Localization of fixed dipoles at high precision by accounting for sample drift during illumination

Single molecule localization microscopy relies on the precise quantification of the position of single dye emitters in a sample. This precision is improved by the number of photons that can be detected from each molecule. It is therefore recommendable to increase illumination times for the recording process. Particularly recording at cryogenic temperatures dramatically reduces photobleaching and thereby allows a massive increase in illumination times to several seconds. As a downside, microscope instabilities may well introduce jitter during such long illuminations, deteriorating the localization precision. In this paper, we theoretically demonstrate that a parallel recording of fiducial marker beads together with a novel fitting approach accounting for the full drift trajectory allows for largely eliminating drift effects for drift magnitudes of several hundred nanometers per frame.Comment: 12 pages, 7 figure

Spatially resolved spectroscopy of Cassiopeia A with MECS on board BeppoSAX

We have performed the first detailed spatially resolved spectroscopy of Cas A in the 1.6-10 keV energy range, using data taken with the MECS spectrometer on board the BeppoSAX Observatory. We performed a spatial deconvolution of the data and eventually generated a set of spectra, covering a region of about 3 arcmin radius around the centre of Cas A. The results obtained by fitting these spectra using a non-equilibrium ionisation plasma model and a power law, are: (i) a single thermal component is sufficient to fit all the spectra; (ii) kT is rather uniformly distributed with a minimum in the east and a maximum in the west, and no evidence is found for high kT expected from the interaction of the main shock with the ISM; (iii) from the distribution of the values of the ionisation parameter n_et we infer the presence of two distinct components: the first (a) in the range 1-10 cm^(-3), the second (b) with values ten times higher; if we associate component a to the CSM and component b to the ejecta, the mass ratio M(a)/M(b)<= 1/10 indicates a progenitor star that lost only a small fraction of the envelope during its pre-SN life. In this hypothesis the distribution of component b across the remnant suggests that the explosion was not spherically symmetric; (iv) the distribution of abundances indicates that we are detecting a CSM component with almost solar composition, and an ejecta component enriched in heavier elements. Abundances found for alpha-elements are consistent with the current view that Cas A was produced by the explosion of a massive star.Comment: 16 pages, 9 PostScript figures, 4 tables, Accepted for publication on Astronomy & Astrophysics (submitted July 12, 2000; accepted December 20, 2000

Design and experimental results of small-scale rotary engines

ABSTRACT A research project is currently underway to develop small-scale internal combustion engines fueled by liquid hydrocarbons. The ultimate goal of the MEMS Rotary Internal Combustion Engine Project is to develop a liquid hydrocarbon fueled MEMS-size rotary internal combustion micro-engine capable of delivering power on the order of milli-watts. This research is part of a larger effort to develop a portable, autonomous power generation system with an order of magnitude improvement in energy density over alkaline or lithium-ion batteries. The rotary (Wankel-type) engine is well suited for the fabrication techniques developed in the integrated chip (IC) community and refined by the MicroElectroMechanical Systems (MEMS) field. Features of the rotary engine that lend itself to MEMS fabrication are its planar construction, high specific power, and self-valving operation. The project aims at developing a &quot;micro-rotary&quot; engine with an 3 epitrochoidal-shaped housing under 1 mm in size and with a rotor swept volume of 0.08 mm 3. To investigate engine behavior and design issues, larger-scale &quot;mini-rotary&quot; engines have been fabricated from steel. Mini-rotary engine chambers are approximately 1000 mm 3 to 1700 mm 3 in size and their displacements range from 78 mm 3 to 348 mm 3. A test bench for the mini-rotary engine has been developed and experiments have been conducted with gaseous-fueled mini-rotary engines to examine the effects of sealing, ignition, design, and thermal management on efficiency. Preliminary testing has shown net power output of up to 2.7 W at 9300 RPM. Testing has been performed using hydrogen-air mixtures and a range of spark and glow plug designs as the ignition source. Iterative design and testing of the miniengine has lead to improved sealing designs. These particular designs are such that they can be incorporated into the fabrication of the micro-engine. Design and fabrication of a first generation meso-scale rotary engine has been completed using a SiC molding process developed at Case Western Reserve University. The fabrication of the micro-rotary engine is being conducted in U.C. Berkeley&apos;s Microfabrication Laboratory. Testing of the mini-engine has lead to the conclusion that there are no fundamental phenomena that would prevent the operation of the micro-engine. However, heat loss and sealing issues are key for efficient operation of the micro-engine, and they must be taken into account in the design and fabrication of the micro-rotary engine. The mini-rotary engine design, testing, results and applications will be discussed in this paper

