Comparison of saturation models in complex hillslopes

Abstract Hillslopes of natural catchment have a complex geometry. In complex hillslopes, combining different cases of plan shape (convergent, parallel and divergent) and profile curvature (concave, convex and straight) nine different geometries are created. In prediction of the surface and subsurface runoff of catchments based on saturation excess runoff mechanism, the saturated and unsaturated zones of hillslopes must be first separated. Subsurface travel time of hillslope is dependent on saturation attributes. In this research, a new saturation model, called Gamma, was developed to predict the saturated zone length and subsurface travel time in complex hillslopes. An analytical formula was introduced to calculate saturation zone length in Gamma model. Results of Gamma model, namely the saturation zone length and subsurface travel time, were compared with the results given by two other complex saturation models W and Sigma. The results of the three models were relatively close to each other in convergent and parallel hillslopes of different profile curvature type. However, due to the existence of an analytical equation for estimation of saturated zone length in the Gamma model, this model is recommended. It should be noted that for straight divergent and convex divergent hillslopes, the Gamma model is not suitable and Sigma or W model should be used.Abstract Hillslopes of natural catchment have a complex geometry. In complex hillslopes, combining different cases of plan shape (convergent, parallel and divergent) and profile curvature (concave, convex and straight) nine different geometries are created. In prediction of the surface and subsurface runoff of catchments based on saturation excess runoff mechanism, the saturated and unsaturated zones of hillslopes must be first separated. Subsurface travel time of hillslope is dependent on saturation attributes. In this research, a new saturation model, called Gamma, was developed to predict the saturated zone length and subsurface travel time in complex hillslopes. An analytical formula was introduced to calculate saturation zone length in Gamma model. Results of Gamma model, namely the saturation zone length and subsurface travel time, were compared with the results given by two other complex saturation models W and Sigma. The results of the three models were relatively close to each other in convergent and parallel hillslopes of different profile curvature type. However, due to the existence of an analytical equation for estimation of saturated zone length in the Gamma model, this model is recommended. It should be noted that for straight divergent and convex divergent hillslopes, the Gamma model is not suitable and Sigma or W model should be used

A steady-state saturation model to determine the subsurface travel time (STT) in complex hillslopes

The travel time of subsurface flow in complex hillslopes (hillslopes with different plan shape and profile curvature) is an important parameter in predicting the subsurface flow in catchments. This time depends on the hillslopes geometry (plan shape and profile curvature), soil properties and climate conditions. The saturation capacity of hillslopes affect the travel time of subsurface flow. The saturation capacity, and subsurface travel time of compound hillslopes depend on parameters such as soil depth, porosity, soil hydraulic conductivity, plan shape (convergent, parallel or divergent), hillslope length, profile curvature (concave, straight or convex) and recharge rate to the groundwater table. An equation for calculating subsurface travel time for all complex hillslopes was presented. This equation is a function of the saturation zone length (SZL) on the surface. Saturation zone length of the complex hillslopes was calculated numerically by using the hillslope-storage kinematic wave equation for subsurface flow, so an analytical equation was presented for calculating the saturation zone length of the straight hillslopes and all plan shapes geometries. Based on our results, the convergent hillslopes become saturated very soon and they showed longer SZL with shorter travel time compared to the parallel and divergent ones. The subsurface average flow rate in convergent hillslopes is much less than the divergent ones in the steady state conditions. Concerning to subsurface travel time, convex hillslopes have more travel time in comparison to straight and concave hillslopes. The convex hillslopes exhibit more average flow rate than concave hillslopes and their saturation capacity is very low. Finally, the effects of recharge rate variations, average bedrock slope and soil depth on saturation zone extension were investigated

Green Synthesis, Characterization, and Biological Evaluation of Hydroxyl-Capped Tellurium Nanoparticles

In this study, we used a simple green method for preparing tellurium nanoparticles and mainly evaluated their toxicological effects. The nanoparticles were synthesized using lactose and characterized with different instrumentation methods. The in vitro and in vivo cytotoxicity of tellurium nanoparticles and its effect on lipid profile were also evaluated. Hydroxyl-capped tellurium nanoparticles were successfully fabricated by lactose. The results showed spherical tellurium nanoparticles with a mean size of 89 nm. The toxicological study showed that the tellurium nanoparticles did not exhibit any toxicity on the primary cells. The LD50 values for the nanoparticles were 327 and 295 mg/kg for oral and intraperitoneal administrations, respectively. Also, the results showed a significant reduction in liver enzymes at the 16, 24, and 40 mg/kg doses. Hematological parameters indicated no significant suppressive changes between the animals that were administered tellurium nanoparticles and the control group. In addition, the effects of tellurium nanoparticles on hypercholesterolemic risk factors in mice fed with cholesterol demonstrated the depletion of triglyceride, cholesterol, and low-density lipoprotein. This study showed that the toxicity of tellurium nanoparticles was lower than tellurium ions. Furthermore, tellurium nanoparticles decreased the cholesterol and triglyceride levels in the animal model

