bluuebunny/crossref_metadata_2025 huggingface dataset:
Addiction Medicine in Canada: Challenges and Prospects
Authors: el-Guebaly Nady , Crockford David , Cirone Sharon , Kahan Meldon
Published: January 2011

In Canada, the qualification of physicians is the jurisdiction of the College of Family Physicians and the Royal College of Physicians and Surgeons. The Colleges have promoted the training of “generalists” in family medicine and “sophisticated generalists” among the traditional specialties, and the development of subspecialties has not been encouraged. Nevertheless, due to the increasing number of family physicians and specialists practicing a range of new subspecialties, including addiction medicine, the College of Family Physicians has recognized special interest or focused practices, whereas the Royal College has recognized, in psychiatry, 3 subspecialties (child, geriatric, forensic) requiring an extra year of training and may offer others a diploma recognition. These new opportunities will shape the training requirements of addiction medicine leading to available certification through the International and American Medical Societies of Addiction Medicine.
Italian coalitions and electoral promises: assessing the democratic performance of the Prodi I and Berlusconi II governments
Authors: Moury Catherine
Published: January 2011

Italian party coalitions (from both the centre-left and the centre-right) have enacted an average of 57% of the pledges included in their common manifestos. In relative terms, Italian political parties keep their electoral promises much less than parties governing in single-party government, but slightly outperform those that form post-electoral coalitions. Although this finding contradicts the widespread pessimism about Italy's performance, it also illustrates that there is no significant advantage to bipolarism and the existence of a common programme as opposed to situations where coalitions are formed after the elections. This might explain Italians’ dissatisfaction with the way democracy works in their country.
Good workers: television documentary, migration and the Italian nation, 1956–1964
Authors: Hayward Mark
Published: January 2011

This paper examines a series of documentaries produced in the period between 1956 and 1964 that document the activities of Italian migrants around the world (a corpus of more than 100 films and programmes altogether). These films, which record the dedicated and laborious nature of Italians around the globe, play a double role. On the one hand, they serve as a necessary adjunct to the establishment of a ‘labour culture’ in Italy, a central aspect of the compromise between labour unrest and the demands of capital in which the figure of the worker is continually praised. At the same time, they serve to obscure and rewrite the Italian collective memory concerning the legacy of Fascist imperialism and Italian involvement in colonial expansion, in the process recasting the Italian coloniser as the ‘good worker’.
‘For a healthy, peace-loving and hardworking race’: anthropology and eugenics in the writings of Giuseppe Sergi
Authors: Tedesco Luca
Published: January 2011

The purpose of this essay is to analyse the eugenic pacifism of Giuseppe Sergi, one of Italy's most important anthropologists working at the turn of the nineteenth and twentieth centuries. Sergi's eugenic proposal, while accepting the long-contested idea of Weismann's germ plasm theory, preserves Lamarck's theory of the conditioning effect of the environment through the cautious use of Gregor Mendel's theory of recessiveness. Sergi, co-founder of the eugenic movement in Italy, thus affirmed the ‘salvific’ power of an upbringing that would assume the task of carrying forward to future generations the recessiveness of traits of violence, which would thereby assure humankind a prosperous future guaranteed by ‘competition between the races’, a competition that would no longer be on the battlefield but in the fields of industry, art and science.
Images of Lombardy in historiography
Authors: Soresina Marco
Published: January 2011

The historiography of contemporary Lombardy has been dominated by in-depth studies of local contexts but has rarely addressed the regional dimension. Those studies that have had a regional outlook have drawn divergent and fluid regional boundaries, rarely connected to the administrative and by now political reality of the region of Lombardy. This article aims to reconstruct some of the most salient moments of this ‘identification’ of Lombardy in the economic, social and administrative history of the region. It tries to trace the cultural roots and persistence of this identification, which has sometimes been embroiled in political controversy. Focusing mainly on more recent studies, this article will also address the aporias and unsolved issues surrounding the study of Lombardy.
Supervised versus Unsupervised Categorization: Two Sides of the Same Coin?
Authors: Pothos Emmanuel M. , Edwards Darren J. , Perlman Amotz
Published: January 2011

Supervised and unsupervised categorization have been studied in separate research traditions. A handful of studies have attempted to explore a possible convergence between the two. The present research builds on these studies, by comparing the unsupervised categorization results of Pothos et al. (2011; Pothos et al., 2008) with the results from two procedures of supervised categorization. In two experiments, we tested 375 participants with nine different stimulus sets and examined the relation between ease of learning of a classification, memory for a classification, and spontaneous preference for a classification. After taking into account the role of the number of category labels (clusters) in supervised learning, we found the three variables to be closely associated with each other. Our results provide encouragement for researchers seeking unified theoretical explanations for supervised and unsupervised categorization, but raise a range of challenging theoretical questions.
Do Complex Models Increase Prediction of Complex Behaviours? Predicting Driving Ability in People with Brain Disorders
Authors: Innes Carrie R. H. , Lee Dominic , Chen Chen , Ponder-Sutton Agate M. , Melzer Tracy R. , Jones Richard D.
Published: January 2011

