Generic Resolution Research Articles

Geodesic completeness and the lack of strong singularities in effective loop quantum Kantowski–Sachs spacetime

Resolution of singularities in the Kantowski–Sachs model due to non-perturbative quantum gravity effects is investigated. Using the effective spacetime description for the improved dynamics version of loop quantum Kantowski–Sachs spacetimes, we show that even though expansion and shear scalars are universally bounded, there can exist events where curvature invariants can diverge. However, such events can occur only for very exotic equations of state when pressure or derivatives of energy density with respect to triads become infinite at a finite energy density. In all other cases curvature invariants are proved to remain finite for any evolution in finite proper time. We find the novel result that all strong singularities are resolved for arbitrary matter. Weak singularities pertaining to above potential curvature divergence events can exist. The effective spacetime is found to be geodesically complete for particle and null geodesics in finite time evolution. Our results add to a growing evidence for generic resolution of strong singularities using effective dynamics in loop quantum cosmology by generalizing earlier results on isotropic and Bianchi-I spacetimes.

Generic Adaptive Resolution Method for Reverse Mapping of Polymers from Coarse-Grained to Atomistic Descriptions.

In this paper, we propose a new generic approach for reverse mapping from coarse-grained to atomistic scale based on the adaptive resolution scheme (AdResS). In AdResS simulation, two spatial domains, modeled at two different scales, are brought together in a concurrent simulation by defining a hybrid region where particles can switch representation from one model to another. We use AdResS as a central part of a reverse mapping algorithm from a different perspective by treating the whole simulation box as a hybrid region and changing the resolution as a function of time during the course of a molecular dynamics simulation. The proposed method depends only on a single parameter that controls the reverse mapping process and it is independent of atomistic and coarse-grained force-fields. We performed a reverse mapping of three different systems, simple molecules (dodecane), polymer chains (polyethylene) and ring molecules (trimethylol melamine) with a degree of coarse-graining ranging from two to ten heavy atoms. The conformational and dynamical properties of the reconstructed systems are in excellent agreement with the reference atomistic simulation.

Is classical flat Kasner spacetime flat in quantum gravity?

Quantum nature of classical flat Kasner spacetime is studied using effective spacetime description in loop quantum cosmology (LQC). We find that even though the spacetime curvature vanishes at the classical level, nontrivial quantum gravitational effects can arise. For the standard loop quantization of Bianchi-I spacetime, which uniquely yields universal bounds on expansion and shear scalars and results in a generic resolution of strong singularities, we find that a flat Kasner metric is not a physical solution of the effective spacetime description, except in a limit. The lack of a flat Kasner metric at the quantum level results from a novel feature of the loop quantum Bianchi-I spacetime: quantum geometry induces nonvanishing spacetime curvature components, making it not Ricci flat even when no matter is present. The noncurvature singularity of the classical flat Kasner spacetime is avoided, and the effective spacetime transits from a flat Kasner spacetime in asymptotic future, to a Minkowski spacetime in asymptotic past. Interestingly, for an alternate loop quantization which does not share some of the fine features of the standard quantization, flat Kasner spacetime with expected classical features exists. In this case, even with nontrivial quantum geometric effects, the spacetime curvature vanishes. These examples show that the character of even a flat classical vacuum spacetime can alter in a fundamental way in quantum gravity and is sensitive to the quantization procedure.

Ecological and genetic variation in reef-building corals on four Society Islands

We quantified benthic community structure on shallow (10 m isobath) reefs separated by 3–130 km on four islands in the south Pacific, and evaluated the roles of disturbances vs. coral recruitment as causes of spatial heterogeneity. Reefs were surveyed in 2013 on Moorea, Tahiti, Tetiaroa, and Maiao, with community structure sampled at two sites on each island using photoquadrats. The effects of coral recruitment on population structure were evaluated through genetic analyses of Pocillopora on three of the islands. Benthic community structure with functional group resolution differed among islands and generally among sites, but coral community structure (generic resolution) differed among islands, but generally not among sites. Genetic analyses of Pocillopora using the open reading frame of host mtDNA revealed varying relative abundances of Pocillopora meandrina/Pocillopora eydouxi, Pocillopora verrucosa, Pocillopora effuses, and two unnamed haplotypes on each island. These results suggest that corals on each island represent unique samplings of genetically discrete larval assemblages rather than random samplings of a single larval assemblage. Together, our findings emphasize the extent to which coral community structure varies over a scale of <200 km, and suggests that recruitment from spatially discrete pools of coral larvae plays an important role in creating spatial variation in community structure, even where reefs are connected by prevailing currents.

