1,199 research outputs found
The Ursinus Weekly, December 18, 1911
The second string • Football banquet • Schaff anniversary • Football resume • Dr. Culp pleased audience with lecture, Uncrowned Kings • Merry Christmas • Letters awarded • Yoh elected captain of 1912 varsity • Students celebrate football season with parade and bonfirehttps://digitalcommons.ursinus.edu/weekly/2751/thumbnail.jp
Evolutionary consequences of DNA methylation in a basal Metazoan
Gene body methylation (gbM) is an ancestral and widespread feature in Eukarya, yet its adaptive value and evolutionary implications remain unresolved. The occurrence of gbM within protein-coding sequences is particularly puzzling, because methylation causes cytosine hypermutability and hence is likely to produce deleterious amino acid substitutions. We investigate this enigma using an evolutionarily basal group of Metazoa, the stony corals (order Scleractinia, class Anthozoa, phylum Cnidaria). We show that patterns of coral gbM are similar to other invertebrate species, predicting wide and active transcription and slower sequence evolution. We also find a strong correlation between gbM and codon bias, resulting from systematic replacement of CpG bearing codons. We conclude that gbM has strong effects on codon evolution and speculate that this may influence establishment of optimal codons
Coping with multiple enemies : pairwise interactions do not predict evolutionary change in complex multitrophic communities
Predicting the ecological and evolutionary trajectories of populations in multispecies communities is one of the fundamental challenges in ecology. Many of these predictions are made by scaling patterns observed from pairwise interactions. Here, we show that the coupling of ecological and evolutionary outcomes is likely to be weaker in increasingly complex communities due to greater chance of life-history trait correlations. Using model microbial communities comprising a focal bacterial species (Bacillus subtilis), a bacterial competitor, protist predator and phage parasite, we found that increasing the number of enemies in a community had an overall negative effect on B. subtilis population growth. However, only the competitor imposed direct selection for B. subtilis trait evolution in pairwise cultures and this effect was weakened in the presence of other antagonists that had a negative effect on the competitor. In contrast, adaptation to parasites was driven indirectly by correlated selection where competitors had a positive and predators a negative effect. For all measured traits, selection in pairwise communities was a poor predictor of B. subtilis evolution in more complex communities. Together, our results suggest that coupling of ecological and evolutionary outcomes is interaction-specific and weakly coupled in more complex communities. We conclude that understanding 2 the ecological and evolutionary mechanisms underpinning trait correlations is crucial to predict species response to global change in complex microbial communitie
A One-sided, Highly Relativistic Jet from Cygnus X-3
Very Long Baseline Array images of the X-ray binary, Cygnus X-3, were
obtained 2, 4 and 7 days after the peak of a 10 Jy flare on 4 February 1997.
The first two images show a curved one-sided jet, the third a scatter-broadened
disc, presumably at the position of the core. The jet curvature changes from
the first to the second epoch, which strongly suggests a precessing jet. The
ratio of the flux density in the approaching to that in the (undetected)
receding jet is > 330; if this asymmetry is due to Doppler boosting, the
implied jet speed is > 0.81c. Precessing jet model fits, together with the
assumptions that the jet is intrinsically symmetric and was ejected during or
after the major flare, yield the following constraints: the jet inclination to
the line of sight must be < 14 degrees; the cone opening angle must be < 12
degrees; and the precession period must be > 60 days.Comment: 12 pages 7 figures, accepted by Ap
Die Agitpropbewegung als Teil der Arbeiterkultur der Weimarer Republik
The advent of next-generation sequencing has brought about an explosion of single nucleotide polymorphism (SNP) data in non-model organisms; however, profiling these SNPs across multiple natural populations still requires substantial time and resources. Results: Here, we introduce two cost-efficient quantitative High Resolution Melting (qHRM) methods for measuring allele frequencies at known SNP loci in pooled DNA samples: the "peaks" method, which can be applied to large numbers of SNPs, and the "curves" method, which is more labor intensive but also slightly more accurate. Using the reef-building coral Acropora millepora, we show that both qHRM methods can recover the allele proportions from mixtures prepared using two or more individuals of known genotype. We further demonstrate advantages of each method over previously published methods; specifically, the "peaks" method can be rapidly scaled to screen several hundred SNPs at once, whereas the "curves" method is better suited for smaller numbers of SNPs. Conclusions: Compared to genotyping individual samples, these methods can save considerable effort and genotyping costs when relatively few candidate SNPs must be profiled across a large number of populations. One of the main applications of this method could be validation of SNPs of interest identified in population genomic studies.Australian Institute of Marine ScienceNational Science Foundation DEB-1054766Cellular and Molecular Biolog
The Dynamic Exponent of the Two-Dimensional Ising Model and Monte Carlo Computation of the Sub-Dominant Eigenvalue of the Stochastic Matrix
We introduce a novel variance-reducing Monte Carlo algorithm for accurate
determination of autocorrelation times. We apply this method to two-dimensional
Ising systems with sizes up to , using single-spin flip dynamics,
random site selection and transition probabilities according to the heat-bath
method. From a finite-size scaling analysis of these autocorrelation times, the
dynamical critical exponent is determined as (12)
Total prostatectomy as a treatment for prostatic carcinoma in 25 dogs
Objective: To describe the complications and outcome after total prostatectomy in dogs with histologically confirmed prostatic carcinoma. Study Design: Multi-institutional retrospective case series. Animals: 25 client-owned dogs. Methods: Medical records of dogs undergoing total prostatectomy were reviewed from 2004 to 2016. Data retrieved included signalment, presenting signs, preoperative clinical findings, laboratory data, diagnostic imaging, surgical technique, histologic diagnosis, postoperative complications, occurrence of postoperative metastasis, and survival. Results: Twenty-five dogs underwent total prostatectomy for prostatic carcinoma. Urinary anastomotic techniques included urethrourethral anastomosis in 14 dogs, cystourethral anastomosis in 9 dogs, ureterocolonic anastomosis in 1 dog, and anastomosis between the bladder neck and penile urethra in 1 dog. All dogs survived to discharge. Fifteen dogs were diagnosed with transitional cell carcinoma, 8 dogs with prostatic adenocarcinoma, 1 with prostatic cystadenocarcinoma, and 1 with an undifferentiated carcinoma. Permanent postoperative urinary incontinence was present in 8 of 23 dogs. The median survival time was shorter in dogs with extracapsular tumor extension compared with those with intracapsular tumors. The overall median survival time was 231 days (range, 24-1255), with 1- and 2-year survival rates equal to 32% and 12%, respectively. Conclusion and Clinical Significance: Total prostatectomy, combined with adjunct therapies, prolongs survival and lowers complication rates compared to previous reports of dogs with prostatic carcinoma. It should be noted, however, that case selection likely played a significant role in postoperative outcome
Process development for manufacturing of cellular structures with controlled geometry and properties
This study presents experimental results on the behaviour of aluminium alloy metal structures and foams manufactured by lost-wax casting and using 3D printed components for internal structure definition. Results for tensile tests, metallurgical properties, surface quality and geometry tolerances were obtained and discussed. The analysis focused on development geometries, used for adjusting manufacturing parameters and prototype geometries intended for geometrical and mechanical validation. The results are indicative of the viability of the method for producing foam structures suitable for mechanical loading.The authors are grateful to the Portuguese Foundation for Science and Technology (FCT) who financially supported this work, through the project PTDC/EME-PME/115668/2009.info:eu-repo/semantics/publishedVersio
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