bluuebunny/crossref_metadata_2025 huggingface dataset:
95 DEVELOPMENT OF PORCINE TWO-CELL EMBRYOS WITH OR WITHOUT ZONA PELLUCIDA AND SINGLE BLASTOMERES
Authors: Thanh D. N. Q. , Matsukawa K. , Kaneda M. , Akagi S. , Kanai Y. , Nagai T.
Published: December 2008

In the mouse, single blastomeres of the 2-cell embryos can develop into adult mice and occasionally both separated blastomeres can give rise to twin animals (reviewed by Tarkowski AK et al. 2001 Int. J. Dev. Biol. 45, 591–596). As a preliminary study for production of monozygotic twins from porcine 2-cell embryos, we investigated the effects of removal of zona pellucida and blastomere isolation at the 2-cell stage on subsequent development of parthenogenetic embryos. Oocytes with the first polar body were parthenogenetically activated after 44 h of in vitro maturation. Stimulated oocytes were then incubated in IVC-PyrLac (IVC medium with pyruvate and lactose) according to the method reported by Kikuchi K et al. (2002 Biol. Reprod. 66, 1033–1041). After 24 to 30 h of parthenogenetic activation, equally cleaved 2-cell embryos were selected and used for the experiments. Some 2-cell embryos were then treated with pronase to remove the zona pellucida and cultured individually as zona-free 2-cell embryos having 2 blastomeres in pair (ZF group), and single blastomeres were split from ZF group and cultured separately (SB group) in V-shaped microwells. In addition, intact 2-cell embryos were cultured individually without pronase treatment as a control group. After 24 h of in vitro culture, IVC-PyrLac was replaced by IVC-Glu (IVC with glucose). The blastocyst rates on Day 6 (Day 0 was defined as the day of electrical stimulation) in control, ZF, and SB groups did not differ (47.6, 50.0, and 42.1%, respectively). Nevertheless, blastocysts derived from the ZF (28.6 ± 3.0) and SB groups (25.9 ± 1.3) had a significantly lower total cell number than that of the control group (41.7 ± 3.2; P < 0.01 by ANOVA). Although the total cell number of blastocysts originating from single blastomeres was significantly lower than that in the intact embryos, the blastocyst formation rates were not different between them. This indicated the possibility of production of monozygotic twins from porcine 2-cell embryos divided into 2 single blastomeres. However, further research is needed to improve blastocyst quality descended from single blastomeres. In conclusion, the removal of the zona pellucida had a negative influence on blastocyst quality but did not affect the development of porcine embryos to the blastocyst stage.
A redox-sensitive peroxiredoxin that is important for longevity has tissue- and stress-specific roles in stress resistance
Authors: Oláhová Monika , Taylor Sarah R. , Khazaipoul Siavash , Wang Jinling , Morgan Brian A. , Matsumoto Kunihiro , Blackwell T. Keith , Veal Elizabeth A.
Published: December 2008

Oxidative damage caused by reactive oxygen species (ROS) is implicated in many diseases and in aging. Removal of ROS by antioxidant enzymes plays an important part in limiting this damage. For instance, peroxiredoxins (Prx) are conserved, abundant, thioredoxin peroxidase enzymes that function as tumor suppressors. In addition to detoxifying peroxides, studies in single-cell systems have revealed that Prx act as chaperones and redox sensors. However, it is unknown in what manner the different activities of Prx influence stress resistance or longevity in the context of whole animals. Here, we reveal three distinct roles for the 2-Cys Prx, PRDX-2, in the stress resistance of the nematode worm
Caenorhabditis elegans
. (
i
) The thioredoxin peroxidase activity of PRDX-2 protects against hydrogen peroxide. (
ii
) Consistent with a chaperone activity for hyperoxidized PRDX-2, peroxide-induced oxidation of PRDX-2 increases resistance to heat stress. (
iii
) Unexpectedly, loss of PRDX-2 increases the resistance of
C. elegans
to some oxidative stress-causing agents, such as arsenite, apparently through a signaling mechanism that increases the levels of other antioxidants and phase II detoxification enzymes. Despite their increased resistance to some forms of oxidative stress,
prdx-2
mutants are short-lived. Moreover, intestinal expression of PRDX-2 accounts for its role in detoxification of exogenous peroxide, but not its influence on either arsenite resistance or longevity, suggesting that PRDX-2 may promote longevity and protect against environmental stress through different mechanisms. Together the data reveal that in metazoans Prx act through multiple biochemical activities, and have tissue-specific functions in stress resistance and longevity.
STN1 protects chromosome ends in
Arabidopsis thaliana
Authors: Song Xiangyu , Leehy Katherine , Warrington Ross T. , Lamb Jonathan C. , Surovtseva Yulia V. , Shippen Dorothy E.
Published: December 2008

