Estimate of the cutoff errors in the Ewald summation for dipolar systems

Theoretical estimates for the cutoff errors in the Ewald summation method for dipolar systems are derived. Absolute errors in the total energy, forces and torques, both for the real and reciprocal space parts, are considered. The applicability of the estimates is tested and confirmed in several numerical examples. We demonstrate that these estimates can be used easily in determining the optimal parameters of the dipolar Ewald summation in the sense that they minimize the computation time for a predefined, user set, accuracy.

Social communication deficits: specific associations with Social Anxiety Disorder

Background Social communication deficits are prevalent amongst children with anxiety disorders; however whether they are over-represented specifically among children with Social Anxiety Disorder has not been examined. This study set out to examine social communication deficits among children with Social Anxiety Disorder in comparison to children with other forms of anxiety disorder. Methods Parents of 404 children with a diagnosed anxiety disorder completed the Social Communication Questionnaire (SCQ; Rutter, M., Bailey, A., Lord, C., 2003. The Social Communication Questionnaire – Manual. Western Psychological Services, Los Angeles, CA). Children with a diagnosis of Social Anxiety Disorder (n=262) and anxious children without Social Anxiety Disorder (n=142) were compared on SCQ total and subscale scores and the frequency of participants scoring above clinical cut-offs. Results Children with Social Anxiety Disorder scored significantly higher than anxious children without Social Anxiety Disorder on the SCQ total (t(352)=4.85, p<.001, d=.55, r=.27), Reciprocal Social Interaction (t(351)=4.73, p<.001, d=.55, r=.27), communication (t(344)=3.62, p<.001, d=.43, r=.21) and repetitive, restrictive and stereotyped behaviors subscales (t(353)=3.15, p=.002, d=.37, r=.18). Furthermore, children with Social Anxiety Disorder were three times more likely to score above clinical cut-offs. Limitations The participants were a relatively affluent group of predominantly non-minority status. The social communication difficulties measure relied on parental report which could be influenced by extraneous factors. Conclusions Treatments for Social Anxiety Disorder may benefit from a specific focus on developing social communication skills. Future research using objective assessments of underlying social communication skills is required.

RE1 silencing transcription factor/neuron-restrictive silencing factor regulates expansion of adult mouse subventricular zone-derived neural stem/progenitor cells in vitro

Adult neural stem cell (aNSC) activity is tuned by external stimuli through the recruitment of transcription factors. This study examines the RE1 silencing transcription factor (REST) in neural stem/progenitor cells isolated from the subventricular zone of adult mouse brain and provides the first extensive characterization of REST-mediated control of the cellular and molecular properties. This study shows that REST knockdown affects the capacity of progenitor cells to generate neurospheres, reduces cell proliferation, and triggers cell differentiation despite the presence of growth factors. Genome- and transcriptome-wide analyses show that REST binding sites are significantly enriched in genes associated with synaptic transmission and nervous system development and function. Seeking candidate regulators of aNSC function, this study identifies a member of the bone morphogenetic protein (BMP) family, BMP6, the mRNA and protein of which increased after REST knockdown. The results of this study extend previous findings, demonstrating a reciprocal control of REST expression by BMPs. Administration of exogenous BMP6 inhibits aNSC proliferation and induces the expression of the astrocytic marker glial fibrillary acidic protein, highlighting its antimitogenic and prodifferentiative effects. This study suggests that BMP6 produced in a REST-regulated manner together with other signals can contribute to regulation of NSC maintenance and fate. © 2015 Wiley Periodicals, Inc.

Apples and cardiovascular health: is the gut microbiota a core consideration?

There is now considerable scientific evidence that a diet rich in fruits and vegetables can improve human health and protect against chronic diseases. However, it is not clear whether different fruits and vegetables have distinct beneficial effects. Apples are among the most frequently consumed fruits and a rich source of polyphenols and fiber. A major proportion of the bioactive components in apples, including the high molecular weight polyphenols, escape absorption in the upper gastrointestinal tract and reach the large intestine relatively intact. There, they can be converted by the colonic microbiota to bioavailable and biologically active compounds with systemic effects, in addition to modulating microbial composition. Epidemiological studies have identified associations between frequent apple consumption and reduced risk of chronic diseases such as cardiovascular disease. Human and animal intervention studies demonstrate beneficial effects on lipid metabolism, vascular function and inflammation but only a few studies have attempted to link these mechanistically with the gut microbiota. This review will focus on the reciprocal interaction between apple components and the gut microbiota, the potential link to cardiovascular health and the possible mechanisms of action.

