Positron trapping and annihilation at interfaces between matrix and cylindrical or spherical precipitates modeled by diffusion-reaction theory

The exact solution of a diffusion$-$reaction model for the trapping and annihilation of positrons at interfaces of precipitate$-$matrix composites is presented considering both cylindrical or spherical precipitates. Diffusion-limitation is taken into account for interfacial trapping from the surrounding matrix as well as from the interior of the precipitate. Closed-form expressions are obtained for the mean positron lifetime and for the intensity of the positron lifetime component associated with the interface-trapped state. The model contains as special case also positron trapping at extended open-volume defects like spherical voids or hollow cylinders. This makes the model applicable to all types of cylindrical- and spherical-shaped extended defects irrespective of their size and their number density.Comment: To be published in the Proceedings of International Conference on Positrron Annihilation, 2018; submitted August 16, 2018; Accepted January 8, 2019. AIP Conference Proceeding

Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). This glue has several disadvantages, which motivated the search for an alternative. This paper presents a study concerning the use of six ultra-violet (UV) cure glues and a glue pad for use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, the thermal conduction and shear strength, thermal cycling, radiation hardness, corrosion resistance and shear strength tests. These investigations led to the exclusion of three UV cure glues as well as the glue pad. Three UV cure glues were found to be possible better alternatives. Results from electrical tests of first prototype modules constructed using these glues are presented.Comment: 23 pages, to be published in Journal of Instrumentatio

Magnetnoresonančno slikanje srca pri bolnikih s presajenim srcem

Omejujoči dejavnik kratkoročnega preživetja pri bolnikih po presaditvi srca je zavrnitev presadka, dolgoročno preživetje pa omejuje predvsem vaskulopatija presadka. Za bolnike po presaditvi srca je ključnega pomena, da morebitno zavrnitveno reakcijo ali pa vaskulopatijo presadka odkrijemo v zgodnji fazi bolezni, ko so terapevtski ukrepi še učinkoviti in presadek še ni nepovratno poškodovan. Danes je prva izbira pri diagnosticiranju vaskulopatije koronarografija, zlati standard pri diagnosticiranju zavrnitvene reakcije pa je endomiokardna biopsija. Zaradi invazivnosti, potrebe po hospitalni obravnavi in suboptimalni občutljivosti obeh preiskav se vse več raziskav usmerja v neinvazivne diagnostične pristope, med katerimi se je kot obetajoča preiskava izkazalo zlasti magnetnoresonančno slikanje srca. V preglednem članku bomo predstavili uporabnost magnetnoresonančnega slikanja srca pri bolnikih s presajenim srcem, njegove prednosti in izhodišča za razvoj pri zgodnjem diagnosticiranju zavrnitvenih reakcij in vaskulopatije presadka v prihodnosti

Journeys to identity : why care records matter

Care experienced people often find themselves applying for their care records in search of answers — to address gaps and inconsistencies in the knowledge they hold about their childhoods and personal development, which may in turn affect their broader senses of self. This article, written from our own lived experiences, provides a commentary on a system of writing, accessing and reading records which is not aligned to the circumstances and purposes of care experienced people and which indeed frequently disempowers and (re-)traumatises. We share our experiences of applying for and reading our records, as an adoptee and as a care experienced person. We also draw on the discussions and experiences of a Who Cares? Scotland care records campaign group. This commentary reveals the power imbalance at the heart of record keeping where the rights to memory, identity, and childhood are effectively questioned. It also makes suggestions for future practice. It asks for a complete rethinking of how care records are regarded by professionals and the sector, advocating for a shift in power as regards the production and control of information and a significant improvement in the care offered to those of us who choose to access it

More Than Just Adolescence: Differences in Fatigue Between Youth With Cerebral Palsy and Typically Developing Peers

