A Genetic Algorithm for Power-Aware Virtual Machine Allocation in Private Cloud

Energy efficiency has become an important measurement of scheduling algorithm for private cloud. The challenge is trade-off between minimizing of energy consumption and satisfying Quality of Service (QoS) (e.g. performance or resource availability on time for reservation request). We consider resource needs in context of a private cloud system to provide resources for applications in teaching and researching. In which users request computing resources for laboratory classes at start times and non-interrupted duration in some hours in prior. Many previous works are based on migrating techniques to move online virtual machines (VMs) from low utilization hosts and turn these hosts off to reduce energy consumption. However, the techniques for migration of VMs could not use in our case. In this paper, a genetic algorithm for power-aware in scheduling of resource allocation (GAPA) has been proposed to solve the static virtual machine allocation problem (SVMAP). Due to limited resources (i.e. memory) for executing simulation, we created a workload that contains a sample of one-day timetable of lab hours in our university. We evaluate the GAPA and a baseline scheduling algorithm (BFD), which sorts list of virtual machines in start time (i.e. earliest start time first) and using best-fit decreasing (i.e. least increased power consumption) algorithm, for solving the same SVMAP. As a result, the GAPA algorithm obtains total energy consumption is lower than the baseline algorithm on simulated experimentation.Comment: 10 page

Development of a Filament Extruder Using Flow Theory with the Newtonian Fluid Assumption

This article presents an investigation of the flow characteristics of the polymer melt in a single-screw extruder and the design of a filament extruder to verify the above theory. The flow characteristics of the polymer melt in a single-screw extruder are likable to that of a viscous liquid between two infinitely parallel sheets, one moving and the other stationary. An integrated flow equation was then found for a case when the viscosity of a liquid remains constant in an isothermal extrusion. These flow behavior theories were then verified via the design and fabrication of a filament extruder for 3D printers

Development of a Filament Extruder Using Flow Theory with the Newtonian Fluid Assumption

This article presents an investigation of the flow characteristics of the polymer melt in a single-screw extruder and the design of a filament extruder to verify the above theory. The flow characteristics of the polymer melt in a single-screw extruder are likable to that of a viscous liquid between two infinitely parallel sheets, one moving and the other stationary. An integrated flow equation was then found for a case when the viscosity of a liquid remains constant in an isothermal extrusion. These flow behavior theories were then verified via the design and fabrication of a filament extruder for 3D printers

INVESTIGATING THE IMPACT OF PEER FFEDBACK AND TEACHER FEEDBACK USING GOOGLE DOCS ON EFL STUDENTS’ WRITING PERFORMANCE

Online written corrective feedback via Google Docs, in recent years, has been used and brought about positive outcomes in different teaching contexts. In this light, this study was conducted to examine the different effects between teacher feedback using Google Docs and the combined peer feedback and teacher feedback using Google Docs on EFL high school students’ performance in writing paragraphs. The study also attempted to gain insights into students’ attitudes towards the effect of peer feedback and teacher feedback using Google Docs on their paragraph writing. In this study, a mixed research method was employed; both quantitative and qualitative data were collected. Twenty two grade 11 students in a high school in the Mekong Delta of Vietnam were selected as participants. They were assigned to two groups of treatment: the experimental group, receiving both peer feedback and teacher feedback using Google Docs and the control group who only received teacher feedback using Google Docs. Participants completed two writing tasks; each of them included first draft, second draft and final draft. Prior to the study, students from the experimental group received a face-to-face training on giving peer feedback. Data were collected from six drafts of two writing tasks, three drafts for one task, and interviews at the end of the study. Results indicated that participants who received teacher feedback in the control group performed their paragraph writing better than those receiving both peer feedback and teacher feedback using Google Docs in the experimental group after the study. Also, participants in both groups improved their writing performance in their revised drafts. From the interviews, results showed participants’ positive attitudes towards the impact of peer feedback and teacher feedback using Google Docs on their paragraph writing.   Article visualizations

