Search results for "biologia"
showing 10 items of 2476 documents
Il Microbiota delle piante, ovvero le piante hanno bisogno dei microrganismi
2017
Le relazioni tra le piante e i fattori ambientali (il clima, i nutrienti, l’acqua, la composizione del suolo, etc) sono da tempo ampiamente studiate. Resta invece ancora molto da capire sul ruolo che la componente biologica del suolo (ci sono oltre cento milioni di cellule microbiche in un grammo di suolo!) ha sullo sviluppo e la salute delle piante. Nella rizosfera soprattutto (la porzione di suolo influenzata dalla presenza di radici), gli essudati radicali favoriscono lo sviluppo di microrganismi (batteri, funghi, protozoi, virus) che interagiscono con le radici e con il suolo nell’influenzare i processi di trasformazione ed assorbimento dei nutrienti, la crescita della pianta e le infez…
The impact of weather and the phase of the rodent cycle on breeding populations of waterbirds in Finnish Lapland
2016
Climate change may affect bird populations both directly by changing the weather conditions, and indirectly through changes in the food chain. While both theoretical and empirical studies have shown climate change having drastic impacts on polar areas, its consequences on Arctic bird species are still poorly known. Here we investigated how weather and changes in predator–prey interactions affected the annual growth rates of sub-Arctic birds by monitoring the breeding numbers of three duck and seven wader species in the alpine tundra of Finnish Lapland during 2005–2015 (except for 2006). We hypothesized that growth rates of waterbirds would be positively associated with warm and dry weather …
NMR-based quantification of rosmarinic and carnosic acids, GC-MS profile and bioactivity relevant to neurodegenerative disorders of Rosmarinus offici…
2013
Abstract A comparative study of phytochemicals content and biological properties of eight Rosmarinus officinalis (rosemary) populations (RO1–RO8) collected in different areas of Tunisia was carried out. Two of the main rosemary constituents, rosmarinic and carnosic acids, were quantified by an NMR technique. Carnosic acid content was higher than that of rosmarinic acid. The non-polar constituents were examined by GC and GC–MS. Total phenols and flavonoids content were also determined in order to discuss the possible correlation between these phytochemicals and bioactivity. Antioxidant activity was investigated through different in vitro assays. Sample RO3 from a sub-humid area showed the hi…
Olfactory cues and the value of information : Voles interpret cues differently based on recent predator encounters
2018
Prey strategically respond to the risk of predation by varying their behavior while balancing the tradeoffs of food and safety. We present here an experiment that tests the way the same indirect cues of predation risk are interpreted by bank voles, Myodes glareolus, as the game changes through exposure to a caged weasel. Using optimal patch use, we asked wild-caught voles to rank the risk they perceived. We measured their response to olfactory cues in the form of weasel bedding, a sham control in the form of rabbit bedding, and an odor-free control. We repeated the interviews in a chronological order to test the change in response, i.e., the changes in the value of the information. We found…
SEA URCHIN RESEARCH: MILESTONES, MEMORIES, AND FUTURE CHALLENGES
2017
The sea urchin eggs and embryos have been used for nearly two centuries as experimental models for classical and modern developmental biology. In the late 1870s, the ground-breaking observations independently obtained by Hertwig and Fol highlighted for the first time that a single sperm enters the oocyte and the male and female pronuclei fuse at fertilization.1 From that point on, the seminal studies of Boveri, Driesch, and Herbst allowed conceptualization of basic biological themes, such as the chromosome theory of heredity.2 In the first half of the twentieth century, the embryo manipulation experiments performed by Hörstadius and Runnström further advanced the field, introducing the conc…
Arti decorative tra scienza e restauro
2010
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The Paracentrotus lividus metallothionein gene family: structure and expression.
2014
Metallothioneins are metal binding proteins that play a pivotal role in metal homeostasis and detoxification. Since their initial discovery, they have been extensively studied in a variety of organisms ranging from microbes to plants and animals. Organisms often possess multiple genes encoding metallothionein homologs with distinct properties, such as varying affinities for different metals, and in many cases different functions. Despite the plethora of available studies, very little information is known about sea urchin P. lividus MT (1, 2). We previously identified five Pl-MT embryonic cDNAs and we studied their induction after cadmium treatment (3). Now we studied their expression during…
cis-Regulation and chromatin dynamics of the hbox12 gene during the embryogenesis of Paracentrotus lividus.
2014
The GRN specifying the dorsal-ventral (D-V) axis of the sea urchin embryo is currently under investigation. An early input for D-V polarity is given by a redox gradient probably generated by an asymmetrical distribution of maternal mitochondria (1). Only on the future ventral side, the oxidizing environment induces the expression of the nodal gene, an essential regulator of D-V polarization (2). By contrast, on the future dorsal side, a reducing environment activates the hypoxia inducible factor (HIF-1α) (3). The hbox12 transcription repressor is an early marker of the dorsal side of the embryo, in which it negatively regulates the expression of nodal (4, 5). Interestingly, by in silico ana…
Genome wide mapping of the MBF-1 binding sites during embryogenesis of the sea urchin reveals it is a chromatin organizer.
2015
The Zinc-finger MBF1 factor is a transcription activator involved in the expression of the early histone genes during development of the sea urchin embryo (1). The DNA-binding domain of MBF1 shares high sequence similarity with that of the CTCF chromatin organizer but, unexpectedly, extensive in silico analysis failed to identify the sea urchin CTCF ortholog (2, 3). This led us to speculate that MBF1 could have co-opted the function of CTCF during evolution of the echinoderms. To support this hypothesis, we performed the genome-wide MBF1-binding sites mapping in the P. lividus genome, by chromatin immunoprecipitation coupled to next generation sequencing (ChIP-Seq). We observed that MBF1 bi…