bluuebunny/crossref_metadata_2025 huggingface dataset:
Spark-plasma-sintering magnetic field assisted compaction of Co80Ni20 nanowires for anisotropic ferromagnetic bulk materials
Authors: Ouar Nassima , Schoenstein Frédéric , Mercone Silvana , Farhat Samir , Villeroy Benjamin , Leridon Brigitte , Jouini Noureddine
Published: October 2013

We developed a two-step process showing the way for sintering anisotropic nanostructured bulk ferromagnetic materials. A new reactor has been optimized allowing the synthesis of several grams per batch of nanopowders via a polyol soft chemistry route. The feasibility of the scale-up has been successfully demonstrated for Co80Ni20 nanowires and a massic yield of ∼97% was obtained. The thus obtained nanowires show an average diameter of ∼6 nm and a length of ∼270 nm. A new bottom-up strategy allowed us to compact the powder into a bulk nanostructured system. We used a spark-plasma-sintering technique under uniaxial compression and low temperature assisted by a permanent magnetic field of 1 T. A macroscopic pellet of partially aligned nanowire arrays has been easily obtained. This showed optimized coercive properties along the direction of the magnetic field applied during compaction (i.e., the nanowires' direction).
The distorted K1 soft mode of hexagonal-BN sheet and effects of charge doping
Authors: Yang Wei , Yang Yu , Zheng Fawei , Zhang Ping
Published: October 2013

We demonstrate the distorted K1 soft mode for the phonon instability of single layer hexagonal-BN sheet under tension, which is different from the well known K1 mode failure mechanism of graphene. We also investigate the influences of charge doping on the soft mode phonon instability. Meanwhile, the ideal strength is found to be larger for both p- and n-type doped h-BN sheet, reflecting the electronic strengthening effect as similar as graphene. Our results reveal a different soft mode for h-BN sheet from that of graphene and can serve as references for future applications of h-BN sheet.
Modeling and optimization of ambipolar graphene transistors in the diffusive limit
Authors: Qian Qingkai , Liu Junku , Li Qunqing , Zou Yuan , Jin Yuanhao , Li Guanhong , Jiang Kaili , Fan Shoushan
Published: October 2013

We derived an analytical expression based on the Pao-Sah theory to characterize the electric conduction of ambipolar graphene transistors. We included and solved exactly the contact resistance, thermal excitation of carrier density, quantum capacitance, and the velocity saturation effect. Our model agreed with the experimental results for ion-gel gated graphene transistors. The microscopic conduction behavior was calculated and proved to be helpful for understanding the weak current saturation observed because of the “kink effect.” To achieve a high voltage gain for radio-frequency or analog circuit applications, the carrier velocity should be facilitated to reach saturation before the formation of the minimal carrier point inside the channel, which can be realized by decreasing the channel length and the series contact resistance. Given a finite channel length and the series contact resistance, the optimized gate capacitance can be solved analytically. Considering state-of-the-art device parameters, we find that maintaining a low contact resistance is vital for further improvement of the device performance.
Vertical correlation and miniband formation in submonolayer Zn(Cd)Te/ZnCdSe type-II quantum dots for intermediate band solar cell application
Authors: Dhomkar S. , Manna U. , Noyan I. C. , Tamargo M. C. , Kuskovsky I. L.
Published: October 2013

High resolution x-ray diffraction based reciprocal space mapping is employed to investigate vertical correlation in submonolayer Zn(Cd)Te/ZnCdSe type-II quantum dots (QDs). The average lateral deviation from one dot to another is found to decrease from 13%–17% to 8%–11% with an increase in QD size. Narrower photoluminescence with a better yield is obtained for the sample with improved vertical correlation, indicating smaller QD size distribution along with partial suppression of non-radiative recombination paths. Observed reduction in radiative lifetimes and supportive calculations demonstrate enhanced hole-hole wavefunction overlap pointing towards possibility of miniband formation, an advantageous feature for an intermediate band solar cell.
White light generation in Tm3+/Ho3+/Yb3+ doped PbO-GeO2 glasses excited at 980 nm
Authors: Camilo M. E. , Silva E. de O. , de Assumpção Thiago A. A. , Kassab Luciana R. P. , de Araújo Cid B.
Published: October 2013

We report white light generation (WLG) in Tm3+/Ho3+/Yb3+ doped PbO-GeO2 glass under continuous-wave excitation at 980 nm. Intense blue (≈477 nm), green (≈545 nm), and red (≈ 658 nm) emissions were simultaneously observed at room temperature. The blue light is mainly due to the Tm3+ transition 1G4 → 3H6. The green emission is due to the Ho3+ transitions (5S2, 5F4) → 5I8 and the red luminescence is due to the Ho3+ transition 5F5 → 5I8 and transition 1G4 → 3F4 associated to the Tm3+ ions. Energy transfer processes from Yb3+ to Ho3+ and Yb3+ to Tm3+ ions were responsible for the WLG. Adjusting the relative concentration of the rare-earth (RE) ions, we could obtain emission in the white region of the CIE chromaticity diagram. The present results indicate that PbO-GeO2 glass has large potential to be used for white displays.
Panther Politics: Neoliberalizing Nature in Southwest Florida
Authors: Schwartz Katrina Z S
Published: October 2013

