bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimising growth in very preterm infants: reviewing the evidence
Authors: Young Aneurin , Beattie R Mark , Johnson Mark John
Published: February 2022

Infants born before 32 weeks’ postmenstrual age are at a high risk of growth failure. International guidelines have long recommended that they match the growth of an equivalent fetus, despite the challenges posed by ex utero life and comorbidities of prematurity. Several groups have recently questioned the necessity or desirability of this target, shifting attention to aiming for growth which optimises important long-term outcomes. Specifically, recent research has identified the neurodevelopmental benefits of enhanced growth during the neonatal period, but work in term infant suggests that rapid growth may promote the metabolic syndrome in later life. In this context, defining a pattern of growth which optimises outcomes is complex, controversial and contested. Even if an optimal pattern of growth can be defined, determining the nutritional requirements to achieve such growth is not straightforward, and investigations into the nutritional needs of the very preterm infant continue. Furthermore, each infant has individual nutritional needs and may encounter a number of barriers to achieving good nutrition. This article offers a narrative review of recent evidence for the competing definitions of optimal growth in this cohort. It examines recent advances in the determination of macronutrient and micronutrient intake targets along with common barriers to achieving good nutrition and growth. Finally, key implications for clinical practice are set out and a recommendation for structured multidisciplinary management of nutrition and growth is illustrated.
Atypical presentation of acquired tracheo-oesophageal fistula in an adolescent girl with pulmonary tuberculosis
Authors: Khan Afreen , Chakravarty Aparna , Naqishbandi Rizwan , Qamar Sumbul
Published: February 2022

We report a case of an adolescent girl presenting with acute respiratory distress syndrome (ARDS) requiring mechanical ventilation. Initial presentation during the ongoing COVID-19 pandemic was compatible with multisystem inflammatory response in children associated with COVID-19 (MIS-C). Subsequently a diagnosis of tuberculosis was made. During ventilation, she developed significant abdominal distension which was not relieved with nasogastric decompression. There was a high index of suspicion of bronchoenteric fistula. Bronchoscopy with adjunct oesophagoscopy demonstrated tracheo-oesophageal fistula (TEF). The classical presentation of TEF has been masked by onset of ARDS. During the pandemic the diagnosis of tuberculosis in high-burden countries decreased for multiple reasons leading to development of complications which are often confused with MIS-C. While diagnosing MIS-C, maintaining a high level of suspicion for concomitant or alternative aetiologies is essential.
Safe surgical hip dislocation for acetabular osteoid osteoma excision
Authors: Tripathy Sujit , Varghese Paulson , Sethy Siddharth Sekhar , Agrawal Kanhaiyalal
Published: February 2022

Excision of acetabular osteoid osteoma is technically difficult. We report osteoid osteoma of the quadrilateral plate in a 9-year-old girl who presented to us with persistent nocturnal pain, limp and restricted hip joint movement. The child was investigated with CT scan, MRI and triple-phase bone scan. The 0.7 cm nidus was located in the central portion of the cancellous bone in the quadrilateral plate, 1.94 cm inferior to the triradiate cartilage. The child was operated on through the safe surgical dislocation of the left hip. The location of the lesion was gauged from the preoperative CT scan measurement data and intraoperative fluoroscopic aid. The nidus with a sclerotic rim was burred down completely. Postoperative X-ray and CT scan revealed complete excision of the tumour, and the patient was pain-free. At 18 months follow-up, the patient is completely asymptomatic and walking normally.
Cystic biliary atresia in a neonate with antenatally detected abdominal cyst
Authors: Rahamtalla Dafalla , Al Rawahi Yusriya , Jawa Zabah Muhammad , Wali Yasser
Published: February 2022

Cystic biliary atresia (BA) is a rare but an important type of BA. An antenatally detected cystic lesion at the porta hepatis raises the suspicion of cystic BA. It is very important to differentiate this from choledochal cyst in infants with cholestasis and cystic lesions. This case report outlines the clinical presentation and radiological findings of an infant who had an antenatally detected intra-abdominal cystic mass, thought to be a choledochal cyst.
Variable presentations ofGCKgene mutation in a family
Authors: Oza Chirantap Markand , Karguppikar Madhura Bharat , Khadilkar Vaman , Khadilkar Anuradha
Published: February 2022

We describe siblings born from non-consanguineous parents, with older sibling having asymptomatic hyperglycaemia while younger sibling presented with low birth weight and persistent hyperglycaemia from first month of life. Our case, the older sibling was heterozygous for paternally inheritedGCKpathogenic variant resulting in diabetes of maturity-onset in the young (MODY) manifested as mild fasting hyperglycaemia.GCKgene sequencing revealed that the younger sibling was compound heterozygous for missense mutations (two) combined in a novelGCK-permanent neonatal diabetes mellitus (PNDM) genotype. Thus, heterozygous inactivatingGCKmutations are likely to lead to maturity-onset diabetes of the young type 2 (MODY 2) and the homozygous inactivating or compound heterozygousGCKmutations are a cause of PNDM.
Non-gestational uterine choriocarcinoma inside a leiomyoma: importance of early suspicion in prognosis
Authors: Coutinho Filipa Mendes , Raposo Sofia , Carvalho Teresa , Sousa Rita
Published: February 2022

