bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Indications for Thrombopoietin and Thrombopoietin-Receptor Agonists
Authors: Wörmann Bernhard
Published: September 2013

Thrombocytopenia is a common hematologic disorder. Stimulation of thrombopoiesis may reduce the risk for thrombocytopenia-induced bleeding, prevent severe thrombocytopenia, and reduce the need for platelet transfusion. The key cytokine is thrombopoietin (TPO). It regulates proliferation and maturation of megakaryocytes as well as platelet production. TPO is synthesized in the liver. Development of TPO from the laboratory into a therapeutic tool has turned out to be an unexpected challenge. Clinical trials on first-generation thrombopoietic growth factors were stopped in 2001. At present, second-generation thrombopoiesis-stimulating agents have only been approved as orphan drugs for third-line therapy of patients with chronic immune thrombocytopenia. Larger groups in need are patients with myelodysplastic syndrome, chemotherapy-induced thrombocytopenia, other forms of hereditary and acquired bone marrow failure, hepatitis C infections, or liver cirrhosis.
Ionic Mechanisms Underlying the Effects of Vasoactive Intestinal Polypeptide on Canine Atrial Myocardium
Authors: Xi Yutao , Wu Geru , Ai Tomohiko , Cheng Nancy , Kalisnik Jurij Matija , Sun Junping , Abbasi Shahrzad , Yang Donghui , Fan Christopher , Yuan Xiaojing , Wang Suwei , Elayda MacArthur , Gregoric Igor D. , Kantharia Bharat K. , Lin Shien-Fong , Cheng Jie
Published: September 2013

Background—

Vasoactive intestinal polypeptide (VIP) is released from intracardiac neurons during vagal stimulation, ischemia, and heart failure, which are associated with increased vulnerability to atrial fibrillation. VIP shortens atrial effective refractory periods in dogs. Endogenous VIP contributes to vagally mediated acceleration of atrial electric remodeling. VIP is also shown to prolong the duration of acetylcholine-induced atrial fibrillation. However, the ionic mechanisms underlying VIP effects are largely unknown.

Methods and Results—

The effects of VIP on transmembrane ion channels were studied in canine atrial cardiomyocytes using patch-clamp techniques. VIP increased delayed rectifier K
+
current and L-type calcium current but decreased the transient outward K
+
current and sodium current. Optical mapping technique was used to assess effects of VIP on action potential durations (APDs) in isolated canine left atria. VIP shortened APD and slowed conduction velocity in a dose-dependent manner. Furthermore, VIP increased spatial heterogeneity of APD and conduction velocity, as assessed by the SDs of APD and conduction velocity, and atrial fibrillation inducibility.

Conclusions—

Through its diverse effects on ion channels, VIP shortens APD with increased APD spatial heterogeneity and decreases intra-atrial conduction velocity, which may play an important role in the pathogenesis of atrial arrhythmias in scenarios where VIP release is increased.
A Variant in
LDLR
Is Associated With Abdominal Aortic Aneurysm
Authors: Bradley Declan T. , Hughes Anne E. , Badger Stephen A. , Jones Gregory T. , Harrison Seamus C. , Wright Benjamin J. , Bumpstead Suzannah , Baas Annette F. , Grétarsdóttir Sólveig , Burnand Kevin , Child Anne H. , Clough Rachel E. , Cockerill Gillian , Hafez Hany , Scott D. Julian A. , Ariëns Robert A.S. , Johnson Anne , Sohrabi Soroush , Smith Alberto , Thompson Matthew M. , van Bockxmeer Frank M. , Waltham Matthew , Matthíasson Stefán E. , Thorleifsson Gudmar , Thorsteinsdottir Unnur , Blankensteijn Jan D. , Teijink Joep A.W. , Wijmenga Cisca , de Graaf Jacqueline , Kiemeney Lambertus A. , Wild John B. , Edkins Sarah , Gwilliam Rhian , Hunt Sarah E. , Potter Simon , Lindholt Jes S. , Golledge Jonathan , Norman Paul E. , van Rij Andre , Powell Janet T. , Eriksson Per , Stefánsson Kári , Thompson John R. , Humphries Steve E. , Sayers Robert D. , Deloukas Panos , Samani Nilesh J. , Bown Matthew J.
Published: September 2013

Background—

Abdominal aortic aneurysm (AAA) is a common cardiovascular disease among older people and demonstrates significant heritability. In contrast to similar complex diseases, relatively few genetic associations with AAA have been confirmed. We reanalyzed our genome-wide study and carried through to replication suggestive discovery associations at a lower level of significance.

Methods and Results—

A genome-wide association study was conducted using 1830 cases from the United Kingdom, New Zealand, and Australia with infrarenal aorta diameter ≥30 mm or ruptured AAA and 5435 unscreened controls from the 1958 Birth Cohort and National Blood Service cohort from the Wellcome Trust Case Control Consortium. Eight suggestive associations with
P
<1×10
−4
were carried through to in silico replication in 1292 AAA cases and 30 503 controls. One single-nucleotide polymorphism associated with
P
<0.05 after Bonferroni correction in the in silico study underwent further replication (706 AAA cases and 1063 controls from the United Kingdom, 507 AAA cases and 199 controls from Denmark, and 885 AAA cases and 1000 controls from New Zealand). Low-density lipoprotein receptor (
LDLR
) rs6511720 A was significantly associated overall and in 3 of 5 individual replication studies. The full study showed an association that reached genome-wide significance (odds ratio, 0.76; 95% confidence interval, 0.70–0.83;
P
=2.08×10
−10
).

