Ten reinforced-concrete continuous deep beams with openings were tested to failure. The main variables investigated were the shear span-to-overall depth ratio, and the size and location of openings. Two failure modes influenced by the size and location of web openings regardless of the shear span-to-overall depth ratio were observed. The normalised load capacity of beams having a web opening area ratio of 0.025 within exterior shear spans was approximately similar to that of their companion solid beams. Continuous deep beams having web openings within interior shear spans exhibited a higher load capacity reduction with the increase of the opening size, similar to simply supported deep beams with web openings. Formulae based on the upper bound analysis of the plasticity theory were proposed to predict the load capacity of continuous deep beams with web openings. Comparisons between the measured and predicted load capacities showed a good agreement.

Η παρούσα εργασία μελετά τα θερμικά ανοίγματα της διπλής έλικας του βιοπολυμερούς DNA χρησιμοποιώντας προσομοιώσεις Monte Carlo σε θερμοκρασία 310 K. Οι υπολογισμοί βασίζονται στο φαινομενολογικό μοντέλο των Peyrand, Bishop και Dauxois καθώς και στον αλγόριθμο των Metropolis et al. Το πρώτο κεφάλαιο της εργασίας αφιερώνεται σε γενικές πληροφορίες γύρω από την δομή και τις λειτουργίες του γεννετικού υλικού. Επιπλέον περιέχει πληροφορίες γύρω από την μεταγραφή του DNA στα προκαρυωτικά κύτταρα. Επειδή σκοπός της εργασίας είναι η διερεύνηση της συσχέτισης μεταξύ μεγάλων θερμικών ανοιγμάτων και θέσεων του βακτηριακού DNA που εμφανίζουν βιολογική λειτουργία (σημεία πρόσδεσης της RNA-πολυμεράσης και διαφόρων βοηθητικών μεταγραφικών παραγόντων) σε διάφορους υποκινητές οπερονίων του βακτηρίου της E.coli, γίνεται μια πιο λεπτομερής συζήτηση για τον τρόπο με τον οποίο τα οπερόνια αυτά επιτυγχάνουν τον έλεγχο της εκφρασής τους. Το δεύτερο κεφάλαιο αναφέρεται στο θεωρητικό υπόβαθρο της εργασίας. Γίνεται μια εκτεταμένη συζήτηση γύρω από τις προσομοιώσεις Monte Carlo και πιο συγκεκριμένα του κριτηρίου των Metropolis et al. Στο ίδιο κεφάλαιο γίνεται παρουσίαση του μοντέλου των Peyrand, Bishop και Dauxois. Στο μοντέλο αυτό η δυναμική ενέργεια του συστήματος αποτελείται από δυο όρους. Ο ένας αναφέρεται στην αλληλεπίδραση μεταξύ των βάσεων ενός ζεύγους βάσης, ενώ ο άλλος στην αλληλεπίδραση μεταξύ των γειτονικών ζευγών βάσεων εξαιτίας της επικάλυψης των π μοριακών τροχιακών κάθε ζεύγους. Το μοντέλο επικεντρώνεται στον πιο προφανή βαθμό ελευθερίας του συστήματος: τη θερμικά ευαίσθητη (εξαιτίας των δεσμών υδρογόνου) απομάκρυνση μεταξύ των βάσεων ενός ζεύγους βάσης. Το τρίτο κεφάλαιο συγκροτείται από τα αποτελέσματα των υπολογισμών και τον σχολιασμό τους. Αρχικά παρουσιάζονται αποτελέσματα για απλούστερα συστήματα ταλαντωτών που αποτελούν οριακές περιπτώσεις του μοντέλου που περιγράφει το πρόβλημα των ανοιγμάτων της διπλής έλικας του DNA, όπως τα συστήματα των μονοδιάστατων ασύνδετων και συνδεδεμένων αρμονικών ταλαντωτών και το μονοδιάστατο σύστημα ανεξάρτητων ταλαντωτών Morse. Ακόμη παρουσιάζονται αποτελέσματα προσομοιώσεων σε τυχαίες αλληλουχίες DNA που δεν σχετίζονται με κανέναν υποκινητή. Το κύριο μέρος του κεφαλαίου αυτού αφιερώνεται στην παράθεση και στον σχολιασμό των αποτελεσμάτων των προσομοιώσεων για τους υποκινητές των τεσσάρων οπερονίων του βακτηρίου E.coli που εξετάστηκαν: της λακτόζης, της τρυπτοφάνης, της γαλακτόζης και της πρωτείνης recA. Επίσης εξετάζονται και οι υποκινητές των γονιδίων AdMLP και AAV P5 αδενοιών. Στο τελευταίο κεφάλαιο της εργασίας αυτής παρουσιάζονται τα συμπεράσματα που εξήχθησαν. / This essay concentrates on studying thermal openings of biopolymer DNA using Monte Carlo simulations based on a microscopic model proposed by Peyrand, Bishop and Dauxois. The fist part of this work includes a brief discussion about the structure of the double helix of DNA and it’s main functions. Moreover in the same part of the assay the transcription regulation of the operons that are studied in our calculations is discussed. The used Peyrand, Bishop, and Dauxois model takes into account only the transverse stretching of the hydrogen bonds connecting complementary bases of the double stranded DNA. The potential energy of the model includes the potential energy between complementary bases and the stacking interactions between successive base-pairs. The Metropolis algorithm is used to produce equilibrium configurations of the double strand at temperature of 310 K. The Peyrand, Bishop and Dauxois model and the Metropolis method are described in the second chapter of this thesis. After equilibration, several other realizations (with numerous Monte Carlo steps, based on the Metropolis algorithm) are performed in order to measure the local probabilities for large openings and compare them with functional positions in specific promoter segments of biological interest (e.g. transcription starting sites, binding sites for regulatory proteins). The main goal of this project is to investigate several bacterial DNA gene promoter segments and to examine whether large openings occur with higher probability at biological functional sites. In particular we have examined the following operons: lac, tryptophane, gal, recA and the viral promoters AdMPL and AAV P5. Our results are compared with the binding sites of the RNA-polymerase and the regulatory proteins of each promoter. In addition, the results for the viral promoters have been compared with other theoretical results and experimental data. The presentation of our results takes place in the third chapter of the dissertation. Apart from the results that refer to the E.coli operons and the viral promoters, we also present calculations in simpler systems such as one dimensional chains of harmonic or Morse oscillators. Finally in the fourth chapter we present our conclusions.

