Precision overhead irrigation is suitable for several Central Valley crops

Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotton, tomato, onion and broccoli as an alternative to furrow and drip irrigation. With the exception of tomato, equal or increased yields were achieved with overhead irrigation. Many variables are involved in the choice of an irrigation system, but our results suggest that, with more research to support best management practices, overhead irrigation may be useful to a wider set of California farmers than currently use it

Galaxy subgroups in galaxy clusters

Galaxies which fall into clusters as part of the same infall halo can retain correlations due to their shared origin. N-body simulations are used to study properties of such galaxy subgroups within clusters, including their richnesses and prevalence. The sizes, densities and velocity dispersions of all subgroups with >= 8 galaxies are found and compared to those of the host clusters. The largest galaxy subgroup provides a preferred direction in the cluster and is compared to other preferred directions in the cluster. Scatter in cluster mass measurements (via five observables), along ~ 96 lines of sight, is compared to the relation of the line of sight to this preferred direction: scatter in cluster velocity dispersion measurements show the strongest correlation. The Dressler-Shectman test (Dressler & Shectman 1988), is applied to these clusters, to see whether the substructure it identifies is related to these subgroups. The results for any specific line of sight seem noisy; however, clusters with large subgroups tend to have a higher fraction of lines of sight where the test detects substructure.Comment: 12 pages, final version for publication with helpful comments from referee and others include

Disentangling correlated scatter in cluster mass measurements

The challenge of obtaining galaxy cluster masses is increasingly being addressed by multiwavelength measurements. As scatters in measured cluster masses are often sourced by properties of or around the clusters themselves, correlations between mass scatters are frequent and can be significant, with consequences for errors on mass estimates obtained both directly and via stacking. Using a high resolution 250 Mpc/h side N-body simulation, combined with proxies for observational cluster mass measurements, we obtain mass scatter correlations and covariances for 243 individual clusters along ~96 lines of sight each, both separately and together. Many of these scatters are quite large and highly correlated. We use principal component analysis (PCA) to characterize scatter trends and variations between clusters. PCA identifies combinations of scatters, or variations more generally, which are uncorrelated or non-covariant. The PCA combination of mass measurement techniques which dominates the mass scatter is similar for many clusters, and this combination is often present in a large amount when viewing the cluster along its long axis. We also correlate cluster mass scatter, environmental and intrinsic properties, and use PCA to find shared trends between these. For example, if the average measured richness, velocity dispersion and Compton decrement mass for a cluster along many lines of sight are high relative to its true mass, in our simulation the cluster's mass measurement scatters around this average are also high, its sphericity is high, and its triaxiality is low. Our analysis is based upon estimated mass distributions for fixed true mass. Extensions to observational data would require further calibration from numerical simulations, tuned to specific observational survey selection functions and systematics.Comment: 18 pages, 12 figures, final version to appear in MNRAS, helpful changes from referee and others incorporate

Coastal shoreline change assessments at global scales

During the present era of rapid climate change and sea-level rise, coastal change science is needed at global, regional, and local scales. Essential elements of this science, regardless of scale, include that the methods are defendable and that the results are independently verifiable. The recent contribution by Almar et al.1 does not achieve either of these measures as shown by: (i) the use of an error-prone proxy for coastal shoreline and (ii) analyses that are circular and explain little of the data variance

Molecular mechanism of dynein recruitment to kinetochores by the Rod-Zw10-Zwilch complex and Spindly

The molecular motor dynein concentrates at the kinetochore region of mitotic chromosomes in animals to accelerate spindle microtubule capture and to control spindle checkpoint signaling. In this study, we describe the molecular mechanism used by the Rod-Zw10-Zwilch complex and the adaptor Spindly to recruit dynein to kinetochores in Caenorhabditis elegans embryos and human cells. We show that Rod's N-terminal beta-propeller and the associated Zwilch subunit bind Spindly's C-terminal domain, and we identify a specific Zwilch mutant that abrogates Spindly and dynein recruitment in vivo and Spindly binding to a Rod beta-propeller-Zwilch complex in vitro. Spindly's N-terminal coiled-coil uses distinct motifs to bind dynein light intermediate chain and the pointed-end complex of dynactin. Mutations in these motifs inhibit assembly of a dynein-dynactin-Spindly complex, and a null mutant of the dynactin pointed-end subunit p27 prevents kinetochore recruitment of dynein-dynactin without affecting other mitotic functions of the motor. Conservation of Spindly-like motifs in adaptors involved in intracellular transport suggests a common mechanism for linking dynein to cargo.This work was supported by a European Research Council Starting Grant (Dyneinome 338410) and a European Molecular Biology Organization Installation Grant to R. Gassmann. This work was also supported by funding from the Fundacao para a Ciencia e a Tecnologia to R. Gassmann (IF/01015/2013/CP1157/CT0006), C. Pereira (SFRH_BPD_95648_2013), and D.J. Barbosa (SFRH_BPD_101898_2014). Some C. elegans strains were provided by the Caenorhabditis Genetics Center, which is funded by the National Institutes of Health Office of Research Infrastructure Programs (P40 OD010440)

Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci

Background: A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs). Results: We demonstrate that all CTs are composed of structurally linked chromatin domain clusters (CDCs). In active CTs the periphery of CDCs harbors low-density chromatin enriched with transcriptionally competent markers, called the perichromatin region (PR). The PR borders on a contiguous channel system, the interchromatin compartment (IC), which starts at nuclear pores and pervades CTs. We propose that the PR and macromolecular complexes in IC channels together form the transcriptionally permissive active nuclear compartment (ANC). The Barr body differs from active CTs by a partially collapsed ANC with CDCs coming significantly closer together, although a rudimentary IC channel system connected to nuclear pores is maintained. Distinct Xist RNA foci, closely adjacent to the nuclear matrix scaffold attachment factor-A (SAF-A) localize throughout Xi along the rudimentary ANC. In early differentiating ESCs initial Xist RNA spreading precedes Barr body formation, which occurs concurrent with the subsequent exclusion of RNA polymerase II (RNAP II). Induction of a transgenic autosomal Xist RNA in a male ESC triggers the formation of an `autosomal Barr body' with less compacted chromatin and incomplete RNAP II exclusion. Conclusions: 3D-SIM provides experimental evidence for profound differences between the functional architecture of transcriptionally active CTs and the Barr body. Basic structural features of CT organization such as CDCs and IC channels are however still recognized, arguing against a uniform compaction of the Barr body at the nucleosome level. The localization of distinct Xist RNA foci at boundaries of the rudimentary ANC may be considered as snap-shots of a dynamic interaction with silenced genes. Enrichment of SAF-A within Xi territories and its close spatial association with Xist RNA suggests their cooperative function for structural organization of Xi

Analysis of the Phlebiopsis gigantea Genome, Transcriptome and Secretome Provides Insight into Its Pioneer Colonization Strategies of Wood

Peer reviewe

Geomorphology and stream habitat relationships with smallmouth bass abundance at multiple spatial scales in eastern Oklahoma

Fluvial geomorphic processes structure habitats important to stream fishes. We determined relationships between densities of smallmouth bass (Micropterus dolomieu) and ecoregions, watershed and reach morphology, and stream habitat in eastern Oklahoma, USA. Watershed and reach morphology were measured at 128 stream sites, and stream habitat and smallmouth bass abundance were measured in 1800 channel units. Variation in stream size, channel morphology, and substrate size constituted major physical differences among sites. Channel morphology differed among ecoregions in the largest streams. Densities of age-0 and age-1 and older smallmouth bass were approximately an order of magnitude greater in the Boston Mountains and Ozark Highlands streams than in Ouachita Mountains streams. Regression tree analysis explained less variation in age-0 (10-fold cross-validated relative error = 0.843) than in age-1 and older (relative error = 0.650) smallmouth bass densities and showed that stream size and channel-unit size were primary determinants of density. Channel morphology explained variation in densities in deep channel units of large streams, which was somewhat independent of ecoregion

Cdc42 and the Actin-Related Protein/Neural Wiskott-Aldrich Syndrome Protein Network Mediate Cellular Invasion by Cryptosporidium parvum

Cryptosporidium parvum invasion of epithelial cells involves host cell membrane alterations which require a remodeling of the host cell actin cytoskeleton. In addition, an actin plaque, possibly associated with the dense-band region, forms within the host cytoplasm at the host-parasite interface. Here we show that Cdc42 and RhoA, but not Rac1, members of the Rho family of GTPases, are recruited to the host-parasite interface in an in vitro model of human biliary cryptosporidiosis. Interestingly, activation of Cdc42, but not RhoA, was detected in the infected cells. Neural Wiskott-Aldrich syndrome protein (N-WASP) and p34-Arc, actin-regulating downstream effectors of Cdc42, were also recruited to the host-parasite interface. Whereas cellular expression of a constitutively active mutant of Cdc42 promoted C. parvum invasion, overexpression of a dominant negative mutant of Cdc42, or depletion of Cdc42 mRNA by short interfering RNA-mediated gene silencing, inhibited C. parvum invasion. Expression of the WA fragment of N-WASP to block associated actin polymerization also inhibited C. parvum invasion. Moreover, inhibition of host cell Cdc42 activation by dominant negative mutation inhibited C. parvum-associated actin remodeling, membrane protrusion, and dense-band formation. In contrast, treatment of cells with a Rho inhibitor, exoenzyme C3, or cellular overexpression of dominant negative mutants of RhoA and Rac1 had no effect on C. parvum invasion. These data suggest that C. parvum invasion of target epithelia results from the organism's ability to activate a host cell Cdc42 GTPase signaling pathway to induce host cell actin remodeling at the attachment site