bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arf6 recruits the Rac GEF Kalirin to the plasma membrane facilitating Rac activation
Authors: Koo Tae Hyeon , Eipper Betty A , Donaldson Julie G 
Published: July 2007

Abstract

Background
Many studies implicate Arf6 activity in Rac-mediated membrane ruffling and cytoskeletal reorganization. Although Arf6 facilitates the trafficking of Rac1 to the plasma membrane and in many cases Arf6 activation leads to the activation of Rac1, the details of how Arf6 influences Rac function remain to be elucidated.

Results
We demonstrate in binding assays and by co-immunoprecipitation that GDP-bound Arf6 binds to Kalirin5, a Rho family guanine nucleotide exchange factor, through interaction with the spectrin repeat region. In cells, expression of wild type Arf6 recruits spectrin repeat 5 and Kalirin to the plasma membrane and leads to enhanced Kalirin5-induced ruffling. By contrast, expression of an Arf6 mutant that cannot become activated, Arf6 T27N, still recruits spectrin repeat 5 and Kalirin to membranes but inhibits Kalirin5-induced ruffling in HeLa cells. Kalirin5-induced Rac1 activation is increased by the expression of wild type Arf6 and decreased by Arf6T27N. Furthermore, expression of a catalytically-inactive mutant of Kalirin5 inhibits cytoskeletal changes observed in cells expressing EFA6, an Arf6 guanine nucleotide exchange factor that leads to activation of Rac.

Conclusion
We show here with over-expressed proteins that the GDP-bound form of Arf6 can bind to the spectrin repeat regions in Kalirin Rho family GEFs thereby recruiting Kalirin to membranes. Although Kalirin is recruited onto membranes by Arf6-GDP, subsequent Rac activation and membrane ruffling requires Arf6 activation. From these results, we suggest that Arf6 can regulate through its GTPase cycle the activation of Rac.
siRNA screen of the human signaling proteome identifies the PtdIns(3,4,5)P3-mTOR signaling pathway as a primary regulator of transferrin uptake
Authors: Galvez Thierry , Teruel Mary N , Heo Won Do , Jones Joshua T , Kim Man Lyang , Liou Jen , Myers Jason W , Meyer Tobias 
Published: July 2007

Abstract
Background
Iron uptake via endocytosis of iron-transferrin-transferrin receptor complexes is a rate-limiting step for cell growth, viability and proliferation in tumor cells as well as non-transformed cells such as activated lymphocytes. Signaling pathways that regulate transferrin uptake have not yet been identified.

Results
We surveyed the human signaling proteome for regulators that increase or decrease transferrin uptake by screening 1,804 dicer-generated signaling small interfering RNAs using automated quantitative imaging. In addition to known transport proteins, we identified 11 signaling proteins that included a striking signature set for the phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3)-target of rapamycin (mTOR) signaling pathway. We show that the PI3K-mTOR signaling pathway is a positive regulator of transferrin uptake that increases the number of transferrin receptors per endocytic vesicle without affecting endocytosis or recycling rates.

Conclusion
Our study identifies the PtdIns(3,4,5)P3-mTOR signaling pathway as a new regulator of iron-transferrin uptake and serves as a proof-of-concept that targeted RNA interference screens of the signaling proteome provide a powerful and unbiased approach to discover or rank signaling pathways that regulate a particular cell function.
Relationships between Soil and Runoff Phosphorus in Small Alberta Watersheds
Authors: Little Joanne L. , Nolan Sheilah C. , Casson Janna P. , Olson Barry M. 
Published: July 2007

