bluuebunny/crossref_metadata_2025 huggingface dataset:
Over‐expression of TFB2M facilitates cell growth and metastasis via activating ROS‐Akt‐NF‐κB signalling in hepatocellular carcinoma
Authors: Geng Xilin , Geng Zhimin , Li Hui , Zhang Yu , Li Jibin , Chang Hulin
Published: March 2020

Background & Aims

Human TFB2M (mitochondrial transcription factor B2) is a key regulator of mitochondria transcription. Our bioinformatic analysis based on the cancer genome atlas (TCGA) data revealed an aberrant over‐expression of TFB2M in hepatocellular carcinoma (HCC). However, the functional roles of TFB2M in tumourigenesis remains unexplored, including HCC.

Methods

The expression and clinical significance of TFB2M were evaluated by qRT‐PCR and western blot analysis. The biological effects and underlying mechanisms of TFB2M in HCC were determined by cell proliferation, colony formation, cell cycle, apoptosis, migration and invasion assays.

Results

TFB2M was commonly up‐regulated in HCC mainly because of the down‐regulation of miR101‐3p, which significantly correlated with poor survival of HCC patients. Functional experiments revealed that TFB2M significantly promoted HCC cell proliferation, migration and invasion, while inhibited apoptosis in vitro and promoted xenograft tumourigenesis and lung metastasis in nude mice models in vivo. Mechanistically, increased production of reactive oxygen species (ROS) and subsequently activated Akt/NF‐κB signalling was found to be involved in the promotion of growth and metastasis by TFB2M in HCC cells.

Conclusions

These findings suggest that TFB2M plays a pivotal oncogenic role in HCC cells through activating ROS‐Akt‐NF‐κB signalling pathway.
Can income inequality promote democratization?
Authors: Policardo Laura , Sanchez Carrera Edgar J.
Published: March 2020

The aim of this paper is to study the effect of income inequality on the probability of democratization, in a panel of 51 transition countries during the period 1960–2008. Using a conditional fixed‐effect logit estimation, we find robust results suggesting that income inequality (measured by the Gini index of household’s income inequality) has an inverse—U‐shaped relation with the probability of transition from autarchy to democracy. We show that there is a turning point at a level of household’s income inequality equal to a Gini index of 40. When income inequality is below 40, then probability of transition is positively related to inequality, but when inequality is higher, a subsequent increase in inequality decreases the probability of democratization. This is consistent with Acemoglu and Robinson’s theory that shows how transitions are likeliest at moderate levels of inequality, while autocracy is likelier at the lowest and highest levels of inequality.
Risk factors and outcomes of culture‐proven acute Coccidioides spp. infection in San Diego, California, United States
Authors: Jenks Jeffrey D. , Reed Sharon L. , Hoenigl Martin
Published: March 2020

Background

Coccidioides spp. are dimorphic fungi endemic to parts of the United States, Mexico, Central and South America. Infection can cause a range of disease from self‐limited acute pneumonia to severe disseminated disease.

Methods

We performed a retrospective chart review of medical records of cases of culture‐proven acute coccidioidomycosis at the University of California San Diego between 1 April 2015 and 31 December 2019 and described the demographics, risk factors and outcomes of these cases.

Results

Over the study period, fifteen evaluable cases of culture‐proven acute coccidioidomycosis were identified. Of these, 87% (13/15) had traditional risk factors for coccidioidomycosis infection while two lacked known risk factors, including one patient with cirrhosis and one with chronic hepatitis C infection. Seven of fifteen (47%) had primary coccidioidomycosis of the lungs without dissemination and 7/15 (47%) disseminated disease. Of those with disseminated disease, 6/7 (86%) had either high‐risk ethnicity or blood type as their only risk factor. At 90 days, 11/15 (73%) were alive, 3/15 (20%) deceased and 1/15 (7%) lost to follow‐up. Of those not alive at 90 days, 1/3 (33%) had disseminated disease and 2/3 (67%) primary coccidioidomycosis, both on immunosuppressive therapy.

Discussion

Coccidioides spp. infection occurs in a variety of hosts with varying underlying risk factors, with the majority in our cohort overall and 86% with disseminated disease lacking traditional risk factors for invasive fungal infection other than ethnicity and/or blood phenotype. Clinicians should be aware of these non‐traditional risk factors in patients with coccidioidomycosis infection.
OsTMF attenuates cold tolerance by affecting cell wall properties in rice
Authors: Xu Yan , Hu Dan , Hou Xin , Shen Jianqiang , Liu Juhong , Cen Xiang , Fu Jie , Li Xianghua , Hu Honghong , Xiong Lizhong
Published: March 2020

Plant cell wall composition and structure can be modified as plants adapt to environmental stresses; however, the underlying regulatory mechanisms remain elusive.

Here, we report that OsTMF, a homologue of the human TATA modulatory factor (TMF) in rice (Oryza sativa) and highly conserved in plants, negatively regulates cold tolerance through modification of cell wall properties.

