618 research outputs found
Whole Crop Cereal Silage in Dairy Production
Whole-crop cereal silages (WCCS) are used to some extent in Sweden, but knowledge about the use of this feed for high yielding dairy cows is scarce. The crop is often harvested at different stages of maturity, from heading to yellow ripeness, which gives forages that differ in chemical composition. The purpose of this trial was to compare intake and milk production of dairy cows fed a WCCS based on barley harvested at three different stages of maturity
Field Beans and Spring Wheat as Whole Crop Silage: Yield, Chemical Composition and Fermentation Characteristics
There has been an increasing interest in field beans (Vicia faba L.) in recent years because of its N-fixating ability. The objective of this study was to compare the yield, chemical composition and fermentation characteristics of field bean/spring wheat as whole-crop silage ensiled with and without an additive.
The crop was drilled on 27 May 2003 at a seed rate of 205 kg/ha field beans and 68 kg/ha spring wheat. The crop was harvested at four different growth stages (Zadoks et al., 1974); end of blooming, (stage 69), when 50% of the pods had reached full length, (stage 75), pods fully formed, (stage 79) and when 10% of the pods are filled (stage 81). Yield and botanical composition were evaluated. Samples of the forage were analysed for dry matter (DM) and chemical composition at harvest. Forage, at stages 75, 79 and 81 was wilted overnight then chopped (20 mm) and ensiled in 10 kg silos. Half the forage was ensiled untreated (control). The other half was treated with PROENS (60-66% formic acid and 23-29% propionic acid, Perstorp Speciality Chemicals, Sweden) applied at a rate of 6 l/t fresh matter. The silos were incubated for a period of 90 d and then analysed for DM, chemical composition and fermentation characteristics
Relative Importance of Nitric Oxide Physical Drivers in the Lower Thermosphere
Nitric oxide (NO) observations from the Solar Occultation for Ice Experiment and Student Nitric Oxide Explorer satellite instruments are investigated to determine the relative importance of drivers of shortâterm NO variability. We study the variations of deseasonalized NO anomalies by removing a climatology, which explains between approximately 70% and 90% of the total NO budget, and relate them to variability in geomagnetic activity and solar radiation. Throughout the lower thermosphere geomagnetic activity is the dominant process at high latitudes, while in the equatorial region solar radiation is the primary source of shortâterm NO changes. Consistent results are obtained on estimated geomagnetic and radiation contributions of NO variations in the two data sets, which are nearly a decade apart in time. The analysis presented here can be applied to model simulations of NO to investigate the accuracy of the parametrized physical drivers
Showing Their True Colors? How EU Flag Display Affects Perceptions of Party Elitesâ European Attachment
Evidence suggests that incidental national flag exposure activates nationalistic feelings and that incidental exposure to the EU flag can affect citizen attachments to Europe. However, we know little about what inferences citizens make based on the EU flag when they see it displayed by parties in an electoral context. To test the expectation that this display affects citizensâ evaluations of party elitesâ EU attachment, we conducted a large-scale experiment embedded in a Swedish survey in which respondents were exposed to communications from one of the two main Swedish parties, containing or not containing the image of the flag. We find that simple visual display does little to move perceptions. However, if citizens perceive that a particular party displayed the flag, then they are more likely to evaluate its party elites as more attached to Europe
The impact of the Kasatochi eruption on the Moon's illumination during the August 2008 lunar eclipse
The Moon's changeable aspect during a lunar eclipse is largely attributable
to variations in the refracted unscattered sunlight absorbed by the terrestrial
atmosphere that occur as the satellite crosses the Earth's shadow. The
contribution to the Moon's aspect from sunlight scattered at the Earth's
terminator is generally deemed minor. However, our analysis of a published
spectrum of the 16 August 2008 lunar eclipse shows that diffuse sunlight is a
major component of the measured spectrum at wavelengths shorter than 600 nm.
