bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of wide band slotted microstrip patch antenna with defective ground structure for ku band
Authors: Davuluri Akhila John , Siddaiah P.
Published: February 2021

This paper proposes a microstrip patch antenna (MSPA) in the Ku band for satellite applications. The antenna is small in size with dimensions of about 40 mm×48 mm×1.59 mm and is fed with a coaxial cable of 50 Ω impedance. The proposed antenna has a wide bandwidth of 3.03 GHz ranging from 12.8 GHz to 15.8 GHz. To realize the characteristics of wideband the techniques of defective ground structure (DGS) and etching slots on the radiating element are adopted. The antenna is modeled on the FR4 substrate. A basic circular patch is selected for the design of a dual-frequency operation and in the next step DGS is introduced into the basic antenna and enhanced bandwidth is achieved at both the frequencies. To attain wider bandwidth two slots are etched on the radiating element of which one is a square ring slot and the second one is a circular ring slot. The novelty of the proposed antenna is a miniaturized design and unique response within the Ku band region which is applicable for wireless UWB applications with VSWR <2 and an average gain of 3.6 dB.
New method for summative evaluation of UML class diagrams based on graph similarities
Authors: Anas Outair , Mariam Tanana , Abdelouahid Lyhyaoui
Published: February 2021

This paper deals with the problem of the evaluation of the student's productions during the construction of a UML class diagram from textual speciations, which can be a tedious task for teachers. The main objective is to propose a method of summative and semi-automatic evaluation of the class diagrams produced by the students, in order to provide an educational reaction on the learning process, and to reduce the evaluation work for the teachers. To achieve this objective, we must analyze these productions and study the transformation, matching, similarity measurement and comparison of several UML graphs. From this study, we adopted a method based on the comparison and matching of the components of several UML diagrams. This proposal is applied to evaluate UML class diagrams and focuses on the structural and semantic aspects of the UML graph produced by students compared to several solutions proposed by the teacher.
Arabic tweeps dialect prediction based on machine learning approach
Authors: Alrifai Khaled , Rebdawi Ghaida , Ghneim Nada
Published: February 2021

In this paper, we present our approach for profiling Arabic authors on twitter, based on their tweets. We consider here the dialect of an Arabic author as an important trait to be predicted. For this purpose, many indicators, feature vectors and machine learning-based classifiers were implemented. The results of these classifiers were compared to find out the best dialect prediction model. The best dialect prediction model was obtained using random forest classifier with full forms and their stems as feature vector.
Enhancing cloud computing security by paillier homomorphic encryption
Authors: Saeed Altaee Muna Mohammed , Alanezi Mafaz
Published: February 2021

In recent years, the trend has increased for the use of cloud computing, which provides broad capabilities with the sharing of resources, and thus it is possible to store and process data in the cloud remotely, but this (cloud) is untrusted because some parties can connect to the network such as the internet and read or change data because it is not protected, therefore, protecting data security and privacy is one of the challenges that must be addressed when using cloud computing. Encryption is interested in the field of security, confidentiality and integrity of information that sent by a secure connection between individuals or institutions regardless of the method used to prepare this connection. But using the traditional encryption methods to encrypt the data before sending it will force the data provider to send his private key to the server to decrypt the data to perform computations on it. In this paper we present a proposal to secure banking data transmission through the cloud by using partially homomorphic encryption algorithms such as (paillier, RSA algorithm) that allow performing mathematical operations on encrypted data without needing to decryption. A proxy server will also use for performing re-encryption process to enhance security.
Growth of relational model: Interdependence and complementary to big data
Authors: Shetty Sucharitha , Rao B. Dinesh , Prabhu Srikanth
Published: February 2021

A database management system is a constant application of science that provides a platform for the creation, movement, and use of voluminous data. The area has witnessed a series of developments and technological advancements from its conventional structured database to the recent buzzword, bigdata. This paper aims to provide a complete model of a relational database that is still being widely used because of its well known ACID properties namely, atomicity, consistency, integrity and durability. Specifically, the objective of this paper is to highlight the adoption of relational model approaches by bigdata techniques. Towards addressing the reason for this in corporation, this paper qualitatively studied the advancements done over a while on the relational data model. First, the variations in the data storage layout are illustrated based on the needs of the application. Second, quick data retrieval techniques like indexing, query processing and concurrency control methods are revealed. The paper provides vital insights to appraise the efficiency of the structured database in the unstructured environment, particularly when both consistency and scalability become an issue in the working of the hybrid transactional and analytical database management system.
Design and implementation of speech recognition system integrated with internet of things
Authors: Abdulkareem Ademola , Somefun Tobiloba E. , Chinedum Oji K. , Agbetuyi Felix
Published: February 2021

The process of speech recognition is such that a speech signal from a client or user is received by the system through a microphone, then the system analyses this signal and extracts useful information from the signal which is converted to text. This study focuses on the design and implementation of a speech recognition system integrated with internet of thing (IoT) to control electrical appliances and door with raspberry pi as a core element. To design the speech recognition system, digital signal processing (DSP) technique and hidden Markov model were fully considered for processing, extraction and high predictive accuracy of the system. The Google application programming interface (API) was used as a cloud server to store command and give the system to assess to the internet. With 150 speech samples on the system, a high level of accuracy of over 80% was obtained.
Minimize the load reduction considering the activities control of the generators and phase distance
Authors: Nghia Le Trong , Anh Quyen Huy , Thanh Binh Phan Thi , Tan Phung Trieu
Published: February 2021

