bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtención de Betacianinas de la Remolacha (Beta vulgaris)
Authors: Salazar Llangari Karina Gabriela , Flores Linda Mariuxi , Coba Carrera Raquel Leticia , Brito Moina Hanníbal Lorenzo
Published: September 2019

Este trabajo de investigación permitió evaluar el efecto de la micro encapsulación del pigmento de betacianinas de la remolacha a través de la operación unitaria de secado por atomización, para su uso como colorante natural, para lo cual, se obtuvo el extracto de betanínas mediante la utilización de un equipo de extracción, luego filtración, posteriormente se procedió con la microencapsulación con maltodextrina a concentraciones (10%, 25%, 50%, 75% y 100%) y se secó en el secador por atomización a diferentes temperaturas (120 °C, 140 °C y 160 °C), el pigmento obtenido fue caracterizado, identificando sus propiedades funcionales y fisicoquímicas; con respecto a la higroscopicidad (%), solubilidad (%), humedad (%), densidad (g/cm3 ). El proceso óptimo de secado por atomización fue establecido luego de los ensayos realizados: temperatura del aire de entrada de 120°C y una concentración de encapsulante del 50%P/P. Obteniendo un producto con una humedad del 3 ± 0,05%, higroscopia 4,05 ± 0,01% y un rendimiento de recuperación de solidos del 72,73± 0,04%. Estos resultados evidencian que el producto así obtenido cumple con los estándares del cardex alimentario para la obtención de colorante naturales en polvo.
La Comprensión Lectora de textos técnicos del idioma inglés para el aprendizaje mediante el uso de técnicas pedagógicas
Authors: Colcha Guashpa Esthela Isabel , Herrera Andrade Zoila Victoria , Barragán Murillo Rocío de los Ángeles , Guano Daniela Fernanda
Published: September 2019

Al hablar de la comprensión lectora podemos decir que es el proceso mediante el cual un lector construye, a partir de su conocimiento previo, nuevos significados cuando interactúa con el texto, siendo esta la base del entendimiento hacia la interacción del lector con el texto. Este proceso se desarrolla de manera diferente en cada lector, ya que cada individuo tiende a diferentes esquemas y usa sus destrezas y habilidades cuando enfrenta un texto. La experiencia previa es importante, porque esta será determinante en el número de esquemas que posee cada persona, es decir si la experiencia es limitada, también lo harán los esquemas. De ser el caso en que un lector no tiene un esquema definido relacionado con ningún tema o concepto en particular, se puede formar uno nuevo con la información provista, sea esta de los textos utilizados para el aprendizaje del idioma inglés, siendo su texto entendido de varias maneras. lo cual implica formulación de juicios sobre valores presentados en un texto o inferencial en donde se comprende la lectura es decir se entiende lo que se quiere decir. De esta forma, En este documento se revisarán varios términos relacionados con la temática principal entregando una mayor visión al lector para su conocimiento.
Measuring Sovereign Risk With Contingent Claims Analysis: The Empirical Evidence in Southeast Asia Credit Markets
Authors: Ho Hong Hai , Tran Duy Long
Published: September 2019

This paper focuses on examining the degree to which the Contingent Claims Analysis is useful for Southeast Asia markets. Such a framework is initially developed for analyzing corporate sector default based on the theory of Black-Scholes options pricing and the structure of accounting balance sheet, and then adapted to the sovereign balance sheet in a way that can help forecast credit spreads and evaluate the impacts of risk transferred from other sectors. Robustness checks indicate that sovereign CCA is consistent with most markets in the sample. Scenario analysis interprets two prospects with assumptions on economic growth and capital structure of the Vietnam government in the short-term future.
SOSYAL HİZMET LİSANS ÖĞRENCİLERİNİN EVLAT EDİNME YOLUYLA KURULMUŞ TEK EBEVEYNLİ AİLELER HAKKINDAKİ GÖRÜŞ VE DÜŞÜNCELERİ: KOCAELİ ÜNİVERSİTESİ ÖRNEĞİ
Authors: Aslantürk Hüsnünur , Koç Faruk
Published: September 2019

Tek
anne ya da baba ve çocuklardan oluşan tek ebeveynli ailelerin sayısı gün
geçtikçe artmaktadır. Çoğunlukla boşanma ya da eşlerden birinin vefatı
sonucunda oluşan tek ebeveynli aileler bekâr kimselerin evlat edinmeleri yolu
ile kurulabilmektedir. Evlat edinme yoluyla kurulan tek ebeveynli ailelerin
oluşması noktasında, meslek hayatlarına başladıklarında karar verici konumda
yer alma ihtimalleri nedeniyle sosyal hizmet öğrencilerinin görüş ve düşünceleri
önem taşımaktadır. Bu çerçevede çalışmanın amacı sosyal hizmet mesleğinin etik
ilke ve değerleri çerçevesinde eğitim almakta olan sosyal hizmet lisans
öğrencilerinin evlat edinme yoluyla kurulmuş tek ebeveynli aileler hakkındaki
görüş ve düşüncelerinin belirlenmesidir. Kocaeli Üniversitesi Sosyal Hizmet
Bölümü örnekleminde gerçekleştirilen bu çalışmaya 156 lisans öğrencisi dâhil
edilmiştir. Katılımcıların büyük bir bölümü kadın (%73.7) ve tümü 18-24 yaş
aralığındadır.  Çalışmanın sonucunda
çalışmaya katılan öğrencilerin çoğunluğunun (%50,8) bekâr kimselere oranla anne
ve babanın bir arada bulunduğu ailelerin evlat edinme yoluna başvurmaları
gerektiğini düşündükleri görülmüştür. Diğer yandan katılımcıların %80,1’lik
bölümü evlat edinme sürecinde her iki taraf adına da şartların eşit olması
gerektiğini ifade etmişlerdir. Ayrıca ileride evlat edinmek isteyen bekâr
kimselerle meslek yaşantılarında karşılaşmaları durumunda, öğrencilerin
çoğunluğunun mesleki ilke ve değerleri uygulamakta zorluk çekmeyeceği (%58,3),
bir bölümünün ise (%38,5) zorluk çekse bile mesleki ilke ve değerleri
uygulayacağı sonucuna varılmıştır.
BİR MÜCADELE PRATİĞİ OLARAK SOSYAL HİZMET UZMANLARININ ÖRGÜTLENME DENEYİMLERİ: İSTANBUL İLİ KAPSAMINDA BİR ANALİZ
Authors: Karçal Fırat
Published: September 2019

Dünya genelinde sosyal hizmetin mesleki ve
akademik bir nitelik kazanması ve sunulan hizmetlerin yaygınlaşan sosyal
sorunlara çözüm üretecek biçimde düzenlenmesi ihtiyacı, kapitalizmin toplumsal
yaşamdaki belirleyiciliğinin artmasıyla görünür olmaktadır. Bu çalışma
kapitalist üretim ilişkilerinin toplumsal yaşama egemen olmasıyla birlikte
artan ve derinleşen sosyal sorunların çözümü amacıyla, multidisipliner yaklaşım
ve tekniklerle uygulamalar gerçekleştiren sosyal hizmet uzmanlarının,
örgütlenme süreçlerini ve örgütlülüğü sürdürme nedenlerini İstanbul ili
ölçeğinde incelemeyi amaçlamaktadır. Bu amaçla İstanbul'da çeşitli kurumlarda
çalışan 34 sosyal hizmet uzmanıyla yarı yapılandırılmış görüşme formu
aracılığıyla derinlemesine görüşmeler yapılmıştır. Araştırmadan elde edilen bulgular,
sosyal hizmet uzmanlarının lisans eğitimleri ve meslekleriyle ilgili diğer
eğitimlere uygun olarak örgütlü olmanın sosyal hizmet mesleğinin ve disiplinin
gelişmesine katkısı olduğunu, örgütlü olmanın çalışma koşulları ve özlük
hakları açısından kazanımlar sağladığını, yürürlükte bulunan sosyal politikalara
müdahale ihtiyacının örgütlü olmayı gerektirdiğini ortaya koymaktadır. 
SOSYAL HİZMET SÜPERVİZYONU VE TÜRKİYE İÇİN ÖNERİLER
Authors: Şahin Taşğın Neşe
Published: September 2019

Süpervizyon, meslekleşme sürecinin başlangıcından bu yana sosyal
hizmetin ayrılmaz bir parçası olarak kabul edilmektedir. Sosyal hizmetin
geliştiği ülkelerin çoğunda, üniversitelerin sosyal hizmet bölümlerinde, sosyal
hizmet sunulan kurumlarda (kamu ya da özel) ve meslek örgütlerinde süpervizyona
ilişkin standartlar bulunmaktadır. Türkiye’de ise, süpervizyon sosyal hizmet
lisans ve lisansüstü eğitimi süreçleri dışında gündeme gelmemiştir. Ülkemizde,
sosyal hizmet uzmanlarının süpervizyon ihtiyacı ve sosyal hizmet bölümlerinin
sayısının artması nedeniyle, hem sosyal hizmet uzmanları hem de öğrencilere
yönelik süpervizyon konusunda bilgi üretmeye ve araştırma yapmaya ihtiyaç
bulunmaktadır. Bu ihtiyaçtan hareketle makalede, ilk olarak, sosyal hizmet
süpervizyonunun tanımı, tarihsel gelişimi, yaklaşımlar ve güncel tartışmalar
özetlenmiştir. Ardından da Türkiye’de süpervizyon sisteminin geliştirilmesi
için öneriler sunulmuştur.
KRONİK HASTALIKLARLA BAŞ ETMEDE ÇOKLU AİLE GRUBU TERAPİSİ UYGULAMALARI
Authors: Pak Merve Deniz
Published: September 2019

Bireylerin
iyilik halleri üzerinde ciddi sorunlar yaratan kronik hastalıklar, çoğunlukla
yaşam boyu devam eden tedavini sürecini gerektirmektedir. Bu durum, bireylerin
aile yaşamları üzerinde önemli etkiler yaratmaktadır. Hastalık gibi aile yaşam
döngüsünün seyri üzerindeki bu etkiler karşısında ailenin karşılaştıkları yeni
ve farklı durumlarda sağlıklı olarak işlevini sürdürmesi gereklidir. Bu işlevin
yerine getirilmesinde de çoklu aile grubu terapisi son yıllarda dikkat çeken
uygulama alanlarından biri olmuştur. Çoklu aile grubu terapisi, özellikle
kronik hastalıkların bulunduğu ailelerde grup ortamında birden fazla ailenin
görüldüğü terapiyi tanımlamak için kullanılan bir terimdir. Bu çalışmada çoklu
aile grubu terapisi temel kavramları ve uygulama alanları çerçevesinde ele
alınmaktadır.
When Protagoras Made Aristotle His Fitch
Authors: McCready-Flora Ian
Published: September 2019

