Packet-Level Diversity - From Theory to Practice: An 802.11-based Experimental Investigation

Packet-level diversity, or the ability to distribute packet transmissions over multiple, diverse channels, offers a number of benefits in improving communication performance and robustness to variations in channel quality. There have been a number of works that have analyzed and quantified those benefits, and developed transmission policies to realize them. However, translating those potential benefits into practice still faces numerous challenges. These range from uncertainty regarding the adequacy of the channel models on which the development of policies was predicated, to the many implementation constraints one faces when attempting to realize the precise transmission schedules that these policies mandate. This work is an initial step in assessing how much of the benefit that packet-level diversity promises actually remains once confronted with the many practical challenges we have just alluded to. Our investigation is carried out in the context of an 802.11 testbed, where diversity is realized through the different frequency bands available for transmissions between hosts and access points. We use our testbed to evaluate the impact of various parameters, including transmission policies, channel characteristics, channel correlation, and various end-system constraints that affect our ability to precisely control the timing of transmissions. Our investigation reveals that in spite of the many gaps that exist between theory and practice, packet-level diversity still provides a simple solution to improving transmission performance and robustness across a broad range of configurations

Improving habitats for wildlife in your backyard and neighborhood (2016)

A habitat for wildlife is as an area that provides their basic needs: food, cover or shelter, water, and space. Each habitat component is an important part of a wildlife-friendly yard. For example, providing supplemental foods for birds can create opportunities for closer observation. Building birdhouses provides nesting space to attract bluebirds, wrens, purple martins, chickadees and other species. Additionally, planting and managing for an appropriate mix of food and cover plants in proper locations can benefit wildlife, butterflies and other pollinator species. Planning ahead is crucial to developing a successful habitat. It is also helpful to understand some ecological concepts that provide the basis for implementing various management activities. This will help you identify specific habitat components that are in short supply for species of interest and address any deficiencies through active management. With proper planning, you can design habitats that suit your interests and preferences. By the same token, you can design a plan and manage habitats in your yard in such a way that prevents certain species that you consider to be a nuisance from becoming abundant.New 5/16/Web only

The Kinematics and Dynamics of the Globular Clusters and the Planetary Nebulae of NGC 5128

A new kinematic and dynamic study of the halo of the giant elliptical galaxy, NGC 5128, is presented. From a spectroscopically confirmed sample of 340 globular clusters and 780 planetary nebulae, the rotation amplitude, rotation axis, velocity dispersion, and the total dynamical mass are determined for the halo of NGC 5128. The globular cluster kinematics were searched for both radial dependence and metallicity dependence by subdividing the globular cluster sample into 158 metal-rich ([Fe/H] > -1.0) and 178 metal-poor ([Fe/H] < -1.0) globular clusters. Our results show the kinematics of the metal-rich and metal-poor subpopulations are quite similar. The kinematics are compared to the planetary nebula population where differences are apparent in the outer regions of the halo. The total mass of NGC 5128 is found using the Tracer Mass estimator (Evans et al. 2003), to determine the mass supported by internal random motions, and the spherical component of the Jeans equation to determine the mass supported by rotation. We find a total mass of (1.0+/-0.2) x 10^(12) Msun from the planetary nebulae data out to a projected radius of 90 kpc and (1.3+/-0.5) x 10^(12) Msun from the globular clusters out to a projected radius of 50 kpc. Lastly, we present a new and homogeneous catalog of known globular clusters in NGC 5128. This catalog combines all previous definitive cluster identifications from radial velocity studies and HST imaging studies, as well as 80 new globular clusters from a study of M.A. Beasley et al. (2007, in preparation).Comment: Accepted in the Astronomical Journal,52 pages, 13 figures, 6 tables - Changes made to Table 1 from originally submitted 0704.118

A 2dF spectroscopic study of globular clusters in NGC 5128: Probing the formation history of the nearest giant Elliptical

We have performed a spectroscopic study of globular clusters (GCs) in the giant elliptical NGC 5128 using the 2dF facility at the Anglo-Australian telescope. We obtained integrated optical spectra for a total of 254 GCs, 79 of which are newly confirmed on the basis of their radial velocities and spectra. In addition, we obtained an integrated spectrum of the galaxy starlight along the southern major axis. We derive an empirical metallicity distribution function (MDF) for 207 GCs (~14 of the estimated total GC system) based upon Milky Way GCs. This MDF is multimodal at high statistical significance with peaks at [Z/H]~-1.3 and -0.5. A comparison between the GC MDF and that of the stellar halo at 20 kpc (~4 Reff) reveals close coincidence at the metal-rich ends of the distributions. However, an inner 8 kpc stellar MDF shows a clear excess of metal-rich stars when compared to the GCs. We compare a higher S/N subsample (147 GCs) with two stellar population models which include non-solar abundance ratio corrections. The vast majority of our sample (~90%) appears old, with ages similar to the Milky Way GC system. There is evidence for a population of intermediate-age (~4-8 Gy) GCs (<15% of the sample) which are on average more metal-rich than the old GCs. We also identify at least one younger cluster (~1-2 Gy) in the central regions of the galaxy. Our observations are consistent with a picture where NGC 5128 has undergone at least two mergers and/or interactions involving star formation and limited GC formation since z=1, however the effect of non-canonical hot stellar populations on the integrated spectra of GCs remains an outstanding uncertainty in our GC age estimates.Comment: 17 figures, some long table

