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Transmitters
Kinds of Transmitters Selected AbstractsFine-scale movements of the swordfish Xiphias gladius in the Southern California BightFISHERIES OCEANOGRAPHY, Issue 4 2010CHUGEY A. SEPULVEDA Abstract This study reports on the fine-scale movements of swordfish (Xiphias gladius) outfitted with pop-off satellite archival transmitters (PSATs) in the Southern California Bight (SCB). PSATs were deployed on basking swordfish using traditional harpoon methods from 2004 to 2006. Transmitters were programmed for short-term deployment (2,90 days) and re-acquired using a signal direction finder. High-resolution (min,1) depth and temperature data from nine swordfish (approximately 45,120 kg) were collected (>193 days). All swordfish displayed diurnal vertical movements similar to those reported for other geographic locations. The dominant diurnal movement pattern entailed swordfish remaining below the thermocline (>68 ± 15 m) during the day and near the surface, within the upper-mixed layer, at night. Collectively, the average daytime depth (±SE) was 273 ± 11 m and the average night depth 31 ± 5 m. Three distinct vertical behaviors were recorded: 35% of the records following a strict diurnal pattern, with the entire day below the thermocline and the entire night near the surface; 52% of the records revealed routine surface-basking events during the day, with an otherwise similar distribution at night; and 13% of the records exhibited surface-oriented activity during the day and night. Surface basking (<3 m during the day) was recorded for eight individuals and occurred on 131 of the 193 days (68% of the dataset). Collectively, surface basking accounted for 8% of the total daytime records. The relevance of these vertical behaviors to SCB fisheries is discussed. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2010Article first published online: 29 JUN 2010 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Reviews; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2010Article first published online: 29 DEC 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Reviews; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2008Article first published online: 22 MAY 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Reviews; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 3 2008Article first published online: 31 MAR 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Reviews; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2007Article first published online: 2 AUG 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Reviews; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 8 2006Article first published online: 29 NOV 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Books, Reviews & Symposia; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2006Article first published online: 9 OCT 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Books, Reviews & Symposia; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current awareness in human psychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 3 2005Article first published online: 30 MAR 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Books, Reviews & Symposia; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current Awareness in Human PsychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2003Article first published online: 19 MAY 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Books, Reviews & Symposia; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Current Awareness in Human PsychopharmacologyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2002Article first published online: 24 SEP 200 In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of human psychopharmacology. Each bibliography is divided into 18 sections: 1 Books, Reviews & Symposia; 2 General; 3 Psychotropic Drugs - General; Antidepressive Agents: 4 Tricyclics; 5 Monoamine Oxidase Inhibitors; 6 Serotonergics; Euthymic Agents: 7 Lithium; Tranquillizing Agents: 8 Major; 9 Minor & Hypnotics; 10 Analeptic Agents; 11 Anticonvulsant Agents; 12 Drugs of Abuse; 13 Transmitters, Receptors, Metabolites & Modulating Agents; 14 Neuropeptides; 15 Psychoneuroendocrinology; 16 Psychoneuroimmunology; 17 Behavioural Genetics; 18 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. [source] Computer package development: Applications to engineering educationCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2001Salah A. Almajdoub Abstract A well developed program that uses flow graph theory to calculate the steady state probabilities is presented in this paper. Two examples are tested, and their results are successfully obtained. The first model is a seven state model and represents two transmitters fed from a common power supply unit. The second model is an eight-state model which represents three electric generators supplying part of State of Bahrain electrical network. The high accuracy and the time saving advantages show that the proposed method gives excellent agreement with the results obtained by the Runge-Kutta method. © 2001 John Wiley & Sons, Inc. Comput Appl Eng Educ 9: 20,25, 2001 [source] Applying Network Analysis to the Conservation of Habitat Trees in Urban