bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Clr7 and Clr8 Directionality Factors and the Pcu4 Cullin Mediate Heterochromatin Formation in the Fission Yeast Schizosaccharomyces pombe
Authors: Thon Geneviève , Hansen Klavs R , Altes Susagna Padrissa , Sidhu Deepak , Singh Gurjeet , Verhein-Hansen Janne , Bonaduce Michael J , Klar Amar J S 
Published: September 2005

Abstract
Fission yeast heterochromatin is formed at centromeres, telomeres, and in the mating-type region where it mediates the transcriptional silencing of the mat2-P and mat3-M donor loci and the directionality of mating-type switching. We conducted a genetic screen for directionality mutants. This screen revealed the essential role of two previously uncharacterized factors, Clr7 and Clr8, in heterochromatin formation. Clr7 and Clr8 are required for localization of the Swi6 chromodomain protein and for histone H3 lysine 9 methylation, thereby influencing not only mating-type switching but also transcriptional silencing in all previously characterized heterochromatic regions, chromosome segregation, and meiotic recombination in the mating-type region. We present evidence for physical interactions between Clr7 and the mating-type region and between Clr7 and the S. pombe cullin Pcu4, indicating that a complex containing these proteins mediates an early step in heterochromatin formation and implying a role for ubiquitination at this early stage prior to the action of the Clr4 histone methyl-transferase. Like Clr7 and Clr8, Pcu4 is required for histone H3 lysine 9 methylation, and bidirectional centromeric transcripts that are normally processed into siRNA by the RNAi machinery in wild-type cells are easily detected in cells lacking Clr7, Clr8, or Pcu4. Another physical interaction, between the nucleoporin Nup189 and Clr8, suggests that Clr8 might be involved in tethering heterochromatic regions to the nuclear envelope by association with the nuclear-pore complex.
A Selfish Gene Governing Pollen-Pistil Compatibility Confers Reproductive Isolation Between Maize Relatives
Authors: Kermicle Jerry L 
Published: September 2005

Abstract
Some populations of maize's closest relatives, the annual teosintes of Mexico, are unreceptive to maize pollen. When present in the pistil (silk and ovary) a number of maize genes discriminate against or exclude pollen not carrying the same allele. An analogous gene Tcb1-s was found in some teosinte populations but not in sympatric or parapatric maize. It was polymorphic among populations of teosinte growing wild, but regularly present in populations growing in intimate association with maize as a weed. Introduction of Tcb1-s into maize substantially to fully restored compatibility with Tcb1-s carrying teosintes. Although Tcb1-s pollen can fertilize tcb1 tcb1 maize, it is at a competitive disadvantage relative to tcb1 pollen. Hence, the influence of Tcb1-s on crossability is bidirectional. In the absence of maize, Tcb1-s can increase in teosinte populations without improving their fitness. In the presence of maize, Tcb1-s appears to have been co-opted to provide reproductive isolation for adaptation to a cultivated habitat.
Comparisons of Estimated Economic Burdens due to Insufficient Solar Ultraviolet Irradiance and Vitamin D and Excess Solar UV Irradiance for the United States
Authors: Grant William B. , Garland Cedric F. , Holick Michael F. 
Published: September 2005

ABSTRACTVitamin D sufficiency is required for optimal health, and solar ultraviolet B (UVB) irradiance is an important source of vitamin D. UVB and/or vitamin D have been found in observational studies to be associated with reduced risk for over a dozen forms of cancer, multiple sclerosis, osteoporotic fractures, and several other diseases. On the other hand, excess UV irradiance is associated with adverse health outcomes such as cataracts, melanoma, and nonmelanoma skin cancer. Ecologic analyses are used to estimate the fraction of cancer mortality, multiple sclerosis prevalence, and cataract formation that can be prevented or delayed. Estimates from the literature are used for other diseases attributed to excess UV irradiation, additional cancer estimates, and osteoporotic fractures. These results are used to estimate the economic burdens of insufficient UVB irradiation and vitamin D insufficiency as well as excess UV irradiation in the United States for these diseases and conditions. We estimate that 50 000–63 000 individuals in the United States and 19 000–25 000 in the UK die prematurely from cancer annually due to insufficient vitamin D. The U.S. economic burden due to vitamin D insufficiency from inadequate exposure to solar UVB irradiance, diet, and supplements was estimated at $40–56 billion in 2004, whereas the economic burden for excess UV irradiance was estimated at $6–7 billion. These results suggest that increased vitamin D through UVB irradiance, fortification of food, and supplementation could reduce the health care burden in the United States, UK, and elsewhere. Further research is required to confirm these estimates.
Taste, Smell and Sound On the Street in Chinatown and Little Italy
Authors: Fernando Nisha 
Published: September 2005

