bluuebunny/crossref_metadata_2025 huggingface dataset:
Neonatal Iron Deficiency Causes Abnormal Phosphate Metabolism by Elevating FGF23 in Normal and ADHR Mice
Authors: Clinkenbeard Erica L , Farrow Emily G , Summers Lelia J , Cass Taryn A , Roberts Jessica L , Bayt Christine A , Lahm Tim , Albrecht Marjorie , Allen Matthew R , Peacock Munro , White Kenneth E
Published: July 2013

Fibroblast growth factor 23 (FGF23) gain of function mutations can lead to autosomal dominant hypophosphatemic rickets (ADHR) disease onset at birth, or delayed onset following puberty or pregnancy. We previously demonstrated that the combination of iron deficiency and a knock-in R176Q FGF23 mutation in mature mice induced FGF23 expression and hypophosphatemia that paralleled the late-onset ADHR phenotype. Because anemia in pregnancy and in premature infants is common, the goal of this study was to test whether iron deficiency alters phosphate handling in neonatal life. Wild-type (WT) and ADHR female breeder mice were provided control or iron-deficient diets during pregnancy and nursing. Iron-deficient breeders were also made iron replete. Iron-deficient WT and ADHR pups were hypophosphatemic, with ADHR pups having significantly lower serum phosphate (p < 0.01) and widened growth plates. Both genotypes increased bone FGF23 mRNA (>50 fold; p < 0.01). WT and ADHR pups receiving low iron had elevated intact serum FGF23; ADHR mice were affected to a greater degree (p < 0.01). Iron-deficient mice also showed increased Cyp24a1 and reduced Cyp27b1, and low serum 1,25-dihydroxyvitamin D (1,25D). Iron repletion normalized most abnormalities. Because iron deficiency can induce tissue hypoxia, oxygen deprivation was tested as a regulator of FGF23, and was shown to stimulate FGF23 mRNA in vitro and serum C-terminal FGF23 in normal rats in vivo. These studies demonstrate that FGF23 is modulated by iron status in young WT and ADHR mice and that hypoxia independently controls FGF23 expression in situations of normal iron. Therefore, disturbed iron and oxygen metabolism in neonatal life may have important effects on skeletal function and structure through FGF23 activity on phosphate regulation. © 2014 American Society for Bone and Mineral Research.
Set7/9 Impacts COL2A1 Expression Through Binding and Repression of SirT1 Histone Deacetylation
Authors: Oppenheimer Hanna , Kumar Ashok , Meir Hadar , Schwartz Israel , Zini Avi , Haze Amir , Kandel Leonid , Mattan Yoav , Liebergall Meir , Dvir-Ginzberg Mona
Published: July 2013

Type II collagen is a key cartilaginous extracellular protein required for normal endochondral development and cartilage homeostasis. COL2A1 gene expression is positively regulated by the NAD-dependent protein deacetylase Sirtuin 1 (SirT1), through its ability to bind chromatin regions of the COL2A1 promoter and enhancer. Although SirT1/Sox9 binding on the enhancer site of COL2A1 was previously demonstrated, little is known about its functional role on the gene promoter site. Here, we examined the mechanism by which promoter-associated SirT1 governs COL2A1 expression. Human chondrocytes were encapsulated in three-dimensional (3D) alginate beads where they exhibited upregulated COL2A1 mRNA expression and increased levels of SirT1 occupancy on the promoter and enhancer regions, when compared to monolayer controls. Chromatin immunoprecipitation (ChIP) analyses of 3D cultures showed augmented levels of the DNA-binding transcription factor SP1, and the histone methyltransferase Set7/9, on the COL2A1 promoter site. ChIP reChIP assays revealed that SirT1 and Set7/9 form a protein complex on the COL2A1 promoter region of 3D-cultured chondrocytes, which also demonstrated elevated trimethylated lysine 4 on histone 3 (3MeH3K4), a hallmark of Set7/9 methyltransferase activity. Advanced passaging of chondrocytes yielded a decrease in 3MeH3K4 and Set7/9 levels on the COL2A1 promoter and reduced COL2A1 expression, suggesting that the SirT1/Set7/9 complex is preferentially formed on the COL2A1 promoter and required for gene activation. Interestingly, despite SirT1 occupancy, its deacetylation targets (ie, H3K9/14 and H4K16) were found acetylated on the COL2A1 promoter of 3D-cultured chondrocytes. A possible explanation for this phenotype is the enrichment of the histone acetyltransferases P300 and GCN5 on the COL2A1 promoter of3 D-cultured chondrocytes. Our study indicates that Set7/9 prevents the histone deacetylase activity of SirT1, potentiating euchromatin formation on the promoter site of COL2A1 and resulting in morphology-dependent COL2A1 gene transactivation. © 2014 American Society for Bone and Mineral Research.
QUALITY OF LIFE AND SENSE OF COMMUNITY. A STUDY ON HEALTH AND PLACE OF RESIDENCE
Authors: Gattino Silvia , De Piccoli Norma , Fassio Omar , Rollero Chiara
Published: July 2013

