bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinton Defends R&D in Partisan Speech
Authors: Lawler Andrew
Published: October 2021

In his first speech devoted entirely to science and technology, President Clinton blasted what he labeled “drastic”cuts Republicans are trying to make in the federal science budget.Some leading Democrats are asking for a tougher stand: a veto of spending bills that cut R&D.
Correction
Authors: Carleton Mark Alfred
Published: October 2021

A small but rather serious error occurred in my article, "Note on the fusarium wilt disease of bananas," appearing in SCIENCE of December 8, 1922. In lines 14 and 13 from the end, page 664, the word
inoculated
should be
un
inoculated.
Ultraviolet Light and Scurvy
Authors: Clark Janet H.
Published: October 2021

Three experiments with different scorbutic diets showed that ultraviolet radiation is entirely ineffectual in preventing or postponing scurvy. With diets in which other factors, besides the scorbutic vitamin, were lacking, ultraviolet light hastened loss of weight and death from scurvy somewhat and prevented recovery after orange and cabbage were added to the diet. This, however, was not true when a diet lacking only in the antiscorbutic vitamin was used.
Erratum: The Internal Constitution of the Stars
Authors: Plaskett H. H.
Published: October 2021

In the review of Eddington's book on "The Internal Constitution of the Stars," by Dr. H. H. Plaskett, printed in the issue of SCIENCE for July 22, several lines were misplaced at the bottom of the right-hand column on page 82. The passage should read:

Of the several quantitative predictions furnished by Eddington's model, none is more striking or more general than this relation that the luminosity of a star, apart from a small factor depending upon the surface temperature, is a single-valued function of its mass. The relation contains but one disposable constant (the proportionality constant of Kramers's absorption law), and this is fixed from the mass, luminosity and effective temperature of a single star (Capella). It is then found that all thirty-seven stars of known mass and luminosity, both giants and dwarfs, lie on Eddington's mass-luminosity curve with the average residual of the order of half a magnitude.
Ivory poaching and the rapid evolution of tusklessness in African elephants
Authors: Campbell-Staton Shane C. , Arnold Brian J. , Gonçalves Dominique , Granli Petter , Poole Joyce , Long Ryan A. , Pringle Robert M.
Published: October 2021

Lose the tusks

Harvest and poaching of wildlife have increased as the human population and our technology have grown. These pressures now occur on such a scale that they can be considered selective drivers. Campbell-Staton
et al
. show that this phenomenon has occurred in African elephants, which are poached for their ivory, during the 20-year Mozambican civil war (see the Perspective by Darimont and Pelletier). In response to heavy poaching by armed forces, African elephant populations in Gorongosa National Park declined by 90%. As the population recovered after the war, a relatively large proportion of females were born tuskless. Further exploration revealed this trait to be sex linked and related to specific genes that generated a tuskless phenotype more likely to survive in the face of poaching. —SNV
Share vaccine know-how
Authors: Krishtel Priti , Hassan Fatima
Published: October 2021

Leaders of the world’s major economies, representing 80% of the world’s gross domestic product, will meet at the end of this month at the G20 meeting in Rome to address issues of global importance, including how to increase the worldwide supply of COVID-19 vaccines. How the world addresses the current state of vaccine inequity will affect how we meet future global disease challenges.
Ancient DNA reveals long-sought homeland of modern horses
Authors: Gibbons Ann
Published: October 2021

Bronze Age herders began riding the ancestor of modern horses in the grassy western Eurasian steppe
Trends in inpatient admissions and emergency department visits for heart failure in adults with versus without diabetes in the USA, 2006–2017
Authors: Harding Jessica L , Benoit Stephen R , Hora Israel , Sridharan Lakshmi , Ali Mohammed K , Jagannathan Ram , Patzer Rachel E , Narayan K M Venkat
Published: October 2021

Introduction

Heart failure (HF) is a major contributor to cardiovascular morbidity and mortality in people with diabetes. In this study, we estimated trends in the incidence of HF inpatient admissions and emergency department (ED) visits by diabetes status.

Research design and methods

Population-based age-standardized HF rates in adults with and without diabetes were estimated from the 2006–2017 National Inpatient Sample, Nationwide ED Sample and year-matched National Health Interview Survey, and stratified by age and sex. Trends were assessed using Joinpoint.

Results

HF inpatient admissions did not change in adults with diabetes between 2006 and 2013 (from 53.9 to 50.4 per 1000 persons; annual percent change (APC): −0.3 (95% CI −2.5 to 1.9) but increased from 50.4 to 62.3 between 2013 and 2017 (APC: 4.8 (95% CI 0.3 to 9.6)). In adults without diabetes, inpatient admissions initially declined (from 14.8 in 2006 to 12.9 in 2014; APC −2.3 (95% CI −3.2 to –1.2)) and then plateaued. Patterns were similar in men and women, but relative increases were greatest in young adults with diabetes. HF-related ED visits increased overall, in men and women, and in all age groups, but increases were greater in adults with (vs without) diabetes.

