bluuebunny/crossref_metadata_2025 huggingface dataset:
MAIT cells, TCR γδ+ cells and ILCs cells in human breast milk and blood from HIV infected and uninfected women
Authors: Bedin Anne‐Sophie , Molès Jean‐Pierre , Rutagwera David , Nagot Nicolas , Kankasa Chipepo , Tylleskär Thorkild , Valverde‐Villegas Jaqueline M. , Durand Mèlusine , Van de Perre Philippe , Tuaillon Edouard
Published: February 2019

Background

Human breast milk cells remain poorly characterized for the presence of unconventional T lymphocytes and innate lymphoid cells (ILCs).

Methods

Early breast milk was collected from eight HIV‐uninfected and 11 HIV‐infected women 3‐12 days after delivery. Mucosal‐associated invariant T cells (MAIT cells), TCR γδ cells, and innate lymphoid cells (ILCs) were analyzed in breast milk and paired blood samples.

Results

CD161+/TRAV1‐2 + MAIT cells were detected in breast milk, accounting for a median (IQR) of 0.08% (0.06‐0.16) and 0.17% (0.16‐0.31) of CD45+ breast milk cells in HIV‐uninfected and HIV‐infected women, respectively. A selective compartmentalization of γδ T lymphocytes was observed in breast milk. Median (IQR) frequency of γδ T lymphocytes was 8.95% (8.64‐12.14) among breast milk lymphocyte cells compared to 2.54% (1.81‐4.10) in blood (P = 0.03) in HIV‐uninfected women, and 7.26% (4.22‐10.54) in breast milk versus 3.31% (2.54‐3.80) in blood (P = 0.004) from HIV‐infected women. The proportion of group 1 ILC (ILC1) among total ILCs was higher in breast milk compared to blood in HIV‐uninfected women (P = 0.03) and HIV‐infected women (P = 0.001). The frequency of ILC2 among total ILCs tends to be lower in breast milk compared to blood in HIV‐uninfected women (P = 0.06) and HIV‐infected women (P = 0.03).

Conclusion

Unconventional T cells and ILCs that may be involved in both the protection against infection of the lactating mammary gland and maturation of infant's gut and microbiomes account for a detectable fraction of breast milk cells.
Exploring the potential for marine aquaculture to contribute to ecosystem services
Authors: Gentry Rebecca R. , Alleway Heidi K. , Bishop Melanie J. , Gillies Chris L. , Waters Tiffany , Jones Robert
Published: February 2019

Marine aquaculture is growing quickly and has substantial effects on people and the environment. Existing research has demonstrated that marine aquaculture can contribute to ecosystem service provisioning that extends beyond production of a resource; however, the extent and significance of these goods and services are not well understood. Here we review existing knowledge of ecosystem service provision by marine aquaculture by systematically examining 129 peer reviewed papers that describe the provision of nine distinct ecosystem services by operational or experimental marine aquaculture farms. We quantify service provision and classify services by type and by farm characteristics. We show that while certain services, such as nutrient absorption by kelp aquaculture, are well understood and have been documented across multiple species, scales and environments, the evidence for other services, such as the cultural service of tourism, is currently minimal. Importantly, we identify ecosystem services associated with a diversity of farm types (including fish, bivalve, algae and polyculture farms) but find that certain services were most often delivered by specific farm types (e.g. habitat services were most often associated with fish farms). Incorporating acknowledgement of ecosystem services into farm design and planning has the potential to improve environmental performance and sustainable management of aquaculture. However, outstanding questions, including how spatial expansion of marine aquaculture will affect the provisioning of these services, are important challenges facing sustainable development.
Biometric Elections in Poor Countries: Wasteful or a Worthwhile Investment?
Authors: Gelb Alan , Diofasi Anna
Published: February 2019

Elections have emerged as a leading area for the application of biometric technology in developing countries, despite its high costs and uncertainty over its effectiveness. Why then do countries pursue such programs, often with the support of donors? The paper considers the costs and benefits of technology, where the latter involves its potential to reduce the probability of seriously disputed elections that escalate into violence. Based on the limited data available, it finds that a reduction in the probability of postelection violence by only a few percentage points could offset the cost of the technology. However, this is far from assured; we argue that biometric technology can only contribute to less disputed and less violent elections in particular settings, those where democracy is not yet well institutionalized but where political parties value the legitimacy conferred by elections that are sufficiently credible for their results to be accepted. One priority is therefore to screen potential cases carefully, before investing in costly programs that have a low probability of success. Another step toward using technology more effectively to underpin sustainable elections would be to build on voter registration drives to strengthen permanent identification assets such as civil registration and national ID programs that can serve as the basis for the voter roll.
Estimation of hepatitis B–positive rates in Chinese blood donors by combining predonation and postdonation screening results
Authors: Gao Zhan , Liu Jing , Fu Ping , Huang Mei , Cao Ru'an , Wen Xiuqiong , Zhang Chunhong , He Tao , Mao Wei , Liao Dan , Ke Ling , Yang Yashan , He Miao , Liu Yu , Wang Jingxing , Dodd Roger Y. , Ness Paul , Shan Hua
Published: February 2019

Background

Chinese blood centers use Hepatitis B surface antigen (HBsAg) rapid test (RT) in pre‐donation and two rounds of screening with different enzyme‐linked immunosorbent assays in post‐donation. Nucleic acid testing (NAT) on screening non‐reactive (SC‐) donations has been gradually implemented since 2010. Yet RT+ and SC‐/NAT+ donors are seldom included in hepatitis B virus (HBV) positive rate estimates in Chinese blood donors.

