Multiple Gaps Research Articles

Propagation mechanism of low-frequency elastic waves and vibrations in a new tetragonal hybrid metamaterial

In order to achieve low-frequency vibration and noise reduction, artificial metamaterial with great potential in this field have been widely found. Based on previous studies, a new tetragonal hybrid metamaterial structure is proposed in this paper. It is exciting that the combination of inclusions with different material properties and sizes can affect the generation of band gaps. Then, based on the selected frequency, the propagation characteristics of waves in the structure were qualitatively analyzed using group velocity and phase velocity, and the potential for vibration reduction and noise reduction of the proposed structure was verified through finite element simulation of vibration in finite period structures. The results show that the proposed structure can open multiple broadband gaps, and the frequency range of the band gap can be flexibly adjusted according to needs. This study provides a new way for the design of low-frequency phononic metamaterial systems.

Translating data into narratives

Today more than ever, it is evident the role that data can play when designing policies. Not only can understandable data orient better strategies, but they can also enable reflexive practices within Public Administrations, giving directions for knowledge management and smarter governance. However, multiple gaps concur to affect data understanding and interpretation, hindering their subsequent translation into policy-valuable information. To tackle challenges related to data interpretation and usage, the article (i) illustrates a narrative approach for building profiles of cities as narrative feedback from sets of data and (ii) investigates their potential as a (self-)evaluation and a decision-making support device. The feedback structure relies on the conceptual model built for the DIGISER Project, which investigated multidimensional digital transition processes across European cities. Dynamic feedback retrieves data from the project dataset, translating them into discursive form. The effectiveness of the approach and its device is validated through a qualitative enquiry on a textual excerpt provided to three different departments of one of the cities that participated in the survey. The study corroborates that designing narrative feedback as semantic interpretations can trigger understanding, (self-)reflection and support policy change, informing policy formulation and facilitating cross-silo interactions across administrative units engaged in digital transformation processes.

Floquet non-Abelian topological insulator and multifold bulk-edge correspondence

Topological phases characterized by non-Abelian charges are beyond the scope of the paradigmatic tenfold way and have gained increasing attention recently. Here we investigate topological insulators with multiple tangled gaps in Floquet settings and identify uncharted Floquet non-Abelian topological insulators without any static or Abelian analog. We demonstrate that the bulk-edge correspondence is multifold and follows the multiplication rule of the quaternion group Q8. The same quaternion charge corresponds to several distinct edge-state configurations that are fully determined by phase-band singularities of the time evolution. In the anomalous non-Abelian phase, edge states appear in all bandgaps despite trivial quaternion charge. Furthermore, we uncover an exotic swap effect—the emergence of interface modes with swapped driving, which is a signature of the non-Abelian dynamics and absent in Floquet Abelian systems. Our work, for the first time, presents Floquet topological insulators characterized by non-Abelian charges and opens up exciting possibilities for exploring the rich and uncharted territory of non-equilibrium topological phases.

A Systematic Literature Review on Humour Advertising: The ADO Model Approach

Humour as an appeal is one of the earlier appeals that attracted marketers and has attracted researchers’ interest in recent years. In lieu, the current paper systematically reviews various types of humour. The objective of the current study is to trace the research gaps and furnish directions for future research. The current paper considered articles from 2002–2022 on humour advertising. Multiple research gaps were outlined employing ADO (Antecedents, Decision, and Outcomes) model. The study finds that humour advertising has been effective if the sources are credible. The likability of the brand increases, and that finally affects the buying intention. The potential avenues of research in a similar domain are discussed at the end of the paper. It facilitates practitioners about the various types of humour appeal and methodical thinking to further advancement in the area of humour appealed advertising.

Study of the energy spectrum of a few one-dimensional and quasi one-dimensional lattices through tight binding and density functional theory

A graphene nanoribbon (GNR) is a strip of carbon atoms having sp2 hybridization. It has wide application in nanoelectronics and opto-electronics. Usual fields of application are found in field effect transistors, interconnects, logic gates, sensors, energy storage, and photovoltaics. A single unit graphene nanoribbon is a long strip of graphene rings. Such a GNR structure may be seen as two one-dimensional carbon chains that are suitable connected with bonds. We have done tight binding calculations and density functional theory simulation of carbon chains. We study the single bond and double bond one-dimensional carbon chain and the alternate bond (t1-t2), also called a bond order system in one dimension and quasi one-dimensional chain. We find evidence for the emergence of multiple gaps in the energy spectrum of these systems. We have mapped the alternate bond system to the Su–Schrieffer–Heeger model (with a small modification) in one dimension and quasi one dimension. This is the first time such a mapping has been attempted and a comprehensive theoretical and computational study of these chains has been performed.

