A symmetry-adapted numerical scheme for SDEs

We propose a geometric numerical analysis of SDEs admitting Lie symmetries which allows us to individuate a symmetry adapted coordinates system where the given SDE has notable invariant properties. An approximation scheme preserving the symmetry properties of the equation is introduced. Our algorithmic procedure is applied to the family of general linear SDEs for which two theoretical estimates of the numerical forward error are established.Comment: A numerical example adde

A New 3D Tool for Planning Plastic Surgery

Face plastic surgery (PS) plays a major role in today medicine. Both for reconstructive and cosmetic surgery, achieving harmony of facial features is an important, if not the major goal. Several systems have been proposed for presenting to patient and surgeon possible outcomes of the surgical procedure. In this paper, we present a new 3D system able to automatically suggest, for selected facial features as nose, chin, etc, shapes that aesthetically match the patient's face. The basic idea is suggesting shape changes aimed to approach similar but more harmonious faces. To this goal, our system compares the 3D scan of the patient with a database of scans of harmonious faces, excluding the feature to be corrected. Then, the corresponding features of the k most similar harmonious faces, as well as their average, are suitably pasted onto the patient's face, producing k+1 aesthetically effective surgery simulations. The system has been fully implemented and tested. To demonstrate the system, a 3D database of harmonious faces has been collected and a number of PS treatments have been simulated. The ratings of the outcomes of the simulations, provided by panels of human judges, show that the system and the underlying idea are effectiv

Constrained Allocation Flux Balance Analysis

New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws.Comment: 21 pages, 6 figures (main) + 33 pages, various figures and tables (supporting); for the supplementary MatLab code, see http://tinyurl.com/h763es

Theoretical evidence for efficient p-type doping of GaN using beryllium

Ab initio calculations predict that Be is a shallow acceptor in GaN. Its thermal ionization energy is 0.06 eV in wurtzite GaN; the level is valence resonant in the zincblende phase. Be incorporation is severely limited by the formation of Be_3N_2. We show however that co-incorporation with reactive species can enhance the solubility. H-assisted incorporation should lead to high doping levels in MOCVD growth after post-growth annealing at about 850 K. Be-O co-incorporation produces high Be and O concentrations at MBE growth temperatures.Comment: revised Feb 24 199

Tracheocutaneous fistula in patients undergoing supracricoid partial laryngectomy: the role of chronic aspiration

The aim of the present retrospective controlled study was to analyse and compare risk factors for tracheocutaneous fistula in patients who received tracheostomy after supracricoid partial laryngectomy with those who received tracheostomy for other causes. We enrolled 39 patients with tracheocutaneous fistulas who were divided into two groups. The first received temporary tracheostomy for supracricoid partial laryngectomies (n = 21), while the control group consisted of patients who received temporary tracheostomy for other causes (n = 18). Risk factors believed to play a role in the pathogenesis of tracheocutaneous fistula were examined including advanced age, cardiopathy, local infections, radiotherapy, elevated body mass index, malnutrition, decannulation time and aspiration grade. The Leipzig and Pearson scale score was significantly higher in the supracricoid partial laryngectomy group (p = 0.006 and 0.031 for univariate and multivariate analyses, respectively). The penetration/aspiration scale score was significantly higher in the supracricoid partial laryngectomy group as determined by univariate analysis (p = 0.014). The decannulation time was significantly lower in the supracricoid partial laryngectomy group (p = 0.004 and 0.0004 for univariate and multivariate analyses, respectively). The number of surgical closures for tracheocutaneous fistula was significantly higher in the supracricoid partial laryngectomy group by univariate analysis (p = 0.027). These results suggest that chronic aspiration and related cough may be important pathogenic factors for tracheocutaneous fistula and could be responsible for the significantly higher rates of closure failure in patients after supracricoid partial laryngectomy

Testing the Color Charge and Mass Dependence of Parton Energy Loss with Heavy-to-light Ratios at RHIC and LHC

The ratio of nuclear modification factors of high-pT heavy-flavored mesons to light-flavored hadrons (``heavy-to-light ratio'') in nucleus-nucleus collisions tests the partonic mechanism expected to underlie jet quenching. Heavy-to-light ratios are mainly sensitive to the mass and color-charge dependences of medium-induced parton energy loss. Here, we assess the potential for identifying these two effects in D and B meson production at RHIC and at the LHC. To this end, we supplement the perturbative QCD factorized formalism for leading hadron production with radiative parton energy loss. For D meson spectra at high but experimentally accessible transverse momentum (10 < pT < 20 GeV) in Pb-Pb collisions at the LHC, we find that charm quarks behave essentially like light quarks. However, since light-flavored hadron yields are dominated by gluon parents, the heavy-to-light ratio of D mesons is a sensitive probe of the color charge dependence of parton energy loss. In contrast, due to the larger b quark mass, the medium modification of B mesons in the same kinematical regime provides a sensitive test of the mass dependence of parton energy loss. At RHIC energies, the strategies for identifying and disentangling the color charge and mass dependence of parton energy loss are more involved because of the smaller kinematical range accessible. We argue that at RHIC, the kinematical regime best suited for such an analysis of D mesons is 7 < pT < 12 GeV, whereas the study of lower transverse momenta is further complicated due to the known dominant contribution of additional, particle species dependent, non-perturbative effects.Comment: 21 pages RevTex, 9 Figure

