Experimental tests are conducted to relate tire inflation pressure and camber angle to the pressure distribution. Furthermore, the test bench is used to detect and evaluate the influence of defects in the tire on the contact pressures.

1030-nm diode-laser-based light source delivering pulses with nanojoule energies and picosecond duration adjustable by mode locking or pulse gating operation

NASA Astrophysics Data System (ADS)

Klehr, A.; Liero, A.; Wenzel, H.; Bugge, F.; Brox, O.; Fricke, J.; Ressel, P.; Knigge, A.; Heinrich, W.; Tränkle, G.

2017-02-01

A new compact 1030 nm picosecond light source which can be switched between pulse gating and mode locking operation is presented. It consists of a multi-section distributed Bragg reflector (DBR) laser, an ultrafast multisection optical gate and a flared power amplifier (PA), mounted together with high frequency electronics and optical elements on a 5×4 cm micro bench. The master oscillator (MO) is a 10 mm long ridge wave-guide (RW) laser consisting of 200 μm long saturable absorber, 1500 μm long gain, 8000 μm long cavity, 200 μm long DBR and 100 μm long monitor sections. The 2 mm long optical gate consisting of several RW sections is monolithically integrated with the 4 mm long gain-guided tapered amplifier on a single chip. The light source can be switched between pulse gating and passive mode locking operation. For pulse gating all sections of the MO (except of the DBR and monitor sections) are forward biased and driven by a constant current. By injecting electrical pulses into one section of the optical gate the CW beam emitted by the MO is converted into a train of optical pulses with adjustable widths between 250 ps and 1000 ps. Peak powers of 20 W and spectral linewidths in the MHz range are achieved. Shorter pulses with widths between 4 ps and 15 ps and peak powers up to 50 W but larger spectral widths of about 300 pm are generated by mode locking where the saturable absorber section of the MO is reversed biased. The repetition rate of 4.2 GHz of the pulse train emitted by the MO can be reduced to values between 1 kHz and 100 MHz by utilizing the optical gate as pulse picker. The pulse-to-pulse distance can be controlled by an external trigger source.

Noncontacting-optical-strain device

NASA Technical Reports Server (NTRS)

Silver, R. H.

1970-01-01

Noncontacting-strain-measuring gauge and extensometer remotely measures the mechanical displacement along the entire length of a test specimen. Measurement is accomplished by continuous scanning of a reflected light from reflective bench markings or stripes previously affixed to the specimen.

NASA's Preparations for ESA's L3 Gravitational Wave Mission

NASA Technical Reports Server (NTRS)

Stebbins, Robin

2016-01-01

Telescope Subsystem - Jeff Livas (GSFC): Demonstrate pathlength stability, straylight and manufacturability. Phase Measurement System - Bill Klipstein (JPL): Key measurement functions demonstrated. Incorporate full flight functionality. Laser Subsystem - Jordan Camp (GSFC): ECL master oscillator, phase noise of fiber power amplifier, demonstrate end-to-end performance in integrated system, lifetime. Micronewton Thrusters - John Ziemer (JPL): Propellant storage and distribution, system robustness, manufacturing yield, lifetime. Arm-locking Demonstration - Kirk McKenzie (JPL): Studying a demonstration of laser frequency stabilization with GRACE Follow-On. Torsion Pendulum - John Conklin (UF): Develop U.S. capability with GRS and torsion pendulum test bed. Multi-Axis Heterodyne Interferometry - Ira Thorpe (GSFC): Investigate test mass/optical bench interface. UV LEDs - John Conklin+ (UF): Flight qualify UV LEDs to replace mercury lamps in discharging system. Optical Bench - Guido Mueller (UF): Investigate alternate designs and fabrication processes to ease manufacturability. LISA researchers at JPL are leading the Laser Ranging Interferometer instrument on the GRACE Follow-On mission.

Beam profile measurements for target designators

NASA Astrophysics Data System (ADS)

Frank, J. D.

1985-02-01

An American aerospace company has conducted a number of investigations with the aim to improve on the tedious slow manual methods of measuring pulsed lasers for rangefinders, giving particular attention to beam divergence which is studied by varying aperture sizes and positions in the laser beam path. Three instruments have been developed to make the involved work easier to perform. One of these, the Automatic Laser Instrumentation and Measurement System (ALIMS), consists of an optical bench, a digital computer, and three bays of associated electronic instruments. ALIMS uses the aperture method to measure laser beam alignment and divergence. The Laser Intensity Profile System (LIPS) consists of a covered optical bench and a two bay electronic equipment and control console. The Automatic Laser Test Set (ALTS) utilizes a 50 x 50 silicon photodiode array to characterize military laser systems automatically. Details regarding the conducted determinations are discussed.

Tools for experimental characterization of the non-uniform rotational distortion in intravascular OCT probes

NASA Astrophysics Data System (ADS)

Dufour, Marc L.; Bisaillon, Charles-Etienne; Lamouche, Guy; Vergnole, Sebastien; Hewko, Mark; D'Amours, Frédéric; Padioleau, Christian; Sowa, Michael

2011-03-01

The Industrial Material Institute (IMI) together with the Institute for Biodiagnostic (IBD) has developed its own optical catheters for cardiovascular imaging applications. Those catheters have been used experimentally in the in vitro coronary artery model of the Langendorff beating heart and in a percutaneous coronary intervention procedure in a porcine model. For some catheter designs, non-uniform rotational distortion (NURD) can be observed as expected from past experience with intra-vascular ultrasound (IVUS) catheters. A two-dimensional (2D) coronary artery test bench that simulates the path into the coronary arteries has been developed. The presence or absence of NURD can be assessed with the test bench using a custom-built cardiovascular Optical Coherence Tomography (OCT) imaging system. A square geometry instead of the circular shape of an artery is used to simulate the coronary arteries. Thereby, it is easier to visualize NURD when it is present. The accumulated torsion induced by the friction on the catheter is measured along the artery path. NURD is induced by the varying friction force that is balanced by the accumulated torsion force. The pullback force is measured and correlated with NURD observed in the 2D test bench. Finally, a model is presented to help understanding the mechanical constraint that leads to the friction force variations.

Geospatial Analysis of Low-frequency Radio Signals Collected During the 2017 Solar Eclipse

NASA Astrophysics Data System (ADS)

Liles, W. C.; Nelson, J.; Kerby, K. C.; Lukes, L.; Henry, J.; Oputa, J.; Lemaster, G.

2017-12-01

The total solar eclipse of 2017, with a path that crosses the continental United States, offers a unique opportunity to gather geospatially diverse data. The EclipseMob project has been designed to crowdsource this data by building a network of citizen scientists across the country. The project focuses on gathering low-frequency radio wave data before, during, and after the eclipse. WWVB, a 60 KHz transmitter in Ft. Collins, CO operated by the National Institutes of Standard and Technology, will provide the transmit signal that will be observed by project participants. Participating citizen scientists are building simple antennas and receivers designed by the EclipseMob team and provided to participants in the form of "receiver kits." The EclipseMob receiver downsamples the 60 KHz signal to 18 KHz and supplies the downsampled signal to the audio jack of a smartphone. A dedicated app is used to collect data and upload it to the EclipseMob server. By studying the variations in WWVB amplitude observed during the eclipse at over 150 locations across the country, we aim to understand how the ionization of the D layer of the ionosphere is impacted by the eclipse as a function of both time and space (location). The diverse locations of the EclipseMob participants will provide data from a wide variety of propagation paths - some crossing the path of the total eclipse, and some remaining on the same side of the eclipse path as the transmitter. Our initial data analysis will involve identifying characteristics that define geospatial relationships in the behavior of observed WWVB signal amplitudes.

Recent developments of advanced structures for space optics at Astrium, Germany

NASA Astrophysics Data System (ADS)

Stute, Thomas; Wulz, Georg; Scheulen, Dietmar

2003-12-01

The mechanical division of EADS Astrium GmbH, Friedrichshafen Germany, the former Dornier Satellitensystem GmbH is currently engaged with the development, manufacturing and testing of three different advanced dimensionally stable composite and ceramic material structures for satellite borne optics: -CFRP Camera Structure -Planck Telescope Reflectors -NIRSpec Optical Bench Breadboard for James Web Space Telescope The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

Correlator optical wavefront sensor COWS

NASA Astrophysics Data System (ADS)

1991-02-01

This report documents the significant upgrades and improvements made to the correlator optical wavefront sensor (COWS) optical bench during this phase of the program. Software for the experiment was reviewed and documented. Flowcharts showing the program flow are included as well as documentation for programs which were written to calculate and display Zernike polynomials. The system was calibrated and aligned and a series of experiments to determine the optimum settings for the input and output MOSLM polarizers were conducted. In addition, design of a simple aberration generation is included.

Fourier-transform optical microsystems

NASA Technical Reports Server (NTRS)

Collins, S. D.; Smith, R. L.; Gonzalez, C.; Stewart, K. P.; Hagopian, J. G.; Sirota, J. M.

1999-01-01

The design, fabrication, and initial characterization of a miniature single-pass Fourier-transform spectrometer (FTS) that has an optical bench that measures 1 cm x 5 cm x 10 cm is presented. The FTS is predicated on the classic Michelson interferometer design with a moving mirror. Precision translation of the mirror is accomplished by microfabrication of dovetailed bearing surfaces along single-crystal planes in silicon. Although it is miniaturized, the FTS maintains a relatively high spectral resolution, 0.1 cm-1, with adequate optical throughput.

Photoacoustic microscopy and computed tomography: from bench to bedside

PubMed Central

Wang, Lihong V.; Gao, Liang

2014-01-01

Photoacoustic imaging (PAI) of biological tissue has seen immense growth in the past decade, providing unprecedented spatial resolution and functional information at depths in the optical diffusive regime. PAI uniquely combines the advantages of optical excitation and acoustic detection. The hybrid imaging modality features high sensitivity to optical absorption and wide scalability of spatial resolution with the desired imaging depth. Here we first summarize the fundamental principles underpinning the technology, then highlight its practical implementation, and finally discuss recent advances towards clinical translation. PMID:24905877

Wavefront control system for the Keck telescope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brase, J. M., LLNL

1998-03-01

The laser guide star adaptive optics system currently being developed for the Keck 2 telescope consists of several major subsystems: the optical bench, wavefront control, user interface and supervisory control, and the laser system. The paper describes the design and implementation of the wavefront control subsystem that controls a 349 actuator deformable mirror for high order correction and tip-tilt mirrors for stabilizing the image and laser positions.

Self-assembly micro optical filter

NASA Astrophysics Data System (ADS)

Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.

2006-01-01

Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

Determining the Effects of Mobbing on Organizational Commitment: A Case of Educational Sector in Pakistan

ERIC Educational Resources Information Center

ur Rehman, Fazal; Javed, Farwida; Khan, Aminullah; Nawaz, Tariq; Hyder, Shabir

2015-01-01

Mobbing is an activity where a group of people behave negatively against a person to enforce him/her in an unsecure position to push out of the organization. The study assessed this behavior by collecting data through questionnaires based survey from the employees of universities in Pakistan. Questionnaires were circulated among 400 employees of…

The Investigation of Mobbing Events Taking Place at Higher Education Institutions in Turkey Considering the Reflections on Media

ERIC Educational Resources Information Center

Çubukçu, Zühal; Girmen, Pinar; Dönmez, Ayse

2015-01-01

The business-life related competition established in modern communities has also brought about some other problems. The attacks and intimidation attempts have introduced the term of "mobbing" which is defined as regular and continuous psychological violence faced by people always trying to produce and win from those who they work with.…

The increased risk of predation enhances cooperation

PubMed Central

Krams, Indrikis; Bērziņš, Arnis; Krama, Tatjana; Wheatcroft, David; Igaune, Kristīne; Rantala, Markus J.

2010-01-01

Theory predicts that animals in adverse conditions can decrease individual risks and increase long-term benefits by cooperating with neighbours. However, some empirical studies suggest that animals often focus on short-term benefits, which can reduce the likelihood that they will cooperate with others. In this experimental study, we tested between these two alternatives by evaluating whether increased predation risk (as a correlate of environmental adversity) enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behaviour, among breeding pied flycatchers Ficedula hypoleuca. We tested whether birds would join their mobbing neighbours more often and harass a stuffed predator placed near their neighbours' nests more intensely in areas with a higher perceived risk of predation. Our results show that birds attended mobs initiated by their neighbours more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. In such high-risk areas, birds also were more often involved in between-pair cooperation. This study demonstrates the positive impact of predation risk on cooperation in breeding songbirds, which might help in explaining the emergence and evolution of cooperation. PMID:19846454

Mobbing vocalizations as a coping response in the common marmoset.

PubMed

Cross, N; Rogers, L J

2006-02-01

Using a non-invasive method of sampling saliva followed by assay for cortisol levels, we found that common marmosets (Callithrix jacchus) show a decrease in cortisol levels after seeing a snake-model stimulus that reliably elicits mobbing (tsik) calls. In fact, there was a significant positive correlation between the number of tsik vocalizations made and the magnitude of the decrease in the cortisol concentrations. Furthermore, marmosets with higher levels of cortisol prior to being exposed to the stimulus produce more tsik calls than those with lower levels of cortisol. Subsequent experiments showed that, in response to 15 min of isolation with no visual or auditory contact with conspecifics (a traditional stressor), cortisol levels increased significantly. However, playback of the mobbing calls of a familiar conspecific to individual isolated marmosets not only prevented the rise in cortisol, but also actually caused a decrease in the levels of this hormone. This suggests that the mobbing calls serve to calm the marmoset after experiencing a stressful situation. This finding results in a greater understanding as to the role of physiological responses during communication in this species and could have implications for the welfare of marmosets in captivity.

Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic-Anoxic Interface of the Congo Deep-Sea Fan.

PubMed

Bessette, Sandrine; Moalic, Yann; Gautey, Sébastien; Lesongeur, Françoise; Godfroy, Anne; Toffin, Laurent

2017-01-01

Sitting at ∼5,000 m water depth on the Congo-Angola margin and ∼760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3-5% organic carbon). This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB) communities at the oxic-anoxic interface of sedimentary habitats by using fluorescence in situ hybridization and comparative sequence analysis of particulate mono-oxygenase ( pmoA ) genes. Our findings revealed that sedimentary habitats of the recent lobe complex hosted type I and type II MOB cells and comparisons of pmoA community compositions showed variations among the different organic-rich habitats. Furthermore, the pmoA lineages were taxonomically more diverse compared to methane seep environments and were related to those found at cold seeps. Surprisingly, MOB phylogenetic lineages typical of terrestrial environments were observed at such water depth. In contrast, MOB cells or pmoA sequences were not detected at the previous lobe complex that is disconnected from the Congo River inputs.

MobB protein stimulates nicking at the R1162 origin of transfer by increasing the proportion of complexed plasmid DNA.

PubMed Central

Perwez, T; Meyer, R

1996-01-01

An essential early step in conjugal mobilization of R1162, nicking of the DNA strand that is subsequently transferred, is carried out in the relaxosome, a complex of two plasmid-encoded proteins and DNA at the origin of transfer (oriT). A third protein, MobB, is also required for efficient mobilization. We show that in the cell this protein increases the proportion of molecules specifically nicked at oriT, resulting in lower yields of covalently closed molecules after alkaline extraction. These nicked molecules largely remain supercoiled, with unwinding presumably constrained by the relaxosome. MobB enhances the sensitivity of the oriT DNA to oxidation by permanganate, indicating that the protein acts by increasing the fraction of complexed molecules. Mutations that significantly reduce the amount of complexed DNA in the cell were isolated. However, plasmids with these mutations were mobilized at nearly the normal frequency, were nicked at a commensurate level, and still required MobB. Our results indicate that the frequency of transfer is determined both by the amount of time each molecule is in the nicked form and by the proportion of complexed molecules in the total population. PMID:8824623

Optical Micromachining

NASA Technical Reports Server (NTRS)

1998-01-01

Under an SBIR (Small Business Innovative Research) with Marshall Space Flight Center, Potomac Photonics, Inc., constructed and demonstrated a unique tool that fills a need in the area of diffractive and refractive micro-optics. It is an integrated computer-aided design and computer-aided micro-machining workstation that will extend the benefits of diffractive and micro-optic technology to optical designers. Applications of diffractive optics include sensors and monitoring equipment, analytical instruments, and fiber optic distribution and communication. The company has been making diffractive elements with the system as a commercial service for the last year.

Earth, soil and environmental science research facility at sector 13 of the Advanced Photon Source. II. Scientific program and experimental instrumentation (abstract)

NASA Astrophysics Data System (ADS)

Sutton, S.; Eng., P. J.; Jaski, Y. R.; Lazaraz, N.; Pluth, J.; Murray, P.; Rarback, H.; Rivers, M.

1996-09-01

The GSECARS (APS sector 13) scientific program will provide fundamental new information on the deep structure and composition of the Earth and other planets, the formation of economic mineral deposits, the cycles and fate of toxic metals in the environment, and the mechanisms of nutrient uptake and disease in plants. In the four experimental stations (2 per beamline), scientists will have access to three main x-ray techniques: diffraction (microcrystal, powder, diamond anvil cell, and large volume press), fluorescence microprobe, and spectroscopy (conventional, microbeam, liquid and solid surfaces). The high pressure facilities will be capable of x-ray crystallography at P≳360 GPa and T˜6000 K with the diamond anvil cell and P˜25 GPa and T˜2500 °C with the large volume press. Diffractometers will allow study of 1 micrometer crystals and micro-powders. The microprobe (1 micrometer focused beam) will be capable of chemical analyses in the sub-ppm range using wavelength and energy dispersive detectors. Spectroscopy instrumentation will be available for XANES and EXAFS with microbeams as well as high sensitivity conventional XAS and studies of liquid and solid interfaces. Visiting scientists will be able to setup, calibrate, and test experiments in off-line laboratories with equipment such as micromanipulators, optical microscopes, clean bench, glove boxes, high powered optical and Raman spectrometers.

Rapid prototyping of interfacing microcomponents for printed circuit board-level optical interconnects

NASA Astrophysics Data System (ADS)

Van Erps, Jürgen; Vervaeke, Michael; Thienpont, Hugo

2012-01-01

One of the important challenges for the deployment of the emerging breed of nanotechnology components is interfacing them with the external world, preferably accomplished with low-cost micro-optical devices. For the fabrication of this kind of micro-optical components, we make use of deep proton writing (DPW) as a generic rapid prototyping technology. DPW consists of bombarding polymer samples with swift protons, which results after chemical processing steps in high quality micro-optical components. The strength of the DPW micro-machining technology is the ability to fabricate monolithic building blocks that include micro-optical and mechanical functionalities which can be precisely integrated into more complex photonic systems. In this paper we give an overview of the process steps of the technology and we present several examples of micro-optical and micro-mechanical components, fabricated through DPW, targeting applications in printed circuit baordlevel optical interconnections. These include: high-precision 2-D fiber connectors, discrete out-of-plane coupling structures featuring high-quality 45° and curved micro-mirrors, arrays of high aspect ratio micro-pillars and backplane connectors. While DPW is clearly not a mass fabrication technique as such, one of its assets is that once the master component has been prototyped, a metal mould can be generated from the DPW master by applying electroplating. After removal of the plastic master, this metal mould can be used as a shim in a final microinjection moulding or hot embossing step. This way, the master component can be mass-produced at low cost in a wide variety of high-tech plastics.

