Performance of a Native Butterfly and Introduced Moth on Native and Introduced Lineages of Phragmites australis

This study examined the performance of Poanes viator (Edwards) (Hesperiidae), a native North American skipper, and Rhizedra lutosa (Hübner) (Noctuidae), an introduced moth, reared on native and non-native, invasive lineages of Phragmites australis. Poanes viator is a generalist on monocots and larvae were also fed leaves of Zizania aquatica, a native macrophyte that the skipper commonly uses as a host plant. Larval survival and duration, pupal weight, and pupation time were compared for P. viator feeding on leaf tissue and R. lutosa feeding on rhizomes of either native or introduced plants. We also tested an artificial diet supplemented with P. australis rhizome powder as a potential food for rearing other stalk and rhizome boring Lepidoptera. In experiments using excised plant tissues, some individuals of both species fed and developed to the pupal stage on native and introduced plants, but overall, larval survival rates were low. Plant species/haplotype identity did not cause strong differences in larval survival for either species. However, P. viator larvae only pupated when feeding on native plants (Zizania aquatica and native P. australis haplotypes), whereas R. lutosa successfully pupated on both native and introduced P. australis. Although larval survival was low, 100% of P. viator and 95% of R. lutosa that reached the pupal stage emerged as adults. Rhizedra lutosa larvae fed an artificial diet supplemented with P. australis rhizome powder had significantly greater survival and pupal weights, and shorter pupation times than larvae fed rhizomes only. Several specialist Lepidopteran species are being considered for approval as biological control agents for the non-native P. australis haplotype, and the convenience and increased larval performance make this artificial diet a good alternative for rearing organisms

Accounting Information, Disclosure, and the Cost of Capital

In this paper we examine whether and how accounting information about a firm manifests in its cost of capital, despite the forces of diversification. We build a model that is consistent with the Capital Asset Pricing Model and explicitly allows for multiple securities whose cash flows are correlated. We demonstrate that the quality of accounting information can influence the cost of capital, both directly and indirectly. The direct effect occurs because higher quality disclosures affect the firm\u27s assessed covariances with other firms\u27 cash flows, which is nondiversifiable. The indirect effect occurs because higher quality disclosures affect a firm\u27s real decisions, which likely changes the firm\u27s ratio of the expected future cash flows to the covariance of these cash flows with the sum of all the cash flows in the market. We show that this effect can go in either direction, but also derive conditions under which an increase in information quality leads to an unambiguous decline in the cost of capital

Information Asymmetry, Information Precision, and the Cost of Capital

This paper examines the relation between information differences across investors (i.e., information asymmetry) and the cost of capital and establishes that with perfect competition information asymmetry makes no difference. Instead, a firm’s cost of capital is governed solely by the average precision of investors’ information. With imperfect competition, however, information asymmetry affects the cost of capital even after controlling for investors’ average precision. In other words, the capital market’s degree of competition plays a critical role for the relation between information asymmetry and the cost of capital. This point is important to empirical research in finance and accounting

The Structure and Performance Consequences of Equity Grants to Employees of New Economy Firms

The paper examines the determinants and performance consequences of equity grants to senior-level executives, lower-level managers, and non-exempt employees of “new economy” firms. We find that the determinants of equity grants are significantly different in new versus old economy firms. We also find that employee retention objectives, which new economy firms rank as the most important goal of their equity grant programs, have a significant impact on new hire grants, but not subsequent grants. Our exploratory performance tests indicate that lower than expected grants and/or existing holdings of options are associated with poorer performance in subsequent years

Information Asymmetry, Information Precision, and the Cost of Capital

The consequences of information differences across investors in capital markets are still much debated. This paper examines the relation between information differences across investors and the cost of capital, and makes three points. First, in models of perfect competition, information differences across investors affect a firm's cost of capital through investors' average information precision, and not information asymmetry per se. Second, the average precision effect of information that is heterogeneously distributed across investors is unlikely to diversify away when there exist many firms whose cash flows covary. Thus, better disclosure can reduce a firm's cost of capital. Third, the precision effect does not give rise to a separate information-risk factor. These points are important to empirical research in accounting and finance, as well as to regulators who debate future disclosure requirements and the consequences of prior requirements such as Regulation Fair Disclosure.

Cancers of Unknown Primary

Cancers of unknown primary (CUP) are a heterogeneous group of histologically proven metastatic tumors whose primary site can\u27t be determined after a standard diagnostic and pathologic work-up. This chapter in Cancer Concepts: A Guidebook for the Non-Oncologist presents provides an overview of cancers of unknown primary, including initial evaluation and principles of treatment.https://escholarship.umassmed.edu/cancer_concepts/1016/thumbnail.jp

Composition of Pyromorphites from Broken Hill, New ·South Wales

Twenty eight specimens of pyromorphite from the oxidised zone of the Broken Hill orebody, New South Wales have been analysed using EPMA methods. Material was selected to represent all of the varieties of pyromorphite which have been described by earlier workers as occurring in the deposit. Aside from minor Ca2+ substitution for Pb2+ and occasionally YO/" for PO/", all specimens examined proved to be either pure end-member pyromorphite or arsenian pyromorphite with a maximum arsenate content corresponding to pyr2 . 1mim0 . 9 • In one specimen phosphate-arsenate zoning is evident; minor vanadate is present in the more arsenian material. Calcium-lead zoning has been detected in a pale grey-coloured specimen. These zoning patterns indicate chemical variations in aqueous solution during crystal growth. The arsenate contents appear to be directly related to the original distribution of the primary arsenides and arsenic-bearing sulfosalts. The compositions have been related to those of the solutions from which they crystallised. Apatite is a major accessory in the primary ore and this would provide the requisite phosphate ions

Chiasma

Newspaper reporting on events at the Boston University School of Medicine in the 1960s

Antenna Near-Field Probe Station Scanner

A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described

Probe Station and Near-Field Scanner for Testing Antennas

A facility that includes a probe station and a scanning open-ended waveguide probe for measuring near electromagnetic fields has been added to Glenn Research Center's suite of antenna-testing facilities, at a small fraction of the cost of the other facilities. This facility is designed specifically for nondestructive characterization of the radiation patterns of miniaturized microwave antennas fabricated on semiconductor and dielectric wafer substrates, including active antennas that are difficult to test in traditional antenna-testing ranges because of fragility, smallness, or severity of DC-bias or test-fixture requirements. By virtue of the simple fact that a greater fraction of radiated power can be captured in a near-field measurement than in a conventional far-field measurement, this near-field facility is convenient for testing miniaturized antennas with low gains