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A Simplified Model for Portfolio Analysis A SIMPLIFIED MODEL FOR PORTFOLIO ANALYSIS*
No full textJSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. INFORMS is collaborating with JSTOR to digitize, preserve and extend access to Management Science. http://www.jstor.org A SIMPLIFIED MODEL FOR PORTFOLIO ANALYSIS* WILLIAM F. SHARPEt University of Washington This paper describes the advantages of using a particular model of the relationships among securities for practical applications of the Markowitz portfolio analysis technique. A computer program has been developed to take full advantage of the model: 2,000 securities can be analyzed at an extremely low cost-as little as 2% of that associated with standard quadratic programming codes. Moreover, preliminary evidence suggests that the relatively few parameters used by the model can lead to very nearly the same results obtained with much larger sets of relationships among securities. The possibility of low-cost analysis, coupled with a likelihood that a relatively small amount of information need be sacrificed make the model an attractive candidate for initial practical applications of the Markowitz technique
IC/98/133 United Nations Educational Scientific and Cultural Organization and International Atomic Energy Agency THE ABDUS SALAM INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS IONIC CLUSTERS IN ALUMINIUM -SODIUM FLUORIDE MELTS
No full textAbstract From Raman scattering experiments three types of charged AlFn cluster (with n ~ 4, 5 and 6) have been proposed to coexist in liquid alkali fluoroaluminates such as cryolite (Na3AlF6). We characterize these isolated clusters by a phenomenological ionic model and employ it to examine how local screening of the excess charge on a cluster may be effected by sodium ions at various compositions in the liquid. We provide the first theoretical explanation for the stability of the AIF5 cluster at the compositions Na3AlF6 and Na2AlF5
No full textAbstract In this paper, we propose a recognition-based image authentication system, named "Awase-E"
BIOANALYTICAL METHOD DEVELOPMENT AND VALIDATION OF PIRFENIDONE BY RPHPLC METHOD AND ITS APPLICATION TO THE DETERMINATION OF DRUG FOOD INTERACTION STUDY IN WISTER RATS
No full textABSTRACT A simple precise, accurate RP-HPLC method has been developed and validated for bioavailability study of pirfenidone in wister rat plasma. The separation and quantization of pirfenidone was achieved on a C18 reversed phase column using the mobile phase in gradient mode constituting of eluant A HPLC grade water (adjusted to pH 3.5) and eluant B 20% acetonitrile and 15% of methanol in the ratio of 60: 40 at a flow rate 1 mlmin -1 . Eluted components were detected at 324 nm. The method showed good linearity for Pirfenidone in the range of 50-250ng mL -1 , Y=54.97x -349.5and correlation coefficient R 2 is 0.998 respectively. The limit of quantitation (LOQ) and limit of detection (LOD) were found to be 12 and 20 ng mL -1 respectively.The developed method shows good accuracy and precision. . Accuracy ranges from 98.49% to 99.37% with the precision 6.43% to 7.67% in inter-day method. Intra-day method the accuracy ranges from 98.64% to 99.33% with the precision 5.64% to 6.93 %. For bioanalytical study, parameters like C max, T max, AUC0-t, AUC 0-∞, K eli and T 1/2 are compared by statistical analysis. The maximum concentration (C max ) obtained for pirfenidone before and after food was found to be 1020.76 ng mL -1 and 836.5ng mL -1 respectively. The half life (T 1/2 ) of pirfenidone before and after food were calculated and found to be 2.732158 h and 4.009485 h respectively. Area under the AUC was found to be 2510.64ng mL -1 . Elimination rate constant for Pirfenidone was found to be 0.004228 h -1 and 0.002881 h -1 respectively. This method was successfully applied to the bioavailability study of pirfenidone
Heun equation, Teukolsky equation, and type-D metrics
No full textAbstract Starting with the whole class of type-D vacuum backgrounds with cosmological constant we show that the separated Teukolsky equation for zero rest-mass fields with spin s = ±2 (gravitational waves), s = ±1 (electromagnetic waves) and s = ±1/2 (neutrinos) is an Heun equation in disguise
Update on electron-cloud power deposition for the LHC arc dipoles
No full textWe revisit the estimation of the power deposited by the electron cloud (EC) in the arc dipoles of the LHC by means of simulations. We adopt, as simulation input, a set of electron-related parameters closely resembling those used in recent simulations at CER
Advances in the study of the mechanisms involved in the modulation of the expression of sclerostin in human cells Work rewarded with the scholarship investigation FEIOMM 2011
No full textSummary Sclerostin plays an important role in the regulation of bone metabolism, as is shown in the dramatic changes in bone mass which occur when its activity is inhibited by means of monoclonal antibodies. However, the mechanisms which regulate its expression are still not well-understood. Various studies have shown an association between polymorphisms of the SOST gene promoter (which codes for sclerostin) and bone mineral density. Also, the degree of methylation of a CpG island near the start of the transcription is associated with marked changes in the expression of the gene. Therefore, it appears that the production of sclerostin is influenced by both genetic and epigenetic mechanisms, in addition to other hormonal and mechanical factors. A greater knowledge of these mechanisms would not only contribute to a better understanding of bone biology, but could open up new therapeutic opportunities
15+ MILLION TOP 1% MOST CITED SCIENTIST 12.2% AUTHORS AND EDITORS FROM TOP 500 UNIVERSITIES 3 Impact of Sewage and Industrial Effluents on Soil-Plant Health
No full textChemical and biological recovery from acid deposition within the Honnedaga Lake watershed, New York, USA
No full textAbstract Honnedaga Lake in the Adirondack region of New York has sustained a heritage brook trout population despite decades of atmospheric acid deposition. Detrimental impacts from acid deposition were observed from 1920 to 1960 with the sequential loss of acid-sensitive fishes, leaving only brook trout extant in the lake. Open-lake trap net catches of brook trout declined for two decades into the late 1970s, when brook trout were considered extirpated from the lake but persisted in tributary refuges. Amendments to the Clean Air Act in 1990 mandated reductions in sulfate and nitrogen oxide emissions. By 2000, brook trout had re-colonized the lake coincident with reductions in surface-water sulfate, nitrate, and inorganic monomeric aluminum. No changes have been observed in surfacewater acid-neutralizing capacity (ANC) or calcium concentration. Observed increases in chlorophyll a and decreases in water clarity reflect an increase in phytoplankton abundance. The zooplankton community exhibits low species richness, with a scarcity of acidsensitive Daphnia and dominance by acid-tolerant copepods. Trap net surveys indicate that relative abundance of adult brook trout population has significantly increased since the 1970s. Brook trout are absent in 65 % of tributaries that are chronically acidified with ANC of <0 μeq/L and toxic aluminum levels (>2 μmol/ L). Given the current conditions, a slow recovery of chemistry and biota is expected in Honnedaga Lake and its tributaries. We are exploring the potential to accelerate the recovery of brook trout abundance in Honnedaga Lake through lime applications to chronically and episodically acidified tributaries