The aim of the study is to assess the predictive role of the affective link with the place of residence (place attachment) and the perception of one's own community of residence (sense of community) on health and quality of life. Other variables were considered: size of place of residence, income, level of education, marital status, age, and gender. Participants included 344 adult subjects living in Piedmont, Italy. The instruments used were the Italian Sense of Community Scale, the Residential Attachment Scale, and the Italian version of the WHOQOL‐BREF questionnaire. Data showed that (a) quality of life is affected by sense of community, but not by place attachment, and (b) living in a small town enhances the environmental, psychological, and relational quality of life.
BONDING AND BRIDGING: TRANSITION TO SCHOOL AND SOCIAL CAPITAL FORMATION AMONG A COMMUNITY OF INDIGENOUS AUSTRALIAN CHILDREN
Authors: Thorpe Karen , Bell‐Booth Rachel , Staton Sally , Thompson Catherine
Published: July 2013

This study reports on an intervention program designed to facilitate transition to school of a whole community of Indigenous Australian children who had previously not been attending. The children were from families displaced from their traditional lands and experienced on‐going social marginalisation and transience. A social capital framework was employed to track change in the children's social inclusion and family‐school engagement for two years, from school entry. Sociometric measurement and interview techniques were applied to assess the children's social connectedness and peer relationship quality. Using these data, analyses examined whether bonding within the group supported or inhibited formation of new social relationships. Although transience disrupted attendance, there was a group trend towards increased social inclusion with some evidence that group bonds supported bridging to new social relationships. Change in family‐school engagement was tracked using multi‐informant interviews. Limited engagement between school and families presented an on‐going challenge to sustained educational engagement.
REDUCING NO‐SHOW BEHAVIOR AT A COMMUNITY MENTAL HEALTH CENTER
Authors: van Dieren Q. , Rijckmans M.J.N. , Mathijssen J.J.P. , Lobbestael J. , Arntz A.R.
Published: July 2013

The objective of this study was to examine whether an easy to apply no‐show policy can substantially reduce no‐show behavior of 16–25‐year‐old clients undergoing individual outpatient treatment at a community mental health center. After introduction of the new no‐show policy, the no‐show percentage was significantly reduced with 32.1%. This reduction was not due to terminating significantly more treatments of clients with no‐show behavior. It seems likely that this easy‐to‐apply no‐show policy can substantially reduce no‐show behavior of clients with a broad variety of mental disorders undergoing individual outpatient treatment.
THE RELATIONSHIP BETWEEN PSYCHOLOGICAL EMPOWERMENT AND ORGANIZATIONAL IDENTIFICATION
Authors: Prati Gabriele , Zani Bruna
Published: July 2013

The purpose of the study was to examine the relationship between psychological empowerment and organizational identification as well as the impact that these two constructs have on turnover intention and job satisfaction (focal outcomes). Participants were 5,195 employees from 730 teams in 6 Italian local health organizations. Two competing conceptual models were tested for goodness of fit using multilevel path analysis. In the first model, psychological empowerment predicts organizational identification, which, in turn, predicts focal outcomes. In the second model, organizational identification predicts psychological empowerment, which, in turn, predicts focal outcomes. Fit indices of the path analysis indicated that the second model obtained the best fit to the data as compared with other models. Moreover, mediation analysis showed that psychological empowerment mediated the relationship between organizational identification and focal outcomes.
ALCOHOL ENVIRONMENT, PERCEIVED SAFETY, AND EXPOSURE TO ALCOHOL, TOBACCO, AND OTHER DRUGS IN EARLY ADOLESCENCE
Authors: Milam Adam J. , Furr‐Holden C. Debra , Bradshaw Catherine P. , Webster Daniel W. , Cooley‐Strickland Michele C. , Leaf Philip J.
Published: July 2013

This study examined the association between the count of alcohol outlets around children's homes and opportunities to use alcohol, tobacco, and other drugs (ATOD) during preadolescence. Data were collected in 2007 from 394 Baltimore City children aged 8–13 years (86% African American). Participants’ residential address and alcohol outlet data were geocoded with quarter mile (i.e., walking distance) buffers placed around each participant's home to determine the number of outlets within walking distance. The unadjusted logistic regression models revealed that each unit increase in the number of alcohol outlets was associated with a 14% increase in the likelihood of children seeing people selling drugs (odds ratio [OR] = 1.14, p = .04) and a 15% increase in the likelihood of seeing people smoking marijuana (OR = 1.15, p < .01). After adjusting for neighborhood physical disorder, the relationship between alcohol outlets and seeing people selling drugs and seeing people smoking marijuana was fully attenuated. These results suggest that alcohol outlets are one aspect of the larger environmental context that is related to ATOD exposure in children. Future studies should examine the complex relationship between neighborhood physical disorder and the presence of alcohol outlets.
THE INFLUENCE OF RACE AND ETHNICITY IN CLIENTS’ EXPERIENCES OF MENTAL HEALTH TREATMENT
Authors: Meyer Oanh L. , Zane Nolan
Published: July 2013

Clinicians and researchers have pointed to the need for culturally sensitive mental health interventions. Yet it has not been determined if the inclusion of cultural elements affects the way mental health clients experience services. This study examined 102 clients who had received mental health treatment from outpatient mental health clinics to investigate whether culturally related elements involving race and ethnicity were important to clients and whether they were related to client satisfaction and perceived treatment outcomes. Ethnic minority clients generally felt that issues regarding race and ethnicity were more important than did White clients. When these elements were considered important but were not included in their care, clients were less satisfied with treatment. Consistent with the notion of cultural responsiveness, these findings provide empirical evidence that culturally relevant aspects of the mental health service experience are salient to ethnic minority clients and can affect how they respond to services.
Statistical analysis of the plasmaspheric plume at the magnetopause
Authors: Walsh B. M. , Sibeck D. G. , Nishimura Y. , Angelopoulos V.
Published: July 2013