Differential roles of the PKC novel isoforms, PKCδ and PKCε, in mouse and human platelets

Background Increasing evidence suggests that individual isoforms of protein kinase C (PKC) play distinct roles in regulating platelet activation. Methodology/Principal Findings In this study, we focus on the role of two novel PKC isoforms, PKCδ and PKCε, in both mouse and human platelets. PKCδ is robustly expressed in human platelets and undergoes transient tyrosine phosphorylation upon stimulation by thrombin or the collagen receptor, GPVI, which becomes sustained in the presence of the pan-PKC inhibitor, Ro 31-8220. In mouse platelets, however, PKCδ undergoes sustained tyrosine phosphorylation upon activation. In contrast the related isoform, PKCε, is expressed at high levels in mouse but not human platelets. There is a marked inhibition in aggregation and dense granule secretion to low concentrations of GPVI agonists in mouse platelets lacking PKCε in contrast to a minor inhibition in response to G protein-coupled receptor agonists. This reduction is mediated by inhibition of tyrosine phosphorylation of the FcRγ-chain and downstream proteins, an effect also observed in wild-type mouse platelets in the presence of a PKC inhibitor. Conclusions These results demonstrate a reciprocal relationship in levels of the novel PKC isoforms δ and ε in human and mouse platelets and a selective role for PKCε in signalling through GPVI.

Don’t aim too high for your kids: parental over-aspiration undermines students’ learning in mathematics

Previous research has suggested that parents’ aspirations for their children’s academic attainment can have a positive influence on children’s actual academic performance. Possible negative effects of parental over-aspiration, however, have found little attention in the psychological literature. Employing a dual-change score model with longitudinal data from a representative sample of German schoolchildren and their parents (N = 3,530; grades 5 to 10), we showed that parental aspiration and children’s mathematical achievement were linked by positive reciprocal relations over time. Importantly, we also found that parental aspiration that exceeded their expectation (i.e., over-aspiration) had negative reciprocal relations with children’s mathematical achievement. These results were fairly robust after controlling for a variety of demographic and cognitive variables such as children’s gender, age, intelligence, school type, and family SES. The results were also replicated with an independent sample of US parents and their children. These findings suggest that unrealistically high parental aspiration can be detrimental for children’s achievement.

The Phantom Carriage (1921)

The reputation of The Phantom Carriage (Körkarlen) as one of the major films of Swedish silent cinema is in some respects securely established. Yet the film has attracted surprisingly little detailed discussion. It may be that its most striking stylistic features have deflected or discouraged closer scrutiny. Tom Gunning, for instance, in making the case for Sjöström’s Masterman, argues that ‘Körkarlen wears its technique on its sleeve, overtly displays its unquestionable mastery of superimposition and complex narrative structure. Mästerman tucks its mastery of editing and composition up its sleeve, so to speak’. This article makes an argument for a different evaluation of The Phantom Carriage, bringing a critical and interpretative understanding of the film’s style into conversation with the historical accounts of film form which predominate in the scholarship around silent cinema. It suggests that the film achieves ‘mastery of editing and composition’ with a flexibility and fluidity in the construction of dramatic space that is in itself remarkable for its period, but that Sjöström’s achievements extend well beyond his handling of film space. Specifically, it discusses a segment which is in several respects at the heart of the film: the first meeting between the two central characters, David Holm (Victor Sjöström) and Sister Edit (Astrid Holm); it spans the film’s exact mid-point; and at almost twelve and a half minutes it is the longest uninterrupted passage to take place in a single setting. The chapter argues that the dramatic and structural centrality of the hostel segment is paralleled by its remarkably rich articulation of the relationships between action, character and space. We show how Sjöström’s creation of a three-dimensional filmic space - with no hint of frontality - becomes the basis for a reciprocal relationship between spatial naturalism and performance style, and for a mise-en-scene that can take on discrete interpretive force. The argument also places the hostel sequences within the film as a whole in order to show how relationships articulated through the detailed decisions in this section take on their full resonance within patterns and motifs that develop across the film.

