bluuebunny/crossref_metadata_2025 huggingface dataset:
Law and Development in Nigeria: A Need for Activism
Authors: Lawan Mamman
Published: March 2011

This article explores the use of law in development at two levels in Nigeria. Development as a state duty has been provided for under the constitution, thereby creating socio-economic rights for citizens, albeit rights which are unenforceable. Seven development policies drawn up at different times have all also invoked law in one way or another to facilitate the achievement of their respective objectives. Both cases reflect the international trend in their respective discourses. The first approach mirrors the international human rights regime, while the second mimics international development discourse. While the instrumental use of law is desirable, this article argues that it is inadequate. More needs to be done to supplement it. First, courts need to adopt a radical interpretation of the constitutional provisions to make socio-economic rights enforceable. Secondly, people need to be active citizens through participation in the development process.
Liberating Malawi's Administrative Justice Jurisprudence from Its Common Law Shackles
Authors: Chirwa Danwood Mzikenge
Published: March 2011

The 1994 Malawian Constitution is unique in that it, among other things, recognizes administrative justice as a fundamental right and articulates the notion of constitutional supremacy. This right and the idea of constitutional supremacy have important implications for Malawi's administrative law, which was hitherto based on the common law inherited from Britain. This article highlights the difficulties that Malawian courts have faced in reconciling the right to administrative justice as protected under the new constitution with the common law. In doing so, it offers some insights into what the constitutionalization of administrative justice means for Malawian administrative law. It is argued that the constitution has altered the basis and grounds for judicial review so fundamentally that the Malawian legal system's marriage to the English common law can be regarded as having irretrievably broken down as far as administrative law is concerned.
DYNAMIC TIME SERIES BINARY CHOICE
Authors: de Jong Robert M. , Woutersen Tiemen
Published: March 2011

This paper considers dynamic time series binary choice models. It proves near epoch dependence and strong mixing for the dynamic binary choice model with correlated errors. Using this result, it shows in a time series setting the validity of the dynamic probit likelihood procedure when lags of the dependent binary variable are used as regressors, and it establishes the asymptotic validity of Horowitz’s smoothed maximum score estimation of dynamic binary choice models with lags of the dependent variable as regressors. For the semiparametric model, the latent error is explicitly allowed to be correlated. It turns out that no long-run variance estimator is needed for the validity of the smoothed maximum score procedure in the dynamic time series framework.
SIMULTANEOUS SPECIFICATION TESTING OF MEAN AND VARIANCE STRUCTURES IN NONLINEAR TIME SERIES REGRESSION
Authors: Xi Chen Song , Gao Jiti
Published: March 2011

This paper proposes a nonparametric simultaneous test for parametric specification of the conditional mean and variance functions in a time series regression model. The test is based on an empirical likelihood (EL) statistic that measures the goodness of fit between the parametric estimates and the nonparametric kernel estimates of the mean and variance functions. A unique feature of the test is its ability to distribute natural weights automatically between the mean and the variance components of the goodness-of-fit measure. To reduce the dependence of the test on a single pair of smoothing bandwidths, we construct an adaptive test by maximizing a standardized version of the empirical likelihood test statistic over a set of smoothing bandwidths. The test procedure is based on a bootstrap calibration to the distribution of the empirical likelihood test statistic. We demonstrate that the empirical likelihood test is able to distinguish local alternatives that are different from the null hypothesis at an optimal rate.
COMMENT ON “WEAK CONVERGENCE TO A MATRIX STOCHASTIC INTEGRAL WITH STABLE PROCESSES”
Authors: Paulauskas Vygantas , Rachev Svetlozar T. , Fabozzi Frank J.
Published: March 2011

In this comment we identify a lacuna in a proof in the paper by M. Caner published in 1997 in Econometric Theory concerning the weak limit behavior of various expressions involving heavy-tailed multivariate vectors and the convergence of stochastic integrals. In a later paper (Caner, 1998) the results for these limit relations are used to formulate tests for cointegration with infinite variance errors.
Quantification of intra-regional propagule movements in the Antarctic
Authors: Lee Jennifer E. , Chown Steven L.
Published: March 2011

Management of non-native species introductions is a conservation priority in the Antarctic region. However, despite the recognised importance of intra-regional propagule transfer, the majority of studies have focused on inter-regional pathways (i.e. from outside of the Antarctic region). Here we quantify the number of seeds carried by expeditioners who have visited sub-Antarctic Marion Island. We recorded 420 seeds from 225 items of clothing, with seeds found on 52% of the items and soil on 45% of them. The median number of seeds for field-based and station-based personnel was 20.5 and 3 per person, respectively. Waterproof trousers and socks, particularly those of field workers, carry the greatest number of propagules (for field workers, medians of 5 and 6.5, respectively) and therefore should be the focus of intra-regional management interventions. Amongst the seeds found entrained within clothing several were from species which are widespread aliens in the Antarctic region includingAgrostis stolonifera,Poa annuaandSagina procumbens, and indigenous zoochorous species (Acaena magellanica,Uncinia compacta) were also well represented. The present data provide quantitative evidence in support of previous, largely hypothetical concerns about the risks of intra-regional propagule transfer in the Antarctic.
Developing Asia's Sovereign Wealth Funds: The Santiago Principles and the Case for Self Regulation
Authors: PARK Donghyun , ESTRADA Gemma Esther
Published: March 2011

