Taming the terminological tempest in invasion science.

Standardised terminology in science is important for clarity of interpretation and communication. In invasion science - a dynamic and rapidly evolving discipline - the proliferation of technical terminology has lacked a standardised framework for its development. The result is a convoluted and inconsistent usage of terminology, with various discrepancies in descriptions of damage and interventions. A standardised framework is therefore needed for a clear, universally applicable, and consistent terminology to promote more effective communication across researchers, stakeholders, and policymakers. Inconsistencies in terminology stem from the exponential increase in scientific publications on the patterns and processes of biological invasions authored by experts from various disciplines and countries since the 1990s, as well as publications by legislators and policymakers focusing on practical applications, regulations, and management of resources. Aligning and standardising terminology across stakeholders remains a challenge in invasion science. Here, we review and evaluate the multiple terms used in invasion science (e.g. 'non-native', 'alien', 'invasive' or 'invader', 'exotic', 'non-indigenous', 'naturalised', 'pest') to propose a more simplified and standardised terminology. The streamlined framework we propose and translate into 28 other languages is based on the terms (i) 'non-native', denoting species transported beyond their natural biogeographic range, (ii) 'established non-native', i.e. those non-native species that have established self-sustaining populations in their new location(s) in the wild, and (iii) 'invasive non-native' - populations of established non-native species that have recently spread or are spreading rapidly in their invaded range actively or passively with or without human mediation. We also highlight the importance of conceptualising 'spread' for classifying invasiveness and 'impact' for management. Finally, we propose a protocol for classifying populations based on (i) dispersal mechanism, (ii) species origin, (iii) population status, and (iv) impact. Collectively and without introducing new terminology, the framework that we present aims to facilitate effective communication and collaboration in invasion science and management of non-native species.

Survival, Growth, and Reproduction: Comparison of Marbled Crayfish with Four Prominent Crayfish Invaders.

Biological invasions are increasingly recognized ecological and economic threats to biodiversity and are projected to increase in the future. Introduced freshwater crayfish in particular are protruding invaders, exerting tremendous impacts on native biodiversity and ecosystem functioning, as exemplified by the North American spiny-cheek, signal and red swamp crayfish as well as the Australian common yabby. The marbled crayfish is among the most outstanding freshwater crayfish invaders due to its parthenogenetic reproduction combined with early maturation and high fecundity. As their introduced ranges expand, their sympatric populations become more frequent. The question of which species and under what circumstances will dominate in their introduced communities is of great interest to biodiversity conservation as it can offer valuable insights for understanding and prioritization of management efforts. In order to examine which of the aforementioned species may be more successful as an invader, we conducted a set of independent trials evaluating survival, growth, claw injury, and reproduction using single-species stocks (intraspecific interactions) and mixed stocks (interspecific interactions) of marbled crayfish vs. other crayfish invaders since the onset of exogenous feeding. In both single and mixed stocks, red swamp crayfish and yabby grew faster than marbled crayfish, while marbled crayfish were superior to both spiny-cheek and signal crayfish in terms of growth. With the exception of signal crayfish, the faster-growing species consistently reached a higher survival rate. The faster-growing species tended to negatively impair smaller counterparts by greater claw injury, delayed maturation, and reduced fecundity. Only marbled crayfish laid eggs as early as 14 weeks in this study, which is earlier than previously reported in the literature. Thus, the success of marbled crayfish among invasive crayfish is significantly driven by relatively fast growth as well as an early and frequent reproduction. These results shed light on how interactions between invasive populations can unfold when their expansion ranges overlap in the wild, thereby contributing to the knowledge base on the complex population dynamics between existing and emerging invasive species.

Natural substance rutin versus standard drug atorvastatin in a treatment of metabolic syndrome-like condition.

BACKGROUND: Metabolic syndrome is a cluster of metabolic risk factors. The clear causes of its development are not known yet and there is no comprehensive treatment of this disease. There is a trend to use natural substances in the treatment of various diseases, but their effects need to be well explored. We decided to test effect of rutin compared to the effect of the standard drug atorvastatin. METHODS: As a model of metabolic syndrome we used males of hypertriacylglycerolemic rats in combination with high-fat-high-fructose diet. Rutin (100 mg/kg) and atorvastatin (50 mg/kg) were administered orally daily for 5 weeks. RESULTS: We determined biochemical parameters from blood: HDL-cholesterol, LDL-cholesterol, total cholesterol, triacylglycerols. Relaxation and contraction response of aorta was measured to determine vessel dysfunctions and possible predisposition to cardiovascular disease. The negative influence on cognitive functions could be associated with the development of metabolic cognitive syndrome. Therefore we aimed to monitor spatial memory by Morris water maze test. Both rutin and atorvastatin had a tendency to decrease levels of serum triacylglycerols, but only atorvastatin significantly reduced levels od LDL-cholesterol and increased HDL-cholesterol levels. Both compounds significantly reduced the phenylephrine-induced contractile response of the aorta and improved the relaxation response. Further, treated animals learned better compared to untreated rats in the Morris water maze. CONCLUSION: Based on our results we can assume that atorvastatin and rutin had positive effect on spatial memory and vessel reactivity. Atorvastatin optimized lipid profile of blood serum.

Melatonin receptor activation protects against low potassium-induced ventricular fibrillation by preserving action potentials and connexin-43 topology in isolated rat hearts.

