bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing of global and local information in memory
Authors: Rumiati Rino , Nicoletti Roberto , Job Remo
Published: September 2011

The experiments reported in this paper were designed to test how global and local information are processed by the memory system. When subjects are required to match a given letter with either a previously presented large capital letter or the small capital letters comprising it, (1) responses to the global level (i.e. the big letter) are faster than responses to the local level (i.e. the small letters), and (2) responses to the latter level only are affected by the consistency between the large and the small letters (Experiment 2), a pattern similar to that obtained in perception (Experiment 1). Such results obtain when subjects are required to attend to only one level with a short ISI between the first and second stimulus, but not when a longer ISI is used (Experiment 5) or when subjects are required to attend to both levels at the same time (Experiments 3 and 4). The results are discussed in the light of a model that postulates a temporal precedence of the global information over the local one at the perceptual level.
Item Identification Time and Rehearsal Rate as Predictors of Memory Span in Children
Authors: Hitch G. J. , Halliday M. S. , Littler J. E.
Published: September 2011

According to the working memory model of Baddeley and Hitch (1974), the sensitivity of memory span to word length arises from the time taken to rehearse items in a speech-based “articulatory loop”. Alternatively, it has been suggested that the word-length effect may result from differences in the speed of perceptual processes of item identification. Changes in the speed of rehearsal and of item identification have also been claimed to contribute to the growth of memory span that is seen in development. In order to compare these two variables directly, groups of children aged 8 and 11 were assessed on memory span for words of one, two, and three syllables; span under articulatory suppression; rehearsal rate; and item identification time. Span was found to be a linear function of rehearsal rate across differences in both word length and age. The word-length effect was unrelated to item identification time and was diminished by articulatory suppression. These results show that the word-length effect reflects rehearsal and not item identification processes. However, the results also suggest that changes in item identification time contribute to developmental differences in span when articulation is suppressed. A distinction between item identification and rehearsal effects can be readily interpreted in terms of the working memory model if it is assumed that they indicate the efficiency of different subsystems involved in span.
A Parametric Study of Learned Helplessness in Humans
Authors: Barber James G.
Published: September 2011

In two experiments designed to assess the effect of varying amounts of exposure to noncontingency training, it was discovered that performance decrements could be produced after relatively brief training and again after extended training. Between these conditions was a period of recovery during which no performance deficits were evident. There was also a tendency for individual differences in motivation to moderate deficits following brief but not extended training. A four-stage model is proposed to account for these results. In response to uncontrollable outcomes, individuals are said to pass through a phase of no effect, followed by temporary helplessness, recovery, and final helplessness. The model also proposes that motivational differences and perceptions of noncontingency exert independent and opposing influences on learned helplessness deficits.
The Appearance of Surfaces Specified by Motion Parallax and Binocular Disparity
Authors: Rogers Brian J. , Collett Thomas S.
Published: September 2011

The experiments reported in this paper were designed to investigate how depth information from binocular disparity and motion parallax cues is integrated in the human visual system. Observers viewed simulated 3-D corrugated surfaces that translated to and fro across their line of sight. The depth of the corrugations was specified by either motion parallax, or binocular disparities, or some combination of the two. The amount of perceived depth in the corrugations was measured using a matching technique.

A monocularly viewed surface specified by parallax alone was seen as a rigid, corrugated surface translating along a fronto-parallel path. The perceived depth of the corrugations increased monotonically with the amount of parallax motion, just as if observers were viewing an equivalent real surface that produced the same parallax transformation. With binocular viewing and zero disparities between the images seen by the two eyes, the perceived depth was only about half of that predicted by the monocular cue. In addition, this binocularly viewed surface appeared to rotate about a vertical axis as it translated to and fro. With other combinations of motion parallax and binocular disparity, parallax only affected the perceived depth when the disparity gradients of the corrugations were shallow. The discrepancy between the parallax and disparity signals was typically resolved by an apparent rotation of the surface as it translated to and fro. The results are consistent with the idea that the visual system attempts to minimize the discrepancies between (1) the depth signalled by disparity and that required by a particular interpretation of the parallax transformation and (2) the amount of rotation required by that interpretation and the amount of rotation signalled by other cues in the display.
Ageing and bilingualism: Absence of a “bilingual advantage” in Stroop interference in a nonimmigrant sample
Authors: Kousaie Shanna , Phillips Natalie A.
Published: September 2011

Previous research has found an advantage for bilinguals relative to monolinguals on tasks of attentional control. This advantage has been found to be larger in older adults than in young adults, suggesting that bilingualism provides a buffer against age-related declines in executive functioning. Using a computerized Stroop task in a nonimmigrant sample of young and older monolinguals and bilinguals, the current investigation tried to replicate previous findings of a bilingual advantage. A bilingual advantage would have been demonstrated by smaller Stroop interference (i.e., smaller increases in response time for incongruent than for neutral trials) for bilinguals than for monolinguals. The results showed that bilingual young adults showed a general speed advantage relative to their monolingual counterparts, but this was not associated with smaller Stroop interference. Older adults showed no effect of bilingualism. Thus, the present investigation does not find evidence of a bilingual advantage in young or older adults and suggests limits to the robustness and/or specificity of previous findings.
Smooth Lie group actions are parametrized diffeological subgroups
Authors: Iglesias-Zemmour Patrick , Karshon Yael
Published: September 2011