AbstractField‐scale relationships between soil test phosphorus (STP) and flow‐weighted mean concentrations (FWMCs) of dissolved reactive phosphorus (DRP) and total phosphorus (TP) in runoff are essential for modeling phosphorus losses, but are lacking. The objectives of this study were (i) to determine the relationships between soil phosphorus (STP and degree of phosphorus saturation (DPS)) and runoff phosphorus (TP and DRP) from field‐sized catchments under spring snowmelt and summer rainfall conditions, and (ii) to determine whether a variety of depths and spatial representations of STP improved the prediction of phosphorus losses. Runoff was monitored from eight field‐scale microwatersheds (2 to 248 ha) for 3 yr. Soil test phosphorus was determined for three layers (0 to 2.5 cm, 0 to 5 cm, and 0 to 15 cm) in spring and fall and the DPS was determined for the surface layer. Average STP (0 to 15 cm) ranged from 3 to 512 mg kg−1, and DPS (0 to 2.5 cm) ranged from 5 to 91%. Seasonal FWMCs ranged from 0.01 to 7.4 mg L−1 DRP and from 0.1 to 8.0 mg L−1 TP. Strong linear relationships (r2 = 0.87 to 0.89) were found between the site mean STP and the FWMCs of DRP and TP. The relationships had similar extraction coefficients, intercepts, and predictive power among all three soil layers. Extraction coefficients (0.013 to 0.014) were similar to those reported for other Alberta studies, but were greater than those reported for rainfall simulation studies. The curvilinear DPS relationship showed similar predictive ability to STP. The field‐scale STP relationships derived from natural conditions in this study should provide the basis for modeling phosphorus in Alberta.
Interaction and Influence of Two Creeks on Escherichia coli Concentrations of Nearby Beaches: Exploration of Predictability and Mechanisms
Authors: Nevers Meredith B. , Whitman Richard L. , Frick Walter E. , Ge Zhongfu 
Published: July 2007

AbstractThe impact of river outfalls on beach water quality depends on numerous interacting factors. The delivery of contaminants by multiple creeks greatly complicates understanding of the source contributions, especially when pollution might originate up‐ or down‐coast of beaches. We studied two beaches along Lake Michigan that are located between two creek outfalls to determine the hydrometeorologic factors influencing near‐shore microbiologic water quality and the relative impact of the creeks. The creeks continuously delivered water with high concentrations of Escherichia coli to Lake Michigan, and the direction of transport of these bacteria was affected by current direction. Current direction reversals were associated with elevated E. coli concentrations at Central Avenue beach. Rainfall, barometric pressure, wave height, wave period, and creek specific conductance were significantly related to E. coli concentration at the beaches and were the parameters used in predictive models that best described E. coli variation at the two beaches. Multiple inputs to numerous beaches complicates the analysis and understanding of the relative relationship of sources but affords opportunities for showing how these complex creek inputs might interact to yield collective or individual effects on beach water quality.
Manoeuvring and vibration reduction of a flexible spacecraft integrating optimal sliding mode controller and distributed piezoelectric sensors/actuators
Authors: Hu Qinglei , Ma Guangfu 
Published: July 2007

AbstractAfter publication, it was determined that this paper contained an error where Equation (36) cannot be solved because it is constrained by the inequality of Equation (30). To overcome this, we here change the mistake into a static output feedback problem.Equation (29) can be rewritten in a first‐order state‐space form

where

and C̃ = [0 0 Λ 0].The following cost function is to be minimized by the feedback gains Ḡ:

From the above Equation (31), the cost function designed in Equation (32) becomes

where

The optimization problem can be restated as follows:

subject to

where

Note that this kind of constraint optimization problem is a standard static output feedback problem, which may be solved by using the efficient software package LMI Control Toolbox for MATLAB. For space limitation, the details of the derivative process are omitted here.
Natural history of aging in Cornelia de Lange syndrome
Authors: Kline Antonie D. , Grados Marco , Sponseller Paul , Levy Howard P. , Blagowidow Natalie , Schoedel Christianne , Rampolla Joni , Clemens Douglas K. , Krantz Ian , Kimball Amy , Pichard Carmen , Tuchman David 
Published: July 2007

AbstractObservations about the natural history of aging in Cornelia de Lange syndrome (CdLS) are made, based on 49 patients from a multidisciplinary clinic for adolescents and adults. The mean age was 17 years. Although most patients remain small, obesity may develop. Gastroesophageal reflux persists or worsens, and there are early long‐term sequelae, including Barrett esophagus in 10%; other gastrointestinal findings include risk for volvulus, rumination, and chronic constipation. Submucous cleft palate was found in 14%, most undetected before our evaluation. Chronic sinusitis was noted in 39%, often with nasal polyps. Blepharitis improves with age; cataracts and detached retina may occur. Decreased bone density is observed, with occasional fractures. One quarter have leg length discrepancy and 39% scoliosis. Most females have delayed or irregular menses but normal gynecologic exams and pap smears. Benign prostatic hypertrophy occurred in one male prior to 40 years. The phenotype is variable, but there is a distinct pattern of facial changes with aging. Premature gray hair is frequent; two patients had cutis verticis gyrata. Behavioral issues and specific psychiatric diagnoses, including self‐injury, anxiety, attention‐deficit disorder, autistic features, depression, and obsessive‐compulsive behavior, often worsen with age. This work presents some evidence for accelerated aging in CdLS. Of 53% with mutation analysis, 55% demonstrate a detectable mutation in NIPBL or SMC1A. Although no specific genotype–phenotype correlations have been firmly established, individuals with missense mutations in NIPBL and SMC1A appear milder than those with other mutations. Based on these observations, recommendations for clinical management of adults with CdLS are made. © 2007 Wiley‐Liss, Inc.
Challenges of diagnosis in fetal alcohol syndrome and fetal alcohol spectrum disorder in the adult
Authors: Chudley Albert E. , Kilgour Andrea R. , Cranston Meghan , Edwards Michelle 
Published: July 2007