Differential distribution of octocorals and scleractinians around St. John and St. Thomas, US Virgin Islands

While the decline in cover of scleractinian corals on Caribbean reefs is well known, little attention has been paid to other taxa that might covary in abundance. This study focused on octocorals around St. John and St. Thomas, US Virgin Islands, in order to: (1) describe variation in octocoral communities, (2) test for similarity in distribution of octocorals and scleractinians, and (3) identify factors associated with the distribution of octocorals that have value in understanding how reefs will change in the future. Photoquadrats recorded in 2011 on north and south shores were used to quantify octocoral and scleractinian abundance with generic resolution. MDS and PERMANOVA revealed clearer community variation relative to the spatial scales of investigation for octocorals compared to scleractinians. Multivariate spatial structuring for octocorals differed from that of scleractinians, suggesting the taxa responded in dissimilar ways to the environmental conditions. PCO supported the differences in the structuring of community types and revealed the roles of octocorals (Eunicea, Briareum, Plexaurella, Muriceopsis, Pterogorgia, and Muricea) in distinguishing among islands, shores, and sites; scleractinians (Porites, Colpophyllia, Siderastrea, and Orbicella) distinguished sites. These results suggest that changes in the community structure of Caribbean reefs favoring octocorals may promote local-scale provincialization.

The Potential of High-throughput Metagenomic Sequencing of Aquatic Bacterial Communities to Estimate the Postmortem Submersion Interval.

Human remains can be discovered in freshwater or marine ecosystems, circumstances where insects and other invertebrates have infrequently been used for understanding the time of postmortem submersion. In this study, the identification and succession of epinecrotic bacterial communities on vertebrate remains were described during decomposition in a temperate headwater stream during two seasons (summer and winter). Bacterial communities were characterized with 454 pyrosequencing and analyzed at phyletic and generic taxonomic resolutions. There was a significant increase in genera richness over decomposition during both seasons. Additionally, multivariate statistical modeling revealed significant differences in bacterial communities between seasons at both taxonomic resolutions and siginificant genera differences among sampling days within each season, suggesting a succession of these communities. These data are the first to describe aquatic bacterial succession using high-throughput metagenomic sequencing on vertebrate remains submerged in a freshwater habitat, and provide initial evidence for their potential use in forensic investigations.

Assessing the HLA diversity of cord blood units collected from a birth clinic caring for pregnant women in an ethnically diverse metropolitan area

New strategies are emerging in cord blood banking where focusing on birth clinics caring for a high number of mothers belonging to ethnic minorities could offer new possibilities for allotransplantation both for patients of European origin and for patients from ethnic minorities or mixed ancestries. Marseilles Cord Blood Bank works with one university birth clinic caring for a culturally and sociologically diverse population. Stringent French legal restrictions apply to recording the geographic origin of parents. To circumvent this limitation and evaluate the contribution of newly banked cord blood units (CBUs) to increasing HLA diversity, we applied an algorithm that allows for the determination of parents' putative haplotypes and thus grossly deduce information on their ancestry. Generic resolution HLA-A, HLA-B, and allelic resolution HLA-DRB1 genotyping for 328 CBUs and 2691 unrelated donors (UDs) between January 2009 and May 2012 were performed. Enrichment from international CBU registry with nonreferenced generic HLA-A, HLA-B, and allelic HLA-DRB1 phenotypes was compared between CBUs identified with one or two non-European haplotypes and CBUs identified with two European haplotypes. Marseilles CBUs display an increased proportion of HLA antigens frequently expressed in African populations compared to UDs. Whereas 93% of 199 CBUs identified with one or two non-European haplotypes enrich international CBU registry, this result is reduced to 42% for the 129 CBUs identified with two European haplotypes. This study supports a new method to assess HLA diversity. However, such an increased of HLA diversity raises questions about frequencies of CBUs released and clinical relevance from their uses.

