9,031 research outputs found
Food Lion and the Media’s Liability for Newsgathering Torts: A Symposium Preview
Abans de l'arribada de Pere Alberch a la catedral de Barcelona, el magisteri de l'orgue havia estat en mans de l'organista Joan Ferrer, el qual l'exercà entre 1515 i 1536, essent mestre de cant entre 1513 i 1517. La identitat de l'organista de la catedral de Barcelona correspon a la del compositor «Johannes Ffarer», autor del motet «Domine non secundum» del Cancionero musical de Segovia (CMS). La identificació entre «Johannes Ffarer» i Joan Ferrer, i la presència del seu motet processional «Domine non secundum» juntament amb la de l'himne «Conditor alme siderunt» de Marturià Prats, fan palesa la recepció que la capella flamenca va fer del repertori polifònic d'aquests dos compositors catalans, les obres dels quals es devien incorporar al cançoner durant el prolongat sojorn que la capella de Carles I va fer a Barcelona, en el transcurs de l'any 1519. D'altra banda, i grà cies a la documentació capitular de les seus de Vic, Tortosa i Tarragona, sabem que Marturià Prats, i també Antoni Marlet, romanien vinculats a la capella nobilià ria que l'infant Enric, comte d'Empúries, mantenia al seu palau del carrer Ample de Barcelona. En el marc del context urbà , social i musical de la Barcelona de principis del segle xvi no costa gaire d'imaginar com devien sovintejar els contactes, i, amb ells, les avinences i els intercanvis musicals en-
tre els músics de la capella flamenca i els de les capelles nobilià ries dels Cardona, l'infant Enric, els Montcada, a banda dels cantors de la catedral i dels de les grans parròquies de la ciutat. Un esdeveniment d'aquestes caracterÃstiques pot ajudar a explicar el motiu de la presència de les dues obres de Joan Ferrer i Marturià Prats en el CMS, convivint amb la riquesa del seu repertori francoflamenc i castellà .Before Pere Alberch arrived at Barcelona Cathedral, the organ master had been the organist Joan Ferrer in the period between 1515 and 1536, and he had also been the magister cantus between 1513 and 1517. The identity of the organist of Barcelona Cathedral corresponds to that of the composer Johannes Ffarer, who was the author of the motet Domine non secundum of the Cancionero musical de Segovia. The identification between Johannes Ffarer and Joan Ferrer, and the presence of his processional motet Domine non secundum together with that of the hymn Conditor alme siderunt of Marturià Prats, evidence the Flemish chapel's reception of the polyphonic repertoire of these two Catalan composers, whose works must have been added to the cancionero or song-book during the long stay of Charles I's chapel in Barcelona in the course of the year 1519. Moreover, thanks to the chapter documents of the cathedrals of Vic, Tortosa and Tarragona, we know that Marturià Prats as well as Antoni Marlet remained attached to the noble chapel which Prince Henry, Count of Empúries, kept in his palace at Carrer Ample in Barcelona. Within the urban, social and musical context of the Barcelona of the early 16th century, it is easy to imagine how frequent the contacts must have been and consequently the understandings and musical exchanges between the musicians of the Flemish chapel and those of the noble chapels of the Cardonas, Prince Henry, the Montcadas, etc., as well as the singers of the Cathedral and those of the major parish churches of the city. An event of this type could help to explain the reason for the presence of the two works of Joan Ferrer and Marturià Prats in the CMS, together with the rich Franco-Flemish and Castilian repertoire to be found there
Analytical prediction of chatter stability for variable pitch and variable helix milling tools
Regenerative chatter is a self-excited vibration that can occur during milling and other machining processes. It leads to a poor surface finish, premature tool wear, and potential damage to the machine or tool. Variable pitch and variable helix milling tools have been previously proposed to avoid the onset of regenerative chatter. Although variable pitch tools have been considered in some detail in previous research, this has generally focussed on behaviour at high radial immersions. In contrast there has been very little work focussed on predicting the stability of variable helix tools. In the present study, three solution processes are proposed for predicting the stability of variable pitch or helix milling tools. The first is a semi-discretisation formulation that performs spatial and temporal discretisation of the tool. Unlike previously published methods this can predict the stability of variable pitch or variable helix tools, at low or high radial immersions. The second is a time-averaged semi-discretisation formulation that assumes time-averaged cutting force coefficients. Unlike previous work, this can predict stability of variable helix tools at high radial immersion. The third is a temporal-finite element formulation that can predict the stability of variable pitch tools with a constant uniform helix angle, at low radial immersion. The model predictions are compared to previously published work on variable pitch tools, along with time-domain model simulations. Good agreement is found with both previously published results and the time-domain model. Furthermore, cyclic-fold bifurcations were found to exist for both variable pitch and variable helix tools at lower radial immersions
A direct approach to co-universal algebras associated to directed graphs
We prove directly that if E is a directed graph in which every cycle has an
entrance, then there exists a C*-algebra which is co-universal for
Toeplitz-Cuntz-Krieger E-families. In particular, our proof does not invoke
ideal-structure theory for graph algebras, nor does it involve use of the gauge
action or its fixed point algebra.Comment: 9 pages; V2: the definition of a Toeplitz-Cuntz-Krieger -family
has been correcte
Application of projection algorithms to differential equations: boundary value problems
The Douglas-Rachford method has been employed successfully to solve many
kinds of non-convex feasibility problems. In particular, recent research has
shown surprising stability for the method when it is applied to finding the
intersections of hypersurfaces. Motivated by these discoveries, we reformulate
a second order boundary valued problem (BVP) as a feasibility problem where the
sets are hypersurfaces. We show that such a problem may always be reformulated
