bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Coincident Index for the State of the Economy*
Authors: Nieto Fabio H. 
Published: August 2010

SummaryIn this paper, a methodology is developed for designing a coincident index for the so‐called state of the economy. Based on this index, statistical tests are deduced for checking structural changes in the economy and consistency of pre‐established economic goals for the short term with past and present observed information. The approach can also be considered as a new solution for the ex post (benchmarking, disaggregation) and ex ante (extrapolation) prediction problems.
On Testing for the Nullity of Some Skewness Coefficients
Authors: Ngatchou‐Wandji Joseph 
Published: August 2010

SummaryThree tests for the skewness of an unknown distribution are derived for iid data. They are based on suitable normalization of estimators of some usual skewness coefficients. Their asymptotic null distributions are derived. The tests are next shown to be consistent and their power under some sequences of local alternatives is investigated. Their finite sample properties are also studied through a simulation experiment, and compared to those of the √b2‐test.
Regression Analysis with a Stochastic Design Variable
Authors: Sazak Hakan S. , Tiku Moti L. , Islam M. Qamarul 
Published: August 2010

Summary In regression models, the design variable has primarily been treated as a nonstochastic variable. In numerous situations, however, the design variable is stochastic. The estimation and hypothesis testing problems in such situations are considered. Real life examples are given.
Estimating Urbanization Levels in Chinese Provinces in 1982—2000
Authors: Shen Jianfa 
Published: August 2010

SummaryNo consistent and reliable annual data series on the urbanization level for provincial regions of China is available. Making use of urban population data from the 1982 and 2000 population censuses, this paper estimates an annual data series of the urbanization level for provincial regions using an estimation approach developed on the basis of a conceptual model of dual‐track urbanization. Based on such estimated new urban data of provincial regions, the major trends of urbanization in Chinese provinces and the relationship between urbanization and economic development are analysed for the period 1982–2000.RésuméOn ne dispose pas de séries de données annuelles cohérentes et fiables sur le niveau d'urbanisation des régions de province chinoises. En utilisant les données de population urbaine des recensements de 1982 et 2000, cet article estime une série annuelle du niveau d'urbanisation des régions de province grâce à une approche développée sur la base d'un modèle conceptuel d'urbanisation différenciée. Sur la base de nouvelles données urbaines ainsi estimées pour les régions provinciales, on analyse les grandes tendances d'urbanisation dans les provinces chinoises et la relation entre l'urbanisation et le développement économique pour la période 1982–2000.
Measure for Measure: Exact F Tests and the Mixed Models Controversy
Authors: Lencina Viviana B. , Singer Julio M. 
Published: August 2010

SummaryWe consider exact F tests for the hypothesis of null random factor effect in the presence of interaction under the two factor mixed models involved in the mixed models controversy. We show that under the constrained parameter (CP) model, even in unbalanced data situations, MSB/MSE (in the usual ANOVA notation) follows an exact F distribution when the null hypothesis holds. We also obtain an exact F test for what is generally (and erroneously) assumed to be an equivalent hypothesis under the unconstrained parameter (UP) model. For unbalanced data, such a corresponding test statistic does not coincide with MSB/MSAB (the test statistic advocated for balanced data cases). We compute the power of the exact test under different imbalance patterns and show that although the loss of power increases with the degree of imbalance, it still remains reasonable from a practical point of view.
On the Utility of E‐Learning in Statistics
Authors: Härdle Wolfgang , Klinke Sigbert , Ziegenhagen Uwe 
Published: August 2010

Summary Students of introductory courses consider statistics as particularly difficult, as the understanding of the underlying concepts may require more time and energy than for other disciplines. For decades statisticians have tried to enhance understanding with the help of technical solutions such as animation, video or interactive tools. However, it is not clear if the added value generated by these e‐learning tools justifies the work invested. In this paper the experience with various e‐learning solutions in terms of utility and the impact on teaching is discussed.
Statistical Thinking in Computer‐Based Learning Environments
Authors: Schuyten Gilberte , Thas Olivier 
Published: August 2010

Summary The theme of technology is particularly important for statistics education because of the role of technology in changing views of statistical knowledge, pedagogy and learning. The interactive multimedia technology of today allows for the creation of powerful learning environments where the focus is on the process that produced the data and its associated variation and the statistical thinking required to solve the problem. However, despite this optimistic view, students' self‐regulation and intrinsic motivation seem to be key concepts for learning in complex interactive computer‐based learning environments. We conclude with observations of teachers and students working with applets. More of these evaluations should be published and/or made available to the statistical community so that both positive and negative teaching experiences can be shared.
Foundational Value of Statistics Education for Management Curriculum
Authors: Tamura Hirokuni 
Published: August 2010

