Conserved noncoding sequences (CNSs) in DNA are reliable pointers to regulatory elements controlling gene expression. Using a comparative genomics approach with four dicotyledonous plant species (Arabidopsis thaliana, papaya [Carica papaya], poplar [Populus trichocarpa], and grape [Vitis vinifera]), we detected hundreds of CNSs upstream of Arabidopsis genes. Distinct positioning, length, and enrichment for transcription factor binding sites suggest these CNSs play a functional role in transcriptional regulation. The enrichment of transcription factors within the set of genes associated with CNS is consistent with the hypothesis that together they form part of a conserved transcriptional network whose function is to regulate other transcription factors and control development. We identified a set of promoters where regulatory mechanisms are likely to be shared between the model organism Arabidopsis and other dicots, providing areas of focus for further research.

Background and Purpose— Transesophageal echocardiography (TEE) is the gold standard for the diagnosis of a patent foramen ovale in adults. In children, acoustic windows on transthoracic echocardiography (TTE) are better than in adults; thus, an invasive TEE may not be necessary. Our goal was to assess the validity of TTE with agitated saline injection for the diagnosis of a patent foramen ovale in children using TEE as the gold standard. Methods— Fifty consecutive pediatric patients >1 year of age referred for TEE were prospectively enrolled. Imaging included 2-dimensional, color Doppler, and agitated saline contrast injections with and without Valsalva by TTE followed by TEE. Interpreters of the TTE were blinded to TEE results. Studies were categorized as “inconclusive” if the TTE images were inadequate for definitive diagnosis by the blinded interpreter. Results— TTE results were considered conclusive in 43 of 50 (86%) patients. Among the 43 conclusive studies, the 2 modalities disagreed in 1 patient. TTE had a positive predictive value of 100%, negative predictive value 97%, sensitivity of 88%, and specificity of 100% for detecting a patent foramen ovale. Conclusions— TTE with agitated saline injection is diagnostic for the assessment of atrial septal integrity in the majority of children.

Background: The echocardiographic diagnosis of anomalous left coronary artery from the pulmonary artery (ALCAPA) can be challenging. The aim of this study was to assess the hypothesis that diagnosis can be enhanced by using supplemental oxygen, which decreases pulmonary vascular resistance and increases retrograde flow from the coronary artery into the pulmonary artery.Methods: Demographic, echocardiographic, and cardiac catheterization data were reviewed in patients presenting with ALCAPA from 1999 to 2007.Results: Twenty-one patients (seven male; median age, 5 months) presented with ALCAPA. Nine underwent imaging with oxygen. Two of these nine (22%) had previous standard echocardiographic studies that missed the diagnosis. Cardiac catheterization was required for diagnosis of ALCAPA in 42% of patients who underwent standard echocardiography compared with 11% of patients who received supplemental oxygen in addition to standard echocardiography. The administration of oxygen caused no significant change in heart rate or cardiorespiratory support.Conclusion: Transient oxygen administration is useful in the noninvasive diagnosis of ALCAPA. (J Am Soc Echocardiogr 2010;23:1099-102.)

We isolated and characterized a Brassica C genome-specific CACTA element, which was designated Bot1 (Brassica oleracea transposon 1). After analysing phylogenetic relationships, copy numbers and sequence similarity of Bot1 and Bot1 analogues in B. oleracea (C genome) versus Brassica rapa (A genome), we concluded that Bot1 has encountered several rounds of amplification in the oleracea genome only, and has played a major role in the recent rapa and oleracea genome divergence. We performed in silico analyses of the genomic organization and internal structure of Bot1, and established which segment of Bot1 is C-genome specific. Our work reports a fully characterized Brassica repetitive sequence that can distinguish the Brassica A and C chromosomes in the allotetraploid Brassica napus, by fluorescent in situ hybridization. We demonstrated that Bot1 carries a host S locus-associated SLL3 gene copy. We speculate that Bot1 was involved in the proliferation of SLL3 around the Brassica genome. The present study reinforces the assumption that transposons are a major driver of genome and gene evolution in higher plants.

