98 research outputs found
Feeding Records of Aphids (Hemiptera: Aphididae) From Wisconsin
Basic to our understanding of any animal and its habitat requirements is knowing what it eats. Reported here are observations of feeding by 27 species of aphids encountered in Wisconsin over 1992-2002
Feeding Records of Aphids (Hemiptera: Aphididae) From Wisconsin, Supplement
Basic to our understanding of any animal and its habitat requirements is knowing what it eats. Reported here are observations of feeding by 24 species of aphids encountered in Wisconsin over 2002-2010
Feeding Records of Aphids (Hemiptera: Aphididae) From Wisconsin
Basic to our understanding of any animal and its habitat requirements is knowing what it eats. Reported here are observations of feeding by 27 species of aphids encountered in Wisconsin over 1992-2002
Feeding Records of Aphids (Hemiptera: Aphididae) From Wisconsin, Supplement
Basic to our understanding of any animal and its habitat requirements is knowing what it eats. Reported here are observations of feeding by 24 species of aphids encountered in Wisconsin over 2002-2010
Natural History of the Slave Making Ant, Polyergus lucidus, Sensu lato in Northern Florida and Its Three Formica pallidefulva Group Hosts
Slave making ants of the Polyergus lucidus Mayr (Hymenoptera: Formicidae) complex enslave 3 different Formica species, Formica archboldi, F. dolosa, and F. pallidefalva, in northern Florida. This is the first record of presumed P. lucidus subspecies co-occurring with and enslaving multiple Formica hosts in the southern end of their range. The behavior, colony sizes, body sizes, nest architecture, and other natural history observations of Polyergus colonies and their Formica hosts are reported. The taxonomic and conservation implications of these observations are discussed
Allele-Selective Suppression of Mutant Huntingtin in Primary Human Blood Cells
Post-transcriptional gene silencing is a promising therapy for the monogenic, autosomal dominant, Huntington\u27s disease (HD). However, wild-type huntingtin (HTT) has important cellular functions, so the ideal strategy would selectively lower mutant HTT while sparing wild-type. HD patients were genotyped for heterozygosity at three SNP sites, before phasing each SNP allele to wild-type or mutant HTT. Primary ex vivo myeloid cells were isolated from heterozygous patients and transfected with SNP-targeted siRNA, using glucan particles taken up by phagocytosis. Highly selective mRNA knockdown was achieved when targeting each allele of rs362331 in exon 50 of the HTT transcript; this selectivity was also present on protein studies. However, similar selectivity was not observed when targeting rs362273 or rs362307. Furthermore, HD myeloid cells are hyper-reactive compared to control. Allele-selective suppression of either wild-type or mutant HTT produced a significant, equivalent reduction in the cytokine response of HD myeloid cells to LPS, suggesting that wild-type HTT has a novel immune function. We demonstrate a sequential therapeutic process comprising genotyping and mutant HTT-linkage of SNPs, followed by personalised allele-selective suppression in a small patient cohort. We further show that allele-selectivity in ex vivo patient cells is highly SNP-dependent, with implications for clinical trial target selection
The Formation and Evolution of Virgo Cluster Galaxies - I. Broadband Optical & Infrared Colours
We use a combination of deep optical (gri) and near-infrared (H) photometry
to study the radially-resolved colours of a broad sample of 300 Virgo cluster
galaxies. For most galaxy types, we find that the median g-H colour gradient is
either flat (gas-poor giants and gas-rich dwarfs) or negative (i.e., colours
become bluer with increasing radius; gas-poor dwarfs, spirals, and gas-poor
peculiars). Later-type galaxies typically exhibit more negative gradients than
early-types. Given the lack of a correlation between the central colours and
axis ratios of Virgo spiral galaxies, we argue that dust likely plays a small
role, if at all, in setting those colour gradients. We search for possible
correlations between galaxy colour and photometric structure or environment and
find that the Virgo galaxy colours become redder with increasing concentration,
luminosity and surface brightness, while no dependence with cluster-centric
radius or local galaxy density is detected (over a range of ~2 Mpc and ~3-16
Mpc^-2, respectively). However, the colours of gas-rich Virgo galaxies do
correlate with neutral gas deficiency, such that these galaxies become redder
with higher deficiencies. Comparisons with stellar population models suggest
that these colour gradients arise principally from variations in stellar
metallicity within these galaxies, while age variations only make a significant
contribution to the colour gradients of Virgo irregulars. A detailed stellar
population analysis based on this material is presented in Roediger et al
(2011b; arXiv:1011.3511).Comment: 34 pages, 12 figures, 1 table, submitted to MNRAS; Paper II
(arXiv:1011.3511) has also been update
Stellar populations of bulges at low redshift
This chapter summarizes our current understanding of the stellar population
properties of bulges and outlines important future research directions.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 34 pages, 12 figure
Isothermal Microcalorimetry, a New Tool to Monitor Drug Action against Trypanosoma brucei and Plasmodium falciparum
Isothermal microcalorimetry is an established tool to measure heat flow of physical, chemical or biological processes. The metabolism of viable cells produces heat, and if sufficient cells are present, their heat production can be assessed by this method. In this study, we investigated the heat flow of two medically important protozoans, Trypanosoma brucei rhodesiense and Plasmodium falciparum. Heat flow signals obtained for these pathogens allowed us to monitor parasite growth on a real-time basis as the signals correlated with the number of viable cells. To showcase the potential of microcalorimetry for measuring drug action on pathogenic organisms, we tested the method with three antitrypanosomal drugs, melarsoprol, suramin and pentamidine and three antiplasmodial drugs, chloroquine, artemether and dihydroartemisinin, each at two concentrations on the respective parasite. With the real time measurement, inhibition was observed immediately by a reduced heat flow compared to that in untreated control samples. The onset of drug action, the degree of inhibition and the time to death of the parasite culture could conveniently be monitored over several days. Microcalorimetry is a valuable element to be added to the toolbox for drug discovery for protozoal diseases such as human African trypanosomiasis and malaria. The method could probably be adapted to other protozoan parasites, especially those growing extracellularly
Stellar Population Trends in S0 Galaxies
We present stellar population age and metallicity trends for a sample of 59
S0 galaxies based on optical SDSS and NIR J & H photometry. When combined with
optical g and r passband imaging data from the SDSS archive and stellar
population models, we obtain radial age and metallicity trends out to at least
5 effective radii for most of the galaxies in our sample. The sample covers a
range in stellar mass and light concentration. We find an average central
light-weighted age of ~ 4 Gyr and central metallicity [Z/H] ~ 0.2 dex. Almost
all galaxies show a negative metallicity gradient from the center out, with an
average value of Delta[Z/H]/Delta(log(r/Re)) = -0.6. An age increase, decrease,
and minimal change with radius is observed for 58%, 19%, and 23%, respectively,
for a mean age gradient of Delta(age)/Delta(log(r/Re)) = 2.3 Gyr dex^{-1}. For
14 out of 59 galaxies, the light-weighted age of the outer region is greater
than 10 Gyr. We find that galaxies with both lower mass and lower concentration
have younger light-weighted ages and lower light-weighted metallicities. This
mass-metallicity relation extends into the outer regions of our S0 galaxies.
Our results are consistent with the formation of S0 galaxies through the
transformation of spiral galaxy disks. Determining the structural component
that makes up the outer region of galaxies with old outksirts is a necessary
step to understand the formation history of S0 galaxies.Comment: accepted to MNRA
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