bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disruption of Reproductive Aging in Female and Male Rats by Gestational Exposure to Estrogenic Endocrine Disruptors
Authors: Walker Deena M. , Kermath Bailey A. , Woller Michael J. , Gore Andrea C. 
Published: April 2013

Abstract
Polychlorinated biphenyls (PCBs) are industrial contaminants and known endocrine-disrupting chemicals. Previous work has shown that gestational exposure to PCBs cause changes in reproductive neuroendocrine processes. Here we extended work farther down the life spectrum and tested the hypothesis that early life exposure to Aroclor 1221 (A1221), a mixture of primarily estrogenic PCBs, results in sexually dimorphic aging-associated alterations to reproductive parameters in rats, and gene expression changes in hypothalamic nuclei that regulate reproductive function. Pregnant Sprague Dawley rats were injected on gestational days 16 and 18 with vehicle (dimethylsulfoxide), A1221 (1 mg/kg), or estradiol benzoate (50 μg/kg). Developmental parameters, estrous cyclicity (females), and timing of reproductive senescence were monitored in the offspring through 9 months of age. Expression of 48 genes was measured in 3 hypothalamic nuclei: the anteroventral periventricular nucleus (AVPV), arcuate nucleus (ARC), and median eminence (females only) by real-time RT-PCR. Serum LH, testosterone, and estradiol were assayed in the same animals. In males, A1221 had no effects; however, prenatal estradiol benzoate increased serum estradiol, gene expression in the AVPV (1 gene), and ARC (2 genes) compared with controls. In females, estrous cycles were longer in the A1221-exposed females throughout the life cycle. Gene expression was not affected in the AVPV, but significant changes were caused by A1221 in the ARC and median eminence as a function of cycling status. Bionetwork analysis demonstrated fundamental differences in physiology and gene expression between cycling and acyclic females independent of treatment. Thus, gestational exposure to biologically relevant levels of estrogenic endocrine-disrupting chemicals has sexually dimorphic effects, with an altered transition to reproductive aging in female rats but relatively little effect in males.
Hybrid Capture 2 Test Results After an Initial Equivocal RLU/CO Value Are Dependent on Age
Authors: Elkins Camille T. , de Vries Christiaan E. , Stephens Julie , Suarez Adrian A. 
Published: April 2013

Abstract
The effect of age on Hybrid Capture 2 (HC2) tests initially falling within the equivocal range has not been determined. We identified 359 cervicovaginal liquid cytology specimens with initial equivocal values. First and second retest relative light units/cutoff (RLU/CO) values were compared for women of 3 different age groups (15–29, 30–49, and ≥50 years). The proportion of first retests with an RLU/CO of less than 1 increased with age (P &lt; .001). Of the 56 second retests performed, only 4 had an RLU/CO of 1 or more. The proportion of “positive” HC2 results following the current HC2 algorithm decreased with increasing age (P &lt; .001), showing that HC2 test results after an initial equivocal value are dependent on age. Follow-up demonstrated cervical intraepithelial neoplasia grade 2 or worse (CIN2+) in 6 (5.9%) women 15 to 29 years old and in 5 (6.3%) women 30 to 49 years old. No CIN2+ was found on follow-up of 34 of 57 women 50 years and older. These results likely reflect human papillomavirus infection prevalence and question the use of identical cutoff values regardless of age for detection of CIN2+.
Failure of Current Laboratory Protocols to Detect Lot-to-Lot Reagent Differences: Findings and Possible Solutions
Authors: Algeciras-Schimnich Alicia , Bruns David E , Boyd James C , Bryant Sandra C , La Fortune Kristin A , Grebe Stefan KG 
Published: April 2013

BACKGROUND
Maintaining consistency of results over time is a challenge in laboratory medicine. Lot-to-lot reagent changes are a major threat to consistency of results.

METHODS
For the period October 2007 through July 2012, we reviewed lot validation data for each new lot of insulin-like growth factor 1 (IGF-1) reagents (Siemens Healthcare Diagnostics) at Mayo Clinic, Rochester, MN, and the University of Virginia, Charlottesville, VA. Analyses of discarded patient samples were used for comparison of lots. For the same period, we determined the distributions of reported patient results for each lot of reagents at the 2 institutions.

