535 research outputs found
TIPT2 and geminin interact with basal transcription factors to synergize in transcriptional regulation
No full textBackground The re-replication inhibitor Geminin binds to several transcription factors including homeodomain proteins, and to members of the polycomb and the SWI/SNF complexes. Results Here we describe the TATA-binding protein-like factor-interacting protein (TIPT) isoform 2, as a strong binding partner of Geminin. TIPT2 is widely expressed in mouse embryonic and adult tissues, residing both in cyto- and nucleoplasma, and enriched in the nucleolus. Like Geminin, also TIPT2 interacts with several polycomb factors, with the general transcription factor TBP (TATA box binding protein), and with the related protein TBPL1 (TRF2). TIPT2 synergizes with geminin and TBP in the activation of TATA box-containing promoters, and with TBPL1 and geminin in the activation of the TATA-less NF1 promoter. Geminin and TIPT2 were detected in the chromatin near TBP/TBPL1 binding sites. Conclusion Together, our study introduces a novel transcriptional regulator and its function in cooperation with chromatin associated factors and the basal transcription machinery
Combining grating-coupled illumination and image recognition for stable and localized optical scanning tunneling microscopy
No full textCombining scanning tunneling microscopy (STM) and optical excitation has been a major objective in STM for the last 30 years to study light–matter interactions on the atomic scale. The combination with modern pulsed laser systems even made it possible to achieve a temporal resolution down to the femtosecond regime. A promising approach toward a truly localized optical excitation is featured by nanofocusing via an optical antenna spatially separated from the tunnel junction. Until now, these experiments have been limited by thermal instabilities introduced by the laser. This paper presents a versatile solution to this problem by actively coupling the laser and STM, bypassing the vibration-isolation without compromising it. We utilize optical image recognition to monitor the position of the tunneling junction and compensate for any movement of the microscope relative to the laser setup with up to 10 Hz by adjusting the beamline. Our setup stabilizes the focus position with high precision (1 h) and allows for high resolution STM under intense optical excitation with femtosecond pulses
Stanisław Karol Teichmann – an attempt at identification. A supplement To Józef Lewandowski’s reflections on the biography of Krzysztof Kamil Baczyński
No full textOn the grounds of archival and other research, the author puts forward a hypothesis that the father of Stanisław Augustyn Baczyński was not the tailor Zygmunt Baczyński, an 1863 insurrectionist, but Alojzy Stanisław Piotr Teichman vel Teichmann, born in Terebovlia, son of Alojzy and Seweryna Eckhard, administration officer of the general hospital in Lviv. In an attempt to prove his thesis, the author presents family connections and social relations between the Teichman and Baczyński families
Influence of age on biochemical serum parameters in female alpacas – A retrospective study
No full textThe determination of biochemical parameters plays an important role in the veterinary care of alpacas, as it can provide an overview of the integrity and function of various organs and metabolic states. Various reference intervals are available for interpreting biochemical results in alpacas, but physiological variations due to age, sex or season should also be considered. Particularly, information on the influence of age is scarce. In a retrospective study, we examined 17 measured and three calculated biochemical parameters of 21 healthy female alpacas from a research herd over a period of nine years. We found significant positive correlations between age and serum triglycerides, selenium, vitamin E, urea, urea/creatinine ratio, calcium/phosphate ratio and significant negative correlations between age and aspartate aminotransferase activity, calcium and phosphate. However, our results differ to some extent from those found in the literature comparing changes in biochemical parameters between juvenile and adult alpacas. Overall, our data suggest that some biochemical parameters in adult alpacas are subject to physiological changes with age, which should be considered when interpreting laboratory results in this species
Harmonic Oscillator Wave Functions of a Self-Assembled InAs Quantum Dot Measured by Scanning Tunneling Microscopy
No full textIn As quantum dots embedded in an AlAs matrix inside a double barrier resonant tunneling diode are investigated by cross-sectional scanning tunneling spectroscopy. The wave functions of the bound quantum dot states are spatially and energetically resolved. These bound states are known to be responsible for resonant tunneling phenomena in such quantum dot diodes. The wave functions reveal a textbook-like one-dimensional harmonic oscillator behavior showing up to five equidistant energy levels of 80 meV spacing. The derived effective oscillator mass of m = 0.24m(0) is 1 order of magnitude higher than the effective electron mass of bulk In As that we attribute to the influence of the surrounding AlAs matrix. This underlines the importance of the matrix material for tailored QD devices with well-defined properties.DFG [SPP1285]; [DFG-SPP 1285
General transcription factors and subunits of RNA polymerase III: Paralogs for promoter- and cell type-specific transcription in multicellular eukaryotes.
