Concurrent Ones Research Articles

Phylogenetics and the Cenozoic radiation of lampreys

The development of a movable jaw is one of the most important transitions in the evolutionary history of animals.1 Jawed vertebrates rapidly diversified after appearing approximately 470 million years ago. Today, only lampreys and hagfishes represent the once dominant jawless grade2,3,4 and comprise less than 1% of living vertebrate species. Their relationship to other vertebrates ranks among the more contentious problems in animal phylogenetics.5,6,7,8,9,10,11,12 Further, the phylogenetic relationships within lampreys and hagfishes remain unclear,13,14,15 and the ages of their living lineages are largely unexplored.16,17 Because of their importance for the genomic and developmental changes that prefigured jawed vertebrate diversity,18,19,20,21 the evolutionary history of lampreys and hagfishes is a major frontier of organismal biology. Of these two clades, lampreys22 are more ecologically diverse, exhibiting freshwater, anadromous, and fully marine forms, as well as parasitic and nonparasitic species.23,24 Here, we present a new phylogeny and historical biogeographic reconstruction of all living lampreys. Whereas the early diversification of this clade tracks Pangaean fragmentation, lampreys also rapidly radiated in the northern hemisphere during the mid-Cretaceous and directly after the Cretaceous-Paleogene extinction. These radiations mirrored concurrent ones in other animals and plants and coincided with changes to lamprey ecology and feeding behavior. Our results suggest that 80% of living lamprey clades appeared in the last 20 million years of Earth history. Rather than gradually accumulating since the oldest stem-group forms appeared in the early Paleozoic, living lamprey biodiversity results from diversifications extending from the Cretaceous to present.

Do we parse the background into separate streams in the cocktail party?

In the cocktail party situation, people with normal hearing usually follow a single speaker among multiple concurrent ones. However, there is no agreement in the literature as to whether the background is segregated into multiple streams/speakers. The current study varied the number of concurrent speech streams and investigated target detection and memory for the contents of a target stream as well as the processing of distractors. A male-voiced target stream was either presented alone (single-speech), together with one male-voiced distractor (one-distractor), or a male- and a female-voiced distractor (two-distractor). Behavioral measures of target detection and content tracking performance as well as target- and distractor detection related event-related brain potentials (ERPs) were assessed. We found that the N2 amplitude decreased whereas the P3 amplitude increased from the single-speech to the concurrent speech streams conditions. Importantly, the behavioral effect of distractors differed between the conditions with one vs. two distractor speech streams and the non-zero voltages in the N2 time window for distractor numerals and in the P3 time window for syntactic violations appearing in the non-target speech stream significantly differed between the one- and two-distractor conditions for the same (male) speaker. These results support the notion that the two background speech streams are segregated, as they show that distractors and syntactic violations appearing in the non-target streams are processed even when two speech non-target speech streams are delivered together with the target stream.

Dual Mandates in Chinese Congresses: Information and Cooptation

Survey data suggest that a high proportion of Chinese congress delegates sit concurrently in two or more congresses. While dual mandates are not unusual in democracies, the literature has failed to notice their existence in China, let alone theorize or analyze them. We turn to the political science literature on assemblies under authoritarianism to guide our analysis of survey data for 3,008 county congress delegates, half of whom are concurrent ones. We show that dual mandates amplify some voices and not others in ways consistent with two perspectives in the literature. Dual mandates amplify information from citizens at the grassroots upward toward governments: More delegates with deep community roots representing poor, rural, remote districts sit concurrently in county and lower-level congresses. Dual mandates also coopt influential groups posing a potential challenge to ruling party power: They amplify the influence of private entrepreneurs, more of whom sit concurrently in county and prestigious higher-level congresses.