We show that every effective smooth action of a Lie group

G
G

on a manifold

M
M

is a diffeomorphism from

G
G

onto its image in

D
i
f
f

(
M
)

\mathrm {Diff}(M)

, where the image is equipped with the subset diffeology of the functional diffeology.
Apical–basal polarity in Drosophila neuroblasts is independent of vesicular trafficking
Authors: Halbsgut Nils , Linnemannstöns Karen , Zimmermann Laura Isabel , Wodarz Andreas
Published: September 2011

The possession of apical–basal polarity is a common feature of epithelia and neural stem cells, so-called neuroblasts (NBs). In Drosophila, an evolutionarily conserved protein complex consisting of atypical protein kinase C and the scaffolding proteins Bazooka/PAR-3 and PAR-6 controls the polarity of both cell types. The components of this complex localize to the apical junctional region of epithelial cells and form an apical crescent in NBs. In epithelia, the PAR proteins interact with the cellular machinery for polarized exocytosis and endocytosis, both of which are essential for the establishment of plasma membrane polarity. In NBs, many cortical proteins show a strongly polarized subcellular localization, but there is little evidence for the existence of distinct apical and basolateral plasma membrane domains, raising the question of whether vesicular trafficking is required for polarization of NBs. We analyzed the polarity of NBs mutant for essential regulators of the main exocytic and endocytic pathways. Surprisingly, we found that none of these mutations affected NB polarity, demonstrating that NB cortical polarity is independent of plasma membrane polarity and that the PAR proteins function in a cell type–specific manner.
Effect of RS4 Resistant Starch on Extruded Ready‐to‐Eat (RTE) Breakfast Cereal Quality
Authors: Miller Rebecca A. , Jeong Juhui , Maningat Clodualdo C.
Published: September 2011

A phosphorylated cross‐linked type 4 resistant wheat starch (RS4) containing 85.5% total dietary fiber (TDF) replaced 5–20% of the whole corn flour in an extruded ring‐shaped ready‐to‐eat breakfast cereal formulation. TDF content of the dry ingredient blend increased by roughly 3.6% for every 5% of added RS4. TDF loss during extrusion processing increased as RS4 level increased; however, a high percentage (78–89%) of the TDF content was retained in the final product. Product density increased as level of RS4 increased, but no effect on the specific mechanical energy was observed. X‐ray microtomography showed that RS4 addition did not affect internal air‐cell wall thickness, air‐cell size, or porosity. Moreover, addition of 5 or 10% RS4 did not affect expansion, physical appearance, initial crispness, or bowl life of the cereal rings. High levels of RS4 (15 and 20%) decreased cereal ring diameter but increased initial (dry) product crispness and extended bowl life. In general, RS4 addition level did not affect moisture content or moisture uptake of cereal rings during soaking in milk. Furthermore, moisture content and moisture uptake did not appear to influence the crispness of milk‐soaked cereal rings.
Mutations in the Antiviral RNAi Defense Pathway Modify Brome mosaic virus RNA Recombinant Profiles
Authors: Dzianott Aleksandra , Sztuba-Solińska Joanna , Bujarski Jozef J.
Published: September 2011

RNA interference (RNAi) mechanism targets viral RNA for degradation. To test whether RNAi gene products contributed to viral RNA recombination, a series of Arabidopsis thaliana RNAi-defective mutants were infected with Brome mosaic virus (BMV) RNAs that have been engineered to support crossovers within the RNA3 segment. Single-cross RNA3-RNA1, RNA3-RNA2, and RNA3-RNA3 recombinants accumulated in both the wild-type (wt) and all knock-out lines at comparable frequencies. However, a reduced accumulation of novel 3′ mosaic RNA3 recombinants was observed in ago1, dcl2, dcl4, and rdr6 lines but not in wt Col-0 or the dcl3 line. A BMV replicase mutant accumulated a low level of RNA3-RNA1 single-cross recombinants in Col-0 plants while, in a dcl2 dcl4 double mutant, the formation of both RNA3-RNA1 and mosaic recombinants was at a low level. A control infection in the cpr5-2 mutant, a more susceptible BMV Arabidopsis host, generated similar-to-Col-0 profiles of both single-cross and mosaic recombinants, indicating that recombinant profiles were, to some extent, independent of a viral replication rate. Also, the relative growth experiments revealed similar selection pressure for recombinants among the host lines. Thus, the altered recombinant RNA profiles have originated at the level of recombinant formation rather than because of altered selection. In conclusion, the viral replicase and the host RNAi gene products contribute in distinct ways to BMV RNA recombination. Our studies reveal that the antiviral RNAi mechanisms are utilized by plant RNA viruses to increase their variability, reminiscent of phenomena previously demonstrated in fungi.
Effect of loading conditions on the dissociation behaviour of catch bond clusters
Authors: Sun L. , Cheng Q. H. , Gao H. J. , Zhang Y. W.
Published: September 2011

Under increasing tensile load, the lifetime of a single catch bond counterintuitively increases up to a maximum and then decreases exponentially like a slip bond. So far, the characteristics of single catch bond dissociation have been extensively studied. However, it remains unclear how a cluster of catch bonds behaves under tensile load. We perform computational analysis on the following models to examine the characteristics of clustered catch bonds: (i) clusters of catch bonds with equal load sharing, (ii) clusters of catch bonds with linear load sharing, and (iii) clusters of catch bonds in micropipette-manipulated cell detachment. We focus on the differences between the slip and catch bond clusters, identifying the critical factors for exhibiting the characteristics of catch bond mechanism for the multiple-bond system. Our computation reveals that for a multiple-bond cluster, the catch bond behaviour could only manifest itself under relatively uniform loading conditions and at certain stages of decohesion, explaining the difficulties in observing the catch bond mechanism under real biological conditions.
Personality and problem-solving performance explain competitive ability in the wild
Authors: Cole Ella F. , Quinn John L.
Published: September 2011

