Digital soil mapping using remote sensing indices, terrain attributes, and vegetation features in the rangelands of northeastern Iran

Digital soil mapping has been introduced as a viable alternative to the traditional mapping methods due to being fast and cost-effective. The objective of the present study was to investigate the capability of the vegetation features and spectral indices as auxiliary variables in digital soil mapping models to predict soil properties. A region with an area of 1225 ha located in Bajgiran rangelands, Khorasan Razavi province, northeastern Iran, was chosen. A total of 137 sampling sites, each containing 3-5 plots with 10-m interval distance along a transect established based on randomized-systematic method, were investigated. In each plot, plant species names and numbers as well as vegetation cover percentage (VCP) were recorded, and finally one composite soil sample was taken from each transect at each site (137 soil samples in total). Terrain attributes were derived from a digital elevation model, different bands and spectral indices were obtained from the Landsat7 ETM+ images, and vegetation features were calculated in the plots, all of which were used as auxiliary variables to predict soil properties using artificial neural network, gene expression programming, and multivariate linear regression models. According to R ² RMSE and MBE values, artificial neutral network was obtained as the most accurate soil properties prediction function used in scorpan model. Vegetation features and indices were more effective than remotely sensed data and terrain attributes in predicting soil properties including calcium carbonate equivalent, clay, bulk density, total nitrogen, carbon, sand, silt, and saturated moisture capacity. It was also shown that vegetation indices including NDVI, SAVI, MSAVI, SARVI, RDVI, and DVI were more effective in estimating the majority of soil properties compared to separate bands and even some soil spectral indices.

Measurement of the mechanical properties of the human gallbladder

Gallbladder is a small organ of the body which is located in the right side of the liver. It is responsible of storing the bile and releasing it to the intestine. The gallbladder can subject to the mechanical deformation/loading as a result of the cholecystitis, cholesterolosis of the gallbladder, etc. However, so far the mechanical properties of the human gallbladder have not been measured. This study was aimed at conducting an experimental study to measure the mechanical properties of the human gallbladder under the axial and transversal tensile loadings. To do that, the gallbladder tissue of 16 male individuals was excised during the autopsy and subjected to a series of axial and transversal loadings under the strain rate of 5 mm/min. The amount of elastic modulus as well as the maximum/failure stress of the tissues were calculated via the resulted stress-strain diagrams and reported. The results revealed that the axial and transversal elastic modulus were 641.20 ± 28.12 (mean ± SD) and 255 ± 24.55 kPa, respectively. The amount of maximum stresses was also 1240 ± 99.94 and 348 ± 66.75 kPa under the axial and transversal loadings, respectively. The results revealed a significantly higher axial stiffness (p < .05, post hoc Scheffe method) compared to the transversal one. These findings have implications not only for understanding the axial and transversal mechanical properties of the human gallbladder tissue, but also for providing a diagnosis tool for the doctors to have a suitable threshold value of the healthy gallbladder tissue.

Optimizing through computational modeling to reduce dogboning of functionally graded coronary stent material

Coronary artery disease is the leading cause of death among the men and women. One of the most suitable treatments for this problem is balloon angioplasty with stenting. Functionally graded material (FGM) stents have shown suitable mechanical behavior in simulations. While their deformation was superior to uniform materials, the study was aimed at finding the most suitable configuration to reach the optimum performance. A combination of finite element method (FEM) and optimization algorithm have been used to fulfil this objective. To do that, three different conditions have been investigated in a Palmaz-Schatz geometry, where in the first and second ones the stent was a combination of steel and CoCr alloy (L605), and the third condition was a combination of CoCr alloy (L605) and CoCr alloy (F562). In the first and third conditions, dogboning was the objective function, but in the second condition a non-uniform deformation indicator was chosen as the objective function. In all three conditions the heterogeneous index was the control variable. The stent in the third condition showed a poor performance. While in the steel/CoCr alloy (L605) stents the heterogeneous index of 0.374 showed the lowest maximum dogboning, the heterogeneous index of 5 had more uniform deformation. Overall due to the lower dogboning of the steel/CoCr alloy (L605) stent with heterogeneous index of 0.374, this stent is recommended as the optimum stent in this geometrical configuration.

