1,520 research outputs found
Mechanisms of stomatal development: an evolutionary view
Plant development has a significant postembryonic phase that is guided heavily by interactions between the plant and the outside environment. This interplay is particularly evident in the development, pattern and function of stomata, epidermal pores on the aerial surfaces of land plants. Stomata have been found in fossils dating from more than 400 million years ago. Strikingly, the morphology of the individual stomatal complex is largely unchanged, but the sizes, numbers and arrangements of stomata and their surrounding cells have diversified tremendously. In many plants, stomata arise from specialized and transient stem-cell like compartments on the leaf. Studies in the flowering plant Arabidopsis thaliana have established a basic molecular framework for the acquisition of cell fate and generation of cell polarity in these compartments, as well as describing some of the key signals and receptors required to produce stomata in organized patterns and in environmentally optimized numbers. Here we present parallel analyses of stomatal developmental pathways at morphological and molecular levels and describe the innovations made by particular clades of plants
Methylation-sensitive binding of transcription factor YY1 to an insulator sequence within the paternally expressed imprinted gene, Peg3
The 5ïżœ-ends of two paternally expressed mouse genes, Peg3 and Usp29, are jointly associated with a CpG island that exhibits allele-specific methylation. Sequence comparison of the regions derived from human, mouse and cow revealed the presence of two evolutionarily conserved sequence motifs including one that is repeated multiple times within the first intron of Peg3 in all three mammals. DNA mobility shift and chromatin immunoprecipitation (ChlP) assays clearly demonstrated that this motif is an in vivo binding site for the Gli-type transcription factor YY1. The YY1-binding site contains one CpG dinucleotide, and methylation of this CpG site abolishes the binding activity of YY1 in vitro. The Peg3 YY1-binding sites are methylated only on the maternal chromosome in vivo, and ChlP assays confirmed that YY1 binds specifically to the paternal allele of the gene. Promoter, enhancer and insulator assays with deletion constructs of sequence surrounding the YY1-binding sites indicate that the region functions as a methylation-sensitive insulator that may influence the imprinted expression of Peg3 and neighboring genes. The current study is the first report demonstrating the involvement of YY1 in methylation-sensitive insulator activity and suggests a potential role of this highly conserved protein in mammalian genomic imprinting. © Oxford University Press 2001
Genomic organization and imprinting of the Peg3 domain in bovine
AbstractUsing multiple mammalian genomic sequences, we have analyzed the evolution and imprinting of several genes located in the Peg3 domain, including Mim1 (approved name, Mimt1), Usp29, Zim3, and Zfp264. A series of comparative analyses shows that the overall genomic structure of this 500-kb imprinted domain has been well maintained throughout mammalian evolution but that several lineage-specific changes have also occurred in each species. In the bovine domain, Usp29 has lost its protein-coding capability, Zim3 has been duplicated, and the expression of Zfp264 has become biallelic in brain and testis, which differs from paternal expression of mouse Zfp264 in brain. In contrast, the two transcript genes of cow, Mim1 and Usp29, both lacking protein-coding capability, are still expressed mainly from the paternal allele, indicating the imprinting of these two genes in cow. The imprinting of Mim1 and Usp29 along with Peg3 is the most evolutionarily selected feature in this imprinted domain, suggesting significant function of these three genes, either as protein-coding or as untranslated transcript genes
Logopeediline ravi Eesti tervishoiusĂŒsteemis 2010â2022: piirkondlikult ebaĂŒhtlane kĂ€ttesaadavus ja vĂ€henemas ravimaht