Telomeres shield the natural ends of chromosomes from nucleolytic attack, recognition as double-strand breaks, and inappropriate processing by DNA repair machinery. The trimeric Stn1/Ten1/Cdc13 complex is critical for chromosome end protection in
Saccharomyces cerevisiae
, while vertebrate telomeres are protected by shelterin, a complex of six proteins that does not include STN1 or TEN1. Recent studies demonstrate that Stn1 and Ten1 orthologs in
Schizosaccharomyces pombe
contribute to telomere integrity in a complex that is distinct from the shelterin components, Pot1 and Tpp1. Thus, chromosome-end protection may be mediated by distinct subcomplexes of telomere proteins. Here we report the identification of a
STN1
gene in
Arabidopsis
that is essential for chromosome-end protection. AtSTN1 encodes an 18-kDa protein bearing a single oligonucleotide/oligosaccharide binding fold with significant sequence similarity to the yeast Stn1 proteins. Plants null for AtSTN1 display an immediate onset of growth and developmental defects and reduced fertility. These outward phenotypes are accompanied by catastrophic loss of telomeric and subtelomeric DNA, high levels of end-to-end chromosome fusions, increased G-overhang signals, and elevated telomere recombination. Thus, AtSTN1 is a crucial component of the protective telomere cap in
Arabidopsis
, and likely in other multicellular eukaryotes.
Modulation of RNA polymerase II subunit composition by ubiquitylation
Authors: Daulny Anne , Geng Fuqiang , Muratani Masafumi , Geisinger Jonathan M. , Salghetti Simone E. , Tansey William P.
Published: December 2008

Emerging evidence suggests that components of the ubiquitin–proteasome system are involved in the regulation of gene expression. A variety of factors, including transcriptional activators, coactivators, and histones, are controlled by ubiquitylation, but the mechanisms through which this modification can function in transcription are generally unknown. Here, we report that the
Saccharomyces cerevisiae
protein Asr1 is a RING finger ubiquitin-ligase that binds directly to RNA polymerase II via the carboxyl-terminal domain (CTD) of the largest subunit of the enzyme. We show that interaction of Asr1 with the CTD depends on serine-5 phosphorylation within the CTD and results in ubiquitylation of at least 2 subunits of the enzyme, Rpb1 and Rpb2. Ubiquitylation by Asr1 leads to the ejection of the Rpb4/Rpb7 heterodimer from the polymerase complex and is associated with inactivation of polymerase function. Our data demonstrate that ubiquitylation can directly alter the subunit composition of a core component of the transcriptional machinery and provide a paradigm for how ubiquitin can influence gene activity.
Experimental evidence that human impacts drive fire ant invasions and ecological change
Authors: King Joshua R. , Tschinkel Walter R.
Published: December 2008

Biological invasions are often closely associated with human impacts and it is difficult to determine whether either or both are responsible for the negative impacts on native communities. Here, we show that human activity, not biological invasion, is the primary driver of negative effects on native communities and of the process of invasion itself. In a large-scale experiment, we combined additions of the exotic fire ant,
Solenopsis invicta
, with 2 disturbance treatments, mowing and plowing, in a fully crossed factorial design. Results indicate that plowing, in the absence of fire ants, greatly diminished total native ant abundance and diversity, whereas fire ants, even in the absence of disturbance, diminished some, but not all, native ant abundance and diversity. Transplanted fire ant colonies were favored by disturbance. In the absence of disturbance and on their own, fire ants do not invade the forest habitats of native ants. Our results demonstrate that fire ants are “passengers” rather than “drivers” of ecological change. We propose that fire ants may be representative of other invasive species that would be better described as disturbance specialists. Current pest management and conservation strategies should be reassessed to better account for the central role of human impacts in the process of biological invasion.
Chromosome 15q25.1 genetic markers associated with level of response to alcohol in humans
Authors: Joslyn Geoff , Brush Gerry , Robertson Margaret , Smith Tom L. , Kalmijn Jelger , Schuckit Marc , White Raymond L.
Published: December 2008

As with other genetically complex common psychiatric and medical conditions, multiple genetic and environmental components contribute to alcohol use disorders (AUDs), which can confound attempts to identify genetic components. Intermediate phenotypes are often more closely correlated with underlying biology and have often proven invaluable in genetic studies. Level of response (LR) to alcohol is an intermediate phenotype for AUDs, and individuals with a low LR are at increased risk. A high rate of concurrent alcohol and nicotine use and dependence suggests that these conditions may share biochemical and genetic mechanisms. Genetic association studies indicate that a genetic locus, which includes the CHRNA5-CHRNA3-CHRNB4 gene cluster, plays a role in nicotine consumption and dependence. Genetic association with alcohol dependence was also recently shown. We show here that two of the markers from the nicotine studies also show an association (multiple testing correctedP< 0.025) with several LR phenotypes in a sample of 367 siblings. Additional markers in the region were analyzed and shown to be located in a 250-kb expanse of high linkage disequilibrium containing three additional genes. These findings indicate that LR intermediate phenotypes have utility in genetic approaches to AUDs and will prove valuable in the identification of other genetic loci conferring susceptibility to AUDs.
Rule of Law: A Comparison between Ancient Persia and Ancient Greece
Authors: Salehi-Esfahani Haideh
Published: December 2008

