bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping gradual landscape‐scale floristic changes in Amazonian primary rain forests by combining ordination and remote sensing
Authors: Thessler Sirpa , Ruokolainen Kalle , Tuomisto Hanna , Tomppo Erkki 
Published: June 2005

ABSTRACTAim We present a new method to economically map gradual changes in plant species composition in lowland rain forests using field data and satellite images. Such a method will be a useful tool in planning the sustainable use and conservation of Amazonian rain forests.Location The study covered an area ofc.700 km2of primary rain forest in Amazonian Ecuador.Methods We field inventoried the species composition of pteridophytes and Melastomataceae in 340 inventory plots (5 m × 50 m), described the prevailing topography and analysed soil cation concentration and texture. We used non‐metric multidimensional scaling (NMDS) to summarize the floristic variation among the inventory plots in three ordination dimensions. The scores of the three ordination axes were predicted to non‐visited places using a Landsat TM (thematic mapper) satellite image and theknearest neighbours (knn) estimation method. To avoid extrapolation, we excluded from the analysis those pixel windows whose spectral values were not represented in the areas covered by field sampling. The accuracy of the predictions was evaluated by cross‐validation and by comparing the predictions based on spectrally nearest neighbours to the predictions based on random neighbours.Results The floristic gradients presented by NMDS ordination were interpretable in terms of topography, drainage and soil cation content. Thirteen percent of the cloud‐free pixels were excluded from theknn analysis to avoid extrapolation. The estimates of the floristic ordination scores based on spectrally nearest neighbours were always more accurate than estimates based on random neighbours.Main conclusions The presented method needs a relatively small input of work and resources, is mechanistic and produces maps that give relevant information on floristic variation over forest areas that are traditionally considered essentially homogeneous. Therefore, the method appears to have a great potential for use in mapping large areas of Amazonian rain forests.
Energy flux, body size and density in relation to bird species richness along an elevational gradient in Taiwan
Authors: Ding Tzung‐Su , Yuan Hsiao‐Wei , Geng Shu , Lin Yao‐Sung , Lee Pei‐Fen 
Published: June 2005

ABSTRACTAim  To examine the species richness of breeding birds along a local elevational gradient and to test the following assumptions of the energy limitation hypothesis: (1) the energy flux through birds is positively correlated with above‐ground net primary productivity, (2) bird density is positively correlated with total energy flux, and (3) bird species richness is positively correlated with bird density.Location  An elevational gradient from 1400 to 3700 m on Mt. Yushan, the highest mountain in Taiwan (23°28′30″ N, 120°54′00″ E), with a peak of 3952 m a.s.l.Methods  We established 50 sampling stations along the elevational gradient. From March to July 1992, we estimated the density of each bird species using the variable circular‐plot method. Above‐ground net primary productivity was modelled using monthly averages from weather data for the years 1961–90.Results  Bird species richness had a hump‐shaped relationship with elevation and with net primary productivity. Bird energy flux was positively correlated with net primary productivity and bird species richness was positively correlated with bird density. The relationship between bird density and energy flux was hump‐shaped, which does not support one assumption of the energy limitation hypothesis.Main conclusions  The results supported two essential assumptions of the energy limitation hypothesis. However, when energy availability exceeded a certain level, it could decrease species richness by increasing individual energy consumption, which reduced bird density. Thus, energy availability is a primary factor influencing bird species richness at this scale, but other factors, such as body size, could also play important roles.
Changes in the diversity structure of avian assemblages in North America
Authors: La Sorte Frank A. , Boecklen William J. 
Published: June 2005

