bluuebunny/crossref_metadata_2025 huggingface dataset:
Dysphagia in supratentorial recent small subcortical infarcts results from bilateral pyramidal tract damage
Authors: Fandler Simon , Gattringer Thomas , Pinter Daniela , Pirpamer Lukas , Borsodi Florian , Eppinger Sebastian , Niederkorn Kurt , Enzinger Christian , Fazekas Franz
Published: May 2018

Background

Dysphagia occurs in up to 20% of patients with a recent small subcortical infarct, even when excluding brainstem infarcts.

Aim

To examine the impact of lesion topography and concomitant cerebrovascular lesions on the occurrence of dysphagia in patients with a single supratentorial recent small subcortical infarct.

Methods

We retrospectively identified all inpatients with magnetic resonance imaging-confirmed supratentorial recent small subcortical infarcts over a five-year period. Dysphagia was determined by speech-language therapists. Recent small subcortical infarcts were compiled into a standard brain model and compared using lesion probability maps. Furthermore, magnetic resonance imaging scans were reviewed for the combination of both acute and old cerebrovascular lesions.

Results

A total of 243 patients with a recent small subcortical infarct were identified (mean age 67.9 ± 12.2 years). Of those, 29 had mild and 18 moderate-to-severe dysphagia. Lesion probability maps suggested no recent small subcortical infarct location favoring the occurrence of moderate-to-severe dysphagia. However, patients with moderate-to-severe dysphagia more frequently showed combined damage to both pyramidal tracts by the recent small subcortical infarct and a contralateral old lesion (lacune: 77.8% vs. 19.9%, p < 0.001; lacune or confluent white matter hyperintensities: 100% vs. 57.7%, p < 0.001) than patients without swallowing dysfunction. Comparable results were obtained when analyzing patients with any degree of dysphagia.

Conclusions

Preexisting contralateral vascular pyramidal tract lesions are closely related to the occurrence of moderate-to-severe dysphagia in patients with supratentorial recent small subcortical infarcts.
Reference values of left heart echocardiographic dimensions and mass in male peri-pubertal athletes
Authors: Cavarretta Elena , Maffessanti Francesco , Sperandii Fabio , Guerra Emanuele , Quaranta Federico , Nigro Antonia , Minati Monia , Rebecchi Marco , Fossati Chiara , Calò Leonardo , Pigozzi Fabio
Published: May 2018

Background

Several articles have proposed reference values in healthy paediatric subjects, but none of them has evaluated a large population of healthy trained adolescents.

Design

The study purpose was to establish normal echocardiographic measurements of left heart (aortic root, left atrium and left ventricular dimensions and mass) in relation to age, weight, height, body mass index, body surface area and training hours in this specific population.

Methods

We retrospectively evaluated 2151 consecutive, healthy, peri-pubertal athletes (100% male, mean age 12.4 ± 1.4 years, range 8–18) referred to a single centre for pre-participation screening. All participants were young soccer athletes who trained for a mean of 7.2 ± 1.1 h per week.

Results

Left ventricular internal diameters, wall thickness, left ventricular mass, aortic root and left atrium diameters were significantly correlated to age, body surface area, height and weight ( p < 0.01). Age, height, weight and body surface area were found associated with chamber size, while body mass index and training hours were not. Inclusion of both age and body size parameters in the statistical models resulted in improved overall explained variance for diameters and left ventricular mass.

Conclusion

Equations, mean values and percentile charts for the different age groups may be useful as reference data in efficiently assessing left ventricular parameters in young athletes.
Discursive Deflection: Accusation of “Fake News” and the Spread of Mis- and Disinformation in the Tweets of President Trump
Authors: Ross Andrew S. , Rivers Damian J.
Published: May 2018

Twitter is increasingly being used within the sociopolitical domain as a channel through which to circulate information and opinions. Throughout the 2016 US Presidential primaries and general election campaign, a notable feature was the prolific Twitter use of Republican candidate and then nominee, Donald Trump. This use has continued since his election victory and inauguration as President. Trump’s use of Twitter has drawn criticism due to his rhetoric in relation to various issues, including Hillary Clinton, the size of the crowd in attendance at his inauguration, the policies of the former Obama administration, and immigration and foreign policy. One of the most notable features of Trump’s Twitter use has been his repeated ridicule of the mainstream media through pejorative labels such as “fake news” and “fake media.” These labels have been deployed in an attempt to deter the public from trusting media reports, many of which are critical of Trump’s presidency, and to position himself as the only reliable source of truth. However, given the contestable nature of objective truth, it can be argued that Trump himself is a serial offender in the propagation of mis- and disinformation in the same vein that he accuses the media. This article adopts a corpus analysis of Trump’s Twitter discourse to highlight his accusations of fake news and how he operates as a serial spreader of mis- and disinformation. Our data show that Trump uses these accusations to demonstrate allegiance and as a cover for his own spreading of mis- and disinformation that is framed as truth.
Unraveling Entrepreneurial Team Formation: A Qualitative Study Among Funded Ventures
Authors: Klada Triantafyllia-Varvara
Published: May 2018

Arguably, entrepreneurial team formation constitutes an arduous but fundamental task toward venture establishment. Given the relatively scant attention that has been paid to this research topic, this study focuses on founders’ behaviors in their attempt to narrow the gap between their own skills and the ones required for the materialization of their vision. Semistructured interviews with 14 key members of externally funded entrepreneurial teams in Greece suggested that entrepreneurs themselves account for the lack of legitimacy, knowledge, and financial resources through leveraging their social networks, available information resources, and certain cooperation agreements as well as selecting candidates whose profile is aligned with entrepreneurial challenges and goals. Moreover, they revealed that as these challenges are mitigated, they give rise to a wider spectrum of choices with regard to the team formation process; this evolutionary path seems to be facilitated by certain events, which act as triggers of change. These associations are incorporated in a framework which depicts founders’ behaviors and their temporal variations in the context of entrepreneurial team formation.
The Role of Vitamin B12 in the Management and Optimization of Treatment in Patients With Degenerative Cervical Myelopathy
Authors: Nouri Aria , Patel Kishan , Montejo Julio , Nasser Rani , Gimbel David A. , Sciubba Daniel M. , Cheng Joseph S.
Published: May 2018

Study Design:

Narrative review.

