bluuebunny/crossref_metadata_2025 huggingface dataset:
Function of leafy sepals in Paris polyphylla: photosynthate allocation and partitioning to the fruit and rhizome
Authors: Yu Kun , Fan Qilong , Wang Yan , Wei Jianrong , Ma Qing , Yu Dan , Li Jiaru
Published: November 2012

Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. is a rhizomatous, herbaceous, perennial plant that is used as a medicinal plant with a variety of pharmacological activities. However, the functions of the green, leafy sepal of this plant are poorly understood. The main objectives of this study were to: (a) test the hypothesis that sepals make measurable contributions to fruit development and rhizome growth; and (b) investigate the allocation and partitioning of photosynthates produced by sepals and leaves to fruit and rhizome. Net photosynthetic rate, photosynthetic pigment composition and δ13C values were similar for sepals and leaves. Sepal-darkening and sepal-removal treatments resulted in smaller fruit size and decreased rhizome biomass, whereas fruit removal led to a decrease in calyx size and an increase in rhizome yield and saponin content. Fruit and seed mass were positively and linearly related to calyx size. These results indicate that photosynthates produced by sepals are involved in the fruit growth and seed development and that developing fruit and rhizomes compete for the photosynthates exported by leaves. We propose that the sepals of P. polyphylla function partly as leaves to compensate for reproductive costs. Fruit removal increased carbon partitioning to the rhizome and improved rhizome yield and quality, offering a useful strategy for the domestication of this valuable medicinal plant.
Recreational fishing selectively captures individuals with the highest fitness potential
Authors: Sutter David A. H. , Suski Cory D. , Philipp David P. , Klefoth Thomas , Wahl David H. , Kersten Petra , Cooke Steven J. , Arlinghaus Robert
Published: December 2012

Fisheries-induced evolution and its impact on the productivity of exploited fish stocks remains a highly contested research topic in applied fish evolution and fisheries science. Although many quantitative models assume that larger, more fecund fish are preferentially removed by fishing, there is no empirical evidence describing the relationship between vulnerability to capture and individual reproductive fitness in the wild. Using males from two lines of largemouth bass (
Micropterus salmoides
) selectively bred over three generations for either high (HV) or low (LV) vulnerability to angling as a model system, we show that the trait “vulnerability to angling” positively correlates with aggression, intensity of parental care, and reproductive fitness. The difference in reproductive fitness between HV and LV fish was particularly evident among larger males, which are also the preferred mating partners of females. Our study constitutes experimental evidence that recreational angling selectively captures individuals with the highest potential for reproductive fitness. Our study further suggests that selective removal of the fittest individuals likely occurs in many fisheries that target species engaged in parental care. As a result, depending on the ecological context, angling-induced selection may have negative consequences for recruitment within wild populations of largemouth bass and possibly other exploited species in which behavioral patterns that determine fitness, such as aggression or parental care, also affect their vulnerability to fishing gear.
Interactions between the nucleosome histone core and Arp8 in the INO80 chromatin remodeling complex
Authors: Saravanan Matheshwaran , Wuerges Jochen , Bose Daniel , McCormack Elizabeth A. , Cook Nicola J. , Zhang Xiaodong , Wigley Dale B.
Published: December 2012

Actin-related protein Arp8 is a component of the INO80 chromatin remodeling complex. Yeast Arp8 (yArp8) comprises two domains: a 25-KDa N-terminal domain, found only in yeast, and a 75-KDa C-terminal domain (yArp8CTD) that contains the actin fold and is conserved across other species. The crystal structure shows that yArp8CTD contains three insertions within the actin core. Using a combination of biochemistry and EM, we show that Arp8 forms a complex with nucleosomes, and that the principal interactions are via the H3 and H4 histones, mediated through one of the yArp8 insertions. We show that recombinant yArp8 exists in monomeric and dimeric states, but the dimer is the biologically relevant form required for stable interactions with histones that exploits the twofold symmetry of the nucleosome core. Taken together, these data provide unique insight into the stoichiometry, architecture, and molecular interactions between components of the INO80 remodeling complex and nucleosomes, providing a first step toward building up the structure of the complex.
Neural and behavioral bases of age differences in perceptions of trust
Authors: Castle Elizabeth , Eisenberger Naomi I. , Seeman Teresa E. , Moons Wesley G. , Boggero Ian A. , Grinblatt Mark S. , Taylor Shelley E.
Published: December 2012

Older adults are disproportionately vulnerable to fraud, and federal agencies have speculated that excessive trust explains their greater vulnerability. Two studies, one behavioral and one using neuroimaging methodology, identified age differences in trust and their neural underpinnings. Older and younger adults rated faces high in trust cues similarly, but older adults perceived faces with cues to untrustworthiness to be significantly more trustworthy and approachable than younger adults. This age-related pattern was mirrored in neural activation to cues of trustworthiness. Whereas younger adults showed greater anterior insula activation to untrustworthy versus trustworthy faces, older adults showed muted activation of the anterior insula to untrustworthy faces. The insula has been shown to support interoceptive awareness that forms the basis of “gut feelings,” which represent expected risk and predict risk-avoidant behavior. Thus, a diminished “gut” response to cues of untrustworthiness may partially underlie older adults’ vulnerability to fraud.
Acute ethanol responses in
Drosophila
are sexually dimorphic
Authors: Devineni Anita V. , Heberlein Ulrike
Published: December 2012

In mammalian and insect models of ethanol intoxication, low doses of ethanol stimulate locomotor activity whereas high doses induce sedation. Sex differences in acute ethanol responses, which occur in humans, have not been characterized in
Drosophila
. In this study, we find that male flies show increased ethanol hyperactivity and greater resistance to ethanol sedation compared with females. We show that the sex determination gene
transformer
(
tra
) acts in the developing nervous system, likely through regulation of
fruitless
(
fru
), to at least partially mediate the sexual dimorphism in ethanol sedation. Although pharmacokinetic differences may contribute to the increased sedation sensitivity of females, neuronal
tra
expression regulates ethanol sedation independently of ethanol pharmacokinetics. We also show that acute activation of
fru
-expressing neurons affects ethanol sedation, further supporting a role for
fru
in regulating this behavior. Thus, we have characterized previously undescribed sex differences in behavioral responses to ethanol, and implicated fru in mediating a subset of these differences.
The “image bite,” political language, and the public/private divide
Authors: Kaufer David , Parry-Giles Shawn J. , Klebanov Beata Beigman
Published: November 2012

Voice-overs with muted images, often known as the “image bite,” have become an increasingly used but understudied format of political language by the television news media. Because the media can use images to fit many contexts and purposes of commentary, the media images are susceptible to continuous de-contextualization and re-contextualization. Drawing from theories of feminist critical discourse analysis and gender performance as well as scholarship on the public/private divide, we examine the commentary of one U.S. television news organization’s (NBC) re-contextualization of the same stock footage of Hillary Clinton over 10 newscasts spanning 20 months from August 1998 to June of 2000. NBC re-enforces the public/private binary in conventional masculine terms. Yet it also worked, at times, to unify the binary when covering Hillary Clinton’s U.S. Senate campaign; on those occasions at least, NBC revealed the potential erosion of gender stereotypes and a small but still significant role for human agency in the study of gender ideology.
The phonetics of insertional code-switching
Authors: Olson Daniel
Published: December 2012

This study investigates the phonetic production of Spanish-English insertional code-switches, constituents of an embedded language inserted within a discourse of a matrix language. While previous research on the phonetics of codeswitching has focused exclusively on the segmental properties, the current study provides a detailed examination of the suprasegmental features of code-switched tokens, including pitch height and duration. Code-switched productions are compared with non-code-switched tokens, and results indicate that insertional code-switched tokens are produced with a degree of hyper-articulation, evidenced by an increase in pitch height and duration. The results are discussed within Hyper- and Hypo-articulation Theory, drawing on the notion of a decreased local probability incurred by insertional code-switches.
Frequencies, probabilities, and association measures in usage-/exemplar-based linguistics
Authors: Gries Stefan Th.
Published: December 2012

In the last few years, a particular quantitative approach to the syntax-lexis interface has been developed: collostructional analysis (CA). This approach is an application of association measures to co-occurrence data from corpora, from a usage-based/cognitive-linguistic perspective. In spite of some popularity, this approach has come under criticism in Bybee (2010), who criticizes the method for several perceived shortcomings and advocates the use of raw frequencies/percentages instead. This paper has two main objectives. The first is to refute Bybee’s criticism on theoretical and empirical grounds; the second and further-reaching one is to outline, on the basis of what frequency data really look like, a cline of analytical approaches and, ultimately, a new perspective on the notion of construction based on this cline.
The semantics of definite expressions and the grammaticalization of THE
Authors: Gisborne Nikolas
Published: December 2012

This paper explores the claim that definite expressions involve universal and existential quantification from the point of view of Word Grammar, in order to establish whether the quantificational view of definiteness is compatible with a particular cognitive theory of language, and to see how it compares with the familiarity treatment of definiteness. It is argued that the quantificational approach is superior to the familiarity approach in the analysis of a number of linguistic phenomena, and a number of Word Grammar analyses are presented. The paper concludes with an investigation into the grammaticalization of the English definite article, in order to compare the merits of the two approaches, and argues that the quantificational approach delivers a simpler and preferable account.
Smashing new results on aspectual framing
Authors: Matlock Teenie , Sparks David , Matthews Justin L. , Hunter Jeremy , Huette Stephanie
Published: December 2012

How do people describe events they have witnessed? What role does linguistic aspect play in this process? To provide answers to these questions, we conducted an experiment on aspectual framing. In our task, people were asked to view videotaped vehicular accidents and to describe what happened (perfective framing) or what was happening (imperfective framing). Our analyses of speech and gesture in retellings show that the form of aspect used in the question differentially influenced the way people conceptualized and described actions. Questions framed with imperfective aspect resulted in more motion verbs (e.g. driving), more reckless language (e.g. speeding), and more iconic gestures (e.g. path gesture away from the body to show travel direction) than did questions framed with perfective aspect. Our research contributes novel insights on aspect and the construal of events, and on the semantic potency of aspect in leading questions. The findings are consistent with core assumptions in cognitive linguistics, including the proposal that linguistic meaning, including grammatical meaning, is dynamic and grounded in perceptual and cognitive experience.
Hydrogen Peroxide Treatments Administered to Hatchery-Reared Burbot: Assessing Treatment Regimes from Embryonic Development through Juvenile Rearing
Authors: Polinski Mark P , Jensen Nathan R , Foltz John , Ireland Susan C , Cain Kenneth D
Published: December 2012

Burbot Lota lota is an emerging aquaculture species, in which fungal infestations during early life stage development are common. In this study, the tolerance of Burbot to external hydrogen peroxide (H2O2) treatment regimes was examined during four early life stages to determine species and life stage-specific sensitivity. Yolk-sac larvae tolerated three 1-h treatments up to 250 μL/L H2O2 without significant reduction in survival. Preflexion larvae tolerated only 100 μL/L H2O2 before survival was affected. In both cases, decreased survival was only observed after administration of three consecutive treatments. Flexion larvae tolerated up to 250 μL/L H2O2, but by the juvenile stage sensitivity again increased to 100 μL/L H2O2 before survival was affected. In these latter stages, decreased survival was observed immediately following the first H2O2 treatment, suggesting a mechanism for toxicity that is different than that in previous life stages. As has previously been shown, H2O2 can be effective for controlling aquatic bacteria and fungus at or below 250 μL/L, and our results indicate that H2O2 concentrations currently used during Burbot egg incubation may be extended into the larval rearing stage for effective fungal control without negatively affecting survival of either eggs or newly hatched larvae. Additionally, treatment regimes may be continued through juvenile development for the purpose of controlling external pathogens in the hatchery production of Burbot.
Histological Analysis Reveals Larger Size at Maturity for Southern Flounder with Implications for Biological Reference Points
Authors: Midway Stephen R. , Scharf Frederick S.
Published: December 2012

For fish stocks managed using biological reference points based upon spawning biomass, it is critical to have accurate maturity schedules. We investigated size- and age-dependent patterns in maturity for southern flounder Paralichthys lethostigma, a flatfish supporting valuable coastal fisheries in North Carolina and throughout its range. We evaluated both macroscopic and histological methods over two consecutive reproductive seasons. Histological analyses revealed that maturity occurred at larger sizes and older ages than previously estimated. Length at 50% maturity (L  50) was estimated at 408 mm total length (TL), which was more than 60 mm larger than currently assumed, and was relatively stable between study years. We found that only 44% of age-1 southern flounder were mature compared with an estimated 74% in an earlier study. We suspect that most of the differences in maturity timing of southern flounder between our findings and previous studies stem from macroscopic assignment error. During this study, only 61% of fish staged macroscopically as developing were found to be mature based on histological analysis. Assuming incorrectly that all of these fish were mature would have resulted in an L  50 of 375 mm TL, which is closer to previous estimates. Analysis of spawning stock biomass per recruit demonstrated that biological reference points (e.g., F  SPR) could be affected considerably by shifting maturity schedules, and the effects could be magnified at larger sizes at entry and higher harvest rates. Given the life history strategy of southern flounder and the lack of a developed offshore fishery or sampling program, which combine to prevent access to fish on the spawning grounds, it is probably most judicious to routinely analyze reproductive tissue samples histologically to ensure accurate information on the timing of maturity.

Received April 6, 2012; accepted July 28, 2012
Chemical and Electrical Approaches to Sedation of Cobia: Induction, Recovery, and Physiological Responses to Sedation
Authors: Trushenski Jesse T. , Bowzer John C. , Bowker James D. , Schwarz Michael H.
Published: December 2012

To support the growing interest in marine fisheries research in areas such as biotelemetry, tagging, and tracking, we assessed the ability of various sedatives to facilitate this research in juvenile cobias Rachycentron canadum (∼300 g), namely, tricaine methanesulfonate (MS-222; 150 mg/L), carbon dioxide (CO2; ∼750 mg/L), eugenol (60 mg/L), benzocaine (150 mg/L), and pulsed-DC electrosedation (100 V, 30 Hz, 25% duty cycle, 5-s exposure). Induction times (CO2 [z] > benzocaine [y] > eugenol [y] > MS-222 [y] > electrosedation [x]), recovery of equilibrium (CO2 [z] > eugenol [z] > MS-222 [y] > benzocaine [y] > electrosedation [x]), and responsiveness to tactile stimulus (eugenol [z] > MS-222 [y] > benzocaine [y] > CO2 [xy] > electrosedation [x]) differed significantly among the sedative treatments (treatments with the same letters are not significantly different). Total handling time from initial sedative exposure to recovery differed among the sedatives as well (CO2 [z] > eugenol [y] > benzocaine [x] > MS-222 [x] > electrosedation [w]), with cumulative means ± SEs of 5.9 ± 0.2 min for CO2, 4.1 ± 0.2 for eugenol, 2.7 ± 0.2 min for benzocaine and MS-222, and 1.0 ± 0.2 min for electrosedation. Physiological responses differed significantly over time, with transient increases in plasma cortisol, glucose, osmolality, and lactate that were resolved within 6 h. The overall magnitude of the physiological responses differed among sedatives, depending on the response variable; however, in each case, CO2 elicited the greatest response. Although variations in induction and recovery times were observed, it is likely that these differences can be reasonably accommodated within the context of typical research by adjusting the sedative treatments or allowing for longer induction and recovery times as needed.

Received November 18, 2011; accepted August 17, 2012
Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4
Authors: Junker Yvonne , Zeissig Sebastian , Kim Seong-Jun , Barisani Donatella , Wieser Herbert , Leffler Daniel A. , Zevallos Victor , Libermann Towia A. , Dillon Simon , Freitag Tobias L. , Kelly Ciaran P. , Schuppan Detlef
Published: December 2012

Ingestion of wheat, barley, or rye triggers small intestinal inflammation in patients with celiac disease. Specifically, the storage proteins of these cereals (gluten) elicit an adaptive Th1-mediated immune response in individuals carrying HLA-DQ2 or HLA-DQ8 as major genetic predisposition. This well-defined role of adaptive immunity contrasts with an ill-defined component of innate immunity in celiac disease. We identify the α-amylase/trypsin inhibitors (ATIs) CM3 and 0.19, pest resistance molecules in wheat, as strong activators of innate immune responses in monocytes, macrophages, and dendritic cells. ATIs engage the TLR4–MD2–CD14 complex and lead to up-regulation of maturation markers and elicit release of proinflammatory cytokines in cells from celiac and nonceliac patients and in celiac patients’ biopsies. Mice deficient in TLR4 or TLR4 signaling are protected from intestinal and systemic immune responses upon oral challenge with ATIs. These findings define cereal ATIs as novel contributors to celiac disease. Moreover, ATIs may fuel inflammation and immune reactions in other intestinal and nonintestinal immune disorders.
Sustained effector function of IL-12/15/18–preactivated NK cells against established tumors
Authors: Ni Jing , Miller Matthias , Stojanovic Ana , Garbi Natalio , Cerwenka Adelheid
Published: December 2012

Natural killer cell (NK cell)–based immunotherapy of cancer is hampered by the transient effector function of NK cells. Recently, mouse IL-12/15/18–preactivated NK cells were shown to persist with sustained effector function in vivo. Our study investigated the antitumor activity of such NK cells. A single injection of syngeneic IL-12/15/18–preactivated NK cells, but neither naive nor IL-15– or IL-2–pretreated NK cells, combined with irradiation substantially reduced growth of established mouse tumors. Radiation therapy (RT) was essential for the antitumor activity of transferred NK cells. IL-12/15/18–preactivated NK cells expressed high levels of IL-2Rα (CD25), and their rapid in vivo proliferation depended on IL-2 produced by CD4+ T cells. IL-12/15/18–preactivated NK cells accumulated in the tumor tissue and persisted at high cell numbers with potent effector function that required the presence of CD4+ T cells. RT greatly increased numbers and function of transferred NK cells. Human IL-12/15/18–preactivated NK cells also displayed sustained effector function in vitro. Our study provides a better understanding for the rational design of immunotherapies of cancer that incorporate NK cells. Moreover, our results reveal an essential role of CD4+ T cell help for sustained antitumor activity by NK cells linking adaptive and innate immunity.
Parafermionic edge zero modes in Zn-invariant spin chains
Authors: Fendley Paul
Published: November 2012

A sign of topological order in a gapped one-dimensional quantum chain is the existence of edge zero modes. These occur in the Z
2-invariant Ising/Majorana chain, where they can be understood using free-fermion techniques. Here I discuss their presence in spin chains with Z

n
symmetry, and prove that for appropriate couplings they are exact, even in this strongly interacting system. These modes are naturally expressed in terms of parafermions, generalizations of fermions to the Z

n
case. I show that parafermionic edge zero modes do not occur in the usual ferromagnetic and antiferromagnetic cases, but rather only when the interactions are chiral, so that spatial-parity and time-reversal symmetries are broken.
Strong Resistance AgainstRice grassy stunt virusIs Induced in Transgenic Rice Plants Expressing Double-Stranded RNA of the Viral Genes for Nucleocapsid or Movement Proteins as Targets for RNA Interference
Authors: Shimizu Takumi , Ogamino Takumi , Hiraguri Akihiro , Nakazono-Nagaoka Eiko , Uehara-Ichiki Tamaki , Nakajima Masami , Akutsu Katsumi , Omura Toshihiro , Sasaya Takahide
Published: November 2012

Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, causes significant economic losses in rice production in South, Southeast, and East Asian countries. Growing resistant varieties is the most efficient method to control RGSV; however, suitable resistance genes have not yet been found in natural rice resources. One of the most promising methods to confer resistance against RGSV is the use of RNA interference (RNAi). It is important to target viral genes that play important roles in viral infection and proliferation at an early stage of viral replication. Our recent findings obtained from an RNAi experiment with Rice stripe virus (RSV), a tenuivirus, revealed that the genes for nucleocapsid and movement proteins were appropriate targets for RNAi to confer resistance against RSV. In this study, we transformed rice plants by introducing an RNAi construct of the RGSV genes for the nucelocapsid protein pC5 or movement protein pC6. All progenies from self-fertilized transgenic plants had strong resistance against RGSV infection and did not allow the proliferation of RGSV. Thus, our strategy to target genes for nucleocapsid and movement proteins for conferring viral resistance might be applicable to the plant viruses in the genus Tenuivirus.
SINGLE-AGENT, MINIMAL DOSE, MINIMAL EXPOSURE INTRAARTERIAL CHEMOTHERAPY FOR RETINOBLASTOMA IN A 4-MONTH-OLD INFANT
Authors: Fulco Enzo A. M. , Shields Carol L. , Bianciotto Carlos G. , Jabbour Pascal , Shields Jerry A.
Published: November 2012

Purpose:

To document minimal dose and minimal exposure of chemotherapy for unilateral retinoblastoma.

Methods:

A 4-month-old infant developed leukocoria in the right eye and was found to have unilateral sporadic retinoblastoma.

Results:

The right eye was classified as Group D retinoblastoma, with a single large tumor, moderate subretinal seeding, and total retinal detachment. The retinoblastoma measured 20 mm in basal dimension and 13 mm in ultrasonographic thickness. Options of enucleation, intravenous chemotherapy, and intraarterial chemotherapy were offered, but the latter was chosen because of anticipated, rapid, and more complete response with intraarterial rather than intravenous chemotherapy. After using low dose (3 mg) of single-agent melphalan delivered over 30 minutes into the ostium of the ophthalmic artery of the 4-month-old infant, a complete response with Type 1 regression (complete calcification) of the mass and resolution of all subretinal fluid was found. A second similar dose was delivered to ensure remission of all seeds and tumor with stable findings. Further chemotherapy was stopped. On 6 months of follow-up, the child displayed complete tumor control with 2 cycles of lowest dose (3 mg) intraarterial melphalan. There were no complications.

Conclusion:

In infants younger than 6 months, low dose of only 3-mg single-agent melphalan could be sufficient to control retinoblastoma with minimal exposure.
Hepatic Fibrosis Persists and Progresses Despite Biochemical Improvement in Children Treated With Intravenous Fish Oil Emulsion
Authors: Mercer David F. , Hobson Brandy D. , Fischer Ryan T. , Talmon Geoffrey A. , Perry Deborah A. , Gerhardt Brandi K. , Grant Wendy J. , Botha Jean F. , Langnas Alan N. , Quiros‐Tejeira Ruben E.
Published: November 2012

Objectives:

Intestinal failure–associated liver disease (IFALD) is a multifactorial process, which can culminate in cirrhosis and need for transplantation. Fish oil–based lipid emulsions (FOE) reportedly reverse hyperbilirubinemia, but there are little data on their effect on the histopathology of IFALD.

Methods:

We blindly examined sequential liver biopsy data on 6 children receiving FOE, with scoring of cholestasis, inflammation, fibrosis, and ductal proliferation based on standardized systems. This information was correlated with biochemical and clinical data to determine any possible relations between biologic and histologic improvement.

Results:

The median gestational age was 35 weeks, median birth weight 2064 g, and common most reason for intestinal loss was gastroschisis (5/6 children). Median intestinal length was 26 cm beyond the ligament of Treitz and most children had roughly 2 of 3 of their colonic length. It was observed that although hyperbilirubinemia reversed and hepatic synthetic function was preserved across timepoints, fibrosis was persistent in 2 cases, progressive in 3 cases, and regressed in only 1. It remained severe (grade 2 or higher) in 5 of 6 children at last biopsy. Histologic findings of cholestasis improved in all patients and inflammation improved in 5 of 6 children. There were mixed effects on ductal proliferation and steatosis.

Conclusions:

In children treated with FOE, reversal of hyperbilirubinemia is not reflected by a similar histologic regression of fibrosis at the timepoints studied. Children with IFALD should have active ongoing treatment and be considered for early referral to an Intestinal Failure Program even with a normalized bilirubin.
Opposite differential allocation by males and females of the same species
Authors: Limbourg Tobias , Mateman A. Christa , Lessells C. M.
Published: November 2012

Differential allocation (DA)—the adjustment of an individual's parental investment in relation to its mate's attractiveness—is increasingly recognized as an important component of sexual selection. However, although DA is expected by both sexes of parents in species with biparental care, DA by males has rarely been investigated. We have previously demonstrated a decrease in the feeding rates of female blue tits
Cyanistes caeruleus
when their mate's UV coloration was experimentally reduced (i.e. positive DA). In this study, we used the same experimental protocol in the same population to investigate DA by male blue tits in relation to their female's UV coloration. Males mated to UV-reduced females had
higher
feeding rates than those mated to control females (i.e. negative DA). Thus, male and female blue tits display opposite DA for the same component of parental effort (chick provisioning), the first time that this has been reported for any species.
Underwater acrobatics by the world's largest predator: 360° rolling manoeuvres by lunge-feeding blue whales
Authors: Goldbogen Jeremy A. , Calambokidis John , Friedlaender Ari S. , Francis John , DeRuiter Stacy L. , Stimpert Alison K. , Falcone Erin , Southall Brandon L.
Published: November 2012

The extreme body size of blue whales requires a high energy intake and therefore demands efficient foraging strategies. As an obligate lunge feeder on aggregations of small zooplankton, blue whales engulf a large volume of prey-laden water in a single, rapid gulp. The efficiency of this feeding mechanism is strongly dependent on the amount of prey that can be captured during each lunge, yet food resources tend to be patchily distributed in both space and time. Here, we measured the three-dimensional kinematics and foraging behaviour of blue whales feeding on krill, using suction-cup attached multi-sensor tags. Our analyses revealed 360° rolling lunge-feeding manoeuvres that reorient the body and position the lower jaws so that a krill patch can be engulfed with the whale's body inverted. We also recorded these rolling behaviours when whales were in a searching mode in between lunges, suggesting that this behaviour also enables the whale to visually process the prey field and maximize foraging efficiency by surveying for the densest prey aggregations. These results reveal the complex manoeuvrability that is required for large rorqual whales to exploit prey patches and highlight the need to fully understand the three-dimensional interactions between predator and prey in the natural environment.
How the online social networks are used: dialogues-based structure ofMySpace
Authors: Šuvakov Milovan , Mitrović Marija , Gligorijević Vladimir , Tadić Bosiljka
Published: November 2012

Quantitative study of collective dynamics in online social networks is a new challenge based on the abundance of empirical data. Conclusions, however, may depend on factors such as user's psychology profiles and their reasons to use the online contacts. In this study, we have compiled and analysed two datasets fromMySpace. The data contain networked dialogues occurring within a specified time depth, high temporal resolution and texts of messages, in which the emotion valence is assessed by using the SentiStrength classifier. Performing a comprehensive analysis, we obtain three groups of results: dynamic topology of the dialogues-based networks have a characteristic structure with Zipf's distribution of communities, low link reciprocity and disassortative correlations. Overlaps supporting ‘weak-ties’ hypothesis are found to follow the laws recently conjectured for online games. Long-range temporal correlations and persistent fluctuations occur in the time series of messages carrying positive (negative) emotion; patterns of user communications have dominant positive emotion (attractiveness) and strong impact of circadian cycles and interactivity times longer than 1 day. Taken together, these results give a new insight into the functioning of online social networks and unveil the importance of the amount of information and emotion that is communicated along the social links. All data used in this study are fully anonymized.
Phenotypic plasticity in evolutionary rescue experiments
Authors: Chevin Luis-Miguel , Gallet Romain , Gomulkiewicz Richard , Holt Robert D. , Fellous Simon
Published: December 2012

Population persistence in a new and stressful environment can be influenced by the plastic phenotypic responses of individuals to this environment, and by the genetic evolution of plasticity itself. This process has recently been investigated theoretically, but testing the quantitative predictions in the wild is challenging because (i) there are usually not enough population replicates to deal with the stochasticity of the evolutionary process, (ii) environmental conditions are not controlled, and (iii) measuring selection and the inheritance of traits affecting fitness is difficult in natural populations. As an alternative, predictions from theory can be tested in the laboratory with controlled experiments. To illustrate the feasibility of this approach, we briefly review the literature on the experimental evolution of plasticity, and on evolutionary rescue in the laboratory, paying particular attention to differences and similarities between microbes and multicellular eukaryotes. We then highlight a set of questions that could be addressed using this framework, which would enable testing the robustness of theoretical predictions, and provide new insights into areas that have received little theoretical attention to date.
Spatial congregation of STAT binding directs selective nuclear architecture during T-cell functional differentiation
Authors: Hakim Ofir , Sung Myong-Hee , Nakayamada Shingo , Voss Ty C. , Baek Songjoon , Hager Gordon L.
Published: December 2012

Higher-order genome organization shows tissue-specific patterns. However, functional relevance and the mechanisms shaping the genome architecture are poorly understood. Here we report a profound shift from promiscuous to highly selective genome organization that accompanies the effector lineage choice of differentiating T cells. As multipotent naive cells receive antigenic signals and commit to a T helper (Th) pathway, the genome-wide contacts of a lineage-specific cytokine locus are preferentially enriched for functionally relevant genes. Despite the establishment of divergent interactomes and global reprogramming of transcription in Th1 versus Th2, the overall expression status of the contact genes is surprisingly similar between the two lineages. Importantly, during differentiation, the genomic contacts are retained and strengthened precisely at DNA binding sites of the specific lineage-determining STAT transcription factor. In cells from the specific STAT knock-out mouse, the signature cytokine locus is unable to shed the promiscuous contacts established in the naive T cells, indicating the importance of genomic STAT binding. Altogether, the global aggregation of STAT binding loci from genic and nongenic regions highlights a new role for differentiation-promoting transcription factors in direct specification of higher-order nuclear architecture through interacting with regulatory regions. Such subnuclear environments have significant implications for efficient functioning of the mature effector lymphocytes.
A chromatin link to caste identity in the carpenter ant Camponotus floridanus
Authors: Simola Daniel F. , Ye Chaoyang , Mutti Navdeep S. , Dolezal Kelly , Bonasio Roberto , Liebig Jürgen , Reinberg Danny , Berger Shelley L.
Published: December 2012

In many ant species, sibling larvae follow alternative ontogenetic trajectories that generate striking variation in morphology and behavior among adults. These organism-level outcomes are often determined by environmental rather than genetic factors. Therefore, epigenetic mechanisms may mediate the expression of adult polyphenisms. We produced the first genome-wide maps of chromatin structure in a eusocial insect and found that gene-proximal changes in histone modifications, notably H3K27 acetylation, discriminate two female worker and male castes in Camponotus floridanus ants and partially explain differential gene expression between castes. Genes showing coordinated changes in H3K27ac and RNA implicate muscle development, neuronal regulation, and sensory responses in modulating caste identity. Binding sites of the acetyltransferase CBP harbor the greatest caste variation in H3K27ac, are enriched with motifs for conserved transcription factors, and show evolutionary expansion near developmental and neuronal genes. These results suggest that environmental effects on caste identity may be mediated by differential recruitment of CBP to chromatin. We propose that epigenetic mechanisms that modify chromatin structure may help orchestrate the generation and maintenance of polyphenic caste morphology and social behavior in ants.
Non‐random extinctions dominate plant community changes in abandoned coppices
Authors: Kopecký Martin , Hédl Radim , Szabó Péter
Published: December 2012

The plant community structure of European lowland forests has changed dramatically in the twentieth century, leading to biodiversity decline at various spatial scales. However, due to methodological difficulties associated with simultaneous changes in species diversity and composition, ecological processes behind the changes are still poorly understood.