This study shows how to calculate the minimum load that needs to be reduced to restore the frequency to the specified threshold. To implement this problem, the actual operation of the electricity system in the event of a generator outage is considered. The main idea of this method is to use the power balance equation between the generation and the load with different frequency levels. In all cases of operating the electrical system before and after the generator outage, the reserve capacity of other generators is considered in each generator outage situation. The reduced load capacity is calculated based on the reciprocal phase angle sensitivity or phase distance. This makes the voltage phase angle and voltage value quality of recovery nodes better. The standard IEEE 9-generator 37-bus test scheme was simulated to show the result of the proposed technique.
ANFIS control of a shunt active filter based with a five-level NPC inverter to improve power quality
Authors: Tounsi Mahmoud Mostefa , Allali Ahmed , Boulouiha Houari Merabet , Denaï Mouloud
Published: February 2021

This paper addresses the problem of power quality, and the degradation of the current waveform in the distribution network which results directly from the proliferation of the nonlinear loads. We propose to use a five-level neutral point clamped (NPC) inverter topology for the implementation of the shunt active filter (SAPF). The aim of the SAPF is to inject harmonic currents in phase opposition at the connection point. The identification of harmonics is based on the pq method. A neuro-fuzzy controller based on ANFIS (adaptive neuro fuzzy inference system) is designed for the SAPF. The simulation study is carried out using MATLAB/Simulink and the results show a significant improvement in the quality of energy and a reduction in total harmonic distortion (THD) in accordance with IEC standard, IEEE-519, IEC 61000, EN 50160.
Minimize electricity generation cost for large scale wind- thermal systems considering prohibited operating zone and power reserve constraints
Authors: Vinh Phan Nguyen , Dinh Bach Hoang , Phan Van-Duc , Nguyen Hung Duc , Nguyen Thang Trung
Published: February 2021

Wind power plants (WPs) play a very important role in the power systems because thermal power plants (TPs) suffers from shortcomings of expensive cost and limited fossil fuels. As compared to other renewable energies, WPs are more effective because it can produce electricity all a day from the morning to the evening. Consequently, this paper integrates the optimal power generation of TPs and WPs to absolutely exploit the energy from WPs and reduce the total electricity generation cost of TPs. The target can be reached by employing a proposed method, called one evaluation-based cuckoo search algorithm (OEB-CSA), which is developed from cuckoo search algorithm (CSA). In addition, conventional particle swarm optimization (PSO) is also implemented for comparison. Two test systems with thirty TPs considering prohibited working zone and power reserve constraints are employed. The first system has one wind power plant (WP) while the second one has two WPs. The result comparisons indicate that OEB-CSA can be the best method for the combined systems with WPs and TPs.
A new speech encryption algorithm based on dual shuffling Hénon chaotic map
Authors: Al-hazaimeh Obaida M.
Published: February 2021

Over the past few decades, many algorithms have been proposed to improve the performance of speech encryption over un-secure channel (i.e., Internet). In this paper, the security level was enhanced using a dynamic dual chaotic based on Hénon chaotic map. In the proposed algorithm, the speech elements are shuffled in a random fashion. Moreover, when both Hénon state variables are free to be used for shuffling the index is toggled randomly between them according to toggle bit. After index shuffling each speech element is modified with XOR operation between the original speech element value and the key that is selected randomly from the updated key table. The same chaotic map is used to initiate the empty or full table and provide new table entries from the values that are already shuffled. The experimental results show that the proposed crypto-system is simple, fast with extra random toggling behavior. The high order of substitution make it sensitive to initial condition, common cryptanalysis attacks such as linear and differential attacks are infeasible.
Adaptation and parameters studies of CS algorithm for flow shop scheduling problem
Authors: Belbachir Driss , Boumediene Fatima , Hassam Ahmed , Ghomri Ltéfa
Published: February 2021

Scheduling concerns the allocation of limited resources overtime to perform tasks to fulfill certain criterion and optimize one or several objective functions. One of the most popular models in scheduling theory is that of the flow-shop scheduling. During the last 40 years, the permutation flow-shop sequencing problem with the objective of makespan minimization has held the attraction of many researchers. This problem characterized as Fm/prmu/Cmax in the notation of Graham, involves the determination of the order of processing of n jobs on m machines. In addition, there was evidence that m-machine permutation flow-shop scheduling problem (PFSP) is strongly NP-hard for m ≥3. Due to this NP-hardness, many heuristic approaches have been proposed, this work falls within the framework of the scientific research, whose purpose is to study Cuckoo search algorithm. Also, the objective of this study is to adapt the cuckoo algorithm to a generalized permutation flow-shop problem for minimizing the total completion time, so the problem is denoted as follow: Fm | | Cmax. Simulation results are judged by the total completion time and algorithm run time for each instance processed.
Cassini-Huygens mission images classification framework by deep learning advanced approach
Authors: AlDabbas Ashraf , Gal Zoltan
Published: February 2021

