bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of 66kV Isolation Switch V Type Porcelain Column Fracture Insulation Protection Frame
Authors: Li Long , Yang Song , Ren Pengfei , Zheng Liwei , Wang Yilin
Published: April 2021

The mechanical strength of old 66kV disconnect switches (V-type porcelain column type) in outdoor substations has been affected by weather and daily operation for a long time, and the change of internal force of porcelain column caused by external force during open and closed circuit operation is very likely to cause porcelain column fracture, which poses a safety hazard to the safety of people and equipment. In order to ensure the safety of personal and equipment during operation and maintenance of the switch, this paper proposes a kind of insulation protection frame for 66kV disconnecting switch V-type porcelain column fracture. The simple structure, flexible operation, safety and reliability of this protective frame have been proved by practice that after using this protective frame in work, the efficiency of work is obviously improved and the safety of personal and equipment is effectively guaranteed.
Problems and Countermeasures in the Budget Cost Control of Decoration Engineering
Authors: Yujia
Published: April 2021

With the rapid development of China's economy and technology, great progress has been made in all fields. Especially in the field of decoration engineering, great breakthroughs have also been made. The strength of enterprises continues to increase, and the gap between enterprises continues to narrow. In this context, how to strengthen the cost control of decoration enterprises and continuously improve their own strength has become an urgent problem. Based on this, this article carried out the budget analysis of the decoration project and analyzed the problems existing in the enterprise cost budget control. Finally, this paper proposes a series of measures such as unifying the cost budget specifications, continuously improving the project cost budget control system, and strengthening the project cost budget monitoring.
Design of domestic serial and parallel interface module
Authors: Shao Guowei , Sun Quanyu , Yi Sun
Published: April 2021

Domestic serial and parallel interface module is based on domestic high performance FPGA CPCIE module. This type of FPGA has rich logical resources and internal integration of a variety of high-speed interfaces, such as PCIE, high-speed Serdes interface, which can achieve serial port, time system, network and other interfaces design, greatly simplifying the hardware design of the module. The main communication interfaces, PCIE and UART, are realized by the IP core of FPGA, realizing the integration of the main functions on the chip, which greatly improves the flexibility and expansibility of the design.
Dynamic influence of the plane curve radius on vertical- circular overlapping lines of high-speed railway
Authors: Fan Xianghui , Li Bin , Zhang Yongfu , Du Guoqiang , Liu Hua
Published: April 2021

In order to reasonably match the horizontal and vertical sections of high-speed railway lines, the vehicle-line spatial coupling model of the vertical-circular overlapping line is established, based on the multi-body dynamics simulation software SIMPACK,. The dynamic indexes of train passing through vertical-circular overlapping lines are calculated when the radii of different plane curves match the corresponding superelevation value. The results show that: on the vertical-circular overlapping line, it is suggested that the maximum plane curve radius is 9000m.The existence of the convex vertical-circular overlapping line worsens the safety of train operation and passenger comfort. The existence of the concave vertical-circular overlapping line is the opposite, but it increases rail wear and the workload of maintenance. The vertical-circular overlapping line has the most obvious influence on the vertical acceleration and the vertical Sperling index of the body. The vertical acceleration of the body is superimposed at the plane gentle circle point and the starting point of the vertical curve, which has a great impact on the stability of the train operation.
A coupling method for simulating tunnel excavation with block, particle and bar elements
Authors: Li Xiaoguang , Li Changhong , Feng Chun
Published: April 2021

Excavation of tunnel in rock mass refers to complex continuum-discontinuous processes. For capturing the damages of side walls and the supports of bolts/cables, different types of elements shall be used in the same framework. In this work, a novel method is proposed which couples block, particle, and bar elements for simulating the intact rock mass, the broken rock mass, and the supporting system respectively during tunnel excavation. Brittle Mohr-Coulomb fracture constitutive law and tensile fracture constitutive law are introduced for describing the contact behavior between different parts. Penalty springs are adopted for accounting the pre-stresses effects. Moreover, for assuring the proper transitions of forces and displacements between different types of elements, an interpolation coupling approach is presented. Cases considering different tunnel sections and supporting strategies are numerically studied, indicating the reliability of the method.
Rainfall interpolation based on flood simulation in northren China
Authors: Ran-hang Zhao , Lu Zhou , Hua-xing Li , Hong-tao Li , Zhen Qi , Ting Qiu , Tian Gan
Published: April 2021

Due to the short duration, high intensity and sudden intensity of torrential rain, mountain torrents are easily formed in the northern hilly area.The distributed hydrological model is used as the main means of rain-flood forecasting. Rainfall as an important input,its spatial interpolation accuracy and time scale directly affect the forecast results.Therefore, in this paper, the spatial interpolation calculation and analysis of rainstorm process with hourly scale is carried out in the northern hilly area. Taking Licheng district in Jinan as the research area, the spatial interpolation methods, such as IDW,OK and OCK, are used to calculate the spatial interpolation of 16 time-by-time rainstorm processes for 11 typical rainfall with different duration, and the interpolation results are cross-validated and error analysis is carried out.The results show that the accuracy of the collaborative Kriging interpolation considering the elevation is higher in the short duration rainstorm process of the hilly area.
Basic Selection and Analysis of Harbin Ice and Snow World Theater Project
Authors: Zhang Xiaomeng , Liu Wenting , Zhou Yilun , Liu Ziao
Published: April 2021

