• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1395
  • 1357
  • 826
  • 49
  • 48
  • 46
  • 43
  • 39
  • 26
  • 8
  • 6
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 4033
  • 4033
  • 771
  • 713
  • 703
  • 592
  • 590
  • 590
  • 590
  • 537
  • 516
  • 501
  • 475
  • 470
  • 426
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Three essays on the Covid-19 crisis on household food security. Evidence from Ethiopia, Uganda, and Mozambique

Squarcina, Margherita 30 March 2023 (has links)
The COVID-19 pandemic brought about disruptive consequences to many people’s livelihoods around the world. The package of restrictions to contrast the health crisis caused a contraction of income and employment, on the demand side, and a disruption of domestic and global value chains, on the supply side. In many low-income economies, the crisis exacerbated an already fragile situation, raising concerns in terms of food insecurity and malnutrition. However, given the peculiar characteristics of the COVID-19 shock, not all individuals are expected to be affected in the same way. Nevertheless, evidence of the ultimate impact on food security, and the mechanisms of transmission, is still scarce. This thesis aims to address this literature gap, providing evidence for three African countries. Specifically, the study analyses the change in terms of food production and food consumption, as well as their relationship, in the aftermath of the COVID-19 outbreak, disentangling the heterogeneous impact over different types of households and different segments of the food value chain. To answer the proposed research questions, the study uses the most appropriate econometric techniques, which include a longitudinal model with household fixed effects, a structural equation model, and a cross-sectional model. What emerges is that the COVID-19 crisis severely impacted both household employment and income in 2020, the more so the longer the time length from the pandemic onset. The shock operated through two main channels of transmission, namely food value chain disruption and job loss, ultimately affecting household food security and child nutrition. The study also highlights the importance of considering the specific context under analysis and distinguishing between different types of households, specifically their market positioning when considering agricultural households.
202

Gestalting av en kris : En retorikanalys av covid-19 dokumentärer på SVT

Yazdan Abad, Maryam January 2023 (has links)
Under historien har människor drabbats av olika samhällskriser. Den första fallet av covid-19 upptäcktes i staden Wuhan i december 2019. Den 31 januari 2020 bekräftades första fallet i Sverige. Myndigheter, regioner, kommuner och andra aktörer har genomfört olika insatser för att hantera krisen. Både individer och samhälle påverkas när det kommer kriser. En kris hanteras på olika sätt av individer och samhället i olika delar av världen, beroende på olika förutsättningar och situationen där man befinner sig. Olika strategier används av myndigheter för att hantera en kris. Efter en pandemi eller samhällskris följer olika konsekvenser. Några exempel på konsekvenser som kan förekomma under och efter en kris kan vara ekonomisk kris, sämre hälsa och begränsad social interaktion och så vidare. En pandemi får konsekvenser för människor under tiden som pandemin pågår. Vissa drabbas mer och vissa mindre beroende på miljö, situationen, fattigdom, välfärd och andra faktorer. Ambitionen med denna uppsats är att undersöka hur covid-19 har gestaltats i dokumentärer på SVT. Filmen heter ”Pandemin” och består av 3 avsnitt. Filmskaparen heter Alice Henley och filmen är producerad för BBC, KEO film. Dokumentärer som analyseras i uppsatsen har gestaltats genom intervjuerna av människor från 21 länder. Detta för att kunna undersöka hur människor har upplevt pandemin runt omkring i världen. Analysen av dokumentärerna genomförs med hjälp en retorisk metod. Bevismedel som används inom retoriken är Logos, Pathos och Ethos. Dokumentärers uppbyggnad analyseras med hjälp av Nichols 6 modus. Tanken är att analysera metoden eller metoder som filmskaparen använt sig av för att producera filmerna och samtidigt att reda ut vilket budskap som filmskaparen har gestaltat. Ytterligare undersöks vad en samhällskris innebär, vilka faser vi går igenom under en kris, vilka konsekvenser om kan följa efter en kris samt vad som kan göras för att hantera konsekvenserna som en samhällskris medför. Detta analyseras med hjälp av annat material så som böcker som handlar om krishantering. Det teoretiska ramverket tar upp bevismedel i retorisk metod och krismedvetenhet, konsekvenser av krissituationer och krishantering. Krishanteringscykel visar att det finns några faser som en kris går igenom. Dessa faser är: förebyggandefasen, föreberedandefasen, responsfasen och återuppbyggnadsfasen. Några nyckelord: Krishantering, krissamhället, covid och retorik.
203