The past quarter century has witnessed a ‘quieter revolution’ in land-use management in the United States, from top-down regulation and adversarial environmentalism to multistakeholder collaboration and voluntary market-based mechanisms designed to forge a compromise between nature protection, property rights, and local livelihoods. The latter approach has become hegemonic, and yet this dramatic shift has received little attention from political ecologists. In this paper I argue that two contradictory lessons on the topic can be drawn from political ecology. On the one hand, proponents of the ‘quieter revolution’ invoke themes and normative stances shared by political ecologists, celebrating self-management by place-based communities drawing on local knowledge, in opposition to control by central governments and powerful environmental groups wielding ‘big science’. On the other hand, the ‘quieter revolution’ exemplifies the neoliberalization of nature, which political ecologists have critiqued as providing a ‘stamp of environmental approval’ for capitalist expansion, often at the expense of the nature values it claims to defend. Thus, the ‘quieter revolution’ exposes tensions in the application of the Third-World-based political ecology orientation to a First World setting. I explore these tensions through a case study of voluntary and collaborative approaches (specifically, transfer of development rights and habitat conservation planning) in exurban Collier County in southwest Florida. I argue that in this context, it is more useful to focus on the neoliberalization of nature than on the valorization of local knowledge and control, because the discourse of local knowledge and livelihoods aligns with the (anti-environmental) interests of locally powerful actors. These power relations—and the limits of deeply embedded assumptions that undergird the political ecology literature—are revealed most effectively through ethnographic examination of the micropolitics of particular cases.
Back to the City: Internal Return Migration to Metropolitan Regions in Sweden
Authors: Amcoff Jan , Niedomysl Thomas
Published: October 2013

Longitudinal microdata on the Swedish population, 1990–2006, are used to examine the numbers and characteristics of internal return migrants, emphasizing Sweden's three largest cities. Our study indicates that metropolitan regions are gaining population from net return migration, which thus carries people in the same direction as does most internal migration. Evidence also indicates that returnees to metropolitan regions are more likely to stay permanently than are migrants returning elsewhere. Furthermore, return migrants to metropolitan regions are distinguished from other return migrants in ways that emphasize the advantages of these regions, higher incomes and levels of education being among the pronounced attributes. However, metro-bound returnees do not have as many children as do other return migrants.
The Ordinary City Trap
Authors: Smith Richard G
Published: October 2013

The paper is a critique of a critique; it explains why the most salient and influential critiques of the neo-Marxist world city and global city concepts, made by those arguing to further postcolonialize urban studies through such suppositions that all cities are ‘ordinary’, are misguided. First, it is explained how the charges of economism and ethnocentrism against the world city and global city concepts are ignoratio elenchi: They do not even begin to address or critique their neo-Marxist argument that, across the difference and diversity of the world's cities, a few major cities have the necessary economic specialization and therefore extraordinary function of commanding and controlling neoliberal globalization. Second, the error made by advocates of ordinary cities of supposing that world-systems analysis and the world city concept are forms of developmentalism is understood as the source for a wider postcolonial mistake of conflating the neo-Marxist world city and global city literatures with the very neoliberal practices toward urban development that they have long attempted to disclose and counter. Finally, the charges against the world city and global city concepts as paradigmatic, peripheralizing, and normative are also rebutted, not only to highlight how those critiques are consequentialist and dependent on the respective charges of economism, ethnocentrism, and developmentalism having veracity, but to demonstrate how an acceptance of the ordinary cities argument for an idiographic, provincial, nominalist, and comparative approach to urban studies, as an alternative to the two neo-Marxist concepts, is only to fall into the trap of making the mistake of confusing evidence of absence for absence of evidence.
Toward Empathic Agonism: Conflicting Vulnerabilities in Urban Wetland Governance
Authors: Horowitz Leah S
Published: October 2013

Critics of attempts to achieve consensus through Habermasian ‘communicative rationality’ dismiss this as unachievable due to participants' selfishness and irrationality, and the inevitability of power relations. Instead, Mouffe advocates ‘agonistic pluralism’, a dynamic process of continual debate grounded in mutual respect. In this paper I argue that, for this to succeed, we need to recognize and embrace the role of emotion in moral reasoning. Here, I examine a dispute over wetland management in suburban New Jersey. Each side articulated distinct understandings of what was and was not vulnerable, backed by emotional appeals partly based in self-interest but that also encompassed care and concern for others. Each side accused the other of being irrational and immoral, drawing ‘moral microboundaries’ between them. I conclude that participants in a public debate may not simply be pursing self-serving goals, nor might open communication resolve their differences. Instead, each may be deeply convinced that he or she is advocating the most rational and moral course of action. This questions the very notion of a unitary, potentially agreed-upon ‘common good’ and instead challenges us to attempt to grasp each other's moral worlds, and in particular the emotional bases of these, through the seeming oxymoron that I term ‘empathic agonism’.
Building a Municipal Food Policy Regime in Minneapolis: Implications for Urban Climate Governance
Authors: Shey Jane E , Belis David
Published: October 2013

