bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prm1 Prevents Contact-Dependent Lysis of Yeast Mating Pairs
Authors: Jin Hui , Carlile Candice , Nolan Scott , Grote Eric 
Published: December 2004

ABSTRACT

Membrane fusion requires localized destabilization of two phospholipid bilayers, but unrestrained membrane destabilization could result in lysis.
prm1
mutant yeast cells have a defect at the plasma membrane fusion stage of mating that typically results in the accumulation of prezygotes that have fingers of membrane-bound cytoplasm projecting from one cell of each pair into its mating partner in the direction of the osmotic gradient between the cells. However, some
prm1
mating pairs fuse successfully whereas the two cells in other
prm1
mating pairs simultaneously lyse. Lysis only occurs if both mating partners are
prm1
mutants. Osmotic stabilization does not protect
prm1
mating pairs from lysis, indicating that lysis is not caused by a cell wall defect.
prm1
mating pairs without functional mitochondria still lyse, ruling out programmed cell death. No excess lysis was found after pheromone treatment of haploid
prm1
cells, and lysis did not occur in mating pairs when
prm1
was combined with the
fus1
and
fus2
mutations to block cell wall remodeling. Furthermore, short (<1 μm) cytoplasmic microfingers indicating the completion of cell wall remodeling appeared immediately before lysis. In combination, these results demonstrate that plasma membrane contact is a prerequisite for lysis. Cytoplasmic microfingers are unlikely to cause lysis since most
prm1
mating pairs with microfingers do not lyse, and microfingers were also detected before fusion in some wild-type mating pairs. The lysis of
prm1
mutant mating pairs suggests that the Prm1 protein stabilizes the membrane fusion event of yeast mating.
New Insights into Type II NAD(P)H:Quinone Oxidoreductases
Authors: Melo Ana M. P. , Bandeiras Tiago M. , Teixeira Miguel 
Published: December 2004

SUMMARY

Type II NAD(P)H:quinone oxidoreductases (NDH-2) catalyze the
two-electron transfer from NAD(P)H to quinones, without any
energy-transducing site. NDH-2 accomplish the turnover of NAD(P)H,
regenerating the NAD(P)
+
pool, and may contribute to
the generation of a membrane potential through complexes III and IV.
These enzymes are usually constituted by a nontransmembrane polypeptide
chain of ∼50 kDa, containing a flavin moiety. There are a few
compounds that can prevent their activity, but so far no general
specific inhibitor has been assigned to these enzymes. However, they
have the common feature of being resistant to the complex I classical
inhibitors rotenone, capsaicin, and piericidin A. NDH-2 have particular
relevance in yeasts like
Saccharomyces cerevisiae
and in
several prokaryotes, whose respiratory chains are devoid of complex I,
in which NDH-2 keep the
[NADH]/[NAD
+
] balance and are
the main entry point of electrons into the respiratory chains. Our
knowledge of these proteins has expanded in the past decade, as a
result of contributions at the biochemical level and the sequencing of
the genomes from several organisms. The latter showed that most
organisms contain genes that potentially encode NDH-2. An overview of
this development is presented, with special emphasis on microbial
enzymes and on the identification of three subfamilies of
NDH-2.
Streamlined Regulation and Gene Loss as Adaptive Mechanisms in
Prochlorococcus
for Optimized Nitrogen Utilization in Oligotrophic Environments
Authors: García-Fernández Jose Manuel , de Marsac Nicole Tandeau , Diez Jesús 
Published: December 2004