Social transmission of a host defense against cuckoo parasitism.

PubMed

Davies, Nicholas B; Welbergen, Justin A

2009-06-05

Coevolutionary arms races between brood parasites and hosts involve genetic adaptations and counter-adaptations. However, hosts sometimes acquire defenses too rapidly to reflect genetic change. Our field experiments show that observation of cuckoo (Cuculus canorus) mobbing by neighbors on adjacent territories induced reed warblers (Acrocephalus scirpaceus) to increase the mobbing of cuckoos but not of parrots (a harmless control) on their own territory. In contrast, observation of neighbors mobbing parrots had no effect on reed warblers' responses to either cuckoos or parrots. These results indicate that social learning provides a mechanism by which hosts rapidly increase their nest defense against brood parasites. Such enemy-specific social transmission enables hosts to track fine-scale spatiotemporal variation in parasitism and may influence the coevolutionary trajectories and population dynamics of brood parasites and hosts.

NASA Tech Briefs, March 2013

NASA Technical Reports Server (NTRS)

2013-01-01

Topics covered include: Remote Data Access with IDL Data Compression Algorithm Architecture for Large Depth-of-Field Particle Image Velocimeters Vectorized Rebinning Algorithm for Fast Data Down-Sampling Display Provides Pilots with Real-Time Sonic-Boom Information Onboard Algorithms for Data Prioritization and Summarization of Aerial Imagery Monitoring and Acquisition Real-time System (MARS) Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End Micro-Textured Black Silicon Wick for Silicon Heat Pipe Array Robust Multivariable Optimization and Performance Simulation for ASIC Design; Castable Amorphous Metal Mirrors and Mirror Assemblies; Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems; Apparatus for Pumping a Fluid; Cobra Fiber-Optic Positioner Upgrade; Improved Wide Operating Temperature Range of Li-Ion Cells; Non-Toxic, Non-Flammable, -80 C Phase Change Materials; Soft-Bake Purification of SWCNTs Produced by Pulsed Laser Vaporization; Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models; Hand-Based Biometric Analysis; The Next Generation of Cold Immersion Dry Suit Design Evolution for Hypothermia Prevention; Integrated Lunar Information Architecture for Decision Support Version 3.0 (ILIADS 3.0); Relay Forward-Link File Management Services (MaROS Phase 2); Two Mechanisms to Avoid Control Conflicts Resulting from Uncoordinated Intent; XTCE GOVSAT Tool Suite 1.0; Determining Temperature Differential to Prevent Hardware Cross-Contamination in a Vacuum Chamber; SequenceL: Automated Parallel Algorithms Derived from CSP-NT Computational Laws; Remote Data Exploration with the Interactive Data Language (IDL); Mixture-Tuned, Clutter Matched Filter for Remote Detection of Subpixel Spectral Signals; Partitioned-Interval Quantum Optical Communications Receiver; and Practical UAV Optical Sensor Bench with Minimal Adjustability.

Local x-ray structure analysis of optically manipulated biological micro-objects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cojoc, Dan; Ferrari, Enrico; Santucci, Silvia C.

2010-12-13

X-ray diffraction using micro- and nanofocused beams is well suited for nanostructure analysis at different sites of a biological micro-object. To conduct in vitro studies without mechanical contact, we developed object manipulation by optical tweezers in a microfluidic cell. Here we report x-ray microdiffraction analysis of a micro-object optically trapped in three dimensions. We revealed the nanostructure of a single starch granule at different points and investigated local radiation damage induced by repeated x-ray exposures at the same position, demonstrating high stability and full control of the granule orientation by multiple optical traps.

Monolithic integrated optic fiber Bragg grating sensor interrogator

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Esterkin, Yan; Kempen, Cornelia; Sun, Songjian

2010-04-01

Fiber Bragg gratings (FBGs) are a mature sensing technology that has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. Fiber Bragg grating sensors can be use for a variety of measurements including strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky, heavy, and costly bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-TransceiverTM) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables the monolithic integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation.

Micro-CT scouting for transmission electron microscopy of human tissue specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morales, A. G.; Stempinski, E. S.; XIAO, X.

Transmission electron microscopy (TEM) provides sub-nanometre-scale details in volumetric samples. Samples such as pathology tissue specimens are often stained with a metal element to enhance contrast, which makes them opaque to optical microscopes. As a result, it can be a lengthy procedure to find the region of interest inside a sample through sectioning. Here, we describe micro-CT scouting for TEM that allows noninvasive identification of regions of interest within a block sample to guide the sectioning step. In a tissue pathology study, a bench-top micro-CT scanner with 10 m resolution was used to determine the location of patches of themore » mucous membrane in osmium-stained human nasal scraping samples. Furthermore, once the regions of interest were located, the sample block was sectioned to expose that location, followed by ultra-thin sectioning and TEM to inspect the internal structure of the cilia of the membrane epithelial cells with nanometre resolution. This method substantially reduced the time and labour of the search process from typically 20 sections for light microscopy to three sections with no added sample preparation. Lay description Electron microscopy provides very high levels of detail in a small area, and thus the question of where to look in an opaque sample, such as a stained tissue specimen, needs to be answered by sectioning the sample in small steps and examining the sections under a light microscope, until the region of interest is found. The search process can be lengthy and labor intensive, especially for a study involving a large number of samples. Small areas of interest can be missed in the process if not enough regions are examined. We also describe a method to directly locate the region of interest within a whole sample using micro-CT imaging, bypassing the need of blindly sectioning. Micro-CT enables locating the region within 3D space; this information provides a guide for sectioning the sample to expose that precise location for high resolution electron microscopy imaging. In a human tissue specimen study, this method considerably reduced the time and labor of the search process.« less

Micro-CT scouting for transmission electron microscopy of human tissue specimens

DOE PAGES

Morales, A. G.; Stempinski, E. S.; XIAO, X.; ...

2016-02-08

Transmission electron microscopy (TEM) provides sub-nanometre-scale details in volumetric samples. Samples such as pathology tissue specimens are often stained with a metal element to enhance contrast, which makes them opaque to optical microscopes. As a result, it can be a lengthy procedure to find the region of interest inside a sample through sectioning. Here, we describe micro-CT scouting for TEM that allows noninvasive identification of regions of interest within a block sample to guide the sectioning step. In a tissue pathology study, a bench-top micro-CT scanner with 10 m resolution was used to determine the location of patches of themore » mucous membrane in osmium-stained human nasal scraping samples. Furthermore, once the regions of interest were located, the sample block was sectioned to expose that location, followed by ultra-thin sectioning and TEM to inspect the internal structure of the cilia of the membrane epithelial cells with nanometre resolution. This method substantially reduced the time and labour of the search process from typically 20 sections for light microscopy to three sections with no added sample preparation. Lay description Electron microscopy provides very high levels of detail in a small area, and thus the question of where to look in an opaque sample, such as a stained tissue specimen, needs to be answered by sectioning the sample in small steps and examining the sections under a light microscope, until the region of interest is found. The search process can be lengthy and labor intensive, especially for a study involving a large number of samples. Small areas of interest can be missed in the process if not enough regions are examined. We also describe a method to directly locate the region of interest within a whole sample using micro-CT imaging, bypassing the need of blindly sectioning. Micro-CT enables locating the region within 3D space; this information provides a guide for sectioning the sample to expose that precise location for high resolution electron microscopy imaging. In a human tissue specimen study, this method considerably reduced the time and labor of the search process.« less

Study on micro-bend light transmission performance of novel liquid-core optical fiber

NASA Astrophysics Data System (ADS)

Ma, Junyan; Zhao, Zhimin; Wang, Kaisheng; Guo, Linfeng

2007-01-01

With the increasing development of material technology and electronic integration technology, optical fiber and its using in smart structure have become hot in the field of material research. And liquid-core optical fiber is a special kind of optical fiber, which is made using liquid material as core and polymer material as optical layer and protective covering, and it has the characteristics of large core diameter, high numerical aperture, large-scope and efficient spectrum transmission and long life for using. So the liquid-core optical fiber is very suitable for spectrum cure, ultraviolet solidification, fluorescence detection, criminal investigation and evidence obtainment, etc, and especially as light transfer element in some new structures for the measurement of some signals, such as concentration, voltage, temperature, light intensity and so on. In this paper, the novel liquid-core optical fiber is self-made, and then through the test of its light transmission performance in free state, the relation between axial micro-bend and light-intensity loss are presented. When the liquid-core optical fiber is micro-bent axially, along with the axial displacement's increase, output power of light is reducing increasingly, and approximately has linear relation to micro-displacement in a range. According to the results liquid-core fiber-optic micro-bend sensor can be designed to measure micro-displacement of the tested objects. Experimental data and analysis provide experimental basis for further application of liquid-core optical fiber.

Measuring Mobility Limitations in Children with Cerebral Palsy: Content and Construct Validity of a Mobility Questionnaire (MobQues)

ERIC Educational Resources Information Center

Van Ravesteyn, Nicolien T.; Scholtes, Vanessa A.; Becher, Jules G.; Roorda, Leo D.; Verschuren, Olaf; Dallmeijer, Annet J.

2010-01-01

Aim: The objective of this study was to assess the validity of a mobility questionnaire (MobQues) that was developed to measure parent-reported mobility limitations in children with cerebral palsy (CP). Method: The parents of 439 children with CP (256 males and 183 females; age range 2-18y; Gross Motor Function Classification System [GMFCS] levels…

Lake size and water-column stability affect the importance of methane for pelagic food webs of boreal lakes

NASA Astrophysics Data System (ADS)

Kankaala, Paula; Lopez-Bellido, Jessica; Ojala, Anne; Tulonen, Tiina; Jones, Roger I.

2013-04-01

Physical forcing, related to lake size and morphometry, plays an important role in the landscape-scale biogeochemical processing and fluxes of terrestrial carbon in lakes. Boreal lakes are typically dimictic, with mixing of the water column in spring and autumn, but in small, sheltered, humic, forest lakes the spring mixing is often incomplete. This leads to a steep summer stratification and oxygen depletion in the hypolimnion of the lakes. As a result of anaerobic decomposition of organic matter, high concentrations of CH4are typical in these lakes. At the oxic-anoxic interface zone methanotrophic microbes oxidize CH4 to CO2 and partly incorporate CH4-C into microbial biomass, and thus potentially provide a diet source for pelagic consumers. We studied production at the base of the pelagic food web by methane oxidising bacteria (MOB), heterotrophic bacteria (HB) and phytoplankton (PP) in five boreal lakes with a dissolved organic carbon (DOC) concentration varying between 7 and 25 mg C L-1 and an area ranging from 0.004 to 13.4 km2. High MOB activity was detected in the water columns of the three smallest lakes having anoxia in the hypolimnion during summer. The highest MOB activities (ca. 2-12 μmol L-1 d-1) were observed when the CH4:O2 ratio varied between ca. 0.5-12. Seasonally, the highest MOB activities were measured during late-summer mixed layer deepening and autumnal mixing of the whole water column. The proportion of MOB in the total basal production was highest in the two smallest lakes (24-56 and 13-36%), having the steepest summertime stratification. The proportion MOB in the basal production decreased with lake size being 70% of basal production was by PP. In all studied lakes HB contributed only 10-23% of the total basal production, suggesting that a transfer of allochthonous DOC via HB plays only a modest role for the nutrition of the higher trophic levels.

Towards the LISA backlink: experiment design for comparing optical phase reference distribution systems

NASA Astrophysics Data System (ADS)

Isleif, Katharina-Sophie; Bischof, Lea; Ast, Stefan; Penkert, Daniel; Schwarze, Thomas S.; Fernández Barranco, Germán; Zwetz, Max; Veith, Sonja; Hennig, Jan-Simon; Tröbs, Michael; Reiche, Jens; Gerberding, Oliver; Danzmann, Karsten; Heinzel, Gerhard

2018-04-01

LISA is a proposed space-based laser interferometer detecting gravitational waves by measuring distances between free-floating test masses housed in three satellites in a triangular constellation with laser links in-between. Each satellite contains two optical benches that are articulated by moving optical subassemblies for compensating the breathing angle in the constellation. The phase reference distribution system, also known as backlink, forms an optical bi-directional path between the intra-satellite benches. In this work we discuss phase reference implementations with a target non-reciprocity of at most 2π μrad \\sqrtHz-1 , equivalent to 1 pm \\sqrtHz-1 for a wavelength of 1064 nm in the frequency band from 0.1 mHz to 1 Hz. One phase reference uses a steered free beam connection, the other one a fiber together with additional laser frequencies. The noise characteristics of these implementations will be compared in a single interferometric set-up with a previously successfully tested direct fiber connection. We show the design of this interferometer created by optical simulations including ghost beam analysis, component alignment and noise estimation. First experimental results of a free beam laser link between two optical set-ups that are co-rotating by  ±1° are presented. This experiment demonstrates sufficient thermal stability during rotation of less than 10‑4 K \\sqrtHz-1 at 1 mHz and operation of the free beam steering mirror control over more than 1 week.

High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array

DOEpatents

Freitas, Barry L.

1998-01-01

An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver>4kW/cm2 of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources.

Analysis of creating an innovative micro-lens made of polydimethylsiloxane polymer on the end of the optical fibers

NASA Astrophysics Data System (ADS)

Zboril, O.; Cubik, J.; Nedoma, J.; Fajkus, M.; Novak, M.; Jargus, J.; Stratil, T.; Vasinek, V.

2017-10-01

The article describes a method for fabrication of polymer optical micro-lenses using polydimethylsiloxane (PDMS) at the end of optical fibers. PDMS is an optically clear substance having a refractive index very similar to the optical fibers. Therefore it is an interesting material for optical purposes. PDMS is characterized by resistance to electromagnetic interference (EMI), enabling the use in electromagnetically noisy environments. These lenses could be used for example for the security applications. For the manufacture of the micro-lenses is used Sylgard silicone elastomer 184. When applied to the end of conventional optical fiber is cured by treatment at 100 °C +/- 5 °C. Authors performed a series of experimental measurements. The optical characteristics of the treated fibers compared with conventional fibers without micro-lenses. The fibers provided with optical lenses made of PDMS may be used for security applications, in the visible light communication (VLC) or as a microprobe.

High Efficiency Coupling of Optical Fibres with SU8 Micro-droplet Using Laser Welding Process

NASA Astrophysics Data System (ADS)

Yardi, Seema; Gupta, Ankur; Sundriyal, Poonam; Bhatt, Geeta; Kant, Rishi; Boolchandani, D.; Bhattacharya, Shantanu

2016-09-01

Apart from micro- structure fabrication, ablation, lithography etc., lasers find a lot of utility in various areas like precision joining, device fabrication, local heat delivery for surface texturing and local change of microstructure fabrication of standalone optical micro-devices (like microspheres, micro-prisms, micro-scale ring resonators, optical switches etc). There is a wide utility of such systems in chemical/ biochemical diagnostics and also communications where the standalone optical devices exist at a commercial scale but chip based devices with printed optics are necessary due to coupling issues between printed structures and external optics. This paper demonstrates a novel fabrication strategy used to join standalone optical fibres to microchip based printed optics using a simple SU8 drop. The fabrication process is deployed for fiber to fiber optical coupling and coupling between fiber and printed SU-8 waveguides. A CO2 laser is used to locally heat the coupling made up of SU8 material. Optimization of various dimensional parameters using design of experiments (DOE) on the bonded assembly has been performed as a function of laser power, speed, cycle control, spot size so on so forth. Exclusive optical [RF] modelling has been performed to estimate the transmissibility of the optical fibers bonded to each other on a surface with SU8. Our studies indicate the formation of a Whispering gallery mode (WGM) across the micro-droplet leading to high transmissibility of the signal. Through this work we have thus been able to develop a method of fabrication for optical coupling of standalone fibers or coupling of on-chip optics with off-chip illumination/detection.

A Toolbox of Metrology-Based Techniques for Optical System Alignment

NASA Technical Reports Server (NTRS)

Coulter, Phillip; Ohl, Raymond G.; Blake, Peter N.; Bos, Brent J.; Casto, Gordon V.; Eichhorn, William L.; Gum, Jeffrey S.; Hadjimichael, Theodore J.; Hagopian, John G.; Hayden, Joseph E.;

A Toolbox of Metrology-Based Techniques for Optical System Alignment

NASA Technical Reports Server (NTRS)

Coulter, Phillip; Ohl, Raymond G.; Blake, Peter N.; Bos, Brent J.; Eichhorn, William L.; Gum, Jeffrey S.; Hadjimichael, Theodore J.; Hagopian, John G.; Hayden, Joseph E.; Hetherington, Samuel E.;

Microfabricated endoscopic probe integrated MEMS micromirror for optical coherence tomography bioimaging.

PubMed

Wang, Ming-Fang; Xu, Yingshun; Prem, C S; Chen, Kelvin Wei Sheng; Xie, Jin; Mu, Xiaojing; Tan, Chee Wei; Yu, Aibin; Feng, Hanhua

2010-01-01

In this paper, we present a miniaturized endoscopic probe, consisted of MEMS micromirror, silicon optical bench (SiOB), grade index (GRIN) lens, single mode optical fiber (SMF) and transparent housing, for optical coherence tomography (OCT) bioimaging. Due to the use of the MEMS micromirror, the endoscopic OCT system is highly suitable for non-invasive imaging diagnosis of a wide variety of inner organs. The probe engineering and proof of concept were demonstrated by obtaining the two-dimensional OCT images with a cover slide and an onion used as standard samples and the axial resolution was around 10µm.

XAFS and Protein Crystallography Beamline BL38B1 at SPring-8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanida, Hajime; Miura, Keiko; Takeshita, Kunikazu

2004-05-12

The SPring-8 bending magnet beamline BL38B1 is designed for R and D of optics, detectors, experiments for XAFS and protein X-ray crystallography (PX). This beamline has a multi-purpose hutch for two experimental stations of XAFS and PX, and removable optical benches used for R and D of detectors and instruments. The design and the performance of the beamline are presented.

Development of large aperture telescope technology (LATT): test results on a demonstrator bread-board

NASA Astrophysics Data System (ADS)

Briguglio, R.; Xompero, M.; Riccardi, A.; Lisi, F.; Duò, F.; Vettore, C.; Gallieni, D.; Tintori, M.; Lazzarini, P.; Patauner, C.; Biasi, R.; D'Amato, F.; Pucci, M.; Pereira do Carmo, João.

2017-11-01

The concept of a low areal density primary mirror, actively controlled by actuators, has been investigated through a demonstration prototype. A spherical mirror (400 mm diameter, 2.7 Kg mass) has been manufactured and tested in laboratory and on the optical bench, to verify performance, controllability and optical quality. In the present paper we will describe the prototype and the test results.

