bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous artery‐selective spin labeling (CASSL)
Authors: Werner Richard , Norris David G. , Alfke Karsten , Mehdorn H. Maximilian , Jansen Olav
Published: April 2005

A new technique for selective spin labeling of individual arteries is presented. It is based on continuous arterial spin labeling (CASL) with an amplitude‐modulated control experiment. Precessionary motion of the labeling gradient about the axis of the artery, combined with an appropriate frequency modulation of the labeling RF pulse, restricts the adiabatic inversion to the desired artery. In phantom studies, it was found that the level of selectivity could be controlled by the sequence parameters, and that the achievable labeling efficiency was at a level of ∼80% compared to a regular, nonselective CASL experiment. In a volunteer study we acquired high‐quality images of the perfusion territories of the internal carotid artery (ICA), the basilar artery (BA), the middle cerebral artery (MCA), and both anterior cerebral arteries (ACAs). The results show the method's flexibility for different geometries and flow velocities. Potential applications include perfusion territory imaging of smaller cerebral arteries, and selective angiography techniques. Magn Reson Med 53:1006–1012, 2005. © 2005 Wiley‐Liss, Inc.
Fabrication of buried waveguides and nanocrystals in Er3+‐doped oxyfluoride glass
Authors: Tikhomirov V. K. , Seddon A. B. , Koch J. , Wandt D. , Chichkov B. N.
Published: April 2005

We report on direct writing of three‐dimensional structures within the bulk of the Er3+‐doped oxyfluoride precursor glass using tightly focused femtosecond Ti‐sapphire laser pulses at 800 nm wavelength. Buried 1 µm diameter channel and spherical waveguides and three‐dimensional periodic arrays of 1 µm diameter dots have been fabricated. In the latter case, the dot could be written with a single 25 fs laser pulse. When the laser pulse energy exceeded 10 µJ/pulse/µm2, the writing resulted in nano‐ceraming of the precursor glass and creation of about 2 to 3 nm diameter Er3+‐doped fluoride nanocrystals within the written dots/waveguides, as confirmed by a characteristic change in shape of the 1.5 µm photoluminescence band of the Er3+ ions. The diameter of the buried dots/wave‐guides, and the photoinduced change of their refractive index, can be varied by changing the number of femtosecond laser pulses, the beam waist diameter, and/or laser intensity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structures and spectra for triepoxides of fullerene C78O3
Authors: Teng Qiwen , Wu Shi
Published: April 2005

The equilibrium structures and relative stabilities of the possible 21 lower‐energy isomers for C78O3 based on C78 (C2v) were studied by intermediate neglect of differential overlap (INDO) calculations. It was indicated that the most stable geometry is 28,29,30,31,52,53‐C78O3, where three oxygen atoms are added to the same hexagon passed by the longest axis of C78 (C2v) and epoxide structures are formed. Electronic spectra of C78O3 isomers were investigated based on the optimized geometries. The blue shift of the absorptions for 28,29,30,31,52,53‐C78O3 compared with that of C78 (C2v) was rationalized and nature of transition of the peaks discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Seasonal and spatial variations in major and trace elements in a regulated boreal river (Esse River) affected by acid sulphate soils
Authors: Roos Marcus , Åström Mats
Published: April 2005

In coastal areas of Finland, extensive artificial drainage of Holocene sulphide‐bearing marine and lacustrine sediments has resulted in development of acid sulphate (AS) soils (pH 2.5–4.5) over an estimated area of approximately 3000 km2. During heavy rains and snow melting, these soils are flushed resulting in discharge of acidic and metal‐rich waters that strongly affect small streams. However, the total and precise effects in the important and large rivers are not well understood. In this study, the impact of AS soil occurrence and hydrological changes on water quality was determined in an important regulated boreal river (Esse River) having a catchment area of 2054 km2 partially covered with AS soil (39 km2). Water samples, collected at five sites along the river during four carefully selected events, were analysed for pH, total organic carbon, conductivity and the following elements/anions: Al, Ba, Br, Ca, Cd, Cl−, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, NO, Rb, Sc, Si, SO, Sr, Th, Y and Zn. There is a clear spatial correlation between AS soil occurrence and elevated element concentrations in the river water, especially when the conditions change from dry/warm (summer) to wet/cool (autumn). During the rains in autumn these soils are extensively flushed and concentrations of Co, La, Zn, Y, Mn and Al are increased between three and nine times towards the outlet. The buffering capacity of the river was, however, high enough to prevent a detrimental drop in pH. Another intriguing feature is substantially elevated concentrations of several potentially toxic metals (Cr, Cd, Cu) in the middle reaches in winter when the river is ice‐covered. Since no external source for this was found, we suggest an internal source operating by an as yet unknown mechanism. During baseflow in summer, the concentrations of several solutes reach minimum concentrations. Copyright © 2005 John Wiley & Sons, Ltd.
Comparative analysis of glacial and nival streamflow regimes with implications for lotic habitat quantity and fish species richness
Authors: Fleming Sean W.
Published: April 2005

