On the Validity and Applicability of Models of Negative Capacitance and Implications for MOS Applications

The observation of room temperature sub-60 mV/dec subthreshold slope (SS) in MOSFETs with ferroelectric (FE) layers in the gate stacks or in series with the gate has attracted much attention. Recently, we modeled this effect in the framework of a FE polarization switching model. However, there is a large amount of literature attributing this effect to a stabilization of quasi-static (QS) negative capacitance (NC) in the FE. The technological implications of a stabilized non-switching (NS) QSNC model vs a FE switching model are vastly different; the latter precluding applications to sub-60 mV/dec SS scaled CMOS due to speed limitations and power dissipated in switching. In this letter, we provide a thorough analysis assessing the foundations of models of QSNC, identifying which specific assumptions (ansatz) may be unlikely or unphysical, and analyzing their applicability. We show that it is not reasonable to expect QSNC for two separate capacitors connected in series (with a metal plate between dielectric (DE) and FE layers). We propose a model clarifying under which conditions a QS "apparent NC" for a FE layer in a FE-DE bi-layer stack may be observed, quantifying the requirements of strong interface polarization coupling in addition to capacitance matching. In this regime, our model suggests the FE layer does not behave as a NC layer, simply, the coupling leads to both the DE and FE behaving as high-k DE with similar permittivities. This may be useful for scaled EOT devices but does not lead to sub-60 mV/dec SS.Comment: Version published in Appl. Phys. Let

Gamma power in rural Pakistani children: links to executive function and verbal ability

Children in low- and middle-income countries are at high risk of cognitive deficits due to environmental deprivation that compromises brain development. Despite the high prevalence of unrealized cognitive potential, very little is known about neural correlates of cognition in this population. We assessed resting EEG power and cognitive ability in 105 highly disadvantaged 48-month-old children in rural Pakistan. An increase in EEG power in gamma frequency bands (21–30 Hz and 31–45 Hz) was associated with better executive function. For girls, EEG gamma power also related to higher verbal IQ. This study identifies EEG gamma power as a neural marker of cognitive function in disadvantaged children in low- and middle-income countries. Elevated gamma power may be a particularly important protective factor for girls, who may experience greater deprivation due to gender inequality.This research was supported by Grand Challenges Canada Saving Brains Initiative Grant 0061-03. The preparation of this article also was supported by a Scholar's Award from the William T. Grant Foundation to Jelena Obradovic. (0061-03 - Grand Challenges Canada Saving Brains Initiative; William T. Grant Foundation)Published versio

Que(e)r(y)ing gender-based assaults of trans-identifying people

Section A presents a systematic review of the empirical literature on dating violence (DV) among young trans and gender non-conforming (TGNC) people. The review synthesises what is known about the prevalence of DV among TGNC youth and their risk relative to cisgender peers; how relative DV risk compares to non-dating victimisation experiences, and the psychosocial/structural correlates of DV identified in this group. The literature is critically appraised, outlining some robust findings as well as significant methodological limitations. Synthesised findings are discussed and implications for research and practice are considered. Section B presents a grounded theory of barriers to help-seeking among trans survivors of sexual violence (SV). With reference to 10 themes, the model illustrates how psychosocial conditions (‘Navigating narratives of blame’; ‘Carrying lots of shame’; ‘Questioning my validity as a victim’; ‘Normalising sexual violence’; ‘Problematising felt gender’) combine with service-level interactions (‘Fearing the power of services’; ‘Being a curious object’; ‘Feeling unseen’) to inhibit support-seeking and maintain victimisation risk (‘Remaining vulnerable’; ‘Needing more from services’). The substantive theory suggests that help-seeking is compromised by trans identity being cyclically undermined and/or overemphasised in its relationship to SV. The model is discussed with reference to existing theories of help-seeking and minority experience, with clinical/policy implications considere

Cosmic string parameter constraints and model analysis using small scale Cosmic Microwave Background data

We present a significant update of the constraints on the Abelian Higgs cosmic string tension by cosmic microwave background (CMB) data, enabled both by the use of new high-resolution CMB data from suborbital experiments as well as the latest results of the WMAP satellite, and by improved predictions for the impact of Abelian Higgs cosmic strings on the CMB power spectra. The new cosmic string spectra (presented in a previous work) were improved especially for small angular scales, through the use of larger Abelian Higgs string simulations and careful extrapolation. If Abelian Higgs strings are present then we find improved bounds on their contribution to the CMB anisotropies, f10< 0.095, and on their tension, G\mu< 0.57 x 10^-6, both at 95% confidence level using WMAP7 data; and f10 < 0.048 and G\mu < 0.42 x 10^-6 using all the CMB data. We also find that using all the CMB data, a scale invariant initial perturbation spectrum, ns=1, is now disfavoured at 2.4\sigma\ even if strings are present. A Bayesian model selection analysis no longer indicates a preference for strings.Comment: 8 pages, 3 figures; Minor corrections, matches published versio

