bluuebunny/crossref_metadata_2025 huggingface dataset:
Explaining and Measuring the Embrace of Local Agenda 21s by Local Governments
Authors: Barrutia Jose M , Echebarria Carmen
Published: March 2011

Previous research has identified factors affecting local government (LG) adoption of Local Agenda 21 (LA21). The objective of this research is to propose a measurement model and test it in the case of a specific region, the Basque Country. Research results show that the embrace of LA21 by LGs is explained by internal characteristics of LG and factors associated with LG environment, which is fostered, fundamentally, by higher levels of government that can create connected or networking processes. The most relevant external factors are associated with a concept under-emphasised in previous sustainable development literature: cocreation. We propose that, to achieve generalised diffusion of LA21-type tools, we should emphasise cocreation in networks instead of networks in general. The measurement model used in this research could be used in other contexts as a means of confirming or refuting our results and offer politicians a guide for achieving a more generalised and robust diffusion of LA21 processes. This research contributes to LA21 and innovation-adoption literatures.
Regional Imaginaries of Governance Agencies: Practising the Region of South West Britain
Authors: Harvey David C , Hawkins Harriet , Thomas Nicola J
Published: March 2011

Changes in government and governmentality in the UK have resulted in what has been termed a ‘regional renaissance’ over the last decade. This has led to an increase in the number of offices, institutions, and agencies operating with a regional remit that is based upon a notion of fixed territorial containers. One sector that has increasingly been brought into the orbit of the new regional policy framework is that of the creative industries, and research is required in order to understand how creative industry governance agencies imagine and interpret the regional spaces that they administer. Notwithstanding the supposedly agreed-upon and bounded nature of the territories over which they have competence, we find that personnel working within these regional bodies negotiate and imagine regional space in a number of ways. Drawing on empirical work with three creative-industry governance agencies in the South West of Britain, we consider a range of dynamic and sometimes contradictory understandings of regional space as practised through their policy development and implementation. The paper traces how the practice of creative-industry governance challenges the governmentally determined region and, by implication, any territorial unit as a naturally given container that is internally coherent and a discrete space available for governance. Hence, the paper has broader lessons for effective policy delivery more generally.
Assessing the toxicity of arsenic-bearing sulfide minerals with the bio-indicator Corophium volutator
Authors: Cui Longpeng , Newcombe Chris , Urgast Dagmar S. , Raab Andrea , Krupp Eva M. , Feldmann Jörg
Published: March 2011

Environmental context Risk identification and characterisation of As-bearing sulfide minerals, the most important natural source of arsenic pollution, is significant in pollution control and risk management at mine sites. Bioassays constitute a cost-efficient approach to toxicity testing because they give an integrated picture of the biologically available fraction thereby allowing predictions of the potential combined effects of contaminants in testing mixtures. Abstract A sediment-based toxicity test was designed to investigate the biological response of the amphipod Corophium volutator exposed to three common arsenic minerals, namely realgar (AsS), orpiment (As2S3) and arsenopyrite (Fe[AsS]). The LD50 for the loaded minerals and the added As in the sediment showed mineral-dependent toxicities increasing in the order of AsS�?�As2S3�<�Fe[AsS] (224?1329�mg�As�kg?1). The exposed animals accumulated arsenic in a mineral-dependent manner similar to the observed toxicity, with AsS�?�As2S3 and both higher than that for Fe[AsS]. The arsenic concentration in C. volutator at the LD50 exposure exhibits the same mineral independences, confirming that the response is arsenic specific. A significant increase in extractable inorganic arsenic in the tissue (over 100-fold) at higher arsenic exposures (up to 3% mineral-loading, w/w) was revealed hence no significant biotransformation of inorganic arsenic. C. volutator is sensitive to arsenic and has the potential to be used as a bio-indicator to assess the toxicity of arsenic-containing sediments or arsenic-containing mining wastes.
Arsenic distribution and species in two Zostera capricorni seagrass ecosystems, New South Wales, Australia
Authors: Maher William A. , Foster Simon D. , Taylor Anne M. , Krikowa Frank , Duncan Elliot G. , Chariton Anthony A.
Published: March 2011

Environmental context Arsenic concentrations and species were determined in seagrass ecosystems where the food web was established using carbon and nitrogen isotopes. There was a clear increase in the proportion of arsenobetaine in tissues of higher trophic level organisms, which is attributed to an increasing arsenobetaine content of the diet and the more efficient assimilation and retention of arsenobetaine over other arsenic species. The results provide an explanation for the prominence of arsenobetaine in higher marine animals. Abstract Arsenic concentrations and species were compared in biota from two Zostera capricorni ecosystems. Mean arsenic concentrations were not significantly different for non‐vegetative sediment, rhizosphere sediment, Z. capricorni blades, roots, rhizomes, epiphytes, amphipods, polychaetes, molluscs, crustaceans and fish, but were significantly different in detritus. Sediments and plant tissues contained mostly inorganic arsenic and PO4–arsenoriboside. Detritus contained mostly PO4–arsenoriboside. Fish tissues contained predominately arsenobetaine. Other animals had lower proportions of arsenobetaine and variable quantities of minor arsenic species. Bioconcentration but not biomagnification of arsenic is occurring with no evidence of arsenic hyper accumulation. The proportion of arsenobetaine increases through the food web and is attributed to a shift from a mixed diet at lower trophic levels to animals containing mostly arsenobetaine at higher trophic levels and the more efficient retention of arsenobetaine, compared to other arsenic species.
Intake and excretion of arsenicals in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata)
Authors: Agusa Tetsuro , Takagi Kozue , Miller Todd W. , Kubota Reiji , Anan Yasumi , Iwata Hisato , Tanabe Shinsuke
Published: March 2011

