bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Control System for Climbing Robot based on Multi-sensor
Authors: Xu Hong Bin , Xu Borun , Ding Jieyue
Published: August 2019

In this paper, the modular design idea and MVC design pattern are used to study a control system of a wall-climbing robot applied to detecting the surface of large-scale tanks. The design mainly has two parts:hardware system and software system. The hardware system consists of power modules, sensor modules, control modules, and communication modules. The software system is composed of the robot control software, the robot remote control App based on Android devices, and the upper computer application program which can run in both Windows system and Linux system. Finally, the feasibility and robustness of the system are verified by experiments.
Design of a single-stage Flyback LED Constant current Driving Power Supply
Authors: Xu Yingchao , Lin Jiatao , Xie Xiaoqi , Cai Chuyu
Published: August 2019

In order to solve the problems of high cost and low efficiency of current LED driving power supply, a single-stage flyback LED constant current driving circuit is designed. The power supply adoptes OZ8027 as the main control chip in the critical conduction mode, which uses the peak current control method. A wide range of input voltage of 85~265V is designed, the output current is 200mA, and the actual output power target value is 13W. It is suitable for an AC input type for flyback constant current driving circuit whose light source board owns LEDs for 2-series and 5-parallel. This research describes the working principle of a single-stage flyback LED constant current drive circuit. The detailed design and analysis of the various components of the driving power supply circuit. The test shows that the circuit works normally, and the output current can be obtained after testing. The current is stable at 200mA, output power is 12.7W, output ripple ratio is 1.65%, and the conversion efficiency is as high as 92.33%. The experimental results show that the designed LED driving power supply is stable and reliable, low cost, high efficiency and meets the design standards of LED driving power supply.
Physical length scales of wind-blown snow redistribution and accumulation on relatively smooth Arctic first-year sea ice
Authors: Moon Woosok , Nandan Vishnu , Scharien Randall K , Wilkinson Jeremy , Yackel John J , Barrett Andrew , Lawrence Isobel , Segal Rebecca A , Stroeve Julienne , Mahmud Mallik , Duke Patrick J , Else Brent
Published: August 2019

Snow thickness measurements over relatively smooth Arctic first-year sea ice, obtained near Cambridge Bay in the Canadian Arctic (2014, 2016 and 2017) and near Elson Lagoon in the Alaskan Arctic (2003 and 2006), are analyzed to quantify physical length-scales and their relevant scaling behaviors. We use the multi-fractal temporally weighted detrended fluctuation analysis method to detect two major physical length-scales from the two independent study locations. Our results suggest that physical processes underlying the formation of snow dunes are consistent and that the wind is the main process shaping the snow thickness variability and redistribution. One scale, around 10 m, appears to be related to the formation of the snow ‘dunes’, while the other scale, between 30 and 100 m, is likely associated with the various interactions of the snow dunes such as merging, calving and lateral linking. Results imply that snow on level sea ice shows self-organized characteristics.
2018 summer extreme temperatures in South Korea and their intensification under 3 °C global warming
Authors: Im Eun-Soon , Thanh Nguyen-Xuan , Kim Young-Hyun , Ahn Joong-Bae
Published: August 2019

With the acceleration in global warming, extreme hot temperatures have emerged as one of the most prominent risks. In this study, we characterize the unprecedented extreme temperatures that occurred in Korea in summer 2018, and attempt to explain how this locally observed extreme event can be interpreted in the context of 2 °C and 3 °C global warming above the pre-industrial level. To better resolve geographically diverse climate features and enhance confidence in future changes, three global projections are dynamically downscaled using three regional climate models that are customized over Korea and the systematic biases are statistically corrected using quantile mapping. In July and August 2018, abnormally high maximum temperatures (Tmax) were observed over the entire territory of South Korea. Beyond the increase of mean value, Tmax at individual stations departed significantly from the typical Gaussian distribution of climatological Tmax due to the dramatic changes in the extent and shape of upper tails. The distinct behaviors of Tmax that appeared in 2018 largely represent the statistical analog of the distribution pattern expected under 3 °C global warming based on fine-scale climate projections. This implies that statistically extremely rare events like that of summer 2018 will become increasingly normal if global average temperature is allowed to increase by 3 °C. More importantly, the extreme heat stress measured by the wet-bulb globe temperature is projected to intensify the risks to a level never before seen in contemporary climate. This study is timely and relevant to the need to identify how the globally aggregated warming target temperature can be disaggregated into regional impacts.
Niche theory within video platform competition: traditional vs modern
Authors: Sukwadi R , Lasiman S C , Inderawati M M W , Suprata F
Published: August 2019

