Chromosome analysis using different staining techniques and fluorescent in situ hybridization in Cerithium vulgatum (Gastropoda: Cerithiidae)

In the present paper one population of the "large" subtidal mollusc Cerithium vulgatum Bruguiere, 1792 (Gastropoda: Cerithiidae) from the Northwestern coast of Sicily was investigated from a karyological point of view. The chromosome complement was Giemsa stained, conventionally karyotyped in 18 homomorphic chromosome pairs (10 bi-armed and 8 mono-armed), and subsequently analysed using silver, CMA3 and DAPI staining, and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [ribosomal DNA (rDNA), (TTAGGG)n and (GATA)n]. FISH with the rDNA probe consistently mapped major ribosomal sites (18S-28S rDNA) in the terminal region of the short arms of one small sized mono-armed chromosome pair. Ribosomal DNA was transciptionally active as indicated by its preferential impregnation with silver nitrate (Ag-NOR) and did not contain a high amount of GC base pairs as suggested by the lack of a bright CMA3 fluorescence. The (TTAGGG)n telomeric probe was hybridized to the termini of nearly all chromosomes, thus demonstrating that, in C. vulgatum, this sequence has been conserved during the genomic evolution. The finding of the telomeric hexanucleotide in six species belonging to the three high taxa of Gastropoda supports the notion that this sequence is widespread within this class. The (GATA)n probe did not label any chromosome regions except for a minute terminal area of a single bivalent at pachytene stage

Impact of Cool Materials on Ambient Temperatures in an Urban Area

The urban heat island is a problem that affects our cities and results in a warmer climate in the urban and residential areas compared to the surrounding rural areas. One solution to this problem involves the use of materials with high solar reflectance and high thermal emissivity, the so-called “Cool Materials”. Their surface temperatures are much lower than those of typical building materials. Usually Cool Materials are used to decrease heat flow entering in a building, but if used on an urban scale, their lower surface temperature lead to a lower heat exchange between air and surfaces, helping to decrease the air temperature of the urban environment. The paper reports the results of a study carried out on a densely populated area in Rome of about 500.000 m2. The study was divided into three parts. The first part involves the comparison and the analysis of data collected by weather stations of airports and public agencies located both in urban areas and in peripheral areas in order to monitor the magnitude of the heat island effect. The second part includes measurements of the thermal properties of some Cool asphalts. The third part is focused on numerical analysis of the phenomenon through the creation of a model included in a S.V.A.T. software that allows to compare the outdoor air temperature of an area before and after a hypothetical use of Cool Materials on external surfaces of buildings and street pavements. The results of this study demonstrated the significant influence of cool materials on the reduction of the heat island phenomenon