Discriminant Formula Research Articles

Impact of Gas Accumulation on the Stability of Parallel Upward Ventilation in High-Temperature Sloped Shafts of Deep Wells

To explore the causes and influencing factors of wind flow oscillations in high-temperature inclined aisles of deep wells under parallel upward ventilation, this study conducts a comprehensive investigation using theoretical analysis and numerical simulations. Based on the kinetic analysis of gas flow, a discriminant formula for wind flow reversal in the side branch is derived. Further analysis identifies initial wind speed and branch length as key factors influencing the reversal. Both gas pressure and thermal pressure contribute to wind flow reversal in the side branch, and the opposing directions of these pressures cause high-temperature gas to periodically flow between the two branches, resulting in wind flow oscillations. A higher initial wind speed can effectively reduce the oscillation amplitude due to increased initial kinetic energy and a larger pressure difference, but it does not extend the oscillation duration. Increasing the branch length can suppress wind flow oscillations by increasing airflow frictional resistance and damping.

On Drinfeld modular forms of higher rank VII: Expansions at the boundary

We study expansions of Drinfeld modular forms of rank r≥2 along the boundary of moduli varieties. Product formulas for the discriminant forms Δn are developed, which are analogous with Jacobi's formula for the classical elliptic discriminant. The vanishing orders are described through values at s=1−r of partial zeta functions of the underlying Drinfeld coefficient ring A. We show linear independence properties for Eisenstein series, which allow to split spaces of modular forms into the subspaces of cusp forms and of Eisenstein series, and give various characterizations of the boundary condition for modular forms.

Critical appraisal of the utility of 13 discriminant formulas for distinguishing beta thalassemia trait from iron deficiency in patients with microcytic anemia and the introduction of a new formula in a USA population

Abstract Iron deficiency anemia (IDA) and beta thalassemia trait (ß-TT) are two frequent causes of microcytic anemia that often pose a diagnostic dilemma with implications for management. Many discriminant formulas have been proposed for distinguishing these two conditions. However, there is a need for independent verifications of these formulas to determine their applicability to other populations, particularly more diverse populations, as seen in the United States. To date, no study has been performed in the United States to evaluate the utility of these formulas in distinguishing both conditions. The study objective was to evaluate the utility and predictive values of 13 discriminant indices and formulas for distinguishing ß-TT from IDA in a US population. We investigated 13 formulas comprising only hematologic parameters available on all analyzers. The investigational population consisted of 238 patients with microcytic anemia; 165 with a hemoglobin electrophoresis diagnosis of ß-TT and 73 diagnosed with IDA by clinician review or iron studies. The study population comprised 55% black or African American, 35% White, 5% Asian, 1.2% Native American, and 2.5% unidentified. Receiver operating characteristic curves were employed to evaluate the diagnostic performances of the formulas. All investigated formulas had poor sensitivities but high specificities. The three best-performing indices or formulas from those previously proposed for distinguishing ß-TT from IDA were the RBC (sensitivity 62.2%, specificity 87.1%), Green and King (MCV2×RDW/100 hemoglobin, Hb) with a sensitivity of 65.4% and specificity of 82.6%, and Wongprachum et al. (MCV×RDW/RBC) – 10 Hb) with a sensitivity of 63.6% and specificity of 82.6%. Areas under the curve (AUCs) were 0.68 for the RBC and, 0.67 for both Green and King and Wongprachum formulas. The Youden indices were 0.49, 0.48, and 0.46, respectively. The Mentzer index had a sensitivity of 63.4%, specificity of 81.7% and Youden index of 0.45. We introduced a new formula comprising the sum of three of the most readily obtained red cell parameters (RBC + Hb + MCV). It had a Youden index of 0.95, sensitivity of 96.8, specificity of 98.0, and AUC of 0.97, significantly outperforming other formulas in our study population (p=0.00). This is the first study in the USA evaluating the utility of multiple indices for distinguishing ß-TT from iron deficiency anemia. The best performing formulas in other studies did not perform well in our population. This necessitated an introduction of a new formula that demonstrates excellent potential to address the unique diversity of the US population.

