bluuebunny/crossref_metadata_2025 huggingface dataset:
The problem of hole localization in inner-shell states of N2 and CO2 revisited with complete active space self-consistent field approach
Authors: Rocha Alexandre B. , de Moura Carlos E. V.
Published: December 2011

Potential energy curves for inner-shell states of nitrogen and carbon dioxide molecules are calculated by inner-shell complete active space self-consistent field (CASSCF) method, which is a protocol, recently proposed, to obtain specifically converged inner-shell states at multiconfigurational level. This is possible since the collapse of the wave function to a low-lying state is avoided by a sequence of constrained optimization in the orbital mixing step. The problem of localization of K-shell states is revisited by calculating their energies at CASSCF level based on both localized and delocalized orbitals. The localized basis presents the best results at this level of calculation. Transition energies are also calculated by perturbation theory, by taking the above mentioned MCSCF function as zeroth order wave function. Values for transition energy are in fairly good agreement with experimental ones. Bond dissociation energies for N2 are considerably high, which means that these states are strongly bound. Potential curves along ground state normal modes of CO2 indicate the occurrence of Renner-Teller effect in inner-shell states.
Study of ohmic contacts to n-type Ge: Snowplow and laser activation
Authors: Firrincieli A. , Martens K. , Rooyackers R. , Vincent B. , Rosseel E. , Simoen E. , Geypen J. , Bender H. , Claeys C. , Kittl J. A.
Published: December 2011

Typical contacts to n-Ge result in high specific contact resistivity (ρC) or rectifying behaviour due to Fermi level pinning (resulting in high barrier heights) and low dopant activation generally observed for n-Ge. In this work, we fabricated and studied ohmic contacts to n-type Ge prepared by Ni germanidation of samples with As ion implantation for two different approaches: (1) dopant activation by sub-melt laser anneal (LA) prior to germanidation and (2) Snowplow, i.e., dopant segregation during Ni germanidation without previous thermal activation. Low resistivity ohmic contacts of 8 × 10−7 Ω cm2 for LA and 2 × 10−5 Ω cm2 for Snowplow were obtained using circular transfer length method to determine ρC. We show contacts to be thermally stable to 350 °C. Furthermore, by studying the temperature dependence of ρC, we clarify that the underlying cause of the low contact resistivity for both approaches is the high active dopant concentration obtained. We find the results in both cases to be consistent with the thermionic field-emission mechanism for a barrier height of 0.75 eV and with active dopant concentrations of 3 × 1019 cm−3 for LA and 1.5 × 1019 cm−3 for Snowplow samples.
Polariton enhanced infrared reflection of epitaxial graphene
Authors: Daas B. K. , Daniels K. M. , Sudarshan T. S. , Chandrashekhar M. V. S.
Published: December 2011

We show SiC substrate phonon-induced surface plasmon polariton (SPP) formation in epitaxial graphene grown on 4H–SiC, in SiC’s restrahlen band (8–10 μm). By fitting measurement to theory, we extract thickness, momentum scattering time (τ), sheet carrier density (ns), and estimate carrier mobility. By showing that τ∝1ns, we argue that scattering is dominated by short-range interactions at the SiC/graphene interface. SPP formation finds application in nanophotonic devices for optical computing because of graphene’s unique plasmonic properties.
Limited-view photoacoustic tomography utilizing backscatterers as virtual transducers
Authors: Wu D. , Wang X. , Tao C. , Liu X. J.
Published: December 2011

In photoacoustic tomography, acoustic scattering is usually considered as a nuisance, because it distorts an incident wavefront and then induces artifacts and distortion. This work demonstrates that backscatterers could function as virtual transducers arranged behind the region of interest and are used to improve limited-view reconstruction. This idea is confirmed by both simulations and experiments. Our results suggest that enhanced photoacoustic tomography could be obtained by taking advantage of native scatterers in tissues or artificial ones injected around the region of interest.
Resonant enhancement of magneto-optical polarization conversion in microdisk resonators
Authors: Deych Lev , Meriles Carlos , Menon Vinod
Published: December 2011

We theoretically investigate the effect of a periodically modulated magnetic field on the polarization properties of whispering-gallery-modes (WGM) in microdisk resonators. We show that by matching the modulation frequency to the frequency offset between WGMs with two mutually perpendicular polarizations one can achieve an enhancement of the magneto-optical polarization effect by a factor of M1/3QM(av), where M is the modal order of the WGM and QM(av) is the geometric average of the quality factors of the TE and TM polarized modes.
The Completeness and Reliability of Threshold and False-discovery Rate Source Extraction Algorithms for Compact Continuum Sources
Authors: Huynh M. T. , Hopkins A. , Norris R. , Hancock P. , Murphy T. , Jurek R. , Whiting M.
Published: December 2011

