bluuebunny/crossref_metadata_2025 huggingface dataset:
Convergence in voice fundamental frequency during synchronous speech
Authors: Bradshaw Abigail , McGettigan Carolyn
Published: May 2021

Joint speech behaviours where speakers produce speech in unison are found in a variety of everyday settings, and have clinical relevance as a temporary fluency-enhancing technique for people who stutter. It is currently unknown whether such synchronisation of speech timing among two speakers is also accompanied by alignment in their vocal characteristics, for example in acoustic measures such as pitch. The current study investigated this by testing whether convergence in voice fundamental frequency (F0) between speakers could be demonstrated during synchronous speech. Sixty participants across two online experiments were audio recorded whilst reading a series of sentences, first on their own, and then in synchrony with another speaker (the accompanist) in a number of between-subject conditions. Experiment 1 demonstrated significant convergence in participants’ F0 to a pre-recorded accompanist voice, in the form of both upward (high F0 accompanist condition) and downward (low and extra-low F0 accompanist conditions) changes in F0. Experiment 2 demonstrated that such convergence was not seen during a visual synchronous speech condition, in which participants spoke in synchrony with silent video recordings of the accompanist. An audiovisual condition in which participants were able to both see and hear the accompanist in pre-recorded videos did not result in greater convergence in F0 compared to synchronisation with the pre-recorded voice alone. These findings suggest the need for models of speech motor control to incorporate interactions between self- and other-speech feedback during speech production, and suggest a novel hypothesis for the mechanisms underlying the fluency-enhancing effects of synchronous speech in people who stutter.
Modeling speech act development in early childhood: the role of frequency and linguistic cues
Authors: Nikolaus Mitja , Maes Juliette , Fourtassi Abdellah
Published: May 2021

A crucial step in children’s language development is the mastery of how to use language in context. This involves the ability to recognize and use major categories of speech acts (e.g., learning that a “question” is different from a “request”). The current work provides a quantitative account of speech acts’ emergence in the wild. Using a longitudinal corpus of child-caregiver conversations annotated for speech acts (Snow et al., 1996), we introduced two complementary measures of learning based on both children’s production and comprehension. We also tested two predictors of learning based on the input frequency and the speech acts’ quality of linguistic cues. We found that children’s developmental trajectory differed largely between production and comprehension. In addition, development in both of these dimensions was not explained with the same predictors (e.g., frequency in the child-directed speech was predictive of production, but not of comprehension). The broader impact of this work is to provide a computational framework for the study of communicative development where both measures and predictors of children’s pragmatic development can be tested and compared.
What is a Minimal Clinically Important Difference for Clinical Trials in Patients with Disorders of Consciousness? A novel probabilistic approach
Authors: Monti Martin M , Spivak Norman M , Edlow Brian L , Bodien Yelena G
Published: May 2021

Over the last 30 years, there has been a growing trend in clinical trials towards assessing novel interventions not only against the benchmark of statistical significance, but also with respect to whether they lead to clinically meaningful changes for patients. In the context of Disorders of Consciousness (DOC), despite a growing landscape of experimental interventions, there is no agreed standard as to what counts as a minimal clinically important difference (MCID). In part, this issue springs from the fact that, by definition, DOC patients are either unresponsive (i.e., in a Vegetative State; VS) or non-communicative (i.e., in a Minimally Conscious State; MCS), which renders it impossible to assess any subjective perception of benefit, one of the two core aspects of MCIDs. Here, we develop a novel approach that leverages published, international diagnostic guidelines to establish a probability-based minimal clinically important difference (pMCID), and we apply it to the most validated and frequently used scale in DOC: the Coma Recovery Scale – Revised (CRS-R). This novel method is objective (i.e., based on published criteria for patient diagnosis) and easy to recalculate as the field refines its agreed criteria for diagnosis. We believe this new approach can help clinicians determine whether observed changes in patients' behavior are clinically important, even when patients cannot communicate their experiences, and can align the landscape of clinical trials in DOC with the practices in other medical fields.
Loneliness in Older People and COVID-19: Applying the Social Identity Approach to Digital Intervention Design
Authors: Stuart Avelie , Katz Dmitri , Stevenson Clifford , Gooch Daniel , Harkin Lydia , Bennasar Mohamed , Sanderson Lisa , Liddle Jacki , Bennaceur Amel , Levine Mark , Mehta Vikram , Wijesundara Akshika , Talbot Catherine V. , Bandara Arosha , Price Blaine , Nuseibeh Bashar
Published: May 2021