Conclusions—

LDLR rs6511720 is associated with AAA. This finding is consistent with established effects of this variant on coronary artery disease. Shared causal pathways with other cardiovascular diseases may present novel opportunities for preventative and therapeutic strategies for AAA.
Three-Dimensional Reconstruction of Cardiac Sarcoplasmic Reticulum Reveals a Continuous Network Linking Transverse-Tubules
Authors: Pinali Christian , Bennett Hayley , Davenport J. Bernard , Trafford Andrew W. , Kitmitto Ashraf
Published: September 2013

Rationale:

The organization of the transverse-tubular (t-t) system and relationship to the sarcoplasmic reticulum (SR) underpins cardiac excitation–contraction coupling. The architecture of the SR, and relationship with the t-ts, is not well characterized at the whole-cell level. Furthermore, little is known regarding changes to SR ultrastructure in heart failure.

Objective:

The aim of this study was to unravel interspecies differences and commonalities between the relationship of SR and t-t networks within cardiac myocytes, as well as the modifications that occur in heart failure, using a novel high-resolution 3-dimensional (3D) imaging technique.

Methods and Results:

Using serial block face imaging coupled with scanning electron microscopy and image analysis, we have generated 3D reconstructions of whole cardiomyocytes from sheep and rat left ventricle, revealing that the SR forms a continuous network linking t-ts throughout the cell in both species. In sheep, but not rat, the SR has an intimate relationship with the sarcolemma forming junctional domains. 3D reconstructions also reveal details of the sheep t-t system. Using a model of tachypacing-induced heart failure, we show that there are populations of swollen and collapsed t-ts, patches of SR tangling, and disorder with rearrangement of the mitochondria.

Conclusions:

We provide the first high-resolution 3D structure of the SR network showing that it forms a cell-wide communication pipeline facilitating Ca
2+
diffusion, buffering, and synchronicity. The distribution of the SR within the cell is related to interspecies differences in excitation–contraction coupling, and we report the first detailed analysis of SR remodeling as a result of heart failure.
MicroRNA-223 Antagonizes Angiogenesis by Targeting β1 Integrin and Preventing Growth Factor Signaling in Endothelial Cells
Authors: Shi Lei , Fisslthaler Beate , Zippel Nina , Frömel Timo , Hu Jiong , Elgheznawy Amro , Heide Heinrich , Popp Rüdiger , Fleming Ingrid
Published: September 2013

Rationale:

Endothelial cells in situ are largely quiescent, and their isolation and culture are associated with the switch to a proliferative phenotype.

Objective:

To identify antiangiogenic microRNAs expressed by native endothelial cells that are altered after isolation and culture, as well as the protein targets that regulate responses to growth factors.

Methods and Results:

Profiling studies revealed that miR-223 was highly expressed in freshly isolated human, murine, and porcine endothelial cells, but those levels decreased in culture. In primary cultures of endothelial cells, vascular endothelial cell growth factor and basic fibroblast growth factor further decreased miR-223 expression. The overexpression of precursor-miR-223 did not affect basal endothelial cell proliferation but abrogated vascular endothelial cell growth factor–induced and basic fibroblast growth factor–induced proliferation, as well as migration and sprouting. Inhibition of miR-223 in vivo using specific antagomirs potentiated postnatal retinal angiogenesis in wild-type mice, whereas recovery of perfusion after femoral artery ligation and endothelial sprouting from aortic rings from adult miR-223
−/y
animals were enhanced. MiR-223 overexpression had no effect on the growth factor–induced activation of ERK1/2 but inhibited the vascular endothelial cell growth factor–induced and basic fibroblast growth factor–induced phosphorylation of their receptors and activation of Akt. β1 integrin was identified as a target of miR-223 and its downregulation reproduced the defects in growth factor receptor phosphorylation and Akt signaling seen after miR-223 overexpression. Reintroduction of β1 integrin into miR-223–ovexpressing cells was sufficient to rescue growth factor signaling and angiogenesis.

Conclusions:

These results indicate that miR-223 is an antiangiogenic microRNA that prevents endothelial cell proliferation at least partly by targeting β1 integrin.
Temporal Differences in Out-of-Hospital Cardiac Arrest Incidence and Survival
Authors: Bagai Akshay , McNally Bryan F. , Al-Khatib Sana M. , Myers J. Brent , Kim Sunghee , Karlsson Lena , Torp-Pedersen Christian , Wissenberg Mads , van Diepen Sean , Fosbol Emil L. , Monk Lisa , Abella Benjamin S. , Granger Christopher B. , Jollis James G.
Published: September 2013

Background—

Understanding temporal differences in the incidence and outcomes of out-of-hospital cardiac arrest (OHCA) has important implications for developing preventative strategies and optimizing systems for OHCA care.