The process of determining the number and characteristics of sources in astronomical images is so fundamental to a large range of astronomical problems that it is perhaps surprising that no standard procedure has ever been defined that has well-understood properties with a high degree of statistical rigour on completeness and reliability. The Evolutionary Map of the Universe (EMU) survey with the Australian Square Kilometre Array Pathfinder (ASKAP), a continuum survey of the Southern Hemisphere up to declination +30°, aims to utilise an automated source identification and measurement approach that is demonstrably optimal, to maximise the reliability, utility and robustness of the resulting radio source catalogues. A key stage in source extraction methods is the background estimation (background level and noise level) and the choice of a threshold high enough to reject false sources, yet not so high that the catalogues are significantly incomplete. In this analysis, we present results from testing the SExtractor, Selavy (Duchamp), and SFIND source extraction tools on simulated data. In particular, the effects of background estimation, threshold and false-discovery rate settings are explored. For parameters that give similar completeness, we find the false-discovery rate method employed by SFIND results in a more reliable catalogue compared to the peak threshold methods of SExtractor and Selavy.
Localised spawning omission in snapper, Chrysophrys auratus (Sparidae)
Authors: Sim-Smith Carina J. , Jeffs Andrew G. , Radford Craig A.
Published: December 2011

Failure to spawn in a significant proportion of adult fish may greatly decrease the reproductive output of a population and lead to overestimates of recruitment to the fish stock. Reproductive output of the commercially important sparid, Chrysophrys auratus, around the Kaipara Harbour, New Zealand, is particularly important as this harbour is the primary source for the C. auratus population along the west coast of the North Island of New Zealand. We tested the hypothesis that C. auratus do not spawn inside the Kaipara Harbour by comparing monthly gonad and otolith samples from fish caught within the harbour with those of fish from surrounding coastal waters. Fish from coastal waters showed normal gonad development with peak spawning in spring. By comparison, almost all adult fish from the harbour had underdeveloped gonads, with mean gonadosomatic indices ≤1. Histological gonad analyses of C. auratus caught in the harbour showed vitellogenic oocytes were reabsorbed before spawning. Therefore, recruitment to the harbour must originate from spawning that occurs outside the harbour. This first record of spawning omission in C. auratus has important implications for fisheries management, as it may lead to overestimation of the spawning stock and increase the risk of broad-scale population depletion, through the targeted fishing of spawning aggregations.
The mirror game as a paradigm for studying the dynamics of two people improvising motion together
Authors: Noy Lior , Dekel Erez , Alon Uri
Published: December 2011

Joint improvisation is the creative action of two or more people without a script or designated leader. Examples include improvisational theater and music, and day-to-day activities such as conversations. In joint improvisation, novel action is created, emerging from the interaction between people. Although central to creative processes and social interaction, joint improvisation remains largely unexplored due to the lack of experimental paradigms. Here we introduce a paradigm based on a theater practice called the mirror game. We measured the hand motions of two people mirroring each other at high temporal and spatial resolution. We focused on expert actors and musicians skilled in joint improvisation. We found that players can jointly create novel complex motion without a designated leader, synchronized to less than 40 ms. In contrast, we found that designating one player as leader deteriorated performance: The follower showed 2–3 Hz oscillation around the leader's smooth trajectory, decreasing synchrony and reducing the range of velocities reached. A mathematical model suggests a mechanism for these observations based on mutual agreement on future motion in mirrored reactive–predictive controllers. This is a step toward understanding the human ability to create novelty by improvising together.
Imaging dynamic insulin release using a fluorescent zinc indicator for monitoring induced exocytotic release (ZIMIR)
Authors: Li Daliang , Chen Shiuhwei , Bellomo Elisa A. , Tarasov Andrei I. , Kaut Callan , Rutter Guy A. , Li Wen-hong
Published: December 2011

Current methods of monitoring insulin secretion lack the required spatial and temporal resolution to adequately map the dynamics of exocytosis of native insulin granules in intact cell populations in three dimensions. Exploiting the fact that insulin granules contain a high level of Zn
2+
, and that Zn
2+
is coreleased with insulin during secretion, we have developed a fluorescent, cell surface-targeted zinc indicator for monitoring induced exocytotic release (ZIMIR). ZIMIR displayed a robust fluorescence enhancement on Zn
2+
chelation and bound Zn
2+
with high selectivity against Ca
2+
and Mg
2+
. When added to cultured β cells or intact pancreatic islets at low micromolar concentrations, ZIMIR labeled cells rapidly, noninvasively, and stably, and it reliably reported changes in Zn
2+
concentration near the sites of granule fusion with high sensitivity that correlated well with membrane capacitance measurement. Fluorescence imaging of ZIMIR-labeled β cells followed the dynamics of exocytotic activity at subcellular resolution, even when using simple epifluorescence microscopy, and located the chief sites of insulin release to intercellular junctions. Moreover, ZIMIR imaging of intact rat islets revealed that Zn
2+
/insulin release occurred largely in small groups of adjacent β cells, with each forming a “secretory unit.” Concurrent imaging of ZIMIR and Fura-2 showed that the amplitude of cytosolic Ca
2+
elevation did not necessarily correlate with insulin secretion activity, suggesting that events downstream of Ca
2+
signaling underlie the cell-cell heterogeneity in insulin release. In addition to studying stimulation-secretion coupling in cells with Zn
2+
-containing granules, ZIMIR may find applications in β-cell engineering and screening for molecules regulating insulin secretion on high-throughput platforms.
Whole-body deletion of LPS-induced TNF-α factor (LITAF) markedly improves experimental endotoxic shock and inflammatory arthritis
Authors: Merrill Jamie C. , You Jian , Constable Cara , Leeman Susan E. , Amar Salomon
Published: December 2011

