494 research outputs found
Influence of phytosterols addition in the rheology and sensory attributes of dark chocolate
AbstractThis study evaluated the influence of the application of three types of phytosterols (A- encapsulated pine phytosterol powder; B- oil-based soy phytosterol and C-powder soy phytosterol) in the rheological and sensory properties of dark chocolate. It was observed that the application of phytosterols influenced the rheological properties of the chocolates, mainly the A and C types. On the other hand, the rheological behaviour of the chocolate with B phytosterol was similar to the standard chocolate. In the sensory evaluation, the chocolates with B and C phytosterol showed similar results compared to the standard chocolate in the various attributes tested. Chocolate A presented the lowest acceptance for some of the sensory attributes evaluated
The angular diameter of R Doradus: a nearby Mira-like star
We find the angular diameter of R Doradus to be 57 +/- 5 mas, exceeding that
of Betelgeuse and implying that R Dor is larger in apparent size than every
star except the Sun. R Dor is shown to be closely related to the Mira
variables. We estimate an effective temperature of 2740 +/- 190 K, a distance
of 61 +/- 7 pc, a luminosity of 6500 +/- 1400 Lsol and a radius of 370 +/- 50
Rsol. The characteristics of R Dor are consistent with it being near the edge
of a Mira instability strip. We detect non-zero closure phases from R Dor,
indicating an asymmetric brightness distribution. We also observed W Hya, a
small-amplitude Mira, for which we find an angular diameter of 44 +/- 4 mas.Comment: MNRAS (accepted); 7 pages, LaTeX with necessary style file and
PostScript figure
Economic evaluation of a behavior-modifying intervention to enhance antiepileptic drug adherence
Between 35% and 50% of patients with epilepsy are reported to be not fully adherent to their medication schedule. We aimed to conduct an economic evaluation of strategies for improving adherence to antiepileptic drugs. Based on the findings of a systematic review, we identified an implementation intention intervention (specifying when, where, and how to act) which was tested in a trial that closely resembled current clinical management of patients with epilepsy and which measured adherence with an objective and least biased method. Using patient-level data, trial patients were matched with those recruited for the Standard and New Antiepileptic Drugs trial according to their clinical characteristics and adherence. Generalized linear models were used to adjust cost and utility in order to estimate the incremental cost per quality-adjusted life-year (QALY) gained from the perspective of the National Health Service in the UK. The mean cost of the intervention group, £1340 (95% CI: £1132, £1688), was marginally lower than that of the control group representing standard care, £1352 (95% CI: £1132, £1727). Quality-adjusted life-year values in the intervention group were higher than those in the control group, i.e., 0.75 (95% CI: 0.70, 0.79) compared with 0.74 (95% CI: 0.68, 0.79), resulting in a cost saving of £12 (€15, US$19) and with the intervention being dominant. The probability that the intervention is cost-effective at a threshold of £20,000 per QALY is 94%. Our analysis lends support to the cost-effectiveness of a self-directed, implementation intention intervention for improving adherence to antiepileptic drugs. However, as with any modeling dependent on limited data on efficacy, there is considerable uncertainty surrounding the clinical effectiveness of the intervention which would require a substantive trial for a more definitive conclusion
PoTS - A Secure Proof of TEE-Stake for Permissionless Blockchains
Proof-of-Stake (PoS) protocols have been actively researched for the past few years. PoS finds direct applicability in permissionless blockchain platforms and emerges as one of the strongest candidates to replace the largely inefficient Proof of Work mechanism that is currently plugged in the majority of existing permissionless blockchain systems. Although a number of PoS variants have been proposed, these protocols suffer from a number of security shortcomings. Namely, most existing PoS variants are either subject to the nothing at stake, the long range, or the stake grinding attacks which considerably degrade security in the blockchain. These shortcomings do not result from a lack of foresight when designing these protocols, but are inherently due to the ease of manipulating stake when compared to other more established variants, such as work . In this paper, we address these problems and propose a secure Proof of Stake protocol, PoTS, that leverages Trusted Execution Environments (TEEs), such as Intel SGX, to ensure that each miner can generate at most one block per height for strictly increasing heights—thus thwarting the problem of nothing at stake and a large class of long-range attacks. In combination with TEEs, PoTS additionally uses cryptographic techniques to also prevent grinding attacks and protect against posterior corruption. We show that our protocol is secure, in the sense of well-established cryptographic notions for blockchain protocols, down to realistic hardware assumptions on TEE and well-established cryptographic assumptions. Finally, we evaluate the performance of our proposal by means of implementation. Our evaluation results show that PoTS offers a strong tradeoff between security of performance of the underlying PoS protocol