Fatigue Assessment of Selective Laser Melted Ti-6Al-4V: Influence of Speed Manufacturing and Porosity

Additive Manufacturing represents a promising technology as an alternative to the conventional manufacturing process, with rapid and economic product development, as well as a significant weight reduction and a freeform design. Although the mechanical properties of additively manufactured metals, such as the Ti-6Al-4V alloy, are well-established, a complete understanding of the fatigue performance is still a pending aspiration due to its inherent stochastic complexity and the influence of several manufacturing factors. This paper presents a study of the influence of speed manufacturing and porosity in the fatigue behaviour of a Ti-6Al-4V alloy. To this aim, a numerical simulation of the expected porosity at different laser velocities is performed, together with a simulation of the residual stresses. These numerical results are compared with experimental measurements of residual stresses and a qualitative analysis of the porosities. Then, fatigue strength is experimentally obtained for two different laser speeds and fitted by a probabilistic model. As a result, the probabilistic S–N fields for different laser velocities are found to be similar, with scatter bands nearly coincident, drawing the conclusion that this effect is negligible in comparison with other concurrent ones, such as roughness or surface defects from manufacturing conditions, promoting crack initiation and premature fatigue failure.

M-CHAT-R/F Validation as a screening tool for early detection in children with autism spectrum disorder.

Screening for Autism Spectrum Disorders (ASD) using the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) increases early detection, allowing early interventions and improving prognosis. This tool is part of the management in case of suspected ASD in several clinical guidelines. The objective of this article was to conduct the concurrent and discrimi nant validation and the reliability analysis of M-CHAT-R/F in the Chilean population. This is the second stage of the cross-cultural adaptation of cross-sectional design. M-CHAT- R/F was applied to a sample of 20 children with suspected ASD and 100 randomly selected healthy control children, aged between 16-30 months. Autism Diagnostic Observation Schedule (ADOS-2), considered as reference, was applied to the 20 patients of the clinical sample, to 20 children of the healthy control sample and to those cases of the healthy control sample with M-CHAT-R/F positive. Cronbach alpha was calculated, as well as M-CHAT-R/F and ADOS-2 correlation, sensitivity, and specificity analyses. In the healthy sample, M-CHAT-R/F was positive in two patients, with one of them positive and the other one negative for ASD with ADOS-2 test. In the clinical sample, M- CHAT-R/F was positive in all cases, three of them were negative in the ADOS-2 test. The Alfa relia bility of M-CHART-R/T was 0,889, the discriminant sensitivity and specificity were 100% and 98%, and the concurrent ones were 100% and 87.5% respectively. The Chilean M-CHAT- R/F version was reliable, sensitive and specific, similar to the original test, which opens the possibility for its use in clinical samples and for research. Validating M-CHAT-R/F is an ongoing process which must be further developed.

Attention and speech-processing related functional brain networks activated in a multi-speaker environment.

Human listeners can focus on one speech stream out of several concurrent ones. The present study aimed to assess the whole-brain functional networks underlying a) the process of focusing attention on a single speech stream vs. dividing attention between two streams and 2) speech processing on different time-scales and depth. Two spoken narratives were presented simultaneously while listeners were instructed to a) track and memorize the contents of a speech stream and b) detect the presence of numerals or syntactic violations in the same (“focused attended condition”) or in the parallel stream (“divided attended condition”). Speech content tracking was found to be associated with stronger connectivity in lower frequency bands (delta band- 0,5–4 Hz), whereas the detection tasks were linked with networks operating in the faster alpha (8–10 Hz) and beta (13–30 Hz) bands. These results suggest that the oscillation frequencies of the dominant brain networks during speech processing may be related to the duration of the time window within which information is integrated. We also found that focusing attention on a single speaker compared to dividing attention between two concurrent speakers was predominantly associated with connections involving the frontal cortices in the delta (0.5–4 Hz), alpha (8–10 Hz), and beta bands (13–30 Hz), whereas dividing attention between two parallel speech streams was linked with stronger connectivity involving the parietal cortices in the delta and beta frequency bands. Overall, connections strengthened by focused attention may reflect control over information selection, whereas connections strengthened by divided attention may reflect the need for maintaining two streams in parallel and the related control processes necessary for performing the tasks.

