bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-dimensional gel analysis of the heat-shock response in marine snails(genusTegula): interspecific variation in protein expression and acclimation ability
Authors: Tomanek Lars 
Published: August 2005

SUMMARYThe degree to which temperature acclimation modifies the acute synthesis of the entire heat-shock protein (Hsp) complement is still unknown, but it may constitute an important mechanism for understanding the differences in acclimation ability among closely related ectothermic species that occupy widely varying thermal environments. In general, eurythermal (heat-tolerant)species modify physiological function in response to an increase in acclimation temperature to a greater extent than stenothermal (heat-sensitive)species. In the present work I used 35S-labelled amino acids and two-dimensional gel electrophoresis to test this assumption for how acclimation affects acute Hsp expression (referred to as phenotypic plasticity) in two heat-sensitive, low-intertidal to subtidal zone turban snails, Tegula brunnea and T. montereyi, in comparison to a heat-tolerant, mid- to low-intertidal zone congener, T. funebralis. I was able (i) to detect the synthesis of over 30 proteins in gill tissue,primarily in the 70 kDa range, in response to an increase in temperature(13°C, 24°C, 27°C and 30°C), (ii) to assess the effect of acclimation (13°C vs 22°C) on acute Hsp synthesis, and (iii)to compare this effect among the three Tegula congeners. After increasing acclimation temperature from 13°C to 22°C, synthesis of the most highly expressed Hsps decreased more in T. brunnea and T. montereyi than in T. funebralis. Two highly expressed proteins of molecular mass 71 and 74 kDa, however, were also synthesized constitutively at 13°C and changed with increasing acclimation temperature in all three species. Although similar in phenotypic plasticity, T. brunnea and T. montereyi synthesized either a 76 or a 72 kDa cluster of proteins,respectively, and differed in how acclimation affected the acute synthesis of several 77 kDa proteins. Thus, in Tegula, the effect of acclimation on Hsp expression is (i) Hsp-specific, (ii) dependent on a protein's expression pattern (constitutive and inducible vs only inducible),(iii) and is actually limited in the more eurythermal mid- to low-intertidal congener. These results contradict the general assumption that greater heat tolerance correlates with an increased ability to modify physiological function in response to acclimation.
Tracing heme in a living cell: hemoglobin degradation and heme traffic in digest cells of the cattle tickBoophilus microplus
Authors: Lara F. A. , Lins U. , Bechara G. H. , Oliveira P. L. 
Published: August 2005

SUMMARYHeme is present in all cells, acting as a cofactor in essential metabolic pathways such as respiration and photosynthesis. Moreover, both heme and its degradation products, CO, iron and biliverdin, have been ascribed important signaling roles. However, limited knowledge is available on the intracellular pathways involved in the flux of heme between different cell compartments. The cattle tick Boophilus microplus ingests 100 times its own mass in blood. The digest cells of the midgut endocytose blood components and huge amounts of heme are released during hemoglobin digestion. Most of this heme is detoxified by accumulation into a specialized organelle, the hemosome.We followed the fate of hemoglobin and albumin in primary cultures of digest cells by incubation with hemoglobin and albumin labeled with rhodamine. Uptake of hemoglobin by digest cells was inhibited by unlabeled globin,suggesting the presence of receptor-mediated endocytosis. After endocytosis,hemoglobin was observed inside large digestive vesicles. Albumin was exclusively associated with a population of small acidic vesicles, and an excess of unlabeled albumin did not inhibit its uptake. The intracellular pathway of the heme moiety of hemoglobin was specifically monitored using Palladium–mesoporphyrin IX (Pd-mP) as a fluorescent heme analog. When pulse and chase experiments were performed using digest cells incubated with Pd-mP bound to globin (Pd-mP-globin), strong yellow fluorescence was found in large digestive vesicles 4 h after the pulse. By 8 h, the emission of Pd-mP was red-shifted and more evident in the cytoplasm, and at 12 h most of the fluorescence was concentrated inside the hemosomes and had turned green. After 48 h, the Pd-mP signal was exclusively found in hemosomes. In methanol, Pd-mP showed maximal emission at 550 nm, exhibiting a red-shift to 665 nm when bound to proteins in vitro.The red emission in the cytosol and at the boundary of hemosomes suggests the presence of heme-binding proteins, probably involved in transport of heme to the hemosome. The existence of an intracellular heme shuttle from the digestive vesicle to the hemosome acting as a detoxification mechanism should be regarded as a major adaptation of ticks to a blood-feeding way of life. To our knowledge, this is the first direct observation of intracellular transport of heme in a living eukaryotic cell. A similar approach, using Pd-mP fluorescence, could be applied to study heme intracellular metabolism in other cell types.
Behavioural discrimination of polarized light in the damselfishChromis viridis(family Pomacentridae)
Authors: Mussi Martina , Haimberger Theodore J. , Hawryshyn Craig W. 
Published: August 2005

