Density Relationship Research Articles

Alleys: The future of walkability in suburbs

Alleys have the potential to become the future of walkability in suburban areas. This study strongly advocates for the incorporation of alleyways as fundamental components of circulation systems when designing walkable suburban neighborhoods. For this purpose, a dataset comprising 30 neighborhood samples have been meticulously selected from the cities of Abu Dhabi and Dubai. The Edge Betweenness centrality measure is used to assess how the inclusion of alleys affects the estimated trips along the network segments. This is achieved by comparing the analysis values for two network scenarios: one before and one after the inclusion of alleys. The objective of this analysis is to ascertain the circumstances under which alleys are considered as either a complementary or compensatory system to streets. The results reveal that the principal determinant of alleys' capacity to complement or compensate for street networks depends on their relative density in relation to streets. Moreover, other attributes of alleys, such as their continuity, distribution within the network, and direction, have been demonstrated to influence their utilization as central links in the network. The valuable insights derived from this analysis are instrumental in informing urban policies and design practices, contributing to the creation of more walkable areas in suburban areas.

Spatiotemporal Evolution and Rank–Size Pattern of Chinese Urban Settlements

Accurate and timely urban boundaries can effectively quantify the spatial characteristics of urban evolution and are essential for understanding the impacts of urbanization processes and land-use changes on the environment and biodiversity. Currently, there is a lack of long time-series, high-resolution, nationally consistent Chinese urban boundary data for urban research. In this study, the city clustering algorithm was used to generate urban settlement boundaries in China based on the local density, size, and spatial relationships of impervious surfaces. The results showed that both the area and the number of urban settlements in China revealed an upward trend from 1985 to 2020, with East China (EC) being much higher than other regions and South China showing the most significant growth rate. The average area ratio of urban green space in China was 41.68%, with the average area ratio in EC being higher than in other regions. Meanwhile, Zipf’s law was used to verify the universality of urban settlement rank–size; the changes in the Zipf index from 1985 to 2020 also revealed that China’s urban size tended to be concentrated, and the development of large urban settlements was relatively prominent. The urban definition method we propose in this study can divide urban boundaries efficiently and accurately, identify urban expansion hotspots, and promote research on farmland loss and ecological land degradation, further exploring the impacts of urbanization on food security, biodiversity, and carbon sequestration. By coupling big data such as economy, energy, and population with urban evolution patterns, urban managers can analyze current and future problems in urban development, thereby providing scientific decision-making for urban sustainability.

The impact of the WHIM on the IGM thermal state determined from the low-z Lyman α forest

ABSTRACT At z ≲ 1, shock heating caused by large-scale velocity flows and possibly violent feedback from galaxy formation, converts a significant fraction of the cool gas (T ∼ 104 K) in the intergalactic medium (IGM) into warm–hot phase (WHIM) with T > 105 K, resulting in a significant deviation from the previously tight power-law IGM temperature–density relationship, $T=T_0 (\rho / {\bar{\rho }})^{\gamma -1}$. This study explores the impact of the WHIM on measurements of the low-z IGM thermal state, [T0, γ], based on the b–$N_{{\rm H\,{\small I}}} $ distribution of the Ly α forest. Exploiting a machine learning-enabled simulation-based inference method trained on Nyx hydrodynamical simulations, we demonstrate that [T0, γ] can still be reliably measured from the b–$N_{{\rm H\,{\small I}}} $ distribution at z = 0.1, notwithstanding the substantial WHIM in the IGM. To investigate the effects of different feedback, we apply this inference methodology to mock spectra derived from the IllustrisTNG and Illustris simulations at z = 0.1. The results suggest that the underlying [T0, γ] of both simulations can be recovered with biases as low as |Δlog (T0/K)| ≲ 0.05 dex, |Δγ| ≲ 0.1, smaller than the precision of a typical measurement. Given the large differences in the volume-weighted WHIM fractions between the three simulations (Illustris 38 per cent, IllustrisTNG 10 per cent, and Nyx 4 per cent), we conclude that the b–$N_{{\rm H\,{\small I}}} $ distribution is not sensitive to the WHIM under realistic conditions. Finally, we investigate the physical properties of the detectable Ly α absorbers, and discover that although their T and Δ distributions remain mostly unaffected by feedback, they are correlated with the photoionization rate used in the simulation.

