Методологические подходы к изучению дисциплины "Основы медицинской статистики" студентами фармацевтического факультета

методика преподаванияпреподаваниеобразование медицинскоеОБУЧЕНИЕСТАТИСТИКА /обучвысшее образованиемедицинская статистик

Microvascular Arteriovenous Shunting is a Probable Pathogenetic Mechanism in Erythromelalgia

Erythromelalgia is a condition consisting of red, warm, and burning painful extremities. Symptoms are relieved by cold and aggravated by heat. A wide variety of etiologic conditions can cause erythromelalgia, but one common pathogenetic mechanism, microvascular arteriovenous shunting, has been hypothesized. The aim of this study was to test this hypothesis. Quantification of skin microvascular perfusion using laser Doppler perfusion imaging and skin temperature at rest and after central body heating was performed in 14 patients with erythromelalgia and 11 controls. Attacks of erythromelalgia were induced in eight patients after heat provocation. In the plantar region of the foot, the location of numerous anatomical arteriovenous shunts, these patients significantly increased the skin perfusion as compared with asymptomatic patients with erythromelalgia and controls. In the dorsal region with few arteriovenous shunts no significant differences between the groups were demonstrated. The results show a relation between clinical symptoms and increased perfusion in the region of numerous anatomical arteriovenous shunts, and support the hypothesis of increased thermoregulatory arteriovenous shunt flow during attacks in primary erythromelalgia

Design-build experiences and student-centered-learning in biomedical engineering curricula

ABSTRACT The field of biomedical engineering (BME) is progressing rapidly into new areas, demanding the BME students to develop multidisciplinary skills, knowledge and a possibility for life-long learning. Changing the educational arena from teacher-centered to studentcentered-learning is a challenge in the BME domain. CDIO (Conceive Design Implement Operate) design-build courses, starting at the freshman year, makes laboratory and research environment enhance student-centered-learning resulting in communicative skills and teamwork. BME specialization, student-centered-learning and design-build experiences are introduced as an integrative part during the third and fourth academic year. Student-centeredlearning is often recognized as a situation where the learning possibilities are relevant to the students and where the students themselves determine the short-term goals. The expert or authority teaching has to be replaced by mentorship and facilitators. This is recognized in design-build courses. BME cases without a known solution can be treated and solved through integrative thinking and problem identification. The cognitive tasks require the acquisition and synthesis of information. It prepares students to participate in research laboratories as undergraduates and it prepares them for time-constrained problem-solving in the real world. For research studies and developments in working life, skills including dynamic group processes and awareness of the affective domain are necessary. BME education has three years experience of design-build courses from the freshman to the last academic year. Directives for the projects are based on clinical settings or demands engaging students to solve real world problems. Interaction with real customers or experts in the field encourages, stimulate and enhance all parts of the CDIO framework. To get a prosperous and successful work throughout the project cycle the project teams as we believe should be built on heterogeneous skill, age and gender, the affective domain all harmonized using a team contract. Project groups have also been enrolled with exchange students creating international groups. Feedback of the group process is given throughout the design-build project but especially after completion. Theoretical parts supplement the project and the group both in-depth but also to focus and harmonize the group towards the designbuild project outcome. Experts working in the field validate and test the project. Assessment is conformant to a student-centered-learning process as an integrative part of the course. Development of assessment protocols and strategies as an integrative part of the learning process must be stimulated and emphasized

Flight to Quality: Does the interest rate affect investors' reallocation of capital? : A quantitative study regarding the transfer of capital from stocks to bonds in Sweden over the past 30 years and the impact of interest rate levels