Competitive ability is a major determinant of fitness, but why individuals vary so much in their competitiveness remains only partially understood. One increasingly prevalent view is that realized competitive ability varies because it represents alternative strategies that arise because of the costs associated with competitiveness. Here we use a population of great tits (
Parus major
) to explore whether individual differences in competitive ability when foraging can be explained by two traits that have previously been linked to alternative behavioural strategies: the personality trait ‘exploration behaviour’ and a simple cognitive trait, ‘innovative problem-solving performance’. We assayed these traits under standardized conditions in captivity and then measured competitive ability at feeders with restricted access in the wild. Competitive ability was repeatable within individual males across days and correlated positively with exploration behaviour, representing the first such demonstration of a link between a personality trait and both competitive ability and food intake in the wild. Competitive ability was also simultaneously negatively correlated with problem-solving performance; individuals who were poor competitors were good at problem-solving. Rather than being the result of variation in ‘individual quality’, our results support the hypothesis that individual variation in competitive ability can be explained by alternative behavioural strategies.
Semiochemical compounds of preen secretion reflect genetic make-up in a seabird species
Authors: Leclaire Sarah , Merkling Thomas , Raynaud Christine , Mulard Hervé , Bessière Jean-Marie , Lhuillier Émeline , Hatch Scott A. , Danchin Étienne
Published: September 2011

Several vertebrates choose their mate according to genetic heterozygosity and relatedness, and use odour cues to assess their conspecifics' genetic make-up. In birds, although several species (including the black-legged kittiwake) exhibit non-random mating according to genetic traits, the cues used to assess genetic characteristics remain unknown. The importance of olfaction in birds' social behaviour is gaining attention among researchers, and it has been suggested that, as in other vertebrates, bird body scent may convey information about genetic traits. Here, we combined gas chromatography data and genetic analyses at microsatellite loci to test whether semiochemical messages in preen secretion of kittiwakes carried information about genetic heterozygosity and relatedness. Semiochemical profile was correlated with heterozygosity in males and females, while semiochemical distance was correlated with genetic distance only in male–male dyads. Our study is the first to demonstrate a link between odour and genetics in birds, which sets the stage for the existence of sophisticated odour-based mechanisms of mate choice also in birds.
Multivesicular Bodies Mature from the Trans-Golgi Network/Early Endosome in Arabidopsis
Authors: Scheuring David , Viotti Corrado , Krüger Falco , Künzl Fabian , Sturm Silke , Bubeck Julia , Hillmer Stefan , Frigerio Lorenzo , Robinson David G. , Pimpl Peter , Schumacher Karin
Published: September 2011

The plant trans-Golgi network/early endosome (TGN/EE) is a major hub for secretory and endocytic trafficking with complex molecular mechanisms controlling sorting and transport of cargo. Vacuolar transport from the TGN/EE to multivesicular bodies/late endosomes (MVBs/LEs) is assumed to occur via clathrin-coated vesicles, although direct proof for their participation is missing. Here, we present evidence that post-TGN transport toward lytic vacuoles occurs independently of clathrin and that MVBs/LEs are derived from the TGN/EE through maturation. We show that the V-ATPase inhibitor concanamycin A significantly reduces the number of MVBs and causes TGN and MVB markers to colocalize in Arabidopsis thaliana roots. Ultrastructural analysis reveals the formation of MVBs from the TGN/EE and their fusion with the vacuole. The localization of the ESCRT components VPS28, VPS22, and VPS2 at the TGN/EE and MVBs/LEs indicates that the formation of intraluminal vesicles starts already at the TGN/EE. Accordingly, a dominant-negative mutant of VPS2 causes TGN and MVB markers to colocalize and blocks vacuolar transport. RNA interference–mediated knockdown of the annexin ANNAT3 also yields the same phenotype. Together, these data indicate that MVBs originate from the TGN/EE in a process that requires the action of ESCRT for the formation of intraluminal vesicles and annexins for the final step of releasing MVBs as a transport carrier to the vacuole.
MutS HOMOLOG1 Is a Nucleoid Protein That Alters Mitochondrial and Plastid Properties and Plant Response to High Light
Authors: Xu Ying-Zhi , Arrieta-Montiel Maria P. , Virdi Kamaldeep S. , de Paula Wilson B.M. , Widhalm Joshua R. , Basset Gilles J. , Davila Jaime I. , Elthon Thomas E. , Elowsky Christian G. , Sato Shirley J. , Clemente Thomas E. , Mackenzie Sally A.
Published: September 2011