SUMMARYIn this study, we demonstrate the capacity for damselfish (green chromis, Chromis viridis) to discriminate between different e-vector orientations of ultraviolet polarized light. We examined the ability of green chromis to resolve small differences in e-vector orientation of ultraviolet polarized light. Fish were successfully trained to swim towards an e-vector orientation of polarized light using a behavioural chamber. C. viridis was able to discriminate between the horizontal and the vertical plane of ultraviolet polarized light independent of brightness content of the stimuli. However, e-vector discrimination capability disappeared when the ultraviolet portion of the light stimuli was removed, indicating that the presence of ultraviolet light was critical for e-vector discrimination. Fish could also distinguish between relatively small e-vector orientations of ultraviolet polarized light. Functional implications for high e-vector discriminative capabilities could be used in functional domains such as feeding and communication.
Cardiorespiratory adjustments of homing pigeons to steady wind tunnel flight
Authors: Peters Grant W. , Steiner Dee A. , Rigoni Jason A. , Mascilli Alexia D. , Schnepp Robert W. , Thomas Steven P. 
Published: August 2005

SUMMARYWe made detailed cardiorespiratory measurements from homing pigeons during quiet rest and steady wind tunnel flight. Our pigeons satisfied their 17.4-fold increase in oxygen consumption during flight with a 7.4-fold increase in cardiac output (Q̇) and a 2.4-fold increase in blood oxygen extraction. Q̇ was increased primarily by increasing heart rate sixfold. Comparisons between our study and those from the only other detailed cardiorespiratory study on flying birds reveal a number of similarities and important differences. Although the avian allometric equations from this earlier study accurately predicted the flight Q̇ of our pigeons, this was primarily due to due to compensating discrepancies in their heart rate and stroke volume predictions. Additionally, the measured heart mass(MH)-specific Q̇(Q̇/MH) of our pigeons during wind tunnel flight was about 22% lower than the estimated value. Compared to running mammals in previous studies, the 1.65-fold Q̇ of our pigeons is consistent with their larger heart mass.
Computer simulations of high-pass filtering in zebrafish larval muscle fibres
Authors: Buckingham Steven D. , Ali Declan W. 
Published: August 2005

SUMMARY
Larval somatic muscle of the zebrafish, Danio rerio, like that of some other organisms, responds to a sustained depolarization with one, and only one, action potential. Here, we report computer simulations, using the NEURON simulation programme, of sodium and potassium currents of somatic muscle of larval Danio rerio to investigate their possible contribution to once-only firing. Our computer model incorporated simulated sodium and potassium ion channels based on steady-state and kinetic parameters derived from a recent electrophysiological study. The model responded to sustained depolarizations with a single action potential at all levels of depolarization above threshold. By varying several parameters of the sodium and potassium currents systematically, the minimum changes necessary to produce repetitive firing were found to be a positive shift in the half-inactivation and a negative shift in the half-activation potentials for the sodium current, accompanied by a slowing of the rate of inactivation to half of the experimentally observed values. This suggests that once-only spiking can be attributed to the steady-state values of activation and inactivation of the sodium current, along with a slower rate of inactivation. Mapping of the resultant firing properties against steady-state and kinetic ion channel parameters revealed a high safety factor for once-only firing and showed that the time constant of inactivation of the sodium current was the key determinant of once-only or repetitive firing. The rapidly inactivating potassium current does not influence once-only firing or the maximum rate of firing in response to periodic excitation in these simulations. Although a contribution of other currents to produce once-only firing has not been excluded, this model suggests that the properties of the sodium current are sufficient to account for once-only firing.
Design of Functional Molecular Crystals by Controlling Intermolecular Interactions
Authors: Inabe Tamotsu 
Published: August 2005