With this paper we analyze Minneapolis's urban food policy regime and attempt to make a case for applying urban regime theory (URT) to study climate change governance at the municipal level. In 2008 Minneapolis launched Homegrown Minneapolis, a multiple stakeholder initiative bringing together local government actors, businesses, and NGOs to build a sustainable and local food system. As the link between food systems and climate change is increasingly acknowledged in the literature, the analysis of food policy regimes provides valuable lessons for understanding the dynamics of urban climate governance. Theoretically, we attempt to contribute to the fields of urban climate governance and urban political theory by applying URT as developed by urban political theorist Clarence N Stone and others. To this end, a ‘building blocks’ approach is introduced, facilitating and enhancing the analysis of the different elements of a regime, including initiation, coalition building, agenda setting, resources, cooperation, and consensus building. We show that there are several key elements comprising successful regimes: individual political leadership, knowledge exchange, and community-wide collaborative engagement.
Seasonality of foliar respiration in two dominant plant species from the Arctic tundra: response to long-term warming and short-term temperature variability
Authors: Heskel Mary A. , Bitterman Danielle , Atkin Owen K. , Turnbull Matthew H. , Griffin Kevin L.
Published: October 2013

Direct measurements of foliar carbon exchange through the growing season in Arctic species are limited, despite the need for accurate estimates of photosynthesis and respiration to characterise carbon cycling in the tundra. We examined seasonal variation in foliar photosynthesis and respiration (measured at 20°C) in two field-grown tundra species, Betula nana L. and Eriophorum vaginatum L., under ambient and long-term warming (LTW) conditions (+5°C), and the relationship of these fluxes to intraseasonal temperature variability. Species and seasonal timing drove most of the variation in photosynthetic parameters (e.g. gross photosynthesis (Agross)), respiration in the dark (Rdark) and light (Rlight), and foliar nitrogen concentration. LTW did not consistently influence fluxes through the season but reduced respiration in both species. Alongside the flatter respiratory response to measurement temperature in LTW leaves, this provided evidence of thermal acclimation. The inhibition of respiration by light increased by ~40%, with Rlight : Rdark values of ~0.8 at leaf out decreasing to ~0.4 after 8 weeks. Though LTW had no effect on inhibition, the cross-taxa seasonal decline in Rlight : Rdark greatly reduced respiratory carbon loss. Values of Rlight : Agross decreased from ~0.3 in both species to ~0.15 (B. nana) and ~0.05 (E. vaginatum), driven by decreases in respiratory rates, as photosynthetic rates remained stable. The influence of short-term temperature variability did not exhibit predictive trends for leaf gas exchange at a common temperature. These results underscore the influence of temperature on foliar carbon cycling, and the importance of respiration in controlling seasonal carbon exchange.
Interspecific variation in functional traits in relation to species climatic niche optima in Andean Polylepis (Rosaceae) tree species: evidence for climatic adaptations
Authors: Toivonen Johanna M. , Horna Viviana , Kessler Michael , Ruokolainen Kalle , Hertel Dietrich
Published: October 2013

Plant functional traits can be genetically determined or phenotypically plastic. We assessed the degree of genetic determinism in the functional traits of Andean Polylepis tree species among 14 important traits that enable the species to withstand cold and dry conditions. We conducted a common garden experiment and related the species-specific means of the functional traits to the variables of climatic niche optima of the species (mean annual temperature and annual precipitation), deducing that if the interspecific variation in the functional trait is related to the species climatic niche optima according to the theoretically-expected pattern of climate-trait relationship, the variation of the trait must be genetically determined. In general, the traits were related either to species temperature or precipitation optima. For example, leaf size, maximum photosynthesis rate and root tip abundance were related to temperature, whereas light compensation and light saturation points were related to precipitation. Only leaf size showed a significant phylogenetic signal, indicating that most of the manifested climate–trait relationships are not caused purely by phylogeny, but are mainly a result of species specialisation along an environmental gradient. However, in many cases the relationships were rather weak. This suggests that important functional traits of Polylepis species involve both genetic and phenotypic components aiming to maximise the overall fitness of the species at high elevations.
Targeted degradation of sense and antisense
C9orf72
RNA foci as therapy for ALS and frontotemporal degeneration
Authors: Lagier-Tourenne Clotilde , Baughn Michael , Rigo Frank , Sun Shuying , Liu Patrick , Li Hai-Ri , Jiang Jie , Watt Andrew T. , Chun Seung , Katz Melanie , Qiu Jinsong , Sun Ying , Ling Shuo-Chien , Zhu Qiang , Polymenidou Magdalini , Drenner Kevin , Artates Jonathan W. , McAlonis-Downes Melissa , Markmiller Sebastian , Hutt Kasey R. , Pizzo Donald P. , Cady Janet , Harms Matthew B. , Baloh Robert H. , Vandenberg Scott R. , Yeo Gene W. , Fu Xiang-Dong , Bennett C. Frank , Cleveland Don W. , Ravits John
Published: October 2013

