Study of an iterative resource allocation technique to minimize machine completion times in a distributed computing system

Heterogeneous computing (HC) is the coordinated use of different types of machines, networks, and interfaces to maximize the combined performance and/or cost effectiveness. Heuristics for allocating resources in an HC system have different optimization criteria. A common optimization criterion is to minimize the completion time of the last to finish machine (makespan). In some environments, it is useful to minimize the finishing times of the other machines in the system, i.e., those machines that are not the last to finish. Consider a production environment where a set of known tasks are to be mapped to resources off-line before execution begins. In this study, we present an "iterative" approach for decreasing the finishing time of each machine in a given resource allocation, by repeatedly running a mapping heuristic to minimize makespan on all machines and then the non-makespan machines; i.e., ignoring the current makespan machine and the tasks assigned to it. This work identifies heuristics that can offer improvements in the completion time of non-makespan machines using this "iterative" approach

First fossil record (Middle Miocene) of the viper shark Trigonognathus Mochizuki and Ohe, 1990, in the Mediterranean realm

The genus Trigonognathus Mochizuki and Ohe, 1990, is a monospecific taxon of `lantern sharks¿ (i.e., family Etmopteridae), a group of small-sized bioluminescent deep-sea chondrichthyans, ranging in mature male specimens between 42¿47 cm total length, and at least 52 cm for females (Ebert et al., 2021). This shark inhabits the upper continental slopes as well as the uppermost slope of seamounts, often at the bottom, at depths ranging between 250¿1000 m, but has been caught at 150 m and 270 m in deep open waters (Mochizuki and Ohe, 1990; Compagno et al., 2005; Ebert et al., 2021). Only two species have been described thus far, the extant species Trigonognathus kabeyai Mochizuki and Ohe, 1990, and the extinct ¿Trigonognathus virginiae from the middle Eocene of France (Cappetta and Adnet, 2001). Trigonognathus kabeyai exhibits a combination of morphological characteristics that are unique among Squaliformes, like a highly protrudable jaw articulation (Shirai and Okamura, 1992; Straube et al., 2010), and a lack of dignathic heterodonty. Additionally, the tearing-type dentition, and strong monognathic heterodonty with hypertrophied anterior teeth, differentiate it from the genus Squalus and Cirrigaleus (with cutting-type dentition), and Centroscyllium and Aculeola (with no monognathic heterodonty and clutching-type dentition) (Cappetta and Adnet, 2001). The geographic distribution of T. kabeyai is restricted to the Pacific Ocean, in the Wakayama and Tokushima coasts of Japan (Mochizuki and Ohe, 1990; Shirai and Okamura, 1992; Ebert et al., 2021), Taiwan (Ebert et al., 2013), and in the north-west of Hawaii (Wetherbee and Kajiura, 2000). However, the fossil record of the genus Trigonognathus indicates a broader geographic distribution in the past (Aguilera and Rodriguez de Aguilera, 2001; Cappetta and Adnet, 2001; Carrillo-Briceño et al., 2015). These findings include ¿T. virginiae from the middle Eocene of Landes (eastern Atlantic), southwestern France (Cappetta and Adnet, 2001), and two isolated teeth assigned to Trigonognathus sp. and Trigonognathus aff. kabeyai from the Upper Miocene of Panama (Carrillo-Briceño et al., 2015) and the Upper Miocene¿Lower Pliocene of Venezuela (Caribbean Sea) (Aguilera and Rodriguez de Aguilera, 2001), respectively. Given the apparent rarity of this elusive taxon, any new finding, especially in the fossil record, is of note and increases our knowledge of this genus. Herein we describe a Middle Miocene locality with the first known record of Trigonognathus in the Mediterranean realm (south-eastern Spain), which offers new insight into the paleoenvironmental and paleobiogeographic history of this shark. In addition, with the objective of providing new information about possible diagnostic characteristics of the genus, the first description of its internal tooth histology is provided

Life Histories of the Seed Bugs, Kleidocerys punctatus and Kleidocerys virescens

The life cycles of the seed bugs, Kleidocerys punctatus Distant and Kleidocerys virescens F. (Hemiptera: Lygaeidae: Ischnorhynchinae), are reported for the first time. Description of all immature stages and adults are included. Adults and nymphs of K. punctatus are associated with several species of Alnus (Betulaceae), while those of K. virescens are associated with Nicotiana glauca Graham, Nicotiana tabacum L. (Solanaceae), and Buddleia crotonoides A. Gray and Buddleia sp. (Loganiaceae). Adults and nymphs feed mainly on the seeds, inside the dry fruit, but they also take plant juices from other reproductive and vegetative structures. Illustrations of the eggs, all nymphal instars, and the adults, as well as notes on their biology and their distribution in Mexico, are included

