bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the Robustness and Recovery of Critical Infrastructures by Goal Tree–Success Tree: Dynamic Master Logic Diagram, Within a Multistate System-of-Systems Framework, in the Presence of Epistemic Uncertainty
Authors: Ferrario E. , Pedroni N. , Zio E. 
Published: April 2015

In this paper, we evaluate the robustness and recovery of connected critical infrastructures (CIs) under a system-of-systems (SoS) framework taking into account: (1) the dependencies among the components of an individual CI and the interdependencies among different CIs; (2) the variability in component performance, by a multistate model; and (3) the epistemic uncertainty in the probabilities of transitions between different components states and in the mean values of the holding-times distributions, by means of intervals. We adopt the goal tree success tree–dynamic master logic diagram (GTST–DMLD) for system modeling and perform the quantitative assessment by Monte Carlo simulation. We illustrate the approach by way of a simplified case study consisting of two interdependent infrastructures (electric power system and gas network) and a supervisory control and data acquisition (SCADA) system connected to the gas network.
Interval Fractile Levels for Stationary Stochastic Response of Linear Structures With Uncertainties
Authors: Muscolino Giuseppe , Santoro Roberta , Sofi Alba 
Published: April 2015

Abstract
In the framework of stochastic analysis, the extreme response value of a structural system is completely described by its CDF. However, the CDF does not represent a direct design provision. A more meaningful parameter is the response level which has a specified probability, p, of not being exceeded during a specified time interval. This quantity, which is basically the inverse of the CDF, is referred to as a fractile of order p of the structural response. This study presents an analytical procedure for evaluating the lower bound and upper bound of the fractile of order p of the response of linear structures, with uncertain stiffness properties modeled as interval variables subjected to stationary stochastic excitations. The accuracy of the proposed approach is demonstrated by numerical results concerning a wind-excited truss structure with uncertain Young’s moduli.
Effect of Induced Vorticity in the Vaneless Diffuser on Performance of a Centrifugal Compressor
Authors: Ellis G. O. 
Published: April 2015

The following equation represents the vorticity induced in the flow of the diffuser by a gradient in total pressure parallel to the axis of the compressor:
Ω ¯ − Ω ¯ 2 = 2 V 2 g p ( dp t dz ) 2 ( r r 2 − 1 ) [ i ¯ tan α 2 r / r 2 ( r r 2 + 1 ) + j ¯ ]
The ith component is the component of vorticity which is tangent to the flow direction while the jth component is that which is normal to the flow direction. The velocity and vorticity vectors are shown schematically in Fig. 1.
Genetic Analyses of Penicillin Binding Protein Determinants in Multidrug-Resistant Streptococcus pneumoniae Serogroup 19 CC320/271 Clone with High-Level Resistance to Third-Generation Cephalosporins
Authors: Ip Margaret , Ang Irene , Liyanapathirana Veranja , Ma Helen , Lai Raymond 
Published: April 2015

ABSTRACT

We describe the dissemination of a multidrug-resistant (MDR) serogroup 19 pneumococcal clone of representative multilocus sequence type 271 (ST271) with high-level resistance to cefotaxime in Hong Kong and penicillin binding protein (
pbp
) genes and its relationships to Taiwan
19F
-14 and the prevalent multidrug-resistant 19A clone (MDR19A-ST320). A total of 472 nonduplicate isolates from 2006 and 2011 were analyzed. Significant increases in the rates of nonsusceptibility to penicillin (PEN) (MIC ≥ 4.0 μg/ml; 9.9 versus 23.3%;
P
= 0.0005), cefotaxime (CTX) (MIC ≥ 2.0 μg/ml; 12.2 versus 30.3%;
P
< 0.0001 [meningitis MIC ≥ 1.0 μg/ml; 30.2 versus 48.7%;
P
= 0.0001]), and erythromycin (ERY) (69.2 versus 84.0%;
P
= 0.0003) were noted when rates from 2006 and 2011 were compared. The CTX-resistant isolates with MICs of 8 μg/ml in 2011 were of serotype 19F, belonging to ST271. Analyses of the penicillin binding protein 2x (PBP2x) amino acid sequences in relation to the corresponding sequences of the R6 strain revealed M339F, E378A, M400T, and Y595F substitutions found within the ST271 clone but not present in Taiwan
19F
-14 or MDR19A. In addition, PBP2bs of ST271 strains and that of the Taiwan
19F
-14 clone were characterized by a unique amino acid substitution, E369D, while ST320 possessed the unique amino acid substitution K366N, as does that of MDR19A in the United States. We hypothesize that ST271 originated from the Taiwan
19F
-14 lineage, which had disseminated in Hong Kong in the early 2000s, and conferred higher-level β-lactam and cefotaxime resistance through acquisitions of 19 additional amino acid substitutions in PBP2b (amino acid [aa] positions 538 to 641) and altered PBP2x via recombination events. The serogroup 19 MDR CC320/271 clone warrants close monitoring to evaluate its effect after the switch to expanded conjugate vaccines.
Stability of the Antimalarial Drug Dihydroartemisinin under Physiologically Relevant Conditions: Implications for Clinical Treatment and Pharmacokinetic and
In Vitro
Assays
Authors: Parapini Silvia , Olliaro Piero , Navaratnam Visweswaran , Taramelli Donatella , Basilico Nicoletta 
Published: April 2015