AbstractAim  To determine the major patterns of change in avian diversity structure over space and time at a local resolution and continental extent in non‐urban areas in North America.Location  The contiguous United States and southern Canada.Methods  We used 1673 North American Breeding Bird Survey (BBS) routes containing 547 terrestrial and aquatic species to estimate four diversity components: species richness, individual abundance, taxonomic distinctness and species evenness. We implemented three levels of analysis to examine changes in diversity structure on a yearly basis from 1968 to 2003: (1) a canonical analysis of discriminance, (2) a univariate analysis across BBS routes, and (3) a univariate analysis at individual BBS routes. We estimated changes in similarity in species composition over time between 470,730 BBS route pairs. We also estimated the level of human activity at BBS routes using three spatial anthropogenic databases.Results  BBS routes were located in non‐urban areas in association with low nighttime light activity and moderately low human population densities. The analysis of diversity structure indicated the presence of two independent patterns: (1) a temporally consistent pattern defined by increasing species richness (12% increase from 1968 to 2003) associated with limited gains in taxonomic distinctness, and (2) an association between species abundance and evenness related to variability in abundance associated with the most abundant species. The similarity analysis indicated that BBS routes located closer to the Atlantic and the Pacific coasts of the United States experienced the strongest patterns of homogenization of species composition.Main conclusions  Our results suggest that avian diversity structure has changed at the local scale in non‐urban areas in North America. However, there was no evidence for a consistent continent‐wide pattern. Instead, the evidence pointed to the presence of regional factors influencing diversity patterns. This study provides a foundation for more detailed investigations of the spatiotemporal and taxonomic details of these general patterns.
The p38 mitogen‐activated protein kinase pathway negatively regulates Ca2+‐activated K+ channel trafficking in developing parasympathetic neurons
Authors: Chae Kwon‐Seok , Dryer Stuart E. 
Published: June 2005

AbstractThe trafficking of large‐conductance Ca2+‐activated K+ channels (KCa) in chick ciliary ganglion neurons is regulated by growth factors. Here we show that a canonical p38 cascade inhibits KCa trafficking in ciliary ganglion neurons. Two different p38 inhibitors (SB202190 or SB203580) or over‐expression of dominant‐negative forms of several components of the p38 cascade increased KCa in ciliary neurons. Inhibition of protein synthesis or Golgi processing had no effect on this phenomenon, suggesting that p38 is acting at a distal step of the trafficking pathway. Depolymerization of filamentous actin (F‐actin) increased functional expression of KCa, whereas stabilization of F‐actin inhibited the effect of SB202190 on KCa trafficking. SB202190 also caused an immunochemically detectable increase in KCa on the plasma membrane. Inhibition of p38 decreased the extent of cortical F‐actin in ciliary neurons. Macroscopic KCa is suppressed by transforming growth factor (TGF) β3. Application of TGFβ3 increased the phosphorylation of p38 in ciliary neurons and increased cortical F‐actin. Thus, the p38 signaling cascade endogenously suppresses development of functional KCa, in part by stabilizing an F‐actin barrier that prevents plasma membrane insertion of functional channel complexes. This cascade also appears to mediate inhibitory effects of TGFβ3 on the expression of KCa.
Peripheral injection of lipopolysaccharide enhances expression of inflammatory cytokines in murine locus coeruleus: possible role of increased norepinephrine turnover
Authors: Kaneko Yoko S. , Mori Keiji , Nakashima Akira , Sawada Makoto , Nagatsu Ikuko , Ota Akira 
Published: June 2005

AbstractCytokines and catecholamines are known to constitute a significant portion of the regulatory neuroimmune networks involved in maintaining homeostasis in the central nervous system (CNS). Although we have already reported an increase in norepinephrine (NE) turnover within the locus coeruleus (LC) at 2 and 4 h after the intraperitoneal (i.p.) injection of lipopolysaccharide (LPS), the implication of this increase remains unclear. In view of evidence that norepinephrine (NE) acts in an anti‐inflammatory manner by way of negatively regulating pro‐inflammatory cytokine expression, we examined the inflammatory cytokine expression levels in the LC of C3H/HeN mice (male, 8 weeks old) after an i.p. LPS injection. The mRNA expression levels of the genes encoding IL‐1β and TNF‐α within the LC increased during the first 2 h, and showed two peaks, the first at 4 h and the second lesser one at 15 h after the LPS injection. Microglia, which are one of the major cell types that produce pro‐inflammatory cytokines in the CNS, were isolated from mouse neonate brains in order to clarify more precisely the relationship between the changes in NE content and the up‐regulation of inflammatory cytokines in the LC. Simultaneous incubation of microglia with LPS and NE enhanced the expression of IL‐1β at both mRNA and protein levels, but reduced the mRNA and protein levels of TNF‐α. These data support the hypothesis that NE negatively regulates the expression of pro‐inflammatory cytokine expression, at least in the case of TNF‐α, which action could contribute to the observed anti‐inflammatory properties of NE. This report, based on the results of both in vivo and in vitro experiments, is the first to suggest a relationship between NE content and cytokine expression levels in the CNS.
Effect of chronic gestational treatment with caffeine or theophylline on Group I metabotropic glutamate receptors in maternal and fetal brain
Authors: León D. , Albasanz J. L. , Ruíz M. A. , Iglesias I. , Martín M. 
Published: June 2005