Concerns in host countries about the investment activities of sovereign wealth funds (SWFs) arise from their non-commercial motives and lack of transparency. In response to such concerns, investor countries have begun to work together to set up the norms and laws which will define the governance and regulation of SWFs. In particular, the Santiago Principles have given birth to a set of voluntary principles and guidelines designed to guide their investment behaviour. In this article, we point out that the Santiago Principles are fundamentally consistent with the commercial self-interest of SWFs, which bodes well for the prospects of their voluntary adoption. The Santiago Principles serve a highly valuable role as a mechanism which signals and crystallizes the commitment of SWFs to comply with the basic rules and regulations of the countries in which they invest.
Cooperation and cheating in Pseudomonas aeruginosa: the roles of the las, rhl and pqs quorum-sensing systems
Authors: Wilder Cara N , Diggle Stephen P , Schuster Martin
Published: March 2011

Pseudomonas aeruginosa coordinates the transcription of hundreds of genes, including many virulence genes, through three hierarchically arranged quorum-sensing (QS) systems, namely las, rhl and pqs. Each system consists of genes involved in autoinducer synthesis, lasI, rhlI and pqsABCDH, as well as cognate-regulatory genes, lasR, rhlR and pqsR. In this study, we analyzed the social behavior of signal-blind (ΔlasR, ΔrhlR, ΔpqsR) and signal-negative (ΔlasI, ΔrhlI, ΔpqsA) mutants from each QS system. As each system controls extracellular common goods but differs in the extent of regulatory control, we hypothesized that all signal-blind mutants can behave as cheaters that vary in their ability to invade a QS-proficient population. We found that lasR and pqsR, but not rhlR, mutants evolve from a wild-type ancestor in vitro under conditions that favor QS. Accordingly, defined lasR and pqsR mutants enriched in wild-type co-culture, whereas rhlR and all signal-negative mutants did not. Both lasR and pqsR mutants enriched with negative frequency dependence, suggesting social interactions with the wild type, although the pqsR mutant also grew well on its own. Taken together, the lasR mutant behaved as a typical cheater, as reported previously. However, the pqsR and rhlR mutants exhibited more complex behaviors, which can be sufficiently explained by positive and negative pleiotropic effects through differential regulation of pqs gene expression in the interconnected QS network. The evolutionary approach adopted here may account for the prevalence of naturally occurring QS mutants.
Chemolithotrophic acetogenic H2/CO2 utilization in Italian rice field soil
Authors: Liu Fanghua , Conrad Ralf
Published: March 2011

Acetate oxidation in Italian rice field at 50 °C is achieved by uncultured syntrophic acetate oxidizers. As these bacteria are closely related to acetogens, they may potentially also be able to synthesize acetate chemolithoautotrophically. Labeling studies using exogenous H2 (80%) and 13CO2 (20%), indeed demonstrated production of acetate as almost exclusive primary product not only at 50 °C but also at 15 °C. Small amounts of formate, propionate and butyrate were also produced from 13CO2. At 50 °C, acetate was first produced but later on consumed with formation of CH4. Acetate was also produced in the absence of exogenous H2 albeit to lower concentrations. The acetogenic bacteria and methanogenic archaea were targeted by stable isotope probing of ribosomal RNA (rRNA). Using quantitative PCR, 13C-labeled bacterial rRNA was detected after 20 days of incubation with 13CO2. In the heavy fractions at 15 °C, terminal restriction fragment length polymorphism, cloning and sequencing of 16S rRNA showed that Clostridium cluster I and uncultured Peptococcaceae assimilated 13CO2 in the presence and absence of exogenous H2, respectively. A similar experiment showed that Thermoanaerobacteriaceae and Acidobacteriaceae were dominant in the 13C treatment at 50 °C. Assimilation of 13CO2 into archaeal rRNA was detected at 15 °C and 50 °C, mostly into Methanocellales, Methanobacteriales and rice cluster III. Acetoclastic methanogenic archaea were not detected. The above results showed the potential for acetogenesis in the presence and absence of exogenous H2 at both 15 °C and 50 °C. However, syntrophic acetate oxidizers seemed to be only active at 50 °C, while other bacterial groups were active at 15 °C.
Apical protein transport and lumen morphogenesis in polarized epithelial cells
Authors: Willenborg Carly , Prekeris Rytis
Published: March 2011

