Mrs. Arthur W. Vandenberg

On verso: Mabel Allen; Apt.3, The Brentwood; 25 Lafayette Ave., S.E.; Grand Rapids 3, Michigan

Dosentin raivo

Kommentti kirja-arvosteluun: Kehittyykö tekniikka sääntöjen mukaisesti? / Panu Nykänen (Tieteessä tapahtuu 2/2011).

Kehittyykö tekniikka sääntöjen mukaisesti?

Kirjallisuusarvostelu

Separating Myth from Probability: the Origins and Evolution of QWERTY

We use basic probability theory and simple replicable electronic search experiments to evaluate some reported “myths” surrounding the origins and evolution of the QWERTY standard. The resulting evidence is strongly supportive of arguments put forward by Paul A. David (1985) and W. Brian Arthur (1989) that QWERTY was path dependent with its course of development strongly influenced by specific historical circumstances. The results also include the unexpected finding that QWERTY was as close to an optimal solution to a serious but transient problem as could be expected with the resources at the disposal of its designers in 1873.

Genomewide Linkage Scan of 409 European-ancestry and African American Families with Schizophrenia: Suggestive Evidence of Linkage at 8p23.3-p21.2 and 11p13.1-q14.1 in the Combined Sample

We report the clinical characteristics of a schizophrenia sample of 409 pedigrees-263 of European ancestry ( EA) and 146 of African American ancestry ( AA)-together with the results of a genome scan ( with a simple tandem repeat polymorphism interval of 9 cM) and follow-up fine mapping. A family was required to have a proband with schizophrenia ( SZ) and one or more siblings of the proband with SZ or schizoaffective disorder. Linkage analyses included 403 independent full-sibling affected sibling pairs ( ASPs) ( 279 EA and 124 AA) and 100 all-possible half-sibling ASPs ( 15 EA and 85 AA). Nonparametric multipoint linkage analysis of all families detected two regions with suggestive evidence of linkage at 8p23.3-q12 and 11p11.2-q22.3 ( empirical Z likelihood-ratio score [ Z(lr)] threshold >= 2.65) and, in exploratory analyses, two other regions at 4p16.1-p15.32 in AA families and at 5p14.3-q11.2 in EA families. The most significant linkage peak was in chromosome 8p; its signal was mainly driven by the EA families. Z(lr) scores >= 2.0 in 8p were observed from 30.7 cM to 61.7 cM ( Center for Inherited Disease Research map locations). The maximum evidence in the full sample was a multipoint Z(lr) of 3.25 ( equivalent Kong-Cox LOD of 2.30) near D8S1771 ( at 52 cM); there appeared to be two peaks, both telomeric to neuregulin 1 ( NRG1). There is a paracentric inversion common in EA individuals within this region, the effect of which on the linkage evidence remains unknown in this and in other previously analyzed samples. Fine mapping of 8p did not significantly alter the significance or length of the peak. We also performed fine mapping of 4p16.3-p15.2, 5p15.2-q13.3, 10p15.3-p14, 10q25.3-q26.3, and 11p13-q23.3. The highest increase in Z(lr) scores was observed for 5p14.1-q12.1, where the maximum Z(lr) increased from 2.77 initially to 3.80 after fine mapping in the EA families.

Mapping cortical change in Alzheimer's disease, brain development, and schizophrenia

This paper describes algorithms that can identify patterns of brain structure and function associated with Alzheimer's disease, schizophrenia, normal aging, and abnormal brain development based on imaging data collected in large human populations. Extraordinary information can be discovered with these techniques: dynamic brain maps reveal how the brain grows in childhood, how it changes in disease, and how it responds to medication. Genetic brain maps can reveal genetic influences on brain structure, shedding light on the nature-nurture debate, and the mechanisms underlying inherited neurobehavioral disorders. Recently, we created time-lapse movies of brain structure for a variety of diseases. These identify complex, shifting patterns of brain structural deficits, revealing where, and at what rate, the path of brain deterioration in illness deviates from normal. Statistical criteria can then identify situations in which these changes are abnormally accelerated, or when medication or other interventions slow them. In this paper, we focus on describing our approaches to map structural changes in the cortex. These methods have already been used to reveal the profile of brain anomalies in studies of dementia, epilepsy, depression, childhood and adult-onset schizophrenia, bipolar disorder, attention-deficit/ hyperactivity disorder, fetal alcohol syndrome, Tourette syndrome, Williams syndrome, and in methamphetamine abusers. Specifically, we describe an image analysis pipeline known as cortical pattern matching that helps compare and pool cortical data over time and across subjects. Statistics are then defined to identify brain structural differences between groups, including localized alterations in cortical thickness, gray matter density (GMD), and asymmetries in cortical organization. Subtle features, not seen in individual brain scans, often emerge when population-based brain data are averaged in this way. Illustrative examples are presented to show the profound effects of development and various diseases on the human cortex. Dynamically spreading waves of gray matter loss are tracked in dementia and schizophrenia, and these sequences are related to normally occurring changes in healthy subjects of various ages. (C) 2004 Published by Elsevier Inc.

