bluuebunny/crossref_metadata_2025 huggingface dataset:
Climatically driven instability of marine methane hydrate along a canyon-incised continental margin
Authors: Davies Richard J. , Maqueda Miguel Ángel Morales , Li Ang , Ireland Mark
Published: April 2021

Establishing how past climate change affected the stability of marine methane hydrate is important for our understanding of the impact of a future warmer world. As oceans shallow toward continental margins, the base of the hydrate stability zone also shallows, and this delineates the feather edge of marine methane hydrate. It is in these rarely documented settings that the base of the hydrate stability zone intersects the seabed and hydrate can crop out where it is close to being unstable and most susceptible to dissociation due to ocean warming. We show evidence for a seismically defined outcrop zone intersecting canyons on a canyon-incised margin offshore of Mauritania. We propose that climatic, and hence ocean, warming since the Last Glacial Maximum as well as lateral canyon migration, cutting, and filling caused multiple shifts of the hydrate stability field, and therefore hydrate instability and likely methane release into the ocean. This is particularly significant because the outcrop zone is longer on canyon-incised margins than on less bathymetrically complex submarine slopes. We propose considerably more hydrate will dissociate in these settings during future ocean warming, releasing methane into the world’s oceans.
Chemotherapy as cause of refractory severe headache in a case of small-cell lung cancer
Authors: Rai Ankita Chouksey , Goyal Abhishek , Khurana Alkesh Kumar , Vangala Anoohya
Published: April 2021

Small-cell lung cancer (SCLC) is a very fast growing form of cancer and is characterised by early metastasis. As a result, chemotherapy is the mainstay of treatment. Platinum-containing combination regimens are the current treatment of choice for limited stage-SCLC and extensive stage SCLC. Various adverse effects after cisplatin and etoposide chemotherapy include nausea, nephrotoxicity, cardiotoxicity, hepatotoxicity, neurotoxicity, alopecia, gastrointestinal toxicity and myelosuppression. However, severe headache has not been reported yet. Here, we report one such case of severe refractory headache postcisplatin and etoposide chemotherapy which responded only to change in chemotherapy regime. All pertinent causes of headache were ruled out prior to changing the chemotherapy regimen.
Early presentation of traumatic pseudoaneurysm of deep lingual artery as a massive oral bleed
Authors: Rathod Ramya , Choudhary Neha , Hosur Bharat , Bansal Sandeep
Published: April 2021

Tongue trauma with active bleed is most commonly due to the ruptured lingual artery and its branches, whereas delayed haemorrhage is usually secondary to pseudoaneurysm formation. This case is a unique presentation of traumatic tongue bleeds with early formation of pseudoaneurysm of a lingual artery branch. We present our experience in its management. A contrast-enhanced CT (CECT) with angiography detected right deep lingual artery pseudoaneurysm, which was managed by endovascular gelfoam embolisation followed by tongue laceration repair. Tongue bleed stopped immediately post embolisation; tongue viability and functions restored on postoperative day 1 of repair. No complications like secondary haemorrhage or tongue necrosis were noted at 1-month follow-up. High index of suspicion for lingual artery and/or its branch pseudoaneurysm is crucial in acute and uncontrollable traumatic tongue bleed. A CECT is a minimum norm in early diagnosis. Choice of management is the cornerstone of a successful outcome.
Spontaneous neonatal scrotal haematoma: an early manifestation of severe haemophilia
Authors: Lee Jeffrey Soon-Yit , Chieng Chae-Hee , Martin Macprihelna , Toh Teck-Hock
Published: April 2021

We report a term newborn who presented on day 3 of life with unilateral, tender scrotal swelling with skin discolouration, which was subsequently diagnosed as haemophilia A at about 6 months of age. He received intramuscular vitamin K and hepatitis B vaccine at birth uneventfully. The scrotal swelling was treated as an infected hydrocoele, considering the absence of a family history of bleeding disorder and other risks of bleeding tendency, as well as the ultrasonographic features. He also had congenital pneumonia requiring venepuncture, non-invasive oxygen supplementation and intravenous antibiotics, without any complication. The swelling slowly improved over 2 months. He later developed post-trial vaccine injection haematoma at 4 months of age, and multiple non-traumatic bruises when he was 6 months old, leading to the diagnosis. This case demonstrates an uncommon, but a possible, early manifestation of haemophilia A at birth with a unilateral scrotal haematoma.
Telemedicine in oculoplastic and adnexal surgery: clinicians’ perspectives in the UK
Authors: Kang Swan , Raja Laxmi , Sim Dawn A , Thomas Peter B M , Ezra Daniel G
Published: April 2021

Background/Aims

The COVID-19 has facilitated a paradigm shift in the sphere of ophthalmic telemedicine: its utility is no longer limited to providing care to remote regions, rather it is expeditiously being adopted as the new standard of care. The aim of our paper is to explore the current attitudes of oculoplastic surgeons towards telemedicine and its utility in the present landscape and its prospects in the future.

Methods

A 39-item questionnaire was distributed to consultant oculoplastic surgeons practising across the UK and anonymised responses were collected and analysed.

