612 research outputs found
A full approximation scheme multilevel method for nonlinear variational inequalities
We present the full approximation scheme constraint decomposition (FASCD)
multilevel method for solving variational inequalities (VIs). FASCD is a common
extension of both the full approximation scheme (FAS) multigrid technique for
nonlinear partial differential equations, due to A.~Brandt, and the constraint
decomposition (CD) method introduced by X.-C.~Tai for VIs arising in
optimization. We extend the CD idea by exploiting the telescoping nature of
certain function space subset decompositions arising from multilevel mesh
hierarchies. When a reduced-space (active set) Newton method is applied as a
smoother, with work proportional to the number of unknowns on a given mesh
level, FASCD V-cycles exhibit nearly mesh-independent convergence rates, and
full multigrid cycles are optimal solvers. The example problems include
differential operators which are symmetric linear, nonsymmetric linear, and
nonlinear, in unilateral and bilateral VI problems.Comment: 25 pages, 9 figure
BlogForever D3.3: Development of the Digital Rights Management Policy
This report presents a set of recommended practices and approaches that a future BlogForever repository can use to develop a digital rights management policy. The report outlines core legal aspects of digital rights that might need consideration in developing policies, and what the challenges are, in particular, in relation to web archives and blog archives. These issues are discussed in the context of the digital information life cycle and steps that might be taken within the workflow of the BlogForever platform to facilitate the gathering and management of digital rights information. Further, the reports on interviews with experts in the field highlight current perspectives on rights management and provide empirical support for the recommendations that have been put forward
Connectivity in the Deep: Phylogeography of the Velvet Belly Lanternshark
PublishedThe velvet belly lanternshark, Etmopterus spinax, is a deep-sea bioluminescent squaloid shark, found predominantly in the northeast Atlantic and Mediterranean Sea. It has been exposed to relatively high levels of mortality associated with by-catch in some regions. Its late maturity and low fecundity potentially renders it vulnerable to over-exploitation, although little remains known about processes of connectivity between key habitats/regions. This study utilised DNA sequencing of partial regions of the mitochondrial control region and nuclear ribosomal internal transcribed spacer 2 to investigate population structure and phylogeography of this species across the northeast Atlantic and Mediterranean Basin. Despite the inclusion of samples from the range edges or remote locations, no evidence of significant population structure was detected. An important exception was identified using the control region sequence, with much greater (and statistically significant) levels of genetic differentiation between the Mediterranean and Atlantic. This suggests that the Strait of Gibraltar may represent an important bathymetric barrier, separating regions with very low levels of female dispersal. Bayesian estimation of divergence time also places the separation between the Mediterranean and Atlantic lineages within the last 100,000 years, presumably connected with perturbations during the last Glacial Period. These results demonstrate population subdivision at a much smaller geographic distance than has generally been identified in previous work on deep-sea sharks. This highlights a very significant role for shallow bathymetry in promoting genetic differentiation in deepwater taxa. It acts as an important exception to a general paradigm of marine species being connected by high levels of gene-flow, representing single stocks over large scales. It may also have significant implications for the fisheries management of this species.We would like to thank Trude Thangstad, Merete Kvalsund (Institute of Marine Research, Norway), Cecilia Pinto, Eleonora de Sabata and the scientists and crew of the RV Celtic Explorer for assistance in the collection of samples. Funding for this project was provided by the University of Salford and the University of Bristol. We are grateful to all those who helped with sample collection, including the MEDITS survey programme, the Department of Fisheries and Marine Research (DFMR) of Cyprus, the Annual Demersal and Deep Water Fish Monitoring Surveys financed by the Azores Government and the CONDOR project (supported by a grant from Iceland, Liechtenstein, Norway through the EEA Financial Mechanism (PT0040/2008)
Scaling of cardiac morphology is interrupted by birth in the developing sheep Ovis aries.
Scaling of the heart across development can reveal the degree to which variation in cardiac morphology depends on body mass. In this study, we assessed the scaling of heart mass, left and right ventricular masses, and ventricular mass ratio, as a function of eviscerated body mass across fetal and postnatal development in Horro sheep Ovis aries (~50-fold body mass range; N = 21). Whole hearts were extracted from carcasses, cleaned, dissected into chambers and weighed. We found a biphasic relationship when heart mass was scaled against body mass, with a conspicuous 'breakpoint' around the time of birth, manifest not by a change in the scaling exponent (slope), but rather a jump in the elevation. Fetal heart mass (g) increased with eviscerated body mass (Mb , kg) according to the power equation 4.90 Mb0.88 ± 0.26 (± 95%CI) , whereas postnatal heart mass increased according to 10.0 Mb0.88 ± 0.10 . While the fetal and postnatal scaling exponents are identical (0.88) and reveal a clear dependence of heart mass on body mass, only the postnatal exponent is significantly less than 1.0, indicating the postnatal heart becomes a smaller component of body mass as the body grows, which is a pattern found frequently with postnatal cardiac development among mammals. The rapid doubling in heart mass around the time of birth is independent of any increase in body mass and is consistent with the normalization of wall stress in response to abrupt changes in volume loading and pressure loading at parturition. We discuss variation in scaling patterns of heart mass across development among mammals, and suggest that the variation results from a complex interplay between hard-wired genetics and epigenetic influences
Adapting research-tested computerized tailored interventions for broader dissemination and implementation
This paper focuses on the process for adapting existing legacy computerized tailored intervention (CTI) programs and implications for future development of CTI to ensure that interventions can be disseminated and implemented in different settings. A significant amount of work is required to adapt existing CTI for new research applications and public health interventions. Most new CTI are still developed from scratch, with minimal re-use of software or message content, even when there are considerable overlaps in functionality. This is largely a function of the substantial technical, organizational, and content-based barriers to adapting and disseminating CTI. CTI developers should thus consider dissemination and re-use early in the design phase of their systems. This is not intended to be a step-by-step guide on how to adopt or disseminate research-tested CTI, but rather a discussion that highlights issues to be considered for adapting and disseminating evidence-based CTI
Stereoselective Metal-Free Reduction of Chiral Imines in Batch and Flow Mode: A Convenient Strategy for the Synthesis of Chiral Active Pharmaceutical Ingredients
he convenient, metal-free reduction of imines that
contain an inexpensive and removable chiral auxiliary allowed
for the synthesis of the immediate precursors of chiral active
pharmaceutical ingredients (APIs). This protocol was carried out
under batch and flow conditions to give the correspoding prod-
ucts in high yields with almost complete stereocontrol. In the
presence of trichlorosilane, an inexpensive and nontoxic reduc-
ing agent, and an achiral Lewis base such as N,N-dimethyl-
Introduction
The pharmaceutical industry is gradually progressing towards
enantiopure formulations. Most newly introduced drugs are
chiral, and it is expected that approximately 95 % of pharma-
ceutical drugs will be chiral by 2020.