Context-based person identification framework for smart video surveillance

Smart video surveillance (SVS) applications enhance situational awareness by allowing domain analysts to focus on the events of higher priority. SVS approaches operate by trying to extract and interpret higher "semantic" level events that occur in video. One of the key challenges of SVS is that of person identification where the task is for each subject that occurs in a video shot to identify the person it corresponds to. The problem of person identification is especially challenging in resource-constrained environments where transmission delay, bandwidth restriction, and packet loss may prevent the capture of high-quality data. Conventional person identification approaches which primarily are based on analyzing facial features are often not sufficient to deal with poor-quality data. To address this challenge, we propose a framework that leverages heterogeneous contextual information together with facial features to handle the problem of person identification for low-quality data. We first investigate the appropriate methods to utilize heterogeneous context features including clothing, activity, human attributes, gait, people co-occurrence, and so on. We then propose a unified approach for person identification that builds on top of our generic entity resolution framework called RelDC, which can integrate all these context features to improve the quality of person identification. This work thus links one well-known problem of person identification from the computer vision research area (that deals with video/images) with another well-recognized challenge known as entity resolution from the database and AI/ML areas (that deals with textual data). We apply the proposed solution to a real-world dataset consisting of several weeks of surveillance videos. The results demonstrate the effectiveness and efficiency of our approach even on low-quality video data.

Bianchi-I spacetimes in loop quantum cosmology: physics of singularity resolution

Quantum geometry effects in loop quantum cosmology are known to resolve various singularities in the isotropic and anisotropic models. Previous investigations have shown that singularity resolution is tied to boundedness of physical quantities such as the energy density and the expansion and shear scalars in the spacetime. Using effective dynamics, we show that these do not necessarily lead to a generic boundedness of spacetime curvature in the Bianchi-I model and find the potential possibilities where the curvature invariants can diverge. These include cases where the pressure of the matter content diverges at a finite volume and energy density. By analyzing the strength of singularities, we show that such pressure singularities are weak. All known types of strong singularities of the classical theory are resolved. This analysis brings us closer to generalize the results on generic resolution of singularities in the isotropic models in loop quantum cosmology, to the anisotropic spacetimes.

HiRE-RNA: A High Resolution Coarse-Grained Energy Model for RNA

Although RNAs play many cellular functions, the gap between their sequences and 3D structures is increasing and our knowledge of RNA thermodynamics and long time scale dynamics is still limited at an atomic level of detail. In principle, all-atom molecular dynamics (MD) and replica exchange molecular dynamics (REMD) simulations can investigate these issues, but with current computer facilities, these simulations in explicit solvent have been limited to small RNAs and to short times. To move to larger systems, we can resort to coarse-graining. In this study, we present HiRE-RNA, a generic high resolution coarse-grained model for RNA, and report MD and REMD simulations on two RNAs of 22 and 36 nucleotides. Starting from unfolded structures, the 22-mer folds within 1.8 A rmsd from the NMR structure, while the 36-mer folds within 4.6 A rmsd. Current results suggest that further optimization of the HiRE-RNA force field should open the door to a relevant model for studying large RNAs, such as riboswitches, and for predicting 3D structures from secondary structure information.

EFFECTS OF DATA CATEGORIZATION ON PALEOCOMMUNITY ANALYSIS: A CASE STUDY FROM THE PENNSYLVANIAN FINIS SHALE OF TEXAS

Paleocommunity research efforts have explored a multitude of faunal assemblages using a wide range of sampling and analytical methods to infer a paleoecological signal. Here, we derive six secondary datasets from a single stratigraphic series of faunal assemblages in the Finis Shale (Pennsylvanian) of Jacksboro, Texas, USA, using a variety of data categorization decisions (i.e., abundance versus calcified biomass, all taxa versus selected indicator taxa, and generic versus higher clade resolution). Biomass- and abundance-derived datasets were not significantly different in terms of evenness, Shannon’s information index, or Simpson’s diversity index. Using Bray-Curtis and nonmetric multidimensional scaling ordinations, with Sorenson and relative Sorenson distance measures, ordination axis scores of the six derived datasets were all significantly correlated with one another, suggesting little difference in their respective paleoecological signals. Three potential explanations for this consistent paleoecological signal, regardless of which data categorizations are employed, include: (1) the dominance of a few brachiopod taxa overwhelmingly influenced the community structure, (2) relatively constrained environmental conditions limited community variation, and (3) low variation in specimen size minimized potential differences among abundance and calcified biomass categorizations. We suggest that other datasets with greater diversities, greater evenness, or from a wider range of paleoenvironments might not show this consistency. Thus, to the degree possible and appropriate, paleoecological investigators should test the effects of these data categorization decisions on a paleoecological signal, regardless of the analytical method employed.