Results

The COVID-19 pandemic has allowed rapid implementation of telemedicine services in oculoplastic departments across the UK with 86.6% of the respondents incorporating telemedicine into the routine clinical practice. Clinicians reported a statistically significant increase in utility of telemedicine, confidence in using telemedicine and quality of infrastructure available to employ telemedicine following the COVID-19 outbreak. The greatest utility of telemedicine is in triaging, postoperative assessment and eyelid lesion assessment. Main barriers to implementation of telemedicine included difficulties in conducting clinical examinations, lack of administrative support and poor access to digital technologies for patients. Overall, most clinicians were satisfied with the impact of telemedicine services and almost all experts foresee themselves continuing to use telemedicine in the future.

Conclusions

Telemedicine has become an integral part of the oculoplastic service delivery since the COVID-19 pandemic its use is likely to continue. Further development of digital infrastructure and improvement of clinical examination capabilities are required to enable its wider adoption.
Qualitative study: patients’ enduring concerns about discussing internet use in general practice consultations
Authors: Cuteanu Anita , Seguin Maureen , Ziebland Sue , Pope Catherine , Leydon Geraldine , Barnes Rebecca , Murray Elizabeth , Atherton Helen , Stevenson Fiona
Published: April 2021

Objectives

To examine patients’ accounts of their use of the internet before seeing a general practitioner (GP) using thematic analysis of semistructured interviews.

Design

Qualitative semistructured interview study with transcripts analysed thematically.

Setting

Primary care patients consulting with 10 GPs working at 7 GP practices of varying sizes and at a range of locations around London and the Southeast of England.

Participants

28 adult patients: 16 women and 12 men ranging in age from 18 to 75 from a range of self-defined ethnic backgrounds. Participants were selected based on instances when the patients reported having used the internet before the consultation, when patients referred to the internet in the consultation or when the physician used the internet or made reference to it during the consultation.

Results

Patients report that they can find health information online that they believe is reliable and helpful for both themselves and their GP. However, they report uncertainty about how to share internet-based findings and reluctance to disclose their efforts at researching health issues online for fear of appearing disrespectful or interfering with the flow of the consultation.

Conclusions

Despite the democratisation of access to information about health due via the internet, patients continue to experience their use of the internet for health information as a sensitive and potentially problematic topic. The onus may well be on GPs to raise the likelihood (without judgement) that patients will have looked things up before consulting and invite them to talk about what they found.
Association of traumatic brain injury severity and time to definitive care in three low-middle-income European countries
Authors: Peek-Asa Corinne , Coman Madalina Adina , Zorn Alison , Chikhladze Nino , Cebanu Serghei , Tadevosyan Artashes , Hamann Cara J
Published: April 2021

Background

Low-middle-income countries experience among the highest rates of traumatic brain injury in the world. Much of this burden may be preventable with faster intervention, including reducing the time to definitive care. This study examines the relationship between traumatic brain injury severity and time to definitive care in major trauma hospitals in three low-middle-income countries.

Methods

A prospective traumatic brain injury registry was implemented in six trauma hospitals in Armenia, Georgia and the Republic of Moldova for 6 months in 2019. Brain injury severity was measured using the Glasgow Coma Scale (GCS) at admission. Time to definitive care was the time from injury until arrival at the hospital. Cox proportionate hazards models predicted time to care by severity, controlling for age, sex, mechanism, mode of transportation, location of injury and country.

Results

Among 1135 patients, 749 (66.0%) were paediatric and 386 (34.0%) were adults. Falls and road traffic were the most common mechanisms. A higher proportion of adult (23.6%) than paediatric (5.4%) patients had GCS scores indicating moderate (GCS 9–11) or severe injury (GCS 0–8) (p<0.001). Less severe injury was associated with shorter times to care, while more severe injury was associated with longer times to care (HR=1.05, 95% CI 1.01 to 1.09). Age interacted with time to care, with paediatric cases receiving faster care.

Conclusions

Implementation of standard triage and transport protocols may reduce mortality and improve outcomes from traumatic brain injury, and trauma systems should focus on the most severe injuries.
Genetic burden linked to founder effects in Saguenay–Lac-Saint-Jean illustrates the importance of genetic screening test availability
Authors: Bchetnia Mbarka , Bouchard Luigi , Mathieu Jean , Campeau Philippe M , Morin Charles , Brisson Diane , Laberge Anne-Marie , Vézina Hélène , Gaudet Daniel , Laprise Catherine
Published: April 2021

The Saguenay–Lac-Saint-Jean (SLSJ) region located in the province of Quebec was settled in the 19th century by pioneers issued from successive migration waves starting in France in the 17th century and continuing within Quebec until the beginning of the 20th century. The genetic structure of the SLSJ population is considered to be the product of a triple founder effect and is characterised by a higher prevalence of some rare genetic diseases. Several studies were performed to elucidate the historical, demographic and genetic background of current SLSJ inhabitants to assess the origins of these rare disorders and their distribution in the population. Thanks to the development of new sequencing technologies, the genes and the variants responsible for the most prevalent conditions were identified. Combined with other resources such as the BALSAC population database, identifying the causal genes and the pathogenic variants allowed to assess the impacts of some of these founder mutations on the population health and to design precision medicine public health strategies based on carrier testing. Furthermore, it stimulated the establishment of many public programmes.