Logopeedilise ravi kĂ€ttesaadavust Eesti tervishoiusĂŒsteemis ei ole varem detailselt uuritud. Uuringu eesmĂ€rk oli kirjeldada tervishoiusĂŒsteemis osutatud logopeedilise raviteenuse kogumahtu tundides ning regionaalseid erinevusi ja ajalisi trende aastatel 2010â2022.AnalĂŒĂŒsiti Tervisekassast pĂ€ritud andmeid, kaasates kĂ”ik osutatud logopeedilised teenused, ning andmeid Eesti Maa-ameti, Tervise Arengu Instituudi ja Statistikaameti avalikest andmebaasidest.Keskmiselt osutati aastas 78 892 tundi logopeedilist ravi. Tundide kogumaht suurenes 15% vaadeldud perioodi alguses toimunud ambulatoorselt osutatud ravi mahu suurenemise arvelt, kuid edasise pideva langustrendi tĂ”ttu oli 2022. aastaks raviteenuse maht langenud 2012. aasta tasemele. VĂ€ikseim ravimaht pĂ€rast 2014. aastat ilmnes COVIDi-pandeemia ajal 2020. aastal. Piirkondlikult erines osutatud logopeedilise ravi maht suuresti. Osutatud ravimaht tundides 1000 elaniku kohta erines omavalitsustes kuni 367 korda. Piirkondlikult ebaĂŒhtlaselt kĂ€ttesaadav ravi tingis patsientide rĂ€nde teenuse jĂ€rele kodumaakonnast vĂ€ljapoole. Uuringu tulemused nĂ€itasid, et perioodil 2010â2022 suurenes mĂ”ningal mÀÀral logopeedilise ravi kogumaht perioodi algusaastatel toimunud osutatud ravi suurema ajalise mahu arvelt, kuid oli seejĂ€rel pidevas langustrendis ning ravi oli piirkondlikult ebaĂŒhtlaselt kĂ€ttesaadav.Uuring on esimene detailne ĂŒlevaade logopeedilise ravi osutamisest Eesti tervishoiusĂŒsteemis, tuues vĂ€lja selle regionaalselt ebaĂŒhtlase kĂ€ttesaadavuse ja kogumahu langustrendi. Eelnev viitab vajadusele ĂŒle vaadata siinse tervishoiusĂŒsteemi vĂ”imekus osutada nii praegu kui ka tulevikus erinevates piirkondades logopeedilist ravi
Promoting Investment and Increasing Employment among the Economically Inactive â A Review of Best Practice
This report sets out the findings from a study into strategies that link the promotion of investment and the employment of economically inactive groups. The aim is to ascertain current practice in 10 relevant countries (Australia; Belgium; Denmark; Finland; Germany; the Netherlands; New Zealand; Slovenia; Spain; USA plus Great Britain) and their transferability to the Northern Ireland (NI) policy and labour market context. The study was carried out by the Employment Research Institute at Edinburgh Napier University on behalf of the Department of Trade, Enterprise and Investment in NI (DETI)
Anpassung von GebÀuden
Dies ist ein Faktenblatt aus dem REGKLAM-Vorhaben zum Thema "Anpassung von GebÀuden"
Effects of the addition of high-dose vitamin C to polyethylene glycol solution for colonic cleansing: A pilot study in healthy volunteers
AbstractBackground:Polyethylene glycol (PEG) solutions, with or without osmotic agents, are used to empty the large intestine before procedures such as colonoscopy or colonic surgery. Data concerning the effectiveness of vitamin C as an ingredient in colonic preparations are scant.Objective:The aim of this article was to assess the effectiveness, acceptability, and tolerability of 6 preparations of a standard PEG electrolyte solution containing different doses of PEG, vitamin C (as an osmotic agent), and sodium sulfate in colonic cleansing.Methods:This double-blind, randomized, 2-period crossover study was conducted at the LariboisiĂšre Hospital, Paris, France. Healthy adult volunteers were randomly assigned to receive 2 of 6 colonic cleansing preparations, each containing different doses of PEG (100 or 125 g/L), vitamin C (0, 5, or 10 g/L, in the form of sodium ascorbate, ascorbic acid, or a mixture of both), and sodium sulfate (5 or 7.5 g/L), diluted in water to a volume of 2 L. Study drug administration was separated by a washout period of 7 to 15 days, after which the volunteers received an alternate preparation. Stools were collected for 10 hours after the start of solution ingestion. The primary efficacy end point was stool volume. Secondary end points included acceptability of taste, assessed using a 100-mm visual analog scale (VAS) (0 = excellent to 100 = execrable), taste criteria (saltiness, acidity, and sweetness, assessed on a 4-point Likert-type scale [0 = very pleasant to 3 = intolerable]) and tolerability (clinical effects [changes in body weight, blood pressure, heart rate, and nausea and vomiting] and biologic effects [changes in serum electrolytes, creatinine, hematocrit, and ascorbic acid]).Results:Thirty volunteers (15 men, 15 women; mean [SD] age, 29.8 [8.2] years [range, 20â45 years]) were enrolled and completed the study. Mean (SD) stool volume obtained with preparations containing 10 g/L of vitamin C did not differ significantly from the volume obtained without vitamin C (2.54 [0.54] L vs 1.93 [0.62] L; 95% CI, â0.13 to 1.47). Mean (SD) VAS scores for acceptability of taste ranged from 54.4 (25.0) (preparation E) to 74.4 (20.1) (preparation C) (P = 0.03 preparation E vs all other preparations). The only significant difference in taste criteria was in acidity, with preparation A being the least acidic according to patients' ratings on the VAS (1.4 [0.7] vs 1.8 [0.4] [mean of the other 5 preparations combined]; P = 0.04 preparation A vs all other preparations). Mild dehydration occurred in 6 subjects (1 for each preparation). No clinical or biological adverse effects were found.Conclusions:In this study of 6 colonic cleansing preparations in healthy volunteers, the use of high-dose vitamin C as an osmotic agent in addition to PEG did not significantly increase stool output. All 6 preparations were well tolerated