Deriving Vp velocity and density properties of complex litho-structural units from the analysis of geophysical log data: A study from the Southern Apennines of Italy

This study is aimed to define a velocity and density database for the main litho-structural units of the Val d’Agri area of the Southern Apennines (Italy). Here we analyze fifteen digital borehole data comprising sonic log, check shot and density log data with dedicated graphic and statistical tools. We compare velocities acquired with two techniques: check-shots and sonic logging, discussing factors influencing them and their variations with a depth trend. In general, we observe that the comparison between the check shots and the sonic logs velocities gives consistent results. The detailed analysis of well logs and velocity distribution histograms, allow us to distinguish the following eight litho-structural units and their representative velocities and densities: Liguride tertiary flysches; Apennine Carbonate Platform, Lagonegro - Clastics, Lagonegro -Carbonates; Irpinia 1; Irpinia 2 and 3; Volturino foredeep turbidites; Apulian Carbonate Platform. The density values were calculated through the velocity density relationship using the Gardner equation, and subsequently compared with the measured density values. The comparison shows good correlations with the adopted Gardner coefficient of a = 0.30 and an exponent m = 0.25 for carbonatic succession, while a Gardner coefficient of a = 0.25 and an exponent m = 0.28 for clastic lithologies.The obtained results represent a key input for the future velocity and gravity modellings and for the time to-depth conversion of seismic reflection profiles, describing the vertical and lateral lithological heterogeneities between carbonate platforms, deep-sea basinal units and clastic/turbidite successions in the complex tectonic settings of the Southern Apennines.The approach applied in this work, based on a shared analytical and graphical analysis of borehole data, can be readily extended to other case studies worldwide, being the analyzed formations lithologically comparable to many other fold-and-thrust belt rocks.

The Onset of Recrystallization in Polar Firn

AbstractConstraining the onset of dynamic recrystallization (DRX) and its effects on the mechanical properties of firn is crucial for firn densification modeling. To that end, samples from a depth of 13 m in a Summit, Greenland (72°35′N, 38°25′W) firn core were subjected to creep tests at −14°C and 0.21 MPa compressive stress to strains of 7%, 12%, 18%, and 29%. Microstructural analyses using thin‐section imaging and microcomputed x‐ray tomography (micro‐CT) revealed smaller grain sizes, reduced specific surface area and connectivity, and increased density in relation to reduced porosity as the strain increases. These results show that DRX occurs in firn under creep, with strain‐induced boundary migration (SIBM) and nucleation and growth starting at ∼7%. DRX leads to elongated grains, reduced grain size, and the development of a preferred crystallographic orientation, indicating that DRX occurs by both SIBM and nucleation and growth.

Variations in thermospheric density during two consecutive geomagnetic storms of different solar wind conditions in November 2022

Geomagnetic storms can cause severe space weather impacts on space technology, such as anomaly and loss of satellites and spacecraft. We investigate solar wind conditions in responsible for two consecutive geomagnetic storms driven by different sources: a high-speed solar wind stream (HSS) on November 3-4, 2022, and a coronal mass ejection (CME) associated with an M5.2 solar flare on November 7, 2022. Spatial and temporal variations in thermospheric density and auroral activity are studied for the two geomagnetic storms. Measurements from the Swarm satellite show that the HSS-driven geomagnetic storm enhanced the thermospheric density by ~69.4% at 462 km and by ~92.8% at 511 km, and the CME-driven geomagnetic storm enhanced it by ~99.4% at 462 km and by ~145% at 511 km. Images taken by the F17 DMSP/SSUSI indicate the auroral emission produced by CME-driven geomagnetic storm is significantly stronger than that produced by HSS-driven storm, while the HSS-driven auroras last longer than the CME-driven ones. The correlation between the hourly moving averaged SymH data and the thermospheric density is stronger for Swarm-A than for Swarm-B. The response times of the thermospheric density for the HSS-driven geomagnetic storm are zero at 462 km and ~47 minutes at 511 km, while for the CME-driven geomagnetic storm are ~28 minutes and ~35 minutes, respectively. This study sheds light on the mechanisms underlying the change in the thermospheric density in relation to different geomagnetic activities.

