bluuebunny/crossref_metadata_2025 huggingface dataset:
The Generalized Connectivity of Data Center Networks
Authors: Hao Chen , Yang Weihua
Published: August 2019

The generalized [Formula: see text]-connectivity of a graph [Formula: see text] is a parameter that can measure the reliability of a network [Formula: see text] to connect any [Formula: see text] vertices in [Formula: see text], which is a generalization of traditional connectivity. Let [Formula: see text] and [Formula: see text] denote the maximum number [Formula: see text] of edge-disjoint trees [Formula: see text] in [Formula: see text] such that [Formula: see text] for any [Formula: see text] and [Formula: see text]. For an integer [Formula: see text] with [Formula: see text], the generalized [Formula: see text]-connectivity of a graph [Formula: see text] is defined as [Formula: see text] and [Formula: see text]. Data centers are essential to the business of companies such as Google, Amazon, Facebook and Microsoft et al. Based on data centers, the data center networks [Formula: see text], introduced by Guo et al. in 2008, have many desirable properties. In this paper, we study the generalized [Formula: see text]-connectivity of [Formula: see text] and show that [Formula: see text] for [Formula: see text] and [Formula: see text].
Detecting and Predicting Tipping Points
Authors: Peng Xiaoyi , Small Michael , Zhao Yi , Moore Jack Murdoch
Published: August 2019

Tipping points are sudden, and sometimes irreversible and catastrophic, changes in a system’s dynamical regime. Complex networks are now widely used in the analysis of time series from a complex system. In this paper, we investigate the scope of network methods to indicate tipping points. In particular, we verify that the permutation entropy of transition networks constructed from time series observations of the logistic map can distinguish periodic and chaotic regimes and indicate bifurcations. The permutation entropy of transition networks, the mean edge betweenness of visibility graphs and the number of code words in compression networks, are each shown to indicate the onset of transition of a pitchfork bifurcation system. Our study shows that network methods are effective in detecting transitions. Network-based forecasts can be applied to models of real systems, as we illustrate by considering a lake eutrophication model.
Complex Dynamics of an Impulsive Chemostat Model
Authors: Yang Jin , Tan Yuanshun , Cheke Robert A.
Published: August 2019

We propose a novel impulsive chemostat model with the substrate concentration as the basis for the implementation of control strategies, and then investigate the model’s global dynamics. The exact domains of the impulsive and phase sets are discussed in the light of phase portraits of the model, and then we define the Poincaré map and study its complex properties. Furthermore, the existence and stability of the microorganism eradication periodic solution are addressed, and the analysis of a transcritical bifurcation reveals that an order-1 periodic solution is generated. We also provide the conditions for the global stability of an order-1 periodic solution and show the existence of order-[Formula: see text] [Formula: see text] periodic solutions. Moreover, the PRCC results and bifurcation analyses not only substantiate our results, but also indicate that the proposed system exists with complex dynamics. Finally, biological implications related to the theoretical results are discussed.
Cryptanalysis and Improvement of a Color Image Encryption Scheme Based on DNA Sequences and Multiple 1D Chaotic Maps
Authors: Panwar Kirtee , Purwar Ravindra Kumar , Jain Anchal
Published: August 2019

This paper presents cryptanalysis of a color image encryption scheme. DNA encoding and multiple 1D chaotic maps are used in the encryption process which increases its computational speed. The key streams generated in this scheme are dependent on secret keys, updated using the sum of pixel intensities of plain image of size [Formula: see text]. This paper analyzes the security of encryption scheme against the chosen plaintext attack and finds that only [Formula: see text] different key matrices for diffusion are possible, an equivalent version of which can be revealed with [Formula: see text] chosen plain images. Experimental results are presented to prove that equivalent diffusion keys and block permutation sequence can be effectively revealed through the attack. In addition, low sensitivity of keys towards changes in plaintext along with insecure diffusion process involved in encryption process is also reported. Finally, to remedy the shortcomings of the original encryption scheme, an enhanced encryption scheme is generated that can resist chosen/known plaintext attack while maintaining the merits of the original encryption scheme.
Automatic Detection of Saddle-Node–Transcritical Interactions
Authors: van Veen Lennaert , Hoti Marvin
Published: August 2019

Dynamical systems with special structure can exhibit transcritical bifurcations of codimension one. In such systems, the interactions of transcritical bifurcations of codimension two can act as organizing centers. We consider saddle-node–transcritical interactions with either one or two zero eigenvalues and show that, using default test functions, the widely used continuation packages MatCont and AUTO classify these interactions as cusp and Bogdanov–Takens bifurcations, respectively. We propose a new test function that distinguishes these singularities and demonstrate its use in the analysis of a predator–prey-nutrient model strained by a toxicant. The details of the implementation are provided, along with test codes for MatCont.
Stochastic Resonance and Bifurcation of Order Parameter in a Coupled System of Underdamped Duffing Oscillators
Authors: Liu Ruonan , Kang Yanmei , Fu Yuxuan , Chen Guanrong
Published: August 2019

