bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Vitamin K Oral Anticoagulants in Adults with Congenital Heart Disease: A Systematic Review
Authors: Stalikas Nikolaos , Doundoulakis Ioannis , Karagiannidis Efstratios , Bouras Emmanouil , Kartas Anastasios , Frogoudaki Alexandra , Karvounis Haralambos , Dimopoulos Konstantinos , Giannakoulas George
Published: June 2020

Adults with congenital heart disease (ACHD) experience more thromboembolic complications than the general population. We systematically searched and critically appraised all studies on the safety and efficacy of non-vitamin-K oral anticoagulants (NOACs) in adult patients with various forms of congenital heart disease. PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) were used, with duplicate extraction of data and risk of bias assessment. The Newcastle-Ottawa quality assessment scale was used to assess study quality. Three studies fulfilled the inclusion criteria and were analyzed. The total number of participants was 766, with a total follow-up of 923 patient-years. The majority of patients (77%) received a NOAC for atrial arrhythmias, while the remainder were prescribed NOACs for secondary (19%) or primary (4%) thromboprophylaxis. The annual rate of thromboembolic and major bleeding events was low: 0.98% (95% CI: 0.51–1.86) and 1.74% (95% CI: 0.86–3.49) respectively. In Fontan patients, the annual rate of thromboembolic and major bleeding events was 3.13% (95% CI: 1.18–8.03) and 3.17% (95% CI: 0.15–41.39) respectively. NOACs appear safe and effective in ACHD without mechanical prostheses. Additional studies are, however, needed to confirm their efficacy in complex ACHD, especially those with a Fontan-type circulation.
Differential Th Cell-Related Immune Responses in Young Physically Active Men after an Endurance Effort
Authors: Kostrzewa-Nowak Dorota , Nowak Robert
Published: June 2020

The participation of T cell subsets in the modulation of immunity in athletes triggered by maximal effort was investigated. In total, 80 physically active young men (range 16–20 years) were divided into 5 age groups: 16, 17, 18, 19, and 20 years old. They performed efficiency tests on mechanical treadmills until exhaustion. White blood cell (WBC) and lymphocyte (LYM) counts were determined, and the type 1 (Th1), type 2 (Th2) helper T cells, T helper 17 (Th17), and T regulatory (Treg) cell distribution and plasma levels of selected cytokines were analyzed. An increase in WBC and LYM counts after the test and in Th1 and Treg cells after the test and in recovery was observed. There were no changes in Th2 cells. An increase in interleukins (IL): IL-2 and IL-8 was observed. The IL-6 level was altered in all studied groups. IL-17A and interferon gamma (IFN-γ) levels were increased in all studied groups. The mechanism of differential T cell subset activation may be related to athletes’ age. The novel findings of this study are the involvement of Th17 cells in post-effort immune responses and the participation of IL-6 in post-effort and the long-term biological effect of endurance effort.
Pain Neuroscience Education for Children with Functional Abdominal Pain Disorders: A Randomized Comparative Pilot Study
Authors: Pas Roselien , Rheel Emma , Van Oosterwijck Sophie , Foubert Anthe , De Pauw Robby , Leysen Laurence , Roete Ann , Nijs Jo , Meeus Mira , Ickmans Kelly
Published: June 2020

This article explores the effectiveness of a newly developed Pain Neuroscience Education program for children (PNE4Kids) with functional abdominal pain disorder (FAPD). Children (6–12 years) with FAPD were randomly assigned to 1) the experimental group (n = 14), participating in one hypnotherapy session (i.e., usual care) and one additional PNE4Kids session, or 2) the control group (n = 14), participating in two hypnotherapy sessions. Parental pain catastrophizing, the child’s functional disability (parental-proxy), pain-related fear (parent-proxy) and pain intensity, were assessed at baseline and one and three weeks after each therapy session. Pressure algometry and a conditioned pain modulation paradigm were performed at baseline and three weeks after completion of the last therapy session. Parents from both the experimental as well as the control group showed significantly less parental pain catastrophizing (p < 0.01). Children showed significantly less functional disability (p < 0.05), pain-related fear (p < 0.01) and local pressure pain sensitivity (p < 0.05) at short-term follow-up (three weeks after last intervention) in both groups. No significant (p > 0.05) between-group differences were found. Hypnotherapy combined with PNE4Kids did not result in better clinical outcomes compared to hypnotherapy alone. Study limitations include the application of one single PNE4Kids session and the short follow-up time.
Remanufacturing of Woven Carbon Fibre Fabric Production Waste into High Performance Aligned Discontinuous Fibre Composites
Authors: Aravindan Parthasarathi , Becagli Federico , Longana Marco L. , Blok Lourens G. , Pozegic Thomas R. , Huntley Samantha J. , Rendall Thomas , Hamerton Ian
Published: June 2020

The composites industry generates considerable volumes of waste in a wide variety of forms, from the production of by-products to end-of-life parts. This paper focuses on the remanufacturing of dry fibre off-cuts, produced during the composite fabric weaving process, into highly aligned discontinuous fibre prepreg tapes with High Performance Discontinuous Fibre (HiPerDiF) technology. Unidirectional laminate specimens are prepared using various combinations of fibre lengths and tested in tension, obtaining a stiffness of 80 GPa, a strength of 800 MPa, and a failure strain of 1%. Several applications are envisaged for the produced tape: adhesive film, feedstock for filament winding, and tow for weaved fabrics. This work demonstrates the possibility to extract value from what is currently considered manufacturing waste.
Fiber Orientation Predictions—A Review of Existing Models
Authors: Kugler Susanne Katrin , Kech Armin , Cruz Camilo , Osswald Tim
Published: June 2020

