bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrition-related health management in a Bangladeshi community
Authors: Grace Clare
Published: December 2010

The British Bangladeshi community is one of the youngest and fastest growing ethnic minority groups in the UK. Many report poor socio-economic and health profiles with the existence of substantial health inequalities, particularly in relation to type 2 diabetes. Although there is compelling evidence for the effectiveness of lifestyle interventions in the prevention of type 2 diabetes, there is little understanding of how best to tailor treatments to the needs of minority ethnic groups. Little is known about nutrition related lifestyle choices in the Bangladeshi community or the factors influencing such decisions. Only by exploring these factors will it be possible to design and tailor interventions appropriately. The Bangladeshi Initiative for the Prevention of Diabetes study explored lay beliefs and attitudes, religious teachings and professional perspectives in relation to diabetes prevention in the Bangladeshi community in Tower Hamlets, London. Contrary to the views of health professionals and previous research, poor knowledge was not the main barrier to healthy lifestyle choices. Rather the desire to comply with cultural norms, particularly those relating to hospitality, conflicted with efforts to implement healthy behaviours. Considerable support from Islamic teachings for diabetes prevention messages was provided by religious leaders, and faith may have an important role in supporting health promotion in this community. Some health professionals expressed outdated views on community attitudes and were concerned about their own limited cultural understanding. The potential for collaborative working between health educators and religious leaders should be explored further, and the cultural competence of health professionals addressed.
Reduction of first-year survival threatens the viability of the Mariana CrowCorvus kubaryipopulation on Rota, CNMI
Authors: HA JAMES C. , BUTLER ALYSSA , ROBINETTE HA RENEE
Published: December 2010

The Mariana CrowCorvus kubaryiis a species of forest crow originally found only on the adjacent islands of Guam and Rota in the Mariana Islands of the western Pacific Ocean. Rapid and continuing declines led to it being listed by IUCN as "Critically Endangered" in 2008. Using 97 birds marked and resighted over the course of a 21 year period, we showed there was a rapid decline in first-year (fledgling to one year old) survival from 0.7 to 0.4 between 1990 and 2010, representing a doubling in mortality, and a smaller reduction in adult survival from 0.86 to 0.82 over the same period. A population model based on Leslie matrices incorporated the effects of catastrophic events, such as typhoons and human nest removal for captive breeding. All simulations predicted a precipitous decline in future populations and the inclusion of nest removals only shortened the life of the wild population by a few years. Identifying the underlying processes behind the decline in survival is the key research priority and, given the inevitable likelihood of a continuing rapid decline, conservation action should focus on securing the future of the species through captive breeding or captive rearing of wild-born chicks and ensuring that an adaptive management conservation programme is focused on countering the factors (e.g. predation) that are currently thought to impact first-year survival and productivity. Future research may identify other causes behind the Mariana Crow's decline and the conservation programme should be flexible enough to adapt to changing needs.
Consumer Society – RIP. A Comment
Authors: TRENTMANN FRANK
Published: December 2010

Andreas Wirsching has written an ambitious paper about the rise of the ‘consumer society’ in the twentieth century and its implications for historical research. I should say at the outset that I am sympathetic to his warnings against a Whig history. The career of the ‘consumer society’ needs to be historicised. My main problem is that ‘the consumer society’ is used in multiple, slippery ways in this article which moves back and forth between treating it as an ideological construct, an analytical concept and as a material reality of how people live their lives. It sometimes appears as ‘paradigm’, yet at other times it is the real thing, ‘a burgeoning consumer society’.
Reply to Frank Trentmann's comment: Consumer Society – RIP
Authors: WIRSCHING ANDREAS
Published: December 2010

Frank Trentmann is not very happy with my article, for the following three main reasons: First: the term ‘consumer society’ is applied too extensively and is not sufficiently defined. Second, my parameters of space and time are unclear, with the result that I neglect the differences in consumption and ‘consumer society’ in different parts of the world and at different periods. Furthermore, I do not establish a clear chronology with respect to the historical relationship between work and consumption. On this basis, third, Trentmann remains unconvinced by my critical remarks on the problems of individuality, citizenship and the pitfalls of historical teleology.
China, the EU, and the New Multipolarity
Authors: Geeraerts Gustaaf
Published: December 2010

The world within which the EU and China have to deal with each other is changing. The unipolar moment is definitely fading and slowly giving way to an international system characterized by multilayered and culturally diversified polarity. This development has far-reaching consequences for the EU–China relationship; the more so since the EU and China have distinctive identities and define their value preferences differently. China is no longer the developing country it once was and is becoming more assertive by the day. Beijing is at the head of the world’s most successful economy and will weigh more and more heavily on global governance.1 Three decades of impressive economic growth have boosted the self-confidence of the Chinese leaders significantly. In Beijing, the notion that China should start taking on an attitude befitting a great power is gaining ground. China is taking up ever more space within various multilateral organizations and is setting up diplomatic activities throughout the globe. Moreover, Beijing has become more active in setting up its own multilateral channels to further its national interests and own norms. China no longer considers itself an outsider that should crawl back into its shell and steer clear of a global political system dominated by the West. All this puts into question the EU’s conditional policy towards China, which is based on the assumption that China can be socialized and persuaded to incorporate Europe’s post-modern values. The way ahead seems to be for Europe to opt for a more pragmatic approach, which takes stock of the changes in the underlying power and identity relations between the EU and China. The analysis of this paper will be developed at three levels. First, it examines the changes in the structure of international politics. To what kind of structure are we evolving and where do China and the EU fit in? Second, it takes a closer look at the respective identities of China and the EU and explicates the major differences between them. Finally, this study appraises the implications of the emerging multilayered and culturally diversified polarity for the further development of the EU–China relationship.
Neo-liberalism at a Time of Crisis: the Case of Taxation
Authors: Lesage Dries , Vermeiren Mattias
Published: December 2010

