bluuebunny/crossref_metadata_2025 huggingface dataset:
Young‐adult compared to adolescent onset of regular cannabis use: A 20‐year prospective cohort study of later consequences
Authors: Chan Gary C. K. , Becker Denise , Butterworth Peter , Hines Lindsey , Coffey Carolyn , Hall Wayne , Patton George
Published: January 2021

Introduction

This paper compares consequences of cannabis use initiated after high school with those of cannabis initiation in adolescence, with estimates of the proportion of adverse consequences accounted for by adult‐onset and adolescent‐onset cannabis users.

Methods

A state‐representative sample in Victoria, Australia (n = 1792) participated in a 10‐wave longitudinal study and was followed from age 15 to 35 years. Exposure variable: Patterns of cannabis use across 20 years. Outcomes at age 35: Alcohol use, smoking, illicit drug use, relationship status, financial hardship, depression, anxiety and employment status.

Results

Substantially more participants (13.6%) initiated regular use after high school (young‐adult onset) than in adolescence (7.7%, adolescent onset). By the mid‐30s, both young‐adult and adolescent‐onset regular users were more likely than minimal/non‐users (63.5%) to have used other illicit drugs (odds ratio [OR] > 20.4), be a high‐risk alcohol drinker (OR > 3.7), smoked daily (OR > 7.2) and less likely to be in relationships (OR < 0.4). As the prevalence of the young‐adult‐onset group was nearly double of the adolescent‐onset group, it accounted for a higher proportion of adverse consequences than the adolescent‐onset group.

Discussion and Conclusions

Cannabis users who began regular use in their teens had poorer later life outcomes than non‐using peers. The larger group who began regular cannabis use after leaving high school accounted for most cannabis‐related harms in adulthood. Given the legalisation of cannabis use in an increasing number of jurisdictions, we should increasingly expect harms from cannabis use to lie in those commencing use in young adulthood.
Continuous glucose monitoring: A review of the evidence in type 1 and 2 diabetes mellitus
Authors: Lin Rose , Brown Fran , James Steven , Jones Jessica , Ekinci Elif
Published: January 2021

Context and Aim

Continuous glucose monitoring (CGM) is becoming widely accepted as an adjunct to diabetes management. Compared to standard care, CGM can provide detailed information about glycaemic variability in an internationally standardised ambulatory glucose profile, enabling more informed user and clinician decision making. We aimed to review the evidence, user experience and cost‐effectiveness of CGM.

Methods

A literature search was conducted by combining subject headings ‘CGM’ and ‘flash glucose monitoring’, with key words ‘type 1 diabetes’ and ‘type 2 diabetes’, limited to ‘1999 to current’. Further evidence was obtained from relevant references of retrieved articles.

Results

There is a strong evidence for CGM use in people with type 1 diabetes, with benefits of reduced glycated haemoglobin and hypoglycaemia, and increased time in range. While the evidence for CGM use in type 2 diabetes is less robust, similar benefits have been demonstrated. CGM can improve diabetes‐related satisfaction in people with diabetes (PWD) and parents of children with diabetes, as well as the clinician experience. However, CGM does have limitations including cost, accuracy and perceived inconvenience. Cost‐effectiveness analyses have indicated that CGM is a cost‐effective adjunct to type 1 diabetes management that is associated with reduced diabetes‐related complications and hospitalisation.

Conclusions

Continuous glucose monitoring is revolutionising diabetes management. It is a cost‐effective adjunct to diabetes management that has the potential to improve glycaemic outcomes and quality of life in PWD, especially type 1 diabetes.
Temporal trends in co‐morbidities and cardiometabolic risk factors at the time of type 2 diabetes diagnosis in the UK
Authors: Ling Joanna , Koye Digsu , Buizen Luke , Khunti Kamlesh , Montvida Olga , Paul Sanjoy K.
Published: January 2021

Aim

To evaluate temporal patterns in co‐morbidities, cardiometabolic risk factors and a high atherosclerotic cardiovascular disease (ASCVD) risk population at type 2 diabetes (T2D) diagnosis by age groups and sex.

Materials and Methods

From the UK primary care database, 248,619 people with a new diagnosis of T2D during 2005–2016 were identified. Among people without ASCVD, high ASCVD risk was defined as two or more of current smoker, grade 2+ obesity, hypertension, dyslipidaemia or microvascular disease. Cardiometabolic multimorbidity (CMM) was defined as two or more of cardiovascular disease, microvascular disease, hypertension, dyslipidaemia, grade 2+ obesity or cancer. Temporal patterns in the distribution of cardiometabolic risk factors were evaluated.

Results

While the prevalence of ASCVD was stable over time (approximately 18%), 50% were identified to have a high ASCVD risk (26% and 38% in the 18–39 and 40–49 years age groups, respectively), with an increasing trend across all age groups. Overall, 51% had CMM at diagnosis, increasing during 2005–2016 for the 18–39 years age group by 14%–17%, for the 40–49 years age group by 27%–33%, for the 50–59 years age group by 41%–50%, for the 60–69 years age group by 56%–65%, and for the 70–79 years age group by 65%–80%. People with young‐onset T2D had significantly higher HbA1c, body mass index and lipids at diagnosis (all p < .01). The proportions with an HbA1c of 7.5% or higher in the 18–39 and 40–49 years age groups were 58% and 54%, respectively, significantly and consistently higher over the last decade compared with those aged 50 years or older, with males having higher proportions of 15–26 and 10–18 percentage points, respectively, compared with females.