Ion projection lithography: November 2000 status and sub-70-nm prospects

NASA Astrophysics Data System (ADS)

Kaesmaier, Rainer; Wolter, Andreas; Loeschner, Hans; Schunck, Stefan

2000-10-01

Among all next generation lithography (NGL) options Ion Projection Lithography (IPL) offers the smallest (particle) wavelength of 5x10- 5nm (l00keV Helium ions). Thus, 4x reduction ion-optics has diffraction limits <3nm even when using a numerical aperture as low as NAequals10-5. As part of the European MEDEA IPL project headed by Infineon Technologies wide field ion-optics have been designed by IMS- Vienna with predicted resolution of 50nm within a 12.5mm exposure field. The ion-optics part of the PDT tool (PDT-IOS) has been realized and assembled. In parallel to the PDT-IOS effort, at Leica Jena a test bench for a vertical vacuum 300mm-wafer stage has been realized. Operation of magnetic bearing supported stage movement has already been demonstrated. As ASML vacuum compatible optical wafer alignment system, with 3nm(3(sigma) ) precision demonstrated in air, has been integrated to this wafer test bench system recently. Parallel to the IPL tool development, Infineon Technologies Mask House and the Institute for Microelectronics Stuttgart are intensively working on the development of IPL stencil masks with success in producing 150mm and 200mm stencil masks as reported elsewhere. This paper is focused on information about the status of the PDT-IOS tool.

Biology Division Habrobracon Experiment P-1079

NASA Technical Reports Server (NTRS)

1968-01-01

Dosimetric analyses accumulated during the five-year period of the biosatellite program are summarized. These data are from a unique source placed in a unique optical bench, the biosatellite. Thus the multitudinous array of dosimeters was mandatory to give confidence in the experiment.

Changes in the serotonergic system and in brain-derived neurotrophic factor distribution in the main olfactory bulb of pcd mice before and after mitral cell loss.

PubMed

Gómez, C; Curto, G G; Baltanás, F C; Valero, J; O'Shea, E; Colado, M I; Díaz, D; Weruaga, E; Alonso, J R

2012-01-10

The serotonergic centrifugal system innervating the main olfactory bulb (MOB) plays a key role in the modulation of olfactory processing. We have previously demonstrated that this system suffers adaptive changes under conditions of a lack of olfactory input. The present work examines the response of this centrifugal system after mitral cell loss in the Purkinje cell degeneration (pcd) mutant mice. The distribution and density of serotonergic centrifugal axons were studied in the MOB of control and pcd mice, both before and after the loss of mitral cells, using serotonin (5-HT) and 5-HT transporter immunohistochemistry. Studies of the amount of 5-HT and its metabolite, 5-hydroxyindole acetic acid (5-HIAA), were performed by means of high-performance liquid chromatography (HPLC), and the relative amounts of brain-derived neurotrophin factor, BDNF, and its major receptor, tropomyosin-related kinase B (TrkB), were measured by Western blot. Our study revealed that the serotonergic system develops adaptive changes after, but not before, mitral cell loss. The lack of the main bulbar projection cells causes a decrease in the serotonergic input received by the MOB, whereas the number of serotonergic cells in the raphe nuclei remains constant. In addition, one of the molecules directly involved in serotonergic sprouting, the neurotrophin BDNF and its main receptor TrkB, underwent alterations in the MOBs of the pcd animals even before the loss of mitral cells. These data indicate that serotonergic function in the MOB is closely related to olfactory activity and that mitral cell loss induces serotonergic plastic responses. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Low-cost, high-precision micro-lensed optical fiber providing deep-micrometer to deep-nanometer-level light focusing.

PubMed

Wen, Sy-Bor; Sundaram, Vijay M; McBride, Daniel; Yang, Yu

2016-04-15

A new type of micro-lensed optical fiber through stacking appropriate high-refractive microspheres at designed locations with respect to the cleaved end of an optical fiber is numerically and experimentally demonstrated. This new type of micro-lensed optical fiber can be precisely constructed with low cost and high speed. Deep micrometer-scale and submicrometer-scale far-field light spots can be achieved when the optical fibers are multimode and single mode, respectively. By placing an appropriate teardrop dielectric nanoscale scatterer at the far-field spot of this new type of micro-lensed optical fiber, a deep-nanometer near-field spot can also be generated with high intensity and minimum joule heating, which is valuable in high-speed, high-resolution, and high-power nanoscale detection compared with traditional near-field optical fibers containing a significant portion of metallic material.

Micro guidance and control synthesis: New components, architectures, and capabilities

NASA Technical Reports Server (NTRS)

Mettler, Edward; Hadaegh, Fred Y.

1993-01-01

New GN&C (guidance, navigation and control) system capabilities are shown to arise from component innovations that involve the synergistic use of microminiature sensors and actuators, microelectronics, and fiber optics. Micro-GN&C system and component concepts are defined that include micro-actuated adaptive optics, micromachined inertial sensors, fiber-optic data nets and light-power transmission, and VLSI microcomputers. The thesis is advanced that these micro-miniaturization products are capable of having a revolutionary impact on space missions and systems, and that GN&C is the pathfinder micro-technology application that can bring that about.

Fabrication of an Optical Fiber Micro-Sphere with a Diameter of Several Tens of Micrometers.

PubMed

Yu, Huijuan; Huang, Qiangxian; Zhao, Jian

2014-06-25

A new method to fabricate an integrated optical fiber micro-sphere with a diameter within 100 µm, based on the optical fiber tapering technique and the Taguchi method is proposed. Using a 125 µm diameter single-mode (SM) optical fiber, an optical fiber taper with a cone angle is formed with the tapering technique, and the fabrication optimization of a micro-sphere with a diameter of less than 100 µm is achieved using the Taguchi method. The optimum combination of process factors levels is obtained, and the signal-to-noise ratio (SNR) of three quality evaluation parameters and the significance of each process factors influencing them are selected as the two standards. Using the minimum zone method (MZM) to evaluate the quality of the fabricated optical fiber micro-sphere, a three-dimensional (3D) numerical fitting image of its surface profile and the true sphericity are subsequently realized. From the results, an optical fiber micro-sphere with a two-dimensional (2D) diameter less than 80 µm, 2D roundness error less than 0.70 µm, 2D offset distance between the micro-sphere center and the fiber stylus central line less than 0.65 µm, and true sphericity of about 0.5 µm, is fabricated.

High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array

DOEpatents

Freitas, B.L.

1998-10-27

An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver > 4kW/cm{sup 2} of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources. 13 figs.

Optical assembly of bio-hybrid micro-robots.

PubMed

Barroso, Álvaro; Landwerth, Shirin; Woerdemann, Mike; Alpmann, Christina; Buscher, Tim; Becker, Maike; Studer, Armido; Denz, Cornelia

2015-04-01

The combination of micro synthetic structures with bacterial flagella motors represents an actual trend for the construction of self-propelled micro-robots. The development of methods for fabrication of these bacteria-based robots is a first crucial step towards the realization of functional miniature and autonomous moving robots. We present a novel scheme based on optical trapping to fabricate living micro-robots. By using holographic optical tweezers that allow three-dimensional manipulation in real time, we are able to arrange the building blocks that constitute the micro-robot in a defined way. We demonstrate exemplarily that our method enables the controlled assembly of living micro-robots consisting of a rod-shaped prokaryotic bacterium and a single elongated zeolite L crystal, which are used as model of the biological and abiotic components, respectively. We present different proof-of-principle approaches for the site-selective attachment of the bacteria on the particle surface. The propulsion of the optically assembled micro-robot demonstrates the potential of the proposed method as a powerful strategy for the fabrication of bio-hybrid micro-robots.

Optical bench performance of a novel trifocal intraocular lens compared with a multifocal intraocular lens

PubMed Central

Lee, Shinwook; Choi, Myoung; Xu, Zaiwei; Zhao, Zeyu; Alexander, Elsinore; Liu, Yueai

2016-01-01

Purpose The purpose of this study is to compare the optical characteristics of the novel PanOptix presbyopia-correcting trifocal intraocular lens (IOL) and the multifocal ReSTOR +3.0 D IOL, through in vitro bench investigations. Methods The optical characteristics of AcrySof® IQ PanOptix™ (PanOptix) and AcrySof® IQ ReSTOR +3.0 D (ReSTOR +3.0 D) IOLs were evaluated by through-focus Badal images, simulated headlight images, and modulation transfer function (MTF) measurements which determine resolution, photic phenomena, and image quality. Through-focus Badal images of an Early Treatment of Diabetic Retinopathy Study chart were recorded at both photopic and mesopic pupil sizes. Simulated headlight images were taken on an MTF bench with a 50-μm pinhole target and a 5.0 mm pupil at the distance focus of the IOL. MTF curves were measured with a 3.0 mm pupil, and spatial frequencies equivalent to 20/40 and 20/20 visual acuities were recorded to illustrate the through-focus MTF curves. Far-, intermediate-, and near-focus MTF values were obtained. Results Bench Badal image testing and MTF measurements showed that PanOptix has a near focus at a distance of 42 cm and an additional intermediate focus at a distance of about 60 cm. The near focus for ReSTOR +3.0 D is at 45 cm. PanOptix and ReSTOR +3.0 D have comparable photopic distances and near MTF values. Additionally, PanOptix provided a substantial continuous range of vision from distance to intermediate and to near compared with ReSTOR +3.0 D. The halo propensity for PanOptix was slightly higher than that for ReSTOR +3.0 D. Conclusion Laboratory-based in vitro simulations showed that PanOptix trifocal IOL has comparable resolution and image quality performance in distance and near foci compared with ReSTOR +3.0 D IOL. PanOptix showed better resolution and image quality performance at the intermediate focus than ReSTOR +3.0 D IOL. PMID:27330273

Eye vision system using programmable micro-optics and micro-electronics

NASA Astrophysics Data System (ADS)

Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.

2014-02-01

Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

The application of micro-lesson in optics teaching

NASA Astrophysics Data System (ADS)

Yuan, Suzhen; Mao, Xuefeng; Lu, Yongle; Wang, Yan; Luo, Yuan

2017-08-01

In order to improve students' ability on self-study, this paper discusses the application of micro-lesson as a supplementary way in the course of optics teaching. Both geometric optics and wave optics require a lot of demos, fortunately, micro-lesson just meets this requirement. Nowadays, college education focuses on quality education, so the new nurture scheme of most universities shortened the class hours. However, the development of students and the social needs also require students to have a solid foundation. The effective way to solve this contradiction is to improve the efficiency of classroom teaching and provide the repeatable learning form, micro-lesson.

Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry.

PubMed

Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

2017-02-25

In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time.

Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry

PubMed Central

Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

2017-01-01

In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time. PMID:28245603

Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic–Anoxic Interface of the Congo Deep-Sea Fan

PubMed Central

Bessette, Sandrine; Moalic, Yann; Gautey, Sébastien; Lesongeur, Françoise; Godfroy, Anne; Toffin, Laurent

2017-01-01

Sitting at ∼5,000 m water depth on the Congo-Angola margin and ∼760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3–5% organic carbon). This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB) communities at the oxic–anoxic interface of sedimentary habitats by using fluorescence in situ hybridization and comparative sequence analysis of particulate mono-oxygenase (pmoA) genes. Our findings revealed that sedimentary habitats of the recent lobe complex hosted type I and type II MOB cells and comparisons of pmoA community compositions showed variations among the different organic-rich habitats. Furthermore, the pmoA lineages were taxonomically more diverse compared to methane seep environments and were related to those found at cold seeps. Surprisingly, MOB phylogenetic lineages typical of terrestrial environments were observed at such water depth. In contrast, MOB cells or pmoA sequences were not detected at the previous lobe complex that is disconnected from the Congo River inputs. PMID:28487684

A novel surface-enhanced Raman scattering (SERS) detection for natural gas exploration using methane-oxidizing bacteria.

PubMed

Liang, Weiwei; Chen, Qiao; Peng, Fang; Shen, Aiguo; Hu, Jiming

2018-07-01

Methane-oxidizing bacteria (MOB), a unique group of Gram-negative bacteria utilizing methane as a sole source of carbon and energy, have been proved to be a biological indicator for gas prospecting. Field and cultivation-free detection of MOB is important but still challenging in current microbial prospecting of oil and gas (MPOG) system. Herein, SERS was used for the first time to our knowledge to investigate two species of methanotrophs and four closely relevant bacteria that universally coexisted in the upper soil of natural gas. A special but very simple approach was utilized to make silver nanoparticles (Ag NPs) sufficiently contact with every single bacterial cell, and highly strong and distinct Raman signals free from any native fluorescence have been obtained, and successfully utilized for distinguishing MOB from other species. A more convincing multi-Raman criterion based on single Raman bands, and further the entire Raman spectrum in combination with statistical analysis (e.g., principal component analysis (PCA)), which were found capable of classifying MOB related bacterial cells in soil with an accuracy of 100%. This study therefore demonstrated sensitive and rapid SERS measurement technique accompanied by complete Raman database of various gas reservoirs related bacteria could aid field exploration of natural gas reservoir. Copyright © 2018 Elsevier B.V. All rights reserved.

Microbial minorities modulate methane consumption through niche partitioning

PubMed Central

Bodelier, Paul LE; Meima-Franke, Marion; Hordijk, Cornelis A; Steenbergh, Anne K; Hefting, Mariet M; Bodrossy, Levente; von Bergen, Martin; Seifert, Jana

2013-01-01

Microbes catalyze all major geochemical cycles on earth. However, the role of microbial traits and community composition in biogeochemical cycles is still poorly understood mainly due to the inability to assess the community members that are actually performing biogeochemical conversions in complex environmental samples. Here we applied a polyphasic approach to assess the role of microbial community composition in modulating methane emission from a riparian floodplain. We show that the dynamics and intensity of methane consumption in riparian wetlands coincide with relative abundance and activity of specific subgroups of methane-oxidizing bacteria (MOB), which can be considered as a minor component of the microbial community in this ecosystem. Microarray-based community composition analyses demonstrated linear relationships of MOB diversity parameters and in vitro methane consumption. Incubations using intact cores in combination with stable isotope labeling of lipids and proteins corroborated the correlative evidence from in vitro incubations demonstrating γ-proteobacterial MOB subgroups to be responsible for methane oxidation. The results obtained within the riparian flooding gradient collectively demonstrate that niche partitioning of MOB within a community comprised of a very limited amount of active species modulates methane consumption and emission from this wetland. The implications of the results obtained for biodiversity–ecosystem functioning are discussed with special reference to the role of spatial and temporal heterogeneity and functional redundancy. PMID:23788331

Activation of β-noradrenergic receptors enhances rhythmic bursting in mouse olfactory bulb external tufted cells.

PubMed

Zhou, Fu-Wen; Dong, Hong-Wei; Ennis, Matthew

2016-12-01

The main olfactory bulb (MOB) receives a rich noradrenergic innervation from the nucleus locus coeruleus. Despite the well-documented role of norepinephrine and β-adrenergic receptors in neonatal odor preference learning, identified cellular physiological actions of β-receptors in the MOB have remained elusive. β-Receptors are expressed at relatively high levels in the MOB glomeruli, the location of external tufted (ET) cells that exert an excitatory drive on mitral and other cell types. The present study investigated the effects of β-receptor activation on the excitability of ET cells with patch-clamp electrophysiology in mature mouse MOB slices. Isoproterenol and selective β 2 -, but not β 1 -, receptor agonists were found to enhance two key intrinsic currents involved in ET burst initiation: persistent sodium (I NaP ) and hyperpolarization-activated inward (I h ) currents. Together, the positive modulation of these currents increased the frequency and strength of ET cell rhythmic bursting. Rodent sniff frequency and locus coeruleus neuronal firing increase in response to novel stimuli or environments. The increase in ET excitability by β-receptor activation may better enable ET cell rhythmic bursting, and hence glomerular network activity, to pace faster sniff rates during heightened norepinephrine release associated with arousal. Copyright © 2016 the American Physiological Society.

Naive Juveniles Are More Likely to Become Breeders after Witnessing Predator Mobbing.

PubMed

Griesser, Michael; Suzuki, Toshitaka N

2017-01-01

Responding appropriately during the first predatory attack in life is often critical for survival. In many social species, naive juveniles acquire this skill from conspecifics, but its fitness consequences remain virtually unknown. Here we experimentally demonstrate how naive juvenile Siberian jays (Perisoreus infaustus) derive a long-term fitness benefit from witnessing knowledgeable adults mobbing their principal predator, the goshawk (Accipiter gentilis). Siberian jays live in family groups of two to six individuals that also can include unrelated nonbreeders. Field observations showed that Siberian jays encounter predators only rarely, and, indeed, naive juveniles do not respond to predator models when on their own but do when observing other individuals mobbing them. Predator exposure experiments demonstrated that naive juveniles had a substantially higher first-winter survival after observing knowledgeable group members mobbing a goshawk model, increasing their likelihood of acquiring a breeding position later in life. Previous research showed that naive individuals may learn from others how to respond to predators, care for offspring, or choose mates, generally assuming that social learning has long-term fitness consequences without empirical evidence. Our results demonstrate a long-term fitness benefit of vertical social learning for naive individuals in the wild, emphasizing its evolutionary importance in animals, including humans.

Selection of associated heterotrophs by methane-oxidizing bacteria at different copper concentrations.

PubMed

van der Ha, David; Vanwonterghem, Inka; Hoefman, Sven; De Vos, Paul; Boon, Nico

2013-03-01

Due to the increasing atmospheric concentration of the greenhouse gas methane, more knowledge is needed on the management of methanotrophic communities. While most studies have focused on the characteristics of the methane-oxidizing bacteria (MOB), less is known about their interactions with the associated heterotrophs. Interpretative tools based on denaturing gradient gel electrophoresis allowed to evaluate the influence of copper-an important enzymatic regulator for MOB-on the activity and composition of the bacterial community. Over 30 days, enrichments with 0.1, 1.0 and 10 μM Cu(2+) respectively, showed comparable methane oxidation activities. The different copper concentrations did not create major shifts in the methanotrophic communities, as a Methylomonas sp. was able to establish dominance at all different copper concentrations by switching between both known methane monooxygenases. The associated heterotrophic communities showed continuous shifts, but over time all cultures evolved to a comparable composition, independent of the copper concentration. This indicates that the MOB selected for certain heterotrophs, possibly fulfilling vital processes such as removal of toxic compounds. The presence of a large heterotrophic food web indirectly depending on methane as sole carbon and energy source was confirmed by a clone library wherein MOB only formed a minority of the identified species.

Mobbing in Bosnia and Herzegovina and the member states of the European Union

NASA Astrophysics Data System (ADS)

Rodic, V.

2016-08-01

Mobbing as a specific form of discrimination which applies only to the labor law, is a very young branch of labor law. It began to develop during the eighties of last century. This kind of psychoterror that appears in the workplace, was first spotted, formulated and diagnosed by the Swedish psychologist of German origin prof. Dr. Heinz Lejman (Heinz Leymann July 17, 1932.; Wolfenbuttel, Germany - 1999 Stockholm, Sweden). Today, the legal regulation of mobbing in terms of prevention, rules of behavior and sanctions is indispensable to every modern democratic state. I'll make a comparison of the legislative regulation provided by BiH with several European Union member states. I will compare the results of a survey conducted by the European Foundation for the Improvement of Living and Working Condition, during the year 2000. In the European Union Member States, with the results of the questionnaire for employees, which I conducted in Bosnia and Herzegovina. The conclusion I came to in this paper is: Bosnia and Herzegovina is lagging behind a lot of European Union member states, both in terms of prevention of mobbing, as well as legislation, that is insufficient to regulate this complex issue. Results of the questionnaire for the employees that I conducted in Bosnia and Herzegovina are devastating and alarming.

