Alberto Alberti

Revealing the History of Sheep Domestication Using Retrovirus Integrations

Sheep retroviruses can be used to map the selective preferences of early farmers and trace livestock movements across Europe. Not Just Dinner on Legs Several thousand years ago, human beings realized the virtues of domesticating wild animals as easy meat. Soon other possibilities became apparent, and as revealed in a series of papers in this issue, early pastoralists became selective about breeding for wool, leather, milk, and muscle power. In two papers, Gibbs et al. report on the bovine genome sequence (p. 522; see the cover, the Perspective by Lewin, and the Policy Forum by Roberts) and trace the diversity and genetic history of cattle (p. 528), while Chessa et al. (p. 532) survey the occurrence of endogenous retroviruses in sheep and map their distribution to historical waves of human selection and dispersal across Europe. Finally, Ludwig et al. (p. 485) note the origins of variation in the coat-color of horses and suggest that it is most likely to have been selected for by humans in need of good-looking transport. The domestication of livestock represented a crucial step in human history. By using endogenous retroviruses as genetic markers, we found that sheep differentiated on the basis of their “retrotype” and morphological traits dispersed across Eurasia and Africa via separate migratory episodes. Relicts of the first migrations include the Mouflon, as well as breeds previously recognized as “primitive” on the basis of their morphology, such as the Orkney, Soay, and the Nordic short-tailed sheep now confined to the periphery of northwest Europe. A later migratory episode, involving sheep with improved production traits, shaped the great majority of present-day breeds. The ability to differentiate genetically primitive sheep from more modern breeds provides valuable insights into the history of sheep domestication.

Recommended nomenclature for zeolite minerals: report of the subcommittee on zeolites of the International Mineralogical Association, Commission on New Minerals and Mineral Names

Abstract This report embodies recommendations on zeolite nomenclature approved by the International Mineralogical Association Commission on New Minerals and Mineral Names. In a working definition of a zeolite mineral used for this review, interrupted tetrahedral framework structures are accepted where other zeolitic properties prevail, and complete substitution by elements other than Si and Al is allowed. Separate species are recognized in topologically distinctive compositional series in which different extra-framework cations are the most abundant in atomic proportions. To name these, the appropriate chemical symbol is attached by a hyphen to the series name as a suffix except for the names harmotome, pollucite and wairakite in the phillipsite and analcime series. Differences in space- group symmetry and in order-disorder relationships in zeolites having the same topologically distinctive framework do not in general provide adequate grounds for recognition of separate species. Zeolite species are not to be distinguished solely on Si : Al ratio except for heulandite (Si : Al < 4.0) and clinoptilolite (Si : Al ≥ 4.0). Dehydration, partial hydration, and over-hydration are not sufficient grounds for the recognition of separate species of zeolites. Use of the term ‘ideal formula’ should be avoided in referring to a simplified or averaged formula of a zeolite. Newly recognized species in compositional series are as follows: brewsterite-Sr, -Ba; chabazite-Ca, - Na, -K; clinoptilolite-K, -Na, -Ca; dachiardite-Ca, -Na; erionite-Na, -K, -Ca; faujasite-Na, -Ca, -Mg; ferrierite-Mg, -K5 -Na; gmelinite-Na, -Ca, -K; heulandite-Ca, -Na, -K5 -Sr; levyne-Ca, -Na; paulingite- K, -Ca; phillipsite-Na, -Ca, -K; stilbite-Ca, -Na. Key references, type locality, origin of name, chemical data, IZA structure-type symbols, space-group symmetry, unit-cell dimensions, and comments on structure are listed for 13 compositional series, 82 accepted zeolite mineral species, and three of doubtful status. Herschelite, leonhardite, svetlozarite, and wellsite are discredited as mineral species names. Obsolete and discredited names are listed.

Removal of sulfonamide antibiotics from water: Evidence of adsorption into an organophilic zeolite Y by its structural modifications

Sulfonamide antibiotics are persistent pollutants of aquatic bodies, known to induce high levels of bacterial resistance. We investigated the adsorption of sulfadiazine, sulfamethazine, and sulfachloropyridazine sulfonamides into a highly dealuminated faujasite zeolite (Y) with cage window sizes comparable to sulfonamide dimensions. At maximal solubility the antibiotics were almost completely (>90%) and quickly (t<1min) removed from the water by zeolite. The maximal amount of sulfonamides adsorbed was 18-26% DW of dry zeolite weight, as evidenced by thermogravimetric analyses and accounted for about one antibiotic molecule per zeolitic cage. The presence of this organic inside the cage was revealed by unit cell parameter variations and structural deformations obtained by X-ray structure analyses carried out using the Rietveld method on exhausted zeolite. The most evident deformation effects were the lowering of the Fd-3m real symmetry in the parent zeolite to Fd-3 and the remarkable deformations which occurred in the 12-membered ring cage window after sulfadiazine or sulfachloropyridazine adsorption. After sulfamethazine adsorption, zeolite deformation caused a lowering in symmetry up to the monoclinic P2/m space group. The effective and irreversible adsorption of sulfonamides into organophylic Y zeolite makes this cheap and environmentally friendly material a suitable candidate for removing sulfonamides from water.

The crystal structure refinement of a natural mordenite

AbstracL The crystal structure of natural mordenite from Elba (Italy) with chemical formula (Nai.49K2.8oMgo.o4Ca2.osSro.osXAl8.98Si39.i3)096 • 29.07HjO was refined in its hydrated form up to a wR value of Si2%. Systematic absences were consistent with the Cmcm space group but the asymmetry of the extraframework ions indicated as more probable the acentric subgroup Cmc2i. Consequently the atom 08 is no longer set on an inversion center and the T—08—T angle is not constrained to 180°. The Si/Al distribution is partially ordered, with an enrichment of AI in the tetrahedra of the four-membered ring. All Ca ions are localized in a eightcoordinated site; K ions altemate with water molecules in a six-coordinated Site.

