Effects of forest fuel smoke on dwarf mistletoe seed germination

Seeds of three species of dwarf mistletoe, Arceuthobium americanum Nutt. Ex Engelm., A. cyanocarpum Coulter & Nelson, and A. vaginatum subsp. cryptopodum (Engelm.) Hawksw. & Wiens, were exposed to smoke from burning forest fuels. Premeasured amounts of coniferous needles and branch wood were burned in a small incinerator with smoke passing through a closed chamber containing the seeds. Following three different smoke treatments and one high-temperature treatment, tests were conducted to evaluate the effects of these treatments on seed germination. Germination was inhibited for all species when the seeds were exposed to smoke for 60 minutes or longer. Seeds of A. americanum were unaffected by exposures to smoke from drier fuels. The percentage of germinating seeds of A. cyanocarpum and A. vaginatum showed little effect from exposures of up to 30 minutes.     

Note on food habits of the Screech Owl and the Burrowing Owl of southeastern Oregon

Diets of the Common Screech Owl ( Otus asio ) and Burrowing Owl ( Athene cunicularia ) from the Great Basin, Malheur County, southeastern Oregon, were studied. Although there was considerable overlap in the diets of these owls, there were differences related to habitat use.     

Short-term effects of logging on red-backed voles and deer mice

Clearcutting and selective logging effects on red-backed voles ( Clethrionomys gapperi ) and deer mice ( Peromyscus maniculatus ) were studied (September–November, 1975; June–October, 1976) in Bridger-Teton National Forest, Wyoming. Five selective cuts (total 137 ha) removed 57 percent (range 34–74 percent) of the trees. One clearcut (9.6 ha) eliminate 84 percent of the trees. Soils remained mesic in selective cuts, but became xeric in the clearcut. Snap-trapping indicated that voles were most abundant on the unlogged and selectively cut mesic sites (76 percent of 408 captures), whereas deer mice were more common on the xeric clearcut (80 percent of 60 captures). Species composition remained unchanged on selective cuts following logging (77 percent voles of 256 captures), but changed from predominantly voles to mostly deer mice (80 percent of 60 captures) in the clearcut. Intraspecific age and sex ratios, litter sizes, and morphological measurements were compared between logged and unlogged areas.     

Helminth parasites of cats and dogs from central Utah

A survey of the helminth parasites of 100 stray cats and 50 dogs was conducted. Each host was euthanized, and the internal organs were excised and examined for parasites. Helminths identified from cats included the tapeworms Dipylidium caninum and Hydatigera taeniaformis, and the nematodes Physaloptera sp. and Toxocara mystax. Two species of coccidia, Isospora felis and I. rivolta, and one ectoparasitic mite, Cheyletiella parasitivorax, were also recovered from cats during sugar flotation of the feces. Helminths identified from dogs included the tapeworms D. caninum, Taenia hydatigena, T. krabbei, and T. pisiformis, and the nematodes Filaroides milksi, Toxascaris leonina, and Toxocara canis. Of those parasites collected, D. caninum, T. canis, and T. mystax are known to cause accidental infection in humans and could represent potential health hazards in this region.     

Distribution and relative abundance of fish in Ruth Reservoir, California, in relation to environmental variables

The fish population of Ruth Reservoir, California, was sampled every two weeks with variable mesh gill nets from May 1974 through May 1975. Fish were captured in the following order of numerical abundance: Humboldt sucker ( Catostomus humboldtianus ), golden shiner ( Notemigonus crysoleucus ), brown bullhead ( Ictalurus nebulosus ), white catfish ( I. catus ), rainbow trout ( Salmo gairdneri ), and largemouth bass ( Micropterus salmoides ). The three most abundant species made up about 95 percent of total numbers and weight. All species exhibited a similar cyclic temporal availability pattern: catch rates increased to a maximum during summer and fall and decreased during winter and spring. Environmental variables with the most pronounced relationships to fish catches were temperature (direct) and turbidity (inverse).     