Are loop quantum cosmos never singular?

A unified treatment of all known types of singularities for flat, isotropic and homogeneous spacetimes in the framework of loop quantum cosmology (LQC) is presented. These include bangs, crunches and all future singularities. Using effective spacetime description we perform a model-independent general analysis of the properties of curvature, behavior of geodesics and strength of singularities. For illustration purposes a phenomenological model based analysis is also performed. We show that all values of the scale factor at which a strong singularity may occur are excluded from the effective loop quantum spacetime. Further, if the evolution leads to either a vanishing or divergent scale factor then the loop quantum universe is asymptotically deSitter in that regime. We also show that there exists a class of sudden extremal events, which includes a recently discussed possibility, for which the curvature or its derivatives will always diverge. Such events however turn out to be harmless weak curvature singularities beyond which geodesics can be extended. Our results point toward a generic resolution of physical singularities in LQC.

Generic entity resolution with negative rules

Entity resolution (ER) (also known as deduplication or merge-purge) is a process of identifying records that refer to the same real-world entity and merging them together. In practice, ER results may contain "inconsistencies," either due to mistakes by the match and merge function writers or changes in the application semantics. To remove the inconsistencies, we introduce "negative rules" that disallow inconsistencies in the ER solution (ER-N). A consistent solution is then derived based on the guidance from a domain expert. The inconsistencies can be resolved in several ways, leading to accurate solutions. We formalize ER-N, treating the match, merge, and negative rules as black boxes, which permits expressive and extensible ER-N solutions. We identify important properties for the rules that, if satisfied, enable less costly ER-N. We develop and evaluate two algorithms that find an ER-N solution based on guidance from the domain expert: the GNR algorithm that does not assume the properties and the ENR algorithm that exploits the properties.

Avoidance of future singularities in loop quantum cosmology

We consider the fate of future singularities in the effective dynamics of loop quantum cosmology. Nonperturbative quantum geometric effects which lead to ${\ensuremath{\rho}}^{2}$ modification of the Friedmann equation at high energies result in generic resolution of singularities whenever energy density $\ensuremath{\rho}$ diverges at future singularities of Friedmann dynamics. Such quantum effects lead to the avoidance of a big rip, which is followed by a recollapsing universe stable against perturbations. Resolution of sudden singularity, the case when pressure diverges but energy density approaches a finite value depends on the ratio of the latter to a critical energy density of the order of the Planck value. If the value of this ratio is greater than unity, the universe escapes the sudden future singularity and becomes oscillatory.

