bluuebunny/crossref_metadata_2025 huggingface dataset:
The Future of Harbin's Past
Authors: Carter James
Published: March 2012

Much of Harbin's early history revolved around struggles over the city's identity and also for control of the city's colonial legacy. The city's Russian past, in particular, has existed uneasily alongside its development as a Chinese city, and nearly a century after Russian control over the city ended, the competition over Harbin's identity continues to evolve. After many decades of denying and dismissing Harbin's colonial past, local, regional, and national Chinese governments are now exploiting that past as an asset for the city's economic development. Building on trends that first emerged in the 1990s, Harbin's Chinese rulers are now turning to the city's non-Chinese past as a means of competing in a global cultural and economic environment. More than attracting foreigners focused on nostalgia, however, Harbin seems eager to present itself as example of the “occidental” exotic for Chinese domestic tourists.
Deep-sea and pelagic rod visual pigments identified in the mysticete whales
Authors: BISCHOFF NICOLE , NICKLE BENJAMIN , CRONIN THOMAS W. , VELASQUEZ STEPHANI , FASICK JEFFRY I.
Published: March 2012

Our current understanding of the spectral sensitivities of the mysticete whale rod-based visual pigments is based on two species, the gray whale (Eschrichtius robustus) and the humpback whale (Megaptera novaeangliae) possessing absorbance maxima determined from difference spectra to be 492 and 497 nm, respectively. These absorbance maxima values are blueshifted relative to those from typical terrestrial mammals (≈500 nm) but are redshifted when compared to those identified in the odontocetes (479–484 nm). Although these mysticete species represent two of the four mysticete families, they do not fully represent the mysticete whales in terms of foraging strategy and underwater photic environments where foraging occurs. In order to better understand the spectral sensitivities of the mysticete whale rod visual pigments, we have examined the rod opsin genes from 11 mysticete species and their associated amino acid substitutions. Based on the amino acids occurring at positions 83, 292, and 299 along with the directly determined dark spectra from expressed odontocete and mysticete rod visual pigments, we have determined that the majority of mysticete whales possess deep-sea and pelagic like rod visual pigments with absorbance maxima between 479 and 484 nm. Finally, we have defined the five amino acid substitution events that determine the resulting absorbance spectra and associated absorbance maxima for the mysticete whale rod visual pigments examined here.
The value of the Black HarrierCircus maurusas a predictor of biodiversity in the plant-rich Cape Floral Kingdom, South Africa
Authors: JENKINS JULIA , SIMMONS ROBERT E. , CURTIS ODETTE , ATYEO MARION , RAIMONDO DOMATILLA , JENKINS ANDREW R.
Published: March 2012

Determining the efficacy of using indicator species to predict the spatial location of biodiversity hotspots is one way of maximising the conservation of biodiversity in already threatened habitats. Recent evidence from Europe suggests raptors can play such an indicator role, so we tested this approach with a globally threatened southern hemisphere species, the Black HarrierCircus maurus. We asked if this species, found in South Africa’s mega-diverse Cape Floral Kingdom, breeds in habitat fragments that were more diverse in terms of small mammals, birds and plants than unoccupied fragments of similar size. Renosterveld is a highly fragmented habitat that has lost > 90% of its original extent and remains only on privately-owned lands. Surveys of small mammals, birds and plants undertaken in 20 fragments in the Overberg region, South Africa, revealed nine with breeding harriers and 11 without harriers. Harrier-occupied fragments were associated with a 3.5 fold higher number of bird species and higher small mammal species richness than unoccupied ones. There was a lower abundance of most plants in occupied patches, except for red grassThemeda triandrawhich is an indicator of pristine renosterveld. Vegetation structure was significantly different, with harriers nesting on patches with taller, more open vegetation. While the diversity trends were not statistically significant, a positive trend between the presence of harriers and higher abundance of red grass – as an indicator of the more pristine state of the patch, suggests that harriers might allow biodiversity managers a heuristic approach for selecting the remaining patches of pristine renosterveld. The need for intensive sampling of several taxa leads to small samples and a lack of clear-cut trends for these top predators as indicators of plant diversity.
New Research on Gender in Political Psychology
Authors: Bos Angela L. , Schneider Monica C.
Published: March 2012

This symposium consists of three papers written after a small mentoring conference, New Research on Gender in Political Psychology, which was held in New Brunswick, New Jersey, March 4–5, 2011. As junior scholars, we received a grant from the National Science Foundation (#SES-1014854) to organize a conference for the purposes of mentoring pretenure faculty and promoting scholarship on gender in political psychology. Each of the three articles in this symposium focuses on a different aspect of the conference.
Integrating Gender into the Political Science Core Curriculum
Authors: Cassese Erin C. , Bos Angela L. , Duncan Lauren E.
Published: March 2012

