Štěpite, tetragonal U(AsO3 OH)2(H2O)4 (IMA 2012-006), is the first natural arsenate of tetravalent uranium. It occurs in the Geschieber vein, Jáchymov ore district, Western Bohemia, Czech Republic, as emerald-green crystallinecrusts on altered arsenic. Associated minerals include arsenolite, běhounekite, claudetite, gypsum, kaatialaite, the new mineral vysokýite (IMA 2012-067) and a partially characterized phase with the formula (H3O)+ 2(UO2)2(AsO4)2˙6H2O.Štěpite typically forms tabular crystals with prominent {001} and {010} faces, up to 0.6 mm in size. The crystals have a vitreous lustre and a grey to greenish grey streak. They are brittle with an uneven fracture and a very good cleavage on (001). Their Mohs hardness is about2. Štěpite is not fluorescent in either short-wave or long-wave ultraviolet light. It is biaxial (–) with refractive indices (at 590 nm) of α = 1.636(2), β = 1.667(3), γ = 1.672(2) and 2Vobs < ~5°, anomalous greyish to pale yellow interference colours, andno pleochroism. The composition is as follows: 0.12Na2O, 50.19 UO2, 0.04SiO4, 0.09 P2O5, 0.93 As2O5, 1.95 SO3, 16.41 H2O; total 107.90 wt.%, yielding an empirical formula (based on 12 Oa. p. f. u.) of (U1.01Na0.02)Σ1.03[(AsO3OH)1.82 (PO3OH)0.04(SO4)0.13(SiO4)0.01]Σ 2.00˙4H2O. Štěpite is tetragonal, crystallizingin space group I41 /acd, with a = 10.9894(1), c = 32.9109(6) Å, V = 3974.5(1) Å3,Z = 16 and Dcalc = 3.90 g cm-3. The six strongest peaks in the X-ray powder-diffraction pattern [d obs in Å (I) (hkl)] are as follows: 8.190(100)(004), 7.008(43)(112), 5.475(18)(200), 4.111(16)(008), 3.395(20)(312,217), 2.1543(25)(419). The crystal structure of šteěpite has been solved from singlecrystal X-ray diffraction data by the charge-flippingmethod and refined to R 1 = 0.0353 based on 1434 unique observed reflections, and to wR 2 = 0.1488 for all 1523 unique reflections. The crystal structure of štšpite consists of sheets perpendicular to [001], made up of eight-coordinate uraniumatoms and hydroxyarsenate 'tetrahedra'. The ligands surrounding the uranium atom consist of six oxygen atoms which belong to the hydroxyarsenate groups and two oxygen atoms which belong to interlayer H2 O molecules. Each UO8 polyhedron is connected to five other U polyhedravia six AsO3OH groups. Adjacent electroneutral sheets, of composition [U4+(AsO3OH)2 2-]0, are linked by hydrogen bonds involving H2 O molecules in the interlayers and OH groups in the sheets. The new mineral is named in honourof Josef Štěp (1863–1926), a Czech mining engineer and 'father' of the world's first radioactive spa at Jáchymov.

The 18O(p, α)15N reaction rate has been extracted by means of the Trojan-Horse method. For the first time the contribution of the 20-keV peak has been directly evaluated, giving a value about 35% larger than previously estimated. The present approach has allowed to improve the accuracy of a factor 8.5, as it is based on the measured strength instead of educated guesses or spectroscopic measurements. The contribution of the 90-keV resonance has been determined as well, which turned out to be of negligible importance to astrophysics.

Background: There is inadequate information regarding the neuropsychiatric aspect of Mild Cognitive Impairment (MCI).

Objective: To determine the neuropsychiatric profile of MCI, and compare this with normal controls and patients with mild Alzheimer's Disease (AD).

Design: Cross-sectional assessment of psychiatric symptoms in subjects that are enrolled in Mayo Clinic's longitudinal study of normal aging, MCI and dementia.

Methods and Participants: The Neuropsychiatric Inventory (NPI) was administered to normal control subjects, MCI subjects and patients with early AD. Individual NPI domain scores and total NPI scores were compared among the three groups after controlling for age, educational status, Dementia Rating Scale (DRS) and Mini-Mental State Examination (MMSE) scores. Statistical analysis was performed by utilizing ANOVA, χ2 and Fisher's exact test.

Results: Data were analyzed on 514 normal controls, 54 MCI subjects, and 87 subjects with mild AD (CDR of 0.5 or 1); females consisted of 60.3%, 53.7% and 57.5%; and, the average ages (SD) were 77.8 (1.95), 79 (4.6), 80.5 (14.6) respectively. ANOVA pair-wise comparison revealed that both MMSE and DRS differences among the three groups were significantly different at (p=0.05). The total NPI scores were significantly different (p=0.0001, F=107.93) among the three groups using ANOVA. Pair-wise comparison of individual behavioral domain of NPI showed statistically significant differences between MCI and normals; and MCI and AD (p=0.001). Group differences on NPI remained after controlling for age and education at p=0.0375 and p=0.0050 respectively.

Conclusion: The neuropsychiatric pattern is reminiscent of the clinical, neuroimaging and neuropsychological profile of MCI. It gives further credence to the view that MCI is indeed the gray zone, with overlap on both ends of the pole.