The ancient Persian empires are denoted as despotic, practicing arbitrary rule while Greece, Persia's archrival during the sixth to fourth century BC, exercised rule of law. This paper uses a contract theory framework to analyze some of the geographical and environmental underpinnings of the existence of rule of law in the city-states of ancient Greece and its absence in Persia. I discuss the role of geographical conditions of land (open plains versus mountains), population pressure, proximity to the sea and form of trade (overland versus overseas) as factors conducive to rule of law in the city-states of ancient Greece and to despotism in ancient Persia. Specifically, the role of trade via land in Persia prior to the fifth century BC is compared to the role of sea trade (alongside with piracy) in ancient Greece. I argue that in ancient Persia monarchs could tax or expropriate much of the gains from overland trade, preventing the accumulation of an independent form of wealth by merchants. In Greece, sea trade alongside the practice of piracy led to gains from trade that could not be easily expropriated by the monarchs and acted as a balancing force vis-à-vis the power of the monarchs, creating a basis for rule of law in the Greek city-states.
An essential role for the MAL protein in targeting Lck to the plasma membrane of human T lymphocytes
Authors: Antón Olga , Batista Alicia , Millán Jaime , Andrés-Delgado Laura , Puertollano Rosa , Correas Isabel , Alonso Miguel A.
Published: December 2008

The MAL protein is an essential component of the specialized machinery for apical targeting in epithelial cells. The src family kinase Lck plays a pivotal role in T cell signaling. We show that MAL is required in T cells for efficient expression of Lck at the plasma membrane and activation of IL-2 transcription. To investigate the mechanism by which MAL regulates Lck targeting, we analyzed the dynamics of Lck and found that it travels to the plasma membrane in specific transport carriers containing MAL. Coimmunoprecipitation experiments indicated an association of MAL with Lck. Both carrier formation and partitioning of Lck into detergent-insoluble membranes were ablated in the absence of MAL. Polarization of T cell receptor for antigen (TCR) and microtubule-organizing center to immunological synapse (IS) were also defective. Although partial correction of the latter defects was possible by forced expression of Lck at the plasma membrane, their complete correction, formation of transport vesicles, partitioning of Lck, and restoration of signaling pathways, which are required for IL-2 transcription up-regulation, were achieved by exogenous expression of MAL. We concluded that MAL is required for recruitment of Lck to specialized membranes and formation of specific transport carriers for Lck targeting. This novel transport pathway is crucial for TCR-mediated signaling and IS assembly.
Induction of inflammatory and immune responses by HMGB1–nucleosome complexes: implications for the pathogenesis of SLE
Authors: Urbonaviciute Vilma , Fürnrohr Barbara G. , Meister Silke , Munoz Luis , Heyder Petra , De Marchis Francesco , Bianchi Marco E. , Kirschning Carsten , Wagner Hermann , Manfredi Angelo A. , Kalden Joachim R. , Schett Georg , Rovere-Querini Patrizia , Herrmann Martin , Voll Reinhard E.
Published: December 2008

Autoantibodies against double-stranded DNA (dsDNA) and nucleosomes represent a hallmark of systemic lupus erythematosus (SLE). However, the mechanisms involved in breaking the immunological tolerance against these poorly immunogenic nuclear components are not fully understood. Impaired phagocytosis of apoptotic cells with consecutive release of nuclear antigens may contribute to the immune pathogenesis. The architectural chromosomal protein and proinflammatory mediator high mobility group box protein 1 (HMGB1) is tightly attached to the chromatin of apoptotic cells. We demonstrate that HMGB1 remains bound to nucleosomes released from late apoptotic cells in vitro. HMGB1–nucleosome complexes were also detected in plasma from SLE patients. HMGB1-containing nucleosomes from apoptotic cells induced secretion of interleukin (IL) 1β, IL-6, IL-10, and tumor necrosis factor (TNF) α and expression of costimulatory molecules in macrophages and dendritic cells (DC), respectively. Neither HMGB1-free nucleosomes from viable cells nor nucleosomes from apoptotic cells lacking HMGB1 induced cytokine production or DC activation. HMGB1-containing nucleosomes from apoptotic cells induced anti-dsDNA and antihistone IgG responses in a Toll-like receptor (TLR) 2–dependent manner, whereas nucleosomes from living cells did not. In conclusion, HMGB1–nucleosome complexes activate antigen presenting cells and, thereby, may crucially contribute to the pathogenesis of SLE via breaking the immunological tolerance against nucleosomes/dsDNA.
Oncogenic transformation in the absence of Xrcc4 targets peripheral B cells that have undergone editing and switching
Authors: Wang Jing H. , Alt Frederick W. , Gostissa Monica , Datta Abhishek , Murphy Michael , Alimzhanov Marat B. , Coakley Kristen M. , Rajewsky Klaus , Manis John P. , Yan Catherine T.
Published: December 2008

Nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks (DSBs) during V(D)J recombination in developing lymphocytes and during immunoglobulin (Ig) heavy chain (IgH) class switch recombination (CSR) in peripheral B lymphocytes. We now show that CD21-cre–mediated deletion of the Xrcc4 NHEJ gene in p53-deficient peripheral B cells leads to recurrent surface Ig-negative B lymphomas (“CXP lymphomas”). Remarkably, CXP lymphomas arise from peripheral B cells that had attempted both receptor editing (secondary V[D]J recombination of Igκ and Igλ light chain genes) and IgH CSR subsequent to Xrcc4 deletion. Correspondingly, CXP tumors frequently harbored a CSR-based reciprocal chromosomal translocation that fused IgH to c-myc, as well as large chromosomal deletions or translocations involving Igκ or Igλ, with the latter fusing Igλ to oncogenes or to IgH. Our findings reveal peripheral B cells that have undergone both editing and CSR and show them to be common progenitors of CXP tumors. Our studies also reveal developmental stage-specific mechanisms of c-myc activation via IgH locus translocations. Thus, Xrcc4/p53-deficient pro–B lymphomas routinely activate c-myc by gene amplification, whereas Xrcc4/p53-deficient peripheral B cell lymphomas routinely ectopically activate a single c-myc copy.
Factors Affecting Hospital-based Nurses' Willingness to Respond to a Radiation Emergency
Authors: Veenema Tener Goodwin , Walden Bonnie , Feinstein Nancy , Williams Jacqueline P.
Published: December 2008

Background: Despite increased government and public awareness of the threat of a radiological emergency resulting from a terrorist attack or industrial accident, limited emphasis has been placed on preparing the US health care workforce for such an event. The purpose of this study was to develop and apply a rapid survey to evaluate hospital-based nurses' baseline knowledge, self-assessed clinical competence, perception of personal safety, and willingness to respond in the event of a radiological emergency.

Methods: The study was conducted in 2 phases, the first targeting nursing units likely to respond in the event of a radiological emergency and the second focusing more generally on members of the New York State Emergency Nurses Association currently employed as hospital-based nurses.

Results: Among the 668 nurses surveyed, baseline knowledge was found to be inadequate. Although baseline knowledge, clinical competence, and perception of personal safety were all positively associated with willingness to respond, perception of safety appeared to be the primary determinant. Furthermore, baseline knowledge did not appear to be strongly associated with perception of personal safety.

Conclusions: Based on these results, the investigators recommend further clinical training to enhance preparedness and a more detailed exploration of the determinants of perceived personal safety. (Disaster Med Public Health Preparedness. 2008;2:224–229)
Implementation of Evidence-based Humanitarian Programs in Military-led Missions: Part I. Qualitative Gap Analysis of Current Military and International Aid Programs
Authors: Reaves Erik J. , Schor Kenneth W. , Burkle Frederick M.
Published: December 2008

Background:A recent Department of Defense instruction mandates country-specific assessments, identification of interventions, and development of guidance for Department of Defense to plan, train, and prepare for the provision of humanitarian assistance in stability operations. It also directs the use of outcome-based measures of effectiveness and the establishment of processes facilitating transparency of information. Whereas this would align military-led projects closer to the standards of the international aid community, how this process will be developed and implemented within the military has not yet been determined.

Methods:To begin developing an evidence-based program for military-led humanitarian aid, we conducted a qualitative gap analysis comparing information from a Web search of Department of Defense medical after-action reports, lessons learned, and expert interviews with the internationally accepted standards in humanitarian assistance impact assessment.

Results:There is a major gap in the ability of the Department of Defense to assess the impact of humanitarian assistance in stability operations compared with international development standards. Of the 1000 Department of Defense after-action reports and lessons learned reviewed, only 7 (0.7%) reports refer to, but do not discuss, impact assessment or outcome-based measures of effectiveness.

Conclusions:This investigation shows that the Department of Defense humanitarian assistance operations are, historically, recorded without documentation using quantifiable health data identifying which aid activities contributed directly to desired outcomes or favorable public opinion, and rarely are analyzed for effectiveness. As humanitarian assistance operations assume an ever greater role in US military strategy, it is imperative that we investigate useful impact assessment models to meet mission directives and, more important, to maximize coordination in a necessarily integrated and cooperative development environment. These findings provide baseline knowledge for the implementation of an evidence-based impact assessment process to validate future Department of Defense humanitarian assistance operations. (Disaster Med Public Health Preparedness. 2008;2:230–236)
Latent inhibition of predator recognition by embryonic amphibians
Authors: Ferrari Maud C.O , Chivers Douglas P
Published: December 2008