Forensic and clinical implications of scapula length: A radiological study in Delta State, Nigeria

Abstract Background: The morphometry of the scapula exhibits sexual dimorphism, which makes it crucial for sex determination in forensic contexts and guides orthopedic surgeons in the management of shoulder girdle fractures. Objective: This study aimed to establish population-specific discriminant formulas for sex determination using the scapula length from radiographs. Materials and Methods: This observational cross-sectional study retrospectively analyzed 200 postero-anterior chest radiographs (113 males and 87 females) from a referral hospital in Delta State, Nigeria. Inclusion criteria comprised fully ossified scapulae in patients aged 25–60 years. Scapula length was measured using digital calipers, and statistical analyses, including discriminant function analysis, were performed to create population-specific equations for sex prediction. Results: Males exhibited significantly longer scapulae than females. The right scapula length was longer and demonstrated higher overall accuracy (78.5%) in sex determination than the left scapula (75.0%). Combining right and left scapula lengths increased the accuracy to 83.0%. Conclusion: The study provides population-specific normative values for scapula length and highlights the sexual dimorphism of the scapula length. The length of the right scapula was more accurate in predicting sex (78.5%) and when combined with that of the left scapula, the accuracy increased (83.0%).

The method to predict damage of body areas due to occupational injury among firefighters

Background. Occupational injuries indicate the level of safety at work and are subject to controlled management. Impossible to eliminate entirely, injuries lend to minimization only. Injuries are investigated not only by medical professionals exclusively. At the same time, by knowing the occupational injury dynamics and the types of potential body injuries, we can prospectively assess the required capacities and resources to eliminate the consequences. The objective is to develop a tool to forecast the scale of occupational body injury in firefighters of the Federal Firefighting Service (FFS) of the EMERCOM of Russia.Methods. The paper analyses occupational injury reports for 2012–2021 produced by the FFS of the EMERCOM of Russia. Total 1769 injuries were registered and matched to injury groups contained in chapter XIX of the International Classification of Diseases and Behavioral Disorders (ICD-10). Personnel injury risks for different body parts are identified and calculated with adjustments for non-identified (absence of diagnoses in injury records) and poorly identified injuries (generalized diagnoses are given). The body injury risk level among the personnel was (11.96 ± 0.89) ∙ 10–4 injuries/(individual ∙ year), which was greater than the level of injuries – (9.19 ± 0.54) ∙ 10–4, since each case of injury correlated with an average of 1.3 diagnoses, with 1.4 in firefighters, including those involved in elimination of other emergency consequences, conducive of concomitant and combined injuries. The curves show high, positive and statistically significant congruence (r = 0.686; p < 0.05), suggesting the impact of identical (unidirectional) factors as an underlying cause. External impacts include mechanical injuries amounting to 83.6 %, burns – 11.6 %, heat syncope – 1.5 %, poisoning by combustion products – 3.3 %. The average age of the injured FFS personnel of the EMERCOM of Russia was (36.2 ± 0.3) years, including (10.2 ± 0.3) years of work experience, with the overall FFS forces standing at (191.3 ± 3.3) thousand people. Results and discussion. The predicted number of occupational injuries among the FFS personnel of the EMERCOM of Russia was calculated using the discriminant formula: y = (2.49 z1 + 0.21 z2 + 0.91 z3 + 0.68 z4 + 0.72 z5 + 0.71 z6 + 0.88 z7 + + 0.43 z8 + 1.87 z9 + 1.11 z10 + 1.11 z11)∙10–4 × (2.54∙10–4 t2 – 2.98∙10–2∙t + 1.72) × (–2.94∙10–4∙s2 – 1.76∙10–2 ∙ s + 1.24), where y is the number of occupational injuries of the FFS of the EMERCOM of Russia; x is the number of personnel (absolute); t is the average age, years; s is the average professional experience, years; z1–z11 is the predicted number of body damages (contained in chapter XIX of the ICD-10) derived by multiplying the corresponding coefficient by the number of firefighters per 10 thousand people (10–4): z1 is head (S00–S09), z2 is neck (S10–S19), z3 is chest (S20–S29), z4 is abdomen, lower back, lumbar spine and pelvis (S30–S39), z5 is shoulder girdle and shoulder (S40–S49), z6 is elbow and forearm (S50–S59), z7 is wrists and carpus (S60–S69), z8 is hip and thigh areas (S70–S79), z9 is knee and lower leg (S80–S89), z10 is ankle and feet (S90–S99), z11 is other external impacts, i.e. thermal and chemical burns (T20–T32), combustion by-product poisoning (T58–T59), heat syncope (T67.1). Linear discriminant formulas are provided to calculate body lesions split by categories of personnel (operational, preventive, technical and managerial personnel).Conclusions. The method allows to predict the total number of occupational injuries among firefighters, including injuries of certain body areas and thereby calculate the resources and efforts required for treatment and rehabilitation.