Environments: a Case Study from Brisbane, AustraliaCONSERVATION BIOLOGY, Issue 3 2006MONIKA RHODES conectividad de perchas; fauna que utiliza oquedades; planificación de la conservación; red sin escala; Tadarida australis Abstract:,In Australia more than 300 vertebrates, including 43 insectivorous bat species, depend on hollows in habitat trees for shelter, with many species using a network of multiple trees as roosts. We used roost-switching data on white-striped freetail bats (Tadarida australis; Microchiroptera: Molossidae) to construct a network representation of day roosts in suburban Brisbane, Australia. Bats were caught from a communal roost tree with a roosting group of several hundred individuals and released with transmitters. Each roost used by the bats represented a node in the network, and the movements of bats between roosts formed the links between nodes. Despite differences in gender and reproductive stages, the bats exhibited the same behavior throughout three radiotelemetry periods and over 500 bat days of radio tracking: each roosted in separate roosts, switched roosts very infrequently, and associated with other bats only at the communal roost. This network resembled a scale-free network in which the distribution of the number of links from each roost followed a power law. Despite being spread over a large geographic area (>200 km2), each roost was connected to others by less than three links. One roost (the hub or communal roost) defined the architecture of the network because it had the most links. That the network showed scale-free properties has profound implications for the management of the habitat trees of this roosting group. Scale-free networks provide high tolerance against stochastic events such as random roost removals but are susceptible to the selective removal of hub nodes. Network analysis is a useful tool for understanding the structural organization of habitat tree usage and allows the informed judgment of the relative importance of individual trees and hence the derivation of appropriate management decisions. Conservation planners and managers should emphasize the differential importance of habitat trees and think of them as being analogous to vital service centers in human societies. Resumen:,En Australia, más de 300 vertebrados, incluyendo 43 especies de murciélagos insectívoros, dependen de oquedades en árboles para refugiarse; muchas de ellas perchan en una red de múltiples árboles. Utilizamos datos de cambio de perchas en Tadarida australis (Microchiroptera: Molossidae) para construir una representación reticular de las perchas diurnas en los suburbios de Brisbane, Australia. Los murciélagos fueron capturados en un árbol con un grupo de varios cientos de individuos y liberados con transmisores. Cada percha utilizada por los murciélagos representó un nodo individual en la red, y los movimientos de murciélagos entre perchas constituyeron los eslabones entre los nodos. A pesar de las diferencias de género y etapas reproductivas, los murciélagos mostraron el mismo comportamiento en tres períodos de radiotelemetría y en más de 500 días de seguimiento de murciélagos: cada uno utilizó perchas separadas, cambiaban de percha poco frecuentemente, y se asociaron con otros murciélagos sólo en las perchas comunales. Esta red fue semejante a una red sin escala en la que la distribución del número de eslabones de cada percha cumplió una ley potencial. A pesar de estar dispersas en un área geográfica extensa (>200 km2), cada percha estaba conectada con otras por menos de tres eslabones. Una percha (el centro o percha comunal) definió la arquitectura de la red porque tenía a la mayoría de los eslabones. El hecho de que la red mostrara propiedades libres de escala tiene implicaciones profundas para la gestión de árboles que funcionan como perchas. Las redes libres de escala proporcionan alta tolerancia a eventos estocásticos como la remoción aleatoria de perchas, pero son susceptibles a la remoción selectiva de nodos centrales. El análisis de redes es una herramienta útil para el entendimiento de la organización estructural del uso de de árboles y permite el juicio informado de la importancia relativa de árboles individuales y por lo tanto la derivación de decisiones administrativas apropiadas Los planificadores y gestores de la conservación deberían enfatizar la importancia diferencial de árboles y considerarlos análogos a los centros de servicio vitales en las sociedades humanas. [source] Neuroanatomy and neurophysiology of itchDERMATOLOGIC THERAPY, Issue 4 2005Joanna Wallengren ABSTRACT:, The specific pathway of "pure," histaminergic itch is traced from the mechano-insensitive nerve fibers in the skin to their central cortical projections. Neuropathic itch created at different levels of this anatomical pathway is reviewed. In this review the present author discusses damage to pruritoceptors in the skin, entrapment syndromes, damage to spinal ganglia, nerve root impingement, injury of the spinal cord, and cerebral damage in the distribution of the middle cerebral artery, capsula interna, or thalamus. Itch in inflamed skin resulting from interactions between nerve transmitters and other mediators of inflammation is described. [source] Dopamine