bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multitrophic diversity sustains ecological complexity by dampening top‐down control of a shallow marine benthic food web
Authors: O’Gorman Eoin J. 
Published: December 2020

AbstractBiodiversity is typically considered as a one‐dimensional metric (e.g., species richness), yet the consequences of species loss may be different depending on where extinctions occur in the food web. Here, I used a manipulative field experiment in a temperate subtidal marine system to explore the implications of diversity loss at multiple trophic levels for ecosystem functioning and food web structure. The four manipulated predators included the small painted goby and common prawn, which are also fed on by the larger black goby and shore crab. Antagonistic interactions between the manipulated predators (e.g., intraguild predation, intimidation, interference competition) limited their negative effects on the rest of the food web. Top‐down control was so suppressed at the highest level of multitrophic diversity that the resulting food webs were as complex and productive as those containing no manipulated predators. Negative interactions between the predators weakened as multitrophic diversity decreased, however, resulting in stronger consumption of lower trophic levels and a simpler food web with lower rates of two key ecosystem processes: primary production and decomposition. These results show how indirect interactions between predators on multiple trophic levels help to promote the complexity and functioning of natural systems.
Cardiovascular complications in COVID‐19 patients with or without diabetes mellitus
Authors: Abe Temidayo , Egbuche Obiora , Igwe Joseph , Jegede Opeyemi , Wagle Bivek , Olanipekun Titilope , Onwuanyi Anekwe 
Published: December 2020

AbstractIntroductionCoronavirus disease 2019 (COVID‐19) has become a major global crisis. Preliminary reports have, in general, indicated worse outcomes in diabetes mellitus (DM) patients, but the magnitude of cardiovascular (CV) complications in this subgroup has not been elucidated.MethodsWe included 142 patients admitted with laboratory‐confirmed COVID‐19 from April 1st to May 30th 2020; 71 (50%) had DM. We compared baseline demographics and study outcomes between those with or without DM using descriptive statistics. Multivariate logistic regression was used to estimate the adjusted odds ratio for the study outcomes in DM patients, compared to those without DM, stratified by age, sex and glycaemic control. CV outcomes of interest include acute myocarditis, acute heart failure, acute myocardial infarction, new‐onset atrial fibrillation and composite cardiovascular end‐point consisting of all individual outcomes above.ResultMean age was 58 years. The unadjusted rates were higher in DM patients compared to non‐diabetics for the composite cardiovascular end‐point (73.2% vs. 40.6% p < .0001), acute myocarditis (36.6% vs. 15.5% p = .004), acute heart failure (25.3% vs. 5.6% p = .001), acute myocardial infarction (9.9% vs. 1.4% p = .03) and new‐onset atrial fibrillation (12.7% vs. 1.4% p = .009). After controlling for relevant confounding variables, diabetic patients had higher odds of composite cardiovascular end‐point, acute heart failure and new‐onset atrial fibrillation.
Brønsted Acid‐Catalyzed Cyclopropanation of Indoles Using α‐Aryl‐α‐diazoacetates
Authors: Sakamoto Kenta , Ikawa Yuya , Yoshimura Tomoyuki , Matsuo Jun‐ichi 
Published: December 2020

AbstractMetal‐free cyclopropanation of N‐protected indoles with α‐aryl‐α‐diazoacetates proceeded by using a catalytic amount of triflic imide as a Brønsted acid catalyst. The use of a catalytic amount of methyl phenylacetate improved the efficiency of the Brønsted acid‐catalyzed cyclopropanation. A reaction mechanism including C‐protonation of diazoacetates with HNTf2, followed by formal [3+2] cycloaddition with indoles and 1,3‐rearrangement was proposed for the cyclopropanation.
A study on the fuzzy evaluation system of carbon dioxide flooding technology
Authors: Lu Yu , Liu Rui , Wang Kexin , Tang Yongqiang , Cao Yue 
Published: December 2020

