bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulse-echo acoustic properties evaluation method using high-frequency transducer
Authors: Li Zhangjian , Han Zhile , Jian Xiaohua , Shao Weiwei , Jiao Yang , Cui Yaoyao
Published: June 2020

The quantitative measurement of acoustic properties is indispensable for many applications. The realization of devices for the evaluation of acoustic properties with higher accuracy and lower error is of great importance. Moreover, the ability to obtain the high-frequency acoustic characteristics of materials is also highly desirable. In this research, the pulse echo method is applied to measure a material’s acoustic parameters, using a miniature transducer with a center frequency of 42.9 MHz. For this method, only one transducer is needed, and the measurement system is simple. Acoustic parameter calculation methods for three types of materials are studied, and the corresponding experiments are conducted. The experimental results show that the sound velocity of water is 1508.8 m s−1, and its attenuation coefficient is 0.981 dB mm−1; the results for liquid paraffin give results of 1386.8 m s−1 and 2.35 dB mm−1, respectively. With reference to polymer materials, thermoplastic polyurethane (TPU) thin film has a sound velocity of 1987.2 m s−1 and an attenuation of 37.1 dB mm−1, and polyimide thin film has a sound velocity of 2142.3 m s−1 and an attenuation of 25 dB mm−1. In terms of ceramics, the sound velocity of PZT-5H 3203HD is 4804.2 m s−1, and its attenuation is 1.71 dB mm−1; 96% alumina ceramic has a sound velocity of 9924.9 m s−1 and its attenuation 1.18 dB mm−1. All results pertaining to sound velocity agree well with those reported in previous works. The measured attenuation coefficients at high frequency are also in good agreement with the experimental data. All experimental results validate the feasibility, effectiveness, convenience, and accuracy of this method.
First principles study of post-boron carbide phases with icosahedra broken*
Authors: Chen Ming-Wei , Liang Zhao , Liu Mei-Ling , Pramod Kumar Uppalapati , Liu Chao , Liang Tong-Xiang
Published: June 2020

Boron carbide (B4C) is a rhombic structure composed of icosahedra and atomic chains, which has an important application in armored materials. The application of B4C under super high pressure without failure is a hot spot of research. Previous studies have unmasked the essential cause of B4C failure, i.e., its structure will change subjected to impact, especially under the non-hydrostatic pressure and shear stress. However, the change of structure has not been clearly understood nor accurately determined. Here in this paper, we propose several B4C polymorphs including B4C high pressure phases with non-icosahedra, which are denoted as post-B4C and their structures are formed due to icosahedra broken and may be obtained through high pressure and high temperature (HPHT). The research of their physical properties indicates that these B4C polymorphs have outstanding mechanical and electrical properties. For instance, aP10, mC10, mP20, and oP10-B4C are conductive superhard materials. We hope that our research will enrich the cognition of high pressure structural deformation of B4C and broaden the application scope of B4C.
Study of optical clocks based on ultracold 171Yb atoms*
Authors: Ai Di , Qiao Hao , Zhang Shuang , Luo Li-Meng , Sun Chang-Yue , Zhang Sheng , Peng Cheng-Quan , Qi Qi-Chao , Jin Tao-Yun , Zhou Min , Xu Xin-Ye
Published: June 2020

The optical atomic clocks have the potential to transform global timekeeping, relying on the state-of-the-art accuracy and stability, and greatly improve the measurement precision for a wide range of scientific and technological applications. Herein we report on the development of the optical clock based on 171Yb atoms confined in an optical lattice. A minimum width of 1.92-Hz Rabi spectra has been obtained with a new 578-nm clock interrogation laser. The in-loop fractional instability of the 171Yb clock reaches 9.1 × 10−18 after an averaging over a time of 2.0 × 104 s. By synchronous comparison between two clocks, we demonstrate that our 171Yb optical lattice clock achieves a fractional instability of

4.60
×

10

−
16

/

τ

.
Asymmetric dynamic behaviors of magnetic domain wall in trapezoid-cross-section nanostrip*
Authors: Ma Xiao-Ping , Piao Hong-Guang , Yang Lei , Kim Dong-Hyun , You Chun-Yeol , Pan Liqing
Published: June 2020

Field-driven magnetic domain wall propagation in ferromagnetic nanostrips with trapezoidal cross section has been systematically investigated by means of micromagnetic simulation. Asymmetric dynamic behaviors of domain wall, depending on the propagation direction, were observed under an external magnetic field. When the domain walls propagate in the opposite direction along the long axis of the nanostrip, the Walker breakdown fields as well as the average velocities are different. The asymmetric landscape of demagnetization energies, which arises from the trapezoidal geometry, is the main origin of the asymmetric propagation behavior. Furthermore, a trapezoid-cross-section nanostrip will become a nanotube if it is rolled artificially along its long axis, and thus a two-dimensional transverse domain wall will become a three-dimensional one. Interestingly, it is found that the asymmetric behaviors observed in two-dimensional nanostrips with trapezoidal cross section are similar with some dynamic properties occurring in three-dimensional nanotubes.
Evolution of electrical and magnetotransport properties with lattice strain in La0.7Sr0.3MnO3 film*
Authors: Ling Zhi-Bin , Zhang Qing-Ye , Yang Cheng-Peng , Li Xiao-Tian , Liang Wen-Shuang , Wang Yi-Qian , Yang Huai-Wen , Sun Ji-Rong
Published: June 2020

