bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observational Evidences of Vocal Learning in Southern Elephant Seals: a Longitudinal Study
Authors: Sanvito Simona , Galimberti Filippo , Miller Edward H. 
Published: February 2007

AbstractVocal learning in mammals is sparsely documented, and there are few reports of vocal learning by wild mammals. In particular, no information based on longitudinal data for identified individuals exists, even for well‐studied highly social species in which vocal communication is an important aspect of social life. We present such information for the southern elephant seal (Mirounga leonina). We studied a small breeding population in the Falkland Islands over 8 yr (1995–2002). We recorded approx. 2400 agonistic vocalizations from approx. 285 different males, including many recorded over more than one breeding season (55 males were recorded for >2 yr and 29 were recorded throughout vocal development). Vocalizations are a key element of male agonistic behaviour in this species, the world's most polygynous vertebrate. For male agonistic vocalizations, we show that: (1) a limited number of discrete vocal types exists; (2) proportions of vocal types change over time; (3) observed trends of increase or decrease of vocal types are well explained by a process of vocal learning, in which younger peripheral males imitate vocal types of older more successful breeders.
Post‐copulatory Mounting Behavior of the West Indian Sweetpotato Weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae)
Authors: Sato Yukie , Kohama Tsuguo 
Published: February 2007

AbstractPost‐copulatory associations between males and females have been found in a variety of insects and are often described as mate guarding. Males of the West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire) mount the female's back after copulation. Two hypotheses have been advanced to explain this behavior: mate guarding to prevent future copulations by rivals (hypothesis 1), and mate guarding to gain additional copulations (hypothesis 2). We conducted three experiments to test predictions from these hypotheses. Our results disproved hypothesis 1 because the duration of the post‐copulatory association was very brief in comparison with the length of the refractory phase all females showed after copulation. When we prevented females from resisting copulations during the post‐copulatory mounted phase males copulated again, while under normal conditions, a second copulation was never observed. This result may indicate the presence of a sexual conflict over mating. However, we propose an alternative interpretation of the result, namely that after mating, males test whether the copulation has successfully reduced female receptivity by attempting to remate. If females resist the mating, males leave.
All that Glisters is not Gold: Sensory Bias, Sexual Conflict and Nuptial Feeding in Insects and Spiders
Authors: Vahed Karim 
Published: February 2007

AbstractIt is becoming increasingly clear that the evolutionary interests of the sexes are often in conflict when it comes to mating. Sexual encounters involving nuptial gifts, however, have often been viewed as prime examples of sexual co‐operation, rather than conflict. In this review, I explore the proposition that nuptial gifts act as sensory traps: by exploiting the female's gustatory responses, the male may be able to entice females to accept superfluous matings and/or transfer greater volumes of ejaculate than are in the female's reproductive interests. Evidence suggests that the females’ sensory biases may have played an important role in shaping gift characteristics in at least four different systems, although relatively few forms of nuptial feeding have so far been examined from this perspective. I argue that gift composition is more likely to be tailored to increasing the attractiveness of the gift to the female and/or maximizing gift handling time than to suit the female's nutritional needs and that the fecundity‐enhancing benefits of nuptial gifts are often questionable and have been over‐stated in the literature. Fertilization biases associated with the female's attraction to the nuptial gift, however, could lead to in‐direct benefits for the female. On the other hand, nuptial feeding may also lead to significant costs to the female. Evidence suggests that some types of gift entice the female to mate, but it is not clear whether the resultant degree of polyandry is higher than optimal for the female. In other cases, evidence suggests that the gift enables the male to overcome the resistance of the female to accepting an extra large ejaculate and that large ejaculates are associated with longer post‐mating sexual refractory periods in the female. This could represent a cost to the female by delaying or preventing her from receiving the genetic benefits of polyandry. At present, it is not clear, however, whether such costs outweigh the potential benefits of nuptial feeding for the female.
On Optimal Commodity Taxes When Consumption Is Time Consuming
Authors: GAHVARI FIROUZ 
Published: February 2007