Conclusions

Causes of increased HF rates in hospital settings are unknown, and more detailed data are needed to investigate the aetiology and determine prevention strategies, particularly among adults with diabetes and especially young adults with diabetes.
Establishing the influence of case complexity on the order of cataract lists: a cross-sectional survey
Authors: McLean Keri , Ferrara Mariantonia , Kaye Rebecca , Romano Vito , Kaye Stephen
Published: October 2021

Objective

Order of the theatre list and complexity of the cases are important considerations which are known to influence surgical outcomes. This survey aimed to establish their influence on cataract surgery.

Methods and Analysis

Cataract surgeons ordered five cataract cases according to their surgical preference, first using case notes and second using composite ORs (CORs) for posterior capsule rupture. Descriptive and non-parametric statistics were used to analyse the data.

Results

Between 11 June and 14 July 2020, 192 cataract surgeons from 14 countries completed the online survey. Majority of the surgeons (142 vs 50) preferred to choose the order of their list (p<0.01) and to review the case notes prior to the day of surgery (89 vs 53; p=0.04). 39.86% preferred to start with the less risky case and 32.43% reserved the last position on the list for the riskiest case. There was a significant trend to order the list in an ascending level of risk, independent of whether case notes or CORs were used. Additionally, 44.79% of the respondents indicated they would be happy to have their list order planned by an automated program based on their preferred risk score.

Conclusion

This survey demonstrates that cataract surgeons prefer to choose the order of their theatre list and that the order is dependent on the complexity of cases. There is support among surgeons for automated list ordering based on an objective score for risk stratification, such as a COR.
Management and outcomes of patients with left atrial appendage thrombus prior to percutaneous closure
Authors: Marroquin Luis , Tirado-Conte Gabriela , Pracoń Radosław , Streb Witold , Gutierrez Hipolito , Boccuzzi Giacomo , Arzamendi-Aizpurua Dabit , Cruz-González Ignacio , Ruiz-Nodar Juan Miguel , Kim Jung-Sun , Freixa Xavier , Lopez-Minguez Jose Ramon , De Backer Ole , Ruiz-Salmeron Rafael , Dominguez Antonio , McInerney Angela , Peral Vicente , Estevez-Loureiro Rodrigo , Fernandez-Nofrerias Eduard , Freitas-Ferraz Afonso B , Saia Francesco , Huczek Zenon , Gheorghe Livia , Salinas Pablo , Demkow Marcin , Delgado-Arana Jose R , Fernandez Peregrina Estefania , Kalarus Zbibniew , Elvira Laffond Ana , Jang Yangsoo , Fernandez Camacho Jose Carlos , Lee Oh-Hyun , Hernández-Garcia Jose M , Mas-Llado Caterina , Caneiro Queija Berenice , Amat-Santos Ignacio J , Dabrowski Maciej , Rodés-Cabau Josep , Nombela Franco Luis
Published: October 2021

Objective

Left atrial appendage (LAA) thrombus has heretofore been considered a contraindication to percutaneous LAA closure (LAAC). Data regarding its management are very limited. The aim of this study was to analyse the medical and invasive treatment of patients referred for LAAC in the presence of LAA thrombus.

Methods

This multicentre observational registry included 126 consecutive patients referred for LAAC with LAA thrombus on preprocedural imaging. Treatment strategies included intensification of antithrombotic therapy (IAT) or direct LAAC. The primary and secondary endpoints were a composite of bleeding, stroke and death at 18 months, and procedural success, respectively.

Results

IAT was the preferred strategy in 57.9% of patients, with total thrombus resolution observed in 60.3% and 75.3% after initial and subsequent IAT, respectively. Bleeding complications and stroke during IAT occurred in 9.6% and 2.9%, respectively, compared with 3.8% bleeding and no embolic events in the direct LAAC group before the procedure. Procedural success was 90.5% (96.2% vs 86.3% in direct LAAC and IAT group, respectively, p=0.072), without cases of in-hospital thromboembolic complications. The primary endpoint occurred in 29.3% and device-related thrombosis was found in 12.8%, without significant difference according to treatment strategy. Bleeding complications at 18 months occurred in 22.5% vs 10.5% in the IAT and direct LAAC group, respectively (p=0.102).

Conclusion

In the presence of LAA thrombus, IAT was the initial management strategy in half of our cohort, with initial thrombus resolution in 60% of these, but with a relatively high bleeding rate (~10%). Direct LAAC was feasible, with high procedural success and absence of periprocedural embolic complications. However, a high rate of device-related thrombosis was detected during follow-up.
Changing Attitudes to the Diagnosis of Asbestos Disease
Authors: Mackenzie F. A. F. , Harries P. G.
Published: October 2021

Large numbers of dockyard workers in Plymouth, intermittently exposed to asbestos, have been found to have pleural abnormalities. The more extensive pleural reactions, often accompanied by effusion, are occurring in younger men after about 15 years’ exposure to asbestos. The significance of these changes in relation to the development of malignant disease is not yet known. A modified radiographic technique and the radiological appearances are described.
Hyperbaric Oxygen Therapy in the Treatment of Gas Gangrene
Authors: Beavis John P. , Watt James
Published: October 2021

Gas gangrene will continue to complicate contaminated war injuries. Local and systemic effects of exotoxins are described and an aggressive regimen of therapy is proposed. The beneficial results of such treatment are reported and the respective merits of hyperbaric oxygen, antibiotics, debridement and cortisone are debated. The histological appearances of muscle biopsies obtained at initial debridement are discussed.
The Significance of Prostatitis in Urinary Tract Infection in the Male
Authors: Blacklock Norman J.
Published: October 2021

A review of all cases of urinary tract infection occurring in a naval population group has been carried out over a four year period. There were 281 cases of cysto-prostatitis; a previous venereal urethritis did not occur significantly in these cases and the incidence appeared to be greater in married as opposed to single personnel. The importance of direct examination of prostatic fluid in the assessment of these cases is established. The response to initial treatment of the condition may be a guide to long term prognosis.