While defending the principle of non-contradiction in Metaphysics 4, Aristotle argues that the Measure Doctrine of Protagoras is equivalent to the claim that all contradictions are true; given all appearances are true (as the Protagorean maintains), anytime people disagree we get a true contradiction. This argument seems clearly invalid: nothing guarantees that actual disagreement occurs over every matter of fact. The argument in fact works perfectly, I propose, because the Protagorean view falls prey to a version of Fitch's “paradox” of knowability. The proposed reading shows how Aristotle treats the Protagorean view at issue as an epistemic theory of truth distinct from the mere claim that all appearances are true (which other opponents put forward on different grounds) and reveals Aristotle's underlying concern with the modal collapse of possibility into actuality. The revised Protagorean view Aristotle confronts in a subsequent chapter is furthermore best understood as an attempt to avoid this Fitch-style result.
Aristotle for the Modern Ethicist
Authors: Connell Sophia
Published: September 2019

Elizabeth Anscombe and Mary Midgley discussed Aristotle's ethics as an alternative to modern moral philosophy. This idea is best known from Anscombe's 1958 paper ‘Modern Moral Philosophy’. The mainstream response has been to design a normative theory of ‘virtue ethics’ to rival deontology and consequentialism. This essay argues that that response is inadequate; it misses Anscombe's point and obscures various aspects of Aristotle's ethics, in particular his emphasis on friendship and human interconnectedness. This element of Aristotelianism was favoured by Midgley. By returning to Midgley, with the support of Aristotle, it is possible to find an alternative modern Aristotelianism in ethics.
The Contribution of Thomas Carlyle to British Idealism, c. 1880–1930
Authors: Jordan Alexander
Published: September 2019

That the great Scottish man of letters Thomas Carlyle (1795–1881) exercised a formative influence over the ‘British Idealism’ of the late nineteenth and early twentieth centuries has long been noted by historians. However, this has been done so in passing, on the basis of a small fraction of the relevant source material. Through a close, comprehensive and sustained analysis of the entire corpus of relevant sources, the current article demonstrates that the British Idealists considered Carlyle to be far and away the most important British (Scottish) thinker of the nineteenth century, and considered themselves to be his heirs in almost every sense imaginable. Indeed, this is true of their theology, their ethics and their social and political thought.
The Second Edition of Cowper's Homer
Authors: Widmer Matthias
Published: September 2019

This discussion looks in some depth at the heavily revised second edition, posthumously published in 1802, of Cowper's translation of Homer. For editors and critics it has never displaced the first edition of 1791, yet Cowper's revisions served to correct many of the flaws they diagnosed. It is argued that Cowper's increasing responsiveness to criticism by laymen and scholars alike was neither a symptom of his deteriorating mental state, as Robert Southey claimed, nor a mere expression of his desire to appease hostile reviewers, but rather an extension of the same collaborative modus operandi that helped him produce the translation in the first place. The lack of scholarly attention to the 1802 edition has, until now, prevented proper understanding of Cowper's achievement in translating the Homeric epics.
MALATYA İLİNDE GELENEKSEL BAĞCILIK UYGULAMALARI
Authors: MACİT Tahir , ÇÖÇEN Erdoğan , ERNİM Cemil , GÜLTEKİN Nedim , YANAR Makbule , SARITEPE Yüksel
Published: September 2019

Geleneksel kavramlar ve uygulamalar ülkeler için tarihi miras niteliğindedir. Pek çok uygarlığa ev sahipliği yapan Anadolu, tarımsal alanda oldukça zengin bir kültürel mirasa sahiptir. Ülkemizde geleneksel giyim kuşam, geleneksel gıdaların üretimi ve geleneksel mimari uygulamalarının derlenmesi ve muhafazasına yönelik pek çok çalışma yapılmıştır. Ancak geleneksel tarım tekniklerinin derlenmesine yönelik çalışmalar sınırlı düzeydedir. Oysa somut olmayan kültürel miraslardan olan bu tarımsal birikimin derlenerek muhafaza edilmesi önem arz etmektedir. Ülkemizin önemli meyvecilik merkezlerinden olan Malatya ilinde bağcılığın tarihi çok eskilere dayanmaktadır. İlde gerçekleştirilen arazi çalışmalarında ve çiftçi ziyaretlerinde geleneksel bağcılıkta çok farklı budama yöntemlerinin, dikim, hasat ve bakım tekniklerinin, kelime ve kavramların kullanıldığı görülmüştür. Tarım ve Orman Bakanlığı’nca desteklenen ve 2014-2016 yılları arasında yürütülen bu çalışmada Malatya ili geleneksel bağcılığında uygulanan kültürel işlemler ile terim ve kavramların derlenerek muhafazası amaçlanmıştır. Çalışmanın materyalini ilde geleneksel yöntemlerle bağcılık yapan üreticilerden elde edilen bilgiler oluşturmuştur. Bu bilgiler, ilde geleneksel bağcılığın yoğun olarak yapıldığı Battalgazi, Yeşilyurt, Arapkir ve Doğanşehir ilçelerinde belirlenen üreticilerle yüz yüze görüşmeler yapılarak derlenmiştir. Çalışma sonunda geleneksel bağcılıkta kullanıldığı belirlenen 37 farklı terim ve kavram güncel anlamlarıyla birlikte kayıt altına alınmıştır. Ayrıca geleneksel bağcılıkta uygulanan bağ tesisi, budama yöntemleri, zirai mücadele ile kurutma ve depolama teknikleri de derlenmiştir.
Review of Communication: A Post-Discipline, by Silvio R. Waisbord
Authors: Pooley Jefferson
Published: September 2019

A reprint of a forthcoming book review of Communication: A Post-Discipline, by Silvio R. Waisbord, to appear in Communications: The European Journal of Communication Research.
POPULISM AND PUBLICITY: THE PARTICIPANT PERSPECTIVE
Authors: Rostboll Christian
Published: September 2019

