CELLO: Compiler-Assisted Efficient Load-Load Ordering in Data-Race-Free Regions

Efficient Total Store Order (TSO) implementations allow loads to execute speculatively out-of-order. To detect order violations, the load queue (LQ) holds all the in-flight loads and is searched on every invalidation and cache eviction. Moreover, in a simultaneous multithreading processor (SMT), stores also search the LQ when writing to cache. LQ searches entail considerable energy consumption. Furthermore, the processor stalls upon encountering the LQ full or when its ports are busy. Hence, the LQ is a critical structure in terms of both energy and performance. In this work, we observe that the use of the LQ could be dramatically optimized under the guarantees of the datarace-free (DRF) property imposed by modern programming languages. To leverage this observation, we propose CELLO, a software-hardware co-design in which the compiler detects memory operations in DRF regions and the hardware optimizes their execution by safely skipping LQ searches without violating the TSO consistency model. Furthermore, CELLO allows removing DRF loads from the LQ earlier, as they do not need to be searched to detect consistency violations. With minimal hardware overhead, we show that an 8-core 2- way SMT processor with CELLO avoids almost all conservative searches to the LQ and significantly reduces its occupancy. CELLO allows i) to reduce the LQ energy expenditure by 33% on average (up to 53%) while performing 2.8% better on average (up to 18.6%) than the baseline system, and ii) to shrink the LQ size from 192 to only 80 entries, reducing the LQ energy expenditure as much as 69% while performing on par with a mainstream LQ implementation

Two-State Migration of DNA in a structured Microchannel

DNA migration in topologically structured microchannels with periodic cavities is investigated experimentally and with Brownian dynamics simulations of a simple bead-spring model. The results are in very good agreement with one another. In particular, the experimentally observed migration order of Lambda- and T2-DNA molecules is reproduced by the simulations. The simulation data indicate that the mobility may depend on the chain length in a nonmonotonic way at high electric fields. This is found to be the signature of a nonequilibrium phase transition between two different migration states, a slow one and a fast one, which can also be observed experimentally under appropriate conditions.Comment: Revised edition corresponding to the comments by the referees, submitted to Physical Review

Condiciones habitacionales y urbanísticas de la población inmigrada en la Región Metropolitana de Barcelona

En la última década tanto las ciudades catalanas como las del resto del Estado Español, han sufrido importantes modificaciones en su morfología física y social debido a la llegada de numerosa población inmigrante. Esta población se localiza en unas zonas determinadas de nuestras ciudades y tiene unos patrones de asentamiento residencial diferentes a los de la población nativa. Asimismo, las características de sus viviendas y el uso que hacen del espacio público son diferentes a los del resto de la población. En esta ponencia se profundizará en el uso que hace la población inmigrante del espacio público en la Región Metropolitana de Barcelona, qué espacios públicos y qué equipamientos utilizan y si estos se ajustan a sus necesidades cotidianas; qué variables tienen mayor incidencia en este uso (edad, género, procedencia); como interactúa esta población con el resto de población del barrio; qué tipo de usos hacen del espacio público; cómo se relacionan la configuración física y social del espacio….Asimismo, se intentará detallar más escuetamente cuáles son las características habitacionales de esta población: cómo son sus casas y cómo acceden a ella. El ámbito territorial de la investigación es la Región Metropolitana de Barcelona. La investigación se desarrolla en distintos barrios de la RMB con diferentes características urbanísticas y demográficas, pero que tienen en común que cuentan con una concentración de población inmigrante superior a la media de la RMB. La metodología empleada es una combinación de técnicas cuantitativas y cualitativas.In the last decade both the Catalan cities as the rest of Spain, has undergone major changes in their physical and social morphology due to the arrival of large immigrant populations. This population is located in specific areas of our cities and has a residential settlement patterns different from the native population. Furthermore, the characteristics of their homes and their use of public space are different from the rest of the population. This paper will delve into the use by the immigrant population of public space in the metropolitan area of Barcelona, what public spaces and what equipment they use and if they fit their daily needs, what variables have the greatest impact in this application (age, gender, origin), as this population interacts with the rest of the neighborhood population, and what kinds of uses made of public space, and how are the physical and social space .... It will try to detail more succinctly what characteristics housing for this population: how are their homes and how to access it. The territorial scope of the research is the metropolitan area of Barcelona. The research is conducted in different districts of the RMB with different urban and demographic characteristics, but they have in common that have a concentration of immigrant population than the average of the RMB. The methodology is a combination of quantitative and qualitative.Peer Reviewe

