Functional Dependence Research Articles

Association of Seizure Control with Mortality, Cognition, and Function in People With Dementia.

The effects of seizure control on outcomes in persons with dementia (PWD) remain unclear. Our study aimed to investigate the impact of seizure control on mortality, function, cognition, and mood among PWD. This longitudinal, multicenter study is based on 39 Alzheimer's disease centers (ADCs) in the United States from September 2005 to December 2021. PWD were grouped by seizure status into recurrent (seizures in the past year), remote (prior seizures but none in the past year), and no seizures (controls). The primary outcome was all-cause mortality among seizure groups. We used Weibull survival analysis to assess the mortality risks by seizure status after adjusting for age, sex, education, race, ethnicity, hypertension, diabetes, hyperlipidemia, degree of cognitive impairment, dominant Alzheimer's disease (AD) mutation, brain trauma, stroke, Parkinson's disease, alcohol abuse, and depression. Cognition (Clinical Dementia Rating), function (physical dependence and nursing home residence), day-to-day activities (Functional Assessment Scores), and mood (Geriatric Depression Scale) were compared among seizure groups after adjusting for dementia duration and age. Among 26,501 participants, 374 (1.4%) had recurrent seizures and 510 (1.9%) had remote seizures. In multivariable survival analysis, recurrent seizures were associated with a higher mortality risk than remote and no seizures (adjusted hazard ratio [aHR], 95% confidence interval [95% CI]; recurrent aHR = 1.79, 95% CI = 1.51 to 2.12; remote aHR = 1.17, 95% CI = 0.98 to 1.38). Median time-to-death for recurrent, remote, and no seizures was 2.4, 4.0, and 4.7 years, respectively. People with recurrent seizures had worse cognition, day-to-day function, and physical dependence than those with remote seizures and controls. PWD with poorly controlled recurrent seizures have worse mortality, functional, and cognitive outcomes than PWD with remote and no seizures. These findings underscore the need for timely identification and management of ongoing seizures in PWD. ANN NEUROL 2024.

Association of renal biomarkers with fast progressor phenotype and related outcomes in anterior circulation large vessel occlusion stroke.

Renal dysfunction is a known predictor of long-term functional dependency after anterior circulation large vessel occlusion (ACLVO) stroke. However, the impact of renal dysfunction on early infarct growth rate (IGR) has not been previously demonstrated. The objective of this study was to define the association of creatinine-based renal biomarkers with fast or slow progressor phenotypes and related clinical outcomes in ACLVO stroke. This retrospective study examined patients with acute intracranial internal carotid artery or middle cerebral artery-M1 occlusions admitted between 2014 and 2019. Patients were included if they received baseline CT perfusion (CTP) or MRI on presentation within 24 h of estimated stroke onset. Infarct growth rate (IGR) was determined by ischemic core volume on CTP or MRI divided by time from stroke onset to imaging. IGR was used to stratify fast progressor (IGR ≥10 mL/h) and slow progressor (IGR < 10 mL/h) status. Renal dysfunction was assessed based on serum creatinine and estimated glomerular filtration rate (eGFR) on presenting laboratories. Logistic regression models, adjusted for significant covariates, identified independent associations between renal dysfunction biomarkers, progressor status, and clinical outcomes based on modified Rankin Scale (mRS) at 90 days. Among 230 patients with ACLVO, 29% were fast progressors, with median serum creatinine levels higher than slow progressors (1.1 vs. 0.9 mg/dL, p < 0.05) and lower median eGFR (66.2 vs. 69.0 mL/min/1.73m2, p < 0.05). Elevated creatinine (≥1.2 mg/dL) was independently associated with fast progressor status (adjusted OR 2.37, 95% CI 1.18-4.77), worse 90-day mRS (adjusted OR 1.88, 95% CI 1.01-3.51) and mortality (adjusted OR 2.57, 95% CI 1.14-5.79). Reduced eGFR (<60 mL/min/1.73m2) was independently associated with fast progressor status (adjusted OR 2.38, 95% CI 1.14-4.94), but not with 90-day mRS or mortality. Serum creatinine-based biomarkers of renal dysfunction were associated with fast progressor phenotype of ACLVO stroke, and worse clinical outcomes, which may help identify such patients earlier during emergency evaluation for expedited access to EVT. Future prospective studies are warranted to confirm and test implementation of these findings.

