bluuebunny/crossref_metadata_2025_split huggingface dataset:
Restaurants and venison marketing: a South African experience
Authors: Radder Laetitia 
Published: March 2003

AbstractWild deer, antelope and other exotic animals have been hunted and their meat consumed for centuries. Although the game industry is the fastest growing agricultural industry in South Africa, the sale of venison constitutes a mere 2% of the estimated annual gross income of the wildlife industry. This is surprising, since, apart from its nutritional value, South African venison is free of diseases and originates from animals in their natural habitat, without human intervention in genetic selection, the use of growth hormones, insecticides, or pesticides. The perceived prejudice of South African consumers against venison could stem from bad taste experiences as a result of ignorance concerning the meat's preparation. The question arises whether away‐from‐home consumption in restaurants, hotels and coffee shops could play a role in introducing consumers to the taste of well‐prepared venison. This exploratory study investigates the supply of and demand for venison at restaurants in the metropolitan areas of the Eastern Cape, the top hunting region of South Africa. It also deals with the management of menus and restaurant owners’ perceptions about consumers’ interest in venison, since it is argued that away‐from‐home consumption can only play a role if restaurant owners or chefs include venison on their menus.
Naturalization and invasion of alien plants: concepts and definitions
Authors: Richardson David M. , Pyšek Petr , Rejmánek Marcel , Barbour Michael G. , Panetta F. Dane , West Carol J. 
Published: March 2003

Abstract.  Much confusion exists in the English‐language literature on plant invasions concerning the terms ‘naturalized’ and ‘invasive’ and their associated concepts. Several authors have used these terms in proposing schemes for conceptualizing the sequence of events from introduction to invasion, but often imprecisely, erroneously or in contradictory ways. This greatly complicates the formulation of robust generalizations in invasion ecology.Based on an extensive and critical survey of the literature we defined a minimum set of key terms related to a graphic scheme which conceptualizes the naturalization/invasion process. Introduction means that the plant (or its propagule) has been transported by humans across a major geographical barrier. Naturalization starts when abiotic and biotic barriers to survival are surmounted and when various barriers to regular reproduction are overcome. Invasion further requires that introduced plants produce reproductive offspring in areas distant from sites of introduction (approximate scales: > 100 m over < 50 years for taxa spreading by seeds and other propagules; > 6 m/3 years for taxa spreading by roots, rhizomes, stolons or creeping stems). Taxa that can cope with the abiotic environment and biota in the general area may invade disturbed, seminatural communities. Invasion of successionally mature, undisturbed communities usually requires that the alien taxon overcomes a different category of barriers.We propose that the term ‘invasive’ should be used without any inference to environmental or economic impact. Terms like ‘pests’ and ‘weeds’ are suitable labels for the 50–80% of invaders that have harmful effects. About 10% of invasive plants that change the character, condition, form, or nature of ecosystems over substantial areas may be termed ‘transformers’.
A PCA‐based modelling technique for predicting environmental suitability for organisms from presence records
Authors: Robertson M. P. , Caithness N. , Villet M. H. 
Published: March 2003

Abstract.We present a correlative modelling technique that uses locality records (associated with species presence) and a set of predictor variables to produce a statistically justifiable probability response surface for a target species. The probability response surface indicates the suitability of each grid cell in a map for the target species in terms of the suite of predictor variables. The technique constructs a hyperspace for the target species using principal component axes derived from a principal components analysis performed on a training dataset. The training dataset comprises the values of the predictor variables associated with the localities where the species has been recorded as present. The origin of this hyperspace is taken to characterize the centre of the niche of the organism. All the localities (grid‐cells) in the map region are then fitted into this hyperspace using the values of the predictor variables at these localities (the prediction dataset). The Euclidean distance from any locality to the origin of the hyperspace gives a measure of the ‘centrality’ of that locality in the hyperspace. These distances are used to derive probability values for each grid cell in the map region. The modelling technique was applied to bioclimatic data to predict bioclimatic suitability for three alien invasive plant species (Lantana camara L., Ricinus communis L. and Solanum mauritianum Scop.) in South Africa, Lesotho and Swaziland. The models were tested against independent test records by calculating area under the curve (AUC) values of receiver operator characteristic (ROC) curves and kappa statistics. There was good agreement between the models and the independent test records. The pre‐processing of climatic variable data to reduce the deleterious effects of multicollinearity, and the use of stopping rules to prevent overfitting of the models are important aspects of the modelling process.
Diversity of zonal páramo plant communities in Ecuador
Authors: Sklenár Petr , Ramsay Paul M. 
Published: March 2003