The long-term mean-field dynamics of coupled underdamped Duffing oscillators driven by an external periodic signal with Gaussian noise is investigated. A Boltzmann-type [Formula: see text]-theorem is proved for the associated nonlinear Fokker–Planck equation to ensure that the system can always be relaxed to one of the stationary states as time is long enough. Based on a general framework of the linear response theory, the linear dynamical susceptibility of the system order parameter is explicitly deduced. With the spectral amplification factor as a quantifying index, calculation by the method of moments discloses that both mono-peak and double-peak resonance might appear, and that noise can greatly signify the peak of the resonance curve of the coupled underdamped system as compared with a single-element bistable system. Then, with the input signals taken from laboratory experiments, further observations show that the mean-field coupled stochastic resonance system can amplify the periodic input signal. Also, it reveals that for some driving frequencies, the optimal stochastic resonance parameter and the critical bifurcation parameter have a close relationship. Moreover, it is found that the damping coefficient can also give rise to nontrivial nonmonotonic behaviors of the resonance curve, and the resultant resonant peak attains its maximal height if the noise intensity or the coupling strength takes the critical value. The new findings reveal the role of the order parameter in a coupled system of chaotic oscillators.
Artificial Intelligence in Psychomotor Learning: Modeling Human Motion from Inertial Sensor Data
Authors: Santos Olga C.
Published: August 2019

Recent trends in educational technology focus on designing systems that can support students while learning complex psychomotor skills, such as those required when practicing sports and martial arts, dancing or playing a musical instrument. In this context, artificial intelligence can be key to personalize the development of these psychomotor skills by enabling the provision of effective feedback when the instructor is not present, or scaling up to a larger pool of students the feedback that an instructor would typically provide one-on-one. This paper presents the modeling of human motion gathered with inertial sensors aimed to offer a personalized support to students when learning complex psychomotor skills. In particular, when comparing learner data with those of an expert during the psychomotor learning process, artificial intelligence algorithms can allow to: (i) recognize specific motion learning units and (ii) assess learning performance in a motion unit. However, it seems that this field is still emerging, since when reviewed systematically, search results hardly included the motion modeling with artificial intelligence techniques of complex human activities measured with inertial sensors.
Synthesis of Au@MoS2-CdS Ternary Composite Structure with Enhanced Photocatalytic Activity
Authors: Liu Zhe , Wang Liwei , Li Ruoping , Huang Mingju
Published: August 2019

Au@MoS2-CdS, as ternary composite structure, was successfully synthesized by a facile process combining hydrothermal and seed-growth methods. The introduction of Au nanoparticles (NPs) into MoS2 spheres, forming a core–shell structure, demonstrates strong plasmonic absorption enhancement. The incorporation of CdS NPs into the Au@MoS2 core–shell structure further extends the absorption range of visible light and enhances exciton dissociation. The resultant composite structure exhibits the highest photocatalytic activity in photocatalytic degradation of rhodamine B (RhB) solution, compared with Au NPs, MoS2 spheres, Au@MoS2 core–shell and MoS2-CdS heterostructures. The above phenomena are supported by a series of characterization results such as SEM, TEM, XRD, EDS and UV-Vis, etc. Based on structural and morphological analyses, we propose the synthesis method of ternary composite structure photocatalysts, which is helpful for the synthesis of future multicomponent photocatalytic materials.
Overexpressed microRNA-136 works as a cancer suppressor in gallbladder cancer through suppression of JNK signaling pathway via inhibition of MAP2K4
Authors: Niu Jixiang , Li Zhen , Li Fuzhou
Published: August 2019

In recent studies, microRNAs (miRs) have been widely explored as important regulators in tumor suppression. miR-136 has been suggested to participate in tumor inhibition through control of vital cellular processes, such as angiogenesis, proliferation, and apoptosis. This study aimed to evaluate the effects of overexpressed miR-136 by transferring mimics in gallbladder cancer (GBC) and to assess the functional role of miR-136 in GBC cell behaviors with the involvement of the mitogen-activated protein kinase kinase 4 ( MAP2K4)-dependent JNK signaling pathway. Differentially expressed miRs associated with GBC were screened using microarray expression profiles, which identified that miR-136 expression was decreased in GBC. Furthermore, MAP2K4 was validated as a target gene of miR-136. To uncover functional relevance regarding miR-136 and MAP2K4 in GBC, cultured GBC cell lines were prepared to transfect with mimic, inhibitor, siRNA, or vectors. At the same time, the transfected GBC cells were inoculated into nude mice to validate findings in vivo. The obtained results demonstrated that overexpressed miR-136 inhibited angiogenesis and cell proliferation and promoted apoptosis in GBC cell lines in vitro, accompanied by impeded cellular tumorigenicity in nude mice via the suppression of MAP2K4. Moreover, the overexpression of MAP2K4 and the activation of the JNK signaling pathway reversed the inhibitory effects of miR-136 on the angiogenesis and tumorigenicity of GBC cells. Together, our results indicated that overexpressed miR-136 attenuates angiogenesis and enhances cell apoptosis in GBC via the JNK signaling pathway by downregulating the expression of MAP2K4.