Methods

We performed HBsAg neutralization test (NT) on whole blood (WB) with pre‐donation RT+ results and post‐donation screening reactive (SC+) samples from Mianyang and Chongqing in 2015. The annual totals of pre‐ and post‐donation NT+ donors were combined with the annual totals of SC‐/NAT+ donors to derive the estimated HBV positive rates.

Result

In Mianyang and Chongqing, 59.4% and 68.2% of RT+ donors in Jan‐Aug 2015 contributed for NT, 95.5% and 97.2% of which were NT+ respectively. In 2015, 422 and 667 donors from Mianyang and Chongqing respectively were HBsAg RT+, yielding estimated 403 and 648 pre‐donation RT+/NT+ deferrals. 411 and 668 post‐donation SC+ samples were NT tested from Mianyang and Chongqing, of which 249 and 323 were NT+ respectively. An estimated 63 donors in Mianyang and 88 donors in Chongqing were SC‐/NAT+. The estimated HBV confirmed positive rate in blood donors are 1.59% in Mianyang and 1.01% in Chongqing.

Conclusion

Pre‐donation HBsAg RT effectively intercepts donations from HBV infected donors. Using NT confirmatory results from RT+, SC+ and SC‐/NAT+ donors, this study provides a model for more accurate estimation for HBV positive rates in China.
Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses
Authors: Berkowski William , Plummer Caryn E. , Ramos Renata , Czerwinski Sarah , Brooks Dennis , Gallagher Alex
Published: February 2019

Case description

A yearling Thoroughbred stallion and an 8‐year‐old Saddlebred mare were evaluated for persistent mucoid ocular discharge.

Clinical findings

Examination of both horses revealed copious yellow‐tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses.

Treatment and outcome

Under general anesthesia, the affected NLD was catheterized anterograde and contrast injected. Using fluoroscopic guidance, retrograde access to the distal NLD was obtained for through‐and‐through wire access. Over the wire, the stoma was dilated and a temporary stent placed for 4‐8 weeks. After the procedure, both horses were comfortable and free of ocular discharge at the minimum time of last follow‐up, 9 months postoperatively.

Clinical relevance

Fluoroscopically guided neocanalization is a viable alternative to traditional surgical approaches for NLD atresia, especially when access to the site of obstruction is limited.
Is there any Effect of Core Exercises on Anaerobic Capacity in Female Basketball Players?
Authors: Soslu Recep , Özer Ömer , Güler Melek , Doğan Ali Ahmet
Published: February 2019

This study was planned in order to determine the effect of core exercises on anaerobic capacity of female basketball players. Twelve female athletes who play basketball participated in the study voluntarily. The athletes had 3 sets of repetitive core exercise program performed 4 days a week for 8 weeks at the end of their basketball trainings. The height of the athletes was 165 ± 6.57 cm, body weight was 58.73 ± 7.42 kg, age was 19.75 ± 1.05, and athletic age was 6.11 ± 2.11. According to the analysis of the results, peak power, average power, right and left hand grip strengths and right and left arm fat percentages of post-tests were found to have a statistically significant difference than the pre-tests (p <0.05). To sum up, there are very few studies on the anaerobic capacity of female basketball players, especially on the upper extremities. It is observed that basketball players have a stronger anaerobic capacity in attack and defense and that core exercises have a positive effect on certain basketball-specific technical skills such as passing, shooting, dribbling and defensive movements, and in this sense, they will also increase the performance of the athletes.
A Review of Model Inaccuracy and Parameter Uncertainty in Laser Powder Bed Fusion Models and Simulations
Authors: Moges Tesfaye , Ameta Gaurav , Witherell Paul
Published: February 2019

This paper presents a comprehensive review on the sources of model inaccuracy and parameter uncertainty in metal laser powder bed fusion (L-PBF) process. Metal additive manufacturing (AM) involves multiple physical phenomena and parameters that potentially affect the quality of the final part. To capture the dynamics and complexity of heat and phase transformations that exist in the metal L-PBF process, computational models and simulations ranging from low to high fidelity have been developed. Since it is difficult to incorporate all the physical phenomena encountered in the L-PBF process, computational models rely on assumptions that may neglect or simplify some physics of the process. Modeling assumptions and uncertainty play significant role in the predictive accuracy of such L-PBF models. In this study, sources of modeling inaccuracy at different stages of the process from powder bed formation to melting and solidification are reviewed. The sources of parameter uncertainty related to material properties and process parameters are also reviewed. The aim of this review is to support the development of an approach to quantify these sources of uncertainty in L-PBF models in the future. The quantification of uncertainty sources is necessary for understanding the tradeoffs in model fidelity and guiding the selection of a model suitable for its intended purpose.
A Relative Equilibrium Decision Approach for Concept Design Through Fuzzy Cooperative Game Theory
Authors: Jing Liting , Li Zhi , Peng Xiang , Li Jiquan , Jiang Shaofei
Published: February 2019

