Evaluation Of Alternative Methods Research Articles

Assessment of Early Vascular Aging Ambulatory Score (EVAAs): A Large Population-based External Validation Study.

Pulse Wave Velocity (PWV) remains the gold-standard method to assess Early Vascular Aging (EVA) defined by arterial stiffness. However, its high cost, time-consuming process, and need for qualified medical staff shows the importance of identifying alternative methods for the EVA evaluation. In order to simplify the process of assessing patients' EVA, we recently developed the Early Vascular Aging Ambulatory score (EVAAs), a simple tool to predict the risk of EVA. The aim of the present study was the external validation of EVAAs in an independent population. Eight hundred seventy-nine (46.3% men) patients who were referred to our Hypertension ESH Excellence Center were included in this study. The mean age was 46.43 ± 22.87 years. EVA was evaluated in two different ways. The first assessment included c-f PWV values, whereas the second one included EVAAs without the direct measurement of carotid-femoral PWV. The null hypothesis was that the prediction of EVA based on EVAAs does not present any statistically significant difference compared to the prediction based on the calculation from c-f PWV. Mean squared error (MSE) was used for the assessment of the null hypothesis, which was found to be 0.40. The results revealed that the EVAAs show the probability of EVA with 0.98 sensitivity and 0.75 specificity. The EVAAs present 95% positive predictive value and 92% negative predictive value. Our study revealed that EVAAs could be as reliable as the carotid-femoral PWV to identify patients with EVA. Hence, we hope that EVAAs will be a useful tool in clinical practice.

Playing with data differently: engaging with autism and gender through participatory arts/music and a performative framework for analysis.

There are increasing demands for Participatory Arts-Based (PAB) programs involved in health research to better evidence outcomes using robust quantitative evaluation methodologies taken from science, such as standardized questionnaires, to inform commissioning and scale-up decisions. However, for PAB researchers trying to do this, barriers arise from fundamental interdisciplinary differences in values and contexts. Researchers are required to navigate the tensions between the practice-based evidence produced by the arts and the evidence-based practice sought by psychologists. Consequently, there is a need for interdisciplinary arts-science collaborations to produce alternative methods of evaluation that are better aligned to PAB approaches, and which combine systematic rigor with a sensitivity to the values, contexts and strengths of this approach. The current article centers on the development of an alternative transdisciplinary analytic tool, the Participatory arts Play Framework (PP-Framework), undertaken as part of an arts-psychology collaboration for a UK AHRC-funded PAB research project: Playing A/Part: Investigating the identities and experiences of autistic girls. We present details of three stages in the development of the PP-Framework: 1. preliminary emergence of the framework from initial video analysis of observational data from participatory music and sound workshops run for 6 adolescent autistic girls (aged 11-16); 2. identification and application of modes of engagement; and 3. further testing of the framework as an evaluation tool for use in a real-world setting, involving professional musicians engaged in delivery of a creative music project at a center for homeless people. The PP-Framework maps types of participation in terms of performative behaviors and qualities of experience, understood as modes of play. It functions as a vehicle for analyzing participant engagement, providing a tool predicated on the processes of working in creative participatory contexts while also being sensitive to the esthetic qualities of what is produced and capable of capturing beneficial changes in engagement. It offers a conceptual approach for researchers to undertake observation of participatory arts practices, taking account of embodied engagement and interaction processes. It is informed by understandings of autistic performativity and masking in conjunction with an ecological understanding of sense making as being shaped by environments, social relations and sensing subjectivity. The framework has the potential to be a bi-directional tool, with application for both practitioners and participants.

Natural disease course modeling of achondroplasia to evaluate the efficacy of recifercept in the absence of a placebo control arm in phase II study.