Fiber reinforced polymers are key materials across different industries. The manufacturing processes of those materials have typically strong impact on their final microstructure, which at the same time controls the mechanical performance of the part. A reliable virtual engineering design of fiber-reinforced polymers requires therefore considering the simulation of the process-induced microstructure. One relevant microstructure descriptor in fiber-reinforced polymers is the fiber orientation. This work focuses on the modeling of the fiber orientation phenomenon and presents a historical review of the different modelling approaches. In this context, the article describes different macroscopic fiber orientation models such as the Folgar-Tucker, nematic, reduced strain closure (RSC), retarding principal rate (RPR), anisotropic rotary diffusion (ARD), principal anisotropic rotary diffusion (pARD), and Moldflow rotary diffusion (MRD) model. We discuss briefly about closure approximations, which are a common mathematical element of those macroscopic fiber orientation models. In the last section, we introduce some micro-scale numerical methods for simulating the fiber orientation phenomenon, such as the discrete element method (DEM), the smoothed particle hydrodynamics (SPH) method and the moving particle semi-implicit (MPS) method.
Energetic and Biomechanical Contributions for Longitudinal Performance in Master Swimmers
Authors: Marinho Daniel A. , Ferreira Maria I. , Barbosa Tiago M. , Vilaça-Alves José , Costa Mário J. , Ferraz Ricardo , P. Neiva Henrique
Published: June 2020

Background: The current study aimed to verify the changes in performance, physiological and biomechanical variables throughout a season in master swimmers. Methods: Twenty-three master swimmers (34.9 ± 7.4 years) were assessed three times during a season (December: M1, March: M2, June: M3), in indoor 25 m swimming pools. An incremental 5 × 200 m test was used to evaluate the speed at 4 mmol·L−1 of blood lactate concentration (sLT), maximal oxygen uptake (VO2max), peak blood lactate ([La-]peak) after the test, stroke frequency (SF), stroke length (SL), stroke index (SI) and propelling efficiency (ηp). The performance was assessed in the 200 m front crawl during competition. Results: Swimming performance improved between M1, M2 (2%, p = 0.03), and M3 (4%, p < 0.001). Both sLT and VO2max increased throughout the season (4% and 18%, p < 0.001, respectively) but not [La-]peak. While SF decreased 5%, SL, SI and ηp increased 5%, 7%, and 6% (p < 0.001) from M1 to M3. Conclusions: Master swimmers improved significantly in their 200 m front crawl performance over a season, with decreased SF, and increased SL, ηp and SI. Despite the improvement in energetic variables, the change in performance seemed to be more dependent on technical than energetic factors.
Secondary Scoliosis as a Complication of Acute Transverse Myelitis in a Child
Authors: D’Amico Silvia , Pavone Piero , Testa Gianluca , Greco Filippo , Marino Lidia , Smilari Pierluigi , Pavone Vito
Published: June 2020

Acute transverse myelitis (ATM) is a rare neurological condition that affects the spinal cord. Several events, including infections, autoimmune conditions, inflammatory, and drug-induced factors, may cause this disorder. Correct and rapid etiological diagnosis is necessary in order to start appropriate treatment that mainly consists of immunomodulating therapy, high dose intravenous corticosteroids, and in plasma exchange in noninfectious cases. The outcome is varied and depends on several factors. In children, the prognosis is usually good. We report a case of an 11-year-old boy who presented with interscapular pain, right leg steppage, homolateral hyposthenia of the upper limb, and signs of autonomic dysfunction. After performing specific and instrumental exams, a diagnosis of transverse myelitis was reached, and appropriate therapy was performed. A few days post-treatment, the child developed a secondary scoliosis, involving a thoracolumbar curve with loss of cervical and lumbar lordosis. After rehabilitative treatment was undertaken for 12 months, a complete recovery and normal restoration of spinal physiological curves was obtained. The pediatric cases of ATM have a good response to steroid therapy combined with physiotherapy. Collaboration among the various specialists is worthwhile, in order to lead to a correct and rapid diagnosis.
Idleness-Aware Dynamic Power Mode Selection on the i.MX 7ULP IoT Edge Processor
Authors: Di Mauro Alfio , Fatemi Hamed , de Gyvez Jose Pineda , Benini Luca
Published: June 2020

Power management is a crucial concern in micro-controller platforms for the Internet of Things (IoT) edge. Many applications present a variable and difficult to predict workload profile, usually driven by external inputs. The dynamic tuning of power consumption to the application requirements is indeed a viable approach to save energy. In this paper, we propose the implementation of a power management strategy for a novel low-cost low-power heterogeneous dual-core SoC for IoT edge fabricated in 28 nm FD-SOI technology. Ss with more complex power management policies implemented on high-end application processors, we propose a power management strategy where the power mode is dynamically selected to ensure user-specified target idleness. We demonstrate that the dynamic power mode selection introduced by our power manager allows achieving more than 43% power consumption reduction with respect to static worst-case power mode selection, without any significant penalty in the performance of a running application.
Effects of Refill Friction Stir Spot Weld Spacing and Edge Margin on Mechanical Properties of Multi-Spot-Welded Panels
Authors: Lakshmi Balasubramaniam Guruvignesh , Boldsaikhan Enkhsaikhan , Fukada Shintaro , Fujimoto Mitsuo , Kamimuki Kenichi
Published: June 2020

