1,089 research outputs found

    A point mutation in the splice donor site of intron 7 in the as2-casein encoding gene of the Mediterranean River buffalo results in an allele-specific exon skipping

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    The CSN1S2 cDNA of 10 unrelated Mediterranean River Buffaloes reared in Southern Italy was amplified by RT-PCR, while the region from the 6th to the 8th exon of the CSN1S2 gene was amplified from genomic template. cDNA sequence comparisons showed that five individuals had a normal transcript only (named CSN1S2A), one had a deleted transcript only (named CSN1S2B), because of the splicing out of the 27-bp of exon 7, and the remaining four had a heterozygous pattern. Analysis of the genomic sequences revealed a FM865620: g.773G>C transversion that caused inactivation of the intron 7 splice donor site and, consequently, the allele-specific exon skipping characteristic of the CSN1S2B allele. The g.773G>C mutation creates a new AluI restriction site enabling a PCR– RFLP rapid genotyping assay. The cDNA sequences showed three additional exonic mutations forming an extended haplotype with the g.773G>C polymorphism: FM865618: c.459C>T, c.484A>T and c.568A>G homozygous and heterozygous respectively in the CSN1S2BB and CSN1S2AB buffaloes. The first is silent, while the remaining two are non-conservative (p.Ile162Phe and p.Thp200Ala respectively). The genotype frequencies (37 CSN1S2A/A, 15 CSN1S2A/B and one CSN1S2B/B) are in agreement with Hardy–Weinberg equilibrium, with the frequency of the deleted B allele being 0.16. The predicted bubaline as2B protein is 198 aa long instead of 207 aa and would also be characterized by the presence of Phe at position 147 and Ala at 185

    Waiting times in emergency departments: A resource allocation or an efficiency issue?

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    Background: In recent years, the flow of patients to the Emergency Departments (ED) of Western countries has steadily increased, thus generating overcrowding and extended waiting times. Scholars have identified four main causes for this phenomenon, related to: continuity of primary care services; availability of specific clinical pathways for chronic patients; ED's personnel endowment; organization of the ED. This study aims at providing a logical diagnostic framework to support managers in investigating specific solutions to be applied to their EDs to cope with high ED waiting times. The framework is based on the ED waiting times and ED admission rate matrix. It was applied to the Tuscan EDs as illustrative example. Methods: To provide the factors to be analyzed once the EDs are positioned into the matrix, a list of issues has been identified. The matrix was applied to Tuscan EDs. Data were collected from the Tuscan performance evaluation system, integrated with specific data on Tuscan EDs' personnel. The Tuscan EDs matrix, the descriptive statistics for each quadrant and the Spearman's rank correlation analysis among waiting times, admission rates and a set of performance indicators were conducted to help managers to read the phenomena that they need to investigate. Results: The combined reading of the correlations and waiting times-admission rates matrix shows that there are no optimal rules for all the EDs in managing admission rates and waiting times, but solutions have to be found considering mixed and personalized strategies. Conclusions: The waiting times-admission rates matrix provides a tool able to support managers in detecting the problems related to the management of ED services. In particular, using this matrix, healthcare managers could be facilitated in the identification of possible solutions for their specific situation

    The influence of commercially-available carbohydrate and carbohydrate-protein supplements on endurance running performance in recreational athletes during a field trial