[1]
In this context, chiral
amines are considered a class of paramount importance, be-
cause they are found in a plethora of compounds such as those
of pharmaceutical interest as well as those developed for agro-
chemicals, fragrances, and fine chemicals.
[2]
The reduction of
the C=N group is one of the most widely used approaches to
synthesize chiral amines, and over the last ten years, successful
catalytic enantioselective methods based on both metal-pro-
moted
[3]
and organocatalyzed
[4]
strategies have been devel-
oped.
When an industrial synthesis of a chiral pharmaceutical prod-
uct must be planned, however, issues such as the chemical effi-
ciency and robustness of the procedure, its general applicabil-
ity, and economic considerations become crucially important.
For these reasons, the applications of many chiral catalytic sys-
tems are often not feasible, and the use of inexpensive and
readily available chiral auxiliaries becomes an attractive and
economic alternative. This also holds true for the synthesis of
[a] Dipartimento di Chimica, Università degli Studi di Milano,
via Golgi 19, 20133 Milano, Italy
E-mail: [email protected]
http://users2.unimi.it/Benagliagroup
[b] Istituto di Scienze e Tecnologie Molecolari ISTM-CNR,
Via Golgi 19, 20133 Milano, Italy
[c] Department of Chemistry and Chemistry Center of Évora,
University of Évora,
Rua Romão Ramalho, 59, 7000 Évora, Portugal
Supporting information and ORCID(s) from the author(s) for this article are
available on the WWW under http://dx.doi.org/10.1002/ejoc.201601268.
Eur. J. Org. Chem. 2017, 39–44
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim39
formamide, the formal syntheses of Rivastgmine, calcimimetic
NPS R-568, and a Rho kinases inhibitor were successfully accom-
plished. For the first time, both the diastereoselective imine re-
duction and the auxiliary removal were efficiently performed in
a micro- or mesoreactor under continuous-flow conditions,
which paved the way towards the development of a practical
process for the syntheses of industrially relevant, biologically
active, enantiopure N-alkylamine
GNSS multi-frequency receiver single-satellite measurement validation method
A method is presented for real-time validation of GNSS measurements of a single receiver, where data from each satellite are independently processed. A geometry- free observation model is used with a reparameterized form of the unknowns to overcome rank deficiency of the model. The ionosphere error and non-constant biases such as multipath are assumed changing relatively smoothly as a function of time. Data validation and detection of errors are based on statistical testing of the observation residuals using the detection–identification–adaptation approach. The method is applicable to any GNSS with any number of frequencies. The performance of validation method was evaluated using multi-frequency data from three GNSS (GPS, GLONASS, and Galileo) that span 3 days in a test site at Curtin University, Australia. Performance of the method in detection and identification of outliers in code observations, and detection of cycle slips in phase data were examined. Results show that the success rates vary according to precision of observations and their number as well as size of the errors. The method capability is demonstrated when processing four IOV Galileo satellites in a single-point-positioning mode and in another test by comparing its performance with Bernese software in detection of cycle slips in precise point-positioning processing using GPS data
Mechano-Electric Feedback in the Fish Heart
Mechanoelectric feedback (MEF) describes the modulation of electrical activity by mechanical activity. This may occur via the activation of mechanosensitive ion channels (MSCs). MEF has not previously been investigated in fish ventricular tissue even though fish can greatly increase ventricular end diastolic volume during exercise which should therefore provide a powerful mechanical stimulus for MEF.When the ventricles of extrinsically paced, isolated working trout hearts were dilated by increasing afterload, monophasic action potential (MAP) duration was significantly shortened at 25% repolarisation, unaltered at 50% repolarisation and significantly lengthened at 90% repolarisation. This observation is consistent with the activation of cationic non-selective MSCs (MSC(NS)s). We then cloned the trout ortholog of TRPC1, a candidate MSC(NS) and confirmed its presence in the trout heart.Our results have validated the use of MAP technology for the fish heart and suggest that, in common with amphibians and mammals, MEF operates in fish ventricular myocardium, possibly via the activation of mechanosensitive TRPC1 ion channels
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