Significance

The most frequent genetic cause of ALS and frontotemporal degeneration is a hexanucleotide expansion in a noncoding region of the
C9orf72
gene. Similar to other repeat expansion diseases, we characterize the hallmark feature of repeat expansion RNA-mediated toxicity: nuclear RNA foci. Remarkably, two distinct sets of foci are found, one containing RNAs transcribed in the sense direction and the other containing antisense RNAs. Antisense oligonucleotides (ASOs) are developed that selectively target sense strand repeat-containing RNAs and reduce sense-oriented foci without affecting overall
C9orf72
expression. Importantly, reducing
C9orf72
expression does not cause behavioral or pathological changes in mice and induces only a few genome-wide mRNA alterations. These findings establish ASO-mediated degradation of repeat-containing RNAs as a significant therapeutic approach.
Beyond intersubjectivity
Authors: Hauser Eric
Published: October 2013

One type of task interaction that students in a foreign language class may do is using the language they are studying for discussion. This paper analyzes interaction among Japanese university students participating in such discussions in English. The participants are interactionally competent; one source of resources they draw on to construct this competence is their first language, Japanese. Participants occasionally use Japanese to refer to Japanese things. They also use Japanese in the pursuit of intersubjectivity, such as using Japanese to solve a word search, with this being designed as a solution of last resort. Also, participants typically go beyond intersubjectivity as they translate Japanese into English. Word search design and going beyond intersubjectivity make visible participants’ task orientation to English as the proper language to use in these discussions. This task orientation provides a means for understanding the institutionality of the interaction.
“Children Are All Looking at You”
Authors: Moore Ekaterina
Published: October 2013

This discourse analysis of video-recorded data examines how through the use of directives Russian preschool teachers socialize three-year-old preschool newcomers into becoming competent members of their social setting. I demonstrate that this process involves manipulation of multiple semiotic resources, including language, body, physical objects, and orientation in physical space.
Previous research has shown that children “actively develop and use communicative skills to produce socially-ordered events in everyday interaction with adults and peers” (Corsaro 1979: 335). The present study demonstrates that adult care-givers take an active role in encouraging such production. During this process, the role of other children is highlighted, attention to ‘feelings of others’ is emphasized, and observation of each other’s behaviors is encouraged. ‘Others’ are ‘used’ to regulate the behavior, affective stances, and coordination of children’s actions.
Lights and shadows in creating a glossary about ontology engineering
Authors: Suárez-Figueroa Mari Carmen , Aguado-de-Cea Guadalupe , Gómez-Pérez Asunción
Published: October 2013

This paper addresses the lack of an explicitly agreed and defined terminology in the ontology engineering field, and particularly, the need for a glossary, which consists of terms and definitions for actions when developing ontologies. The novelty of this paper lies in the precise description of a methodology for building a glossary with the processes and activities involved in ontology development as well as the relations between them (such as subtype, composition and synonym). The methodology proposed in this paper takes its inspiration from ideas taken from earlier research on methodological processes for creating multilingual terminological products and for defining a glossary in a particular domain as well as on domain knowledge organization. The description of our methodology includes the approach followed and the steps carried out, as well as the key issues that arise when the glossary was being created. So far as we are aware, this is the first attempt to normalize the terminology (denominations and definitions) of process and activities in ontology building.
Methodological bases for assigning terminological equivalents
Authors: Pimentel Janine
Published: October 2013

This paper investigates the methodological bases for assigning terminological equivalents that have been proposed by lexicographers and terminologists. It will be argued that consistent methodologies for assigning equivalents are still lacking. We then describe a methodology based on Frame Semantics (Fillmore 1977, 1982, 1985; Fillmore and Atkins 1992) for assigning the equivalents of specialized verbs that occur in a comparable corpus of judgments and we provide arguments to the effect that a methodological approach to the establishment of terminological equivalence based on the frames evoked by the terms as well as on their syntagmatic behaviour is a suitable approach for the identification of equivalents. The resulting descriptions of the specialized verbs, of the frames and the identified equivalents were encoded in a resource called JuriDiCo from which examples will be drawn to illustrate our point.
Assessment for Possible Healthcare-Associated Transmission of a New Variant Influenza Virus—Pennsylvania, August 2011
Authors: Greenbaum Adena H. , Wong K. , Nguyen D. , Smith E. , Torso L. , Chen G. , Wise M. , Casey M. , Ostroff S. , Nambiar A. , Nalluswami K. , Miller J. , Lute J. , Klimov A. , Emery S. , Green M. , Giampa P. , Moll M. , Finelli L. , Jhung M.
Published: October 2013

In August 2011, one of the earliest cases of influenza A(H3N2) variant [A(H3N2)v] virus infection was hospitalized with severe illness. To investigate the potential for healthcare-associated transmission of influenza A(H3N2)v, we evaluated both healthcare providers and patient contacts of the case. We found that healthcare-associated transmission was unlikely.
Life as a professor at a small liberal arts college
Authors: Sandquist Josh , Romberg Laura , Yancey Paul
Published: October 2013

We present a look at what it is like to be a professor at a small college: one professor at Grinnell College, one at Oberlin College, and one at Whitman College.
Scientific approaches to science policy
Authors: Berg Jeremy M.
Published: October 2013

The development of robust science policy depends on use of the best available data, rigorous analysis, and inclusion of a wide range of input. While director of the National Institute of General Medical Sciences (NIGMS), I took advantage of available data and emerging tools to analyze training time distribution by new NIGMS grantees, the distribution of the number of publications as a function of total annual National Institutes of Health support per investigator, and the predictive value of peer-review scores on subsequent scientific productivity. Rigorous data analysis should be used to develop new reforms and initiatives that will help build a more sustainable American biomedical research enterprise.
Persistent telomere cohesion triggers a prolonged anaphase
Authors: Kim Mi Kyung , Smith Susan
Published: October 2013