The arginine-vasotocin and serotonergic systems affect interspecific social behaviour of client fish in marine cleaning mutualism

Many species engage in mutualistic relationships with other species. The physiological mechanisms that affect the course of such social interactions are little understood. In the cleaning mutualism, cleaner fish Labroides dimidiatus do not always act cooperatively by eating ectoparasites, but sometimes cheat by taking bites of mucus from so-called "client" reef fish. The physiological mechanisms in these interspecific interactions, however, are little studied. Here, we focussed on three neuromodulator systems known to play important roles in intraspecific social behaviour of vertebrates to examine their role in clients' interspecific behaviour. We subjected the client fish Scolopsis bilineatus to ectoparasites and the exogenous manipulation of the vasotocin (AVT), isotocin (IT) and serotonin systems to test how this affects client willingness to seek cleaning and client aggression towards cleaners. We found that a single dose of AVT agonist and a selective antagonist caused clients to seek proximity to cleaners, independently of ectoparasite infection. In contrast, in a direct encounter task, the selective blocker of serotonin 5HTreceptors, Ketanserin (KET), made client reef fish more aggressive towards cleaners in the absence of cleaners' bites of mucus. IT did not yield any significant effects. Our results suggest that the AVT system plays a role in social affiliation towards an interspecific partner, while the serotonin system affects clients' acceptance of level of proximity to cleaner fish during interactions. These two systems, therefore, were apparently co-opted from intraspecific social interactions to affect the course of interspecific ones also

Report on the 2013 Rapid Assessment Survey of Marine Species at New England Bays and Harbors

Introduced species (i.e., non-native species that have become established in a new location) have increasingly been recognized as a concern as they have become more prevalent in marine and terrestrial environments (Mooney and Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter population, community, and ecosystem structure and function, as well as cause significant economic damage is well documented (Carlton 1989, 1996b, 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al. 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher 2000). The annual economic costs incurred from managing the approximately 50,000 introduced species in the United States alone are estimated to be over $120 billion (Pimentel et al. 2005). Having a monitoring network in place to track new introductions and distributional changes of introduced species is critical for effective management, as these efforts may be more successful when species are detected before they have the chance to become established. A rapid assessment survey is one such method for early detection of introduced species. With rapid assessment surveys, a team of taxonomic experts record and monitor marine species–providing a baseline inventory of native, introduced, and cryptogenic (i.e., unknown origin) species (as defined by Carlton 1996a)–and document range expansions of previously identified species. Since 2000, five rapid assessment surveys have been conducted in New England. These surveys focus on recording species at marinas, which often are in close proximity to transportation vectors (i.e., recreational boats). Species are collected from floating docks and piers because these structures are accessible regardless of the tidal cycle. Another reason for sampling floating docks and other floating structures is that marine introduced species are often found to be more prevalent on artificial surfaces than natural surfaces (Glasby and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys are to: (1) identify native, introduced, and cryptogenic marine species, (2) expand on data collected in past surveys, (3) assess the introduction status and range extensions of documented introduced species, and (4) detect new introductions. This report presents the introduced, cryptogenic, and native species recorded during the 2013 survey

Physical weathering of carbonate host-rock by precipitation of soluble salts in caves: A case study in El Orón-Arco Cave (Region of Murcia, SE Spain)