NEW & NOTEWORTHY This study is based on previous studies suggesting the tumor-suppressive role of microRNA (miR)-136 in various cancers. We aim to clarify whether miR-136 could function as a tumor suppressor in gallbladder cancer (GBC) and an underlying mechanism. In vitro and in vivo assays delineated that the tumor-suppressive role of miR-136 in GBC is achieved through inactivation of the JNK signaling pathway by downregulation of MAP2K4.
Tamoxifen-induced, intestinal-specific deletion of Slc5a6 in adult mice leads to spontaneous inflammation: involvement of NF-κB, NLRP3, and gut microbiota
Authors: Sabui Subrata , Skupsky Jonathan , Kapadia Rubina , Cogburn Kyle , Lambrecht Nils W. , Agrawal Anshu , Said Hamid M.
Published: August 2019

The sodium-dependent multivitamin transporter (SMVT; SLC5A6) is involved in intestinal absorption of vitamin B7 (biotin). We have previously shown that mice with an embryonic intestinal-specific SMVT knockout (KO) develop biotin deficiency and severe spontaneous intestinal inflammation in addition to growth retardation, developmental delays, and death within the first 6–7 wk of life. The profound morbidity and mortality associated with the SMVT-KO has limited our ability to further characterize the intestinal inflammation and other sequelae of this deletion in adult mice with a mature gut microbiota. To overcome this limitation, we generated an intestine-specific, tamoxifen-inducible, conditional SMVT-KO (SMVT-icKO). Our results showed that adult SMVT-icKO mice have reduced body weight, biotin deficiency, shorter colonic length, and bloody diarrhea compared with age- and sex-matched control littermates. All SMVT-icKO mice also developed spontaneous intestinal inflammation associated with induction of calprotectin (S100a8/S100a9), proinflammatory cytokines (IL-1β, TNF-α, IFN-γ, and IL-6), and an increase in intestinal permeability. Additionally, the intestines of SMVT-icKO showed activation of the NF-κB pathway and the nucleotide-binding domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome. Notably, administration of broad-spectrum antibiotics reduced lethality and led to normalization of intestinal inflammation, proinflammatory cytokines, altered mucosal integrity, and reduced expression of the NLRP3 inflammasome. Overall, these findings support our conclusion that the biotin transport pathway plays an important role in the maintenance of intestinal homeostasis, and that NF-κB and the NLRP3 inflammasome, as well as gut microbiota, drive the development of intestinal inflammation when SMVT is absent.

NEW & NOTEWORTHY This study demonstrates that deletion of the intestinal biotin uptake system in adult mice leads to the development of spontaneous gut inflammation and that luminal microbiota plays a role in its development.
Protein arginine methyltransferase biology in humans during acute and chronic skeletal muscle plasticity
Authors: vanLieshout Tiffany L. , Bonafiglia Jacob T. , Gurd Brendon J. , Ljubicic Vladimir
Published: August 2019

Protein arginine methyltransferases (PRMTs) are a family of enzymes that catalyze the methylation of arginine residues on target proteins. While dysregulation of PRMTs has been documented in a number of the most prevalent diseases, our understanding of PRMT biology in human skeletal muscle is limited. This study served to address this knowledge gap by exploring PRMT expression and function in human skeletal muscle in vivo and characterizing PRMT biology in response to acute and chronic stimuli for muscle plasticity. Fourteen untrained, healthy men performed one session of sprint interval exercise (SIE) before completing four bouts of SIE per week for 6 wk as part of a sprint interval training (SIT) program. Throughout this time course, multiple muscle biopsies were collected. We found that at basal, resting conditions PRMT1, PRMT4, PRMT5, and PRMT7 were the most abundantly expressed PRMT mRNAs in human quadriceps muscle. Additionally, the broad subcellular distribution pattern of PRMTs suggests methyltransferase activity throughout human myofibers. A spectrum of PRMT-specific inductions, and decrements, in expression and activity were observed in response to acute and chronic cues for muscle plasticity. In conclusion, our findings demonstrate that PRMTs are present and active in human skeletal muscle in vivo and that there are distinct, enzyme-specific responses and adaptations in PRMT biology to acute and chronic stimuli for muscle plasticity. This work advances our understanding of this critical family of enzymes in humans.

NEW & NOTEWORTHY This is the first report of protein arginine methyltransferase (PRMT) biology in human skeletal muscle in vivo. We observed that PRMT1, -4, -5, and -7 were the most abundant PRMT mRNAs in human muscle and that PRMT proteins exhibited a broad subcellular localization that included myonuclear, cytosolic, and sarcolemmal compartments. Acute exercise and chronic training evoked PRMT-specific alterations in expression and activity. This study reveals a hitherto unknown complexity to PRMT biology in human muscle.
Placental oxygen transfer reduces hypoxia-reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea
Authors: Almendros Isaac , Martínez-Ros Paula , Farré Nuria , Rubio-Zaragoza Mónica , Torres Marta , Gutiérrez-Bautista Álvaro J. , Carrillo-Poveda José M. , Sopena-Juncosa Joaquín J. , Gozal David , Gonzalez-Bulnes Antonio , Farré Ramon
Published: August 2019

