bluuebunny/crossref_metadata_2025_split huggingface dataset:
Net primary productivity mapped for Canada at 1‐km resolution
Authors: Liu J , Chen J. M. , Cihlar J. , Chen W. 
Published: March 2003

AbstractAim To map net primary productivity (NPP) over the Canadian landmass at 1‐km resolution.Location Canada.Methods A simulation model, the Boreal Ecosystem Productivity Simulator (BEPS), has been developed. The model uses a sunlit and shaded leaf separation strategy and a daily integration scheme in order to implement an instantaneous leaf‐level photosynthesis model over large areas. Two key driving variables, leaf area index (every 10 days) and land cover type (annual), are derived from satellite measurements of the Advanced Very High Resolution Radiometer (AVHRR). Other spatially explicit input data are also prepared, including daily meteorological data (radiation, precipitation, temperature, and humidity), available soil water holding capacity (AWC) and forest biomass. The model outputs are compared with ground plot data to ensure that no significant systematic biases are created.Results The simulation results show that Canada’s annual net primary production was 1.22 Gt C year−1 in 1994, 78% attributed to forests, mainly the boreal forest, without considering the contribution of the understorey. The NPP averaged over the entire landmass was ~140 g C m−2 year−1 in 1994. Geographically, NPP varied greatly among ecozones and provinces/territories. The seasonality of NPP is characterized by strong summer photosynthesis capacities and a short growing season in northern ecosystems.Conclusions This study is the first attempt to simulate Canada‐wide NPP with a process‐based model at 1‐km resolution and using a daily step. The statistics of NPP are therefore expected to be more accurate than previous analyses at coarser spatial or temporal resolutions. The use of remote sensing data makes such simulations possible. BEPS is capable of integrating the effects of climate, vegetation, and soil on plant growth at a regional scale. BEPS and its parameterization scheme and products can be a basis for future studies of the carbon cycle in mid‐high latitude ecosystems.
Latitudinal extent and natural history characteristics of birds in Nicaragua
Authors: Gillespie Thomas W. 
Published: March 2003

AbstractThis paper assesses the latitudinal extent of terrestrial breeding birds in Nicaragua. In particular, associations among latitudinal midpoint, body mass, and latitudinal extent are examined; significant differences between natural history characteristics (trophic guild, forest dependence, number of forest types) and latitudinal extent are identified; and a test is undertaken of Rapoport's rule for birds at the edge of their northern or southern range in Nicaragua. Birds in Nicaragua were classified into four categories based on latitudinal extent: birds generally restricted to Central America (20%); birds near the edge of their range within Nicaragua (34%); Neotropical birds (42%); and Pan‐American birds (4%). Latitudinal midpoint had a significant negative correlation with latitudinal extent over different taxonomic scales. Natural history characteristics of trophic guild, forest dependence and number of forest types can account for significant differences in species latitudinal extent. Carnivores had greater latitudinal extents than most other trophic guilds, non‐forest birds had greater latitudinal extents than birds that require patchy forest, and birds that occur in four or more forest types had greater latitudinal extents than birds restricted to one or two forest types. Contrary to Rapoport's rule, birds with a northern affinity or latitudinal midpoint north of Nicaragua had significantly smaller latitudinal extents than birds with a southern affinity or latitudinal midpoint south of Nicaragua. A comparison of natural history characteristics of birds with northern and southern affinities found no difference between trophic guild or forest dependence but a significant difference among the number of forest types used by forest birds. Birds with a southern affinity were restricted to fewer forest types than birds with a northern affinity.
Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro‐ecosystems of Mesoamerica
Authors: Gordon James E. , Barrance Adrian J. , Schreckenberg Kate 
Published: March 2003

ABSTRACTAim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found.
Identification of a new connexin gene GJA11 (Cx59) using degenerate PCR primers
Authors: Coucke Paul J. , Laer Lut Van , Meyers Johan , Hauwe Peter Van , Ottschytsch Natacha , Wauters Jan G. , Kelley Philip , Willems Patrick J. , Camp Guy Van 
Published: March 2003

AbstractIntroduction Connexins (Cx) comprise a family of homologous proteins that are involved in the intercellular exchange of ions and small metabolites between adjacent cells. So far, mutations in seven different connexins have been found in humans, each resulting in a genetic disease.Methods Based on the sequence alignment of known human Cx genes, we developed degenerate PCR primers that we anticipated would amplify members of the Cx gene family, in order to identify novel Cx genes.Results By subcloning and sequencing the PCR products, we identified a previously unidentified connexin gene that we named Cx59 (GJA11). Using FISH we localized the GJA11 gene to chromosome 1p34, and by the analysis of a YAC contig of this region, we mapped this gene within the linkage interval of an Indonesian family with autosomal dominant nonsyndromic hearing loss (ADNSHL). Because mutations in other connexins, namely GJB3 (Cx31) and GJB6 (Cx30), lead to similar forms of ADNSHL, GJA11 (Cx59) was a very strong candidate gene. Therefore, we performed mutation analysis of the coding region of GJA11 in patients of this Indonesian family, but no disease‐causing mutation was found.
Major discoveries on the dermal skeleton of fossil and Recent polypteriforms: a review
Authors: Daget Jacques , Gayet Mireille , Meunier François J , Sire Jean‐Yves 
Published: March 2003

