bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the Engineering Properties of Modified Asphalt Using Aluminium Dross as a Filler
Authors: Busari A A , Adeboje A , Modupe A E , Fadugba G O , Loto R T , Abatan G O
Published: March 2021

Aluminum dross waste creates environmental burden for manufacturers and hence the need for its re-use. This experimental research assessed the engineering properties of modified asphalt using aluminium dross as a filer material. The aluminium dross used was obtained from a steel manufacturing industry. Elemental composition of the oxides was done using XRF equipment. Sieve analysis of the aluminium dross and the coarse aggregate was also assessed. Additionally, ductility, penetration, ball and ring and Marshall stability test were used in achieving the aim of this research. The outcome of the research revealed that 10-20% addition of the aluminium dross improved the stability of the modified asphalt. Physical observation revealed that the utilization of the waste stiffened the modified asphalt. The result showed that the addition of aluminium dross reduced the VMA. This will also increase the asphalt mix flushing. Additionally, at higher percentage addition of the waste the stiffness of the asphalt mix increases especially at a higher temperature. The use of this material will help in the reduction of solid waste and reduce the cost of management while reducing the cost of pavement construction in track with the trash to treasure drive.
Insight on the Electrodeposition Technology and Parameter for Corrosion Control of Structural Steel
Authors: Fayomi O S I , Olusanyan D , Loto C A , Udoye N E
Published: March 2021

Corrosion has been and still the world’s worst nightmare which costs hundreds and thousands of dollars for companies to maintain their equipment and repairs. Studies are being done all around the world to create the solution toward preventing the corrosion by surface engineering technology. One of the simplest and most cost effective methods to provide thin film coating for advance application is through electrolytic deposition route. However, bath framework has been a major concern for stable coating. Thus this studies look into the insight on the Corrosion, electrodeposition and visible additive for zinc plating technology.
Computational analysis of conductive heat transfer in a rectangular slab of stable boundary using Monte Carlo method
Authors: Udoye N E , Okolie S T A , Fayomi O S I , Banjo S O
Published: March 2021

Heat transfer is of immense importance in many engineering studies. Monte Carlo technique are broadly utilized in the operation research fields and atomic physics in which difficult problems above the existing tools of theoretical mathematics were resolved. The target of this study is to confirm the short duration in which heat transfer occurs in a quadrilateral slab where the temperature is provided throughout the borderline. An effort was made towards providing appropriate condition for the explanation of the heat transfer in a substance. The Shrinking Periphery Monte Carlo technique was utilized to obtain heat transfer in a helical pattern, upward and downward movement, which was compared with the standard Monte Carlo technique. The result of the study showed that the dimension of the quadrilateral slab determines the duration to calculate temperature dissemination in the system. The study revealed that the helical pattern is the shortest route in computing run time for temperature dispersal in a slab. The helical pattern is paramount in determining temperature distribution in a quadrilateral slab of stable state. The application of this technique to examine the conduction of heat in quadrilateral slabs produced good outcomes.
Overview impact of planning in production of a manufacturing sector
Authors: Afolalu S A , Matthew B B , Ongbali S O , Abdulkareem A , Emetere M E , Iheanetu O U
Published: March 2021

Every manufacturing sector that must attain maximum output with minimum input of resources will result in high marginal profit needs to pay more attention to planning. Production planning enhanced the coordination of production flow, thereby eliminating any constraint that may cause any disruption in the production line, hence highly demanded in organizational management. This paper revealed the impact of planning in production of a manufacturing sector. The main objectives is to identify the impact and challenges of planning in production sector of a manufacturing industry. Production planning determines the kind of activity to be carried out and the amount of time needed to perform this activity which is ultimate guide to any production line before its commencement. This article looked into the impact of planning in the production of the manufacturing sector. This will improve and foster productivity through high organization structuring.
Design and implementation of a smart watch
Authors: Tomoloju V , Usikalu M R , Ayara W A , Obafemi L N
Published: March 2021

Human connectivity is one of the major factors for productivity, especially in a school environment. The development of this watch is aimed at enhancing productivity by increasing the communication of both staff and students in the community. The watch is centred at creating a connected school community that will provide real-time communication to enhance the educational experience for students, staff and management regardless of their location within the school premises. This will enable members of the community to share information in real-time. The watch was designed with the Arduino pro-micro as the main processor. The watch leveraged WI-FI technology using the ESP8266-01 WI-FI module for connecting to a network and receiving of messages. The watch was connected to a secured intranet network. The watch has an average response time of approximately twenty-five (25) seconds to filter the data sent by the server and extract the message. Upon testing the design, the overall current draw of the watch was found to be approximately 78 mA. A lithium battery with a current capacity of 750 mAH was used for this project, which means that the battery will last for approximately nine hours. This kind of project is recommended for school communities so as to increase connectivity and enhance productivity.
Power line carrier technologies: a review
Authors: Amuta E O , Awelewa A , Olajube A , Somefun T E , Afolabi G , Uyi A S
Published: March 2021