AbstractAdults with fetal alcohol syndrome (FAS) and the subsets of individuals with attenuated phenotype subsumed under the umbrella term of fetal alcohol spectrum disorder (FASD) provide clinicians with a challenge. Compounding this, FASD is different from most genetic syndromes since a specific diagnostic biological test is not available. The diagnosis first needs to be suspected and confirmation requires a diagnostic assessment that is best carried out in the context of a multi‐disciplinary team approach. There is surprisingly little research published on the prevalence, natural history, medical, and social complications relevant to adults with FASD. The evidence that is emerging suggests that this disorder is common, and that services to diagnose and treat these individuals are limited. Adults with FASD have a higher incidence of impairments in social adaptive and executive function, and a higher degree of psychopathology when compared to the general population. The impact of FASD has significant and serious effects on those affected with FASD, their families, and our communities. There is a need for improved access to diagnosis, and more research and evaluation of interventions currently in use. In this paper, we describe the current diagnostic criteria, the differential diagnosis, the prevalence, natural history, the behavioral and mental health consequences, medical and social management issues, and interventions for adults affected with this disorder. © 2007 Wiley‐Liss, Inc.
Sustainable Concepts in Olefin Metathesis
Authors: Clavier Hervé , Grela Karol , Kirschning Andreas , Mauduit Marc , Nolan Steven P. 
Published: July 2007

AbstractRuthenium‐catalyzed olefin metathesis reactions represent an attractive and powerful transformation for the formation of new carbon–carbon double bonds. This area is now quite familiar to most chemists as numerous catalysts are available that enable a plethora of olefin metathesis reactions. Nevertheless, with the exception of uses in polymerization reactions, only a limited number of industrial processes use olefin metathesis. This is mainly due to difficulties associated with removing ruthenium from the final products. In this context, a number of studies have been carried out to develop procedures for the removal of the catalyst or the products of catalyst decomposition, however, none are universally attractive so far. This situation has resulted in tremendous activity in the area dealing with supported or tagged versions of homogeneous catalysts. This Review summarizes the numerous studies focused on developing cleaner ruthenium‐catalyzed metathesis processes.
DNA–Metal Base Pairs
Authors: Clever Guido H. , Kaul Corinna , Carell Thomas 
Published: July 2007

AbstractRecent developments show encouraging results for the use of DNA as a construction material for nanometer‐sized objects. Today, however, DNA‐based molecular nanoarchitectures are constructed with mainly unmodified or at best end‐modified oligonucleotides, thus shifting the development of functionalized DNA structures into the limelight. One of most recent developments in this direction is the substitution of the canonical Watson–Crick base pairs by metal complexes. In this way “metal–base pairs” are created, which could potentially impart magnetic or conductive properties to DNA‐based nanostructures. This review summarizes research which started almost 45 years ago with the investigation of how metal ions interact with unmodified DNA and which recently culminated in the development of artificial ligand‐like nucleobases so far able to coordinate up to ten metal ions inside a single DNA duplex in a programmable fashion.
A query language for discovering semantic associations, Part II: sample queries and query evaluation
Authors: Niemi Timo , Jämsen Janne 
Published: July 2007

AbstractIn our query language introduced in Part I (Niemi & Jämsen, in press) the user can formulate queries to find out (possibly complex) semantic relationships among entities. In this article we demonstrate the usage of our query language and discuss the new applications that it supports. We categorize several query types and give sample queries. The query types are categorized based on whether the entities specified in a query are known or unknown to the user in advance, and whether text information in documents is utilized. Natural language is used to represent the results of queries in order to facilitate correct interpretation by the user. We discuss briefly the issues related to the prototype implementation of the query language and show that an independent operation like Rho (Sheth et al., 2005; Anyanwu & Sheth, 2002, 2003), which presupposes entities of interest to be known in advance, is exceedingly inefficient in emulating the behavior of our query language. The discussion also covers potential problems, and challenges for future work.
Synthesis of Optically Active P‐Chiral and Optically Inactive Oligophosphines
Authors: Morisaki Yasuhiro , Ouchi Yuko , Naka Kensuke , Chujo Yoshiki 
Published: July 2007

