bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration of ASTER and landsat TM remote sensing data for chromite prospecting and lithological mapping in Neyriz ophiolite zone, south Iran
Authors: Eslami Alireza , Ghaderi Majid , Rajendran Sankaran , Pour Amin Beiranvand , Hashim Mazlan
Published: September 2015

Chromite deposits in Iran are located in the ophiolite complexes, which have mostly podiform types and irregular in their settings. Exploration for podiform chromite deposits associated with ophiolite complexes has been a challenge for the prospectors due to tectonic disturbance and their distribution patterns. Most of Iranian ophiolitic zones are located in mountainous and inaccessible regions. Remote sensing approach could be applicable tool for choromite prospecting in Iranian ophiolitic zones with intensely rugged topography, where systematic sampling and conventional geological mapping are limited. In this study, Landsat Thematic Mapper (TM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite data were used for chromite prospecting and lithological mapping in the Neyriz ophiolitic zone in the south of Iran. Image transformation techniques, namely decorrelation stretch, band ratio and principal component analysis (PCA) were applied to Landsat TM and ASTER data sets for lithological mapping at regional scale. The RGB decorrelated image of Landsat TM spectral bands 7, 5, and 4, and the principal components PC1, PC2 and PC3 image of ASTER SWIR spectral bands efficiently showed the occurrence of major lithological units in the study area at regional scale. The band ratios of 5/3, 5/1, 7/5 applied on ASTER VNIR‐SWIR bands were very useful for discriminating most of rock units in the study area and delineation of the transition zone and mantle harzburgite in the Neyriz ophiolitic complex. Spectral Angle Mapper (SAM) technique was implemented to ASTER VNIR‐SWIR spectral bands for detecting minerals of rock units and especially delineation of the transition zone and mantle harzburgite as potential zones with high chromite mineralization in the Neyriz ophiolitic complex. The integration of information extracted from the image processing algorithms used in this study mapped most of lithological units of the Neyriz ophiolitic complex and identified potential areas of high chromite mineralization (transition zone and mantle harzburgite) for chromite prospecting targets in the future. Furthermore, image processing results were verified by comprehensive fieldwork and laboratory analysis in the study area. Accordingly, result of this investigation indicate that the integration of information extracted from the image processing algorithms using Landsat TM and ASTER data sets could be broadly applicable tool for chromite prospecting and lithological mapping in mountainous and inaccessible regions such Iranian ophiolitic zones.
A Multistep Methodology for Building a Stochastic Model of Gold Grades in the Disseminated and Complex Deposit of Casas Novas in Alentejo, Southern Portugal
Authors: Vieira Matias Filipa , Almeida Jose Antonio , Chichorro Martim
Published: September 2015

This paper proposes a multistep approach for creating a 3D stochastic model of gold grades in a complex disseminated auriferous deposit located in the Alentejo region, southern Portugal. The approach involves the following steps: (i) the creation of a 3D low‐resolution vector object model of two geological domains that better discriminate gold grades; (ii) the definition of three intervals for gold grades (low, intermediate, and high values); (iii) the estimation of the probability of each grid block belonging to each interval constrained by the geological domains; (iv) the calculation of local conditional cumulative distribution functions (CCDFs) of gold grades, for each block, taking into account the geological domains and the borehole data; and finally (v) the simulation of images of gold grades. The results demonstrate the usefulness and accuracy of the proposed procedure, as they are in compliance with the conceptual model, the distribution laws are conditioned by the geological domains, and the transition of grades between domains is continuous.
Amber‐bearing Bed in a Shallow Marine Setting, an Example from the Lower Cretaceous Miyako Group, Northeastern Japan
Authors: Fujino Shigehiro
Published: September 2015

A previously unknown amber‐bearing bed in the Lower Cretaceous Miyako Group, northeastern Japan, was deposited within a sequence that contains abundant marine macrofossils and wave‐generated sedimentary structures that suggest deposition in an open shallow marine environment. How the amber was transported from its terrestrial origin to the marine environment is unclear, but sedimentary gravity flow is a strong candidate. Our observations suggest that the occurrence of amber clasts in sediments deposited in open and closed shallow marine environments is not uncommon. Thus, in addition to terrestrial sediments, sediments of marine origin have potential as targets for amber exploration.
Changing Childrearing Beliefs Among Indigenous Rural‐to‐Urban Migrants in El Alto, Bolivia
Authors: Daniel Caitlin
Published: September 2015

Sociologists have long noted that childrearing shapes young people's life chances. Worldwide, rural‐to‐urban migration is growing, yet we know little about whether or how migrants adopt new childrearing beliefs during this rapid social transformation. Using interviews with 63 parents and ethnographic observation at a public school, I examine how rural‐to‐urban migration affects the childrearing beliefs of indigenous peasants who move to the city of El Alto, Bolivia. Many migrants reject rural childrearing's reliance on corporal punishment and limited verbal communication, instead embracing more open communication, limited physical punishment, and parent–child trust. Urban organizations and social ties expose parents to a new childrearing model, and parents find this model credible when they observe that it buffers children from urban dangers that threaten young people's mobility chances. Adopting urban childrearing ultimately entails accepting an underlying model of children's agency, wherein children need internal motivation instead of external impulsion. This case shows that individuals’ childrearing beliefs are more malleable than previous sociological studies suggest. I close with policy implications for parental education and child well‐being initiatives.
Insulin‐like growth factor I in cats: validation of an enzyme‐linked immunosorbent assay and determination of biologic variation
Authors: Strage Emma M. , Theodorsson Elvar , Ström Holst Bodil , Lilliehöök Inger , Lewitt Moira S.
Published: September 2015

Background

Insulin‐like growth factor I (IGF‐I) measurements are used in veterinary medicine for diagnosing growth hormone disorders. IGF‐I assays are subject to interference by IGF‐binding proteins (IGFBP) which may not be efficiently removed by standard extraction methods. Adding excess IGF‐II during analysis may improve accuracy.