The New Research on Gender in Political Psychology Conference brought together new and experienced teachers with interests in gender politics. The conference session “Teaching Gender throughout the Curriculum” generated a great deal of discussion concerning the pedagogical practice of gender mainstreaming. Gender mainstreaming—the integration of gendered content into courses required for a major—was recognized as one of 11 recommendations for reforming the undergraduate political science curriculum in the 1991 APSA report “Liberal Learning an The Political Science Major: A Report to the Profession” (popularly referred to as the Wahlke Report). Little information is available on the prevalence of gender courses in the undergraduate curriculum, but the data that does exist suggest such courses are uncommon (Brandes et al. 2001). We found virtually no data on the practice of gender mainstreaming in political science and little data in the way of assessing the impact of gendered content when students are exposed to it. This absence of data suggests gender mainstreaming has not emerged as a serious priority for curricular reform.
Forecasting the 2012 French Presidential Election
Authors: Foucault Martial , Nadeau Richard
Published: March 2012

Who will win the next French presidential election? Forecasting electoral results from political-economy models is a recent tradition in France. In this article, we pursue this effort by estimating a vote function based on both local and national data for the elections held between 1981 and 2007. This approach allows us to circumvent the small N problem and to produce more robust and reliable results. Based on a model including economic (unemployment) and political (approval and previous results) variables, we predict the defeat, although by a relatively small margin, of the right-wing incumbent Nicolas Sarkozy in the second round of the French presidential election to be held in May 2012.
A Window Seat on American Politics: Reflections on the GMFUS/APSA Congressional Fellowship
Authors: Bruns Sebastian
Published: March 2012

On a foggy Monday morning in late September 2010 in Kiel, Germany, I received a phone call from Berlin. “Do you have any plans for November through summer of next year?” the voice inquired. One of the two German Marshall Fund congressional fellows for the 2010–2011 round had suddenly dropped out and a replacement was needed. The call came five months after I had been initially rejected for the fellowship, and while my life had certainly moved on (I had begun work on my PhD dissertation at the University of Kiel and had expected to stay in Northern Germany for two or three years), I quickly regained my composure, asked for time to discuss this with my dissertation director as well as with my parents, and shortly thereafter accepted the selection. Exactly how I managed to cram the amount of work required for moving overseas into four weeks instead of the usual four to six months remains blurry. Eventually, however, I was able to tie up the loose ends in Germany, get the appropriate work visa for the United States, and even participate in a prestigious, long-planned naval reserve exercise that the German Navy's chief of naval operations had invited me to attend.
Document ranking refinement using a Markov random field model
Authors: VILLATORO ESAÚ , JUÁREZ ANTONIO , MONTES MANUEL , VILLASEÑOR LUIS , SUCAR L. ENRIQUE
Published: March 2012

This paper introduces a novel ranking refinement approach based on relevance feedback for the task of document retrieval. We focus on the problem of ranking refinement since recent evaluation results from Information Retrieval (IR) systems indicate that current methods are effective retrieving most of the relevant documents for different sets of queries, but they have severe difficulties to generate a pertinent ranking of them. Motivated by these results, we propose a novel method to re-rank the list of documents returned by an IR system. The proposed method is based on a Markov Random Field (MRF) model that classifies the retrieved documents as relevant or irrelevant. The proposed MRF combines: (i) information provided by the base IR system, (ii) similarities among documents in the retrieved list, and (iii) relevance feedback information. Thus, the problem of ranking refinement is reduced to that of minimising an energy function that represents a trade-off between document relevance and inter-document similarity. Experiments were conducted using resources from four different tasks of the Cross Language Evaluation Forum (CLEF) forum as well as from one task of the Text Retrieval Conference (TREC) forum. The obtained results show the feasibility of the method for re-ranking documents in IR and also depict an improvement in mean average precision compared to a state of the art retrieval machine.
Unsupervised dependency parsing without training
Authors: SØGAARD ANDERS
Published: March 2012

Usually unsupervised dependency parsers try to optimize the probability of a corpus by revising the dependency model that is assumed to have generated the corpus. In this paper we explore a different view in which a dependency structure is, among other things, a partial order on the nodes in terms of centrality or saliency. Under this assumption we directly model centrality and derive dependency trees from the ordering of words. The result is an approach to unsupervised dependency parsing that is very different from standard ones in that it requires no training data. The input words are ordered by centrality, and a parse is derived from the ranking using a simple deterministic parsing algorithm, relying on the universal dependency rules defined by Naseem et al. (Naseem, T., Chen, H., Barzilay, R., Johnson, M. 2010. Using universal linguistic knowledge to guide grammar induction. In Proceedings of Empirical Methods in Natural Language Processing, Boston, MA, USA, pp. 1234–44.). Our approach is evaluated on data from twelve different languages and is remarkably competitive.
Structure-guided supertagger learning
Authors: ZHANG YAO-ZHONG , MATSUZAKI TAKUYA , TSUJII JUN'ICHI
Published: March 2012

