Fragmentation and splitting of the Gamow-Teller (GT) strength has been observed in a systematic study of the ( He, t) charge-exchange reaction at E( He)=200 MeV over the entire range of stable Sn isotopes. Triton energy spectra were observed with a high-resolution magnetic spectrometer at angles near 8 = 0 where AL = 0 transitions are enhanced. Excitation energies, widths, 0 cross sections, and strengths B(GT) were determined. A theoretically predicted configuration splitting of the main Gamow-Teller component into two components, expected to be dominant near A =118 at the onset of the filling of the 1611'2 neutron orbital, could not be observed. This may be due to the fact that the total widths of the resonances of 5 -6 MeV exceed the predicted splitting. A comparison of the 0' cross sections for the transitions to the Gamow-Teller resonances and the isobaric analog states leads to strengths B(GT) for the main Gamow-Teller components of typically 65%%up of the sumrule value of 3(N -Z). Three to four additional Gamow-Teller fragments ("pygmy resonances") were observed in all final nuclei at lower excitation energies. The excellent energy resolution of the experiment made it possible to observe a pronounced fine structure in these low-lying resonances which is believed to be due to coupling to two-particletwo-hole doorway states. Also seen with all target nuclei was a systematic sequence of strong J =1+ states near the ground states in all Sb isotopes (E = 0 to 220 keV). In addition, strong AI = 1 resonances were observed in all nuclei

The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure.

Rhesus macaques are commonly used as a translational animal model in neuroimaging and neurodevelopmental research. In this report, we present longitudinal data from both structural and diffusion MRI images generated on a cohort of 34 typically developing monkeys from 2 weeks to 36 months of age. All images have been manually skull stripped and are being made freely available via an online repository for use by the research community.

Increasing reports of blooms of the blue -green alga Cylindrospermopsis raciborskii C. ) ( ) raciborskii , which contains the hepatotoxic alkaloid cylindrospermopsin CYN , have led to public health concerns in Australia. The toxicology of CYN appears complex and is still being elucidated. We have utilized the combination of sensitivity and specificity afforded by coupling high performance liquid ( ) ( ) chromatography HPLC to a tandem mass spectrometer MS / MS to produce an assay which is suitable for monitoring low CYN concentrations in water samples. Intact algal cells in the water sample ( ) are lysed by a freeze -thaw cycle. After filtration 0.45 m filter , 110 L is injected. The HPLC uses an ( ) Altima C18 250 = 4.6 mm, 5 m column at 40ЊC. Chromatography utilizes a linear gradient from 1 to 60% methanol over 5 min, with a final isocratic stage holding at 60% methanol for 1 min. The mobile ( ) phase is buffered to 5 mM with ammonium acetate. The transition from the M + H ion 416 m / z to the [ 194 m / z fragment is monitored. Linearity of this assay is 1 -600 g / L peak area= 304 = CYN Ž ) 2 ( )] g/L y 569; r = 1.000 n = 7 . Using a single point standard curve, total coefficients of variation were 26.4, 10.5, 12.6, and 10.7% at 0.78, 5.2, 104, and 1040 g / L. This assay is utilized in conjunction with algal cell counts and mouse bioassays to monitor water bodies for public health purposes. The rationale used in employing these methods is discussed.

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