modulation of the In vivo acetylcholine response in the Drosophila mushroom bodyDEVELOPMENTAL NEUROBIOLOGY, Issue 11 2009Vitold Tsydzik Abstract Olfactory sensory information in Drosophila is transmitted through antennal lobe projections to Mushroom Body neurons (Kenyon cells) by means of cholinergic synapses. Application of acetylcholine (ACh) and odors produce significant increases in intracellular calcium ([Ca2+]i) in these neurons. Behavioral studies show that Kenyon cell activity is modulated by dopaminergic inputs and this modulation is thought to be the basis for an olfactory conditioned response. However, quantitative assessment of the synaptic inputs to Kenyon cells is currently lacking. To assess neuronal activity under in vivo conditions, we have used the endogenously-expressed camgaroo reporter to measure [Ca2+]i in these neurons. We report here the dose-response relationship of Kenyon cells for ACh and dopamine (DA). Importantly, we also show that simultaneous application of ACh and DA results in a significant decrease in the response to ACh alone. In addition, we show inhibition of the ACh response by cyclic adenosine monophosphate. This is the first quantitative assessment of the effects of these two important transmitters in this system, and it provides an important basis for future analysis of the cellular mechanisms of this well established model for associative olfactory learning. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source] Using motion-sensitive radio tags to record the activity and behavioural patterns of spawning Atlantic salmonECOLOGY OF FRESHWATER FISH, Issue 2 2009P. Karppinen Abstract,,, In this paper, we describe a method employing motion-sensing radio transmitters for recording and identifying behavioural patterns and activity of Atlantic salmon spawning under natural conditions. Simultaneous video monitoring verified recorded activity patterns originating from behaviours such as fighting, nest digging and quivering. The method described here enables more accurate determination of the timing and location of spawning compared to conventional location tracking. Motion-sensing transmitters can also be applied to monitor other species and types of behaviour, and therefore the use and development of such methods deserves further attention in behavioural studies. [source] Effect of habitat fragmentation on spawning migration of brown trout (Salmo trutta L.)ECOLOGY OF FRESHWATER FISH, Issue 3 2006C. Gosset Abstract , Human-induced habitat alteration is one of the main causes of the decline of freshwater fish populations. The watershed of the River Bidasoa (Spain) is an example of heavily fragmented habitat. The local brown trout (Salmo trutta L.) population is disturbed, with evidence of poor recruitment as well as low adult densities in the main stem. Forty male and female adult migratory trout were tagged with external or internal radio transmitters and released. Fixed stations with data loggers and mobile antennae were used with daily surveys to track fish movements during the migration and spawning period (3 months). Migration distances did not exceed 10 km, and half of the fish never entered a tributary in the study area. Fragmentation because of weirs on the main stem apparently prevented fish from reaching their spawning destination. Fish that entered the tributaries were first confronted with an accessibility problem because of low discharge. However, each fish chose one tributary, without making attempts to run up in other tributaries. Once in the tributary, fish were restrained in their upstream movements by dams. The study area appeared to be isolated from the vast upper part of the watershed. Within the study area, upper parts of tributaries also seemed strongly disconnected from the main stem. This study illustrates the negative impact of river fragmentation on S. trutta migration pattern. Population sustainability can be directly affected through the low availability of spawning grounds for migratory fish. Long-term effects of fragmentation may cause reproductive isolation within watersheds, which in the case of trout also means isolated phenotypic population units. [source] Effects of radio-transmitter antenna length on swimming performance of juvenile rainbow troutECOLOGY OF FRESHWATER FISH, Issue 4 2004K. J. Murchie Abstract,,, Technological advances have lead to the production of micro radio-transmitters capable of being implanted in fish as small as c. 5 g. Although the actual tags are small, transmitters are equipped with long antennas that can increase drag and tangle in debris. We examined the effects of radio-transmitter antenna length on the swimming performance of juvenile rainbow trout, Oncorhynchus mykiss, (N = 156, mean mass = 34 g, mean fork length = 148 mm). Although we tested a variety of different antenna lengths up to a maximum of 300 mm, only the longest antenna significantly impaired swimming performance relative to control fish (P < 0.001). There was no difference in swimming performance between the sham (surgery, but no transmitter) and the control fish (handled, but no surgery), suggesting that the surgical procedure itself did not negatively affect the fish. Regression analysis, however, indicated