Methods and Results—

We studied 18 588 OHCAs of presumed cardiac origin in patients aged ≥18 years who received resuscitative efforts by emergency medical services (EMS) and were enrolled in the Cardiac Arrest Registry to Enhance Survival (CARES) from October 1, 2005, to December 31, 2010. We evaluated temporal variability in OHCA incidence and survival to hospital discharge. There was significant variability in the frequency of OHCA by hour of the day (
P
<0.001), day of the week (
P
<0.001), and month of the year (
P
<0.001), with the highest incidence occurring during the daytime, from Friday to Monday, in December. Survival to hospital discharge was lowest for OHCA that occurred overnight (from 11:01
pm
to 7
am
; 7.1%) versus daytime (7:01
am
to 3
pm
; 10.8%) or evening (3:01
pm
to 11
pm
; 11.3%;
P
<0.001) and during the winter (8.8%) versus spring (11.1%), summer (11.0%), or fall (10.0%;
P
<0.001). There was no difference in survival to hospital discharge between OHCAs that occurred on weekends and weekdays (9.5% versus 10.4%,
P
=0.06). After multivariable adjustment for age, sex, race, witness status, layperson resuscitation, first monitored cardiac rhythm, and emergency medical services response time, compared with daytime and spring, survival to hospital discharge remained lowest for OHCA that occurred overnight (odds ratio, 0.81; 95% confidence interval, 0.70–0.95;
P
=0.008) and during the winter (odds ratio, 0.81; 95% confidence interval, 0.70–0.94;
P
=0.006), respectively.

Conclusions—

There is significant temporal variability in the incidence of and survival after OHCA. The relative contribution of patient pathophysiology, likelihood of the OHCA being observed, and prehospital and hospital-based resuscitative factors deserves further exploration.
Association of Geographical Factors With Administration of Tissue Plasminogen Activator for Acute Ischemic Stroke
Authors: Kunisawa Susumu , Morishima Toshitaka , Ukawa Naoto , Ikai Hiroshi , Otsubo Tetsuya , Ishikawa Koichi B. , Yokota Chiaki , Minematsu Kazuo , Fushimi Kiyohide , Imanaka Yuichi
Published: September 2013

Background

Intravenous tissue plasminogen activator (
tPA
) is an effective treatment for acute ischemic stroke if administered within a few hours of stroke onset. Because of this time restriction,
tPA
administration remains infrequent. Ambulance use is an effective strategy for increasing
tPA
administration but may be influenced by geographical factors. The objectives of this study are to investigate the relationship between
tPA
administration and ambulance use and to examine how patient travel distance and population density affect
tPA
utilization.

Methods and Results

We analyzed administrative claims data from 114 194 acute ischemic stroke cases admitted to 603 hospitals between July 2010 and March 2012. Mixed‐effects logistic regression models of patients nested within hospitals with a random intercept were generated to analyze possible predictive factors (including patient characteristics, ambulance use, and driving time from home to hospital) of
tPA
administration for different population density categories to investigate differences in these factors in various regional backgrounds. Approximately 5.1% (5797/114 194) of patients received
tPA
. The composition of baseline characteristics varied among the population density categories, but adjustment for covariates resulted in all factors having similar associations with
tPA
administration in every category. The administration of
tPA
was associated with patient age and severity of stroke symptoms, but driving time showed no association. Ambulance use was significantly associated with
tPA
administration even after adjustment for covariates.

Conclusion

The association between ambulance use and
tPA
administration suggests the importance of calling an ambulance for suspected stroke. Promoting ambulance use for acute ischemic stroke patients may increase
tPA
use.
Isolating the Neural Mechanisms of Interference during Continuous Multisensory Dual-task Performance
Authors: Kasper Ryan W. , Cecotti Hubert , Touryan Jon , Eckstein Miguel P. , Giesbrecht Barry
Published: September 2013

The need to engage in multiple tasks simultaneously is often encountered in everyday experience, but coordinating between two or more tasks can lead to impaired performance. Typical investigations of multitasking impairments have focused on the performance of two tasks presented in close temporal proximity on discrete trials; however, such paradigms do not match well with the continuous performance situations more typically encountered outside the laboratory. As a result, the stages of information processing that are affected during multisensory continuous dual tasks and how these changes in processing relate to behavior remain unclear. To address these issues, participants were presented simultaneous rapid visual and auditory stimulus sequences under three conditions: attend visual only, attend auditory only, and dual attention (attend both visual and auditory). Performance, measured in terms of response time and perceptual sensitivity (d′), revealed dual-task impairments only in the auditory task. Neural activity, measured by the ERP technique, revealed that both early stage sensory processing and later cognitive processing of the auditory task were affected by dual-task performance, but similar stages of processing of the visual task were not. Critically, individual differences in neural activity at both early and late stages of information processing accurately rank-ordered individuals based on the observed difference in behavioral performance between the single and dual attention conditions. These results reveal relationships between behavioral performance and the neural correlates of both early and late stage information processing that provide key insights into the complex interplay between the brain and behavior when multiple tasks are performed continuously.
“Change Deafness” Arising from Inter-feature Masking within a Single Auditory Object
Authors: Barascud Nicolas , Griffiths Timothy D. , McAlpine David , Chait Maria
Published: September 2013