Developing a deep learning (DL) model for image classification commonly demands a crucial architecture organization. Planetary expeditions produce a massive quantity of data and images. However, manually analyzing and classifying flight missions image databases with hundreds of thousands of images is ungainly and yield weak accuracy. In this paper, we speculate an essential topic related to the classification of remotely sensed images, in which the process of feature coding and extraction are decisive procedures. Diverse feature extraction techniques are intended to stimulate a discriminative image classifier. Features extraction is the primary engagement in raw data processing with the purpose of data classification; when it comes across the task of analysis of vast and varied data, these kinds of tasks are considered as time-consuming and hard to be treated with. Most of these classifiers are either, in principle, quite intricate or virtually unattainable to calculate for massive datasets. Stimulated by this perception, we put forward a straightforward, efficient classifier based on feature extraction by analyzing the cell of tensors via layered MapReduce framework beside meta-learning LSTM followed by a SoftMax classifier. Experiment results show that the provided model attains a classification accuracy of 96.7%, which makes the provided model quite valid for diverse image databases with varying sizes.
TFI-FTS: An efficient transient fault injection and fault-tolerant system for asynchronous circuits on FPGA platform
Authors: Y. N. Sharath Kumar , P. Dinesha
Published: February 2021

Designing VLSI digital circuits is challenging tasks because of testing the circuits concerning design time. The reliability and productivity of digital integrated circuits are primarily affected by the defects in the manufacturing process or systems. If the defects are more in the systems, which leads the fault in the systems. The fault tolerant systems are necessary to overcome the faults in the VLSI digital circuits. In this research article, an asynchronous circuits based an effective transient fault injection (TFI) and fault tolerant system (FTS) are modelled. The TFI system generates the faults based on BMA based LFSR with faulty logic insertion and one hot encoded register. The BMA based LFSR reduces the hardware complexity with less power consumption on-chip than standard LFSR method. The FTS uses triple mode redundancy (TMR) based majority voter logic (MVL) to tolerant the faults for asynchronous circuits. The benchmarked 74X-series circuits are considered as an asynchronous circuit for TMR logic. The TFI-FTS module is modeled using Verilog-HDL on Xilinx-ISE and synthesized on hardware platform. The Performance parameters are tabulated for TFI-FTS based asynchronous circuits. The performance of TFI-FTS Module is analyzed with 100% fault coverage. The fault coverage is validated using functional simulation of each asynchronous circuit with fault injection in TFI-FTS Module.
Effects of physical and chemical factors on Ephemeroptera (Insecta) assemblages in an urban river of the eastern Colombian Llanos
Authors: Rojas-Peña Jose Ismael , Vásquez-Ramos Jesús Manuel , Salinas-Jiménez Luis Gonzalo , Osorio-Ramirez Diana Paola , Caro-Caro Clara Inés
Published: February 2021

The mayflies are insects widely known as indicators of aquatic quality in freshwater systems, they are abundant and diverse in tropical streams. In this study, it was determined the influence of physical, chemical and bacteriological characteristics on the Ephemeroptera assembly in a period of low precipitation in the Ocoa river of Meta department. There were 5,332 nymphs belonging to 4 families, 10 genera and 3 species. Three new genera records and one species are presented for Meta: Cloeodes, Zelusia, Lumahyphes and Americabaetis alphus. The genera Camelobaetidius and Varipes were found associated with conditions of contamination by organic matter and water mineralization. Likewise, Americabaetis, Thraulodes, Lumahyphes and Tricorythodes were associated with contamination conditions, especially with nitrites and nitrates. Nanomis, Cloeodes and Zelusia showed greater sensitivity to the contamination condition and were related to high percentages of dissolved oxygen in the water and they were in the sampling stations of the upper part in the river. It is important to mention that there were not Ephemeroptera in most of the stations associated with the urban area. That reflects their high sensitivity to polluting conditions at low precipitation period.
Morphological description of Cyrtopleura costata (Bivalvia: Pholadidae) from southern Brazil
Authors: Stakowian Nicole , Simone Luiz Ricardo Lopes de
Published: February 2021

The aim of the study is to describe in detail, for the first time, the internal and external anatomy of Cyrtopleura costata, which displays ellipsoid and elongated valves with beige periostracum, the anterior adductor muscle unites the valves in the pre-umbonal region, with abduction capacity in its dorsal half, sparing the ligament. Two accessory valves are identified: the mesoplax (calcified) located in the umbonal region; and the protoplax (corneus) above the anterior adductor muscle. Internally there is a pair of well-developed apophysis that supports the labial palps and the pedal muscles, and support part of the gills. The posterior half of mantle ventral edge is fused and richly muscular, working as auxiliary adductor muscle. The siphons are completely united with each other, the incurrent being larger than the excurrent. The foot is small (about ⅛ the size of the animal). The kidneys extend laterally on the dorsal surface, solid, presenting a brown/reddish color. The style sac is well developed and entirely detached from the adjacent intestine. The intestine has numerous loops and curves within the visceral mass. The fecal pellets are coin-shaped. The present study certainly may be used as comparative scenario for specimens from other regions of the species range.
Deus, Pai, Intermediário: a função de Amon no discurso de Hatshepsut
Authors: Pires Rafael dos Santos
Published: February 2021

