Non-parametric error distribution analysis from the laboratory calibration of various rainfall intensity gauges.

The analysis of counting and catching errors of both catching and non-catching types of rain intensity gauges was recently possible over a wide variety of measuring principles and instrument design solutions, based on the work performed during the recent Field Intercomparison of Rainfall Intensity Gauges promoted by World Meteorological Organization (WMO). The analysis reported here concerns the assessment of accuracy and precision of various types of instruments based on extensive calibration tests performed in the laboratory during the first phase of this WMO Intercomparison. The non-parametric analysis of relative errors allowed us to conclude that the accuracy of the investigated RI gauges is generally high, after assuming that it should be at least contained within the limits set forth by WMO in this respect. The measuring principle exploited by the instrument is generally not very decisive in obtaining such good results in the laboratory. Rather, the attention paid by the manufacturer to suitably accounting and correcting for systematic errors and time-constant related effects was demonstrated to be influential. The analysis of precision showed that the observed frequency distribution of relative errors around their mean value is not indicative of an underlying Gaussian population, being much more peaked in most cases than can be expected from samples extracted from a Gaussian distribution. The analysis of variance (one-way ANOVA), assuming the instrument model as the only potentially affecting factor, does not confirm the hypothesis of a single common underlying distribution for all instruments. Pair-wise multiple comparison analysis revealed cases in which significant differences could be observed.

Tipping bucket mechanical errors and their influence on rainfall statistics and extremes.

Based on the error figures obtained after laboratory tests over a wide set of operational rain gauges from the network of the Liguria region, the bias introduced by systematic mechanical errors of tipping bucket rain gauges in the estimation of return periods and other statistics of rainfall extremes is quantified. An equivalent sample size is defined as a simple index that can be easily employed by practitioner engineers to measure the influence of systematic mechanical errors on common hydrological practice and the derived hydraulic engineering design. A few consequences of the presented results are discussed, with reference to data set reconstruction issues and the risk of introducing artificial climate trends in the observed rain records.

Screening for mutations of the APC gene in 66 Italian familial adenomatous polyposis patients: evidence for phenotypic differences in cases with and without identified mutation.

Germline mutations in the APC gene are responsible for familial adenomatous polyposis (FAP), a dominantly inherited syndrome characterized by the development of hundreds to thousands of polyps in the colon and in the rectum of affected individuals and by variable extracolonic manifestations (gastric and duodenal polyps, osteomas, retinal lesions, and desmoid tumors). Through the combined use of single-strand conformation polymorphism (SSCP) analysis and the protein truncation test (PTT), we have screened 66 Italian FAP patients and found 29 different APC mutations in a total of 34 cases. Of the identified mutations, 15 were nonsense, 12 were 1- to 5-bp deletions or insertions and two were complex rearrangements, all leading to the formation of premature stop codons. Only 10 mutations had been already previously described at the germline level, confirming the high heterogeneity of the APC mutational spectrum. The mean age of diagnosis in mutation positive cases and their affected relatives was significantly lower than in cases without identified mutation (30.6 vs 39.1 years, respectively; p = 0.003). In addition, among patients without a family history of polyposis, all mutation-positive cases displayed at least one of the extracolonic manifestations usually associated with FAP, whereas in one-half of the cases without identified mutation, none of these phenotypes was observed. Although a fraction of apparently mutation-negative cases were likely to be due to limitations of the mutation screening strategy, our results suggest, in agreement with previous reports, that allelic and/or genetic heterogeneity might be responsible for the phenotypic variability observed in FAP patients.

Characterization of ten novel and 13 recurring BRCA1 and BRCA2 germline mutations in Italian breast and/or ovarian carcinoma patients. Mutations in brief no. 178. Online.

Germline mutations in the BRCA1 and BRCA2 genes are associated with approximately 80% of families with a high incidence of breast and/or ovarian cancers (OMIM database reference numbers: 113705, 600185). Furthermore, constitutional mutations in the these genes have been reported in women with early-onset breast carcinoma and without family history of cancer. We analyzed by protein truncation test (PTT) and single strand conformation polymorphism (SSCP) followed by sequence analysis, BRCA1 exons 11 and 20 and BRCA2 exons 10 and 11 in 142 Italian cancer patients. These included six male breast cancer cases, 61 women with breast carcinoma diagnosed before 36 years old and selected independently of family history of breast cancer and 75 familial breast and/or ovarian cancer patients. In a previous report, we described 11 different BRCA1 mutations in a subset of 70 cases. Here, we report the characterization of 23 additional mutations, 14 in BRCA1 and 9 in BRCA2, subsequently identified. Ten mutations were not previously described, while the other 13 were recurrent. Of the 61 women with early-onset breast cancer, 11 carried a germline mutation in BRCA1 (18.0%) and four in BRCA2 (6.6%). These frequencies indicate that BRCA1/BRCA2 genetic tests should be advised to women with breast cancer diagnosed at early age, independently of family history of cancer.

MADS box genes expressed in developing inflorescences of rice and sorghum.

With the aim of elucidating the complex genetic system controlling flower morphogenesis in cereals, we have characterized two rice and two sorghum MADS box genes isolated from cDNA libraries made from developing inflorescences. The rice clones OsMADS24 and OsMADS45, which share high homology with the Arabidopsis AGL2 and AGL4 MADS box genes, are expressed in the floral meristem, in all the primordia, and in mature floral organs. High expression levels have also been found in developing kernels. The sorghum clone SbMADS1 is also homologous to AGL2 and AGL4: expression analysis and mapping data suggest that it is the ortholog of OsMADS24. The pattern of expression of SbMADS2, the other sorghum MADS box gene, suggests that it may play a role as a meristem identity gene, as does AP1 in Arabidopsis, to which it shows considerable homology. The four genes have been mapped on a rice RFLP genetic map: the results are discussed in terms of synteny among cereals.