Growing interest in the differential responses of glacial and nival rivers to climatic forcing, and in ecological distinctions between the two streamflow regimes, suggests the need for a better comparative understanding of how the annual hydrologic cycle differs with presence or absence of catchment glacial cover. In this study, timing and magnitude characteristics of the average annual hydrographs of five glacierized and four nival catchments in the southwestern Canadian subarctic are empirically identified and compared. Likely effects upon fish habitat are qualitatively assessed, and net fisheries potential is tentatively investigated using taxa richness data. The chief hydrological conclusions at P < 0.05 using Kolmogorov–Smirnov and empirical orthogonal function analyses are: (1) catchment glacial cover results in freshets that are longer, larger, and peak later than those experienced by the nival regime; (2) the winter baseflows of glacial rivers are also much higher on a unit‐catchment‐area basis; and (3) basin scale and degree of catchment glacial cover are of comparable importance in determining the magnitude of the annual hydrologic cycle. These differences arise from the greater availability, both in volume and over time, of meltwater in glacial catchments, which in part reflects the consistently negative alpine glacial mass balances observed both in the present study area and globally under historical climatic warming. Such regime distinctions result in increased spawning season and winter aquatic habitat availability, which may in turn offset negative habitat characteristics previously identified for glacial river ecosystems. While previous studies have suggested that glacial influences tend to decrease macroinvertebrate diversity and increase salmon populations, preliminary analysis of available fish species presence/absence data from the current study area tentatively appears to suggest similar or, perhaps, slightly higher fish taxa richness relative to nival streams; in all three cases, however, catchment lake cover may play a key hydroecological modifying role. The results strongly confirm and extend existing understanding of glacial–nival regime differences with respect to both streamflow and fisheries ecology, and raise new questions for future research. Copyright © 2005 John Wiley & Sons, Ltd.
Topical therapy for control of bacteria in the burn wound
Authors: Moncrief John A.
Published: April 2005

The concept of burn wound sepsis and the demonstration of the avascular nature of the burn wound paved the way for the development of effective antibacterial therapy of the burn wound. Many agents have been tried, but the most effective are those with a broad spectrum of antibacterial activity, lack of developing resistance, low toxicity, and active penetration of the wound. The resultant lowering of mortality and improvement in patient care have dramatically altered the prognosis of burn injury. The primary drugs in use today, their advantages and limitations, and the pathophysiology of the burn wound and burn wound sepsis are presented.
Closure of the Burn Wound
Authors: Sørensen Bent
Published: April 2005

Closure of the burn wound is the ultimate goal of treatment of burns. Closure can be achieved by spontaneous epithelialization or by grafting. Based on analyses of our series from the Burns Unit in Copenhagen from 1962–1971 (2,460 patients with acute burns) and from 1972–1975 (660 patients with acute burns), the exposure method of burn wound treatment produced the best results in cases of partial‐thickness burns, and this same method usually gave the best results in cases of deep burns seen up to 14 days postburn. Furthermore, our studies show that surgical excision is permissible at the earliest possible time after the burn accident (during the shock phase) in both small and very extensive burns. In cases of deep partial‐thickness burns, the cosmetically best results are achieved by tangential excision. The question as to when surgical intervention should take place, whether acutely in the shock phase or 14 days postburn, so as to yield the best results in terms of lowest mortality and morbidity, and best cosmetic results, cannot be answered on the basis of our series at this moment. In order to solve this important problem, we have set up a randomized, controlled trial which started on May 1, 1976.
Burns in childhood
Authors: Clarke A. Murray
Published: April 2005

The treatment of the very common and very serious problem of burning accidents in children is discussed with special reference to differences which exist compared with adults. The problems of assessment and resuscitation and the importance of early skin coverage in lowering mortality, reducing morbidity, and providing a better cosmetic result are stated. The historical events which have led to the most important single factor in the care of the burned child, the control of infection, are also discussed. New developments which have taken place to diminish scars and to improve their appearance and to avoid deformities are outlined, together with new attitudes which are adopted towards the patient and his family in order to restore him to society as unscathed as possible.
Metabolic changes following thermal injury
Authors: Arturson M. Gösta S.
Published: April 2005

Patients with extensive thermal injuries have a tremendous, long‐lasting increase in transcutaneous heat loss by increased evaporation, radiation, and convection. Their ability to regulate skin temperature and heat loss is limited, and the core‐skin insulation is inadequate. The corresponding posttraumatic metabolic response is a massive catabolic drive revealed as insulin insufficiency and increased release of catecholamines and glucagon. This stimulates lipolysis, proteolysis, substrate flow to the liver, and gluconeogenesis of amino acids. The increased heat production is related to an endogenous reset in metabolic activity and is further influenced by environmental conditions. Extensively burned patients cannot overcome the cold stress to which they are exposed by an increased functional heat insulation or by tolerating decreasing body temperature without reacting with a costly increase in heat production and without shivering. If the burn patients are permitted to control the heat supply from infrared heaters until they feel comfortable and all kinds of external environmental disturbances are eliminated, it is possible to reduce their metabolic rate to the normal value for the actual core temperature. The daily caloric requirements can be estimated and, in patients receiving a combined parenteral‐enteral dietary program and infrared heat, weight loss can be entirely avoided. Infrared radiation is a practical and inexpensive way of distributing energy from the environment to the patient, suitable also in disaster situations. The ambient air temperature can be kept comfortable with respect to the patient's airways and to the nursing staff.
Nutritional support of burn patients
Authors: Curreri P. William
Published: April 2005

