Selection of subjects in studies of schizophrenic cognition.

Considers that an investigator's method of selection of schizophrenics and control Ss for research on schizophrenic cognition determines whether groups differ either on accuracy or on any specific error that is highly correlated with accuracy. Severity of disturbance and chronicity are especially important determinants of results. If matching on correlated demographic variables is part of the design, the matching should be very close; even nonsignificant demographic differences can affect the results. Psychiatric controls are not useful for determining whether schizophrenics have a specific defect because nonschizophrenic psychiatric patients may also show that defect. Testing of nonschizophrenic psychiatric patients is useful for determining whether such patients show a given defect but seldom yields evidence with generality concerning which kind of patient shows it the most. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflicting predictions from Broen's and Chapman's theories of schizophrenic thought disorder.

Developed multiple-choice vocabulary items containing a correct alternative which was the dominant (most frequent) response for normal ss, an associative distractor alternative of nearly equal frequency, and an irrelevant alternative. W. Broen and L. Storms's theory predicts that a response which is nondominant for normals can never become dominant for schizophrenics, while L. Chapman's theory predicts that such a response can do so if it expresses a normal response bias. 26 chronic schizophrenics chose significantly more associative than correct responses on items for which 26 normals (matched on sex, age, education, and social position) chose significantly more correct than associative. Results are consistent with chapman's theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object sorting and the heterogeneity of schizophrenia.

Gave 126 schizophrenics who were off drugs, 23 schizophrenics on drugs, and 52 nonpsychotic Ss a 30-item object-sorting test using D. Rapaport et al's passive sorting procedure. Inadequate responses were scored as Restrictive or Expansive. Some schizophrenics made predominantly Restrictive errors, and others made predominantly Expansive errors. Both chronic and newly admitted drug-free schizophrenics exceeded nonpsychotic Ss on the variance of the score of the difference between the 2 kinds of errors. Several potential statistical phenomena that often produce such heightened schizophrenic variance were ruled out. The test identifies patients with diverse error propensities and thus seems promising as a tool for seeking subdisorders within schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A mobile tram system for systematic sampling of ecosystem optical properties

Reliable and repeatable field sampling methods are needed for monitoring ecosystem optical properties linked to carbon flux. Here we describe a tram system, consisting of a dual-detector spectrometer mounted on a robotic cart for mobile sampling of ecosystem spectral reflectance. To illustrate the application of this system for monitoring dynamic ecosystem activity, we illustrate how the tram can be used for exploring the multiple factors influencing the Normalized Difference Vegetation Index (NDVI), a measure of vegetation greenness and a key optical indicator of vegetation carbon dioxide assimilation. With this system, we collected five years of NDVI data for a chaparral ecosystem in Southern California subject to extreme disturbance. Key factors affecting NDVI at this site included snow cover, sky conditions (clear vs. cloudy), time of day, season, species composition, and environmental perturbations such as rainfall, drought and fire. Applications of this tram system include ecosystem monitoring, satellite validation, and developing surface-atmosphere flux models from remote sensing.     

Immune programming

This paper describes ‘Immune Programming’, a paradigm in the field of evolutionary computing taking its inspiration from principles of the vertebrate immune system. These principles are used to derive stack-based computer programs to solve a wide range of problems.An antigen is used to represent the programming problem to be addressed and may be provided in closed form or as an input/output mapping. An antibody set (a repertoire), wherein each member represents a candidate solution, is generated at random from a gene library representing computer instructions. Affinity, the fit of an antibody (a solution candidate) to the antigen (the problem), is analogous to shape-complementarity evident in biological systems. This measure is used to determine both the fate of individual antibodies, and whether or not the algorithm has successfully completed.When a repertoire has not yielded affinity relating algorithm completion, individual antibodies are replaced, cloned, or hypermutated. Replacement occurs according to a replacement probability and yields an entirely new randomly-generated solution candidate when invoked. This randomness (and that of the initial repertoire) provides diversity sufficient to address a wide range of problems. The chance of antibody cloning, wherein a verbatim copy is placed in the new repertoire, occurs proportionally to its affinity and according to a cloning probability. The chances of an effective (high-affinity) antibody being cloned is high, analogous to replication of effective pathogen-fighting antibodies in biological systems. Hypermutation, wherein probability-based replacement of the gene components within an antibody occurs, is also performed on high-affinity entities. However, the extent of mutation is inversely proportional to the antigenic affinity. The effectiveness of this process lies in the supposition that a candidate showing promise is likely similar to the ideal solution.This paper describes the paradigm in detail along with the underlying immune theories and their computational models. A set of sample problems are defined and solved using the algorithm, demonstrating its effectiveness and excellent convergent qualities. Further, the speed of convergence with respect to repertoire size limitations and probability parameters is explored and compared to stack-based genetic programming algorithms.     