Slime Mould Games Based on Rough Set Theory

Abstract We define games on the medium of plasmodia of slime mould, unicellular organisms that look like giant amoebae. The plasmodia try to occupy all the food pieces they can detect. Thus, two different plasmodia can compete with each other. In particular, we consider game-theoretically how plasmodia of Physarum polycephalum and Badhamia utricularis fight for food. Placing food pieces at different locations determines the behavior of plasmodia. In this way, we can program the plasmodia of Physarum polycephalum and Badhamia utricularis by placing food, and we can examine their motion as a Physarum machine-an abstract machine where states are represented as food pieces and transitions among states are represented as movements of plasmodia from one piece to another. Hence, this machine is treated as a natural transition system. The behavior of the Physarum machine in the form of a transition system can be interpreted in terms of rough set theory that enables modeling some ambiguities in motions of plasmodia. The problem is that there is always an ambiguity which direction of plasmodium propagation is currently chosen: one or several concurrent ones, i.e., whether we deal with a sequential, concurrent or massively parallel motion. We propose to manage this ambiguity using rough set theory. Firstly, we define the region of plasmodium interest as a rough set; secondly, we consider concurrent transitions determined by these regions as a context-based game; thirdly, we define strategies in this game as a rough set; fourthly, we show how these results can be interpreted as a Go game.

Fair bandwidth allocating and strip-aware prefetching for concurrent read streams and striped RAIDs in distributed file systems

With a striped RAID (Redundant Array of Independent Disks) which consists of multiple disks and spreads data across them in parallel, distributed file systems (DFSs) easily enhance the performance of a single read stream (i.e., a series of sequential reads by a process). However, most existing DFSs suffer from performance degradation in concurrent read streams (i.e., multiple series of sequential reads by concurrent processes). Furthermore, research on the performance of concurrent ones for a striped RAID in DFSs has been rarely reported so far. In this paper, we define the problems that degrade it at different configurations of striped RAIDs, and resolve them by proposing the following two methods: (1) a fair allocating of network bandwidth for concurrent read streams and (2) a strip-aware prefetching for each individual read stream. We show that our proposal outperforms all the existing DFSs by at least two times for all kinds and configurations of striped RAIDs. Furthermore, the performance gap between our proposal and the existing DFSs becomes wider according to the increasing number of striped disks.

VARIANTS OF ADRENAL MYELOLIPOMAS AND RARE CONCOMITANT DISEASES

Background: Adrenal myelolipoma is a rare tumor, etiology and pathogenesis of which aren’t completely defined. Intensified investigation of the tumor structural components in concomitant adrenal lesions and associated diseases enables more comprehensive discovery of its histogenesis features and more adequate assessment of the cause of different correlations between adipose and hemopoietic components of the tumor. Aim: Specification of the structural features of different variants of adrenal myelomas based on the analysis of the outcome of this tumor morphologic study including possible influence of associated diseases. Materials and methods: A total of 16 observations of adrenal myelolipomas are presented in the study including 11 “pure” tumors, 2 mixed (adenomas/myelolipomas), and 3 concurrent ones (adenoma and myelolipoma). Results: Correlation between hemopoietic elements and adipose tissue varies in both “pure” myelolipoma and combined adrenal tumor. Cavernous spleen hemangioma, accompanied by destruction of hemopoietic cells, gastrointestinal stromal tumor, and Hailey-Hailey disease, all based on genetic mutations, are rare concomitant diseases in adrenal myelolipoma. Conclusion: Myelolipoma tumorogenesis depends not only on concomitant pathology in adrenal gland but also on myelolipoma association with diseases stimulating histogenesis of both fatty cells and hemopoietic elements.

Blind source separation and feature extraction in concurrent control charts pattern recognition: Novel analyses and a comparison of different methods

Control charts are among the main tools in statistical process control (SPC) and have been extensively used for monitoring industrial processes. Currently, besides the single control charts, there is an interest in the concurrent ones. These graphics are characterized by the simultaneous presence of two or more single control charts. As a consequence, the individual patterns may be mixed, hindering the identification of a non-random pattern acting in the process; this phenomenon is refered as concurrent charts. In view of this problem, our first goal is to investigate the importance of an efficient separation step for pattern recognition. Then, we compare the efficiency of different Blind Source Separation (BSS) methods in the task of unmixing concurrent control charts. Furthermore, these BSS methods are combined with shape and statistical features in order to verify the performance of each one in pattern classification. In additional, the robustness of the better approach is tested in scenarios where there are different non-randomness levels and in cases with imbalanced dataset provided to the classifier. After simulating different patterns and applying several separation methods, the results have shown that the recognition rate is widely influenced by the separation and feature extraction steps and that the selection of efficient separation methods is fundamental to achieve high classification rates.