High-throughput methods to investigate the function and pharmacological inhibition of viral proteases

Hong, Seo Jung January 2023 (has links)
Viral pathogens have plagued human civilizations since ancient times and continue to pose a serious and constant global threat to not only human health but all facets of life. To date, more than 200 viruses capable of infecting humans have been identified, and the combined efforts of the academic and pharmaceutical sectors have yielded both extensive understanding of the biology and pathology of the viral infections as well as breakthrough interventions against a number of devastating diseases such as those caused by HIV (human immunodeficiency virus) and HCV (hepatitis C virus). In late 2019, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the etiological agent of COVID-19 (coronavirus disease 2019), rapidly spread worldwide, leading to detrimental public health and socioeconomic crises. While the immediate response of the scientific community to the pandemic, which involved investigation of the disease and discovery of several therapeutic options at an unprecedented pace, has been impressive, this recent experience exposes the serious need to continuously fortify our fundamental knowledge of virology and equip our antiviral arsenal in preparation for future outbreaks. Moreover, given the scale of the challenge at hand, it highlights the value in the development and application of experimental approaches that accelerate the rate at which this information is obtained. In this dissertation, we utilize various techniques that allow high-throughput analysis of the SARS-CoV-2 3CL (3-chymotrypsin-like) protease to better understand its functional landscape as a favorable therapeutic target of the virus, and to investigate its response in developing resistance against the clinically used protease inhibitor, nirmatrelvir, at scale. We further expand our efforts to develop a platform for multiplexed drug screening that has the capacity to detect viral protease inhibitors for not only coronaviruses but also other targets across six additional virus families. Using this approach, we are able to rapidly identify broad-acting inhibitors, which are favorable for pandemic preparedness purposes where the exact nature of the future threat is difficult to predict a priori. To perform our studies, we make use of a variety of model systems, from a simple yeast-based system for detecting viral protease activity to the passaging of live virus within cultured human cells. Utilizing our yeast-based reporters, we comprehensively profile the activity landscape of all possible single mutants of the SARS-CoV-2 3CL protease via deep mutational scanning (DMS), uncovering its general malleability while also identifying several immutable regions within the enzyme that can serve as targets for the design of the next generation of protease inhibitors. Among the sites that show tolerance to changes, we predict E166 to be a residue that may confer nirmatrelvir resistance upon mutation based on available structural data which reveal its critical role in the binding of the drug to the active site. We prove this to be true by demonstrating a 265-fold loss in EC50 for the E166V mutant relative to the wild type protease within the recombinant virus. Recognizing that the plasticity of the enzyme could translate to a lower genetic barrier to resistance, we extend our investigation to study the whole virus response to nirmatrelvir at scale via in vitro passaging of SARS-CoV-2 in increasing concentrations of the drug. Upon examining 53 independent viral lineages to explore the ways by which resistance can be acquired, we identify a total of 23 mutations that arise in often non-overlapping combinations, with T21I, P252L, and T304I being the most common precursor mutations within all analyzed mutational trajectories. Validation of select single, double, and triple mutants based on the frequency of their appearance reveals that most single mutations, including the aforementioned founder mutations, confer low-level resistance (~5 – 6 fold) while greater resistance is acquired with the accumulation of additional mutations. Moreover, some mutations, such as T21I and L50F, appear to mediate, through a compensatory mechanism, the acquisition of secondary mutations such as E166V, which alone may confer much greater resistance but also cause significant loss in replicative fitness. Overall, the myriad of solutions that exist for the virus to escape the drug further corroborate the malleability of the SARS-CoV-2 3CL protease as established by our initial DMS study. These findings also establish a foundation for extended analysis of the mechanism of resistance and informed drug design. Lastly, by introducing additional viral proteases into our yeast cellular chassis and labelling each model with a set of unique DNA-barcodes, we develop a method of screening a pool of 40 unique protease targets simultaneously against small molecule libraries. Using this platform, we screen 2,480 structurally diverse compounds, and identify and orthogonally validate a series of broad-acting coronavirus 3CL protease inhibitors with a chromen-2-one structure. Together, the work described in this thesis underline the importance of innovative high-throughput approaches to investigating biology as demonstrated by their application to viral protease research.
204