AbstractLike magnets, Chinatown and Little Italy, in Manhattan, attract New Yorkers and tourists alike, who come to eat and browse. The sale of food from street vendors, restaurants, cafés and specialist shops encourages a dynamic street life. Despite the commercial success and headlining in guide books of these districts, city officials the world over regard street vendors as disruptive and unsanitary. Nisha Fernando argues on their behalf, evoking the distinctive sensory experiences they afford.
Urban Agriculture: Small, Medium, Large
Authors: Doron Gil 
Published: September 2005

AbstractCould urban agriculture be the next design revolution? Gil Doron explains how horticulture, a subject that has until now remained remote from the concerns of contemporary architects, is ripe with potential, bringing with it many ecological, economic and social benefits for the city dweller. He also points out that at all levels, whether at the scale of window boxes, balconies or roof gardens, or on the scale of full‐blown farms, vegetation and agriculture exist in most cities in the world right underneath our noses.
What's Eating Manchester? Gastro‐Culture and Urban Regeneration
Authors: Bell David , Binnie Jon 
Published: September 2005

AbstractThe wide array of new gastronomic establishments in Manchester's city centre symbolise its recent urban regeneration, set in motion by the 1996 IRA bomb that obliterated the Arndale Centre. David Bell and Jon Binnie describe the powerful political forces that lie behind this development, and the variety of eating spaces that it has generated, from the Printworks, an entertainment mall in the commercial retail heart, to the Boho shabby chic of the venues in the Northern Quarter.
Fawood Children's Centre
Authors: Melvin Jeremy 
Published: September 2005

AbstractJeremy Melvin visits the Fawood Children's Centre on the Stonebridge Estate in northwest London and discovers how Alsop and Partners have creatively worked within the bounds of policy to produce a building with an exhilarating choice of recycled materials that gives children back the freedom to play in an exciting environment without wrapping them up in cotton wool.
On large structures and turbulent mixing in confined mixing layers under forcing
Authors: Wang G. R. 
Published: September 2005

AbstractNew phenomena have been observed experimentally in a novel rapid mixing process, where a confined mixing layer in a pipe is periodically forced, especially under strong forcing. In the confined configuration without forcing, there are two incommensurable peaks in the scalar power spectrum: one corresponds to the well‐known Kelvin–Helmholtz instability, but the other is not known, having a narrow‐frequency band around a nearly constant frequency that is independent of the mean flow velocity. With strong forcing within the narrow‐frequency band, the spreading angle of the mixing layer is not restrained by the well‐known saturation phenomenon, but could even achieve a quasi‐ 180 ° immediately downstream of the trailing edge, exhibiting an extraordinarily fast mixing. The mixing layer not only biases to the low‐speed side as the conventional mixing layer does, it could also be symmetric to the splitterplate and even bias to the high‐speed side. These phenomena can be observed only when the forcing is within the narrow‐frequency band. We also find that the streamwise vortices, which result from interaction between the primary vorticity and the vorticity originating from the streamwise corner flow between the splitterplate and sidewall immediately downstream of the trailing edge of the splitterplate, could play an important role for these new observations. These streamwise vortices are very sensitive to initial periodic forcing at the narrow‐frequency band and amplify very fast. The results indicate that the confined mixing layer in a pipe is a very interesting flow. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Utilization of screening mammography in New Hampshire
Authors: Carney Patricia A. , Goodrich Martha E. , MacKenzie Todd , Weiss Julia E. , Poplack Steven P. , Wells Wendy S. , Titus‐Ernstoff Linda 
Published: September 2005

