Rigidity Index Research Articles

In vitro comparison of low-power diode pumping solid-state laser radiation at 589 and 650 nm on red blood cells suspension viscosity, stability, and deformability.

To investigate the effect of diode-pumped solid-state laser irradiation with yellow 589nm and red 650nm wavelengths on rheological parameters in vitro. The comparative study was conducted between November 2021 and April 2022 at the at the Postgraduate Medical Physics Laboratory, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy adult volunteers. The samples were divided into 4 aliquots. The first was preserved as a control sample, while the other 3 were exposed to a diode-pumped solid-state laser, delivering the beam for 589nm and 650nm wavelengths at radiation dose 15, 22.5, 33.5J/cm2 for 20, 30 and 45 minutes, and with each laser having a 50mW output power and a 4 mm2 spot diameter. Data was analysed using SPSS (version 24). There were 6 subjects aged 18-60 years. There was no significant difference in the viscosity values between laser wavelengths (p>0.05). Compared to the laser wavelength of 650nm, irradiation with a 589nm wavelength at the same dose resulted in a significant reduction (p<0.009) in deformability. The rigidity index of red blood cell suspension was reduced the most at a radiation dose of 22.5J/cm2 for both lasers compared to the control samples. No significant variations were found in suspended erythrocyte viscosity (p>0.05). The wavelength with 589nm lasers showed more effective influence than its 650nm counterpart in improving the rheological parameters of blood viscosity and erythrocytes deformability.

Fibre morphological characteristics, chemical composition and fuel properties of paulownia COTEVISA-2 wood

AbstractThe aim of this study was to determine the elemental composition and the fibre morphological characteristics, chemical and fuel properties of wood from paulownia COTEVISA-2 clone growing on a plantation near Granada, Spain. The research was carried out on five boards representing five 5-year-old trees, taken from a height of approximately 2–3 m. Morphologically, COTEVISA-2 wood has fibres with mean length 0.923 mm, diameter 0.029 mm, lumen width 0.026 mm, and cell wall thickness 0.0015 mm. The slenderness ratio ranged between 19.27 and 64.31, the Runkel ratio between 0.060 and 0.4259, the rigidity index between 2.83 and 19.94, Mühsteph’s index between 0.1099 and 0.5082, and the flexibility coefficient between 0.701 and 0.943. Significant differences between trees were found for the values of morphological characteristics of fibres and the derived indices, apart from the solids index. Mean values of chemical properties obtained from two parallel determinations for each sample showed that the wood contains on average 48.15% cellulose, 27.48% lignin, 7.38% pentosans and substances soluble in cold water (2.38%), hot water (3.87%), ethanol (5.51%) and 1% NaOH (19.64%). The elemental composition of paulownia COTEVISA-2 wood is as follows: C – 49.06%, H – 6.19%, N – 0.43%, S – 0.021%, Cl – 0.05%. The wood contained 0.4% ash. The heat of combustion of paulownia COTEVISA-2 wood is 18.58 MJ/kg, and the calorific value is 17.18 MJ/kg. The results suggest that paulownia COTEVISA-2 is a promising wood for energy and paper production.

Rigidity of foot deformity in congenital clubfoot: foot stiffness index

BACKGROUND: A unified system for assessing the severity of congenital clubfoot in newborns and young children worldwide remains to be established. “Rigidity” of foot deformity refers to the degree of “resistance” of foot tissues during manual correction of elements of the deformity and is often used in subjective severity of foot deformity assessment. However, there is no objective quantitative assessment for the degree of foot rigidity. AIM: The study aimed to introduce a novel clinical sign — ”rigidity of foot deformation”, which enables objective assessment of the severity of foot deformity in congenital clubfoot. MATERIALS AND METHODS: Before applying the first plaster cast, a clinical dynamometric examination was performed on 350 feet of 229 children, followed by a mathematical calculation of the foot rigidity index. Statistical analysis was performed using the nonparametric Mann–Whitney U-test and Spearman’s rank correlation coefficient. Differences were considered significant at p 0.05. RESULTS: Significant differences were found in all clinical and dynamometric parameters between congenital clubfoot of I–II, III, and IV degrees (p ≤ 0.05). Generally, the higher the degree of deformity, the more effort required to eliminate it, the smaller angle of simultaneous correction, and the higher index of foot rigidity. The results of Spearman’s correlation analysis of clinical dynamometric examination indicators in children with congenital clubfoot of I–II degree may indicate the mobile nature of the foot deformity; III degree, a rigid version of the deformity; and IV degree, an extremely rigid degree of deformity. CONCLUSIONS: Rigidity of the foot deformity is a crucial clinical sign that characterizes the severity of the foot deformity, which has a quantitative characteristic — the rigidity index. Initial data on foot rigidity enables objective assessment of the severity of the deformity and selecting an individual approach to its elimination when applying staged plaster casts using the Ponseti method.