The COVID-19 pandemic is worsening loneliness for many older people through the challenges it poses in engaging with their social worlds. Digital technology has been offered as a potential aid, however, many popular digital tools have not been designed to address the needs of older adults during times of limited contact. We propose that the Social Identity Model of Identity Change (SIMIC) could be a foundation for digital loneliness interventions. While SIMIC is a well-established approach for maintaining wellbeing during life transitions, it has not been rigorously applied to digital interventions. There are known challenges to integrating psychological theory in the design of digital technology to enable efficacy, technology acceptance, and continued use. The interdisciplinary field of Human Computer Interaction has a history of drawing on models originating from psychology to improve the design of digital technology and to design technologies in an appropriate manner. Drawing on key lessons from this literature, we consolidate research and design guidelines for multidisciplinary research applying psychological theory such as SIMIC to digital social interventions for loneliness.
Exploring associations between diurnal cortisol, stress, coping and psychopathology in adolescents and young adults with 22q11.2 deletion syndrome
Authors: Ilen Laura , Feller Clémence Mathilde , Eliez Stephan , Micol Eva , Delavari Farnaz , Sandi Carmen , Zanoletti Olivia , Schneider Maude
Published: May 2021

Background 22q11.2 deletion syndrome (22q11DS) is a neurogenetic condition associated to a high risk for psychiatric disorders, including psychosis. Individuals with 22q11DS are thought to experience increased levels of chronic stress, which could lead to alterations in hypothalamic-pituitary-adrenocortical (HPA)-axis functioning. In the current study, we investigated for the first time diurnal salivary cortisol profiles in adolescents and young adults with 22q11DS as well as their link with stress exposure, coping strategies and psychopathology, including psychotic symptoms. Methods Salivary cortisol was collected from adolescents and young adults with 22q11DS (n = 30, age = 19.7) and matched healthy controls (HC; n = 36, age = 18.5) six times a day for two days. Exposure to stressful life events, including peer victimization, coping strategies and general psychopathology were assessed with questionnaires. Psychotic symptoms and psychiatric comorbidities were evaluated with clinical interviews.Results We observed similar daily levels and diurnal profiles of salivary cortisol in adolescents and young adults with 22q11DS compared to HCs. However, participants with 22q11DS reported less frequent exposure to stress than HCs. In 22q11DS, we observed a significant association between the use of non-adaptive coping strategies and the severity of psychotic symptoms. Cortisol level was not associated to severity of psychotic symptoms, but elevated cortisol awakening response (CAR) was found in participants with 22q11DS with higher levels of general psychopathology. Conclusions Our results do not support earlier propositions of altered HPA-axis functioning in 22q11DS but highlight the need to further investigate diurnal cortisol as an indicator of HPA-axis functioning and its link with (earlier) stress exposure and psychopathology in this population. Interventions should target the development of adaptive coping skills in preventing psychosis in 22q11DS.
Compositional generalization in multi-armed bandits
Authors: Saanum Tankred , Schulz Eric , Speekenbrink Maarten
Published: May 2021

To what extent do human reward learning and decision-making rely on the ability to represent and generate richly structured relationships between options? We provide evidence that structure learning and the principle of compositionality play crucial roles in human reinforcement learning. In a new multi-armed bandit paradigm, we found evidence that participants are able to learn representations of different reward structures and combine them to make correct generalizations about options in novel contexts. Moreover, we found substantial evidence that participants transferred knowledge of simpler reward structures to make compositional generalizations about rewards in complex contexts. This allowed participants to accumulate more rewards earlier, and to explore less whenever such knowledge transfer was possible. We also provide a computational model which is able to generalize and compose knowledge for complex reward structures. This model describes participant behaviour in the compositional generalization task better than various other models of decision-making and transfer learning.
Comparing visual memories to similar visual inputs risks lasting memory distortion
Authors: Saito Joseph M. , Duncan Katherine , Fukuda Keisuke
Published: May 2021

Maintaining perceptual experiences in visual working memory (VWM) allows us to flexibly accomplish various tasks, but some tasks come at a price. For example, comparing VWM representations to novel perceptual inputs can induce inadvertent memory distortions. If these distortions can persist, they may explain why everyday memories often become unreliable after people perform perceptual comparisons (e.g., eyewitness testimony). Here, we conducted two experiments to assess the consequences of perceptual comparisons using real-world objects that were temporarily maintained in VWM (n = 32) or recalled from visual long-term memory back into VWM (n = 30). In each experiment, young adults reported systematic memory distortions following perceptual comparisons. These distortions increased in magnitude with the delay between encoding and comparisons and were preserved when memories were retrieved again a day later. These findings suggest that perceptual comparisons play a mechanistic role in everyday memory distortions, including situations where memory accuracy is vital.
Exploring Diffusion Characteristics that Influence Serious Games Adoption Decisions
Authors: Antonopoulou Katerina , Dacre Nicholas
Published: May 2021

In this paper we discuss the diffusion of serious games and present reasons for why Rogers’ traditional approach is limited in this context. We present an alternative overview through the characteristics of relative advantage, compatibility, complexity, trialability, and observability, that reflect on the adoption decision and contributes on the commercialization of serious games.
Divergent Trends of Lifespan Variation During Mortality Crises
Authors: Vigezzi Serena , Aburto José Manuel , Permanyer Iñaki , Zarulli Virginia
Published: May 2021