In this paper, we investigate the effects of lattice strain on the electrical and magnetotransport properties of La0.7Sr0.3MnO3 (LSMO) films by changing film thickness and substrate. For electrical properties, a resistivity upturn emerges in LSMO films, i.e., LSMO/STO and LSMO/LSAT with small lattice strain at a low temperature, which originates from the weak localization effect. Increasing film thickness weakens the weak localization effect, resulting in the disappearance of resistivity upturn. While in LSMO films with a large lattice strain (i.e., LSMO/LAO), an unexpected semiconductor behavior is observed due to the linear defects. For magnetotransport properties, an anomalous in-plane magnetoresistance peak (pMR) occurs at low temperatures in LSMO films with small lattice strain, which is caused by two-dimensional electron gas (2DEG). Increasing film thickness suppresses the 2DEG, which weakens the pMR. Besides, it is found that the film orientation has no influence on the formation of 2DEG. While in LSMO/LAO films, the 2DEG cannot form due to the existence of linear defects. This work can provide an efficient way to regulate the film transport properties.
Grain size and structure distortion characterization of α-MgAgSb thermoelectric material by powder diffraction*
Authors: Li Xiyang , Zhang Zhigang , He Lunhua , Avdeev Maxim , Ren Yang , Zhao Huaizhou , Wang Fangwei
Published: June 2020

Nanostructuring, structure distortion, and/or disorder are the main manipulation techniques to reduce the lattice thermal conductivity and improve the figure of merit of thermoelectric materials. A single-phase α-MgAgSb sample, MgAg0.97Sb0.99, with high thermoelectric performance in near room temperature region was synthesized through a high-energy ball milling with a hot-pressing method. Here, we report the average grain size of 24–28 nm and the accurate structure distortion, which are characterized by high-resolution neutron diffraction and synchrotron x-ray diffraction with Rietveld refinement data analysis. Both the small grain size and the structure distortion have a contribution to the low lattice thermal conductivity in MgAg0.97Sb0.99.
Quantized vortices in spinor Bose–Einstein condensates with time–space modulated interactions and stability analysis*
Authors: Yao Yu-Qin , Li Ji
Published: June 2020

The three-component Gross–Pitaevskii equation with an angular momentum rotational term can be served as a model to study spinor Bose–Einstein condensates (BECs) with time–space modulated interactions. Vortex solutions of the spinor BECs with spatiotemporally modulated interactions are worked out by similarity transformation. Theoretical analysis and numerical simulation of vortex states are demonstrated. Stable vortex states are obtained by adjusting the frequency of the external potential and the spatiotemporally modulated interaction.
Fluctuations of the magnetization for Ising models on Erdős–Rényi random graphs—the regimes of small p and the critical temperature
*
Authors: Kabluchko Zakhar , Löwe Matthias , Schubert Kristina
Published: June 2020

We continue our analysis of Ising models on the (directed) Erdős–Rényi random graph. This graph is constructed on N vertices and every edge has probability p to be present. These models were introduced and first studied by Bovier and Gayrard (1993 J. Stat. Phys.
72 643–64) and further analyzed by the authors in a previous note, in which we consider the case of p = p(N) satisfying p
3
N
2 → ∞ and β < 1. In the current note we prove a quenched central limit theorem for the magnetization for p satisfying pN → ∞ in the high-temperature regime β < 1. We also show a non-standard central limit theorem for p
4
N
3 → ∞ at the critical temperature β = 1. For p
4
N
3 → 0 we obtain a Gaussian limiting distribution for the magnetization. Finally, in the critical regime p
4
N
3 → c the limiting distribution for the magnetization contains a Gaussian component as well as a

e

−

x

4

-term. Hence, at β = 1 we observe a phase transition in p for the fluctuations of the magnetization.
Zinc oxide doped arylidene based polyketones hybrid nanocomposites for enhanced biological activity
Authors: Almehmadi Samar J , Alamry Khalid A , Elfaky M A , Alqarni Sara , Samah J A , Hussein Mahmoud A
Published: June 2020