Risk factors of non-arteritic anterior ischaemic optic neuropathy and central retinal artery occlusion.

To investigate the difference in risk factors between non-arteritic anterior ischaemic optic neuropathy (NAION) and central retinal artery occlusion (CRAO) and develop a predictive diagnostic nomogram. The study included 37 patients with monocular NAION, 20 with monocular CRAO, and 24 with hypertension. Gender, age, and systemic diseases were recorded. Blood routine, lipids, hemorheology, carotid and brachial artery doppler ultrasound, and echocardiography were collected. The optic disc area, cup area, and cup-to-disc ratio (C/D) of the unaffected eye in the NAION and CRAO group and the right eye in the hypertension group were measured. The carotid artery intimal medial thickness (C-IMT) of the affected side of the CRAO group was thicker (P=0.039) and its flow-mediated dilation (FMD) was lower (P=0.049) than the NAION group. Compared with hypertension patients, NAION patients had higher whole blood reduced viscosity low-shear (WBRV-L) and erythrocyte aggregation index (EAI; P=0.045, 0.037), and CRAO patients had higher index of rigidity of erythrocyte (IR) and erythrocyte deformation index (EDI; P=0.004, 0.001). The optic cup and the C/D of the NAION group were smaller than the other two groups (P<0.0001). The diagnostic prediction model showed high diagnostic specificity (83.7%) and sensitivity (85.6%), which was highly related to hypertension, the C-IMT of the affected side, FMD, platelet (PLT), EAI, and C/D. CRAO patients show thicker C-IMT and worse endothelial function than NAION. NAION and CRAO may be related to abnormal hemorheology. A small cup and small C/D may be involved in NAION. The diagnostic nomogram can be used to preliminarily identify NAION and CRAO.

Study on Soil Selenium-Induced Copper Deficiency in Yudong Black Goats.

Due to the degradation of pasture and strict restrictions on grazing ranges in recent years, copper (Cu) deficiency in Yudong black goats has been occurring, mainly manifested as emaciation, anemia, loss of appetite and lack of spirit. To explore the main causes of Cu deficiency in Yudong black goats, 40 black goats (1 year old, 25.11 ± 0.52 kg) were selected for this experiment; among them, 20 Yudong black goats with Cu deficiency from the experimental pasture were used as the experimental group, and 20 healthy Yudong black goats from the control pasture were used as the control group. In the pre-experiment, the mineral contents of the soil, forage, blood, and liver of black goats in both groups were determined, and in formal experiments, blood hematological, biochemical, antioxidant, and hemorheological parameters were analyzed. An experiment on the treatment of Cu deficiency in black goats was also conducted. This study showed that selenium (Se) levels in the soil, forage, blood, and liver from the experimental group were significantly lower than those from the control group (p < 0.01). The content of sulfur (S) in the forage was considerably higher than that of the control group (p < 0.01). The contents of Cu in the blood and liver from the experimental group were significantly lower than that from the control group (p < 0.01), and the content of S was considerably higher than that from the control group (p < 0.01). The blood hematology of the experimental group was affected, as evidenced by a decrease in hemoglobin, hematocrit value, mean corpuscular volume and mean corpuscular hemoglobin. The immunity and antioxidant capacity of black goats in the experiment group were impaired to varying degrees, with significant decreases in ceruloplasmin, immunoglobulin M, immunoglobulin G, glutathione peroxidase, and superoxide dismutase, and substantial increases in malondialdehyde. In addition, the experimental group showed a decrease in blood viscosity as evidenced by the rise in high shear viscosity, low shear viscosity, erythrocyte rigidity index, erythrocyte aggregation index, and erythrocyte deformation index, and a decrease in plasma viscosity. In the treatment experiment, oral administration of copper sulfate solution was carried out on 10 black goats with Cu deficiency. All the Cu deficiency goats were cured, and the Cu content in their bodies rebounded. In summary, low Se soil caused an increase in S content in the forage, and Yudong black goats feeding on high S forage resulted in a decrease in Cu absorption, which led to a secondary Cu deficiency.

