bluuebunny/crossref_metadata_2025 huggingface dataset:
A recoding element that stimulates decoding of UGA codons by Sec tRNA[Ser]Sec
Authors: Howard Michael T. , Moyle Mark W. , Aggarwal Gaurav , Carlson Bradley A. , Anderson Christine B.
Published: April 2007

Selenocysteine insertion during decoding of eukaryotic selenoprotein mRNA requires several trans-acting factors and a cis-acting selenocysteine insertion sequence (SECIS) usually located in the 3′ UTR. A second cis-acting selenocysteine codon redefinition element (SRE) has recently been described that resides near the UGA-Sec codon of selenoprotein N (SEPN1). Similar phylogenetically conserved elements can be predicted in a subset of eukaryotic selenoprotein mRNAs. Previous experimental analysis of the SEPN1 SRE revealed it to have a stimulatory effect on readthrough of the UGA-Sec codon, which was not dependent upon the presence of a SECIS element in the 3′ UTR; although, as expected, readthrough efficiency was further elevated by inclusion of a SECIS. In order to examine the nature of the redefinition event stimulated by the SEPN1 SRE, we have modified an experimentally tractable in vitro translation system that recapitulates efficient selenocysteine insertion. The results presented here illustrate that the SRE element has a stimulatory effect on decoding of the UGA-Sec codon by both the methylated and unmethylated isoforms of Sec tRNA[Ser]Sec, and confirm that efficient selenocysteine insertion is dependent on the presence of a 3′-UTR SECIS. The variation in recoding elements predicted near UGA-Sec codons implies that these elements may play a differential role in determining the amount of selenoprotein produced by acting as controllers of UGA decoding efficiency.
RNA-based affinity purification reveals 7SK RNPs with distinct composition and regulation
Authors: Hogg J. Robert , Collins Kathleen
Published: April 2007

Recent studies have uncovered an unanticipated diversity of noncoding RNAs (ncRNAs), although these studies provide limited insight into their biological significance. Numerous general methods for identification and characterization of protein interactions have been developed, but similar approaches for characterizing cellular ncRNA interactions are lacking. Here we describe RNA Affinity in Tandem (RAT), an original, entirely RNA tag-based method for affinity purification of endogenously assembled RNP complexes. We demonstrate the general utility of RAT by isolating RNPs assembled in vivo on ncRNAs transcribed by RNA polymerase II or III. Using RAT in conjunction with protein identification by mass spectrometry and protein–RNA interaction assays, we define and characterize previously unanticipated protein subunits of endogenously assembled human 7SK RNPs. We show that 7SK RNA resides in a mixed population of RNPs with different protein compositions and responses to cellular stress. Depletion of a newly identified 7SK RNP component, hnRNP K, alters the partitioning of 7SK RNA among distinct RNPs. Our results establish the utility of a generalizable RNA-based RNP affinity purification method and provide insight into 7SK RNP dynamics.
An Exact Approach for the Vehicle Routing Problem with Two-Dimensional Loading Constraints
Authors: Iori Manuel , Salazar-González Juan-José , Vigo Daniele
Published: April 2007

We consider a special case of the symmetric capacitated vehicle routing problem, in which a fleet of K identical vehicles must serve n customers, each with a given demand consisting in a set of rectangular two-dimensional weighted items. The vehicles have a two-dimensional loading surface and a maximum weight capacity. The aim is to find a partition of the customers into routes of minimum total cost such that, for each vehicle, the weight capacity is taken into account and a feasible two-dimensional allocation of the items into the loading surface exists.

The problem has several practical applications in freight transportation, and it is 𝒩𝒫-hard in the strong sense. We propose an exact approach, based on a branch-and-cut algorithm, for the minimization of the routing cost that iteratively calls a branch-and-bound algorithm for checking the feasibility of the loadings. Heuristics are also used to improve the overall performance of the algorithm. The effectiveness of the approach is shown by means of computational results.
Empirical Features of Congested Traffic States and Their Implications for Traffic Modeling
Authors: Schönhof Martin , Helbing Dirk
Published: April 2007

We address the controversial issue of traffic flow modeling, whether first-order, second-order, or other traffic models are best supported by empirical facts and theoretical considerations. This is done by a critical discussion of the pros and cons of the different theoretical approaches and by the analysis of a large set of empirical data with new evaluation techniques. Specifically, we investigate characteristic properties of the congested traffic states on a 30-km-long stretch of the German freeway A5 near Frankfurt/Main. Among the approximately 245 breakdowns of traffic flow at several different bottlenecks in 165 days, we have identified five different kinds of spatiotemporal congestion patterns and their combinations. Based on an “adaptive smoothing method” for the visualization of detector data, we also discuss particular features of breakdowns, such as signs of unstable traffic flow and the “boomerang effect,” which often seems to be caused by overtaking maneuvers of trucks. Controversial issues such as “synchronized flow” or stop-and-go waves are addressed as well. Our empirical results are compared with the implications of different theoretical concepts such as first-order traffic models and the phase diagram of congested traffic states predicted by some second-order models and the nonlocal, gas-kinetic based traffic model (GKT model). For a correct understanding of empirical observations such as the “general pattern,” it is important to consider particularities such as the fact that off-ramps can act as bottlenecks, when activated by downstream on-ramp bottlenecks. As sequences of off- and on-ramps generate different congestion patterns than single on-ramps, they must be treated as interconnected bottlenecks. Furthermore, our empirical results question Kerner’s three-phase theory.
Computer navigation versus conventional total knee replacement
Authors: Spencer J. M. , Chauhan S. K. , Sloan K. , Taylor A. , Beaver R. J.
Published: April 2007

We previously compared the component alignment in total knee replacement using a computer-navigated technique with a conventional jig-based method. We randomly allocated 71 patients to undergo either computer-navigated or conventional replacement. An improved alignment was seen in the computer-navigated group.

