1,043 research outputs found

    Propagation of Bamboo as Blackbird Lure Roost Habitat

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    Bamboo and native cane species have been suggested as optimal lure roost habitat for shifting blackbird winter roosts away from objectionable urban/suburban sites. As the second phase in developing this potential concept of alleviating conflicts with blackbirds, we report on information gathered from the literature, consultations with bamboo horticulturists, and on-site visits to previously developed bamboo plantations to select desirable species of bamboo for this purpose, and to identify preferred propagating techniques. Bamboo species Phyllostachys rubromarginata and P. nigra henonis ranked highest in terms of greatest cold tolerance, greatest propensity for lateral spreading, and most suitable structure characteristics for maximizing blackbird roosting population densities. The planting of selected rhizome cuttings at 5 X 5 m (16 X 16 ft.) spacing in the early spring was found to be the most practical method of successfully developing desirable roosting habitat in 3-4 years. Other considerations in propagating and managing bamboo as blackbird roosting habitat are discussed

    Temporal Use Patterns of Wintering Starlings at a Southeastern Livestock Farm: Implications for Damage Control

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    The farm use patterns of individually marked and transmitter-equipped starlings at a livestock farm in south-central Kentucky were studied each month during the principal damage period (December-February) of 1982-83 and 1984-85 following a pilot study in January and February of 1980. In addition to intensive observation at the farm, sightings of tagged starlings away from the farm were solicited from the public and mapped. For each year of data on individual starlings that used the farm at least once after marking, the expected frequencies of farm occurrence were calculated and compared to observed frequencies. In all 3 years, there was a significant (P \u3c 0.01) heterogeneity among birds in their frequency of farm use. The observed frequencies of daily farm use appeared bimodal suggesting starling subpopulations of frequent versus infrequent farm users. The preponderance of individuals occurred at the farm infrequently. Analysis of starling foraging patterns indicated that frequent farm visitors were also likely to use livestock feed sites more often than infrequent visitors. In 1984-85 the monthly starling turnover at the farm was calculated at 70.3% from December to January and 67.4% from January to February. Data on marked starling sightings away from the farm indicated that these individuals only moved a median distance of only 2.7 km from the farm suggesting a strong fidelity to their foraging area near the farm. The management implications of these data are discussed relative to integrated strategies of starling damage reduction at livestock farms in the southeastern United States

    Controlling Great-Tailed Grackle Damage to Citrus in the Lower Rio Grande Valley, Texas

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    Great-tailed grackle (Quiscalus mexicanus) damage to citrus is a serious concern to producers in the lower Rio Grande Valley of Texas. Damage caused by grackles pecking fruit is initiated by breeding colonies in the spring on immature fruit and extends through the fall and winter on ripening fruit. The most significant damage occurs during the post-breeding period of July through September when neither the currently registered DRC-1339-treated dog food bait nor frightening strategies are effective. Observations by Texas Wildlife Services personnel suggested that watermelon was highly attractive to grackles during the period when dog food baits are poorly accepted. Two control strategies using watermelon to bait large cage traps and to formulate DRC-1339 baits were evaluated in cage and field trials during a 2-year research project. This paper reports on the development and preliminary evaluations of a unique trap design and the 0.1% DRC-1339-treated watermelon bait. Summer field trials in citrus groves were conducted to evaluate the effectiveness and safety of trapping and DRC-1339 baiting. Results of preliminary evaluations clearly demonstrated the utility of these methods for controlling grackles. Although the effectiveness of these methods for controlling grackle damage in citrus groves was less conclusive, no measurable hazards to non-target wildlife were documented. With suggested modifications, both methods may provide a viable means to reduce grackle damage to citrus during a period when other alternative methods are ineffective

    Iron bioavailability in two commercial cultivars of wheat: a comparison between wholegrain and white flour and the effects of nicotianamine and 2'-deoxymugineic acid on iron uptake into Caco-2 cells