It is common to ask whether populism is a threat or a corrective to democracy. In the empirical literature, the conclusion tends to be that it is both. Mouffe’s normative account promotes populism because of its alleged ability to deepen democracy. Both literatures are inhibited by an observer perspective, which evaluates populism as a phenomenon that affects democracy from the outside rather than as an alternative conception of democracy. This paper proposes an alternative approach, which uses the publicity condition of Kant and Rawls. The publicity condition entails taking a participant perspective, where you regard yourself as involved with plural others in a common enterprise of deliberation. While the observer considers the causes and effects of different doctrines in order to explain, manipulate and/or exploit political practice, the participant asks whether we could make a doctrine our own, something we would promote and use to assess the health of democracy.
El Balanced Scorecard en el Desarrollo de los Negocios Familiares
Authors: Mendez Bravo Julio Cesar , Ayala Briones Haybee Jossety , Palacios Sarmiento Tania Yolanda
Published: September 2019

Las empresas familiares son las unidades de negocio más antiguas en el mundo empresarial, este tipo de empresas son de gran importancia dentro de un país porque dinamizan la economía y generan empleo. La subsistencia de este tipo de empresas a largo plazo es muy importante, sin embargo, gran parte de este tipo de negocios familiares llegan a fracasar antes de cumplir los 5 años de vida. Por ello es necesario el desarrollo e implementación de un sistema de gestión que logre identificar los problemas y ayude a mejorarlos, el Balanced Scorecard (BSC) es la herramienta de gestión más adecuada para solucionar problemas y ayudar a gestionar este tipo de organizaciones. El presente trabajo realizo una revisión literaria de investigaciones de alto impacto, permitiendo determinar al BSC como la mejor opción al momento de realizar la planificación y control de las actividades en las organizaciones, mejorando las expectativas de sostenibilidad y crecimiento en las organizaciones.
Evaluación del Modelo de Dimensiones del Aprendizaje Organizacional - DLOQ
Authors: Manosalvas Vaca Carlos Anibal , Palma León Roxanna , Manosalvas Vaca Luis , Aguirre Cecilia
Published: September 2019

El aprendizaje organizacional es uno de los conceptos de mayor relevancia en los últimos años ya que permite la generación de ventajas competitivas para una organización. Sin embargo su operacionalización y medición es objeto de debate a nivel teórico y empírico. En esta investigación se realizó un análisis de confiabilidad y validez a través de un análisis factorial confirmatorio del modelo de Dimensiones del Aprendizaje Organizacional propuesto por Marsick y Watkins, uno de los cuestionarios y modelos más utilizados en varios contextos pero que aún ha sido aplicado muy poco en economías emergentes. Se encuestó a muestra representativa de trabajadores de empresas de tecnología y los resultados permitieron concluir que el instrumento cumple con los criterios de confiablidad, validez convergente y divergente, no obstante no mostró un buen ajuste con los datos.
On Discovery of the Twelfth and Thirteenth New Nondispersive SH-SAWs in 6 mm Magnetoelectroelastics
Authors: Zakharenko Aleksey Anatolievich
Published: September 2019

This report acquaints the reader with an extra two new shear-horizontal surface acoustic waves (SH-SAWs). These new SH-SAWs can propagate along the free surface of the transversely isotropic (6 mm) magnetoelectroelastic materials. These (composite) materials can simultaneously possess the piezoelectric, piezomagnetic, and magnetoelectric effects. Some competition among these effects can lead to suitable solutions found for the following three possible coupling mechanisms: eα – hε, eµ – hα, εµ – α2. Here, the mechanically free interface between the solid and a vacuum was considered. This report discovers the twelfth (thirteenth) new SH-SAW for the magnetically closed (electrically open) case and continuity of both the normal component of the electrical (magnetic) displacement and the electrical (magnetic) potential when the coupling mechanism eα – hε (eµ – hα) works. The propagation velocities were obtained in explicit forms that take into account the contribution of the vacuum material parameters. The discovered waves were then graphically studied for the purpose of disclosing the dissipation phenomenon (the propagation velocity becomes imaginary) caused by the coupling with the vacuum properties. The obtained results can be useful for further investigations of interfacial and plate SH-waves, constitution of technical devices, nondestructive testing and evaluation, and application of some gravitational phenomena.
Carbapenem-Resistant Enterobacteriaceae Posing a Dilemma in Effective Healthcare Delivery
Authors: Oli Angus Nnamdi , Itumo Chimaobi Johnpaul , Okam Princeston Chukwuemeka , Ezebialu Ifeanyichukwu U. , Okeke Kenneth Nchekwube , Ifezulike Christian Chukwuemeka , Ezeobi Ifeanyi , Emechebe George Ogonna , Okezie Ugochukwu Moses , Adejumo Samson A. , Okoyeh Jude Nnaemeka
Published: September 2019

The emergence and spread of Carbapenem-resistant Enterobacteriaceae (CRE) is seriously posing threats in effective healthcare delivery. The aim of this study was to ascertain the emergence of CRE at Chukwuemeka Odumegwu Ojukwu University Teaching Hospital (COOUTH) Awka. Biological samples were collected from 153 consenting patient from 5 clinics in the hospital. The isolates were identified using standard microbiological protocols. Susceptibility to meropenem was done using Kirby-Bauer disc diffusion method on Mueller Hinton Agar. A total of 153 patients were recruited in this study. About one half of those from rural, 63.64% from Sub-urban and 42.27% from urban areas had significant E. coli and Klebsiella spp infections. The male: female ratio of the Enterobacteriaceae infection was 1:1. Almost as much inpatient as outpatient study participants had the infections. The infections were observed mostly on participants with lower educational status. The unmarried individuals were most infected compared to their married counterparts. Enterobacteriaceae infection rate was 50.98%. Of this, 28.21% had CRE infection while the overall prevalence of the CRE in the studied population was 14.38% (22/153). This study shows that CRE is quickly emerging in both community and hospital environments. Klebsiella spp was the most common CRE in this hospital especially Klebsiella oxytoca. Hospitalization was a strong risk factor in the CRE infections. Rapid and accurate detection is critical for their effective management and control.
Phenolic Compounds and Antioxidant Activities of Potato Cultivars with White, Yellow, Red and Purple Flesh
Authors: Ru Weidong , Pang Yuehan , Gan Yuanruo , Liu Qin , Bao Jinsong
Published: September 2019