The type of regional dynamics of a species can provide information on how to manage the species, and may be the only way that some rare species may persist in a given region. A metapopulation is a type of regional dynamic in which local extinction is counterbalanced by recruitment from nearby patches. Metapopulation studies were originally conducted on animals, but have been adapted to plants, and are generally restricted to single-season studies. Plant species may persist as a metapopulation in patchy habitats, such as in forest openings. Forest openings (commonly called barrens, hill prairies, or glades) are habitats found on ridgetops which are characterized by having thin or nutrient-poor soil, high sunlight exposure, and relatively low soil moisture when compared to nearby forest habitats. Forest openings commonly contain plant species more frequently found in prairies, and are often maintained by natural fires that prevents woody species encroachment. In the absence of natural fires due to human management and suppression, woody species have invaded some forest openings, dividing them into a series of patches. To determine whether it is possible for each species to persist as a metapopulation in forest openings, five studies were carried out at each of three sites within the Shawnee National Forest in southern Illinois: a plant survey and ordination using environmental variables, the use of incidence function models to determine which of the species had the potential to form a metapopulation, a metacommunity study to examine overall patterns at each site, a seed bank study, and a seed dispersal study. Forest openings were found to be separate habitats from the surrounding forest based upon canopy openness. Approximately 30% of the species fit the metapopulation model, and the metacommunities at each of the sites exhibited a Clementsian pattern, characterized by groups of co-occurring species that replace each other over the region due to turnover between the groups of species. Species that fit the metapopulation model tended to have seeds that emerge more frequently from the seed bank if annuals and less frequently in the seed bank than species not fitting the metapopulation model (non-metapopulation species) if longer-lived. Species fitting the metapopulation model dispersed equal numbers of seeds as non-metapopulation species at short (5m) and medium (10m) distances, and in some cases dispersed more seeds to longer distances than non-metapopulation species. These studies show that forest openings can be treated as islands of suitable habitat for some species, and that numerous (~30%) species (such as Scleria pauciflora, Stylosanthes biflora, and Manfreda virginica) may assume a metapopulation dynamic in any given year. Many species may have incidence patterns consistent with those of a metapopulation in multiple years; however, the exact habitat patches in which species occur in any given year may change from year to year. Species in forest openings tend to co-occur in groups (a Clementsian pattern), which means that management plans should consider the entire community rather than a single species.