ABSTRACT

Artemisinins are peroxidic antimalarial drugs known to be very potent but highly chemically unstable; they degrade in the presence of ferrous iron, Fe(II)-heme, or biological reductants. Less documented is how this translates into chemical stability and antimalarial activity across a range of conditions applying to
in vitro
testing and clinical situations. Dihydroartemisinin (DHA) is studied here because it is an antimalarial drug on its own and the main metabolite of other artemisinins. The behaviors of DHA in phosphate-buffered saline, plasma, or erythrocyte lysate at different temperatures and pH ranges were examined. The antimalarial activity of the residual drug was evaluated using the chemosensitivity assay on
Plasmodium falciparum
, and the extent of decomposition of DHA was established through use of high-performance liquid chromatography with electrochemical detection analysis. The role of the Fe(II)-heme was investigated by blocking its reactivity using carbon monoxide (CO). A significant reduction in the antimalarial activity of DHA was seen after incubation in plasma and to a lesser extent in erythrocyte lysate. Activity was reduced by half after 3 h and almost completely abolished after 24 h. Serum-enriched media also affected DHA activity. Effects were temperature and pH dependent and paralleled the increased rate of decomposition of DHA from pH 7 upwards and in plasma. These results suggest that particular care should be taken in conducting and interpreting
in vitro
studies, prone as their results are to experimental and drug storage conditions. Disorders such as fever, hemolysis, or acidosis associated with malaria severity may contribute to artemisinin instability and reduce their clinical efficacy.
The SmeYZ Efflux Pump of Stenotrophomonas maltophilia Contributes to Drug Resistance, Virulence-Related Characteristics, and Virulence in Mice
Authors: Lin Yi-Tsung , Huang Yi-Wei , Chen Shiang-Jiuun , Chang Chia-Wei , Yang Tsuey-Ching 
Published: April 2015

ABSTRACT

The resistance-nodulation-division (RND)-type efflux pump is one of the causes of the multidrug resistance of
Stenotrophomonas maltophilia
. The roles of the RND-type efflux pump in physiological functions and virulence, in addition to antibiotic extrusion, have attracted much attention. In this study, the contributions of the constitutively expressed SmeYZ efflux pump to drug resistance, virulence-related characteristics, and virulence were evaluated.
S. maltophilia
KJ is a clinical isolate of multidrug resistance. The
smeYZ
isogenic deletion mutant, KJΔYZ, was constructed by a gene replacement strategy. The antimicrobial susceptibility, virulence-related physiological characteristics, susceptibility to human serum and neutrophils, and
in vivo
virulence between KJ and KJΔYZ were comparatively assessed. The SmeYZ efflux pump contributed resistance to aminoglycosides and trimethoprim-sulfamethoxazole. Inactivation of
smeYZ
resulted in attenuation of oxidative stress susceptibility, swimming, flagella formation, biofilm formation, and secreted protease activity. Furthermore, loss of SmeYZ increased susceptibility to human serum and neutrophils and decreased
in vivo
virulence in a murine model. These findings suggest the possibility of attenuation of the resistance and virulence of
S. maltophilia
with inhibitors of the SmeYZ efflux pump.
The Efflux Pump SmeDEF Contributes to Trimethoprim-Sulfamethoxazole Resistance in Stenotrophomonas maltophilia
Authors: Sánchez María Blanca , Martínez José Luis 
Published: April 2015

