Three-dimensional pattern formation, multiple homogeneous soft modes, and nonlinear dielectric electroconvection

Patterns forming spontaneously in extended, three-dimensional, dissipative systems are likely to excite several homogeneous soft modes ($\approx$ hydrodynamic modes) of the underlying physical system, much more than quasi one- and two-dimensional patterns are. The reason is the lack of damping boundaries. This paper compares two analytic techniques to derive the patten dynamics from hydrodynamics, which are usually equivalent but lead to different results when applied to multiple homogeneous soft modes. Dielectric electroconvection in nematic liquid crystals is introduced as a model for three-dimensional pattern formation. The 3D pattern dynamics including soft modes are derived. For slabs of large but finite thickness the description is reduced further to a two-dimensional one. It is argued that the range of validity of 2D descriptions is limited to a very small region above threshold. The transition from 2D to 3D pattern dynamics is discussed. Experimentally testable predictions for the stable range of ideal patterns and the electric Nusselt numbers are made. For most results analytic approximations in terms of material parameters are given.Comment: 29 pages, 2 figure

Left hepatic lobe herniation through an incisional anterior abdominal wall hernia and right adrenal myelolipoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Herniation of the liver through an anterior abdominal wall hernia defect is rare. To the best of our knowledge, only three cases have been described in the literature.</p> <p>Case presentation</p> <p>A 70-year-old Mexican woman presented with a one-week history of right upper quadrant abdominal pain, nausea, vomiting, and jaundice to our Department of General Surgery. Her medical history included an open cholecystectomy from 20 years earlier and excessive weight. She presented with jaundice, abdominal distension with a midline surgical scar, right upper quadrant tenderness, and a large midline abdominal wall defect with dullness upon percussion and protrusion of a large, tender, and firm mass. The results of laboratory tests were suggestive of cholestasis. Ultrasound revealed choledocholithiasis. A computed tomography scan showed a protrusion of the left hepatic lobe through the anterior abdominal wall defect and a well-defined, soft tissue density lesion in the right adrenal topography. An endoscopic common bile duct stone extraction was unsuccessful. During surgery, the right adrenal tumor was resected first. The hernia was approached through a median supraumbilical incision; the totality of the left lobe was protruding through the abdominal wall defect, and once the lobe was reduced to its normal position, a common bile duct surgical exploration with multiple stone extraction was performed. Finally, the abdominal wall was reconstructed. Histopathology revealed an adrenal myelolipoma. Six months after the operation, our patient remains in good health.</p> <p>Conclusions</p> <p>The case of liver herniation through an incisional anterior abdominal wall hernia in this report represents, to the best of our knowledge, the fourth such case reported in the literature. The rarity of this medical entity makes it almost impossible to specifically describe predisposing risk factors for liver herniation. Obesity, the right adrenal myelolipoma mass effect, and the previous abdominal surgery are likely to have contributed to incisional hernia formation.</p

The backward-bending commute times of married women with household responsibility

The purpose of this paper is to examine theoretically and empirically whether the commute times of married women follow a backward-bending pattern with respect to wage rates. The existing literature has shown that married women tend to choose short commutes because of their relatively low wages combined with comparatively heavy household responsibilities. However, a workleisure model, which includes the simultaneous decision wives take regarding commute times and wage rates, suggests that married women employed in highly paid positions also undertake short commutes, while married women with wage rates in the middle range choose long commutes. These results suggest that the commute times of married women display a backward-bending pattern. Applying an instrumental variable strategy that accounts for the endogeneity of wage rates, the empirical results for employed married women in Japan appear to support this nding. Moreover, one of our results suggests that highly paid married women can still secure greater leisure time with short commutes, despite retaining a heavy load of domestic responsibilities.Working Paper, No.234, 2008.9.1版http://hdl.handle.net/10110/254

Solubilization and Characterization of Phosphoprotein Phosphatase(s) from Bovine Corpus-Luteum Plasma Membranes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65607/1/j.1432-1033.1975.tb02186.x.pd

Influence of experimental set-up and methodology for measurements of metabolic rates and critical swimming speed in Atlantic salmon Salmo salar

