Quantum fast Fourier transform using multilevel atoms

We propose an implementation of the quantum fast Fourier transform algorithm in an entangled system of multilevel atoms. The Fourier transform occurs naturally in the unitary time evolution of energy eigenstates and is used to define an alternative wave-packet basis for quantum information in the atom. A change of basis from energy levels to wave packets amounts to a discrete quantum Fourier transform within each atom. The algorithm then reduces to a series of conditional phase transforms between two entangled atoms in mixed energy and wave-packet bases. We show how to implement such transforms using wave-packet control of the internal states of the ions in the linear ion-trap scheme for quantum computing.     

Systemic inflammatory load in humans is suppressed by consumption of two formulations of dried,encapsulated juice concentrate

Chronic inflammation contributes to an increased risk for developing chronic conditions such as cardiovascular disease, diabetes, and cancer. A high “inflammatory load” is defined as elevated inflammation markers in blood or other tissues. We evaluated several markers of systemic inflammation from healthy adults and tested the hypothesis that two formulations of encapsulated fruit and vegetable juice powder concentrate with added berry powders (FVB) or without (FV) could impact markers of inflammatory load. Using a double‐blind, placebo‐controlled approach, 117 subjects were randomly assigned to receive placebo, FV, or FVB capsules. Blood was drawn at baseline and after 60 d of capsule consumption. We measured inflammatory markers (high sensitivity C‐Reactive Protein, Monocyte Chemotactic Protein‐1, Macrophage Inflammatory Protein 1‐β, and Regulated upon Activation, Normal T cell Expressed and Secreted), superoxide dismutase, and micronutrients (β‐carotene, vitamin C, and vitamin E). Results showed Monocyte Chemotactic Protein‐1, Macrophage Inflammatory Protein 1‐β, and RANTES levels were significantly reduced and superoxide dismutase and micronutrient levels were significantly increased in subjects consuming both FV and FVB, relative to placebo. Data suggest a potential health benefit by consuming either formulation of the encapsulated juice concentrates through their anti‐inflammatory properties.     

Severe and nonsevere events in first onsets versus recurrences of depression: Evidence for stress sensitization.

Overall, research has evidenced support for Post's (1992) model, which asserts that the 1st episode of depression is more likely to be associated with severe life events than are subsequent episodes. In spite of this, there are significant gaps in the understanding of the stress–depression association. This study aimed to address three gaps by (a) identifying the explanatory model underlying the association (stress sensitization vs. stress autonomy), (b) elucidating how the role of stress changes with successive episodes, and (c) examining the role of nonsevere events. The impact and occurrence of severe and nonsevere events in a 5-year longitudinal study of late-adolescent women were examined using Cox regression models. Overall, we found support for the stress sensitization model over the stress autonomy model. Specifically, the impact of nonsevere (but not severe) events was greater in individuals with a history of depression compared with those with no history of depression. In addition, the occurrence of severe (but not nonsevere) events was greater for 1st onsets than recurrences. These effects were modified by event independence. The results were discussed in terms of the underlying mechanisms of the stress–depression association and future directions for research were elaborated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure-based design of inhibitors specific for bacterial thymidylate synthase

Thymidylate synthase is an attractive target for antiproliferative drug design because of its key role in the synthesis of DNA. As such, the enzyme has been widely targeted for anticancer applications. In principle, TS should also be a good target for drugs used to fight infectious disease. In practice, TS is highly conserved across species, and it has proven to be difficult to develop inhibitors that are selective for microbial TS enzymes over the human enzyme. Using the structure of TS from Lactobacillus casei in complex with the nonsubstrate analogue phenolphthalein, inhibitors were designed to take advantage of features of the bacterial enzyme that differ from those of the human enzyme. Upon synthesis and testing, these inhibitors were found to be up to 40-fold selective for the bacterial enzyme over the human enzyme. The crystal structures of two of these inhibitors in complex with TS suggested the design of further compounds. Subsequent synthesis and testing showed that these second-round compounds inhibit the bacterial enzyme at sub-micromolar concentrations, while the human enzyme was not inhibited at detectable levels (selectivities of 100-1000-fold or greater). Although these inhibitors share chemical similarities, X-ray crystal structures reveal that the analogues bind to the enzyme in substantially different orientations. Site-directed mutagenesis experiments suggest that the individual inhibitors may adopt multiple configurations in their complexes with TS.     

Polarization and Partisan Selective Exposure

Today, people can easily select media outlets sharing their political predispositions, a behavior known as partisan selective exposure. Additional research is needed, however, to better understand the causes and consequences of partisan selective exposure. This study investigates the relationship between partisan selective exposure and political polarization using data from the National Annenberg Election Survey. Cross‐sectional results show strong evidence that partisan selective exposure is related to polarization. Over‐time analyses document that partisan selective exposure leads to polarization. Some evidence supports the reverse causal direction, namely that polarization leads to partisan selective exposure. Implications for the study of media effects and normative implications—both positive and negative—are discussed.     

The relationship between stress and depression in first onsets versus recurrences: A meta-analytic review.

S. M. Monroe and K. L. Harkness (see record 2005-02750-005) reviewed the empirical evidence supporting R. M. Post's (see record 1992-43211-001) kindling model, which suggests the 1st episode of depression is more likely to be preceded by major stressors than are subsequent episodes. Their review highlighted the diverse interpretations of Post's premise in the current literature and the changes in research methods that have contributed to this interpretive shift. The authors conducted a meta-analysis (N=13 studies) to test Post's premise that integrated early and recent research and examined potential moderators. A proportion difference effect size was used. Results indicated that 1st onsets of depression were more likely than recurrences to be preceded by severe life events, supporting Post's premise. The moderator analyses suggested that support may be most evident in patient samples and may vary according to age and gender, with less support for Post's premise evidenced in younger samples and in women. Although these results are preliminary, as the analysis included a small number of studies, they suggest that future research should further examine factors that influence the stress-depression relationship with successive recurrences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Built-in Self Testing of Embedded Memories

The authors present a built-in self-test (BIST) method for testing embedded memories. Two algorithms are proposed for self-testing of embedded bedded RAMs, both of which can detect a large variety of stuck-at and non-stuck-at faults. The hardware implementation of the methods requires a hardware test-pattern generator, which produces address, data, and read/write inputs. The output responses of the memory can be compressed by using a parallel input signature analyzer, or they can be compared with expected responses by an output comparator. The layout of memories has been considered in the design of additional BIST circuitry. The authors conclude by evaluating the two schemes on the basis of area overhead, performance degradation, fault coverage, test application time, and testing of self-test circuitry. The BIST overhead is very low and test time is quite short. Six devices, with one of the test schemes, have been manufactured and are in the field.