As described in this paper, we specifically examine the structural learning problem of a supertagging task. Supertagging is a task to assign the most probable lexical entry to each word in a sentence. A supertagger is extremely important for a lexicalized grammar parser because an accurate supertagger can greatly reduce lexical ambiguity in downstream parser. Supertagging is more challenging than conventional sequence labeling tasks (e.g., part-of-speech tagging). First, the supertags are numerous. Supertags are the lexical entries defined in a lexicalized grammar, which consists of rich syntactic/semantic information. Second, the inter-supertag relation is more complex. A proper supertag assignment is expected to be compatible with other supertag assignments in a sentence to construct a parse tree. Commonly used adjacent label features (e.g., first-order edge feature) in a sequence labeling model are too rough for the supertagging task. Long-range information is extremely important for the supertagging task. Two approaches to consider long-range information in a supertagger's training stage are proposed. Specifically, we propose a dependency-informed supertagger to use word-to-word dependency derived from a dependency parser and generate long-range features as soft constraints in the training. In the forest-guided supertagger, we constrain the classifier to learn in a grammar-satisfying space and use a CFG filter to impose grammar constraints for the update of model parameters. The experiments show that the proposed structure-guided supertaggers perform significantly better than the baseline supertaggers. Based on the improved supertaggers, theF-score of the final parser is also improved. Using the forest-guided supertagger in a shift-reduce HPSG parser, we achieved a competitive parsing performance of 89.31%F-score with higher parsing speed than that of a state-of-the-art HPSG parser.
Exploiting the Wikipedia structure in local and global classification of taxonomic relations
Authors: XUAN DO QUANG , ROTH DAN
Published: March 2012

Determining whether two terms have an ancestor relation (e.g. Toyota Camry and car) or a sibling relation (e.g. Toyota and Honda) is an essential component of textual inference in Natural Language Processing applications such as Question Answering, Summarization, and Textual Entailment. Significant work has been done on developing knowledge sources that could support these tasks, but these resources usually suffer from low coverage, noise, and are inflexible when dealing with ambiguous and general terms that may not appear in any stationary resource, making their use as general purpose background knowledge resources difficult. In this paper, rather than building a hierarchical structure of concepts and relations, we describe an algorithmic approach that, given two terms, determines the taxonomic relation between them using a machine learning-based approach that makes use of existing resources. Moreover, we develop a global constraint-based inference process that leverages an existing knowledge base to enforce relational constraints among terms and thus improves the classifier predictions. Our experimental evaluation shows that our approach significantly outperforms other systems built upon the existing well-known knowledge sources.
Parenting and the Emotional and Behavioural Adjustment of Young Children in Families with a Parent with Bipolar Disorder
Authors: Calam Rachel , Jones Steven , Sanders Matthew R. , Dempsey Robert , Sadhnani Vaneeta
Published: March 2012

Background: Children of parents with bipolar disorder are at increased risk of disturbance. Aims: This study examined relationships between parental mood, parenting, household organization and child emotional and behavioural adjustment in families with a parent with bipolar disorder to determine areas of specific need for parenting support. Method: 48 parents were recruited through advertisements via self-help organizations. The study was conducted online. Parental mood and activity was assessed by self-report questionnaires (CES-D, ISS, MDQ and SRM); parenting was assessed using the Parenting Scale (PS). The SDQ was used to assess the parent's view of their child's emotional and behavioural difficulties. The Confusion, Hubbub and Order Scale (CHAOS) assessed household organization. Results: Parents reported high levels of difficulties across all measures and scores were above clinical cut-offs on most scales. Children were reported as showing high levels of disturbance on the SDQ, including all sub-scales. Parenting and depression scores were significantly positively correlated, as were depression, parenting and CHAOS score. Regression analyses indicated that CHAOS was the strongest predictor of Total Difficulties and Emotional Symptoms on the SDQ. Conclusions: Families are likely to benefit from interventions tailored to meet their parenting needs.
TRIBUTE TO KAZUO NISHIMURA
Authors: Grandmont Jean-Michel
Published: March 2012

It is a great honor and a great pleasure for me to pay tribute to the accomplishments of Kazuo Nishimura on the occasion of this special issue. He is a great scientist, whose contributions I deeply admire and respect, and he is a good friend.
Vitamin D status in healthy Romanian caregivers and risk of respiratory infections
Authors: Porojnicu Alina C , Moroti-Constantinescu Ruxandra , Laslau Andrei , Lagunova Zoya , Dahlback Arne , Hristea Adriana , Moan Johan
Published: March 2012

Objectives

To investigate the vitamin D status during winter of a healthy population of hospital employees and to assess the correlation between vitamin D status and risk of infections in the upper respiratory tract.

Design

One hundred and ten healthy volunteers answered a questionnaire on their solar exposure habits and vitamin D intake and delivered one blood sample for quantification of vitamin D level (serum 25-hydroxyvitamin D (25(OH)D) concentration) during December 2007–January 2008. At the end of the winter we screened for the occurrence of respiratory infections and sought associations with vitamin D status.

Setting

Bucharest, Romania, 45°N.

Subjects

One hundred and ten healthy hospital employees.

Results

Eighty per cent of participants were vitamin D deficient (25(OH)D level below 50 nmol/l). The main determinant of serum 25(OH)D was sun exposure during the summer previous to the study (P= 0·02 in multivariate analysis). Intake of vitamin D, BMI and age played no significant role for the level of 25(OH)D. Overall we found a non-significant negative correlation between 25(OH)D level and new cases of infection (Spearman correlation coefficient of −0·12,P= 0·2).