Rabies elimination policy guidelines: Where do we stand?

Introduction: Rabies is one of the Neglected Tropical diseases. India accounts for 35% of rabies-related human deaths globally. Despite effective preventive and control strategies, India hasn't been able to eliminate rabies. Methodology: A narrative review was done by comparing various policies and programmes related to rabies control and elimination in India and other countries, and the gaps persisting in the Indian guidelines and its implementation were assessed. Results: There are multiple gaps in the Indian programme implementation ranging from multiple stockouts of vaccines, unavailability of rabies immunoglobulin, and lack of a robust surveillance system to lack of refreshing training of the health staff. Recommendations: For effective implementation, the population should have increased awareness, with increased production and an effective supply chain of vaccines and immunoglobulins. There should also be a robust surveillance system with periodic refresher training of the health staff.

Evaluating the gap choice decisions of pedestrians in conflict situations in mass religious gatherings and controlled experimental setup – A pilot study

Previous studies on modelling the microscopic behaviour of pedestrians have focused on conflict resolution among pedestrians in pedestrian-pedestrian interactions. Many of these models propose alternate mechanisms to avoid conflicts by introducing repulsive forces between pedestrians or a set of predefined rules stating the precedence of movements to sidestep obstacles and other pedestrians. However, the possibility of formulating the decision-making mechanism pedestrians use to overcome conflicts as a gap-seeking behaviour has not been explored. In this study, resolving conflicts between opposing pedestrians is modelled as gap choice decisions made by individuals. Pedestrians looking for gaps or spaces in a crowd to facilitate their movement form the basis for such an analysis. The study compares pedestrians' gap acceptance behaviour across two scenarios: pedestrian movement in a field setup (Kumbh Mela) and a controlled experiment. Multiple gap choice decisions of individuals are modelled to understand the effect of individual-level heterogeneity on gap choices. Apart from the gap duration, spacing, position of gap, linear density, age, and presence of luggage significantly influenced the gap choices. Model validation is done using appropriate methods for both field and experimental data. The bootstrap method of internal validation and holdout validation is used to assess the performance of the estimated model on field data and experimental data, respectively. It is seen that the models have reasonable predictive and discriminative abilities. The analysis results also indicate that pedestrians tend to force gaps to facilitate movement in their natural state. Consequently, controlled experiments might have limitations in reproducing or motivating the participants to behave like a crowd.

Training on Corrections and Health Within U.S. Academic Health Professions Education: A Scoping Review.

Despite the scale, inequity, and consequences of mass incarceration, health care provider knowledge and awareness on correctional health remain limited. Understanding the educational experiences of health professions learners and the studies used to evaluate them can provide useful information about current gaps to guide future curricular improvement. To address this need, we conducted a scoping review of peer-reviewed studies examining United States-based academic health professions educational programs on correctional health. Studies were coded based on study characteristics, learner outcomes, and degree to which they contained elements described in relevant position statements by two professional medical associations. Overall, 27 articles (1975-2021) were included. Learner outcomes were primarily documented at the "reactions" (93%) and "learning" (52%) levels of the Kirkpatrick model (1979), relative to "behaviors" (11%) and "long-term outcomes" (0%). Comparison of curricula to select position statements revealed multiple content gaps in the realms of prevalent conditions requiring expertise (e.g., violence and self-harm); ethical and medical-legal considerations (e.g., privatization of correctional health care); and correctional health care systems, structures, and administration. Taken together, findings highlight gaps in, and opportunities for, correctional health educational programs. Addressing health care workforce training needs is a necessary yet insufficient step to achieving health equity for populations affected by incarceration.

