Role of perfectionism and personality disorder features in response to brief treatment for depression.

Using data from the Treatment of Depression Collaborative Research Program (TDCRP), the authors compared the role of patients' perfectionism and features of personality disorder (PD) in the outcome of brief treatment for depression. Data were extracted as to patients' intake levels of symptoms; perfectionism; and PD features, measured as continuous variables, as well as their symptoms at termination; their contribution to the therapeutic alliance; and their satisfaction with social relations. Poorer therapeutic outcome was demonstrated for patients with elevated levels of perfectionism and odd-eccentric and depressive PD features. Patients' contribution to therapeutic alliance and satisfaction with social relations were predicted by perfectionism but not by PD features. Results highlight the central role played by patients' personality in the course of brief treatment for depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A novel, linear voltage variable MMIC attenuator

Voltage variable attenuators (VVAs) for microwave applications that are fabricated using present technology and design methods feature a nonlinear relationship between the attenuation measured in decibels and the control signal. A novel VVA that features a linear attenuation-control-voltage relationship without the need for external linearization is described. This is accomplished by connecting a number of FET segments in a unique fashion to form a composite FET. The channel resistance of the composite FET constitutes a prescribed function of its gate-source voltage. By careful design the resistance functions that are necessary for realization of linear attenuators are synthesized. The attenuator was fabricated using GaAs MMIC technology employing MESFETs as voltage variable resistors. It is completely passive and does not require a DC supply. The attenuation ranges from 2 to 15 dB over DC to 8 GHz while port impedance is kept close to 50 Ω. The deviation of the attenuation from a straight line is less than 0.2 dB     

Cognitive mechanisms underlying implicit negative self concept in dysphoria.

Whereas explicit measures of the self-concept typically demonstrate a negative bias in depressed individuals, implicit measures such as the Implicit Association Test (IAT), revealed an opposite, positive bias. To address this inconsistent pattern, the authors examined, using a novel paradigm, mental set maintenance (i.e., the difficulty of maintaining active a required mental set) and set operation (the efficiency of executing the mental set while it is maintained). Dysphoric (N = 33) and nondysphoric (N = 30) participants alternated between an IAT focusing on self reference and a matched neutral task. Nondysphorics had greater difficulty in maintaining a negative self reference task compared to a neutral task. Conversely, dysphorics did not exhibit such difficulty, and they maintained a negative self-reference task more easily than nondysphorics. No group differences were evinced in smoothness of set operation. These results suggest that the shield protecting nondysphorics from maintaining negative mental sets is absent in dysphorics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towards identifying the roll motion parameters of a motorcycle simulator

This study aimed at identifying the roll motion parameters of a motorcycle simulator prototype. Experienced motorcyclists tuned the angular physical movement of the mock-up and that of the visual scene to achieve an optimal riding experience during curves. The participants exceeded the rolling angles that would be required in real-world riding, while avoiding leaning the mock-up beyond 10°. In addition, they were more influenced by the speed of the virtual motorcycle than by road curvature, especially in a wide field of view. Heterogeneity was found in the roll applied to the visual scene. The overall patterns suggest that at least when washout is not applied to remove the side forces that in real-world riding are compensated by a centrifugal force, greater roll of the visual at the expense of the mock-up is mandatory to avoid performance biases that might be enhanced due to fear of falling off the simulator. Future roll motion models must take into consideration factors such as riding postures, which might not only influence the forces operating on the rider-motorcycle system, but also how motorcyclists perceive the visual world.     

Knowledge-based spatiotemporal linear abstraction

We present a theoretical framework and a case study for reusing the same conceptual and computational methodology for both temporal abstraction and linear (unidimensional) space abstraction, in a domain (evaluation of traffic-control actions) significantly different from the one (clinical medicine) in which the method was originally used. The method, known asknowledge-based temporal abstraction, abstracts high-level concepts and patterns from time-stamped raw data using a formal theory of domain-specific temporal-abstraction knowledge. We applied this method, originally used to interpret time-oriented clinical data, to the domain of traffic control, in which the monitoring task requires linear pattern matching along both space and time. First we reused the method for creation of unidimensional spatial abstractions over highways, given sensor measurements along each highway measured at the same time point. Second, we reused the method to create temporal abstractions of the traffic behaviour, for the same space segments, but during consecutive time points. We defined the corresponding temporal-abstraction and spatial-abstraction domain-specific knowledge. Our results suggest that (1) the knowledge-base temporal-abstraction method is reusable over time and unidimensional space as well as over significantly different domains; (2) the method can be generalised into a knowledge-based linear-abstraction method, which solves tasks requiring abstraction of data along any linear distance measure; and (3) a spatiotemporal-abstraction method can be assembled, from two copies of the generalised method and a spatial-decomposition mechanism, and is applicable to tasks requiring abstraction of time-oriented data into meaningful spatiotemporal patterns over a linear, decomposable space, such as traffic over a set of highways.     