Uterine choriocarcinoma is a trophoblastic neoplasm most commonly related to pregnancy. However, there are already cases of non-gestational uterine choriocarcinoma (NGC) described in literature. The difficult diagnosis may delay treatment and threaten patient survival. We report the case of a 37-year-old patient presenting with abnormal haemorrhage and moderate levels of beta-human chorionic gonadotropin (β-hCG). As imaging exams did not show any suspicious site for the origin, choriocarcinoma was not considered so the treatment was delayed. Anatomopathological diagnosis was given both from the surgical sample of hysterectomy and from a skin lesion. The lesion was discovered inside a myoma. At this point, β-hCG levels were substantially high and she presented with respiratory distress due to pulmonary metastasis. The patient was transferred to an intensive care unit and underwent mechanical ventilation as well as life-saving chemotherapy. At 10 months after diagnosis, she is well and in remission. The delay from not suspecting the diagnosis was almost fatal for the patient.
Delayed onset of neurogenic pulmonary oedema following an evolving ischaemic stroke
Authors: Liarakos Alexandros Leonidas , Tran Patrick
Published: February 2022

Any insult to the central nervous system can lead to the rare occurrence of neurogenic pulmonary oedema (NPO). It is usually associated with significant neurological injury (eg, subarachnoid haemorrhage or traumatic brain injury) with a relatively rapid onset. As an exception to this observation, we report a middle-aged woman who developed NPO 72 hours after the onset of a subtle but evolving right middle cerebral artery infarction confirmed on CT. Aggressive use of diuretics and vasodilators, as is normally the case for cardiogenic pulmonary oedema, can compromise cerebral blood flow and the ischaemic penumbra. This case illustrates how the diagnostic and therapeutic challenges were successfully addressed with the aid of bedside ultrasonography and close haemodynamic monitoring to reverse the respiratory failure while protecting the brain.
Single Leaflet Device Attachment
Authors: Zhang Yixin , Kogler William , Sattiraju Srinivasan
Published: February 2022

We present a 61-year-old man with severe primary mitral valve insufficiency who underwent MitraClip procedure without any immediate complications, although it was a difficult attachment requiring multiple attempts. He was then found to have single leaflet device attachment 5 weeks later with excessive mobility of the mitral clip. No urgent intervention was done as patient remained stable without any new symptoms. This case demonstrated the importance of postprocedural imaging follow-up for patient with MitraClips.
Endoscopic transabdominal cervical cerclage replacement after recurrent late miscarriage
Authors: Hirsch Martin , Reisel Dan , Saridogan Ertan , David Anna L
Published: February 2022

Transabdominal cerclage (TAC) is a recognised treatment for recurrent spontaneous late miscarriage or preterm birth due to cervical weakness. This can be performed via an open procedure before and during pregnancy, or a laparoscopic technique preconception. Complications include cerclage failure and suture migration. We present a case highlighting these complications where laparoscopic removal of an open TAC and replacement led to two successful term deliveries. A woman in her thirties with a fibroid uterus, adenomyosis and a history of three spontaneous mid-trimester losses, had an open TAC at 13 weeks of gestation. Preterm premature rupture of the membranes occurred shortly after and at 18 weeks of gestation she underwent surgical evacuation of the uterus. Subsequent hysteroscopy confirmed migration of the cerclage through the cervical canal. We demonstrate the application of endoscopic gynaecological surgery to remove and replace the TAC with two successful term births by Caesarean section in the ensuing pregnancies.
Venous thrombosis via pulmonary arteriovenous malformation causing acute myocardial infarction in a relatively young female patient
Authors: Goto China , Yatsu Shoichiro , Wada Hideki , Suwa Satoru
Published: February 2022

Pulmonary arteriovenous malformation (PAVM) is a probable cause of thromboembolic diseases such as acute myocardial infarction (MI); however, few cases have been reported. A woman in her early 40s developed acute-onset chest pain; an ECG showed ST-elevated MI. Emergency catheter angiography showed that the culprit lesion was a thrombus that was treated successfully with aspiration. She had a history of deep venous thrombosis and CT revealed PAVM. It was likely that the venous thrombus had moved into the coronary artery through the PAVM. Catheter embolisation of the PAVM was performed and she did not experience any other cardiac event until 6 months after embolisation.
Case of unilateral anaemic retinopathy unmasking colorectal carcinoma
Authors: Toh Zhi Hong , Chin Chee Fang , Gan Nicola Yi’an
Published: February 2022

Anaemic retinopathy presents commonly with bilateral retinal haemorrhages and soft exudates. Unilateral optic disc oedema in these patients has rarely been mentioned. We report a case of an atypical presentation of anaemic retinopathy with recurrent unilateral optic disc oedema and retinal haemorrhages secondary to iron deficiency anaemia from a newly diagnosed colorectal adenocarcinoma.