O presente artigo tem por foco analisar como a religião está inserida na construção da política na sociedade egípcia do Reino Novo inicial (c. 1550-1425 a.C.) através dos discursos oficiais voltados à realeza. Observamos também que o elo entre político e religioso é estabelecido a partir de relações de parentesco. O estudo de caso será o contexto da faraó Hatshepsut (c. 1479-1458 a.C.) e a narrativa de sua concepção localizada no templo mortuário de Deir el-Bahari, Tebas Ocidental. Acreditamos que, desse modo, seja possível observar como as esferas religiosa, política e de parentesco exerceram influência na construção e na manutenção do discurso do Estado egípcio nesse período.
A construção de templos: a arquitetura religiosa no período augustano
Authors: Cunha Macsuelber de Cássio Barros da
Published: February 2021

O templo era uma das principais expressões da cultura material no que se refere à religião e à religiosidade no Mundo Antigo. Na Roma do período augustano não era diferente, de tal forma que a construção de templos obedecia a regras precisas, além de estar ligada a estratégias políticas, pois conferia glória aos seus responsáveis. Neste trabalho, analisamos o processo de construção de templos, suas características gerais e as principais regras para a construção da moradia das divindades, bem como a importância que a construção de templos teve neste período. Para tanto, nos utilizamos do De Architectura, de Vitrúvio, bem como dos vestígios da cultura material da época.
Mar, lagos e lagunas: poesia na pesquisa artística de um músico
Authors: Ballestero Luiz Ricardo Basso
Published: February 2021

No meu processo investigativo como músico, pesquisador e docente, aproximei-me da autoetnografia com a intenção de me ouvir, me ver e me entender (um pouco) melhor. Talvez a minha grande questão de pesquisa (e de vida) seja essa: como eu vejo a relação entre a pesquisa e as artes na Universidade? Como resultado, escrevi um poema-manifesto (!?) que se coloca contra certas convenções investigativas e a favor de uma maior fluidez disciplinar e metodológica na pesquisa artística.
Vestígios e marcas além das humanas
Authors: Gomes Jaqueline
Published: February 2021

Este ensaio foi construído através de uma incursão ao Igarapé do Baré, um curso hídrico de águas pretas que deságua nas cabeceiras do Lago Amanã, que dá nome à uma Reserva de Desenvolvimento Sustentável, no baixo rio Japurá, Estado do Amazonas. A pesquisa que venho desenvolvendo tem caráter etnográfico e parte de questões arqueológicas sobre construção e transformação de lugares os relacionando ao processo de antropização do bioma. Busca entender como coletivos ribeirinhos contemporâneos se relacionam com as paisagens onde estão inseridos sítios arqueológicos que remontam a uma História Antiga da Amazônia. As imagens são como vestígios do meu próprio percurso de pesquisa em uma arqueologia como prática de sentido. Essas fotografias são índices de uma expansão de um olhar – antes direcionado para marcas humanas sobre os lugares – agora repleto de sinais e vestígios de seres animais, vegetais e cosmológicos que povoam as águas e florestas de Amanã.
Por uma sensibilização do olhar – sobre a importância da fotografia na formação do antropólogo
Authors: Novaes Sylvia Caiuby
Published: February 2021

Nesse texto, procuro associar a pesquisa de campo antropológica ao próprio ato fotográfico, mostrando o que há de comum nessas duas atividades: a necessidade de recorte, de proximidade, de intimidade e empatia, a decisão sobre o que estará ou não em foco. A partir de minhas experiências na Escola de Arte Brasil, falo sobre a sensibilização do olhar, a necessidade de criar repertórios e a oportunidade que a fotografia oferece de mudar o foco – do verbo para o comportamento, o corpo, os gestos, os detalhes sobre os quais nem sempre é possível falar. Procuro ainda ressaltar a associação da fotografia com a narrativa de que fala Walter Benjamin, a capacidade tanto da narrativa, quanto da fotografia, de acolher a experiência de quem a ouve ou contempla.
The oat-like grass Trisetopsis aspera (Munro ex Thwaites) Röser & A.Wölk (Poaceae): a new record for the flora of central Western Ghats of Karnataka, India
Authors: Abhijit H.U. , Krishnamurthy Y.L. , Bhat K. Gopalakrishna
Published: February 2021

For the documentation of grasses in the central Western Ghats of Karnataka, we have conducted the extensive field surveys by using random sampling method from 2017 to 2020.  During this survey we have collected some grass specimens from the shola grassland, which forms the new distributional record of Trisetopsis aspera (Munro ex Thwaites) Roser & A. Wolk to the flora of central Western Ghats, Karnataka, India from the montane high- lands of Baba Budangiri hills of Chikkamagaluru District.
Bulbophyllum spathulatum (Orchidaceae), a new record for Bhutan
Authors: Zangpo Pema , Gyeltshen Phub , Kumar Pankaj
Published: February 2021

