The assessment game in sand fiddler crab contests for breeding burrows

The single enlarged claw of male sand fiddler crabs, Uca pugilator, is used in contests for control of breeding burrows. The larger of the two contestants has the larger claw and usually wins. Males use one or more of 10 agonistic elements that vary in intensity from a no-contact extension of the claw to the flip of an opponent. We used the sequence of elements employed and the duration of unstaged, naturally occurring contests in a South Carolina salt marsh to evaluate three models of extended contests: (1) energetic war of attrition, (2) cumulative assessment and (3) sequential assessment. Contests usually began with elements of low action intensity and often proceeded to elements of high intensity. Elements of higher intensity were correlated with both contest duration and the number of contest elements. Contest duration increased as opponents became more evenly matched in size, a result consistent with both cumulative and sequential assessment models. Variation in duration increased as the relative sizes of opponents increased, also in accordance with sequential assessment. The absolute size of the smaller contestant had no effect on contest duration, in contrast to predictions based on cumulative assessment or energetic war of attrition models. Contestants that lost a fight were more likely to engage immediately in another fight without loss of contest intensity, if their previous fight had been long and intense. This result is inconsistent with contests of endurance, such as the energetic war of attrition or the cumulative assessment game, but it is consistent with the ritualized display of strength and fighting skill. Thus, sequential assessment appears to best explain ritualized fiddler crab contests. Cumulative assessment, however, may be the appropriate model for extended, nonritualized, all-out fights. Cumulative assessment may also explain the tenure of individuals on breeding grounds where multiple engagements are likely to test endurance and tolerance to damage over a period of days. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.      

Physical mapping of three fruit ripening genes：Endopolygalacturonase,ACC oxidase and ACC synthase from apple（Malus x domestica） in an apple rootstock A106（Malus sieboldii

The apple rootstock,A106(Malus sieboldii),had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell.Karyotypes were prepared from root-tip cells with 2n=34 chromosomes,Seven out of 82 karyotypes(8.5%) showed one pari of satellites at the end of the short arm of chromosome 3.C-bands were shown on 6 pairs of chromosomes 2,4,6,8,14,and 16 near the telomeric regions of short arms.Probes for three ripening-related genes from Malus x domestica:endopolygalacturonase(EPG,0.6kb),ACC oxidase(1.2kb),and ACC synthase(2kb)were hybridized in situ to metaphase chromosomes of A106.Hybridization sites for the EPG gene were observed on the long arm of chromosome 14 in 15 out of 16 replicate spreads and proximal to the centromere of chromosomes 6 and 11.For the ACC oxidase gene,hylridization sites were observed in the telomeric region of the short arm of chromosomes 5 and 11 in 87% and 81% of 16 spreads respectively,proxiaml to the centromere of chromosome 1 in 81% of the spreads,and on the long arm of chromosome 13 in 50% of the spreads. Physical mapping of three fruit ripening genes in an apple rootstock A106.Twenty five spreads were studied for the ACC synthase gene and hybridization sites were observed in the telomeric region of the short arm of chromosome 12 in 96% of the spreads.chromosomes 9 and 10 in 76% of the spreads,and chromosome 17 in 56% of the spreads.     

Making Sense of Human Ecology Mapping: An Overview of Approaches to Integrating Socio-Spatial Data into Environmental Planning

Ecosystem-based planning and management have stimulated the need to gather sociocultural values and human uses of land in formats accessible to diverse planners and researchers. Human Ecology Mapping (HEM) approaches offer promising spatial data gathering and analytical tools, while also addressing important questions about human-landscape connections. This article reviews and compares the characteristics of three HEM approaches that are increasingly used in natural resource management contexts, each focused on a particular aspect of human-environmental interactions. These aspects include tenure and resource use (TRU), local ecological knowledge (LEK), and sense of place (SOP). We discuss their origins, provide examples of their use, and identify challenges to their application. Our review serves as a guide for environmental managers, planners, and communities interested in gathering spatial data on aspects of human ecology important in ecosystem-based management and planning, and for scientists designing socioecological research.     

Genetic Analysis of the <Emphasis Type="Italic">Indri</Emphasis> Reveals No Evidence of Distinct Subspecies

Subspecies were traditionally defined by identifying gaps between phenotypes across the geographic range of a species, and may represent important units in the development of conservation strategies focused on preserving genetic diversity. Previous taxonomic research proposed that phenotypic variation between scattered Indri indri populations warranted the naming of two distinct subspecies, I. i. indri and I. i. variegatus. We tested these subspecific designations using mitochondrial sequence data generated from the control region or D-loop (569 bp) and a large section (2362 bp) of multiple genes and tRNAs known as Pastorini’s fragment and nuclear microsatellite markers. This study used 114 samples of I. indri from 12 rainforest sites in eastern Madagascar, encompassing the entire range of the species. These genetic samples represent multiple populations from low- and high-elevation forests from both putative subspecies. Molecular analyses of the mitochondrial sequence data did not support the two proposed subspecies. Furthermore, the microsatellite analyses showed no significant differences across the range beyond population level differentiation. This study demonstrates the utility of incorporating multiple lines of evidence in addition to phenotypic traits to define species or subspecies.     

