Community Impacts of Prosopis Juliflora Invasion: Biogeographic and Congeneric Comparisons

We coordinated biogeographical comparisons of the impacts of an exotic invasive tree in its native and non-native ranges with a congeneric comparison in the non-native range. Prosopis juliflora is taxonomically complicated and with P. pallida forms the P. juliflora complex. Thus we sampled P. juliflora in its native Venezuela, and also located two field sites in Peru, the native range of Prosopis pallida. Canopies of Prosopis juliflora, a native of the New World but an invader in many other regions, had facilitative effects on the diversity of other species in its native Venezuela, and P. pallida had both negative and positive effects depending on the year, (overall neutral effects) in its native Peru. However, in India and Hawaii, USA, where P. juliflora is an aggressive invader, canopy effects were consistently and strongly negative on species richness. Prosopis cineraria, a native to India, had much weaker effects on species richness in India than P. juliflora. We carried out multiple congeneric comparisons between P. juliflora and P. cineraria, and found that soil from the rhizosphere of P. juliflora had higher extractable phosphorus, soluble salts and total phenolics than P. cineraria rhizosphere soils. Experimentally applied P. juliflora litter caused far greater mortality of native Indian species than litter from P. cineraria. Prosopis juliflora leaf leachate had neutral to negative effects on root growth of three common crop species of north-west India whereas P. cineraria leaf leachate had positive effects. Prosopis juliflora leaf leachate also had higher concentrations of total phenolics and L-tryptophan than P. cineraria, suggesting a potential allelopathic mechanism for the congeneric differences. Our results also suggest the possibility of regional evolutionary trajectories among competitors and that recent mixing of species from different trajectories has the potential to disrupt evolved interactions among native species

Evolution of a Canada Basin ice-ocean boundary layer and mixed layer across a developing thermodynamically forced marginal ice zone

A comprehensive set of autonomous, ice-ocean measurements were collected across the Canada Basin to study the summer evolution of the ice-ocean boundary layer (IOBL) and ocean mixed layer (OML). Evaluation of local heat and freshwater balances and associated turbulent forcing reveals that melt ponds (MPs) strongly influence the summer IOBL-OML evolution. Areal expansion of MPs in mid-June start the upper ocean evolution resulting in significant increases to ocean absorbed radiative flux (19 W m−2 in this study). Buoyancy provided by MP drainage shoals and freshens the IOBL resulting in a 39 MJ m−2 increase in heat storage in just 19 days (52% of the summer total). Following MP drainage, a near-surface fresh layer deepens through shear-forced mixing to form the summer mixed layer (sML). In late summer, basal melt increases due to stronger turbulent mixing in the thin sML and the expansion of open water areas due in part to wind-forced divergence of the sea ice. Thermal heterogeneities in the marginal ice zone (MIZ) upper ocean led to large ocean-to-ice heat fluxes (100–200 W m−2) and enhanced basal ice melt (3–6 cm d−1), well away from the ice edge. Calculation of the upper ocean heat budget shows that local radiative heat input accounted for at least 89% of the observed latent heat losses and heat storage (partitioned 0.77/0.23). These results suggest that the extensive area of deteriorating sea ice observed away from the ice edge during the 2014 season, termed the “thermodynamically forced MIZ,” was driven primarily by local shortwave radiative forcing

A bi‐organellar phylogenomic study of Pandanales: inference of higher‐order relationships and unusual rate‐variation patterns

We used a bi‐organellar phylogenomic approach to address higher‐order relationships in Pandanales, including the first molecular phylogenetic study of the panama‐hat family, Cyclanthaceae. Our genus‐level study of plastid and mitochondrial gene sets includes a comprehensive sampling of photosynthetic lineages across the order, and provides a framework for investigating clade ages, biogeographic hypotheses and organellar molecular evolution. Using multiple inference methods and both organellar genomes, we recovered mostly congruent and strongly supported relationships within and between families, including the placement of fully mycoheterotrophic Triuridaceae. Cyclanthaceae and Pandanaceae plastomes have slow substitution rates, contributing to weakly supported plastid‐based relationships in Cyclanthaceae. While generally slowly evolving, mitochondrial genomes exhibit sporadic rate elevation across the order. However, we infer well‐supported relationships even for slower evolving mitochondrial lineages in Cyclanthaceae. Clade age estimates across photosynthetic lineages are largely consistent with previous studies, are well correlated between the two organellar genomes (with slightly younger inferences from mitochondrial data), and support several biogeographic hypotheses. We show that rapidly evolving non‐photosynthetic lineages may bias age estimates upwards at neighbouring photosynthetic nodes, even using a relaxed clock model. Finally, we uncovered new genome structural variants in photosynthetic taxa at plastid inverted repeat boundaries that show promise as interfamilial phylogenetic markers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/33/cla12417-sup-0025-TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/32/cla12417-sup-0017-FigS17.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/31/cla12417-sup-0004-FigS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/30/cla12417-sup-0019-FigS19.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/29/cla12417-sup-0020-FigS20.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/28/cla12417_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/27/cla12417-sup-0005-FigS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/26/cla12417-sup-0012-FigS12.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/25/cla12417-sup-0007-FigS7.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/24/cla12417-sup-0022-FigS22.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/23/cla12417-sup-0029-TableS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/22/cla12417-sup-0010-FigS10.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/21/cla12417-sup-0011-FigS11.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/20/cla12417-sup-0014-FigS14.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/19/cla12417-sup-0002-FigS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/18/cla12417-sup-0001-FigS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/17/cla12417.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/16/cla12417-sup-0030-TableS6.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/15/cla12417-sup-0021-FigS21.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/14/cla12417-sup-0023-FigS23.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/13/cla12417-sup-0009-FigS9.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/12/cla12417-sup-0031-TableS7.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/11/cla12417-sup-0006-FigS6.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/10/cla12417-sup-0003-FigS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/9/cla12417-sup-0024-FigS24.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/8/cla12417-sup-0008-FigS8.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/7/cla12417-sup-0028-TableS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/6/cla12417-sup-0016-FigS16.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/5/cla12417-sup-0013-FigS13.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/4/cla12417-sup-0018-FigS18.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/3/cla12417-sup-0026-TableS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/2/cla12417-sup-0015-FigS15.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162810/1/cla12417-sup-0027-TableS3.pd