Abstract
In this account, two representative approaches toward the control of molecular arrangements in molecular crystals are introduced, especially for π-radicals. One is “π–π stacking structure modification of macrocyclic π-ligand complexes”, in which the interaction is modified by simply introducing axial ligands. By this method, a number of conductors with various π–π stacking structures have been obtained. The other is “design of functional crystals utilizing hydrogen bonds”, in which anions with strong self-assembling ability are used for the formation of anion networks. If the interaction between the anions is stronger than that between π-radical cations, the cations are expected to be packed in the space provided by the networks with peculiar assembly formations that differ from those inherently preferable for the cations. The arrangement of π-radicals is directly related to the electronic functionalities of the crystal, and its control is crucial for the design of the specific electronic functionalities.
Formation of α- and β-Keggin-Type [PW12O40]3− Complexes in Aqueous Media
Authors: Himeno Sadayuki , Takamoto Masayo , Ueda Tadaharu 
Published: August 2005

Abstract
The formation process of the α- and β-Keggin-type [PW12O40]3− complexes was investigated in an aqueous 50 mM (M = mol dm−3) W(VI)–5.0 mM P(V) system. The 31P NMR study confirmed the formation of A-α-[PW9O34]9−, A-β-[PW9O34]9−, α-[PW11O39]7−, and β1-[PW11O39]7− on acidification of an alkaline solution of WO42− and HPO42− to pH 7.5 or below. An isomeric mixture of α- and β-[PW12O40]3− was obtained on further acidification of such solutions containing both α- and β-type lacunary complexes to pH 1 or below. On the other hand, heating of the W(VI)–P(V) system caused A-α-[PW9O34]9−, A-β-[PW9O34]9−, and β1-[PW11O39]7− to disappear completely, leaving α-[PW11O39]7−. Acidification of the α-[PW11O39]7− solution produced only α-[PW12O40]3−.
Total Synthesis of Bistratamides G and H from Various Kinds of ΔAla and ΔAbu-Containing Oligopeptides
Authors: Yonezawa Yasuchika , Tani Naoki , Shin Chung-gi 
Published: August 2005

Abstract
The total synthesis of naturally occurring bistratamides G (1) and H (2) from various kinds of dehydrooligopeptides is described. First of all, the promising building blocks of 1 and 2: N-{2-[(S)-1-(N-benzyloxycarbonyl)amino-2-methylpropyl]oxazole (4)- and N-{2-[(S)-1-(N-t-butoxycarbonyl)amino-2-methylpropyl]thiazol-4-ylcarbonyl}-l-Val-(S)NH2 (5), and methyl (S)-2-{1-[N-(3-bromo-2-oxopropanoyl)amino-2-methylpropyl]}-5-methyloxazole-4-carboxylate (6), as the left- and right-half components of the linear precursor of 1 and 2, were synthesized. Subsequent thiazolation between 4 or 5 and 6, respectively, followed by deprotection of both N- and O-protecting groups of the two formed linear trisheterocyclic peptides. By final macrocyclization using BOP as condensing agent under high-dilution conditions these peptides gave the expected 1 and 2.
Synthesis and Photoinduced Intermolecular Electronic Acceptor Ability of Pyrazolo[60]fullerenes vs Tetrathiafulvalene
Authors: Delgado Juan Luis , de la Cruz Pilar , López-Arza Vicente , Langa Fernando , Gan Zhenhai , Araki Yasuyuki , Ito Osamu 
Published: August 2005

Abstract
The synthesis of three novel pyrazolo[60]fullerene derivatives containing electron-withdrawing substituents has been described. High solubility in ordinary organic solvents was proved. Their electrochemical properties of pyrazolo[60]fullerenes showed better electron affinity than pristine C60 in the ground state. The nanosecond transient absorption spectra showed clear evidence for photoinduced electron transfer from TTF to the excited triplet state of the pyrazolo[60]fullerenes, in which stronger electron-withdrawing substituents accelerate the rates of the photoinduced electron-transfer, indicating a high electron-acceptor ability of the excited triplet state of pyrazolo[60]fullerenes.
Synthesis and Properties of Alkyl Phosphorylcholine Amphiphiles with a Linear and an Asymmetrically Branched Alkyl Chain
Authors: Kang Eui-Chul , Kataoka Shingo , Kato Kenji 
Published: August 2005