While randomized, placebo-controlled, double-blinded clinical studies are the gold standard for evaluating the efficacy of investigational drugs, the use of placebo in children with achondroplasia should be limited because it provides no clinical benefit while exhausting study participants' treatment window. Recifercept is an investigational drug for treating children with achondroplasia aged 2-10 years. An alternative efficacy evaluation method, instead of a placebo control arm, was employed in the phase II study. Prior to participating in the phase II study, participants completed a natural history (NH) study. Based on the NH data, a multi-variate linear mixed effects natural disease course model of three anthropometric end points (standing height, sitting height, and arm span) was developed. The model was validated using published growth charts of children with achondroplasia. Subsequently, the model was used to simulate the natural growth trajectories (without any treatment) of the three anthropometric end points for the individuals enrolled in the phase II study. To quantify the efficacy of recifercept, the simulations were compared with the observations post-recifercept treatment in the phase II study. For all the tested doses of recifercept, at the individual level, the observations were comparable to the simulations at 6 and 12 months post-recifercept treatment, suggesting no treatment effect. The results contributed to the decision of terminating recifercept clinical development. This work delivers a framework that could eliminate the need for placebo in clinical trials yet provide sufficient evidence for evaluating the efficacy of an investigational drug.

Digital vs Conventional OSCE in Orthopedic Surgery: A Feasibility Cross-Sectional Study

Remote OSCEs (Objective Structured Clinical Examination) are an alternative evaluation method during pandemic periods but they have never been evaluated in orthopedic surgery. We aimed to evaluate whether remote OSCEs would be feasible, and efficient for assessment of undergraduate medical students. A cross-sectional study was performed. Thirty-four students were randomly assigned into 2 equal groups, either the conventional OSCE group or the digital OSCE group. Three types of skills were assessed: technical procedure, clinical examination, and radiographic analysis. Students were graded and they filled in a satisfaction questionnaire for both types of OSCEs. The mean score, out of 20, was 14.3 ± 2.5 (range 9.3-19) for the digital sessions, versus 14.4 ± 2.3 (range 10-18.6) for conventional sessions (p = 0.81). Bland Altman Plot showed that 88% of students scored within agreement. The average global feedback was different for item repeatability, relevance, and OSCEs preference (p < 0.0001, p = 0.0001, and p < 0.0001 respectively). However, they did not report differences for the item concerning the organization (p = 0.2). The results of this comparative study between digital and conventional OSCEs showed comparable distance learning scores between the 2 groups, whatever the skill assessed. However, the student's evaluation showed some reticence to conduct again OSCEs remotely.

Applicability investigation on failure assessment diagram of ASME code section XI - Appendix H for ferritic nuclear piping

The failure assessment diagram (FAD) is a widely used tool for evaluating the fracture acceptance of structural components. In addition to linear elastic fracture mechanics, elastic-plastic fracture mechanics, and limit load analysis, the ASME Code incorporated FAD as an alternative safety evaluation method for flaws in nuclear pipes starting from 2004 edition. This paper conducts a series of finite element elastic-plastic fracture mechanics analyses to establish the specific J–based FAD curves considering various loading and geometry conditions for ferritic pipes containing various circumferential flaws. By comparing with the suggested FAD of ASME Code Section XI - Appendix H, it is found that the radius-to-thickness ratio of pipes and the flaw depth influence the applicability of FAD, but with minor effects of crack length. In addition, the effects of material properties between base metal and weld materials on FAD are also discussed. The result of this work could be a reference when applying the FAD to evaluate the flawed piping for nuclear power plants.

Impact of Student Engagement in Language Support Classes Through Cooperative Learning: A Study of Pakistani Educational Institutions

Cooperative learning represents a pedagogical approach where students of varying abilities collaborate in small groups to achieve common goals. It involves the implementation of diverse learning activities to deepen understanding of the subject matter. Within these groups, learners engage in discussions, exchange ideas and knowledge, seek additional information, and present their findings to the class. Notably, cooperative learning prioritizes student-centeredness over teacher-centeredness, placing greater emphasis on learning objectives rather than performance targets. This shift also diminishes the focus on competitive assessments, urging educators to embrace alternative evaluation methods. Pressel (1992) asserts that cooperative learning enhances learning outcomes and retention, bolsters confidence and intrinsic motivation, and cultivates a more positive attitude toward academic and social abilities.