Harbin Ice and Snow World Project totals 98,000 square meters, consisting of Iceberg Pavilion, Dream Ice and Snow Pavilion, Ice and Snow Show, and Ice and Snow Art Museum.This project mainly introduces the foundation selection and structural design of the Harbin Ice and Snow World Show, verifies the feasibility of the project implementation, and analyzes the rationality of the structural foundation layout through structural design and structural calculation analysis.
Fabricated Green buildings measure the development of new villages
Authors: Yanli Sun , Di Zhang
Published: April 2021

With the renovation of the architectural design concept and the progress of architectural technology, the requirement of green environmental protection in architectural design and construction is increasing in our country. The article mainly explains the development of assembled green buildings in the construction of new countryside. It is hoped that it can provide a reference for relevant units and workers, and promote the development of assembled green building in the new countryside.
Research on Evaluation of Building Industrialization Level Based on BIM Technology
Authors: Xiaoyu He
Published: April 2021

This paper analyzes the application value of BIM technology in industrial building projects and the improvement of building industrialization level. Firstly, an evaluation index system of building industrialization level based on BIM technology is established, which consists of 4 first-level indicators and 16 second-level indicators; then, the Analytic Hierarchy Process is used to determine the corresponding weight value of each index; finally, the BIM platform function is used to collect data, and the fuzzy comprehensive evaluation method is used to calculate the evaluation results of the evaluated objects, so as to realize the effective evaluation of the building industrialization level.
Construction of Safety Evaluation System of Jacking Form Work System Based on Human Factor Theory
Authors: Jia Shilong , Wang Yu , Zhang Zhaofeng
Published: April 2021

The jacking form work is a complex system of construction environment, which is extremely important for human factors control. Establishing a harmonious man-machine-environment relationship is of great help to reduce the construction risk of jacking form work. This paper will establish the evaluation indicators which affecting man-machine-environment system balance. Then the AHP-Fuzzy evaluation method was used to carry out comprehensive evaluation. Finally, the real-life project was taken as an example to evaluate the construction safety level. The result can provide an important direction for construction safety management.
FLAC3D simulation of combined support effect under different prestress parameters of deep soft rock roadway
Authors: Li Jie , Li Xinghua , Liu Fuguang
Published: April 2021

In coal mining, as the mining depth increases, a complex mechanical environment of “high ground stress”, “high ground temperature”, “high karst water pressure”, and “mining disturbance”, namely “three highs and one disturbance” appears. Many roadways have the characteristics of soft rock roadways with large deformation, large ground pressure, difficult support, and high support cost, which brings severe challenges to the safe and efficient production of coal mines. Therefore, it is very important to explore the support technology and support parameters of deep soft rock roadways. In this paper, numerical simulation is used to study the influence of different prestress on the displacement, axial force and vertical stress of the surrounding rock of the roadway in the joint support of deep soft rock roadway. The results show that in the simulation of prestressing 20KN, 40KN, 60KN, and supporting method of bolt and anchor cable combined support, the comprehensive support effect of 60KN prestressed bolt + anchor cable is the best.
Study on Ecosystem Structure and Function of Longji Terrace
Authors: Zhu Xuelian , Xu Delan , Wang Kaijie
Published: April 2021

Longji Terrace, one of the three ancient terraces in China, is a comprehensive tourist scenic spot with agricultural terraces as the main body and integrating natural landscape, cultural landscape and ethnic customs. In this paper, taking Longji Terrace in Guilin as the research object, using geographic information technology to study its ecosystem structure from the aspects of space, components, etc., to explore the material and energy flow patterns of the ecosystem, and to analyze the service functions of the ecosystem, so as to provide basic information for the healthy and sustainable development of the local ecological environment.
Application of the omics sciences to the study of Naegleria fowleri, Acanthamoeba spp., and Balamuthia mandrillaris: current status and future projections
Authors: Rodriguez-Anaya Libia Zulema , Félix-Sastré Ángel Josué , Lares-Villa Fernando , Lares-Jiménez Luis Fernando , Gonzalez-Galaviz Jose Reyes
Published: April 2021

In this review, we focus on the sequenced genomes of the pathogens Naegleria fowleri, Acanthamoeba spp. and Balamuthia mandrillaris, and the remarkable discoveries regarding the pathogenicity and genetic information of these organisms, using techniques related to the various omics branches like genomics, transcriptomics, and proteomics. Currently, novel data produced through comparative genomics analyses and both differential gene and protein expression in these free-living amoebas have allowed for breakthroughs to identify genes unique to N. fowleri, genes with active transcriptional activity, and their differential expression in conditions of modified virulence. Furthermore, orthologous genes of the various nuclear genomes within the Naegleria and Acanthamoeba genera have been clustered. The proteome of B. mandrillaris has been reconstructed through transcriptome data, and its mitochondrial genome structure has been thoroughly described with a unique characteristic that has come to light: a type I intron with the capacity of interrupting genes through its self-splicing ribozymes activity. With the integration of data derived from the diverse omic sciences, there is a potential approximation that reflects the molecular complexity required for the identification of virulence factors, as well as crucial information regarding the comprehension of the molecular mechanisms with which these interact. Altogether, these breakthroughs could contribute to radical advances in both the fields of therapy design and medical diagnosis in the foreseeable future.
Demarcated redness associated with increased vascular density/size: a useful marker of flat-type dysplasia in patients with ulcerative colitis
Authors: Ikebata Akiyoshi , Shimoda Masayuki , Okabayashi Koji , Uraoka Toshio , Maehata Tadateru , Sugimoto Shinya , Mutaguchi Makoto , Naganuma Makoto , Kameyama Kaori , Yahagi Naohisa , Kanai Takanori , Kitagawa Yuko , Kanai Yae , Iwao Yasushi
Published: April 2021