AbstractThis paper studies the problem of optimal taxation of commodities when consumption is a time‐consuming activity. This is done under two distinct preference separability assumptions: between goods and labor supply, and between goods and leisure. It argues that with the labor separability, the traditional uniform taxation results of optimal tax theory continue to hold. With leisure separability, on the other hand, consumption time is a major ingredient of optimal tax rates. However, the relationship between consumption time and optimal tax rates depends crucially on the representation of the economy. In representative consumer economies, time differences determine the pattern of optimal tax rates so that goods whose consumption take more time are subjected to higher tax rates. When individuals have different earning abilities, redistributive, incentive, and efficiency considerations also come into play resulting in a complex relationship. The paper derives formulas for optimal commodity taxes in this case on the basis of three different tax structures: linear commodity taxes in combination with linear and nonlinear income taxes, and nonlinear commodity taxes in combination with nonlinear income taxes.
Asymmetric Equilibria in a Model with Costly Voting
Authors: DE SINOPOLI FRANCESCO , IANNANTUONI GIOVANNA 
Published: February 2007

AbstractMost of the voting models limit their analysis to the investigation of symmetric equilibria where “similar” voters make “similar” voting decisions. In this paper we examine the validity of this restriction in a model with costly plurality voting. We first show that in any pure strategy equilibrium every two individuals who have the same preferences and participate in elections, would vote for the same candidate. However, this result does not hold for mixed strategies equilibria.
The Simple Economics of Bunching: Optimal Taxation with Quasi‐Linear Preferences
Authors: BOONE JAN , BOVENBERG LANS 
Published: February 2007

AbstractThis paper models unemployment as a binding nonnegativity constraint on hours worked in an optimal income tax problem with quasi‐linear preferences. We show that bunching of workers resulting from this binding constraint provides a more convincing description of the bottom of the labor market than bunching due to violation of the second‐order condition for individual optimization. Although a binding nonnegativity constraint destroys the closed form solution of optimal marginal tax rates, the optimal tax problem can be characterized in a two‐dimensional diagram in which comparative statics can be performed in straightforward fashion.
AFTERWORDS: AN INTRODUCTION TO ARTHUR DANTO'S PHILOSOPHIES OF HISTORY AND ART*
Authors: GOEHR LYDIA 
Published: February 2007

ABSTRACTThis essay is written as an introductory essay to celebrate the third edition of Arthur Danto's Analytical Philosophy of History, first printed in 1965. It raises questions about what it means to write an introduction and whether it is possible to write an introduction‐given Danto's own philosophical theses on history, the essay pays special attention to the connections between Danto's philosophy of history, philosophy of art, and the other areas of his philosophy that he regards to be all of a piece. It considers the nature of analytical philosophy and its heyday in America in the postwar period, when, to some degree, it was used as an antidote to an ideology of history that had perverted some of the most influential claims in a philosophy of history developed in Germany (mostly by Hegel) around 1800.
INTELLECTUAL HISTORY, INCONCEIVABILITY, AND METHODOLOGICAL HOLISM1
Authors: MITROVIĆ BRANKO 
Published: February 2007

ABSTRACTThe debate between individualism and holism in the philosophy of history pertains to the nature of the entities relied on in historical explanations. The question is whether explanations of historical items (for example, events, actions, artifacts) require the assumption that the collective historical entities (for example, civilizations, cultures, and so on) used in these explanations are (sometimes) conceived of as irreducible to the actions, thoughts, and beliefs of individual human beings. In this paper I analyze two methodological problems that holist explanations face in the writing of intellectual history. The first problem derives from the fact that holist explanations in intellectual history have to rely on the claim that certain beliefs were inconceivable to some individuals because they were members of specific collectives, whereas it is unclear how historical research can justify such claims when made from the holist position. The second problem pertains to the difficulties the holist position faces when it has to account for the novel properties of artifacts studied by intellectual history.
Ultrastructural localization of glycodelin oligosaccharides Le‐x and Le‐y in human seminal vesicles by immunogold staining
Authors: Piludu M. , Cossu M. , De Lisa A. , Piras M. , Lantini M. S. 
Published: February 2007