LPS-induced TNF-α factor (LITAF) mediates cytokine expression in response to endotoxin challenge. Previously, we reported that macrophage-specific LITAF-deficient (macLITAF−/−) mice exposed to LPS have a delayed onset in the serum levels of proinflammatory cytokines and prolonged persistence of anti-inflammatory cytokines, but only partial protection from endotoxic shock. We postulated that greater protection might be achieved if LITAF were deleted from all LITAF-producing cells, including macrophages. Using a Cre-loxP system, we engineered a tamoxifen-induced recombination mouse [tamLITAF(i)−/−] that resulted in whole-body LITAF deficiency. Our findings demonstrate that (i) tamLITAF(i)−/−mice are more resistant to systemicEscherichia coliLPS-induced lethality than our previous macLITAF−/−mice, providing evidence that LITAF-producing cells other than LysMCre-positive cells play an important role in mediating endotoxic shock; (ii) tamLITAF(i)−/−mice show a similar pattern of cytokine expression with decreased proinflammatory and prolonged anti-inflammatory mediators compared with WT mice; and (iii) tamLITAF(i)−/−mice, compared with WT mice, display a significant reduction in bone resorption and inflammation associated with a local chronic inflammatory disease—namely, collagen antibody-induced arthritis. Our findings offer a unique model to study the role of LITAF in systemic and chronic local inflammatory processes, and pave the way for anti-LITAF therapeutic approaches for the treatment of TNF-mediated inflammatory diseases.
Cumulative impacts of mountaintop mining on an Appalachian watershed
Authors: Lindberg T. Ty , Bernhardt Emily S. , Bier Raven , Helton A. M. , Merola R. Brittany , Vengosh Avner , Di Giulio Richard T.
Published: December 2011

Mountaintop mining is the dominant form of coal mining and the largest driver of land cover change in the central Appalachians. The waste rock from these surface mines is disposed of in the adjacent river valleys, leading to a burial of headwater streams and dramatic increases in salinity and trace metal concentrations immediately downstream. In this synoptic study we document the cumulative impact of more than 100 mining discharge outlets and approximately 28 km
2
of active and reclaimed surface coal mines on the Upper Mud River of West Virginia. We measured the concentrations of major and trace elements within the tributaries and the mainstem and found that upstream of the mines water quality was equivalent to state reference sites. However, as eight separate mining-impacted tributaries contributed their flow, conductivity and the concentrations of selenium, sulfate, magnesium, and other inorganic solutes increased at a rate directly proportional to the upstream areal extent of mining. We found strong linear correlations between the concentrations of these contaminants in the river and the proportion of the contributing watershed in surface mines. All tributaries draining mountaintop-mining-impacted catchments were characterized by high conductivity and increased sulfate concentration, while concentrations of some solutes such as Se, Sr, and N were lower in the two tributaries draining reclaimed mines. Our results demonstrate the cumulative impact of multiple mines within a single catchment and provide evidence that mines reclaimed nearly two decades ago continue to contribute significantly to water quality degradation within this watershed.
Neurite outgrowth inhibitor Nogo-A establishes spatial segregation and extent of oligodendrocyte myelination
Authors: Chong S. Y. Christin , Rosenberg Sheila S. , Fancy Stephen P. J. , Zhao Chao , Shen Yun-An A. , Hahn Angela T. , McGee Aaron W. , Xu Xiaomei , Zheng Binhai , Zhang Li I. , Rowitch David H. , Franklin Robin J. M. , Lu Q. Richard , Chan Jonah R.
Published: December 2011

A requisite component of nervous system development is the achievement of cellular recognition and spatial segregation through competition-based refinement mechanisms. Competition for available axon space by myelinating oligodendrocytes ensures that all relevant CNS axons are myelinated properly. To ascertain the nature of this competition, we generated a transgenic mouse with sparsely labeled oligodendrocytes and establish that individual oligodendrocytes occupying similar axon tracts can greatly vary the number and lengths of their myelin internodes. Here we show that intercellular interactions between competing oligodendroglia influence the number and length of myelin internodes, referred to as myelinogenic potential, and identify the amino-terminal region of Nogo-A, expressed by oligodendroglia, as necessary and sufficient to inhibit this process. Exuberant and expansive myelination/remyelination is detected in the absence of Nogo during development and after demyelination, suggesting that spatial segregation and myelin extent is limited by microenvironmental inhibition. We demonstrate a unique physiological role for Nogo-A in the precise myelination of the developing CNS. Maximizing the myelinogenic potential of oligodendrocytes may offer an effective strategy for repair in future therapies for demyelination.
Low-affinity cation transporter (
OsLCT1
) regulates cadmium transport into rice grains
Authors: Uraguchi Shimpei , Kamiya Takehiro , Sakamoto Takuya , Kasai Koji , Sato Yutaka , Nagamura Yoshiaki , Yoshida Akiko , Kyozuka Junko , Ishikawa Satoru , Fujiwara Toru
Published: December 2011

