3,878 research outputs found
Updating the Estimation of the Supply of Storage Model
An updated supply of storage equation is estimated to reflect recent developments in the theoretical and empirical literature. Among the findings is an inverse relationship between storage cost adjusted price spread and a proxy measure of convenience yield, and a curvilinear relationship between stocks-to-use ratio and implied volatility.supply of storage, implied volatility, convenience yield, Research Methods/ Statistical Methods, Q11, Q14, G10,
Extinction by Miscalculation:
Species at Risk Act, Sakinaw sockeye, Cultus sockeye, fisheries management, extinction.
Structure and Magnetic Fields in the Precessing Jet System SS 433 II. Intrinsic Brightness of the Jets
Deep Very Large Array imaging of the binary X-ray source SS 433, sometimes
classified as a microquasar, has been used to study the intrinsic brightness
distribution and evolution of its radio jets. The intrinsic brightness of the
jets as a function of age at emission of the jet material tau is recovered by
removal of the Doppler boosting and projection effects. We find that
intrinsically the two jets are remarkably similar when compared for equal tau,
and that they are best described by Doppler boosting of the form D^{2+alpha},
as expected for continuous jets. The intrinsic brightnesses of the jets as
functions of age behave in complex ways. In the age range 60 < tau < 150 days,
the jet decays are best represented by exponential functions of tau, but linear
or power law functions are not statistically excluded. This is followed by a
region out to tau ~ 250 days during which the intrinsic brightness is
essentially constant. At later times the jet decay can be fit roughly as
exponential or power law functions of tau.Comment: 30 Pages, 11 Figures, Submitted to Ap
Development of a Case Study Problem in Engineering Economics Based on a Telephone Replacement Undertaking at UW-Platteville
General Engineering 2820 (GE 2820) is a course offered to all undergraduate students at the College of Engineering, Mathematics, and Science (EMS), University of Wisconsin –Platteville. A constant exercise for the instructors in this course is to update the course material with interesting case study problems which are then solved by students as an assignment. In recent days, the University of Wisconsin –Platteville, is contemplating replacement of its current Voice over IP (VoIP) phone service (catered by the local utility company “Century Link”) with a “Unified Communications” service. Current services cost the university 7000 per month. Therefore, a breakeven analysis was undertaken for studying the economic feasibility of this undertaking by the students in this course. Part of this case study involved – defining the problem correctly, processing the interest rate data so as to calculate an appropriate effective annual rate, processing the financial data related to the phone services, and finally performing a breakeven study using the annual worth computation. Based on student performances, such case study problems have benefited the students in understanding the concepts of time value of money and various method of analysis in engineering economy
The 1.23 Ga Fjellhovdane rhyolite, Grøssæ-Totak; a new age within the Telemark supracrustals, southern Norway
The Grøssæ-Totak supracrustal belt is part of the several-kilometre thick Telemark supracrustal sequences that are exposed in southern Norway. Deposition of the Telemark supracrustals spans the period between Telemarkian continental growth at ~1.52-1.48 Ga and Sveconorwegian orogenesis associated with continental collision at ~1.1-0.9 Ga. The timing of deposition is largely constrained by U-Pb geochronology of detrital zircons in sedimentary units, and igneous zircons within felsic volcanics. A younger Supergroup that has been referred to as the Sveconorwegian Supergroup comprises depositional ages younger than 1.16 Ga; units of the Grøssae-Totak belt have been mapped as part of this Supergroup. This study presents a new U-Pb age of 1233 ± 29 Ma for the Fjellhovdane rhyolite, one of the lowermost units within the Grøssæ-Totak belt; this age suggests that at least the lower part of this sequence is not part of the Sveconorwegian Supergroup, but formed in an earlier volcano-sedimentary basin that is correlative in age to the Sæsvatn-Valldal and Setesdal supracrustal belts that occur to the west and south respectively. The geochemistry of the Fjellhovdane rhyolite is compatible with crustal melting of previously-formed supra-subduction rocks, as has been advocated for the Sæsvatn-Valldal rhyolites
Behavioral family intervention for children with developmental disabilities and behavioral problems
The outcomes of a randomized clinical trial of a new behavioral family intervention, Stepping Stones Triple P, for preschoolers with developmental and behavior problems are presented. Forty-eight children with developmental disabilities participated, 27 randomly allocated to an intervention group and 20 to a wait-list control group. Parents completed measures of parenting style and stress, and independent observers assessed parent-child interactions. The intervention was associated with fewer child behavior problems reported by mothers and independent observers, improved maternal and paternal parenting style, and decreased maternal stress. All effects were maintained at 6-month follow-up
Probing the molecular orientation of a single conjugated polymer via nano-gap SERS
Determining the molecular orientation at the single molecule level is of key importance for a wide range of applications ranging from molecular electronic devices to biomedical applications. In this work surface-enhanced Raman scattering (SERS) was used to probe the light-emitting conjugated polymer F8-PFB at the single molecule level using nanoparticles on an extended metallic film nanogap. The directional field enhancement of the nanogap combined with density functional theory (DFT) calculations was used to determine the orientation of the molecule. This analysis revealed that the spin-coated conjugated polymer preferentially aligns its molecular chains parallel to the metallic substrate. The integration of this approach in nanofabrication and synthesis will have a profound impact on different fields ranging from molecular electronic devices to biomedical applications
Dopamine Pathology in Schizophrenia: Analysis of Total and Phosphorylated Tyrosine Hydroxylase in the Substantia Nigra
Introduction: Despite the importance of dopamine neurotransmission in schizophrenia, very few studies have addressed anomalies in the mesencephalic dopaminergic neurons of the substantia nigra/ventral tegmental area (SN/VTA). Tyrosine hydroxylase (TH) is the rate-limiting enzyme for the production of dopamine, and a possible contributor to the anomalies in the dopaminergic neurotransmission observed in schizophrenia. Objectives: In this study, we had three objectives: (1) Compare TH expression (mRNA and protein) in the SN/VTA of schizophrenia and control postmortem samples. (2) Assess the effect of antipsychotic medications on the expression of TH in the SN/VTA. (3) Examine possible regional differences in TH expression anomalies within the SN/VTA. Methods: To achieve these objectives three independent studies were conducted: (1) A pilot study to compare TH mRNA and TH protein levels in the SN/VTA of postmortem samples from schizophrenia and controls. (2) A chronic treatment study was performed in rodents to assess the effect of antipsychotic medications in TH protein levels in the SN/VTA. (3) A second postmortem study was performed to assess TH and phosphorylated TH protein levels in two types of samples: schizophrenia and control samples containing the entire rostro-caudal extent of the SN/VTA, and schizophrenia and control samples containing only mid-caudal regions of the SN/VTA. Results and Conclusion: Our studies showed impairment in the dopaminergic system in schizophrenia that could be mainly (or exclusively) located in the rostral region of the SN/VTA. Our studies also showed that TH protein levels were significantly abnormal in schizophrenia, while mRNA expression levels were not affected, indicating that TH pathology in this region may occur posttranscriptionally. Lastly, our antipsychotic animal treatment study showed that TH protein levels were not significantly affected by antipsychotic treatment, indicating that these anomalies are an intrinsic pathology rather than a treatment effect
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