AbstractA series of optically active P‐chiral oligophosphines (S,R,R,S)‐2, (S,R,S,S,R,S)‐3, (S,R,S,R,R,S,R,S)‐4, and (S,R,S,R,S,R,R,S,R,S,R,S)‐5 with four, six, eight, and 12 chiral phosphorus atoms, respectively, were successfully synthesized by a step‐by‐step oxidative‐coupling reaction from (S,S)‐1. The corresponding optically inactive oligophosphines 1′–5′ were also prepared. Their properties were characterized by DSC, XRD, and optical‐rotation analyses. While optically active bisphosphine (S,S)‐1 and tetraphosphine (S,R,R,S)‐2 behaved as small molecules, octaphosphine (S,R,S,R,R,S,R,S)‐4 and dodecaphosphine (S,R,S,R,S,R,R,S,R,S,R,S)‐5 exhibited the features of a polymer. Furthermore, DSC and XRD analyses showed that hexaphosphine (S,R,S,S,R,S)‐3 is an intermediate between a small molecule and a polymer. Comparison of optically active oligophosphines 1–5 with the corresponding optically inactive oligophosphines 1′–5′ revealed that the optically active phosphines have higher crystallinity than the optically inactive counterparts. It is considered that the properties of oligophosphines depend on the enantiomeric purity as well as the oligomer chain length.
exo‐Selective Asymmetric Diels–Alder Reaction Catalyzed by Diamine Salts as Organocatalysts
Authors: Kano Taichi , Tanaka Youhei , Maruoka Keiji 
Published: July 2007

AbstractAn organocatalyst formed from a binaphthyl‐substituted diamine and trifluoromethanesulfonic acid exhibited unprecedented levels of exo selectivity in the Diels–Alder reaction of α,β‐unsaturated aldehydes with cyclopentadiene. A novel axially chiral diamine was also designed as an organocatalyst for an asymmetric variant of this reaction, in which the desired cycloadducts were formed with high diastereo‐ and enantioselectivities. The highest diastereoselectivity observed was greater than 20:1 in favor of the exo cycloadduct in the asymmetric Diels–Alder reaction of crotonaldehyde with cyclopentadiene.
The Lewis Acidic Ruthenium‐Complex‐Catalyzed Addition of β‐Diketones to Alcohols and Styrenes Is in Fact Brønsted Acid Catalyzed
Authors: Liu Pei Nian , Zhou Zhong Yuan , Lau Chak Po 
Published: July 2007

AbstractThe perchlorate salt of the dicationic bipy–ruthenium complex cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2]2+ effectively catalyzes addition of β‐diketones to secondary alcohols and styrenes to yield the α‐alkylated β‐diketones. In a catalytic addition reaction of acetylacetone to 1‐phenylethanol, the κ2‐acetylacetonate complex [Ru(6,6′‐Cl2bipy)2(κ2‐acac)]ClO4 was isolated after the catalysis; this complex is readily synthesized by reacting cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2](ClO4)2 with acetylacetone. [Ru(6,6′‐Cl2bipy)2(κ2‐acac)]ClO4 is unreactive toward 1‐phenylethanol in the presence of HClO4; it also fails to catalyze the addition of acetylacetone to 1‐phenylethanol. On the basis of these observations, it is proposed and confirmed by independent experiments that the catalytic addition of β‐diketones to the secondary alcohols is in fact catalyzed by the Brønsted acid HClO4, which is generated by the reaction of cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2](ClO4)2 with the β‐diketone.
Molecular recognition of sugars by lanthanide (III) complexes of a conjugate of N, N‐bis[2‐[bis[2‐(1, 1‐dimethylethoxy)‐2‐oxoethyl]amino]ethyl]glycine and phenylboronic acid
Authors: Battistini Elisa , Mortillaro Armando , Aime Silvio , Peters Joop A. 
Published: July 2007