Determining the emergence timing, morphological characteristics, and species composition of Galium populations in western Canada

Three species of Galium are commonly believed to thrive in western Canada; Galium aparine L., Galium spurium L. and Galium boreale L. Prairie weed surveys indicate that ‘cleavers’ (Galium aparine and Galium spurium) have increased in relative abundance since the 1970’s, resulting in contaminated canola seed and harvest difficulties. The ability to identify and distinguish between species is important to understand their competitive ability or potential to outcross, potentially spreading traits such as herbicide resistance between species. The objectives of this thesis were to: (1) identify variation in the ITS1-5.8S-ITS2 that could be used for species identification, (2) verify the species composition of Galium populations in western Canada, and (3) evaluate emergence timing in spring and fall and morphological traits impacting cleavers biology. The target ITS1-5.8S-ITS2 complex was isolated from the ribosomal DNA of ten cleavers populations (including reference Galium aparine and Galium spurium populations), and was then cloned and sequenced to identify single nucleotide polymorphisms that could be used to differentiate species. The results identified a sequence variation that consistently differentiates between Galium species. In addition to several variable nucleotides in the ITS regions, one variable loci was identified within the highly conserved 5.8S gene. Sequence analysis of the ITS1-5.8S-ITS2 complex of Galium field collections from western Canada indicated that all samples were G. spurium. To address objectives 2 and 3, a common garden experiment of six cleavers populations with different geographical origins in western Canada were planted and their emergence monitored for a two-week period. Various other traits were also measured for each population. Field emergence studies showed differences between populations with regard to start of emergence (~150-250 GDD) and time to 50% emergence (~275-470 GDD) in spring. Fall emergence among populations was very low (1-9%) in comparison to spring emergence (2-17%). Plant traits measured in the study did not differ between populations, supporting the results of the molecular work and leading to the conclusion that all populations were derived from a single species

Bullying and Victimization in Elementary Schools: A Comparison of Bullies, Victims, Bully/Victims, and Uninvolved Preadolescents

Research on bullying and victimization largely rests on univariate analyses and on reports from a single informant. Researchers may thus know too little about the simultaneous effects of various independent and dependent variables, and their research may be biased by shared method variance. The database for this Dutch study was large (N = 1,065) and rich enough to allow multivariate analysis and multisource information. In addition, the effect of familial vulnerability for internalizing and externalizing disorders was studied. Gender, aggressiveness, isolation, and dislikability were most strongly related to bullying and victimization. Among the many findings that deviated from or enhanced the univariate knowledge base were that not only victims and bully/victims but bullies as well were disliked and that parenting was unrelated to bullying and victimization once other factors were controlled.

Erupted Complex Odontoma Mimicking a Mandibular Second Molar

Complex odontoma (CO) is considered one of the most common odontogenic lesions, composed by a miscellaneous of dental tissue such as enamel, dentin, pulp and sometimes cementum. They may interfere with the eruption of an associated tooth, being more prevalent in the posterior mandible. CO has been rarely reported as erupted, being considered an intraosseous lesion. This is a case report of a 17-year-old male with a benign fibro-osseous lesion consistent with CO that was located at the left second molar region, above the crown of the impacted mandibular second molar tooth. The lesion was surgically removed, and the tooth had to be extracted, since there was no indication that it could erupt naturally or with orthodontic traction. The histopathological examination confirmed the diagnosis of CO and after 6 months complete bone formation was observed radiographically. An early diagnosis will provide a better treatment option, avoiding tooth extraction or a more damaging surgery

Design of an RSFQ Control Circuit to Observe MQC on an rf-SQUID

We believe that the best chance to observe macroscopic quantum coherence (MQC) in a rf-SQUID qubit is to use on-chip RSFQ digital circuits for preparing, evolving and reading out the qubit's quantum state. This approach allows experiments to be conducted on a very short time scale (sub-nanosecond) without the use of large bandwidth control lines that would couple environmental degrees of freedom to the qubit thus contributing to its decoherence. In this paper we present our design of a RSFQ digital control circuit for demonstrating MQC in a rf-SQUID. We assess some of the key practical issues in the circuit design including the achievement of the necessary flux bias stability. We present an "active" isolation structure to be used to increase coherence times. The structure decouples the SQUID from external degrees of freedom, and then couples it to the output measurement circuitry when required, all under the active control of RSFQ circuits. Research supported in part by ARO grant # DAAG55-98-1-0367.Comment: 4 pages. More information and publications at http://www.ece.rochester.edu:8080/users/sde/research/publications/index.htm