Obstructive sleep apnea (OSA), characterized by events of hypoxia-reoxygenation, is highly prevalent in pregnancy, negatively affecting the gestation process and particularly the fetus. Whether the consequences of OSA for the fetus and offspring are mainly caused by systemic alterations in the mother or by a direct effect of intermittent hypoxia in the fetus is unknown. In fact, how apnea-induced hypoxemic swings in OSA are transmitted across the placenta remains to be investigated. The aim of this study was to test the hypothesis, based on a theoretical background on the damping effect of oxygen transfer in the placenta, that oxygen partial pressure (Po2) swings resulting from obstructive apneas mimicking OSA are mitigated in the fetal circulation. To this end, four anesthetized ewes close to term pregnancy were subjected to obstructive apneas consisting of 25-s airway obstructions. Real-time Po2 was measured in the maternal carotid artery and in the umbilical vein with fast-response fiber-optic oxygen sensors. The amplitudes of Po2 swings in the umbilical vein were considerably smaller [3.1 ± 1.0 vs. 21.0 ± 6.1 mmHg (mean ± SE); P < 0.05]. Corresponding estimated swings in fetal and maternal oxyhemoglobin saturation tracked Po2 swings. This study provides novel insights into fetal oxygenation in a model of gestational OSA and highlights the importance of further understanding the impact of sleep-disordered breathing on fetal and offspring development.

NEW & NOTEWORTHY This study in an airway obstruction sheep model of gestational sleep apnea provides novel data on how swings in oxygen partial pressure (Po2) translate from maternal to fetal blood. Real-time simultaneous measurement of Po2 in maternal artery and in umbilical vein shows that placenta transfer attenuates the magnitude of oxygenation swings. These data prompt further investigation of the extent to which maternal apneas could induce similar direct oxidative stress in fetal and maternal tissues.
Motor unit discharge rate and the estimated synaptic input to the vasti muscles is higher in open compared with closed kinetic chain exercise
Authors: Boccia Gennaro , Martinez-Valdes Eduardo , Negro Francesco , Rainoldi Alberto , Falla Deborah
Published: August 2019

Conflicting results have been reported on whether closed kinetic chain exercises (such as a leg press) may induce more balanced activation of vastus medialis (VM) and lateralis (VL) muscles compared with open kinetic chain exercise (such as pure knee extension). This study aimed to 1) compare between-vasti motor unit activity and 2) analyze the combined motor unit behavior from both muscles between open and closed kinetic chain exercises. Thirteen participants (four women, mean ± SD age: 27 ± 5 yr) performed isometric knee extension and leg press at 10, 30, 50, 70% of the maximum voluntary torque. High density surface EMG signals were recorded from the VM and VL and motor unit firings were automatically identified by convolutive blind source separation. We estimated the total synaptic input received by the two muscles by analyzing the difference in discharge rate from recruitment to target torque for motor units matched by recruitment threshold. When controlling for recruitment threshold and discharge rate at recruitment, the motor unit discharge rates were higher for knee extension compared with the leg press exercise at 50% [estimate = 1.2 pulses per second (pps), standard error (SE) = 0.3 pps, P = 0.0138] and 70% (estimate = 2.0 pps, SE = 0.3 pps, P = 0.0001) of maximal torque. However, no difference between the vasti muscles were detected in both exercises. The estimates of synaptic input to the muscles confirmed these results. In conclusion, the estimated synaptic input received by VM and VL was similar within and across exercises. However, both muscles had higher firing rates and estimated synaptic input at the highest torque levels during knee extension. Taken together, the results show that knee-extension is more suitable than leg-press exercise at increasing the concurrent activation of the vasti muscles.

NEW & NOTEWORTHY There is a significant debate on whether open kinetic chain, single-joint knee extension exercise can influence the individual and combined activity of the vasti muscles compared with closed kinetic chain, multijoint leg press exercise. Here we show that attempting to change the contribution of either the vastus medialis or vastus lateralis via different forms of exercise does not seem to be a viable strategy. However, the adoption of open kinetic chain knee extension induces greater discharge rate and estimated synaptic input to both vasti muscles compared with the leg press.
Skeletal muscle LINE-1 ORF1 mRNA is higher in older humans but decreases with endurance exercise and is negatively associated with higher physical activity
Authors: Roberson Paul A. , Romero Matthew A. , Osburn Shelby C. , Mumford Petey W. , Vann Christopher G. , Fox Carlton D. , McCullough Danielle J. , Brown Michael D. , Roberts Michael D.
Published: August 2019

The long interspersed nuclear element-1 (L1) is a retrotransposon that constitutes 17% of the human genome and is associated with various diseases and aging. Estimates suggest that ~100 L1 copies are capable of copying and pasting into other regions of the genome. Herein, we examined if skeletal muscle L1 markers are affected by aging or an acute bout of cycling exercise in humans. Apparently healthy younger (23 ± 3 y, n = 15) and older participants (58 ± 8 y, n = 15) donated a vastus lateralis biopsy before 1 h of cycling exercise (PRE) at ~70% of heart rate reserve. Second (2 h) and third (8 h) postexercise muscle biopsies were also obtained. L1 DNA and mRNA expression were quantified using three primer sets [5′ untranslated region (UTR), L1.3, and ORF1]. 5′UTR and L1.3 DNA methylation as well as ORF1 protein expression were also quantified. PRE 5′UTR, ORF1, or L1.3 DNA were not different between age groups ( P > 0.05). ORF1 mRNA was greater in older versus younger participants ( P = 0.014), and cycling lowered this marker at 2 h versus PRE ( P = 0.027). 5′UTR and L1.3 DNA methylation were higher in younger versus older participants ( P < 0.05). Accelerometry data collected during a 2-wk period before the exercise bout indicated higher moderate-to-vigorous physical activity (MVPA) levels per day was associated with lower PRE ORF1 mRNA in all participants ( r = −0.398, P = 0.032). In summary, skeletal muscle ORF1 mRNA is higher in older apparently healthy humans, which may be related to lower DNA methylation patterns. ORF1 mRNA is also reduced with endurance exercise and is negatively associated with higher daily MVPA levels.