A comparative study on the mechanical energy of the normal, ACL, osteoarthritis, and Parkinson subjects

BACKGROUND

The influence of various musculoskeletal disorders has been evaluated using different kinetic and kinematic parameters. But the efficiency of walking can be evaluated by measuring the effort of the subject, or by other words the energy that is required to walk.

OBJECTIVE

The aim of this study was to identify mechanical energy differences between the normal and pathological groups. Four groups of 15 healthy subjects, 13 Parkinson subjects, 4 osteoarthritis subjects, and 4 ACL reconstructed subjects have participated in this study. The motions of foot, shank and thigh were recorded using a three dimensional motion analysis system. The kinetic, potential and total mechanical energy of each segment was calculated using 3D markers positions and anthropometric measurements.

RESULTS

Maximum value and sample entropy of energies was compared between the normal and abnormal subjects. Maximum value of potential energy of OA subjects was lower than the normal subjects. Furthermore, sample entropy of mechanical energy for Parkinson subjects was low in comparison to the normal subjects while sample entropy of mechanical energy for the ACL subjects was higher than that of the normal subjects.

CONCLUSION

Findings of this study suggested that the subjects with different abilities show different mechanical energy during walking.

A fully analytical approach to investigate the electro-viscous effect of the endothelial glycocalyx layer on the microvascular blood flow

BACKGROUND

Recently, the glycocalyx lining the endothelial surface has emerged as a structure of fundamental importance to a wide range of phenomena that has undeniable effect on cardiovascular health and disease. With respect to the blood flow in small vessels, it has been experimentally reported that the glycocalyx layer causes additional resistance to the flow.

METHODS

The hypothesis of glycocalyx resistance against the blood flow, considered as two-phase layer fluid through a small blood vessel, was theoretically evaluated. To do that, a very thin electric double layer (EDL) was considered and the fluid flow was modeled by the well-known Poisson and Boltzmann equations in micro-fluidics alongside the general Navier-Stokes equation. Finally, a complete analytical solution for this particular case was developed.

RESULTS

The results confirmed the previous findings indicated that the negatively charged glycocalyx layer has no effect on the macro/micro scale blood flow. Here and in the nano-scale, slightly influence was observed and reported in this study.

CONCLUSION

Moreover, more details about the thin electrically significant layer, close to the EDL, would be delineate to better recognition of electro-viscous effect caused by the endothelial glycocalyx near microvascular walls.

The effectiveness of earmuffs on the physiologic and behavioral stability in preterm infants

BACKGROUND

The use of earmuffs can protect preterm infants against negative effects of high noise levels in the neonatal intensive care unit. This study was aimed at assessing the effectiveness of the earmuffs on the physiologic and behavioral responses in preterm infants.

METHODS

A crossed over controlled trial was conducted at Aliasghar Hospital (Tehran, Iran) in 2014. Thirty-six preterm infants cared in closed incubators, 18 cases wore a pair of silicon earmuffs in the first day and the others were worn it at the second day. During 2 consecutive days, all subjects were observed as their own controls (without earmuffs). Physiologic (body temperature, heart rate, respiratory rate, systolic, diastolic pressures, arterial Oxygen Saturation) and behavioral responses (according to the Anderson behavioral state scoring system) were assessed every 2 h for 8 h long during daytime for two consecutive days.

RESULTS

The application of earmuffs could decrease the rate of the heart and respiratory while could increase the amount of oxygen saturation (p < 0.05). The results also showed that the preterm infants with earmuffs had lower ABSS score and a better light sleep compared to those without earmuffs (2.38 ± 0.47 versus 4.8 ± 0.97, p < 0.05).