ABSTRACT

Trimethoprim-sulfamethoxazole (co-trimoxazole) is one of the antimicrobials of choice for the treatment of
Stenotrophomonas maltophilia
infections. The analysis of mutants either lacking or overexpressing the efflux pump SmeDEF shows that this efflux pump contributes to intrinsic and acquired co-trimoxazole resistance in
S. maltophilia
. Since SmeDEF can extrude a variety of antibiotics, selection with such antimicrobials, including quinolones, might also select for
S. maltophilia
co-trimoxazole resistance.
Meropenem and Chromacef Intermediates Observed in IMP-25 Metallo-β-Lactamase-Catalyzed Hydrolysis
Authors: Oelschlaeger Peter , Aitha Mahesh , Yang Hao , Kang Joon S. , Zhang Antonia L. , Liu Eleanor M. , Buynak John D. , Crowder Michael W. 
Published: April 2015

ABSTRACT
Metallo-β-lactamases inactivate most β-lactam antibacterials, and much attention has been paid to their catalytic mechanism. One issue of controversy has been whether β-lactam hydrolysis generally proceeds through an anionic intermediate bound to the active-site Zn(II) ions or not. The formation of an intermediate has not been shown conclusively in imipenemase (IMP) enzymes to date. Here, we provide evidence that intermediates are formed during the hydrolysis of meropenem and chromacef catalyzed by the variant IMP-25 and, to a lesser degree, IMP-1.
New
In Vitro
Model To Study the Effect of Human Simulated Antibiotic Concentrations on Bacterial Biofilms
Authors: Haagensen Janus A. J. , Verotta Davide , Huang Liusheng , Spormann Alfred , Yang Katherine 
Published: April 2015

ABSTRACT

A new
in vitro
pharmacokinetic/pharmacodynamic simulator for bacterial biofilms utilizing flow cell technology and confocal laser scanning microscopy is described. The device has the ability to simulate the changing antibiotic concentrations in humans associated with intravenous dosing on bacterial biofilms grown under continuous culture conditions. The free drug concentrations of a single 2-g meropenem intravenous bolus dose and first-order elimination utilizing a half-life of 0.895 h (elimination rate constant, 0.776 h
−1
) were simulated. The antibacterial activity of meropenem against biofilms of
Pseudomonas aeruginosa
PAO1 and three clinical strains isolated from patients with cystic fibrosis was investigated. Additionally, the effect of meropenem on PAO1 biofilms cultured for 24 h versus that on biofilms cultured for 72 h was examined. Using confocal laser scanning microscopy, rapid biofilm killing was observed in the first hour of the dosing interval for all biofilms. However, for PAO1 biofilms cultured for 72 h, only bacterial subpopulations at the periphery of the biofilm were affected, with subpopulations at the substratum remaining viable, even at the conclusion of the dosing interval. The described model is a novel method to investigate antimicrobial killing of bacterial biofilms using human simulated concentrations.
Dynamic Virus-Bacterium Interactions in a Porcine Precision-Cut Lung Slice Coinfection Model: Swine Influenza Virus Paves the Way for Streptococcus suis Infection in a Two-Step Process
Authors: Meng F. , Wu N. H. , Nerlich A. , Herrler G. , Valentin-Weigand P. , Seitz M. 
Published: April 2015

ABSTRACT

Swine influenza virus (SIV) and
Streptococcus suis
are common pathogens of the respiratory tract in pigs, with both being associated with pneumonia. The interactions of both pathogens and their contribution to copathogenesis are only poorly understood. In the present study, we established a porcine precision-cut lung slice (PCLS) coinfection model and analyzed the effects of a primary SIV infection on secondary infection by
S. suis
at different time points. We found that SIV promoted adherence, colonization, and invasion of
S. suis
in a two-step process. First, in the initial stages, these effects were dependent on bacterial encapsulation, as shown by selective adherence of encapsulated, but not unencapsulated,
S. suis
to SIV-infected cells. Second, at a later stage of infection, SIV promoted
S. suis
adherence and invasion of deeper tissues by damaging ciliated epithelial cells. This effect was seen with a highly virulent SIV subtype H3N2 strain but not with a low-virulence subtype H1N1 strain, and it was independent of the bacterial capsule, since an unencapsulated
S. suis
mutant behaved in a way similar to that of the encapsulated wild-type strain. In conclusion, the PCLS coinfection model established here revealed novel insights into the dynamic interactions between SIV and
S. suis
during infection of the respiratory tract. It showed that at least two different mechanisms contribute to the beneficial effects of SIV for
S. suis
, including capsule-mediated bacterial attachment to SIV-infected cells and capsule-independent effects involving virus-mediated damage of ciliated epithelial cells.
Role of Spermidine in Overwintering of Cyanobacteria
Authors: Zhu Xiangzhi , Li Qiong , Yin Chuntao , Fang Xiantao , Xu Xudong 
Published: April 2015