Microbial minorities modulate methane consumption through niche partitioning.

PubMed

Bodelier, Paul L E; Meima-Franke, Marion; Hordijk, Cornelis A; Steenbergh, Anne K; Hefting, Mariet M; Bodrossy, Levente; von Bergen, Martin; Seifert, Jana

2013-11-01

Microbes catalyze all major geochemical cycles on earth. However, the role of microbial traits and community composition in biogeochemical cycles is still poorly understood mainly due to the inability to assess the community members that are actually performing biogeochemical conversions in complex environmental samples. Here we applied a polyphasic approach to assess the role of microbial community composition in modulating methane emission from a riparian floodplain. We show that the dynamics and intensity of methane consumption in riparian wetlands coincide with relative abundance and activity of specific subgroups of methane-oxidizing bacteria (MOB), which can be considered as a minor component of the microbial community in this ecosystem. Microarray-based community composition analyses demonstrated linear relationships of MOB diversity parameters and in vitro methane consumption. Incubations using intact cores in combination with stable isotope labeling of lipids and proteins corroborated the correlative evidence from in vitro incubations demonstrating γ-proteobacterial MOB subgroups to be responsible for methane oxidation. The results obtained within the riparian flooding gradient collectively demonstrate that niche partitioning of MOB within a community comprised of a very limited amount of active species modulates methane consumption and emission from this wetland. The implications of the results obtained for biodiversity-ecosystem functioning are discussed with special reference to the role of spatial and temporal heterogeneity and functional redundancy.

Reconfigurable and responsive droplet-based compound micro-lenses.

PubMed

Nagelberg, Sara; Zarzar, Lauren D; Nicolas, Natalie; Subramanian, Kaushikaram; Kalow, Julia A; Sresht, Vishnu; Blankschtein, Daniel; Barbastathis, George; Kreysing, Moritz; Swager, Timothy M; Kolle, Mathias

2017-03-07

Micro-scale optical components play a crucial role in imaging and display technology, biosensing, beam shaping, optical switching, wavefront-analysis, and device miniaturization. Herein, we demonstrate liquid compound micro-lenses with dynamically tunable focal lengths. We employ bi-phase emulsion droplets fabricated from immiscible hydrocarbon and fluorocarbon liquids to form responsive micro-lenses that can be reconfigured to focus or scatter light, form real or virtual images, and display variable focal lengths. Experimental demonstrations of dynamic refractive control are complemented by theoretical analysis and wave-optical modelling. Additionally, we provide evidence of the micro-lenses' functionality for two potential applications-integral micro-scale imaging devices and light field display technology-thereby demonstrating both the fundamental characteristics and the promising opportunities for fluid-based dynamic refractive micro-scale compound lenses.

Reconfigurable and responsive droplet-based compound micro-lenses

PubMed Central

Nagelberg, Sara; Zarzar, Lauren D.; Nicolas, Natalie; Subramanian, Kaushikaram; Kalow, Julia A.; Sresht, Vishnu; Blankschtein, Daniel; Barbastathis, George; Kreysing, Moritz; Swager, Timothy M.; Kolle, Mathias

2017-01-01

Micro-scale optical components play a crucial role in imaging and display technology, biosensing, beam shaping, optical switching, wavefront-analysis, and device miniaturization. Herein, we demonstrate liquid compound micro-lenses with dynamically tunable focal lengths. We employ bi-phase emulsion droplets fabricated from immiscible hydrocarbon and fluorocarbon liquids to form responsive micro-lenses that can be reconfigured to focus or scatter light, form real or virtual images, and display variable focal lengths. Experimental demonstrations of dynamic refractive control are complemented by theoretical analysis and wave-optical modelling. Additionally, we provide evidence of the micro-lenses' functionality for two potential applications—integral micro-scale imaging devices and light field display technology—thereby demonstrating both the fundamental characteristics and the promising opportunities for fluid-based dynamic refractive micro-scale compound lenses. PMID:28266505

Micro-laser

DOEpatents

Hutchinson, Donald P.; Richards, Roger K.

2003-07-22

A micro-laser is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide and at least one amplifying medium in the waveguide. PBG features are positioned between the first and second subwavelength resonant gratings and allow introduction of amplifying mediums into the highly resonant guided micro-laser microcavity. The micro-laser may be positioned on a die of a bulk substrate material with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a micro-laser is disclosed. A method for tuning the micro-laser is also disclosed. The micro-laser may be used as an optical regenerator, or a light source for data transfer or for optical computing.

Wavelength-addressed intra-board optical interconnection by plug-in alignment with a micro hole array

NASA Astrophysics Data System (ADS)

Nakama, Kenichi; Tokiwa, Yuu; Mikami, Osamu

2010-09-01

Intra-board interconnection between optical waveguide channels is suitable for assembling high-speed optoelectronic printed wiring boards (OE-PWB). Here, we propose a novel optical interconnection method combining techniques for both wavelength-based optical waveguide addressing and plug-in optical waveguide alignment with a micro-hole array (MHA). This array was fabricated by the mask transfer method. For waveguide addressing, we used a micro passive wavelength selector (MPWS) module, which is a type of Littrow mount monochromator consisting of an optical diffraction grating, a focusing lens, and the MHA. From the experimental results, we found that the wavelength addressing operation of the MPWS module was effective for intra-board optical interconnection.

Update on optical design of adaptive optics system at Lick Observatory

NASA Astrophysics Data System (ADS)

Bauman, Brian J.; Gavel, Donald T.; Waltjen, Kenneth E.; Freeze, Gary J.; Hurd, Randall L.; Gates, Elinor L.; Max, Claire E.; Olivier, Scot S.; Pennington, Deanna M.

2002-02-01

In 1999, we presented our plan to upgrade the adaptive optics (AO) system on the Lick Observatory Shane telescope (3m) from a prototype instrument pressed into field service to a facility instrument. This paper updates the progress of that plan and details several important improvements in the alignment and calibration of the AO bench. The paper also includes a discussion of the problems seen in the original design of the tip/tilt (t/t) sensor used in laser guide star mode, and how these problems were corrected with excellent results.

Update on Optical Design of Adaptive Optics System at Lick Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauman, B J; Gavel, D T; Waltjen, K E

2001-07-31

In 1999, we presented our plan to upgrade the adaptive optics (AO) system on the Lick Observatory Shane telescope (3m) from a prototype instrument pressed into field service to a facility instrument. This paper updates the progress of that plan and details several important improvements in the alignment and calibration of the AO bench. The paper also includes a discussion of the problems seen in the original design of the tip/tilt (t/t) sensor used in laser guide star mode, and how these problems were corrected with excellent results.

Fiber optic engine for micro projection display.

PubMed

Arabi, Hesam Edin; An, Sohee; Oh, Kyunghwan

2010-03-01

A novel compact optical engine for a micro projector display is experimentally demonstrated, which is composed of RGB light sources, a tapered 3 x 1 Fiber Optic Color Synthesizer (FOCS) along with a fiberized ball-lens, and a two dimensional micro electromechanical scanning mirror. In the proposed optical engine, we successfully employed an all-fiber beam shaping technique combining optical fiber taper and fiberized ball lens that can render a narrow beam and enhance the resolution of the screened image in the far field. Optical performances of the proposed device assembly are investigated in terms of power loss, collimating strength of the collimator assembly, and color gamut of the output.

Technical Digest of the 1998 Summer Topical Meeting on Organic Optics and Optoelectronics

DTIC Science & Technology

1998-07-01

substantially larger voltages (~2x), however, signal distortion and inter- symbol interference due to multiple RF reflections limit their...technology as data page composers. Texas Instrument’s DMD 0-7803-4953-9/98$10.00©1998 IEEE system has already been used in this capacity in several... lithography for fabricating and integrating the heads and sliders. The application of MEMS components and micromachined optical bench packaging techniques

MEMS: A new approach to micro-optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sniegowski, J.J.

1997-12-31

MicroElectroMechanical Systems (MEMS) and their fabrication technologies provide great opportunities for application to micro-optical systems (MOEMS). Implementing MOEMS technology ranges from simple, passive components to complicated, active systems. Here, an overview of polysilicon surface micromachining MEMS combined with optics is presented. Recent advancements to the technology, which may enhance its appeal for micro-optics applications are emphasized. Of all the MEMS fabrication technologies, polysilicon surface micromachining technology has the greatest basis in and leverages the most the infrastructure for silicon integrated circuit fabrication. In that respect, it provides the potential for very large volume, inexpensive production of MOEMS. This paper highlightsmore » polysilicon surface micromachining technology in regards to its capability to provide both passive and active mechanical elements with quality optical elements.« less

Thermo-optical dynamics in an optically pumped Photonic Crystal nano-cavity.

PubMed

Brunstein, M; Braive, R; Hostein, R; Beveratos, A; Rober-Philip, I; Sagnes, I; Karle, T J; Yacomotti, A M; Levenson, J A; Moreau, V; Tessier, G; De Wilde, Y

2009-09-14

Linear and non-linear thermo-optical dynamical regimes were investigated in a photonic crystal cavity. First, we have measured the thermal relaxation time in an InP-based nano-cavity with quantum dots in the presence of optical pumping. The experimental method presented here allows one to obtain the dynamics of temperature in a nanocavity based on reflectivity measurements of a cw probe beam coupled through an adiabatically tapered fiber. Characteristic times of 1.0+/-0.2 micros and 0.9+/-0.2 micros for the heating and the cooling processes were obtained. Finally, thermal dynamics were also investigated in a thermo-optical bistable regime. Switch-on/off times of 2 micros and 4 micros respectively were measured, which could be explained in terms of a simple non-linear dynamical representation.

Demonstration of sub-picometer length measurements and sub-nanoradian angular read-out in the millihertz-frequency range

NASA Astrophysics Data System (ADS)

Diekmann, Christian; Troebs, Michael; Steier, Frank; Bykov, Iouri; Heinzel, Gerhard; Danzmann, Karsten

The space-based interferometric gravitational-wave detector Laser Interferometer Space An-tenna (LISA) requires interferometry with subpicometer and nanoradian sensitivity in the fre-quency range between 3 mHz and 1 Hz. Currently, a first prototype of the optical bench for LISA is being designed. We report on a pre-experiment with the aim to demonstrate the required sensitivities and to thoroughly characterise the equipment. For this purpose, a quasi-monolithic optical setup has been built with two Mach-Zehnder interferometers (MZI) on an optical bench made of zerodur. In a first step the relative length change between these two MZI will be measured with a heterodyne modulation scheme in the kHz-range and the angle between two laser beams will be read out via quadrant photodiodes and a technique called differential wavefront sensing. These techniques have already been used for the LISA prede-cessor mission LISA Pathfinder and their sensitivity needs to be further improved to fulfill the requirements of the LISA mission. We describe the experiment and the characterization of the basic components. Measurements of the length and angular noise will be presented.

Monolithic integration of elliptic-symmetry diffractive optical element on silicon-based 45 degrees micro-reflector.

PubMed

Lan, Hsiao-Chin; Hsiao, Hsu-Liang; Chang, Chia-Chi; Hsu, Chih-Hung; Wang, Chih-Ming; Wu, Mount-Learn

2009-11-09

A monolithically integrated micro-optical element consisting of a diffractive optical element (DOE) and a silicon-based 45 degrees micro-reflector is experimentally demonstrated to facilitate the optical alignment of non-coplanar fiber-to-fiber coupling. The slanted 45 degrees reflector with a depth of 216 microm is fabricated on a (100) silicon wafer by anisotropic wet etching. The DOE with a diameter of 174.2 microm and a focal length of 150 microm is formed by means of dry etching. Such a compact device is suitable for the optical micro-system to deflect the incident light by 90 degrees and to focus it on the image plane simultaneously. The measured light pattern with a spot size of 15 microm has a good agreement with the simulated result of the elliptic-symmetry DOE with an off-axis design for eliminating the strongly astigmatic aberration. The coupling efficiency is enhanced over 10-folds of the case without a DOE on the 45 degrees micro-reflector. This device would facilitate the optical alignment of non-coplanar light coupling and further miniaturize the volume of microsystem.

Investigating the Relationship among the Level of Mobbing Experience, Job Satisfaction and Burnout Levels of Primary and Secondary School Teachers

ERIC Educational Resources Information Center

Okçu, Veysel; Çetin, Hakan

2017-01-01

The aim of this study is to examine the level of mobbing experienced by primary and secondary school teachers and to determine how and to what extent this affects their job satisfaction and burnout levels. This research used a relational survey model. As a result of the study, it has been determined that there is a negative and medium-level…

Mobbing and psychological terror at workplaces.

PubMed

Leymann, H

1990-01-01

In recent years, the existence of a significant problem in workplaces has been documented in Sweden and other countries. It involves employees "ganging up" on a target employee and subjecting him or her to psychological harassment. This "mobbing" behavior results in severe psychological and occupational consequences for the victim. This phenomenon is described, its stages and consequences analyzed. An ongoing program of research and intervention that is currently being supported by the Swedish government is then considered.

The risk of predation favors cooperation among breeding prey

PubMed Central

Krama, Tatjana; Berzins, Arnis; Rantala, Markus J

2010-01-01

Empirical studies have shown that animals often focus on short-term benefits under conditions of predation risk, which reduces the likelihood that they will cooperate with others. However, some theoretical studies predict that animals in adverse conditions should not avoid cooperation with their neighbors since it may decrease individual risks and increase long-term benefits of reciprocal help. We experimentally tested these two alternatives to find out whether increased predation risk enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behavior, among breeding pied flycatchers, Ficedula hypoleuca. Our results show that birds attended mobs initiated by their neighbors more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. This study demonstrates a positive impact of predation risk on cooperation in breeding songbirds, which might help to explain the emergence and evolution of cooperation. PMID:20714404

Workplace mobbing: How the victim's coping behavior influences bystander responses.

PubMed

Mulder, Roelie; Bos, Arjan E R; Pouwelse, Mieneke; van Dam, Karen

2017-01-01

Victims of workplace mobbing show diverse coping behavior. We investigated the impact of this behavior on bystander cognitions, emotions, and helping toward the victim, integrating coping literature with attribution theory. Adult part-time university students (N = 161) working at various organizations participated in a study with a 3(Coping: approach/avoidance/neutral) × 2(Gender Victim: male/female) × 2(Gender Bystander: male/female) design. Victims showing approach (vs. avoidance) coping were considered to be more self-reliant and less responsible for the continuation of the mobbing, and they elicited less anger. Continuation responsibility and self-reliance mediated the relationship between the victim's coping behavior and bystanders' helping intentions. Female (vs. male) participants reported more sympathy for the victim and greater willingness to help, and female (vs. male) victims elicited less anger. Theoretical and practical implications of the findings are discussed.

From optics testing to micro optics testing

NASA Astrophysics Data System (ADS)

Brock, Christian; Dorn, Ralf; Pfund, Johannes

2017-10-01

Testing micro optics, i.e. lenses with dimensions down to 0.1mm and less, with high precision requires a dedicated design of the testing device, taking into account propagation and wave-optical effects. In this paper, we discuss testing methods based on Shack-Hartmann wavefront technology for functional testing in transmission and for the measurement of surface shape in reflection. As a first example of more conventional optics testing, i.e. optics in the millimeter range, we present the measurement of binoculars in transmission, and discuss the measured wave aberrations and imaging quality. By repeating the measurement at different wavelengths, information on chromatic effects is retrieved. A task that is often tackled using Shack-Hartman wavefront sensors is the alignment of collimation optics in front of a light source. In case of a micro-optical collimation unit with a 1/e² beam diameter of ca. 1mm, we need adapted relay optics for suitable beam expansion and well-defined imaging conditions. In this example, we will discuss the alignment process and effects of the relay optics magnification, as well as typical performance data. Oftentimes, micro optics are fabricated not as single pieces, but as mass optics, e.g. by lithographic processes. Thus, in order to reduce tooling and alignment time, an automated test procedure is necessary. We present an approach for the automated testing of wafer- or tray-based micro optics, and discuss transmission and reflection measurement capabilities. Exemplary performance data is shown for a sample type with 30 microns in diameter, where typical repeatabilities of a few nanometers (rms) are reached.

High temporal and spatial variability of atmospheric-methane oxidation in Alpine glacier-forefield soils.

PubMed

Chiri, Eleonora; Nauer, Philipp A; Rainer, Edda-Marie; Zeyer, Josef; Schroth, Martin H

2017-07-07

Glacier-forefield soils can provide a substantial sink for atmospheric CH 4 , facilitated by aerobic methane-oxidizing bacteria (MOB). However, MOB activity, abundance, and community structure may be affected by soil age, location in different forefield landforms, and temporal fluctuations in soil-physical parameters. We assessed spatial and temporal variability of atmospheric CH 4 oxidation in an Alpine glacier forefield during the snow-free season 2013. We quantified CH 4 flux in soils of increasing age and in different landforms (sandhill, terrace, floodplain) using soil-gas-profile and static flux-chamber methods. To determine MOB abundance and community structure, we employed pmoA -gene-based quantitative PCR and targeted-amplicon sequencing. Uptake of CH 4 increased in magnitude and decreased in variability with increasing soil age. Sandhill soils exhibited CH 4 uptake ranging from -0.03- -3.7 mg CH 4 m -2 d -1 Floodplain and terrace soils exhibited smaller uptake and even intermittent CH 4 emissions. Linear mixed-effect models indicated that soil age and landform were dominating factors shaping CH 4 flux, followed by cumulative rainfall (weighted sum ≤ 4 d prior to sampling). Of 31 MOB operational taxonomic units retrieved, ∼30% were potentially novel, and ∼50% were affiliated with Upland Soil Clusters gamma and alpha. The MOB community structures in floodplain and terrace soils were nearly identical, but differed significantly from highly variable sandhill-soil communities. We conclude that soil age and landform modulate the soil CH 4 sink strength in glacier forefields, and recent rainfall affects its short-term variability. This should be taken into account when including this environment in future CH 4 inventories. Importance Oxidation of methane (CH 4 ) in well-drained, "upland" soils is an important mechanism for the removal of this potent greenhouse gas from the atmosphere. It is largely mediated by aerobic, methane-oxidizing bacteria (MOB). Whereas there is abundant information on atmospheric CH 4 oxidation in mature upland soils, little is known about this important function in young, developing soils such as those found in glacier forefields, where new sediments are continuously exposed to the atmosphere as a result of glacial retreat.In this field-based study we investigated spatial and temporal variability of atmospheric CH 4 oxidation and associated MOB communities in Alpine glacier-forefield soils, aiming at better understanding factors that shape the sink for atmospheric CH 4 in this young soil ecosystem. The study contributes to the knowledge on the dynamics of atmospheric CH 4 oxidation in developing upland soils, and represents a further step towards the inclusion of Alpine glacier-forefield soils in global CH 4 inventories. Copyright © 2017 American Society for Microbiology.