We report here a review and an update of a subset of inherited disorders and founder mutations in the SLSJ region. Data were collected from published scientific sources. This work expands the knowledge about the current frequencies of these rare disorders, the frequencies of other rare genetic diseases in this population, the relevance of the carrier tests offered to the population, as well as the current available treatments and research about future therapeutic avenues for these inherited disorders.
If it ducks like a quack: balancing physician freedom of expression and the public interest
Authors: Appel Jacob M
Published: April 2021

Physicians expressing opinions on medical matters that run contrary to the consensus of experts pose a challenge to licensing bodies and regulatory authorities. While the right to express contrarian views feeds a robust marketplace of ideas that is essential for scientific progress, physicians advocating ineffective or dangerous cures, or actively opposing public health measures, pose a grave threat to societal welfare. Increasingly, a distinction has been made between professional speech that occurs during the physician-patient encounter and public speech that transpires beyond the clinical setting, with physicians being afforded wide latitude to voice empirically false claims outside the context of patient care. This paper argues that such a bifurcated model does not sufficiently address the challenges of an age when mass communications and social media allow dissenting physicians to offer misleading medical advice to the general public on a mass scale. Instead, a three-tiered model that distinguishes between citizen speech, physician speech and clinical speech would best serve authorities when regulating physician expression.
Endovascular therapy with or without intravenous thrombolysis in acute stroke with tandem occlusion
Authors: Anadani Mohammad , Marnat Gaultier , Consoli Arturo , Papanagiotou Panagiotis , Nogueira Raul G , Spiotta Alejandro M , Bourcier Romain , Kyheng Maeva , Labreuche Julien , Siddiqui Adnan H , Ribo Marc , de Havenon Adam , Fischer Urs , Sibon Igor , Dargazanli Cyril , Arquizan Caroline , Cognard Christophe , Olivot Jean Marc , Anxionnat René , Audibert Gérard , Mazighi Mikael , Blanc Raphael , Lapergue Bertrand , Richard Sébastien , Gory Benjamin ,   TITAN (Thrombectomy In TANdem lesions) Investigators
Published: April 2021

Background

Endovascular therapy (EVT) is effective and safe in patients with tandem occlusion. The benefit of intravenous thrombolysis (IVT) prior to EVT in acute tandem occlusion is debatable.

Objective

To compare EVT alone with EVT plus IVT in patients with acute ischemic stroke due to anterior circulation tandem occlusions.

Methods

This is an individual patient pooled analysis of the Thrombectomy In TANdem lesions (TITAN) and Endovascular Treatment in Ischemic Stroke (ETIS) Registries. Patients were divided into two groups based on prior IVT treatment: (1) IVT+ group, which included patients who received IVT prior to EVT, (2) IVT− group, which included patients who did not receive IVT prior to EVT. Propensity score (inverse probability of treatment weighting (IPTW)) was used to reduce baseline between-group differences. The primary outcome was favorable outcome—that is, modified Rankin Scale (mRS) score 0 to 2 at 90 days.

Results

Overall, 602 consecutive patients with an acute stroke with tandem occlusion were included (380 and 222 in the bridging therapy and EVT alone groups, respectively). Onset to imaging time was shorter in the IVT+ group (median 103 vs 140 min). In contrast, imaging to puncture time was longer in the IVT+ group (median 107 vs 91 min). In IPTW analysis, the IVT+ group had higher odds of favorable outcome, excellent outcome (90-day mRS score 0–1), and successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b/3 at the end of EVT). There was no difference in the risk of significant hemorrhagic complications between groups. In secondary analysis of patients treated with acute cervical internal carotid artery stenting, bridging therapy was associated with higher odds of favorable outcome and lower odds of mortality at 90 days.

Conclusions

Our results suggest that bridging therapy in patients with acute ischemic stroke due to anterior tandem occlusion is safe and may improve functional outcome, even in the setting of acute cervical internal carotid artery stenting during EVT.
Major complications of dural venous sinus stenting for idiopathic intracranial hypertension: case series and management considerations
Authors: Townsend Robert Kyle , Jost Alec , Amans Matthew R , Hui Ferdinand , Bender Matthew T , Satti Sudhakar R , Maurer Robert , Liu Kenneth , Brinjikji Waleed , Fargen Kyle M
Published: April 2021

Background

Venous sinus stenting (VSS) is a safe, effective, and increasingly popular treatment option for selected patients with idiopathic intracranial hypertension (IIH). Serious complications associated with VSS are rarely reported.

Methods

Serious complications after VSS were identified retrospectively from multicenter databases. The cases are presented and management strategies are discussed.

Results

Six major acute and chronic complications after VSS were selected from a total of 811 VSS procedures and 1466 venograms for IIH. These included an acute subdural hematoma from venous extravasation, cases of both intraprocedural and delayed stent thrombosis, an ultimately fatal cerebellar hemorrhage resulting in acute obstructive hydrocephalus, venous microcatheter perforation during venography and manometry, and a patient who developed subarachnoid hemorrhage and subdural hematoma after cerebellar cortical vein perforation. The six cases are reviewed and learning points regarding complication avoidance and management are presented.

