42 research outputs found
Evaluating energy harvesting from water distribution networks using combined stakeholder and social network analysis
This is the final version. Available from Elsevier via the DOI in this record. Data availability:
Data will be made available on request.The chance of success in implementing a new project in a water distribution network (WDN) significantly depends on the behaviour of the involved stakeholders. In this paper, the feasibility of installing the micro-turbines
in WDNs for generating hydro-power energy is studied from the stakeholders’ perspective. Stakeholders’ analysis
(SA) and social network analysis (SNA) are performed to methodically recognise the environment and the relationships among stakeholders. 18 stakeholders at the local, regional, and national levels were identified and
their representatives were interviewed. In SA, the power, interest, access to information, and satisfaction from
the current condition of the system were evaluated for each stakeholder. The Water and Wastewater Company
and Ministry of Energy were found as the stakeholders with the highest power and interest. Unexpectedly, the
Regional Electricity Company was discovered with medium power and low access to information. In SNA,
cooperative and non-cooperative relationships between stakeholders were analysed and an assessment was made
for the role of each stakeholder in their social network, through four centrality metrics. The correlation between
SA and SNA results suggests that SA factors could be estimated using the SNA metrics.Iran National Science Foundation (INSF
New insights into the pathogenesis of glucocorticoid-induced avascular necrosis: microarray analysis of gene expression in a rat model
Two-photon spin injection in semiconductors
A comparison is made between the degree of spin polarization of electrons
excited by one- and two-photon absorption of circularly polarized light in bulk
zincblende semiconductors. Time- and polarization-resolved experiments in
(001)-oriented GaAs reveal an initial degree of spin polarization of 49% for
both one- and two-photon spin injection at wavelengths of 775 and 1550 nm, in
agreement with theory. The macroscopic symmetry and microscopic theory for
two-photon spin injection are reviewed, and the latter is generalized to
account for spin-splitting of the bands. The degree of spin polarization of
one- and two-photon optical orientation need not be equal, as shown by
calculations of spectra for GaAs, InP, GaSb, InSb, and ZnSe using a 14x14 k.p
Hamiltonian including remote band effects. By including the higher conduction
bands in the calculation, cubic anisotropy and the role of allowed-allowed
transitions can be investigated. The allowed-allowed transitions do not
conserve angular momentum and can cause a high degree of spin polarization
close to the band edge; a value of 78% is calculated in GaSb, but by varying
the material parameters it could be as high as 100%. The selection rules for
spin injection from allowed-allowed transitions are presented, and interband
spin-orbit coupling is found to play an important role.Comment: 12 pages including 7 figure
Significant association of SREBP-2 genetic polymorphisms with avascular necrosis in the Korean population
<p>Abstract</p> <p>Background</p> <p>It is known that steroid usage and alcohol abuse are major etiological factors in the development of avascular necrosis (AVN), a bone disease that produces osteonecrosis of the femoral head. The facilitation of fat biosynthesis by steroids and alcohol disrupts the blood supply into the femoral head. <it>SREBP-2 </it>plays a central role in the maintenance of lipid homeostasis through stimulating expression of genes associated with cholesterol biosynthetic pathways. The aim of this study was to examine the association between the polymorphisms of the <it>SREBP-2 </it>gene and AVN susceptibility in the Korean population.</p> <p>Methods</p> <p>Four single nucleotide polymorphisms (SNP) in the <it>SREBP-2 </it>gene, IVS1+8408 T>C (rs2267439), IVS3-342 G>T (rs2269657), IVS11+414 G>A (rs1052717) and IVS12-1667 G>A (rs2267443), were selected from public databases and genotyped in 443 AVN patients and 273 control subjects by using single-based extension (SBE) genotyping.</p> <p>Results</p> <p>The minor allele (C) frequency of rs2267439 showed a significant protective effect on AVN (P = 0.01, OR; 0.75, 95% CI; 0.604–0.935), and the genotype frequencies of this polymorphism were also different from the controls in all alternative analysis models (P range, 0.009–0.03, OR; 0.647–0.744). In contrast, rs1052717 and rs2267443 polymorphisms were significantly associated with AVN risk. Further analysis based on pathological etiology showed that the genotypes of rs2267439, rs1052717 and rs2267443 were also significantly associated with AVN susceptibility in each subgroup.</p> <p>Conclusion</p> <p>This study is the first report to evaluate the association between <it>SREBP-2 </it>gene polymorphisms and the susceptibility of AVN in the Korean population.</p
HGF-Transgenic MSCs Can Improve the Effects of Tissue Self-Repair in a Rabbit Model of Traumatic Osteonecrosis of the Femoral Head