Abstract.Patterns of vascular plant species diversity in high‐altitude Ecuadorian ecosystems (‘páramos’) are examined. Data from two independent surveys were used: the first from 12 different locations and 192 samples, the other from 18 locations and 243 samples. These surveys included 348 and 284 species, respectively. The data confirmed the occurrence of two main zones in terms of vascular plant species diversity. The grass páramo and superpáramo were distinguished by differences in plant cover, species richness, α‐diversity and β‐diversity. The transition between these two zones begins at around 4000 m. Grass páramo samples comprised more species but the strong dominance of tussock grasses resulted in low equitability compared with the superpáramo, where safe sites for plant survival are limited and the environment does not permit continuous grass cover. Turnover of species across the altitudinal gradient is higher in the grass páramo than in the superpáramo. This is due largely to agricultural fires at lower altitudes, which create a fine‐scale mosaic of burned patches that enhances variability at this scale. Despite the loss of equitability, intermediate levels of fire disturbance appear to promote species richness within the samples. It is suggested that the complex patterns of páramo diversity in the Ecuadorian Andes are largely the outcome of three interrelated factors: altitude, disturbance and the availability of safe sites at the highest altitudes.
A model for range expansion of an introduced species: the common waxbillEstrilda astrildin Portugal
Authors: Silva Tiago , Reino Luís M. , Borralho Rui 
Published: March 2003

Abstract.The common waxbillEstrilda astrildwas first introduced to Portugal from Africa in 1964, and has spread across much of the country and into Spain. We modelled the expansion of the common waxbill on a 20 × 20 km UTM grid in 4‐year periods from 1964 to 1999. The time variation of the square root of the occupied area shows that this expansion process is stabilizing in Portugal, and reasons for this are discussed. Several methods used to model biological expansions are not appropriate for the present case, because little quantitative data are available on the species ecology and because this expansion has been spatially heterogeneous. Instead, colonization on a grid was modelled as a function of several biophysical and spatio‐temporal variables through the fitting of a multivariate autologistic equation. This approach allows examination of the underlying factors affecting the colonization process. In the case of the common waxbill it was associated positively with its occurrence in adjacent cells, and affected negatively by altitude and higher levels of solar radiation.
Complement and its implications in cardiac ischemia/reperfusion: strategies to inhibit complement
Authors: Monsinjon Tiphaine , Richard Vincent , Fontaine Marc 
Published: March 2003

Although reperfusion of the ischemic myocardium is an absolute necessity to salvage tissue from eventual death, it is also associated with pathologic changes that represent either an acceleration of processes initiated during ischemia or new pathophysiological changes that were initiated after reperfusion. This so‐called ‘reperfusion injury’ is accompanied by a marked inflammatory reaction, which contributes to tissue injury. In addition to the well known role of oxygen free radicals and white blood cells, activation of the complement system probably represents one of the major contributors of the inflammatory reaction upon reperfusion. The complement may be activated through three different pathways: the classical, the alternative, and the lectin pathway. During reperfusion, complement may be activated by exposure to intracellular components such as mitochondrial membranes or intermediate filaments. Two elements of the activated complement contribute directly or indirectly to damages: anaphylatoxins (C3a and C5a) and the membrane attack complex (MAC). C5a, the most potent chemotactic anaphylatoxin, may attract neutrophils to the site of inflammation, leading to superoxide production, while MAC is deposited over endothelial cells and smooth vessel cells, leading to cell injury.Experimental evidence suggests that tissue salvage may be achieved by inhibition of the complement pathway. As the complement is composed of a cascade of proteins, it provides numerous sites for pharmacological interventions during acute myocardial infarction. Although various strategies aimed at modulating the complement system have been tested, the ideal approach probably consists of maintaining the activity of C3 (a central protein of the complement cascade) and inhibiting the later events implicated in ischemia/reperfusion and also in targeting inhibition in a tissue‐specific manner.
In vitro function of porcine carotid arteries preserved in UW, HTK and Celsior solutions
Authors: Abrahamse S.T.L. , Dinant S. , Pfaffendorf M. , Van Gulik T.M. 
Published: March 2003