An enhanced understanding of the lateral response of large-diameter monopile: Development of a new P-y curve

The present design practices of laterally loaded monopiles tends to discretize the pile into a series of beam elements and connect each element to uncoupled non-linear springs, or P-y curves, to represent soil reactions. The prevailing design codes tend to support the use of a universal P-y curve irrespective of pile configuration, flexural rigidity, and soil rigidity index. However, accumulating evidence suggests otherwise, underscoring the imperative to revise formulas, especially for large diameter rigid monopiles. This study conducts a thorough examination of load transfer and failure mechanisms in large diameter monopiles subjected to monotonic lateral loading in clayey soil. A refined formula is proposed to estimate ultimate net soil resistance, rectifying deficiencies in prevailing design codes prone to underestimation. Findings reveal significant influence of soil rigidity index on the P-y curve of rigid monopiles. Consequently, endeavours are undertaken to develop a new P-y formulation integrating the pivotal role of soil rigidity index. The newly devised P-y curve is anticipated to propel advancements in the design of large diameter monopiles, pivotal in offshore renewable energy exploitation.

Investigation of Zinc on hemorheological parameters in a rat model of diabetes

Diabetes mellitus (DM) is a complex, chronic metabolic disorder characterized by impaired regulation of blood glucose levels. Zinc (Zn) is an essential trace elements that plays a role in various physiological processes within the body, including those related to diabetes. The current study was investigated the effect of Zn supplementation on hemorheological parameters in a rat model of DM. After induction of DM, 32 male Wistar albino rats were divided into four groups: control, Zn, DM, and Zn+DM. Whole blood viscosity (WBV) was determined by using digital cone and plate viscometer and plasma viscosity (PV) was determined by a Coulter Harkness capillary viscometer. The rats in the DM Group showed a decrease in both Zn levels and body weight, as well as an increase in glucose levels when compared to the control group. Diabetic rats supplemented with Zn displayed lower blood glucose levels and higher concentrations of Zn compared to the DM Group. The higher PV and lower hematocrit level were measured in DM Group than control group and lower PV, higher hematocrit level were measured in Zn+DM group than DM Group. The WBV was measured at four different shear rates (57.6–115.2 - 172.8–230.4 s −1). A statistically significant increase was observed in the DM group compared to the control group. Additionally, a statistically significant decrease was observed in the Zn+DM Group compared to the DM Group at a shear rate of 230.4 s−1. Erythrocyte rigidity index (Tk) and oxygen delivery index (ODI) were computed under conditions of high shear rate. The rats in the DM group exhibited a reduction in ODI and an elevation in Tk in comparison to the control group. Conversely, the diabetic rats supplemented with Zn exhibited decreased Tk and increased ODI compared to the DM Group. Zn supplementation seems to have a potential beneficial effect for protecting adverse affect of diabetes on hemorheogical parameters and for maintaining vascular health.

ROAD DAMAGE EVALUATION ON RIGID PAVEMENT WITH PAVEMENT CONDITION INDEX METHOD IN KLAKAH REJO-BENOWO ROAD, SURABAYA CITY, EAST JAVA

The research objective was to analyze the level and type of damage from every kind of damage on the Klakah Rejo Benowo road by calculating the rigid pavement condition index value and providing solutions. This study took the location of the Klakah Rejo-Benowo road section, Surabaya City—data analysis by calculating the Deduct Value, m, TDV, CDV, and PCI. The research results state it was concluded that five types of damage occurred in Jalan Klakah Rejo-Benowo, Surabaya City. The types of damage are Grooves, Patches, Alligator Cracks, Weathering and Loose Granules, and Pits. Damage caused by high rainfall conditions (&gt; 900mm/year) &amp; Daily Traffic Volume exceeds the provisions of the Binamarga. After analysis, it shows that the road pavement is in Moderate/Fair condition; field analysis results and values calculated using the PCI (Pavement Index Condition) method for damaged road conditions can provide recommendations for road repairs using the Asphalt Institute MS-17 method, namely patching and resurfacing. Based on the analysis of the road condition values obtained, the solution must be patched and re-coated so that water does not quickly seep into the road layer, which causes more severe road damage.

