Influence of Water Depth on the Rate of Expansion of Giant Cutgrass Populations and Management Implications

Giant cutgrass ( Zizaniopsis miliacea (Michx.) Doell. & Asch.), a tall emergent grass native to the southeastern United States, was studied in Lake Seminole where it formed large expanding stands, and Lake Alice where it was confined to a stable narrow fringe

The Dynamical Implications of Multiple Stellar Formation Events in Galactic Globular Clusters

Various galactic globular clusters display abundance anomalies that affect the morphology of their colour-magnitude diagrams. In this paper we consider the possibility of helium enhancement in the anomalous horizontal branch of NGC 2808. We examine the dynamics of a self-enrichment scenario in which an initial generation of stars with a top-heavy initial mass function enriches the interstellar medium with helium via the low-velocity ejecta of its asymptotic giant branch stars. This enriched medium then produces a second generation of stars which are themselves helium-enriched. We use a direct N-body approach to perform five simulations and conclude that such two-generation clusters are both possible and would not differ significantly from their single-generation counterparts on the basis of dynamics. We find, however, that the stellar populations of such clusters would differ from single-generation clusters with a standard initial mass function and in particular would be enhanced in white dwarf stars. We conclude, at least from the standpoint of dynamics, that two-generation globular clusters are feasible.Comment: 24 pages, 7 figures, 3 tables. Accepted for publication in Ap

Constraining global properties of the Draco dwarf spheroidal galaxy

By fitting a flexible stellar anisotropy model to the observed surface brightness and line-of-sight velocity dispersion profiles of Draco we derive a sequence of cosmologically plausible two-component (stars + dark matter) models for this galaxy. The models are consistent with all the available observations and can have either cuspy Navarro-Frenk-White or flat-cored dark matter density profiles. The dark matter halos either formed relatively recently (at z~2...7) and are massive (up to ~5x10^9 M_Sun), or formed before the end of the reionization of the universe (z~7...11) and are less massive (down to ~7x10^7 M_Sun). Our results thus support either of the two popular solutions of the "missing satellites" problem of Lambda cold dark matter cosmology - that dwarf spheroidals are either very massive, or very old. We carry out high-resolution simulations of the tidal evolution of our two-component Draco models in the potential of the Milky Way. The results of our simulations suggest that the observable properties of Draco have not been appreciably affected by the Galactic tides after 10 Gyr of evolution. We rule out Draco being a "tidal dwarf" - a tidally disrupted dwarf galaxy. Almost radial Draco orbits (with the pericentric distance <15 kpc) are also ruled out by our analysis. The case of a harmonic dark matter core can be consistent with observations only for a very limited choice of Draco orbits (with the apocentric-to-pericentric distances ratio of <2.5).Comment: 18 pages, 14 figures; accepted by Ap

Engineering Disease Resistance through Generation of an iPSC-derived P. Maniculatus Chimera

The goal of this project is to develop methods to manipulate the genome of Peromyscus maniculatus for the future eradication of diseases such as Hantavirus and Lyme disease that this species can transmit to humans. The initial thrust of this project is to generate induced pluripotent stem cells (iPSCs) from P. maniculatus mouse embryonic fibroblasts (MEFs) using an engineered Sendai Virus vector system. The Sendai Virus vector is a non-integrating viral vector that delivers four transcription factors necessary to reprogram normal somatic cells to a pluripotent, stem cell-like state. Subsequent, a plasmid will be used to insert DNA into the genome of the iPSC that codes for a fluorescent protein. In the future, the fluorescence will be used to confirm that Mus musculus cells are able to combine with the P. maniculatus cells in a chimeric blastocyst. Because many notable diseases are transmissible to humans from P. maniculatus, the genetic manipulation and creation of a disease resistant P. maniculatus using iPSCs could help to eradicate the spread of these diseases.

The origins of intensive marine fishing in medieval Europe: the English evidence

The catastrophic impact of fishing pressure on species such as cod and herring is well documented. However, the antiquity of their intensive exploitation has not been established. Systematic catch statistics are only available for ca. 100 years, but large-scale fishing industries existed in medieval Europe and the expansion of cod fishing from the fourteenth century (first in Iceland, then in Newfoundland) played an important role in the European colonization of the Northwest Atlantic. History has demonstrated the scale of these late medieval and post-medieval fisheries, but only archaeology can illuminate earlier practices. Zooarchaeological evidence shows that the clearest changes in marine fishing in England between AD 600 and 1600 occurred rapidly around AD 1000 and involved large increases in catches of herring and cod. Surprisingly, this revolution predated the documented post-medieval expansion of England's sea fisheries and coincided with the Medieval Warm Period-when natural herring and cod productivity was probably low in the North Sea. This counterintuitive discovery can be explained by the concurrent rise of urbanism and human impacts on freshwater ecosystems. The search for 'pristine' baselines regarding marine ecosystems will thus need to employ medieval palaeoecological proxies in addition to recent fisheries data and early modern historical records

Societal Institutions and Work and Family Gender-Role Attitudes

We examine associations between societal-level policies and gender-role attitudes using nationally representative International Social Survey Program (ISSP) data sets from 14 countries in 1994 and 2002. Hierarchical linear modeling (HLM) findings indicated that tax policies favoring dual-earner families were associated with greater egalitarianism in gender-role attitudes, while the relationship between parental leave times and individual gender-role attitudes was curvilinear in 2002. Low and high parental leave times were associated with traditionalism in gender-role attitude, while mid-length leaves were associated with egalitarianism. The findings support an institutional perspective on gender-role attitudes and suggest that public policies have sufficient impact on people’s interests and experiences to influence their gender-role views

Inhibition of NF-κB-mediated signaling by the cyclin-dependent kinase inhibitor CR8 overcomes pro-survival stimuli to induce apoptosis in chronic lymphocytic leukemia cells

Purpose: Chronic lymphocytic leukemia (CLL) is currently incurable with standard chemotherapeutic agents, highlighting the need for novel therapies. Overcoming proliferative and cytoprotective signals generated within the microenvironment of lymphoid organs is essential for limiting CLL progression and ultimately developing a cure. Experimental Design: We assessed the potency of cyclin-dependent kinase (CDK) inhibitor CR8, a roscovitine analog, to induce apoptosis in primary CLL from distinct prognostic subsets using flow cytometry–based assays. CLL cells were cultured in in vitro prosurvival and proproliferative conditions to mimic microenvironmental signals in the lymphoid organs, to elucidate the mechanism of action of CR8 in quiescent and proliferating CLL cells using flow cytometry, Western blotting, and quantitative real-time PCR. Results: CR8 was 100-fold more potent at inducing apoptosis in primary CLL cells than roscovitine, both in isolated culture and stromal-coculture conditions. Importantly, CR8 induced apoptosis in CD40-ligated CLL cells and preferentially targeted actively proliferating cells within these cultures. CR8 treatment induced downregulation of the antiapoptotic proteins Mcl-1 and XIAP, through inhibition of RNA polymerase II, and inhibition of NF-κB signaling at the transcriptional level and through inhibition of the inhibitor of IκB kinase (IKK) complex, resulting in stabilization of IκBα expression. Conclusions: CR8 is a potent CDK inhibitor that subverts pivotal prosurvival and proproliferative signals present in the tumor microenvironment of CLL patient lymphoid organs. Our data support the clinical development of selective CDK inhibitors as novel therapies for CLL

Tau Aggregation Inhibitor Therapy : An Exploratory Phase 2 Study in Mild or Moderate Alzheimer's Disease

ACKNOWLEDGMENTS We thank patients and their caregivers for their participation in the study and are indebted to all the investigators involved in the study, particularly Drs. Douglas Fowlie and Donald Mowat for their helpful contributions to the clinical execution of the study in Scotland. We thank Sharon Eastwood, Parexel, for assistance in preparing initial drafts of the manuscript. We acknowledge constructive comments provided by Professors G. Wilcock and S. Gauthier on drafts of the article. CMW, CRH, and JMDS are officers of, and hold beneficial interests in, TauRx Therapeutics. RTS, PB, KK, and DJW are paid consultants to TauRx Therapeutics. The study was financed entirely by TauRx TherapeuticsPeer reviewedPublisher PD