Refill friction stir spot welding (RFSSW) is an emerging technology for joining aerospace aluminum alloys. The aim of the study is to investigate the effects of the refill friction stir spot weld spacing and the edge margin on the mechanical properties of multi-spot-welded AA7075-T6 panels. AA7075-T6 is a baseline aerospace aluminum alloy used in aircraft structures. The study employs an innovative robotic RFSSW system that is designed and developed by Kawasaki Heavy Industries (KHI). The experimental strategy uses Design of Experiments (DoE) to characterize the failure loads of multi-spot-welded panels in terms of the spot weld spacing, edge margin, and heat-affected zone (HAZ) of the spot weld. The RFSSW process leaves behind a thermal “imprint” as HAZ in heat-treatable aluminum alloys. According to the DoE results, larger spot weld spacings with no HAZ overlap produce higher failure loads of multi-spot-welded panels. On the other hand, edge margins that are equal to or less than the spot weld diameter demonstrate abnormal plastic deformations, such as workpiece edge swelling and weld crown dents, during the RFSSW process. The larger edge margins do not demonstrate such abnormal deformations during the welding process.
Impacts of Hurricane Disturbance on Water Quality across the Aquatic Continuum of a Blackwater River to Estuary Complex
Authors: Schafer Tracey , Ward Nicholas , Julian Paul , Reddy K. Ramesh , Osborne Todd Z.
Published: June 2020

Hurricanes cause landscape-scale disturbances that affect biogeochemical cycling and water quality in coastal ecosystems. During Hurricane Irma’s passage through northern Florida, water movements driven by wind velocities up to 105 km h−1 caused a salinity peak in an estuary/blackwater river complex. Water quality was monitored across the 15 km site to detect the magnitude and duration of disturbance. Saline water intruded 15 km inland into a freshwater portion of the river that peaked at a salinity of 2 psu. Due to the volume of precipitation from the hurricane, significant runoff of freshwater and dissolved organic matter (DOM) caused a decrease in salinity, dissolved oxygen (DO), and Chlorophyll-a concentrations while increasing turbidity and fluorescent dissolved organic matter (fDOM). The disturbance caused rapid changes observed by in-situ water quality monitors over a 3-week period, but some effects persisted for longer periods as shown by 3-month weekly water sampling. This disturbance caused shifts in DOM loading, altered salinity dynamics, and reshaped landscapes due to wind and wave surge both in upland marsh and downstream estuary. Hurricane disturbance temporarily and abruptly alters the aquatic continuum, and observations of system response can help us understand the mechanisms associated with ecosystem resilience and recovery.
Suction Bucket Pile–Soil–Structure Interactions of Offshore Wind Turbine Jacket Foundations Using Coupled Dynamic Analysis
Authors: Plodpradit Pasin , Kwon Osoon , Dinh Van Nguyen , Murphy Jimmy , Kim Ki-Du
Published: June 2020

This paper presents a procedure for the coupled dynamic analysis of offshore wind turbine–jacket foundation-suction bucket piles and compares the American Petroleum Institute (API) standard method and Jeanjean’s methods used to model the piles. Nonlinear springs were used to represent soil lateral, axial, and tip resistances through the P–Y, T–Z, and Q–Z curves obtained by either API’s or Jeanjean’s methods. Rotational springs with a stiffness equated to the tangent or secant modulus characterized soil resistance to acentric loads. The procedure was implemented in X-SEA program. Analyses of a laterally loaded single pile in a soft clay soil performed in both the X-SEA and Structural Analysis Computer System (SACS) programs showed good agreements. The behaviors of a five MW offshore wind turbine system in South Korea were examined by considering waves, current, wind effects, and marine growth. In a free vibration analysis done with soil stiffness through the API method, the piles were found to bend in their first mode and to twist in the second and third modes, whereas the first three modes using Jeanjean’s method were all found to twist. The natural frequencies resulting from Jeanjean’s method were higher than those from the API method. In a forced vibration analysis, the system responses were significantly influenced by soil spring stiffness type. The procedure was found to be computationally expensive due to spring nonlinearities introduced.
A Kinematic Collision Box Algorithm Applied for the Anti-Collision System of Offshore Drilling Vessels
Authors: Nguyen Duy Thanh , Jung Kwang Hyo , Kwon Ki-Youn , Ku Namkug , Lee Jaeyong
Published: June 2020