BACKGROUND: Osteonecrosis of the femoral head (ONFH) is generally characterized as an irreversible disease and tends to cause permanent disability. Therefore, understanding the pathogenesis and molecular mechanisms of ONFH and developing effective therapeutic methods is critical for slowing the progress of the disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, an experimental rabbit model of early stage traumatic ONFH was established, validated, and used for an evaluation of therapy. Computed tomography (CT) and magnetic resonance (MR) imaging confirmed that this model represents clinical Association Research Circulation Osseous (ARCO) phase I or II ONFH, which was also confirmed by the presence of significant tissue damage in osseous tissue and vasculature. Pathological examination detected obvious self-repair of bone tissue up to 2 weeks after trauma, as indicated by revascularization (marked by CD105) and expression of collagen type I (Col I), osteocalcin, and proliferating cell nuclear antigen. Transplantation of hepatocyte growth factor (HGF)-transgenic mesenchymal stem cells (MSCs) 1 week after trauma promoted recovery from ONFH, as evidenced by a reversed pattern of Col I expression compared with animals receiving no therapeutic treatment, as well as increased expression of vascular endothelial growth factor. CONCLUSIONS/SIGNIFICANCE: These results indicate that the transplantation of HGF-transgenic MSCs is a promising method for the treatment for ONFH and suggest that appropriate interference therapy during the tissue self-repair stage contributes to the positive outcomes. This study also provides a model for the further study of the ONFH etiology and therapeutic interventions
Salvianolic Acid B Prevents Bone Loss in Prednisone-Treated Rats through Stimulation of Osteogenesis and Bone Marrow Angiogenesis
Glucocorticoid (GC) induced osteoporosis (GIO) is caused by the long-term use of GC for treatment of autoimmune and inflammatory diseases. The GC related disruption of bone marrow microcirculation and increased adipogenesis contribute to GIO development. However, neither currently available anti-osteoporosis agent is completely addressed to microcirculation and bone marrow adipogenesis. Salvianolic acid B (Sal B) is a polyphenolic compound from a Chinese herbal medicine, Salvia miltiorrhiza Bunge. The aim of this study was to determine the effects of Sal B on osteoblast bone formation, angiogenesis and adipogenesis-associated GIO by performing marrow adipogenesis and microcirculation dilation and bone histomorphometry analyses. (1) In vivo study: Bone loss in GC treated rats was confirmed by significantly decreased BMD, bone strength, cancellous bone mass and architecture, osteoblast distribution, bone formation, marrow microvessel density and diameter along with down-regulation of marrow BMPs expression and increased adipogenesis. Daily treatment with Sal B (40 mg/kg/d) for 12 weeks in GC male rats prevented GC-induced cancellous bone loss and increased adipogenesis while increasing cancellous bone formation rate with improved local microcirculation by capillary dilation. Treatment with Sal B at a higher dose (80 mg/kg/d) not only prevented GC-induced osteopenia, but also increased cancellous bone mass and thickness, associated with increase of marrow BMPs expression, inhibited adipogenesis and further increased microvessel diameters. (2) In vitro study: In concentration from 10−6 mol/L to 10−7 mol/L, Sal B stimulated bone marrow stromal cell (MSC) differentiation to osteoblast and increased osteoblast activities, decreased GC associated adipogenic differentiation by down-regulation of PPARγ mRNA expression, increased Runx2 mRNA expression without osteoblast inducement, and, furthermore, Sal B decreased Dickkopf-1 and increased β-catenin mRNA expression with or without adipocyte inducement in MSC. We conclude that Sal B prevented bone loss in GC-treated rats through stimulation of osteogenesis, bone marrow angiogenesis and inhibition of adipogenesis
Optimal energy harvesting plans in water distribution networks considering the stakeholders’ utilities
This is the author accepted manuscript. the final version is available from Elsevier via the DOI in this recordData availability: Data will be made available on request.This paper delves into identifying the optimal scenario for the implementation of micro-turbines, specifically Pump-as-Turbines (PaTs), in a water distribution network (WDN) by achieving the highest consensus among the involved stakeholders. Utilising a simulations-optimisation model, the best location, type, and operation hours for micro-turbines were selected within a case study WDN. The objective was to maximise the generated energy, while maintaining the standard hydraulic conditions of the WDN. A total of 84 scenarios were developed, considering the number of installed turbines, allocation of the generated energy, and pricing schemes. The scenarios explore the possibilities of allocating the generated electricity to the water company, national grid, cryptocurrency mining, or electric car charging. Evaluation of the scenarios involves 36 criteria, and the study identifies 18 stakeholders involved in water and energy management within the case study. Stakeholder utility with respect to the criteria was determined through interviews, and weights for each stakeholder were assigned based on previous studies. The utility of each scenario was computed in a matrix, and scenarios were ranked accordingly, revealing that the scenario involving the generation of electricity by five turbines sold to the grid at twice the current price garnered the highest stakeholder support.Iran National Science Foundation (INSF