AbstractWe compared the efficacy of histidine‐tryptophan‐ketoglutarate (HTK) and University of Wisconsin (UW) solution with Celsior solution using hypothermically‐preserved porcine carotid arteries and studied the importance of different components of these solutions by preserving carotid arteries in modified HTK solutions.Excised carotid arteries were stored at 4 °C in 0.9% (w/v) NaCl, UW, HTK, Celsior, or a modified HTK solution for up to 14 days. Preservation‐induced changes in smooth muscle cell and endothelial cell function were determined using an organ bath for isometric tension recording.Short‐term preservation (1–3 days) in UW, HTK and Celsior did not significantly alter contractile and relaxation responses of arterial segments when compared to freshly‐excised segments, but significantly impaired these responses in arterial segments stored in 0.9% (w/v) NaCl solution. Long‐term hypothermic preservation of arterial segments (7 and 14 days) in 0.9% (w/v) NaCl and HTK solution almost completely abolished all responses, but only slightly reduced the responses of arterial segments stored in UW solution. Intermediate results were obtained for Celsior. Modifying HTK by replacement of chloride for sulfate and phosphate resulted in improved contractile and relaxation responses after long‐term preservation.With respect to smooth muscle and endothelial function, UW is superior to HTK and Celsior and the absence of chloride or presence of sulfate and phosphate plays a relevant role in this in vitro model of hypothermic preservation of porcine carotid arteries.
Unlicensed and off‐label uses of drugs in paediatrics: a review of the literature
Authors: Cuzzolin Laura , Zaccaron Ada , Fanos Vassilios 
Published: March 2003

AbstractThe off‐label and unlicensed use of drugs to treat children is a common practice that occurs either in hospital or in the community. This derives from the fact that research for establishing drug efficacy and safety in children has not been carried out due to ethical problems, logistical difficulties, financial and legal concerns. In this work we report the studies available in literature documenting the extent of drug use in the paediatric field outside the recommendations of the license. From our analysis, a widespread attitude to prescribe medicines to children outside their product license either in the hospitals or in the community is confirmed. This suggests an immediate action for a more rationale use of drugs in paediatrics, to avoid exposing children and infants to unnecessary risks, but also to avoid depriving them of potentially effective and sometimes life‐saving therapies.
Trimetazidine effect on phospholipid synthesis in ventricular myocytes: consequences in α‐adrenergic signaling
Authors: Tabbi‐Anneni Iméne , Lucien Arnaud , Grynberg Alain 
Published: March 2003