Abstract
Alkyl phosphorylcholine amphiphiles bearing one linear chain and one asymmetrically branched alkyl chain were successfully synthesized using 2-chloro-2-oxo-1,3,2-dioxaphospholane in tetrahydrofuran or ethyl acetate. 1H and 31P NMR studies revealed that the linear alkyl phosphorylcholines (Cn-PC) provide aqueous micelles in D2O and reverse micelles in CDCl3, while the branched alkyl phosphorylcholines (ISOFOLn-PC) give vesicles in D2O. The critical micelle concentrations (CMCs) of Cn-PC were measured by fluorescence dye solubilization methods: the CMCs of C12-PC, C14-PC, C16-PC, and C18-PC were 1.6, 0.38, 0.16, and 0.11 mM, respectively, in water at 25 °C. The critical association concentrations (CACs) of ISOFOL16-PC, ISOFOL20-PC, and ISOFOL24-PC were 0.068, 0.005, and 0.077 mM, respectively, in water at 25 °C. The vesicle size of ISOFOLn-PC in aqueous solution was measured by the dynamic light scattering method. The mean diameter of ISOFOLn-PC vesicles was approximately 30 nm and the size distribution was relatively monodisperse. The ISOFOLn-PC vesicles formed were colloidally stable in water over the period of several weeks.
Heteropoly Blue as a Reaction-Controlled Phase-Transfer Catalyst for the Epoxidation of Olefins
Authors: Mingqiang Li , Xigao Jian 
Published: August 2005

Abstract
A new reaction-controlled phase-transfer catalyst system has been designed and synthesized. In this system, heteropoly blue, [C7H7N(CH3)3]3PMo4O16, is used for the catalytic epoxidation of olefins with H2O2 as the oxidant. In this system, the catalyst not only can be recovered, like heterogeneous catalyst, but also acts as a homogeneous catalyst. The main products are epoxide of olefins and H2O; no co-product forms. The system exhibits high conversion and selectivity as well as excellent catalyst stability. 31P NMR spectra, UV–vis spectra, and infrared spectra are used to analyze the reason for the phase transfer of the catalyst, indicating that the change of structure leads to the formation of reaction-controlled phase-transfer catalyst.
Interactions Among DNA Ligase I, the Flap Endonuclease and Proliferating Cell Nuclear Antigen in the Expansion and Contraction of CAG Repeat Tracts in Yeast
Authors: Refsland Eric W , Livingston Dennis M 
Published: August 2005

Abstract
Among replication mutations that destabilize CAG repeat tracts, mutations of RAD27, encoding the flap endonuclease, and CDC9, encoding DNA ligase I, increase the incidence of repeat tract expansions to the greatest extent. Both enzymes bind to proliferating cell nuclear antigen (PCNA). To understand whether weakening their interactions leads to CAG repeat tract expansions, we have employed alleles named rad27-p and cdc9-p that have orthologous alterations in their respective PCNA interaction peptide (PIP) box. Also, we employed the PCNA allele pol30-90, which has changes within its hydrophobic pocket that interact with the PIP box. All three alleles destabilize a long CAG repeat tract and yield more tract contractions than expansions. Combining rad27-p with cdc9-p increases the expansion frequency above the sum of the numbers recorded in the individual mutants. A similar additive increase in tract expansions occurs in the rad27-p pol30-90 double mutant but not in the cdc9-p pol30-90 double mutant. The frequency of contractions rises in all three double mutants to nearly the same extent. These results suggest that PCNA mediates the entry of the flap endonuclease and DNA ligase I into the process of Okazaki fragment joining, and this ordered entry is necessary to prevent CAG repeat tract expansions.
Genetic Basis of Spectral Tuning in the Violet-Sensitive Visual Pigment of African Clawed Frog, Xenopus laevis
Authors: Takahashi Yusuke , Yokoyama Shozo 
Published: August 2005

