The effect of stimulus distribution form on the acquisition and rate of conditioned responding: implications for theory.

In four experiments rats were conditioned to an auditory conditioned stimulus (conditioned stimulus; CS) that was paired with food, and learning about the CS was compared across two conditions in which the mean duration of the CS was equated. In one, the CS was of a single, fixed duration on every trial, and in the other the CS duration was drawn from an exponential distribution, and hence changed from trial to trial. Higher rates of conditioned responding to the fixed than to the variable stimulus were observed, in both between- (Experiment 1) and within-subject designs (Experiments 2 and 3).

Determination of priority pollutants in aqueous samples by dispersive liquid-liquid microextraction.

A dispersive liquid-liquid microextraction (DLLME) method followed by high-performance liquid chromatography-triple quadrupole mass spectrometry has been developed for the simultaneous determination of linear alkylbenzene sulfonates (LAS C10, C11, C12, and C13), nonylphenol (NP), nonylphenol mono- and diethoxylates (NP1EO and NP2EO), and di-(2-ethylhexyl)phthalate (DEHP). The applicability of the method has been tested by the determination of the above mentioned organic pollutants in tap water and wastewater. Several parameters affecting DLLME, such as, the type and volume of the extraction and disperser solvents, sample pH, ionic strength and number of extractions, have been evaluated.

Translocation of PKC by yessotoxin in an in vitro model of Alzheimer's disease with improvement of tau and β-amyloid pathology.

Yessotoxin is a marine phycotoxin that induces motor alterations in mice after intraperitoneal injection. In primary cortical neurons, yessotoxin treatment induced a caspase-independent cell death with an IC50 of 4.27 nM.

An extension of the Rescorla and Wagner Simulator for context conditioning.

This paper introduces R&W Simulator version 4, which extends previous work by incorporating context simulation within standard Pavlovian designs. This addition allows the assessment of: (1) context-stimulus competition, by treating contextual cues as ordinary background stimuli present throughout the whole experimental session; (2) summation, by computing compound stimuli with contextual cues as an integrating feature, with and without the addition of specific configural cues; and (3) contingency effects in causal learning. These new functionalities broaden the range of experimental designs that the simulator is able to replicate, such as some recovery from extinction phenomena (e.

Chronic acetaminophen exposure in pediatric acute liver failure.

Background: Acetaminophen (N-acetyl-p-aminophenol [APAP]) is a widely used medication that can cause hepatotoxicity. We examined characteristics and outcomes of children with chronic exposure (CE) to APAP in the multinational Pediatric Acute Liver Failure (PALF) Study.

Methods: A total of 895 children enrolled from 2002 to 2009 were grouped by APAP exposure history as: CE (received multiple doses \x{2265}2 days; n = 83), single dose exposure (SE; n = 85), and no exposure (NE; n = 498).

Feasibility of automated rhythm assessment in chest compression pauses during cardiopulmonary resuscitation.

Aim: To demonstrate the feasibility of doing a reliable rhythm analysis in the chest compression pauses (e.g. pauses for two ventilations) during cardiopulmonary resuscitation (CPR).

Evaluation of clinical and immunological markers for predicting virological failure in a HIV/AIDS treatment cohort in Busia, Kenya.

Background: In resource-limited settings where viral load (VL) monitoring is scarce or unavailable, clinicians must use immunological and clinical criteria to define HIV virological treatment failure. This study examined the performance of World Health Organization (WHO) clinical and immunological failure criteria in predicting virological failure in HIV patients receiving antiretroviral therapy (ART).

Methods: In a HIV/AIDS program in Busia District Hospital, Kenya, a retrospective, cross-sectional cohort analysis was performed in April 2008 for all adult patients (>18 years old) on ART for ≥12 months, treatment-naive at ART start, attending the clinic at least once in last 6 months, and who had given informed consent.

Formation of water polyhedrons in propofol-water clusters.

Following previous structural investigations on the hydrated clusters of the anesthetic propofol we analyze here the spectroscopy of propofol·(H(2)O)(7-9) in supersonic expansions, to approach to the solution limit. Using 2-color REMPI the mass-resolved electronic spectrum of each solvated species was obtained. The UV/UV hole burning demonstrated the presence of at least two conformers for propofol·(H(2)O)(7) and propofol·(H(2)O)(8), while a single conformer was observed for propofol·(H(2)O)(9).

Underuse of radiotherapy in lung cancer has negative consequences for patients.

Introduction: Radiotherapy has proven to be an effective treatment when used alone or with other therapies. However, underuse of radiotherapy has been observed in various studies. The objective of this investigation was to assess the use of radiotherapy as initial treatment for lung cancer in a southern region of Europe.

Differential regulation of CDK5 and c-Fos expression by morphine in the brain of Lewis and Fischer 344 rat strains.

The aim of this study was to comparatively study cyclin-dependent kinase 5 (CDK5) and c-Fos regulation by morphine in the brains of Lewis and Fischer 344 (F344) rats, which are known to differ in their behavioral sensitivities to several drugs of abuse. Two hours after an acute i.p.

Epigenetic profile in chronic lymphocytic leukemia using methylation-specific multiplex ligation-dependent probe amplification.

Aim: To analyze the methylation status of 35 tumor suppressor genes using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in chronic lymphocytic leukemia (CLL).

Materials & Methods: The DNA of 37 samples from patients with CLL, six healthy donors, and Jurkat and Ramos cell lines was analyzed by MS-MLPA.

Results: Our results confirm that hypermethylation is a common and not randomly distributed event in CLL, and some genes, such as WT1, CDH13, IGSF4/TSLC1, GATA5, DAPK1 and RARB, are hypermethylated in more than 25% of the analyzed samples.