Telomeres use distinct mechanisms (not used by arms or centromeres) to mediate cohesion between sister chromatids. However, the motivation for a specialized mechanism at telomeres is not well understood. Here we show, using fluorescence in situ hybridization and live-cell imaging, that persistent sister chromatid cohesion at telomeres triggers a prolonged anaphase in normal human cells and cancer cells. Excess cohesion at telomeres can be induced by inhibition of tankyrase 1, a poly(ADP-ribose) polymerase that is required for resolution of telomere cohesion, or by overexpression of proteins required to establish telomere cohesion, the shelterin subunit TIN2 and the cohesin subunit SA1. Regardless of the method of induction, excess cohesion at telomeres in mitosis prevents a robust and efficient anaphase. SA1- or TIN2-induced excess cohesion and anaphase delay can be rescued by overexpression of tankyrase 1. Moreover, we show that primary fibroblasts, which accumulate excess telomere cohesion at mitosis naturally during replicative aging, undergo a similar delay in anaphase progression that can also be rescued by overexpression of tankyrase 1. Our study demonstrates that there are opposing forces that regulate telomere cohesion. The observation that cells respond to unresolved telomere cohesion by delaying (but not completely disrupting) anaphase progression suggests a mechanism for tolerating excess cohesion and maintaining telomere integrity. This attempt to deal with telomere damage may be ultimately futile for aging fibroblasts but useful for cancer cells.
On tidal tilt corrections to large ring laser gyroscope observations
Authors: Tian Wei
Published: October 2013

With the fast development of the large ring laser gyroscope (RLG) technology in the last decades, promising applications in geophysics and geodesy (e.g. observations of high-frequency variations of Earth's rotation, Earth's tide tilt and seismic waves) have been realized by various groups with currently running large RLGs. In this letter, we point out that in a large number of previous tilt correction models a significant term is missing. This term is related with the Shida number l2 (called l2-term in the following) and has a contribution, which is comparable with that from high-frequency Earth rotation variations due to ocean tides, to the Sagnac frequency record of RLGs. This term has to be removed (as part of the tilt correction) from the raw data so that RLGs can efficiently be employed as Earth's rotation detectors.
Immune anticipation of mating in
Drosophila
:
Turandot M
promotes immunity against sexually transmitted fungal infections
Authors: Zhong Weihao , McClure Colin D. , Evans Cara R. , Mlynski David T. , Immonen Elina , Ritchie Michael G. , Priest Nicholas K.
Published: October 2013

Although it is well known that mating increases the risk of infection, we do not know how females mitigate the fitness costs of sexually transmitted infections (STIs). It has recently been shown that female fruitflies,
Drosophila melanogaster
, specifically upregulate two members of the
Turandot
family of immune and stress response genes,
Turandot M
and
Turandot C
(
TotM
and
TotC
), when they hear male courtship song. Here, we use the
Gal4/UAS
RNAi gene knockdown system to test whether the expression of these genes provides fitness benefits for females infected with the entomopathogenic fungus,
Metarhizium robertsii
under sexual transmission. As a control, we also examined the immunity conferred by
Dorsal-related immunity factor
(
Dif
), a central component of the
Toll
signalling pathway thought to provide immunity against fungal infections. We show that
TotM
, but not
TotC
or
Dif
, provides survival benefits to females following STIs, but not after direct topical infections. We also show that though the expression of
TotM
provides fecundity benefits for healthy females, it comes at a cost to their survival, which helps to explain why
TotM
is not constitutively expressed. Together, these results show that the anticipatory expression of
TotM
promotes specific immunity against fungal STIs and suggest that immune anticipation is more common than currently appreciated.
The ontogeny of home ranges: evidence from coral reef fishes
Authors: Welsh J. Q. , Goatley C. H. R. , Bellwood D. R.
Published: October 2013

The concept of home ranges is fundamental to ecology. Numerous studies have quantified how home ranges scale with body size across taxa. However, these relationships are not always applicable intraspecifically. Here, we describe how the home range of an important group of reef fish, the parrotfishes, scales with body mass. With masses spanning five orders of magnitude, from the early postsettlement stage through to adulthood, we find no evidence of a response to predation risk, dietary shifts or sex change on home range expansion rates. Instead, we document a distinct ontogenetic shift in home range expansion with sexual maturity. Juvenile parrotfishes displayed rapid home range growth until reaching approximately 100–150 mm length. Thereafter, the relationship between home range and mass broke down. This shift reflected changes in colour patterns, social status and reproductive behaviour associated with the transition to adult stages. While there is a clear relationship between body mass and home ranges among adult individuals of different species, it does not appear to be applicable to size changes within species. Ontogenetic changes in parrotfishes do not follow expected mass–area scaling relationships.
Did postglacial sea-level changes initiate the evolutionary divergence of a Tasmanian endemic raptor from its mainland relative?
Authors: Burridge C. P. , Brown W. E. , Wadley J. , Nankervis D. L. , Olivier L. , Gardner M. G. , Hull C. , Barbour R. , Austin J. J.
Published: October 2013