The Implication Problem for Functional Dependencies and Variants of Marginal Distribution Equivalences

We study functional dependencies together with two different probabilistic dependency notions: unary marginal identity and unary marginal distribution equivalence. A unary marginal identity states that two variables \(x\) and \(y\) are identically distributed. A unary marginal distribution equivalence states that the multiset consisting of the marginal probabilities of all the values for variable \(x\) is the same as the corresponding multiset for \(y\) . We present a sound and complete axiomatization for the class of these dependencies and show that it has Armstrong relations. The axiomatization is infinite, but we show that there can be no finite axiomatization. The implication problem for the subclass that contains only functional dependencies and unary marginal identities can be simulated with functional dependencies and unary inclusion atoms, and therefore the problem is in polynomial-time. This complexity bound also holds in the case of the full class, which we show by constructing a polynomial-time algorithm.

Association between possible sarcopenia, all-cause mortality, and adverse health outcomes in community-dwelling older adults in China

The relationship between possible sarcopenia and mortality remains ambiguous within Asian populations. To clarify this, we investigated the association in older adults residing in Chinese communities. Utilizing data from the China Health and Retirement Longitudinal Study, this population-based cohort study included individuals aged ≥ 60 years, followed from 2011 to 2012 through 2020. Possible sarcopenia was defined in accordance with the Asian Working Group on Sarcopenia 2019 criteria, and Cox proportional hazards regression was used to analyze its impact on mortality, while exploratory analyses were conducted to investigate the associations of possible sarcopenia with chronic diseases, functional independence, and hospitalization frequency. The study encompassed 5,160 participants (median age: 66 years), nearly half of whom (48.8%) were identified with possible sarcopenia. Over a 9-year follow-up period, there were 1216 recorded deaths. Analysis indicated that individuals with possible sarcopenia faced a significantly elevated mortality risk compared to their counterparts (HR: 1.79, 95% CI: 1.58–2.03; P < 0.001). Further, subgroup analyses confirmed a strong association between possible sarcopenia and all-cause mortality across various subgroups, including those related to sex, obesity status, and living environment. Additionally, exploratory analyses revealed that possible sarcopenia was significantly associated with an increased likelihood of heart disease (OR = 1.18, 95% CI: 1.03–1.34, P = 0.014) and stroke (OR = 1.41, 95% CI: 1.19–1.68, P < 0.001), as well as reduced functional independence (β = -0.17, 95% CI: -0.24–-0.10, P < 0.001). Possible sarcopenia was also associated with a higher frequency of hospitalizations at baseline (Exp(β) = 1.50, 95% CI: 1.25–1.81, P < 0.001), although this association was no longer significant during the follow-up period. In conclusion, in Chinese community-dwelling older adults, possible sarcopenia was associated with an increased risk of all-cause mortality, several chronic diseases, and functional dependence. Thus, alleviating or preventing possible sarcopenia may improve health outcomes and extend the lifespan of these individuals.

Subclinical variability in visual function modulates visual dependence - independent of age.