During times of enhanced magnetospheric convection, cold dense plasma from the plasmasphere can form a plume extending sunward toward the dayside magnetopause. A statistical study is presented of cold high‐density plasmaspheric plasma at the magnetopause. Observations from the Time History of Events and Macroscale Interactions (THEMIS) spacecraft show the plume to be present at the dayside magnetopause during 12.5% (148 of 1184) of the crossings. Its most common location in magnetic local time when contacting the magnetopause is at 13.6 h. The magnetopause crossings show evidence for reconnection in 68% of events with the plume while only 47% of events without plume. Although the plume is more likely to be observed at the magnetopause when reconnection is occurring, the typical reconnection jet velocity is lower for plume events than nonplume events, indicating the presence of the plume may be slowing the efficiency of the reconnection process.
Changes in elastic wave velocity and rock microstructure due to basalt‐CO2‐water reactions
Authors: Adam Ludmila , van Wijk Kasper , Otheim Thomas , Batzle Michael
Published: July 2013

The chemical interaction between carbon dioxide, water, and basalt is a common process in the earth, which results in the dissolution of primary minerals that later precipitate as alteration minerals. This occurs naturally in volcanic settings, but more recently basalts have been suggested as reservoirs for sequestration of anthropogenic CO2. In both the natural and man‐made cases, rock‐fluid reactions lead to the precipitation of carbonates. Here, we quantify changes in ultrasonic wave speeds, associated with changes in the frame of whole‐rock basalts, as CO2 and basalt react. After 30weeks of reactions and carbonate precipitation, the ultrasonic wave speed in dry basalt samples increases between 4% and 20% and permeability is reduced by up to an order of magnitude. However, porosity decreases only by 2% to 3%. The correlation between significant changes in wave speed and permeability indicates that a precipitate is developing in fractures and compliant pores. Thin sections, XRF‐loss on ignition, and water chemistry confirm this observation. This means time‐lapse seismic monitoring of a CO2‐water‐basalt system cannot assume invariance of the rock frame, as typically done in fluid substitution models. We conclude that secondary mineral precipitation causes a measurable change in the velocities of elastic waves in basalt‐water‐CO2 systems, suggesting that seismic waves could be used to remotely monitor future CO2 injection sites. Although monitoring these reactions in the field with seismic waves might be complicated due to the heterogeneous nature of basalt, quantifying the elastic velocity changes associated with rock alteration in a controlled laboratory experiment forms an important step toward field‐scale seismic monitoring.
Space‐time variability of the rainfall over the western Mediterranean region: A statistical analysis
Authors: Rysman J.‐F. , Verrier S. , Lemaître Y. , Moreau E.
Published: July 2013

This study aims at better understanding the space‐time statistical properties of rain over a Mediterranean region. To this end we analyzed temporal, spatial, and spatio‐temporal spectra of rain field maps provided by an X‐band radar situated in the southeast part of France. The database extends from 2009 to 2012 and has a spatial and temporal resolution of 1 km2 and 5 min. The analysis highlights several scaling regimes, which are interpreted in terms of meteorological structures (convective cells, mesoscale structures, and midlatitude cyclones). The analysis of spectra per month confirms the dependency of the spectral signature to the underlying meteorological process. Nevertheless, our results also reveal that for a given range of scales (20–45 min in time and 7–20 km in space), spectral slope is monthly invariant. It means that rain behaves identically, in terms of scaling, whatever the mechanism that generated it (convection, front). Moreover, spectral analysis shows that the temporal decorrelation scale is 10 days, which can possibly be related to the longest lifetime of a meteorological phenomenon in the region (i.e., about 10 days). An approach to compute the scaling anisotropy between space and time is proposed. It reveals that, over two distinct ranges of scales (7–20 km/20–45 min and 20–70 km/45 min–3 h), the scaling anisotropic coefficient is equal to 2. It also reveals that the ratio of spectral slope of 2‐D angle averaged spatial spectrum versus 1‐D temporal spectrum is equal to 1 over these ranges of scales. It suggests a similarity in the second‐order properties (e.g., correlation) of temporal and spatial rain field. All these results are important to better understand rainfall statistical behavior and could also be used for the development of downscaling schemes and the validation of numerical weather models.
Lifetime dependent flux into the lowermost stratosphere for idealized trace gases of surface origin
Authors: Holzer Mark , Polvani Lorenzo M.
Published: July 2013

The flux of idealized trace gases across the thermal tropopause is quantified as a function of their chemical lifetime using the Model of Atmospheric Transport and Chemistry (MATCH) driven by National Centers for Environmental Prediction (NCEP) reanalyses. The flux is computed in the limit of instant stratospheric chemical loss, and tropospheric chemistry is idealized as decay with a constant lifetime, τc. Emissions are idealized as time independent, with either a generic anthropogenic pattern or a uniform ocean source. We find that the globally averaged flux into the stratosphere normalized by surface emissions is ∼1% for τc= 8 days and ∼30% for τc ∼ 140 days, slowly approaching the long‐lived limit of balance between stratospheric sinks and surface sources. The qualitative τc dependence of the globally averaged flux is captured by a simple one‐dimensional model. The flux patterns computed with MATCH for the NCEP reanalyses are insensitive to τc and reveal preferred pathways into the stratosphere: The divergent circulation feeding isentropic cross‐tropopause transport, storm tracks in the winter hemisphere, and isentropic transport to high latitudes.
A revised 1000 year atmospheric δ13C‐CO2 record from Law Dome and South Pole, Antarctica
Authors: Rubino M. , Etheridge D. M. , Trudinger C. M. , Allison C. E. , Battle M. O. , Langenfelds R. L. , Steele L. P. , Curran M. , Bender M. , White J. W. C. , Jenk T. M. , Blunier T. , Francey R. J.
Published: July 2013