AbstractHisto‐blood group antigens Le‐x and Le‐y are oligosaccharidic terminals that characterize many glycoproteins in the human tissues. In seminal plasma, they are expressed as part of the so‐called glycodelin S, which is suggested to regulate sperm capacitation/decapacitation. It has recently been demonstrated that the core protein of glycodelin S is secreted by seminal vesicles. Here we show that epithelial cells of human seminal vesicles also release the Le‐x and Le‐y antigens. The presence of these substances in secretory material was revealed by means of an immunogold staining method in normal surgical samples. The results suggest that glycodelin S is secreted by seminal vesicles in its finished glycosylated form. Moreover, antigen reactivity was also revealed associated with plasma membranes.
Porosity of human mandibular condylar bone
Authors: Renders G. A. P. , Mulder L. , Van Ruijven L. J. , Van Eijden T. M. G. J. 
Published: February 2007

AbstractQuantification of porosity and degree of mineralization of bone facilitates a better understanding of the possible effects of adaptive bone remodelling and the possible consequences for its mechanical properties. The present study set out first to give a three‐dimensional description of the cortical canalicular network in the human mandibular condyle, in order to obtain more information about the principal directions of stresses and strains during loading. Our second aim was to determine whether the amount of remodelling was larger in the trabecular bone than in cortical bone of the condyle and to establish whether the variation in the amount of remodelling was related to the surface area of the cortical canals and trabeculae. We hypothesized that there were differences in porosity and orientation of cortical canals between various cortical regions. In addition, as greater cortical and trabecular porosities are likely to coincide with a greater surface area of cortical canals and trabeculae available for osteoblastic and osteoclastic activity, we hypothesized that this surface area would be inversely proportional to the degree of mineralization of cortical and trabecular bone, respectively. Micro‐computed tomography was used to quantify porosity and mineralization in cortical and trabecular bone of ten human mandibular condyles. The cortical canals in the subchondral cortex of the condyle were orientated in the mediolateral direction, and in the anterior and posterior cortex in the superoinferior direction. Cortical porosity (average 3.5%) did not differ significantly between the cortical regions. It correlated significantly with the diameter and number of cortical canals, but not with cortical degree of mineralization. In trabecular bone (average porosity 79.3%) there was a significant negative correlation between surface area of the trabeculae and degree of mineralization; such a correlation was not found between the surface area of the cortical canals and the degree of mineralization of cortical bone. No relationship between trabecular and cortical porosity, nor between trabecular degree of mineralization and cortical degree of mineralization was found, suggesting that adaptive remodelling is independent and different between trabecular and cortical bone. We conclude (1) that the principal directions of stresses and strains are presumably directed mediolaterally in the subchondral cortex and superoinferiorly in the anterior and posterior cortex, (2) that the amount of remodelling is larger in the trabecular than in the cortical bone of the mandibular condyle; in trabecular bone variation in the amount of remodelling is related to the available surface area of the trabeculae.
Activation of stress‐related hypothalamic neuropeptide gene expression during morphine withdrawal
Authors: Nunez Cristina , Földes Anna , Laorden M. Luisa , Milanes M. Victoria , Kovács Krisztina J. 
Published: February 2007

