bluuebunny/crossref_metadata_2025 huggingface dataset:
The traffic performance of the wheeled carrying liquid materials study
Authors: Plavelsky E P , Sharapov R R , Plavelsky A E
Published: February 2020

A feature of the wheeled vehicles capable of carrying liquid materials is the presence of the external disturbances in the form of interaction with the roadbed. This applies to peculiar transport vehicles, carrying liquid materials considered as non-Newtonian fluid. The internal disturbances in the form of the liquid material free surface interaction is the presence of the external disturbances in the form of interaction with the roadbed. Internal disturbances in the form of the wheeled concrete transport machine working vessel fluid free surface interaction should also be taken into account. The article describes the first part of the task - the interaction of the system with the roadbed. The simplest form of the system motion equations with rolling is in the accompanying coordinate system when written in the form of equations in quasi-coordinates. Based on the apparatus of nonholonomic mechanics, M.V. Keldysh built the theory of the rolling wheels with an elastic tire. Under certain assumptions, the above-mentioned theory in the article is extended to the case of curvilinear motion. These equations are represented as a system of first-order equations convenient for numerical solution.
Ultrasonic welding aluminium alloy 7075 to titanium alloy Ti-6Al-4V: parameter optimization and mechanical property
Authors: Shibo Liu , Guijun Bi , Yijun Man , Xianchong Sun , Yang Lee Bing , Dayou Pan , Kweng Cheng Chek
Published: February 2020

The demand for lightweight materials has increased for automobile and airplane industry. Traditional fusion welding techniques always generate brittle intermetallic compound (IMC). Ultrasonic spot welding (USW) is a promising technique to joint dissimilar metals and suppress IMC formation. This study aims to investigate the role of process parameters as well as surface roughness on the joint shear strength of titanium alloy Ti-6Al-4V and aluminium alloy 7075. Process parameters namely penetration depth, welding time and pressure were varied and the joint shear strength obtained was investigated. Results obtained were indicative that penetration depth and pressure should be used with highest values and surface roughness with lowest. In summary, optimal parameters are USW penetration depth 0.7mm, welding time 1.8s, pressure 0.7 MPa and surface roughness of AA7075 0.1457 Ra µm and Ti-6Al-4V 0.0651 Ra µm (both ground by P1200 SiC paper) in this study.
Design of Vacuum Pump Control System for Negative Pressure Shale Shaker Based on PLC
Authors: Yang Xiangqian , Zhou Chao , Guo Hua , Zheng Qinghua
Published: February 2020

In order to improve the solid-liquid separation effect of drilling fluid in drilling operation, a new type of negative pressure vibrating screen was developed. The vacuum pump is its main component. At present, the degree of vacuum has a significant impact on the screening effect and working efficiency of the negative pressure vibrating screen. The value of the vacuum is based on experience, the setting parameters are not adjustable, or changing via the manual adjustment, and the control precision and the degree of intelligence are low. The system of the negative pressure vibrating screen vacuum pump control was designed with the moisture content of the filter cake as the controlled variable. The mathematical model between the moisture content and the vacuum degree of the filter cake was established. The fuzzy PID was studied by using Siemens S7-300 PLC as the controller. Control the law, build a control system based on the inverter as the actuator, and control the vacuum degree according to the drilling fluid quality in real time. The field application shows that the steady state error of the system is 11.1%, which meets the drilling operation requirements.
3D Numerical Simulation of Expendable Bathythermograph Probe Dropping
Authors: Lv Wenlong , Wang Yongjie , Li Fang
Published: February 2020

In order to study the motion of Expendable Bathythermograph (XBT) probe, the transient dropping process is numerically simulated by using Fluent software. In the paper, the dynamic mesh method, the 6DOF solver and the volume of fluid (VOF) model are used in Fluent. The trajectory, speed and rotating speed of the probe are investigated, and we also analyze the influence of the tail fin’s shape on the rotating speed. The numerical results show that the trajectory and key velocity of XBT probe are in accordance with the relevant research results. And we could get more detailed information than theory or experiment methods. The work can provide a research basis for the research on the underwater motion, stability and structure design of the XBT probe.
Critical Legal Orientalism: Rethinking the Comparative Discourse on Chinese Law
Authors: Coendet Thomas
Published: February 2020

Critical legal Orientalism is a tale of two empires, the United States and China. In the mid-nineteenth century, the United States established a special U.S. court for China, thus incorporating China as the largest district of their jurisdiction. This extraterritorial court operated for about a century and advanced an American legal imperialism in China that continues today. It is an empire founded on the notion of China as a place where law actually does not exist because neither its subjects nor its state lives up to the rule of law. Such Western assumptions about China and its legal tradition are called “legal Orientalism.” Comparative legal scholarship has introduced this concept and erected a critique of U.S. law and foreign policy around it. In the Chinese reception, this Western self-criticism has taken a political turn. Here, legal Orientalism feeds into an imperial narrative, which is no less ambitious than its American counterpart for it allows discrediting concerns about Chinese legal practice as an Orientalist misreading. Rule of law criticism is thereby silenced, and this extends the space for what has been recently called China’s “New Era.” The concept of legal Orientalism, as we know it today, is not ready to address such a political turn of legal Orientalism. It has no understanding of its own critical position beyond a Western self-criticism. Therefore, this Article develops the outlines of a critical legal Orientalism. It argues that legal Orientalism will be a critical project of comparative scholarship only if it reflects on its own position; and this includes reflecting on its political, ethical, and normative implications. A critical legal Orientalism thus marks a discursive position that neither serves to reinvent self-righteous empires nor to silence ideas of justice in their names.
Post-hurricane shifts in the morphology of island lizards
Authors: Rabe Allison M , Herrmann Nicholas C , Culbertson Katherine A , Donihue Colin M , Prado-Irwin Sofia R
Published: February 2020