Evaluating temporal bone column density for optimized bone conduction implant placement

IntroductionAn optimal placement of bone conduction implants can provide more efficient mechanical transmission to the cochlea if placed in regions with greater bone column density. The aim of this study was to test this hypothesis and to determine the clinical potential of preoperative bone column density assessment for optimal implant placement.MethodsFive complete cadaver heads were scanned with quantitative computed tomography imaging to create topographic maps of bone density based on the column density index (CODI). Laser Doppler vibrometry was used to measure cochlear promontory acceleration under bone conduction stimulation in different locations on the temporal bone, using a bone-anchored hearing aid transducer at frequencies ranging from 355 Hz to 10 kHz.ResultsWe found a statistically significant association between CODI levels and the accelerance of the cochlear promontory throughout the frequency spectrum, with an average increase of 0.6 dB per unit of CODI. The distance between the transducer and the cochlear promontory had no statistically significant effect on the overall spectrum.DiscussionWe highlight the importance of bone column density in relation to the mechanical transmission efficiency of bone conduction implants. It may be worthwhile to consider column density in preoperative planning in clinical practice.

Relationships between combined and individual field crops’ biomass and planting density

ContextField crops, irrigated and rain-fed, constitute the majority of cropland worldwide. An important agricultural variable determining their biomass production is planting density. ObjectiveThe objective of the study was to explore the relationships between the biomass (dry matter) and planting density for either major individual field crops or all field crops, combined, and to suggest empirical models describing them. MethodsThis article describes a meta-analysis of the literature data on biomass per unit area or plant versus planting density for 8 major field crops: 4 cereals (corn, wheat, sorghum, and pearl millet) and 4 forbs (soybean, sunflower, rapeseed, and buckwheat). ResultsWhen data from all 8 field crops are combined, it seems that areal biomass production is practically independent of planting density, apparently obeying the constant final yield hypothesis. By contrast, analyzing each of the 8 crops separately, there is a clear rising trend of areal biomass with increasing planting density, with a mean intraspecific allometric exponent of about 0.25, and individual exponents that increase systematically with a decrease in the average planting density. ConclusionsApplying a planting density-dependent allometric exponent improves the predictability of the interspecific biomass–planting density relationship for field crops. A bounding, exponential model that describes the biomass–planting density relationship in the agricultural range of 1–1000 plants per m2 better than power-law allometric equations is proposed. Although the biological meaning of a derived generic expression relating areal biomass to single-plant biomass for field crops is not clear, the deviation of the outliers probably reflects already utilized or remaining breeding potential for increased areal biomass and agricultural yields. ImplicationsA good understanding, quantification, and prediction of the biomass–planting density relationship is essential for both plant breeding and management of crop production. Plant breeders need this knowledge to choose between strategies for either increasing the single-plant biomass or increasing the plants’ tolerance to high planting density. Agronomists and extensionists need it to optimize planting density for a particular variety under given environmental and agricultural (GxExM) conditions.

White matter microstructure is differently associated with executive functioning in youth born with congenital heart disease and youth born preterm.

