Preguntas de opción múltiple versus preguntas de respuesta muy breve en la evaluación de estudiantes de patología veterinaria

Background: Well-developed assessment methods have a positive impact on students’ performance, and higher education institutes are usually encouraged to establish and use effective assessment methods that effectively enhance the learning process. Objectives: This study was designed to compare students’ performance in multiple choice questions (MCQs) including best single answer (BSA) and multiple true and false (MTF) types, and very short answer (VSA) questions, and to evaluate gender differences and feedback from students and faculty. Materials and methods: A test containing three different types of questions, BSA, MTF and VSA questions (10 each), was delivered to eight groups of veterinary pathology students (3rd level, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt) in April 2022. Students’ performance, test reliability and gender differences as well as feedback from students and faculty were evaluated. Results: Students did a significant higher performance in BSA and MTF questions compared to VSA questions. The reliability of BSA, MTF and VSA questions between different groups of students were 0.53, 0.52 and 0.13, respectively. Girl students achieved a higher performance in the whole test compared to boy students. Both boy and girl students showed nearly similar performance in BSA and MTF questions. However, girl students got significant higher score in VSA questions compared to boy students. Students’ and faculty opinions were in favor of BSA and MTF questions. Conclusion: Students did much better in MCQs than VSA questions. BSA and MTF questions are preferentially favored by students and faculty. &nbsp

THE USE OF TUNED FRONT END OPTICAL RECEIVER AND PULSE POSITION MODULATION

The aim of this work is to investigate the use of tuned front-ends with OOK and PPM schemes, in addition to establish a theory for baseband tuned front end receivers. In this thesis, a background of baseband receivers, tuned receivers, and modulation schemes used in baseband optical communication is presented. Also, the noise theory of baseband receivers is reviewed which establishes a grounding for developing the theory relating to optical baseband tuned receivers. This work presents novel analytical expressions for tuned transimpedance, tuned components, noise integrals and equivalent input and output noise densities of two tuned front-end receivers employing bi-polar junction transistors and field effect transistors as the input. It also presents novel expressions for optimising the collector current for tuned receivers. The noise modelling developed in this work overcomes some limitations of the conventional noise modelling and allows tuned receivers to be optimised and analysed. This work also provides an in-depth investigation of optical baseband tuned receivers for on-off keying (OOK), Pulse position modulation (PPM), and Di-code pulse position modulation (Di-code PPM). This investigation aims to give quantitative predictions of the receiver performance for various types of receivers with different photodetectors (PIN photodetector and avalanche photodetector), different input transistors (bi-polar junction transistor BJT and field effect transistor FET), different pre-detection filters (1st order low pass filter and 3rd order Butterworth filter), different detection methods, and different tuned configurations (inductive shunt feedback front end tuned A and serial tuned front end tuned B). This investigation considers various optical links such as line of sight (LOS) optical link, non-line of sight (NLOS) link and optical fibre link. All simulations, modelling, and calculations (including: channel modelling, receiver modelling, noise modelling, pulse shape and inter-symbol interference simulations, and error probability and receiver calculations) are performed by using a computer program (PTC Mathcad prime 4, version: M010/2017) which is used to evaluate and analyse the performance of these optical links. As an outcome of this investigation, noise power in tuned receivers is significantly reduced for all examined configurations and under different conditions compared to non-tuned receivers. The overall receiver performance is improved by over 3dB in some cases. This investigation provides an overview and demonstration of cases where tuned receiver can be optimised for baseband transmission, offering a much better performance compared to non-tuned receivers. The performance improvement that tuned receivers offers can benefit a wide range of optical applications. This investigation also addresses some recommendations and suggestions for further work in some emerging applications such as underwater optical wireless communication (UOWC), visible light communication (VLC), and implantable medical devices (IMD). Keyword: Optical communications, Baseband receivers, Noise modelling, tuned front end, pulse position modulation (PPM)

Detection of Vapour Emissions from Star Anise Seeds and Mint Leaves using the CO2 Laser Photoacoustic Technique

The aim of this work was to establish the feasibility of the detection of the vapours of the star anise and mint essential oils emitted from the uncrushed seeds of star anise (Illicium verum H.) and from the leaves of Japanese mint (Mentha arvensis L.) respectively using a heat pipe type of photoacoustic cell in conjunction with a line tunable waveguide CO2 laser. Infrared photoacoustic stick spectra were obtained with excellent reproducibility and a high signal-to-noise ratio for the vapour emissions in one atmosphere of nitrogen gas over a temperature range from 20°C up to 180°C in the case of anise seeds and from 20°C to 100°C for mint leaves. Significant differences found between the photoacoustic spectra from the vapour emission of seeds and leaves when compared with commercial samples of the related essential oils are discussed.The financial support for travel from the British Council, East Jerusalem to (DL, MA-T) and that from Royal Society of London to (MA-T, KH) are gratefully acknowledged

Knowledge and Awareness about Aggravating Factors of the Peptic Ulcer Disease: A Cross-Sectional Study

Background: Peptic ulcer disease is a gastrointestinal disorder due to the imbalance between the defense mechanism and gastric acid secretion. It affects 5-10% of the population worldwide and induces eight million deaths every year globally. In Sudan, this disease represents one of the major health problems. Limited studies have shown the knowledge level of Sudanese about aggravating factors of Peptic ulcer disease, which lead to more prevalent complications. Therefore, this study aimed to assess awareness about aggravating factors of peptic ulcer disease among the population of Khartoum state, Sudan. Method: A descriptive cross-sectional study targeted the general population in Khartoum state during the period from January to June 2022. We used an online survey form to collect data from the study population. The distribution of the questionnaire was done via social media tools. We analyzed the data using SPSS Software version 26. Results: The study included 398 participants, 40.7% of them male and 59.3% female, with mean age equal to 24.9 (SD=8.9), and a range between (18-64). Most of the participants (77.1%) were unmarried and (89.2%) were educated. The type of food was the most known risk factor (79.1%) and the weather changes were the least known risk factor (8.5%) that have effects on peptic ulcers. There also was a significant difference between educated and non-educated people based on the awareness of peptic ulcer risk factors, as the second was higher (p>0.000). Furthermore, people with peptic ulcers and people who have one or more members of their family with peptic ulcers scored more than nonpatients and those who did not have (p>0.000, p= 0.04; respectively). Conclusion: In conclusion, awareness about aggravating factors of peptic ulcers was variable among the population in Khartoum state. Our study findings revealed a high knowledge effect of type of food, helicobacter pylori, analgesic medications, drinking coffee, smoking, and social stress of the majority population. As for other factors, weather changes, genetic factors, and body weight were associated with a poor level of awareness. Lastly, these results need to be affirmed by furthermore research with a large sample among the general population in different regions in Sudan

Analysis of the effect of renal excretory system cooling during thermal radiofrequency ablation in an animal model

Objective: Analysis of renal excretory system integrity and efficacy of radiofrequency ablation with and without irrigation with saline at 2 o C (SF2). Materials and Methods: The median third of sixteen kidneys were submitted to radiofrequency (exposition of 1 cm) controlled by intra-surgical ultrasound, with eight minutes cycles and median temperature of 90 o C in eight female pigs. One excretory renal system was cooled with SF2, at a 30ml/min rate, and the other kidney was not. After 14 days of post-operatory, the biggest diameters of the lesions and the radiological aspects of the excretory system were compared by bilateral ascending pyelogram and the animals were sacrificed in order to perform histological analysis. Results: There were no significant differences between the diameters of the kidney lesions whether or not exposed to cooling of the excretory system. Median diameter of the cooled kidneys and not cooled kidneys were respectively (in mm): anteroposterior: 11.46 vs. 12.5 (p = 0.23); longitudinal: 17.94 vs. 18.84 (p = 0.62); depth: 11.38 vs. 12.25 (p = 0.47). There was no lesion of the excretory system or signs of leakage of contrast media or hydronephrosis at ascending pyelogram. Conclusion: Cooling of excretory system during radiofrequency ablation does not significantly alter generated coagulation necrosis or affect the integrity of the excretory system in the studied model.Pontifical Catholic University of Campinas Faculty of MedicineRadium InstituteFederal University of São PauloUniversity of Campinas School of Medical SciencesUNIFESPSciEL

Regional flood frequency analysis based on peaks-over-threshold approach : a case study for South-Eastern Australia

Study region: Southeast Australia Study focus: Regional flood frequency analysis (RFFA) is a widely adopted statistical method to estimate design floods in ungauged catchments. Annual maximum flood (AMF) model is the most popular method in developing RFFA techniques. However, the AMF-based approaches are criticised for its limitations in the range of very frequent to frequent flood estimation. As an alternative, the peaks-over-threshold (POT) based approach has shown theoretical advantages in this flood range. POT based RFFA is currently underemployed internationally due to its complexity in modelling. This study develops POT-based RFFA techniques for south-eastern Australia using data from 151 catchments. A comparison is made between ordinary least squares (OLS) and weighted least squares (WLS) methods in developing POT-based RFFA techniques. New hydrological insights for the region: The OLS based method is found to perform better than the WLS. The median relative error values of the developed prediction equations range 31–38%. The new POT-based RFFA technique overcomes the limitations of the current Australian Rainfall and Runoff, which does not have any RFFA technique for very frequent floods. It is expected that these new POT-based RFFA technique will be used in practice in south-east Australia

Analysis Of The Effect Of Renal Excretory System Cooling During Thermal Radiofrequency Ablation In An Animal Model.

Analysis of renal excretory system integrity and efficacy of radiofrequency ablation with and without irrigation with saline at 2°C (SF2). The median third of sixteen kidneys were submitted to radiofrequency (exposition of 1 cm) controlled by intra-surgical ultrasound, with eight minutes cycles and median temperature of 90°C in eight female pigs. One excretory renal system was cooled with SF2, at a 30mL/min rate, and the other kidney was not. After 14 days of post-operatory, the biggest diameters of the lesions and the radiological aspects of the excretory system were compared by bilateral ascending pyelogram and the animals were sacrificed in order to perform histological analysis. There were no significant differences between the diameters of the kidney lesions whether or not exposed to cooling of the excretory system. Median diameter of the cooled kidneys and not cooled kidneys were respectively (in mm): anteroposterior: 11.46 vs. 12.5 (p = 0.23); longitudinal: 17.94 vs. 18.84 (p = 0.62); depth: 11.38 vs. 12.25 (p = 0.47). There was no lesion of the excretory system or signs of leakage of contrast media or hydronephrosis at ascending pyelogram. Cooling of excretory system during radiofrequency ablation does not sig¬nificantly alter generated coagulation necrosis or affect the integrity of the excretory system in the studied model.4093-

Optimum design of a spur gear using a two level optimization approach

In this paper, we present a two level optimization approach in order to enhance the design process of a one-stage speed reducer. The proposed design methodology is performed using genetic algorithms which are judiciously combined with the use of :i) analytical models (1stlevel) and ii) Finite Element Method (FEM)based models ( 2nd level), to evaluate design candidates. Indeed, the use of CAD-CAE tools to develop higher fidelity FEM models allows to re-evaluate the attained first level designs, while accounting for new design parameters and advanced aspects which have been ignored in the first level. In order to minimize the computational burden, a metamodel based optimization technique is adopted at this second level. To illustrate the efficiency of the proposed approach, a case study of a spur gear based reducer is presented where the design of experiments is built using Hypercube Latin Sampling and surrogate models are constructed using Radial Basic Functions

Peaks-over-threshold based regional flood frequency analysis using regularised linear models

Regional flood frequency analysis (RFFA) is widely used to estimate design floods in ungauged catchments. Most of the RFFA techniques are based on the annual maximum (AM) flood model; however, research has shown that the peaks-over-threshold (POT) model has greater flexibility than the AM model. There is a lack of studies on POT-based RFFA techniques. This paper presents the development of POT-based RFFA techniques, using regularised linear models (least absolute shrinkage and selection operator, ridge regression and elastic net regression). The results of these regularised linear models are compared with multiple linear regression. Data from 145 stream gauging stations of south-east Australia are used in this study. A leave-one-out cross-validation is adopted to compare these regression models. It has been found that the regularised linear models provide quite accurate flood quantile estimates, with a median relative error in the range of 37 to 47%, which outperform the AM-based RFFA techniques currently recommended in the Australian Rainfall and Runoff guideline. The developed RFFA technique can be used to estimate flood quantiles in ungauged catchments in the study region