bluuebunny/crossref_metadata_2025 huggingface dataset:
An Upper Bound for the Regularity of Symbolic Powers of Edge Ideals of Chordal Graphs
Authors: Seyed Fakhari Seyed Amin
Published: January 2020

Assume that $G$ is a chordal graph with edge ideal $I(G)$ and ordered matching number $\nu_{o}(G)$. For every integer $s\geq 1$, we denote the $s$-th symbolic power of $I(G)$ by $I(G)^{(s)}$. It is shown that ${\rm reg}(I(G)^{(s)})\leq 2s+\nu_{o}(G)-1$. As a consequence, we determine the regularity of symbolic powers of edge ideals of chordal Cameron-Walker graphs.
Families of Major Index Distributions: Closed Forms and Unimodality
Authors: Keith William J.
Published: January 2020

Closed forms for $f_{\lambda,i} (q) := \sum_{\tau \in SYT(\lambda) : des(\tau) = i} q^{maj(\tau)}$, the distribution of the major index over standard Young tableaux of given shapes and specified number of descents, are established for a large collection of $\lambda$ and $i$. Of particular interest is the family that gives a positive answer to a question of Sagan and collaborators. All formulas established in the paper are unimodal, most by a result of Kirillov and Reshetikhin. Many can be identified as specializations of Schur functions via the Jacobi-Trudi identities. If the number of arguments is sufficiently large, it is shown that any finite principal specialization of any Schur function $s_\lambda(1,q,q^2,\dots,q^{n-1})$ has a combinatorial realization as the distribution of the major index over a given set of tableaux.
Poset Homology of Rees Products, and $q$-Eulerian Polynomials
Authors: Shareshian John , Wachs Michelle L.
Published: January 2020

The notion of Rees product of posets was introduced by Björner and Welker in [8], where they study connections between poset topology and commutative algebra. Björner and Welker conjectured and Jonsson [25] proved that the dimension of the top homology of the Rees product of the truncated Boolean algebra $B_n \setminus \{0\}$ and the $n$-chain $C_n$ is equal to the number of derangements in the symmetric group $\mathfrak{ S}$$_n$. Here we prove a refinement of this result, which involves the Eulerian numbers, and a $q$-analog of both the refinement and the original conjecture, which comes from replacing the Boolean algebra by the lattice of subspaces of the $n$-dimensional vector space over the $q$ element field, and involves the (maj,exc)-$q$-Eulerian polynomials studied in previous papers of the authors [32,33]. Equivariant versions of the refinement and the original conjecture are also proved, as are type BC versions (in the sense of Coxeter groups) of the original conjecture and its $q$-analog.
When is the $q$-Multiplicity of a Weight a Power of $q$?
Authors: Harris Pamela E. , Rahmoeller Margaret , Schneider Lisa , Simpson Anthony
Published: January 2020

Berenshtein and Zelevinskii provided an exhaustive list of pairs of weights $(\lambda,\mu)$ of simple Lie algebras $\mathfrak{g}$ (up to Dynkin diagram isomorphism) for which the multiplicity of the weight $\mu$ in the representation of $\mathfrak{g}$ with highest weight $\lambda$ is equal to one. Using Kostant's weight multiplicity formula we describe and enumerate the contributing terms to the multiplicity for subsets of these pairs of weights and show that, in these cases, the cardinality of these contributing sets is enumerated by (multiples of) Fibonacci numbers. We conclude by using these results to compute the associated $q$-multiplicity for the pairs of weights considered, and conjecture that in all cases the $q$-multiplicity of such pairs of weights is given by a power of $q$.
A Note on Hedetniemi's Conjecture, Stahl's Conjecture and the Poljak-Rödl Function
Authors: Tardif Claude , Zhu Xuding
Published: January 2020

We prove that $\min\{\chi(G), \chi(H)\} - \chi(G\times H)$ can be arbitrarily large, and that if Stahl's conjecture on the multichromatic number of Kneser graphs holds, then $\min\{\chi(G), \chi(H)\}/\chi(G\times H) \leq 1/2 + \epsilon$ for large values of $\min\{\chi(G), \chi(H)\}$.
Unextendible Sequences in Finite Abelian Groups
Authors: Zhuang Jujuan
Published: January 2020

Let $G=C_{n_1}\oplus \ldots \oplus C_{n_r}$ be a finite abelian group with $r=1$ or $1 < n_1|\ldots|n_r$, and let $S=(a_1,\ldots,a_t)$ be a sequence of elements in $G$. We say $S$ is an unextendible sequence if $S$ is a zero-sum free sequence and for any element $g\in G$, the sequence $Sg$ is not zero-sum free any longer. Let $L(G)=\lceil \log_2{n_1}\rceil+\ldots+\lceil \log_2{n_r}\rceil$ and $d^*(G)=\sum_{i=1}^r(n_i-1)$, in this paper we prove, among other results, that the minimal length of an unextendible sequence in $G$ is not bigger than $L(G)$, and for any integer $k$, where $L(G)\leq k \leq d^*(G)$, there exists at least one unextendible sequence of length $k$.
Stack Sorting with Increasing and Decreasing Stacks
Authors: Cerbai Giulio , Cioni Lapo , Ferrari Luca
Published: January 2020