Major thermal injury is characterized by a hypermetabolic response. Failure to provide burn patients with sufficient exogenous caloric and nitrogen intake results in pronounced weight loss, impaired wound healing, decreased host resistance to infection, and cellular dysfunction. Nutritional therapy should be directed at environmental control, prevention of infection, early wound closure, progressive physical activity, and the provision of sufficient exogenous calories and nitrogen to prevent unnecessary catabolic sequelae. During the past 10 years, new methods have emerged for providing better nutrition to severely burned patients. As a result, morbid complications of prolonged catabolism have been significantly reduced, and survival of patients with major thermal injury has been markedly enhanced.
A morphometric study of the effects of bile on the G cells of the antral mucosa of the dog
Authors: Oliveira Manuel C. , Azevedo Isabel
Published: April 2005

Gastrin cells of the antral mucosa of the dog were studied with electron microscopy and morphometric techniques before and after 1 hour of stimulation with bile. Control cells exhibited specific gastrin granules with a very electron‐dense core and some granules containing few or no secretory product. After 1 hour of bile stimulation, the volume density of the granular population was not different from the control, but the number of granules increased, their mean dimensions decreased, and the amount of secretory product was also significantly decreased. It is concluded that bile is an effective stimulus of gastrin secretion. Gastrin is released into the cytoplasm and there is some delay in the utilization of the granular membranes, so that an increase in the number of granules after continuous stimulation was observed. Under these conditions the mean diameter of the granular population is smaller than in control cells probably because there is a newly formed granular population which releases its secretory content under continuous stimulation before attaining the usual dimensions.
Evaluation of “Alkaline” reflux esophagitis after total gastrectomy in Henley and Roux‐en‐Y reconstructive procedures
Authors: Tonelli Francesco , Corazziari Enrico , Spinelli Francesco
Published: April 2005

The occurrence of reflux esophagitis was evaluated in 2 groups of patients who had undergone total gastrectomy. In group 1 (4 patients) gastrointestinal continuity was restored by Henley's method of esophagojejunoduodenostomy, and in group 2 (4 patients) reconstruction was accomplished by Roux‐en‐Y esophagojejunostomy. Cineradiography, intraesophageal pH measurements, esophagoscopy, esophageal biopsies, and study of intestinal motility were performed. Alkaline esophageal reflux was observed only in group 2, and a high frequency of esophageal symptoms and esophagitis were found in this group. These results can be correlated with the different motor behavior in the jejunum used for reconstruction, occurring in the 2 groups of patients.
Phalloarteriography in the diagnosis of erectile impotence
Authors: Michal V. , Pospíchal J.
Published: April 2005

An angiographic method has been developed for x‐ray visualization of the arteries supplying the cavernous bodies of the penis, namely, the internal iliac, internal pudendal, and penile artery and its branches (dorsal, deep, and bulbocavernous arteries). Under normal conditions the technique makes pulsations in both dorsal penile arteries palpable, and the flow rate of fluid into the cavernous bodies necessary to produce and maintain erection can be determined. The principle of the method involves artificial passive erection or semierection, during which we perform selective or semiselective arteriography of the bed supplied by the internal iliac artery, or retrograde arteriography by puncture of the dorsal artery of the penis.

Thirty males complaining of more than 1 year of impotence (including 12 diabetics) were investigated, 29 by our standard technique and 1 by translumbar pelvic arteriography with retrograde arteriography of the dorsal penile artery. All patients showed severe stenosis or obliteration of the vessels supplying the cavernous bodies. There was agreement between absence of pulsation in the dorsal penile arteries and the angiographic findings. Flow rates necessary to produce erection varied from 45 to 160 ml/min, with a mean of 90 ml/min. For controls, angiographic studies were performed in 4 men with clearly psychogenic impotence, all of whom were found to have normal‐appearing arteries supplying the cavernous bodies.

On the basis of these findings and previously reported histological investigations, we believe that most impotence is the symptomatic and functional result of arterial disease. The arteriographic technique described allows a precise anatomical diagnosis to be made, and can indicate surgical and microsurgical correction.
An experimental study of parietal cell vagotomy with further graduated denervation of the antrum
Authors: Boné Jørgen , Høst Viggo , Brandsborg Ole , Brandsborg Margrethe , Mikkelsen Kirsten , Amdrup Erik
Published: April 2005

In 4 groups of Heidenhain pouch (HP) dogs, the following operations were performed: (a) parietal cell vagotomy (PCV), (b) PCV with denervation of the proximal 2 cm of the antrum, (c) PCV with denervation of the proximal 4 cm of the antrum, and (d) PCV with denervation of the proximal 8 cm of the antrum. No significant differences in gastric emptying time, serum gastrin concentration, or HP acid secretion could be demonstrated between PCV and PCV with 2 cm denervation of the antrum. After 4 and 8 cm antral denervation, gastric stasis occurred, with significant increase in serum gastrin concentration and/or HP acid secretion. The study indicates that in dogs, preservation of the main terminal branches of the nerve of Latarjet is necessary to avoid severe disturbances in gastric emptying and motility.
Identification of bacteria in the bile by duodenal aspiration
Authors: Keighley M. R. B. , Burdon D. W.
Published: April 2005