With the advances in technology and the automation of drilling platforms, the Anti-Collision System (ACS) has appeared as an affordable technology, which is intended to keep equipment on the drilling floor working harmoniously and to prevent the potential hazards associated with accidents. However, the specialty of the machinery on the drilling floor requires a distinguished structure for the ACS and a reliable collision-avoidance algorithm, which is not similar to any algorithm in other applications, such as automobiles and robotics. The aim of this paper is to provide a comprehension of the configuration of an ACS in an Integrated Drilling System and to develop a practical anti-collision algorithm that can be applied to the machine arrangement for an offshore drilling operation. By analyzing the motions and using kinematic parameters, such as the speed and deceleration information of drilling equipment, a kinematic collision box algorithm is developed to eliminate the limitation of conventional algorithms. While the conventional collision-avoidance algorithm uses a collision box with fixed size, the kinematic collision box algorithm uses a collision box with a flexible scale that can be correspond to the velocity and deceleration rate of the equipment. Several operating scenarios are simulated by a visual model of ACS to authenticate the functionality of the proposed algorithm. The operation of the top drive is an outstanding scenario. Only 2.25 s are required to stop the top drive from its maximum velocity, and a conventional algorithm uses this number to create a fixed bounding box. Also, the kinematic collision box algorithm uses the real-time data of velocity and acceleration to adjust the scale of the bounding box when the speed of the top drive increases from 0 to its maximum value. The simulation result illustrates the reliability and advances of the kinematic collision box algorithm in performing the collision-avoidance function in ACS compared to the conventional algorithm.
Monitoring the Morphodynamic Cannibalization of the Rossbeigh Coastal Barrier and Dune System over a 19-Year Period (2001–2019)
Authors: Nuyts Siegmund , O'Shea Michael , Murphy Jimmy
Published: June 2020

This research presents a study on the morphodynamic evolution of the Rossbeigh coastal barrier and its dune system, located in Dingle Bay, County Kerry, Ireland. The study examines the evolution of the system over a 19-year period (2001–2019) through remote sensing, geographic information system (GIS) analysis, and field-based surveys. This research provides an ideal opportunity to examine a natural erosion event, referred to as cannibalization on a coastal barrier and its dune system. Since the beginning of this century, significant erosion has been visible on the coastal barrier, with the erosion eventually leading to a breaching event in the winter of 2008/2009. Over the study period, analysis has shown that the vegetated dunes decreased by more than 60 percent, the width of the breached area reached a maximum width of over 1 km and a change in orientation and appearance on the coastal barrier has been quantified. The analysis identifies a growing drift-aligned zone, contrasted with a reduction in the stable swash-aligned zone. Significantly, the point between these zones (i.e., the hinge point) has been shown to have moved by more than 1 km also. The migration of this hinge point and cannibalization of the dunes are illustrated. Finally, the potential mechanism for beach healing is identified, utilizing the rich datasets collected during the study, thus providing an insight into the long-term behavior of a dynamic coastal barrier system undergoing naturally driven cannibalization.
Native Arbuscular Mycorrhizal Fungi Characterization from Saline Lands in Arid Oases, Northwest China
Authors: Lumini Erica , Pan Jing , Magurno Franco , Huang Cuihua , Bianciotto Valeria , Xue Xian , Balestrini Raffaella , Tedeschi Anna
Published: June 2020

Arbuscular mycorrhizal fungi (AMF) colonize land plants in almost every ecosystem, even in extreme conditions, such as saline soils. In the present work, we report the mycorrhizal capacity of rhizosphere soils collected in the dry desert region of the Minqin Oasis, located in the northwest of China (Gansu province), which is characterized by several halophytes. Lycium spp. and Peganum nigellastrum were used as trap plants in a greenhouse experiment to identify autochthonous AMF associated with the halophytes’ rhizospheres. Morphological observations showed the typical AMF structures inside roots. Twenty-six molecularly distinct AMF taxa were recovered from soil and root DNA. The taxonomical diversity mirrors the several AMF adapted to extreme environmental conditions, such as the saline soil of central China. Knowledge of the AMF associated with halophytes may contribute to select specific fungal isolates to set up agriculture strategies for protecting non-halophyte crop plants in saline soils.
Evaluation of a New Culture Protocol for Enhancing Fungal Detection Rates in Respiratory Samples of Cystic Fibrosis Patients
Authors: Engel Tobias G.P. , Tehupeiory-Kooreman Marlou , Melchers Willem J.G. , Reijers Monique H. , Merkus Peter , Verweij Paul E.
Published: June 2020

Cystic fibrosis (CF) can be complicated by fungal infection of the respiratory tract. Fungal detection rates in CF sputa are highly dependent on the culture protocol and incubation conditions and thus may lead to an underestimation of the true prevalence of fungal colonization. We conducted a prospective study to evaluate the additional value of mucolytic pre-treatment, increased inoculum (100 μL), additional fungal culture media (Sabouraud agar; SAB, Medium B+, Scedosporium selective agar; SceSel+ and Dichloran-Glycerol agar; DG18) and longer incubation time (3 weeks) compared with our current protocol. Using the new protocol, we prospectively analyzed 216 expectorated sputum samples from adult and pediatric CF patients (n = 77) and compared the culture yield to a three year retrospective cohort that used direct 10 μL loop inoculation on SAB with 5 days incubation (867 sputum samples/103 patients). Detection rates for molds increased from 42% to 76% (p < 0.0001). Twenty-six percent of cultures were polymicrobial in the prospective cohort as opposed to 4.7% in the retrospective cohort (p < 0.0001). Colonization rate with A. fumigatus increased from 36% to 57%. SAB and DG18 showed the highest detection rates for all molds (SAB 58.6%; DG18 56.9%) and DG18 had the best performance for molds other than A. fumigatus. The larger sample volume and longer incubation also contributed to the increased recovery of molds. The introduction of a modified fungal culture protocol leads to a major increase in detection rate and the diversity of molds, which influences fungal epidemiology and may have implications for treatment decisions.
Personalized Nursing: How Life Satisfaction and Occupational Burnout Influence New Competences of Polish Nurses
Authors: Bartosiewicz Anna , Łuszczki Edyta , Dereń Katarzyna
Published: June 2020

