Spin-chain model of a many-body quantum battery

Recently, it has been shown that energy can be deposited on a collection of quantum systems at a rate that scales super-extensively. Some of these schemes for `quantum batteries' rely on the use of global many-body interactions that take the batteries through a correlated short cut in state space. Here, we extend the notion of a quantum battery from a collection of a priori isolated systems to a many-body quantum system with intrinsic interactions. Specifically, we consider a one-dimensional spin chain with physically realistic two-body interactions. We find that the spin-spin interactions can yield an advantage in charging power over the non-interacting case, and we demonstrate that this advantage can grow super-extensively when the interactions are long ranged. However, we show that, unlike in previous work, this advantage is a mean-field interaction effect that does not involve correlations and that relies on the interactions being intrinsic to the battery.Comment: 9 pages, 6 figure

Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell

PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Mycobacterium tuberculosis ClpP Proteases Are Co-transcribed but Exhibit Different Substrate Specificities

PMCID: PMC3613350This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Reduced preference for social rewards in a novel tablet based task in young children with Autism Spectrum Disorders

Atypical responsivity to social rewards has been observed in young children with or at risk of Autism Spectrum Disorders (ASD). These observations contributed to the hypothesis of reduced social motivation in ASD. In the current study we develop a novel task to test social reward preference using a tablet computer (iPad), where two differently coloured buttons were associated with a social and a nonsocial rewarding image respectively. 63 young children, aged 14–68 months, with and without a diagnosis of ASD took part in the study. The experimental sessions were also recorded on video, using an in-built webcam on the tablet as well as an external camera. Children with ASD were found to show a reduced relative preference for social rewards, indexed by a lower proportion of touches for the button associated with the social reward image. Greater social preference as measured using the tablet-based task was associated with increased use of social communicative behaviour such as eye contact with the experimenter and social smile in response to the social reward image. These results are consistent with earlier findings from eye-tracking studies, and provide novel empirical insights into atypical social reward responsivity in ASD

More stories on Th17 cells

For more than two decades, immunologists have been using the so-called Th1/Th2 paradigm to explain most of the phenomena related to adaptive immunity. the Th1/Th2 paradigm implied the existence of two different, mutually regulated, CD4(+) T helper subsets: Th1 cells, driving cell-mediated immune responses involved in tissue damage and fighting infection against intracellular parasites; and Th2 cells that mediate IgE production and are particularly involved in eosinophilic inflammation, allergy and clearance of helminthic infections. A third member of the T helper set, IL-17-producing CD4(+) T cells, now called Th17 cells, was recently described as a distinct lineage that does not share developmental pathways with either Th1 or Th2 cells. the Th17 subset has been linked to autoimmune disorders, being able to produce IL-17, IL-17F and IL-21 among other inflammatory cytokines. Interestingly, it has been reported that there is not only a cross-regulation among Th1, Th2 and Th17 effector cells but there is also a dichotomy in the generation of Th17 and T regulatory cells. Therefore, Treg and Th17 effector cells arise in a mutually exclusive fashion, depending on whether they are activated in the presence of TGF-beta or TGF-beta plus inflammatory cytokines such as IL-6. This review will address the discovery of the Th17 cells, and recent progress on their development and regulation.Crohn's and Colitis Foundation of AmericaNIHLa Jolla Inst Allergy & Immunol, La Jolla, CA 92037 USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilNIH: RO1 AI050265-06Web of Scienc

Denial of long-term issues with agriculture on tropical peatlands will have devastating consequences

Letter to the Editor

Heparan sulfate proteoglycans: structure, protein interactions and cell signaling

Heparan sulfate proteoglycans are ubiquitously found at the cell surface and extracellular matrix in all the animal species. This review will focus on the structural characteristics of the heparan sulfate proteoglycans related to protein interactions leading to cell signaling. The heparan sulfate chains due to their vast structural diversity are able to bind and interact with a wide variety of proteins, such as growth factors, chemokines, morphogens, extracellular matrix components, enzymes, among others. There is a specificity directing the interactions of heparan sulfates and target proteins, regarding both the fine structure of the polysaccharide chain as well precise protein motifs. Heparan sulfates play a role in cellular signaling either as receptor or co-receptor for different ligands, and the activation of downstream pathways is related to phosphorylation of different cytosolic proteins either directly or involving cytoskeleton interactions leading to gene regulation. The role of the heparan sulfate proteoglycans in cellular signaling and endocytic uptake pathways is also discussed.Proteoglicanos de heparam sulfato são encontrados tanto superfície celular quanto na matriz extracelular em todas as espécies animais. Esta revisão tem enfoque nas características estruturais dos proteoglicanos de heparam sulfato e nas interações destes proteoglicanos com proteínas que levam à sinalização celular. As cadeias de heparam sulfato, devido a sua variedade estrutural, são capazes de se ligar e interagir com ampla gama de proteínas, como fatores de crescimento, quimiocinas, morfógenos, componentes da matriz extracelular, enzimas, entreoutros. Existe uma especificidade estrutural que direciona as interações dos heparam sulfatos e proteínas alvo. Esta especificidade está relacionada com a estrutura da cadeia do polissacarídeo e os motivos conservados da cadeia polipeptídica das proteínas envolvidas nesta interação. Os heparam sulfatos possuem papel na sinalização celular como receptores ou coreceptores para diferentes ligantes. Esta ligação dispara vias de sinalização celular levam à fosforilação de diversas proteínas citosólicas ou com ou sem interações diretas com o citoesqueleto, culminando na regulação gênica. O papel dos proteoglicanos de heparam sulfato na sinalização celular e vias de captação endocítica também são discutidas nesta revisão.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Departamento de BioquímicaUniversidade Federal de São Paulo (UNIFESP) Departamento de OftalmologiaUNIFESP, Depto. de BioquímicaUNIFESP, Depto. de OftalmologiaSciEL

Population Pharmacokinetic and Pharmacodynamic Modeling for Assessing Risk of Bisphosphonate-related Osteonecrosis of the Jaw

Objective: We hypothesized that patients with bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) accumulate higher levels of BP in bone than those without BRONJ. Study Design: Using the Pmetrics package and published data, we designed a population pharmacokinetic model of pamidronate concentration in plasma and bone and derived a toxic bone BP threshold of 0.2 mmol/L. With the model, and using patient individual BP duration and bone mineral content estimated from lean body weight, we calculated bone BP levels in 153 subjects. Results: Mean bone BP in 69 BRONJ cases was higher than in 84 controls (0.20 vs 0.10 mmol/L, P \u3c 0.001), consistent with the toxic bone threshold of 0.2 mmol/L. BRONJ was also associated with longer duration BP therapy (5.3 vs 2.7 years, P \u3c 0.001), older age (76 vs 70 years, P \u3c 0.001), and Asian race (49% vs 14%, P \u3c 0.001). Conclusions: Our model accurately discriminated BRONJ cases from controls among patients on BP therapy. © 2013 Elsevier Inc