47 research outputs found
Biological and Ecological Aspects of Field Released Fire Ant Decapitating Flies Pseudacteon spp. (Diptera: Phoridae), Parasitoids of Red Imported Fire Ants Solenopsis invicta Buren (Hymenoptera: Formicidae)
Multiple Pseudacteon phorid fly species, including P. tricuspis and P. curvatus,
have been released in the southern United States beginning in 1997 and 2003
(respectively) to serve as biological control agents against red imported fire ants
Solenopsis invicta Buren (hereafter referred to as RIFA). Field research in the United
States on phorid/RIFA interactions has addressed establishment and spread of released
species. Additionally, studies are needed on phorid biology and ecology with respect to
spatial distribution and phenology, phorid/habitat associations and phorid-mediated
affects on RIFA foraging patterns.
A suite of manipulative laboratory and field experiments/observations were
conducted to 1) develop a novel phorid sampling device to provide uniform and
repeatable sampling of flies, 2) assess spatial distributions and phenology of
Pseudacteon tricuspis and P. curvatus, 3) assess P. tricuspis and P. curvatus habitat
associations and 4) assess phorid-mediated affects on RIFA foraging patterns and caste
ratios. PTS Traps (developed for this research) are significantly more effective than
previous sampling methods in terms of mean number of flies collected, efficiency of use
and % trap success. Data collected with these traps allowed for the determination of
patterns of species-specific phenology and relative densities through time and speciesspecific
numerical/spatial superiority (Chapter IV). P. curvatus was significantly more
abundant than P. tricuspis in only one of the habitat types sampled (df (160) = 4.57, P <
0.005). P. tricuspis densities did not differ significantly among habitat type.
Llaboratory experiments revealed that phorid-exposed RIFA colonies foraged less
intensively diurnally (df = 1,558; P < 0.05) and more intensively nocturnally (df = 778;
P < 0.05) relative to control colonies. Field data regarding this compensatory nocturnal
foraging shift did not corroborate those of the laboratory work. In the field there was no
significant difference in foraging intensity during nocturnal (df (18) = -0.486, P = 0.633)
and diurnal (df (18) = 1.375 P = 0.186) sampling periods. Lastly, chi-square analysis of
RIFA forager size-classes revealed significant differences between phorid-infested
(treatment) and phorid-free (control) sites (X
2 = 6811.85, df = 3, P < 0.05) with a
significantly greater proportion of small RIFA foragers at the phorid-infested site
Performance of Altriset (TM) (Chlorantraniliprole) Termiticide Against Formosan Subterranean Termites, Coptotermes formosanus Shiraki, in Laboratory Feeding Cessation and Collateral Transfer Trials, and Field Applications
Chlorantraniliprole represents the first compound to be registered as a termiticide by the Environmental Protection Agency (EPA) in over a decade. This novel termiticide is currently registered as a 'reduced-risk pesticide' by the EPA. Laboratory and field trials were conducted to quantify mortality of Formosan subterranean termites (FST), Coptotermes formosanus Shiraki resulting from chlorantraniliprole treated soil, the degree to which the termites curtail feeding intensity post-exposure to chlorantraniliprole treated soil, collateral transfer of chlorantraniliprole among nest mates, and the effectiveness of chlorantraniliprole as a remedial treatment against structural infestations of HT. Termites which were exposed to chlorantraniliprole treated soil consumed significantly less paper than unexposed FST. The mean percent mortality of those termites exposed to chlorantraniliprole treated soil was significantly greater than that of unexposed FST. Depending on donor:recipient ratios, the mean mortality of recipients ranged from 14.65 - 90.00 % in the collateral transfer trials. There was a positive correlation between increased donor density and recipient mortality. Through 24 mo post-treatment, 27.3% of the structures which were treated in field trials were observed to have infestations of termites that required re-treatment; however, no FST were observed during the 30 and 36 month post-treatment inspections. Additionally, a novel scoring rubric was developed that will allow standardization of field study sites with respect to dissimilarity in site variables, and will allow for more consistent comparison of results across disparate field experiments. An explanation for the lack of successful remediation of many of the structures involved in the field trial is proposed and is based on our novel scoring system
Supercolonial structure of invasive populations of the tawny crazy ant Nylanderia fulva in the US
Background: Social insects are among the most serious invasive pests in the world, particularly successful at monopolizing environmental resources to outcompete native species and achieve ecological dominance. The invasive success of some social insects is enhanced by their unicolonial structure, under which the presence of numerous queens and the lack of aggression against non-nestmates allow high worker densities, colony growth, and survival while eliminating intra-specific competition. In this study, we investigated the population genetics, colony structure and levels of aggression in the tawny crazy ant, Nylanderia fulva, which was recently introduced into the United States from South America. Results: We found that this species experienced a genetic bottleneck during its invasion lowering its genetic diversity by 60%. Our results show that the introduction of N. fulva is associated with a shift in colony structure. This species exhibits a multicolonial organization in its native range, with colonies clearly separated from one another, whereas it displays a unicolonial system with no clear boundaries among nests in its invasive range. We uncovered an absence of genetic differentiation among populations across the entire invasive range, and a lack of aggressive behaviors towards conspecifics from different nests, even ones separated by several hundreds of kilometers. Conclusions: Overall, these results suggest that across its entire invasive range in the U.S.A., this species forms a single supercolony spreading more than 2000 km. In each invasive nest, we found several, up to hundreds, of reproductive queens, each being mated with a single male. The many reproductive queens per nests, together with the free movement of individuals between nests, leads to a relatedness coefficient among nestmate workers close to zero in introduced populations, calling into question the stability of this unicolonial system in which indirect fitness benefits to workers is apparently absent.Fil: Eyer, Pierre André. Texas A&M University; Estados UnidosFil: McDowell, Bryant. Texas A&M University; Estados UnidosFil: Johnson, Laura N. L.. Texas A&M University; Estados UnidosFil: Calcaterra, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Fernández, María Belén. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shoemaker, Dewayne. University of Tennessee; Estados UnidosFil: Puckett, Robert T.. Texas A&M University; Estados UnidosFil: Vargo, Edward L.. Texas A&M University; Estados Unido
Luminescent Ruthenium(II) Polypyridyl Functionalized Gold Nanoparticles; Their DNA Binding Abilities and Application As Cellular Imaging Agents
The synthesis and photophysical and biological
investigation of Ru(II)-polypyridyl stabilized watersoluble,
luminescent gold nanoparticles (AuNPs) are described.