Nursing around the world is developing very dynamically and nurses are undertaking increasingly complex tasks. The extension of entitlements for nurses in Poland in the area of writing prescriptions and referrals for diagnostic tests seems to be a response to the development and changes occurring in this profession. This will improve the standards of patient care, increase access to medical services and improve the professional status of this group. The aim of this study was to analyze the opinions of nurses regarding their preparedness for administering prescriptions and referrals for diagnostic tests depending on their sense of life satisfaction and the level of occupational burnout. The study was conducted among primary care nurses using a survey technique, using a standardized scale of life satisfaction and a scale to measure burnout. In addition, this study used a proprietary survey questionnaire containing questions regarding the self-assessment of preparedness for new competences. The results showed that nurses do not feel well prepared for new tasks. The levels of life satisfaction and burnout of the nurses surveyed significantly influenced confidence regarding their preparedness for writing prescriptions and referrals for diagnostic tests. Polish nurses have a very cautious attitude towards new competences. However, this is a breakthrough and the first step towards approving the role of an advanced practice nurse in our country.
The Bluegreen Algae (AFA) Consumption over 48 h Increases the Total Number of Peripheral CD34+ Cells in Healthy Patients: Effect of Short-Term and Long-Term Nutritional Supplementation (Curcumin/AFA) on CD34+ Levels (Blood)
Authors: Merino José Joaquín , Cabaña-Muñoz María Eugenia , Pelaz María Jesús
Published: June 2020

Several active principles from plants could trigger the release of stem cells from the bone marrow. Stem cell mobilizers have shown side effects in patients. Thus, the purpose of this paper is to find the natural products from plants (curcuminoids, glycosinolate of sulforaphane, AFA bluegreen algae), which could be potential stem mobilizes without adverse side effects. The antioxidant curcumin [1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-2,5-dione], glycosinolate of sulforaphane (broccoli) or AFA (Aphanizomenon flos) extract promote beneficial effects in patients. The number of circulating stem cells were monitored by HSC marker-CD34 by flow cytometry in peripheral blood from healthy subjects. CD34 is a hematological stem cells (HSC) marker. A double-blind study was conducted in 22 healthy subjects. We have evaluated whether short-term AFA—Aphanizomenon flos aquae—algae or curcuminoids consumption (powder or liquid formulation) over 48 consecutive hours could increase the total number of peripheral CD34+ blood cells (n = 22, n = 5 subjects/group). The total number of circulating CD34+ cells were quantified after short-term and long-term nutritional supplementation; their levels were compared with their own basal levels (n = 5/group, controls: before taking any supplement) or placebo-treated patients (n = 7); their average age was 54 years old. We also evaluated whether long-term nutritional supplementation with several nutraceuticals could enhance HSC mobilization by increasing the total number of peripheral CD-34+ cell after seven or 38 consecutive days of administration (n = 5, with seven placebo-treated patients). The long-term administration take place with these doses/day [curcuminoids: 2000 mg/day, equivalent to 120 mg of curcuminoids/day), glycosinolate of sulforaphane (66 mg/day), plus AFA Algae bluegreen extract (400 mg/day)]. On the last day (10 a.m.) of treatment, blood samples were collected six hours after taking these supplements; the average age was 54 years old. Notably, the blue green AFA algae extract consumption over 48 h enhances HSC mobilization by increasing the total number of peripheral CD34+ cells. The long-term administration with curcuminoids, glycosinolate of sulforaphane, and AFA bluegreen algae extract also increased the total number of CD34-HSC cells after seven or 38 days of consecutive of administration in healthy subjects.
Intraday Jumps, Liquidity, and U.S. Macroeconomic News: Evidence from Exchange Traded Funds
Authors: Jurdi Doureige
Published: June 2020

This paper uses two highly liquid S&P 500 and gold exchange-traded funds (ETFs) to evaluate the impact of liquidity and macroeconomic news surprises on the frequency of observing intraday jumps. It explicitly addresses market microstructure noise-induced biases in realized estimators used in jump detection tests and applies non-parametric intraday jump detection tests. The results show a significant increase in trading costs and elevated levels of information asymmetry before observing jumps. Depth, resiliency, and trading activity are associated with the frequency of observing intraday jumps and cojumps. The ability of liquidity variables to predict intraday jumps persists after controlling for news surprises. Results show that intraday jump realizations affect the price discovery of ETFs.
Ecotourism Market Segmentation in Bali, Indonesia: Opportunities for Implementing REDD+
Authors: Choi Gayoung , Kim Jongmin , Sawitri Made Yaya , Lee Sue Kyoung
Published: June 2020