We introduce a sorting machine consisting of $k+1$ stacks in series: the first $k$ stacks can only contain elements in decreasing order from top to bottom, while the last one has the opposite restriction. This device generalizes the $\mathfrak{DI}$ machine introduced by Rebecca Smith, which studies the case $k=1$. Here we show that, for $k=2$, the set of sortable  permutations is a class with infinite basis, by explicitly finding an antichain of minimal nonsortable permutations. This construction can easily be adapted to each $k\geqslant 3$. Next we describe an optimal sorting algorithm, again for the case $k=2$. We then analyze two types of left-greedy sorting procedures, obtaining complete results in one case and only some partial results in the other one. We close the paper by discussing a few open questions.
Recognizing Cluster Algebras of Finite Type
Authors: Seven Ahmet I.
Published: January 2020

We compute the list of all minimal 2-infinite diagrams, which are cluster algebraic analogues of extended Dynkin graphs.
Bijective Counting of Tree-Rooted Maps and Shuffles of Parenthesis Systems
Authors: Bernardi Olivier
Published: January 2020

The number of tree-rooted maps, that is, rooted planar maps with a distinguished spanning tree, of size $n$ is ${\cal C}_{n} {\cal C}_{n+1}$ where ${\cal C}_{n}={1\over n+1}{2n \choose n}$ is the $n^{th}$ Catalan number. We present a (long awaited) simple bijection which explains this result. Then, we prove that our bijection is isomorphic to a former recursive construction on shuffles of parenthesis systems due to Cori, Dulucq and Viennot.
Using Determining Sets to Distinguish Kneser Graphs
Authors: Albertson Michael O. , Boutin Debra L.
Published: January 2020

This work introduces the technique of using a carefully chosen determining set to prove the existence of a distinguishing labeling using few labels. A graph $G$ is said to be $d$-distinguishable if there is a labeling of the vertex set using $1, \ldots, d$ so that no nontrivial automorphism of $G$ preserves the labels. A set of vertices $S\subseteq V(G)$ is a determining set for $G$ if every automorphism of $G$ is uniquely determined by its action on $S$. We prove that a graph is $d$-distinguishable if and only if it has a determining set that can be $(d-1)$-distinguished. We use this to prove that every Kneser graph $K_{n:k}$ with $n\geq 6$ and $k\geq 2$ is $2$-distinguishable.
Game List Colouring of Graphs
Authors: Borowiecki M. , Sidorowicz E. , Tuza Zs.
Published: January 2020

We consider the two-player game defined as follows. Let $(G,L)$ be a graph $G$ with a list assignment $L$ on its vertices. The two players, Alice and Bob, play alternately on $G$, Alice having the first move. Alice's goal is to provide an $L$-colouring of $G$ and Bob's goal is to prevent her from doing so. A move consists in choosing an uncoloured vertex $v$ and assigning it a colour from the set $L(v)$. Adjacent vertices of the same colour must not occur. This game will be called game list colouring. The game choice number of $G$, denoted by ch$_g(G)$, is defined as the least $k$ such that Alice has a winning strategy for any $k$-list assignment of $G$. We characterize the class of graphs with ch$_g(G)\le 2$ and determine the game choice number for some classes of graphs.
The Spectral Radius and the Maximum Degree of Irregular Graphs
Authors: Cioabă Sebastian M.
Published: January 2020

Let $G$ be an irregular graph on $n$ vertices with maximum degree $\Delta$ and diameter $D$. We show that $$ \Delta-\lambda_1>{1\over nD}, $$ where $\lambda_1$ is the largest eigenvalue of the adjacency matrix of $G$. We also study the effect of adding or removing few edges on the spectral radius of a regular graph.
A New Upper Bound on the Total Domination Number of a Graph
Authors: Henning Michael A. , Yeo Anders
Published: January 2020

A set $S$ of vertices in a graph $G$ is a total dominating set of $G$ if every vertex of $G$ is adjacent to some vertex in $S$. The minimum cardinality of a total dominating set of $G$ is the total domination number of $G$. Let $G$ be a connected graph of order $n$ with minimum degree at least two and with maximum degree at least three. We define a vertex as large if it has degree more than $2$ and we let ${\cal L}$ be the set of all large vertices of $G$. Let $P$ be any component of $G - {\cal L}$; it is a path. If $|P| \equiv 0 \, ( {\rm mod} \, 4)$ and either the two ends of $P$ are adjacent in $G$ to the same large vertex or the two ends of $P$ are adjacent to different, but adjacent, large vertices in $G$, we call $P$ a $0$-path. If $|P| \ge 5$ and $|P| \equiv 1 \, ( {\rm mod} \, 4)$ with the two ends of $P$ adjacent in $G$ to the same large vertex, we call $P$ a $1$-path. If $|P| \equiv 3 \, ( {\rm mod} \, 4)$, we call $P$ a $3$-path. For $i \in \{0,1,3\}$, we denote the number of $i$-paths in $G$ by $p_i$. We show that the total domination number of $G$ is at most $(n + p_0 + p_1 + p_3)/2$. This result generalizes a result shown in several manuscripts (see, for example, J. Graph Theory 46 (2004), 207–210) which states that if $G$ is a graph of order $n$ with minimum degree at least three, then the total domination of $G$ is at most $n/2$. It also generalizes a result by Lam and Wei stating that if $G$ is a graph of order $n$ with minimum degree at least two and with no degree-$2$ vertex adjacent to two other degree-$2$ vertices, then the total domination of $G$ is at most $n/2$.
KEBIJAKAN DAN POTENSI DAERAH MENGHADAPI BONUS DEMOGRAFI MENUTUP
Authors: Nurjono Agung Darojad
Published: January 2020