Objectives

The purpose of the study was to validate a commercial human IGF‐I ELISA which uses excess IGF‐II for feline samples and to evaluate biologic variation.

Methods

Precision was determined by calculating the coefficient of variation (CV). Accuracy was determined by recovery after removal of IGFBP, addition of IGF‐I, and linear dilution after the addition of IGFBP. Biologic variation was determined by repeated sampling in 7 cats.

Results

There was interference by IGFBP in the high measuring range, resulting in falsely low IGF‐I concentrations. This was overcome by the addition of high concentrations of IGF‐II. Untreated serum had a measured/expected ratio of 98–115% compared to serum where IGFBP had been removed. Recovery after the addition of IGF‐I was 83–112%. Inter‐ and intra‐assay CVs ranged from 2.4% to 5.0% which is within the minimum acceptance criteria based on biologic variation. The reference interval of IGF‐I was wide (90–1207 ng/mL) and there was a significant association between body weight and ln IGF‐I (P < .000001).

Conclusions

This human ELISA is suitable for feline samples, but interfering IGFBP can cause falsely low concentrations. It is recommended to dilute samples such that IGF‐I is < 28 ng/mL on the standard curve to grant for sufficient IGF‐II for binding of interferent IGFBP.
¿De dónde surge la autoridad de los profesores chilenos? Análisis desde las perspectivas de los estudiantes
Authors: Zamora-Poblete Guillermo , Meza-Pardo Marisa , Cox-Vial Pilar
Published: September 2015

Actualmente la autoridad del profesor ya no reposa exclusivamente en la institución escolar; también debe ser construida por el propio maestro y reconocida por sus estudiantes. En esta línea, el presente artículo de investigación aborda un estudio que tiene el objetivo de caracterizar a los profesores con mayor autoridad desde las perspectivas de los estudiantes de enseñanza secundaria de distintos grupos socioeconómicos. Se recoge información mediante un cuestionario aplicado a 936 jóvenes de la ciudad de Santiago de Chile. Los resultados indican que los profesores reconocidos por su autoridad son aquellos que enseñan un saber altamente valorado, son respetuosos y proactivos.
Militares colombianos en la Alemania nazi, 1934-1937
Authors: Bosemberg Luis Eduardo
Published: September 2015

El artículo tiene el objetivo de mostrar de una manera narrativa la visita de militares colombianos a la Alemania nazi. Se parte de la idea de que dicha presencia no solo hace parte de las relaciones entre los dos países sino, más aún, de la formación de redes en espacios interrelacionados. Dichos militares se insertaron en el mundo militar alemán y este logró infiltrarse en Colombia. Se pregunta qué querían las partes involucradas, quiénes participaron, qué actitudes tenían los colombianos hacia ese país, si eran nazis esos militares. Se concluye que se enviaron tres misiones, quienes no solo visitaban Alemania ya que también fueron a otros países; sus reportes están llenos de admiración por el país anfitrión y el viaje les despertaba la crítica ya que obviamente comparaban todo el tiempo con su país. Pero la transmisión de conocimiento no pudo tener mucho efecto. La influencia estadounidense crecía y poco
después estalló la Segunda Guerra Mundial.
Democracia, participación y espacio local en Chile
Authors: Pressacco Carlos Fabián , Rivera Sebastián
Published: September 2015

La desconfianza ciudadana con la política y elmalestar con la democracia ha llevado a los sistemas políticos a explorar nuevos mecanismose instancias de participación que aminoren el protagonismo de las elites tradicionales en el proceso de toma de decisiones. Como casi todos los países de América Latina, Chileha desarrollado un proceso de reformas políticas que han tenido, entre otros elementos, el reforzamiento de los poderes locales como uno de sus ejes centrales, a su vez, articulado con innovaciones en el ámbito de la participación ciudadana local.No obstante ello, se trata de reformas graduales que no han logrado modificar de manera significativa la relación entre el gobierno local y la ciudadanía.
El peso de los nuevos partidos en el sistema de partidos colombiano. 1986-2010
Authors: Losada Rodrigo , Liendo Nicolás
Published: September 2015

En este artículo se documenta cómo ha evolucionadodurante el periodo 1986-2010 la volatilidadelectoral colombiana, en las elecciones de Senado,con énfasis en el peso que ejercen sobre esavolatilidad tanto el surgimiento de los partidosnuevos (creados en el periodo mencionado),como el debilitamiento de los partidos tradicionales.Se ofrece una interpretación de los hallazgosa la luz de la literatura internacional sobre eltema. La fuente básica de datos electorales es laRegistraduría Nacional del Estado Civil.
Computational analysis of 1,3-propanediol operon transcriptional regulators: Insights into Clostridium sp. glycerol metabolism regulation
Authors: Barragan Carlos Eduardo , Gutiérrez-Escobar Andrés Julián , Montoya Castaño Dolly
Published: September 2015