A man in his 70s with multiple ischaemic risk factors was referred for unilateral optic disc oedema associated with a few retinal haemorrhages. Initial diagnosis was that of impending central retinal vein occlusion. The optic disc oedema initially resolved but recurred 8 months later with worsening unilateral disc oedema, ‘coin-shaped’ retinal haemorrhages, Roth’s spots and venous tortuosity. Full blood count showed microcytic hypochromic anaemia secondary to iron deficiency and colonoscopy revealed colorectal adenocarcinoma. The patient received blood transfusions, oral iron replacement and underwent surgical resection of the tumour. The anaemia resolved, and the fundus findings resolved as well.
Enhanced depth imaging optical coherence tomography of the optic nerve head improves correct diagnosis in glaucoma suspects without glaucomatous optic disc morphology
Authors: Ahmadi Hamid , Kolko Miriam , Hamann Steffen
Published: February 2022

An 83-year-old woman with a long history of glaucoma and optic disc drusen (ODD) was referred for neuro-ophthalmological second opinion. The patient had been treated for decades with bilateral intraocular pressure (IOP)-lowering eye drops, laser trabeculoplasty and trabeculectomy and had severe, bilateral loss of visual fields and retinal nerve fibre layer (RNFL) thinning on optical coherence tomography (OCT) despite IOP that never exceeded 24 mm Hg. On ophthalmoscopy, only a single ODD was visible in the left eye and no optic disc cupping was apparent in either eye. Enhanced depth imaging OCT (EDI-OCT) of the optic nerve head revealed bilateral multiple, large, deep ODD, which in itself could easily explain the visual field loss and RNFL thinning of this patient. Optic nerve head examination using EDI-OCT is highly recommended for patients with a history of glaucoma but without optic nerve head cupping to avoid a potential misdiagnosis with consequent unnecessary treatment.
Social capital and geographical variation in the incidence of COVID-19: an ecological study
Authors: Saville Christopher W N , Thomas Daniel Rhys
Published: February 2022

Background

The new behavioural norms needed to reduce the spread of COVID-19 are likely scaffolded by social capital. Research on social capital and COVID-19 has yielded mixed results, with some studies finding it to be protective while others identifying it as a risk factor. We examined the association between social capital and COVID-19 at a finer spatial scale than previous research, and examined changes in the relationship over the course of the pandemic.

Methods

Routine COVID-19 surveillance data from Wales were linked to estimates of social capital at a small area level. Generalised linear mixed effects models predicting COVID-19 case rates across areas using social capital estimates and possible confounding variables were fitted to the data. A moving window version of the analysis explored whether this relationship varied across time.

Results

Areas with higher levels of social capital had lower rates of COVID-19 (rate ratio for trust=0.94, 95% CI 0.92 to 0.96; rate ratio for belonging=0.94, 95% CI 0.92 to 0.96). These associations were strongest during periods of lockdown, with evidence that social capital was less protective, and potentially even a risk factor, during periods when restrictions were eased. Trust, but not belonging, remained protective after adjusting for deprivation, population density, ethnicity and proportion population aged over 65 years.

Conclusions

Social capital is an important public health resource, which should be considered in future pandemic preparedness. Its importance may be greatest during times when social activity is most restricted.
Occupational health, frontline workers and COVID-19 lockdown: new gender-related inequalities?
Authors: Utzet Mireia , Bacigalupe Amaia , Navarro Albert
Published: February 2022

Introduction

The abrupt onset of COVID-19, with its rapid spread, has had brutal consequences in all areas of society, including the workplace. In this paper, we report the working conditions, health, and tranquilisers and opioid analgesics use of workers during the first months of the ensuing pandemic, according to whether they were frontline workers or not and also according to sex.

Methods

Our analysis is based on cross-sectional survey data (collected during April and May 2020) from the wage-earning population in Spain (n=15 070). We estimate prevalences, adjusted prevalence differences and adjusted prevalence ratios by sex and according to whether the worker is a frontline worker or not.

Results

Employment and working conditions, exposure to psychosocial risks, as well as health status and the consumption of tranquilisers and opioid analgesics all showed sex and sectoral (frontline vs non-frontline) inequalities, which placed essential women workers in a particularly vulnerable position. Moreover, the consumption of tranquilisers and opioid analgesics increased during the pandemic and health worsened significantly among frontline women workers.

Conclusions

The exceptional situation caused by the COVID-19 pandemic provides an opportunity to revalue essential sectors and to dignify such employment and working conditions, especially among women. There is an urgent need to improve working conditions and reduce occupational risk, particularly among frontline workers. In addition, this study highlights the public health problem posed by tranquilisers and opioid analgesics consumption, especially among frontline women.
Homozygous variants inAKAP3induce asthenoteratozoospermia and male infertility
Authors: Liu Chunyu , Shen Ying , Tang Shuyan , Wang Jiaxiong , Zhou Yiling , Tian Shixiong , Wu Huan , Cong Jiangshan , He Xiaojin , Jin Li , Cao Yunxia , Yang Yihong , Zhang Feng
Published: February 2022

Background

As a common type of asthenoteratozoospermia, multiple morphological abnormalities of the sperm flagella (MMAF) can cause male infertility. Previous studies have revealed genetic factors as a major cause of MMAF. The known MMAF-associated genes are involved in the mitochondrial sheath, outer dense fibre or axoneme of the sperm flagella. These findings indicate the genetic heterogeneity of MMAF.