Bonus demografi masih di tingkat nasional. Daerah perlu peka terhadap perubahan dinamika kependudukan diwilayahnya bahwa bonus demografi peluang sekali, rentang waktu cukup singkat dan menutup. Penelitian ini bertujuan untuk mengetahui sejauhmana kepekaan pemerintah daerah terhadap bonus demografi dan bagaimana kondisi masyarakat di wilayah yang sedang menghadapi bonus demografi. Metode penelitian menggunakan pendekatan kualitatif deskriptif. Lokus penelitian ditentukan berdasarkan kriteria wilayah yang sedang mengalami bonus demografi yaitu Sulawesi Utara, Jawa Timur dan Bali dan selanjutnya diambil 1 kabupaten yang tertinggal dengan indikator IPM rendah. Hasilnya menujukkan pemerintah daerah kabupaten ada yang belum terpapar pemahaman bonus demografi, sedangkan di tingkat provinsi antar instansi belum mempunyai pemahaman yang sama tentang bonus demografi. Adanya kebijakan pusat dangan daerah yang belum serasi dan sinergis mengoptimalkan bonus demografi. Bonus demografi diiringi meningkatknya usaha mikro dan industri kecil sebagai upaya penciptaan kerja mandiri. Masyarakat belum menyadari adanya bonus demografi dan berharap peran pemerintah daerah untuk menyediakan fasilitas pelatihan keterampilan dan keahlian yang dapat diakses secara online.
Documentation of plant diversity of Southeast Asia: the new role of Belt and Road Initiative
Authors: Aung Mung Htoi , Li De Zhu , Tan Yun Hong , Xia Nian He , Quan Rui Chuan , Jin Xiao Hua
Published: January 2020

Editorial of special issue of plant diversity in southeastern Asia.
Character variation and taxonomy of short-tailed fruit bats from Carollia in Brazil
Authors: Lemos Túlio Henrique , da Cunha Tavares Valéria , Moras Ligiane Martins
Published: January 2020

Carolliahas a complex taxonomic history and is widely distributed in the Neotropics. Species ofCarolliaappear to have differentiated recently in the late Cenozoic, and present overlapping morphological characters that may not be useful to distinguish among species.Carolliahas recently been revised, but only a few specimens representing the Brazilian distribution ofCarolliawithin Brazil were studied. We reviewed specimens ofCarolliadistributed in several localities of Brazil revisiting previously described morphological characters for species identification, and taxonomic problems within the genus. We found a large degree of overlap between characters previously used to distinguish among species ofCarollia, and some of them constitute variation within a same species. We also report new records extending the known distribution ofC. benkeithito farther east of its previously known distribution (Parauapebas, southeastern Pará, and Vitória do Xingu, Pará, eastern Amazonian Brazil) and one record extending the distribution ofC. brevicaudasouth to Corumbá, Mato Grosso do Sul, Brazil.
Factors Affecting Organizational Effectiveness
Authors: Islam M. Zahidul , Said Thuraya Farhana , Sumardi Wardah Azimah , Rahman Safayet
Published: January 2020

This study aims to propose a conceptual framework of organizational effectiveness for Brunei's public sector. This study proposed knowledge sharing as a potential mediator for the relationship between organizational factors (organizational climate, structure and leadership) and organizational effectiveness. This study also proposed ICT as a potential moderator for the relationship between organizational factors and knowledge sharing. This study will help public sector managers to understand organizational effectiveness from a different perspective. Propositions of knowledge sharing as a potential mediator and ICT support as a potential moderator will provide public sector managers with guidance to ensure sustainable organizational effectiveness.
Maximizing Smartcard for Public Usage
Authors: Thani Fakhriyah Abdullah , Anshari Muhammad
Published: January 2020

With the rise of smart cards, it has utilized so that multiple applications can be built into the technology. This research aims to offer a multipurpose smart card as a solution for the duplicate smart card system. Using a mixed methods approach, one hundred samples were collected from the public. The data was analyzed using descriptive statistics. A Plan-Do-Check-Act (PDCA) assessment and a Root Cause Analysis (RCA) were used to analyze the collected data. The results indicated that the public views the current smart card system serves only a limited function and are open to the idea of a multipurpose smart card system. Recommendations are given to raise the awareness of the current smart card problem and to provide insight to better serve the public.
Video-Based Person Re-Identification With Unregulated Sequences
Authors: Huang Wenjun , Liang Chao , Xiao Chunxia , Han Zhen
Published: January 2020

Video-based person re-identification (re-id) has recently attracted widespread attentions because extra space-time information and more appearance cues in videos can be used to improve the performance of image-based person re-id. Most existing approaches equally treat person video images, ignoring their individual discrepancy. However, in real scenarios, captured images are usually contaminated by various noises, especially occlusions, resulting in a series of unregulated sequences. Through investigating the impact of unregulated sequences to feature representation of video-based person re-id, the authors find a remarkable promotion by eliminating noisy sub sequences. Based on this interesting finding, an adaptive unregulated sub sequence detection and refinement method is proposed to purify original video sequence and obtain a more effective and discriminative feature representation for video-based person re-id. Experimental results on two public datasets demonstrate that the proposed method outperforms the state-of-the-art work.
On Performance of Electrochemical Discharge Micro-Machining Process Using Different Electrolytes and Tool Shapes
Authors: Mallick Bijan , Biswas Sumit , Sarkar Biplab Ranjan , Doloi Biswanath , Bhattacharyya Bijoy
Published: January 2020