Segregation of the apical and basolateral plasma membrane domains is the key distinguishing feature of epithelial cells. A series of interrelated cues and processes follow this primary polarization event, resulting in the morphogenesis of the mammalian epithelium. This review focuses on the role of the interactions between the extracellular matrix and neighbouring cells during the initiation and establishment of epithelial polarity, and the role that membrane transport and polarity complexes play in this process. An overview of the formation of the apical junctional complexes is given in relation to the generation of distinct membrane domains characterized by the asymmetric distribution of phosphoinositides and proteins. The mechanisms and machinery utilized by the trafficking pathways involved in the generation and maintenance of this apical-basolateral polarization are expounded, highlighting processes of apical-directed transport. Furthermore, the current proposed mechanisms for the organization of entire networks of cells into a structured, polarized three-dimensional structure are described, with an emphasis on the proposed mechanisms for the formation and expansion of the apical lumen.
DOE looks again at inertial fusion as a potential clean-energy source
Authors: Kramer David
Published: March 2011

As ignition experiments get under way at the National Ignition Facility, an official says the Department of Energy should be preparing for a decision on whether laser-driven fusion energy can be harnessed.
Water on the Moon
Authors: Elkins-Tanton Linda T.
Published: March 2011

The Moon is not wet like Earth, and it doesn’t have frozen icecaps like those on Mars. But it might be just a tiny bit damp, both inside and on its surface.
Somatic hypermutation of human mitochondrial and nuclear DNA by APOBEC3 cytidine deaminases, a pathway for DNA catabolism
Authors: Suspène Rodolphe , Aynaud Marie-Ming , Guétard Denise , Henry Michel , Eckhoff Grace , Marchio Agnès , Pineau Pascal , Dejean Anne , Vartanian Jean-Pierre , Wain-Hobson Simon
Published: March 2011

The human
APOBEC3
(
A3A–A3H
) locus encodes six cytidine deaminases that edit single-stranded DNA, the result being DNA peppered with uridine. Although several cytidine deaminases are clearly restriction factors for retroviruses and hepadnaviruses, it is not known if APOBEC3 enzymes have roles outside of these settings. It is shown here that both human mitochondrial and nuclear DNA are vulnerable to somatic hypermutation by A3 deaminases, with APOBEC3A standing out among them. The degree of editing is much greater in patients lacking the uracil DNA-glycolyase gene, indicating that the observed levels of editing reflect a dynamic composed of A3 editing and DNA catabolism involving uracil DNA-glycolyase. Nonetheless, hyper- and lightly mutated sequences went hand in hand, raising the hypothesis that recurrent low-level mutation by APOBEC3A could catalyze the transition from a healthy to a cancer genome.
Agile small state agency: heuristic plays and flexible national identity markers in Finnish foreign policy
Authors: Aaltola Mika
Published: March 2011

Studies of small state foreign policy tend to draw relatively bleak conclusions when it comes to small state agency. However, I will examine alternative and more positive modalities of small state agency. One such modality is agility, the strategic maneuverability to take advantage of a chancy environment. Besides leading to dangerous rigidities and biases, particular types of foreign policy imageries and heuristics may also facilitate experimental and agile agency. In studying this possibility, Finland is chosen as an illustrative case because historically Finland has faced a particularly constraining geopolitical context and because it has managed to adapt to multiple upheavals and to different geopolitical contexts. The emphasis is on the heuristic dynamics inherent in Finnish foreign policy culture that have allowed it to actively meet the emerging challenges. Instead of taking a detailed historical approach, I seek to understand the role of the relatively flexible and combinable embodied cultural models, i.e. thick images. They allow for agency-related experimentation that may bring added value that allows Finland to exceed the constraints of the brute geopolitical position. After reviewing multiple embodied foreign policy images, I will use them to analyse New Year's speeches by the Finnish Presidents Ahtisaari and Halonen in order to see how the fickle present is made to resonate innovatively with the known, commonplace, and mythical.
The relationship between religious and national identity in the case of Transylvanian Saxons (1933–1944)
Authors: Cercel Cristian
Published: March 2011

Hitler's coming to power in Germany had its key consequences upon the fate of the German minorities in Central and Eastern Europe. The German community in Romania constituted no exception. After 1933, a process of radicalization can be noticed in the case of the Transylvanian Saxons, one of the several German-speaking groups in Romania. The phenomenon has already been analyzed in its political and economic dimensions, yet not so much in its social ones. This article looks at the latter aspect, its argument being that the Nazification of the Transylvanian Saxon community can be best comprehended by using a conceptual framework developed by political scientist Donald Horowitz in the early 1970s. The analysis uses a series of contemporary sources (diaries, issues of the official periodical of the Lutheran Church in Transylvania,Kirchliche Blätter), but also a wide range of secondary sources, academic and literary. Consequently, the article shows that especially after 1933, the Lutheran affiliation, highly relevant for the production and reproduction of the traditional model of Transylvanian Saxon identity, shifted from the status of a criterion of identity to a mere identification indicium. At the same time, the attraction of a (Pan-) German identity, with its Nazi anchors, became stronger and the center of gravity for Transylvanian Saxon identity radically moved towards German ethnicity, in its National-Socialist understanding.
Civil society versus nationalizing state? Advocacy of minority rights in the post-socialist Baltic states
Authors: Agarin Timofey
Published: March 2011