The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

AD8-Argentina questionnaire to detect dementia in primary health care

Memory complaint may be very common in elderly people over 65, but also is present in early stage of dementing processes. Instruments to detect dementia in primary health care must be easy and quickly to be applied. In 2005, Galvin et al. developed a questionnaire Alzheimer's Disease 8 (AD8) which was based on a brief interview with and informant to detect subjects with dementia. The objective of this work was to perform the translation, adaptation to the Spanish language near the Rio de la Plata and to establish the validity, reliability and discriminative proprieties of AD8-arg for use in primary care. Methods 18 patients with dementia of Alzheimer type, 25 with mild cognitive impairment and 19 normal controls matched by age and education were assessed with the AD8-arg and an extensive neuropsychological battery. Concurrent validity was strong with significant correlation with MMSE (-0,464: P<0.001) and CDR (0,514; P<0.001). Internal consistency was adequate correlating with all cognitive tests. The area under the ROC curve was 0.89 and a cutoff score of 2 had a sensitivity of 0.80 and specificity of 0.83 showing excellent discrimination between demented and non-demented patients. The AD8-arg is a tool for quick and easy administration with adequate psychometric properties for use in screening of dementia in primary care in our region.Existe una gran cantidad de personas mayores de 65 años que consultan por falta de memoria, la cual puede ser muy frecuente en el curso del envejecimiento normal, pero también está en las etapas iniciales de procesos demenciales. Debido a esto, se debe contar con instrumentos de detección de estas enfermedades que puedan ser aplicados de manera fácil y rápida en espacios de Atención Primaria de la salud. En el año 2005, Galvin et al. desarrollaron el cuestionario Alzheimer Disease 8 (AD8), el cual está basado en una breve entrevista a un informante para detectar sujetos con demencia. El objetivo del presente trabajo es realizar la adaptación al español rioplatense y validación de este instrumento (AD8-arg) para ser utilizado en asistencia primaria. Fueron evaluados con este instrumento y con una extensa batería cognitiva 18 pacientes con demencia tipo Alzheimer, 25 con deterioro cognitivo leve y 19 controles normales apareados por edad y escolaridad. El AD8-arg tuvo una alta validez convergente con una significativa correlación con el MMSE (–0,464; p < 0,001) y el CDR (0,514; p < 0,001). La consistencia interna fue adecuada correlacionando con todas las pruebas cognitivas. El área bajo la curva ROC del cuestionario fue 0,89 y con un puntaje de corte de 2 tuvo una sensibilidad 0,80 y una especificidad de 0,83 para detectar demencias. El AD8-arg es un instrumento de rápida y fácil administración con adecuadas propiedades psicométricas para ser usado en detección de demencia en asistencia primaria en nuestro medio

An ISOCAM survey through gravitationally lensing galaxy clusters

ISOCAM was used to perform a deep survey through three gravitationally lensing clusters of galaxies. Nearly seventy sq. arcmin were covered over the clusters A370, A2218 and A2390. We present maps and photometry at 6.7 & 14.3 microns, showing a total of 145 mid-IR sources and the associated source counts. The 15 micron counts reach the faintest level yet recorded. All sources have counterparts in the optical or near-IR. Models of the clusters were used to correct for the effects of lensing, which increases the sensitivity of the survey. Seven of fifteen SCUBA sources were detected at 15 microns. Five have redshift between 0.23 & 2.8, with a median of 0.9. The field sources were counted to a lensing-corrected sensitivity of 30 microJy at 15 microns, and 14 microJy at 7 microns. The counts, corrected for completeness, contamination by cluster sources and lensing, confirm and extend findings of an excess by a factor of ten in the 15 micron population with respect to source models with no evolution. Source redshifts are mostly between 0.4 and 1.5. For the counts at 7 microns, integrating from 14 microJy to 460 microJy, we resolve 0.49+/-0.2 nW.m^(-2).sr^(-1) of the infrared background light (IBL) into discrete sources. At 15 microns we include the counts from other ISOCAM surveys to integrate from 30 microJy to 50 mJy, two to three times deeper than unlensed surveys, to resolve 2.7+/-0.62 nW.m^(-2).sr^(-1) of the IBL. These values are 10% and 55%, respectively, of the upper limit to the IBL, derived from photon-photon pair production of the TeV gamma rays from BL-Lac sources on the IBL photons. However, recent detections of TeV gamma rays from the z=0.129 BL Lac H1426+428 suggest that the 15 micron background reported implies substantial absorption of TeV photons from that source.Comment: 35 pages, 17 figures, to appear in Astronomy and Astrophysics, full paper with high-resolution figures available at http://www.iso.vilspa.esa.es/science/pub/2003

Investigation into the effects of salt chemistry and SO2 on the crack initiation of CMSX-4 in static loading conditions

Although evidence exists of the potential impact of stress, co-incident with corrosive environments at high temperature, for single crystal turbine blades, the mechanism responsible is not fully understood. This work explores the effect of CaSO4, Na2SO4 and sea salt on the scale formation and crack initiation of CMSX-4 at 550°C in 50 ppm of SO2 and synthetic air under a static stress of 800 MPa. The cross-sectional analysis showed that the CaSO4 and the Na2SO4 salted specimens did not undergo a significant degree of corrosion degradation and no cracks were detected after 400 hours of exposure. However, sea salt caused significant degradation to the scale and cracks were detected by X-ray CT scanning after 400 hours of exposure. The findings from this study suggests that the sulfation of chlorine containing species in sea salt led to the formation, vaporisation and re-oxidation of metal chlorides and this mechanism was found to play a key role in the formation of a non-protective scale. An active oxidation mechanism has been proposed to interpret the results. In conclusion, it is hypothesized that due to the synergistic effect of stress and the formation of a non-protective scale, fast diffusion paths for sulfur, oxygen and chlorine ingress were formed. Further work is currently being undertaken to understand the effect of these species on the local embrittlement of CMSX-4 that ultimately led to the initiation of cracks in the specimen

Martini 3 : a general purpose force field for coarse-grained molecular dynamics

The coarse-grained Martini force field is widely used in biomolecular simulations. Here we present the refined model, Martini 3 (http://cgmartini.nl), with an improved interaction balance, new bead types and expanded ability to include specific interactions representing, for example, hydrogen bonding and electronic polarizability. The updated model allows more accurate predictions of molecular packing and interactions in general, which is exemplified with a vast and diverse set of applications, ranging from oil/water partitioning and miscibility data to complex molecular systems, involving protein-protein and protein-lipid interactions and material science applications as ionic liquids and aedamers.Peer reviewe