Objectives:

To discuss the relationship between degenerative cervical myelopathy (DCM) and vitamin B12 deficiency. Specifically, it is the aim to outline the rational for future research into assessment and therapeutic optimization of vitamin B12 in the treatment of DCM.

Methods:

Literature review.

Results:

DCM is the commonest cause of spinal cord impairment, with an average age of presentation in the sixth decade. Patients at this age have also been reported to have a high prevalence of vitamin B12 deficiency, with estimates of up to 20% in the elderly. Vitamin B12 deficiency can result in subacute combined degeneration of the spinal cord (SACD), and several case reports have pointed to patients with both DCM and SACD. Both SACD and reversible compressive injury due to DCM necessitate remyelination in the spinal cord, a process that requires adequate vitamin B12 levels. Basic science research on nerve crush injuries have shown that vitamin B12 levels are altered after nerve injury and that vitamin B12 along with dexamethasone or nonsteroidal anti-inflammatory drugs can reduce Wallerian degeneration. Furthermore, it has been suggested that a combination of B-vitamins can reduce glutamate-induced neurotoxicity.

Conclusions:

Given the high prevalence of clinical and subclinical vitamin B12 deficiency in the elderly, the role of vitamin B12 in myelination, and vitamin B12 deficiency as a differential diagnosis of DCM, it is important to investigate what role vitamin B12 levels play in patients with DCM in terms of baseline neurological function and whether optimization of vitamin B12 levels can improve surgical outcome. Furthermore, the routine assessment of vitamin B12 levels in patients considered for DCM surgery should be considered.
Developmental vascular regression is regulated by a Wnt/β-catenin, MYC, P21 (CDKN1A) pathway that controls cell proliferation and cell death
Authors: Nayak Gowri , Odaka Yoshinobu , Prasad Vikram , Solano Alyssa F. , Yeo Eun-Jin , Vemaraju Shruti , Molkentin Jeffery D. , Trumpp Andreas , Williams Bart , Rao Sujata , Lang Richard A.
Published: May 2018

Normal development requires tight regulation of cell proliferation and cell death. Here, we investigated these control mechanisms in the hyaloid vessels, a temporary vascular network in the mammalian eye that requires a Wnt/β-catenin response for scheduled regression. We investigated whether the hyaloid Wnt response was linked to the oncogene Myc, and the cyclin-dependent kinase inhibitor P21 (CDKN1A), both established regulators of cell cycle progression and cell death. Our analysis showed that the Wnt pathway coreceptors LRP5 and LRP6 have overlapping activities mediating the Wnt/β-catenin signaling in hyaloid vascular endothelial cells (VECs). We also showed that both Myc and Cdkn1a are downstream of the Wnt response and are required for hyaloid regression but for different reasons. Conditional deletion of Myc in VECs suppressed both proliferation and cell death. By contrast, conditional deletion of Cdkn1a resulted in VEC over-proliferation that countered the effects of cell death on regression. When combined with analysis of MYC, and P21 protein levels, this analysis suggests that a Wnt/β-catenin, MYC-P21 pathway regulates scheduled hyaloid vessel regression.
A guide to using functional magnetic resonance imaging to study Alzheimer's disease in animal models
Authors: Asaad Mazen , Lee Jin Hyung
Published: May 2018

Alzheimer's disease is a leading healthcare challenge facing our society today. Functional magnetic resonance imaging (fMRI) of the brain has played an important role in our efforts to understand how Alzheimer's disease alters brain function. Using fMRI in animal models of Alzheimer's disease has the potential to provide us with a more comprehensive understanding of the observations made in human clinical fMRI studies. However, using fMRI in animal models of Alzheimer's disease presents some unique challenges. Here, we highlight some of these challenges and discuss potential solutions for researchers interested in performing fMRI in animal models. First, we briefly summarize our current understanding of Alzheimer's disease from a mechanistic standpoint. We then overview the wide array of animal models available for studying this disease and how to choose the most appropriate model to study, depending on which aspects of the condition researchers seek to investigate. Finally, we discuss the contributions of fMRI to our understanding of Alzheimer's disease and the issues to consider when designing fMRI studies for animal models, such as differences in brain activity based on anesthetic choice and ways to interrogate more specific questions in rodents beyond those that can be addressed in humans. The goal of this article is to provide information on the utility of fMRI, and approaches to consider when using fMRI, for studies of Alzheimer's disease in animal models.
Kinematic control of male Allen's Hummingbird wing trill over a range of flight speeds
Authors: Clark Christopher J. , Mistick Emily A.
Published: May 2018