Hypokalemia prolongs the QRS and QT intervals, deteriorates intercellular coupling, and increases the risk for arrhythmia. Melatonin preserves gap junctions and shortens action potential as potential antiarrhythmic mechanisms, but its properties under hypokalemia remain unknown. We hypothesized that melatonin protects against low potassium-induced arrhythmias through the activation of its receptors, resulting in action potential shortening and connexin-43 preservation. After stabilization in Krebs-Henseleit solution (4.5 mEq/L K+ ), isolated hearts from Wistar rats underwent perfusion with low-potassium (1 mEq/L) solution and melatonin (100 µmol/L), a melatonin receptor blocker (luzindole, 5 µmol/L), melatonin + luzindole or vehicle. The primary endpoint of the study was the prevention of ventricular fibrillation. Electrocardiography was used, and epicardial action potentials and heart function were measured and analyzed. The ventricular expression, dephosphorylation, and distribution of connexin-43 were examined. Melatonin reduced the incidence of low potassium-induced ventricular fibrillation from 100% to 59%, delayed the occurrence of ventricular fibrillation and induced a faster recovery of sinus rhythm during potassium restitution. Melatonin prevented QRS widening, action potential activation delay, and the prolongation of action potential duration at 50% of repolarization. Other ECG and action potential parameters, the left ventricular developed pressure, and nonsustained ventricular arrhythmias did not differ among groups. Melatonin prevented connexin-43 dephosphorylation and its abnormal topology (lateralization). Luzindole abrogated the protective effects of melatonin on electrophysiological properties and connexin-43 misdistribution. Our results indicate that melatonin receptor activation protects against low potassium-induced ventricular fibrillation, shortens action potential duration, preserves ventricular electrical activation, and prevents acute changes in connexin-43 distribution. All of these properties make melatonin a remarkable antifibrillatory agent.

Effect of metabolic syndrome on neural plasticity and morphology of the hippocampus: correlations of neurological deficits with physiological status of the rat.

Fat-rich diet (FRD) triggers health complications like hypertension, dyslipidemia, hyperglycemia, insulin resistance and non-alcoholic fatty liver disease, known as the risk factors of metabolic syndrome (MetS), which may result in neurological deficits. The impact of MetS on neuronal functions and brain morphology are poorly understood. We induced MetS-like conditions by exposing hypertriacylglycerolemic (HTG) rats to FRD for eight weeks with the aim to study possible neurological dysfunctions. HTG-FRD rats were compared to HTG rats and Wistar rats on standard diet. The physiological status of the animals was monitored by body, liver and kidney weight. Morphology of the liver, vessel wall and hippocampus were investigated. Basal neurotransmission and synaptic plasticity were measured in the hippocampus ex-vivo. A marked increase of liver weight with marks of steatosis was found in the HTG-FRD group. FRD induced an increase of aortic intima-media thickness. Extracellular recording revealed FRD-induced impairment of long-term potentiation (LTP) at Cornu Ammonis (CA)3-CA1 synapse, contrary to increased presynaptic fiber volley (pV). Reduced thickness of pyramidal cell layer at the CA1 area was found morphometrically. LTP was directly associated with kidney weight and inversely associated with liver weight, pV directly correlated with liver weight, liver/body wt ratio and aortic intima-media thickness. Our results suggest correlations between altered physiological status due to MetS-like conditions and neurological deficits, which may be related with consecutive development of so-called metabolic cognitive syndrome.

Beneficial effect of 6 weeks lasting handling of adult rats on spatial memory in experimental model of neurodegeneration.

Handling is a form of experience which can result in physiological changes depending on the period of postnatal age when performed. There is a lot of evidence about the positive effect of neonatal handling, but a lack dealing with handling of adult rats. Behavioral changes and memory deficits are present in dementia-like disorders. In the present work, we tested whether 6 weeks lasting handling of young adult rats could revert memory impairment induced by trimethyltin (TMT) (7.5 mg/kg, intraperitoneally). Testing rats in Morris water maze revealed significant effect of TMT as well significant effect of handling. We observed improvement of spatial memory also between healthy, non-degenerated rats as well as degenerated rats, represented by shorter latency onto the platform. In our paper, we report beneficial effect of handling on spatial memory that is in compliance with published works about beneficial effect of cognitive therapy and training in patients with early stage of Alzheimer΄s disease and dementia.

Neuronal marker recovery after Simvastatin treatment in dementia in the rat brain: in vivo magnetic resonance study.

The aim of study was to search for new biomarkers with a magnetic resonance technique to identify the early stages of dementia, induced by D-galactose, and evaluate Simvastatin therapy. Localized proton magnetic resonance spectroscopy measurements showed a significant decrease in the concentration of N-acetylaspartate+N-acetylaspartylglutamate and myo-inositol in the D-galactose group compared to the control group, and, conversely, an increase of N-acetylaspartate+N-acetylaspartylglutamate in the D-galactose/Simvastatin group. Using a saturation transfer experiment, with phosphorus magnetic resonance spectroscopy, we observed a significant elevation of the forward rate constant of the creatine kinase reaction in the brains of the D-galactose group compared to controls, and subsequently, a significant reduction of this reaction in the D-galactose/Simvastatin group. Spatial learning and memory were evaluated using the modified Morris water maze test. The dynamics of the learning process represented by the learning index revealed a significant reduction in learning in the D-galactose group, but the deficits as a consequence of the D-galactose effects were recovered in the D-galactose/Simvastatin group, in which the learning dynamics resembled those of the control group. By determining the thiobarbituric acid reactive substances and total coenzyme Q9 in plasma, we have shown that long-term administration of D-galactose created conditions for oxidative stress, and that the administration of Simvastatin decreased oxidative stress in plasma. Volumetry analyses from the hippocampal area show a reduction in the segmented area in the D-galactose group, compared with the control group, and an enlarged area in the hippocampus in the d-galactose/Simvastatin group.