Rapid proliferation of the usage of internet-based modern television (IPTV and OTT) in Indonesia as well as limited and similar resources threatens the existence of old/traditional video platforms (satellite television and cable television). Adapted from ecological studies, niche theory is used to measure the level of dynamic competition among media. Through three concepts of measurement of niche theory, niche breadth, nice overlap, and competitive superiority, the competition relationship between these four video platforms can be analyzed. The questionnaire was spread out online and offline to 502 respondents of each platform. Focus group discussions were conducted in two groups with 6 respondents each group. The results of this study were also analyzed based on the media life cycle. The conclusions of this study are: 1) OTT is a generalist platform, IPTV and cable television tend to be generalist, and satellite television is classified as a specialist; 2) The highest competition occurs between cable television and IPTV; 3) OTT is the most competitive platform whereas satellite television is the least competitive; 4) Satellite television is in defensive resistance life cycle, cable television in defensive resistance and adaptation cycles, IPTV in growth cycle, and OTT in maturation cycle.
Analysis of chemical elements of the rocks on the coastal areas in the Eastern Bolaang-Mongondow District, North Sulawesi Indonesia
Authors: Angmalisang P A , Manu L , Sangian H F
Published: August 2019

The chemical elements making up the rocks located on the coastal areas in the Eastern Bolaang Mongondow were successfully mapped and investigated by employing the XRF method. The rocks collected from the Central Buyat, South Buyat, Motongkat and Jiko coastal areas of the sub-districts were milled until the size was close to 120 mesh. The samples were characterized and measured to obtain the chemical elements deposited inside the rocks. It was found that the elements which make up the rocks are relatively different depending on the coastal locations. The silicon (Si) was the highest percentage of all elements found and followed by iron (Fe), calcium (Ca) and aluminum (Al). The composition of Si deposited in the rocks from Buyat coastal area was of 42.4% which the biggest percentage compared the rest of the samples. The Iron (Fe) element had a chemical composition recorded at 28.9% that was the highest figure in which rocks were obtained from Jiko coast. The aluminum (Al) composition was relatively similar for all samples collected from that location and observed at 10%.
Trophic status of Limboto lake in Gorontalo Province
Authors: Noor S Y
Published: August 2019

Limboto Lake were on the worried condition now. It happened because of the process depreciation and sedimentation which caused by sedimentation and waste ground that threaten the existence of ecosystem in the future. The purpose of the research is to determine trophic status of Limboto Lake in Gorontalo Province. Measurements of several water quality parameters were carried out insitu at 8 (eight) stations conducted by sampling and laboratory analysis of several parameters of water quality carried out at the Manado Research and Standardization Reasearch Centre. To determine the trophic status of Limboto Lake waters calculated using the Trophic State Index (TSI) of Carlson. The results showed that the average value Trophic State Index (TSI) of Limboto Lake range from 50.3071 – 61.9297. This shows that the trophic status of Limboto Lake waters is classified as eutrophic.
Biodegradable fixator for sternum closure after median sternotomy
Authors: Bebnev I , Kashapov R N , Kashapov N F , Kashapov L N
Published: August 2019

Annotation

This article discusses the solutions to manufacture fixator for the osteosynthesis of the sternum from biocompatible and biodegradable material to prevent reopening.
Structure formation in materials based on Fe-C-Si and Fe-C-Al systems (cast irons) prepared from dispersed mechanical engineering waste
Authors: Bikulov R
Published: August 2019

The paper presents fn alternative technological process for producing compact forms of graphite inclusions in the materials based on the Fe-C-Si and Fe-C-Al (cast iron) systems. It differs from traditional methods of obtaining compact forms of graphite inclusions, which consist in modifying the molten iron or annealing white iron: the proposed technological process is based on a synergistic complex of foundry-metallurgical factors affecting the cast iron in the stages of its melt preparation and crystallization in a mold.
Research of a laser welding of thin-shit construction steels by continuous laser radiation
Authors: Gabdrakhmanov Az T , Galiakbarov AT , Shafigullin L N , Gabdrakhmanova T F
Published: August 2019

The results of the laser welding by continuous radiation of thin-sheet low-carbon steels on the example of steel 08U presented in this paper. Metallographic studies of the laser weld were conducted. Tensile tests were carried out as a result of which it was determined that the nature of the fracture is adhesive, and after cohesive failure of the specimens, it is show the high quality of the welded joints at the beginning of the weld.
Effects of moisture content on thermal conductivity of thermal insulation materials
Authors: Gusyachkin A M , Sabitov L S , Khakimova A M , Hayrullin A R
Published: August 2019

Insulation materials play an important role in district heating pipeline networks. Thermal losses in pipe insulation systems depend on the thermal conductivity of insulation materials. The thermal conductivity of the insulation materials is influenced by the temperature and moisture content. In this paper the effect of moisture content on the thermal conductivity of rock wool produced by different manufacturers was considered. Experimental studies were performed using the standard guarded hot plate (GHP) method. Higher thermal conductivity is always associated with higher moisture content for all investigated samples.
Research of efficiency of work of heat-mechanical equipment by the thermography method
Authors: Karataev O R , Karataeva E S
Published: August 2019