Duodenal aspirates were collected after cholecystokinin administration in 47 patients before biliary surgery. Viable counts of bacteria in the duodenum were compared with operative bile cultures. In 30 patients with sterile bile, the duodenal fluid frequently contained small numbers of oropharyngeal commensals, but bacterial colony counts were > 105 organisms/ml in only 5 patients (17%). In 17 patients with biliary sepsis, duodenal colony counts were > 105 in 15 (88%). Provided that the total number of organisms in the duodenum was > 105, the presence of bacteria in the bile was accurately detected in 85% of patients and the type of bacteria identified in 77% of patients.
Abies population dynamics simulated using a functional–structural tree model
Authors: Kubo Takuya , Kohyama Takashi
Published: April 2005

A functional–structural model, PipeTree, based on Abies population data has been developed to reveal the interactions among processes at physiological, individual and population scales. Using field measurements obtained in a comprehensive series of research studies on subalpine Abies forest stands on Mt. Shimagare during the 1950s to 1980s, we designed the structural components and physiological process models for PipeTree. The results of the PipeTree simulation support the feasibility of using a functional–structural tree model to evaluate ecosystem performance at the stand level. PipeTree generates patterns similar to those in real subalpine forests, such as diameter–height relationships and time changes in basal area. After demonstrating the validity of the dynamics of a PipeTree population, we applied a sensitivity analysis under a productivity‐enhanced environment in which the maximum photosynthetic rate (Pmax) of PipeTree foliage was increased by 50% (caused, for example, by CO2 enrichment). The results of Pmax enhancement simulation show that the 50% increase in Pmax doubles the net primary production (NPP) in the PipeTree stand. These results suggest the importance of canopy structure in evaluating the function of terrestrial ecosystems.
Association of personality and work conditions with depressive symptoms
Authors: Jurado Dolores , Gurpegui Manuel , Moreno Obdulia , Fernández M. Carmen , Luna Juan D. , Gálvez Ramón
Published: April 2005

Background

Previous studies have found a relationship between job-related stress and depressive symptoms in different occupational groups, and that personality may modify the risk of developing depressive symptoms. We aimed to examine the association of personality and other individual and work conditions with depressive symptoms.

Methods

A sample of 498 teachers answered a questionnaire concerning individual and work characteristics, some job-related perceptions, and the wish to change jobs. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression scale (CES-D) and personality was measured by the Temperament and Character Inventory (TCI-125).

Results

Depressive symptoms were associated with female gender, age, low job satisfaction, high job stress, the wish to change jobs, working at a public school, and with higher scores on harm avoidance and novelty seeking and lower scores on self-directedness.

Conclusions

Our results underline the influence of personality traits on the development of depressive symptoms independently of other individual characteristics and the occupational context.
Current mental health in women with childhood sexual abuse who had outpatient psychotherapy
Authors: Peleikis Dawn E. , Mykletun Arnstein , Dahl Alv A.
Published: April 2005

Purpose

This study from Norway examines mental health status of women with child sexual abuse (CSA) who formerly had outpatient psychotherapy for anxiety disorders and/or depression. The relative contributions of CSA and other family background risk factors (FBRF) to aspects of mental health status are also explored.

Subjects

At a mean of 5.1 years after outpatient psychotherapy, 56 female outpatients with CSA and 56 without CSA were personally examined by an independent female psychiatrist. Systematic information about current mental health and functioning was collected by structured interview and questionnaires.

Results

Among women with CSA 95% had a mental disorder, 50% had PTSD, and mean global assessment of functioning (GAF) score was 61.8 ± 10.6. In contrast, 70% of women without CSA had a mental disorder, 14% had PTSD, and mean GAF 71.2 + 8.5. GAF and trauma scale scores were mainly determined by CSA, while FBRF mainly influenced the global psychopathology and dissociation scores.

Discussion

We have little knowledge on the mental health status at long-term in women with CSA who had psychotherapy. This study found their mental status to be rather poor, and worse than that of women without CSA who had psychotherapy for the same disorders. From the broad spectrum of mental disorders associated with CSA, this study concerns only women treated as outpatients for anxiety disorders and/or non-psychotic depressions.

Conclusion

Women with CSA showed poor mental health at long-term follow-up after treatment. The fitness of the psychodynamic individual psychotherapy given, or to what extent treatment can remedy the consequences of such childhood adversities, is discussed.
A systematic review of the efficacy and safety of second generation antipsychotics in the treatment of mania
Authors: Jones R.M. , Thompson C. , Bitter I.
Published: April 2005

Second generation antipsychotic agents are increasingly used in the management of acute mania. A systematic review of the efficacy and safety of these agents, as both monotherapy and in combination with mood stabilisers, was performed to establish the evidence for their use. Randomised controlled trials (RCTs) were critically appraised in more detail than studies that presented lower levels of evidence such as case reports, case series and open label follow up studies. We found 11 RCTs reporting on patients treated with second generation antipsychotics for acute bipolar mania, of which three included randomisation between the second generation antipsychotic and placebo, and eight between a mood stabiliser combined with either the second generation antipsychotic or placebo. Data from non-randomised trials is also presented.
Chronic oesophageal foreign body in a cat
Authors: Augusto Monica , Kraijer Michiel , Pratschke Kathryn M.
Published: April 2005