The patients were then followed up post-operatively for two years, using the Knee Society score, the Short Form-36 health survey, the Western Ontario and McMaster Universities osteoarthritis index, the Bartlett Patellar pain questionnaire and the Oxford knee score, to assess functional outcome.

At two years post-operatively 60 patients were available for assessment, 30 in each group and 62 patients completed a postal survey. No patient in either group had undergone revision. All variables were analysed for differences between the groups either by Student’s t-test or the Mann-Whitney U test. Differences between the two groups did not reach significance for any of the outcome measures at any time point. At two years postoperatively, the frequency of mild to severe anterior pain was not significantly different (p = 0.818), varying between 44% (14) for the computer-navigated group, and 47% (14) for the conventionally-replaced group. The Bartlett Patellar score and the Oxford knee score were also not significantly different (t-test p = 0.161 and p = 0.607, respectively).

The clinical outcome of the patients with a computer-navigated knee replacement appears to be no different to that of a more conventional jig-based technique at two years post-operatively, despite the better alignment achieved with computer-navigated surgery.
Alignment and orientation of the components in total knee replacement with and without navigation support
Authors: Kim Y.-H. , Kim J.-S. , Yoon S.-H.
Published: April 2007

Bilateral sequential total knee replacement was carried out under one anaesthetic in 100 patients. One knee was replaced using a CT-free computer-assisted navigation system and the other conventionally without navigation. The two methods were compared for accuracy of orientation and alignment of the components. There were 85 women and 15 men with a mean age of 67.6 years (54 to 83). Radiological and CT imaging was carried out to determine the alignment of the components. The mean follow-up was 2.3 years (2 to 3).

The operating and tourniquet times were significantly longer in the navigation group (p < 0.001). There were no significant pre- or post-operative differences between the knee scores of the two groups (p = 0.288 and p = 0.429, respectively). The results of imaging and the number of outliers for all radiological parameters were not statistically different (p = 0.109 to p = 0.920).

In this series computer-assisted navigated total knee replacement did not result in more accurate orientation and alignment of the components than that achieved by conventional total knee replacement.
Cardiology: Aspirin Resistance in Patients with Stable Coronary Artery Disease with and without a History of Myocardial Infarction
Authors: Dorsch Michael P , Lee Jin Sun , Lynch Donald R , Dunn Steven P , Rodgers Jo E , Schwartz Todd , Colby Emily , Montague Debbie , Smyth Susan S
Published: April 2007

Background:

Aspirin therapy is a cornerstone in the prevention of atherothrombotic events, but recurrent vascular events are estimated to occur in 8-18% of patients taking aspirin for secondary prevention after 2 years. Estimates of biologic aspirin resistance vary from 5% to 60%, depending on the assay used. However, the relationship between biologic measurements of aspirin resistance and adverse clinical events remains unclear.

Objective:

To determine whether patients with documented myocardial infarction (Ml) while on aspirin therapy (cases) were more likely to be aspirin resistant than were patients with coronary artery disease (CAD) who had no history of Ml (controls) and to assess clinical predictors of aspirin resistance in patients with stable CAD.

Methods:

This case-control study examined aspirin responses using the VerifyNow Aspirin Assay system in 50 cases and 50 controls who had taken a dose of aspirin within 48 hours of presentation to the clinic visit. Odds ratios were estimated to determine the association between aspirin resistance and MI, Independent predictors of aspirin resistance were determined using univariate and multivariate analyses.

Results:

An increase in the prevalence of aspirin resistance among cases (16% vs 12% in controls) was not observed (OR 1.40; 95% CI 0.45 to 4.37; p = 0.566). In the overall CAD population, female sex was independently associated with aspirin resistance (OR 4.01; 95% CI 1.15 to 13.92; p = 0.029).

Conclusions:

Additional large studies are required to understand whether biologically defined aspirin resistance is associated with increased risk for cardiovascular events, with special attention paid to sex differences.
Use of Bone Health Protocol to Identify and Prevent Bone Disease in Kidney and Pancreas Transplant Recipients
Authors: Taber David J , Ashcraft Elizabeth A , Baillie G Mark , Lawrence D Bart , Chavin Kenneth D , Baliga Prabhakar K
Published: April 2007

BACKGROUND:

Posttransplant bone disease is a well recognized and under-treated problem. The use of protocols within other populations has been shown to improve recognition and treatment of common disease states, but outcome studies involving the use of protocols within transplant patients are lacking.

OBJECTIVE:

To compare the appropriate screening for and the prevention and treatment of osteopenia and osteoporosis in transplant patients before and after a bone health protocol was implemented.

