Nonstandard Methods Research Articles

The Promise and Challenge of High Pressure Macromolecular Crystallography

Since its introduction in the early 1970s, high pressure crystallography (HPX) has shown great potential for the investigation of different types of matter. Using diamond anvil cells, HPX is an emerging technique that has been rapidly implemented, making it available to biologists, and there is immense potential for utilizing this technique in biological systems in the future. At the molecular level, high-pressure crystallographic investigation provides information on structural characteristics that not only determine the native conformation of a protein but also the conformations with higher free-energy, thus revealing function-related structural changes and properties that can be modified as a result of pressurization. The increase in the number of crystal structures of different macromolecules determined under high pressure over the last five decades can be ascribed mainly to two factors: the emergence of high-pressure cells with very large, open angles, and the advent of third generation synchrotron sources. The use of high pressure crystallography as a research tool has been shown to contribute to the advancements in the basic fields of biochemistry (protein misfolding and aggregation), biophysics (protein stability), and biotechnology (food processing). Presently, with a growing interest in biomedicine and nanotechnology, this nonstandard method appears to be a valid instrument for probing more challenging and complex systems. In this review, we present the method, highlight a selection of recent applications, and describe challenges for high pressure macromolecular crystallography (HPMX).

A robust numerical scheme for singularly perturbed differential equations with spatio-temporal delays

In this article, we proposed and analyzed a numerical scheme for singularly perturbed differential equations with both spatial and temporal delays. The presence of the perturbation parameter exhibits strong boundary layers, and the large negative shift gives rise to a strong interior layer in the solution. The abruptly changing behaviors of the solution in the layers make it difficult to solve the problem analytically. Standard numerical methods do not give satisfactory results, unless a large mesh number is considered, which needs a massive computational cost. We treated such problem by proposing a numerical scheme using the implicit Euler method in the temporal variable and the nonstandard finite difference method in the spatial variable on uniform meshes. The stability and uniform convergence of the proposed scheme have been investigated and proved. To demonstrate the theoretical results, numerical experiments are carried out. From the theoretical and numerical results, we observed that the method is uniformly convergent of order one in time and of order two in space.

MULTI-EXPERIMENTAL INVARIANTS FOR CHEMICAL REACTIONS IN A GRADIENTLESS REACTOR

New regularities of complex nonlinear chemical reactions proceeding through an arbitrary number of nonlinear stages in an open and closed isothermal gradientless reactor are described, regardless of the type of kinetic law (ideal law of acting masses, non-ideal kinetics of Marceline De Donde, etc.). For such reactions in an open reactor, the exact independent autonomous (not explicitly time-dependent) linear stoichiometric conservation laws are violated, but more general relations representing linear ordinary differential equations with respect to stoichiometric combinations of reagents are fulfilled. These equations have exact analytical solutions, which are non-autonomous nonlinear stoichiometric invariants based on a single mono-experiment with given initial conditions. The disadvantage of these ratios is their obvious dependence on time, which makes it difficult to verify them accurately in practice. The paper describes a non-standard method for obtaining autonomous invariants of an open gradient-free reactor, which are performed at any moment of the reaction transition process, are applicable to any nonlinear reactions with any kind of kinetic law of stages and are easily tested in practice. The method uses the ideas of dual- and multi-approaches that allow using the results of several non-stationary experiments conducted under any starting conditions. It is shown that using this method, it is possible to construct almost any number of partial nonlinear stoichiometric invariants for any given pairs of a series of multiexperiments. This allows them to be repeatedly rechecked and to increase the reliability of the identification of the reaction mechanism when solving the inverse problem in practice. The results obtained are illustrated by examples of specific reactions.

Clinical Use of the ImmunoCAP Inhibition Test in the Diagnosis of Meat Allergy Caused by a Tick Bite in an Adult Male with No Previous Atopic History.