SUMMARY

Prochlorococcus
is one of the dominant cyanobacteria and a key primary producer in oligotrophic intertropical oceans. Here we present an overview of the pathways of nitrogen assimilation in
Prochlorococcus
, which have been significantly modified in these microorganisms for adaptation to the natural limitations of their habitats, leading to the appearance of different ecotypes lacking key enzymes, such as nitrate reductase, nitrite reductase, or urease, and to the simplification of the metabolic regulation systems. The only nitrogen source utilizable by all studied isolates is ammonia, which is incorporated into glutamate by glutamine synthetase. However, this enzyme shows unusual regulatory features, although its structural and kinetic features are unchanged. Similarly, urease activities remain fairly constant under different conditions. The signal transduction protein P
II
is apparently not phosphorylated in
Prochlorococcus
, despite its conserved amino acid sequence. The genes
amt1
and
ntcA
(coding for an ammonium transporter and a global nitrogen regulator, respectively) show noncorrelated expression in
Prochlorococcus
under nitrogen stress; furthermore, high rates of organic nitrogen uptake have been observed. All of these unusual features could provide a physiological basis for the predominance of
Prochlorococcus
over
Synechococcus
in oligotrophic oceans.
Type V Protein Secretion Pathway: the Autotransporter Story
Authors: Henderson Ian R. , Navarro-Garcia Fernando , Desvaux Mickaël , Fernandez Rachel C. , Ala'Aldeen Dlawer 
Published: December 2004

SUMMARYGram-negative bacteria possess an outer membrane layer which constrains uptake and secretion of solutes and polypeptides. To overcome this barrier, bacteria have developed several systems for protein secretion. The type V secretion pathway encompasses the autotransporter proteins, the two-partner secretion system, and the recently described type Vc or AT-2 family of proteins. Since its discovery in the late 1980s, this family of secreted proteins has expanded continuously, due largely to the advent of the genomic age, to become the largest group of secreted proteins in gram-negative bacteria. Several of these proteins play essential roles in the pathogenesis of bacterial infections and have been characterized in detail, demonstrating a diverse array of function including the ability to condense host cell actin and to modulate apoptosis. However, most of the autotransporter proteins remain to be characterized. In light of new discoveries and controversies in this research field, this review considers the autotransporter secretion process in the context of the more general field of bacterial protein translocation and exoprotein function.
INCUMBENCY AND THE DISRUPTIVE REGULATOR: THE CASE OF ELECTRIC VEHICLES IN CALIFORNIA
Authors: PILKINGTON ALAN , DYERSON ROMANO 
Published: December 2004

For much of the past century, the automobile sector has been dominated by a handful of oligopolistic firms, protected through path dependencies and the build up of complementary assets. But that very dominance built upon years of experience and translated into the periodic release of incrementally innovative new car designs, may now be threatened by the actions of regulators in California and elsewhere, in mandating emission friendly cars. The biggest challenge in this area has been the demand for zero emission vehicles resulting from Californian regulations. Zero emission legislation mandates the use of technologies radically different from those used in the development of internal combustion engines. Such technology acts in a disruptive manner on the existing skills base of the automobile firms, negating some of the benefits of incumbency. With little or no experience of the systems needed to develop a viable electric vehicle — batteries, electric motors and controllers — the established automobile manufacturers have struggled with a strategic question: how to incorporate disruptive elements into a mature organisation. This paper explores the nature of the regulatory threat and the strategic responses generated by the automobile firms.
Generation of a polyclonal rabbit anti-mouse tissue factor antibody by nucleic acid immunisation
Authors: Mumford Andrew , Chen Daxin , Dorling Anthony , Kemball-Cook Geoffrey , McVey John 
Published: December 2004

SummaryTissue factor (TF) the cellular receptor and cofactor for factor VII, initiates coagulation and has also been implicated in several coagulation-independent functions, including inflammation, angiogenesis and tumour metastasis. Investigations of TF expression in mouse models of these processes has been limited by the availability of antibodies that specifically recognise mouse TF.We have generated a rabbit polyclonal antibody to mTF by DNA immunisation. This has yielded an antiserum that recognises native mTF in immunohistochemical and flow cytometric analyses.Furthermore,the antiserum is inhibitory in coagulation assays.This antiserum will be a valuable investigative tool in the analysis of mTF expression.
Plasma glycocalicin as a source of GPIbα in the von Willebrand factor ristocetin cofactor ELISA
Authors: Pareyn Inge , Schlammadinger Agota , Vauteri Stephan , Hoylaerts Marc , Arnout Jef , Deckmyn Hans , Vanhoorelbeke Karen 
Published: December 2004