Hurricanes are expected to increase in both frequency and intensity as a result of climate change, but the impacts of these disturbances on the evolutionary trajectories of the species they affect are not yet well understood. In this project, we investigated population-level changes in morphology in the lizard Anolis carolinensis after Hurricane Irma in 2017. We found that anole populations were morphologically distinct after the hurricane, exhibiting significantly longer forelimbs and hindlimbs compared with pre-hurricane measurements. These morphological changes were consistent across two replicate islands and between males and females. The observed morphological shifts were potentially driven by positive selection from Hurricane Irma on clinging capacity. In this opportunistic study, we documented post-hurricane changes in the morphology of island lizards and suggest the potential for increasingly frequent and intense hurricanes to play an important role in natural selection and anole evolution.
IFCC Working Group Recommendations for Correction of Bias Caused by Noncommutability of a Certified Reference Material Used in the Calibration Hierarchy of an End-User Measurement Procedure
Authors: Miller W Greg , Budd Jeffrey , Greenberg Neil , Weykamp Cas , Althaus Harald , Schimmel Heinz , Panteghini Mauro , Delatour Vincent , Ceriotti Ferruccio , Keller Thomas , Hawkins Douglas , Burns Chris , Rej Robert , Camara Johanna E , MacKenzie Finlay , van der Hagen Eline , Vesper Hubert
Published: February 2020

Establishing metrological traceability to an assigned value of a matrix-based certified reference material (CRM) that has been validated to be commutable among available end-user measurement procedures (MPs) is central to producing equivalent results for the measurand in clinical samples (CSs) irrespective of the clinical laboratory MPs used. When a CRM is not commutable with CSs, the bias due to noncommutability will be propagated to the CS results causing incorrect metrological traceability to the CRM and nonequivalent CS results among different MPs. In a commutability assessment, a conclusion that a CRM is commutable or noncommutable for use with a specific MP is made when the difference in bias between the CRM and CSs meets or does not meet a criterion for that specific MP when compared to other MPs. A conclusion regarding commutability or noncommutability requires that the magnitude of the difference in bias observed in the commutability assessment remains unchanged over time. This conclusion requires the CRM to be stable and no substantive changes in the MPs. These conditions should be periodically reverified. If an available CRM is determined to be noncommutable for a specific MP, that CRM can be used in the calibration hierarchy for that MP when an appropriately validated MP-specific correction for the noncommutability bias is included. We describe with examples how a MP-specific correction and its uncertainty can be developed and applied in a calibration hierarchy to achieve metrological traceability of results for CSs to the CRM’s assigned value.
Contrasting the suitability of shade coffee agriculture and native forest as overwinter habitat for Canada Warbler (Cardellina canadensis) in the Colombian Andes
Authors: González Ana M , Wilson Scott , Bayly Nicholas J , Hobson Keith A
Published: February 2020

In the Neotropics, coffee production occurs on a large scale in some of the planet’s most biodiverse regions: tropical mountains. Coffee production systems involving shade trees are considered to have a lower impact on biodiversity than alternative sun coffee. To date, the majority of evidence for the value of shade coffee plantations has not taken into account the relative quality of this habitat compared to the native forests they replaced. We determined the suitability of shade coffee and forest as winter habitat for Canada Warbler (Cardellina canadensis) by comparing variation in the likelihood of capturing individuals, seasonal changes in body condition, and estimates of annual survival between the 2 habitats. We also determined the effect of the strong 2015–2016 El Niño event on survival. Males were relatively more likely to be captured in forest than females and this likelihood increased during drier years. Body condition change over the winter and apparent annual survival were similar for individuals that used forest and coffee. However, condition and survival decreased in both habitats during the El Niño year. Apparent survival was also lower for individuals carrying a radiotag or geolocator. Our findings suggest that shade coffee with high canopy cover and height offers similar benefits to forest in terms of body condition and survival. Landscape conservation approaches, promoting diverse matrices of structurally complex shade coffee and forest might best ensure long-term survival in Neotropical migrants like Canada Warbler.
Interstage management of pulmonary blood flow after the Norwood procedure with right ventricle-to-pulmonary artery conduit
Authors: Yasukawa Takashi , Hoashi Takaya , Kitano Masataka , Shimada Masatoshi , Imai Kenta , Kurosaki Kenichi , Ichikawa Hajime
Published: February 2020

OBJECTIVES

Our goal was to assess the efficacy of managing pulmonary blood flow from the Norwood procedure with a right ventricle-to-pulmonary artery (RV–PA) conduit until stage 2 palliation (S2P).

METHODS

Among 48 consecutive patients undergoing the Norwood procedure between 2008 and 2018, 40 (83.3%) patients who survived to discharge were included in this study. The primary diagnosis was hypoplastic left heart syndrome in 28 (70%) patients and hypoplastic left heart syndrome variant in 12 (30%) patients. All patients received bilateral pulmonary artery banding. The median age and weight at the time of the Norwood procedure were 41 (25th–75th percentiles: 27–89) days and 3.2 (2.7–3.9) kg, respectively. In keeping with institutional strategy, S2P was undertaken when body weight exceeded 5.0 kg, and normal gross motor development was confirmed.

