1,447 research outputs found
Thermoconditional modulation of the pleiotropic sensitivity phenotype by the Saccharomyces cerevisiae PRP19 mutant allele pso4-1
The conditionally-lethal pso4-1 mutant allele of the spliceosomal-associated PRP19 gene allowed us to study this gene’s influence on pre-mRNA processing, DNA repair and sporulation. Phenotypes related to intron-containing genes were correlated to temperature. Splicing reporter systems and RT–PCR showed splicing efficiency in pso4-1 to be inversely correlated to growth temperature. A single amino acid substitution, replacing leucine with serine, was identified within the N-terminal region of the pso4-1 allele and was shown to affect the interacting properties of Pso4-1p. Amongst 24 interacting clones isolated in a two-hybrid screening, seven could be identified as parts of the RAD2, RLF2 and DBR1 genes. RAD2 encodes an endonuclease indispensable for nucleotide excision repair (NER), RLF2 encodes the major subunit of the chromatin assembly factor I, whose deletion results in sensitivity to UVC radiation, while DBR1 encodes the lariat RNA splicing debranching enzyme, which degrades intron lariat structures during splicing. Characterization of mutagen-sensitive phenotypes of rad2{Delta}, rlf2{Delta} and pso4-1 single and double mutant strains showed enhanced sensitivity for the rad2{Delta} pso4-1 and rlf2{Delta} pso4-1 double mutants, suggesting a functional interference of these proteins in DNA repair processes in Saccharomyces cerevisiae
Evaluating Joseph Campbell\u27s Underexplored Ideas In the Light of Modern Psychology
Joseph Campbell was a scholar of mythology and comparative religion who attained great popularity by promoting the value of mythology in people\u27s lives. Interestingly, he attained this status even though there was little scientific evidence for his ideas. In recent years, researchers have begun to evaluate Campbell\u27s ideas in rigorous, empirical ways, with most of this research being focused on the implications of the hero\u27s journey. There are still a number of Campbell\u27s psychology-related ideas, however, that have not been evaluated scientifically. These are the ideas we evaluated in this paper. Because we focused on the underexplored ideas, we could find no research directly assessing them. So, we evaluated them indirectly, using research that seemed relevant but that was conducted for independent reasons. This evaluation led us to conclude that Campbell was right in many of his psychology-related ideas, and that researchers could benefit if they took these ideas seriously and incorporated them into their research and theorizin
Distorted HI Gas in the Widely Separated LIRG Arp 256
We present new interferometric HI and CO (1-0) observations of the luminous
infrared source, Arp 256. Arp 256 consists of two spiral galaxies in an early
stage of merging, with a projected nuclear separation of 29 kpc (54") and an
infrared luminosity of 2.0E11 L_sun. Despite the large separation of the
galaxies' nuclei and mildly disrupted stellar components, the HI disks are
found to be strongly disrupted, and the southern galaxy in Arp 256 shows an
elevated star formation efficiency, which is consistent with a nuclear
starburst. Both of these results run contrary to expectations, posing
interesting questions on the physical mechanisms involved in stimulating star
formation during an interaction.Comment: 19 pages, 7 figures. Accepted for publication in AJ. Author added.
Full resolution figures available at
http://astro.uchicago.edu/home/web/jchen/arp25
New Concepts for Distinguishing the Hidden Patterns of Linkage Disequilibrium Which Underlie Association Between Genotypes and Complex Phenotypes
Affective Learning and Psychophysiological Reactivity in Dementia Patients
We examined the association of faces with biographical information that varied in emotional content in patients with Alzheimer's disease and a healthy control group. During two experimental sessions, participants rated neutral male faces on dimensions of hedonic valence and emotional arousal, later paired with fictitious biographical information. Both groups changed their ratings of the faces according to the biographical content. Free recall and recognition were tested in the second session. Patients neither recalled the biographical information nor recognized the faces, whereas the controls did. In addition, psychophysiological measures were taken in response to the face stimuli. Patients showed significant heart rate modulation as a function of their emotion ratings, whereas the controls did not. No correlation of rating changes with skin conductance was found in any group. Results suggest that psychophysiological reactions such as heart rate changes may indicate preserved affective associative learning in dementia patients despite impaired explicit memory
Mixed field reactions in ABO and Rh typing chimerism likely resulting from twin haematopoiesis.