RESULTS
Lot-to-lot validation studies identified no reagent lot as significantly different from the preceding lot. By contrast, significant lot-to-lot changes were seen in the means and medians of 105 668 reported patient IGF-I results during the period. The frequency of increased results increased nearly 2-fold to a high of 17%, without detectable changes in the underlying patient demographics. Retrospective statistical analysis indicated that lot-to-lot comparison protocols were underpowered and that validation studies for this assay required testing &gt;100 samples to achieve 90% power to detect reagent lots that would significantly alter the distributions of patient results.

CONCLUSIONS
The number of test samples required for adequate lot-to-lot validation protocols is high and may be prohibitively large, especially for low-volume or complex assays. Monitoring of the distributions of patient results has the potential to detect lot-to-lot inconsistencies relatively quickly. We recommend that manufacturers implement remote monitoring of patient results from analyzers in multiple institutions to allow rapid identification of between-lot result inconsistency.
Volume growth of a powder snow avalanche
Authors: Louge Michel Y. , Turnbull Barbara , Carroll Cian 
Published: April 2013

AbstractWe contrast the frontal dynamics of dilute powder snow avalanches with the behavior of their tail. While the former can be regarded as a fast-moving eruption current dominated by synergistic material injection into a short head, the latter behaves as a nearly arrested dilute cloud of particles expanding by progressive incorporation of ambient air, or by entrainment of snow-cover material by late avalanches trailing well behind the front.
L’application de la charte des services bancaires de base : Réflexion sur l’accès aux services bancaires et sur l’exercice de la citoyenneté économique
Authors: Caffet Marie-Christine 
Published: April 2013

Low icome access to banking services in France
This article shows that, most of the time, only a few people are denied a deposit account : a recent study exhibited that only 5% of the requests were denied. The problem might be elsewhere, in the different banking services the low income are allowed access, or not.
JEL Classification : G21, G28, I30
Competition between stock exchanges and consequences for financial centres
Authors: Champarnaud François , Remay Vincent 
Published: April 2013

This article deals with increased competition between financial centres, which leads to mergers, as is the case with Euronext. Due to technological changes, the concept of geographic location seems to fade away ; however, the financial centre becomes now a place where the actors accept to play by the same rules.
JEL Classification : G18, L19
The location of investment banking business
Authors: Fleuriet Michel 
Published: April 2013

Since 1998, there have been more foreign banks in France than French ones. Many of these banks are wholesale banks or investment banks. This article reviews the factors that lead banks to locate their investment banking activities in a particular market. The author mentions three factors. First, history, and this holds true for the role within Europe of London where the first bond and equity issues of any significance took place. The second factor is the location of clients, be they issuers or investors. In the author’s view, however, trading activities can be located anywhere. The third factor is the growth strategy model of investment banks. This model, called a « tubular strategy », is characterized by development in a particular business segment followed by an offshoot in another segment in synergy with the first one. This growth model leads banks to operate close to specific client bases. The author illustrates his point with the example of HSBC, the second largest bank in the world. This model also explains the strong presence of US banks in Europe and finally the location of non-French banks in France. In conclusion, the impact of new technologies on the location of investment banks is mentioned.
JEL Classification : G24, R38
Un savoir faire entendre
Authors: Clavurier Vincent 
Published: April 2013

Dans un travail précédent sur le lapsus auditif (Verhören) , je proposai de considérer le savoir-faire du psychanalyste comme un savoir- verhören , un savoir entendre de travers. Mais que s’agit-il d’entendre, et par qui ? Le pas supplémentaire que je propose aujourd’hui est de considérer ce savoir-faire à la fois comme un faire savoir et un savoir faire entendre. Cela entraîne une série de questions : où était ce savoir littéralement inouï avant d’être su ? Est-il découvert ou inventé ? Un détour par le savoir mathématique sera éclairant et nous fournira également un schème topologique (l’hélice et plus exactement la spire) dont le repérage des occurrences dans le champ de la psychanalyse révèle un autre aspect du savoir-faire de l’analyste, celui d’une pratique de lecture topologique. Mais parler de savoir-faire semble également en rabattre sur l’idée de savoir constitué et démontrable et on se demandera si la notion de preuve est du coup cliniquement pertinente. Dans le fil de cette question, reprenant l’appellation « science conjecturale » proposée par Lacan, nous nous interrogerons sur le rôle discutable de l’hypothèse dans le savoir-faire du psychanalyste.
Der Bann
Authors: Cambon Fernand 
Published: April 2013

Deux conversations sur la singularité de la Corée-du-Nord associent un phénomène collectif d’une part à une sorte d’hypnose, d’autre part à une logique d’enfermement. Cela me donne l’idée d’étudier la convergence fréquente entre ces deux thématiques (par exemple le motif du « cercle magique »). Je suis alors renvoyé au mot allemand der Bann , dont la sémantique semble conjoindre les deux significations. (Ce mot a donné en français « le ban », à la sémantique nettement moins riche.) L’exploration de ce mot et des verbes afférents se révèle féconde. On se trouve alors face à un pouvoir, certes de vie et de mort, mais qui semble d’abord viser à inscrire et à projeter sa limite, réversible, dans un espace.
Cocaine and Amphetamines
Authors: Rebec George V 
Published: April 2013

Abstract

As stimulants, cocaine and amphetamines activate both the sympathetic and central nervous systems to heighten arousal, increase behavioural activation, and, when delivered rapidly to the brain, create the so‐called flash or rush followed by a long‐lasting state of euphoria. Cocaine, derived from coca leaves, and amphetamines, a group of synthetic compounds whose molecular structure resembles adrenalin, increase the level of norepinephrine (noradrenalin) and dopamine in the synapse. As part of the brain's reward circuit, dopamine neurons play a critical role in drug craving. The stimulant properties of cocaine and amphetamines have been known for centuries, but illicit manufacturing techniques now produce versions of these drugs that can be smoked or injected to enhance their pleasurable effects. Repeated drug use changes the way that neurons in the reward circuit process information. The end result is a fundamental change in brain circuitry that increases the likelihood of addiction.

Key Concepts:

Cocaine occurs naturally in coca leaves, which have been chewed for centuries to increase feelings of energy.

The amphetamines were modelled after ephedrine, a plant‐derived alkaloid that improves breathing and has stimulating effects on behaviour.

Cocaine and amphetamines activate the sympathetic nervous system by increasing the synaptic level of norepinephrine.

The rewarding or pleasurable effects of these drugs involve an increase in dopamine, a transmitter released in key areas of the forebrain.

Cocaine increases synaptic norepinephrine and dopamine by blocking the transporter proteins that removes these catecholamine transmitters from the synapse.

The amphetamines increase synaptic norepinephrine and dopamine by forcing the transporters to operate in reverse.

A direct increase in dopamine transmission in the nucleus accumbens, a part of the limbic forebrain, is common to many drugs of abuse and appears to be a key mechanism leading to addiction.

With repeated use of these drugs, long‐lasting changes occur in the accumbens and other key forebrain nuclei to promote drug craving and relapse.

Medically, cocaine is used as a local anaesthetic, whereas some amphetamines are used as treatment for narcolepsy and attention‐deficit‐hyperactivity disorder.

Caffeine and other xanthines are not as powerful in stimulating behaviour and act by blocking receptors for adenosine, a purine nucleotide.
Peptide Neurotransmitters and Hormones
Authors: Li Ka Wan 
Published: April 2013

Abstract

Neuropeptides are structurally diverse class of chemical messengers that play important roles in the coordination of many physiological and behavioural events. Neuropeptides are derived from the cleavage of the larger precursor proteins at the dibasic amino acid sites by prohormone convertases. They are synthesised in the cell body, packaged in the large dense core vesicles and released in a neuronal activity‐dependent manner. The neuropeptides may function as blood‐borne hormones, or as mediators/transmitters affecting neuronal activity in the nervous system. In the target cells, neuropeptides activate the complementary G protein‐coupled receptors and elicit responses that are specific to these cells. The released peptide is subsequently inactivated by the actions of several nonspecific extracellular peptidases.