Strong civil society provides individuals with arenas to bring their interests to the attention of policymakers. In so doing, civil society organizations (CSOs) can support state policies, but can also criticize policies. This paper argues that most minority rights advocacy CSOs in the Baltic states have little say in the crafting of policy and are compartmentalized into the existing agendas, with only a few groups able to evaluate policies independently. It concludes that the Baltic civil society is weak because the CSOs working on minority issues ask policymakers either too much, or too little. The findings suggest that policymakers quell criticism of their work from the side of the CSOs by ignoring their activities. Alternatively, by funding the CSO that shores up the state agenda, policymakers delegate their responsibilities to civic actors, keep critical voices from public debates and claim that their policies have the full support of a vibrant civil society. This paper investigates the options available for civil society actors to relate to policymakers in a nationalizing state by drawing on the data collected in 77 semi-structured interviews with the CSOs working with Russian and Polish minorities in the Baltic states between 2006 and 2009.
National identity and money: Czech and Slovak Lands 1918–2008
Authors: Veselkova Marcela , Horvath Julius
Published: March 2011

An expanding literature on money and identity is built around the assumption that political elites deliberately use currency design to foster national identities. However, the empirical evidence in favor of this assumption has been fragmentary. Drawing on detailed primary sources we demonstrate nationalist intentions of political elites involved in currency design. We also examine how political elites use banknotes as official pronouncements on who is and who is not part of the nation and what the official attitude toward foreigners is. By tracing changes in the inclusive and exclusive messages directed at an intra-state or international audience we document that there is no connection between ingroup (national) love and outgroup (foreigners, minorities, opposition) hate. The amount of exclusive messages to outgroups culminated in conditions of perceived threat when political leaders tried to mobilize pre-existing identities to secure or maintain political power. In contrast, the officials deliberately tried to broaden ingroup boundaries in order to build international communities. Finally, we document that in the case of limited support for the new conception of identity, officials tried to depict the old and the new identity as complementary, embedding the new identity in existing discourses.
Spreads and Non‐Convergence in Chicago Board of Trade Corn, Soybean, and Wheat Futures: Are Index Funds to Blame?
Authors: Irwin Scott H. , Garcia Philip , Good Darrel L. , Kunda Eugene L.
Published: March 2011

This paper evaluates the role that index funds have played in recent convergence problems of Chicago Board of Trade corn, soybean, and wheat futures contracts. These new market participants are widely considered to have inflated futures prices and/or expanded spreads between futures prices. Large spreads in futures markets contribute to a lack of convergence by uncoupling cash and futures markets. Statistical tests provide no evidence that rolling of positions by index funds or the initiation of large index positions in a “crowded market space” have contributed to an expansion of the spreads.
eCEO: an efficient Cloud Epistasis cOmputing model in genome-wide association study
Authors: Wang Zhengkui , Wang Yue , Tan Kian-Lee , Wong Limsoon , Agrawal Divyakant
Published: March 2011

Motivation: Recent studies suggested that a combination of multiple single nucleotide polymorphisms (SNPs) could have more significant associations with a specific phenotype. However, to discover epistasis, the epistatic interactions of SNPs, in a large number of SNPs, is a computationally challenging task. We are, therefore, motivated to develop efficient and effective solutions for identifying epistatic interactions of SNPs.

Results: In this article, we propose an efficient Cloud-based Epistasis cOmputing (eCEO) model for large-scale epistatic interaction in genome-wide association study (GWAS). Given a large number of combinations of SNPs, our eCEO model is able to distribute them to balance the load across the processing nodes. Moreover, our eCEO model can efficiently process each combination of SNPs to determine the significance of its association with the phenotype. We have implemented and evaluated our eCEO model on our own cluster of more than 40 nodes. The experiment results demonstrate that the eCEO model is computationally efficient, flexible, scalable and practical. In addition, we have also deployed our eCEO model on the Amazon Elastic Compute Cloud. Our study further confirms its efficiency and ease of use in a public cloud.

Availability: The source code of eCEO is available at http://www.comp.nus.edu.sg/~wangzk/eCEO.html.

Contact:  wangzhengkui@nus.edu.sg
Human variation database: an open-source database template for genomic discovery
Authors: Fejes Anthony P. , Khodabakhshi Alireza Hadj , Birol Inanc , Jones Steven J. M.
Published: March 2011

Motivation: Current public variation databases are based upon collaboratively pooling data into a single database with a single interface available to the public. This gives little control to the collaborator to mine the database and requires that they freely share their data with the owners of the repository. We aim to provide an alternative mechanism: providing the source code and application programming interface (API) of a database, enabling researchers to set up local versions without investing heavily in the development of the resource and allowing for confidential information to remain secure.

Results: We describe an open-source database that can be installed easily at any research facility for the storage and analysis of thousands of next-generation sequencing variations. This database is built using PostgreSQL 8.4 (The PostgreSQL Global Development Group. postgres 8.4: http://www.postgresql.org) and provides a novel method for collating and searching across the reported results from thousands of next-generation sequence samples, as well as rapidly accessing vital information on the origin of the samples. The schema of the database makes rapid and insightful queries simple and enables easy annotation of novel or known genetic variations. A modular and cross-platform Java API is provided to perform common functions, such as generation of standard experimental reports and graphical summaries of modifications to genes. Included libraries allow adopters of the database to quickly develop their own queries.

