Herpes Simplex Virus-1 ICP27 Nuclear Export Signal Mutants Exhibit Cell Type-Dependent Deficits in Replication and ICP4 Expression.

Herpes simplex virus type-1 (HSV-1) protein ICP27 is an essential immediate early (IE) protein that promotes the expression of viral early (E) and late (L) genes via multiple mechanisms. Our understanding of this complex regulatory protein has been greatly enhanced by the characterization of HSV-1 mutants bearing engineered alterations in the ICP27 gene. However, much of this analysis has been performed in interferon-deficient Vero monkey cells.

Avian H7N9 influenza viruses are evolutionarily constrained by stochastic processes during replication and transmission in mammals.

H7N9 avian influenza viruses (AIVs) have caused over 1,500 documented human infections since emerging in 2013. Although wild-type H7N9 AIVs can be transmitted by respiratory droplets in ferrets, they have not yet caused widespread outbreaks in humans. Previous studies have revealed molecular determinants of H7N9 AIV host switching, but little is known about potential evolutionary constraints on this process.

Functional comparison of herpes simplex virus 1 (HSV-1) and HSV-2 ICP27 homologs reveals a role for ICP27 in virion release.

Unlabelled: Numerous studies have focused on the regulatory functions of ICP27, an immediate-early (IE) protein of herpes simplex virus 1 (HSV-1). However, its homolog in HSV-2, termed ICP27t2, has been little studied. Here, we used two different approaches to functionally compare ICP27t2 and ICP27.

Potential interaction between the volatile and non-volatile fractions on the in vitro antimicrobial activity of three South African Pelargonium (Geraniaceae) species.

Previous studies have reported promising antimicrobial efficacy for the essential oils and solvent extracts of several indigenous Pelargonium species. This study aimed to determine if any pharmacological interaction (e.g.

Endovascular histologic effects of ultrathin gold- or vitronectin-coated platinum aneurysm coils in a rodent arterial occlusion model: a preliminary investigation.

Background And Purpose: Novel stratagems to improve the efficacy of platinum coils in occluding cerebral aneurysms have primarily involved coating coils with materials thought likely to provoke more desirable histologic reactions. No investigations to date, however, have evaluated the utility of gold or vitronectin coatings, despite known endovascular histologic effects of these agents, which may be favorable for treating cerebral aneurysms. This study was conducted to evaluate the degree of endovascular histologic change associated with ultrathin gold- or vitronectin-coated platinum coils.

Effects of nanoparticles on the adhesion and cell viability on astrocytes.

In recent years, both pharmaceutical companies and manufacturing industries have expressed heightened interest in the potential applications of magnetic nanoparticles for therapeutic and technological purposes. Specifically, pharmaceutical companies seek to employ magnetic nanoparticles as carriers to facilitate effective drug delivery, especially in areas of the brain. Manufacturing industries desire to use these nanoparticles as ferrofluids and in magnetic resonance imaging.

Blends of amphiphilic trisilanolisobutyl-POSS and phosphine oxide substituted poly(dimethylsiloxane) at the air/water interface.

Mixtures of a polyhedral oligomeric silsesquioxane, trisilanolisobutyl-POSS, and a polar silicone, poly(dimethyl-co-methylvinyl-co-methyl, 2-diphenyl phosphine oxide ethyl) siloxane (PDMS-PO), spread as Langmuir monolayers at the air/water interface are used to examine the surface phase behavior and aggregation of trisilanolisobutyl-POSS as a function of silicone composition. Analyses of the surface pressure-area per monomer (Pi-A) isotherms in terms of the collapse pressures and excess Gibbs free energies of mixing indicate the monolayers form slightly negative deviation mixtures. Direct observations of surface morphology with Brewster angle microscopy in the collapsed regime reveal that the governing factor for aggregation is the collapse Pi of the component with a stronger affinity for water.

Identifying possible contingencies during descriptive analyses of severe behavior disorders.

Contingencies of reinforcement involve, in part, relations between behavior and subsequent environmental events. In this study we observed 11 individuals with developmental disabilities and severe behavior problems while they interacted with their primary care providers in simulated environments (hospital therapy rooms). We compared the probability of obtaining attention, escape from instructional demands, or access to materials following instances of problem behavior with the background probability of those events.

Preference for unreliable reinforcement in children with mental retardation: the role of conditioned reinforcement.

We examined the effects of conditioned reinforcement on children's choice between reliable (100%) and unreliable (50%) reinforcement under various stimulus conditions in a concurrent-chains procedure. The study was conducted across three experiments. Experiments 1 and 2 were conducted under conditions similar to basic laboratory work and consisted of participants selecting from one of two black boxes (placed on a table) that were correlated with different reinforcement schedules.

Evaluating self-control and impulsivity in children with severe behavior disorders.

Impulsivity and self-control involve a choice between a smaller, more immediate reinforcer and a larger, more delayed reinforcer. Impulsive behavior occurs when responding produces the more immediate, relatively smaller reinforcers at the expense of delayed larger reinforcers. Self-control occurs when responding produces delayed larger reinforcers at the expense of immediate smaller reinforcers.

Competition between positive and negative reinforcement in the treatment of escape behavior.