Conclusions

CMM and high ASCVD risk have been increasing consistently across all age groups and in both sex, in particular CMM in those aged younger than 50 years. Our findings indicate that the European Society of Cardiology–European Association for the Study of Diabetes recommendations need to change to consider people with young‐onset T2D as a high‐risk group, as recommended in the Primary Care Diabetes Europe position statement.
Oomycetes in rhizosphere soil of ornamental plants from retail nurseries in Southern Sweden
Authors: Cleary Michelle , Blomquist Mimmi , Marchand Marylise , Witzell Johanna
Published: January 2021

Trade of herbaceous and woody ornamental plants is recognized as a principal pathway for the introduction of alien plant pathogens, such as soil‐borne Phytophthora and Pythium species (oomycetes). The rhizosphere soil of container‐grown plants obtained from 13 nurseries and garden centres in southern Sweden were sampled and the presence of Phytophthora and Pythium species determined using traditional baiting and isolation. DNA sequencing of isolates revealed five Phytophthora taxa including P. cinnamomi, P. citricola s.l., P. plurivora, P. undulata and a non‐identified Phytophthora sp., as well as Phytopythium cf. citrinum and several species of Pythium. Phytophthora cinnamomi was detected on two different ornamental plants at the same nursery and is a first record of P. cinnamomi in Sweden. The survey revealed that a diversity of potentially pathogenic oomycetes is associated with ornamental plants available for sale in Sweden and emphasizes the need to recognize potential risks if these organisms get introduced in nature.
Being like others vs. being different: Wearable technology and daily practices of 50+ consumers in Russia and Finland
Authors: Morozova Daria , Gurova Olga
Published: January 2021

This is a qualitative study of consumers aged 50+ and their daily practices connected to wearable devices (smartwatches and fitness trackers). Drawing on the practice theory, we seek to uncover how participation in such practices might enhance users’ well‐being as an integral part of social sustainability. We assume that both ageing and well‐being are not pre‐given but they rather co‐evolve when users of wearables engage in situated practices. Hence, wearables such as smartwatches and fitness trackers might positively reconfigure the existing practices of consumers over 50, or even recruit them into new ones, resulting in higher well‐being and social sustainability. The phenomenon is examined in Russia and Finland, as ageing has been high on the agenda in these countries due to controversial pension and social welfare reforms. Though these countries are different in terms of possibilities (access to medical help, employment, social participation and so forth) for their ageing populations, an active ageing framework with an emphasis on individual responsibility over one’s well‐being has been gaining popularity in both Russia and Finland. This framework is compatible with the use of wearable devices that measure physical activity and basic health characteristics. Based on data elicited through 17 semi‐structured interviews with Russians and Finns aged between 50 and 73 y.o., this study suggests that engagement in practices with wearables might have a positive effect on consumers’ well‐being. This is achieved, for instance, by helping manage one’s daily tasks, reducing stigma that is sometimes attached to ageing individuals and/or boosting feeling of togetherness in social interactions that might decrease with ageing. In addition, an important difference between the two countries lies in how ageing consumers see themselves in relation to other ageing people when using a wearable: in Russia, the use of a wearable can signal one’s social distance from an “average” ageing person, while Finnish consumers regard themselves as doing what everyone of the same age does.
Dy2BaCuO5/Ba4DyCu3O9.09 S‐scheme heterojunction nanocomposite with enhanced photocatalytic and antibacterial activities
Authors: Yousefi Seyede Raheleh , Ghanbari Mojgan , Amiri Omid , Marzhoseyni Zeynab , Mehdizadeh Pourya , Hajizadeh‐Oghaz Morteza , Salavati‐Niasari Masoud
Published: January 2021

Semiconductor heterogeneous photocatalysis has been received much attention from the scientific and researchers in the last decade. The combination of two semiconductors with various energy diagram can dramatically enhance the lifetime and separation of the charge carriers, restrain photogenerated electron‐hole recombination, and considerably enhance photocatalytic performance as compared with other single or binary components. In this regard, we introduced the Dy2BaCuO5/Ba4DyCu3O9.09 nanocomposites as active photocatalysts below UV radiation. Dy2BaCuO5/Ba4DyCu3O9.09 nanocomposites were prepared by a simple hydrothermal method and applied as a catalyst to treat water containing organic pollutions and microorganisms. Dy2BaCuO5/Ba4DyCu3O9.09 nanocomposites degraded Methyl Orange (MO) about 87.0% after 120 min. In addition, these nanocomposites show antimicrobial activity against Gram‐positive species, including a pathogenic strain of Enterococcus faecalis, and Staphylococcus aureus, and a Gram‐negative species, including Klebsiella pneumonia and Escherichia coli.
Micronutrient dietary intakes and their food sources in adults: the Hellenic National Nutrition and Health Survey (HNNHS)
Authors: Mitsopoulou Anastasia Vasiliki , Magriplis Emmanuela , Michas George , Micha Renata , Chourdakis Michalis , Chrousos George P. , Roma Eleftheria , Panagiotakos Demosthenes B. , Zampelas Antonis , Karageorgou Dimitra , Bakogianni Ioanna , Dimakopoulos Ioannis , Ntouroupi Triantafyllia , Tsaniklidou Sophia‐Maria , Argyri Konstantina , Fappa Evangelia , Theodoraki Eleni‐Maria , Trichia Eirini , Sialvera Theodora‐Eirini , Varytimiadi Aggeliki , Spyreli Eleni , Koutelidakis Antonis , Karlis George , Zacharia Stauroula , Papageorgiou Anna , Dedoussis Georgios , Dimitriadis George , Manios Ioannis
Published: January 2021

Background

The present study aimed to assess micronutrient intake among Greek adults and to identify the main food sources that contribute to it.