The electro-chemical discharge micro-machining (µ-ECDM) process can be utilised as a potential micro-machining process, which offers several advantages such as cost-effectiveness and diversity in applications on electrically non-conducting hard brittle materials like glass. The present research article includes the analysis of material removal rate (MRR), width of cut (WOC), heat affected zone (HAZ), and surface roughness (Ra) during µ-channeling on glass with a micro-ECDM process, considering applied voltage (V), electrolyte concentration (wt%), and tool shapes as process parameters. A comparative study is conducted to select the suitable tool shape and electrolyte. Moreover, the optical and SEM images are used to examine HAZ, WOC and topography of µ-channels. MRR and WOC enhance with the rise of applied voltage for fixed electrolyte concentration and vary with tool shape. Surface roughness (Ra) is found low at applied voltage of 55V and 60V for both electrolytes when straight and curved tools, respectively, are used. The straight tool shape is more suitable for µ-channeling on glass by µ-ECDM.
Teoria da Estruturação em estudos organizacionais: Análise da observação dos pressupostos
Authors: Valmorbida Sandra Mara Iesbik , Ensslin Sandra Rolim
Published: January 2020

A Teoria da Estruturação (TE), proposta por Giddens (1984) para análise da interação social entre agentes e estruturas sociais, tem sido utilizada nos estudos organizacionais. Este artigo teve por objetivo analisar os estudos organizacionais quanto à observação dos pressupostos-base da TE. Baseado no artigo de Rossoni, Guarido Filho e Coraiola (2013) que detalha os pressupostos de Giddens aplicados aos estudos organizacionais, esta pesquisa selecionou artigos empíricos para análise. Essa seleção foi informada pelo ProKnow-C, em 8 bases de dados, nas quais se encontraram 2.463 referências de artigos, filtradas por leitura dos títulos, reconhecimento científico, leitura dos resumos e integral do trabalho, resultando em 30 trabalhos que usaram a TE em estudos organizacionais. A análise desses artigos deu-se em função do tipo de trabalho, no qual o mais utilizado foi estudo de caso (80%). A maioria usou mais de uma fonte de dados (67%), sendo utilizadas entrevistas (70%), análise documental (57%) e observações (33%). Identificou-se que a maioria (90%) não leva em consideração todos os pressupostos associados à TE. Ao não fazer isso, os pesquisadores põem em risco a validade e confiabilidade dos resultados que podem causar problemas de interpretação.
Influência das características organizacionais na forma de distribuição da riqueza gerada
Authors: Mazzioni Sady , Moura Geovanne Dias de , Dal Magro Cristian Baú , Heberle Éder Luis , Fank Denise Rose Bracht , Roncalio Daniela
Published: January 2020

O objetivo do estudo consistiu em analisar a influência das características organizacionais na forma de distribuição da riqueza gerada aos agentes econômicos das empresas abertas listadas na B3. Para tal, realizou-se pesquisa descritiva, conduzida por meio de análise documental e abordagem quantitativa dos dados, referentes ao período de 2010 a 2016. A amostra da pesquisa foi composta por 1.785 observações de 253 companhias, com coleta manual dos dados em cada Demonstração do Valor Adicionado publicada pelas empresas no site da B3. Os resultados revelaram que o maior crescimento de vendas está associado com maior remuneração de capital próprio e menor remuneração de capital de terceiros; o maior endividamento está associado com maior remuneração de capital de terceiros; empresas maiores, com maior grau de intangibilidade e do setor de utilidade pública apresentaram menores níveis de remuneração aos empregados; empresas pertencentes ao Índice de Sustentabilidade Empresarial e do setor de utilidade pública remuneraram de forma mais elevada o governo. Os resultados permitem concluir que as características organizacionais exercem forte influência na forma de distribuição do valor adicionado produzido, contribuindo diferentemente com os acionistas, instituições financeiras, governo e empregados.
Sistemas de controle gerencial no setor público: a influência dos benefícios líquidos percebidos por contadores no desenho do sistema em prefeituras do Paraná
Authors: Defaveri Ivan Rafael , Baldissera Juliano Francisco , Dal Vesco Delci Grapegia
Published: January 2020

Os sistemas de controle gerencial (SCG) são um pacote de ferramentas e instrumentos tanto gerenciais como sociais, capazes de suportar as decisões dos gestores e alinhar as ações individuais com as metas da organização pública. O objetivo dessa pesquisa é verificar a influência da percepção geral dos benefícios líquidos do SCG no desenho dos sistemas de controle gerencial em prefeituras do Estado do Paraná. Para tanto, realizou-se uma pesquisa quantitativa através de questionários enviados aos contadores e controladores de prefeituras municipais que possibilitaram a análise através de testes descritivos e de frequência, assim como a regressão linear múltipla realizada. Os resultados sugerem que existe influência positiva dos benefícios líquidos no desenho de um SCG. Um usuário satisfeito com o sistema utilizado tende a escolher as características desejadas das informações que esse sistema gera. O uso diagnóstico e o uso disfuncional influenciam positivamente as técnicas de controle gerencial. Gestores e controladores públicos tendem a optar por técnicas de controle que lhes permitam monitorar o desempenho das instituições e também que lhes proporcionem vantagens e benefícios políticos. A contribuição do estudo é pelo fato de auxiliar na identificação de fatores capazes de influenciar o desenho dos sistemas de controle gerenciais em instituições públicas, e assim, melhorar a atuação dos gestores públicos.
Effect of Annealing Temperature on the Performance of ZnO Seed Layer for Photoanode in Photoelectrochemical Cells
Authors: Al-Zahrani Asla A. , Zainal Zulkarnain , Talib Zainal Abidin , Lim Hong Ngee , Fudzi Laimy Mohd , Holi Araa Mebdir , Mohd Ali Mahanim Sarif
Published: January 2020