Effect of chemical composition on the response of zwitterionic glucose sensitive hydrogels studied by design of experiments

A stimuli‐responsive hydrogel that contains the anionic monomer 3‐acrylamidophenylboronic acid and the cationic monomer N‐[3‐(dimethylamino)propyl]acrylamide binds with cis‐diol groups of glucose molecules selectively and reversibly. Even though such hydrogels have good selectivity for glucose, there are still remaining thresholds that should be overcome to enhance the sensitivity (swelling pressure response magnitude) and to reduce the response time (inverse of 1st order rate constant). In this study, the sensitivity and response time of zwitterionic glucose sensitive hydrogels (GSHs) were studied with three factor DOE analysis. The DOE results show that the molar ratio of 3‐acrylamidophenylboronic acid/N‐[3‐(dimethylamino)propyl]acrylamide and the wt % of monomer in the pregel solution are the most important factors for enhancing the hydrogel sensitivity. In addition, fast response times can best be achieved by decreasing the molar ratio of cross‐linker. The results of this study will be useful as guidelines for the optimal synthesis of glucose sensitive hydrogels. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40667.     

Decomposition of monazite concentrate in sulphuric acid

A sulphuric acid bake-leach process was investigated for the extraction of rare earth elements (REEs), uranium, and thorium from a monazite concentrate. X-ray diffraction analysis showed the formation of water-soluble sulphates that readily dissolved during the water leach step. Nearly complete extraction of REEs, uranium, and thorium was achieved when the concentrate was baked at 250°C for 4?h with a sulphuric acid to concentrate (S/C) weight ratio of 4:1. At the 1:1 sulphuric acid to concentrate ratio ～65% of REEs were leached while only ～2–5% of uranium and thorium were extracted. Temperature (180–250°C) had little effect on the extraction of REEs, but greatly affected the extraction of thorium and uranium. In general, the extraction of thorium and uranium decreased with an increase in temperature. The effect of particle size (48–137?µm) was also tested and found to have little effect on the extraction of REEs. Acid consumption was calculated and found to increase with longer baking times (0.3–0.8?g acid/g concentrate). The major mineralogical phases formed because of the sulphation reaction included potassium cerium sulphate hydrate (2K₂SO₄·Ce(SO₄)₂·2H₂O), lanthanum sulphate hydrate (La₂(SO₄)₃·2H₂O), sodium praseodymium sulphite hydrate (NaPr(SO₃)₂·2H₂O), and neodymium sulphate hydrate (Nd₂(SO₄)₃·5H₂O), all of which were water-soluble.     

3D Bio-Printability of Hybrid Pre-Crosslinked Hydrogels

Maintaining shape fidelity of 3D bio-printed scaffolds with soft biomaterials is an ongoing challenge. Here, a rheological investigation focusing on identifying useful physical and mechanical properties directly related to the geometric fidelity of 3D bio-printed scaffolds is presented. To ensure during- and post-printing shape fidelity of the scaffolds, various percentages of Carboxymethyl Cellulose (CMC) (viscosity enhancer) and different calcium salts (CaCl₂ and CaSO₄, physical cross-linkers) were mixed into alginate before extrusion to realize shape fidelity. The overall solid content of Alginate-Carboxymethyl Cellulose (CMC) was limited to 6%. A set of rheological tests, e.g., flow curves, amplitude tests, and three interval thixotropic tests, were performed to identify and compare the shear-thinning capacity, gelation points, and recovery rate of various compositions. The geometrical fidelity of the fabricated scaffolds was defined by printability and collapse tests. The effect of using multiple cross-linkers simultaneously was assessed. Various large-scale scaffolds were fabricated (up to 5.0 cm) using a pre-crosslinked hybrid. Scaffolds were assessed for the ability to support the growth of Escherichia coli using the Most Probable Number technique to quantify bacteria immediately after inoculation and 24 h later. This pre-crosslinking-based rheological property controlling technique can open a new avenue for 3D bio-fabrication of scaffolds, ensuring proper geometry.     

差动测量方法的比较

文章介绍了用矢量网络分析仪测量差动器件所面临的困难及解决这些困难所用的各种方法并进行了比较，指出了其中最有使用价值的是计算混合模S参数法。