“General Heads,” Great Minds, and the Genesis of Scientific Racism

General Heads, Great Minds, and Genesis of Scientific Racism ROBIN RUNIA Cristina Malcolmson. Studies of Skin Color in Early Royal Society: Boyle, Cavendish, Swift. Burlington, VT: Ashgate, 2013. 233 pages. $85.00.It is commonly presum'd that Heat of Climate wherein they live, is reason, why so many Inhabitants of Scorching Regions of Africa are Black; and there is this familiar Observation to Countenance this Conjecture, That we plainly see that Mowers, Reapers, and other Countreypeople, who spend most part of Hot Summer dayes expos'd to Sun, have skin of their Hands and Faces, which are parts immediately Expos'd to Sun and Air, made of a Darker Colour than before, and consequently tending to Blackness; And Contrarywise we observe that Danes and some other people that Inhabit Cold Climates, and even English who feel not so Rigorous a Cold, have usually Whiter faces than Spaniards, Portugalls and other European Inhabitants of Hotter Climates. But this Argument I take to be far more Specious than Convincing. (153-54)There is another Opinion concerning Complexion of Negroes, that... Blackness of Negroes [is] an effect of Noah's Curse ratify'd by God's, upon Cham; But though I think that even a Naturalist may without disparagement believe all Miracles attested by Holy Scriptures, yet in this case to flye to a Supernatural Cause, will, I fear, look like Shifting off Difficulty, instead of Resolving it; for we enquire not First and Universal, but Proper, Immediate, and Physical Cause of Jetty Colour of Negroes; And not only we do not find expressed in Scripture, that Curse meant by Noah to Cham, was Blackness of his Posterity, but we do find plainly enough there that Curse was quite another thing, namely that he should be a Servant of Servants, that is by an Ebraism, a very Abject Servant to his Brethren.... Nor is it evident that Blackness is a Curse, for Navigators tell us of Black Nations, who think so much otherwise of their own condition, that they paint Devil White. Nor is Blackness inconsistent with Beauty, which even to our European Eyes consists not so much in Colour, as an Advantageous Stature, a Comely Symmetry of parts of Body, and Good Features in Face. So that I see not why Blackness should be thought such a Curse to Negroes, unless perhaps it be, that being wont to go Naked in those Hot Climates, Colour of their Skin does probably, according to Doctrine above deliver'd, make Sunbeams more Scorching to them, than they would prove to a people of a White Complexion. (159-60)Greater probability there is, That Principal Cause (for I would not exclude all concurrent ones) of Blackness of Negroes is some Peculiar and Seminal Impression. ( 161)-Robert Boyle, Experiments and Considerations Touching Colours ( 1664)The above extracts present Robert Boyle's delineation of racialized difference, as produced and evaluated by Royal Society; this delineation, production, and evaluation is lifeblood of Cristina Malcolmson's Studies of Skin Color in Royal Society. Exploring development of modern notion of race within context of colonialism, Malcolmson argues that the attention to skin color in Royal Society allowed racialization to develop and eventually flourish within practices of new science (7). Specifically, attention to imbrication of this process within institutional and economic commitments to British imperial dominance helps to fill in gaps between an attention to skin color, consideration of its causes, and dehumanization and subjugation of non-European individuals. Malcolmson's focus on Royal Society's activities and publications and on Margaret Cavendish's and Jonathan Swift's reactions to them provides an important and nuanced contri- bution to recent scholarship in this area as well as a call for additional work to be done. …

Spatial histograms of soft pairwise similar patches to improve the bag-of-visual-words model

In the context of category level scene classification, the bag-of-visual-words model (BoVW) is widely used for image representation. This model is appearance based and does not contain any information regarding the arrangement of the visual words in the 2D image space. To overcome this problem, recent approaches try to capture information about either the absolute or the relative spatial location of visual words. In the first category, the so-called Spatial Pyramid Representation (SPR) is very popular thanks to its simplicity and good results. Alternatively, adding information about occurrences of relative spatial configurations of visual words was proven to be effective but at the cost of higher computational complexity, specifically when relative distance and angles are taken into account. In this paper, we introduce a novel way to incorporate both distance and angle information in the BoVW representation. The novelty is first to provide a computationally efficient representation adding relative spatial information between visual words and second to use a soft pairwise voting scheme based on the distance in the descriptor space. Experiments on challenging data sets MSRC-2, 15Scene, Caltech101, Caltech256 and Pascal VOC 2007 demonstrate that our method outperforms or is competitive with concurrent ones. We also show that it provides important complementary information to the spatial pyramid matching and can improve the overall performance.