Characterization of the dimensional stability of advanced metallic materials using an optical test bench structure

NASA Technical Reports Server (NTRS)

Hsieh, Cheng; O'Donnell, Timothy P.

1991-01-01

The dimensional stability of low-density high specific-strength metal-matrix composites (including 30 vol pct SiC(p)/SXA 24-T6 Al, 25 vol pct SiC(p)/6061-T6 Al, 40 vol pct graphite P100 fiber/6061 Al, 50 vol pct graphite P100 fiber/6061 Al, and 40 vol pct P100 graphite fiber/AZ91D Mg composites) and an Al-Li-Mg metal alloy was evaluated using a specially designed five-strut optical test bench structure. The structure had 30 thermocouple locations, one retroreflector, one linear interferometer multilayer insulation, and various strip heaters. It was placed in a 10 exp -7 torr capability vacuum chamber with a laser head positioned at a window port, and a laser interferometer system for collecting dimensional change data. It was found that composite materials have greater 40-C temporal dimensional stability than the AL-Li-Mg alloy. Aluminum-based composites demonstrated better 40-C temporal stability than Mg-based composites.

Analysis of target wavefront error for secondary mirror of a spaceborne telescope

NASA Astrophysics Data System (ADS)

Chang, Shenq-Tsong; Lin, Wei-Cheng; Kuo, Ching-Hsiang; Chan, Chia-Yen; Lin, Yu-Chuan; Huang, Ting-Ming

2014-09-01

During the fabrication of an aspherical mirror, the inspection of the residual wavefront error is critical. In the program of a spaceborne telescope development, primary mirror is made of ZERODUR with clear aperture of 450 mm. The mass is 10 kg after lightweighting. Deformation of mirror due to gravity is expected; hence uniform supporting measured by load cells has been applied to reduce the gravity effect. Inspection has been taken to determine the residual wavefront error at the configuration of mirror face upwards. Correction polishing has been performed according to the measurement. However, after comparing with the data measured by bench test while the primary mirror is at a configuration of mirror face horizontal, deviations have been found for the two measurements. Optical system that is not able to meet the requirement is predicted according to the measured wavefront error by bench test. A target wavefront error of secondary mirror is therefore analyzed to correct that of primary mirror. Optical performance accordingly is presented.

Photonic Doppler velocimetry probe designed with stereo imaging

NASA Astrophysics Data System (ADS)

Malone, Robert M.; Cata, Brian M.; Daykin, Edward P.; Esquibel, David L.; Frogget, Brent C.; Holtkamp, David B.; Kaufman, Morris I.; McGillivray, Kevin D.; Palagi, Martin J.; Pazuchanics, Peter; Romero, Vincent T.; Sorenson, Danny S.

2014-09-01

During the fabrication of an aspherical mirror, the inspection of the residual wavefront error is critical. In the program of a spaceborne telescope development, primary mirror is made of ZERODUR with clear aperture of 450 mm. The mass is 10 kg after lightweighting. Deformation of mirror due to gravity is expected; hence uniform supporting measured by load cells has been applied to reduce the gravity effect. Inspection has been taken to determine the residual wavefront error at the configuration of mirror face upwards. Correction polishing has been performed according to the measurement. However, after comparing with the data measured by bench test while the primary mirror is at a configuration of mirror face horizontal, deviations have been found for the two measurements. Optical system that is not able to meet the requirement is predicted according to the measured wavefront error by bench test. A target wavefront error of secondary mirror is therefore analyzed to correct that of primary mirror. Optical performance accordingly is presented.

Mechanism Design Principle for Optical-Precision, Deployable Instruments

NASA Technical Reports Server (NTRS)

Lake, Mark S.; Hachkowski, M. Roman

2000-01-01

The present paper is intended to be a guide for the design of 'microdynamically quiet' deployment mechanisms for optical-precision structures, such as deployable telescope mirrors and optical benches. Many of the guidelines included herein come directly from the field of optomechanical engineering, and are neither newly developed guidelines nor are they uniquely applicable to high-precision deployment mechanisms. However, the application of these guidelines to the design of deployment mechanisms is a rather new practice, so efforts are made herein to illustrate the process through the discussion of specific examples. The present paper summarizes a more extensive set of design guidelines for optical-precision mechanisms that are under development.

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter.

PubMed

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-03-09

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter

PubMed Central

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-01-01

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics. PMID:28276500

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter

NASA Astrophysics Data System (ADS)

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-03-01

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

Micro electro mechanical system optical switching

DOEpatents

Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

2013-12-17

The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

Performance and durability testing of parabolic trough receivers

NASA Astrophysics Data System (ADS)

Lei, Dongqiang; Fu, Xuqiang; Zhao, Dongming; Yuan, Guofeng; Wang, Zhifeng; Guo, Minghuan

2017-06-01

The paper describes the key performance and durability testing facilities of the parabolic trough receiver developed by Institute of Electrical Engineering, Chinese Academy of Sciences. The indoor heat loss test can be applied at 4-7 different temperature levels within 200-550 on receivers. The optical efficiency test bench consists of 12 metal halide lamps as the solar simulator and a 5 m length half-elliptical cylinder reflector with flat end reflectors. 3 ultra-precision temperature sensors are used in receiver each end to get the temperature difference. The residual gas analysis test bench is applied to analyze and predict the vacuum lifetime of the receiver. It can test the variations of composition and partial pressure of residual gases with temperature and time in the receiver annulus space by a high sensitivity quadrupole mass spectrometer gas analyzer. A coating accelerated ageing test bench, which is also used to test the thermal cycle, has been developed. This test bench uses the absorber tube of the recevier as the resistance heater to heat up the whole receiver. The coating lifetime can be predicted by the Arrhenius parameters. For the cycling test, the compressed air is used to directly cool the inner surface of the absorber tube. The thermal cycling test is performed with temperature cycles from 150 °C to 450 °C for 160 cycles. The maximum thermal cycling frequency is 8 cycles per day. The mechanical fatigue test bench is used to test the bellows and the glass-to-metal seals durability at the same time. Both bellows are expanded and compressed to 6.5 mm in turn with 10,000 cycles. A new rotating test bench was also developed to test the thermal efficiency of the receiver.

Waveguide-loaded silica fibers for coupling to high-index micro-resonators

NASA Astrophysics Data System (ADS)

Latawiec, P.; Burek, M. J.; Venkataraman, V.; Lončar, M.

2016-01-01

Tapered silica fibers are often used to rapidly probe the optical properties of micro-resonators. However, their low refractive index precludes phase-matching when coupling to high-index micro-resonators, reducing efficiency. Here, we demonstrate efficient optical coupling from tapered fibers to high-index micro-resonators by loading the fibers with an ancillary adiabatic waveguide-coupler fabricated via angled-etching. We demonstrate greatly enhanced coupling to a silicon multimode micro-resonator when compared to coupling via the bare fiber only. Signatures of resonator optical bistability are observed at high powers. This scheme can be applied to resonators of any size and material, increasing the functional scope of fiber coupling.

High Energy Replicated Optics to Explore the Sun: Hard X-Ray Balloon-Borne Telescope

NASA Technical Reports Server (NTRS)

Gaskin, Jessica; Apple, Jeff; StevensonChavis, Katherine; Dietz, Kurt; Holt, Marlon; Koehler, Heather; Lis, Tomasz; O'Connor, Brian; RodriquezOtero, Miguel; Pryor, Jonathan;

High Energy Replicated Optics to Explore the Sun: Hard X-ray balloon-borne telescope

NASA Astrophysics Data System (ADS)

Gaskin, J.; Apple, J.; Chavis, K. S.; Dietz, K.; Holt, M.; Koehler, H.; Lis, T.; O'Connor, B.; Otero, M. R.; Pryor, J.; Ramsey, B.; Rinehart-Dawson, M.; Smith, L.; Sobey, A.; Wilson-Hodge, C.; Christe, S.; Cramer, A.; Edgerton, M.; Rodriguez, M.; Shih, A.; Gregory, D.; Jasper, J.; Bohon, S.

Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber - and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HERO gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. A mechanical shutter will be added to the star camera to protect it during solar observations. HEROES will also implement two novel alignment monitoring system that will measure the alignment between the optical bench and the star camera and between the optics and detectors for improved pointing and post-flight data reconstruction. The overall payload will also be discussed. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.

Suppressing ghost beams: Backlink options for LISA

NASA Astrophysics Data System (ADS)

Isleif, K.-S.; Gerberding, O.; Penkert, D.; Fitzsimons, E.; Ward, H.; Robertson, D.; Livas, J.; Mueller, G.; Reiche, J.; Heinzel, G.; Danzmann, K.

2017-05-01

In this article we discuss possible design options for the optical phase reference system, the so called backlink, between two moving optical benches in a LISA satellite. The candidates are based on two approaches: Fiber backlinks, with additional features like mode cleaning cavities and Faraday isolators, and free beam backlinks with angle compensation techniques. We will indicate dedicated ghost beam mitigation strategies for the design options and we will point out critical aspects in case of an implementation in LISA.

Research study entitled advanced X-ray astrophysical observatory (AXAF). [system engineering for a total X-ray telescope assembly

NASA Technical Reports Server (NTRS)

Rasche, R. W.

1979-01-01

General background and overview material are presented along with data from studies performed to determine the sensitivity, feasibility, and required performance of systems for a total X-ray telescope assembly. Topics covered include: optical design, mirror support concepts, mirror weight estimates, the effects of l g on mirror elements, mirror assembly resonant frequencies, optical bench considerations, temperature control of the mirror assembly, and the aspect determination system.

Design, fabrication and testing of hierarchical micro-optical structures and systems

NASA Astrophysics Data System (ADS)

Cannistra, Aaron Thomas

Micro-optical systems are becoming essential components in imaging, sensing, communications, computing, and other applications. Optically based designs are replacing electronic, chemical and mechanical systems for a variety of reasons, including low power consumption, reduced maintenance, and faster operation. However, as the number and variety of applications increases, micro-optical system designs are becoming smaller, more integrated, and more complicated. Micro and nano-optical systems found in nature, such as the imaging systems found in many insects and crustaceans, can have highly integrated optical structures that vary in size by orders of magnitude. These systems incorporate components such as compound lenses, anti-reflective lens surface structuring, spectral filters, and polarization selective elements. For animals, these hybrid optical systems capable of many optical functions in a compact package have been repeatedly selected during the evolutionary process. Understanding the advantages of these designs gives motivation for synthetic optical systems with comparable functionality. However, alternative fabrication methods that deviate from conventional processes are needed to create such systems. Further complicating the issue, the resulting device geometry may not be readily compatible with existing measurement techniques. This dissertation explores several nontraditional fabrication techniques for optical components with hierarchical geometries and measurement techniques to evaluate performance of such components. A micro-transfer molding process is found to produce high-fidelity micro-optical structures and is used to fabricate a spectral filter on a curved surface. By using a custom measurement setup we demonstrate that the spectral filter retains functionality despite the nontraditional geometry. A compound lens is fabricated using similar fabrication techniques and the imaging performance is analyzed. A spray coating technique for photoresist application to curved surfaces combined with interference lithography is also investigated. Using this technique, we generate polarizers on curved surfaces and measure their performance. This work furthers an understanding of how combining multiple optical components affects the performance of each component, the final integrated devices, and leads towards realization of biomimetically inspired imaging systems.

Month of birth and life expectancy: role of gender and age in a comparative approach

NASA Astrophysics Data System (ADS)

Lerchl, Alexander

2004-09-01

The effects of month of birth (MOB) on life expectancy of a German subpopulation was investigated. Data from people who died in North Rhine Westphalia in the years 1984 (n=188,515) and 1999 (n=188,850) were analyzed. For comparative purposes, all deaths that occurred at an age of <50 years were excluded (1984: 8.4%; 1999: 6.2%). In general, individuals born in May through July had the lowest age at death (1984: 75.27±0.09 years; 1999: 77.58±0.09 years), while those born between October and December had the highest (1984: 75.98±0.08 years; 1999: 78.35±0.09 years), supporting earlier findings. The observed amplitudes (differences between highest and lowest values) were more pronounced in men than in women. When comparing these data of MOB effects on life expectancy with earlier findings in Australia, Austria, Denmark, Ukraine, and the USA, it is evident that a negative correlation exists between the average age at death and the MOB amplitudes. Separate analyses by gender, possible for the data from Germany, the Ukraine, and the USA, revealed a significant negative correlation for men, but not for women. A new hypothesis is therefore presented describing an influence of life quality, as reflected by average life expectancy, on the extent of MOB effects; for example, seasonally variable sensitivities during pregnancy/early childhood.

Whisper-like behavior in a non-human primate.

PubMed

Morrison, Rachel; Reiss, Diana

2013-01-01

In humans, whispering has evolved as a counteractive strategy against eavesdropping. Some evidence for whisper-like behavior exists in a few other species, but has not been reported in non-human primates. We discovered the first evidence of whisper-like behavior in a non-human primate, the cotton-top tamarin (Saguinus oedipus), in the course of investigating their use of human-directed mobbing calls. We exposed a family of captive cotton-top tamarins to a supervisor who previously elicited a strong mobbing response. Simultaneous audio-video recordings documented the animals' behavioral and vocal responses in the supervisor's presence and absence. Rather than exhibiting a mobbing response and producing loud human-directed mobbing calls, the tamarins exhibited other anti-predator behaviors and produced low amplitude vocalizations that initially eluded our detection. A post-hoc analysis of the data was conducted to test a new hypothesis-the tamarins were reducing the amplitude of their vocalizations in the context of exposure to a potential threat. Consistent with whisper-like behavior, the amplitude of the tamarins' vocalizations was significantly reduced only in the presence of the supervisor. Due to its subtle properties, this phenomenon may have eluded detection in this species. Increasing evidence of whisper-like behavior in non-human species suggests that such low amplitude signaling may represent a convergence in a communication strategy amongst highly social and cooperative species. © 2013 Wiley Periodicals, Inc.

Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sathishkumar, P.; Punyabrahma, P.; Sri Muthu Mrinalini, R.

A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array.

Trapping of a micro-bubble by non-paraxial Gaussian beam: computation using the FDTD method.

PubMed

Sung, Seung-Yong; Lee, Yong-Gu

2008-03-03

Optical forces on a micro-bubble were computed using the Finite Difference Time Domain method. Non-paraxial Gaussian beam equation was used to represent the incident laser with high numerical aperture, common in optical tweezers. The electromagnetic field distribution around a micro-bubble was computed using FDTD method and the electromagnetic stress tensor on the surface of a micro-bubble was used to compute the optical forces. By the analysis of the computational results, interesting relations between the radius of the circular trapping ring and the corresponding stability of the trap were found.

MicroSight Optics

ScienceCinema

None

2018-05-16

MicroSight is an innovative gunsight technology that allows a marksman's eye to focus on both the front gunsight and the intended target. The MicroSight improves both firearm safety and performance by imaging two objects at different focal distances. The MicroSight was developed at Idaho National Laboratory, and has been licensed by Apollo Optical Systems. You can learn more about INL's research programs at http://www.facebook.com/idahonationallaboratory.

MicroSight Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-01-01

MicroSight is an innovative gunsight technology that allows a marksman's eye to focus on both the front gunsight and the intended target. The MicroSight improves both firearm safety and performance by imaging two objects at different focal distances. The MicroSight was developed at Idaho National Laboratory, and has been licensed by Apollo Optical Systems. You can learn more about INL's research programs at http://www.facebook.com/idahonationallaboratory.

III-V Semiconductor Optical Micro-Ring Resonators

NASA Astrophysics Data System (ADS)

Grover, Rohit; Absil, Philippe P.; Ibrahim, Tarek A.; Ho, Ping-Tong

2004-05-01

We describe the theory of optical ring resonators, and our work on GaAs-AlGaAs and GaInAsP-InP optical micro-ring resonators. These devices are promising building blocks for future all-optical signal processing and photonic logic circuits. Their versatility allows the fabrication of ultra-compact multiplexers/demultiplexers, optical channel dropping filters, lasers, amplifiers, and logic gates (to name a few), which will enable large-scale monolithic integration for optics.

Magnetic field detection using magnetorheological optical resonators

NASA Astrophysics Data System (ADS)

Rubino, Edoardo; Ioppolo, Tindaro

2018-02-01

In this paper, we investigate the feasibility of a magnetic field sensor that is based on a magnetorheological micro-optical resonator. The optical resonator has a spherical shape and a diameter of a few hundred micrometers. The resonator is fabricated by using a polymeric matrix made of polyvinyl chloride (PVC) plastisol with embedded magnetically polarizable micro-particles. When the optical resonator is subjected to an external magnetic field, the morphology (radius and refractive index) of the resonator is perturbed by the magnetic forces acting on it, leading to a shift of the optical resonances also known as whispering gallery modes (WGM). In this study, the effect of a static and harmonic magnetic field, as well as the concentration of the magnetic micro-particles on the optical mode shift is investigated. The optical resonances obtained with the PVC plastisol resonator showed a quality factor of 106 . The dynamical behavior of the optical resonator is investigated in the range between 0 and 200 Hz. The sensitivity of the optical resonator reaches a maximum value for a ratio between micro-particles and the polymeric matrix of 2:1 in weight. Experimental results indicate a sensitivity of 0.297 pm/mT leading to a resolution of 336 μT.

Morphologies and optical and electrical properties of InGaN/GaN micro-square array light-emitting diode chips.

PubMed

Han, Dan; Ma, Shufang; Jia, Zhigang; Liu, Peizhi; Jia, Wei; Shang, Lin; Zhai, Guangmei; Xu, Bingshe

2018-04-10

InGaN/GaN micro-square array light-emitting diode (LED) chips (micro-chips) have been prepared via the focused ion beam (FIB) etching technique, which can not only reduce ohmic contact degradation but also control the aspect ratio precisely in three-dimensional (3D) structure LED (3D-LED) device fabrication. The effects of FIB beam current and micro-square array depth on morphologies and optical and electrical properties of the micro-chips have been studied. Our results show that sidewall surface morphology and optical and electrical properties of the micro-chips degrade with increased beam current. After potassium hydroxide etching with different times, an optimal current-voltage and luminescence performance can be obtained. Combining the results of cathodoluminescence mappings and light output-current characteristics, the light extraction efficiency of the micro-chips is reduced as FIB etch depth increases. The mechanisms of micro-square depth on light extraction have been revealed by 3D finite difference time domain.

SXI Prototype mirror mount

NASA Technical Reports Server (NTRS)

1995-01-01

This final report describes the work performed from June 1993 to January 1995. The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule.

Activity and diversity of aerobic methanotrophs in a coastal marine oxygen minimum zone

NASA Astrophysics Data System (ADS)

Padilla, C. C.; Bristow, L. A.; Sarode, N. D.; Garcia-Robledo, E.; Girguis, P. R.; Thamdrup, B.; Stewart, F. J.