Ecotourism has been promoted in many regions of Indonesia as a viable platform for reducing emissions from deforestation and forest degradation in developing countries (REDD+) by providing incentives to local communities for their forest conservation efforts. This study aims to find opportunities for implementing REDD+ in Bali through ecotourism market segmentation analysis, and to provide policy implications to other developing countries under similar circumstances. The results indicate that two clusters—“nature-seeking responsible tourists” and “wellness-seeking responsible tourists”—were selected as Bali’s target clusters. Since both have higher motivation and a more responsible attitude than other clusters, they are capable of not only sustaining a symbiotic relationship between the ecotourism destination and the visitor, but also attracting potential tourists with similar characteristics, ultimately contributing to the sustainable tourism business in the region. In conclusion, building a marketing strategy based on the understanding of the tourists will promote forest conservation effectively, while also playing an important role in REDD+ implementation by bringing sustainable tourism income to the local community.
The Nexus between Peri-Urban Transformation and Customary Land Rights Disputes: Effects on Peri-Urban Development in Trede, Ghana
Authors: Owusu Ansah Barikisa , Chigbu Uchendu Eugene
Published: June 2020

Typically, peri-urban areas are havens and vulnerable receptors of customary land rights (CLRs) disputes due to the intrusion of urban activities or an uncoordinated mix of both. Although it is a dictum that CLRs cause setbacks to socioeconomic and spatial development, there seems to be a paucity of empirical studies on the effects of the CLRs disputes on the development of peri-urban areas, especially in developing countries, such as Ghana. This study addresses this issue by establishing a link between peri-urban transformation and emerging CLRs disputes, while assessing the effects of these disputes on the development of peri-urban areas. The study adopted a problem-centered mixed methods approach with a focus on the case of Trede, a town in Ghana transitioning from rural to urban status. Findings reveal that the changes leading to enhancing of peri-urban transformation are also the same changes inducing CLRs disputes in the area. It was found that the implementation of a local land use plan is a critical driver of CLRs disputes in Trede. A land-use plan implemented as a major step in converting rural lands into urban plots, triggered tenurial changes, land market development, high land values, loss of agricultural land, etc., which become recipes for the CLRs disputes in the study area. These CLRs disputes have hatched detrimental consequences on the economic, social, and physical developmental trajectories of Trede. As a way forward, the study proposes measures for peri-urban land management and CLRs dispute prevention.
The Impact of the Process of Academic Education on Differences in Landscape Perception between the Students of Environmental Engineering and Civil Engineering
Authors: Greinert Andrzej , Mrówczyńska Maria
Published: June 2020

As technical and technological progress takes place, there is dissonance between teaching good engineering and technological techniques and respect for the landscape. Engineering students are educated to act as initiators and performers of activities that change space. The purpose of this study is to answer question regarding how the engineering students recognize problems related to shaping the landscape. In the years 2012–2015, surveys were conducted in a group of 274 students of the University in their final year of environmental engineering and civil engineering studies, in order to find the main characteristics related to the problem. Students tended to assess the landscape in a manner determined by their education in natural science—emphasizing the division between the well-shaped natural landscape and the malformed anthropogenic one. There were differences between the groups of students—civil engineering students noticed the qualities of architectural objects and shaped greenery in their perception of the landscape in urban areas more often than the environmental engineering students did. There were no differences in the perception of the landscape in rural areas. The harmonious landscape was described as rural, modern, undeveloped and common. The landscape regarded as degraded was built-up and common. There were no changes in the perception of the landscape resulting from the educational profile among the environmental engineering students. The time has come to change methods of teaching the students of engineering and technical sciences about the landscape. This should result in an improvement in their perception of landscape phenomena.
Universal Codons with Enrichment from GC to AU Nucleotide Composition Reveal a Chronological Assignment from Early to Late Along with LUCA Formation
Authors: Gospodinov Anastas , Kunnev Dimiter
Published: June 2020

The emergence of a primitive genetic code should be considered the most essential event during the origin of life. Almost a complete set of codons (as we know them) should have been established relatively early during the evolution of the last universal common ancestor (LUCA) from which all known organisms descended. Many hypotheses have been proposed to explain the driving forces and chronology of the evolution of the genetic code; however, none is commonly accepted. In the current paper, we explore the features of the genetic code that, in our view, reflect the mechanism and the chronological order of the origin of the genetic code. Our hypothesis postulates that the primordial RNA was mostly GC-rich, and this bias was reflected in the order of amino acid codon assignment. If we arrange the codons and their corresponding amino acids from GC-rich to AU-rich, we find that: 1. The amino acids encoded by GC-rich codons (Ala, Gly, Arg, and Pro) are those that contribute the most to the interactions with RNA (if incorporated into short peptides). 2. This order correlates with the addition of novel functions necessary for the evolution from simple to longer folded peptides. 3. The overlay of aminoacyl-tRNA synthetases (aaRS) to the amino acid order produces a distinctive zonal distribution for class I and class II suggesting an interdependent origin. These correlations could be explained by the active role of the bridge peptide (BP), which we proposed earlier in the evolution of the genetic code.
Carotenoid Raman Signatures Are Better Preserved in Dried Cells of the Desert Cyanobacterium Chroococcidiopsis than in Hydrated Counterparts after High-Dose Gamma Irradiation
Authors: Baqué Mickael , Napoli Alessandro , Fagliarone Claudia , Moeller Ralf , de Vera Jean-Pierre , Billi Daniela
Published: June 2020