Prediction of complex behavioural tasks via relatively simple modelling techniques, such as logistic regression and discriminant analysis, often has limited success. We hypothesized that to more accurately model complex behaviour, more complex models, such as kernel-based methods, would be needed. To test this hypothesis, we assessed the value of six modelling approaches for predicting driving ability based on performance on computerized sensory–motor and cognitive tests ( SMCTests™) in 501 people with brain disorders. The models included three models previously used to predict driving ability (discriminant analysis, DA; binary logistic regression, BLR; and nonlinear causal resource analysis, NCRA) and three kernel methods (support vector machine, SVM; product kernel density, PK; and kernel product density, KP). At the classification level, two kernel methods were substantially more accurate at classifying on-road pass or fail (SVM 99.6%, PK 99.8%) than the other models (DA 76%, BLR 78%, NCRA 74%, KP 81%). However, accuracy decreased substantially for all of the kernel models when cross-validation techniques were used to estimate prediction of on-road pass or fail in an independent referral group (SVM 73–76%, PK 72–73%, KP 71–72%) but decreased only slightly for DA (74–75%) and BLR (75–76%). Cross-validation of NCRA was not possible. In conclusion, while kernel-based models are successful at modelling complex data at a classification level, this is likely to be due to overfitting of the data, which does not lead to an improvement in accuracy in independent data over and above the accuracy of other less complex modelling techniques.
Biomedical and environmental applications of magnetic nanoparticles
Authors: Tran Dai Lam , Le Van Hong , Pham Hoai Linh , Hoang Thi My Nhung , Nguyen Thi Quy , Luong Thien Tai , Ha Phuong Thu , Nguyen Xuan Phuc
Published: January 2011

This paper presents an overview of syntheses and applications of magnetic nanoparticles (MNPs) at the Institute of Materials Science, Vietnam Academy of Science and Technology. Three families of oxide MNPs, magnetite, manganite and spinel ferrite materials, were prepared in various ways: coprecipitation, sol–gel and high energy mechanical milling. Basic properties of MNPs were characterized by Vibrating Sample Magnetometer (VSM) and Physical Properties Measurement Systems (PPMS). As for biomedical application, the aim was to design a novel multifunctional, nanosized magnetofluorescent water-dispersible Fe
3
O
4-curcumin conjugate, and its ability to label, target and treat tumor cells was described. The conjugate possesses a magnetic nano Fe
3
O
4 core, chitosan (CS) or Oleic acid (OL) as an outer shell and entrapped curcumin (Cur), serving the dual function of naturally autofluorescent dye as well as antitumor model drug. Fe
3
O
4-Cur conjugate exhibited a high loading cellular uptake with the help of a macrophage, which was clearly visualized dually by Fluorescence Microscope and Laser Scanning Confocal Microscope (LSCM), as well as by magnetization measurement (PPMS). A preliminary magnetic resonance imaging (MRI) study also showed a clear contrast enhancement by using the conjugate. As for the environmental aspect, the use of magnetite MNPs for the removal of heavy toxic metals, such as Arsenic (As) and Lead (Pb), from contaminated water was studied.
New proofs for the Abhyankar-Gurjar inversion formula and the equivalence of the Jacobian conjecture and the vanishing conjecture
Authors: Zhao Wenhua
Published: January 2011

We first give a new proof and also a new formulation for the Abhyankar-Gurjar inversion formula for formal maps of affine spaces. We then use the reformulated Abhyankar-Gurjar formula to give a more straightforward proof for the equivalence of the Jacobian conjecture with a special case of the vanishing conjecture of (homogeneous) quadratic differential operators with constant coefficients.
Infinitesimal Einstein deformations of nearly Kähler metrics
Authors: Moroianu Andrei , Semmelmann Uwe
Published: January 2011

It is well known that every 6-dimensional strictly nearly Kähler manifold

(
M
,
g
,
J
)

(M,g,J)

is Einstein with positive scalar curvature

scal
>
0

\operatorname {scal}>0

. Moreover, one can show that the space

E
E

of co-closed primitive

(
1
,
1
)

(1,1)

-forms on

M
M

is stable under the Laplace operator

Δ
\Delta

. Let

E
(
λ
)

E(\lambda )

denote the

λ
\lambda

-eigenspace of the restriction of

Δ
\Delta

to

E
E

. If

M
M

is compact, and has normalized scalar curvature

scal
=
30

\operatorname {scal}=30

, we prove that the moduli space of infinitesimal Einstein deformations of the nearly Kähler metric

g
g

is naturally isomorphic to the direct sum

E
(
2
)
⊕
E
(
6
)
⊕
E
(
12
)

