Lesser Prairie-Chicken Hen and Brood Habitat Use on Sand Shinnery Oak

The structural attributes of shrubland communities may provide thermal refugia and protective cover necessary for wild animals to survive. During the summers of 2002 and 2003, we evaluated the thermal environment for lesser prairie-chicken (Tympanuchus pallidicinctus Ridgway) broods in southeast New Mexico across a complex landscape that included grazed sand shinnery oak (Quercus havardii Rydb.), ungrazed sand shinnery oak treated with tebuthiuron, sand dunes, cropland, and Conservation Reserve Program native grass plantings. Based on data from 257 brood locations and 53 random locations, lesser prairie-chicken broods selected locations based on sand shinnery oak dominance, with taller plant heights and more over-head cover, when temperatures exceeded 26.4°C than what was randomly available. Prairie chickens selected areas not treated with herbicide and these sites were often selected at a fine spatial scale. These data support other studies suggesting that there may be no justification of shrub control for lesser prairie-chicken conservation within the sand shinnery oak communities.     

Weather Variables Affecting Oklahoma Wildfires

Wildfires in the United States can be destructive to human life and property. The ability to predict fire danger helps reduce the risks associated with wildfires by keeping firefighters on high alert and allowing better preparedness. In the state of Oklahoma, fire is a common occurrence. By looking at past wildfire records and researching the weather conditions under which they burned, we were able to determine the most important weather conditions affecting wildfire size. We looked at 10 different weather variables and found that minimum relative humidity (r = 0.98, P = 0.001), maximum and average wind speed (r = 0.95, P = 0.003; r = 0.95, P = 0.004, respectively), and precipitation (r = 0.88, P = 0.02) were the most important factors relating to wildfire size. Temperature variables did not have significant relationships with wildfire size categories. Additionally, we found that most of the largest wildfires occurred in January and December. This information can be used to adjust and improve current wildfire danger models and predictive abilities. We define conditions under which firefighters should be on high alert with hopes of improving their ability to expediently manage rangeland wildfires.     

Quantification of methane emitted by ruminants: a review of methods

The contribution of greenhouse gas (GHG) emissions from ruminant production systems varies between countries and between regions within individual countries. The appropriate quantification of GHG emissions, specifically methane (CH₄), has raised questions about the correct reporting of GHG inventories and, perhaps more importantly, how best to mitigate CH₄ emissions. This review documents existing methods and methodologies to measure and estimate CH₄ emissions from ruminant animals and the manure produced therein over various scales and conditions. Measurements of CH₄ have frequently been conducted in research settings using classical methodologies developed for bioenergetic purposes, such as gas exchange techniques (respiration chambers, headboxes). While very precise, these techniques are limited to research settings as they are expensive, labor-intensive, and applicable only to a few animals. Head-stalls, such as the GreenFeed system, have been used to measure expired CH₄ for individual animals housed alone or in groups in confinement or grazing. This technique requires frequent animal visitation over the diurnal measurement period and an adequate number of collection days. The tracer gas technique can be used to measure CH₄ from individual animals housed outdoors, as there is a need to ensure low background concentrations. Micrometeorological techniques (e.g., open-path lasers) can measure CH₄ emissions over larger areas and many animals, but limitations exist, including the need to measure over more extended periods. Measurement of CH₄ emissions from manure depends on the type of storage, animal housing, CH₄ concentration inside and outside the boundaries of the area of interest, and ventilation rate, which is likely the variable that contributes the greatest to measurement uncertainty. For large-scale areas, aircraft, drones, and satellites have been used in association with the tracer flux method, inverse modeling, imagery, and LiDAR (Light Detection and Ranging), but research is lagging in validating these methods. Bottom-up approaches to estimating CH₄ emissions rely on empirical or mechanistic modeling to quantify the contribution of individual sources (enteric and manure). In contrast, top-down approaches estimate the amount of CH₄ in the atmosphere using spatial and temporal models to account for transportation from an emitter to an observation point. While these two estimation approaches rarely agree, they help identify knowledge gaps and research requirements in practice.     

Phylogeography and conservation gaps of Musa balbisiana Colla genetic diversity revealed by microsatellite markers

Genetic Resources and Crop Evolution - Collection and storage of crop wild relative (CWR) germplasm is crucial for preserving species genetic diversity and crop improvement. Nevertheless, much of...     

Dissolution kinetics of macronutrient fertilizers coated with manufactured zinc oxide nanoparticles

The solubility of Zn in Zn fertilizers plays an important role in the agronomic effectiveness of the fertilizer. On the basis of thermodynamics, zinc oxide (ZnO) nanoparticles (NPs) should dissolve faster and to a greater extent than bulk ZnO particles (equivalent spherical diameter >100 nm). These novel solubility features of ZnO NPs might be exploited to improve the efficiency of Zn fertilizers. In this study, we compared the Zn solubility and dissolution kinetics of ZnO nanoparticles and bulk ZnO particles coated onto two selected granular macronutrient fertilizers, urea and monoammonium phosphate (MAP). The main Zn species on coated MAP and urea granules were zinc ammonium phosphate and ZnO, respectively. Coated MAP granules showed greater Zn solubility and faster dissolution rates in sand columns compared to coated urea granules, which may be related to pH differences in the solution surrounding the fertilizer granules. The kinetics of Zn dissolution was not affected by the size of the ZnO particles applied for coating of either fertilizer type, possibly because solubility was controlled by formation of the same compounds irrespective of the size of the original ZnO particles used for coating.     