In the early stages of the product design, multiple principle solutions are obtained through function solving, and a large number of conceptual schemes are generated by combination. Therefore, scheme decisions are important factors in the concept design. The existing decision methods primarily focus on the satisfaction of economic needs, and the impact of technical indicators on the technical performance of the scheme, while ignoring the conflict of needs between the two subject objectives in the decision process. Actual decisions need to be weighed against each other’s expectations. In addition, the qualitative interactive objectives will affect the decision direction of the conceptual scheme. Herein, we propose a relative equilibrium decision approach for concept design based on the fuzzy decision-making trial and evaluation laboratory-cooperative game model. This model is primarily divided into two parts. One is to solve the impact relationship between the objectives, and the objectives’ weights are obtained through fuzzy decision-making trial and evaluation laboratory (FDEMATEL). The second is to incorporate the objectives’ weights and impact utility into the cooperative game model, to reasonably weigh the relative interests of the two subjects to meet the corresponding interactions, and to obtain the scheme with the largest overall design desirability. Finally, the case study proves that this decision model can identify the optimal scheme. This model is proven to be robust by comparison with other methods.
Reduction in edge effects for small panels characterized by a parametric array source
Authors: Szabo J. P. , Bent A. D.
Published: February 2019

This study sought to explore effects of panel size on underwater acoustic transmission and reflection measurements made with a truncated parametric array source. The transmission loss (TL) and reflection loss spectra of aluminum panels of several different sizes were determined experimentally, and compared to predictions from plane wave theory in the 5–100 kHz frequency range. For the smallest panel size, there were significant discrepancies between experimental data and plane wave theory, which were attributed to contributions from edge-diffracted waves and interferences from the mounting fixture for the panel. For reflection measurements, the latter interference could be corrected for in part by measurement of the reflected signal from the sample holder (with no panel present), and subtracting this signal from reference and test panel waveforms. In order to reduce the contributions from edge diffracted waves in TL measurements, an alternative panel mounting system was investigated, which involved surrounding the panel in a reflective baffle. There was a significant improvement in agreement of experimental TL spectra with plane wave theory for the smallest aluminum panel when the baffle mounting arrangement was used.
Monitoring the Efficacy of Chloroquine-Primaquine Therapy for Uncomplicated Plasmodium vivax Malaria in the Main Transmission Hot Spot of Brazil
Authors: Ladeia-Andrade Simone , Menezes Maria José , de Sousa Taís Nóbrega , Silvino Ana Carolina R. , de Carvalho Jaques F. , Salla Laís C. , Nery Odaílton A. , de Melo Gladson N. P. , Corder Rodrigo M. , Rodrigues Priscila T. , Ferreira Marcelo U.
Published: February 2019

Emerging
Plasmodium vivax
resistance to chloroquine (CQ) may undermine malaria elimination efforts in South America. CQ-resistant
P. vivax
has been found in the major port city of Manaus but not in the main malaria hot spots across the Amazon Basin of Brazil, where CQ is routinely coadministered with primaquine (PQ) for radical cure of vivax malaria.
Genome Characterization, Prevalence, and Transmission Mode of a Novel Picornavirus Associated with the Threespine Stickleback Fish (Gasterosteus aculeatus)
Authors: Hahn Megan A. , Dheilly Nolwenn M.
Published: February 2019

The threespine stickleback species complex is an important model system in ecological and evolutionary studies because of the large number of isolated divergent populations that are experimentally tractable. For similar reasons, its coevolution with the cestode parasiteSchistocephalus solidus, its interaction with gut microbes, and the evolution of its immune system are of growing interest. Herein we describe the discovery of an RNA virus that infects both freshwater and anadromous populations of sticklebacks. We show that the virus is transmitted vertically in laboratory settings and found it in Sequence Reads Archives, suggesting that experiments using sticklebacks were conducted in the presence of the virus. This discovery can serve as a reminder that the presence of viruses in wild-caught animals is possible, even when animals appear healthy. Regarding threespine sticklebacks, the impact of Threespine Stickleback picornavirus (TSPV) on the fish biology should be investigated further to ensure that it does not interfere with experimental results.
Draft Genome Sequence of Vancomycin-Resistant Enterococcus faecium UEL170 (Sequence Type 412), Isolated from a Patient with Urinary Tract Infection in a Tertiary Hospital in Southern Brazil
Authors: Tavares Eliandro Reis , da Silva Lucas Fernando , Morey Alexandre Tadachi , de Oliveira Admilton Gonçalves , da Rocha Sergio Paulo Dejato , Ribeiro Renan Augusto , Hungria Mariangela , Thihara Isabella Ramos Trevizani , Perugini Marcia Regina Eches , Yamauchi Lucy Megumi , Yamada-Ogatta Sueli Fumie
Published: February 2019