This essay explores how the global financial crisis of 2008–2009 has affected the stability of what Stephen Gill has termed the ‘new constitutionalism of disciplinary neo-liberalism’,1more precisely, in the realm of international tax policy. Rather than providing an in-depth and complete empirical study of the matter, this essay will highlight certain interesting developments and touch upon a series of possibly relevant questions that could form the basis for a future research agenda. In the first section, we will examine the remarkable strength and resilience of the new constitutionalism as the institutional component of neo-liberal hegemony. Then we will proceed to an exploration of the impact of the crisis on this hegemony, also paying attention to deepening geopolitical multipolarity as an additional variable. The final, more empirical section will investigate the case of international taxation in this context, and demonstrate that new constitutionalism remains a crucial supporting pillar of neo-liberal globalisation.
Thermal regime of the Costa Rican convergent margin: 1. Along‐strike variations in heat flow from probe measurements and estimated from bottom‐simulating reflectors
Authors: Harris Robert N. , Grevemeyer Ingo , Ranero César R. , Villinger Heinrich , Barckhausen Udo , Henke Thomas , Mueller Christian , Neben Soenke
Published: December 2010

The thermal structure of convergent margins provides information related to the tectonics, geodynamics, metamorphism, and fluid flow of active plate boundaries. We report 176 heat flow measurements made with a violin bow style probe across the Costa Rican margin at the Middle America Trench. The probe measurements are collocated with seismic reflection lines. These seismic reflection lines show widespread distribution of bottom‐simulating reflectors (BSRs). To extend the spatial coverage of heat flow measurements we estimate heat flow from the depth of BSRs. Comparisons between probe measurements and BSR‐derived estimates of heat flow are generally within 10% and improve with distance landward of the deformation front. Together, these determinations provide new information on the thermal regime of this margin. Consistent with previous studies, the margin associated with the northern Nicoya Peninsula is remarkably cool. We define better the southern boundary of the cool region. The northern extent of the cool region remains poorly determined. A regional trend of decreasing heat flow landward of the deformation front is apparent, consistent with the downward advection of heat by the subducting Cocos Plate. High wave number variability at a scale of 5–10 km is significantly greater than the measurement uncertainty and is greater south of the northern Nicoya Peninsula. These heat flow anomalies vary between approximately 20 and 60 mW m−2 and are most likely due to localized fluid flow through mounds and faults on the margin. Simple one‐dimensional models show that these anomalies are consistent with flow rates of 7–15 mm yr−1. Across the margin toe variability is significant and likely due to fluid flow through deformation structures associated with the frontal sedimentary prism.
Impact of the Northern Hemisphere extratropics on the skill in predicting the Madden Julian Oscillation
Authors: Vitart F. , Jung T.
Published: December 2010

Using a series of relaxation hindcast experiments, this paper shows that the northern extratropics have a significant impact on the skill of the ECMWF forecast system in predicting the Madden Julian Oscillation (MJO) during boreal winter. The westerly wind burst associated with the March 1997 MJO event is a high‐profile example of an event that was influenced by extratropical circulation anomalies. The propagation speed of MJO events is overall improved when the northern extratropics are relaxed towards analysis fields. Additional experiments in which the relaxation is confined to different areas of the Northern Hemisphere extratropics suggest that it is atmospheric circulation anomalies in the North Pacific region which most strongly affect the skill in predicting the MJO.
Precipitating cloud‐system response to aerosol perturbations
Authors: Lee Seoung‐Soo , Feingold Graham
Published: December 2010

We simulate aerosol effects on a Tropical Western Pacific mixed‐phase convective cloud system of two‐day duration that is well constrained by observations. This facilitates exploration of aerosol‐induced changes in precipitation pathways. A 10‐fold increase in aerosol produces a small (9%) increase in the simulated precipitation due to an enhancement in convective rain countering a reduction in stratiform rain. A more distinct feature is that in stratiform clouds, precipitation efficiency PE and scavenging efficiency SE decrease significantly with increasing aerosol. There is very close agreement between PE and SE both temporally and for stratiform vs. convective rain. The time required for the perturbed system to relax back to the unperturbed aerosol state is ∼10 days, with only weak sensitivity to the magnitude of the aerosol perturbation and the modeled increase (or decrease) in precipitation. The upper tropospheric relaxation time is substantially longer, with implications for direct forcing and heterogeneous chemistry.
An observational study of turbulence inside a closed basin
Authors: Fu Peijian , Zhong Shiyuan , Whiteman C. David , Horst Tom , Bian Xindi
Published: December 2010