Background and study aims Recent advances in endoscopic equipment and diagnostic techniques have improved the detection of dysplasia in the inflamed mucosa of patients with ulcerative colitis (UC). However, it remains difficult to endoscopically identify flat-type dysplasia which has been formerly recognized as invisible dysplasia.

Patients and methods In this retrospective, single-center study, we endoscopically identified 10 cases of flat-type-predominant dysplasia by targeted biopsy among 38 intramucosal dysplasia lesions from patients with UC who underwent surgical or endoscopic resection from 2007 to 2017. Their endoscopic and histological features were examined, including color changes, intramucosal vascular density/size, and vascular endothelial growth factor (VEGF) expression.

Results All flat-type-predominant dysplasias were endoscopically recognized as demarcated red-colored areas and histologically diagnosed as low- (LGDs) or high-grade dysplasias (HGDs). Immunohistochemical examination using resected specimens revealed that flat-type dysplasia was characterized by significantly increased CD34-positive vascular density (LGDs, 1.7-fold, P < 0.01; HGDs, 2.2-fold, P < 0.01) and size (LGDs, 1.03-fold, P < 0.01; HGDs, 1.11-fold, P < 0.01) in the mucosa, compared to adjacent non-neoplastic areas. Increased numbers of vessels were observed at the base of the mucosa in LGDs, whereas HGDs contained increased/enlarged vessels throughout the mucosa. Moreover, VEGF expression was elevated in all dysplastic epithelia.

Conclusions Demarcated red-colored areas, histologically characterized by an increased vascular density/size in the mucosa, are an endoscopic sign of formerly invisible flat-type dysplasia in patients with UC and should be considered for targeted biopsy. Prospective studies focusing on the mucosal color change for their early detection would be desirable in the future.
Synthesis of [6,6,m]-Tricyclic Compounds via [4+2] Cycloaddition with Au or Cu Catalyst
Authors: Oh Chang Ho , Kang Juyeon , Ham Seunghwan , Seong Chaehyeon
Published: April 2021

We synthesized [6,6,6]- and [6,6,7]-tricyclic compounds via intramolecular [4+2] cycloaddition by gold or copper catalysts. Substrates for cyclization were prepared by coupling reactions between eight types of diyne and four types of aromatic moieties. We have successfully synthesized eleven tricyclic compounds.
Extending the “Reach” of the Short-Scar Facelift with Energy Devices—An Early Report
Authors: Fedok Fred G.
Published: April 2021

Facial rejuvenation has become more popular. A wider breadth of the patient population is seeking procedures to preserve their youthful facial attributes and to remedy age-related deleterious changes. Along with this increasing interest in facial rejuvenation is also the expressed desire for any interventions to be relatively low risk, with limited recovery, and with achievable positive results. Many new technologies have become available in an attempt to improve age-related facial changes. The radiofrequency (RF)-based technologies are largely directed toward skin tightening and toward reducing and remodeling subcutaneous fat. It can be contemplated that the combination of RF-based technology with limited surgical procedures may extend the patient selection for less invasive procedures while improving potential results. This is a report of the combination of radiofrequency technologies—percutaneous and transcutaneous—with short scar face techniques in facial rejuvenation.
Combining Laser Resurfacing and Facial Rejuvenation Surgery
Authors: Hessler Jill L. , Trujillo Oscar
Published: April 2021

Facial aging is a multifactorial process involving skin laxity, volume loss, facial rhytids and solar elastosis. Surgical interventions can address the laxity of the skin and restore volume loss but do not fully correct the texture of the skin. Historically, there were concerns over the safety of combining laser resurfacing with facelifting procedures, but now there is much evidence to support the safe use of this combination treatment. When done appropriately, the combination of laser resurfacing with facial rejuvenation surgery can provide a synergistic effect for optimal clinical results. Here, we review the many laser options available and how they may be combined safely with surgical facial rejuvenation. We also review clinical contexts and candidate selection to provide safe, reliable results and minimize complications.
Voltage–current characteristics of low-pressure discharges in vapors of several alcohols
Authors: Marjanović Jelena , Marić Dragana , Malović Gordana , Petrović Zoran Lj.
Published: April 2021