Field identification of Myotis yumanensis and Myotis lucifugus: a morphological evaluation

Myotis lucifigus and Myotis yumanensis are 2 species of bats subject to potentially high rates of misidentification because they are often difficult to differentiate in the hand under field conditions. We tested the utility of a suite of external morphological characteristics frequently cited in regional keys to differentiate the 2 species in the field. Forearm length, dorsal pelage sheen, ear color, and forehead slope were examined from 101 bats captured in central Oregon during 2002–2003. Post hoc genetic analysis was performed on tissue samples collected from the 101 bats to confirm identification. Forearm lengths overlapped considerably between species. Only 18% of M. yumanensis and 17% of M. lucifugus were correctly identified with probability ≥95% using forearm length alone. Pelage sheen, ear color, and forehead slope successfully identified 96%, 82%, and 77% of individual bats, respectively. When forearm length was considered together with other traits, identification rates ranged from 92% to 20%. Ability to correctly identify M. yumanensis was 2–6 times greater than for M. lucifugus. Pelage sheen was useful in our study; however, using this character required a subjective decision from the observer, and the result often contradicted other characters for species identification stated in regional keys. For these reasons, we recommend that morphological features be used judiciously and only as supportive criteria for field identification in combination with voucher echolocation calls and genetic confirmation.     

Brood-rearing habitat use by Rio Grande Wild Turkeys in Oregon

Wild turkey ( Meleagris gallopavo ) brood-rearing sites have been described for portions of their range, but brood-rearing habitat use and characteristics of brood-rearing sites used by Rio Grande Wild Turkeys ( M. g. intermedia ) in the Pacific Northwest were unknown. We described cover types at 362 brood-rearing sites and measured habitat characteristics at 64 of these sites used by a recently established Rio Grande Wild Turkey population in southwestern Oregon during May-September 1989 and 1990. Hens with broods used 9 of 10 available cover types. Meadows, mixed hardwood/conifer woodlands, and savannas were used more often than expected (47% of observations, P ≤ 0.05). Broods used mature mixed conifer and dense sapling/pole mixed conifer cover types less than expected and did not use brush-fields. Many brood-rearing sites were characterized by a parklike appearance. Understory vegetation averaged P ≤ 0.05). We suggest that land managers maintain mixed hardwood/conifer woodland and savanna cover types adjacent to meadows on south slopes to provide brood-rearing habitat for Rio Grande Wild Turkeys in southwestern Oregon.     

Is Leibnizian Calculus Embeddable in First Order Logic?

To explore the extent of embeddability of Leibnizian infinitesimal calculus in first-order logic (FOL) and modern frameworks, we propose to set aside ontological issues and focus on procedural questions. This would enable an account of Leibnizian procedures in a framework limited to FOL with a small number of additional ingredients such as the relation of infinite proximity. If, as we argue here, first order logic is indeed suitable for developing modern proxies for the inferential moves found in Leibnizian infinitesimal calculus, then modern infinitesimal frameworks are more appropriate to interpreting Leibnizian infinitesimal calculus than modern Weierstrassian ones.     

Realism on the rocks: Novel success and James Hutton's theory of the earth

In this paper, I introduce a new historical case study into the scientific realism debate. During the late-eighteenth century, the Scottish natural philosopher James Hutton made two important successful novel predictions. The first concerned granitic veins intruding from granite masses into strata. The second concerned what geologists now term “angular unconformities”: older sections of strata overlain by younger sections, the two resting at different angles, the former typically more inclined than the latter. These predictions, I argue, are potentially problematic for selective scientific realism in that constituents of Hutton's theory that would not be considered even approximately true today played various roles in generating them. The aim here is not to provide a full philosophical analysis but to introduce the case into the debate by detailing the history and showing why, at least prima facie, it presents a problem for selective realism. First, I explicate Hutton's theory. I then give an account of Hutton's predictions and their confirmations. Next, I explain why these predictions are relevant to the realism debate. Finally, I consider which constituents of Hutton's theory are, according to current beliefs, true (or approximately true), which are not (even approximately) true, and which were responsible for these successes.     

Holographic three-dimensional telepresence using large-area photorefractive polymer

Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50?Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.