We present new measurements of δ13C of CO2 extracted from a high‐resolution ice core from Law Dome (East Antarctica), together with firn measurements performed at Law Dome and South Pole, covering the last 150 years. Our analysis is motivated by the need to better understand the role and feedback of the carbon (C) cycle in climate change, by advances in measurement methods, and by apparent anomalies when comparing ice core and firn air δ13C records from Law Dome and South Pole. We demonstrate improved consistency between Law Dome ice, South Pole firn, and the Cape Grim (Tasmania) atmospheric δ13C data, providing evidence that our new record reliably extends direct atmospheric measurements back in time. We also show a revised version of early δ13C measurements covering the last 1000 years, with a mean preindustrial level of −6.50‰. Finally, we use a Kalman Filter Double Deconvolution to infer net natural CO2 fluxes between atmosphere, ocean, and land, which cause small δ13C deviations from the predominant anthropogenically induced δ13C decrease. The main features found from the previous δ13C record are confirmed, including the ocean as the dominant cause for the 1940 A.D. CO2 leveling. Our new record provides a solid basis for future investigation of the causes of decadal to centennial variations of the preindustrial atmospheric CO2 concentration. Those causes are of potential significance for predicting future CO2 levels and when attempting atmospheric verification of recent and future global carbon emission mitigation measures through Coupled Climate Carbon Cycle Models.
THE CHANGING DONOR LANDSCAPE IN NICARAGUA: RISING COMPETITION ENHANCES OWNERSHIP AND FOSTERS COOPERATION
Authors: Walshe Roussel Lauren
Published: July 2013

This article informs our understanding of how emerging donors can influence development cooperation relationships and practices through the case of Nicaragua. Findings suggest that emerging donors present opportunities for development cooperation in Nicaragua. By spurring competitive pressures, they are introducing flexibility into what was formerly a traditional donor‐driven space, enhancing local ownership of the development agenda and fostering cooperation between donors. This case study also suggests that the distinction between traditional and emerging donors is increasingly blurry, illustrating the importance of looking beyond donor typologies to capture the dynamism of development actors and its influence on development trends. Copyright © 2013 John Wiley & Sons, Ltd.
EUROPE BEYOND AID: ASSESSING EUROPEAN COUNTRIES' INDIVIDUAL AND COLLECTIVE COMMITMENT TO DEVELOPMENT
Authors: Barder Owen , Clark Julia , Lépissier Alice , Reynolds Liza , Roodman David
Published: July 2013

We rank European countries' collective commitment to development on seven cross‐border issues: aid, trade, investment, migration, environment, security and technology. We calculate a consolidated score for 21 European countries and show that they perform well on aid and environment but lag the rest of the world on trade and technology. We find that Europe's approach to development energetically tackles the symptoms of poor economic opportunities for developing countries by providing relatively effective aid, but there is an opportunity to do more to tackle the underlying structural causes of poverty. Copyright © 2013 John Wiley & Sons, Ltd.
ARTICULATING GLOBAL PRESCRIPTIONS FOR HEALTH WITH LOCAL CONCEPTIONS OF WELL‐BEING AND RISK: THE CASE OF PHYSICAL ACTIVITY AND THE WORLD HEALTH ORGANISATION
Authors: Brangan Emer
Published: July 2013

If there is one thing that policy makers at the World Health Organisation and residents of the South African township of Langa are likely to agree on, it is that ‘just sitting’ is not good for you. The positions from which they approach this conclusion however differ profoundly. This research uses qualitative methods to investigate different conceptualisations of physical activity, health and well‐being, and the implications of these differences for policy on the prevention of non‐communicable diseases in low‐income and middle‐income countries, taking South Africa as a case study. Copyright © 2013 John Wiley & Sons, Ltd.
BUSAN AND BEYOND: SOUTH KOREA AND THE TRANSITION FROM AID EFFECTIVENESS TO DEVELOPMENT EFFECTIVENESS
Authors: Kim Eun Mee , Lee Jae Eun
Published: July 2013

The fourth High Level Forum on Aid Effectiveness (HLF‐4), held in Busan, South Korea drew the largest number as well as the most diverse group of participants ever. This paper examines the shift towards a new global development cooperation paradigm at the Busan HLF‐4; the new global partnership that emerged from Busan; and what South Korea brought to the global discourse on development cooperation as an emerging donor. Although it is premature to argue that a new paradigm was established at Busan, there was a clear political momentum for a shift from aid effectiveness to development effectiveness, a change that was advocated and promoted particularly by new actors such as South Korea. The Busan HLF‐4 and the post‐Busan process have highlighted the global role of new actors, with South Korea exemplifying through its own experience how aid can help bring about development, contributing to the global discourse on development cooperation and playing a bridging role between traditional and emerging donors. The changing dynamics of the world including the global financial crisis and climate change suggest that the global challenges are different from what had been expected when the HLF process and Millennium Development Goals were begun in the beginning of the 20th century. Thus, we recommend that global development cooperation discourse and activities that had been led by traditional Western donors need to find more effective ways of incorporating new actors and different modalities of development cooperation because the global challenges we face are grave. New development partners can bring to the table lessons, energies and capacities deriving from their own dramatic success in alleviating poverty and attaining development and their visibility as global development actors. Copyright © 2013 John Wiley & Sons, Ltd.
THE NEW DEVELOPMENT COOPERATION LANDSCAPE: ACTORS, APPROACHES, ARCHITECTURE
Authors: Gore Charles
Published: July 2013