Mitochondrial-plastid interdependence within the plant cell is presumed to be essential, but measurable demonstration of this intimate interaction is difficult. At the level of cellular metabolism, several biosynthetic pathways involve both mitochondrial- and plastid-localized steps. However, at an environmental response level, it is not clear how the two organelles intersect in programmed cellular responses. Here, we provide evidence, using genetic perturbation of the MutS Homolog1 (MSH1) nuclear gene in five plant species, that MSH1 functions within the mitochondrion and plastid to influence organellar genome behavior and plant growth patterns. The mitochondrial form of the protein participates in DNA recombination surveillance, with disruption of the gene resulting in enhanced mitochondrial genome recombination at numerous repeated sequences. The plastid-localized form of the protein interacts with the plastid genome and influences genome stability and plastid development, with its disruption leading to variegation of the plant. These developmental changes include altered patterns of nuclear gene expression. Consistency of plastid and mitochondrial response across both monocot and dicot species indicate that the dual-functioning nature of MSH1 is well conserved. Variegated tissues show changes in redox status together with enhanced plant survival and reproduction under photooxidative light conditions, evidence that the plastid changes triggered in this study comprise an adaptive response to naturally occurring light stress.
To live as mentally disabled in the risk society
Authors: ERIKSSON B. G. , HUMMELVOLL J. K.
Published: September 2011

Accessible summary

Society undergoes long‐term changes that in many ways are hard to visualize, explore, and grasp. Many previous obstacles, problems and risks of the everyday life have been solved, but new ones have emerged. Characteristics of these new risks are that they might appear anywhere, are hard to protect against, and are created by human actions. An assumption might be that they strike harder against already vulnerable groups than others. This goes for other societal changes as well, like the demand for ever‐raising technical skills, where electronic communication sometimes replaces face‐to‐face contacts.

In order to learn more about what these changes really means for persons with mental disabilities, a study was made together with members of a user‐governed centre in Eastern Norway. The group met three times in a focus group interview, the results were presented and discussed in an open meeting, and reported in a research report. This article contains a deepened analysis of how it is to live in this partly new society (the risk society) for persons who experience mental disability.

The results show that the characteristics of the risk society are identified of and well known among the members. Fast changes create feelings of alienation, uncertainty, and stress. Societal institutions are sometimes hard to reach, abstract, impersonal, and formalistic. The technological development increases the demands, but opens at the same time new possibilities. The Centre offers a new way of building companionship, trust in others, and a new meaningful everyday life.

The contemporary society is to some extent characterized by longitudinal changes, towards individualization, uncertainty, and risk. Numerous risks and dangers in modern society have been mastered, while others have emerged, often created by human actions. The individual's freedom of choice has increased, but also the responsibility for the choices made. In this society, the risk society, there is a greater need for formative and situation‐related knowledge to manage risks. The aims of this paper are to discuss the concept of risk society in the light of everyday experiences made by people with mental disabilities, how challenges can be mastered and positive possibilities can be utilized. Data collection was made through a multistage focus group, and the data were analysed by qualitative content analysis. The results show that characteristics of the risk society are identified by people with mental disabilities. Change and uncertainty, obstacles created by societal institutions, lack of trust, and the need of adapted working conditions are frequently experienced, impersonal relations and feelings of loneliness as well. However, these conditions can be partly counteracted by belonging to an alternative fellowship, which might lead to quality of life‐related personal improvements.
Pharmacokinetics and platelet aggregation inhibitory effects of a novel intravenous formulation of clopidogrel in humans
Authors: Cushing Daniel J , Souney Paul F , Cooper Warren D , Mosher Gerald L , Adams Michael P , Machatha Stephen , Zhang Bing , Kowey Peter R
Published: September 2011

1. PM103 is an intravenous formulation of clopidogrel being developed as an alternative to oral clopidogrel to provide for dosing flexibility in the emergent clinical setting. The present first‐in‐human study assessed the pharmacokinetic and pharmacodynamic effects of PM103 and its safety in 144 healthy human subjects.

2. The present was a randomized open‐label parallel‐group trial. Single intravenous doses of PM103 (0.1, 1.0, 10, 30, 100 or 300 mg) were administered to each group (n = 24 subjects per group). Platelet aggregation was assessed at baseline and then 15 and 30 min and 2, 5 and 24 h after drug administration. Determination of plasma concentrations of clopidogrel, clopidogrel carboxylic acid metabolite and the clopidogrel thiol metabolite were assessed at baseline and at 1, 5, 10, 20 and 30 min and 1, 2, 3, 4, 6, 8, 12 and 24 h after drug administration.

3. PM103 produced a rapid, persistent and dose‐related inhibition of platelet aggregation. The onset of the ant platelet effect paralleled the appearance in plasma of the clopidogrel thiol active metabolite. PM103 was well tolerated and no subjects discontinued treatment because of adverse events.

4. These data suggest that PM103 may be a suitable alternative to oral clopidogrel for patients in whom the desired clinical management would include administration of clopidogrel after coronary angiography but prior to percutaneous coronary intervention.
Delegation and Institutional Design in Health‐Care Rationing
Authors: LANDWEHR CLAUDIA , BÖHM KATHARINA
Published: September 2011

The delegation of decision‐making powers to nonmajoritarian, independent agencies has become a significant phenomenon in more and more policy areas. One of these is the health‐care sector, where decisions on the range of services covered within public systems have, in most developed countries, been delegated to specialized bodies. This article offers an analytical framework that seeks to grasp the empirical variety and complexity of delegative processes and appointed institutions. The framework is used to describe decision‐making processes and institutions in six countries: Austria, Germany, Norway, Sweden, New Zealand, and the United Kingdom. We find that, although constrained by preexisting institutional structures and traditions, delegators enjoy a considerable degree of discretion in their institutional design choices and engage in strategic design and redesign of appointed bodies.
What Drives Reforms in International Organizations? External Pressure and Bureaucratic Entrepreneurs in the UN Response to AIDS
Authors: NAY OLIVIER
Published: September 2011

