Cette thèse s'intéresse aux fondements du comportement des usagers face à la congestion dans les transports publics. Elle se compose de trois essais distincts. Les deux premiers essais examinent l'adaptation des usagers au manque de ponctualité et à l'inconfort. Le troisième essai offre une analyse empirique de l'effet « foule ». Dans le premier chapitre, je présente un modèle de compétition bimodale entre une ligne de transport public sujette aux retards, et un mode alternatif. A l'équilibre du marché, le niveau de fiabilité choisi par la firme en charge des transports publics augmente avec le prix du mode alternatif via un effet « demande » évoquant l'effet Mohring. L'étude de la qualité de service optimale montre que souvent, la fiabilité des transports publics et donc leur fréquentation à l'équilibre sont inférieurs à ce qu'ils seraient à l'optimum social. Dans le second chapitre, afin d'étudier le coût de l'inconfort et ses implications quant au choix de l'heure de déplacement, je développe un modèle structurel dans lequel les usagers des transports public choisissent entre voyager dans un véhicule bondé et arriver à destination à l'heure désirée ou alors voyager plus tard ou plus tôt pour éviter la foule. J'établis la distribution des usagers parmi les véhicules à l'équilibre et à l'optimum social, et montre que l'optimum social peut être décentralisé par une tarification fine par véhicule. Les propriétés du modèle sont comparées avec celles du modèle du « bottleneck » et des modèles de congestion routière. Dans le troisième chapitre, j'analyse l'influence de la densité d'usagers sur la satisfaction liée au confort durant un déplacement en transport public. De plus, je décris l'anatomie de l'effet « foule » en testant différents aspects (odeur, bruit, position debout...) comme des causes d'inconfort lorsque la densité d'usagers augmente. J'identifie un net effet « foule » : en moyenne, un usager supplémentaire par mètre carré diminue de 1 la satisfaction liée au confort qui est mesurée sur une échelle de 0 à 10. Je ne trouve pas de corrélation entre temps de transport et l'effet « foule ». Cependant, cet effet augmente avec le revenu des usagers. Trois causes de désutilité liée à la foule sont identifiées : une plus grande probabilité de devoir voyager debout, un usage limité du temps, et des conditions de déplacement plus bruyantes. Ces désagréments sont plus importants chez les femmes et les usagers les plus aisés. / This dissertation addresses the foundations of user’s behavior with respect to the congestion in public transport. It is made of three distinct essays. The two first essays investigate how users get used to lack of punctuality and crowding. The third essay presents an empirical analysis of the crowding effect. In the first chapter, I consider the modeling of a bi-modal competitive network involving a public transport mode, which may be unreliable, and an alternative mode. The public transport reliability set by the public transport firm at the competitive equilibrium increases with the alternative mode fare, via a demand effect. This is reminiscent of the Mohring Effect. The study of the optimal service quality shows that often, public transport reliability and thereby patronage are lower at equilibrium compared to first-best social optimum. In the second chapter, to study the behavioral implications and costs of crowding, I develop a structural model in which public transport users face a choice between traveling in a crowded train and arriving when they want, and traveling earlier or later to avoid crowding but arriving at an inconvenient time. I derive the user equilibrium and socially optimal distribution of passengers across trains, show how the optimum can be decentralized using train-specific fares, and characterize the welfare gains from optimal pricing. Properties of the model are compared with those obtained from the bottleneck and flow congestion models of road traffic. In the third chapter, I investigate the influence of in-vehicle crowding on the comfort satisfaction experienced during a public transport journey. Moreover, I describe the anatomy of the crowding effect by testing various nuisance factors (Smell, Noise, Standing...) as channels through which crowding may decrease the comfort satisfaction. I find a clear crowding effect: on average, an extra-user per square meter decreases by one the expected 0 to 10 scale individual well-being. I do not find any empirical evidence of this effect being intensified by the travel time. However, the crowding effect increases with the income of users. I find three causes of crowding disutility: a higher probability to stand for all or part of the journey, a poorer use of the time during the journey, and noisier travel conditions. These features of discomfort matter more for women and wealthy individuals.