We designed a strategy for the sequencing and bioinformatical characterization of the 1,3-propanediol operon regulator genes from the Colombian Clostridium sp. strain IBUN13A, which is taxonomically related to Clostridium butyricum;. Three genes are proposed to be involved in the operon’s transcriptional activity, the S and A genes through a two-component system and the third gene named Y, which encodes a putative transcriptional regulator similar to the domains of the S/A system. Phylogenetic analyses indicated that the predicted proteins had a modular structure consisting of domains homologous to different signal transduction systems, but had significant differences concerning their conserved residues, pointing to the possibility that they constitute ancestral domains. In accordance with the prediction of functions, we propose a mechanism of regulation of the proteins studied of the 1,3-propanediol operon of the native strain, as a response to the presence of glycerol in the medium, which provides valuable information on the overall regulation of the glycerol metabolism in Clostridium sp.
Preservation of Azotobacter chroococcum vegetative cells in dry polymers
Authors: Rojas-Tapias Daniel , Ortega Sierra Oriana , Rivera Botía Diego , Bonilla Ruth
Published: September 2015

We studied the preservation of Azotobacter chroococcum C26 using three dry polymers: carrageenin, sodium alginate, and HPMC, using a method of accelerated degradation. Bacterial viability, as response variable, was measured at three temperatures in four different times, which was followed by calculation of bacterial degradation rates. Results showed that temperature, time of storage, and protective agent influenced both viability and degradation rates (P;lt;0.05). We observed, using the Arrhenius thermodynamic model, that the use of polymers increased the activation energy of bacterial degradation compared to control. We obtained thermodynamic models for each polymer, based on the Arrhenius equation, which predicted the required time for thermal degradation of the cells at different temperatures. Analysis of the models showed that carrageenin was the best polymer to preserve A. chroococcum C26 since ~ 900 days are required at 4 ºC to reduce its viability in two log units. We conclude, therefore, that long-term preservation of A. chroococcum C26 using dry polymers is suitable under adequate preservation and storage conditions.
Synthesis and in vitro Evaluation of Antifungal Properties of Some 4-Aryl-3-Methyl-1,2,3,4-Tetrahydroquinolines Derivatives
Authors: Romero Bohórquez Arnold R. , Kouznetsov Vladimir V. , Zacchino Susana A.
Published: September 2015

Two series of 4-aryl-3-methyl-1,2,3,4-tetrahydroquinoline derivatives were efficiently synthesized according to a two-step synthesis and evaluated as potential antifungal agents. The key step was the formation of the corresponding -benzyltetrahydroquinolines 5 via a three-component cationic imino Diels-Alder cycloaddition. The second step was a catalytic debenzylation to obtain the -unprotected tetrahydroquinolines 6. The products were isolated and purified by column chromatography. Substances were characterized using nuclear magnetic resonance (NMR) mass spectrometry (MS) and infrared spectroscopy (IR). All compounds were tested in vitro against standardized, clinically important fungi, including yeasts, hialohyphomycetes, and dermatophytes. These studies showed that between the tetrahydroquinoline series tested, compounds 6f and 6g showed antifungal activity, specifically against dermatophytes. The compound 6-methoxy-4-(4-hydroxi-3-methoxyphenyl)-3-methyl-1,2,3,4-tetrahydroquinoline 6g exhibited the best in vitroactivity (MIC 32-65 μg/mL). The results indicated that the elimination of benzyl group from the -benzyltetrahydroquinolines derivatives, as well as the introduction of a hydroxyl group in the 4-aryl substituent caused a significant improvement in the antifungal activity. These results were supplemented by the in silicoprediction; most of the tetrahydroquinolines evaluated showed high bioavailability, high drugs score and low potential risk.
Los magazines de actualidad basados en el infoentretenimiento: nuevos rasgos del lenguaje audiovisual en el periodismo televisivo
Authors: Ortells Badenes Sara
Published: September 2015

La aparición del infoentretenimiento ha originado diferentes cambios en el tratamiento de la información televisiva. Su implantación se asocia con el aumento del peso de las noticias de temática suave, y con la transformación del tratamiento de las noticias duras. Sus efectos también afectan al estilo utilizado para presentar la actualidad.

Este artículo se centra exclusivamente en determinar las características formales de un tipo concreto de programas con base de infoentretenimiento, los magazines de actualidad realizados en directo. Para ello, se han estudiado, mediante la técnica de análisis de contenido cuantitativo, cuatro programas de esta índole del panorama televisivo español.

Los resultados obtenidos determinan que las conexiones en directo, el movimiento de cámara continuo y el ritmo de montaje rápido se consolidan como los pilares del lenguaje audiovisual utilizado por esta nueva generación de programas.
“Tempos líquidos”: desafio para a nova evangelização
Authors: Costa Valeriano Dos santos
Published: September 2015

Diante da urgência da nova evangelização,intuída pelo Concílio Ecumênico Vaticano II elevada avante pelo magistério supremo da Igreja Católica, este artigo aprofunda a questão docontexto atual, que é o palco da evangelização. Paraisto, o artigo recorre ao conceito de “modernidade líquida”, do sociólogo Zigmunt Bauman, como escolha deliberada, a fim de apresentar a extensãodo problema e favorecer o debate que a Cátedra João Paulo II para a Nova Evangelização, da Pontifícia Universidade Católica de São Paulo, pretende incrementar.
Barrios Afro en Quito: identidades, representaciones y multiterritorialidades
Authors: Vera Santos Rocío Elizabeth
Published: September 2015

