Radial dose function of a 90Sr 90Y seed in water and A150: Comment on Calibration and characterization of beta-particle sources for intravascular brachytherapy

Intravascular brachytherapy with beta sources has become a useful technique to prevent restenosis after cardiovascular intervention. In particular, the Beta-Cath high-dose-rate system, manufactured by Novoste Corporation, is a commercially available 90Sr 90Y source for intravascular brachytherapy that is achieving widespread use. Its dosimetric characterization has attracted considerable attention in recent years. Unfortunately, the short ranges of the emitted beta particles and the associated large dose gradients make experimental measurements particularly difficult. This circumstance has motivated the appearance of a number of papers addressing the characterization of this source by means of Monte Carlo simulation techniques.

Comprehensive Genomic Characterization of Long Non-coding RNAs across Human Cancers.

The discovery of long non-coding RNA (lncRNA) has dramatically altered our understanding of cancer. Here, we describe a comprehensive analysis of lncRNA alterations at transcriptional, genomic, and epigenetic levels in 5,037 human tumor specimens across 13 cancer types from The Cancer Genome Atlas. Our results suggest that the expression and dysregulation of lncRNAs are highly cancer type specific compared with protein-coding genes. Using the integrative data generated by this analysis, we present a clinically guided small interfering RNA screening strategy and a co-expression analysis approach to identify cancer driver lncRNAs and predict their functions. This provides a resource for investigating lncRNAs in cancer and lays the groundwork for the development of new diagnostics and treatments.

Standardisation of elemental analytical techniques applied to provenance studies of archaeological ceramics: an inter laboratory calibration study

Chemical analysis is a well-established procedure for the provenancing of archaeological ceramics. Various analytical techniques are routinely used and large amounts of data have been accumulated so far in data banks. However, in order to exchange results obtained by different laboratories, the respective analytical procedures need to be tested in terms of their inter-comparability. In this study, the schemes of analysis used in four laboratories that are involved in archaeological pottery studies on a routine basis were compared. The techniques investigated were neutron activation analysis (NAA), X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). For this comparison series of measurements on different geological standard reference materials (SRM) were carried out and the results were statistically evaluated. An attempt was also made towards the establishment of calibration factors between pairs of analytical setups in order to smooth the systematic differences among the results.

Electronic properties of a quantum wire with arbitrary bending angle

The electron transmission and bound state properties of a quantum wire with a sharp bend at arbitrary angle are studied, extending results on the right angle sharp bend (the L¿shaped wire). These new results are compared to those of a similar structure, the circular bend wire. The possibility of using a bent wire to perform transistor action is also discussed.

L'arqueologia del vi a l'àrea costanera de la Tarraconense. Una reflexió

Com a valoració del simposi, es fa una discussió de les aportacions, dins dels coneixements actuals sobre la producció de vi, centrat a la costa de la Tarraconense. La cultura del vi a l’antiguitat és un tema en què les connexions amb l’actualitat sovint són més àmplies del que pensem. Es repassen totes les fonts romanes referents al vi dels Països Catalans. L’arqueologia de la vinya ha d’aprendre encara molt de la francesa. Els estudis dels trulls de vi van ampliant el coneixement dels llocs de producció, dels períodes –fins al tardoromà– i dels detalls tècnics. Les àmfores permeten conèixer la comercialització del producte, així com les cronologies i l’abast del negoci del vi, que devien endegar immigrants romans o itàlics que invertien en terres fora d’Itàlia. L’estudi dels ports acaba de completar el panorama comercial.

Sinfonia VI

Soitinnus: orkesteri. Melartinin käsikirjoitusluettelon tunnus Mel 3:11 (ks. http://lib.siba.fi/fi/kokoelmat/kasikirjoitusarkisto/melartin_erkki/).

Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H p (3) monitoring. A 2015 review.

A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 papers have been analysed and classified in the following topics: challenges of today in eye lens monitoring; conversion coefficients, phantoms and calibration procedures for eye lens dose evaluation; correction factors and dosemeters for eye lens dose measurements; dosemeter position and influence of protective devices. The major findings of the review can be summarised as follows: the recommended operational quantity for the eye lens monitoring is H p (3). At present, several dosemeters are available for eye lens monitoring and calibration procedures are being developed. However, in practice, very often, alternative methods are used to assess the dose to the eye lens. A summary of correction factors found in the literature for the assessment of the eye lens dose is provided. These factors can give an estimation of the eye lens dose when alternative methods, such as the use of a whole body dosemeter, are used. A wide range of values is found, thus indicating the large uncertainty associated with these simplified methods. Reduction factors from most common protective devices obtained experimentally and using Monte Carlo calculations are presented. The paper concludes that the use of a dosemeter placed at collar level outside the lead apron can provide a useful first estimate of the eye lens exposure. However, for workplaces with estimated annual equivalent dose to the eye lens close to the dose limit, specific eye lens monitoring should be performed. Finally, training of the involved medical staff on the risks of ionising radiation for the eye lens and on the correct use of protective systems is strongly recommended.

