44 research outputs found
Recovery of high mountain Alpine lakes after the eradication of introduced brook trout Salvelinus fontinalis using non-chemical methods
The final publication is available at Springer via http://dx.doi.org/10.1007/s10530-018-1867-0Fish stocking is a serious threat to originally fishless mountain lakes. We used non-chemical eradication methods (i.e. gillnetting and electrofishing) in four high mountain lakes in the Gran Paradiso National Park (Western Italian Alps) to eradicate alien brook trout Salvelinus fontinalis. Data of amphibians, macroinvertebrates, zooplankton, chlorophyll-a, nutrient concentrations, and water transparency were used as indicators of the recovery process. All treated lakes were returned to their original fishless condition in spite of their different sizes and habitat complexity, without permanent negative side-effects for native species. Several ecological indicators showed that many impacts of introduced fish can be reversed over a short time period following eradication. The present study adds to a still growing body of specialized literature on the recovery of habitats after the eradication of alien species and provides further evidence that physical eradication methods are effective and can be part of a more general strategy for the conservation of high mountain lake biota
Why Should We Preserve Fishless High Mountain Lakes?
High mountain lakes are originally fishless, although many have had introductions of non-native fish species, predominantly trout, and recently also minnows introduced by fishermen that use them as live bait. The extent of these introductions is general and substantial often involving many lakes over mountain ranges. Predation on native fauna by introduced fish involves profound ecological changes since fish occupy a higher trophic level that was previously inexistent. Fish predation produces a drastic reduction or elimination of autochthonous animal groups, such as amphibians and large macroinvertebrates in the littoral, and crustaceans in the plankton. These strong effects raise concerns for the conservation of high mountain lakes. In terms of individual species, those adapted to live in larger lakes have suffered a higher decrease in the size of their metapopulation. This ecological problem is discussed from a European perspective providing examples from two study areas: the Pyrenees and the Western Italian Alps. Species-specific studies are urgently needed to evaluate the conservation status of the more impacted species, together with conservation measures at continental and regional scales, through regulation, and at local scale, through restoration actions, aimed to stop further invasive species expansions and to restore the present situation. At different high mountain areas of the world, there have been restoration projects aiming to return lakes to their native fish-free status. In these areas autochthonous species that disappeared with the introduction of fish are progressively recovering their initial distribution when nearby fish-free lakes and ponds are available
[Experimental research on the regenerative capacity of fetal tissue of the extremities injured by teratogenic insult to vascular bases]
[Experimental research on the regenerative capacity of fetal tissue of the extremities injured by teratogenic insult to vascular bases
[Experimental acroaplasia: study of its etiopathogenetic mechanism]
[Experimental acroaplasia: study of its etiopathogenetic mechanism
[Increased production of alveolar surfactant in the human fetus after treatment with cytidine diphosphocholine]
[Increased production of alveolar surfactant in the human fetus after treatment with cytidine diphosphocholine
The effect of follicle-stimulating hormone theraphy on sperm quality: an ultrastructural mathematical evaluation.
We investigated the effect of follicle-stimulating hormone (FSH) administration on the ultrastructure of spermatozoa in order to evaluate the potential of FSH therapy for improving sperm quality. Forty-six patients exhibiting idiopathic oligoasthenoterato-zoospermia who attended the intrauterine insemination (IU), in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI) program at our clinic received FSH in daily dosages of 150 IU over a period of 12 weeks. Using transmission electron microscopy, the ultrastructural analysis of spermatozoa was performed prior to the start of FSH therapy, after the treatment had been finished, and 6 weeks posttherapy. Applying a mathematical formula based on submicroscopic characteristics, we calculated the number of morphologically normal spermatozoa. After the FSH treatment, the examined subcellular organelles achieved a higher percentage of integrity. Follicle-stimulating hormone treatment leads to a higher number of morphologically normal spermatozoa. The electron microscopic findings indicate that treatment with pure FSH may be an effective way to improve sperm quality in cases with oligoasthenoterato-zoospermia. Applying the mathematical analysis based on the whole complex of the selected sperm characteristics, we obtained a way to evaluate the success of therapy for the first time
Kinin-kininase system in drug addict woman in pregnancy and puerperium
No abstract availabl
[Effects of maternal methadone addiction on the growth and health of the fetus]
No abstract availabl
Antibody responses to hepatitis C virus hypervariable region 1: Evidence for cross-reactivity and immune-mediated sequence variation
Sequence heterogeneity of hepatitis C virus (HCV) is unevenly distributed along the genome, and maximal variation is confined to a short sequence of the HCV second envelope glycoprotein (E2), designated hypervariable region 1 (HVR1), whose biological function is still undefined. We prospectively studied serological responses to synthetic oligopeptides derived from HVR1 sequences of patients with acute and chronic HCV infection obtained at baseline and after a defined follow-up period. Extensive serological cross-reactivity for unrelated HVR1 peptides was observed in the majority of the patients. Antibody response was restricted to the IgG1 isotype and was focused on the carboxyterminal end of the HVR1 region. Cross-reactive antibodies could be readily elicited following immunization of mice with multiple antigenic peptides carrying HVR1 sequences derived from our patients. The vigor and heterogeneity of cross-reactive antibody responses were significantly higher in patients with chronic hepatitis compared with those with acute hepatitis and in patients infected with HCV type 2 compared with patients infected with other viral genotypes (predominantly type 1), which suggest that higher time-related HVR1 sequence diversification previously described for type 2 may result from immune selection. The finding of a statistically significant correlation between HVR1 sequence variation, and intensity, and crossreactivity of humoral immune responses provided stronger evidence in support of the contention that HCV variant selection is driven by the host's immune pressure