Populations on continental islands are often distinguishable from mainland conspecifics with respect to body size, appearance, behaviour or life history, and this is often congruent with genetic patterns. It is commonly assumed that such differences developed following the complete isolation of populations by sea-level rise following the Last Glacial Maximum (LGM). However, population divergence may predate the LGM, or marine dispersal and colonization of islands may have occurred more recently; in both cases, populations may have also diverged despite ongoing gene flow. Here, we test these alternative hypotheses for the divergence between wedge-tailed eagles from mainland Australia (Aquila audax audax) and the threatened Tasmanian subspecies (Aquila audax fleayi), based on variation at 20 microsatellite loci and mtDNA. Coalescent analyses indicate that population divergence appreciably postdates the severance of terrestrial habitat continuity and occurred without any subsequent gene flow. We infer a recent colonization of Tasmania by marine dispersal and cannot discount founder effects as the cause of differences in body size and life history. We call into question the general assumption of post-LGM marine transgression as the initiator of divergence of terrestrial lineages on continental islands and adjacent mainland, and highlight the range of alternative scenarios that should be considered.
Luteimonas abyssi sp. nov., isolated from deep-sea sediment
Authors: Fan Xiaoyang , Yu Tong , Li Zhao , Zhang Xiao-Hua
Published: October 2013

Three Gram-stain-negative, strictly aerobic, rod-shaped with single polar flagellum, yellow-pigmented bacteria, designated strains XH031T, XH038-3 and XH80-1, were isolated from deep-sea sediment of the South Pacific Gyre (41° 51′ S 153° 6′ W) during the Integrated Ocean Drilling Program (IODP) Expedition 329. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates belonged to the genus

Luteimonas

and showed the highest 16S rRNA gene sequence similarity with

Luteimonas aestuarii

B9T (96.95 %),

Luteimonas huabeiensis

HB2T (96.93 %) and

Xanthomonas cucurbitae

LMG 690T (96.92 %). The DNA G+C contents of the three isolates were 70.2–73.9 mol%. The major fatty acids were iso-C15 : 0, iso-C16 : 0, iso-C11 : 0 and C16 : 010-methyl and/or iso-C17 : 1ω9c. The major respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unknown phospholipid. On the basis of data from polyphasic analysis, the three isolates represent a novel species of the genus

Luteimonas

, for which the name

Luteimonas

abyssi sp. nov. is proposed. The type strain is XH031T ( = DSM 25880T = CGMCC 1.12611T).
Structure and Function of Nucleoside Hydrolases from Physcomitrella patens and Maize Catalyzing the Hydrolysis of Purine, Pyrimidine, and Cytokinin Ribosides
Authors: Kopečná Martina , Blaschke Hanna , Kopečný David , Vigouroux Armelle , Končitíková Radka , Novák Ondřej , Kotland Ondřej , Strnad Miroslav , Moréra Solange , von Schwartzenberg Klaus
Published: October 2013

We present a comprehensive characterization of the nucleoside N-ribohydrolase (NRH) family in two model plants, Physcomitrella patens (PpNRH) and maize (Zea mays; ZmNRH), using in vitro and in planta approaches. We identified two NRH subclasses in the plant kingdom; one preferentially targets the purine ribosides inosine and xanthosine, while the other is more active toward uridine and xanthosine. Both subclasses can hydrolyze plant hormones such as cytokinin ribosides. We also solved the crystal structures of two purine NRHs, PpNRH1 and ZmNRH3. Structural analyses, site-directed mutagenesis experiments, and phylogenetic studies were conducted to identify the residues responsible for the observed differences in substrate specificity between the NRH isoforms. The presence of a tyrosine at position 249 (PpNRH1 numbering) confers high hydrolase activity for purine ribosides, while an aspartate residue in this position confers high activity for uridine. Bud formation is delayed by knocking out single NRH genes in P.  patens, and under conditions of nitrogen shortage, PpNRH1-deficient plants cannot salvage adenosine-bound nitrogen. All PpNRH knockout plants display elevated levels of certain purine and pyrimidine ribosides and cytokinins that reflect the substrate preferences of the knocked out enzymes. NRH enzymes thus have functions in cytokinin conversion and activation as well as in purine and pyrimidine metabolism.
Essential Role of the E3 Ubiquitin Ligase NOPPERABO1 in Schizogenous Intercellular Space Formation in the Liverwort Marchantia polymorpha
Authors: Ishizaki Kimitsune , Mizutani Miya , Shimamura Masaki , Masuda Akihide , Nishihama Ryuichi , Kohchi Takayuki
Published: October 2013