AbstractPregnant rats were treated throughout the gestational period with either caffeine or theophylline, and its effect on the metabotropic glutamate receptor (mGluRs) signal transduction pathway was studied in both maternal and fetal brain. In maternal brain, radioligand binding assays showed that chronic treatment with methylxanthines caused a significant decrease in the total number of mGluRs. This decrease was accompanied by an increase in receptor affinity. Immunodetection showed that mGluR1a and phospholipase C β1 (PLCβ1) were significantly decreased in response to chronic methylxanthine treatment, whereas αGq/11 was not affected. A loss was also detected of PLC stimulation mediated by (S)‐3,5‐dihydroxyphenylglycine (DHPG), a selective Group I mGluR agonist, suggesting desensitization of the mGluR/PLC pathway. In fetal brain, a loss in total mGluRs was observed in fetuses from mothers treated with caffeine or theophylline, without variation in receptor affinity. A decrease in mGluR1a, αGq/11 and PLCβ1 levels was also observed in response to treatment. However, changes detected in this immature tissue were not associated with variations in PLC activity. These results suggest that chronic caffeine or theophylline treatment down‐regulates several mGluR/PLC transduction pathway components in both maternal and fetal brain, causing a loss of receptor responsiveness only in maternal brain.
Developmental change in the calcium sensor for synaptic vesicle endocytosis in central nerve terminals
Authors: Smillie Karen J. , Evans Gareth J. O. , Cousin Michael A. 
Published: June 2005

AbstractSynaptic vesicle endocytosis is stimulated by calcium influx in mature central nerve terminals via activation of the calcium‐dependent protein phosphatase, calcineurin. However, in different neuronal preparations calcineurin activity is either inhibitory, stimulatory or irrelevant to the process. We addressed this inconsistency by investigating the requirement for calcineurin activity in synaptic vesicle endocytosis during development, using vesicle recycling assays in isolated nerve terminals. We show that endocytosis occurs independently of calcineurin activity in immature nerve terminals, and that a calcineurin requirement develops 2–4 weeks after birth. Calcineurin‐independent endocytosis is not due to the absence of calcineurin activity, since calcineurin is present in immature nerve terminals and its substrate, dynamin I, is dephosphorylated on depolarization. Calcineurin‐independent endocytosis is calcium‐dependent, since substitution of the divalent cation, barium, inhibits the process. Finally, we demonstrated that in primary neuronal cultures derived from neonatal rats, endocytosis that was initially calcineurin‐independent developed a calcineurin requirement on maturation in culture. Our data account for the apparent inconsistencies regarding the role of calcineurin in synaptic vesicle endocytosis, and we propose that an unidentified calcium sensor exists to couple calcium influx to endocytosis in immature nerve terminals.
Interactions between ρ and γ2 subunits of the GABA receptor
Authors: Pan Yi , Qian Haohua 
Published: June 2005