This dissertation addresses the following research questions: How do physical features of high density college dormitories affect residents' perception of crowding, and what kinds of design strategies are available for alleviating the perceived crowding? The data source was responses to a self-administered questionnaire from residents of living units which were randomly sampled from three dormitories of comparable physical density at Oregon State University. Seven hypotheses were used to examine the relationship between perceived crowding and physical features associated with different settings in selected dormitories. The first hypothesis sought to clarify how selected physical variables, compared with selected social and personal variables, contributed to perceived crowding both in dormitory dwellings (floor crowding) and rooms (room crowding). For the remaining hypotheses, comparisons were made to determine if differences existed between groups living on floors with varied corridor length, floor height (distance above ground level), and bathroom location, and between groups living in rooms with varied desk location, room location, and window orientation. Using multiple regression analysis and analysis of variance as the major tools for hypothesis testing, the study found that: (1) both room and dwelling crowding were not significantly affected by the selected physical, social, and personal variables; (2) floor crowding was significantly lower among residents of short corridors and among those who shared suite rather than community bathrooms. Variations in floor level did not affect perceived crowding; (3) room crowding was not significantly affected by variations in desk location, room location, and window orientation, but rather by the interactive effects of window orientation and floor height.

Previous research has found that if a population were allowed to exceed a comfortable density level, then many catastrophic events occurred such as increased mortality among the young, cannibalism, homosexuality, and lack of maternal functions. The most influential researcher in this area is Calhoun (1962), after whose experimental design a pilot study was fashioned to replicate his results. The results of this pilot study inspired a more detailed research project of which this thesis is an account. Forty-eight albino mice of the Swiss Webster strain were divided into three groups of sixteen each. Each group consisted of ten females and six males chosen randomly; two groups were to serve as experimental groups and the other group as the control. The experimental groups were placed into apparatus 15 5/8” x 20 1/2"x 8" and the control group in an apparatus 47 7/8" x 61 1/2" x 8". The three groups were allowed to multiply freely with nesting material, food and water provided proportionately as their numbers grew. The experimental groups were allowed to overpopuate while the control group was not. There were six behavior variables noted as the experiment proceeded: (1) grooming, (2) homosexuality, (3) nest building, (4) retrieving of young, (5) fighting, and (6) mortality of the young. It was predicted that grooming, nest building, and retrieving of the young would decrease in frequency as the population increased, while fighting, homosexuality and mortality of the young would increase with the rising population density. The experiment was conducted for six months and fourteen days. The result of this experiment was a total lack of overpopulation. The two experimental groups never weaned any pups though they produced many, and the control group grew to the comfortable limits of its apparatus and then ceased weaning any further pups. In an effort to ascertain the reasons for these results, one of the experimental groups was artificially reduced in number; whereupon it promptly weaned forty-one percent of its first litter, thirty percent of its second, and none of its third. At the time of its first weaning, this group was technically overpopulated. In conclusion a hypothesis is proposed to explain the results. It is felt that each population has an innate knowledge of its comfortable limits with regard to density and will maintain this crucial density level if necessary. The group's ability to control its popu1ation is directly related to a time factor in that if a population were allowed to approach its crucial density level gradually it would not exceed it; however if there were little or no approach time, then this level would be exceeded.

