Speculative dynamic vectorization

Traditional vector architectures have shown to be very effective for regular codes where the compiler can detect data-level parallelism. However, this SIMD parallelism is also present in irregular or pointer-rich codes, for which the compiler is quite limited to discover it. In this paper we propose a microarchitecture extension in order to exploit SIMD parallelism in a speculative way. The idea is to predict when certain operations are likely to be vectorizable, based on some previous history information. In this case, these scalar instructions are executed in a vector mode. These vector instructions operate on several elements (vector operands) that are anticipated to be their input operands and produce a number of outputs that are stored on a vector register in order to be used by further instructions. Verification of the correctness of the applied vectorization eventually changes the status of a given vector element from speculative to non-speculative, or alternatively, generates a recovery action in case of misspeculation. The proposed microarchitecture extension applied to a 4-way issue superscalar processor with one wide bus is 19% faster than the,same processor with 4 scalar buses to Ll data cache. This speed up is due basically to 1) the reduction in number of memory accesses, 15% for SpecInt and 20% for SpecFP, 2) the transformation of scalar arithmetic instructions into their vector counterpart, 28% for SpecInt and 23% for SpecFP, and 3) the exploitation of control independence for mispredicted branches.Peer ReviewedPostprint (published version

Evaluación de la distribución actual y riesgo de expansión del caracol del cieno de Nueva Zelanda, Potamopyrgus antipodarum, en la Península Ibérica y en la Cuenca Hidrográfica del Ebro.

Las invasiones biológicas constituyen uno de los principales componentes del cambio global, causando graves impactos ecológicos y socioeconómicos. Para poder afrontar este reto con eficiencia, se necesitan herramientas con las que asignar recursos para la prevención y gestión de especies invasoras de manera eficiente. Los Modelos de Distribución de Especies (SDM), son utilizados frecuentemente para localizar las zonas más vulnerables a la invasión y donde los costes de gestión serían invertidos con mayor eficiencia. En el presente trabajo, se han utilizado SDM para investigar la expansión potencial del caracol del cieno de Nueva Zelanda (Potamopyrgus antipodarum), una especie invasora de agua dulce que se ha expandido por varios continentes y está presente en la Península Ibérica desde principios el siglo XX. En primer lugar se ha confeccionado un mapa de distribución en la Península Ibérica a partir de referencias bibliográficas, y posteriormente se han generado dos SDM con los que calcular la idoneidad del hábitat para la especie a dos escalas espaciales diferentes: Península Ibérica y cuenca del Ebro. Las conclusiones del estudio a escala peninsular han sido que existen poblaciones de P. antipodarum dispersas por toda la superficie de la Península Ibérica, particularmente concentradas en la mitad Noreste (costa mediterránea, proximidades de Madrid…). Las zonas más susceptibles a la invasión a corto plazo se sitúan en zonas de baja altitud, debido a las condiciones de temperatura templadas y la frecuencia de actividades socioeconómicas que favorecen la dispersión y éxito de establecimiento de la especie. A escala de la cuenca del Ebro, el riesgo de invasión es también más alto en las tierras bajas (proximidades de Zaragoza, Pamplona y a lo largo del cauce principal del Ebro…) por la abundancia de nutrientes, calcio y velocidades de corriente reducidas, junto con las temperaturas mínimas moderadas y la presión antropogénica. De hecho, el grado de alteración humana es el factor de riesgo más importante identificado a través de SDM, por su vinculación con la presión de propágulos y la menor competencia que ofrece la ya depauperada fauna autóctona

La reproducción animal en 1º de bachillerato: una propuesta didáctica

El presente trabajo describe la propuesta didáctica llevada a cabo para impartir una Unidad Didáctica sobre Reproducción animal en un aula de 1º de Bachillerato. La propuesta didáctica se desarrollo durante 9 sesiones de clase: las 5 primeras fueron clases magistrales de teoría, las 2 siguientes fueron dedicadas a sendas actividades en formato de flipped classroom, una clase dedicada al examen de teoría y una última sesión de retroalimentación (corrección del examen y de las flipped classroom, evaluación del profesor). La primera sesión de flipped classroom consistió en rellenar por grupos una ficha en las que se describían unas características (principalmente reproductivas, como tipo de fecundación, gestación y desarrollo, existencia de reproducción asexual, etc., aunque también se recogía la clasificación taxonómica, alimentación, distribución y hábitat, etc.) de un ser vivo concreto: deberían de identificar un taxón que cumpliera con estos requisitos y, con el resto de sus características, rellenar el resto de los campos. En la segunda actividad de flipped classroom, que dependía de la primera, los estudiantes debían de completar un cuestionario con las fichas rellenas en la sesión anterior. Las cuestiones describían una serie de consecuencias de las características reproductivas que presentaban los animales de las fichas. La propuesta didáctica y las diferentes actividades que incluye han sido justificadas basándose en los conocimientos existentes sobre didáctica de las ciencias

Removing checks in dynamically typed languages through efficient profiling

Dynamically typed languages increase programmer's productivity at the expense of some runtime overheads to manage the types of variables, since they are not declared at compile time and can change at runtime. One of the most important overheads is due to very frequent checks that are introduced in the specialized code to identify the type of the variables. In this paper, we present a HW/SW hybrid mechanism that allows the removal of checks executed in the optimized code by performing a HW profiling of the types of object variables. To demonstrate the benefits of the proposed technique, we implement it in a JavaScript engine and show that it produces 7.1% speedup on average for optimized JavaScript code (up to 34% for some applications) and 6.5% energy reduction.Peer ReviewedPostprint (author's final draft

Barbary Coast in the expansion of international society: piracy, privateering and corsairing as primary institutions