In this paper, we present the results for voltage–current (V–i) characteristics of dc low-pressure low to moderate current discharges in vapors of alcohols: methanol, ethanol, isopropanol, and n-butanol vapors. These electrical measurements are supported by optical recordings of axial emission profiles from low-current to high-current regimes. The voltage–current characteristics and the corresponding distribution of emission intensities were typically recorded for two pd values, in the left-hand branch of the Paschen curve (0.15 Torr cm) and in the minimum of the Paschen curves (ranging from 0.30 to 0.40 Torr cm for different alcohols selected here). In the recorded V–i characteristics, the different discharge regimes of discharge operation are easily distinguished. Axial profiles of emitted light from the low-current to high-current regimes reveal that heavy particles make up a significant contribution to excitation part in alcohol vapor discharges. In the region of transition from normal to abnormal glow in the methanol vapor discharge, sudden changes of the regime of operation were observed and several diagnostic techniques have been applied to them.
Measurements and characterization of the dynamics of tracer particles in an actin network
Authors: Levin Maayan , Bel Golan , Roichman Yael
Published: April 2021

The underlying physics governing the diffusion of a tracer particle in a viscoelastic material is a topic of some dispute. The long-term memory in the mechanical response of such materials should induce diffusive motion with a memory kernel, such as fractional Brownian motion (fBM). This is the reason that microrheology is able to provide the shear modulus of polymer networks. Surprisingly, the diffusion of a tracer particle in a network of a purified protein, actin, was found to conform to the continuous time random walk type (CTRW). We set out to resolve this discrepancy by studying the tracer particle diffusion using two different tracer particle sizes, in actin networks of different mesh sizes. We find that the ratio of tracer particle size to the characteristic length scale of a bio-polymer network plays a crucial role in determining the type of diffusion it performs. We find that the diffusion of the tracer particles has features of fBm when the particle is large compared to the mesh size, of normal diffusion when the particle is much smaller than the mesh size, and of the CTRW in between these two limits. Based on our findings, we propose and verify numerically a new model for the motion of the tracer in all regimes. Our model suggests that diffusion in actin networks consists of fBm of the tracer particle coupled with caging events with power-law distributed escape times.
Crystallization kinetics of amorphous acetonitrile nanoscale films
Authors: Smith R. Scott , Tylinski M. , Kimmel Greg A. , Kay Bruce D.
Published: April 2021

We measure the isothermal crystallization kinetics of amorphous acetonitrile films using molecular beam dosing and reflection adsorption infrared spectroscopy techniques. Experiments on a graphene covered Pt(111) substrate revealed that the crystallization rate slows dramatically during long time periods and that the overall kinetics cannot be described by a simple application of the Avrami equation. The crystallization kinetics also have a thickness dependence with the thinner films crystallizing much slower than the thicker ones. Additional experiments showed that decane layers at both the substrate and vacuum interfaces can also affect the crystallization rates. A comparison of the crystallization rates for CH3CN and CD3CN films showed only an isotope effect of ∼1.09. When amorphous films were deposited on a crystalline film, the crystalline layer did not act as a template for the formation of a crystalline growth front. These overall results suggest that the crystallization kinetics are complicated, indicating the possibility of multiple nucleation and growth mechanisms.
On the mechanism underlying the elimination of nitrogen-oxygen shallow thermal donors in nitrogen-doped Czochralski silicon at elevated temperatures
Authors: Zhao Tong , Hua Chenqiang , Lan Wu , Sun Yuxin , Wu Defan , Lu Yunhao , Ma Xiangyang , Yang Deren
Published: April 2021

Nitrogen-doped Czochralski (NCZ) silicon has been a base material for integrated circuits. The interaction between nitrogen (N) and interstitial oxygen (Oi) atoms in the low temperature regime (300–650 °C), which leads to N–O complexes in the form of NOx (x = 1, 2, or 3), forms a series of shallow thermal donors (denoted as N–O STDs). Such N–O STDs are detrimental to the stability of electrical resistivity of NCZ silicon. In this work, we have experimentally investigated the elimination of N–O STDs in NCZ silicon by means of conventional furnace anneal (CFA) and rapid thermal anneal at elevated temperatures ranging from 900 to 1250 °C, aiming to explore the underlying mechanism. It is found that most of the N–O STDs formed in NCZ silicon can be eliminated by a very short period of anneal at the aforementioned temperatures, providing solid evidence for the viewpoint that the elimination of N–O STDs is ascribed to the decomposition of NOx complexes. Somewhat unexpectedly, the residual N–O STDs are much more after the 1250 °C/2 h CFA than after the 900 °C/2 h or 1000 °C/2 h counterpart, which is found to be due to the fact that more nitrogen pairs [(N2)s] are remaining after the 1250 °C/2 h CFA. It is proposed that most of the (N2) atoms are involved in the growth of grown-in oxide precipitates during the 900 or 1000 °C/2 h CFA. The first-principles calculations and molecular dynamics simulation indicate that the elimination of N–O STDs is essentially ascribed to the destruction of “NO ring” that is the core of NOx complexes. Furthermore, based on the experimental and theoretical results, we have made a thorough thermodynamic analysis to account for the details of elimination of N–O STDs as revealed in this work. It is believed that our experimental and theoretical studies have gained more insight into the N–O STDs in NCZ silicon.
The threat of zoonotic coronaviruses
Authors: Gartner Matthew J , Subbarao Kanta
Published: April 2021