AbstractThe γ‐aminobutyric acid type C (GABAC) receptor is a ligand‐gated chloride channel with distinct physiological and pharmacological properties. Although the exact subunit composition of native GABAC receptors has yet to be firmly established, there is general agreement that GABA ρ subunits participate in their formation. Recent studies on white perch suggest that certain GABA ρ subunits can co‐assemble with the GABAA receptor γ2 subunit to form a heteromeric receptor with electrophysiological properties that correspond more closely to the native GABAC receptor on retinal neurons than any of the homomeric ρ receptors. In the present study we examined the interactions among various perch GABA ρ and γ2 subunits. When co‐expressed in Xenopus oocytes, the γ2 subunit co‐immunoprecipitated with Flag‐tagged perch ρ1Α, ρ1B, and ρ2B subunits, but not with the Flag‐tagged perch ρ2Α subunit. Immunocytochemical studies indicated that the membrane surface expression of the γ2 subunit was detected only when it was co‐expressed with perch ρ1Α, ρ1B, or ρ2B subunit, but not with the perch ρ2Α subunit or when expressed alone. In addition, co‐immunoprecipitation of perch ρ1B and γ2 subunits was also detected in protein samples of the teleost retina. Taken together, these findings suggest that a heteromeric ργ2 receptor could represent one form of GABAC receptor on retinal neurons.
Maternal zinc deficiency reduces NMDA receptor expression in neonatal rat brain, which persists into early adulthood
Authors: Chowanadisai Winyoo , Kelleher Shannon L. , Lönnerdal Bo 
Published: June 2005

AbstractPrenatal and early postnatal zinc deficiency impairs learning and memory and these deficits persist into adulthood. A key modulator in this process may be the NMDA receptor; however, effects of zinc deficiency on the regulation of NMDA receptor activity are not well understood. Female Sprague‐Dawley rats were fed diets containing 7 (zinc deficient, ZD), 10 (marginally zinc deficient, MZD) or 25 (control) mg Zn/g diet preconception through postnatal day (PN) 20, at which time pups were weaned onto their maternal or control diet. Regulation of NMDA receptor expression was examined at PN2, PN11, and PN65. At PN2, expression of whole brain NMDA receptor subunits NR1, NR2A, and NR2B was lower in pups from dams fed ZD and MZD compared to controls, as analyzed using relative RT–PCR and immunoblotting. At PN11, whole brain and hippocampi NR1, NR2A, NR2B and PSA‐NCAM (polysialic acid–neural cell adhesion molecule) expression and the number of PSA‐NCAM immunoreactive cells were lower in pups from dams fed ZD compared to controls. Whole brain brain‐derived neurotrophic factor (BDNF) and nerve growth factor (NGF) concentrations were lower in pups from dams fed ZD or both low zinc diets, respectively. Whole brain NR1 expression remained lower in previously zinc‐deficient rats at PN65. These data indicate potential mechanisms through which developmental zinc deficiency can impair learning and memory later in life.
Identification and characterization of a novel family of Drosophilaβ‐adrenergic‐like octopamine G‐protein coupled receptors
Authors: Maqueira Braudel , Chatwin Heather , Evans Peter D. 
Published: June 2005

AbstractInsect octopamine receptors carry out many functional roles traditionally associated with vertebrate adrenergic receptors. These include control of carbohydrate metabolism, modulation of muscular tension, modulation of sensory inputs and modulation of memory and learning. The activation of octopamine receptors mediating many of these actions leads to increases in the levels of cyclic AMP. However, to date none of the insect octopamine receptors that have been cloned have been convincingly shown to be capable of directly mediating selective and significant increases in cyclic AMP levels. Here we report on the identification and characterization of a novel, neuronally expressed family of three Drosophila G‐protein coupled receptors that are selectively coupled to increases in intracellular cyclic AMP levels by octopamine. This group of receptors, DmOctβ1R (CG6919), DmOctβ2R (CG6989) and DmOctβ3R (CG7078) shows homology to vertebrate β‐adrenergic receptors. When expressed in Chinese hamster ovary cells all three receptors show a strong preference for octopamine over tyramine for the accumulation of cyclic AMP but show unique pharmacological profiles when tested with a range of synthetic agonists and antagonists. Thus, the pharmacological profile of individual insect tissue responses to octopamine might vary with the combination and the degree of expression of the individual octopamine receptors present.
New trogons from the early Tertiary of Germany
Authors: MAYR GERALD 
Published: June 2005