We analysed temporal changes in forest plant community after the mid‐twentieth‐century abandonment of coppicing in a typical Central European forest, which had been managed as coppice for centuries. We used 122 semi‐permanent plots first surveyed in the 1950s shortly after the last coppicing and again in the 2000s after half a century of natural succession. We used a novel temporal nestedness analysis to disentangle the immigration and extinction processes underlying temporal changes in community structure and tested whether species gains and losses were ecologically random.

The studied vegetation has shifted from the species‐rich assemblages of a relatively open and low‐nutrient forest towards the impoverished flora of a closed‐canopy forest dominated by a few shade‐adapted species. The significant reduction in beta diversity, that is, compositional heterogeneity among plots, indicated taxonomic homogenization of the forest understorey. Temporal species turnover was only a minor component of the community change, and recent assemblages are nested subsets of the former ones. Ecologically non‐random extinctions dominated these changes. Light‐demanding species with a persistent seed bank were the most prone to extinction, while species with high specific leaf area substantially increased in frequency.

Synthesis and applications. The dominant process after the abandonment of coppicing was the ecologically non‐random extinction of light‐demanding species, leading to an impoverished, temporally nested plant community structure. This development is typical for many abandoned coppices and poses a significant threat to forest biodiversity in Europe. If forestry and conservation policies continue to prefer closed‐canopy stands, many endangered species are likely to pay their extinction debts. To restore declining or even locally extinct species, canopy opening in abandoned coppices is urgently needed.
Phenology of Dryopteris affinis ssp. affinis and Polystichum aculeatum: modeling relationships to the climatic variables in a Mediterranean area
Authors: Landi Marco , Zoccola Antonio , Bacaro Giovanni , Angiolini Claudia
Published: December 2012

The phenology of leaves and stages from immature sori to spore release were studied in natural populations of two perennial herbaceous ferns, Dryopteris affinis ssp. affinis and Polystichum aculeatum, for 2 years in Italy. The Generalized Additive Model for Location, Scale and Shape (GAMLSS) was used to predict a particular phenological event from the climatic variables. Both fern species are evergreen with leaf lifespan of 13–14 months in D. affinis ssp. affinis and 15–24 months in P. aculeatum. Their leaf production is seasonal with most flushed in spring. In D. affinis ssp. affinis the decaying of old leaves is sudden whereas in P. aculeatum it is gradual, and in both types the decaying is accelerated just as the new leaves emerge. Temperature is the best predictor for the development of sori and spore release. The end of spore release and leaf emergence are positively affected by temperature and negatively affected by rainfall and snow cover for P. aculeatum. An almost similar response to climatic factors of emergent and senescent leaves and their phenology supportsthe hypothesis that old leaves serve as nutrient storage organs for new leaf growth. Comparison the phenological patterns between the 2 years indicated that the time lapses between each phenological event were the same within seasons for D. affinis ssp. affinis but show some differences for P. aculeatum. We also hypothesize that endogenous factors may play an important role in the phenology of P. aculeatum.
Obstetric factors and different causes of special educational need: retrospective cohort study of 407 503 schoolchildren
Authors: Mackay DF , Smith GCS , Dobbie R , Cooper S‐A , Pell JP
Published: November 2012

Objective

To determine whether relationships with gestational age and birthweight centile vary between specific causes of special educational need (SEN).

Design

Retrospective cohort study.

Setting

Scotland.

Population

A cohort of 407 503 schoolchildren.

Methods

Polytomous logistic regression was used to examine the risk of each cause of SEN across the spectrum of gestation at delivery and birthweight centile, adjusting for potential confounding factors.

Main outcome measures

Crude and adjusted odds ratios and confidence intervals.

Results

Of the 19 821 children with SEN, 557 (2.8%) had sensory impairments, 812 (4.1%) had physical or motor disabilities, 876 (4.4%) had language impairments, 2823 (14.2%) had social, emotional, or behavioural problems, 7018 (35.4%) had intellectual disabilities, 4404 (22.2%) had specific learning difficulties, and 1684 (8.5%) autistic spectrum disorder (ASD). Extreme preterm delivery (at 24–27 weeks of gestation) was a strong predictor of sensory (adjusted OR 23.64, 95% CI 12.03–46.45), physical or motor (adjusted OR 29.69, 95% CI 17.49–50.40), and intellectual (adjusted OR 11.67, 95% CI 8.46–16.10) impairments, with dose relationships across the range of gestation. Similarly, birthweight below the third centile was associated with sensory (adjusted OR 2.85, 95% CI 2.04–3.99), physical or motor (adjusted OR 2.47, 95% CI 1.82–3.37), and intellectual (adjusted OR 2.67, 95% CI 2.41–2.96) impairments. Together, gestation and birthweight centile accounted for 24.0% of SEN arising from sensory impairment, 34.3% arising from physical or motor disabilities, and 26.6% arising from intellectual disabilities. Obstetric factors were less strongly associated with specific learning difficulties and social or emotional problems, and there were no significant associations with ASD.