The application of Friedel-Craft reactions has been extended to the biological systems. Recently, these reactions have led to the generation of a new set of polyketones (PKa-c) along with the related zinc oxide doped nanocomposites (ZnOPKd-f). Prior to the process of polymerization, these newly synthesized monomers were subjected to spectral analysis to reveal their chemical structures. Three arylidene monomers based on three different moieties including benzylidene, thiophenylidene and furfurylidene were synthesized through a direct condensation reaction. These monomers interacted with terephthaloyl chloride in the presence of anhydrous AlCl3 in organic methanol solvent via Friedel–Crafts reaction, to produce the desired PKa-c. Further, a series of ZnOPKd-f nanocomposites were fabricated using a 10% loading of ZnO nanoparticles throughout the same experimental procedure as required to develop PKa-c. A common characterization tool was employed to prove the structures for PKa-c and its related ZnOPKd-f TGA results established enhancement in the thermal behavior of PK a-c with the different structures. PDT
max
values showed that all the polymers had a similar identity which appeared in the range from 578° to 630°. Additionally, the morphological properties were assessed by using scanning electron microscopy which revealed the formation of ZnOPKd-f and ZnO nanoparticles. The latter are spherical particles, ranging in of 29 to 223 nm loaded on the polymer surface. The TEM images illustrated the uniform distribution of the ZnO nanoparticles in the polymer matrix. The ZnOPKd-f nanocomposites were examined for their antimicrobial activity against variable kinds of bacteria and fungi. Based on the biological screening, it was observed that the ZnOPKd-f nanocomposite materials can be used as moderate antibacterial and antifungal agents.
Electrical and microstructural properties of Ta-C thin films for metal gate
Authors: Aihaiti Litipu , Tuokedaerhan Kamale , Sadeh Beysen , Zhang Min , Xiang Qian Shen , Mijiti Abuduwaili
Published: June 2020

Carbon rich Nano-crystalline grain size tantalum carbide (Ta-C) thin films were prepared by non- reactive simultaneously dual magnetron sputtering. The main purpose of the current work was to investigate the influence of deposition method, deposition power, film thickness and annealing temperature on structural, surface morphology and electrical resistivity of TaC thin films. The experimental result shows that the growth rate of film was about 6.7 nm min−1 and films are growth like spherical structure. The atomic percentage of elements in the films were very sensitive to the deposition power, which even if the small amount of increases in the deposition power of Ta lead the increase of Ta content. However, a small change in Ta percentage did not result in a change in film structure and surface morphology. Annealing temperature did not cause structural changes in the films, but lead small changes in the grain size (range from 7.0 to 9.1 nm) and surface roughness. Resistivity variation of deposited TaC films on the annealing temperature shows random behavior which may cause by the deposition method. Nevertheless, the resistivity of the film decreases first and then increases when the thickness increases from 79.2 nm to 134 nm. Minimum resistivity of film appears at the thickness of 79.2 nm, about 235.2 μΩ.cm. In the end, deposited TaC thin films shows good thermal stability and low enough resistivity for gate electrode application.
Inquiry-led labs engage students
Authors: Allen Michael
Published: June 2020

Lab sessions that are designed to emphasize and teach experimentation skills – rather than to reinforce lecture content – improve student attitudes towards experimental physics.
Moving forward together
Authors: Charles Tessa
Published: June 2020

In the run-up to a pivotal announcement on the future of particle physics in Europe, Tessa Charles urges backers of rival colliders to unite around whichever project gets the go-ahead
Critical research hit by COVID-19
Authors: Gwynne Peter , Banks Michael
Published: June 2020

Major labs have shut their doors in response to the worldwide lockdown, but a few remain open and in some cases are carrying out critical work related to the COVID-19 pandemic, as Peter Gwynne and Michael Banks report
Serendipity in action
Authors: McKenzie James
Published: June 2020

Accidental discoveries lie at the heart of many technological innovations. James McKenzie runs through his favourites
Critical clarification
Authors: Close Frank
Published: June 2020

In response to Margaret Harris’ review “A critical mass of secrets” (February 2020) of Frank Close’s latest book Trinity: the Treachery and Pursuit of the Most Dangerous Spy in History, which tells the story of physicist and committed communist Klaus Fuchs.
Pitch of birdsong is determined by body size
Authors: Jarman Sam
Published: June 2020

The characteristics of the whitetipped plantcutter’s song are directly linked to its body size, a new study shows. Physicists and ornithologists in Argentina and Germany have discovered the relationship through a detailed analysis of recordings and museum specimens of the birds.
The geometry of degenerations of Hilbert schemes of points
Authors: Gulbrandsen Martin , Halle Lars , Hulek Klaus , Zhang Ziyu
Published: June 2020

Given a strict simple degenerationf:X→Cf \colon X\to Cthe first three authors previously constructed a degenerationIX/Cn→CI^n_{X/C} \to Cof the relative degreennHilbert scheme of00-dimensional subschemes. In this paper we investigate the geometry of this degeneration, in particular when the fibre dimension offfis at most22. In this case we show thatIX/Cn→CI^n_{X/C} \to Cis a dlt model. This is even a good minimal dlt model iff:X→Cf \colon X \to Chas this property. We compute the dual complex of the central fibre(IX/Cn)0(I^n_{X/C})_0and relate this to the essential skeleton of the generic fibre. For a type II degeneration of K3 surfaces we show that the stackIX/Cn→C{\mathcal I}^n_{X/C} \to Ccarries a nowhere degenerate relative logarithmic22-form. Finally we discuss the relationship of our degeneration with the constructions of Nagai.
Mitochondria regulate intestinal stem cell proliferation and epithelial homeostasis through FOXO
Authors: Zhang Fan , Pirooznia Mehdi , Xu Hong
Published: June 2020

Deficiencies in electron transport chain complexes increase the activity of FOXO transcription factor in Drosophila midgut stem cells, which impairs stem cell proliferation and enterocyte specification.
A Systematic Review of Wellness in Plastic Surgery Training
Authors: Grome Luke J , Reul Ross M , Agrawal Nikhil , Abu-Ghname Amjed , Winocour Sebastian , Buchanan Edward P , Maricevich Renata S , Reece Edward M
Published: June 2020

Background

Physician and resident wellness has been increasingly emphasized as a means of improving patient outcomes and preventing physician burnout. Few studies have been performed with a focus on wellness in plastic surgery training.

