Does Perceived Nuisance Abundance of Water Plants Match with Willingness-to-Pay for Removal? Contrasts Among Different User Categories.

Dense beds of water plants can be perceived as nuisance, but this perception, however, may not be similar for different user categories, and this may affect their willingness-to-pay (WTP) for plant removal. A questionnaire survey was used to test this for residents and visitors and find underlying socio-cultural or economic drivers. We studied five cases where nuisance water plant growth is managed: the rivers Otra (Norway) and Spree (Germany), and the lakes Kemnade (Germany), Grand-Lieu (France), and Hartbeespoort Dam (South Africa).

Causes of macrophyte mass development and management recommendations.

Aquatic plants (macrophytes) are important for ecosystem structure and function. Macrophyte mass developments are, however, often perceived as a nuisance and are commonly managed by mechanical removal. This is costly and often ineffective due to macrophyte regrowth.

A shift in habitat use patterns of brown trout (Salmo trutta): A behavioural response to macrophyte removal.

Mass development of macrophytes is an increasing problem worldwide and they are frequently removed where they are in conflict with local waterway users. Yet, macrophytes can provide important refuge and nursery habitats for fish. Little is known about the consequences of macrophyte removal for fish behavioural space use and habitat selection.

Drivers of Perceived Nuisance Growth by Aquatic Plants.

Mass developments of macrophytes occur frequently worldwide and are often considered a nuisance when interfering with human activities. It is crucial to understand the drivers of this perception if we are to develop effective management strategies for ecosystems with macrophyte mass developments. Using a comprehensive survey spanning five sites with different macrophyte species in four countries (Norway, France, Germany and South Africa), we quantified the perception of macrophyte growth as a nuisance among residents and visitors, and for different recreational activities (swimming, boating, angling, appreciation of biodiversity, appreciation of landscape and birdwatching).

Short-term effects of macrophyte removal on aquatic biodiversity in rivers and lakes.

Mass development of macrophytes is an increasing problem in many aquatic systems worldwide. Dense mats of macrophytes can negatively affect activities like boating, fishing or hydropower production and one of the management measures often applied is mechanical removal. In this study, we analyzed the effect of mechanical macrophyte removal on phytoplankton, zooplankton, and macroinvertebrate (pelagic and benthic samples) assemblages.

Mechanical removal of macrophytes in freshwater ecosystems: Implications for ecosystem structure and function.

Macrophytes are generally considered a nuisance when they interfere with human activities. To combat perceived nuisance, macrophytes are removed, and considerable resources are spent every year worldwide on this practice. Macrophyte removal can, however, have severe negative impacts on ecosystem structure and functioning and interfere with management goals of healthy freshwater ecosystems.

[New analgesically-active N'-acylated phenylpiperazines].

Synthesis and pharmacodynamic properties of new analgesic active N'-acylated phenylpiperazines are described. 1-(3-Cyclohexyl-1-oxo-propyl)-4-(2-ethoxyphenyl)-piperazine (D 16 120) possesses strong non-opiate antinociceptive activity showing high therapeutic margin with respect to undesired side effects and toxicity.

[Pharmacokinetics and biotransformation of the analgesic flupirtine in the rat and dog].

Pharmacokinetics and biotransformation of 14C-labelled ethyl-N-[2-amino-6-(4-fluorophenylmethylamino)pyridin-3-yl]carbama te maleate (flupirtine maleate, D 9998 maleate) was studied in rats and dogs. The drug was rapidly and completely absorbed after peroral administration in both species. The kinetics of the plasma levels after intravenous administration show a short distribution phase followed by an elimination phase with half-lives between 2 and 3 h.

[General pharmacologic studies on the analgesic flupirtine].

In the present study the general pharmacological properties of ethyl-N-[2-amino-6-(4-fluor-phenylmethylamino)pyridin-3-yl]carbama te (flupirtine, D 9998), a structural new analgesic, are described. In several tests with mice flupirtine shows a centrally depressant component of action. However, regarding undesirable side effects as ataxia, inhibition of motor activity etc.

[The pharmacologic effect of flupirtine, a structurally new analgesic].

The analgesic potency of ethyl-N-[2-amino-6-(4-fluorophenylmethylamino)pyridin-3-yl]carb ama te (flupirtine, D 9998) in mice and rats in Haffner's test, electro-pain test and Randall-Selitto test (inflammation induced pain) lies between the more potent dextromoramide and methadone and the more weakly active pethidine, dextropropoxyphene, codeine, phenacetin and paracetamol. In comparison to codeine flupirtine is up to 4 times more potent, up to 2 times more active than pethidine and 4 times more potent than dextropropoxyphene in the above-mentioned methods. With one exception of inflammation induced pain, where flupirtine shows an activity of about 1 1/2 times that of phenacetin and paracetamol, both analgesics are about 10 to nearly 30 times less active than flupirtine in other above-mentioned tests.