Bakgrund: Kapital på börsen förflyttas fram och tillbaka mellan olika tillgångar, vilket ären naturlig del av diversifieringen i portföljer. När osäkerheten ökar i marknaden väljerinvesterare normalt att förflytta kapital från aktier till säkrare tillgångar som exempelvisobligationer, vilket beskrivs som Flight to Quality (FTQ). Däremot har räntorna efter denglobala finanskrisen 2008 varit historiskt låga och under vissa perioder negativa, vilket i sintur försvagar förflyttningen. Sverige har här utmärkt sig, genom att till skillnad från USA,fortsatt att sänka räntan och legat på låga nivåer under en väldigt lång tid. Därmed uppstårfunderingar kring hur förflyttningar av kapital har sett ut i Sverige de senaste 30 åren, samthur det senaste lågränteklimatet påverkar. Syfte: Syftet med studien är att undersöka förhållandet mellan avkastningen på noteradeobligationer och aktier i Sverige från 1993 till 2022. Studien ska även undersöka hur enlågräntemiljö påverkar förhållandet. Metod: OMXSPI samt BMSD10Y har använts för att beräkna avkastningen på aktierrespektive obligationer från databaserna Refinitiv Eikon samt Refinitiv Datastream. Urvaleti studien uppgick till 7271 respektive 1526 observationer. Genom en kvantitativ metod ochdeduktiv ansats har studien utgått från teorin gällande FTQ för att undersöka hurkorrelationen förändrats. Vidare har regressioner använts för att säkerställa påverkan pånivån av korrelationen samt hur ett lågränteklimat påverkar styrkan i FTQ. Slutsats: Studiens resultat påvisar att korrelationen mellan aktier och obligationer undertidsperioden har varit svagt negativ med fyra olika strukturella förändringar under perioden.Vidare visar studiens resultat att ett lågränteklimat under perioden har försvagat styrkan iFTQ:er som inträffat i Sverige mellan 1993 och 2022. Studien bidrar till litteraturen inomområdet korrelation mellan aktier och obligationers avkastningar, samt litteraturen kringlågränteklimats påverkan på finansiella marknader.Background: Capital on the stock exchange is moved back and forth between differentassets, which is a natural part of the diversification of portfolios. When uncertainty increasesin the market, investors normally choose to move capital from equities to safer assets such asbonds, which is described as Flight to Quality (FTQ). On the other hand, interest rates afterthe global financial crisis in 2008 have been historically low and in some cases negative,which in turn weakens the capital movement. Sweden has distinguished itself, in that unlikethe United States, it has continued to lower its interest rates and have kept them at low levelsfor a very long time. This raises concerns about how capital movements over the past 30 yearshave developed in Sweden, and how the recent low interest rate climate is affecting. Purpose: The purpose of the study is to investigate the relationship between returns onstocks and bonds in Sweden from 1993 to 2022. The study will also investigate how a lowyield environment effects the relationship. Method: OMXSPI and BMSD10Y have been used to calculate the return on stocks andbonds from the databases Refinitiv Eikon and Refinitiv Datastream, respectively. The samplein the study amounted to 7271 and 1526 observations. Through a quantitative method anddeductive approach, the study has been based on the theory regarding FTQ to investigatehow the correlation has changed. Furthermore, regressions have been used to ensure theimpact on the level of the correlation and how a low interest rate climate affects the strengthof the FTQ. Conclusion: The result shows a weak negative correlation between returns on stocks andbonds during the time period, with four different structural breaks during the period.Furthermore, the results show that a low yield environment has weakened the strength of theFlights to Quality that have occurred in Sweden between 1993 and 2022. This studycontributes to the literature in the field of stock-bond return correlation and the field of lowyield effects on financial markets

Flight to Quality: Does the interest rate affect investors' reallocation of capital? : A quantitative study regarding the transfer of capital from stocks to bonds in Sweden over the past 30 years and the impact of interest rate levels