An 11-year-old cat was presented with an approximately 2-month history of dysphagia, intermittent regurgitation and weight loss. An oesophageal foreign body was identified on plain radiographs, and an oesophagotomy was performed to remove a large V-shaped bone from the caudal cervical oesophagus. A gastrostomy feeding tube was placed to allow nutritional support postoperatively. Medical treatment for oesophagitis was initiated after surgery. No complications were encountered and the cat was discharged 4 days after surgery.
Vitamin D-dependent rickets type 2 with characteristic radiographic changes in a 4-month-old kitten
Authors: Tanner Emma , Langley-Hobbs Sorrel J.
Published: April 2005

This report describes the presenting signs, biochemical abnormalities, and radiographic changes in a 4-month-old kitten with vitamin D-dependent rickets type 2. Details of therapy are described and possible reasons for treatment failure are discussed.
Can user models be learned at all? Inherent problems in machine learning for user modelling
Authors: MÜLLER MARTIN E.
Published: April 2005

Machine learning seems to offer the solution to many problems in user modelling. However, one tends to run into similar problems each time one tries to apply out-of-the-box solutions to machine learning. This article closely relates the user modelling problem to the machine learning problem. It explicates some inherent dilemmas that are likely to be overlooked when applying machine learning algorithms in user modelling. Some examples illustrate how specific approaches deliver satisfying results and discuss underlying assumptions on the domain or how learned hypotheses relate to the requirements on the user model. Finally, some new or underestimated approaches offering promising perspectives in combined systems are discussed. The article concludes with a tentative ‘‘checklist” that one might like to consider when planning to apply machine learning to user modelling techniques.
Melanopsin (Opn4) positive cells in the cat retina are randomly distributed across the ganglion cell layer
Authors: SEMO MA'AYAN , LLAMOSAS MARTA MUÑOZ , FOSTER RUSSELL G. , JEFFERY GLEN
Published: April 2005

A rare type of rodent retinal ganglion cell expresses melanopsin (Opn4), the majority of which project to the suprachiasmatic nuclei. Many of these cells are directly light sensitive and appear to regulate the circadian system in the absence of rod and cone photoreceptors. However, the rodent retina contains no overt regions of specialization, and the different ganglion cell types are hard to distinguish. Consequently, attempts to distinguish the distribution of melanopsin ganglion cells in relation to regions of retinal specialization or subtype have proved problematic. Retinal cells with a common function tend to be regularly distributed. In this study, we isolate cat melanopsin and label melanopsin expressing cells usingin situhybridization. The labelled cells were all confined to the ganglion cell layer, their density was low, and their distribution was random. Melanopsin containing cells showed no clear center-to-periphery gradient in their distribution and were comprised of a relatively uniform cellular population.
Normal eye-specific patterning of retinal inputs to murine subcortical visual nuclei in the absence of brain-derived neurotrophic factor
Authors: LYCKMAN ALVIN W. , FAN GUOPING , RIOS MARIBEL , JAENISCH RUDOLF , SUR MRIGANKA
Published: April 2005

Brain-derived neurotrophic factor (BDNF) is a preferred ligand for a member of the tropomyosin-related receptor family, trkB. Activation of trkB is implicated in various activity-independent as well as activity-dependent growth processes in many developing and mature neural systems. In the subcortical visual system, where electrical activity has been implicated in normal development, both differential survival, as well as remodeling of axonal arbors, have been suggested to contribute to eye-specific segregation of retinal ganglion cell inputs. Here, we tested whether BDNF is required for eye-specific segregation of visual inputs to the lateral geniculate nucleus and the superior colliculus, and two other major subcortical target fields in mice. We report that eye-specific patterning is normal in two mutants that lack BDNF expression during the segregation period: a germ-line knockout for BDNF, and a conditional mutant in which BDNF expression is absent or greatly reduced in the central nervous system. We conclude that the availability of BDNF is not necessary for eye-specific segregation in subcortical visual nuclei.
Reciprocal inhibition of voltage-gated potassium currents (IK(V)) by activation of cannabinoid CB1and dopamine D1receptors in ON bipolar cells of goldfish retina
Authors: FAN SHIH-FANG , YAZULLA STEPHEN
Published: April 2005