Modulation of Asymmetric Division Diversity through Cytokinin and SPEECHLESS Regulatory Interactions in the Arabidopsis Stomatal Lineage
Coordinated growth of organs requires communication among cells within and between tissues. In plants, leaf growth is largely dictated by the epidermis; here, asymmetric and self-renewing divisions of the stomatal lineage create two essential cell typesâpavement cells and guard cellsâin proportions reflecting inputs from local, systemic, and environmental cues. The transcription factor SPEECHLESS (SPCH) is the prime regulator of divisions, but whether and how it is influenced by external cues to provide flexible development is enigmatic. Here, we show that the phytohormone cytokinin (CK) can act as an endogenous signal to affect the extent and types of stomatal lineage divisions and forms a regulatory circuit with SPCH. Local domains of low CK signaling are created by SPCH-dependent cell-type-specific activity of two repressive type-A ARABIDOPSIS RESPONSE REGULATORs (ARRs), ARR16 and ARR17, and two secreted peptides, CLE9 and CLE10, which, together with SPCH, can customize epidermal cell-type composition
Individual plumage and integument scoring of laying hens on commercial farms: correlation with severe feather pecking and prognosis by visual scoring on flock level
Various plumage and integument scoring methods are commonly used to deduce the occurrence of severe feather pecking and cannibalism in laying hens. The aim of our study was to provide evidence of correlations between the occurrence of severe feather pecking and our individual plumage scoring system used under practical conditions on commercial farms with nonâbeak-trimmed and beak-trimmed layers (study I). In second step, we aimed to verify whether the results of the elaborate individual scoring may be predicted with a visual scoring method based on the total body scores of groups of birds (study II). For study I we observed the pecking behavior and performed an individual plumage scoring at the beginning, in the middle, and at the end of a laying period on 8 commercial farms. For study II we performed both an individual and a visual plumage scoring on 49 flocks on 45 farms at the beginning of the laying period and on 43 flocks on 41 farms at the end of the laying period. Spearman's Rho revealed a correlation of the mean feather pecking rate with the total plumage score, the neckâback plumage score, and the total cannibalism score in all observation periods. A high feather pecking rate was correlated with severe plumage damage and the frequent occurrence of skin injuries. We conclude that both the total plumage score and the neckâback plumage score constitute a reliable indicator of the occurrence of severe feather pecking in the flocks assessed in this study. The results of study II suggest that the percental assessment of plumage damage on flock level in 3 categories (âvisual scoreâ) leads to a good prognosis of the actual, individually assessed plumage score. Therefore, the application (and documentation) of the visual score on a regular basis can provide a good evaluation of the development of the plumage condition of the flock. The visual score presented in this study is suggested as a suitable instrument for self-evaluation programs on farms
Physical Properties of Young Stellar Populations in 24 Starburst Galaxies Observed with FUSE
We presents the main physical properties of very young stellar populations
seen with FUSE in 24 individual starbursts. These characteristics have been
obtained using the evolutionary spectral synthesis technique in the
far-ultraviolet range with the LavalSB code. For each starburst, quantitative
values for age, metallicity, initial mass function slope, stellar mass, and
internal extinction have been obtained and discussed in details. Limits of the
code have been tested. One main conclusion is that most starbursts (and
probably all of them) cannot be represented by any continuous star formation
burst in the far-ultraviolet. Also, quantitative values of various optical
diagnostics related to these stellar populations have been predicted.
Underlying stellar populations, dominated by B-type stars, have been detected
in NGC 1140, NGC 4449, and possibly NGC 3991. We characterized the young
stellar populations of less than 5 Myr in Seyfert 2 nuclei.Comment: 24 pages including figures. Accepted for publication in MNRA
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