The old aid architecture is being replaced by a more complex and diverse landscape of development cooperation in which there are new actors, new approaches and attempts to create an overarching architecture which, by embracing all, is expected to be more developmentally effective. The papers in this special issue address different aspects of the new landscape. This paper provides an overview of the landscape and summarizes the findings of the papers. It argues that they show that the new development cooperation landscape is characterized by both vibrant dynamism and systemic inertia and that to achieve progress in development cooperation, more support needs to be given to bottom–up processes of change which can generate effective development outcomes. Copyright © 2013 John Wiley & Sons, Ltd.
Tips for writing a case report for the novice author
Authors: Sun Zhonghua
Published: July 2013

A case report is a description of important scientific observations that are missed or undetectable in clinical trials. This includes a rare or unusual clinical condition, a previously unreported or unrecognized disease, unusual side effects to therapy or response to treatment, and unique use of imaging modalities or diagnostic tests to assist diagnosis of a disease. Generally, a case report should be short and focussed, with its main components being the abstract, introduction, case description, and discussion. This article discusses the essential components of a case report, with the aim of providing guidelines and tips to novice authors to improve their writing skills.
Local administration of alendronate reduced peri‐tunnel bone loss and promoted graft‐bone tunnel healing with minimal systemic effect on bone in contralateral knee
Authors: Lui Pauline Po Yee , Lee Yuk Wa , Mok Tsui Yu , Cheuk Yau Chuk
Published: July 2013

Continued systemic administration of alendronate was reported to reduce peri‐tunnel bone resorption and promoted graft‐bone tunnel healing at the early stage post‐anterior cruciate ligament (ACL) reconstruction. However, systemic increase in bone mineral density (BMD) in the contralateral intact knee was observed. We tested if single local administration of alendronate into the bone tunnel during ACL reconstruction could achieve similar benefits yet without the systemic effect on bone. Seventy‐two rats with unilateral ACL reconstruction were divided into three groups: saline, low‐dose (6 μg/kg) and mid‐dose (60 μg/kg) alendronate. For local administration, alendronate was applied to the bone tunnels for 2 min before graft insertion and repair. At weeks 2 and 6, the reconstructed complex was harvested for high‐resolution computed tomography (vivaCT) imaging followed by biomechanical test or histology. Our results showed that local administration of low‐dose alendronate showed comparable benefits on the reduction of peri‐tunnel bone loss, enhancement of bone tunnel mineralization, tunnel graft integrity, graft osteointegration and mechanical strength of the reconstructed complex at early stage post‐reconstruction, yet with minimal systemic effect on mineralized tissue at the contralateral intact knee. A single local administration of alendronate at the low‐dose therefore might be used to promote early tunnel graft healing post‐reconstruction. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1897–1906, 2013
Continuous‐wave vertically emitting photonic crystal terahertz laser
Authors: Diao Zhaolu , Bonzon Christopher , Scalari Giacomo , Beck Mattias , Faist Jérôme , Houdré Romuald
Published: July 2013

Compact semiconductor light sources with high performance continuous‐wave (CW) and single mode operation are highly demanded for many applications in the terahertz (THz) frequency range. Distributed feedback (DFB) and photonic crystal (PhC) quantum cascade (QC) lasers are amongst the leading candidates in this field. Absorbing boundary condition is a commonly used method to control the optical performance of a laser in double‐metal confinement. However, this approach increases the total loss in the device and results in a large threshold current density, limiting the CW maximum output power and operating temperature. In this letter, a robust surface emitting continuous‐wave terahertz QC laser is realized in a two‐dimensional PhC structure by a second order Bragg grating extractor that simultaneously provides the boundary condition necessary for mode selection. This results in a 3.12 THz single mode CW operation with a 3 mW output power and a maximum operation temperature (Tmax) of 100 K. Also, a highly collimated far‐field pattern is demonstrated, which is an important step towards real world applications.
Self‐phase‐locked degenerate femtosecond optical parametric oscillator based on BiB3O6
Authors: Ramaiah‐Badarla Venkata , Esteban‐Martin Adolfo , Ebrahim‐Zadeh Majid
Published: July 2013

A self‐phase‐locked degenerate femtosecond optical parametric oscillator (OPO) based on the birefringent nonlinear material, bismuth triborate, BiB3O6, synchronously‐pumped by a Kerr‐lens‐mode‐locked Ti:sapphire laser at 800 nm is described. By exploiting versatile phase‐matching properties of BiB3O6, including large spectral and angular acceptance for parametric generation and low group velocity dispersion in the optical xz plane, stable self‐phase‐locked degenerate OPO operation centered at 1600 nm is demonstrated using collinear type I (e → oo) interaction in a 1.5‐mm crystal at room temperature.