Methods and results

Here, we conducted genetic analyses using whole-exome sequencing in a cohort of 150 Han Chinese men with asthenoteratozoospermia. Homozygous deleterious variants ofAKAP3(A-kinase anchoring protein 3) were identified in two MMAF-affected men from unrelated families. OneAKAP3variant was a frameshift (c.2286_2287del, p.His762Glnfs*22) and the other variant was a missense mutation (c.44G>A, p.Cys15Tyr), which was predicted to be damaging by multiple bioinformatics tools. Further western blotting and immunofluorescence assays revealed the absence of AKAP3 in the spermatozoa from the man harbouring the homozygous frameshift variant, whereas the expression of AKAP3 was markedly reduced in the spermatozoa of the man with theAKAP3missense variant p.Cys15Tyr. Notably, the clinical outcomes after intracytoplasmic sperm injection (ICSI) were divergent between these two cases, suggesting a possibility of AKAP3 dosage-dependent prognosis of ICSI treatment.

Conclusions

Our study revealedAKAP3as a novel gene involved in human asthenoteratozoospermia.
Household use of crop residues and fuelwood for cooking and newborn birth size in rural Bangladesh
Authors: Lee Mi-Sun , Eum Ki-Do , Golam Mostofa , Quamruzzaman Quazi , Kile Molly L , Mazumdar Maitreyi , Christiani David C
Published: February 2022

Objectives

We aimed to investigate the association between type of cooking biomass fuels (crop residues vs fuelwood) and newborn birth outcomes in Bangladeshi children.

Methods

In this birth cohort study, pregnant women who were 18 years or older with ultrasound confirmed singleton pregnancy of ≤16 weeks of gestation were enrolled from two Bangladesh clinics between January 2008 and June 2011. Exposure to cooking biomass fuels during pregnancy was assessed by an administered questionnaire. The newborn size metrics were measured at the time of delivery. We used multiple linear regression and logistic regression to assess the associations between the type of cooking biomass fuels and birth outcomes after adjusting for covariates.

Results

A total of 1137 participants were using biomass fuels, including crop residues (30.3%) and fuelwood (69.7%), respectively, for cooking. After adjusting for covariates, the use of crop residues for cooking was associated with a 0.13 SD decrease in birth length (95% CI 0.25 to −0.01), a 0.14 SD decrease in head circumference (95% CI −0.27 to –0.02), and increased risk of low birth weight (LBW, OR 1.52, 95% CI 1.07 to 2.15) compared with the use of fuelwood.

Conclusion

The use of crop residues for cooking was associated with reduced birth size and increased risk for LBW in Bangladeshi children, implying that the use of crop residues during pregnancy may have a detrimental effect on fetal growth.
Synthesis, molecular docking, and in silico ADME studies of dihydropyrimidine derivatives using tetrabutylphosphonium methanesulphonate ionic liquid as a catalyst under solvent-free conditions
Authors: Tantray Aafaq A. , Rode Nitin R. , Terdale Santosh S.
Published: February 2022

This paper describes the synthesis and characterization of tetrabutylphosphonium methanesulphonate ionic liquid and its use for the first time as a catalyst in a multicomponent reaction for one-pot synthesis of dihydropyrimidine derivatives from various aromatic aldehydes, methyl or ethyl acetoacetate, and urea or thio-urea under solvent-free conditions at 120 °C. About 21 different dihydropyrimidine derivatives have been synthesized in excellent yields. The advantages of this method are the following: solvent-free conditions, a small amount of catalyst required, shorter reaction time, easy workup procedure, and no hazardous organic solvents or toxic catalysts. This catalyst was easily prepared and showed an excellent level of reusability. The molecular docking study was performed to evaluate interactions between the active compounds with Leishmania pteridine reductase 1 (PTR1). Using theoretical evaluation, ADME properties in silico were investigated for their oral bioavailability to predict the safer efficacy of the synthesized compounds.
Classical versus quantum calculation of radiative electric quadrupole transition rates for hydrogenic states
Authors: Horbatsch Michael , Horbatsch Marko
Published: February 2022

The semiclassical Kepler–Coulomb problem and the quantum-mechanical Schrödinger–Coulomb problem were compared for their predictions of quadrupole E2 transitions. The semiclassical treatment involved an extension of a previous work for electric dipole transitions (Horbatsch et al. Phys. Rev. A, 71, 020501. doi: 10.1103/PhysRevA.71.020501), and rates were derived for Δ ℓ = 0, ±2 transitions on the basis of the multipolar properties of the emitted radiation. For the quantum case, a derivation was presented within the Schrödinger framework without reference to spin. Comparison of the E2 rates showed reasonable agreement, but not as good as was found for the electric dipole case.
Thwarting Cache Side Channel Attacks with Encryption Address-Based Set Balance Cache
Authors: Wang Chong , Wei Shuai , Song Ke , Zhang Fan
Published: February 2022