AbstractBACKGROUNDThe objective of screening mammography is to identify breast carcinoma early, which requires routine screening. Although self‐report data indicate that screening utilization is high, the results of this population‐based assessment indicated that utilization is lower than reported previously.METHODSThe authors compared New Hampshire population data from the 2000 Census with clinical encounter data for the corresponding time obtained from the New Hampshire Mammography Network, a mammography registry that captures approximately 90% of the mammograms performed in participating New Hampshire facilities.RESULTSThe results showed that approximately 36% of New Hampshire women either never had a mammogram or had not had a mammogram in > 27 months (irregular screenees), and older women (80 yrs and older) were less likely to be screened (79% unscreened/underscreened) compared with younger women (ages 40–69 yrs; 28–32% unscreened/underscreened). Of the screened women, 44% were adhering to an interval of 14 months, and 21% were adhering within 15 months and 26 months. The remaining 35% of the women had 1 or 2 mammograms and did not return within 27 months.CONCLUSIONSRoutine mammography screening may be occurring less often than believed when survey data alone are used. An important, compelling concern is the reason women had one or two mammograms only and then did not return for additional screening. This area deserves additional research. Cancer 2005. © 2005 American Cancer Society.
A Comparative Study of Cr2O3 Thin Films Obtained by MOCVD using Three Different Precursors
Authors: Carta G. , Natali M. , Rossetto G. , Zanella P. , Salmaso G. , Restello S. , Rigato V. , Kaciulis S. , Mezzi A. 
Published: September 2005

AbstractThin films of chromia (Cr2O3) for anti‐wear protection were grown by metal‐organic (MO)CVD on AISI 304 stainless steel, soda‐lime glass, and (001) silicon substrates. The structural, morphological, and chemical compositions were compared for films grown by using three different, commercial, organochromium compounds; Cr(CO)6 (1), Cr(III) (hexafluoroacetylacetonate) (2), and tris(2,2,6,6‐tetra‐methyl‐3,5‐heptanedionato) chromium (III) (3). The depositions were performed using a hot‐wall reactor at 500 °C, under 3 torr, using N2 as the carrier gas and O2 mixed with water vapor as the reactant gas. The films were analyzed by X‐ray diffraction (XRD), atomic force microscopy (AFM), Rutherford backscattering (RBS), nuclear reaction analysis (NRA), elastic recoil detection (ERD), X‐ray photoelectron spectroscopy (XPS), and Fourier‐transform infrared (FTIR) spectroscopy. The films grown with all three precursors on all three substrates were crystalline with hexagonal Cr2O3 eskalonite structure. FTIR and XPS measurements confirmed the XRD results, showing IR absorption bands characteristic of Cr2O3 and an oxidation state +3 of chromium. The highest growth rate was obtained with precursor (1) (20 nm min–1). Films grown with (1) on stainless steel were analyzed by nanoindentation measurements and scratch test to determine the hardness and the film adhesion.
Mechanism of Ni Film CVD with a Ni(Ktfaa)2 Precursor on a Silicon Substrate
Authors: Bakovets V. V. , Mitkin V. N. , Gelfond N. V. 
Published: September 2005

AbstractThe mechanisms of pyrolysis in He and reduction in H2 of the Ni(ktfaa)2 chelate, and nickel film deposition on silicon substrates are discussed. The Ni films produced by CVD with the Ni(ktfaa)2 chelate as a precursor are clustered. At temperatures of 310 °C and higher pyrolysis of the Ni(ktfaa)2 chelate takes place. The hydrogen atmosphere provides a decrease in the reaction temperature to 242 °C. A decrease of the reduction temperature of the Ni(ktfaa)2 chelate on silicon substrates can take place if the OH groups have been adsorbed on the surface. The mechanisms of the chelate decomposition and film deposition define structure, morphology, and adhesion properties of the metallic nickel films. At temperatures higher than 310 °C the carbon‐containing by‐products are incorporated into the deposited Ni phase. The chemical activation of the silicon surface by prior metal atom introduction creates good adhesion and uniformity of nickel films deposited from the Ni(ktfaa)2 precursor.
One‐Dimensional Oxalato‐Bridged Metal(II) Complexes with 4‐Amino‐1,2,4‐triazole as Apical Ligand
Authors: García‐Couceiro Urko , Castillo Oscar , Luque Antonio , García‐Terán Juan P. , Beobide Garikoitz , Román Pascual 
Published: September 2005