This paper gives an elaborate insight into the Power Line Carrier (PLC) communication technology in the power system. It explores the various characteristics, properties, and advancement of the power line carrier system and individual analysis of its components. These components, however, are in concerning power line carrier communications over high voltage lines majorly used in transmission stations. Power Line Carrier (PLC) components, including wave traps, coupling capacitors, line matching units, were highlighted. The paper discussed the operation principle of the Power Line Carrier (PLC) system together with their functionalities and how it makes transmission of information and power possible. It gives us the step by step functionalities of the different parts and how they make the information dispersion possible. A communication strategy was deployed for the effective transmission of data and information over the power line channel. Challenges were considered, solutions, and future directions for the advancements in the power line carrier system were also provided.
Design of a digital fuel gauge with distance-to-zero indicator
Authors: Somefun T , Awosope C , Abdulkareem A , Ogelenya J , Orimogunje A , Somefun C
Published: March 2021

The fuel gauge in automobiles measures the amount of fuel in the tank through the sensing unit located in the tank and the analog indicator on the dashboard of the vehicle shows the quantity of fuel per time. This work is designed to ensure the display of the exact volume of fuel in the vehicle in digital form instead of the usual analog fuel indicator. It will also help to prevent inaccurate measurement of fuel at the filling station by showing the quantity of fuel during refuelling. So, a digital fuel gauge system has been designed and constructed to measure the exact quantity of fuel in the tank and display this measured quantity digitally in litres, by making use of an ultrasonic sensor and programmable microcontroller and the result obtain is ±0.96% accurate.
Quality assessment of sachet packed water in Omu-Aran, Kwara State
Authors: Gana A J , Adeniyi I A , Braimoh S O , Oguntayo D O , Ibitogbe E M , Ejigboye P O
Published: March 2021

The importance of potable water supply in the socioeconomic life of the public cannot be over emphasized. Hence, it is necessary to know and determine the quality of water especially drinking water. This study therefore investigates the quality of sachet packed water in Omu-Aran metropolis with a view of ascertaining its suitability for consumption purposes. Water samples from the three major factories were taken to laboratory for analysis. The parameters of interest are the Physical, chemical and biological contents. The results obtained showed that physical and chemical properties of the water samples are within the WHO/NIS standard limit for potable drinking water while biological and microbial examination showed that coliform count and DO of all the sachet water samples from factory ‘B’ and ‘C’ did not conform to the WHO/NIS standard. This indicates that the sachet packed water produced from factory ‘A’ were of good quality and hygienic for consumption while the ones from factory ‘B’ and ‘C’ should be improved upon in terms of their coliform count and DO contents. It is recommended that quality assurance be implemented through all the stages of production to ensure the quality of sachet packed water is improved for safe consumption.
Comparison of Reliability Based Design (RBD) With Eurocode 2 for A Singly Reinforced Concrete Beam
Authors: Olawale S O A , Akintunde O P , Afolabi M O , Agbede O A
Published: March 2021

This research compares the Reliability-Based Design (RBD) method with the Eurocode 2 (EC2) for a singly reinforced concrete beam. Advanced First Order Second Moment (AFOSM) was used and the equation for the ultimate limit state design consideration for Moment of resistance and Applied moment was applied. The parameters which were all functions of the Ultimate load, G were replaced respectively with variables and their derivatives G(x) obtained with being the characteristic strengths of concrete and the yield stress of steel respectively. Given the original vector space and the transformed reduced vector space, the Taylor series was used to expand the reduced vector space and thus reliability index ßx expressed. The procedure was then coded using JAVA to produce the Reliability Index and Probability of failure for respective steel ratio. The required probability index of 3.9 corresponds to 0.048% of the steel ratio. Typical analysis of a singly reinforced beam according to EC2 for b=300mm, h=500mm, d=447mm, cover of 40 mm, gave a steel ratio of 1.31 %. Comparing this to the reliability-based design of 0.048%, the code provision exceeded the RBD output by 2000 times and 63 times the minimum reinforcement requirement by the code.
Potentials of Cement Kiln Dust and Rice Husk Ash Blend on Strength of Tropical Soil for Sustainable Road Construction Material
Authors: Attah I C , Etim R K , Usanga I N
Published: March 2021