The deterministic memory-to-cache mapping used by cache side channel attack causes the leakage of sensitive information such as secret keys, which seriously threatens user security and highlights the need to defend against this kind of attack. Recent table-based secure cache design requires more space to store the entry while a purely encryption-based design needs complex encryption units to ensure robustness. What is more, the newer attack algorithm enabling faster eviction set discovery may still break such defenses. Even though increasing the association of cache can be a potential solution, it introduces too much redundancy cache access and storage overhead. In this paper, we eliminate this problem. We present Encryption address-based Set Balance Cache (ESBC), a novel cache design to mitigate cache-based side channel attack. ESBC encrypts an address into two-level sets and displaces the data from a primary set into the secondary set when the primary set is full. The two-level mapping structure increases the complexity for attackers to build eviction sets, which is a vital step for the conflict-based attack. Furthermore, we adopt two different optimized variants from a temporal perspective, ESBC with remapping (ESBCR), which serves dynamic-remapping, and spatial perspective, ESBC with multi-mapping (ESBCM), which performs multi-mapping to improve the robustness. Our security analysis reveals that these designs can confuse the exploitation of conflicting addresses. Simulation-based evaluation on SPEC2017 shows 0.24% instruction per cycle (IPC) degradation for ESBCR with 1% remap rate. While the reduction of ESBCM that has five potential secondary sets is 0.69%. What is exciting is that both miss per kilo instructions (MPKI) and miss rates are even reduced because of the efficient cache usage. The storage overhead of these two variants is only 0.87%. By comparing the two schemes, we can observe that though ESBCR brings less performance overhead, the ESBCM has better scalability.
The new frontiers of gravitational microlensing
Authors: Dominik M.
Published: February 2022

Albert Einstein referred to gravitational microlensing as a “most curious effect”, and while its underlying principles are intriguingly simple, their universality makes a powerful tool for inferring information about a wide range of astronomical bodies. Much has happened since the first observation of a gravitational microlensing event in 1992, and the frontiers have shifted. What we did not dare dreaming about just a few decades ago turned into reality, and we have not reached the end of the journey. New challenges and opportunities lie ahead. Where might we be able to go and how can we get there?
CHARACTERISTIC ANALYSIS OF FRACTIONAL-ORDER RLC CIRCUIT BASED ON THE CAPUTO–FABRIZIO DEFINITION
Authors: LIAO XIAOZHONG , YU DONGHUI , LIN DA , RAN MANJIE , XIA JINHUI
Published: February 2022

The Caputo–Fabrizio (C–F) definition, which solves the singularity problem in the Caputo definition, has been preliminarily applied in the field of circuit system modeling. However, the complex characteristics of the C–F definition-based circuit systems are still understudied. Therefore, this paper proposes a C–F definition-based fractional-order RLC (CF-FORLC) circuit model and analyzes its basic characteristics. First, the effects of different component orders on the performance parameters including the impedance, quality factor, and bandwidth are analyzed, which gives insights into the design of CF-FORLC. Then, the analytical solutions and the frequency-domain characteristics of CF-FORLC with different capacitance and inductance orders under arbitrary input are derived. Finally, the data of actual circuits are fitted to obtain the parameters of the CF-FORLC model, and the orders of the C–F definition-based capacitors and inductors are estimated. The results of the comparative experiments show that the proposed modeling scheme can improve the consistency of the dynamic performance of the model with that of the actual circuit. In addition, the proposed CF-FORLC model shows higher accuracy and flexibility with more adjustable parameters.
SPECTRUM OF A SELF-AFFINE MEASURE WITH FOUR-ELEMENT DIGIT SET
Authors: MEGALA M. , PRASAD SRIJANANI ANURAG
Published: February 2022

Let [Formula: see text] and [Formula: see text] be an expansive matrix. In this paper, we have proved that there exists [Formula: see text] such that the set [Formula: see text] is an orthonormal basis of [Formula: see text] for a matrix which has all even entries. Also, we have found a spectrum [Formula: see text] of [Formula: see text] for some specific [Formula: see text] and [Formula: see text].
A Unified Solution Method for Free Vibration of Arbitrarily Shaped Plates without or with Cracks
Authors: Song Yuyu , Xue Kai , Li Qiuhong
Published: February 2022

This paper presents a new approach for analyzing the free vibration of thin plates with arbitrary piecewise smooth curvilinear contour under various boundary conditions. It can also be applied to plates with cracks. This approach is based on the transformation of energy integral expressions and the domain decomposition technique. Furthermore, boundary conditions are modeled by using linear springs to restrain the plate edges. For obtaining the expressions of energy integral, the arbitrarily shaped domain of integration is divided into several trapezoid domains with curved sides by a set of parallel lines passing through the intersection points of contour curve segments. Then, Jacobi orthogonal polynomials are introduced as the admissible functions, so that the repeated integrals in the energy expressions are reduced to definite integrals analytically. At this point, the calculation method of the energy functional is determined by the equation forms of the curve segments of the plate contour. When the equations of the curve segments allow the integrands to have analytic primitive functions, the energy functional has an analytical solution. Otherwise, the Gauss–Legendre method is used to obtain the numerical solution. Accordingly, the arbitrarily shaped plate with cracks is decomposed into several arbitrarily shaped subdomains based on the cracks. Each subdomain is handled according to the above procedure. The continuity conditions at the interconnecting interfaces of the subdomains are realized by linear springs. The plate without or with crack is modeled by setting the spring stiffness to infinity or 0. The accuracy of the proposed method is verified by comparing the obtained results with the published results. Furthermore, the vibration characteristics of plates with various shapes, such as astroid-shaped plates and cracked elliptical plates, are investigated. These new results can serve as benchmarks for further studies on the vibration of plates.
Classification of noncommutative conics associated to symmetric regular superpotentials
Authors: Hu Haigang
Published: February 2022