Our ability to detect prominent changes in complex acoustic scenes depends not only on the ear's sensitivity but also on the capacity of the brain to process competing incoming information. Here, employing a combination of psychophysics and magnetoencephalography (MEG), we investigate listeners' sensitivity in situations when two features belonging to the same auditory object change in close succession. The auditory object under investigation is a sequence of tone pips characterized by a regularly repeating frequency pattern. Signals consisted of an initial, regularly alternating sequence of three short (60 msec) pure tone pips (in the form ABCABC…) followed by a long pure tone with a frequency that is either expected based on the on-going regular pattern (“LONG expected”—i.e., “LONG-expected”) or constitutes a pattern violation (“LONG-unexpected”). The change in LONG-expected is manifest as a change in duration (when the long pure tone exceeds the established duration of a tone pip), whereas the change in LONG-unexpected is manifest as a change in both the frequency pattern and a change in the duration. Our results reveal a form of “change deafness,” in that although changes in both the frequency pattern and the expected duration appear to be processed effectively by the auditory system—cortical signatures of both changes are evident in the MEG data—listeners often fail to detect changes in the frequency pattern when that change is closely followed by a change in duration. By systematically manipulating the properties of the changing features and measuring behavioral and MEG responses, we demonstrate that feature changes within the same auditory object, which occur close together in time, appear to compete for perceptual resources.
TMS over M1 Reveals Expression and Selective Suppression of Conflicting Action Impulses
Authors: van Campen A. Dilene , Keuken Max C. , van den Wildenberg Wery P. M. , Ridderinkhof K. Richard
Published: September 2013

Goal-directed action control comes into play when selecting between competing action alternatives. Response capture reflects the susceptibility of the motor system to incitement by task-irrelevant action impulses; the subsequent selective suppression of incorrect action impulses aims to counteract response capture and facilitate the desired response. The goal of this experiment was to clarify physiological mechanisms of response capture and suppression of action impulses during conflict at the level of the motor system. We administered single-pulse TMS at various intervals preceding speeded choice responses. The correct response side was designated by stimulus color, whereas stimulus location (which could match or conflict with response side) was to be ignored. TMS pulses triggered motor evoked potential and silent period, providing sensitive indices of cortico-spinal excitation and inhibition. Motor evoked potential data showed the typical progressive increase in cortico-spinal motor excitability leading up to the imminent (correct) response, which started earlier on nonconflict than on conflict trials. On conflict trials, the irrelevant stimulus location captured the incorrect response, as expressed by an early and transient rise in excitability. Silent period data showed that, already early during the response process, inhibition of the incorrect response was stronger for conflict than for nonconflict trials. Furthermore, inhibition decreased over time for nonconflict trials facilitating the imminent correct response while maintaining higher levels of inhibition on conflict trials. In conclusion, dynamic patterns of cortico-spinal excitability provide unique physiological evidence for the expression and selective suppression of action impulses captured by competing action alternatives.
Task- and Experience-dependent Cortical Selectivity to Features Informative for Categorization
Authors: van der Linden Marieke , Wegman Joost , Fernández Guillén
Published: September 2013

In this study, we bridge the gap between monkey electrophysiological recordings that showed selective responses to informative features and human fMRI data that demonstrated increased and selective responses to trained objects. Human participants trained with computer-generated fish stimuli. For each participant, two features of the fish were informative for category membership and two features were uninformative. After training, participants showed higher perceptual sensitivity to the informative dimensions. An fMRI adaptation paradigm revealed that during categorization the right inferior frontal gyrus and occipitotemporal cortex were selectively responsive to the informative features. These selective cortical responses were experience dependent; they were not present for the entire trained object, but specific for those features that were informative for categorization. Responses in the inferior frontal gyrus showed category selectivity. Moreover, selectivity to the informative features correlated with performance on the categorization task during scanning. This all suggests that the frontal cortex is involved in actively categorizing objects and that it uses informative features to do so while ignoring those features that do not contribute category information. Occipitotemporal cortex also showed selectivity to the informative features during the categorization task. Interestingly, this area showed a positive correlation of performance during training and selectivity to the informative features and a negative correlation with selectivity to the uninformative features. This indicates that training enhanced sensitivity to trained items and decreased sensitivity to uninformative features. The absence of sensitivity for informative features during a color change detection task indicates that there is a strong component of task-related processing of these features.
Trade-off between Capacity and Precision in Visuospatial Working Memory
Authors: Roggeman Chantal , Klingberg Torkel , Feenstra Heleen E. M. , Compte Albert , Almeida Rita
Published: September 2013