Environmental context Although among higher marine animals, relatively high concentration of arsenic and unique distribution of arsenic compounds are found in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata), the accumulation mechanism remains unknown. We examined the accumulation of arsenicals in two turtles from the standpoint of short- and long-term intake and excretion and found that prey items might be important for the arsenic accumulation. This study can provide useful information on the accumulation pattern of arsenic speciation in sea turtles. Abstract We analysed arsenic (As) compounds in the stomach and intestine contents, bile and urine of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) to understand As accumulation through intake and excretion. Stable isotopes of δ15N and δ13C were also measured for understanding the feeding behaviour dependent accumulation of As. Major As species in gastrointestinal contents were unknown water-soluble As, followed by unextracted As. Concentrations of AB and DMA in the tissues were higher than those in the stomach contents (prey items), indicating high bioaccumulation of these arsenicals. In green turtles, AB concentration was high in bile and increased throughout the gastrointestinal tract, suggesting significant biliary excretion of AB. δ15N was positively correlated with AB level in green turtles, whereas a negative relationship between residual As and δ15N was observed in hawksbill turtles. This study indicates feeding behaviour-dependent accumulation of As compounds in both turtle species for the first time.
Functional specialization for auditory–spatial processing in the occipital cortex of congenitally blind humans
Authors: Collignon Olivier , Vandewalle Gilles , Voss Patrice , Albouy Geneviève , Charbonneau Geneviève , Lassonde Maryse , Lepore Franco
Published: March 2011

The study of the congenitally blind (CB) represents a unique opportunity to explore experience-dependant plasticity in a sensory region deprived of its natural inputs since birth. Although several studies have shown occipital regions of CB to be involved in nonvisual processing, whether the functional organization of the visual cortex observed in sighted individuals (SI) is maintained in the rewired occipital regions of the blind has only been recently investigated. In the present functional MRI study, we compared the brain activity of CB and SI processing either the spatial or the pitch properties of sounds carrying information in both domains (i.e., the same sounds were used in both tasks), using an adaptive procedure specifically designed to adjust for performance level. In addition to showing a substantial recruitment of the occipital cortex for sound processing in CB, we also demonstrate that auditory–spatial processing mainly recruits the right cuneus and the right middle occipital gyrus, two regions of the dorsal occipital stream known to be involved in visuospatial/motion processing in SI. Moreover, functional connectivity analyses revealed that these reorganized occipital regions are part of an extensive brain network including regions known to underlie audiovisual spatial abilities (i.e., intraparietal sulcus, superior frontal gyrus). We conclude that some regions of the right dorsal occipital stream do not require visual experience to develop a specialization for the processing of spatial information and to be functionally integrated in a preexisting brain network dedicated to this ability.
Design and control of acetylcholine receptor conformational change
Authors: Jadey Snehal V. , Purohit Prasad , Bruhova Iva , Gregg Timothy M. , Auerbach Anthony
Published: March 2011

Allosteric proteins use energy derived from ligand binding to promote a global change in conformation. The “gating” equilibrium constant of acetylcholine receptor-channels (AChRs) is influenced by ligands, mutations, and membrane voltage. We engineered AChRs to have specific values of this constant by combining these perturbations, and then calculated the corresponding values for a reference condition. AChRs were designed to have specific rate and equilibrium constants simply by adding multiple, energetically independent mutations with known effects on gating. Mutations and depolarization (to remove channel block) changed the diliganded gating equilibrium constant only by changing the unliganded gating equilibrium constant (
E
0
) and did not alter the energy from ligand binding. All of the tested perturbations were approximately energetically independent. We conclude that naturally occurring mutations mainly adjust
E
0
and cause human disease because they generate AChRs that have physiologically inappropriate values of this constant. The results suggest that the energy associated with a structural change of a side chain in the gating isomerization is dissipated locally and is mainly independent of rigid body or normal mode motions of the protein. Gating rate and equilibrium constants are estimated for seven different AChR agonists using a stepwise engineering approach.
Neisseria meningitidis
is structured in clades associated with restriction modification systems that modulate homologous recombination
Authors: Budroni Sonia , Siena Emilio , Hotopp Julie C. Dunning , Seib Kate L. , Serruto Davide , Nofroni Chiara , Comanducci Maurizio , Riley David R. , Daugherty Sean C. , Angiuoli Samuel V. , Covacci Antonello , Pizza Mariagrazia , Rappuoli Rino , Moxon E. Richard , Tettelin Hervé , Medini Duccio
Published: March 2011