The paper deals with the solution of problems to assess the technical condition of thermal mechanical equipment, on the example of boilers by thermography. As a result of the study of the brickwork of the steam hot-water boiler, thermal imaging images were obtained, from which it can be concluded that the brickwork of the boiler does not perform its direct functions, the insulation is outdated. Thus, constant monitoring allows making current repair of machinery, reducing wear and heating loss to maintain efficiency at the project level.
New methodological approach to the development of the theory of electric traction of urban electric transport
Authors: Kashapov N F , Sabitov L S , Auhadeev A E , Litvienko R S , Pavlov P P
Published: August 2019

The article presents the scientific hypothesis that the modes of operation of electric traction equipment as part of an automated electric drive of the rolling stock of urban electric transport are formed under the influence of a complexly organized technological process of electric traction and are the topological basis of its structure. The aim of the study was to study the process of converting electrical energy into a targeted mechanical movement of rolling stock in the implementation of all technological conditions of the production and technical system of urban electric transport. The theoretical study was carried out on the basis of a methodological analysis of the theory of electrical equipment, the theory of automatic control and an automated electric drive, the theory of electric traction, the theory of motion construction, a systematic approach and a synergistic natural science paradigm. The main result is a formulated scientific concept, which allows to present the process of electric traction as a system consisting of five levels that are in hierarchical relations and solve each specific problem of building the movement of electric transport. The obtained theoretical system will allow developing the general theory of electric traction of urban electric transport by improving the methodological principles of the formation of operating modes of electric traction equipment when implementing the transportation process technology in the production and technical system of urban electric transport.
Modern problems of digitalization of agricultural production
Authors: Kashapov N F , Nafikov M M , Gazetdinov M KH , Gazetdinov SH M , Nigmatzyanov A R
Published: August 2019

At the present stage, the most promising form of digitalization of production and management in agriculture is the formation of an integrated digital production complex as an organic merger of technical means of digitalization of production on the basis of precision farming, artificial intelligence management, as well as information and analytical management system. The availability of such a powerful tool as an information and analytical system as part of an integrated digital production complex in combination with the most digitized production processes can simultaneously meet modern requirements for increasing productivity and reducing costs for the production of agricultural products and food, and a sharp increase in the quality of products. It is argued that the functioning of information and analytical systems in some large agricultural formations of the Republic of Tatarstan has provided a qualitative leap in the development of methods and means of digitalization of production and management. It became possible to integrate automated controls up to the level of agro-technological management without a gap between the organizational, economic and agro-technological levels. The main problems to be solved in the development of IAS IDPC are considered. Expert systems, which have been developing rapidly in recent years, seem to be a promising tool for solving such problems.
Justification of requirements to quality and accuracy of blankfor precision stamping
Authors: Shibakov V G , Pankratov D L , Nizamov R S , Nizamova L M , Khairullin R A
Published: August 2019

The dispersion of blank masses depending on the accuracy class of the initial metal rolling is estimated. The influence of the method of the initial blank segments on the stamping process is described.
Characteristic features of the cooling capacity of aqueous polymer solutions
Authors: Shveyova T V , Muhametzyanova G F , Astashchenko V I , Zapadnova N N , Zapadnova E A
Published: August 2019

For the study of quenching medium a special sample is developed that provides high reproducibility of thermal processes occurring on the surface of the cooled product. The results of the cooling method of aqueous solutions with different polymer content are given. The application of thermogravimetric analysis for the study of physical and chemical processes occurring during heating of a synthetic quenching medium is considered. The temperature intervals of endo-exothermic reactions as a result of oxidation of the polymer component of the solution are shown. The reasons for the formation of two extrema on the cooling capacity curve of aqueous polymer solutions are indicated.
The criterion of non-stationary cyclic fatigue of bodies, taking into account the presence of an incubation period of destruction
Authors: Talibly Latif H.
Published: August 2019

A functional of nonstationary cyclic fatigue of bodies was constructed under the assumption that the destruction process occurs in time after the deformation process.

Damage conditions are derived, which determines the number of non-stationary loading cycles, in which damage and cyclic fatigue occurs in the body, which makes it possible to find the nonstationary number of loading cycles before failure.
The prospects of modern quality management approaches integration (on the example of the Republic of Tatarstan)
Authors: Vorontsov D P , Pirogova A S , Shikhalev A M , Khamidullina G R , Kashapov N F , Khananova A F , Rozhko O N
Published: August 2019

In the research basing on the quality management modern approaches and the practice of the Republic of Tatarstan leading industrial enterprises are estimated the possibilities of energy management systems improving (with intensive introduction of modern industrial equipment) through the integration of the quality management system. In our study is made an analysis of present energy management systems functioning indicators and demonstrated the further need for these two systems integration in the modern management.
About Modeling Kinematic Parameters of Deposition from Composite Electrochemical Coatings for Restoration of Details for Agricultural Machines
Authors: Zhachkin S Yu , Sharifullin S N , Penkov N A , Zavrazhnov A A
Published: August 2019