Summary The purpose of this paper is to propose a unique and distinct value of statistics education for management. The 1986 inaugural conference on Making Statistics More Effective in Schools of Business (MSMESB) proposed valuable guidelines for reforming statistics education in schools of business. However, a survey conducted by McAlevey & Everett (2001) identified that their impact has been minimal, and argued that structural problems many business schools have are the potential cause. We argue these structural problems exist because the value of the body of statistical tools for management is ambiguous and has not been made explicit. The unique and distinct value of statistics for management can be identified as the body of tools necessary to meet the inherent needs of a manager charged with making predictive judgments facing data. The need arises because human information‐processing capacity is quite limited, as the findings of researchers in cognitive psychology testify. These findings also affirm that the basic statistical concepts needed for processing data cannot be learned from management experiences. The model of a manager faced with data, while considering the evidence of inherent limitations of human information‐processing capacity, establishes the foundational value of statistics training in the management curriculum. Statistics education in business schools will be made more effective when management educators recognize such value of the discipline, lend their support and reward the ownership commitment for continuous improvement and innovations of the business statistics curriculum.
One Possible Frame for Thinking about Experiential Learning
Authors: Cobb George W. 
Published: August 2010

SummaryI argue that teaching statistical thinking is harder than teaching mathematics, that experimental design is particularly well suited to teaching statistical thinking and that in teaching statistics, variation is good. We need a mix of archival data, simulations and activities, of varying degrees of complexity. Within this context, I applaud the important contributions to our profession represented byDariuset al. (2007), andNolan & Temple Lang (2007), the first for showing us how to make simulation‐based learning simultaneously more flexible and more realistic than ever before, and the second for showing us a path‐breaking technology that can make archival data the basis for active learning at an impressively high level of sophistication, embedding statistical thinking within real scientific and practical investigations.
Computer‐Aided Statistical Instruction—Multi‐Mediocre Techno‐Trash?
Authors: Schwarz Carl J. 
Published: August 2010

Summary The very soul of statistics are data, but few students actually collect data as part of their statistical journey. The impediments to real data collection exercises are very real—they are logistically difficult to set up, expensive, and may not work because of extraneous events outside the control of the instructor. Computer‐aided laboratories are a way to bring many of the benefits of actual data collection to students at a fraction of the cost and can be easily controlled by the instructor. There are many computer‐aided modules available—indeed a search on Google gave over 1 million hits. Some modules are good but many are mediocre. What separates the gems from the trash?
Extraction, purification and identification of bacterial signal molecules based on N‐acyl homoserine lactones
Authors: Wang Jianhua , Quan Chunshan , Wang Xue , Zhao Pengchao , Fan Shengdi 
Published: August 2010

SummaryBacteria possess an extraordinary repertoire for intercellular communication and social behaviour. This repertoire for bacterial communication, termed as quorum sensing (QS), depends on specific diffusible signal molecules. There are many different kinds of signal molecules in the bacterial community. Among those signal molecules, N‐acyl homoserine lactones (HSLs, in other publications also referred to as AHLs, acy‐HSLs etc.) are often employed as QS signal molecules for many Gram‐negative bacteria. Due to the specific structure and tiny amount of those HSL signal molecules, the characterization of HSLs has been the subject of extensive investigations in the last decades and has become a paradigm for bacteria intercellular signalling. In this article, different methods, including extraction, purification and characterization of HSLs, are reviewed. The review provides an insight into identification and characterization of new HSLs and other signal molecules for bacterial intercellular communication.
Refined class number formulas and Kolyvagin systems
Authors: Mazur Barry , Rubin Karl 
Published: August 2010

AbstractWe use the theory of Kolyvagin systems to prove (most of) a refined class number formula conjectured by Darmon. We show that, for every odd prime p, each side of Darmon’s conjectured formula (indexed by positive integers n) is ‘almost’ a p-adic Kolyvagin system as n varies. Using the fact that the space of Kolyvagin systems is free of rank one over ℤp, we show that Darmon’s formula for arbitrary n follows from the case n=1, which in turn follows from classical formulas.
ampG
Gene of
Pseudomonas aeruginosa
and Its Role in β-Lactamase Expression
Authors: Zhang Ying , Bao Qiyu , Gagnon Luc A. , Huletsky Ann , Oliver Antonio , Jin Shouguang , Langaee Taimour 
Published: August 2010

