Garbage collection auto-tuning for Java MapReduce on Multi-Cores

MapReduce has been widely accepted as a simple programming pattern that can form the basis for efficient, large-scale, distributed data processing. The success of the MapReduce pattern has led to a variety of implementations for different computational scenarios. In this paper we present MRJ, a MapReduce Java framework for multi-core architectures. We evaluate its scalability on a four-core, hyperthreaded Intel Core i7 processor, using a set of standard MapReduce benchmarks. We investigate the significant impact that Java runtime garbage collection has on the performance and scalability of MRJ. We propose the use of memory management auto-tuning techniques based on machine learning. With our auto-tuning approach, we are able to achieve MRJ performance within 10% of optimal on 75% of our benchmark tests

The kinematics of the quadrupolar nebula M1-75 and the identification of its central star

The link between the shaping of bipolar planetary nebulae and their central stars is still poorly understood. The kinematics and shaping of the multipolar nebula M 1-75 are hereby investigated, and the location and nature of its central star are briefly discussed. Fabry-Perot data from GHaFAS on the WHT sampling the Doppler shift of the [N II] 658.3 nm line are used to study the dynamics of the nebula, by means of a detailed 3-D spatio-kinematical model. Multi-wavelength images and spectra from the WFC and IDS on the INT, and from ACAM on the WHT, allowed us to constrain the parameters of the central star. The two pairs of lobes, angularly separated by ~22 degrees, were ejected simultaneously approx. ~3500-5000 years ago, at the adopted distance range from 3.5 to 5.0 kpc. The larger lobes show evidence of a slight degree of point symmetry. The shaping of the nebula could be explained by wind interaction in a system consisting of a post-AGB star surrounded by a disc warped by radiative instabilities. This requires the system to be a close binary or a single star which engulfed a planet as it died. On the other hand, we present broad- and narrow-band images and a low S/N optical spectrum of the highly-reddened, previously unnoticed star which is likely the nebular progenitor. Its estimated V-I colour allows us to derive a rough estimate of the parameters and nature of the central star.Comment: 8 pages, 6 figures, accepted for publication in Astronomy & Astrophysic

Biocompatibility Studies of Local Antibiotic-eluting Devices for Orthopaedic Applications

Introduction: Efficient local antibiotic-eluting devices could be an alternative for delivery of locally therapeutic antibiotics into tissues, avoiding bacterial contamination on implanted materials and minimizing side effects. A proper assessment of biocompatibility of the biomaterials used is important to improve safety after implantation. We present cytotoxicological and implantation tests results to evaluate biocompatibility of two drug-eluting systems with potential use in orthopaedic implants. Materials and Methods: Cytotoxicological studies were carried out by evaluating the in-vitro dose-dependent effect of cefazolin and linezolid on fibroblasts, keratinocytes, macrophages and osteoblasts. Cells were incubated with antibiotic concentrations ranging from 0.25 to 1.5 mg/ml. Cellular viability was assessed by the Alamar blue test. Cell cycle and apoptosis were measured by flow cytometry. Short-term implantation tests were performed in an ovine model to assess the local effects of the device. Two implants were used: (1) a macroporous stainless steel reservoir loaded with linezolid and (2) stainless steel pins with orifices drilled in the reservoir wall loaded with cefazolin. Implants were placed in sheep tibias. Tissues were studied by pathological means, determining the local effect and tissue response from the implant. (Ethical committee approval number: PI36/14) Results: Cytotoxic effects of cefazolin and linezolid were only found at 1.5 mg/ml on keratinocytes and osteoblasts, respectively. There were no significant changes on cell cycle and apoptosis at 1.0 mg/ml. Sheep with both antibiotic-loaded implants did not show local or systemic adverse effects. Conclusions: These results showed no potential toxic effects for the designed devices. However, the antibiotic local concentration should not exceed 1.0 mg/ml

A controlled antibiotic release system to prevent orthopedic-implant associated infections: An in vitro study

A new device for local delivery of antibiotics is presented, with potential use as a drug-eluting fixation pin for orthopedic applications. The implant consists of a stainless steel hollow tubular reservoir packed with the desired antibiotic. Release takes place through several orifices previously drilled in the reservoir wall, a process that does not compromise the mechanical properties required for the implant. Depending on the antibiotic chosen and the number of orifices, the release profile can be tailored from a rapid release of the load (ca. 20 h) to a combination of rapid initial release and slower, sustained release for a longer period of time (ca. 200 h). An excellent bactericidal action is obtained, with 4-log reductions achieved in as little as 2 h, and total bacterial eradication in 8 h using 6-pinholed implants filled with cefazolin

Variedades de feijão e seus efeitos na qualidade protéica, na glicemia e nos lipídios sangüíneos em ratos.