Akutmottagningen har som uppdrag att handlägga patienter med akuta tillstånd inom olika specialiteter. Ett stort inflöde av patienter, långsamt genomflöde och utflöde skapar långa väntetider och överbelastning kan uppstå. Överbelastning på akutmottagningen kan ge konsekvenser inom flera områden i vårdkedjan. Patienterna riskerar att få sämre vård och längre tid till smärtlindring. Det skapar långa väntetider som i sin tur leder till missnöjda patienter och anhöriga Överbelastning kan även skapa minskad produktivitet och ökad frustration bland sjukvårdspersonal. Sjuksköterskor som arbetar på akutmottagning under överbelastning påverkas i sin yrkesutövning. Syftet med studien var att beskriva sjuksköterskors upplevelser av överbelastning på akutmottagning. Metoden var en kvalitativ deskriptiv intervjustudie med induktiv ansats. Semistrukturerade intervjuer genomfördes med sex sjuksköterskor verksamma på två olika akutmottagningar. Intervjuerna transkriberades ordagrant för att därefter analyseras utifrån en kvalitativ innehållsanalys. Resultatet presenteras i tre kategorier: att vara sjuksköterska i kaos, patientsäkerhet och att hantera sin situation. Ur sjuksköterskornas upplevelser framkom att de upplevde att miljön på akutmottagningen vid överbelastning påverkades negativt. De önskade mera tid för att skapa ett bra möte med patienten och upplevde att omvårdnaden var svår att hinna med vid dessa tillfällen. De påtalade att sekretessen inte gick att upprätthålla på en överbelastad akutmottagning. Informanterna upplevde att det fanns risker i patientsäkerheten och påtalade tre områden som extra riskfyllda: patienter med låg prioritet och lång väntetid, patienter som väntar på vårdplats och bemanning på akutmottagningen nattetid. Yrkesutövningen påverkades genom ständiga avbrott och de utvecklade med erfarenhet egna rutiner för att göra arbetet effektivt. De upplevde oro över att missa försämring/allvarliga tillstånd hos patienter och fick en känsla av maktlöshet. Sjuksköterskorna uppgav att de fann stöd i sitt team och att de kunde delegera uppgifter och kände sig trygga med att teamet tillsammans oftast kunde hantera arbetsbelastningen. För att förbättra flödet i arbetet önskade de närmare samarbete med primärvård, att läkarna hade en större förankring i teamet och att det fanns fler beslutsmässiga läkare i tjänst samt önskade bli avlastade från administrativa arbetsuppgifter som de upplevde tog tid från patientarbetet. Studien kan således visa på att överbelastning på överbelastning påverkar samtliga omvårdnadsdomäner och även om sjuksköterskorna hade förståelse för patienternas situation kunde de inte alltid uppfylla exempelvis patienternas rätt till sekretess och integritet, vilket skapade samvetsstress. Sjuksköterskornas utvecklade strategier för att underlätta arbetet skapade över tid mer stress och även den erfarna sjuksköterskan upplevde oro för att missa försämring/allvarliga tillstånd hos patienter. Att inte få gehör för påtalade brister i patientsäkerhet och arbetets förutsättningar under överbelastning kan skapa en känsla av maktlöshet. Stöd från kollegor och team ger dock möjlighet att ändå uppleva arbetet som positivt och känna en tillfredsställelse. Nyckelord: Akutmottagning; Patientsäkerhet; Sjuksköterskor; Överbelastning / The emergency department is assigned to treat patients with emergency conditions in different specialties. A large influx of patients, slow throughput and outflow creates long waiting times and Emergency department crowding can occur. Emergency department crowding can have consequences in several areas of the patient care. Patients risk getting worse care and longer time for pain relief. It creates long waiting times which in turn leads to dissatisfied patients and relatives. Emergency department crowding can also create reduced productivity and increased frustration among healthcare professionals. Nurses working on emergency reception during emergency department crowding is influenced in their professional practice. The purpose of the study was to describe nurses' experiences of emergency department crowding. The method was a qualitative descriptive interview study with inductive approach. Semi-structured interviews were conducted with six nurses working on two different emergency departments. The interviews were transcribed verbatim and then analyzed on the basis of a qualitative content analysis. The result is presented in three categories: A crowded workplace, constant concern about patient safety, and strategies to managing the situation. The experiences of the nurses found that they felt that the environment of emergency response at congestion was adversely affected. They wanted more time to create a good meeting with the patient and experienced that nursing was difficult to cope with on these occasions. They argued that privacy could not sustain with