Molecular data on a limited number of chromosomal loci have shown that the population of
Neisseria meningitidis
(
Nm
), a deadly human pathogen, is structured in distinct lineages. Given that the
Nm
population undergoes substantial recombination, the mechanisms resulting in the evolution of these lineages, their persistence in time, and the implications for the pathogenicity of the bacterium are not yet completely understood. Based on whole-genome sequencing, we show that
Nm
is structured in phylogenetic clades. Through acquisition of specific genes and through insertions and rearrangements, each clade has acquired and remodeled specific genomic tracts, with the potential to impact on the commensal and virulence behavior of
Nm
. Despite this clear evidence of a structured population, we confirm high rates of detectable recombination throughout the whole
Nm
chromosome. However, gene conversion events were found to be longer within clades than between clades, suggesting a DNA cleavage mechanism associated with the phylogeny of the species. We identify 22 restriction modification systems, probably acquired by horizontal gene transfer from outside of the species/genus, whose distribution in the different strains coincides with the phylogenetic clade structure. We provide evidence that these clade-associated restriction modification systems generate a differential barrier to DNA exchange consistent with the observed population structure. These findings have general implications for the emergence of lineage structure and virulence in recombining bacterial populations, and they could provide an evolutionary framework for the population biology of a number of other bacterial species that show contradictory population structure and dynamics.
A neurodegenerative disease mutation that accelerates the clearance of apoptotic cells
Authors: Kao Aimee W. , Eisenhut Robin J. , Martens Lauren Herl , Nakamura Ayumi , Huang Anne , Bagley Josh A. , Zhou Ping , de Luis Alberto , Neukomm Lukas J. , Cabello Juan , Farese Robert V. , Kenyon Cynthia
Published: March 2011

Frontotemporal lobar degeneration is a progressive neurodegenerative syndrome that is the second most common cause of early-onset dementia. Mutations in the progranulin gene are a major cause of familial frontotemporal lobar degeneration [Baker M, et al. (2006)Nature442:916–919 and Cruts M, et al. (2006)Nature442:920–924]. Although progranulin is involved in wound healing, inflammation, and tumor growth, its role in the nervous system and the mechanism by which insufficient levels result in neurodegeneration are poorly understood [Eriksen and Mackenzie (2008)J Neurochem104:287–297]. We have characterized the normal function of progranulin in the nematodeCaenorhabditis elegans.We found that mutants lackingpgrn-1appear grossly normal, but exhibit fewer apoptotic cell corpses during development. This reduction in corpse number is not caused by reduced apoptosis, but instead by more rapid clearance of dying cells. Likewise, we found that macrophages cultured from progranulin KO mice displayed enhanced rates of apoptotic-cell phagocytosis. Although most neurodegenerative diseases are thought to be caused by the toxic effects of aggregated proteins, our findings suggest that susceptibility to neurodegeneration may be increased by a change in the kinetics of programmed cell death. We propose that cells that might otherwise recover from damage or injury are destroyed in progranulin mutants, which in turn facilitates disease progression.
Proteomics approach to study the functions of
Drosophila
myosin VI through identification of multiple cargo-binding proteins
Authors: Finan Dina , Hartman M. Amanda , Spudich James A.
Published: March 2011

Myosin VI is a molecular motor implicated in many processes, and it likely associates with a variety of cargoes that specify its functions. Although it is critical to
Drosophila
development, little is known about its cellular roles. To reveal its involvement in specific pathways, we sought to identify the binding partners of
Drosophila
myosin VI. We used affinity chromatography and mass spectrometry to discover interacting proteins, which we tested for direct binding. Using this approach, we found that the microtubule-associated protein Cornetto bound myosin VI, and we demonstrated a role for both in secretion of the lipidated morphogen Hedgehog. We also identified a number of other binding proteins, and further characterization of their interactions with myosin VI will advance our understanding of the roles of these complexes in cellular and developmental processes. Thus, our method has provided us the means to gain valuable insight into the multifaceted roles of a motor protein in vivo.
ATP-dependent and independent functions of Rad54 in genome maintenance
Authors: Agarwal Sheba , van Cappellen Wiggert A. , Guénolé Aude , Eppink Berina , Linsen Sam E.V. , Meijering Erik , Houtsmuller Adriaan , Kanaar Roland , Essers Jeroen
Published: March 2011

Rad54, a member of the SWI/SNF protein family of DNA-dependent ATPases, repairs DNA double-strand breaks (DSBs) through homologous recombination. Here we demonstrate that Rad54 is required for the timely accumulation of the homologous recombination proteins Rad51 and Brca2 at DSBs. Because replication protein A and Nbs1 accumulation is not affected by Rad54 depletion, Rad54 is downstream of DSB resection. Rad54-mediated Rad51 accumulation does not require Rad54’s ATPase activity. Thus, our experiments demonstrate that SWI/SNF proteins may have functions independent of their ATPase activity. However, quantitative real-time analysis of Rad54 focus formation indicates that Rad54’s ATPase activity is required for the disassociation of Rad54 from DNA and Rad54 turnover at DSBs. Although the non–DNA-bound fraction of Rad54 reversibly interacts with a focus, independent of its ATPase status, the DNA-bound fraction is immobilized in the absence of ATP hydrolysis by Rad54. Finally, we show that ATP hydrolysis by Rad54 is required for the redistribution of DSB repair sites within the nucleus.
Dectin-2 mediates Th2 immunity through the generation of cysteinyl leukotrienes
Authors: Barrett Nora A. , Rahman Opu M. , Fernandez James M. , Parsons Matthew W. , Xing Wei , Austen K. Frank , Kanaoka Yoshihide
Published: March 2011