RESULTS

The RV–PA conduit was clipped in 28 (70%) patients during the perioperative period of the Norwood procedure, then partial unclipping was performed in 8 (20%) patients and full unclipping was performed in 20 (50%) patients. Before S2P, the median pulmonary-to-systemic blood flow ratio was 1.0 (0.7–1.3). The median age and weight at the time of S2P were 10.7 (9.0–12.9) months and 6.3 (5.5–7.1) kg, respectively. The survival rate 5 years after Norwood discharge was 85.3%. Pre-S2P pulmonary-to-systemic blood flow ratio was linearly correlated with greater interstage changes in systemic atrioventricular valve regurgitation (R2 = 0.223, P = 0.004).

CONCLUSIONS

Interstage management of pulmonary blood flow by RV–PA conduit clipping and gradual unclipping provided good interstage outcomes. The median pulmonary-to-systemic blood flow ratio could be controlled to 1.0 at pre-S2P catheter examination.
Moderate hypothermia with remote ischaemic preconditioning improves cerebral protection compared to deep hypothermia: a study using a surviving porcine model
Authors: Mustonen Caius , Honkanen Hannu-Pekka , Lehtonen Siri , Tuominen Hannu , Mäkelä Tuomas , Kaakinen Timo , Kiviluoma Kai , Anttila Vesa , Juvonen Tatu
Published: February 2020

OBJECTIVES

The optimal temperature management of hypothermic circulatory arrest is still controversial. Moderate hypothermia preserves cerebral autoregulation and shortens cardiopulmonary bypass (CPB) duration. However, moderate hypothermia alone has inferior organ protection to deep hypothermia, so adjuncts that increase the ischaemic tolerance are needed. Thus, we hypothesized that a combination of remote ischaemic preconditioning (RIPC) and moderate hypothermia would be superior to deep hypothermia alone.

METHODS

Sixteen pigs were randomized to either RIPC or control groups (8 + 8). The RIPC group underwent 4 cycles of transient hind limb ischaemia. The RIPC group underwent cooling with CPB to 24°C, and the control group underwent cooling with CPB to 18°C, followed by a 30-min arrest period and subsequent rewarming to 36°C. Measurements of cerebral metabolism were made from sagittal sinus blood samples and common carotid artery blood flow. The permissible periods of hypothermic circulatory arrest were calculated based on these measurements. Neurological recovery was evaluated daily during a 7-day follow-up, and the brain was harvested for histopathological analysis.

RESULTS

Six pigs in the RIPC group reached normal neurological function, but none in the control group reached normal neurological function (P = 0.007). The composite neurological score of all postoperative days was higher in the RIPC group than in the control group [55 (52–58) vs 45 (39–51), P = 0.026]. At 24°C, the estimated permissible periods of hypothermic circulatory arrest were 21 (17–25) min in the RIPC group and 11 (9–13) min in the control group (P = 0.007).

CONCLUSIONS

RIPC combined with moderate hypothermia provides superior cerebral protection.
Incidence and characteristics of hospitalization for proximal aortic surgery for acute syndromes and for aneurysms in the USA from 2005 to 2014
Authors: Mullan Clancy William , Mori Makoto , Bin Mahmood Syed Usman , Yousef Sameh , Mangi Abeel A , Elefteriades John A , Geirsson Arnar
Published: February 2020

OBJECTIVES

The effectiveness of proximal thoracic aortic aneurysm (TAA) surgery in preventing acute aortic syndromes, such as dissection and rupture, is unknown at the populational level. This study evaluated trends in acute aortic syndrome operation incidence relative to proximal aortic surgical volume in the USA.

METHODS

A retrospective analysis of the National Inpatient Sample in 2005–2014 was performed. Acute aortic syndrome and TAA were identified with International Classification of Diseases, 9th edition diagnosis codes. Proximal aortic surgery was defined as the diagnosis of acute aortic syndrome or TAA with an aortic procedure and either cardioplegia, cardiopulmonary bypass or other cardiac operation. Annual rates of acute aortic syndrome surgery and proximal thoracic aneurysm surgery were adjusted for US population. Trends were evaluated using linear regression.

RESULTS

We identified 38 442 operations for acute aortic diagnoses and 74 953 operations for TAAs. Case volume for acute aortic syndromes increased from 0.93 to 1.63 per 100 000 (P = 0.001), and aneurysm surgery increased from 1.75 to 3.19 per 100 000 (P < 0.001). Patient and hospital characteristics differed between acute aortic and aneurysm operations, with black patients being most notably underrepresented in the aneurysm population (4.9% vs 17.0%, P < 0.001).

CONCLUSIONS

Acute aortic syndrome operative volume increased from 2005 to 2014 despite increasing rates of proximal aortic aneurysm surgery. Patient characteristic discrepancies were observed between the 2 groups of hospitalizations, highlighting the need for continued efforts to minimize sociodemographic disparities.
The early life stages of the orange-spotted grouper,Epinephelus coioides, exhibit robustness to hypercapnia
Authors: Lonthair Joshua , Hwang Pung-Pung , Esbaugh Andrew J
Published: February 2020

