Concern over an apparent paucity of recent porcupine (Erithizon dorsatum) observations in Arizona, prompted us to replicate Walter P. Taylor's (1935) letter requesting information from U. S. Forest Service and other government agency field personnel on the animal's status. On the basis of 162 reports of >314 porcupine observations we concluded that porcupines are thinly and unevenly distributed throughout the state with animals reliably sighted in select habitats near prairie dog towns, in certain suburban settings, and on the North Kaibab Plateau. We attribute this general scarcity to predation by mountain lions (Puma concolor) and possibly black bears (Ursus americanus), and agree with Taylor that predator control efforts resulting is a depressed lion population is the most likely explanation for the high number of porcupines reported during the 1924–1934 period. Although the porcupine does not appear to be endangered, there is no evidence to suggest that lion numbers are decreasing and that porcupine numbers may again increase. Prédation, and perhaps increased mortality from night-time road kills, has made porcupines an unusual animal in most of Arizona.

The editor has retracted the article "Soil Compaction from Anthropogenic Activities in a Pinyon-Juniper (Pinus-juniperus) Woodland of Southern Nevada" based on the advice of the University of Nevada, Las Vegas because the author of this article, Simon A. Lei, has admitted to data fabrication of the material in this article. The author was a visiting lecturer in the Education college at the University of Nevada, Las Vegas at the time of the publication of this article and is no longer affiliated with the university. Authors are advised to no longer cite this article in any work.

Previous investigations have shown that certain strains of Lactobacillus species act as probiotic organisms within the gastrointestinal tract, helping to reduce colonization and infection with potential enteric pathogenic bacteria. Two potentially debilitating enteric pathogens, Entertoxigenic Escherichia coli and Enterohemorrhagic Escherichia coli, affect millions of people worldwide; however data on the effectiveness of probiotics for these strains of E. coli are minimal. In this study, we investigated the inhibitory effect of four Lactobacillus species against the growth of these two pathogenic strains of E. coli, as well as E. coli 25922, a typically non-pathogenic strain. The amount of growth inhibition was determined using both live lactobacilli cultures and supernatant obtained from actively growing lactobacilli broth cultures. The amount of growth inhibition of each E. coli strain varied depending on the method as well as the species of Lactobacillus used. Our experimental findings suggest that Entertoxigenic E. coli was strongly inhibited when exposed to live lactobacilli cells, but only partially inhibited when exposed to supernatant alone. In contrast, Enterohemorrhagic E. coli was equally inhibited by exposure to live cells or supernatant. More data are needed to determine the clinical implication of our experimental results.

A type of mastery learning was implemented in a sophomore-level genetics major course, using a Blackboard course shell and a premade course cartridge. Students were required to take a series of topical quizzes leading up to the hour lecture exam. However, students could take the quiz as many times as they wished, to earn the grade they wished. Each quiz was unique and drew 10 random questions from a pool. The grades for the mastery learning class were not statistically significantly different from a previous class in which homework assignments were given (P=0.28). However, students were given the option of answering an anonymous survey before each lecture exam; survey results were positive.

This study is a survey of the floristic composition of the Parker Creek watershed located in the Sierra Ancha Mountains of Arizona. This watershed includes ecological communities ranging from the Sonoran Upland Province to Rocky Mountain Montane Conifer Woodlands. The collections were conducted along designated routes within the lower and mid-upper reaches of the creek, including the inner canyon. A checklist was completed using both our new collections and several herbarium queries with the Southwestern Environmental Information Network (SEINet). This study reports the presence of 625 species, representing 335 genera and 94 families of vascular plants. The flora is predominantly comprised of angiosperms (ASU, Flowering plants), but also includes gymnosperms (conifers), lycophytes (club mosses), sphenophytes (horsetails) and pteridophytes (ASU, Ferns). A comparison to the nearby Sierra Ancha Wilderness, also located in the Sierra Ancha Mountains, revealed only 47% similarity to the Parker Creek watershed species.

Arizona ponderosa pine (Pinus ponderosa) forests have undergone dramatic changes since the late nineteenth century. Management practices such as fire exclusion have resulted in increased surface and tree crown fuel loads. Consequently, large and severe wildfires have been occurring more frequently in the ponderosa pine forests of Arizona. Furthermore, prescribed fire, both with and without tree thinning, is being applied to ponderosa pine forests to mitigate the risk of wildfire. Increasingly, normative plant species are spreading into burned forests regardless of fire type. In this article, we review recent literature on normative establishment in the post-fire plant community. Current research suggests an increasing risk of nonnative establishment is associated with increasing fire severity. Furthermore, wildfires seem more likely to promote nonnative species establishment than prescribed fires. The results are inconsistent, however, with some high-severity fires having few normatives and some prescribed fires strongly promoting invasion. Further research is needed to understand the mechanisms of invasion. In the 23 studies we examined, a total of 43 nonnative plant species were reported in post-fire communities. Of these, only three species were listed as noxious in Arizona: field bindweed (Convolvulus arvensis), Dalmatian toadflax (Linaria dalmatica), and Scotch cottonthistle (Onopordum acantium). Cheatgrass (Bromus tectorum), Kentucky bluegrass (Poa pratensis), and common mullein (Verbascum thapsus) were the most commonly observed species in burned areas, regardless of natural or anthropogenic ignition. Generally, nonnative presence increased after fire, but abundance of these species remained low (< 10% cover). Changes in nonnative populations reported in Arizona are consistent with those seen in ponderosa pine forests of other regions, with normatives tending to increase with increasing fire severity.

We propose a method to reconstruct paleotemperatures and to determine paleo-air mass source areas from deuterium isotopes (δD) extracted from fossil pollen originating from Lake Lisan (precursor to the Dead Sea), Jordan, and encompassing the period ∼ 23.3 – 13.8 cal kyr BP. Previous isotopic studies on fossil pollen depend on analyses of δ¹³C and δ¹⁸O values, which can vary significantly between and within plant species according to environmental setting and photosynthetic pathway. In addition, carbon chemicals introduced during acetylosis processing of pollen samples can contaminate carbon isotopes. In contrast, δD data from pollen are not affected by variation in organic carbon, and thus, do not require non-carbon bearing extraction techniques. We propose that pollen extraction can follow standard palynological methods of acid digestion and acetylosis. A paleotemperature curve is reconstructed by converting δD data from pollen to δ¹⁸O values using a localized meteoric water line and a standard temperature relationship between δD and δ¹⁸O. We estimate temperatures for the Late Glacial Maximum and the Bølling-Allerød warm period based on δD from fossil pollen. These results compare favorably with other temperature estimates for the Eastern Mediterranean region based on δ¹⁸O.