Cold stress increased the expression of OsTMF and accumulation of OsTMF in the nucleus, where OsTMF acts as a transcription activator and modulates the expression of genes involved in pectin degradation (OsBURP16), cellulose biosynthesis (OsCesA4 and OsCesA9), and cell wall structural maintenance (genes encoding proline‐rich proteins and peroxidases). OsTMF directly activated the expression of OsBURP16, OsCesA4, and OsCesA9 through binding to the TATA cis‐elements in their promoters. Under cold stress conditions, OsTMF negatively regulated pectin content and peroxidase activity and positively regulated cellulose content, causing corresponding alterations to cell wall properties, all of which collectively contribute to the negative effect of OsTMF on cold tolerance.

Our findings unravel a previously unreported molecular mechanism of a conserved plant TMF protein in the regulation of cell wall changes under cold stress.
Highly efficient homology‐directed repair using CRISPR/Cpf1‐geminiviral replicon in tomato
Authors: Vu Tien Van , Sivankalyani Velu , Kim Eun‐Jung , Doan Duong Thi Hai , Tran Mil Thi , Kim Jihae , Sung Yeon Woo , Park Minwoo , Kang Yang Jae , Kim Jae‐Yean
Published: March 2020

Genome editing via the homology‐directed repair (HDR) pathway in somatic plant cells is very inefficient compared with error‐prone repair by nonhomologous end joining (NHEJ). Here, we increased HDR‐based genome editing efficiency approximately threefold compared with a Cas9‐based single‐replicon system via the use of de novo multi‐replicon systems equipped with CRISPR/LbCpf1 in tomato and obtained replicon‐free but stable HDR alleles. The efficiency of CRISPR/LbCpf1‐based HDR was significantly modulated by physical culture conditions such as temperature and light. Ten days of incubation at 31 °C under a light/dark cycle after Agrobacterium‐mediated transformation resulted in the best performance among the tested conditions. Furthermore, we developed our single‐replicon system into a multi‐replicon system that effectively increased HDR efficiency. Although this approach is still challenging, we showed the feasibility of HDR‐based genome editing of a salt‐tolerant SlHKT1;2 allele without genomic integration of antibiotic markers or any phenotypic selection. Self‐pollinated offspring plants carrying the HKT1;2 HDR allele showed stable inheritance and germination tolerance in the presence of 100 mm NaCl. Our work may pave the way for transgene‐free editing of alleles of interest in asexually and sexually reproducing plants.
Cryptochromes in the field: how blue light influences crop development
Authors: Fantini Elio , Facella Paolo
Published: March 2020

Light is a pivotal environmental element capable of influencing multiple physiological processes across the entire plant life cycle. Over the course of their evolution, plants have developed several families of photoreceptors such as phytochromes, phototropins, ultraviolet (UV) resistance locus 8 and cryptochromes (crys), in order to sense light stimuli and respond to their changes. Numerous genetic studies have demonstrated that functional alterations to these photoreceptors cause a change in important agronomical traits. In particular, crys, which absorb UVA/blue light, can influence seed germination, flowering induction, plant architecture, fruit metabolic content and resistance to biotic and abiotic stresses. In the years to come, the rising temperatures and alterations to precipitation patterns generated by climate change will present a dramatic challenge for our agricultural system, with its few varieties characterized by a narrow genetic pool derived from artificial selection. Here, we review the main roles of crys in determining important agronomic traits in crops, we discuss the opportunities of using these photoreceptors as genetic targets for tuning plant physiological responses to environmental change, and the molecular strategies used so far to manipulate this family of photoreceptors.
Robust and Adaptive Anticoagulant Control
Authors: Avery Peter , Clairon Quentin , Henderson Robin , James Taylor C. , Wilson Emma
Published: March 2020

We consider a control theory approach to adaptive dose allocation of anticoagulants, based on an analysis of records of 152 patients on long-term warfarin treatment. We consider a selection of statistical models for the relationship between the dose of drug and subsequent blood clotting speed, measured through the international normalized ratio. Our main focus is on subsequent use of the model in guiding the choice of the next dose adaptively as patient-specific information accrues. We compare a naive long-term approach with a proportional-integral-plus method, with parameters estimated by either linear quadratic optimization or by stochastic resource allocation. We demonstrate advantages of the control approaches in comparison with a naive approach in simulations and through calculation of robust stability margins for the observed data.
Vascular injury during laparoscopic gynaecological surgery: a methodological approach for prevention and management
Authors: Brierley Gemma , Arshad Ilyas , Shakir Fevzi , Visvathanan Dilip , Arambage Kirana
Published: March 2020

Key content

Major vascular injuries occur in up to one in 200 laparoscopies, most commonly during Veress needle insertion or primary trocar entry; laparoscopic surgeons should rehearse actions to be taken in case of injury.

Vascular injury during laparoscopy is associated with significant morbidity and up to 23% mortality.

Risk factors include previous surgery, intra‐abdominal pathology, low/high body mass index and complex surgeries.

Techniques to manage vascular injury include aggressive fluid resuscitation, hyperbaric pressure, blood transfusion, manual pressure, considering conversion to an open midline laparotomy and the involvement of a vascular or general surgeon.

Standardised assessment and management protocols should be rehearsed and available in all units.

Learning objectives

To be aware of the incidence of laparoscopic vascular injury and the potential complications that can occur.

To recognise key risk factors for vascular injury and ways to prevent injury occurring.