CONCLUSION

The results indicated that using the earmuffs reduces the level of noise in NICUs following by improving the preterm neonates' physiological stability and behavioral states of ABSS.

Low-intensity endurance exercise plus nandrolone decanoate modulates cardiac adiponectin and its receptors

Vast adverse effects of anabolic-androgenic steroids (AASs) on athletes' cardiovascular systems have been reported. However, there is still a lack of adequate information regarding the pathways and mechanisms involved. We tested the hypothesis that adiponectin and its receptors in the heart may be affected by long-term use of AASs alongside exercising. Male Wistar rats were randomized into the control (CTL), exercise (EX), nandrolone (Nan), arachis (Arach) group which treated with arachis as vehicle, trained vehicle (EX+Arach) and trained nandrolone (EX+Nan) groups that were treated for 8 weeks. One day after the end of the protocol, animals were sacrificed and their hearts were frozen. TNF-α and adiponectin proteins of hearts were evaluated quantitatively by ELISA kits, and Western blot analysis was used for measuring adiponectin receptor protein expression. TNF-α protein increased significantly in the EX+Nan group (P<.05 vs CTL group). The AdipoR1 protein was significantly higher in the presence of nandrolone alongside exercise (P<.05 vs Nan and EX+Arach groups, P<.01 vs CTL and Arach groups). In addition, AdipoR2 protein enhanced in the EX+Nan group when compared with the other groups (P<.05 vs EX and EX+Arach groups, P<.01 vs CTL, Arach and Nan groups). Chronic nandrolone plus mild endurance exercise may be associated with imbalance in pro-/anti-inflammatory cytokines and may induce a positive modulatory effect on cardiac adiporeceptors in rat. Further studies are required before these findings can be generalized to humans.

A numerical study on the application of the functionally graded materials in the stent design

Undesirable deformation of the stent can induce a significant amount of injure not only to the blood vessel but also to the plaque. The objective of this study was to reduce/minimize these undesirable deformations by the application of Functionally Graded Materials (FGM). To do this, Finite Element (FE) method was employed to simulate the expansion of a stent and the corresponding displacement of the stenosis plaque. Three hyperelastic plaque types as well as five elastoplastic stents were simulated. Dogboning, foreshortening, maximum stress in the plaque, and the pressure which is needed to fully expand the stent for different stent materials, were acquired. While all FGMs had lower dogboning in comparison to the stents made of the uniform materials, the stent with the lowest heterogeneous index displayed the lowest amount of dogboning. Steel stent showed the lowest foreshortening and fully expansion pressure but the difference was much lower than that the one for dogboning. Therefore, the FGM with the heterogeneous index of 0.5 is expected to exhibit the most suitable results. In addition, the results revealed that the material parameters has crucial effects on the deformation of the stent and, as a result, as a design point of view the FGM parameters can be tailored to achieve the goal of the biomechanical optimization.

Dynamic finite element simulation of dental prostheses during chewing using muscle equivalent force and trajectory approaches

The long-term application of dental prostheses inside the bone has a narrow relation to its biomechanical performance. Chewing is the most complicated function of a dental implant as it implements different forces to the implant at various directions. Therefore, a suitable holistic modelling of the jaw bone, implant, food, muscles, and their forces would be deemed significant to figure out the durability as well as functionality of a dental implant while chewing. So far, two approaches have been proposed to employ the muscle forces into the Finite Element (FE) models, i.e. Muscle Equivalent Force (MEF) and trajectory. This study aimed at propounding a new three-dimensional dynamic FE model based on two muscle forces modelling approaches in order to investigate the stresses and deformations in the dental prosthesis as well as maxillary bone during the time of chewing a cornflakes bio. The results revealed that both contact and the maximum von Mises stress in the implant and bones for trajectory approach considerably exceed those of the MEF. The maximum stresses, moreover, are located around the neck of implant which should be both clinically and structurally strong enough to functionally maintain the bone-implant interface. In addition, a higher displacement due to compressive load is observed for the implant head in trajectory approach. The results suggest the benefits provided by trajectory approach since MEF approach would significantly underestimate the stresses and deformations in both the dental prosthesis and bones.