Ocean acidification (OA) and other climate change-induced environmental alterations are resulting in unprecedented rates of environmental degradation. This environmental change is generally thought to be too fast for adaptation using evolutionary process dependent on natural selection, and thus, resilience may be related to the presence of existing tolerant genotypes and species. Estuaries undergo natural partial pressure carbon dioxide (pCO2) fluctuations, with levels regularly exceeding predicted end of the century values. In this study, we use the estuarine orange-spotted grouper (Epinephelus coioides) to explore the intrinsic resilience to elevated pCO2. Our sensitivity endpoints included: survival, heart rate, growth, and yolk consumption. Furthermore, we attempted to determine whether their acid–base regulatory machinery was plastic in response to elevated pCO2 by analysing the gene expression of key transporters and ionocyte density. Survival was not significantly altered by exposure to elevated pCO2. Interestingly, the heart rate was significantly elevated at both 1500 and 3100 μatm exposure. However, other metrics of energetic consumption, such as yolk consumption and growth, were not significantly altered. Furthermore, we found no changes in gene expression in vha, nhe3, and nbc, as well as ionocyte density at elevated pCO2. Overall, these results support the hypothesis that estuarine species are resilient to the impacts of OA.
Conforming and nonconforming virtual element methods for a Kirchhoff plate contact problem
Authors: Wang Fei , Zhao Jikun
Published: February 2020

We establish a general framework to study the conforming and nonconforming virtual element methods (VEMs) for solving a Kirchhoff plate contact problem with friction, which is a fourth-order elliptic variational inequality (VI) of the second kind. This VI contains a non-differentiable term due to the frictional contact. This theoretical framework applies to the existing virtual elements such as the conforming element, the $C^0$-continuous nonconforming element and the fully nonconforming Morley-type element. In the unified framework we derive a priori error estimates for these virtual elements and show that they achieve optimal convergence order for the lowest-order case. For demonstrating the performance of the VEMs we present some numerical results that confirm the theoretical prediction of the convergence order.
Rohlin Actions of Finite Groups on the Razak–Jacelon Algebra
Authors: Nawata Norio
Published: February 2020

Let $A$ be a simple separable nuclear C$^*$-algebra with a unique tracial state and no unbounded traces, and let $\alpha $ be a strongly outer action of a finite group $G$ on $A$. In this paper, we show that $\alpha \otimes \textrm{id}$ on $A\otimes \mathcal{W}$ has the Rohlin property where $\mathcal{W}$ is the Razak–Jacelon algebra. Combing this result with the recent classification results and our previous result, we see that such actions are unique up to conjugacy.
Noninvasive Determination of CMV Serostatus From Dried Buccal Swab Samples: Assay Development, Validation, and Application to 1.2 Million Samples
Authors: Behrens Geoffrey A , Brehm Michael , Groß Rita , Heider Jana , Sauter Jürgen , Baier Daniel M , Wehde Tatjana , Castriciano Santina , Schmidt Alexander H , Lange Vinzenz
Published: February 2020

Background

Buccal swab sampling constitutes an attractive noninvasive alternative to blood drawings for antibody serostatus assays. Here we describe a method to determine the cytomegalovirus immunoglobulin G (CMV IgG) serostatus from dried buccal swab samples.

Methods

Upon solubilization, CMV IgG is determined by an ELISA assay specifically adapted to cope with low IgG concentrations. The derived CMV titer is normalized against the total protein concentration to adjust for incorrectly or less efficiently sampled buccal swabs. Assay parameters were optimized on a set of 713 samples.

Results

Validation with 1784 samples revealed distinct results for > 80% of samples with 98.6% specificity and 99.1% sensitivity. Based on the analysis of 1.2 million samples we derived age- and sex-stratified CMV prevalence statistics for Germany, Poland, United Kingdom, and Chile. To confirm accuracy of the assay in routine operation, the CMV status of 6518 donors was reassessed by independent laboratories based on conventional blood samples revealing 96.9% specificity and 97.4% sensitivity.

Conclusions

The assay accurately delivers the CMV IgG serostatus from dried buccal swab samples for > 80% of the participants. Thereby it provides a noninvasive alternative to plasma-based CMV monitoring for nondiagnostic purposes such as hematopoietic stem cell transplantation donor screening or population studies.
Mathematical analysis for Brownian motion of nonlinear thermal bioconvective stagnation point flow in a nanofluid using DTM and RKF method
Authors: Mondal Surya Kanta , Pal Dulal
Published: February 2020

In the present paper, bioconvective stagnation point flow of nanofluid containing gyrotactic microorganisms over a nonlinearly stretching sheet embedded in a porous medium is considered. The scaling group transformation method is introduced to obtain the similarity transformation to convert the governing partial differential equations to a set of ordinary differential equations. The reduced governing nonlinear differential equations are then solved numerically with Runge–Kutta–Fehlberg method. Differential transform method is employed to justify the results obtained by the numerical method. It is found that both the results matched nicely. It is noticed that the density of motile microorganism distribution grows high with an increase in the values of the bioconvection Peclet number. Further, the rate of heat transfer and the rate of mass transfer increase rapidly with an increment in the thermophoresis parameter, heat source parameter, chemical reaction parameter, and Brownian motion parameter, respectively. This work is relevant to engineering and biotechnological applications, such as in the design of bioconjugates and mass transfer enhancement of microfluidics.
Linking extended and plateau emissions of short gamma-ray bursts
Authors: Matsumoto Tatsuya , Kimura Shigeo S , Murase Kohta , Mészáros Peter
Published: February 2020