The phonetically balanced kindergarten assessment: An alternative evaluation method utilizing machine learning technology

This study investigates the use case of machine learning (ML) technologies to score the Phonetically Balanced Kindergarten (PBK) word test. The PBK, developed to test pediatric speech perception, is also used to monitor outcomes of cochlear implantation (CI) in children. Many factors contribute to high PBK score variability in CI users, but effects of scoring by human listeners are unclear. In this study, an alternate ML scoring method was developed. The Ursa classifier (Speechmatics, 2023) was used to recognize 100 PBK words spoken by 12 adults with normal hearing, speech, and language. The spoken words (n = 1200) were manipulated in six conditions (first and last phoneme deletion; high frequency filtering at 1, 2, 4, and 6 kHz), yielding 8400 stimuli. The classifier correctly recognized most of the unaltered words (true positive rate of 0.90; peak distribution density at 96%) and provided a null or incorrect response to altered stimuli as expected; most frequently for the first phoneme deletion and 1 kHz filtered conditions. Inter-class correlations showed comparable results between Ursa and 7 normal hearing human scorers (Cohens Kappa: 0.39). Thus, ML tools show promise in the scoring of the PBK; increasing the accuracy, efficiency, and reliability of this clinical assessment.

Vibration analysis of bio-inspired sandwich composite beam under rotating environment based on the Internet of Things technology

Sandwich composite materials with corrugated cores are mostly used in industries like aircraft, marine construction, automobiles, and construction. Sandwich composite constructions are made for their lightweight, high strength, and high stiffness, and also the sandwich core composite structures are useful for dynamic studies. A novel design inspired by a woodpecker beak microstructure creates fillet edge and champer edge designs. This novel design motivates us to achieve the energy absorbing results starting with free vibration studies followed by rotating environment vibration studies. ASTM E1876 standards, a non-destructive approach, are used to determine the material properties of carbon fiber-polylactic acid (CF-PLA) and glass fiber reinforced polymer (GFRP), along with alternative dynamic method (ADM) for core property evaluation. The hand lay-up technique is used for fabrication and evaluated for free vibration testing with appropriate boundary conditions. Internet of Things technology has been used for analyzing vibrations of sandwich structures in rotating environment setup with 250, 500, 750, and 1000 rpm. It was observed that the fillet edge pattern has a more efficient natural frequency than the champer edge pattern. Furthermore, the parametric evaluations were performed in various ply configurations in numerical simulations for free vibration and the rotating Environment. Also, the effective results are seen in fillet core bioinspired sandwich structure that achieves efficient stiffness in both free vibration and rotational environments, despite various boundary conditions and parametric circumstances. Therefore, the fillet edge 3D printed core design with particular GFRP factsheet orientation brings out the novelty of this research.

Development of an online evaluation awareness scale

The COVID-19 epidemic has precipitated a rapid and widespread adoption of online education, leading to its normalization in contemporary society. Online education is evident across several educational levels. However, assessing the efficacy and effectiveness of these training programs can only be achieved by implementing a suitable evaluation methodology. One of the primary challenges associated with online education is the difficulty in assessing its quality and effectiveness. One of the contributing factors to this issue is the instructor's lack of technological skills and knowledge relevant to online teaching. This research aims to develop a scale (Online Evaluation Awareness-OnEvA) to determine the instructors’ awareness of online evaluation. 165 participants’ data from 63 universities was used for exploratory factor analysis. The items of the scale are designed to measure awareness in both pedagogical and technological dimensions. The items in the pedagogical dimension include the essential competencies that instructors should possess, and alternative evaluation methods offered online. In the technological dimension, the items are created to determine instructors’ awareness of the use of technological platforms and tools. For the next step, a confirmatory factor analysis was performed to establish the scale’s construct validity with 161 instructors. Additionally, the scale’s internal consistency was determined to be high, with a Cronbach's alpha of .964. It is affirmed that this awareness scale developed within the scope of this research will contribute to the development of future models or frameworks related to the dimensions of evaluation knowledge in online learning.