The growing problem of containing wastes in developing countries has led to endless research on the chances of converting these wastes to materials for sustainable engineering construction. This study through experimental assessment explores the potentials of cement kiln dust (CKD) and rice husk ash (RHA), in circumventing the inadequacies often encountered in deficient tropical soil thereby ensuring profitable engineering construction. Specimens were prepared by blending dosages of 0, 2, 4, 6 and 8 % CKD as well as 0, 3, 6, 9, 12 and 15 % RHA by requisite weight of soil. The investigated outcomes revealed increasing cation exchange capacity (CEC) with corresponding increase in pH for the various increased CKD-RHA composition. The Atterberg limits indicated a reduction trend with increasing CKD-RHA blend, signifying a drastic improvement in the plasticity tendency of the soil. While the maximum dry density (MDD) decreased with up shoot in optimum moisture content (OMC) at varying combined dosages of CKD and RHA, the CBR (soaked condition) increased steadily from 5 % (natural) to peak of 35 % at 8 % CKD / 15 % RHA blend. The highest CBR value in this study was not below the criterion of 20 – 30 % for sub-base as well as 10 – 15 % for subgrade road material. The regression analysis and analysis of variance from laboratory results validated the experimental outcome of using CKD-RHA blend to expressively enhance deficient lateritic soil. The outcome of this study has shown that CKD-RHA is recommended in improvement of strength of weak soil for either sub-base or more fittingly, subgrade of flexible pavement. Hence, using these waste materials will solve the twofold objective of proper waste management and good engineering materials for sustainability in construction of subgrade of flexible pavement.
Review of recently characterized Nigeria timber species for structural applications
Authors: Ede A N , Olomu O A , Akpabot A I , Oyebisi S O
Published: March 2021

The continuous rise of world population is putting much pressure on the housing and infrastructure stocks available to the society, thereby accentuating the need for more constructions and of course, more pressing demands on the depreciating natural resources. Today, the most used construction materials are concrete and steel, but the amount of pollutants deriving from their production has remained a source of great concern to the world. Finding solution to this environmental challenge has given rise to Sustainability Development Goals (SDGs), aimed at making the planet earth more conducive to living organisms. One of the viable approaches to reduce the high demand of construction industry on depreciating natural resources is the recourse to using more of renewable materials like timber. Timber is one of the few construction materials that have served all the ages of human lives in providing shelter. In this moment of pressing needs for more shelter and infrastructure, needed to make life more comfortable for man, the use of this renewable material must be sustained, but the strength characteristics must be known for more efficient and safe use. This research reviews recent characterization of some Nigerian timber species. This research emphasizes some good strength properties of recently reviewed Nigeria timber species, which will build the confidence of designers on safe judgment and choice of structural timber, help to reduce the cost of construction, thereby making residential houses more affordable to the lower class of the society. This will help to build a sustainable eco system for all.
Evaluation of Fire-Retardant Properties of Emulsion, Text-Coat and Gloss Paints Modified with Bio-Based Extract of Acalypha Wilkesiana
Authors: Ofuyatan O , Gbolade T , Adeniyi A , Ighalo J , Oluwafemi J
Published: March 2021

The impact of fire on concrete buildings has been found to tend towards strength reduction of the concrete building. Fire-retardant paints help to reduce the impact of fire on buildings and many researches are on to improve on fire-retardant paints. To this end, this paper investigated the fire-retardant properties of the bio-based extract of Acalypha wilkesiana in emulsion, text-coat and gloss paints. Acalypha leaves were subject to extraction in water and kerosene for three days. Emulsion, text-coat and gloss paints were produced. The fire point of the paint samples with a varying mass of extract was obtained to compare the flammability and obtain the optimum mass of extract needed for the best performance. The cube coated with 2 layers of text-coat paint of 0.45 g yielded the highest compressive strength. The best performing type of paint was text-coat paint. The coarse sand added during the production of text-coat paint assists in protecting the substrate material. Emulsion paint was the next best performing paint type while gloss paint was not advisable to be used for this purpose. The introduction of Acalypha wilkesiana as an additive had the fire point of the sample increased alongside the ignition time and the optimum mass of Acalypha wilkesiana extract that yielded the best fire-retardation of the paint was found to be 0.45g.
Material efficiency: a key sustainable manufacturing strategy
Authors: Ongbali S O , Oladipupo S , Afolalu S A , Udo M O , Leramo R O
Published: March 2021

Inefficient material utilization results in extra pressure on the environment for the extraction of more material to meet production demand and therefore makes the environment unsustainable. The survival of the manufacturing industry depends on its ability to balance several requirements to meet up with dynamic market demand particularly materials for production ranging from raw materials, intermediate materials to spare components for maintenance. In the past, sustainability and efficiency were no challenges to the manufacturers and material extraction from the environment was always below replenishment. Presently, the reverse is the case where the demand for production material has become incessant and surpasses supply on account of increasing population and modern manufacturing practices thereby resulting in irresponsible exploitation of raw material. This paper aims to evaluate the current efforts in the topic area to gain insight into the impact of material efficiency on the manufacturing performance concerning other manufacturing strategies alongside the environment. It appears from the review that the balance between manufacturing material extraction from the environment and the replenishment rate determines the sustainability of both the manufacturing system and the environment. Hence material efficiency is an index for sustainable manufacturing strategy. We recommend the future research direction to looks into the development and determination of balance between manufacturing material extraction from the environment and the replenishment rate for a sustainable future manufacturing.
Role of chemical equilibrium on the performance of an activated carbon–methanol adsorption refrigeration tube
Authors: Emetere M E , Oso-Ola P O , Afolalu S A
Published: March 2021