Knowledge shortfalls for titi monkey: A poorly known clade of small-bodied South American primates

Titi monkeys (Callicebus, Cheracebus, and Plecturocebus) comprise the most species-rich group of primates in South America. Thirty-six currently recognized species composing this group inhabit a multitude of habitats across most of South America. While field-based and laboratory research has provided insights into the behavior, ecology, and physiology of some titis, multiple knowledge gaps regarding their biodiversity patterns persist. Here, we provide an overview of titi research and identify their biodiversity knowledge shortfalls. Using online databases, we collated the literature of all titi studies published up to December 31, 2021. We compiled 521 publications, with 48 % representing in situ field studies of the monkeys. The majority of field-based publications focused on studies conducted in Brazil and Peru. We found that research efforts have increased in recent decades, as indicated by the increased number of publications on titis. However, given the large number of species and their wide distribution across South America, there is limited information about most of these species and their geographic ranges. By highlighting the focal points where conservation-related data are still required, our findings demonstrate the importance of expanding research efforts and investment on the full extent of titi species and their entire geographic regions; doing so will help fill the knowledge shortfalls rather than solely advancing the study of a restricted range of topics in one or two habitats or countries. These advances will contribute to fill knowledge gaps through the creation/expansion of data repositories, citizen science programs, and increased financial support to maintain long-term data collection.

Perovskites: An Emerging Technology in Solar Space

The extent of interest which Perovsite technology is generating in solar research space is unprecedented. And there is a genuine rationale behind that. In the last one decade, the progress in efficiencies exhibited by Perovskite Solar Cells (PSCs) has gone up manifold. This is an outcome of the intensive research being done by various research organizations on efficiency enhancement of the PSCs and the various solar companies which are trying to bring this technology closer to large scale commercialization. The wide belief is that perovskites will be less expensive compared to conventional technology. While the perovskite technology is demonstrating a sea of opportunities, there is still a journey to cover. There are multiple research gaps on the road to commercialization of the perovskite technology which need to be addressed. The more important amongst them are durability and stability, rapid degradation due to UV, dissolution issue due to water exposure, degradation through oxygen and hysteresis behaviour. Having said that, the pace of research in solar space has been much faster compared to any other technology transformations the world has seen. And global warming and climate change related studies are further necessitating this pace to accelerate further. This article gives a brief history of perovskite, its technological progression, the research gaps as they stand today and what the future holds for this technology. Looking at the progress in perovskite technology, the world may not be far away from seeing a disruption in solar space.

Use of French Broad River Drainage Basin Topographic Map Evidence Upstream from Asheville, North Carolina to Test a New Geology and Glacial History Paradigm, USA

Topographic map evidence in the western North Carolina French Broad River drainage basin (upstream from Asheville) was used to determine if a new geology and glacial history paradigm (new paradigm) can explain previously unexplained (and anomalous) drainage system evidence. The new paradigm claims: 1) the Eastern Continental Divide was uplifted as the southeastern rim of a continental ice sheet created deep “hole” (in which the ice sheet was located) as immense and prolonged southwest-oriented meltwater floods flowed across it, 2) headward erosion of south and southeast-oriented valleys (in sequence from the southwest to the northeast) diverted floodwaters more directly to the Atlantic Ocean, and 3) headward erosion of north- and northwest-oriented valleys from the developing deep “hole” (in sequence from the southwest to the northeast) diverted floodwaters to deep “hole” space (located between the rising deep “hole” rim and the ice sheet margin) and then toward deep “hole” southern exits (eventually the Mississippi River valley became the only southern exit). The new paradigm permitted the following types of drainage system evidence to be explained:1) numerous barbed tributaries flowing to a northeast-oriented French Broad River segment, 2) a larger than required northeast-oriented French Broad River valley, 3) and diverging and converging valley complexes which are found throughout the northeast-oriented oriented French Broad River headwaters drainage basin. In addition, the map evidence could be interpreted to show: 1) headward erosion of the north- and northwest-oriented French Broad River valley captured southwest-oriented flow to the north-oriented Pigeon River valley which had captured flow to the northwest-oriented Little Tennessee River valley, 2) headward erosion of the south-oriented Broad River valley captured southwest-oriented flow to the northeast- and north-oriented French Broad River and the south-oriented Toxaway River and 3) and multiple gaps identify locations where southwest-oriented water entered and exited the present-day French Broad River headwaters drainage basin.