Microstructure development in lacustrine, fine-grained sediments traced by in situ and laboratory testing

Soil microstructure, often defined as the combination of particle arrangement and bonding, can strongly influence the stiffness and strength of sedimentary deposits. As undisturbed soil sampling is a challenging task in fine-grained soils, seismic in situ testing is becoming increasingly more important to investigate its mechanical behaviour. The aim of this article is to evaluate the influences of sediment depositional age and structure-forming processes on the degree of soil structure development in Alpine deposits. Seismic in situ and laboratory testing comprising X-ray diffraction (XRD), scanning electron microscopy (SEM), pore water chemical analysis and hydrochemical modelling were executed at three Austrian test sites, namely Lokalbahn Salzburg, Rhesi and water reservoir Raggal. Based on the comparison of in situ shear wave velocities (VS,SDMT) with bender element results (VS,BE), executed on reconstituted soil specimens, it is shown that the Pleisto–Holocene-aged deposits are characterized by a VS,BE/VS,SDMT ratio of < 1, indicating the presence of microstructure. However, the youngest sediments (< 50 years) exhibit the weakest microstructure (VS,BE/VS,SDMT ≈ 1). The increase of soil structure with sediment age is represented by the updated normalized small-strain rigidity index, K*G, which is situated at the proposed transition between structured and unstructured soils (K*G = 330), ranging between 250 and 350, at all test sites. The development of microstructure can be attributed to the precipitation of calcite (CaCO3) cements in open pores, which strengthens the interparticle bonding between detrital quartz, feldspar, clay minerals and carbonate grains, subsequently reducing the soil`s porosity with increasing sediment age.

Asymmetric changes in foot anthropometry with pregnancy may be related to onset of lower limb and low back pain.

Fifty percent of pregnant females experience pain with 20% reporting long-term pain post-partum. Pregnant females undergo changes in foot anthropometry, lower extremity alignment, and joint laxity. It is unknown if asymmetric alterations may be related to development of pain. The purpose of this study was twofold: 1) to compare asymmetric alignment in pregnant females with and without pain during pregnancy and in nulliparous controls and 2) to assess the relationship between asymmetric alignment and pain severity in all participants. Ten pregnant females in their third trimester and nine nulliparous controls participated. Bilateral asymmetry of foot length, width, arch index, arch height index, arch rigidity index, arch drop, rearfoot angle, and pelvic obliquity were determined. Joint laxity and musculoskeletal pain were also assessed. ANOVAs were utilized to compare asymmetries between pregnant females reporting pain (n = 5), those not reporting pain (n = 5), and controls. Spearman's Rho correlations were used to relate asymmetry to pain magnitude (α = 0.05). No statistical differences (p>0.05) were found between pregnant females with or without pain and controls for any of the metrics. Negative correlations were found between arch index asymmetry and low back pain (p = 0.005), foot length asymmetry and lower leg pain (p = 0.008), and pelvic obliquity and lower leg pain (p = 0.020). Positive correlations were found between foot width asymmetry and knee pain (p = 0.028), as well as arch drop asymmetry and upper leg (p = 0.024), knee (p = 0.005), and lower leg pain (p = 0.019). This study was successful in identifying potential targets for prevention and treatment of pain in pregnancy. Furthermore, because pain during pregnancy may be predictive of pain post-partum, it is important to conduct future research to determine both if interventions such as footwear or exercise can prevent or treat these asymmetries and prevent post-partum pain.

Fast Lagrangian analysis of the short-term bearing capacity of shallow foundations in clays on the basis of the cone penetration test

Based on a numerical modelling of the cone penetration test CPT as well as the vertical response of shallow foundation in saturated clays, derivation of the cone factor Nk led to propose a CPT-based method of computation of the bearing capacity. This study was carried out by launching a detailed parametric study using the software FLAC-2D (Fast Lagrangian Analyses of Continua) based on the finite difference method. The soil material was modeled as a homogeneous elastic-perfectly plastic medium obeying the Mohr-Coulomb criterion, and the effects of the soil rigidity index Ir, the cone-soil interface, and the initial depth of the penetration on the cone factor Nk were investigated leading to an analytical formulation of Nk. After a comparative study with those proposed in the literature, the cone factor Nk was used to derive the bearing capacity factor Kc of a shallow foundation. Compared to current CPT-based methods proposed in the literature, this method reasonably predicts the short-term bearing capacity of shallow foundations in saturated clayey soil.

