A qualitative investigation of adolescents’ perceived mechanisms of change from a universal school-based depression prevention program

A recent meta-analysis provides evidence supporting the universal application of school-based prevention programs for adolescent depression. The mechanisms underlying such successful interventions, however, are largely unknown. We report on a qualitative analysis of 109 Grade 9 students’ beliefs about what they gained from an evidence-based depression prevention intervention, the Resourceful Adolescent Program (RAP-A). Fifty-four percent of interviewees articulated at least one specific example of program benefit. A thematic analysis of responses revealed two major themes, improved interpersonal relationships and improved self-regulation, both stronger than originally assumed. A more minor theme also emerged—more helpful cognitions. It is postulated that both improved interpersonal relationships and improved self-regulation are likely to enhance one another, and more helpful cognitions may express its contribution through enhanced self-regulation. These findings broaden our understanding of the impact of depression prevention programs, beginning to illuminate how such programs benefit participants.

Mechanisms of change in psychotherapy for people diagnosed with schizophrenia : the role of narrative reflexivity in promoting recovery

Narrative reflexivity was investigated as a potential mechanism of therapeutic change during a 12 - 18 month trial of Metacognitive Narrative Psychotherapy for people diagnosed with schizophrenia. Participants were nine adult clients (8 male, 1 female) aged between 25-65 years (M = 44, SD = 12.76) with a diagnosis of schizophrenia consistent with DSM-IV criteria and seven female provisional psychologists aged between 25-29 years (M = 26.8 years, SD = 1.47 years). Recovery and narrative reflexivity were measured at three time points using the Recovery Assessment Scale (RAS) and the Narrative Processes Coding System (NPCS). Results were reported descriptively due to limited sample size (n = 9). The majority of clients (n = 7) reported an increase in recovery over the course of treatment. For six clients, an overall increase in recovery was associated with an increase in narrative reflexivity. This study provides preliminary support for narrative reflexivity as a potential mechanism of therapeutic change in the psychotherapy of people diagnosed with schizophrenia.

An amendment to the rehabilitation skills inventory

In this investigation of rehabilitation professionals in Australasia, where the profession of rehabilitation counseling might be described as emerging, the appropriateness of the Rehabilitation Skills Inventory for use in Australasian settings was evaluated. This resulted in an amendment to the original instrument and the development of the RSI (Amended) instrument. The instrument validation is discussed and the four component solution described.

Carbon nanorods and graphene-like nanosheets by hot filament CVD : growth mechanisms and electron field emission

Carbon nanorods and graphene-like nanosheets are catalytically synthesized in a hot filament chemical vapor deposition system with and without plasma enhancement, with gold used as a catalyst. The morphological and structural properties of the carbon nanorods and nanosheets are investigated by field-emission scanning electron microscopy, transmission electron microscopy and micro-Raman spectroscopy. It is found that carbon nanorods are formed when a CH4 + H2 + N2 plasma is present while carbon nanosheets are formed in a methane environment without a plasma. The formation of carbon nanorods and carbon nanosheets are analyzed. The results suggest that the formation of carbon nanorods is primarily a precipitation process while the formation of carbon nanosheets is a complex process involving surface-catalysis, surface diffusion and precipitation influenced by the Gibbs–Thomson effect. The electron field emission properties of the carbon nanorods and graphene-like nanosheets are measured under high-vacuum; it is found that the carbon nanosheets have a lower field emission turn-on than the carbon nanorods. These results are important to improve the understanding of formation mechanisms of carbon nanomaterials and contribute to eventual applications of these structures in nanodevices.

Proteins, drug targets and the mechanisms they control : the simple truth about complex networks

Realizing the promise of molecularly targeted inhibitors for cancer therapy will require a new level of knowledge about how a drug target is wired into the control circuitry of a complex cellular network. Here we review general homeostatic principles of cellular networks that enable the cell to be resilient in the face of molecular perturbations, while at the same time being sensitive to subtle input signals. Insights into such mechanisms may facilitate the development of combination therapies that take advantage of the cellular control circuitry, with the aim of achieving higher efficacy at a lower drug dosage and with a reduced probability of drug-resistance development.

Temperature-dependent growth mechanisms of low-dimensional ZnO nanostructures

One-dimensional ZnO nanostructures were successfully synthesized on single-crystal silicon substrates via a simple thermal evaporation and vapour-phase transport method under different process temperatures from 500 to 1000 °C. The detailed and in-depth analysis of the experimental results shows that the growth of ZnO nanostructures at process temperatures of 500, 800, and 1000 °C is governed by different growth mechanisms. At a low process temperature of 500 °C, the ZnO nanostructures feature flat and smooth tips, and their growth is primarily governed by the vapour-solid mechanism. At an intermediate process temperature of 800 °C, the ZnO nanostructures feature cone-shape tips, and their growth is primarily governed by the self-catalyzed and saturated vapour–liquid–solid mechanism. At a high process temperature of 1000 °C, the alloy tip appears on the front side of the ZnO nanostructures, and their growth is primarily governed by the common catalyst-assisted vapour–liquid–solid mechanism. It is also shown that the morphological, structural, optical, and compositional properties of the synthesized ZnO nanostructures are closely related to the process temperature. These results are highly relevant to the development of light-emitting diodes, chemical sensors, energy conversion devices, and other advanced applications.