Chemo-Enzymatic Fluorescence Labeling Of Genomic DNA For Simultaneous Detection Of Global 5-Methylcytosine And 5-Hydroxymethylcytosine**

5-Methylcytosine and 5-hydroxymethylcytosine are epigenetic modifications involved in gene regulation and cancer. We present a new, simple, and high-throughput platform for multi-color epigenetic analysis. The novelty of our approach is the ability to multiplex methylation and de-methylation signals in the same assay. We utilize an engineered methyltransferase enzyme that recognizes and labels all unmodified CpG sites with a fluorescent cofactor. In combination with the already established labeling of the de-methylation mark 5-hydroxymethylcytosine via enzymatic glycosylation, we obtained a robust platform for simultaneous epigenetic analysis of these marks. We assessed the global epigenetic levels in multiple samples of colorectal cancer and observed a 3.5-fold reduction in 5hmC levels but no change in DNA methylation levels between sick and healthy individuals. We also measured epigenetic modifications in chronic lymphocytic leukemia and observed a decrease in both modification levels (5-hydroxymethylcytosine: whole blood 30 %; peripheral blood mononuclear cells (PBMCs) 40 %. 5-methylcytosine: whole blood 53 %; PBMCs 48 %). Our findings propose using a simple blood test as a viable method for analysis, simplifying sample handling in diagnostics. Importantly, our results highlight the assay‘s potential for epigenetic evaluation of clinical samples, benefiting research and patient management.     

Probing Local Force Propagation in Tensed Fibrous Gels

Fibrous hydrogels are a key component of soft animal tissues. They support cellular functions and facilitate efficient mechanical communication between cells. Due to their nonlinear mechanical properties, fibrous materials display non-trivial force propagation at the microscale, that is enhanced compared to that of linear-elastic materials. In the body, tissues are constantly subjected to external loads that tense or compress them, modifying their micro-mechanical properties into an anisotropic state. However, it is unknown how force propagation is modified by this isotropic-to-anisotropic transition. Here, force propagation in tensed fibrin hydrogels is directly measured. Local perturbations are induced by oscillating microspheres using optical tweezers. 1-point and 2-point microrheology are combined to simultaneously measure the shear modulus and force propagation. A mathematical framework to quantify anisotropic force propagation trends is suggested. Results show that force propagation becomes anisotropic in tensed gels, with, surprisingly, stronger response to perturbations perpendicular to the axis of tension. Importantly, external tension can also increase the range of force transmission. Possible implications and future directions for research are discussed. These results suggest a mechanism for favored directions of mechanical communication between cells in a tissue under external loads.     

Sorption of the pharmaceuticals carbamazepine and naproxen to dissolved organic matter: Role of structural fractions

Pharmaceutical compounds and dissolved organic matter (DOM) are co-introduced into the environment by irrigation with reclaimed wastewater and/or application of biosolids. In this study, we evaluate the role and mechanism of interaction of the pharmaceuticals naproxen and carbamazepine with structural fractions of biosolids-derived DOM. Sorption interactions were estimated from dialysis-bag experiments at different pHs.Sorption of naproxen and carbamazepine by the hydrophobic acid fraction exhibited strong pH-dependence. With both pharmaceuticals, the highest sorption coefficients (K_DOC) were at pH 4. With the hydrophobic neutral fraction, pH affected only naproxen sorption (decreasing with increasing pH). Among the hydrophilic DOM fractions, the hydrophilic acid fraction exhibited the highest K_DOC value for carbamazepine, probably due to their bipolar character. In the hydrophilic acid fraction-naproxen system, significant anionic repulsion was observed with increasing pH. The hydrophilic base fraction contains positively charged functional groups. Therefore with increasing ionization of naproxen (with increasing pH), K_DOC to this fraction increased. The hydrophilic neutral fraction exhibited the lowest K_DOC with both studied pharmaceuticals.The K_DOC value of carbamazepine with the bulk DOM sample was higher than the calculated K_DOC value based on sorption by the individual isolated fractions. The opposite trend was observed with naproxen at pH 8: the calculated K_DOC value was higher than the value obtained for the bulk DOM. These results demonstrate that DOM fractions interact with each other and do not act as separate sorption domains.     

Representation of change in controlled medical terminologies

Computer-based systems that support health care require large controlled terminologies to manage names and meanings of data elements. These terminologies are not static, because change in health care is inevitable. To share data and applications in health care, we need standards not only for terminologies and concept representation, but also for representing change. To develop a principled approach to managing change, we analyze the requirements of controlled medical terminologies and consider features that frame knowledge-representation systems have to offer. Based on our analysis, we present a concept model, a set of change operations, and a change-documentation model that may be appropriate for controlled terminologies in health care. We are currently implementing our modeling approach within a computational architecture.