Theoretical aspects of process of drawing of composite galvanic coverings on the basis of a chromic matrix on current-carrying surfaces are considered by method of galvanic contact plating (GCP). The analytical dependences connecting parameters of physic mechanical characteristics of a covering with technological modes of sedimentation of coverings and design features of the equipment, used in process are resulted.
Bond the Gap between Academic and Industry Requirements for Undergraduate Civil Engineering Students in Iraq
Authors: Naji Zaher Mohammed , Dakhil Ammar , Jasim Samer Al
Published: August 2019

In the last twenty years, civil engineering industry has been improved significantly due to the expanded use of technology and innovations in project management. This progress represented as a challenge to universities to provide competence engineers with the right capabilities to be fit in the new job requirements and able to lead this industry to the new era. As this problem considered a global issue, it has a particular situation in Iraq. This resulted from the sharp change in the Iraqi construction industry after recent political change in 2003. This study aims to investigate the current industry expectation from graduated civil engineers and compare it with actual competences that engineers learned from their study in Iraqi universities. This research implements both a qualitative and quantitative approach to collect valuable and reliable data. This has been achieved by sending an online questionnaire to senior engineers working for both public and private organizations. In addition, another set of questions send to students to evaluate their knowledge to identify the gap. This study identified a considerable gap between current civil engineering education and industry expectation, which mainly resulted in project management skills. This gap needs to be addressed in the near future to make sure that Iraqi civil engineers maintain their chances to get hired from foreign companies and be able to lead the Iraqi construction industry to the global market.
Factors effecting on the compressive and tensile strength of reactive powder concrete made with local materials
Authors: Chkheiwer A H , Kadim J A
Published: August 2019

Ultra High Performance Concrete (UHPC) represent as one of the most concrete progressive development so that it can be improved the strength, durability, reliability, and resilience of the concrete structures. The availability of local materials play the main role in the major step in making the economic mix jobs by saving their materials and effort and decrease the concrete cost. So in this paper, the parameters including the curing regimes, of sand gradation, binder type, and content, and steel fiber content were investigated to show their effect on concrete’s compressive strength. The obtained results showed that the curing regime that consists of 5 days (2 days at 60°, 3 days at 80°) given the highest strength than other curing regimes. Finer sand, Silica Fume, steel fibers cause a considerable increasing in compression strength. Various relationship were obtained illustrating the effect of studied parameters with concrete strength.
The Evaluation of Khorasan Razavi Range for the construction of wind power plants through multi-criteria decision making in GIS environment
Authors: Alhameedah A Sh , Shad R , Ghaemi M
Published: August 2019

The purpose of this research was to determine the suitable location of wind power plants in Khorasan Razavi province according to the climate criteria and conditions (wind speed, prevailing wind speed, pressure and temperature), geography (elevation, slope), socioeconomic factors (distance, distance from the cities and distance from the villages), environmental factors (distance from protected areas, land use and distance from the river) and geology (distance from faults). The process has been carried out in the geographical information system environment using the analytical hierarchical process. Based on the role and effect of these factors, a map of the Effective Factors was prepared in ArcGIS10.6 environments. The weight of the criteria was determined by the Analytical Hierarchy Process Analysis (AHP) method in the EC2000 software environment. The ArcGIS10.6 software was used for spatial modelling, analysis and overlaying the different layers. The final map of suitable wind power plants was carried out in four different classes (very suitable, suitable, somewhat suitable and unsuitable). The results showed that 10.37% (1239871 ha) of the area was identified as very suitable for construction, including areas in the northwest of the province (around Sabzevar) and relatively slightly in the southeast (around Taibad) and eastern area (around Sarakhs). The results also showed that the GIS, as a decision support system in building a power plant, can be used to prepare data and prioritize experts’ models and opinions regarding various factors in choosing the appropriate location for an effective wind power plant.
The Role of Cooling Degree Days on determining the insulation of building Envelop in a hot climate (Iraqi cities as an example)
Authors: Hassan Susan Abed
Published: August 2019

Last decades witnessed rise in global average temperature for cities, consequently with the problem of rising needs for energy results from the growth of populations in cities. Recent studies concentrated on degree days method to calculate energy consumption for buildings, the main problem of this research is the role of cooling degree days on determining insulation of buildings envelope in a hot climate and for Iraqi cities as an example. The research aims to determine insulation of buildings envelope according to cooling degree days which reduce energy consumption; the results showed that there were differences in cooling degree days for main Iraqis cities, and there was an effect of buildings envelope insulation on cooling energy lost, the insulation for walls reduced consumption energy by 70-80%. Also, the insulation for ceiling reduced consumption energy by 65%, as compared to the same building materials without insulation.
Effect of Nano-Silica and Micro Steel Fiber on Compressive Strength Development of Fly Ash Geopolymer Paste Cured Under Ambient Temperature
Authors: Hadi Noor S. , Salman Wissam D. , Safie Mahdi Oleiwi S
Published: August 2019