Lifespan variation has been attracting increasingly greater attention as a measure of population health and mortality. Several studies have analysed periods of steady mortality decline, highlighting a strong inverse relationship between lifespan variation and life expectancy. Recent research has found that this association weakens, and even reverses, when mortality does not improve equally over age. However, to date no study has comprehensively explored the behaviour of lifespan variation when mortality increases significantly. Analysing three epidemics and two famines in Europe from the eighteenth to the twentieth centuries, we find that, during these events, relative lifespan variation increases, while absolute variation declines, and that subsequently both quickly revert to pre-crisis levels. Using decomposition techniques, we show that mortality at older ages leads to a temporary increase in absolute – but not relative – variation. Moreover, female lifespan variation is less affected by the crises than that of males, because of the higher impact of infant and child mortality on male lifespan variation. By underlining different trends of lifespan variation by sex and indicator, we offer new insight into the consequences of mortality crises. Contrary to what is often asserted, we also show that the choice of lifespan variation indicator is not always inconsequential.
Clinical and laboratory differences and role of gene xpert in tuberculous pleural effusion
Authors: Shah Manoj Kumar , Baral Sushil , Bhattarai Tulsi
Published: May 2021

Background: The diagnosis of pleural effusion and its cause are essential for pleural fluid analysis. We have evaluated clinical and laboratory differences among the tubercular pleural effusion.

Methods: The cross-sectional, observational hospital based study was conducted in Bir hospital, Nepal. All patients were evaluated by clinically and laboratory investigations. Patients enrolled for study have pleural effusion and pleural fluid analysis indicative of an exudative pleural effusion using lights criteria. The criteria of enrollment of the patients were pleural fluid for Adenosine deaminizes value more than 40 IU/L, positive for gene xpert test and pleural effusion of any cases with sputum positive pulmonary tuberculosis. Patients were divided into two groups lymphocytic and neutrophilic predominant pleural effusion.

Results: Among 100 patients with diagnosis of exudative tubercular pleural effusion, the most common symptom was pleuritic chest pain in 85%, followed by fever in 84% and cough in 82%. Among the tubercular pleural effusion, 21% had neutrophils predominant and 79% had Lymphocytes predominant. The patients with neutrophil predominant Tubercular pleural effusion had higher fever rates (90.5vs.82.5%) than those with lymphocyte-predominant Tubercular pleural effusion. The mean value of Neutrophil predominant pleural fluid for lactate dehydrogenase (LDH) level was 1657.5 IU/L and protein was 5.3gm/dl and in lymphocyte predominant pleural fluid for LDH value was 610.2 IU/L and protein was 4.6 gm/dl; the difference was statistically significant with P value of <0.001. Only 15% of patients had sputum positive for Acid fast bacilli. Among the sputum positive patients, 47% had positive for pleural fluid for gene xpert test with all patients had rifampicin sensitive. The sensitivity of pleural fluid for gene xpert test was 46.6%, and specificity was 90%.

Conclusion: In pleural effusion, the positivity of gene xpert for pleural fluid was higher among the sputum positive patients. The prevalence of Neutrophil-predominant pleural effusion was common in tubercular pleural effusion.
Awareness regarding organ transplantation among visitors of the ICU patients in three tertiary care centres in Kathmandu, a cross-sectional study
Authors: Shrestha Gentle S. , Bhattarai Amit S , Yonjen Tseten , Bhandari Ramesh S , Lakhey Paleswan J , Acharya Subhash P , Singh Shreejana , Marhatta Moda N
Published: May 2021

Background and aims: Organ transplant is often the only viable treatment option for various end stage organ failures. Inadequacy of organ procurement from living as well as cadaveric donors is common, more so in developing countries. The aim of this study was to find out the knowledge and attitude regarding organ transplantation.

Methods: A questionnaire-based survey was carried out among 150 respondents, who were the visitors of patients admitted to ICU of three tertiary care centres in Kathmandu.

Results: Majority of the respondents were male 105 (70%) and 132 (88%) were aware about organ transplant. Likewise, 111 respondents (84.1%) hold the belief that organ transplant save lives. Ninety-four of the responses (34.8%) believe that media was the source of knowledge and 121 (91.7 %) of the respondents stated that organ transplant should be promoted. Majority of them, 80 of the total respondents (60.6%) believed that organ can be donated by both living and deceased donors and 111 (84.1%) of them believed that organ transplant save lives. While 88 of the respondents (66.7%) have heard about brain death, 60 of them (45.4%) believe that there is an organ transplant act in Nepal. Out of all respondents who are aware about transplantation, 91 of them (68.9%) have opinion that they are willing to donate the organ of their beloved ones should there be a situation of brain death.

Conclusions: The study concludes that respondents have adequate knowledge regarding organ transplantation. Respondents have overall positive attitude towards organ donation and transplantation.
Association between lipid indices and 10-year cardiovascular risk of a cohort of black Africans living with type 2 diabetes mellitus
Authors: Azeez Taoreed Adegoke
Published: May 2021

Introduction Diabetes mellitus is an established cardiovascular risk factor. Diabetes mellitus impairs lipid metabolism and enhances atherosclerosis development. Absolute lipid parameter are inadequate in predicting cardiovascular risk and some lipid indices have been reported to circumvent this deficiency. The objective of the study was to determine the association between these lipid indices and 10-year cardiovascular risk among black Africans with diabetes.