emergency department crowding. The informants felt that there were risks in uj,jpatient safety and identified three areas as extra risky: patients with low priority and long waiting time, patients waiting for care in wards and the number of crew at emergency departments at nightshift. Professional practice was influenced by constant interruptions and they developed with experience own practices to make the work efficient. They were worried about missing the deterioration / serious condition in patients and felt a lack of powerlessness. Nurses stated that they found support in their team and that they could delegate tasks and felt confident that the team could most often handle the workload. In order to improve patient flow, they wanted closer cooperation with primary care, that the physicians had a closer foundation in the team and that there were more decision-making doctors on duty and wanted to be relieved from administrative tasks that they experienced took time from patient work. Thus, the study can show that crowding affects all nursing domains and although the nurses understood the patient's situation, they could not always meet, for example, the patients' right to privacy and integrity, which created conscience stress. Nurses developed strategies to facilitate work that created more stress over time, and even the experienced nurse experienced worries about missing impairment / serious conditions in patients. Failure to address the alleged deficiencies in patient safety and the conditions during emergency department crowding can create a sense of powerlessness. However, support from colleagues and the team gives the opportunity to experience the work as positive and feeling satisfied. Keywords: Crowding; Emergency department; Nurse; Patient safety

The oncogene c-MYC has guanine-rich and complementary cytosine-rich sequences in its P1 promoter region. The P1 promoter is responsible for over 90% of the c-MYC expression. Downregulation of c-MYC expression represents a novel therapeutic approach to more than 50% of all cancers. A stable i-motif formed by the c-MYC C-rich sequence would be an attractive target for cancer treatment. We have previously shown that c-MYC promoter sequences can form stable i-motifs in acidic solution (pH 4.5-5.5). The question is whether c-MYC promoter sequence i-motif will be stable at physiological pH. In this work, we have investigated the stability of mutant c-MYC i-motif in solutions having pH values from 4 to 7 and containing co-solutes or molecular crowding agents. The crowded nuclear environment was modeled by the addition of polyethylene glycol (PEG, having molecular weights from 200 to 12000 g/mol) at concentrations of 10% to 40% w/w. Circular dichroism spectroscopy (CD) and differential scanning calorimetry (DSC) were used to establish the presence and stability of c-MYC i-motifs in buffer solutions having pH values of 4 to 7. The results of these studies are: 1) the addition of up to 20% w/w glycerol does not increase i-motif stability, 2) the addition of 30% PEG results in an increase in i-motif stability to pH values as high as 6.7, 3) i-motif stability is increased with increased PEG concentration and increased PEG molecular weight, and 4) the effects of PEG size and concentration are not linear, with larger PEGs forming DNA/PEG complexes, which destabilize the i-motif. In summary, we have shown that the c-MYC i-motif can exist as a stable structure at pH as high as 6.7 in a crowded environment. Molecular crowding, largely an excluded volume effect, drives the formation of the more compact i-motif, even at higher pH values where the cytosine imino-nitrogen is deprotonated and neutral C-C pairs can form only two H-bonds. Based on this research, it seems possible that a stable c-MYC promoter sequence i-motif could form at physiological pH and would be a reasonable drug target for new cancer therapies.

No description available.

Financial intermediaries are paramount for modern society. During the last decade, however, our reliance on these institutions have been meticulously debated, especially in the aftermath of the financial crisis. This thesis contributes to this debate with a novel perspective on loan supply changes in light of the recent events in the Swedish real estate market. More specifically, it investigates what influence housing prices have on the supply of commercial and industrial loans. This is done by estimating dynamic panel data models using a quarterly panel containing balance sheet data for 68 Swedish monetary financial institutions, during the post-financial crisis period of 2009-2017. The results indicate that housing prices do not have a significant effect on commercial and industrial loan supply. However, these loans are to a considerable degree dependent on the institutes’ earlier levels of commercial and industrial loans.

