119 research outputs found
A possible modulatory role of nitric oxide in paraquat-induced lung Injury in mice
No full textThe present study was undertaken to evaluate whether stimulation or inhibition of Nitric Oxide (NO)
synthesis could affect lung toxicity induced by acute administration of paraquat (PQ) in mice. L-arginine
(L-arg.), NG-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine (AG) were employed as NO precursor,
competitive and specific NO synthesis inhibitors, respectively. PQ was administered intraperitoneally to Swiss
albino mice at a single dose of 50 mg kg- 1 . L-arg. (700 mg k g - 1 day- 1), L-NAME (150 mg kg- 1 day- 1 ) or AG
(100 mg k g - 1 day- 1 ) was given in drinking water of mice for 5 days before and one day after PQ
administration. Appropriate controls were performed. PQ administration resulted in a pronounced elevation in
lipid peroxides (157%) as well as decreased activity of alkaline phosphatase [ALP] (48%) and non-protein thiols
(40%) in lung tissue compared to control non-treated mice as evidences of lung injury. Serum level of NO end
products, nitrate and nitrite significantly elevated due to PQ administration (150%) as compared to control level.
In mice given combined treatment of L-arg. and PQ, a remarkable rise in the serum level of nitrate and nitrite
(140%) compared to the PQ group was observed. In addition, L-arg. ameliorated the increased level of lipid
peroxides and non-protein thiols depletion as well as the decreased activity of ALP caused by PQ respectively.
On the other hand, L-NAME and AG potentiated the deleterious effects of PQ on serum NO, lung lipid
peroxides content, non-protein thiols content and alkaline phosphatase activity. In conclusion, PQ-induced
lung injury in mice is alleviated by L-arg. but exacerbated by L-NAME and AG supplementation. This could
point out to a possible protective role of NO in PQ lung toxicity.Corresponding Author:
Ayman M. Gamal el-Din, Department of Pharmacology, College of Pharmacy,
King Saud University, P.O. Box 2457, Riyadh 11451, Kingdom of Saudi Arabia.
Email: [email protected]
Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in L abrador retrievers
No full textObjective
To determine repeatability of and correlation between 2 radiographic measurements of femoral anteversion angles (FAA) and to determine their influence on a score derived from tibial plateau angle (TPA) and FAA to predict the risk of cranial cruciate ligament disease (CCLD).
Study Design
Prospective clinical study.
Animals
Forty-eight Labrador retrievers with or without CCLD.
Methods
FAA and CCLD scores were calculated for each limb from extended pelvic radiographs (t-FAA) or angled (a-FAA) projections of the femur by 3 investigators. One investigator repeated measurements twice. Data were analyzed for repeatability, correlation between t-FAA and a-FAA, and their influence on CCLD scores.
Results
FAA correlated most strongly with the distance between the femoral head and the femoral axis on mediolateral radiographs, a measurement with excellent repeatability. t-FAA and a-FAA correlated with each other (r > 0.79, P < .0001), although t-FAA were about 1° greater than a-FAA (P = .01). Intrainvestigator and interinvestigator repeatability of the CCLD score was fair when derived from t-FAA and good to excellent when derived from a-FAA. CCLD scores differed between radiographic techniques but led to different predictions in only 9 (10%) limbs, all with lower TPA and CCLD scores than the rest of the population.
Conclusion
a-FAA correlated strongly with t-FAA and improved the repeatability of CCLD scores within and between investigators.
Clinical significance
A craniocaudal angled beam projection of the femur is a suitable alternative to a ventrodorsal pelvic radiograph when measuring FAA and may improve the repeatability and positive predictive value of CCLD scores
Gap Study for the Impact of Braced Deep Excavation on the Behavior of Excavation Bed
No full textTwo geotechnical topics were investigated in this research; shored deep excavation and modulus of subgrade reaction. Both topics were extensively studied by many earlier researchers. The aim of this study is to answer the following question, Is deep excavation effects on excavation bed behavior of sufficiently investigated? Or there still un-studied gaps should be fulfilled?”. Litterateurs were collected, reviewed and classified for both topics especially in the interaction zone between the two topics, and it is concluded that deep excavation effect on the modulus of subgrade reaction values and distribution at excavation bed level is not sufficiently addressed especially the effect of excavation bed heave and stiffness of shoring syste
Study of the Behavior of Floating Stone Columns in Soft Clay Formations Using Numerical Modeling
No full textOPTIMIZING CEMENT KILN DUST DENSITY TO IMPROVE LANDFILL AIR SPACE UTILIZATION
No full textOptimizing the density of waste materials in landfills by proper compaction prolongs the facility life due to the efficient use of landfill airspace. Cement kiln dust (CKD) is a waste by-product produced in huge amounts which exceeds the used quantities in the cement recycling industry and beneficial CKD applications. The vast amount of CKD is almost landfilled in its loose state in Egypt which causes a big loss in landfill airspace due to the low density of CKD. The hydraulic binder effect and dusty behavior of reactive CKD complicates its compaction process. Accordingly, this research was performed to investigate CKD compaction properties with three types of lubricants, which are potable water, salt water and waste oil. Maximum dry density (MDD) and optimum moisture content (OMC) for these lubricant types and different wetting methods were investigated in order to improve the landfill air space utilization and to reduce the dusty effect of CKD during compaction. The effect of immediate compaction after wetting and the effect of compaction delay by allowing CKD to hydrate initially for a certain period were studied. Compaction energy and methods of the wetting of CKD either by full submergence in water or prewetting were tested. The maximum weights of a disposed CKD and durations required to fill an intended landfill air space for different CKD conditions, lubricant types and compaction methods were presented for a case study in Ain Sokhna, Egypt.Optimiziranje gustoće otpadnih materijala na odlagalištima pravilnim zbijanjem produljuje vijek trajanja objekta zahvaljujući učinkovitom korištenju odlagališnog prostora. Prašina iz peći za dobivanje cementa (PDC) je otpadni nusproizvod koji nastaje u velikim količinama koje znatno premašuju količine materijala koji se može reciklirati u cementnoj industriji i korisno upotrijebiti na druge načine. Velika količina PDC-a u Egiptu se odlaže na odlagališta u rastresitom stanju, što uzrokuje veliki gubitak odlagališnog prostora zbog niske gustoće PDC-a. Učinak hidrauličkog veziva i ponašanje reaktivnog PDC-a kao prašinastog materijala komplicira proces njegovog zbijanja. U skladu s tim, ovo je istraživanje provedeno kako bi se ispitala svojstva zbijanja PDC-a s tri vrste ovlaživača/lubrikanata pitka voda, slana voda i otpadno ulje. Maksimalna suha gustoća i optimalni sadržaj vlage ispitani su za te vrste ovlaživača/lubrikanata i za različite metode vlaženja kako bi se poboljšala iskorištenost odlagališnog prostora i smanjio negativni učinak PDC-a tijekom zbijanja. Proučavani su učinak neposrednog zbijanja nakon vlaženja i učinak odgode zbijanja dopuštanjem PDC-u da se inicijalno hidratizira tijekom određenog razdoblja, a zatim odradi zbijanje. Ispitana je energija zbijanja i metode vlaženja PDC-a potpunim uranjanjem u fluid ili prethodnim vlaženjem. Prezentirane su maksimalne težine odloženog PDC-a i vrijeme potrebno za ispunjavanje predviđenog odlagališnog prostora za različite PDC uvjete, vrste ovlaživača/lubrikanata i metode zbijanja za studiju slučaja Ain Sokhna u Egiptu
Personalized Web Page Ranking Using Trust and Similarity
No full textSearch engines, like Google, use link structure to rank web pages. Although this approach provides an objective global estimate of the web page importance, it is not targeted to the specific user preferences. This paper presents a novel approach for the personalization of the results of a search engine based on the user's taste and preferences. The concepts of trust and similarity, captured from explicit user input and implicit user behavioral patterns, are used to compute personalized page rankings. © 2007 IEEE.AKTAS M, 2004, P 6 WEBKDD WORKSH; DERBAS G, 2004, P IEEEACS INT C PERV, P95; Eirinaki M., 2005, P 5 IEEE INT C DAT M; MABASHER B, 1999, TR01004; MASSA P, 2004, P INT C COOPER INFOR; MASSA P, 2005, ITCIRST TRENTO; Massa P, 2004, P 2 INT C TRUST MAN; Page L., 1998, PAGERANK CITATION RA; ZIEGLER CN, 2004, JOINT ICDEEDBT WORKS52
Data and R code from "Grazing and ecosystem service delivery in global drylands"
No full textThere are two zip files with the data and R scripts used in the article "Grazing and ecosystem service delivery in global drylands".
The file "Main_Data_code.zip" contains the data and R code used in the main analyses of the paper. These data also include the location and major environmental characteristics of the plots surveyed.
The file "Livestock_data_code.zip" contains the data and R code used in the characterization and validation of grazing pressure levels (see Methods). Readme and metadata files including a description of the files, variables and units are provided.
All the methodological details can be found in the article.
Additional authors from the BIODESERT consortium not included in the author list (we reached the maximum number of authors allowed by figshare) include: Víctor Rolo, Juan G. Rubalcaba, Jan C. Ruppert, Ayman Salah, Max A. Schuchardt, Sedona Spann, Ilan Stavi, Colton R. A.Stephens, Anthony M. Swemmer, Alberto L. Teixido, Andrew D. Thomas, Heather L. Throop, Katja Tielbörger, Samantha Travers, James Val, Orsolya Valkó, Liesbeth van den Brink, Sergio Velasco Ayuso, Frederike Velbert, Wanyoike Wamiti, Deli Wang, Lixin Wang, Glenda M. Wardle, Laura Yahdjian, Eli Zaady, Yuanming Zhang and Xiaobing Zhou </p
Behavior of Embankments Constructed on Soft Soil Deposits Reinforced with Rigid Inclusions
No full textLarge settlement associated with the construction of embankments on soft soil deposits is a challenging geotechnical problem that needs a special treatment. Reinforcing the embankments utilizing geosynthetics is an effective technique used to reduce the differential settlement, while the total settlement is unchanged. A more efficient technique is utilizing a combination between soft soil reinforcement using piles or rigid inclusions, thus increasing the equivalent stiffness of the entire soft soil stratum, and a load transfer layer reinforced by one or more layers of geosynthetics on top of the inclusions' head, in order to improve the load distribution process between the rigid elements. In this paper, the behavior of soft soil deposits reinforced with rigid inclusions is studied using three-dimensional finite element analysis, utilizing the "PLAXIS 3D 2020" software. Verification of the adopted modeling procedures is performed by the back analysis of a well-documented case study of a physical laboratory scaled model. Results of the numerical model showed a good agreement with the laboratory measurements in terms of both the settlement and load distribution aspects. Furthermore, results of both the developed numerical model and selected performed numerical analyses, from the literature, for the same case study, were compared showing better efficiency of the developed model compared to others and more consistency with the real behavior of the laboratory model. The verified model confirmed the efficiency of increasing the friction angle of the embankment on the load transfer mechanism between the rigid inclusions, and hence decreasing the resultant settlement
Análise da aprendizagem organizacional: contribuições para o processo de mudança
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Quando se trata de desenvolvimento institucional, um dos itens que identifica-se são as mudanças que os próprios membros de uma organização percebem como necessárias para torná-la mais capaz de atingir seus objetivos e cumprir sua missão. Isto impõe que seus dirigentes aprendam a definir, implementar e gerir estratégias de mudanças organizacionais que sejam viáveis, criem novos consensos na organização e a tornem capaz de adequar-se às mudanças do ambiente. Projetos de mudança bem sucedidos não são meros resultados da vontade. É preciso concebê-los como parte de um processo inovador de aprendizagem sobre a dinâmica da organização e sobre as potencialidades individuais e coletivas. Desta maneira, deve ser tratado como qualquer projeto, sendo necessário: definir objetivos; avaliar e construir a viabilidade; implementar, monitorar e redirecionar; avaliar e consolidar. Os elementos fundamentais numa estratégia de mudança são a clareza sobre os níveis de mudança prioritários, a definição de seus objetivos, a compreensão das fases do processo, a participação e, por fim, a ação frente às resistências
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