Availability: The software is available for download through the Vancouver Short Read Analysis Package on Sourceforge, http://vancouvershortr.sourceforge.net. Instructions for use and deployment are provided on the accompanying wiki pages.

Contact:  afejes@bcgsc.ca
Pacific salmon abundance trends and climate change
Authors: Irvine James R. , Fukuwaka Masa-aki
Published: March 2011

Irvine, J. R., and Fukuwaka, M. 2011. Pacific salmon abundance trends and climate change. – ICES Journal of Marine Science, 68: 1122–1130. Understanding reasons for historical patterns in salmon abundance could help anticipate future climate-related changes. Recent salmon abundance in the northern North Pacific Ocean, as indexed by commercial catches, has been among the highest on record, with no indication of decline; the 2009 catch was the highest to date. Although the North Pacific Ocean continues to produce large quantities of Pacific salmon, temporal abundance patterns vary among species and areas. Currently, pink and chum salmon are very abundant overall and Chinook and coho salmon are less abundant than they were previously, whereas sockeye salmon abundance varies among areas. Analyses confirm climate-related shifts in abundance, associated with reported ecosystem regime shifts in approximately 1947, 1977, and 1989. We found little evidence to support a major shift after 1989. From 1990, generally favourable climate-related marine conditions in the western North Pacific Ocean, as well as expanding hatchery operations and improving hatchery technologies, are increasing abundances of chum and pink salmon. In the eastern North Pacific Ocean, climate-related changes are apparently playing a role in increasing chum and pink salmon abundances and declining numbers of coho and Chinook salmon.
Potential contribution of the Internet to a global community of practice for fishery management
Authors: Garcia Serge M.
Published: March 2011

Garcia, S. M. 2011. Potential contribution of the Internet to a global community of practice for fishery management. – ICES Journal of Marine Science, 68: 1800–1804. Managing complex socio-ecological fishery systems, following an Ecosystem Approach to Fisheries, calls for a broad range of information covering many components of the system, intensified sharing of data and knowledge (to accelerate social learning and adaptive management), and a much tighter collaboration between disciplines and stakeholders. I argue that the time has come to establish one or more communities of practice (sensu Wenger) and that the Internet could be used efficiently for this purpose, enhancing the co-evolution of science and decision-making. Important Internet resources exist and can be mobilized, but the contribution of fishery science is still too fragmented and that of the fishing industry is embryonic. This paper suggests a web infrastructure that would facilitate the needed change.
Academic Performance in Adolescence after Inguinal Hernia Repair in Infancy
Authors: Hansen Tom G. , Pedersen Jacob K. , Henneberg Steen W. , Pedersen Dorthe A. , Murray Jeffrey C. , Morton Neil S. , Christensen Kaare
Published: March 2011

Background

Although animal studies have indicated that general anesthetics may result in widespread apoptotic neurodegeneration and neurocognitive impairment in the developing brain, results from human studies are scarce. We investigated the association between exposure to surgery and anesthesia for inguinal hernia repair in infancy and subsequent academic performance.

Methods

Using Danish birth cohorts from 1986-1990, we compared the academic performance of all children who had undergone inguinal hernia repair in infancy to a randomly selected, age-matched 5% population sample. Primary analysis compared average test scores at ninth grade adjusting for sex, birth weight, and paternal and maternal age and education. Secondary analysis compared the proportions of children not attaining test scores between the two groups.

Results

From 1986-1990 in Denmark, 2,689 children underwent inguinal hernia repair in infancy. A randomly selected, age-matched 5% population sample consists of 14,575 individuals. Although the exposure group performed worse than the control group (average score 0.26 lower; 95% CI, 0.21-0.31), after adjusting for known confounders, no statistically significant difference (-0.04; 95% CI, -0.09 to 0.01) between the exposure and control groups could be demonstrated. However, the odds ratio for test score nonattainment associated with inguinal hernia repair was 1.18 (95% CI, 1.04-1.35). Excluding from analyses children with other congenital malformations, the difference in mean test scores remained nearly unchanged (0.05; 95% CI, 0.00-0.11). In addition, the increased proportion of test score nonattainment within the exposure group was attenuated (odds ratio = 1.13; 95% CI, 0.98-1.31).

Conclusion

In the ethnically and socioeconomically homogeneous Danish population, we found no evidence that a single, relatively brief anesthetic exposure in connection with hernia repair in infancy reduced academic performance at age 15 or 16 yr after adjusting for known confounding factors. However, the higher test score nonattainment rate among the hernia group could suggest that a subgroup of these children are developmentally disadvantaged compared with the background population.
5-Hydroxytryptamine Type 3 Receptor Modulates Opioid-induced Hyperalgesia and Tolerance in Mice
Authors: Liang De-Yong , Li XiangQi , Clark J. David
Published: March 2011

Background

Opioid-induced hyperalgesia (OIH) and tolerance are challenging maladaptations associated with opioids in managing pain. Recent genetic studies and the existing literature suggest the 5-hydroxytryptamine type 3 (5-HT3) receptor participates in these phenomena. The location of the relevant receptor populations and the interactions between the 5-HT3 system and other systems controlling OIH and tolerance have not been explored, however. We hypothesized that 5-HT3 receptors modulate OIH and tolerance, and that this modulation involves the control of expression of multiple neurotransmitter and receptor systems.

