Alternative Reinforcement Research Articles

Viral-Mediated Knockdown of Nucleus Accumbens Shell PAC1 Receptor Promotes Excessive Alcohol Drinking in Alcohol-Preferring Rats.

Alcohol use disorder (AUD) is a chronic, relapsing disorder whose genetic and environmental susceptibility components are not fully understood. Neuropeptidergic signaling has been repeatedly implicated in modulating excessive alcohol drinking, especially within sub-regions of the striatum. Here, we investigated the potential involvement of the selective receptor for pituitary adenylate cyclase-activating polypeptide (PACAP), PAC1R, in the nucleus accumbens shell (NAcc Shell) in excessive alcohol drinking in alcohol-preferring rats, an established animal model of the genetic propensity for alcoholism. Scr:sP alcohol-preferring rats were trained to operantly self-administer alcohol and then either an AAV virus short-hairpin RNA (shRNA) targeted to knockdown PAC1R, or an AAV control virus were microinfused into the NAcc Shell. NAcc Shell PAC1R shRNA knockdown virus was confirmed to significantly decrease PAC1R levels in the NAcc Shell. The effects of NAcc Shell PAC1R shRNA knockdown on ethanol self-administration were investigated using a Fixed Ratio (FR) 1 and a Progressive Ratio (PR) schedule of reinforcement. The effect of PAC1R knockdown on self-administration of an alternative reinforcer, saccharin, was also assessed. The results showed that the reduction in PAC1R in the NAcc Shell led to excessive ethanol drinking, increased preference for ethanol, and higher motivation to drink. NAcc Shell PAC1R shRNA knockdown did not comparably increase saccharin self-administration, suggesting selectivity of action. These data suggest that NAcc Shell PAC1R may serves as a “brake” on alcohol drinking, and thereby the loss of function of PAC1R leads to excessive alcohol consumption. Therefore, the PACAP/PAC1R system may represent a novel target for the treatment of AUD.

Reinforcer pathology's alternative reinforcer hypothesis: A preliminary examination.

The novel theory of Reinforcer Pathology states that the temporal window of integration, measured by delay discounting (DD), determines the value of reinforcers. Based on the Reinforcer Pathology theory, the valuation of alternative reinforcers is positively associated with the length of the temporal window (negatively with rates of discounting). The objective of this article is to test the Reinforcer Pathology theory by reanalyzing data from a prior report (Carr & Epstein, 2018) in order to examine the association between the reinforcing value of alternative reinforcement and the length of the measured temporal window. Participants (N = 250) who completed an adjusting delay discounting task and the Pleasant Events Schedule (PES) were included in the study. PES provides a measurement of a reinforcement score (a cross-product of PES measures of frequency and pleasantness) for 45 noneating alternative activities. Analysis of Variance and Spearman product-moment correlations were completed. Delay discounting was significantly positively correlated with sedentary reinforcement and significantly negatively correlated with cognitively enriching activities. A significant interaction was observed in the preference for between food and cognitive-enriching context as a function ln(k) in predicting the cognitive-enriching activity class. Nonsignificant relationships were also observed with the correlation of delay discounting to the reinforcement of social and physical activities. These findings provide initial support for Reinforcer Pathology theory and indicate that the temporal window over which reinforcers are integrated may be a factor contributing to a preference for some healthy or unhealthy alternative reinforcers. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

An investigation of the reinforcing value of video game playing relative to concurrently available monetary alternatives.

Video game playing (VGP) has received recent attention as a result of sharing many similarities with other addictive behaviors. Behavioral economic models are commonly used to understand drug use and other addictive behaviors and may similarly inform conceptual models of VGP. The present study employed behavioral economic principles to conceptualize relative reinforcing value for playing video games compared to concurrently available alternative potential monetary reinforcers. Participants (N = 81) played three video games picked to represent games of low, medium, and high quality (i.e., OutDrive, Forza Motorsport 1, and Forza Motorsport 7), with quality designations based on the research teams' assessment of various features of the game (e.g., graphics, sound, immersion) as well as the game's market value at the time the study was conducted. Participants played each game for 10 min and completed Visual Analog Scales and a multiple-choice procedure (MCP) designed to assess relative reinforcing value at various time points during and after each session. As hypothesized, both subjective ratings and relative reinforcing value increased as the designated quality of the game increased. More specifically, the high-quality game was rated as more fun and likable and had a higher MCP crossover point than the medium and low-quality games. Like other behavioral addiction studies, results suggest that methodologies and behavioral measures commonly used in drug administration literature can be effectively applied to VGP. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Performance of Polypropylene Fibre Reinforced Laterite Masonry Bricks