To avoid being captured, prey animals need to be able to distinguish predators from non-predators. Recent studies have shown that amphibians can learn to recognize their future predators while in the egg. Here, we investigated whether amphibians would similarly be able to learn to recognize non-predators while in the egg. We exposed newly laid wood frog eggs to the odour of tiger salamander or a water control daily for 5 days. After hatching, the wood frog larvae were raised for two weeks at which time we tried to condition them to recognize the salamander as a predator. Larvae were exposed to injured conspecific cues paired with salamander odour, a well-established mode of learning for aquatic prey. When subsequently tested for their response to salamander odour, the larvae pre-exposed to water as embryos showed significant anti-predator responses. However, larvae pre-exposed to the salamander odour as embryos showed no learning of the predator, indicating that they had already learned to recognize the salamander as a non-predator. These results indicate that amphibian embryos can (i) learn to recognize stimuli as non-threatening and (ii) remember it for at least two weeks. The widespread ability of prey to learn to recognize non-predators might explain the persistence of injured conspecific cues as a reliable mechanism for learned predator recognition.
A constant shear stress core flow model of the bidirectional vortex
Authors: Maicke Brian A , Majdalani Joseph
Published: December 2008

In this paper, we discuss the merits of two models for the swirl velocity in the core of a confined bidirectional vortex. The first is piecewise, Rankine-like, based on a combined-vortex representation. It stems from the notion that a uniform shear stress distribution may be assumed in the inner vortex region of a cyclone, especially at high Reynolds numbers. Thereafter, direct integration of the shear stress enables us to retrieve an expression for the swirl velocity that overcomes the inviscid singularity at the centreline. The second model consists of a modified asymptotic solution to the problem obtained directly from the Navier–Stokes equations. Both solutions we present transition smoothly to the outer, free-vortex approximation at some intermediate position in the chamber. This position is deduced from available experimental data to the extent of providing an accurate swirl velocity distribution throughout the chamber. By scaling the constant shear radius to the core layer thickness, the constant of proportionality is readily calculated using the method of least squares. Interestingly, the constant of proportionality is found to be invariant at several vortex Reynolds numbers, thus helping to achieve closure. The combined-vortex representation is validated against a large body of experimental measurements and through comparisons to a laminar core model that is enhanced through the use of an eddy viscosity. Other heuristic schemes are discussed and the two most suitable models to capture realistic flow behaviour at high vortex Reynolds numbers are identified. Our two models are first derived analytically and then anchored on the available experimental measurements.
Hand and paw preferences in relation to the lateralized brain
Authors: Rogers Lesley J
Published: December 2008

Hand preferences of primates are discussed as part of the broad perspective of brain lateralization in animals, and compared with paw preferences in non-primates. Previously, it has been suggested that primates are more likely to express a species-typical hand preference on complex tasks, especially in the case of coordinated hand use in using tools. I suggest that population-level hand preferences are manifested when the task demands the obligate use of the processing specialization of one hemisphere, and that this depends on the nature of the task rather than its complexityper se. Depending on the species, simple reaching tasks may not demand the obligate use of a specialized hemisphere and so do not constrain limb/hand use. In such cases, individuals may show hand preferences that are associated with consistent differences in behaviour. The individual's hand preference is associated with the expression of behaviour controlled by the hemisphere contralateral to the preferred hand (fear and reactivity in left-handed individuals versus proactivity in right-handed individuals). Recent findings of differences in brain structure between left- and right-handed primates (e.g. somatosensory cortex in marmosets) have been discussed and related to potential evolutionary advances.
Intraspecific competition and coordination in the evolution of lateralization
Authors: Ghirlanda Stefano , Frasnelli Elisa , Vallortigara Giorgio
Published: December 2008

Recent studies have revealed a variety of left–right asymmetries among vertebrates and invertebrates. In many species, left- and right-lateralized individuals coexist, but in unequal numbers (‘population-level’ lateralization). It has been argued that brain lateralization increases individual efficiency (e.g. avoiding unnecessary duplication of neural circuitry and reducing interference between functions), thus counteracting the ecological disadvantages of lateral biases in behaviour (making individual behaviour more predictable to other organisms). However, individual efficiency does not require a definite proportion of left- and right-lateralized individuals. Thus, such arguments do not explain population-level lateralization. We have previously shown that, in the context of prey–predator interactions, population-level lateralization can arise as an evolutionarily stable strategy when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Here, we extend our model showing that populations consisting of left- and right-lateralized individuals in unequal numbers can be evolutionarily stable, based solely on strategic factors arising from the balance between antagonistic (competitive) and synergistic (cooperative) interactions.
Determining the function of zebrafish epithalamic asymmetry
Authors: Facchin Lucilla , Burgess Harold A , Siddiqi Mahmud , Granato Michael , Halpern Marnie E
Published: December 2008