ABSTRACT

In enterobacteria, the
ampG
gene encodes a transmembrane protein (permease) that transports 1,6-GlcNAc-anhydro-MurNAc and the 1,6-GlcNAc-anhydro-MurNAc peptide from the periplasm to the cytoplasm, which serve as signal molecules for the induction of
ampC
β-lactamase. The role of AmpG as a transporter is also essential for cell wall recycling.
Pseudomonas aeruginosa
carries two AmpG homologues, AmpG (PA4393) and AmpGh1 (PA4218), with 45 and 41% amino acid sequence identity, respectively, to
Escherichia coli
AmpG, while the two homologues share only 19% amino acid identity. In
P. aeruginosa
strains PAO1 and PAK, inactivation of
ampG
drastically repressed the intrinsic β-lactam resistance while
ampGh1
deletion had little effect on the resistance. Further, deletion of
ampG
in an
ampD
-null mutant abolished the high-level β-lactam resistance that is associated with the loss of AmpD activity. The cloned
ampG
gene is able to complement both the
P. aeruginosa
and the
E. coli ampG
mutants, while that of
ampGh1
failed to do so, suggesting that PA4393 encodes the only functional AmpG protein in
P. aeruginosa
. We also demonstrate that the function of AmpG in laboratory strains of
P. aeruginosa
can effectively be inhibited by carbonyl cyanide
m
-chlorophenylhydrazone (CCCP), causing an increased sensitivity to β-lactams among laboratory as well as clinical isolates of
P. aeruginosa
. Our results suggest that inhibition of the AmpG activity is a potential strategy for enhancing the efficacy of β-lactams against
P. aeruginosa
, which carries inducible chromosomal
ampC
, especially in AmpC-hyperproducing clinical isolates.
bla
ROB-1
Presence on pB1000 in
Haemophilus influenzae
Is Widespread, and Variable Cefaclor Resistance Is Associated with Altered Penicillin-Binding Proteins
Authors: Tristram Stephen G. , Littlejohn Rachael , Bradbury Richard S. 
Published: August 2010

ABSTRACT

Plasmid pB1000 is a small replicon recently identified as bearing
bla
ROB-1
in animal and human
Pasteurellaceae
in Spain. We identified pB1000 in 11
bla
ROB-1
-positive Australian and North American
Haemophilus influenzae
isolates, suggesting a wider role for pB1000 in disseminating
bla
ROB-1
. Native
H. influenzae
conjugative elements can mobilize plasmids similar to pB1000 at a low frequency of 10
−8
, and this might account for the infrequency of
bla
ROB-1
compared to the rate of occurrence of
bla
TEM-1
. Altered penicillin-binding protein 3 was associated with an increased cefaclor MIC in 3 isolates.
Diversity of Staphylococcal Cassette Chromosome
mec
Elements in Predominant Methicillin-Resistant
Staphylococcus aureus
Clones in a Small Geographic Area
Authors: Basset Patrick , Senn Laurence , Vogel Valérie , Zanetti Giorgio , Blanc Dominique S. 
Published: August 2010

ABSTRACT

Recent population genetic studies suggest that staphylococcal cassette chromosome
mec
(SCC
mec
) was acquired much more frequently than previously thought. In the present study, we aimed to investigate the diversity of SCC
mec
elements in a local methicillin-resistant
Staphylococcus aureus
(MRSA) population. Each MRSA isolate (one per patient) recovered in the Vaud canton of Switzerland from January 2005 to December 2008 was analyzed by the double-locus sequence typing (DLST) method and SCC
mec
typing. DLST analysis indicated that 1,884/2,036 isolates (92.5%) belong to four predominant clones. As expected from the local spread of a clone, most isolates within clones harbored an identical SCC
mec
type. However, three to seven SCC
mec
types have been recovered in every predominant DLST clone, suggesting that some of these elements might have been acquired locally. This pattern could also be explained by distinct importations of related isolates into the study region. The addition of a third highly variable locus to further increase the discriminatory power of typing as well as epidemiological data suggested that most ambiguous situations were explained by the second hypothesis. In conclusion, our study showed that even if the acquisition of new SCC
mec
elements at a local level likely occurs, it does not explain all the diversity observed in the study region.
Demonstration of Conjugative Transposon (Tn
5397
)-Mediated Horizontal Gene Transfer between
Clostridium difficile
and
Enterococcus faecalis
Authors: Jasni Azmiza S. , Mullany Peter , Hussain Haitham , Roberts Adam P. 
Published: August 2010