Methods

Food consumption data from 2389 participants in the Hellenic National Nutrition and Health Survey (HNNHS), collected with 24‐h recalls, was used to calculate micronutrient intakes. Usual nutrient intake was estimated according to the National Cancer Institute method. Nutrient adequacy was estimated using the estimated average requirement (EAR) cut‐point method, when available, or adequate intake otherwise. The probability approach was used to determine iron intake adequacy in females of reproductive age. Food group contribution for each nutrient assessed was derived to identify their main food sources.

Results

Almost all individuals had vitamin D intake below EAR, whereas vitamins A, E, K and C, as well as potassium intake, were also insufficient in a considerable percentage of the population (>70% in most age groups). Calcium intake was substantially below the EAR for females aged >50 years and males >70 years; the same for magnesium in males >70 years. Furthermore, 50% of females, including those of reproductive age, had intake of folate below EAR. More than 50% of the population (to 79%) exceeded the upper tolerable limit for sodium (2300 mg day−1). Food contribution analysis revealed that most vitamins were derived from low‐quality foods (i.e. fast‐food).

Conclusions

A significant proportion of adults residing in Greece have low nutrient intake and poor food selections. These results provide guidance to public health policy makers for developing strategies to improve the dietary quality in Greece.
Resistance analysis and treatment outcomes in hepatitis C virus genotype 3‐infected patients within the Italian network VIRONET‐C
Authors: Di Maio Velia Chiara , Barbaliscia Silvia , Teti Elisabetta , Fiorentino Gianluca , Milana Martina , Paolucci Stefania , Pollicino Teresa , Morsica Giulia , Starace Mario , Bruzzone Bianca , Gennari William , Micheli Valeria , Yu La Rosa Katia , Foroghi Luca , Calvaruso Vincenza , Lenci Ilaria , Polilli Ennio , Babudieri Sergio , Aghemo Alessio , Raimondo Giovanni , Sarmati Loredana , Coppola Nicola , Pasquazzi Caterina , Baldanti Fausto , Parruti Giustino , Perno Carlo Federico , Angelico Mario , Craxì Antonio , Andreoni Massimo , Ceccherini‐Silberstein Francesca ,   HCV Virology Italian Resistance Network Group (Vironet C)
Published: January 2021

Aim

This study aimed to investigate the role of resistance‐associated substitutions (RASs) to direct‐acting‐antivirals (DAAs) in HCV genotype 3 (GT3).

Methods

Within the Italian VIRONET‐C network, a total of 539 GT3‐infected patients (417 DAA‐naïve and 135 DAA‐failures, of them, 13 at both baseline and failure) were analysed. Sanger sequencing of NS3/NS5A/NS5B was performed following home‐made protocols.

Results

The majority of patients were male (79.4%), 91.4% were injection drug users, 49.3% were cirrhotic and 13.9% were HIV co‐infected. Phylogenetic analysis classified sequences as GT3a‐b‐g‐h (98%‐0.4%‐0.2%‐1.2%) respectively.

Overall, 135 patients failed a DAA regimen: sofosbuvir (SOF)/daclatasvir (DCV) or velpatasvir (VEL)±ribavirin (RBV) (N = 91/15) and glecaprevir (G)/pibrentasvir (P) (N = 9). Moreover, 14.8% of patients were treated with suboptimal regimens for GT3: 3D ± RBV (Paritaprevir/r + Ombitasvir+Dasabuvir, N = 15), SOF + Simeprevir (SIM) (N = 1) or SOF/Ledipasvir (LDV) ± RBV (N = 4).

RAS prevalence was 15.8% in DAA‐naïve patients. At failure, 81.5% patients showed at least one RAS: 11/25 (44.0%) in NS3, 109/135 (80.7%) in NS5A, 7/111 (6.3%) in NS5B SOF‐failures. In NS5A‐failures, Y93H RAS was the most prevalent (68.5% vs 5.1% DAA‐naïve, P < .001) followed by A30K (12.7% vs 2.8% in DAA‐naïve, P < .001). Analysing baseline samples, a higher prevalence of NS5A‐RASs was observed before treatment in DAA‐failures (5/13, 38.5%) vs DAA‐naïves (61/393, 15.5%, P = .04). Regarding 228 DAA‐naïve patients with an available outcome, 93.9% achieved a SVR. Interestingly, patients with baseline Y93H and/or A30K had SVR rate of 72.2% vs 95.7% for patients without NS5A‐RASs (P = .002).

Conclusions

In this real‐life GT3 cohort, the majority of failures harboured resistant variants carrying NS5A‐RASs, the most frequent being Y93H. The presence of natural NS5A‐RASs before treatment was associated with failure. Further analyses are needed to confirm this observation, particularly for the new current regimens.
Predictors and priority of caring behaviours in intensive care units
Authors: Salimi Saleh , Tarbiat Shadi
Published: January 2021

Background

There is an increasing number of studies addressing nurses' perception of caring behaviours; however, on the issue of quality of care, it is important to understand why nurses focus more on certain elements of caring than others, and this needs to investigate influencing factors on, priorities, and predictors of caring behaviours.

Aims

The main goal of this study was to determine the predictors and priorities of nurses' caring behaviours in intensive care units to improve the quality of care and patient outcomes.