Characterization of two TCR transgenic mouse lines specific for herpes simplex virus

To better understand the T cell-mediated processes involved in the immune response to herpes simplex virus type 1 (HSV-1)infection, two HSV-specific T cell receptor (TCR) transgenic mouse lines were produced. These mice (gBT-I.1 and gBT-I.3) are MHC class I-restricted and specific for the immunodominant peptide from HSV glycoprotein B (gB), gB498-505. Although derived from the same clone, the mice differ in the chromosomal location of the TCR transgenes and show marked differences in TCR alpha/beta expression on both CD4+ and CD8+ cells in the thymus. Despite this, peripheral CD8+ Tcells from both mice express equally high levels of the transgenic TCR and bind the KbgB498-505 tetramer to the same degree. In concordance with this, both were shown to respond equally well in vitro upon stimulation with the gB498-505 peptide or HSV-infected cells. These data show that selection of broadly equivalent peripheral T-cell subsets can occur in the presence of distinctly different thymic T-cell subsets.     

In vitro evaluation of native entomopathogenic fungi and neem (Azadiractha indica) extracts on Spodoptera frugiperda

The control of Spodoptera frugiperda is based on synthetic insecticides, so some alternatives are the use of entomopathogenic fungi (EF) and neem extract. The objective of the study was to evaluate in vitro effectiveness of native EF and neem extracts on S. frugiperda larvae. Six EF were identified by DNA sequencing of ITS regions from three EF (Fusarium solani, Metarrhizium robertsii, Nigrospora spherica and Penicillium citrinum). They were evaluated in concentrations of 1 × 10⁸ spores/ mL. In addition, a second bioassay was carried out evaluating only F. solani, M. robertsii and N. sphaerica and the addition of vegetable oil. On the other hand, extraction of secondary metabolites from neem seed (Azadirachta indica) was carried out by performing, mass (g) and solvent volume (mL ethanol and water) combinations, which were subjected to microwaves and ultrasound. Subsequently, these extracts were evaluated in concentrations of 3%, 4% and 5%. A survival analysis was performed for each of the bioassays. With respect to the results of the first bioassay, F. solani obtained a probability of survival of 0.476 on the seventh day, while in the second bioassay, M. robertsii obtained 0.488 survival probability. This suggests that the expected percentage of larvae that stay alive on the sixth day is 48.8%. However, in the evaluation of the neem extract the combination 1:12/70% to 4% caused 84% mortality of larvae. The use of native HE and neem extracts has potential for the control of S. frugiperda.     

The hydration of the neurotransmitter acetylcholine in aqueous solution

Neutron diffraction augmented with hydrogen isotope substitution has been used to examine the water structure around the acetylcholine molecular ion in aqueous solution. It is shown that the nearest-neighbor water molecules in the region around the trimethylammonium headgroup are located either in a ring around the central nitrogen atom or between the carbon atoms, forming a sheath around the onium group. Moreover the water molecules in this cavity do not bond to the onium group but rather form hydrogen bonds with water molecules in the surrounding aqueous environment. Given that in the bound state the onium headgroup must be completely desolvated, the absence of bonding between the onium headgroup and the surrounding water solvent may be selectively favorable to acetylcholine-binding in the receptor site. Away from the headgroup, pronounced hydrogen-bonding of water to the carbonyl oxygen is observed, but not to the ether oxygen in the acetylcholine chain.     

Assembly and disassembly of the photosystem II manganese cluster reversibly alters the coupling of the reaction center with the light-harvesting phycobilisome

The light-driven oxidative assembly of Mn (2+) ions into the H 2O oxidation complex (WOC) of the photosystem II (PSII) reaction center is termed photoactivation. The fluorescence yield characteristics of Synechocystis sp. PCC6803 cells undergoing photoactivation showed that basal fluorescence, F 0, exhibited a characteristic decline when red, but not blue, measuring light was employed. This result was traced to a progressive increase in the coupling of the phycobilisome (PBS) to the PSII reaction center as determined by observing the changes in room temperature and 77 K fluorescence emission spectra that accompany photoactivation. The results support the hypothesis that strong energetic coupling of the PBS to the PSII reaction center depends upon the formation of an active WOC, which presumably diminishes the likelihood of photodamage to reaction centers that have either lost an intact Mn cluster or are in the process of assembling an active WOC.     

Feedback inhibition of polyisoprenyl pyrophosphate synthesis from mevalonate in vitro. Implications for protein prenylation.

The prenylation of proteins utilizes the polyisoprenyl pyrophosphates (FPP) and geranylgeranyl pyrophosphate (GGPP) as prenyl donors. These polyisoprenoids are also precursors to ubiquinone and dolichol synthesis. We have previously described the geranylgeranylation of rab 1b from labeled mevalonate in rabbit reticulocyte lysates (Khosravi-Far, R., Lutz, R. J., Cox, A. D., Conroy, L., Bourne, J. R., Sinensky, M., Balch, W. E., Buss, J. C., and Der, C. J. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 6264-6268). We now directly demonstrate the incorporation of mevalonate into FPP and GGPP in rabbit reticulocyte cytosol. High pressure liquid chromatography analysis reveals that only all-trans-E,E,E-GGPP, the prenyl donor for in vivo protein geranylgeranylation, is synthesized. Incubations with recombinant H-ras and rab1b result in an increased synthesis of farnesyl and geranylgeranyl derivatives, respectively. The increase is wholly accounted for by protein-incorporated polyisoprenoids with no change in the polyisoprenyl pyrophosphate pools. Further, GGPP inhibits its own synthesis, without affecting FPP synthesis, with half-maximal inhibition at approximately 3 microM GGPP. Inhibition of FPP synthesis by the inhibition of isopentenyl isomerase causes a dramatic increase in isopentenyl pyrophosphate synthesis. FPP also inhibits conversion of mevalonate into FPP. These findings indicate that these polyisoprenyl pyrophosphates can down-regulate their own synthesis in vitro, and this regulation may control the levels of these polyisoprenoids in vivo.