SummaryWe have previously demonstrated that the von Willebrand factor ristocetin cofactor activity (VWF:RCo),used in the diagnosis of vonWillebrand disease (VWD),can be accurately determined via ELISA by measuring the ristocetin-induced binding ofVWF to a captured recombinant fragment of GPIb α (rfGPIb α ,AA 1–289) (Vanhoorelbeke et al., Thromb Haemost 2000; 83: 107-13). This ELISA is more reliable than the currently used platelet agglutination test. Normal plasma contains relatively high concentrations of glycocalicin, a proteolytic fragment of GPIb α . We therefore studied whether non-purified plasma glycocalicin can replace rfGPIbα in our ELISA. Of 42 anti-GPIbα monoclonal antibodies (MAbs) capable of binding plasma glycocalicin, only one MAb captured glycocalicin in a spatial orientation exposing theVWF-binding site in glycocalicin,allowing a specific and dosedependent ristocetin-mediated VWF-binding. Intra- and interassay variability were comparable with those for the rfGPIbα basedVWF:RCo ELISA.TheVWF:RCo activity of plasma from 33 normal individuals, 19 type 1, 16 type 2A, 9 type 2B, 8 type 2M and 7 type 3VWD patients was determined with this ELISA and allowed a clear identification ofVWD patients.Furthermore,determination of the VWF:RCo/VWF:Ag ratio resulted in the discrimination between type 1 and type 2 VWD patients. Results for the glycocalicin based and the rfGPIb α basedVWF:RCo ELISAs were in good agreement (r = 0.943).There was also a good correlation between the glycocalicin based ELISA and the standard platelet agglutination test (r = 0.963).In conclusion,to diagnose VWD, a VWF:RCo ELISA based on antibody immobilized plasma glycocalicin can be performed reliably.
Herbal remedies and anticoagulant therapy
Authors: Samuels Noah 
Published: December 2004

SummaryHerbal remedies, considered to be both safe and effective by most consumers, may interact with conventional drugs.Warfarin, a vitamin K antagonist originally derived from the sweet clover plant, has a narrow therapeutic window which can be monitored using prothrombin international normalized ratios (PT-INR). Many herbs can increase the risk for bleeding when combined with warfarin, either by augmenting the anticoagulant effects of the drug (with increased PT-INR levels) or through intrinsic anti-platelet properties (without altering PT-INR levels). The increased risk for bleeding among such patients may be difficult to predict, especially when formulas which contain many herbs are used. Further research into herb-drug interactions is warranted, as are guidelines for the use of herbal remedies by patients on chronic anticoagulation therapy.
The plasminogen activator inhibitor (PAI-1) 4G/5G promoter polymorphism and PAI-1 levels in ischemic stroke
Authors: García Encarna , Leebeek Frank , Brouwers Geert-Jan , Koudstaal Peter , Dippel Diederik , Goor Mary-Lou 
Published: December 2004