Let [Formula: see text] be a [Formula: see text]-dimensional quantum polynomial algebra, and [Formula: see text] a central regular element. The quotient algebra [Formula: see text] is called a noncommutative conic. For a noncommutative conic [Formula: see text], there is a finite-dimensional algebra [Formula: see text] which determines the singularity of [Formula: see text]. In this paper, we mainly focus on a noncommutative conic such that its quadratic dual is commutative, which is equivalent to say, [Formula: see text] is determined by a symmetric regular superpotential. We classify these noncommutative conics up to isomorphism of the pairs [Formula: see text], and calculate the algebras [Formula: see text].
Character groups of dihedral and generalized quaternion groups
Authors: Stevenson Justin A. , Smith Jonathan D. H.
Published: February 2022

Finite abelian group duality appears in the discrete Fourier transform, or as the finite fragment of Pontryagin duality. The dual or character group of an abelian group encodes the products of its (linear) irreducible characters. Now, recent developments in combinatorics enable the construction of character groups for finite dihedral and generalized quaternion groups, encoding the products of all the irreducible characters (linear and nonlinear) in purely multiplicative fashion. In particular, just as in the abelian case, each dihedral group may serve as its own character group. Furthermore, certain Adams operations on the characters are shown to correspond to powers in the character group of a dihedral group.
A short note on polynomials f(X) = X + AX1+q2(q−1)/4 + BX1+3q2(q−1)/4 ∈ 𝔽q2[X], q even
Authors: Bartoli Daniele , Bonini Matteo
Published: February 2022

An alternative proof of the necessary conditions on [Formula: see text] for [Formula: see text] to be a permutation polynomial in [Formula: see text], [Formula: see text] even, is given. This proof involves standard arguments from algebraic geometry over finite fields and fast symbolic computations.
Modeling and Simulation of Reinforcement Mechanism in Preventing the Dysfunction of a Bellow-Like Artificial Muscle
Authors: Wu Ze , Lei Jingtao
Published: February 2022

Most artificial muscles currently in existence driven by negative pressure are in the form of origami. Their contractions are directly attained by extracting the air internal, and obtaining a differential pressure with the external (0.101[Formula: see text]MPa). During contraction, the artificial muscle simultaneously encounters radial and axial pressures provided by the atmosphere. If the muscle is isotropic, the radial pressure would make the artificial muscle unreliable, which would weaken the muscle’s contraction, including contraction force, ratio, and speed. This paper first introduces the contraction theory and dysfunction of the muscle. Then, an optimization method is proposed as local reinforcement, aiming at the muscle’s dysfunction that may occur during contraction. Then, by analyzing and comparing the optimization effects on the muscle contraction force and deformation with different reinforced regions, the endplates and crests are determined to be appropriate. Subsequently, the deformations of the reinforced regions when stressed are analyzed, and the adequate reinforcement dimensions are confirmed. Finally, the muscle’s model passes the simulation for ensuring its contraction without dysfunction, demonstrating the rationality of the reinforcement method proposed in this paper. Hereby, the goal of reinforcing the muscle’s radial stiffness is achieved, making the artificial muscle generate an optimal contraction performance.
The Supersonic Flutter Behavior of Sandwich Plates with an Magnetorheological Elastomer Core and Gnp-Reinforced Face Sheets
Authors: Arani Ali Ghorbanpour , Eskandari Masume , Haghparast Elham
Published: February 2022

This paper is provided to study the supersonic flutter behavior of sandwich plates with a magnetorheological (MR) core and polymeric face sheets reinforced with graphene nanoplatelets (GNPs). The mathematical modelings of the plate and the aerodynamic pressure of the fluid flow are performed utilizing the first-order shear deformation theory (FSDT) and the linear piston theory, respectively. The effective mechanical properties of the face sheets are estimated utilizing the rule of mixture along with the Halpin–Tsai model. Hamilton’s principle is employed to derive the governing equations and associated boundary conditions and these equations are solved using a semi-analytical approach for a Levy-type plate. The influences of different parameters on the aeroelastic stability of the plate are investigated such as the thickness of the MR core, magnetic field intensity, distribution pattern and mass fraction of the GNPs, boundary conditions, and geometrical parameters of the plate. This paper is the first theoretical attempt to study the effects of MR materials on the aeroelastic stability of Levy-type moderately thick sandwich plates and presents useful results that will be useful in the future of air vehicles.
Two-Dimensional Müntz–Legendre Wavelet Method for Fuzzy Hybrid Differential Equations
Authors: Shahryari N. , Allahviranloo T. , Abbasbandy S.
Published: February 2022

In this paper, the fuzzy approximate solutions for the fuzzy Hybrid differential equation emphasizing the type of generalized Hukuhara differentiability of the solutions are obtained by using the two-dimensional Müntz–Legendre wavelet method. To do this, the fuzzy Hybrid differential equation is transformed into a system of linear algebraic equations in a matrix form. Thus, by solving this system, the unknown coefficients are obtained. The convergence of the proposed method is established in detail. Numerical results reveal that the two-dimensional Müntz–Legendre wavelet is very effective and convenient for solving the fuzzy Hybrid differential equation.
Joint-Financing Framework for Water Services in the Thousand Island Lake Water Distribution Project in Eastern China
Authors: Mao Di , Shen Manhong , Xie Huiming
Published: February 2022