ABSTRACT

Polyamines are found in all groups of cyanobacteria, but their role in environmental adaptation has been barely investigated. In
Synechocystis
sp. strain PCC 6803, inactivation of spermidine synthesis genes significantly reduced the survivability under chill (5°C)-light stress, and the survivability could be restored by addition of spermidine. To analyze the effects of spermidine on gene expression at 5°C,
lacZ
was expressed from the promoter of carboxy(nor)spermidine decarboxylase gene (
CASDC
) in
Synechocystis
.
Synechocystis
6803::P

CASDC

-
lacZ
pretreated at 15°C showed a high level of LacZ activity for a long period of time at 5°C; without the pretreatment or with protein synthesis inhibited at 5°C, the enzyme activity gradually decreased. In a spermidine-minus mutant harboring P

CASDC

-
lacZ
,
lacZ
showed an expression pattern as if protein synthesis were inhibited at 5°C, even though the stability of its mRNA increased. Four other genes, including
rpoA
that encodes the α subunit of RNA polymerase, showed similar expression patterns. The chill-light stress led to a rapid increase of protein carbonylation in
Synechocystis
. The protein carbonylation then quickly returned to the background level in the wild type but continued to slowly increase in the spermidine-minus mutant. Our results indicate that spermidine promotes gene expression and replacement of damaged proteins in cyanobacteria under the chill-light stress in winter.

IMPORTANCE
Outbreak of cyanobacterial blooms in freshwater lakes is a worldwide environmental problem. In the annual cycle of bloom-forming cyanobacteria, overwintering is the least understood stage. Survival of
Synechocystis
sp. strain PCC 6803 under long-term chill (5°C)-light stress has been established as a model for molecular studies on overwintering of cyanobacteria. Here, we show that spermidine, the most common polyamine in cyanobacteria, promotes the survivability of
Synechocystis
under long-term chill-light stress and that the physiological function is based on its effects on gene expression and recovery from protein damage. This is the first report on the role of polyamines in survival of overwintering cyanobacteria. We also analyzed spermidine synthesis pathways in cyanobacteria on the basis of bioinformatic and experimental data.
Role and Function of LitR, an Adenosyl B
12
-Bound Light-Sensitive Regulator of Bacillus megaterium QM B1551, in Regulation of Carotenoid Production
Authors: Takano Hideaki , Mise Kou , Hagiwara Kenta , Hirata Naoya , Watanabe Shoko , Toriyabe Minami , Shiratori-Takano Hatsumi , Ueda Kenji 
Published: April 2015

ABSTRACT

The LitR/CarH family of proteins is a light-sensitive MerR family of transcriptional regulators that contain an adenosyl B
12
(coenzyme B
12
or AdoB
12
)-binding domain at the C terminus. The genes encoding these proteins are found in phylogenetically diverse bacterial genera; however, the biochemical properties of these proteins from Gram-positive bacteria remain poorly understood. We performed genetic and biochemical analyses of a homolog of the LitR protein from
Bacillus megaterium
QM B1551, a Gram-positive endospore-forming soil bacterium. Carotenoid production was induced by illumination in this bacterium.
In vivo
analysis demonstrated that LitR plays a central role in light-inducible carotenoid production and serves as a negative regulator of the light-inducible transcription of
crt
and
litR
itself. Biochemical evidence showed that LitR in complex with AdoB
12
binds to the promoter regions of
litR
and the
crt
operon in a light-sensitive manner.
In vitro
transcription experiments demonstrated that AdoB
12
-LitR inhibited the specific transcription of the
crt
promoter generated by a σ
A
-containing RNA polymerase holoenzyme under dark conditions. Collectively, these data indicate that the AdoB
12
-LitR complex serves as a photoreceptor with DNA-binding activity in
B. megaterium
QM B1551 and that its function as a transcriptional repressor is fundamental to the light-induced carotenoid production.