The degenerate OPO output spectrum extends over 46 nm (∼5.4 THz) with 190 fs pulse duration for input pump pulses of 155 fs with a bandwidth of 7 nm. Phase coherence between the pump and degenerate output is verified using f‐2f interferometry, and discrete frequency beats caused by different carrier‐envelope‐offset frequencies are measured using radio frequency measurements.

Photo shows a 1.5‐mm BiB3O6 crystal used as a nonlinear gain medium in a degenerate self‐phase‐locked femtosecond OPO operating at room temperature. The green beam is the result of non‐phase‐matched sum‐frequency mixing between the pump light and the sub‐harmonic OPO field at degeneracy.
Campylobacter jejuni colonization and population structure in urban populations of ducks and starlings in New Zealand
Authors: Mohan Vathsala , Stevenson Mark , Marshall Jonathan , Fearnhead Paul , Holland Barbara R. , Hotter Grant , French Nigel P.
Published: July 2013

A repeated cross‐sectional study was conducted to determine the prevalence of Campylobacter spp. and the population structure of C. jejuni in European starlings and ducks cohabiting multiple public access sites in an urban area of New Zealand. The country's geographical isolation and relatively recent history of introduction of wild bird species, including the European starling and mallard duck, create an ideal setting to explore the impact of geographical separation on the population biology of C. jejuni, as well as potential public health implications. A total of 716 starling and 720 duck fecal samples were collected and screened for C. jejuni over a 12 month period. This study combined molecular genotyping, population genetics and epidemiological modeling and revealed: (i) higher Campylobacter spp. isolation in starlings (46%) compared with ducks (30%), but similar isolation of C. jejuni in ducks (23%) and starlings (21%), (ii) significant associations between the isolation of Campylobacter spp. and host species, sampling location and time of year using logistic regression, (iii) evidence of population differentiation, as indicated by FST, and host‐genotype association with clonal complexes CC ST‐177 and CC ST‐682 associated with starlings, and clonal complexes CC ST‐1034, CC ST‐692, and CC ST‐1332 associated with ducks, and (iv) greater genetic diversity and genotype richness in ducks compared with starlings. These findings provide evidence that host‐associated genotypes, such as the starling‐associated ST‐177 and ST‐682, represent lineages that were introduced with the host species in the 19th century. The isolation of sequence types associated with human disease in New Zealand indicate that wild ducks and starlings need to be considered as a potential public health risk, particularly in urban areas.
Identification of a metagenomic gene cluster containing a new class A beta‐lactamase and toxin‐antitoxin systems
Authors: Vercammen Ken , Garcia‐Armisen Tamara , Goeders Nathalie , Van Melderen Laurence , Bodilis Josselin , Cornelis Pierre
Published: July 2013

Several reports mention the presence of antibiotic resistance genes in natural and polluted environments, but many studies are based on their detection via polymerase chain reaction (PCR amplification of known genes and not on an activity screening. We constructed a metagenomic fosmid bank from DNA isolated from a polluted river in Brussels, Belgium, the Zenne. A total of 120,000 clones were pooled and plated directly on solid media containing different antibiotics. Several clones were isolated which could grow in the presence of ampicillin. The DNA from several clones was extracted and subjected to restriction analysis and, based on their restriction pattern, two different clones were found. One of the clones was selected for further study as it showed a higher level of resistance to different β‐lactams antibiotics (ticarcilline and ceftazidime). To find out which gene is responsible for the resistance, an in vitro transposon mutagenesis was performed and clones having lost the resistance phenotype were analyzed via inverse PCR amplification. Several clones had an insert in a gene encoding a new type of β‐lactamase. The amplified fosmid DNA was fully sequenced revealing an insert of 41 kb containing 39 open reading frames (ORFs). Transposon insertions inactivating the resistance to β‐lactams were also found in the ORF upstream of the blaA gene, encoding an aminotransferase, suggesting a polar effect on the transcription of the gene downstream. In addition, other genes were found such as histidine biosynthesis genes, which were found to be scattered on the insert, a relA/spoT gene, and genes belonging to type II toxin–antitoxin system. This predicted system was experimentally validated in Escherichia coli using an inducible expression system.
Identification in Marinomonas mediterranea of a novel quinoprotein with glycine oxidase activity
Authors: Campillo‐Brocal Jonatan Cristian , Lucas‐Elio Patricia , Sanchez‐Amat Antonio
Published: July 2013

A novel enzyme with lysine‐epsilon oxidase activity was previously described in the marine bacterium Marinomonas mediterranea. This enzyme differs from other l‐amino acid oxidases in not being a flavoprotein but containing a quinone cofactor. It is encoded by an operon with two genes lodA and lodB. The first one codes for the oxidase, while the second one encodes a protein required for the expression of the former. Genome sequencing of M. mediterranea has revealed that it contains two additional operons encoding proteins with sequence similarity to LodA. In this study, it is shown that the product of one of such genes, Marme_1655, encodes a protein with glycine oxidase activity. This activity shows important differences in terms of substrate range and sensitivity to inhibitors to other glycine oxidases previously described which are flavoproteins synthesized by Bacillus. The results presented in this study indicate that the products of the genes with different degrees of similarity to lodA detected in bacterial genomes could constitute a reservoir of different oxidases.
Transcriptomic and phenotypic analysis of paralogous spx gene function in Bacillus anthracis Sterne
Authors: Barendt Skye , Lee Hyunwoo , Birch Cierra , Nakano Michiko M. , Jones Marcus , Zuber Peter
Published: July 2013