Methods Seventy individuals (35 males and 35 females) living with diabetes who attended the diabetes clinic of a referral hospital in South-western Nigeria were recruited to the study. Ethical approval and participants’ informed consent were duly obtained. Fasting plasma glucose, fasting lipid profile and glycated haemoglobin were done using appropriate laboratory techniques. Atherogenic index of plasma, atherogenic coefficient, Castelli’s risk index I, Castelli’s risk index II and CHOLindex were calculated using appropriate formulae. QRISK 3 score was obtained using a validated calculator. The association between QRISK 3 and the lipid indices was determined using Pearson’s correlation.

Results The mean age of the participants was 53.34 ± 9.57 years. The mean duration of diabetes mellitus among the participants was 6.29 ± 2.78 years. The mean HbA1c and FPG were 6.98±0.72% and 6.32±0.87 mmol/L respectively. The mean QRISK 3 score was 7.58±4.80. There was a statistically significant and positive correlation between QRISK 3 score and AIP, AC, CR I and CR II. CHOLindex did not significantly correlate with QRISK 3 score.

Conclusion Among black Africans with diabetes, lipid indices (AIP, AC, CR I and CR II) significantly correlated with QRISK 3 score and therefore may be used as cheap markers of 10-year cardiovascular risk in these individuals.
COVID-19: Vaccine and antimicrobial resistance what are the global implications?
Authors: Robinson Jared , Leclézio Alexandra , Banerjee Indrajit
Published: May 2021

Antimicrobial resistance is a worldwide and highly quantified risk to global health and is more prevalent than resistance developed in vaccines as both antimicrobial resistance and vaccine resistance develop in different settings and because of alternate mechanisms. Vaccines act as a preventative measure and allow the immune system to kill any pathogen in the initial phases when the load is relatively low. This circumvents the replication of the pathogen and thus prevents the formation of mutations and furthermore resistance which is attributed to those mutations. Mutations in the target and or binding sites of a said therapeutic regime confer resistance more often in antimicrobials than they do vaccines.

The alteration of a vaccines binding site does not confer resistance as a vaccine produces a wide spectrum of antibodies due to multiple epitopes on the said antigen, the remaining antibodies are thus still protective. In antimicrobials however, the drug targets a specific site and is not dynamic and thus if a mutation of the site arises, the drug efficacy is reduced.

Although vaccine resistance is less quantified it may also pose a substantial risk to Global health as currently evident with the COVID-19 pandemic. The current global pandemic caused by SARS-CoV-2 has developed a host of mutations which are displaying a degree of resistance and reduced efficacy to the vaccines. This reduced efficacy and resistance of the mutations to current vaccination programmes, poses a risk to global health. It is vital for new vaccines to be synthesized to specifically be active against the variants. It is likely that the synthesis and development of new vaccines to counter new variants as they arise will be an ongoing process. It is evident in future that new vaccines to the mutations in COVID-19 may have to be developed as they are for the seasonal influenzae virus.
Analytical Solution for Advection-Dispersion Equation of the Pollutant Concentration using Laplace Transformation
Authors: Paudel Keshav , Bhandari Prem Sagar , Kafle Jeevan
Published: May 2021

We present simple analytical solution for the unsteady advection-dispersion equation describing the pollutant concentration C(x; t) in one dimension. In this model the water velocity in the x-direction is taken as a linear function of x and dispersion coefficient D as zero. In this paper by taking k = 0, k is the half saturated oxygen demand concentration for pollutant decay, we can apply the Laplace transformation and obtain the solution. The variation of C(x; t) with different times t upto t → ∞ (the steady state case) is taken into account advection-dispersion equation in our study.
O papel da liderança na criação e compartilhamento de conhecimento organizacional
Authors: Sordi Victor Fraile , Nakayama Marina Keiko , Cunha Cristiano José Castro de Almeida
Published: May 2021

A partir de uma revisão sistemática da literatura, este artigo analisa criticamente a produção acadêmica mais citada nos últimos 18 anos sobre a liderança nos processos de criação e compartilhamento de conhecimento nas organizações. Os resultados apresentam uma série de conceitos de liderança relacionados a esses processos, fornecem uma análise das publicações quanto ao tratamento dado à liderança neste contexto, apresentam as diferentes teorias de liderança utilizadas e identificam quais os papéis atribuídos à liderança nos principais antecedentes literais sobre a temática.
Zheng Nengliang and Pedagogies of Affect in Contemporary China
Authors: Hizi Gil
Published: May 2021

This article examines the role of affect in market-driven self-cultivation. Drawing on a study of extracurricular workshops for interpersonal skills in urban China, I describe programs that prioritize momentary excitement, associated with the state-endorsed colloquialismzheng nengliang(positive energy), while distinguishing this experience from the common registers of the exterior world. I define these settings as ‘pedagogies of affect’, activities that bring to the fore the short-lived and indeterminant attributes of affect without coherently serving discursive ideologies in trajectories of social engineering or neoliberal governmentality. This phenomenon demonstrates how the expansion of market-driven expertise for ‘person-making’ to new social groups globally reinforces ethical disjunctures between different social domains, as well as between individuals’ practical and aspirational pursuits.
Digital Failures in Abolitionist Ethnography
Authors: Scott Jason Bartholomew
Published: May 2021