as a feasibility problem on no more than three sets and is well-suited to
parallelization. We explore the stability of the method by applying it to
several examples of BVPs, including cases where the traditional Newton's method
fails
Potential effects of environmental change on mining wastes in a hyperarid climate
Three desert washes were sampled to evaluate the transport of contaminated sediments from abandoned mining sites to downwash environments. The area of concern is an extreme arid climate considered stable and not to pose pathways for contaminated sediments to impact downwash environments. Research of mine wastes in Nelson, Nevada has shown that residual geogenic and anthropogenic trace elements have been mobilized in surface sediments as a result of storm event. Cyanide and trace elements, especially mercury and lead, have transported to 6000 m downwash from source areas. Short term environmental impacts appear to be minimal because of present-day environmental conditions. However, climate shifts caused by the El Nino Southern Oscillations or even a dramatic climate shift might increase regional precipitation promoting a more rapid erosion of contaminated sediment. Currently, wash sediments do not contain levels of CN- or trace elements that pose threats to the environment; however, if erosion and transport of mining waste increased because of additional precipitation, then CN- and trace elements loading in storm water would increase, with their possibly delivery to Lake Mohave
Forecasting and Conditional Projection Using Realistic Prior Distributions
This paper develops a forecasting procedure based on a Bayesian method for estimating vector autoregressions. The procedure is applied to ten macroeconomic variables and is shown to improve out-of-sample forecasts relative to univariate equations. Although cross-variables responses are damped by the prior, considerable interaction among the variables is shown to be captured by the estimates.We provide unconditional forecasts as of 1982:12 and 1983:3.We also describe how a model such as this can be used to make conditional projections and to analyze policy alternatives. As an example, we analyze a Congressional Budget Office forecast made in 1982:12.While no automatic causal interpretations arise from models like ours, they provide a detailed characterization of the dynamic statistical interdependence of a set of economic variables, which may help inevaluating causal hypotheses, without containing any such hypotheses themselves.
Nonmarket Valuation of Recreational Pursuits in Tennessee: An Application of Travel Cost and Contingent Valuation Methods
In order to assure that public lands are being used in an efficient manner, both market and non-market values of these lands must be compared. Two popular recreational pursuits, off-highway vehicle recreation and rock climbing, were analyzed using basic economic modeling techniques to provide insight into user behavior as well as estimates of value. The scope of the study was off-highway vehicle recreation in the state of Tennessee and rock climbing at the Obed Wild and Scenic River. The objectives were to: i) document use numbers for both recreational pursuits, ii) analyze individual demographics of both user groups, iii) model user behavior for both· user groups, iv) identify the acceptance/effectiveness of two proposed fee programs for off-highway vehicle recreation, v) estimate the value of both recreational pursuits in terms of consumer surplus, and vi) formulate management prescriptions based on these findings. Data for the OHV portion of the survey was obtained from both on-site and phone surveys conducted throughout the state of Tennessee. Rock climbing survey data were obtained through on-site surveys performed at the Obed Wild and Scenic River in Morgan County, Tennessee. In addition to use numbers and personal demographics, travel cost expenditures and annual trip estimates were obtained for both types of recreation. Poisson regression techniques were used to estimate patterns in user behavior as well as various consumer surplus measures. In addition, logistic regression was used to analyze contingent valuation payment card data to determine user acceptance of two proposed fee programs. As expected by theory, travel costs were found to have a negative effect on the number of trips taken for each type of recreation. Consumer surplus estimates per trip were found to range between 61 depending on the type of off-highway vehicle used while consumer surplus per trip for rock climbing was found to be significantly higher at $170. Based on these estimates of use and trip taking behavior, general management recommendations are suggested for both types of recreation
PLGA-modified nanoparticles for the treatment of hypo-vascularized HPV-related cervical cancers.
A major challenge associated with delivery of active agents in the female reproductive tract (FRT) is the ability of agents to efficiently diffuse through the cervicovaginal mucosa (CVM) and reach the underlying sub-epithelial immune cell layer and vasculature. A variety of drug delivery vehicles have been employed to improve the delivery of agents across the CVM and offer the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract. Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, polymeric NPs represent a promising option that has shown improved distribution through the CVM. This work summarizes recent experimental studies that have evaluated NP transport in the FRT, and highlights research areas that more thoroughly and efficiently inform polymeric NP design, including mathematical modeling.
The studies presented below further expand on this to investigate the application of NPs in treating cancers found within the FRT. Advanced stage cancer treatments are often invasive and painful—typically comprised of surgery, chemotherapy, and/or radiation treatment. In addition to the poor transport associated with intravaginal delivery, low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies.
To address these transport challenges, NPs are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. In the work presented below, the effect of surface modification with stealth polyethylene–glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies on NP distribution and chemotherapeutic efficacy, which is defined in this work as the ability of NPs to impart drug cytotoxicity and potency, was evaluated with the use of 3D cell culture models representing hypo-vascularized cervical cancerous tissue
- …