AbstractMorphine withdrawal results in serious affective and somatic symptoms including activation of the hypothalamo–pituitary–adrenocortical (HPA) axis. To reveal secretory, activational and transcriptional changes in the hypothalamus of morphine‐dependent rats during naloxone precipitated opioid withdrawal, we measured corticosterone secretion, c‐Fos induction and heteronuclear (hn)RNA levels of corticotropin‐releasing hormone (CRH) and arginine vasopressin (AVP) in naïve and morphine dependent animals injected with saline or 5 mg/kg naloxone. Naloxone precipitated morphine withdrawal resulted in a significant increase in corticosterone secretion and induction of neuronal activation in the hypothalamic paraventricular nucleus (PVH) 2 h after challenge. Using probes complementary to intronic sequences of genes encoding neuropeptides in parvocellular neurosecretory neurons of the PVH, we found robust increases in CRH and AVP hnRNAs in morphine dependent rats during naloxone precipitated withdrawal. Naïve rats and animals that were implanted with morphine pellets for 8 days did not display significant up‐regulation of ongoing neuropeptide expression in the parvocellular compartment of the PVH. In addition to hypophyseotropic neurons, naloxone precipitated withdrawal resulted in a marked activation in autonomic‐related projection neurons in PVH and in the magnocellular neurons in the PVH and supraoptic nuclei. These activations however were not associated with induction of CRH or AVP hnRNAs.
The β‐amyloid protein of Alzheimer’s disease binds to membrane lipids but does not bind to the α7 nicotinic acetylcholine receptor
Authors: Small David H. , Maksel Danuta , Kerr Megan L. , Ng Judy , Hou Xu , Chu Cindy , Mehrani Hossein , Unabia Sharon , Azari Michael F. , Loiacono Richard , Aguilar Marie‐Isabel , Chebib Mary 
Published: February 2007

AbstractAccumulation of the amyloid protein (Aβ) in the brain is an important step in the pathogenesis of Alzheimer’s disease. However, the mechanism by which Aβ exerts its neurotoxic effect is largely unknown. It has been suggested that the peptide can bind to the α7 nicotinic acetylcholine receptor (α7nAChR). In this study, we examined the binding of Aβ1‐42 to endogenous and recombinantly expressed α7nAChRs. Aβ1‐42 did neither inhibit the specific binding of α7nAChR ligands to rat brain homogenate or slice preparations, nor did it influence the activity of α7nAChRs expressed in Xenopus oocytes. Similarly, Aβ1‐42 did not compete for α‐bungarotoxin‐binding sites on SH‐SY5Y cells stably expressing α7nAChRs. The effect of the Aβ1‐42 on tau phosphorylation was also examined. Although Aβ1‐42 altered tau phosphorylation in α7nAChR‐transfected SH‐SY5Y cells, the effect of the peptide was unrelated to α7nAChR expression or activity. Binding studies using surface plasmon resonance indicated that the majority of the Aβ bound to membrane lipid, rather than to a protein component. Fluorescence anisotropy experiments indicated that Aβ may disrupt membrane lipid structure or fluidity. We conclude that the effects of Aβ are unlikely to be mediated by direct binding to the α7nAChR. Instead, we speculate that Aβ may exert its effects by altering the packing of lipids within the plasma membrane, which could, in turn, influence the function of a variety of receptors and channels on the cell surface.
Neonatal Seizures: Eyes Open or Closed?
Authors: Bauder Florian , Wohlrab Gabriele , Schmitt Bernhard 
Published: February 2007

Summary:  Purpose: It has been shown that persistent eye closure during paroxysmal events in infants makes seizures unlikely. Our study aims to assess whether this is also true in neonates. Methods: We reviewed and classified all archived neonatal seizures in our video database, considering electroclinical seizures only and excluding electrographic seizures and clinical seizures without ictal change in EEG. We assessed whether eyes were open during the seizure. One hundred and thirty‐one electroclinical seizures (clonic, focal and generalized tonic, tonic–clonic, generalized myoclonic, subtle and spasms) in 46 neonates were included. Results: In 115 (88%) seizures, eyes were open; in 10 seizures, they were closed; and in six seizures, eye opening could not be evaluated. All 10 seizures with persistent eye closure were clonic seizures. Conclusions: Our data demonstrate that persistent eye closure during an event suggestive of a seizure in a newborn makes an electroclinical seizure unlikely.
EEG‐fMRI in Children with Pharmacoresistant Focal Epilepsy
Authors: De Tiège Xavier , Laufs Helmut , Boyd Stewart G. , Harkness William , Allen Philip J. , Clark Chris A. , Connelly Alan , Cross J. Helen 
Published: February 2007