Since 2002, three zoonotic coronaviruses (CoV), SARS-CoV, MERS-CoV and SARS-CoV-2 have emerged in humans, establishing that emergence of coronaviruses from animal reservoirs represents a significant pandemic threat. SARS-CoV and MERS-CoV led to smaller epidemics with very high case fatality rates while SARS-CoV-2 resulted in a global pandemic. These zoonotic coronaviruses have their likely origins in bat species and they transmit to humans through intermediate hosts. Coronaviruses can occasionally jump between host species due to their high rate of recombination. Pandemic preparedness requires surveillance in animals and occupationally exposed humans and prevention and treatment strategies that have broad activity against coronaviruses.
Perspectives for antivirals to limit SARS-CoV-2 infection (COVID-19)
Authors: De Clercq Erik
Published: April 2021

Compared with vaccines, antivirals for curbing COVID-19 (SARS-CoV-2 infection) have been developed at a much lower pace. Favipiravir has proven efficacious (in hamsters) but only at a very high dose which may not be feasible in humans. Remdesivir is the sole antiviral approved by the US FDA, but it has not been extensively evaluated for its safety. EIDD-1931 and EIDD-2801 have not been evaluated clinically. Mpro (protease) inhibitors likewise need to be subjected to clinical efficacy and safety studies. Remdesivir is a C-nucleoside and this class of compounds should be further evaluated. Polyanionic substances interfering with virus adsorption to the host cells have not been explored. They may possibly be administered by inhalation. Corticosteroids (such as dexamethasone), while virus-stimulating rather than inhibitory, may counteract the ‘cytokine storm’. Combination of (two or more of) the compounds mentioned above may offer an increased benefit through a synergistic interaction.
How university diversity rationales inform student preferences and outcomes
Authors: Starck Jordan G. , Sinclair Stacey , Shelton J. Nicole
Published: April 2021

Significance

There are numerous reasons why institutions of higher education may choose to embrace diversity. A common rationale sanctioned by the US Supreme Court is that diversity provides compelling educational benefits and is thus instrumentally useful. We show that such instrumental rationales are the predominant rationale for diversity efforts in American higher education, are preferred by White Americans and not by Black Americans, that they are expected to advantage White Americans, and that they correspond to greater racial disparities in academic achievement. Overall, these findings suggest that the rationales behind universities’ embrace of diversity have nonlegal consequences that should be considered in institutional decision making.
Cyclosorus parasiticus (parasitic maiden fern).
Authors: Buddenhagen Chris
Published: April 2021

Cyclosorus parasiticus (=Christella parasitica) is a fern that is widespread throughout tropical Asia and some of the Polynesian islands, and also found in a few other parts of the tropics; its spores are likely to be spread long distances by the wind. It is not certain that it was introduced anywhere by humans, but this is thought to be probably the case in Hawaii (although the means of introduction is not known); it is regarded there as a threat to some native plants (sources differ as to the conservation significance of some of these). Throughout its range it can be a weed of plantations, but it is not a regulated pest anywhere. It is sometimes used medicinally.
Cotton leaf curl virus (leaf curl disease of cotton).
Authors: Brown Judith K
Published: April 2021

Leaf curl disease of cotton caused by the CLCuD-complex of begomoviruses is endemic to Pakistan and India and perhaps other nearby locales in south Asia. It has been introduced from there to China and the Philippines on ornamental plants, from where it has spread to infect cotton and okra in China. Losses are difficult to assess, but early estimates (pre-1990) range up to 20% when infection occurs early in the growing season and/or with highly susceptible cultivars. Viruliferous whiteflies on infested/infected plants harbouring CLCuD-begomoviruses imported to other cotton-growing countries, in particular, are of concern in preventing introduction under optimal circumstances. No seed transmission is known to occur.
Lilioceris lilii (lily leaf beetle).
Authors: Kenis Marc
Published: April 2021

L. lilii is a Eurasian chrysomelid beetle that was first found in Quebec, Canada, in 1943, from where it has spread to several Canadian Provinces, and Vermont and Maine in the USA. It was also reported in Boston, Massachusetts, in 1992, and it is now found in several New England States. It is also alien and invasive in the UK and, probably, in Northern Europe. The beetle most probably spreads with the sale and movement of potted lilies, flowering bulbs or cut flowers. In countries where it is invasive, it is a serious pest of cultivated lilies and fritillaries. Without control methods, leaves and flowers are totally defoliated by larvae. In North America, it also represents a threat to native lilies.
Miconia calvescens (miconia).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro , Meyer Jean-Yves , Loope Lloyd , Brooks Simon
Published: April 2021

A datasheet on Miconia calvescens covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Rhus typhina (staghorn sumac).
Authors: Jiang Gao Ming , Wang Guang-mei , Yang Jing-cheng
Published: April 2021

A datasheet on Rhus typhina covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Annona reticulata (bullock's heart).
Authors: Datiles Marianne Jennifer , Acevedo-Rodríguez Pedro
Published: April 2021

A datasheet on Annona reticulata covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Plyometric exercise enhances twitch contractile properties but fails to improve voluntary rate of torque development in highly trained sprint athletes
Authors: Zimmermann Haiko Bruno , Costa Filipe Estácio , Sakugawa Raphael , MacIntosh Brian , Diefenthaeler Fernando , Dal Pupo Juliano
Published: April 2021

