PaleoNet: paleontology, publication and community in the digital age

PaleoNet is an electronic communications system that realizes the concept of a global ‘paleontological community’. It was begun in a conscious attempt to overcome the disciplinary, geographical, and occupational barriers that subdivide that community into sectors and impede information flow. Operationally PaleoNet consists of a listserver and associated web sites in the US and UK. Over the past 8 years of operation PaleoNet has more than met expectations set for it to become one of the most unconventional and innovative aspects of the contemporary paleontological scene. In particular, PaleoNet challenges conventional notions of formal scientific publication as the primary means paleontologists use to communicate with colleagues.     

The emotional Stroop task and psychopathology.

Attentional bias is a central feature of many cognitive theories of psychopathology. One of the most frequent methods of investigating such bias has been an emotional analog of the Stroop task. In this task, participants name the colors in which words are printed, and the words vary in their relevance to each theme of psychopathology. The authors review research showing that patients are often slower to name the color of a word associated with concerns relevant to their clinical condition. They address the causes and mechanisms underlying the phenomenon, focusing on J. D. Cohen, K. Dunbar, and J. L. McClelland's (see record 1990-27437-001) parallel distributed processing model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Whither cognitive bias modification research? Commentary on the special section articles.

This commentary reviews key theoretical, methodological, and clinical issues raised by recent research on cognitive bias modification (CBM). The authors identify the major ways in which the new work reported within this special section extends earlier CBM research. In particular, they note that it considers a wider range of participants, includes a greater diversity of symptoms measures, and targets for change a broader array of processing biases than previously has been the case. Furthermore, they point out that the present work develops and employs a more diverse arsenal of bias modification procedures, in some cases delivered across extended periods of time within naturalistic settings. They also draw attention to methodological limitations associated with the current studies, offering recommendations concerning how future CBM research might profitably build upon these exciting new directions while overcoming such limitations. Finally, they evaluate the theoretical and applied implications of the reported findings, discussing their capacity to illuminate the causal contributions made by cognitive bias to emotional vulnerability and their promise concerning the potential therapeutic value of CBM as a clinical tool. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrins Increase Sarcoplasmic Reticulum Activity for Excitation—Contraction Coupling in Human Stem Cell-Derived Cardiomyocytes

Engagement of the sarcoplasmic reticulum (SR) Ca²⁺ stores for excitation–contraction (EC)-coupling is a fundamental feature of cardiac muscle cells. Extracellular matrix (ECM) proteins that form the extracellular scaffolding supporting cardiac contractile activity are thought to play an integral role in the modulation of EC-coupling. At baseline, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) show poor utilisation of SR Ca²⁺ stores, leading to inefficient EC-coupling, like developing or human CMs in cardiac diseases such as heart failure. We hypothesised that integrin ligand–receptor interactions between ECM proteins and CMs recruit the SR to Ca²⁺ cycling during EC-coupling. hiPSC-CM monolayers were cultured on fibronectin-coated glass before 24 h treatment with fibril-forming peptides containing the integrin-binding tripeptide sequence arginine–glycine–aspartic acid (2 mM). Micropipette application of 40 mM caffeine in standard or Na⁺/Ca²⁺-free Tyrode’s solutions was used to assess the Ca²⁺ removal mechanisms. Microelectrode recordings were conducted to analyse action potentials in current-clamp. Confocal images of labelled hiPSC-CMs were analysed to investigate hiPSC-CM morphology and ultrastructural arrangements in Ca²⁺ release units. This study demonstrates that peptides containing the integrin-binding sequence arginine–glycine–aspartic acid (1) abbreviate hiPSC-CM Ca²⁺ transient and action potential duration, (2) increase co-localisation between L-type Ca²⁺ channels and ryanodine receptors involved in EC-coupling, and (3) increase the rate of SR-mediated Ca²⁺ cycling. We conclude that integrin-binding peptides induce recruitment of the SR for Ca²⁺ cycling in EC-coupling through functional and structural improvements and demonstrate the importance of the ECM in modulating cardiomyocyte function in physiology.     

Purification and Use of Glycomacropeptide for Nutritional Management of Phenylketonuria

ABSTRACT:  Individuals with phenylketonuria (PKU) cannot metabolize phenylalanine (Phe) and must adhere to a low-Phe diet in which most dietary protein is provided by a Phe-free amino acid formula. Glycomacropeptide (GMP) is the only naturally occurring protein that does not contain Phe, and is of interest as a source of protein for dietary management of PKU. However, commercially available GMP contains too much Phe from residual whey proteins and does not contain adequate levels of all the indispensable amino acids to provide a nutritionally complete protein. The aim of this study was to increase purity of GMP and develop a mass balance calculation for indispensable amino acid supplementation of GMP foods. Cation exchange chromatography, ultrafiltration/diafiltration, and lyophilization were used at the pilot plant scale to decrease Phe. Enough purified GMP (5 kg) was manufactured to provide 15 PKU subjects with a 4-d diet in which the majority of protein was from GMP foods. A mass balance was used to supplement GMP foods so that all indispensable amino acids met or exceeded the daily recommended intake. GMP foods were tested in a human clinical trial as a replacement for the traditional amino acid formula. Nutritionally complete GMP foods created with high purity GMP provide individuals with PKU with more options to manage PKU, which may lead to improved compliance and quality of life.     

Improving data quality for environmental fate models: a least-squares adjustment procedure for harmonizing physicochemical properties of organic compounds

Physicochemical properties (vapor pressure, aqueous solubility, octanol solubility, Henry's law constant, and octanol-air and octanol-water partition coefficients) and their temperature dependencies are required for fate modeling of environmental pollutants. To be internally consistent, measured values for these properties often must be adjusted. The goal of adjusting the property values for consistency is to more accurately estimate the true values. However, consistency and accuracy are not synonymous. If there are systematic errors in one property, then adjustment for consistency may reduce the accuracy of other property data. Here, we provide methods for achieving consistency and improving accuracy in the selection of partitioning properties from literature sources. First, we show that a widely used procedure does not always minimize the adjustments of property values derived from the literature when harmonizing them according to thermodynamic constraints. In such cases, the final adjusted values (FAVs) are unnecessarily different from the literature-derived values (LDVs) selected from measurements. We present an improved procedure based on the theory of least squares that minimizes the adjustment of LDVs and allows quantitative propagation of uncertainty from LDVs to FAVs. When this procedure is applied to partitioning properties for 30 organic chemicals, FAVs obtained differ by up to 30% from those calculated with the current adjustment procedure. Second, we point out that the adjustment procedure is only appropriate for correcting random errors in measurement data. Biased LDVs must be identified and corrected prior to harmonization. Using a set of 16 PCB congeners as a case study, we provide methods to identify biased data and discuss possible sources of bias. We present a new interpretation of property data for the PCBs and a new set of internally consistent properties and quantitative structure-property relationships that we recommend as the best currently available.