Methods

This is a cross‐sectional survey of nurses working in adult and pediatric ICUs in Iran. The participants were 470 ICU nurses from eight hospitals in Iran. Data were collected over 6 months in 2018 using the Persian version of “Caring Assessment Report Evaluation Q‐Care”; “Determinants of Nurse Caring Behaviors”; and a demographic data form.

Results

By broad descriptive and analytical analysis, thirteen items were recognized as predictors of caring behaviours. The most important individual predictors reported as "interest in the nursing profession," "moral obligation," and "job experience," respectively. The most important perceived nursing behaviours were, respectively, subscales of "accessible," "monitors/follow‐through" and "explains/facilitates."

Conclusion

The results provide insight into new and context‐specific predictors of nurses' caring behaviours. These findings suggest that nursing managers, besides selecting skilful staff for ICUs, may consider employing those of higher "interest in the nursing profession"; "moral obligation"; and "job experience." They, also, need to be aware that organizational culture, climate, and values have a great impact on the caring behaviours of nurses. This could help them to handle the complex issue of improving the quality of care more efficiently.
Dual impedance cardiography: An inexpensive and reliable method to assess arterial stiffness
Authors: Scudder Mark R. , Jennings J. Richard , DuPont Caitlin M. , Lockwood Kimberly G. , Gadagkar Shrenik H. , Best Belen , Jasti Swetha P. , Gianaros Peter J.
Published: January 2021

Pulse wave velocity (PWV) is a common measure of arterial stiffness. Non‐invasive methods to measure PWV are widely used in biomedical studies of aging and cardiovascular disease, but they are rarely used in psychophysiology. Barriers to wider use include the prohibitive costs of specialized equipment and need for trained technicians (e.g., ultrasonographers). Here, we describe an impedance cardiography method to measure PWV. By this method, impedance signals are dually collected from the thorax and calf. Combined with ensemble averaging of vascular signals, this dual impedance cardiography (d‐ICG) method allows for the measurement of aortic flow onset and the arrival time of peripheral pulse waveforms to compute PWV. In a community sample of adults (aged 19–78 years), PWV measured with d‐ICG exhibited a strong positive correlation with age. Moreover, age‐specific mean PWV values were within the normative reference intervals established by large scale studies using other techniques. PWV derived from d‐ICG exhibited high test‐retest reliability across several days, as well as excellent inter‐rater reliability. Last, PWV exhibited expected associations with known cardiovascular disease risk factors and indicators of autonomic cardiovascular control. d‐ICG is an inexpensive and reliable method to assess arterial stiffness.
Single‐cell RNA‐seq reveals mRNAs and lncRNAs important for oocytes in vitro matured in pigs
Authors: Yang Cai‐Xia , Wu Zi‐Wei , Liu Xiao‐Man , Liang Hao , Gao Zhuo‐Ran , Wang Yi , Fang Ting , Liu Yun‐Hua , Miao Yi‐Liang , Du Zhi‐Qiang
Published: January 2021

The faithful execution of molecular programme underlying oocyte maturation and meiosis is vital to generate competent haploid gametes for efficient mammalian reproduction. However, the organization and principle of molecular circuits and modules for oocyte meiosis remain obscure. Here, we employed the recently developed single‐cell RNA‐seq technique to profile the transcriptomes of germinal vesicle (GV) and metaphase II (MII) oocytes, aiming to discover the dynamic changes of mRNAs and long non‐coding RNAs (lncRNAs) during oocyte in vitro meiotic maturation. During the transition from GV to MII, total number of detected RNAs (mRNAs and lncRNAs) in oocytes decreased. Moreover, 1,807 (602 up‐ and 1,205 down‐regulated) mRNAs and 313 (177 up‐ and 136 down‐regulated) lncRNAs were significantly differentially expressed (DE), i.e., more mRNAs down‐regulated, but more lncRNAs up‐regulated. During maturation of pig oocytes, mitochondrial mRNAs were actively transcribed, eight of which (ND6, ND5, CYTB, ND1, ND2, COX1, COX2 and COX3) were significantly up‐regulated. Both DE mRNAs and targets of DE lncRNAs were enriched in multiple biological and signal pathways potentially associated with oocyte meiosis. Highly abundantly expressed mRNAs (including DNMT1, UHRF2, PCNA, ARMC1, BTG4, ASNS and SEP11) and lncRNAs were also discovered. Weighted gene co‐expression network analysis (WGCNA) revealed 20 hub mRNAs in three modules to be important for oocyte meiosis and maturation. Taken together, our findings provide insights and resources for further functional investigation of mRNAs/lncRNAs in in vitro meiotic maturation of pig oocytes.
Existence of solutions for a class of fractional difference equations at resonance
Authors: Chen Huiqin , Cui Yaqiong , Kang Shugui , Lu Youmin , Feng Wenying
Published: January 2021

We study a class of nonlinear fractional difference equations with nonlocal boundary conditions at resonance. The system is inspired by the three‐point boundary value problem for differential equations that have been extensively studied. It is also an extension to a fractional difference equation arising from real‐world applications. Converting the problem to an equivalent system corresponding to the integral operator and Green's function for differential equations, we are able to apply the coincidence degree theory for semilinear operators to obtain sufficient conditions for the existence of solutions. In addition, we prove a new property of the Gamma function and construct a family of examples to illustrate the applications of the results.
A cross‐ethnoracial comparison of objective and subjective neighborhood predictors of early adolescents' prosocial behavior
Authors: Memmott‐Elison Madison K. , Carlo Gustavo , Maiya Sahitya , Roos Joy
Published: January 2021