Ice and ocean velocity in the Arctic marginal ice zone: Ice roughness and momentum transfer

The interplay between sea ice concentration, sea ice roughness, ocean stratification, and momentum transfer to the ice and ocean is subject to seasonal and decadal variations that are crucial to understanding the present and future air-ice-ocean system in the Arctic. In this study, continuous observations in the Canada Basin from March through December 2014 were used to investigate spatial differences and temporal changes in under-ice roughness and momentum transfer as the ice cover evolved seasonally. Observations of wind, ice, and ocean properties from four clusters of drifting instrument systems were complemented by direct drill-hole measurements and instrumented overhead flights by NASA operation IceBridge in March, as well as satellite remote sensing imagery about the instrument clusters. Spatially, directly estimated ice-ocean drag coefficients varied by a factor of three with rougher ice associated with smaller multi-year ice floe sizes embedded within the first-year-ice/multi-year-ice conglomerate. Temporal differences in the ice-ocean drag coefficient of 20–30% were observed prior to the mixed layer shoaling in summer and were associated with ice concentrations falling below 100%. The ice-ocean drag coefficient parameterization was found to be invalid in September with low ice concentrations and small ice floe sizes. Maximum momentum transfer to the ice occurred for moderate ice concentrations, and transfer to the ocean for the lowest ice concentrations and shallowest stratification. Wind work and ocean work on the ice were the dominant terms in the kinetic energy budget of the ice throughout the melt season, consistent with free drift conditions. Overall, ice topography, ice concentration, and the shallow summer mixed layer all influenced mixed layer currents and the transfer of momentum within the air-ice-ocean system. The observed changes in momentum transfer show that care must be taken to determine appropriate parameterizations of momentum transfer, and imply that the future Arctic system could become increasingly seasonal

hHSS1: a novel secreted factor and suppressor of glioma growth located at chromosome 19q13.33

The completion of the Human Genome Project resulted in discovery of many unknown novel genes. This feat paved the way for the future development of novel therapeutics for the treatment of human disease based on novel biological functions and pathways. Towards this aim, we undertook a bioinformatics analysis of in-house microarray data derived from purified hematopoietic stem cell populations. This effort led to the discovery of HSS1 (Hematopoietic Signal peptide-containing Secreted 1) and its splice variant HSM1 (Hematopoietic Signal peptide-containing Membrane domain-containing 1). HSS1 gene is evolutionarily conserved across species, phyla and even kingdoms, including mammals, invertebrates and plants. Structural analysis showed no homology between HSS1 and known proteins or known protein domains, indicating that it was a truly novel protein. Interestingly, the human HSS1 (hHSS1) gene is located at chromosome 19q13.33, a genomic region implicated in various cancers, including malignant glioma. Stable expression of hHSS1 in glioma-derived A172 and U87 cell lines greatly reduced their proliferation rates compared to mock-transfected cells. hHSS1 expression significantly affected the malignant phenotype of U87 cells both in vitro and in vivo. Further, preliminary immunohistochemical analysis revealed an increase in hHSS1/HSM1 immunoreactivity in two out of four high-grade astrocytomas (glioblastoma multiforme, WHO IV) as compared to low expression in all four low-grade diffuse astrocytomas (WHO grade II). High-expression of hHSS1 in high-grade gliomas was further supported by microarray data, which indicated that mesenchymal subclass gliomas exclusively up-regulated hHSS1. Our data reveal that HSS1 is a truly novel protein defining a new class of secreted factors, and that it may have an important role in cancer, particularly glioma