Conclusions

Vitamin D status is alarmingly poor in active, relatively young women residing in Romania. If our results are reproduced by other investigations, action to improve vitamin D status at the population level is necessary. We were not able to show a statistically significant relationship between vitamin D status and infection risk in our material.
Diet quality and mental health in subsequent years among Canadian youth
Authors: McMartin Seanna E , Kuhle Stefan , Colman Ian , Kirk Sara FL , Veugelers Paul J
Published: March 2012

Objective

To examine the association between diet quality and the diagnosis of an internalizing disorder in children and adolescents.

Design

A prospective study examining the relationship between diet quality and mental health. FFQ responses of 3757 children were used to calculate a composite score for diet quality and its four components: variety, adequacy, moderation and balance. Physicians’ diagnoses on internalizing disorders were obtained by linking the children's dietary information to administrative health data. Negative binomial regression models were used to examine the association between diet quality and diagnosis of an internalizing disorder.

Setting

The Canadian province of Nova Scotia.

Subjects

A provincially representative sample of grade 5 students (age 10–11 years).

Results

Diet quality was not found to be associated with internalizing disorder in a statistically significant manner (incidence rate ratio = 1·09; 95 % CI 0·73, 1·63). However, relative to children with little variety in their diets, children with greater variety in their diet had statistically significant lower rates of internalizing disorder in subsequent years (incidence rate ratio = 0·45; 95 % CI 0·25, 0·82).

Conclusions

These findings suggest the importance of variety in children's diet and opportunities in the prevention of adolescent depression and anxiety.
CONVERSING WITH THOSE WITH WHOM WE DISAGREE: A RESPONSE TO AIKIN AND TALISSE'S ‘ARGUMENT IN MIXED COMPANY: MOM'S MAXIM VS. MILL'S PRINCIPLE' (THINK 27)
Authors: Watson Brenda
Published: March 2012

‘Mom's Maxim’ states that it is impolite to discuss religion or politics in mixed company. Instead, Aikin and Talisse want us to heed Mill's Principle: ‘He who knows only his own side of a case knows little of that.’ They want us actively to engage in debate with those who may disagree with us. To fail to do so may lead to irresponsible judgements, implied if not actually stated, of all those who hold positions different from our own. This points to a ‘dark side’ of Mom's Maxim.
CHRISTIANITY, HOMOSEXUAL BEHAVIOR, AND SEXISM
Authors: McBrayer Justin P.
Published: March 2012

Almost without exception, those in the West who think that homosexual behavior is morally wrong are Christians (the belief that all homosexual behavior is wrong is also common among the devotees of other Abrahamic religions, e.g. Islam, and perhaps among other cultural groups elsewhere in the world). But is it true that, assuming a traditional Christian worldview, there are strong reasons to think that all homosexual behavior is morally wrong? Traditionally, Christians have appealed to three independent sources to justify any given belief: church tradition, scripture, and reason. If a Christian is justified in believing that homosexual behavior is morally wrong, his reasons must appeal one of these three sources. As it turns out, however, this is a difficult trick to turn. None of these sources provides a clear reason to think that homosexual behavior is morally wrong, and at least one of them provides a clear reason for thinking that, in at least some cases, it is morally permissible.
COSMETIC SURGERY
Authors: Moen Ole Martin
Published: March 2012

As our wealth increases, more and more of us undergo cosmetic surgery. From tummy tucks, breast enlargements and nose jobs to hair transplants and face-lifts: You name it, they fix it.
Trust in judicial institutions: an empirical approach
Authors: ROUSSEY LUDIVINE , DEFFAINS BRUNO
Published: March 2012

This paper investigates the relationship between judicial resources and individuals’ trust in the justice system. We argue that the justice budget is likely to have a positive and significant impact on individuals’ trust in justice, thanks to its role as a signal when individuals face uncertainty regarding the judicial environment. We test this hypothesis empirically using three different budget-related variables: the justice budget per incoming case, the number of magistrates and the intensity of legal aid. Across our three regressions, we find a positive and significant correlation between judicial resources and individuals’ declared trust in the justice system. This positive relationship is robust to the introduction of socio-demographic, cultural, institutional and economic control variables. We finally offer empirical support to the intuition that the effect of the justice budget on trust in justice is likely to be greater when individuals are more satisfied with the level of democracy in their country.
A high-gain high-power amplifier MMIC for V-band applications using 100 nm AlGaN/GaN dual-gate HEMTs
Authors: Schwantuschke Dirk , Haupt Christian , Kiefer Rudolf , Brückner Peter , Seelmann-Eggebert Matthias , Tessmann Axel , Mikulla Michael , Kallfass Ingmar , Quay Rüdiger
Published: March 2012

In this paper we present the design and realization of a high-power amplifier in grounded coplanar transmission line technology using AlGaN/GaN dual-gate High electron mobility transistors (HEMTs) with a gate-length of 100 nm to achieve a high gain per stage and high output power. A large-signal model was extracted for the dual-gate HEMT based on the state-space approach. For the fabricated dual-stage amplifier a continuous-wave saturatedoutput power of up to 24.8 dBm (0.84 W/mm) was measured at 63 GHz for 20 V drain bias. A small-signal gain of more than 20 dB was achieved between 56 and 65 GHz.
The impact of polygamy on women's mental health: a systematic review
Authors: Shepard L. D.
Published: March 2012

Aims.