METHODS:

A retrospective analysis in a single institution was designed to determine whether the development and implementation of a comprehensive bone health protocol impacted disease outcomes in posttransplant kidney and simultaneous kidney—pancreas patients.

RESULTS:

There were 132 patients in the historical control group and 76 in the treatment group. The groups were well matched, with no statistically significant differences noted for any of the baseline characteristics that were compared, including the modifiable and nonmodifiable risk factors known to put a patient at increased risk for osteopenia or osteoporosis. Significantly more patients in the treatment group received proper screening and prevention compared with the historical control group (p < 0.001). Although more patients in the treatment group received proper bone disease treatment, this did not reach statistical significance (81% vs 66%; p < 0.22). Additionally, the dual energy X-ray absorptiometry scans were performed, on average, 19 days earlier in the treatment group, although this also did not achieve statistical significance (p = 0.149).

CONCLUSIONS:

The multidisciplinary development and implementation of a comprehensive bone health protocol improves the screening and prevention of osteopenia and osteoporosis within kidney and pancreas transplant recipients.

TRASFONDO:

La enfermedad ósea luego de un transplante de órganos es un problema conocido y que no es tratado adecuadamente. La utilización de protocolos en otras poblaciones ha demostrado mejorar el reconocimiento y tratamiento de enfermedades comunes pero no hay suficientes estudios de los resultados del uso de protocolos en pacientes con transplante de órganos.
Helping Relationships and Genetic Propensities: A Combinatoric Study of DRD2, Mentoring, and Educational Continuation
Authors: Shanahan Michael J. , Erickson Lance D. , Vaisey Stephen , Smolen Andrew
Published: April 2007

From conception to death, helping relationships promote positive development and enable people to surmount challenges in their lives. Is it the case that the negative consequences of a genetic propensity for risky behaviors can be attenuated by helping relationships (a G × E)? But is it also the case that people with such a genetic propensity are less likely to have helping relationships compared to people without such a propensity (a rGE)? We illustrate this complex pattern of gene–environment interplay by drawing on the National Longitudinal Study of Adolescent Health and a combinatoric analytic strategy. We focus on a gene associated with dopamine receptor type 2 (DRD2 TaqIA), student–mentor relationships, and educational continuation beyond secondary school. Results reveal that, for both white and black males, DRD2 A1+ (A1A1 and A1A2 genotypes) is associated with a decreased likelihood of school continuation compared to their counterparts with DRD2 A1–; mentors who are teachers compensate for this negative association (a G × E); and youth with DRD2 A1+ are less likely to have a mentor who is a teacher than their counterparts with DRD2 A1– (a rGE).
Religious Upbringing and Neuroticism in Dutch Twin Families
Authors: Willemsen Gonneke , Boomsma Dorret I.
Published: April 2007

Evidence for a relation between neuroticism and religion is scarce and inconsistent. The aims of the present study were to determine the association of religious upbringing with adult neuroticism scores and to examine the effect of religious upbringing on the heritability of neuroticism. As part of a longitudinal survey of twin families from the Netherlands Twin Register, data were collected on neuroticism and religious upbringing. Restricting the sample to persons aged 25 and over resulted in a sample of 4369 twins and 1304 siblings from 2698 families. Religious upbringing was significantly associated with neuroticism; in both men and women neuroticism levels were lower in those who had received a religious upbringing. There were no sex or twinsibling differences in neuroticism variances and covariances. Structural equation modeling showed differences in heritability between those with and without religious upbringing. In the group with religious upbringing, variation in neuroticism was determined for 41% by additive genetic factors and for the remaining 59% by unique environmental factors. In the group who had not received a religious upbringing, variation in neuroticism was determined for 55% by genetic factors, with evidence for both additive and nonadditive factors, and for the remaining 45% by unique environmental influences. In conclusion, having received a religious upbringing is associated with lower neuroticism scores and a lower heritability in adulthood.
Europe lost and found: Serbian cinema and EU integration
Authors: Dakovi Nevena
Published: April 2007

The concern of this article is to explore the ways Serbian national cinema and filmmakers portray Europe and specifically how Serbian film has engaged with the politics of Europeanization and the question of EU integration. With regard to film as well as culture generally, the politics
of Europeanization in Serbia has involved highlighting the cultural closeness of Europe as well as the recognition of Serbian as European cultural identity. In this article I focus on films made from the 1990s onwards, looking at the way filmmakers have often pre-empted political developments,
which has seen a shift from a politics of nationalism to one of Europeanization.
Challenging a Well Established Consent Norm?: One Time Consent for Biobank Research
Authors: Caulfield Timothy , Brown Russell , Meslin Eric M
Published: April 2007

Large-scale biobanks of human biological materials linked to medical records are emerging as critical tools in research to tease out the complex interactions between genes and the environment and in ongoing development of diagnosis, prevention, and treatment of human disease. The evidence for this promise is found in the rush to establish these repositories by countries (Australia, UK, Sweden, Estonia, and Singapore), research organizations (NCI biobanks), and patient care groups.
Words, frequencies, and texts (particularly Conrad): A stratified approach
Authors: Moon Rosamund
Published: April 2007

