Associative symmetry versus independent associations in the memory for object-location associations.

The formation of associations between objects and locations is a vital aspect of episodic memory. More specifically, remembering the location where one experienced an object and, vice versa, the object one encountered at a specific location are both important elements for the memory of an event. Whether episodic associations are holistic representations of individual components or whether there are unidirectional, separately modifiable connections between them has been investigated nearly exclusively using verbal stimuli. A preliminary conclusion concerning this controversy is that verbal associations are, at least, highly correlated (M. J. Kahana, 2002). This theoretical debate, which in the past has undergone a major empirical effort, is still of relevance for the concurrent global matching models of associative memory (S. E. Clark & S. D. Gronlund, 1996). The authors used variations of a novel object-location learning paradigm to complement the accumulated evidence regarding the nature of episodic associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enthalpy of formation of B2-Fe1−x Al x and B2-(Ni,Fe)1−x Al x

The enthalpy of formation of the ordered B2 phases in the Fe-Al and Fe-Ni-Al systems was measured with very good accuracy using a special, laboratory-built differential-solution calorimeter. The measurements were performed at 1073 K as a function of composition, with an accuracy of about 1 pct. The enthalpy of formation of B2-FeAl is most negative for the composition Fe_0.50Al_0.50 (−36.29 kJ/mol). Compounds with Al contents less than about 40 at. pct show a deviation from the linear dependence of the enthalpy of formation with composition which prevails for Al contents larger than 40 at. pct. Upon replacing Fe by Ni while maintaining a constant Al content, the enthalpy of formation of B2-(Fe,Ni)Al compounds becomes more negative. With decreasing Al content and for a constant Fe/Ni ratio, the enthalpy of formation of the ternary phase becomes less negative.     

The TD-CDMA based UTRA TDD mode

The third-generation mobile radio system UTRA that has been specified in the Third Generation Partnership Project (3GPP) consists of an FDD and a TDD mode. This paper presents the UTRA TDD mode, which is based on TD-CDMA. Important system features are explained in detail. Moreover, an overview of the system architecture and the radio interface protocols is given. Furthermore, the physical layer of UTRA TDD is explained, and the protocol operation is described     

Autobiographies of mental health clients: Psychologists' uses and recommendations.

More than 80% of practicing psychologists recommend self-help books to their psychotherapy clients, but only 33% recommend autobiographies written by mental health patients. In this study, 362 psychologists (38% response) provided clinical information and evaluative ratings on such published autobiographical accounts. The effect of reading autobiographies during treatment was typically considered "somewhat helpful." The titles and evaluative ratings of 40 leading autobiographies are provided as a resource for the practitioner; the most valued were An Unquiet Mind, Nobody Nowhere, Darkness Visible, Out of the Depths, and Girl Interrupted. The clinical advantages of recommending published autobiographies to clients are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cloning and characterization of a novel murine beta chemokine receptor, D6. Comparison to three other related macrophage inflammatory protein-1alpha receptors, CCR-1, CCR-3, and CCR-5

The beta-chemokine macrophage inflammatory protein-1alpha (MIP-1alpha) is chemotactic for many hemopoietic cell types and can inhibit hemopoietic stem cell (HSC) proliferation, effects mediated through G-protein coupled heptahelical receptors. We have isolated cDNAs for seven chemokine receptors, CCR-1 to -5, MIP-1alphaRL1, and a novel cDNA, D6. Chinese hamster ovary cells expressing CCR-1, -3, -5, and D6 bound 125I-murine MIP-1alpha: the order of affinity was D6 > CCR-5 > CCR-1 > CCR-3. Each bound a distinct subset of other beta-chemokines: the order of competition for 125I-murine MIP-1alpha on D6 was murine MIP-1alpha > human and murine MIP-1beta > human RANTES approximately JE > human MCP-3 > human MCP-1. Human MIP-1alpha and the alpha-chemokines did not compete. Like other chemokine receptors, D6 induced transient increases in [Ca2+] in HEK 293 cells upon ligand binding. D6 mRNA was abundant in lung and detectable in many other tissues. Bone marrow cell fractionation demonstrated T-cell and macrophage/monocyte expression of D6, and CCR-1, -3, and -5. Moreover, we could detect expression of CCR-3, CCR-5, and to a greater extent D6 in a cell population enriched for HSCs. Thus, we have characterized four murine beta chemokine receptors that are likely involved in mediating the pro-inflammatory functions of MIP-1alpha and other chemokines, and we present D6, CCR-3, and CCR-5 as candidate receptors in MIP-1alpha-induced HSC inhibition.     

Brain-potential evidence for the time course of access to biographical facts and names of familiar persons.

On seeing familiar persons, biographical (semantic) information is typically retrieved faster and more accurately than name information. Serial stage models explain this pattern by suggesting that access to the name follows the retrieval of semantic information. in contrast, interactive activation and competition (IAC) models hold that both processes start together but name retrieval is slower because of structural peculiarities. With a 2-choice go/no-go procedure based on a semantic and a name-related classification, the authors tested differential predictions of the 2 alternative models for reaction times (RTs) and lateralized readiness potentials (LRP). Both LRP (Experiment 1) and RT (Experiment 2) results are in line with IAC models of face identification and naming. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase

Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg²⁺ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg²⁺ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.     

Loss of nitrogen from urea applied to rainfed wheat in varying rainfall zones in northern Syria

Fertilizer-applied Nitrogen (N) may be lost from the soil by various mechanisms, i.e., runoff, leaching, denitrification, and volatilization. The latter process is of primary concern in calcareous soils of arid and semi-arid regions, especially when urea is used. In this field study from northern Syria, urea alone, urea with either an incorporated urease inhibitor, phenylphosphorodiamidate, or an experimental bran-wax coating were evaluated on wheat for two cropping seasons at two experimental stations with varying average seasonal rainfall (340 mm, 270 mm). Loss of N was assessed with ¹⁵N by mass balance, i.e., the amount of N applied minus the crop N uptake and N remaining in the soil. Crop yields and N uptake were related to seasonal rainfall. Losses of N, apparently as volatilized NH₃, were relatively low at both sites, i.e., 11–18%. However, compared to the unmodified urea, neither the incorporated urease inhibitor nor the bran-wax coating had any effect on yields, N uptake or N loss. While urea hydrolysis is normally rapid, it may be delayed by dry conditions at the soil surface; similarly, unusually cold periods may delay nitrification following hydrolysis. Thus, under the cool-season conditions of rainfed cropping in the Middle East, efficient use of urea is not likely to be achieved by modification of the urea but by conventional management practices that ensure pre-plant soil incorporation or topdressing during early spring rains.