The conclusion is supported by two distinct features, namely the spectrum's
tail at short wavelengths and the unequal absorption by an oxygen collisional
complex at two nearby bands. Our findings are consistent with the presence of
the volcanic cloud reported at high northern latitudes following the 7-8 August
2008 eruption in Alaska of the Kasatochi volcano. The cloud both attenuates the
unscattered sunlight and enhances moderately the scattered component, thus
modifying the contrast between the two contributions.Comment: Accepted for publication in Geophysical Research Letter
Positional Concerns among the Poor: Does Reference Group Matter? Evidence from Survey Experiments
Previous research suggests a lower degree of positional concerns among people from poor countries. Yet the evidence is limited and most often builds on the assumption that people's reference groups are the same across all individuals. We conduct a survey experiment in urban Ethiopia that is modified to include multiplicity of reference groups. We estimate positional concerns considering various reference groups to test whether the low positional concerns found in the literature is due to misspecification of the reference groups. The results show a low degree of positional concern which is highly stable across different reference groups
Human Dna2 is a nuclear and mitochondrial DNA maintenance protein
Dna2 is a highly conserved helicase/nuclease that in yeast participates in Okazaki fragment processing, DNA repair, and telomere maintenance. Here, we investigated the biological function of human Dna2 (hDna2). Immunofluorescence and biochemical fractionation studies demonstrated that hDna2 was present in both the nucleus and the mitochondria. Analysis of mitochondrial hDna2 revealed that it colocalized with a subfraction of DNA-containing mitochondrial nucleoids in unperturbed cells. Upon the expression of disease-associated mutant forms of the mitochondrial Twinkle helicase which induce DNA replication pausing/stalling, hDna2 accumulated within nucleoids. RNA interference-mediated depletion of hDna2 led to a modest decrease in mitochondrial DNA replication intermediates and inefficient repair of damaged mitochondrial DNA. Importantly, hDna2 depletion also resulted in the appearance of aneuploid cells and the formation of internuclear chromatin bridges, indicating that nuclear hDna2 plays a role in genomic DNA stability. Together, our data indicate that hDna2 is similar to its yeast counterpart and is a new addition to the growing list of proteins that participate in both nuclear and mitochondrial DNA maintenance
Opposite transcriptional regulation in skeletal muscle of AMP-activated protein kinase gamma3 R225Q transgenic versus knock-out mice
AMP-activated protein kinase (AMPK) is an evolutionarily conserved heterotrimer important for metabolic sensing in all eukaryotes. The muscle-specific isoform of the regulatory gamma-subunit of the kinase, AMPK gamma3, has an important role in glucose uptake, glycogen synthesis, and fat oxidation in white skeletal muscle, as previously demonstrated by physiological characterization of AMPK gamma3 mutant (R225Q) transgenic (TgPrkag3(225Q)) and gamma3 knock-out (Prkag3(-/-)) mice. We determined AMPK gamma3-dependent regulation of gene expression by analyzing global transcription profiles in glycolytic skeletal muscle from gamma3 mutant transgenic and knock-out mice using oligonucleotide microarray technology. Evidence is provided for coordinated and reciprocal regulation of multiple key components in glucose and fat metabolism, as well as skeletal muscle ergogenics in TgPrkag3(225Q) and Prkag3(-/-) mice. The differential gene expression profile was consistent with the physiological differences between the models, providing a molecular mechanism for the observed phenotype. The striking pattern of opposing transcriptional changes between TgPrkag3(225Q) and Prkag3(-/-) mice identifies differentially expressed targets being truly regulated by AMPK and is consistent with the view that R225Q is an activating mutation, in terms of its downstream effects. Additionally, we identified a wide array of novel targets and regulatory pathways for AMPK in skeletal muscle
HER2-positive tumors imaged within 1 hour using a site-specifically 11C-labeled sel-tagged affibody molecule
A rapid, reliable method for distinguishing tumors or metastases that overexpress human epidermal growth factor receptor 2 (HER2) from those that do not is highly desired for individualizing therapy and predicting prognoses. In vivo imaging methods are available but not yet in clinical practice; new methodologies improving speed, sensitivity, and specificity are required.
METHODS: A HER2-binding Affibody molecule, Z(HER2:342), was recombinantly fused with a C-terminal selenocysteine-containing tetrapeptide Sel-tag, allowing site-specific labeling with either (11)C or (68)Ga, followed by biodistribution studies with small-animal PET. Dosimetry data for the 2 radiotracers were compared. Imaging of HER2-expressing human tumor xenografts was performed using the (11)C-labeled Affibody molecule.
RESULTS: Both the (11)C- and (68)Ga-labeled tracers initially cleared rapidly from the blood, followed by a slower decrease to 4-5 percentage injected dose per gram of tissue at 1 h. Final retention in the kidneys was much lower (>5-fold) for the (11)C-labeled protein, and its overall absorbed dose was considerably lower. (11)C-Z(HER2:342) showed excellent tumor-targeting capability, with almost 10 percentage injected dose per gram of tissue in HER2-expressing tumors within 1 h. Specificity was demonstrated by preblocking binding sites with excess ligand, yielding significantly reduced radiotracer uptake (P = 0.002), comparable to uptake in tumors with low HER2 expression.
CONCLUSION: To our knowledge, the Sel-tagging technique is the first that enables site-specific (11)C-radiolabeling of proteins. Here we present the finding that, in a favorable combination between radionuclide half-life and in vivo pharmacokinetics of the Affibody molecules, (11)C-labeled Sel-tagged Z(HER2:342) can successfully be used for rapid and repeated PET studies of HER2 expression in tumors.VetenskapsrÄdetPublishe
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