SummaryHigh levels of plasminogen activator inhibitor type 1 (PAI-1) have been implicated as a risk factor for cardiovascular disease, but its precise role remains controversial.The 4G allele of the PAI-1 4G/5G promoter polymorphism is associated with higher levels of PAI-1. We studied the relationship between ischemic stroke and the PAI-1 4G/5G polymorphism and PAI-1 antigen levels. We performed a case-control study among patients aged 18–75 years with first ischemic stroke, confirmed by CT.All patients were screened for cardiovascular risk factors, cardiac disorders and large vessel disease. We excluded patients with a definite non-atherosclerotic cause of the stroke and patients using oral anticoagulants. Population-controls were age -and sex-matched, without a history of stroke, and of the Caucasian race.Venous blood samples were taken for PAI-1 4G/5G polymorphism and PAI-1 level one week after stroke.We included 124 patients and 125 controls. Mean age was 56 yrs (range 18 to 75 yrs). Sixty one patients (50%) and 58 (47%) controls were heterozygous for the PAI-1 4G/5G polymorphism.The homozygous 4G/4G genotype was found in 33 patients (27%) and in 36 controls (29%). The odds ratio of ischemic stroke associated with 4G-carriers versus 5G/5G homozygotes was 1.0 (95% CI: 0.6–1.8).The relative risk of ischemic stroke associated with the level of PAI-1 in the upper quartile was 0.73 (95%CI: 0.4 to 1.4). Neither the PAI-1 4G/5G polymorphism nor the PAI-1 antigen level is a strong risk factor for ischemic stroke.
Blood and bone: two tissues whose fates are intertwined to create the hematopoietic stem-cell niche
Authors: Taichman Russell S. 
Published: December 2004

AbstractThe mechanisms of bone and blood formation have traditionally been viewed as distinct, unrelated processes, but compelling evidence suggests that they are intertwined. Based on observations that hematopoietic precursors reside close to endosteal surfaces, it was hypothesized that osteoblasts play a central role in hematopoiesis, and it has been shown that osteoblasts produce many factors essential for the survival, renewal, and maturation of hematopoietic stem cells (HSCs). Preceding these observations are studies demonstrating that the disruption or perturbation of normal osteoblastic function has a profound and central role in defining the operational structure of the HSC niche. These observations provide a glimpse of the dimensions and ramifications of HSC-osteoblast interactions. Although more research is required to secure a broader grasp of the molecular mechanisms that govern blood and bone biology, the central role for osteoblasts in hematopoietic stem cell regulation is reviewed herein from the perspectives of (1) historical context; (2) the role of the osteoblast in supporting stem cell survival, proliferation, and maintenance; (3) the participation, if any, of osteoblasts in the creation of a stem cell niche; (4) the molecules that mediate HSC-osteoblast interactions; (5) the role of osteoblasts in stem cell transplantation; and (6) possible future directions for investigation.
Vessel wall–derived endothelial cells rapidly proliferate because they contain a complete hierarchy of endothelial progenitor cells
Authors: Ingram David A. , Mead Laura E. , Moore Daniel B. , Woodard Wayne , Fenoglio Amy , Yoder Mervin C. 
Published: December 2004

AbstractEndothelial progenitor cells (EPCs) can be isolated from adult peripheral and umbilical cord blood and expanded exponentially ex vivo. In contrast, human umbilical vein endothelial cells (HUVECs) or human aortic endothelial cells (HAECs) derived from vessel walls are widely considered to be differentiated, mature endothelial cells (ECs). However, similar to adult- and cord blood–derived EPCs, HUVECs and HAECs derived from vessel walls can be passaged for at least 40 population doublings in vitro. Based on this paradox, we tested whether EPCs reside in HUVECs or HAECs utilizing a novel single cell deposition assay that discriminates EPCs based on their proliferative and clonogenic potential. We demonstrate that a complete hierarchy of EPCs can be identified in HUVECs and HAECs derived from vessel walls and discriminated by their clonogenic and proliferative potential. This study provides evidence that a diversity of EPCs exists in human vessels and provides a conceptual framework for determining both the origin and function of EPCs in maintaining vessel integrity.
Applied Research in Accounting: A Commentary*
Authors: RICHARDSON ALAN J. 
Published: December 2004