This article explores organizational dynamics that go with the design and implementation of public administration reforms within the United Nations (UN) system. It focuses on management reforms carried out in the UNAIDS Programme, which brings together 10 UN agencies to combat the worldwide HIV/AIDS epidemic. The article suggests that understanding these reforms requires questioning the exposure of UN administrations to pressures emanating from their environment and at the same time, investigating the intentions of bureaucratic entrepreneurs who promote and drive reforms within the UN system. The empirical development demonstrates that the swift incorporation of the external pressure into a reform process in the mid‐2000s cannot be dissociated from the active support of some UN agencies who have had a common interest in shifting institutional arrangements inside UNAIDS to expand their bureaucratic authority. In conclusion, the article suggests analyzing reforms within international administrations as social processes driven by both coercion and opportunities.
Impact of Depressive Symptoms on Future Alcohol Use in Patients with Co‐Occurring Bipolar Disorder and Alcohol Dependence: A Prospective Analysis in an 8‐Week Randomized Controlled Trial of Acamprosate
Authors: Prisciandaro James J. , DeSantis Stacia M. , Chiuzan Cody , Brown Delisa G. , Brady Kathleen T. , Tolliver Bryan K.
Published: September 2011

Background:  Bipolar disorders and alcohol use disorders commonly co‐occur, yet little is known about the proximal impact of bipolar symptoms on alcohol use in patients with this comorbidity. The present study examined the impact of depressive symptoms and alcohol craving on proximal alcohol use in patients with co‐occurring bipolar disorder and alcohol dependence.

Methods:  Data were collected during an 8‐week randomized controlled trial of acamprosate for individuals with co‐occurring bipolar disorder and alcohol dependence (n = 30). Depressive symptoms and alcohol craving were assessed biweekly using the Montgomery Asberg Depression Rating Scale (MADRS) and the Obsessive Compulsive Drinking Scale (OCDS), respectively. Daily alcohol use data were available via administration of the Time‐line Follow‐back interview at baseline and at subsequent weekly study visits. Correlational analyses and hidden Markov modeling were used to examine the prospective relationships between depressive symptoms, alcohol craving, and alcohol use.

Results:  Depressive symptoms and alcohol craving were significantly correlated with proximal (i.e., 1 week later) alcohol use across a variety of alcohol consumption summary measures. In hidden Markov models, depressive symptoms (OR = 1.3, 95% credible interval = [1.1, 1.5]) and alcohol craving (OR = 1.6, 95% credible interval = [1.4, 1.9]) significantly predicted transitioning from a light to a heavy drinking state, or remaining in a heavy drinking state.

Conclusions:  The results from the present study suggest that depressive symptoms and alcohol craving increase proximal risk for alcohol use in individuals with co‐occurring bipolar and alcohol use disorders.
Biocomplexity in large tree mortality: interactions between elephant, fire and landscape in an African savanna
Authors: Vanak Abi Tamim , Shannon Graeme , Thaker Maria , Page Bruce , Grant Rina , Slotow Rob
Published: September 2011

The vegetation dynamics of the savanna ecosystem are driven by complex interactions between biotic and abiotic factors, and thus are expected to exhibit emergent properties of biocomplexity. We explore the relative importance of static and dynamic drivers in explaining the patterns of mortality of large trees in the Kruger National Park, South Africa. Data on large trees were collected from 22 transects in April 2006, and these transects were re‐sampled in November 2008. Of the 2546 individually‐identified trees that were re‐sampled, 290 (11.4%) died in the interim. We tested several competing hypotheses with varying levels of complexity, and found that mortality of large trees was affected mainly by both static (geophysical and landscape characteristics) and dynamic (elephant damage and fire) factors that were either additive or interactive in their effects. Elephant damage was the main predictor of tree mortality, but fire also played an important role depending on the landscape type. Other static variables such as position‐on‐slope, height below canopy, and altitude had weak effects in explaining tree mortality. These results indicate that keystone features such as large trees, show differential vulnerability to mortality that is landscape‐specific. For conservation managers, this implies that the dynamic drivers (elephant and fire) of tree mortality have to be managed at the specific landscape‐level. We suggest that this emergent biocomplexity in the spatial and temporal patterns of large tree mortality is not unique to the African savannas, but is likely widespread across heterogeneous landscapes.
An Introduction to the Implant Crown with an Esthetic Adhesive Margin (ICEAM)
Authors: WADHWANI CHANDUR P. K. , PIÑEYRO ALFONSO , AKIMOTO KEN
Published: September 2011

This article describes a novel technique with the addition of a pressed porcelain abutment margin capable of bonding to the porcelain margin of an implant crown restoration. This allows for supragingival margin placement, reduces the potential effect of excess cement‐induced peri‐implant disease, and provides a controlled environment for the bonding process. Another advantage is the matching esthetics of the crown and supporting abutment, which in the event gingival recession occurs, the restoration appears as a longer tooth without the risk of exposing an underlying abutment margin with different esthetic properties.