Conclusion

We report on six rare, major complications after VSS for IIH. Familiarity with these potential complications and appropriate timely management may allow for good clinical outcomes.
Association of reperfusion success and emboli in new territories with long term mortality after mechanical thrombectomy
Authors: Beyeler Morin , Weber Loris , Kurmann Christoph C , Piechowiak Eike Immo I , Mosimann Pascal J , Zibold Felix , Meinel Thomas Raphael , Branca Mattia , Goeldlin Martina , Pilgram-Pastor Sara M , Grunder Lorenz , Arnold Marcel , Seiffge David , Meier Raphael , Heldner Mirjam R , Dobrocky Tomas , Mordasini Pasquale , Gralla Jan , Fischer Urs , Kaesmacher Johannes
Published: April 2021

Background

The degree of reperfusion is the most important modifiable predictor of 3 month functional outcome and mortality in ischemic stroke patients treated with mechanical thrombectomy. Whether the beneficial effect of reperfusion also leads to a reduction in long term mortality is unknown.

Methods

Patients undergoing mechanical thrombectomy between January 2010 and December 2018 were included. The post-thrombectomy degree of reperfusion and emboli in new territories were core laboratory adjudicated. Reperfusion was evaluated according to the expanded Thrombolysis in Cerebral Infarction (eTICI) scale. Vital status was obtained from the Swiss population register. Adjusted hazard ratios (aHRs) using time split Cox regression models were calculated. Subgroup analyses were performed in patients with borderline indications.

Results

Our study included 1264 patients (median follow-up per patient 2.5 years). Patients with successful reperfusion had longer survival times, attributable to a lower hazard of death within 0–90 days and for >90 days to 2 years (aHR 0.34, 95% CI 0.26 to 0.46; aHR 0.37, 95% CI 0.22 to 0.62). This association was homogeneous across all predefined subgroups (p for interaction >0.05). Among patients with successful reperfusion, a significant difference in the hazard of death was observed between eTICI2b50 and eTICI3 (aHR 0.51, 95% CI 0.33 to 0.79). Emboli in new territories were present in 5% of patients, and were associated with increased mortality (aHR 2.3, 95% CI 1.11 to 4.86).

Conclusion

Successful, and ideally complete, reperfusion without emboli in new territories is associated with a reduction in long term mortality in patients treated with mechanical thrombectomy, and this was evident across several subgroups.
Association of sedentary work with colon and rectal cancer: systematic review and meta-analysis
Authors: Lee JaeYong , Lee Jongin , Ahn Joonho , Lee Dong-wook , Kim Hyoung-Ryoul , Kang Mo-Yeol
Published: April 2021

Objectives

There has been no research on sedentary behaviour in the occupational domain that occupies a large portion of the daily life.

Methods

We conducted a meta-analysis to investigate the association between sedentary work and colorectal cancer. We searched PubMed, Embase and Cochrane databases up to 12 August 2020 for peer-reviewed journal articles that assessed the association between sedentary work and colon or rectal cancer. Pooled estimates of ORs were obtained using random effects models. Statistical tests for publication bias, heterogeneity and sensitivity analysis were applied.

Results

Of the 5 381 studies initially identified, 23 studies with 64 reports were eligible for inclusion. Sedentary work significantly increased the risk of colon cancer (pooled OR=1.21, 95% CI 1.11 to 1.31, p value ≤0.0001) and rectal cancer (pooled OR=1.08, 95% CI 1.00 to 1.16, p value=0.0395). The adjustment for leisure time physical activity attenuated the association and made the risk estimates non-significant for sedentary behaviour, but the association was independent of sex, control of body mass index and assessment of sedentary behaviour.

Conclusions

We found evidence of association between sedentary work and the risk of colon or rectal cancer. Limiting excessive sedentary work could be an important means of preventing colon and rectal cancer.
Contrasting root and shoot cold tolerance of a conifer with indeterminate growth
Authors: Hawkins Barbara J. , McKeown Kate , Bayne Julia , van der Merwe Lise , Robbins Samantha
Published: April 2021

Yellow-cedar (Callitropsis nootkatensis (D. Don) D.P. Little), a conifer in the Cupressaceae with indeterminate growth, is undergoing severe decline and mortality in southeast Alaska and the coast of northern and central British Columbia. This decline is attributed to cold damage to roots associated with climate warming and reduced snowpack. The cold tolerance of indeterminate conifer species is little studied, and less is known about root cold tolerance, as most studies focus on shoots. We compared the seasonal cycle of cold hardiness in roots and shoots of yellow-cedar seedlings from high- and low-elevation populations over 1 year. Freezing tolerance of shoots followed a typical seasonal cycle, with low levels of cold tolerance observed from April to October and moderate levels of cold tolerance observed in mid-winter. Differences in shoot cold tolerance among populations were consistent with the latitude and elevation of origin. In contrast, at the same freezing temperatures, roots of all seedlings had consistent, high levels of cold damage throughout the year.
The chirality-flow formalism for the standard model
Authors: Alnefjord Joakim , Lifson Andrew , Reuschle Christian , Sjodahl Malin
Published: April 2021