O feijão representa importante fonte de proteína e pode auxiliar na modulação dos níveis de glicose e lipídios sangüíneos. Objetivou-se avaliar o valor protéico e funcional de variedades de feijão. Para a qualidade protéica foram usados 7 grupos (n = 6) de ratos recém desmamados: um recebeu dieta aprotéica por 14 dias e os demais, dietas contendo 9-10% de proteína como caseína ou como um dos feijões (Ouro Branco, Pérola, BRS Radiante, Diamante Negro e Talismã). No segundo experimento, 4 grupos (n = 10) de ratos adultos receberam dietas de caseína, Ouro Branco, Diamante Negro e Talismã por 28 dias. Ouro Branco apresentou maior Coeficiente de Eficiência Protéica (PERr = 61,18%) do que os demais e o BRS Radiante o menor (PERr = 44,60%). Quanto à Razão Protéica Líquida (NPR) e à digestibilidade, não houve diferença (p > 0,05) entre os grupos, variando de 67,05 a 78,19% e de 78,70 a 84,88%, respectivamente. As dietas de Diamante Negro e Talismã promoveram redução da glicemia de 30 e 26%, respectivamente, em relação à caseína, não sendo, porém, significativa; não houve diferença (p > 0,05) entre os grupos quanto aos níveis séricos de colesterol e triacilgliceróis. Assim, de acordo com as necessidades apresentadas pelas populações, suas demandas nutricionais e funcionais podem ser supridas por diferentes feijões

Geochemistry of Precordillera serpentinites, western Argentina : evidence for multistage hydrothermal alteration and tectonic implications for the Neoproterozoic-early Paleozoic

Serpentinites are a powerful tool to evaluate mantle composition and subsequent alteration processes during their tectonic emplacement. Exposures of this type of rocks can be found in the Argentine Precordillera (Cuyania terrane) and Frontal Cordillera, both located in central-western Argentina, within the Central Andes. In these regions a Neoproterozoic to Devonian mafic-ultramafic belt composed of serpentinites, metabasaltic dikes/sills, pillow lavas (with an Enriched to Normal Mid-Ocean Ridge Basalts (E- to N-MORB) geochemical signature) and mafic granulites crop out, spatially associated with marine metasedimentary rocks. The serpentinite bodies consist of lizardite/chrysotile+brucite+magnetite, with scarce pentlandite and anhedral reddish-brown Cr-spinel (picotite, pleonaste and spinel sensu stricto) as relict magmatic phases. The original peridotites were moderately-depleted harzburgites (ultramafic cumulates) with an intermediate chemical signature between a mid-ocean ridge and an arc-related ophiolite. Whole-rock Rare Earth Elements (REE) patterns of serpentinites exhibit enriched REE patterns ((La/Yb)CN=13-59) regarding CI chondrite with positive Eu anomalies. These features are the result of an interaction between hydrothermal fluid and serpentinites, in which moderate temperature (350º-400ºC), CO2-rich, mildly basic hydrothermal fluid was involved and was responsible for the addition of Ca, Sr and REE to serpentinites. The presence of listvenites (silica-carbonate rocks) in the serpentinite margins allow us to infer another fluid metasomatism, where lowtemperatures (<250ºC), highly-oxidized, highly-acid fluid lead to the precipitation of silica. The association of these metasomatized serpentinite bodies with neoproterozoic continental margin sucessions and MORB magmatism at the suture zone of the Cuyania and Chilenia terranes suggests the development of an oceanic basin between them during the Neoproterozoic-early Paleozoic

The central structure of Broad Absorption Line QSOs: observational characteristics in the cm-mm wavelength domain