Physicians' perceptions and beliefs on the current dyslipidemia management practices within Saudi Arabia

BackgroundLimited reports addressing physicians’ understanding of the various low-density lipoprotein cholesterol (LDL-C) targets/statin intensity required for treating the various dyslipidemia patient populations in Saudi Arabia are available. Therefore, the current study assessed the perceptions and beliefs of practicing clinicians in Saudi Arabia regarding the current practice for management of dyslipidemia and potential perceived barriers to adherence to lipid guidelines encountered in their regular clinical practice. Knowledge of different clinical practices and beliefs could have a positive impact on improving the quality of future care provided by physicians. MethodsA survey questionnaire was designed to assess physicians’ familiarity, usage, and adherence to seven different international guidelines and used to evaluate the management of dyslipidemia, practice of patient treatment, and perceived obstacles to adhering to lipid guidelines related to specific patients, doctors, and practice issues. ResultsA total of 467 physicians were recruited for the study: (1) 57.2% were primary care physicians (PCPs) and (2) 42.8% were specialists. About 90.8% of them followed lipid guidelines of which the most common set were based on those by the American College of Cardiology/American Heart Association. The most utilized risk assessment tool was the atherosclerotic cardiovascular disease (ASCVD) risk calculator. About 60% of the physicians set an LDL-C target for their patients based on a combination of patients’ risk factors and lipid profiles. In all, 42.1% of the physicians chose not to change existing therapy among patients with dyslipidemia to attain a non-high-density lipoprotein goal with controlled LDL-C level. Atorvastatin accounted for the greatest percentage of primary and secondary prevention choices (71.9% and 69.6%, respectively). Rosuvastatin was mostly preferred by physicians for patients with familial hypercholesterolemia. About two-thirds of the physicians (77.9%) prescribed statins to diabetic patients aged 40–75 years. Statin intolerance was encountered by 62.9% of the physicians in ≤ 10% of patients by 62.9%. Therapeutic strategies included switching to an alternative statin (40.1%) followed by reducing the statin dose (35.3%). Ezetimibe was prescribed by most physicians (77.9%) as an add-on to statin if the LDL-C target was not achieved. Fibrate was most preferred by physicians (62.7%) for hypertriglyceremia treatment followed by statins (28.7% of the physicians). Sixty-six percent reported not using proprotein convertase subtilisin/kexin type 9 serine protease inhibitors in their clinical practice due to unavailability at their institute (51.8%), high costs (26.3%), and/or lack of knowledge (20.6%). Perceived barriers to guideline adherence identified by physicians were lack of familiarity and knowledge of the guidelines, patient non-adherence, medication costs, and lack of timely follow-up appointments and educational tools. Multiple similarities and differences were observed after comparisons were made between specialists and PCPs in terms of guideline preference, clinical practice, and perceived barriers. ConclusionDifferent perceptions and attitudes among physicians in Saudi Arabia were found due to variable recommendations by international lipid guidelines. Perceived barriers that included the patient, physician, and practice were identified by physicians at multiple levels. Multiple challenges and different action gaps were observed when comparing specialists to PCPs. It is recommended that standardized practices be followed by clinicians in Saudi Arabia, and actions to address the outlined barriers are essential for optimizing health outcomes and ASCVD prevention.

Characteristics of band gaps of a metamaterial plate with membrane-type resonators based on the energy approach

Local resonance metamaterials have garnered substantial interest in recent years due to their potential to effectively control low-frequency noise and vibration. This study proposes a new metamaterial plate with double mass membrane-type resonators (DMMRs). Combining polynomial fitting and virtual spring method, the natural characteristics of the resonator and the dispersion surfaces of the metamaterial plate are obtained. Results show the proposed metamaterial plate exhibits multiple band gaps, resulting from the cancellation of shear forces in the plate by the reaction forces generated by the first two resonances of the resonators. Parametric analysis is performed to obtain the variation patterns of the band gaps, where approximate models of the resonator are adopted to explain the effects of the parameters. It is found that the occurrence and width of the two band gaps are closely related to the mass ratio between the masses on the resonator and the substrate plate. Furthermore, finite element analysis is conducted to verify the effectiveness of the theoretical derivation, as well as the suppression effect of the metamaterial plate. The findings demonstrate the advantages of the metamaterial plate in vibration control and band gap tuning. The study provides guidance for the design and analysis of elastic wave metamaterials.