Purpose: The objective of this study was to evaluate a plyometric conditioning activity (3 sets of 5 countermovement jumps, [CA]) for twitch properties and voluntary knee extension. Methods: After a familiarization session, fourteen highly trained sprint athletes, 12 men (23.25 ± 7.17 years) and 2 women (23.0 ± 2.8 years) performed 2 experiments, each in a randomized order (crossover design). In one experiment, the time‐course of twitch contractile properties was evaluated with and without the previous CA at 2, min intervals to 10 min of recovery. In the second session, maximal voluntary knee extension was evaluated at the same recovery intervals, for control and experimental condition in random order. Results: Mixed‐model ANOVA with Bonferroni post‐hoc revealed significant differences between pre‐test and 2 min (p < 0.01, ES = 0.42) and 4 min (p < 0.01, ES = 0.20) for peak twitch torque of quadriceps femoris muscles confirming postactivation potentiation [PAP] at these times. Twitch rate of torque development (RTD) was significantly greater than pre‐test value only at 2 min (p < 0.01, ES = 0.58) after the CA. Twitch contraction time and ½ relaxation time were not significantly difference from pre‐test values after the CA (p > 0.05). No significant difference was observed for voluntary RTD following CA. Conclusion: The plyometric CA increased twitch peak torque and RTD consistent with PAP; however, there was no effect of CA on voluntary RTD of knee extension at any time after the plyometric CA. Even with PAP confirmed, we observed that the CA fails to improve isometric RTD of quadriceps femoris muscles.

Highlights

A plyometric CA significantly increased twitch peak torque (at 2 and 4 min) and twitch rate of torque development (at 2 min) of quadriceps femoris muscles, indicating postactivation potentiation (PAP).

No effect was observed for twitch contraction time and ½ relaxation time after the CA.

No improvement was observed on voluntary rate of torque development evaluated at the same time intervals.
High yield (⩾108/pulse) DD neutron generator based on a compact, transportable and low energy plasma focus device
Authors: Niranjan Ram , Srivastava R , Joycee J , Joshi K D
Published: April 2021

A pulsed DD neutron generator based on the plasma focus (PF) device has been developed. The PF device was assembled using a single energy storage capacitor (10 µF) and a triggerable spark gap switch in a compact geometry. The anode of the PF device was made of SS304 material with its tip modified using a high purity tungsten insert. Excluding the power supply, the size of the overall system was 0.6 × 0.6 × 1.0 m and the weight was less than 100 kg. A maximum DD neutron yield of (3.1 ± 0.2) × 108 neutrons/pulse and average DD neutron yield of (2.24 ± 0.16) × 108 neutrons/pulse (pulse duration = 35 ± 4 ns) into 4π sr were observed at a capacitor bank energy of 3.1 kJ (25 kV) and at 4.5 mbar D2 gas filling pressure. The experimentally observed average neutron yield was found to be around 30% more than the estimated yield obtained using scaling laws for neutrons (Y
n ≈ 1.7 × 10−10
I
0
3.3; I
0 is the peak discharge current in A). For a peak discharge current of 258 kA at 3.1 kJ, the neutron yield was estimated to be 1.23 × 108 neutrons/pulse. The higher neutron production was attributed to the efficient design of the PF device as well as to the low erosion of the anode tip because of the tungsten insert. Using the time-of-flight method, maximum neutron energy was calculated to be 3.91 ± 0.16 MeV in the radial direction at 4.5 mbar filling pressure. Numerical parametrization using the five-phase Lee model code was performed and found to be similar to PF devices developed across the world.
Tropical dry forest resilience and water use efficiency: an analysis of productivity under climate change
Authors: Stan Kayla D , Sanchez-Azofeifa Arturo , Duran Sandra M , Guzman Q J Antonio , Hesketh Michael , Laakso Kati , Portillo-Quintero Carlos , Rankine Cassidy , Doetterl Sebastian
Published: April 2021

Tropical dry forests (TDFs) worldwide have an environment-sensitive phenological signal, which easily marks their response to the changing climatic conditions, especially precipitation and temperature. Using TDF phenological characteristics as a proxy, this study aims to evaluate their current continental response to climate change across the Americas. Here, we show that TDFs are resilient to water stress and droughts by increasing their rain use efficiency (RUE) in drier years and recovering to average RUE in the year following the drought. Additionally, we find that TDF productivity trends over the past 18 years are spatially clustered, with sites in the northern hemisphere experiencing increased productivity, while equatorial regions have no change, and the southern hemisphere exhibiting decreased productivity. The results indicate that the TDF will be resilient under future climatic conditions, particularly if there are increasing drought conditions.
Warm-season net CO2 uptake outweighs cold-season emissions over Alaskan North Slope tundra under current and RCP8.5 climate
Authors: Tao Jing , Zhu Qing , Riley William J , Neumann Rebecca B
Published: April 2021