Minkowski's Object: A Starburst Triggered by a Radio Jet, Revisited
We present neutral hydrogen, ultraviolet, optical and near-infrared imaging,
and optical spectroscopy, of Minkowski's Object (MO), a star forming peculiar
galaxy near NGC 541. The observations strengthen evidence that star formation
in MO was triggered by the radio jet from NGC 541. Key new results are the
discovery of a 4.9E8 solar mass double HI cloud straddling the radio jet
downstream from MO, where the jet changes direction and decollimates; strong
detections of MO, also showing double structure, in UV and H-alpha; and
numerous HII regions and associated clusters in MO. In UV, MO resembles the
radio-aligned, rest-frame UV morphologies in many high redshift radio galaxies
(HzRGs), also thought to be caused by jet-induced star formation. MO's stellar
population is dominated by a 7.5 Myr-old, 1.9E7 solar mass instantaneous burst,
with current star formation rate 0.52 solar masses per year (concentrated
upstream from where the HI column density is high). This is unlike the
jet-induced star formation in Centaurus A, where the jet interacts with
pre-existing cold gas; in MO the HI may have cooled out of a warmer, clumpy
intergalactic or interstellar medium as a result of jet interaction, followed
by collapse of the cooling clouds and subsequent star formation (consistent
with numerical simulations). Since the radio source that triggered star
formation in MO is much less luminous, and therefore more common, than powerful
HzRGs, and because the environment around MO is not particularly special in
terms of abundant dense, cold gas, jet-induced star formation in the early
universe might be even more prevalent than previously thought.Comment: 52 pages, 15 figures, accepted for publication in Ap
Cluster-randomized non-inferiority trial to compare supplement consumption and adherence to different dosing regimens for antenatal calcium and iron-folic acid supplementation to prevent preeclampsia and anaemia: rationale and design of the Micronutrient Initiative study
Background: To prevent pre-eclampsia in populations with insufficient dietary calcium (Ca) intake, the World Health Organisation (WHO) recommends routine Ca supplementation during antenatal care (ANC). WHO guidelines suggest a complex dosing regimen, requiring as many as 5 pill-taking events per day when combined with iron and folic acid (IFA) supplements. Poor adherence may undermine public health effectiveness, so simpler regimens may be preferable. This trial will compare the effect of the WHO-recommended (higher-dose) regimen vs. a simpler, lower-dose regimen on supplement consumption and pill-taking behaviours in Kenyan ANC clients. Design and methods: This is a parallel, non-inferiority, cluster-randomized trial; we examined 16 primary care health facilities in Kenya, 1047 pregnant women between 16-30 weeks gestational age. Higher-dose regimen: 1.5 g elemental calcium in 3 separate doses (500 mg Ca/pill) and IFA (60 mg Fe + 400 μg folic acid) taken with evening dose. Lower-dose regimen: 1.0 g calcium in 2 separate doses (500 mg Ca/pill) with IFA taken as above. Measurements: Primary outcome is Ca pills consumed per day, measured by pill counts. Secondary outcomes include IFA pills consumed per day, client knowledge, motivation, social support, and satisfaction, measured at 4 to 10 weeks post-enrolment. Statistical analyses: Unit of randomization is the health-care facility; unit of analysis is individual client. Intent-to-treat analysis will be implemented with multi-level models to account for clustering. Expected public health impact: If pregnant women prescribed lower doses of Ca ingest as many pills as women prescribed the WHO-recommended regimen, developing a lower-dose recommendation for antenatal Ca and IFA supplementation programs could save resources
Effects of Prebreeding Body Weight or Progestin Exposure Before Breeding on Beef Heifer Performance Through the Second Breeding Season