Many species naturally occupy discrete habitat patches within a mosaic of habitats that vary in quality. The Florida scrub-jay (Aphelocoma coerulescens) is endemic to Florida scrub, a habitat that is naturally patchy and greatly reduced in area over recent decades owing to development and urbanization. Because of this habitat loss, future management of Florida scrub-jays will focus on smaller, fragmented tracts of land. My study examines such a tract, Lyonia Preserve, southwest Volusia County, FL. This preserve was unoccupied by scrub-jays prior to habitat restoration. The preserve is now frequently managed exclusively for scrub-jays as a habitat island surrounded by development. Management of the preserve includes roller chopping, root raking, timbering, and "oak stripping" where islands of oak patches are left intact while the rest of the area is roller chopped. I investigate what, if any, demographic consequences may be associated with the habitat management and the spatial setting of the preserve. I used population data collected in this area since 1992 to examine population growth and responses to habitat restoration within the preserve and habitat destruction outside the preserve. I mapped territories and measured survival and recruitment of scrub-jays, and dispersal into and out of the study area, for two and a half years. Since restoration, the population has shown logistic growth, with the area supporting higher than average densities of scrub-jay family groups. Observed density of the population and territory size varied between study years. Breeder survival values were positively related to territory size and significantly lower during periods of highest observed density. However, recruitment (yearling production) showed no relationship to territory size. Dispersal to isolated habitat patches was observed; likewise, several failed dispersal events were noted. No immigration into the study area was observed; however these data may be underrepresented since not all scrub-jays in and outside of the preserve were banded, and data collection was limited during the initial colonization period. High densities inside the preserve may therefore be both a result of frequent habitat management in the form of mechanical treatment as well as crowding of individuals due to outside habitat destruction. The results indicate that carrying capacity of habitat for scrub-jays may be raised by frequent, mechanical management; however, if the area is isolated, management may result in high densities and negative demographic consequences, e.g., reduced breeder survival. Negative effects of management may be avoided by subjecting smaller areas to mechanical treatment with increased time between treatments. Land managed for Florida scrub-jays should be contiguous or connected with other scrub habitats so that surplus birds from the managed areas have a refuge and do not contribute to increased densities. Regulatory officials should use caution when allowing for "take" of scrub-jay habitat as the effects may extend beyond the local habitat being destroyed.

For systems biology, it is important to describe the kinetic and thermodynamic properties of enzyme-catalyzed reactions and reaction cascades quantitatively under conditions prevailing in the cytoplasm. While in part I kinetic models based on irreversible thermodynamics were tested, here in part II, the influence of the presumably most important cytosolic factors was investigated using two glycolytic reactions (i.e., the phosphoglucose isomerase reaction (PGI) with a uni-uni-mechanism and the enolase reaction with an uni-bi-mechanism) as examples. Crowding by macromolecules was simulated using polyethylene glycol (PEG) and bovine serum albumin (BSA). The reactions were monitored calorimetrically and the equilibrium concentrations were evaluated using the equation of state ePC-SAFT. The pH and the crowding agents had the greatest influence on the reaction enthalpy change. Two kinetic models based on irreversible thermodynamics (i.e., single parameter flux-force and two-parameter Noor model) were applied to investigate the influence of cytosolic conditions. The flux-force model describes the influence of cytosolic conditions on reaction kinetics best. Concentrations of magnesium ions and crowding agents had the greatest influence, while temperature and pH-value had a medium influence on the kinetic parameters. With this contribution, we show that the interplay of thermodynamic modeling and calorimetric process monitoring allows a fast and reliable quantification of the influence of cytosolic conditions on kinetic and thermodynamic parameters.