In an era when grassroots activism is defined by the use of social media, the democratic potentials of the Internet are constantly confronted by a shifting set of practical and political obstacles. Organizations seeking to abolish violent policing, for example, use social media to mobilize widespread support, but can fail to solidify lasting influence within government institutions. Similarly, twenty-first-century ethnographers have gained the ability to interact with grassroots organizations over social media, but often fail to gain insight into a movement’s internal politics or day-to-day struggles. This article focuses on the challenges of anti-violence activists in Brazilian favelas following the 2016 Rio de Janeiro Olympics. The author explores how ethnographers can create a sense of continuity out of digital failure.
Development and validation of a patient-centered, meningioma-specific quality-of-life questionnaire
Authors: Baba Ami , Saha Ashirbani , McCradden Melissa D. , Boparai Kanwar , Zhang Shudong , Pirouzmand Farhad , Edelstein Kim , Zadeh Gelareh , Cusimano Michael D.
Published: May 2021

OBJECTIVE

Meningiomas can have significant impact on health-related quality of life (HRQOL). Patient-centered, disease-specific instruments for assessing HRQOL in these patients are lacking. To this end, the authors sought to develop and validate a meningioma-specific HRQOL questionnaire through a standardized, patient-centered questionnaire development methodology.

METHODS

The development of the questionnaire involved three main phases: item generation, item reduction, and validation. Item generation consisted of semistructured interviews with patients (n = 30), informal caregivers (n = 12), and healthcare providers (n = 8) to create a preliminary list of items. Item reduction with 60 patients was guided by the clinical impact method, multiple correspondence analysis, and hierarchical cluster analysis. The validation phase involved 162 patients and collected evidence on extreme-groups validity; concurrent validity with the SF-36, FACT-Br, and EQ-5D; and test-retest reliability. The questionnaire takes on average 11 minutes to complete.

RESULTS

The meningioma-specific quality-of-life questionnaire (MQOL) consists of 70 items representing 9 domains. Cronbach’s alpha for each domain ranged from 0.61 to 0.91. Concurrent validity testing demonstrated construct validity, while extreme-groups testing (p = 1.45E-11) confirmed the MQOL’s ability to distinguish between different groups of patients.

CONCLUSIONS

The MQOL is a validated, reliable, and feasible questionnaire designed specifically for evaluating QOL in meningioma patients. This disease-specific questionnaire will be fundamentally helpful in better understanding and capturing HRQOL in the meningioma patient population and can be used in both clinical and research settings.
Outcomes associated with brain tissue oxygen monitoring in patients with severe traumatic brain injury undergoing intracranial pressure monitoring
Authors: Hoffman Haydn , Abi-Aad Karl , Bunch Katherine M. , Beutler Timothy , Otite Fadar O. , Chin Lawrence S.
Published: May 2021

OBJECTIVE

Brain tissue oxygen monitoring combined with intracranial pressure (ICP) monitoring in patients with severe traumatic brain injury (sTBI) may confer better outcomes than ICP monitoring alone. The authors sought to investigate this using a national database.

METHODS

The National Trauma Data Bank from 2013 to 2017 was queried to identify patients with sTBI who had an external ventricular drain or intraparenchymal ICP monitor placed. Patients were stratified according to the placement of an intraparenchymal brain tissue oxygen tension (PbtO2) monitor, and a 2:1 propensity score matching pair was used to compare outcomes in patients with and those without PbtO2 monitoring. Sensitivity analyses were performed using the entire cohort, and each model was adjusted for age, sex, Glasgow Coma Scale score, Injury Severity Score, presence of hypotension, insurance, race, and hospital teaching status. The primary outcome of interest was in-hospital mortality, and secondary outcomes included ICU length of stay (LOS) and overall LOS.

RESULTS

A total of 3421 patients with sTBI who underwent ICP monitoring were identified. Of these, 155 (4.5%) patients had a PbtO2 monitor placed. Among the propensity score–matched patients, mortality occurred in 35.4% of patients without oxygen monitoring and 23.4% of patients with oxygen monitoring (OR 0.53, 95% CI 0.33–0.85; p = 0.007). The unfavorable discharge rates were 56.3% and 47.4%, respectively, in patients with and those without oxygen monitoring (OR 1.41, 95% CI 0.87–2.30; p = 0.168). There was no difference in overall LOS, but patients with PbtO2 monitoring had a significantly longer ICU LOS and duration of mechanical ventilation. In the sensitivity analysis, PbtO2 monitoring was associated with decreased odds of mortality (OR 0.56, 95% CI 0.37–0.84) but higher odds of unfavorable discharge (OR 1.59, 95% CI 1.06–2.40).