Zinc oxide (ZnO) thin films were coated onto Indium Tin Oxide (ITO) glass substrate using spin coating technique as a function of annealing temperature. The thin film preparation was undertaken by utilising zinc acetate dihydrate, ethanol and diethanolamine as the precursors. The films were coated at room temperature prior to being annealed at temperatures ranging from 300 °C to 450 °C. The resulting crystalline structure and surface morphology of the thin films were then examined using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). UV-visible spectrophotometer was also used to record the optical absorbance in wavelengths ranging from 200 to 800 nm. The findings revealed that the ZnO thin films showed a single phase of wurtzite with n-type semiconductor, with the lowest value of band gap energy of 3.28 eV for ZnO thin films annealed at 350 °C. FESEM results showed that the ZnO nanoparticles were very compact on the surface, whereby the average particle size was equivalent to 108.5, 115.3, 108.2 and 107.8 nm at the temperatures 300 °C, 350 °C, 400 °C, and 450 °C, respectively. Additionally, the highest photoconversion efficiency (0.11%) recorded for the sample was annealed at 350◦C. Thus, annealing temperature was found to significantly affect the optical and electrical properties of ZnO nanoparticle seed layer, as well as its band gap energy and surface morphology.
Optical Investigations of Nanophotonic LiNbO3 Films Deposited by Pulsed Laser Deposition Method
Authors: Taleb Sarah M. , Fakhri Makram A. , Adnan Salah Aldeen
Published: January 2020

The nanocrystalline structure of Lithium niobate (LiNbO3) was prepared and deposited onto substrate made of quartz by utilize pulse laser deposition technique. The effect of substrate temperature on the structural, optical and morphological properties of lithium niobate photonic film grown was studied. The chemical mixture was prepared by mixing the raw material (Li2CO3, Nb2O5) with Ethanol liquid without any further purification, at time of stirrer 3hrs but without heating, then annealing process the formed material at 1000C° for 4hrs. We characterized and analyzed the LiNbO3 nanostructure thin films by utilize Ultra-Violet Visible (UV-vis). The UV-vis measurements show that, when the substrate temperature increases, the values of transmission, absorption and energy band gap will decreased, but the values of reflection and refractive index will increased. That means the LiNbO3 thin film prepared at substrate temperatures 300C° give the best result for manufacture the optical waveguide.
Study the Effects of Shari Lake on the Physical and Chemical Properties for Groundwater in Samarra City
Authors: Theyab Mustafa A. , Al-Hilali Baraa M. Ibrahim , Fadhil Mohammed A.
Published: January 2020

We design hydro geochemical study to show the effect of Shari Lake on Samarra groundwater. tow samples (Jelam 1,Jelam 2 ) that nearby Shari lake and other samples taken from different location from Samarra city ( Efraz ,SDI factory , Golden Mosque, Samarra university ). Then sent samples to specific laboratory for chemical and microbial test .the result shows the locations (Jelame 1, Jelame 2) have highest value in PH, but SDI factory location has highest value in Sulfate. The result show affect ground water in this city by salt and mineral that found in watershed and ground structure specially limestone that flow throw ground that lead to dissolve salt and mineral then arise the value of studied data.
Drying of Ceramic Bricks: Thermal and Mass Analysis via CFD
Authors: Santos R.S. , de Farias Neto Severino Rodrigues , Barbosa de Lima A.G. , Silva Júnior J.B. , da Silva Anderson Melchiades Vasconcelos
Published: January 2020

Several studies about drying of ceramic materials have been developed in many engineering and fabrication sectors. This process requires high investments and high energy consumption, resulting in high costs to the companies of this sector. In many situations, it is common the use of theoretical solutions that allow, with relative ease and low cost, to change the operational and geometrical conditions of the dryer or object of drying, to obtain the optimized operational conditions. In this sense, this work aims to predict the drying process of a ceramic brick in an oven using the computational fluid dynamics analysis. For a drying temperature of 80°C, the results of the drying and heating kinetics, and the moisture content and temperature distributions of the product and the air and the air velocity and pressure in the oven are shown and analyzed. A comparison between the predicted and experimental data of the average moisture content and temperature of the brick along the process was done and a good agreement was obtained.
Drying of Oblate Spheroidal Solids via Model Based on the Non-Equilibrium Thermodynamics
Authors: Soares de Melo J.C. , Soares Gomez Ricardo , Silva Júnior J.B. , de Queiroga A.X. Mesquita , Lima Dantas R. , Barbosa de Lima A.G. , Pereira Silva Wilton
Published: January 2020