Wing trills are pulsed sounds produced by modified wing feathers at one or more specific points in time during a wingbeat. Male Allen's Hummingbird (Selasphorus sasin) produce a sexually dimorphic 9 kHz wing trill in flight. Here we investigate the kinematic basis for trill production. The wingtip velocity hypothesis posits that trill production is modulated by the airspeed of the wingtip at some point during the wingbeat, whereas the wing rotation hypothesis posits that trill production is instead modulated by wing rotation kinematics. To test these hypotheses, we flew six male Allen's Hummingbirds in an open jet wind tunnel at flight speeds of 0, 3, 6, 9, 12 and 14 m s−1, and recorded their flight with two 'acoustic cameras' placed below and behind, or below and lateral to the flying bird. The acoustic cameras are phased arrays of 40 microphones that used beamforming to spatially locate sound sources within a camera image. Trill Sound Pressure Level (SPL) exhibited a U-shaped relationship with flight speed in all three camera positions. SPL was greatest perpendicular to the stroke plane. Acoustic camera videos suggest that the trill is produced during supination. The trill was up to 20 dB louder during maneuvers than it was during steady state flight in the wind tunnel, across all airspeeds tested. These data provide partial support for the wing rotation hypothesis. Altered wing rotation kinematics could allow male Allen's Hummingbird to modulate trill production in social contexts such as courtship displays.
Association of adverse childhood experiences with functional identity and impulsivity among adults: a cross-sectional study
Authors: Haaris Sheikh Muhammad , Naveed Sadiq , Waqas Ahmed , Tahir Jaura Ihtisham
Published: May 2018

Introduction: The present study explores the association of adverse childhood experiences with impulsivity and functional identity among Pakistani adults.

Methods: In this cross-sectional study, 260 Pakistani medical students aged 18 and above were approached. A consent form, a questionnaire on sociodemographic characteristics, and an English versions of the Adverse Childhood Experiences (ACE) scale, Functions of Identity scale (FIS) and Barratt’s Impulsiveness Scale (BIS-11) was employed in this study. All data were analyzed in SPSS v. 20.

Results: A total of 122 (52.6%) of respondents had experienced at least one adverse childhood experience. Verbal, physical, sexual adverse events and poor support and affection from family were the most reported adverse events. ACE scores yielded a significantly positive association with cognitive stability, perseverance and motor impulsivity on the Barrat’s impulsivity scale. Whereas, it yielded negative association with structure and harmony subscales of the functional identity as well as cognitive complexity subscale of the impulsivity scale.

Conclusions: A high proportion of Pakistani medical students reported adverse childhood experiences, which lead to impulsive behaviors and poor functional identities.
Incidence and risk factors for complications after definitive skeletal fixation of lower extremity in multiple injury patients: a retrospective chart review
Authors: Sangkomkamhang Thananit , Thinkhamrop Wilaiphorn , Thinkhamrop Bandit , Laohasiriwong Wongsa
Published: May 2018

Background: The management of multiple injuries is complex. Type and timing of treatment for lower extremity fractures is a controversial subject. Although many studies have demonstrated the safety and effectiveness of early treatment, others have suggested that early definitive stabilization may cause complications, especially with chest and head injuries. The aim of this study was to determine the complications and effects of timing of fixation, and investigate risk factors for complications in multiple injuries patients with lower extremity fractures.

Methods: A Retrospective chart review from Khon Kaen Trauma Registry between 2008 and 2015 were collected. All major complications were identified and collected for example acute respiratory distress syndrome (ARDS), acute kidney injury (AKI) and sepsis.  The time to definitive skeletal fixation from initial injury was identified and analyzed with multiple logistic regression.

Results: 1224 multiple injuries patients with lower extremity fractures were identified. The mean age was 34±19.5 years, 74.4% were male and 25.6% female. The mean time from initial injury to definitive operation was 55.7±53.9 hours. Complications occurred with 178 patients (14.5%), the most common of which were pneumonia, ARDS and AKI. After adjusting for sex, severity of injury, we found that the operation within 24-48 hours complication was 6.67 times less common than in the early treatment group (less than 24 hours) (95% CI: 3.03 to 10.00, P-value< 0.001).

Conclusions: About 15% of the multiple injuries patients with lower extremity fracture had major complications. The optimal time for definitive fixation in lower extremity fractures to reduce complications was within 24-48 hours. We found that if we operated too early (before 24 hours) or more than 48 hours after the injury it could increase the morbidity and mortality.
Transit Line Structures in a General Parametric City: The Role of Heuristics
Authors: Fielbaum Andrés , Jara-Díaz Sergio , Gschwender Antonio
Published: May 2018

The merits of selected heuristics to obtain transit line structures are analyzed, applying them on a synthetic parametric description of a symmetric city that allows representation of different city types (mostly monocentric, polycentric, or dispersed) and varying number of trips. Predetermined basic strategic designs are used as references for comparison considering operators and users costs. We show that (a) line structures that emerge from heuristics dominate the comparison for most types of cities; (b) these line structures are of the direct type; (c) the virtues of a heuristic depend on the level and, most importantly, the spatial structure of transport demand; and (d) new types of heuristics should take into account the structural characteristics of cities, allowing for potential non-direct-type solutions.

The online appendix is available at https://doi.org/10.1287/trsc.2018.0833 .
A Preliminary Discussion of the Polynomial Fits to the Thermal Curves of Solid-Solid Reactions, Carried Out in Bulk
Authors: Ahmad Rabia , Faisal Qamer
Published: May 2018

Dozens of authors have obtained experimental thermal curves of solid-solid reactions, carried out in bulk. Different mathematical functions were used to obtain fits to the thermal curve data. Polynomials were found to give the best fits to the data. The data may be divided into three types on the basis of the shape of the curves, with one peak, with two peaks and with three peaks. In this preliminary report we present one fitted curve of each of the three types as specimen. The importance of the Thermal Curves is briefly pointed out. A detailed discussion of the large amount of the available data may be taken up later.
Syntheses and Thermal Characterisation of Mixed (Sm-Y) Oxalates Prepared by Coprecipitation Method
Authors: Pauri Presenjit , Ghoshal S. K. , Tewari H. S.
Published: May 2018