The main compartment that determines the functionality of the adsorption refrigerator is the adsorption refrigerator tube (ART). Many scientists have suggested certain ART configuration that would help improve its adsorption performance. The focus of the research is to determine causes of the ART malfunction via material failure. The linear driving force (LDF)-based models and the chemical kinetic reaction were taken into account to determine the chemical equilibrium of the material. It was observed that the successes of the adsorption refrigerator depend on the source material of the activated carbon and the level of impurity in the activated carbon.
UV and soft x-ray emission from gaseous and solid targets employing SiC detectors
Authors: TORRISI Alfio , WACHULAK Przemysław , TORRISI Lorenzo
Published: March 2021

A ns Nd:YAG pulsed laser has been employed to produce plasma from the interaction with a dense target, generating continuum and UV and soft x-ray emission depending on the laser parameters and target properties. The laser hits solid and gaseous targets producing plasma in high vacuum, which was investigated by employing a silicon carbide detector. The two different interaction mechanisms were studied, as well as their dependence on the atomic number. The photon emission from laser-generated plasma produced by solid targets, such as boron nitride (BN) and other elements (Al, Cu, Sn and Ta) and compounds such as polyethylene, has been compared with that coming from plasma produced by irradiating different gas-puff targets based on N2 and other gases (Ar, Xe, Kr, SF6). The experimental results demonstrated that the yields are comparable and, in both cases, increase proportionally to the target atomic number. The obtained results, focusing the attention on the advantages and drawbacks of the employed targets, are presented and discussed.
A Study on PAHs in the surface soil of the region around Qinghai Lake in the Tibet plateau: evaluation of distribution characteristics, sources and ecological risks
Authors: Zhang Zhongdi , Zhu Yadi , Shao Tianjie , Wang Ruojin , Chen Zongyan , Wei Peiru , Xu Zhiping , Li Dongze , Fu Lijuan , Wang Feier
Published: March 2021

In order to evaluate the pollution and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in the soil around the Qinghai Lake, 89 surface soil samples were collected in May 2019. After ultrasonic extraction and purification of silica gel-alumina-anhydrous Na2SO4 chromatographic column, GC-MS was used to test and analyze 16 kinds of monomer PAHs under priority control of USEPA in the samples, so as to study the distribution characteristics, sources and ecological risks. The results are shown as follows: (1) The total amount of 16 kinds of PAHs in the soil of the study area was 169.00 ∼ 638.94 μg·kg−1 , with an average of 318.37 μg·kg−1. The PAHs are dominated by dicyclic and tricyclic aromatic hydrocarbons, accounting for 40.89%∼70.73% of the mass fraction of PAHs, with an average of 49.22%, and phenanthrene accounts for the highest mass fraction. (2) The percentage of sampling points that exceeded the standard (200 μg·kg−1, which represents the upper limit of ‘no pollution’) was 87.6%, dominated by mild pollution(200 ∼ 600 μg·kg−1). The soil pollution in the west and south of the Qinghai Lake is relatively lighter than the north of the Qinghai Lake. (3) The toxicity equivalent concentration of TEQBaP for pyrene ranged from 8.19 to 42.35 μg·kg−1, with an average of 18.82 μg·kg−1. The ecological risk assessment results based on toxicity equivalent concentration and risk quality standard method showed that there was a low risk of PAHs in soil in this study area, and only a few areas exceeding the target reference value, mainly concentrated in the northern area of Qinghai Lake. (4) The results of source analysis by ratio method and principal component analysis method show that PAHs in the surface soil of the region around the Qinghai Lake come mainly from the combustion of oil and biomass.
Enhancing single photon emission through quasi-bound states in the continuum of monolithic hexagonal boron nitride metasurface
Authors: Cao Shun , Jin Yi , Dong Hongguang , Guo Tingbiao , He Jinlong , He Sailing
Published: March 2021

A patterned structure of monolithic hexagonal boron nitride (hBN) on a glass substrate, which can enhance the emission of the embedded single photon emitters (SPEs), is useful for onchip single-photon sources of high-quality. Here, we design and demonstrate a monolithic hBN metasurface with quasi-bound states in the continuum mode at emission wavelength with ultrahigh Q values to enhance fluorescence emission of SPEs in hBN. Because of ultrahigh electric field enhancement inside the proposed hBN metasurface, an ultrahigh Purcell factor (3.3 × 104) is achieved. In addition, the Purcell factor can also be strongly enhanced in most part of the hBN structure, which makes the hBN metasurface suitable for e.g. monolithic quantum photonics.
Maf1 regulates intracellular lipid homeostasis in response to DDR activation
Authors: Hammerquist Amy M. , Escorcia Wilber , Curran Sean P.
Published: March 2021