Accumulation of cadmium (Cd) in rice (
Oryza sativa
L.) grains poses a potential health problem, especially in Asia. Most Cd in rice grains accumulates through phloem transport, but the molecular mechanism of this transport has not been revealed. In this study, we identified a rice Cd transporter, OsLCT1, involved in Cd transport to the grains. OsLCT1-GFP was localized at the plasma membrane in plant cells, and OsLCT1 showed Cd efflux activity in yeast. In rice plants, strong
OsLCT1
expression was observed in leaf blades and nodes during the reproductive stage. In the uppermost node,
OsLCT1
transcripts were detected around large vascular bundles and in diffuse vascular bundles. RNAi-mediated knockdown of
OsLCT1
did not affect xylem-mediated Cd transport but reduced phloem-mediated Cd transport. The knockdown plants of
OsLCT1
accumulated approximately half as much Cd in the grains as did the control plants. The content of other metals in rice grains and plant growth were not negatively affected by
OsLCT1
suppression. These results suggest that
OsLCT1
functions at the nodes in Cd transport into grains and that in a standard
japonica
cultivar, the regulation of
OsLCT1
enables the generation of “low-Cd rice” without negative effects on agronomical traits. These findings identify a transporter gene for phloem Cd transport in plants.
Polyfunctional responses by human T cells result from sequential release of cytokines
Authors: Han Qing , Bagheri Neda , Bradshaw Elizabeth M. , Hafler David A. , Lauffenburger Douglas A. , Love J. Christopher
Published: December 2011

The release of cytokines by T cells defines a significant part of their functional activity in vivo, and their ability to produce multiple cytokines has been associated with beneficial immune responses. To date, time-integrated end-point measurements have obscured whether these polyfunctional states arise from the simultaneous or successive release of cytokines. Here, we used serial, time-dependent, single-cell analysis of primary human T cells to resolve the temporal dynamics of cytokine secretion from individual cells after activation ex vivo. We show that multifunctional, Th1-skewed cytokine responses (IFN-γ, IL-2, TNFα) are initiated asynchronously, but the ensuing dynamic trajectories of these responses evolve programmatically in a sequential manner. That is, cells predominantly release one of these cytokines at a time rather than maintain active secretion of multiple cytokines simultaneously. Furthermore, these dynamic trajectories are strongly associated with the various states of cell differentiation suggesting that transient programmatic activities of many individual T cells contribute to sustained, population-level responses. The trajectories of responses by single cells may also provide unique, time-dependent signatures for immune monitoring that are less compromised by the timing and duration of integrated measures.
Antigen-specific CD4 T-cell help rescues exhausted CD8 T cells during chronic viral infection
Authors: Aubert Rachael D. , Kamphorst Alice O. , Sarkar Surojit , Vezys Vaiva , Ha Sang-Jun , Barber Daniel L. , Ye Lilin , Sharpe Arlene H. , Freeman Gordon J. , Ahmed Rafi
Published: December 2011

CD4 T cells play a critical role in regulating CD8 T-cell responses during chronic viral infection. Several studies in animal models and humans have shown that the absence of CD4 T-cell help results in severe dysfunction of virus-specific CD8 T cells. However, whether function can be restored in already exhausted CD8 T cells by providing CD4 T-cell help at a later time remains unexplored. In this study, we used a mouse model of chronic lymphocytic choriomeningitis virus (LCMV) infection to address this question. Adoptive transfer of LCMV-specific CD4 T cells into chronically infected mice restored proliferation and cytokine production by exhausted virus-specific CD8 T cells and reduced viral burden. Although the transferred CD4 T cells were able to enhance function in exhausted CD8 T cells, these CD4 T cells expressed high levels of the programmed cell death (PD)-1 inhibitory receptor. Blockade of the PD-1 pathway increased the ability of transferred LCMV-specific CD4 T cells to produce effector cytokines, improved rescue of exhausted CD8 T cells, and resulted in a striking reduction in viral load. These results suggest that CD4 T-cell immunotherapy alone or in conjunction with blockade of inhibitory receptors may be a promising approach for treating CD8 T-cell dysfunction in chronic infections and cancer.
End of empire: external and internal transitions in US policies for science, technology and innovation
Authors: Cozzens Susan
                      E.
Published: December 2011

Over the last 20 years, the shape of the global political economy has shifted dramatically, but US science and technology policy is continuing as though nothing has changed since the Cold War. Military research and development are prominent, and policies are still oriented towards large firms in existing industries rather than small, dynamic ones in new industries. US scientists and engineers are still world leaders in Mode 2 learning, as indicated in their active collaborations with industry; but large US markets seem to be keeping the system from putting effort into developing partnerships in the emerging economies. While the capability exists, then, the directional arrow is not pointed towards continued prosperity through innovation in the US economy. Science and technology policies are themselves in need of innovation.
Open innovation, the Haldane principle and the new production of knowledge: science policy and university–industry links in the UK after the financial crisis
Authors: Hughes Alan
Published: December 2011