CONCLUSIONS

When combined with ICP monitoring, PbtO2 monitoring was associated with lower inpatient mortality for patients with sTBI. This supports the findings of the recent Brain Oxygen Optimization in Severe Traumatic Brain Injury phase 2 (BOOST 2) trial and highlights the importance of the ongoing BOOST3 trial.
The Influence of Explicit Teaching and Utilization of Concept Mapping on EFL Students’ Listening Comprehension and Perceived Self-efficacy
Authors: Boroumand Mohsen , Mardani Mahdi , Khakzad Esfahlan Farzaneh
Published: May 2021

One of the most important communicative skills is listening and, at the same time, the Achilles’ heel of many L2 learners as it entails multi-level cognitive processes (Lynch, 2002). Besides, as various studies show, selfefficacy measures are closely tied to the effective use of learning strategies. Considering the key role that concept mapping, as an indispensable cognitive learning strategy, and self-efficacy play on an individual’s achievement (Bandura, 1986, 1997), the present study aimed to examine the influence of explicit teaching and utilization of concept mapping on Iranian EFL students’ listening achievement and perceived self-efficacy. The participants were sixty intermediate university students studying English as a foreign language. They were assigned into two groups, namely control and one experimental group, each including thirty participants. The students in the experimental group were trained to utilize concept mapping while doing their routine listening tasks. The instruments were a self-efficacy questionnaire and a test of listening achievement. The findings indicated that the experimental group performed significantly better in the listening achievement test after learning to use a concept-mapping strategy. Likewise, their perceived self-efficacy in accomplishing listening tasks improved after the intervention period.
Are Two Heads Better than One? Comparing Engagement between Pairs and Individuals in an L2 Writing Task
Authors: Hiromori Tomohito
Published: May 2021

This study examined the performance of university foreign language learners on a writing task by comparing paired work (n = 50) against individual work (n = 50). Data were collected based on three aspects of learners’ task engagement: behavioural (time spent working on the task, number of words written), linguistic (English writing scores), and affective (attitudes toward the task). The results showed that (1) all participants worked on the task for the same amount of time and produced a similar number of words, (2) texts written by pairs were similar to and as accurate/fluent as those written individually, and (3) learners who worked in pairs evaluated the task more positively than did those who worked individually. A more detailed examination using cluster analysis revealed that while there was generally a positive relationship between each aspect of task engagement, a trade-off might occur depending on the situation, and one aspect might mediate the effect of others. In addition, by examining the differences between a successful and a less successful pair, this study provides pedagogical implications in relation to the use of pair work activities in the language classroom.
On the Relationship between Iranian English Language Teaching Students’ Self-efficacy, Self-esteem, and their Academic Achievement
Authors: Noorollahi Neda
Published: May 2021

The present study explores the relationship between self-esteem, self-efficacy, and academic achievement among Iranian graduate students majoring in English Language Teaching (ELT) by presenting a model of the interrelationship among these three constructs. To this end, 229 students, male (N=80) and female (N=149), were selected from among different universities of Khorasan Razavi Province, Iran. AMOS software, Schwarzer, and Jerusalem’s self-efficacy questionnaire were utilised to conduct the study and Rosenberg’s self-esteem questionnaire. Also, to assess the participants’ academic achievement, their Grade Point Average (GPA) was used as a criterion measure based on their self-report evaluation. The results of the Pearson correlation indicated that there were significant positive relationships between self-efficacy and self-esteem (r=.641, p<.05), selfefficacy and academic achievement (r=.609, p<.05), and self-esteem and academic achievement (r=.519, p<.05). The goodness of fit indices revealed that all the fit indices lie within the acceptable fit thresholds. Results of the model showed that both self-efficacy (β= .44, p<.05) and self-esteem (β= .22, p<.05) were significant positive predictors of students’ achievement. Therefore, self-efficacy was a better predictor of GPA. The model also demonstrated that self-efficacy positively and significantly (β= .57, p<.05). The findings of the study might have some pedagogical implications for language teaching and learning.
QUASIHARMONIC BENDING WAVE, DISTRIBUTING IN THE BALK OF TIMOSHENKO, LYING ON A NONLINEAR ELASTIC BASE
Authors: Erofeev V.I. , Leontieva A.V.
Published: May 2021

In this paper, we consider the modulation instability of a quasiharmonic flexural wave propagating in a homogeneous beam fixed on a nonlinear elastic foundation. The dynamic behavior of the beam is determined by Timoshenko's theory. Timoshenko's model, refining the technical theory of rod bending, assumes that the crosssections remain flat, but not perpendicular to the deformable midline of the rod; normal stresses on sites parallel to the axis are zero; the inertial components associated with the rotation of the cross sections are taken into account. The uniqueness of the model lies in the fact that, allowing a good description of many processes occurring in real structures, it remains quite simple, accessible for analytical research. The system of equations describing the bending vibrations of the beam is reduced to one nonlinear fourthorder equation for the transverse displacements of the beam particles. The nonlinear Schrödinger equation, one of the basic equations of nonlinear wave dynamics, is obtained by the method of many scales. Regions of modulation instability are determined according to the Lighthill criterion. It is shown hot the boundaries of these areas shift when the parameters characterizing the elastic properties of the beam material and the nonlinearity of the base change. Nonlinear stationary envelope waves are considered. An equation that generalizes the Duffing equation, which contains two additional terms in negative powers (first and third), is obtained and qualitatively analyzed. Solutions of the Schr?dinger equation in the form of envelope solitons are found and the dependences of their main parameters (amplitude, width) on the parameters of the system are analyzed. The dynamics of the points of intersection of the amplitudes and widths of "light" solitons in the case of soft nonlinearity of the base is shown within the region of modulation instability.
TRANSIENT CONTACT INTERACTION OF A RIGID DIE AND ELASTIC HALF-SPACE WITH A CAVITY
Authors: Arutyunyan A.M. , Fedotenkov G.V.
Published: May 2021