The purpose of this systematic review is to identify and appraise the present state of prevalence research on the mental health of polygynous women, or plural wives, and to summarize its implications for future research and social work practice.

Methods.

PsycInfo (1967 to November 2011) and Medline (1985 to November 2011) databases, systematic bibliography hand-searches, personal communication with a leading expert, and gray literature searching were applied in a systematic literature search of the prevalence of mental-health issues in polygynous women compared to monogamous women. Twenty-two studies meeting eligibility criteria were identified. Study characteristics, methods and findings were systematically extracted and appraised for quality.

Results.

The identified studies are of mixed methodological quality, but generally suggest a more significant prevalence of mental-health issues in polygynous women compared to monogamous women. Individual studies report a higher prevalence of somatization, depression, anxiety, hostility, psychoticism and psychiatric disorder in polygynous wives as well as reduced life and marital satisfaction, problematic family functioning and low self-esteem.

Conclusions.

The current state of the research reveals with moderate confidence, a more significant prevalence of mental-health issues in polygynous women as compared to monogamous women. Implications for practice and research are indicated.
Modeling the properties of plasmaspheric hiss: 1. Dependence on chorus wave emission
Authors: Chen Lunjin , Bortnik Jacob , Li Wen , Thorne Richard M. , Horne Richard B.
Published: March 2012

There is increasing evidence that plasmaspheric hiss is formed by the evolution of a portion of chorus waves that are excited in the plasmatrough and propagate into the plasmasphere. Comparison between the statistical spatial distributions of these two emissions in the morning sector during active times from THEMIS over ∼3 years shows that the two emissions have comparable peak intensities but are distinct in their spatial distributions. We present a modeling study of the hiss spectrum, based on ray tracing, by taking the observed chorus source region as an input in the magnetosphere, which contains cold and suprathermal electrons. Our modeling results show that we are able to reproduce the main features of typical hiss, including the frequency spectrum, wave normal angle and spatial distribution. However, the simulated hiss intensity is weaker (∼15 dB less) than the observed intensity, which suggests some modest internal amplification inside the plasmasphere. The responses of hiss to variations in the spatial distribution, wave normal angle distribution and frequency distribution of the source chorus are examined. We find that the majority of hiss formation is due to a small portion of chorus emission originating within ∼3 RE from the plasmapause, with wave normal directions pointing toward the Earth at an angle of 30°–60°, and over a frequency range of 0.1–0.3 fce. If the chorus power is made to increase closer to the plasmapause, the hiss intensity and the peak frequency also increases, which roughly mimics active geomagnetic conditions. Variations of the chorus source distribution do not significantly affect the wave normal angle distribution and frequency distribution of hiss, but does impact the absolute intensity of the resulting hiss.
Modeling the properties of plasmaspheric hiss: 2. Dependence on the plasma density distribution
Authors: Chen Lunjin , Bortnik Jacob , Li Wen , Thorne Richard M. , Horne Richard B.
Published: March 2012

Wave propagation plays an important role in linking the chorus source in the plasma trough region and the hiss emission in the plasmasphere. We investigate the dependence of plasmaspheric hiss on the background plasma density, which essentially controls the evolution of chorus after its generation at MLT = 10. The variation of plasma density under study includes variation of the location and width of the plasmapause, and the variation of the density distribution in the trough. We demonstrate that the plasmapause shape does not affect the peak hiss intensity significantly, but it does regulate the hiss intensity near the field‐aligned direction. As the plasmasphere contracts or the plasmapause width increases, the field‐aligned component of plasmaspheric hiss become relatively more intense, as does the intensity of hiss in the inner region, although the peak hiss intensity remains about the same. The trough density distribution, on the other hand, directly influences the accessibility of chorus rays into plasmasphere, and therefore plays an important role in the peak hiss intensity. As the density gradient in the plasma trough increases toward the plasmasphere, the resulting peak in the hiss intensity can increase by up to 10 dB.
Planetary and tidal wave‐type oscillations in the ionospheric sporadic E layers over Tehran region
Authors: Karami K. , Ghader S. , Bidokhti A. A. , Joghataei M. , Neyestani A. , Mohammadabadi A.
Published: March 2012