Controlled electronic transport in single-walled carbon nanotube networks : selecting electron hopping and chemical doping mechanisms

The electronic transport in both intrinsic and acid-treated single-walled carbon nanotube networks containing more than 90% semiconducting nanotubes is investigated using temperature-dependent resistance measurements. The semiconducting behavior observed in the intrinsic network is attributed to the three-dimensional electron hopping mechanism. In contrast, the chemical doping mechanism in the acid-treated network is found to be responsible for the revealed metal-like linear resistivity dependence in a broad temperature range. This effective method to control the electrical conductivity of single-walled carbon nanotube networks is promising for future nanoscale electronics, thermometry, and bolometry. © 2010 American Institute of Physics.

Mechanisms of sulfide ion oxidation during cyanidation. Part II : Surface catalysis by pyrite

The mechanisms and the reaction products for the oxidation of sulfide ions in the presence of pyrite have been established. When the leach solution contains free sulfide ions, oxidation occurs via electron transfer from the sulfide ion to dissolved oxygen on the pyrite mineral surface, with polysulfides being formed as an intermediate oxidation product. In the absence of cyanide, the polysulfides are further oxidised to thiosulfate, whilst with cyanide present, thiocyanate and sulfite are also formed from the reaction of polysulfides with cyanide and dissolved oxygen. Polysulfide chain length has been shown to affect the final reaction products of polysulfide oxidation by dissolved oxygen. The rate of pyrite catalysed sulfide ion oxidation was found to be slower in cyanide solutions compared to cyanide free solutions. Mixed potential measurements indicated that the reduction of oxygen at the pyrite surface is hindered in the presence of cyanide. The presence of sulfide ions was also found to activate the pyrite surface, increasing its rate of oxidation by oxygen. This effect was particularly evident in the presence of cyanide; in the presence of sulfide the increase in total sulfur from pyrite oxidation was 2.3 mM in 7 h, compared to an increase of <1 mM in the absence of sulfide over 24 h.

Reliability of a wellness inventory for use among adolescent females aged 12-14 years

Background The wellness construct has application in a number of fields including education, healthcare and counseling, particularly with regard to female adolescents. The effective measurement of wellness in adolescents can assist researchers and practitioners in determining lifestyle behaviors in which they are lacking. Behavior change interventions can then be designed which directly aid in the promotion of these areas. Methods The 5-Factor Wellness Inventory (designed to measure the Indivisible Self model of wellness) is a popular instrument for measuring the broad aspects of wellness amongst adolescents. The instrument comprises 97 items contributing to 17 subscales, five dimension scores, four context scores, total wellness score, and a life satisfaction index. This investigation evaluated the test-retest (intra-rater) reliability of the 5 F-Wel instrument in repeated assessments (seven days apart) among adolescent females aged 12-14 years. Percentages of exact agreement for individual items, and the number of respondents who scored within +/-5, +/-7.5 and +/-10 points for total wellness and the five summary dimension scores were calculated. Results Overall, 46 (95.8%) participants responded with complete data and were included in the analysis. Item agreement ranged from 47.8% to 100% across the 97 items (median 69.9%, interquartile range 60.9%-73.9%). The percentage of respondents who scored within +/-5, +/-7.5 and +/-10 points for total wellness at the re-assessment was 87.0%, 97.8% and 97.8% respectively. The percentage of respondents who scored within +/-5, +/-7.5 and +/-10 for the domain scores at the reassessment ranged between 54.3-76.1%, 78.3-95.7% and 89.1-95.7% respectively across the five dimensions. Conclusions These findings suggest there was considerable variation in agreement between the two assessments on some individual items. However, the total wellness score and the five dimension summary scores remained comparatively stable between assessments.

A meshfree particle based model for microscale shrinkage mechanisms of food materials in drying conditions

Cells are the fundamental building block of plant based food materials and many of the food processing born structural changes can fundamentally be derived as a function of the deformations of the cellular structure. In food dehydration the bulk level changes in porosity, density and shrinkage can be better explained using cellular level deformations initiated by the moisture removal from the cellular fluid. A novel approach is used in this research to model the cell fluid with Smoothed Particle Hydrodynamics (SPH) and cell walls with Discrete Element Methods (DEM), that are fundamentally known to be robust in treating complex fluid and solid mechanics. High Performance Computing (HPC) is used for the computations due to its computing advantages. Comparing with the deficiencies of the state of the art drying models, the current model is found to be robust in replicating drying mechanics of plant based food materials in microscale.