CLINICAL SIGNIFICANCE

The transition margin from an implant abutment to a crown is challenging to manage especially esthetically. Placing the abutment margin in a subgingival position helps hide the unesthetic transition, however, this reduces the ability to clean excess cement, increases the risk of peri‐implant disease and the inability to control gingival sulcular fluids may affect the cement bond. The implant crown with an esthetic adhesive margin provides for supragingival bonded margins that can aid in complete removal of excess cement at the same time providing an esthetically pleasing result.

(J Esthet Restor Dent 24:246–254, 2012)
Tip60 regulates myoblast differentiation by enhancing the transcriptional activity of MyoD via their physical interactions
Authors: Kim Jung‐Woong , Jang Sang‐Min , Kim Chul‐Hong , An Joo‐Hee , Kang Eun‐Jin , Choi Kyung‐Hee
Published: September 2011

The progression of muscle differentiation is tightly controlled by multiple groups of transcription factors and transcriptional coregulators. MyoD is a transcription factor of the myogenic basic helix–loop–helix family required for the process of muscle cell differentiation. We now show that Tip60 is required for myoblast differentiation via enhancement of the transcriptional activity of MyoD. Knockdown of Tip60 in C2C12 cells leads to a lack of ability to switch from proliferating myoblasts to differentiated myotubes. Ectopic expression of Tip60 increased MyoD‐mediated luciferase activity on the myogenic regulatory gene, myogenin. We also found that Tip60 physically interacts with MyoD using its chromo‐ and Zn‐finger‐containing region, and that these protein interactions were required for the effective transcriptional activation of MyoD. Furthermore, a chromatin immunoprecipitation assay revealed that Tip60 recruits MyoD on the myogenin promoter, and Tip60 also increases the levels of acetylated histones H3 and H4 during myogenic differentiation. Taken together, these findings suggest that Tip60 is an important co‐activator for MyoD‐mediated myogenesis in mouse myoblast C2C12 cells.

Structured digital abstract

 TIP60 binds to MyoD by pull down (View interaction)

 TIP60 physically interacts with MyoD by anti tag coimmunoprecipitation (View interaction)

 TIP60 and MyoD colocalize by fluorescence microscopy (View interaction)

 MyoD physically interacts with TIP60 by  anti tag coimmunoprecipitation (View Interaction 1, 2)
Productivity Is a Poor Predictor of Plant Species Richness
Authors: Adler Peter B. , Seabloom Eric W. , Borer Elizabeth T. , Hillebrand Helmut , Hautier Yann , Hector Andy , Harpole W. Stanley , O’Halloran Lydia R. , Grace James B. , Anderson T. Michael , Bakker Jonathan D. , Biederman Lori A. , Brown Cynthia S. , Buckley Yvonne M. , Calabrese Laura B. , Chu Cheng-Jin , Cleland Elsa E. , Collins Scott L. , Cottingham Kathryn L. , Crawley Michael J. , Damschen Ellen I. , Davies Kendi F. , DeCrappeo Nicole M. , Fay Philip A. , Firn Jennifer , Frater Paul , Gasarch Eve I. , Gruner Daniel S. , Hagenah Nicole , Hille Ris Lambers Janneke , Humphries Hope , Jin Virginia L. , Kay Adam D. , Kirkman Kevin P. , Klein Julia A. , Knops Johannes M. H. , La Pierre Kimberly J. , Lambrinos John G. , Li Wei , MacDougall Andrew S. , McCulley Rebecca L. , Melbourne Brett A. , Mitchell Charles E. , Moore Joslin L. , Morgan John W. , Mortensen Brent , Orrock John L. , Prober Suzanne M. , Pyke David A. , Risch Anita C. , Schuetz Martin , Smith Melinda D. , Stevens Carly J. , Sullivan Lauren L. , Wang Gang , Wragg Peter D. , Wright Justin P. , Yang Louie H.
Published: September 2011

Standardized sampling from many sites worldwide was used to address an important ecological problem.
African Wild Ungulates Compete with or Facilitate Cattle Depending on Season
Authors: Odadi Wilfred O. , Karachi Moses K. , Abdulrazak Shaukat A. , Young Truman P.
Published: September 2011

Native wildlife enhance cattle performance during the wet season in a savanna landscape.
A Black Widow's Best Friend?
Authors: Rasio Frederic A.
Published: September 2011

Observations reveal an exotic planetary companion to a millisecond pulsar.
Three-Dimensional Structures of Soluble CD4-Bound States of Trimeric Simian Immunodeficiency Virus Envelope Glycoproteins Determined by Using Cryo-Electron Tomography
Authors: White Tommi A. , Bartesaghi Alberto , Borgnia Mario J. , de la Cruz M. Jason V. , Nandwani Rachna , Hoxie James A. , Bess Julian W. , Lifson Jeffrey D. , Milne Jacqueline L. S. , Subramaniam Sriram
Published: September 2011