In a recent paper we introduced the chirality-flow formalism, a method for simple and transparent calculations of Feynman diagrams based on the left- and right-chiral $$\mathfrak {sl}(2,\mathbb {C})$$

sl
(
2
,
C
)

nature of spacetime. While our previous work focused on massless QED and QCD at tree-level, we here extend the chirality-flow formalism to the full (tree-level) Standard Model, including massive particles and electroweak interactions – for which the W-interaction simplifies elegantly due to its chiral nature. We illustrate how values of Feynman diagrams can be immediately written down with some representative examples.
Disappearance and reappearance of chaos
Authors: Zhang Bin , Wang Sheng-Jun , Qu Shi-Xian
Published: April 2021

The disappearance and reappearance of chaos by adjusting the internal parameters of dynamics in Lorenz system are studied. We observe monotonous and periodic time-dependent changes of Rayleigh number. There exists relaxation time for the disappearance of chaos, when we use the snapshot attractors to observe the change of the system attractors. We show that the rate of disappearance and reappearance of chaos is positively correlated with the control parameters. To reflect the relaxation phenomenon of chaotic disappearance and the sensitivity of trajectory, the concept of finite-time Lyapunov exponent is used. Then the statistical characteristics of the system can be presented by standard deviation. The chaotic disappearance and reappearance are manifested in the decrease and increase of the standard deviation. The standard deviation decreases continuously during chaotic disappearance, but increases discontinuously during chaotic reappearance. A distinctive scenario is that no matter which parameter changes, when we use the same rate of change in the process of chaotic disappearance and reappearance, their paths are different.
Electronic energy loss assessment in theoretical modeling of primary radiation damage in tungsten
Authors: Cheng Fan , Zheng Qirong , Li Yonggang , Zhang Chuanguo , Zeng Zhi
Published: April 2021

Reliable electronic energy loss needs to be accounted for to accurately estimate primary radiation damage of materials in theory. By introducing four types of electronic stopping cross-sections ([Formula: see text]) into the Monte Carlo (MC) code (IM3D) of collision cascade, and using an object kinetic MC model of short-term defect evolution, we studied the complete process of production and annealing of primary defects in tungsten (W) under high-energy ([Formula: see text] MeV) self-ion and low-energy ([Formula: see text] keV - hundreds keV) neutron-primary knock-on atom (PKA) irradiation. Different [Formula: see text] and their effects were evaluated to accurately estimate primary radiation damage. The difference in electronic energy loss changes the fraction of damage energy, affecting the number of primary defects and their spatial/size distributions. This effect is even pronounced with increasing initial energy, with deviations up to 40% and 60% for damage range and defect number, respectively. The simulation results with [Formula: see text] calculated by time-dependent density functional theory (TDDFT) are quantitatively consistent with experimental damage peaks in self-ion irradiated W and molecular dynamics simulated number of survival defects in neutron-PKA irradiated W. Thus, we recommend using [Formula: see text] calculated by TDDFT to estimate primary radiation damage in W with relative accuracy. It helps understand primary damage behaviors, further accurately simulate long-term defect evolution and predict properties of materials under irradiation.
Measuring node dissimilarity and seeking communities in directed networks via signal copying
Authors: Yang Bo , Huang Tao , Li Xu , Pei Zhiyong , Cheng Weizheng , Huang Xuelin
Published: April 2021

We consider the problem of seeking communities in directed networks. The common approach to this problem has been to simply ignore directions of edges and use algorithms developed for community detection in undirected networks, but this approach discards potentially indispensable information involved in the directions of edges. Here, we introduce an index for node dissimilarity in directed networks in the perspective of dynamics, which are driven by a novel parameter-free signal copying model, to incorporate information contained in the directions of edges. Our dissimilarity index gives a natural fusion between the local and global viewpoints of topological structure of directed networks. Thereby, we apply our index to uncover community structure in directed networks and conduct extensive experiments on synthetic and real-world ones. The results demonstrate that our method outperforms state-of-the-art methods.
Matter versus vacuum oscillations at long-baseline accelerator neutrino experiments
Authors: Bharti Suman , Rahaman Ushak , Sankar S. Uma
Published: April 2021

The neutrino oscillation probabilities at the long-baseline accelerator neutrino experiments are expected to be modified by matter effects. We search for evidence of such modification in the data of T2K and NO[Formula: see text]A, by fitting the data to the hypothesis of (a) matter modified oscillations and (b) vacuum oscillations. We find that vacuum oscillations provide as good a fit to the data as matter modified oscillations. Even extended runs of T2K and NO[Formula: see text]A, with five years in neutrino mode [Formula: see text] and five years in anti-neutrino mode [Formula: see text], cannot make a [Formula: see text] distinction between vacuum and matter modified oscillations. The future experiment DUNE, with neutrino and anti-neutrino runs of five years each [Formula: see text], can rule out vacuum oscillations by itself at [Formula: see text] if the hierarchy is normal. If the hierarchy is inverted, a [Formula: see text] discrimination against vacuum oscillations requires the combination of [Formula: see text] runs of T2K, NO[Formula: see text]A and DUNE.
Novel solitary and resonant multi-soliton solutions to the (3 + 1)-dimensional potential-YTSF equation
Authors: Kuo Chun-Ku , Chen Ying-Chung , Wu Chao-Wei , Chao Wei-Nan
Published: April 2021