Limitations in the performance of working memory (WM) tasks have been characterized in terms of the number of items retained (capacity) and in terms of the precision with which the information is retained. The neural mechanisms behind these limitations are still unclear. Here we used a biological constrained computational model to study the capacity and precision of visuospatial WM. The model consists of two connected networks of spiking neurons. One network is responsible for storage of information. The other provides a nonselective excitatory input to the storage network. Simulations showed that this excitation boost could temporarily increase storage capacity but also predicted that this would be associated with a decrease in precision of the memory. This prediction was subsequently tested in a behavioral (38 participants) and fMRI (22 participants) experiment. The behavioral results confirmed the trade-off effect, and the fMRI results suggest that a frontal region might be engaged in the trial-by-trial control of WM performance. The average effects were small, but individuals differed in the amount of trade-off, and these differences correlated with the frontal activation. These results support a two-module model of WM where performance is determined both by storage capacity and by top–down influence, which can vary on a trial-by-trial basis, affecting both the capacity and precision of WM.
Neural Network Configuration and Efficiency Underlies Individual Differences in Spatial Orientation Ability
Authors: Arnold Aiden E. G. F. , Protzner Andrea B. , Bray Signe , Levy Richard M. , Iaria Giuseppe
Published: September 2013

Spatial orientation is a complex cognitive process requiring the integration of information processed in a distributed system of brain regions. Current models on the neural basis of spatial orientation are based primarily on the functional role of single brain regions, with limited understanding of how interaction among these brain regions relates to behavior. In this study, we investigated two sources of variability in the neural networks that support spatial orientation—network configuration and efficiency—and assessed whether variability in these topological properties relates to individual differences in orientation accuracy. Participants with higher accuracy were shown to express greater activity in the right supramarginal gyrus, the right precentral cortex, and the left hippocampus, over and above a core network engaged by the whole group. Additionally, high-performing individuals had increased levels of global efficiency within a resting-state network composed of brain regions engaged during orientation and increased levels of node centrality in the right supramarginal gyrus, the right primary motor cortex, and the left hippocampus. These results indicate that individual differences in the configuration of task-related networks and their efficiency measured at rest relate to the ability to spatially orient. Our findings advance systems neuroscience models of orientation and navigation by providing insight into the role of functional integration in shaping orientation behavior.
Dynamical Regimes in Neural Network Models of Matching Behavior
Authors: Iigaya Kiyohito , Fusi Stefano
Published: September 2013

The matching law constitutes a quantitative description of choice behavior that is often observed in foraging tasks. According to the matching law, organisms distribute their behavior across available response alternatives in the same proportion that reinforcers are distributed across those alternatives. Recently a few biophysically plausible neural network models have been proposed to explain the matching behavior observed in the experiments. Here we study systematically the learning dynamics of these networks while performing a matching task on the concurrent variable interval (VI) schedule. We found that the model neural network can operate in one of three qualitatively different regimes depending on the parameters that characterize the synaptic dynamics and the reward schedule: (1) a matching behavior regime, in which the probability of choosing an option is roughly proportional to the baiting fractional probability of that option; (2) a perseverative regime, in which the network tends to make always the same decision; and (3) a tristable regime, in which the network can either perseverate or choose the two targets randomly approximately with the same probability. Different parameters of the synaptic dynamics lead to different types of deviations from the matching law, some of which have been observed experimentally. We show that the performance of the network depends on the number of stable states of each synapse and that bistable synapses perform close to optimal when the proper learning rate is chosen. Because our model provides a link between synaptic dynamics and qualitatively different behaviors, this work provides us with insight into the effects of neuromodulators on adaptive behaviors and psychiatric disorders.
New sources of taxonomic information for earthstars (Geastrum, Geastraceae, Basidiomycota): phenoloxidases and rhizomorph crystals
Authors: Zamora Juan Carlos , Calonge Francisco De Diego , Martín María Paz
Published: September 2013

The taxonomic utility of two characters not previously used for identification of Geastrum species is evaluated. First, macrochemical spot tests with chemicals detecting phenoloxidase enzymatic activity (1-naphthol, guaiac gum, and syringaldazine), are performed. In addition, the usefulness of the crystalline deposits from the rhizomorphs, formed by calcium oxalate as monohydrate or whewellite, and dihydrate or weddellite, was evaluated. These features provide valuable data to distinguish some taxa difficult to separate using traditional morphology, such as G. lageniforme, G. saccatum, and G. triplex.
A Molecular Systematic Analysis of Passiflora ovalis and Passiflora contracta (Passifloraceae)
Authors: Cazé Ana Luiza R , Mäder Geraldo , Bonatto Sandro L , Freitas Loreta B
Published: September 2013

Passiflora ovalis and P. contracta are species restricted to the Atlantic Rainforest (Mata Atlântica) of Brazil and were separated into two distinct taxonomic units based on different morphological traits, as inflorescence structure and indument, being the populations located between 7–19°S referred to P. contracta, while those found around 23°S belong to P. ovalis. Recently the species were grouped together under the specific name P. ovalis. The objective of this work was to understand the taxonomy of these species based in a Bayesian phylogenetic analysis using a combination of molecular markers from plastidial and nuclear genomes. The results confirmed the existence of two distinct species supported by full posterior probability values. We consequently propose accepting the two-species, which also have been validated both by morphologic differences and distinct geographic distribution.
Cognición social contexto-dependiente y redes frontotemporo-insulares
Authors: Sedeño Lucas , Moya Álvaro , Baker Phil , Ibáñez Agustín
Published: September 2013