that there was a significant decrease in swimming performance associated with increased antenna length (R2 = 0.11, P < 0.001). In addition, when held in laboratory tanks, fish with the three longest antennas (150, 225 and 300 mm) frequently became entangled with the standpipe. We suggest that researchers, under the guidance of the tag manufacturer, trim antennas to the shortest possible length required to detect fish in their specific study area. Antenna length is clearly an important issue for small fish, especially for species that inhabit complex habitats where antennas may become entangled, and where fish must attain speeds near limits of their swimming capacity. Resumen 1. Los avances tecnológicos han llevado a producir micro radio-trasmisores capaces de ser implantados en peces de muy pequeño tamaño (,5 g). Aunque las marcas actuales son pequeñas, los trasmisores están equipados con antenas largas que pueden llegar a enredarse en los restos de vegetación. Examinamos los efectos de la longitud de la antena sobre la rutina natatoria de juveniles de Oncorhynchus mykiss (n = 156, peso medio = 34 g, longitud furcal media = 148 mm). 2. Aunque analizamos varias longitudes de antena, hasta 300 mm, solamente las de mayor longitud alteraron la rutina natatoria en relación a los peces control (P < 0.001). No hubo diferencia en la rutina natatoria entre individuos bajo cirugía pero sin trasmisores respecto de los individuos control (manipulados pero sin cirugía) lo que sugiere que los procedimientos de cirugía no afectaron negativamente a los peces. Sin embargo, análisis de regresión indicaron un declive significativo en la rutina natatoria asociado a la longitud de la antena (R2 = 0.11, P < 0.001). Además, al ser mantenidos en tanques, los individuos con las tres antenas mas largas (150, 225, y 300 mm) frecuentemente se enredaron con las tuberías. 3. Sugerimos a los investigadores que, bajo la dirección de los productores de marcas y antenas, consideren el uso de las antenas más pequeñas que permitan detectar a los peces en sus respectivas áreas de estudio. La longitud de la antena es una cuestión importante para los pequeños peces, especialmente para especies en hábitats complejos donde las antenas pueden llegar a enredarse y donde los peces pueden alcanzar velocidades casi al limite de su capacidad natatoria. [source] Accumulation of DDT and mercury in prothonotary warblers (Protonotaria citrea) foraging in a heterogeneously contaminated environmentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Kevin D. Reynolds Abstract Foraging areas of adult prothonotary warblers (Protonotaria citrea) were determined using standard radiotelemetry techniques to determine if soil concentrations of p,p,dichlorodiphenyltrichloroethane (p,p,DDT) and mercury in foraging areas could be used to predict contaminant levels in diets and tissues of nestling warblers. Adult warblers were fitted with transmitters and monitored for approximately 2 d while foraging and feeding 6- to 8-d-old nestlings. Foraging ecology data were integrated with contaminant levels of soil, diets, and tissues into a comprehensive analysis of geographic variation in contaminant exposure and uptake using linear regression. Concentrations of 1,1-dichloro-2,2-bis(p -chlorophenyl)ethylene (DDE) and mercury in nestling tissues varied considerably across the study site. Mean concentration of DDE was greater in eggs than all other tissues, with individual samples ranging from 0.24 to 8.12 ,g/kg. In general, concentrations of DDT in soil were effective in describing the variation of contaminants in adipose samples. Concentrations of mercury in soils accounted for 78% of the variation in kidney samples. This was the best relationship of any of the paired variables. All other relationships showed relatively poor predictive ability. [source] Switching of the transmitters that mediate hindbrain correlated activity in the chick embryoEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2009Hiraku Mochida Abstract Widely propagating correlated neuronal activity is a hallmark of the developing nervous system. The activity is usually mediated by multiple transmitters, and the contribution of gap junctions has also been suggested in several systems. In some structures, such as the retina and spinal cord, it has been shown that the dominant transmitter mediating the correlated wave switches from acetylcholine to glutamate during development, although the functional significance of this phenomenon has not been clarified. An important question is whether such a transmitter switch occurs in other systems, especially in the brain. In the present study, we demonstrate that the major transmitter mediating correlated wave activity in the embryonic chick hindbrain changes from acetylcholine/,-aminobutyric acid (GABA)/glycine to glutamate/GABA as development proceeds. The results show for the first time that the dominant transmitter switches from acetylcholine to glutamate in a region other than the retina and spinal cord. This finding sheds more light on the role of nicotinic acetylcholine receptors in the generation of correlated wave activity, which is considered to regulate the development of the nervous system. [source] Expression