The contents of total phenolics (TPC), individual phenolic acid and antioxidant activities in the free and bound fractions of potato with different flesh colors were systematically investigated. The TPC and antioxidant capacity in the bound fraction was significantly lower than that in the free fraction. Chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, caffeic acid, p-coumaric acid and ferulic acid were detected in the free fraction with chlorogenic acid being the most predominant, accounting for 35.21–81.78% of the total content. Caffeic acid, p-coumaric acid and ferulic acid were detected in the bound fraction in the colored potato with caffeic acid being the major one. In the free fraction, the content of each individual phenolic acid had positive correlation with antioxidant activity. In the bound fraction, caffeic acid and p-coumaric acid showed positive correlation with antioxidant activity. This study promotes further understanding of the correlations among TPC, phenolic acids and antioxidant activity.
Combined Treatment with Three Natural Antioxidants Enhances Neuroprotection in a SH-SY5Y 3D Culture Model
Authors: Marrazzo Pasquale , Angeloni Cristina , Hrelia Silvana
Published: September 2019

Currently, the majority of cell-based studies on neurodegeneration are carried out on two-dimensional cultured cells that do not represent the cells residing in the complex microenvironment of the brain. Recent evidence has suggested that three-dimensional (3D) in vitro microenvironments may better model key features of brain tissues in order to study molecular mechanisms at the base of neurodegeneration. So far, no drugs have been discovered to prevent or halt the progression of neurodegenerative disorders. New therapeutic interventions can come from phytochemicals that have a broad spectrum of biological activities. On this basis, we evaluated the neuroprotective effect of three phytochemicals (sulforaphane, epigallocatechin gallate, and plumbagin) alone or in combination, focusing on their ability to counteract oxidative stress. The combined treatment was found to be more effective than the single treatments. In particular, the combined treatment increased cell viability and reduced glutathione (GSH) levels, upregulated antioxidant enzymes and insulin-degrading enzymes, and downregulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 and 2 in respect to peroxide-treated cells. Our data suggest that a combination of different phytochemicals could be more effective than a single compound in counteracting neurodegeneration, probably thanks to a pleiotropic mechanism of action.
Alpha-Glucosidase and Alpha-Amylase Inhibitory Activities of Novel Abietane Diterpenes from Salvia africana-lutea
Authors: Etsassala Ninon G.E.R. , Badmus Jelili A. , Waryo Tesfaye T. , Marnewick Jeanine L. , Cupido Christopher N. , Hussein Ahmed A. , Iwuoha Emmanuel I.
Published: September 2019

The re-investigation of a methanolic extract of Salvia africana-lutea collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (1), 3β-acetoxy-7α-methoxyrosmanol (2), 19-acetoxy-7α-methoxyrosmanol (3), 19-acetoxy-12-methoxy carnosol (4), and two known named clinopodiolides A (5), and B (6), in addition to four known triterpenes, oleanolic, and ursolic acids (7, 8), 11,12-dehydroursolic acid lactone (9) and β-amyrin (10). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of 8, 10, and 7, with the half inhibitory concentration (IC50) values of 11.3 ± 1.0, 17.1 ± 1.0 and 22.9 ± 2.0 µg/mL, respectively, while 7 demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC50 of 12.5 ± 0.7 µg/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of S. africana-lutea is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.
Value-Oriented Requirements: Eliciting Domain Requirements from Social Network Services to Evolve Software Product Lines
Authors: Ali Nazakat , Hong Jang-Eui
Published: September 2019

Social network services allow a large population of end-users of software products to publicly share their concerns and experiences about software systems. From a software engineering perspective, such data can be collected and analyzed to help software development organizations to infer users’ emerging demands, receive their feedback, and plan the rapid evolution of software product lines. For the evolution of software product lines, organizations supplement emerging requirements in their products to meet user’s needs and also to retain their dominance in the market. Therefore, social network services, being a communication channel, have supported a number of software development activities such as requirements engineering. It has supported software development organizations to cope with numerous limitations of the traditional requirements engineering approaches by eliciting, prioritizing, and negotiating user requirements. However, these approaches do not consider eliciting requirements in terms of variability and commonality while identifying requirements. To address this issue, we have proposed a social network service-based requirement engineering process. It considers the attributes of users’ opinions to determine variability and commonality. In order to justify our proposed approach, a controlled experiment was conducted on a sample set of end-users on Facebook and Twitter. The experimental results show that the team using the proposed approach performed better in terms of efficiency and effectiveness than the team that used a traditional requirements engineering approach.
Dynamic Carrier-Sense Threshold Selection for Improving Spatial Reuse in Dense Wireless LANs
Authors: So Jungmin , Lee Joosang
Published: September 2019