Executive function deficits and adverse psychological outcomes are common in youth with congenital heart disease (CHD) or born preterm. Association white matter bundles play a critical role in higher order cognitive and emotional functions and alterations to their microstructural organization may result in adverse neuropsychological functioning. This study aimed to examine the relationship of myelination and axon density and orientation alterations within association bundles with executive functioning, psychosocial well-being, and resilience in youth with CHD or born preterm. Youth aged 16 to 26 years born with complex CHD or preterm at ≤33 weeks of gestational age and healthy controls completed a brain MRI and self-report assessments of executive functioning, psychosocial well-being, and resilience. Multicomponent driven equilibrium single-pulse observation of T1 and T2 and neurite orientation dispersion and density imaging were used to calculate average myelin water fraction (MWF), neurite density index (NDI), and orientation dispersion index values for eight bilateral association bundles. The relationships of bundle-average metrics with neuropsychological outcomes were explored with linear regression and mediation analyses. In the CHD group, lower MWF in several bundles was associated with poorer working memory and behavioral self-monitoring and mediated self-monitoring deficits relative to controls. In the preterm group, lower NDI in several bundles was associated with poorer emotional control and lower MWF in the left superior longitudinal fasciculus III mediated planning/organizing deficits relative to controls. No significant relationships were observed for psychosocial well-being or resilience. The findings of this study suggest that microstructural alterations to association bundles, including lower myelination and axon density, have different relationships with executive functioning in youth with CHD and youth born preterm. Future studies should aim to characterize other neurobiological, social, and environmental influences that may interact with white matter microstructure and neuropsychological functioning in these at-risk individuals.

A conjugated bond-based peridynamic model for laminated composite materials

The bond-based peridynamic (BB-PD) theory is inadequate in describing the four independent engineering material constants of composite lamina, which results in fixed values its Poisson's ratios and shear moduli. This study presents a novel lamina conjugated BB-PD model encompasses not only the fiber bond and matrix bond, but also the transverse bond and conjugated bond pair. By defining these four basic PD bonds, the improved conjugated BB-PD model can overcome the restriction of material properties. The determination of the four basic PD micro-modulus parameters is achieved through the utilization of the equivalent relationship of strain energy density. In addition, the lamina conjugated BB-PD model is extended to deal with composite laminates with different stacking sequences. The present study validates the accuracy and applicability of the conjugated BB-PD model for composite materials by conducting simulations of the elastic deformation and progressive damage behavior of unidirectional laminae and laminates. Moreover, the proposed model provides an elucidation of the damage modes and failure mechanisms of laminated composite materials subjected to uniaxial loading.

Association of osteoporosis with ankle fractures in the geriatric population

Ankle fractures are common in older people. However, their association with osteoporosis remains controversial. This systematic review aims to determine the relationship between ankle fracture and bone mineral density (BMD). The article presents an overview of articles that have statistical data on the relationship of bone mineral density with the frequency of ankle fractures in the elderly. The aim of the review is to define ankle fracture associations in the geriatric population. Search was performed in PubMed, Medline, Scopus publications for articles in which a study of elderly patients with ankle fractures was conducted with an assessment of bone mineral density, followed by statistical processing with the presentation of the results. Ankle fractures in the geriatric population are due to generalized bone loss and changes in trabecular bone microarchitectonics, fragility, and therefore should be considered osteoporotic fractures, regardless of BMD. Correlation relationships were established with female sex, overweight, type 2 diabetes mellitus, arterial hypertension, which are characterized by a decrease in the trabecular structure. The FRAX fracture algorithm underestimates the likelihood of fractures in geriatric patients who have a high BMI and comorbid physical pathology, so it is necessary to focus on independent clinical risk factors for BMD in order to optimize fracture prevention.

Spine, hip, and femoral neck bone mineral density in relation to vegetarian type and status among Taiwanese adults.