Surveillance of DNA damage and maintenance of lipid metabolism are critical factors for general cellular homeostasis. We discovered that in response to DNA damage-inducing UV light exposure, intact C. elegans accumulate intracellular lipids in a dose dependent manner. The increase in intracellular lipids in response to exposure to UV light utilizes mafr-1, a negative regulator of RNA polymerase III and the apical kinases atm-1 and atl-1 of the DNA damage response (DDR) pathway. In the absence of exposure to UV light, the genetic ablation of mafr-1 results in the activation of the DDR including increased intracellular lipid accumulation, phosphorylation of ATM/ATR targets proteins, and expression of the Bcl-2 homology region genes, egl-1 and ced-13. Taken together, our study reveals a places mafr-1 as a component the DDR pathway response to regulating lipid homeostasis following exposure to UV genotoxic stress.
Crop photoperiodism model 2.0 for the flowering time of sorghum and rice that includes daily changes in sunrise and sunset times and temperature acclimation
Authors: Clerget B , Sidibe M , Bueno C S , Grenier C , Kawakata T , Domingo A J , Layaoen H L , Gutiérrez-Palacios N D , Bernal J H , Trouche G , Chantereau J
Published: March 2021

Background and Aims

Daylength determines flowering dates. However, questions remain regarding flowering dates in the natural environment, such as the synchronous flowering of plants sown simultaneously at highly contrasting latitudes. The daily change in sunrise and sunset times is the cue for the flowering of trees and for the synchronization of moulting in birds at the equator. Sunrise and sunset also synchronize the cell circadian clock, which is involved in the regulation of flowering. The goal of this study was to update the photoperiodism model with knowledge acquired since its conception.

Methods

A large dataset was gathered, including four 2-year series of monthly sowings of 28 sorghum varieties in Mali and two 1-year series of monthly sowings of eight rice varieties in the Philippines to compare with previously published monthly sowings in Japan and Malaysia, and data from sorghum breeders in France, Nicaragua and Colombia. An additive linear model of the duration in days to panicle initiation (PI) and flowering time using daylength and daily changes in sunrise and sunset times was implemented.

Key Results

Simultaneous with the phyllochron, the duration to PI of field crops acclimated to the mean temperature at seedling emergence within the usual range of mean cropping temperatures. A unique additive linear model combining daylength and daily changes in sunrise and sunset hours was accurately fitted for any type of response in the duration to PI to the sowing date without any temperature input. Once calibrated on a complete and an incomplete monthly sowing series at two tropical latitudes, the model accurately predicted the duration to PI of the concerned varieties from the equatorial to the temperate zone.

Conclusions

Including the daily changes in sunrise and sunset times in the updated photoperiodism model largely improved its accuracy at the latitude of each experiment. More research is needed to ascertain its multi-latitudinal accuracy, especially at latitudes close to the equator.
Impact of Trade on Inequality: New Evidence of What, When, and Where
Authors: Siddique Abu Bakkar
Published: March 2021

The relationship between trade and inequality is complex, and the existing literature concludes that the impacts of trade on inequality are ambiguous. This article addresses this ambiguity and presents robust evidence that the effects of trade on inequality depend on economic development, when it occurred in recent decades, and their various measures. It proposes a novel identification strategy to solve for endogeneity problem in the literature by using trade as predicted by a gravity equation as an instrument for actual trade. It estimates the effect of both trade policies and trade volumes on inequality measured both before and after taxes and transfers. This article takes advantage of large and long panel data by conducting cross-examinations by economic development and economic history. The results show that international trade exacerbates inequality in the pre-taxes, but the effects disappear after taxes and transfers are adjusted; thus, it supports the compensation hypothesis. It increases inequality in rich economies while reducing it in poor economies, which confirms the standard Stolper and Samuelson theorem. Post-1991 trade experience was inequality increasing but pre-1991 trade was inequality decreasing; however, trade opening by reducing regulations, taxes, and tariffs was always inequality increasing. (JEL codes: D63, P33, and F63)
Cardiogenic shock in the context of newly diagnosed anomalous origin of the right coronary artery originating from the pulmonary artery: a case report
Authors: Kappel Coralea , Chow Justin , Ahmed Zeeshan , Schwalm Jon-David , Amin Faizan
Published: March 2021

Background

Anomalous right coronary artery (RCA) from the pulmonary artery (ARCAPA) is a rare congenital heart abnormality with varying clinical presentations, for which multiple imaging modalities are often required for diagnosis.

Case summary

We present a case of a 76-year-old female presenting with 2 weeks of palpitations and shortness of breath who was found to be in rapid atrial fibrillation (AF) with congestive heart failure. Despite initial medical management, the patient developed cardiogenic shock with anuric renal failure. Emergent right and left heart catheterization did not demonstrate any significant obstructive coronary artery disease but showed severe right ventricular (RV) failure and raised the possibility of an ARCAPA. This diagnosis was further corroborated by findings on a subsequent transoesophageal echocardiogram. In view of profound decline and limited anticipated improvement, the patient ultimately decided to pursue comfort measures in a hospice setting.

