Pointing behaviors of preschoolers during Logo mastery

Cursor pointing behavior was examined as a conceptual strategy used by preschoolers to guide their microcomputer manipulations. Thirty-eight 4- and 5-year old children, categorized by field independence/field dependence, were trained to an established criterion in Logo and then presented a series of Logo problems with a counterbalanced problem set in using three cursor types (standard triangular turtle cursor, cross-shaped cursor, and circular cursor). It was hypothesized that young children adopted an initial pointing strategy as the first of several developmental stages involved in Logo programming. Subjects were required to solve a sequence of Logo problems occurring equally within the four quadrants of a computer screen (upper-lower, right-left). Data were analyzed for keystrokes, errors, task closure, and task success by field dependence vs. field independence, treatment level, and quadrant

Values and other factors which influence consumer choice of a portable lamp

The purpose of this study was to determine: 1) the relative importance of personal, practical, and esthetic values as these related to the selection of a portable lamp; 2) the forms of deliberation preceding the purchase of the lamp; 3) the satisfaction with the purchased lamp; and 4) to examine the relationship of values, deliberation, satisfaction, and selected general information relevant to the lamp and its purchase. An interview schedule was designed by the researcher, pretested, and administered to fifty persons in and around Greenville, South Carolina, who had purchased a portable lamp within six months prior to the interview. The value types included practical, esthetic, and personal values. Other factors studied were husband-wife interaction in the choice, deliberation in the purchase, and satisfaction received from the purchase. Results of the study revealed that esthetic values were predominant; practical values were strong but secondary to esthetic values. Personal values, as identified by this study, were relatively unimportant to respondents. Esthetic values were predominant among both low and high income groups, among those respondents with a high school education or less, and among those 36 years of age and over. Practical values were dominant among those under 26 years old and with education beyond high school

Soft Heaps Visualized

The soft heap is an approximate priority queue data structure originally proposed by Bernard Chazelle [3]. Chazelle used it to develop the fastest deterministic algorithm to compute a minimum spanning tree of a connected graph [2]. The soft heap allows some items to become “corrupted”, in which their keys are artificially increased. This allows us to overcome the sorting lower bound in the comparison-based model of computation. However, some of the corrupted items exit the heap out of order. The number of corrupted items in the heap is upper-bounded by em, where e is an error rate determined by the user, and m is the number of insertions into the heap. This corruption allows soft heap operations to run in constant amortized time for a suitable e = O(1), making it ideal for applications where speed is prioritized over precision. Such applications include finding an approximate median of a set of items, and in dynamic maintenance of percentiles [3]. Chazelle’s initial implementation of the soft heap uses a collection of binomial heaps. This was simplified in both implementation and analysis, by Kaplan and Zwick [10], and later by Kaplan, Zwick, and Tarjan [9], both of which use binary heap-ordered trees instead. In this thesis, we develop a visualization tool to visualize the soft heap implementation of Kaplan, Zwick, and Tarjan. We also visualize three applications in which soft heaps are used. Our web-based tool can be easily extended to make visualizations of other complex data structures and algorithms. For completeness, we provide a new presentation of the implementation and the analysis of Kaplan, Zwick, and Tarjan’s soft heap data structure. We hope that our presentation, along with the visualization tool, makes complex data structures and algorithms more accessible to early (and intermediate) computer science students. Whereas existing implementations may corrupt items during both insertions and deletions, we provide a slight modification of the delete-min operation, to include only single fillings, and thereby not corrupt any more items during deletions in the soft heap. Thus, our modification allows the soft heap data structure to be used as a black box, where corruption only comes from the insert operation, and ensures that only at most em total items (either in the heap or removed) are corrupted

Hellfire and water

The poems collected here explore the familial roots of mental illness, sexuality, loss, and the points where they all converge

Cost-effectiveness of a novel lipoarabinomannan test for tuberculosis in patients with HIV

BACKGROUND: A novel urine lipoarabinomannan assay (FujiLAM) has higher sensitivity and higher cost than the first-generation AlereLAM assay. We evaluated the cost-effectiveness of FujiLAM for tuberculosis testing among hospitalized people with HIV irrespective of symptoms. METHODS: We used a microsimulation model to project clinical and economic outcomes of three testing strategies: 1) sputum Xpert MTB/RIF (Xpert); 2) sputum Xpert plus urine AlereLAM (Xpert+AlereLAM); 3) sputum Xpert plus urine FujiLAM (Xpert+FujiLAM). The modelled cohort matched that of a two-country clinical trial. We applied diagnostic yields from a retrospective study (yields for Xpert/Xpert+AlereLAM/Xpert+FujiLAM among those with CD4<200/µL: 33%/62%/70%; among those with CD4≥200/µL: 33%/35%/47%). Costs of Xpert/AlereLAM/FujiLAM were USD15/3/6 (South Africa) and USD25/3/6 (Malawi). Xpert+FujiLAM was considered cost-effective if its incremental cost-effectiveness ratio (USD/year-of-life saved) was <$940 (South Africa) and <$750 (Malawi). We varied key parameters in sensitivity analysis and performed a budget impact analysis of implementing FujiLAM countrywide. RESULTS: Compared with Xpert+AlereLAM, Xpert+FujiLAM increased life expectancy by 0.2 years for those tested in South Africa and Malawi. Xpert+FujiLAM was cost-effective in both countries. Xpert+FujiLAM for all patients remained cost-effective compared with sequential testing and CD4-stratified testing strategies. FujiLAM use added 3.5% (South Africa) and 4.7% (Malawi) to five-year healthcare costs of tested patients, primarily reflecting ongoing HIV treatment costs among survivors. CONCLUSIONS: FujiLAM with Xpert for tuberculosis testing in hospitalized people with HIV is likely to increase life expectancy and be cost-effective at the currently anticipated price in South Africa and Malawi. Additional studies should evaluate FujiLAM in clinical practice settings

Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells

It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions

Two novel human cytomegalovirus NK cell evasion functions target MICA for lysosomal degradation

NKG2D plays a major role in controlling immune responses through the regulation of natural killer (NK) cells, αβ and γδ T-cell function. This activating receptor recognizes eight distinct ligands (the MHC Class I polypeptide-related sequences (MIC) A andB, and UL16-binding proteins (ULBP)1–6) induced by cellular stress to promote recognition cells perturbed by malignant transformation or microbial infection. Studies into human cytomegalovirus (HCMV) have aided both the identification and characterization of NKG2D ligands (NKG2DLs). HCMV immediate early (IE) gene up regulates NKGDLs, and we now describe the differential activation of ULBP2 and MICA/B by IE1 and IE2 respectively. Despite activation by IE functions, HCMV effectively suppressed cell surface expression of NKGDLs through both the early and late phases of infection. The immune evasion functions UL16, UL142, and microRNA(miR)-UL112 are known to target NKG2DLs. While infection with a UL16 deletion mutant caused the expected increase in MICB and ULBP2 cell surface expression, deletion of UL142 did not have a similar impact on its target, MICA. We therefore performed a systematic screen of the viral genome to search of addition functions that targeted MICA. US18 and US20 were identified as novel NK cell evasion functions capable of acting independently to promote MICA degradation by lysosomal degradation. The most dramatic effect on MICA expression was achieved when US18 and US20 acted in concert. US18 and US20 are the first members of the US12 gene family to have been assigned a function. The US12 family has 10 members encoded sequentially through US12–US21; a genetic arrangement, which is suggestive of an ‘accordion’ expansion of an ancestral gene in response to a selective pressure. This expansion must have be an ancient event as the whole family is conserved across simian cytomegaloviruses from old world monkeys. The evolutionary benefit bestowed by the combinatorial effect of US18 and US20 on MICA may have contributed to sustaining the US12 gene family

Fats and Factors: Lipid Profiles Associate with Personality Factors and Suicidal History in Bipolar Subjects

Polyunsaturated fatty acids (PUFA) have shown efficacy in the treatment of bipolar disorder, however their specific role in treating the illness is unclear. Serum PUFA and dietary intakes of PUFA associate with suicidal behavior in epidemiological studies. The objective of this study was to assess serum n-3 and n-6 PUFA levels in bipolar subjects and determine possible associations with suicidal risk, including suicidal history and relevant personality factors that have been associated with suicidality. We studied 27 bipolar subjects using the NEO-PI to assess the big five personality factors, structured interviews to verify diagnosis and assess suicidal history, and lipomics to quantify n-3 and n-6 PUFA in serum. We found positive associations between personality factors and ratios of n-3 PUFA, suggesting that conversion of short chain to long chain n-3s and the activity of enzymes in this pathway may associate with measures of personality. Thus, ratios of docosahexaenoic acid (DHA) to alpha linolenic acid (ALA) and the activity of fatty acid desaturase 2 (FADS2) involved in the conversion of ALA to DHA were positively associated with openness factor scores. Ratios of eicosapentaenoic acid (EPA) to ALA and ratios of EPA to DHA were positively associated with agreeableness factor scores. Finally, serum concentrations of the n-6, arachidonic acid (AA), were significantly lower in subjects with a history of suicide attempt compared to non-attempters. The data suggest that specific lipid profiles, which are controlled by an interaction between diet and genetics, correlate with suicidal history and personality factors related to suicidal risk. This study provides preliminary data for future studies to determine whether manipulation of PUFA profiles (through diet or supplementation) can affect personality measures and disease outcome in bipolar subjects and supports the need for further investigations into individualized specific modulations of lipid profiles to add adjunctive value to treatment paradigms

Anemia of Inflammation Is Related to Cognitive Impairment among Children in Leyte, The Philippines

Past studies have demonstrated that iron deficiency anemia is related to deficits in cognitive fucntioning in children, and treating iron deficiency anemia with iron supplementation can improve cognition. Anemia of inflammation is another type of anemia caused by many diseases of lesser-developed countries including bacterial and parasitic infections. Anemia of inflammation is characterized by disordered iron metabolism, such that iron is sequestered in storage forms, preventing its use from tissues that require it. We hypothesized that decreased iron delivery to the brain in the context of anemia of inflammation might lead to decreased cognitive performance. This study found that children with anemia of inflammation had decreased cognitive performance in specific domains, compared to subjects with no anemia. True total body iron deficiency anemia was related to lower performance in the same domains. The only treatment option for anemia of inflammation is treatment of the underlying disease. Iron supplementation will not prevent cognitive deficits in children with anemia of inflammation. Interventions aimed towards maximizing the cognitive development of children in lesser-developed countries will need to focus on the prevention and treatment of bacterial and parasitic infections