The innate signaling pathways for Th2 immunity activated by inhaled antigens are not well defined. We previously identified Dectin-2 as a receptor for glycans in allergen extracts from the house dust mite Dermatophagoides farinae (Df) that mediates cysteinyl leukotriene (cys-LT) generation from pulmonary CD11c+ cells and from GM-CSF–cultured bone marrow cells (BMCsGM-CSF). Using lentiviral knockdown of Dectin-2 in BMCsGM-CSF and adoptive transfer of Df-pulsed BMCsGM-CSF to sensitize naive mice, we now report that Dectin-2 is critical for the development of Df-elicited eosinophilic and neutrophilic pulmonary inflammation and Th2 cytokine generation in the lungs and restimulated lymph nodes. Sensitization with Df-pulsed BMCsGM-CSF from LTC4 synthase (LTC4S)–deficient mice or type 1 cys-LT receptor (CysLT1R)–deficient mice demonstrated that both proteins were required for Df-elicited eosinophilic pulmonary inflammation and Th2 cytokine generation in the lungs and restimulated lymph nodes. Direct sensitization and challenge of Ltc4s−/− and Cysltr1−/− mice confirmed that cys-LTs mediate these parameters of Df-elicited Th2 pulmonary inflammation. Thus, the Dectin-2–cys-LT pathway is critical for the induction of Th2 immunity to a major allergen, in part through CysLT1R. These findings identify a previously unrecognized link between a myeloid C-type lectin receptor and Th2 immunity.
MPER-specific antibodies induce gp120 shedding and irreversibly neutralize HIV-1
Authors: Ruprecht Claudia R. , Krarup Anders , Reynell Lucy , Mann Axel M. , Brandenberg Oliver F. , Berlinger Livia , Abela Irene A. , Regoes Roland R. , Günthard Huldrych F. , Rusert Peter , Trkola Alexandra
Published: March 2011

Interference with virus entry is known to be the principle mechanism of HIV neutralization by antibodies, including 2F5 and 4E10, which bind to the membrane-proximal external region (MPER) of the gp41 envelope protein. However, to date, the precise molecular events underlying neutralization by MPER-specific antibodies remain incompletely understood. In this study, we investigated the capacity of these antibodies to irrevocably sterilize HIV virions. Long-term effects of antibodies on virions can differ, rendering neutralization either reversible or irreversible. MPER-specific antibodies irreversibly neutralize virions, and this capacity is associated with induction of gp120 shedding. Both processes have similar thermodynamic properties and slow kinetics requiring several hours. Antibodies directed to the CD4 binding site, V3 loop, and the MPER can induce gp120 shedding, and shedding activity is detected with high frequency in plasma from patients infected with divergent genetic HIV-1 subtypes. Importantly, as we show in this study, induction of gp120 shedding is closely associated with MPER antibody inhibition, constituting either a primary event leading to virion neutralization or representing an immediate consequence thereof, and thus needs to be factored into the mechanistic processes underlying their activity.
Production of iodine atoms by RF discharge decomposition of CF3I
Authors: Jirásek Vít , Schmiedberger Josef , Čenský Miroslav , Kodymová Jarmila
Published: March 2011

Generation of atomic iodine by dissociation of CF3I in a RF discharge was studied experimentally in a configuration ready for direct use of the method in an oxygen–iodine laser. The discharge was ignited between coaxial electrodes with a radial distance of 3.5 mm in a flowing mixture of 0.1–0.9 mmol s−1 of CF3I and 0.5–6 mmol s−1 of buffer gas (Ar, He) at a pressure of 2–3 kPa. The discharge stability was improved by different approaches so that the discharge could be operated up to a RF source limit of 500 W without sparking. The gas leaving the discharge was injected into the subsonic or supersonic flow of N2 and the concentration of generated atomic iodine and gas temperature were measured downstream of the injection. An inhomogeneous distribution of the produced iodine atoms among the injector exit holes was observed, which was attributed to a different gas residence time corresponding to each hole. The dissociation fraction was better with pure argon as a diluting gas than in the mixture of Ar–He, although the variation in the Ar flow rate had no significant effect on CF3I dissociation. The dissociation fraction calculated from the atomic iodine concentration measured several centimetres downstream of the injection was in the range 7–30% when the absorbed electric energy ranged from 200 to 4000 J per 1 mmol of CF3I. The corresponding values of the fraction of power spent on the dissociation decreased from 8% to 2% and the energy cost for one iodine atom increased from 30 to 130 eV. Due to a possible high rate of the atomic iodine loss by recombination after leaving the discharge, these values were considered as lower limits of those achieved in the discharge.
Stem Rust Resistance in A-Genome Diploid Relatives of Wheat
Authors: Rouse M. N. , Jin Y.
Published: March 2011

