Bicycle rack

A bicycle rack designed to support and lock a bicycle by the bicycle\u27s front center post. Support and lock brackets for individual bicycles are horizontally disposed fork arrangements formed by two joined U-shaped members. Oppositely extending locking brackets allow pairs of bicycles to be conveniently placed along a series of evenly spaced posts and cross-bars

The histone H3K4 demethylase JARID1A directly interacts with haematopoietic transcription factor GATA1 in erythroid cells through its second PHD domain

Chromatin remodelling and transcription factors play important roles in lineage commitment and development through control of gene expression. Activation of selected lineage-specific genes and repression of alternative lineage-affiliated genes results in tightly regulated cell differentiation transcriptional programmes. However, the complex functional and physical interplay between transcription factors and chromatin modifying enzymes remains elusive. Recent evidence has implicated histone demethylases in normal haematopoietic differentiation as well as in malignant haematopoiesis. Here we report an interaction between H3K4 demethylase JARID1A and the haematopoietic-specific master transcription proteins SCL and GATA1 in red blood cells. Specifically, we observe a direct physical contact between GATA1 and the second PHD domain of JARID1A. This interaction has potential implications for normal and malignant haematopoiesis

Different Mechanisms of Calcitonin, Calcitonin Gene-Related Peptide, and Somatostatin Regulation by Glucocorticoids in a Cell Culture of Human Medullary Thyroid Carcinoma

We have employed the TT cell line, a model for the human medullary thyroid carcinoma cell, lo study the regulation of peptide hormone production by glucocorticoids. Complementary DNA probes were used to measure the calcitonin (CT), CT gene-related peptide (CGRP), and somatostatin (SRIF) mRNA levels. Dose-response experiments in serum-free medium showed that dexamethasone (six-day treatment) lowered somatostatin (to 1% of basal) and CGRP mRNA (to 50% of basal) and stimulated CT mRNA (threefold to thirteenfold) with a half-maximal effective concentration of 10−8 M. Time course studies for cells continuously exposed to 10−6 M dexamethasone showed a rapid (within hours) lowering of SRIF mRNA, whereas the effects on CT and CGRP mRNA required six to eight days. These results demonstrate the presence of two mechanisms, transcriptional (somatostatin) and posttranscriptional (the RNA splice decision to make CT or CGRP mRNA). that can be hormonally regulated

Ice Scours in the Sediments of Glacial Lake Iroquois, Prince Edward County, Eastern Ontario

Straight or slightly curved ice scours are found in thin glacilacustrine sediment of eastern Lake Iroquois, especially near the crest of an escarpment in Prince Edward County. They are large (to 3.57 km long and 174 m wide), shallow (about 1 m deep) and oriented in a nearly westerly direction. Irregular ridges of sediment have been pushed up along the sides and at the western end of some scours. Bedrock is near the ground surface, but had little influence on the formation of the scours. Based on their shape, location and pattern, we conclude that the scours were most likely formed in shallow water of the short-lived Sydney phase of Lake Iroquois by lake ice driven by prevailing northeasterly winds from the retreating Laurentide Ice Sheet.On trouve des sillons glaciels, rectilignes ou courbes, dans des sédiments lacustres de l'est du Lac Iroquois, en particulier près du sommet d'un escarpement dans le comté de Prince Edward. Ces sillons sont larges (jusqu'à 3,57 km de longueur et 174 m de largeur), peu profonds (environ 1 m) et orientés vers l'ouest. Des bourrelets irréguliers de sédiments apparaissent en bordure et à l'extrémité ouest de quelques dépressions. Le substratrum affleure presque, mais a eu peu d'influence sur la formation des sillons. En se fondant sur leur forme, leur emplacement et leur agencement, on en conclut que les sillons ont été formés dans les eaux peu profondes du Lac Iroquois au cours de la courte phase de Sydney, par les glaces du lac poussées par les vents dominants du nord-est, en provenance de l'Inlandsis laurentidien alors en retrait.,1EZlOBbIE B0P03Zlbl B HAHOCAX 3AMEP3lilErO HP0KE3CK0r0 03EPA. TPAOCTBO nPMHU 3ZtBAPZl. BOCTOMHbM OHTAPHO. B TOHKHX JieaOBblX HaHOCaX B BOCTOi-lHOH HacTH Hpok-e3Ckoro 03epa ocoôeHHO pa/ioM c rpefiHeM KpyToro ck'JioHa rpa(|)CTBa flpnnu dnsapn MOAHO na6^ioziaTb npSMbie tum cnerka HSBHBaiolilnecn .neaoBbie 6opo3AU. OHM HMeioT fkyibunie pa3Mepw (no 3.57 KM B JWHHy H 174 M B mnpnHyi. MCAKM H opueH TnpoBanbi npenMylilecTBeHHO Ha 3anaa. HepeperyjiapHbie rpefJHH HaHocoB HaxoflflT-CJi no fjoKaM H B 3anaziHbix OKOHLiaHiiax HeKOTopwx 6opo3/j. HecMOTpa Ha TO. MTO nopo/ia HaxoziHTCfi 6^H3KO OT noBepxHocTH rpyHTa. eë B^nflnne Ha (|K>pMnpoBaHHe mix 6opo34 HeBCiHKO. Ha ocHOBaHiin (tjopMbl, pacnano*eHHfl H piicyHKa 5opo3/t /icnaeTC" BUBO/1, MTO OHH. CKOpee BCerO. f)W/lH ClpOpMHpOBaHbl B MeJIKHX BOZiaX MpOKe3CKOrO 03epa BO BpeMfl KopoTkOH (ba3bi Cn/iHeiï nozi B03,aeHCTBi(eM 03ëpnoro j\t>j\a, HaitccetiHoro /lOMHHHpyiOlilHMH CeBepOBOCTOMHhlMH BeTpaMH OT OTcTynaioUJero /laBpenTHitcKoro MaTepnKOBoro neaHHKa