Cannabinoid CB1receptor (viaGs) and dopamine D2receptor (viaGi/o) antagonistically modulate goldfish cone membrane currents. As ON bipolar cells have CB1and D1receptors, but not D2receptors, we focused on whether CB1receptor agonist and dopamine interact to modulate voltage-dependent outward membrane K+currentsIK(V)of the ON mixed rod/cone (Mb) bipolar cells. Whole-cell currents were recorded from Mb bipolar cells in goldfish retinal slices. Mb bipolar cells were identified by intracellular filling with Lucifer yellow. The bath solution was calcium-free and contained 1 mM cobalt to block indirect calcium-dependent effects. Dopamine (10 μM) consistently increasedIK(V)by a factor of 1.57 ± 0.12 (S.E.M.,n= 15). A CB receptor agonist, WIN 55212-2 (0.25–1 μM), had no effect, but 4 μM WIN 55212-2 suppressedIK(V)by 60%. IfIK(V)was first increased by 10 μM dopamine, application of WIN 55212-2 (0.25–1 μM) reversibly blocked the effect of dopamine even though these concentrations of WIN 55212-2 had no effect of their own. If WIN 55212-2 was applied first and dopamine (10 μM) was added to the WIN-containing solution, 0.1 μM WIN 55212-2 blocked the effect of dopamine. All effects of WIN 55212-2 were blocked by coapplication of SR 141716A (CB1antagonist) and pretreatment with pertussis toxin (blocker of Gi/o) indicating actionviaCB1receptor activation of G protein Gi/o. Coactivation of CB1and D1receptors on Mb bipolar cells produces reciprocal effects onIK(V). The CB1-evoked suppression ofIK(V)is mediated by G protein Gi/o, whereas the D1-evoked enhancement is mediated by G protein Gs. As dopamine is a retinal “light” signal, these data support our notion that endocannabinoids function as a “dark” signal, interacting with dopamine to set retinal sensitivity.
Simulation analysis of receptive-field size of retinal horizontal cells by ionic current model
Authors: AOYAMA TOSHIHIRO , KAMIYAMA YOSHIMI , USUI SHIRO
Published: April 2005

The size of the receptive field of retinal horizontal cells changes with the state of dark/light adaptation. We have used a mathematical model to determine how changes in the membrane conductance affect the receptive-field properties of horizontal cells. We first modeled the nonlinear membrane properties of horizontal cells based on ionic current mechanisms. The dissociated horizontal cell model reproduced the voltage–current (V–I) relationships for various extracellular glutamate concentrations measured in electrophysiological studies. Second, a network horizontal cell model was also described, and it reproduced theV–Irelationship observedin vivo. The network model showed a bell-shaped relationship between the receptive-field size and constant glutamate concentration. The simulated results suggest that the calcium current is a candidate for the bell-shaped length constant relationship.
The direction-selective contrast response of area 18 neurons is different for first- and second-order motion
Authors: LEDGEWAY TIMOTHY , ZHAN CHANG'AN , JOHNSON AARON P. , SONG YUNING , BAKER CURTIS L.
Published: April 2005

Cortical neurons selective for the direction of motion often exhibit some limited response to motion in their nonpreferred directions. Here we examine the dependence of neuronal direction selectivity on stimulus contrast, both for first-order (luminance-modulated, sine-wave grating) and second-order (contrast-modulated envelope) stimuli. We measured responses from single neurons in area 18 of cat visual cortex to both kinds of moving stimuli over a wide range of contrasts (1.25–80%). Direction-selective contrast response functions (CRFs) were calculated as the preferred-minus-null difference in average firing frequency as a function of contrast. We also applied receiver operating characteristic analysis to our CRF data to obtain neurometric functions characterizing the potential ability of each neuron to discriminate motion direction at each contrast level tested. CRFs for sine-wave gratings were usually monotonic; however, a substantial minority of neurons (35%) exhibited nonmonotonic CRFs (such that the degree of direction selectivity decreased with increasing contrast). The underlying preferred and nonpreferred direction CRFs were diverse, often having different shapes in a given neuron. Neurometric functions for direction discrimination showed a similar degree of heterogeneity, including instances of nonmonotonicity. For contrast-modulated stimuli, however, CRFs for either carrier or envelope contrast were always monotonic. In a given neuron, neurometric thresholds were typically much higher for second- than for first-order stimuli. These results demonstrate that the degree of a cell's direction selectivity depends on the contrast at which it is measured, and therefore is not a characteristic parameter of a neuron. In general, contrast response functions for first-order stimuli were very heterogeneous in shape and sensitivity, while those for second-order stimuli showed less sensitivity and were quite stereotyped in shape.
Superimposed maps of the monocular visual fields in the caudolateral
optic tectum in the frog, Rana pipiens
Authors: WINKOWSKI DANIEL E. , GRUBERG EDWARD R.
Published: April 2005

The superficial layers of the frog optic tectum receive a projection
from the contralateral eye that forms a point-to-point map of the visual
field. The monocular part of the visual field of the contralateral eye is
represented in the caudolateral region of the tectum while the binocular
part of the visual field is represented in the rostromedial tectum. Within
the representation of the binocular field (rostromedial tectum), the maps
of visual space from each eye are aligned. The tectal representation of
the binocular visual field of the ipsilateral eye is mediated through a
crossed projection from the midbrain nucleus isthmi. This isthmotectal
projection also terminates in the caudolateral region of the optic tectum,
yet there has been no indication that it forms a functional connection. By
extracellular recording in intermediate layer 7 of the caudolateral
tectum, we have discovered electrical activity driven by visual
stimulation in the monocular visual field of the ipsilateral eye. The
units driven from the ipsilateral eye burst upon initial presentation of
the stimulus. At individual layer 7 recording sites in the caudolateral
tectum, the multiunit receptive field evoked from the ipsilateral eye is
located at the mirror image spatial location to the multiunit receptive
field driven by the contralateral eye. Thus, as revealed
electrophysiologically, there are superimposed topographic maps of the
monocular visual fields in the caudolateral tectum. The ipsilateral eye
monocular visual field representation can be abolished by electrolytic
ablation of contralateral nucleus isthmi.
Risk Attitudes and Behavior Among Norwegian Adolescents
Authors: Iversen Hilde , Rundmo Torbjørn , Klempe Hroar
Published: April 2005