AbstractThe synthesis, chemical characterization, thermal behavior and magnetic properties of six new one‐dimensional oxalato‐bridged metal(II) complexes of formula [M(μ‐ox)(4atr)2]n [MII = Cu (1), Ni (2), Co (3), Zn (4), Fe(5)] and [Cd(μ‐ox)(4atr)2(H2O)]n (6) (ox = oxalato dianion, 4atr = 4‐amino‐1,2,4‐triazole) are reported. The crystal structures of 1 and 6 have been solved by single‐crystal X‐ray diffraction, whereas the remaining compounds have been studied by means of X‐ray powder diffraction methods. Compounds 1–5 are isomorphous and crystallize in the triclinic space group P1¯ with unit cell parameters for 1 of a = 5.538(1) Å, b = 7.663(1) Å, c = 7.711(2) Å, α = 62.21(1)°, β = 73.91(1)°, γ = 86.11(1)°, and Z = 1. The crystal structures are comprised of one‐dimensional linear chains in which the trans‐[M(4atr)2]2+ units are sequentially bridged by bis(bidentate) oxalato ligands, resulting in an octahedral O4N2 donor set. Cryomagnetic susceptibility measurements show the occurrence of antiferromagnetic intrachain interactions for 2, 3, and 5, whereas compound 1 exhibits a weak ferromagnetic coupling in agreement with the out‐of‐plane exchange pathway involved. The magnetic behavior of 1 and 2 is analyzed and discussed in the light of the available magneto‐structural data for analogous systems. CdII complex crystallizes in the monoclinic space group C2/c with unit cell parameters of a = 16.128(2) Å, b = 6.757(1) Å, c = 11.580(2) Å, β = 104.46(1)°, and Z = 4. Its crystal structure contains one‐dimensional chains in which metal centers are heptacoodinated to four oxygen atoms from two symmetry‐related bis(bidentate) oxalato bridges, two endocyclic nitrogen atoms of trans‐coordinated triazole ligands and one water molecule, to give a CdO4OwN2 pentagonal‐bipyramidal geometry. Thermoanalytical and variable‐temperature X‐ray powder diffraction analyzes show that compound 6 undergoes a reversible dehydration–hydration process in which the anhydrous residue crystallizes with a different crystal lattice retaining the dimensionality of the oxalato–metal framework. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Luminescent Properties of Novel Europium(III) Heterocyclic β‐Diketone Complexes with Lewis Bases: Structural Analysis Using the Sparkle/AM1 Model
Authors: Pavithran Rani , Reddy M. L. P. , Junior Severino A. , Freire Ricardo O. , Rocha Gerd B. , Lima Patricia P. 
Published: September 2005

AbstractTris(β‐diketonato)europium(III) complexes of general formula [Eu(TPI)3·L], with chelating ligands such as 3‐phenyl‐4‐(4‐toluoyl)‐5‐isoxazolone (HTPI) and adduct‐forming reagents [L = H2O, tri‐n‐octylphosphane oxide (TOPO), triphenylphosphane oxide (TPhPO), 1,10‐phenanthroline], have been synthesized and characterized by elemental analysis and FT‐IR, 1H NMR, and photoluminescence spectroscopy. The coordination geometries of the complexes were calculated using the Sparkle/AM1 (Sparkle model for the calculation of lanthanide complexes within the Austin model 1) model. The ligand–Eu3+ energy‐transfer rates were calculated using a model of intramolecular energy transfer in lanthanide coordination complexes reported in the literature. The room‐temperature PL spectra of the europium(III) complexes are composed of the typical Eu3+ red emission, assigned to transitions between the first excited state (5D0) and the multiplet (7F0–4). The results clearly show that the substitution of water molecules by TOPO leads to greatly enhanced quantum yields (i.e., 1.3 % vs. 49.5 %) and longer 5D0 lifetimes (220 vs. 980 μs). This can be ascribed to a more efficient ligand‐to‐metal energy transfer and a less efficient nonradiative 5D0 relaxation process. The theoretical quantum yields are in good agreement with the experimental quantum yields, which highlights that the present theoretical approach can be a powerful tool for the a priori design of highly luminescent lanthanide complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Homo‐ and Heteroduplex Complexes Containing Terpyridine‐Type Ligands and Zn2+
Authors: Dumitru Florina , Petit Eddy , van der Lee Arie , Barboiu Mihail 
Published: September 2005

AbstractWe describe a study of the equilibrium binding of Zn2+ to binary mixtures of tridentate terpy‐type ligands 1–3, which leads to the formation of a dynamic mixture of homo (4–6) and hetero (7–9) coordination compounds. We report the crystal structures of five such complexes (4, 5, 7–9) which assemble into complementary duplex compounds that further self‐organize into double helical‐ or lamellar‐type architectures in the solid state. The ligand exchange between homoduplex complexes in solution leads to the preferential formation of the heteroduplex complexes. As might be expected, these processes display a statistical distribution of homoduplex:heteroduplex:homoduplex complexes of 1:2:1 for the mixtures resulting from 4:6 and 5:6 ligands. However, complex 8 is preferred in a 4:5 mixture which presents a composition of 1:4:1 (amplification factor of about 33 %). The X‐ray structural determinations of selected single crystals resulting from the stoichiometric mixtures of homoduplex complexes show unique heteroduplex superstructures 7–9 in the solid state. The present results present the solid‐state structures of homo‐ and heterocomplexes resulting from terpyridine‐type ligands 1–3 and Zn2+ metal ions. The heteroduplex Zn2+ complexes 7–9 are quantitatively crystallized in the solid state by statistical (7, 9) and structural (8) driven selection in solution from a binary mixture of the terpyridine‐type complexes and then trapped by crystallization in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Highly Selective C‐Silylation of Fatty Acid Methyl Esters
Authors: El Kadib Abdelkrim , Asgatay Saadia , Delpech Fabien , Castel Annie , Rivière Pierre 
Published: September 2005