Tensile testing as alternative evaluation method for enhanced adhesion of diamond-like carbon coatings with different titanium buffer layers

A tetrahedral amorphous carbon (ta-C) is widely used in industrial environments. However, application in extreme environments requires improved interfacial adhesion strength. This study proposes a new method to determine the adhesion strength of ta-C coating using the microtensile test, which is applied to improve the adhesion strength of ta-C coating by varying the Ti buffer layer microstructure. The tensile properties recorded in the stress-strain curve can be used to determine the difference between the absorbed energy and resistance to plastic deformation, which is then used to calculate fracture toughness. Moreover, to determine the adhesion strength, the crack density and spallation size were evaluated by measuring the cracks on the slip surface. The results show that compared to the columnar Ti buffer layer microstructure, the ta-C coating with a dense and flat Ti buffer layer microstructure more effectively improved the composite mechanical properties (columnar Ti layer H = ∼39 GPa, E = ∼430 GPa; dense Ti layer H = ∼48 GPa, E = ∼468 GPa), crack resistance (crack density = 6.4 % on columnar Ti layer; 1.5 % on dense Ti layer) and increased the dissipation energy during plastic deformation. Additionally, the dense Ti buffer layer microstructure reduced the wear rate (3.1 × 10−7 mm3/N∙m) and inhibited crack generation under long-term continuous frictional contact due to stress release in the ta-C coating. This finding clarifies the importance of the buffer layer with the suggested microstructural modifications for the wear resistance of ta-C coating.

TOPICAL ASPECTS OF IMPROVING THE ORGANIZATION OF PRODUCTION INVENTORY ACCOUNTING OF ENTERPRISES

The article studies some topical aspects of improving the organization of production inventory accounting, in particular, the issue of identification of this accounting category and the problems of accounting valuation of production inventories. The key components of the identification of the accounting category “production inventories” are determined. The author’s own definition is presented and substantiated, according to which production inventories are stocks (i. e., tangible current assets) held by an enterprise for the purpose of further one-time consumption (which will lead to a change in their natural and material form) in the process of production of products (works, services), maintenance of equipment, organization of management and marketing of products (goods). The article analyzes the issues of valuation of production inventories disposal. A comparison of the results of estimating the disposal of production inventories in the context of inflation using three main alternative methods of evaluation of disposal – the FIFO method, the weighted average cost method with price recalculation once a month and the weighted average cost method with price recalculation for each disposal. It is established that the use of the FIFO method in the context of inflation allows minimizing the accounting valuation of the disposal of production inventories, which in turn leads to maximizing the accounting valuation of the financial results of the reporting period and the value of inventory balances at the end of the period and, accordingly, improves the financial condition, increases the creditworthiness and investment attractiveness of the enterprise according to the financial statements. In terms of taxation, on the contrary, it is more attractive to use the weighted average cost method with prices recalculated once a month, since this method allows for a completely legal temporary optimization of the tax burden in terms of income tax in the conditions of inflation. The weighted average cost method with price recalculation for each disposal is recognized as a compromise option, the consensus of which is achieved by reducing the size of the effect. The issue of organizing the accounting and distribution of transportation and procurement costs by the methods of average percentage and direct distribution is studied. The disadvantages of the method of averaging transportation and procurement costs are identified and the expediency of direct distribution of transportation and procurement costs is substantiated, which allows improving the quality of accounting information on the movement of production inventories and the amount of costs generated as a result of their consumption.