ABSTRACT

Antibiotic-resistant
Enterococcus faecalis
and
Clostridium difficile
are responsible for nosocomial infections in humans, in which they inhabit the same niche. Here, we demonstrate transfer of the conjugative transposon Tn
5397
from
C. difficile
630 to
E. faecalis
JH2-2, the first reported gene transfer between these two bacteria. Furthermore, transfer from the
E. faecalis
EF20A transconjugant to the epidemic ribotype 027
C. difficile
strain R20291 was also demonstrated. Tn
5397
was shown to use a single specific target site in
E. faecalis
; it also has specific target sites in
C. difficile
. These experiments highlight the importance of continual monitoring for emerging resistances in these bacteria.
Efficacy of Calcium-EDTA as an Inhibitor for Metallo-β-Lactamase in a Mouse Model of
Pseudomonas aeruginosa
Pneumonia
Authors: Aoki Nobumasa , Ishii Yoshikazu , Tateda Kazuhiro , Saga Tomoo , Kimura Soichiro , Kikuchi Yoshiaki , Kobayashi Tetsuo , Tanabe Yoshinari , Tsukada Hiroki , Gejyo Fumitake , Yamaguchi Keizo 
Published: August 2010

ABSTRACT

In this study, we have evaluated the efficacy of calcium-EDTA (Ca-EDTA) as an inhibitor of bacterial metalloenzymes, such as metallo-β-lactamase (MBL) and other proteases, in a mouse model of
Pseudomonas aeruginosa
pneumonia. The simultaneous presence of Ca-EDTA (32 μg/ml) reduced the MICs of imipenem (IPM) in all MBL-producing
P. aeruginosa
isolates (IMP-1, -2, -7, and -10 and VIM-2) but not non-MBL-producing strains. In the pneumonia model, mice were intranasally infected with MBL-producing
P. aeruginosa
and then kept under conditions of hyperoxia to mimic ventilator-associated pneumonia. With both intranasal and subcutaneous administrations, Ca-EDTA significantly potentiated survival benefits of IPM compared to those of IPM alone. Ca-EDTA combination therapy induced a significant reduction of the bacterial burden in the lungs (
P
< 0.05). Furthermore, the inhibition activity of Ca-EDTA against MBL activity was confirmed by using the purified IMP-1 enzyme, which was characterized by a 50% inhibitory concentration (IC
50
) of 55 ± 8.2 μM. Finally, the protective effects of Ca-EDTA were demonstrated by culture supernatant-induced epithelial cell damage and acute lung injury in mice. These data suggest the therapeutic potential of Ca-EDTA not only by the blocking of MBLs but also by neutralizing tissue-damaging metalloproteases in
P. aeruginosa
infections.
A Novel Galacto-Glycerolipid from
Oxalis corniculata
Kills
Entamoeba histolytica
and
Giardia lamblia
Authors: Manna Dipak , Dutta Pradeep K. , Achari Basudeb , Lohia Anuradha 
Published: August 2010

ABSTRACT

Oxalis corniculata
is a naturally occurring weed that has been used in traditional medicine for the cure of dysentery and diarrhea in India. One of the common causes of dysentery is due to infection by the protist pathogen
Entamoeba histolytica.
Bioactivity profiling of extracts from
O. corniculata
identified several compounds that showed antiamoebic activity in axenic cultures of
E. histolytica
. These were characterized by nuclear magnetic resonance, infrared, and mass spectrometry as (i) Oc-1, a mixture of saturated fatty acids C
24
to C
28
; (ii) Oc-2, a mixture of long-chain alcohols C
18
to C
28
; and (iii) Oc-3, a single compound that was a galacto-glycerolipid (GGL). Of the different compounds that were obtained, the strongest antiamoebic activity was found in GGL. The addition of GGL to
E. histolytica
xenic cultures containing other microbial flora from the large intestine did not affect its antiamoebic activity. Amoebicidal concentrations of GGL had no effect on intestinal microbial flora or on the mammalian cell line HEK-293. GGL was also found to be equally effective in killing another protist pathogen,
Giardia lamblia
, that causes diarrhea in humans. The importance of this study is based on the identification of novel natural products and the possibility of developing these compounds as active agents to treat at least two pathogenic parasitic intestinal infections endemic to tropical regions.
Sulfated Derivatives of
Escherichia coli
K5 Capsular Polysaccharide Are Potent Inhibitors of Human Cytomegalovirus
Authors: Mercorelli Beatrice , Oreste Pasqua , Sinigalia Elisa , Muratore Giulia , Lembo David , Palù Giorgio , Loregian Arianna 
Published: August 2010