We have investigated the copy numbers and genomic organization of five representative reverse transcriptase domains from retrotransposons in Brassica oleracea. Two non-homologous Pseudoviridae (Ty1/copia-like) elements, two Metaviridae (Ty3/gypsy-like) elements (one related to the Athila family) and one Retroposinae (LINE) element were hybridized to a gridded BAC library, "BoB". The results indicated that the individual LTR retrotransposons (copia and gypsy-like) were represented by between 90 and 320 copies in the haploid genome, with only evidence of a single location for the LINE. Sequence analysis of the same elements against genome survey sequence gave estimates of between 60 and 570, but no LINE was found. There was minimal evidence for clustering between any of these retroelements: only half the randomly expected number of BACs hybridized to both LTR-retrotransposon families. Fluorescent in situ hybridization showed that each of the retroelements had a characteristic genomic distribution. Our results suggest there are preferential sites and perhaps control mechanisms for the insertion or excision of different retrotransposon groups.

Traditional clinical psychology generally posits “mental” events that differ from “behavioral” events. Mental events are not publicly observable, take place in a different dimension from overt behavior, and are the topic of primary concern. For example, mental events are often taken to be causes of troublesome overt behavior. In addition, the mental events themselves may be regarded as troublesome, independent of their relation to any specific overt behavior. Therapy is usually aimed at fixing these troublesome mental events, under an assumption that improvement in the client’s status will follow in due course. Behavior analysis has its own position on the relations among clinical matters, overt behavior, and such private events as thinking and feeling. In a behavior-analytic view, private events are behavioral phenomena rather than mental phenomena. They are not initiating causes of behavior; rather, they are themselves caused by antecedent conditions, but they may contribute to discriminative control over subsequent behavior, both verbal and nonverbal. Verbal processes are viewed as vitally important in understanding troublesome behavior. However, the circumstances that cause both the troublesome private events and the troublesome behavior in the first place still need to be addressed. Finally, clinical behavior analysis will need to market its insights into diagnosis and treatment very adroitly, because it rejects the mentalism upon which most traditional forms of therapy are predicated and the mentalism that most consumers expect to encounter.

Three experiments used pigeons in an autoshaping procedure and a single-subject design to examine compound stimulus control in classical conditioning. Experiment 1 examined the blocking effect, and Experiment 2 examined the unblocking effect. In both experiments, response-independent food was first delivered intermittently in the presence of one distinctively colored houselight but not another. Then, conventional autoshaping trials were carried out in the presence of each houselight. In Experiment 1, the keylight readily elicited responding in the presence of the houselight that had been negatively correlated with food, but not in the presence of the houselight that had been positively correlated with food. In Experiment 2, the keylight readily elicited responding in the presence of the houselight positively correlated with food, but only when the amount of food used on the autoshaping trials was either greater or less than that previously delivered in the presence of the houselight. Experiment 3 examined the overexpectation effect. Conventional autoshaping trials were first carried out by presenting each of two keylights individually. Then, additional autoshaping trials were carried out by presenting the two keylights as a compound, with either the same amount of food or a greater amount of food per trial. Finally, the keylights were retested by again presenting them individually. The number of responses per trial elicited by the keylights decreased when the amount of food used in compound trials was the same as that used in individual trials. However, the number of responses per trial remained approximately the same when the amount of food used in compound trials was greater than that used in individual trials. Taken together, the results of the three experiments demonstrate (a) the generality of the blocking, unblocking, and overexpectation effects by virtue of their extension to appetitive unconditioned stimuli; (b) the suitability of pigeons as subjects and autoshaping as a procedure for studying classical conditioning; and (c) the appropriateness of single-subject designs.

Wilms' tumor is a childhood nephroblastoma that is postulated to arise through the inactivation of a tumor suppressor gene by a two-hit mechanism. A candidate 11p13 Wilms' tumor gene, WT1, has been cloned and shown to encode a zinc finger protein. Patients with the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities, and mental retardation) have a high risk of developing Wilms' tumor and they carry constitutional deletions of one chromosome 11 allele encompassing the WT1 gene. Analysis of the remaining WT1 allele in a Wilms' tumor from a WAGR patient revealed the deletion of a single nucleotide in exon 7. This mutation likely played a key role in tumor formation, as it prevents translation of the DNA-binding zinc finger domain that is essential for the function of the WT1 polypeptide as a transcriptional regulator. (C) 1993 Wiley-Liss, Inc.