Although the Family Stress Model (FSM) has been widely tested, expanded conceptualizations of stressors, intervening mechanisms, and developmental outcomes from this perspective is becoming increasingly common in order to better explain the adolescent adjustment. Additionally, though extant research analyzes the utility of the FSM in African American and European–American samples, little is known about the representativeness of the FSM in Latino/a samples, and cross‐ethnoracial comparisons are scarce. The present study addresses these gaps by conducting cross‐ethnic comparisons in a modified FSM between African American, European–American, and U.S. Latino/a ethnoracial adolescents. Findings revealed that perceived neighborhood safety was indirectly associated with youth prosocial behavior through parent mental health symptoms and family conflict for African Americans, U.S. Latino/as, and European–Americans. Objective neighborhood risk predicted parent mental health symptoms but was not indirectly associated with youths' prosocial behavior. Results generally suggest that the FSM may adequately represent family processes across ethnoracial groups. The usefulness and practical implications of the FSM are discussed.
A novel HLA‐C allele, HLA‐C*14:125
Authors: Gualandris Federica , Bacis Sara , Campoli Riccardo , Castellani Laura , Falanga Anna
Published: January 2021

HLA‐C*14:125 allele is identical to HLA‐C*14:02:01:01 except for a single nonsynonymous mutation C199T.
Actividad física y calidad de vida relacionada con la salud en una comunidad académica
Authors: Barbosa Granados Sergio Humberto , Aguirre Loaiza Haney
Published: January 2021

Objetivo. Explorar las diferencias entre los niveles de actividad física (AF) ‒ligero, moderado y vigoroso‒, en función a la Calidad de Vida Relacionada con la Salud (CvRS). Método. 269 participantes (M = 25.3, DE = 1.5) entre estudiantes, docentes y administrativos de una comunidad académica de Pereira, Colombia. La AF se evaluó con el International Physical Activity Questionnaire (IPAQ) y la CvRS con el Cuestionario de Salud SF-36. Resultados. Quienes reportaron tener un nivel de AF moderado mostraron significativamente mejor vitalidad, salud mental y salud en general (p < 0.05). Mientras que aquellos con nivel de AF vigoroso promediaron más alto en salud general. Los niveles de AF moderado y vigoroso, en comparación con el ligero, presentaron mayor puntaje en la salud general y mental (p < 0.05). Conclusión. Este estudio aportó evidencia a favor de la hipótesis del vínculo entre AF y CvRS; además, reveló que aquellos con niveles de AF moderado y vigoroso presentan mejor CvRS en dimensiones de función social, vitalidad y salud general y mental. Futuros estudios deberían enfocarse en diferenciar los niveles de AF que mejor favorecen la CvRS, principalmente, en población escolar.
Experimental Study on Aerodynamic Loss and Heat Transfer for Various Squealer Tips
Authors: Jung Jin-sol , Kim Inkyom , Joo Jin Sung , Lee Sang Woo
Published: January 2021

This paper presents aerodynamic loss data for five squealer configurations of a full squealer (FS), a pressure-side squealer (PS), a suction-side squealer (SS), a camberline squealer (CS), and a full-camberline squealer (FCS) in a low-speed turbine cascade. In addition, tip thermal load data are also reported for the FS, PS, and SS tips. The results show that when h/s (tip clearance-to-span ratio) ≥ 0.96%, the mass-averaged loss for the FS tip decreases, has a minimum value, and then increases, as the squealer height (hst) increases. for h/s = 0.48%, however, the loss changes with hst/s are found to be minute. For the FS tip, the loss tends to increase, as the squealer thickness increases. Adding a camberline squealer to the FS tip is not beneficial in the loss reduction. When hst/s < 3.82% for h/s = 0.96%, the FS tip has the lowest mass-averaged loss, the SS tip has the second-lowest loss, the PS tip has higher loss compared to the SS tip, and the CS tip loss is highest, regardless of hst/s. For h/s = 0.96%, the average tip thermal load for the FS tip is lower than the PS tip one but is higher than the SS tip one. Thus, the SS tip delivers the lowest average thermal load, irrespective of hst/s.
New Analysis/Design of Generalized Discrete PI Controller via Discrete Time Delay Control for Nonlinear Systems
Authors: Reddy Suresh B.
Published: January 2021

Proportional-Integral (PI) and Proportional-Integral-Derivative (PID) controllers are among the most common schemes for control since their formulation nearly a century ago. They have been very successful in many applications, even as we have migrated from analog implementations to digital control systems. While there is rich literature for design and analysis of PI/PID controllers for linear time-invariant systems with modeled dynamics, the tools for analysis and design for nonlinear systems with unknown dynamics are limited, despite their known effectiveness. This paper extends previous observations about a form of discrete Time Delay Control’s equivalence to a generalized PI controller for more general canonical systems, with additional complimentary feedback linearization of known dynamics, as desired. In addition, sufficient conditions for Bounded Input-Bounded Output (BIBO) as well as exponential stability are developed in this paper for the form of discrete TDC that is closest to generalized discrete PI equivalent controller, for multi-input multi-output nonlinear systems, including nonaffine cases. Accordingly, design procedures are suggested for such discrete TDC, and generalized discrete PI controller for nonlinear systems.
Nonlinear Zero-Dynamics Attacks Targeting Nuclear Power Plants
Authors: Farber Jacob A. , Cole Daniel G.
Published: January 2021