SYSTEM DYNAMICS-BASED CONFLICT RESOLUTION MODEL FOR RIVER WATER QUALITY MANAGEMENT
System dynamics approach by simulating a bargaining process can be used
for resolving conflict of interests in water quality management. This
approach can be a powerful alternative for traditional approaches for
conflict resolution, which often rely on classical game theory. Waste
load allocation models for river water quality management determine the
optimal monthly waste load allocation to each point load. Most of these
approaches are based on the multi-objective optimization models and do
not consider the existing conflicts. In this study, a system
dynamics-based conflict resolution model is presented for monthly waste
load allocation in river systems. In this model, the stakeholders and
decision-makers negotiate with each other considering their relative
authorities, aspirations and dissatisfactions. System dynamics approach
is actually used for simulating the bargaining process among the
players. The model incorporates the objectives and preferences of
stakeholders and decision-makers of the system in the form of utility
functions and could provide a final agreement among the players. To
evaluate the spatial and temporal variation of the concentration of the
water quality indicator in the system, a water quality simulation model
is also linked to the conflict resolution model. In the proposed model,
a pre-assigned utility is allocated to different water users and the
results are evaluated using a simulation model. The allocated utilities
are tested and adjusted in order to provide an agreement between the
assumed utilities and the utilities assigned by the model. The proposed
model is applied to the Karkheh River system located in the southwest
of Iran. The results show that the model can effectively incorporate
the preferences of the players in providing a final agreement and the
runtime of the proposed model is much less than the classical conflict
resolution models. It is also shown that the waste load allocation can
significantly reduce number and duration of the periods in which the
river water quality violates the standards
Enhancing spatial resolution of GRACE-derived groundwater storage anomalies in Urmia catchment using machine learning downscaling methods
The Urmia lake in north-west Iran has dried up to perilously low levels in the past two decades. In this study, we investigate the drivers behind the decline in lake water level with the help of in-situ and remote sensing data. We use total water storage (TWS) changes from the gravity recovery and climate experiment (GRACE) satellite mission. TWS from GRACE includes all the water storage compartments in a column and is the only remote sensing product that can help in estimating groundwater storage (GWS) changes. The coarse spatial (approx. 300 km) resolution of GRACE does not allow us to identify local changes that may have led to the Urmia lake disaster. In this study, we tackle the poor resolution of the GRACE data by employing three machine learning (ML) methods including random forest (RF), support vector regression (SVR) and multi-layer perceptron (MLP). The methods predict the groundwater storage anomaly (GWSA), derived from GRACE, as a function of hydro-climatic variables such as precipitation, evapotranspiration, land surface temperature (LST) and normalized difference vegetation index (NDVI) on a finer scale of 0.25° × 0.25°. We found that i) The RF model exhibited highest R (0.98), highest NSE (0.96) and lowest RMSE (18.36 mm) values. ii) The RF downscaled data indicated that the exploitation of groundwater resources in the aquifers is the main driver of groundwater storage and changes in the regional ecosystem, which has been corroborated by few other studies as well. The impact of precipitation and evapotranspiration on the GWSA was found to be rather weak, indicating that the anthropogenic derivers had the most significant impact on the GWSA changes. iii) We generally observed a significant negative trend in GWSA, having also significant positive correlations with the well data. However, over regions with dam construction significant negative correlations were found.</p
High serum alpha-2-macroglobulin level in patients with osteonecrosis of the femoral head
Background: Diagnosis of osteonecrosis of the femoral head (ONFH) is complicated due to the lack of reliable serum biomarkers. Up-regulation of alpha-2-macroglobulin (A2M) gene has been reported in glucocorticoid-induced ANFH rat model. This study aimed to investigate whether the serum level of alpha-2-macroglobulin (A2M) can be used for ONFH diagnosis. Methods: Serum protein capillary electrophoresis was performed on the sera of 36 ONFH patients. Also, human enzyme-linked immunosorbent assay was performed to evaluate the serum levels of A2M. Results: Alpha-2 subunit level, composed of alpha-2-macroglobulin, ceruloplasmin and 2-2 haptoglobin phenotype, was increased significantly as compared to healthy subjects (P=0.0001). Moreover, ELISA assay confirmed significant elevation in the A2M (P=0.037). Conclusion: Our findings suggest that avascular necrotic femur head presumably directly or indirectly elevates A2M in the bloodstream. Thus, serum level of A2M might be used as a reliable diagnostic tool in clinical practice