Development of a systematic computer vision-based method to analyse and compare images of false identity documents for forensic intelligence purposes-Part I: acquisition, calibration and validation issues

Following their detection and seizure by police and border guard authorities, false identity and travel documents are usually scanned, producing digital images. This research investigates the potential of these images to classify false identity documents, highlight links between documents produced by a same modus operandi or same source, and thus support forensic intelligence efforts. Inspired by previous research work about digital images of Ecstasy tablets, a systematic and complete method has been developed to acquire, collect, process and compare images of false identity documents. This first part of the article highlights the critical steps of the method and the development of a prototype that processes regions of interest extracted from images. Acquisition conditions have been fine-tuned in order to optimise reproducibility and comparability of images. Different filters and comparison metrics have been evaluated and the performance of the method has been assessed using two calibration and validation sets of documents, made up of 101 Italian driving licenses and 96 Portuguese passports seized in Switzerland, among which some were known to come from common sources. Results indicate that the use of Hue and Edge filters or their combination to extract profiles from images, and then the comparison of profiles with a Canberra distance-based metric provides the most accurate classification of documents. The method appears also to be quick, efficient and inexpensive. It can be easily operated from remote locations and shared amongst different organisations, which makes it very convenient for future operational applications. The method could serve as a first fast triage method that may help target more resource-intensive profiling methods (based on a visual, physical or chemical examination of documents for instance). Its contribution to forensic intelligence and its application to several sets of false identity documents seized by police and border guards will be developed in a forthcoming article (part II).

A feed-forward spiking model of shape-coding by IT cells

The ability to recognize a shape is linked to figure-ground (FG) organization. Cell preferences appear to be correlated across contrast-polarity reversals and mirror reversals of polygon displays, but not so much across FG reversals. Here we present a network structure which explains both shape-coding by simulated IT cells and suppression of responses to FG reversed stimuli. In our model FG segregation is achieved before shape discrimination, which is itself evidenced by the difference in spiking onsets of a pair of output cells. The studied example also includes feature extraction and illustrates a classification of binary images depending on the dominance of vertical or horizontal borders.

Autoevaluación del aprendizaje en enfermería con ejercicios interactivos del programa Hot Potatoes

Los ejercicios interactivos de autoevaluación son una herramienta muy útil para fomentar el aprendizaje autónomo del estudiante. El programa Hot Potatoes permite el diseño de actividades interactivas para la evaluación formativa, con la incorporación de un sistema de retroacción que refuerza los contenidos no asimilados cuando la respuesta no es correcta. El objetivo de estudio es averiguar la opinión de los estudiantes sobre la utilización del programa Hot Potatoes. Materiales y métodos: Estudio descriptivo transversal en la promoción 2006-2007 de la asignatura Enfermería Maternal II. Los datos se recogieron a través de un cuestionario diseñado ad hoc. Resultados: Los ejercicios mejor valorados y considerados de menor dificultad fueron los de opción múltiple; los más difíciles fueron los textos desordenados y los ejercicios de rellenar huecos. Todos los estudiantes consideraron que el método motivó su interés por la asignatura y facilitó su aprendizaje. El 71% considera que el método le ha servido para adquirir conocimientos y ha sido muy útil como herramienta de estudio. Los aspectos que consideran más interesantes incluyen que: son un método de repaso y estudio, facilitan el aprendizaje de una forma amena y permiten conocer el nivel de conocimientos y corregir los errores durante el aprendizaje. Entre los aspectos que mejorarían destacan que incluirían más ejercicios y un número de preguntas más elevado. Conclusiones: El método ha tenido una buena aceptación y ha fomentado el aprendizaje autónomo. Consideramos que se trata de una estrategia de autoevaluación adecuada para la adaptación a los nuevos créditos europeos (ECTS).

Multimodal stimulus coding by a gustatory sensory neuron in Drosophila larvae.

Accurate perception of taste information is crucial for animal survival. In adult Drosophila, gustatory receptor neurons (GRNs) perceive chemical stimuli of one specific gustatory modality associated with a stereotyped behavioural response, such as aversion or attraction. We show that GRNs of Drosophila larvae employ a surprisingly different mode of gustatory information coding. Using a novel method for calcium imaging in the larval gustatory system, we identify a multimodal GRN that responds to chemicals of different taste modalities with opposing valence, such as sweet sucrose and bitter denatonium, reliant on different sensory receptors. This multimodal neuron is essential for bitter compound avoidance, and its artificial activation is sufficient to mediate aversion. However, the neuron is also essential for the integration of taste blends. Our findings support a model for taste coding in larvae, in which distinct receptor proteins mediate different responses within the same, multimodal GRN.