AbstractA novel conjugate of phenylboronic acid and an Ln(DTPA) derivative, in which the central acetate pendant arm was replaced by the methylamide of L‐lysine, was synthesized and characterized. The results of a fit of variable 17O NMR data and a 1H NMRD profile show that the water residence lifetime of the Gd(III) complex (150 ns) is shorter than that of the parent compound Gd(DTPA)2− (303 ns). Furthermore, the data suggest that several water molecules in the second coordination sphere of Gd(III) contribute to the relaxivity of the conjugate. The Ln(III) complexes of this conjugate are highly suitable for molecular recognition of sugars. The interaction with various sugars was investigated by 11B NMR spectroscopy. Thanks to the thiourea function that links the phenylboronic acid targeting vector with the DTPA derivative, the interactions are stronger than that of phenylboronic acid itself. In particular, the interaction with N‐propylfructosamine, a model for the glucose residue in glycated human serum albumin (HSA), is very strong. Unfortunately, the complex also shows a rather strong interaction with hexose‐free HSA (KA = 705 ± 300). Copyright © 2007 John Wiley & Sons, Ltd.
Morphological characterization of spinal cord dorsal horn lamina I neurons projecting to the parabrachial nucleus in the rat
Authors: Almarestani L. , Waters S.M. , Krause J.E. , Bennett G.J. , Ribeiro‐da‐Silva A. 
Published: July 2007

AbstractMany Rexed's lamina I neurons are nociceptive and project to the brain. Lamina I projection neurons can be classified as multipolar, fusiform, or pyramidal, based on cell body shape and characteristics of their proximal dendrites in the horizontal plane. There is also evidence that both multipolar and fusiform cells are nociceptive and pyramidal neurons nonnociceptive. In this investigation we identified which types of lamina I neurons belong to the spinoparabrachial tract in the rat and characterized them regarding the presence or absence of neurokinin‐1 receptor (NK‐1r) immunoreactivity. For this, cholera toxin subunit B (CTb), conjugated to a fluorescent marker was injected unilaterally into the parabrachial nucleus. Sections were additionally stained for the detection of NK‐1r immunoreactivity and were examined using fluorescence and confocal microscopy. Serial confocal optical sections and 3D reconstructions were obtained for a considerable number of neurons per animal. Using immunofluorescence, we assessed the proportion of lamina I neurons belonging to the spinoparabrachial (SPB) tract and/or expressing NK‐1r. The relative distribution of neurons belonging to the SPB tract was: 38.7% multipolar, 36.8% fusiform, 22.7% pyramidal, and 1.9% unclassified. Most of the SPB neurons expressing NK‐1r were either multipolar or fusiform. Pyramidal SPB neurons were seldom immunoreactive for NK‐1r, an observation that provides further support to the concept that most lamina I projection neurons of the pyramidal type are nonnociceptive. In addition, our study provides further evidence that these distinct morphological types of neurons differ in their phenotypic properties, but not in their projection patterns. J. Comp. Neurol. 504:287–297, 2007. © 2007 Wiley‐Liss, Inc.
Acute and chronic changes in dorsal horn innervation by primary afferents and descending supraspinal pathways after spinal cord injury
Authors: Kalous Adrianna , Osborne Peregrine B. , Keast Janet R. 
Published: July 2007

AbstractSprouting of peptidergic nociceptive and descending supraspinal projections to the dorsal horn following spinal cord injury (SCI) has been proposed as a mechanism of neuropathic pain. To identify structural changes that could initiate or maintain SCI pain, we used a complete transection model in rats to examine how structural remodeling in the dorsal horn rostral to the lesion relates to distance from injury, laminar region, and duration of injury. The major classes of C‐fiber primary afferents differed greatly in their susceptibility to structural and chemical changes and their ability to undergo plasticity. Peptidergic primary afferents showed a widespread loss throughout the dorsal horn of segments approaching the injury site. Some of this loss may have been due to decreased neuropeptide expression. The reduction in peptidergic fibers was transient, indicating compensatory sprouting and perhaps also increased neuropeptide expression within the cord. Nonpeptidergic afferents expressing GFRα1 were largely unaffected by SCI. In contrast, in GFRα2‐expressing nonpeptidergic afferents SCI caused a permanent loss of dorsal horn innervation. Unexpectedly, GFRα2 was transiently induced throughout deeper laminae but this was not due to upregulation of GFRα2 in dorsal root ganglia. We also observed permanent sprouting of catecholamine terminals of supraspinal origin. This was restricted to the superficial laminae. Our results show that SCI caused a loss of sensory input as well as structural remodeling such that the balance of nociceptive inputs and descending modulation was permanently altered. These changes may contribute to mechanisms rostral to the site of SCI that trigger and maintain neuropathic pain. J. Comp. Neurol. 504:238–253, 2007. © 2007 Wiley‐Liss, Inc.