It is believed that in the lower ionosphere, particularly in the ionospheric sporadic E (Es) layers (90–130 km), the planetary and tidal wave‐type oscillations in the ionized component indicate the planetary and tidal waves in the neutral atmosphere. In the present work, the presence of wave‐type oscillations, including planetary and tidal waves in the ionospheric sporadic E layers over Tehran region is examined. Data measured by a digital ionosonde at the ionospheric station of the Institute of Geophysics, University of Tehran, from July 2006 to June 2007 are used to investigate seasonal variations of planetary and tidal waves activities. For the purpose of accurate comparison between different seasons, wavelet transform is applied to time series of foEs and h′Es, namely, the critical frequency and virtual height of Es layers, respectively. The results show that the sporadic E layers over Tehran region are strongly under the influence of upward propagation of waves from below. More specifically, among diverse range of periodicities in the sporadic E layers, we found that diurnal (24 hours) and semidiurnal (12 hours) oscillations in all seasons for both parameters. Moreover, terdiurnal (8 hours) tide‐like variation is observed during spring and summer for foEs parameter and summer and winter for h′Es. Furthermore, the results show that diurnal tidal waves obtain their maximum activities during autumn and winter seasons, and their activities decrease during the late spring and summer. In addition, periods of about 2, 4, 6, 10, 14, and 16 days in our observation verifies the hypothesis of upward propagation of planetary waves from lower atmosphere to the ionosphere. Moreover, planetary waves have their maximum activities during equinox.
A comparison of ISCCP land surface temperature with other satellite and in situ observations
Authors: Jiménez Carlos , Prigent Catherine , Catherinot Julie , Rossow William , Liang Pan , Moncet Jean‐Luc
Published: March 2012

Land surface skin temperature (LST) estimates from the International Satellite Cloud Climatology Project (ISCCP) are compared with estimates from the satellite instruments AIRS and MODIS, and in situ observations from CEOP. ISCCP has generally slightly warmer nighttime LSTs compared with AIRS and MODIS (global) and CEOP (at specific sites). Differences are smaller than 2K, similar to other reported biases between satellite estimates. Larger differences are found in the day‐time LSTs, especially for those regions where large LST values occur. Inspection of the AIRS and ISCCP brightness temperatures at the top of the atmosphere (TOA‐BT) reveals that where the LSTs differ so too do the TOA‐BT values. Area‐averaged day‐time TOA‐BT values can differ as much as 5K in very dry regions. This could be related to differences in sensor calibration, but also to the large LST gradients at the AIRS mid‐day overpass that likely amplify the impact of sensor mismatches. Part of the studied LST differences are also explained by discrepancies in the AIRS and ISCCP characterization of the surface (emissivity) and the atmosphere (water vapor). ISCCP calibration procedures are currently being revised to account better for sensor spectral response differences, and alternative atmospheric and surface data sets are being tested as part of a complete ISCCP reprocessing. This is expected to result in an improved ISCCP LST record.
Solute transport in dual‐permeability porous media
Authors: Leij Feike J. , Toride Nobuo , Field Malcolm S. , Sciortino Antonella
Published: March 2012

A dual‐advection dispersion equation (DADE) is presented and solved to describe solute transport in structured or layered porous media with different nonzero flow rates in two distinct pore domains with linear solute transfer between them. This dual‐permeability model constitutes a generalized version of the advection‐dispersion equation (ADE) for transport in uniform porous media and the mobile‐immobile model (MIM) for transport in media with a mobile and an immobile pore domain. Analytical tools for the DADE have mostly been lacking. An analytical solution has therefore been derived using Laplace transformation with time and modal decomposition based on matrix diagonalization, assuming the same dispersivity for both domains. Temporal moments are derived for the DADE and contrasted with those for the ADE and the MIM. The effective dispersion coefficient for the DADE approaches that of the ADE for a similar velocity in both pore domains and large values for the first‐order transfer parameter, and approaches that of the MIM for the opposite conditions. The solution of the DADE is used to illustrate how differences in pore water velocity between the domains and low transfer rates will lead to double peaks in the volume‐ or flux‐averaged concentration profiles versus time or position. The DADE is applied to optimize experimental breakthrough curves for an Andisol with a distinct intra‐ and interaggregate porosity. The DADE improved the description of the breakthrough data compared to the ADE and the MIM.
Evaluating effective reaction rates of kinetically driven solutes in large‐scale, statistically anisotropic media: Human health risk implications
Authors: Siirila Erica R. , Maxwell Reed M.
Published: March 2012

The interplay between regions of high and low hydraulic conductivity, degree of aquifer stratification, and rate‐dependent geochemical reactions in heterogeneous flow fields is investigated, focusing on impacts of kinetic sorption and local dispersion on plume retardation and channeling. Human health risk is used as an endpoint for comparison via a nested Monte Carlo scheme, explicitly considering joint uncertainty and variability. Kinetic sorption is simulated with finely resolved, large‐scale domains to identify hydrogeologic conditions where reactions are either rate limited (nonreactive), in equilibrium (linear equilibrium assumption is appropriate), or are sensitive to time‐dependent kinetic reactions. By utilizing stochastic ensembles, effective equilibrium conditions are examined, in addition to parameter interplay. In particular, the effects of preferential flow pathways and solute mixing at the field‐scale (marcrodispersion) and subgrid (local dispersion, LD) are examined for varying degrees of stratification and regional groundwater velocities (v). Results show effective reaction rates of kinetic ensembles with the inclusion of LD yield disequilibrium transport, even for averaged (or global) Damköholer numbers associated with equilibrium transport. Solute behavior includes an additive tailing effect, a retarded peak time, and results in an increased cancer risk. The inclusion of LD for nonreactive solutes in highly anisotropic media results in either induced solute retardation or acceleration, a new finding given that LD has previously been shown to affect only the concentration variance. The distribution, magnitude, and associated uncertainty of cancer risk are controlled by the up scaling of these small‐scale processes, but are strongly dependent on v and the source term.
Imaging of Erebus volcano using body wave seismic interferometry of Strombolian eruption coda
Authors: Chaput J. A. , Zandomeneghi D. , Aster R. C. , Knox H. , Kyle P. R.
Published: March 2012