(1) Background: alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergic reaction. This is a type of food allergy to red meat and other mammalian products (e.g., gelatin). In Poland, this problem seems to be rare or, more likely, very underdiagnosed. The diagnosis of AGS is difficult. It seems that the knowledge about this syndrome is insufficient. There are no effective diagnostic tools able to clearly diagnose this cross-reactive allergy. This paper presents the clinical application of a non-standard method in the diagnosis of a cross-reactive allergy using the example of AGS. (2) Methods: standard tests for in vitro allergy diagnostics and the non-standard ImmunoCAP inhibition test(IT) were carried out for serum collected from a patient with a red meat allergy. (3) Results: the serum concentration of anti-α-Gal IgE was very high (302 kUA/L), and IgE antibodies toanti-mammalian-meat allergens were found. The level of IgE antibodies to mammalian meat allergens decreased after blocking on α-GAL-CAP. The concentration of anti-α-Gal IgE decreased after blocking on CAPs coated with various mammalian meat allergens. Blocking with allergens of poultry meat did not affect the concentration of anti-α-Gal IgE. (4) Conclusions: the ImmunoCAP ITseems to be a useful tool in the diagnosis of cross-reactive allergies. Based on their clinical history and test results, the patient was diagnosed with AGS caused by a primary sensitization to α-Gal after a tick bite. This is the second case of AGS described in Poland and the first in Pomerania.

Singularly perturbed reaction diffusion problem with large spatial delay via non-standard fitted operator method

In this article, a numerical method for singularly perturbed partial differential equations of the reaction-diffusion type with a large spatial delay is constructed. The method is developed using the Crank-Nicolson method for time derivative and a non-standard finite difference method for spatial derivative on a uniform mesh. Due to the presence of a small perturbation parameter, which multiplies the highest order derivative term, the solution exhibits twin boundary layers. The solution to the problem also shows an interior layer as a result of the delay in the spatial variable. To enhance the order of convergence, the Richardson extrapolation technique is applied. The convergence analysis of the proposed scheme is given. It is proved that the resulting scheme is uniformly convergent of fourth-order accurate in both space and time variables. Numerical experiments are conducted, and the results are in agreement with the theoretical findings. In addition, comparisons are performed, and the results show that the proposed scheme gives more accurate solutions and a higher rate of convergence than previous findings in the literature.

Validation and verification of measurement methods: opinions and views

A brief comparative analysis of the concepts and procedures of "validation" and "verification" appeared in the national regulatory framework in relation to measurement techniques over the introduction of GOST ISO/IEC 17025-2019 which set the requirements for the competence of testing and calibration laboratories is carried out. Conditions for using a specific technique in an analytical laboratory providing reliable results of analyses are formulated proceeding from the regulatory documents: non-standard methods developed by a given laboratory and standard methods but used outside the scope or somehow modified, are the subject to validation; standard methods validated by another laboratory, as well as the methods developed by another laboratory and certified by an authorized organization are to be verified.

Some standard and nonstandard finite difference schemes for a reaction–diffusion–chemotaxis model

Abstract Two standard and two nonstandard finite difference schemes are constructed to solve a basic reaction–diffusion–chemotaxis model, for which no exact solution is known. The continuous model involves a system of nonlinear coupled partial differential equations subject to some specified initial and boundary conditions. It is not possible to obtain theoretically the stability region of the two standard finite difference schemes. Through running some numerical experiments, we deduce heuristically that these classical methods give reasonable solutions when the temporal step size k k is chosen such that k ≤ 0.25 k\le 0.25 with the spatial step size h h fixed at h = 1.0 h=1.0 (first novelty of this work). We observe that the standard finite difference schemes are not always positivity preserving, and this is why we consider nonstandard finite difference schemes. Two nonstandard methods abbreviated as NSFD1 and NSFD2 from Chapwanya et al. are considered. NSFD1 was not used by Chapwanya et al. to generate results for the basic reaction–diffusion–chemotaxis model. We find that NSFD1 preserves positivity of the continuous model if some criteria are satisfied, namely, ϕ ( k ) [ ψ ( h ) ] 2 = 1 2 γ ≤ 1 2 σ + β \frac{\phi \left(k)}{{\left[\psi \left(h)]}^{2}}=\frac{1}{2\gamma }\le \frac{1}{2\sigma +\beta } and β ≤ σ \beta \le \sigma , and this is the second novelty of this work. Chapwanya et al. modified NSFD1 to obtain NSFD2, which is positivity preserving if R = ϕ ( k ) [ ψ ( h ) ] 2 = 1 2 γ R=\frac{\phi \left(k)}{{\left[\psi \left(h)]}^{2}}=\frac{1}{2\gamma } and 2 σ R ≤ 1 2\sigma R\le 1 , that is σ ≤ γ \sigma \le \gamma , and they presented some results. For the third highlight of this work, we show that NSFD2 is not always consistent and prove that consistency can be achieved if β → 0 \beta \to 0 and k h 2 → 0 \frac{k}{{h}^{2}}\to 0 . Fourthly, we show numerically that the rate of convergence in time of the four methods for case 2 is approximately one.