As density of a wireless LAN grows, per-user throughput degrades severely, deteriorating user experience. To improve service quality, it is important to increase system spectral efficiency. Controlling carrier-sense threshold is one of the key techniques to achieve the goal, because frequently transmissions are unnecessarily blocked by carrier sensing, even though these transmissions can take place without causing packet losses. Using high carrier-sense threshold and allowing nodes to transmit aggressively may increase the system throughput, but this approach can lead to unfair channel share and cause starvation for the edge nodes. In this paper, we propose a medium access control protocol where transmitters include the carrier-sense threshold required to protect its packet in the preamble. Nodes receiving the preamble only transmit concurrently, when they are confident that their own transmission as well as the on-going transmission will both be successfully received at the respective receivers. The simulation results show that this dual-threshold approach can achieve higher system throughput compared to using a single carrier-sense threshold, without penalizing edge nodes.
Effects of Surface Roughness and Force of Electrode on Resistance Spot Weldability of Aluminum 6061 Alloy
Authors: Jo Hyeonggeun , Kim Dongcheol , Kang Munjin , Park Junhong , Kim Young-Min
Published: September 2019

The effects of electrode surface roughness and force on the resistance spot weldability and sticking of the electrode during resistance spot welding (RSW) of aluminum 6061-T6 alloy were investigated. RSW was carried out using an as-received electrode and an abraded electrode polished with sandpaper, and the nugget size and properties such as tensile shear strength and hardness of the resulting welds were investigated at two different electrode forces. In addition, a continuous RSW process was performed on the alloy to observe the effect of the electrode surface roughness on electrode sticking. When RSW was performed using the abraded electrode, which had a rough surface, the contact resistance decreased because of the effective removal of the oxide film from the surface of the aluminum alloy; consequently, the heat generated by the resistance on the surface was reduced. In addition, the growth rate of the weld nuggets formed with the abraded electrode in the thickness direction was lower than that of the nuggets formed with the as-received electrode, and the sticking of the abraded electrode was comparatively less. Also, the influence of the electrode force on the sticking of the electrode was greater in the case of the as-received electrode.
Toward Bridging Future Irrigation Deficits Utilizing the Shark Algorithm Integrated with a Climate Change Model
Authors: Ehteram Mohammad , El-Shafie Amr H. , Hin Lai Sai , Othman Faridah , Koting Suhana , Karami Hojat , Mousavi Sayed-Farhad , Farzin Saeed , Ahmed Ali Najah , Bin Zawawi Mohd Hafiz , Hossain Md Shabbir , Mohd Nuruol Syuhadaa , Afan Haitham Abdulmohsin , El-Shafie Ahmed
Published: September 2019

Climate change is one of the most effectual variables on the dam operations and reservoir water system. This is due to the fact that climate change has a direct effect on the rainfall–runoff process that is influencing the water inflow to the reservoir. This study examines future trends in climate change in terms of temperature and precipitation as an important predictor to minimize the gap between water supply and demand. In this study, temperature and precipitation were predicted for the period between 2046 and 2065, in the context of climate change, based on the A1B scenario and the HAD-CM3 model. Runoff volume was then predicted with the IHACRES model. A new, nature-inspired optimization algorithm, named the shark algorithm, was examined. Climate change model results were utilized by the shark algorithm to generate an optimal operation rule for dam and reservoir water systems to minimize the gap between water supply and demand for irrigation purposes. The proposed model was applied for the Aydoughmoush Dam in Iran. Results showed that, due to the decrease in water runoff to the reservoir and the increase in irrigation demand, serious irrigation deficits could occur downstream of the Aydoughmoush Dam.
Sustained Neurotrophin Release from Protein Nanoparticles Mediated by Matrix Metalloproteinases Induces the Alignment and Differentiation of Nerve Cells
Authors: Matsuzaki Yuka , Maruta Rina , Takaki Keiko , Kotani Eiji , Kato Yasuko , Yoshimura Ryoichi , Endo Yasuhisa , Whitty Ciara , Pernstich Christian , Gandhi Raj , Jones Michael , Mori Hajime
Published: September 2019

The spatial and temporal availability of cytokines, and the microenvironments this creates, is critical to tissue development and homeostasis. Creating concentration gradients in vitro using soluble proteins is challenging as they do not provide a self-sustainable source. To mimic the sustained cytokine secretion seen in vivo from the extracellular matrix (ECM), we encapsulated a cargo protein into insect virus-derived proteins to form nanoparticle co-crystals and studied the release of this cargo protein mediated by matrix metalloproteinase-2 (MMP-2) and MMP-8. Specifically, when nerve growth factor (NGF), a neurotrophin, was encapsulated into nanoparticles, its release was promoted by MMPs secreted by a PC12 neuronal cell line. When these NGF nanoparticles were spotted onto a cover slip to create a uniform circular field, movement and alignment of PC12 cells via their extended axons along the periphery of the NGF nanoparticle field was observed. Neural cell differentiation was confirmed by the expression of specific markers of tau, neurofilament, and GAP-43. Connections between the extended axons and the growth cones were also observed, and expression of connexin 43 was consistent with the formation of gap junctions. Extensions and connection of very fine filopodia occurred between growth cones. Our studies indicate that crystalline protein nanoparticles can be utilized to generate a highly stable cytokine gradient microenvironment that regulates the alignment and differentiation of nerve cells. This technique greatly simplifies the creation of protein concentration gradients and may lead to therapies for neuronal injuries and disease.
Viability of Neural Cells on 3D Printed Graphene Bioelectronics
Authors: Guo Jingshuai , Niaraki Asli Amir Ehsan , Williams Kelli R. , Lai Pei Lun , Wang Xinwei , Montazami Reza , Hashemi Nicole N.
Published: September 2019