Model‐based testing for concurrent systems with labelled event structures

SUMMARYWe propose a theoretical testing framework and a test generation algorithm for concurrent systems specified with true‐concurrency models, such as Petri nets or networks of automata. The semantic model of computation of such formalisms is labelled event structures, which allow to represent concurrency explicitly. We introduce the notions of strong and weak concurrency: strongly concurrent events must be concurrent in the implementation, while weakly concurrent ones may eventually be ordered. The ioco type conformance relations for sequential systems rely on the observation of sequences of actions and blockings; thus, they are not capable of capturing and exploiting concurrency of non‐sequential behaviours. We propose an extension of ioco for labelled event structures, named co‐ioco, allowing to deal with strong and weak concurrency. We extend the notions of test cases and test execution to labelled event structures and give a test generation algorithm building a complete test suite for co‐ioco. Copyright © 2014 John Wiley & Sons, Ltd.

How important tasks are performed: peer review

The advancement of various fields of science depends on the actions of individual scientists via the peer review process. The referees' work patterns and stochastic nature of decision making both relate to the particular features of refereeing and to the universal aspects of human behavior. Here, we show that the time a referee takes to write a report on a scientific manuscript depends on the final verdict. The data is compared to a model, where the review takes place in an ongoing competition of completing an important composite task with a large number of concurrent ones - a Deadline -effect. In peer review human decision making and task completion combine both long-range predictability and stochastic variation due to a large degree of ever-changing external “friction”.

Leveraging parallel nesting in transactional memory

Exploiting the emerging reality of affordable multi-core architectures goes through providing programmers with simple abstractions that would enable them to easily turn their sequential programs into concurrent ones that expose as much parallelism as possible. While transactional memory promises to make concurrent programming easy to a wide programmer community, current implementations either disallow nested transactions to run in parallel or do not scale to arbitrary parallel nesting depths. This is an important obstacle to the central goal of transactional memory, as programmers can only start parallel threads in restricted parts of their code. This paper addresses the intrinsic difficulty behind the support for parallel nesting in transactional memory, and proposes a novel solution that, to the best of our knowledge, is the first practical solution to meet the lowest theoretical upper bound known for the problem. Using a synthetic workload configured to test parallel transactions on a multi-core machine, a practical implementation of our algorithm yields substantial speed-ups (up to 22x with 33 threads) relatively to serial nesting, and shows that the time to start and commit transactions, as well as to detect conflicts, is independent of nesting depth.