Data from a flux tower on the floor of Arizona's Meteor Crater are compared to data on the plain outside the crater to determine the impact of basin topography on surface‐layer mean and turbulence properties, focusing particularly on windy periods. The bowl‐shaped crater amplifies the diurnal oscillations of temperature and heat fluxes, with the amplification most pronounced under quiescent synoptic conditions. The crater's rim shelters the crater atmosphere from mean background flows so that wind speeds inside the crater are usually less than half the speeds on the outside plain. But flows in the crater are much more turbulent, with turbulence presumably generated by the conversion of mean flow into turbulent motion. On days with near‐surface winds outside the crater greater than 10 m s−1, turbulent kinetic energy can reach extremely large values (∼15 m2 s−2) inside the crater. Compared to the velocity and temperature spectra outside, spectral peaks occur at lower frequencies inside the crater, especially for the cross‐stream wind component. The surface layer is very shallow (<2 m) on the crater floor, suggesting that the similarity theory‐based empirical formulas may not be useful for describing properties of the flow at that location.
Reanalysis of the Viking results suggests perchlorate and organics at midlatitudes on Mars
Authors: Navarro‐González Rafael , Vargas Edgar , de la Rosa José , Raga Alejandro C. , McKay Christopher P.
Published: December 2010

The most comprehensive search for organics in the Martian soil was performed by the Viking Landers. Martian soil was subjected to a thermal volatilization process to vaporize and break organic molecules, and the resultant gases and volatiles were analyzed by gas chromatography‐mass spectrometry. Only water at 0.1–1.0 wt% was detected, with traces of chloromethane at 15 ppb, at Viking landing site 1, and water at 0.05–1.0 wt% and carbon dioxide at 50–700 ppm, with traces of dichloromethane at 0.04–40 ppb, at Viking landing site 2. These chlorohydrocarbons were considered to be terrestrial contaminants, although they had not been detected at those levels in the blank runs. Recently, perchlorate was discovered in the Martian Arctic soil by the Phoenix Lander. Here we show that when Mars‐like soils from the Atacama Desert containing 32 ± 6 ppm of organic carbon are mixed with 1 wt% magnesium perchlorate and heated, nearly all the organics present are decomposed to water and carbon dioxide, but a small amount is chlorinated, forming 1.6 ppm of chloromethane and 0.02 ppm of dichloromethane at 500°C. A chemical kinetics model was developed to predict the degree of oxidation and chlorination of organics in the Viking oven. Reinterpretation of the Viking results therefore suggests ≤0.1% perchlorate and 1.5–6.5 ppm organic carbon at landing site 1 and ≤0.1% perchlorate and 0.7–2.6 ppm organic carbon at landing site 2. The detection of organics on Mars is important to assess locations for future experiments to detect life itself.
DARC and D6: silent partners in chemokine regulation?
Authors: Hansell Chris A H , Hurson Catherine E , Nibbs Robert J B
Published: December 2010

Chemokine receptors adorn the surface of leukocytes and other cell types ready to translate the extracellular chemokine environment into functional cellular outcomes. However, there are several molecules that, in many respects, look like chemokine receptors, but which do not have the ability to confer chemotactic potential to cell lines. This apparent silence spurred the search for signalling‐independent functions and led to the development of new paradigms of chemokine regulation. In this review, we summarise the experimental basis for these ideas focussing on DARC and D6, the most studied members of this group of molecules. We discuss data generated using in vitro systems and genetically deficient mice, include results from observational human studies, and summarise the key findings of recent research. We take a critical look at current models of in vivo function highlighting important gaps in our knowledge and demonstrating that there is still much to find out about these enigmatic molecules.
Where is the ‘Jennifer Aniston neuron’?
Authors: Aur Dorian
Published: December 2010

It is generally believed that spike timing features (firing rate, ISI) are the main characteristics that can be related to neural code. Contrary to this common belief, spike directivity, a new measure that quantifies transient charge density dynamics within action potentials (APs) provides better results in discriminating different categories of visual object recognition. Specifically, intracranial recordings from medial temporal lobe (MTL) of epileptic patients have been analyzed using firing rate, interspike intervals and spike directivity. A comparative statistical analysis of the same spikes from four selected neurons shows that electrical micro-mapped features in neurons display higher separability to input images compared to spike timing features. If the observation vector include data from all 4 neurons then the comparative analysis shows a highly significant separation between categories for spike directivity (p=0.0023) and does not display separability for ISI (p=0.3768) and firing rate (p=0.5492). The presence of electrical micro-maps within APs suggests the existence of an intrinsic “neural code" where information regarding input images is electrically written/coded and read/decoded during AP propagation in the neuron. The occurrence of electrical micro-maps within APs reflects information communication and computation in analyzed neuron within a millisecond-level time domain of AP occurrence. This existence of a “lower level” of coding where information is processed within neurons raises questions regarding the richness and reliability of models that constrain neural code to spike timing features. Additionally, this phenomenon that occurs within APs may provide a step forward in understanding the fundamental gap between molecular description, information processing and neuronal function. Importantly, this paper confirms a new paradigm regarding neural code where information processing, computation and memory formation in the brain can be explained in terms of dynamics and interaction of electric charges.
Argudas: arguing with gene expression information
Authors: McLeod Kenneth
Published: December 2010