NEW & NOTEWORTHY The long interspersed nuclear element-1 (L1) gene is highly abundant in the genome and encodes for an autonomous retrotransposon, which is capable of copying and pasting itself into other portions of the genome. This is the first study in humans to demonstrate that certain aspects of skeletal muscle L1 activity are altered with aging. Additionally, this is the first study in humans to demonstrate that L1 ORF1 mRNA levels decrease after a bout of endurance exercise, regardless of age.
Regional differences in Ca2+ entry along the proximal-middle-distal muscle axis during eccentric contractions in rat skeletal muscle
Authors: Tabuchi Ayaka , Eshima Hiroaki , Tanaka Yoshinori , Nogami Shunsuke , Inoue Naoki , Sudo Mizuki , Okada Hidetaka , Poole David C. , Kano Yutaka
Published: August 2019

Eccentric (ECC) contraction-induced muscle damage is associated with calcium ion (Ca2+) influx from the extracellular milieu through stretch-activated channels. It remains unknown whether Ca2+ influx consequent to repetitive ECC contractions is nonuniform across different muscle regions. We tested the hypothesis that there are regional differences in Ca2+ entry along the proximal-middle-distal muscle axis. Tibialis anterior (TA) muscles of adult male Wistar rats were exposed by reflecting the overlying skin and fasciae and ECC contractions evoked by peroneal nerve stimulation paired with simultaneous ankle extension (50 times/set, 2 protocols: 1 set and 10 sets). During ECC in the proximal, middle, and distal TA, we determined 1) muscle fiber extension by high-speed camera (200 frames/s) and 2) Ca2+ accumulation by in vivo bioimaging (Ca2+-sensitive probe Fura-2-acetoxymethyl ester). Muscle fiber extension from resting was significantly different among regions (i.e., proximal, 4.0%: < middle, 11.2%: < distal, 17.0%; ECC phase length at 500th contraction). Intracellular Ca2+ accumulation after 1 set of ECC was higher in the distal (1.46 ± 0.04, P < 0.05) than the proximal (1.27 ± 0.04) or middle (1.26 ± 0.05) regions. However, this regional Ca2+ accumulation difference disappeared by 32.5 min after the 1 set protocol when the muscle was quiescent and by contraction set 5 for the 10-set protocol. The initial preferential ECC-induced Ca2+ accumulation observed distally was associated spatially with the greater muscle extension compared with that of the proximal and middle regions. Disappearance of the regional Ca2+ accumulation disparity in quiescent and ECC-contracting muscle might be explained, in part, by axial Ca2+ propagation and account for the uniformity of muscle damage across regions evident 3 days post-ECC.

NEW & NOTEWORTHY After 1 set of 50 eccentric (ECC) contractions in the anterior tibialis muscle, intracellular Ca2+ ([Ca2+]i) accumulation evinces substantial regional heterogeneity that is spatially coherent with muscle length changes (i.e., distal [Ca2+]i > middle, proximal). However, irrespective of whether 50 or 500 ECC contractions are performed, this heterogeneity is subsequently abolished, at least in part, by axial intracellular Ca2+ propagation. This Ca2+ homogenization across regions is consistent with the absence of any interregional difference in muscle damage 3 days post-ECC.
Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel
Authors: Tian Zhaohui , Song Lijun , Li Xinmin
Published: August 2019

Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.
Calculation Method of Seismic Residual Displacement of Sheet Pile Quay Walls
Authors: Wang Liyan , Yajun Zhou , Gong Wenxue , Li Jinsong , Ishimwe Aimable
Published: August 2019

Sheet pile quay walls have widely been used in port engineering, hydraulic engineering, and civil engineering, but the sheet pile quay is a flexible retaining structure, which undergoes large deformation during earthquakes. The seismic design methods of the sheet pile quay wall in different countries are greatly different, and there is deficit of studies performed on the seismic residual displacement of the sheet pile quay walls. Based on the pseudostatic method and the calculation method for obtaining the dynamic earth pressure of clay soil, it is assumed that the cantilever part of the sheet pile quay wall bears the dynamic active earth pressure and the part in deep soil bears dynamic passive earth pressure on the side of the sea and bears dynamic active earth pressure on the side of the ground. The hydrodynamic pressure acting in front of the wall is calculated using Westergaard’s approach. The displacement of the front wall of the sheet pile quay is calculated, respectively, according to the upper part and lower part of mud surface. Based on the deflection curve differential equation and boundary conditions, the calculating formulas on seismic residual displacements of the sheet pile quay walls are derived and the proportional displacement method for determining the tension force of the pull rod is given. Combining with an engineering case, the theoretical calculation results are compared with the ADINA simulation results, and comparison results show that these two calculation methods are close under the mud, but they have little difference in the calculation results of the part above the mud because of the proportional displacement method of the tension force of the pull rod.
An Enhanced Lightning Attachment Procedure Optimization with Quasi-Opposition-Based Learning and Dimensional Search Strategies
Authors: Zheng Tongyi , Luo Weili
Published: August 2019