AbstractThe anti‐anginal drug trimetazidine (TMZ) has been shown to increase the synthesis of phospholipids in ventricular myocytes, including phosphatidyl‐inositol (PI). This study focused on the consequences of increasing PI metabolism on α‐adrenergic signaling pathway in cultured rat cardiomyocytes. In the cells treated with TMZ, the synthesis of PI from inositol was largely increased as compared with the control (+55% in 60 min). The stimulation of α‐adrenergic receptors by phenylephrine (PE) induced a dose‐dependent production of inositide phosphates (IPs) by phospholipase C (PLC) activation. However, the amount of available IPs was significantly lower in TMZ‐treated cells, in a dose‐dependant manner. This effect was observed in the presence and absence of the IP1‐phosphatase inhibitor LiCl. The in vitro determination of PLC activity revealed that this effect could not be attributed to the direct inhibition of the enzyme by TMZ. The TMZ‐induced reduction of IPs in the PE‐stimulated cardiomyocytes should be attributed to the increase of inositol recycling and incorporation in membrane structures, elicited by increased phospholipid synthesis. The consequences of this reduction in IPs availability were investigated on the cardiomyocyte hypertrophy induced by α‐adrenergic chronic stimulation. Acute stimulation with PE increased protein synthesis (+50%), but this increase was largely prevented by TMZ. In conclusion, TMZ reduces cell available IPs, by accelerating their recycling in membranes as PI. This effect results in a cytoprotection in the pathological process of hypertrophy elicited by chronic α‐adrenergic stimulation.
Elucidation of structure–function relationships in the lung: contributions from hyperpolarized 3helium MRI
Authors: Kauczor Hans‐Ulrich , Eberle Balthasar 
Published: March 2003

SummaryMagnetic resonance imaging (MRI) using hyperpolarized 3helium (He) gas as the source of signal provides new physiological insights into the structure–function relationships of the lung. Traditionally, lung morphology has been visualized by chest radiography and computed tomography, whereas lung function was assessed by using nuclear medicine. As all these techniques rely on ionizing radiation, MRI has some inherent advantages. 3He MRI is based on ‘optical pumping’ of the 3He gas which increases the nuclear spin polarization by four to five orders of magnitude translating into a massive gain in signal. Hyperpolarized 3He gas is administered as an inhaled ‘contrast agent’ and allows for selective visualization of airways and airspaces. Straightforward gas density images demonstrate the homogeneity of ventilation with high spatial resolution. In patients with lung diseases 3He MRI has shown a high sensitivity to depict ventilation defects. As 3He has some more exciting properties, a comprehensive four‐step functional imaging protocol has been established. The dynamic distribution of ventilation during continuous breathing can be visualized after inhalation of a single breath of 3He gas using magnetic resonance (MR) sequences with high temporal resolution. Diffusion weighted 3He MRI provides a new measure for pulmonary microstructure because the degree of restriction of the Brownian motion of the 3He atoms reflects lung structure. Since the decay of 3He hyperpolarization is dependent on the ambient oxygen concentration, regional and temporal analysis of intrapulmonary pO2 becomes feasible. Thus, pulmonary perfusion, ventilation /perfusion ratio and oxygen uptake can be indirectly assessed. Further research will determine the significance of the functional information with regard to physiology and patient management.
Effects of a Ginkgo biloba extract on forearm haemodynamics in healthy volunteers
Authors: Mehlsen J. , Drabæk H. , Wiinberg N. , Winther K. 
Published: March 2003

SummaryThe aim was to validate possible vasodilating effects of a Ginkgo biloba extract with a secondary aim of finding a pharmacodynamic signal relating to the active component of these extracts. We studied the effect of G. biloba extract on forearm haemodynamics in 16 healthy subjects (nine females, seven males) with a median age of 32 years (range: 21–47). The study was conducted as a randomized, double‐blinded cross‐over design using oral treatment with G. biloba extract (Gibidyl Forte® t.i.d. or placebo for 6 weeks. Forearm blood flow and venous capacity were measured by strain‐gauge plethysmography. Blood pressure was measured by standard sphygmomanometry, and forearm vascular resistance (FVR) was derived. Measurements were made at baseline and after 3, 6, 9 and 12 weeks of treatment. Forearm blood flow was significantly higher during active treatment after 3 and 6 weeks as compared with placebo treatment for 3 and 6 weeks (P<0·05). Mean arterial blood pressure was unchanged, making the calculated FVR significantly lower during active treatment (P<0·02). It is concluded that oral treatment with a G. biloba extract (Gibidyl Forte®) is able to dilate forearm blood vessels causing increments in regional blood flow without changing blood pressure levels in healthy subjects. The increments in blood flow may be used as a biological signal for pharmacokinetic studies.
Ecological Impacts of Introduced Animals in Nahuel Huapi National Park, Argentina
Authors: VEBLEN THOMAS T. , MERMOZ MONICA , MARTIN CARLOS , KITZBERGER THOMAS 
Published: March 2003

