Colloidal dynamics in polymer solutions: Optical two-point microrheology measurements

We present an extension of the two-point optical microrheology technique introduced by Crocker \textit{et al.} [Phys. Rev. Lett. \textbf{85}, 888 (2000)] to high frequencies. The correlated fluctuations of two probe spheres held by a pair of optical tweezers within a viscoelastic medium are determined using optical interferometry. A theoretical model is developed to yield the frequency-dependent one- and two-particle response functions from the correlated motion. We demonstrate the validity of this method by determining the one- and two-particle correlations in a semi-dilute solution of polystyrene in decalin. We find that the ratio of the one- and two-particle response functions is anomalous which we interpret as evidence for a slip boundary condition caused by depletion of polymer from the surface of the particle

On the effect of silicon and phosphorus during the precipitation of Κ-carbide in Fe-Mn-Al-C alloys

Implementation of lightweight high manganese and aluminum steels for use in high energy absorbing applications requires a detailed knowledge of how alloying additions and impurities affect age hardening and high strain rate fracture properties. Dynamic fracture toughness is an important design criterion but has not been reported previously in these alloys. In addition, previous studies have shown that silicon and phosphorus increased the strength and aged hardness; however, the mechanism was unknown. This research mainly focuses on the effect of silicon and phosphorus on the precipitation of Κ-carbide and alloy partitioning during aging. Short range ordering, SRO, of Fe-Al-C into relative atomic positions described by the E2₁ superlattice structure preceded and occurred concurrent to spinodal decomposition. Short range diffusion of phosphorus increased the kinetics of ordering resulting in a decrease in the time required for subsequent spinodal decomposition and an increase the amplitude of carbon concentration with time. Silicon increased the strength and hardness as a result of increased carbon partitioning into the Κ-carbide during aging. Dynamic fracture toughness was found to depend upon aluminum and carbon. Increasing the amount of solid solution carbon increased the dynamic fracture toughness in solution treated specimens. However, increasing carbon in aged specimens increased the amount of Κ-carbide and produced brittle fracture. Additions of aluminum from three to nine weight percent decreased toughness regardless of the heat treatment. Dynamic fracture toughness was a strong function of A1N content. A good combination of high strength and dynamic toughness with a corresponding density reduction of 10 to 12% is obtained with aluminum additions between 6 and 7% and carbon below 1.2% --Abstract, Page iv

Motion adaptation and attention: A critical review and meta-analysis

The motion aftereffect (MAE) provides a behavioural probe into the mechanisms underlying motion perception, and has been used to study the effects of attention on motion processing. Visual attention can enhance detection and discrimination of selected visual signals. However, the relationship between attention and motion processing remains contentious: not all studies find that attention increases MAEs. Our meta-analysis reveals several factors that explain superficially discrepant findings. Across studies (37 independent samples, 76 effects) motion adaptation was significantly and substantially enhanced by attention (Cohen's d = 1.12, p < .0001). The effect more than doubled when adapting to translating (vs. expanding or rotating) motion. Other factors affecting the attention-MAE relationship included stimulus size, eccentricity and speed. By considering these behavioural analyses alongside neurophysiological work, we conclude that feature-based (rather than spatial, or object-based) attention is the biggest driver of sensory adaptation. Comparisons between naïve and non-naïve observers, different response paradigms, and assessment of 'file-drawer effects' indicate that neither response bias nor publication bias are likely to have significantly inflated the estimated effect of attention

Kidney Cortex Lysosomal Acid Proteinase Activity during Induction of a Protein-Losing Nephropathy with the Aminonucleoside of Puromycin

Effects have been studied of induction of aminonucleoside-nephrosis in the rat on kidney cortex lysosomal acid proteinase activity (pH 3.2) and on such activity in the cytosol from which the lysosomes were isolated. In parallel with the onset of the massive proteinuria of the disease process but not preceding this effect, activity in the cytosol fraction was significantly increased. Significantly increased activity in the lysosomal fraction, on the other hand, was not observed until the proteinuria was well-established. Comparative study of the release of acid proteinase activity, from intact lysosomes isolated from normal and from aminonucleoslde-nephrotic rat kidneys, suggest-in the latter case-either increased permeability or increased lysis of lysosomal membranes, permitting release of the proteolytic activity. Absence of any in vivo or direct effect of aminonucleoside on the release of the acid proteinase from normal intact kidney lysosomes, however, cautions against this interpretation of the findings