AbstractFollowing the discovery of the first living polypterid, Polypterus bichir, in 1802, almost two centuries later we now know of 15 living species (including four subspecies), 14 belonging to the genus Polypterus and one to the genus Erpetoichthys (Calamoichthys) all inhabiting intertropical Africa. The polypterid fossil record was for a long time reduced to some scarce, disarticulated bones, mainly scales, found in various African deposits covering a wider area than the actual geographical distribution. With the discovery, on one hand, of polypterid scales, vertebrae, dermal bones of the cranium and dorsal spiny rays in South America and, on the other hand, of scales and numerous dorsal spiny rays in Niger and Sudan, and two articulated fossils in Morocco, the story of the polypteriforms has revealed some of its mysteries. The discovery of isopedine between dentine and bony basal plate in the scales of living and fossil polypterid species is considered a synapomorphy of the group, and has been an important aid in discriminating polypterid scales from other ganoid scales. A review of the main findings during the last 20 years is presented.
Diadromy, diversity and divergence: implications for speciation processes in fishes
Authors: McDowall R M 
Published: March 2003

Ghoti papers Ghoti aims to serve as a forum for stimulating and pertinent ideas. Ghoti publishes succinct commentary and opinion that addresses important areas in fish and fisheries science. Ghoti contributions will be innovative and have a perspective that may lead to fresh and productive insight of concepts, issues and research agendas. All Ghoti contributions will be selected by the editors and peer reviewed. Etymology of Ghoti George Bernard Shaw (1856–1950), polymath, playwright, Nobel prize winner and the most prolific letter writer in history, was an advocate of English spelling reform. He was reportedly fond of pointing out its absurdities by proving that ‘fish’ could be spelt ‘ghoti’. That is: ‘gh’ as in ‘rough’, ‘o’ as in ‘women’ and ‘ti’ as in palatial.AbstractDiadromous migrations can have what seem to be opposing roles in the processes of developing genetic diversity between populations of a species, in terms of morphological and behavioural divergence and speciation. On the one hand, diadromy promotes gene flow among populations, and thereby hinders development of genetic structuring within species and prevents speciation across a species’ broad range. On the other hand, diadromy fosters dispersion and the invasion of new habitats and, when accompanied by the establishment of landlocked/freshwater limited populations, promotes speciation. Examples of both processes can be observed across the diversity of diadromous fishes.
Cerebral blood flow velocity and perfusion in purulent meningitis: a comparative TCD and 99MTC‐HMPAO‐SPECT study
Authors: Haring H.‐P. , Kampfl A. , Grubwieser G. , Donnemiller E. , Pfausler B. , Schmutzhard E. 
Published: March 2003

In 15 patients (median age 33 years; range 17–74 years) suffering from acute pneumococcal (10 cases) and meningococcal (five cases) meningitis, cerebral blood flow velocity (CBFV) was measured in the M1– segment of the middle cerebral artery (MCA) by transcranial Doppler sonography, and cerebral perfusion changes were evaluated by 99m‐Tchexamethylpropylene amine oxime single photon emission computed tomography (HMPAO SPECT). The objective of the study was to test whether increased CBFV during the acute phase of purulent meningitis reflects hyperemia, and to evaluate focal perfusion abnormalities and their correlation to CBFV changes.In eight patients with marked side‐differences in CBFVs during the acute phase of the disease SPECT scans were normal in five. In three patients unilateral perfusion defects correlated with the side of higher CBFV. In seven patients presenting with symmetrically elevated CBFV, SPECT scans were normal in four and revealed focal abnormalities in the remaining three. Follow up SPECT scans were normal in 14/15 patients.The results of our study suggest that elevated CBFV in acute bacterial meningitis does not reflect cerebral hyperemia. Focal cerebral perfusion defects occur independently from functional alterations in the cerebral macrovasculature. A causative pathophysiologic relationship of high CBFV and focal perfusion defects cannot be drawn from these data.
Researching a differential impairment of frontal functions and explicit memory in early Parkinson’s disease
Authors: Farina E. , Gattellaro G. , Pomati S. , Magni E. , Perretti A. , Cannatà A. P. , Nichelli P. , Mariani C. 
Published: March 2003