Arctic warming has increased vegetation growth and soil respiration during recent decades. The rate of Arctic warming will likely amplify over the 21st century. Previous studies have revealed that the most severe Arctic warming occurred during the cold season (September to May). The cold-season warming has posited significant CO2 emissions to the atmosphere via respiration, possibly offsetting warm-season (June to August) net CO2 uptake. However, prevailing Earth system land models poorly represent cold-season CO2 emissions, making estimates of Arctic tundra annual CO2 budgets highly uncertain. Here, we demonstrate that an improved version of the energy exascale Earth system model (E3SM) land model (ELMv1-ECA) captures the large amount of cold-season CO2 emissions over Alaskan Arctic tundra as reported by two independent, observationally-constrained datasets. We found that the recent seven-decades warming trend of cold-season soil temperature is three times that of the warm-season. The climate sensitivity of warm-season net CO2 uptake, however, is threefold higher than for the cold-season net CO2 loss, mainly due to stronger plant resilience than microbial resilience to hydroclimatic extremes. Consequently, the modeled warm-season net CO2 uptake has a larger positive trend (0.74 ± 0.14 gC m−2 yr−1) than that of cold-season CO2 emissions (0.64 ± 0.11 gC m−2 yr−1) from 1950 to 2017, supported by enhanced plant nutrient uptake and increased light- and water-use efficiency. With continued warming and elevated CO2 concentrations under the representative concentration pathway (RCP) 8.5 scenario, the increasing rate of warm-season net CO2 uptake is more than twice the rate of cold-season emissions (1.33 ± 0.32 gC m−2 yr−1 vs 0.50 ± 0.12 gC m−2 yr−1), making the modeled Alaskan Arctic tundra ecosystem a net CO2 sink by 2100. However, other geomorphological and ecological disturbances (e.g. abrupt permafrost thaw, thermokarst development, landscape-scale hydrological changes, wildfire, and insects) that are not considered here might alter our conclusion.
Exact densities of loops in O(1) dense loop model and of clusters in critical percolation on a cylinder
Authors: Povolotsky A M
Published: April 2021

We obtain exact densities of contractible and non-contractible loops in the O(1) model on a strip of the square lattice rolled into an infinite cylinder of finite even circumference L. They are also equal to the densities of critical percolation clusters on 45 degree rotated square lattice rolled into a cylinder, which do not or do wrap around the cylinder respectively. The results are presented as explicit rational functions of L taking rational values for any even L. Their asymptotic expansions in the large L limit have irrational coefficients reproducing the earlier results in the leading orders. The solution is based on a mapping to the six-vertex model and the use of technique of Baxter’s T–Q equation.
Rare extinction events in cyclic predator–prey games
Authors: Serrao Shannon R , Ritmeester Tim , Meyer-Ortmanns Hildegard
Published: April 2021

In the May–Leonard model of three cyclically competing species, we analyze the statistics of rare events in which all three species go extinct due to strong but rare fluctuations. These fluctuations are from the tails of the probability distribution of species concentrations. They render a coexistence of three populations unstable even if the coexistence is stable in the deterministic limit. We determine the mean time to extinction (MTE) by using a WKB-ansatz in the master equation that represents the stochastic description of this model. This way, the calculation is reduced to a problem of classical mechanics and amounts to solving a Hamilton–Jacobi equation with zero-energy Hamiltonian. We solve the corresponding Hamilton’s equations of motion in six-dimensional phase space numerically by using the Iterative Action Minimization Method. This allows to project on the optimal path to extinction, starting from a parameter choice where the three-species coexistence-fixed point undergoes a Hopf bifurcation and becomes stable. Specifically for our system of three species, extinction events can be triggered along various paths to extinction, differing in their intermediate steps. We compare our analytical predictions with results from Gillespie simulations for two-species extinctions, complemented by an analytical calculation of the MTE in which the remaining third species goes extinct. From Gillespie simulations we also analyze how the distributions of times to extinction (TE) change upon varying the bifurcation parameter. Our results shed some light on the sensitivity of the TE to system parameters. Even within the same model and the same dynamical regime, which allows a stable coexistence of species in the deterministic limit, the MTE depends on the distance from the bifurcation point in a way that contains the system size dependence in the exponent. It is challenging and worthwhile to quantify how rare the rare events of extinction are.
Macroscopic stability of cluster states under local transformations
Authors: Muñoz C , Gaeta M , Klimov A B
Published: April 2021

We prove that all macroscopic properties of the N-qubit cluster state are asymptotically invariant under local transformations in the limit N ≫ 1, and can be described by a distribution function similar to that of the completely mixed state.
The acceleration mechanism of shock wave induced by millisecond-nanosecond combined-pulse laser on silicon
Authors: LI Jingyi , ZHANG Wei , ZHOU Yu , YUAN Boshi , CAI Jixing , JIN Guangyong
Published: April 2021