Switching dynamics of a Filippov memristive Hindmash–Rose neuron model with time delay

Considering the existence of magnetic induction effect with different intensities in the process of subthreshold and suprathreshold oscillations of bioelectrical activities, a non-smooth feedback strategy for memristive current with time delay is proposed, and then a four-dimensional Filippov Hindmarsh–Rose (HR) neuron model is established. The local stability and bifurcation patterns of delayed subsystems are qualitatively analyzed. Accordingly, the discriminant formula for the direction and stability of periodic solutions generated by Hopf bifurcation is obtained on the center manifold. Importantly, the stability of subsystems has switching behavior, which is accompanied by abundant hidden electrical activities under the effect of time delay. The theoretical analysis clarifies that the proposed feedback strategy leads to complex sliding mode dynamics, including sliding segments, various equilibrium points and sliding bifurcations. Meanwhile, the analytical conditions for motions of grazing, sliding, and crossing are developed and verified based on the flow switching theory. Moreover, the mechanism and evolutive rule of the self-excited and hidden sliding electrical activities are revealed by the fast-slow variable dissection method. Finally, it is verified that the time delay can not only induce bistable structures composed of the quiescent state and periodic bursting, but also eliminate the hidden sliding dynamics.

Study on Reconstruction of Condominium in the Metropolitan Area Using Real Estate Data

In Japan, there is concern about the impact of the growing stock of older condominiums on the buildings themselves and the surrounding environment, and immediate action is needed. While in other countries, repair, elimination, and retirement of aged condominiums are the mainstream methods, in Japan, reconstruction is sometimes used. This study proposes a new decision criterion using discriminant analysis to address the problem of the difficulty and long time required to build consensus for rebuilding older condominiums. Discriminant analysis used building attributes and other variables to differentiate and predict condominium properties that have been successfully reconstructed from those that were not. Simple and clear answers will enable non-expert judgment and aid in consensus building. Multiple discriminant formulas were obtained and compared for Tokyo and neighbouring cities, as well as by subdividing and adding up these subdivisions. At the same time, coefficients of variables were changed or added to increase the reliability of the equations. As a result, a new modified discriminant equation with a high degree of reliability that advances previous studies was obtained. In addition, through the process of creating the formula, we discovered a new option for determining whether or not to rebuild based on whether or not there is an excess floor-area ratio, which is generally considered to be the solution in Japan, by increasing the site area.