Faking It: Female Virginity and Pamela's Virtue

Faking It: Female Virginity and Pamela's Virtue Corrinne Harol "Female Chastity is, in its own Nature, built upon avery ticklishFoundation."1 Samuel Richardson's sentimental novel Pamela (1740) revolves around the repeated attempts ofthe aristocratic Mr B. to rape his servant, the exemplarily virginal Pamela. Mr B.'s pursuit ofPamela's body instigates the narrative, but the objective of the novel is the loftier (by its own standards) investigation of Pamela's interiority.2 The narrative action converts Mr B. from an admirer of Pamela's body into an acolyte ofher virtue and thus relocates feminine social value from virginity (and embodiment) to virtue (and interiority) . Epistemological dilemmas catalyse this shift from virginity to virtue and transform the narrative from a rape plot to a marriage plot Though the epistemological problems presented by Pamela's virginal body do not at first appear crucial to Pamela, they nonetheless shape the epistemological crisis—and generic resolution of mat crisis— 1 [Bernard de Mandeville?], A Modest Defense ofPublick Stews; or, An Essay upon Wlioring, as it is nowpractic'd in theseKingdoms. Written by a Layman (London, 1724), p. 49. 1 would like to thank the following people for dieir generous comments on earlier versions ofdiis article: Helen Deutsch, Jayne Lewis, Felicity Nussbaum, Leilani Riehle, Maeera Schreiber, and Barry Weiler. 2 Samuel Richardson, Pamela; or, Virtue Rewarded (1740; reprint, London: Penguin, 1980). References are to diis edition. EIGHTEENTH-CENTURY FICTION, Volume 16, Number 2,January 2004 198 EIGHTEENTH-CENTURY FICTION around Pamela's virtue. Because ofits inconstant materiality, virginity presented a particular kind of epistemological problem during the era of the scientific revolution that constitutes an important context for Pamela. The hymen—a corporeal entity with a long-debated existence, which disappears as it reveals itselfand which is found only in a limited class of bodies (virgin women) and only in some nondeterminable subset ofthem—resists the kinds ofmaterial investigation called for by the new science. The very immateriality ofvirtue, by contrast, creates an altogether different kind of epistemological quandary in Pamela. Pamela's virtue, so unexpectedly extravagant for a servant girl, must be produced and proven for a sceptical audience that includes Mr B. and the reader. Pamela's epistolary accounts of her heroic attempts to preserve hervirginity produce evidence about her interiority and thus allow readers to evaluate her "virtue." While her virtue depends upon preservation of her virginity (while she remains unmarried), it ultimately transcends physicality: her virtue comes to represent the intangible qualities that make her suitable for the wildly implausible hypergamous marriage with Mr B. Scholars have long acknowledged that Pamela is obsessed with virginity and that epistemological uncertainty is endemic to its form, but no one has persuasively linked the two obsessions in the novel: virginity and proof.3 Other critics have argued that novels absorbed scientific discourse, but this article argues that the generic strategies ofPamela and its authentication ofinteriority result from the failure of scientific methods. Whereas the virgin female body confronts science with the limitations ofits methods, Pamela's virtue, paradoxically , proves more amenable to emergent epistemological standards 3 For more on the epistemological issues in Pamela, seeJohn Stevenson, "'Never in a Vile House': Knowledge and Experience in Richardson," Literature and Psychology 34 (1988), pp. 4-16; John Pierce, "Pamela's Textual Authority," Eighteenth-Century Fiction 7 (1995), 131-46; NancyArmstrong, Desire andDomesticFiction:A PoliticalHistory oftlieNovel (Oxford: Oxford University Press, 1987), pp. 108-34; Michael McKeon, Vie Origins oftlieEnglish Novel 1600-1 740 (Baltimore and London:Johns Hopkins University Press, 1987), pp. 357-380. Ann Van Sant's discussion ofthe "testing" ofClarissa by Lovelace is an important influence on the argument presented in this article, Eighteenth-Century Sensibility and the Novel (Cambridge: Cambridge University Press, 1993). April Alliston (discussed below) links virginity to the epistemological strategies ofthe early novel, saying "die trudi about female sexual conduct ... remains the ultimate truth for fiction in France and England." "Female Sexuality and the Referent ofEnlightenment Realisms," Spectacles ofRealism: Body, Gender, Genre, ed. Margaret Cohen and Christopher Prendergast (Minneapolis and London: University ofMinnesota Press, 1995), p. 19. FAKING IT199 than physical virginity.4 From this perspective, the heralded move of the novel towards psychological and moral investigation—and...

Enhancing regulatory effectiveness by improving the process for identifying and resolving generic issues

The Generic Issues Program first began formally in response to a Commission directive in October of 1976. In 1983, it became one of the first programs to make successful use of probabilistic risk information to aid in regulatory decision-making. In the 16 years since the program became quantitative, 836 issues have been processed. Of these, 106 reactor safety issues were prioritized as requiring further evaluation to determine the final resolution. Approximately a dozen generic issues remain unresolved. Although there is far less reactor licensing activity than in the 1970s, new issues continue to be identified from research and operational experience. These issues often involve complex and controversial questions of safety and regulation, and an efficient and effective means of addressing these issues is essential for regulatory effectiveness. Issues that involve a significant safety question require swift, effective, enforceable, and cost-effective regulatory actions. Issues that are of little safety significance must be quickly shown to be so and dismissed in an expeditious manner so as to avoid unnecessary expenditure of limited resources and to reduce regulatory uncertainty. Additionally, in the time since the generic issue program began, probabilistic risk assessment techniques have advanced significantly while agency resources have continued to diminish. Accordingly, the paper discusses the steps that have been taken to enhance the effectiveness and efficiency of the generic issue resolution process. Additionally, four resolved issues are discussed, along with key elements of a proposed new procedure for resolving potential generic issues.