A zero-dynamics attack allows an attacker to input some control action that results in zero measurable output but nonzero response of the internal states. This paper extends previous works on zero-dynamics attacks to nonlinear system dynamics. This is accomplished using invariant subspace techniques that identify the subspace on which zero dynamics exist. An iterative algorithm is presented to identify both this subspace and the resulting zero dynamics of the system. These methods are implemented on a model of a pressurizer in a nuclear power plant, which is a critical subsystem of pressurized water reactors that monitors and controls the system pressure and coolant inventory. This implementation is done by analyzing all combinations of attackable signals. These attackable signals are the set of all system inputs and outputs. From this analysis, there are eight unique combinations of attacked actuators and sensors that result in zero-dynamics attacks. These combinations are characterized by stability and damage time, where damage time is the time it takes to reach some undesirable state. The damage times range from half a day to sixteen days, depending on the number of signals the attacker has access to. These results demonstrate that the physics of the pressurizer system creates some vulnerabilities to zero-dynamics attacks. This work provides plant designers with tools to identify which subsystems are most susceptible to zero-dynamics attacks and might require additional defenses.
Dynamic Locomotion of a Lower-Limb Exoskeleton Through Virtual Constraints Based ZMP Regulation
Authors: Paredes Victor , Hereid Ayonga
Published: January 2021

Robotic lower-limb exoskeletons have the potentials to assist individuals with paraplegia to perform normal ambulatory functions and to provide exceptional health benefits. While modern-day hardware for exoskeletons is becoming more powerful, there are still significant challenges in implementing a practical exoskeleton motion control framework that helps paraplegic individuals to complete regular ambulatory tasks stably, safely, and efficiently without the use of arm-crutches. Inspired by the current development in dynamic walking controllers for a bipedal robot, this paper proposes a Hybrid Zero Dynamics (HZD) based control approach for powered lower-limb exoskeletons to achieve dynamic hand-free locomotion. Due to the unmodelled dynamics and exerted forces from the user upon the exoskeleton, the model-based approaches such as Hybrid Zero Dynamics struggles when implementing on the actual hardware. In this paper, we systematically formulate a virtual-constraints-based regulation framework in order to robustly stabilize the system around a stable periodic gait within the HZD framework. This regulator is then used to regulate the zero moment point (ZMP) to improve the lateral stability of the bipedal robot by indirectly regulating the center of mass (CoM) position of the exoskeleton due to the lack of available force sensors at the bottom of the feet. The proposed approach presents a general structure with which the virtual constraints can be heuristically regulated to satisfy the stability condition imposed by the ZMP criteria without compromising the hybrid invariance of the walking gaits. The effectiveness of the regulators was demonstrated through stable walking of a powered lower-limb exoskeleton in simulation and experimentation.
Experimental and Analytical Decentralized Adaptive Control of a 7-DOF Robot Manipulator
Authors: Bertino Alexander , Naseradinmousavi Peiman , Kelkar Atul
Published: January 2021

In this paper, we study the analytical and experimental control of a 7-DOF robot manipulator. A model-free decentralized adaptive control strategy is presented for the tracking control of the manipulator. The problem formulation and experimental results demonstrate the computational efficiency and simplicity of the proposed method. The results presented here are one of the first known experiments on a redundant 7-DOF robot. The efficacy of the adaptive decentralized controller is demonstrated experimentally by using the Baxter robot to track a desired trajectory. Simulation and experimental results clearly demonstrate the versatility, tracking performance, and computational efficiency of this method.
Effect of Additional Weight on Human Squat Exercise Stability: Ground Reaction Forces and Centers of Pressure
Authors: Galarza Jose , Caruntu Dumitru I.
Published: January 2021

The main focus of this work is to investigate the effect of weight on the stability of human squat exercise. The squat exercise is a common daily activity. Experiments are conducted using one human subject. A VICON motion analysis system integrated with Force Plates is utilized for these experiments. An experimental protocol is developed and followed. This work analyzes the time series of the normal component of the ground reaction forces and each coordinate of the center of pressure. These time series are used to estimate the Lyapunov Exponents using Rosenstein method. MATLAB software package is used for this investigation. The results of this work are compared with results from literature. Present work gives more information relating the safety of the squat exercise when adding additional weight. One can see that the effect of additional weight on stability depends on its value. In the cases of small and moderate additional weight the stability is the same or increases, while for the largest additional weight the investigated stability decreases.
Bearing-Only Localization of a Quasi-Static Sound Source With a Binaural Microphone Array
Authors: Bradley Aidan J. , Shirazi Masoud J. , Abaid Nicole
Published: January 2021

Sound source localization is the ability to successfully understand the bearing and distance of a sound in space. The challenge of sound source localization has been a major are of research for engineers, especially those studying robotics, for decades. One of the main topics of focus is the ability for robots to track objects, human voices, or other robots robustly and accurately. Common ways to accomplish this goal may use large arrays, computationally intensive machine learning methods, or known dynamic models of a system which may not always be available. We seek to simplify this problem using a minimal amount of inexpensive equipment alongside a Bayesian estimator, capable of localizing an emitter using easily available a-priori information and timing data received from a prototype binaural sensor. We perform an experiment in a full anechoic chamber with a sound source moving at a constant speed; this experimental environment provides a space that allows us to isolate the performance of the sensor. We find that, while our current system isn’t perfect, it is able to track the general motion of a sound source and the path to even more accurate tracking in the future is clear.
Benchmarking Fuel Economy of Connected and Automated Vehicles in Real World Driving Conditions via Monte Carlo Simulation
Authors: Rajakumar Deshpande Shreshta , Gupta Shobhit , Kibalama Dennis , Pivaro Nicola , Canova Marcello
Published: January 2021

Connectivity and automation have accelerated the development of algorithms that use route and real-time traffic information for improving energy efficiency. The evaluation of such benefits, however, requires establishing a reliable baseline that is representative of a real-world driving environment. In this context, virtual driver models are generally adopted to predict the vehicle speed based on route data and presence of lead vehicles, in a way that mimics the response of human drivers.

