Enhanced Offset Averaging Technique for Flash ADC Design

This paper presents a new combined AC/DC-coupled output averaging technique for input amplifier design of flash analog-to-digital converters (ADC). The new offset averaging design technique takes full advantage of traditional DC-coupled resistance averaging and AC-coupled capacitance averaging techniques to minimize offset-induced ADC nonlinearities. Circuit analysis allows selection of optimum resistance and capacitance averaging factors to achieve maximum offset reduction in ADC designs. The new averaging...     

Checklist of Tiger Beetles from Idaho (Coleoptera: Cicindelidae)

Sixteen species of Tiger Beetles are listed for Idaho, along with the counties of occurrence for each species. Three species are placed in a checklist of Idaho species for the first time: Cicindela depressula depressula Casey, Cicindela parowana wallisi Calder, and Cicindela decemnotata decemnotata Say.         

Growth of Dipodomys ordii (Rodentia: Heteromyidae)

Growth rates were determined for laboratory - reared Dipodomys ordii pallidus Durrant & Setzer. Instantaneous growth rates were used to express increase of body weight, total length, tail length, ear length and hind foot length as rates between times of measurements and the instantaneous percentage of maximum size. Data were analyzed for growth periods of 1 – 3, 4 – 15, 16 – 29 and 30 – 70 days. All five parameters provided significant correlations of growth with age during all growth periods. Even though all of the growth parameters correlate with age, these parameters cannot be reliably used to predict age.     

Changes in riparian vegetation along the Colorado River and Rio Grande, Colorado

Changes in vegetation including area occupied, canopy cover, and maturity class of cottonwoods ( Populus spp.) within lower-elevation zones of the Colorado River and Rio Grande in Colorado were monitored over 25- and 27-year intervals, respectively, using photo-interpretative methods. Estimated loss of cottonwoods along the Colorado River was 2ha/km (-17.5%), and remaining stands had become more open and older. Cottonwoods along the Rio Grande increased 1.6 ha/km (9.3%) with minor canopy cover and maturity class changes. Area occupied by shrubs and river channel changed little along the Colorado River, but declined along the Rio Grande. Loss of hay meadow occurred along both rivers, whereas developed land increased along the Colorado River and farmland increased along the Rio Grande. Wildlife habitats along the Colorado deteriorated much more rapidly than those along the Rio Grande during monitored intervals.     

Life history variation in recently established populations of western mosquitofish ( Gambusia affinis )

We report life history characteristics for 4 recently established populations of western mosquitofish ( Gambusia affinis ). Mosquitofish from thermally stable habitats, Bonham and Garrett, were characterized by maturity at large sizes, high fat reserves, and large embryos. In contrast, females from a thermally unstable habitat, Wabuska, matured at small sizes and had low fat reserves and small embryos. Females from Parker, a site with no appreciable thermal input, matured at intermediate sizes and had low fat reserves as well as large embryos. These populations shared a common ancestor in 1937; therefore, these results suggest either phenotypic plasticity or rapid evolution.     

Spotted knapweed distribution in stock camps and trails of the Selway-Bitterroot Wilderness

This article documents spotted knapweed ( Centaurea maculosa Lam.) in 30 campsites and along 5 trails in the Selway-Bitterroot Wilderness and assesses the role of disturbance and environmental factors in controlling infestation. Spotted knapweed was present in only 6 of 30 surveyed campsites and limited portions of all 5 trails that were sampled. All spotted knapweed in camps was below 1700 m elevation, in open canopy, and in areas with an opportunity class disturbance ranking of 3 or 4. Overall disturbance levels measured using U.S. Forest Service Site Impact Worksheets (SIWs) did not help predict occurrence of spotted knapweed, although bare mineral soil, vegetation loss, and development variables of SIWs provide some explanation of spotted knapweed presence or absence. There was no significant difference in knapweed frequency between areas used predominantly by horses and those use by humans within camps. Over 95% of spotted knapweed along trails was found within 0.5 km of the trailhead, occurred within 4.6 m of the trail, and had low reproductive potential. If the Bitterroot portion of the Selway-Bitterroot Wilderness is representative of forested wilderness areas in the Northern Rockies, then the perceived threat of spotted knapweed to wilderness areas may subsequently exceed the actual danger in many instances. Study findings indicated that managers should conduct surveys before initiating costly control measures in wilderness areas, that eradication may be a viable alternative when spotted knapweed numbers are this low, and that regulations promoting minimum-impact camping should reduce spotted knapweed infestation.     

Selection of ants by the American black bear ( Ursus americanus )

We examined selection of ants as food by black bears ( Ursus americanus ) in Utah by comparing the genera of ants we sampled from study plots in 5 vegetation types with those found in bear scats. In the plots we found 641 ant colonies representing 18 genera. Five genera comprised 85% of all colonies sampled: Formica, Lasius, Camponotus, Tapinoma, and Myrmica . Thirteen genera were found in scats, but 99% were composed of the same 5 listed above. Limited utilization of some ant genera by black bears may reflect body size, colony size, nest type, and presence or absence of a functional sting. Fifty-three percent of all ant colonies in sample plots were found under rocks. Energy values of ants ranged from 4.9 to 6.2 cal · g -1 dry weight. Pupae of Formica and Camponotus contained slightly more fat than respective workers, but the relationship was reversed for Lasius . Pupal cases were found in 33% of the scats, and bears may prefer ant brood because they are more digestible than adults and lack mechanisms of defense. Ants are a predictable and ubiquitous food source for black bears.     

Physicalism,realization, and structure

In the philosophy of mind and psychology, a central question since the 1960s has been that of how to give a philosophically adequate formulation of mind-body physicalism. A large quantity of work on the topic has been done in the interim. There have been, and continue to be, extensive discussions of the ideas of physicalism, identity, functionalism, realization, and constitution. My aim in this paper is a modest one: it is to get clearer about these ideas and some of their interrelations. After providing some background and history, I shall focus on two related topics: the distinction between a functional property and a structural one and the dispute over whether a realization account of the mental-physical relation provides a better physicalist account than a constitutional account.