TULP1 and TUB Are Required for Specific Localization of PRCD to Photoreceptor Outer Segments

Photoreceptor disc component (PRCD) is a small protein which is exclusively localized to photoreceptor outer segments, and is involved in the formation of photoreceptor outer segment discs. Mutations in PRCD are associated with retinal degeneration in humans, mice, and dogs. The purpose of this work was to identify PRCD-binding proteins in the retina. PRCD protein-protein interactions were identified when implementing the Ras recruitment system (RRS), a cytoplasmic-based yeast two-hybrid system, on a bovine retina cDNA library. An interaction between PRCD and tubby-like protein 1 (TULP1) was identified. Co-immunoprecipitation in transfected mammalian cells confirmed that PRCD interacts with TULP1, as well as with its homolog, TUB. These interactions were mediated by TULP1 and TUB highly conserved C-terminal tubby domain. PRCD localization was altered in the retinas of TULP1- and TUB-deficient mice. These results show that TULP1 and TUB, which are involved in the vesicular trafficking of several photoreceptor proteins from the inner segment to the outer segment, are also required for PRCD exclusive localization to photoreceptor outer segment discs.     

Emulsion templated bicontinuous hydrophobic-hydrophilic polymers: Loading and release

Water absorption is often poor in hydrophobic polyHIPEs, porous polymers synthesized within high internal phase emulsions (HIPEs). This paper describes bicontinuous polyHIPEs, the simultaneous polymerization of hydrophobic monomers (external phase) and hydrophilic monomers (internal phase). Integrating hydrogels within polyHIPEs extended the release of water-soluble dye from 10 h to more than 10 days. PolyHIPE capillary action promoted the rapid distribution of water throughout the hydrogel. The diffusion pathway in this bicontinuous system was similar to diffusion through an assembly of polydisperse spheres. The copolymerization of the hydrophilic monomers with the monomers in the external phase enhanced the hydrophilicity of the scaffold, reduced the modulus of the hydrated polyHIPE, and reduced the tortuosity of the diffusion path. Pre-polymerization of the external phase reduced the extent of copolymerization, enhanced the modulus, sealed the interconnecting holes, reduced the capillary action, increased the tortuosity, and extended the release time to 3 weeks.     

A self-agency bias in preschoolers' causal inferences.

Preschoolers' causal learning from intentional actions—causal interventions—is subject to a self-agency bias. The authors propose that this bias is evidence-based, in other words, that it is responsive to causal uncertainty. In the current studies, two causes (one child controlled, one experimenter controlled) were associated with one or two effects, first independently, then simultaneously. When initial independent effects were probabilistic, and thus subsequent simultaneous actions were causally ambiguous, children showed a self-agency bias. Children showed no bias when initial effects were deterministic. Further controls established that children's self-agency bias is not a wholesale preference but rather is influenced by uncertainty in causal evidence. These results demonstrate that children's own experience of action influences their causal learning, and the findings suggest possible benefits in uncertain and ambiguous everyday learning contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One‐Pot Chemoenzymatic Cascade for Labeling of the Epigenetic Marker 5‐Hydroxymethylcytosine

The epigenetic DNA modification 5‐hydroxymethylcytosine (5‐hmC) is important for the regulation of gene expression during development and in tumorigenesis. 5‐hmC can be selectively glycosylated by T4 β‐glucosyltransferase (β‐GT); introduction of an azide on the attached sugar provides a chemical handle for isolation or fluorescent tagging of 5‐hmC residues by click chemistry. This approach has not been broadly adopted because of the challenging synthesis and limited commercial availability of the glycosylation substrate, 6‐deoxy‐6‐azido‐α‐D ‐glucopyranoside. We report the enzyme‐assisted synthesis of this precursor by the uridylyltransferase from Pasteurella multocida (PmGlmU). We were able to directly label 5‐hmC in genomic DNA by an enzymatic cascade involving successive action of PmGlmU and β‐GT. This is a facile and cost‐effective one‐pot chemoenzymatic methodology for 5‐hmC analysis.     