This paper proposes an Enhanced Driver Model (EDM) that forecasts the human response when driving in urban conditions, considering the effects of Signal Phasing and Timing (SPaT) by introducing the concept of Line-of-Sight (LoS). The model was validated against data collected on an instrumented vehicle driven on public roads by different human subjects.

Using this model, a Monte Carlo simulation is conducted to determine the statistical distribution of fuel consumption and travel time on a given route, varying driver behavior (aggressiveness), traffic conditions and SPaT. This allows one to quantify the impact of uncertainties associated to real-world driving in fuel economy estimates.
Monolithic Leg Design With Compliant Knee Joint for Bipedal Robots: Design and Preliminary Results
Authors: Rouse Ciaphus , Warnix Trevor , Garcia Martin , Tekes Ayse
Published: January 2021

Design and control of human-like robots mimicking the motion using biped legs are still in demand. However, the vast majority of the biped robots are too heavy due to the number of actuators and their bulky design. Compliant designs can mimic the motions in nature through the large deformation of their compliant members and have the ability to be designed as a single piece thereby reducing the overall weight and increasing the performance of the mechanism. Biped robots specifically designed for walking currently existing in the literature often arranged in series form. Although serial design leads high flexibility, each link carries its actuator compromising the overall weight and stability. This paper presents the design and development of a bioinspired leg for biped robots without the requirement of actuation of the knee or addition of a spring element. Each leg is designed as a single piece by exploiting a compliant knee joint, 3D printed using TPU filament and actuated through a cam design using a servo motor. Servo motor is also attached to the trunk which serves as the torso of the robot body. Zero moment point (ZMP) analysis is performed by adopting simple cart-table and inverted pendulum methods. Stiffness of the compliant knee is obtained from multibody dynamic simulations in MSC Adams. The preliminary testing of the bio-inspired biped robot reveals that the robot performs successful periodic gait.
Robust Iterative Learning Control for Interval Linear Systems
Authors: Mishra Kirti D. , Srinivasan K.
Published: January 2021

Many forms of system uncertainty result in interval description of linear systems, and numerically efficient design methods for the computation of robust iterative learning controllers with good learning transients for these systems are lacking. Using a Lyapunov framework, two design procedures that ensure robust convergence of the tracking error to zero with good learning transients are described in this study. Both methods are validated numerically for an application of position control, and robust and monotonic convergence of the tracking error to zero is demonstrated.
Switched Control Barrier Function With Applications to Vehicle Safety Control
Authors: Huang Yiwen , Chen Yan
Published: January 2021

For safety-critical systems, the safety constraints are required to be satisfied through control design. To describe and apply system safety constraints, controlled invariant set (CIS) and control barrier function (CBF) are effective methods. In many applications, safety constraints may change dynamicly in operation environment and thus are not always continuous. However, such discontinuity and switching problems of CIS and CBF were well-addressed in the literature. In this paper, to tackle the issues, novel definitions of switched CIS (SCIS) and switched CBF (SCBF) are proposed. To address the undifferentiability issue in SCBF, a novel relaxation function that connects different SCISs is proposed. Sufficient conditions for selecting the relaxation function are proposed with a rigorous proof. In the application of vehicle safety control for an obstacle avoidance problem, a relaxation function is selected and demonstrated in the safety control design. To evaluate the effectiveness of the proposed definitions and control design, simulation results are presented and discussed.
Towards Explainable Co-Robots: Developing Confidence-Based Shared Control Paradigms
Authors: Saraphis Daniel , Izadi Vahid , Ghasemi Amirhossein
Published: January 2021

In this paper, we aim to develop a shared control framework wherein the control authority is dynamically allocated between the human operator and the automation system. To this end, we have defined a shared control paradigm wherein the blending mechanism uses the confidence between a human and co-robot to allocate the control authority. To capture the confidence between the human and robot, qualitatively, a simple-but-generic model is presented wherein the confidence of human-to-robot and robot-to-human is a function of the human’s performance and robot’s performance. The computed confidence will then be used to adjust the level of autonomy between the two agents dynamically. To validate our novel framework, we propose case studies in which the steering control of a semi-automated system is shared between the human and onboard automation systems. The numerical simulations demonstrate the effectiveness of the proposed shared control paradigms.
An Integrated Hardware and Software Platform for Control of Automatic Ground Vehicles
Authors: Chu Jian , Bakshi Soovadeep , Qin Hansen , Yan Zeyu , Chen Dongmei
Published: January 2021

With the development of factory automation, intelligent manufacturing system technology, and three-dimensional automated warehouses, an automatic ground vehicle (AGV) became an essential part of controlling the discrete logistics management system within a facility. The scope of the AGV application and technical capability have been rapidly developed in recent years. However, it is highly time-consuming and resource-intensive to develop a comprehensive AGV platform in both industrial setting and academic environment to design and control of an AGV system. This paper introduces a platform for conducting AGV research and deployment, which consists of the hardware prototyping and entire software system development. By using this platform, users can readily develop customized AGV systems or verify their self-developed algorithms.
Geochemical evidence of tropical cyclone controls on shallow-marine sedimentation (Pliocene, Taiwan)
Authors: Dashtgard Shahin E. , Löwemark Ludvig , Wang Pei-Ling , Setiaji Romy A. , Vaucher Romain
Published: January 2021