Paradoxically visual dependence is reported to increase with age, contributing to falls risk, whereas visual function typically declines. This study assesses the relationship between age, objective and subjective measures of visual function and visual dependence, in healthy young and older adults. Forty-four healthy Young (YA; n = 32; 18 males, aged 26.2 ± 5.3 yrs.) and Older (OA; n = 12; 3 males, aged 62.4 ± 6.7 yrs.) adults were assessed for objective (visual acuity, contrast sensitivity, depth perception, and lower peripheral vision), and subjective visual function (VFQ-25) along with motion sickness susceptibility. Subjective Visual Vertical (SVV) and induced nausea and vection were assessed using the Rod and Disc Test (RDT). Groups were compared using Mann-Whitney U, whilst determinants of SVV variability were evaluated using Multiple regression modelling. Visual acuity (p < 0.01) and contrast sensitivity (p = 0.04) were lower in OA. Visual dependence (SVV tilt errors) was not associated with ageing (p = 0.46). YA experienced greater RDT-induced vection (p = 0.03). Visual acuity and contrast sensitivity accounted for modest proportions of variance in SVV tilt errors (VA; R2 = 0.14, F(1,42) = 8.00, p < 0.01; β = 6.37) and (CS; R2 = 0.06, F(1,42) = 3.93, p = 0.05; β = -4.97), respectively. Our findings suggest that subclinical differences in visual acuity and contrast sensitivity contribute to SVV tilt error variability, among both healthy young and older adults. Further studies are needed to define the inter-relationship between age-related visual function, non-visual factors (including vestibular and somatosensory fidelity, activity levels, fear of falling and cognitive function) and visual dependence.

Social prescribing for healthy ageing: insights from older people referral and uptake in Portugal

Abstract The population ageing presents multifaceted challenges for health systems, with implications for healthcare delivery and health and well-being outcomes. Innovative integrated-care approaches are needed to promote healthy aging and the quality of life of older people. Social Prescribing (SP) has emerged as a promising strategy to address the complex health and social needs of populations, including those older, offering non-medical interventions that encompass social, cultural, and community-based activities. SP has been implemented in Portugal since 2018 and currently target different subgroups, including elderly. This study aims to examine referral and uptake of older people to SP in Portugal. This cross-sectional study analysed sociodemographic, health condition, referral and uptake-related data from older patients (≥65 years) engaged in SP, collected through a survey and registries at primary healthcare units in Lisbon between 2018-2023. Of the 1060 patients referred to SP, 43.9% (n = 465) were aged 65 years or older. Within this age group, 38.1% were 71-80 years old and 36.1% were 81-90 years old; 67.5% were female. Around 48% were referred to SP for social isolation, 40% for social and financial support, and 32.5% for functional dependency. Two thirds had two or more chronic conditions, with cardiovascular disease (59,1%), mental health disorders (29,2%), and obesity (27,1%) being the most frequent. The SP consultations uptake rate was 59.1%, and patients were referred to a range of activities provided by third-sector organisations, as psychosocial support, home care, senior university classes, arts activities, and support in medicine management. The elderly population accounts for a large proportion of SP referrals. Further efforts are needed to identify the factors that influence patients’ acceptability and adherence and to promote the sustainability of SP and the well-being of the population. Key messages • Older people referred to SP initiative in Portugal have complex health-social needs, which reinforces the relevance of adopting a holistic centred-care approach to respond to the aging challenges. • Through SP older people have been integrated in community-based activities that promote their health and wellbeing, thus it is needed to develop tailored strategies to improve patient uptake.

A severity comparison of leukoaraiosis in ischemic and hemorrhagic stroke: a retrospective study.

Leukoaraiosis (LA) is a common neuroradiological finding in patients suffering from stroke. Cerebral small-vessel disease (SVD) is one of the primary causes of both ischemic stroke and hemorrhagic stroke (intracerebral hemorrhage, ICH) and the development of LA. Significant evidence that LA predicts the risk of functional dependency and mortality exists. However, studies examining the difference in LA severity between ischemic stroke and hemorrhagic stroke are lacking. We therefore aimed to compare the severity and abundance of LA in the two stroke subgroups. All patients admitted to the Department of Neurology, Haukeland University Hospital, with an ischemic stroke and intracerebral hemorrhagic (ICH) stroke diagnosed between 2006 and 2020 were included in the study. We collected patient data on risk factors and clinical and radiological findings and outcomes from our local stroke registry. The presence and severity of LA were assessed using the Fazekas score based on CT imaging. We evaluated the outcome using the modified Rankin Score (mRS) 7 days post-stroke. A total of 5,084 patients were included in our analyses: 4437 (87%) with ischemic stroke and 647 (13%) with ICH. LA was present in 2476 (45%) patients. In our ordinal logistic regression model, adjusting for age, sex, known hypertension, known diabetes mellitus, and smoking, LA was more severe and more abundant in ICH patients compared to ischemic stroke patients (Fazekas score: 1, OR: 1.54; Fazekas score: 2, OR: 1.88; and Fazekas score: 3, OR 2.13; p < 0.001). Increasing severity of LA was associated with worse functional outcomes in both groups (ischemic stroke, OR: 1.49; p < 0.001 and ICH, OR: 1.36; p < 0.025). In this study, LA was more severe and abundant in patients with ICH.