Spx of Bacillus subtilis is a redox‐sensitive protein, which, under disulfide stress, interacts with RNA polymerase to activate genes required for maintaining thiol homeostasis. Spx orthologs are highly conserved among low %GC Gram‐positive bacteria, and often exist in multiple paralogous forms. In this study, we used B. anthracis Sterne, which harbors two paralogous spx genes, spxA1 and spxA2, to examine the phenotypes of spx null mutations and to identify the genes regulated by each Spx paralog. Cells devoid of spxA1 were sensitive to diamide and hydrogen peroxide, while the spxA1 spoxA2 double mutant was hypersensitive to the thiol‐specific oxidant, diamide. Bacillus anthracis Sterne strains expressing spxA1DD or spxA2DD alleles encoding protease‐resistant products were used in microarray and quantitative real‐time polymerase chain reaction (RT‐qPCR) analyses in order to uncover genes under SpxA1, SpxA2, or SpxA1/SpxA2 control. Comparison of transcriptomes identified many genes that were upregulated when either SpxA1DD or SpxA2DD was produced, but several genes were uncovered whose transcript levels increased in only one of the two SpxADD‐expression strains, suggesting that each Spx paralog governs a unique regulon. Among genes that were upregulated were those encoding orthologs of proteins that are specifically involved in maintaining intracellular thiol homeostasis or alleviating oxidative stress. Some of these genes have important roles in B. anthracis pathogenesis, and a large number of upregulated hypothetical genes have no homology outside of the B. cereus/thuringiensis group. Microarray and RT‐qPCR analyses also unveiled a regulatory link that exists between the two spx paralogous genes. The data indicate that spxA1 and spxA2 are transcriptional regulators involved in relieving disulfide stress but also control a set of genes whose products function in other cellular processes.
Validation of quantitative bound‐ and pore‐water imaging in cortical bone
Authors: Manhard Mary Kate , Horch R. Adam , Harkins Kevin D. , Gochberg Daniel F. , Nyman Jeffry S. , Does Mark D.
Published: July 2013

Purpose

To implement and validate a previously proposed ultra‐short echo time method for measuring collagen‐bound‐ and pore‐water concentrations in bone based on their T2 differences.

Methods

Clinically compatible ultra‐short echo time image sequences for quantitative T2‐based bound and pore‐water imaging in bone were implemented and validated on a 3T human scanner and a 4.7T small bore system. Bound‐ and pore‐water images were generating using T2‐selective adiabatic pulses. In both cases, the magnetization preparation was integrated into a three‐dimensional ultra‐short echo time acquisition, with 16 radial spokes acquired per preparation. Images were acquired from human cadaveric femoral mid‐shafts from which isolated bone samples were subsequently extracted for nonimaging analysis using T2 spectroscopic measurements.

Results

A strong correlation was found between imaging‐derived concentrations of bound and pore water and those determined from the isolated bone samples.

Conclusions

These studies demonstrate the translation of the previously developed approaches for distinguishing bound and pore water from human cortical bone using practical human MRI constraints of gradient performance and radiofrequency power deposition. Magn Reson Med 71:2166–2171, 2014. © 2013 Wiley Periodicals, Inc.
Three‐dimensional Fourier encoding of simultaneously excited slices: Generalized acquisition and reconstruction framework
Authors: Zahneisen Benjamin , Poser Benedikt A. , Ernst Thomas , Stenger V. Andrew
Published: July 2013

Purpose

Simultaneous multislice (SMS) acquisitions have recently received much attention as a means of increasing single‐shot imaging speed. SMS acquisitions combine the advantages of single‐shot sampling and acceleration along the slice dimension which was previously limited to three‐dimensional (3D) volumetric acquisitions. A two‐dimensional description of SMS sampling and reconstruction has become established in the literature. Here, we present a more general 3D Fourier encoding and reconstruction formalism for SMS acquisitions that can easily be applied to non‐Cartesian SMS acquisitions.

Theory and Methods

An “SMS 3D” k‐space is defined in which the field of view along the slice select direction is equal to the number of excited slices times their separation. In this picture, SMS acceleration can be viewed as an undersampling of SMS 3D k‐space that can be freely distributed between the in‐plane and slice directions as both are effective phase‐encoding directions.

Results

Use of the SMS 3D k‐space picture is demonstrated in phantom and in vivo brain acquisitions including data obtained with blipped‐controlled aliasing in parallel imaging sampling. SMS sensitivity encoding reconstruction is demonstrated as well as non‐Cartesian SMS imaging using blipped spiral trajectories.

Conclusions

The full framework of reconstruction methods can be applied to SMS acquisitions by employing a 3D k‐space approach. The blipped‐controlled aliasing in parallel imaging method can be viewed as a special case of undersampling an SMS 3D k‐space. The extension of SMS methods to non‐Cartesian 3D sampling and reconstruction is straightforward. Magn Reson Med 71:2071–2081, 2014. © 2013 Wiley Periodicals, Inc.
RAZER: A pulse sequence for whole‐brain bolus tracking at high frame rates
Authors: Jonathan Sumeeth V. , Vakil Parmede , Jeong Yong I. , Menon Rajiv G. , Ansari Sameer A. , Carroll Timothy J.
Published: July 2013

Purpose

To introduce a pulse sequence that obtains whole‐brain perfusion measurements at 1.7 mm isotropic voxel resolution by dynamic susceptibility contrast MRI bolus tracking despite using a temporal resolution of 10.3 s: RAdial kZ‐blipped 3D GRE‐echo‐planar imaging (GRE‐EPI) for whole‐brain pERfusion (RAZER).