This paper present the development on compressive strength of fly ash geopolymer paste under effectiveness of nano-silica and micro steel fiber. Twelve geopolymer paste mixes under two series, the first series with replacement (0% to 1.4%) by increment (0.2%) of binder by nano-silica and using the optimum concentration of nano silica in second series with addition (0.5% to 2%) by increment (0.5%) of micro steel fiber. The mixes were using fly ash as binder with Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions as the alkali activators. (Na2SiO3 to NaOH) ratio was (2.0) with molarity of sodium hydroxide (10 M), and the specimens cured under room temperature (35 ± 2)°c. Results Show that the compressive strength of fly ash geopolymer paste can be improved as high as 76.5MPa at 28 days by add 0.8% nano silica and 1% micro steel fiber which were the optimum proportion that caused noteworthy improvement of compressive strength.
Investigating the influence of cement replacement by high volume of GGBS and PFA on the mechanical performance of cement mortar
Authors: Shubbar Ali Abdulhussein , Al-Shaer Ali , AlKizwini Rasha Salah , Hashim Khalid , Hawesah Hayder Al , Sadique Monower
Published: August 2019

The technique of replacing the cement with other alternative materials focus on the production of materials with similar performance and reduced environmental impacts relative to traditional cement. The main aim of this study is to investigate the effect of replacing the cement content with high volume of GGBS and PFA on the mechanical performance of cement mortar. Three mixtures were prepared with different percentages of GGBS and PFA (40%, 60% and 80%) as replacement of cement along with other mixture that made with 100% cement as a control mixture. In order to evaluate the performance of the cement mortars, compressive strength test after 7, 14 and 28 days of curing was used. The results indicated that after 7 days of curing, the increase of GGBS and PFA contents caused a reduction in the compressive strength in comparison with the control mixture. After 28 days of curing, the results indicated that the mixture incorporated 80% GGBS and PFA has higher compressive strength relative to the control mixture. Such findings will significantly contribute in reducing the cost of the produced mortar by reducing the amount of used cement and this consequently reduce the cement demands/manufacturing. Less production of cement will reduce the CO2 emissions of the cement industry.
Solid Waste Situation in Thi-Qar Governorate
Authors: Ethaib Saleem
Published: August 2019

This study aims to provide an overview of the current status of solid waste in Thi-Qar governorate by a case study of five cities in this governorate. The five cities are namely: Al-Nassriya, Al-Shatra, Al-Rifai, Suk Al-Shoyokh, and Al-Chibayish. In general, the results revealed that the average generation rate of domestic solid waste was 0.85 Kg/capita/day in the study area. The organic waste was found the major components of municipal waste and it exceeded 60% of waste composition. All dumping sites in the aforementioned cities are uncontrolled dumpsite, their design not suitable, and do not work according to proper operating standards. There are no landfills or dumping sites specified for disposal the non-municipal waste. The investigations showed the presence of potential health risks and negative environmental aspects of solid waste handling in Thi-Qar governorate due to improper handling of collection, transfer, and disposal of solid waste. Thus, developing a master plan for integrated solid waste management is prerequisite to overcome the difficulties solid waste management sector in Thi-Qar governorate.
Evaluation Al-Safeena and Sayed Jawda Intersections in Kerbala City
Authors: Al-Murshidy Huda M. , Ewadh Hussein A. , Almuhanna Raid R. A.
Published: August 2019

Increase of traffic volumes at intersections is one of the significant reasons that cause congestion. The current study aims to analyze, assess and improve traffic performance of (Al-Safeena roundabout) and (Sayed Jawda intersection) in Kerbala city. In order to implement these goals, data of the traffic volume and geometric layout for (Al-Safeena roundabout) and (Sayed Jawda intersection) are manually collected. To achieve the traffic analysis process, (SIDRA version 7) traffic program was used. Al-Safeena intersection improved by adding a new lane for each approach, this reduce the delay times, fuel consumption, and stops. This process will reduce ratio of volume to capacity (v/c) to value 0.7 and the delay rate value to 15.3 sec and LOS to C. On other hand, traffic operation at Sayed Jawda intersection is relatively enhanced by dividing the width of approach to four lanes, however, level of service is not upgraded satisfactorily. Change Sayed Jawda intersection to roundabout reduces the value of v/c to 0.8, and the value of average delay to 24 sec and LOS C.
Air-entrainment as an alternative to polypropylene fibers and its effect on the compressive strength of concrete at high temperatures
Authors: Holan J , Novák J , Štefan R
Published: August 2019

Although much research has been done in the area of the fire response of concrete in the past decades, only few studies are focused on the mechanical properties of air-entrained concrete at high temperatures. This paper presents preliminary results of an experimental investigation focused on the effect of air-entrainment on the compressive strength of concrete at various high temperatures. Within the scope of this work, heat treatments and compression tests have been performed on reference and air-entrained concrete specimens. The results obtained from the experiments have been analysed and show that the air entrainment seems to have an adverse effect on the compressive strength of the concrete at high temperatures when exposed for a prolonged period of time.
Methods of lighting of concrete structures for high-speed camera measurement
Authors: Trtík T , Chylík R , Fládr J , Štoller J , Broukalová I
Published: August 2019