Methods

C57BL/6 mice were exposed to a standardized 4-day morphine administration protocol. The 5-HT3 antagonist ondansetron was administered either during or after the conclusion of morphine administration. Mechanical testing was used to quantify OIH, and thermal tail-flick responses were used to measure morphine tolerance. In other experiments spinal cord and dorsal root ganglion tissues were harvested for analysis of messenger RNA concentrations by real-time polymerase chain reaction or immunochemistry analysis.

Results

The results showed that (1) systemic or intrathecal injection of ondansetron significantly prevented and reversed OIH, but not local intraplantar injection; (2) systemic or intrathecal injection of ondansetron prevented and reversed tolerance; and (3) ondansetron blocked morphine-induced increases of multiple genes relevant to OIH and tolerance in dorsal root ganglion and spinal cord.

Conclusions

Morphine acts via a 5-HT3-dependent mechanism to support multiple maladaptations to the chronic administration of morphine. Furthermore, the use of 5-HT3 receptor antagonists may provide a new avenue to prevent or reverse OIH and tolerance associated with chronic opioid use.
Dome-shaped functional response induced by nutrient imbalance of the prey
Authors: Bressendorff Berith B. , Toft Søren
Published: March 2011

Nutritional ecological theory predicts that predators should adjust prey capture and consumption rates depending on the prey's nutritional composition. This would affect the predator's functional response, at least at high prey densities, i.e. near predator satiation. Using a simple fruitfly-wolf spider laboratory system in Petri dishes, we found that functional responses changed from day to day over a 7 day period. After 1 to 2 days of feeding, dome-shaped functional responses (i.e. reduced predation at highest prey densities) appeared in spiders fed nutritionally imbalanced prey, compared with steadily increasing or asymptotic functional responses with nutritionally near-optimal prey. Later again (days 5–7), the difference disappeared as the level of the functional response was reduced in both treatments. Experiments with adult females in spring and subadult spiders in autumn revealed opposite patterns: a dome-shaped response with high-lipid prey for reproductive females, for which protein-rich prey are optimal, and a dome-shaped (or simply reduced) response with high-protein prey for pre-winter subadults, for which high-lipid flies are the optimal prey. Our results have implications for predation theory and models of biological control that have, so far, neglected nutritional aspects; in particular, the dynamic nutritional state of the predators should be incorporated.
An investigation into the feasibility of internal strain measurement in solids by correlation of ultrasonic images
Authors: Bowler A. I. , Drinkwater B. W. , Wilcox P. D.
Published: March 2011

This paper investigates the feasibility of an ultrasonic method for measuring internal displacements and strains in engineering components at depths of tens of millimetres. The principle is to use an ultrasonic array to generate images of the speckle pattern produced by the material microstructure before and after the application of load. Under the assumption of constant ultrasonic velocity, a block-matching method is used to find the relative displacement of small portions of the images between the two loading states, and hence the strain. Experiments performed using a 5 MHz ultrasonic array show that good displacement measurement results are obtained from the speckle directly below the array at depths of up to 45 mm. The results demonstrate that the technique can be used to identify the onset of plasticity and non-uniformity in strain across the field of view. However, while the actual values of strain obtained are correct in some directions, they are systematically incorrect in other directions by a factor between five and six. It is shown that this is because the change in ultrasonic velocity owing to load (the acousto-elastic effect) has, in some cases, a more significant effect on ultrasonic propagation time than the change in distance owing to strain.
The number and types of all possible rotational symmetries for flexoelectric tensors
Authors: Le Quang H. , He Q.-C.
Published: March 2011

Flexoelectricity is due to the electric polarization generated by a non-zero strain gradient in a dielectric material without or with centrosymmetric microstructure. It is characterized by a fourth-order tensor, referred to as flexoelectric tensor, which relates the electric polarization vector to the gradient of the second-order strain tensor. This paper solves the fundamental problem of determining the number and types of all possible rotational symmetries for flexoelectric tensors and specifies the number of independent material parameters contained in a flexoelectric tensor belonging to a given symmetry class. These results are useful and even indispensable for experimentally identifying or theoretically/numerically estimating the flexoelectric coefficients of a dielectric material.
Variational estimates for the effective response and field statistics in thermoelastic composites with intra-phase property fluctuations
Authors: Lahellec Noël , Castañeda Pedro Ponte , Suquet Pierre
Published: March 2011