AbstractThe research and application of carbon dioxide (CO2) flooding to improve enhanced oil recovery (EOR) technology has been carried out vigorously all over the world, because it not only helps meet the needs of oilfield development but also solve the problem of carbon sequestration. A comprehensive evaluation of the application of CO2 flooding technology is necessary. In this paper, the maximum membership degree method is used to construct a comprehensive evaluation model to evaluate the CO2 gas injection effect of the P1‐1 well group in the P city reservoir to verify the development effect of CO2 flooding. The factors that affect the effect of CO2 flooding include technology, management, and economic benefits. The final evaluation index system is obtained by decomposing the evaluation factors in the effect of CO2 flooding in the waterdrive petroleum reservoir and combining the relevant literature. The analytic hierarchy process (AHP) method is used to weight CO2 injection evaluation factors in the P1‐1 well group, and the results show that the CO2 flooding development effect is excellent; it is better in terms of the management and economic effect, but the score is not high.
A morphological investigation of marine transgression in estuaries
Authors: Townend Ian , Zhou Zeng , Guo Leicheng , Coco Giovanni 
Published: December 2020

AbstractThe landscape setting of estuaries varies widely and is an important aspect of determining how they evolve. This paper focusses on alluvial estuaries in river valleys and how they respond to sea level rise. We examine the implications of marine transgression, as a response to sea level rise, where the estuary moves upwards and landwards to maintain its position in the tidal frame (so‐called stratigraphic rollover). Here we encapsulate such kinematic movement of the estuary morphology using a ‘morphokinematic’ model, to assess the potential response to sea level rise and sediment supply. The model of the estuary form includes a single convergent channel, intertidal and surrounding floodplains (the valley) and allows the relative importance of the space available for deposition of sediments, the accommodation space, to be investigated as a function of rates of sea level rise and sediment supply. The transgression of the system is determined using a sediment mass balance, taking account of any supply from the river and marine environment. Model results confirm that the transgression distance, measured as the distance the entity moves landward, varies in proportion to the change in accommodation space, which mainly depends on the floodplain area. As the size of the floodplain reduces, the transgression distance is less and the system becomes much more sensitive to changes in the rate of sea level rise or changes in sediment supply. The greater demand for sediment when a floodplain is present results in greater cannibalization of the estuary form (i.e. greater landward movement) to meet the sediment demand. When the floodplain is disconnected from the estuary, the synergistic relationship is lost and the accommodation space increases. The capacity for restoration will depend on the availability of sediment and the prevailing rate of sea level rise.
Toward 6G: Understanding network requirements and key performance indicators
Authors: Slalmi Ahmed , Chaibi Hasna , Chehri Abdellah , Saadane Rachid , Jeon Gwanggil 
Published: December 2020

AbstractAlthough the fifth‐generation (5G) is not yet officially launched, researchers worldwide have turned to the sixth‐generation (6G) communications system. The 3G has opened the gap to fourth‐generation (4G). It will be the same for 5G, which will facilitate the path to 6G. The technology 5G provides a high‐level infrastructure enabling various technologies such as autonomous cars, artificial intelligence, drone networking, mobile broadband communication, and, most importantly, the Internet of Things (IoT) and the concept of smart cities. We are, therefore, in the middle of the fourth industrial revolution (Industry 4.0). However, as new technologies gain traction, networks become increasingly complex and difficult to pin down to keep networks operating at the level prescribed by evolving services. The ultimate goal of 6G is to move from the concept of the Internet of intelligent things to the new idea of the intelligent Internet of intelligent things. This article shows the features and tools of 6G technology that will help meet these traffic needs. Besides, we highlight the main feature of the 6G, in terms of architecture and services, scheduled as recommended by the International Telecommunications Union (ITU) in its current technical specifications and discussions on the latest research in this area.
Security challenges of Internet of Underwater Things: A systematic literature review
Authors: Yisa Aliyu Gana , Dargahi Tooska , Belguith Sana , Hammoudeh Mohammad 
Published: December 2020