Enterococcus faecium
is a leading cause of health care-associated infections, with specific lineages circulating in hospital settings worldwide. Here, we report the draft genome sequence of the multidrug-resistant and biofilm-producing
E. faecium
UEL170, sequence type 412 (ST412), isolated from an inpatient with a urinary tract infection.
Draft Genome Sequences of Four Metallo-Beta-Lactamase-Producing Multidrug-Resistant Klebsiella pneumoniae Clinical Isolates, Including Two Colistin-Resistant Strains, from Cairo, Egypt
Authors: Attia Heba , Szubin Richard , Yassin Aymen S. , Monk Jonathan M. , Aziz Ramy K.
Published: February 2019

The emergence and spread of metallo-beta-lactamase-producing multidrug-resistant
Klebsiella pneumoniae
are a serious public health threat. Here, we report the draft genome sequences of four
K. pneumoniae
strains isolated from Cairo, Egypt, including two panresistant colistin-resistant strains.
Complete Genome Sequence of
Halocella
sp. Strain SP3-1, an Extremely Halophilic, Glycoside Hydrolase- and Bacteriocin-Producing Bacterium Isolated from a Salt Evaporation Pond
Authors: Heng Sobroney , Sutheeworapong Sawannee , Prommeenate Peerada , Cheevadhanarak Supapon , Kosugi Akihiko , Pason Patthra , Waeonukul Rattiya , Ratanakhanokchai Khanok , Tachaapaikoon Chakrit
Published: February 2019

Halocella
sp. strain SP3-1, a cellulose-degrading bacterium, was isolated from a hypersaline evaporation pond in Thailand.
Draft Genome Sequence of Bacillus velezensis OSY-GA1, Which Encodes Multiple Antimicrobial Metabolites and Expresses Antimicrobial Activity against Foodborne Pathogens
Authors: Abdelhamid Ahmed G. , Hussein Walaa E. , Gerst Michelle M. , Yousef Ahmed E.
Published: February 2019

Bacillus velezensis
OSY-GA1 is a Gram-positive soil bacterium that exhibits antagonistic activities against Gram-positive and Gram-negative foodborne pathogens. Here, we present the strain’s draft genome, which is 4,009,999 bp long with an average G+C content of 46.2%.
Overlooked diversity in exotic Taraxacum in British Columbia, Canada
Authors: Björk Curtis R.
Published: February 2019

In almost all North American literature, including in British Columbia, weedy Taraxacum species have been named as Taraxacum officinale F.H.Wigg and Taraxacum erythrospermum Andrz. ex Besser (or Taraxacum laevigatum DC.). This coarse taxonomic approach ignores great diversity in morphology, ecology, and geographical distributions among the exotic established species. Taxonomic refinement would facilitate floristics and ecological studies when exotic Taraxacum species are involved, and the taxonomy of native Taraxacum must first determine which are and which are not native species, which in turn requires knowledge of sectional identity of any specimen. Exotic Taraxacum specimens were identified to species and taxonomic sections using refined species and sectional concepts that align with taxonomic standards used in the native ranges of the species in Europe. Seven exotic sections and one informally named group are found to be present in British Columbia (Borea, Boreigena, Celtica, Erythrosperma, Hamata, Naevosa, Taraxacum, and the Taraxacum fulvicarpum group). The number of exotic Taraxacum species known to occur in British Columbia to date exceeds 100. A key to the exotic sections of British Columbia Taraxacum is presented and the sections are characterized. Species known to date are listed by their sectional placement. Notes are also presented on distinguishing native from exotic Taraxacum in British Columbia.
Analysis, Design and Control of an Integrated Three-Level Buck Converter under DCM Operation
Authors: Zheng Wen-Ming , Zeng Wen-Liang , U Chi-Wa , Lam Chi-Seng , Lu Yan , Sin Sai-Weng , Wong Man-Chung , Martins Rui Paulo
Published: February 2019

A three-level buck (TLB) converter has the characteristics of higher voltage conversion efficiency, lower inductor current ripples, output voltage ripples and voltage stresses on switches when compared with the buck converters in continuous conduction mode (CCM). With a TLB converter integrated on a chip, we cannot avoid its discontinuous conduction mode (DCM) operation due to a smaller inductance and load variation. In this paper, we’ll present and discuss the analysis, design and control of a TLB converter under DCM operation, implemented in a 65[Formula: see text]nm CMOS process. Transistor level simulation results show that when the TLB converter operates at 100[Formula: see text]MHz with a 5[Formula: see text]nH on-chip inductor, a 10[Formula: see text]nF output capacitor and a 10[Formula: see text]nF flying capacitor, it can achieve an output conversion range of 0.7–1.2[Formula: see text]V from a 2.4[Formula: see text]V input supply, with a peak efficiency of 81.5%@120[Formula: see text]mW. The output load transient response is 100[Formula: see text]mV with 101[Formula: see text]ns for undershoot, and 86[Formula: see text]mV with 110[Formula: see text]ns for overshoot when [Formula: see text]–100[Formula: see text]mA. The maximum output voltage ripple is less than 19[Formula: see text]mV.
Application of activated carbon supported cobalt(II) tetraaminophthalocyanine towards preparation of dimethyl disulfide
Authors: Cheng Zhiliang , Dai Mingxing , Quan Xuejun , Li Shuo , Zheng Daomin , Liu Yaling , Yao Rujie
Published: February 2019