We compared the effects of reinforcing compliance with either positive reinforcement (edible items) or negative reinforcement (a break) on 5 participants' escape-maintained problem behavior. Both procedures were assessed with or without extinction. Results showed that compliance was higher and problem behavior was lower for all participants when compliance produced an edible item rather than a break.

Response covariation. The relationship between correct academic responding and problem behavior.

This article examined the relationship between the accuracy of academic responding and aggression for two boys with mild mental retardation. Their teacher reported low rates of correct responding and high rates of aggressive behavior during spelling instruction. A functional analysis showed that aggression was escape maintained.

Increasing accuracy and decreasing latency during clean intermittent self-catheterization procedures with young children.

We examined the effects of simulation training on performance of clean intermittent self-catheterization procedures with 2 young girls. Simulation training was conducted, after which independent performance was assessed within a multiple baseline design. The training resulted in increased accuracy and decreased latency for both girls.

Fixed-time schedules attenuate extinction-induced phenomena in the treatment of severe aberrant behavior.

We compared the effects of extinction (EXT) and fixed-time (FT) schedules as treatment for severe problem behavior displayed by 3 individuals with developmental disabilities. First, functional analyses identified the reinforcers maintaining aberrant behavior for all 3 individuals. Next, EXT and FT schedules were compared using a multielement design.

Assessment of stimulus generalization gradients in the treatment of self-injurious behavior.

Descriptive and experimental analyses suggested that the self-injurious behavior (SIB) of a 10-year-old girl with severe mental retardation was maintained by attention. Additional analyses identified physical contact as the type of attention maintaining SIB; therefore, we hypothesized that physical proximity of an adult was a discriminative stimulus for SIB. Based on these findings, we systematically varied the distance between the participant and a therapist to assess stimulus generalization.

The effect of reinforcer preference on functional analysis outcomes.

We combined functional analyses and concurrent-schedule assessments to identify reinforcer preference during situations in which problem behavior may have been multiply controlled. Participants were 3 children with developmental delays who engaged in problem behavior during toy play with another child and one adult present, suggesting that problem behavior may have been maintained by adult attention or access to tangible reinforcement. Thus, conditions were designed to test attention and access-to-toys hypotheses.

Targeted ablation of the phospholamban gene is associated with a marked decrease in sensitivity in aortic smooth muscle.

Phospholamban (PLB) is a protein associated with the Ca(2+)-ATPase of the sarcoplasmic reticulum (SR) in cardiac, slow-twitch skeletal, and smooth muscle. PLB inhibits the SR Ca(2+)-ATPase in cardiac muscle; this inhibition is relieved on phosphorylation. The role of PLB in smooth muscle contractility is less clear.

Noncontingent reinforcement as treatment for severe problem behavior: some procedural variations.

Noncontingent reinforcement (NCR) as a treatment for problem behavior has typically included (a) continuous access to reinforcers at the onset of treatment and (b) extinction. We extended research on NCR by conducting a three-phase preliminary investigation of these components. In Phase 1, a functional analysis showed that the problem behavior of 3 participants with developmental disabilities was maintained by tangible positive reinforcement.

Functional analysis and treatment of eye poking with response blocking.

A functional analysis of eye poking by a 4-year-old female with severe disabilities and visual impairments showed that high rates occurred in all conditions. We conducted a series of probes to identify the maintaining variable for eye poking following an undifferentiated functional analysis. Results showed that eye poking decreased only when we interrupted finger-eye contact by blocking the response.

Treatment of multiply controlled problem behavior.

The aggressive behavior of a young boy with developmental delays occurred most frequently following a request to pick up his toys. The request ended a period of play and social interaction. This suggested the presence of multiple establishing operations.

The paradox of preference for unreliable reinforcement: The role of context and conditioned reinforcement.

We discuss Belke and Spetch's (1994) work on choice between reliable and unreliable reinforcement. The studies by Belke and Spetch extend a line of basic research demonstrating that under certain experimental conditions in a concurrent chains procedure, pigeons prefer an alternative that produces unreliable reinforcement. The authors describe the variables that influence preference for unreliable reinforcement, including the signaling and the duration of the reinforcement schedules, the context in which the signaling stimuli occur, and the effects of conditioned reinforcement.

Identification and modification of a response-class hierarchy.

We evaluated the effects of extinction and negative reinforcement on the latency of response-class members following requests made to a 15-year-old female with moderate mental retardation and autism. A functional analysis showed that the class members (screams, aggression, and self-injury) were escape maintained. Informal observations suggested that these topographies generally occurred in the sequence listed above and therefore may have been hierarchically related.

Reducing escape behavior and increasing task completion with functional communication training, extinction, and response chaining.

The effects of functional communication training, extinction, and response chaining on 3 subjects' escape-maintained aberrant behavior were evaluated using a multielement design. Functional communication training consisted of teaching subjects a verbal response that was functionally equivalent to their aberrant behavior. Subjects initially were allowed to escape from a task contingent on the trained verbal response.

Successful behavioral intervention to treat children who are reluctant to ambulate.

The authors report two patients with marginal ambulation skills whose severe behavioral problems prevented participation in physical therapy. The problem behavior also limited the patients' participation in activities of daily living and social interaction. Because of the risks of loss of ambulation to overall health, an aggressive behavioral intervention was implemented to decrease problem behavior and to increase participation in physical therapy.