The dissolution of carbonate host-rock by freshwater in phreatic or vadose conditions is the most common mechanism for the formation of caves; however, circulation of saline solutions through carbonate materials and precipitation of soluble salts may also play an important role. We studied the stable isotope composition (δ18O and δ34S of sulfate, δ18O and δD of structurally-bound gypsum hydration water and 87Sr/86Sr) and salinity of fluid inclusions in gypsum speleothems found in El Orón-Arco Cave (Cartagena, SE Spain). We suggest that physical weathering of carbonate host-rock was driven by precipitation of soluble sea-salts (mostly gypsum and halite), and this process controlled the recent geomorphological evolution of the cave. The Triassic carbonate host-rock shows clear evidence for salt weathering, including gypsum/halite infillings in cracks of the bedrock, mechanical spalling of the carbonate, and detachment of rock fragments that lead to the formation cave voids and in-situ accumulations of piles of unsorted rubble. Sulfur and oxygen isotopes of gypsum sulfate (3.0‰ < δ18O < 11.6‰ and 16.7‰ < δ34S < 20.7‰) are generally lower than modern seawater sulfate and suggest contributions from a 34S-depleted source (i.e. oxidation of pyrite). The δ18O and δD of gypsum hydration water are relatively low compared to expected values for the evaporation of pure seawater to gypsum saturation, suggesting that gypsum precipitation involved a secondary calcium-sulfate source or recycling of gypsum from previous stages, along with mixing of seawater and meteoric water seepage to the cave. The 87Sr/86Sr in gypsum shows intermediate values between modern seawater and Triassic carbonate values because of interaction between the solution and the bedrock. The salinities of the speleothem-forming solutions are relatively high (13.2 ± 3.2 wt% eq. NaCl) compared to gypsum formed from evaporated brackish solutions (i.e. ~4–8 wt% eq. NaCl) and indicate dissolution of earlier evaporites before secondary gypsum precipitation. This cave-forming mechanism, which is related to saline water circulation and precipitation of evaporitic minerals, may be common in other coastal caves

Condiciones habitacionales y urbanísticas de la población inmigrada en la Región Metropolitana de Barcelona

En la última década tanto las ciudades catalanas como las del resto del Estado Español, han sufrido importantes modificaciones en su morfología física y social debido a la llegada de numerosa población inmigrante. Esta población se localiza en unas zonas determinadas de nuestras ciudades y tiene unos patrones de asentamiento residencial diferentes a los de la población nativa. Asimismo, las características de sus viviendas y el uso que hacen del espacio público son diferentes a los del resto de la población. En esta ponencia se profundizará en el uso que hace la población inmigrante del espacio público en la Región Metropolitana de Barcelona, qué espacios públicos y qué equipamientos utilizan y si estos se ajustan a sus necesidades cotidianas; qué variables tienen mayor incidencia en este uso (edad, género, procedencia); como interactúa esta población con el resto de población del barrio; qué tipo de usos hacen del espacio público; cómo se relacionan la configuración física y social del espacio….Asimismo, se intentará detallar más escuetamente cuáles son las características habitacionales de esta población: cómo son sus casas y cómo acceden a ella. El ámbito territorial de la investigación es la Región Metropolitana de Barcelona. La investigación se desarrolla en distintos barrios de la RMB con diferentes características urbanísticas y demográficas, pero que tienen en común que cuentan con una concentración de población inmigrante superior a la media de la RMB. La metodología empleada es una combinación de técnicas cuantitativas y cualitativas.In the last decade both the Catalan cities as the rest of Spain, has undergone major changes in their physical and social morphology due to the arrival of large immigrant populations. This population is located in specific areas of our cities and has a residential settlement patterns different from the native population. Furthermore, the characteristics of their homes and their use of public space are different from the rest of the population. This paper will delve into the use by the immigrant population of public space in the metropolitan area of Barcelona, what public spaces and what equipment they use and if they fit their daily needs, what variables have the greatest impact in this application (age, gender, origin), as this population interacts with the rest of the neighborhood population, and what kinds of uses made of public space, and how are the physical and social space .... It will try to detail more succinctly what characteristics housing for this population: how are their homes and how to access it. The territorial scope of the research is the metropolitan area of Barcelona. The research is conducted in different districts of the RMB with different urban and demographic characteristics, but they have in common that have a concentration of immigrant population than the average of the RMB. The methodology is a combination of quantitative and qualitative.Peer Reviewe