Accessibility to energy-efficient, cost-effective, and environmentally friendly materials are among the critical challenges that the building industry faces. In addition to its high cost, concrete and cement blocks or structures production is one of the factors that cause climate change. Therefore, the building industry has to develop innovative materials that contribute to the reduction of the challenges above. Due to its availability worldwide and its environmentally friendly characteristics, earth materials appear suitable against climate change in the building industry. However, blocks produced from earth materials have low compressive and tensile strengths and low durability. Recently, many researchers focused on stabilising soil with cement, lime, fibres, Etc. Cement/lime stabilisation is neither cost-effective nor energy-efficient, while natural fibres reinforcement faces durability challenges. In this study, a laterite soil was reinforced with polypropylene fibre, a type of waste plastic. The use of these plastic wastes contributes to reducing plastic worldwide and producing low-cost and environmentally friendly building materials. The main objective of this research work is to study the performance of polypropylene reinforced laterite bricks. A hair-like polypropylene fibre was mixed with air-dried laterite soil at 0, 0.05, 0.1, 0.15, 0.20, 0.25, 0.30, and 0.4% fibre content by weight of dry soil. The blocks and bricks made were air-dried for 14 days and tested according to EN 772-1:2011 (E). The findings on the unconfined compressive strength test, indirect splitting tensile test, compression test and initial rate of water absorption test are presented in this paper. The results indicate that the compressive strength of reinforced bricks increased by 84%, and the water absorption rate was reduced by 50% at 0.23% fibre content by weight of dry soil. These results show that polypropylene fibre can be an alternative reinforcement material to produce more durable earth blocks and bricks with improved compressive strength. It is recommended that one should mix dry laterite soil with fibre. Then add the optimum water content determined from the compaction test and mix until the mixture is homogenous before making blocks/bricks. Blocks/bricks made should be air-dried, avoiding exposition to sunlight.

Effect of Different Lateral Reinforcement and its Spacing on Column Reinforced with Hollow Composite Sections

Abstract: Hollow Concrete Columns (HCCs) are one of the preferred construction systems in civil infrastructures including bridge piers, ground piles, and utility poles to minimize the overall weight and costs. HCCs are also considered a solution to increase the strength to mass ratio of structures. However, HCCs are subjected to brittle failure behaviour by concrete crushing means that the displacement capacity and the strength after steel yielding in HCCs are decreasing due to the unconfined concrete core. Absence of the concrete core changes the inner stress formation in HCCs from triaxial to biaxial causes lower strength. A new type of Hollow Composite Reinforcing System (HCRS) has recently been designed and developed to create voids in structural members. This reinforcing system has four external flanges to facilitate mechanical bonding and interaction with concrete. Therefore, providing the inner Hollow Composite Reinforced Sections (HCRS) can significantly increase strength by providing a higher reinforcement ratio and confining the inner concrete core triaxially. The corrosion of steel is also a notable factor in the case of steel reinforced HCCs which became more critical because their outer and inner surfaces exposing more concrete surface area. An alternative reinforcement is Glass Fibre Reinforced Polymer (GFRP) bars, can overcome the brittle behaviour of steel reinforced HCC. In previous studies, HCC shows high strength capacity, when appropriate reinforcement in the form of longitudinal GFRP bars, laterally using GFRP spirals and internally using rectangular HCRS which provide enough inner confinement. However, the spirals laterally restrict the expansion of the concrete core and limit the buckling of the longitudinal bars, allowing the columns to keep resisting applied loads and gives maximum strength. Therefore, in this study, the spirals are replaced by discrete hoops as lateral reinforcement to analyse the effect on structural behaviour of HCC reinforced with rectangle shaped HCRS under axial load using ANSYS software. The results show that column laterally reinforced with spiral attained insignificant increase in strength than their counterpart specimens confined with hoops. So, the circular hoops were found to be as efficient in confining concrete as spirals in a column reinforced internally with rectangle shaped HCRS. The increase in volumetric ratio can be achieved by reducing the spacing between lateral reinforcement. So, this study also investigates the effectiveness of reducing the spiral spacing in HCC reinforced with HCRS, three models with lateral spacing of 50mm, 40mm and 30mm are modelled and analysed. The results show that columns with closer spiral spacing attained more axial stability. Keywords: Hollow Concrete Column, Rectangular Hollow Composite Reinforced Sections, GFRP Spirals, GFRP Hoops, Nonlinear Static Analysis, ANSYS.

Extraction and Characterization of Natural Cellulosic Fiber from Pandanus amaryllifolius Leaves.

Pandanus amaryllifolius is a member of Pandanaceae family and is abundant in south-east Asian countries including Malaysia, Thailand, Indonesia and India. In this study, Pandanus amaryllifolius fibres were extracted via a water retting extraction process and were investigated as potential fibre reinforcement in polymer composite. Several tests were carried out to investigate the characterization of Pandanus amaryllifolius fibre such as chemical composition analysis which revealed Pandanus amaryllifolius fibre’s cellulose, hemicellulose and lignin content of 48.79%, 19.95% and 18.64% respectively. Material functional groups were analysed by using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis confirming the presence of cellulose and amorphous substances in the fibre. The morphology of extracted Pandanus amaryllifolius fibre was studied using a scanning electron microscope (SEM). Further mechanical behaviour of fibre was investigated using a single fibre test with 5 kN cell load and tensile strength was found to be 45.61 ± 16.09 MPa for an average fibre diameter of 368.57 ± 50.47 μm. Meanwhile, moisture content analysis indicated a 6.00% moisture absorption rate of Pandanus amaryllifolius fibre. The thermogravimetric analysis justified the thermal stability of Pandanus amaryllifolius fibre up to 210 °C, which is within polymerization process temperature conditions. Overall, the finding shows that Pandanus amaryllifolius fibre may be used as alternative reinforcement particularly for a bio-based polymer matrix.

Is addiction a brain disease? A plea for agnosticism and heterogeneity.

Although increasingly subject to criticism, the brain disease model of addiction (BDMA) remains dominant within addiction science. Yet few advocates or critics of the BDMA have provided an account of what a brain disease is. The aim of this review is to conceptually clarify what it would mean for the BDMA to be true, rather than to argue decisively for or against it. Conceptual clarification of the BDMA requires consideration of possible models of disease and their relationship to the BDMA. A barrier to such consideration is belief that the BDMA is necessary to combatting addiction stigma. To address this barrier, I begin with discussion of what we know about the effects of the brain disease label on addiction stigma, and why labelling effects should have no bearing on the validity of the BDMA. I then distinguish strong, minimal, network, and mismatch models of disease, and I argue that the BDMA aligns with a strong disease model. This means that underlying brain pathology is hypothesized to be the cause of the personal-level observable signs and experienced symptoms characteristic of addiction. Evaluation of the BDMA therefore requires analysis of the concepts of brain dysfunction and causation, and their application to addiction science. Brain dysfunction cannot be analyzed merely as brain changes or brain differences; nor can it be inferred merely from the presence of personal-level signs and symptoms. It is necessary to have an account of normal brain function by which to measure it. The theoretical and empirical challenges to developing such an account are not insurmountable, but they are substantial. Although there exist competing analyses of causation, there is a relatively standard method used to establish it within experimental science: intervention. Using this method, the causal significance of brain states, such as, e.g., extensive gray matter loss and/or neuroadapations in the mesocorticolimbic dopamine system, is not yet fully demonstrated. Further studies are necessary to determine their effect compared with other possible variables, such as, e.g., alternative reinforcers. Conceptual clarification and preliminary empirical assessment of the BDMA recommends agnosticism about its validity and an openness to heterogeneity; in some cases addiction may be a brain disease, in others not. Either way, addiction stigma can be combatted by fighting moralism about drugs and moralistic drug policies directly, as opposed to resting hopes on the brain disease label.

Analysis of Concrete Column Reinforced Internally with Hollow Composite Sections

Abstract: Hollow Concrete Columns (HCCs) are one of the preferred construction systems in civil infrastructures including bridge piers, ground piles, and utility poles to minimize the overall weight and costs. HCCs are also considered a solution to increase the strength to mass ratio of structures. However, HCCs are subjected to brittle failure behaviour by concrete crushing means that the displacement capacity and the strength after steel yielding in HCCs are decreasing due to the unconfined concrete core. Absence of the concrete core changes the inner stress formation in HCCs from triaxial to biaxial causes lower strength. A new type of Hollow Composite Reinforcing System (HCRS) has recently been designed and developed to create voids in structural members. This reinforcing system has four external flanges to facilitate mechanical bonding and interaction with concrete. Therefore, providing the inner Hollow Composite Reinforced Sections (HCRS) can significantly increase strength by providing a higher reinforcement ratio and confining the inner concrete core triaxially. The corrosion of steel is also a notable factor in the case of steel reinforced HCCs which became more critical because their outer and inner surfaces exposing more concrete surface area. An alternative reinforcement is Glass Fibre Reinforced Polymer (GFRP) bars, can overcome the brittle behaviour of steel reinforced HCC. In previous studies, HCC shows high strength capacity, when appropriate reinforcement in the form of longitudinal GFRP bars, laterally using GFRP spirals and internally using newly developed HCRS which provide enough inner confinement. Therefore, this study aims to determine the effect of HCRS of different cross sections and also the effect of change in position of its flanges on the axial performance of HCC analytically using ANSYS software. Keywords: Hollow Concrete Column, Hollow Composite Reinforced Sections, GFRP bars, GFRP Spirals, Nonlinear Static Analysis, ANSYS.

Recycling of Residual Polymers Reinforced with Natural Fibers as a Sustainable Alternative: A Review.

The latest advances in green alternatives are being addressed with bio-based solutions, with uses and applications in new areas due to their wide potential, low cost, lightness, renewability, biodegradability, impact toughness, fatigue resistance, and other specific properties. Natural fibers are sustainable materials that have led researchers to test their viability as alternative reinforcements in residual polymers to meet required engineering specifications; therefore, it is essential to continue making progress in replacing conventional materials. This review is expected to provide an overview of the current scopes and future prospects of biocomposites from polymers reinforced with natural fibers with a focus on the following: i. recycling of residual polymers; ii. available natural fibers and their components in the context of engineering applications; iii. the behavior of the structural modifications of the natural fibers with the physical and chemical treatments in the matrix interaction as reinforcements of the residual polymers; and iv. applications for the development of innovative, efficient, and sustainable solutions for successful, environmentally responsible products.

The impact of social variables in preclinical models of cocaine abuse.

At present, there are no US Food and Drug Administration–approved treatments for cocaine use disorders. One consideration for this lack of treatment efficacy stems from the appropriate use of animal models. The premise of this commentary is that social behavior needs to be incorporated in animal models of cocaine use disorder. The goal of this commentary is to describe some of the strengths and limitations of recent preclinical animal models of cocaine abuse which have incorporated social behavior. There are many ways to include social variables into preclinical research, and the study design will depend on the questions asked. Four general types of studies incorporating social factors are described: those involving aggression (that is, maternal neglect and social defeat), modeling, social reward, and social housing, including social isolation. The inclusion of social variables into preclinical research will help identify biobehavioral markers that may lead to an individualized treatment approach that more effectively decreases cocaine use. These studies will aid in the development of novel pharmacotherapies as well as non-pharmacological interventions (for example, punishment, alternative reinforcers, and environmental enrichment) that would be critical for informing policy decisions.

A study on microstructure and mechanical behaviour of AA6063 metal matrix composite reinforced with areca sheath ash (ASA) and rice husk ash (RHA)

Now a day’s composite materials can also prepared with the addition of agricultural by products ash as a reinforcement which gives an effective result. The Rice Husk Ash (RHA) and Areca Sheath Ash (ASA) ranged from 0% to 8 % increased by 2% with the molten aluminium alloy individually using stir cast route hence evaluate performance of reinforcement. Microstructural characterization and mechanical properties have been used to evaluate the performance of the composites. SEM and EDS analyses were analysed for microstructure characterizations of composites. In this paper Hardness, Tensile strength, Compression strength properties were investigated. Results obtained from experiments that the hardness, compression strength and tensile strength of the composites increased with an increase in the weight percentage of Rice husk ash (RHA) and Areca sheath ash (ASA).From the results Areca sheath ash can also used as a alternative reinforcement which leads to increase properties of composites.

Effect of Surface Treatment on the Mechanical Performance of Unidirectional Enset Fiber Reinforced Polypropylene Composite

ABSTRACT Natural fibers have recently become an alternative reinforcement for composite products owing to their light-weightiness, renewability and biodegradability. However, they have certain drawbacks including hygroscopic nature, low compatibility with the polymer matrices and inferior mechanical properties when compared to synthetic fibers. This study aims to develop a one-way enset fiber-reinforced polypropylene (PP) composite. In this study, long and aligned enset fibers were interlaced with PP yarns to form a woven mat. The mat was surface treated, and later the film stacking method was applied to develop the composite via hot pressing. The mechanical properties of the developed composites were characterized. The results showed that bis[3-(triethoxysilyl) propyl] tetrasulfide (1.5 wt% Si69) and 3glycidyloxy propyl trimethoxy silane (5 wt%GPs) treated unidirectional enset fiber woven mat showed the highest tensile strength which shows an increase of 266.98% and 218.14%, respectively, relative to the pure PP. In terms of flexural strength, enset fibers treated with NaOH (3.5 wt%) and EVsi69 (1.5 wt%) showed the greatest improvement of 218.14% and 151.64% respectively over pure PP. Therefore, the developed composite samples confirmed that enset fiber can be effectively reinforced with PP for the application of automotive and construction industries.

Bonding Strength of Bamboo Reinforcement in Concrete – A Systematic Literature Review (SLR)

Towards sustainable environmental goals, the utilization of agricultural waste as concrete material in the low-cost construction industry has received special interest from many researchers. It is the best approach in converting waste into valuable sustainable products which consequently reduces abundant of the waste and avoid environmental pollution. Literature proved that bamboo has high tensile strength and the mechanical properties of bamboo are almost similar to steel reinforcement, besides the advantage of its lightweight and cost-effective. In this study, a Systematic Literature Review (SLR) is conducted to review the behaviour of the bonding strength of bamboo reinforcement in concrete. The SLR is proposed based on the widely adopted review protocol named ‘Reporting standards for Systematic Evidence Syntheses’ (ROSES). The proposed SLR procedure is critically discussed, starting from the formulation of the research question until the process of data abstraction and analysis. Particular emphasis is given on the different types of behaviour of bonding strength developed in bamboo reinforced concrete based on results of the pull-out test. Different types and behaviour of bamboo bonding reinforcement are studied and discussed. The study highlights the mechanical properties of bamboo as an alternative reinforcement in concrete and types of bamboo reinforced structural components. This reviews also compared the methodology adopted for surface treatment and preparation of bamboo reinforcement.

