Crawling Water Beetles of Wisconsin (Coleoptera: Haliplidae)

(excerpt) Haliplidae are smail water beetles, less than 5 mm long, that frequently occur in abundance in ponds, marshes, sloughs, and swamps and also along the margins of slow streams or lakes where there is not severe wave action. Adults are readily recognized by their yelloa- to orange ground color with black maculations on the elytra and sometimes on the head and pronotum (Figs. 1,3,4). They have a distinctive shape, being broadest at the basss of the elytra and tapered toward the posterior end. The metacoxae are covered by dis~ctive plates that are unique among water beetles (Fig. 2). The tarsi and tibiae of the adults are modified for swimming, and the beetles can swim quite well, although they mostly crawl among the vegetation. Adults and larvae are found among vegetation upon which they feed, filamentous algae being the primary source of food for most species, but detrims and animal material may form a portion of the diet in some species. In Wisconsin most species probably have a one-year life cycle and overwinter as adults. Eggs are laid during spring and early summer, usually in or upon algae. There are three larval instars, and pupation takes place in moist soil above the water line. Larvae have been derrihd for only a few species, so identification is based upon adult characteristics

A Perspective on the Use of Storable Propellants for Future Space Vehicle Propulsion

Propulsion system configurations for future NASA and DOD space initiatives are driven by the continually emerging new mission requirements. These initiatives cover an extremely wide range of mission scenarios, from unmanned planetary programs, to manned lunar and planetary programs, to earth-oriented (Mission to Planet Earth) programs, and they are in addition to existing and future requirements for near-earth missions such as to geosynchronous earth orbit (GEO). Increasing space transportation costs, and anticipated high costs associated with space-basing of future vehicles, necessitate consideration of cost-effective and easily maintainable configurations which maximize the use of existing technologies and assets, and use budgetary resources effectively. System design considerations associated with the use of storable propellants to fill these needs are presented. Comparisons in areas such as complexity, performance, flexibility, maintainability, and technology status are made for earth and space storable propellants, including nitrogen tetroxide/monomethylhydrazine and LOX/monomethylhydrazine

Constructing two-sided simultaneous confidence intervals for multinomial proportions for small counts in a large number of cells

Confidence intervals for multinomial proportions are often constructed using large-sample methods that rely on expected cell counts of 5 or greater. In situations that give rise to a large number of categories, the cell counts may not be of adequate size to ensure the appropriate overall coverage probability and alternative methods of construction have been proposed. Sison and Glaz (1995) developed a method of constructing two-sided confidence intervals for multinomial proportions that is based on the doubly truncated Poisson distribution and their method performs well when the cell counts are fairly equally dispersed over a large number of categories. In fact, the Sison and Glaz (1995) intervals appear to outperform other methods of simultaneous construction in terms of coverage probabilities and interval length in these situations. To make the method available to researchers, we have developed a SAS macro to construct the intervals proposed by Sison and Glaz (1995).

Disclosure of Finance Charges: A Rationale

One wonders whether in all of the talk generated about disclosure in the past few years the purposes of disclosing finance charges to consumers have not been somewhat obscured. This article is an attempt to examine the subject of disclosure from the standpoint of the function it performs in consumer credit transactions. We shall discuss the various methods of computing finance charges in the different segments of the finance industry, the functions of disclosure of finance charges and the feasibility of using different computational methods in each category of consumer transactions. The problems involved in requiring the disclosure of finance charges are not as simple as one is sometimes led to believe. Each side of the controversy has good arguments to support its view; neither side is the exclusive repository of justice and morality. The problem of required disclosure has long been debated and is ripe for resolution. It is our hope that this article will succeed in pointing out some of the factors that should be considered in a compromise legislative solution of this thorny problem

Bostonia. Volume 16

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Digital demodulator-correlator

An apparatus for demodulation and correlation of a code modulated 10 MHz signal is presented. The apparatus is comprised of a sample and hold analog-to-digital converter synchronized by a frequency coherent 40 MHz pulse to obtain four evenly spaced samples of each of the signal. Each sample is added or subtracted to or from one of four accumulators to or from the separate sums. The correlation functions are then computed. As a further feature of the invention, multipliers are each multiplied by a squarewave chopper signal having a period that is long relative to the period of the received signal to foreclose contamination of the received signal by leakage from either of the other two terms of the multipliers

Bostonia. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Comparisons and Trends in White-tailed Deer, Odocoileus virginianus, Body Fat in Northeastern Minnesota, 1974-1990

The relationships among locations of body fats have not been thoroughly examined in White-tailed Deer (Odocoileus virginianus). We measured bone marrow fat (n = 2995), back fat (n = 1018), kidney fat (n = 2076), and xiphoid fat (n = 1246) levels of White-tailed Deer kills from Cook and Lake counties in northeastern Minnesota during 1974-1990. For each dead deer we determined age, sex, date, and causes of mortality. All of the fat measures were correlated to varying degrees. Generally all fat measurements peaked in late autumn and subsequently began declining and reached their lowest levels in May. Fat content was negatively correlated with winter severity. Causes of mortality included predation, poaching, accidental, unknown, and auto-collisions. Predated animals had lower bone marrow (-7.42 ± 3.92) and 0.165 ± 2.30 times lower back fat and had higher amounts of kidney fat than those killed by vehicles (0.86 ± 0.43)

Statewide Survey of Skid Resistances of Pavements [Dec. 1976]

Since 1969, when a research-type, skid-test trailer was acquired, U.S. routes were surveyed in 1970 and 1971, and the interstate and toll road systems were surveyed in 1971. The data were used for research purposes and have been reported. The interstate and toll road systems were surveyed again for research purposes in 1974. Since October 1974, surveys have been performed under a highway safety project grant. All primary and principal secondary roads, involving 4,612 miles (7425 km), were surveyed in 1975. The 1974 and 1975 surveys, data reported herein, represented 25 percent of the mileage of rural, state-maintained roads in Kentucky and 75 percent of all traffic on rural, state-maintained roads. A second skid tester, survey-type, was acquired in April 1976; and survey-testing of major, rural collector roads continued during 1976. About 2 percent of the interstate mileage, about 19 percent of the primary mileage, and about 16 percent of the secondary mileage surveyed may be considered slippery. A small percentage of both state primary (3.7 percent) and state secondary (2.5 percent) roads were classified as very slippery. These pavement sections in particular should be flagged for deslicking. Trends and analysis of accidents on wet pavements from 1969 through 1975 are reported. Description and evaluation of the resurfacing program from the standpoint of deslicking of pavements is also presented. In addition, results of high-accident location testing and evaluation are included

Bostonia. Volume 14

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs