Joint attention and early social communication: implications for research on intervention with autism

Highly structured, intensive early intervention may lead to significant developmental gains for many children with autism. However, a clear understanding of early intervention effects may currently be hampered by a lack of precision in outcome measurement. To improve the precision and sensitivity of outcome assessment it may be useful to integrate research on the nature of the social disturbance of autism with research on early intervention. In this regard, it may be that measures of nonverbal social communication skills are especially important in the study of preschool intervention programs. This is because these measures appear to tap into a cardinal component of the early social disturbance of autism, and because these measures have been directly related to neurological, cognitive, and affective processes that may play a role in autism. The research and theory that support the potential utility of these types of measures for early intervention research are reviewed. Examples are provided to illustrate how these types of measures may assist in addressing current issues and hypotheses about early intervention with autism including the "recovery hypothesis," the "pivotal skill hypothesis," and the relative effectiveness of discrete trial versus incidental learning approaches to early intervention. A cybernetic model of autism is also briefly described in an effort to better understand one potential component of early psychoeducational treatment effects with children with autism.     

Thermal Inertia Properties of Autoclaved Aerated Concrete

Autoclaved aerated concrete (AAC) is a lightweight, porous concrete with advanced thermal properties. AAC is unique among construction materials in combining excellent thermal resistance and thermal inertia. Generally, low-density construction materials do not provide good thermal inertia, while heavier ones commonly have poor thermal resistance. Five different 10.2 cm (4 in.) AAC samples made from U.S. electric utility fly ash as the silica source, along with three 10.2 cm (4 in.) conventional building material specimens, were tested for thermal inertia properties. Three primary issues addressed by these experiments were: (1) to develop and compare AAC thermal inertia to conventional building materials; (2) to document differences in thermal inertia characteristics of the AAC blocks produced by the various utilities; and (3) to determine if a periodic heat flow model using the thermal inertia approach adequately predicts the observed thermal inertia parameters of a material. A theoretical periodic heat flow model in the literature for thermal inertia did an adequate job of predicting the observed thermal inertia parameters for the AAC and conventional construction samples.     

Issues raised by facilitated communication for theorizing and research on autism

There is considerable disagreement in the literature and among clinicians about the success of facilitated communication, a new method of augmentative communication being used with people diagnosed autistic. Some claim almost everyone exposed to it achieves success, basing their claims upon their observations and experiences of naturally occurring facilitated interactions. Others claim minimal or no success, basing their claims on their observations of facilitated interactions under controlled experimental conditions. I argue here that both claims can be valid and that FC users with autism are sometimes competent and other times incompetent, depending upon the conditions under which they are evaluated. I support my argument by offering a collaborative view of communication in place of the commonly held view that communication involves passing messages over an invisible conduit. Given the assumption that facilitated communication does allow for the expression of unexpected competence for many with autism, I describe various unusual phenomena being revealed by facilitation and FC users and offer some theoretical approaches for explaining these phenomena. I then propose some research ideas for studying the phenomena associated with FC and offer them as suggestions for how we might proceed in our efforts to develop our understanding of when and how it works for people with autism.     

Transcriptional control of AAC3 gene encoding mitochondrial ADP/ATP translocator in Saccharomyces cerevisiae by oxygen, heme and ROX1 factor

The AAC3 gene of Saccharomyces cerevisiae encodes a mitochondrial ADP/ATP translocator which is subject to oxygen repression. Evidence is presented here, that the repression of AAC3 expression is dependent upon heme and the ROX1 factor. The promoter region of the AAC3 gene was isolated, sequenced, and deletion analysis was performed using lacZ as a reporter gene to determine the cis-acting regions responsible for the regulation of AAC3 expression. The results of the deletion analysis show that the negative control of the AAC3 gene by oxygen and ROX1 factor is mediated by an upstream repression sequence consisting of a T-rich segment adjacent to the consensus elements that are present in the 5' flanking regions of several other yeast genes. An additional upstream repressor site was located within the AAC3 promoter which, however, is not related either to oxygen or to ROX1 factor. The data presented here delineate the main cellular factors and DNA sequences involved in the regulatory mechanism by which an essential function for anaerobic cells growth, ADP/ATP translocation, is ensured. In addition, they show that the AAC3 gene belongs to the family of yeast genes including TIF51B, COX5b, HEM13 and CYC7 that are negatively regulated by oxygen and heme.     

Cloning and DNA sequence analysis of an aac(3)-Vb gene from Serratia marcescens

The AAC(3)-V resistance mechanism is characterized by high-level resistance to the aminoglycosides gentamicin, netilmicin, 2'-N-ethylnetilmicin, and 6'-N-ethylnetilmicin and moderate resistance levels to tobramycin. Serratia marcescens 82041944 contains an AA(3)-V resistance mechanism as determined from aminoglycoside resistance profiles. This strain, however, does not exhibit hybridization with a probe derived from the previously cloned aac(3)-Va gene, (R. Allmansberger, B. Br?u, and W. Piepersberg, Mol. Gen. Genet. 198:514-520, 1985). High-pressure liquid chromatography analysis of the acetylation products of sisomicin carried out by extracts of S. marcescens 82041944 have demonstrated the presence of an AAC(3) enzyme. We have cloned the gene encoding this acetyltransferase and have designated it aac(3)-Vb. Nucleotide sequence comparisons show that the aac(3)-Va and aac(3)-Vb genes are 72% identical. The predicted AAC(3)-Vb protein is 28,782 Da. Comparisons of the deduced amino acid sequences show 75% identity and 84% similarity between the AAC(3)-Va and AAC(3)-Vb proteins. The use of a DNA fragment internal to the aac(3)-Vb as a hybridization probe demonstrated that the aac(3)-Vb gene is very rare in clinical isolates possessing an AAC(3)-V mechanism.     

Lateral Out-of-Plane Strengthening of Masonry Walls with Composite Materials

The structural behavior of masonry walls laterally strengthened with externally bonded composite materials to resist out-of-plane loads is theoretically and experimentally studied. Hollow concrete block masonry walls and solid autoclaved aerated concrete (AAC) block masonry walls are examined. A theoretical model that accounts for the cracking and the physical nonlinear behavior, the debonding of the composite layers, the arching effect, the interfacial stresses, and the unique modeling aspects of the laterally strengthened wall is presented. The experimental study includes loading to failure of 4 laterally strengthened masonry walls and 2 control walls. The experimental and analytical results point at the unique aspects of the lateral strengthening of masonry walls with composite materials. In particular, they reveal and explain the premature shear failure in laterally strengthened hollow concrete blocks walls and, on the other hand, demonstrate the potential of lateral fiber-reinforced polymer strengthening of AAC masonry walls. The laterally strengthened AAC masonry walls reveal improved strength, deformability, and integrity at failure characteristics.     

The role of TGFbeta1 in initiating hepatic stellate cell activation in vivo

This article provided an introduction to AAC systems for children and adolescents with severe spoken-language disorders. Over the last decade, significant advances have been made in assessment and intervention approaches. For children with severe spoken communication disabilities, the AAC assessment is an ongoing process that includes information about the child's communication development, the child's environments, and the child's physical abilities. Children with severe disabilities who use AAC systems can demonstrate communication achievements far beyond traditional expectations. Recommended assessment and intervention practices are continuing to develop and the future is certainly optimistic for children with severe spoken-language disorders who may use AAC to communicate.     

Acute non-calculous cholecystitis at a multidisciplinary intensive care unit

OBJECTIVE: To describe three cases of acute acalculous cholecystitis (AAC) in critically ill patients. PATIENTS AND METHODS: Admission charts of critically ill patients who required advanced life support in the intensive care unit and fulfilled three or more of the following ultrasonographic or tomographic diagnostic criteria for AAC were reviewed: 1. Gallbladder wall thickness > 4 mm with an increase in its volume (vesicular hydrops), 2. Pericholecystic fluid, 3. Subserosal edema, 4. Sloughing of the mucosa, 5. Abscence of calculi. RESULTS: Three men that met the criteria for AAC were identified from a total of 490 admission charts. The median age was 49 years, the average APACHE II at admission was 17 points. The median time in the ICU before development of AAC was 24 days. All patients had leukocytosis. The three cases were resolved by percutaneous cholecystostomy and external biliary drainage. CONCLUSIONS: The incidence of AAC in our ICU is one s case per 160 admissions or 0.6%. Shock, use of vasopressor drugs, narcotics and mechanical ventilation with PEEP are frequent in patients who subsequently develop AAC. Percutaneous cholecystostomy with external biliary drainage constitutes a safe and definitive treatment when there is no gangrene of the gallbladder wall.     

The picture exchange communication system

The Picture Exchange Communication System (PECS) was developed as a means to teach children with autism and related developmental disabilities a rapidly acquired, self-initiating, functional communication system. Its theoretical roots combine principles from applied behavior analysis and guidelines established within the field of alternative and augmentative communication. This approach has several potential advantages relative to imitation-based strategies (both vocal and gestural) and symbol selection strategies. The system begins with the exchange of simple icons but rapidly builds "sentence" structure. The system also emphasizes developing the request function prior to developing responding to simple questions and commenting. The development of requesting with a sentence structure also permits the rapid development of attributes more traditionally taught within a receptive mode. The relationship between the introduction of PECS and various other behavioral issues (i.e., social approach and behavior management) as well as its relationship to the codevelopment of speech are reviewed.     

Relationship between goal attributes and the academic achievement of Southeast Asian adolescent refugees.

Examined the relationship among goals, acculturation (ACC), and academic achievement (AAC) for a group of 39 Southeast Asian adolescent refugees enrolled in a bilingual vocational education program at a high school. Students expressed career, work, and family goals that were positive in affect and individual in nature. Low goal instability and high goal commitment were significantly related to higher GPA and goal attainment. Low goal instability was also related to better study skills. ACC was not significantly related to AAC variables. Although the relationship between goal attributes and AAC was supported for these Ss, cultural factors limited the authors' ability to interpret the results. A discussion of cross-cultural issues that are relevant for future research with Southeast Asian refugees is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resistance to amikacin and isepamicin in rabbits with experimental endocarditis of an aac(6')-Ib-bearing strain of Klebsiella pneumoniae susceptible in vitro

The effect of production of the aminoglycoside 6'-N-acetyltransferase [AAC(6')-IB] in Klebsiella pneumoniae on the outcome of amikacin and isepamicin treatment of rabbits with experimental endocarditis was assessed. Isogenic high-level (Hi) and low-level (Lo) AAC(6')-Ib-producing transconjugants (T) were constructed from clinical isolates with plasmid-borne resistance determinants. The MICs of amikacin and isepamicin, their bactericidal effects, and AAC(6')-Ib production appeared to be well correlated among the clinical isolates and the transconjugants. The susceptibility data determined in vitro, with MICs (in micrograms per milliliter) of amikacin and isepamicin for LoT and HiT of 4 and 0.5 and 32 and 8, respectively, were, however, not predictive of the in vivo efficacies of the drugs. While amikacin and isepamicin caused reductions in bacterial densities (log10 CFU per gram of cardiac vegetation) of 5.1 and 4.8 of the fully susceptible recipient strain (MICs of amikacin and isepamicin, 0.5 and 0.25, respectively), the reductions in density of both LoT and HiT caused by the two drugs (2.7 and 2.4 and 2.9 and 2.2, respectively) were only marginally significant, if at all. There was no significant difference (P > 0.05) when the reductions in density of LoT and HiT by either drug were compared or when the efficacies of the two drugs in reducing the density of any strain [non-AAC(6')-producing, LoT, or HiT] were compared (P > 0.5). It is concluded that AAC(6')-Ib in K.pneumoniae, even when produced at a low level and not conferring resistance to amikacin and isepamicin in vitro, compromises the efficacies of both drugs in vivo and possibly does so beyond the experimental model studied here.     

Increasing communicative interactions of young children with autism using a voice output communication aid and naturalistic teaching

We evaluated the effects of a voice output communication aid (VOCA) and naturalistic teaching procedures on the communicative interactions of young children with autism. A teacher and three assistants were taught to use naturalistic teaching strategies to provide opportunities for VOCA use in the context of regularly occurring classroom routines. Naturalistic teaching procedures and VOCA use were introduced in multiple probe fashion across 4 children and two classroom routines (snack and play). As the procedures were implemented, all children showed increases in communicative interactions using VOCAs. Also, there was no apparent reductive effect of VOCA use within the naturalistic teaching paradigm on other communicative behaviors. Teachers' ratings of children's VOCA communication, as well as ratings of a person unfamiliar with the children, supported the contextual appropriateness of the VOCA. Probes likewise indicated that the children used the VOCAs for a variety of different messages including requests, yes and no responses, statements, and social comments. Results are discussed in regard to the potential benefits of a VOCA when combined with naturalistic teaching procedures. Future research needs are also discussed, focusing on more precise identification of the attributes of VOCA use for children with autism, as well as for their support personnel.     