Summary:  Purpose: To evaluate the usefulness of EEG‐combined functional magnetic resonance imaging (EEG‐fMRI) to localize epileptogenic sources. Methods: Six children (age 8–15 years) with lesional or nonlesional pharmacoresistant focal epilepsy were studied. Results: We found significant activations in four children, activation and deactivation in one child, and widespread deactivation in another. In four children, activations colocalized with the presumed location of the epileptic focus, one of which was confirmed by intracranial EEG. Conclusions: EEG‐fMRI is a promising tool to noninvasively localize epileptogenic regions in children with pharmacoresistant focal epilepsy.
Modulation of AMPA Receptors in Cultured Cortical Neurons Induced by the Antiepileptic Drug Levetiracetam
Authors: Carunchio Irene , Pieri Massimo , Ciotti Maria Teresa , Albo Federica , Zona Cristina 
Published: February 2007

Summary: Purpose:The present study explores the hypothesis that the antiepileptic mechanism of action of levetiracetam (LEV) is related to effects on α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) receptor channels in mouse cortical neurons in culture.Methods:The neurons were subjected to the whole‐cell configuration of the patch‐clamp recording technique and were 8–12 days old in culture.Results:Kainate elicited concentration‐dependent (EC50= 80 μM) inward currents in all the patched cells. LEV (5–200 μM) itself did not induce inward or outward currents on all patched neurons, whereas it was effective on the kainate‐ and AMPA‐induced current because it significantly decreased the amplitude of these currents. LEV was also able to significantly decrease the total membrane conductance during kainate perfusion, indicating that its effect was not dependent on the cellular voltage membrane potential. Further evidence that LEV modulated the ionotropic non‐NMDA receptors came from the analysis of miniature excitatory postsynaptic currents (mEPSCs). In fact, LEV significantly decreased both the amplitude and the frequency of mEPSCs, as shown by the relative cumulative distributions.Conclusions:These results reveal that AMPA receptors are modulated by LEV because a significant decrease in the kainate‐ and AMPA‐induced currents and a decrease in amplitude and in frequency of mEPSCs have been observed in cortical neurons in culture. The described effect of LEV on AMPA receptors in cortical neurons is probably due to the etheromeric composition of the receptors and may be considered as a possible new antiepileptic mechanism of action.
Potential Factors That Affect Electrocardiographic Progression of Interatrial Block
Authors: Ariyarajah Vignendra , Kranis Mark , Apiyasawat Sirin , Spodick David H. 
Published: February 2007

Introduction: Interatrial block (IAB; P wave ≥ 110 ms) is associated with atrial tachyarrhythmias and left atrial electromechanical dysfunction. This subtle abnormality is highly prevalent and may exist as partial (pIAB) or advanced IAB (aIAB). Indeed, theoretically pIAB could progress to aIAB with worsening interatrial conduction over time. However, this has been poorly investigated. We retrospectively appraised this phenomenon and also evaluated the influence of common clinical factors such as coronary artery disease (CAD), hypertension (HTN), and use of antihypertensive medications. Methods: Between January 2003 and June 2004, 27 patients who had aIAB on routine 12‐lead ECGs were identified. Past serial ECGs of each patient were evaluated for evidence of change in IAB type. Medical records of respective patients were then reviewed for HTN, type of antihypertensive medication used, and other common comorbidities. Results: Median progression time from pIAB to aIAB was shorter (42 months; mean ± SD = 39.2 ± 30.5) compared to that of normal P wave (P‐normal) to aIAB (66 months; mean ± SD = 64.2 ± 25.6). Use of angiotensin‐converting enzyme inhibitors (ACEIs) appeared to significantly delay the progression time in patients who progressed from pIAB to aIAB (50.1 ± 28.3 vs 10 ± 10.4 months; P = 0.04). Beta‐adrenergic blocker use alone did not significantly affect either progression time but when used in conjunction with ACEIs, appeared to slow such progression. Conclusion: Progression time from pIAB to aIAB is shorter compared to that of P‐normal to aIAB. Given the consequences of IAB, awareness of such progression could be important for clinicians in anticipating potential sequelae.