Polyphenol Content and Antioxidant Activity of Sour Cherries From Serbia

The aim of this study was to evaluate the content of phenolics: the total phenols (TP), flavonoids (TF), anthocyanins (TA), as well as the total antioxidant\ud capacity (TAC) in three sour cherry cultivars (Prunus cerasus L.) introduced to the southeast Serbia climate conditions. Among the investigated sour cherries,\ud „Oblačinska“ cultivar contained the highest amounts of all groups of phenolics, followed by „Cigančica“ > „Marela“. A significant difference were observed in the phenolic content among different cultivars and growing seasons (p  0.05), and the phenolic compounds were significantly higher in the growing season 2009. The examined cultivars possess a high antioxidant capacity, and all phenolics of highy correlation with TAC. The following compounds were identified and quantified using HPLC-DAD: 4 anthocyanins, the most abundant of which was cyanidin-3-glucoside in “Marela” and “Oblačinska”, and cyanidin-3-glucosylrutinoside in „Cigančica“, and 4 hydroxycinnamic acids, the most abundant of which was neochlorogenic acid in all sour cherry cultivars. The growing and ripening process on the tree of sour cherry cv. „Oblačinska“ was evaluated also. The results showed significant increases in total phenols during the ripening, the total anthocyanins and total antioxidant capacity and 4 quantified anthocyanins, however the neochlorogenic acid decreased during the ripening. The study indicated that the growing and climate conditions in southeast Serbia are convenient for introducing sour cherry cultivars.\u

Post-peak fracture behavior during direct shear tests of rock joints

see Abstract Volum

Modeling Single Electron Transfer in Si:P Double Quantum Dots

Solid-state systems such as P donors in Si have considerable potential for realization of scalable quantum computation. Recent experimental work in this area has focused on implanted Si:P double quantum dots (DQDs) that represent a preliminary step towards the realization of single donor charge-based qubits. This paper focuses on the techniques involved in analyzing the charge transfer within such DQD devices and understanding the impact of fabrication parameters on this process. We show that misalignment between the buried dots and surface gates affects the charge transfer behavior and identify some of the challenges posed by reducing the size of the metallic dot to the few donor regime.Comment: 11 pages, 7 figures, submitted to Nanotechnolog

Seven recommendations to make your invasive alien species data more useful

Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost

Length-dependent prediction of protein intrinsic disorder

BACKGROUND: Due to the functional importance of intrinsically disordered proteins or protein regions, prediction of intrinsic protein disorder from amino acid sequence has become an area of active research as witnessed in the 6th experiment on Critical Assessment of Techniques for Protein Structure Prediction (CASP6). Since the initial work by Romero et al. (Identifying disordered regions in proteins from amino acid sequences, IEEE Int. Conf. Neural Netw., 1997), our group has developed several predictors optimized for long disordered regions (>30 residues) with prediction accuracy exceeding 85%. However, these predictors are less successful on short disordered regions (≤30 residues). A probable cause is a length-dependent amino acid compositions and sequence properties of disordered regions. RESULTS: We proposed two new predictor models, VSL2-M1 and VSL2-M2, to address this length-dependency problem in prediction of intrinsic protein disorder. These two predictors are similar to the original VSL1 predictor used in the CASP6 experiment. In both models, two specialized predictors were first built and optimized for short (≤30 residues) and long disordered regions (>30 residues), respectively. A meta predictor was then trained to integrate the specialized predictors into the final predictor model. As the 10-fold cross-validation results showed, the VSL2 predictors achieved well-balanced prediction accuracies of 81% on both short and long disordered regions. Comparisons over the VSL2 training dataset via 10-fold cross-validation and a blind-test set of unrelated recent PDB chains indicated that VSL2 predictors were significantly more accurate than several existing predictors of intrinsic protein disorder. CONCLUSION: The VSL2 predictors are applicable to disordered regions of any length and can accurately identify the short disordered regions that are often misclassified by our previous disorder predictors. The success of the VSL2 predictors further confirmed the previously observed differences in amino acid compositions and sequence properties between short and long disordered regions, and justified our approaches for modelling short and long disordered regions separately. The VSL2 predictors are freely accessible for non-commercial use a