Cerebral Collateral Circulation in Carotid Artery Disease

Carotid artery disease is common and increases the risk of stroke. However, there is wide variability on the severity of clinical manifestations of carotid disease, ranging from asymptomatic to fatal stroke. The collateral circulation has been recognized as an important aspect of cerebral circulation affecting the risk of stroke as well as other features of stroke presentation, such as stroke patterns in patients with carotid artery disease. The cerebral circulation attempts to maintain constant cerebral perfusion despite changes in systemic conditions, due to its ability to autoregulate blood flow. In case that one of the major cerebral arteries is compromised by occlusive disease, the cerebral collateral circulation plays an important role in preserving cerebral perfusion through enhanced recruitment of blood flow. With the advent of techniques that allow rapid evaluation of cerebral perfusion, the collateral circulation of the brain and its effectiveness may also be evaluated, allowing for prompt assessment of patients with acute stroke due to involvement of the carotid artery, and risk stratification of patients with carotid stenosis in chronic stages. Understanding the cerebral collateral circulation provides a basis for the future development of new diagnostic tools, risk stratification, predictive models and new therapeutic modalities. In the present review we discuss basic aspects of the cerebral collateral circulation, diagnostic methods to assess collateral circulation, and implications in occlusive carotid artery disease

Circulating syndecan-1 is reduced in pregnancies with poor fetal growth and its secretion regulated by matrix metalloproteinases and the mitochondria

Fetal growth restriction is a leading cause of stillbirth that often remains undetected during pregnancy. Identifying novel biomarkers may improve detection of pregnancies at risk. This study aimed to assess syndecan-1 as a biomarker for small for gestational age (SGA) or fetal growth restricted (FGR) pregnancies and determine its molecular regulation. Circulating maternal syndecan-1 was measured in several cohorts; a large prospective cohort collected around 36 weeks' gestation (n = 1206), a case control study from the Manchester Antenatal Vascular service (285 women sampled at 24-34 weeks' gestation); two prospective cohorts collected on the day of delivery (36 + 3-41 + 3 weeks' gestation, n = 562 and n = 405 respectively) and a cohort who delivered for preterm FGR (< 34 weeks). Circulating syndecan-1 was consistently reduced in women destined to deliver growth restricted infants and those delivering for preterm disease. Syndecan-1 secretion was reduced by hypoxia, and its loss impaired proliferation. Matrix metalloproteinases and mitochondrial electron transport chain inhibitors significantly reduced syndecan-1 secretion, an effect that was rescued by coadministration of succinate, a mitochondrial electron transport chain activator. In conclusion, circulating syndecan-1 is reduced among cases of term and preterm growth restriction and has potential for inclusion in multi-marker algorithms to improve detection of poorly grown fetuses

Natural-based nanocomposites for bone tissue engineering and regenerative medicine: a review

Tissue engineering and regenerative medicine has been providing exciting technologies for the development of functional substitutes aimed to repair and regenerate damaged tissues and organs. Inspired by the hierarchical nature of bone, nanostructured biomaterials are gaining a singular attention for tissue engineering, owing their ability to promote cell adhesion and proliferation, and hence new bone growth, compared with conventional microsized materials. Of particular interest are nanocomposites involving biopolymeric matrices and bioactive nanosized fi llers. Biodegradability, high mechanical strength, and osteointegration and formation of ligamentous tissue are properties required for such materials. Biopolymers are advantageous due to their similarities with extracellular matrices, specifi c degradation rates, and good biological performance. By its turn, calcium phosphates possess favorable osteoconductivity, resorbability, and biocompatibility. Herein, an overview on the available natural polymer/calcium phosphate nanocomposite materials, their design, and properties is presented. Scaffolds, hydrogels, and fi bers as biomimetic strategies for tissue engineering, and processing methodologies are described. The specifi c biological properties of the nanocomposites, as well as their interaction with cells, including the use of bioactive molecules, are highlighted. Nanocomposites in vivo studies using animal models are also reviewed and discussed.  The research leading to this work has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS, and from QREN (ON.2 - NORTE-01-0124-FEDER-000016) cofinanced by North Portugal Regional Operational Program (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)

Survey, collection and characterization of indigenous and non-indigenous cucurbits in Vietnam