Some short gamma-ray bursts (SGRBs) show a longer lasting emission phase, called extended emission (EE) lasting ${\sim}10^{2\!-\!3}\, \rm s$, as well as a plateau emission (PE) lasting ${\sim}10^{4\!-\!5}\, \rm s$. Although a long-lasting activity of the central engines is a promising explanation for powering both emissions, their physical origin and their emission mechanisms are still uncertain. In this work, we study the properties of the EEs and their connection with the PEs. First, we constrain the minimal Lorentz factor Γ of the outflows powering EEs, using compactness arguments and find that the outflows should be relativistic, Γ ≳ 10. We propose a consistent scenario for the PEs, where the outflow eventually catches up with the jet responsible for the prompt emission, injecting energy into the forward shock formed by the prior jet, which naturally results in a PE. We also derive the radiation efficiency of EEs and the Lorentz factor of the outflow within our scenario for 10 well-observed SGRBs accompanied by both EE and PE. The efficiency has an average value of ${\sim}3\, {{\ \rm per\ cent}}$ but shows a broad distribution ranging from ∼0.01 to ${\sim}100{{\ \rm per\ cent}}$. The Lorentz factor is ∼20–30, consistent with the compactness arguments. These results suggest that EEs are produced by a slower outflow via more inefficient emission than the faster outflow that causes the prompt emission with a high radiation efficiency.
J-PAS: forecasts on dark energy and modified gravity theories
Authors: Aparicio Resco Miguel , Maroto Antonio L , Alcaniz Jailson S , Abramo L Raul , Hernández-Monteagudo C , Benítez N , Carneiro S , Cenarro A J , Cristóbal-Hornillos D , Dupke R A , Ederoclite A , López-Sanjuan C , Marín-Franch A , Moles M , Oliveira C M , Sodré Jr L , Taylor K , Varela J , Vázquez Ramió H
Published: February 2020

The next generation of galaxy surveys will allow us to test one of the most fundamental assumptions of the standard cosmology, i.e. that gravity is governed by the general theory of relativity (GR). In this paper, we investigate the ability of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) to constrain GR and its extensions. Based on the J-PAS information on clustering and gravitational lensing, we perform a Fisher matrix forecast on the effective Newton constant, μ, and the gravitational slip parameter, η, whose deviations from unity would indicate a breakdown of GR. Similar analysis is also performed for the DESI and Euclid surveys and compared to J-PAS with two configurations providing different areas, namely an initial expectation with 4000 deg2 and the future best case scenario with 8500 deg2. We show that J-PAS will be able to measure the parameters μ and η at a sensitivity of $2\!-\!7{{\ \rm per\ cent}}$, and will provide the best constraints in the interval z = 0.3–0.6, thanks to the large number of ELGs detectable in that redshift range. We also discuss the constraining power of J-PAS for dark energy models with a time-dependent equation-of-state parameter of the type w(a) = w0 + wa(1 − a), obtaining Δw0 = 0.058 and Δwa = 0.24 for the absolute errors of the dark energy parameters.
The effects of disc self-gravity and radiative cooling on the formation of gaps and spirals by young planets
Authors: Zhang Shangjia , Zhu Zhaohuan
Published: February 2020

We have carried out 2D hydrodynamical simulations to study the effects of disc self-gravity and radiative cooling on the formation of gaps and spirals. (1) With disc self-gravity included, we find stronger, more tightly wound spirals and deeper gaps in more massive discs. The deeper gaps are due to the larger Angular Momentum Flux (AMF) of the waves excited in more massive discs, as expected from the linear theory. The position of the secondary gap does not change, provided that the disc is not extremely massive (Q ≳ 2). (2) With radiative cooling included, the excited spirals become monotonically more open (less tightly wound) as the disc’s cooling time-scale increases. On the other hand, the amplitude and strength of the spirals decrease when the cooling time increases from a small value to ∼1/Ω, but then the amplitude starts to increase again when the cooling time continues to increase. This indicates that radiative dissipation becomes important for waves with Tcool ∼ 1. Consequently, the induced primary gap is narrower and the secondary gap becomes significantly shallower when the cooling time becomes ∼1/Ω. When the secondary gap is present, the position of it moves to the inner disc from the fast cooling cases to the slow cooling cases. The dependence of gap properties on the cooling time-scale (e.g. in AS 209) provides a new way to constrain the disc optical depth and thus disc surface density.
SALT revisits DY Cen: a rapidly evolving strontium-rich single helium star
Authors: Jeffery C Simon , Rao N Kameswara , Lambert David L
Published: February 2020

The hydrogen-deficient star DY Cen has been reported as an R CrB-type variable, an extreme helium star (with some hydrogen), and as a single-lined spectroscopic binary. It has been associated with a dramatic change in visual brightness and colour corresponding to a change in effective temperature ( Teff) of some 20 000 K in the last century. To characterize the binary orbit and  Teff changes more precisely, new high-resolution spectroscopy has been obtained with SALT. The previous orbital period is not confirmed; previous measurements may have been confused by the presence of pulsations. Including data from earlier epochs (1987, 2002, and 2010), self-consistent spectral analyses from all four epochs demonstrate an increase in  Teff from 18 800 to 24 400 K between 1987 and 2015. Line profiles demonstrate that the surface rotation has increased by a factor of 2 over the same interval. This is commensurate with the change in  Teff and an overall contraction. Rotation will exceed critical if contraction continues. The 1987 spectrum shows evidence of a very high abundance of the s-process element strontium. The very rapid evolution, non-negligible surface hydrogen and high surface strontium point to a history involving a very late thermal pulse. Observations over the next 30 yr should look for a decreasing pulsation period, reactivation of R CrB-type activity as the star seeks to shed angular momentum and increasing illumination by emission lines from nebular material ejected in the past.
The role of galaxy mass on AGN emission: a view from the VANDELS survey
Authors: Magliocchetti M , Pentericci L , Cirasuolo M , Zamorani G , Amorin R , Bongiorno A , Cimatti A , Fontana A , Garilli B , Gargiulo A , Hathi N P , McLeod D J , McLure R J , Brusa M , Saxena A , Talia M
Published: February 2020

