It is a commonly held belief that a repeat caesarean section through a low vertical scar provides easier access and fewer complications than an operation through a previous Pfannenstiel incision. To test this hypothesis the records of one hundred and twenty one repeat caesarean sections were retrospectively reviewed by the author. These records were reviewed at the two large teaching hospitals of the University of the Witwatersrand, Chris Hani Baragwanath and Johannesburg General Hospital. Statistically significant findings were that older women were more likely to have had an initial midline incision. Incision to delivery times were faster via the midline (4 min) than the Pfannenstiel incision (5.5 min). Total operating times did not differ significantly. The findings do show that repeat midline incisions are faster (1.5 min) to deliver, but do not address the patient’s need for a cosmetically pleasing wound scar.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.

No description available.

Background Endoscopic ultrasound-guided fine-needle aspiration and biopsy (EUS-FNA/FNB) has been traditionally used for making a tissue diagnosis. Several newer techniques are emerging as a viable alternative to EUS-FNA/FNB, including mucosal incision-assisted biopsy (MIAB), with a view to increasing the diagnostic yield for upper gastrointestinal (GI) subepithelial tumors (SETs). We conducted a systematic review and meta-analysis to describe the overall diagnostic yield of MIAB for upper GI SETs. Methods Multiple electronic databases (MEDLINE, EMBASE and Google Scholar) and conference abstracts were comprehensively searched. The primary outcome of our meta-analysis was the overall diagnostic yield of the MIAB. The secondary outcome was to study complications in terms of perforation and clinically significant bleeding. The meta-analysis was performed using a DerSimonian and Laird random-effect model. Results Seven studies were included in the final meta-analysis, reporting a total of 159 patients (male 86, female 73) with a mean age of 58 years. The overall pooled diagnostic yield of MIAB was 89% (95% confidence interval [CI] 82.65-93.51, I2=0.00). Histologically, GI stromal tumor was the reported diagnosis in 38.62% (95%CI 22.29-56.24, I2=77.51%) of tumors, followed by leiomyoma 25% (95%CI 18.02-32.62, I2=4.42%). The overall rate of clinically significant bleeding following the procedure was 5.03% (95%CI 0.36-12.86, I2=57.43%) and no perforations were reported. Conclusions MIAB is a safe and effective technique for the diagnosis of upper GI SETs and can be considered as a viable alternative to EUS-FNA/FNB. MIAB can be performed during routine endoscopy and no advanced equipment is required.

This thesis investigates the use of an operational formal architectural strategy to reinvigorate instances of failing city fabric. By introducing hierarchy and nodal destination elements into the urban grid, the existing field is transformed into a network of catalytic centers. Frame is employed as a permeable mediator between the existing grid and insertion, creating a permeable superblock that is both contextual and stimulating. The Over-the-Rhine district in Cincinnati, Ohio, is one of these failing city fabrics. Directly adjacent to downtown, this once vibrant neighborhood has experienced massive depopulation and deterioration. It’s population has dropped from 45,000 to less than 5,000. Currently, 66% of the buildings in the area are vacant or have been demolished. Over-The-Rhine lies between downtown and the University of Cincinnati. There is potential in creating a growth corridor between these two poles through Over-The-Rhine, stimulating the stagnant grid. A nodal infrastructural transit corridor is inserted between Downtown and the University of Cincinnati. Stops along the corridor act as point insertions in the fabric, forming nodal hierarchy. Incision activates the existing context through connection, deploying both a top down and bottom up approach. It creates a large centralized entity framed by and connected to context. It creates a range of scales, allowing for programmatic variety, an urban characteristic that the enclave lacks. It is strategic in working with the fabric, mediating flows and taking advantage of the porous grid condition. Each incision, in order to successfully attract from both downtown and the university, contains programmatic elements from each pole. This integration creates a complex interaction of program, as well as new partnerships between Downtown and University entities. It is a new approach for both Downtown and the University to address the failing fabric between.