Conclusions

The association between gestation and birthweight centile and overall risk of SEN is largely driven by very strong associations with sensory, physical or motor impairments, and intellectual impairments.
Mechanisms for flowering plants to benefit arthropod natural enemies of insect pests: Prospects for enhanced use in agriculture
Authors: Lu Zhong‐Xian , Zhu Ping‐Yang , Gurr Geoff M. , Zheng Xu‐Song , Read Donna M. Y. , Heong Kong‐Luen , Yang Ya‐Jun , Xu Hong‐Xing
Published: December 2012

Reduction of noncrop habitats, intensive use of pesticides and high levels of disturbance associated with intensive crop production simplify the farming landscape and bring about a sharp decline of biodiversity. This, in turn, weakens the biological control ecosystem service provided by arthropod natural enemies. Strategic use of flowering plants to enhance plant biodiversity in a well‐targeted manner can provide natural enemies with food sources and shelter to improve biological control and reduce dependence on chemical pesticides. This article reviews the nutritional value of various types of plant‐derived food for natural enemies, possible adverse effects on pest management, and the practical application of flowering plants in orchards, vegetables and field crops, agricultural systems where most research has taken place. Prospects for more effective use of flowering plants to maximize biological control of insect pests in agroecosystem are good but depend up on selection of optimal plant species based on information on the ecological mechanisms by which natural enemies are selectively favored over pest species.
Video‐assisted thoracic surgery lobectomy for unexpected pathologic N2 non‐small cell lung cancer
Authors: Zhou Wenyong , Chen Xiaofeng , Zhang Huijun , Zhang Hui , Zhao Mingchuan
Published: December 2012

Background

This study was performed to assess early and late outcomes of pathologic N2 disease unexpectedly detected in patients with non‐small cell lung cancer undergoing video‐assisted thoracic surgery (VATS) lobectomy for clinical stage I.

Methods

We retrospectively reviewed the clinical features of patients with unexpected N2 non‐small cell lung cancer and their early and late outcomes in the VATS lobectomy group versus the open thoracotomy lobectomy group.

Results

The overall survival time for all 358 patients was 33.26 ± 0.90 months. The overall survival time for 117 cases in the VATS lobectomy group was 36.02 ± 1.44 months. The overall survival time for 241 cases in the open thoracotomy lobectomy group was 31.92 ± 1.14 months. The survival rates for patients in the VATS lobectomy group were 92.31%, 36.75%, 5.13% at one, three, and five years, respectively. The survival rates for patients in the open thoracotomy lobectomy group were 92.12%, 21.58%, 2.49% at one, three, and five years, respectively. A significant difference was found between the two groups regarding this factor (, P = 0.049).

Conclusions

VATS lobectomy is feasible and safe to perform on patients with minimal N2 non‐small cell lung cancer. Even if lymph node metastasis is unexpectedly detected during surgery, with rigorous preoperative evaluation and systematic lymph node dissection, there is no need to convert to open thoracotomy lobectomy.
Fasting blood glucose predicts response to extended‐release metformin in gestational diabetes mellitus
Authors: Corbould Anne , Swinton Fiona , Radford Andrea , Campbell Joanne , McBeath Sue , Dennis Amanda
Published: December 2012

Background

Metformin is increasingly accepted as an alternative to insulin therapy in gestational diabetes mellitus (GDM). The Metformin in Gestational Diabetes (MiG) trial reported similar pregnancy outcomes for metformin versus insulin; however, supplemental insulin was required in 46% of women on metformin.

Aims

We aimed to identify predictors of response to metformin monotherapy in women with GDM attending a general hospital antenatal clinic.

Methods

We offered extended‐release metformin to women diagnosed with GDM (ADIPS 1998 criteria) at ≥24 weeks of gestation. If glucose targets were not achieved (≤5.0 mmol/L fasting, ≤6.7 mmol/L two‐h post‐meal), women were changed to insulin. We carried out an audit to determine characteristics of metformin responders versus nonresponders.

Results

Twenty‐five women chose initial metformin therapy; 16 (64%) achieved satisfactory glycaemic control (responders). Nine women (36%) were changed to insulin: seven due to inadequate control (nonresponders) and two had metformin intolerance. Fasting glucose at oral glucose tolerance test (OGTT) was significantly lower in metformin responders versus nonresponders; two‐h glucose and BMI did not differ. Ninety‐three percent of women with fasting glucose ≤5.2 mmol/L responded to metformin: conversely, at fasting glucose >5.2 mmol/L, 33% responded (P = 0.005). Neonatal outcomes were similar in metformin responders and nonresponders, women who chose initial insulin therapy (n = 25), or were diet‐controlled (n = 21).

Conclusions

In women with GDM, fasting glucose on OGTT predicted response to metformin: at fasting glucose ≤5.2 mmol/L, the probability of response was 93%. Antenatal clinics should determine locally relevant predictors of response to metformin in women with GDM.