Bulbophyllum spathulatum (Orchidaceae), a native to Eastern Himalaya, China, and Indochina is recorded from Bhutan for the first time.  Detailed morphological descriptions, distribution, phenology, and ecology along with colour photographic plate are provided.
Administrative Claims Measure for Profiling Hospital Performance Based on 90-Day All-Cause Mortality Following Coronary Artery Bypass Graft Surgery
Authors: Mori Makoto , Nasir Khurram , Bao Haikun , Jimenez Andreina , Legore Shani S. , Wang Yongfei , Grady Jacqueline , Lama Sonam D , Brandi Nina , Lin Zhenqiu , Kurlansky Paul , Geirsson Arnar , Bernheim Susannah M , Krumholz Harlan M , Suter Lisa G.
Published: February 2021

Background:

Coronary artery bypass graft (CABG) surgery is a focus of bundled and alternate payment models that capture outcomes up to 90 days postsurgery. While clinical registry risk models perform well, measures encompassing mortality beyond 30 days do not currently exist. We aimed to develop a risk-adjusted hospital-level 90-day all-cause mortality measure intended for assessing hospital performance in payment models of CABG surgery using administrative data.

Methods:

Building upon Centers for Medicare and Medicaid Services hospital-level 30-day all-cause CABG mortality measure specifications, we extended the mortality timeframe to 90 days after surgery and developed a new hierarchical logistic regression model to calculate hospital risk-standardized 90-day all-cause mortality rates for patients hospitalized for isolated CABG. The model was derived from Medicare claims data for a 3-year cohort between July 2014 to June 2017. The data set was randomly split into 50:50 development and validation samples. The model performance was evaluated with C statistics, overfitting indices, and calibration plot. The empirical validity of the measure result at the hospital level was evaluated against the Society of Thoracic Surgeons composite star rating.

Results:

Among 137 819 CABG procedures performed in 1183 hospitals, the unadjusted mortality rate within 30 and 90 days were 3.1% and 4.7%, respectively. The final model included 27 variables. Hospital-level 90-day risk-standardized mortality rates ranged between 2.04% and 11.26%, with a median of 4.67%. C statistics in the development and validation samples were 0.766 and 0.772, respectively. We identified a strong positive correlation between 30- and 90-day risk-standardized mortality rates, with a regression slope of 1.09. Risk-standardized mortality rates also showed a stepwise trend of lower 90-day mortality with higher Society of Thoracic Surgeons composite star ratings.

Conclusions:

We present a measure of hospital-level 90-day risk-standardized mortality rates following isolated CABG. This measure complements Centers for Medicare and Medicaid Services’ existing 30-day CABG mortality measure by providing greater insight into the postacute recovery period. It offers a balancing measure to ensure efforts to reduce costs associated with CABG recovery and rehabilitation do not result in unintended consequences.
Associations of Left Atrial Function and Structure With Supraventricular Ectopy: The Multi‐Ethnic Study of Atherosclerosis
Authors: Heckbert Susan R. , Jensen Paul N. , Austin Thomas R. , Chen Lin Yee , Post Wendy S. , Ambale Venkatesh Bharath , Soliman Elsayed Z. , Floyd James S. , Sotoodehnia Nona , Kronmal Richard A. , Lima Joao A. C.
Published: February 2021

Background

High levels of supraventricular ectopy are associated with greater risk of atrial fibrillation, stroke, and death. Little information is available about differences by race/ethnicity in the extent of supraventricular ectopy, or about whether high levels of supraventricular ectopy are associated with impaired left atrial (LA) function and LA enlargement.

Methods and Results

In the MESA (Multi‐Ethnic Study of Atherosclerosis), 1148 participants (47% men; mean age, 67 years) had cardiovascular magnetic resonance imaging in 2010 to 2012, followed by 14‐day ambulatory electrocardiographic monitoring in 2016 to 2018. We analyzed participant characteristics and cardiovascular magnetic resonance measures of LA function and structure in relation to average count of premature atrial contractions (PACs) per hour and average number of runs per day of supraventricular tachycardia. In adjusted regression analyses, older age, male sex, White race, elevated NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), and a history of clinically detected atrial fibrillation were associated with more PACs/hour. Chinese and Hispanic participants had on average fewer PACs/hour than White participants (Chinese participants, 31% less [95% CI, 8%–49%]; Hispanic participants, 38% less [95% CI, 19%–52%]). Greater LA total emptying fraction was associated with fewer PACs/hour (per SD, 16% fewer PACs/hour [95% CI, 7%–25% fewer PACs/hour]). Larger LA minimum volume was associated with more PACs/hour (per SD, 7% more PACs/hour [95% CI, 2%–13% more PACs/hour]). Associations of LA volumes with runs of supraventricular tachycardia/day were similar in direction but were weaker.