Features of mammalian microRNA promoters emerge from polymerase II chromatin immunoprecipitation data
Background: MicroRNAs (miRNAs) are short, non-coding RNA regulators of protein coding genes. miRNAs play a very important role in diverse biological processes and various diseases. Many algorithms are able to predict miRNA genes and their targets, but their transcription regulation is still under investigation. It is generally believed that intragenic miRNAs (located in introns or exons of protein coding genes) are co-transcribed with their host genes and most intergenic miRNAs transcribed from their own RNA polymerase II (Pol II) promoter. However, the length of the primary transcripts and promoter organization is currently unknown. Methodology: We performed Pol II chromatin immunoprecipitation (ChIP)-chip using a custom array surrounding regions of known miRNA genes. To identify the true core transcription start sites of the miRNA genes we developed a new tool (CPPP). We showed that miRNA genes can be transcribed from promoters located several kilobases away and that their promoters share the same general features as those of protein coding genes. Finally, we found evidence that as many as 26% of the intragenic miRNAs may be transcribed from their own unique promoters. Conclusion: miRNA promoters have similar features to those of protein coding genes, but miRNA transcript organization is more complex. © 2009 Corcoran et al
A locally quadratic Glimm functional and sharp convergence rate of the Glimm scheme for nonlinear hyperbolic systems
Consider the Cauchy problem for a strictly hyperbolic,
quasilinear system in one space dimension u_t+A(u) u_x=0,\qquad u(0,x)=\bar
u(x), \eqno (1) where is a smooth matrix-valued map, and
the initial data is assumed to have small total variation. We
investigate the rate of convergence of approximate solutions of (1) constructed
by the Glimm scheme, under the assumption that, letting ,
denote the -th eigenvalue and a corresponding eigenvector of
, respectively, for each -th characteristic family the linearly
degenerate manifold is either the whole space, or it is empty, or it consists of
a finite number of smooth, -dimensional, connected, manifolds that are
transversal to the characteristic vector field . We introduce a Glimm type
functional which is the sum of the cubic interaction potential defined in
\cite{sie}, and of a quadratic term that takes into account interactions of
waves of the same family with strength smaller than some fixed threshold
parameter. Relying on an adapted wave tracing method, and on the decrease
amount of such a functional, we obtain the same type of error estimates valid
for Glimm approximate solutions of hyperbolic systems satisfying the classical
Lax assumptions of genuine nonlinearity or linear degeneracy of the
characteristic families.Comment: To appear on Archive for Rational Mechanics and Analysi
Transcriptional role of cyclin D1 in development revealed by a “genetic-proteomic” screen
Author manuscript: 2010 September 22.Cyclin D1 belongs to the core cell cycle machinery, and it is frequently overexpressed in human cancers[superscript 1, 2]. The full repertoire of cyclin D1 functions in normal development and oncogenesis is unclear at present. Here we developed Flag- and haemagglutinin-tagged cyclin D1 knock-in mouse strains that allowed a high-throughput mass spectrometry approach to search for cyclin D1-binding proteins in different mouse organs. In addition to cell cycle partners, we observed several proteins involved in transcription. Genome-wide location analyses (chromatin immunoprecipitation coupled to DNA microarray; ChIP-chip) showed that during mouse development cyclin D1 occupies promoters of abundantly expressed genes. In particular, we found that in developing mouse retinas—an organ that critically requires cyclin D1 function[superscript 3, 4]—cyclin D1 binds the upstream regulatory region of the Notch1 gene, where it serves to recruit CREB binding protein (CBP) histone acetyltransferase. Genetic ablation of cyclin D1 resulted in decreased CBP recruitment, decreased histone acetylation of the Notch1 promoter region, and led to decreased levels of the Notch1 transcript and protein in cyclin D1-null (Ccnd1-/-) retinas. Transduction of an activated allele of Notch1 into Ccnd1-/- retinas increased proliferation of retinal progenitor cells, indicating that upregulation of Notch1 signalling alleviates the phenotype of cyclin D1-deficiency. These studies show that in addition to its well-established cell cycle roles, cyclin D1 has an in vivo transcriptional function in mouse development. Our approach, which we term ‘genetic–proteomic’, can be used to study the in vivo function of essentially any protein