A critical review of microplastics toxicity and potential adverse outcome pathway in human gastrointestinal tract following oral exposure

Microplastics (MPs) are typically produced via environmental degradation of larger plastics, where they enter the human food chain. MPs are complex materials containing chemical and physical characteristics that can potentially affect their hazard and exposure. These physical properties can be altered by environmental exposure potentially altering any risk assessment conducted on the primary material. We conducted a literature review using an Adverse Outcome Pathway (AOP)-based approach from Molecular Initiating Event (MIE) to cell effect event to identify multiple knowledge gaps that affect MPs hazard assessment. There is some convergence of key biological events but could relate to most lying along well-established biological effector pathways such as apoptosis which can respond to many MIEs. In contrast, MIEs of chemicals will be via protein interaction. As MPs may occur in the lumen of the alimentary canal for example to the mucus, therefore, not requiring translocation of MPs across the epithelial membrane. At the other end of the AOP, currently it is not possible to identify a single adverse outcome at the organ level. This work did establish a clear need to understand both external and internal exposure (resulting from translocation) and develop hazard data at both levels to inform on risk assessments.

Definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in amyotrophic lateral sclerosis (ALS): Consensus from ALS and Motor Neuron Disease Scientific Department of the Brazilian Academy of Neurology.

The spectrum of neuropsychiatric phenomena observed in amyotrophic lateral sclerosis (ALS) is wide and not fully understood. Disorders of laughter and crying stand among the most common manifestations. The aim of this study is to report the results of an educational consensus organized by the Brazilian Academy of Neurology to evaluate the definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in ALS patients. Twelve members of the Brazilian Academy of Neurology - considered to be experts in the field - were recruited to answer 12 questions about the subject. After exchanging revisions, a first draft was prepared. A face-to-face meeting was held in Fortaleza, Brazil on 9.23.22 to discuss it. The revised version was subsequently emailed to all members of the ALS Scientific Department from the Brazilian Academy of Neurology and the final revised version submitted for publication. The prevalence of pseudobulbar affect/pathological laughter and crying (PBA/PLC) in ALS patients from 15 combined studies and 3906 patients was 27.4% (N = 1070), ranging from 11.4% to 71%. Bulbar onset is a risk factor but there are limited studies evaluating the differences in prevalence among the different motor neuron diseases subtypes, including patients with and without frontotemporal dementia. Antidepressants and a combination of dextromethorphan and quinidine (not available in Brazil) are possible therapeutic options. This group of panelists acknowledge the multiple gaps in the current literature and reinforces the need for further studies.

Zero-thermal-expansion metamaterial with broadband vibration suppression

Although conventional metamaterials possess extraordinary properties, they cannot meet the practical requirements of engineering structures subjected to both temperature fluctuations and vibration excitations. To bridge this research gap, this paper proposes a novel dual-functional metamaterial with zero thermal expansion and broadband vibration suppression. Inspired by the thermal mismatch and band gap effects, we present an innovative design strategy that incorporates star-shaped re-entrant lattices and locally rudder-shaped struts with two-phase materials. To effectively guide the coupled design, a theoretical model accounting for stretching-bending deformations is established to predict the thermoelastic behavior of the metamaterial. Moreover, a parameterized dynamic model using the spectral element method is developed to study the vibration characteristics. Particularly, the spectral formulation of curved Timoshenko beams is derived, including in-plane and out-of-plane vibrations. The comparisons between theoretical predictions and finite element simulations validate the accuracy of analytical models in characterizing thermal deformations and vibration responses. Finally, the case studies shed light on the underlying formation mechanisms of zero thermal expansion and multiple band gaps, while also unveiling the effects of geometric parameters on the performance of such dual-functional metamaterials. Our innovative design strategy and analytical methodology not only offer appealing alternatives for engineering applications but also push the boundaries of metamaterial properties by enabling the transition from single- to dual-functionality.

