241 research outputs found
The snail-killing flies of Alaska (Diptera: Sciomyzidae)
Information is given on the geographic distribution, habitat preferences, larval foods, and immature stages for 57 species of 9 genera of Sciomyzidae known to occur in Alaska. An illustrated key to adults is included. Alaska as a habitat for sciomyzid flies is discussed, and information on feeding habits of the larvae is summarized
The Invertebrate Prey of the Northern Leopard Frog, Rana pipiens, in a Northeastern Ohio Population
Author Institution: Department of Biological Sciences, Kent State UniversityThe purpose of this investigation was to determine the feeding habits of the northern leopard frog, Rana pipiens, in northeastern Ohio. To accomplish this we examined the stomach contents of 13 adults and 19 juveniles collected from a restored wetland in Summit County, Ohio during the summers of 1996 and 1997. The adult and juvenile frogs ingested 142 invertebrates representing 2 phyla, 3 classes, 12 orders, and 34 families. Adult and juvenile frogs consumed both diurnal and nocturnal prey belonging primarily to the insect orders Coleoptera, Hemiptera, and Hymenoptera. Although juvenile frogs consumed more individual prey items than adults (t = 2.196, p <0.05), neither age cohort specialized on active or inactive prey (X2 = 3.84, p <0.05)- Approximately 67% of all prey consumed consisted of fossorial or crawling organisms. Our data suggest that R. pipiens is an efficient predator that maximizes prey diversity by employing more than one feeding strategy
Sharpenings of Li's criterion for the Riemann Hypothesis
Exact and asymptotic formulae are displayed for the coefficients
used in Li's criterion for the Riemann Hypothesis. For we obtain
that if (and only if) the Hypothesis is true,
(with and explicitly given, also for the case of more general zeta or
-functions); whereas in the opposite case, has a non-tempered
oscillatory form.Comment: 10 pages, Math. Phys. Anal. Geom (2006, at press). V2: minor text
corrections and updated reference
Self-assembly of phosphate fluorosurfactants in carbon dioxide
Anionic phosphodiester surfactants, possessing either two fluorinated chains (F/F) or one hydrocarbon chain and one fluorinated chain (H/F), were synthesized and evaluated for solubility and self-assembly in liquid and supercritical carbon dioxide. Several surfactants, of both F/F and EUF types and having varied counterions, were found to be capable of solubilizing water-in-CO2 (W/C), via the formation of microemulsions, expanding upon the family of phosphate fluorosurfactants already found to stabilize W/C microemulsions. Small-angle neutron scattering was used to directly characterize the microemulsion particles at varied temperatures, pressures, and water loadings, revealing behavior consistent with previous results on W/C microemulsions
Functional Outcomes of Brolucizumab-Induced Intraocular Inflammation Involving the Posterior Segment-A Meta-Analysis and Systematic Review.
Early poor outcomes of intraocular inflammation (IOI) after intravitreal brolucizumab (IVB) have negatively affected the use of brolucizumab in clinical routine. We wished to identify factors related to the treatment details of IOI involving the posterior segment resulting from IVB for neovascular AMD (nAMD), if these were reported in detail. Articles were retrieved from PubMed, Scopus, ClinicalTrials, and CENTRAL using the following search terms: AND AND . The risk of bias was rated using the JBI Critical Appraisal Tool. We included 31 reports (41 patients and 46 eyes). Patients were 75.9 ± 8.5 years, and 58.5% were female. IOI occurred 41.7 ± 37.5 (median 37.0) days after treatment initiation with 2.0 ± 1.3 (1-6) IVB injections. A mean change in visual acuity of -14.6 ± 21.0 (median -6.5) letters was reported. The mean time from first IOI signs to the initiation of any anti-inflammatory treatment was 3.3 ± 6.2 days, with 63% of the patients receiving systemic corticosteroids as standard treatment. Finally, a period effect was observed, with a change in visual acuity of -25.3 ± 27.1 and -2.6 ± 7.3 letters in the chronologically first and last third, respectively, of treated eyes (effect size: r = 0.71; p = 0.006). Functional outcomes markedly improved with increasing experience in managing IOI
Characterization of adjacent breast tumors using oligonucleotide microarrays
BACKGROUND: Current methodology often cannot distinguish second primary breast cancers from multifocal disease, a potentially important distinction for clinical management. In the present study we evaluated the use of oligonucleotide-based microarray analysis in determining the clonality of tumors by comparing gene expression profiles. METHOD: Total RNA was extracted from two tumors with no apparent physical connection that were located in the right breast of an 87-year-old woman diagnosed with invasive ductal carcinoma (IDC). The RNA was hybridized to the Affymetrix Human Genome U95A Gene Chip(®) (12,500 known human genes) and analyzed using the Gene Chip Analysis Suite(®) 3.3 (Affymetrix, Inc, Santa Clara, CA, USA) and JMPIN(®) 3.2.6 (SAS Institute, Inc, Cary, NC, USA). Gene expression profiles of tumors from five additional patients were compared in order to evaluate the heterogeneity in gene expression between tumors with similar clinical characteristics. RESULTS: The adjacent breast tumors had a pairwise correlation coefficient of 0.987, and were essentially indistinguishable by microarray analysis. Analysis of gene expression profiles from different individuals, however, generated a pairwise correlation coefficient of 0.710. CONCLUSION: Transcriptional profiling may be a useful diagnostic tool for determining tumor clonality and heterogeneity, and may ultimately impact on therapeutic decision making
