bluuebunny/crossref_metadata_2025 huggingface dataset:
Accurate one-dimensional potential energy curve of the linear (H2)2 cluster
Authors: Tung Wei-Cheng , Pavanello Michele , Adamowicz Ludwik
Published: September 2010

We present a sub-0.3 K accuracy, ground-state one-dimensional potential energy curve of the metastable linear configuration of the (H2)2 cluster calculated exclusively with explicitly correlated Gaussian functions with shifted centers. The H2 internuclear distance is kept at the isolated H2 vibrational ground-state average value of 1.448 736 bohr and the intermonomer separation is varied between 2 and 100 bohrs. The analytical gradient of the energy with respect to the nonlinear parameters of the Gaussians (i.e., the exponents and the coordinates of the shifts) has been employed in the variational optimization of the wave function. Procedures for enlarging the basis set and for adjusting the centers of the Gaussians to the varying intermonomer separation have been developed and used in the calculations.
A nearly instantaneous gain response in quantum dash based optical amplifiers
Authors: Capua A. , Eisenstein G. , Reithmaier J. P.
Published: September 2010

We describe a unique phenomenon occurring in InAs/InP quantum dash amplifiers: a nearly instantaneous gain response taking place across the entire inhomogeneously broadened gain spectrum. The phenomenon is induced by a 100–150 fs pulse and is observable using multiwavelength pump probe measurements. Large bias levels and an intense pump pulse are imperative for enacting the ultrafast mechanism which is due to a combination of the gain inhomogeneity, nonlinear two photon absorption and the quantum wirelike density of state function.
Phase transition study of integrated circuit chip power supplying based on ferroelectric ceramic
Authors: Zhang Zhenhai , Cui Zhanzhong , Yan Jinglong , Li Kejie
Published: September 2010

We introduce the tin-modified and niobium-modified lead zirconate titanate ferroelectric ceramics as a micropower supplying source for integrated circuit chip. The ferroelectric ceramic phase transition under transverse shock wave compression can release the depolarization energy to the external storage capacitor. The porous microstructure ferroelectric ceramic micropower-generator is capable of generating low output voltage pulses with amplitudes 50.3 V and with transferred energy 1.12 mJ, and supplying integrated circuit chip with micropower sources. Theoretical calculations are conducted based on circuit analysis law, principle of dynamic high pressure, and shock wave physics, and the calculated response matches well with experimental data.
Size dependent carrier recombination in ZnO nanocrystals
Authors: Pozina G. , Yang L. L. , Zhao Q. X. , Hultman L. , Lagoudakis P. G.
Published: September 2010

Experimental and theoretical studies of fluorescence decay were performed for colloidal ZnO nanocrystals. The fluorescence lifetime reduces from 22 ps to ∼6 ps with decreasing nanocrystal radius. We postulate that non-radiative surface states dominate the carrier dynamics in small ZnO nanocrystals and perform Monte Carlo simulations incorporating carrier diffusion and carrier recombination to model the experimental fluorescence decay dynamics. The percentage of excitons undergoing nonradiative decay due to surface trapping is as high as 84% for nanocrystals with 8 nm radius, which explains the ultrafast decay dynamics observed in small ZnO nanostructures even at low temperatures.
The Contingency of the Laws of Nature
Authors: Meillassoux Quentin
Published: September 2010

My starting point is Hume's sceptical doubt as to the necessity of causal connection. This doubt consists in challenging the metaphysician to found rationally the necessity of the causal relation—that is to say, to prove that it is necessary that the same effects should always follow from the same causes. According to Hume, this challenge cannot be met, because the only instances that could possibly rationally found causal necessity are experience and logical necessity. Now, I can certainly affirm on the basis of experience that causality has never failed in the past; but that does not allow me to prove that the same will apply in the future. As for logic, it prescribes only noncontradiction; and there is nothing contradictory in conceiving that objects might behave differently tomorrow than they did today, under exactly the same conditions. Hume's conclusion is that our adhesion to causality proceeds from a vital habit, an accustomedness that persuades us that the causal sequences we have observed in the past will be repeated identically in the future. This conclusion is sceptical in the sense that it disqualifies the metaphysical claim that one can discover through a priori reasoning the necessities that govern nature. However, it is possible to draw a very different conclusion from the same premises. For, rather than conceding that reason cannot prove causal necessity a priori, why not affirm that reason reveals that all causal relations are contingent, that it opens up the possibility that, in the future, completely different effects could follow from exactly the same causes? In that case, reason would have discovered, beneath the apparent fixity of empirical constants, a chaos indifferent to all causality. This is the hypothesis to be examined, and we shall try to show that there exist precise reasons to take it seriously.
Atmospheric Attunements
Authors: Stewart Kathleen
Published: September 2010