In extensive research, damage to concrete panels by explosion is investigated. For detailed monitoring of particular phases of explosion, exploitation of a high-speed camera is intended. The paper presents testing of possibilities of lighting of the scene at detonation with explosive agents. Four alternatives of agents were tested – three varying amounts of aluminium powder and argon. Paper presents results of the tests – intensity of lighting for tested variants, delay between ignition of lighting agent and the main detonation, and evaluates convenience of tested explosive agents for illuminating of the scene captured by high-speed camera.
Chebotarev density theorem in short intervals for extensions of 𝔽_{𝕢}(𝕋)
Authors: Bary-Soroker Lior , Gorodetsky Ofir , Karidi Taelin , Sawin Will
Published: August 2019

An old open problem in number theory is whether the Chebotarev density theorem holds in short intervals. More precisely, given a Galois extension

E
E

of

Q

\mathbb {Q}

with Galois group

G
G

, a conjugacy class

C
C

in

G
G

, and a

1
≥
ε
>
0

1\geq \varepsilon >0

, one wants to compute the asymptotic of the number of primes

x
≤
p
≤
x
+

x

ε

x\leq p\leq x+x^{\varepsilon }

with Frobenius conjugacy class in

E
E

equal to

C
C

. The level of difficulty grows as

ε
\varepsilon

becomes smaller. Assuming the Generalized Riemann Hypothesis, one can merely reach the regime

1
≥
ε
>
1

/

2

1\geq \varepsilon >1/2

. We establish a function field analogue of the Chebotarev theorem in short intervals for any

ε
>
0

\varepsilon >0

. Our result is valid in the limit when the size of the finite field tends to

∞
\infty

and when the extension is tamely ramified at infinity. The methods are based on a higher dimensional explicit Chebotarev theorem and applied in a much more general setting of arithmetic functions, which we name

G
G

-factorization arithmetic functions.
Potentially serious alcohol–medication interactions and falls in community-dwelling older adults: a prospective cohort study
Authors: Holton Alice , Boland Fiona , Gallagher Paul , Fahey Tom , Moriarty Frank , Kenny Rose Anne , Cousins Gráinne
Published: August 2019

Objective

To investigate the association between potentially serious alcohol–medication interactions (POSAMINO criteria), hypothesised to increase the risk of falls in older adults, and falls in community-dwelling older adults at two and 4 years follow-up.

Design

A prospective cohort study.

Setting

The Irish Longitudinal Study on Ageing.

Subjects

A total of 1,457 community-dwelling older adults aged ≥65 years, with a complete alcohol and regular medication data to allow for the application of the POSAMINO criteria.

Outcomes

Self-reported falls at 2 and 4 years follow-up, any falls (yes/no), injurious falls (yes/no) and number of falls (count variable).

Results

The number of participants who reported falling since their baseline interview at 2 and 4 years were 357 (24%) and 608 (41.8%), respectively; 145 (10%) reported an injurious fall at 2 years and 268 (18%) at 4 years. Median (IQR) number of falls was 1 (1–2) at 2 years and 2 (1–3) at 4 years. Exposure to CNS POSAMINO criteria, hypothesised to increase the risk of falls due primarily to increased sedation, was associated with a significantly increased risk for falling (adjusted relative risk (RR) 1.50, 95% confidence interval (CI) 1.21–1.88) and for injurious falls (adjusted RR 1.62, 95% CI: 1.03–2.55) at 4 years. These equate to an absolute risk of 19% for falling (95% CI: 5–33%) and 8% for injurious falls (95% CI, 4–20%) at 4 years.

Conclusions

Assessment and management strategies to prevent falls in community-dwelling older adults should consider patients’ alcohol consumption alongside their assessment of patient medications, particularly among those receiving CNS agents.
Exposure to Welding Fumes, Hexavalent Chromium, or Nickel and Risk of Lung Cancer
Authors: Pesch Beate , Kendzia Benjamin , Pohlabeln Hermann , Ahrens Wolfgang , Wichmann Heinz-Erich , Siemiatycki Jack , Taeger Dirk , Zschiesche Wolfgang , Behrens Thomas , Jöckel Karl-Heinz , Brüning Thomas
Published: August 2019

To investigate the risk of lung cancer after exposure to welding fumes, hexavalent chromium (Cr(VI)), and nickel, we analyzed 3,418 lung cancer cases and 3,488 controls among men from 2 German case-control studies (1988–1996). We developed a welding-process exposure matrix from measurements of these agents, and this was linked with welding histories from a job-specific questionnaire to calculate cumulative exposure variables. Logistic regression models were fitted to estimate odds ratios with confidence intervals conditional on study, and they adjusted for age, smoking, and working in other at-risk occupations. Additionally, we mutually adjusted for the other exposure variables under study. Overall, 800 cases and 645 controls ever worked as regular or occasional welders. Odds ratios for lung cancer with high exposure were 1.55 (95% confidence interval (CI): 1.17, 2.05; median, 1.8 mg/m3 × years) for welding fumes, 1.85 (95% CI: 1.35, 2.54; median, 1.4 μg/m3 × years) for Cr(VI), and 1.60 (95% CI: 1.21, 2.12; median, 9 μg/m3 × years) for nickel. Risk estimates increased with increasing cumulative exposure to welding fumes and with increasing exposure duration for Cr(VI) and nickel. Our results showed that welding fumes, Cr(VI), and nickel might contribute independently to the excess lung cancer risk associated with welding. However, quantitative exposure assessment remains challenging.
Computational identification of mutator-derived lncRNA signatures of genome instability for improving the clinical outcome of cancers: a case study in breast cancer
Authors: Bao Siqi , Zhao Hengqiang , Yuan Jian , Fan Dandan , Zhang Zicheng , Su Jianzhong , Zhou Meng
Published: August 2019