Вариации жесткости для упорядоченных теорий

One of the important characteristics of structures is degrees of semantic and syntactic rigidity, as well as indices of rigidity, showing how much the given structure differs from semantically rigid structures, i.e., structures with one-element automorphism groups, as well as syntactically rigid structures, i.e., structures covered by definable closure of the empty set. Issues of describing the degrees and indices of rigidity represents interest both in a general context and in relation to ordering theories and their models. In the given paper, we study possibilities for semantic and syntactic rigidity for ordered theories, i.e., the rigidity with respect to automorphism group and with respect to definable closure. We describe values for indices and degrees of semantic and syntactic rigidity for well-ordered sets, for discrete, dense, and mixed orders and for countable models of $\aleph_0$-categorical weakly o-minimal theories. All possibilities for degrees of rigidity for countable linear orderings are described.

Forming a financial model of carbon regulation in the context of the decarbonization objectives for the Russian Federation

The article addresses financial issues of carbon regulation. The research purpose was to identify the features and problems of the financial model development of carbon regulation in the Russian Federation. The research objectives included substantiation of the model concept, systematization of models used in international practice, characterization and assessment of the current stage of the concerning model development in the Russian Federation. According to the research hypothesis, at the early stages of development, the financial model of carbon regulation in the Russian Federation is soft, providing rather a signal effect for business and not having a significant impact on the implementation of national objectives of decarbonization. In the study of international and Russian experience in the implementation of financial models of carbon regulation, methods of content analysis and statistical processing of relevant information were applied. The theoretical results of the research include the analyzed model concept, a refined classification of its main types and a model of its rigidity index. Systematization and evaluation of applied aspects of the problem allow us to conclude that the financial model of carbon regulation in the Russian Federation is super-soft, which has advantages for business, but actualizes such challenges as the effect of the “green paradox”, the risk of importing environmental problems from countries with stricter climate requirements and the green washing problem. It is argued that the development of the financial model of carbon regulation in the Russian Federation requires improving the system of incentive tools, tightening climate reporting standards, formalizing requirements for corporate climate strategies, as well as a differentiated approach adapted to regional business conditions. The research results will be in demand in further academic and expert work in this field. In particular, they can be used in climate strategizing, including in substantiating recommendations for the implementation of the Low-Carbon Development Strategy of the Russian Federation.

A four-week minimalist shoe walking intervention influences foot posture and balance in young adults-a randomized controlled trial.

Minimalist shoes (MS) are beneficial for foot health. The foot is a part of the posterior chain. It is suggested that interventions on the plantar foot sole also affect the upper segments of the body. This study aimed to investigate the local and remote effects along the posterior chain of four weeks of MS walking in recreationally active young adults. 28 healthy participants (15 female, 13 male; 25.3 ± 5.3 years; 70.2 ± 11.9 kg; 175.0 ± 7.8 cm) were randomly assigned to a control- or intervention group. The intervention group undertook a four-week incremental MS walking program, which included 3,000 steps/day in the first week, increasing to 5,000 steps/day for the remaining three weeks. The control group walked in their preferred shoe (no MS). We assessed the following parameters in a laboratory at baseline [M1], after the four-week intervention [M2], and after a four-week wash-out period [M3]: Foot parameters (i.e., Foot Posture Index-6, Arch Rigidity Index), static single-leg stance balance, foot-, ankle-, and posterior chain range of motion, and muscle strength of the posterior chain. We fitted multiple hierarchically built mixed models to the data. In the MS group, the Foot Posture Index (b = -3.72, t(51) = -6.05, p < .001, [-4.94, 2.51]) and balance (b = -17.96, t(49) = -2.56, p = .01, [-31.54, 4.37]) significantly improved from M1 to M2, but not all other parameters (all p >.05). The improvements remained at M3 (Foot Posture Index: b = -1.71, t(51) = -2.73, p = .009, [-4,94,0.48]; balance: b = -15.97, t(49) = -2.25, p = .03, [-29.72, 2.21]). Walking in MS for four weeks might be advantageous for foot health of recreationally active young adults but no chronic remote effects should be expected.