This paper describes a corpus methodology developed in the course of investigations of three small subcorpora of texts: fiction by Conrad, nineteenth-century accounts of exploration, and adventure fiction. Stemming from observations that both high and lower frequency words in text are of interest in relation to meaning and structure, a ‘stratified approach’ integrates different levels of frequency by grouping words in a text into a series of frequency bands, identified from a reference corpus, then examining the most recurrent words within each band. This approach shows up, in particular, the ways in which topic and theme are lexicalized, and connotative lexis is associated with lower frequencies. In addition to exemplifying the approach and demonstrating its applications, the paper argues that any set of words, identified as significant through frequency, still involves selection, and that information which is derived quantitatively should not be interpreted as if wholly objective.
Disordered collarettes and uncovered tables: Negative polarity as a stylistic device in Joyce's “Two Gallants”
Authors: Nørgaard Nina
Published: April 2007

This article examines the use of negative polarity as a stylistic device in James Joyce's short story, “Two Gallants” (1992 [1914]). The article begins with a brief account of various approaches to negative polarity, focusing in particular on theoretical paradigms that favour the pragmatic functions of negative constructions in context. After this theoretical overview, the various approaches are applied to an analysis of Joyce's story, in the course of which it is demonstrated that although negatives are not a salient feature of the text they are nevertheless a significant meaning-making resource worth considering in analyses of literature. In particular the article aims to demonstrate how the linguistic theory of polyphony known as ScaPoLine would be a useful tool for those who wish to understand and describe the various voices that are coded by negatives and the way negative polarity is, accordingly, at times intimately connected to focalisation and narrative perspective.
Shall I compare thee? Simile understanding and semantic categories
Authors: Fishelov David
Published: April 2007

The purpose of this article is to present a few research findings on the process of understanding simile, where special attention was given to the semantic relationship between its three major components: Tenor (hereafter T), Vehicle (hereafter V) and Predicate (hereafter P). By manipulating different degrees of conventionality among these three components and the explicit presence of a P, eight kinds of simile emerged (e.g. conventional T and V but with unconventional P). Questionnaires were formulated consisting of lists of sixteen similes, representing the eight kinds. Subjects were asked to provide a short interpretation of the given similes, to estimate whether the simile conveyed negative, positive or neutral connotations, and finally to grade the degree of difficulty they encountered in understanding it. Thus, for example, most subjects reported that (1) “John is like a snake” says that John is a cunning and dangerous person, that it conveys negative connotations and that they had no difficulty in understanding it. Other, more “difficult” similes got diversified answers. Thus, for example, some subjects claimed that they had difficulty in understanding a phrase like (2) “John is like the state of Israel,” and responses concerning its connotations and its specific meanings were more heterogeneous. One conclusion based on the results is that subjects tend to cling to existing semantic categories not only in understanding conventional similes (and, by implication, metaphors and symbols), but also when faced with highly novel ones.
Persistent Sodium Currents Participate in Fictive Locomotion Generation in Neonatal Mouse Spinal Cord
Authors: Zhong Guisheng , Masino Mark A. , Harris-Warrick Ronald M.
Published: April 2007

The persistent sodium current (INa(P)) has been implicated in the regulation of synaptic integration, intrinsic membrane properties, and rhythm generation in many types of neurons. We characterizedINa(P)in commissural interneurons (CINs) in the neonatal (postnatal days 0–3) mouse spinal cord; it is activated at subthreshold potentials, inactivates slowly, and can be blocked by low concentrations of riluzole. The role ofINa(P)in locomotor pattern generation was examined by applying riluzole during fictive locomotion induced by NMDA, serotonin, and dopamine or by stimulation of the cauda equina. Blockade ofINa(P)has marginal effects on the locomotion frequency but progressively weakens the rhythmic firing and locomotor-related membrane oscillation of CINs and motoneurons (MNs) and the locomotor-like bursts in ventral roots, until the motor pattern ceases. Riluzole directly affects the intrinsic firing properties of CINs and MNs, reducing their ability to fire repetitively during tonic depolarizations and raising their spike threshold. At the same time, riluzole has little effects on the strength of spike-evoked synaptic transmission onto CINs and MNs. Our results suggest thatINa(P)is essential for the generation of the locomotor pattern and acts in part by regulating the frequency of interneuron firing in the central pattern generator for locomotion.
Ambient Light Regulates Sodium Channel Activity to Dynamically Control Retinal Signaling
Authors: Ichinose Tomomi , Lukasiewicz Peter D.
Published: April 2007

The retinal network increases its sensitivity in low-light conditions to detect small visual inputs and decreases its sensitivity in bright-light conditions to prevent saturation. However, the cellular mechanisms that adjust visual signaling in the retinal network are not known. Here, we show that voltage-gated sodium channels in bipolar cells dynamically control retinal light sensitivity. In dim conditions, sodium channels amplified light-evoked synaptic responses mediated by cone pathways. Conversely, in bright conditions, sodium channels were inactivated by dopamine released from amacrine cells, and they did not amplify synaptic inputs, minimizing signal saturation. Our findings demonstrate that bipolar cell sodium channels mediate light adaptation by controlling retinal signaling gain.
The Triphasic Intrinsic Signal: Implications for Functional Imaging
Authors: Chen-Bee Cynthia H. , Agoncillo Teodora , Xiong Ying , Frostig Ron D.
Published: April 2007