Evaluation of Strength and Water Susceptibility Performance of Polypropylene Fiber–Reinforced and Silica Fume–Modified Hot Mix Asphalt

Abstract The use of industrial recycled waste material has exponentially increased in past decades for green and sustainable construction practices. Numerous industrial wastes are being effectively used to replace the conventional construction material with paved structure construction. The use of industrial waste ash to replace the mineral filler and plastic waste as reinforcement has shown tremendous scope for use in hot mix asphalt (HMA). This research aims to explore the effect of alternative mineral filler and fiber reinforcement in HMA. In the present study, an extremely fine nanocrystalline polymorph of silica fume (SF) and polypropylene (PP) fiber was used as mineral filler and reinforcement. The varying percentages of SF (i.e., 4.0 %, 6.0 %, and 8.0 %) and PP fiber (0.25 %, 0.5 %, 0.75 %, and 1.0 %) by volume of total mix were used. The strength and durability of the HMA were evaluated using Marshall Stability, indirect tensile strength, mean Marshall Stability ratio, index of retained strength, water sensitivity, indirect tensile fatigue test, and rut depth tests. The statistical significance analysis has been carried out using the analysis of covariance. The loss of indirect tensile strength was observed between 16–18 % at the optimum limits of the SF and PP fiber; this signifies the higher durability of PP-fiber-reinforced HMA modified with SF. Ministry of Road Transport & Highways (MoRTH), 2013. The results also show the use of PP fiber and SF significantly improves the strength and durability of HMA.

Modelling of mid-rise concrete shear walls reinforced with superelastic shape memory alloys: Nonlinear analysis

The response of hybrid Shape Memory Alloy (SMA)-steel reinforced concrete shear walls containing Nickel-Titanium superelastic SMA as alternative reinforcement in the plastic hinge region was investigated using nonlinear finite element modelling. The hybrid wall system promotes self-centering and significant reduction of permanent deformations. Two types of conventional steel-reinforced concrete shear walls were designed for a prototype 10-storey office building according to the current Canadian concrete design standard, assuming two distinct seismic design scenarios. A moderately ductile shear wall was designed for a moderate seismic zone in eastern Canada, whereas a ductile shear wall was designed for a high seismic zone in western Canada. Equivalent, hybrid SMA-steel reinforced concrete shear walls were defined following the design of the two conventional shear walls, in terms of geometry and reinforcement layout. Full-scale, two-dimensional finite element models were developed to assess the pushover and hysteretic responses of the walls. Similarities in wall cross-section and yield force capacity of the steel and SMA reinforcement permitted a comparison between the walls, including strength, stiffness, self-centering, and energy dissipation capacities. The results indicate similar lateral strength and displacement capacities, and superior restoring capacity of the SMA-reinforced walls in comparison to the steel-reinforced walls. Furthermore, a preliminary study was conducted to investigate the effect of the SMA-bar length in the ductile wall due to concentration of damage near the base of the wall. Lengths corresponding to approximately 50% and 20% of the original SMA length were considered. Based on the analyses, a satisfactory response could be achieved with shorter SMA reinforcing bars, which reduces the quantity of SMA reinforcement without significant loss in self-centering capacity.

Microstructure and Mechanical Properties of Composites Obtained by Spark Plasma Sintering of Al–Fe66Cr10Nb5B19 Metallic Glass Powder Mixtures

At present, metallic glasses are evaluated as alternative reinforcements for aluminum matrix composites. These composites are produced by powder metallurgy via consolidation of metallic glass-aluminum powder mixtures. In most studies, the goal has been to preserve the glassy state of the reinforcement during consolidation. However, it is also of interest to track the structure evolution of these composites when partial interaction between the matrix and the metallic glass is allowed during sintering of the mixtures. The present work was aimed to study the microstructure and mechanical properties of composites obtained by spark plasma sintering (SPS) of Al-20 vol.% Fe66Cr10Nb5B19 metallic glass mixtures and compare the materials, in which no significant interaction between the matrix and the Fe-based alloy occurred, with those featuring reaction product layers of different thicknesses. Composite materials were consolidated by SPS at 540 and 570 °C. The microstructure and mechanical properties of composites obtained by SPS and SPS followed by forging, composites with layers of interfacial reaction products of different thicknesses, and metallic glass-free sintered aluminum were comparatively analyzed to conclude on the influence of the microstructural features of the composites on their strength.

