The role of oxygen vacancies on the structure and the density of states of iron doped zirconia

In this paper we study, both with theoretical and experimental approach, the effect of iron doping in zirconia. Combining density functional theory (DFT) simulations with the experimental characterization of thin films, we show that iron is in the Fe3+ oxidation state and accordingly that the films are rich in oxygen vacancies (VO). VO favor the formation of the tetragonal phase in doped zirconia (ZrO2:Fe) and affect the density of state at the Fermi level as well as the local magnetization of Fe atoms. We also show that the Fe(2p) and Fe(3p) energy levels can be used as a marker for the presence of vacancies in the doped system. In particular the computed position of the Fe(3p) peak is strongly sensitive to the VO to Fe atoms ratio. A comparison of the theoretical and experimental Fe(3p) peak position suggests that in our films this ratio is close to 0.5. Besides the interest in the material by itself, ZrO2:Fe constitutes a test case for the application of DFT on transition metals embedded in oxides. In ZrO2:Fe the inclusion of the Hubbard U correction significantly changes the electronic properties of the system. However the inclusion of this correction, at least for the value U = 3.3 eV chosen in the present work, worsen the agreement with the measured photo-emission valence band spectra.Comment: 24 pages, 8 figure

Exploiting magnetic properties of Fe doping in zirconia

In this study we explore, both from theoretical and experimental side, the effect of Fe doping in ZrO2 (ZrO2:Fe). By means of first principles simulation we study the magnetization density and the magnetic interaction between Fe atoms. We also consider how this is affected by the presence of oxygen vacancies and compare our findings with models based on impurity band and carrier mediated magnetic interaction. Experimentally thin films (~ 20 nm) of ZrO2:Fe at high doping concentration are grown by atomic layer deposition. We provide experimental evidence that Fe is uniformly distributed in the ZrO2 by transmission electron microscopy and energy dispersive X-ray mapping, while X-ray diffraction evidences the presence of the fluorite crystal structure. Alternating gradient force magnetometer measurements show magnetic signal at room temperature, however with low magnetic moment per atom. Results from experimental measures and theoretical simulations are compared.Comment: 8 pages, 9 figures. JEMS 201

The genetic variability of the Podolica cattle breed from the Gargano area. Preliminary results

The Podolica cattle breed is autochthonous of Southern Italy and denoted by its particular rusticity. This study presents the preliminary results of the genetic characterization of the Podolica breed using DNA STR markers. A total of 20 microsatellite loci were analysed in 79 individuals reared in the Gargano area. Number of polymorphisms, allele fre- quencies, deviations from Hardy-Weinberg proportions, linkage disequilibrium between loci and genetic similarities between animals were calculated. The results showed a high deficiency of heterozygotes, the observed mean of het- erozygosis being 0.449, whereas the expected mean was 0.766. Many markers showed also deviations from the Hardy- Weinberg proportions and significant linkage disequilibrium between loci. However the genetic similarity within the pop- ulation was low (0.281) and the average number of alleles per locus was high (10), representing a high genetic vari- ability. In order to explain these results, a stratification of the breed in sub-populations with a high interior genetic homo- geneity but markedly differentiated one from each other could be hypothesized; this situation probably derived from non- random mating within each herd (consanguinity) and from the lack of exchange of genetic material between the herds. A further study is needed on a wider sample and extending the analysis to FAO-ISAG microsatellite panel in order to con- firm this hypothesis. This could eventually provide the information necessary for the correct management of the repro- ductive schemes and for genomic traceability of meat production

Analisi della variabilità genetica in una popolazione ovina di razza massese e studio di associazione con parametri di qualità del latte

