Nutrient content affecting Spodoptera frugiperda and Dalbulus maidis occurrence in corn

This work aims to study the effect of the nutrient contents in the leaves of corn on the incidence of Spodopterafrugiperda （Smith） （Lepidoptera： Noctuidae） and Dalbulus maidis （Delong ＆ Wolcott） （Homoptera： Cicadellidae）. The treatments were represented by unfertilized corn plants and corn plants fertilized with 250 kg of the formulation 4-14-8 （N- P-K） ＋ 100 kg of ammonium sulfate （AS）/ha and 500 kg of the formulation 4-14-8 （N-P-K） ＋200 kg of AS/ha, arranged in randomized blocks with four replicates. Attacks by S. frugiperda and D. maidis were higher as the nitrogen, sulfur, calcium and copper content in the leaves of corn increased. The effects of calcium and copper found in this study were not consistent with that of lower susceptibility associated with higher levels of these nutrients mentioned in the literature. We believe that there was a cumulative effect of the nutrients altogether, building up a nutritiously better vegetable which in turn had less reserve for defense, or that the content of both nutrients in the leaves were not high enough to induce such effects.     

Directional and stabilizing selection on wing size and shape in migrant and resident monarch butterflies, Danaus plexippus (L.), in Cuba

The majority of migrant monarchs (Danaus plexippus) from the eastern USA and south‐eastern Canada migrate to Mexico; however, some of them migrate to Cuba. Cuban migrants hatch in south‐east Canada and eastern USA, and then engage in a southern trip of 4000 km to this Caribbean island. In Cuba, these migrants encounter resident monarchs, which do not migrate, and instead move between plant patches looking for nectar, mating partners and host plants. These differences in flight behaviour between migrant and resident Cuban monarchs may have resulted in different selective pressures in the wing size and shape. Two modes of selection were tested, directional and stabilizing. In addition, wing condition was compared between these two groups. Monarchs were collected for 4 years in Cuba and classified as resident or migrant using two independent techniques: Thin‐layer chromatography and stable hydrogen and stable carbon isotope measurements. Wing size was measured and wing condition was rated in the butterflies. Fourier analysis and wing angular measurements were used to assess wing shape differences. Migrants have significantly longer wings than residents, thus supporting the action of directional selection on wing size. In addition, directional selection acts on wing shape; that is, migrant females differ significantly from resident females in their wing angles. However, the results do not support the action of stabilizing selection: there was no significant variance between migrant and resident monarchs in their wing size or shape. Also, migrant females and males differed in wing condition as a result of differences in flight behaviour. In conclusion, eastern North American monarchs offer a good opportunity to study the selective pressures of migration on wing morphology and how different migratory routes and behaviours are linked to wing morphology and condition. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92 , 605–616.     

Diagnosing and assessing uncertainties of terrestrial ecosystem models in a multimodel ensemble experiment: 1. Primary production

We conducted an ensemble modeling exercise using the Terrestrial Observation and Prediction System (TOPS) to evaluate sources of uncertainty in carbon flux estimates resulting from structural differences among ecosystem models. The experiment ran public‐domain versions of biome‐bgc, lpj, casa , and tops‐bgc over North America at 8 km resolution and for the period of 1982–2006. We developed the Hierarchical Framework for Diagnosing Ecosystem Models (HFDEM) to separate the simulated biogeochemistry into a cascade of three functional tiers and sequentially examine their characteristics in climate (temperature–precipitation) and other spaces. Analysis of the simulated annual gross primary production (GPP) in the climate domain indicates a general agreement among the models, all showing optimal GPP in regions where the relationship between annual average temperature (T, °C) and annual total precipitation (P, mm) is defined by P=50T+500. However, differences in simulated GPP are identified in magnitudes and distribution patterns. For forests, the GPP gradient along P=50T+500 ranges from ～50 g C yr^?1 m^?2 °C^?1 (casa ) to ～125 g C yr^?1 m^?2 °C^?1 (biome‐bgc ) in cold/temperate regions; for nonforests, the diversity among GPP distributions is even larger. Positive linear relationships are found between annual GPP and annual mean leaf area index (LAI) in all models. For biome‐bgc and lpj , such relationships lead to a positive feedback from LAI growth to GPP enhancement. Different approaches to constrain this feedback lead to different sensitivity of the models to disturbances such as fire, which contribute significantly to the diversity in GPP stated above. The ratios between independently simulated NPP and GPP are close to 50% on average; however, their distribution patterns vary significantly between models, reflecting the difficulties in estimating autotrophic respiration across various climate regimes. Although these results are drawn from our experiments with the tested model versions, the developed methodology has potential for other model exercises.     