To rehearse drills on systematic emergency management of laparoscopic bleeding to standardise care; this is ideally suited to the realms of multidisciplinary simulation scenario‐based training, to improve a team’s response to a vascular injury.

Ethical issues

Are women who are at increased risk of vascular injuries appropriately counselled regarding complications and consequences, and are they given the options for alternative management?
Effect of expiratory phase for radiographic detection of left heart enlargement in dogs with mitral regurgitation
Authors: Chhoey Saran , Lee Sang‐Kwon , Je Hyejin , Jung Jin‐Woo , Jang Youjung , Choi Jihye
Published: March 2020

Radiography is a standard diagnostic test for characterizing left heart enlargement in dogs however limited information is available on the effects of respiratory phases. This prospective and retrospective method comparison study investigated the respiratory effect on the size and shape of the left heart in dogs to determine the usefulness of expiratory radiographs to detect enlargements in the left atrium (LA) and left ventricle (LV). Thoracic radiographs taken at full inspiration and expiration were evaluated in 20 normal beagles and 100 dogs diagnosed with mitral regurgitation (MR). Vertebral heart score (VHS), vertebral left atrial size, elevation of the carina, and dorsal bulging of LA on lateral view and lateral bulging of the left auricular appendage and LV on ventrodorsal view were assessed. In normal dogs, there were no significant differences in the evaluative factors between inspiration and expiration. In dogs with MR, VHS did not change according to respiration. However, bulging of the LA, left auricular appendage, and LV had sharp margin during expiration compared with inspiration. The expiratory radiographic finding of LA bulging had a higher correlation with the LA to aorta ratio compared with LA bulging in the inspiratory radiography. Using a LA to aorta echocardiographic ratio greater than 1.5 as the gold standard, the radiographic sensitivity for LA enlargement was higher during expiration than inspiration. These findings of our study indicated that expiratory radiography can be helpful to support the detection of left heart enlargement, although it can overestimate LA enlargement in dogs with MR.
A Business Analysis Perspective for Engineering Education in Egypt
Authors: Elsafty Ashraf , Sayad Hanaa El , Shaaban Ibrahim
Published: March 2020

This work examines engineering education in Egypt provided by state (government funded) universities. There have been concerns from all stakeholders about the graduates’ knowledge and skills. The chronic problems with higher education in Egypt in general have been previously reported in the Literature, but this paper provides insights form engineering academics with many years of experience in Egyptian engineering education and a fresh look from a business perspective at the phenomenon. In this manuscript, the institutions are analyzed using the integrated business anatomy model, in order to identify the underlying causes of the problems observed. The structural, operational and environmental (both external and internal) challenges that lead to the current status are clearly detected. The analysis highlighted several constraints that hinder radical reforms. Amongst these constraints is the legal and organizational framework in which the state funded universities operate. Other social, technological and economic factors also play important parts. The recipe for improvement provided by the authors has taken all these elements into consideration. This work hopes to provide focus and direction for future reform efforts.
Endurance exercise‐induced and mental fatigue and the brain
Authors: Meeusen Romain , Van Cutsem Jeroen , Roelands Bart
Published: March 2020

New Findings

What is the topic of this review?

It provides an overview of the recent papers linking brain neurotransmission with exercise‐induced and/or mental fatigue.

What advances does it highlight?

The noradrenergic neurotransmitter system hastens central fatigue during prolonged exercise, a finding that coincides with a faster rate of increase in the rating of perceived exertion. 2) Mental fatigue affects several neurotransmitter systems, with presumably an important role for dopamine and adenosine, in multiple brain regions such as the prefrontal cortex and the anterior cingulate cortex.

In sports and exercise science, fatigue is an elusive concept that has important implications in performance during exercise. It has been described in many ways (tiredness, exhaustion, lethargy or weariness) and describes a physical and/or mental state of being tired and lack of energy. Exercise‐induced fatigue can be defined as an acute impairment of exercise performance, and a distinction has been made between peripheral and central fatigue. Mental fatigue can be defined as a psychobiological state caused by prolonged exertion that has the potential to reduce cognitive performance and exercise performance. Recent studies have given clear indications that brain catecholamines are involved in the onset of fatigue during endurance exercise. Evidence is provided indicating that the noradrenergic neurotransmitter system hastens central fatigue, a finding that coincides with a faster rate of increase in the rating of perceived exertion. Brain neurotransmission is also suggested to play an important role in mental fatigue. Several neurotransmitter systems might be implicated (with the most important role for dopamine and adenosine) in multiple brain regions, such as the prefrontal cortex and the anterior cingulate cortex, and the summation of these alterations might explain the impairment in endurance performance in a mentally fatigued state. Obviously, we have to keep in mind that fatigue is a very complex construct and that, besides brain neurochemistry, several other factors play a role in its onset.
Development of Micro-Diesel Injector Nozzles via MEMS Technology and Effects on Spray Characteristics
Authors: Baik Seunghyun , Blanchard James P. , Corradini Michael L.
Published: March 2020

Micro-machined planar orifice nozzles have been developed and used with commercially produced diesel injection systems. Such a system may have the capability to improve the spray characteristics in DI diesel engines. The availability of a MEMS (Micro-Electro-Mechanical-Systems) processing sequence supported the construction of micro-planar orifice nozzles, and micro-systems technology was also employed in our macro-instrumentation.

