Brain mechanisms of arousal, attention and perception

Neural mechanisms underlying visual perception, arousal, and attention processes in man, cat, and monke

ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE : I. MPC-1 and X5563 Tumors

An electron microscope study was made of a series of transplanted MPC-1 plasma-cell tumors carried by BALB/c mice. Large numbers of particles similar in morphology to virus particles were present inside the endoplasmic reticulum of tumor plasma cells. Very few particles were seen outside the cells or in ultracentrifuged preparations of the plasma or ascites fluid. In very early tumors particles were occasionally seen free in the cytoplasm adjacent to finely granular material. In general, the distribution of these particles inside endoplasmic reticulum is similar in early and late tumors. A few transplanted X5563 tumors of C3H mice were also examined. Large numbers of particles were found in the region of the Golgi apparatus in late X5663 tumors. A newly described cytoplasmic structure of plasma cells, here called a "granular body," appears to be associated with the formation of the particles. Particles present in MPC-1 tumors are exclusively of a doughnut form, whereas some of those in the inclusions of the late X5563 tumors show a dense center. Normal plasma cells, produced by inoculation of a modified Freund adjuvant into BALB/c mice. have been compared morphologically with tumor plasma cells of both tumor lines

Organizational learning and emotion: constructing collective meaning in support of strategic themes

Missing in the organizational learning literature is an integrative framework that reflects the emotional as well as the cognitive dynamics involved. Here, we take a step in this direction by focusing in depth over time (five years) on a selected organization which manufactures electronic equipment for the office industry. Drawing on personal construct theory, we define organizational learning as the collective re-construal of meaning in the direction of strategically significant themes. We suggest that emotions arise as members reflect on progress or lack of progress in achieving organizational learning. Our evidence suggests that invalidation – where organizational learning fails to correspond with expectations – gives rise to anxiety and frustration, while validation – where organizational learning is aligned with or exceeds expectations – evokes comfort or excitement. Our work aims to capture the key emotions involved as organizational learning proceeds

Emplacement and high-temperature evolution of gabbros of the 16.5°N oceanic core complexes (Mid-Atlantic Ridge): Insights ito the compositional variability of the lower oceanic crust

This study reports the composition of the oceanic crust from the 16.5°N region of the Mid‐Atlantic Ridge, a spreading ridge segment characterized by a complex detachment fault system and three main oceanic core complexes (southern, central, and northern OCCs). Lithologies recovered from the core complexes include both greenschist facies and weathered pillow basalt, diabase, peridotite, and gabbro, while only weathered and fresh pillow basalt was dredged from the rift valley floor. The gabbros are compositionally bimodal, with the magmatic crust in the region formed by scattered intrusions of chemically primitive plutonic rocks (i.e., dunites and troctolites), associated with evolved oxide‐bearing gabbros. We use thermodynamic models to infer that this distribution is expected in regions where small gabbroic bodies are intruded into mantle peridotites. The occurrence of ephemeral magma chambers located in the lithospheric mantle enables large proportions of the melt to be erupted after relatively low degrees of fractionation. A large proportion of the dredged gabbros reveal evidence for deformation at high‐temperature conditions. In particular, chemical changes in response to deformation and the occurrence of very high‐temperature ultramylonites (>1000 °C) suggest that the deformation related to the oceanic detachment commenced at near‐solidus conditions. This event was likely associated with the expulsion of interstitial, evolved magmas from the crystal mush, a mechanism that enhanced the formation of disconnected oxide‐gabbro seams or layers often associated with crystal‐plastic fabrics in the host gabbros. This granulite‐grade event was soon followed by hydrothermal alteration revealed by the formation of amphibole‐rich veins at high‐temperature conditions (~900 °C)

Dysregulation of the Norepinephrine Transporter Sustains Cortical Hypodopaminergia and Schizophrenia-Like Behaviors in Neuronal Rictor Null Mice

A novel animal model highlights the link between Akt dysfunction, reduced cortical dopamine function, norepinephrine transporters, and schizophrenia-like behaviors

Sexually Antagonistic “Zygotic Drive” of the Sex Chromosomes

Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic “zygotic drive”, because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic “arms race” between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans

Coccidioidomycosis among Workers at an Archeological Site, Northeastern Utah

In 2001, an outbreak of acute respiratory disease occurred among persons working at a Native American archeological site at Dinosaur National Monument in northeastern Utah. Epidemiologic and environmental investigations were undertaken to determine the cause of the outbreak. A clinical case was defined by the presence of at least two of the following symptoms: self-reported fever, shortness of breath, or cough. Ten workers met the clinical case definition; 9 had serologic confirmation of coccidioidomycosis, and 8 were hospitalized. All 10 were present during sifting of dirt through screens on June 19; symptoms began 9–12 days later (median 10). Coccidioidomycosis also developed in a worker at the site in September 2001. A serosurvey among 40 other Dinosaur National Monument workers did not find serologic evidence of recent infection. This outbreak documents a new endemic focus of coccidioidomycosis, extending northward its known geographic distribution in Utah by approximately 200 miles

Expression in Aneuploid Drosophila S2 Cells

Analysis of the relationship between gene copy number and gene expression in aneuploid male Drosophila cells reveals a global compensation mechanism in addition to X chromosome-specific dosage compensation

Progress and prospects toward our understanding of the evolution of dosage compensation

In many eukaryotic organisms, gender is determined by a pair of heteromorphic sex chromosomes. Degeneration of the non-recombining Y chromosome is a general facet of sex chromosome evolution. Selective pressure to restore expression levels of X-linked genes relative to autosomes accompanies Y-chromosome degeneration, thus driving the evolution of dosage compensation mechanisms. This review focuses on evolutionary aspects of dosage compensation, in light of recent advances in comparative and functional genomics that have substantially increased our understanding of the molecular mechanisms of dosage compensation and how it evolved. We review processes involved in sex chromosome evolution, and discuss the dynamic interaction between Y degeneration and the acquisition of dosage compensation. We compare mechanisms of dosage compensation and the origin of dosage compensation genes between different taxa and comment on sex chromosomes that apparently lack compensation mechanisms. Finally, we discuss how dosage compensation systems can also influence the evolution of well-established sex chromosomes