Equine and canine Anaplasma phagocytophilum strains isolated on the island of Sardinia (Italy) are phylogenetically related to pathogenic strains from the United States

ABSTRACT The presence of Anaplasma phagocytophilum, a tick-transmitted zoonotic pathogen, was investigated in Sardinia using a molecular approach. Phylogenetic analysis revealed that Sardinian strains are genetically distinct from the two lineages previously described in Europe and are closely related to strains isolated in different areas of the United States.

Location of Brønsted sites in mordenite

Crystal structure refinements of mordenites indicate that partial (Si,Al) order in the tetrahedral sites regularly recurs within the observed range (6–9) Al/unit cell. Consequently, for a given Si/Al ratio, it is possible to determine the maximum number of OH groups that can be allocated on each framework oxygen. Assuming that only one proton can be bonded at the same time to the oxygens of a tetrahedron, structural data indicate that it is highly probable that Bronsted sites are on framework oxygens 02 and 07, heading toward the center of the 12-ring, and on 09, heading toward the center of the 8-ring, each with about the same population. The intensities of the i.r. stretching bands (around 3,600 cm−1 wavenumbers) of the hydroxyls Si(OH)Al agree well with this result.

Position of cations and water molecules in hydrated chabazite. Natural and Na-, Ca-, Sr- and K-exchanged chabazites

Crystal structures of natural and hydrated Na, Ca, Sr and K-exchanged chabazite from Keller (Germany) were refined at room temperature in the R 3 m space group. The most probable distribution of ions indicates the presence of four cation sites; one at the centre of the hexagonal prism, two in the large cage along the [111] diagonal, and the fourth near the 8-ring window which is split into two sites close to each other in the monovalent exchanged forms. The site at the centre of the D 6 R is empty in the Na and K-exchanged chabazites. In this last form one of the two sites along [111] is also empty. Water molecules are spread over a large number of sites, one with 100% occupancy, at the centre of the 8-ring window, the others, normally with low occupancy, inside the large cage. Occupancies of both cation and water molecule sites vary greatly in the different forms.

Crystal structure of the zeolite mutinaite, the natural analog of ZSM-5

We describe the crystal structure of the high-silica zeolite mutinaite, recently found at Mt. Adamson (Northern Victoria Land, Antarctica). Mutinaite is the natural counterpart of the synthetic zeolite ZSM-5. The new mineral, (Na 2.76 K 0.11 Mg 0.21 Ca 3.78 ) (Al 11.20 Si 84.91 ) · 6O H 2 O H 2 O, is orthorhombic, space group Pnma, with a = 20.201(2), b = 19.991(2), and c = 13.469(2) A. A single-crystal X-ray diffraction experiment was performed at the synchrotron radiation source ESRF (Grenoble). No Si-Al order in the framework has been detected. Large distances between ions in the channels and framework oxygens suggest weak interactions between the framework and extraframework species.

Molecular Investigation and Phylogeny of Anaplasma spp. in Mediterranean Ruminants Reveal the Presence of Neutrophil-Tropic Strains Closely Related to A. platys

ABSTRACT Few data are available on the prevalence and molecular typing of species belonging to the genus Anaplasma in Mediterranean ruminants. In this study, PCR analysis and sequencing of both 16S rRNA and groEL genes were combined to investigate the presence, prevalence, and molecular traits of Anaplasma spp. in ruminants sampled on the Island of Sardinia, chosen as a subtropical representative area. The results demonstrate a high prevalence of Anaplasma spp. in ruminants, with animals infected by at least four of six Anaplasma species (Anaplasma marginale, A. bovis, A. ovis, and A. phagocytophilum). Moreover, ruminants host a number of neutrophil-tropic strains genetically closely related to the canine pathogen A. platys. The high Anaplasma spp. prevalence and the identification of as-yet-unclassified neutrophil-tropic strains raise concerns about the specificity of serological tests routinely used in ruminants and provide additional background for reconstructing the evolutionary history of species genetically related to A. phagocytophilum.

Structural modifications induced by dehydration in the zeolite gismondine

Abstract Gismondine from Montalto di Castro, Italy [Ca3.91Al7.77Si8.22O32·17.57 H2O], a = 10.0199(4), b = 10.6373(5), c = 9.8316(5) A , β = 92.561(6)°, space group P21/c, dehydrated in vacuum for 1 and 24 h and transformed into two new phases, here called gismondine (1 h) and gismondine (24 h), respectively. Gismondine (1 h) is characterized by 9.5% water loss and by a small decrease in the cell volume (ΔV = 0.6%); cell parameters are a = 9.989(3), b = 10.616(3), c = 9.820(3) A , and β = 92.57(2)°. The framework is almost undistorted, but a rearrangement of water molecules causes a change in space group to P21, with formation of a more regular 6-coordinated Ca polyhedron. The final Rw value (isotropic displacement factors) is 7.6%. Gismondine (24 h) is characterized by the orthorhombic space group P212121 and a unit cell doubled with respect to the nondehydrated sample; cell parameters are a = 13.902(9), b = 8.892(4), and c = 13.952(5) A . More than 50% of water is lost, the framework is highly distorted, and the channels are strongly squashed. Residual water sites are fully occupied. Ca polyhedra are seven-fold coordinated and are linked by vertices to form infinite chains. The final Rw value (isotropic displacement factors) is 7.6%.