In situ hybridization gene expression information helps biologists identify where a gene is expressed. However, the databases that republish the experimental information are often both incomplete and inconsistent. This presentation examines a system, Argudas, designed to help tackle these issues. Argudas is an evolution of an existing system, and so that system is reviewed as a means of both explaining and justifying the behavior of Argudas. Throughout the discussion of Argudas a number of issues will be raised including the appropriateness of argumentation in biology and the challenges faced when integrating apparently similar online biological databases.
Active scaffolds for on-demand drug and cell delivery
Authors: Zhao Xuanhe , Kim Jaeyun , Cezar Christine A. , Huebsch Nathaniel , Lee Kangwon , Bouhadir Kamal , Mooney David J.
Published: December 2010

Porous biomaterials have been widely used as scaffolds in tissue engineering and cell-based therapies. The release of biological agents from conventional porous scaffolds is typically governed by molecular diffusion, material degradation, and cell migration, which do not allow for dynamic external regulation. We present a new active porous scaffold that can be remotely controlled by a magnetic field to deliver various biological agents on demand. The active porous scaffold, in the form of a macroporous ferrogel, gives a large deformation and volume change of over 70% under a moderate magnetic field. The deformation and volume variation allows a new mechanism to trigger and enhance the release of various drugs including mitoxantrone, plasmid DNA, and a chemokine from the scaffold. The porous scaffold can also act as a depot of various cells, whose release can be controlled by external magnetic fields.
Causal inference methods to study nonrandomized, preexisting development interventions
Authors: Arnold Benjamin F. , Khush Ranjiv S. , Ramaswamy Padmavathi , London Alicia G. , Rajkumar Paramasivan , Ramaprabha Prabhakar , Durairaj Natesan , Hubbard Alan E. , Balakrishnan Kalpana , Colford John M.
Published: December 2010

Empirical measurement of interventions to address significant global health and development problems is necessary to ensure that resources are applied appropriately. Such intervention programs are often deployed at the group or community level. The gold standard design to measure the effectiveness of community-level interventions is the community-randomized trial, but the conditions of these trials often make it difficult to assess their external validity and sustainability. The sheer number of community interventions, relative to randomized studies, speaks to a need for rigorous observational methods to measure their impact. In this article, we use the potential outcomes model for causal inference to motivate a matched cohort design to study the impact and sustainability of nonrandomized, preexisting interventions. We illustrate the method using a sanitation mobilization, water supply, and hygiene intervention in rural India. In a matched sample of 25 villages, we enrolled 1,284 children <5 y old and measured outcomes over 12 mo. Although we found a 33 percentage point difference in new toilet construction [95% confidence interval (CI) = 28%, 39%], we found no impacts on height-for-ageZscores (adjusted difference = 0.01, 95% CI = −0.15, 0.19) or diarrhea (adjusted longitudinal prevalence difference = 0.003, 95% CI = −0.001, 0.008) among children <5 y old. This study demonstrates that matched cohort designs can estimate impacts from nonrandomized, preexisting interventions that are used widely in development efforts. Interpreting the impacts as causal, however, requires stronger assumptions than prospective, randomized studies.
Spatial restriction of receptor tyrosine kinase activity through a polarized endocytic cycle controls border cell migration
Authors: Assaker Gloria , Ramel Damien , Wculek Stefanie K. , González-Gaitán Marcos , Emery Gregory
Published: December 2010

Border cell migration is a stereotyped migration occurring during the development of the
Drosophila
egg chamber. During this process, a cluster composed of six to eight follicle cells migrates between nurse cells toward the oocyte. Receptor tyrosine kinases (RTKs) are enriched at the leading edge of the follicle cells and establish the directionality of their migration. Endocytosis has been shown to play a role in the maintenance of this polarization; however, the mechanisms involved are largely unknown. In this study, we show that border cell migration requires the function of the small GTPases Rab5 and Rab11 that regulate trafficking through the early and the recycling endosome, respectively. Expression of a dominant negative form of
rab11
induces a loss of the polarization of RTK activity, which correlates with a severe migration phenotype. In addition, we demonstrate that the exocyst component Sec15 is distributed in structures that are polarized during the migration process in a Rab11-dependent manner and that the down-regulation of different subunits of the exocyst also affects migration. Together, our data demonstrate a fundamental role for a plasma membrane–endosome trafficking cycle in the maintenance of active RTK at the leading edge of border cells during their migration.
Differential dynamics and activity-dependent regulation of α- and β-neurexins at developing GABAergic synapses
Authors: Fu Yu , Huang Z. Josh
Published: December 2010

Neurexins (NRXs) and neuroligins are key synaptic adhesion molecules that also recruit synaptic signaling machineries. Neurexins consist of α- and β-isoforms, but how they couple synaptic transmission and adhesion to regulate activity-dependent synapse development remains unclear, in part because of poor understanding of their cell biology and regulation in the relevant neurons. Here, we examined the subaxonal localization, dynamics, and regulation of NRX1α and NRX1β in cortical perisomatic inhibitory synapses. Both isoforms are delivered to presynaptic terminals but show significant and different turnover rate at the membrane. Although NRX1α is highly diffuse along developing axons and filopodia, NRX1β is strictly anchored at terminals through binding to postsynaptic ligands. The turnover rate of NRX1β is attenuated by neural activity and presynaptic GABA
B
receptors. NRXs, thus, are intrinsically dynamic but are stabilized by local transmitter release. Such an activity-adjusted adhesion system seems ideally suited to rapidly explore and validate synaptic partners guided by synaptic transmission.
Rapid landscape transformation in South Island, New Zealand, following initial Polynesian settlement
Authors: McWethy David B. , Whitlock Cathy , Wilmshurst Janet M. , McGlone Matt S. , Fromont Mairie , Li Xun , Dieffenbacher-Krall Ann , Hobbs William O. , Fritz Sherilyn C. , Cook Edward R.
Published: December 2010