Objectives

The aim of this study was to systematically review what literature exists on the topic of wellness in plastic surgery training and critically appraise it.

Methods

A PubMed search was performed to identify journal articles related to wellness in plastic surgery residency. Seventeen studies (6 cohort and 11 cross-sectional) met inclusion criteria and were appraised with the Newcastle-Ottawa Quality Assessment Scale (NOQAS) to determine the quality of the studies based on selection, comparability, and outcome metrics.

Results

Critical assessment showed that the studies were highly variable in focus. Overall, the quality of the data was low, with an average NOQAS score of 4.1. Only 2 studies focused on plastic surgery residents, examining work hours and social wellness, respectively; they were awarded NOQAS scores of 3 and 4 out of 10.

Conclusions

The results of this systematic review suggest that little research has been devoted to wellness in surgery training, especially in regard to plastic surgery residents, and what research that has been performed is of relatively low quality. The available research suggests a relatively high prevalence of burnout among plastic surgery residents. Evidence suggests some organization-level interventions to improve trainee wellness. Because outcomes-based data on the effects of such interventions are particularly lacking, further investigation is warranted.
Effect of Haemophilus influenzae Type b and 13-Valent Pneumococcal Conjugate Vaccines on Childhood Pneumonia Hospitalizations and Deaths in Botswana
Authors: Congdon Morgan , Hong Hwanhee , Young Rebecca R , Cunningham Coleen K , Enane Leslie A , Arscott-Mills Tonya , Banda Francis M , Chise Mamiki , Motlhatlhedi Keneilwe , Feemster Kristen , Patel Sweta M , Boiditswe Sefelani , Leburu Tiroyaone , Shah Samir S , Steenhoff Andrew P , Kelly Matthew S
Published: June 2020

Background

Globally, pneumonia is the leading cause of death among children. Few data exist regarding the effect of Haemophilus influenzae type b (Hib) vaccine and 13-valent pneumococcal conjugate vaccine (PCV-13) on the burden of childhood pneumonia in African settings.

Methods

We collected data on children aged 1 to 59 months at 3 hospitals in Botswana. Hib vaccine and PCV-13 were introduced in Botswana in November 2010 and July 2012, respectively. We compared pneumonia hospitalizations and deaths prevaccine (January 2009 to October 2010) with postvaccine (January 2013 to December 2017) using seasonally adjusted, interrupted time-series analyses.

Results

We identified 6943 pneumonia hospitalizations and 201 pneumonia deaths. In the prevaccine period, pneumonia hospitalizations and deaths increased by 24% (rate, 1.24; 95% CI, .94–1.64) and 59% (rate, 1.59; 95% CI, .87–2.90) per year, respectively. Vaccine introduction was associated with a 48% (95% CI, 29–62%) decrease in the number of pneumonia hospitalizations and a 50% (95% CI, 1–75%) decrease in the number of pneumonia deaths between the end of the prevaccine period (October 2010) and the beginning of the postvaccine period (January 2013). During the postvaccine period, pneumonia hospitalizations and deaths declined by 6% (rate, .94; 95% CI, .89–.99) and 22% (rate, .78; 95% CI, .67–.92) per year, respectively.

Conclusions

Pneumonia hospitalizations and deaths among children declined sharply following introduction of Hib vaccine and PCV-13 in Botswana. This effect was sustained for more than 5 years after vaccine introduction, supporting the long-term effectiveness of these vaccines in preventing childhood pneumonia in Botswana.
Combined Biologic and Immunomodulatory Therapy is Superior to Monotherapy for Decreasing the Risk of Inflammatory Bowel Disease-Related Complications
Authors: Targownik Laura E , Benchimol Eric I , Bernstein Charles N , Singh Harminder , Tennakoon Aruni , Zubieta Antonio Aviña , Coward Stephanie , Jones Jennifer , Kaplan Gilaad G , Kuenzig M Ellen , Murthy Sanjay K , Nguyen Geoffrey C , Peña-Sánchez Juan Nicolás
Published: June 2020

Background and Aims

The combination of infliximab and azathioprine is more efficacious than either therapy alone for Crohn’s disease [CD] and ulcerative colitis [UC]. However, it is uncertain whether these benefits extend to real-world clinical practice and to other combinations of biologics and immunomodulators.

Methods

We collected health administrative data from four Canadian provinces representing 78 413 patients with inflammatory bowel disease [IBD] of whom 11 244 were prescribed anti-tumour necrosis factor [anti-TNF] agents. The outcome of interest was the first occurrence of treatment failure: an unplanned IBD-related hospitalization, IBD-related resective surgery, new/recurrent corticosteroid use or anti-TNF switch. Multivariable Cox proportional hazards modelling was used to assess the association between the outcome of interest and receiving combination therapy vs anti-TNF monotherapy. Multivariable regression models were used to assess the impact of choice of immunomodulator or biologic on reaching the composite outcome, and random effects generic inverse variance meta-analysis of deterministically linked data was used to pool the results from the four provinces to obtain aggregate estimates of effect.