A double-quadrature radiofrequency coil design for proton-decoupled carbon-13 magnetic resonance spectroscopy in humans at 7T

Purpose Carbon-13 magnetic resonance spectroscopy (13C-MRS) is challenging because of the inherent low sensitivity of 13C detection and the need for radiofrequency transmission at the 1H frequency while receiving the 13C signal, the latter requiring electrical decoupling of the 13C and 1H radiofrequency channels. In this study, we added traps to the 13C coil to construct a quadrature-13C/quadrature-1H surface coil, with sufficient isolation between channels to allow simultaneous operation at both frequencies without compromise in coil performance. Methods Isolation between channels was evaluated on the bench by measuring all coupling parameters. The quadrature mode of the quadrature-13C coil was assessed using in vitro 23Na gradient echo images. The signal-to-noise ratio (SNR) was measured on the glycogen and glucose resonances by 13C-MRS in vitro, compared with that obtained with a linear-13C/quadrature-1H coil, and validated by 13C-MRS in vivo in the human calf at 7T. Results Isolation between channels was better than â^'30 dB. The 23Na gradient echo images indicate a region where the field is strongly circularly polarized. The quadrature coil provided an SNR enhancement over a linear coil of 1.4, in vitro and in vivo. Conclusion It is feasible to construct a double-quadrature 13C-1H surface coil for proton decoupled sensitivity enhanced 13C-NMR spectroscopy in humans at 7T. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.

Aggregation of integrins and RhoA activation are required for Thy-1-induced morphological changes in astrocytes.

Thy-1, a cell adhesion molecule abundantly expressed in mammalian neurons, binds to a beta(3)-containing integrin on astrocytes and thereby stimulates the assembly of focal adhesions and stress fibers. Such events lead to morphological changes in astrocytes that resemble those occurring upon injury in the brain. Extracellular matrix proteins, typical integrin ligands, bind to integrins and promote receptor clustering as well as signal transduction events that involve small G proteins and cytoskeletal changes. Here we investigated the possibility that the cell surface protein Thy-1, when interacting with a beta(3)-containing integrin on astrocytes, could trigger signaling events similar to those generated by extracellular matrix proteins. DI-TNC(1) astrocytes were stimulated with Thy-1-Fc immobilized on beads, and increased RhoA activity was confirmed using an affinity precipitation assay. The effect of various inhibitors on the cellular response was also studied. The presence of Y-27632, an inhibitor of Rho kinase (p160ROCK), a key downstream effector of RhoA, significantly reduced focal adhesion and stress fiber formation induced by Thy-1. Similar effects were obtained when astrocytes were treated with C3 transferase, an inhibitor of RhoA. Alternatively, astrocytes were transfected with an expression vector encoding fusion proteins of enhanced green fluorescent protein with either the Rho-binding domain of Rhotekin, which blocks RhoA function, or the dominant-negative N19RhoA mutant. In both cases, Thy-1-induced focal adhesion formation was inhibited. Furthermore, we observed that RhoA activity after stimulation with soluble Thy-1-Fc molecule was augmented upon further cross-linking using protein A-Sepharose beads. The same was shown by cross-linking beta(3)-containing integrin with anti-beta(3) antibodies. Together, these results indicate that Thy-1-mediated astrocyte stimulation depended on beta(3) integrin clustering and the resulting increase in RhoA activity.

Prototypical Arthropod Gene Content and Genome Organisation in the Centipede Strigamia maritima

Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.

Prevalência de leptospirose em caprinos leiteiros do semiárido paraibano

Este trabalho teve como objetivos determinar a prevalência de propriedades de caprinos leiteiros positivas e de animais soropositivos para leptospirose no semiárido paraibano. A amostragem foi delineada para a determinação da prevalência de propriedades positivas (focos) e de animais soropositivos para a infecção por Leptospira spp. No total, foram colhidas amostras de sangue de 975 animais procedentes de 110 propriedades leiteiras localizadas no Munícipio de Monteiro, microrregião do Cariri Ocidental, Estado da Paraíba. Para o diagnóstico da infecção por Leptospira spp., foi utilizado o teste de soroaglutinação microscópica (SAM), utilizando como antígenos 24 sorovares. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. As prevalências de propriedades positivas e de animais soropositivos foram de 43,6% (IC 95% = 34,2-53,4%) e de 8,7% (IC 95% = 5,7-12,9%), respectivamente. Nos animais, os sorovares mais frequentes foram Autumnalis (1,74%; IC 95% = 0,97-3,09%), Sentot (1,71%; IC 95% = 0,82-3,52%) e Whitcomb (1,39%; IC 95% = 0,65-2,93%), e nas propriedades, os sorovares Autumnalis (10,9%; IC 95% = 5,8-18,3%), Whitcomb (8,2%; IC 95% = 3,8-15,0%) e Sentot e Patoc (7,3%; IC 95% = 3,2-13,8%) foram os mais frequentes. Sugere-se que a infecção está distribuída em caprinos da região, e que há necessidade de implantação de medidas de controle e prevenção, com o intuito de reduzir a ocorrência da infecção e, consequentemente, diminuir perdas econômicas ocasionadas e bloquear a possível transmissão do agente aos seres humanos.