El presente artículo tiene como objetivo evidenciar los procesos de construcción de identidades étnicas y sus múltiples espacios de referencia identitaria considerando particularmente los aportes teóricos de Stuart Hall sobre “articulaciones identitarias” y de Rogério Haesbaert sobre “multiterritorialidades”. A fin de evidenciar estos procesos se realizó un estudio etnográfico en el barrio Caminos a la Libertad ubicado al noroccidente de Quito, se recolectó información a través de la observación participante y entrevistas semiestructuradas. Se partió por considerar que las identidades étnicas no están ancladas a un determinado territorio, y que su construcción es dinámica y en constante articulación con categorías como la raza, clase y género. Esta articulación muestra a su vez las distintas formas de crear fronteras entre los grupos pero también la agencia y subjetividad de los colectivos al fundar organizaciones, demandar políticas y generar acciones locales y globales.
Transformações na Atenção à Saúde Indígena: Tensões e Negociações em um Contexto Indígena Brasileiro
Authors: Diehl Eliana Elisabeth , Langdon Esther Jean
Published: September 2015

En los países de América Latina, los programas y políticas públicas dirigidos a la salud indígena han repercutido en nuevos papeles y espacios de frontera. Abordando la participación indígena en la atención primaria a la salud, analizamos las tensiones y negociaciones antes y después de la implantación del Subsistema de Atención a Salud Indígena en Brasil, trayendo como ejemplo una Tierra Indígena Kaingáng (TIK) del sur del país. Anterior a la implantación del Subsistema, la definición y ejecución de los servicios en esta TIK se caracterizaban por la fuerte presencia de indígenas ligados al líder indígena político y por la débil presencia de las instituciones. A partir de 2000, el subsistema empieza a envolver diferentes segmentos públicos y privados. En la TIK, el papel de una organización Kaingáng estaba repleto de ambigüedades y paradojas, pues al mismo tiempo que era una oportunidad para un mayor protagonismo en los espacios de negociación creados por el Estado, estaba sometido a las prioridades definidas en espacios exteriores al grupo étnico.
La caridad como criterio hermenéutico. Una aproximación a la comprensión de la unidad del De doctrina christiana de San Agustín
Authors: Unger Parra Biviana
Published: September 2015

El De doctrina christiana es una de las obras más importantes de San Agustín, no solo por la reflexión y el trabajo hermenéutico que propone, sino por su particular carácter, pues su composición da cuenta del desarrollo vital e intelectual del autor a lo largo de dos decenios. Un gran sector de la crítica afirma que esta obra debe entenderse como un conjunto formado por dos partes irreconciliables entre sí, aquella escrita en el 396, de carácter hermenéutico y, aquella compuesta en el 426 dedicada a la exposición de la retórica y la doctrina de la gracia. Si bien no debe desconocerse la diferencia que existe entre las dos partes de la obra, es necesario buscar un punto de confluencia del cual no solo depende la unidad de la obra, sino también la de la entera cultura cristiana.
Gabriel García márquez y la ética en Cien años de soledad – I
Authors: Herrera Molina, S.J, Luis Carlos
Published: September 2015

Esta reflexión acerca de la ética en Cien años de soledad se divide en dos grandes partes y se publica en dos entregas. En esta, la primera, el autor hace un recorrido, gracias al método intertextual, por la estructura, los personajes y la temática de obra para argumentar que la ética descrita por García Márquez tiene origen en los mitos bíblicos, y que su empleo constituye una herramienta que le da unidad a la obra y le permite al autor reflejar sin tapujos la condición humana.
Source depth estimation based on synthetic aperture beamfoming for a moving source
Authors: Yang T. C.
Published: September 2015

A continuous wave signal received on a single hydrophone from a moving source is beamformed using the synthetic aperture created by the source, where the signal at each range is steered by a range-dependent phase, relative to the starting point. The range increment (aperture) is determined based on the Doppler shift estimated from the data, knowing the original signal frequency. Given a sufficient signal-to-noise ratio, the source depth can be estimated from the beam output, assuming knowledge of the mode depth functions based on the nominal sound speed and bottom profile in the area. The method is illustrated with simulated data and at-sea data. For real data, the signal phase contains a random, incoherent component caused by the (random) source motion and media fluctuations in addition to the deterministic range-dependent component due to source range change. A phase locked loop is introduced to remove the random component assuming that the random component fluctuates faster with time than the range-dependent phase. When a vertical array of receivers are available covering the depth span of interest, the beam output can be used directly to estimate the source depth. In this case, no knowledge of the acoustic environment is needed.
Mindfulness and Its Relationship With Perceived Stress, Affect, and Burnout in Elite Junior Athletes
Authors: Gustafsson Henrik , Skoog Therése , Davis Paul , Kenttä Göran , Haberl Peter
Published: September 2015

The purpose of this study was to examine the relationship between dispositional mindfulness and burnout and whether this relationship is mediated by perceived stress, negative affect, and positive affect in elite junior athletes. Participants were 233 (123 males and 107 females) adolescent athletes, ranging in age from 15–19 years (M = 17.50; SD = 1.08). Bivariate correlations revealed that mindfulness had a significant negative relationship with both perceived stress and burnout. To investigate mediation, we employed nonparametric bootstrapping analyses. These analyses indicated that positive affect fully mediated links between mindfulness and sport devaluation. Further, positive affect and negative affect partially mediated the relationships between mindfulness and physical/emotional exhaustion, as well as between mindfulness and reduced sense of accomplishment. The results point toward mindfulness being negatively related to burnout in athletes and highlight the role of positive affect. Future research should investigate the longitudinal effect of dispositional mindfulness on stress and burnout.
Adaptive regulation of mammary growth
Authors: VanHook Annalisa M.
Published: September 2015