Research on Vibration Suppression of Nonlinear Tuned Mass Damper System Based on Complex Variable Average Method

Tuned mass dampers (TMDs) are widely used as vibration damping devices in engineering practice. However, during use, TMDs inevitably exhibit some nonlinear characteristics that may negatively impact engineering applications. To improve the practical performance of TMDs, the cubic nonlinear stiffness of the TMD is considered, and a nonlinear design is implemented. A numerical model of a single-degree-of-freedom main structure controlled by an NTMD is developed, and the steady-state amplitude solution of the system is obtained using the complex variable averaging method. The results show that a jump phenomenon may occur in the structure. To address this, a multivalued solution discrimination formula based on the complex variable averaging method is proposed. The discriminant formula for the jump phenomenon obtains the frequency ratio and nonlinear coefficient curves of the critical jump state, and four different system response areas are obtained. This helps the structure avoid the jump phenomenon while ensuring stability of the main structure and improving the control performance of the NTMD.

Study of the Roof Deformation Characteristics of Roadway Excavation Face and Unsupported Roof Distance

In order to address the issue of slow excavation speed caused by various factors affecting the stability of the roof in the excavation face and the unreasonable distance of the unsupported roof, a mechanical model of the roof in the excavation face area is established. This model is based on the superposition method in the material mechanics. The immediate roof deflection curve equation and the maximum unsupported roof distance discriminant formula of the heading head are derived. The allowable deflection is used as the discriminant method of the maximum unsupported roof distance. The calculation method of the key parameters in the formula is obtained and compared with the existing maximum unsupported roof distance calculation formula. Using the single-variable sensitivity analysis method and the bivariate interaction analysis method, we determine the key factors affecting the deformation of the roof in the excavation face and their interaction relationships. The results indicate that among the 10 factors affecting the deformation of the roof in the temporary support area of the excavation face, there are 3 key factors. Under unchanged geological and mechanical conditions, the deformation of the roof primarily depends on the length of the temporary support area and the temporary support load. To provide a practical example, we calculate the maximum unsupported roof distance of 30304 tailgate in the Yanghuopan Coal Mine to be 3.4 m. Numerical simulation and field monitoring results confirm that the deformation of the roof in the excavation face is minimal, and the stability of the rock is good.

Differentiation between Thalassemia Trait and Iron Deficiency Anemia Based on Low Hemoglobin Density and Microcytic Anemia Factor.

The most common causes of microcytic hypochromic anemia are thalassemia trait (TT) and iron deficiency anemia (IDA). Clinically, the differential diagnosis of TT and IDA is crucial, but it is typically challenging. Thus, in order to differentiate between TT and IDA, we seek to develop a new discriminative index on an automatic hematology analyzer utilizing the two new RBC characteristics of low hemoglobin density (LHD) and microcytic anemia factor (MAF). We recruited a total of 323 subjects, including 115 healthy controls, 83 TT, and 125 IDA. An automated hematology analyzer (DxH800, Beckman Coulter) was used to determine peripheral blood parameters; LHD and MAF were calculated using the parameters of MCHC, Hb, and MCV. The receiver operating characteristic (ROC) curve was used to determine the cutoff values and evaluate the diagnostic value for TT and IDA. LHD was significantly lower in TT than IDA, whereas MAF was higher. To distinguish between TT and IDA, a new formula based on LHD and MAF was developed, with a cutoff value of 0.5, AUC of 0.9706 (95% CI: 0.9503 - 0.9909), and specificity, sensitivity, positive predictive value, and negative predictive values were 92.91%, 91.36%, 89.16%, and 94.40%, respectively. The new formula has proven advantages over conventional indices, such as RDW-SD, MCV, MCH, etc. Conclusions: The RBC parameters LHD and MAF detected by hematology analyzer could be useful for screening for TT and IDA. Our new formula outperforms other discriminant formulas in the literature with high sensitivity and specificity, is simple, rapid, and can aid in early detection and management.