Parkinson’s disease (PD) is the second most common neurodegenerative disease in the United States after Alzheimer’s disease (AD). To help understand the electrophysiology of these diseases, N27 neuronal cells have been used as an in vitro model. In this study, a flexible graphene-based biosensor design is presented. Biocompatible graphene was manufactured using a liquid-phase exfoliation method and bovine serum albumin (BSA) for further exfoliation. Raman spectroscopy results indicated that the graphene produced was indeed few-layer graphene (FLG) with ( I D / I G ) G r a p h e n e = 0.11. Inkjet printing of this few-layer graphene ink onto Kapton polyimide (PI) followed by characterization via scanning electron microscopy (SEM) showed an average width of ≈868 µm with a normal thickness of ≈5.20 µm. Neuronal cells were placed on a thermally annealed 3D printed graphene chip. A live–dead cell assay was performed to prove the biosensor biocompatibility. A cell viability of approximately 80% was observed over 96 h, which indicates that annealed graphene on Kapton PI substrate could be used as a neuronal cell biosensor. This research will help us move forward with the study of N27 cell electrophysiology and electrical signaling.
The Effect of Different Rejection Letters on Applicants’ Reactions
Authors: Cortini Michela , Galanti Teresa , Barattucci Massimiliano
Published: September 2019

Organisations appear to pay little attention to rejection letters, considered a special form of organisational communication, despite a growing body of literature that shows they play an important role in terms of employer branding. This study aims to empirically test how applicants’ perceptions are affected by differently manipulated rejection letters. In detail, a sample of 138 rejected candidates filled in an ad hoc questionnaire on perceived selection procedure fairness and satisfaction, after receiving a rejection letter where we had manipulated time latency, the politeness formula and customisation. Results suggest that providing a timely, customised and informal notification is something agreeable, which is able to affect, above all, fairness perceptions and intention to re-apply. In detail, the time latency in giving feedback appears to affect the relationship between fairness perception and organisational recommendation and acts more as a mediator rather than an antecedent variable. Considering that providing feedback is a relatively low-cost activity that at the same time has a big impact on job applicants, our results show that organisations should be sensitive to negative feedback communication, especially in relation to response time, in order to support their employer branding.
Influence of the Brønsted Acidity on the Ring Opening of Decalin for Pt-USY Catalysts
Authors: Oliveira Soares Lech Walesa , Castellã Pergher Sibele Berenice
Published: September 2019

A challenging hot topic faced by the oil refinery industry is the upgrading of low-quality distillate fractions, such as light cycle oil (LCO), in order to meet current quality standards for diesel fuels. An auspicious technological alternative entails the complete saturation of the aromatic structures followed by the selective cleavage of endocyclic carbon-carbon bonds in the formed naphthenic rings (selective ring opening—SRO). This work reports the influence of Brønsted acid sites of platinum-ultra stable Y zeolite (Pt-USY) catalysts in the SRO of decalin as a model naphthenic feed. A maximum combined yield to selective ring opening products (ROP: C10-alkylcycloalkanes + OCD: C10-alkanes) as high as 28.6 wt% was achieved for 1.6Pt-NaUSY-im catalyst. The molar carbon distribution curve of the hydrocracked (C9-) products varied from M-shaped for 1.4Pt-USY-im catalyst, indicating mainly C–C bond cleavage of the ring opening products with one remaining naphthenic ring via carbocations and the paring reaction, to not M-shaped for the 1.6Pt-NaUSY-im catalyst, where carbon-carbon bond cleavage occurs preferentially through a hydrogenolysis mechanism on metal sites. High (hydro)thermal stability and secondary mesoporosity of the 1.6Pt-NaUSY-im catalysts make this system highly prospective for upgrading low-quality real distillate feeds.
Spatio-Radio Resource Management and Hybrid Beamforming for Limited Feedback Massive MIMO Systems
Authors: Khammari Hedi , Ahmed Irfan , Bhatti Ghulam , Alajmi Masoud
Published: September 2019

In this paper, a joint spatio–radio frequency resource allocation and hybrid beamforming scheme for the massive multiple-input multiple-output (MIMO) systems is proposed. We consider limited feedback two-stage hybrid beamformimg for decomposing the precoding matrix at the base-station. To reduce the channel state information (CSI) feedback of massive MIMO, we utilize the channel covariance-based RF precoding and beam selection. This beam selection process minimizes the inter-group interference. The regularized block diagonalization can mitigate the inter-group interference, but requires substantial overhead feedback. We use channel covariance-based eigenmodes and discrete Fourier transforms (DFT) to reduce the feedback overhead and design a simplified analog precoder. The columns of the analog beamforming matrix are selected based on the users’ grouping performed by the K-mean unsupervised machine learning algorithm. The digital precoder is designed with joint optimization of intra-group user utility function. It has been shown that more than 50 % feedback overhead is reduced by the eigenmodes-based analog precoder design. The joint beams, users scheduling and limited feedbacK-based hybrid precoding increases the sum-rate by 27.6 % compared to the sum-rate of one-group case, and reduce the feedback overhead by 62.5 % compared to the full CSI feedback.
A Radio over Fiber System with Simultaneous Wireless Multi-Mode Operation Based on a Multi-Wavelength Optical Comb and Pulse-Shaped 4QAM-OFDM
Authors: Li Guang , Lin Zhihua , Huang Xuguang , Li Jianqing
Published: September 2019