The adaptive immune response restrains epithelial branching in the developing mammary gland.
Remission by melatonin
Authors: Ferrarelli Leslie K.
Published: September 2015

Fewer daylight hours in winter increases melatonin production to promote anti-inflammatory relief in multiple sclerosis patients.
Cell Wall Recycling-Linked Coregulation of AmpC and PenB β-Lactamases through
ampD
Mutations in Burkholderia cenocepacia
Authors: Hwang Junghyun , Kim Heenam Stanley
Published: September 2015

In many Gram-negative pathogens, mutations in the key cell wall-recycling enzyme AmpD (N-acetyl-anhydromuramyl-
l
-alanine amidase) affect the activity of the regulator AmpR, which leads to the expression of AmpC β-lactamase, conferring resistance to expanded-spectrum cephalosporin antibiotics.
Burkholderia cepacia
complex (Bcc) species also have these Amp homologs; however, the regulatory circuitry and the nature of causal
ampD
mutations remain to be explored. A total of 92
ampD
mutants were obtained, representing four types of mutations: single nucleotide substitution (causing an amino acid substitution or antitermination of the enzyme), duplication, deletion, and IS element insertion. Duplication, which can go through reversion, was the most frequent type. Intriguingly, mutations in
ampD
led to the induction of two β-lactamases, AmpC and PenB. Coregulation of AmpC and PenB in
B. cenocepacia
, and likely also in many Bcc species with the same gene organization, poses a serious threat to human health. This resistance mechanism is of evolutionary optimization in that
ampD
is highly prone to mutations allowing rapid response to antibiotic challenge, and many of the mutations are reversible in order to resume cell wall recycling when the antibiotic challenge is relieved.
Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae
Authors: Euba Begoña , Moleres Javier , Segura Víctor , Viadas Cristina , Morey Pau , Moranta David , Leiva José , de-Torres Juan Pablo , Bengoechea José Antonio , Garmendia Junkal
Published: September 2015

Therapies that are safe, effective, and not vulnerable to developing resistance are highly desirable to counteract bacterial infections. Host-directed therapeutics is an antimicrobial approach alternative to conventional antibiotics based on perturbing host pathways subverted by pathogens during their life cycle by using host-directed drugs. In this study, we identified and evaluated the efficacy of a panel of host-directed drugs against respiratory infection by nontypeable
Haemophilus influenzae
(NTHi). NTHi is an opportunistic pathogen that is an important cause of exacerbation of chronic obstructive pulmonary disease (COPD). We screened for host genes differentially expressed upon infection by the clinical isolate NTHi375 by analyzing cell whole-genome expression profiling and identified a repertoire of host target candidates that were pharmacologically modulated. Based on the proposed relationship between NTHi intracellular location and persistence, we hypothesized that drugs perturbing host pathways used by NTHi to enter epithelial cells could have antimicrobial potential against NTHi infection. Interfering drugs were tested for their effects on bacterial and cellular viability, on NTHi-epithelial cell interplay, and on mouse pulmonary infection. Glucocorticoids and statins lacked
in vitro
and/or
in vivo
efficacy. Conversely, the sirtuin-1 activator resveratrol showed a bactericidal effect against NTHi, and the PDE4 inhibitor rolipram showed therapeutic efficacy by lowering NTHi375 counts intracellularly and in the lungs of infected mice. PDE4 inhibition is currently prescribed in COPD, and resveratrol is an attractive geroprotector for COPD treatment. Together, these results expand our knowledge of NTHi-triggered host subversion and frame the antimicrobial potential of rolipram and resveratrol against NTHi respiratory infection.
Cefepime Therapy for Monomicrobial Enterobacter cloacae Bacteremia: Unfavorable Outcomes in Patients Infected by Cefepime-Susceptible Dose-Dependent Isolates
Authors: Lee Nan-Yao , Lee Ching-Chi , Li Chia-Wen , Li Ming-Chi , Chen Po-Lin , Chang Chia-Ming , Ko Wen-Chien
Published: September 2015

A new category of cefepime susceptibility, susceptible dose dependent (SDD), for
Enterobacteriaceae
, has been suggested to maximize its clinical use. However, clinical evidence supporting such a therapeutic strategy is limited. A retrospective study of 305 adults with monomicrobial
Enterobacter cloacae
bacteremia at a medical center from 2008 to 2012 was conducted. The patients definitively treated with
in vitro
active cefepime (cases) were compared with those treated with a carbapenem (controls) to assess therapeutic effectiveness. The 30-day crude mortality rate is the primary endpoint, and clinical prognostic factors are assessed. Of 144 patients receiving definitive cefepime or carbapenem therapy, there were no significant differences in terms of age, sex, comorbidity, source of bacteremia, disease severity, or 30-day mortality (26.4% versus 22.2%;
P
= 0.7) among those treated with cefepime (
n
= 72) or a carbapenem (
n
= 72). In the multivariate analysis, the presence of critical illness, rapidly fatal underlying disease, extended-spectrum beta-lactamase (ESBL) producers, and cefepime-SDD (cefepime MIC, 4 to 8 μg/ml) isolates was independently associated with 30-day mortality. Moreover, those infected by cefepime-SDD isolates with definitive cefepime therapy had a higher mortality rate than those treated with a carbapenem (5/7 [71.4%], versus 2/11 [18.2%];
P
= 0.045). Cefepime is one of the therapeutic alternatives for cefepime-susceptible
E. cloacae
bacteremia but is inefficient for cases of cefepime-SDD
E. cloacae
bacteremia compared with carbapenem therapy.
Evaluation of the Rapidec Carba NP Test Kit for Detection of Carbapenemase-Producing Gram-Negative Bacteria
Authors: Garg Atul , Garg Jaya , Upadhyay G. C. , Agarwal Anurag , Bhattacharjee Amitabha
Published: September 2015