Вариации жесткости

One of the main derived objects of a given structure is its automorphism group, which shows how freely elements of the structure can be related to each other by automorphisms. Two extremes are observed here: the automorphism group can be transitive and allow any two elements to be connected to each other, or can be one-element, when no two different elements are connected by automorphisms, i.e., the structure is rigid. The rigidity given by a one-element group of automorphisms is called semantic. It is of interest to study and describe structures that do not differ much from semantically rigid structures, i.e., become semantically rigid after selecting some finite set of elements in the form of constants. Another, syntactic form of rigidity is based on the possibility of getting all elements of the structure into a definable closure of the empty set. It is also of interest here to describe “almost” syntactically rigid structures, i.e., structures covered by the definable closure of some finite set. The paper explores the possibilities of semantic and syntactic rigidity. The concepts of the degrees of semantic and syntactic rigidity are defined, both with respect to existence and with respect to the universality of finite sets of elements of a given cardinality. The notion of a rigidity index is defined, which shows an upper bound for the cardinalities of algebraic types, and its possible values are described. Rigidity variations and their degrees are studied both in the general case, for special languages, including the one-place predicate signature, and for some natural operations with structures, including disjunctive unions and compositions of structures. The possible values of the degrees for a number of natural examples are shown, as well as the dynamics of the degrees when taking the considered operations.

Evaluating hydraulic parameters in clays based on in situ tests

Abstract The permeability of soil is an important factor controlling the flow of water through the subsoil. The article presents the results of studies of hydraulic parameters for overconsolidated clays using in situ tests. Using the excess pore pressure normalization technique, both in the case of monotonic and dilatory dissipation tests, and the time at which 50% dissipation of excess pore water pressure takes place, as well as taking into account the rigidity index of the analyzed soil, it was possible to estimate the permeability and consolidation coefficients for the analyzed clays. Based on these studies, simple relationships between the permeability coefficient and the soil behavior-type index are proposed. Proposed formulas may be applied for overconsolidated cohesive soils with soil behavior-type index values within the range of 2.05–3.30 and described in Robertson’s chart as overconsolidated silty clays, clays and heavily overconsolidated and cemented fine-grained soils. Although our proposal of determining flow parameters has been calibrated only for two analyzed cases, its utility for wider use in other overconsolidated fine-grained soils may also be taken into account.

Establishing the link between motivational disturbances and behavioural rigidity in frontotemporal dementia.

Rigid and inflexible behaviours are common in frontotemporal dementia (FTD), manifesting in compulsive pursuit of specific interests, routines, and rituals. Paradoxically, these changes occur alongside profound motivational disturbances including apathy and anhedonia. While posited to be related, no study to date has explored the link between motivational changes and behavioural rigidity in FTD. Carer ratings for 71 FTD participants (26 semantic dementia [SD], 45 behavioural variant [bvFTD]) were obtained on the Dimensional Apathy Scale (apathy), the Snaith-Hamilton Pleasure Scale (hedonic tone) and the Cambridge Behavioural Inventory-Revised (CBI-R; behavioural changes). A rigidity index was created from existing items on the CBI-R. Whole-brain voxel-based morphometry was used to explore associations between rigidity and grey matter intensity in the combined FTD group. Behavioural rigidity was significantly related to apathy severity (r = 0.57) and decreased hedonic tone (r = -0.36) in the combined FTD group. Multiple linear regression revealed a significant diagnosis × hedonic tone interaction (β = -1.40), whereby lower hedonic tone predicted rigidity in SD (r = -0.65) but not in bvFTD (r = -0.18). In contrast, the relationship between rigidity and apathy did not differ between the groups (β = -0.42). At the neural level, rigidity correlated with degeneration of predominantly right-sided frontostriatal structures including, notably, the nucleus accumbens. As the first study to demonstrate a link between motivational changes and behavioural rigidity in FTD, our findings have important clinical implications. By identifying candidate mechanisms of behavioural rigidity, our findings can inform targeted interventions to manage inflexible patterns of thought and behaviour in daily life.