Achieving nursing students' clinical practice hours during the COVID-19 pandemic: Effects of alternative and nonstandard practicum methods.

The aim of this study is to examine nursing students' experiences of alternative and nonstandard practicum methods used during the Coronavirus Disease 19 (COVID-19) pandemic and the associations between these experiences and nursing students' anxiety with clinical decision-making. Nursing students experiencing alternative clinical practice methods during the COVID19 pandemic have expressed regrets about being unable to experience direct nursing care and doubts about their clinical decision-making in actual clinical settings as a nurse in the future. Online surveys were distributed to 239 third-year nursing students through a link in an email. Data were collected from December 2020 to January 2021. Approximately 80% of participants in the Fall 2020 semester experienced an alternative clinical practice method. The extent of time spent experiencing alternative clinical practice methods and satisfaction with the clinical practicum were associated with anxiety about clinical decision-making. Although the pandemic continues, nursing students' clinical practice is needed in a clinical setting as much as possible to reduce the anxiety about clinical decision-making. During the pandemic, clinical nurse educators and clinical managers should work and communicate more closely to facilitate the students' clinical practice.

Unifying a posteriori error analysis of five piecewise quadratic discretisations for the biharmonic equation

Abstract An abstract property (H) is the key to a complete a priori error analysis in the (discrete) energy norm for several nonstandard finite element methods in the recent work [Lowest-order equivalent nonstandard finite element methods for biharmonic plates, Carstensen and Nataraj, M2AN, 2022]. This paper investigates the impact of (H) to the a posteriori error analysis and establishes known and novel explicit residualbased a posteriori error estimates. The abstract framework applies to Morley, two versions of discontinuous Galerkin, C 0 interior penalty, as well as weakly overpenalized symmetric interior penalty schemes for the biharmonic equation with a general source term in H −2(Ω).

ОБ ОЦЕНКЕ СНИЗУ РЕШЕНИЙ СЛАБО НЕЛИНЕЙНОГО ВОЛЬТЕРРОВА ИНТЕГРО-ДИФФЕРЕНЦИАЛЬНОГО УРАВНЕНИЯ ВТОРОГО ПОРЯДКА С ЗАПАЗДЫВАНИЯМИ

Sufficient conditions are established for lower bounds and tending to infinity as the argument of solutions to a weakly non-linear second-order Volterra integro-differential equation with delays on the half-axis grows unbounded. For this purpose, a non-standard method of reduction to a system, the method of transforming the equations of V. Volterra, the method of partial cutting, the method of integral inequalities with delays and the method of estimating solutions from below Yu.A. Ved are developed. It is shown that solutions with initial data from a certain manifold have lower bounds, and such solutions tend to infinity according to the exponential law with unlimited growth of the argument. This article proposes a technique for solving the problem of estimating from below on the half-line solutions of a weakly nonlinear Volterra-type integro-differential equation of the second order with delays, while the main role is played by the non-standard method of reduction to the system and the method of estimating solutions from below Yu.A.Ved (1965).

Searches for Extremely Metal-poor Galaxies Using Arecibo Legacy Fast ALFA–Selected Dwarf Galaxies * * Based in part on observations obtained with the Hobby–Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

We present a study of nearby dwarf galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) blind H i survey. A primary goal of the project was to utilize a nonstandard selection method with the hope of detecting previously unrecognized extremely metal-poor (XMP) galaxies. The study was motivated by the recent discovery of two XMP galaxies, Leo P and Leoncino, which were both originally found via the ALFALFA survey. We have obtained narrowband Hα images for 42 dwarf systems, many of which are located in the Local Void in front of the Pisces–Perseus Supercluster. Spectra for 11 of the best candidates resulted in the determination of metal abundances for 10 of the systems. None were found to be extremely metal-poor, although one system (AGC 123350) was found to have an oxygen abundance of log(O/H)+12 = 7.46, or ∼6% solar. One of the galaxies in our sample exhibits a high oxygen abundance for its luminosity, suggesting the possibility that it may have a tidal origin.

Psychometric investigation of the affiliate stigma scale in Mexican Parkinson's disease caregivers: Development of a short form.