Determination of low‐temperature stress during the vegetative stage as a tool to predict plant yield in rice genotypes with contrasting tolerance levels

AbstractIn this study, the first aim was to develop a rapid and non‐destructive method for analysing rice genotypes' tolerance to low temperatures (LT) during the seedling stage. Using a growth parameter and a physiological parameter, a discriminant formula was developed to differentiate between tolerant and sensitive genotypes based on their LT tolerance score. The study identified several benefits of the discriminant formula, including its low classification error rate, scalability, and ability to be used in controlled and reduced environments. Additionally, a second study was conducted, which found a strong correlation between the LT tolerance score during the seedling stage and plant yield at the ripening stage in plants grown under field LT during the vegetative stage. Panicle weight was the main mediator of the effect of the LT tolerance score on plant yield, but the number of panicles per plant also played a role. Overall, the results suggest that the LT tolerance score can serve as an indirect selection factor for plants for both LT tolerance and plant yield. This is especially relevant for rice‐growing regions with temperate climates and LT at the beginning of the cultivation season.

Targeting the metabolic profile of amino acids to identify the key metabolic characteristics in cerebral palsy.

Cerebral palsy (CP) is a neurodevelopmental disorder characterized by motor impairment. In this study, we aimed to describe the characteristics of amino acids (AA) in the plasma of children with CP and identify AA that could play a potential role in the auxiliary diagnosis and treatment of CP. Using high performance liquid chromatography, we performed metabolomics analysis of AA in plasma from 62 CP children and 60 healthy controls. Univariate and multivariate analyses were then applied to characterize different AA. AA markers associated with CP were then identified by machine learning based on the Lasso regression model for the validation of intra-sample interactions. Next, we calculated a discriminant formula and generated a receiver operating characteristic (ROC) curve based on the marker combination in the discriminant diagnostic model. A total of 33 AA were detected in the plasma of CP children and controls. Compared with controls, 5, 7, and 10 different AA were identified in total participants, premature infants, and full-term infants, respectively. Of these, β-amino-isobutyric acid [p = 2.9*10(-4), Fold change (FC) = 0.76, Variable importance of protection (VIP) = 1.75], tryptophan [p = 5.4*10(-4), FC = 0.87, VIP = 2.22], and asparagine [p = 3.6*10(-3), FC = 0.82, VIP = 1.64], were significantly lower in the three groups of CP patients than that in controls. The combination of β-amino-isobutyric acid, tryptophan, and taurine, provided high levels of diagnostic classification and risk prediction efficacy for preterm children with an area under the curve (AUC) value of 0.8741 [95% confidence interval (CI): 0.7322-1.000]. The discriminant diagnostic formula for preterm infant with CP based on the potential marker combination was defined by p = 1/(1 + e-(8.295-0.3848* BAIBA-0.1120*Trp + 0.0108*Tau)). Full-spectrum analysis of amino acid metabolomics revealed a distinct profile in CP, including reductions in the levels of β-amino-isobutyric acid, tryptophan, and taurine. Our findings shed new light on the pathogenesis and diagnosis of premature infants with CP.

Feasibility Study on Color Grading of Blue Iolite Based on GemDialogue Color Comparison Charts

To explore the feasibility of applying the GemDialogue color comparison charts to the color grading of blue iolite, the color of the charts was quantified by the integrating sphere handheld spectroscopy in this paper, and the screened data were classified into a total of 9 categories using the elbow rule and K-Means clustering analysis. Using Fisher’s discriminant to perform discriminant analysis on the 9 categories that have been classified, the discriminant function equation was established separately to verify the accuracy of this classification. Finally, the color parameters of iolite samples were substituted into the discriminant formula to obtain the color grade. By combining the classification results and visual observation, it is clear that applying the GemDialogue color charts to blue iolite color grading is feasible.