We present a comparative analysis of the properties of active galactic nuclei (AGNs) emitting at radio and X-ray wavelengths. The study is performed on 907 X-ray AGNs and 100 radio AGNs selected on the CDFS and UDS fields and makes use of new and ancillary data available to the VANDELS collaboration. Our results indicate that the mass of the host galaxy is a fundamental quantity that determines the level of AGN activity at the various wavelengths. Indeed, large stellar masses are found to be connected with AGN radio emission, as virtually all radio-active AGNs reside within galaxies of M* > 1010 M⊙. Large stellar masses also seem to favour AGN activity in the X-ray, even though X-ray AGNs present a mass distribution that is more spread out and with a non-negligible tail at M* ≲ 109 M⊙. Stellar mass alone is also observed to play a fundamental role in simultaneous radio and X-ray emission: the percentage of AGNs active at both wavelengths increases from around 1 per cent of all X-ray AGNs residing within hosts of M* < 1011 M⊙ to ∼13 per cent in more massive galaxies. In the case of radio-selected AGNs, such a percentage moves from ∼15 per cent to ∼45 per cent (but up to ∼80 per cent in the deepest fields). Neither cosmic epoch, nor radio luminosity, X-ray luminosity, Eddington ratio or star formation rate of the hosts are found to be connected to an enhanced probability for joint radio + X-ray emission of AGN origin. Furthermore, only a loose relation is observed between X-ray and radio luminosity in those AGNs that are simultaneously active at both frequencies.
Updated fundamental constant constraints from Planck 2018 data and possible relations to the Hubble tension
Authors: Hart Luke , Chluba Jens
Published: February 2020

We present updated constraints on the variation of the fine structure constant, αEM, and effective electron rest mass, me, during the cosmological recombination era. These two fundamental constants directly affect the ionization history at redshift z ≃ 1100 and, thus, modify the temperature and polarization anisotropies of the cosmic microwave background (CMB) measured precisely with Planck . The constraints on αEM tighten slightly due to improved Planck 2018 polarization data but otherwise remain similar to previous CMB analysis. However, a comparison with the 2015 constraints reveals a mildly discordant behaviour for me, which from CMB data alone is found below its local value. Adding baryon acoustic oscillation data brings me back to the fiducial value, $m_{\rm e}=(1.0078\pm 0.0067)\, m_{\rm e,0}$, and also drives the Hubble parameter to H0 = 69.1 ± 1.2(in units of ${\rm km \, s^{-1} \, Mpc^{-1} }$). Further adding supernova data yields $m_{\rm e}=(1.0190\pm 0.0055)\, m_{\rm e,0}$ with H0 = 71.24 ± 0.96. We perform several comparative analyses using the latest cosmological recombination calculations to further understand the various effects. Our results indicate that a single-parameter extension allowing a slightly increased value of me (≃3.5σ above me, 0) could play a role in the Hubble tension.
Using Drumbeats to Theorize Meter in Quintuple and Septuple Grooves
Authors: Hanenberg Scott J
Published: February 2020

This article explores common approaches taken by drummers when playing music with a quintuple or septuple groove. Based on original analysis from a corpus of 350 songs released during the half-century between 1967 and 2017, I show that these grooves fall into three categories: undifferentiated, in which the drum/s and/or cymbal/s that mark each attack do not change in the course of the groove; backbeat variants, based on the alternation of kick and snare attacks, as in the common-time backbeat; and polymetric grooves comprising two distinct metric cues, often pitting the drums against the rest of the band.
A memory switch for plant synthetic biology based on the phage ϕC31 integration system
Authors: Bernabé-Orts Joan Miquel , Quijano-Rubio Alfredo , Vazquez-Vilar Marta , Mancheño-Bonillo Javier , Moles-Casas Victor , Selma Sara , Gianoglio Silvia , Granell Antonio , Orzaez Diego
Published: February 2020

Synthetic biology has advanced from the setup of basic genetic devices to the design of increasingly complex gene circuits to provide organisms with new functions. While many bacterial, fungal and mammalian unicellular chassis have been extensively engineered, this progress has been delayed in plants due to the lack of reliable DNA parts and devices that enable precise control over these new synthetic functions. In particular, memory switches based on DNA site-specific recombination have been the tool of choice to build long-term and stable synthetic memory in other organisms, because they enable a shift between two alternative states registering the information at the DNA level. Here we report a memory switch for whole plants based on the bacteriophage ϕC31 site-specific integrase. The switch was built as a modular device made of standard DNA parts, designed to control the transcriptional state (on or off) of two genes of interest by alternative inversion of a central DNA regulatory element. The state of the switch can be externally operated by action of the ϕC31 integrase (Int), and its recombination directionality factor (RDF). The kinetics, memory, and reversibility of the switch were extensively characterized in Nicotiana benthamiana plants.
Section 7 of the BC Power of Attorney Act: what does it say and why does it say it?
Authors: Nitikman Joel
Published: February 2020

For a very long time, the common law has provided that an agent does not have the authority to sign a sealed document on behalf of the agent’s principal unless the principal granted authority to the agent to do so under seal. It also provides that an agent who enters into a sealed contract becomes a party personally to the contract and the principal is not a party to the so-called sealed contract rule. This article suggests that both common-law rules have been overtaken by certain legislative provisions in force in British Columbia (BC). In particular, the second rule may not have been in force in the UK since the coming-into-force in 1881 of the Conveyancing and Law of Property Act, the operative part of which has been enacted in BC, various states of Australia, New Zealand and various other Commonwealth countries. The article goes on to suggest that the one UK decision relied on by a leading textbook in support of the continuing validity of the sealed contract rule is not a valid authority on that point.
A systematic review on the mechanisms of malignant transformation of oral submucous fibrosis
Authors: Phulari Rashmi G.S. , Dave Esha J.
Published: February 2020

Oral submucous fibrosis (OSMF), the most commonly encountered potentially premalignant oral epithelial lesion, is a chronic disorder associated with areca nut chewing. It has a relatively high potential for malignant transformation resulting into oral squamous cell carcinoma (OSCC), the most common oral malignancy with high mortality rate. Paymaster first described the malignant potential of OSMF in 1956, the rate of which had been estimated to be 7–13%. The pathogenesis of OSMF in itself is quite varied, and hence, its transformation to malignancy is also open to many varied mechanisms. The early diagnosis and sequentially, early treatment of OSMF is desirable so that the progression towards malignancy can be controlled. There are various theories that have been put forward explaining the probable pathway of malignant transformation of OSMF such as hypoxia, areca nut as a carcinogen or epithelial–mesenchymal transitions. Many recent molecular advances have also highlighted few biomarkers and genes that play a pivotal role in transformation of OSMF to OSCC. The purpose of this systematic review is to discuss all the possible mechanisms of malignant transformation of OSMF. Further research is still needed to establish the exact mechanism responsible for transformation of OSMF to OSCC and to reduce the mortality by newer interventions.
D1- but not D2-like dopamine receptor antagonist in the CA1 region of the hippocampus reduced stress-induced reinstatement in extinguished morphine-conditioning place preference in the food-deprived rats
Authors: Nazari-Serenjeh Farzaneh , Jamali Shole , Rezaee Laleh , Zarrabian Shahram , Haghparast Abbas
Published: February 2020

Relapsing to drugs of abuse is a challenging problem in treatment of addiction and stress is believed to be a major risk factor in relapse to drugs. The hippocampus region and dopamine signaling play a critical role in reward-related behaviors. The purpose of this study is to identify the involvement of D1- and D2-like receptors in the CA1 region of hippocampus in the reinstatement induced by a combination of food deprivation stress and a sub-threshold dose of morphine in extinguished morphine-conditioning place preference in rats. Adult male rats treated with one specific doses of SCH-23390 or sulpiride (0.5, 2 and 4 µg/0.5 µl vehicle/side) as D1- and D2-like receptors antagonists into the CA1 in separate groups, following the conditioning and extinction phase of morphine-conditioning place preference, before initiating the food deprivation stress on the last day of extinction. Then, the food deprived animals examined for reinstatement by injection of the sub-threshold dose of morphine (0.5 mg/kg, s.c.) on reinstatement day. Conditioning place preference scores and locomotor activities were recorded during test. Our results showed that combination of food deprivation stress and a sub-threshold dose of morphine induced the reinstatement of morphine-conditioning place preference. The induced reinstatement was decreased by two higher doses of SCH-23390 (2 and 4 µg/0.5 µl vehicle/side). However, the sulpiride (0.5, 2 and 4 µg/0.5 µl vehicle/side) could not reduce the reinstatement. Results showed that the role of D1-like receptor in the CA1 region was more prominent than D2-like receptor in reinstatement induced by food deprivation stress and re-exposure to morphine. Therefore the D1-like receptor in the CA1 might be a potential therapeutic target for treatment of opiate addiction.
Lipoprotein(a) and long-term recurrent infarction after an episode of ST-segment elevation acute myocardial infarction
Authors: Miñana Gema , Gil-Cayuela Carolina , Bodi Vicent , de la Espriella Rafael , Valero Ernesto , Mollar Anna , Marco Maria , García-Ballester Teresa , Zorio Begoña , Fernández-Cisnal Agustín , Chorro Francisco J. , Sanchis Juan , Núñez Julio
Published: February 2020

Background

In established ischemic heart disease, the relationship between lipoprotein(a) and new cardiovascular events showed contradictory results. Our aim was to assess the relationship between lipoprotein(a) and very long-term recurrent myocardial infarction (MI) after an index episode of ST-segment elevation acute myocardial infarction (STEMI).

Methods

We included 435 consecutive STEMI patients discharged from October 2000 to June 2003 in a single teaching center. The relationship between lipoprotein(a) at discharge and recurrent MI was evaluated through negative binomial regression and Cox regression analysis.

Results

The mean age was 65 years (55–74 years), 25.5% were women, 34.7% were diabetic, and 66% had a MI of anterior location. Fibrinolysis, rescue, or primary angioplasty was performed in 215 (49.4%), 19 (4.4%), and 18 (4.1%) patients, respectively. The median lipoprotein(a) was 30.4 mg/dL (12–59.4 mg/dL). After a median follow-up of 9.6 years (4.1–15 years), 180 (41.4%) deaths and 187 MI in 133 (30.6%) patients were recorded. After a multivariate adjustment, the risk gradient of lipoprotein(a) showed a neutral effect along most of the continuum and only extreme higher values identified those at higher risk of recurrent MI (P = 0.020). Those with lipoprotein(a) values >95th percentile (≥135 mg/dL) showed a higher risk of recurrent MI (incidence rate ratio, 2.34; 95% confidence interval, 1.37–4.02; P = 0.002). Lipoprotein(a) was not related to the risk of mortality (P = 0.245).

