Analysis of the Antigenic Relationships Among Trichomonas,Histomonas, Dientamoeba and Entamoeba III. Immunoelectrophoresis Technics*

Antigens prepared from Trichomonas gallinae, Histomonas meleagridis, Dientamoeba fragilis, Entamoeba invodens and Entamoeba histolytica were separated by electrophoresis in agar gels and reacted with antisera prepared in rabbits against each of the 5 species. The most numerous and strongest precipitin lines were obtained from reactions between the homologous antigens and antisera. Direct and cross-absorption reaction methods were employed with each antiserum and the various antigens to ascertain quantitatively the immunologic relationships among the several organisms. Trichomonas shared many common antigens with Histomonas, fewer with Dientamoeba and none with either species of Entamoeba. Histomonas was more closely related antigenically to Dientamoeba than to Trichomonas. The histomonad had only a few weakly cross-reacting antigens in common with the 2 Entamoeba species. Dientamoeba shared the most common antigens with Histomonas, fewer with Trichomonas and the fewest with Entamoeba. Somewhat stronger cross-reactivity was obtained with anti-Dientamoeba serum and E. invadens than between this immune serum and E. histolytica. The 2 species of Entamoeba shared the largest number of common antigens with each other, and to a much lesser extent both species cross reacted with Dientamoeba. Anti-Entamoeba sera had only a few weak cross-reacting precipitins with Histomonas. No antigenic relationship was found between either species of Entamoeba and Trichomonas.     

Relationships among non-native plants, diversity of plants and butterflies, and adequacy of spatial sampling

Non-native invasive species are altering ecosystems in undesirable ways, often leading to biotic homogenization and rapid reduction of evolutionary potential. However, lack of money and time hampers attempts to monitor the outcome of restoration efforts. Hence, it is useful to determine whether relatively limited sampling can provide valid inferences about biological responses to pattern-based and process-based variables that are affected by restoration actions. In the Mojave Desert, invasion of salt-cedar ( Tamarix ramosissima ) has altered vegetational communities and some measures of faunal diversity. We tested whether six vegetation-based predictor variables affected species richness of butterflies in the Muddy River drainage (Nevada, USA). We also explored whether similar conclusions about relationships between vegetation and butterflies could have been obtained by using data from a subset of the 85 locations included in the study. We found that the effect of non-native plants on species richness of butterflies was negligible. Availability of nectar had the greatest independent explanatory power on species richness of butterflies, followed by species richness of plants. In comparison with the full data set, subsamples including 10, 25 and 50% of sites yielded similar conclusions. Our results suggest that relatively limited data sets may allow us to draw reliable inferences for adaptive management in the context of ecological restoration and rehabilitation.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 157–166.     

Effect of stinging nettle habitats on aphidophagous predators and parasitoids in wheat and green pea fields with special attention to the invader Harmonia axyridis Pallas (Coleoptera: Coccinellidae)

The relative occurrence and seasonal abundance of aphids and their natural enemies were visually assessed between May and July 2005–2006 in four types of habitats located in Gembloux (Namur province, Belgium): green pea, wheat and stinging nettle either planted in or naturally growing in woodland adjacent to these crops. Results showed that: (i) Acyrthosiphon pisum Harris, Sitobion avenae F. and Microlophium carnosum Buckton were the most common aphid species, respectively, on green pea, wheat and stinging nettle either in or near field crops; (ii) stinging nettle and field crops shared several important aphidophagous insect species such as the ladybird Coccinella septempunctata L., hoverfly Episyrphus balteatus De Geer and braconid wasp Aphidius ervi Haliday; (iii) the shared beneficial species were typically recorded earlier on stinging nettles than on crops; and (iv) the spatial occurrence of the invasive ladybird Harmonia axyridis Pallas was distinctly associated with stinging nettles, particularly in 2005. Stinging nettles and field crops partially coincide in time, enabling the movement of natural enemies among them. These findings suggest that the presence of stinging nettles in landscapes seems to enhance the local density of aphidophagous insect communities necessary for aphid biocontrol in field crops.     

The roles of Neogene geology and late Pleistocene lake levels in shaping the genetic structure of the Lahontan redside shiner Richardsonius egregius (Teleostei: Cyprinidae)

Shifting drainage patterns in western North America, shaped by geological activity and changing global climates, have influenced the evolution of many aquatic taxa. We investigated the role of late Pleistocene high stands in pluvial Lake Lahontan on the genetic structure of Richardsonius egregius, a minnow endemic to the Lahontan Basin of the western Great Basin. We used the mitochondrial cytochrome b gene to generate a phylogeny and assess intraspecific genetic diversity, to estimate divergence times between clades, and to evaluate whether gene flow currently occurs. The results obtained show that R. egregius exhibits genetic divergence between eastern and western Lahontan Basin populations. Divergence time estimates show that intraspecific genetic diversification began in the Pliocene or early Pleistocene, before the pluvial lake high stands associated with the last glacial maximum. These results imply that the fluctuating water levels in pluvial Lake Lahontan had a minimal effect on shaping the genetic architecture of R. egregius. Coalescent analyses using the immigration with migration model show that contemporary gene flow between eastern and western Lahontan Basin populations does not occur. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 163–176.     

Assessment of Canada Lynx Research and Conservation Needs in the Southern Range: Another Kick at the Cat

Abstract The ecology of Canada lynx (Lynx canadensis) and their main prey, snowshoe hares (Lepus americanus), is poorly understood in southern Canada and the contiguous United States compared to the boreal forest of Canada and Alaska, USA, where both species are well studied. However, given recent listing of lynx under the Endangered Species Act, accurate understanding of lynx and snowshoe hare ecology and conservation requirements in the United States is a high priority. We critically examined unchallenged perceptions and important research needs related to lynx and hare ecology and conservation at the southern extent of their range. Contrary to popular dogma, lynx do not require old-growth forest for denning, but further research on lynx and hare use of fragmented landscapes at lower latitudes is required. The contention that southern lynx are subject to higher interference or exploitative competition compared to their northern counterparts remains without strong empirical support. Lynx rely more on red squirrels (Tamiasciurus hudsonicus) and possibly other alternate prey at lower latitudes, but hares are the predominant food type for lynx across their range. Southern lynx and hare populations do not exhibit periodic cyclicity, but harvest statistics suggest that lynx abundance in the southern range is highly variable, implying that numerical fluctuations likely are fueled by immigration from Canada. Southern lynx population viability in the absence of ingress is suspect and thus maintaining connectivity with northern areas of occupancy should be a priority. Successful conservation of lynx populations in the contiguous United States will require 1) improved understanding of lynx population and habitat ecology at lower latitudes, 2) protection and management of large tracts of lynx and snowshoe hare habitat, and 3) ensured connectivity between lynx populations at the core and periphery of the species' range. However, in light of the numerous challenges facing conservation of populations of many species at their southern distributional limit, the long-term prognosis for lynx in the southern range currently is uncertain.     

The Health and Nutrition of a Medieval Nubian Population

Human remains from two cemeteries at Kulubnarti in Sudanese Nubia present an ideal opportunity to assess the biological impact of political and economic change. Remains from the early cemetery come from Nubia's medieval period, characterized by political unification and important achievements in art and architecture. Remains from the second cemetery come from the later emergent feudal age, characterized by regional isolation and return to a subsistence economy. Patterns of mortality, growth, development, nutrition, and disease revealed by the remains converge on one conclusion: the transformation from the medieval to the feudal age at Kulubnarti witnessed an improvement in human health and survival.