What If? Paths Not Taken

I think the point of this exercise in counterfactual thinking is two-fold first, to recognize that not only have choices been made in the past that defined the character of what has happened and that different choices were possible and would have led to different outcomes, and, second, that we are currently making similar choices for the future. Today s choices obviously will have significant long-term consequences for space development. Decision-makers have an image of a desirable future when they make choices, but they also realize that the link between current choice and desired result is always uncertain. As the philosopher Yogi Berra is often quoted as having said, "making predictions is hard, especially when they are about the future.

Columbia's CORE

"Fall 2013""A first-person account of race relations in Columbia in the 1960s by John Logsdon, BS PA '63."Story by John Logsdon, as told to Kelsey Allen ; Photos courtesy of John Logsdo

Monographs in Aerospace History Series No. 11. Together in Orbit: The Origins of International Participation in the Space Station

This essay is a history and analysis of the steps leading to the origins of the space station partnership between the United States and its closest allies. It traces the process that led to the decision to invite other countries to participate in the project and their reasons for accepting that invitation. Not covered in this account are the difficult negotiations during the 1984-1988 period that led first to an initial set of agreements that allowed the prospective partners to work together during the early stages of the space station program and then to the final set of agreements creating the original space station partnership. Also, the 1993 invitation to the Russian Federation to join the original partners is not discussed, nor are the subsequent negotiations to revise the 1988 agreements

Exploring the Unknown: Selected Documents in the History of the U.S. Civilian Space Program

The documents selected for inclusion in this volume are presented in three chapters, each covering a particular aspect of the evolution of U.S. space exploration. These chapters address (1) the relations between the civilian space program of the United States and the space activities of other countries, (2) the relations between the U.S. civilian space program and the space efforts of national security organizations and the military, and (3) NASA's relations with industry and academic institutions

The Relationship among Caregiver Depressive Symptoms, Parenting Behavior, and Familycenter Care All

Background Parental depression has been associated with adverse child outcomes. However, the specific parenting behaviors that may result in such child outcomes and the effect of family-centered care (FCC) on positive parenting behavior of depressed parents has not previously been examined. Methods Data from the National Survey of Early Childhood Health was used (n = 2,068). Groups were stratified by the presence of parental depression and compared with regard to demographics and the mean number of specific positive parenting behaviors. Generalized linear models were developed based on testing whether individuals performed more or less than the median number of positive behaviors. Lastly, we tested whether depression independently predicted each outcome after adjustment for FCC, coping, social support, and ethnicity to evaluate if depression independently predicted each outcome after adjustment. Results No difference was found in demographic variables between parents who were depressed and not depressed. Parents who were not depressed performed significantly more routines (p = .036); reported coping better with parenting (p < .001); performed significantly less punitive behaviors (p = .022); and needed/had less social support (p = .002) compared with parents who were depressed. Individual items and scale scores were associated in the expected directions. FCC was independently associated with study variables but did not moderate the effect of depression. Conclusions These data identify specific parenting behaviors that differ between parents who report depressive symptoms compared with parents who do not have depressive symptoms. More targeted interventions coordinated through a medical home are needed for parents with depressive symptoms to reduce the child health disparities often associated with parental depression

Exploring the Unknown: Selected Documents in the History of the US Civilian Space Program

One of the most important developments of the twentieth century has been the movement of humanity into space with machines and people. The underpinnings of that movement -why it took the shape it did; which individuals and organizations were involved; what factors drove a particular choice of scientific objectives and technologies to be used; and the political, economic, managerial, and international contexts in which the events of the space age unfolded- are all important ingredients of this epoch transition from an earthbound to spacefaring people. This desire to understand the development of spaceflight in the United States sparked this documentary history series. 'Exploring the Unknown' is a multi-volume series containing a selection of key documents in history of the U.S. civil space program. This current volume, Volume III, focusing on the use of space for practical applications, prints 112 key documents on the history of satellite communications, remote sensing of earth, and space as an investment in economic growth, edited for ease of use. Each is introduced by a headnote providing context, bibliographical information, and background information necessary to understanding the document

Comparative transcriptome analysis of obligately asexual and cyclically sexual rotifers reveals genes with putative functions in sexual reproduction, dormancy, and asexual egg production

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in BMC Genomics 14 (2013): 412, doi:10.1186/1471-2164-14-412.Sexual reproduction is a widely studied biological process because it is critically important to the genetics, evolution, and ecology of eukaryotes. Despite decades of study on this topic, no comprehensive explanation has been accepted that explains the evolutionary forces underlying its prevalence and persistence in nature. Monogonont rotifers offer a useful system for experimental studies relating to the evolution of sexual reproduction due to their rapid reproductive rate and close relationship to the putatively ancient asexual bdelloid rotifers. However, little is known about the molecular underpinnings of sex in any rotifer species. We generated mRNA-seq libraries for obligate parthenogenetic (OP) and cyclical parthenogenetic (CP) strains of the monogonont rotifer, Brachionus calyciflorus, to identify genes specific to both modes of reproduction. Our differential expression analysis identified receptors with putative roles in signaling pathways responsible for the transition from asexual to sexual reproduction. Differential expression of a specific copy of the duplicated cell cycle regulatory gene CDC20 and specific copies of histone H2A suggest that such duplications may underlie the phenotypic plasticity required for reproductive mode switch in monogononts. We further identified differential expression of genes involved in the formation of resting eggs, a process linked exclusively to sex in this species. Finally, we identified transcripts from the bdelloid rotifer Adineta ricciae that have significant sequence similarity to genes with higher expression in CP strains of B. calyciflorus. Our analysis of global gene expression differences between facultatively sexual and exclusively asexual populations of B. calyciflorus provides insights into the molecular nature of sexual reproduction in rotifers. Furthermore, our results offer insight into the evolution of obligate asexuality in bdelloid rotifers and provide indicators important for the use of monogononts as a model system for investigating the evolution of sexual reproduction.This work was funded by National Institutes of Health Institute of General Medical Sciences (grant number 5R01GM079484, to JML and DMW)

SIVsm Quasispecies Adaptation to a New Simian Host

Despite the potential for infectious agents harbored by other species to become emerging human pathogens, little is known about why some agents establish successful cross-species transmission, while others do not. The simian immunodeficiency viruses (SIVs), certain variants of which gave rise to the human HIV-1 and HIV-2 epidemics, have demonstrated tremendous success in infecting new host species, both simian and human. SIVsm from sooty mangabeys appears to have infected humans on several occasions, and was readily transmitted to nonnatural Asian macaque species, providing animal models of AIDS. Here we describe the first in-depth analysis of the tremendous SIVsm quasispecies sequence variation harbored by individual sooty mangabeys, and how this diverse quasispecies adapts to two different host species—new nonnatural rhesus macaque hosts and natural sooty mangabey hosts. Viral adaptation to rhesus macaques was associated with the immediate amplification of a phylogenetically related subset of envelope (env) variants. These variants contained a shorter variable region 1 loop and lacked two specific glycosylation sites, which may be selected for during acute infection. In contrast, transfer of SIVsm to its natural host did not subject the quasispecies to any significant selective pressures or bottleneck. After 100 d postinfection, variants more closely representative of the source inoculum reemerged in the macaques. This study describes an approach for elucidating how pathogens adapt to new host species, and highlights the particular importance of SIVsm env diversity in enabling cross-species transmission. The replicative advantage of a subset of SIVsm variants in macaques may be related to features of target cells or receptors that are specific to the new host environment, and may involve CD4-independent engagement of a viral coreceptor conserved among primates