In this work, mixed (Sm1-xYx)2[C2O4]3.nH2O with x= 0.50 and 0.70 were prepared using standardized co precipitation method. All the synthesized oxalates were characterized by x-ray diffraction and differential scanning calorimeter. All the samples are homogeneous in stoichiometry. The XRD analysis of these synthesized samples reveals that a solid solution forms for these two compositions The thermal decomposition of the mixed oxalates is complex although completed a lower temperatures. This is an important result for the preparation of Sm-Y mixed oxides, because all the properties of the mixed oxides are intrinsic and depend only on their composition and thermal treatment schedules.
Exhibition Review
Authors: Dalal Radha
Published: May 2018

Imperial Threads: Motifs and Artisans from Turkey, Iran, and India, Museum of Islamic Art, Doha, Qatar, March 14, 2017–January 27, 2018
Précis
Authors: Ünlüönen Selin , Tabbal Sarah
Published: May 2018

Writing/Curating the Middle East, Yale University, New Haven, CT, United States, March 30–31, 2017

The Artistic Heritage of al-Andalus and National Identity, Humboldt University, Berlin, Germany, October 27–29, 2017
The privatization of street art and the preservation paradox
Authors: Davis Lindsey
Published: May 2018

Impactful online and hyped in the media, street art remains an art world enigma: It’s commercial success is celebrated but its public iterations still exist somewhere between public art and vandalism. This article presents the street artist’s practice as a two-part enterprise, comprised of commercial works created for resale and public works intended as gifts to the public. Interdependent and inextricably linked, both elements exist as two sides of the same practice in a strategy informed by the success of twentieth-century street artists such as Keith Haring and Jean-Michel Basquiat. Conceptually centred around authentication, a street artist’s dual practice discourages the sale of public works by declaring them inauthentic post-removal, complicating their ability to be preserved for the very public for which they are originally intended. This article examines the consequences of this dual practice, focusing specifically on the paradoxical position of removed public works and the systems which enable their legal sales without the artist’s involvement. The article concludes with an argument advocating for the preservation of public works, in order to facilitate a comprehensive understanding of the street artist’s practice.
Review
Authors: McCleary Badir
Published: May 2018

Art Basel, Miami Beach, Miami, Florida, 7–10 December 2017
The abstraction of content and intent between murals and street art
Authors: Fuentes Edward
Published: May 2018

This article surveys the aesthetic differences between murals that are a visual response to community identity and temporary large-scale works shaped by the Western canon of underground urban graffiti. To theorize the production of urban art by reading its history and the intent of artists introduces new scholarly inquiry of the shared and conflicting messages of a popular form of public art.
Dissimulacro-ressimulação: ensejos da cultura do ódio na era do Brasil pós-verdade
Authors: Quadros Paulo
Published: May 2018

Este trabalho objetiva realizar uma reflexão apurada sobre o fenômeno cultural da pós-verdade, sob o viés de interlocutores brasileiros. Os neologismos dissimulacro e ressimulação são uma tentativa autoral de dar outra conotação simbólica a esse fenômeno, que poderia ser nomeado e significado por outras designações históricas ou contemporâneas, que concebam seus elementos como algo que sempre existiu no campo da manipulação política e ideológica, desde que o homem disputa o poder, a partir de artimanhas, conchavos, alianças, que sinalizam modos de manter ou verter a autoridade sobre o exercício do poder. No âmbito dessa discussão, são levantados alguns aspectos conceituais contraditórios da pós-verdade, alguns pressupostos do que é dissimulacro e ressimulação, a pós-verdade como fabricação aurática de signos, a fenomenologia das notícias falsas com seus objetivos maquiavélicos, o alcance da cultura do ódio nas redes sociais, o mito da dissolução e insolvência do outro no campo de tensão entre o reconhecimento e não reconhecimento da alteridade radical, a pós-verdade como ideologia da razão apática no contexto das redes sociais, e a reconstrução simbólica do signo das relações humanas na contemporaneidade. Para o aprofundamento de questões, são empregados como referencial teórico os seguintes autores: Cremilda Medina, Maria Teresa Cruz, Luiz Carlos Restrepo, Gabriel Priollo, Jean Baudrillard, Gilles Deleuze, Carlos Skliar, Peter Sloterdijk, entre outros. O objetivo da escolha de tais autores é inventariar ideias, valores, conceitos e visões que ao mesmo tempo ajudem a compreender o fenômeno comunicacional de propagação das “falsas verdades”, assim como sinalizem atitudes de enfrentamento a essa questão profundamente preocupante.
Fracture tooth reattachment
Authors: Hassan Ahmed
Published: May 2018

Anterior teeth fractures occur daily, with the main patient demand to restore esthetically the resultant defect.Â  There is nothing more esthetic than the tooth itself.Â  Many techniques were described to use the fractured piece to restore this defect in case of accurate fit.Â  The objective of this article is to summarize these techniques to give the dental practitioners the opportunity to restore the fractured tooth more conservatively and in the same time more esthetically.Â  Also it throws light on the prevalence and etiology of tooth fracture.Â Frontal teeth are subjected to traumas more than other teeth in the mouth.Â  These traumas may lead to tooth fracture with or without pulp involvement.Â  In attempts to restore the fractured tooth in more esthetic and conservative manner, the fractured piece may be used as a restorative material. This treatment modality has gained increased popularity among dental practitioner due to the continuous development in the adhesive field.Â  Several techniques were used.Â  These techniques include, simple reattachment, external chamfer, over contouring, internal dentin bevel, and internal enamel bevel.Â  All these techniques try to afford the highest fracture resistance accompanied with the least possible tooth preparation.Â  Combination of two or more technique would result in better performance.Keywords:Bevel, bonding, reattachment, tooth fracture.
Isolasi, Identifikasi dan Uji Aktivitas Senyawa Triterpenoid Rimpang Bengle (Zingiber cassumunar Roxb.) sebagai Antibakteri
Authors: Rosyid Afrezza Lukman , Fachriyah Enny , Kusrini Dewi
Published: May 2018