Food drying is one of the most used methods of preservation. To accurately describe moisture migration within biological products (grains, fruits, vegetables, etc.) during drying and explain the effects of this process on the quality of the material, have been proposed several mathematical models, but few incorporate the phenomena of simultaneous heat and mass transport applied to complex geometry. In this sense, this paper aims to present a mathematical model, based on the thermodynamics of irreversible processes to describe the heat and mass transfer (liquid and vapor) during the drying of bodies with oblate spheroidal geometry. This model was applied to describe drying of lentil, considering the variables transport coefficients and equilibrium conditions at the surface of the solid. Results of the average moisture content, average temperature, liquid flux, vapor flux, and moisture content and temperature distributions inside a lentil kernel during drying process, at different temperatures (40 and 60 oC) were presented and analyzed.
Osmotic Dehydration of Cassava Cubes: Kinetic Analysis and Optimization
Authors: Pessoa Thayze Rodrigues Bezerra , Barbosa de Lima A.G. , Martins Pierre Correa , Pereira V. Campos , Silva do Carmo A. , da Silva E.
Published: January 2020

The present work had the objective of studying the osmotic dehydration process of cassava cubes (ManihotesculentaCrantz.) in ternary solutions containing water, sucrose, and sodium chloride. The osmotic dehydration process was studied by using a 24 factorial planning with central points at different conditions of temperature (19-63°C), solute concentration (23-67% w/w), operating time (70-190 min.) and NaCl concentration (0-20% w/w). The process optimization was verified through the performance ratio of minimum solids gain, in conjunction with the maximum moisture loss and reduction of water activity of the material. From the analysis, the optimum condition for osmotic dehydration of cassava cubes was temperature52°C, concentration of the osmotic solution 56%solute,10% NaCl concentration,160 minutes of immersion time and 180 rpm . The study of osmotic dehydration kinetics in the optimized condition showed that the moisture loss reached equilibrium in 180 minutes and the solids gain in 30 minutes. The model of Azuara and contributors was fitted to experimental data of moisture lost and total solids gain, in the optimal condition and good agreement were obtained. From this comparison, the average effective diffusivity coefficients of moisture (1.99x10-8m2/s) and total solids (2.77x10-8m2/s) were estimated.
Sepsis in the Context of Nonventilator Hospital-Acquired Pneumonia
Authors: Giuliano Karen K. , Baker Dian
Published: January 2020

Background

Sepsis is a leading cause of mortality among hospitalized patients and is the most expensive condition affecting the US health care system. Pneumonia is associated with about half of sepsis cases, yet limited research has described the incidence of sepsis in the context of nonventilator hospital-acquired pneumonia (NV-HAP). Persons with NV-HAP who are at risk for sepsis must be identified so that interventions to reduce the burden of NV-HAP and improve outcomes among patients with sepsis can be designed.

Objective

To determine the proportion of persons with NV-HAP in whom sepsis develops and to describe the demographic and clinical characteristics of persons with NV-HAP in whom sepsis develops.

Methods

In this retrospective, population-based study, data were extracted from the National Inpatient Sample from the 2012 Healthcare Cost and Utilization Project dataset. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify adult patients at least 18 years of age who had a stay of at least 48 hours, had no documented diagnosis of ventilator-associated pneumonia, and had secondary diagnoses of both NV-HAP and sepsis, neither of which was present on admission.

Results

In the 2012 calendar year, 119 075 adults had NV-HAP develop; sepsis developed in 36.3% of these cases. Male and black patients were overrepresented in the sample, and patients had a mean of 7 comorbid conditions (SD, 3.3).

Conclusions

Sepsis in the context of NV-HAP is a key concern. Additional research is needed to identify factors associated with the development of sepsis among patients with NV-HAP.
Cutting Edge: IL-6–Driven Immune Dysregulation Is Strictly Dependent on IL-6R α-Chain Expression
Authors: Mufazalov Ilgiz A. , Andruszewski David , Schelmbauer Carsten , Heink Sylvia , Blanfeld Michaela , Masri Joumana , Tang Yilang , Schüler Rebecca , Eich Christina , Wunderlich F. Thomas , Karbach Susanne H. , Bluestone Jeffrey A. , Korn Thomas , Waisman Ari
Published: January 2020

IL-6 binds to the IL-6R α-chain (IL-6Rα) and signals via the signal transducer gp130. Recently, IL-6 was found to also bind to the cell surface glycoprotein CD5, which would then engage gp130 in the absence of IL-6Rα. However, the biological relevance of this alternative pathway is under debate. In this study, we developed a mouse model, in which murine IL-6 is overexpressed in a CD11c-Cre–dependent manner. Transgenic mice developed a lethal immune dysregulation syndrome with increased numbers of Ly-6G+ neutrophils and Ly-6Chi monocytes/macrophages. IL-6 overexpression promoted activation of CD4+ T cells while suppressing CD5+ B-1a cell development. However, additional ablation of IL-6Rα protected IL-6–overexpressing mice from IL-6–triggered inflammation and fully phenocopied IL-6Rα–deficient mice without IL-6 overexpression. Mechanistically, IL-6Rα deficiency completely prevented downstream activation of STAT3 in response to IL-6. Altogether, our data clarify that IL-6Rα is the only biologically relevant receptor for IL-6 in mice.
CREER, EXPERIMENTAR, COMPRENDER: UNA REFLEXIÓN SOBRE LA INTERSUBJETIVIDAD A PROPÓSITO DE UNA EXPERIENCIA DE INTERVENCIÓN EN EL CAMPO DE LA CREENCIA
Authors: Aburto Héctor Zapata
Published: January 2020