Seismic interferometry is a recently developed theory that allows for the recovery of a medium's impulse response between two points should randomly distributed sources of white noise, or equivalently, a multiply scattered equipartioned wavefield, be present throughout the medium. We exploit the extremely scattering nature of volcanic media and seismic illumination from impulsive Strombolian eruptions to extract single‐station body wave Green's tensors at an unusually dense array of stations on Erebus volcano, Antarctica. We optimally rotate these Green's tensors for each notable arrival and back project them to construct a 3‐dimensional scattering map of the magma‐filled volcano conduit system, also corroborated by an independent active source tomography experiment using the same station distribution. This approach not only favors highly scattering media, contrarily to most conventional methods, but its passive nature (i.e., non‐anthropogenic sources) allows for studies of structural temporal variability, and possible extension into real‐time monitoring of active volcanoes.
Scale dependence of in‐situ permeability measurements in the Nankai accretionary prism: The role of fractures
Authors: Boutt David F. , Saffer Demian , Doan Mai‐Linh , Lin Weiren , Ito Takatoshi , Kano Yasuyuki , Flemings Peter , McNeill Lisa C. , Byrne Timothy , Hayman Nicholas W. , Moe Kyaw Thu
Published: March 2012

Modeling studies suggest that fluid permeability is an important control on the maintenance and distribution of pore fluid pressures at subduction zones generated through tectonic loading. Yet, to date, few data are available to constrain permeability of these materials, at appropriate scales. During IODP Expedition 319, downhole measurements of permeability within the uppermost accretionary wedge offshore SW Japan were made using a dual‐packer device to isolate 1 m sections of borehole at a depth of 1500 m below sea floor. Analyses of pressure transients using numerical models suggest a range of in‐situ fluid permeabilities (5E‐15–9E‐17 m2). These values are significantly higher than those measured on core samples (2E‐19 m2). Borehole imagery and cores suggests the presence of multiple open fractures at this depth of measurement. These observations suggest that open permeable natural fractures at modest fracture densities could be important contributors to overall prism permeability structure at these scales.
First in‐situ measurements of HF radar echoing targets
Authors: Moen J. , Oksavik K. , Abe T. , Lester M. , Saito Y. , Bekkeng T. A. , Jacobsen K. S.
Published: March 2012

The sounding rocket Investigation of Cusp Irregularities 2 (ICI‐2) was launched into the cusp ionosphere over Svalbard to investigate the production of decameter scale irregularities in the electron plasma associated with HF radar backscatter. The main mission objective was to obtain high‐resolution measurements of decameter scale electron plasma irregularities and to quantify the growth rate for the gradient drift instability (GDI). At the 5.7 kHz sampling rate of the absolute density measurements, ICI‐2 has provided the first documentation in terms of absolute electron density measurements of how 10‐m structures are located on km scale electron density gradients. ICI‐2 traversed a cusp electron density structure created by ongoing soft precipitation. 10‐m scale irregularities were generated at km scale density gradients. The estimated growth time for the GDI process was 10–50 seconds.
Characterization of the evolutionarily conserved iron–sulfur cluster of sirohydrochlorin ferrochelatase from Arabidopsis thaliana
Authors: Saha Kaushik , Webb Michael E. , Rigby Stephen E. J. , Leech Helen K. , Warren Martin J. , Smith Alison G.
Published: March 2012

Sirohaem is a cofactor of nitrite and sulfite reductases, essential for assimilation of nitrogen and sulfur. Sirohaem is synthesized from the central tetrapyrrole intermediate uroporphyrinogen III by methylation, oxidation and ferrochelation reactions. In Arabidopsis thaliana, the ferrochelation step is catalysed by sirohydrochlorin ferrochelatase (SirB), which, unlike its counterparts in bacteria, contains an [Fe–S] cluster. We determined the cluster to be a [4Fe–4S] type, which quickly oxidizes to a [2Fe–2S] form in the presence of oxygen. We also identified the cluster ligands as four conserved cysteine residues located at the C-terminus. A fifth conserved cysteine residue, Cys135, is not involved in ligating the cluster directly, but influences the oxygen-sensitivity of the [4Fe–4S] form, and possibly the affinity for the substrate metal. Substitution mutants of the enzyme lacking the Fe–S cluster or Cys135 retain the same specific activity in vitro and dimeric quaternary structure as the wild-type enzyme. The mutant variants also rescue a defined Escherichia coli sirohaem-deficient mutant. However, the mutant enzymes cannot complement Arabidopsis plants with a null AtSirB mutation, which exhibits post-germination arrest. These observations suggest an important physiological role for the Fe–S cluster in planta, highlighting the close association of iron, sulfur and tetrapyrrole metabolism.
Functional analysis of the protein phosphatase activity of PTEN
Authors: Zhang Xiaoqun Catherine , Piccini Antonella , Myers Michael P. , Van Aelst Linda , Tonks Nicholas K.
Published: March 2012