Dimethyl disulfide (DMDS) is an important fine chemical that can be prepared by the refined Merox process of oxidation of sodium methyl mercaptide (SMM) in the presence of a catalyst. In this paper, a novel activated carbon (AC) supported cobalt(II) tetraaminophthalocyanine (AC-CoTAPc) catalyst was prepared by the chemical grafting method. EA, UV-vis, FT-IR, BET and XPS were used to characterize the structure of the new catalyst. The effects of reaction time, catalyst dosage, reaction temperature and oxygen pressure on SMM conversion per pass (CPP[Formula: see text], yield (Yield[Formula: see text] and purity of DMDS product (Purity[Formula: see text] were investigated to evaluate the catalytic performance of new AC-CoTAPc catalyst. The results show that free CoTAPc is easily dissolved in this DMDS product, which needs extra post treatment and cannot be reused. The supported catalyst AC-CoTAPc can easily solve these problems and can be properly reused four times to get Yield[Formula: see text] and CPP[Formula: see text] higher than 70% and 90%. Under optimum conditions, the Yield[Formula: see text] andCPP[Formula: see text] of the AC-CoTAPc catalyst could be as high as 87.4% and 98.1%, with a purity[Formula: see text]of DMDS product of above 99.9%. AC-CoTAPc exhibits better catalytic and reuse performance than the commercial AC-supported sulphonated cobalt(II) phthalocyanine (AC-CoPcS) catalyst and shows broad industrial application prospects.
Synthesis, characterization and VOCs adsorption kinetics of diethylstilbestrol-substituted metallophthalocyanines
Authors: Kakı Esra , Gögsu Nurcan , Altındal Ahmet , Salih Bekir , Bekaroğlu Özer
Published: February 2019

Compound (4,4[Formula: see text] -hex-3-ene-3,4-diyl)bis(4,1-phenylene)bis(oxy)diphthalonitrile 3 was synthesized by the reaction of 4-nitrophthalonitrile 1 and diethylstilbestrol 2 in dry DMF in presence of dry K2CO3. New mononuclear phthalocyanines 4-6 were obtained from compound 3 by addition of the corresponding metal salts [Co(OAc)2 ⋅ 4H2O, Zn(OAc)2 ⋅ 2H2O and Cu(OAc)2]. The novel compounds were characterized by elemental analysis and FT-IR, UV-vis, 1H-NMR and MALDI-TOF mass spectroscopy techniques. The effects of four main groups of organic vapors on these novel compounds were studied and discussed. The adsorption kinetics of alkanes ([Formula: see text]-hexane and [Formula: see text]-octane), alcohols (methanol and 2-proponal), chlorinated hydrocarbons (dichloromethane and trichloromethane) and amines (diethylamine and triethylamine) on 4-6 were examined using three adsorption kinetic models: the Elovich equation, the pseudo-first-order equations and Ritchie’s equation. Results show that the linear regression analysis with respect to the pseudo-second-order rate equations generates a straight line that best fits the data of adsorption of alcohols and chlorinated hydrocarbons on Pc films. On the other hand, the Elovich equation generates a straight line that best fits the data of adsorption of alkanes and amines.
Numerical and Experimental Analysis of Damage Evolution and Martensitic Transformation in AISI 304 Austenitic Stainless Steel at Cryogenic Temperature
Authors: Kazemi Seyed Saied , Homayounfard Milad , Ganjiani Mehdi , Soltani Naser
Published: February 2019

In this research, ductile damage development and martensitic strain-induced phase transformation in plastic behavior of AISI 304 austenitic stainless steels at cryogenic temperatures are investigated. Nonlinear behavior of hardening and damage evolution could be observed in two-phase material as the result of strain-induced phase transformation. A simplified constitutive model for monotonic loadings, combining the effects of phase transformation and isotropic damage evolution has been introduced. Numerical analysis via implementing the model by means of a user subroutine UMAT in Abaqus/Standard is carried out. In addition, experiments including loading-unloading tensile test and X-ray diffraction test at cryogenic temperature 77[Formula: see text]K have been conducted to identify the parameters of the model and to compare with numerical results.
Bifurcation analysis of modeling biodegradation of Microcystins
Authors: Song Keying , Ma Wanbiao , Jiang Zhichao
Published: February 2019

In this paper, a model with time delay describing biodegradation of Microcystins (MCs) is investigated. Firstly, the stability of the positive equilibrium and the existence of Hopf bifurcations are obtained. Furthermore, an explicit algorithm for determining the direction and the stability of the bifurcating periodic solutions is derived by using the normal form theory and center manifold argument. Finally, some numerical simulations are carried out to illustrate the applications of the results.
Wave propagation of a discrete SIR epidemic model with a saturated incidence rate
Authors: Zhang Qiu , Wu Shi-Liang
Published: February 2019

This paper is concerned with the traveling wave solutions for a discrete SIR epidemic model with a saturated incidence rate. We show that the existence and non-existence of the traveling wave solutions are determined by the basic reproduction number [Formula: see text] of the corresponding ordinary differential system and the minimal wave speed [Formula: see text]. More specifically, we first prove the existence of the traveling wave solutions for [Formula: see text] and [Formula: see text] via considering a truncated initial value problem and using the Schauder’s fixed point theorem. The existence of the traveling wave solutions with speed [Formula: see text] is then proved by using a limiting argument. The main difficulty is to show that the limit of a decreasing sequence of the traveling wave solutions with super-critical speeds is non-trivial. Finally, the non-existence of the traveling wave solutions for [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text] is proved.
Bivariate q-Bernstein–Chlodowsky–Durrmeyer type operators and the associated GBS operators
Authors: Garg Tarul , İspir Nurhayat , Agrawal P. N.
Published: February 2019