A Comprehensive Analysis of Mortality due to COVID-19 in Long-Term Care / Mortality due to COVID-19 in Canadian Long-Term Care

Hothi, Harneet January 2022 (has links)
The long-term care (LTC) sector in Canada has experienced high numbers of COVID-19 deaths. However, there is a paucity of data on the impact of COVID-19 in LTC by different socio- demographic variables and in LTC homes within different regions. Additionally, the question remains as to how exactly and by how much the pandemic has impacted mortality in LTC in comparison to previous years’ mortality. Ranges for expected mortality by sex, province, and age, for the 2020-21 fiscal year were determined by creating forecasts and confidence intervals based on mortality trends in the preceding four fiscal years. These ranges were then compared to the actual mortality data in 2020-21. Comparisons between expected ranges and actual data were also conducted for the number of active residents, admissions, and discharges in LTC by sex, province, and age. Further, mortality ratios were created and studied by sex, province, age, and health region/authority/local health integration network. Overall, the number of deaths in LTC in Canada increased beyond the expected ranges in quarter one and three of 2020-21, and the patterns in death ratios were similar. Increases were exceptional in comparison to the peaks in deaths in previous years for specific variables, but not all variables. Most commonly, the number of active residents and admissions decreased in 2020-21 and the number of discharges from LTC did not change in quarter one and three and decreased in quarter two and four. However, importantly, these trends also varied across variables. This was the first study to comprehensively examine mortality due to COVID-19 in LTC overall, and by multiple socio- demographic variables while elucidating the complexity in the study of mortality in LTC. Further research is required to concretely understand mortality in LTC by different variables and regions. / Thesis / Master of Arts (MA) / This study examined mortality due to COVID-19 from April 2020 to March 2021 in Canadian long-term care (LTC) homes by sex, age, province, and health region. Ranges of predicted values for mortality were created from mortality data from previous years and then compared with actual mortality. The number of active residents, admissions, and discharges were also examined by sex, age, and province to factor for changes in the population at risk. Overall, mortality increased in some quarters (April-June 2020 and October-December 2020) but was not always exceptional, as similar mortality rates had been observed in the four years prior to the pandemic. Also, the increase in mortality was seen mostly among younger residents (65 to 85); mortality remaining stable for the 85+. Further research is still required to better understand mortality in LTC by regional characteristics.
205

Host responses to viral infection and genomic variation during pandemic transmission