In this work, variational estimates are provided for the macroscopic response, as well as for the first and second moments of the stress and strain fields, in thermoelastic composites with non-uniform distributions of the thermal stress and elastic moduli in the constituent phases. These estimates are obtained in terms of a ‘comparison composite’ with uniform phase properties depending on the first and second moments of a certain combination of the given intra-phase thermal stresses and modulus field distributions. Under certain hypotheses, these estimates can be shown to lead to upper and lower bounds for the free energy of the composite, which reduce to standard results when the intra-phase fluctuations vanish. An illustrative application is given for rigidly reinforced composites with a non-uniform distribution of the thermal stress in the matrix phase.
Dragonfly cyclovirus, a novel single-stranded DNA virus discovered in dragonflies (Odonata: Anisoptera)
Authors: Rosario Karyna , Marinov Milen , Stainton Daisy , Kraberger Simona , Wiltshire Elizabeth J. , Collings David A. , Walters Matthew , Martin Darren P. , Breitbart Mya , Varsani Arvind
Published: March 2011

Dragonfly cyclovirus (DfCyV), a new species of ssDNA virus discovered using viral metagenomics in dragonflies (family Libellulidae) from the Kingdom of Tonga. Metagenomic sequences of DfCyV were similar to viruses of the recently proposed genus Cyclovirus within the family Circoviridae. Specific PCRs resulted in the recovery of 21 DfCyV genomes from three dragonfly species (Pantala flavescens, Tholymis tillarga and Diplacodes bipunctata). The 1741 nt DfCyV genomes share >95 % nucleotide identity and are classified into 11 subtypes representing a single strain. The DfCyV genomes share 48–63 % genome-wide nucleotide identity with cycloviruses identified in human faecal samples. Recombination analysis revealed three recombinant DfCyV genomes, suggesting that recombination plays an important role in cyclovirus evolution. To our knowledge, this is the first report of a circular ssDNA virus identified in insects, and the data may help elucidate evolutionary links among novel Circoviridae recently identified in animals and environmental samples.
Characterization of influenza A viruses isolated from wild waterfowl in Zambia
Authors: Simulundu Edgar , Ishii Akihiro , Igarashi Manabu , Mweene Aaron S. , Suzuki Yuka , Hang’ombe Bernard M. , Namangala Boniface , Moonga Ladslav , Manzoor Rashid , Ito Kimihito , Nakamura Ichiro , Sawa Hirofumi , Sugimoto Chihiro , Kida Hiroshi , Simukonda Chuma , Chansa Wilbroad , Chulu Jack , Takada Ayato
Published: March 2011

Although the quest to clarify the role of wild birds in the spread of the highly pathogenic H5N1 avian influenza virus (AIV) has yielded considerable data on AIVs in wild birds worldwide, information regarding the ecology and epidemiology of AIVs in African wild birds is still very limited. During AIV surveillance in Zambia (2008–2009), 12 viruses of distinct subtypes (H3N8, H4N6, H6N2, H9N1 and H11N9) were isolated from wild waterfowl. Phylogenetic analyses demonstrated that all the isolates were of the Eurasian lineage. Whilst some genes were closely related to those of AIVs isolated from wild and domestic birds in South Africa, intimating possible AIV exchange between wild birds and poultry in southern Africa, some gene segments were closely related to those of AIVs isolated in Europe and Asia, thus confirming the inter-regional AIV gene flow among these continents. Analysis of the deduced amino acid sequences of internal proteins revealed that several isolates harboured particular residues predominantly observed in human influenza viruses. Interestingly, the isolates with human-associated residues exhibited higher levels of virus replication in the lungs of infected mice and caused more morbidity as measured by weight loss than an isolate lacking such residues. This study stresses the need for continued monitoring of AIVs in wild and domestic birds in southern Africa to gain a better understanding of the emergence of strains with the potential to infect mammals.
Core promoter T-blocks correlate with gene expression levels in C. elegans
Authors: Grishkevich Vladislav , Hashimshony Tamar , Yanai Itai
Published: March 2011

Core promoters mediate transcription initiation by the integration of diverse regulatory signals encoded in the proximal promoter and enhancers. It has been suggested that genes under simple regulation may have low-complexity permissive promoters. For these genes, the core promoter may serve as the principal regulatory element; however, the mechanism by which this occurs is unclear. We report here a periodic poly-thymine motif, which we term T-blocks, enriched in occurrences within core promoter forward strands in Caenorhabditis elegans. An increasing number of T-blocks on either strand is associated with increasing nucleosome eviction. Strikingly, only forward strand T-blocks are correlated with expression levels, whereby genes with ≥6 T-blocks have fivefold higher expression levels than genes with ≤3 T-blocks. We further demonstrate that differences in T-block numbers between strains predictably affect expression levels of orthologs. Highly expressed genes and genes in operons tend to have a large number of T-blocks, as well as the previously characterized SL1 motif involved in trans-splicing. The presence of T-blocks thus correlates with low nucleosome occupancy and the precision of a trans-splicing motif, suggesting its role at both the DNA and RNA levels. Collectively, our results suggest that core promoters may tune gene expression levels through the occurrences of T-blocks, independently of the spatio-temporal regulation mediated by the proximal promoter.
Recording Sound-Evoked Potentials from the Drosophila Antennal Nerve: Figure 1.
Authors: Eberl Daniel F. , Kernan Maurice J.
Published: March 2011