[The pharmacology of a new cardiosteroid, a partially synthetic derivative of the aglycone hellebrigenin (acrihellin)].

3 beta,5,14-Trihydroxy-19-oxo-5 beta-bufa-20,22-dienolide 3-(3-methylcrotonate) (acrihellin, D 12 316) is according to chemical structure and pharmacological effects a semisynthetic compound of the aglycon hellebrigenin. It is characterized as a cardiosteroid. In isolated organ (Langendorff heart) the positive inotropic effect proved to be stronger in comparison to digoxin.

A method for induction of cold, indomethacin and restraint ulcers in rats.

A new method has been developed for producing gastric ulcers in rats. The rapid induction of gastric lesions was achieved by a combination of the administration of indomethacin in addition to cold and restraint stressors. Ulcer indices were easily reproducible and remained constant.

Synthesis of orally active cardiosteroid derivatives.

Starting from hellebrigenin, orally cardiotonic active acylcardiosteroid derivatives have been synthesized. D 12316 (acrihellin), the hellebrigenin-3 beta-dimethylacrylate, has been chosen for clinical evaluation.

[Investigations on the general effects of tinofedrine on heart and blood circulation (author's transl)].

In anesthetized dogs, (+)-(R)-alpha ((S)-1-[(3,3-di-3-thienylallyl)amino]-ethyl)-benzylalcohol hydrochloride (tinofedrine hydrochloride, D 8955) causes a remarkable increase of cardiac output by positive inotropic and chronotropic stimulation of the heart and simultaneous reduction of peripheral vascular resistance. The effect is antagonized by beta-adrenergic blocking drugs. In comparison with typical beta-agonists (e.

[Human pharmacokinetics of theophylline and etofylline from different formulations of a cardiotonic (author's transl)].

Serum concentrations of theophylline and etofylline were analysed by a specific HPLC-method in 6 volunteers after i.v. and p.

[New cerebrally active basic dithienyl compounds (author's tranls)].

A review on new cerebrally active basic dithienyl compounds related to (+)-(R)-alpha-((S)-1-[(3,3-di-3-thienylallyl)amino]-ethyl)-benzylalcohol (tinofedrine) is presented. Tinofedrine was selected out of a large number of related compounds on account of its high increase of cerebral blood flow, its improvement of heart performance, of the metabolism of the brain, and because it is well toleraded. Different routes of synthesis are discussed.

Does gastrin (pentagastrin) act directly on the parietal cell in the isolated whole stomach of the mouse?

Acid secretory effect of pentagastrin and compound 48/80 was studied in the isolated whole stomach of the mouse. Acid secretory response to compound 48/80 was inhibited by cimetidine, indicating histamine involvement in this reaction. Acid secretion stimulated by pentagastrin was not diminished after pre-treatment with compound 48/80 suggesting that gastrin releases non-mast cell histamine.

Distention ulcer as a model for testing of drugs for ulcerogenic side effects.

A modification of the distention ulcer was studied in albino rats and a new possibility of testing ulcerogenic side effects of drugs was described. The distention alone was not sufficient to produce lesions. The severity of ulcer lesions was highly dependent on the volume of the acid solution.

[Treatment of distortions and non-traumatic conditions of pain and swelling. Double-blind trial with an analgetic and detumescent drug combination].

A combination of specifically detumescent and analgesic/antiphlogistic substances (Dolo Mobilat film tablets) was tested in a double-blind study against placebo. The active product brought about very good or good therapeutic results in approximately 78% of 50 patients suffering from distortions of joints and from painful inflammation and swelling of non-traumatic origin; the corresponding percentage obtained with the placebo was 34%. Separate evaluations of pain and swellings most relevant for their homogeneity in distortions of joints showed rates of 80% and 31%, respectively.

[Studies on the pharmacokinetics and metabolism of tinofedrine].

Pharmacokinetics and biotransformation of l-(+)-alpha-(1-[(3,3-di-3-thienylallyl)-amino]-ethyl)-3-benzyl alcohol hydrochloride (tinofedrine hydrochloride, D 8955, Novocebrin) were investigated in rat and dog by means of the 3H-labelled drug. After i.v.