Catheter-directed thrombolysis in the treatment of phlegmasia cerulea dolens

The objective of this study was to review the incidence, risk factors, methods of diagnosis, and outcome of acute acalculous cholecystitis (AAC) and to identify the sensitivity and limitations of current radiographic modalities used to establish the diagnosis. Our study was a retrospective chart review in a tertiary-care university hospital. Over a 53-month period, 27 cases of AAC (17 males, 10 females; mean age 50 years; mean Acute Physiology and Chronic Health Evaluation II score, 17) were encountered. Of these, 14 (52%) occurred in critically ill patients and 17 (63%) in patients recovering from non-biliary tract operations. AAC occurred in 0.19 per cent of surgical intensive care unit admissions and accounted for 14 per cent (27 of 188) of all cases of acute cholecystitis. Presenting symptoms and laboratory values were nonspecific. Twenty patients had radiographic studies before surgery. Among the various radiological studies used for AAC, morphine cholescintigraphy had the highest sensitivity (9 of 10; 90%), followed by computed tomography (8 of 12; 67%) and ultrasonography (2 of 7; 29%). Ten of the 20 patients had more than one study done preoperatively. All 27 patients had an open cholecystectomy. AAC was associated with a high incidence of gangrene (17 of 27 cases; 63%), perforation (4 of 27; 15%), and abscess (1 of 27; 4%). The mortality rate was 41 per cent (11 of 27). We conclude that AAC is a rare, but potentially lethal, disease occurring in critically ill patients and those recovering from non-biliary tract operations. The clinical presentation is nonspecific, and significant delays in diagnosis result in a high incidence of gangrene, perforation, abscess, and death. To improve outcome, a high index of suspicion with early radiographic evaluation, often employing multiple studies, is necessary. An algorithm for the evaluation of patients for suspected AAC is proposed.     

The import route of ADP/ATP carrier into mitochondria separates from the general import pathway of cleavable preproteins at the trans side of the outer membrane

The ADP/ATP carrier (AAC) of the mitochondrial inner membrane is synthesized in the cytosol without a cleavable presequence. The preprotein preferentially binds to the mitochondrial surface receptor Tom70 and joins the import pathway of presequence-carrying preproteins at the cis side of the outer membrane. Little is known about the translocation of the AAC across the outer membrane and where its import route separates from that of cleavable preproteins. Here we have characterized a translocation intermediate of AAC during transfer across the outer membrane. The major portion of the preprotein is exposed to the intermembrane space, while a short segment is still accessible to externally added protease. This intermediate can be quantitatively chased to the fully imported form in the inner membrane. Its accumulation depends on Tom7, but not on the intermembrane space domain of Tom22 in contrast to cleavable preproteins. Moreover, opening of the intermembrane space inhibits the import of AAC, but not that of cleavable preproteins into mitoplasts. We conclude that the import route of AAC diverges from the general import pathway of cleavable preproteins already at the trans side of the outer membrane.     

Latent-class analysis of recurrence risks for complex phenotypes with selection and measurement error: a twin and family history study of autism

The use of the family history method to examine the pattern of recurrence risks for complex disorders such as autism is not straightforward. Problems such as uncertain phenotypic definition, unreliable measurement with increased error rates for more distant relatives, and selection due to reduced fertility all complicate the estimation of risk ratios. Using data from a recent family history study of autism, and a similar study of twins, this paper shows how a latent-class approach can be used to tackle these problems. New findings are presented supporting a multiple-locus model of inheritance, with three loci giving the best fit.     

Biochemical and genetic mechanisms for bacteria to acquire aminoglycoside antibiotic resistance

Aminoglycoside (AG)-modifying enzymes are the major biochemical basis for the AG resistance of clinically-occurring bacteria. Recent AG resistance profiles can be characterized by the involvement of AAC(6') in combination with other modifying enzymes in Gram negative bacteria. AAC(6')/APH(2") in Staphylococcus aureus is also remarkable. Genetic basis for the emergence or alteration of AG resistance profiles includes point mutations in the regulatory region or specific sites of the coding region of AG-modifying enzyme genes, and rearrangement of the genes caused by transposon and/or integron. In addition, semisynthetic AG antibiotics such as amikacin, arbekacin (ABK) and isepamicin were also reviewed for their stability to AG-modifying enzymes. ABK that has been widely used as an anti-MRSA drug in Japan is distinct from the other AGs because its monoacetylated derivatives (3"-N-acetylABK and 2'-N-acetylABK) by AG acetyltransferases, AAC(3) and AAC(2'), respectively, retain clear antibiotic activities. Based on this novel aspect and the lack of modification sites for APH(3') and ANT(4'), ABK should be regarded as the most refractory AG for bacteria to acquire resistance.     