Investigation on the thermal behaviour of AZ31B/waste eggshell surface composites produced by friction stir processing

The increasing demand for low-cost reinforcements emboldens the use of waste byproducts such as chicken eggshells. The chemical composition of the waste eggshell (contains 95% CaCo3) with low density, high hardness, high melting point and its easiest availability makes it a suitable alternative reinforcement to use in the metal matrix composites (MMCs). In this work, the ball-milled and carbonized waste chicken eggshell powder is used to develop the surface composites of magnesium alloy by friction stir processing. Developed material was validated by microscopic images of stir zone, thermomechanical affected zone, heat-affected zone and structural analysis by X-ray diffraction. The material is thermally characterized by thermal conductivity at varying temperatures (50 °C–400 °C) and varying terminal voltage (100 V–250 V), coefficient of thermal expansion along with differential thermal analysis, thermo-gravimetric analysis and derivative thermo-gravimetric analysis. The results revealed the decreasing trend of thermal conductivity and coefficient of thermal expansion, found in the range of 96 to 48 W/mK and 28.92 to 23.5 × 10-6 K-1, respectively at an increasing temperature from 50 °C to 400 °C and at increasing eggshell powder percentage.

Analysis of unexpected disruptive effects of contingent food reinforcement on automatically maintained self-injury.

Research has identified treatment-responsive and treatment-resistant subtypes of automatically maintained self-injurious behavior (ASIB) based on patterns of responding in the functional analysis (FA) reflecting its sensitivity to disruption by alternative reinforcement, and the presence of self-restraint. Rooker et al. (2019) unexpectedly observed reductions in treatment-resistant self-injury while participants performed an operant task. The current study further examined this in nine participants with treatment-resistant ASIB in an example of discovery-based research. An operant task engendering high rates of responding (switch-pressing) to produce food, reduced self-injury across all participants, and eliminated self-injury for some participants under certain schedules. Although this finding must be replicated and evaluated over longer time periods, it provides some evidence that alternative reinforcement can disrupt self-injury in these treatment-resistant subtypes under some conditions. Reinforcer and response competition are discussed as possible mechanisms underlying these disruptive effects, as are the potential implications of these findings regarding treatment.

Destructive behavior increases as a function of reductions in alternative reinforcement during schedule thinning: A retrospective quantitative analysis.

The behavioral processes determining the magnitude of the resurgence of destructive behavior during reinforcement schedule thinning have yet to be described, despite an uptick in prevalence research on the topic. As predicted by Resurgence as Choice theory, recent animal research has found that resurgence increases with the magnitude of a downshift in alternative reinforcement. Here we reanalyze the data from 2 recent prevalence studies to determine whether the size of the decrease in alternative reinforcement availability predicts the magnitude of resurgence in the clinic. Results from this retrospective analysis suggest that resurgence of destructive behavior increases significantly with decreases in the availability of alternative reinforcement. Implications for future research and translations of theoretical analyses to the clinic are discussed.

Effect of surface modification on mechanical properties of filature silk waste and nanoclay filler-based polymer matrix composite

Natural fibers have been attracting researchers and engineers as an alternative reinforcement of synthetic fibers in polymer composites due to their low cost, availability from natural resources, satisfactory high modulus and tensile strength, and biodegradability. Filature silk waste (FSW) is the remnant part of the cocoons which is produced during the silk forming process. The current study focuses on the comparison of tensile properties between untreated filature silk waste reinforced epoxy-based composite (UTFSWREC), 2 wt% alkali-treated filature silk waste reinforced epoxy-based composites (TFSWREC) and 2 wt% alkali-treated filature silk waste reinforced epoxy nanocomposites (TFSWRENC). The tensile properties showed that Young’s modulus of composites increases with surface modification of fiber and further enhances with nanoclay filler. TFSWREC and TFSWRENC displayed a higher tensile modulus than UTFSWREC. Scanning Electron Microscopy (SEM) showed the removal of the sericin layer from the surface of fiber, which resulted in the separation of fibrils and further resulted in the enhancement of the mechanical properties. FTIR analysis confirmed that intermolecular bonding improves with the chemical treatment and further refined with nanoclay filler addition.