E(2)\oplus E(6)\oplus E(12)

. From Moroianu, Nagy, and Semmelmann (2008), the last summand is itself isomorphic with the moduli space of infinitesimal nearly Kähler deformations.
An efficient hierarchical generalized linear mixed model for pathway analysis of genome-wide association studies
Authors: Wang Lily , Jia Peilin , Wolfinger Russell D. , Chen Xi , Grayson Britney L. , Aune Thomas M. , Zhao Zhongming
Published: January 2011

Motivation: In genome-wide association studies (GWAS) of complex diseases, genetic variants having real but weak associations often fail to be detected at the stringent genome-wide significance level. Pathway analysis, which tests disease association with combined association signals from a group of variants in the same pathway, has become increasingly popular. However, because of the complexities in genetic data and the large sample sizes in typical GWAS, pathway analysis remains to be challenging. We propose a new statistical model for pathway analysis of GWAS. This model includes a fixed effects component that models mean disease association for a group of genes, and a random effects component that models how each gene's association with disease varies about the gene group mean, thus belongs to the class of mixed effects models.

Results: The proposed model is computationally efficient and uses only summary statistics. In addition, it corrects for the presence of overlapping genes and linkage disequilibrium (LD). Via simulated and real GWAS data, we showed our model improved power over currently available pathway analysis methods while preserving type I error rate. Furthermore, using the WTCCC Type 1 Diabetes (T1D) dataset, we demonstrated mixed model analysis identified meaningful biological processes that agreed well with previous reports on T1D. Therefore, the proposed methodology provides an efficient statistical modeling framework for systems analysis of GWAS.

Availability: The software code for mixed models analysis is freely available at http://biostat.mc.vanderbilt.edu/LilyWang.

Contact:  lily.wang@vanderbilt.edu; zhongming.zhao@vanderbilt.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Classifying short gene expression time-courses with Bayesian estimation of piecewise constant functions
Authors: Hafemeister Christoph , Costa Ivan G. , Schönhuth Alexander , Schliep Alexander
Published: January 2011

Motivation: Analyzing short time-courses is a frequent and relevant problem in molecular biology, as, for example, 90% of gene expression time-course experiments span at most nine time-points. The biological or clinical questions addressed are elucidating gene regulation by identification of co-expressed genes, predicting response to treatment in clinical, trial-like settings or classifying novel toxic compounds based on similarity of gene expression time-courses to those of known toxic compounds. The latter problem is characterized by irregular and infrequent sample times and a total lack of prior assumptions about the incoming query, which comes in stark contrast to clinical settings and requires to implicitly perform a local, gapped alignment of time series. The current state-of-the-art method (SCOW) uses a variant of dynamic time warping and models time series as higher order polynomials (splines).

Results: We suggest to model time-courses monitoring response to toxins by piecewise constant functions, which are modeled as left–right Hidden Markov Models. A Bayesian approach to parameter estimation and inference helps to cope with the short, but highly multivariate time-courses. We improve prediction accuracy by 7% and 4%, respectively, when classifying toxicology and stress response data. We also reduce running times by at least a factor of 140; note that reasonable running times are crucial when classifying response to toxins. In conclusion, we have demonstrated that appropriate reduction of model complexity can result in substantial improvements both in classification performance and running time.

Availability: A Python package implementing the methods described is freely available under the GPL from http://bioinformatics.rutgers.edu/Software/MVQueries/.

Contact:  hafemeis@molgen.mpg.de; igcf@cin.ufpe.br; schliep@cs.rutgers.edu;

Supplementary information:  Supplementary data are available at Bioinformatics online.
Origin of invasive Florida frogs traced to Cuba
Authors: Heinicke Matthew P. , Diaz Luis M. , Hedges S. Blair
Published: January 2011

Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin ofE. planirostristo a small area in western Cuba, whileO. septentrionalisis derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent.
Confirmation of right whales near a nineteenth-century whaling ground east of southern Greenland
Authors: Mellinger David K. , Nieukirk Sharon L. , Klinck Karolin , Klinck Holger , Dziak Robert P. , Clapham Phillip J. , Brandsdóttir Bryndís
Published: January 2011

North Atlantic right whales (Eubalaena glacialis) were found in an important nineteenth century whaling area east of southern Greenland, from which they were once thought to have been extirpated. In 2007–2008, a 1-year passive acoustic survey was conducted at five sites in and near the ‘Cape Farewell Ground’, the former whaling ground. Over 2000 right whale calls were recorded at these sites, primarily during July–November. Most calls were northwest of the historic ground, suggesting a broader range in this region than previously known. Geographical and temporal separation of calls confirms use of this area by multiple animals.
Comparative analysis of European wide marine ecosystem shifts: a large-scale approach for developing the basis for ecosystem-based management
Authors: Möllmann Christian , Conversi Alessandra , Edwards Martin
Published: January 2011