Collabowrighting the hyper(play)text: a postdramatic digital poetics

The aim of this research is to exhibit how literary playtexts can evoke multisensory trends prevalent in 21st century theatre. In order to do so, it explores a range of practical forms and theoretical contexts for creating participatory, site-specific and immersive theatre. With reference to literary theory, specifically to semiotics, reader-response theory, postmodernism and deconstruction, it attempts to revise dramatic theory established by Aristotle’s Poetics. Considering Gertrude Stein’s essay, Plays (1935), and relevant trends in theatre and performance, shaped by space, technology and the everchanging role of the audience member, a postdramatic poetics emerges from which to analyze the plays of Mac Wellman and Suzan-Lori Parks. Distinguishing the two textual lives of a play as the performance playtext and the literary playtext, it examines the conventions of the printed literary playtext, with reference to models of practice that radicalize the play form, including works by Mabou Mines, The Living Theatre and Fiona Templeton. The arguments of this practice-led Ph.D. developed out of direct engagement with the practice project, which explores the multisensory potential of written language when combined with hypermedia. The written thesis traces the development process of a new play, Rumi High, which is presented digitally as a ‘hyper(play)text,’ accessible through the Internet at www.RumiHigh.org. Here, ‘playwrighting’ practice is expanded spatially, collaboratively and textually. Plays are built, designed and crafted with many layers of meaning that explore both linguistic and graphic modes of poetic expression. The hyper(play)text of Rumi High establishes playwrighting practice as curatorial, where performance and literary playtexts are in a reciprocal relationship. This thesis argues that digital writing and reading spaces enable new approaches to expressing the many languages of performance, while expanding the collaborative network that produces the work. It questions how participatory forms of immersive and site-specific theatre can be presented as interactive literary playtexts, which enable the reader to have a multisensory experience. Through a reflection on process and an evaluation of the practice project, this thesis problematizes notions of authorship and text.

Breaking the double-edged sword of effort/trying hard: developmental equilibrium and Longitudinal relations among effort, achievement, and academic self-concept

Ever since the classic research of Nicholls (1976) and others, effort has been recognized as a double-edged sword: whilst it might enhance achievement, it undermines academic self-concept (ASC). However, there has not been a thorough evaluation of the longitudinal reciprocal effects of effort, ASC and achievement,in the context of modern self-concept theory and statistical methodology. Nor have there been developmental equilibrium tests of whether these effects are consistent across the potentially volatile early-to-middle adolescence. Hence, focusing on mathematics, we evaluate reciprocal effects models over the first four years of secondary school, relating effort, achievement (test scores and school grades), ASC, and ASCxEffort interactions for a representative sample of 3,421 German students (Mn age = 11.75 years at Wave 1). ASC, effort and achievement were positively correlated at each wave, and there was a clear pattern of positive reciprocal positive effects among ASC, test scores and school grades—each contributing to the other, after controlling for the prior effects of all others. There was an asymmetrical pattern of effects for effort that is consistent with the double-edged sword premise: prior school grades had positive effects on subsequent effort, but prior effort had non-significant or negative effects on subsequent grades and ASC. However, on the basis of a synergistic application of new theory and methodology, we predicted and found a significant ASC-by-effort interaction, such that prior effort had more positive effects on subsequent ASC and school grades when prior ASC was high—thus providing a key to breaking the double-edged sword.