The trimeric envelope glycoprotein (Env) spikes displayed on the surfaces of simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 (HIV-1) virions are composed of three heterodimers of the viral glycoproteins gp120 and gp41. Although binding of gp120 to cell surface CD4 and a chemokine receptor is known to elicit conformational changes in gp120 and gp41, changes in quaternary structure of the trimer have only recently been elucidated. For the HIV-1 BaL isolate, CD4 attachment results in a striking rearrangement of the trimer from a “closed” to an “open” conformation. The effect of CD4 on SIV trimers, however, has not been described. Using cryo-electron tomography, we have now determined molecular architectures of the soluble CD4 (sCD4)-bound states of SIV Env trimers for three different strains (SIVmneE11S, SIVmac239, and SIV CP-MAC). In marked contrast to HIV-1 BaL, SIVmneE11S and SIVmac239 Env showed only minor conformational changes following sCD4 binding. In SIV CP-MAC, where trimeric Env displays a constitutively “open” conformation similar to that seen for HIV-1 BaL Env in the sCD4-complexed state, we show that there are no significant further changes in conformation upon the binding of either sCD4 or 7D3 antibody. The density maps also show that 7D3 and 17b antibodies target epitopes on gp120 that are on opposites sides of the coreceptor binding site. These results provide new insights into the structural diversity of SIV Env and show that there are strain-dependent variations in the orientation of sCD4 bound to trimeric SIV Env.
Antigenic and Genetic Evolution of Equine Influenza A (H3N8) Virus from 1968 to 2007
Authors: Lewis N. S. , Daly J. M. , Russell C. A. , Horton D. L. , Skepner E. , Bryant N. A. , Burke D. F. , Rash A. S. , Wood J. L. N. , Chambers T. M. , Fouchier R. A. M. , Mumford J. A. , Elton D. M. , Smith D. J.
Published: September 2011

Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglutination inhibition (HI) assay. We have generated HI assay data for equine influenza A (H3N8) viruses isolated between 1968 and 2007 and have used antigenic cartography to quantify antigenic differences among the isolates. The antigenic evolution of equine influenza viruses during this period was clustered: from 1968 to 1988, all isolates formed a single antigenic cluster, which then split into two cocirculating clusters in 1989, and then a third cocirculating cluster appeared in 2003. Viruses from all three clusters were isolated in 2007. In one of the three clusters, we show evidence of antigenic drift away from the vaccine strain over time. We determined that a single amino acid substitution was likely responsible for the antigenic differences among clusters.
Hepatitis C Virus-Induced Cancer Stem Cell-Like Signatures in Cell Culture and Murine Tumor Xenografts
Authors: Ali Naushad , Allam Heba , May Randal , Sureban Sripathi M. , Bronze Michael S. , Bader Ted , Umar Shahid , Anant Srikant , Houchen Courtney W.
Published: September 2011

Hepatitis C virus (HCV) infection is a prominent risk factor for the development of hepatocellular carcinoma (HCC). Similar to most solid tumors, HCCs are believed to contain poorly differentiated cancer stem cell-like cells (CSCs) that initiate tumorigenesis and confer resistance to chemotherapy. In these studies, we demonstrate that the expression of an HCV subgenomic replicon in cultured cells results in the acquisition of CSC traits. These traits include enhanced expression of
d
oublecortin and
CaM
k
inase-
l
ike-1 (DCAMKL-1), Lgr5, CD133, α-fetoprotein, cytokeratin-19 (CK19), Lin28, and c-Myc. Conversely, curing of the replicon from these cells results in diminished expression of these factors. The putative stem cell marker DCAMKL-1 is also elevated in response to the overexpression of a cassette of pluripotency factors. The DCAMKL-1-positive cells isolated from hepatoma cell lines by fluorescence-activated cell sorting (FACS) form spheroids in Matrigel. The HCV RNA abundance and NS5B levels are significantly reduced by the small interfering RNA (siRNA)-led depletion of DCAMKL-1. We further demonstrate that HCV replicon-expressing cells initiate distinct tumor phenotypes compared to the tumors initiated by parent cells lacking the replicon. This HCV-induced phenotype is characterized by high-level expression/coexpression of DCAMKL-1, CK19, α-fetoprotein, and active c-Src. The results obtained by the analysis of liver tissues from HCV-positive patients and liver tissue microarrays reiterate these observations. In conclusion, chronic HCV infection appears to predispose cells toward the path of acquiring cancer stem cell-like traits by inducing DCAMKL-1 and hepatic progenitor and stem cell-related factors. DCAMKL-1 also represents a novel cellular target for combating HCV-induced hepatocarcinogenesis.
EGFR and KRAS quality assurance schemes in pathology: generating normative data for molecular predictive marker analysis in targeted therapy
Authors: Thunnissen Erik , Bovée Judith V M G , Bruinsma Hans , van den Brule Adriaan J C , Dinjens Winand , Heideman Daniëlle A M , Meulemans Els , Nederlof Petra , van Noesel Carel , Prinsen Clemens F M , Scheidel Karen , van de Ven Peter M , de Weger Roel , Schuuring Ed , Ligtenberg Marjolijn
Published: September 2011

Introduction

The aim of this study was to compare the reproducibility of epidermal growth factor receptor (EGFR) immunohistochemistry (IHC),EGFRgene amplification analysis, andEGFRandKRASmutation analysis among different laboratories performing routine diagnostic analyses in pathology in The Netherlands, and to generate normative data.

Methods

In 2008, IHC, in-situ hybridisation (ISH) forEGFR, and mutation analysis forEGFRandKRASwere tested. Tissue microarray sections were distributed for IHC and ISH, and tissue sections and isolated DNA with known mutations were distributed for mutation analysis. In 2009, ISH and mutation analysis were evaluated. False-negative and false-positive results were defined as different from the consensus, and sensitivity and specificity were estimated.