2016-02-01

The pelagic ocean is a sink for the potent greenhouse gas methane, with methane consumption regulated primarily by aerobic methane-oxidizing bacteria (MOB). Marine oxygen minimum zones (OMZs) contain the largest pool of pelagic methane in the oceans but remain largely unexplored for their potential to harbor MOB communities and contribute to methane cycling. Here, we present meta-omic and geochemical evidence that aerobic MOB are present and active in a coastal OMZ, in Golfo Dulce, Costa Rica. Oxygen concentrations were < 50 nM below 85 m, and sulfide accumulated below 140 m, with methane concentrations ranging from trace levels above the oxycline to 78 nM at 180 m. The upper OMZ (90 m) was characterized by an abundant MOB and methylotroph community representing diverse lineages of the Methylophilaceae, Methylophaga, and Methylococcales. Of these, Type I methanotrophs of the Order Methylococcales dominated , representing >5% of total 16S rRNA genes and >19% of 16S rRNA transcripts. This peak in ribosomal abundance and activity was affiliated with methane oxidation rates of 2.6 ± 0.7 nM d-1, measured in seawater incubations with estimated O2 concentrations of 50 nM. Rates fell to zero with the addition of acetylene, an inhibitor of aerobic methanotrophy. In contrast, methane oxidation was below detection at lower depths in the OMZ (100 m and 120 m). Metatranscriptome sequencing indicated a peak at 90 m in the expression of pathways essential to Methylococcales, including aerobic methanotrophy and the RuMP pathway of carbon assimilation, as well as the serine pathway of Type II methanotrophs. Preliminary analysis of single-cell genomes suggests distinct adaptations by Methylococcales from the Golfo Dulce, helping explain the persistence of putative aerobic methanotrophs under very low oxygen in this OMZ. Taken together, these data suggest the boundary layers of OMZs, despite extreme oxygen depletion, are a niche for aerobic MOBs and therefore potentially important zones of pelagic methane loss.

Sparrowhawk movement, calling, and presence of dead conspecifics differentially impact blue tit (Cyanistes caeruleus) vocal and behavioral mobbing responses.

PubMed

Carlson, Nora V; Pargeter, Helen M; Templeton, Christopher N

2017-01-01

Many animals alter their anti-predator behavior in accordance to the threat level of a predator. While much research has examined variation in mobbing responses to different predators, few studies have investigated how anti-predator behavior is affected by changes in a predator's own state or behavior. We examined the effect of sparrowhawk ( Accipiter nisus ) behavior on the mobbing response of wild blue tits ( Cyanistes caeruleus ) using robotic taxidermy sparrowhawks. We manipulated whether the simulated predator moved its head, produced vocalizations, or held a taxidermy blue tit in its talons. When any sparrowhawk model was present, blue tits decreased foraging and increased anti-predator behavior and vocalizations. Additionally, each manipulation of the model predator's state (moving, vocalizing, or the presence of a dead conspecific) impacted different types of blue tit anti-predator behavior and vocalizations. These results indicate that different components of mobbing vary according to the specific state of a given predator-beyond its presence or absence-and suggest that each might play a different role in the overall mobbing response. Last, our results indicate that using more life-like predator stimuli-those featuring simple head movements and audio playback of vocalizations-changes how prey respond to the predator; these 'robo-raptor' models provide a powerful tool to provide increased realism in simulated predator encounters without sacrificing experimental control. Anti-predatory behavior is often modulated by the threat level posed by a particular predator. While much research has tested how different types of predators change prey behavior, few experiments have examined how predator behavior affects anti-predatory responses of prey. By experimentally manipulating robotic predators, we show that blue tits not only respond to the presence of a sparrowhawk, by decreasing feeding and increasing anti-predator behavior and vocalizations, but that they vary specific anti-predator behaviors when encountering differently behaving predators (moving, vocalizing, or those with captured prey), suggesting that prey pay attention to their predators' state and behavior.

Fossil chironomid d13C as a new proxy for past methanogenic contribution to benthic food-webs in lakes?

NASA Astrophysics Data System (ADS)

van Hardenbroek, M.; Heiri, O. M.; Grey, J.; Bodelier, P. L. E.; Lotter, A. F.

2009-04-01

Lake sediments are an important source of atmospheric methane. Methanogenic archaea in lake sediments produce 13C-depleted methane that is partly released to the water column and the atmosphere. Another part is utilized by methane oxidizing bacteria (MOB) that are an important food source for deposit-feeding chironomid larvae (Diptera: Chironomidae). If methane-derived carbon is a significant component of the chironomid diet this will lead to strongly negative d13C in the tissue and exoskeleton of chironomid larvae. Chironomid cuticles, especially the strongly sclerotized head capsules, are well preserved as fossils in lake sediments. If the relationship between modern methane fluxes in lakes and chironomid d13C can be established this would therefore provide an approach for estimating past methane fluxes based on d13C of fossil chironomid remains. Using culturing experiments we show that the stable carbon isotope signature of MOB and other food sources can be traced in chironomid muscle tissue as well as in the fossilizing exoskeleton. In addition we measured d13C in chironomid larval head capsules and other invertebrate remains from a range of surface and downcore sediment samples. Small intra-specific variability (-27.1 ± 0.08 permille) was measured in replicate samples of chironomid head capsules of Corynocera ambigua (n=7). d13C of chironomid head capsules from a several different taxa ranged from -28.0 to -25.8 permille, but in some instances we observed d13C values as low as -36.9 to -31.5 permille, suggesting that carbon from MOB can be successfully traced in fossil and subfossil chironomid remains. Our results demonstrate that the stable carbon isotope signature of MOB is incorporated into chironomid head capsules. Future research will focus on quantifying the relationship between methane fluxes, MOB, and head capsule d13C in order to reconstruct past methane fluxes based on the lake sediment record.

Oxidation of monohydric phenol substrates by tyrosinase: effect of dithiothreitol on kinetics.

PubMed

Naish-Byfield, S; Cooksey, C J; Riley, P A

1994-11-15

The effect of thiol compounds on the monophenolase activity of tyrosinase was investigated using 4-hydroxyanisole as the substrate and dithiothreitol (DTT) as the model thiol compound. We have demonstrated three actions of DTT on tyrosinase-catalysed reactions: (1) direct reduction of the copper at the active site of the enzyme; (2) generation of secondary, oxidizable species by adduct formation with the o-quinone reaction product, 4-MOB, which leads to an increase in the total oxygen utilization by the reaction system; and (3) reversible inhibition of the enzyme. We confirm our previous observation that, at approx. 10 mol of DTT/mol of enzyme, the lag phase associated with monohydric phenol oxidation by tyrosinase is abolished. We suggest that this is due to reduction of the copper at the active site of the enzyme by DTT, since (a) reduction of active-site copper in situ by DTT was demonstrated by [Cu(I)]2-carbon monoxide complex formation and (b) abolition of the lag at low DTT concentration occurs without effect on the maximum rate of reaction or on the total amount of oxygen utilized. At concentrations of DTT above that required to abolish the lag, we found that the initial velocity of the reaction increased with increasing DTT, with a concomitant increase in the total oxygen utilization. This is due to the formation of DTT-4-methoxy-o-benzoquinone (4-MOB) adducts which provide additional dihydric phenol substrate either directly or by reducing nascent 4-MOB. We present n.m.r. evidence for the formation of mono- and di-aromatic DTT adducts with 4-MOB, consistent with a suggested reoxidation scheme in the presence of tyrosinase. Inhibition of the enzyme at concentrations of DTT above 300 pmol/unit of enzyme was released on exhaustion of DTT by adduct formation with 4-MOB as it was generated.

Activity and diversity of methane-oxidizing bacteria in glacier forefields on siliceous and calcareous bedrock

NASA Astrophysics Data System (ADS)

Nauer, P. A.; Dam, B.; Liesack, W.; Zeyer, J.; Schroth, M. H.

2012-01-01

The global methane (CH4) cycle is largely driven by methanogenic archaea and methane-oxidizing bacteria (MOB), but little is known about their activity and diversity in pioneer ecosystems. We conducted a field survey in forefields of 13 receding Swiss glaciers on both siliceous and calcareous bedrock to investigate and quantify CH4 turnover based on soil-gas CH4 concentration profiles, and to characterize MOB communities using pmoA sequencing and T-RFLP. Methane turnover was fundamentally different in the two bedrock categories. Of the 36 CH4 concentration profiles from siliceous locations, 11 showed atmospheric CH4 consumption at concentrations of ∼1-2 μl l-1 with soil-atmosphere CH4 fluxes of -0.14 to -1.1 mg m-2 d-1. Another 11 profiles showed no apparent activity, while the remaining 14 exhibited slightly increased CH4 concentrations of ∼2-10 μl l-1, most likely due to microsite methanogenesis. In contrast, all profiles from calcareous sites suggested a substantial, yet unknown CH4 source below our sampling zone, with soil-gas CH4 concentrations reaching up to 1400 μl l-1. Remarkably, most soils oxidized ∼90% of the deep-soil CH4, resulting in soil-atmosphere fluxes of 0.12 to 31 mg m-2 d-1. MOB showed limited diversity in both siliceous and calcareous forefields: all identified pmoA sequences formed only 5 OTUs and, with one exception, could be assigned to either Methylocystis or the as-yet-uncultivated Upland Soil Cluster γ (USCγ). The latter dominated T-RFLP patterns of all siliceous and most calcareous samples, while Methylocystis dominated in 4 calcareous samples. As Type I MOB are widespread in cold climate habitats with elevated CH4 concentrations, USCγ might be the corresponding Type I MOBs in habitats exposed to near-atmospheric CH4 concentrations.

Micro-optical elements produced using an photo-embossing technique in photopolymers

NASA Astrophysics Data System (ADS)

O'Neill, Feidhlim T.; Rowsome, Ita C.; Carr, Alun J.; Daniels, Stephen M.; Gleeson, Michael R.; Kelly, John V.; Close, Ciara; Lawrence, Justin R.; Sheridan, John T.

2005-09-01

Micro-optical devices are very important in current high-tech consumer items. The development of future products depends on both the evolution of fabrication techniques and on the development of new low cost mass production methods. Polymers offer ease of fabrication and low cost and are therefore excellent materials for the development of micro-optical devices. Polymer optical devices include passive optical elements, such as microlens arrays and waveguides, as well as active devices such as polymer based lasers. One of the most important areas of micro-optics is that of microlens design, manufacture and testing. The wide diversity of fabrication methods used for the production of these elements indicates their importance. One of these fabrication techniques is photo-embossing. The use of the photo-embossing technique and a photopolymer holographic recording material will be examined in this paper. A discussion of current attempts to model the fabrication process and a review of the experimental method will be given.

SXI prototype mirror mount

NASA Technical Reports Server (NTRS)

1995-01-01

The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve the design, assembly and alignment of the telescope. Finally, a high level assembly and alignment plan for the entire telescope was prepared by UAH. This plan addresses the sequence of assembly, the required assembly and alignment tolerances, and the methods to verify the alignment at each step during the assembly process. This assembly and alignment plan will be used to assemble and integrate the engineering model (EM) of the telescope. Later on, based on this plan more detailed assembly and alignment procedures will be developed for the lower-level assemblies of SXI.

Measurements of the force fields within an acoustic standing wave using holographic optical tweezers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bassindale, P. G.; Drinkwater, B. W.; Phillips, D. B.

2014-04-21

Direct measurement of the forces experienced by micro-spheres in an acoustic standing wave device have been obtained using calibrated optical traps generated with holographic optical tweezers. A micro-sphere, which is optically trapped in three dimensions, can be moved through the acoustic device to measure forces acting upon it. When the micro-sphere is subjected to acoustic forces, it's equilibrium position is displaced to a position where the acoustic forces and optical forces are balanced. Once the optical trapping stiffness has been calibrated, observation of this displacement enables a direct measurement of the forces acting upon the micro-sphere. The measured forces aremore » separated into a spatially oscillating component, attributed to the acoustic radiation force, and a constant force, attributed to fluid streaming. As the drive conditions of the acoustic device were varied, oscillating forces (>2.5 pN{sub pp}) and streaming forces (<0.2 pN) were measured. A 5 μm silica micro-sphere was used to characterise a 6.8 MHz standing wave, λ = 220 μm, to a spatial resolution limited by the uncertainty in the positioning of the micro-sphere (here to within 2 nm) and with a force resolution on the order of 10 fN. The results have application in the design and testing of acoustic manipulation devices.« less

Development and analysis of new type microresonator with electro-optic feedback

NASA Astrophysics Data System (ADS)

Janusas, Giedrius; Palevicius, Arvydas; Cekas, Elingas; Brunius, Alfredas; Bauce, Jokubas

2016-04-01

Micro-resonators are fundamental components integrated in a hosts of MEMS applications: safety and stability systems, biometric sensors, switches, mechanical filters, micro-mirror devices, material characterization, gyroscopes, etc. A constituent part of the micro-resonator is a diffractive optical element (DOE). Different methods and materials are used to produce diffraction gratings for DOEs. Two-dimensional or three-dimensional periodic structures of micrometer-scale period are widely used in microsystems or their components. They can be used as elements for micro-scale synthesis, processing, and analysis of chemical and biological samples. On the other hand micro-resonator was designed using composite piezoelectric material. In case when microscopes, vibrometers or other direct measurement methods are destructive and hardly can be employed for in-situ analysis, indirect measurement of electrical signal generated by composite piezoelectric layer allows to measure natural frequency changes. Also piezoelectric layer allows to create a novel micro-resonator with controllable parameters, which could assure much higher functionality of micro-electromechanical systems. The novel micro-resonator for pollution detection is proposed. Mathematical model of the micro-resonator and its dynamical, electrical and optical characteristics are presented.

Micro-optics: enabling technology for illumination shaping in optical lithography

NASA Astrophysics Data System (ADS)

Voelkel, Reinhard

2014-03-01

Optical lithography has been the engine that has empowered semiconductor industry to continually reduce the half-pitch for over 50 years. In early mask aligners a simple movie lamp was enough to illuminate the photomask. Illumination started to play a more decisive role when proximity mask aligners appeared in the mid-1970s. Off-axis illumination was introduced to reduce diffraction effects. For early projection lithography systems (wafer steppers), the only challenge was to collect the light efficiently to ensure short exposure time. When projection optics reached highest level of perfection, further improvement was achieved by optimizing illumination. Shaping the illumination light, also referred as pupil shaping, allows the optical path from reticle to wafer to be optimized and thus has a major impact on aberrations and diffraction effects. Highly-efficient micro-optical components are perfectly suited for this task. Micro-optics for illumination evolved from simple flat-top (fly's-eye) to annular, dipole, quadrupole, multipole and freeform illumination. Today, programmable micro-mirror arrays allow illumination to be changed on the fly. The impact of refractive, diffractive and reflective microoptics for photolithography will be discussed.

Frequency domain photothermoacoustic signal amplitude dependence on the optical properties of water: turbid polyvinyl chloride-plastisol system.

PubMed

Spirou, Gloria M; Mandelis, Andreas; Vitkin, I Alex; Whelan, William M

2008-05-10

Photoacoustic (more precisely, photothermoacoustic) signals generated by the absorption of photons can be related to the incident laser fluence rate. The dependence of frequency domain photoacoustic (FD-PA) signals on the optical absorption coefficient (micro(a)) and the effective attenuation coefficient (micro(eff)) of a turbid medium [polyvinyl chloride-plastisol (PVCP)] with tissuelike optical properties was measured, and empirical relationships between these optical properties and the photoacoustic (PA) signal amplitude and the laser fluence rate were derived for the water (PVCP system with and without optical scatterers). The measured relationships between these sample optical properties and the PA signal amplitude were found to be linear, consistent with FD-PA theory: micro(a)=a(A/Phi)-b and micro(eff)=c(A/Phi)+d, where Phi is the laser fluence, A is the FD-PA amplitude, and a, ...,d are empirical coefficients determined from the experiment using linear frequency-swept modulation and a lock-in heterodyne detection technique. This quantitative technique can easily be used to measure the optical properties of general turbid media using FD-PAs.

MQ-4C Triton Unmanned Aircraft System (MQ-4C Triton)

DTIC Science & Technology

2015-12-01

will respond to theater level operational or national strategic taskings. MQ-4C Triton December 2015 SAR March 23, 2016 15:26:01 UNCLASSIFIED 6...88% at a mission radius of 2,000 nm Level of Interoperability 1-5 BLOS and LOS from MOB/ FOB (Land Based) MCS BLOS and LOS from MOB/ FOB (Land...MCS UA Mission Radius >=3,000 nm >=3,000 nm >=2,000 nm TBD >=2,000 nm Level Of Interoperability 2 Capability LOS/BLOS multi-ISR payload reception to

Multi-layered fabrication of large area PDMS flexible optical light guide sheets

NASA Astrophysics Data System (ADS)

Green, Robert; Knopf, George K.; Bordatchev, Evgueni V.

2017-02-01

Large area polydimethylsiloxane (PDMS) flexible optical light guide sheets can be used to create a variety of passive light harvesting and illumination systems for wearable technology, advanced indoor lighting, non-planar solar light collectors, customized signature lighting, and enhanced safety illumination for motorized vehicles. These thin optically transparent micro-patterned polymer sheets can be draped over a flat or arbitrarily curved surface. The light guiding behavior of the optical light guides depends on the geometry and spatial distribution of micro-optical structures, thickness and shape of the flexible sheet, refractive indices of the constituent layers, and the wavelength of the incident light. A scalable fabrication method that combines soft-lithography, closed thin cavity molding, partial curing, and centrifugal casting is described in this paper for building thin large area multi-layered PDMS optical light guide sheets. The proposed fabrication methodology enables the of internal micro-optical structures (MOSs) in the monolithic PDMS light guide by building the optical system layer-by-layer. Each PDMS layer in the optical light guide can have the similar, or a slightly different, indices of refraction that permit total internal reflection within the optical sheet. The individual molded layers may also be defect free or micro-patterned with microlens or reflecting micro-features. In addition, the bond between adjacent layers is ensured because each layer is only partially cured before the next functional layer is added. To illustrate the scalable build-by-layers fabrication method a three-layer mechanically flexible illuminator with an embedded LED strip is constructed and demonstrated.

Optical Fiber-Tip Sensors Based on In-Situ µ-Printed Polymer Suspended-Microbeams.

PubMed

Yao, Mian; Ouyang, Xia; Wu, Jushuai; Zhang, A Ping; Tam, Hwa-Yaw; Wai, P K A

2018-06-05

Miniature optical fiber-tip sensors based on directly µ-printed polymer suspended-microbeams are presented. With an in-house optical 3D μ-printing technology, SU-8 suspended-microbeams are fabricated in situ to form Fabry⁻Pérot (FP) micro-interferometers on the end face of standard single-mode optical fiber. Optical reflection spectra of the fabricated FP micro-interferometers are measured and fast Fourier transform is applied to analyze the cavity of micro-interferometers. The applications of the optical fiber-tip sensors for refractive index (RI) sensing and pressure sensing, which showed 917.3 nm/RIU to RI change and 4.29 nm/MPa to pressure change, respectively, are demonstrated in the experiments. The sensors and their optical µ-printing method unveil a new strategy to integrate complicated microcomponents on optical fibers toward 'lab-on-fiber' devices and applications.

Flexible detection optics for light scattering

NASA Astrophysics Data System (ADS)

Taratuta, Victor G.; Hurd, Alan J.; Meyer, Robert B.