Mechanisms of mono- and poly-ubiquitination : ubiquitination specificity depends on compatibility between the E2 catalytic core and amino acid residues proximal to the lysine

Ubiquitination involves the attachment of ubiquitin to lysine residues on substrate proteins or itself, which can result in protein monoubiquitination or polyubiquitination. Ubiquitin attachment to different lysine residues can generate diverse substrate-ubiquitin structures, targeting proteins to different fates. The mechanisms of lysine selection are not well understood. Ubiquitination by the largest group of E3 ligases, the RING-family E3 s, is catalyzed through co-operation between the non-catalytic ubiquitin-ligase (E3) and the ubiquitin-conjugating enzyme (E2), where the RING E3 binds the substrate and the E2 catalyzes ubiquitin transfer. Previous studies suggest that ubiquitination sites are selected by E3-mediated positioning of the lysine toward the E2 active site. Ultimately, at a catalytic level, ubiquitination of lysine residues within the substrate or ubiquitin occurs by nucleophilic attack of the lysine residue on the thioester bond linking the E2 catalytic cysteine to ubiquitin. One of the best studied RING E3/ E2 complexes is the Skp1/Cul1/F box protein complex, SCFCdc4, and its cognate E2, Cdc34, which target the CDK inhibitor Sic1 for K48-linked polyubiquitination, leading to its proteasomal degradation. Our recent studies of this model system demonstrated that residues surrounding Sic1 lysines or lysine 48 in ubiquitin are critical for ubiquitination. This sequence-dependence is linked to evolutionarily conserved key residues in the catalytic region of Cdc34 and can determine if Sic1 is mono- or poly-ubiquitinated. Our studies indicate that amino acid determinants in the Cdc34 catalytic region and their compatibility to those surrounding acceptor lysine residues play important roles in lysine selection. This may represent a general mechanism in directing the mode of ubiquitination in E2 s.

Epigenetic mechanisms mediating vulnerability and resilience to psychiatric disorders

The impact that stressful encounters have upon long-lasting behavioural phenotypes is varied. Whereas a significant proportion of the population will develop "stress-related" conditions such as post-traumatic stress disorder or depression in later life, the majority are considered "resilient" and are able to cope with stress and avoid such psychopathologies. The reason for this heterogeneity is undoubtedly multi-factorial, involving a complex interplay between genetic and environmental factors. Both genes and environment are of critical importance when it comes to developmental processes, and it appears that subtle differences in either of these may be responsible for altering developmental trajectories that confer vulnerability or resilience. At the molecular level, developmental processes are regulated by epigenetic mechanisms, with recent clinical and pre-clinical data obtained by ourselves and others suggesting that epigenetic differences in various regions of the brain are associated with a range of psychiatric disorders, including many that are stress-related. Here we provide an overview of how these epigenetic differences, and hence susceptibility to psychiatric disorders, might arise through exposure to stress-related factors during critical periods of development.

Mathematical Models of Tumor-Immune System Dynamics

"This collection of papers offers a broad synopsis of state-of-the-art mathematical methods used in modeling the interaction between tumors and the immune system. These papers were presented at the four-day workshop on Mathematical Models of Tumor-Immune System Dynamics held in Sydney, Australia from January 7th to January 10th, 2013. The workshop brought together applied mathematicians, biologists, and clinicians actively working in the field of cancer immunology to share their current research and to increase awareness of the innovative mathematical tools that are applicable to the growing field of cancer immunology. Recent progress in cancer immunology and advances in immunotherapy suggest that the immune system plays a fundamental role in host defense against tumors and could be utilized to prevent or cure cancer. Although theoretical and experimental studies of tumor-immune system dynamics have a long history, there are still many unanswered questions about the mechanisms that govern the interaction between the immune system and a growing tumor. The multidimensional nature of these complex interactions requires a cross-disciplinary approach to capture more realistic dynamics of the essential biology. The papers presented in this volume explore these issues and the results will be of interest to graduate students and researchers in a variety of fields within mathematical and biological sciences."--Publisher website

Nanomorphology influence on the light conversion mechanisms in highly efficient diketopyrrolopyrrole based organic solar cells

In this work, diketopyrrolopyrrole-based polymer bulk heterojunction solar cells with inverted and regular architecture have been investigated. The influence of the polymer:fullerene ratio on the photoactive film nanomorphology has been studied in detail. Transmission Electron Microscopy and Atomic Force Microscopy reveal that the resulting film morphology strongly depends on the fullerene ratio. This fact determines the photocurrent generation and governs the transport of free charge carriers. Slight variations on the PCBM ratio respect to the polymer show great differences on the electrical behavior of the solar cell. Once the polymer:fullerene ratio is accurately adjusted, power conversion efficiencies of 4.7% and 4.9% are obtained for inverted and regular architectures respectively. Furthermore, by correlating the optical and morphological characterization of the polymer:fullerene films and the electrical behavior of solar cells, an ad hoc interpretation is proposed to explain the photovoltaic performance as a function of this polymer:blend composition.