48 research outputs found
Termoreverzibilni mukoadhezivni in situ hidrogel za oftalmiÄku primjenu: dizajniranje i optimizacija koristeÄi kombinaciju polimera
The purpose of the study was to develop an optimized thermoreversible in situ gelling ophthalmic drug delivery system based on Pluronic F 127, containing moxifloxacin hydrochloride as a model drug. A 32 full factorial design was employed with two polymers Pluronic F 68 and Gelrite as independent variables used in combination with Pluronic F 127. Gelation temperature, gel strength, bioadhesion force, viscosity and in vitro drug release after 1 and 10 h were selected as dependent variables. Pluronic F 68 loading with Pluronic F 127 was found to have a significant effect on gelation temperature of the formulation and to be of importance for gel formation at temperatures 3336 ÂșC. Gelrite loading showed a positive effect on bioadhesion force and gel strength and was also found helpful in controling the release rate of the drug. The quadratic mathematical model developed is applicable to predicting formulations with desired gelation temperature, gel strength, bioadhesion force and drug release properties.Cilj rada bio je razvoj i optimizacija termoreverzibilnog sustava za isporuku lijekova koji gelira in situ. Sustav je napravljen na bazi Pluronic F 127, a sadrĆŸi moksifloksacin hidroklorid kao modelni lijek. U radu je primjenjeno 32 potpuno faktorijsko dizajniranje s dva polimera, Pluronic F 68 i Gelrite kao nezavisnim varijablama koji su kombinirani s Pluronic F 127. Kao zavisne varijable odabrane su temperatura geliranja, ÄvrstoÄa gela, jaÄina bioadhezije, viskoznost i in vitro oslobaÄanje lijeka nakon 1 i 10 h. PronaÄeno je da Pluronic F 68 u kombinaciji s Pluronic F 127 ima znaÄajan uÄinak na temperaturu geliranja u rasponu od 33 do 36 C. S druge strane, Gelrite ima povoljan uÄinak na jaÄinu bioadhezije, ÄvrstoÄu gela i oslobaÄanje lijeka. Razvijen je kvadratni matematiÄki model pomoÄu kojeg se moĆŸe predvidjeti temperatura geliranja, ÄvrstoÄa gela, jaÄina bioadhezije i oslobaÄanje ljekovite tvari
Tackling invasive alien species in Europe: The top 20 issues
Globally, Invasive Alien Species (IAS) are considered to be one of the major threats to native biodiversity, with the World Conservation Union (IUCN) citing their impacts as âimmense, insidious, and usually irreversibleâ. It is estimated that 11% of the c. 12,000 alien species in Europe are invasive, causing environmental, economic and social damage; and it is reasonable to expect that the rate of biological invasions into Europe will increase in the coming years. In order to assess the current position regarding IAS in Europe and to determine the issues that were deemed to be most important or critical regarding these damaging species, the international Freshwater Invasives - Networking for Strategy (FINS) conference was convened in Ireland in April 2013. Delegates from throughout Europe and invited speakers from around the world were brought together for the conference. These comprised academics, applied scientists, policy makers, politicians, practitioners and representative stakeholder groups. A horizon scanning and issue prioritization approach was used by in excess of 100 expert delegates in a workshop setting to elucidate the Top 20 IAS issues in Europe. These issues do not focus solely on freshwater habitats and taxa but relate also to marine and terrestrial situations. The Top 20 issues that resulted represent a tool for IAS management and should also be used to support policy makers as they prepare European IAS legislation. © 2014 The Author(s)
Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea)
International audienceRates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach
The bear in Eurasian plant names: Motivations and models
Ethnolinguistic studies are important for understanding an ethnic group's ideas on the world, expressed in its language. Comparing corresponding aspects of such knowledge might help clarify problems of origin for certain concepts and words, e.g. whether they form common heritage, have an independent origin, are borrowings, or calques. The current study was conducted on the material in Slavonic, Baltic, Germanic, Romance, Finno-Ugrian, Turkic and Albanian languages. The bear was chosen as being a large, dangerous animal, important in traditional culture, whose name is widely reflected in folk plant names. The phytonyms for comparison were mostly obtained from dictionaries and other publications, and supplemented with data from databases, the co-authors' field data, and archival sources (dialect and folklore materials). More than 1200 phytonym use records (combinations of a local name and a meaning) for 364 plant and fungal taxa were recorded to help find out the reasoning behind bear-nomination in various languages, as well as differences and similarities between the patterns among them. Among the most common taxa with bear-related phytonyms were Arctostaphylos uva-ursi (L.) Spreng., Heracleum sphondylium L., Acanthus mollis L., and Allium ursinum L., with Latin loan translation contributing a high proportion of the phytonyms. Some plants have many and various bear-related phytonyms, while others have only one or two bear names. Features like form and/or surface generated the richest pool of names, while such features as colour seemed to provoke rather few associations with bears. The unevenness of bear phytonyms in the chosen languages was not related to the size of the language nor the present occurence of the Brown Bear in the region. However, this may, at least to certain extent, be related to the amount of the historical ethnolinguistic research done on the selected languages
Editorial: Conservation of European Freshwater Crayfish
Freshwater ecosystem functioning is often thought to be dominated by fish, determining the community structure via top-down control and ecosystem engineering. However, freshwater crayfish can have an even stronger effect on food web and ecosystem functioning, operating as keystone species in a water body (Longshaw and Stebbing, 2016). As environmental engineers, crayfish have a significant impact on the biodiversity within their habitat (Souty-Grosset et al., 2006). Yet over the past 150 years freshwater crayfish in Europe have faced a novel challenge in the form of a lethal disease caused by the oomycete Aphanomyces astaci Schikora 1906, introduced by alien crayfish species of North American origin. Today, the European native crayfish population trends are in decline nearing extinction in several cases (Souty-Grosset et al., 2006; Jussila et al., 2014).
The introduction of different A. astaci strains in Europe and the repeated introductions of their North American host species are a classic example of a man-made ecological disaster (Jussila et al.), stemming from the naive belief that the manipulation of an ecosystem would be straightforward. The alien crayfish species, which were supposed to replace the eradicated native stocks, not only transfer the deadly disease but in many parts of Europe also outcompete their native crayfish counterparts, because they are more aggressive giving them additional advantage regarding habitat competition in addition to higher fecundity (Alonso and MartĂnez, 2006). Introductions of new alien crayfish stocks and thus new A. astaci strains will inevitably lead to the total eradication of the remaining native European crayfish stocks.
In this Research Topic we collected scientific work on crayfish conservation from multiple scales, ranging from molecular to species and ecosystem levels, to address the consequences of invasive crayfish and host-parasite interactions on European freshwater biodiversity and ecosystem functioning, aiding conservation and management of European freshwater crayfish to prevent them from extinction