Managing crowd density has become an immense challenge for public authorities due to population growth and evolving human dynamics. Crowd counting estimates the number of individuals in a given area or scene, making it a practical technique applicable in real-world scenarios such as surveillance and traffic control. It contributes to urban planning, retail analytics, and security systems by providing insights into population dynamics and aiding in anomaly detection. This thesis focuses on implementing and evaluating a selective kernel mechanism in crowd counting. The selective kernel block, introduced in a computer vision research known as the Selective Kernel (SK) Network [1], presents an adapted convolution layer as a substitute for the traditional convolution neural network (CNN) architecture. This adaptation has the potential to enhance object detection and image regression tasks. Building upon the C3 framework [2], the thesis applies the selective kernel mechanism to three state-of-the-art crowd counting designs: ResNet [3], CSRNet [4], and SANet [5], resulting in the creation of SK adaptive models. The evaluation process mainly involves collecting and comparing Mean Absolute Error (MAE) and Mean Squared Error (MSE), as well as crowd statistics and crowd density maps. These evaluations are performed using the ShanghaiTech crowd Part A (random high-density crowd images from the website) and Part B (street views in similar scenes) datasets [6]. In 6 comparisons with two different datasets, SK adaptive models were found to have better prediction results in 4 of them against the original models. In conclusion, the SK block offers several advantages: firstly, it enhances feature extraction performance, especially when pretrained with large datasets; secondly, it improves image regression in more straightforward dataset scenarios. On the downside, its impact is limited or detrimental in sparse datasets. This finding suggests that the selective kernel approach holds promise in supporting and improving crowd counting in the high-density group and street view scenarios, facilitating effective public management. / Att hantera folktäthet har blivit en enorm utmaning för offentliga myndigheter på grund av befolkningsökning och förändrade mänskliga dynamiker. Folkräkning uppskattar antalet individer i ett givet område eller scen, vilket gör det till en praktisk teknik som kan tillämpas i verkliga scenarier som övervakning och trafikstyrning. Genom att erbjuda insikter i befolkningsdynamik och hjälpa till med avvikelsedetektering bidrar folkräkning till stadsplanering, detaljhandelsanalys och säkerhetssystem. Denna avhandling fokuserar på implementeringen och utvärderingen av den selektiva kernelmekanismen inom folksamlingars räkning. Den selektiva kernelblocket, introducerat i en datorseendeforskning känd som Selective Kernel Network [1], presenterar en anpassad faltningsskikt som en ersättning för den traditionella konvolutionsneuralnätverk-arkitekturen. Denna anpassning har potential att förbättra objektdetektion och bildregression. Byggande på C3 - ramverket [2] tillämpar avhandlingen den selektiva kernelmekanismen på tre toppmoderna modeller inom folksamlingars räkning: ResNet [3], CSRNet [4], och SANet [5], vilket resulterar i skapandet av SK-adaptiva modeller. Evalueringen innefattar främst insamling och jämförelse av medelabsolutfel och medelkvadratfel, samt statistik om folksamlingar och densitetskartor. Dessa utvärderingar utförs med hjälp av dataseten ShanghaiTech crowd Part A (slumpmässiga bilder av hög densitet från webbplatsen) och Part B (gatuvyer i liknande scenarier) [6]. Totalt genomförs sex jämförelser med två olika dataset, och SK-adaptiva modeller visar bättre prognosresultat i fyra av dem jämfört med de ursprungliga modellerna. Sammanfattningsvis erbjuder SK-blocket flera fördelar: för det första förbättrar det prestandan för funktionsextrahering, särskilt när det förtränas med stora dataset; för det andra förbättrar det bildregression i enklare dataset-scenarier. Å andra sidan är dess påverkan begränsad eller till och med skadlig i glesa dataset. Generellt sett tyder detta på att den selektiva kärnan har lovande att stödja och förbättra publikräkningen i scenarierna med hög täthet och gatuvy, och därigenom underlätta effektiv offentlig förvaltning.