This paper proposes an analytic attention to the charged atmospheres of everyday life. It asks how circulating forces are generated as atmospheres per se, how they spawn worlds, animate forms of attachment and detachment, and become the live background of living in and living through things. Writing through several small cases selected out of countless potentially describable moments and scenes in which the sense of something happening becomes tactile, I try to open a proliferative list of questions about how forces come to reside in experiences, conditions, things, dreams, landscapes, imaginaries, and lived sensory moments. How do people dwelling in them become attuned to the sense of something coming into existence or something waning, sagging, dissipating, enduring, or resonating with what is lost or promising? I suggest that atmospheric attunements are palpable and sensory yet imaginary and uncontained, material yet abstract. They have rhythms, valences, moods, sensations, tempos, and lifespans. They can pull the senses into alert or incite distraction or denial.
A qualitative study of the management and biosecurity practices of 13 interviewed pig owners selling via informal means in New South Wales, Australia
Authors: Schembri N. , Holyoake P. K. , Hernández-Jover M. , Toribio J.-A. L. M. L.
Published: September 2010

There is increasing interest in the trading practices of producers who market pigs at live auction in Australia and the potential for infectious disease establishment and spread. The practices that underpin the commercial pork industry in Australia are well known. However, little is known about informal movements of pigs in Australia, and the biosecurity risks associated with pig production enterprises that utilise these methods of trade. The aim of this study was to qualitatively evaluate the biosecurity and pig-keeping practices of owners who trade pigs informally for Foot and Mouth Disease and Classical Swine Fever exposure and spread. Interviews were conducted with 13 pig owners who trade via informal means between April and June 2009. Information provided by producers was able to be validated for the six interviews conducted on-farm. There was limited application of recommended biosecurity practices on-farm and few kept health and management records. All interviewees reared other livestock species, such as ruminants and/or poultry, as well as pigs. Most interviewed owners claimed to quarantine introduced pigs from the main herd; however, few complied with industry recommendations. The results of this study suggest that pig owners (n = 13 interviewed) who currently trade their pigs informally pose few threats for the introduction of emergency animal disease. Pig keepers largely obtained their pig feed from reputable sources and appeared to have a sound understanding of swill feeding. However, the lack of on-farm biosecurity, variable quarantine practices and the failure to keep health records could play a role in the spread of an emergency animal disease if it was to be introduced. Further work is being undertaken to determine, qualitatively, the risk associated with the management practices undertaken by informal pig traders and Foot and Mouth Disease and Classical Swine Fever introduction and spread.
Effects of porcine reproductive and respiratory syndrome virus infection on the performance of pregnant gilts and growing pigs
Authors: Lewis Craig R. G. , Ait-Ali Tahar , Wilson Alison , Westcott Dave G. , Frossard Jean-Pierre , Naidu Brindha , Mellencamp Marnie A. , Torremorell Montserrat , Drew Trevor , Bishop Stephen C. , Archibald Alan L.
Published: September 2010

This study examined the effects of porcine reproductive and respiratory syndrome virus (PRRSV) infection on (1) pregnant and (2) growing Landrace and crossbred (Large White × Pietrain) pigs. First, recently pregnant gilts were spilt into a control and a challenged group, which was inoculated with the PRRSV, and phenotypic effects were recorded. In the Landrace breed, infected gilts had a significantly reduced number of fetuses (8.9 versus 11.8), but there were insufficient data to make the same comparison in crossbred gilts. The Landrace had a smaller suppression of weight gain during pregnancy than the crossbred line [56% (0.66 to 0.29 kg/day) versus 85% (0.45 to 0.07 kg/day) reduction], suggesting greater tolerance of the PRRSV infection. Second, impacts on growing pigs were examined with the same deliberate challenge methodology. Some pigs appeared not to become infected from the initial inoculation, but were possibly subsequently infected by cohorts. However, there were indications of Landrace line resistance in terms of an increased time to seroconvert, with weight gain patterns also suggesting Landrace tolerance. In summary, this study demonstrated that breeds differ consistently in phenotypic impacts of PRRSV infection.
Hierarchical Assembly Involving Hydroxyethyl-substituted Imidazolium Cations and p-Sulfonatocalix[4]arenes
Authors: Ling Irene , Alias Yatimah , Skelton Brian W. , Raston Colin L.
Published: September 2010

A multiple-component bilayer involving four different ions has preferential binding of functionalized 3-(2-hydroxyethyl)-1-methylimidazolium in the cavity of bowl-shaped p-sulfonatocalix[4]arene, with the supermolecule being capped by a water molecule involving an O–H···π(imidazolium) interaction, an O···HO H-bond involving the hydroxyethyl group, and an SO···HO H-bond. The nature of the interplay of the components has been mapped out using Hirshfeld surface analysis. The [imidazolium ∩ calixarene] supermolecule persists in solution.
Incidence of chromosomal abnormalities in bovine blastocysts derived from unsorted and sex-sorted spermatozoa
Authors: Garcia-Herreros M. , Carter T. F. , Villagómez D. A. F. , MacAulay A. D. , Rath D. , King W. A. , Lonergan P.
Published: September 2010