Objective To quantify differences in fatigue and disordered sleep between adolescents with cerebral palsy (CP) and their typically developing peers. A secondary aim was to investigate the association between fatigue and disordered sleep in adolescents with CP. Methods A convenience sample of 36 youth with CP aged 10-18 years was matched for age and sex with 36 typically developing peers. The Fatigue Impact and Severity Self-Assessment (FISSA), the Patient-Reported Outcome Measurement Information System (PROMIS) fatigue profile, and the Sleep Disturbance Scale for Children (SDSC) were collected. Results Higher fatigue was reported in participants with CP than in their typically developing peers based on the FISSA total score (mean paired difference=19.06; 99% confidence interval [CI], 6.06-32.1), the FISSA impact subscale (mean paired difference=11.19; 99% CI, 3.96-18.4), and the FISSA Management and Activity Modification subscale (mean paired difference=7.86; 99% CI, 1.1-14.6). There were no differences between groups in the PROMIS fatigue profile (mean paired difference=1.63; 99% CI, -1.57-4.83) or the SDSC total score (mean paired difference=2.71; 99% CI, -2.93-8.35). Conclusion Youth with CP experienced significantly more fatigue than their peers as assessed by a comprehensive measure that considered both general and diagnosis-specific concerns. Sleep did not differ between youth with CP and their typically developing peers. These findings underscore the need to consider the clinical management of fatigue across the lifespan of individuals with CP to prevent the associated deterioration of functional abilities

Temperature-Dependence of Weibel-Palade Body Exocytosis and Cell Surface Dispersal of von Willebrand Factor and Its Propolypeptide

Background: Weibel-Palade bodies (WPB) are endothelial cell (EC) specific secretory organelles containing Von Willebrand factor (VWF). The temperature-dependence of Ca2+-driven WPB exocytosis is not known, although indirect evidence suggests that WPB exocytosis may occur at very low temperatures. Here we quantitatively analyse the temperature-dependence of Ca2+-driven WPB exocytosis and release of secreted VWF from the cell surface of ECs using fluorescence microscopy of cultured human ECs containing fluorescent WPBs. Principal Findings: Ca2+-driven WPB exocytosis occurred at all temperatures studied (7–37°C). The kinetics and extent of WPB exocytosis were strongly temperature-dependent: Delays in exocytosis increased from 0.92 s at 37°C to 134.2 s at 7°C, the maximum rate of WPB fusion decreased from 10.0±2.2 s−1 (37°C) to 0.80±0.14 s−1 (7°C) and the fractional extent of degranulation of WPBs in each cell from 67±3% (37°C) to 3.6±1.3% (7°C). A discrepancy was found between the reduction in Ca2+-driven VWF secretion and WPB exocytosis at reduced temperature; at 17°C VWF secretion was reduced by 95% but WPB exocytosis by 75–80%. This discrepancy arises because VWF dispersal from sites of WPB exocytosis is largely prevented at low temperature. In contrast VWF-propolypeptide (proregion) dispersal from WPBs, although slowed, was complete within 60–120 s. Novel antibodies to the cleaved and processed proregion were characterised and used to show that secreted proregion more accurately reports the secretion of WPBs at sub-physiological temperatures than assay of VWF itself. Conclusions : We report the first quantitative analysis of the temperature-dependence of WPB exocytosis. We provide evidence; by comparison of biochemical data for VWF or proregion secretion with direct analysis of WPB exocytosis at reduced temperature, that proregion is a more reliable marker for WPB exocytosis at reduced temperature, where VWF-EC adhesion is increased

Definition and Application of a Computational Parameter for the Quantitative Production of Hydroponic Tomatoes Based on Artificial Neural Networks and Digital Image Processing.

This work presents an alternative method, referred to as Productivity Index or PI, to quan tify the production of hydroponic tomatoes using computer vision and neural networks, in contrast to other well-known metrics, such as weight and count. This new method also allows the automation of processes, such as tracking of tomato growth and quality control. To compute the PI, a series of computational processes are conducted to calculate the total pixel area of the displayed tomatoes and obtain a quantitative indicator of hydroponic crop production. Using the PI, it was possible to identify objects belonging to hydroponic tomatoes with an error rate of 1.07%. After the neural networks were trained, the PI was applied to a full crop season of hydroponic tomatoes to show the potential of the PI to monitor the growth and maturation of tomatoes using different dosages of nutrients. With the help of the PI, it was observed that a nutrient dosage diluted with 50% water shows no difference in yield when compared with the use of the same nutrient with no dilution.CONACYT - Consejo Nacional de Ciencia y TecnologíaPROCIENCI