El siguiente articulo propone una reflexión  sobre  la dinámica intersubjetiva dada entre un investigador y su campo, teniendo como marco de estudio la creencia, en lo particular la que refiere a la espiritualidad New Age. La pregunta primordial que delinea tal reflexión y que surge a partir de una experiencia de campo es: ¿Qué lugar juega y a qué problematizaciones lleva  la creencia de un investigador  una vez que decide aventurarse a estudiar la creencia de otros? Así pues, mi punto de partida para responder esta pregunta, es una narrativa de campo que intercala apuntes teórico-metodológicos que a su vez intentan poner en discusión algunos de los postulados de autores pertenecientes a la antropología posmoderna (particularmente me centraré en Clifford Geertz y James Clifford)  y de otros que intentaron pensar el campo de la creencia.
Fit for high altitude: are hypoxic challenge tests useful?
Authors: Matthys Heinrich
Published: January 2020

Altitude travel results in acute variations of barometric pres- sure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax), sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pres- sure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symp- toms of emotional hyperventilation. In patients with pre- existing respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea) an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and sys- temic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient.

Instead of the hypoxia altitude simulation test (HAST), which is not without danger for patients with respiratory insuffi- ciency, we prefer primarily a hyperoxic challenge. The supple- mentation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduc- tion of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supple- mental O2-breathing remains the gold standard. The increas- ing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil) or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists) including mechanical aids to reduce periodical or insufficient ventilation during altitude exposure (added dead space, continuous or bilevel positive airway pressure, non-invasive ventilation) call for further randomized controlled trials of combined applications.
Time for physicians to be aware of molecular genetic testing
Authors: Nardini Cecilia
Published: January 2020

In the last few years there has been growing excite- ment about the ‘molecular revolution’ that seems to offer both a promise and a threat at the same time. As more and more diseases are shown by research to be linked to a genetic cause, the field of preven- tion will potentially be revolutionized: genetic re- search has highlighted the fact that the conditions depending on the genetic makeup of a person [...]
Trends in adult asthma hospitalization: gender-age effect
Authors: Gonzalez-Barcala Francisco J. , Aboal Jorge , Valdes Luis , Carreira José M. , Alvarez-Dobaño José M. , Puga Amalia , Garcia-Sanz María Teresa , Takkouche Bahi
Published: January 2020

Background: Hospital admissions due to asthma are a reliable source of information on the morbidity of the disease which, after the increase observed in the last quarter of the last centu- ry, shows a declining trend in the last few years. The aim of this study was to look at hospital admission trends due to asthma in our community and analyze some of its associated factors.

Methods: Retrospective analysis of all hospital admissions involving adults aged 15 years and older with asthma as the primary or secondary diagnosis (if the first diagnosis was res- piratory failure or respiratory infection) in Public Health Service hospitals in the Galician region of Spain between the years 1995-2009 (total 24,766 admissions).

Results: The majority of patients admitted were female (71%), over 60 years of age (64%), and admission occurred predomi- nantly in the winter months. The hospitalization rate due to asthma tripled over the period studied, this being mainly accounted for by women aged over 60 years. Mean hospital stay was 9.2 days, longer in older patients or those admitted over the weekend.

Conclusions: A significant increase in hospital admissions due to asthma over the last few years has been observed in our community, mainly involving older women. The mean stay seems long, increasing with patients’ age and admission over the weekend.
Kidney pulmonary hypertension: another road on the map?
Authors: Sofia Matteo , Stanziola Anna A.
Published: January 2020

Pulmonary hypertension (PH) is a serious disorder that worsens the course of chronic heart, lung or systemic diseases. However the need to discrimi- nate PH, a pathophysiological condition, from pul- monary arterial hypertension [...]
Effects of volatile substance abuse on the respiratory system in adolescents
Authors: Büker Halime S.C. , Demir Esen , Yüncü Zeki , Gülen Figen , Midyat Levent , Tanaç Remziye
Published: January 2020

Aim: Inhalant abuse is a prevalent and often overlooked form of substance abuse in adolescents. Chronic inhalant abuse can damage respiratory, cardiac, renal, hepatic, and neurolog- ic systems. This study aims to determine the physiologic effects of inhaling solvents on the respiratory functions.

Methods: The general health status of the subjects was assessed by history taking, physical examination and a questionnaire which was designed to show the severity of respiratory symp- toms. Spirometry, ventilation/perfusion scintigraphy, and high resolution computed tomography (HRCT) were performed to assess pulmonary functions and anatomy.

Results: Thirty-one male volatile substance abusers and 19 control subjects were included in the study. The mean age of onset of inhalant use was 14.6 ± 2.2 (9-18) years and dura- tion of drug use was 3.7 ± 1.7 years. The most common respi- ratory symptoms in volatile substance abusers were nasal congestion (45.2%), sputum (38.7%), exercise intolerance (32.3%) and cough (22.6%). Results of spirometric studies showed 12 (41.4%) subjects with low FVC values < 80% of predicted, indicative of restrictive ventilatory pattern in the study group. Although the difference was not statistically sig- nificant, restrictive ventilatory pattern was higher in the study group. There was no statistically significant correlation between restrictive ventilatory pattern and the age of onset/duration/frequency of inhalant abuse, respiratory symptoms and scintigraphic abnormalities. Subjects who had restrictive pattern in their pulmonary function tests were more likely to have abnormal findings at HRCT (p < 0.01).