AbstractNew silylated saturated and unsaturated fatty acid methyl esters (FAMEs) possessing a hydrophobic frame and a hydrophilic core were prepared. C‐silylations of the ester group were achieved either by treating FAMEs with various alkyl‐ and chlorosilyl triflates or by subjecting various chlorosilanes to reaction with the corresponding FAME lithium enolates. Both routes led to the exclusive formation of one isomer identified as the C‐silylated form on the basis of the analytical results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Regio‐ and Diastereoselective Conjugate Addition to 4,4‐Dimethylcyclohexadienones
Authors: Giomi Donatella , Piacenti Michela , Brandi Alberto 
Published: September 2005

AbstractConjugate addition of vinyl cuprate and dimethyl malonate to 4,4‐dimethylcyclohexa‐2,5‐dienones has allowed facile access to mono‐ and bis‐adducts in satisfactory yields. While the high diastereoselectivity of such processes to afford trans‐bis‐adducts was predictable, an unprecedented regioselectivity was observed with 2,4,4‐trimethylcyclohexa‐2,5‐dienone, with the first addition occurring exclusively at the C‐5 carbon atom (distal from the methyl group) and with the second addition of a bulky nucleophile such as dimethyl malonate even prevented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Postfire full stress–strain response of fire‐damaged concrete
Authors: Nassif Ayman 
Published: September 2005

AbstractThis paper reports experimental data establishing the postfire full stress–strain response of fire‐affected concrete. Such data are useful in situations when redesign of fire‐damaged concrete elements is considered.Heating was carried out to various temperatures in the range 217–470°C. Cooling was carried out either by quenching or in air. The postfire strain at ultimate stress significantly increased after heating to temperatures higher than 320°C. Quenching seems to aggravate the loss in compressive strength and further increase the strain at ultimate stress. Quenching involved spraying the heated concrete with tap water for 5 min. It is evident that knowledge of maximum temperature of exposure alone is not sufficient for estimation of the postfire stress–strain relationship. Other characteristics of exposure such as method of cooling are also important in evaluating the modification in the structural behaviour of fire‐affected concrete. Copyright © 2005 John Wiley & Sons, Ltd.
Lipopolysaccharide sensitizes microglia toward Ca2+‐induced cell death: Mode of cell death shifts from apoptosis to necrosis
Authors: Nagano Takayuki , Kimura Shinya H. , Takai Eri , Matsuda Toshio , Takemura Motohiko 
Published: September 2005

AbstractLittle is known about the effect of microglial activation on cell death. This study examines the effects of lipopolysaccharide (LPS) and interferon‐γ (IFN‐γ), triggers of microglial activation, on cell death induced by several agents in cultured rat microglia. For comparison, the effect of LPS on cell death is also examined in cultured astrocytes. LPS or IFN‐γ enhanced cell death induced by thapsigargin or ionomycin, an agent that increases intracellular Ca2+ concentration, although LPS or IFN‐γ alone did not affect cell viability. Thapsigargin or ionomycin induced apoptosis in LPS‐untreated microglia, while they induced necrosis in LPS‐treated microglia, which were partially reversed by O,O′‐bis(2‐aminophenyl)ethyleneglycol‐N,N,N′,N′‐tetraacetic acid tetraacetoxymethyl ester (BAPTA‐AM, an intracellular Ca2+ chelator). In contrast, LPS treatment did not affect tunicamycin‐ or staurosporine‐induced apoptosis, while it inhibited S‐nitroso‐N‐acetylpenicillamine‐induced apoptosis. The effect of LPS on thapsigargin or ionomycin‐induced apoptosis was not observed in astrocytes. These results indicate that microglial activation sensitizes the cells toward cell death induced by the change in intracellular Ca2+ concentration and shifts the mode of cell death from apoptosis to necrosis. © 2005 Wiley‐Liss, Inc.