Small Mammal Responses to Fine Woody Debris and Forest Fuel Reduction in Southwest Oregon

Abstract: Despite its importance for wildlife, most forests in the Pacific Northwest contain low volumes of large downed wood compared to fine woody debris (FWD). We used a replicated experiment to compare short-term responses of deer mice (Peromyscus maniculatus) and western red-backed voles (Clethrionomys californicus) among 3 arrangements of FWD: piled, lopped and scattered, and pile burning, a commonly used method of fuel reduction in commercial Douglas fir (Pseudotsuga menziesii) forests in southwest Oregon, USA. We assessed habitat use, density, and survival of mice and voles during 2 consecutive summers (Jun—Aug 1999 and 2000). Both mice and voles used FWD cover disproportionately from its availability, and they differed in their responses to specific FWD arrangements. Mice used piled FWD (proportional use = 37.0%, 90% CI = 33.0–44.0) 43% more than expected (26.0). Number of mice captured (x̄ = 1.9 mice, 90% CI = 1.5–2.5) and index of home range size (x̄ = 4.8 m, 90% CI = 0.7–8.9) at individual FWD piles decreased up to 16% and increased up to 50%, respectively, for each 1-m increase in distance from piles. Voles used all FWD cover classes in proportion to availability, but number of voles captured increased slightly (x̄ = 0.016 voles/m, 90% CI = 0.001–0.031) for each 1-m increase in distance from piles. Piled FWD had no discernable effect on population density and apparent survival of mice, but analyses had low power (0.25, 0.67). Our results suggest that piling FWD would benefit deer mice, whereas lopped and scattered FWD might benefit voles. Thus, a combination of methods to reduce fire risk should be considered to accommodate multiple small mammal species. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):625–632; 2008)     

"Our Beer": Ethnographic Brands in Postsocialist Georgia

Although Georgia is known for its wines, industrial production of beer far outstrips industrial wine production for local markets: wine consumption occurs in ritual contexts in which new wine, typically purchased from peasant producers, is preferred; bottled, aged wines are primarily for exports. Beer, therefore, is a key area in which industrial production for indigenous consumers has been elaborated. Such goods are packaged and presented as being both ecologically "pure" and following "traditional" methods, often referencing "ethnographic" materials about traditional life in brand images, even as they proclaim their reliance on Western technologies.     

Carbohydrate and Amino Acid Analyses of Giardia muris Cysts

ABSTRACT. Intact Giardia muris cysts were subjected to consecutive chloroform/methanol and 2% sodium dodecyl sulfate (SDS) extractions, and to amyloglucosidase treatment. The SDS-insoluble, amyloglucosidase-fast cyst walls (ACW) were further incubated with chymotrypsin, trypsin, papain, or pronase. Low voltage scanning electron microscopy revealed no discernible change in the ultrastructure of the filamentous layer of the cyst wall following any of these treatments. Affinity for cyst wall-specific monoclonal antibody (Meridian Diagnostics, Cincinnati. OH) was also retained after all treatments. Periodic acid-Schiff staining and gas chromatography/mass spectrometry (GC/MS) of intact and treated cyst hydrolysates showed a significant reduction in the amount of glucose associated with the cyst (72 nmoles/10⁶ intact cysts vs 1.9 nmoles/10⁶ ACW) as a result of amyloglucosidase treatment, indicating that glucose is stored with in Giardia as an SDS-insoluble polymer, Galactosamine was identified by GC/MS as the predominant sugar associated with both the ACW and the proteinase treated ACW (42 nmoles/10⁶ ACW). High performance liquid chromatographic analysis of amino acids from intact and treated cyst hydrolysates revealed a marked reduction, but not elimination, of detectable quantities of identifiable amino acid residues (255 nmoles/10⁶ intact cysts vs 6.8 nmoles/10⁶ proteinase treated ACW). These results suggest that the filamentous layer of the cyst wall is primarily a carbohydrate peptide complex.     

The phylogeny of the Rhinocerotoidea (Mammalia, Perissodactyla)

A new phylogeny of the Superfamily Rhinocerotoidea is proposed, based upon an analysis of shared derived characters of the skull, teeth and skeleton. Hyrachyus is considered the primitive sister-taxon of the three rhinocerotoid families (Amynodontidae, Hyracodontidae, Rhinocerotidae), and the amynodonts appear to be the sister-group of hyracodonts and rhinocerotids. The relationships of primitive hyracodonts and rhinocerotids are clarified. Menoceras and Pleuroceras (new Subfamily Menoceratinae) are removed from the Diceratheriinae, since they appear to be more closely related to higher rhinoceroses than they are to Diceratherium. Of the three major monophyletic groups of higher rhinocerotids (aceratherines, teleoceratines and rhinocerotines), the last two groups are more closely related to each other than either is to aceratherines. Toxotherium and Schizotheroides are tentatively removed from the Rhinocerotoidea and placed in the Lophiodontidae.     

Activation of Tyrosinase Reduces the Cytotoxic Effects of the Superoxide Anion in B16 Mouse Melanoma Cells

Tyrosinase may protect against oxidative stress by using the superoxide anion (O^?₂) in the production of melanin. We have examined this by comparing its cytotoxic effects in B16/F10 and B16/F10-differential deficient (-DD) mouse melanoma cells that express high and low levels of tyrosinase activity respectively. Xanthine oxidase (XO) was used to generate O^?₂ and cytotoxicity assessed by measuring cell survival. XO increased O^?₂ concentrations and 3 h later dose related decreases in cell survival were seen. F10 cells were more resistant to these cytotoxic effects than the F10-DD cells. [Nle⁴,DPhe⁷]MSH increased tyrosinase activity and melanin content, reduced O^?₂ concentration and increased the resistance of F10 cells to the cytotoxic effects of O^?₂. No such effects were seen in F10-DD cells. The effect of [Nle⁴,DPhe⁷]MSH on the resistance of the F10 cells was time-dependent and noticeable when tyrosinase activity but not melanin was increased. This suggests that it was the activation of tyrosinase rather than the increase in the melanin that provided the protection against O^?₂. In support of this, inhibition of tyrosinase with phenylthiocarbamide reduced the increased resistance induced by [Nle⁴,DPhe⁷]MSH. Moreover, although melanin was capable of scavenging O^?₂ it had little effect at concentrations comparable to those in the activated F10 cells. XO also increased the melanin content of F10 but not F10-DD cells. We conclude that tyrosinase is able to utilise O^?₂ to produce melanin and this provides pigment cells with a unique anti-oxidant mechanism.