Results

In comparison with anti-TNF monotherapy, combination therapy was associated with a significant decrease in treatment ineffectiveness for both CD and UC (CD: adjusted hazard ratio [aHR] 0.77, 95% confidence interval [CI] 0.66–0.90; UC: aHR 0.72, 95% CI 0.62–0.84). Combination therapy was equally effective for adalimumab and infliximab in CD. In UC azathioprine was superior to methotrexate as the immunomodulatory agent (aHR = 1.52 [95% CI 1.02–2.28]) but not CD (aHR = 1.22 [95% CI 0.96–1.54]).

Conclusion

In an analysis of a database of real-world patients with IBD, combination therapy decreased the likelihood of treatment failure in both CD and UC.
Biochar as electron donor for reduction of N2O by Paracoccus denitrificans
Authors: Pascual Mª Blanca , Sánchez-Monedero Miguel Ángel , Cayuela María L , Li Shun , Haderlein Stefan B , Ruser Reiner , Kappler Andreas
Published: June 2020

Biochar (BC) has been shown to influence microbial denitrification and mitigate soil N2O emissions. However, it is unclear if BC is able to directly stimulate the microbial reduction of N2O to N2. We hypothesized that the ability of BC to lower N2O emissions could be related not only to its ability to store electrons, but to donate them to bacteria that enzymatically reduce N2O. Therefore, we carried out anoxic incubations with Paracoccus denitrificans, known amounts of N2O, and nine contrasting BCs, in the absence of any other electron donor or acceptor. We found a strong and direct correlation between the extent and rates of N2O reduction with BC's EDC/EEC (electron donating capacity/electron exchange capacity). Apart from the redox capacity, other BC properties were found to regulate the BC's ability to increase N2O reduction by P. denitrificans. For this specific BC series, we found that a high H/C and ash content, low surface area and poor lignin feedstocks favored N2O reduction. This provides valuable information for producing tailored BCs with the potential to assist and promote the reduction of N2O in the pursuit of reducing this greenhouse gas emissions.
Succession in epibenthic communities on artificial reefs associated with marine renewable energy facilities within a tide-swept environment
Authors: Taormina Bastien , Percheron Arthur , Marzloff Martin P , Caisey Xavier , Quillien Nolwenn , Lejart Morgane , Desroy Nicolas , Dugornay Olivier , Tancray Aurélien , Carlier Antoine
Published: June 2020

Although colonization of artificial structures by epibenthic communities is well-documented overall, our understanding of colonization processes is largely limited to low-energy environments. In this study, we monitored epibenthic colonization of different structures associated with a tidal energy test site located in a high-energy hydrodynamic environment. Using four years of image-based underwater surveys, we characterized changes through space and time in the taxonomic composition of epibenthic assemblages colonizing two kinds of artificial structures, as well as the surrounding natural habitat. Our results highlight that ecological successions followed similar trends across the two artificial habitats, but that different habitat-specific communities emerged at the end of our survey. Deployment of these artificial structures resulted in the addition of elevated and stable substrata in an environment where natural hard substrates are unstable and strongly exposed to sediment abrasion. Although epibenthic communities colonizing artificial habitats are unlikely to have reached a mature stage at the end of our survey, these supported structurally complex taxa facilitating an overall increase in local diversity. We were able to quantify how epibenthic communities can significantly vary over time in high-energy coastal environment, and our final survey suggests that the ecological succession was still in progress five years after the deployment of artificial reefs. Thus, maintaining long-term continuous survey of coastal artificial reef habitats will be key to better discriminate between long-term ecological successions and shorter-term variability.
Bifurcation analysis of a phage-bacteria interaction model with prophage induction
Authors: Ndongmo Teytsa H M , Tsanou B , Bowong S , Lubuma J M-S
Published: June 2020

A predator-prey model is used to investigate the interactions between phages and bacteria by considering the lytic and lysogenic life cycles of phages and the prophage induction. We provide answers to the following conflictual research questions: (1) what are conditions under which the presence of phages can purify a bacterial infected environment? (2) Can the presence of phages triggers virulent bacterial outbreaks? We derive the basic offspring number $\mathcal N_0$ that serves as a threshold and the bifurcation parameter to study the dynamics and bifurcation of the system. The model exhibits three equilibria: an unstable environment-free equilibrium, a globally asymptotically stable (GAS) phage-free equilibrium (PFE) whenever $\mathcal N_0<1$, and a locally asymptotically stable environment-persistent equilibrium (EPE) when $\mathcal N_0>1$. The Lyapunov–LaSalle techniques are used to prove the GAS of the PFE and estimate the EPE basin of attraction. Through the center manifold approximation, topological types of the PFE are precised. Existence of transcritical and Hopf bifurcations are established. Precisely, when $\mathcal N_0>1$, the EPE loses its stability and periodic solutions arise. Furthermore, increasing $\mathcal N_0$ can purify an environment where bacteriophages are introduced. Purposely, we prove that for large values of $\mathcal N_0$, the overall bacterial population asymptotically approaches zero, while the phage population sustains. Ecologically, our results show that for small values of $\mathcal N_0$, the existence of periodic solutions could explain the occurrence of repetitive bacteria-borne disease outbreaks, while large value of $\mathcal N_0$ clears bacteria from the environment. Numerical simulations support our theoretical results.
An adaptively enriched coarse space for Schwarz preconditioners forP1 discontinuous Galerkin multiscale finite element problems
Authors: Eikeland Erik , Marcinkowski Leszek , Rahman Talal
Published: June 2020