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    Background It is recommended that endurance athletes consume carbohydrate (CHO) supplements, providing 6-8% CHO concentration, during exercise \u3e 60 minutes to improve athletic performance. Recently research has compared carbohydrate-protein (CHO-P) supplementation to the traditionally used CHO supplementation during endurance exercise, following these supplementation recommendations, in controlled settings, but not under simulated applied conditions such as a field trial. Therefore, the purpose of the present investigation was to test CHO and CHO-P supplementation under applied conditions such that commercially-available isocaloric (CHO-P & double-carbohydrate [CHO-CHO]) and isocarbohydrate (CHO-P & CHO) supplements were compared to a placebo (PLA), within an outdoor running field trial \u3e 60 minutes in order to asses their influence on endurance performance. Methods Twelve male recreational runners completed four, 19.2 km runs, where they were instructed to run at a pace similar to race pace including a final sprint to the finish, which in this case was the final two laps of the course (1.92 km). Supplementation was provided before the start and in 4 km increments. Performance was measured by time to complete the 19.2 km run and last 1.92 km sprint. Results Analyses found no difference between supplements in time to complete the 19.2 km run (PLA = 88.6 ± 11.6 min, CHO = 89.1 ± 11.3 min, CHO-P = 89.1 ± 11.8 min, CHO-CHO = 89.6 ± 11.9 min) or last 1.92 km sprint to the finish (PLA = 8.3 ± 1.2 min, CHO = 8.2 ± 1.2 min, CHO-P = 8.2 ± 1.2 min, CHO-CHO = 8.4 ± 1.5 min). Conclusions When following recommendation for supplementation within a field trial, commercially available CHO and CHO-P supplements do not appear to enhance performance in male recreational runners

    Crack of a helicopter main rotor actuator attachment: failure analysis and lessons learned

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    A Light Utility Helicopter (LUH), in the course of a training flight, leaving the ground during thetaxi to take off, went into an uncontrolled rolling to the right; consequently the helicopter gradually laid downon the right side. The impact with the runway destroyed the rotating blades up to the hubs rotor. The accidentinvestigation focused on main rotor oscillatory plate servo actuators . These components, directly linked to thecloche movements, regulate main rotor blades plane tilt and pitch. Following the preliminary examination, onlyfront servo actuator attachment was found to be broken in two parts. In detail, the present paper deals with thefracture analysis results. The servo actuator attachment material is a 2014 Aluminum alloy extrudate, undergoneto T651 heat treatment. Fracture surfaces were examined by optical and electronic microscopy in order todetermine the main morphological features and consequently to trace the origin of failure mechanism andcauses. The accordance with the specification requirements about alloy composition was verified by quantitativeelementary analysis through inductive coupled plasma spectroscopy (ICP); furthermore, semi-quantitativeelementary analysis was locally verified by Energy dispersion spectroscopy X ray (EDS_RX). Finally, thehydrogen content of the material was evaluated by the total hydrogen analysis. Microstructural andtechnological alloy characteristics were verified as well by using metallographic microscopy and hardness testingof the material.Macroscopic fracture surfaces evidences were characterized by the lack of any significant plastic deformationsand by the presence of symmetry compared to the servo actuator axis. Microscopic fracture features of both theinvestigated surfaces were not coherent to the hypothesis of an impact of the main rotor to the soil. Furtherachieved evidences, such as grain boundary fracture propagation, the presence of corrosion products, were all inaccordance with a Stress Corrosion Cracking (SCC) progressive fracture mechanism.Finite Element Analysis (FEA) located the highest tensile stress value, when the servo actuator is in its nominalworking condition, at the same points where the corrosion products were more concentrated (i.e. in the part ofthe fracture exposed to oxidative air effect for the longest time). The good agreement between FEA andmorphological evidences allowed to determine the progressive fracture origin area, though it was not possible toindividuate the crack initiation point. In fact, in correspondence to the initiation area of both the fracturesurfaces, shining and flat morphology was found;. then there were evidence of plastic deformations, due to thedetachment of a servo actuator part.The ICP analysis and hardness testing results were in accordance with the material specification requirements.However, the hydrogen content was one order of magnitude greater than the required value and many andunexpected globular formations were observed on the fracture surface. Part of these were dendritic formations,while the others looked smooth and shining. Further, FESEM boundary grain observation gave evidences of ahigh presence of precipitates on the investigated surfaces. Hence, observed microstructural characteristics,boundary grain precipitates and globular formations allowed to hypothesize possible overheating/eutecticmelting phenomena, occurred during manufacturing processes.As widely reported in literature, the AA 2014 alloy is one of the aluminum-copper-magnesium-silicon type,employing copper aluminide (CuAl2 ) as the primary precipitation-hardening agent. The need for a maximumCu phase dispersion in solid solution requires a heat treatment range with an upper limit (507°C) that is near tothe melting of the eutectics (510°C). Moreover, since the 1960s, AA2014 has been defined as sensitive to SCC.This condition is mainly related to the presence of coarse-grained and aligned CuAl2 precipitates. Thisarrangement is due to an overheating (more than 507°C) or to a cooling process carried out too slowly.Microstructural analysis was carried out on three items: 1) a large portion of the broken actuator attachment; 2)on a servoactuator coming from the same production batch; 3) on a servo actuator coming from a differentproduction batch.The microstructure from the broken actuator attachment showed a great amount of precipitates (secondphases) lengthwise aligned to the boundary grain, pores, and also cavities and dendritic globular formations.Analysis results, morphology evidences and reference images available on scientific literature were found to bein excellent agreement and validated the embrittlement and subsequent SCC mechanism hypotesis(intergranular failure propagation).In conclusion, flight accident causes are attributable to main rotor actuator attachment failure.Failure mechanism is classifiable as SCC supported by microstructural anomalies of the material. Theinvestigation of the manufacturing process highlighted how one of the servo actuator batches was not properlyproduced due to poor control and accuracy of heat treatment temperature and/or cooling time. This led tohydrogen embrittlement and to a microstructural problem (globular formations and boundary grainprecipitates). The combination of those phenomena caused an increase of the SCC sensitivity and were thebasic progressive failure driving forces.Nevertheless, as above mentioned, alloy composition was found compliant with the material specificationrequirements and this just because none of the scheduled quality control tests is able to determine the peculiarmicrostructural anomalies reported

