2,927 research outputs found
Evo-devo of human adolescence: beyond disease models of early puberty
Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research
Immune-mediated mechanisms influencing the efficacy of anticancer therapies
Conventional anticancer therapies, such as chemotherapy, radiotherapy, and targeted therapy, are designed to kill cancer cells. However, the efficacy of anticancer therapies is not only determined by their direct effects on cancer cells but also by off-target effects within the host immune system. Cytotoxic treatment regimens elicit several changes in immune-related parameters including the composition, phenotype, and function of immune cells. Here we discuss the impact of innate and adaptive immune cells on the success of anticancer therapy. In this context we examine the opportunities to exploit host immune responses to boost tumor clearing, and highlight the challenges facing the treatment of advanced metastatic disease
Water-Gated Charge Doping of Graphene Induced by Mica Substrates
We report on the existence of water-gated charge doping of graphene deposited
on atomically flat mica substrates. Molecular films of water in units of ~0.4
nm-thick bilayers were found to be present in regions of the interface of
graphene/mica hetero-stacks prepared by micromechanical exfoliation of kish
graphite. The spectral variation of the G and 2D bands, as visualized by Raman
mapping, shows that mica substrates induce strong p-type doping in graphene,
with hole densities of {-2}$. The ultrathin water
films, however, effectively block interfacial charge transfer, rendering
graphene significantly less hole-doped. Scanning Kelvin probe microscopy
independently confirmed a water-gated modulation of the Fermi level by 0.35 eV,
in agreement with the optically determined hole density. The manipulation of
the electronic properties of graphene demonstrated in this study should serve
as a useful tool in realizing future graphene applications.Comment: 15 pages, 4 figures; Nano Letters, accepted (2012
Pre-clinical Activity of Targeting the PI3K/Akt/mTOR Pathway in Burkitt Lymphoma
Though outcomes for pediatric Burkitt lymphoma (BL) have improved significantly in recent decades with intensive multi-agent chemotherapy and the addition of rituximab, chemotherapy resistance remains a significant impediment to cure following relapse. Activation of the PI3K/AKT pathway has been implicated in Burkitt lymphomagenesis and increased PI3K/AKT activation has been associated with worse outcomes in adults with aggressive B-cell non-Hodgkin lymphoma (B-NHL). Inhibitors of the PI3K/AKT pathway have been approved for the treatment of refractory indolent B-NHL and continue to be investigated for treatment of aggressive B-NHLs. We investigated the activation of the PI3K/AKT pathway in a cell line model of resistant BL and the ability to target this pathway with small molecule inhibitors in BL cell lines. We found that cell lines resistant to rituximab and chemotherapy exhibited increased activation of PI3K/AKT and that inhibition of AKT or PI3K results in in vitro anti-lymphoma activity. To investigate the role of PI3K/AKT activation on the efficacy of cytotoxic chemotherapy, we exposed cells to inhibitors in combination with chemotherapy and noted a synergistic increase in response to chemotherapy. Overall these findings highlight the role of PI3K/AKT in chemotherapy resistance in BL cells and may represent a tractable therapeutic target
Adoption of RFID technologies in UK logistics: moderating roles of size, barcode experience and government support
Due to globalization, logistics has become an important part in the supply chain. Many logistics service providers have realised the importance of adoption of technologies that can help manufacturers, warehouses, and retailers to communicate with each other more efficiently. Among many logistics technologies, radio frequency identification (RFID) has been identified as an important technology to improve logistics operations and supply chain management, and thus is increasingly gaining both practitioners’ and researchers’ attention. The purpose of this study is to identify the impact of usability features of RFID in the adoption of the technology by the logistics sector in the UK. We have used questionnaire survey method to collect data from the UK logistics firms. The analysis of the data shows that the usability of RFID technology positively influences adoption of technology. We have further tested the moderating effects of firm size, experience with barcode use, and government support in adopting RFID. Our results show that government support strongly moderates the link between usability of RFID and its adoption but size and experience with barcode do not moderate this link. We elaborate the contributions of the study and managerial implications of our results in this pape
Homozygous MTAP deletion in primary human glioblastoma is not associated with elevation of methylthioadenosine.
Homozygous deletion of methylthioadenosine phosphorylase (MTAP) in cancers such as glioblastoma represents a potentially targetable vulnerability. Homozygous MTAP-deleted cell lines in culture show elevation of MTAP\u27s substrate metabolite, methylthioadenosine (MTA). High levels of MTA inhibit protein arginine methyltransferase 5 (PRMT5), which sensitizes MTAP-deleted cells to PRMT5 and methionine adenosyltransferase 2A (MAT2A) inhibition. While this concept has been extensively corroborated in vitro, the clinical relevance relies on exhibiting significant MTA accumulation in human glioblastoma. In this work, using comprehensive metabolomic profiling, we show that MTA secreted by MTAP-deleted cells in vitro results in high levels of extracellular MTA. We further demonstrate that homozygous MTAP-deleted primary glioblastoma tumors do not significantly accumulate MTA in vivo due to metabolism of MTA by MTAP-expressing stroma. These findings highlight metabolic discrepancies between in vitro models and primary human tumors that must be considered when developing strategies for precision therapies targeting glioblastoma with homozygous MTAP deletion
Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA
An investigation of the hadronic final state in diffractive and
non--diffractive deep--inelastic electron--proton scattering at HERA is
presented, where diffractive data are selected experimentally by demanding a
large gap in pseudo --rapidity around the proton remnant direction. The
transverse energy flow in the hadronic final state is evaluated using a set of
estimators which quantify topological properties. Using available Monte Carlo
QCD calculations, it is demonstrated that the final state in diffractive DIS
exhibits the features expected if the interaction is interpreted as the
scattering of an electron off a current quark with associated effects of
perturbative QCD. A model in which deep--inelastic diffraction is taken to be
the exchange of a pomeron with partonic structure is found to reproduce the
measurements well. Models for deep--inelastic scattering, in which a
sizeable diffractive contribution is present because of non--perturbative
effects in the production of the hadronic final state, reproduce the general
tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil
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