AbstractWater covers approximately 71% of the earth surface, yet much of the underwater world remains unexplored due to technology limitations. Internet of Underwater Things (IoUT) is a network of underwater objects that enables monitoring subsea environment remotely. Underwater Wireless Sensor Network (UWSN) is the main enabling technology for IoUT. UWSNs are characterised by the limitations of the underlying acoustic communication medium, high energy consumption, lack of hardware resources to implement computationally intensive tasks and dynamic network topology due to node mobility. These characteristics render UNWSNs vulnerable to different attacks, such as Wormhole, Sybil, flooding, jamming, spoofing, and Denial of Service attacks. This article reviews peer‐reviewed literature that addresses the security challenges and attacks on UWSNs as well as possible mitigative solutions. Findings show that the biggest contributing factors to security threats in UWSNs are the limited energy supply, the limited communication medium and the harsh underwater communication conditions. Researchers in this field agree that the security measures of terrestrial wireless sensor networks are not directly applicable to UWSNs due to the unique nature of the underwater environment where resource management becomes a significant challenge. This article also outlines future research directions on security and privacy challenges of IoUT and UWSN.
On secure transmission in hybrid satellite‐terrestrial cooperative network with untrusted energy harvesting relay and imperfect channel estimation
Authors: Odeyemi Kehinde O. , Owolawi Pius A. , Olakanmi Oladayo O. 
Published: December 2020

AbstractIn this paper, the security performance of a hybrid satellite‐terrestrial cooperative network (HSTCN) with untrusted energy limited relay and imperfect channel state information (CSI) is investigated. The satellite and terrestrial links are assumed to follow Shadowed‐Rician fading and Rayleigh fading distributions respectively. The amplify‐and‐forward energy‐limited relay node employs power splitting relaying mode to scavenge energy from its received signals. By considering imperfect CSI between the relay and destination link, maximum ratio combining (MRC) and selection combining (SC) diversity schemes are utilized at the destination to enhance the quality of received signal‐to‐noise ratio (SNR) and aid jamming signal to prevent the untrusted relay from intercepting the satellite confidential data. Thus, to evaluate the HSTCN security performance, the exact analytical closed‐form expressions for the security outage probability (SOP) and connectivity outage probability (COP) are derived for each of the diversity combining techniques. Owing to trade‐off between SOP and COP, the effective secrecy throughput (EST) expression is obtained for the considered diversity schemes with a view to examine the security and reliability performance of the concerned system. Moreover, the impact of system parameters such as transmit SNR, channel coefficient, energy harvesting coefficient, and number of antennas are evaluated. In addition, the results reveal that the MRC has better SOP, COP, and EST performance compare with the SC. Also, it is found that the system EST degrades at high transmit SNR when the number of antennas at satellite is higher. The accuracy of the derived analytical expressions is confirmed by using Monte‐Carlo simulations.
On outage analysis of nonlinear radio frequency energy harvesting based cooperative communication in cognitive radio network
Authors: Ghosh Sutanu 
Published: December 2020

AbstractThe aim of this article is to investigate the outage performance of nonlinear radio frequency (RF) energy harvesting (EH) enabled decode‐and‐forward relay assisted cognitive radio network. Here, secondary transmitter (ST) can access the licensed spectrum of primary users (PUs) to send its message toward the secondary receiver and at the same time, it can support the primary communication by performing like a relay node. ST can harvest the energy from the received RF signal of primary transmitter to execute its necessary activities. The closed‐form expressions of PU and secondary user outage are derived to measure the end‐to‐end reliability of the system. The accuracy of derived expressions are also validated through the observation of simulation results. In addition to that, the performance of nonlinear EH model is also compared with respect to linear EH model.
Glycemic index of different varieties of yam as influenced by boiling, frying and roasting
Authors: Ampofo Deborah , Agbenorhevi Jacob K. , Firempong Caleb K. , Adu‐Kwarteng Evelyn 
Published: December 2020

