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Ingvarsson and Hollobaugh (2011) investigated tact- or echoic-to-intraverbal transfer of stimulus control to "wh" questions for three preschool-aged boys with autism. The current study was a systematic replication of this study with an adolescent girl with Down syndrome. A multi-element design was used to compare the effectiveness and efficiency of picture or echoic prompts presented on an iPad or in vivo to teach "wh" questions. All prompt conditions were effective. Conclusions and recommendations for practice are presented.

Understanding aquifer architecture is critical for managing groundwater resources in western Canada. Recent regulations have yielded abundant new gamma-ray well-log data from the principal aquifer in Alberta, the Paleocene Paskapoo Formation. A major obstacle to utilizing this data is the fact that gamma-ray measurements in the shallow subsurface are made through surface casing, which suppresses gamma-ray readings and effectively prohibits stratigraphic characterization. Here we describe and demonstrate a relatively simple and efficient method for normalizing gamma-ray data from stratigraphic horizons that are behind surface casing and apply this method to the Paskapoo Formation in west-central Alberta. The gamma-ray normalization procedure adjusts the cased gamma-ray values so that high and low percentile values of the resulting gamma-ray statistical distribution are equal to those of the non-cased values. The effectiveness of this procedure is demonstrated by comparing the normalized gamma-ray values from cased intervals with those from nearby wells without casing. Good matches between these wells, as well as the transition between normalized curves at the base of cased zones and the gamma-ray curves at the uppermost portion of uncased zones, suggest this methodology is effective for studying the Paskapoo Formation. The normalized curve allows cased and uncased intervals to be correlated, enabling improved stratigraphic characterization and mapping of fluvial sand bodies behind surface casing. This new data provides the framework for better characterization of aquifer dimensions and the derivation of stratigraphic parameters used to constrain hydrogeological models and enhance groundwater recovery. Pour gerer les ressources d'eau souterraine dans l'Ouest canadien, il est essentiel de comprendre l'architecture des aquiferes. De recentes reglementations ont permis d'obtenir de grandes quantites de donnees de diagraphie de puits par carottage au rayonnement gamma sur le principal aquifere de l'Alberta, la Formation de Paskapoo (Paleocene). Un des principaux obstacles a l'utilisation de ces donnees est le fait que les mesures par rayonnement gamma a de faibles profondeurs sous la surface sont effectuees a travers le tubage de surface, ce qui supprime les lectures de rayonnement gamma et empeche une caracterisation stratigraphique efficace. Dans le present article, nous decrivons et demontrons une methode relativement simple et efficace de normalisation des donnees de rayonnement gamma des horizons stratigraphiques qui se trouvent derriere le tubage de surface et nous appliquons cette methode a la Formation de Paskapoo dans le centre-ouest de l'Alberta. La procedure de normalisation du rayonnement gamma ajuste les valeurs 'encaissees'de rayonnement gamma afin que les valeurs percentiles, basses et elevees, de la distribution resultante de rayonnement gamma soient egales a celles des valeurs non'encaissees'. L'efficacite de cette procedure est demontree en comparant les valeurs de rayonnement gamma normalisees des intervalles encaisses a celles provenant de puits avoisinants sans tubage. En raison des bonnes concordances entre ces puits, et la transition entre les courbes normalisees a la base des zones encaissees et les courbes de rayonnement gamma a la partie superieure des zones non encaissees, cette methode serait efficace pour etudier la Formation de Paskapoo. La courbe normalisee permet la correlation des intervalles encaisses et des intervalles non encaisses, ce qui conduit a une amelioration de la caracterisation stratigraphique et de la cartographie des amas de sable fluvial a l'arriere du tubage de surface. Ces nouvelles donnees fournissent le cadre pour une meilleure caracterisation des dimensions des aquiferes et le calcul de parametres stratigraphiques utilises pour contraindre les modeles hydrogeologiques et rehausser la recuperation d'eau souterraine. [Traduit par la Redaction], Introduction The Western Canadian Sedimentary Basin (WCSB) of Alberta, Canada (Fig. 1), is one of the most intensely explored regions in North America, with thousands of new wells being drilled [...]

In classic Hodgkin lymphoma (HL) and posttransplantation lymphoproliferative disease (PTLD), 2 malignancies frequently associated with Epstein-Barr virus (EBV), the tumor cells often appear to derive from B-cell receptor (BCR)-deficient and therefore preapoptotic germinal center (GC) B cells. To test whether EBV can rescue BCR-less GC B cells, we infected human tonsillar CD77+ GC B cells in vitro with EBV. More than 60 monoclonal lymphoblastoid cell lines (LCLs) were established. Among these, 28 cell lines did not express surface immunoglobulin (sIg). Two of the sIg-negative cell lines carry obviously destructive mutations that have been introduced into originally functional V(H) gene rearrangements during the process of somatic hypermutation. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) showed that in most other lines the sIg deficiency was not simply the result of transcriptional down-regulation, but it was rather due to posttranscriptional defects. These findings strongly support the idea that EBV plays a central role in the pathogenesis of classic HL and PTLD by rescuing BCR-deficient, preapoptotic GC B cells from apoptosis, and that EBV infection renders the cells independent from survival signals normally supplied by a BCR. The monoclonal LCLs represent valuable models for early stages of lymphoma development in classic HL and PTLD.

Primary lymphomas of the central nervous system (PCNSLs) were investigated for their capacity to perform further maturation steps. We studied a series of 11 PCNSLs derived from immunocompetent patients for immunoglobulin (Ig) class switch recombination (CSR) by performing reverse transcriptase-polymerase chain reaction (RT-PCR) for transcripts of Ig constant region gene segments (IGHC). This analysis revealed exclusive transcription of IgM and IgD mRNA in the absence of IgG, IgA, or IgE transcription. This finding was corroborated at the protein level by the immunohistochemical demonstration of IgM on the surface of the tumor cells. The unexpected lack of CSR may be due to internal switch mu region deletions, which were detected in 7 of 11 cases. We also found that expression of activation-induced cytidine deaminase (AID), which is required for CSR and somatic hypermutation, was detectable by RT-PCR in 4 of 10 cases and by immunohistochemistry in one of three cases analyzed. This may indicate that ongoing somatic mutation, which is often observed in PCNSL, could be due to sustained AID expression in a fraction of cases and that intraclonal V gene diversity may occur in other cases at an earlier phase of tumor clone expansion, when AID may have been expressed.

A cell line, RTL-W1, has been developed from the normal liver of an adult rainbow trout by proteolytic dissociation of liver fragments. RTL-W1 can be grown routinely in the basal medium, L-15, supplemented with 5% fetal bovine serum. In this medium, the cells have been passaged approximately 100 times over an 8-year period. The cells do not form colonies or grow in soft agar. The cultures are heteroploid. The cell shape was predominantly polygonal or epithelial-like, but as cultures became confluent, bipolar or fibroblast-like cells appeared. Among the prominent ultrastructural features of RTL-W1 were distended endoplasmic reticulum and desmosomes. Benzo[a]pyrene was cytotoxic to RTL-W1. Activity for the enzyme, 7-ethoxyresorufin O-deethylase (EROD), which is a measure of the cytochrome P4501A1 protein, increased dramatically in RTL-W1 upon their exposure to increasing concentrations of either beta-naphthoflavone (BNF) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). With these properties, RTL-W1 should be useful for studying the expression of the cytochrome P450 enzymes and as a tool for assessing the toxic potency of environmental contaminants.

On the basis of reports of rat mammary- and pancreas-tumor models, we hypothesized that an increase in consumption of linoleic acid (LA) would also cause an enhancement in mouse skin-tumor promotion. SEN-CAR mice were placed on diets containing 0.8%, 2.2%, 3.5%, 4.5%, 5.6%, 7.0%, or 8.4% LA, 1 week after initiation with 7,12-dimethylbenz(a)anthracene and 3 weeks before starting promotion with 12-O-tetradecanoylphorbol-13-acetate. An inverse correlation (r = -0.92) was observed between papilloma number and level of LA; however, there was little difference in tumor incidence. A relationship between diet and carcinoma incidence was also found. The fatty acid composition of epidermal phospholipids reflected the dietary LA levels. 12-O-Tetradecanoylphorbol-13-acetate-induced epidermal prostaglandin E2 levels generally decreased with increasing dietary LA. To determine whether this inverse correlation between dietary LA and tumor yield was due to species differences or organ-model differences, a mammary carcinogenesis experiment was performed. SENCAR mice were fed the 0.8%, 4.5%, and 8.4% LA diets. All mice received 6 mg 7,12-dimethylbenz(a)anthracene, administered intragastrically at 1 mg/week. Tumor appearance was delayed in the 0.8% LA diet group, and a positive dose-response relationship between dietary LA and mammary-tumor incidence was observed. These studies suggest that the effect of dietary LA on tumor development is target tissue specific rather than species specific.

We recently reported (J. Leyton et al., Cancer Res., 51: 907-915, 1991) an inverse correlation between skin tumor number and level of dietary linoleic acid (LA) in SENCAR mice following an initiation-promotion protocol. These results differed from the reported (C. Ip et al., Cancer Res., 45: 1997-2001, 1985) positive correlation between dietary LA and tumor incidence for the rat mammary gland. The goal of the study reported here was to determine whether this dissimilarity was due to organ site or species differences. Female SENCAR mice were fed 1 of 3 15% fat diets containing LA at levels of 0.8, 4.5, and 8.4% before, during, and after intragastric administration of 6 mg (1 mg/week) 7,12-dimethylbenz(a)anthracene. A positive correlation between level of dietary LA and mammary tumor incidence was observed such that for the first 15 weeks, the incidence was greatest in the 8.4% LA diet group, followed by the 4.5% and then the 0.8% LA groups. Distinct dietary effects on latency were also noted in that 15, 12, and 8 weeks after cessation of 7,12-dimethylbenz(a)anthracene were required for a 40% carcinoma incidence in the 0.8, 4.5, and 8.4% LA diet groups, respectively. A histopathological analysis of all tumors revealed that the predominant type was the adenosquamous carcinoma, which comprised 46.6, 54.1, and 77.7% of all mammary tumors for diets containing 0.8, 4.5, and 8.4% LA, respectively. The second most common tumor was the adenocarcinoma type B, which was found with a frequency of 33% in the 0.8% and 4.5% LA diet groups and 22% in the 8.4% LA diet group. These results indicate that SENCAR mice have a short latency period for 7,12-dimethylbenz(a)anthracene-induced mammary tumor development and that rat and mouse mammary tumor development is modified by dietary LA in a similar manner, although in the SENCAR mouse dietary LA did not have a saturating effect. In addition, high dietary LA was found to be associated specifically with an increased incidence of adenosquamous carcinomas but not of other types of mammary tumors.

Based on the biological activity of arachidonic acid metabolites, we hypothesized that alterations in the consumption of linoleic acid, the precursor to arachidonic acid, would result in a modification in tumor development when fed during the tumor promotion stage of the mouse skin initiation-promotion model. The effects of seven different levels of dietary linoleic acid (LA), supplied as corn oil in a 15% fat diet, on the incidence and rate of papilloma and carcinoma development were determined. SENCAR mice were placed on one of the experimental diets, containing 1.0, 3.6, 6.0, 7.9, 9.9, 12.5, or 15.0% corn oil, 1 week after initiation with 10 nmol of 7,12-dimethylbenz(a)anthracene and 3 weeks prior to the start of twice weekly promotion with 1 micrograms 12-O-tetradecanoylphorbol-13-acetate (TPA). At 15 weeks of TPA treatment there were significant differences in papilloma number among diet groups, such that an inverse correlation (r = 0.92) was observed between tumor number and level of corn oil; the lowest corn oil diet group had an average of 11.7 tumors/mouse, while the highest corn oil group had 5.4 tumors/mouse. However, there was little difference in tumor incidence among diet groups. A general relationship between diet and carcinoma incidence was also found, such that the highest corn oil diet group had the lowest carcinoma incidence. In an experiment performed with DBA/2 mice, the average number of papillomas/mouse at 17 weeks was 4.5 (1.0% corn oil), 5.6 (7.9%) corn oil), and 2.3 (15.0% corn oil). Papilloma incidence was also affected by diet, with a 79% incidence for the 15.0% corn oil and an incidence of 93% for the 1.0% corn oil group. analyses of the fatty acid composition of epidermal phospholipids in mice fed the experimental diets reflected the dietary LA levels, in that an accumulation of phospholipid LA, accompanied by an overall decrease in arachidonic acid, occurred with increasing dietary corn oil. In spite of the high membrane levels of LA, no measurable amount of epidermal conjugated dienes of LA could be detected. Epidermal prostaglandin E2 levels in acetone-treated mice were similar for all diet groups (approximately 3 pg/micrograms DNA). However, 6 h after topical application with 4 micrograms of TPA, prostaglandin E2 levels were elevated 5- to 10-fold; an inverse correlation (P less than 0.05) was seen with increasing dietary LA, although the concordance with decreased phospholipid arachidonic acid was not strong.(ABSTRACT TRUNCATED AT 400 WORDS)

A comprehensive ultrastructural analysis of sporulation and parasporal crystal development is described for Bacillus thuringiensis. The insecticidal crystal of B. thuringiensis is initiated at the start of engulfment and is nearly complete by the time the exosporium forms. The crystal and a heretofore unobserved ovoid inclusion develop without any clear association with the forespore septum, exosporium, or mesosomes. These observations contradict previous hypotheses that the crystal is synthesized on the forespore membrane, exosporium, or mesosomes. Formation of forespore septa involves densely staining, double-membrane-bound, vesicular mesosomes that have a bridged appearance. Forespore engulfment is subpolar and also involves mesosomes. Upon completion of engulfment and the following cytoplasmic changes occur: decrease in electron density of the incipient forespore membrane; loss of bridged appearance of incipient forespore membrane; change in stainability of incipient forespore, forespore, and mother cell cytoplasms; and alteration in staining quality of plasma membrane. These changes are involved in the conversion of the incipient forespore into a forespore and reflect "commitment" to sporulation.

Transmission electron micrographs of glutaraldehyde- OsO(4)-fixed Rhizobium trifolii 0403 before and after cells were treated with 16.6 mM succinate showed that treated cells increased in mass by increasing cytoplasmic volume. The morphology of succinate-treated cells was identical to that of bacteroids, and the appearances of the envelope and periplasmic space were similar. The primary difference was in inclusion number and type.