This paper deals with the approximation properties of the [Formula: see text]-bivariate Bernstein–Chlodowsky operators of Durrmeyer type. We investigate the approximation degree of the [Formula: see text]-bivariate operators for continuous functions in Lipschitz space and also with the help of partial modulus of continuity. Further, the Generalized Boolean Sum (GBS) operator of these bivariate [Formula: see text]–Bernstein–Chlodowsky–Durrmeyer operators is introduced and the rate of convergence in the Bögel space of continuous functions by means of the Lipschitz class and the mixed modulus of smoothness is examined. Furthermore, the convergence and its comparisons are shown by illustrative graphics for the [Formula: see text]-bivariate operators and the associated GBS operators to certain functions using Maple algorithms.
Multiple solutions for a fourth-order elliptic equation of Kirchhoff type with variable exponent
Authors: Chung Nguyen Thanh
Published: February 2019

In this paper, we consider a class of fourth-order elliptic equations of Kirchhoff type with variable exponent [Formula: see text] where [Formula: see text], [Formula: see text], is a smooth bounded domain, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] is the operator of fourth-order called the [Formula: see text]-biharmonic operator, [Formula: see text] is the [Formula: see text]-Laplacian, [Formula: see text] is a log-Hölder continuous function and [Formula: see text] is a continuous function satisfying some certain conditions. A multiplicity result for the problem is obtained by using the mountain pass theorem and Ekeland’s variational principle provided [Formula: see text] is small enough.
Threshold-directed signature scheme based on hybrid number theoretic problems
Authors: Mohamad Mohd Saiful Adli
Published: February 2019

Directed signature is a type of function-based signature with the property that the signature only can be verified by a designated verifier and at certain times, the verifier should be able to convince anyone about the validity of the signature without revealing any secret information about the signature to the public. Taking into consideration the involvement of group decision making, some threshold directed signature schemes based on single number theoretic problems, such as integer factorization, discrete logarithm problem, and elliptic curve discrete logarithm problem, have been developed by cryptographers. Although the single-problem-based schemes are still invincible because there is still no cryptanalyst to find the solution to the problems, in the future, if the enemy or attacker manages to get the polynomial algorithm to solve the single problems, the schemes will no longer be practiced and applied. For such reason, in this paper, we propose a new threshold-directed signature scheme based on integer factorization and discrete logarithm problems. The advantage of our scheme is based on the assumption that it is very unlikely to solve two hard number theoretic problems simultaneously. We also show that our scheme is secured against some cryptographic attacks and also significantly efficient compared with threshold signature scheme based on single problem.
Novel RFI Mitigation Methods in the Square Kilometre Array 1 Mid Correlator Beamformer
Authors: Gunaratne Thushara , Carlson Brent , Comoretto Gianni
Published: February 2019

The Square Kilometre Array (SKA) Phase 1 Mid Correlator Beamformer (Mid.CBF) adopts two novel methods to mitigate radio frequency interference (RFI) at the various stages of its signal chains. First, the pioneering Sample Clock Frequency Offset (SCFO) sampling suppresses interference which leaks into individual ‘Frequency-Slice’ (FS) (sub-bands) in the cross-correlations. Second, the ‘Shift-Resample-Shift-Back’ method minimizes the addition of noise due to strong clustered RFI. Empirical studies conducted with simulation of the systems confirm that the proposed methods significantly reduce the impact of RFI on the output of the radio telescope.
Requirements Engineering in the New Product Development Process: A Structured Literature Review
Authors: Iaksch Jaqueline Sebastiany , Borsato Milton , Schimdt Juliana , Vaine Arturo
Published: February 2019

The New Product Development Process (NDP) is noticed as a critical factor to maintain the competitiveness in organizations. New products allow us to focus on taking a competitive position. Also, the first and most important reason for any new product development is to provide new value to the customer. In this sense, the Requirements Engineering (RE) approach plays a vital role within the New Product Development Process (NDP) lifecycle, once the product performance and its acceptability on the market depend on how RE is integrated into the product development. In this way, this paper aims to identify the proposed solutions and trends regarding RE, through a literature review based on studies produced in the last five years. Hence, the existing gaps in the literature about this theme are presented and analyzed. In order to achieve these objectives, the present study was based on ProKnow-C process (Knowledge Development Process — Constructivist).
Continuous object access profiling and optimizations to overcome the memory wall and bloat
Authors: Odaira Rei , Nakatani Toshio
Published: February 2019