The paper looks at the system of knowledge production and innovation in the UK from a Mode 2 perspective. It is critical of policy that focuses on science and engineering, on distinctions between basic and applied research, and that looks to notions of the entrepreneurial university. Extensive survey work of individual academics and UK firms reveals an extensive range of linkages between academics and industry, many personal rather than institutional. Formal mechanisms to link the university with the firm are rarely key initiators of connections. As key policy challenge is to design institutions and incentives that enhance the reflexive interplay between universities and external organisations and which build on the full range of interactions and disciplines.
Beyond SMART? A new framework for goal setting
Authors: Day Trevor , Tosey Paul
Published: December 2011

This article extends currently reported theory and practice in the use of learning goals or targets with students in secondary and further education. Goal‐setting and action‐planning constructs are employed in personal development plans (PDPs) and personal learning plans (PLPs) and are advocated as practice within the English national policy agenda with its focus on personalisation. The article argues that frameworks widely used for goal setting and action planning by UK educational practitioners, in particular SMART targets or goals, have yet to be rigorously examined in the light of relevant theory and practice. Doing so is important given contemporary emphasis on the dimensions of the learner experience regarded by ‘learning to learn’ practitioners as underpinning effective learning in the modern classroom. The article draws from social cognitive theory and achievement goal theory, including Zimmerman%s criteria for appropriate goals, to suggest an alternative framework for goal or target setting – ‘well‐formed outcomes’, a construct from the field of neuro‐linguistic programming (NLP). In comparison with SMART targets, the authors argue that well‐formed outcomes offer a more rigorous and holistic approach, by taking greater account of the learner%s identity, affective dimensions (feelings and emotions), social relations and values, as well as encouraging mental rehearsal.
Complexity of logic-based argumentation in Post's framework
Authors: Creignou Nadia , Schmidt Johannes , Thomas Michael , Woltran Stefan
Published: December 2011

Many proposals for logic-based formalisations of argumentation consider an argument as a pair (Φ,α), where the support Φ is understood as a minimal consistent subset of a given knowledge base which has to entail the claim α. In case the arguments are given in the full language of classical propositional logic reasoning in such frameworks becomes a computationally costly task. For instance, the problem of deciding whether there exists a support for a given claim has been shown to be [Formula: see text]-complete. In order to better understand the sources of complexity (and to identify tractable fragments), we focus on arguments given over formulæ in which the allowed connectives are taken from certain sets of Boolean functions. We provide a complexity classification for four different decision problems (existence of a support, checking the validity of an argument, relevance and dispensability) with respect to all possible sets of Boolean functions. Moreover, we make use of a general schema to enumerate all arguments to show that certain restricted fragments permit polynomial delay. Finally, we give a classification also in terms of counting complexity.
Evolutionary genetic dissection of human interferons
Authors: Manry Jérémy , Laval Guillaume , Patin Etienne , Fornarino Simona , Itan Yuval , Fumagalli Matteo , Sironi Manuela , Tichit Magali , Bouchier Christiane , Casanova Jean-Laurent , Barreiro Luis B. , Quintana-Murci Lluis
Published: December 2011

Interferons (IFNs) are cytokines that play a key role in innate and adaptive immune responses. Despite the large number of immunological studies of these molecules, the relative contributions of the numerous IFNs to human survival remain largely unknown. Here, we evaluated the extent to which natural selection has targeted the human IFNs and their receptors, to provide insight into the mechanisms that govern host defense in the natural setting. We found that some IFN-α subtypes, such as IFN-α6, IFN-α8, IFN-α13, and IFN-α14, as well as the type II IFN-γ, have evolved under strong purifying selection, attesting to their essential and nonredundant function in immunity to infection. Conversely, selective constraints have been relaxed for other type I IFNs, particularly for IFN-α10 and IFN-ε, which have accumulated missense or nonsense mutations at high frequencies within the population, suggesting redundancy in host defense. Finally, type III IFNs display geographically restricted signatures of positive selection in European and Asian populations, indicating that genetic variation at these genes has conferred a selective advantage to the host, most likely by increasing resistance to viral infection. Our population genetic analyses show that IFNs differ widely in their biological relevance, and highlight evolutionarily important determinants of host immune responsiveness.
An extracellular domain of the accessory β1 subunit is required for modulating BK channel voltage sensor and gate
Authors: Gruslova Aleksandra , Semenov Iurii , Wang Bin
Published: December 2011

A family of tissue-specific auxiliary β subunits modulates large conductance voltage- and calcium-activated potassium (BK) channel gating properties to suit their diverse functions. Paradoxically, β subunits both promote BK channel activation through a stabilization of voltage sensor activation and reduce BK channel openings through an increased energetic barrier of the closed-to-open transition. The molecular determinants underlying β subunit function, including the dual gating effects, remain unknown. In this study, we report the first identification of a β1 functional domain consisting of Y74, S104, Y105, and I106 residues located in the extracellular loop of β1. These amino acids reside within two regions of highest conservation among related β1, β2, and β4 subunits. Analysis in the context of the Horrigan-Aldrich gating model revealed that this domain functions to both promote voltage sensor activation and also reduce intrinsic gating. Free energy calculations suggest that the dual effects of the β1 Y74 and S104–I106 domains can be largely accounted for by a relative destabilization of channels in open states that have few voltage sensors activated. These results suggest a unique and novel mechanism for β subunit modulation of voltage-gated potassium channels wherein interactions between extracellular β subunit residues with the external portions of the gate and voltage sensor regulate channel opening.
Cycles, trends, and residual variation in the Iberian sardine (Sardina pilchardus) recruitment series and their relationship with the environment
Authors: Santos M. Begoña , González-Quirós Rafael , Riveiro Isabel , Cabanas José M. , Porteiro Carmela , Pierce Graham J.
Published: December 2011