Two experiments evaluated prebreeding target BW or progestin exposure for heifers developed lighter than traditional recommendations. Experiment 1 evaluated the effects of the system on heifer performance through subsequent calving and rebreeding over 3 yr. Heifers (229 kg) were assigned randomly to be developed to 55% of mature BW (299 kg) before a 45-d breeding season (intensive, INT; n = 119) or 50% of mature BW (272 kg) before a 60-d breeding season (relaxed, RLX; n = 142). Prebreeding and pregnancy diagnosis BW were greater (P ≤ 0.006) for INT than RLX heifers. Overall pregnancy rate did not differ (88.4%; P = 0.51), but RLX heifers had later calving dates (7 d; P \u3c 0.001) and lighter calf weaning weights (194 ± 4 vs. 199 ± 4 kg; P \u3c 0.07) compared with INT heifers. Calf birth weight, calving difficulty, second-calf conception rates, and 2-yr-old retention rate did not differ (P \u3e 0.15) between systems. Cost per pregnant 2- yr-old cow was less for the RLX than the INT heifer development system. Of heifers that failed to become pregnant, a greater proportion (P = 0.07) of heifers in the RLX than in the INT system were prepubertal when the breeding season began. Therefore, a second 2-yr experiment evaluated melengestrol acetate (MGA, 0.5 mg/d) as a means of hastening puberty in heifers developed to 50% of mature BW. Heifers were assigned randomly to the control (n = 103) or MGA (n = 81) treatment for 14 d and were placed with bulls 13 d later for 45 d. Prebreeding and pregnancy diagnosis BW were similar (280 and 380 kg, respectively; P \u3e 0.10) for heifers in the control and MGA treatments. The proportion of heifers pubertal before breeding (74%), pregnancy rate (90%), calving date, calf weaning weight, and second breeding season pregnancy rate (92%) were similar (P \u3e 0.10) between treatments. Developing heifers to 50 or 55% of mature BW resulted in similar overall pregnancy rates, and supplementing the diets of heifers developed to 50% of mature BW with MGA before breeding did not improve reproductive performance
Effects of Prebreeding Body Weight or Progestin Exposure Before Breeding on Beef Heifer Performance Through the Second Breeding Season
Two experiments evaluated prebreeding target BW or progestin exposure for heifers developed lighter than traditional recommendations. Experiment 1 evaluated the effects of the system on heifer performance through subsequent calving and rebreeding over 3 yr. Heifers (229 kg) were assigned randomly to be developed to 55% of mature BW (299 kg) before a 45-d breeding season (intensive, INT; n = 119) or 50% of mature BW (272 kg) before a 60-d breeding season (relaxed, RLX; n = 142). Prebreeding and pregnancy diagnosis BW were greater (P ≤ 0.006) for INT than RLX heifers. Overall pregnancy rate did not differ (88.4%; P = 0.51), but RLX heifers had later calving dates (7 d; P \u3c 0.001) and lighter calf weaning weights (194 ± 4 vs. 199 ± 4 kg; P \u3c 0.07) compared with INT heifers. Calf birth weight, calving difficulty, second-calf conception rates, and 2-yr-old retention rate did not differ (P \u3e 0.15) between systems. Cost per pregnant 2- yr-old cow was less for the RLX than the INT heifer development system. Of heifers that failed to become pregnant, a greater proportion (P = 0.07) of heifers in the RLX than in the INT system were prepubertal when the breeding season began. Therefore, a second 2-yr experiment evaluated melengestrol acetate (MGA, 0.5 mg/d) as a means of hastening puberty in heifers developed to 50% of mature BW. Heifers were assigned randomly to the control (n = 103) or MGA (n = 81) treatment for 14 d and were placed with bulls 13 d later for 45 d. Prebreeding and pregnancy diagnosis BW were similar (280 and 380 kg, respectively; P \u3e 0.10) for heifers in the control and MGA treatments. The proportion of heifers pubertal before breeding (74%), pregnancy rate (90%), calving date, calf weaning weight, and second breeding season pregnancy rate (92%) were similar (P \u3e 0.10) between treatments. Developing heifers to 50 or 55% of mature BW resulted in similar overall pregnancy rates, and supplementing the diets of heifers developed to 50% of mature BW with MGA before breeding did not improve reproductive performance
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