Results

In 2008, eight laboratories participated in the IHC ring study. In only 4/17 cases (23%) a consensus score of ≥75% was reached, indicating that this analysis was not sufficiently reliable to be applied in clinical practice. ForEGFRISH, andEGFRandKRASmutation analysis, an interpretable result (success rate) was obtained in ≥97% of the cases, with mean sensitivity ≥96% and specificity ≥95%. For small sample proficiency testing, a norm was established defining outlier laboratories with unsatisfactory performance.

Conclusions

The result of EGFR IHC is not a suitable criterion for reliably selecting patients for anti-EGFR treatment. In contrast, molecular diagnostic methods forEGFRandKRASmutation detection andEGFRISH may be reliably performed with high accuracy, allowing treatment decisions for lung cancer.
Replacement of conventional HIV testing with rapid testing: mathematical modelling to predict the impact on further HIV transmission between men
Authors: Wilson David P , Fairley Christopher K , Sankar Daniel , Williams Henrietta , Keen Phillip , Read Tim R H , Chen Marcus Y
Published: September 2011

Background

Rapid HIV testing is not permitted in Australia at the point of care. The authors evaluate the expected net effect of rapid HIV testing compared with standard serology diagnostic tests in terms of onward HIV transmission.

Methods

The authors used data for 174 men who had sex with men testing HIV-positive at the Melbourne Sexual Health Centre, Australia, in an agent-based mathematical model. Time of diagnosis is simulated according to conventional enzyme immunoassays or rapid HIV tests, with different window periods. The authors calculated the expected number of additional/averted transmissions due to missed or earlier diagnoses.

Results

Fourth generation rapid tests were simulated to miss ∼2–3% of diagnoses compared with conventional fourth generation enzyme immunoassay tests. However, in the remaining 97–98% of cases the rapid test would result in earlier detection of HIV. Overall, the rapid test would reduce time to patients receiving results by a median of ∼12 days. Assuming no changes in testing rates, the introduction of rapid testing diagnostic technologies would prevent one in every 2000–5000 HIV transmissions compared with the conventional diagnostic test.

Conclusions

Rapid tests would have a marginal benefit in reducing HIV transmission between men compared with conventional tests under assumptions of no changes in testing frequencies.
ON THE SUPPRESSION OF THE $n\bar{n}$ TRANSITIONS IN MEDIUM
Authors: NAZARUK V. I.
Published: September 2011

The model of [Formula: see text] transitions in the medium based on field-theoretical approach is considered. The time-dependence and corrections to the model are studied. The lower limit on the free-space [Formula: see text] oscillation time τ is in the range 1016 yr >τ>1.2×109 s .
n-Channel Organic Thin-Film Transistors based on Naphthalene–Bis(dicarboximide) Polymer for Organic Transistor Memory Using Hole-Acceptor Layer
Authors: Mohamad Khairul Anuar , Yousuke Kakuta , Uesugi Katsuhiro , Fukuda Hisashi
Published: September 2011

An investigation of threshold voltage shifts in organic thin-film transistors (OTFTs) based on poly[N,N '-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene) [P(NDI2OD-T2)] with additional poly(3-hexylthiophene) (P3HT) films on a poly(methyl methacrylate) (PMMA) organic dielectric layer is reported. With a top source-drain contact structure, the device exhibited a unipolar property with n-channel characteristics similar to those of the P(NDI2OD-T2)-only device. Furthermore, the existence of P3HT films as hole acceptor-like storage layers resulted in reversible V
th shift upon the application of external gate bias (V
bias) for a certain bias time (T
bias). Hence, the P(NDI2OD-T2)/P3HT-OTFTs exhibited a large memory window (ΔV
th = 10.7 V) for write and erase electrically without major degradation in saturation mobility [µsat = (1.8–2.8) ×10-4 cm2 V-1 s-1]. These results clearly indicate the utility of the naphthalene–bis(dicarboximide) (NDI)-based polymer–hole acceptor layer in the development of n-channel organic transistor memories.
Charge Collection Process of a Liquid-Phase Epitaxially Grown InSb Detector
Authors: Sato Yuki , Watanabe Kenichi , Yamazaki Atsushi , Kanno Ikuo
Published: September 2011

The energy spectra of the gamma rays emitted by 241Am, 133Ba, and 137Cs were measured using an InSb detector made from a liquid-phase epitaxially (LPE) grown crystal. To understand the relationship between the maximum channel numbers of energy spectra and the maximum energies of gamma rays, a charge collection process is discussed. We performed numerical simulations of the charge collection process with a modified Hecht's equation. We showed that the entire LPE-InSb crystal including outside the depletion layer worked as a sensitive volume.
Self-Aligned Top-Gate Oxide Thin-Film Transistor Formed by Aluminum Reaction Method
Authors: Morosawa Narihiro , Ohshima Yoshihiro , Morooka Mitsuo , Arai Toshiaki , Sasaoka Tatsuya
Published: September 2011

We developed a novel highly reliable self-aligned top-gate oxide semiconductor thin-film transistor (TFT) formed by the aluminum (Al) reaction method. In this method, Al diffusion into the oxide semiconductor was observed. The low sheet resistivity of the source/drain regions was attributed to Al working as a donor in the oxide semiconductor. The TFTs with 4 µm channel length exhibited a field-effect mobility of 9.8 cm2 V-1 s-1, a threshold voltage of -1.5 V, and a subthreshold swing of 0.22 V/decade. Highly reliable TFTs were obtained after 300 °C annealing without increasing the sheet resistivity of source/drain regions.