Valuing water is difficult and contentious owing to water’s physical, political, and economic characteristics. Combining household-level and county-level data at the county level could clarify the responsibilities of both the government and users. In the Thousand Island Lake Water Distribution Project (TILWDP), the upstream ecosystem services provider, Chunan County, is assumed to sustain a tremendous opportunity cost due to the extremely strict environmental protection requirements of the project. To estimate the opportunity cost of supplying fresh water that meets the standards of the National Primary Drinking Water Regulations, a synthetic control model is introduced, and county-level macroeconomic data are used. A funding gap was estimated in the current government-financed situation. Meanwhile, willingness to pay is calculated based on household-level data collected in the downstream area. The estimate indicates that the combination of ecological compensation payments from governments and downstream stakeholders’ willingness to pay for water services could completely cover the upstream service provider’s opportunity cost. Specifically, the related central and downstream governments would need to take on approximately 1/3 of the total cost, while the users from the downstream area would take on the rest. The proposed policies include adopting government–user joint-financing payment for ecosystem services (PES) schemes for regional ecological and environmental cooperation in China, implementing diversified payment vehicles, launching additional environmental education projects, etc.
Differentially Private Reinforcement Learning with Linear Function Approximation
Authors: Zhou Xingyu
Published: February 2022

Motivated by the wide adoption of reinforcement learning (RL) in real-world personalized services, where users' sensitive and private information needs to be protected, we study regret minimization in finite-horizon Markov decision processes (MDPs) under the constraints of differential privacy (DP). Compared to existing private RL algorithms that work only on tabular finite-state, finite-actions MDPs, we take the first step towards privacy-preserving learning in MDPs with large state and action spaces. Specifically, we consider MDPs with linear function approximation (in particular linear mixture MDPs) under the notion of joint differential privacy (JDP), where the RL agent is responsible for protecting users' sensitive data. We design two private RL algorithms that are based on value iteration and policy optimization, respectively, and show that they enjoy sub-linear regret performance while guaranteeing privacy protection. Moreover, the regret bounds are independent of the number of states, and scale at most logarithmically with the number of actions, making the algorithms suitable for privacy protection in nowadays large-scale personalized services. Our results are achieved via a general procedure for learning in linear mixture MDPs under changing regularizers, which not only generalizes previous results for non-private learning, but also serves as a building block for general private reinforcement learning.
End-to-end Characterization of Game Streaming Applications on Mobile Platforms
Authors: Bhuyan Sandeepa , Zhao Shulin , Ying Ziyu , Kandemir Mahmut T. , Das Chita R.
Published: February 2022

With the advent of 5G, supporting high-quality game streaming applications on edge devices has become a reality. This is evidenced by a recent surge in cloud gaming applications on mobile devices. In contrast to video streaming applications, interactive games require much more compute power for supporting improved rendering (such as 4K streaming) with the stipulated frames-per second (FPS) constraints. This in turn consumes more battery power in a power-constrained mobile device. Thus, the state-of-the-art gaming applications suffer from lower video quality (QoS) and/or energy efficiency. While there has been a plethora of recent works on optimizing game streaming applications, to our knowledge, there is no study that systematically investigates the  design pairs on the end-to-end game streaming pipeline across the cloud, network, and edge devices to understand the individual contributions of the different stages of the pipeline for improving the overall QoS and energy efficiency. In this context, this paper presents a comprehensive performance and power analysis of the entire game streaming pipeline consisting of the server/cloud side, network, and edge. Through extensive measurements with a high-end workstation mimicking the cloud end, an open-source platform (Moonlight-GameStreaming) emulating the edge device/mobile platform, and two network settings (WiFi and 5G) we conduct a detailed measurement-based study with seven representative games with different characteristics. We characterize the performance in terms of frame latency, QoS, bitrate, and energy consumption for different stages of the gaming pipeline. Our study shows that the rendering stage and the encoding stage at the cloud end are the bottlenecks to support 4K streaming. While 5G is certainly more suitable for supporting enhanced video quality with 4K streaming, it is more expensive in terms of power consumption compared to WiFi. Further, fluctuations in 5G network quality can lead to huge frame drops thus affecting QoS, which needs to be addressed by a coordinated design between the edge device and the server. Finally, the network interface and the decoder units in a mobile platform need more energy-efficient design to support high quality games at a lower cost. These observations should help in designing more cost-effective future cloud gaming platforms.
Memory Space Recycling
Authors: Ryoo Jihyun , Kandemir Mahmut Taylan , Karakoy Mustafa
Published: February 2022