In vitro, the tumour suppressor PTEN (phosphatase and tensin homologue deleted on chromosome 10) displays intrinsic phosphatase activity towards both protein and lipid substrates. In vivo, the lipid phosphatase activity of PTEN, through which it dephosphorylates the 3 position in the inositol sugar of phosphatidylinositol derivatives, is important for its tumour suppressor function; however, the significance of its protein phosphatase activity remains unclear. Using two-photon laser-scanning microscopy and biolistic gene delivery of GFP (green fluorescent protein)-tagged constructs into organotypic hippocampal slice cultures, we have developed an assay of PTEN function in living tissue. Using this bioassay, we have demonstrated that overexpression of wild-type PTEN led to a decrease in spine density in neurons. Furthermore, it was the protein phosphatase activity, but not the lipid phosphatase activity, of PTEN that was essential for this effect. The ability of PTEN to decrease neuronal spine density depended upon the phosphorylation status of serine and threonine residues in its C-terminal segment and the integrity of the C-terminal PDZ-binding motif. The present study reveals a new aspect of the function of this important tumour suppressor and suggest that, in addition to dephosphorylating the 3 position in phosphatidylinositol phospholipids, the critical protein substrate of PTEN may be PTEN itself.
Tomato response to legume cover crop and nitrogen: differing enhancement patterns of fruit yield, photosynthesis and gene expression
Authors: Fatima Tahira , Teasdale John R. , Bunce Jim , Mattoo Autar K.
Published: March 2012

Excessive use of nitrogen (N) in crop production has impacted ecosystems by contaminating soil and water. Management of N in agriculture is therefore of global concern. Sustainable agriculture systems that use leguminous cover crops such as hairy vetch (Vicia villosa Roth) to fix N and enrich soil organic matter by fixing carbon provide an alternative strategy. N signalling pathways were found associated with delayed leaf senescence and disease tolerance of hairy vetch-grown tomatoes. To test whether N in hairy vetch is the only contributing factor leading to these phenotypes, we designed a pot experiment in the field to analyse growth and gene expression in tomatoes, one set with soil overwintered without a cover crop (bare soil) and the other with soil overwintered with a hairy vetch cover crop including the vetch residue on the soil surface. Additionally, supplementary N fertiliser was also provided to aid distinguishing tomato responses to vetch from those to inorganic N. Tomato fruit yield, plant biomass and photosynthesis were higher in plants grown in vetch than bare soil. Tomato growth and photosynthesis metrics exhibited a parabolic response to inorganic N in bare soil, suggesting the potential for N toxicity in pots with the highest N rate. Vetch-grown tomato plants mitigated these effects and maintained elevated photosynthetic rates at high inorganic N levels. Vetch-grown plants also mitigated a decline in expression of several genes regulating nitrogen and carbon metabolism and upregulated the defence-related gene, osmotin, relative to plants grown in bare soil. Thus, some of the positive responses of tomatoes to a hairy vetch cover crop observed in the field seem mediated by physiological cues other than the additional N provided by the vetch cover crop.
Preliminary characterisation of two early meiotic wheat proteins after identification through 2D gel electrophoresis proteomics
Authors: Khoo Kelvin H. P. , Able Amanda J. , Chataway Timothy K. , Able Jason A.
Published: March 2012

Various genetic-based approaches including mutant population screens, microarray analyses, cloning and transgenesis have broadened our knowledge of gene function during meiosis in plants. Nonetheless, these genetic tools are not without inherent limitations. One alternative approach to studying plant meiosis, especially in polyploids such as Triticum aestivum L. (bread wheat), is proteomics. However, protein-based approaches using proteomics have seldom been described, with only two attempts at studying early plant meiosis reported. Here, we report the investigation of early bread wheat meiosis using proteomics. Five differentially expressed protein spots were identified using 2D gel electrophoresis (2DGE) on protein extracts from four pooled stages of meiosis and three genotypes (Chinese Spring wild-type, ph1b and ph2a wheat mutant lines). Tandem mass spectrometry (MS/MS) identification of peptides from these protein spots led to the isolation and characterisation of the full-length clones of a wheat Speckle-type POZ protein, an SF21-like protein and HSP70, and a partial coding sequence of a hexose transporter. Significantly, the putative functions of the Speckle-type POZ protein and HSP70 were confirmed using in vitro DNA binding assays. Through the use of a 2DGE proteomics approach, we show that proteomics is a viable alternative to genetic-based approaches when studying meiosis in wheat. More significantly, we report a potential role for a Speckle-type POZ protein and a HSP70 in chromosome pairing during the early stages of meiosis in bread wheat.