Parkinson's disease (PD) caregivers, particularly in Latin America, may experience high levels of affiliate stigma due to their association with a person having a disability. The most common measure used of this construct in the literature, the Affiliate Stigma Scale, was validated using non-standard and questionable methods. The purpose of this study was to investigate the factor structure and psychometric properties of the Spanish version of the Affiliate Stigma Scale with PD caregivers in Mexico using more widely accepted psychometric approaches including confirmatory and exploratory factor analyses (CFAs, EFAs). A sample of 148 PD caregivers from Mexico completed this measure, as well as indices of caregiver burden and anxiety. Initial CFAs revealed that the data did not fit either the originally proposed one-factor or three-factor structures. An EFA was then conducted which was unable to discern any factor structure. Upon instituting a stepwise removal alpha-if-item-deleted process, a 5-item Affiliate Stigma Scale Spanish Short Form was retained with an adequate Cronbach's alpha, good convergent validity, and a Short Form CFA generally indicating adequate fit. The new Spanish Affiliate Stigma Scale Short Form holds promise for more appropriately measuring affiliate stigma likely in general but particularly in Spanish and among PD caregivers. The Short Form can assist not only in assessing levels of caregiver affiliate stigma, but in creating novel interventions to help support caregivers and decrease stigma.

Intercomparison exercises as a tool for improving the quality of radiochemical measurements in drinking waters – Radon-222 determinations

The results of a European intercomparison on 222Rn in water were analyzed to evaluate the performances of standard and non-standard methods. Then, results obtained with a specific LSC method (ISO 13164–4) based on two-phase liquid scintillation counting which has been employed by a considerable number of participants were examined in detail. This ISO LSC method was proved to be accurate, reliable and its reproducibility has been also sufficient. The intercomparison could be used as a collaborative study and the analysis of its results allowed to estimate the method reproducibility.

The analysis of the solution of the Burgers–Huxley equation using the Galerkin method

AbstractMany scientific methods have been proposed to solve the Burgers–Huxley equation. Among these famous methods, little or nothing has been mentioned in the literature about the coupling of the nonstandard finite difference method in the time and the Galerkin together with the compactness methods in the space variables. We exploit this gap and present a reliable technique aimed to use this coupling technique and show that the solution of the problem under investigation is uniqued in appropriate spaces to be defined. We proceed to show that the numerical solution obtained from the designed scheme is stabled and converges in the as well as the H1‐norms. Furthermore, we use examples together with some numerical experiments to justify the validity of our theoretical results.

Covertvasion: Depicting threats through covert channels based novel evasive attacks in android

Privacy and security issues concerning mobile devices have substantial consequences for individuals, groups, governments, and businesses. The Android operating system bolsters smartphone data protection by imposing restrictions on app behavior. Nevertheless, attackers conduct systematic resource analyses and divert privacy-sensitive information from plain view. They employ evasive mechanisms to evade system monitoring and create an illusion of benign and non-sensitive communication. Furthermore, covert channels amplify the impact of these malicious activities by facilitating information transfer through non-standard methods. The purpose of this research is to shed light on these novel threats targeting Android systems. The study delves into security and privacy attacks that compromise sensitive user information. The methodology leverages evasion concepts and employs sound-specific covert channel communication, particularly ultrasonic channels. This research work introduces novel evasive attacks, namely Prime-Composite Evasive Information Invasion (PCEII) and File-lock-based Evasive Information Invasion (FEII), both relying on covert channel communication. These unique variants of attacks successfully evade user data within a few milliseconds for both noisy as well as non-noisy environments and do not show any signs of detection by antivirus mechanisms like Anti-Virus Guard (AVG), 360 security, etc. and state-of-the-art tools such as TaintDroid, MockDroid and others. The paper not only assesses their impact on the privacy and security of information but also introduces avenues for their detection and mitigation.

Consolidation of loose foundation soil for esplanade project in Kaliningrad

The article presents the practical experience of pre-construction compaction of loose water-saturated clay foundation soils during the construction of Paradnaya Embankment in Kaliningrad. The engineering and geological conditions of the embankment construction site were complicated by the occurrence of a significant thickness (up to 15 m) of highly compressible flowing silts from the surface. The base preparation was carried out by preliminary compaction of loose soils with the ballasting embankment using vertical geodrains. The geotechnical monitoring system at the site was implemented after the construction of the ballasting embankment, in connection with which the designers made a premature conclusion that 90% of the degree of consolidation of soft soils according to the readings of pore pressure sensors was reached only 2 months after the filling of the ballasting embankment. The authors of the article analyzed the calculation methods of the consolidation process used in the design and the results of geotechnical monitoring. A repeated prediction of deformations of the soil mass from its compaction by the ballasting embankment was performed by a numerical method, taking into account the nature of the transfer of the load to the foundation, as well as the presence of shore protection structures of the embankment. A non-standard method was used to assess the total settlement of the ballasting embankment and the degree of consolidation of the foundation in the absence of correct monitoring data, which consists in determining the top elevations of loose soils by drilling control observation wells and comparing them with the results of engineering and geological surveys performed before the start of construction.