A closed mathematical formulation of plane non-stationary contact problems for rigid dies and an elastic half-space with deepened cavities is constructed. Using the dynamic theorem of reciprocity of works, a system of resolving equations is obtained. It includes the basic boundary integral equation arising from the principle of reciprocity and boundary conditions, as well as the equations of translational and rotational motion of the die. The fundamental and singular solutions for the elastic plane are the cores of the main resolving equation. They determine displacements and stresses in the elastic plane from the applied single instantaneous concentrated force. An original solution algorithm based on the method of boundary integrals with an additional iterative procedure that allows one to take into account the partial separation of the boundary surfaces of the die and the half-space in the contact area has been developed and implemented on a computer. In this case, at each moment of time in the half-space, there is a region that is in a perturbed state and outside of which there are no perturbations. The integral operators of the resolving system of equations are replaced by discrete analogs in the spatial variable and in time. A parametric study of the process of unsteady contact of an absolutely rigid rectangular die with a half-space having a recessed cavity is carried out. Analysis of the calculation results revealed the manifestation of a significant effect of the cavity on the process of non-stationary contact interaction. The influence of the cavity begins to show itself from the moment the reflected waves arrive from its boundary. In this case, the nature of the unsteady stress-strain state and displacements changes significantly. The developed calculation algorithm can be used in engineering practice by design and research organizations in the process of designing and calculating buildings and structures under the influence of natural and man-made vibrations propagating in the soil.
Three-queries file organizations
Authors: Lipski Witold
Published: May 2021

The following combinatorial problem arising in file organization is considered: Given three sets M1, M2, M3 ⊆ X, find an arrangement of X such that each Mi is a segment of consecutive elements of X. Also some theorems extending the results of Ghosh concerning the two-dimensional consecutive retrieval property are proved. In particular, necessary and sufficient condition for a family of three sets to admit a two-dimensional organization is given.
Investigations of properties of programs by means of the extended algorithmic logic I
Authors: Banachowski Lech
Published: May 2021

The present paper contains investigations concerning the semantic correctness of programs. Presented methods of analysis of programs are appropriate for every domain of computation. Algorithmic logic extended by classical quantifiers is a fundamental mathematical tool used in the paper. Interrelations between properties of programs and properties of descriptions of programs are studied (a description of a program is a mathematical model of the notion of a documentation of a program).
The resolution principle for ω+-valued logic
Authors: Orłowska Ewa
Published: May 2021

A resolution-style theorem proving system for the ω+-valued Post logic is developed. The soundness and the completeness of the system are proved. The two versions of the Herbrand theorem for the logic considered are given.
Analysis of coroutines by means of vector of coroutines
Authors: Janicki Ryszard
Published: May 2021

In this paper two methods of proving properties of programs with coroutines are presented. Both of these methods are based on a mathematical model which was defined in [3] and extended in [4], and which is called a vector of coroutines. In the case of the first method, the vector semantics is given by the least solution of an appropriate set of equations. This set of equations is constructed on the basis of the form of the whole vector. In the case of the second method, a suitable alphabet and a suitable language are associated with each of the vector components (each component corresponds to one coroutine of the program), and the intersection of these languages is interpreted as a description of the vector semantics. The theorem on the replacement of components by equivalent (in a special sense) components is proved.
Fixed-points and algebras with infinitely long expressions: Part II. μ-clones of regular algebras
Authors: Tiuryn Jerzy
Published: May 2021

This paper is a continuation of Tiuryn [16]. The main notion presented in the latter paper is the notion of a regular algebra. As it was proved in Tiuryn [16] for an arbitrary signature Σ the algebra of regular Σ-trees is an initial regular algebra. This means that there are naturally defined “polynomials” for regular algebras, which are determined by infinitely long expressions. The aim of this paper is to investigate this phenomenon.
Completions of ordered magmas
Authors: Courcelle Bruno , Raoult Jean-Claude
Published: May 2021

We give a completion theorem for ordered magmas (i.e. ordered algebras with monotone operations) in a general form. Particular instances of this theorem are already known, and new results follow. The semantics of programming languages is the motivation of such investigations.
On stability of probabilistic automata in environments1
Authors: Gould Jerren
Published: May 2021