Future microprocessors will have more serious memory wall problems since they will include more cores and threads in each chip. Similarly, future applications will have more serious memory bloat problems since they are more often written using object-oriented languages and reusable frameworks. To overcome such problems, the language runtime environments must accurately and efficiently profile how programs access objects. We propose Barrier Profiler, a low-overhead object access profiler using a memory-protection-based approach called pointer barrierization and adaptive overhead reduction techniques. Unlike previous memory-protection-based techniques, pointer barrierization offers per-object protection by converting all of the pointers to a given object to corresponding barrier pointers that point to protected pages. Barrier Profiler achieves low overhead by not causing signals at object accesses that are unrelated to the needed profiles, based on profile feedback and a compiler analysis. Our experimental results showed Barrier Profiler provided sufficiently accurate profiles with 1.3% on average and at most 3.4% performance overhead for allocation-intensive benchmarks, while previous code-instrumentation-based techniques suffered from 9.2% on average and at most 12.6% overhead. The low overhead allows Barrier Profiler to be run continuously on production systems. Using Barrier Profiler, we implemented two new online optimizations to compress write-only character arrays and to adjust the initial sizes of mostly non-accessed arrays. They resulted in speed-ups of up to 8.6% and 36%, respectively.
A case for unlimited watchpoints
Authors: Greathouse Joseph L. , Xin Hongyi , Luo Yixin , Austin Todd
Published: February 2019

Numerous tools have been proposed to help developers fix software errors and inefficiencies. Widely-used techniques such as memory checking suffer from overheads that limit their use to pre-deployment testing, while more advanced systems have such severe performance impacts that they may require special-purpose hardware. Previous works have described hardware that can accelerate individual analyses, but such specialization stymies adoption; generalized mechanisms are more likely to be added to commercial processors. This paper demonstrates that the ability to set an unlimited number of fine-grain data watchpoints can reduce the runtime overheads of numerous dynamic software analysis techniques. We detail the watchpoint capabilities required to accelerate these analyses while remaining general enough to be useful in the future. We describe a hardware design that stores watchpoints in main memory and utilizes two different on-chip caches to accelerate performance. The first is a bitmap lookaside buffer that stores fine-grained watchpoints, while the second is a range cache that can efficiently hold large contiguous regions of watchpoints. As an example of the power of such a system, it is possible to use watchpoints to accelerate read/write set checks in a software data race detector by nearly 9x.
Scalable address spaces using RCU balanced trees
Authors: Clements Austin T. , Kaashoek M. Frans , Zeldovich Nickolai
Published: February 2019

Software developers commonly exploit multicore processors by building multithreaded software in which all threads of an application share a single address space. This shared address space has a cost: kernel virtual memory operations such as handling soft page faults, growing the address space, mapping files, etc. can limit the scalability of these applications. In widely-used operating systems, all of these operations are synchronized by a single per-process lock. This paper contributes a new design for increasing the concurrency of kernel operations on a shared address space by exploiting read-copy-update (RCU) so that soft page faults can both run in parallel with operations that mutate the same address space and avoid contending with other page faults on shared cache lines. To enable such parallelism, this paper also introduces an RCU-based binary balanced tree for storing memory mappings. An experimental evaluation using three multithreaded applications shows performance improvements on 80 cores ranging from 1.7x to 3.4x for an implementation of this design in the Linux 2.6.37 kernel. The RCU-based binary tree enables soft page faults to run at a constant cost with an increasing number of cores,suggesting that the design will scale well beyond 80 cores.
Applying transactional memory to concurrency bugs
Authors: Volos Haris , Tack Andres Jaan , Swift Michael M. , Lu Shan
Published: February 2019

Multithreaded programs often suffer from synchronization bugs such as atomicity violations and deadlocks. These bugs arise from complicated locking strategies and ad hoc synchronization methods to avoid the use of locks. A survey of the bug databases of major open-source applications shows that concurrency bugs often take multiple fix attempts, and that fixes often introduce yet more concurrency bugs. Transactional memory (TM) enables programmers to declare regions of code atomic without specifying a lock and has the potential to avoid these bugs. Where most previous studies have focused on using TM to write new programs from scratch, we consider its utility in fixing existing programs with concurrency bugs. We therefore investigate four methods of using TM on three concurrent programs. Overall, we find that 29% of the bugs are not fixable by transactional memory, showing that TM does not address many important types of concurrency bugs. In particular, TM works poorly with extremely long critical sections and with deadlocks involving both condition variables and I/O. Conversely, we find that for 56% of the bugs, transactional memory offers demonstrable value by simplifying the reasoning behind a fix or the effort to implement a fix, and using transactions in the first place would have avoided 71% of the bugs examined. We also find that ad hoc synchronization put in place to avoid the overhead of locking can be greatly simplified with TM, but requires hardware support to perform well.
Execution migration in a heterogeneous-ISA chip multiprocessor
Authors: DeVuyst Matthew , Venkat Ashish , Tullsen Dean M.
Published: February 2019

Prior research has shown that single-ISA heterogeneous chip multiprocessors have the potential for greater performance and energy efficiency than homogeneous CMPs. However, restricting the cores to a single ISA removes an important opportunity for greater heterogeneity. To take full advantage of a heterogeneous-ISA CMP, however, we must be able to migrate execution among heterogeneous cores in order to adapt to program phase changes and changing external conditions (e.g., system power state).