In this study, the (3 + 1)-dimensional potential-Yu–Toda–Sasa–Fukuyama equation arising from the (3 + 1)-dimensional Kadomtsev–Petviashvili equation is investigated in detail by using two powerful approaches. First, the generalized resonant multi-soliton solution is generated via the simplified linear superposition principle. Second, after applying the simplest equation method, the generalized single solitary solution is extracted. The results show that the obtained solutions are perfect. The physical explanation of the obtained solutions is depicted in various 3D and 2D figures, which are used to illustrate that the interactions of resonant multi-soliton waves are inelastic. Ultimately, the study reveals that the inelastic interactions can be determined by the sign of the wave related number [Formula: see text].
FROM BID-ASK CREDIT DEFAULT SWAP QUOTES TO RISK-NEUTRAL DEFAULT PROBABILITIES USING DISTORTED EXPECTATIONS
Authors: MICHIELON MATTEO , KHEDHER ASMA , SPREIJ PETER
Published: April 2021

Risk-neutral default probabilities can be implied from credit default swap (CDS) market quotes. In practice, mid-CDS quotes are used as inputs, as their risk-neutral counterparts are not observable. We show how to imply risk-neutral default probabilities from bid and ask quotes directly by means of formulating the CDS calibration problem to bid and ask market quotes within the conic finance framework. Assuming the risk-neutral distribution of the default time to be driven by a Poisson process we prove, under mild liquidity-related assumptions, that the calibration problem admits a unique solution that also allows to jointly calculate the implied liquidity of the market.
Invasive-invaded system of non-Lipschitz porous medium equations with advection
Authors: Palencia José Luis Díaz
Published: April 2021

This work provides analytical results towards applications in the field of invasive-invaded systems modeled with nonlinear diffusion and with advection. The results focus on showing regularity, existence and uniqueness of weak solutions using the condition of a nonlinear slightly positive parabolic operator and the reaction-absorption monotone properties. The coupling in the reaction-absorption terms, that characterizes the species interaction, impedes the formulation of a global comparison principle that is shown to exist locally. Additionally, this work provides analytical solutions obtained as selfsimilar minimal and maximal profiles. A propagating diffusive front is shown to exist until the invaded specie notes the existence of the invasive. When the desertion of the invaded starts, the diffusive front vanishes globally and the nonlinear diffusion concentrates only on the propagating tail which exhibits finite speed. Finally, the invaded specie is shown to exhibit an exponential decay along a characteristic curve. Such exponential decay is not trivial in the nonlinear diffusion case and confirms that the invasive continues to feed on the invaded during the desertion.
Fault-tolerant metric dimension of two-fold heptagonal-nonagonal circular ladder
Authors: Sharma Sunny Kumar , Bhat Vijay Kumar
Published: April 2021

The problem of characterizing the classes of plane graphs with the bounded metric dimension, edge metric dimension, and fault-tolerant metric dimension is of great interest nowadays. In this paper, we study the metric dimension, the fault-tolerant metric dimension, and the edge metric dimension of a two-fold heptagonal-nonagonal circular ladder (denoted by [Formula: see text]). We show that the metric dimension and the edge metric dimension of [Formula: see text] are the same. We also study its fault-tolerant metric dimension and prove that the metric basis and the edge metric basis sets are independent.
Graphs with constant adjacency dimension
Authors: Jannesari Mohsen
Published: April 2021

For a set [Formula: see text] of vertices and a vertex [Formula: see text] in a graph [Formula: see text], the [Formula: see text]-vector [Formula: see text] is the adjacency representation of [Formula: see text] with respect to [Formula: see text], where [Formula: see text] and [Formula: see text] is the minimum of [Formula: see text] and the distance between the vertices [Formula: see text] and [Formula: see text]. The set [Formula: see text] is an adjacency resolving set for [Formula: see text] if distinct vertices of [Formula: see text] have distinct adjacency representations with respect to [Formula: see text]. The minimum cardinality of an adjacency resolving set for [Formula: see text] is its adjacency dimension. It is clear that the adjacency dimension of an [Formula: see text]-vertex graph [Formula: see text] is between [Formula: see text] and [Formula: see text]. The graphs with adjacency dimension [Formula: see text] and [Formula: see text] are known. All graphs with adjacency dimension [Formula: see text], and all [Formula: see text]-vertex graphs with adjacency dimension [Formula: see text] are studied in this paper. In terms of the diameter and order of [Formula: see text], a sharp upper bound is found for adjacency dimension of [Formula: see text]. Also, a sharp lower bound for adjacency dimension of [Formula: see text] is obtained in terms of order of [Formula: see text]. Using these two bounds, all graphs with adjacency dimension 2, and all [Formula: see text]-vertex graphs with adjacency dimension [Formula: see text] are characterized.
Using Economic Optimization to Derive Site-Specific Treatment Objectives
Authors: Tamblyn David Rodger
Published: April 2021