Intrinsic signal optical imaging with red illumination (ISOI) is used extensively to provide high spatial resolution maps of stimulus-evoked hemodynamic-related signals as an indirect means to map evoked neuronal activity. This evoked signal is generally described as beginning with an undershoot or “dip” in signal that is faster, more transient, and weaker compared with the subsequent signal overshoot. In contrast, the evoked signal detected with blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is generally described as containing an undershoot after the initial dip and overshoot, even though it, too, detects hemodynamic-related signals and its first two phases appear complementary to those of ISOI. Here, we used ISOI with 635 nm illumination to image over 13.5 s after a 1 s stimulus delivery to detect and successfully use the ISOI undershoot phase for functional mapping. Eight spatiotemporal attributes were assessed per signal phase including maximum areal extent and peak magnitude, both of which were largest for the ISOI overshoot, followed by the undershoot and then the initial dip. Peak activity location did not colocalize well between the three phases; furthermore, we found mostly modest correlations between attributes within each phase and sparse correlations between phases. Extended (13.5 s) electrophysiology recordings did not exhibit a reoccurrence of evoked suprathreshold or subthreshold neuronal responses that could be associated with the undershoot. Beyond the undershoot, additional overshoot/undershoot fluctuations were also mapped, but were typically less spatiotemporally specific to stimulus delivery. Implications for ISOI and BOLD fMRI are discussed.
Upregulation of Polysialylated Neural Cell Adhesion Molecule in the Dorsal Hippocampus after Contextual Fear Conditioning Is Involved in Long-Term Memory Formation
Authors: Lopez-Fernandez Miguel A. , Montaron Marie-Françoise , Varea Emilio , Rougon Genevieve , Venero Cesar , Abrous Djoher Nora , Sandi Carmen
Published: April 2007

The role of the hippocampus in pavlovian fear conditioning is controversial. Although lesion and pharmacological inactivation studies have suggested a key role for the dorsal hippocampus in contextual fear conditioning, the involvement of the ventral part is still uncertain. Likewise, the debate is open with regard to the putative implication of each hippocampal subdivision in fear conditioning to a discrete conditioned stimulus. We explored the potential existence of dissociations occurring in the dorsal versus ventral hippocampus at the cellular level while dealing with either contextual or cued fear conditioning and focused in a molecular “signature” linked to structural plasticity, the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). We found an upregulation of PSA-NCAM expression in the dorsal (but not ventral) dentate gyrus at 24 h after contextual (but not tone) fear conditioning. Specific removal of PSA through microinfusion of the enzyme endoneuraminidase-N in the dorsal (but not ventral) hippocampus reduced freezing responses to the conditioned context. Therefore, we present evidence for a specific role of PSA-NCAM in the dorsal hippocampus in the plasticity processes occurring during consolidation of the context representation after “standard” contextual fear conditioning. Interestingly, we also found that exposing animals just to the context induced an activation of PSA-NCAM in both dorsal and ventral dentate gyrus. Altogether, these findings highlighting the distinctive occurrence of these neuroplastic processes in the dorsal hippocampus during the standard contextual fear-conditioning task enlighten the ongoing debate about the involvement of these hippocampal subdivisions in pavlovian fear conditioning.
Extensive Reorganization of Primary Afferent Projections into the Gustatory Brainstem Induced by Feeding a Sodium-Restricted Diet during Development: Less Is More
Authors: Mangold Jamie E. , Hill David L.
Published: April 2007

Neural development is especially vulnerable to environmental influences during periods of neurogenesis and rapid maturation. In fact, short periods of environmental manipulations confined to embryonic development lead to significant changes in morphology and function. A guiding principal emerging from studies of sensory systems is that experimentally induced effects are most dramatic in higher neural levels (e.g., cortex) and primarily involve postnatal synaptic refinements. In contrast to other sensory systems, the gustatory system is particularly susceptible to the effects of deprivation much earlier and with profound changes evident in the brainstem. Here we show that feeding pregnant rats a custom diet featuring a low-sodium content for 9 d before the tongue appears in the fetus produces extensive restructuring of the gustatory brainstem. Rats born to mothers fed the custom diet from embryonic day 3 (E3) to E12 have terminal field volumes of the greater superficial petrosal, chorda tympani, and glossopharyngeal nerves at adulthood that are expanded as much as 10 times beyond that found in rats fed a standard rat chow. The widespread alterations are not attributable to increased numbers of nerve cells, increased target size, or obvious changes in peripheral taste function. Moreover, we show that the limited period of feeding the custom diet has much larger effects than if rats were fed the diet to postweaning ages. Our results suggest that early periods of altered experience, especially during nucleus of the solitary tract neurogenesis, leads to a restructuring of the gustatory brainstem, which in turn may impact the control of sensory and homeostatic processes.
Compensatory Plasticity at an Identified Synapse Tunes a Visuomotor Pathway
Authors: Rogers Stephen M. , Krapp Holger G. , Burrows Malcolm , Matheson Thomas
Published: April 2007