As in many fishes, amphibians and reptiles, the epithalamus of the zebrafish,Danio rerio, develops with pronounced left–right (L–R) asymmetry. For example, in more than 95 per cent of zebrafish larvae, the parapineal, an accessory to the pineal organ, forms on the left side of the brain and the adjacent left habenular nucleus is larger than the right. Disruption of Nodal signalling affects this bias, producing equal numbers of larvae with the parapineal on the left or the right side and corresponding habenular reversals. Pre-selection of live larvae using fluorescent transgenic reporters provides a useful substrate for studying the effects of neuroanatomical asymmetry on behaviour. Previous studies had suggested that epithalamic directionality is correlated with lateralized behaviours such as L–R eye preference. We find that the randomization of epithalamic asymmetry, through perturbation of thenodal-related genesouthpaw, does not alter a variety of motor behaviours, including responses to lateralized stimuli. However, we discovered significant deficits in swimming initiation and in the total distance navigated by larvae with parapineal reversals. We discuss these findings with respect to previous studies and recent work linking the habenular region with control of the motivation/reward pathway of the vertebrate brain.
Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry
Authors: Signore Iskra A , Guerrero Néstor , Loosli Felix , Colombo Alicia , Villalón Aldo , Wittbrodt Joachim , Concha Miguel L
Published: December 2008

Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115–200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal–habenular–interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left–right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates.
Mechanisms and functions of brain and behavioural asymmetries
Authors: Tommasi Luca
Published: December 2008

For almost a century the field of brain and behavioural asymmetries has been dominated by studies on humans, resting on the evidence that the anatomical structures underlying language functions are asymmetrical, and that human handedness is lateralized at the population level. Today, there is not only evidence of population-level lateralization of brain and behaviour across a variety of vertebrate and invertebrate species, but also a growing consensus that the comparative analysis of the environmental and developmental factors that give origin to neural and behavioural laterality in animal models, together with theoretical analyses of their costs and benefits, will be crucial for understanding the evolutionary pathways that led to such a multifaceted phenomenon. The present theme issue provides a survey of theoretical, review and research work cutting across the biological and the cognitive sciences, focusing on various species of fishes, birds and primates (including humans) and emphasizing an integrative approach to the study of lateralization encompassing neural, behavioural, cognitive, developmental and environmental aspects.
An update on the assessment and management of the risk of transmission of variant Creutzfeldt‐Jakob disease by blood and plasma products
Authors: Turner Marc L. , Ludlam Christopher A.
Published: December 2008

There have been four highly probable instances of variant Creutzfeldt‐Jakob disease (vCJD) transmission by non‐leucocyte depleted red cell concentrates and it is now clear that the infectious agent is transmissible by blood components. To date there in no reported evidence that the infectious agent has been transmitted by fractionated plasma products, e.g. factor VIII concentrate. This review outlines current and potential risk management strategies including donor deferral criteria, the potential for donor screening, blood component processing and prion reduction filters, plasma product manufacture and the difficulties in identification and notification of those considered ‘at risk of vCJD for public health purposes’.
Hannibal and The Alps: unravelling the invasion route
Authors: Mahaney W.C. , Kapran Barbara , Tricart Pierre
Published: December 2008

Over the last two millennia all the proposed invasion routes followed by the Punic Army in 218 bc have been based on historical and topographic analysis provided by Polybius and Livy, the two main ancient sources. Because Polybius actually followed the invasion route 60 years after the trek he is considered the prime authority. Livy never left his residence in Padua and studied the invasion from sources no longer available to us. Neither source provides a name for the approach route and ultimate col of transit into Italia but Polybius does state the col is the highest in the Alps' tas hyperbolas tas anōtatō tōn Alpéon. Several other ancient authors including Varro, Servius and Strabo list the cols from south to north as Col de Larche, Hannibal's Pass, Col de Montgenèvre and Col de Mt Cenis, thus limiting Hannibal's Pass to one of the three major cols south of the Col de Montgenèvre, which are from south to north, Col Agnel, Col de la Traversette and Col de la Croix. Invoking available geological and environmental evidence tied to descriptions in the ancient literature it is apparent Hannibal, either by design or happenstance, approached the Alps through the Queyras, the ultimate col of passage being the Col de la Traversette at nearly 3000 m above sea level. The implications of this find for geoarchaeology are enormous and offer the opportunity to find artefacts that will undoubtedly offer new insights into the military culture of ancient Carthage.
Scanning laser polarimetry – a review
Authors: Da Pozzo Stefano , Marchesan Roberta , Ravalico Giuseppe
Published: December 2008

Abstract

Glaucoma is a leading cause of irreversible blindness worldwide. Retinal ganglion cells and their axons represent the selective target of the disease. When visual function is still intact on standard automated perimetry and optic disc appearance is suspicious, an early diagnosis may be supported by the identification of a retinal nerve fibre layer (RNFL) defect in the peripapillary area. At present days, computer‐based, real‐time imaging of the peripapillary RNFL is available through instruments of easy use and with high levels of accuracy and reproducibility. Scanning laser polarimetry is performed by a confocal scanning laser ophthalmoscope with an integrated polarimeter (GDx‐VCC). There is a considerable amount of scientific evidence about the role of this imaging technique for glaucoma diagnosis. The aim of this review is to describe the principles of operation, the examination procedure, the clinical role, the results of main diagnostic studies and the future development of the software for the scanning laser polarimetry.
High‐resolution ultrasound imaging of the eye – a review
Authors: Silverman Ronald H
Published: December 2008