During European settlement, the vast majority of grasslands in Illinois were converted for agricultural purposes. Some of the remaining natural areas in southern Illinois include natural xeric forest openings (i.e., barrens, glades, outcrops), that have transitional community compositions representative of previously extensive grasslands and adjacent hardwood forests. Previous research in these forest openings show that the communities are largely driven by edaphic conditions and vary spatially across southern Illinois. While most of these communities are currently protected and established as nature preserves, threats to these natural xeric forest openings continue to persist, such as climate change and exotic invasion. These threats are capable of altering taxonomic, phylogenetic, and functional diversity and community composition. The overall goals of this research were to 1) determine metapopulations and metacommunity structure in a local group of sandstone outcrop communities (a subset of natural xeric forest opening communities), 2) expand resolution to a regional scale to include natural xeric forest openings with several substrates to investigate changes in taxonomic, phylogenetic, and functional diversity and community composition since surveys conducted in 1988, and 3) include spatial analyses to characterize autocorrelation structure of diversity and environmental variables and biological turnover of natural xeric forest openings at a global scale. Sandstone outcrop communities at Jackson Hollow in Pope County, Illinois had several metapopulation species based on Hanski’s incidence functional model. These metapopulation species were more often members of the Asteraceae and Poaceae than members of other plant families, and were often exotic in origin with short-lived lifecycles. These metapopulation species were also neither dominant species or singletons within sandstone patches. Based on the Elements of Metacommunity (EMS) Framework, positive coherence, species turnover, and boundary clumping indicate that these sandstone outcrop communities are predictable communities where species replace one each other regularly as groups of species and respond similarly to environmental gradients. Furthermore, diversity metrics were all positively correlated with each other, but not with patch characteristics. In addition, total species and metapopulation species were positively associated with phylogenetic and functional diversity, but metapopulation species were positively associated with non-standardized phylogenetic and functional indices. When looking at several natural xeric forest openings across southern Illinois and comparing them based on substrate types and between surveys in 1988 and 2019, taxonomic, phylogenetic, and functional compositions were distinct based on substrates, but were stable and resilient across surveys. Sandstone and shale communities were the most similar based on composition, followed by limestone communities compared to sandstone and shale communities, and then loess communities being the most dissimilar from all other communities. Environmental variables that best explained differences in community composition were canopy cover, soil acidity, photosynthetically active radiation, and soil depth. Diversity variables that best explained differences in community composition were phylogenetic nearest taxon index, Faith’s phylogenetic diversity, and dominant species richness. Ninety-four different species were either significant indicators for specific substrates, or 2019 surveys. While no cases of phylogenetic signal were observed based on functional traits, substrate types, or surveys, three cases of functional signal based on dominant communities were observed in sandstone communities in 2019, shale communities in 2019, and overall shale communities across 1988 and 2019 surveys. When applying spatial analyses to these natural xeric forest openings to understand autocorrelation structure and biological turnover, soil depth was the only environmental variable that exhibited significant spatial autocorrelation, as previous glacial events caused loess hill prairies in the northwestern extent of this study to have deeper soil due to Quaternary loess deposition. However, several diversity metrics exhibited spatial structure based on 1988 and 2019 surveys (1988: dominant species richness, Pielou’s evenness, Shannon-Weiner diversity, Faith’s phylogenetic diversity, and distance-based functional diversity; 2019: dominant species richness, Pielou’s evenness, Shannon-Weiner diversity, Faith’s phylogenetic diversity, and phylogenetic nearest taxon index). In addition, climate variables daily mean temperature and total annual precipitation exhibited spatial structure. Most variables were spatially clustered at local site scales and spatially dispersed at larger scales and spatially over-dispersed at a regional scale. Generalized dissimilarity models constructed based on elevation, soil, and climate variables showed that models based on both functional composition and 2019 surveys best explained biological turnover compared to taxonomic and phylogenetic and 1988 models. Several variables included in models differed based on aspects of biological turnover or surveys, but temperature annual range and soil bulk density variables were common across all models. However, differences between total deviance explained and null deviances show that geographic distance between natural xeric forest openings was overwhelmingly the most influential variable contributing to biological turnover. Given these observations, natural xeric forest openings at local scales persist as distinct habitat patches amidst a landscape that largely constitutes an inhospitable matrix to colonizing species, yet certain species are able to migrate between patches. The resulting community assembly of individual patches is determined by both colonizing species and environmental gradients across the landscape. Despite simultaneous threats to diversity and composition in natural xeric forest openings at a regional scale, substrate continues to drive community assembly, in that certain species are characteristic indicators of these substrates. Furthermore, the most recent surveys in sandstone and shale communities exhibited functional signals. However, these natural xeric forest openings are spatially structured based on soil depth due to glacial history, certain metrics of diversity, and climate variables. Along with these occurrences of spatial autocorrelations, different aspects of biological turnover are best predicated by geographic distance as well as unique combinations of climate and soil variables between different aspects of diversity and surveys.

