WB-6a

Brown sediment with clasts ranging from small to large in size. Clast shape ranges from angular to sub-rounded. Necking structures are abundant within this sample, mainly between larger aggregates. Some rotation structures and lineations can also be seen. Comet structure and grain stacking can be seen in minor amounts.

WB-6b

Dark brown sediment with clasts ranging from small to large in size. Grain shape ranges from sub-angular to rounded. Rotation structures are common throughout the sample. Some necking structures are also present between large and medium sized aggregates. Lineations and grain stacks are also present in minor amounts.

WB-7b

Dark brown sediment with clasts ranging from small to large in size. The grains range from sub-angular to sub-rounded in shape. Rotation structures and necking structures can commonly be seen throughout. Lineations and comet structures can also be seen throughout the sample. Grain crushing can be seen in minor amounts in several areas.

WB-I

Dark brown sediment with two domains. One domain is fine grained, while the other is coarser grained. Clasts range from small to large, and sub-angular to sub-rounded in shape. The coarser domain contains lineations, comet structures and minor amounts of rotation structures. The fine grained domain is abundant with water escape structures. This sample also contains a few different areas of clay rich sediment.

Development of an AMR-ACB Array for Gastrointestinal Motility Studies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Measurement of beta (t -> Wb)/beta(t -> Wq) at root s=1.96 TeV

We present the measurement of R = B(t -> Wb)/B(t -> Wq) in pp collisions at root s = 1.96 TeV, using 230 pb(-1) of data collected by the DO experiment at the Fermilab Tevatron Collider. We fit simultaneously R and the number (N-tt) of selected top quark pairs (tt), to the number of identified b-quark jets in events with one electron or one muon, three or more jets, and high transverse energy imbalance. To improve sensitivity, kinematical properties of events with no identified b-quark jets are included in the fit. We measure R = 1.03(-0.17)(0.19) (stat + syst), in good agreement with the standard model. We set lower limits of R > 0.61 and vertical bar V-tb vertical bar > 0.78 at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.

Simultaneous measurement of the ratio R = B(t -> Wb)/B(t -> Wq) and the top-quark pair production cross section with the D0 detector at root s=1.96 TeV

We present the first simultaneous measurement of the ratio of branching fractions, R = B(t --> Wb)/B(t --> Wq), with q being a d, s, or b quark, and the top-quark pair production cross section sigma(t (t) over bar) in the lepton plus jets channel using 0.9 fb(-1) of p (p) over bar collision data at root s = 1.96 TeV collected with the D0 detector. We extract R and sigma(t (t) over bar) by analyzing samples of events with 0, 1, and >= 2 identified b jets. We measure R = 0.97(-0.08)(+0.09) (stat + syst) and sigma(t (t) over bar) = 8.18(-0.84)(+0.90) (stat + syst) +/- 0.50(lumi) pb, in agreement with the standard model prediction.

Precision Measurement of the Ratio B(t -> Wb)/B(t -> Wq) and Extraction of V-tb

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the ratio B(t -> Wb)/B(t -> Wq) in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development of an AMR-ACB Array for Gastrointestinal Motility Studies

The association between anisotropic magnetoresistive (AMR) sensor and AC biosusceptometry (ACB) to evaluate gastrointestinal motility is presented. The AMR-ACB system was successfully characterized in a bench-top study, and in vivo results were compared with those obtained by means of simultaneous manometry. Both AMR-ACB and manometry techniques presented high temporal cross correlation between the two periodicals signals (R = 0.9 +/- 0.1; P < 0.05). The contraction frequencies using AMR-ACB were 73.9 +/- 7.6 mHz and using manometry were 73.8 +/- 7.9 mHz during the baseline (r = 98, p < 0.05). The amplitude of contraction using AMR-ACB was 396 +/- 108 mu T.s and using manometry were 540 +/- 198 mmHg.s during the baseline. The amplitudes of signals for AMR-ACB and manometric recordings were similarly increased to 86.4% and 89.3% by neostigmine, and also decreased to 27.2% and 21.4% by hyoscine butylbromide in all animals, respectively. The AMR-ACB array is nonexpensive, portable, and has high-spatiotemporal resolution to provide helpful information about gastrointestinal tract.