A modified transactional model of stress and coping on depressive symptoms among informal caregivers of persons with dementia

Informal caregivers are crucial to the care of persons with dementia (PWD), but their role is often reported as challenging. This study aims to examine caregiver stress and depressive symptoms among informal caregivers of PWD using a modified transactional stress and coping model. Path analysis was conducted among a sample of informal caregivers of PWD in Singapore (n = 281) using information on functional dependence and memory and behavioral problems of PWD, and self-reported measurements on caregivers’ knowledge of dementia, perceived positive aspects of caregiving, social support, coping patterns, caregiving self-efficacy, caregiving burden and depressive symptoms. The initial model reflecting our assumptions for the transactional stress and coping model showed a poor fit (model 1 - CFI = 0.858, TLI = 0.665, RMSEA = 0.118). Logical modifications were made until sufficient model fit was achieved (model 2 - CFI = 0.987, TLI = 0.955, RMSEA = 0.043). We then removed the insignificant paths in model 2 and obtained our final model (model 3 - CFI = 0.990, TLI = 0.974, RMSEA = 0.033). The final model supported our hypotheses, with some adjustments. This study advances our understanding of caregiver distress by modifying the transactional stress and coping model, including (1) the key role of caregiver self-efficacy in the primary appraisal process, (2) the dynamic assessment of coping resources across all stages of the model, and (3) the importance of coping patterns. Future studies could explore the generalizability of these findings.

Nutritional Status Impact on Hip Fracture Patients in a Rural Environment.

(1) Background: Hip fractures are highly prevalent traumatic events with significant functional consequences, particularly among the older population. These fractures are associated with increased mortality, postoperative complications, and functional dependence. Medical and nutritional factors such as malnutrition and sarcopenia are crucial for predicting functional outcomes and mortality in these patients. This study aimed to assess the nutritional status, vitamin D levels, and sarcopenia, as well as their relationship with mortality, mean hospital stay, and 30-day-readmission rate, in patients with hip fracture who underwent surgery in a rural hospital setting. (2) Methods: A longitudinal retrospective study involving 124 patients who underwent hip fracture surgery in 2021 was conducted. Sociodemographic, surgical, and nutritional data, including vitamin D, albumin, and blood urea nitrogen (BUN) levels, were collected. (3) Results: The average age of the sample was 89.1 years, with a postoperative 30-day-mortality rate of 8.1% and an average hospital stay of 10.4 days. Vitamin D deficiency was present in 79.7% of patients, and a high prevalence of malnutrition was indicated by low albumin and elevated BUN levels. Elevated BUN levels and low vitamin D levels were associated with higher mortality. (4) Conclusions: Adequate nutritional assessment in patients with hip fracture is vital for identifying the risks of complications and mortality. Understanding the current nutritional status and its associated complications will aid in developing strategies to improve health and reduce complications in the future.