Resolutions of subsets of finite sets of points in projective space

Given a finite setX, of points in projective space for which the Hilbert function is known, a standard result says that there exists a subset of this finite set whose Hilbert function is"as big as possible"inside X. Given a finite set of points in projective space for which the minimal free resolution of its homogeneous ideal is known, what can be said about possible resolutions of ideals of subsets of this finite set? We first give a maximal rank type description of the most generic possible resolution of a subset. Then we show, via two very different kinds of counterexamples, that this generic resolution is not always achieved. However, we show that it is achieved for sets of points in projective two space: given any finite set of points in projective two space for which the minimal free resolution is known, there must exist a subset having the predicted resolution.

A Framework for Nonviolence and Peacebuilding in Islam

Today, there is little debate that a paradigm shift is occurring in the field of international conflict resolution; where experts laud the effectiveness of peaceful means ending disputes compared with the use of force or violence. This paradigm shift is reflected in the increasing number of peacebuilding academic and applied programs in Eastern Europe, Latin America, Africa, South and East Asia, and the Middle East, including conflict resolution workshops, projects for building civil societies, and nonviolent resistance mobilization. In peacebuilding contexts, scholars and practitioners are seeking to integrate authentic, indigenous and local cultural methods of conflict analysis and intervention, which are replacing the generic conflict resolution applications developed by western practitioners in United States and Europe.

Learning to detect and avoid run-time feature interactions in intelligent networks

The Intelligent Network (IN) allows rapid changes in the services provisioned and their functionality. Services may be supplied by different service providers, making it unlikely that all service specifications will be available for examination by any single agency. Approaches to handle feature interaction problems must be able to operate within these constraints. Work by the authors has produced a generic run time feature interaction manager (FIM) concept to manage feature interactions in a live network. It monitors features as black boxes, learns their correct behavior and uses this to determine when feature interactions have occurred. The paper describes and compares experiences using three different techniques to realize the proposed approach. These are: state sequence monitoring, artificial neural networks (ANN), and rule based monitoring which also includes integrated generic resolution approaches. The paper explores the design alternatives with the various techniques, and reports on the results obtained from experimentation.

Effects of Asphaltene Solvency on Stability of Water-in-Crude-Oil Emulsions

The formation of stable and persistent emulsions and foams in the production and refining of crude petroleum is a challenge which has defied broad and generic resolution for several decades. Rational and systematic approaches to demulsification have been slow to develop due to a lack of fundamental understanding of the molecular origins of emulsion stabilization and the full range of factors which govern emulsion stability. Several studies have shown the importance of resins and asphaltenes, which have the ability to organize and form rigid films at the oil/water interface. We have developed a molecular model in which we propose that the integrity of these films and thus their ability to stabilize water-in-crude-oil emulsions are sensitive to a variety of crude solvency parameters, such as aromaticity, resin-to-asphaltene ratio, and polar functional group concentration. This model was tested by correlating the stability of emulsions formed from a variety of crude oils—Arab Berri (Extra Light), Arab Heavy, Alaska North Slope, and San Joaquin Valley—in which the resin and asphaltene contents vary, as well as their specific characteristics. The results of the elemental and functional group characterization of these crudes and their fractions and the techniques utilized to obtain them were presented previously. Detailed quantitative protocols for gauging relative emulsion stability have been developed to further evaluate the proposed model by blending solvents of varying aromaticity and by doping isolated resins from different crudes into solvent-modified crudes. Dramatic destabilization of emulsions was accomplished by modifying the crude solvency in either fashion. Simple physical and chemical techniques for minimizing emulsion formation such as basic crude blending and solvent-recycle schemes will also be discussed.