Discussion

We postulate that the underlying aetiology of our patient’s shock state was multifactorial, notably progressive RCA-territory ischaemia and RV failure, sepsis, and new-onset uncontrolled AF. In adults, unrecognized congenital heart disease can uncommonly cause cardiogenic shock. In our case, echocardiography and invasive angiography were integrated for the diagnosis of ARCAPA given the clinical circumstances that limited the use of cardiac computed tomography angiography.
Autoimmune hypophysitis as a cause of adrenocorticotropic hormone deficiency in pulmonary arterial hypertension: a case report
Authors: Ichihara Genki , Kataoka Masaharu , Katsumata Yoshinori , Fukuda Keiichi
Published: March 2021

Background 

Severe pulmonary arterial hypertension (PAH) is generally treated with multiple PAH-specific vasodilators. If these agents are unsuccessful, additional treatment options are scarce, and the prognosis is poor due to right-sided heart failure. Some of these severe cases are also accompanied by endocrinological side effects. The most common side effect of prostacyclin is thyroid dysfunction, but in very few cases, adrenocorticotropic hormone (ACTH) deficiency may occur.

Case summary 

A 35-year-old woman was diagnosed with hereditary PAH 2 years ago. Since her mean pulmonary arterial pressure was high, combination therapy of vasodilators, including prostacyclin, was introduced. Several months later, she was hospitalized with a persistent fever. Laboratory tests showed no findings suggestive of infection. However, hypereosinophilia and decreased secretion of ACTH and cortisol were noted, which led to the diagnosis of ACTH deficiency. A multimodal diagnostic approach, including pituitary magnetic resonance imaging and axillary lymph node biopsy, indicated that the aetiology of the ACTH deficiency was likely autoimmune hypophysitis. She was treated with hydrocortisone supplementation, which significantly relieved her condition.

Discussion 

Endocrinological side effects in PAH patients using prostacyclin should be carefully addressed. If right-sided heart failure worsens during the administration of prostacyclin, it is essential to determine whether it is due to progression of pulmonary hypertension or endocrinological side effects. Careful diagnosis and treatment are important for managing the haemodynamics and symptoms of PAH patients given prostacyclin.
Are treatment effect assumptions in orthodontic studies overoptimistic?
Authors: Seehra Jadbinder , Stonehouse-Smith Daniel , Cobourne Martyn T , Tsagris Michail , Pandis Nikolaos
Published: March 2021

Background

At the clinical trial design stage, assumptions regarding the treatment effects to be detected should be appropriate so that the required sample size can be calculated. There is evidence in the medical literature that sample size assumption can be overoptimistic. The aim of this study was to compare the distribution of the assumed effects versus that of the observed effects as a proxy for overoptimistic treatment effect assumptions at the study design stage.

Materials and method

Systematic reviews (SRs) published between 1 January 2010 and 31 December 2019 containing at least one meta-analysis on continuous outcomes were identified electronically. SR and primary study level characteristics were extracted from the SRs and the individual trials. Details on the sample size calculation process and assumptions and the observed treatment effects were extracted.

Results

Eighty-five SRs with meta-analysis containing 347 primary trials were included. The median number of SR authors was 5 (interquartile range: 4–7). At the primary study level, the majority were single centre (78.1%), utilized a parallel design (52%), and rated as an unclear/moderate level of risk of bias (34.3%). A sample size was described in only 31.7% (110/347) of studies. From this cohort of 110 studies, in only 37 studies was the assumed clinical difference that the study was designed to detect reported (37/110). The assumed treatment effect was recalculated for the remaining 73 studies (73/110). The one-sided exact signed rank test showed a significant difference between the assumed and observed treatment effects (P < 0.001) suggesting greater values for the assumed effect sizes.

Conclusions

Careful consideration of the assumptions at the design stage of orthodontic studies are necessary in order to reduce the unreliability of clinical study results and research waste.
Online prevention programmes for university students: stakeholder perspectives from six European countries
Authors: Irish Madeleine , Kuso Stefanie , Simek Monika , Zeiler Michael , Potterton Rachel , Musiat Peter , Nitsch Martina , Wagner Gudrun , Karwautz Andreas , Bolinski Felix , Karyotaki Eirini , Rovira Carla Soler , Etchemendy Ernestina , Herrero Rocio , Mira Adriana , Cormo Giulia , Baños Rosa , Garcia-Palacios Azucena , Ebert David D , Franke Marvin , Zarski Anna-Carlotta , Weisel Kiona , Berger Thomas , Dey Michelle , Schaub Michael P , Jacobi Corinna , Botella Cristina , Oliver Elia , Gordon Gemma , Spencer Lucy , Waldherr Karin , Schmidt Ulrike
Published: March 2021

Background

Students beginning university are at a heightened risk for developing mental health disorders. Online prevention and early intervention programmes targeting mental health have the potential to reduce this risk, however, previous research has shown uptake to be rather poor. Understanding university stakeholders’ (e.g. governing level and delivery staff [DS] and students) views and attitudes towards such online prevention programmes could help with their development, implementation and dissemination within university settings.