Recently, bioMérieux, France, introduced the Rapidec Carba NP test kit for rapid detection of carbapenemase-producing Gram-negative bacteria. This kit was evaluated in this study, and we report sensitivity, specificity, and positive and negative predictive values of 92.6%, 96.2%, 95.83%, and 92.6%, respectively. The test was easy to perform and interpret and relatively inexpensive ($5/Rs 300 per test) and provides a practical solution for early detection of carbapenemase-producing, multidrug-resistant Gram-negative bacteria.
Chlamydial Plasmid-Encoded Virulence Factor Pgp3 Neutralizes the Antichlamydial Activity of Human Cathelicidin LL-37
Authors: Hou Shuping , Dong Xiaohua , Yang Zhangsheng , Li Zhongyu , Liu Quanzhong , Zhong Guangming
Published: September 2015

Chlamydia trachomatisinfection in the lower genital tract can ascend to and cause pathologies in the upper genital tract, potentially leading to severe complications, such as tubal infertility. However, chlamydial organisms depleted of plasmid or deficient in the plasmid-encoded Pgp3 are attenuated in ascending infection and no longer are able to induce the upper genital tract pathologies, indicating a significant role of Pgp3 in chlamydial pathogenesis. We now report thatC. trachomatisPgp3 can neutralize the antichlamydial activity of human cathelicidin LL-37, a host antimicrobial peptide secreted by both genital tract epithelial cells and infiltrating neutrophils. Pgp3 bound to and formed stable complexes with LL-37. We further showed that the middle region of Pgp3 (Pgp3m) was responsible for both the binding to and neutralization of LL-37, suggesting that Pgp3m can be targeted for attenuating chlamydial pathogenicity or developed for blocking LL-37-involved non-genital-tract pathologies, such as rosacea and psoriasis. Thus, the current study has provided significant information for both understanding the mechanisms of chlamydial pathogenesis and developing novel therapeutic agents.
Important Contribution of the Novel Locus
comEB
to Extracellular DNA-Dependent Staphylococcus lugdunensis Biofilm Formation
Authors: Rajendran Nithya Babu , Eikmeier Julian , Becker Karsten , Hussain Muzaffar , Peters Georg , Heilmann Christine
Published: September 2015

The coagulase-negative species
Staphylococcus lugdunensis
is an emerging cause of serious and potentially life-threatening infections, such as infective endocarditis. The pathogenesis of these infections is characterized by the ability of
S. lugdunensis
to form biofilms on either biotic or abiotic surfaces. To elucidate the genetic basis of biofilm formation in
S. lugdunensis
, we performed transposon (Tn
917
) mutagenesis. One mutant had a significantly reduced biofilm-forming capacity and carried a Tn
917
insertion within the competence gene
comEB
. Site-directed mutagenesis and subsequent complementation with a functional copy of
comEB
verified the importance of
comEB
in biofilm formation. In several bacterial species, natural competence stimulates DNA release via lysis-dependent or -independent mechanisms. Extracellular DNA (eDNA) has been demonstrated to be an important structural component of many bacterial biofilms. Therefore, we quantified the eDNA in the biofilms and found diminished eDNA amounts in the
comEB
mutant biofilm. High-resolution images and three-dimensional data obtained via confocal laser scanning microscopy (CSLM) visualized the impact of the
comEB
mutation on biofilm integrity. The
comEB
mutant did not show reduced expression of autolysin genes, decreased autolytic activities, or increased cell viability, suggesting a cell lysis-independent mechanism of DNA release. Furthermore, reduced amounts of eDNA in the
comEB
mutant biofilms did not result from elevated levels or activity of the
S. lugdunensis
thermonuclease NucI. In conclusion, we defined here, for the first time, a role for the competence gene
comEB
in staphylococcal biofilm formation. Our findings indicate that
comEB
stimulates biofilm formation via a lysis-independent mechanism of DNA release.
The Majority of 9,729 Group A Streptococcus Strains Causing Disease Secrete SpeB Cysteine Protease: Pathogenesis Implications
Authors: Olsen Randall J. , Raghuram Anjali , Cantu Concepcion , Hartman Meredith H. , Jimenez Francisco E. , Lee Susan , Ngo Ashley , Rice Kelsey A. , Saddington Deborah , Spillman Hannaka , Valson Chandni , Flores Anthony R. , Beres Stephen B. , Long S. Wesley , Nasser Waleed , Musser James M.
Published: September 2015