Transcriptome analyses of the human retina identify unprecedented transcript diversity and 3.5 Mb of novel transcribed sequence via significant alternative splicing and novel genes

Background: The retina is a complex tissue comprised of multiple cell types that is affected by a diverse set of diseases that are important causes of vision loss. Characterizing the transcripts, both annotated and novel, that are expressed in a given tissue has become vital for understanding the mechanisms underlying the pathology of disease. Results: We sequenced RNA prepared from three normal human retinas and characterized the retinal transcriptome at an unprecedented level due to the increased depth of sampling provided by the RNA-seq approach. We used a non-redundant reference transcriptome from all of the empirically-determined human reference tracks to identify annotated and novel sequences expressed in the retina. We detected 79,915 novel alternative splicing events, including 29,887 novel exons, 21,757 3′ and 5′ alternate splice sites, and 28,271 exon skipping events. We also identified 116 potential novel genes. These data represent a significant addition to the annotated human transcriptome. For example, the novel exons detected increase the number of identified exons by 3%. Using a high-throughput RNA capture approach to validate 14,696 of these novel transcriptome features we found that 99% of the putative novel events can be reproducibly detected. Further, 15-36% of the novel splicing events maintain an open reading frame, suggesting they produce novel protein products. Conclusions: To our knowledge, this is the first application of RNA capture to perform large-scale validation of novel transcriptome features. In total, these analyses provide extensive detail about a previously uncharacterized level of transcript diversity in the human retina

Cyberinfrastructure, Science Gateways, Campus Bridging, and Cloud Computing

Computers accelerate our ability to achieve scientific breakthroughs. As technology evolves and new research needs come to light, the role for cyberinfrastructure as “knowledge” infrastructure continues to expand. This article defines and discusses cyberinfrastructure and the related topics of science gateways and campus bridging; identifies future challenges in cyberinfrastructure; and discusses challenges and opportunities related to the evolution of cyberinfrastructure, “big data” (datacentric, data-enabled, and data-intensive research and data analytics), and cloud computing.This material is based upon work supported by the National Science Foundation under grants 0504075, 0451237, 0723054, 1062432, 0116050, 0521433, 0503697, and 1053575, and several IBM Shared University Research grants and support provided by Lilly Endowment, Inc. for the Indiana University Pervasive Technology Institute. Any opinions, findings and conclusions or recommendations expressed herein are those of the authors and do not necessarily reflect the views of the supporting agencies

Transcriptome analyses of the human retina identify unprecedented transcript diversity and 3.5 Mb of novel transcribed sequence via significant alternative splicing and novel genes

Background: The retina is a complex tissue comprised of multiple cell types that is affected by a diverse set of diseases that are important causes of vision loss. Characterizing the transcripts, both annotated and novel, that are expressed in a given tissue has become vital for understanding the mechanisms underlying the pathology of disease. Results: We sequenced RNA prepared from three normal human retinas and characterized the retinal transcriptome at an unprecedented level due to the increased depth of sampling provided by the RNA-seq approach. We used a non-redundant reference transcriptome from all of the empirically-determined human reference tracks to identify annotated and novel sequences expressed in the retina. We detected 79,915 novel alternative splicing events, including 29,887 novel exons, 21,757 3′ and 5′ alternate splice sites, and 28,271 exon skipping events. We also identified 116 potential novel genes. These data represent a significant addition to the annotated human transcriptome. For example, the novel exons detected increase the number of identified exons by 3%. Using a high-throughput RNA capture approach to validate 14,696 of these novel transcriptome features we found that 99% of the putative novel events can be reproducibly detected. Further, 15-36% of the novel splicing events maintain an open reading frame, suggesting they produce novel protein products. Conclusions: To our knowledge, this is the first application of RNA capture to perform large-scale validation of novel transcriptome features. In total, these analyses provide extensive detail about a previously uncharacterized level of transcript diversity in the human retina

Fire and Ice in Central Idaho: Modern and Holocene Fires, Debris Flows, and Climate in the Payette River Basin, and Quaternary and Glacial Geology in the Sawtooth Mountains