The trends of degradation and aggradation are measured in this study for the Lower Mississippi River. Historical riverbed elevation and stage data from the past hundred years were used from six gages in order to measure changes in riverbed gradation. It was found that using stage data to measure gradation changes is a superior method to using riverbed elevations, due to stage data’s reliability, length of record and daily measurements. Degradation in the Lower Mississippi River was seen during the

At the turn of the century, Kanab Creek incised 30-meters into its alluvium, leaving behind fluvial terraces and thick basin fill sediments exposed along arroyo walls. Research objectives were to determine the timing and causes of past valley-filling and arroyo-cutting episodes along a 20 km-long reach of Kanab Creek in southern Utah. Fluvial deposits were mapped at the 1:12,000 scale and sediments were described and dated using Optically Stimulated Luminescence (OSL) and radiocarbon dating. The Kanab Creek valley can be divided into a narrow, upper terraced reach and a broad lower basin fill reach near Kanab, Utah. The most prominent terrace in the upper reach is Quaternary alluvial terrace 4 (Qat4), followed by Qat3, Qat2/3, and Qat2 map units. These are composed of tabular-bedded, fine-grained sand, silt, and clay layers. The Qat2/3 map unit is a both a fill and fill-cut terrace underlain by Qa4, Qa3, and Qa2 alluvium and is used when the Qat3 fill-cut (fill-strath) terrace can not be differentiated from the Qat2 fill terrace due to their similar geomorphic position. The Qat3 fill-cut terrace upstream correlates to ~8 meters of aggradation downstream. The youngest terrace, Qat1, is a minor terrace, composed of coarse-grained channel facies. More recent channel and floodplain deposits were deposited over the last century following arroyo cutting. OSL and radiocarbon results suggest at least four cycles of fluvial cutting and filling: >6-3.5ka (Qa4), ~3->1ka (Qa3), 0.7-0.12ka (Qa2), and post-1880 AD (Qa1). Correlation to regional climate records suggests major periods of aggradation correlate to regionally cooler and wetter climatic intervals. Periods of arroyo cutting occurred at >6ka, ~3ka, 1-0.7ka, and during historic arroyo cutting (1882-1914 AD), and correlate to regionally warmer, drier intervals. These periods of aggradation and incision are roughly contemporaneous with regional drainages, except for the large aggradation seen in Kanab Creek 6-3.5ka (Qa4). Analysis of terrace longitudinal profiles indicates Qat4 has the lowest concavity suggesting that Qat4 aggraded during a period of greater sediment supply and/or reduced flood regime. Although OSL samples exhibited some degree of incomplete zeroing, calculated ages using a minimum age model are consistent with radiocarbon results.

No description available.