of histamine receptors and effect of histamine in the rat carotid body chemoafferent pathwayEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2006Nikolai Lazarov Abstract Chemosensory information from peripheral arterial oxygen sensors in the carotid body is relayed by petrosal ganglion neurons to the respiratory networks in the medulla oblongata. Biogenic amines, including histamine, released from glomus (type I) cells of the carotid body are considered to be primary transmitters in hypoxic chemosensitivity. Immunocytochemistry at light-and electron-microscopical levels, and RT-PCR, revealed the expression of histamine receptors 1 and 3 as well as histidine decarboxylase in the rat carotid body glomus cells and petrosal ganglion neurons. Histamine receptors 1 and 3, but not histidine decarboxylase, were also observed in the ventrolateral, intermediate and commissural subnuclei of the nucleus tractus solitarii in the medulla oblongata. In order to examine the possible role of histamine in the afferent branch of the respiratory system, we applied histamine receptor 1 and 3 agonists to the carotid body, which caused a mildly increased phrenic nerve activity in a working heart,brainstem preparation. Moreover, microinjection of antagonists of histamine receptors 1 and 3 into the nucleus tractus solitarii caused significant changes in the inspiratory timing and the chemoreceptor response. Our data show that histamine acting via histamine receptors 1 and 3 plays an important neuromodulatory role in the afferent control of chemosensitivity. [source] Differential galanin receptor-1 and galanin expression by 5-HT neurons in dorsal raphé nucleus of rat and mouse: evidence for species-dependent modulation of serotonin transmissionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Jari A. Larm Abstract Galanin and galanin receptors are widely expressed by neurons in rat brain that either synthesize/release and/or are responsive to, classical transmitters such as ,-aminobutyric acid, acetylcholine, noradrenaline, histamine, dopamine and serotonin (5-hydroxytryptamine, 5-HT). The dorsal raphé nucleus (DRN) contains , 50% of the 5-HT neurons in the rat brain and a high percentage of these cells coexpress galanin and are responsive to exogenous galanin in vitro. However, the precise identity of the galanin receptor(s) present on these 5-HT neurons has not been previously established. Thus, the current study used a polyclonal antibody for the galanin receptor-1 (GalR1) to examine the possible expression of this receptor within the DRN of the rat and for comparative purposes also in the mouse. In the rat, intense GalR1-immunoreactivity (IR) was detected in a substantial population of 5-HT-immunoreactive neurons in the DRN, with prominent receptor immunostaining associated with soma and proximal dendrites. GalR1-IR was also observed in many cells within the adjacent median raphé nucleus. In mouse DRN, neurons exhibited similar levels and distribution of 5-HT-IR to that in the rat, but GalR1-IR was undetectable. Consistent with this, galanin and GalR1 mRNA were also undetectable in mouse DRN by in situ hybridization histochemistry, despite the detection of GalR1 mRNA (and GalR1-IR) in adjacent cells in the periaqueductal grey and other midbrain areas. 5-HT neuron activity in the DRN is primarily regulated via 5-HT1A autoreceptors, via inhibition of adenylate cyclase and activation of inward-rectifying K+ channels. Notably, the GalR1 receptor subtype signals via identical mechanisms and our findings establish that galanin modulates 5-HT neuron activity in the DRN of the rat via GalR1 (auto)receptors. However, these studies also identify important species differences in the relationship between midbrain galanin and 5-HT systems, which should prompt further investigations in relation to comparative human neurochemistry and which have implications for studies of animal models of relevant neurological conditions such as stress, anxiety and depression. [source] Hypocretin (orexin) in the rat pineal gland: a central transmitter with effects on noradrenaline-induced release of melatoninEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2001Jens D. Mikkelsen Abstract Hypocretin-1 (HCRT-1) and hypocretin 2 (HCRT-2), also known as orexin-A and orexin-B, are two neuropeptides derived from the same precursor. Hypocretinergic neurons have been found exclusively in the hypothalamic dorsolateral area. These neurons are implicated in sleep and feeding through activation of specific G-protein-coupled orexin-1 and orexin-2 receptor (OR-R1 and OR-R2). The purpose of this study was to determine the existence of the HCRT peptides in the central input of the rat pineal gland. Further, OR-R1 and OR-R2 expression was determined in the pineal gland and the effect of HCRT-2 on melatonin synthesis and secretion was analysed in dissociated rat pinealocytes. A large contingent of HCRT-positive nerve fibres and terminals were observed in the epithalamus, many of which entered into the pineal parenchyma. A significant number of nerve fibres endowed with positive boutons were identified in the pineal stalk, though the number of positive fibres decreased along the extension of the stalk. So far, no positive