ABSTRACTThe mission of Canadian Accounting Perspectives is to provide a forum for “applied research” in accounting, but this key term is not defined. I identify three forms of applied research: (1) the use of existing knowledge to find solutions to current problems; (2) the use of positivist research methods to conduct critical tests between current alternative accounting methods and to identify empirical regularities that contribute to the development of technologies of practice; and (3) the use of disciplined inquiry and action research to develop mid‐range theory and generate empirical results that advance the interests or increase the capabilities of an identified community. This third form of applied research may provide the best approach to bridging the schism between academe and practice.
CAP Forum on E‐Business: The Management of Financial Disclosure on Corporate Websites: A Conceptual Model*
Authors: TRABELSI SAMIR , LABELLE RÉAL , LAURIN CLAUDE 
Published: December 2004

ABSTRACTThis paper addresses the impact of Internet financial reporting (IFR) on financial accounting theory by incorporating it into the general Gibbins, Richardson, and Waterhouse (GRW) (1990) disclosure‐management framework. The GRW model assumes that the firm has a relatively stable process of disclosure management. This process varies between two positions: one ritualistic and the other opportunistic. These dimensions can coexist in the same firm but, on average, the policy of a firm will be either more ritualistic or more opportunistic. Our survey of the financial information disclosed in traditional financial reporting (TFR) as compared with the website disclosures of a random sample of Canadian companies documents a significant difference between TFR and IFR, as well as a wide variability among the sample firms in their use of IFR content, format, and technology. We interpret this variability in the incremental difference of IFR over TFR as an indication that a firm's ritualistic or opportunistic behaviour under IFR is not different from its behaviour under TFR. Thus, the adapted GRW (1990) conceptual model appears to have the potential to support future research in the management of financial disclosure on corporate websites.
CAP Forum on E‐Business: E‐Commerce and Tax Planning: Canadian Experiences*
Authors: CARNAGHAN CARLA , DOWNER PAULINE , KLASSEN KEN , PITTMAN JEFFREY 
Published: December 2004

ABSTRACTThis paper explores the deployment of e‐commerce by Canadian firms in the global marketplace, with an emphasis on the implications of e‐commerce for tax planning. The business press and various government task forces have discussed challenges raised by e‐commerce for traditional “source‐based” tax systems; however, these discussions have presented little evidence of firms' reliance on e‐commerce for tax‐planning purposes. Similarly, academic research has seldom examined whether firms' decisions to implement e‐commerce are by tax‐planning considerations.It is thus largely unknown whether firms actively consider taxation issues when evaluating e‐commerce, how the factors that have been identified as influencing decisions to implement e‐commerce systems are balanced against tax‐planning considerations, and what barriers might exist in practice to using e‐commerce for tax planning. We choose a qualitative interview‐based approach to explore these issues.Our findings suggest that tax planning is not considered by most of our respondent companies in their decisions to deploy e‐commerce. The companies we interviewed tended to implement e‐commerce over several years, starting with back‐office technologies like enterprise resource planning (ERP) systems. Accordingly, the ability to perform online sales transactions, which is a key component of using e‐commerce for tax planning, often was not yet in place. One implication of these results is that if concerns over tax revenue losses are realistic, tax policymakers may have some time to refine tax legislation to address the challenges raised by e‐commerce.
CAP Forum on E‐Business: Compromise or Customize: XBRL's Paradoxical Power
Authors: COHEN ERIC E. 
Published: December 2004

ABSTRACTBusiness reports are changing in response to regulatory and market demands. Requests by regulators for electronic filings of financial statements and tax forms are increasing and such filings are rapidly becoming mandatory in many countries. In response, extensible business reporting language (XBRL) is a market‐driven, collaborative effort to make electronic filings more useful to, and to reduce the burden on, both publishers and consumers of business reports.XBRL does much more than simply list data items that can be submitted in an electronic filing. XBRL is a complete set of tools for regulators or groups to fully communicate the meanings of and interrelationships among the business reporting concepts. In addition, core sets of concepts from regulators or groups can be extended, expanded, or otherwise modified for more specific communication by jurisdictions, industries, or individual corporations.This unique customization capability lets companies better present their electronic filings as parallels to their paper filings. A “customizable standard” offers new opportunities and new challenges. This paper discusses XBRL's paradoxical power ‐ the trade‐offs between customizing to better parallel existing paper reports and compromising to more closely match the standards, and the research needed for the transition from freeform to customized reports.
Facile Syntheses of Aminocyclopropanes:

