In this work we apply the Adomian decomposition method to an orientation aggregation problem modelling the time distribution of filaments. We find analytical solutions under certain specific criteria and programmatically implement the Adomian method to two variants of the orientation aggregation model. We extend the utility of the Adomian decomposition method beyond its original capability to enable it to converge to more than one solution of a nonlinear problem and further to be used as a corrector in path following bifurcation problems.

Diss. Linköping : Linköpings universitet, 2007.

Colorectal cancer is a common disease, representing the third and second most common cause of cancer death in the United States in women and men, respectively. [Ahnen et al.: Mayo Clin Proc 2014;89:216-224; Siegel et al.: CA Cancer J Clin 2016;66:7]. It is estimated that 20% of patients have distant metastatic disease at time of diagnosis [Ahnen et al.: Mayo Clin Proc 2014;89:216-224; Siegel et al.: CA Cancer J Clin 2016;66:7]. The most common metastatic sites include regional lymph nodes, liver, lungs, and peritoneum via lymphatic/hematogenous dissemination as well as contiguous and transperitoneal routes [Ahnen et al.: Mayo Clin Proc 2014;89:216-224; Siegel et al.: CA Cancer J Clin 2016;66:7]. Upon review of the literature, we found that metastatic colon cancer to the scrotum is rare. The following case report proved to be a unique example of this type of metastasis. This rare regional metastasis is theorized to have resulted from a colo-urethro-scrotal fistula that precipitated from the patient's prior traumatic event. (C) 2017 The Author(s) Published by S. Karger AG, Basel

Background and aim: Persistent stress and life events affect the course of ulcerative colitis (UC) by largely unknown mechanisms. Regulation of epithelial permeability to antigens is crucial for the balance between inflammation and immuno-surveillance, and increased intestinal permeability has been shown in patients with ulcerative colitis. Corticotropin releasing hormone (CRH) has been implicated as an important mediator of stress-induced abnormalities in intestinal mucosal function in animal models. Further cholinergic signalling during stress has been reported to increase bowel ion secretion in humans and uptake of HRP in rodents via activation of mast cells. The overall aim of this thesis was to examine the role of CRH-mediated and cholinergic signalling, and their interaction with mast cells and eosinophils, in the regulation of the mucosal barrier function in the normal human colon and in UC. In vivo studies or the use of surgical specimens for such studies have major shortcomings. Therefore a method with endoscopic biopsies in Ussing chambers was established for studies of protein antigen uptake and electrophysiology in human colonic biopsies, and used in subsequent investigations. Materials and methods: In the four studies a total of 91 healthy volunteers, 3 patients with rectal cancer, and 15 UC patients were included. Biopsies from the sigmoid colon were assessed for macromolecular permeability (Horseradish peroxidase (HRP), and 51Cr-EDTA), and electrophysiology during challenge with sodium caprate (C10), CRH or carbachol. Experiments were repeated with CRH receptor antagonists, carbachol receptor antagonists, mast cell stabilizers and nerve conductance blockers in Ussing chambers. The biopsies were examined by electron and light microscopy for endocytosis of HRP, morphological changes and receptor expression. Moreover, the human mast cell line, HMC-1; was used in studying expression of CRH receptors on mast cells. Results: Endoscopic biopsies of human colon were viable in Ussing chambers, and the technique was shown to be a reliable tool for studies of mucosal permeability to HRP. CRH stimulates transcellular uptake of HRP in human colon via CRH receptor subtypes R1 and R2 on subepithelial mast cells. Further, carbachol acts on muscarinic receptors, located on subepithelial eosinophils. Activated muscarinic M2 and M3 receptors on increased numbers of CRHproducing eosinophils in UC, lead to activation of mast cells and increased macromolecular uptake across the colonic mucosa. This signalling cascade is previously unrecognized, and may be involved in the inflammatory process in UC. Conclusions: In conclusion, we have demonstrated a chain of events leading to increased permeability to the protein antigen HRP in biopsies from healthy volunteers and patients with UC. The important steps begin with a cholinergic signal to muscarinic receptors on the CRH containing eosinophils. The next step includes activation of CRH receptors on mast cells leading to degranulation and increased macromolecular uptake across the epithelium. This explanatory model will have implications for understanding of the pathogenesis of UC and future treatment of the disease.