Relative effect of litter quality, forest type and their interaction on leaf decomposition in south-east Brazilian forests

Decomposition was studied in a reciprocal litter transplant experiment to examine the effects of forest type, litter quality and their interaction on leaf decomposition in four tropical forests in south-east Brazil. Litterbags were used to measure decomposition of leaves of one tree species from each forest type: Calophyllum brasiliense from restinga forest; Guapira opposita from Atlantic forest; Esenbeckia leiocarpa from semi-deciduous forest; and Copaifera langsdorffii from cerradao. Decomposition rates in rain forests (Atlantic and restinga) were twice as fast as those in seasonal forests (semi-deciduous and cerradao), suggesting that intensity and distribution of precipitation are important predictors of decomposition rates at regional scales. Decomposition rates varied by species, in the following order: E. leiocarpa > C. langsdorffii > G. opposita > C. brasiliense. However, there was no correlation between decomposition rates and chemical litter quality parameters: C:N, C:P, lignin concentration and lignin:N. The interaction between forest type and litter quality was positive mainly because C. langsdorffii decomposed faster than expected in its native forest. This is a potential indication of a decomposer`s adaptation to specific substrates in a tropical forest. These findings suggest that besides climate, interactions between decomposers and plants might play an essential role in decomposition processes and it must be better understood.

Non-homologous sex chromosomes in two species of the genus Eigenmannia (Teleostei : Gymnotiformes)

The Neotropical genus Eigenmannia is a fish group with unknown species diversity where representatives possess a broad range of chromosomal sex determining systems namely XY/XX, X1X2Y/X1X1X2X2, ZZ/ZW as well as homomorphic sex chromosomes. To test the homology of two heteromorphic XY sex chromosome systems present in two sympatric populations, reciprocal cross-species FISH experiments were performed using probes derived by microdissection of X and Y chromosomes present in analyzed specimens of Eigenmannia virescens and Eigenmannia sp.2, respectively. While X and Y paint probes hybridized to species-specific sex chromosomes, in reciprocal cross-FISH both probes hybridized exclusively to autosomes. The result suggests multiple independent origins of the XY systems in the analyzed populations. Copyright (C) 2008 S. Karger AG, Basel.

Deiodinase-mediated thyroid hormone inactivation minimizes thyroid hormone signaling in the early development of fetal skeleton

Thyroid hormone (TH) plays a key role on post-natal bone development and metabolism, while its relevance during fetal bone development is uncertain. To Study this, pregnant once were made hypothyroid and fetuses harvested at embryonic days (E) 12.5, 14.5, 16.5 and 18.5. Despite a marked reduction in fetal tissue concentration of both T4 and T3, bone development, as assessed at the distal epiphyseal growth plate of the femur and vertebra, was largely preserved Lip to E16.5. Only at E18.5, the hypothyroid fetuses exhibited a reduction in femoral type I and type X collagen and osteocalcin mRNA levels, in the length and area of the proliferative and hypertrophic zones, in the number of chondrocytes per proliferative column, and in the number of hypertrophic chondrocyres, in addition to a slight delay in endochondral and intramembranous ossification. This Suggests that LIP to E 16.5, thyroid hormone signaling in bone is kept to a minimum. In fact, measuring the expression level of the activating and inactivating iodothyronine deiodinases (D2 and D3) helped understand how this is achieved. D3 mRNA was readily detected as early as E14.5 and its expression decreased markedly (similar to 10-fold) at E18.5, and even more at 14 days after birth (P14). In contrast. D2 mRNA expression increased significantly by E18.5 and markedly (similar to 2.5-fold) by P14. The reciprocal expression levels of D2 and D3 genes during early bone development along with the absence of a hypothyroidism-induced bone phenotype at this time Suggest that coordinated reciprocal deiodinase expression keeps thyroid hormone signaling in bone to very low levels at this early stage of bone development. (c) 2008 Elsevier Inc. All rights reserved.

