Brain Complexity: Analysis, Models and Limits of Understanding

Abstract. Manifold initiatives try to utilize the operational principles of organisms and brains to develop alternative, biologically inspired computing paradigms. This paper reviews key features of the standard method applied to complexity in the cognitive and brain sciences, i.e. decompositional analysis. Projects investigating the nature of computations by cortical columns are discussed which exemplify the application of this standard method. New findings are mentioned indicating that the concept of the basic uniformity of the cortex is untenable. The claim is discussed that non-decomposability is not an intrinsic property of complex, integrated systems but is only in our eyes, due to insufficient mathematical techniques. Using Rosen’s modeling relation, the scientific analysis method itself is made a subject of discussion. It is concluded that the fundamental assumption of cognitive science, i.e., cognitive and other complex systems are decomposable, must be abandoned.

Amplification of Australian heatwaves via local land‐atmosphere coupling

Antecedent land surface conditions play a role in the amplification of temperature anomalies experienced during heatwaves by modifying the local partitioning of available energy between sensible and latent heating. Most existing analyses of heatwave amplification from soil moisture anomalies have focused on exceptionally rare events and consider seasonal scale timescales. However, it is not known how much the daily evolution of land surface conditions, both before and during a heatwave, contributes to the intensity and frequency of these extremes. We examine how the daily evolution of land surface conditions preceding a heatwave event contributes to heatwave intensity. We also diagnose why the land surface contribution to Australian heatwaves is not homogeneous due to spatiotemporal variations in land‐atmosphere coupling. We identify two coupling regimes: a land‐driven regime where surface temperatures are sensitive to local variations in sensible heating and an atmosphere‐driven regime where this is not the case. Northern Australia is consistently strongly coupled, where antecedent soil moisture conditions can influence temperature anomalies up to day 4 of a heatwave. For southern Australia, heatwave temperature anomalies are not influenced by antecedent soil moisture conditions due to an atmosphere‐driven coupling regime. Therefore, antecedent land surface conditions have a role in increasing the temperature anomalies experienced during a heatwave only over regions with strong land‐driven coupling. The timescales over which antecedent land surface conditions contribute to Australian heatwaves also vary regionally. Overall, the spatiotemporal variations of land‐atmosphere interactions help determine where and when antecedent land surface conditions contribute to Australian heat extremes

Amplification of Australian Heatwaves via Local Land-Atmosphere Coupling

[eng] Antecedent land surface conditions play a role in the amplification of temperature anomalies experienced during heatwaves by modifying the local partitioning of available energy between sensible and latent heating. Most existing analyses of heatwave amplification from soil moisture anomalies have focused on exceptionally rare events and consider seasonal scale timescales. However, it is not known how much the daily evolution of land surface conditions, both before and during a heatwave, contributes to the intensity and frequency of these extremes. We examine how the daily evolution of land surface conditions preceding a heatwave event contributes to heatwave intensity. We also diagnose why the land surface contribution to Australian heatwaves is not homogeneous due to spatiotemporal variations in land‐atmosphere coupling. We identify two coupling regimes: a land‐driven regime where surface temperatures are sensitive to local variations in sensible heating and an atmosphere‐driven regime where this is not the case. Northern Australia is consistently strongly coupled, where antecedent soil moisture conditions can influence temperature anomalies up to day 4 of a heatwave. For southern Australia, heatwave temperature anomalies are not influenced by antecedent soil moisture conditions due to an atmosphere‐driven coupling regime. Therefore, antecedent land surface conditions have a role in increasing the temperature anomalies experienced during a heatwave only over regions with strong land‐driven coupling. The timescales over which antecedent land surface conditions contribute to Australian heatwaves also vary regionally. Overall, the spatiotemporal variations of land‐atmosphere interactions help determine where and when antecedent land surface conditions contribute to Australian heat extremes

Clinical significance of blood-device interaction in hemodialysis

The syndrome of dialysis-associated leukopenia and complement activation by cellulosic membranes, including the so-called "first use syndrome", is reviewed and the pathophysiology of these phenomena is discussed. Subsequently the clinical side effects of hemodialysis, including dialysis-associated hypoxemia, are discussed. The hypoxemia, according to the authors, is mainly related to the loss of carbon dioxide through the dialyser. A minor role may be played by complement activation causing temporary sequestration of leukocytes in the pulmonary capillaries with (asymptomatic) peripheral leukopenia on the one hand and plugging of the pulmonary capillary bed with transient pulmonary hypertension and hypoxemia on the other. The question of dialysis-associated eosinophilia and ethylene oxide hypersensitivity is addressed as also contributing to the first use syndrome. The effects of interleukin release from monocytes and of contamination of the dialysis fluid are briefly discussed. The rare syndrome of silicone rubber spallation with hepato-and splenomegaly is also mentioned and finally the pathogenesis and symptomatology of the beta 2 microglobulin amyloidosis syndrome in long-term dialysis patients is presented.Journal ArticleReviewinfo:eu-repo/semantics/publishe

Passive Films On Stainless-Steels in Aqueous-Media

The purpose of this paper is to provide a syntheses of experimental results regarding films formed on the surface of stainless steels. Such syntheses are attempted for the environments most studied. In each case the overview is presented with reference to the most important papers. Conflicting data are also presented and discussed. Based on the results of the prior studies, a four region model is proposed to describe the surface passive film and its breakdown