Bakgrund: Kapital på börsen förflyttas fram och tillbaka mellan olika tillgångar, vilket ären naturlig del av diversifieringen i portföljer. När osäkerheten ökar i marknaden väljerinvesterare normalt att förflytta kapital från aktier till säkrare tillgångar som exempelvisobligationer, vilket beskrivs som Flight to Quality (FTQ). Däremot har räntorna efter denglobala finanskrisen 2008 varit historiskt låga och under vissa perioder negativa, vilket i sintur försvagar förflyttningen. Sverige har här utmärkt sig, genom att till skillnad från USA,fortsatt att sänka räntan och legat på låga nivåer under en väldigt lång tid. Därmed uppstårfunderingar kring hur förflyttningar av kapital har sett ut i Sverige de senaste 30 åren, samthur det senaste lågränteklimatet påverkar. Syfte: Syftet med studien är att undersöka förhållandet mellan avkastningen på noteradeobligationer och aktier i Sverige från 1993 till 2022. Studien ska även undersöka hur enlågräntemiljö påverkar förhållandet. Metod: OMXSPI samt BMSD10Y har använts för att beräkna avkastningen på aktierrespektive obligationer från databaserna Refinitiv Eikon samt Refinitiv Datastream. Urvaleti studien uppgick till 7271 respektive 1526 observationer. Genom en kvantitativ metod ochdeduktiv ansats har studien utgått från teorin gällande FTQ för att undersöka hurkorrelationen förändrats. Vidare har regressioner använts för att säkerställa påverkan pånivån av korrelationen samt hur ett lågränteklimat påverkar styrkan i FTQ. Slutsats: Studiens resultat påvisar att korrelationen mellan aktier och obligationer undertidsperioden har varit svagt negativ med fyra olika strukturella förändringar under perioden.Vidare visar studiens resultat att ett lågränteklimat under perioden har försvagat styrkan iFTQ:er som inträffat i Sverige mellan 1993 och 2022. Studien bidrar till litteraturen inomområdet korrelation mellan aktier och obligationers avkastningar, samt litteraturen kringlågränteklimats påverkan på finansiella marknader.Background: Capital on the stock exchange is moved back and forth between differentassets, which is a natural part of the diversification of portfolios. When uncertainty increasesin the market, investors normally choose to move capital from equities to safer assets such asbonds, which is described as Flight to Quality (FTQ). On the other hand, interest rates afterthe global financial crisis in 2008 have been historically low and in some cases negative,which in turn weakens the capital movement. Sweden has distinguished itself, in that unlikethe United States, it has continued to lower its interest rates and have kept them at low levelsfor a very long time. This raises concerns about how capital movements over the past 30 yearshave developed in Sweden, and how the recent low interest rate climate is affecting. Purpose: The purpose of the study is to investigate the relationship between returns onstocks and bonds in Sweden from 1993 to 2022. The study will also investigate how a lowyield environment effects the relationship. Method: OMXSPI and BMSD10Y have been used to calculate the return on stocks andbonds from the databases Refinitiv Eikon and Refinitiv Datastream, respectively. The samplein the study amounted to 7271 and 1526 observations. Through a quantitative method anddeductive approach, the study has been based on the theory regarding FTQ to investigatehow the correlation has changed. Furthermore, regressions have been used to ensure theimpact on the level of the correlation and how a low interest rate climate affects the strengthof the FTQ. Conclusion: The result shows a weak negative correlation between returns on stocks andbonds during the time period, with four different structural breaks during the period.Furthermore, the results show that a low yield environment has weakened the strength of theFlights to Quality that have occurred in Sweden between 1993 and 2022. This studycontributes to the literature in the field of stock-bond return correlation and the field of lowyield effects on financial markets

The Microstructure and the Ex-day effect : Does the Microstructure affect the Swedish stock market?

Bakgrund: En fungerande kapitalmarknad är en förutsättning för en nations innovation,vilket i sin tur är fundamentalt för att uppnå ekonomisk tillväxt. Därav blir förståelsen för hurkapitalmarknaden fungerar av största vikt. En av de vanligaste frågorna investerare ochforskare ställer sig är huruvida marknader är effektiva? Kan investerare utgå ifrån attkapitalmarknaden är effektiv och att alla handlar på samma information? Frågan är viktigeftersom kapitalmarknaden är uppbyggd på ett förtroende hos allmänheten, om dettaförtroende raseras kan det få förödande konsekvenser för nationen, utifrån svårigheter medkapitalallokeringen. Denna studie undersöker, med utgångspunkt från effektiva marknader,fenomenet kallat ex-dagseffekten. Finns det prisavvikelser på marknaden och iförekommande fall, finns det en förklaring till detta? Utifrån det undersöker studien specifiktmikrostrukturen som förklaring till den potentiella prisavvikelsen. Syfte: Syftet med studien är att undersöka, analysera, samt förklara förekomsten av exdagseffektenoch dess relation med mikrostrukturen på OMX Stockholm Large Cap,respektive Mid Cap och Small Cap. Metod: Utifrån studiens behov att sammanställa en större mängd data har en kvantitativforskningsstrategi använts. Studiens sekundärdata är insamlad för utdelande bolag noteradepå OMX Stockholm Large, Mid samt Small Cap mellan årtalen 2016 och 2019. Insamladdata har sedan sammanställts till paneldata, vilken ligger till grund för studiens t-test samtmultipla regressioner. Slutsats: Utifrån studiens t-test påvisas att ex-dagseffekten föreligger på studiens utvaldamarknad. Vidare, utifrån studiens regressioner utläses det att mikrostrukturen har en negativpåverkan på PDR. Då förekomst av mikrostrukturen påvisas kan studien inte uttala sig omhuruvida marknaden som undersökts är ineffektiv eller ej.Background: A functioning capital market is a prerequisite for the innovation of a nation,which in turn is fundamental to achieve economic growth. Hence, the understanding of howthe capital market operates becomes of paramount importance. One of the most commonquestions investors and researchers ask themselves is whether markets are efficient? Caninvestors assume that the capital market is efficient and that everyone trades on the sameinformation? The question is important because the capital market is built upon publicconfidence, and if this trust is destroyed, it can have devastating consequences for the nation,based on difficulties with capital allocation. This study examines, based on efficient markets,the phenomenon called the ex-day effect. Are there price deviations in the market, and ifapplicable, is there an explanation for this? Based on this, the study specifically examines themicrostructure as an explanation for the potential price deviation. Purpose: The purpose of the study is to investigate, analyze, and explain the existence of theex-day effect and its relationship with the microstructure of OMX Stockholm Large Cap, MidCap and Small Cap. Method: Based on the study's need to compile a larger amount of data, a quantitativeresearch strategy has been used. The study's secondary data is collected for distributingcompanies listed on OMX Stockholm Large, Mid and Small Cap between the years 2016 and2019. Collected data has then been compiled into panel data, which is the basis for the study'st-test and multiple regressions. Conclusion: Based on the study's t-test, it is demonstrated that the ex-day effect is present inthe study's selected market. Furthermore, based on the regressions models the study used, itcan be deducted that the microstructure has an impact of PDR. Since the presence of themicrostructure is detected, the study cannot comment on whether the market examined isinefficient or not