Abstract. The core aim of the present study is to compare the effects of a safety campaign and a behavior modification program on traffic safety. As is the case in community-based health promotion, the present study's approach of the attitude campaign was based on active participation of the group of recipients. One of the reasons why many attitude campaigns conducted previously have failed may be that they have been society-based public health programs. Both the interventions were carried out simultaneously among students aged 18-19 years in two Norwegian high schools (n = 342). At the first high school the intervention was behavior modification, at the second school a community-based attitude campaign was carried out. Baseline and posttest data on attitudes toward traffic safety and self-reported risk behavior were collected. The results showed that there was a significant total effect of the interventions although the effect depended on the type of intervention. There were significant differences in attitude and behavior only in the sample where the attitude campaign was carried out and no significant changes were found in the group of recipients of behavior modification.
The Controversy over Null Hypothesis Significance Testing Revisited
Authors: Balluerka Nekane , Gómez Juana , Hidalgo Dolores
Published: April 2005

Abstract. Null hypothesis significance testing (NHST) is one of the most widely used methods for testing hypotheses in psychological research. However, it has remained shrouded in controversy throughout the almost seventy years of its existence. The present article reviews both the main criticisms of the method as well as the alternatives which have been put forward to complement or replace it. It focuses basically on those alternatives whose use is recommended by the Task Force on Statistical Inference (TFSI) of the APA ( Wilkinson and TFSI, 1999 ) in the interests of improving the working methods of researchers with respect to statistical analysis and data interpretation. In addition, the arguments used to reject each of the criticisms levelled against NHST are reviewed and the main problems with each of the alternatives are pointed out. It is concluded that rigorous research activity requires use of NHST in the appropriate context, the complementary use of other methods which provide information about aspects not addressed by NHST, and adherence to a series of recommendations which promote its rational use in psychological research.
Control of air‐sea CO2 disequilibria in the subtropical NE Atlantic by planktonic metabolism under the ocean skin
Authors: Calleja María Ll. , Duarte Carlos M. , Navarro Nuria , Agustí Susana
Published: April 2005

The air‐sea CO2 gradient at the subtropical NE Atlantic was strongly dependent on the metabolism of the planktonic community within the top cms, but independent of that of the communities deeper in the water column. Gross primary production (GPP) and community respiration (R) of the planktonic community within the top cms exceeded those of the communities deeper in the water column by >10‐fold and >7 fold, respectively. Net autotrophic metabolism (GPP > R) at the top cms of the water column in some stations drove CO2 uptake by creating a CO2 deficit at the ocean surface, while net heterotrophic metabolism (GPP < R) at the top cms of the water column in other stations resulted in strong CO2 supersaturation, driving CO2 emissions. These results suggest a strong control of the air‐sea pCO2 anomaly by intense biological processes.
Observations of persistent Leonid meteor trails: 4. Buoyant rise/vortex formation as mechanism for creation of parallel meteor train pairs
Authors: Zinn John , Drummond Jack
Published: April 2005

In this paper we present numerical computations designed to demonstrate effects associated with the buoyant rise of persistent trails produced by large Leonid meteors in cases where the meteor velocity vector has a large horizontal component. We model the meteor trail as a hot cylindrical volume in an equilibrium atmosphere. The computed results show the hot cylinder first expanding radially and then rising because of buoyancy, while evolving into a pair of counterrotating linear vortices. These line vortex phenomena are offered as an explanation for the otherwise mysterious parallel pairs of trails that are often observed. We also show some high‐resolution images of double meteor trails observed during the high Leonid meteor activity of 1998–2002. For the case of the Diamond Ring event we compare computed and measured luminosity profiles for the sodium 589 nm emission and for the red–near IR O2 atmospheric band (O2(b1Σg+) – O2(X3Σg−)) emission.
Relation between tidal damping and wave celerity in estuaries
Authors: Savenije Hubert H. G. , Veling Ed J. M.
Published: April 2005

Observations in estuaries indicate that an amplified tidal wave moves considerably faster than is indicated by the classical equation for wave propagation. Similarly, the celerity of propagation is lower if the tidal wave is damped. This phenomenon is clearly observed in the Schelde estuary (located in the Netherlands and Belgium) and in the Incomati estuary in Mozambique. In the Incomati, the tidal wave is damped throughout, whereas in the Schelde the tidal range increases from the mouth until the city of Antwerp, after which it decreases until Gent. This paper derives a new analytical expression for the celerity of the tidal wave that takes into account the effect of tidal damping, as an expansion of the classical equation for tidal wave propagation. In the new equation the phase lag between high water and high water slack plays a crucial role. It is one of the main parameters determining tidal wave propagation in alluvial estuaries. The equation is successfully applied to observations in the Schelde and the Incomati.
Inter‐ and intra‐annual analysis of the salinity and temperature evolution in the Galician Rías Baixas–ocean boundary (northwest Spain)
Authors: Alvarez Ines , deCastro Maite , Gomez‐Gesteira Moncho , Prego Ricardo
Published: April 2005