Conclusions

Impaired LA function and LA enlargement were associated with more PACs/hour on extended ambulatory electrocardiographic monitoring. Measurement of supraventricular ectopy may provide information about the extent of atrial myopathy.
“Why Study Uṣūl al-Fiqh?”: The Problem of Taqlīd and Tough Cases in 4th-5th /10th-11th Century Iraq
Authors: Soufi Youcef L.
Published: February 2021

The function of uṣūl al-fiqh (legal theory) within classical Islamic law has been the object of protracted debate. Based on the writings of Abū Isḥāq al-Shīrāzī (d.476/1083), I propose that uṣūl al-fiqh served two pedagogical purposes within the Iraqi legal community of the 4th/10th and 5th/11th centuries: first, to avoid taqlīd, defined as the subscription to a position without evidence; and second, to provide jurists with tools to assess the validity of a proof when they were confused about its merits. My analysis sheds light on uṣūl al-fiqh’s role in providing epistemological foundations for juristic reasoning. It also reveals that practical engagement on disputed legal matters (masāʾil al-khilāf) prevailed over uṣūl al-fiqh in the training of jurists. The consequence: uṣūl al-fiqh was a methodology of last resort.
Spathodea Campanulata: Een Antidiabetisch Geneesmiddel?
Authors: Laekeman Gert
Published: February 2021

Decoctions of the stem back of Spathodea campanulata (SC) are currently used in Rwanda to treat insulin- and non insulin-dependent diabetics. In order to confirm and farther examine hypoglycemic activity of this plant we set up a research project with as final objective a possible standardisation of Spathodea in antidiabetic therapy in Rwanda.

Up to now we were able to confirm the blood sugar lowering effect of SC in hyperglycemic mice (hyperglycemia provoked by streptozotocin = SZ). Also hyperglycemia in glucose loaded mice (glucose tolerance test = GTT) could be tempered by SC. Despite these clearcut hypoglycemic activity, no rise of insulin was seen in the SC treated mice. The activity must be due to some other mechanism of action.

The search for active principles did not lead to satisfying results up to now. We have only indirect evidence for the presence of sugar-like compounds, as SC decoctions enhance the glycemia transiently.

Some hypotheses are formulated with regard to mechanisms of action and active compounds of SC. These aspects will guide future research.
The Natural Environment of the Namib Desert
Authors: van Damme Patrick , Vernemmen Patrick
Published: February 2021

The Topnaar basically live in two distinct areas in the Namib Desert i.e. the Kuiseb river valley and the Sesfontein area. The ecology of both these zones is presented and discussed in detail. Specific attention is given to the plant communities that occur in both of them.
Carnet de Route D’un Voyageur Congolais: Masala à L’exposition universelle D’anvers, en 1885.
Authors: Etambala Zana Aziza
Published: February 2021

Notebook of a Congolese Traveller: Masala at the 1885 Antwerp World Exhibition

Masala, the central figure in this article, came to Belgium to be exhibited, together with eleven other natives of the Congo Independent State, at the International Fancy Fair organized in Antwerp in 1885. Of course, the illiterate Masala didn’t take notes during his stay in Antwerp. But a meticulous investigation of the contemporary local press, which paid enough attention to this event, made it possible to describe in detail the daily european experiences of Masala and his companions. It also enables us to examine the ‘white’ belgian view on the black subjects of Leopold II.
Cradles of Diaspora: Bombay, Aden, and Jewish Migration across the Indian Ocean
Authors: Marmari Shaul
Published: February 2021

During the nineteenth and early twentieth centuries, migrant communities of Middle Eastern Jews emerged across the vast space between Shanghai and Port Said. The present article points to two crucial knots in the creation of these far-reaching Jewish diasporas: Bombay and Aden. These rising port cities of the British Raj were first stations in the migration of thousands of Middle Eastern Jews, and they presented immigrants with new commercial, social, cultural and spatial horizons; it was from there that many of them proceeded to settle elsewhere beyond the Indian Ocean. Using the examples of two prominent families, Sassoon in Bombay and Menahem Messa in Aden, the article considers the role of these places as the cradles from which Jewish diasporas emerged.
The “Pleasures of the Garden:” The Mobility of Plants, People, and Power in the Dutch Indian Ocean Empire
Authors: Burke Kathleen
Published: February 2021

This article combines methodological approaches from global history and food history to demonstrate the multi-direction interactions between mobile people, plants and material culture and the creation of a new global food culture in Batavia, the headquarters of the Dutch East India Company. It reconstructs the global world of Batavia in the eighteenth century and shows how the horticultural, cooking and eating practices of its inhabitants revealed the port city’s connections with distant shores. Batavia was populated by a minority of Europeans, together with more numerous Chinese migrants from Fujian and enslaved people from across the Malay-Indonesian archipelago and the Coromandel, Malabar and Bengal regions of India. Food producers and consumers, traders, and enslaved cooks and cultivators from all these places contributed a diversity of culinary influences that were re-assembled into cooking and eating practices, many of which had never before existed in the same culinary context. While the article uses sources produced by Dutch-speaking colonists, it reads them against the grain in order to reconstruct this diversity of actors, spotlighting the role of enslaved cooks as mobile circulators of knowledge.
From Imperial Port City to Logistics Hub: The Production of Strategic Space in Djibouti (1859–2020)
Authors: Easterly Grace
Published: February 2021