Depression among Latinos in the United States: A meta-analytic review.

The authors conducted a meta-analytic review to assess the prevalence of major depressive disorder and depressive symptoms among Latinos compared with non-Latino Whites in the United States using community-based data. Random-effects estimates were calculated for 8 studies meeting inclusion criteria that reported lifetime prevalence of major depressive disorder (combined N = 76,270) and for 23 studies meeting inclusion criteria that reported current prevalence of depressive symptoms (combined N = 38,997). Findings did not indicate a group difference in lifetime prevalence of major depressive disorder (odds ratio = 0.89, 95% confidence interval = 0.72, 1.10). Latinos reported more depressive symptoms than non-Latino Whites (standardized mean difference = 0.19, 95% confidence interval = 0.12, 0.25); however, this effect was small and does not appear to suggest a clinically meaningful preponderance of depressive symptoms among Latinos. Findings are examined in the context of theories on vulnerability and resilience, and recommendations for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Signatures of cooperative effects and transport mechanisms in conductance histograms

We present a computational investigation into the line shapes of peaks in conductance histograms, finding that they possess high information content. In particular, the histogram peak associated with conduction through a single molecule elucidates the electron transport mechanism and is generally well-described by beta distributions. A statistical analysis of the peak corresponding to conduction through two molecules reveals the presence of cooperative effects between the molecules and also provides insight into the underlying conduction channels. This work describes tools for extracting additional interpretations from experimental statistical data, helping us better understand electron transport processes.     

Novel reduction of mercury (II) by mercury-sensitive dissimilatory metal reducing bacteria

The dissimilatory metal reducing bacterium (DMRB) Shewanella oneidensis MR-1 reduces ionic mercury (Hg[II]) to elemental mercury (Hg[0]) by an activity not related to the MerA mercuric reductase. In S. oneidensis, this activity is constitutive and effective at Hg(II) concentrations too low to induce mer operon functions. Reduction of Hg(II) by MR-1 required the presence of electron donors and electron acceptors. Reduction occurred with oxygen or fumarate, but had the highest rate when ferric oxyhydroxide was used as a terminal electron acceptor. Geobacter sulfurreducens PCA and Geobacter metallireducens GS-15 reduced Hg(II) to Hg(0) with activity comparable to MR-1; however, neither the DMRB Anaeromyxobacter dehalogenans 2CP-C nor the nitrate reducer Pseudomonas stutzeri OX-1 reduced Hg(II) during growth. This discovery of constitutive mercury reduction among anaerobes has implications to the mobilization of mercury and production of methylmercury in anoxic environments.     

The associative memory deficit of older adults: The role of strategy utilization.

Past research has established an associative deficit hypothesis (e.g., M. Naveh-Benjamin, 2000) that attributes part of older adults' poor episodic memory performance to their difficulty in creating and retrieving cohesive episodes. Here, the authors evaluate the degree to which this deficit can be reduced by older adults' use of associative strategies. Young and older adults learned word pairs under either intentional-learning instructions or instructions eliciting associative strategies either at encoding or both at encoding and at retrieval, and they then took tests on their memory for both the components and the associations. Results replicated the associative deficit of older adults under intentional-learning instructions. In addition, they showed that instructions to use appropriate associative strategies during either encoding or, even more so, during encoding and retrieval resulted in a significant decrease in the associative deficit. The theoretical and applied implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading cursive handwriting by alignment of letter prototypes

We describe a new approach to the visual recognition of cursive handwriting. An effort is made to attain human-like performance by using a method based on pictorial alignment and on a model of the process of handwriting. The alignment approach permits recognition of character instances that appear embedded in connected strings. A system embodying this approach has been implemented and tested on five different word sets. The performance was stable both across words and across writers. The system exhibited a substantial ability to interpret cursive connected strings without recourse to lexical knowledge.SU is partially supported by NSF grant IRI-8900267.