Pigeons chose between two aperiodic, time-based schedules of reinforcement. The arithmetic mean interreinforcement interval of the first schedule was short, but the harmonic mean was long, whereas the arithmetic mean interreinforcement interval of the second schedule was long, but the harmonic mean was short. The pigeons preferred the schedule with the shorter harmonic mean in a concurrent-chains procedure when a terminal link ended after the first scheduled reinforcer had been gained on a terminal-link entry, but reversed their preferences, such that they preferred the schedule with the shorter arithmetic mean, when the terminal links ended after a fixed duration of exposure to the schedule. Moreover, the pigeons preferred the schedule with the shorter arithmetic mean in a two-key concurrent variable-interval variable-interval procedure, as well as in a concurrent variable-time variable-time, changeover-key procedure. The data suggest that an aggregate property of a schedule may not yield valid information about the responding that schedule will maintain as a choice alternative.

Pigeons chose between equivalent two-component mixed and multiple terminal-link schedules of reinforcement in the concurrent-chains procedure. The pigeons preferred the multiple schedule over the mixed when the components of the compound schedules were differentiated in terms of density of reinforcement, but the pigeons were indifferent when the components were differentiated in terms of number of reinforcers per cycle. Taken together, these results indicate that a local variable, the interval to the first reinforcer, but not a molar variable, the number of reinforcers, was sufficient to differentiate the components and thereby evoke preference.

Pigeons were trained on a two‐key concurrent schedule, where food reinforcers on one key were arranged by a simple variable‐interval schedule and on the other key by a chain variable‐interval variable‐interval schedule. When the initial link of the chain was in effect, the pigeons tended to respond more on the simple variable‐interval schedule, and hence less on the chain, than would be expected from a comparison of both the local and overall rates of reinforcement of the two schedules. When the terminal link of the chain was in effect, the pigeons responded more on the chain than would be expected from a comparison of the rates of reinforcement of the schedules then in effect. Overall responding on the chain was not proportional to overall reinforcement on the chain but rather was a by‐product of responding during initial‐ and terminal‐link phases.

In a concurrent‐chains procedure, pigeons chose between equivalent mixed and multiple fixed‐interval schedules of reinforcement. In the first experiment, preference for the multiple schedule was higher when the probability of the shorter fixed interval was less than .50 than for complementary points, an outcome consistent with the delay‐reduction hypothesis of conditioned reinforcement and observing, but inconsistent with the uncertainty‐reduction hypothesis which requires symmetrical preferences with a maximum when the two intervals are equiprobable. A second experiment assessed preference for equivalent mixed and multiple schedules when each choice outcome resulted in two reinforcements, one on the longer and one on the shorter fixed interval. The order of the two fixed intervals was determined probabilistically. Pigeons again preferred multiple to mixed schedules, although multiple‐schedule preference did not vary systematically with the likelihood of the shorter fixed interval occurring first. The results from these choice procedures are consistent with those from the observing‐response literature in suggesting that the strength of a stimulus cannot be well described as a function of the degree of uncertainty reduction the stimulus provides about reinforcement.

Pigeons were exposed to the concurrent-chains procedure in two experiments designed to investigate the effects of unequal numbers of reinforcers on choice. In Experiment 1, the pigeons were indifferent between long and short durations of access to variable-interval schedules of equal reinforcement density, but preferred a short high-density terminal link over a longer, lower density terminal link, even though in both sets of comparisons there were many more reinforcers per cycle in the longer terminal link. In Experiment 2, the pigeons preferred five reinforcers, the first of which was available after 30 sec, over a single reinforcer available at 30 sec, but only when the local interval between successive reinforcers was short. The pigeons were indifferent when this local interval was sufficiently long. The pigeons' behavior appeared to be under the control of local terminal-link variables, such as the intervals to the first reinforcer and between successive reinforcers, and was not well described in terms of transformed delays of reinforcement or reductions in average delay to reinforcement.

Two experiments investigated the extent to which response contingencies influence the choice between two schedules of reinforcement by exposing pigeons to a concurrent‐chains procedure in which reinforcers in one terminal link were response‐independent, and in the other terminal link, response‐dependent. In Experiment 1, the pigeons were indifferent between an aperiodic, response‐independent schedule and an aperiodic, response‐dependent schedule that required a minimum rate of responding. This finding limits the generality of a required‐rate contingency as a determinant of choice, which contingency had been previously demonstrated in a context of periodic reinforcement to evoke preference for an alternate schedule. In Experiment 2, the pigeons preferred a periodic, response‐independent schedule to a periodic, response‐dependent schedule that shared a feature with a required‐rate schedule: there was a requirement to respond early in the interreinforcement interval, when responding produced reinforcement only later. The results of the two experiments suggest the following general interpretation: pigeons prefer a second schedule to the extent that the response contingencies of the first schedule must be satisfied during discriminable periods of nonreinforcement.