Shallow-marine sediment typically contains a mix of marine and terrestrial organic material (OM). Most terrestrial OM enters the ocean through rivers, and marine OM is incorporated into the sediment through both suspension settling of marine plankton and sediment reworking by tides and waves under fair-weather conditions. River-derived terrestrial OM is delivered year-round, although sediment and OM delivery from rivers is typically highest during extreme weather events that impact river catchments. In Taiwan, tropical cyclones (TCs) are the dominant extreme weather event, and 75% of all sediment delivered to the surrounding ocean occurs during TCs. Distinguishing between sediment deposited during TCs and that redistributed by tides and waves during fair-weather conditions can be approximated using δ13Corg values and C:N ratios of OM. Lower Pliocene shallow-marine sedimentary strata in the Western Foreland Basin of Taiwan rarely exhibit physical evidence of storm-dominated deposition. Instead they comprise completely bioturbated intervals that transition upward into strata dominated by tidally generated sedimentary structures, indicating extensive sediment reworking under fair-weather conditions. However, these strata contain OM that is effectively 100% terrestrial OM in sediment that accumulated in estimated water depths <35 m. The overwhelming contribution of terrestrially sourced OM is attributed to the dominance of TCs on sedimentation, whereby ∼600,000 TCs are estimated to have impacted Taiwan during accumulation of the succession. In contrast, the virtual absence of marine OM indicates that organic contributions from suspension settling of marine OM is negligible regardless of the preserved evidence of extensive reworking under fair-weather conditions. These data suggest that (1) even in the absence of physical expressions of storm deposition, TCs still completely dominate sedimentation in shallow-marine environments, and (2) the organic geochemical signal of preserved shallow-marine strata is not reflective of day-to-day depositional conditions in the environment.
Recognition of a Middle–Late Jurassic arc-related porphyry copper belt along the southeast China coast: Geological characteristics and metallogenic implications
Authors: Mao Jingwen , Zheng Wei , Xie Guiqing , Lehmann Bernd , Goldfarb Richard
Published: January 2021

Recent exploration has led to definition of a Middle–Late Jurassic copper belt with an extent of ∼2000 km along the southeast China coast. The 171–153 Ma magmatic-hydrothermal copper systems consist of porphyry, skarn, and vein-style deposits. These systems developed along several northeast-trending transpressive fault zones formed at the margins of Jurassic volcanic basins, although the world-class 171 Ma Dexing porphyry copper system was controlled by a major reactivated Neoproterozoic suture zone in the South China block. The southeast China coastal porphyry belt is parallel to the northeast-trending, temporally overlapping, 165–150 Ma tin-tungsten province, which developed in the Nanling region in a back-arc transtensional setting several hundred kilometers inboard. A new geodynamic-metallogenic model linking the two parallel belts is proposed, which is similar to that characterizing the Cenozoic metallogenic evolution of the Central Andes.
Supplemental Material: Progressive spatial and temporal evolution of tectonic triggers and metasomatized mantle lithosphere sources for orogenic gold mineralization in a Triassic convergent margin: Kunlun-Qinling Orogen, central China
Authors: Zhao Hesen , Wang Qingfei , al. et
Published: January 2021

Figures of deposit geology and ore assemblages and the compiled ages and isotopes in the East Kunlun-West Qinling Orogen, China.
Nocardia beijingensislung mass in an immunocompetent adult
Authors: Raslan Rasha , Bailey Pamela , Sastry Sangeeta
Published: January 2021

A 47-year-old man was referred for ongoing workup of an enlarging lung mass. Extensive workup of the mass had been unrevealing for several months until cultures grewNocardia beijingensis. He was successfully treated with trimethoprim/sulfamethoxazole and then doxycycline with near-complete resolution of the mass on follow-up. This case presents a rare species ofN. beijingensis. It highlights the importance of considering nocardiosis in immunocompetent adults and the challenge in initiating targeted treatment due to delayed culture results.
Gastrointestinal dysmotility in a patient with advanced lung cancer: paraneoplastic or drug-induced?
Authors: Dias Raphael Figuiredo , Diniz Mirella Monique Lana , Santos Bruno Campos , Nobre Vandack Alencar
Published: January 2021

A 75-year-old man was hospitalised for bronchoscopy with biopsy due to a suspicious pulmonary mass at chest tomography. He had significant dyspnoea, constipation, nausea, vomiting, anorexia and a 33% loss of weight in the past 3 months. Biopsy revealed a pulmonary squamous cell carcinoma, which was inoperable. Tramadol used at home for 3 months was replaced by morphine on admission. The patient remained constipated despite prokinetics and laxatives, leading to the diagnostic hypothesis of paraneoplastic motility disorder and opioid-induced constipation. Abdominal tomography ruled out the possibility of mechanical obstruction. As complications, the patient presented superior vena cava syndrome and opioid (morphine) intoxication. The patient died a few days later. The management of this case highlights the importance of multidisciplinary care and the challenges of palliative oncology care. Paraneoplastic motility disorder must always be considered among the mechanisms of intestinal dysfunction in patients with advanced oncological disease.