This article examines what I call the production of strategic space, or the process whereby a particular place, the Republic of Djibouti, and its capital, the port city of Djibouti, became strategically valuable to different states over time, including the French Empire, the United States, and China. Throughout the period from 1859 to the present day, Djibouti’s strategic value has fluctuated as states reacted to different political and economic contexts. These events constantly shifted state interests, re-configuring their conceptions of the importance of Djibouti’s territory. As a result of this process, spaces within Djibouti became strategic relative to other spaces. In particular, the port has been more important to the French authorities and other outsiders than the desert hinterland, which was treated mainly as a useless wasteland. The various authorities organized space within Djibouti to reflect these government priorities, which had a profound impact on its inhabitants’ mobilities, economic opportunities, and political freedoms. The ordering of space within Djibouti reflected state interests, exposing the relationship between geography and power, strategy and spatial organization.
Nonlinear Simulations of Gravity Wave Tunneling and Breaking over Auckland Island
Authors: Mixa Tyler , Dörnbrack Andreas , Rapp Markus
Published: February 2021

Horizontally dispersing gravity waves with horizontal wavelengths of 30–40 km were observed at mesospheric altitudes over Auckland Island by the airborne advanced mesospheric temperature mapper during a Deep Propagating Gravity Wave Experiment (DEEPWAVE) research flight on 14 July 2014. A 3D nonlinear compressible model is used to determine which propagation conditions enabled gravity wave penetration into the mesosphere and how the resulting instability characteristics led to widespread momentum deposition. Results indicate that linear tunneling through the polar night jet enabled quick gravity wave propagation from the surface up to the mesopause, while subsequent instability processes reveal large rolls that formed in the negative shear above the jet maximum and led to significant momentum deposition as they descended. This study suggests that gravity wave tunneling is a viable source for this case and other deep propagation events reaching the mesosphere and lower thermosphere.
Evaluating Convective Initiation in High-Resolution Numerical Weather Prediction Models Using GOES-16 Infrared Brightness Temperatures
Authors: Henderson David S. , Otkin Jason A. , Mecikalski John R.
Published: February 2021

The evolution of model-based cloud-top brightness temperatures (BT) associated with convective initiation (CI) is assessed for three bulk cloud microphysics schemes in the Weather Research and Forecasting Model. Using a composite-based analysis, cloud objects derived from high-resolution (500 m) model simulations are compared to 5-min GOES-16 imagery for a case study day located near the Alabama–Mississippi border. Observed and simulated cloud characteristics for clouds reaching CI are examined by utilizing infrared BTs commonly used in satellite-based CI nowcasting methods. The results demonstrate the ability of object-based verification methods with satellite observations to evaluate the evolution of model cloud characteristics, and the BT comparison provides insight into a known issue of model simulations producing too many convective cells reaching CI. The timing of CI from the different microphysical schemes is dependent on the production of ice in the upper levels of the cloud, which typically occurs near the time of maximum cloud growth. In particular, large differences in precipitation formation drive differences in the amount of cloud water able to reach upper layers of the cloud, which impacts cloud-top glaciation. Larger cloud mixing ratios are found in clouds with sustained growth leading to more cloud water lofted to the upper levels of the cloud and the formation of ice. Clouds unable to sustain growth lack the necessary cloud water needed to form ice and grow into cumulonimbus. Clouds with slower growth rates display similar BT trends as clouds exhibiting growth, which suggests that forecasting CI using geostationary satellites might require additional information beyond those derived at cloud top.
Student absenteeism and ecological agency
Authors: Kipp Andrew L , Clark J Spencer
Published: February 2021

The purpose of this article is to address student absenteeism through the theoretical lens of ecological agency and to encourage the use of ecological agency in a school setting to address student absenteeism more holistically. We align absenteeism research within the ecological agency framework and suggest that absenteeism is a manifestation of agency influenced by contextual factors unique to the student’s ecological context and reinforced through punishment. Observing absenteeism through the lens of ecological agency provides an alternative, unique viewpoint giving insight into the process of how students choose to engage in absenteeism based on their ecological factors. The article also intends to illustrate pragmatic use of viewing absenteeism through the lens of ecological agency by providing a sample of interventions that are used to resolve contextual factors and improve student attendance.
Outcomes of Cardiac Diffuse Large B-Cell Lymphoma in the Rituximab Era
Authors: Al-Juhaishi Taha , Abu Zeinah Ghaith , Al-Kindi Sadeer
Published: February 2021

Introduction:

Cardiac lymphomas are very rare with diffuse large B-cell lymphoma (DLBCL) considered to be the most common histology. These lymphomas can be either local "primary cardiac" disease, or part of dissemination by systemic lymphoma. There is limited data regarding outcomes of patients with this disease. We sought to evaluate the outcomes of cardiac DLBCL in both pre- and rituximab eras using a large retrospective database.

Methods:

The public Surveillance, Epidemiology and End Results (SEER) database was used to identify all patients diagnosed with DLBCL and heart as the primary disease site. Data cutoff in the database was in 2016. Patients with missing date of diagnosis or survival data were excluded. Patients were divided into two groups based on diagnosis year, with rituximab cohort included all DLBCLs diagnosed in 2006 and later (2006 was FDA approval year of rituximab in untreated DLBCL). Treatment effect (surgery, radiation, chemotherapy) was analyzed when available. survival was estimated using the Kaplan-Meier method, and compared using Log-Rank test. Cox proportional hazards models were used for adjusted survival analyses.