Evaluasi Peran Dewan Pengawas Syariah di Indonesia

This research discusses the evaluation of the Sharia Supervisory Board's (DPS) role in the context of Islamic finance in Indonesia through a bibliometric approach. The research focuses on the development of literature related to DPS and its impact on Islamic finance. The rapidly evolving literature in Islamic finance (Siddiqui, 2016; Hasan, 2014) highlights the need for evaluating the role of DPS to ensure its effectiveness (Hasan et al., 2020). The study employs bibliometric methods to identify research trends, main topics, and the impact of literature on DPS. Key references include Siddiqui's work (2016) on the development of Islamic finance in Southeast Asia and Hasan's study (2014) on Sharia governance in Islamic banks. Additionally, Khan (2018) and Kettell (2011) provide in-depth insights into Islamic business ethics and the introduction of Islamic finance. Research findings from this analysis reveal literature gaps and affirm the relevance of bibliometric methods in measuring research impact, identifying trends, and addressing literature gaps. The implications support further research development with a focus on underexplored aspects, including regional exploration and cross-country comparisons. Recommendations involve developing alternative evaluation methods, practitioner case studies, and contributions to policy development related to the role of DPS, utilizing specific performance indicators, and exploring technology implementation in the context of Islamic finance. These suggestions are expected to guide future researchers in developing more in-depth and relevant studies in this continuously evolving domain.

Метадані наукових документів як складова системи інформаційних ресурсів «відкритої науки»

Open science is a movement that aims to make research results more accessible, including code, data, and scientific papers. It covers many different but often related aspects affecting the entire research life cycle, including open access to publications, open data of research, open source software, open workflows, public science, open educational resources and alternative methods of the research evaluation, including open peer review, expert reviews, etc. The key to effective application and integration of open science resources is their structured description based on the principles of completeness and necessity of meta-information, ease of use and interoperability. The units of such description are metadata. In fact, the quality of open resources begins with the quality of its metadata. This study does not cover the entire wide spectrum of open science resources. Its purposes are to define the system of characteristics that describe general and specific features of various types of scientific documents as a significant part of scientific knowledge of Open Science. To achieve the goal of the research it is defined a taxonomy of resources of open scientific documents and proposes an integrated system of their metadata. Proposed system of metadata is based on several classifier sets. It includes three major groups: internal characteristics – description of explicit features of the object of open knowledge (for example, the size or the type of the file), administrative characteristics – information about the object (authors, executers, etc.) and descriptive characteristics - information about the object’s content, its special features, links to other objects related to this. The metadata system is built based on the analysis of the existing metadata schemas and standards, search engines and digital libraries, and it takes into account similarity and specificity of each type of open documents.

A webcam-based machine learning approach for three-dimensional range of motion evaluation.

Joint range of motion (ROM) is an important quantitative measure for physical therapy. Commonly relying on a goniometer, accurate and reliable ROM measurement requires extensive training and practice. This, in turn, imposes a significant barrier for those who have limited in-person access to healthcare. The current study presents and evaluates an alternative machine learning-based ROM evaluation method that could be remotely accessed via a webcam. To evaluate its reliability, the ROM measurements for a diverse set of joints (neck, spine, and upper and lower extremities) derived using this method were compared to those obtained from a marker-based optical motion capture system. Data collected from 25 healthy adults demonstrated that the webcam solution exhibited high test-retest reliability, with substantial to almost perfect intraclass correlation coefficients for most joints. Compared with the marker-based system, the webcam-based system demonstrated substantial to almost perfect inter-rater reliability for some joints, and lower inter-rater reliability for other joints (e.g., shoulder flexion and elbow flexion), which could be attributed to the reduced sensitivity to joint locations at the apex of the movement. The proposed webcam-based method exhibited high test-retest and inter-rater reliability, making it a versatile alternative for existing ROM evaluation methods in clinical practice and the tele-implementation of physical therapy and rehabilitation.

A technique for assessing pulmonary perfusion in patients with previously treated COVID-19 pneumonia: clinical controlled non-randomized study