fibres have been found in the superficial pineal gland. RT-PCR analysis revealed the expression of OR-R2 mRNA, whereas OR-R1-receptor mRNA was not detected. When tested alone, HCRT-2 had no effect on secretion of melatonin from cultured rat pinealocytes. However, HCRT-2 partially inhibited (by a maximum of 30%) the ,-adrenergic-induced melatonin secretion. The same effect was seen on activation of N-acetyltransferase activity. The distribution and the large number of HCRT-positive fibres together with the effect on noradrenaline-mediated melatonin release through specific receptors suggests that these peptides may be significant central transmitters in pineal function, probably mediating homeostatic signals to the pineal gland. [source] Two-stage detection of partitioned random CDMAEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2008Lukasz Krzymien Random Code Division Multiple Access (CDMA) with low complexity two-stage joint detection/decoding is considered. A sequence partitioning approach is used for modulation, where every spreading sequence is divided into M sections (partitions) which are interleaved prior to transmission. This setup, called partitioned CDMA, can be understood as a generalisation of (chip) interleave division multiple access (IDMA). An analysis of a low-complexity iterative cancellation receiver is presented for arbitrary received power distributions. It is shown that for equal rate and equal power users the asymptotic performance of partitioned CDMA is equal to the performance of CDMA with optimal a posteriori probability (APP) detection for system loads K/N,<,1.49. Effects of asynchronous signal transmission are quantified for standard pulse shaping filters and it is shown that the signal-to-noise ratios achievable in an asynchronous system are improved with respect to fully synchronous transmission. The effect of unequal received powers is examined and considerable gains in performance are obtained by judicious choices of power distributions. For certain power distribution, partitioned CDMA with iterative detection can achieve arbitrary system loads, that is detection is no longer fundamentally interference limited. The practical near-far resistance of the proposed system is illustrated using an example of a receiver with a circular receive footprint and uniformly distributed transmitters (single cell system). Copyright © 2008 John Wiley & Sons, Ltd. [source] Load-Adaptive MUI/ISI-Resilient Generalized Multi-Carrier CDMA with Linear and DF ReceiversEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 6 2000Georgios B. Giannakis A plethora of single-carrier and multi-carrier (MC) CDMA systems have been proposed recently to mitigate intersymbol interference (ISI) and eliminate multiuser interference (MUI). We present a unifying all-digital Generalized Multicanier CDMA framework which enables us to describe existing CDMA schemes and to highlight thorny problems associated with them. To improve the bit error rate (BER) performance of existing schemes, we design block FIR transmitters and decision feedback (DF) receivers based on an inner-code/outer-code principle, which guarantees MUI/ISI-elimination regardless of the frequency-selective physical channel. The flexibility of our framework allows further BER enhancements by taking into account the load in the system (number of active users), while blind channel estimation results in bandwidth savings. Simulations illustrate the superiority of our framework over competing MC CDMA alternatives especially in the presence of uplink multipath channels. [source] Simple On-Line Scheduling Algorithms for All-Optical Broadcast-and-Select NetworksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2000Marco Ajmone Marsan This paper considers all-optical broadcast networks providing a number of slotted WDM channels for packet communications. Each network user is equipped with one tunable transmitter and one fixed receiver, so that full connectivity can be achieved by tuning transmitters to the different wavelengths. Tuning times are not negligible with respect to the slot time. A centralized network controller allocates slots in a TDWDM frame according to (long-term) bandwidth requests issued by users. Simple on-line transparent scheduling strategies are proposed, which accommodate bandwidth requests when they are received (on-line approach), with the constraint of not affecting existing allocations when a new request is served (transparency). Strategies that attempt to allocate in contiguous slots all the transmissions of each source on one wavelength reduce overheads, are simple, and provide good performance. Even better performance can be achieved, at the cost of a modest complexity increase, when the transparency constraint is not strictly imposed, i.e., when a full re-allocation of existing connections is performed once in a while. [source] Introduction of a new physiological acoustic electromyogram transmitterFISHERIES MANAGEMENT & ECOLOGY, Issue 5-6 2008G. LEMBO Abstract, Electromyogram (EMG) radio transmitters have proven to be a useful tool to monitor activity levels in free swimming fish. Unfortunately, the availability of the EMG transmitter in only radio mode limited its use to the freshwater