Humans have altered natural patterns of fire for millennia, but the impact of human-set fires is thought to have been slight in wet closed-canopy forests. In the South Island of New Zealand, Polynesians (Māori), who arrived 700–800 calibrated years (cal y) ago, and then Europeans, who settled ∼150 cal y ago, used fire as a tool for forest clearance, but the structure and environmental consequences of these fires are poorly understood. High-resolution charcoal and pollen records from 16 lakes were analyzed to reconstruct the fire and vegetation history of the last 1,000 y. Diatom, chironomid, and element concentration data were examined to identify disturbance-related limnobiotic and biogeochemical changes within burned watersheds. At most sites, several high-severity fire events occurred within the first two centuries of Māori arrival and were often accompanied by a transformation in vegetation, slope stability, and lake chemistry. Proxies of past climate suggest that human activity alone, rather than unusually dry or warm conditions, was responsible for this increased fire activity. The transformation of scrub to grassland by Europeans in the mid-19th century triggered further, sometimes severe, watershed change, through additional fires, erosion, and the introduction of nonnative plant species. Alteration of natural disturbance regimes had lasting impacts, primarily because native forests had little or no previous history of fire and little resilience to the severity of burning. Anthropogenic burning in New Zealand highlights the vulnerability of closed-canopy forests to novel disturbance regimes and suggests that similar settings may be less resilient to climate-induced changes in the future.
Structural space of protein–protein interfaces is degenerate, close to complete, and highly connected
Authors: Gao Mu , Skolnick Jeffrey
Published: December 2010

At the heart of protein–protein interactions are protein–protein interfaces where the direct physical interactions occur. By developing and applying an efficient structural alignment method, we study the structural similarity of representative protein–protein interfaces involving interactions between dimers. Even without structural similarity between individual monomers that form dimeric complexes, ∼90% of native interfaces have a close structural neighbor with similar backbone C

α

geometry and interfacial contact pattern. About 80% of the interfaces form a dense network, where any two interfaces are structurally related using a transitive set of at most seven intermediate interfaces. The degeneracy of interface space is largely due to the packing of compact, hydrogen-bonded secondary structure elements. This packing generates relatively flat interacting surfaces whose geometries are highly degenerate. Comparative study of artificial and native interfaces argues that the library of protein interfaces is close to complete and comprised of roughly 1,000 distinct interface types. In contrast, the number of possible quaternary structures of dimers is estimated to be about 10
4
times larger; thus, an experimentally determined database of all representative quaternary structures is not likely in the near future. Nevertheless, one could in principle exploit the completeness of protein interfaces to predict most dimeric quaternary structures. Finally, our results provide a structural explanation for the prevalence of promiscuous protein interactions. By side-chain packing adjustments, we illustrate how multiprotein specificity can be attained at a promiscuous interface.
Rapid DNA–protein cross-linking and strand scission by an abasic site in a nucleosome core particle
Authors: Sczepanski Jonathan T. , Wong Remus S. , McKnight Jeffrey N. , Bowman Gregory D. , Greenberg Marc M.
Published: December 2010

Apurinic/apyrimidinic (AP) sites are ubiquitous DNA lesions that are highly mutagenic and cytotoxic if not repaired. In addition, clusters of two or more abasic lesions within one to two turns of DNA, a hallmark of ionizing radiation, are repaired much less efficiently and thus present greater mutagenic potential. Abasic sites are chemically labile, but naked DNA containing them undergoes strand scission slowly with a half-life on the order of weeks. We find that independently generated AP sites within nucleosome core particles are highly destabilized, with strand scission occurring ∼60-fold more rapidly than in naked DNA. The majority of core particles containing single AP lesions accumulate DNA–protein cross-links, which persist following strand scission. The N-terminal region of histone protein H4 contributes significantly to DNA–protein cross-links and strand scission when AP sites are produced approximately 1.5 helical turns from the nucleosome dyad, which is a known hot spot for nucleosomal DNA damage. Reaction rates for AP sites at two positions within this region differ by ∼4-fold. However, the strand scission of the slowest reacting AP site is accelerated when it is part of a repair resistant bistranded lesion composed of two AP sites, resulting in rapid formation of double strand breaks in high yields. Multiple lysine residues within a single H4 protein catalyze double strand cleavage through a mechanism believed to involve a templating effect. These results show that AP sites within the nucleosome produce significant amounts of DNA–protein cross-links and generate double strand breaks, the most deleterious form of DNA damage.
Auxin transport through PIN-FORMED 3 (PIN3) controls shade avoidance and fitness during competition
Authors: Keuskamp Diederik H. , Pollmann Stephan , Voesenek Laurentius A. C. J. , Peeters Anton J. M. , Pierik Ronald
Published: December 2010