ABSTRACT

To date, there are few drugs licensed for the treatment of human cytomegalovirus (HCMV) infections, most of which target the viral DNA polymerase and suffer from many drawbacks. Thus, there is still a strong need for new anti-HCMV compounds with novel mechanisms of action. In this study, we investigated the anti-HCMV activity of chemically sulfated derivatives of
Escherichia coli
K5 capsular polysaccharide. These compounds are structurally related to cellular heparan sulfate and have been previously shown to be effective against some enveloped and nonenveloped viruses. We demonstrated that two derivatives, i.e., K5-N,OS(H) and K5-N,OS(L), are able to prevent cell infection by different strains of HCMV at concentrations in the nanomolar range while having no significant cytotoxicity. Studies performed to elucidate the mechanism of action of their anti-HCMV activity revealed that these compounds do not interact with either the host cell or the viral particle but need a virus-cell interaction to exert antiviral effects. Furthermore, these K5 derivatives were able to inhibit the attachment step of HCMV infection, as well as the viral cell-to-cell spread. Since the mode of inhibition of these compounds appears to differ from that of the available anti-HCMV drugs, sulfated K5 derivatives could represent the basis for the development of a novel class of potent anti-HCMV compounds. Interestingly, our studies highlight that small variations of the K5 derivatives structure can modulate the selectivity and potency of their activities against different viruses, including viruses belonging to the same family.
Emergence and Distribution of Plasmids Bearing the
bla
OXA-51
-Like Gene with an Upstream IS
Aba1
in Carbapenem-Resistant
Acinetobacter baumannii
Isolates in Taiwan
Authors: Chen Te-Li , Lee Yi-Tzu , Kuo Shu-Chen , Hsueh Po-Ren , Chang Feng-Yee , Siu Leung-Kei , Ko Wen-Chien , Fung Chang-Phone 
Published: August 2010

ABSTRACT

The
bla
OXA-51
-like gene with an upstream IS
Aba1
(IS
Aba1
-
bla
OXA-51
-like gene) was originally found on the chromosomes of carbapenem-resistant or -susceptible
Acinetobacter baumannii
isolates. However, a plasmid-borne IS
Aba1
-
bla
OXA-51
-like gene has recently been identified in
Acinetobacter
genomic species 13TU and several
A. baumannii
isolates in Taiwan, and all of the isolates are carbapenem resistant. This study aimed to characterize the plasmids bearing the IS
Aba1
-
bla
OXA-51
-like gene and their significance in
A. baumannii
. Among the 117 IS
Aba1
-
bla
OXA-51
-like-harboring isolates collected from 10 hospitals in Taiwan, 58 isolates (49.6%) from 24 clones had the genes located on plasmids that likely originated from a common progenitor. Among the 58 isolates, four had additional copy of the IS
Aba1
-
bla
OXA-51
-like gene on their chromosomes. Based on the analysis of these four isolates, the plasmid-located IS
Aba1
-
bla
OXA-51
-like gene appeared to be acquired via one-ended transposition (Tn
6080
). The isolates with a plasmid bearing the IS
Aba1
-
bla
OXA-51
-like gene had higher rates of resistance to imipenem (98% versus 46.6%;
P
< 0.001) and meropenem (98% versus 69%;
P
= 0.019) than those with the genes chromosomally encoded, which is most likely due to increased gene dosage provided by the higher copy number of associated plasmids. Transformation with a recombinant plasmid harboring only the IS
Aba1
-
bla
OXA-51
-like gene was enough to confer a high level of carbapenem resistance to
A. baumannii
, eliminating the possible contribution of other factors on the original plasmids. This study demonstrated that the carbapenem resistance-associated plasmids carrying the IS
Aba1
-
bla
OXA-51
-like gene are widespread in
A. baumannii
strains in Taiwan.