The impact of vegetarian diets on BMD is contentious. We determined the association of vegetarian type and status with the spine, hip, and femoral neck BMD Z-scores. We analyzed data from 20,110 Taiwan Biobank volunteers. BMD was measured using dual-energy X-ray absorptiometry (DXA). The vegetarian status (non-, former, and current vegetarians) and type (non-vegetarians, ovo-vegetarians, lacto-vegetarians, lacto-ovo-vegetarians, and vegans) were determined using questionnaires. The participants consisted of 12,910 women and 7200 men, with a mean age of 55.5years. Based on vegetarian status (reference: non-vegetarians), current vegetarians had significantly lower BMD Z-scores at the spine (unstandardized regression coefficient, B = - 0.195, p = 0.006), left hip (B = - 0.125, p = 0.008), and right hip (B = - 0.100, p = 0.027), respectively. Based on vegetarian status and type (reference: non-vegetarians), current vegans and non-vegans had notably lower BMD Z-scores at specific skeletal sites. For non-vegans, the BMD Z-scores were significant at the spine (B = -0.184, p = 0.010), left hip (B = - 0.124, p = 0.010), and left femoral neck (B = - 0.125, p = 0.012). For current vegans, however, the BMD Z-scores were significant only at the right hip (B = - 0.232; p = 0.028). Nonetheless, after stratifying vegetarian diet into more subgroups, current vegans exhibited a significant reduction in BMD Z-scores at the spine and right hip, with B-coefficients of - 0.326 and - 0.238, respectively. Current lacto-vegetarians also had significantly lower Z-scores (p < 0.05) at the spine (B = - 0.459), left hip (B = - 0.313), and right hip (B = - 0.214). Moreover, current lacto-ovo-vegetarians had significantly lower Z-scores at the spine (B = - 0.175) and left hip (B = - 0.115). Current vegetarians, particularly vegans, lacto-vegetarians, and lacto-ovo-vegetarians, demonstrated significantly lower BMD Z-scores at various skeletal sites compared to non-vegetarians. Sole reliance on a vegetarian diet might be detrimental to the bone.

Experimental study on the zebra crossing traffic flow characteristics of mixed bicycles and pedestrians

Slow transportation mode, consisting of walking and cycling, plays an important role in the urban traffic system. To analyze the influence of additional bicycles on the traffic efficiency of the bicycle-pedestrian mixed group on the zebra crossing, we conducted controlled experiments to study their traffic flow characteristics based on the micro-characteristics of individuals and the macro-effect of bicycle proportion in the mixed group in which bicycles and pedestrians often share the common road facility in some countries. This work constructs a 10 m-long, 3 m-wide passageway to mimic the zebra crossing area. We first extract the head trajectories of cyclists and pedestrians to quantitatively analyze the speed, density, and spatial relationship among them through the videos that record the complete process of the bicycle-pedestrian mixed experiments. Our quantitative results show that increasing the bicycle proportion leads to longer travel and passing time because of the large personal space requirements for cyclists. By analyzing the spatial relationship and recording the forward and lateral distance between the two nearest individuals, an improved theoretical formula is proposed to describe the passing time for unidirectional bicycle-pedestrian mixed flow on zebra crossing and provide traffic efficiency. The analysis indicates that a smaller personal space for cyclists can shorten the passing time effectively. These findings are the first step toward developing bicycle-pedestrian mixed flow on the zebra crossing, which contributes to providing practical implications for planning and designing bicycle and pedestrian shared infrastructures.

On cellular automata model of traffic flow with Lennard-Jones potential

ABSTRACT By introducing the Lennard-Jones potential into the interaction of vehicles, a new cellular automata model of traffic flow is proposed, in which the fixed probability of randomisation of cellular automata is replaced by the state transition probability of cell sites. The proposed model considers that the driver is affected by the interactional potential of vehicles before him/her, and the decision-making process is related to the value of the interactional potential. The model is more suitable for the driver’s random decision-making process which is based on the stochastic behaviour of traffic flow. The fundamental diagram (flow density relationship) of the proposed model is obtained, and the complex traffic phenomenon is reproduced through numerical simulation.

Modeling Volume-Speed-Density Relationship on the Cibubur Transyogi Road Based on Traffic Behavior During Peak Hours Activity

Transyogi road Cibubur is the main road connecting the activity zone in the city of Bogor. This research models the Volume - speed - density relationship model to determine traffic behavior caused by the activity system in that zone. The research methodology used is quantitative descriptive research modeled using mathematical equations. The inter-city traffic movement that occurs on this section causes the traffic flow situation to become unstable, plus the large rate of increase in traffic and the number of vehicles in the area means it is necessary to carry out planning to anticipate future traffic movement needs. A macroscopic approach can show overall traffic flow. This approach is described by 3 parameters, namely traffic flow (volume), density and speed. The Greenshield, Greenberg, and Underwood models can describe the relationship mathematically between these three parameters. The results of the research show that the flow characteristics at peak hour conditions are shown in the Underwood model with the model significance analysis value on Friday having a value of 0.940. For the model equation between Speed and Density we get S = 54.1 Exp (–D/370.15) Volume and Density get V = 54.1 D Exp (–D/370.15) Volume and Speed get V = 370.15 S Ln (54.1/S). The volume - speed - density relationship model shows that traffic in urban areas has characteristics determined by the zones built from the cover area. So, controlling traffic volume during peak hours in this zone must be controlled by adjusting the activity system on the road corridors that are traversed.