Abstract

This report summarizes the physics, technology and clinical application of ultrasound biomicroscopy (UBM) of the eye, in which frequencies of 35 MHz and above provide over a threefold improvement in resolution compared with conventional ophthalmic ultrasound systems. UBM allows imaging of anatomy and pathology involving the anterior segment, including regions obscured by overlying optically opaque anatomic or pathologic structures. UBM provides diagnostically significant information in conditions such as glaucoma, cysts and neoplasms, trauma and foreign bodies. UBM also can provide crucial biometric information regarding anterior segment structures, including the cornea and its constituent layers and the anterior and posterior chambers. Although UBM has now been in use for over 15 years, new technologies, including transducer arrays, pulse encoding and combination of ultrasound with light, offer the potential for significant advances in high‐resolution diagnostic imaging of the eye.
Radiographic surveillance of minimally and moderately complex renal cysts
Authors: Gabr Ahmed H. , Gdor Yehoshua , Roberts William W. , Wolf Jr J. Stuart
Published: December 2008

OBJECTIVE

To assess the effectiveness of radiographic surveillance for managing minimally and moderately complex renal cysts.

PATIENTS AND METHODS

Forty‐three patients with 50 minimally or moderately complex renal cysts underwent radiographic surveillance at our institution. Study inclusion criteria were surveillance for >2 years (36 patients, mean follow‐up 3.0 years) or surveillance for >6 months with subsequent surgical excision (seven patients, mean follow‐up 3.3 years).

RESULTS

The complexity of the renal cysts was in the form of high attenuation before contrast‐enhanced imaging (‘hyperdense’) in 29 patients, thin septations in nine, borderline enhancement in six, thin calcifications in five, and a thick wall in one. The mean initial largest dimension was 2.9 cm and the mean final dimension was 3.0 cm, with the size increased in 29 cysts, decreased in 14 and with no change in seven. The cyst character worsened in seven patients, improved in four and did not change in 39. Eventually seven patients had surgery (laparoscopic partial nephrectomy in five and laparoscopic radical nephrectomy in two), which revealed renal cancer in five. Surgical intervention was prompted by growth alone in two patients, growth and worsening of cyst characteristics in two, new onset of flank pain in one, and appearance of an enhancing nodule in the wall or septa in two.

CONCLUSION

Radiographic surveillance is an effective method for managing patients with minimally or moderately complex renal cysts. Malignant lesions can be identified and removed while still of low grade and contained, and surgery can be avoided in most patients.
Lymphovascular invasion predicts poor outcome of urothelial carcinoma of renal pelvis after nephroureterectomy
Authors: Chung Shiu‐Dong , Wang Shuo‐Meng , Lai Ming‐Kuen , Huang Chao‐Yuan , Liao Chun‐Hou , Huang Kuo‐How , Pu Yeong‐Shiau , Chueh Shih‐Chieh , Yu Hong‐Jeng
Published: December 2008

OBJECTIVE

To evaluate the significance of lymphovascular invasion (LVI) to predict cancer‐specific survival (CSS) in patients with renal pelvic urothelial carcinoma (UC).

PATIENTS AND METHODS

In all, 76 patients with primary renal pelvic UC were treated by nephroureterectomy (NU). Inclusion criteria included nonmetastatic renal pelvic UC with no previous history of bladder cancer, concomitant ureteric lesion, or neoadjuvant chemotherapy. Age, gender, adrenalectomized or not, pathological T stage, grade, and LVI were examined by univariate and multivariate analyses to determine which were independent risk factors.

RESULTS

In all, 38 men and 38 women were included with a mean (range) age of 66 (41–93) years. The median (range) follow‐up was 48  (15–88) months. At follow‐up, eight cancer‐related deaths (10.5%) were censored, and 66 patients (85.9%) were alive and disease‐free. LVI was the only significant predictor of CSS in the univariate and multivariate analyses.

CONCLUSIONS

Adrenal metastases from primary renal pelvic UCs were rare. The present results suggest that ipsilateral adrenalectomy is not necessary during radical NU for treating patients with renal pelvic UCs. LVI appears to be a better prognostic factor for predicting poor outcome of renal pelvic UC than pT stage or tumour grade when using the current tumour‐nodes‐metastases staging system.
ON AN APPROXIMATE OPTIMALITY CRITERION FOR THE DESIGN OF FIELD EXPERIMENTS UNDER SPATIAL DEPENDENCE
Authors: Butler David G. , Eccleston John A. , Cullis Brian R.
Published: December 2008