Methods

In RAZER, in‐plane radial and through‐plane 3D GRE‐EPI Cartesian sampling was used to produce a 3D stack‐of‐stars k‐space. In vivo scans on one healthy volunteer and one patient with Moyamoya disease were performed using RAZER and a typical 2D GRE‐EPI pulse sequence as a reference standard. Agreement in perfusion metrics was reported using linear regression analysis and Bland‐Altman plots.

Results

Sliding window reconstruction recovered dynamic information lost in the large temporal acquisition window of RAZER. Inline phase correction scans corrected N/2 ghosting artifacts and view‐dependent phase variations. Whole‐brain images of cerebral blood volume, cerebral blood flow, and mean transit time were calculated with RAZER at 1.7 mm isotropic voxel resolution and good reference standard agreement in both subjects when sliding window reconstruction was used (r2 > 0.7, mean bias in mean transit time measurements < 0.5 s).

Conclusions

Despite using a temporal resolution of 10.3 s, in vivo data indicates that RAZER is able to obtain whole‐brain perfusion measurements at 1.7 mm isotropic voxel resolution and good reference standard agreement. Magn Reson Med 71:2127–2138, 2014. © 2013 Wiley Periodicals, Inc.
Variational sensitivity analysis of a nonlinear solid shell element
Authors: Gerzen N. , Barthold F. J. , Klinkel S. , Wagner W. , Materna D.
Published: July 2013

The paper is concerned with variational sensitivity analysis of a nonlinear solid shell element, which is based on the Hu–Washizu variational principle. The sensitivity information is derived on the continuous level and discretized to yield the analytical expressions on the computational level. Especially, the pseudo load matrix and the sensitivity matrix, which dominate design sensitivity analysis of shape optimization problems, are derived. Because of the mixed formulation, condensation of the pseudo load matrix on the element level is performed to compute the sensitivity matrix. An illustrative example from the field of geometry‐based shape optimization demonstrates the possible application of the presented formulation. Copyright © 2013 John Wiley & Sons, Ltd.
Benzisoxazole 2‐oxides as novel UV absorbers and photooxidation inhibitors
Authors: Kociolek Martin George , Casbohm Jerry S.
Published: July 2013

Compounds with strong absorptions in the ultraviolet (UV) region of the spectrum, particularly the UVA and UVB, have seen much interest as UV screeners or absorbers in a wide variety of commercial products. A series of benzisoxazole 2‐oxides have been synthesized and characterized by UV–vis spectroscopy. A number of derivatives have been shown to posses moderate to strong molar absorption coefficients in the UVB range (ca. 300 nm), the strongest being those derived from benzophenones. Three other derivatives containing additional electron withdrawing groups showed strong molar absorption coefficients in the UVA (ca. 340 nm). Solvent effects on the parent derivatives show changes in the molar absorption coefficients with little changes in the λmax values. Preliminary studies of these compounds as potential additives to prevent photooxidation of polystyrene showed considerable inhibition of polymer degradation with the parent unsubstituted benzisoxazole 2‐oxide compounds being the most effective. Copyright © 2013 John Wiley & Sons, Ltd.
Is graphene on copper doped?
Authors: Marsden Alexander J. , Asensio Maria‐Carmen , Avila José , Dudin Pavel , Barinov Alexei , Moras Paolo , Sheverdyaeva Polina M. , White Thomas W. , Maskery Ian , Costantini Giovanni , Wilson Neil R. , Bell Gavin R.
Published: July 2013

Angle‐resolved photoemission spectroscopy (ARPES) and X‐ray photoemission spectroscopy have been used to characterise epitaxially ordered graphene grown on copper foil by low‐pressure chemical vapour deposition. A short vacuum anneal to 200 °C allows observation of ordered low energy electron diffraction patterns. High quality Dirac cones are measured in ARPES with the Dirac point at the Fermi level (undoped graphene). Annealing above 300 °C produces n‐type doping in the graphene with up to 350 meV shift in Fermi level, and opens a band gap of around 100 meV.

magnified image

Dirac cone dispersion for graphene on Cu foil after vacuum anneals (left: 200 °C, undoped; right: 500 °C, n‐doped). Centre: low energy electron diffraction from graphene on Cu foil after 200 °C anneal. Data from Antares (SOLEIL).

(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equivalent circuit model of a nanogenerator based on a piezoelectric nanowire–polymer composite
Authors: Graton Olivier , Poulin‐Vittrant Guylaine , Dahiya Abhishek Singh , Camara Nicolas , Hue Louis‐Pascal Tran Huu , Lethiecq Marc
Published: July 2013

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A vertically integrated nanogenerator (VING) refers to the new generation of mechanical energy harvesting devices: arrays of piezoelectric and semiconducting nanowires are grown perpendicularly to a substrate and appropriate electrodes enable charge circulation through an external electrical load. In this Letter, an equivalent circuit of VING is proposed. This model takes into account the effect of the polymer matrix that surrounds the nanowire lattice on the electromechanical behaviour of the generator. The active part of the material is then seen as a 1–3 piezocomposite. Simulations were made to study the VING performance in a context of body movement energy harvesting. In particular, it is shown that the strain amplitude and the strain rate of the piezocomposite have an impact on nanogenerator output voltage and output current, respectively. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)