The aim of the present study was to examine the incidence of chromosomal abnormalities in bovine blastocysts produced by IVF with unsorted, X-sorted or Y-sorted spermatozoa. In Experiment 1, individual blastocysts were processed to examine the incidence of mixoploidy using fluorescent in situ hybridisation. Overall, 80% (44/55) of blastocysts were mixoploid (10/15, 14/15 and 20/25 for X-sorted, Y-sorted and unsorted spermatozoa, respectively; P > 0.05). However, the prevalence of abnormal XY chromosome complements was relatively low in all groups; on average, only a small fraction of the total nuclei per embryo appeared polyploid (1.64%, 5.62% and 6.0% for X-sorted, Y-sorted and unsorted spermatozoa, respectively). Interestingly, 20% (5/25) of blastocysts derived from unsorted spermatozoa were found to be chimeric (XX/XY). In Experiment 2, chimeric embryos were detected among the blastocysts derived from two of five sires tested. In addition, one chimeric blastocyst was detected among nine in vivo-derived blastocysts obtained following AI. In conclusion, based on the results of the present study, the incidence of chromosomal abnormalities did not different between blastocysts derived from sex-sorted or unsorted spermatozoa. In addition, the occurrence of mixed sex chimeras was not limited to a single sire and was not unique to blastocysts derived from IVF.
Structural and magnetic properties of (Al, Fe)-codoped SiC
Authors: Song B , Chen X L , Han J C , Jian J K , Bao H Q , Li H , Zhu K X , Wang W Y , Wang G , Zuo H B , Zhang X H , Meng S H
Published: September 2010

In this study, as a first attempt, we choose Al and transition metals (TMs), Fe, as codoping atoms to synthesize (Al, TM)-codoped SiC. X-ray diffraction and Raman analysis showed that a series of single-phase codoped 4H-SiC samples were obtained and no trace of any other impurity phases, such as Fe3Si and polytypes of other types of SiC, was found. Measurement of magnetic properties showed that codoping by Al and Fe elements changed the original glassy ferromagnetism (FM) features in Al-doped SiC and induced a robust room temperature FM order that gradually dominated (Al, Fe)-codoped 4H-SiC with increase in Fe content. The contribution of Al elements to the magnetic properties of (Al, Fe)-codoped 4H-SiC can be neglected and the magnetic origin should be ascribed to be induced by Fe doping. The only major role of Al is to stabilize the codoped crystal structure as 4H- single phase. As the first investigation on (Al, TM)-codoped SiC, this study opens a new pathway to obtain TM-doped SiC-based diluted magnetic semiconductors with a high T
c via the codoping strategy.
The critical bias for the Hamiltonicity game is (1+𝑜(1))𝑛/ln𝑛
Authors: Krivelevich Michael
Published: September 2010

We prove that in the biased

(
1
:
b
)

(1:b)

Hamiltonicity Maker-Breaker game, played on the edges of the complete graph

K
n

K_n

, Maker has a winning strategy for

b
(
n
)
≤

(
1
−

30

ln

1

/

4

⁡
n

)

n

ln
⁡
n

b(n)\le \left (1-\frac {30}{\ln ^{1/4}n}\right )\frac {n}{\ln n}

, for all large enough

n
n

.
Sheaves on affine Schubert varieties, modular representations, and Lusztig’s conjecture
Authors: Fiebig Peter
Published: September 2010

We relate a certain category of sheaves of

k
k

-vector spaces on a complex affine Schubert variety to modules over the

k
k

-Lie algebra (for

char
⁡
k
>
0

\operatorname {char} k>0

) or to modules over the small quantum group (for

char
⁡
k
=
0

\operatorname {char} k=0

) associated to the Langlands dual root datum. As an application we give a new proof of Lusztig’s conjecture on quantum characters and on modular characters for almost all characteristics. Moreover, we relate the geometric and representation-theoretic sides to sheaves on the underlying moment graph, which allows us to extend the known instances of Lusztig’s modular conjecture in two directions: We give an upper bound on the exceptional characteristics and verify its multiplicity-one case for all relevant primes.
Oxysterol Binding Protein-dependent Activation of Sphingomyelin Synthesis in the Golgi Apparatus Requires Phosphatidylinositol 4-Kinase IIα
Authors: Banerji Sangeeta , Ngo Mike , Lane Ciaran F. , Robinson Carolyn-Ann , Minogue Shane , Ridgway Neale D.
Published: September 2010

Cholesterol and sphingomyelin (SM) associate in raft domains and are metabolically coregulated. One aspect of coordinate regulation occurs in the Golgi apparatus where oxysterol binding protein (OSBP) mediates sterol-dependent activation of ceramide transport protein (CERT) activity and SM synthesis. Because CERT transfer activity is dependent on its phosphatidylinositol 4 phosphate [PtdIns(4)P]-specific pleckstrin homology domain, we investigated whether OSBP activation of CERT involved a Golgi-associated PtdIns 4-kinase (PI4K). Cell fractionation experiments revealed that Golgi/endosome-enriched membranes from 25-hydroxycholesterol-treated Chinese hamster ovary cells had increased activity of a sterol-sensitive PI4K that was blocked by small interfering RNA silencing of OSBP. Consistent with this sterol-requirement, OSBP silencing also reduced the cholesterol content of endosome/trans-Golgi network (TGN) fractions containing PI4KIIα. PI4KIIα, but not PI4KIIIβ, was required for oxysterol-activation of SM synthesis and recruitment of CERT to the Golgi apparatus. However, neither PI4KIIα nor PI4KIIIβ expression was required for 25-hydroxycholesterol–dependent translocation of OSBP to the Golgi apparatus. The presence of OSBP, CERT, and PI4KIIα in the TGN of oxysterol-stimulated cells suggests that OSBP couples sterol binding or transfer activity with regulation of PI4KIIα activity, leading to CERT recruitment to the TGN and increased SM synthesis.
The New Markets for Renewable Identification Numbers
Authors: Thompson Wyatt , Meyer Seth , Westhoff Pat
Published: September 2010