Emerging evidence revealed the critical roles of long non-coding RNAs (lncRNAs) in maintaining genomic instability. However, identification of genome instability-associated lncRNAs and their clinical significance in cancers remain largely unexplored. Here, we developed a mutator hypothesis-derived computational frame combining lncRNA expression profiles and somatic mutation profiles in a tumor genome and identified 128 novel genomic instability-associated lncRNAs in breast cancer as a case study. We then identified a genome instability-derived two lncRNA-based gene signature (GILncSig) that stratified patients into high- and low-risk groups with significantly different outcome and was further validated in multiple independent patient cohorts. Furthermore, the GILncSig correlated with genomic mutation rate in both ovarian cancer and breast cancer, indicating its potential as a measurement of the degree of genome instability. The GILncSig was able to divide TP53 wide-type patients into two risk groups, with the low-risk group showing significantly improved outcome and the high-risk group showing no significant difference compared with those with TP53 mutation. In summary, this study provided a critical approach and resource for further studies examining the role of lncRNAs in genome instability and introduced a potential new avenue for identifying genomic instability-associated cancer biomarkers.
Marsupial versus placental: assessing the evolutionary changes in the scapula of didelphids and sigmodontines
Authors: Bubadué Jamile M , Hendges Carla D , Cherem Jorge J , Cerezer Felipe O , Falconí Tania P , Graipel Maurício E , Cáceres Nilton C
Published: August 2019

It is not a new concept that marsupials and placentals are distant and distinct clades among mammals. In South America, these animals coexist, occupy similar niches and, in some cases, are similar in appearance. This is especially true with respect to the locomotor categories of smaller rodents belonging to the family Cricetidae or, more specifically, the subfamily Sigmodontinae, compared with the marsupials of the Didelphidae family. In this study, we have investigated both the similarities and the differences between the two clades by examining locomotion-dependent adaptation, a crucial survival mechanism that has affected the morphology of both clades. We applied geometric morphometrics to quantify the shape of the scapula, which is a very adaptable structure. We found similar morphological adaptations between the clades, especially with respect to adaptation to life in trees. Moreover, Didelphidae are influenced by phylogenetic history to a greater extent than Sigmodontinae with regard to variation of scapula shape and allometry. These differences can be explained by the greater degree of body size variation that exists within the Didelphidae. Didelphidae have an ancient evolutionary history in South America compared with the Sigmodontinae, which have undergone a very successful and rapid diversification more recently.
ARHGAP24 inhibits cell proliferation and cell cycle progression and induces apoptosis of lung cancer via a STAT6-WWP2-p27 axis
Authors: Wang Lei , Shen Saie , Xiao Haibo , Ding Fangbao , Wang Mingsong , Li Guoqing , Hu Fengqing
Published: August 2019

Rho GTPase-activating proteins (RhoGAPs) have been reported to be of great importance in the initiation and development of many different cancers. However, their biological roles and regulatory mechanisms in lung cancer development and progression are poorly defined. Real-time PCR or western blotting analysis was used to detect Rho GTPase-activating protein 24 (ARHGAP24), WWP2, p27, p-STAT6 and STAT6 expression levels as well as the activity of RhoA and Rac1 in lung cancer. Cell proliferation, apoptosis and cell cycle were measured by CCK-8 and flow cytometry analysis. Tumor growth of lung cancer cells was measured using a nude mouse xenograft experiment model in vivo. The correlation between WWP2 and p27 was measured by co-immunoprecipitation and ubiquitination analysis. We found that ARHGAP24 expression was lower in lung cancer tissues collected from the The Cancer Genome Atlas and independent hospital database. Overexpression of ARHGAP24 significantly suppressed cell proliferation and the activity of RhoA and Rac1, induced cell apoptosis and arrested cell cycle at the G0–G1 phase. ARHGAP24 overexpression also inhibited tumor growth in nude mice, whereas knockdown of ARHGAP24 significantly promoted cell proliferation and WWP2 expression and inhibited cell cycle arrest at G1 phase through activating STAT6 signaling. ARHGAP24 overexpression inhibited WWP2 overexpression-induced cell proliferation, cell cycle progression and the decreased p27 expression. Moreover, WWP2 was found interacted with p27, and WWP2 overexpression promoted the ubiquitination of p27. In conclusion, our findings suggest that ARHGAP24 inhibits cell proliferation and cell cycle progression and induces cell apoptosis of lung cancer via a STAT6-WWP2-p27 axis.
Extensive Connectivity Between the Medial Pulvinar and the Cortex Revealed in the Marmoset Monkey
Authors: Homman-Ludiye Jihane , Mundinano Inaki Carril , Kwan William C , Bourne James A
Published: August 2019