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, has been effectively controlled through the use of genetic resistance. P. graminis f. sp. tritici race TTKSK (Ug99) possesses virulence to many resistance genes that have been used in wheat breeding worldwide. One strategy to aid breeders in developing resistant cultivars is to utilize resistance genes transferred from wild relatives to wheat. Stem rust resistance genes have previously been introgressed from Triticum monococcum to wheat. In order to identify additional resistance genes, we screened 1,061 accessions of T. monococcum and 205 accessions of T. urartu against race TTKSK and four additional P. graminis f. sp. tritici races: TTTTF, TRTTF, QFCSC, and MCCFC. A high frequency of the accessions (78.7% of T. monococcum and 93.0% of T. urartu) were resistant to P. graminis f. sp. tritici race TTKSK, with infection types ranging from 0 to 2+. Among these resistant accessions, 55 T. monococcum accessions (6.4% of the total) were also resistant to the other four races. Associations of resistance in T. monococcum germplasm to different races indicated the presence of genes conferring resistance to multiple races. Comparing the observed infection type patterns to the expected patterns of known genes indicated that previously uncharacterized genes for resistance to race TTKSK exist in both T. monococcum and T. urartu.
Potato virus M in Bittersweet Nightshade (Solanum dulcamara) in New York State
Authors: Perry K. L. , McLane H.
Published: March 2011

Potato virus M (PVM) was detected in upstate New York in two plants of the widely naturalized, weedy perennial Solanum dulcamara. The virus was detected with a macroarray assay for potato viruses (1). Amplified, complimentary DNAs from the two isolates hybridized to 5 and 7 of the 15 oligonucleotide probes for PVM. Testing of the samples by double-antibody sandwich-ELISA using PVM-specific antibodies (Agdia, Elkhart, IN) showed a clear positive result. Sequence information for a 118-bp genomic region was obtained by amplification using carlavirus-specific primers (2) (GenBank Accession No. HQ446853). Comparison with a reference PVM genome (GenBank Accession No. NC_001361) showed that the sequence corresponded to nucleotide positions 8418 to 8533 with 86% identity. The infected plants were symptomless and collected from two sites, 50 miles apart. One site was a weedy roadside location in Tompkins County in 2009, while the second was from a hedgerow in a (non-potato) vegetable production area of Ontario County in 2010. The virus could be detected throughout the growing season in this perennial host. PVM was reported from S. dulcamara L. in Hungary and described as being found frequently from a diversity of habitats (3). Importantly, the virus was transmitted via tubers and by Myzus persicae with low efficiency (3). These results suggest that the virus may be endemic in S. dulcamara in the northeastern United States and this host may serve as a reservoir for the virus from which it could move into potato. To our knowledge, PVM has not been reported in this host in North America.

References: (1) B. Agindotan and K. L. Perry. Plant Dis. 92:730, 2008. (2) J. Badge et al. Eur. J. Plant Pathol. 102:305, 1996. (3) P. Salamon. Eur. Assoc. Pot. Res. Virol. Sect. Meet. 42:121, 2006.
How do we use language? Shared patterns in the frequency of word use across 17 world languages
Authors: Calude Andreea S. , Pagel Mark
Published: March 2011

We present data from 17 languages on the frequency with which a common set of words is used in everyday language. The languages are drawn from six language families representing 65 per cent of the world's 7000 languages. Our data were collected from linguistic corpora that record frequencies of use for the 200 meanings in the widely used Swadesh fundamental vocabulary. Our interest is to assess evidence for shared patterns of language use around the world, and for the relationship of language use to rates of lexical replacement, defined as the replacement of a word by a new unrelated or non-cognate word. Frequencies of use for words in the Swadesh list range from just a few per million words of speech to 191 000 or more. The average inter-correlation among languages in the frequency of use across the 200 words is 0.73 (
p
< 0.0001). The first principal component of these data accounts for 70 per cent of the variance in frequency of use. Elsewhere, we have shown that frequently used words in the Indo-European languages tend to be more conserved, and that this relationship holds separately for different parts of speech. A regression model combining the principal factor loadings derived from the worldwide sample along with their part of speech predicts 46 per cent of the variance in the rates of lexical replacement in the Indo-European languages. This suggests that Indo-European lexical replacement rates might be broadly representative of worldwide rates of change. Evidence for this speculation comes from using the same factor loadings and part-of-speech categories to predict a word's position in a list of 110 words ranked from slowest to most rapidly evolving among 14 of the world's language families. This regression model accounts for 30 per cent of the variance. Our results point to a remarkable regularity in the way that human speakers use language, and hint that the words for a shared set of meanings have been slowly evolving and others more rapidly evolving throughout human history.
Social traditions and social learning in capuchin monkeys (Cebus)
Authors: Perry Susan
Published: March 2011

Capuchin monkeys (genusCebus) have evolutionarily converged with humans and chimpanzees in a number of ways, including large brain size, omnivory and extractive foraging, extensive cooperation and coalitionary behaviour and a reliance on social learning. Recent research has documented a richer repertoire of group-specific social conventions in the coalition-proneCebus capucinusthan in any other non-human primate species; these social rituals appear designed to test the strength of social bonds. Such diverse social conventions have not yet been noted inCebus apella, despite extensive observation at multiple sites. The more robust and widely distributedC. apellais notable for the diversity of its tool-use repertoire, particularly in marginal habitats. AlthoughC. capucinusdoes not often use tools, white-faced capuchins do specialize in foods requiring multi-step processing, and there are often multiple techniques used by different individuals within the same social group. Immatures preferentially observe foragers who are eating rare foods and hard-to-process foods. Young foragers, especially females, tend to adopt the same foraging techniques as their close associates.
On the nature of cultural transmission networks: evidence from Fijian villages for adaptive learning biases
Authors: Henrich Joseph , Broesch James
Published: March 2011

Unlike other animals, humans are heavily dependent on cumulative bodies of culturally learned information. Selective processes operating on this socially learned information can produce complex, functionally integrated, behavioural repertoires—cultural adaptations. To understand such non-genetic adaptations, evolutionary theorists propose that (i) natural selection has favoured the emergence of psychological biases for learning from those individuals most likely to possess adaptive information, and (ii) when these psychological learning biases operate in populations, over generations, they can generate cultural adaptations. Many laboratory experiments now provide evidence for these psychological biases. Here, we bridge from the laboratory to the field by examining if and how these biases emerge in a small-scale society. Data from three cultural domains—fishing, growing yams and using medicinal plants—show that Fijian villagers (ages 10 and up) are biased to learn from others perceived as more successful/knowledgeable, both within and across domains (prestige effects). We also find biases for sex and age, as well as proximity effects. These selective and centralized oblique transmission networks set up the conditions for adaptive cultural evolution.
From fish to fashion: experimental and theoretical insights into the evolution of culture
Authors: Laland K. N. , Atton N. , Webster M. M.
Published: March 2011

Recent years have witnessed a re-evaluation of the cognitive capabilities of fishes, including with respect to social learning. Indeed, some of the best experimental evidence for animal traditions can be found in fishes. Laboratory experimental studies reveal that many fishes acquire dietary, food site and mating preferences, predator recognition and avoidance behaviour, and learn pathways, through copying1other fishes. Concentrating on foraging behaviour, we will present the findings of laboratory experiments that reveal social learning, behavioural innovation, the diffusion of novel behaviour through populations and traditional use of food sites. Further studies reveal surprisingly complex social learning strategies deployed by sticklebacks. We will go on to place these observations of fish in a phylogenetic context, describing in which respects the learning and traditionality of fish are similar to, and differ from, that observed in other animals. We end by drawing on theoretical insights to suggest processes that may have played important roles in the evolution of the human cultural capability.
The scope and limits of overimitation in the transmission of artefact culture
Authors: Lyons Derek E. , Damrosch Diana H. , Lin Jennifer K. , Macris Deanna M. , Keil Frank C.
Published: March 2011

Children are generally masterful imitators, both rational and flexible in their reproduction of others' actions. After observing an adult operating an unfamiliar object, however, young children will frequentlyoverimitate, reproducing not only the actions that were causally necessary but also those that were clearly superfluous. Why does overimitation occur? We argue that when children observe an adult intentionally acting on a novel object, they may automatically encode all of the adult's actions as causally meaningful. This process ofautomatic causal encoding(ACE) would generally guide children to accurate beliefs about even highly opaque objects. In situations where some of an adult's intentional actions were unnecessary, however, it would also lead to persistent overimitation. Here, we undertake a thorough examination of the ACE hypothesis, reviewing prior evidence and offering three new experiments to further test the theory. We show that children will persist in overimitating even when doing so is costly (underscoring the involuntary nature of the effect), but also that the effect is constrained by intentionality in a manner consistent with its posited learning function. Overimitation may illuminate not only the structure of children's causal understanding, but also the social learning processes that support our species' artefact-centric culture.
The evolution of primate general and cultural intelligence
Authors: Reader Simon M. , Hager Yfke , Laland Kevin N.
Published: March 2011

There are consistent individual differences in human intelligence, attributable to a single ‘general intelligence’ factor,g. The evolutionary basis ofgand its links to social learning and culture remain controversial. Conflicting hypotheses regard primate cognition as divided into specialized, independently evolving modules versus a single general process. To assess how processes underlying culture relate to one another and other cognitive capacities, we compiled ecologically relevant cognitive measures from multiple domains, namely reported incidences of behavioural innovation, social learning, tool use, extractive foraging and tactical deception, in 62 primate species. All exhibited strong positive associations in principal component and factor analyses, after statistically controlling for multiple potential confounds. This highly correlated composite of cognitive traits suggests social, technical and ecological abilities have coevolved in primates, indicative of an across-species general intelligence that includes elements of cultural intelligence. Our composite species-level measure of general intelligence, ‘primategS’, covaried with both brain volume and captive learning performance measures. Our findings question the independence of cognitive traits and do not support ‘massive modularity’ in primate cognition, nor an exclusively social model of primate intelligence. High general intelligence has independently evolved at least four times, with convergent evolution in capuchins, baboons, macaques and great apes.
Social learning in birds and its role in shaping a foraging niche
Authors: Slagsvold Tore , Wiebe Karen L.
Published: March 2011