To demonstrate this process, fourteen MEMS nozzles were fabricated with deep X-ray lithography and electroplating technology. The nozzles are made of 78% nickel and 22% iron alloy. The circular orifice diameters were varied from 40 to 260 microns and the number of orifices varied from one to 169. Three plates with non-circular orifices were also fabricated to examine the effect of orifice shape on spray characteristics. These nozzles were then attached to commercial injectors and the associated injection systems were used for the spray experiments. Given these novel injection systems, jet spray characteristics of micro-machined nozzles were investigated experimentally at two different injection pressures (around 25 MPa and 80 MPa). Local drop sizes were measured by the laser diffraction technique, and the average drop sizes of the whole sprays were measured by the light extinction technique. Current test results show expected qualitative trends in spray kinematics and drop size, but the quantitative magnitudes of the behavior are less dependent on geometry than first anticipated. The spray kinematics and drop sizes were found to depend primarily on the total mass flow area regardless of single or multi-hole or different orifice shape. Non-planar configurations are under development and may show improved performance.
Modeling NO and Soot Emissions With Gas Compressibility
Authors: Wasfy Hatem M. , Lee Chia-fon F.
Published: March 2020

A multidimensional engine combustion code was used to model NO and soot emissions from a heavy duty Cummins Diesel engine with a compression ratio of 16. The code solves the gas calculation in a moving curvilinear coordinate system. The code includes a 13 species chemistry model that calculates the rate of formation of each species from the fuel conversion time and the species equilibrium concentration. The code also models fuel injection, spray impingement and secondary spray breakup. The engine was tested with 10% EGR in the intake by mass, a swirl ratio of 2.1 and an engine speed of 1500 rpm. The engine was tested at 3 different injection timings. The consequence of including compressibility effects is also studied. The Redlich-Kwong model was used to calculate the deviation of the gases within the combustion chamber from ideal gas behavior. The computational results were compared to the values of pressure, NO and soot emissions obtained from experiments. At the high compression ratio that the engine operates under, the ideal gas equation was found to under-predict the peak cylinder pressure by about 4%. The soot emissions were closely matched in both value and trend. Due to the inaccuracy of the equilibrium-based chemical model, the calculated NO emissions were higher than the experimental values. The evolution of the NO and soot emissions during the cycle was studied. The processes that form these emissions were identified.
High Efficiency and Low NOx Gas Engines for Co-Generation Markets
Authors: Goto Satoru , Nakayama Sadao , Ono Yoshiharu , Nishi Yoshifumi
Published: March 2020

Lean-burn gas engines are operating worldwide because of having an advantage of lower NOx emission and higher thermal efficiency than those of stoichiometric gas engines. The modern lean-burn gas engines, especially medium and large size, have the pre-combustion chamber technology. On the contrary, there are some problems that originate in the spark plug. Particularly near the ignition plug located in the center, the fuel gas density is lean, affected by the lean-gas mixture coming from the main combustion chamber during the compression stroke and the fuel gas density near the wall is rich. The lifetime of ignition plug is likely to be shorter than those used in the conventional theoretical mixture gas combustion engine, because the required voltage for the plug is high, which reaches 20–25 kV or more.

The authors and their colleagues have studied a combustion method of using micro-pilot fuel oil instead of spark plug as an ignition source in recent four years to provide a solution for the above mentioned technical problems. The energy of micro-pilot fuel oil is equivalent to 1% of the total thermal input, but the energy of the pilot fuel oil is several thousands times of the spark ignition. According to the author’s study, NOx emission level is defined by the amount of pilot fuel oil. But only about 1% fuel can meet the NOx target. NOx emission level meets TA-Luft of 500 mg/m3N @ 5% O2. Even the regulation of 200 ppm @ 0% O2 in the Japanese large cities can be achieved, this level is almost corresponding to the half TA-Luft.

This paper describes the performance being desired for gas engines through the service-experience in co-generation fields and also describes the newly developed gas engine corresponding to a 1000 kW class, which has micro-pilot fuel oil ignition method. This engine has the same performance of a diesel engine, BMEP of 2.3 MPa and brake thermal efficiency of 43%.
Characteristics of Premixed Combustion Type Diesel Engine Using Hollow Cone Spray
Authors: Obokata Tomio , Ishima Tsuneaki , Shiga Seiichi , Eguro Yousuke , Matsuda Tomoyuki , Murakami Akira , Long Wuqiang , Yang Xiaofeng , Liu Chanlii
Published: March 2020

To realize the pre-mixed combustion type Diesel engine, analyses of the wide-angle conical spray flow and its application to the direct injection Diesel engine have been made. In the present work, the spray was evaluated by high speed flow visualization, particle image velocimetry (PTV) measurement, phase Doppler anemometer (PDA) measurement and numerical simulation by KTVA-3V code, and finally the combustion and exhaust characteristics of the proposed engine are examined.

The penetration and the shape of the conical sprays under different ambient pressures (0.1, 1.0 and 2.0 MPa) are obtained experimentally and with numerical simulations. Generally, good agreements between them are achieved. It is also cleared that the spray formation is strongly influenced by the surrounding pressure. PIV measurements show the initial development of the spray. The maximum velocity is about 80 m/s, which is almost in the same range as that obtained by the PDA measurements.