In this study, swim‐tunnel respirometry was performed on Atlantic salmon Salmo salar post‐smolts in a 90 l respirometer on individuals and compared with groups or individuals of similar sizes tested in a 1905 l respirometer, to determine if differences between set‐ups and protocols exist. Standard metabolic rate (SMR) derived from the lowest oxygen uptake rate cycles over a 20 h period was statistically similar to SMR derived from back extrapolating to zero swim speed. However, maximum metabolic rate (MMR) estimates varied significantly between swimming at maximum speed, following an exhaustive chase protocol and during confinement stress. Most notably, the mean (±SE) MMR was 511 ± 15 mg O2 kg−1 h−1 in the swim test which was 52% higher compared with 337 ± 9 mg O2 kg−1 in the chase protocol, showing that the latter approach causes a substantial underestimation. Performing group respirometry in the larger swim tunnel provided statistically similar estimates of SMR and MMR as for individual fish tested in the smaller tunnel. While we hypothesised a larger swim section and swimming in groups would improve swimming performance, Ucrit was statistically similar between both set‐ups and statistically similar between swimming alone v. swimming in groups in the larger set‐up, suggesting that this species does not benefit hydrodynamically from swimming in a school in these conditions. Different methods and set‐ups have their own respective limitations and advantages depending on the questions being addressed, the time available, the number of replicates required and if supplementary samplings such as blood or gill tissues are needed. Hence, method choice should be carefully considered when planning experiments and when comparing previous studies.publishedVersio

Structural MRI studies of language function in the undamaged brain

In recent years, the demonstration that structural changes can occur in the human brain beyond those associated with development, ageing and neuropathology has revealed a new approach to studying the neural basis of behaviour. In this review paper, we focus on structural imaging studies of language that have utilised behavioural measures in order to investigate the neural correlates of language skills in the undamaged brain. We report studies that have used two different techniques: voxel-based morphometry of whole brain grey or white matter images and diffusion tensor imaging. At present, there are relatively few structural imaging studies of language. We group them into those that investigated (1) the perception of novel speech sounds, (2) the links between speech sounds and their meaning, (3) speech production, and (4) reading. We highlight the validity of the findings by comparing the results to those from functional imaging studies. Finally, we conclude by summarising the novel contribution of these studies to date and potential directions for future research

Diferenças na infestação de Aphis gossypii em plantas de algodoeiro cultivar 'IAC-RM3' tratadas com reguladores de crescimento

We have studied the effect of application of growth regulators, (2-chloroethyl) trimethylammonium chloride (CCC), N,N-dimethylaminosuccinamic acid (SADH), gibberellic acid (GA3) and 3-indoleacetic acid (IAA) on cotton, Gossypium hirsutum L. cv. 'IAC-RM3', in relation to atack of Aphis gossypii Glover, 1876, under greenhouse conditions. Two determinations of infestation levels of the aphids showed differences in degree of infestation among treatments. CCC treated plants showed increasing in aphid colonization in relation to GA3 at 100 ppm treated plants. The application of SADH at 4000 ppm also showed a tendency of increasing aphid colonization in relation to treated plants with GA3 at 100 ppm. Probably growth retardants promote differences in the water status of hostplant; and the aphids preferences to that plants suggest that the increase in the osmotic potential promotes better rates of aphid feeding than GA3 treated plants. In treated plants with GA3 at 100 ppm the infestation decreased, there was water stress during the warmer time of the day and a probable decreasing in the osmotic potential.Estudou-se a influência da aplicação de reguladores de crescimento (CCC, SADH, GA3 e IAA) em algodoeiro, Gossypium hirsutum L. cv. 'IAC-RM3', na infestação de Aphis gossypii Glover, 1876; em condições de casa de vegetação. A realização de duas determinações no nível de infestação dos afídios, evidenciou que plantas tratadas com CCC mostram níveis superiores de infestação com relação às tratadas com GA3 a 100 ppm; sendo que a aplicação de SADH a 4000 ppm também promoveu uma tendência de maior infestação com relação ao GA3 a 100 ppm. Estes resultados parecem revelar que os retardadores de crescimento promovem um equilíbrio hídrico interno nas plantas mais favorável, mantendo o potencial osmótico mais elevado e possibilitando uma melhor alimentação do afídio. Plantas tratadas com GAg a 100 ppm parecem sofrer maiores déficits hídricos, não favorecendo o estabelecimento das colônias, nas condições estudadas