Renewable Identification Numbers (RINs) were developed to act as tracking mechanisms that ensure compliance with the U.S. biofuel use mandates legislated in 2005 and increased and adjusted to include sub‐mandates in 2007. Reviewing the rules for RIN production and use, we conclude that RIN prices will be hierarchical, and rollover provisions allow stock‐holding. We illustrate our interpretation by constructing RIN supply and use tables, and by discussing how expiring tax credits and the specific tariff raise RIN prices and mandate costs. RIN markets are critical for estimating biofuel use mandate effects on biofuel and feedstock markets and welfare.
Spial: analysis of subtype-specific features in multiple sequence alignments of proteins
Authors: Wuster Arthur , Venkatakrishnan A. J. , Schertler Gebhard F. X. , Babu M. Madan
Published: September 2010

Motivation: Spial (Specificity in alignments) is a tool for the comparative analysis of two alignments of evolutionarily related sequences that differ in their function, such as two receptor subtypes. It highlights functionally important residues that are either specific to one of the two alignments or conserved across both alignments. It permits visualization of this information in three complementary ways: by colour-coding alignment positions, by sequence logos and optionally by colour-coding the residues of a protein structure provided by the user. This can aid in the detection of residues that are involved in the subtype-specific interaction with a ligand, other proteins or nucleic acids. Spial may also be used to detect residues that may be post-translationally modified in one of the two sets of sequences.

Availability:  http://www.mrc-lmb.cam.ac.uk/genomes/spial/; supplementary information is available at http://www.mrc-lmb.cam.ac.uk/genomes/spial/help.html

Contact:  ajv@mrc-lmb.cam.ac.uk
Annie Ernaux's ‘Proof of Life’:
L'Usage de la photo
Authors: Kawakami Akane
Published: September 2010

L'Usage de la photo
(2005) is the portrait of a unique year in Annie Ernaux's life when she was having a passionate affair as well as undergoing treatment for breast cancer. This article will explore how
L'Usage de la photo
, which is made up of texts and photographs by Ernaux and her partner Marc Marie, is both a representation and a
proof
: I shall argue that Ernaux insists on a referential link between her text and reality in this work, making it into a ‘proof of life’ created during the period of her illness. Using the figure of metamorphosis to describe the relationship that Ernaux posits between her text and its eventual reception, I show how its structure helps her, almost as much as her partner does, to survive her ordeal. As her condition improves, Ernaux inclines towards disowning both project and partner in her reignited desire for life and normality. The competing drives in the work between chronicling her illness and rejecting it in the first flush of health are ultimately resolved in an image: an untaken, imaginary photograph symbolizing maternity. I argue that this final portrait shows Ernaux giving birth to the book, her lover, and her post-cancerous self.
Sense and Rhythm in La Fontaine's
Fables
Authors: Pensom Roger
Published: September 2010

Maya Slater has drawn attention to the stylistic importance of accent distribution within the phrase for the reading of La Fontaine's
Fables
. Linguistic opinion is currently divided on the nature and function of this accent in verse, the dominant view being that metre in French is nothing but conserved syllable-count and that accent within the hemistich/line is free, that is, non-metrical. The
Fables
present a particular problem for this view, since La Fontaine's free alternation of the canonical alexandrine and decasyllable with lines of seven or eight syllables violates the principle of isosyllabic recurrence fundamental to the isosyllabist thesis. It is, however, possible to ‘save the phenomenon’: evidence is presented here that intraphrasal accent occurs in this verse in rule-governed form, which in turn suggests that it has a ‘metrical’ (‘measuring’) role, compensating for the absence of isosyllabic equivalence. The resulting accent distribution, moreover, serves as a raw material for the creation of La Fontaine's highly personal poetic meaning. A close analysis of three texts shows how La Fontaine's ‘free verse’ organizes the accentual resources of his language to create his characteristic effects, exciting our awareness of the
physical
nature of our response to his poetry.
History, Ideology, and Camus's ‘Le Renégat’
Authors: Margerrison Christine
Published: September 2010

Much discussion of Camus and colonialism relies on the discourse of Algerian nationalism, where history itself was censored in favour of myth. This influence raises ethical issues about the treatment of empirical evidence when faced with nationalist ideology, particularly when this ideology emanates from a state repeatedly accused of torturing its own citizens. The abandonment of this conceptual framework enables investigation of those areas it excludes, such as religion, extreme forms of violence, and a history that did not begin in 1830. Knowledge of Algerian history rather than its ideological counterpart is essential for an assessment of Camus's treatment of history. Through reference to ‘Le Renégat ou un esprit confus’ the aim here is to show that empirical evidence is central to an understanding of this story's possible meanings.
Effects of Temperature, Humidity, and Wounding on Development of Phytophthora Rot of Cucumber Fruit
Authors: Granke L. L. , Hausbeck M. K.
Published: September 2010