An impairment at tasks sensitive to frontal lobe damage has been repeatedly reported in Parkinson’s disease, but the exact nature of these deficits has not yet been clarified. Similarly, deficits of visuo‐spatial functions have been frequently observed, but it is still debated whether verbal and visuo‐spatial memory can be differentially affected. In this study we have compared the performance of 20 mild Parkinson’s disease patients (I–II Hoehn and Yahr stage) and 18 matched normal controls, at tasks assessing frontal functions and explicit memory.We detected a selective deficit in set shifting and maintaining, without impairment in categorization and set formation. The lack of a selective increase in perseverative errors might indicate that perseverations either measure something different from set shifting or that they do not represent an index sensitive enough to set shifting impairment.Parkinson’s disease patients were also significantly impaired at Raven’s Progressive Matrices, a task assessing both frontal and visuo‐spatial aspects. However, they did not show any differential impairment of visuo‐spatial memory. Indeed, despite a trend of lower performance in visuo‐spatial learning, memory performance of Parkinson’s disease patients was significantly different from that of controls only at a free recall test which involved both verbal and visuo‐spatial memory.We suggest the exploration of set shifting and maintaining to detect ‘frontal’ deficits in mild Parkinson’s disease. We argue that Raven’s Progressive Matrices is a valuable task for detecting subclinical cognitive deficits in Parkinson’s disease, even if it does not show a specific profile of impairment in these patients. According to our results, a differential evaluation of verbal vs. visuo‐spatial memory is not necessary in clinical practice, whilst free recall confirms its usefulness to detect subclinical impairments of memory functions.
Acute neurological stroke care in Europe: results of the European Stroke Care Inventory
Authors: Brainin M. , Bornstein N. , Boysen G. , Demarin V. 
Published: March 2003

Following the 1997 Recommendations of the EFNS Task Force on Acute Neurological Stroke Care (European Journal of Neurology, 1997: 4:435–441) a European Inventory was undertaken to assess the development of acute stroke care in the EFNS member countries and to give an estimate of the needs based on 1997 data.All 30 members of the EFNS Stroke Scientist Panel were asked to complete a questionnaire on acute stroke epidemiology as well as acute stroke care in their country. Data were based either on national surveys, hospital statistics, or estimates given on the basis of extrapolation of regional studies, or other defined sources. Specialist estimates were also taken into account where no other data source was available.Data from 22 countries were received and referred to almost one million strokes occurring per year in a population of over 500 million. Most epidemiological data confirmed an east–west gap known from previous studies. These included rates that, in eastern countries, were higher for incidence, stroke as a leading cause of death, and 30‐day case‐fatality, and rates that were lower for overall hospitalization or availability of CT scanning. East–west differences were not seen for the total number of acute stroke units or the number of acute stroke units set up within neurological hospital departments, nor for most other quality indicators of acute stroke care with the exception of technological standards in some countries.The higher rates for 30‐day case‐fatality in eastern Europe (mostly above 20%) compared with western Europe (mostly below 20%) are probably caused by a case mix with more severe ischemic strokes and a higher percentage of cerebral haemorrhages admitted for acute care in eastern Europe. This is probably due to the higher prevalence of the most common risk factors for stroke in these countries which tend to result in more severe strokes. This, therefore, underlines the need for stroke prevention programmes especially in eastern Europe. This epidemiological east–west gap is not reflected by most quality indicators for acute stroke care, e.g. total number of acute stroke units available within each country. Most eastern European countries have a well‐developed neurological care system for acute stroke but still have urgent technological and socioeconomical needs. The leading role of clinical neurology in acute stroke care is visible in most but not all European countries.
T1 lesion load and cerebral atrophy as a marker for clinical progression in patients with multiple sclerosis. A prospective 18 months follow‐up study
Authors: Sailer M. , Losseff N. A. , Wang L. , Gawne‐Cain M. L. , Thompson A. J. , Miller D. H. 
Published: March 2003

We investigated the relationship between local tissue destruction, diffuse cerebral atrophy and clinical progression in patients with established multiple sclerosis (MS). Twenty‐nine patients with MS (13 patients with relapsing–remitting and 16 with secondary progressive disease) were included in a prospective serial study. Cerebral volumes, T1 hypointense lesion volumes, T2 hyperintense lesion volumes at baseline and at 18 months follow‐up, and the volume of monthly enhancing lesions from month 0 to month 9 were assessed on magnetic resonance imaging (MRI) brain scans using highly reproducible semi‐automated quantitative techniques. The main outcome measures were the MRI parameters and disability on Kurtzkes’ Expanded Disability Status Scale.There was a significant correlation between the change (increase) in T1 lesion volume and progressive cerebral atrophy, whereas no correlation between the T2 lesion volume and atrophy was seen over the same follow‐up period. The change in T1 lesion volume correlated more strongly than did T2 lesion volume change with the change in disability. We conclude that hypointense abnormalities detected in T1‐weighted brain scans and cerebral atrophy may be directly linked. Although one should bear in mind some potential for reversibility due to inflammatory, oedematous lesions, these MR measures are a useful marker of progressive tissue damage and clinical progression in established MS.
The perception of memory failures in patients with epilepsy
Authors: Piazzini A. , Canevini M. P. , Maggiori G. , Canger R. 
Published: March 2003