Actuellement, la Loire, voit sa géodynamique de plus en plus détériorée. Le déficit du transport solide provoque un enfoncement du lit mineur sur plusieurs secteurs du bassin Amont. Ceci a pour conséquence une déstabilisation progressive des ouvrages (digues, ponts) et l'érosion ou le colmatage des berges ainsi qu'une baisse du niveau piézométrique des nappes alluviales. Le traitement de ces problèmes passe par une meilleure connaissance des processus d'érosion et d'incision fluviale, le premier laissant place au second une fois que la couche « alluviale » a été totalement emportée, laissant apparaître un affleurement rocheux dans le lit du cours d'eau. Ce phénomène complexe est actuellement constaté en divers endroits de la Loire, dans la plaine du Forez. Nous proposons trois approches pour l'analyser.La première approche est fondée sur la modélisation numérique utilisant les équations de Barré-Saint-Venant, pour l'écoulement, couplées aux équations d'Exner et de Meyer-Peter Müller pour le transport solide. Ce modèle monodimensionnel permet d'obtenir la côte du fond du lit de la rivière et le flux solide au droit de chaque point de calcul.La seconde approche, mécaniste, consiste à déterminer de façon semi-empirique le taux d'incision du substratum marneux à partir de deux variables majeures: la puissance hydraulique totale et le coefficient d'abrasion en un point donné. La puissance hydraulique est calculée à l'aide d'un modèle hydraulique tandis que le nombre d'abrasion est une propriété mécanique de la marne qui est déterminée à partir d'essais en laboratoire. La troisième approche relève de la géochimie. Elle consiste à déterminer les provenances des matériaux contribuant à la recharge latérale des sédiments, à partir de leurs signatures géochimiques. Ceci a fait l'objet d'analyses en laboratoire sur des échantillons prélevés sur l'ensemble du linéaire entre Grangent et Balbigny. Les résultats obtenus montrent que ces approches indépendantes sont complémentaires et permettent une description à la fois qualitative et quantitative de l'enfoncement du lit de la Loire dans le secteur d'étude. / Currently, the Loire river, sees its geodynamic increasingly deteriorated. The deficit of sediment transport causes erosion of the bed on several areas of the basin. This results in a gradual destabilization of structures (dams, bridges), erosion or clogging of banks or a decline in piezometric level alluvial.Treating these problems requires a better understanding of the processes of erosion and river incision, the second succeeding the first, once the alluvial material of the bottom was completely removed, revealing a bed outcrop.This complex phenomenon is currently found in various parts of the Loire river, in the plain of Forez.We propose three approaches for this analysis.The first approach is based on numerical modeling using the equations of Barre-de-Saint-Venant, for flow, coupled with the equations of Exner and Meyer-Peter Müller for sediment transport. This monodimensional model allows the simulation of riverbed changement and sediment discharge, right each calculation point of grid mesh.The second approach is mechanistic and consists of determining the rate of marly bedrock incision by a semi-empirical method by the use of two major variables: the total hydraulic power and an abrasion coefficient. The hydraulic power is calculated using a hydraulic model, while the abrasion coefficient is a mechanical property of the marl which is determined from laboratory tests.The third approach is the geochemistry. It consists in determining the provenance of the materials from tributaries and in the main chanel by analyzing their geochemical signatures. This has been the subject of laboratory tests on samples taken across the linear from Grangent to Balbigny.The results obtained show that these independent approaches are complementary and provide both a qualitative and quantitative description of the incision of the Loire river in the study area.

The Snake River flows across the dynamically uplifting hotspot plume of the Yellowstone region, cuts through the Snake River Range and ultimately enters the lowlying eastern Snake River Plain. Thermal and mantle-dynamic uplift around Yellowstone has been recorded by short-term geodesy and modeled by geophysicists, but measurements over Quaternary timescales and an understanding of how that uplift influences regional incision are absent. The Snake River is the only regional river that crosses the uplifting Yellowstone Plateau and flows into the subsiding eastern Snake River Plain (SRP), and provides an opportunity to investigate both ends of the phenomenon on the tailing margin of the Yellowstone region. This thesis consists of two related studies conducted in Alpine Canyon of the Snake River. The first is a study of fluvial terraces and steepness patterns along the Snake River considering the spatial distribution of bedrock or varying hardness and resistance to erosion and in the context of regional tectonics. This study uses surficial mapping, optically stimulated luminescence (OSL) dating, bedrock strength measurements, and steepness analyses of the mainstem Snake River and tributary drainages. Results include the first incision rate estimates for the southwestern part of the Yellowstone hotspot region and a discussion of the possible sources of baselevel fall along the Snake River. The second study documents the transitions between bedrock and alluvial channels in the study area and evaluates morphometric and transport capacity thresholds between these reaches. Alluvial bed-cover mapping with a side-scan sonar along with channel morphometric data, clast-counts, and sediment transport estimates allow us to explore what controls these two fundamental channel types. Results confirm that the Snake River has relatively fast incision rates for the interior western U.S. and that the Snake River is adjusting to an actively deforming landscape. Additionally, our dataset provides field documentation of the magnitude of bedrock-alluvial transitions and may be valuable for parameterizing landscape evolution models or assisting in the restoration of reaches that are in disequilibrium due to changes in land use or climate. This study will hopefully inspire future studies of tectonism and landscape evolution of the Yellowstone hotspot region.