Multilineage hematopoietic recovery with concomitant antitumor effects using low dose Interleukin-12 in myelosuppressed tumor-bearing mice

<p>Abstract</p> <p>Background</p> <p>Interleukin-12 (IL-12) is a cytokine well known for its role in immunity. A lesser known function of IL-12 is its role in hematopoiesis. The promising data obtained in the preclinical models of antitumor immunotherapy raised hope that IL-12 could be a powerful therapeutic agent against cancer. However, excessive clinical toxicity, largely due to repeat dose regimens, and modest clinical response observed in the clinical trials have pointed to the necessity to design protocols that minimize toxicity without affecting the anti-tumor effect of IL-12. We have focused on the lesser known role of IL-12 in hematopoiesis and hypothesized that an important clinical role for IL-12 in cancer may be as an adjuvant hematological cancer therapy. In this putative clinical function, IL-12 is utilized for the prevention of cancer therapy-related cytopenias, while providing concomitant anti-tumor responses over and above responses observed with the primary therapy alone. This putative clinical function of IL-12 focuses on the dual role of IL-12 in hematopoiesis and immunity.</p> <p>Methods</p> <p>We assessed the ability of IL-12 to facilitate hematopoietic recovery from radiation (625 rad) and chemotherapy (cyclophosphamide) in two tumor-bearing murine models, namely the EL4 lymphoma and the Lewis lung cancer models. Antitumor effects and changes in bone marrow cellularity were also assessed.</p> <p>Results</p> <p>We show herein that carefully designed protocols, in mice, utilizing IL-12 as an adjuvant to radiation or chemotherapy yield facile and consistent, multilineage hematopoietic recovery from cancer therapy-induced cytopenias, as compared to vehicle and the clinically-utilized cytokine granulocyte colony-stimulating factor (G-CSF) (positive control), while still providing concomitant antitumor responses over and above the effects of the primary therapy alone. Moreover, our protocol design utilizes single, low doses of IL-12 that did not yield any apparent toxicity.</p> <p>Conclusion</p> <p>Our results portend that despite its past failure, IL-12 appears to have significant clinical potential as a hematological adjuvant cancer therapy.</p

HemaMax™, a Recombinant Human Interleukin-12, Is a Potent Mitigator of Acute Radiation Injury in Mice and Non-Human Primates

HemaMax, a recombinant human interleukin-12 (IL-12), is under development to address an unmet medical need for effective treatments against acute radiation syndrome due to radiological terrorism or accident when administered at least 24 hours after radiation exposure. This study investigated pharmacokinetics, pharmacodynamics, and efficacy of m-HemaMax (recombinant murine IL-12), and HemaMax to increase survival after total body irradiation (TBI) in mice and rhesus monkeys, respectively, with no supportive care. In mice, m-HemaMax at an optimal 20 ng/mouse dose significantly increased percent survival and survival time when administered 24 hours after TBI between 8–9 Gy (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by increases in plasma interferon-γ (IFN-γ) and erythropoietin levels, recovery of femoral bone hematopoiesis characterized with the presence of IL-12 receptor β2 subunit–expressing myeloid progenitors, megakaryocytes, and osteoblasts. Mitigation of jejunal radiation damage was also examined. At allometrically equivalent doses, HemaMax showed similar pharmacokinetics in rhesus monkeys compared to m-HemaMax in mice, but more robustly increased plasma IFN-γ levels. HemaMax also increased plasma erythropoietin, IL-15, IL-18, and neopterin levels. At non-human primate doses pharmacologically equivalent to murine doses, HemaMax (100 ng/Kg and 250 ng/Kg) administered at 24 hours after TBI (6.7 Gy/LD50/30) significantly increased percent survival of HemaMax groups compared to vehicle (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by a significantly higher leukocyte (neutrophils and lymphocytes), thrombocyte, and reticulocyte counts during nadir (days 12–14) and significantly less weight loss at day 12 compared to vehicle. These findings indicate successful interspecies dose conversion and provide proof of concept that HemaMax increases survival in irradiated rhesus monkeys by promoting hematopoiesis and recovery of immune functions and possibly gastrointestinal functions, likely through a network of interactions involving dendritic cells, osteoblasts, and soluble factors such as IL-12, IFN-γ, and cytoprotectant erythropoietin

Optimization of energy transfer in a polymer composite with perylene chromophores

Luminescent solar concentrators based on molecular dyes are a promising approach to light collection for photovoltaics owing to their potential low cost and wide light acceptance angles. However, they readily suffer from self-absorption, which rapidly reduces device efficiency. We use a perylene-based sensitizer–emitter system to reduce self-absorption. The sensitizer and emitter are copolymerized to enhance energy transfer to the emitter. The sensitizer is susceptible to yield-reducing H-aggregation. We show that a composite polymer can be used to reduce H-aggregation, while maintaining efficient energy transfer