In this work agricultural workwear garments will be deconstructed with the goal of challenging agricultural workwear expression and creating clothes that can be worn in multiple ways allowing for wider expression and ways of wearing in a smaller set of clothes. By opening up clothes from a farmer’s wardrobe to new ways of wearing and new garment types, placing them in new contexts, stereotypes and preconceived notions of farmers and rural culture will be challenged. The method used to deconstruct the garments will be based on working with ready made clothes and replicas and cutting them up, displacing the garments parts by allowing the wearer to enter the garment in new ways through alternative openings inspired by the unconventional zipper openings found on many vintage space- suits. Then making necessary adjustments to the construction to best allow the garment to allow for multiple ways of wearing. Colors and textures will be challenged as-well drawing inspiration from space suits and space travel. The relevance of the work is both personal and emotive through its reference points in agricultural workwear and space travel. Traditional shapes found in workwear will be challenged, trying to find new shape and silhouette with the application of deconstructionist methodology from Martin Margiela. The work also holds relevance from a sustainable perspective by prolonging the lifecycle of garments and discourage overconsumption with garments that fill up a wider purpose that otherwise would be served by multiple garments.

Yes / For composite cellular beams, additional deflections occur due to the loss of bending and shear stiffness at the opening positions and also due to slip in the shear connectors caused by partial shear connection. Design formulae are presented for the additional deflection of composite beams with circular openings or for cellular beams as a function of the proportionate depth of the openings. The simplified formulae are calibrated against finite element results for both cellular and solid web beams and also against measured deflections of a 15.3 m composite cellular beam test. This additional deflection is presented as a function of flexural and shear terms that are a function of the span:depth ratio. For modelling of cellular beams to determine deflections, the circular opening may be represented by an equivalent rectangular opening of length equal to 70% of the opening diameter.

In 1982, several rectangular openings were cut in a 100 year old sub-alpine Norway spruce forest stand to initiate regeneration at the Lusiwald site at Davos, Switzerland. The openings on the steep, north-facing slope created rapid changes to the environment of the border trees. Growth reactions of these border trees were compared and analysed with reference trees from the adjacent closed canopy stand in 1997. The radial growth pattern of the two data sets differed within the 14-year period since the openings were cut; the border trees showed growth releases. The growth reaction at the stem base was larger than at breast height. Changes in wind exposure may have influenced border trees to adapt their root systems. Sub-alpine Norway spruce stands aged around 100 years, which are usually considered slow-growing on a north aspect, still seem capable of reacting to greater resource availability such as sudden light changes.