INTRODUCTION

Information about an animal's social and ecological environment takes many forms, several of which can be sensed as mechanical signals. The mechanosensory world of a fly such as Drosophila melanogaster is especially complex, and the transduction of signals involves a diverse set of specialized sense organs. Near-field sounds, such as the male courtship song, are transduced by sensory units in Johnston's organ (JO), which is the chordotonal organ in the Drosophila antennae. This article describes a protocol for recording extracellular potentials in the antennal nerve that occur in response to near-field acoustic signals generated electronically to mimic courtship songs. These recordings represent the combined action potentials of many or perhaps even all of the responding JO sensory neurons whose axons project along the antennal nerve en route to the antennal mechanosensory and motor center (AMMC).
Preparation of Meiotic Chromosomes from Larval and Pupal Drosophila Testes
Authors: Bonaccorsi Silvia , Giansanti Maria G. , Cenci Giovanni , Gatti Maurizio
Published: March 2011

INTRODUCTION

Several techniques have been developed for the preparation of Drosophila male meiotic chromosomes. All of these techniques allow a clear visualization of chromosomes, but not of other cellular structures such as the cytoskeleton and the spindle. This protocol describes two methods for preparation of meiotic chromosomes from larval and pupal testes. The first is a very simple method for preparing aceto-orcein-stained chromosomes. The second allows preparation of unstained chromosomes that can subsequently be stained with various dyes such as Giemsa, Hoechst 33258, and DAPI, or processed for in situ hybridization.
Micropatterning Cell-Substrate Adhesions Using Linear Polyacrylamide as the Blocking Agent
Authors: Guo Wei-hui , Wang Yu-li
Published: March 2011

INTRODUCTION

Recent developments in micropatterning techniques have facilitated systematic investigations of how cells respond to geometric cues, which likely have an important role in many physiological processes, such as growth and differentiation. Micropatterned substrates also offer technical advantages for cell biological studies by normalizing cell shapes and reducing the variability among cultured cells. In this article, we present a simple, economical micropatterning method that may be easily implemented in most laboratories. We also describe how to treat the substrate with linear polyacrylamide (PAA) to inhibit unwanted cell adhesion. First, glass coverslip surfaces are activated with 3-methacryloxypropyltrimethoxysilane (bind-silane), an approach that was originally used for covalently linking PAA gels to glass plates for SDS-PAGE to prevent gels from shrinking and swelling during staining/destaining. The activated surfaces are then coated with the photoresist SPR-220, exposed to ultraviolet (UV) light through a photomask, and developed to selectively remove UV-exposed photoresist. Finally, linear PAA is grafted onto the exposed areas of the bind-silane substrate (to prevent cell adhesion), and the remaining photoresist is removed to uncover the glass surface, making the unexposed areas available as adhesive areas for cell culture.
Dendrimer-Mediated Transfection
Authors: Dean David A. , Gasiorowski Joshua Z.
Published: March 2011

INTRODUCTION

The efficient delivery of exogenous DNA to cells for expression and function studies is an essential technique of modern cell biology. Polymer-based systems can be used to transfect cells, some of which rely on one type of molecule, whereas others contain a mixture of polymers and lipids. Reagents such as SuperFect or PolyFect use activated dendrimers, which are positively charged and resemble snowflakes in structure. One advantage of using dendrimer-based reagents is that they appear to be less sensitive than liposomal reagents to the presence of serum during transfection. Thus, they could be a better choice for cells that show greater dependence on the continual presence of serum (to avoid initiation of stress responses or induction of differentiation). This protocol describes a procedure for dendrimer-mediated transfection.
Preparing Injection Pipettes on a Flaming/Brown Pipette Puller
Authors: Dean David A. , Gasiorowski Joshua Z.
Published: March 2011

INTRODUCTION

The efficient delivery of exogenous DNA to cells for expression and function studies is an essential technique of modern cell biology, and direct delivery of genetic material by microinjection remains a reliable means of transfection. Needles for microinjection can either be pulled from glass capillaries on a pipette puller or can be purchased premade. When pulling needles, variables such as filament design, heat, pull strength (tension), and delay time between heating and pulling must be addressed. The heat setting affects the length and the tip size of the needle; high heat will typically produce longer needles and finer tips. The pull strength will also affect length and tip size, with greater pull strength producing longer tapered needles with finer tips. Finally, shorter delay times between heating and pulling can result in longer tapers and finer needles. However, if the delay is too short, the glass forms fibers resembling glass wool instead of usable needles. The advantage of pulling needles in the laboratory is that a variety of different needle types can be pulled, depending on the samples and the cells being injected. For laboratories performing even a moderate number of microinjection experiments, a Flaming/Brown-style pipette puller such as the Sutter Instruments P-97 is a cost-effective choice for manufacturing quality micropipettes quickly and reproducibly.