Crossing multiple solar energy gaps: A Dutch case study on intermediation for building-integrated photovoltaics

Building-integrated photovoltaics are a promising technology to enhance renewable energy production in the built environment while improving the aesthetics of buildings at the same time. Several challenges hinder this technology's uptake, such as information asymmetry and limited value chain coordination. Prior work demonstrates that the support of intermediaries can play a crucial role in coping with these challenges, but this aspect has not yet been previously investigated for this technology. A comprehensive overview is lacking of how various intermediaries can support a multi-stage decision process. Rather than focusing on specific intermediary actors, we explore the Dutch system for building-integrated photovoltaics, identifying which actors act or can act as an intermediary, and what intermediation activities can support the decision process. This article identifies the need for intermediation at the various stages of the decision process and the actors best suited to providing this. Drawing from our empirical findings from 26 in-depth interviews and the literature on innovation adoption and intermediaries, the results reveal that a dynamic ‘ecology of intermediaries’ is necessary to perform various intermediation activities at different system levels in the multi-stage decision process. As these activities and actors are highly interrelated and interdependent, we argue that it is vital to assess intermediation in a holistic way. These findings are significant for suppliers, potential intermediaries, and governments because they can support improving the decision process with the help of intermediation. The present paper contributes to innovation and intermediation studies by demonstrating that intermediation is an interrelated, multi-level, and variegated phenomenon.

Innovative structural design of chiral lattices with low frequency wide multiple band gaps and vibration suppression

In order to achieve low-frequency vibration and noise reduction, this paper proposes an innovative structure based on the four-ligament chiral structure. The band gap characteristics and the principle of band gap generation are numerically analyzed by using the finite element method. By optimizing the proposed structure, the band gap is obviously transferred to the low frequency. The propagation characteristics of elastic waves with a specific frequency on the passband in the proposed structure are studied. Finally, the calculated band gap frequency range is compared with the finite element simulation results, and the two correspond perfectly. The research shows that the proposed structure has a good bandgap frequency range, which can play a good role in suppressing vibration transmission, and by improving the chiral structure of the basic four ligaments, the bandgap frequency range of the structure can be transferred from a high frequency to low frequency, which provides ideological guidance and scheme for the structural design of metamaterial that suppress low-frequency waves.

Fundamental Limits of Cache-Aided MIMO Wireless Networks

This paper studies the Multi-Input-Multi-Output (MIMO) interference networks with arbitrary number of transmitters and receivers, where both the transmitters and receivers are equipped with caches. The main goal is to design content placement and delivery schemes that minimize the worst case normalized delivery time (NDT). First, we propose a delivery scheme for the cache-aided Single-Input-Multiple-Output (SIMO) interference networks. Then, we obtain the achievable NDT of the cache-aided MIMO interference networks using the decomposition property of splitting each multi-antenna transmitter into multiple single antenna transmitters. Furthermore, we derive an information-theoretic bound on the optimal NDT of the cache-aided MIMO interference network. Analytical results show that the proposed scheme is within a multiplicative gap of 2 from the derived lower bound independent of all system parameters for any uncoded cache placement scheme. We also derive a novel delivery scheme for the cache-aided Multi-Input-Single-Output (MISO) interference network outperforming our proposed scheme for the cache-aided MIMO interference network. The numerical results show the superiority of our proposed scheme over the state-of-the-art schemes in the literature. Our results show that the coded caching gain has a more significant contribution in reducing the transmission latency than the spatial multiplexing gain. Our results indicate that the receive-antennas become more effective in reducing the NDT than the transmit-antennas in the presence of caches at the receiver-side. In addition, we show that increasing the number of transmit-antennas has a higher gain in reducing the NDT than adding more transmitters in the cache-aided MISO interference network.

"Go With the Flow": A Qualitative Description of Infant Feeding Experiences Among Women With HIV in the United States.

Breastfeeding affords numerous health benefits to mothers and children, but for women with HIV in the United States, avoidance of breastfeeding is recommended. Evidence from low-income countries demonstrates low risk of HIV transmission during breastfeeding with antiretroviral therapy, and the World Health Organization recommends exclusive breastfeeding and shared decision making about infant feeding options in low-income and middle-income countries. In the United States, gaps in knowledge exist surrounding the experiences, beliefs, and feelings of women with HIV surrounding infant feeding decisions. Undergirded by a framework of person-centered care, this study describes the experiences, beliefs, and feelings of women with HIV in the United States surrounding recommendations for breastfeeding avoidance. Although no participants reported consideration of breastfeeding, multiple gaps were identified with implications for the clinical care and counseling of the mother-infant dyad.