Ultralow thermal conductivity in Si–Ge nanograin mixtures: A cost-effective granular material for thermoelectric applications

This paper presents a theoretical study of the thermal conductivity of Si–Ge nanograin mixtures using a multiscale computational methodology based on solving the Boltzmann transport equation for phonons with first-principles techniques. A size-dependent correction factor is developed to account for the spatial dependence of the phonon distribution function on nanograin size, with parameters derived from the phonon properties of infinite Si and Ge crystals. This approach makes it possible to accurately calculate the thermal conductivity within a single nanograin, using force constants obtained from first-principles calculations. Thermal energy transport by phonons across grain boundaries is modeled by accounting for phonon transmission by two-phonon processes, weighting specular, and diffuse transmission for each phonon mode as a function of the root-mean-square roughness of the boundary relative to the phonon wavelength. The boundary thermal conductance model, previously validated against experimental data, is implemented using first-principles techniques. This approach excludes specular transmission for phonon modes with specific symmetries while ensuring conservation of the total number of modes in each symmetry class. The study examines the influence of grain size, nanograin mixture composition, temperature, and boundary asperities on the thermal conductivity of nanograin mixtures.

Prognostic understanding among caregivers of persons with dementia: A scoping review.

Despite the influence of caregivers' prognostic understanding (PU) on the end-of-life care for persons with dementia (PwDs), the literature on PU of caregivers of PwDs is sparse. We conducted a scoping review to understand the variation in existing definitions and measurement of caregivers' PU for PwDs. We also aimed to synthesize the prevalence of caregivers' correct PU and the factors (caregiver, PwD and healthcare related) associated with it. We systematically searched four databases-MEDLINE/PubMed, EMBASE, SCOPUS, and CINAHL. We included studies where study participants were informal caregivers, their PU was assessed, and measurement tool was implicitly described. We excluded studies where study participants were paid caregivers. Out of the 2160 studies screened, we included 15 published between 2009 and 2023. The included studies measured caregivers' PU as limited estimated life expectancy, understanding that dementia is incurable and life-limiting. Estimated life expectancy was the most common measure of PU among caregivers to PwDs. Across studies, around 90% of caregivers acknowledged dementia as incurable, while only about 40% acknowledged it as life-limiting. Caregivers of PwDs who were sicker (acute medical problems or functional dependence) and those who had discussed goals of care with healthcare providers were more likely to have more accurate PU for PwDs. Caregivers' with better PU were more likely to state a preference for comfort-focused care, and their PwDs were likely to receive fewer burdensome interventions and experience greater comfort during the dying process. Our findings highlight the need for a comprehensive measure to assess the multifaceted nature of caregivers' PU, delve deeper into factors influencing caregivers' PU, and explore its impact on caregivers themselves.

Study of Complexation Patterns in the System Ni2+, MoO42–, P2O74–, Cit3–for the Development of Poly-Ligand Electrolytes (Study of complexation patterns)

The complexation behavior in systems containing Ni2+, MoO42−, P2O74−, Cit3− - ions have been thoroughly investigated. The study determined the composition and instability constants of both mono- and biligand complex compounds at a constant ionic strength of the solution (Ic=1). By analyzing the concentration ratios of the complexing agent and ligands, the composition of mono- and polyligand complexes was elucidated. The complexation study utilized the potentiometric method, which is based on the functional dependence of the potential of the indicator electrode on the concentration of the complexing agent ions. The results enabled the calculation of the ionic composition of aqueous solutions of nickel complexes with citrate and diphosphate ions, depending on their concentrations. A proposed scheme for the formation of heteronuclear nickel-molybdenum complexes takes into account the sequence of component introduction into the electrolyte to form complexes of a specific composition. These findings were applied to develop electrolyte compositions for coating with alloys based on iron subgroup metals with molybdenum. These alloys exhibit several valuable properties, including corrosion resistance, electrocatalytic activity in hydrogen production, and enhanced operational characteristics.

Psychophysics of user acceptance of social cyber-physical systems.