Lightning attachment procedure optimization (LAPO) is a new global optimization algorithm inspired by the attachment procedure of lightning in nature. However, similar to other metaheuristic algorithms, LAPO also has its own disadvantages. To obtain better global searching ability, an enhanced version of LAPO called ELAPO has been proposed in this paper. A quasi-opposition-based learning strategy is incorporated to improve both exploration and exploitation abilities by considering an estimate and its opposite simultaneously. Moreover, a dimensional search enhancement strategy is proposed to intensify the exploitation ability of the algorithm. 32 benchmark functions including unimodal, multimodal, and CEC 2014 functions are utilized to test the effectiveness of the proposed algorithm. Numerical results indicate that ELAPO can provide better or competitive performance compared with the basic LAPO and other five state-of-the-art optimization algorithms.
Quality and Acceptability of Fresh and Long-Term Frozen In-Bag Dry-Aged Lean Bull Beef
Authors: Zhang Renyu , Yoo Michelle J. Y. , Farouk Mustafa M.
Published: August 2019

In-bag dry-aged lean beef was produced using a stepwise ageing process. Lean bull beef striploins were dry-aged at 2°C, 75% RH under three different air velocities: 0.5, 1.5, and 2.5 m·s−1for 7 days followed by wet-ageing for 14 days. The quality and acceptability of the dry-aged beef were compared with equivalent beef dry-aged for 21 days at 0.5 m·s−1which served as a control. Two portions of the dry-aged beef (7/21 days) were randomly selected and held frozen at −18°C for 12 months. Shear force, drip, and cook loss decreased significantly (p<0.05) with dry-ageing time. Increased air velocities accelerated dehydration process with no negative impact on the meat quality, microbiological safety, and consumer acceptability compared to the control (p>0.05). Frozen storage for 12 months had little or no effect on the quality and acceptability of the dry-aged lean beef (p>0.05). Dry-aged lean beef of equivalent quality and palatability, with a lower level of surface microorganisms and higher yield compared to the control, could be produced using the stepwise ageing process.
Cyst Viability and Economic Significance of Hydatidosis in Southern Ethiopia
Authors: Guduro Getachew Gedeno , Desta Angesom Hadush
Published: August 2019

Hydatidosis is cystic parasitosis caused by a larval stage of Echinococcus granulosus with immense economic and public health significance. A cross-sectional study was conducted from November 2016 to April 2017 in the city municipal abattoir of Southern Ethiopia with the aim of determining prevalence and cyst fertility and estimating financial losses associated with organ condemnation. The visceral organs of about 400 cattle were examined for hydatid cysts after slaughter. Postmortem examination, cyst characterization, and direct financial loss estimations were carried out. From the total 400 cattle examined, 208 (52%) were found positive for hydatid cyst infection in one or more of their organs. A total of about 395 hydatid cysts were collected from different organs of the infected cattle. Anatomical distribution of the cysts indicated that around 245 (62.03 %) were found in lung, 91 (23.04%) in liver, 26 (6.58%) in heart, 21 (5.32%) in spleen, and 12(3.04%) in kidney. From the total 395 cysts collected, 166 (42.03%) were found fertile and 229 (57.97%) nonfertile. From the total fertile cysts, 70 (42.17%) were found to be viable and 96 (57.83%) nonviable. Furthermore, from the total nonfertile cysts, 204 (89.08%) and 25 (10.91%) were sterile and calcified, respectively. Distribution of cyst calcification was higher in liver and fertility rate was higher in the cysts of lungs. The statistical analysis showed that the prevalence of hydatidosis was found to be significantly associated with age of the studied animals (P<0.05). However, there was no significant association (P>0.05) between the prevalence of bovine hydatidosis and other risk factors such as sex, breed, body condition, and origin of animals. The annual financial loss calculated from organ condemnation was estimated about 58,114.62 USD. This study revealed that hydatidosis is a highly prevalent disease in the study area with a huge economic losses. Therefore, there is a need for immediate intervention by breaking the life cycle of the parasite to alleviate its economic impact and zoonotic risks to humans.
Correlates of Overweight in Children and Adolescents Living at Different Altitudes: The Peruvian Health and Optimist Growth Study
Authors: Santos Carla , Bustamante Alcibíades , Hedeker Donald , Vasconcelos Olga , Garganta Rui , Katzmarzyk Peter T. , Maia José
Published: August 2019