Key Concepts:

Neuropeptides are structurally diverse class of chemical messengers produced by nerve cells to coordinate many physiological and behavioural processes.

The major neuroendocrine centre in the brain is the pituitary gland.

Neuropeptides are derived from the cleavage of the larger precursor proteins by specific endoproteases that are co‐packaged in the dense core secretory granules.

Receptors for neuropeptides belong mainly to the family of G protein‐coupled receptor.
Autonomic Nervous System
Authors: Gabella Giorgio 
Published: April 2013

Abstract

The autonomic nervous system (ANS) is a set of nerves and nerve cells that provide the innervation of blood vessels and the airways, heart, intestines and urogenital organs. These nerves regulate and coordinate bodily functions based on secretory activity of glands, on contraction and relaxation of smooth muscle and cardiac muscle, and on sensations arising from deep viscera.
Motor activity is a crucial function in hollow organs: muscle contraction propels fluids or solid bodies into tubes and ducts. Autonomic nerves control the motility of viscera, but there is also myogenic activity, generated spontaneously by the muscle itself. Myogenic and neurogenic controls are well balanced in the heart; myogenic control predominates in the muscles of intestine or uterus; neurogenic control predominates in the urinary bladder or the ductus deferens.
The sensory nerves provide ill‐localized but deep sensation about the state of the body, and can convey the sensation of pain (visceral pain).

Key Concepts:

A large array of nerves reaches the viscera and the vessels of the body from the central nervous system, and signals pass continuously in both directions.

Autonomic nerves control the motility (contraction, dilatation, tension) of cardiac muscle and of smooth muscle, both in viscera (visceral smooth muscle) and in blood vessels (vascular smooth muscle).

The musculature of viscera is under control of autonomic nerves, but, in some organs, it can also contract myogenically, that is, independently of external influences.

Autonomic pathways are chains of neurons and nerves linking brainstem and spinal cord to the peripheral organs.

Autonomic pathways contain nerve ganglia where nerve fibres synapse onto ganglion neurons and new nerve fibres are issues and travel peripherally.

Nerve fibres of the autonomic nerves are thin and often without a myelin sheath, and their conduction velocity is slower than in somatic nerves.

The autonomic nervous system (ANS) comprises sensory fibres, emerging from ganglion neurons in the dorsal root ganglia, which provide deep sensation about the state of the viscera and can convey the sensation of pain.

A special set of nerves forms the enteric nervous system, self‐contained and independent from other nerves.

In many parts of the ANS, at the surface of ganglion neurons, nerve endings and muscle cells there are receptors that are sensitive to neurotransmitters, to other neurochemicals, to hormones, to signalling molecules and to exogenously administered substances (pharmacological agents or drugs).
Dendrites
Authors: Ross William N , Larkum Matthew 
Published: April 2013

Abstract

Dendrites are highly branched neuronal structures that form the main synaptic target of other nerve cells. They are studded with small spines that are the contact points for excitatory inputs. Dendrites integrate these excitatory inputs, along with inhibitory inputs, in the form of brief depolarising or hyperpolarizing synaptic potentials, and generate the output of the neuron. This signal is usually in the form of an action potential initiated near the soma. Although early models assumed that the dendrites were passive, we now know that they have many voltage dependent conductances distributed heterogeneously over the surface of the arbours. These conductances lead to various forms of signal modulation and localised regenerative activity that greatly expand the computational complexity of CNS neurons.

Key Concepts:

Dendrites comprise approximately 95% of the neuronal surface and are the main place where synaptic contacts are made.

Dendritic architecture is stereotypical for different neurons types and probably relates to the integrative function of these cells.

Synaptic potentials originate in the dendrites and propagate decrementally to the axon hillock where the output sodium spike is usually generated.