Thesis (Ph.D.)--Boston University / The formation, evolution and eruption of solar active regions is a main theme in solar physics. Ultimately the goal is predicting when, where and how an eruption will occur, which will greatly aid space weather forecasting. Special kinds of S-shaped active regions (sigmoids) facilitate this line of research, since they provide conditions that are easier to disentangle and have a high probability for erupting as flares and/or coronal mass ejections (CME). Several theories have been proposed for the formation, evolution, and eruption of solar active regions. Testing these against detailed models of sigmoidal regions can provide insight into the dominant mechanisms and conditions required for eruption. This thesis explores the behavior of solar sigmoids via both observational and magnetic modeling studies. Data from the most modern space-based solar observatories are utilized in addition to state-of-the-art three-dimensional data-driven magnetic field modeling to gain insight into the physical processes controlling the evolution and eruption of solar sigmoids. We use X-ray observations and the magnetic field models to introduce the reader to the underlying magnetic and plasma structure defining these regions. By means of a large comprehensive observational study we investigate the formation and evolution mechanism. Specifically, we show that flux cancellation is a major mechanism for building the underlying magnetic structure associated with sigmoids, namely magnetic flux ropes. We make use of topological analysis to describe the complicated magnetic field structure of the sigmoids. We show that when data-driven models are used in sync with MHD simulations and observations we can arrive at a consistent picture of the scenario for CME onset, namely the positive feedback between reconnection at a generalized X-line and the torus instability. In addition we show that topological analysis is of great use in analyzing the post-eruption flare- and CME-associated observational features. Such analysis is used to extend the standard 2D flare/CME models to 3D and to find potentially large implications of topology to understanding 3D reconnection and the seed populations of energetic particles in CMEs.

Background and Aims Colorectal cancer is the third most common type of cancer in Sweden, male and female, with 6500 (4500 colonic/2000 rectal) new cases each year. Surgery remains the treatment of choice. Previous studies show that laparoscopic procedure may lead to fewer complications, shorter postoperative stays and a lesser inflammatory response compared to open procedure. The study examines whether laparoscopic surgery of sigmoid cancer differs from open surgery, regarding inflammatory response through analysis of routine measurements. It also investigates differences in peri- and postoperative quality data from Swedish Colorectal Cancer Registry. Material and Methods 307 consecutive patients underwent surgical sigmoidectomy from February 2007- February 2017, from which elective patients with sigmoid cancer were included. Pre-and postoperative CRP and postoperative WBC, Haemoglobin and Creatinine were collected from medical records at the Department of Surgery, Örebro University hospital. Patient related and perioperative variables were collected from SCRCR (e.g. postoperative stay, bleeding, complications). Results 158 patients fulfilled the inclusion criteria. There was a marked increase in CRP postoperative in both laparoscopic (89) and open (69) groups, but no significant difference comparing the groups. There was a significant difference in perioperative bleeding (p<0.05) and length of stay (p<0.05). Conclusion Sigmoidectomy, laparoscopic or open, cause an increase in CRP. No significant difference in inflammatory response was noted between the groups. Patients undergoing laparoscopic, compared to open sigmoidectomy has: less perioperative bleeding, shorter postoperative stay and a longer duration of surgery, like previous studies.