environment. Applications in the marine environment are numerous and include monitoring activity levels in both wild and cultured finfish. This study presents preliminary data from trials examining activity levels in free swimming sea bass, Dicentrarchus labrax, L., using an acoustic EMG transmitter. Three adult sea bass were surgically implanted with the newly created prototype EMG transmitters. Signals from the transmitter were calibrated to swimming speed using a Bla,ka-style chamber. Swimming trials showed a high correlation between EMG signal and swimming velocity (r2 = 0.978) and were described using a sigmoid model. No significant differences (P < 0.05) were found among the four swimming trials conducted on the same fish or among the trials of the three different fish, indicating minimum variation from the prototypes tested. [source] Temperature-sensing telemetry , possibilities for assessing the feeding ecology of marine mammals and their potential impacts on returning salmonid populationsFISHERIES MANAGEMENT & ECOLOGY, Issue 5-6 2008B. BENDALL Abstract, Adult salmonids returning to the River Tees (north-east England) tagged with temperature-sensing acoustic transmitters provided some unexpected and novel information on the possible impact of seal predation at a tidal barrage 16 km from the sea. Predation events of tagged fish by seals were inferred by an increase in the temperature transmitted by the acoustic tags. Subsequent events of feeding or drinking by the seals were also inferred from further changes in temperature recorded by tags whilst in their stomachs. Rates of inferred predation on tagged individuals were high (47%). This is the first time that temperature-sensing transmitters deployed inside wild salmonids have revealed instances of predation by, and subsequent feeding ecology of, marine mammals. The results are discussed in relation to the use of such technology in future studies attempting to address the interactions between marine mammals and their fish prey species. [source] Return migration of adult Atlantic salmon, Salmo salar, in relation to water diverted through a power stationFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2003E. B. Thorstad Abstract ,The migration of Atlantic salmon, Salmo salar L., returning to the River Suldalslågen, Norway, was studied in relation to redirection of freshwater flow through a power station. The outlet of the power station is situated in the Hylsfjord, a fjord adjacent to the river mouth. Seventy-two salmon were tagged with acoustic transmitters, released in the outer part of the fjord system and automatically recorded when entering the Hylsfjord or the river. Data were collected during one period when the power station was running and two periods when the power station was closed. The release of water from the power station did not greatly attract the salmon during their return migration. Proportions of salmon entering the river or time from release to entering the river did not differ among salmon tagged in the different periods. The salmon were recorded in the Hylsfjord both when the power station was running and closed and there were no differences in number of times, number of days or hours recorded in the Hylsfjord among salmon tagged in the three periods. The only significant difference found among periods was duration of continuous stays in the inner part of the Hylsfjord. This may indicate a slight attraction to the freshwater release, but the difference seems small (1.8 vs. 0.7 h) compared with the time the fish stayed in the fjord system before entering the river (16,85 days). [source] Prespawning migratory behaviour and spawning success of sea-ranched Atlantic salmon, Salmo salar L., in the River Gudenaa, DenmarkFISHERIES MANAGEMENT & ECOLOGY, Issue 5 2000K. Aarestrup The migratory behaviour of sea-ranched Atlantic salmon, Salmo salar L., was analysed by radio-telemetry in the River Gudenaa, Denmark. The main objectives were to: (1) estimate mortality of returning adults through the fjord; (2) observe rate of progression and migratory pattern in the fjord and river; and (3) record whether spawning occurs in the river. Forty-two returning salmon (19 males and 23 females of total body length from 60,97 cm) reared and released as smolts, were caught and equipped with external radio transmitters in the outer estuary of the River Gudenaa in 1994 and 1995. Of the tagged salmon, 18 (43%) were caught in the estuary, four (10%) were not recorded after release and 20 (47%) entered the river. The mean rate of progression through the fjord was 7.6 km d,1 (range 1.4,18.2) in 1994 and 5.4 km d,1 (range 1.6,17.1) in 1995. Eleven salmon were alive at the onset of the spawning period. Eight were retrieved dead from the river during or after the spawning period; four with empty gonads assumed to be successful spawners, and four with intact gonads. In 1994, unsuccessful spawners (found dead with intact gonads) entered the river earlier and had a longer total migration distance in the river compared to successful spawners. This suggests that spawning success of sea-ranched salmon is associated with time of river entry and river migration length. [source] | |||||||||||||||||||||||||||||||||||||||||||