The effects of temperature (10, 15, 20, 25, 30, and 35°C) and relative humidity (~35, 60, 70, 80, and 100%) on development of Phytophthora fruit rot, caused by Phytophthora capsici, of pickling cucumber (Cucumis sativus) were investigated in controlled growth chamber studies. The effect of wounding on disease development was characterized for small (2.0 to 2.5 cm diameter × 8 to 9 cm long), medium (3.0 to 4.0 cm diameter × 12.0 to 13.0 cm long), and large (>4.5 cm diameter × >14 cm long) pickling cucumbers. Lesions developed on cucumbers incubated at all temperatures tested except 10 and 35°C. Disease severity was greatest on cucumbers incubated at 25°C at 4 days postinoculation (dpi). Lesions formed on cucumbers incubated at all relative humidities tested. The diameter of water-soaking and pathogen growth increased as the incubation relative humidity increased. Wounding lessened age-related resistance in pickling cucumbers. The diameter of water-soaking was similar for all wounded cucumbers at 4 dpi regardless of fruit size. Sporangial production was greater on small and medium fruits than on large fruits. These results indicate that P. capsici is capable of infecting cucumbers over a wide range of temperature and relative humidity conditions. Wounding increases the susceptibility of pickling cucumbers to P. capsici.
Phytophthora ramorum in Canada: Evidence for Migration Within North America and from Europe
Authors: Goss Erica M. , Larsen Meg , Vercauteren Annelies , Werres Sabine , Heungens Kurt , Grünwald Niklaus J.
Published: September 2010

Phytophthora ramorum, the cause of sudden oak death on oak and ramorum blight on woody ornamentals, has been reported in ornamental nurseries on the West Coast of North America from British Columbia to California. Long-distance migration of P. ramorum has occurred via the nursery trade, and shipments of host plants are known to have crossed the U.S.–Canadian border. We investigated the genotypic diversity of P. ramorum in Canadian nurseries and compared the Canadian population with U.S. and European nursery isolates for evidence of migration among populations. All three of the P. ramorum clonal lineages were found in Canada but, unexpectedly, the most common was the NA2 lineage. The NA1 clonal lineage, which has been the most common lineage in U.S. nurseries, was found relatively infrequently in Canada, and these isolates may have been the result of migration from the United States to Canada. The EU1 lineage was observed almost every year and shared multilocus genotypes with isolates from Europe and the United States. Estimation of migration rates between Europe and North America indicated that migration was higher from Europe to North America than vice versa, and that unidirectional migration from Europe to North America was more likely than bidirectional migration.
Brain Networks Maintain a Scale-free Organization across Consciousness, Anesthesia, and Recovery
Authors: Lee UnCheol , Oh GabJin , Kim Seunghwan , Noh GyuJung , Choi ByungMoon , Mashour George A.
Published: September 2010

Background

Loss of consciousness is an essential feature of general anesthesia. Although alterations of neural networks during anesthesia have been identified in the spatial domain, there has been relatively little study of temporal organization.

Methods

Ten healthy male volunteers were anesthetized with an induction dose of propofol on two separate occasions. The duration of network connections in the brain was analyzed by multichannel electroencephalography and the minimum spanning tree method. Entropy of the connections was calculated based on Shannon entropy. The global temporal configuration of networks was investigated by constructing the cumulative distribution function of connection times in different frequency bands and different states of consciousness.

Results

General anesthesia was associated with a significant reduction in the number of network connections, as well as significant alterations of their duration. These changes were most prominent in the δ bandwidth and were also associated with a significant reduction in entropy of the connection matrix. Despite these and other changes, a global "scale-free" organization was consistently preserved across multiple subjects, anesthetic exposures, states of consciousness, and electroencephalogram frequencies.

Conclusions

Our data suggest a fundamental principle of temporal organization of network connectivity that is maintained during consciousness and anesthesia, despite local changes. These findings are consistent with a process of adaptive reconfiguration during general anesthesia.
Pathophysiology and Treatment of Coagulopathy in Massive Hemorrhage and Hemodilution
Authors: Bolliger Daniel , Görlinger Klaus , Tanaka Kenichi A. , Warner David S.
Published: September 2010

Fluid resuscitation after massive hemorrhage in major surgery and trauma may result in extensive hemodilution and coagulopathy, which is of a multifactorial nature. Although coagulopathy is often perceived as hemorrhagic, extensive hemodilution affects procoagulants as well as anticoagulant, profibrinolytic, and antifibrinolytic elements, leading to a complex coagulation disorder. Reduced thrombin activation is partially compensated by lower inhibitory activities of antithrombin and other protease inhibitors, whereas plasma fibrinogen is rapidly decreased proportional to the extent of hemodilution. Adequate fibrinogen levels are essential in managing dilutional coagulopathy. After extensive hemodilution, fibrin clots are more prone to fibrinolysis because major antifibrinolytic proteins are decreased.Fresh frozen plasma, platelet concentrate, and cryoprecipitate are considered the mainstay hemostatic therapies. Purified factor concentrates of plasma origin and from recombinant synthesis are increasingly used for a rapid restoration of targeted factors. Future clinical studies are necessary to establish the specific indication, dosing, and safety of novel hemostatic interventions.
Breakdown of within- and between-network Resting State Functional Magnetic Resonance Imaging Connectivity during Propofol-induced Loss of Consciousness
Authors: Boveroux Pierre , Vanhaudenhuyse Audrey , Bruno Marie-Aurélie , Noirhomme Quentin , Lauwick Séverine , Luxen André , Degueldre Christian , Plenevaux Alain , Schnakers Caroline , Phillips Christophe , Brichant Jean-François , Bonhomme Vincent , Maquet Pierre , Greicius Michael D. , Laureys Steven , Boly Mélanie
Published: September 2010

Background

Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes during pharmacological modulation of the level of consciousness.