We characterized homeostatic plasticity at an identified sensory-motor synapse in an insect, which maintains constant levels of motor drive as locusts transform from their solitarious phase to their gregarious swarming phase. The same mechanism produces behaviorally relevant changes in response timing that can be understood in the context of an animal's altered behavioral state. For individual animals of either phase, different looming objects elicited different spiking responses in a visual looming detector interneuron, descending contralateral movement detector (DCMD), yet its synaptic drive to a leg motoneuron, fast extensor tibiae (FETi), always had the same maximum amplitude. Gregarious locust DCMDs produced more action potentials and had higher firing frequencies, but individual postsynaptic potentials (PSPs) elicited in FETi were half the amplitude of those in solitarious locusts. A model suggested that this alone could not explain the similarity in overall amplitude, and we show that facilitation increased the maximum compound PSP amplitude in gregarious animals. There was the same linear relationship between times of peak DCMD firing before collision and the size/velocity of looming objects in both phases. The DCMD-FETi synapse transformed this relationship nonlinearly, such that peak amplitudes of compound PSPs occurred disproportionately earlier for smaller/faster objects. Furthermore, the peak PSP amplitude occurred earlier in gregarious than in solitarious locusts, indicating a differential tuning. Homeostatic modulation of the amplitude, together with a nonlinear synaptic transformation of timing, acted together to tune the DCMD-FETi system so that swarming gregarious locusts respond earlier to small moving objects, such as conspecifics, than solitarious locusts.
Localization of HCN1 Channels to Presynaptic Compartments: Novel Plasticity That May Contribute to Hippocampal Maturation
Authors: Bender Roland A. , Kirschstein Timo , Kretz Oliver , Brewster Amy L. , Richichi Cristina , Rüschenschmidt Christiane , Shigemoto Ryuichi , Beck Heinz , Frotscher Michael , Baram Tallie Z.
Published: April 2007

Increasing evidence supports roles for the current mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels,Ih, in hippocampal maturation and specifically in the evolving changes of intrinsic properties as well as network responses of hippocampal neurons. Here, we describe a novel developmental plasticity of HCN channel expression in axonal and presynaptic compartments: HCN1 channels were localized to axon terminals of the perforant path (the major hippocampal afferent pathway) of immature rats, where they modulated synaptic efficacy. However, presynaptic expression and functions of the channels disappeared with maturation. This was a result of altered channel transport to the axons, because HCN1 mRNA and protein levels in entorhinal cortex neurons, where the perforant path axons originate, were stable through adulthood. Blocking action potential firingin vitroincreased presynaptic expression of HCN1 channels in the perforant path, suggesting that network activity contributed to regulating this expression. These findings support a novel developmentally regulated axonal transport of functional ion channels and suggest a role for HCN1 channel-mediated presynapticIhin hippocampal maturation.
Functional Dissociation in Frontal and Striatal Areas for Processing of Positive and Negative Reward Information
Authors: Liu Xun , Powell David K. , Wang Hongbin , Gold Brian T. , Corbly Christine R. , Joseph Jane E.
Published: April 2007

Reward-seeking behavior depends critically on processing of positive and negative information at various stages such as reward anticipation, outcome monitoring, and choice evaluation. Behavioral and neuropsychological evidence suggests that processing of positive (e.g., gain) and negative (e.g., loss) reward information may be dissociable and individually disrupted. However, it remains uncertain whether different stages of reward processing share certain neural circuitry in frontal and striatal areas, and whether distinct but interactive systems in these areas are recruited for positive and negative reward processing. To explore these issues, we used a monetary decision-making task to investigate the roles of frontal and striatal areas at all three stages of reward processing in the same event-related functional magnetic resonance imaging experiment. Participants were instructed to choose whether to bet or bank a certain number of chips. If they decided to bank or if they lost a bet, they started over betting one chip. If they won a bet, the wager was doubled in the next round. Positive reward anticipation, winning outcome, and evaluation of right choices activated the striatum and medial/middle orbitofrontal cortex, whereas negative reward anticipation, losing outcome, and evaluation of wrong choices activated the lateral orbitofrontal cortex, anterior insula, superior temporal pole, and dorsomedial frontal cortex. These findings suggest that the valence of reward information and counterfactual comparison more strongly predict a functional dissociation in frontal and striatal areas than do various stages of reward processing. These distinct but interactive systems may serve to guide human's reward-seeking behavior.
Auf dem Weg in die Zukunft: Web 2.0 in Baden-Württemberg (Facing the Future: Web 2.0 in Baden-Wuerttemberg)
Authors: Hummel Corina
Published: April 2007

Im August 2006 wurde das Innovationsprogramm Web 2.0 gestartet, das bis Ende 2007 aus Mitteln des Medienimpulsprogramms des Staatsministeriums Baden-Württemberg unterstützt wird. Ziel ist es, die technischen, wirtschaftlichen und sozialen Potenziale in Baden-Württemberg auszuschöpfen und die Entwicklung innovativer Projekte im Land zu forcieren. Mit einer Veranstaltungsreihe in sieben baden-württembergischen Städten informierte die MFG Baden-Württemberg in der ersten Phase über die Möglichkeiten des Web 2.0 und präsentierte erfolgreiche Beispiele. Die vier Arbeitskreise Geschäftsmodelle, Leben online, Marketing & PR und Wissensmanagement analysieren in regelmäßigen Treffen verschiedene Aspekte des Web 2.0 und treiben konkrete Projekte voran. Langfristiges Ziel des Programms ist es, durch innovative Anwendungen und Geschäftsmodelle im Bereich Web 2.0 neue Dienstleistungen und Arbeitsplätze zu schaffen.
ZUI Konzepte für Navigation und Suche in komplexen Informationsräumen (ZUI Concepts for Navigating and Searching Complex Information Spaces)
Authors: Gundelsweiler Fredrik , Memmel Thomas , Reiterer Harald
Published: April 2007