Viés de manutenção da atenção na ansiedade social

The role of attentional bias in social anxiety is not yet fully understood. Social anxiety individuals can show deliberate avoidance of socially threatening stimuli or, on the contrary, be hypervigilant, persistently allocating attention to those stimuli. Our main purpose was to test whether social anxiety is preferably associated with mechanisms of hypervigilance, avoidance, vigilance-avoidance or maintenance of attention towards socially relevant stimuli. Our secondary goal was to explore the modulating role of personality traits in these attention bias mechanisms. Participants with high vs low social anxiety and different personality structures were exposed to pairs of faces representing different emotions (anger, happiness and neutrality) while their eye movements were continuously recorded. Comparisons between participants with high and low levels of social anxiety showed that participants with high social anxiety were slower in disengaging their attention from happy faces, suggesting that positive emotions can be perceived as a threatening stimuli for social anxious individuals. Preliminary results indicated that depressive personality structure may favour manifestations of hypervigilance bias toward threat faces.info:eu-repo/semantics/publishedVersio

Report on the 2013: Rapid assessment survey of marine species at New England Bays and Harbors

Introduced species (i.e., non-native species that have become established in\ud a new location) have increasingly been recognized as a concern as they have\ud become more prevalent in marine and terrestrial environments (Mooney and\ud Cleland 2001; Simberloff et al. 2005). The ability of introduced species to alter\ud population, community, and ecosystem structure and function, as well as\ud cause significant economic damage is well documented (Carlton 1989, 1996b,\ud 2000; Cohen and Carlton 1995; Cohen et al. 1995; Elton 1958; Meinesz et al.\ud 1993; Occhipinti-Ambrogi and Sheppard 2007; Pimentel et al. 2005; Thresher\ud 2000). The annual economic costs incurred from managing the approximately\ud 50,000 introduced species in the United States alone are estimated to be over\ud $120 billion (Pimentel et al. 2005).\ud Having a monitoring network in place to track new introductions and\ud distributional changes of introduced species is critical for effective\ud management, as these efforts may be more successful when species are\ud detected before they have the chance to become established. A rapid\ud assessment survey is one such method for early detection of introduced\ud species. With rapid assessment surveys, a team of taxonomic experts\ud record and monitor marine species–providing a baseline inventory of\ud native, introduced, and cryptogenic (i.e., unknown origin) species (as\ud defined by Carlton 1996a)–and document range expansions of previously\ud identified species.\ud Since 2000, five rapid assessment surveys have been conducted in New\ud England. These surveys focus on recording species at marinas, which often\ud are in close proximity to transportation vectors (i.e., recreational boats).\ud Species are collected from floating docks and piers because these structures\ud are accessible regardless of the tidal cycle. Another reason for sampling floating\ud docks and other floating structures is that marine introduced species are often\ud found to be more prevalent on artificial surfaces than natural surfaces (Glasby\ud and Connell 2001; Paulay et al. 2002). The primary objectives of these surveys\ud are to: (1) identify native, introduced, and cryptogenic marine species,\ud (2) expand on data collected in past surveys, (3) assess the introduction status\ud and range extensions of documented introduced species, and (4) detect new\ud introductions. This report presents the introduced, cryptogenic, and native\ud species recorded during the 2013 survey.CZM through NOAA NA13NOS4190040MIT Sea Grant through NOAA NA10OAR4170086