INTRODUCTION: Evaluating pulmonary lung perfusion in patients with previously treated COVID-19 infection may lead to a better understanding of long-term consequences of the disease, as well as may identify the changes determined by their symptoms. Further research is required for optimization of lung perfusion’s design parameters’ methods in order to implement those in clinical practice.OBJECTIVE: To determine the possibilities of an alternative method for evaluation of relative lung perfusion using three-dimensional ultrafast contrast-enhanced MRI on patients with previously treated COVID-19 pneumonia.MATERIALS AND METHODS: We examined 100 patients (28 male and 72 female, aged 22 to 70) who had laboratory-confirmed COVID-19 infection. The research was conducted using the three-dimensional ultrafast dynamic contrast-enhanced MRI based on 3D T1-weighted images. During the postprocessing, we received the values of rPBF (relative pulmonary blood flow), rPBV (relative pulmonary blood volume), and rMTT (relative mean transit time).Statistics. For non-linear dependence modelling we used natural spline transformation for time and interaction effect with a group. Intergroup comparison on integral measures was based on Kruskall-Wallis test (χ2), pair comparisons were based on Conover’s test (Δ). For multiple hypothesis testing correction, we used the false discovery rate (FDR). Comparisons were determined as statistically significant when p&lt;0.05.RESULTS: The differences in obtained values of lung perfusion among patient groups were confirmed both quantitatively (by rMTT, rPBV, rPBF) and qualitatively (by building the curves of contrast agent accumulation). Patients with previously treated COVID-19 demonstrate slower contrast agent transit and increased relative lung blood volume. Their accumulation curves have qualitative differences as well.DISCUSSION: We suggest a new method of evaluation of lung perfusion indicators in patients with previously treated COVID-19. We conducted an intergroup analysis based on the degree of lung damage during the acute phase of COVID-19 (with no infiltrativechanges, with minor lung damage, and major lung damage). The intergroup differences found are more significant for patients with lung damage (both minor and major) than for patients with no infiltrative lung changes during the acute phase of COVID-19.CONCLUSION: This method of evaluation of pulmonary perfusion is able to adequately characterize the functional lung conditions in patients with previously treated COVID-19 pneumonia. The chosen model is the most optimal.

Critical Current Density Measurements of Argyrodite Li6PS5Cl Solid Electrolyte at Ambient Pressure

Sulfide electrolytes including the argyrodite family (Li6PS5X, X = Cl, Br, I) exhibit high ionic conductivities and transference numbers and are regarded as promising electrolytes for all-solid-state lithium batteries. Although high ionic conductivity is a necessary requirement for feasible battery operation, other parameters are equally important and have often been neglected in efforts to realize all-solid-state batteries. The so-called critical current density (CCD) is among the more relevant parameters for application and indicates the maximum current an electrolyte can sustain before breakdown. When Li metal electrodes are used, this breakdown is often initiated by heavy dendrite formation and subsequent growth through the electrolyte layer, resulting in internal shorting of the cell. Very promising CCD values are reported for the argyrodite family of >1 mA cm−2 at elevated temperatures and pressures. However, non-standardized cell setups and testing procedures are employed, which renders a proper comparison of values impossible. Thus, this work investigates the impact of these often-overlooked parameters and aims at establishing more standard measurement procedures for solid electrolytes under ambient or almost ambient pressure. Furthermore, an alternative method for evaluation of CCD values is presented adopted from Tafel analysis.

Ki67 proliferation index in medullary thyroid carcinoma: acomparative study of multiple counting methods and validation of image analysis and deep learning platforms.

The International Medullary Thyroid Carcinoma Grading System, introduced in 2022, mandates evaluation of the Ki67 proliferation index to assign a histological grade for medullary thyroid carcinoma. However, manual counting remains a tedious and time-consuming task. We aimed to evaluate the performance of three other counting techniques for the Ki67 index, eyeballing by a trained experienced investigator, a machine learning-based deep learning algorithm (DeepLIIF) and an image analysis software with internal thresholding compared to the gold standard manual counting in a large cohort of 260 primarily resected medullary thyroid carcinoma. The Ki67 proliferation index generated by all three methods correlate near-perfectly with the manual Ki67 index, with kappa values ranging from 0.884 to 0.979 and interclass correlation coefficients ranging from 0.969 to 0.983. Discrepant Ki67 results were only observed in cases with borderline manual Ki67 readings, ranging from 3 to 7%. Medullary thyroid carcinomas with a high Ki67 index (≥ 5%) determined using any of the four methods were associated with significantly decreased disease-specific survival and distant metastasis-free survival. We herein validate a machine learning-based deep-learning platform and an image analysis software with internal thresholding to generate accurate automatic Ki67 proliferation indices in medullary thyroid carcinoma. Manual Ki67 count remains useful when facing a tumour with a borderline Ki67 proliferation index of 3-7%. In daily practice, validation of alternative evaluation methods for the Ki67 index in MTC is required prior to implementation.