For the combustion experiment, the excess air ratio was set at 3.1 and 2.5. The engine speed was varied from 1000 to 2000 rpm. Expected premixed combustion region is realized at around the fuel injection timing prior to 65 degree BTDC, where NOx and soot emissions are almost zero at the excess air ratio of 3.1.
Dual-Fuel System for Heavy Duty Truck Engines
Authors: Asad Usman , Shafique Umar A.
Published: March 2020

Increasing emphasis on natural gas as a clean, economical and abundant fuel advocates its increasing use in transportation applications. In developing countries like Pakistan and India where, more than 80% of the goods are transported by trucks and where natural gas is available in abundance, development of natural gas conversion systems for heavy-duty truck engines offers a viable option to replace the use of expensive imported fuels.

A complete dual-fuel (natural gas/diesel) conversion system developed using mostly commercially available components, for the Hino EC-100 diesel engine is described. Both diesel and natural gas operating modes are possible, without undermining normal engine performance as a diesel. The conversion system has performance similar to the ‘straight diesel’ operation, with comparable efficiency at full load. Furthermore, particulate and oxide of nitrogen (NOx) emissions are considerably lower than on diesel, however, carbon monoxide and hydrocarbon exhaust emissions are higher, particularly at light load.
Structured Model of Crankshaft in the Simulation of Engine Dynamics With AVL/EXCITE
Authors: Parikyan Tigran , Resch Thomas , Priebsch Hans H.
Published: March 2020

The paper presents a new concept of dynamic model of crankshaft — the structured model. The theory behind this type of model and the methodology of its use are discussed in detail, and the place of the new model in the process of dynamic strength evaluation of crankshafts is shown.

The “Shaft Modeler” — a graphical pre-processor, specially developed for rapid generation of structured models to be used in dynamic simulation with AVL/EXCITE — is shortly described.

The advantages of the new modeling methodology are illustrated by application examples. The structured model is shown to closely approximate the modal behavior of the volumetric FE-model. The results of dynamic simulation using structured model show a good correlation with the test-bed measurements, as well as with the calculations based on condensed (dynamically reduced) volumetric FE-model.
Engine Torque Non-Uniformity Evaluation Using Instantaneous Crankshaft Speed Signal
Authors: Cavina Nicolò , Ponti Fabrizio
Published: March 2020

The paper presents the development of a methodology for evaluating the torque non-uniformity between the various cylinders of an Internal Combustion Engine (ICE). This non-uniformity can be due, for example, to pathological operating conditions such as misfires or misfuels, as well as to other abnormal operating conditions. Between the nominal torque production and the one corresponding to the absence of combustion there exist, in fact, a series of possible intermediate conditions. Each of them corresponds to a value of produced torque that lies between the nominal value and the one corresponding to the lack of combustion (due for example to statistical dispersion in manufacturing or aging in the injection system).

The diagnosis of this type of non-uniformity is a very important issue in today’s engine control strategies design. The use of the developed methodology should in fact allow the control strategy to adopt the appropriate interventions if the diagnosed non-uniformity is related to different behavior of the injectors.

In order to evaluate this torque production variability between the various cylinders, information hidden in the instantaneous crankshaft speed fluctuations has been processed using a suitable methodology. The procedure has been validated running a supercharged 2.0 liters V6 engine, and a 1.2 liters L4 engine, in a test cell. During the tests, the in-cylinder pressure signal has been acquired together with the instantaneous engine speed, in order to determine a correlation between speed fluctuations and the indicated torque produced by each cylinder. The actual cylinder by cylinder torque non-uniformity can then be evaluated on-board by processing engine speed.

The procedure is able to diagnose the absence of combustion (due for example to a misfire or a misfuel) as well as abnormal combustions that do not necessarily involve lack of combustion, with the accuracy needed for on-board use. Control interventions to injection and ignition time commands of one or more cylinders should in most cases be able to re-establish torque production uniformity.
Analytical Modeling of Cylinder Head Distortion to Eliminate Intake Valve Burning
Authors: Chang Cherng-Chi , Wistehuff William
Published: March 2020

Intake valve seat recession and subsequent valve leakage were experienced during the late development phase of a new DOHC aluminum engine. This type of failure was not observed in the earlier development phase during engine break-in.

To resolve this valve burning issue, a three-dimensional finite element model was used to study the thermal/mechanical behavior of this engine. A parallel experimental program was conducted to evaluate the effect of the hardware changes between the early and late engine development phases on engine performance. The experimental effort also provided engine temperature and measured distortion data for validating the analytical model. The finite element analysis was able to identify the root cause of this condition and to propose structural modifications to remedy this problem rapidly by predicting the distortion and stress distribution within the cylinder head.
Design of a Rotary Vane Compressor by Genetic Algorithms
Authors: Huang Yuan Mao , Tasy San Nan
Published: March 2020