IMPACTO DA “MÃE DE LEITE ELETRÔNICA” NO DESEMPENHO ZOOTÉCNICO DE LEITÕES LACTENTES
Com os avanços da genética na suinocultura e a aplicação de tecnologias no manejo o número de leitões nascidos, por parto, tem aumentado significativamente. Por consequência, as leitegadas raramente são uniformes e muitos leitões apresentam baixo peso ao nascimento. Pesquisas indicam que a cada leitão extra na média de nascidos acarreta uma redução de 100g no peso ao nascimento, dobrando o número de leitões que nascem com peso abaixo de 800g. O aumento da taxa de mortalidades entre os leitões com baixo peso, ainda nos primeiros dias de vida, é algo comum. Logo, torna-se essencial o emprego de alternativas que contribuam tanto para a diminuição da mortalidade pré-desmame quanto para o alcance da uniformidade da leitegada. Com o intuito de melhorar esses índices foi avaliado a influência do equipamento “mãe de leite eletrônica” sobre o desempenho zootécnico de leitões no período entre o nascimento e o desmame. O equipamento foi cedido por colaboradores da Empresa STA, de Joinville/SC. Cada lote experimental contou com dois grupos: o controle (GC) e o tratamento (GT). No GC os leitões receberam apenas aleitamento natural, fornecido pela mãe. No GT os leitões foram submetidos ao regime de aleitamento misto (natural, fornecido pela mãe; e o artificial, fornecido pelo equipamento o leite de vaca). Foram avaliadas 6 leitegadas, duas por experimento. As fêmeas eram provenientes de matrizes híbridas Landrace x Large White, entre o 3º e 6º parto. Ao todo realizaram-se 3 procedimentos experimentais. O aleitamento propiciado pelo equipamento beneficiou todas as leitegadas do GT já nos três primeiros dias de vida. Muitos leitões que apresentaram dificuldades de amamentarem-seadequadamente na mãe, pela competição da leitegada pelos tetos, conseguiram sobreviver pela disponibilidade de leite oferecida artificialmente. Por ocasião do desmame, o peso médio e o número de leitões foram similares numericamente entre as 6 leitegadas avaliadas durante o período experimental. No entanto, no GT observou-se maior desuniformidade entre os leitões, uma vez que alguns animais ganharam peso mais rápido pelo acesso também ao leite artificial. Apesar de auxiliar na sobrevivência dos leitões, evitando maiores taxas de mortalidade pré-desmame, principalmente nos primeiros dias após o parto, não houve contribuição do equipamento sobre a uniformidade dos lotes. Concluímos que a “mãe de leite eletrônica” possibilitou não só o interesse como também a ingestão de leite artificial pelos leitões, de modo com que mais tetos ficassem disponíveis para outros leitões durante a mamada. Evidenciamos também que tanto leitões refugos como os mais fracos se beneficiaram do aleitamento misto, mantendo seu desenvolvimento de forma adequada até o desmame. Por fim, a equipe indica a utilização do equipamento, no mínimo, durante os 14 primeiros dias de vida dos leitões
Intramolecular additions of various π-nucleophiles to chemoselectively activated amides and application to the synthesis of (±)-tashiromine
Abstract: Vilsmeier-Haack type cyclizations proved to be particularly efficient for generating parts of the polycyclic
cores of many alkaloids, although only monocyclizations have so far been reported. With the goal of
rapidly and efficiently constructing polycyclic alkaloids, we decided to exploit the Vilsmeier-Haack
reaction by utilizing iminium ions successively generated and trapped with tethered nucleophiles. To
develop such a strategy, we had to set the first cyclization. This constitutes a great challenge in itself
because amide activation conditions are usually not compatible with tethered nucleophiles, except for
indoles and aromatic rings which have already been reported. This paper describes the comprehensive
study of intramolecular addition of silyl enol ethers, allylsilanes, and enamines to chemoselectively activated
formamides, aliphatic amides, and lactams. Good to excellent yields were obtained for the 5-exo, 6-exo,
and 6-endo modes of cyclization. Moreover, we demonstrated that the species in solution after the
cyclization are iminium ions. This is highly encouraging for the development of bis-cyclization strategies.
An expeditious total synthesis of (()-tashiromine is also reported
Integrated gradient interpretation techniques for 2D and 3D gravity data interpretation
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