Methods

Low-frequency spontaneous blood oxygen level-dependent fluctuations were measured in 19 healthy volunteers during wakefulness, mild sedation, deep sedation with clinical unconsciousness, and subsequent recovery of consciousness.

Results

Propofol-induced decrease in consciousness linearly correlates with decreased corticocortical and thalamocortical connectivity in frontoparietal networks (i.e., default- and executive-control networks). Furthermore, during propofol-induced unconsciousness, a negative correlation was identified between thalamic and cortical activity in these networks. Finally, negative correlations between default network and lateral frontoparietal cortices activity, present during wakefulness, decreased proportionally to propofol-induced loss of consciousness. In contrast, connectivity was globally preserved in low-level sensory cortices, (i.e., in auditory and visual networks across sedation stages). This was paired with preserved thalamocortical connectivity in these networks. Rather, waning of consciousness was associated with a loss of cross-modal interactions between visual and auditory networks.

Conclusions

Our results shed light on the functional significance of spontaneous brain activity fluctuations observed in functional magnetic resonance imaging. They suggest that propofol-induced unconsciousness could be linked to a breakdown of cerebral temporal architecture that modifies both within- and between-network connectivity and thus prevents communication between low-level sensory and higher-order frontoparietal cortices, thought to be necessary for perception of external stimuli. They emphasize the importance of thalamocortical connectivity in higher-order cognitive brain networks in the genesis of conscious perception.
Hepatic Progenitor Cell Proliferation and Liver Injury in α‐1‐Antitrypsin Deficiency
Authors: Brunt Elizabeth M , Blomenkamp Keith , Ahmed Muneeb , Ali Faiza , Marcus Nancy , Teckman Jeffrey
Published: September 2010

Objectives:

Homozygous ZZ α‐1‐antitrypsin (a1AT) deficiency is a common genetic liver disease that causes liver injury and hepatocellular carcinoma (HCC). The a1AT mutant Z gene encodes a mutant protein that accumulates within hepatocytes leading to hepatocellular death and a hepatic regenerative response. However, the mechanisms linking hepatocellular injury to these responses are poorly understood. In this study, we examined liver injury and response in human liver and in transgenic mice for involvement of hepatic progenitor cells.

Methods:

Liver biopsy specimens of low‐grade, early‐stage human ZZ liver exhibiting minimal inflammation and minimal fibrosis (grade 1 and stage 1) were examined for hepatic progenitor cell (HPC) proliferation using immunoreactivity for cytokeratin‐7 (CK‐7). Transgenic mouse model liver and other selected human biopsies were also examined.

Results:

Increased CK‐7‐positive HPC proliferation was seen in human ZZ liver compared to normal liver, but was 5‐fold less HPC proliferation than in grade‐ and stage‐matched disease control hepatitis C–infected liver. Livers from PiZ mice, a model transgenic for the human a1AT mutant Z gene, which recapitulates the human injury, also showed HPC proliferation. Human ZZ liver and PiZ mice develop dysplasia in the liver and HCC. HCC in PiZ mice was also characterized by HPC proliferation. Progressive hepatic fibrosis with age in the PiZ mice is demonstrated for the first time in the present study.

Conclusions:

Chronic injury in both ZZ human and PiZ mouse liver is associated with hepatic fibrosis and a unique magnitude of HPC proliferation within the hepatic proliferative response.
Fight for your breeding right: hierarchy re-establishment predicts aggression in a social queue
Authors: Wong Marian , Balshine Sigal
Published: September 2010

Social aggression is one of the most conspicuous features of animal societies, yet little is known about the causes of individual variation in aggression within social hierarchies. Recent theory suggests that when individuals form queues for breeding, variation in social aggression by non-breeding group members is related to their probability of inheriting breeding status. However, levels of aggression could also vary as a temporary response to changes in the hierarchy, with individuals becoming more aggressive as they ascend in rank, in order to re-establish dominance relationships. Using the group-living fish,
Neolamprologus pulcher
, we show that subordinates became more aggressive after they ascended in rank. Female ascenders exhibited more rapid increases in aggression than males, and the increased aggression was primarily directed towards group members of adjacent rather than non-adjacent rank, suggesting that social aggression was related to conflict over rank. Elevated aggression by ascenders was not sustained over time, there was no relationship between rank and aggression in stable groups, and aggression given by ascenders was not sex-biased. Together, these results suggest that the need to re-establish dominance relationships following rank ascension is an important determinant of variation in aggression in animal societies.
Predator cues alter the timing of developmental events in gastropod embryos
Authors: Rundle Simon D. , Smirthwaite J. J. , Colbert M. W. , Spicer J. I.
Published: September 2010