AbstractYam is one of the commonly consumed carbohydrate staples. The objective of this work was to investigate the effect of boiling, roasting, and frying on the glycemic index (GI) of white yam (Dioscorea rotundata), yellow yam (Dioscorea cayenesis), and water yam (Dioscorea alata). Yam tubers were obtained (peeled, sliced, washed) deep fried in vegetable oil for 35–40 min and boiled in water for about 35–45 min. Sliced unpeeled tubers were also roasted at about 120°C for 40–45 min. The cooked yam samples were fed to 10 healthy subjects aged between 20–50 years. A glucometer was used to measure the blood glucose concentrations of the test individuals before consuming the yam diets and after the 15th, 30th, 45th, 60th, 90th, and 120th min of consumption. The average incremental area under the curves (IAUC) obtained from the recorded blood glucose concentrations were used to calculate the GI of various yam diets. The GI of the yam diets were found to be in the following increasing order: White‐yam‐boiled (44.26%) < Water‐yam‐boiled (50.12%) < White‐yam‐roasted (50.62%) < Water‐yam‐roasted (54.04%) < White‐yam‐fried (59.13%) < Yellow‐yam‐fried (65.08%) < Water‐yam‐fried (69.16%) < Yellow‐yam‐roasted (70.62%) < Yellow‐yam‐boiled (75.18%). White yam diets relatively had lower GI compared to yellow yam and water yam. Boiling was found to give generally lower GI in the white and water yams and could therefore be applied in the preparation of lower GI diets for diabetics.
“They don't think it will ever happen to them”: Exploring factors affecting participation in alcohol‐influenced aquatic activity among young Australian adults
Authors: Calverley Hannah L. M. , Petrass Lauren A. , Blitvich Jennifer D. 
Published: December 2020

AbstractIssue addressedYoung adults are over‐represented in alcohol‐related drownings in high‐income countries; however, little research has investigated their behaviours and decision‐making to inform prevention efforts.MethodsSemi‐structured interviews were conducted with 23 young Australian adults (aged 18‐24 years). Questions, informed by previous research, inquired about behavioural practices in aquatic contexts and influences on involvement in alcohol‐influenced aquatic activity. Interviews were transcribed verbatim. Thematic and interpretative phenomenological analysis followed.ResultsTwo main themes: personal and contextual awareness, and the impact of other people affected perceptions and involvement in alcohol‐influenced aquatic activity. Perceived control of situations and self‐confidence affected how these influences impacted individuals’ involvement. Participants acknowledged some young adults likely overestimate their aquatic abilities. This awareness was not discussed in relation to their own capabilities.ConclusionDrowning prevention efforts should inform young adults of the dangers of combining alcohol and aquatic activities, and make risks appear more immediate and applicable. Consideration should be given to measuring both perceived and actual aquatic abilities within various aquatic environments, to determine whether self‐reported perceived competence is an accurate proxy measure for actual aquatic ability. The influence of alcohol should also be highlighted. Steps are required for a positive shift in Australian norms of alcohol use in aquatic settings and the social and cultural attitudes towards this.So what?This study provides new insight into young adults’ perceptions and involvement in alcohol‐influenced aquatic activity. It enhances the evidence base for drowning prevention and health promotion practitioners and should inform more focused campaigns to prevent alcohol‐related drownings among young Australian adults.
A reappraisal of acute doses of benzodiazepines as a model of anterograde amnesia
Authors: Segura Isis Angélica , McGhee Jamie , Della Sala Sergio , Cowan Nelson , Pompéia Sabine 
Published: December 2020