Dendrites contain voltage‐dependent channels distributed in ways characteristic to each cell type, which modulate the propagation of synaptic potentials.

These voltage‐dependent channels can also support regenerative action potentials, which either back‐propagate over the dendrites from the somatic region, or are initiated locally in the dendrites.

These dendritic action potentials are complex. They are primarily sodium dependent, calcium dependent, or, in some cases, involve the ligand‐gated NMDA receptor.

The function of these dendritic action potentials is not always clear. One possibility is to control the calcium concentration in different parts of the cell, which can then regulate synaptic plasticity or other signalling mechanisms. Another possibility is to influence the integration of synaptic potentials and ultimately determine the output of the neuron.
Glutamate as a Neurotransmitter
Authors: Mennerick Steven , Zorumski Charles F 
Published: April 2013

Abstract

Glutamate is a major excitatory neurotransmitter in the vertebrate central nervous system (CNS). Glutamate is released from vesicles that reside at axon terminals of neurons that use this amino acid as a neurotransmitter. Vesicular release is triggered by the arrival of a brief electrical signal (the action potential) at the presynaptic terminal. Most neurons in the vertebrate CNS, even if they themselves do not use glutamate as a neurotransmitter, are contacted by glutamate presynaptic terminals. Glutamate receptors mediate signalling initiated by glutamate release and are involved in plastic changes in the nervous system. These receptors fall into two classes: G protein coupled (metabotropic) and ligand‐gated ion channels (ionotropic). Ionotropic glutamate receptor activation on the target cell initiates a brief electrical depolarisation, which if large enough, causes an action potential in the target cell, and the cycle of signalling begins again. Excessive activation of glutamate receptors can cause neurotoxicity.

Key Concepts:

Glutamate is used as a neurotransmitter at the majority of synapses in the vertebrate CNS.

Glutamate generally has an excitatory action on target neurons, increasing the probability of action potential firing in the target.

Glutamate acts through G protein coupled receptors and through ligand‐gated ion channels.

Glutamate synapses exhibit remarkable plasticity (malleability) that may play an important role in memory formation.

In excess glutamate can be neurotoxic, acting through the same glutamate receptors that mediate normal signalling.
Motor Output from the Brain and Spinal Cord
Authors: Berkowitz Ari 
Published: April 2013

Abstract

All skeletal muscles are controlled by activation and inhibition of motor neurons in the spinal cord and brainstem. Motor neurons integrate information from a wide variety of sources in the brain and spinal cord. Simple limb reflexes and basic patterns of limb movements, including locomotion, are coordinated by spinal cord interneurons and sensory neurons. Descending inputs from the reticular formation, the vestibular nuclei and the superior colliculus in the brainstem are important in the control of automatic, axial, postural and locomotor movements. Descending inputs from several areas of the cerebral cortex and from the red nucleus are important in the control of voluntary, distal limb and fine movements. The basal ganglia in the basal forebrain and the cerebellum in the hindbrain are involved in the modification and learning of movements. These structures act indirectly on motor output, via outputs through the thalamus to widespread areas of the cerebral cortex.

Key Concepts:

All voluntary movement involves motor neurons in the spinal cord and brainstem that cause contraction of skeletal muscles.

Neurons in many areas of the brain and spinal cord are active at overlapping times to control voluntary movements.

The spinal cord can produce coordinated movements of the limbs, such as locomotion, as well as simple reflexes.

The superior colliculus can trigger orienting movements, especially of the eyes and head.

Voluntary limb movements involve neurons in several parts of the cerebral cortex, including especially the frontal lobe, which project axons to the spinal cord.

Cortical movement control signals are modified by loops to and from the basal ganglia and the cerebellum, going through the thalamus.

The basal ganglia modify the speed and amplitude of movements and contribute to learning new movement sequences.

The cerebellum adapts movements to altered sensory feedback and may also contribute to a wide variety of other functions, including memory, language and emotion.

Patients with movement disorders may in the future be able to control a limb or prosthetic device with ‘their thoughts’, via a brain–machine interface that monitors the activity of some of their cortical neurons.