Heterochrony, differences in the timing of developmental events between descendent species and their ancestors, is a pervasive evolutionary pattern. However, the origins of such timing changes are still not resolved. Here we show, using sequence analysis, that exposure to predator cues altered the timing of onset of several developmental events in embryos of two closely related gastropod species:
Radix balthica
and
Radix auricularia
. These timing alterations were limited to certain events and were species-specific. Compared with controls, over half (62%) of exposed
R. auricularia
embryos had a later onset of body flexing and an earlier occurrence of the eyes and the heart; in
R. balthica
, 67 per cent of exposed embryos showed a later occurrence of mantle muscle flexing and an earlier attachment to, and crawling on, the egg capsule wall. The resultant developmental sequences in treated embryos converged, and were more similar to one another than were the sequences of the controls for both species. We conclude that biotic agents can elicit altered event timing in developing gastropod embryos. These changes were species-specific, but did not occur in all individuals. Such developmental plasticity in the timing of developmental events could be an important step in generating interspecific heterochrony.
Stroke in atrial fibrillation—hope on the horizon?
Authors: Jamil-Copley Shahnaz , Kanagaratnam Prapa
Published: September 2010

Atrial fibrillation (AF), a chaotic and irregular contraction of the atria, remains the most common cardiac arrhythmia affecting up to 1.5 per cent of the world population. It has significant economic and personal implications primarily owing to the associated fivefold increase in risk of thromboembolic stroke. The mainstay of risk reduction therapy remains warfarin, use of which can be limited owing to a multitude of issues ranging from drug and food interactions to under-treatment reflected in sub-therapeutic blood levels despite adequate compliance. Pursuit of novel drug alternatives have led to the licence of a new contender (Dabigatran) with a more attractive pharmacotherapeutic profile, some 50 years after warfarin was introduced for human use. A recent non-pharmacological alternative is the Watchman device which has received licence for use. Tested in the PROTECT-AF study, the Watchman device was found to be non-inferior to warfarin in the occurrence of stroke, cardiovascular or unexplained death, or systemic emboli for up to 3 years with less intracranial haemorrhages. The events in the watchman group occurred early and were related to the procedure. These peri-procedural complications are likely to diminish with improved operator experience and ongoing development of the technology. For now, patients with AF who would benefit tremendously from but cannot be treated with warfarin owing to contraindication to, or intolerance of, anticoagulation are considered for device implantation. Despite promising new pharmacotherapeutic advances in the prevention of strokes related to AF, it has taken 50 years for alternative non-pharmacological approaches to become available for clinical use.
Chemotaxis can take plant-parasitic nematodes to the source of a chemo-attractant via the shortest possible routes
Authors: Reynolds Andy M. , Dutta Tushar K. , Curtis Rosane H. C. , Powers Stephen J. , Gaur Hari S. , Kerry Brian R.
Published: September 2010

It has long been recognized that chemotaxis is the primary means by which nematodes locate host plants. Nonetheless, chemotaxis has received scant attention. We show that chemotaxis is predicted to take nematodes to a source of a chemo-attractant via the shortest possible routes through the labyrinth of air-filled or water-filled channels within a soil through which the attractant diffuses. There are just two provisos: (i) all of the channels through which the attractant diffuses are accessible to the nematodes and (ii) nematodes can resolve all chemical gradients no matter how small. Previously, this remarkable consequence of chemotaxis had gone unnoticed. The predictions are supported by experimental studies of the movement patterns of the root-knot nematodes
Meloidogyne incognita
and
Meloidogyne graminicola
in modified Y-chamber olfactometers filled with Pluronic gel. By providing two routes to a source of the attractant, one long and one short, our experiments, the first to demonstrate the routes taken by nematodes to plant roots, serve to test our predictions. Our data show that nematodes take the most direct route to their preferred hosts (as predicted) but often take the longest route towards poor hosts. We hypothesize that a complex of repellent and attractant chemicals influences the interaction between nematodes and their hosts.
An application of compound Poisson modelling to biological dosimetry
Authors: Puig Pedro , Barquinero Joan Francesc
Published: September 2010

In this paper, the
r
th-order univariate Hermite distributions are proposed to model the number of dicentrics in biological dosimetry. These families of distributions are introduced from compound Poisson process modelling. Regression models appropriate for analysing the number of dicentrics as a function of doses of radiation are presented, and an example of application is also given.
Genetic differentiation of the house mouse around the Mediterranean basin: matrilineal footprints of early and late colonization
Authors: Bonhomme François , Orth Annie , Cucchi Thomas , Rajabi-Maham Hassan , Catalan Josette , Boursot Pierre , Auffray Jean-Christophe , Britton-Davidian Janice
Published: September 2010

The molecular signatures of the recent expansion of the western house mouse,Mus musculus domesticus, around the Mediterranean basin are investigated through the study of mitochondrial D-loop polymorphism on a 1313 individual dataset. When reducing the complexity of the matrilineal network to a series of haplogroups (HGs), our main results indicate that: (i) several HGs are recognized which seem to have almost simultaneously diverged from each other, confirming a recent expansion for the whole subspecies; (ii) some HGs are geographically delimited while others are widespread, indicative of multiple introductions or secondary exchanges; (iii) mice from the western and the eastern coasts of Africa harbour largely different sets of HGs; and (iv) HGs from the two shores of the Mediterranean are more similar in the west than in the east. This pattern is in keeping with the two-step westward expansion proposed by zooarchaeological data, an early one coincident with the Neolithic progression and limited to the eastern Mediterranean and a later one, particularly evident in the western Mediterranean, related to the generalization of maritime trade during the first millennium BC and onwards. The dispersal of mice along with humans, which continues until today, has for instance left complex footprints on the long ago colonized Cyprus or more simple ones on the much more recently populated Canary Islands.
Archaeal phylogenomics provides evidence in support of a methanogenic origin of the Archaea and a thaumarchaeal origin for the eukaryotes
Authors: Kelly S. , Wickstead B. , Gull K.
Published: September 2010