A Combination of Constitutive Damage Model and Artificial Neural Networks to Characterize the Mechanical Properties of the Healthy and Atherosclerotic Human Coronary Arteries

It has been indicated that the content and structure of the elastin and collagen of the arterial wall can subject to a significant alteration due to the atherosclerosis. Consequently, a high tissue stiffness, stress, and even damage/rupture are triggered in the arterial wall. Although many studies so far have been conducted to quantify the mechanical properties of the coronary arteries, none of them consider the role of collagen damage of the healthy and atherosclerotic human coronary arterial walls. Recently, a fiber family-based constitutive equation was proposed to capture the anisotropic mechanical response of the healthy and atherosclerotic human coronary arteries via both the histostructural and uniaxial data. In this study, experimental mechanical measurements along with histological data of the healthy and atherosclerotic arterial walls were employed to determine the constitutive damage parameters and remodeling of the collagen fibers. To do this, the preconditioned arterial tissues were excised from human cadavers within 5-h postmortem, and the mean angle of their collagen fibers was precisely determined. Thereafter, a group of quasistatic axial and circumferential loadings were applied to the arterial walls, and the constrained nonlinear minimization method was employed to identify the arterial parameters according to the axial and circumferential extension data. The remodeling of the collagen fibers during the tensile test was also predicted via Artificial Neural Networks algorithm. Regardless of loading direction, the results presented a noteworthy load-bearing capability and stiffness of the atherosclerotic arteries compared to the healthy ones (P < 0.005). Theoretical fiber angles were found to be consistent with the experimental histological data with less than 2 and 5° difference for the healthy and atherosclerotic arterial walls, respectively. The pseudoelastic damage model data were also compared with that of the experimental data, and interestingly, the arterial mechanical behavior for both the primary loading (up to the elastic region) and the discontinuous softening (up to the ultimate stress) was well addressed. The proposed model predicted well the mechanical response of the arterial tissue considering the damage of collagen fibers for both the healthy and atherosclerotic arterial walls.

Molecular analysis of the bacille Calmette-Guérin vaccine strain currently being used in Iran

BACKGROUND

In developing countries, tuberculosis (TB) infection control remains a challenge. The bacille Calmette-Guérin (BCG) vaccine is the only effective vaccine available for TB control. Iran uses a local BCG vaccine strain with an unknown substrain.

OBJECTIVE

To investigate the molecular characteristics of the current BCG strain being used in Iran using comparative genomics of the evolutionarily late strains, including BCG vaccines Pasteur, BCG-Danish, BCG-Glaxo, BCG-Prague, BCG-Frappier, BCG-Connaught and BCG-Moreau.

METHODS

A total of 67 different vials of BCG vaccine were cultured. DNA was extracted using the modified cetrimonium bromide (CTAB) method, and multiplex polymerase chain reaction (PCR) was performed to determine four target genomic regions of difference (RD) 1, RD8, RD16 and SenX3-RegX3, and to see whether RD2 and RD14 were present.

RESULTS

Our results showed that all studied batches were Mycobacterium bovis; molecular analysis revealed that the Iranian vaccine strains possess RD8, RD16 and SenX3-RegX3 regions but not RD1, RD2 and RD14. All of the vaccine batches analysed were compatible with BCG-Pasteur 1173p2, the original strain.

CONCLUSION

All of the BCG strains studied were recognised as the BCG-Pasteur 1173p2 strain. No genetic diversity among stocks and ready-for-use vaccine vials were detected.