Abrupt and rapid ecosystem shifts (where major reorganizations of food-web and community structures occur), commonly termed regime shifts, are changes between contrasting and persisting states of ecosystem structure and function. These shifts have been increasingly reported for exploited marine ecosystems around the world from the North Pacific to the North Atlantic. Understanding the drivers and mechanisms leading to marine ecosystem shifts is crucial in developing adaptive management strategies to achieve sustainable exploitation of marine ecosystems. An international workshop on a comparative approach to analysing these marine ecosystem shifts was held at Hamburg University, Institute for Hydrobiology and Fisheries Science, Germany on 1–3 November 2010. Twenty-seven scientists from 14 countries attended the meeting, representing specialists from seven marine regions, including the Baltic Sea, the North Sea, the Barents Sea, the Black Sea, the Mediterranean Sea, the Bay of Biscay and the Scotian Shelf off the Canadian East coast. The goal of the workshop was to conduct the first large-scale comparison of marine ecosystem regime shifts across multiple regional areas, in order to support the development of ecosystem-based management strategies.
On a bifurcation structure mimicking period adding
Authors: Schenke Björn , Avrutin Viktor , Schanz Michael
Published: January 2011

In this work, we investigate a piecewise-linear discontinuous scalar map defined on three partitions. This map is specifically constructed in such a way that it shows a recently discovered bifurcation scenario in its pure form. Owing to its structure on the one hand and the similarities to the nested period-adding scenario on the other hand, we denoted the new bifurcation scenario as nested period-incrementing bifurcation scenario. The new bifurcation scenario occurs in several physical and electronical systems but usually not isolated, which makes the description complicated. By isolating the scenario and using a suitable symbolic description for the asymptotically stable periodic orbits, we derive a set of rules in the space of symbolic sequences that explain the structure of the stable periodic domain in the parameter space entirely. Hence, the presented work is a necessary step for the understanding of the more complicated bifurcation scenarios mentioned above.
A ballistic-diffusive heat conduction model extracted from Boltzmann transport equation
Authors: Xu Mingtian , Hu Haiyan
Published: January 2011

A ballistic-diffusive heat conduction model is derived from the Boltzmann transport equation by a coarse-graining approach developed in the present study. By taking into account of the lagging effect, this model avoids the infinite heat propagation speed implied by the classical Fourier law. By expressing the heat conductivity as a function of the Knudsen number, it accounts for the size effect of the nanoscale heat conduction. The variation of the obtained effective heat conductivity with respect to the characteristic length shows an agreement with the experimental results for thin silicon films and nanowires in the nanoscale regime.
An island paradigm on the mainland: host population fragmentation impairs the community of avian pathogens
Authors: Vögeli Matthias , Lemus Jesús A. , Serrano David , Blanco Guillermo , Tella José L.
Published: January 2011

Emergent infectious diseases represent a major threat for biodiversity in fragmented habitat networks, but their dynamics in host metapopulations remain largely unexplored. We studied a large community of pathogens (including 26 haematozoans, bacteria and viruses as determined through polymerase chain reaction assays) in a highly fragmented mainland bird metapopulation. Contrary to recent studies, which have established that the prevalence of pathogens increase with habitat fragmentation owing to crowding and habitat-edge effects, the analysed pathogen parameters were neither dependent on host densities nor related to the spatial structure of the metapopulation. We provide, to our knowledge, the first empirical evidence for a positive effect of host population size on pathogen prevalence, richness and diversity. These new insights into the interplay between habitat fragmentation and pathogens reveal properties of a host–pathogen system resembling island environments, suggesting that severe habitat loss and fragmentation could lower pathogen pressure in small populations.
Paradoxical persistence through mixed-system dynamics: towards a unified perspective of reversal behaviours in evolutionary ecology
Authors: Williams Paul David , Hastings Alan
Published: January 2011

Counterintuitive dynamics of various biological phenomena occur when composite system dynamics differ qualitatively from that of their component systems. Such composite systems typically arise when modelling situations with time-varying biotic or abiotic conditions, and examples range from metapopulation dynamics to population genetic models. These biological, and related physical, phenomena can often be modelled as simple financial games, wherein capital is gained and lost through gambling. Such games have been developed and used as heuristic devices to elucidate the processes at work in generating seemingly paradoxical outcomes across a spectrum of disciplines, albeit in a field-specific, ad hoc fashion. Here, we propose that studying these simple games can provide a much deeper understanding of the fundamental principles governing paradoxical behaviours in models from a diversity of topics in evolution and ecology in which fluctuating environmental effects, whether deterministic or stochastic, are an essential aspect of the phenomenon of interest. Of particular note, we find that, for a broad class of models, the ecological concept of equilibrium reactivity provides an intuitive necessary condition that must be satisfied in order for environmental variability to promote population persistence. We contend that further investigations along these lines promise to unify aspects of the study of a range of topics, bringing questions from genetics, species persistence and coexistence and the evolution of bet-hedging strategies, under a common theoretical purview.
Phylogeny and palaeoecology of
Polyommatus
blue butterflies show Beringia was a climate-regulated gateway to the New World
Authors: Vila Roger , Bell Charles D. , Macniven Richard , Goldman-Huertas Benjamin , Ree Richard H. , Marshall Charles R. , Bálint Zsolt , Johnson Kurt , Benyamini Dubi , Pierce Naomi E.
Published: January 2011