The inter‐ and intra‐annual evolution of temperature and salinity has been analyzed in the Rías Baixas–ocean boundary. Each ría (Vigo, Pontevedra, and Arousa) is connected to the shelf by two entrances separated by islands. Samples were taken weekly at both mouths from October 1997 to October 2002. All rías are observed to share some common features: thermal inversion from November to February, intense upwelling events from April to September (observed in about 40% of the bottom measurement at the southern mouths), and the input of a warm water mass in October. The Rías of Vigo and Pontevedra behave in a similar way, even quantitatively, and they differ slightly from the Ría of Arousa. This difference is especially important at the northern mouth of Arousa, where water is fresher in winter and upwelling events are less frequent in summer. These differences are mainly due to the slightly different orientation of the Ría of Arousa compared to the rest of the rías, the higher river discharge in this estuary, and the shallowness of its mouth.
An observational study of soil moisture effects on wind erosion at a gobi site in the Taklimakan Desert
Authors: Ishizuka Masahide , Mikami Masao , Yamada Yutaka , Zeng Fanjiang , Gao Weidong
Published: April 2005

The measurements at a gobi site suggest that (1) saltation mass flux q(z) is particle size and soil moisture‐dependent and (2) a simple relationship exists between q and wind speed u and threshold wind speed ut(θ). The ut(θ) in wet conditions (θ = 0.009 m3 m−3) was estimated to be 9.5 m s−1 at a height of 3.8 m. This value is 1.27 times larger than that in dry condition, which corresponds to Fécan et al.'s theoretical result. The (D) in wet conditions was smaller than that in dry conditions for the particles of 69–203 μm in diameter. However, for 38 and 54 μm particles, the did not change in both dry and wet conditions. Furthermore, long‐term monitoring showed that (1) the ground surface was dry during Aeolian Dust Experiment on Climate Impact (ADEC)‐Intensive Observation Period (IOP) 1 (8–21 April 2002), whereas it was wet during ADEC‐IOP2 (16–27 March 2003) because of snowfall at the beginning of March, and (2) the visibility frequently became worse during warm season when strong winds over the threshold wind speed blew and was dry.
Estimates of global multicomponent aerosol optical depth and direct radiative perturbation in the Laboratoire de Météorologie Dynamique general circulation model
Authors: Reddy M. Shekar , Boucher Olivier , Bellouin Nicolas , Schulz Michael , Balkanski Yves , Dufresne Jean‐Louis , Pham Mai
Published: April 2005

The global cycle of multicomponent aerosols including sulfate, black carbon (BC), organic matter (OM), mineral dust, and sea salt is simulated in the Laboratoire de Météorologie Dynamique general circulation model (LMDZT GCM). The seasonal open biomass burning emissions for simulation years 2000–2001 are scaled from climatological emissions in proportion to satellite detected fire counts. The emissions of dust and sea salt are parameterized online in the model. The comparison of model‐predicted monthly mean aerosol optical depth (AOD) at 500 nm with Aerosol Robotic Network (AERONET) shows good agreement with a correlation coefficient of 0.57(N = 1324) and 76% of data points falling within a factor of 2 deviation. The correlation coefficient for daily mean values drops to 0.49 (N = 23,680). The absorption AOD (τa at 670 nm) estimated in the model is poorly correlated with measurements (r = 0.27, N = 349). It is biased low by 24% as compared to AERONET. The model reproduces the prominent features in the monthly mean AOD retrievals from Moderate Resolution Imaging Spectroradiometer (MODIS). The agreement between the model and MODIS is better over source and outflow regions (i.e., within a factor of 2). There is an underestimation of the model by up to a factor of 3 to 5 over some remote oceans. The largest contribution to global annual average AOD (0.12 at 550 nm) is from sulfate (0.043 or 35%), followed by sea salt (0.027 or 23%), dust (0.026 or 22%), OM (0.021 or 17%), and BC (0.004 or 3%). The atmospheric aerosol absorption is predominantly contributed by BC and is about 3% of the total AOD. The globally and annually averaged shortwave (SW) direct aerosol radiative perturbation (DARP) in clear‐sky conditions is −2.17 Wm−2 and is about a factor of 2 larger than in all‐sky conditions (−1.04 Wm−2). The net DARP (SW + LW) by all aerosols is −1.46 and −0.59 Wm−2 in clear‐ and all‐sky conditions, respectively. Use of realistic, less absorbing in SW, optical properties for dust results in negative forcing over the dust‐dominated regions.
How might a statistical cloud scheme be coupled to a mass‐flux convection scheme?
Authors: Klein Stephen A. , Pincus Robert , Hannay Cécile , Xu Kuan‐Man
Published: April 2005

The coupling of statistical cloud schemes with mass‐flux convection schemes is addressed. Source terms representing the impact of convection are derived within the framework of prognostic equations for the width and asymmetry of the probability distribution function of total water mixing ratio. The accuracy of these source terms is quantified by examining output from a cloud‐resolving model simulation of deep convection. Practical suggestions for the inclusion of these source terms in large‐scale models are offered.