N

,

N

‐Dibenzyl‐

N

‐(2‐Ethenylcyclopropyl)Amine
Authors: de Meijere Armin , Winsel Harald , Stecker Björn 
Published: December 2004

Abstract

N,N‐
Dibenzyl‐
N‐
(2‐ethylenylcyclopropyl)amine

N,N‐
Dimethylformamide

Methyl tris(isopropoxy)titanium

Titanium tetraisopropoxide

Titanium tetrachloride

Methyllithium
dl

‐Selective Pinacol‐Type Coupling Using Zinc, Chlorosilane, and Catalytic Amounts of
Cp
2
VCl
2
;

dl

‐1,2‐dicyclohexylethanediol
Authors: Hirao Toshikazu , Ogawa Akiya , Asahara Motoki , Muguruma Yasuaki , Sakurai Hidehiro 
Published: December 2004

Abstract

Dichlorodicyclopentadienylvanadium

Chlorotrimethylsilane

Cyclohexanecarboxaldehyde

1,2‐Cyclohexylethanediol
Synthesis of
N
‐(

tert

‐Butoxycarbonyl)‐β‐Iodoalanine Methyl Ester: A Useful Building Block in the Synthesis of Nonnatural α‐Amino Acids via Palladium Catalyzed Cross Coupling Reactions
Authors: Jackson Richard F. W. , Perez‐Gonzalez Manuel 
Published: December 2004

Abstract

N‐(tert‐
Butoxycarbonyl)‐L‐serine methyl ester

N‐(tert‐
Butoxycarbonyl)‐beta‐iodoalanine methyl ester

N
‐(
tert‐
Butoxycarbonyl)‐beta‐4‐(methoxycarbonyl)phenylalanine methyl ester

4‐Diaminopyridine

Tris(dibenzylideneacetone)dipalladium
Synthesis of 3‐Pyridylboronic Acid and its Pinacol Ester. Application of 3‐Pyridylboronic Acid in
S
uzuki Coupling to Prepare 3‐Pyridin‐3‐ylquinoline
Authors: Li Wenjie , Nelson Dorian P. , Jensen Mark S. , Hoerrner R. Scott , Cai Dongwei , Larsen Robert D. 
Published: December 2004

Abstract

3‐Pyridylboronic acid

Tris(3‐pryidyl)boroxin

3‐(4,4,5,5‐Tetramethyl‐[1,3,2]dioxaborlan‐2‐yl)‐pyridine

3‐Pyridin‐3‐ylquinoline

Pinacol
Synthesis of 5‐Bromoisoquinoline and 5‐Bromo‐8‐nitroisoquinoline
Authors: Dalby Brown William , Haahr Gouliaev Alex 
Published: December 2004

Abstract

Isoquinoline

N‐
Bromosuccinimide

5‐Bromoisoquinoline

5‐Bromo‐8‐nitroisoquinoline
Practical Synthesis of Novel Chiral Allenamides: (
R
)‐4‐Phenyl‐3‐(1,2‐propadienyl)oxazolidin‐2‐one
Authors: Xiong H. , Tracey M. R. , Grebe T. , Mulder J. A. , Hsung R. P. 
Published: December 2004

Abstract

(R)‐4‐Phenyl‐2‐oxazolidinone

R‐
4‐Phenyl‐3‐(2‐propynyl)‐2‐oxazolidinone

R‐
Phenyl‐3‐(1, 2‐propadieny)2‐oxaloldinone

Potassium
tert‐
butoxide