Turcinovic, Jacquelyn 11 January 2024 (has links)
This dissertation is a tale of two emerging human pathogens. The first is a genus of viruses, orthoebolaviruses, which periodically cause outbreaks in humans in central and western Africa following spillover from animal reservoirs. Outbreaks of orthoebolaviruses have high rates of morbidity and mortality and can cause symptoms ranging from vomiting and diarrhea to hemorrhage. Understanding both how the virus evolves to fit its host as well as how the host reacts to viral infection is paramount to understanding what determines whether an infected patient will die or survive orthoebolavirus infection. To understand how orthoebolavirus genomic plasticity allows the virus to optimize itself to its host, I analyzed viral genomic sequencing data from two Orthoebolavirus species during serial passage in tissue culture: Ebola virus and Sudan virus. In low-passage Sudan virus, I discovered a true viral quasispecies in which three to four viral genotypes circulated within the same stock. I then examined how that quasispecies reacted when put into a nonhuman primate model (NHP) of infection; unexpectedly, we saw that the mix of genotypes in the challenge stock matched the mix of genotypes seen at clinical endpoint. To begin to understand what a successful immune response to orthoebolavirus infection entails, I characterized the circulating transcriptomic response in two survival models of Ebola virus disease. In a uniform survival model where NHPs were challenged with Bombali virus, I showed that NHPs have a clear and robust response to infection despite varying symptom severity. In a Taï Forest virus challenge model with ~44% survival, I showed that NHPs that succumb do so in a uniform manner consistent with other models of Ebola virus disease. In contrast, survivors were highly variable in their response to infection: some mimicked the non-survivor response but recovered in time, while others hardly responded at all. After covering orthoebolavirus genomic plasticity and the host response to infection in the first and second sections, respectively, I will then shift to the other focus of my dissertation work: SARS-CoV-2 and molecular epidemiology. SARS-CoV-2 swept the globe in 2020 following spillover into humans from an animal reservoir in late 2019, and surveillance sequencing of viral genomes early in the pandemic showed the virus was rapidly adapting to its new host. I leveraged this high mutation rate to spin up a molecular epidemiology operation for Boston Medical Center (BMC) and Boston University (BU). From mid-2020 through spring 2022, I catalogued, processed, sequenced, and analyzed samples and viral genomes from over 7,000 SARS-CoV-2 patient swabs. I worked with contact tracing teams, physicians, and infection control from BU and BMC to quantify viral introductions, identify transmission chains, and integrate the genetic linkages with traditional epidemiological data. / 2025-01-11T00:00:00Z
206

Träningsmängd och träningsdeltagandets förändring för fotbollsutövande ungdomar, ur ett ledarperspektiv : En kvalitativ studie om träningsgruppers påverkan av pandemin i en fotbollsklubb

Larsson, Adam January 2022 (has links)
Introduktion: Genom att ett virus (Covid-19) upptäcktes i Kina i slutet av 2019 som senare ledde till en pandemi, blev den fysiska aktiviteten inte bätt- re. Restriktioner kom efter varandra, äldre människor rekommenderades att inte vistas bland andra människor, skolor fick stänga ner och många idrotter fick inte utföras vilket ledde till att den fysiska aktiviteten minskades väldigt mycket. Syfte: Syftet med arbetet var att ta reda på om/hur träningen för 10-15 åring- ar har förändrats i en lokal fotbollsklubb på grund av pandemin ur ett tränar- perspektiv. Även hur tränarna jobbat för att bibehålla det goda träningsinne- hållet. Metod: I denna studie har en kvalitativ forskningsmetod genomförts i form av en enkät. Enkätfrågorna var av formen öppna frågor och analyserades med hjälp av innehållsanalys genom att dra slutsatser och genom tolkning av sva- ren från deltagarna. Frågorna skickades ut till 17st deltagare varav 15st av dessa valde att vara med i studien och inkom med svar på de utskickade frå- gorna. Resultat: Det visar sig att grupperna inte påverkas så mycket av pandemin. Tränarna har inte märkt någon märkbar förändring vad gäller antal deltagare i träningsgruppen om de jämför med deras grupp nu och innan pandemin. Trä- ningsmängden har snarare ökat istället för att minska för att inomhusträningar fick stänga ner men gjordes om till fler utomhusträningar. Slutsats: Av de svar som kom in från deltagarna som var med i studien visa- de det sig att i den lokala fotbollsklubben som studien är analyserad kring har Covid-19-pandemin inte påverkat barn och ungdomar vad gäller träning av fotboll. Restriktioner genomfördes för träningsgrupperna men påverkade inte grupperna i så stor utsträckning att de blev påverkade negativt. Nyckelord: Covid-19, deltagare, pandemi, träning, träningsgrupp
207

Evaluation des psychischen Belastungserlebens von Gesundheitspersonal während der Sars-CoV-2 Pandemie – Eine Beurteilung anhand von Umfrageergebnissen der anästhesiologischen Abteilung am Universitätsklinikum Würzburg / Evaluation of the psychological stress experience of healthcare staff during the Sars-CoV-2 pandemic - An assessment based on survey results from the anaesthesiology department at the University Hospital of Würzburg