No full textSerum Iron and Its Relationship with Hematologic Parameters in Healthy Female Alpacas at Two Different Ages
No full textIron is an important trace element whose deficiency is associated with anemia, which is a common condition in South American camelids. However, there are only few data available on the physiologic relationships between serum iron and hematologic findings in alpacas. In 81 laboratory diagnostic datasets from 21 clinically healthy alpacas collected over a nine-year period, we recently reported significant positive correlations between iron and hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and eosinophils, and significant negative correlations between iron and mean corpuscular hemoglobin concentration (MCHC), platelets, and neutrophils. For 11 of the animals, datasets were available both at the age of 1 year (young) and at an older age (4–7 years: mature). For young animals, significant positive correlations were found between iron and MCV, MCH, and eosinophils, and significant negative correlations between iron and white blood cells (WBC), red blood cells (RBC), platelets, and neutrophils. In contrast, in mature animals, significant positive correlations were found between iron and monocytes as well as eosinophils. A two-way ANOVA of these 11 animals examining the effects of age, iron, and age*iron revealed significant effects of age on eosinophils, of iron on RBC and MCH, and of age*iron on WBC, RBC, HCT, and lymphocyte-to-monocyte ratio (LMR). Our data show that both age and serum iron have an effect on hematologic parameters in alpacas. Especially in young animals there is a close association between iron and MCH and MCV and neutrophils
Hematologic parameters in female alpacas during age progression: a retrospective study
No full textAlpacas, like all camelids, have elliptical red blood cells (RBCs) in contrast to other mammals. This particular shape is important for increased osmotic resistance and stability. Age-related changes in the RBC count are known in other species, with alterations in both red and white blood cells being described. In alpacas, there are few data on age-related changes, and only a comparison of crias with adult animals. We characterized age-related hematologic changes in a study of 21 female alpacas from a research herd. A total of 87 records of clinically healthy alpacas of different ages were statistically analyzed retrospectively from the hematologic records over a nine-year period. Significant positive correlations of age with hemoglobin (Hb), HCT, MCV, MCH, neutrophils, platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) were found as well as significant negative correlations of age with lymphocytes in addition to lymphocyte-to-monocyte ratio (LMR). A paired comparison of eight older animals in the herd at three different ages also showed significant differences in the parameters Hb, HCT, MCV, MCH, MCHC, lymphocytes, eosinophils and neutrophils. Similar changes in hematologic parameters have been reported in other species and should be taken into account when interpreting hematologic results in alpacas
RNA polymerase III transcription control elements: themes and variations.
No full textEukaryotic genomes are punctuated by a multitude of tiny genetic elements, that share the property of being recognized and transcribed by the RNA polymerase (Pol) III machinery to produce a variety of small, abundant non-protein-coding (nc) RNAs (tRNAs, 5S rRNA, U6 snRNA and many others). The highly selective, efficient and localized action of Pol III at its minute genomic targets is made possible by a handful of cis-acting regulatory elements, located within the transcribed region (where they are bound by the multisubunit assembly factor TFIIIC) and/or upstream of the transcription start site. Most of them participate directly or indirectly in the ultimate recruitment of TFIIIB, a key multiprotein initiation factor able to direct, once assembled, multiple transcription cycles by Pol III. But the peculiar efficiency and selectivity of Pol III transcription also depends on its ability to recognize very simple and precisely positioned termination signals. Studies in the last few years have significantly expanded the set of known Pol III-associated loci in genomes and, concomitantly, have revealed unexpected features of Pol III cis-regulatory elements in terms of variety, function, genomic location and potential contribution to transcriptome complexity. Here we review, in a historical perspective, well established and newly acquired knowledge about Pol III transcription control elements, with the aim of providing a useful reference for future studies of the Pol III system, which we anticipate will be numerous and intriguing for years to come
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