Kidney Cortex Lysosomal Acid Proteinase Activity during Induction of a Protein-Losing Nephropathy with the Aminonucleoside of Puromycin

Effects have been studied of induction of aminonucleoside-nephrosis in the rat on kidney cortex lysosomal acid proteinase activity (pH 3.2) and on such activity in the cytosol from which the lysosomes were isolated. In parallel with the onset of the massive proteinuria of the disease process but not preceding this effect, activity in the cytosol fraction was significantly increased. Significantly increased activity in the lysosomal fraction, on the other hand, was not observed until the proteinuria was well-established. Comparative study of the release of acid proteinase activity, from intact lysosomes isolated from normal and from aminonucleoslde-nephrotic rat kidneys, suggest-in the latter case-either increased permeability or increased lysis of lysosomal membranes, permitting release of the proteolytic activity. Absence of any in vivo or direct effect of aminonucleoside on the release of the acid proteinase from normal intact kidney lysosomes, however, cautions against this interpretation of the findings

Validity and reliability of two abbreviated versions of the Gross Motor Function Measure.

Aim: The “gold standard” to measure gross motor functioning for children with cerebral palsy (CP) is the Gross Motor Function Measure (GMFM-66). The purpose of this study was to estimate the validity and reliability of two abbreviated versions (item set (GMFM-66 IS) and basal and ceiling (GMFM-66 B&C) approaches) of the GMFM-66. Methods: Twenty-six children with CP aged 2 to 6 years across all GMFCS levels participated. At session one, both abbreviated versions were administered by two independent raters, followed by the full GMFM-66. In the subsequent session, only the abbreviated versions were administered, by the same raters. Concurrent validity, comparability between versions and test-retest reliability were determined using intraclass correlation coefficients (ICC 2,1). Results: Both versions demonstrated high levels of validity with ICCs reflecting associations with the GMFM-66 of 0.99 (95% CIs ranging from 0.972-0.997). Both versions were also shown to be highly reliable with ICCs greater than 0.98 (95% CIs ranging from 0.965-0.994). Interpretation: Both versions can be used in clinical practice or research. However, the GMFM-66-B&C is recommended as the preferred abbreviated version

Profiles of Fatigue Severity and Variability Among Adolescents and Young Adults with Cerebral Palsy

Background: Individuals with cerebral palsy (CP) experience progressive changes in functional status with the development of secondary impairments such as fatigue. Detailed accounts of the fatigue experience in CP are lacking. Purpose: This study describes the severity and variability of fatigue in CP using the Fatigue Impact and Severity Self-Assessment. Methods: This was a descriptive cross-sectional study surveying 130 (61 males) individuals (mean age 18 years, 11 months; SD four years, six months) with CP. Analyses comprised comparisons between two groups (Gross Motor Function Classification System (GMFCS) I and II-V), frequency counts and proportions. Results: Significant differences exist between GMFCS groups for all fatigue severity questions. In addition, 38% of individuals classified as GMFCS level I reported their average fatigue as moderate to severe and 53% experienced fatigue on three or more days in the previous week. Sixty-eight percent of individuals classified as GMFCS II-V reported their average fatigue to be moderate to severe and 78% were fatigued on three or more days in the previous week. Conclusions: Fatigue is a highly individualized phenomenon with significant burden for individuals with CP regardless of functional ability. Individuals in GMFCS Levels II-V reported increased fatigue severity and would benefit from specific management interventions

Construction and validation of the fatigue impact and severity self-assessment for youth and young adults with cerebral palsy.