Carotenoids are promising targets in our quest to search for life on Mars due to their biogenic origin and easy detection by Raman spectroscopy, especially with a 532 nm excitation thanks to resonance effects. Ionizing radiations reaching the surface and subsurface of Mars are however detrimental for the long-term preservation of biomolecules. We show here that desiccation can protect carotenoid Raman signatures in the desert cyanobacterium Chroococcidiopsis sp. CCMEE 029 even after high-dose gamma irradiation. Indeed, while the height of the carotenoids Raman peaks was considerably reduced in hydrated cells exposed to gamma irradiation, it remained stable in dried cells irradiated with the highest tested dose of 113 kGy of gamma rays, losing only 15-20% of its non-irradiated intensity. Interestingly, even though the carotenoid Raman signal of hydrated cells lost 90% of its non-irradiated intensity, it was still detectable after exposure to 113 kGy of gamma rays. These results add insights into the preservation potential and detectability limit of carotenoid-like molecules on Mars over a prolonged period of time and are crucial in supporting future missions carrying Raman spectrometers to Mars’ surface.
Improvement in the Hard Milling of AISI D2 Steel under the MQCL Condition Using Emulsion-Dispersed MoS2 Nanosheets
Authors: Dong Pham Quang , Duc Tran Minh , Tuan Ngo Minh , Long Tran The , Thanh Dang Van , Truong Nguyen Van
Published: June 2020

The present work shows the process for MoS2 nanosheet production by liquid N2-queched bulk, a novel method having highly efficient, green, and facile operation. The produced MoS2 nanoparticles are suspended in minimum quantity cooling lubrication (MQCL)-based fluid to form nanofluid used for the hard milling of AISI D2 steel. The study aims to improve the hard-milling performance assisted by the MQCL technique using MoS2 nanofluid. ANOVA analysis is used to evaluate the effects of three input machining variables, including nanoparticle concentration, cutting speed, and material hardness on cutting forces. The results indicate that the better cooling effect from the principle of the Ranque–Hilsch vortex tube of the MQCL device combined with the better lubricating performance from MoS2 nanofluid brings out the sustainable alternative solution for machining difficult-to-cut material. Moreover, the experimental results provide the technical guides for the selection of proper values of nanoparticle concentration and cutting speed while ensuring the technological, economic, and environmental characteristics.
Tribology and Dowson
Authors: Morris Nicholas , Johns-Rahnejat Patricia , Rahnejat Homer
Published: June 2020

It is with great sadness that we note the passing of Professor Duncan Dowson on 6th January 2020. Duncan was an esteemed member of the Editorial Board of this journal. He will be remembered as one of the founding fathers of tribology and as a true gentleman. He was the last living member of the Jost Committee, set up by the UK Government (1964–1966) to investigate the state of lubrication education and research, and to establish the requirements of industry in this regard [1]. This committee coined the term “tribology”.Duncan contributed to many areas of tribological research and established many of them, including elastohydrodynamic theory and biotribology.[...]
Influence of Homogenization and Solution Treatments Time on the Microstructure and Hardness of Inconel 718 Fabricated by Laser Powder Bed Fusion Process
Authors: Fayed Eslam M. , Shahriari Davood , Saadati Mohammad , Brailovski Vladimir , Jahazi Mohammad , Medraj Mamoun
Published: June 2020

In the present study, Inconel 718 (IN718) superalloy fabricated by laser powder bed fusion (LPBF) has been characterized focusing on the effect of both homogenization and solution treatment time on grains structure, crystallographic texture, precipitates formation/dissolution and material hardness. For this purpose, a heat-treatment time window with a wide range of soaking times for both treatments was established aiming to develop the optimal post-treatment conditions for laser powder bed fused IN718. It was found that the as-printed IN718 is characterized by very fine columnar/cellular dendrites with Laves phase precipitating at the grain boundaries as well as inter-dendritic regions, which differs from the microstructure of wrought and cast materials and requires special heat-treatment conditions different from the standard treatments. The results reveal that the relatively short homogenization treatment at 1080 °C for 1 h was not enough to significantly change the as-printed grain structure and completely dissolve the segregates and Laves phase. However, a completely recrystallized IN718 material and more Laves phase dissolution were obtained after homogenization treatment for 4 h. A further increase in time of the homogenization treatment (7 h) resulted in grain growth and coarsening of carbides precipitates. The solution treatment time at 980 °C did not cause noticeable changes in the crystallographic texture and grain structure. Nevertheless, the amount of δ-phase precipitation was significantly affected by the solution treatment time. After applying the heat-treatment time window, the hardness increased by 51–72% of the as-printed condition depending on the treatment time due to the formation of γ′ and γ″ in the γ-matrix. The highest material hardness was obtained after 1 h homogenization, whereas the prolonged time treatments reduced the hardness. This study provides a comprehensive investigation of the post heat-treatments of the laser powder bed fused IN718 that can result in an optimized microstructure and mechanical behavior for particular applications.
“Outsourcing” Diatoms in Fabrication of Metal-Doped 3D Biosilica
Authors: Brzozowska Weronika , Sprynskyy Myroslav , Wojtczak Izabela , Dąbek Przemysław , Witkowski Andrzej , Buszewski Bogusław
Published: June 2020

Diatoms have an ability that is unique among the unicellular photoautotrophic organisms to synthesize an intricately ornamented siliceous (biosilica) exoskeleton with an ordered, hierarchical, three-dimensional structure on a micro- to nanoscale. The unique morphological, structural, mechanical, transport, photonic, and optoelectronic properties of diatomaceous biosilica make it a desirable material for modern technologies. This review presents a summary and discussion of published research on the metabolic insertion of chemical elements with specific functional activity into diatomaceous biosilica. Included in the review is research on innovation in methods of synthesis of a new generation of functional siliceous materials, where the synthesis process is “outsourced” to intelligent microorganisms, referred to here as microtechnologists, by providing them with appropriate conditions and reagents.
Rheological Study of Phenol Formaldehyde Resole Resin Synthesized for Laminate Application
Authors: Kamarudin Nuruldiyanah , Awang Biak Dayang Radiah , Zainal Abidin Zurina , Cardona Francisco , Sapuan Salit Mohd
Published: June 2020