Experimental Study of the Fatigue Life of Off-Highway Steel Wheels Using the Rim Section Test Approach

Wheels are structural components designed to sustain dynamic loads and avoid fatigue failures in service. For their validation, when standard fatigue tests are not feasible due to premature tyre wear, alternative methods should be used. In this paper, the rim section test approach is evaluated for the fatigue life assessment of steel rims for off-highway wheels. Customized specimens were studied by finite element analysis and subjected to bending fatigue tests to obtain the fatigue curve for the critical point of the rim. The results were also compared to fatigue data from standard tests of the base material, confirming the importance of testing components in conditions as similar as possible to the final ones in service. Additional measurements of the specimens’ surface hardness showed how this approach is valid to consider the effects of possible work hardening induced in the components by the production process. The residual stress state, instead, does not seem to be considered appropriately, since the initial compressive residual stresses of the component were released during the manufacturing of the specimens. The overall results of the study confirmed the suitability of the section test approach as an alternative method for the fatigue life evaluation of structural components. Moreover, it could be used for specific investigations concerning the influence of the production process parameters on wheel rims.

Discrimination rancidity degree of infant formula rice flour based on Headspace Solid-Phase Microextraction combined with Gas Chromatography–Mass Spectrometry as an alternative to sensory evaluation

To mitigating the serious threat of harmful volatile substances to the health of infants, an alternative method of odor evaluation were proposed based on Headspace solid-phase microextraction (HS-SPME) combined with Gas Chromatography–Mass Spectrometry (GC–MS) to discriminate the degree of rancidity of infant formula rice flour (IFRF). Inspectors can simply calculate the rancidity degree of infant formula rice flour according to the regression equation based on the concentration of rancidity markers. The results showed that the joint application of OPLS-DA, molecular sensory experiments, and unsaturated fatty acids (UFAs) degradation experiments could successfully recognize the rancidity markers without collinearity in multiple linear regression analysis. The rancidity markers curve fitting was helpful for the establishment of multivariate regression model of rancidity grading. The model had an accuracy of more than 92.90% by the verification of odor evaluation. The application of the model to investigate the market IFRF samples showed that about 3% of the samples collected in the experiment were unsuitable for infant feeding. Therefore, the established model was considered to be a robust and less workload method to replace the olfactory evaluation method for discriminating the rancidity degree of IFRF.

Application of flow cytometry for rapid bacterial enumeration and cells physiological state detection to predict acidification capacity of natural whey starters

Natural whey starter cultures are undefined microbial communities mainly consisting of thermophilic lactic acid bacteria (LAB). The technological pressure that shapes the natural whey starter community before and during the back-slopping procedure can impact the amount and viability of the different thermophilic LAB. Traditional culture-dependent analytical methods are useful for evaluating natural whey cultures based on plate enumeration with various culture media and are commonly used as self-control procedures in dairy items. These methods have high variability and require days to obtain results. As the dairy industry has been searching for a solution to this problem for a long time, researchers must explore alternative methods for the technological evaluation of natural whey and assessment of the health status of the thermophilic acidifying bacteria community in the cheesemaking process. The flow cytometry approach has been considered an alternative to classical methods in this work sector. This study compared bacterial enumeration by plate counting and flow cytometry on natural whey samples. Flow cytometry results showed positive agreement with a tendency to overestimate, linearity, and correlation with plate counting. Other parameters have also been introduced for evaluating a natural whey starter, measuring the physiological state of the cells. Specifically, cell-wall damage and metabolic activity were also evaluated, allowing us to quantify the number of cells even in sub-optimal physiological conditions.