Results:

Total of 106 patients were included in the final analysis, baseline characteristics are summarized in table 1. Median age at diagnosis was 69.5 years with only about 10% of patients being 50 years or younger. Most patients were white 71 (67%), had local stage I/II disease 68 (64.2%), and belonged to the rituximab era group 71 (67%). Most patients had chemotherapy 82 (77.4%), while only 25 (23.6%) had surgery, and 16 (15.1%) had radiotherapy. Median overall survival (OS) for the entire cohort was 22 months (0-292). Median OS was 16 months (95% CI, 0.55 -31) for the pre-rituximab group, and was 26 months (95% CI, 7.5 - 45) for the rituximab group which were not statistically different (p-value =0.340). Median lymphoma-specific survival (LCS) was 30 months (95% CI, 8.0 -52) for the pre-rituximab group, and was 36 months (95% CI, 16 - 158) for the rituximab group which were not statistically different (p-value =0.295). OS and LCS were also not different between the two era groups when stratified by chemotherapy (figure 1). On univariate analysis, Chemotherapy was associated with better OS [HR = 0.472, 95% CI (0.277-0.806); p-value = 0.006] but not LCS [HR = 0.690, 95% CI (0.341-1.396); p-value = 0.302]. Using a multivariate analysis model, both OS and LCS were associated with lymphoma stage, insurance status and age but not with diagnosis era or chemotherapy (table 2).

Conclusion:

Cardiac DLBCLs are rare and affecting mostly the elderly. No significant improvement in outcomes were noted in the current rituximab era. Age, disease stage, and having health insurance were associated with better outcomes. The role of chemotherapy needs further evaluation in larger studies.

Disclosures

No relevant conflicts of interest to declare.
Prognostic value of right atrial dilation in patients with pulmonary embolism
Authors: Lerchbaumer Markus H. , Ebner Matthias , Ritter Christian O. , Steimke Laura , Rogge Nina I.J. , Sentler Carmen , Thielmann Aaron , Hobohm Lukas , Keller Karsten , Lotz Joachim , Hasenfuß Gerd , Wachter Rolf , Hamm Bernd , Konstantinides Stavros V. , Aviram Galit , Lankeit Mareike
Published: February 2021

Aims

Right atrial (RA) dilation and stretch provide prognostic information in patients with cardiovascular diseases. We investigated the prevalence, confounding factors and prognostic relevance of RA dilation in patients with pulmonary embolism (PE).

Methods

Overall, 609 PE patients were consecutively included in a prospective single-centre registry between September 2008 and August 2017. Volumetric measurements of heart chambers were performed on routine non-electrocardiographic-gated computed tomography and plasma concentrations of mid-regional pro-atrial natriuretic peptide (MR-proANP) measured on admission. An in-hospital adverse outcome was defined as PE-related death, cardiopulmonary resuscitation, mechanical ventilation or catecholamine administration.

Results

Patients with an adverse outcome (11.2%) had larger RA volumes (median 120 (interquartile range 84–152)versus102 (78–134) mL; p=0.013), RA/left atrial (LA) volume ratios (1.7 (1.2–2.4)versus1.3 (1.1–1.7); p<0.001) and MR-proANP levels (282 (157–481)versus129 (64–238) pmol·L−1; p<0.001) compared to patients with a favourable outcome. Overall, 499 patients (81.9%) had a RA/LA volume ratio ≥1.0 and a calculated cut-off value of 1.8 (area under the curve 0.64, 95% CI 0.56–0.71) predicted an adverse outcome, both in unselected (OR 3.1, 95% CI 1.9–5.2) and normotensive patients (OR 2.7, 95% CI 1.3–5.6). MR-proANP ≥120 pmol·L−1was identified as an independent predictor of an adverse outcome, both in unselected (OR 4.6, 95% CI 2.3–9.3) and normotensive patients (OR 5.1, 95% CI 1.5–17.6).

Conclusions

RA dilation is a frequent finding in patients with PE. However, the prognostic performance of RA dilation appears inferior compared to established risk stratification markers. MR-proANP predicted an in-hospital adverse outcome, both in unselected and normotensive PE patients, integrating different prognostic relevant information from comorbidities.
Microbiological community structure on logs used for groynes in a riverbank system
Authors: Ishiyama Nanako , Horisawa Sakae , Hara Tadashi , Yoshida Makoto , Momohara Ikuo
Published: February 2021

It is important for civil engineering applications to investigate resistance to wood decay in aqueous environments. DNA from microorganisms inhabiting logs (groynes) that had been used for about 15 years as a water control system to prevent riverbank erosion was extracted and the microbial community structure was examined. DNA was extracted from specimens in four sections, above and under the water, under the ground and from the bottom parts of the logs that were pulled out from the river. Then, barcode sequences for the detection of fungi and bacteria were amplified from each DNA sample by polymerase chain reaction. Microbes were identified from the nucleotide sequences, and the relationships between microbes and environmental conditions were discussed. The wood in the section above the water was significantly decayed, while slight decay and strength loss were observed in the other sections. The white-rot basidiomycete Xeromphalina sp. was detected in the section above the water, suggesting that this fungal species was responsible for the significant decay of the logs in this study. Wood in the sections under the water and under the ground including the bottom of the logs was not decayed even though the fungus was detected in all sections of the logs, suggesting that Xeromphalina sp. could not degrade the wood in the water and underground where the oxygen supply was limited.