The medial pulvinar (PM) is a multimodal associative thalamic nucleus, recently evolved in primates. PM participates in integrative and modulatory functions, including directed attention, and consistently exhibits alterations in disorders such as schizophrenia and autism. Despite essential cognitive functions, the cortical inputs to the PM have not been systematically investigated. To date, less than 20 cortices have been demonstrated to project to PM. The goal of this study was to establish a comprehensive map of the cortical afferents to PM in the marmoset monkey. Using a magnetic resonance imaging-guided injection approach, we reveal 62 discrete cortices projecting to the adult marmoset PM. We confirmed previously reported connections and identified further projections from discrete cortices across the temporal, parietal, retrosplenial-cingulate, prefrontal, and orbital lobes. These regions encompass areas recipient of PM efferents, demonstrating the reciprocity of the PM-cortical connectivity. Moreover, our results indicate that PM neurones projecting to distinct cortices are intermingled and form multimodal cell clusters. This microunit organization, believed to facilitate cross-modal integration, contrasts with the large functional subdivisions usually observed in thalamic nuclei. Altogether, we provide the first comprehensive map of PM cortical afferents, an essential stepping stone in expanding our knowledge of PM and its function.
VGluT1 Deficiency Impairs Visual Attention and Reduces the Dynamic Range of Short-Term Plasticity at Corticothalamic Synapses
Authors: Lindström Sarah H , Sundberg Sofie C , Larsson Max , Andersson Fredrik K , Broman Jonas , Granseth Björn
Published: August 2019

The most common excitatory neurotransmitter in the central nervous system, glutamate, is loaded into synaptic vesicles by vesicular glutamate transporters (VGluTs). The primary isoforms, VGluT1 and 2, are expressed in complementary patterns throughout the brain and correlate with short-term synaptic plasticity. VGluT1 deficiency is observed in certain neurological disorders, and hemizygous (VGluT1+/−) mice display increased anxiety and depression, altered sensorimotor gating, and impairments in learning and memory. The synaptic mechanisms underlying these behavioral deficits are unknown. Here, we show that VGluT1+/− mice had decreased visual processing speeds during a sustained visual-spatial attention task. Furthermore, in vitro recordings of corticothalamic (CT) synapses revealed dramatic reductions in short-term facilitation, increased initial release probability, and earlier synaptic depression in VGluT1+/− mice. Our electron microscopy results show that VGluT1 concentration is reduced at CT synapses of hemizygous mice, but other features (such as vesicle number and active zone size) are unchanged. We conclude that VGluT1-haploinsuficiency decreases the dynamic range of gain modulation provided by CT feedback to the thalamus, and this deficiency contributes to the observed attentional processing deficit. We further hypothesize that VGluT1 concentration regulates release probability by applying a “brake” to an unidentified presynaptic protein that typically acts as a positive regulator of release.
Infectious Complications of Addiction: A Call for a New Subspecialty Within Infectious Diseases
Authors: Serota David P , Barocas Joshua A , Springer Sandra A
Published: August 2019

Infectious diseases (ID) physicians are increasingly responsible for the management of infectious consequences of substance use disorders (SUD). While we are often consulted for diagnosis and treatment of the infectious disease, it is clear that successful management of these infections requires a holistic approach, including acknowledgement and treatment of the underlying SUD. As we have learned through years of treating human immunodeficiency virus and hepatitis C virus infections, ID physicians have unique expertise in addressing both the infection and the complex biopsychosocial factors that underpin the infection. Many ID physicians have incorporated the management of addiction as part of their scope of practice, and here we seek to give a name and define the role of these ID/addiction dual specialists. We define the potential role of ID/addiction physicians in clinical care, health administration, and research, as well as provide recommendations to bolster the supply and reach of this burgeoning subspecialty.
Growth, external markets and stock–flow norms: a Luxemburg–Godley model of accumulation
Authors: Thompson Stephen
Published: August 2019

This paper explores the idea that in capitalist economies, external markets are the driving force behind long-run economic growth. To this end, a model is developed so that the dynamics of external demand, consumer spending, capital accumulation, income distribution and capitalists’ net financial assets can be analysed together as a complete system. The model shows how, in the long run, if capitalists adjust spending to keep financial wealth at desired levels, and investment reacts to aggregate demand in a Harrodian fashion, then this can cause the rate of capital accumulation to gravitate towards the growth rate of external markets. This occurs even if external demand only accounts for a small share of total economic activity. Based on this framework, the paper argues for a reinterpretation of the relationship between profits and growth during the neoliberal period in the USA.