We briefly review the literature on social learning in birds, concluding that strong evidence exists mainly for predator recognition, song, mate choice and foraging. The mechanism of local enhancement may be more important than imitation for birds learning to forage, but the former mechanism may be sufficient for faithful transmission depending on the ecological circumstances. To date, most insights have been gained from birds in captivity. We present a study of social learning of foraging in two passerine birds in the wild, where we cross-fostered eggs between nests of blue tits,
Cyanistes caeruleus
and great tits,
Parus major
. Early learning causes a shift in the foraging sites used by the tits in the direction of the foster species. The shift in foraging niches was consistent across seasons, as showed by an analysis of prey items, and the effect lasted for life. The fact that young birds learn from their foster parents, and use this experience later when subsequently feeding their own offspring, suggests that foraging behaviour can be culturally transmitted over generations in the wild. It may therefore have both ecological and evolutionary consequences, some of which are discussed.
Stone toolmaking and the evolution of human culture and cognition
Authors: Stout Dietrich
Published: March 2011

Although many species display behavioural traditions, human culture is unique in the complexity of its technological, symbolic and social contents. Is this extraordinary complexity a product of cognitive evolution, cultural evolution or some interaction of the two? Answering this question will require a much better understanding of patterns of increasing cultural diversity, complexity and rates of change in human evolution. Palaeolithic stone tools provide a relatively abundant and continuous record of such change, but a systematic method for describing the complexity and diversity of these early technologies has yet to be developed. Here, an initial attempt at such a system is presented. Results suggest that rates of Palaeolithic culture change may have been underestimated and that there is a direct relationship between increasing technological complexity and diversity. Cognitive evolution and the greater latitude for cultural variation afforded by increasingly complex technologies may play complementary roles in explaining this pattern.
Social learning among Congo Basin hunter–gatherers
Authors: Hewlett Barry S. , Fouts Hillary N. , Boyette Adam H. , Hewlett Bonnie L.
Published: March 2011

This paper explores childhood social learning among Aka and Bofi hunter–gatherers in Central Africa. Existing literature suggests that hunter–gatherer social learning is primarily vertical (parent-to-child) and that teaching is rare. We use behavioural observations, open-ended and semi-structured interviews, and informal and anecdotal observations to examine the modes (e.g. vertical versus horizontal/oblique) and processes (e.g. teaching versus observation and imitation) of cultural transmission. Cultural and demographic contexts of social learning associated with the modes and processes of cultural transmission are described. Hunter–gatherer social learning occurred early, was relatively rapid, primarily vertical under age 5 and oblique and horizontal between the ages of 6 and 12. Pedagogy and other forms of teaching existed as early as 12 months of age, but were relatively infrequent by comparison to other processes of social learning such as observation and imitation.
How copying affects the amount, evenness and persistence of cultural knowledge: insights from the social learning strategies tournament
Authors: Rendell L. , Boyd R. , Enquist M. , Feldman M. W. , Fogarty L. , Laland K. N.
Published: March 2011

Darwinian processes should favour those individuals that deploy the most effective strategies for acquiring information about their environment. We organized a computer-based tournament to investigate which learning strategies would perform well in a changing environment. The most successful strategies relied almost exclusively on social learning (here, learning a behaviour performed by another individual) rather than asocial learning, even when environments were changing rapidly; moreover, successful strategies focused learning effort on periods of environmental change. Here, we use data from tournament simulations to examine how these strategies might affect cultural evolution, as reflected in the amount of culture (i.e. number of cultural traits) in the population, the distribution of cultural traits across individuals, and their persistence through time. We found that high levels of social learning are associated with a larger amount of more persistent knowledge, but a smaller amount of less persistent expressed behaviour, as well as more uneven distributions of behaviour, as individuals concentrated on exploiting a smaller subset of behaviour patterns. Increased rates of environmental change generated increases in the amount and evenness of behaviour. These observations suggest that copying confers on cultural populations an adaptive plasticity, allowing them to respond to changing environments rapidly by drawing on a wider knowledge base.
Language evolution and human history: what a difference a date makes
Authors: Gray Russell D. , Atkinson Quentin D. , Greenhill Simon J.
Published: March 2011

Historical inference is at its most powerful when independent lines of evidence can be integrated into a coherent account. Dating linguistic and cultural lineages can potentially play a vital role in the integration of evidence from linguistics, anthropology, archaeology and genetics. Unfortunately, although the comparative method in historical linguistics can provide a relative chronology, it cannot provide absolute date estimates and an alternative approach, called glottochronology, is fundamentally flawed. In this paper we outline how computational phylogenetic methods can reliably estimate language divergence dates and thus help resolve long-standing debates about human prehistory ranging from the origin of the Indo-European language family to the peopling of the Pacific.
The anti-tumor drug E7107 reveals an essential role for SF3b in remodeling U2 snRNP to expose the branch point-binding region
Authors: Folco Eric G. , Coil Kaitlyn E. , Reed Robin
Published: March 2011