Plants grow in dense vegetations at the risk of being out-competed by neighbors. To increase their competitive power, plants display adaptive responses, such as rapid shoot elongation (shade avoidance) to consolidate light capture. These responses are induced upon detection of proximate neighbors through perception of the reduced ratio between red (R) and far-red (FR) light that is typical for dense vegetations. The plant hormone auxin is a central regulator of plant development and plasticity, but until now it has been unknown how auxin transport is controlled to regulate shade-avoidance responses. Here, we show that low R:FR detection changes the cellular location of the PIN-FORMED 3 (PIN3) protein, a regulator of auxin efflux, in
Arabidopsis
seedlings. As a result, auxin levels in the elongating hypocotyls are increased under low R:FR. Seedlings of the
pin3-3
mutant lack this low R:FR-induced increase of endogenous auxin in the hypocotyl and, accordingly, have no elongation response to low R:FR. We hypothesize that low R:FR-induced stimulation of auxin biosynthesis drives the regulation of PIN3, thus allowing shade avoidance to occur. The adaptive significance of PIN3-mediated control of shade-avoidance is shown in plant competition studies. It was found that
pin3
mutants are outcompeted by wild-type neighbors who suppress fitness of
pin3-3
by 40%. We conclude that low R:FR modulates the auxin distribution by a change in the cellular location of PIN3, and that this control can be of great importance for plants growing in dense vegetations.
Spatio-temporal sequence of cross-regulatory events in root meristem growth
Authors: Scacchi Emanuele , Salinas Paula , Gujas Bojan , Santuari Luca , Krogan Naden , Ragni Laura , Berleth Thomas , Hardtke Christian S.
Published: December 2010

A central question in developmental biology is how multicellular organisms coordinate cell division and differentiation to determine organ size. In Arabidopsis roots, this balance is controlled by cytokinin-induced expression of
SHORT HYPOCOTYL 2
(
SHY2
) in the so-called transition zone of the meristem, where SHY2 negatively regulates auxin response factors (ARFs) by protein–protein interaction. The resulting down-regulation of
PIN-FORMED
(
PIN
) auxin efflux carriers is considered the key event in promoting differentiation of meristematic cells. Here we show that this regulation involves additional, intermediary factors and is spatio-temporally constrained. We found that the described cytokinin–auxin crosstalk antagonizes
BREVIS RADIX
(
BRX
) activity in the developing protophloem.
BRX
is an auxin-responsive target of the prototypical ARF MONOPTEROS (MP), a key promoter of vascular development, and transiently enhances
PIN3
expression to promote meristem growth in young roots. At later stages, cytokinin induction of
SHY2
in the vascular transition zone restricts
BRX
expression to down-regulate
PIN3
and thus limit meristem growth. Interestingly, proper
SHY2
expression requires
BRX
, which could reflect feedback on the auxin responsiveness of
SHY2
because BRX protein can directly interact with MP, likely acting as a cofactor. Thus, cross-regulatory antagonism between
BRX
and
SHY2
could determine ARF activity in the protophloem. Our data suggest a model in which the regulatory interactions favor
BRX
expression in the early proximal meristem and
SHY2
prevails because of supplementary cytokinin induction in the later distal meristem. The complex equilibrium of this regulatory module might represent a universal switch in the transition toward differentiation in various developmental contexts.
Autoinhibition of DNA cleavage mediated by RAG1 and RAG2 is overcome by an epigenetic signal in V(D)J recombination
Authors: Grundy Gabrielle J. , Yang Wei , Gellert Martin
Published: December 2010

Gene assembly of the variable domain of antigen receptors is initiated by DNA cleavage by the RAG1–RAG2 protein complex at sites flanking V, D, and J gene segments. Double-strand breaks are produced via a single-strand nick that is converted to a hairpin end on coding DNA and a blunt end on the neighboring recombination signal sequence. We demonstrate that the C-terminal regions of purified murine RAG1 (aa 1009–1040) and RAG2 (aa 388–520, including a plant homeodomain [PHD domain]) collaborate to inhibit the hairpinning stage of DNA cleavage. The C-terminal region of RAG2 stabilizes the RAG1/2 heterotetramer but destabilizes the RAG–DNA precleavage complex. This destabilization is reversed by binding of the PHD domain to a histone H3 peptide trimethylated on lysine 4 (H3K4me3). The addition of H3K4me3 likewise alleviates the RAG1/RAG2 C-terminus-mediated inhibition of hairpinning and the PHD-mediated inhibition of transposition activity. Thus a negative regulatory function of the noncore regions of RAG1/2 limits the RAG endonuclease activity in the absence of an activating methylated histone tail bound to the complex.
Antigen-bearing dendritic cells regulate the diverse pattern of memory CD8 T-cell development in different tissues
Authors: Shen Ching-Hung , Talay Oezcan , Mahajan Vinay S. , Leskov Ilya B. , Eisen Herman N. , Chen Jianzhu
Published: December 2010