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    Iron bioavailability in unleavened white and wholegrain bread made from two commercial wheat varieties was assessed by measuring ferritin production in Caco-2 cells. The breads were subjected to simulated gastrointestinal digestion and the digests applied to the Caco-2 cells. Although Riband grain contained a lower iron concentration than Rialto, iron bioavailability was higher. No iron was taken up by the cells from white bread made from Rialto flour or from wholegrain bread from either variety, but Riband white bread produced a small ferritin response. The results probably relate to differences in phytate content of the breads, although iron in soluble monoferric phytate was demonstrated to be bioavailable in the cell model. Nicotianamine, an iron chelator in plants involved in iron transport, was a more potent enhancer of iron uptake into Caco-2 cells than ascorbic acid or 2'-deoxymugineic acid, another metal chelator present in plants

    Genetic Contributions to the Midsagittal Area of the Corpus Callosum

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    The degree to which genes and environment determine variations in brain structure and function is fundamentally important to understanding normal and disease-related patterns of neural organization and activity. We studied genetic contributions to the midsagittal area of the corpus callosum (CC) in pedigreed baboons (68 males, 112 females) to replicate findings of high genetic contribution to that area of the CC reported in humans, and to determine if the heritability of the CC midsagittal area in adults was modulated by fetal development rate. Measurements of callosal area were obtained from high-resolution MRI scans. Heritability was estimated from pedigree-based maximum likelihood estimation of genetic and non-genetic variance components as implemented in Sequential Oligogenic Linkage Analysis Routines (SOLAR). Our analyses revealed significant heritability for the total area of the CC and all of its subdivisions, with h2 = .46 for the total CC, and h 2 = .54, .37, .62, .56, and .29 for genu, anterior midbody, medial midbody, posterior midbody and splenium, respectively. Genetic correlation analysis demonstrated that the individual subdivisions shared between 41% and 98% of genetic variability. Combined with previous research reporting high heritability of other brain structures in baboons, these results reveal a consistent pattern of high heritability for brain morphometric measures in baboons

    Design of interactive visualization of models and students data

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    This document reports the design of the interactive visualizations of open student models that will be performed in GRAPPLE. The visualizations will be based on data stored in the domain model and student model, and aim at supporting learners to be more engaged in the learning process, and instructors in assisting the learners

    Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil

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    Iron intakes calculated from one-day weighed records were compared with those from same day analyzed duplicate diet composites collected from 120 Malawian women living in two rural districts with contrasting soil mineralogy and where threshing may contaminate cereals with soil iron. Soils and diet composites from the two districts were then subjected to a simulated gastrointestinal digestion and iron availability in the digests measured using a Caco-2 cell model. Median analyzed iron intakes (mg/d) were higher (p < 0.001) than calculated intakes in both Zombwe (16.6 vs. 10.1 mg/d) and Mikalango (29.6 vs. 19.1 mg/d), attributed to some soil contaminant iron based on high Al and Ti concentrations in diet composites. A small portion of iron in acidic soil from Zombwe, but not Mikalango calcareous soil, was bioavailable, as it induced ferritin expression in the cells, and may have contributed to higher plasma ferritin and total body iron for the Zombwe women reported earlier, despite lower iron intakes. In conclusion, iron intakes calculated from food composition data were underestimated, highlighting the importance of analyzing duplicate diet composites where extraneous contaminant iron from soil is likely. Acidic contaminant soil may make a small but useful contribution to iron nutrition

    Means and covariance functions for geostatistical compositional data: an axiomatic approach

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    This work focuses on the characterization of the central tendency of a sample of compositional data. It provides new results about theoretical properties of means and covariance functions for compositional data, with an axiomatic perspective. Original results that shed new light on the geostatistical modeling of compositional data are presented. As a first result, it is shown that the weighted arithmetic mean is the only central tendency characteristic satisfying a small set of axioms, namely continuity, reflexivity and marginal stability. Moreover, this set of axioms also implies that the weights must be identical for all parts of the composition. This result has deep consequences on the spatial multivariate covariance modeling of compositional data. In a geostatistical setting, it is shown as a second result that the proportional model of covariance functions (i.e., the product of a covariance matrix and a single correlation function) is the only model that provides identical kriging weights for all components of the compositional data. As a consequence of these two results, the proportional model of covariance function is the only covariance model compatible with reflexivity and marginal stability

    Progressive Bidirectional Age-Related Changes in Default Mode Network Effective Connectivity across Six Decades

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    The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20ā€“29 to 70ā€“79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging
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