Duplex formation between the branch point-binding region (BBR) of U2 snRNA and the branch point sequence (BPS) in the intron is essential for splicing. Both the BBR and BPS interact with the U2 small nuclear ribonucleoprotein (snRNP)-associated SF3b complex, which is the target of the anti-tumor drug E7107. We show that E7107 blocks spliceosome assembly by preventing tight binding of U2 snRNP to pre-mRNA. E7107 has no apparent effect on U2 snRNP integrity. Instead, E7107 abolishes an ATP-dependent conformational change in U2 snRNP that exposes the BBR. We conclude that SF3b is required for this remodeling, which exposes the BBR for tight U2 snRNP binding to pre-mRNA.
Subnuclear segregation of genes and core promoter factors in myogenesis
Authors: Yao Jie , Fetter Richard D. , Hu Ping , Betzig Eric , Tjian Robert
Published: March 2011

Recent findings implicate alternate core promoter recognition complexes in regulating cellular differentiation. Here we report a spatial segregation of the alternative core factor TAF3, but not canonical TFIID subunits, away from the nuclear periphery, where the key myogenic gene MyoD is preferentially localized in myoblasts. This segregation is correlated with the differential occupancy of TAF3 versus TFIID at the MyoD promoter. Loss of this segregation by modulating either the intranuclear location of the MyoD gene or TAF3 protein leads to altered TAF3 occupancy at the MyoD promoter. Intriguingly, in differentiated myotubes, the MyoD gene is repositioned to the nuclear interior, where TAF3 resides. The specific high-affinity recognition of H3K4Me3 by the TAF3 PHD (plant homeodomain) finger appears to be required for the sequestration of TAF3 to the nuclear interior. We suggest that intranuclear sequestration of core transcription components and their target genes provides an additional mechanism for promoter selectivity during differentiation.
Autoregulation of convergent RNAi genes in fission yeast
Authors: Gullerova Monika , Moazed Danesh , Proudfoot Nick J.
Published: March 2011

RNAi plays a central role in the regulation of eukaryotic genes. In Schizosaccharomyces pombe fission yeast, RNAi involves the formation of siRNA from dsRNA that acts to establish and maintain heterochromatin over centromeres, telomeres, and mating loci. We showed previously that transient heterochromatin also forms over S. pombe convergent genes (CGs). Remarkably, most RNAi genes are themselves convergent. We demonstrate here that transient heterochromatin formed by the RNAi pathway over RNAi CGs leads to their autoregulation in G1–S. Furthermore, the switching of RNAi gene orientation from convergent to tandem causes loss of their G1–S down-regulation. Surprisingly, yeast mutants with tandemized dcr1, ago1, or clr4 genes display aberrant centromeric heterochromatin, which results in abnormal cell morphology. Our results emphasize the significance of gene orientation for correct RNAi gene expression, and suggest a role for cell cycle-dependent formation of RNAi CG heterochromatin in cellular integrity.
The Physiological Role of Ascorbate as Photosystem II Electron Donor: Protection against Photoinactivation in Heat-Stressed Leaves
Authors: Tóth Szilvia Z. , Nagy Valéria , Puthur Jos T. , Kovács László , Garab Győző
Published: March 2011

Previously, we showed that ascorbate (Asc), by donating electrons to photosystem II (PSII), supports a sustained electron transport activity in leaves in which the oxygen-evolving complexes were inactivated with a heat pulse (49°C, 40 s). Here, by using wild-type, Asc-overproducing, and -deficient Arabidopsis (Arabidopsis thaliana) mutants (miox4 and vtc2-3, respectively), we investigated the physiological role of Asc as PSII electron donor in heat-stressed leaves (40°C, 15 min), lacking active oxygen-evolving complexes. Chlorophyll-a fluorescence transients show that in leaves excited with trains of saturating single-turnover flashes spaced 200 ms apart, allowing continual electron donation from Asc to PSII, the reaction centers remained functional even after thousands of turnovers. Higher flash frequencies or continuous illumination (300 μmol photons m−2 s−1) gradually inactivated them, a process that appeared to be initiated by a dramatic deceleration of the electron transfer from TyrZ to P680+, followed by the complete loss of charge separation activity. These processes occurred with half-times of 1.2 and 10 min, 2.8 and 23 min, and 4.1 and 51 min in vtc2-3, the wild type, and miox4, respectively, indicating that the rate of inactivation strongly depended on the Asc content of the leaves. The recovery of PSII activity, following the degradation of PSII proteins (D1, CP43, and PsbO), in moderate light (100 μmol photons m−2 s−1, comparable to growth light), was also retarded in the Asc-deficient mutant. These data show that high Asc content of leaves contributes significantly to the ability of plants to withstand heat-stress conditions.