Die Pflanzenfamilie Cucurbitaceae ist sehr vielfältig und viele Arten haben eine wirtschaftliche Bedeutung. Die Untersuchungen konzentrierten sich auf die Analyse von Cucurbitaceen im Rahmen des Gemüseanbaus; auf die Sammlung von Keimplasma im südlichen Vietnam; die Charakterisierung von Akzessionen der Cucurbitaceen; und die Ermittlung von stabilen Merkmalen zur Klassifizierung von Akzessionen des Bitterkürbis. Es erfolgte eine Umfrage im Mekong Delta zur Verbreitung von Cucurbitaceen; es wurden Akzessionen im südlichen Vietnam für die Genebank gesammelt; 160 Akzessionen von fünf gesammelten Arten der Cucurbitaceen wurden anhand von morphologischen Eigenschaften analysiert. Eine Berechnung der Eigenvektoren, UPGMA Methode und 3D-bi-Plots machte die Beziehungen zwischen den Akzessionen sichtbar; 28 Eigenschaften von sieben Bitterkürbiss Akzessionen wurden hinsichtlich der Merkmalsstabilität unter Freiland- und Gewächshausbedingungen bewertet. Es wurden der ‚Two-sample‘ Test, Korrelationstest und UPGMA Methode zur Ermittlung der Stabilität morphologischer Merkmale herangezogen. Bei den Befragungen wurde ermittelt, dass 9 Arten von Cucurbitaceen für den Markt angebaut wurden, mehr als 45% Bauern kultivierten Cucurbitaceen auf 56,5% der für den Gemüseanbau genutzten Fläche. Es wurden 244 Akzessionen mit 14 Arten der Cucurbitaceen die zu 12 Gattungen gehörten in 24 Provinzen im südlichen Vietnam gesammelt, wesentliche Informationen zu ihrer genetischen Beziehung sind verfügbar. Es wurde deutlich, dass 12 Merkmale zur stabilen Charakterisierung des Bitterkürbis geeignet sind und damit zur Einschätzung der genetischen Beziehungen zwischen den Akzessionen.Cucurbitaceae is highly diverse and many species in this plant family are of economic importance. The study was focused to analyse cucurbit species in vegetable cultivation; to collect cucurbit germplasm in southern Vietnam; to characterize cucurbit germplasm; and to determine the stable characteristics for classifying bitter gourd accessions. A survey was carried out in Mekong River Delta; Cucurbit germplasm was collected in southern Vietnam; 160 accessions of five collected cucurbit species were analysed based on morphological characteristics. Calculating the eigenvectors, UPGMA method, and 3D bi-plots resulted in clear relationships of the accessions; 28 characteristics of seven bitter gourd accessions were evaluated for its stability in two different growing conditions. Two-sample test, correlation test, and UPGMA method were used to determine the stable characteristics. In result of this study, 9 cucurbit species cultivated for commercial market were determined, whereas more than 45% farmers produced cucurbits. Land used for cultivating cucurbits covered 56.5% of total area of vegetable cultivation. 244 accessions of 14 cucurbit species belonging to 12 Cucurbitaceae genera were collected in 24 provinces in southern Vietnam. The evaluated characteristics provided essential information for understanding the genetic relationships of the accessions that were collected in different regions. Regarding stable characteristics, these data suggested that 12 characteristics were useful for evaluating genetic relationships of bitter gourd accessions

Experimental Study on the Use of the Modifying Agent for Expansive Soil Stabilization: Mockup Test on a Case Study

To improve the soft grounds, soil stabilization has been used widely in many tropical countries including Vietnam. This paper presents the experimental study on the use of the modifying agent for expansive soil stabilization. A real-scale one-kilometer rural road was used for the experimental test. It was divided into four parts, and each part was subjected to different stabilization tests. The specimens extracted from every quarter were denominated as Q1 (soil + cement), Q2 (soil + cement + fly ash), Q3 (soil + cement + fly ash + modifying agent) and Q4 (soil + cement + modifying agent). The assessment test showed that specimen Q1 yielded the highest water absorption percentage after 24 hours and 72 hours of soaking. The longer the soaking time, the more water diffusion occurred at specimens Q1 and Q2 rather than at specimens Q3 and Q4. When subjected to the unconfined compressive and indirect tensile tests, specimens Q1 and Q3 yielded the lowest and highest strength, respectively. The use of the modifying agent in the specimens Q3 and Q4 has improved noticeably unconfined compressive strength, indirect tensile strength, and water stability compared to the specimens Q1 and Q2. However, ettringite-based sulfate heaving might be exhibited with the use of fly ash, this may cause damage to the overlying pavement structure in the long term. Therefore, to improve the expansive soil stabilization using the modifying agent, it is recommended to use the constituent materials in specimen Q4 rather than in Q3