INTRODUCTION Internal abdominal hernias are infrequent but an increasing cause of bowel obstruction still often underdiagnosed. Among adults its usual causes are congenital anomalies of intestinal rotation, postsurgical iatrogenic, trauma or infection diseases. PRESENTATION OF CASE We report the case of a 63-year-old woman with history of chronic constipation. The patient was hospitalized for two days with acute abdominal pain, abdominal distension and inability to eliminate flatus. The X-ray and abdominal computerized tomography scan (CT scan) showed signs of intestinal obstruction. Exploratory laparotomy performed revealed a trans-mesenteric hernia containing part of the transverse colon. The intestine was viable and resection was not necessary. Only the hernia was repaired. DISCUSSION Internal trans-mesenteric hernia constitutes a rare type of internal abdominal hernia, corresponding from 0.2 to 0.9% of bowel obstructions. This type carries a high risk of strangulation and even small hernias can be fatal. This complication is specially related to trans-mesenteric hernias as it tends to volvulize. Unfortunately, the clinical diagnosis is rather difficult. CONCLUSION Trans-mesenteric internal abdominal hernia may be asymptomatic for many years because of its nonspecific symptoms. The role of imaging test is relevant but still does not avoid the necessity of exploratory surgery when clinical features are uncertain. / Revisión por pares

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18317号 / 農博第2042号 / 新制||農||1021(附属図書館) / 学位論文||H26||N4824(農学部図書室) / 31175 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 平井 伸博, 教授 今井 裕, 准教授 三宅 武 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

A complex bio-mechanism, referred to as calcium homeostasis, regulates plasma ionized calcium (Ca++) concentration in the human body to within a narrow physiologic range which is crucial for maintaining normal physiology and metabolism. Various metabolic disorders and pathologic conditions originate from acute and/or chronic disturbances/disorders in calcium homeostatic system. This system relies on numerous sub-systems which operate in different time-scales ranging from minutes to weeks. In this thesis we focus on a particular sub-system that operates on the time-scale of minutes; the dynamics involves the response of the parathyroid glands to acute changes in plasma Ca++ concentration. We develop a two-pool, linear time-varying model describing the dynamics of the sub-system. We show that this model can predict dynamics observed in clinical tests of induced hypo- and hyper-calcemia in normal humans. In addition, we develop a new protocol for the construction of a Ca-PTH reverse sigmoid curve based on the mathematical model. This protocol removes deficiencies in current protocols in that the resulting curve is invariant with respect to the subject's axis dynamics and calcium clamp test dynamics.

The primary objective of this research is to associate lumbar segmental mechanical response with intervertebral disc degeneration under physiologic testing conditions. Because no mathematical model exists for lumbar spine segmental rotations, a portion of this thesis evaluates potential methods for curve fitting the torque-rotation curves. The Dual Inflection Point (DIP) Boltzmann equation was developed during the course of this research and is presented here as a method for fitting spinal motion data wherein a physical meaning can be assigned to each of the model coefficients. This model can tell us more about the effects of degeneration, testing conditions, and other factors that are expressed in the change in spinal motion. Previous studies have investigated the relationship between the degeneration grade and flexibility of the intervertebral disc, but were completed without the presence of a compressive follower load. This study builds on past work by performing the testing under a compressive follower load. Segmental stiffness, range of motion (ROM), hysteresis area, and normalized hysteresis (hysteresis area/ROM) were evaluated and the effect of degeneration, segment level, temperature, and follower load were analyzed. Twenty-one functional spinal units (FSUs) were tested in the three primary modes of loading at both body temperature and room temperature in a near 100% humidity environment. A compressive follower load of 440 N was applied to simulate physiologic conditions. Fifteen of the twenty-one segments were also tested without the follower load to determine the effects of the load on segmental biomechanics. The grade of degeneration for each segment was determined using the Thompson scale and the torque-rotation curves were fit with the DIP-Boltzmann sigmoid curve.The effect of degeneration was statistically significant (α = 0.05) for stiffness, ROM, and hysteresis area in axial rotation (AR) and lateral bending (LB); it was also statistically significant for ROM and normalized hystersis in flexion-extension (FE). The lumbosacral joint (L5-S1) was significantly stiffer in AR and LB; the decrease in ROM and hysteresis area in AR and LB were also statistically significant for the lumbosacral joint compared to L1-L2 and L3-L4. Temperature had a significant effect on stiffness and hysteresis area in AR and on hysteresis area in LB. The follower load increased stiffness in all three modes of loading, but was significant only in AR and LB; it also reduced ROM and increased normalized hysteresis in all three modes of loading.