Accounting for ~20% of the total QSO population, Broad Absorption Line QSOs are still an unsolved problem in the AGN context. They present wide troughs in the UV spectrum, due to material with velocities up to 0.2 c toward the observer. The two models proposed in literature try to explain them as a particular phase of the evolution of QSOs or as normal QSOs, but seen from a particular line of sight. We built a statistically complete sample of Radio-Loud BAL QSOs, and carried out an observing campaign to piece together the whole spectrum in the cm wavelength domain, and highlight all the possible differences with respect to a comparison sample of Radio-Loud non-BAL QSOs. VLBI observations at high angular resolution have been performed, to study the pc-scale morphology of these objects. Finally, we tried to detect a possible dust component with observations at mm-wavelengths. Results do not seem to indicate a young age for all BAL QSOs. Instead a variety of orientations and morphologies have been found, constraining the outflows foreseen by the orientation model to have different possible angles with respect to the jet axis

Prevalence of sexually transmitted infections in women attending antenatal care in Tete province, Mozambique

Objective. To determine the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and syphilis in pregnant women. Methods. A cross-sectional study was conducted among women attending antenatal care clinics (ANCs). Blood samples were tested for syphilis using the rapid plasma reagin (RPR) and treponemal haemagglutination (TPHA) tests; CT and NG were diagnosed using a manual polymerase chain reaction assay on first-void urine samples. A socio-demographic questionnaire was completed. Results were compared with previous published data on sexually transmitted infection (STI) prevalence in Mozambique. Results. Blood and urine samples were collected from 1 119 and 835 women, respectively. The prevalence of CT was 4.1%, and that of NG 2.5%. The RPR test was positive in 5.2% of the women, and 7.1% had a positive TPHA test. Active syphilis was found in 4.7%. In univariate analysis, CT was associated with having had any level of education (

In vivo reconstitution of a homodimeric cytochrome b559 like structure: The role of the N-terminus a-subunit from Synechocystis sp. PCC 6803

The cytochrome b559 is a heme-bridged heterodimeric protein with two subunits, a and ß. Both subunits from Synechocystis sp. PCC 6803 have previously been cloned and overexpressed in Escherichia coli and in vivo reconstitution experiments have been carried out. The formation of homodimers in the bacterial membrane with endogenous heme was only observed in the case of the ß-subunit (ß/. ß) but not with the full length a-subunit. In the present work, reconstitution of a homodimer (a/. a) cytochrome b559 like structure was possible using a chimeric N-terminus a-subunit truncated before the amino acid isoleucine 17, eliminating completely a short amphipathic a-helix that lays on the surface of the membrane. Overexpression and in vivo reconstitution in the bacteria was clearly demonstrated by the brownish color of the culture pellet and the use of a commercial monoclonal antibody against the fusion protein carrier, the maltoside binding protein, and polyclonal antibodies against a synthetic peptide of the a-subunit from Thermosynechococcus elongatus. Moreover, a simple partial purification after membrane solubilization with Triton X-100 confirmed that the overexpressed protein complex corresponded with the maltoside binding protein-chimeric a-subunit cytochrome b559 like structure. The features of the new structure were determined by UV-Vis, electron paramagnetic resonance and redox potentiometric techniques. Ribbon representations of all possible structures are also shown to better understand the mechanism of the cytochrome b559 maturation in the bacterial cytoplasmic membrane

Whole transcriptome approach to evaluate the effect of aluminium hydroxide in ovine encephalon

Aluminium hydroxide adjuvants are crucial for livestock and human vaccines. Few studies have analysed their effect on the central nervous system in vivo. In this work, lambs received three different treatments of parallel subcutaneous inoculations during 16 months with aluminium-containing commercial vaccines, an equivalent dose of aluminium hydroxide or mock injections. Brain samples were sequenced by RNA-seq and miRNA-seq for the expression analysis of mRNAs, long non-coding RNAs and microRNAs and three expression comparisons were made. Although few differentially expressed genes were identified, some dysregulated genes by aluminium hydroxide alone were linked to neurological functions, the lncRNA TUNA among them, or were enriched in mitochondrial energy metabolism related functions. In the same way, the miRNA expression was mainly disrupted by the adjuvant alone treatment. Some differentially expressed miRNAs had been previously linked to neurological diseases, oxidative stress and apoptosis. In brief, in this study aluminium hydroxide alone altered the transcriptome of the encephalon to a higher degree than commercial vaccines that present a milder effect. The expression changes in the animals inoculated with aluminium hydroxide suggest mitochondrial disfunction. Further research is needed to elucidate to which extent these changes could have pathological consequences