Santos, M. B., González-Quirós, R., Riveiro, I., Cabanas, J. M., Porteiro, C., and Pierce, G. J. 2012. Cycles, trends, and residual variation in the Iberian sardine (Sardina pilchardus) recruitment series and their relationship with the environment. – ICES Journal of Marine Science, 69: 739–750. Recruitment variability is an important component of the dynamics of Iberian sardine (Sardine pilchardus). Since 2006, poor recruitment has led to a decrease in stock biomass, the latest in a series of such crises for sardine fisheries. Understanding the mechanisms behind recruitment fluctuations has been the objective of many previous studies, and various relationships between recruitment and environmental variables have been proposed. However, such studies face several analytical challenges, including short time-series and autocorrelated data. A new analysis of empirical relationships with environmental series is presented, using statistical methods designed to cope with these issues, including dynamic factor analysis, generalized additive models, and mixed models. Relationships are identified between recruitment and global (number of sunspots), regional (NAOAutumn), and local [winter wind strength, sea surface temperature (SST), and upwelling] environmental variables. Separating these series into trend and noise components permitted further investigation of the nature of the relationships. Whereas the other three environmental variables were related to the trend in recruitment, SST was related to residual variation around the trend, providing stronger evidence for a causal link, possible mechanisms for which are discussed. After the removal of trend and cyclic components, residual variation in recruitment is also weakly related to the previous year's spawning-stock biomass.
First Report of Rice stripe virus of Proso Millet in Korea
Authors: Yoon Y. , Jung J. , Lee B. , Lee Y. , Lee J. , Kim H. , Bae S. , Nam M. , Lee K. , Yago J.
Published: December 2011

Rice stripe virus (RSV; genus Tenuivirus) is a serious threat to rice production in Korea (2). In 1965, a disease outbreak was observed on rice in South Korea, with plants showing yellow stripe symptoms (2). Reoccurrence of RSV in rice was observed again in 1980 in Gyeonggi and Chungcheong. In 2001, RSV was estimated to be infecting approximately 4,663 ha of rice in the provinces of Gyeonggi and Gangwha and approximately 5,000 ha of riceland in the provinces of Buan and, Seocheon (3). Proso millet (Panicum miliaceum L.) is grown as a cereal grain crop and used mainly for human food in South Korea (1). In June 2009, proso millet plants that displayed yellow stripe symptoms were collected at Sinjeon-Myeon, Gangjin-Gun, and Jeollanam-do provinces, where an outbreak of RSV in rice was reported. Diseased plants tested positive to RSV with an ELISA Kit (KisanBio, Seoul, Korea). Total RNA was extracted from leaf tissue with an RNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA). RSV coat protein specific-primers were produced (5′ TGTGGAACATAGTCCCACAGTAAGT 3′(upstream), 5′ CTAAGCCGCAACCATTCCTCCAGT 3′(downstream). Reverse transcription-PCR confirmed the presence of a 494-bp product as predicted for the presence of RSV. The coat protein of RSV isolates collected from proso millet, rice, and foxtail millet in the same area was also sequenced. Results confirmed that phylogenetic relationships were of high homology: 98.9% between RSV isolates from rice and foxtail millet, 99.2% between isolates from rice (GenBank Accession No. JN245626) and proso millet (GenBank Accession No. JN245627); 99.6% between rice and foxtail millet (GenBank Accession No. JN245628); and 99.6% between foxtail millet and proso millet. In addition, sequence comparisons showed 96 to 99% identity with known RSV sequences available in GenBank (Accession No. X53563) (4). To our knowledge, this is the first report of RSV of proso millet in South Korea. The finding of this disease confirms further spread of the virus within the northern part of South Korea and the need for research to develop more effective management options to reduce the impact of RSV in proso millet.

References: (1) Y. Y. Choi et al. Biosci. Biotechnol. Biochem. 69:31, 2005. (2) B. C. Lee et al. Res. Plant Dis. 10:30, 2004. (3) B. C. Lee et al. Res. Plant Dis. 14:210, 2008. (4) Y. Zhu. J. Gen. Virol. 72:763, 1991.
First Report of Fenhexamid-Resistant Botrytis cinerea Causing Gray Mold on Heurchera in a North American Greenhouse
Authors: Moorman G. W. , Walker A.-S. , May S.
Published: December 2011