From the ‘long’ sixteenth century the Ottoman regencies of North Africa operated as major centres of piracy and privateering across the Mediterranean sea. Though deemed by emerging European powers to be an expression of the ‘barbarian’ status of Muslim and Ottoman rulers and peoples, piracy and corsairing in fact played a major role in the development of the ‘primary’ or ‘master’ institutions of international society such as sovereignty, war and international law. Far from representing a ‘barbarian’ challenge to the European ‘standard of civilization’, piracy and privateering in the modern Mediterranean acted as contradictory vehicles in the affirmation of that very standard. This paper explores in some historical detail the ways in which piracy and corsairing off the Barbary Coast in effect acted as ‘derivative’ primary institutions of international society, as Barry Buzan has labelled them. It argues that piracy and corsairing simultaneously contributed to the construction of north African sovereignty whilst also prompting successive wars and treaties aimed at outlawing such practices. The cumulative effect of these complex historical experiences was certainly the expansion of international society and its accompanying master institutions. Yet the manner of their consolidation – at least in the western Mediterranean - suggests that primary institutions of international society owe much more to ‘barbarism’ and ‘illegality’ than is commonly acknowledged

HW/SW Co-designed Processors: Challenges, Design Choices and a Simulation Infrastructure for Evaluation

Improving single thread performance is a key challenge in modern microprocessors especially because the traditional approach of increasing clock frequency and deep pipelining cannot be pushed further due to power constraints. Therefore, researchers have been looking at unconventional architectures to boost single thread performance without running into the power wall. HW/SW co-designed processors like Nvidia Denver, are emerging as a promising alternative. However, HW/SW co-designed processors need to address some key challenges such as startup delay, providing high performance with simple hardware, translation/optimization overhead, etc. before they can become mainstream. A fundamental requirement for evaluating different design choices and trade-offs to meet these challenges is to have a simulation infrastructure. Unfortunately, there is no such infrastructure available today. Building the aforementioned infrastructure itself poses significant challenges as it encompasses the complexities of not only an architectural framework but also of a compilation one. This paper identifies the key challenges that HW/SW codesigned processors face and the basic requirements for a simulation infrastructure targeting these architectures. Furthermore, the paper presents DARCO, a simulation infrastructure to enable research in this domain.Peer ReviewedPostprint (author's final draft

'In vitro' capacitation and acrosome reaction are concomitant with specific changes in mitochondrial activity in boar sperm: evidence for a nucleated mitochondrial activation and for the existence of a capacitation-sensitive subpopulational structure

The main scope of this manuscript is to analyse the dynamics of mitochondrial activity in boar sperm subjected to 'in vitro' capacitation (IVC) and subsequent progesterone-induced 'in vitro' acrosome reaction (IVAR). This was determined after analysis of the rhythm of O(2) consumption and concomitant changes in the mitochondria activity-specific JC-1 staining. Results showed that IVC, and especially IVAR, was concomitant with a peak in O(2) consumption (from 1.61 ± 0.08 nmol O(2)/min/10(7) viable sperm at 0 h of incubation to 2.62 ± 0.12 nmol O(2) /min/10(7) viable sperm after 5 min of IVAR induction). These results were accompanied by parallel changes in the mean intensity of JC-1 staining. Based on JC-1, mitochondrial activation followed a nucleated pattern, with specific, activation starting points at the midpiece from which mitochondrial activation was spread. Moreover, four separate sperm subpopulations were detected following the JC-1 orange-red/green ratio, and the observed changes in the mean JC-1 staining during IVC and IVAR were related to concomitant changes in both the orange-red/green JC-1 ratio and the percentage of sperm included in each subpopulation. All of these results indicate that IVC and the first minutes of IVAR are accompanied by a progressive increase in mitochondrial activity, which reached a peak coincidental with the achievement of IVAR. Moreover, results suggest the presence of separate sperm subpopulations, which show a different mitochondrial sensitivity to IVC and IVAR. Finally, mitochondrial activation, at least under JC-1 staining, seems to originate in concrete nucleation points at the midpiece, thus suggesting thus a well-coordinated pattern in boar-sperm mitochondrial activity modulation

Capitalism and the sea: Sovereignty, territory and appropriation in the global ocean

This paper introduces the term ‘terraqueous territoriality’ to analyse a particular relationship between capitalism as a social formation, and the sea as a natural force. It focuses on three spaces – exclusive economic zones (EEZs), the system of ‘flags of convenience’ (FOC), and multilateral counter-piracy initiatives – as instances of capitalist states and firms seeking to transcend the geo-physical difference between firm land and fluid sea. Capital accumulation, it is argued here, seeks to territorialise the sea through forms of sovereignty and modes of appropriation drawn from experiences on land, but in doing so encounters particular tensions thereby generating distinctive spatial effects. By exploring the articulation between sovereignty, territory and appropriation in the organisation of spaces where land meets sea, the article seeks to demonstrate the value of an analytical framework that underlines the terraqueous nature of contemporary capitalism

Social Movements and International Relations: A Relational Framework

Social movements are increasingly recognized as significant features of contemporary world politics, yet to date their treatment in international relations theory has tended to obfuscate the considerable diversity of these social formations, and the variegated interactions they may establish with state actors and different structures of world order. Highlighting the difficulties conventional liberal and critical approaches have in transcending conceptions of movements as moral entities, the article draws from two under-exploited literatures in the study of social movements in international relations, the English School and Social Systems Theory, to specify a wider range of analytical interactions between different categories of social movements and of world political structures. Moreover, by casting social movement phenomena as communications, the article opens international relations to consideration of the increasingly diverse trajectories and second-order effects produced by social movements as they interact with states, intergovernmental institutions, and transnational actors

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries