Three-dimensional flow of Powell–Eyring nanofluid with heat and mass flux boundary conditions

This article investigates the three-dimensional flow of Powell–Eyring nanofluid with thermophoresis and Brownian motion effects. The energy equation is considered in the presence of thermal radiation. The heat and mass flux conditions are taken into account. Mathematical formulation is carried out through the boundary layer approach. The governing partial differential equations are transformed into the nonlinear ordinary differential equations through suitable variables. The resulting nonlinear ordinary differential equations have been solved for the series solutions. Effects of emerging physical parameters on the temperature and nanoparticles concentration are plotted and discussed. Numerical values of local Nusselt and Sherwood numbers are computed and examined.

A novel variant of GALC in a familial case of Krabbe disease:Insights from structural bioinformatics and molecular dynamics simulation

Krabbe disease or globoid cell leukodystrophy(GLD;MIM#245200)is a rare and fatal lysosomal storage disease with an autosomal recessive mode of inheritance that results from the deficiency of galactocerebrosidase(GALC;E.C.3.2.1.46),a lysosomal enzyme encoded by the GALC gene.1 GALC breaks down galactosylceramide,a cerebroside located mainly in the myelin sheath.Defects in GALC cause the accumulation of a cytotoxic metabolite,galactosylsphingosine or psychosine,which can be toxic to oligodendrocytes and Schwann cells.2 The failure to digest galactosylceramide triggers the formation of multi-nucleated globoid cells,causing severe demyelination,axonopathy,and neuronal death.3 The reported frequency of Krabbe disease is 1 in 100,000 live births with symptoms including irritability,loss of motor ability,spasticity,ataxia,visual dysfunction,seizures,andcognitive impairment.

Efficient construction of a substitution box based on a Mordell elliptic curve over a finite field

Elliptic curve cryptography has been used in many security systems due to its small key size and high security compared with other cryptosystems. In many well-known security systems, a substitution box (S-box) is the only non-linear component. Recently, it has been shown that the security of a cryptosystem can be improved using dynamic S-boxes instead of a static S-box. This necessitates the construction of new secure S-boxes. We propose an efficient method to generate S-boxes that are based on a class of Mordell elliptic curves over prime fields and achieved by defining different total orders. The proposed scheme is devel-oped in such a way that for each input it outputs an S-box in linear time and constant space. Due to this property, our method takes less time and space than the existing S-box construction methods over elliptic curves. Computational results show that the pro-posed method is capable of generating cryptographically strong S-boxes with security comparable to some of the existing S-boxes constructed via different mathematical structures.

生物入侵过程中的植物-土壤反馈:一种入侵植物的凋落物分解对其本地近缘植物的影响

植物入侵可通过正或负的植物-土壤反馈效应改变土壤的生物和非生物性质,从而影响入侵栖息地的土壤理化性质。许多入侵物种的凋落物分解可增加土壤养分,降低本地植物多样性,并导致进一步的植物入侵。关于入侵植物凋落物在不同土壤类型及深度分解及反馈效应的研究依然很少。本研究旨在明确入侵植物南美蟛蜞菊(Sphagneticola trilobata)凋落物在不同土壤类型和不同土壤深度条件下的分解情况及其对本地近缘植物蟛蜞菊(S.calendulacea)生理生长的影响。将装有南美蟛蜞菊凋落物的尼龙袋加入到不同深度(即0、2、4和6 cm)的砂土、营养土和粘土中,经6个月的分解后,回收凋落物袋并计算分解速率,随后在凋落物分解处理后的土壤中种植本地蟛蜞菊,并在生长期结束时测量其生理生态指标。研究结果表明,所有处理土壤类型中,凋落物在土壤深度为2和4 cm处分解后显著增加了土壤养分,而对本地蟛蜞菊的叶片叶绿素、叶氮含量等生长指标表现为负效应。因此,入侵植物南美蟛蜞菊凋落物分解对土壤养分表现为正的反馈效应,而对本地植物蟛蜞菊的生长表现为负效应。我们的研究结果还表明,入侵植物的凋落物分解对土壤和本地物种的影响还因凋落物分解所在的土壤深度而显著不同。未来的研究应侧重于入侵栖息地中更多本地和入侵物种的植物-土壤反馈效应,以及更多土壤类型和土壤深度的入侵植物凋落物效应。

Review of applying X-ray computed tomography for imaging soil-root physical and biological processes

Root growth process in soils has long been a matter of interest to soil and plant scientists.However the opaque nature of the soil has been a barrier to most research attempts aimed at unraveling the full root-soil processes.The traditional method of separating the roots from the growth media which is common practice tends to be destructive and defeats the purpose of such studies.It is ineffective in monitoring the interactions within the soil medium and as a result,a fast non-destructive technique is preferred.However,with computing and technological advancements,X-ray computed tomography(CT)has been found to be capable of meeting this need by imaging the processes which are of interest to researchers.Over the past three-four decades,the applications of the technology for imaging soil-root studies have attracted the researchers’widespread interests and the future looks more promising.The purpose of this review is to present an overview of CT applications in imaging root-soil processes.The main focus is on the use of soil-root interface researches and the way forward for such non-destructive analyses.

CFD simulation of sucrose flow field in the stem of greenhouse tomato seedling

Sucrose is the main constituent of assimilation transport from source to sink.In order to study the transport mechanism of sucrose,the sucrose at stem was taken as a research object and the sucrose flow field in tomato stem was analyzed using CFD ANSYS FLUENT simulation.The results showed that the sucrose pressure distribution was lower at bottom node and higher at middle node.The velocity of sucrose at different nodes was higher at the bottom node and lower at middle node and assimilation flow direction of the first,second,and third leaf from the bottom was towards the roots.The result of verification experiment showed that sucrose content measured at different nodes was higher at middle node than that of bottom node.Results of this study confirmed that ANASYS FLUENT can better simulate sucrose migration in greenhouse tomato stem.This study provides a new method for studying the partitioning mechanism of tomato assimilates in greenhouse.

Autosomal recessive cerebellar ataxia with spasticity due to a rare mutation in GBA2 gene in a large consanguineous Saudi family

The nonlysosomal glucosylceramidase b2(GBA2)gene encode an enzyme that catalyzes the hydrolysis of glucosylceramide to glucose and ceramide.Mutations in the GBA2 gene have been reported to cause hereditary spastic paraplegia,autosomal recessive cerebellar ataxia with spasticity,and Marinescu-Sjogren-Like Syndrome.In this study,we report the clinical features and genetic diagnosis of autosomal recessive cerebellar ataxia with spasticity due to a rare mutation in GBA2 gene in a large consanguineous Saudi family.We included a large consanguineous Saudi family with a presumptive clinical diagnosis of ataxia at King Abdulaziz Medical City in Jeddah,Saudi Arabia.The family included six affected individuals and four unaffected in addition to the parents.Whole exome sequencing(WES)was performed for the probandⅣ-5,and Sanger sequencing was used to confirm the variant in other family members.Segregation study was performed using DNA from the parents and siblings of the proband.Sequence analysis identified a homozygous variant c.2618G>A,p.(Arg873His)in GBA2 gene.The homozygous variant was identified in affected members of the family while the parents and the other four siblings were heterozygous carriers of the variant.One sibling was not available for genetic testing.The variant identified in our patients is classified as pathogenic considering the current evidence of the variant.Autosomal recessive cerebellar ataxia with spasticity is an extremely rare genetic disorder with very few cases reported in the literature.We conclude that the c.2617G>A mutation in GBA2 gene causes the loss of function with abolishment of the enzymatic activity that causes the disease.This report adds further evidence to support the pathogenicity of this variant.The patients had the classical clinical phenotype of cerebellar ataxia and spasticity consistent with previous reports in the literature.