TT@MHA: A machine learning-based webpage tool for discriminating thalassemia trait from microcytic hypochromic anemia patients

BackgroundIron deficiency anemia (IDA) and thalassemia trait (TT) are the most common causes of microcytic hypochromic anemia (MHA) and are endemic in lower resource settings and rural areas with poor medical infrastructure. Accurate discrimination between IDA and TT is an essential issue for MHA patients. Although various discriminant formulas have been reported, distinguishing between IDA and TT is still a challenging problem due to the diversity of anemic populations. MethodsWe retrospectively collected laboratory data from 798 MHA patients. High proportions of α-TT (43.33 %) and TT concomitant with IDA (TT&IDA) patients (14.04 %) were found among TT patients. Five machine learning (ML) approaches, including Liner SVC (L-SVC), support vector machine learning (SVM), Extreme gradient boosting (XGB), Logistic Regression (LR), and Random Forest (RF), were applied to develop a discriminant model. Performance was assessed and compared with six existing discriminant formulas. ResultsThe RF model was chosen as the discriminant algorithm, namely TT@MHA. TT@MHA was tested in an interlaboratory cohort with a sensitivity, specificity, accuracy, and AUC of 91.91 %, 91.00 %, 91.53 %, and 0.942, respectively. A webpage tool of TT@MHA (https://dxonline.deepwise.com/prediction/index.html?baseUrl=%2Fapi%2F&id=26408&topicName=undefined&from=share&platformType=wisdom) was developed to facilitate the healthcare providers in rural areas. ConclusionThe ML-based TT@MHA algorithm, with high sensitivity and specificity, could help discriminate TT patients from MHA patients, especially in populations with high proportions of α-TT patients and TT&IDA patients. Moreover, a user-friendly webpage tool for TT@MHA could facilitate healthcare providers in rural areas where advanced technologies are not accessible.

ON DISCRIMINANTS OF MINIMAL POLYNOMIALS OF THE RAMANUJAN CLASS INVARIANTS

AbstractWe study the discriminants of the minimal polynomials $\mathcal {P}_n$ of the Ramanujan $t_n$ class invariants, which are defined for positive $n\equiv 11\pmod {24}$ . We show that $\Delta (\mathcal {P}_n)$ divides $\Delta (H_n)$ , where $H_n$ is the ring class polynomial, with quotient a perfect square and determine the sign of $\Delta (\mathcal {P}_n)$ based on the ideal class group structure of the order of discriminant $-n$ . We also show that the discriminant of the number field generated by $j({(-1+\sqrt {-n})}/{2})$ , where j is the j-invariant, divides $\Delta (\mathcal {P}_n)$ . Moreover, using Ye’s computation of $\log|\Delta(H_n)|$ [‘Revisiting the Gross–Zagier discriminant formula’, Math. Nachr. 293 (2020), 1801–1826], we show that 3 never divides $\Delta(H_n)$ , and thus $\Delta(\mathcal{P}_n)$ , for all squarefree $n\equiv11\pmod{24}$ .

Theoretical analysis and experiment of multi-modal coupled vibration of piezo-driven Π-shaped resonator

Nonlinear modal interactions have recently become the focus of intense research in mechanical resonators for their use to improve oscillator performance and probe the frontiers of fundamental physics. This paper reports for the first time a piezoelectric driven Π-shaped beam with 1:1:2 internal resonance and systematically studies the multi-mode coupling dynamic behavior. Typically, the influence mechanism of driving voltage on the energy transfer path of the multi-modal vibration is experimentally observed. With the increase of the driving voltage, number of frequency intervals of modal coupled vibration increases from 1 to 3, and then decreases to 2, which is unique to multi-mode coupled resonators. To explain the various complex nonlinear phenomena observed experimentally, a theoretical framework for multi-modal coupled vibration analysis of Π-shaped resonator is proposed for the first time. Perturbation and bifurcation analysis are introduced to deduce the discriminant formula of multi-modal coupled vibration theoretically. Both experimental measurements and theoretical predictions show that the multi-modal coupling greatly complicates the dynamic behavior of the resonant system and induces multiple amplitude jumps. In particular, based on the multi-modal coupled vibration behavior of the Π-shaped resonator, a conceptual model of trigger resonance sensor with multiple mass warnings is creatively proposed. The experimental results show that the amplitude of the resonant system has six distinct changes with the increase of the added mass, accompanied by bifurcation phenomenon. The research results of this paper provide a systematic framework for the development of multi-mode coupled resonant devices.