High connectivity among Vesicomyid bivalves from cold seeps and deep-sea fans of Congo

Chemosynthetic ecosystems are scattered in the deep ocean, harbouring highly specialized communities, among which the degree of connectivity and dispersal is scarcely studied. This gap is largely due to limited range distribution, either real or due to highly partial exploration, preventing the availability of a sufficient number of samples for population genetic analysis. For the few species that escaped this gap, large-scale panmixia was often reported, raising wonders as to the evolutionary mechanisms involved in the first steps of speciation. Vesicomyid bivalves are one of the most abundant groups of chemosynthetic fauna, for which depth was proposed as an essential driver of differentiation. Early stages of speciation are thus expected to involve genetic differentiation along depth gradients. The vesicomyid bivalve Christineconcha regab was studied across widely separated localities along the Western African margin, from the cold-seeps of Regab pockmarks located at 3150 m depth on the Congo margin to the turbiditic lobes of the Congo deep-sea fan located at 5000 m depth, using mitochondrial (COI) sequences and eight microsatellite loci. Despite rather high density in relation to high organic matter availability, results obtained showed rather low levels of genetic diversity at both mtDNA and microsatellites. The main consistent pattern of differentiation was observed across depths from Regab pockmark (South-Western part) and lobe areas (Lobe B and C). This is likely due to the largest sample sizes characterizing Regab_SW and Lobe C allowing the detection of faint genetic differentiation, and possibly to a stronger signature in the demographically declining (thus acknowledgedly under sampled) Lobe B. Other significant results were not congruent among markers, suggesting low statistical power due to limited sample size or the occurrence of chaotic genetic patchiness. Altogether, the results suggest the occurrence of effective gene flow at regional scale, and departure from equilibrium in the recently discovered lobes of the Congo River, possibly resulting from unstable environmental conditions and recurrent events of extinction recolonization.

Speed, Density, and Crash Relationship in Urban Arterial Roads

Vehicle speed has an essential role in the occurrence of traffic accidents. Increasing the number of vehicles operating on the road will further increase the risk of traffic accidents because it is not balanced with discipline in driving. This study's purpose is to analyze the relationship between speed and traffic accidents that occurred in Gadjah Mada and Hayam Wuruk Road, Jember, through several variations of calculations. The independent variables used are average speed and 85th percentile speed and density, while the dependent variable used is the accident rate. The analysis used is a correlation test that determines the level of closeness of the relationship between the two variables and a regression test that helps estimate the relationship between the two variables through a regression equation model that will be selected based on conditions in the field. The results of this study indicate that lower speed is associated with a lower accident rate. Meanwhile, lower vehicle density leads to an increase in the accident rate. Speed management to improve traffic safety in Indonesia is needed. Direction for future research is presented.

Resources of red fox in the Moscow region

Red fox (Vulpes vulpes L.) is one of the most common predatory mammals of the canid family living on the territory of the Moscow region. The main interest in the study of red fox is caused by the lack of data on the current state of the dynamics of the number of species on the territory of the hunting grounds of this region. The purpose of the research was to study the resources of the red fox grouping and their use on the territory of the Moscow region. It was found that the number of red fox in the Moscow region from 2010 to 2021 tended to decrease and amounted to 4014 individuals in 2021. The average long-term population density of the fox was at the level of 2,7 individuals per 1000 ectares of native land, the biological productivity of hunting grounds for the red fox in 2017–2021 was 1,15 rubles/ha, and the yield of its products in 2016–2019 was 0,82 rubles/ha with the average annual cost of resources 3867,45 thousand rubles in 2010–2021. Fox harvest in 2010–2021 was unstable and amounted to 43-73 % of the post-harvest population, which may be due to the lack of demand for fox skins. According to the results of the research the relationship of the highest fox population density per 1000 hectares of native land in the Solnechnogorsky and the Kashirsky districts with the largest landfi lls of the Moscow region operating on their territories was revealed. A map of the average annual resources of red fox and their placement in the Moscow region in 2010–2021 has been developed, which clearly shows the most promising areas of the Moscow region for the organization of hunting for red fox.