A mini-review of the literature, supporting the view on the psychophysical origins of some user acceptance effects of cyber-physical systems (CPSs), is presented and discussed in this paper. Psychophysics implies the existence of a lawful functional dependence between some aspect/dimension of the stimulation from the environment, entering the senses of the human, and the psychological effect that is being produced by this stimulation, as reflected in the subjective responses. Several psychophysical models are discussed in this mini-review, aiming to support the view that the observed effects of reactance to a robot or the uncanny valley phenomenon are essentially the same subjective effects of different intensity. Justification is provided that human responses to technologically and socially ambiguous stimuli obey some regularity, which can be considered a lawful dependence in a psychophysical sense. The main conclusion is based on the evidence that psychophysics can provide useful and helpful, as well as parsimonious, design recommendations for scenarios with CPSs for social applications.

Loneliness and pet ownership among dependent older adults in a Southern European urban context

Objective Identify the role that pet ownership may play in mitigating feelings of loneliness among dependent older adults, with a particular focus on gender and mobility problems. Method We use a representative sample of dependent individuals aged 65 and over (n = 1,600), with 1,005 self-respondents in Barcelona, drawn from the 2023 Survey of Older People with Functional Dependency. Logistic regression models assess the associations between pet ownership (dog, cat, or other animal) and perceived loneliness in older dependents. Models are stratified by gender. Results The analysis highlights that dog ownership and receiving family care are factors associated to lower risk of perceived loneliness, particularly among women. In contrast, the association between pet ownership and loneliness is less clear for men for whom no differences were observed between dog owners, other pet owners and individuals without pets in the outcome measure. Our analyses also reveal that the benefits of dog ownership hold only for old age dependents with mobility impairments. Conclusion Our results provide evidence that gender, type of pet and mobility are key variables associated to loneliness. These findings underscore the importance of considering dog ownership and family involvement in care strategies to mitigate loneliness among older dependents.

Spectroscopy and annihilation decay widths of charmonium and bottomonium excitations

We study the charmonium ( cc¯ ) and bottomonium ( bb¯ ) spectra, using Cornell potential with additional constant potential term in a non-relativistic framework, with spin-dependent corrections corresponding to the spin–spin, spin–orbit, and tensor interactions added perturbatively. We predict the masses of low-lying and excited states of charmonium and bottomonium up to n = 6 and L = 2. We analyze the radial and orbital Regge trajectories of both the systems and investigate their departure from linearity. Further, we estimate the wave function at the origin and, consequently, predict the decay widths of charmonium and bottomonium states annihilating to leptons and photons. Also, we investigate the effect of scale dependence of the wave function at the origin and the strong coupling constant on the predictions of annihilation decay widths. We compare our predictions of heavy quarkonium spectra and decay widths with experimental results and other theoretical models.

The Association Between Cognitive Function and Oral Health in Home Dwellers and Nursing Home Residents: The HUNT Study.

To evaluate the relationships of cognitive function and care dependency with oral health in a Norwegian older adult population. This cross-sectional study included 2623 participants aged 70 and older from the fourth wave of the Trøndelag health study (HUNT4 70+) and the city of Trondheim (Trondheim 70+). Neurocognitive disorders (NCDs) were diagnosed by clinical experts according to the DSM-5 framework. Care dependency referred to nursing home residency. Oral health was assessed by using the Revised Oral Assessment Guide-Jönköping (ROAG-J). Individuals were considered as 'having oral problem' if the score was two or three in at least one of the nine ROAG-J items. Poisson regression was used to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs). The prevalence of having oral problems was 19% higher in participants with NCDs than those with normal cognitive function after adjusting for potential confounders (PR 1.19, 95% CI: 1.09-1.29). Further analysis showed a higher prevalence of having oral problems for home dwellers with NCDs (PR 1.23, 95% CI: 1.13-1.33) and nursing home residents (PR 1.32, 95% CI: 1.20-1.45) compared to home dwellers with normal cognitive function. NCDs were associated with an increased prevalence of oral problems in this Norwegian older adult population. The study suggests the need for increasing oral care for home dwellers with NCDs and nursing home residents.