Die Quantität, Dimensionalität und Multimedialität heutiger Informationsräume stellt bei der Suche, Exploration und Navigation große Anforderungen an die Gestaltung der Mensch-Computer Interaktion. Zoomable User Interfaces (ZUIs) bieten dabei neue Möglichkeiten für ein benutzergerechteres Design. Am Beispiel von ZUI Konzepten für die Navigation und Suche in digitalen Welten sollen neue Wege des Interaktionsdesigns aufgezeigt werden.
Herbert Butterfield, der Nationalsozialismus und die deutsche Geschichtswissenschaft
Authors: Steber Martina
Published: April 2007

Vorspann

Der Cambridge-Historiker Herbert Butterfield, bekannt geworden vor allem durch seinen 1931 erschienenen Angriff auf „The Whig Interpretation of History“, galt Zeit seines Lebens als ausgesprochen deutschfreundlich. Viele sahen in dem stark von Rankes Historismus geprägten, christlich und antiliberal orientierten Wissenschaftler sogar einen Sympathisanten des nationalsozialistischen Deutschland. Beruhte dieses Urteil nur auf Missverständnissen? War die Ausbildung einer konservativen Schule der britischen Nachkriegsgeschichtsschreibung von Butterfields wechselvoller Auseinandersetzung mit dem deutschen Weg in die Katastrophe beeinflusst? Und wie war das Verhältnis zwischen Butterfield und den nationalkonservativen Historikern in der Bundesrepublik Deutschland der 1950er und 1960er Jahre?
Análise Envoltória de Dados na avaliação de hospitais públicos nas capitais brasileiras
Authors: Gonçalves Antonio C , Noronha Cláudio P , Lins Marcos PE , Almeida Renan MVR
Published: April 2007

OBJETIVO: Aplicar a metodologia de Análise Envoltória de Dados na avaliação do desempenho de hospitais públicos em termos das internações em suas clínicas médicas. MÉTODOS: A eficiência dos hospitais foi medida a partir do desempenho de unidades de decisão nas variáveis estudadas para cada hospital, no ano 2000. Foram analisados dados referentes às internações em clínica médica dos hospitais SUS das capitais estaduais do Brasil e Distrito Federal (taxas de mortalidade e tempo médio de internação, valor médio da internação e perfil de doenças). A técnica de análise de correlação canônica foi introduzida na restrição do intervalo de variação das variáveis. O modelo Constant Returns to Scale foi utilizado para gerar escores que permitissem avaliar a eficiência das unidades. A partir dos escores obtidos, os municípios foram classificados de acordo com seu desempenho relativo nas variáveis analisadas. Procurou-se correlação entre os escores de classificação com variáveis exógenas: despesas com programas de saúde básica por habitante e índice de desenvolvimento humano das capitais. RESULTADOS: Nos hospitais estudados se destacaram as doenças do aparelho circulatório (23,6% das internações); e a taxa de mortalidade foi de 10,3% das internações. Das 27 capitais, quatro alcançaram 100% de eficiência (Palmas, Macapá, Teresina e Goiânia), sete ficaram entre 85% e 100%, dez entre 70% e 85% e dez com menos de 70%. CONCLUSÕES: A ferramenta utilizada mostrou ser aplicável para a avaliação de desempenho de hospitais públicos, revelando a grande variabilidade entre as capitais brasileiras, no que se refere às internações em clínica médica.
Sazonalidade de Aedes albopictus em área protegida na cidade de São Paulo, Brasil
Authors: Urbinatti Paulo Roberto , Menezes Regiane Maria Tironi de , Natal Delsio
Published: April 2007

O estudo teve por objetivo analisar a sazonalidade de Aedes albopictus e a influência de fatores ambientais em criadouros, em uma área urbana protegida. Foram realizadas coletas de indivíduos imaturos por sucção do líquido de nove ocos de árvores, no Parque Ecológico do Tietê, no Município de São Paulo, SP, de 2001 a 2002 . Os resultados do índice de positividade e do número de indivíduos foram: positividade x precipitação (ro=0,69; p<0,001); positividade x temperatura (ro=0,35; p<0,001); número de indivíduos x precipitação (ro=0,29; p<0,001) e número de indivíduos x temperatura (ro=0,13; p<0,05). As correlações sugerem que as chuvas foram mais influentes que a temperatura.
Morphometrical and molecular characterization of Bursaphelenchus species from Slovenia
Authors: Urek G. , Širca S. , Geric B.
Published: April 2007