We have developed a machine-learning approach to identify 3537 discrete orthologue protein sequence groups distributed across all available archaeal genomes. We show that treating these orthologue groups as binary detection/non-detection data is sufficient to capture the majority of archaeal phylogeny. We subsequently use the sequence data from these groups to infer a method and substitution-model-independent phylogeny. By holding this phylogeny constrained and interrogating the intersection of this large dataset with both the Eukarya and the Bacteria using Bayesian and maximum-likelihood approaches, we propose and provide evidence for a methanogenic origin of the Archaea. By the same criteria, we also provide evidence in support of an origin for Eukarya either within or as sisters to the Thaumarchaea.
Sea level, dinosaur diversity and sampling biases: investigating the ‘common cause’ hypothesis in the terrestrial realm
Authors: Butler Richard J. , Benson Roger B. J. , Carrano Matthew T. , Mannion Philip D. , Upchurch Paul
Published: September 2010

The fossil record is our primary window onto the diversification of ancient life, but there are widespread concerns that sampling biases may distort observed palaeodiversity counts. Such concerns have been reinforced by numerous studies that found correlations between measures of sampling intensity and observed diversity. However, correlation does not necessarily mean that sampling controls observed diversity: an alternative view is that both sampling and diversity may be driven by some common factor (e.g. variation in continental flooding driven by sea level). The latter is known as the ‘common cause’ hypothesis. Here, we present quantitative analyses of the relationships between dinosaur diversity, sampling of the dinosaur fossil record, and changes in continental flooding and sea level, providing new insights into terrestrial common cause. Although raw data show significant correlations between continental flooding/sea level and both observed diversity and sampling, these correlations do not survive detrending or removal of short-term autocorrelation. By contrast, the strong correlation between diversity and sampling is robust to various data transformations. Correlations between continental flooding/sea level and taxic diversity/sampling result from a shared upward trend in all data series, and short-term changes in continental flooding/sea level and diversity/sampling do not correlate. The hypothesis that global dinosaur diversity is tied to sea-level fluctuations is poorly supported, and terrestrial common cause is unsubstantiated as currently conceived. Instead, we consider variation in sampling to be the preferred null hypothesis for short-term diversity variation in the Mesozoic terrestrial realm.
Social cues of sperm competition influence accessory reproductive gland size in a promiscuous mammal
Authors: Lemaître Jean-François , Ramm Steven A. , Hurst Jane L. , Stockley Paula
Published: September 2010

Theory predicts that males should increase overall investment in ejaculate expenditure with increasing levels of sperm competition. Since ejaculate production is costly, we may expect males to tailor their reproductive investment according to anticipated levels of sperm competition. Here, we investigate plasticity in ejaculate investment in response to cues of population average levels of sperm competition in a promiscuous mammal, the bank vole (
Myodes glareolus
). We manipulated the social experience of experimental subjects during sexual development via differential exposure to the odour of rival males, to simulate conditions associated with relatively high or low average levels of sperm competition. Males exposed to a high level of competition developed larger major accessory reproductive glands (seminal vesicles) than those that experienced a low level of competition, suggesting that an increased investment in the production of copulatory plugs and/or mating rate may be beneficial at relatively high sperm competition levels. However, investment in sperm production, testis size and sperm motility were not altered according to social experience. Our findings emphasize the importance of non-sperm components of the ejaculate in mammalian postcopulatory sexual selection, and add to the growing evidence linking plasticity in reproductive traits to social cues of sperm competition.
Modelling effects of diquat under realistic exposure patterns in genetically differentiated populations of the gastropodLymnaea stagnalis
Authors: Ducrot Virginie , Péry Alexandre R. R. , Lagadic Laurent
Published: September 2010

Pesticide use leads to complex exposure and response patterns in non-target aquatic species, so that the analysis of data from standard toxicity tests may result in unrealistic risk forecasts. Developing models that are able to capture such complexity from toxicity test data is thus a crucial issue for pesticide risk assessment. In this study, freshwater snails from two genetically differentiated populations ofLymnaea stagnaliswere exposed to repeated acute applications of environmentally realistic concentrations of the herbicide diquat, from the embryo to the adult stage. Hatching rate, embryonic development duration, juvenile mortality, feeding rate and age at first spawning were investigated during both exposure and recovery periods. Effects of diquat on mortality were analysed using a threshold hazard model accounting for time-varying herbicide concentrations. All endpoints were significantly impaired at diquat environmental concentrations in both populations. Snail evolutionary history had no significant impact on their sensitivity and responsiveness to diquat, whereas food acted as a modulating factor of toxicant-induced mortality. The time course of effects was adequately described by the model, which thus appears suitable to analyse long-term effects of complex exposure patterns based upon full life cycle experiment data. Obtained model outputs (e.g. no-effect concentrations) could be directly used for chemical risk assessment.