In this paper, we propose a two-level additive Schwarz domain decomposition preconditioner for the symmetric interior penalty Galerkin method for a second-order elliptic boundary value problem with highly heterogeneous coefficients. A specific feature of this preconditioner is that it is based on adaptively enriching its coarse space with functions created by solving generalized eigenvalue problems on thin patches covering the subdomain interfaces. It is shown that the condition number of the underlined preconditioned system is independent of the contrast if an adequate number of functions are used to enrich the coarse space. Numerical results are provided to confirm this claim.
A Comparative Study Between Conventional ICP-OES and the Innovative PLS Model-Assisted ICP-OES for the Assay of Trace Elements
Authors: Michael Adel M , Mohamed Ahmed A , Abdelaziz Yousef A , Fahmy Nesma M
Published: June 2020

Background

Inductively coupled plasma is widely used for elemental analysis with the advantage of being eco-friendly since the discharge is free of contaminants.

Objective

A rapid, novel method was developed for the quantitation of trace elements using inductively coupled plasma with optical emission spectrometry.This method has the advantage of simultaneous calibration compared to the conventional method.

Method

The assay was carried out for iron, copper, zinc, and molybdenum using the linear regression model partial least-squares.

Results

The method was optimized and validated as per the International Conference on Harmonization guidelines, showing highly accurate and precise results. The linearity range was 0.25–4 ppm for all trace elements under investigation. The method was applied for the assay of the cited elements in non-chelated and amino acid chelated multi-mineral preparations in the Egyptian market with acceptable mean percent recovery.

Conclusions

In comparison with the official method by flame emission, statistical analysis showed no significant difference with Student’s t-test and F-values.

Highlights

Inductively coupled plasma is superior as all of the elements can be measured simultaneously. The method was found to have a high degree of specificity and can be easily applied in routine elemental analysis in laboratories.
Effects of dietary corticosterone on the central adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in broiler chickens
Authors: Hu Xiyi , Cai Yuanli , Kong Linglian , Lin Hai , Song Zhigang , Buyse Johan
Published: June 2020

Glucocorticoids (GCs) induce the activation of the central adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway in birds. In this study, we aimed to investigate the effects of corticosterone (CORT) supplemented in diet on the central AMPK signaling pathway in broilers. The average daily gain was reduced by CORT treatment, and the average daily feed intake remained unchanged. Plasma glucose, triglyceride, total cholesterol, and CORT contents were increased by CORT administration. In addition, CORT treatment decreased the relative weights of heart, spleen, and bursa and increased the relative weights of liver and abdominal fat. The glycogen contents in the liver and breast muscle were higher in the chicks treated with CORT. CORT treatment upregulated the gene expression of mammalian target of rapamycin, glucocorticoid receptor, AMPKα2, neuropeptide Y(NPY), liver kinase B1 (LKB1), AMPKα1, and fatty acid synthase in the hypothalamus. Moreover, CORT treatment increased the protein levels of acetyl-coenzyme A carboxylase (ACC) phosphorylation and total AMPK and phosphorylated AMPK in the hypothalamus. Hence, CORT administration in the diet activated the LKB1-AMPK-NPY/ACC signaling pathway in the hypothalamus of broiler.
Mosquitoes (Diptera: Culicidae) From the Southwestern Brazilian Amazon: Liberdade and Gregório Rivers
Authors: Hutchings Rosa Sá Gomes , Hutchings Roger William , Menezes Isis Sá , Sallum Maria Anice Mureb
Published: June 2020

The mosquito community from remote locations toward the southern border of the Brazilian State of Amazonas, in four localities along the Liberdade and Gregório Rivers, was sampled using CDC and Malaise traps, complemented with net sweeping and immature collections. During May 2011, 190 collections yielded 13,012 mosquitoes, from 15 genera and 112 different species, together with 10 morphospecies, which may represent new undescribed taxa. Among the species collected, there are two new geographical distribution records for the State of Amazonas. Culex, the most abundant genus, also had the highest number of species. Both Aedes and Uranotaenia had the second highest number of species, although they were the second and seventh most abundant, respectively. The most abundant species were Aedes (Ochlerotatus) fulvus (Wiedemann), Aedes (Ochlerotatus) nubilus (Theobald), Culex (Culex) mollis Dyar & Knab, Nyssorhynchus (Nyssorhynchus) oswaldoi sensu lato, Culex (Melanoconion) pedroi Sirivanakarn & Belkin, and Culex (Melanoconion) gnomatos Sallum, Hutchings & Ferreira. The epidemiological implications of mosquito species are discussed and compared with other mosquito inventories from the Amazon region. These results represent the first standardized mosquito inventories of the Liberdade and Gregório Rivers, with the identification of 112 species and 10 morphospecies, within the municipalities of Ipixuna and Eirunepé, from which we have only few records in the published literature.
Competition Law in Developing Countries
Authors: Cheng Thomas K
Published: June 2020

This book explores the relationship between competition law and economic development, which takes on growing importance as more and more developing countries have adopted competition law in recent years. The work tackles two principal questions. The first is whether competition law enforcement promotes growth, which helps to determine how seriously developing countries should enforce their competition laws. The second is how developing countries should craft their competition law rules in light of the need to incorporate development concerns, the need to reflect the special economic characteristics of developing countries, and the need to improve the administrability of competition law rules to suit the enforcement capacity of developing country authorities.
Introduction
Authors: Cheng Thomas K
Published: June 2020

This introductory chapter provides an overview of competition law in developing countries. Following the proliferation of competition law across the globe in the last few decades, developing countries now comprise a majority of the jurisdictions that have in place a competition law. At least in terms of the language of the main substantive provisions on restrictive agreements and abuse of dominance, many of these new jurisdictions have chosen to follow the U.S. and the EU models. However, the proliferation of competition law regimes has given rise to a fear of balkanization of competition law enforcement and an excessive compliance burden for businesses, especially multi-national corporations. Out of this fear grew the rallying cry for convergence. The implicit assumption behind the drive for convergence is that there exists one or a handful of models of competition law enforcement that are suitable for most countries across the globe, to which new jurisdictions are expected to converge. Some commentators and officials have challenged this, questioning whether the legal principles regulating markets in the industrialized economies of the United States and the European Union can be transplanted directly to developing countries. Apart from the need to tailor to the local economic environment, competition law must contribute to the economic growth and development agenda of developing countries.
Competition Law Enforcement and Economic Development
Authors: Cheng Thomas K
Published: June 2020

This chapter addresses the need for competition law enforcement to pay separate attention to the pursuit of development objectives. The importance of the pursuit of development objectives has been underscored by the incorporation of poverty alleviation and inclusive growth as the core objectives of the African Competition Forum, which includes countries that are in most dire need for economic development. Once it is established that competition law needs to take into account development objectives, it remains to be determined how it should be done. Aside from paying heed to the welfare of the poor, competition law enforcement should incorporate development considerations by shifting enforcement priorities to focus on sectors that will make the greatest contribution to poverty reduction and sectors that are most important to meeting development needs. The agricultural sector is a prime example. Agriculture affects both the expenditure and, in many instances, the income of the poor. Apart from agriculture, the competition authority can also pay particular attention to anticompetitive practices that hinder or stifle entrepreneurial opportunities for the poor. Given the developmental significance of meeting the basic needs of food security, healthcare, education, access to clean water and sanitation, and energy, developing country competition authorities should also focus on these sectors.
Abuse of Dominance
Authors: Cheng Thomas K
Published: June 2020

This chapter studies possible approaches to abuse of dominance enforcement in developing countries. Before dealing with the substantive rules, however, there are a number of questions that need to be addressed first. The first is whether developing countries should prioritize enforcement against abuse of dominance at all. Some have argued that developing country authorities should focus on cartel cases because cartels inflict the greatest harm on consumers and are easier to prosecute. However, such an approach would be mistaken because abuse of dominance can be an important source of distortion of competition in developing countries, especially in those sectors in which a former state-owned monopoly operates. The second one is whether there are any special economic characteristics in developing countries that render them more susceptible to abuse of dominance. It turns out there are a number of them, including the natural tendency for markets in developing countries toward market dominance, poorly developed financial markets, and the heavy state presence in the economy. The chapter then looks at issues that require special attention by developing country authorities when defining the market, assessing market power, and analyzing various kinds of abuses such as unilateral refusal to deal, predatory pricing, excessive pricing, and buyer power issues.

Dominant position

Abuse of dominant position, affecting trade

Basic principles of competition law
Enforcement
Authors: Cheng Thomas K
Published: June 2020

This chapter explores the myriad difficulties and obstacles for competition law enforcement in developing countries and suggests possible solutions to some of these difficulties. Competition culture is generally lacking in developing countries. In addition, developing country authorities often face a particularly challenging enforcement environment due to past policy failures by the government, especially in the context of privatization. Another major external impediment to effective competition law enforcement is the lack of political will on the part of the government to enforce the law. The chapter also looks at the lack of authority independence, financial resources, enforcement powers, availability of data, and judicial expertise. Institutional design can have a bearing on setting of enforcement priorities. Poor institutional design may take flexibility away from the authority and make it impossible for the authority to set enforcement priorities. Apart from enforcement, however, another very important part of an authority’s work is advocacy. It is through advocacy with the general public that the authority can hope to build a competition culture. Meanwhile, it is through advocacy with the government that the authority can ensure government policies do not create intractable competition problems that are beyond the capability of the authority to solve. The chapter then considers the benefits and limitations of a regional approach to competition law enforcement.