Autoevaluación del aprendizaje en enfermería con ejercicios interactivos del programa Hot Potatoes

Los ejercicios interactivos de autoevaluación son una herramienta muy útil para fomentar el aprendizaje autónomo del estudiante. El programa Hot Potatoes permite el diseño de actividades interactivas para la evaluación formativa, con la incorporación de un sistema de retroacción que refuerza los contenidos no asimilados cuando la respuesta no es correcta. El objetivo de estudio es averiguar la opinión de los estudiantes sobre la utilización del programa Hot Potatoes. Materiales y métodos: Estudio descriptivo transversal en la promoción 2006-2007 de la asignatura Enfermería Maternal II. Los datos se recogieron a través de un cuestionario diseñado ad hoc. Resultados: Los ejercicios mejor valorados y considerados de menor dificultad fueron los de opción múltiple; los más difíciles fueron los textos desordenados y los ejercicios de rellenar huecos. Todos los estudiantes consideraron que el método motivó su interés por la asignatura y facilitó su aprendizaje. El 71% considera que el método le ha servido para adquirir conocimientos y ha sido muy útil como herramienta de estudio. Los aspectos que consideran más interesantes incluyen que: son un método de repaso y estudio, facilitan el aprendizaje de una forma amena y permiten conocer el nivel de conocimientos y corregir los errores durante el aprendizaje. Entre los aspectos que mejorarían destacan que incluirían más ejercicios y un número de preguntas más elevado. Conclusiones: El método ha tenido una buena aceptación y ha fomentado el aprendizaje autónomo. Consideramos que se trata de una estrategia de autoevaluación adecuada para la adaptación a los nuevos créditos europeos (ECTS).

Doses monitoring in radiology: calibration of air kerma-area product (PKA) meters

Objective The authors have sought to study the calibration of a clinical PKA meter (Diamentor E2) and a calibrator for clinical meters (PDC) in the Laboratory of Ionizing Radiation Metrology at Instituto de Energia e Ambiente - Universidade de São Paulo. Materials and Methods Different qualities of both incident and transmitted beams were utilized in conditions similar to a clinical setting, analyzing the influence from the reference dosimeter, from the distance between meters, from the filtration and from the average beam energy. Calibrations were performed directly against a standard 30 cm3 cylindrical chamber or a parallel-plate monitor chamber, and indirectly against the PDC meter. Results The lowest energy dependence was observed for transmitted beams. The cross calibration between the Diamentor E2 and the PDC meters, and the PDC presented the greatest propagation of uncertainties. Conclusion The calibration coefficient of the PDC meter showed to be more stable with voltage, while the Diamentor E2 calibration coefficient was more variable. On the other hand, the PDC meter presented greater uncertainty in readings (5.0%) than with the use of the monitor chamber (3.5%) as a reference.

Running mechanical alterations during repeated treadmill sprints in hot versus hypoxic environments : a pilot study.

We determined if performance and mechanical running alterations during repeated treadmill sprinting differ between severely hot and hypoxic environments. Six male recreational sportsmen (team- and racket-sport background) performed five 5-s sprints with 25-s recovery on an instrumented treadmill, allowing the continuous (step-by-step) measurement of running kinetics/kinematics and spring-mass characteristics. These were randomly conducted in control (CON; 25°C/45% RH, inspired fraction of oxygen = 20.9%), hot (HOT; 38°C/21% RH, inspired fraction of oxygen = 20.9%; end-exercise core temperature: ~38.6°C) and normobaric hypoxic (HYP, 25°C/45% RH, inspired fraction of oxygen = 13.3%/simulated altitude of ~3600 m; end-exercise pulse oxygen saturation: ~84%) environments. Running distance was lower (P < 0.05) in HOT compared to CON and HYP for the first sprint but larger (P < 0.05) sprint decrement score occurred in HYP versus HOT and CON. Compared to CON, the cumulated distance covered over the five sprints was lower (P < 0.01) in HYP but not in HOT. Irrespective of the environmental condition, significant changes occurred from the first to the fifth sprint repetitions (all three conditions compounded) in selected running kinetics (mean horizontal forces, P < 0.01) or kinematics (contact and swing times, both P < 0.001; step frequency, P < 0.001) and spring-mass characteristics (vertical stiffness, P < 0.001; leg stiffness, P < 0.01). No significant interaction between sprint number and condition was found for any mechanical data. Preliminary evidence indicates that repeated-sprint ability is more impaired in hypoxia than in a hot environment, when compared to a control condition. However, as sprints are repeated, mechanical alterations appear not to be exacerbated in severe (heat, hypoxia) environmental conditions.