Purpose: The Fatigue Impact and Severity Self-Assessment (FISSA) was created to assess the impact, severity and self-management of fatigue for individuals with cerebral palsy (CP) aged 14-31. Methods Used: Items were generated from a review of measures and interviews with individuals with CP. Focus groups with healthcare professionals were used for item reduction. A mailed survey was conducted (n=163/367) to assess the factor structure, known-groups validity and test-retest reliability. Results Obtained: The final measure contained 31-items in two factors and discriminated between individuals expected to have different levels of fatigue. Individuals with more functional abilities reported less fatigue (p\u3c 0.002) and those with higher pain reported higher fatigue (p\u3c 0.001). The FISSA was shown to have adequate test-retest reliability, ICC(3,1)=0.74 (95% CI 0.53-0.87). Conclusions Reached: The FISSA valid and reliable for individuals with CP. It allows for identification of the activities that may be compromised by fatigue to enhance collaborative goal setting and intervention planning

Reflection/Reflected The Construction of Female Subjectivity in Elizabeth Bowen\u27s The Last September and The Death of the Heart

As I read Elizabeth Bowen\u27s The Last September and The Death of the Heart, questions arose, persisted, and remained unanswered until I undertook the project of applying poststructuralist theories to these novels. Reading The Last September, I puzzled over the female protagonist\u27s relationship to an ancillary character, which Bowen repeatedly represents in terms of the father-daughter relationship. Reading both The Last September and The Death of the Heart, I was struck by the fact that although Bowen is typically categorized as a classical realist, she embarks upon the quest of depicting the identity construction of two female adolescents but abandons the representations of her main characters at the end of each novel—without completion or explication. Finally, I noticed in each novel remarkable attention to the relationship between language and identity. Particularly, in The Death of the Heart, explicit attention is given to the female\u27s role as author. I questioned the presence of these ambiguous, disconcerting issues in novels by a classical realist. None of these issues has been specifically addressed by Bowen\u27s critics, but by applying poststructuralist theories to these novels I acquired insights which answer my questions. Primarily, I have relied upon the psychoanalytic theories of Jacques Lacan, but I have also applied a multitude of theories provided by feminist and deconstructionalist theorists. I do not assume that Bowen wrote her novels with an awareness or conscious complicity with these theories, but I do suggest that these novels raise issues which poststructuralist theories provide an unprecedented lens to observe and address. While Bowen, obviously, did not have access to these specific theories, the issues which they address were indisputably a factor in her life. As an Anglo-Irish female author, she faced the implication of oppositional terms which construct identity. In Ireland, she was perceived as a colonizer, in England as one of the colonized, and as a female in the first half of the twentieth century she, faced the dichotomous roles defining her as both wife and author. Psychoanalytic and feminist theory address these issues: psychoanalytic theory reveals the intersection of language/culture, gender, and identity; feminist theory illuminates the hierarchical oppositions within patriarchal discourse which structure our thinking and influence behavior. I do not presume that my application of these theories to The Last September and The Death of the Heart provides a totalizing reading of the novels. Inevitably these theories will fall out of out of vogue and new theories will replace them. Further, while I have not read these novels in a purely historical context, the theories which I use are grounded in a particular historical/ social circumstance. Lacanian theory, for example, is not of an ahistorical, universal language, but is a theory of the structures of language and identity within a specific cultural/ historical framework. However, recognition of the temporality of the theories I employ does not render my reading irrelevant or dismissable. While recognition of the hierarchical ordering structures within patriarchal discourse will modify these structures—perhaps, for example, the male/phallus will not always be the dominant signifier—the notion that language is a mediator of our beliefs and identity will endure

Computational scientific discovery in psychology

Scientific discovery is a driving force for progress, involving creative problem-solving processes to further our understanding of the world. Historically, the process of scientific discovery has been intensive and time-consuming; however, advances in computational power and algorithms have provided an efficient route to make new discoveries. Complex tools using artificial intelligence (AI) can efficiently analyse data as well as generate new hypotheses and theories. Along with AI becoming increasingly prevalent in our daily lives and the services we access, its application to different scientific domains is becoming more widespread. For example, AI has been used for early detection of medical conditions, identifying treatments and vaccines (e.g., against COVID-19), and predicting protein structure. The application of AI in psychological science has started to become popular. AI can assist in new discoveries both as a tool that allows more freedom to scientists to generate new theories, and by making creative discoveries autonomously. Conversely, psychological concepts such as heuristics have refined and improved artificial systems. With such powerful systems, however, there are key ethical and practical issues to consider. This review addresses the current and future directions of computational scientific discovery generally and its applications in psychological science more specifically