RIASSUNTO Il presente lavoro ha come obiettivo la ricerca di associazioni tra marcatori microsatellite e la composizione chimica del latte. È stato condotto uno studio su 68 pecore di razza Massese provenienti da un allevamento toscano. A partire da latte fresco, sono stati valutati: composizione chimica standard, contenuto in caseina e frazioni caseiniche, proteine seriche, pH e parametri reologici. I capi sono stati sottoposti a genotipizzazione impiegando 17 marcatori microsatellite; sono, quindi, stati calcolati i valori di similarità genetica tra individui ed alcuni parametri genetici classici. Il numero medio di alleli per locus è risultato pari a 7,18 e l’eterozigosità osservata presentava variazioni tra 0,403 e 0,867 (media 0,677). La similarità genetica tra individui era 0,460. Cinque marcatori (BM8124, CSN3, BM1258, BMS468 e TGLA387) hanno mostrato una deviazione significativa dalle proporzioni di Hardy- Weinberg. Lo studio ha messo in evidenza alcuni microsatelliti con alleli significativamente associati a caratteri di composizione del latte (P<0,01). In particolare, la significatività più alta (P<0,001) è stata osservata per l’associazione dell’allele 2 del marcatore OIFNG con la a-lattoalbumina, dell’allele 10 del marcatore BL4 con il livello di immunoglobuline, dell’allele 2 del marcatore BMC1009 con il contenuto di grasso e dell’allele 9 del marcatore ILSTS42 con il parametro a30. Sono necessari ulteriori approfondimenti al fine di convalidare i risultati preliminari ottenuti nel presente lavoro e si rende necessaria l’estensione dello studio ad un numero maggiore di soggetti e la tipizzazione di un numero maggiore di loci, principalmente sui cromosomi 3 e 20 dove mappano i marcatori risultati più interessanti nella presente analisi. SUMMARY Current research aims to establish statistical associations between DNA microsatellites and milk chemical composition. Atrial was carried out on 68 Massese ewes reared in a farm of the Tuscany. The following parameters were evaluated on fresh milk: standard chemical composition, casein and its fractions, whey proteins, pH and rheological parameters. Animals were genotyped at 17 microsatellite loci. Genetic similarities among individuals and classical genetic parameters were evaluated. For each locus, average values of considered parameters were calculated in all the subjects carrying a given allele; these were compared statistically with the average values of subjects not carrying the allele, and the significance of the difference was estimated. The average number of alleles per locus resulted 7.18 and the observed heterozygosity ranged from 0.403 to 0.867 (0.677 medium value). The genetic similarity among individuals was 0.460. Five markers pointed out a significant deviation from the Hardy-Weinberg proportions (BM8124, CSN3, BM1258, BMS468 and TGLA387). The study revealed several microsatellites with alleles significantly linked to milk composition traits (P<0.01). In particular the highest significance (P<0.001) has been found for the allele 2 of OIFNG marker with a-lactoalbumin, for the allele 10 of the BL4 marker with immunoglobulins, for the allele 2 of BMC1009 with fat, and for allele 9 of ILSTS42 with a30. Further analyses are needed to validate these preliminary results, in particular increasing the number of subjects and of typed loci above all on the chromosomes 3 and 20 where the more interesting markers map

Genetic variability of three local cattle breeds (Calvana, Pontremolese, Garfagnina) by STR analysis

AbstractThe dramatic size contraction of local cattle breeds due to replacement with cosmopolite improved breeds highlights the need for native genetic resources conservation. In 1985, the Anagraphic Register of local cattle breeds and small-size ethnic groups was established by the Italian Ministry of Agriculture and Forestry. Calvana, Pontremolese and Garfagnina are among the included breeds. They are all native from Tuscany. Present breeding area covers the provinces of Firenze, Prato, Pistoia and Siena for the Calvana breed (around 280 heads), while it is restricted to the province of Lucca for both Garfagnina (around 180 heads) and Pontremolese. This latter breed consists, nowadays, of less than 40 heads, while being around 15000 in 1940s.The characterization of the genetic structure and variability via molecular markers could provide useful information for breed management and conservation. In the present study, a total of 149 animals, evenly distributed among the three breeds, were genetically char..

Soy isoflavones, inulin, calcium, and vitamin D3 in post-menopausal hot flushes: an observational study.

Purpose of investigation To evaluate the effect of soy isoflavones and inulin (SII) on hot flushes (HF) and quality of life in a clinical setting, the authors conducted an observational study. Materials and methods The authors performed an observational, prospective, multicentric study on women in peri-/post-menopause treated or untreated with a product present on the Italian market, consisting in a mixture of calcium (500 mg), vitamin D3 (300 IU), inulin (3 g) and soy isoflavones (40 mg). Results A total of 135 patients, 75 (55.6%) in the SII group and 60 (44.4%) in the untreated group entered the study. After three months, the mean number of HF declined of 2.8 (SD 3.7) in the SII group and 0.0 in the untreated one. The corresponding values after six months were -3.7 (SD 2.7) in the SII group and -0.9 (SD 5.3) in the control group (p = 0.02). Conclusion This observational trial suggests a possible beneficial effect of a dietary soy supplement containing 40 mg of isoflavone/day plus inulin in the management of menopausal symptoms such as hot flashes

Localisation-to-delocalisation transition of moir\'{e} excitons in WSe2_2/MoSe2_2 heterostructures

Moir\'{e} excitons (MXs) are electron-hole pairs localised by the periodic (moir\'{e}) potential forming in two-dimensional heterostructures (HSs). MXs can be exploited, $e.g.$, for creating nanoscale-ordered quantum emitters and achieving or probing strongly correlated electronic phases at relatively high temperatures. Here, we studied the exciton properties of a WSe$_2$/MoSe$_2$ HS from $T$=6 K to room temperature using time-resolved and continuous-wave micro-photoluminescence, also under magnetic field. The exciton dynamics and emission lineshape evolution with temperature show clear signatures that MXs de-trap from the moir\'{e} potential and turn into free interlayer excitons (IXs) at $T\gtrsim$120 K. The MX-to-IX transition is also apparent from the exciton magnetic moment reversing its sign when the moir\'{e} potential is not capable to localise excitons at elevated temperatures. Concomitantly, the exciton formation and decay times reduce drastically. Thus, our findings establish the conditions for a truly confined nature of the exciton states in a moir\'{e} superlattice with increasing temperature