Göpfert, Dennis January 2024 (has links) (PDF)
Die Evaluation des psychischen Belastungserlebens bei Intensivpersonal zeigte während der ersten Covid-19 Welle eine stabile psychosoziale Situation mit Angst um Angehörige und soziale Isolierung als Hauptbelastungsfaktoren. Weiterhin konnten bestimmte vulnerable Gruppen identifiziert werden. / The evaluation of the psychological stress experienced by intensive care staff during the first Covid-19 wave showed a stable psychosocial situation with fear for relatives and social isolation as the main stress factors. Furthermore, certain vulnerable groups were identified
208

Hur fungerar det att leda anställda via pixlarna i dataskärmen? : Distansarbetes påverkan på chefer och dess ledarskap, fokus på tiden efter Covid-19 pandemin / How does it work to lead employees through the pixels in the computer screen? : Remote works impact on managers and its leadership, with focus on the time after the Covid-19 pandemic.

Svalland Fridholm, Tuva, Åhs Hagström, Tova January 2023 (has links)
how does it work to lead employees through the pixels in the computer screen? Remote work's impact on managers and its leadership, with focus on the time after the Covid-19 pandemic.   Today's society is becoming more digitized, and the growth has a constant impact on the corporate world. As a result of the Covid-19 pandemic, the rise of digitization was forced, and companies were faced with a change from the physical work environment to the remote work environment. Remote work and remote leadership therefore became more common in the Swedish labor market.   The aim of the study is to gain a deeper understanding of how leadership has been affected by remote work, with a focus on the time after the Covid-19 pandemic. This will be investigated by obtaining knowledge from previous research. Further by examining the experiences of managers and employees. The study does not seek employees' experiences regarding remote work but aims to acquire information about the impact of remote leadership, from an additional dimension.   The theory chapter highlights what knowledge has previously been obtained in the subject. The theory is divided into three primary components based on the three research questions that the study addresses. Next, the method chapter describes the various methods and approaches the study has applied. The method applied in the essay is a qualitative approach with interview as method choice.   This study has gained a deeper understanding of remote leadership by studying the phenomenon both theoretically and empirically. The three given components are intertwined and depending on how each part is handled it affects the outcome of an effective remote manager. Overall, the study shows that a successful remote manager must be committed to both the development and the employees. Another success factor for a remote manager is to use the trust that the manager creates towards the work team. According to the study, continuous varied communication must be applied where the remote manager makes use of the opportunity of new emerging digital media.   The study indicates that companies should consider when evaluating remote work the business financial advantages that can be capitalized on. They should also pay further attention to the challenges that may arise; however, these challenges should not alarm managers, but rather be seen as a motivation.
209

Enhancing Delivery of Operations by Optimizing the Omni-Channel Supply Chain through Delivery as a Service

