fixed proportion
Recently Published Documents


TOTAL DOCUMENTS

80
(FIVE YEARS 23)

H-INDEX

12
(FIVE YEARS 2)

Author(s):  
K. Jayanthi ◽  
P. Pazhanisamy

The hydrogels poly (N-cyclohexylacrylamide-co-acrylamide/2-acrylamido-2-methyl-1-propanesodiumsulfonate) i.e.poly(NCA-co-AM/AMPSNa) (HG41,HG42,HG43&HG44) were synthesised via  free-radical copolymerization of NCA and (AM) in a fixed proportion  (50:50), but varying the ionic monomer-AMPSNa (0.1g,0.3g,0.5 d 0.7g) in a medium of mixture of water and methanol  at 60°C in an oil bath, Potassium persulfate (KPS) was used as an initiator, while N,N'-methylene-bisacrylamide (MBA) was used as a cross-linker. FT-IR spectral data, SEM, XRD, and TGA techniques were used to characterise the synthesised hydrogel (HG43). On changing pH(3.0, 5.0, 7.0 & 9.0), the amount of Bovine Serum Albumin (BSA) adsorption efficiency by  these hydrogels was evaluated. At pH 5.0, which is near to BSA's isoelectric point (4.7)., the maximum adsorption was found. BSA adsorption increased as the amount of AMPSNa increased. SEM and XRD were used to examine the BSA-adsorbed hydrogel (HG43). The antibiofilm abilities of the hydrogel (HG43) by Microtiter plate Assay(MTP), Fluorescence microscopy and SEMl against Staphylococcus aureus and Pseudomonas aureginosa displayed outstanding efficacy.


Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1792
Author(s):  
Silvia Paracchini

Around the world, about 10% people prefer using their left-hand. What leads to this fixed proportion across populations and what determines left versus right preference at an individual level is far from being established. Genetic studies are a tool to answer these questions. Analysis in twins and family show that about 25% of handedness variance is due to genetics. In spite of very large cohorts, only a small fraction of this genetic component can be pinpoint to specific genes. Some of the genetic associations identified so far provide evidence for shared biology contributing to both handedness and cerebral asymmetries. In addition, they demonstrate that handedness is a highly polygenic trait. Typically, handedness is measured as the preferred hand for writing. This is a very convenient measure, especially to reach large sample sizes, but quantitative measures might capture different handedness dimensions and be better suited for genetic analyses. This paper reviews the latest findings from molecular genetic studies as well as the implications of using different ways of assessing handedness.


2021 ◽  
Author(s):  
Jeff Goldsmith ◽  
Tomoko Kitago ◽  
Angel Garcia de la Garza ◽  
Robinson Kundert ◽  
Andreas Luft ◽  
...  

The proportional recovery rule (PRR) posits that most stroke survivors can expect to reverse a fixed proportion of motor impairment. As a statistical model, the PRR explicitly relates change scores to baseline values -- an approach that has the potential to introduce artifacts and flawed conclusions. We describe approaches that can assess associations between baseline and changes from baseline while avoiding artifacts either due to mathematical coupling or regression to the mean due to measurement error. We also describe methods that can compare different biological models of recovery. Across several real datasets, we find evidence for non-artifactual associations between baseline and change, and support for the PRR compared to alternative models. We conclude that the PRR remains a biologically-relevant model of recovery, and also introduce a statistical perspective that can be used to assess future models.


Stroke ◽  
2021 ◽  
Author(s):  
Howard Bowman ◽  
Anna Bonkhoff ◽  
Tom Hope ◽  
Christian Grefkes ◽  
Cathy Price