Platinum availability for future automotive technologies.

Platinum is an excellent catalyst, can be used at high temperatures, and is stable in many aggressive chemical environments. Consequently, platinum is used in many current industrial applications, notably automotive catalytic converters, and prospective vehicle fuel cells are expected to rely upon it. Between 2005 and 2010, the automotive industry used approximately 40% of mined platinum.

Benefit of 13-desmethyl spirolide C treatment in triple transgenic mouse model of Alzheimer disease: beta-amyloid and neuronal markers improvement.

Spirolides are marine toxins that are not currently in the routine monitoring assays. Nicotinic receptors seem to be the target of these compounds making them a promising pharmacological tool for related diseases as dementias as previously shown in vitro. In the present work, the bioavailability of 13-desMethyl spirolide C (13-desMeC) in the brain and in vivo effects were tested.

Simple and fast calculation of the second-order gradients for globalized dual heuristic dynamic programming in neural networks.

We derive an algorithm to exactly calculate the mixed second-order derivatives of a neural network's output with respect to its input vector and weight vector. This is necessary for the adaptive dynamic programming (ADP) algorithms globalized dual heuristic programming (GDHP) and value-gradient learning. The algorithm calculates the inner product of this second-order matrix with a given fixed vector in a time that is linear in the number of weights in the neural network.

Influenza A H1N1/2009 infection in pediatric solid organ transplant recipients.

Aim And Method: The aim of this study was to describe the clinical characteristics and outcome of pandemic influenza A H1N1/2009 (pH1N1) infection, in a retrospective cohort of pediatric patients with kidney and/or liver transplant and confirmed pH1N1 infection from June to December 2009, diagnosed in 2 Spanish teaching hospitals.

Results: Forty-nine patients were included. Pneumonia was diagnosed in 4 patients (8.

Essential components of transition to adult transplant services: the transplant coordinators' perspective.

Context: Medical and surgical advancements have resulted in improved long-term survival of pediatric liver transplant recipients. As pediatric patients approach school age and adolescence, transplant centers are challenged to facilitate the process of transitioning from pediatric to adult centers.

Objective: To describe pediatric and adult liver transplant coordinators' perspective regarding practice for transitioning patients to adult-oriented transplant centers.

Long-term changes in pulmonary function after incidental lung irradiation for breast cancer: a prospective study with 7-year follow-up.

Purpose: To evaluate late pulmonary function changes after incidental pulmonary irradiation for breast cancer.

Methods And Materials: Forty-three consecutive female patients diagnosed with breast carcinoma and treated with postoperative radiation therapy (RT) at the same dose (50 Gy) and fractionation (2 Gy/fraction, 5 days/week) were enrolled. Pulmonary function tests (PFT) and ventilation/perfusion scans were performed before RT and 6, 12, 24, and 84 months afterward.

Special issue on computational models of classical conditioning guest editors' introduction.

In the present special issue, the performance of current computational models of classical conditioning was evaluated under three requirements: (1) Models were to be tested against a list of previously agreed-upon phenomena; (2) the parameters were fixed across simulations; and (3) the simulations used to test the models had to be made available. These requirements resulted in three major products: (a) a list of fundamental classical-conditioning results for which there is a consensus about their reliability; (b) the necessary information to evaluate each of the models on the basis of its ordinal successes in accounting for the experimental data; and (c) a repository of computational models ready to generate simulations. We believe that the contents of this issue represent the 2012 state of the art in computational modeling of classical conditioning and provide a way to find promising avenues for future model development.

Structure-anti-leukemic activity relationship study of ortho-dihydroxycoumarins in U-937 cells: key role of the δ-lactone ring in determining differentiation-inducing potency and selective pro-apoptotic action.

Previous studies indicated the need of at least one phenolic hydroxyl group in the coumarin core for induction of cytotoxicity in different cell lines. Herein, we present an exhaustive structure-activity relationship study including ortho-dihydroxycoumarins (o-DHC) derivatives, cinnamic acid derivatives (as open-chain coumarin analogues) and 1,2-pyrones (representative of the δ-lactone ring of the coumarin core), carried out to further identify the structural features of o-DHC required to induce leukemic cell differentiation and apoptosis in U-937 cells. Our results show for the first time that the δ-lactone ring positively influences the aforementioned biological effects, by conferring greater potency to compounds with an intact coumarin nucleus.

Effect of gambierol and its tetracyclic and heptacyclic analogues in cultured cerebellar neurons: a structure-activity relationships study.

The polycyclic ether class of marine natural products has attracted the attention of researchers due to their complex and large chemical structures and diverse biological activities. Gambierol is a marine polycyclic ether toxin, first isolated along with ciguatoxin congeners from the dinoflagellate Gambierdiscus toxicus. The parent compound gambierol and the analogues evaluated in this work share the main crucial elements for biological activity, previously described to be the C28=C29 double bond within the H ring and the unsaturated side chain [Fuwa, H.

Incremental value of global longitudinal strain for predicting early outcome after cardiac surgery.

Aims: Global longitudinal strain (GLS) seems accurate for detecting subclinical myocardial dysfunction, and may therefore be used to improve risk stratification for cardiac surgery.

Methods And Results: Longitudinal strain (by two-dimensional speckle tracking) was computed in 425 patients [mean age 67 ± 13 years, 69% male, left ventricular ejection fraction (LVEF) 51 ± 13%] referred for cardiac surgery [isolated coronary artery bypass graft (CABG) (n = 155), aortic valve surgery (n = 174), mitral surgery (n = 96)]. GLS (global-ε) was assessed for predicting early postoperative death.