The environmental conditions in Slovenia are relatively favourrable for the colonisation and spread of the pine wood nematode Bursaphelenchus xylophilus, a very dangerous pathogenic species which was recently identified in Europe in Portugal. To determine the presence of B. xylophilus in Slovenia and to introduce proper measures against its emergence and spread, a survey of Bursaphelenchus species was conducted in Slovenia from 2002 to 2005. Approximately 120 ha of conifer forests in Slovenia were surveyed for the presence of Bursaphelenchus species. In total, 206 wood samples were taken from the conifer forests. B. hofmanni, B. mucronatus were found for the first time in Slovenia, while B. xylophilus was not detected. Additionally, the species Aphelenchoides stammeri which is morphologically very similar to Bursaphelencus was found. All species have been described morphologically and characterized by ITS-RFLP analysis. Sequences of ribosomal DNA for B. hofmanni, B. mucronatus were analysed.
Sequences of the second internal transcribed spacer of ribosomal DNA for three species of Trichostrongylus (Nematoda: Trichostrongylidae) from sheep in Russia
Authors: Kuznetsov D. , Kuznetsova N.
Published: April 2007

For the first time, DNA sequence data were obtained for three species of Trichostrongylus from Russia. Internal transcribed spacer (ITS-2) of ribosomal DNA was sequenced for T. axei, T. colubriformis and T. probolurus from sheep from the Moscow region. ITS-2 rDNA length was estimated as 238 nucleotides for T. colubriformis and T. probolurus and 237 nucleotides for T. axei. The G+C content of the ITS-2 sequences of T. colubriformis, T. axei and T. probolurus were 31 %, 32 % and 34 % respectively. The level of interspecific differences in ITS-2 of rDNA of T. axei, T. probolurus and T. colubriformis ranged from 3 to 4 %. The ITS-2 sequences from the Russian specimens were compared with those of T. axei, T. probolurus and T. colubriformis from Australia and Germany. Intraspecific variation ranged from 0 % in T. colubriformis to 3.0 % in T. axei.
Comparative study of the intestinal strongylid communities of equidae in the Askania-Nova biosphere reserve, Ukraine
Authors: Kuzmina T. , Kharchenko V. , Zvegintsova N.
Published: April 2007

Comparative studies of the intestinal strongylid communities of 14 ponies, 6 donkeys and 9 zebras from the “Askania-Nova” Biosphere reserve (Ukraine) were carried out after deworming the hosts with aversectin drug. Faecal sampling (200 g each) was performed at 24, 36, 48, 60, and 72 hours after treatment; all nematodes expelled were collected and identified. Thirty strongylid species from 12 genera were found; 7 species from the Strongylinae and 23 species from Cyathostominae. In ponies 27 species were found (range 8–23; mean 14 ± 3.8). In donkeys 23 species were found (range 11–15; mean 12 ± 1.3). Cyathostomum tetracanthum a species specific for donkeys was found for the first time in Ukraine. In zebras 17 species were found (range 2–13; mean 7 ± 3.6). The results obtained confirmed the specificity of the intestinal strongylid fauna of different equid species grazing on the same pastures in the “Askania-Nova” reserve.
Communities of free living and plant parasitic nematodes in hop gardens in Slovakia
Authors: Lišková M. , Renčo M.
Published: April 2007

A total of 61 nematode species belonging into 48 genera was identified in soil of nine localities of hop gardens in Slovakia. From free living soil nematodes the most abundant were the genus Rhabditis-eudominant taxon, species Aphelenchus avenae — dominant taxon, the species Cephalobus persegnis, Chiloplacus propinquus, Aglenchus agricola, Nothotylenchus acris, Aporcelaimellus obtusicaudatus and genus Eudorylaimus were subdominant taxa. Only ten species of plant parasitic nematodes were observed — Ditylenchus dipsaci, Bitylenchus dubius, Merlinius brevidens, Rotylenchus robustus, Helicotylenchus canadensis, H. digonicus, Pratylenchus penetrans, P. pratensis, Heterodera humuli, and Paratylenchus bukowinensis. Bitylenchus dubius and Merlinius brevidens belonged to dominant taxa, the species Heterodera humuli and Helicotylenchus digonicus to subdominant taxa. The occurrence of Heterodera humuli cysts was recorded at all localities studied, and the occurrence of H. humuli larvae in soil during autumn indicates that possibly more than one generation of the parasite have developed within one vegetation period. The proportion of individual trophic groups in nematode communities of hop gardens was characterised by the prevalence of bacterial feeders followed by plant parasites. The ecological characteristics used for ecological evaluation, especially Maturity Index and Plant Parasitic Index/Maturity Index, indicate a more disturbed environment. Although hop is a perennial plant, the structure and ecology of its nematode communities is more similar to the agricultural ecosystems with a higher level of agricultural practices.
Soil nematode responses to heavy metal stress
Authors: Zhang W. , Wang X. , Li Q. , Jiang Y. , Liang W.
Published: April 2007

The effect of Cu and Zn on soil nematode communities at the depth of 0–20 cm was investigated along a pollution gradient with increasing distance from a copper smelter in Northeast China. The results showed that the abundance of total nematodes significantly increased with increasing distance from the smelter, and nematode taxon richness also exhibited an increasing trend. Twenty genera were observed in our study, and Paratylenchus was the dominant genus at all the sampling sites. The numbers of total nematodes, bacterivores, plant parasites, omnivores-predators and the values of NCR (Nematode Channel Ratio) negatively correlated with total Cu (P < 0.01), total and available Zn (P < 0.01). The values of SI (Structure Index) negatively correlated with total Cu (P < 0.05). Among the nematode ecological indices examined, NCR and SI were found to be sensitive indicators for assessing the effect of heavy metals on soil nematode communities in this study.