Data Modeling for Better Performance in a Bulletin Board Application

Introduction Amongst the factors which have the greatest impact in the efficacy of computerized informing processes, are the time intervals involved in order to achieve effective communication with the information's clients. Should there be a significant delay, due either to the sending or the receiving processes, where we apply the adjective whenever the time intervals considerably exceed what the person expects or even is willing to accept, the probability of the message achieving its purpose - informing--would be considerably reduced. Additionally, user reading sessions should be considered as part of a set of possibly concurrent ones, which implies sharing computer resources with many other such processes. This in turn imposes a further constraint on the informing process: it must be efficient enough so as not to consume too many computer resources, starting with CPU usage, probably adding the use of memory, but naturally taking into account the transmission of data between resources. Thus, when defining or implementing new communication means, for example ways in which information can be posted on a computer for others to read, as in the situation described here, efficient use of computer resources should be assigned a high priority in the technical design of the processes. With the enormously powerful computers now available, taking into account their huge RAM capacities and CPU speeds, not to speak of disk space which is very inexpensive, apparently a notion prevails in the sense that it is no longer necessary to worry about processing times. This is an example of statements found: But does performance really matter? The answer is NO (Berger, 2004). Actually, notwithstanding such opinions, a very important part of the research in this field is directed towards providing more efficient ways to store and process data. Of course software products such as the package we are designing for the electronic notice board have always paid attention to their performance, but additional concern by the users of the development tools is necessary. In this paper we show one such effort. A real situation prompted the search for more efficient ways to store data, that is, to find a better data model, since the initial model did not deliver tolerable response times for the main query. First some comments on alternatives to the relational databases (RDB) are presented, since they might serve readers interested in this topic. The notice board is described in some detail in an Appendix, but its features which gave rise to the particular query are presented in the paper. The initial model formulated to store the messages, and the queries that will produce the list of messages to be offered to a user, are described next. Since there performance was unsatisfactory, a strategy of formulating alternatives, and obtaining the resulting response times via simulated data, was adopted. The subsequent models and the processing necessary to furnish the list of messages are explained, and comparisons of simulated response times for similar queries are shown. The paper concludes with some thoughts and opinions about designing data models for information systems. Relational and Other Types of Databases For the last 30 years, the use of relational databases (RDB) has dominated the technologies to store and use data in information systems and other applications, to the point that in most cases, not even a thought is given to an alternative. RDB's have gained this prestige and acceptance through a process of constant improvements, both in their technical aspects as in their relative ease of use. However, in the last few years, many applications have shown that there is no one-size-fits-all solution. Actually, both the use of other databases and relational database bashing has become fashionable. Many experts agree on something which might be termed obvious: were it not for the enormous popularity of RDB's, the appropriate model would depend on the particular situation. …

Facteurs pronostiques et prédictifs des cancers des voies aérodigestives supérieures

The head-and-neck squamous-cell carcinomas (HNSCC) represent in order of frequency the fourth leading cause of cancer deaths among men in France. The term HNSCC includes various anatomopathological and clinical entities with different evolution patterns. For this reason, it is necessary to identify prognostic and predictive factors able to help in the choice of the treatment. The clinical factors with a prognostic value are the tumor location, the tumor size and the lymph node status. The degree of differentiation is the most important histologic factor. More recently, the identification of molecular factors has opened the way to new therapies. Thus, the overexpression of EGFR is associated with a poor prognosis. Its inhibition improves the survival of patients. p53 mutations and cyclin D1 amplification are actually subject to intensive research. The tumors associated with HPV infection are distinguishable by a better prognosis. 18-alpha-FDG positron emission tomography emerges as a useful tool for the therapeutic evaluation. The evolution of surgical techniques, the development of induction chemotherapy regimen or concurrent ones with radiotherapy and new techniques of conformal irradiation also results in a better locoregional control.

Transforming sequential processes of net systems into concurrent ones

Translating sequential programs into concurrent ones to increase the time performance by making excessive use of the available recourses (processors) in the system is an important part of the compiler of concurrent programming languages. We present t

A strategy for parallel implementation of finite difference numerical schemes associated to evolution differential equations

AbstractWithin the framework of parallel numerical treatment, there are many more results on stationary (or time‐frozen) PDE's than on their evolution (or time‐dependent) counterparts. This is justified as computer simulation of time flow – an intrinsically sequential phenomenum – leads naturally to a sequential algorithm, thus inhibiting any search for concurrent ones. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

A general framework for certifying garbage collectors and their mutators

Garbage-collected languages such as Java and C# are becoming more and more widely used in both high-end software and real-time embedded applications. The correctness of the GC implementation is essential to the reliability and security of a large portion of the world's mission-critical software. Unfortunately, garbage collectors--especially incremental and concurrent ones--are extremely hard to implement correctly. In this paper, we present a new uniform approach to verifying the safety of both a mutator and its garbage collector in Hoare-style logic. We define a formal garbage collector interface general enough to reason about a variety of algorithms while allowing the mutator to ignore implementation-specific details of the collector. Our approach supports collectors that require read and write barriers. We have used our approach to mechanically verify assembly implementations of mark-sweep, copying and incremental copying GCs in Coq, as well as sample mutator programs that can be linked with any of the GCs to produce a fully-verified garbage-collected program. Our work provides a foundation for reasoning about complex mutator-collector interaction and makes an important advance toward building fully certified production-quality GCs.