1984-05-01

We have designed and built a compact, modular apparatus for the collection, viewing, and detection of scattered light for less than 1200, based on a commercially available optical bench. The novelty of our instrument is that it has the flexibility of modular design while allowing the user to see exactly what is happening: both the real image of the sample and the spatial coherence of the scattered light can be examined. There is built-in control over polarization, filtering, magnification, and other parameters.

Maximizing Computational Capability with Minimal Power

DTIC Science & Technology

2009-03-01

Chip -Scale Energy and Power... and Heat Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...OpticalBench Mounting Posts Imager Chip LCDinterfaced withthecomputer P o l a r i z e r P o l a r i z e r XYZ Translator Optical Slide VMM Computational Pixel...Signal routing power / memory: ? Power does not include comm off chip (i.e. accessing memory) Power = ½ C Vdd2 f for CMOS Chip to Chip (10pF load min

Comprehensive study of electro-optic and passive Q-switching in solid state lasers for altimeter applications

NASA Astrophysics Data System (ADS)

Bhardwaj, Atul; Agrawal, Lalita; Pal, Suranjan; Kumar, Anil

2006-12-01

Laser Science and Technology Center (LASTEC), Delhi, is developing a space qualified diode pumped Nd: YAG laser transmitter capable of generating 10 ns pulses of 30 mJ energy @ 10 pps. This paper presents the results of experiments for comparative studies between electro-optic and passively Q-switched Nd: YAG laser in a crossed porro prism based laser resonator. Experimental studies have been performed by developing an economical bench model of flash lamp pumped Nd: YAG laser (rod dimension, \

High-precision micro-displacement optical-fiber sensor based on surface plasmon resonance.

PubMed

Zhu, Zongda; Liu, Lu; Liu, Zhihai; Zhang, Yu; Zhang, Yaxun

2017-05-15

We propose and demonstrate a novel optical-fiber micro-displacement sensor based on surface plasmon resonance (SPR) by fabricating a Kretschmann configuration on graded-index multimode fiber (GIMMF). We employ a single-mode fiber to change the radial position of the incident beam as the displacement. In the GIMMF, the angle between the light beam and fiber axis, which is closely related to the resonance angle, is changed by the displacement; thus, the resonance wavelength of the fiber SPR shifts. This micro-displacement fiber sensor has a wide detection range of 0-25 μm, a high sensitivity with maximum up to 10.32 nm/μm, and a nanometer resolution with minimum to 2 nm, which transcends almost all of other optical-fiber micro-displacement sensors. In addition, we also research that increasing the fiber polishing angle or medium refractive index can improve the sensitivity. This micro-displacement sensor will have a great significance in many industrial applications and provide a neoteric, rapid, and accurate optical measurement method in micro-displacement.

Deep sequencing of cardiac microRNA-mRNA interactomes in clinical and experimental cardiomyopathy

PubMed Central

Matkovich, Scot J.; Dorn, Gerald W.

2018-01-01

Summary MicroRNAs are a family of short (~21 nucleotide) noncoding RNAs that serve key roles in cellular growth and differentiation and the response of the heart to stress stimuli. As the sequence-specific recognition element of RNA-induced silencing complexes (RISCs), microRNAs bind mRNAs and prevent their translation via mechanisms that may include transcript degradation and/or prevention of ribosome binding. Short microRNA sequences and the ability of microRNAs to bind to mRNA sites having only partial/imperfect sequence complementarity complicates purely computational analyses of microRNA-mRNA interactomes. Furthermore, computational microRNA target prediction programs typically ignore biological context, and therefore the principal determinants of microRNA-mRNA binding: the presence and quantity of each. To address these deficiencies we describe an empirical method, developed via studies of stressed and failing hearts, to determine disease-induced changes in microRNAs, mRNAs, and the mRNAs targeted to the RISC, without cross-linking mRNAs to RISC proteins. Deep sequencing methods are used to determine RNA abundances, delivering unbiased, quantitative RNA data limited only by their annotation in the genome of interest. We describe the laboratory bench steps required to perform these experiments, experimental design strategies to achieve an appropriate number of sequencing reads per biological replicate, and computer-based processing tools and procedures to convert large raw sequencing data files into gene expression measures useful for differential expression analyses. PMID:25836573

Deep sequencing of cardiac microRNA-mRNA interactomes in clinical and experimental cardiomyopathy.

PubMed

Matkovich, Scot J; Dorn, Gerald W

2015-01-01

MicroRNAs are a family of short (~21 nucleotide) noncoding RNAs that serve key roles in cellular growth and differentiation and the response of the heart to stress stimuli. As the sequence-specific recognition element of RNA-induced silencing complexes (RISCs), microRNAs bind mRNAs and prevent their translation via mechanisms that may include transcript degradation and/or prevention of ribosome binding. Short microRNA sequences and the ability of microRNAs to bind to mRNA sites having only partial/imperfect sequence complementarity complicate purely computational analyses of microRNA-mRNA interactomes. Furthermore, computational microRNA target prediction programs typically ignore biological context, and therefore the principal determinants of microRNA-mRNA binding: the presence and quantity of each. To address these deficiencies we describe an empirical method, developed via studies of stressed and failing hearts, to determine disease-induced changes in microRNAs, mRNAs, and the mRNAs targeted to the RISC, without cross-linking mRNAs to RISC proteins. Deep sequencing methods are used to determine RNA abundances, delivering unbiased, quantitative RNA data limited only by their annotation in the genome of interest. We describe the laboratory bench steps required to perform these experiments, experimental design strategies to achieve an appropriate number of sequencing reads per biological replicate, and computer-based processing tools and procedures to convert large raw sequencing data files into gene expression measures useful for differential expression analyses.

Development of a Pyramid Wave-front Sensor

NASA Astrophysics Data System (ADS)

El Hadi, Kacem; Vignaux, Mael; Fusco, Thierry

2013-12-01

Within the framework of the E-ELT studies, several laboratories are involved on some instruments: HARMONY with its ATLAS adaptive optics [AO] system, EAGLE or EPICS. Most of the AO systems will probably integrate one or several pyramidal wavefront sensors, PWFS (R. Ragazzoni [1]). The coupling in an AO loop and the control in laboratory (then on sky) of this type of sensor is fundamental for the continuation of the projects related to OA systems on the E-ELT. LAM (Laboratory of Astrophysics of Marseille) is involved in particular in the VLT-SPHERE, ATLAS, EPICS projects. For the last few years, our laboratory has been carrying out different R&D activities in AO instrumentation for ELTs. An experimental AO bench is designed and being developed to allow the validation of new wave-front sensing and control concepts [2]. One the objectives of this bench, is the experimental validation of a pyramid WFS. Theoretical investigations on its behavior have been already made. The world's fastest and most sensitive camera system (OCAM2) has been recently developed at LAM (J.L Gach [3], First Light Imaging). Conjugating this advantage with the pyramid concept, we plan to demonstrate a home made Pyramid sensor for Adaptive Optics whose the speed and the precision are the key points. As a joint collaboration with ONERA and Shaktiware, our work aims at the optimization (measurement process, calibration and operation) in laboratory then on the sky of a pyramid sensor dedicated to the first generation instruments for ELTs. The sensor will be implemented on the ONERA ODISSEE AO bench combining thus a pyramid and a Shack-Hartmann wavefront sensors. What would give the possibility to compare strictly these two WFS types and make this bench unique in France and even in Europe. Experimental work on laboratory demonstration is undergoing. The status of our development will presented at the conference.

Micro-device for coupling, multiplexing and demultiplexing using elliptical-core two-mode fiber

NASA Technical Reports Server (NTRS)

Wang, A.; Murphy, K. A.; Wang, G. Z.; Vengsarkar, A. M.; Claus, R. O.

1990-01-01

We propose and demonstrate experimentally a fiber optic micro-device that is capable of tunably splitting, multiplexing, and demultiplexing optical signals using elliptical-core two-mode optical fiber. A crosstalk of 15 dB with an insertion loss of 1.2 dB was obtained.

InfoSec-MobCop - Framework for Theft Detection and Data Security on Mobile Computing Devices

NASA Astrophysics Data System (ADS)

Gupta, Anand; Gupta, Deepank; Gupta, Nidhi

People steal mobile devices with the intention of making money either by selling the mobile or by taking the sensitive information stored inside it. Mobile thefts are rising even with existing deterrents in place. This is because; they are ineffective, as they generate unnecessary alerts and might require expensive hardware equipments. In this paper a novel framework termed as InfoSec-MobCop is proposed which secures a mobile user’s data and discovers theft by detecting any anomaly in the user behavior. The anomaly of the user is computed by extracting and monitoring user specific details (typing pattern and usage history). The result of any intrusion attempt by a masquerader is intimated to the service provider through an SMS. Effectiveness of the used approach is discussed using FAR and FRR graphs. The experimental system uses both real users and simulated studies to quantify the effectiveness of the InfoSec-MobCop (Information Security Mobile Cop).

Social-bond strength influences vocally mediated recruitment to mobbing

PubMed Central

2016-01-01

Strong social bonds form between individuals in many group-living species, and these relationships can have important fitness benefits. When responding to vocalizations produced by groupmates, receivers are expected to adjust their behaviour depending on the nature of the bond they share with the signaller. Here we investigate whether the strength of the signaller–receiver social bond affects response to calls that attract others to help mob a predator. Using field-based playback experiments on a habituated population of wild dwarf mongooses (Helogale parvula), we first demonstrate that a particular vocalization given on detecting predatory snakes does act as a recruitment call; receivers were more likely to look, approach and engage in mobbing behaviour than in response to control close calls. We then show that individuals respond more strongly to these recruitment calls if they are from groupmates with whom they are more strongly bonded (those with whom they preferentially groom and forage). Our study, therefore, provides novel evidence about the anti-predator benefits of close bonds within social groups. PMID:27903776

[The MMPI-2 test in the evaluation of the mobbing syndrome].

PubMed

Pappone, P; Santalucia, L; Del Castello, E; De Maino, V; Garofalo, E; Cappelluccio, R; Feola, D; Ruberto, M; Liotti, F

2007-01-01

MMPI-2 test is widely used in psychodiagnostic evaluation as well as in the evaluation of psychic pathologies related to psychosocial adversative events in working activities. A more efficacious use of MMPI-2 test in the working context can be achieved by the individuation of indexes able to facilitate the evaluation of mobbing syndrome. This work is based on the analysis of 150 cases (39.7% women and 60.7% men, 30 to 60 years of age), evaluated through an accurate examination of working history and a series of clinic conversations, followed by psychodiagnostic evaluation. The average of T-scores on the clinical scale, the content scale, the PK addition scale and the validation scale were calculated from tests. Pathologic high T-scores on the scales Hs, D. Hy e Pa were found in subjects having positive mobbing anamnesis. These results strongly indicate the presence of clinical specificities in workers exposed to working harassments, and that these specificities can be efficaciously evidenced by the MMPI-2 test.

Optical studies in the holographic ground station

NASA Technical Reports Server (NTRS)

Workman, Gary L.

1991-01-01

The Holographic Group System (HGS) Facility in rooms 22 & 123, Building 4708 has been developed to provide for ground based research in determining pre-flight parameters and analyzing the results from space experiments. The University of Alabama, Huntsville (UAH) has researched the analysis aspects of the HGS and reports their findings here. Some of the results presented here also occur in the Facility Operating Procedure (FOP), which contains instructions for power up, operation, and powerdown of the Fluid Experiment System (FES) Holographic Ground System (HGS) Test Facility for the purpose of optically recording fluid and/or crystal behavior in a test article during ground based testing through the construction of holograms and recording of videotape. The alignment of the optical bench components, holographic reconstruction and and microscopy alignment sections were also included in the document for continuity even though they are not used until after optical recording of the test article) setup of support subsystems and the Automated Holography System (AHS) computer. The HGS provides optical recording and monitoring during GCEL runs or development testing of potential FES flight hardware or software. This recording/monitoring can be via 70mm holographic film, standard videotape, or digitized images on computer disk. All optical bench functions necessary to construct holograms will be under the control of the AHS personal computer (PC). These include type of exposure, time intervals between exposures, exposure length, film frame identification, film advancement, film platen evacuation and repressurization, light source diffuser introduction, and control of realtime video monitoring. The completed sequence of hologram types (single exposure, diffuse double exposure, etc.) and their time of occurrence can be displayed, printed, or stored on floppy disk posttest for the user.

Development of a Compact Optical-MEMS Scanner with Integrated VCSEL Light Source and Diffractive Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krygowski, Thomas W.; Reyes, David; Rodgers, M. Steven

1999-06-30

In this work the design and initial fabrication results are reported for the components of a compact optical-MEMS laser scanning system. This system integrates a silicon MEMS laser scanner, a Vertical Cavity Surface Emitting Laser (VCSEL) and passive optical components. The MEMS scanner and VCSEL are mounted onto a fused silica substrate which serves as an optical interconnect between the devices. Two Diffractive Optical Elements (DOEs) are etched into the fused silica substrate to focus the VCSEL beam and increase the scan range. The silicon MEMS scanner consists of an actuator that continuously scans the position of a large polysiliconmore » gold-coated shuttle containing a third DOE. Interferometric measurements show that the residual stress in the 500 {micro}m x 1000 {micro}m shuttle is extremely low, with a maximum deflection of only 0.18{micro}m over an 800 {micro}m span for an unmetallized case and a deflection of 0.56{micro}m for the metallized case. A conservative estimate for the scan range is {approximately}{+-}4{degree}, with a spot size of about 0.5 mm, producing 50 resolvable spots. The basic system architecture, optical and MEMS design is reported in this paper, with an emphasis on the design and fabrication of the silicon MEMS scanner portion of the system.« less

Optical Testing of Diamond Machined, Aspheric Mirrors for Groundbased, Near-IR Astronomy

NASA Technical Reports Server (NTRS)

Chambers, V. John; Mink, Ronald G.; Ohl, Raymond G.; Connelly, Joseph A.; Mentzell, J. Eric; Arnold, Steven M.; Greenhouse, Matthew A.; Winsor, Robert S.; MacKenty, John W.

2002-01-01

The Infrared Multi-Object Spectrometer (IRMOS) is a facility-class instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8-2.5 micron) spectrometer and operates at approximately 80 K. The 6061-T651 aluminum bench and mirrors constitute an athermal design. The instrument produces simultaneous spectra at low- to mid-resolving power (R=lambda/delta lambda= 300-3000) of approximately 100 objects in its 2.8 x 2.0 arcmin field. We describe ambient and cryogenic optical testing of the IRMOS mirrors across a broad range in spatial frequency (figure error, mid-frequency error, and microroughness). The mirrors include three rotationally symmetric, off-axis conic sections, one off-axis biconic, and several flat fold mirrors. The symmetric mirrors include convex and concave prolate and oblate ellipsoids. They range in aperture from 94x86 mm to 286x269 mm and in f-number from 0.9 to 2.4. The biconic mirror is concave and has a 94x76 mm aperture, R(sub x)=377 mm, k(sub x)=0.0778, R(sub y)=407 mm, and k(sub y)=0.1265 and is decentered by -2 mm in X and 227 mm in Y. All of the mirrors have an aspect ratio of approximately 6:1. The surface error fabrication tolerances are less than 10 nm RMS microroughness, 'best effort' for mid-frequency error, and less than 63.3 nm RMS figure error. Ambient temperature (approximately 293 K) testing is performed for each of the three surface error regimes, and figure testing is also performed at approximately 80 K. Operation of the ADE Phaseshift MicroXAM white light interferometer (micro-roughness) and the Bauer Model 200 profilometer (mid-frequency error) is described. Both the sag and conic values of the aspheric mirrors make these tests challenging. Figure testing is performed using a Zygo GPI interferometer, custom computer generated holograms (CGH), and optomechanical alignment fiducials. Cryogenic CGH null testing is discussed in detail. We discuss complications such as the change in prescription with temperature and thermal gradients. Correction for the effect of the dewar window is also covered. We discuss the error budget for the optical test and alignment procedure. Data reduction is accomplished using commercial optical design and data analysis software packages. Results from CGH testing at cryogenic temperatures are encouraging thus far.

Fabrication of Fresnel micro lens array in borosilicate glass by F2-laser ablation for glass interposer application

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning; Fricke-Begemann, Thomas; Ihlemann, Jürgen

2014-03-01

The future need for more bandwidth forces the development of optical transmission solutions for rack-to-rack, boardto- board and chip-to-chip interconnects. The goals are significant reduction of power consumption, highest density and potential for bandwidth scalability to overcome the limitations of the systems today with mostly copper based interconnects. For system integration the enabling of thin glass as a substrate material for electro-optical components with integrated micro-optics for efficient light coupling to integrated optical waveguides or fibers is becoming important. Our glass based packaging approach merges micro-system packaging and glass integrated optics. This kind of packaging consists of a thin glass substrate with integrated micro lenses providing a platform for photonic component assembly and optical fiber or waveguide interconnection. Thin glass is commercially available in panel and wafer size and characterizes excellent optical and high frequency properties. That makes it perfect for microsystem packaging. A suitable micro lens approach has to be comparable with different commercial glasses and withstand post-processing like soldering. A benefit of using laser ablated Fresnel lenses is the planar integration capability in the substrate for highest integration density. In the paper we introduce our glass based packaging concept and the Fresnel lens design for different scenarios like chip-to-fiber, chip-to-optical-printed-circuit-board coupling. Based on the design the Fresnel lenses were fabricated by using a 157 nm fluorine laser ablation system.

Grinding aspheric and freeform micro-optical molds

NASA Astrophysics Data System (ADS)

Tohme, Yazid E.

2007-02-01

Fueled by the need for better performing optics, glass optics are now replacing plastic optics in many industrial and consumer electronic devices. One of these devices is the mobile phone camera. The optical sub-assembly in a mobile phone includes several micro lenses that are spherical and/or aspherical in shape and require form tolerances in the submicron range. These micro glass lenses are mass produced by a replication process known as glass press molding. The process entails the compression of a glass gob between two precise optical quality molds at an elevated temperature, usually near the transition temperature of the glass material. The elevated forces and temperatures required in the glass molding process limits the materials of the molds to very tough materials such as tungsten carbide or silicon carbide. These materials can withstand large pressing forces at high temperatures without any significant deformation. These materials offer great mechanical properties for glass press molding but they are also a challenge to machine to submicron accuracy. The work in this paper discusses a deterministic micro grinding manufacturing process referred to as wheel normal grinding, which is utilized to produce these optical quality molds. Wheel normal grinding is more accurate and more deterministic than most other grinding techniques and can produce molds to the form and finish tolerances required for optical molding. This method relies on the ability to recognize and compensate for grinding wheel wear and machine repeatable errors. Results will be presented to illustrate the accuracy of this micro grinding technique.