Conclusions

After an episode of STEMI, only extreme high values of lipoprotein(a) were associated with an increased risk of long-term recurrent MI.
Evaluation of the synergistic effect of cinnamon extract and honey against multidrug-resistant isolates of Pseudomonas aeruginosa recovered from burn unit
Authors: Karami Pezhman , Khaledi Azad , Dastan Dara , Yaghoobi Mojtaba Hedayat , Karami Manoochehr , Mashoof Rasool Yousefi , Alikhani Mohammad Yousef
Published: February 2020

Background:

Due to rapid increase of drug resistance and failure of the current antibiotics to treat infections caused by Pseudomonas aeruginosa multidrug-resistant (MDR) isolates, introduction of the new therapeutic combinations is needed. This study aimed to evaluate the synergistic effects of cinnamon extracts and honey against MDR isolates of P. aeruginosa recovered from burn unit.

Methods:

The minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) of each antibiotic (Gentamicin and Ciprofloxacin) alone or in combination with the aqueous and alcoholic extracts of cinnamon and honey was determined by broth microdilution method for clinical and environmental isolates of P. aeruginosa based on the Clinical & Laboratory Standards Institute (CLSI) guidelines. The synergistic effect of combinations was evaluated using a checkerboard test. Data analyzed using chi-square and Fisher's exact tests (SPSS software). P-value of less than 0.05 was considered to indicate statistically significant differences.

Results:

The mean MICs for Cinnamomum zeylanicum alcoholic extract-honey(CZAH), C. zeylanicum watery extract--honey(CZWH), Ciprofloxacin--C. zeylanicum watery extract (CPCZW), Gentamicin--C. zeylanicum watery extract (GMCZW), Ciprofloxacin—C. zeylanicum alcoholic extract (CPCZA), Gentamicin--C. zeylanicum alcoholic extract (GMCZA), Ciprofloxacin—honey (CPH), Gentamicin--honey (GMH) against MDR strains were as 6.80, 15.63, 18.62, 5.84, 10.70, 3.84 and 36.88 μg/ml, respectively. The mean MBC for CZAH, CZWH, CPCZW, GMCZW, CPCZA, GMCZA, CPH and GMH against MDR strains were as 13.17, 30.25, 29.63, 31.52, 11.32, 21.28, 60.11 and 70.03 μg/ml, respectively. According to the FICi results, 14.1, 1.3, 3.8, 19.2, 32.1, 29.5, 9 and 9% of isolates had the synergism for CZAH, CZWH, CPCZW, GMCZW, CPCAA, GMCZA, CPH and GMH combinations, respectively.

Conclusion:

This study showed a proper synergistic effect of aqueous and alcoholic extracts of cinnamon and honey in combination with Ciprofloxacin and Gentamicin against MDR isolates of P. aeruginosa.
Acne vulgaris and antimicrobial resistance: a review
Authors: Varghese Aneena
Published: February 2020

Background:

Acne is a chronic inflammatory disease of skin follicle on the face, which affects almost 85% youngsters and adolescents. The most common causative agent is Propionibacterium species. The evaluation of antimicrobial activity of turmeric and neem, two Indian herbs in facial cosmetics may provide a better treatment option for acne.

Objective:

The review was to evaluate the microbiological characterization of Propionibacteria isolates from acne vulgaris cases and to identify the antimicrobial action against common antibiotics in use and different herbal extracts.

Method:

A regimented search in the online databases such as PubMed, EMBASE, Google scholar, scopus and so on was done to identify relevant studies according to search strategies. Other search engines were also used, but could not extract relevant articles or studies form those electronic data bases. From the electronic search, 125 articles were identified, after title and abstract review, 96 articles were retained as eligible. A full-text evaluation resulted in 23 studies to be included for review.

Conclusion:

The results suggests that Propionibacterium acnes is the main causative agent for pustular acne vulgaris and metronidazole was expectedly sensitive to P. acnes, whereas erythromycin and Clindamycin is emerging resistance.
Navigating a Minefield
Authors: SmithBattle Lee , Phengnum Wisitsri , Punsuwun Sasinun
Published: February 2020

Teen mothers have lower rates of breastfeeding duration and exclusivity than older mothers. A growing body of qualitative research on teen mothers' experience helps to explain these disparities. Following a systematic search to identify relevant research, we synthesized the findings from 22 primary studies to conclude that teen mothers navigate a minefield that undermines their intention to breastfeed and their breastfeeding confidence and skill. This metaphorical minefield reflects competing norms for infant feeding and good mothering, as evident in mixed support from teens' social networks; fragmented and stigmatizing healthcare; and spaces that are inhospitable to teen mothers and breastfeeding mothers in general.

In recognition of this minefield, we urge clinicians to: respect teen mothers' infant feeding decisions; develop collaborative relationships based on the principles of patient-centered and strength-based care; challenge stigmatizing healthcare practices; welcome teen mothers and their significant others to clinical settings; and press health systems to fully implement probreastfeeding policies. We also recommend further study to extend our knowledge about teen mothers' breastfeeding experiences.