Growth and Melting of Metallic Nanoclusters in Glass: A Review of Recent Investigations

The mechanisms of nucleation and growth and the solid-to-liquid transition of metallic nanoclusters embedded in sodium borate glass were recently studied in situ via small-angle X-ray scattering (SAXS) and wide-an-le X-ray scattering (WAXS). SAXS results indicate that, under isothermal annealing conditions, the formation and growth of Bi or Ag nanoclusters embedded in sodium borate glass occurs through two successive stages after a short incubation period. The first stage is characterized by the nucleation and growth of spherical metal clusters promoted by the diffusion of Bi or Ag atoms through the initially supersaturated glass phase. The second stage is named the coarsening stage and occurs when the (Bi- or Ag-) doping level of the vitreous matrix is close to the equilibrium value. The experimental results demonstrated that, at advanced stages of the growth process, the time dependence of the average radius and density number of the clusters is in agreement with the classical Lifshitz-Slyozov-Waoner (LSW) theory. However, the radius distribution function is better described by a lognormal function than by the function derived from the theoretical LSW model. From the results of SAXS measurements at different temperatures, the activation energies for the diffusion of Ag and Bi through sodium borate glass were determined. In addition, via combination of the results of simultaneous WAXS and SAXS measurements at different temperatures, the crystallographic structure and the dependence of melting temperature T(m) on crystal radius R of Bi nanocrystals were established. The experimental results indicate that T(m) is a linear and decreasing function of nanocrystal reciprocal radius 1/R, in agreement with the Couchman and Jesser theoretical model. Finally, a weak contraction in the lattice parameters of Bi nanocrystals with respect to bulk crystals was established.

The Recombination Protein RAD52 Cooperates with the Excision Repair Protein OGG1 for the Repair of Oxidative Lesions in Mammalian Cells

Oxidized bases are common types of DNA modifications. Their accumulation in the genome is linked to aging and degenerative diseases. These modifications are commonly repaired by the base excision repair (BER) pathway. Oxoguanine DNA glycosylase (OGG1) initiates BER of oxidized purine bases. A small number of protein interactions have been identified for OGG1, while very few appear to have functional consequences. We report here that OGG1 interacts with the recombination protein RAD52 in vitro and in vivo. This interaction has reciprocal functional consequences as OGG1 inhibits RAD52 catalytic activities and RAD52 stimulates OGG1 incision activity, likely increasing its turnover rate. RAD52 colocalizes with OGG1 after oxidative stress to cultured cells, but not after the direct induction of double-strand breaks by ionizing radiation. Human cells depleted of RAD52 via small interfering RNA knockdown, and mouse cells lacking the protein via gene knockout showed increased sensitivity to oxidative stress. Moreover, cells depleted of RAD52 show higher accumulation of oxidized bases in their genome than cells with normal levels of RAD52. Our results indicate that RAD52 cooperates with OGG1 to repair oxidative DNA damage and enhances the cellular resistance to oxidative stress. Our observations suggest a coordinated action between these proteins that may be relevant when oxidative lesions positioned close to strand breaks impose a hindrance to RAD52 catalytic activities.

Fan Culture as an Informal Learning Environment : Presentation of a NGL project

Fan culture is a subculture that has developed explosively on the internet over the last decades. Fans are creating their own films, translations, fiction, fan art, blogs, role play and also various forms that are all based on familiar popular culture creations like TV-series, bestsellers, anime, manga stories and games. In our project, we analyze two of these subculture genres, fan fiction and scanlation. Amateurs, and sometimes professional writers, create new stories by adapting and developing existing storylines and characters from the original. In this way, a "network" of texts occurs, and writers step into an intertextual dialogue with established writers such as JK Rowling (Harry Potter) and Stephanie Meyer (Twilight). Literary reception and creation then merge into a rich reciprocal creative activity which includes comments and feedback from the participators in the community. The critical attitude of the fans regarding quality and the frustration at waiting for the official translation of manga books led to the development of scanlation, which is an amateur translation of manga distributed on the internet.  Today, young internet users get involved in conceptual discussions of intertextuality and narrative structures through fan activity. In the case of scanlation, the scanlators practice the skills and techniques of translating in an informal environment. This phenomenon of participatory culture has been observed by scholars and it is concluded that they contribute to the development of a student’s literacy and foreign language skills. Furthermore, there is no doubt that the fandom related to Japanese cultural products such as manga, anime and videogames is one of the strong motives for foreign students to start learning Japanese. This is something to take into pedagogical consideration when we develop web-based courses. Fan fiction and fan culture make it ​​possible to have an intensive transcultural dialogue between participators throughout the world and is of great interest when studying the interaction between formal and informal learning that puts the student in focus