Penelitian mengenai isolasi, identifikasi dan uji aktivitas senyawa triterpenoid rimpang bengle (Zingiber cassumunar Roxb) sebagai antibakteri telah dilakukan. Penelitian ini bertujuan untuk mendapatkan senyawa golongan triterpenoid dari rimpang bengle serta mengetahui aktivitasnya terhadap bakteri E.coli dan S.aureus. Tahapan penelitian ini meliputi ekstraksi menggunakan etanol 96% dan kemudian dipartisi dengan n-heksana. Ekstrak n-heksana yang telah dipekatkan kemudian dilakukan kromatografi kolom. Identifikasi fraksi kolom yang positif mengandung triterpenoid dilakukan dengan menggunakan pereaksi Liebermann-Burchard. Fraksi positif triterpenoid selanjutnya dipisahkan melalui metode kromatografi preparatif. Isolat yang didapat selanjutnya diuji kemurnian menggunakan metode KLT berbagai eluen dan KLT dua dimensi. Isolat juga dianalisis menggunakan FT-IR dan KG-SM. Hasil analisis FT-IR menunjukkan isolat memiliki vibrasi pada bilangan gelombang 2924 cm-1 yang merupakan vibrasi ulur C-H asimetri, 2862 cm-1 vibrasi ulur C-H simetri, 1720 cm-1 vibrasi ulur C=O, 1465 cm-1 vibrasi tekuk C-H dari CH2, 1395 cm-1 adalah vibrasi gugus gem-dimetil. Hasil analisis KG-SM menunjukkan isolat memiliki waktu retensi 24,5 menit, bobot molekul 426, dengan puncak dasar m/z 69. Berdasarkan database isolat merupakan senyawa friedelen-3-o.
Telaah Surfaktan untuk Proses Enhanced Oil Recovery (EOR) dan Profil Adsorpsi Surfaktan A-Olefin Sulfonates (AOS)
Authors: Juita Rohayati , Arnelli Arnelli , Yusniati Yusniati
Published: May 2018

Telaah surfaktan untuk proses enhanced oil recovery (EOR) dan profil adsorpsi surfaktan a-Olefin Sulfonates (AOS) telah dilakukan. Penelitian ini bertujuan untuk mengetahui jenis surfaktan yang dapat digunakan untuk proses enhanced oil recovery (EOR) dan mengetahui profil adsorpsi surfaktan. Penelitian ini terbagi 2 tahap, yaitu tahap pertama adalah screening surfaktan, tahap kedua adalah adsorpsi surfaktan dalam batuan sandstone dan limestone. Screening surfaktan yang dilakukan, meliputi: uji pelarutan di mana surfaktan dilarutkan dalam akuades. Uji compatibility di mana surfaktan dilarutkan dalam air dan formasinya diamati selama 3 hari. Uji thermal stability di mana surfaktan yang lolos compatibility dipanaskan 80°C selama 8 minggu. Adsorpsi surfaktan dilakukan di dalam batuan sandstone (batu pasir silika), pasir bangka, pasir malang dan limestone (batu kapur). Batuan direndam selama 168 jam dalam larutan surfaktan S24 (a-Olefin Sulfonates) 0,6%; 1,2%; 1,8%, disaring kemudian disentrifuge dan diukur absorbansinya dengan spektroskopi UV-Vis. Surfaktan AOS 0,6% dalam batu pasir silika dan surfaktan AOS 1,8% dalam pasir malang tidak teradsorpsi, sehingga cocok untuk proses enhanced oil recovery (EOR).
Modifikasi Zeolit Alam Menggunakan TiO2 sebagai Fotokatalis Zat Pewarna Indigo Carmine
Authors: Ansori Sofian , Sriatun Sriatun , Pardoyo Pardoyo
Published: May 2018

Modifikasi zeolit alam menggunakan TiO2 sebagai fotokatalis zat pewarna indigo carmine telah dilakukan. Tujuan penelitian ini untuk memodifikasi permukaan zeolit alam dengan TiO2 dan menggunakannya sebagai fotokatalis, menentukan pH optimum untuk degradasi senyawa pewarna indigo carmine, dan mengetahui pengaruh waktu degradasi indigo carmine. Zeolit alam diaktifasi dan kemudian dibuat menjadi zeolit-H. Zeolit-H kemudian direaksikan dengan TiCl4 dilanjutkan dengan kalsinasi pada suhu 450°C sehingga terbentuk zeolit-TiO2. Zeolit-TiO2 ini selanjutnya digunakan untuk mendegradasi indigo carmine dengan variasi waktu dan pH larutan. Hasil XRD menunjukkan bahwa terbentuk TiO2 pada zeolit yang ditunjukkan dengan nilai 2θ 17,42°; 24,99°; dan 29,96°. Hasil FTIR menunjukkan adanya bilangan gelombang pada 316,3 cm-1 yang mengindikasikan adanya TiO2 pada permukaan zeolit. Hasil degradasi indigo carmine menunjukkan bahwa semakin lama waktu degradasi semakin banyak indigo carmine yang terdegradasi oleh zeolit-TiO2 dan semakin asam pH indigo carmine semakin besar degradasinya.
Dealuminasi Zeolit Alam Menggunakan Asam (HCl dan H2SO4) untuk Katalis pada Proses Sintesis Biodiesel
Authors: Norvia Sugiarti , Suhartana Suhartana , Pardoyo Pardoyo
Published: May 2018