Cases of epididymitis and pyelonephritis were also considered during the same four year period. Evidence of a primary infective focus in the prostate gland in these conditions is established and the possible pathway and mechanism of infection from this focus is discussed. Attention is drawn, again, to the importance of examination of the prostatic fluid in these cases. Effective treatment of these conditions must ensure eradication of the infective focus within the prostate gland as well, in order to minimise the chance of relapse.
Emergency Pyelography in Renal Colic
Authors: Mackenzie F. A. F. , Kirkpatrick J. R. , Telfer R. C.
Published: October 2021

A comparative study between the results obtained from conventional pyelography and immediate pyelography during renal colic was undertaken during a period of 18 months, at RNFf Malta.

Forty-seven patients were examined and there were only four cases with no signs of renal calculus. This is a great improvement on the accuracy obtained by the delayed method. The patients with calculi were examined radiologically until the site of obstruction was determined. In patients who showed the nephrographic effect, the earliest results were obtained in one hour; the majority in two to three hours, and, in the most prolonged examination, a 10 hour follow-up was necessary. The site of the obstruction is important from the point of view of the surgical approach. The interesting feature when obstruction was demonstrated was that approximately 40 per cent of calculi were non-opaque.

Estimates were also made of function and the degree of hydronephrosis. Renal enlargement was measured and the return to normal in these indirect signs was followed up in the majority of cases.

In one case pyelography repeated in five days, after the passage of a small calculus, showed a return to normal. In several other cases where pyelography was repeated within two to three weeks, a normal appearance was also seen. It is in this group of patients that conventional delayed pyelography would miss the signs of pathology.
Problem Drinking
Authors: Marjot David H.
Published: October 2021

Problem drinking is relatively common in the Royal Navy, but can be halted in many cases if recognised in time. The drinking patterns and social consequences of problem drinking are discussed and symptoms of alcohol dependence are described. Cases fall into early, established and late groups and diagnostic features are discussed.
The Precision Retained Full Denture
Authors: Walker Richard T
Published: October 2021

The advantage of retaining one or two teeth in the otherwise edentulous arch is discussed in connection with the procedure of elective devitalisation and construction of a precision retained full denture. One such case is reported.
Warm Water Immersion Injuries of the Feet – A Review
Authors: Catterall M. D.
Published: October 2021

Warm water immersion injuries of the feet are of considerable relevance to military operations in tropical and sub-tropical regions.

An outline of experience gained during the 1939-45 and Vietnam wars is given.

Recently, two distinct warm water immersion injuries have been delineated viz. Warm Water Immersion Foot (WWIF) and Tropical Immersion Foot (TIF), the latter resulting from longer periods of immersion.

The current state of knowledge with respect to pathogenesis, clinical features, histopathology, management and prophylaxis, of these two syndromes, is presented.

A requirement exists for further study, with emphasis on the pathogenesis and prophylaxis of Tropical Immersion Foot.
Repair of Prostato-Rectal Fistula
Authors: Rowland F. H.
Published: October 2021

A case is described of a para sacral approach to the rectum for closure of a prostato-rectal fistula. Full anal control resulted from this unusual approach.

This case is of interest in that it records the utilisation for the first time in Gibraltar of an unusual surgical approach to the rectum.
The Prevalence of Abnormal Haemoglobins among a Group of Ghanaian Naval Ratings
Authors: Atuah O. K.
Published: October 2021

A small group of Ghanaian naval ratings in the UK for a short period were examined to determine their haemoglobin status which could under active Service conditions significantly affect their employability. The distribution in this small series was found to be: Hb AS 20%, Hb AC 3%, Hb AA 77%. Parallel examination of haemoglobin by electrophoresis and by "sickledex’ test, which is cheaper and less technically demanding, confirmed the efficiency of the latter test.
The Disto-Palatal Groove in Maxillary Incisors; A Predisposing Factor in Periodontal Disease
Authors: Walker Richard T.
Published: October 2021

Disto-palatal grooving of the maxillary lateral incisor is discussed in relation to localised periodontal disease, and a clinical case is demonstrated. The clinical and radiographic appearance of the malformation is described.
A Case of Idiopathic Apical Root Resorption of the Maxillary Molar Teeth
Authors: Weston M. W.
Published: October 2021

Idiopathic apical root resorption of all maxillary molars is a rare occurrence and this paper reports a case seen recently in RNAS Yeovilton.
The Use and Abuse of Histamine H2-Receptor Antagonists
Authors: Milton-Thompson G. J.
Published: October 2021

The development of a new group of drugs blocking the histamine H2-receptors involved in the stimulation of gastric acid secretion is described. The indications for their use in peptic ulcer disease, reflux oesophagitis, acute gastrointestinal bleeding and the Zollinger-Ellison syndrome are considered but the need for precise diagnosis before treatment is emphasised. It is likely that these drugs will greatly alter the medical management of these conditions.
The Use of Computer Assisted Data Processing and Display Methods in Brain Scintigraphy
Authors: Houston A. S.
Published: October 2021

Much has been published recently on the use of data processing and display methods in radioisotope scintigraphy. The main theme has been a move towards proper evaluation of these techniques. Using a procedure which combines clinical significance with physical relevance, the author has recently compared many different methods used for static brain studies. This paper describes those which performed best.
Posthitis Xerotica Obliterans
Authors: Buchanan J. D. , Catterall M. D. , Briggs P. C.
Published: October 2021

Posthitis Xerotica Obliterans is a chronic sclerosing and atrophic disease of the prepuce which commonly results in phimosis. A 16 month prospective study has demonstrated an overall incidence of 16 per cent amongst 75 routine circumcision specimens with four cases affecting prepubertal children.
The Influence of Glucose and Crude Fibre (Wheat Bran) on the Rate of Intestinal 47Ca Absorption The Influence of Glucose and Wheat Bran on Calcium Absorption
Authors: Macleod M. A. , Blacklock N. J.
Published: October 2021

With evidence of induction of increased urinary excretion of calcium by the ingestion of glucose and sucrose there is the theoretical possibility in these circumstances of at least a transient negative calcium balance. In this study the ingestion of glucose or glucose equivalent was found to stimulate 47Ca absorption from the intestine both in normal subjects and in idiopathic calcium stone formers. This induced increase in the rate of 47Ca absorption by glucose can be negated by the addition of crude fibre in the form of wheat bran.
UVL Induced Changes in Calcium Absorption and Excretion and in Serum Vit D3 Levels measured in Black-skinned and Caucasian Males
Authors: Macleod M. A. , Blacklock N. J.
Published: October 2021

With the evident increase in osteolytic disease, especially in black-skinned urban communities, it has become necessary to attempt to define and measure dietetic and environmental factors contributing to this increase. This paper describes and measures calcium absorption and excretion and serum hydroxy-cholecalciferol (Vit D3) levels in both black-skinned and caucasian controls exposed to similar doses of ultra-violet light. It is concluded that there is a significant difference in response to UVL stimulus between the two groups to the detriment of the blackskinned population.
Quinolinic acid, a kynurenine/tryptophan pathway metabolite, associates with impaired cognitive test performance in systemic lupus erythematosus
Authors: Anderson Erik W , Fishbein Joanna , Hong Joseph , Roeser Julien , Furie Richard A , Aranow Cynthia , Volpe Bruce T , Diamond Betty , Mackay Meggan
Published: October 2021

Objectives

Interferon-alpha, an important contributor to SLE pathogenesis, induces the enzyme indoleamine 2,3-dioxygenase in the kynurenine/tryptophan (KYN/TRP) pathway. This leads to a potentially neurotoxic imbalance in the KYN/TRP pathway metabolites, quinolinic acid (QA), an N-methyl D-aspartate glutamatergic receptor (NMDAR) agonist, and kynurenic acid (KA), an NMDAR antagonist. We determined whether QA/KA ratios associate with cognitive dysfunction (CD) and depression in SLE.

Methods

This cross-sectional study included 74 subjects with SLE and 74 healthy control (HC) subjects; all without history of neuropsychiatric disorders. Serum metabolite levels (KYN, TRP, QA, KA) were measured concurrently with assessments of cognition (Automated Neuropsychological Assessment Metrics (ANAM), 2×2 array), mood and pain, and compared between SLE and HC. Multivariable modelling in SLE was used to evaluate associations of metabolites with cognitive performance and depression.

Results

Serum KYN/TRP and QA/KA ratios were elevated in SLE versus HC (p<0.0001). SLE performed worse than HC on four of five ANAM tests (all p≤0.02) and the 2×2 array (p<0.01), and had higher depression scores (p<0.01). In SLE, elevated QA/KA ratios correlated with poor performance on Match to Sample (MTS), a working memory and visuospatial processing task (p<0.05). Subjects with SLE with elevated QA/KA ratios also had slightly higher odds of depression, but this did not reach significance (p=0.09). Multivariable modelling in SLE confirmed an association between QA/KA ratios and poor MTS performance when considering potentially confounding factors (p<0.05).

Conclusions

Elevated serum KYN/TRP and QA/KA ratios confirm KYN/TRP pathway activation in SLE. The novel association between increased QA/KA ratios and poor cognitive performance supports further study of this pathway as a potential biomarker or therapeutic target for SLE-mediated CD.
SHIFTED LEGENDRE FRACTIONAL PSEUDOSPECTRAL DIFFERENTIATION MATRICES FOR SOLVING FRACTIONAL DIFFERENTIAL PROBLEMS
Authors: ABDELHAKEM MOHAMED , ABDELHAMIED DINA , ALSHEHRI MARYAM G. , EL-KADY MAMDOUH
Published: October 2021

A new differentiation technique, fractional pseudospectral shifted Legendre differentiation matrices (FSL D-matrices), was introduced. It depends on shifted Legendre polynomials (SLPs) as a base function. We take into consideration its extreme points and inner product. The technique was used to solve fractional ordinary differential equations (FODEs). Moreover, it extended to approximate fractional integro-differential equations (FIDEs) and fractional optimal control problems (FOCPs). The novel FSL D-matrices transformed these fractional differential problems (FDPs) into an algebraic system of equations. Also, an error and a convergence analysis for that technique were investigated. Finally, the correctness and efficiency of this technique were examined with test functions and several examples. All the results were compared with the results of other methods to ensure the investigated error analysis.
User Experience Evaluation of Cross‐Channel Consumption: Based on Grounded Theory and Neural Network
Authors: Yang Hua , Wei Huiying , He Xiang , Yan Yue , Liu Xiaoju
Published: October 2021

With the rapid development of e‐commerce technology, cross‐channel consumption has become the mainstream mode of contemporary consumers. However, there are several problems of cross‐channel consumption such as inconsistency of online and offline channel information and service, disfluency of channel switching which have brought adverse effects on user experience. The question arises here as to what factors influence user experience and how to build a scientific and effective evaluation index system. Different from previous studies based on sellers, this paper used grounded theory to analyze and summarize the evaluation index system of user experience under cross‐channel consumption from the perspective of consumers. We summarized and refined four first level indexes which are “online platform attribute, offline entity attribute, channel switching attribute, and individual demand” and 13 second level indexes which are “platform operation, platform information, platform service, platform promotion, product quality, service quality, environment quality, channel consistency, channel switching cost, channel switching fluency, psychological expectation, personal interests and individual needs.” Then, we used BP neural network to build the evaluation model and trained and simulated the performance of the sample. The results show that the evaluation model has a good generalization ability and can effectively evaluate user experience under cross‐channel consumption. Finally, implications and limitations are also discussed. This study helps to enrich the theoretical research on user experience and consumer behavior. It also provides targeted basis for in‐depth analysis of cross‐channel consumption behavior, establishment of user experience evaluation index system, and improving user experience and multichannel management of physical stores.
The Mobile Water Quality Monitoring System Based on Low‐Power Wide Area Network and Unmanned Surface Vehicle
Authors: Chen Wei , Hao Xiao , Yan Kui , Lu JianRong , Liu Jin , He ChenYu , Zhou Feng , Xu Xin
Published: October 2021

The increasingly serious water pollution problem makes efficient and information‐based water quality monitoring equipment particularly important. To cover the shortcomings of existing water quality monitoring methods, in this paper, a mobile water quality monitoring system was designed based on LoRa communication and USV. In this system, the USV carrying water quality sensors was used as a platform. Firstly, the LoRa network is used to monitor water quality over a large area. Secondly, the unmanned surface vessel controls the position error within ±20 m and the velocity error within ±1 m/s based on the Kalman filter algorithm. Thirdly, the genetic algorithm based on improved crossover operators is used to determine the optimal operational path, which effectively improves the iterative efficiency of the classical genetic algorithm and avoids falling into local convergence. In the actual water surface test, its packet loss probability within a working range of 1.5 km was below 10%, and the USV could accurately navigate according to the preset optimal path. The test results proved that the system has a relatively large working range and high efficiency. This study is of high significance in water pollution prevention and ecological protection.
Blow-Up Results for a Class of Quasilinear Parabolic Equation with Power Nonlinearity and Nonlocal Source
Authors: Zhang Xiaorong , Cui Zhoujin
Published: October 2021

This paper deals with a class of quasilinear parabolic equation with power nonlinearity and nonlocal source under homogeneous Dirichlet boundary condition in a smooth bounded domain; we obtain the blow-up condition and blow-up results under the condition of nonpositive initial energy.
Design of Pulse Wave Feature Vigilance Detection System Based on Computer Software Technology
Authors: Zeng Yidong , Ji Jun , Wang Jinghua , Gao Jiasuo , Hu Jie , Yuan Youfa
Published: October 2021

In this paper, the pulse wave feature alertness detection system based on computer software technology is researched. First, the computer software technology designs the alertness detection system and then conducts the system alertness test experiment using a system that can not affect the subjects’ alertness, a portable multichannel physiological signal acquisition system that measures the subjects’ ECG signal, skin resistance, blood oxygen saturation, and other physiological signals in the case of a degree task experiment. The multichannel physiological signal acquisition system collects the signals during the vigilance task experiment. At the same time, before, during, and after the experiment, subjects are required to fill in the Stanford Sleepiness Scale (SSS) and evaluate the level of individual alertness through subjective self-evaluation. The relevant experimental data show that, 10 minutes before the experiment, the pulse amplitude increased rapidly, then slowly decreased at the beginning, reached a peak in about 25 minutes, and then began to rise.
On the Boundedness of the Numerical Solutions’ Mean Value in a Stochastic Lotka–Volterra Model and the Turnpike Property
Authors: Romero-Meléndez Cutberto , Castillo-Fernández David , González-Santos Leopoldo
Published: October 2021

In this paper, we study some properties of the solutions of a stochastic Lotka–Volterra predator‐prey model, namely, the boundedness in the mean of numerical solutions, the strong convergence for this kind of solutions, and the turnpike property of solutions of an optimal control problem in a population modelled by a Lotka–Volterra system with stochastic environmental fluctuations. Even though there are numerous results in the deterministic case, there are few results for the behavior of numerical solutions in a population dynamic with random fluctuations. First, we show, using the Euler–Maruyama scheme, that the boundedness of numerical solutions and the convergence of the scheme are preserved in the stochastic case. Second, we analyze a property of the long‐term behavior of a Lotka–Volterra system with stochastic environmental fluctuations known as turnpike property. In optimal control theory, the optimal solutions dwell mostly in the neighborhood of a balanced equilibrium path, corresponding to the optimal steady‐state solution. Our study shows, by means of the Stochastic Maximum Principle, that this turnpike property is preserved, when the noise in the system is small. Numerical simulations are implemented to support our results.
Novel Nano-Based Drug Delivery Systems Targeting Hepatic Stellate Cells in the Fibrotic Liver
Authors: Ezhilararasan Devaraj , Lakshmi Thangavelu , Raut Biond
Published: October 2021

Hepatic stellate cells (HSCs) exist in the liver’s perisinusoidal space, are phenotypically activated, and acquire myofibroblast-like phenotype. This phenotypic transformation is accountable for the accumulation and production of various extracellular matrix (ECM) proteins, involving different fibril-forming collagens in the perisinusoidal space, producing altered hepatic function and portal hypertension and increased vascular resistance, fibrosis, cirrhosis, and hepatocellular carcinoma. The activated HSCs/myofibroblasts are principal collagen-producing cells in the damaged liver. Therefore, fibrosis treatments are often targeting HSCs. HSCs store most of the total body’s retinol in their cytoplasm, and hence, antifibrotic nanomedicines are often targeted with vitamin A decoration. Vitamin A-decorated nanomedicines with siRNAs for transforming growth factor-beta, collagen, and connective tissue growth factors target to inhibit fibrogenesis and the ECM-associated gene expressions, leading to fibrosis regression. Similarly, a variety of miRNAs play pro- and antifibrotic function. In the fibrotic liver, the profibrotic miRNAs are targeted with their respective antagomir and the antifibrotic miRNAs are targeted with their respective agomirs along with HSC-specific nanodecoration. These miRNA treatments reduce fibrogenesis by downregulation of ECM-related gene expressions. However, liver fibrosis is caused by the upregulation of a different type of profibrotic signaling pathways associated with ECM accumulation in the fibrotic liver. Therefore, specific gene silencing by siRNAs or targeting particularly miRNA may also not effectively reduce fibrosis to a greater extent. However, nanodecoration of a drug is useful to deliver drugs into activated HSCs in the injured liver. Therefore, the aim of this review is to focus on targeted drug delivery towards activated HSCs in the persistently damaged liver.
Existence of Multiple Positive Solutions for Brezis–Nirenberg-Type Problems Involving Singular Nonlinearities
Authors: El Mokhtar Mohammed El Mokhtar Ould , Matallah Atika
Published: October 2021

\This article is devoted to the existence and multiplicity to the following Brezis–Nirenberg-type problems involving singular nonlinearities:−Δu=up−1u+λu−1−β/xαuin Ωu=0on ∂Ω, whereΩis a smooth bounded domain inℝNN≥3,0∈Ω,λ>0,p=2∗−1with2∗≔2N/N−2is the critical Sobolev exponent,0≤α<Np+β/p+1, and0<β<1. By using the Nehari manifold and maximum principle theorem, the existence of at least two distinct positive solutions is obtained.
Dynamics Analysis of a Stochastic Plant Disease Model with Continuous Cultural Control Strategy
Authors: Zhang Haisu , Zhang Tongqian
Published: October 2021

In this paper, a new stochastic plant disease model with continuous control strategy is proposed and analyzed. The dynamics of the system are explored under white noise disturbance. We prove that if R1 > 1, then the disease is persistent; moreover, if R2 > 1, then the solutions of the system have a stationary distribution. For the special case, we prove that if R1 < 1, then the disease will eventually disappear. Finally, some numerical simulations were implemented to illustrate the theoretical results.
Ultrasound-Accelerated, Concise, and Highly Efficient Synthesis of 2-Oxazoline Derivatives Using Heterogenous Calcium Ferrite Nanoparticles and Their DFT Studies
Authors: Bendi Anjaneyulu , Atri Shalu , Rao G. B. Dharma , Raza Mohd Jamshaiya , Sharma Nutan
Published: October 2021

A rapid and operationally simple approach for synthesising biologically relevant 2-oxazoline derivatives has been developed through highly efficient ultrasound-promoted coupling reactions of thioamides and amino alcohols using calcium ferrite nanoparticles as heterogeneous catalysts. The major advantage of using ultrasound irradiation lies in the drastic reduction of reaction time as compared with conventional stirring. Furthermore, quantum chemical investigations for the synthesised 2-oxazoline derivatives have been carried out at the DFT/B3LYP/6-311 + G (d, p) level of theory to predict the optimized geometry. The molecular properties such as bond lengths, bond orders, Milliken charges, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential map, and thermodynamic parameters of all the compounds have also been reported at the same level of theory.
In situ Effect of CO2 Laser (9.3 μm) Irradiation Combined with AmF/NaF/SnCl2 Solution in Prevention and Control of Erosive Tooth Wear in Human Enamel
Authors: Tavares Juliane de Paula , da Silva Camila Vieira , Engel Yael , de Freitas Patricia Moreira , Rechmann Peter
Published: October 2021

Objectives: This single-blind, controlled crossover in situ study aimed to evaluate the effect of CO2 laser (9.3 µm) irradiation combined with AmF/NaF/SnCl2 solution on prevention and control of erosive tooth wear (ETW) in human enamel. Materials and Methods: Two trial conditions were analyzed, condition 1 as ETW prevention (sound tooth surface) and condition 2 as ETW control (in vitro initial erosive lesion). The experiment was conducted in 2 phases, one with and one without exposure to AmF/NaF/SnCl2 solution. Hundred and ninety-two samples of human enamel (3 × 3 × 1 mm) were randomly divided into 4 experimental groups for each condition: C, without treatment (negative control); F, AmF/NaF/SnCl2 solution (positive control); L, CO2 laser irradiation; and L + F, CO2 laser + AmF/NaF/SnCl2 solution. Twelve volunteers used a removable device, each containing 8 samples per phase. Ex vivo erosive challenges (4 × 5 min/day) and rinsing protocol (1 × 30 s/day) were performed. The surface loss was determined using optical profilometer (n = 12 per group), and the surface morphology was observed with scanning electron microscopy (n = 3). Results: In condition 1, data were analyzed by one-way ANOVA and condition 2 by two-way repeated-measures ANOVA, both with Tukey post hoc tests (α = 5%). In condition 1, groups L (4.59 ± 2.95 µm) and L + F (1.58 ± 1.24 µm) showed significantly less surface loss in preventing ETW than groups C and F. In condition 2, in controlling the progression of ETW, L + F was the only group with no significant surface loss between initial erosive lesion (3.65 ± 0.16 µm) and after erosive challenge (4.99 ± 1.17 µm). Conclusions: CO2 9.3-µm laser application prevented and controlled ETW progression in human enamel, with greater efficiency when combined with AmF/NaF/SnCl2 solution application.
A new species of ‘Bird’s Nest’Anthurium sect. Pachyneurium (Araceae) from Brazil
Authors: CAMELO MEL DE CASTRO , CROAT THOMAS B. , COELHO MARCUS A.N. , AYLWARD STEVE
Published: October 2021

While studying Anthurium sect. Pachyneurium from Brazil, a new species Anthurium mayoanum was discovered in Floresta de Igapó from Pará State. The species is described and illustrated. The species presents a set of characteristics that are for sect. Pachyneurium, particularly the atypical base of leaf blade and the color of spadix. We have compared this new species with other related taxa of section Pachyneurium and have provided commentary on geographical distribution, conservation status, ecology and phenology.
Preparation and Mechanical Properties of Polyurethane Material for Railway Ballast
Authors: Guochong Lou , Haiyan Yang
Published: October 2021

ABSTRACTThe elastic solidification of track bed is a new track structure improvement technology between the traditional gravel track bed and the ballast less track monolithic track bed. It can effectively solve the main technical problems of heavy haul railway transportation,
such as large impact force of wheel rail, serious deformation of track bed and frequent maintenance etc. In this paper, combined with the characteristics of polyurethane properties affected by its chemical composition, a solidified ballast polyurethane material suitable for heavy haul railway
was developed by adding diluents and other materials. Physical property test and mechanical triaxial test were carried out to assess the influence of diluent content on the hardening effect of ballast; the physical process and mechanical properties of different proportion materials were analyzed.
The experimental results show that adding appropriate amount of diluent into polyurethane material can effectively improve the integrity of ballast bed, increase the strength, reduce the deformation, and prolong the service life of ballast track bed.
Persistence of Escherichia coli in the microbiomes of red Romaine lettuce (Lactuca sativa cv. ‘Outredgeous’) and mizuna mustard (Brassica rapa var. japonica) - does seed sanitization matter?
Authors: Dixit Anirudha R. , Khodadad Christina L. M. , Hummerick Mary E. , Spern Cory J. , Spencer LaShelle E. , Fischer Jason A. , Curry Aaron B. , Gooden Jennifer L. , Maldonado Vazquez Gretchen J. , Wheeler Raymond M. , Massa Gioia D. , Romeyn Matthew W.
Published: October 2021

Background

Seed sanitization via chemical processes removes/reduces microbes from the external surfaces of the seed and thereby could have an impact on the plants’ health or productivity. To determine the impact of seed sanitization on the plants’ microbiome and pathogen persistence, sanitized and unsanitized seeds from two leafy green crops, red Romaine lettuce (Lactuca sativa cv. ‘Outredgeous’) and mizuna mustard (Brassica rapa var. japonica) were exposed to Escherichia coli and grown in controlled environment growth chambers simulating environmental conditions aboard the International Space Station. Plants were harvested at four intervals from 7 days post-germination to maturity. The bacterial communities of leaf and root were investigated using the 16S rRNA sequencing while quantitative polymerase chain reaction (qPCR) and heterotrophic plate counts were used to reveal the persistence of E. coli.

Result

E. coli was detectable for longer periods of time in plants from sanitized versus unsanitized seeds and was identified in root tissue more frequently than in leaf tissue. 16S rRNA sequencing showed dynamic changes in the abundance of members of the phylum Proteobacteria, Firmicutes, and Bacteroidetes in leaf and root samples of both leafy crops. We observed minimal changes in the microbial diversity of lettuce or mizuna leaf tissue with time or between sanitized and unsanitized seeds. Beta-diversity showed that time had more of an influence on all samples versus the E. coli treatment.

Conclusion

Our results indicated that the seed surface sanitization, a current requirement for sending seeds to space, could influence the microbiome. Insight into the changes in the crop microbiomes could lead to healthier plants and safer food supplementation.
The effect of zinc deficiency and iron overload on endocrine and exocrine pancreatic function in children with transfusion-dependent thalassemia: a cross-sectional study
Authors: Mousa Suzan O. , Abd Alsamia Ebtihal M. , Moness Hend M. , Mohamed Osama G.
Published: October 2021

Background

Children with transfusion-dependent thalassemia (TDT) suffer from secondary hemosiderosis and the delirious effects this iron overload has on their different body organs, including the pancreas. They are also more prone to develop zinc deficiency than the general pediatric population. This study aimed to determine the effect of zinc deficiency and iron overload on the endocrine and exocrine pancreas in TDT children.

Methods

Eighty children, already diagnosed with TDT, were included in this study. We assessed the following in the participant children: serum ferritin, serum zinc, endocrine pancreatic function (oral glucose tolerance test (OGTT), fasting insulin level and from them, HOMA-IR was calculated), and exocrine pancreatic function (serum lipase and serum amylase).

Results

Forty-four TDT children had a subnormal zinc level, while 36 of them had a normal serum zinc level. TDT children with low serum zinc had significantly more impaired endocrine pancreatic function and an abnormally high serum lipase than children with normal serum zinc,p < 0.05 in all. Serum zinc was significantly lower in TDT children with serum ferritin above the ferritin threshold (≥2500 ng/ml) than those below (59.1 ± 20.2 vs. 77.5 ± 28.13),p = 0.02. TDT children, having a serum ferritin ≥2500 ng/ml, had significantly more frequently impaired endocrine pancreatic function and abnormally high serum lipase than TDT children below the ferritin threshold,p < 0.05 in all.

Conclusion

In children with transfusion-dependent thalassemia,zinc deficiency aggravates iron-induced pancreatic exocrine and endocrine dysfunction.
Integrating patient management, reflective practice, and ethical decision-making in an emergency medicine intern boot camp
Authors: Yaylaci Serpil , Ulman Yesim Isil , Vatansever Kevser , Senyurek Gamze , Turkmen Suha , Aldinc Hasan , Gun Cem
Published: October 2021

Background

Integration of clinical skills, ethical decision-making, and reflection skills have emerged as cornerstones of clinical teaching in medical schools. This study aimed to detect whether a multimodal learning environment approach consisting of lectures, a drill, post-drill video debriefing, and written reflection in an emergency medicine rotation boot camp improves interns’ patient management skills, ethical decision-making, and reflection skills.

Methods

A multimodal learning environment was created by the collaboration of emergency medicine, ethics, and medical education specialists. Multiple educational techniques involving lectures, case discussions, and role-playing a crisis scenario were applied. Pre-test and post-test, debriefing on performances on video records, video-recorded performance assessment, and reflective essays about their own and group’s performances were used to assess various aspects of the student performances. Additionally, a meeting was organized with the presence of the authors to create qualitative data obtained through the program evaluation meeting conducted on three themes: influences of teaching methods, students’ performances, and common achievements and mistakes of students.

Results

133 students participated. Post-test multiple-choice question (MCQ) test scores were slightly higher than pre-test. A low and medium correlation was detected among pre-test and post-test patient management problem (PMP) and reflection scores, which was more prominent for female students. Multiple linear regression showed that pre-test and post-test PMP scores significantly contributed to reflection scores. These results might support that better patient management predicts more robust reflective practice. Teachers observed that students appreciated being inspired by well-performing peers, particularly noting the empathic needs of patients, companions, and other health professionals. However, students overlooked summoning forensic or social services and were inhibited by the pressure of the contextual traits of the drill.

Conclusion

The multimodal learning environment created by multidisciplinary collaboration contributed to the improvement of components of situational awareness of the interns: patient management skills, ethical decision-making, and reflective practice. During this research, we created a toolbox better to capture the richness and diversity of student interactions. Considering the scarcity of context-specific assessment methods and widespread use of MCQs or generic scales for higher-order thinking skills in medicine, this study might be regarded as a step forward in that context.