These structures bind to DNA and undergo rapid
cellular uptake, being localized within the cell cytoplasm and
nucleus within 4 h
The structure of BVU2987 from Bacteroides vulgatus reveals a superfamily of bacterial periplasmic proteins with possible inhibitory function.
Proteins that contain the DUF2874 domain constitute a new Pfam family PF11396. Members of this family have predominantly been identified in microbes found in the human gut and oral cavity. The crystal structure of one member of this family, BVU2987 from Bacteroides vulgatus, has been determined, revealing a β-lactamase inhibitor protein-like structure with a tandem repeat of domains. Sequence analysis and structural comparisons reveal that BVU2987 and other DUF2874 proteins are related to β-lactamase inhibitor protein, PepSY and SmpA_OmlA proteins and hence are likely to function as inhibitory proteins
UBVRI Light Curves of 44 Type Ia Supernovae
We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from
1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence
Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The
data set comprises 2190 observations and is the largest homogeneously observed
and reduced sample of SN Ia to date, nearly doubling the number of
well-observed, nearby SN Ia with published multicolor CCD light curves. The
large sample of U-band photometry is a unique addition, with important
connections to SN Ia observed at high redshift. The decline rate of SN Ia
U-band light curves correlates well with the decline rate in other bands, as
does the U-B color at maximum light. However, the U-band peak magnitudes show
an increased dispersion relative to other bands even after accounting for
extinction and decline rate, amounting to an additional ~40% intrinsic scatter
compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication
in the Astronomical Journal. Version with high-res figures and electronic
data at http://astron.berkeley.edu/~saurabh/cfa2snIa
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β1-adrenergic receptor polymorphisms and clinical efficacy of betaxolol hydrochloride in normal volunteers
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Beta1-adrenergic receptor polymorphisms and clinical efficacy of betaxolol hydrochloride in normal volunteers
To evaluate the relationship between polymorphisms in the gene encoding the beta1-adrenergic receptor (beta1-AR) and clinical response to betaxolol hydrochloride 0.25% in a small pilot study of normal volunteers.
Prospective nonrandomized comparative trial.
Forty-eight consecutive normal volunteers who met all eligibility requirements for inclusion into this study.
Baseline intraocular pressure (IOP) was recorded. Subjects began treatment with betaxolol (1 drop both eyes twice daily) and underwent follow-up IOP recordings at 3 and 6 weeks. Peripheral blood was obtained for genetic analysis.
Response to betaxolol was calculated as the change in mean IOP from baseline (averaged between both eyes and averaged between both follow-up visits). The beta1-AR genotype was determined by polymerase chain reaction with restriction fragment length polymorphisms at codons 49 (serine [Ser] or glycine [Gly]) and 389 (arginine [Arg] or Gly).
There were 32 Ser49 homozygotes and 16 Gly49 carriers. There were no statistically significant differences between the Ser49 homozygotes and the Gly49 carriers with respect to baseline IOP or response to betaxolol therapy. There were 25 Arg389 homozygotes and 23 Gly389 carriers (22 heterozygotes and 1 Gly389 homozygote). As compared with Gly389 carriers, the Arg389 homozygotes had a higher baseline IOP (15.8 mmHg vs. 13.7 mmHg; P = 0.009) and a greater magnitude of response to betaxolol therapy (-3.4 mmHg vs. -1.5 mmHg; P = 0.0009). The Ser49 homozygote genotype was not independently associated with baseline IOP (P = 0.47) or with a response to betaxolol (P = 0.99). The Arg389 homozygote genotype was independently associated with a higher baseline IOP (P = 0.03) and a greater response to betaxolol (P = 0.03), even after adjusting for baseline IOP.
In this small pilot series, a single nucleotide polymorphism at codon 389 in the beta1-AR seems to correlate with a response to betaxolol therapy in normal, nonglaucomatous volunteers. There was no such correlation at codon 49. The polymorphism at codon 389 may predict short-term response to betaxolol and may serve as a determinant of response to betaxolol and other adrenergic agents in glaucomatous eyes requiring treatment