Memory T cells of the effector type (T
EM
) account for the characteristic rapidity of memory T-cell responses, whereas memory T cells of the central type (T
CM
) account for long-lasting, vigorously proliferating memory T-cell responses. How antigen-stimulated (primed) T cells develop into different memory T-cell subsets with diverse tissue distributions is largely unknown. Here we show that after respiratory tract infection of mice with influenza virus, viral antigen associated with dendritic cells (DCs) was abundant in lung-draining lymph nodes (DLN) and the spleen for more than a week but was scant and transient in nondraining lymph nodes (NDLN). Correspondingly, activated CD8 T cells proliferated extensively in DLN and the spleen but minimally in NDLN. Strikingly, however, although most persisting CD8 T cells in DLN and spleen exhibited the T
EM
phenotype, those persisting in NDLN exhibited the T
CM
phenotype. Reducing antigen exposure by depleting DCs at the peak of primary T-cell responses enhanced the development of T
CM
, whereas subjecting primed CD8 T cells from NDLN to additional antigen stimulation inhibited T
CM
development. These findings demonstrate that differences in persistence of antigen-bearing DCs in various tissues regulate the tissue-specific pattern of memory CD8 T-cell development. The findings have significant implications for design of vaccines and immunization strategies.
The Speech of Disadvantaged Dublin Children
Authors: Edwards John
Published: December 2010

La Parolkapablo de Malavantagigitaj Dublinaj Infanoj
La komunajo al la studoj pri malavantagigitaj infanoj estas la lingvo. Depost Labov (1969) oni akceptas, ke la parolo de tiaj infanoj diferencigas disde tiu de la mezklasaj infanoj. La lingvo mem ne estas mankhava, tamen socia malavantago ligigas al kelkaj formoj de parolo.
Programoj de kompensa (egaliga) edukado ofte provis sangi la lingvon al formo socie pli akceptebla. Antau ol entrepreni tion, oni havu informon pri la veraj trajtoj de la parolkapablo de la infanoj; tamen, tia informo nesufice disponigas.
Ankaŭ en la irlanda cefurbo Dublin (irlande: Baile Atha Cliath) gravas la lingva faktoro. La nuna studo provas kompari la parolon de dublinaj malavantagigitaj infanoj kun tiu de infanoj sen tia malavantago. Ni studas ne la rolon de tiu parolo en la propra grupo, sed la kaûzojn de malfacilo en la lernejo, en la vasta socio, kiun reprezentas la lernejo.
Oni komparis po dek knabojn de la kvina kaj de la dua lerneja jaroj el du apartaj lernejoj: unu trovigas en urbocentra zono kun malbona logigo, kun senlaboreco kaj malaltaj salajroj. Tie funkcias programo de porinfana kompensa edukado. La alia lernejo, en la norda Dublino, akceptas infanojn eljnezklasaj familioj kaj el familioj de fikse logantaj, fikse laborantaj laborist-klasanoj. Ciuj estis lernantoj de meza atingo. Oni klasigis la sociekonomian nivelon kaj grandecon de la familioj.
Oni kolektis specimenon de la parolo de ciu infano per la metodo de ripetado de rakonto. La esploristo rakontis rakonteton de 560 vortoj, pri kaptado de fisisto, kaj petis la infanon ripeti gin al li, kvazau en ludo. Oni emfazis la komunikadon, la intereson pri la enhavo (ne la formo) al la esploristo. Oni surbendigis la rerakonton kaj analizis gin rilate al vortostoko, longeco, rapideco, ktp.
Fine, kvin plenkreskuloj prijugis la specimenojn, pritaksante ilin lau inteligento, flueco, vortoprovizo, vockvalito kaj komunikpovo de la koncerna parolanto.
La rezultoj montris klaran preferon, flanke de la jugistoj, de la parolstilo de la infanoj sen malavantago, en ciuj rilatoj. Ankau la rapideco kaj sintaksa komplekseco de la parolstilo de la malavantagigitaj infanoj montris mankon kompare al la senmalavantagaj. Oni rimarku, tamen, ke temas pri eksperimento farita en la etoso de lernejo, kaj ke la rezultoj tie eble ne similas al tiuj atingotaj aliloke. Tamen, ni ja parolas ci tie pri la atingoj en la lernejo.
Versajnas, ke perceptoj pri la vockvalito, kiu inkluzivas la prononcon, la intonacion kaj la akcenton, influas al aliaj prijugoj. Jam ekzistas multaj studoj pri tio. Se oni komencas prijugi jam junajn infanojn tiumaniere, la profetado rapide realigas. Finfine, do, jen sociaj prijugoj kiuj respegulas la socian prijugon pri tiaj infanoj. Kaj rilate al tiuj tendencoj, programo de kompensa edukado volas helpi al ili. Sed, aliflanke, ni ekvidas, ke tia infano trovigas en malfacilo jam en la unua momenta, kiam li ekparolas en la lernejo, pro tuja prijugo, eble erara, pri sia generala inteligento au vortprovizo.
The Cornish Language and its Literature, P.B. Ellis; The Lion's Tongue K. MacKinnon; Culture in Crisis Betts, C.
Authors: Edwards John
Published: December 2010