I love being a midwife; it\u27s who I am : A Glaserian Grounded Theory Study of why midwives stay in midwifery

Aims and objectives: To understand why Western Australian (WA) midwives choose to remain in the profession. Background: Midwifery shortages and the inability to retain midwives in the midwifery profession is a global problem. The need for effective midwifery staff retention strategies to be implemented is therefore urgent, as is the need for evidence to inform those strategies. Design: Glaserian grounded theory (GT) methodology was used with constant comparative analysis. Methods: Fourteen midwives currently working clinically area were interviewed about why they remain in the profession. The GT process of constant comparative analysis resulted in an overarching core category emerging. The study is reported in accordance with Tong and associates’ (2007) Consolidated Criteria for Reporting Qualitative Research (COREQ). Results: The core category derived from the data was labelled—“I love being a midwife; it\u27s who I am.” The three major categories that underpin the core category are labelled as follows: “The people I work with make all the difference”; “I want to be ‘with woman’ so I can make a difference”; and “I feel a responsibility to pass on my skills, knowledge and wisdom to the next generation.” Conclusion: It emerged from the data that midwives’ ability to be “with woman” and the difference they feel they make to them, the people they work with and the opportunity to “grow” the next generation together underpin a compelling new middle‐range theory of the phenomenon of interest. Relevance to clinical practice: The theory that emerged and the insights it provides will be of interest to healthcare leaders, who may wish to use it to help develop midwifery workforce policy and practice, and by extension to optimise midwives’ job satisfaction, and facilitate the retention of midwives both locally and across Australia

Withanolides-Induced Breast Cancer Cell Death Is Correlated with Their Ability to Inhibit Heat Protein 90

Withanolides are a large group of steroidal lactones found in Solanaceae plants that exhibit potential anticancer activities. We have previously demonstrated that a withanolide, tubocapsenolide A, induced cycle arrest and apoptosis in human breast cancer cells, which was associated with the inhibition of heat shock protein 90 (Hsp90). To investigate whether other withanolides are also capable of inhibiting Hsp90 and to analyze the structure-activity relationships, nine withanolides with different structural properties were tested in human breast cancer cells MDA-MB-231 and MCF-7 in the present study. Our data show that the 2,3-unsaturated double bond-containing withanolides inhibited Hsp90 function, as evidenced by selective depletion of Hsp90 client proteins and induction of Hsp70. The inhibitory effect of the withanolides on Hsp90 chaperone activity was further confirmed using in vivo heat shock luciferase activity recovery assays. Importantly, Hsp90 inhibition by the withanolides was correlated with their ability to induce cancer cell death. In addition, the withanolides reduced constitutive NF-κB activation by depleting IκB kinase complex (IKK) through inhibition of Hsp90. In estrogen receptor (ER)-positive MCF-7 cells, the withanolides also reduced the expression of ER, and this may be partly due to Hsp90 inhibition. Taken together, our results suggest that Hsp90 inhibition is a general feature of cytotoxic withanolides and plays an important role in their anticancer activity

Anterior cruciate ligament reconstruction is associated with greater tibial tunnel widening when using a bioabsorbable screw compared to an all-inside technique with suspensory fixation

Purpose: To compare clinical outcomes and tunnel widening following anterior cruciate ligament reconstruction (ACLR) performed with an all-inside technique (Group A) or with a bioabsorbable tibial screw and suspensory femoral fixation (Group B). Methods: Tunnel widening was assessed using computed tomography (CT) and a previously validated analytical best fit cylinder technique at approximately 1-year following ACLR. Clinical follow-up comprised evaluation with IKDC, KSS, Tegner, Lysholm scores, and knee laxity assessment. Results: The study population comprised 22 patients in each group with a median clinical follow-up of 24 months (range 21–27 months). The median duration between ACLR and CT was 13 months (range 12–14 months). There were no significant differences in clinical outcome measures between groups. There were no differences between groups with respect to femoral tunnel widening. However, there was a significantly larger increase in tibial tunnel widening, at the middle portion, in Group B (2.4 ± 1.5 mm) compared to Group A (0.8 ± 0.4 mm) (p = 0.027), and also at the articular portion in Group B (1.5 ± 0.8 mm) compared to Group A (0.8 ± 0.8 mm) (p = 0.027). Conclusion: Tibial tunnel widening after ACLR using hamstring tendon autograft is significantly greater with suspensory femoral fixation and a bioabsorbable tibial interference screw when compared to an all-inside technique at a median follow-up of 2 years. The clinical relevance of this work lies in the rebuttal of concerns arising from biomechanical studies regarding the possibility of increased tunnel widening with an all-inside technique. Level of evidence: III