Soft-sediment ecosystems can be degraded through anthropogenic development, leading to reduced habitat suitability for biological communities. On the North Coast of British Columbia, Canada, intensive industrial activity and coastal development has occurred, specifically around the Skeena and Kitimat River Estuaries. In addition to current development, both regions have the potential for further development, while also undergoing passive restoration from historical disturbances. Therefore, I aimed to broaden our understanding of passive restoration and non-invasive monitoring of intertidal soft-sediment ecosystems, by carrying out experiments at mudflats in both estuaries during the summer of 2017. Specifically, I aimed to expand the use of a non-invasive population assessment technique to novel species in soft-sediment ecosystems. Relationships between burrowing decapod abundance and burrow openings have been successfully used to estimate population sizes, but this technique has yet to be applied to large burrowing polychaetes, bivalves, or in regions of high macrofaunal diversity. As such, I assessed mudflats in regions of low (n = 1 species) and high (n = 8 species) biodiversity to determine if macrofauna abundances could be estimated from burrow openings on the sediment surface. Where only one burrowing bivalve species was present, a relationship between burrow openings and population abundance was not feasible, but burrow openings were useful in estimating total macrofaunal community abundance at a high diversity mudflat. This suggests that monitoring through burrow opening counts has the ability to detect overall changes in population abundance. Next, I examined the infaunal community, sediment conditions, and nutrient availability at one intertidal mudflat in the Skeena River Estuary following the cessation of heavy industrial activities (i.e. a salmon cannery and pulp mill) to determine the capacity for passive restoration. Sediment conditions varied spatiotemporally, and nutrient availability showed temporal variation but trends were difficult to relate to historical or current potential disturbances. The legacy of past development is still apparent on the infaunal community in the form of patchy distributions of disturbance-indicating taxa, but the mudflat appears to be in an overall healthy state with a diverse and functioning food web, indicating community recovery from historical activities. Results from these studies indicate passive restoration can be appropriate for estuarine soft-sediment ecosystems, while monitoring population abundance through burrow openings could be a method of detecting disturbances or tracking recovery of macrofaunal populations. / Graduate / 2020-06-28

Bakgrund: Flera studier beskriver vikten av att minimera dörröppningsfrekvensen på operationssalarna. Högre frekvens av dörröppningar leder till försämrad ventilation på operationssalen, vilket i sin tur kan leda till vårdrelaterade infektioner. Syfte: Syftet med denna studie var att på en operationsavdelning observera frekvensen av dörröppningar under pågående operation, varför och av vem de öppnades. Metod: Metoden var en kvantitativ deskriptiv observationsstudie med tvärsnittsdesign. Personalen på en operationsavdelning i Mellansverige observerades under pågående operationer. Observationerna utfördes sex vardagar i januari 2013 och valdes från operationsprogrammet. Resultat och slutsats: 22 observationstillfällen observerades, 11 från vardera konventionell respektive infektionskänslig kirurgi. Studien visade att dörröppningsfrekvensen var högre vid konventionell kirurgi jämfört med infektionskänslig. Dörröppningsfrekvensen varierade från en gång per minut till var 10:e minut vid konventionell kirurgi. Vid infektionskänslig kirurgi varierade dörröppningsfrekvensen från var 3:e minut till var 19:e minut. Den yrkesgrupp som utförde de flesta dörröppningarna var den cirkulerande personalen. Den största anledningen till dörröppningarna var hämtning av utrustning/material/instrument. Klinisk betydelse: Studien visar att dörröppningsfrekvensen vid konventionell kirurgi är högre än vid infektionskänslig kirurgi. För infektionskänslig kirurgi finns lokala riktlinjer. Däremot finns det inte vid konventionell kirurgi, där de kunde ha betydelse för att sänka dörröppningsfrekvensen. / Background: Several studies describe the importance of minimizing the frequency of door openings to the operating room. Higher frequency of door openings leads to impaired ventilation in the operating room, which in turn can lead to surgical site infections. Aim: The aim of this study was that in a surgical department observing the frequency of door openings during surgery, why and by whom they were opened. Method: The method was a quantitative descriptive observational study with cross-sectional design. The personnel in a surgical department in central Sweden were observed during operations. The observations were performed six weekdays in January 2013 and were selected from the surgical program. Results and conclusion: 22 observations were observed, 11 each from conventional and implant surgery. The study indicated that door openings were more frequent when comparing conventional surgery with implant surgery. The frequency of door openings varied from once per minute to every 10 minutes for conventional surgery. In implant surgery the frequency of door openings varied from every 3 minutes to every 19 minutes. The profession who carried out most door openings was the circulating staff. The main reason for the door openings was retrieval of equipment / materials / instruments. Clinical relevance: This study shows that the frequency of door openings was higher at conventional surgery than at implant surgery. For implant surgery there are local guidelines. However, there are none for conventional surgery, where they could play a role in lowering the frequencies of door openings.

Thesis (Ph. D.)--Columbia University, 1933. / Vita. Published also without vita.