Group A streptococcus (GAS), the causative agent of pharyngitis and necrotizing fasciitis, secretes the potent cysteine protease SpeB. Several lines of evidence suggest that SpeB is an important virulence factor. SpeB is expressed in human infections, protects mice from lethal challenge when used as a vaccine, and contributes significantly to tissue destruction and dissemination in animal models. However, recent descriptions of mutations in genes implicated in SpeB production have led to the idea that GAS may be under selective pressure to decrease secreted SpeB protease activity during infection. Thus, two divergent hypotheses have been proposed. One postulates that SpeB is a key contributor to pathogenesis; the other, that GAS is under selection to decrease SpeB during infection. In order to distinguish between these alternative hypotheses, we performed casein hydrolysis assays to measure the SpeB protease activity secreted by 6,775 GAS strains recovered from infected humans. The results demonstrated that 84.3% of the strains have a wild-type SpeB protease phenotype. The availability of whole-genome sequence data allowed us to determine the relative frequencies of mutations in genes implicated in SpeB production. The most abundantly mutated genes were direct transcription regulators. We also sequenced the genomes of 2,954 GAS isolates recovered from nonhuman primates with experimental necrotizing fasciitis. No mutations that would result in a SpeB-deficient phenotype were identified. Taken together, these data unambiguously demonstrate that the great majority of GAS strains recovered from infected humans secrete wild-type levels of SpeB protease activity. Our data confirm the important role of SpeB in GAS pathogenesis and help end a long-standing controversy.
Differential Influence of Nutrient-Starved Mycobacterium tuberculosis on Adaptive Immunity Results in Progressive Tuberculosis Disease and Pathology
Authors: Dietrich Jes , Roy Sugata , Rosenkrands Ida , Lindenstrøm Thomas , Filskov Jonathan , Rasmussen Erik Michael , Cassidy Joseph , Andersen Peter
Published: September 2015

When infected with
Mycobacterium tuberculosis
, most individuals will remain clinically healthy but latently infected. Latent infection has been proposed to partially involve
M. tuberculosis
in a nonreplicating stage, which therefore represents an
M. tuberculosis
phenotype that the immune system most likely will encounter during latency. It is therefore relevant to examine how this particular nonreplicating form of
M. tuberculosis
interacts with the host immune system. To study this, we first induced a state of nonreplication through prolonged nutrient starvation of
M. tuberculosis
in vitro
. This resulted in nonreplicating persistence even after prolonged culture in phosphate-buffered saline. Infection with either exponentially growing
M. tuberculosis
or nutrient-starved
M. tuberculosis
resulted in similar lung CFU levels in the first phase of the infection. However, between week 3 and 6 postinfection, there was a very pronounced increase in bacterial levels and associated lung pathology in nutrient-starved-
M. tuberculosis
-infected mice. This was associated with a shift from CD4 T cells that coexpressed gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) or IFN-γ, TNF-α, and interleukin-2 to T cells that only expressed IFN-γ. Thus, nonreplicating
M. tuberculosis
induced through nutrient starvation promotes a bacterial form that is genetically identical to exponentially growing
M. tuberculosis
yet characterized by a differential impact on the immune system that may be involved in undermining host antimycobacterial immunity and facilitate increased pathology and transmission.
Mouse Model for Sublethal Leptospira interrogans Infection
Authors: Richer Luciana , Potula Hari-Hara , Melo Rita , Vieira Ana , Gomes-Solecki Maria
Published: September 2015

Although
Leptospira
can infect a wide range of mammalian species, most studies have been conducted in golden Syrian hamsters, a species particularly sensitive to acute disease. Chronic disease has been well characterized in the rat, one of the natural reservoir hosts. Studies in another asymptomatic reservoir host, the mouse, have occasionally been done and have limited infection to mice younger than 6 weeks of age. We analyzed the outcome of sublethal infection of C3H/HeJ mice older than age 10 weeks with
Leptospira interrogans
serovar Copenhageni. Infection led to bloodstream dissemination of
Leptospira
, which was followed by urinary shedding, body weight loss, hypothermia, and colonization of the kidney by live spirochetes 2 weeks after infection. In addition,
Leptospira
dissemination triggered inflammation in the kidney but not in the liver or lung, as determined by increased levels of mRNA transcripts for the keratinocyte-derived chemokine, RANTES, macrophage inflammatory protein 2, tumor necrosis factor alpha, interleukin-1β, inducible nitric oxide synthase, interleukin-6, and gamma interferon in kidney tissue. The acquired humoral response to
Leptospira
infection led to the production of IgG mainly of the IgG1 subtype. Flow cytometric analysis of splenocytes from infected mice revealed that cellular expansion was primarily due to an increase in the levels of CD4
+
and double-negative T cells (not CD8
+
cells) and that CD4
+
T cells acquired a CD44
high
CD62L
low
effector phenotype not accompanied by increases in memory T cells. A mouse model for sublethal
Leptospira
infection allows understanding of the bacterial and host factors that lead to immune evasion, which can result in acute or chronic disease or resistance to infection (protection).
Evolution of Mycolic Acid Biosynthesis Genes and Their Regulation during Starvation in Mycobacterium tuberculosis
Authors: Jamet Stevie , Quentin Yves , Coudray Coralie , Texier Pauline , Laval Françoise , Daffé Mamadou , Fichant Gwennaele , Cam Kaymeuang
Published: September 2015

Mycobacterium tuberculosis, the etiological agent of tuberculosis, is a Gram-positive bacterium with a unique cell envelope composed of an essential outer membrane. Mycolic acids, which are very-long-chain (up to C100) fatty acids, are the major components of this mycomembrane. The enzymatic pathways involved in the biosynthesis and transport of mycolates are fairly well documented and are the targets of the major antituberculous drugs. In contrast, only fragmented information is available on the expression and regulation of the biosynthesis genes. In this study, we report that thehadA,hadB, andhadCgenes, which code for the mycolate biosynthesis dehydratase enzymes, are coexpressed with three genes that encode proteins of the translational apparatus. Consistent with the well-established control of the translation potential by nutrient availability, starvation leads to downregulation of thehadABCgenes along with most of the genes required for the synthesis, modification, and transport of mycolates. The downregulation of a subset of the biosynthesis genes is partially dependent on RelMtb, the key enzyme of the stringent response. We also report the phylogenetic evolution scenario that has shaped the current genetic organization, characterized by the coregulation of thehadABCoperon with genes of the translational apparatus and with genes required for the modification of the mycolates.