The Use of CPTU and DMT Methods to Determine Soil Deformation Moduli—Perspectives and Limitations

Abstract The article presents the concept of determining constrained modulus—M0 , initial shear modulus—G0 , Young modulus—E, and rigidity index—IR on the basis of parameters from static penetration tests CPTU (Piezocone Penetration Testing), SCPTU (Seismic Piezocone Penetration Testing) and dilatometer tests DMT (Flat Dilatometer Test), SDMT (Seismic Flat Dilatometer Test). The basis for constructing the empirical relationships between the mentioned modules and parameters from the CPTU and DMT studies was to determine the factors that affect these relationships. The article discusses the impact of the following factors; geological and geotechnical conditions, conditions of recording measurements in CPTU and DMT tests, factors relating to the CPTU and DMT testing methods, factors affecting reference parameters from laboratory tests, factors related to subsoil properties. The basis for obtaining the empirical relationships for determining the analyzed modules and rigidity index were extensive research of the soils of various origins, in Poland. Measurement uncertainties and factors influencing the recorded parameters in the CPTU study were documented by the studies of the Norwegian Geotechnical Institute and the former Department of Geotechnics of the Agricultural University in Poznań. In these studies, penetrometers from several reputable manufacturers were used. The article summarizes the established empirical relationships for individual modules, taking into account the effect of overconsolidation. It also comments on the interrelationship between constrained modulus M0 from CPTU and DMT test for soils in Poland.

Predictive Value of Dynamic Corneal Response Parameters Evaluated with Scheimpflug High-Speed Video (Corvis ST) on the Visual Field Progression in Prostaglandin Treated Ocular Hypertension and Open-Angle Glaucoma Patients.

The aim of this work is to compare the Corvis ST stress-strain index (SSI) and highest concavity (HC) parameters at baseline and 1month after initiating monotherapy with prostaglandin analogues (PGs) in eyes showing visual field (VF) progression or stability. In this prospective, single-center, observational study, newly diagnosed and treatment-naïve OAG patients were examined at baseline and 1month after beginning monotherapy with topical PGs monotherapy. Goldmann applanation tonometry pressure readings, Corneal Hysteresis (ORA-CH), and the Corvis ST measurements were obtained at both visits. VF progression (Humphrey) was evaluated based on data from 6 years of follow-up after the baseline visit. Stress-strain index (SSI) and HC parameters in progressing (P) and non-progressing (NP) eyes were the main outcome measures. Sixty-three eyes were analyzed; mean age was 64.63 ± 11.26years; 47 eyes were NP and 16 eyes were P according to the event analysis performed by the Humphrey device. There were no significant differences in IOP, CCT, or Corvis parameters between NP and P groups at baseline. Nevertheless, at 1 month, the SSI index was 1.60 ± 0.34 vs. 1.80 ± 0.34 (p = 0.003) in NP vs. P eyes, respectively. HC parameters were different between the groups at 1 month (p < 0.05) suggesting an increased scleral rigidity in the P group. There was no significant difference in IOP between groups at 1 month. The Corvis ST provides a corneal rigidity index (SSI) that seems to be related to VF progression when measured 1 month after initiating PGs monotherapy. Differences in HC parameters, indicative of increased scleral stiffness, are also evident at 1 month on latanoprost in the P eyes.

Rural household income mobility in Ethiopia: Dimensions, drivers and policy.

Welfare dynamics studies are useful in understanding how individuals, families, society, and a country are organised. For the last two decades, Ethiopia's economic reports on income disparity, poverty, and other welfare metrics have been hopeful and controversial. It is crucial to understand how rural households of various income levels perform over time and income mobility. Income mobility can be observed as a change in position over time between two income vectors, with some climbing and others sliding down and changing places at various rates. This study, therefore, explored the rural households' income mobility in Ethiopia using three waves of the Living Standards Measurement Study-Integrated Survey on Agriculture (LSMS-ISA) collected from 2011 to 2016. The Shorrocks rigidity index, transition probability matrix, Fields, and Ok methods were employed to analyse the relative and absolute income mobility. The logit model with conditional fixed effect was used to assess the drivers of individual households' income mobility and the multinomial logit model with conditional fixed effect as an alternative model. Based on the finding of this study, it is suggested to implement different policies targeting income growth to shorten mobility gaps and address factors contributing to downward income mobility in rural households in Ethiopia are necessary.