Water-soluble, neutral 3,5-diformyl-BODIPY with extended fluorescence lifetime in a self-healable chitosan hydrogel

3,5-Diformyl-BODIPY cross-linked chitosan-based hydrogels exhibit fluorescence resonance energy transfer (FRET) dynamics, water solubility, self-healing ability and good values of BODIPY fluorescence lifetimes.

Effects of using eucalyptus (Eucalyptusglobulus L.) leaf powder and its essential oil on growth performance and immune response of broiler chickens

The aim of this study was to evaluate the effects of eucalyptus leaf powder (ELP) and eucalyptus essential oil (EEO) on growth performance and immune response of broiler chickens. A total of 160 broiler chicks were assigned randomly into five dietary treatments from 7-42 days of age. Dietary treatments included: a control diet, control diets plus 1,000 or 3,000 mg/kg of ELP, and control diets plus 250 or 500 mg/kg of EEO. Dietary inclusion of ELP decreased body weight gain (BWG) during 7-28 days of age. Broilers fed diet containing 3,000 mg/kg of ELP had lower feed intake (FI) during 7-28 days compared to the other treatments. Broilers fed ELP or EEO had greater primary antibody response to sheep red blood cells (SRBC) compared to the control, but differences in secondary antibody response were not significant. In conclusion, dietary EEO has the potential to enhance immune response of broiler chickens.

A combination of experimental and finite element analyses of needle-tissue interaction to compute the stresses and deformations during injection at different angles

One of the main clinical applications of the needles is its practical usage in the femoral vein catheterization. Annually more than two million peoples in the United States are exposed to femoral vein catheterization. How to use the input needles into the femoral vein has a key role in the sense of pain in post-injection and possible injuries, such as tissue damage and bleeding. It has been shown that there might be a correlation between the stresses and deformations due to femoral injection to the tissue and the sense of pain and, consequently, injuries caused by needles. In this study, the stresses and deformations induced by the needle to the femoral tissue were experimentally and numerically investigated in response to an input needle at four different angles, i.e., 30°, 45°, 60°, and 90°, via finite element method. In addition, a set of experimental injections at different angles were carried out to compare the numerical results with that of the experimental ones, namely pain score. The results revealed that by increasing the angle of injection up to 60°, the strain at the interaction site of the needle-tissue is increased accordingly while a significant falling is observed at the angle of 90°. In contrast, the stress due to injection was decreased at the region of needle-tissue interaction with showing the lowest one at the angle of 90°. Experimental results were also well confirmed the numerical observations since the lowest pain score was seen at the angle of 90°. The results suggest that the most effective angle of injection would be 90° due to a lower amount of stresses and deformations compared to the other angles of injection. These findings may have implications not only for understating the stresses and deformations induced during injection around the needle-tissue interaction, but also to give an outlook to the doctors to implement the most suitable angle of injection in order to reduce the pain as well as post injury of the patients.

A combination of experimental and numerical methods to investigate the role of strain rate on the mechanical properties and collagen fiber orientations of the healthy and atherosclerotic human coronary arteries

Atherosclerosis enables to alter not only the microstructural but also the physical properties of the arterial walls by plaque forming. Few studies so far have been conducted to calculate the isotropic or anisotropic mechanical properties of the healthy and atherosclerotic human coronary arteries. To date there is a paucity of knowledge on the mechanical response of the arteries under different strain rates. Therefore, the objective of the concurrent research was to comprehend whether the alteration in the strain rates of the human atherosclerotic arteries in comparison with the healthy ones contribute to the biomechanical behaviors. To do this, healthy and atherosclerotic human coronary arteries were removed from 18 individuals during autopsy. Histological analyses by both an expert histopathologist and an imaged-based recognizer software were performed to figure out the average angle of collagen fibers in the healthy and atherosclerotic arterial walls. Thereafter, the samples were subjected to 3 diverse strain rates, i.e., 5, 20, and 50 mm/min, until the material failure occurs. The stress-strain diagrams of the arterial tissues were calculated in order to capture their linear elastic and nonlinear hyperelastic mechanical properties. In addition, Artificial Neural Networks (ANNs) was employed to predict the alteration of mean angle of collagen fibers during load bearing up to failure. The findings suggest that strain rate has a significant (p < 0.05) role in the linear elastic and nonlinear hyperelastic mechanical properties as well as the mean angle of collagen fibers of the atherosclerotic arteries, whereas no specific impact on the healthy ones. Furthermore, the mean angle of collagen fibers during the load bearing up to the failure at each strain rate was well predicted by the proposed ANNs code.