In vitro effects of thiazolides on Giardia lamblia WB clone C6 cultured axenically and in coculture with Caco2 cells

The thiazolides represent a novel class of anti-infective drugs, with the nitrothiazole nitazoxanide [2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide] (NTZ) as the parent compound. NTZ exhibits a broad spectrum of activities against a wide variety of helminths, protozoa, and enteric bacteria infecting animals and humans. In vivo, NTZ is rapidly deacetylated to tizoxanide (TIZ), which exhibits similar activities. We have here comparatively investigated the in vitro effects of NTZ, TIZ, a number of other modified thiazolides, and metronidazole (MTZ) on Giardia lamblia trophozoites grown under axenic culture conditions and in coculture with the human cancer colon cell line Caco2. The modifications of the thiazolides included, on one hand, the replacement of the nitro group on the thiazole ring with a bromide, and, on the other hand, the differential positioning of methyl groups on the benzene ring. Of seven compounds with a bromo instead of a nitro group, only one, RM4820, showed moderate inhibition of Giardia proliferation in axenic culture, but not in coculture with Caco2 cells, with a 50% inhibitory concentration (IC50) of 18.8 microM; in comparison, NTZ and tizoxanide had IC50s of 2.4 microM, and MTZ had an IC50 of 7.8 microM. Moreover, the methylation or carboxylation of the benzene ring at position 3 resulted in a significant decrease of activity, and methylation at position 5 completely abrogated the antiparasitic effect of the nitrothiazole compound. Trophozoites treated with NTZ showed distinct lesions on the ventral disk as soon as 2 to 3 h after treatment, whereas treatment with metronidazole resulted in severe damage to the dorsal surface membrane at later time points.

Characterization of a Giardia lamblia WB C6 clone resistant to the isoflavone formononetin

Giardia lamblia is a common intestinal-dwelling protozoan and causes diarrhoea in humans and animals worldwide. For several years, a small number of drugs such as the 5-nitroimidazole metronidazole (MET) or the thiazolide nitazoxanide (NTZ) have been used for chemotherapy against giardiasis. However, various pre-clinical and clinical investigations revealed that antigiardial chemotherapy may be complicated by emergence of giardial resistance to these drugs. The present study addressed the question if isoflavones with antigiardial activity, such as daidzein (DAI) or formononetin (FOR), may serve as alternative compounds for treatment of giardiasis. For this purpose, the potential of G. lamblia clone WB C6 to form resistance to FOR and related isoflavones was tested in vitro. In the line of these experiments, a clone (C3) resistant to isoflavones, but sensitive to MET and NTZ, was generated. Affinity chromatography on DAI-agarose using cell-free extracts of G. lamblia trophozoites resulted in the isolation of a polypeptide of approximately 40 kDa, which was identified by mass spectrometry as a nucleoside hydrolase (NH) homologue (EAA37551.1). In a nucleoside hydrolase assay, recombinant NH hydrolysed all nucleosides with a preference for purine nucleosides and was inhibited by isoflavones. Using quantitative RT-PCR, the expression of genes that are potentially involved in resistance formation was analysed, namely NH and genes encoding variant surface proteins (VSPs, TSA417). The transcript level of the potential target NH was found to be significantly reduced in C3. Moreover, drastic changes were observed in VSP gene expression. This may indicate that resistance formation in Giardia against isoflavones is linked to, and possibly mediated by, altered gene expression. Taken together, our results suggest FOR or related isoflavones as an alternative antigiardial agent to overcome potential problems of resistance to drugs like MET or NTZ. However, the capacity of Giardia to develop resistance to isoflavones can potentially interfere with this alternative treatment of the disease.