IMPORTANCE
Members of the LitR/CarH family are AdoB
12
-based photosensors involved in light-inducible carotenoid production in nonphototrophic Gram-negative bacteria. Our study revealed that
Bacillus
LitR in complex with AdoB
12
also serves as a transcriptional regulator with a photosensory function, which indicates that the LitR/CarH family is generally involved in the light-inducible carotenoid production of nonphototrophic bacteria.
Toward a Sparse Self-Organizing Map for Neuromorphic Architectures
Authors: Rodriguez Laurent , Miramond Benoît , Granado Bertrand 
Published: April 2015

Neurobiological systems have often been a source of inspiration for computational science and engineering, but in the past their impact has also been limited by the understanding of biological models. Today, new technologies lead to an equilibrium situation where powerful and complex computers bring new biological knowledge of the brain behavior. At this point, we possess sufficient understanding to both imagine new brain-inspired computing paradigms and to sustain a classical paradigm which reaches its end programming and intellectual limitations.
In this context, we propose to reconsider the computation problem first in the specific domain of mobile robotics. Our main proposal consists in considering computation as part of a global adaptive system, composed of sensors, actuators, a source of energy and a controlling unit. During the adaptation process, the proposed brain-inspired computing structure does not only execute the tasks of the application but also reacts to the external stimulation and acts on the emergent behavior of the system. This approach is inspired by cortical plasticity in mammalian brains and suggests developing the computation architecture along the system's experience.
This article proposes modeling this plasticity as a problem of estimating a probability density function. This function would correspond to the nature and the richness of the environment perceived through multiple modalities. We define and develop a novel neural model solving the problem in a distributed and sparse manner. And we integrate this neural map into a bio-inspired hardware substrate that brings the plasticity property into parallel many-core architectures. The approach is then called Hardware Plasticity. The results show that the self-organization properties of our model solve the problem of multimodal sensory data clusterization. The properties of the proposed model allow envisaging the deployment of this adaptation layer into hardware architectures embedded into the robot's body in order to build intelligent controllers.
O poder do corpo no espaço público: o urbano como privação e o direito à cidade
Authors: Carlos Ana Fani Alessandri 
Published: April 2015

<p><span style="font-family: Arial;"><span style="font-size: medium;"> </span><span style="font-size: medium;">Neste artigo parte da hipótese segundo a qual, a produção do espaço é um </span><span style="font-size: medium;"> </span><span style="font-size: medium;">elemento central para a compreensão do mundo moderno, tanto do ponto de vista da realização do processo acumulativo do capital, quanto da reprodução da vida social, na medida em que a produção do espaço é condição, meio e produto da reprodução social em sua totalidade.</span></span></p><p><span style="font-family: Arial;"><span style="font-size: medium;">As transformações da cidade são hoje marcadas pela contradição entre o que é necessário à realização da reprodução do capital e o que </span><span style="font-size: medium;"> </span><span style="font-size: medium;">necessecidade/desejo para a sociedade que faz dela o lugar dos conflitos posto que a</span><span style="font-size: medium;"> práxis urbana repõe, continuamente </span><span style="font-size: medium;">a desigualdade resultado do processo de valorização que cria a</span><span style="font-size: medium;"> cidade como segregação.</span></span></p><p><span style="font-family: Arial;"><span style="font-size: medium;">No Brasil de hoje, como em várias partes do mundo, vivemos o tempo das manifestações nas ruas e praças (como reafirmação do espaço público) tem-se </span><span style="font-size: medium;"> </span><span style="font-size: medium;">desdobrado em lutas pela cidade movidas pela necessidade de apropriação do espaço urbano para a realização de uma outra vida (que é, basicamente, urbana) aonde a privação vivida por uma parcela significativa da sociedade seja superada. As manifestações, serão entendidas como a forma que assumem os resíduos presentes no cotidiano contra o que se impõe como hegemônico. à realização da vida urbana.</span></span></p>
Caracterização do desempenho funcional de indivíduos com síndrome de Down
Authors: Souza Aline Bernardes de , Blascovi-Assis Silvana Maria , Rezende Luciana Krauss , Cymrot Raquel 
Published: April 2015

<p>Esta pesquisa procurou caracterizar o desempenho de crianças e jovens com síndrome de Down e a interação entre o perfil funcional e a assistência prestada pelo cuidador. Participaram desta pesquisa 44 cuidadores de crianças e jovens com síndrome de Down, com idades entre 7 anos e 6 meses de idade a 15 anos incompletos que foram avaliados através do Inventário PEDI. Estas<br />crianças e jovens com SD apresentaram um desempenho inferior em relação ao padrão normal além de menores escores na função social. Observou-se a influência da idade sobre algumas áreas funcionais e a linearidade entre a evolução da capacidade funcional e da ajuda do cuidador. Notou-se, também, que as crianças e jovens com síndrome de Down apresentam baixo desempenho funcional nesta faixa etária sob influência da idade.</p>