Predatory capacity of a shorefly, Ochthera chalybescens, on malaria vectors
<p>Abstract</p> <p>Background</p> <p>Since <it>Ochthera chalybescens </it>had been reported to prey on African malaria vectors, the predatory capacity of adults of this species on <it>Anopheles gambiae </it>sensu stricto was explored.</p> <p>Method</p> <p>Predatory capacity of this fly on <it>A. gambiae </it>s.s. was tested at all developmental stages, including the adult stage in the laboratory setting. Effects of water depth on its predatory capacity were also examined.</p> <p>Results</p> <p>This study revealed that <it>O. chalybescens </it>preyed on mosquitoes at all life stages except eggs. It was able to prey on an average of 9.8 to 18.8 mosquito larvae in 24 hrs. Mosquito larva size and water depth did not affect predatory capacity. However, the predacious fly preyed on significantly more 2<sup>nd</sup>-instar larvae than on pupae when larvae and pupae were both available.</p> <p>Conclusion</p> <p><it>Ochthera chalybescens </it>is, by all indications, an important predator of African malaria vectors.</p
Neuroscience, Ethics, and National Security: The State of the Art
Military involvement and research in neuroscience generates unique ethical, legal, and social issues that require careful elucidation and consideration in order to align the potentially conflicting needs of national defense, public interest, and scientific progress
A role for hydrophobicity in a Diels–Alder reaction catalyzed by pyridyl-modified RNA
New classes of RNA enzymes or ribozymes have been obtained by in vitro evolution and selection of RNA molecules. Incorporation of modified nucleotides into the RNA sequence has been proposed to enhance function. DA22 is a modified RNA containing 5-(4-pyridylmethyl) carboxamide uridines, which has been selected for its ability to promote a Diels–Alder cycloaddition reaction. Here, we show that DA_TR96, the most active member of the DA22 RNA sequence family, which was selected with pyridyl-modified nucleotides, accelerates a cycloaddition reaction between anthracene and maleimide derivatives with high turnover. These widely used reactants were not used in the original selection for DA22 and yet here they provide the first demonstration of DA_TR96 as a true multiple-turnover catalyst. In addition, the absence of a structural or essential kinetic role for Cu2+, as initially postulated, and nonsequence-specific hydrophobic interactions with the anthracene substrate have led to a reevaluation of the pyridine modification's role. These findings broaden the catalytic repertoire of the DA22 family of pyridyl-modified RNAs and suggest a key role for the hydrophobic effect in the catalytic mechanism
A first genome assembly of the barley fungal pathogen Pyrenophora teres f. teres
Background: Pyrenophora teres f. teres is a necrotrophic fungal pathogen and the cause of one of barley’s most important diseases, net form of net blotch. Here we report the first genome assembly for this species based solely on short Solexa sequencing reads of isolate 0-1. The assembly was validated by comparison to BAC sequences, ESTs, orthologous genes and by PCR, and complemented by cytogenetic karyotyping and the first genome-wide genetic map for P. teres f. teres. Results: The total assembly was 41.95 Mbp and contains 11,799 gene models of 50 amino acids or more. Comparison against two sequenced BACs showed that complex regions with a high GC content assembled effectively. Electrophoretic karyotyping showed distinct chromosomal polymorphisms between isolates 0-1 and 15A, and cytological karyotyping confirmed the presence of at least nine chromosomes. The genetic map spans 2477.7 cM and is composed of 243 markers in 25 linkage groups, and incorporates SSR markers developed from the assembly. Among predicted genes, non-ribosomal peptide synthetases and efflux pumps in particular appear to have undergone a P. teres f. teres-specific expansion of non-orthologous gene families. Conclusions: This study demonstrates that paired-end Solexa sequencing can successfully capture coding regions of a filamentous fungal genome. The assembly contains a plethora of predicted genes that have been implicated in a necrotrophic lifestyle and pathogenicity and presents a significant resource for examining the bases for P. teres f. teres pathogenicity
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