The genetic optimization algorithm method is used to design rotary compressors with sliding vanes. After the air properties, volume segment, compression power, loadings and stresses of vanes, friction forces and power loss are calculated, the objective function of the maximum efficiency and the constrained conditions can be derived and integrated. Using the ambient air conditions and the properties of Vespel, the effects of the mutation rate, crossover rate and population size of the genetic algorithm on the design parameters are studied. These design parameters include the major axis length, minor axis length, angular locations of inlet and outlet ports and rotational speed of the compressor, the thickness, depth and height of vanes, and the polytropic exponent. The efficiency of the compressor increases to 0.55 compared with the value of 0.4 obtained from the existing data.
Misconceptions in interpretation of nitrogen chemistry from x-ray photoelectron spectra
Authors: Artyushkova Kateryna
Published: March 2020

This perspective explores the complexity of nitrogen chemistry and its interpretation from high-resolution x-ray photoelectron spectra by examining metal-nitrogen-doped carbon systems used in many technological applications. Current understanding of factors contributing to nitrogen 1s photoelectron spectroscopic signature is reviewed, and limitations on assigning precise chemistries to individual spectral ranges are discussed. The importance of proper curve fitting of XPS spectra based on appropriate peak widths and shapes for correct data interpretation is highlighted. Appropriate peak fitting and chemical identification are critical to developing structure-to-property correlations for functional materials in which nitrogen chemistry plays a vital role.
Impacts on access resistance of InP high electron mobility transistors from wafer processing
Authors: Ma Rubin , Lapointe Jean , Storey Craig , Poole Philip , Jiang Frank , Seyfollahi Alireza , Walker Alexandre W. , Noël Jean-Paul , Kam Alicia , Densmore Adam
Published: March 2020

In this work, the authors evaluated the access resistance of InP high electron mobility transistors (HEMTs) and their degradation during wafer processing. The transfer resistance, which was rarely separated from other components of the total access resistance of InP HEMTs in the literature, was found to be the dominant component of the access resistance. It was also found that the transfer resistance degraded during wafer processing. The selection of the ohmic metal stack and its impact on both the metal-cap contact resistance and the transfer resistance was also investigated. The observations in their experiments and relevant discussions in the report are expected to be useful in the identification of improvement opportunities in both material growth and wafer fabrication of InP HEMTs.
Audio-visual preferences, perception, and use of water features in open-plan offices
Authors: Abdalrahman Zanyar , Galbrun Laurent
Published: March 2020

This paper examines the use of water features for masking irrelevant speech and improving the soundscape of open-plan offices. Two laboratory experiments were carried out, as well as acoustic simulations and field tests. Experiment 1 aimed to identify the preferred sound level of water sounds against irrelevant speech. Experiment 2 examined the audio-only and audio-visual preferences and perception of waterscapes. Acoustic simulations and field tests examined the impact of design factors. The results showed that, when played against a constant level of irrelevant speech of 48 dBA, people prefer to listen to water sounds of 42–48 dBA (45 dBA being best). These results and results from previous research suggest that water sounds work mainly as informational maskers rather than energetic maskers. Furthermore, the introduction of a water feature improved the perception of the sound environment, and adding visual stimuli improved perception by up to 2.5 times. Acoustic simulations indicated that features at each corner and one at the center (or a single feature with an array of speakers) can provide appropriate masking for a large open-plan office, whilst field tests showed that water sounds decrease the distraction and privacy distances significantly (clusters of workstations benefitting more than rows of workstations).
The Effect of Exercise Training on Total Daily Energy Expenditure and Body Composition in Weight-Stable Adults: A Randomized, Controlled Trial
Authors: Hand Gregory A. , Shook Robin P. , O’Connor Daniel P. , Kindred Madison M. , Schumacher Sarah , Drenowatz Clemens , Paluch Amanda E. , Burgess Stephanie , Blundell John E. , Blair Steven N.
Published: March 2020

Background: The present study examined, among weight-stable overweight or obese adults, the effect of increasing doses of exercise energy expenditure (EEex) on changes in total daily energy expenditure (TDEE), total body energy stores, and body composition. Methods: Healthy, sedentary overweight/obese young adults were randomized to one of 3 groups for a period of 26 weeks: moderate-exercise (EEex goal of 17.5 kcal/kg/wk), high-exercise (EEex goal of 35 kcal/kg/wk), or observation group. Individuals maintained body weight within 3% of baseline. Pre/postphysical activity between-group measurements included body composition, calculated energy intake, TDEE, energy stores, and resting metabolic rate. Results: Sixty weight-stable individuals completed the protocols. Exercise groups increased EEex in a stepwise manner compared with the observation group (P < .001). There was no group effect on changes in TDEE, energy intake, fat-free mass, or resting metabolic rate. Fat mass and energy stores decreased among the females in the high-exercise group (P = .007). Conclusions: The increase in EEex did not result in an equivalent increase in TDEE. There was a sex difference in the relationship among energy balance components. These results suggest a weight-independent compensatory response to exercise training with potentially a sex-specific adjustment in body composition.
Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2)
Authors: Li Ruiyun , Pei Sen , Chen Bin , Song Yimeng , Zhang Tao , Yang Wan , Shaman Jeffrey
Published: March 2020

Undetected cases

The virus causing coronavirus disease 2019 (COVID-19) has now become pandemic. How has it managed to spread from China to all around the world within 3 to 4 months? Li
et al.
used multiple sources to infer the proportion of early infections that went undetected and their contribution to virus spread. The researchers combined data from Tencent, one of the world's largest social media and technology companies, with a networked dynamic metapopulation model and Bayesian inference to analyze early spread within China. They estimate that ∼86% of cases were undocumented before travel restrictions were put in place. Before travel restriction and personal isolation were implemented, the transmission rate of undocumented infections was a little more than half that of the known cases. However, because of their greater numbers, undocumented infections were the source for ∼80% of the documented cases. Immediately after travel restrictions were imposed, ∼65% of cases were documented. These findings help to explain the lightning-fast spread of this virus around the world.