Interactions between Thaumarchaea, Nitrospira and methanotrophs modulate autotrophic nitrification in volcanic grassland soil

PubMed Central

Daebeler, Anne; Bodelier, Paul LE; Yan, Zheng; Hefting, Mariet M; Jia, Zhongjun; Laanbroek, Hendrikus J

2014-01-01

Ammonium/ammonia is the sole energy substrate of ammonia oxidizers, and is also an essential nitrogen source for other microorganisms. Ammonia oxidizers therefore must compete with other soil microorganisms such as methane-oxidizing bacteria (MOB) in terrestrial ecosystems when ammonium concentrations are limiting. Here we report on the interactions between nitrifying communities dominated by ammonia-oxidizing archaea (AOA) and Nitrospira-like nitrite-oxidizing bacteria (NOB), and communities of MOB in controlled microcosm experiments with two levels of ammonium and methane availability. We observed strong stimulatory effects of elevated ammonium concentration on the processes of nitrification and methane oxidation as well as on the abundances of autotrophically growing nitrifiers. However, the key players in nitrification and methane oxidation, identified by stable-isotope labeling using 13CO2 and 13CH4, were the same under both ammonium levels, namely type 1.1a AOA, sublineage I and II Nitrospira-like NOB and Methylomicrobium-/Methylosarcina-like MOB, respectively. Ammonia-oxidizing bacteria were nearly absent, and ammonia oxidation could almost exclusively be attributed to AOA. Interestingly, although AOA functional gene abundance increased 10-fold during incubation, there was very limited evidence of autotrophic growth, suggesting a partly mixotrophic lifestyle. Furthermore, autotrophic growth of AOA and NOB was inhibited by active MOB at both ammonium levels. Our results suggest the existence of a previously overlooked competition for nitrogen between nitrifiers and methane oxidizers in soil, thus linking two of the most important biogeochemical cycles in nature. PMID:24858784

On-chip photonic tweezers for photonics, microfluidics, and biology

NASA Astrophysics Data System (ADS)

Pin, Christophe; Renaut, Claude; Tardif, Manon; Jager, Jean-Baptiste; Delamadeleine, Eric; Picard, Emmanuel; Peyrade, David; Hadji, Emmanuel; de Fornel, Frédérique; Cluzel, Benoît

2017-04-01

Near-field optical forces arise from evanescent electromagnetic fields and can be advantageously used for on-chip optical trapping. In this work, we investigate how evanescent fields at the surface of photonic cavities can efficiently trap micro-objects such as polystyrene particles and bacteria. We study first the influence of trapped particle's size on the trapping potential and introduce an original optofluidic near-field optical microscopy technique. Then we analyze the rotational motion of trapped clusters of microparticles and investigate their possible use as microfluidic micro-tools such as integrated micro-flow vane. Eventually, we demonstrate efficient on-chip optical trapping of various kinds of bacteria.

Polymer microfiber bridging Bi-tapered refractive index sensor based on evanescent field

NASA Astrophysics Data System (ADS)

Lv, Ri-Qing; Wang, Qi; Wang, Bo-Tao; Liu, Yu; Kong, Lingxin

2018-05-01

A PDMS/graphene enhanced PMMA micro optical waveguide sensor is reported in terms of fabrication method and optical characteristics. The micro optical waveguide with a diameter of 6 μm and a length of 800 μm is used as the sensing probe to realize refractive index (RI) measurement suspended in NaCl solutions with different concentrations. Experimental results show that the refractive index sensing sensitivity can reach 2027.97 nm/RIU within the refractive index ranging from 1.3333-1.3426. Research results show that PMMA/graphene micro optical waveguide doped with PDMS is an excellent high sensitive sensing technology in refractive index detection field.

Holographic optical tweezers for object manipulations at an air-liquid surface.

PubMed

Jesacher, Alexander; Fürhapter, Severin; Maurer, Christian; Bernet, Stefan; Ritsch-Marte, Monika

2006-06-26

We investigate holographic optical tweezers manipulating micro-beads at a suspended air-liquid interface. Axial confinement of the particles in the two-dimensional interface is maintained by the interplay between surface tension and gravity. Therefore, optical trapping of the micro-beads is possible even with a long distance air objective. Efficient micro-circulation of the liquid can be induced by fast rotating beads, driven by the orbital angular momentum transfer of incident Laguerre-Gaussian (doughnut) laser modes. Our setup allows various ways of creating a tailored dynamic flow of particles and liquid within the surface. We demonstrate examples of surface manipulations like efficient vortex pumps and mixers, interactive particle flow steering by arrays of vortex pumps, the feasibility of achieving a "clocked" traffic of micro beads, and size-selective guiding of beads along optical "conveyor belts".

Fabrication of polymer microlenses on single mode optical fibers for light coupling

NASA Astrophysics Data System (ADS)

Zaboub, Monsef; Guessoum, Assia; Demagh, Nacer-Eddine; Guermat, Abdelhak

2016-05-01

In this paper, we present a technique for producing fibers optics micro-collimators composed of polydimethylsiloxane PDMS microlenses of different radii of curvature. The waist and working distance values obtained enable the optimization of optical coupling between optical fibers, fibers and optical sources, and fibers and detectors. The principal is based on the injection of polydimethylsiloxane (PDMS) into a conical micro-cavity chemically etched at the end of optical fibers. A spherical microlens is then formed that is self-centered with respect to the axis of the fiber. Typically, an optimal radius of curvature of 10.08 μm is obtained. This optimized micro-collimator is characterized by a working distance of 19.27 μm and a waist equal to 2.28 μm for an SMF 9/125 μm fiber. The simulation and experimental results reveal an optical coupling efficiency that can reach a value of 99.75%.

Performance analysis and material dependence of micro holographic optical elements as couplers for fiber optic communication

NASA Astrophysics Data System (ADS)

Ambadiyil, Sajan; Prasannan, G.; Sathyan, Jithesh; Ajith Kumar, P. T.

2005-01-01

Holographic Optical Elements (HOEs) are gaining much importance and finding newer and better applications in areas of optical fiber communication and optical information processing systems. In contrast to conventional HOEs, optical communication and information systems require smaller and efficient elements of desired characteristics and transfer functions. Such Micro Holographic Optical Elements (MHOEs) can either be an HOE, recorded with two narrow beams of laser light or a segment cut from a larger HOE (SHOEs), and recorded in the conventional manner. In this study, micro holographic couplers, having specific focusing and diffraction characteristics were recorded in different holographic recording media such as silver halide and dichromated gelatin. Wavelength response of the elements was tested at 633 nm and 442 nm. Variation in diffraction efficiency/coupling factor, and insertion loss of the elements were studied. The paper reports in detail about the above results and related design considerations.

Local variations in bone mineral density: a comparison of OCT versus x-ray micro-CT

NASA Astrophysics Data System (ADS)

Ugryumova, Nadya; Stevens-Smith, Jenna; Scutt, Andrew; Matcher, Stephen J.

2008-02-01

We describe variations in the degree of mineralisation within the subchondral bone plate of the equine metacarpophalangeal joint. A comparison of Optical Coherence Tomography, Micro CT, and SEM techniques was performed. These data are compared between sites on a healthy sample and at points on an osteoarthritically degenerated sample. No significant correlation was found between the optical scattering coefficient and the micro-CT derived BMD for comparisons between different sites on the bone surface. Also OCT demonstrated a larger regional variation in scattering coefficient than did micro CT for bone mineral density. This suggests that the optical scattering coefficient of bone is not related solely to the volume-density of calcium-phosphate. Patches of lower optical scattering coefficient were found in the bone structure that was related to the osteoarthritic lesion area on the overlying cartilage. Areas of microcracking, as revealed by both SEM and micro CT produced distinctive granularity in the OCT images. In further experiments, OCT was compared with micro CT and mechanical strength testing (3-point bending) in a small animal model of cardiovascular disease (cholesterol overload in mice). In the cardiovascular diseased mice, micro-CT of the trabecular bone did not demonstrate a significant change in trabecular bone mineral density before and after administration of the high cholesterol diet. However mechanical testing demonstrated a decrease in mechanical strength and OCT demonstrated a corresponding statistically significant decrease in optical scattering of the bone.

High Precision Method of Measuring the Velocity of Sound With Simple Apparatus

ERIC Educational Resources Information Center

Hansen, Russell C.

1975-01-01

A capacitor is discharged to generate an acoustical pulse and start a digital counter which is stopped by a microphone. Differences are accurately measured by positioning the sensing microphone on an optical bench. Results are discussed and extended experiments are suggested. The sources of some components are given. (GH)

Compilation and Preliminary Analysis of Sensitivity Data for Pyrotechnics. Phase 1

DTIC Science & Technology

1975-05-01

700-2, except Green smoke (sulfur based) and match head Mix VI which were tested 6 and 11 times respectively. Optical pyrometer measurements of the...Photographic estimates indicated that an acoustic wave was formed during dust cloud fireball growth. 17 2. 2.3.11.5 Jet Airmix Blending. Bench

A Precision Metrology System for the Hubble Space Telescope Wide Field Camera 3 Instrument

NASA Technical Reports Server (NTRS)

Toland, Ronald W.

2003-01-01

The Wide Field Camera 3 (WFC3) instrument for the Hubble Space Telescope (HST) will replace the current Wide Field and Planetary Camera 2 (WFPC2). By providing higher throughput and sensitivity than WFPC2, and operating from the near-IR to the near-UV, WFC3 will once again bring the performance of HST above that from ground-based observatories. Crucial to the integration of the WFC3 optical bench is a pair of 2-axis cathetometers used to view targets which cannot be seen by other means when the bench is loaded into its enclosure. The setup and calibration of these cathetometers is described, along with results from a comparison of the cathetometer system with other metrology techniques.

Polarization independent polymer waveguide tunable receivers incorporating a micro-optic circulator

NASA Astrophysics Data System (ADS)

Wu, Xiaoping; Park, Tae-Hyun; Park, Su-Hyun; Seo, Jun-Kyu; Oh, Min-Cheol

2018-06-01

In order to simplify the receiver configuration in a wavelength division multiplexed optical fiber network, compact wavelength tunable filters have long been expected to be used as channel selectors. Bragg reflector inherently has the most suitable reflection spectrum for filtering a single wavelength from the densely multiplexed wavelength signal. Polymer has high thermo-optic coefficient and good thermal insulation property compared to the other optical waveguide materials such as silicon and silica materials. This can be used to broadly tune the reflection spectrum of Bragg reflector using a simple micro-heater. In this work, a micro-optic circulator component and a polymeric Bragg reflector device are assembled to produce a small form factor tunable receiver. Compared to the integrated-optical versions, the micro-optics are based on well-developed manufacturing processes and can achieve competitive production yields. The device exhibits high reflectivity with a flat top passband, and a polarization dependence of 0.06 nm achieved by virtue of the low birefringence of LFR polymer, which make a significant contribution to the implementation of polarization independent tunable receiver. The wavelength tuning range of 40 nm is demonstrated by using a bottom located heater with a groove for heat isolation.

Micromachined edge illuminated optically transparent automotive light guide panels

NASA Astrophysics Data System (ADS)

Ronny, Rahima Afrose; Knopf, George K.; Bordatchev, Evgueni; Tauhiduzzaman, Mohammed; Nikumb, Suwas

2012-03-01

Edge-lit backlighting has been used extensively for a variety of small and medium-sized liquid crystal displays (LCDs). The shape, density and spatial distribution pattern of the micro-optical elements imprinted on the surface of the flat light-guide panel (LGP) are often "optimized" to improve the overall brightness and luminance uniformity. A similar concept can be used to develop interior convenience lighting panels and exterior tail lamps for automotive applications. However, costly diffusive sheeting and brightness enhancement films are not be considered for these applications because absolute luminance uniformity and the minimization of Moiré fringe effects are not significant factors in assessing quality of automotive lighting. A new design concept that involves micromilling cylindrical micro-optical elements on optically transparent plastic substrates is described in this paper. The variable parameter that controls illumination over the active regions of the panel is the depth of the individual cylindrical micro-optical elements. LightTools™ is the optical simulation tool used to explore how changing the micro-optical element depth can alter the local and global luminance. Numerical simulation and microfabrication experiments are performed on several (100mmx100mmx6mm) polymethylmethacrylate (PMMA) test samples in order to verify the illumination behavior.

An Optically Accessible Pyrolysis Microreactor

NASA Astrophysics Data System (ADS)

Baraban, Joshua H.; David, Donald E.; Ellison, Barney; Daily, John W.

2016-06-01

We report an optically accessible pyrolysis micro-reactor suitable for in situ laser spectroscopic measurements. A radiative heating design allows for completely unobstructed views of the micro-reactor along two axes. The maximum temperature demonstrated here is only 1300 K (as opposed to 1700 K for the usual SiC micro-reactor) because of the melting point of fused silica, but alternative transparent materials will allow for higher temperatures. Laser induced fluorescence measurements on nitric oxide are presented as a proof of principle for spectroscopic characterization of pyrolysis conditions. (This work has been published in J. H. Baraban, D. E. David, G. B. Ellison, and J. W. Daily. An Optically Accessible Pyrolysis Micro-Reactor. Review of Scientific Instruments, 87(1):014101, 2016.)

Development of a micro-X-ray fluorescence system based on polycapillary X-ray optics for non-destructive analysis of archaeological objects

NASA Astrophysics Data System (ADS)

Cheng, Lin; Ding, Xunliang; Liu, Zhiguo; Pan, Qiuli; Chu, Xuelian

2007-08-01

A new micro-X-ray fluorescence (micro-XRF) system based on rotating anode X-ray generator and polycapillary X-ray optics has been set up in XOL Lab, BNU, China, in order to be used for analysis of archaeological objects. The polycapillary X-ray optics used here can focus the primary X-ray beam down to tens of micrometers in diameter that allows for non-destructive and local analysis of sub-mm samples with minor/trace level sensitivity. The analytical characteristics and potential of this micro-XRF system in archaeological research are discussed. Some described uses of this instrument include studying Chinese ancient porcelain.

Ultra-precise micro-motion stage for optical scanning test

NASA Astrophysics Data System (ADS)

Chen, Wen; Zhang, Jianhuan; Jiang, Nan

2009-05-01

This study aims at the application of optical sensing technology in a 2D flexible hinge test stage. Optical fiber sensor which is manufactured taking advantage of the various unique properties of optical fiber, such as good electric insulation properties, resistance of electromagnetic disturbance, sparkless property and availability in flammable and explosive environment, has lots of good properties, such as high accuracy and wide dynamic range, repeatable, etc. and is applied in 2D flexible hinge stage driven by PZT. Several micro-bending structures are designed utilizing the characteristics of the flexible hinge stage. And through experiments, the optimal micro-bending tooth structure and the scope of displacement sensor trip under this optimal micro-bending tooth structure are derived. These experiments demonstrate that the application of optical fiber displacement sensor in 2D flexible hinge stage driven by PZT substantially broadens the dynamic testing range and improves the sensitivity of this apparatus. Driving accuracy and positioning stability are enhanced as well. [1,2

Direct laser writing for micro-optical devices using a negative photoresist.

PubMed

Tsutsumi, Naoto; Hirota, Junichi; Kinashi, Kenji; Sakai, Wataru

2017-12-11

Direct laser writing (DLW) via two-photon absorption (TPA) has attracted much attention as a new microfabrication technique because it can be applied to fabricate complex, three-dimensional (3D) microstructures. In this study, 3D microstructures and micro-optical devices of micro-lens array on the micrometer scale are fabricated using the negative photoresist SU-8 through TPA with a femtosecond laser pulse under a microscope. The effects of the irradiation conditions on linewidths, such as laser power, writing speed, and writing cycles (a number of times a line is overwritten), are investigated before the fabrication of the 3D microstructures. Various microstructures such as woodpiles, hemisphere and microstructures, 3D micro-lens and micro-lens array for micro-optical devices are fabricated. The shape of the micro-lens is evaluated using the shape analysis mode of a laser microscope to calculate the working distance of the fabricated micro-lenses. The calculated working distance corresponds well to the experimentally measured value. The focusing performance of the fabricated micro-lens is confirmed by the TPA fluorescence of an isopropyl thioxanthone (ITX) ethanol solution excited by a Ti:sapphire femtosecond laser at 800 nm. Micro-lens array (assembled 9 micro-lenses) are fabricated. Nine independent woodpile structures are simultaneously manufactured by DLW via TPA to confirm the multi-focusing ability using the fabricated micro-lens array.

A heterodyne interferometer for high resolution translation and tilt measurement as optical readout for the LISA inertial sensor

NASA Astrophysics Data System (ADS)

Schuldt, Thilo; Kraus, Hans-Jürgen; Weise, Dennis; Braxmaier, Claus; Peters, Achim; Johann, Ulrich

2017-11-01

The space-based gravitational wave detector LISA (Laser Interferometer Space Antenna) requires a high performance position sensor in order to measure the translation and tilt of the free flying test mass with respect to the LISA optical bench. Here, we present a mechanically highly stable and compact setup of a heterodyne interferometer combined with differential wavefront sensing for the tilt measurement which serves as a demonstrator for an optical readout of the LISA test mass position. First results show noise levels below 1 nm/√Hz and 1 μrad/√Hz, respectively, for frequencies < 10-3 Hz.

The Integration Process of Very Thin Mirror Shells with a Particular Regard to Simbol-X

NASA Astrophysics Data System (ADS)

Basso, S.; Pareschi, G.; Tagliaferri, G.; Mazzoleni, F.; Valtolina, R.; Citterio, O.; Conconi, P.

2009-05-01

The optics of Simbol-X are very thin compared to previous X-ray missions (like XMM). Therefore their shells floppy and are unable to maintain the correct shape. To avoid the deformations of their very thin X-ray optics during the integration process we adopt two stiffening rings with a good roundness. In this article the procedure used for the first three prototypes of the Simbol-X optics is presented with a description of the problems involved and with an analysis of the degradation of the performances during the integration. This analysis has been performed with the UV vertical bench measurements at INAF-OAB.

Investigation of optical information for a single micro grating device combined with MATA by SMart process

NASA Astrophysics Data System (ADS)

Tsai, Chien-Chung; Huang, Yi-Chao; Yang, Tsa-Hsien; Chen, Jen-Chieh

2006-01-01

The concentric circles type and saw-tooth type of micro grating device based upon the diffraction theory are proposed in this study. The geometry dimension of micro optical device is 200 × 200 μm2, the interval of grating is 4 μm, and the depth is 0.75 μm. The Micro Array Thermal Actuator, MATA, is applied to drive the micro grating device, and the pre-elevating structure is designed to lift the micro grating device by the residual stress of polysilicon combined with metal. The micro grating device is fabricated by Surface Micromachining for applications and research technology platform, SMart, common process. The incident ray of He-Ne laser focused by a lens which focal length is 250 mm is applied to be the light source for the experiment, and then analyzes the optical information of the outgoing ray. From the experimental results, the basic optical features are examined based upon the concentric circles type and saw-tooth type of micro grating device, respectively. The outgoing ray angle of central spot is 60° in theory. The measurements are 59.475° for the concentric circles type and 59.88° for the saw-tooth type. The outgoing ray angle of the first stripe is 46.9° in theory, and 46.81° for the concentric circles type and 46.67° for the saw-tooth type are measured from the experiment. The variation of outgoing ray angle is smaller than 1% compared the measurement results with theory of diffraction on the central spot and first stripe characteristics. The work successfully demonstrates the micro grating device with highly accurate performance by the verification of optical information. All of the efforts will be contributed to Controlled Blazed Diffraction micro grating device, CBDMG, and that will be the main device of Integrate Opto-Electronics applied on display to develop in the future.