The relationship of peritubular capillary density with glomerular volume and kidney function in living kidney donors

BackgroundPeritubular capillary rarefaction plays an important role in the progression of chronic kidney disease. Little is known about the relation between peritubular capillary density, glomerular volume and filtration rate in the healthy kidney.MethodsIn this single-center study, we included 69 living kidney donors who donated between 2005 and 2008 and had representative renal biopsies available. In all donors, glomerular filtration rate was measured using 125I-Iothalamate before donation and at five years after donation. Before donation, the increase in glomerular filtration rate after dopamine stimulation was measured. Glomerular volume and peritubular capillary density were determined in biopsies taken at the time of transplantation. Pearson’s correlation coefficient and linear regression were used to assess relations between parameters.ResultsMean donor age was 52 ± 11 years and mean measured glomerular filtration rate was 119 ± 22 mL/min before donation and 82 ± 15 mL/min at five years after donation. While peritubular capillary density (measured by either number of peritubular capillaries/50,000 μm2 or number of peritubular capillaries/tubule) was not associated with measured glomerular filtration rate before or after donation, number of peritubular capillaries/tubule was associated with the increase in measured glomerular filtration rate after dopamine stimulation (St.β = 0.33, p = 0.004), and correlated positively with glomerular volume (R = 0.24, p = 0.047). Glomerular volume was associated with unstimulated measured glomerular filtration rate before donation (St.β = 0.31, p = 0.01) and at five years (St.β = 0.30, p = 0.01) after donation, independent of age.ConclusionsIn summary, peritubular capillary density was not related to unstimulated kidney function before or after kidney donation, in contrast to glomerular volume. However, number of peritubular capillaries/tubule correlated with the increase in glomerular filtration rate after dopamine stimulation in healthy kidneys, and with glomerular volume. These findings suggest that peritubular capillary density and glomerular volume differentially affect kidney function in healthy living kidney donors.Graphical abstract

Evaluation of Speed, Flow, and Density Performance under Different Severity of Speed Bumps

Speed bumps are effective traffic calming tools that give transportation experts the ability to regulate vehicle speeds and enhance safety in particular areas. Despite being often utilized in populated areas, they are more common on other, busier roads (especially in developing nations), thanks to their efficiency, low cost of implementation, and simple installation procedure. Numerous speeds, flow, and density relationship hypothesized in various studies are supported by empirical data gathered in favorable circumstances. Because the graph is not a function, those who delved into comparison study under diverse situations frequently employ forced curves to demonstrate how flow and speed are related. However, the research makes an attempt to hypothesize that the behavior of dynamic speed-flow, speed-density, and flow-density functions is identical. In the study, the link between speed and flow under different severity speed bumps. The current study’s main objective is to is to quantify traffic volume and speed according to controlled conditions before comparing them to unfavorable speed bumps conditions of varying severity: low SB1, medium SB2, and high SB3. To determine the link between the traffic characteristics, the Greenshields model is used. The study show that decrease in speed from 66.6 km/h (control section speed) to 39.4 km/h, which is equivalent to a drop in speed of about 40%. SB2’s moderate severity bumps on traffic volume, speed, and density caused the flow rate to drop to 1236 vph and the free flow speed to drop to 28.2 km/h. While SB3’s high intensity bumps had an impact on traffic characteristics, the study show that the maximum value of speed is 5.34 (km/h), which equates to an hourly traffic flow of 816 cars.