La cognición social es dependiente de la información sutil e implícita presente en el contexto durante interacciones sociales. Presentamos y describimos un modelo anátomo-funcional, denominado SCNM (del inglés Social Context Network Model), que pretende explicar cómo se procesa el contexto en situaciones sociales. Además, muestra cómo diferentes alteraciones de sus redes subyacen a los déficits en cognición social de pacientes con demencia frontotemporal, lesiones fronto-insulares, enfermedades del neurodesarrollo y otros cuadros neuropsiquiátricos. Se presentan estudios precursores basados en el SCNM y se los contrapone al enfoque descontextualizado de abordajes clásicos en cognición social. El SCNM es un modelo teórico que provee un conjunto de hipótesis que permiten examinar y comprender mejor los procesos subyacentes a los déficits en cognición social. A nivel clínico, propone el desarrollo de herramientas más ecológicas que las tradicionales, que permitirían una mejor detección y caracterización de distintas enfermedades neurológicas y psiquiátricas, como así también la implementación de ambientes en rehabilitación que imiten mejor las situaciones de la vida cotidiana.
Adaptación española de la dimensión conductual del Displaced Aggression Questionnaire. Análisis de validez con medidas de ira y agresión genéricas y en la conducción
Authors: Herrero-Fernández David
Published: September 2013

El presente estudio examinó el ajuste psicométrico de la dimensión de conducta agresiva desplazada del Displaced Aggression Questionnaire (Denson, Pedersen y Miller, 2006), una escala de 10 ítems que mide la frecuencia de agresión desplazada, en una muestra española compuesta por 285 participantes. El análisis factorial confirmatorio mostró el ajuste satisfactorio en un único factor, al igual que una elevada consistencia interna (α =.93). Para el estudio de validez se utilizaron medidas de ira y agresión genéricas y en el ámbito concreto de la conducción. Se observó una elevada validez convergente y discriminante, tanto por modo de comportamiento (correlacionando más fuertemente con la agresión desplazada al volante que con el resto de formas en este contexto) como por contexto (correlacionando más fuertemente con las medidas generales que con las relativas a la conducción). Los resultados sugieren que se trata de una herramienta recomendable para la medición de este constructo.
La señal electrodérmica mediante Sociograph: metodología para medir la actividad grupal
Authors: Aiger Montserrat , Palacín María , Cornejo José-Manuel
Published: September 2013

Se presenta esta metodología desde la perspectiva de la Neurociencia Social, mediante el uso de la actividad electrodérmica (EDA) como marcador somático para medir la conducta grupal. Sociograph mide el comportamiento atencional (EDLg) y emocional (EDRg) durante la actividad grupal. Sociograph permite realizar en tiempo real y continuo el registro psicofisológico de la actividad grupal de la interacción, interdependencia e intercambio grupal. La señal grupal (EDAg) se da en secuencias de “Módulos de actividad' en medidas continuas temporales.

Se presenta el ejemplo donde se aplica la metodología en la actividad grupal denominada “Tangram” a 18 grupos con 5 personas por grupo. Los resultados ilustran la existencia de un patrón de activación psicofisiológico propio de la actividad grupal y la metodología utilizada verifica que el grupo reacciona de manera diferente a contextos estimulares distintos. La EDAg resulta un buen indicador somático para evaluar el comportamiento psicosocial, y resulta apropiado para el estudio del comportamiento grupal (intragrupal).
Memoria de trabajo y cambio en la atribución de hostilidad en situaciones sociales accidentales en pacientes con esquizofrenia paranoide
Authors: Hernández José-Vicente , Ricarte Jorge-Javier , Ros Laura , Latorre José-Miguel
Published: September 2013

La falta de comprensión de la conducta y los pensamientos de los otros puede ser un factor explicativo del deterioro de la cognición social en la esquizofrenia paranoide. El entrenamiento en cognición social disminuye la atribución de hostilidad y agresividad en estos pacientes. Sin embargo, la evaluación del papel de variables neu-rológicas en los efectos de esos tratamientos es poco frecuente. Este estudio evalúa el impacto de un entrenamiento en cognición social sobre la atribución de hostilidad y agresividad en diversas situaciones negativas de tipo accidental covariando variables de memoria de trabajo y fluidez verbal. La terapia implicaba el análisis de situaciones donde se utilizaron mentiras piadosas o expresiones sarcásticas. Los pacientes disminuyeron significativamente las atribuciones de hostilidad. Sin embargo, al introducir en los análisis como covariadas las variables de memoria de trabajo y fluidez verbal, los efectos del tratamiento sobre la hostilidad desaparecieron. Estos resultados apoyan la relevancia de controlar variables como la memoria de trabajo en el estudio de los procedimientos para la mejora de la cognición social en pacientes con esquizofrenia paranoide.
Cognición social en el síndrome de Williams
Authors: Campos Ruth , Martínez-Castilla Pastora , Sotillo María
Published: September 2013