The velocity variation law of shock wave induced by millisecond-nanosecond combined-pulse laser has been investigated experimentally. The pulse delay and laser energy are important experimental variables. The method of laser shadowgraphy is used in the experiment. Experimental results show that when the pulse delay is 2.4 ms, the ms and ns laser energy density is 301 J cm−2 and 12 J cm−2, respectively, the velocity of shock wave is 1.09 times faster than that induced by single ns pulse laser. It is inferred that the shock wave propagates in the plasma is faster than that in air. When the ms and ns laser energy density is 414.58 and 24 J cm−2, the velocity of shock wave shows rising trend with pulse delay in a range of 1.4 ms > Δt > 0.8 ms. It is indicated that with the increase of ns laser energy, the laser energy absorbed by laser-supported absorption wave increases. The mechanism of inverse bremsstrahlung absorption acts with target surface absorption simultaneously during the ns laser irradiation. Thus, the phenomenon of the double shock wave is induced. The numerical results of the phenomenon were accordance with experiment. The results of this research can provide a reference for the field of laser propulsion.
Experimental investigation of the electromagnetic effect and improvement of the plasma radial uniformity in a large-area, very-high frequency capacitive argon discharge
Authors: HAN Daoman , SU Zixuan , ZHAO Kai , LIU Yongxin , GAO Fei , WANG Younian
Published: April 2021

We performed an experimental investigation on the electromagnetic effect and the plasma radial uniformity in a larger-area, cylindrical capacitively coupled plasma reactor. By utilizing a floating hairpin probe, dependences of the plasma radial density on the driving frequency and the radio-frequency power over a wide pressure range of 5–40 Pa were presented. At a relatively low frequency (LF, e.g. 27 MHz), an evident peak generally appears near the electrode edge for all pressures investigated here due to the edge field effect, while at a very high frequency (VHF, e.g. 60 or 100 MHz), the plasma density shows a sharp peak at the discharge center at lower pressures, indicating a strong standing wave effect. As the RF power increases, the center-peak structure of plasma density becomes more evident. With increasing the pressure, the standing wave effect is gradually overwhelmed by the ‘stop band’ effect, resulting in a transition in the plasma density profile from a central peak to an edge peak. To improve the plasma radial uniformity, a LF source is introduced into the VHF plasma by balancing the standing wave effect with the edge effect. A much better plasma uniformity can be obtained if one chooses appropriate LF powers, pressures and other corresponding discharge parameters.
Hospitalisation without delirium is not associated with cognitive decline in a population-based sample of older people—results from a nested, longitudinal cohort study
Authors: Richardson Sarah J , Lawson Rachael , Davis Daniel H J , Stephan Blossom C M , Robinson Louise , Matthews Fiona E , Brayne Carol , Barnes Linda E , Taylor John-Paul , Parker Stuart G , Allan Louise M
Published: April 2021

Background

Acute hospitalisation and delirium have individually been shown to adversely affect trajectories of cognitive decline but have not previously been considered together. This work aimed to explore the impact on cognition of hospital admission with and without delirium, compared to a control group with no hospital admissions.

Methods

The Delirium and Cognitive Impact in Dementia (DECIDE) study was nested within the Cognitive Function and Ageing Study II (CFAS II)–Newcastle cohort. CFAS II participants completed two baseline interviews, including the Mini-Mental State Examination (MMSE). During 2016, surviving participants from CFAS II–Newcastle were recruited to DECIDE on admission to hospital. Participants were reviewed daily to determine delirium status.

During 2017, all DECIDE participants and age, sex and years of education matched controls without hospital admissions during 2016 were invited to repeat the CFAS II interview. Delirium was excluded in the control group using the Informant Assessment of Geriatric Delirium Scale (i-AGeD). Linear mixed effects modelling determined predictors of cognitive decline.

Results

During 2016, 82 of 205 (40%) DECIDE participants had at least one episode of delirium. At 1 year, 135 of 205 hospitalised participants completed an interview along with 100 controls. No controls experienced delirium (i-AGeD>4). Delirium was associated with a faster rate of cognitive decline compared to those without delirium (β = −2.2, P < 0.001), but number of hospital admissions was not (P = 0.447).

Conclusions

These results suggest that delirium during hospitalisation rather than hospitalisation per se is a risk factor for future cognitive decline, emphasising the need for dementia prevention studies that focus on delirium intervention.
Lung Cancer Mortality and Styrene Exposure in the Reinforced-Plastics Boatbuilding Industry: Evaluation of Healthy Worker Survivor Bias
Authors: Bertke Stephen J , Keil Alexander P , Daniels Robert D
Published: April 2021

The evidence for styrene’s being a human lung carcinogen has been inconclusive. Occupational cohorts within the reinforced-plastics industry are an ideal population in which to study this association because of their relatively high levels of exposure to styrene and lack of concomitant exposures to other known carcinogens. However, healthy worker survivor bias (HWSB), where healthier workers stay employed longer and thus have higher exposure potential, is a likely source of confounding bias for exposure-response associations, in part due to styrene’s acute effects. Through December 31, 2016, we studied a cohort of 5,163 boatbuilders exposed to styrene in Washington State who were employed between 1959 and 1978; prior regression analyses had demonstrated little evidence for an exposure-response relationship between styrene exposure and lung cancer mortality. Based on estimates of necessary components of HWSB, we found evidence for a potentially large HWSB. Using g-estimation of a structural nested model to account for HWSB, we estimated that 1 year of styrene exposure at more than 30 parts per million accelerated time to lung cancer death by 2.29 years (95% confidence interval: 1.53, 2.94). Our results suggest possibly strong HWSB in our small cohort and indicate that large, influential studies of styrene-exposed workers may suffer from similar biases, warranting a reassessment of the evidence of long-term health effects of styrene exposure.