Greenhouse-grown Heuchera plants, treated with fenhexamid (Decree, SePRO, Carmel, IN; FRAC group 17 hydroxyanilide), with active gray mold were submitted to the Penn State Plant Disease Clinic in December 2010 from a commercial operation in north-central Pennsylvania. Genetic and phenotypic analyses identified the isolate as Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana (de Bary) Whetzel), HydR3 phenotype (2) and not B. pseudocinerea (previously Botrytis group I) (4), naturally resistant to fenhexamid (phenotype HydR1) (1). While 0.2 μg of fenhexamid per ml or less is required to slow mycelial growth and germ tube elongation of sensitive isolates by 50% (EC50), the radial growth EC50 of the Heuchera isolate was approximately 2,000 μg of fenhexamid per ml in culture. Five cucumber seedlings receiving 25 μl of 0.1 M dextrose containing the label rate of Decree (1,800 μg/ml) on the growing tip were inoculated with colonized agar in the drop. Five check plants received 25 μl of 0.1 M dextrose. B. cinerea from silica gel storage since 1988 was also tested. This experiment was repeated three times. The 1988 isolate killed all fungicide-free but no fenhexamid-treated plants. The Heuchera isolate killed all fungicide-free and fenhexamid-treated plants within 4 days. To our knowledge, this is the first report of B. cinerea from a greenhouse in North America with fenhexamid resistance. Resistance occurs in U.S. fields (3). The Heuchera isolate's HydR3 resistance phenotype (2) has been detected in Germany, Japan, and France and has mutations affecting the 3-keto reductase protein, encoded by the erg27 gene, the specific target of fenhexamid and involved in Botrytis sterol biosynthesis. The Decree label states that it is to be used only twice on a crop before switching to a different mode of action. Greenhouses have resident Botrytis populations that are likely to be exposed to any fungicide applied in the structure. Growers should consider using fenhexamid only twice in a particular greenhouse, rather than on a particular crop, before switching to a different mode of action.

References: (1) P. Leroux et al. Crop Prot. 18:687, 1999.(2) P. Leroux et al. Pest Manag. Sci. 58:876, 2002. (3) Z. Ma and T. J. Michailides. Plant Dis. 89:1083, 2005. (4) A.-S. Walker et al. Phytopathology 101:1433, 2011.
Ultrawide Bandwidth (UWB) Planar Monopole Antenna Backed by Novel Pyramidal-Shaped Cavity Providing Directional Radiation Patterns
Authors: Moody Robert A. , Sharma Satish K.
Published: December 2011

An ultrawideband (UWB) coplanar waveguide (CPW)-fed pentagon-shaped planar monopole antenna (PMA) backed by a novel pyramidal-shaped cavity is presented that provides directional radiation patterns. The pyramidal-shaped cavity reflector is placed at a fixed spacing from the UWB monopole antenna to provide impedance and radiation performance over 110% (3.1-10.6 GHz) frequency band. The PMA itself on a foam substrate provides stable gain variation within 3 dB over an impedance bandwidth (w.r.t.S11<; -10 dB) of 120% (3-12 GHz). The proposed cavity-backed PMA prototype antenna was fabricated, and experimental verification was performed for impedance matching and radiation patterns. The measured results show reasonable agreement with the simulated ones.
Developmental immune history affects adult immune function but not carotenoid‐based ornamentation in mallard ducks
Authors: Butler Michael W. , McGraw Kevin J.
Published: December 2011

1. Sexually selected traits often honestly advertise aspects of individual quality, such as immune function. Such traits have traditionally been thought to reveal real‐time information (e.g. current health state), but they may also reflect immunological conditions experienced during ontogeny, which can fundamentally shape survival prospects, adult immune function, and reproductive performance.

2. We tested the effects of immune challenges (injections of sheep red blood cells) during neonatal development on adult immune function and ornamental coloration in male mallard ducks (Anas platyrhynchos). Mallards have a carotenoid‐pigmented beak that plays a role in mate choice, and because carotenoids are also associated with immune responsiveness, carotenoid accumulation in body tissues may change as a function of immunological state during development and into adulthood.

3. We found that mallards that received immune challenges at the completion of growth (8–10 weeks old) had a reduced proinflammatory response (as measured by the local swelling response to phytohemagglutinin; PHA) as adults, compared to control birds and those receiving immune challenges at other developmental time points. Mallards that received immune challenges during the acquisition of nuptial plumage (13–15 weeks old) had an increased humoral immune response as adults, as assessed by antibody production to keyhole limpet hemocyanin (KLH). Body mass, adult beak colour, and carotenoid circulation were not affected by immune challenges issued at any point during development.

4. Circulating carotenoid levels prior to adult immune challenge and change in carotenoid titre over the course of the adult immune assessment period were correlated with degree of response to PHA and KLH at adulthood, as well as with nitric oxide production, which is associated with innate immunity. However, the direction of these correlations varied by type of immune assessment. Surprisingly, unlike in several previous studies, we found no link between beak coloration and adult immune function.

5. These findings demonstrate the importance of developmental immune challenges in shaping adult immune response, although the precise mechanisms remain unidentified. Moreover, we found support for the hypothesis that carotenoids are linked to immune function, because of the relationship between multiple immune responses and both initial and change in circulating carotenoid levels.