In this paper, we propose a radio over fiber transmission system with simultaneous wireless multi-mode operation based on multi-wavelength optical comb and pulse shaping. This study is an initial attempt to accomplish simultaneous wireless multi-mode operation on a single optical carrier. A multi-wavelength optical comb with 13 flat optical wavelengths and space of 10 GHz is achieved by utilizing radio frequency (RF)-optics modulation and parameter configuration. The central station contains four adjacent optical wavelengths separated from the multi-wavelength optical comb by a wavelength division multiplexer, that one is modulated by 4QAM-OFDM signals with an up-converted carrier frequency of 5 GHz. The signals modulated with a single-sideband can be obtained by employing pulse shaping. The single-sideband optical signals are combined with the other three optical wavelengths and then transmitted over a standard single-mode fiber with a length of 50 km. In this arrangement, we can obtain several wireless carriers with frequencies of 5 GHz, 25 GHz, 45 GHz, and 65 GHz by direct detection. These wireless carriers are used for wireless transmission between the RF remote units and the mobile terminals. Additionally, in the radio frequency (RF) remote unit, we have three pure optical sources that can be utilized for the uplink transmission. With single channel and direct optoelectronic modulation, the optical and wireless communication with 10 Gbps can be accomplished in the whole process of system network transmission.
A Spiking Neural Network Based on the Model of VO2–Neuron
Authors: Belyaev Maksim , Velichko Andrei
Published: September 2019

In this paper, we present an electrical circuit of a leaky integrate-and-fire neuron with one VO2 switch, which models the properties of biological neurons. Based on VO2 neurons, a two-layer spiking neural network consisting of nine input and three output neurons is modeled in the SPICE simulator. The network contains excitatory and inhibitory couplings, and implements the winner-takes-all principle in pattern recognition. Using a supervised Spike-Timing-Dependent Plasticity training method and a timing method of information coding, the network was trained to recognize three patterns with dimensions of 3 × 3 pixels. The neural network is able to recognize up to 105 images per second, and has the potential to increase the recognition speed further.
Towards Location Independent Gesture Recognition with Commodity WiFi Devices
Authors: Lu Yong , Lv Shaohe , Wang Xiaodong
Published: September 2019

Recently, WiFi-based gesture recognition has attracted increasing attention. Due to the sensitivity of WiFi signals to environments, an activity recognition model trained at a specific place can hardly work well for other places. To tackle this challenge, we propose WiHand, a location independent gesture recognition system based on commodity WiFi devices. Leveraging the low rank and sparse decomposition, WiHand separates gesture signal from background information, thus making it resilient to location variation. Extensive evaluations showed that WiHand can achieve an average accuracy of 93% for various locations. In addition, WiHand works well under through the wall scenario.
Analysis of the Flow Distribution in a Particle Bed Reactor for Nuclear Thermal Propulsion
Authors: Ji Yu , Liu Ziping , Sun Jun , Shi Lei
Published: September 2019

Nuclear thermal propulsion (NTP) is regarded as the preferred option for the upcoming crewed interstellar exploration due to its excellent performance compared to the current most advanced chemical propulsion systems. Over the past several decades, many novel concepts have been proposed, among which the particle bed reactor (PBR) is the most efficient, compact, and lightweight method. Its unique features, such as the extremely high power density and the radial flow path of coolant in the fuel region, introduce many challengeable issues to the thermal hydraulic design of PBR, with the flow distribution being representative. In this work, the flow distribution process within the core is analyzed based on the understanding of the axial pressure profile in a dummy PBR. A “flow shift” phenomenon leading to the hot spot in the core is introduced first, and three methods, i.e., decreasing the pressure drop within the hot gas channel, increasing the flow resistance on the cold frit or hot frit, and changing the flow pattern from “Z” to “U”, are proposed to reduce the “flow shift” and the consequent temperature mal-distribution. The pros and cons of using cold frit or hot frit to distribute the coolant are also discussed. Finally, by using three numerical examples, these analyses are demonstrated. The findings here may provide technical support for PBR design.
Thermal Management of High-Power Density Electric Motors for Electrification of Aviation and Beyond
Authors: Deisenroth David C. , Ohadi Michael
Published: September 2019

Enhanced cooling, coupled with novel designs and packaging of semiconductors, has revolutionized communications, computing, lighting, and electric power conversion. It is time for a similar revolution that will unleash the potential of electrified propulsion technologies to drive improvements in fuel-to-propulsion efficiency, emission reduction, and increased power and torque densities for aviation and beyond. High efficiency and high specific power (kW/kg) electric motors are a key enabler for future electrification of aviation. To improve cooling of emerging synchronous machines, and to realize performance and cost metrics of next-generation electric motors, electromagnetic and thermomechanical co-design can be enabled by innovative design topologies, materials, and manufacturing techniques. This paper focuses on the most recent progress in thermal management of electric motors with particular focus on electric motors of significance to aviation propulsion.
Optimal Control of Microgrid Operation Based on Fuzzy Sliding Mode Droop Control
Authors: Zhu Yangyan , Wang Zhijie , Liu Yonghui , Wang Hong , Tai Nengling , Jiang Xiuchen
Published: September 2019

In the application of microgrid systems that include wind power, photovoltaic systems, diesel generators, and battery storage, the cooperative control and optimisation of power distribution between power sources is a major issue. Recently, the droop control has been used widely in microgrids. However, droop control relies mainly on the line parameter model between the grid and the load. Therefore, to improve the performance of the microgrid, the optimal control of microgrid operation based on the fuzzy sliding mode droop control method is considered in this paper. To begin, system parameters were obtained by modeling droop control with self-learning fuzzy control strategy. Then, to improve the accuracy of the power distribution in the multi-micro source system, the nonlinear differential smoothing control method was employed. Finally, by comparing the self-learning fuzzy sliding mode control based on drooping strategy and the traditional droop control method, it was demonstrated that the method proposed can effectively reduce the fluctuation of the bus voltage and improve the output voltage quality of the microgrid system.