Spatial and temporal skin blood volume and saturation estimation using a multispectral snapshot imaging camera

Hyperspectral imaging (HSI) can estimate the spatial distribution of skin blood oxygenation, using visible to near-infrared light. HSI oximeters often use a liquid-crystal tunable filter, an acousto-optic tunable filter or mechanically adjustable filter wheels, which has too long response/switching times to monitor tissue hemodynamics. This work aims to evaluate a multispectral snapshot imaging system to estimate skin blood volume and oxygen saturation with high temporal and spatial resolution. We use a snapshot imager, the xiSpec camera (MQ022HG-IM-SM4X4-VIS, XIMEA (R)), having 16 wavelength-specific Fabry-Perot filters overlaid on the custom CMOS-chip. The spectral distribution of the bands is however substantially overlapping, which needs to be taken into account for an accurate analysis. An inverse Monte Carlo analysis is performed using a two-layered skin tissue model, defined by epidermal thickness, haemoglobin concentration and oxygen saturation, melanin concentration and spectrally dependent reduced-scattering coefficient, all parameters relevant for human skin. The analysis takes into account the spectral detector response of the xiSpec camera. At each spatial location in the field-of-view, we compare the simulated output to the detected diffusively backscattered spectra to find the best fit. The imager is evaluated for spatial and temporal variations during arterial and venous occlusion protocols applied to the forearm. Estimated blood volume changes and oxygenation maps at 512x272 pixels show values that are comparable to reference measurements performed in contact with the skin tissue. We conclude that the snapshot xiSpec camera, paired with an inverse Monte Carlo algorithm, permits us to use this sensor for spatial and temporal measurement of varying physiological parameters, such as skin tissue blood volume and oxygenation.Funding Agencies|Centre for Industrial Information Technology (CENIIT) at Linkoping University; SEMEOTICONS (SEMEiotic Oriented Technology for Individuals CardiOmetabolic risk self-assessmeNt and Self-monitoring) [611516]</p

Estimation of skin microcirculatory hemoglobinoxygen saturation and red blood cell tissue fractionusing a multispectral snapshot imaging system : a validation study

Significance: Hemoglobin oxygen saturation and red blood cell (RBC) tissue fraction are important parameters when assessing microvascular status. Functional information can be attained using temporally resolved measurements performed during stimulus–response protocols. Pointwise assessments can currently be conducted with probe-based systems. However, snapshot multispectral imaging (MSI) can be used for spatial–temporal measurements. Aim: To validate if hemoglobin oxygen saturation and RBC tissue fraction can be quantified using a snapshot MSI system and an inverse Monte Carlo algorithm. Approach: Skin tissue measurements from the MSI system were compared to those from a validated probe-based system during arterial and venous occlusion provocation on 24 subjects in the wavelength interval 450 to 650 nm, to evaluate a wide range of hemoglobin oxygen saturation and RBC tissue fraction levels. Results: Arterial occlusion results show a mean linear regression R2 = 0.958 for hemoglobin oxygen saturation. Comparing relative RBC tissue fraction during venous occlusion results in R2 = 0.925. The MSI system shows larger dynamic changes than the reference system, which might be explained by a deeper sampling including more capacitance vessels. Conclusions: The snapshot MSI system estimates hemoglobin oxygen saturation and RBC tissue fraction in skin microcirculation showing a high correlation (R2 &gt; 0.9 in most subjects) with those measured by the reference method.Funding: Swedens Innovation Agency VINNOVA via the programs Swelife and MedTech4Health [2017-01435, 2019-01522]; CENIIT research organization within Linkoping University [11.02]</p