Transcontinental dispersals by organisms usually represent improbable events that constitute a major challenge for biogeographers. By integrating molecular phylogeny, historical biogeography and palaeoecology, we test a bold hypothesis proposed by Vladimir Nabokov regarding the origin of Neotropical
Polyommatus
blue butterflies, and show that Beringia has served as a biological corridor for the dispersal of these insects from Asia into the New World. We present a novel method to estimate ancestral temperature tolerances using distribution range limits of extant organisms, and find that climatic conditions in Beringia acted as a decisive filter in determining which taxa crossed into the New World during five separate invasions over the past 11 Myr. Our results reveal a marked effect of the Miocene–Pleistocene global cooling, and demonstrate that palaeoclimatic conditions left a strong signal on the ecology of present-day taxa in the New World. The phylogenetic conservatism in thermal tolerances that we have identified may permit the reconstruction of the palaeoecology of ancestral organisms, especially mobile taxa that can easily escape from hostile environments rather than adapt to them.
A small increase in UV-B increases the susceptibility of tadpoles to predation
Authors: Alton Lesley A. , Wilson Robbie S. , Franklin Craig E.
Published: January 2011

Increased ultraviolet-B (UV-B) radiation as a consequence of ozone depletion is one of the many potential drivers of ongoing global amphibian declines. Both alone and in combination with other environmental stressors, UV-B is known to have detrimental effects on the early life stages of amphibians, but our understanding of the fitness consequences of these effects remains superficial. We examined the independent and interactive effects of UV-B and predatory chemical cues (PCC) on a suite of traits ofLimnodynastes peroniiembryos and tadpoles, and assessed tadpole survival time in a predator environment to evaluate the potential fitness consequences. Exposure to a 3 to 6 per cent increase in UV-B, which is comparable to changes in terrestrial UV-B associated with ozone depletion, had no effect on any of the traits measured, except survival time in a predator environment, which was reduced by 22 to 28 per cent. Exposure to PCC caused tadpoles to hatch earlier, have reduced hatching success, have improved locomotor performance and survive for longer in a predator environment, but had no effect on tadpole survival, behaviour or morphology. Simultaneous exposure to UV-B and PCC resulted in no interactive effects. These findings demonstrate that increased UV-B has the potential to reduce tadpole fitness, while exposure to PCCs improves their fitness.
Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks
Authors: Kozak Genevieve M. , Head Megan L. , Boughman Janette W.
Published: January 2011

During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such ‘magic traits’ easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics:Gasterosteusspp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.
Using knockout mutants to reveal the growth costs of defensive traits
Authors: Züst Tobias , Joseph Bindu , Shimizu Kentaro K. , Kliebenstein Daniel J. , Turnbull Lindsay A.
Published: January 2011

We used a selection of
Arabidopsis thaliana
mutants with knockouts in defence genes to demonstrate growth costs of trichome development and glucosinolate production. Four of the seven defence mutants had significantly higher size-standardized growth rates (SGRs) than the wild-type in early life, although this benefit declined as plants grew larger. SGR is known to be a good predictor of success under high-density conditions, and we confirmed that mutants with higher growth rates had a large advantage when grown in competition. Despite the lack of differences in flowering-time genes, the mutants differed in flowering time, a trait that strongly correlated with early growth rate. Aphid herbivory decreased plant growth rate and increased flowering time, and aphid population growth rate was closely coupled to the growth rate of the host plant. Small differences in early SGR thus had cascading effects on both flowering time and herbivore populations.
Adaptation improves discrimination of face identity
Authors: Oruç Ipek , Barton Jason J. S.
Published: January 2011

Whether face adaptation confers any advantages to perceptual processing remains an open question. We investigated whether face adaptation can enhance the ability to make fine discriminations in the vicinity of the adapted face. We compared face discrimination thresholds in three adapting conditions: (i) same-face: where adapting and test faces were the same, (ii) different-face: where adapting and test faces differed, and (iii) baseline: where the adapting stimulus was a blank. Discrimination thresholds for morphed identity changes involving the adapted face (same-face) improved compared with those from both the baseline (no-adaptation) and different-face conditions. Since adapting to a face did not alter discrimination performance for other faces, this effect is selective for the facial identity that is adapted. These results indicate a form of gain control to heighten perceptual sensitivity in the vicinity of a currently viewed face, analogous to forms of adaptive gain control at lower levels of the visual system.
Intra-guild competition and its implications for one of the biggest terrestrial predators,
Tyrannosaurus rex
Authors: Carbone Chris , Turvey Samuel T. , Bielby Jon
Published: January 2011

Identifying tradeoffs between hunting and scavenging in an ecological context is important for understanding predatory guilds. In the past century, the feeding strategy of one of the largest and best-known terrestrial carnivores,
Tyrannosaurus rex
, has been the subject of much debate: was it an active predator or an obligate scavenger? Here we look at the feasibility of an adult
T. rex
being an obligate scavenger in the environmental conditions of Late Cretaceous North America, given the size distributions of sympatric herbivorous dinosaurs and likely competition with more abundant small-bodied theropods. We predict that nearly 50 per cent of herbivores would have been within a 55–85 kg range, and calculate based on expected encounter rates that carcasses from these individuals would have been quickly consumed by smaller theropods. Larger carcasses would have been very rare and heavily competed for, making them an unreliable food source. The potential carcass search rates of smaller theropods are predicted to be 14–60 times that of an adult
T. rex
. Our results suggest that
T. rex
and other extremely large carnivorous dinosaurs would have been unable to compete as obligate scavengers and would have primarily hunted large vertebrate prey, similar to many large mammalian carnivores in modern-day ecosystems.
Parasitoids select plants more heavily infested with their caterpillar hosts: a new approach to aid interpretation of plant headspace volatiles
Authors: Girling Robbie D. , Stewart-Jones Alex , Dherbecourt Julie , Staley Joanna T. , Wright Denis J. , Poppy Guy M.
Published: January 2011

Plants produce volatile organic compounds (VOCs) in response to herbivore attack, and these VOCs can be used by parasitoids of the herbivore as host location cues. We investigated the behavioural responses of the parasitoid
Cotesia vestalis
to VOCs from a plant–herbivore complex consisting of cabbage plants (
Brassica oleracea
) and the parasitoids host caterpillar,
Plutella xylostella
. A Y-tube olfactometer was used to compare the parasitoids' responses to VOCs produced as a result of different levels of attack by the caterpillar and equivalent levels of mechanical damage. Headspace VOC production by these plant treatments was examined using gas chromatography–mass spectrometry.
Cotesia vestalis
were able to exploit quantitative and qualitative differences in volatile emissions, from the plant–herbivore complex, produced as a result of different numbers of herbivores feeding.
Cotesia vestalis
showed a preference for plants with more herbivores and herbivore damage, but did not distinguish between different levels of mechanical damage. Volatile profiles of plants with different levels of herbivores/herbivore damage could also be separated by canonical discriminant analyses. Analyses revealed a number of compounds whose emission increased significantly with herbivore load, and these VOCs may be particularly good indicators of herbivore number, as the parasitoid processes cues from its external environment.
Seventy Million Years of Concerted Evolution of a Homoeologous Chromosome Pair, in Parallel, in Major Poaceae Lineages
Authors: Wang Xiyin , Tang Haibao , Paterson Andrew H.
Published: January 2011

Whole genome duplication ~70 million years ago provided raw material for Poaceae (grass) diversification. Comparison of rice (Oryza sativa), sorghum (Sorghum bicolor), maize (Zea mays), and Brachypodium distachyon genomes revealed that one paleo-duplicated chromosome pair has experienced very different evolution than all the others. For tens of millions of years, the two chromosomes have experienced illegitimate recombination that has been temporally restricted in a stepwise manner, producing structural stratification in the chromosomes. These strata formed independently in different grass lineages, with their similarities (low sequence divergence between paleo-duplicated genes) preserved in parallel for millions of years since the divergence of these lineages. The pericentromeric region of this homeologous chromosome pair accounts for two-thirds of the gene content differences between the modern chromosomes. Both intriguing and perplexing is a distal chromosomal region with the greatest DNA similarity between surviving duplicated genes but also with the highest concentration of lineage-specific gene pairs found anywhere in these genomes and with a significantly elevated gene evolutionary rate. Intragenomic similarity near this chromosomal terminus may be important in hom(e)ologous chromosome pairing. Chromosome structural stratification, together with enrichment of autoimmune response–related (nucleotide binding site–leucine-rich repeat) genes and accelerated DNA rearrangement and gene loss, confer a striking resemblance of this grass chromosome pair to the sex chromosomes of other taxa.
SNP‐based association mapping of Arachnomelia in Fleckvieh cattle
Authors: Seichter D. , Russ I. , Förster M. , Medugorac I.
Published: January 2011

Bovine arachnomelia is an inherited congenital disorder with malformation mainly of the limbs, the vertebral column and the skull, following a monogenic autosomal recessive heredity. Despite almost identical pathological findings, arachnomelia has previously been mapped to bovine chromosome 23 and 5 in Fleckvieh and Braunvieh respectively. Therefore, this disorder may be an example of locus heterogeneity in cattle. This study aimed to refine the candidate region to allow positional cloning and sequence analyses of candidate genes in Fleckvieh cattle. For that purpose, a case‐control association mapping design was set up with a case group of 16 pre‐selected affected individuals and a control group of 50 unrelated animals. The subset of affected animals was selected from a total of 129 pathologically confirmed cases due to the occurrence of recombination(s) within a 14.5 cM candidate interval previously mapped to chromosome 23. Six linked microsatellites currently used for indirect gene testing in Fleckvieh were analysed for this purpose. In all selected cases, a genome‐wide scan using 44 473 informative SNPs revealed shared segments of homozygosity at 15 adjacent SNPs on chromosome 23. Additional haplotype analysis of 37 carrier bulls confirmed the localization of the arachnomelia locus to a region of 927 kb (13.622–14.549 Mb) containing molybdenum cofactor biosynthesis protein 1 gene, the most likely candidate gene for arachnomelia in Fleckvieh. The number of recombinant haplotypes observed in cases was more than doubled compared with the number of expected recombinations. This remarkably increased mapping resolution and thus illustrates the benefit of pre‐selection in association studies.
Local geographic range predicts freshwater fish extinctions in Singapore
Authors: Giam Xingli , Ng Ting Hui , Lok Alvin F. S. L. , Ng Heok Hee
Published: January 2011

1. Identifying the ecological and life‐history correlates of local extinction may elucidate mechanisms by which species traits and the environment interact to result in extinctions, and will help to predict and target extinction‐prone species for inclusion in conservation programmes. Freshwater habitats are known to be highly threatened in Southeast Asia but the correlates of extinction among tropical freshwater fish remains unclear.

2. To bridge this knowledge gap, we examined extinction correlates of the freshwater fish of Singapore using machine learning methods: conditional inference trees and forests. Singapore is an ideal study site as it has experienced a high degree of habitat loss and has a well‐studied ichthyofauna compared with other countries in the region.

3. The local range of a species was the only significant predictor of extinctions: range‐restricted species were more likely to go extinct.

4. Other traits found to be important predictors of extinction risk in temperate regions or hypothesized to predict extinctions based on theory included regional geographic distribution, vertical position, feeding guild, body size, number of congeners, air‐breathing capability and habitat preference. These factors did not appear to drive extinctions of freshwater fish in Singapore, although forest‐dependent species are more likely to have a restricted local range.

5. Synthesis and applications. Local extinctions of freshwater fish in Singapore are random with respect to ecological and life‐history traits because habitat loss is responsible for the removal of entire populations. The fish fauna of Southeast Asia is so poorly known that intensive field surveys are required to identify hotspots of freshwater fish endemism which may be vulnerable to future extinction. These hotspots should then be incorporated into national conservation plans. Where complete habitat protection is not possible, for example, in existing logging concessions and plantations, local authorities should establish partnerships with management companies to ameliorate impacts on fish fauna. Within Singapore, the Nee Soon Swamp Forest is one such hotspot of fish endemism and must be conserved to protect the last populations of five fish species endemic to this location on the island.
Effect of biodiversity on economic benefits from communal lands in Namibia
Authors: Naidoo Robin , Weaver L. Chris , Stuart‐Hill Greg , Tagg Jo
Published: January 2011

1. The conservation of biodiversity is increasingly justified by claims that human livelihoods are improved through its protection. Nature’s ecosystem services do indeed benefit people, but how necessary is a diversity of living things to provide these services? Most studies cited as addressing this question in natural systems do not actually quantify relevant metrics (e.g. species richness) and assess their relationship with services and/or economic benefits. On the other hand, numerous small‐scale experimental studies have demonstrated that more diverse systems do indeed tend to function better, but the relevance of these results to much larger, more complex socio‐ecological systems is unclear.

2. Here, we investigate how biodiversity affects the gains from two ecosystem services, trophy hunting and ecotourism, in communal conservancies of Namibia, an arid country in southern Africa. We used statistical methods to explicitly control for confounding variables so that the effect of biodiversity per se on financial benefits to local communities was isolated.

3. Our results show that biodiversity exerts a positive effect on the economic benefits generated from these two ecosystem services produced on communal lands in Namibia. The richness of large wildlife species is positively related to income derived from ecotourism and trophy hunting after statistically controlling for potentially confounding variables such as a conservancy’s geographic characteristics and human population size.

4. Synthesis and applications. Our results demonstrate that the conservation of biodiversity can indeed generate increased services from real‐world ecosystems, in this case for the benefit of impoverished rural communities in sub‐Saharan Africa. More such studies are needed from various ecological and socioeconomic contexts in order to boost the evidence base for positive effects of biodiversity on ecosystem services.
Ecosystem management based on natural disturbances: hierarchical context and non‐equilibrium paradigm
Authors: Mori Akira S.
Published: January 2011

1. Maintenance of ecological integrity and biodiversity must be based on well‐grounded principles of disturbance ecology. However, non‐equilibrium aspects of ecosystems, such as unpredictability, instability and stochasticity due to various natural disturbances, have not been satisfactorily integrated into practical application. Failure to acknowledge the dynamic nature of systems will inevitably lead to unexpected changes and unachieved conservation goals.

2. This review discusses non‐equilibrium ecology in terms of natural disturbances and the conservation and management of terrestrial ecosystems and landscapes.

3. Several key components, which require further ecological consideration, are specifically discussed. These include the hierarchical disturbance regime, disturbance legacy, multiple post‐disturbance pathways, climate instability, spatial and temporal variability, and resilience.

4. Natural disturbance regimes are complex and difficult to define. This is because some disturbances can be nested, and they interact with other qualitatively and quantitatively different disturbances, constituting a hierarchy of natural disturbances. Large temporal and spatial perspectives are therefore required to incorporate the hierarchical context of natural disturbance regimes into regional management plans.

5. Conservation managers may often seek some kind of dynamic equilibrium based on protection of species and seral stages from extinction. However, because climate instability interrupts any shift toward an equilibrium, most terrestrial vegetation systems are inherently prone to large environmental changes and diverse disturbances, and thus, are dynamic and non‐equilibrating.

6. Synthesis and applications.Resiliency is the key to conserving ecological integrity via the ability to cope with inevitable changes. As long as ecosystems are resilient and disturbances are natural, we should not impede natural shifts in disturbance regimes and resultant ecosystem changes, even if changes are abrupt and unpredictable and thus have large consequences. If ecological resilience has already been eroded by humans, it is important that resilience should be enhanced by restoring keystone features of vegetation systems to prevent disturbance‐induced undesirable ecosystem degradation.
Development of a specific molecular tool for detecting Xanthomonas campestris pv. musacearum
Authors: Adikini S. , Tripathi L. , Beed F. , Tusiime G. , Magembe E. M. , Kim D. J.
Published: January 2011

A specific and rapid diagnostic tool has been developed to detect Xanthomonas campestris pv. musacearum, the causal agent of bacterial wilt of banana. PCR primers were developed from intergenic regions of X. campestris pv. musacearum following its partial sequence. A total of 48 primers were tested for specificity to X. campestris pv. musacearum strains collected from various regions in Uganda. These were also tested for specificity against related Xanthomonas species from the vasicola group, Xanthomonas species pathogenic to other crops, and against those existing saprophytically on banana plants. Seven primer sets (Xcm12, Xcm35, Xcm36, Xcm38, Xcm44, Xcm47 and Xcm48) were found to be very specific to X. campestris pv. musacearum. These primer sets directed the amplification of the expected product for all 52 strains of X. campestris pv. musacearum collected from different locations in Uganda. No amplification products were obtained with unrelated phytopathogenic bacteria or endophytic/epiphytic bacteria from banana. A detection limit of 103 CFU mL−1 corresponding to about four cells per PCR reaction was observed when X. campestris pv. musacearum cells were used for all the seven primer sets. The DNA samples from symptomless plant tissues also tested positive with primer set Xcm38. The specific PCR method described here is a valuable diagnostic tool which can be used to detect the pathogen at early stages of infection and monitor disease.
Infection processes and soft wheat response to root rot and crown rot caused by Fusarium culmorum
Authors: Beccari G. , Covarelli L. , Nicholson P.
Published: January 2011

An isolate of the fungus Fusarium culmorum constitutively expressing green fluorescent protein was used to investigate the infection process and host response of primary seedling roots and stem base leaf sheaths of soft wheat cv. Genio. Disease progress was assessed macroscopically by visual symptoms, microscopically by confocal laser scanning microscopy (CLSM) and via gene expression analysis of fungal and wheat genes by real‐time quantitative RT‐PCR. In the roots, CLSM investigations revealed an initial intercellular and subsequent intracellular colonization by fungal hyphae. The fungus invaded the rhizodermal layer and cortex but was not seen to colonize the stele. The fungus consistently expressed TRI5 (24, 48 and 96 h post‐inoculation), indicating that trichothecenes were being synthesized throughout this phase of infection and colonization. The expression of the six host defence‐associated genes (Wheatwin 1‐2, PR1, Chitinase, PAL, WIR1 and LOX) increased early in infection and decreased during later stages. In the stem base, CLSM observations revealed the fungus sequentially penetrating though the first, second and third basal leaf sheaths. Expression of TRI5 was initiated early in the infection of each leaf sheath. The expression of the host defence‐associated genes varied over time and across leaf sheaths, and all were also expressed in leaf sheaths which had not yet been in contact with the fungus. Expression of LOX and WIR1 were particularly enhanced in the third leaf sheath.