AbstractObjectiveAcute administration of benzodiazepines is considered a pharmacological model of general organic anterograde amnesias (OAA). We sought to determine which type of amnesia these drugs best model by comparing the effects of diazepam with those reported in amnesiacs regarding working memory capacity (WMC), susceptibility to retroactive interference (RI), and accelerated forgetting.MethodsIn this double‐blind, parallel‐group design study, 30 undergraduates were randomly allocated to acute oral treatments with 15 mg diazepam or placebo. WMC and story recall were assessed pre‐ and post‐treatment. Story presentation was succeeded by 10 min of RI (spotting differences in pictures) or minimal RI (doing nothing in a darkened room). Delayed story recall was assessed under diazepam and 7 days later in a drug‐free session to assess accelerated forgetting.ResultsRecall of stories encoded under diazepam, whether reactivated or not, was severely impaired (anterograde amnesia). However, diazepam did not impair WMC, increase susceptibility to RI, or accelerate forgetting.ConclusionsDiazepam's amnestic effects mirror those in patients with probable severe medial temporal damage, mostly restricted to initial consolidation and differ from other OAA (Korsakoff syndrome, frontal, transient epileptic, posttraumatic amnesia, and most progressive amnesias) in terms of WMC, susceptibility to RI and accelerated forgetting.
Is the cost of equity a mere function of leverage? The case of bond IPOs
Authors: Al‐Khasawneh Jamal A. , Dion Paul , Essaddam Naceur , Hussain Tashfeen 
Published: December 2020

AbstractIn this paper, we investigate how undertaking a bond IPO influences a firm's cost of equity. Using a sample of nearly 600 firms that have gone through a bond IPO over the 1980–2014 period, we show that the change in the cost of equity that results is not just a function of leverage influencing the risk of residual owners. The information and monitoring environment, and agency relationships of a firm change significantly with its first public debt, and these changes can have a significant impact on the firm's cost of equity. We find that firms that have relatively high information asymmetry before they undertake the bond IPO experience less of a rise in their cost of equity than firms with relatively low information asymmetry consistent with these firms benefitting from improvements in their information environment as a result of the IPO. We also show that firms with high pre‐bond IPO free cash flow see less of an increase in their cost of equity than firms with low pre‐bond IPO free cash flow consistent with the disciplining mechanism of additional debt and the benefit from additional monitoring. In addition, we find that firms with poor corporate governance experience less of an increase in their cost of equity after the bond IPO than firms with better corporate governance. The evidence suggests that the change in the riskiness of equity after a firm goes through a bond IPO is much more complex than what is predicted by the leverage increase.
Impact of demographics and appointment characteristics on patient attendance in a university dental clinic
Authors: White Laura Jade , Butler‐Howell Kate Ellise , Nadon‐Hoysted Naomie , Schulz Madeleine Carly , Kroon Jeroen 
Published: December 2020

AbstractIntroductionFailed patient attendance in a university dental clinic is detrimental to the student learning experience, the university as a business, and to members of the public awaiting urgent dental treatment.PurposeThis study aimed to identify the demographic, appointment characteristics, and time‐related factors associated with patient attendance in a university dental clinic from 2015 to 2019.MethodsA 5‐year retrospective analysis was conducted in 2020 on data extracted from the Griffith University Dental Clinic patient management system. Following data cleaning and categorization, the dataset was downloaded into SPSS for statistical analysis. Frequencies, odds ratio, and chi squared were used to determine the demographic and time‐related factors of patients who had completed, cancelled, and failed to attend (FTA) appointments.ResultsA total of 23.4% of appointments were cancelled, and 6.6% were FTA. Demographics associated with cancellations include females, adults aged 25 to 44, and private paying patients. FTA were higher in young adults aged 19 to 24, low to mid‐range socioeconomic status (SES) and those eligible for publicly funded dental treatment. Mondays and Fridays experienced the greatest number of FTA and cancellations, respectively. Emergency appointments had the greatest attendance rates and endodontic procedures the lowest.ConclusionThe loss of clinical teaching hours, resources, and revenue necessitates the implementation of targeted strategies to minimize cancellations and FTA based on demographic and appointment characteristics that may render individual as high risk for failed attendance.