Comparison of interleukin-10 and interleukin-13 in cord blood of infants born by vaginal delivery and caesarean

BACKGROUND

The present study assessed the levels of IL-13 and IL-10 in umbilical cord blood of infants born through normal vaginal delivery and infants born with cesarean section.   METHODS: This pilot study was performed on 42 neonates born at Rasool-e-Akram hospital between May 2013 and May 2014 categorized into two groups born by vaginal delivery (n = 21) and those who born by cesarean section (n = 21).

RESULTS

No difference was observed between the two groups with normal vaginal delivery and cesarean delivery in the level of IL-13 in umbilical cord blood (1.42 ± 0.23 versus 1.40 ± 0.22, respectively, p = 0.785). The mean level of IL-10 in umbilical cord blood in the group with vaginal delivery was 6.35 ± 2.54 and in another group with cesarean section was 5.69 ± 2.42 with no significant difference (p = 0.393). According to the multivariate linear regression analyses, no difference was found between the two groups of the mode of delivery in the level of IL-10 (beta = -0.454, SE = 0.802, p = 0.575) and also in the level of IL-13 (beta = 0.012, SE = 0.076, p = 0.877). None of the indicators including gestational age, mother's age, sex of neonate, number of live births, history of abortion, and number of parity could predict increased level of the interleukins in umbilical cord blood.  CONCLUSION: Mode of delivery may not be an indicator for altering cord blood levels of IL-13 and IL-10.

Computing the stresses and deformations of the human eye components due to a high explosive detonation using fluid-structure interaction model

INTRODUCTION

In spite the fact that a very small human body surface area is comprised by the eye, its wounds due to detonation have recently been dramatically amplified. Although many efforts have been devoted to measure injury of the globe, there is still a lack of knowledge on the injury mechanism due to Primary Blast Wave (PBW). The goal of this study was to determine the stresses and deformations of the human eye components, including the cornea, aqueous, iris, ciliary body, lens, vitreous, retina, sclera, optic nerve, and muscles, attributed to PBW induced by trinitrotoluene (TNT) explosion via a Lagrangian-Eulerian computational coupling model.

MATERIALS AND METHODS

Magnetic Resonance Imaging (MRI) was employed to establish a Finite Element (FE) model of the human eye according to a normal human eye. The solid components of the eye were modelled as Lagrangian mesh, while an explosive TNT, air domain, and aqueous were modelled using Arbitrary Lagrangian-Eulerian (ALE) mesh. Nonlinear dynamic FE simulations were accomplished using the explicit FE code, namely LS-DYNA. In order to simulate the blast wave generation, propagation, and interaction with the eye, the ALE formulation with Jones-Wilkins-Lee (JWL) equation defining the explosive material were employed.

RESULTS

The results revealed a peak stress of 135.70kPa brought about by detonation upsurge on the cornea at the distance of 25cm. The highest von Mises stresses were observed on the sclera (267.3kPa), whereas the lowest one was seen on the vitreous body (0.002kPa). The results also showed a relatively high resultant displacement for the macula as well as a high variation for the radius of curvature for the cornea and lens, which can result in both macular holes, optic nerve damage and, consequently, vision loss.

CONCLUSION

These results may have implications not only for understanding the value of stresses and strains in the human eye components but also giving an outlook about the process of PBW triggers damage to the eye.