La keltaj lingvoj suferas erozion favore al siaj pli fortaj najbaroj. Tamen vekigis intcrcso pri ilia estonteco. Ciu el la tri recenzataj verkoj estas la plej fresdata pri la koncerna lingvo. Sume, temas pri la tri keltaj lingvoj de la brita cefinsulo.
La temo de la verko de Ellis, la kornvala, kompreneble ne plu estas parola lingvo. La historio de la falo de la kornvala, do, estas pli-malpli finverkita, kaj socilingvisto povas multon lerni de gi. La kornvalanoj estis la unua kelta popolo konkerita de la angloj. Sekvis rapida disfalo de la lingvo. Jam en 1680 kornvalano unue deklaris deziron savi la lingvon. En la 18-a jc. filologoj ekstudis antikvajn tekstojn, sed ignoris la vivantajn parolantoj, la lasta el kiuj mortis en 1777.
line de la 19-a jc. okazis la t.n. Kelta Revivigo, kaj naskigis movado por la revivigo de la lingvo. Nuntempe, pli da homoj scipovas la kornvalan, ol en la antaŭaj ducent jaroj. Ekzistas Kornvala Lingvokomitato kaj aŭtonomisma politika partio.
La skotgaela ankaŭ frontas malfacilon, sed estas daŭre uzata de c. 80 000 parolantoj. La libro de MacKinnon montras, kiel la kelta lingvo cedis terenon al norda variajo de la lingvo angla — la lalansa - kiu ekde la 16-a jc. alprenis la nomon skota, dum la kelta nomigis 'irlanda." Tiel, la gaellingvanoj igis kvazaŭ fremduloj en sia propra lando.
Kiel en Irlando, la gaellingvaj regionoj de Skotlando fakte estas dulingvaj. La elenienta instruado estas en la gaela, sed ne la supera. Laŭ MacKinnon, eble la gaela ne formortos, se la parolantoj alte taksas gin. Sed la estonta pluvivo dependas de ekonomiaj fortoj - se la lingvo praktike utilas en sia natura medio.
La kimra, traktita en la libro de Betts, estas eble la plej forte ekzistanta kelta lingvo. Kiel ce la skotgaela, tre gravas la pluvivo de tiuj regionoj, kie la lingvo estas majoritata. Sed tie, anglalingvanoj acetadas dometojn kaj farmbicnojn. La kimra, historic, ne tiel disfalis, kiel la ceteraj keltlingvoj, parte car la kimra popolo akceptis la protestantismon kaj la kimra igis tiel kultlingvo. Inverse, la kornvalanoj retenis la katolikismon kaj perdis sian lingvon. Betts emfazas la gravecon de oficiala subteno, sed la amasa popolo finfine decidigas la estontecon de lingvo. Nur Betts, el la tri aŭtoroj, faras konkretan agad-proponon : la starigon de tri administraj regiono-tipoj; laŭ la koncerna lingva idento. Sed tio en si mem estas iusence atenco kontraŭ la 'natureco' de tia regiono. Paradoksa problemo. Dua problemo : la verkistoj alprcnis ne-dinamisman, do nerealecan starpunkton.
La verkoj de Ellis kaj MacKinnon estas sciencaj kaj legeblaj. Tiu de Betts, male, estas neunueca, car preparita por gazetoj. Oni povas legi la librojn kaj por gajni informon pri la koncernaj lingvoj, kaj pro generala socilingvistika intereso.
The Anglicization of Canada, 1971-1981
Authors: Castonguay Charles
Published: December 2010

RESUME
L'anglicisation du Canada, 1971-1981
Les données sur l'adoption de l'anglais comme principale langue d'usage à la maison, recueillies aux derniers recensements, font voir un accroissement général de cette forme d'anglicisation parmi les minorités linguistiques canadiennes entre 1971 et 1981, en particulier au sein de la population francophone à l'extérieur du Québec. Au Québec même, la supériorité du pouvoir d'assimilation de l'anglais en regard du français s'avère au moins aussi grande en 1981 qu'en 1971. Le conflit fédéral-provincial concernant le statut à accorder au français aurait affaibli l'attrait du français comme langue d'usage au foyer au Québec. Dans l'ensemble, la politique fédérale des langues officielles n'a pas ralenti l'anglicisation de la minorité francophone au Canada. D'autre part, la politique fédérale du multiculturalisme n'a pas modifié la tendance à l'anglicisation des autres minorités linguistiques canadiennes. Pour éviter l'anglicisation ultime du Canada, la politique linguistique canadienne devra évoluer vers une forme plus territoriale de bilinguisme, prenant appui sur un Québec français et culturellement plus autonome. Sans davantage de contenu biculturel, voire binational, l'actuelle politique fédérale ne fait pas le poids face au pouvoir d'assimilation de l'anglais dans le contexte nord-américain.
RESUMO
La anglalingvigo de Kanado, 1971-1981
Inter ciuj lingvaj malplimultoj de Kanado kaj precipe la eksterkebekiaj franclingvanoj, oni plieme uzis la anglan kiel lacefan hejman lingvon inter 1971 kaj 1981, laù popolnombradaj statistikoj. En Kebekio la supera anigemeco de la angla kompare al la franca almenau tiomis en 1981 kiomenl971. Sajne, la konflikto inter la fédéra kaj provincaj registaroj pri la rolo de la franca igas gin malpli valora kiel hejman lingvon en Kebekio. Générale, la kanada programo pri oficialaj lingvoj ne sukcesis malrapidigi la anglalingvigon de la franca malplimulto. Ankaù la federa programo de plurkultureco ne aliigis la anglalingvigon de la aliaj malplimultoj. Por eviti la plenan anglalingvigon de Kanado, oni devos reprincipigi la kanadan lingvan programon, celante pli laùlokan (anstataû ciupersonan) dulingvecon helpe de kulture pli memstara Kebekio. Sen plia dunacieco kaj dukultureco, la nuna federa programo ne efïke kontraùas la anigeman potencon de la angla en nordamerikaj kondicoj.