Abstract
Ultraviolet (UV) and violet vision in vertebrates is mediated by UV and violet visual pigments that absorb light maximally (λmax) at ∼360 and 390–440 nm, respectively. So far, a total of 11 amino acid sites only in transmembrane (TM) helices I–III are known to be involved in the functional differentiation of these short wavelength-sensitive type 1 (SWS1) pigments. Here, we have constructed chimeric pigments between the violet pigment of African clawed frog (Xenopus laevis) and its ancestral UV pigment. The results show that not only are the absorption spectra of these pigments modulated strongly by amino acids in TM I–VII, but also, for unknown reasons, the overall effect of amino acid changes in TM IV–VII on the λmax-shift is abolished. The spectral tuning of the contemporary frog pigment is explained by amino acid replacements F86M, V91I, T93P, V109A, E113D, L116V, and S118T, in which V91I and V109A are previously unknown, increasing the total number of critical amino acid sites that are involved in the spectral tuning of SWS1 pigments in vertebrates to 13.
Ultraviolet B but Not A Radiation Activates Suppressor B Cells in Draining Lymph Nodes
Authors: Byrne Scott N. , Ahmed Jarin , Halliday Gary M. 
Published: August 2005

ABSTRACTImmunosuppressive doses of solar‐simulated UV radiation activate lymph node B cells that can suppress primary immunity by inhibiting the function of dendritic cells. The aim of this study was to determine the waveband responsible for activation of these suppressor B cells. We exposed C57BL/6 mice to various doses of either UVA or UVB radiation and analyzed the number and activation state of lymph node antigen‐presenting cells (APC). Immunosuppressive doses of UVB but not UVA activated B cells as assessed by major histocompatibility complex II (MHC II) expression and doubled their numbers in draining lymph nodes. Higher doses of UVA that were not immunosuppressive actually suppressed B cell activation. Our results show that UVA and UVB suppress systemic immunity via different mechanisms. Lymph node B cells are activated in response to immunosuppressive doses of UVB but not UVA. Thus, the activation state of lymph node APC appears to be important for UV immunomodulation.
Cover Picture: Ductile‐to‐Brittle Transition in Nanocrystalline Metals (Adv. Mater. 16/2005)
Authors: Li H. , Ebrahimi F. 
Published: August 2005

AbstractUniaxial tensile studies concerning electrodeposited nanocrystalline face‐centered cubic Ni and Ni–Fe alloys are reported on p. 1969 by Ebrahimi and Li. The nanograined metals display a transition in the deformation mechanism at a critical grain size. The cover shows that their fracture surfaces exhibited a ductile‐to‐brittle transition from the “cup–cup” (intragranular, ductile failure, dislocation controlled) (top panels) to “cup–cone” (intergranular, brittle fracture, probably due to breaking of atomic bonds) (bottom panels) characteristics at room temperature across this critical grain size value.
No support for association between the dopamine transporter (DAT1) gene and ADHD
Authors: Langley K. , Turic D. , Peirce T.R. , Mills S. , Van Den Bree M.B. , Owen M.J. , O'Donovan M.C. , Thapar A. 
Published: August 2005

AbstractSeveral groups have reported an association between the 10‐repeat allele of a dopamine transporter (DAT1) 3′UTR VNTR variant and ADHD but the finding has not been universally observed. An association between DAT1 genotype and stimulant medication response has also been reported although again there are conflicting data. We tested the DAT1 3′VNTR and three SNPs in the putative promoter region of DAT1 for association with ADHD in 263 parent‐proband trios. Analyses of genotypes, alleles, and haplotypes were performed using family‐based association methods. Case‐control analysis of the VNTR in 263 cases and 287 controls was also conducted. In addition, we tested for association between the VNTR marker and stimulant medication response. Comparing allele 10 versus all other alleles combined, no significant association was found with ADHD, using FBAT analysis (χ2 = 0.1 (df 1), P = 0.9, (odds ratio (OR) = 1.0, 95% CI 0.8–1.2), and case‐control analysis (χ2 = 0.12 (df 2), P = 0.91). No evidence of association with any of the SNPs in the promoter region was found. Haplotype analysis was also non‐significant (χ2 = 3.93, (df 9) global P = 0.85). Finally, no association was found between the DAT 1 VNTR and response to stimulant medication (χ2 = 1.63 (df 3) P = 0.65). We conclude that the 3′ VNTR and three additional promoter variants in DAT1 do not appear to be associated with ADHD, or response to stimulant mediation in our sample. © 2005 Wiley‐Liss, Inc.