Mutagenesis of some positive and negative residues occurring in repeat triad residues in the ADP/ATP carrier from yeast

In AAC2 from Saccharomyces cerevisiae, nine additional charged residues (six positive, three negative) were neutralized by mutagenesis following the previous mutation of six arginines. Oxidative phosphorylation (OxPhos) in cells and mitochondria, the expression level of AAC protein, and the various transport modes of AAC in the reconstituted system were measured. Mutations are: within the first helix at K38A which is exclusive for AAC; K48A, and R152A, part of a positive triad occurring in the matrix portion of each repeat; two matrix lysines, K179M and K182I, and the negative triad helix-terminating residues, E45G, D149S, D249S. Cellular ATP synthesis (OxPhos) is nearly completely inhibited in K48A, R152A, D149S, and D249S, but still amounts to 10% in K38A and between 30% and 90% in the gly+ mutants K179M, K179I + K182I, and E45G. Comparison of the AAC content measured by ELISA and the binding of [3H]CAT and [3H]BKA reveals discrepancies in K48A, D149S, and D249S mitochondria, which provide evidence that these mutations largely abolish inhibitor binding. Also these mitochondria have undetectable OxPhos. Differently in K38A, CAT and BKA binding are retained at high AAC levels but OxPhos is very low. This reveals a special functional role of K38, different from the more structural role of R152, K48, D149, and D249. Transport activity was measured with reconstituted AAC. The electroneutral ADP/ADP exchange of gly- mutants is largely or fully suppressed in K48A, D149S, and D249S. K38A and R152A are still active at 18% and 30% of wt. The other three exchange modes, ATP/ADP, ADP/ATP, and ATP/ATP, are nearly suppressed in all gly- mutants but remain high in gly+ mutants. ATP-linked modes are higher than the ADP/ADP mode in gly+ but lower in gly- mutants, resulting in an exchange mode inversion (EMI). In the competition for AAC2 transport capacity, the weak ATP exporting modes are suppressed by the much stronger unproductive ADP/ADP mode causing inhibition of OxPhos. Together with previous results all members of three charge triads are now mutagenized, revealing drastic functional rotatory asymmetries within the three repeat domains. In the intrahelical arginine triad the third (R294A), in the positive matrix triad the second (R152A), and in the helix-terminating negative triad the first (E45G) still show high activity.     

Mechanisms of developmental regression in autism and the broader phenotype: A neural network modeling approach.

Loss of previously established behaviors in early childhood constitutes a markedly atypical developmental trajectory. It is found almost uniquely in autism and its cause is currently unknown (Baird et al., 2008). We present an artificial neural network model of developmental regression, exploring the hypothesis that regression is caused by overaggressive synaptic pruning and identifying the mechanisms involved. We used a novel population-modeling technique to investigate developmental deficits, in which both neurocomputational parameters and the learning environment were varied across a large number of simulated individuals. Regression was generated by the atypical setting of a single pruning-related parameter. We observed a probabilistic relationship between the atypical pruning parameter and the presence of regression, as well as variability in the onset, severity, behavioral specificity, and recovery from regression. Other neurocomputational parameters that varied across the population modulated the risk that an individual would show regression. We considered a further hypothesis that behavioral regression may index an underlying anomaly characterizing the broader autism phenotype. If this is the case, we show how the model also accounts for several additional findings: shared gene variants between autism and language impairment (Vernes et al., 2008); larger brain size in autism but only in early development (Redcay & Courchesne, 2005); and the possibility of quasi-autism, caused by extreme environmental deprivation (Rutter et al., 1999). We make a novel prediction that the earliest developmental symptoms in the emergence of autism should be sensory and motor rather than social and review empirical data offering preliminary support for this prediction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Play and the child with autism spectrum disorder: From possibilities to practice.

In this article, the author (a) examines the nature of play as it pertains to children with autism spectrum disorder and (b) analyzes the theories surrounding play deficit explanations in this population of children. Possibilities for practice are discussed in terms of behavioral and developmental approaches to play. An argument is made in favor of developmental play therapy for children who have autism spectrum disorder. Support for developmental approaches is shaped by a definition of play that embraces a child-directed model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Static and Cyclic Racking Performance of Autoclaved Aerated Concrete Cladding Panels

Laboratory experiments subjected full-scale autoclaved aerated concrete (AAC) cladding panel specimens to static monotonic loading and incrementally increased displacement amplitudes of cyclic racking movements. The objective of the study was to characterize the seismic performance of cladding panel walls made up of the newly introduced AAC in the U.S. market. The study found that conventional connectors used to attach AAC cladding panels to structural systems have not been designed for in-plane seismic resistance and would need to be redesigned in order to safely satisfy building code’s allowable drift.