Enforcement and procedure
Conclusion
Authors: Cheng Thomas K
Published: June 2020

This concluding chapter argues that competition law enforcement is doubly demanding for authorities in developing countries that are often strapped for cash, bereft of experienced personnel, and subject to political interferences. Limited funding means that developing country authorities must select their cases carefully and set their enforcement priorities judicially to maximize their impact on consumer welfare and to help garner public support. Moreover, the lack of enforcement capacity, especially the ability to undertake complex economic analysis, would require a simplification of the legal rules. Ultimately, it is ill-advised for developing countries to transplant legal principles wholesale from the advanced jurisdictions without considering whether the original bases and justifications for these principles are applicable to their domestic environment. This is not to say that developing countries must diverge from the advanced jurisdictions in every instance. There may be situations where the same legal rule can equally apply in developing countries. Whatever decision developing countries make with respect to the transplantation of competition law, be it convergence and divergence, it should be judicious and informed.
Arbitral Institutions
Authors: Oda Hiroshi
Published: June 2020

This chapter focuses on arbitral institutions. After the new Law on Arbitration came into effect on 1 September 2016, permanent arbitral institutions are to be established in accordance with the amended Law. The problem was what was going to happen to the existing arbitral institutions after the Arbitral Reform. The Law provides that existing arbitral institutions that do not fulfil the requirement of the Law and thus did not receive a licence are not entitled to administer arbitration. On 1 November 2017, a vast majority of the existing arbitral institutions failed to meet the requirements of the Law on Arbitration, namely the requirement that they be set up by a non-commercial organisation, and ceased operation. There are now only two permanent arbitral institutions in Russia. Chapter 9 of the Law on Arbitration accommodates detailed rules on the organisational aspects of permanent arbitral institutions. This is different from the system before the 2015 Reform, which had almost no regulation in this respect. Chapter 9 is applicable not only to arbitral institutions which handle domestic arbitration, but also to international commercial arbitration. The chapter then looks at the institutional rules of arbitration as well as the rules on the administration of arbitration.
Impartiality and Independence of Arbitrators and Arbitral Institutions
Authors: Oda Hiroshi
Published: June 2020

This chapter assesses the concept of impartiality and independence. The Law on International Commercial Arbitration provides that the potential candidate for the appointment of an arbitrator must disclose any circumstances that may cause a well-grounded doubt regarding his impartiality or independence in writing. In cases where the competent court, appoints an arbitrator, in the absence of the agreement between the parties, the court must ensure that an independent and impartial arbitrator is appointed. Independence and impartiality in Russia are not issues limited to arbitrators. The core of the issue is the independence and impartiality of arbitral institutions.Independence is understood to be an objective state of an arbitrator in the absence of any relationship with a person or circumstances which affect the arbitrator’s decision. Impartiality means that the arbitrator is not, directly or indirectly, interested in the outcome of the case and does not have preference or other prejudice in relation to a party, his representative, expert, or witness. Russian courts have ruled on the impartiality and independence of arbitrators as well as arbitral institutions in an inconsistent manner. In 2010, the International Court of Commercial Arbitration (MKAS) adopted a document entitled Rules on Impartiality and Independence of Arbitrators. Apart from being a guidance for arbitrators and the parties, this document is expected to give guidance to the courts when facing an application for setting aside an award and the refusal of recognition and enforcement of awards of international commercial arbitration on the grounds of the absence of impartiality and independence.
Setting Aside of Awards
Authors: Oda Hiroshi
Published: June 2020

This chapter covers the setting aside of arbitral awards. Arbitral awards can be set aside only by the court of the place of arbitration. Courts of the Russian Federation have exclusive jurisdiction in deciding on applications for setting aside of arbitral awards made in the Russian Federation. Grounds for setting aside of awards are common with the grounds for refusal of recognition and enforcement of foreign awards. Breach of public order is one of the frequently quoted grounds by Russian parties. Setting aside of awards is an area where the relationship between the state courts and arbitration is demonstrated in a concentrated manner. The chapter, after looking at the statutory provisions, will analyse a series of decisions of the court on setting aside of arbitral awards. Russian parties which lost arbitration often applies to the court in the hope of having the award been set aside. There have been some controversial decisions of Russian courts in this respect.
The Enforcement of Arbitral Awards
Authors: Oda Hiroshi
Published: June 2020

This concluding chapter explores the enforcement of arbitral awards. There are two primary laws relevant to the recognition and enforcement of arbitral awards of international commercial arbitration in Russia: the Law on International Commercial Arbitration of 1993 and the Code of Commercial Court Procedure of 2002. The former has the basic provision on the recognition and enforcement of awards and the grounds for refusal, while the latter provides for the procedural aspects of recognition and enforcement of arbitral awards. It is an established principle of international commercial arbitration that in deciding whether enforcement of awards is allowed or not, courts are not entitled to review the case on its merits. However, Russian judges are not always aware of this fundamental rule, or do not comply with it. The chapter then looks at the grounds for the refusal of recognition and enforcement of arbitral awards and the way Russian courts interpret these grounds. Particularly important is the understanding of public order by Russian courts. Finally, the practice of ‘Russian Torpedo’ is discussed.