This 2-day trip will highlight recent fire and storm-related debris flows in the Payette River region, Holocene records of fires and fire-related sedimentation events preserved in alluvial fan stratigraphic sequences, and geomorphology and geology of alpine glaciations in the spectacular Sawtooth Mountains and Stanley Basin of central Idaho. Storm events and associated scour following recent fires in the South Fork Payette basin have exposed Holocene fire-related debris-flow deposits, flood sediments, and other alluvial fan-building deposits that yield insights into Holocene environmental change. Moraine characteristics and sediment cores from the southeastern Sawtooth Mountains and Stanley Basin provide evidence of late Pleistocene alpine glaciation. A combination of these glacial records with reconstructions of regional equilibrium line elevations produces late-glacial paleoclimatic inferences for the area. Day one of the trip will examine recent and Holocene fire-related deposits along the South Fork Payette River; day two will focus on alpine glaciation in the Sawtooth Mountains (fig. 1). A description of the scope, methods, results and interpretation of the South Fork Payette fire study is given below. Background information on late Pleistocene alpine glaciation in the eastern Sawtooth Mountains is presented with the material for day 2 of the trip. The road log for day 1 of the trip begins at Banks, Idaho, and ends in Stanley, Idaho. Stop locations are shown on figure 2. At Stop 1, we will provide an introduction to interpretation of alluvial fan stratigraphic sections, and discuss the Boise Ridge fault. At Stops 2–4 (Hopkins Creek, Deadwood River, and Jughead creek), we will examine recent debrisflow deposits and Holocene alluvial fan stratigraphic sections. At Stop 5 (Helende Campground), we will look at a series of well-preserved Holocene and Pleistocene terraces and at Stop 6 (Canyon Creek), we will briefly inspect fire-related deposits in higher-elevation alluvial fan stratigraphic sections. The road log for day 2 begins at Stanley, Idaho, and ends in Sun Valley, Idaho. Stop locations are shown on figure 2. Stop 1, at Redfish Lake, will focus on regional equilibrium line altitude reconstructions and on the general pattern of late Pleistocene glaciation on the eastern flank of the Sawtooth Mountains. Stop 2 will be at Pettit Lake, where we will examine the moraine sequence and discuss relative weathering criteria and moraine groupings. At Stop 3, near Alturas Lake, we will discuss lake sediment coring, moraine chronology, and implications for latest Pleistocene paleoclimatic inferences. Stop 4 will be a brief stop at Galena Summit for an overview of the Sawtooth Mountains and a discussion of ice accumulation patterns. The trip will end at a set of moraines in the Trail Creek valley, near Sun Valley, where we will examine moraine morphology and weathering rind data that constrain the moraine ages

C16-Ceramide Analog Combined with Pc 4 Photodynamic Therapy Evokes Enhanced Total Ceramide Accumulation, Promotion of DEVDase Activation in the Absence of Apoptosis, and Augmented Overall Cell Killing

Because of the failure of single modality approaches, combination therapy for cancer treatment is a promising alternative. Sphingolipid analogs, with or without anticancer drugs, can improve tumor response. C16-pyridinium ceramide analog LCL30, was used in combination with photodynamic therapy (PDT), an anticancer treatment modality, to test the hypothesis that the combined treatment will trigger changes in the sphingolipid profile and promote cell death. Using SCCVII mouse squamous carcinoma cells, and the silicone phthalocyanine Pc 4 for PDT, we showed that combining PDT with LCL30 (PDT/LCL30) was more effective than individual treatments in raising global ceramide levels, as well as in reducing dihydrosphingosine levels. Unlike LCL30, PDT, alone or combined, increased total dihydroceramide levels. Sphingosine levels were unaffected by LCL30, but were abolished after PDT or the combination. LCL30-triggered rise in sphingosine-1-phosphate was reversed post-PDT or the combination. DEVDase activation was evoked after PDT or LCL30, and was promoted post- PDT/LCL30. Neither mitochondrial depolarization nor apoptosis were observed after any of the treatments. Notably, treatment with the combination resulted in augmented overall cell killing. Our data demonstrate that treatment with PDT/LCL30 leads to enhanced global ceramide levels and DEVDase activation in the absence of apoptosis, and promotion of total cell killing

Observations and numerical simulations of large-eddy circulation in the ocean surface mixed layer

Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 41 (2014): 7584–7590, doi:10.1002/2014GL061637.Two near-surface dye releases were mapped on scales of minutes to hours temporally, meters to order 1 km horizontally, and 1–20 m vertically using a scanning, depth-resolving airborne lidar. In both cases, dye evolved into a series of rolls with their major axes approximately aligned with the wind and/or near-surface current. In both cases, roll spacing was also of order 5–10 times the mixed layer depth, considerably larger than the 1–2 aspect ratio expected for Langmuir cells. Numerical large-eddy simulations under similar forcing showed similar features, even without Stokes drift forcing. In one case, inertial shear driven by light winds induced large aspect ratio large-eddy circulation. In the second, a preexisting lateral mixed layer density gradient provided the dominant forcing. In both cases, the growth of the large-eddy structures and the strength of the resulting dispersion were highly dependent on the type of forcing.Support for the 2004 field experiment was provided by the Cecil H. and Ida M. Green Technology Innovation Fund and Coastal Ocean Institute grant 27001545, both through Woods Hole Oceanographic Institution, and by Office of Naval Research grant N00014-01-1-0984. Support for the 2011 field experiments was provided by ONR grants N00014-09-1-0194, N00014-09-1-0175, N00014-11-WX-21010, N00014-12-WX-21031, and N00014-09-1-0460 and NSF grants OCE-0751734 and OCE-0751653. Simulations were supported under grant N00014-09-1-0268.2015-05-0