Science
, this issue p.
489
Time to pull together
Authors: Thorp H. Holden
Published: March 2020

It is now hard to imagine a world that isn't permanently changed by coronavirus disease 2019 (COVID-19). We don't know whether this is an event like 9/11 or the 2008 global financial crisis—where life will mostly go back to the way it was—or whether the institutions and practices of the future will transform in ways that we can't yet imagine. The success of the world's scientists—along with strong political and social leadership—will determine which scenarios unfold, so it is time to focus on what we can all do to help.
CosR Is a Global Regulator of the Osmotic Stress Response with Widespread Distribution among Bacteria
Authors: Gregory Gwendolyn J. , Morreale Daniel P. , Boyd E. Fidelma
Published: March 2020

Vibrio parahaemolyticus
can accumulate compatible solutes via biosynthesis and transport, which allow the cell to survive in high salinity conditions. There is little need for compatible solutes under low salinity conditions, and biosynthesis and transporter systems need to be repressed. However, the mechanism(s) of this repression is not known. In this study, we showed that CosR played a major role in the regulation of multiple compatible solute systems. Phylogenetic analysis showed that CosR is present in all members of the
Vibrionaceae
family as well as numerous
Gammaproteobacteria
. Collectively, these data establish CosR as a global regulator of the osmotic stress response that is widespread in bacteria, controlling many more systems than previously demonstrated.
Transmission of Koala Retrovirus from Parent Koalas to a Joey in a Japanese Zoo
Authors: Hashem Md Abul , Maetani Fumie , Kayesh Mohammad Enamul Hoque , Eiei Taiki , Mochizuki Kyoya , Ito Ayaka , Sakurai Hiroko , Asai Takayuki , Tsukiyama-Kohara Kyoko
Published: March 2020

KoRV is unique among retroviruses in that one strain (KoRV-A) is undergoing endogenization, whereas the other main subtype (KoRV-B) and another subtype (KoRV-C) are reportedly exogenous strains. Its transmission and pathogenesis are of interest in the study of retroviruses and are crucial for any conservation strategy geared toward koala health. This study provides new evidence on the modes of KoRV transmission from parent koalas to their joey. We found vertical transmission of KoRV-A, confirming its endogenization, but with closer conservation between the joey and its sire than its dam (previous reports on joeys are rare but have postulated dam-to-joey vertical transmission). This is also the first report of a KoRV-B-negative joey from KoRV-B-positive parents, contrasting with the few previous reports of 100% transmission of KoRV-B from dams to joeys. Thus, the results in this study give some novel insights for the transmission mode of KoRV.
Norovirus Replication in Human Intestinal Epithelial Cells Is Restricted by the Interferon-Induced JAK/STAT Signaling Pathway and RNA Polymerase II-Mediated Transcriptional Responses
Authors: Hosmillo Myra , Chaudhry Yasmin , Nayak Komal , Sorgeloos Frederic , Koo Bon-Kyoung , Merenda Alessandra , Lillestol Reidun , Drumright Lydia , Zilbauer Matthias , Goodfellow Ian
Published: March 2020

Noroviruses are a major cause of gastroenteritis worldwide, and yet the challenges associated with their growth in culture have greatly hampered the development of therapeutic approaches and have limited our understanding of the cellular pathways that control infection. Here, we show that human intestinal epithelial cells, which represent the first point of entry of human noroviruses into the host, limit virus replication by induction of innate responses. Furthermore, we show that modulating the ability of intestinal epithelial cells to induce transcriptional responses to HuNoV infection can significantly enhance human norovirus replication in culture. Collectively, our findings provide new insights into the biological pathways that control norovirus infection but also identify mechanisms that enhance the robustness of norovirus culture.
Genetic Manipulation of Human Intestinal Enteroids Demonstrates the Necessity of a Functional Fucosyltransferase 2 Gene for Secretor-Dependent Human Norovirus Infection
Authors: Haga Kei , Ettayebi Khalil , Tenge Victoria R. , Karandikar Umesh C. , Lewis Miranda A. , Lin Shih-Ching , Neill Frederick H. , Ayyar B. Vijayalakshmi , Zeng Xi-Lei , Larson Göran , Ramani Sasirekha , Atmar Robert L. , Estes Mary K.
Published: March 2020