New logarithm-based discrimination formula for differentiating thalassemia trait from iron deficiency anemia in pregnancy

BackgroundThalassemia trait (TT) and iron deficiency anemia (IDA) are the most common conditions of microcytic hypochromic anemia (MHA) in pregnant women. Accurate discrimination between TT and IDA is an important issue, and better methods are urgently needed. Although considerable RBC formulas and indices have been developed since 1973, distinguishing between IDA and TT is still a challenging problem due to the diversity of various anemic populations. To address this problem, we assessed the diagnostic function of 43 different differential formulas in patients with microcytic anemia by using accuracy measures and recommending a new log-based differential formula.MethodsThe data of 430 pregnant women (229 with TT and 201 with IDA) were enrolled, and 44 formula performances were evaluated with receiver operating characteristic (ROC) analysis.ResultsThe newly introduced logarithm-based formula XS-1 performs better than the general discriminant index with sensitivity and specificity of 82.10 and 89.05, which are better than other formulas. In the pregnant population, the Shine and Lal and Roth..SVM. formulas have shown excellent performance, while other formulas showed poorer discriminative abilities in our study than in the original authors.ConclusionThe logarithm-based formula XS-1 can be used to screen thalassemia and iron deficiency anemia during the first trimester. Considering the particularity of pregnancy, medical personnel in different regions should choose a screening formula similar to that of the local region and population when identifying thalassemia in pregnancy. Any formula should be independently verified locally before use. For the convenience of the health care team and experimental scientists, a web-based tool has been established at http://yyy.yiyiy.top/XS-1/ by which users can easily get their desired screening test result without going through the underlying mathematical and computational details.

Разработка морфометрической формулы для полевого определения пола птенцов степного орла (Aquila nipalensis) в Алтае-Саянском регионе

Rapid sex determination of Steppe Eagle (Aquila nipalensis) nestlings without laboratory diagnostics is necessary for a variety of tasks. When working directly on a nest, it is important to know the sex of nestlings during population monitoring, ringing and tagging with GPS transmitters. Sex determination is also necessary when working with sick and injured birds, in rehabilitation centers, which do not always have the opportunity and time for genetic analysis. Experienced ornithologists in most cases can quite accurately determine the sex of nestling by eye, but this does not always work, and not all researchers have sufficient experience. The Steppe Eagle has a noticeable sexual dimorphism in size, which is well manifested even in 45-day-old nestlings. However, the size ranges of females and males overlap greatly, so one cannot reliably determine sex simply by measuring any one part of the bird's body. We have developed morphometric discriminant formulas that allow us to determine with high accuracy the sex of a Steppe Eagle nestlings in Altai-Sayan region, using the size of the tarsus, claws, beak, and tail feathers. The formulas were obtained based on measurements of (n=52) 55–65-dayold nestlings (25 males and 27 females) born in 2019. The nestling sex was determined genetically by amplification of the CHD1 gene intron, which has different length in Z and W sex chromosomes of most bird species. We analyzed relationship between various morphometric characteristics of the nestling and its sex and obtained formulas that correctly determine the sex of 51 out of 52 nestlings in the initial sample and 32 out of 33 nestlings in the test sample (born in 2021). Our discriminant formulas use both direct measurement values and ratios of different measurements to each other. In order to obtain the best formula, we altered the set of variables used and eventually chose several formulas that show the best results. These formulas can be used simultaneously to improve the accuracy of the determination. Despite the fact that the size of the tarsus, claws and beak in 55–65 day old nestlings is already quite stable, and the length of the feathers changes quickly, the formula obtained using the length of the tail gave better results than without using it. Statistical analysis showed that females and males of the Steppe Eagle have the most significant differences in tarsus diameter: it is, on average, larger in females. Differences are already noticeable in 45-day-old nestlings, whose paws almost reach the size of those of an adult bird. Moreover, the longitudinal and transverse tarsus diameters weakly correlate with each other and even more weakly with the sizes of beak, claws, and feathers, but they correlate with sex more than other measurements. This is what makes it possible to determine the sex of nestlings in the nest with a fairly high accuracy. However, analysis of nestlings born in 2022, when the depression of pika population led to a severe shortage of food for the Steppe Eagles, shows that with severe underfeeding and a lack of subcutaneous fat, female tarsus turn out to be abnormally thin, and the formula often incorrectly identifies such nestlings as males. Therefore, we developed a separate formula for determining the sex of nestlings with obvious lack of mass, which in turn less accurately determines the sex of normal nestlings. Thus, when using morphometry to determine sex, it is necessary to take into account the body condition of the nestling. The study was supported by the Basic Research Program FWGZ-2021-0014.