    Plasticised regenerated silk/gold nanorods hybrids as sealant and bio-piezoelectric materials

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    Manual and mechanical suturing are currently the gold standard for bowel anastomosis. If tissue approximation fails, anastomotic leaks occur. Anastomotic leaks may have catastrophic consequences. The development of a fully absorbable, biocompatible sealant material based on a bio-ink silk fibroin can reduce the chance of anastomotic leaks. We have produced a Ca-modified plasticised regenerated silk (RS) with gold nanorods sealant. This sealant was applied to anastomosed porcine intestine. Water absorption from wet tissue substrate applied compressive strains on hybrid RS films. This compression results in a sealant effect on anastomosis. The increased toughness of the hybrid plasticised RS resulted in the designing of a bio-film with superior elongation at break (i.e., ≈200%) and bursting pressure. We have also reported structure-dependent piezoelectricity of the RS film that shows a piezoelectric effect out of the plane. We hope that in the future, bowel anastomosis can be simplified by providing a multifunctional bio-film that makes feasible the mechanical tissue joint without the need for specific tools and could be used in piezoelectric sealant heads

    Functional connectivity modules in recurrent neural networks: function, origin and dynamics

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    Understanding the ubiquitous phenomenon of neural synchronization across species and organizational levels is crucial for decoding brain function. Despite its prevalence, the specific functional role, origin, and dynamical implication of modular structures in correlation-based networks remains ambiguous. Using recurrent neural networks trained on systems neuroscience tasks, this study investigates these important characteristics of modularity in correlation networks. We demonstrate that modules are functionally coherent units that contribute to specialized information processing. We show that modules form spontaneously from asymmetries in the sign and weight of projections from the input layer to the recurrent layer. Moreover, we show that modules define connections with similar roles in governing system behavior and dynamics. Collectively, our findings clarify the function, formation, and operational significance of functional connectivity modules, offering insights into cortical function and laying the groundwork for further studies on brain function, development, and dynamics

    In-Operation Experimental Modal Analysis of a Three Span Open-Spandrel RC Arch Bridge

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    This paper presents the results of the dynamic tests conducted on a historical reinforced concrete arch bridge located in the Tuscan-Emilian Apennines, in the province of Parma (Italy). The design of the sensors location was determined in order to investigate the possible separation into bodies operated by the joints between the different spans. The ambient vibration data allowed the dynamic characterization of the 3-span arch bridge with the total length of 146 m and 18 m in width. The interpretation of the main global modes, distinctly detected through time domain identification methods, indicates that the horizontal response is governed by the deformability of the joints. The results show that the obtained modal features provide a reliable reference for the subsequent updating of the bridge FE model
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