IMPORTANCEMycobacterium tuberculosisinfects one-third of the human population worldwide, and despite the available therapeutic arsenal, it continues to kill millions of people each year. There is therefore an urgent need to identify new targets and develop a better understanding of how the bacterium is adapting itself to host defenses during infection. A prerequisite of this understanding is knowledge of how this adaptive skill has been implanted by evolution. Nutrient scarcity is an environmental condition the bacterium has to cope with during infection. In many bacteria, adaptation to starvation relies partly on the stringent response.M. tuberculosis's unique outer membrane layer, the mycomembrane, is crucial for its viability and virulence. Despite its being the target of the major antituberculosis drugs, only scattered information exists on how the genes required for biosynthesis of the mycomembrane are expressed and regulated during starvation. This work has addressed this issue as a step toward the identification of new targets in the fight againstM. tuberculosis.
Fine structure and evolution of the rat serum albumin gene.
Authors: Sargent T D , Jagodzinski L L , Yang M , Bonner J
Published: September 2015

The exons, their boundaries, and approximately half of the intronic deoxyribonucleic acid of the rat serum albumin gene were sequenced. In addition to the 14 exons identified earlier by R-loop analysis, a small exon was detected between the "leader" exon (Z) and exon B. The leader exon encoded the 5'-untranslated portion of albumin messenger ribonucleic acid and the "pre-pro" oligopeptide present on the nascent protein. The sites of initiation and termination of transcription were tentatively identified by comparison of the 5' and 3' gene-flanking sequences with those of other eucaryotic genes. All 28 intron/exon junctions conformed to the "GT-AG rule" (Breathnach et al., Proc. Natl. Acad. Sci. 75:4853-4857, 1978). The three homologous domains of albumin were encoded by three subgenes that consisted of four exons each and evolved by intragenic duplication of a common ancestor. The second and forth exons of each subgene appeared to be the result of an even earlier duplication event. We propose a model for the evolution of this gene that accounts for the observed patterns of exon size and homology.
Selection of mutant Chinese hamster ovary cells altered glycoproteins by means of tritiated fucose suicide.
Authors: Hirschberg C B , Baker R M , Perez M , Spencer L A , Watson D
Published: September 2015

Mutant Chinese hamster ovary cells altered in glycoproteins have been isolated by selecting for ability to survive exposure to [6-3H]fucose. Mutagenized wild-type cells were permitted to incorporate [3H]fucose to approximately 1 cpm of trichloroacetic acid-insoluble radioactivity per cell and then frozen for several days to accumulate radiation damage. The overall viability of the population was reduced by 5- to 50-fold. Four consecutive selection cycles were carried out. The surviving cells were screened by replica plating-fluorography for clones showing decreased incorporation of fucose into trichloroacetic acid-insoluble macromolecules. Considerable enrichment for cells deficient in fucose uptake or incorporation into proteins (or both) was found in populations surviving the later selection cycles. Two mutant clones isolated after the fourth selection cycle had the same doubling time as the wild type, but contained only 30 to 40% as much fucose bound to proteins as the wild type. Sialic acid contents of the mutants and the wild type were similar. The mutants differed quantitatively and qualitatively from the wild type and from each other with respect to total glycoprotein profiles as visualized by sodium dodecyl sulfate gel electrophoresis. Differences were also found in resistances to cytotoxicity of lectins such as concanavalin A and wheat germ agglutinin.
Nature and timing of some sporulation-specific protein changes in Saccharomyces cerevisiae.
Authors: Wright J F , Ajam N , Dawes I W
Published: September 2015

During meiosis and spore formulation in Saccharomyces cerevisiae, changes that occur in a/alpha diploids, but not in isogenic nonsporulating a/a diploids, have been detected in cellular polypeptides. These were found by the technique of prelabeling growing cells with 35SO4(2-) and suspending them in sulfur-free sporulation medium. Under the conditions used, about 400 polypeptides were detected by two-dimensional gel electrophoresis, and 45 were altered during sporulation; of these, 21 changes were specific to a/alpha strains. These alterations were mainly due to the appearance of new polypeptides or to marked increases in the concentrations of a few polypeptides produced during vegetative growth. They could have been due either to modifications of existing polypeptides present in growing cells or to de novo synthesis of new gene products. They occurred at characteristic times during sporulation; whereas the majority of changes took place early (within the first 6 h in sporulation conditions), there were several changes characterizing the later stages of sporulation. Ten of the 35SO4(2-)-labeled polypeptides were also labeled with 32P in the presence of [32P]orthophosphate; of these, three were previously found to be sporulation specific. One of these was phosphorylated at all stages of sporulation and was labeled when [32P]orthophosphate was added either during growth of the culture of 1 h after transfer to sporulation medium. Another was labeled in the same way by adding 32P at either time, so that by 7 h in sporulation medium it was phosphorylated, but was dephosphorylated by 24 h. The third sporulation-specific peptide was labeled in extracts prepared at 7 h in sporulation medium (but not at 24 h) when [32P]-orthophosphate was added during presporulation growth, but not when [32P]-orthophosphate was added 1 h after transfer of the culture to sporulation medium. This polypeptide appeared early during sporulation; it is probably phosphorylated as it appears and is dephosphorylated at some time between 7 h and 24 h of sporulation.