Frente a una concepción neuropsicológica estática, que entiende la arquitectura cognitiva como un conjunto de sistemas específicos de funcionamiento independiente de origen innato, este trabajo asume una perspectiva neu-roconstructivista, que contempla la especialización y localización progresiva de las funciones, enfatizando la necesidad de atender desde el desarrollo a los distintos niveles de explicación del funcionamiento psicológico, y en el que la relación con las bases genéticas o neurobiológicas también va a estar mediada por un ambiente dinámico. Desde estos argumentos se revisa la evidencia experimental sobre el funcionamiento de las personas con síndrome de Williams (SW) en distintos aspectos vinculados con la cognición social (competencias mentalistas, procesamiento de rostros y lenguaje). Se concluye en contra de la propuesta de que el perfil psicológico de las personas con SW evidencia la existencia de un módulo para la cognición social, se sugiere la necesidad de atender a las trayectorias de desarrollo y se plantean algunas implicaciones del modelo para la intervención psicológica.
Metacognitive confidence: A neuroscience approach
Authors: Luttrell Andrew , Briñol Pablo , Petty Richard E. , Cunningham William , Díaz Darío
Published: September 2013

Metacognition refers to thinking about our own thinking and implies a distinction between primary and secondary cognition. This article reviews how neuroscience has dealt with this distinction between first and second-order cognition, with special focus on meta-cognitive confidence. Meta-cognitive confidence is important because it affects whether people use their primary cognitions in guiding judgments and behaviors. The research described in this review is organized around the type of primary thoughts for which people have confidence, including judgments about memory, choices, and evaluative judgments. Along with other areas, prefrontal cortex and parietal regions have been consistently associated with judgments of meta-cognitive confidence in these three domains. Although metacognitive confidence might be associated with particular brain activity in most of the studies reviewed, confidence often seems to be confounded with other potentially important dimensions, such as effort and ease. Given that people tend to be less certain in tasks that are more difficult, more research is needed to examine the brain activity specifically linked to confidence.
Cognición social sobre el yo y sobre los otros: una perspectiva neurocientífica
Authors: Díaz Darío
Published: September 2013

En los últimos años ha crecido de manera exponencial el interés en estudiar las estructuras cerebrales implicadas en la cognición social, su conectividad anatómica y funcional. En su estudio nos encontraremos con una primera dificultad: la mayor parte de los procesos vinculados a la cognición social son procesos de alto nivel (por ejemplo, relacionados con el auto-concepto) que suelen reflejar las propiedades emergentes de procesos de nivel más básico (como relacionados con la memoria). El segundo gran problema tiene que ver con las limitaciones teóricas e instrumentales (e.g. técnicas de neuroimagen) que han conducido a un cierto paradigma de “cognición social aislada” vinculada con experimentos no realizados en situaciones de interacción real. Partiendo de ambos problemas, en este artículo pretendemos revisar de manera crítica los resultados más importantes que se han encontrado sobre las bases biológicas de la cognición social relacionada con los otros y con el yo.
Men and women facing objectification: The effects of media models on well-being, self-esteem and ambivalent sexism
Authors: Rollero Chiara
Published: September 2013

Literature on objectification has largely shown the relationship between viewing objectified media models and women's body dissatisfaction and drive for thinness. The purpose of the present study was to extend past research by examining the effects of objectified media images—considering both male and female models—on psychological well-being, self-esteem, and endorsement of sexist attitudes. 166 undergraduates (51.8% males) participated in the study. Results showed that objectification of men decreases men's well-being, whereas objectification of women not only decreases women's well-being, but also their attractiveness and social self-esteem. Furthermore, objectification of women affects men's endorsement of sexist attitudes, increasing hostility toward women and decreasing hostility toward men. Implications are discussed.
Variability Common to First Leaf Dates and Snowpack in the Western Conterminous United States
Authors: McCabe Gregory J. , Betancourt Julio L. , Pederson Gregory T. , Schwartz Mark D.
Published: September 2013

Singular value decomposition is used to identify the common variability in first leaf dates (FLDs) and 1 April snow water equivalent (SWE) for the western United States during the period 1900–2012. Results indicate two modes of joint variability that explain 57% of the variability in FLD and 69% of the variability in SWE. The first mode of joint variability is related to widespread late winter–spring warming or cooling across the entire west. The second mode can be described as a north–south dipole in temperature for FLD, as well as in cool season temperature and precipitation for SWE, that is closely correlated to the El Niño–Southern Oscillation. Additionally, both modes of variability indicate a relation with the Pacific–North American atmospheric pattern. These results indicate that there is a substantial amount of common variance in FLD and SWE that is related to large-scale modes of climate variability.
Mechanisms of Global-Mean Steric Sea Level Change
Authors: Piecuch Christopher G. , Ponte Rui M.
Published: September 2013