Kaplan, Marcella Mina 24 May 2021 (has links)
The need for delivery grew significantly during the COVID-19 pandemic because people avoided activities in public to limit the spread of the virus. The purpose of this research was to evaluate how the pandemic influenced many individual's delivery preferences through the administration of a stated preference survey targeted at residents in the New River Valley, Virginia. Conclusions revealed from the survey show that people want more efficient and accessible delivery services. A new delivery ecosystem called Delivery as a Service (DaaS) was developed using the input from the survey, existing service-based models being widely implemented in many industries, and emerging technologies. This thesis details a framework for DaaS derived by defining major actors, characteristics, and a method to measure the effectiveness of a DaaS system. This comprehensive definition of integrated delivery services illustrates areas for future research to further optimize the DaaS system. DaaS has the potential to significantly change the current delivery ecosystem through increased delivery accessibility and efficiency. Goods can be brought to users at a faster rate and on a larger scale. Autonomous vehicle and drone delivery technologies can significantly reduce the cost while correspondingly reducing the time of delivery. DaaS is a concept that is needed for people to thrive in modern times and brings the opportunity to provide added benefits to even rural areas. / Master of Science / The need for delivery grew significantly during the COVID-19 pandemic because people avoided activities in public to limit the spread of the virus. The purpose of this research was to evaluate how the pandemic influenced many individual's delivery preferences through the administration of a stated preference survey targeted at residents in the New River Valley, Virginia. Conclusions revealed from the survey show that people want more efficient and accessible delivery services. A new delivery ecosystem called Delivery as a Service (DaaS) was developed using the input from the survey, existing service-based models being widely implemented in many industries, and emerging technologies. This thesis details a framework for DaaS derived by defining major actors, characteristics, and a method to measure the effectiveness of a DaaS system. This comprehensive definition of integrated delivery services illustrates areas for future research to further optimize the DaaS system. DaaS has the potential to significantly change the current delivery ecosystem through increased delivery accessibility and efficiency. Goods can be brought to users at a faster rate and on a larger scale. Autonomous vehicle and drone delivery technologies can significantly reduce the cost while correspondingly reducing the time of delivery. DaaS is a concept that is needed for people to thrive in modern times and brings the opportunity to provide added benefits to even rural areas.
210

Effectiveness Evaluation of COVID-19 Regulations in Collegiate Sports: Quantifying Player Proximity and Workload During Soccer Training

Andreano, Kylea Joelle 26 May 2023 (has links)
The COVID-19 pandemic and subsequent shutdown and regulations have drastically altered the world of competitive sports. The global shutdown beginning in March 2020 put a significant strain on athlete's ability to train, as many fitness centers were closed to prevent disease transmission. When it was deemed that athletic competition was safe to resume, there were still strict regulations in place to support public health efforts. This retrospective study primarily aims to evaluate the effectiveness of COVID-19 safety regulations in competitive sports. Specifically, the successfulness to correctly implement social distancing guidelines is of high interest. A secondary aim of this study is to assess changes in workload during preseason training before COVID-19, during the time of heavily enforced COVID-19 regulations, and following strict COVID-19 restrictions, as workload can be a predictor of athletic injury. Participants in this study included Virginia Tech Women's Soccer athletes and data were analyzed from the first 9 preseason training sessions during the 2019, 2020, 2021 and 2022 seasons. Data were generated from participants wearing the STATSports Apex device during training. A custom MATLAB spatiotemporal program developed by the Williams Research Group was utilized to determine player proximity. Total distance (m) and high metabolic load (HMLD) (au), and high-speed distance (HSD) (m) metrics were analyzed to understand changes in participant workload. It was found that overall the Virginia Tech Women's Soccer Team's implementation of the guidelines was effective, as there were no invasion violations during the 2020 preseason sample. / Master of Science / The COVID-19 pandemic has forever changed the world as we know it. Competitive sports are no exception. The worldwide shutdown as a result of COVID-19 made it difficult for athletes to train while in isolation, as most facilities were closed to prevent disease transmission. When sports were able to continue again, there were still barriers preventing normal practices and competition. Athletes were asked to make every effort to maintain social distancing, even during training sessions. The main purpose of this study is to evaluate how well NCAA Division 1 Women's Collegiate Soccer players maintained social distancing during preseason practices. A secondary goal of this study is to uncover changes in workload from before COVID-19 (2019), during strict COVID-19 regulations (2020), and when COVID-19 restrictions had been less enforced (2021 and 2022). The reasoning for this is that how much work an athlete does can be indicative of risk for injury. If an athlete does significantly more work than usual, there is a higher risk of injury. This study will use global positioning systems (GPS) and measures that reflect workload collected from Virginia Tech Women's Soccer players. It was found that the players remained farther apart during the 2020 season due to the emphasis on social distancing, and that the workload will show a gradual increase to prevent injury. Overall, the study found that the COVID-19 regulations were effectively implemented among the Virginia Tech Women's Soccer Team in the 2020 preseason when restrictions were the highest.

Page generated in 0.0545 seconds