Conclusion: This study has shown a positive correlation between volatile substance abuse and the development of restrictive ventilatory pattern, but more comprehensive stud- ies are needed for more precise conclusions.
Does the asthma control test reflect inflammation?
Authors: Neri Margherita
Published: January 2020

The present issue of Multidisciplinary Respiratory Medicine includes a paper by Bora et al. [1] investigating the relationship between the asthma control test (ACT) and airway inflammation. In a group of stable asthmatic patients admitted to a pulmonary outpatient clinic, the authors carried out the ACT, pulmonary function tests, methacholine bronchial provocation test (MBPT), fractional exhaled nitric oxide level (FeNO), and induced sputum test. [...]
Clinical analysis of 68 patients with pulmonary mycosis in China
Authors: Luo Bai-ling , Zhang Le-meng , Hu Cheng-ping , Xiong Zeng
Published: January 2020

Background: Due to the lack of specific clinical manifestations and imaging features, the diagnosis of pulmonary mycosis is difficult. This study aimed to investigate the pathogens, clinical manifestations, imaging features, diagnosis and management of pulmonary mycosis.

Methods: Data on 68 patients diagnosed as pulmonary mycosis in Xiang Ya hospital from January 2001 to December 2010 were collected and their clinical manifestations, radiographic characterization, diagnostic methods and management were analyzed.

Results: All patients were diagnosed by pathological examination. Of the 68 cases, 38 (55.9%) had pulmonary aspergillosis and 19 (27.9%) pulmonary cryptococcosis. Open-lung surgery was performed in 38 patients (55.9%), transbronchial biopsy in 15 (22.0%), and computerized tomography (CT)-guided percutaneous needle biopsy in 11 (16.2%). Main symptoms were as follows: cough in 51 cases (75.0%), expectoration in 38 (55.9%), hemoptysis in 25 (37.8%), fever in 20 (29.4%), while 6 cases (11.1%) were asymptomatic. X-ray and chest CT showed masses or nodular lesions in 52 cases (76.5%), patchy lesions in 10 (14.7%), cavity formation in 15 (22.0%), and diffuse miliary nodules in 1 case. In 51 cases (75.0%) misdiagnosis before pathological examination occurred. Surgical resection was performed in 38 patients (55.9%). In 25 patients (36.7%) systemic antifungal therapy was administered, and 20 patients (29.4%) experienced complete responses or partial responses.

Conclusion: The main pathogens of pulmonary mycosis are Aspergillus, followed by cryptococcosis. Final diagnosis of pulmonary mycosis mainly depends on pathological examination. The clinical manifestations, imaging features, diagnostic methods and management differ depending on the pathogens. Satisfactory therapy can be obtained by both antifungal and surgical treatment.
Effect of radiological extent and severity of bronchiectasis on pulmonary function
Authors: Habesoglu Mehmet A. , Tercan Fahri , Ozkan Ugur , Eyuboglu Fusun O.
Published: January 2020

Background: The aim of this study was to ascertain the effect of the extent and severity of bronchiectasis as determined with high-resolution computed tomography (HRCT) on lung function in patients with pure bronchiectasis, bronchiectasis and asthma, and bronchiectasis and chronic obstructive pulmonary disease (COPD).

Methods: One hundred nineteen patients (71 with pure bronchiectasis, 25 asthmatic patients with bronchiectasis, and 23 COPD patients with bronchiectasis) underwent HRCT and pulmonary function tests. Computed tomography features were scored by the consensus of 2 radiologists.

Results: There were no statistically significant differences among the 3 patient groups regarding the extent of bronchiectasis, bronchial dilatation degree, bronchial wall thickening, decreased attenuation in the lung parenchyma, or presence of mucus in the large and small airways. In the pure bronchiectasis group, a negative correlation was found between forced vital capacity (FVC) % of predicted, forced expiratory volume in 1 sec (FEV1) % of predicted, the FEV1/FVC ratio and the extent of bronchiectasis, bronchial wall thickening, bronchial wall dilatation, and decreased attenuation. At multivariate analysis the main morphologic changes associated with impairment of FVC and FEV1 were the extent of bronchiectasis and a decreased attenuation in the lung parenchyma. The decrease in the FEV1/FVC ratio was associated with bronchial wall dilatation. No correlation was found between morphologic changes and indices of pulmonary function in the asthma and COPD patients.

Conclusions: Morphologic changes associated with bronchiectasis do not influence lung function in patients with asthma and COPD directly, although they do play a role in impairing pulmonary function in patients with bronchiectasis alone.
Cervical necrotizing fasciitis associated with descending necrotizing mediastinitis
Authors: Gonlugur Ugur , Guclu Oguz , Karatag Ozan , Mirici Arzu , Derekoy Sefa
Published: January 2020

We report a case of potentially fatal cervical necrotizing fasciitis and descending necrotizing mediastinitis due to deep neck infection in a 66-year-old male patient with no history or evidence of immunocompromising disorders. On admission, he had painful neck movements and the skin over his neck was red, hot and tender. A computerized tomography (CT) scan of his neck and chest showed evidence of air collection in soft tissues. He was treated with broad-spectrum intravenous antibiotics and early massive cervical drainage. Prompt diagnosis by CT of the neck and chest enabled an early surgical treatment of cervical necrotizing fasciitis. Although acute mediastinitis is a fatal infection involving the connective tissues that fill the interpleural spaces and surround the median thoracic organs, an extensive cervicotomy combined with appropriate antibiotics can prevent the need for mediastinal drainage.