Methods

Semi-structured interviews, focus groups and online surveys were completed with staff at a governing level, university students and DS (i.e. student health or teaching staff) from six European countries. They were asked about their experiences with, and needs and attitudes towards, online prevention programmes, as well as the factors that influence the translation of these programmes into real-world settings. Results were analyzed using thematic analysis.

Results

Participating stakeholders knew little about online prevention programmes for university settings; however, they viewed them as acceptable. The main themes to emerge were the basic conditions and content of the programmes, the awareness and engagement, the resources needed, the usability and the responsibility and ongoing efforts to increase reach.

Conclusions

Overall, although these stakeholders had little knowledge about online prevention programmes, they were open to the idea of introducing them. They could see the potential benefits that these programmes might bring to a university setting as a whole and the individual students and staff members.
Synteny-Based Genome Assembly for 16 Species ofHeliconiusButterflies, and an Assessment of Structural Variation across the Genus
Authors: Seixas Fernando A , Edelman Nathaniel B , Mallet James
Published: March 2021

Heliconius butterflies (Lepidoptera: Nymphalidae) are a group of 48 neotropical species widely studied in evolutionary research. Despite the wealth of genomic data generated in past years, chromosomal level genome assemblies currently exist for only two species, Heliconius melpomene and Heliconius erato, each a representative of one of the two major clades of the genus. Here, we use these reference genomes to improve the contiguity of previously published draft genome assemblies of 16 Heliconius species. Using a reference-assisted scaffolding approach, we place and order the scaffolds of these genomes onto chromosomes, resulting in 95.7–99.9% of their genomes anchored to chromosomes. Genome sizes are somewhat variable among species (270–422 Mb) and in one small group of species (Heliconius hecale, Heliconius elevatus, and Heliconius pardalinus) expansions in genome size are driven mainly by repetitive sequences that map to four small regions in the H. melpomene reference genome. Genes from these repeat regions show an increase in exon copy number, an absence of internal stop codons, evidence of constraint on nonsynonymous changes, and increased expression, all of which suggest that at least some of the extra copies are functional. Finally, we conducted a systematic search for inversions and identified five moderately large inversions fixed between the two major Heliconius clades. We infer that one of these inversions was transferred by introgression between the lineages leading to the erato/sara and burneyi/doris clades. These reference-guided assemblies represent a major improvement in Heliconius genomic resources that enable further genetic and evolutionary discoveries in this genus.
The timing of human adaptation from Neanderthal introgression
Authors: Yair Sivan , Lee Kristin M , Coop Graham
Published: March 2021

Admixture has the potential to facilitate adaptation by providing alleles that are immediately adaptive in a new environment or by simply increasing the long-term reservoir of genetic diversity for future adaptation. A growing number of cases of adaptive introgression are being identified in species across the tree of life, however the timing of selection, and therefore the importance of the different evolutionary roles of admixture, is typically unknown. Here, we investigate the spatio-temporal history of selection favoring Neanderthal-introgressed alleles in modern human populations. Using both ancient and present-day samples of modern humans, we integrate the known demographic history of populations, namely population divergence and migration, with tests for selection. We model how a sweep placed along different branches of an admixture graph acts to modify the variance and covariance in neutral allele frequencies among populations at linked loci. Using a method based on this model of allele frequencies, we study previously identified cases of adaptive Neanderthal introgression. From these, we identify cases in which Neanderthal-introgressed alleles were quickly beneficial and other cases in which they persisted at low frequency for some time. For some of the alleles that persisted at low frequency, we show that selection likely independently favored them later on in geographically separated populations. Our work highlights how admixture with ancient hominins has contributed to modern human adaptation and contextualizes observed levels of Neanderthal ancestry in present-day and ancient samples.
Modeling Hessian-vector products in nonlinear optimization: new Hessian-free methods
Authors: Song L , Vicente L N
Published: March 2021

In this paper we suggest two ways of calculating interpolation models for unconstrained smooth nonlinear optimization when Hessian-vector products are available. The main idea is to interpolate the objective function using a quadratic on a set of points around the current one, and concurrently using the curvature information from products of the Hessian times appropriate vectors, possibly defined by the interpolating points. These enriched interpolating conditions then form an affine space of model Hessians or model Newton directions, from which a particular one can be computed once an equilibrium or least secant principle is defined. A first approach consists of recovering the Hessian matrix satisfying the enriched interpolating conditions, from which then a Newton direction model can be computed. In a second approach we pose the recovery problem directly in the Newton direction. These techniques can lead to a significant reduction in the overall number of Hessian-vector products when compared to the inexact or truncated Newton method, although simple implementations may pay a cost in the number of function evaluations and the dense linear algebra involved poses a scalability challenge.
Risk Estimation of Sexual Transmission of Zika Virus—United States, 2016–2017
Authors: Major Chelsea G , Paz-Bailey Gabriela , Hills Susan L , Rodriguez Dania M , Biggerstaff Brad J , Johansson Michael
Published: March 2021

Background

Zika virus (ZIKV) can be transmitted sexually but the risk of sexual transmission remains unknown. Most evidence of sexual transmission is from partners of infected travelers returning from areas with ZIKV circulation.