A procedure to estimate the economically efficient site- or system-specific treatment objective for enteric viruses in drinking water is presented. The health benefits of treatment are estimated using an existing quantitative microbiological risk assessment model for Rotavirus, which yields a reduction in burden of disease, measured in DALYs. The community’s willingness to pay for this reduced disease burden is then inferred using an estimate of the value of an avoided DALY from the literature. Economically efficient treatment occurs where the marginal cost of additional treatment equals the marginal benefit in terms of willingness to pay for avoided illness. In a case study on a small water system, capital and operating costs are estimated for four alternative treatment levels using commercially available UV disinfection systems. The case study results compare the economically efficient virus disinfection level, risk of infection, and burden of disease to international guidelines. A sensitivity analysis suggests that source water quality, population served, and the dose–response model are key inputs. Site-specific treatment objectives offer a viable alternative to prescribed national standards while respecting water safety and local autonomy.
“It Must Include Rules”
Authors: Wiese Eliane S. , Linn Marcia C.
Published: April 2021

When middle school students encounter computer models of science phenomenon in science class, how do they think those computer models work? Computer models operationalize real-world behaviors of selected variables, and can simulate interactions between the modeled elements through programmed instructions. This study explores how middle school students think about the high-level semantic meaning of those instructions, which we term
rules
. To investigate this aspect of students’ computational thinking, we developed the Computational Modeling Inventory and administered it to 253 7
th
grade students. The Inventory included three computer models that students interacted with during the assessment. In our sample, 99% of students identified at least one key rule underlying a model, but only 14% identified all key rules; 65% believed that model rules can contradict; and 98% could not distinguish between emergent patterns and behaviors that directly resulted from model rules. Despite these misconceptions, compared to the “typical” questions about the science content alone, questions about model rules elicited deeper science thinking, with 2--10 times more responses including reasoning about scientific mechanisms. These results suggest that incorporating computational thinking instruction into middle school science courses might yield deeper learning and more precise assessments around scientific models.
Two-factor Password-authenticated Key Exchange with End-to-end Security
Authors: Jarecki Stanislaw , Jubur Mohammed , Krawczyk Hugo , Saxena Nitesh , Shirvanian Maliheh
Published: April 2021

We present a secure two-factor authentication (TFA) scheme based on the user’s possession of a password and a crypto-capable device. Security is “end-to-end” in the sense that the attacker can attack all parts of the system, including all communication links and any subset of parties (servers, devices, client terminals), can learn users’ passwords, and perform active and passive attacks, online and offline. In all cases the scheme provides the highest attainable security bounds given the set of compromised components. Our solution builds a TFA scheme using any Device-enhanced Password-authenticated Key Exchange (PAKE), defined by Jarecki et al., and any Short Authenticated String (SAS) Message Authentication, defined by Vaudenay. We show an efficient instantiation of this modular construction, which utilizes any password-based client-server authentication method, with or without reliance on public-key infrastructure. The security of the proposed scheme is proven in a formal model that we formulate as an extension of the traditional PAKE model. We also report on a prototype implementation of our schemes, including TLS-based and PKI-free variants, as well as several instantiations of the SAS mechanism, all demonstrating the practicality of our approach. Finally, we present a usability study evaluating the viability of our protocol contrasted with the traditional PIN-based TFA approach in terms of efficiency, potential for errors, user experience, and security perception of the underlying manual process.1
Perspectives on Allele-Specific Expression
Authors: Cleary Siobhan , Seoighe Cathal
Published: April 2021

Diploidy has profound implications for population genetics and susceptibility to genetic diseases. Although two copies are present for most genes in the human genome, they are not necessarily both active or active at the same level in a given individual. Genomic imprinting, resulting in exclusive or biased expression in favor of the allele of paternal or maternal origin, is now believed to affect hundreds of human genes. A far greater number of genes display unequal expression of gene copies due to cis-acting genetic variants that perturb gene expression. The availability of data generated by RNA sequencing applied to large numbers of individuals and tissue types has generated unprecedented opportunities to assess the contribution of genetic variation to allelic imbalance in gene expression. Here we review the insights gained through the analysis of these data about the extent of the genetic contribution to allelic expression imbalance, the tools and statistical models for gene expression imbalance, and what the results obtained reveal about the contribution of genetic variants that alter gene expression to complex human diseases and phenotypes.
First-Principles Investigation of Electronic Structure and Energy Level Scheme of Phosphors: The Lanthanide-Doped Sr2P2O7
Authors: Yu Jinying , Fan Yufan , Wu Lina , Sun Bei , Wu Yelong
Published: April 2021

Using screened hybrid density functional theory (HSE06), the electronic structure, character of electronic transition and energy level scheme of lanthanide (Ln)-doped Sr2P2O7 are systematically investigated. Both Ln2+ and Ln3+ dopants are considered. It is found that, owing to the doping of Ln2+/3+ ions, some extra Ln 4 f and 5d states are introduced in the host Sr2P2O7 band gap, causing a change in the electronic structures and the luminescence properties. The specific locations of the Ln 4 f and 5d states and the possibility of electronic transitions, especially the 4 f → 5d, are systematically studied. The energy level scheme is constructed from the calculated electronic structures, and it fits well with the experimental scheme. This work gives a whole picture of the Ln doping effect on the materials. It can be applied to all Ln-doped fluorescent materials and to aid in the discovery of new bright scintillator materials.
An examination of a potential organized motor unit firing rate and recruitment scheme of an antagonist muscle during isometric contractions
Authors: Reece Tanner M. , Herda Trent J.
Published: April 2021

This is the first study to explore a potential motor unit control scheme and quantify changes in firing rates with increasing intensity of an antagonist muscle during isometric contractions. We demonstrate that the antagonist muscle possesses an organized motor unit firing rate and recruitment scheme similar to the agonist muscle during isometric forearm flexion, but unlike the agonist muscle, there was no significant increase in firing rates from a moderate- to higher-intensity isometric contraction.
Classic Hebbian learning endows feed-forward networks with sufficient adaptability in challenging reinforcement learning tasks
Authors: Burns Thomas F.
Published: April 2021

A common pitfall of current reinforcement learning agents implemented in computational models is in their inadaptability postoptimization. Najarro and Risi [Najarro E, Risi S. Proc 33rd Conf Neural Inf Process Systems (NeurIPS 2020). 2020: 20719–20731, 2020] demonstrate how such adaptability may be salvaged in artificial feed-forward networks by optimizing coefficients of classic Hebbian rules to dynamically control the networks’ weights instead of optimizing the weights directly. Although such models fail to capture many important neurophysiological details, allying the fields of neuroscience and artificial intelligence in this way bears many fruits for both fields, especially when computational models engage with topics with a rich history in neuroscience such as Hebbian plasticity.
ECLB: Edge-Computing-Based Lightweight Blockchain Framework for Mobile Systems
Authors: Xie Qingqing , Dong Fan , Feng Xia
Published: April 2021

The blockchain technology achieves security by sacrificing prohibitive storage and computation resources. However, in mobile systems, the mobile devices usually offer weak computation and storage resources. It prohibits the wide application of the blockchain technology. Edge computing appears with strong resources and inherent decentralization, which can provide a natural solution to overcoming the resource-insufficiency problem. However, applying edge computing directly can only relieve some storage and computation pressure. There are some other open problems, such as improving confirmation latency, throughput, and regulation. To this end, we propose an edge-computing-based lightweight blockchain framework (ECLB) for mobile systems. This paper introduces a novel set of ledger structures and designs a transaction consensus protocol to achieve superior performance. Moreover, considering the permissioned blockchain setting, we specifically utilize some cryptographic methods to design a pluggable transaction regulation module. Finally, our security analysis and performance evaluation show that ECLB can retain the security of Bitcoin-like blockchain and better performance of ledger storage cost in mobile devices, block mining computation cost, throughput, transaction confirmation latency, and transaction regulation cost.
Image Recognition of Crop Diseases and Insect Pests Based on Deep Learning
Authors: Xin Mingyuan , Wang Yong
Published: April 2021

Deep learning algorithms have the advantages of clear structure and high accuracy in image recognition. Accurate identification of pests and diseases in crops can improve the pertinence of pest control in farmland, which is beneficial to agricultural production. This paper proposes a DCNN‐G model based on deep learning and fusion of Google data analysis, using this model to train 640 data samples, and then using 5000 test samples for testing, selecting 80% as the training set and 20% as the test set, and compare the accuracy of the model with the conventional recognition model. Research results show that after degrading a quality level 1 image using the degradation parameters above, 9 quality level images are obtained. Use YOLO’s improved network, YOLO‐V4, to test and validate images after quality level classification. Images of different quality levels, especially images of adjacent levels, are subjectively observed by human eyes, and it is difficult to distinguish the quality of the images. Using the algorithm model proposed in this article, the recognition accuracy is 95%, which is much higher than the basic 84% of the DCNN model. The quality level classification of crop disease and insect pest images can provide important prior information for the understanding of crop disease and insect pest images and can also provide a scientific basis for testing the imaging capabilities of sensors and objectively evaluating the image quality of crop diseases and pests. The use of convolutional neural networks to realize the classification of crop pest and disease image quality not only expands the application field of deep learning but also provides a new method for crop pest and disease image quality assessment.
Numerical Performance Investigation of Parabolic Dish Solar-Assisted Cogeneration Plant Using Different Heat Transfer Fluids
Authors: Khan Muhammad Sajid , Abid Muhammad , Amber Khuram Pervez , Ali Hafiz Muhammad , Yan Mi , Javed Samina
Published: April 2021

Parabolic dish solar collectors gain higher solar to thermal conversion efficiency due to their maximum concentration ratio. The present research focuses by integrating the parabolic dish solar collector to the steam cycle producing power and rate of process heating. Pressurized water, therminol VP1, and supercritical carbon dioxide are the examined working fluids in the parabolic dish solar collector. The aim of the current research is to observe the optimal operating conditions for each heat transfer fluid by varying inlet temperature and flow rate of the working fluid in the parabolic dish solar collector, and combination of these parameters is predicted to lead to the maximum energy and exergy efficiencies of the collector. The operating parameters are varied to investigate the overall system efficiencies, work output, and process heating rate. Findings of the study declare that water is an efficient heat transfer fluid at low temperature levels, whereas therminol VP1 is effective for a higher temperature range. The integrated system efficiencies are higher at maximum flow rates and low inlet temperatures. The efficiency map of solar collector is located at the end of study, and it shows that maximum exergy efficiency gains at inlet temperature of 750 K and it is observed to be 37.75%.