Telah dilakukan dealuminasi zeolit alam menggunakan asam (HCl dan H2SO4) untuk katalis pada proses sintesis biodiesel. Zeolit dianalisis dengan AAS dan FTIR serta uji aktivitas katalis pada sintesis biodiesel dengan metode GC-MS. Didapatkan bahwa H2SO4 lebih efektif mendealuminasi zeolite dibandingkan dengan HCl. Hasil spektrogram FTIR menunjukkan bahwa proses dealuminasi asam mengakibatkan perubahan bilangan gelombang dan rasio Si/Al yang cukup signifikan, di mana pada rasio Si/Al zeolit meningkat dari 4,57 menjadi 5,41 pada zeolit alam dealuminasi HCl dan menjadi 6,42 pada zeolit alam dealuminasi H2SO4. Zeolit terdealuminasi mampu bekerja sebagai katalis dalam sintesis biodiesel di mana katalis zeolit dealuminasi H2SO4 menghasilkan metil ester dengan senyawa dominan asam 9-oktadekenoat dengan persentase luas area sebesar 63,21% lebih banyak dibandingkan pada katalis zeolit dealuminasi HCl dan zeolite belum didealuminasi.
Sintesis dan Karakterisasi Senyawa Kompleks Zn(II)-8-Hidroksikuinolin
Authors: Hermawati Eka Sulistya , Suhartana Suhartana , Taslimah Taslimah
Published: May 2018

Senyawa koordinasi adalah senyawa yang terbentuk karena adanya ikatan antara ligan dengan ion pusat. Penelitian ini dilakukan dengan tujuan memperoleh senyawa kompleks Zn(II)-8-Hidroksikuinolin dengan pelarut asetonitril, metanol dan etanol serta menentukan karakteristik dari produk yang diperoleh. Metode penelitian ini dilakukan dengan mencampurkan larutan ZnCl2 dan larutan 8-Hidroksikuinolin disertai pengadukan dengan menggunakan magnetik stirrer selama 60 menit. Karakterisasi uji dilakukan dengan menggunakan UV-Vis, FTIR dan AAS. Dari sintesis kompleks Zn(II)-8-Hidroksikuinolin dalam pelarut asetonitril, metanol dan etanol,  diperoleh rendemen  sebesar 73,07 % ; 63,46% ; dan 48,67%, dengan panjang gelombang maksimum berturut-turut sebesar 319,5 nm ; 313 nm ; and 320 nm. Adanya ikatan Zn-N teridentifikasi pada pita serapan pada kisaran 439,79 cm-1 hingga 513,09 cm-1, sedangkan ikatan Zn-O teridentifikasi pada pita serapan pada kisaran 542,98 cm-1 hingga 543,95 cm-1. Dapat disimpulkan bahwa Zn(II) terkoordinasi dengan ligan 8-Hidroksikuinolin membentuk endapan senyawa kompleks Zn(II)-8-Hidroksikuinolin berwarna kuning.
Pemanfaatan Montmorillonit Terpilar Al-Cr pada Adsorpsi Zat Warna Rhodamin B dengan Variasi Massa Adsorben dan Waktu Adsorpsi
Authors: Geraldina Geraldina , Taslimah Taslimah , Nuryanto Rahmad
Published: May 2018

Rhodamin B merupakan salah satu zat warna yang umumnya banyak digunakan pada proses industri tekstil di Indonesia dan menghasilkan limbah cair yang mencemari lingkungan. Bentonit alam adalah material berpori yang kelimpahannya cukup banyak di alam dan dapat menangani masalah limbah cair melalui proses adsorpsi. Namun kapasitas bentonite dalam mengadsorpsi terbatas sehingga diperlukan modifikasi agar kemampuan adsorpsinya meningkat. Proses aktivasi menggunakan asam klorida dan pilarisasi menggunakan pemilar Al dan Cr digunakan sebagai cara untuk memodifikasi bentonit, sehingga diharapkan menghasilkan luas permukaan yang lebih besar. Hasil GSA pada montmorillonit teraktivasi menunjukkan basal spacing sebesar 15,68 Å dan luas permukaan sebesar 75,312 m2/g. Pemilaran menghasilkan montmorillonit terpilar Al25Cr75 dengan basal spacing paling tinggi dan luas permukaan secara berturut-turut sebesar 16,55 Å dan 41,804 m2/g. Adsorpsi rhodamin B menggunakan montmorillonit terpilar Al25Cr75 menghasilkan efektivitas adsorpsi sebesar 99,85% dari konsentrasi rhodamin B sebesar 50 ppm dengan kondisi optimum massa adsorben sebesar 0,1 gram dan waktu adsorpsi selama 75 menit, yang dianalisis menggunakan spektrofotometri UV-Vis pada panjang gelombang 523 nm.
Aplikasi Steganografi Menggunakan LSB 4 Bit Sisipan dengan Kombinasi Algoritme Substitusi dan Vigenere Berbasis Android
Authors: Hernawandra Priyagung , Supriyadi Supriyadi , Lenggana U. Tresna
Published: May 2018

This study aims to implement steganography with 4 bit LSB method combined with Vigenere and substitution encryption algorithms. This combination strengthens the security of text messages that are inserted into the image because the message is already a ciphertext as the result of the Vigenere and substitution encryption process. This steganography is realized as an application that runs on Android devices. This application can insert text messages that contain space characters and a combination of uppercase letters in a digital image. Using this application, insertion of messages into images causes the increase of images size by an average of 12.77% of the original size from 10 sample images.
Socioeconomic Driving Forces of International Migration
Authors: Wesselbaum Dennis
Published: May 2018