Abstract: In Nahuel Huapi National Park in southwestern Argentina, livestock and exotic deer pose important management problems. Due to the economic and social benefits of sport hunting and production of livestock, it is politically impractical to completely eradicate these animals from the park. Instead, park managers attempt to minimize the effects of these introduced animals by preventing their spread into more pristine parts of the park and by trying to diminish their population densities. Managers are also promoting the relocation of livestock production to appropriate sites in the National Reserve part of the park where livestock raising is permitted. Detailed information on the ecological impacts of introduced herbivores is needed both to guide management of the different vegetation types of the park and to support the park managers' public relations campaign justifying exotic animal control.We examined the ecological effects of introduced animals along the vegetation gradient from Andean rain forests through xeric woodlands to the Patagonian steppe. We sampled 30 stands for floristic composition and structure, assessed browse intensity, and compared stands of similar abiotic habitat but of different browsing regimes. Deer and livestock have significantly altered floristic composition and stand structure along this gradient. They impair tree regeneration and pose a long‐term threat to the continued existence of a forest cover.
Rates of Deforestation in Los Tuxtlas, a Neotropical Area in Southeast Mexico
Authors: DIRZO RODOLFO , GARCIA MARIA C. 
Published: March 2003

Abstract: On the basis of ground surveys, aerial photographs (for 1967 and 1976), and satellite imagery (for 1986), maps of rain forest distribution were developed for the northern part of the Sierra de Los Tuxtlas (Veracruz, southeast Mexico).Forest coverage maps for 1967, 1976, and 1986 show dramatic deforestation proceeding up from the lowlands, with the remaining natural vegetation now increasingly restricted to the high, steep, and less accessible parts of the Sierra. From the digitizing of the maps it was estimated that (1) during the nearly 20 years of this analysis the vegetation was reduced by 56%, and (2) by early 1986, approximately 84% of the original forest area had been lost.The derived annual deforestation rates (expressed as the percentage of remaining forest that is cleared per year) were 4.2% for the interval 1967–1976 and 4.3% for 1976–1986. Were these trends and rates to continue, only 8.7% of the original vegetation would persist by the year 2000, and then only in the form of an archipelago of very small forest fragments of which the largest would be the now‐protected areas (e.g, the Los Tuxtlas Biological Station with only 640 ha), and the most inaccessible tracts.Immediate action is urgently needed to protect these small but rich remnants and preserve them as foci of potential biological inocula for future ecorestoration of these, the northernmost tropical forests on the continent.
Smoking and Smoking Relapse During Pregnancy and Postpartum: Results of a Qualitative Study
Authors: Edwards Nancy , Sims‐Jones Nicki 
Published: March 2003

Background:The purpose of this study was to describe women's smoking experience during pregnancy and postpartum. Primiparous women recruited during a randomized controlled trial to assess the effectiveness of postpartum visiting were invited to participate in a qualitative study.Methods:A semistructured protocol guided the face‐to‐face interview. Interviews were audiotaped and transcribed. Data were coded independently by the authors, and the final coding system for emergent themes was developed through a consensus process.Results:Of the 47 women invited to participate, 22 agreed to be interviewed. Three major themes emerged from the analysis: pregnancy as a context for stopping smoking, returning to smoking, and social pressures on smoking behavior. Concerns about the baby's health were cited as central reasons for stopping. Breastfeeding provided a reason for continued smoking cessation, whereas social events often demarcated a resumption of women's smoking choices.Conclusions:Results provide guidance for the timing and content of interventions to prevent smoking relapse. (BIRTH 25:2 June 1998)