Predictions and Evolution Characteristics of Failure Modes of Degenerate RC Piers

During the service process, piers are often in harsh chloride ion erosion environments. The failure mode evolution of reinforced concrete (RC) piers may occur under the action of continuous corrosion. Accurately identifying the failure mode types and evolution characteristics of corroded RC bridge piers is a prerequisite for the lifetime seismic performance evaluations of bridges. First, based on Fisher’s theory and 174 RC pier columns as the analysis samples, a two-stage discrimination formula for the pier failure modes was established and compared with the existing theoretical discrimination methods. Then, based on Fisher’s discriminant grouping, and combined with Bayes’ formula and chloride erosion theory, a failure mode discrimination method for corrosion-damaged bridge piers that considers probability was developed. Finally, taking a medium-span concrete bridge as an example, the failure modes of the corroded pier in different service periods were predicted, and the influences of the various parameters on the failure mode evolution process of the corroded pier were studied. The results show that the accuracy of the proposed discriminant model was significantly improved compared with those of previous theoretical studies. The development of the failure mode features depends on how the distinct RC pier material qualities degrade under the influence of chloride ions. The degradation of the stirrups and concrete accelerates the nonductile failure of RC bridge piers, while the degradation of the longitudinal reinforcements delays it.

Karbala Discriminant Formula to Differentiate Beta-Thalassemia Trait from Iron Deficiency Anemia

AbstractBackground: Hypochromic microcytic red blood cells are common findings in routine laboratory work in all age and ethnic groups. The differentiation between iron deficiency anemia and β-thalassemia trait represents a challenge in populations with limited access to costly lab investigations Aim: To create a new mathematical formula using RBC hematological parameters to discriminate between iron deficiency anemia and β-thalassemia trait applicable to Karbala population.Methods: A descriptive cross-sectional study was done at Karbala hereditary blood disease center. The sample of this study was selected from couples referred to the premarital screening centers in Karbala governorate, Iraq. All subjects were adults above 18 years old and diagnosed with β-thalassemia trait or iron deficiency anemia. New formula (Karbala) was developed using binary logistic regression (stepwise backward elimination). The new formula and 28 previously published formulas were evaluated using receiver operator curve ROC analysis.Results: 1380 subjects were included in this study. The new formula created (Karbala discriminant formula) showed superior performance in ROC curve analysis. Karbala formula has a significantly higher AUC of 0.921 (0.905 – 0.935), followed by England Fraser, MDHL, Matos Carvalho, and Hameed.Conclusion: Hematological discriminant formulas should be tailored to fit the local population of β-thalassemia trait. Karbala discriminant formula best fits our population.Keywords: Hematological discriminant formula, β- thalassemia trait, iron deficiency anemia, binary logistic regression, Karbala formula, ROC curve, AUC, Youden index, accuracy, sensitivity, specificity, cut-off value.