Measuring the robustness of resource allocations for distributed domputer systems in a stochastic dynamic environment

Heterogeneous distributed computing systems often must function in an environment where system parameters are subject to variations during operation. Robustness can be defined as the degree to which a system can function correctly in the presence of parameter values different from those assumed. We present a methodology for quantifying the robustness of resource allocations in a dynamic environment where task execution times vary within predictable ranges and tasks arrive randomly. The methodology is evaluated through measuring the robustness of three different resource allocation heuristics within the context of the stochastically modeled dynamic environment. A Bayesian regression model is fit to the combined results of the three heuristics to demonstrate the correlation between the stochastic robustness metric and the presented performance metric. The correlation results demonstrated the significant potential of the stochastic robustness metric to predict the relative performance of the three heuristics given a common objective function

Tiburones de aguas profundas en el Mioceno Medio de Alicante: implicaciones para la recuperación de los ecosistemas abisales mediterráneos después de la crisis mesiniense

El estudio de la localidad clásica de El Chorrillo del Mioceno Medio (Serravaliense) en la Provincia de Alicante, ha permitido la recuperación de una interesante asociación de microrestos de tiburones caracterizada por al menos siete taxones (Deania calcea, †Isistius triangulus, †Squaliolus cf. schaubi, †Paraetmopterus sp., Pristiophorus sp., Scyliorhinus sp. y un Squaliforme indeterminado) pertenecientes a tres órdenes diferentes (Squaliformes, Pristiophoriformes y Carcharhiniformes). Asociados a estos microrestos se han identificado también macrodientes pertenecientes a Cosmopolitodus hastalis, Isurus sp., Hemipristis serra, Odontaspis sp., Carcharhinus spp. y †Otodus (Megaselachus) megalodon. El conjunto contiene especies con preferencias ambientales dispares, que incluyen no sólo tiburones neríticos y epipelágicos (aguas someras o abiertas), sino también un número importante de representantes meso y batipelágicos (tiburones de profundidad). Esta asociación “mezclada” es interpretada no como consecuencia de factores tafonómicos, sino por aspectos biológicos intrínsecos a la fauna que los componen. En este sentido, la migración de taxones de aguas profundas a aguas más superficiales a través de cañones submarinos para alimentarse (como sucede en la actualidad), pudo ser la causa más plausible para explicar el origen de tal asociación. Por otro lado, es importante destacar que la composición de los taxones de aguas profundas aquí descritas contrasta con el conjunto de condríctios del Plioceno, Pleistoceno y del de las comunidades mediterráneas actuales. Estos datos indican que la crisis de salinidad del Mesiniense afectó de forma importante a la evolución posterior de los ecosistemas abisales mediterráneos, pero que las diferencias detectadas con los faunas actuales debieron deberse además a otros factores, como la existencia de eventos anóxicos en los fondos abisales durante el Cuaternario.The study of the classical locality of El Chorrillo, (Serravallian, Middle Miocene) from the Alicante Province has yielded a shark assemblage characterized by microremains of at least seven taxa (Deania calcea, †Isistius triangulus, †Squaliolus cf. S. schaubi, †Paraetmopterus sp., Pristiophorus sp., Scyliorhinus sp. and a cf. Squaliformes indet) of three different orders (Squaliformes, Pristiophoriformes and Carcharhinuformes). In addition, associated macroremains have also been found, including teeth of †Cosmopolitodus hastalis, Isurus sp., Hemipristis serra, Odontaspis sp., Carcharhinus spp. and †Otodus (Megaselachus) megalodon. The assemblage contains taxa with disparate environmental preferences including not only neritic and epipelagic sharks but also an important number of meso- and bathypelagic representatives. The migration of deep water taxa to shallower waters through submarine canyons is proposed as the most plausible cause for explaining the origin of such assemblage. Interestingly, the composition of the deep-water taxa here reported contrast with the chondrichthyans assemblages from the Pliocene and extant Mediterranean communities. This entails a complex biogeographic history, where the Messinian salinity crisis strongly affected the posterior evolution of the Mediterranean ecosystems but some other factors, such us the existence of anoxic events during the Quaternary, could have also played an important role

Researching the use of force: The background to the international project

This article provides the background to an international project on use of force by the police that was carried out in eight countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has looked at police officers’ own views on the use of force, in particular the way in which they justify it. Using a hypothetical encounter developed for this project, researchers in each country conducted focus groups with police officers in which they were encouraged to talk about the use of force. The results show interesting similarities and differences across countries and demonstrate the value of using this kind of research focus and methodology