The vast majority of land plants develop gas-exchange tissues with intercellular spaces (ICSs) connected directly to the air. Although the developmental processes of ICS have been described in detail at the morphological and ultrastructural level in diverse land plants, little is known about the molecular mechanism responsible for ICS formation. The liverwort Marchantia polymorpha develops a multilayered tissue with a large ICS (air chamber), whose formation is initiated at selected positions of epidermal cells. We isolated a mutant of M. polymorpha showing impaired air-chamber formation, nopperabo1 (nop1), from T-DNA–tagged lines. In nop1 plants, no ICS was formed; consequently, a single-layered epidermis developed on the dorsal side of the thallus. The causal gene NOP1 encodes a Plant U-box (PUB) E3 ubiquitin ligase carrying tandem ARMADILLO (ARM) repeats in the C terminus. An in vitro ubiquitination assay indicated that the NOP1 protein possesses E3 ubiquitin ligase activity in a U-box–dependent manner. Confocal microscopy and biochemical analysis showed that NOP1 was localized to the plasma membrane. Our investigation demonstrated the essential role of the PUB-ARM–type ubiquitin ligase in ICS formation in M. polymorpha, which sheds light on the molecular mechanism of schizogenous ICS formation in land plants.
Variation in floral morphology within a population of Aster hispidus var. tubulosus (Asteraceae, Astereae)
Authors: Nakagawa Sayaka , Ito Motomi
Published: October 2013

The family Asteraceae has a particular inflorescence, the capitulum, consisting of ray florets and disc florets. The ray florets function as petals that attract pollinators. Marked variation in the ray floret morphology is known in a natural population of Aster hispidus var. tubulosus (Asteraceae). We analyzed the variation and found two distinct types in the ray florets, the long tubular ray floret and the ligulate ray floret. In this species, therefore, the variation in floral morphology among capitula, each of which is the basic pollination unit, is caused by the variation in the composition of the two ray floret types among capitula. We evaluated the sources of the observed variation in the floral morphology among capitula within a population using a hierarchical analysis that separated within‐individual (i.e. among capitula within each individual) and between‐individual components of the variation. We found that the main source of the variation lay at the between‐individual level, not at the between‐capitulum level nested within individuals. This finding will provide the basic knowledge that enables future study exploring whether the between‐individual variation in floral morphology caused by the compositional variation of the ray floret types leads to differential pollination success of individual plants in species of Asteraceae.
Family transitions and changes in drinking from adolescence through mid‐life
Authors: Staff Jeremy , Greene Kaylin M. , Maggs Jennifer L. , Schoon Ingrid
Published: October 2013

Aims

To examine how changes in social roles, particularly in the family, predict rises and falls in alcohol consumption from ages 16 to 50 years.

Design

Longitudinal data from the National Child Development Study.

Setting

The birth cohort includes 99% of British infants born in 1 week in 1958.

Participants

After initial assessment of 17 415 infants, the cohort was interviewed at ages 7, 11, 16, 23, 33, 42, 46, and 50. This study uses the six adolescent to adult waves (n = 7212 women, 7377 men).

Measurements

Alcohol use [i.e. quantity consumed in past week and heavy‐daily drinking), symptoms of problem drinking (i.e. Cut‐down, Annoyed, Guilt, Eye‐opener (CAGE)] and social roles (i.e. union formation, parenthood and employment).

Findings

Estimates from fixed‐effects models demonstrate that alcohol use is lower when women reside with child(ren) under age 5, compared to occasions when they do not [estimate = −0.38, 95% confidence interval (CI) = −0.43, −0.32 for past week units; odds ratio (OR) = 0.47, CI = 0.36, 0.62 for heavy‐daily drinking; OR = 0.66, CI = 0.50, 0.87 for CAGE symptoms]. Associations are similar for men (estimate = −0.29, CI = −0.36, −0.23; OR = 0.64, CI = 0.53, 0.77; OR = 0.69, CI = 0.51, 0.94, respectively). When women and men are married, working and residing with young child(ren), past week units (estimate = −0.51, CI = −0.61, −0.41 for women; estimate = −0.34, CI = −0.44, −0.25 for men), heavy‐daily drinking (OR = 0.49, CI = 0.30, 0.79 for women; OR = 0.47, CI = 0.35, 0.64 for men) and CAGE (OR = 0.44, CI = 0.23, 0.83 for women; OR = 0.39, CI = 0.18, 0.82 for men) are lower compared to occasions when they are not in these roles.

Conclusions

From late adolescence to mid‐life, women and men in Britain are most at risk for higher levels of alcohol consumption and problem drinking when family roles are absent.
Adjusting to chronic illness: Time for a unified theory
Authors: Moss‐Morris Rona
Published: October 2013

Statement of contribution

What is already known?

Adapting to chronic illness is a phrase commonly used in health psychology.

Common operationalizations include presence or absence of psychopathology, or low negative affect and good functional status.

A variety of models are currently used to study adaptation to chronic illness. Each explain some variance in adjustment outcomes.

What does this editorial add?

An argument for a consistent overarching theory that is specific to the process of adaptation to chronic illness.

Adaptation is characterized as a return to equilibrium after critical illness events or stressors.

A new working model of adapting to chronic illness.
The impact of diagnosis and trait anxiety on psychological distress in women with early stage breast cancer: A prospective study
Authors: Keyzer‐Dekker Claudia M. G. , de Vries Jolanda , Mertens Marlies C. , Roukema Jan A. , van der Steeg Alida F. W.
Published: October 2013

Objectives

High trait anxiety (HTA) determines depressive symptoms and state anxiety in women with breast cancer (BC) or benign breast disease (BBD). Before implementing screening for psychological counselling in these women, it is important to evaluate whether high state anxiety and depressive symptoms are determined by (the threat of) having BC or solely by HTA. Therefore, we compared women with a lump in the breast with women with gallstone disease (GD).