Background and Aim. Overweight prevalence in children and adolescents shows great variability which is related to individual-level and environmental-level factors. The present study aimed to determine the prevalence of and factors associated with overweight in Peruvian children and adolescents living at different altitudes. Methods. 8568 subjects, aged 6–16 y, from the sea level, Amazon, and high-altitude regions were sampled. Overweight was identified using BMI; biological maturation and physical fitness were measured; school characteristics were assessed via an objective audit. Results. Overweight prevalence decreased with age (28.3% at 6 y to 13.9% at 16 y); it was higher in girls (21.7%) than boys (19.8%) and was higher at the sea level (41.3%), compared with Amazon (18.8%) and high-altitude (6.3%) regions. Approximately 79% of the variance in overweight was explained by child-level characteristics. In Model 1, all child-level predictors were significant (p<0.001); in Model 2, six out of nine added school-level predictors (number of students, existence of policies and practices for physical activity, multisports-roofed, duration of Physical Education classes, and extracurricular activities) were significant (p<0.001); in Model 3, subjects living at high altitudes were less likely to be overweight than those living at the sea level. Conclusions. Child- and school-level variables played important roles in explaining overweight variation. This information should be taken into account when designing more efficient strategies to combat the overweight and obesity epidemic.
Use of Phenol as a Local Anaesthetic for Adult Grommet Insertion in Resource-Limited Settings: A Preliminary Report
Authors: Aluko AbdulAkeem Adebayo
Published: August 2019

Background. Grommet insertion is one of the most commonly performed minor surgical procedures in otolaryngological practice. For such minor procedures in the outpatient, local anaesthetics are preferred; this is even more so in adults especially for grommet insertion. This study described our experience with the use of phenol as a local anaesthetic agent for grommet insertion in adults.Methods. Phenol was used as a local anaesthetic agent that was applied topically for grommet insertion in adult patients as outpatient procedures between January and September 2018 in two tertiary hospitals. Data collected were analyzed using the Statistical Package for Social Sciences (SPSS IBM) version 23.0 computer software.Results. Nineteen ear drums were operated in patients aged between 20 and 52 years. No pain or discomfort was reported by 89.5% and 94.7% had no bleeding. There was no vertigo in all the cases that completed the procedures.Conclusion. This preliminary result shows that the use of phenol as a topical local anesthetic is simple, safe, and effective especially in resource-limited environments.
Infant Feeding Practices of HIV Positive Mothers and Its Association with Counseling and HIV Disclosure Status in Ethiopia: A Systematic Review and Meta-Analysis
Authors: Belay Getaneh Mulualem , Wubneh Chalachew Adugna
Published: August 2019

Introduction. Breastfeeding is the ideal food source for all newborns globally. However, in the era of Human Immune Deficiency Virus (HIV) infection, feeding practice is a challenge due to mother-to-child HIV transmission. Therefore, this systematic review and meta-analysis aimed to estimate the national prevalence of exclusive breastfeeding and mixed feeding practices among HIV positive mothers and its association with counseling and HIV disclosure status to the spouse in Ethiopia. Methods. We searched all available articles from the electronic databases including PubMed, EMBASE, Google Scholar, and the Web of Science. Moreover, reference lists of the included studies and the Ethiopian institutional research repositories were used. Searching of articles was limited to the studies conducted in Ethiopia and published in English language. We have included observational studies including cohort, cross-sectional, and case-control studies. The weighted inverse variance random effects model was used. The overall variations between studies were checked through heterogeneity test (I2). Subgroup analysis by region was conducted. To assess the quality of the study, the Joanna Briggs Institute (JBI) quality appraisal criteria were employed. Publication bias was checked with the funnel plot and Egger’s regression test. Result. A total of 18 studies with 4,844 participants were included in this study. The national pooled prevalence of exclusive breastfeeding and mixed feeding practices among HIV positive mothers were 63.43% (95% CI: 48.19, 78.68) and 23.11% (95% CI: 10.10, 36.13), respectively. In the subgroup analysis, the highest prevalence of exclusive breastfeeding practice was observed in Tigray (90.12%) and the lowest in Addis Ababa (41.92%). Counseling on feeding option with an odds ratio of 4.32 (95% CI: 2.75, 6.77) and HIV disclosure status to the spouse with an odds ratio of 6.05 (95% CI: 3.03, 12.06) were significantly associated with exclusive breast feedings practices. Conclusion. Most mothers report exclusive breastfeeding, but there are still almost a quarter of mothers who mix feed. Counseling on feeding options and HIV disclosure status to the spouse should be improved.
Vibration Control Performance Analysis and Shake‐Table Test of a Pounding Tuned Rotary Mass Damper under the Earthquake
Authors: Li Shujin , Sun Lei , Kong Fan
Published: August 2019

The voided biaxial concrete slab has been widely used in the engineering field. The slab has become a popular choice for designers and architects looking to reduce slab thickness and overall structure weight recently. Utilizing the empty space in the voided slab and introducing the structural control technology of mass damper into it, a new pounding tuned rotary mass damper (PTRMD) is proposed in this paper. This damper is designed to locate in the prefabricated hollow module to mitigate response of structure subject to disastrous excitations. The damper combines the characteristics of pounding mechanisms (PMDs) and tuned rotary mass dampers (TRMDs). This is achieved by a ball rolling on a curved orbit and a fixed stroke‐limiting plate. The structural control performance of the PTRMD is studied numerically and verified experimentally. Specifically, first, the motion equations for a single‐degree‐of‐freedom (SDOF) and multiple‐degree‐of‐freedom (MDOF) system with PTRMDs are derived. Furthermore, numerical results show that the PTRMD provides significant energy dissipation, and thus, is quite effective in reducing the structure response. Besides, the PTRMD generally exhibits better control performance and robustness in terms of vibration suppression compared with the TRMD proposed by the authors before. Finally, a shake‐table test is conducted to verify the damping effect of a PTRMD‐controlled SDOF system. Pertinent results confirm the effectiveness and robustness of PTRMDs for structural control.
Functions of Exosomes in the Triangular Relationship between the Tumor, Inflammation, and Immunity in the Tumor Microenvironment
Authors: Wang Tiantian , Nasser Moussa Ide , Shen Jie , Qu Shujuan , He Qingnan , Zhao Mingyi
Published: August 2019