The design of large‐scale field trials where the residuals are correlated has been of recent interest, in large part because of advances in statistical and computational methods of analysis. The construction of designs for correlated data has typically used A‐optimality and is computationally intensive. This involves calculating the inverse of the information matrix for treatments under the supervision of an optimization strategy that explores the design space. We propose an approximation to A‐optimality, using nearest‐neighbour balance, that is less computationally demanding and can achieve at least 95% efficiency relative to A‐optimality in many practical situations.
EXACT P‐VALUES FOR DISCRETE MODELS OBTAINED BY ESTIMATION AND MAXIMIZATION
Authors: Lloyd Chris J.
Published: December 2008

In constructing exact tests from discrete data, one must deal with the possible dependence of the P‐value on nuisance parameter(s) ψ as well as the discreteness of the sample space. A classical but heavy‐handed approach is to maximize over ψ. We prove what has previously been understood informally, namely that maximization produces the unique and smallest possible P‐value subject to the ordering induced by the underlying test statistic and test validity. On the other hand, allowing for the worst case will be more attractive when the P‐value is less dependent on ψ. We investigate the extent to which estimating ψ under the null reduces this dependence. An approach somewhere between full maximization and estimation is partial maximization, with appropriate penalty, as introduced by Berger & Boos (1994, P values maximized over a confidence set for the nuisance parameter. J. Amer. Statist. Assoc. 89, 1012–1016). It is argued that estimation followed by maximization is an attractive, but computationally more demanding, alternative to partial maximization. We illustrate the ideas on a range of low‐dimensional but important examples for which the alternative methods can be investigated completely numerically.
A Statistical Model For Natural Gas Standardized Load Profiles
Authors: Brabec Marek , Konár Ondřej , Malý Marek , Pelikán Emil , Vondráček Jiří
Published: December 2008

We present a statistical model for construction and application of standardized load profiles. Standardized load profile curves give a typical natural gas consumption pattern throughout a year in various time resolutions. Our semiparametric regression model uses three types of information, constant characteristics of an individual customer, individual historical consumption and time varying explanatory variables, both to describe typical trend and to correct for departure of current conditions from normal. The model’s multiplicative structure allows for convenient separation of individual-specific and common time varying parts. Although corrections are parametric, no substantial information about the typical consumption trend is available, so it is modelled non-parametrically. Corrections for temperature effects are non-linear; hence we deal with them through an obvious extension of the generalized additive model framework.
Social Representations Theory: A Progressive Research Programme for Social Psychology
Authors: BAUER MARTIN W. , GASKELL GEORGE
Published: December 2008

The study “Psychoanalysis—its image and its public” intimates that common sense is increasingly informed by science. But common sense asserts its autonomy and, in turn, may affect the trajectory of science. This is a process that leads to many differentiations—in common sense, in scientific innovation and in political and regulatory structures. Bauer and Gaskell's toblerone model of triangles of mediation provided a distillation of their reading of “La Psychanalyse.” Here it was argued that representations are multi‐modal phenomena necessitating the use of multiple methodologies (comparative and longitudinal; qualitative and quantitative).

In this paper we briefly summarise these arguments and elaborate ways in which social representation theory can be considered a progressive research programme. “Progressive” because as the theory has developed it has extended the range and depth of its conceptual basis; it provides a new synthesis for the social scientific understanding of the phenomena of common sense and of representation; it acts as an antidote to the reductionism of public opinion and, finally, it is a stimulus to depart from disciplinary silos. However, there remain unresolved issues: how to segment the relevant social milieus and how to close the feedback loop from common sense to science?
Constraints on the early metamorphic evolution of Broken Hill, Australia, from in situ U‐Pb dating and REE geochemistry of monazite
Authors: McFARLANE C. R. M. , FROST B. R.
Published: December 2008

The Broken Hill Pb‐Zn deposit, New South Wales Australia, is hosted in granulite facies gneisses of the Southern Curnamona Province (SCP) that have long been known to record a polydeformational and polymetamorphic history. The details of this potentially prolonged tectonothermal history have remained poorly understood because of a historical emphasis on conventional (i.e. grain mount) U‐Pb zircon geochronology to reveal details of the sedimentary, magmatic and metamorphic history of the rock that crops out in the vicinity of the city of Broken Hill. An alternative approach to unravelling the metamorphic history of the granulite facies gneisses in and around Broken Hill is to date accessory minerals, such as monazite, that participate in sub‐solidus metamorphic reactions. We have taken advantage of the high spatial resolution and high sensitivity afforded by SHRIMP monazite geochronology to reconstruct the early history of the metamorphic rocks at Broken Hill. In contrast to previous studies, in situ analysis of monazite grains preserved in their original textural context in polished thin sections is used. Guided by electron microprobe X‐ray maps, SHRIMP U‐Pb dates for three distinct monazite compositional domains record pulses of monazite growth at c. 1657 Ma, c.1630 Ma and c.1602 Ma. It is demonstrated that these ages correspond to monazite growth during lower amphibolite facies, upper amphibolite facies and granulite facies metamorphism, respectively. It is speculated that this progressive heating of the SCP crust may have been driven by inversion of the upper crust during the Olarian Orogeny that was pre‐heated by magmatic underplating at c.1657 Ma.