Methods

Women diagnosed with BC (n = 152), BBD (n = 205), and GD (n = 128) were included in a prospective longitudinal study. Questionnaires concerning trait anxiety (baseline), state anxiety, and depressive symptoms were completed before diagnosis was known (BC and BBD) or the laparoscopic cholecystectomy and 6 months later.

Results

Pre‐diagnosis BC patients scored higher on state anxiety (p = .001) and depressive symptoms (p < .001) compared with GD. At 6 months, scores on depressive symptoms in BC remained higher than GD (p = .005). In women with HTA, before being diagnosed with BC or BBD, scores on state anxiety were higher compared with HTA women with GD (p < .001, p = .040). State anxiety and depressive symptoms at 6 months were predicted by baseline depressive symptoms in women with BC.

Conclusions

The severity of diagnosis (BC) in combination with HTA determined the level of state anxiety and depressive symptoms. Therefore, we recommend identifying women with HTA and offering them a tailor‐made follow‐up protocol during and after the diagnostic process for BBD or BC.

Statement of contribution

What is already known on this subject? Women diagnosed with BC or BBD experience high levels of anxiety and distress during the diagnostic process. These adverse psychological effects are strengthened by the personality characteristic trait anxiety. Before implementing screening for psychological counselling in women with high trait anixety, it is important to evaluate whether high state anxiety and depressive symptoms are determined by (the threat of) having BC or solely by HTA.

What does this study add? To our knowledge, this is the first study comparing women who are confronted with the possibility of having a life‐threatening disease, that is, BC, with women who were not suspected of having a life‐threatening disease, that is, GD. This study reveals that the severity of diagnosis (BC) in combination with HTA determined the level of state anxiety and depressive symptoms. Therefore, we recommend identifying women with HTA and offering them a tailor‐made follow‐up protocol during and after the diagnostic process for BC or BBD.
Thromboxane receptor hyper‐responsiveness in hypoxic pulmonary hypertension requires serine 324
Authors: Santhosh K T , Sikarwar A S , Hinton M , Chelikani P , Dakshinamurti S
Published: October 2013

Background and Purpose

Dysregulation of the thromboxane A2 (TP) receptor, resulting in agonist hypersensitivity and hyper‐responsiveness, contributes to exaggerated vasoconstriction in the hypoxic pulmonary artery in neonatal persistent pulmonary hypertension. We previously reported that hypoxia inhibits TP receptor phosphorylation, causing desensitization. Hence, we examined the role of PKA‐accessible serine residues in determining TP receptor affinity, using site‐directed mutational analysis.

Experimental Approach

Vasoconstriction to a thromboxane mimetic and phosphorylation of TP receptor serine was examined in pulmonary arteries from neonatal swine with persistent pulmonary hypertension and controls. Effects of hypoxia were determined in porcine and human TP receptors. Human TPα serines at positions 324, 329 and 331 (C‐terminal tail) were mutated to alanine and transiently expressed in HEK293T cells. Saturation binding and displacement kinetics of a TP antagonist and agonist were determined in porcine TP, wild‐type human TPα and all TP mutants. Agonist‐elicited calcium mobilization was determined for each TP mutant, in the presence of a PKA activator or inhibitor, and in hypoxic and normoxic conditions.

Key Results

The Ser324A mutant was insensitive to PKA activation and hypoxia, had a high affinity for agonist and increased agonist‐induced calcium mobilization. Ser329A was no different from wild‐type TP receptors. Ser331A was insensitive to hypoxia and PKA with a decreased agonist‐mediated response.

Conclusions and Implications

In hypoxic pulmonary hypertension, loss of site‐specific phosphorylation of the TP receptor causes agonist hyper‐responsiveness. Ser324 is the primary residue phosphorylated by PKA, which regulates TP receptor‐agonist interactions. Ser331 mutation confers loss of TP receptor‐agonist interaction, regardless of PKA activity.
Cell‐specific blood–brain barrier regulation in health and disease: a focus on hypoxia
Authors: Engelhardt S , Patkar S , Ogunshola O O
Published: October 2013

The blood–brain barrier (BBB) is a complex vascular structure consisting of microvascular endothelial cells that line the vessel wall, astrocyte end‐feet, pericytes, as well as the basal lamina. BBB cells act in concert to maintain the characteristic impermeable and low paracellular flux of the brain vascular network, thus ensuring a homeostatic neuronal environment. Alterations in BBB stability that occur during injury have dire consequences on disease progression and it is clear that BBB cell‐specific responses, positive or negative, must make a significant contribution to injury outcome. Reduced oxygenation, or hypoxia, is a characteristic of many brain diseases that significantly increases barrier permeability. Recent data suggest that hypoxia‐inducible factor (HIF‐1), the master regulator of the hypoxic response, probably mediates many hypoxic effects either directly or indirectly via its target genes. This review discusses current knowledge of physiological cell‐specific regulation of barrier function, their responses to hypoxia as well as consequences of hypoxic‐ and HIF‐1‐mediated mechanisms on barrier integrity during select brain diseases. In the final sections, the potential of current advances in targeting HIF‐1 as a therapeutic strategy will be overviewed.