This paper explores migration on heterogeneous-ISA CMPs. This is non-trivial because program state is kept in an architecture-specific form; therefore, state transformation is necessary for migration. To keep migration cost low, the amount of state that requires transformation must be minimized. This work identifies large portions of program state whose form is not critical for performance; the compiler is modified to produce programs that keep most of their state in an architecture-neutral form so that only a small number of data items must be repositioned and no pointers need to be changed. The result is low migration cost with minimal sacrifice of non-migration performance.

Additionally, this work leverages binary translation to enable instantaneous migration. When migration is requested, the program is immediately migrated to a different core where binary translation runs for a short time until a function call is reached, at which point program state is transformed and execution continues natively on the new core.

This system can tolerate migrations as often as every 100 ms and still retain 95% of the performance of a system that does not do, or support, migration.
Automatic generation of hardware/software interfaces
Authors: King Myron , Dave Nirav , Arvind
Published: February 2019

Enabling new applications for mobile devices often requires the use of specialized hardware to reduce power consumption. Because of time-to-market pressure, current design methodologies for embedded applications require an early partitioning of the design, allowing the hardware and software to be developed simultaneously, each adhering to a rigid interface contract. This approach is problematic for two reasons: (1) a detailed hardware-software interface is difficult to specify until one is deep into the design process, and (2) it prevents the later migration of functionality across the interface motivated by efficiency concerns or the addition of features. We address this problem using the Bluespec Codesign Language~(BCL) which permits the designer to specify the hardware-software partition in the source code, allowing the compiler to synthesize efficient software and hardware along with transactors for communication between the partitions. The movement of functionality across the hardware-software boundary is accomplished by simply specifying a new partitioning, and since the compiler automatically generates the desired interface specifications, it eliminates yet another error-prone design task. In this paper we present BCL, an extension of a commercially available hardware design language (Bluespec SystemVerilog), a new software compiling scheme, and preliminary results generated using our compiler for various hardware-software decompositions of an Ogg Vorbis audio decoder, and a ray-tracing application.
Region scheduling
Authors: Lee Min , Schwan Karsten
Published: February 2019

The performance of modern many-core platforms strongly depends on the effectiveness of using their complex cache and memory structures. This indicates the need for a memory-centric approach to platform scheduling, in which it is the locations of memory blocks in caches rather than CPU idleness that determines where application processes are run. Using the term 'memory region' to denote the current set of physical memory pages actively used by an application, this paper presents and evaluates region-based scheduling methods for multicore platforms. This involves (i) continuously and at runtime identifying the memory regions used by executable entities, and their sizes, (ii) mapping these regions to caches to match performance goals, and (iii) maintaining region to cache mappings by ensuring that entities run on processors with direct access to the caches containing their regions. Region scheduling can implement policies that (i) offer improved performance to applications by 'unifying' the multiple caches present on the underlying physical machine and/or by 'balancing' cache usage to take maximum advantage of available cache space, (ii) better isolate applications from each other, particularly when their performance is strongly affected by cache availability, and also (iii) take advantage of standard scheduling and CPU-based load balancing when regioning is ineffective. The paper describes region scheduling and its system-level implementation and evaluates its performance with micro-benchmarks and representative multi-core applications. Single applications see performance improvements of up to 15% with region scheduling, and we observe 40% latency improvements when a platform is shared by multiple applications. Superior isolation is shown to be particularly important for cache-sensitive or real-time codes.
On the March of Time and the Meaning of Days
Authors: Stafford Tom , Petter Stacie
Published: February 2019

As of this issue, The DATA BASE for Advances in Information Systems marks its 50th year of publication. We are minded to introspect, then, on what it means to have been here for 50 years. For some, it means that this journal came to be in the year that astronauts first landed on the moon; that sounds like a very modern occurrence, but having transpired in 1969, it was literally a half century ago. That is 18,250 days, or 2,607 weeks, or 599 months, or, of course, one half of a century.

Century - the Latin root of which connotes groups of 100; half of 100 being fifty, and that being a darned large number in some respects, but in others very small. It depends on point of view, as the physicist Einstein (1921) would have put it. When you are moving at great speeds, time seems to pass more slowly (as compared to the perceptions of a less-fast moving observer). Time and its passage are a subjective perception of the perceiver, even outside of the physics of relativity (Evans, 2005). As Carol Saunders once speculated in a closing essay during her time at MIS Quarterly, it only seems like yesterday that we came to be a field of inquiry in Management Information Systems, and we could consider ourselves in the geological scheme of time to be very young indeed (Saunders, 2007). On the other hand, for those busily engaged in the fast-moving activities of publishing a journal like ours, time flies in different ways when we consider how long significant landmarks of the field of Management Information Systems have been in place (as has this journal, for a similar period of time). It was just yesterday, and it has been forever. We only just took Volume 48, Number 1 to press, it seems, and here we are at 50(1)! Time is in the Einsteinian details.
Twenty Anecdotes in Search of a Theme
Authors: Niederman Fred
Published: February 2019

This article offers a detailed history of the evolution of ACM SIGMIS from its origins before it was even called SIGMIS. Understanding the past and the origins of SIGMIS is useful to understand how the publication that we know as The DATA BASE for Advances in Information Systems developed. Furthermore, by examining the past and critical points in this history of the SIG and publication, it is possible to consider opportunities for the future.