Methods

We used data from the US national arboviral disease surveillance system on travel- and sexually acquired ZIKV disease cases during 2016–2017 to develop individual-level simulations for estimating risk of male-to-female, male-to-male, and female-to-male sexual transmission of ZIKV via vaginal and/or anal intercourse. We specified parametric distributions to characterize individual-level variability of parameters for ZIKV persistence and sexual behaviors.

Results

Using ZIKV RNA persistence in semen/vaginal fluids to approximate infectiousness duration, male-to-male transmission had the highest estimated probability (1.3% [95% confidence interval, CI, .4%–6.0%] per anal sex act), followed by male-to-female and female-to-male transmission (0.4% [95% CI, .3%–.6%] per vaginal/anal sex act and 0.1% [95% CI, 0%–.8%] per vaginal sex act, respectively). Models using viral isolation in semen vs RNA detection to approximate infectiousness duration predicted greater risk of sexual transmission.

Conclusions

While likely insufficient to maintain sustained transmission, the estimated risk of ZIKV transmission through unprotected sex is not trivial and is especially important for pregnant women, as ZIKV infection can cause severe congenital disorders.
On the relationship between Type Ia supernova luminosity and host-galaxy properties
Authors: Murakami Yukei S , Stahl Benjamin E , Zhang Keto D , Chu Matthew R , McGinness Emma C , Patra Kishore C , Filippenko Alexei V
Published: March 2021

A string of recent studies has debated the exact form and physical origin of an evolutionary trend between the peak luminosity of Type Ia supernovae (SNe Ia) and the properties of the galaxies that host them. We shed new light on the discussion by presenting an analysis of ∼200 low-redshift SNe Ia in which we measure the separation of Hubble residuals (HR; as probes of luminosity) between two host-galaxy morphological types. We show that this separation can test the predictions made by recently proposed models, using an independently and empirically determined distribution of each morphological type in host-property space. Our results are partially consistent with the new HR–age slope, but we find significant scatter in the predictions from different galaxy catalogues. The inconsistency in age illuminates an issue in the current debate that was not obvious in the long-discussed mass models: HR–host-property models are strongly dependent on the methods employed to determine galaxy properties. While our results demonstrate the difficulty in constructing a universal model for age as a proxy for host environment, our results indeed identify evolutionary trends between mass, age, morphology, and HR values, encouraging (or requiring, if such trends are to be accounted for in cosmological studies) further investigation.
Ultrasound to identify systemic lupus erythematosus patients with musculoskeletal symptoms who respond best to therapy: the US Evaluation For mUsculoskeletal Lupus longitudinal multicentre study
Authors: Mahmoud Khaled , Zayat Ahmed S , Yusof Md Yuzaiful Md , Dutton Katherine , Teh Lee Suan , Yee Chee-Seng , D’Cruz David , Ng Nora , Isenberg David , Ciurtin Coziana , Conaghan Philip G , Emery Paul , Edwards Christopher J , Hensor Elizabeth M A , Vital Edward M
Published: March 2021

Objectives

To determine whether SLE patients with inflammatory joint symptoms and US synovitis/tenosyovitis achieve better clinical responses to glucocorticoids compared with patients with normal scans. Secondary objectives included identification of clinical features predicting US synovitis/tenosynovitis.

Methods

In a longitudinal multicentre study, SLE patients with physician-diagnosed inflammatory joint pain received intramuscular methylprednisolone 120 mg once. Clinical assessments, patient-reported outcomes and bilateral hand/wrist USs were collected at 0, 2 and 6 weeks. The primary outcome (determined via internal pilot) was the early morning stiffness visual analogue scale (EMS-VAS) at 2 weeks, adjusted for baseline, comparing patients with positive (greyscale ≥2 and/or power Doppler ≥1) and negative US. Post hoc analyses excluded FM.

Results

Of 133 patients, 78 had a positive US. Only 53 (68%) of these had one or more swollen joint. Of 66 patients with one or more swollen joint, 20% had a negative US. A positive US was associated with joint swelling, symmetrical small joint distribution and serology. The primary endpoint was not met: in the full analysis set (N = 133) there was no difference in baseline-adjusted EMS-VAS at week 2 [−7.7 mm (95% CI −19.0, 3.5); P = 0.178]. After excluding 32 patients with FM, response was significantly better in patients with a positive US at baseline [baseline-adjusted EMS-VAS at 2 weeks −12.1 mm (95% CI −22.2, −0.1); P = 0.049]. This difference was greater when adjusted for treatment [−12.8 mm (95% CI −22, −3); P = 0.007]. BILAG and SLEDAI responses were higher in US-positive patients.

Conclusion

In SLE patients without FM, those with a positive US had a better clinical response to therapy. Imaging-detected synovitis/tenosynovitis may be considered to decide on therapy and enrich clinical trials.