A new trogon (Aves, Trogoniformes),Primotrogon?pumiliosp. nov., is described from the Middle Eocene (49 Ma) of Messel in Germany. It is the first articulated skeleton of an Eocene trogon, of which only very few fragmentary remains were hitherto known. It is also the earliest complete skeleton of a trogon, exceeding previous finds (Primotrogon wintersteiniMayr 1999) by at least 15 million years. An isolated wing of a trogon is further identified from the early Oligocene (about 30–34 Ma) of the fossil site Frauenweiler in Germany.Primotrogon?pumilioand all other sufficiently well‐preserved early Tertiary trogons appear to be stem group representatives of the Trogoniformes, corresponding with molecular clock data indicating a mid‐Tertiary origin of crown group Trogoniformes.
Comparative Study of Migraines in Relation to Their Duration of Evolution
Authors: Serratrice G. , Serbanesco E 
Published: June 2005

SYNOPSISThis transverse statistical study deals with a series of 412 patients with migraine ranging between less than one year and more than thirty years of evolution. The chronological and clinical characteristics and the therapeutic results vary with the duration of the condition. In long standing migraine, there are less typical migrainous characteristics (prodromes, hemicranias). Classic migraine has a shorter evolution than common migraine. Menopause seems to have an ameliorating effect on migraine. Whatever the duration of migraine neurotic conditions are the most common pathological previous history. Even in long‐standing migraine, the erget derivatives are the most efficient antimigrainous drugs.
Headache in the Elderly: An Evaluation of Risk Factors
Authors: Hale William E. , May Franklin E. , Marks Ronald G. , Moore Mary T. , Stewart Ronald B. 
Published: June 2005

SYNOPSISInformation on the prevalence of headache in an ambulatory elderly population was collected from 1,284 participants in a health screening program in Dunedin, Florida. Association between headache and possible risk factors including age, sex, reported symptoms and diseases, drug use, physical characteristics, and sleep patterns were studied. Eleven percent of women and 5 percent of men reported frequent headaches. There was no relationship between age and reported headache in this elderly population. The most commonly reported positions for headache were frontal (35.2 percent) and all over (29.7 percent). In women there was a significant correlation between headache and the total number of other diseases and symptoms reported (p<0.0001). However, in men, there was no such correlation. Numerous specific symptoms were found to be associated with headache in women including: temporary loss of vision, expressive aphasia, and feeling that others do not care. In men, headache was significantly correlated only with paroxysmal nocturnal dyspnea, feeling lonely, and feeling depressed, Subjects who slept less than seven hours a day reported a greater prevalence of headache (13.5 percent) than those who slept more than seven hours (8.1 percent) (p<0.01). There was no correlation of headache with systolic or diastolic blood pressure, coffee, alcohol or tobacco use, or the amount of time spent watching television. Elderly headache sufferers, in summary, often have other conditions coexisting with and/or contributing to the headaches. Some of these conditions may respond to psychological or medical intervention.
Psychological Distress, Comorbidities, and Health Behaviors among U.S. Adults with Seizures: Results from the 2002 National Health Interview Survey
Authors: Strine Tara W. , Kobau Rosemarie , Chapman Daniel P. , Thurman David J. , Price Patricia , Balluz Lina S. 
Published: June 2005

Summary:  Purpose: To examine the association of seizures with health‐related quality of life (HRQOL), physical and psychiatric comorbidities, and health behaviors. Methods: We analyzed data obtained from adults aged 18 years or older (n = 30,445) who participated in the 2002 National Health Interview Survey, an ongoing, computer‐assisted personal interview of the noninstitutionalized U.S. population. Results: An estimated 1.4% of adults 18 years or older reported being told by a health care professional that they had seizures. Persons with seizures were significantly more likely than those without seizures to report lower levels of education, higher levels of unemployment, pain, hypersomnia and insomnia, and psychological distress (e.g., feelings of sadness, nervousness, hopelessness, and worthlessness). In addition, they were significantly more likely to report insufficient leisure‐time physical activity as well as physical comorbidities such as cancer, arthritis, heart disease, stroke, asthma, severe headaches, lower back pain, and neck pain. Conclusions: Our findings suggest that it is advisable for health care professionals to assess psychiatric and physical comorbidities among patients with a history of seizures potentially to improve patient health outcomes. Furthermore, public health surveillance systems should include questions on seizures, epilepsy, and mental health to better examine associations among these disorders and to better identify populations meriting further assessment and intervention.