The proportional recovery rule states that most survivors recover a fixed proportion (≈70%) of lost function after stroke. A strong (negative) correlation between the initial score and subsequent change (outcome minus initial; ie, recovery) is interpreted as empirical support for the proportional recovery rule. However, this rule has recently been critiqued, with a central observation being that the correlation of initial scores with change over time is confounded in the situations in which it is typically assessed. This critique has prompted reassessments of patients’ behavioral trajectory following stroke in 2 prominent papers. The first of these, by van der Vliet et al presented an impressive modeling of upper limb deficits following stroke, which avoided the confounded correlation of initial scores with change. The second by Kundert et al reassessed the value of the proportional recovery rule, as classically formulated as the correlation between initial scores and change. They argued that while effective prediction of recovery trajectories of individual patients is not supported by the available evidence, group-level inferences about the existence of proportional recovery are reliable. In this article, we respond to the van der Vliet and Kundert papers by distilling the essence of the argument for why the classic assessment of proportional recovery is confounded. In this respect, we reemphasize the role of mathematical coupling and compression to ceiling in the confounded nature of the correlation of initial scores with change. We further argue that this confound will be present for both individual-level and group-level inference. We then focus on the difficulties that can arise from ceiling effects, even when initial scores are not being correlated with change/recovery. We conclude by emphasizing the need for new techniques to analyze recovery after stroke that are not confounded in the ways highlighted here.


Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Heng Xu ◽  
Xuliang Wu ◽  
Yatian Liu

Purpose This paper aims to theoretically investigate an online company’s optimal decision on its offline expansion strategy. In the past five years, many large online retailers and internet-based companies such as Amazon, Google, Alibaba, Tencent and JD.com have expanded their offline market but it was observed that they adopted different expansion strategies. Specifically, some of them expand the offline market by acquiring offline retailers, while some do so by purchasing a portion of offline retailer’s stake. This difference leads to a quite different structure in post-expansion market, having an impact on profit, consumer surplus and social welfare. The goal of this paper is to model such expansion strategies in a general way and complete studies on profits and welfare. Design/methodology/approach By constructing a Salop model with two offline retailers and one online company, this paper analyzes the case where the online company can expand its offline market by either acquiring or jointing (e.g. stakeholding) with one offline retailer. The former strategy (named Strategy A) allows the online company to fully control and capture residual claims of the offline retailer. With the adoption of the latter strategy (named Strategy C), on the other hand, the online company can obtain a fixed proportion of its offline partner’s quasi rent. In the price competition, the online company chooses its optimal offline expansion strategy by predicting its profit in the post-expansion market. Findings This paper found that the equilibrium crucially depends on the synergy effect due to online–offline integration, and such synergy also influences both consumer and social welfare. This study shows the various conditions on the synergy that affect an online company moves toward offline markets. Accordingly, this finding can assist online companies with or without retailing business to choose an optimal strategy when expanding offline markets. Moreover, by doing some necessary welfare analysis, this study shows that the online company’s offline expansion is not always benefiting consumers nor be socially desirable, which may shed some lights on the possible competition policy in the case where online companies practice in offline expansion. Originality/value Different from conventional wisdom in online-offline integration, the theory indicates that the offline expectation of online company may not always benefit consumers nor be socially desirable. Moreover, the findings also shed some lights on the possible competition policy in the case where online companies practice in offline expansion.


HOMEROS ◽  
2021 ◽  
pp. 29-34
Author(s):  
Nigiar ISGANDAROVA

This paper aims to articulate the problem of relationship between an individual and society and its outreach through literary texts. I argue that the paradigms of interrelation of women, men, and society, particularly in the communities with pivotal patriarchal status have been directly adapted to the concepts and theories of society development. In the history of philosophy and sociology, various paradigms of society have been developed; the most popular among them are associating society with a bio-organism, analyzing society and an individual from an anthropological point of view, constructing a functionalist approach to this problem. J.J. Rousseau, Spinoza, Diderot, R. Merton, E. Durkheim for centuries have attempted to define a society and highlight its essential features. In this research, the problem is developing through the literary texts of the prominent Azerbaijan writer Anar and his literary characters, focusing on their moral and ethical priorities. As a basis for our research, we have chosen the Robert Merton’s structural functionalism approach. In addition, I agree with many scholars who believe that the movement of history has a spiral shape and at each turn of this spiral, the assessment of the individual by society is equivalent to the totality of values determined by society itself. It is accepted that the number of moral values is stable, but their combination is changing, corresponding to the Fibonacci Sequence, where spirals have a fixed proportion determining their shape (Vauclair 2009). I propose that in all patriarchal societies, the mode of perception of a woman by a man occurs at the level of his genetic memory. Moreover, the memory dictates him the same values as it was centuries ago. The code has not been changed since the period of the Lost Paradise. We will trace this formula of stable genetic memory and changing forms of assessment in a male-dominant society on the examples of the literary characters in Anar’s “White harbor” and Edgar Poe’s “Ligeia”.


2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Amal Altallhi ◽  
Salwa Moray ◽  
Seham Shaban ◽  
Sahar Ahmed

<p>Nanocrystalline nickel oxide (NiO) and copper oxide (CuO) have been synthesized in a water-in-oil microemulsion. The as-synthesized samples were characterized by X-ray diffraction (XRD), Electron Spin Resonance (E.S.R.), transmission electron microscopy (T.E.M.), and Specific Surface Area (S.S.A.). The particle size of nickel oxide and copper oxide can be controlled from 10.0 to 21.5 and 12.5 to 25.0 nm, respectively, at a different time of calcination temperature with a fixed proportion of water, surfactant, and oil in the microemulsion. Also, the results showed that the specific surface area (89.96 m<sup>2</sup> g<sup>-1</sup>) and pore diameter (8.11 nm) of the prepared nano NiO are higher than the specific surface area (71.96 m<sup>2</sup> g<sup>-1</sup>) and pore diameter (3.71 nm) of the prepared nano CuO. An adsorption test was carried out to show the efficiency of these prepared NiO and CuO nanoparticles for the Adsorption of T.N.T. in an aqueous solution. The removal efficiencies of both nano NiO and CuO were achieved at 90.06% and 77.0%, respectively.<strong></strong></p><p>Additionally, NiO and CuO nanoparticles were regenerated for five cycles. The Kinetic models of Pseudo first-order and pseudo-second-order were described. The results demonstrated that T.N.T. adsorption on both nano adsorbents follows the pseudo-second-order model.</p>


2021 ◽  
Vol 266 ◽  
pp. 01016
Author(s):  
Y.Y. Chen ◽  
L.B. Zhang ◽  
J.Q. Hu ◽  
Z.Y. Liu

According to the inherent characteristics of long-distance oil and gas pipelines, the optimization of emergency resources allocation can be implemented to maximize the utilization of pipeline emergency resources under a certain cost of emergency investment. We built an improved solution of a multiple knapsack problem in a greedy algorithm, proposed maximizing Emergency Resources Factor (ERF) as the greedy strategy, and established the optimization model of emergency resources allocation. This model innovatively combines factors such as the centrality of rescue points, the risk of pipe sections, and the necessity of emergency resources. The results show that, compared to a conventional resource allocation in a fixed proportion, an optimized allocation can reduce resource shortage and redundancy by 2.660% and 1.051%, respectively. Therefore, this model can be used to control the initialization of resource allocation in emergency rescue points of long-distance oil and gas pipelines.


2020 ◽  
Vol 11 (2) ◽  
pp. 54-72
Author(s):  
Ján Šebo ◽  
Daniela Danková ◽  
Ivan Králik

The introduction of pan-European pension products in 2020 is associated with an ongoing debate on prescribing predefined saving strategy that would both deliver adequate performance and limit the down-side risk at the end of the saving horizon. Dynamic life-cycle saving strategies are generally accepted as a good risk-mitigation tool that can be individually set. Many research papers confirm the ability of life-cycle strategies to deliver high risk-reward outcomes. Objective of our paper is to test the ability of one-factor life-cycle saving strategies based on the age and/or the remaining saving horizon to deliver the promised value for PEPP savers. We constructed 18 saving strategies divided into three groups – static saving strategies with fixed proportion of equities, dynamic life-cycle strategies based on the age and/or remaining saving horizon, and quasi-active strategies combining two factors – the remaining saving horizon and price movement. We employed the model based on moving-block bootstrapping technique and performed simulations for various economic conditions. We have tested the expected saving performance combined with the down-side risk during the saving horizon. Our findings do not confirm the general findings on life-cycle saving strategies. We claim that having the age as the only factor defining the proportion of equities in the pension saving portfolio would not be optimal. However, we found that two-factor saving strategies look promising in delivering both lower down-side risk and higher performance over the saving horizon.


Sign in / Sign up

Export Citation Format

Share Document