Упровадження сучасних інноваційних технологій у контексті професійної підготовки для розвитку фізичної культури в закладах вищої педагогічної освіти

The relevance of the research is due to the fact that the professional training of teachers is one of the most urgent issues of pedagogical science, and the professional training of a future physical education teacher in the new conditions of today is a process of personality formation that occurs in accordance with professional activity. One of the leading trends in the modernization of higher education in Ukraine is increasing attention to the problem of improving its quality. In institutions of higher pedagogical education, there is a problem of organizing an educational process focused on a student-centered approach, high-quality professional training of students, in particular: mastering professional knowledge, abilities and skills, personal and professional qualities, which will allow students of higher pedagogical education to use modern teaching tools and methods and be focused on successful professional activity with wide access to employment. The new requirements of society provide for the introduction of innovative approaches and non-standard methods in the entire educational process, and in the field of physical education – the development and use of innovative means and modern health technologies and fitness programs. The main resource for the implementation of innovative technologies in the process of physical education is the physical culture teacher of the educational institution. While building his knowledge system, a modern teacher must possess innovative technologies, modern fitness technologies, navigate a wide range of modern innovations and be able to implement them in the educational process.

INCREASING STUDENT’S MOTIVATION FOR PERFORMING CREATIVE TASKS THROUGH THE APPLICATION USAGE OF MODERN TEACHING METHODS

In the Bachelor’s degree curriculum of the new specialty Pedagogy of Fine Arts and Graphic Design, the main place is occupied by creative tasks. In order to increase the desire and creative charge, a non-standard method with a game character was applied in the process of teaching the new content and its reflection in practical activity was also observed. The purpose of this publication is to reveal whether such game methods are effective in working with students of creative disciplines. Does a non-standard approach in presenting new learning content will increase the students‘ motivation for learning and creative thinking? What is the place of visual intelligence as a key factor in the competencies required in the acquisition of knowledge in the field of Graphic Design. The method of Аttributive Analysis was chosen as a way of self-evaluation of the conducted activity. This activity analysis is an interesting, significant method, due to its applicability in various spheres of human activity, including pedagogical. Through the scheme created by Vladimir Belich of Attributive Analysis, which begins with Motivation and ends with the Result, an answer is given to the question: “Is the need for self-improvement, learning, training, creativity, realization, etc.has satisfied or not.” The pedagogical activity conducted and analyzed through this method is an experiment that represents the use of a competitive game-book in the process of passing new knowledge on the students of the topic of Pictogram. The aim of the game is to provide the students with a puzzle of pictographic images. It must be assembled and guessed by decoding the content that the individual images represent. The use of this type of analysis visually traces and makes sense – Is the didactic path to a task with increased difficulty correct.

On the Asymptotic Stability of Discrete Crocodilians Model

The sex ratio of crocodiles is strongly biased towards females, often as high as 10 females to 1 male. In crocodilians, the temperature of egg incubation is the environmental factor determining sex. If the temperature is low, around 30˚C, the hatchlings are all females. Higher temperature, around 34˚C, hatch all males. This study was made to consider the asymptotic stability of a positive equilibrium point in a nonlinear discrete model of the basic nesting population model, which is described in three-region depending on the temperature of egg incubation. This model is based on key life-historical data and Murray’s research. To study above, we have applied the classical linearization method and P. Cull’s method and moreover, we employ non-standard discretization methods for later our Equations (6)-(8) and (15).

Stochastic Analysis for the Dynamics of a Poliovirus Epidemic Model

Most developing countries such as Afghanistan, Pakistan, India, Bangladesh, and many more are still fighting against poliovirus. According to the World Health Organization, approximately eighteen million people have been infected with poliovirus in the last two decades. In Asia, still, some countries are suffering from the virus. The stochastic behavior of the poliovirus through the transition probabilities and non-parametric perturbation with fundamental properties are studied. Some basic properties of the deterministic model are studied, equilibria, local stability around the stead states, and reproduction number. Euler Maruyama, stochastic Euler, and stochastic Runge-Kutta study the behavior of complex stochastic differential equations. The main target of this study is to develop a nonstandard computational method that restores dynamical features like positivity, boundedness, and dynamical consistency. Unfortunately, the existing methods failed to fix the actual behavior of the disease. The comparison of the proposed approach with existing methods is investigated.