Global-mean sea level change partly reflects volumetric expansion of the oceans because of density change, otherwise known as global-mean steric sea level change. Owing to nonlinearities in the equation of state of seawater, the nature of processes contributing to recent observed global-mean steric sea level changes has not been well understood. Using a data-constrained ocean state estimate, global-mean steric sea level change over 1993–2003 is revisited, and contributions from ocean transports and surface exchanges are quantified using closed potential temperature and salinity budgets. Analyses demonstrate that estimated decadal global-mean steric sea level change results mainly from a slight, time-mean imbalance between atmospheric forcing and ocean transports over the integration period: surface heat and freshwater exchanges produce a trend in global-mean steric sea level that is mainly offset by the redistribution of potential temperature and salinity through small-scale diffusion and large-scale advection. A set of numerical experiments demonstrates that global-mean steric sea level changes simulated by ocean general circulation models are sensitive to the regional distribution of ocean heat and freshwater content changes.
The performances of the Cockcroft-Gault, Modification of Diet in Renal Disease Study and Chronic Kidney Disease Epidemiology Collaboration equations in predicting gentamicin clearance
Authors: Chin PKL , Florkowski CM , Begg EJ
Published: September 2013

Background

It is unclear which renal function equation, employing an isotope dilution mass spectrometry (IDMS)-aligned creatinine assay, best predicts gentamicin clearance.

Methods

The performances of the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) Study and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations for predicting gentamicin clearances were assessed retrospectively in 240 patients treated with gentamicin during 2011–2012, when the local creatinine assay was IDMS-aligned. Comparisons were based on the percentage within 30% of gentamicin clearance ( P30) and the root-mean-square error (RMSE) of each equation. Gentamicin clearance was calculated from plasma concentrations using a one-compartment model.

Results

The Cockcroft-Gault equation and the CKD-EPI equation corrected for individual body surface area (BSA) were associated with the highest P30 (69% and 67%, respectively) and lowest RMSE (39 and 36 mL/min, respectively) in the 240 patients. Correction for individual BSA improved the performances of the MDRD Study and CKD-EPI equations in patients with body mass indices <18.5 or ≥30 kg/m2. The equations systematically underestimated gentamicin clearance as gentamicin clearance increased, with performance being inferior with gentamicin clearance ≥90 versus <90 mL/min.

Conclusions

The CKD-EPI equation corrected for individual BSA, and the Cockcroft-Gault equation, provided the best estimates of gentamicin clearance. The CKD-EPI and MDRD Study equations should be corrected for individual BSA at the extremes of body size, if used for guiding gentamicin therapy. The performances of the equations were inferior in patients with higher values of gentamicin clearance.
Pseudohyperkalaemia in leukaemic patients: the effect of test tube type and form of transport to the laboratory
Authors: Dastych Milan , Čermáková Zdenka
Published: September 2013

Background

The present study was aimed at determining the effect of the tube type used for primary sample collection and the manner of transport prior to assessment (either manual or by pneumatic tube) on the degree of pseudohyperkalaemia in leukaemic patients.

Methods

Blood from six leukaemic patients was collected into seven primary sample tubes (Monovette®, Sarstedt): sample A, heparinized blood gas syringe (potassium reference value); sample B, plasma Li-heparin without separator gel; sample C, plasma Li-heparin with separator gel; and sample D, serum with separator gel. The primary sample tubes designated B, C and D were transported to the laboratory manually. Duplicates of the same sample tubes, BPT, CPT and DPT, were sent to the laboratory by pneumatic tube.

Results

In patients with chronic lymphocytic leukaemia (CLL), there was no increase in the concentration of potassium in samples B, C and D when compared to the reference value. Transport of the samples by pneumatic tube led to a pronounced increase in potassium concentration in samples BPT and CPT, whereas there was no increase in sample DPT when compared to the reference value. In the patient with chronic myeloid leukaemia (CML), an increase in potassium concentration occurred in sample D and in samples BPT, CPT and DPT. A similar finding was observed in the patient with acute lymphocytic leukaemia (ALL), furthermore with an extremely high concentration of potassium in samples C and CPT.

Conclusions

Manual transport of non-coagulable blood (plasma Li-heparin without separator gel) to the laboratory results in the least possible artificial increase in potassium concentration in the sample.
Machiavelli on Dante on language
Authors: Verdicchio Massimo
Published: September 2013

Machiavelli’s ‘Discorso o dialogo intorno alla nostra lingua’ (c. 1515) is not one of the major treatises on the ‘questione della lingua’. Critics even doubt that the author is Machiavelli since the work contains injurious attacks on Dante that are believed unlikely from someone who wrote highly of him in his other works. Machiavelli scholars have tried to justify his position toward Dante in the treatise as an attempt to make a case for Italian unity. The work has also been read from the perspective of the received ideas on Dante in the Renaissance, which are echoed in Machiavelli’s slanderous criticism. In my article, I would like to approach the treatise from Dante’s point of view to weigh the extent to which Machiavelli’s claims can be said to be valid and justified. Although Machiavelli seems to have had a limited knowledge of Dante’s linguistic treatise, De vulgari eloquentia, he certainly knew the Inferno well enough to parody it in his L’Asino and to take Dante to task for his attitude toward the Florentine language, the Florentines and Florence. My aim is to show that Machiavelli’s unstated objective in the treatise, and the reason for his critique of Dante, is to ingratiate himself with the Medici and be accepted into their service.