The aim of the study is to evaluate the correlation between subjective memory complaints and neuropsychological tests in the epilepsy population.We administered a Self Report Memory Questionnaire, based on possible everyday memory failures, two questionnaires on anxiety and depression and a battery of cognitive tests to 150 patients with epilepsy (n=100 with partial epilepsy, n=50 with idiopathic generalized epilepsy) and a control group (n=50).A discrepancy between the results of the memory questionnaire and the cognitive tests was found in the epilepsy patients: the Self Report Memory Questionnaire did not show any correlation with the psychological tests. The same discrepancy was not seen in the controls, where the memory questionnaire was related to two verbal memory tests.Furthermore, patients with epilepsy reported greater difficulties on the Self Report Memory Questionnaire than the controls (P < 0.05).It appeared that the tendency to overstate memory problems was mainly related to anxiety and depression, but was not connected with the type of epilepsy, nor with its duration (in years). Seizure frequency, on the other hand, seemed to greatly influence mood, which in turn is probably affect subjective memory perception.
A case with cerebral thrombosis receiving tamoxifen treatment
Authors: Akdal G. , Dönmez B. , Çakmakçı H. , Yener G. Gülmen 
Published: March 2003

Cerebral sinus thrombosis (CST) is known to be related to a number of underlying aetiologies including otitis media, trauma, pregnancy, birth control pills, tumours, malnutrition, dehydration, haematologic disorders and malignancy (Fishman, 2000; Raizer and Abbott, 2000). We present the case of a patient with breast cancer receiving the antioestrogen drug tamoxifen who developed CST.A 40‐year‐old female presented as an emergency with a 10‐day history of headache and left sided weakness. On questioning her past medical history included a diagnosis of breast cancer 3 years ago treated by radical mastectomy and tamoxifen 20 mg daily. At the time of admission, neurologic examination revealed a mild left sided hemiparesis and a present Babinksi sign. Non‐contrast enhanced tomography was normal. Magnetic resonance imaging (MRI) showed thrombosis in the superior sagittal sinus, right lateral sinus and jugular vein in addition venous infarction in the right temporal lobe was present (Figs 1a and b). Routine haematology and biochemistry was normal. Anticoagulation tests, antithrombin III, protein S and C levels were also found to be normal. She was treated with anticoagulation therapy and her hemiparesis improved within 3 days. Control MRI showed the resorption of the venous infarction and resolution of the thrombosis (Fig. 1c). T1 weighted contrast enhanced axial (a) and coronal (b) images show unenhancing thrombus in superior sagittal sinus and venous heamorrhagic infarction in the right temporal lobe. Control T1 weighted contrast enhanced MRI image (c) reveals resolution of the thrombus in superior sagittal sinus.image
Interpreting the communication of people with profound and multiple learning difficulties
Authors: Porter Jill , Ouvry Carol , Morgan Maggie , Downs Caroline 
Published: March 2003

SummaryThe present paper highlights some of the issues involved in interpreting the communication behaviours of people with profound and multiple learning difficulties (PMLDs). Both inference and intention can play an important role in the communication process, and this raises a number of difficulties and dangers where one of the communication partners is not in a position to correct misunderstandings. The present authors discuss the importance of validating communication and pose a number of key questions to ask those who are most significant in the life of a person with PMLDs. A case study is provided that illustrates a number of these issues.
Diagnosis and drugs: help or hindrance when people with learning disabilities have psychological problems?
Authors: Stenfert Kroese Biza , Dewhurst Damian , Holmes Guy 
Published: March 2003

SummaryA wide range of prevalence rates of psychiatric disorders in people with learning disabilities has been reported, and as yet, there appears to be no general consensus on how to improve the process of diagnosis in order to achieve better agreement. Distinguishing behavioural disturbance from psychiatric disorders is clearly problematic, and empirical and conceptual issues concerning the nature of these disorders brings into question the validity and reliability of psychiatric diagnosis in people with learning disabilities. Concern has been widely expressed about the high frequency with which psychotropic medication is prescribed to this client group. The present paper reviews some of the recent literature, and questions whether psychiatric diagnosis and the use of psychotropic medication are sufficiently evidence‐based to be justified practice.