This paper makes a contribution to the literature on the driving forces of international migration. In contrast to the existing literature we consider the effect of socioeconomic variables (population dynamics, education and health, and openness) on migration flows. Especially the effects of openness of a society have not received much attention in the scientific debate.We use a panel data set of bilateral migration flows between 16 destination and 198 origin countries over the time span from 1980 to 2015. Most importantly, we find that our socioeconomic variables significantly affect the migration decision. Including socioeconomic variables does affect the size of the effects of the commonly used variables in the literature.Further, we find robust evidence that the socioeconomic variables at hand have non-linear effects on migration. For example, we find that the effect of human capital on migration follows an inverted U-shaped pattern.
Concave Rectangle Photonic Crystal Ring Resonator for Ultra-Fast All-Optical Modulation
Authors: Rebhi Sana , Massoudi Radhouene , Najjar Monia
Published: May 2018

In this paper, an ultra-fast all-optical modulator, based on a new shape of nonlinear photonic crystal ring resonator, is designed and studied. Numerical methods such as plane wave expansion (PWE) and finite-difference time domain (FDTD) are used to perform simulations. The modulation technique consists of carrier light controlling by means of input light signal and Kerr effect. The investigation of extinction ratio and insertion loss within the carrier input power shows that the choice of 0.7 W is the optimal value of that power to ensure the tradeoff between both characteristics. The suggested modulator demonstrates an excellent extinction ratio about 20.8018, a very low insertion loss of −13.98 and a short switching time about 13.4 ps. According to the obtained results, the modulator can be considered as an ultra-fast and ultra-compact optical component.
Existence results of solutions for impulsive fractional differential equations
Authors: Gupta Vidushi , Dabas Jaydev , Fečkan Michal
Published: May 2018

We analyze the existence of solution for the neutral fractional integro-differential equation (FDE) of order in the interval (1, 2] with impulsive and integral boundary conditions (IBCs). The key approach for outcomes are based on the non-compactness measures and fixed point techniques.We obtain some sufficient conditions on the existence of solutions for the proposed system. Moreover, some applications are studies to demonstrate the proficiency and utility of the main results.
Oscillation of Solutions of Nonlinear Difference Equation With a Super-linear Neutral Term
Authors: Dharuman C. , Thandapani E.
Published: May 2018

This paper deals with the oscillation of solutions of certain class of neutral difference equation ∆(an∆(χn + pnχαn−k)) + qnχβn+1−l = 0, where α and β are ratio of odd positive integers. New sufficient conditions are obtained for the oscillation of studied equation and examples illustrating the main results are provided.
Facile synthesis of preformed mixed nano-carbon structure from low rank coal
Authors: Manoj B. , Raj Ashlin M. , Chirayil George Thomas
Published: May 2018

Coal is a natural energy resource which is mainly used for energy production via combustion. Coal has nanocrystals embedded in it, formed during the coalification process, and is an ideal precursor for nano-carbon dots and diamonds. Herein, we report a facile top-down method to synthesise nanodots and diamonds of the size of 5 nm to 10 nm from three different types of coal by simple chemical leaching. TEM analysis revealed the formation of a mixture of carbon dots, graphene layers, and quantum dots in bituminous coal and sub-bituminous coal. Raman analysis confirmed the existence of synthesized nanodiamond and nano-carbon mixed phase with defects associated with it. It is concluded that graphene quantum dots, nanodiamonds, graphene sheets and carbon dots present in coal can be extracted by simple chemical treatment. These structures can be tuned to photoluminescent material for various optoelectronic applications or energy harvesting devices like super capacitors.
Structural and electrical characterization of La3+substituted PMS-PZT (Zr/Ti:60/40) ceramics
Authors: Menasra H. , Necira Z. , Bounabe K. , Abba M. , Meklid A. , Boutarfaia A.
Published: May 2018

Pb(1-x)Lax[(Zr0.6Ti0.4)(1-x)(Mn1/3Sb2/3)x]O3ceramics with x = 0.02, 0.03, 0.04, and 0.05 were synthesized by using a conventional solid state reaction route. The influence of La, Mn, and Sb contents on phase structure, microstructure, and electric properties were investigated. The results of X-ray diffraction (XRD) show that the phase structure of the ceramics transforms from rhombohedral phase to tetragonal phase. However, the minority pyrochlore phase appears on the micrographs of XRD and SEM if the doping concentration is greater than 2 mol%. The grain size of the ceramics gradually increases (from 1.36 μm to 1.57 μm) with increasing doping. The dielectric properties of the ceramics have been measured as a function of temperature in the range of 20 °C to 430 °C at 1 kHz. The results indicate that the transition temperature and the maximum dielectric constant decrease with increasing PL-PMS content in the system. These results clearly show the significance of PL-PMS in controlling the dielectric behavior of the PL-PMS-PZT system.
Hybrid Ni/SiO2/Au dimer arrays for high-resolution refractive index sensing
Authors: Pourjamal Sara , Kataja Mikko , Maccaferri Nicolò , Vavassori Paolo , van Dijken Sebastiaan
Published: May 2018

We introduce a novel magnetoplasmonic sensor concept for sensitive detection of refractive index changes. The sensor consists of a periodic array of Ni/SiO2/Au dimer nanodisks. Combined effects of near-field interactions between the Ni and Au disks within the individual dimers and far-field diffractive coupling between the dimers of the array produce narrow linewidth features in the magneto-optical Faraday spectrum. We associate these features with the excitation of surface lattice resonances and show that they exhibit a spectral shift when the refractive index of the surrounding environment is varied. Because the resonances are sharp, refractive index changes are accurately detected by tracking the wavelength where the Faraday signal crosses 0. Compared to random distributions of pure Ni nanodisks or Ni/SiO2/Au dimers or periodic arrays of Ni nanodisks, the sensing figure of merit of the hybrid magnetoplasmonic array is more than one order of magnitude larger.
Crystal structure of poly[aqua-(μ2-5-methoxyisophthalate-κ3
O,O′:O′′)-(μ2-1,4-bis((1H-1,2,4-triazol-1-yl)methyl)benzene-κ2
N:N′)nickel(II), NiC21H20N6O6
Authors: Fu Hong-Ru
Published: May 2018