Exosomes are extracellular vesicles that contain diverse components such as genetic materials, proteins, and lipids. Owing to their distinct derivation and tissue specificity, exosomes act as double-edged swords during the development of neoplasms. On the one hand, tumor-derived exosomes can modulate the immune system during tumorigenesis by regulating inflammatory cell infiltration and oxidative stress and by promoting epithelial-to-mesenchymal transition and immune-induced tumor dormancy. On the other hand, components of specific immune cell-derived exosomes may contribute to the efficacy of antitumor immunotherapy. In this review, we demonstrate the pivotal role of exosomes in the triangular relationship in the tumor microenvironment between the tumor, inflammation, and immunity, which may provide potential strategies for tumor immunotherapy at genetic and cellular levels.
Allometric Growth of the Freshwater CrabPotamon algeriense(Bott, 1967) (Decapoda, Brachyura, Potamidae) in Oued Zegzel, a Mountain Stream, in the Northeast of Morocco
Authors: Fadlaoui Soufiane , Mahjoub Mohammed , El Asri Ouahid , Melhaoui Mohammed
Published: August 2019

A morphometric study has been carried out for the first time on the population of the freshwater crabPotamon algerienseinhabiting Oued Zegzel, a tributary of the Lower Moulouya River, in the northeast of Morocco. Crabs were collected monthly over one year (October 2017 to September 2018) by excavating burrows and searching under blocks. A total of 669 crabs were obtained, 291 females and 378 males. Regression analysis was performed among carapace width (CW), as the reference dimension, and wet weight (WW), carapace length (CL), length and width of abdomen (AL and AW), and length and width of the cheliped (ChL and ChW) were chosen as dependent variables, using the allometric method. Based on Somerton’s technique, the onset of sexual maturity was estimated to occur at around 27mm CW for males and 32mm CW for females. The growth patterns recorded forP. algerienseare associated with the species reproductive strategy, i.e., preparation of body parts involved in female acquisition and egg incubation, like the male cheliped and the female abdomen, respectively. Among the 291 females sampled, 10.20% were left-handed and 89.80% were right-handed, while among the 378 males examined, 10.32% were left-handed and 89.68% were right-handed. It was concluded that the cheliped width and the abdominal width ofP. algerienseare the morphometric variables most appropriate to estimate the size at the beginning of the sexual maturity for males and females of this species, respectively.
On the Existence of a Cyclic Near-Resolvable (6n+4)-Cycle System of 2K12n+9
Authors: Aldiabat Raja'i , Ibrahim Haslinda , Karim Sharmila
Published: August 2019

In this article, we prove the existence of a simple cyclic near-resolvable v-1/2-cycle system of 2Kv for v≡9  mod  12 by the method of constructing its starter. Then, some new properties and results related to this construction are formulated.
Analysis of the Vibration Characteristics of a Boring Bar with a Variable Stiffness Dynamic Vibration Absorber
Authors: Li Lie , Sun Beibei , Hua Haitao
Published: August 2019

Boring bars are widely used in deep hole machining. Due to the low stiffness of the long cantilever boring bar, vibration often occurs in the boring process. Vibration suppression can permit higher productivity and a better surface finish. To improve the performance of boring operations, a variable stiffness dynamic vibration absorber (DVA) is added inside the boring bar to reduce the vibration. The stiffness of the DVA is provided by two rubber bushes placed inside the DVA. By changing the axial compression, the stiffness of the DVA can be adjusted to accommodate different excitation frequencies. By establishing the relationship between the stiffness of the DVA and the axial compression of the rubber bush, the optimal stiffness for different excitation frequencies can always be found. A boring experiment is conducted, and the results show that, by selecting a reasonable axial compression, the vibration of the boring bar can be effectively suppressed.
Effect of Rotation Friction Ratio on the Power Extraction Performance of a Passive Rotation VAWT
Authors: Zhu Jianyang , Tian Changbin
Published: August 2019

This paper performs a systematic numerical study to investigate the effect of rotation friction ratio on the power extraction performance of a passive rotation H-type vertical axis wind turbine (H-VAWT). In contrast to the previous literature, the present work does not impose rotation velocity on the turbine, and the rotation friction ratio which reflects the effect of external load characteristics on the turbine is introduced to the governing equation of the turbine. During each iteration, the rotation velocity of the turbine is computed after having determined the aerodynamic torque exerted on the blade of the turbine. This is more consistent with the actual working environment of the H-VAWT. A novel numerical coupling model was developed to simulate the interaction between the fluid and the passive rotation of the H-VAWT; then, the power extraction performance of the turbine with different rotation friction ratio was systematically analyzed. The results demonstrate that the power extraction performance of H-VAWT will be enhanced when the H-VAWT has appropriate rotation friction ratio. It is also found that the flow separation induced by large angle of attack is alleviated essentially if the H-VAWT has appropriate rotation friction ratio, which makes the H-VAWT have better energy extraction performance.