Flachs [1], Rabin [7], and Paz [6] have considered topics in the stability of probabilistic automata. Here we extend these results to the more general forms, automata in deterministic environments (ADE). We shall be concerned with two types of stability problems that arise from small perturbations of the environment configurations for an ADE. By consideration of the asymptotic properties of long products of stochastic matrices whose entries are subject to small perturbations concomitant to the environment configuration perturbations, we arrive at sufficient conditions for the state distribution function to be stable (s-stability). In its acceptor formulation the behavior of an ADE is characterized by the sets T ( A, e, λ), the set of tapes accepted by A with environment sequence e and cut-point λ. Sufficient conditions are given for tape-acceptance stability (a-stability) in terms of s-stability and in terms that do not require s-stability. These stability results are pointwise results that give the size of the perturbation of the environment configuration to avoid instability.
A note on the intersection of context-free languages
Authors: Păun Gheorghe
Published: May 2021

It is shown that a) there is an equal matrix language which cannot be written as a finite intersection of context-free languages and b) any finite intersection of context-free languages can be generated by a regular conditional grammar with context-free control languages.
Axioms for multilevel objects
Authors: Bergstra J.A. , Goeman H.J.M. , Ollongren A. , Terpstra G.A. , van der Weide Th.P.
Published: May 2021

A set of axioms for structured objects of data is presented. In the structured objects components and levels are distinguished. Change of level is the result of a special application operator, components are accessible by successive selections. The set of access paths is also axiomatized. The set of axioms is uniform in the sense that features of various known classes of datastructures are combined.
Sets generated by stochastic automata of Markov’s chain type
Authors: Janicki Sławomir
Published: May 2021

In the earlier paper of the author [2] it has been introduced the concept of the generability for stochastic automaton. Here we give new necessary and sufficient conditions for the generability of the set of infinite sequences of automaton states. Moreover, we consider the generability of subset, complement, union, intersection and difference of generable sets.
The metric space of infinite trees. Algebraic and topological properties
Authors: Arnold Andre , Nivat Maurice
Published: May 2021

The set of infinite trees is considered as an ultrametric compact space. The composition of trees is investigated. Applications to non deterministic recursive program schemes are given.
Continuously generated fixed points in P ω1
Authors: Bracho Felipe
Published: May 2021

In this paper we investigate the fixed points of functions that can be obtained by continuous fixed point operators in P ω. We also introduce an operator Cgn that generates all of these fixed points for any continuous function. In the last two sections of the paper we study the fixed points of λ a . a ∘ a (retracts) and of λ y λ f . f ( ( y ) ( f ) ) (fixed point operators).
On Eliminating the λ-Rules from Simple Matrix Grammars
Authors: Paun Georghe
Published: May 2021

It is proved that the λ-rules increase the generative capacity of context-free simple matrix grammars but can be eliminated from right-linear simple matrix grammars and from linear simple matrix grammars without diminishing their generative capacity.
Global Syntax and Semantics for Recursively Enumerable Languages
Authors: Calude Cristian , Pǎun Gheorghe
Published: May 2021

According to (Benson, 1970), a syntax is a category of strings and derivations (modulo similarity) between them. In this paper the semantic domain is an elementary topes. Thus, an interpretation of a syntax is a cofunctor taking strigs to products and derivations to morphisms. It is proved the existence of a free x – category U such that every syntax is a full subcategory of U, which can be determined recursively. Every interpretation of a syntax is the restriction of the interpretation of U.
APC: The Algorithmic Predicate Calculus
Authors: Przyłuski Wojciech
Published: May 2021

The paper presents a logic which is an algorithmic extension of the classical predicate calculus and is based on the ideas given by F. Kröger. The programs and the effects of their execution are the formulas of this logic which are considered at any time scale. There are many interesting properties of the logic which are connected with the notion of time scale. These properties are examined in the paper. Moreover the problem of the formulas normalization is presented. Our logic is compared with the algorithmic logic introduced by A. Salwicki. Next, the usefulness of a new logic in the theory of programs is shown.
Implicit Definability of Algebraic Structures by Means of Program Properties1
Authors: Bergstra Jan , Tiuryn Jerzy
Published: May 2021

The following problem is investigated in the paper: what structures can be uniquely defined by algorithmic properties? The algorithmic properties are represented in this paper as open formulae of the logic of effective definitions. This approach can be viewed as an alternative way of defining abstract data types.
PAL – Propositional Algorithmic Logic
Authors: Mirkowska Grażyna
Published: May 2021

The aim of propositional algorithmic logic is to investigate the properties of program connectives. Complete axiomatic systems for deterministic as well as for nondeterministic interpretations of program variables are presented. They constitute basic sets of tools useful in the practice of proving the properties of program schemes. Propositional theories of data structures, e.g. the arithmetic of natural numbers and stacks, are constructed. This shows that in many aspects PAL is close to first-order algorithmic logic. Tautologies of PAL become tautologies of algorithmic logic after replacing program variables by programs and propositional variables by formulas. Another corollary to the completeness theorem asserts that it is possible to eliminate nondeterministic program variables and replace them by schemes with deterministic atoms.
Algorithmic Degrees of Algebraic Structures
Authors: Bergstra Jan , Tiuryn Jerzy
Published: May 2021

We define a reducibility relation ⩽ between algebraic structures A ⩽ B means that A can be embeddet in an enrichment of B with partial computable operations. This notion is a generalized version of implementability as known in the theory of algebraic data types.