C21H20NiN6O6, triclinic, P1̄ (no. 2), a = 10.1526(16) Å, b = 11.0670(18) Å, c = 11.1729(18) Å, α = 71.559(2)°, β = 69.827(2)°, γ = 70.439(2)°, V = 1081.3(3) Å3, Z = 2, R
gt(F) = 0.0370, wR
ref(F
2) = 0.0911, T = 296(2) K.
Crystal structure of 3-methyl-2,3-dihydro-2-thioxoquinazolin-4(1H)-one, C9H8N2OS
Authors: Wu Hao , Zong Hai-Tao
Published: May 2018

C9H8N2OS, monoclinic, C2/c (no. 15), a = 24.273(5) Å, b = 9.026(2) Å, c = 8.2852(19) Å, β = 108.818(4)°, V = 1718.2(7) Å3, Z = 8, R
gt(F) = 0.0438, wR
ref(F
2) = 0.1190, T = 296(2) K.
Crystal structure of caffeinium triiodide – caffeine (1/1), C16H21I3N8O4
Authors: Merkelbach Johannes , Majewski Martha A. , Reiss Guido J.
Published: May 2018

C16H21I3N8O4, monoclinic, P21/n (no. 14), a = 14.7257(7) Å, b = 10.5712(5) Å, c = 16.7501(8) Å, β = 114.408(2)°, V = 2374.4(2) Å3, Z = 4, R
gt(F) = 0.0254, wR
ref(F
2) = 0.0760, T = 290(2) K.
Preliminary study on character associations, phenotypic and genotypic divergence for yield and related quantitative traits among cowpea landraces (Vigna unguiculata) from the Western Highland Region of Cameroon
Authors: Kouam Eric Bertrand , Ngompe-Deffo Toscani , Anoumaa Mariette , Pasquet Remy Stéphane
Published: May 2018

Cowpea (Vigna unguiculata) is an important tropical legume crop contributing significantly to food security in tropical regions. The present study was carried out to determine the extent of genetic variation, to estimate character associations, heritability and genetic advance of 25 quantitative traits in 30 genotypes of cultivated Vigna unguiculata from the western highland region of Cameroon. These quantitative traits were selected among cowpea descriptor lists. For all these traits, the analysis of variance showed significant difference among genotypes, highlighting the existence of important genetic divergence among the studied accessions. The highest phenotypic and genotypic coefficient of variation was observed in grain yield, pod yield and 100 seed weight. Genetic advance of these three characters was also the highest. Broad sense heritability was high in general, with 20 traits out of 25 having heritability values greater than 70%. This high heritability indicates little influence of the environment on these characters in cowpea. The highest heritability was recorded for 100 seed weight (98.15%) and the lowest for shoot weight (41.38%). At 0.05 probability level, grain yield correlated significantly with 21 out of the 24 other quantitative traits. Among others, grain yield correlated positively and significantly with 100 seed weight, number of pods per plant, number of branches per plant, number of nodes per plant, plant height, plant width, pod length, pod width, seed length, seed width and number of seeds per pod. These positive correlations between grain yield and many other traits indicate that a selection program based on any of these traits will result in increasing yield. Cluster analysis using UPGMA method revealed five distinct clusters. Genotypes named KEBCP025, KEB-CP006, KEB-CP098, KEB-CP070, and more importantly KEB-CP054 and KEB-CP004, were grouped in a single cluster and were characterized by a significantly higher grain yield, pod yield, number of pods per plant, number of seed per pod, plant height, pod length and pod width compared to other clusters. Accessions KEB-CP036 and KEB-CP031 produced significantly more important fresh biomass. These genotypes could be used as parents in genetic improvement programs aiming to increase yield and fresh biomass in cowpea.
A Strategic Niche Management approach for shaping bio-based economy in Europe
Authors: Tani Almona
Published: May 2018

The goal of this paper is to investigate the transition towards a bio-based economy as part of a broader sustainable transition in Europe. To analyse the challenges and opportunities associated with the bio-based economy, we applied the Strategic Niche Management approach to investigate the drivers that boost the emergence of the bio-based economy, the factors hindering it, as well as institutional changes which are at the base of the socio-technological transition. Although considered as just one piece of the sustainability puzzle, the bio-based economy behaves as a socio-technical system on its own, providing valuable hints on systemic transitions.
Band Bending at the Gold (Au)/Boron Carbide-Based Semiconductor Interface
Authors: Echeverría Elena , Peterson George , Dong Bin , Gilbert Simeon , Oyelade Adeola , Nastasi Michael , Kelber Jeffry A. , Dowben Peter A.
Published: May 2018

We have used X-ray photoemission spectroscopy to study the interaction of gold (Au) with novel boron carbide-based semiconductors grown by plasma-enhanced chemical vapor deposition (PECVD). Both n- and p-type films have been investigated and the PECVD boron carbides are compared to those containing aromatic compounds. In the case of the p-type semiconducting PECVD hydrogenated boron carbide samples, the binding energy of the B(1s) core level shows a shift to higher binding energies as the Au is deposited, an indication of band bending and possibly Schottky barrier formation. In the case of the n-type boron carbide semiconductors the interaction at the interface is more typical of an ohmic contact. Addition of the aromatic compounds increases the change in binding energies on both n-type and p-type PECVD boron carbide semiconductors, and the gold appears to diffuse into the PECVD boron carbides alloyed with aromatic moieties.