The effect of wall absorption on the Toms effect

The effect of the adsorption of Polymer Molecules to tube walls on the Toms effect has been investigated, whereby strong and weak adsorbing tube materials for like test distances were used.For Reynold's numbers between 70,000 and 100,000, at a pressure difference of approximately 1 atm, the reduction of pressure drop because of a better adsorption is influenced only insignificantly.Since there were reported much more positive results in a publication by Hand and Williams[1], we try to give an interpretation for this discrepancy.     

Is a theory of direct visual perception adequate?

Contends that theories of direct visual perception which claim that all the information for perception resides in the structure of the ambient optic array are only partial theories. They run counter to evidence in neuropsychology and experimental psychology which suggests that perception may be a process from the inside out as well as from the outside in. It is concluded that the state of the organism at any moment in time, measured by feedback from the CNS itself, determines both what part of the structure of the optic array is relevant at a given moment and how it will be interpreted. (64 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eigenvalues of partitioned matrices "generated" by a matrix with known eigenvalues

A method is shown which allows to compute the eigenvalues of anmn-dimensional square matrixFfrom the eigenvalues of ann-dimensional matrixA, if the m²submatrices ofFare describable by convergent power series ofA. As an illustration, matrices arising in a multivariable feedback control system are considered.     

Prospective study of the 1st 197 endoscopic retrograde cholangio-pancreatographies (ERCP) in Basel (1973-1975)

Cannulation of the papilla has been successful in 144 out of 197 ERCPs. The rate of success increases with the experience of the endoscopist. The intended filling of the pancreatic duct was successful in 87%, of the bile ducts in 64% and of both duct systems in 28%. The correct diagnosis was made in 77% of pancreatic affections, 71% of biliary diseases and in 43% when both duct systems had to be evaluated. 10 ERCP findings disagreed with the final diagnosis, mainly because the distinction between acute and chronic pancreatitis was not correct. The differentiation of chronic pancreatitis from pancreatic carcinoma is not easy and the evaluation of processes localized to the papilla may be difficult. Complications occurred in 6.6%. It is concluded that the ERCP should be limited to regional hospital centers and should be performed only in cases with well defined indications.     

Acute intermittent porphyria with relapsing acute pancreatitis and unconjugated hyperbilirubinemia without overt hemolysis

A 36-year-old woman was admitted to hospital with a first attack of acute intermittent porphyria. At the same time increased serum levels of amylase and lipase as well as an increased amylase clearance to creatinine clearance ratio were observed, permitting the diagnosis of acute pancreatitis. The etiology of the latter could not be determined. In addition, elevation of indirect bilirubin without evidence of hemolysis was observed Gilbert's syndrome was suspected. 40 weeks after the first episode, a second attack of identical abdominal pain was noted, with elevation of pancreatic enzymes in the serum. There is evidence that acute intermittent porphyria and acute relapsing pancreatitis may have some etiological connection in this patient.     

Performance of panel-based criteria to evaluate the appropriateness of colonoscopy: a prospective study

One in every three people on Earth is believed to be infected with Mycobacterium tuberculosis, leading to seven to eight million cases of active tuberculosis (TB) per year and approximately three million deaths annually. this epidemic, like those of most infectious diseases, creates scientific challenges and opportunities as it raises the demand for public health solutions. The currently available weapons for fighting TB are inadequate. The ultimate goal of biomedical TB research is to lessen the public health burden of this disease by developing improved diagnostic, therapeutic, and intervention strategies. Achieving this goal requires a base of knowledge about the biology of M. tuberculosis and related mycobacteria, their interactions with human and animal hosts, and the nature of an effective host-protective immune response. TB researchers are applying this accumulating base of knowledge to developing rapid, easy-to-use diagnostic assays appropriate for low-as well as high-income countries, improving the current complicated therapeutic regimen, identifying potential new drugs to combat multidrug-resistant TB, and creating more effective vaccines.     

A reply to Mace and Pittenger on "Directly perceiving Gibson".

A reply to Mace and Pittenger on "Directly Perceiving Gibson" (see record 2005-09162-001). W. M. Mace and J. B. Pittenger address themselves to a false issue when they argue that J. J. Gibson has both a theory of stimulus structure and a theory of attention. The point of the 1972 article by J. W. Gyr is that these two theories are not as well integrated as they might be or as integrated as Gibson intended them to be. Moreover, a point also stressed by Gyr and overlooked by Mace and Pittenger is that Gibson's findings of stimulus structure are also consistent with theories that are not theories of direct visual perception, and therefore such findings by themselves cannot be used to support Gibson's theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)