6. However, our study does not support the hypothesis that sexual signal expression reveals developmental immune history. Taken together, our findings suggest that the relationships between carotenoid physiology, carotenoid‐based ornamentation, and immune function are complex.
Semen variation in a population of fertile donors: evaluation in a French centre over a 34‐year period
Authors: Splingart C. , Frapsauce C. , Veau S. , Barthélémy C. , Royère D. , Guérif F.
Published: December 2011

Although it has been suspected that there is a decrease in semen quality over time, the results reported to date remain debatable because of methodological issues. The aim of the study reported here was to investigate the evolution of semen quality over time in a population of 1114 fertile candidates for sperm donation at CECOS, Tours, between 1976 and 2009. We investigated semen volume, sperm concentration, progressive motility, vitality, percentage of normal forms and multiple abnormalities index of the first ejaculate in this population. We did not find a decline in semen volume, whereas we observed a significant decrease in total sperm count (from 443.2 million in 1976 to 300.2 million in 2009), motility (from 64% in 1976 to 49% in 2009) and vitality (from 88% to 80%). Moreover, a significant decline in the percentage of normal forms was noted between 1976 and 1997 (from 67% to 26%) with a steady rise in the multiple abnormalities index between 1998 and 2009 (from 1.19 to 1.65). This study involving a population of fertile men from a restricted area revealed various degrees of decline in semen parameters over a period of 34 years. These findings will have to be compared with findings in other geographical areas.
Staff and patient views of the concept of hope on a stroke unit: a qualitative study
Authors: Tutton Elizabeth , Seers Kate , Langstaff Deborah , Westwood Martin
Published: December 2011

tutton e., seers k., langstaff d. & westwood m. (2012) Staff and patient views of the concept of hope on a stroke unit: a qualitative study. Journal of Advanced Nursing68(9), 2061–2069.

Aim.  This study explores the experience of hope for patients and staff in the context of a British stroke unit.

Background.  Hope is identified as a useful concept for exploring how people find meaning in recovery from illness. Uncovering the experience of hope in acute stroke care has provided evidence that can be used to facilitate rehabilitation.

Methods.  The methodology drew on the principles of ethnography, undertaking unstructured qualitative interviews with ten patients, ten multidisciplinary staff and 21 hours of participant observation including informal discussions with staff and patients. Data collection took place between November 2007 and November 2008.

Findings.  Four themes were identified: suffering, struggling with no hope and despair, hope for recovery and realistic hopefulness. Hope was experienced in the context of suffering a stroke demonstrated as loss of function, loss of mental capacity and dependency. Patients struggled to maintain a sense of hopefulness while feeling close to a slippery slope towards despair and death. Hope was expressed as a strong desire to recover, get back to normal and a time to reflect on their lives so far. Staff identified realistic hopefulness as focused on keeping things real while balancing giving hope and avoiding false hope.

Conclusion.  Hope is placed within the emotional challenges of suffering and struggle inherent in recovery from stroke. The staff work with patients’ hopes but offer realistic hopefulness as a practical strategy for recovery. Further interventions are required for working with feelings of despair or no hope.
Linking vegetation change, carbon sequestration and biodiversity: insights from island ecosystems in a long‐term natural experiment
Authors: Wardle David A. , Jonsson Micael , Bansal Sheel , Bardgett Richard D. , Gundale Michael J. , Metcalfe Daniel B.
Published: December 2011

1. Despite recent interest in linkages between above‐ and below‐ground communities and their consequences for ecosystem processes, much remains unknown about their responses to long‐term ecosystem change. We synthesize multiple lines of evidence from a long‐term ‘natural experiment’ to illustrate how ecosystem retrogression (the decline in ecosystem process rates due to long‐term absence of major disturbance) drives vegetation change, and thus above‐ground and below‐ground carbon (C) sequestration, and communities of consumer biota.

2. Our study system involves 30 islands in Swedish boreal forest that form a 5000‐year, fire‐driven retrogressive chronosequence. Here, retrogression leads to lower plant productivity and slower decomposition and a community shift from plants with traits associated with resource acquisition to those linked with resource conservation.

3. We present consistent evidence that above‐ground ecosystem C sequestration declines, while below‐ground and total C storage increases linearly for at least 5000 years following fire absence. This increase is driven primarily by changes in vegetation characteristics, impairment of decomposer organisms and absence of humus combustion.

4. Data from contrasting trophic groups show that during retrogression, biomass or abundance of plants and decomposer biota decreases, while that of above‐ground invertebrates and birds increases, due to different organisms accessing resources via distinct energy channels. Meanwhile, diversity measures of vascular plants and above‐ground (but not below‐ground) consumers respond positively to retrogression.

5. We show that taxonomic richness of plants and above‐ground consumers are positively correlated with total ecosystem C storage, suggesting that conserving old‐growth forests simultaneously maximizes biodiversity and C sequestration. However, we find little observational or experimental evidence that plant diversity is a major driver of ecosystem C storage on the islands relative to other biotic and abiotic factors.

6. Synthesis.Our study reveals that across contrasting islands differing in exposure to a key extrinsic driver (historical disturbance regime and resulting retrogression), there are coordinated responses of soil fertility, vegetation, consumer communities and ecosystem C sequestration, which all feed back to one another. It also highlights the value of well‐replicated natural experiments for tackling questions about above‐ground–below‐ground linkages over temporal and spatial scales that are otherwise unachievable.