Several studies have demonstrated that secretor status is associated with susceptibility to human norovirus (HuNoV) infection; however, previous reports found that FUT2 expression is not sufficient to allow infection with HuNoV in a variety of continuous laboratory cell lines. Which cellular factor(s) regulates susceptibility to HuNoV infection remains unknown. We used genetic manipulation of HIE cultures to show that secretor status determined by
FUT2
gene expression is necessary and sufficient to support HuNoV replication based on analyses of isogenic lines that lack or express FUT2. Fucosylation of HBGAs is critical for initial binding and for modification of another putative receptor(s) in HIEs needed for virus uptake or uncoating and necessary for successful infection by GI.1 and several GII HuNoV strains.
Activity and Metabolic Versatility of Complete Ammonia Oxidizers in Full-Scale Wastewater Treatment Systems
Authors: Yang Yuchun , Daims Holger , Liu Yang , Herbold Craig W. , Pjevac Petra , Lin Jih-Gaw , Li Meng , Gu Ji-Dong
Published: March 2020

The discovery of comammox in the genus
Nitrospira
changes our perception of nitrification. However, genomes of comammox organisms have not been acquired from full-scale WWTPs, and very little is known about their survival strategies and potential metabolisms in complex wastewater treatment systems. Here, four comammox metagenome-assembled genomes and metatranscriptomic data sets were retrieved from two full-scale WWTPs. Their impressive and—among nitrifiers—unsurpassed ecophysiological versatility could make comammox
Nitrospira
an interesting target for optimizing nitrification in current and future bioreactor configurations.
Snake Deltavirus Utilizes Envelope Proteins of Different Viruses To Generate Infectious Particles
Authors: Szirovicza Leonora , Hetzel Udo , Kipar Anja , Martinez-Sobrido Luis , Vapalahti Olli , Hepojoki Jussi
Published: March 2020

Deltaviruses need a coinfecting enveloped virus to produce infectious particles necessary for transmission to a new host. Hepatitis D virus (HDV), the only known deltavirus until 2018, has been found only in humans, and its coinfection with hepatitis B virus (HBV) is linked with fulminant hepatitis. The recent discovery of deltaviruses without a coinfecting HBV-like agent in several different taxa suggested that deltaviruses could employ coinfection by other enveloped viruses to complete their life cycle. In this report, we show that snake deltavirus (SDeV) efficiently utilizes coinfecting reptarena- and hartmaniviruses to form infectious particles. Furthermore, we demonstrate that cells expressing the envelope proteins of arenaviruses and orthohantaviruses produce infectious SDeV particles. As the envelope proteins are responsible for binding and infecting new host cells, our findings indicate that deltaviruses are likely not restricted in their tissue tropism, implying that they could be linked to animal or human diseases other than hepatitis.
Role of Plasmodium falciparum Protein GEXP07 in Maurer’s Cleft Morphology, Knob Architecture, and P. falciparum EMP1 Trafficking
Authors: McHugh Emma , Carmo Olivia M. S. , Blanch Adam , Looker Oliver , Liu Boyin , Tiash Snigdha , Andrew Dean , Batinovic Steven , Low Andy J. Y. , Cho Hyun-Jung , McMillan Paul , Tilley Leann , Dixon Matthew W. A.
Published: March 2020

The trafficking of the virulence antigen
Pf
EMP1 and its presentation at the knob structures at the surface of parasite-infected RBCs are central to severe adhesion-related pathologies such as cerebral and placental malaria. This work adds to our understanding of how PfEMP1 is trafficked to the RBC membrane by defining the protein-protein interaction networks that function at the Maurer’s clefts controlling PfEMP1 loading and unloading. We characterize a protein needed for virulence protein trafficking and provide new insights into the mechanisms for host cell remodeling, parasite survival within the host, and virulence.
Metamorphic evolution of high-pressure felsic and pelitic granulites from the Qianlishan Complex and tectonic implications for the Khondalite Belt, North China Craton
Authors: Wu Shangjing , Yin Changqing , Davis Donald W. , Zhang Jian , Qian Jiahui , Qiao Hengzhong , Xia Yanfei , Liu Jingna
Published: March 2020

High-pressure felsic granulites in association with pelitic granulites are widely distributed in the Qianlishan Complex of the Khondalite Belt, North China Craton. A link between “inter-layered” felsic and pelitic granulites was established based on comprehensive metamorphic analysis, revealing that they record similar metamorphic stages: peak pressure (M1), post-peak decompression (M2), and late retrograde cooling (M3) stages. Felsic granulites experienced high-pressure metamorphism up to ∼12 kbar, while pelitic granulites estimated peak pressure is 11–15 kbar. The decompression stage (M2) is indicated by cordierite + sillimanite symplectite and/or cordierite coronae with conditions of 5.7–6.5 kbar/800–835 °C in pelitic granulites, and by garnet-sillimanite assemblages with conditions of >6.5 kbar/810–865 °C in felsic granulites. The later cooling stage (M3) is marked by sub-solidus biotite-quartz-plagioclase symplectite and later melt crystallization. These mineral assemblages and pressure-temperature (P-T) conditions define clockwise P-T paths involving near-isothermal decompression and near-isobaric cooling, suggesting a continent-continent collisional event. Secondary ion mass spectrometry zircon U-Pb dating yields a consistent metamorphic age of ca. 1.95 Ga, interpreted as peak metamorphism. The results, combined with available data, suggest that the Khondalite Belt formed by collision between the Yinshan and Ordos blocks at ca. 1.95 Ga.