Palynotaxonomy of Brazilian species of Polygala subgenus Hebeclada

This study used pollen morphology to address taxonomic controversies related to several species belonging to subgenus Hebeclada of the genus Polygala (Polygalaceae). According to the last traditionally accepted revision of this subgenus, it comprises 40 species. Nevertheless, a recent taxonomic treatment applying more comprehensive criteria reduced this number to only nine species. Our work focused on 15 traditionally accepted species that occur in Brazil, fourteen of which have been considered as only six species in this recent taxonomic study. Pollen grains from floral buds at pre‐anthesis were collected from herbarium specimens and analysed using both visible light and scanning electron microscopy. Most of the traditionally accepted species were distinguished by different combinations of several pollen‐related features, in particular colpi number (13 or 15), pollen size and shape, and endoaperture type (endocingulate or not) and arrangement (parallel or sinuous). The species accepted in the recent taxonomic treatment could not be discriminated by pollen characters. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 609–619.     

Species diversity and endemism in the Daphnia of Argentina: a genetic investigation

Although the temperate regions of South America are known to have a diverse daphniid fauna, there has been no genetic evaluation of the existing taxonomic system or of the affinities between the North and South American faunas. The present study analyses mitochondrial DNA sequences and allozyme variation to investigate species diversity in 176 Daphnia populations from Argentina. This work established the presence of at least 15 species in Argentina, six of which are either undescribed or are currently misidentified and two of which represent range extensions of North American taxa. Eleven of the Argentine species appear endemic to South America, while the remaining four also occur in North America. In the latter cases, the close genetic similarity between populations from North and South America indicates the recent exchange of propagules between the continents. While biological interactions and habitat availability have undoubtedly contributed to the observed species distributions, chance dispersal has apparently played a dominant role in structuring large-scale biogeographical patterns in this genus and probably in other passively-dispersed organisms.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 171−205.     

Bodo sp., a Free-Living Flagellate, Expresses Divergent Proteolytic Activities from the Closely Related Parasitic Trypanosomatids

ABSTRACT. We report the characterization of cell-associated and extracellular peptidases of Bodo sp., a free-living flagellate of the Bodonidae family, order Kinetoplastida, which is considered ancestral to the trypanosomatids. This bodonid isolate is phylogenetically related to Bodo caudatus and Bodo curvifilus . The proteolytic activity profiles of Bodo sp. were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing co-polymerized gelatin, casein, hemoglobin, or bovine serum albumin as substrates. The enzymatic complex degraded gelatin better in acidic pH, and under these conditions four proteolytic bands (120, 100, 90, and 75 kDa) were detected in the cellular or extracellular extracts. Two peptidases (250 and 200 kDa) were exclusively detected with the substrate casein. All these enzymes belong to the serine peptidase class, based on inhibition by aprotinin and phenylmethylsulfonyl fluoride. This is the first biochemical characterization of peptidases in a free-living Bodo sp., potentially providing insight into the physiology of these protozoa and the evolutionary importance of peptidases to the order Kinetoplastida as some of these enzymes are important virulence factors in pathogenic trypanosomatids.     

Autologous bone marrow–derived cells for venous leg ulcers treatment: a pilot study

Background

Chronic venous leg ulcers (VLUs) are a common problem in clinical practice and available treatments are not satisfactory. The use of adjuvant therapies in combination with lower limb compression may lead to improved healing rates. Chronic wounds are candidates for new strategies in the emergent field of regenerative medicine. Bone marrow–derived cells (BMDCs) contain cells and secrete cytokines known to participate in wound healing. Thus, BMDC therapy seems a logical strategy for the treatment of chronic wounds. Our objective was to evaluate feasibility, safety and initial clinical outcome of autologous BMDC therapy associated with standard treatment in patients with VLUs.

Tracing Genetic Lineages of Captive Desert Tortoises in Arizona

Abstract: We genotyped 180 captive desert tortoises (Gopherus agassizii) from Kingman (n = 45), Phoenix (n = 113), and Tucson (n = 22), Arizona, USA, to determine if the genetic lineage of captives is associated with that of wild tortoises in the local area (Sonoran Desert). We tested all samples for 16 short tandem repeats and sequenced 1,109 base pairs of mitochondrial DNA (mtDNA). To determine genetic origin, we performed assignment tests against a reference database of 997 desert tortoise samples collected throughout the Mojave and Sonoran Deserts. We found that >40% of our Arizona captive samples were genetically of Mojave Desert or hybrid origin, with the percentage of individuals exhibiting the Mojave genotype increasing as the sample locations approached the California, USA, border. In Phoenix, 11.5% were Sonoran–Mojave crosses, and 8.8% were hybrids between desert tortoise and Texas tortoise (G. berlandieri). Our findings present many potential implications for wild tortoises in the Sonoran Desert of Arizona. Escaped or released captive tortoises with Mojave or hybrid genotypes have the potential to affect the genetic composition of Sonoran wild populations. Genotyping captive desert tortoises could be used to inform the adoption process, and thereby provide additional protection to native desert-tortoise populations in Arizona.