Many program codes from different application domains process very large amounts of data, making their cache memory behavior critical for high performance. Most of the existing work targeting cache memory hierarchies focus on improving data access patterns, e.g., maximizing sequential accesses to program data structures via code and/or data layout restructuring strategies. Prior work has addressed this data locality optimization problem in the context of both single-core and multi-core systems. Another dimension of optimization, which can be as equally important/beneficial as improving data access pattern is to reduce the data volume (total number of addresses) accessed by the program code. Compared to data access pattern restructuring, this volume minimization problem has relatively taken much less attention. In this work, we focus on this volume minimization problem and address it in both single-core and multi-core execution scenarios. Specifically, we explore the idea of rewriting an application program code to reduce its "memory space footprint". The main idea behind this approach is to reuse/recycle, for a given data element, a memory location that has originally been assigned to another data element, provided that the lifetimes of these two data elements do not overlap with each other. A unique aspect is that it is "distance aware", i.e., in identifying the memory/cache locations to recycle it takes into account the physical distance between the location of the core and the memory/cache location to be recycled. We present a detailed experimental evaluation of our proposed memory space recycling strategy, using five different metrics: memory space consumption, network footprint, data access distance, cache miss rate, and execution time. The experimental results show that our proposed approach brings, respectively, 33.2%, 48.6%, 46.5%, 31.8%, and 27.9% average improvements in these metrics, in the case of single-threaded applications. With the multi-threaded versions of the same applications, the achieved improvements are 39.5%, 55.5%, 53.4%, 26.2%, and 22.2%, in the same order.
Robustness and Consistency in Linear Quadratic Control with Untrusted Predictions
Authors: Li Tongxin , Yang Ruixiao , Qu Guannan , Shi Guanya , Yu Chenkai , Wierman Adam , Low Steven
Published: February 2022

We study the problem of learning-augmented predictive linear quadratic control. Our goal is to design a controller that balances consistency, which measures the competitive ratio when predictions are accurate, and robustness, which bounds the competitive ratio when predictions are inaccurate.
Stationary Behavior of Constant Stepsize SGD Type Algorithms
Authors: Chen Zaiwei , Mou Shancong , Maguluri Siva Theja
Published: February 2022

Stochastic approximation (SA) and stochastic gradient descent (SGD) algorithms are work-horses for modern machine learning algorithms. Their constant stepsize variants are preferred in practice due to fast convergence behavior. However, constant stepsize SA algorithms do not converge to the optimal solution, but instead have a stationary distribution, which in general cannot be analytically characterized. In this work, we study the asymptotic behavior of the appropriately scaled stationary distribution, in the limit when the constant stepsize goes to zero. Specifically, we consider the following three settings: (1) SGD algorithm with a smooth and strongly convex objective, (2) linear SA algorithm involving a Hurwitz matrix, and (3) nonlinear SA algorithm involving a contractive operator. When the iterate is scaled by 1/α, where α is the constant stepsize, we show that the limiting scaled stationary distribution is a solution of an implicit equation. Under a uniqueness assumption (which can be removed in certain settings) on this equation, we further characterize the limiting distribution as a Gaussian distribution whose covariance matrix is the unique solution of a suitable Lyapunov equation. For SA algorithms beyond these cases, our numerical experiments suggest that unlike central limit theorem type results: (1) the scaling factor need not be 1/α, and (2) the limiting distribution need not be Gaussian. Based on the numerical study, we come up with a heuristic formula to determine the right scaling factor, and make insightful connection to the Euler-Maruyama discretization scheme for approximating stochastic differential equations.
Fusing Speed Index during Web Page Loading
Authors: Liu Wei , Yang Xinlei , Lin Hao , Li Zhenhua , Qian Feng
Published: February 2022

With conventional web page load metrics (e.g., Page Load Time) being blamed for deviating from actual user experiences, in recent years a more sensible and complex metric called Speed Index (SI) has been widely adopted to measure the user's quality of experience (QoE). In brief, SI indicates how quickly a page is filled up with above-the-fold visible elements (or crucial elements for short). To date, however, SI has been used as a metric for performance evaluation, rather than as an explicit heuristic to improve page loading. To demystify this, we examine the entire loading process of various pages and ascribe such incapability to three-fold fundamental uncertainties in terms of network, browser execution, and viewport size. In this paper, we design SipLoader, an SI-oriented page load scheduler through a novel cumulative reactive scheduling framework. It does not attempt to deal with uncertainties in advance or in one shot, but schedules page loading by "repairing" the anticipated (nearly) SI-optimal scheduling when uncertainties actually occur. This is achieved with a suite of efficient designs that fully exploit the cumulative nature of SI calculation. Evaluations show that SipLoader improves the median SI by 41%, and provides 1.43 times to 1.99 times more benefits than state-of-the-art solutions.
Regenerative Approaches for Chronic Wounds
Authors: Berthiaume François , Hsia Henry C.
Published: February 2022

Chronic skin wounds are commonly found in older individuals who have impaired circulation due to diabetes or are immobilized due to physical disability. Chronic wounds pose a severe burden to the health-care system and are likely to become increasingly prevalent in aging populations. Various treatment approaches exist to help the healing process, although the healed tissue does not generally recapitulate intact skin but rather forms a scar that has inferior mechanical properties and that lacks appendages such as hair or sweat glands. This article describes new experimental avenues for attempting to improve the regenerative response of skin using biophysical techniques as well as biochemical methods, in some cases by trying to harness the potential of stem cells, either endogenous to the host or provided exogenously, to regenerate the skin. These approaches primarily address the local wound environment and should likely be combined with other modalities to address regional and systemic disease, as well as social determinants of health.