An Extended Algorithm using a Divide-and-Rule Approach for Boundary Value Analysis and Equivalence Class Partitioning

An extended algorithm using a divide-and-rule approach is proposed in this paper. Instead of generating test cases by only using Boundary Value Analysis and an experience-based technique for combination of input variables with functional dependency like the original algorithm, the extended algorithm applies both Boundary Value Analysis and Equivalence Class Partitioning techniques as well as various techniques for combination of input values. In addition, a new tool provides advantages when compared with the original tool. It provides users with more choices in generating test cases.

Determining the Need for Palliative Care Patients with Multiple Sclerosis-A Cross-Sectional Study.

Multiple sclerosis is characterised by the manifestation of heterogeneous symptoms that affect daily functioning. Patients face physical impairment, psychological problems and socioeconomic changes. Depending on the form of the disease, they may have different needs, which are often unsatisfied and could be overcome by including palliative care in the treatment. Despite the above, not enough is known about this population's needs for palliative care. This cross-sectional study aimed to identify the need for palliative care and assess the functional dependence level in daily living activities in patients with multiple sclerosis. The sample consisted of 120 patients from the Neurology Clinic of the University Clinical Center of Vojvodina, Serbia. The following research instruments were used: a General questionnaire, Sheffield Profile for Assessment and Referral for Care, Multiple Sclerosis Impact Scale and Barthel Index. The need for palliative care was expressed by 36.7% of patients, who expressed the most concern for the physical symptoms, independence and activity domains. Also, it was determined that the disease prevents patients from doing demanding physical tasks and that they are worried about multiple sclerosis. Almost a quarter of patients have had complete/severe dependence on other persons in performing daily activities. The most frequently reported physical symptoms by patients with MS were weakness, bladder problems, fatigue and different levels of dependence, while concerns related to sexual health, low mood and anxiety emerged as key challenges in the psychological domain. These findings underscore the importance of conducting needs assessments to guide the development of an appropriate palliative care model for MS patients.

Plastic deformation of [001]-oriented single-crystal iron under shock compression: Effects of void size

The thermomechanical behavior of materials is known to be sensitive to preexisting defects in their microstructure. In this paper, non-equilibrium molecular dynamics simulations have been used to investigate the effects of the microvoid size on the plastic deformation in single-crystal iron shock-compressed along the [001] crystallographic direction. The higher the microvoid radius, the faster the kinetics of dislocations. Thus, as the microvoid radius increases, the plastic activity evolves from a regime where the deformation is dominated by twin activities to a regime where both twin and dislocation activities play an essential role and then to a regime where the deformation is dominated by dislocation slip. Furthermore, in both defect-free and defective initial crystal states, the elastic precursor wave is observed to decay with propagation distance, resulting in a constitutive functional dependence of the yielding pressure, σE, on the plastic deformation rate, ε˙p. In the regime where both deformation twinning and dislocation slip play important roles, the constitutive behavior is consistent with the original Swegle–Grady model and is in overall agreement with experimental data and thermomechanical simulations.

Non-blocking functional dependency discovery from data streams

With the proliferation of sensors and IoT technologies, there is an increasing need to analyze information from data streams that they produce dynamically. However, the volume and velocity of this data require algorithms that mine knowledge as data are read from streams. The capability of dynamically extracting functional dependencies (fds) from data streams would not only permit to assess and improve the quality of data, but also provide knowledge on the evolution of data correlations within streams, allowing to understand the relevance that each feature has in predicting unknown features. In this paper, we propose a new discovery algorithm, namely COD3, which allows to continuous discovery fds holding on a data stream, as the data are read from it. COD3 represents the first proposal to use a non-blocking architectural model for discovering fds from data streams. Furthermore, we present novel data structures and a validation method to handle dynamic discovery and reduce data load inbound streams. Experimental evaluations demonstrate its effectiveness on both adapted real-world datasets and real data streams, such as those from air quality sensors. Moreover, by integrating COD3 with Bleach, a well-known fd-based data stream cleansing framework, we demonstrate its effectiveness in a real-world use case.