Towards key-frame extraction methods for 3D video: a review

The increasing rate of creation and use of 3D video content leads to a pressing need for methods capable of lowering the cost of 3D video searching, browsing and indexing operations, with improved content selection performance. Video summarisation methods specifically tailored for 3D video content fulfil these requirements. This paper presents a review of the state-of-the-art of a crucial component of 3D video summarisation algorithms: the key-frame extraction methods. The methods reviewed cover 3D video key-frame extraction as well as shot boundary detection methods specific for use in 3D video. The performance metrics used to evaluate the key-frame extraction methods and the summaries derived from those key-frames are presented and discussed. The applications of these methods are also presented and discussed, followed by an exposition about current research challenges on 3D video summarisation methods

Eco-epidemiological analysis of rickettsial seropositivity in rural areas of Colombia: A multilevel approach

ABSTARCT: Rickettsiosis is a re-emergent infectious disease without epidemiological surveillance in Colombia. This disease is generally undiagnosed and several deadly outbreaks have been reported in the country in the last decade. The aim of this study is to analyze the eco-epidemiological aspects of rickettsial seropositivity in rural areas of Colombia where outbreaks of the disease were previously reported. A cross-sectional study, which included 597 people living in 246 households from nine hamlets in two municipalities of Colombia, was conducted from November 2015 to January 2016. The survey was conducted to collect sociodemographic and household characteristics (exposure) data. Blood samples were collected to determine the rickettsial seropositivity in humans, horses and dogs (IFA, cut-off = 1/128). In addition, infections by rickettsiae were detected in ticks from humans and animals by real-time PCR targeting gltA and ompA genes. Data was analyzed by weighted multilevel clog-log regression model using three levels (person, household and hamlets) and rickettsial seropositivity in humans was the main outcome. Overall prevalence of rickettsial seropositivity in humans was 25.62% (95%CI 22.11-29.12). Age in years (PR = 1.01 95%CI 1.01-1.02) and male sex (PR = 1.65 95%CI 1.43-1.90) were risk markers for rickettsial seropositivity. Working outdoors (PR = 1.20 95%CI 1.02-1.41), deforestation and forest fragmentation for agriculture use (PR = 1.75 95%CI 1.51-2.02), opossum in peridomiciliary area (PR = 1.56 95%CI 1.37-1.79) and a high proportion of seropositive domestic animals in the home (PR20-40% vs 40% vs <20% = 3.14 95%CI 2.43-4.04) were associated with rickettsial seropositivity in humans. This study showed the presence of Rickettsia antibodies in human populations and domestic animals. In addition, different species of rickettsiae were detected in ticks collected from humans and animals. Our results highlighted the role of domestic animals as sentinels of rickettsial infection to identify areas at risk of transmission, and the importance of preventive measures aimed at curtailing deforestation and the fragmentation of forests as a way of reducing the risk of transmission of emergent and re-emergent pathogens

El Estado como garante de la educación superior para la formación de profesionales con herramientas para la construcción de la sociedad civil

Para lograr un país desarrollado tanto en el ámbito social, económico y político, se requiere contar con una sociedad formada en competencias que promuevan la capacidad de tomar decisiones democráticas, la participación activa y la responsabilidad social. Una sociedad capaz de analizar y contribuir en procesos colectivos. En general, una sociedad consciente de la realidad en la que se encuentra para buscar la transformación de sus entidades. Por consiguiente, es preciso que el Estado, se preocupe por garantizar que las instituciones de educación superior, sean actores principales en la formación y en la capacitación de los próximos profesionales. La educación superior, como derecho fundamental, servicio público y ciclo de formación de las personas, debe estar en capacidad de formar generaciones que asuman responsabilidades, y de manera competente tomen para sí mismos los compromisos y retos para la transformación y el desarrollo político, económico y social del país. Este trabajo pretende identificar cuál es el nivel de control del Estado y su responsabilidad frente a la educación impartida en las instituciones de educación superior como formadoras de profesionales íntegros, con competencias necesarias para la transformación del país.To have a developed country in both social, economic and political spheres, it is necessary to have a society mature and educated in competences that promote the ability in democratic decisions making, active participation and social responsibility. A society able to analyze and contribute in collective processes and aware of the reality it faces to seek social transformations. Ergo, it is necessary for the State to guarantee that the educational institutions become the main actors in the education and training of future professionals. The higher education as fundamental right, public service, and human development process, should be able to prepare generations that can accept responsibilities, and play a role in the commitments and challenges for the political development, economic growth, and social progress in this country. This thesis aims to identify the control level of the government and its responsibility, regarding both the education provided in institutions of higher education as trainers of complete professionals, and the competences requested for the transformation of the country.Magíster en DerechoMaestrí