Computer control of a scanning electron microscope for digital image processing of thermal-wave images

Using a recently developed technology called thermal-wave microscopy, NASA Lewis Research Center has developed a computer controlled submicron thermal-wave microscope for the purpose of investigating III-V compound semiconductor devices and materials. This paper describes the system's design and configuration and discusses the hardware and software capabilities. Knowledge of the Concurrent 3200 series computers is needed for a complete understanding of the material presented. However, concepts and procedures are of general interest

Teaching the Grid: Learning Distributed Computing with the M-grid Framework

A classic challenge within Computer Science is to distribute data and processes so as to take advantage of multiple computers tackling a single problem in a simultaneous and coordinated way. This situation arises in a number of different scenarios, including Grid computing which is a secure, service-based architecture for tackling massively parallel problems and creating virtual organizations. Although the Grid seems destined to be an important part of the future computing landscape, it is very difficult to learn how to use as real Grid software requires extensive setting up and complex security processes. M-grid mimics the core features of the Grid, in a much simpler way, enabling the rapid prototyping of distributed applications. We describe m-grid and explore how it may be used to teach foundation Grid computing skills at the Higher Education level and report some of our experiences of deploying it as an exercise within a programming course

Multi-reference approach to the calculation of photoelectron spectra including spin-orbit coupling

X-ray photoelectron spectra provide a wealth of information on the electronic structure. The extraction of molecular details requires adequate theoretical methods, which in case of transition metal complexes has to account for effects due to the multi-configurational and spin-mixed nature of the many-electron wave function. Here, the Restricted Active Space Self-Consistent Field method including spin-orbit coupling is used to cope with this challenge and to calculate valence and core photoelectron spectra. The intensities are estimated within the frameworks of the Dyson orbital formalism and the sudden approximation. Thereby, we utilize an efficient computational algorithm that is based on a biorthonormal basis transformation. The approach is applied to the valence photoionization of the gas phase water molecule and to the core ionization spectrum of the $\text{[Fe(H}_2\text{O)}_6\text{]}^{2+}$ complex. The results show good agreement with the experimental data obtained in this work, whereas the sudden approximation demonstrates distinct deviations from experiments

New data and the hard pomeron

New structure-function data are in excellent agreement with the existence of a hard pomeron, with intercept about 1.4. It gives a very economical description of the data. Having fixed 2 parameters from the data for the real-photon cross section $\sigma^{\gamma p}$, we need just 5 further parameters to fit the data for $F_2(x,Q^2)$ with $x\leq 0.001$. The available data range from $Q^2=0.045$ to 35 GeV$^2$. With guesses consistent with dimensional counting for the $x$ dependences of our three separate terms, the fit extends well to larger $x$ and to $Q^2=5000$ GeV$^2$. With no additional parameters, it gives a good description of data for the charm structure function $F_2^c(x,Q^2)$ from $Q^2=0$ to 130 GeV$^2$. The two pomerons also give a good description of both the $W$ and the $t$ dependence of $\gamma p\to J/\psi p$.Comment: 11 pages, plain tex, with 10 figures embedded using epsf. (Spurious figure removed.

Fast magnetization switching of Stoner particles: A nonlinear dynamics picture

The magnetization reversal of Stoner particles is investigated from the point of view of nonlinear dynamics within the Landau-Lifshitz-Gilbert formulation. The following results are obtained. 1) We clarify that the so-called Stoner-Wohlfarth (SW) limit becomes exact when damping constant is infinitely large. Under the limit, the magnetization moves along the steepest energy descent path. The minimal switching field is the one at which there is only one stable fixed point in the system. 2) For a given magnetic anisotropy, there is a critical value for the damping constant, above which the minimal switching field is the same as that of the SW-limit. 3) We illustrate how fixed points and their basins change under a field along different directions. This change explains well why a non-parallel field gives a smaller minimal switching field and a short switching time. 4) The field of a ballistic magnetization reversal should be along certain direction window in the presence of energy dissipation. The width of the window depends on both of the damping constant and the magnetic anisotropy. The upper and lower bounds of the direction window increase with the damping constant. The window width oscillates with the damping constant for a given magnetic anisotropy. It is zero for both zero and infinite damping. Thus, the perpendicular field configuration widely employed in the current experiments is not the best one since the damping constant in a real system is far from zero.Comment: 10 pages, 9 figures. submitted to PR