Heat explosions are sometimes observed during the synthesis of phenol formaldehyde (PF) resin. This scenario can be attributed to the high latent heat that was released and not dissipated leading to the occurrence of a runaway reaction. The synthesis temperature and time played important roles in controlling the heat release, hence preventing the resin from hardening during the synthesis process. This study aims to assess the rheological and viscoelasticity behaviors of the PF resin prepared using paraformaldehyde. The prepared PF resin was designed for laminate applications. The rheological behavior of the PF resin was assessed based on the different molar ratios of phenol to paraformaldehyde (P:F) mixed in the formulation. The molar ratios were set at 1.00:1.25, 1.00:1.50 and 1.00:1.75 of P to F, respectively. The rheological study was focused at specific synthesis temperatures, namely 40, 60, 80 and 100 °C. The synthesis time was observed for 240 min; changes in physical structure and viscosity of the PF resins were noted. It was observed that the viscosity values of the PF resins prepared were directly proportional to the synthesis temperature and the formaldehyde content. The PF resin also exhibited shear thickening behavior for all samples synthesized at 60 °C and above. For all PF resin samples synthesized at 60 °C and above, their viscoelasticity results indicated that the storage modulus (G′), loss modulus(G″) and tan δ are proportionally dependent on both the synthesis temperature and the formaldehyde content. Heat explosions were observed during the synthesis of PF resin at the synthesis temperature of 100 °C. This scenario can lead to possible runaway reaction which can also compromise the safety of the operators.
Removal of Barium from Solution by Natural and Iron(III) Oxide-Modified Allophane, Beidellite and Zeolite Adsorbents
Authors: Baldermann Andre , Fleischhacker Yvonne , Schmidthaler Silke , Wester Katharina , Nachtnebel Manfred , Eichinger Stefanie
Published: June 2020

Efficient capture of barium (Ba) from solution is a serious task in environmental protection and remediation. Herein, the capacity and the mechanism of Ba adsorption by natural and iron(III) oxide (FeO) modified allophane (ALO), beidellite (BEI) and zeolite (ZEO) were investigated by considering the effects of contact time, temperature, pH, Ba2+ concentration, adsorbent dosage, the presence of competitive ions and adsorption–desorption cycles (regenerability). Physicochemical and mineralogical properties of the adsorbents were characterized by XRD, FTIR, SEM with EDX and N2 physisorption techniques. The Ba2+ adsorption fitted to a pseudo-first-order reaction kinetics, where equilibrium conditions were reached within <30 min. BEI, ALO and ZEO with(out) FeO-modification yielded removal efficiencies for Ba2+ of up to 99.9%, 97% and 22% at optimum pH (pH 7.5–8.0). Adsorption isotherms fitted to the Langmuir model, which revealed the highest adsorption capacities for BEI and FeO-BEI (44.8 mg/g and 38.6 mg/g at 313 K). Preferential ion uptake followed in the order: Ba2+ > K+ > Ca2+ >> Mg2+ for all adsorbents; however, BEI and FeO-BEI showed the highest selectivity for Ba2+ among all materials tested. Barium removal from solution was governed by physical adsorption besides ion exchange, intercalation, surface complexation and precipitation, depending mainly on the absorbent type and operational conditions. BEI and FeO-BEI showed a high regenerability (>70–80% desorption efficiency after 5 cycles) and could be considered as efficient sorbent materials for wastewater clean-up.
Sensor-Assisted Assessment of the Tribological Behavior Patterns of AA7075 Hybrid MMC Reinforced with Multi-Wall Carbon Nanotubes and Pulverized Fuel Ash
Authors: Kumaran Selvaraj Senthil , Srinivasan Kathiravan , S Ramesh Kumar , Hu Yuh-Chung
Published: June 2020

In recent years, the deployment of sensors and other ancillary technologies has turned out to be vital in the investigation of tribological behavioral patterns of composites. The tribological behavioral patterns of AA7075 hybrid metal matrix composites (MMCs) reinforced with multi-wall carbon nanotubes (MWCNTs), and pulverized fuel ash (PFA) were investigated in this work. The stir casting technique was used to fabricate the composites. The mechanical properties such as tensile strength and hardness were determined for the fabricated material. Besides, microstructure analysis was performed for these AA7075 hybrid MMCs reinforced with MWCNTs and pulverized fuel ash. A pin-on-disc wear testing setup was used to evaluate the wear rate, in which the EN 31 steel disc was used as the counter-face. Taguchi’s design of the experiments was used to optimize the input parameters that impact the characteristics of the hybrid composites, and ANOVA (analysis of variance) was used to determine the contribution of input parameters on the wear behavior. Electrical discharge machining (EDM) was conducted on the AA7075 hybrid metal matrix composites using a copper electrode for determining the material removal rate. These investigations and the results were utilized for determining the optimized output process parameter values of the AA7075 metal matrix composite.