Phytoplankton biomass and environmental factors over a gradient of clear to turbid peri‐urban ponds

• 1. Small lakes and ponds with high nutrient loadings can be clear, turbid or intermediate, with low, high and intermediate phytoplankton biomass, respectively.
• 2. A combination of biotic and abiotic factors, such as hydraulic retention time, presence of submerged vegetation, depth, top‐down phytoplankton control, and cascading effects of fish community structure, play an important role in phytoplankton biomass control when nutrients are not limiting. Different combinations of these factors lead to different levels of phytoplankton biomass.
• 3. Identification of the main factors controlling phytoplankton biomass in a particular pond or a small lake is essential for choosing an appropriate management strategy for the maintenance of a desired ecosystem state.
• 4. When a pond or a small lake ecosystem is impaired by eutrophication, a considerable degree of its ecological quality can be restored through the modification of some environmental factors when a sufficient reduction in nutrient input is not feasible.

Copyright © 2006 John Wiley & Sons, Ltd.     

QTL detection for flowering time in faba bean and the responses to ambient temperature and photoperiod

Faba bean (Vicia faba L.) is a grain legume primarily used for animal feed and human food grown in a range of environments, globally. Time of flowering in faba bean is critical for adaptation to specific environments and is controlled largely by factors such as ambient temperature and photoperiod. The aim of this study was to investigate the genetic control of flowering time and the responses of flowering time to ambient temperature and photoperiod in faba bean. A bi-parental recombinant inbred line population (Icarus × Ascot) was evaluated over three years in field trials and three different controlled environments with varying temperatures and photoperiods. QTL analysis identified eight regions of co-localised QTLs associated with days to flowering, thermal time to flowering and node of first flower; on Chr-I.A/III/V, Chr-I.B.3, Chr-III.1, Chr-III.2, Chr-V.1 and Chr-V.2. Two of the detected regions are common with previously detected QTLs, up to two more are possibly common and the remaining four appear to be novel. For the first time, the associations of these QTLs with ambient temperature and photoperiod response were described. Candidate genes for some of the QTLs were identified using the associations with ambient temperature and photoperiod response together with knowledge extended from other legumes that have a syntenic relationship with faba bean.     

Effects of Bacillus subtilis strains and the prebiotic Previda® on growth,immune parameters and susceptibility to Aeromonas hydrophila infection in Nile tilapia,Oreochromis niloticus

This study was conducted to evaluate the individual and combined effects of long‐term feeding of diets containing two probiotic Bacillus subtilis group strains (Aqua NZ and AP193) and the prebiotic Previda^®, a commercial hemicellulose extract, on growth performance, immune parameters and Aeromonas hydrophila susceptibility of juvenile Nile tilapia, Oreochromis niloticus. Nile tilapia of average weight 7.47 ± 0.11 g were fed diets formulated with the probiotics and/or the prebiotic, or a control diet for 8 weeks and, subsequently, challenged with A. hydrophila by intragastric gavage at a dosage of 3.9 × 10⁷ CFU per fish. Fish attained a mean weight of 59.5 ± 0.99 g at the end of the growth period. Under the conditions of the present trial, none of the diets significantly improved mean per cent weight gain (P = 0.70), thermal growth coefficient (P = 0.88) or feed conversion ratio (P = 0.87) of Nile tilapia. Except for the diet containing the prebiotic Previda^® only (P = 0.17), all other diets resulted in significantly higher fish survival compared to the control (P < 0.05). The combined effect of the prebiotic and probiotic strains emerged as the most important diet with respect to mortality reduction. The mean lysozyme and respiratory burst activities did not show any significant differences between treatments and control (P = 0.14 and 0.32, respectively). Thus, these probiotic strains used in this study have the potential to prevent disease due to A. hydrophila in O. niloticus.     

Anti-Inflammatory Activity of Fucoidan Extracts In Vitro

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5–30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.     

Surface metrics: an alternative to patch metrics for the quantification of landscape structure

Modern landscape ecology is based on the patch mosaic paradigm, in which landscapes are conceptualized and analyzed as mosaics of discrete patches. While this model has been widely successful, there are many situations where it is more meaningful to model landscape structure based on continuous rather than discrete spatial heterogeneity. The growing field of surface metrology offers a variety of surface metrics for quantifying landscape gradients, yet these metrics are largely unknown and/or unused by landscape ecologists. In this paper, we describe a suite of surface metrics with potential for landscape ecological application. We assessed the redundancy among metrics and sought to find groups of similarly behaved metrics by examining metric performance across 264 sample landscapes in western Turkey. For comparative purposes and to evaluate the robustness of the observed patterns, we examined 16 different patch mosaic models and 18 different landscape gradient models of landscape structure. Surface metrics were highly redundant, but less so than patch metrics, and consistently aggregated into four cohesive clusters of similarly behaved metrics representing surface roughness, shape of the surface height distribution, and angular and radial surface texture. While the surface roughness metrics have strong analogs among the patch metrics, the other surface components are largely unique to landscape gradients. We contend that the surface properties we identified are nearly universal and have potential to offer new insights into landscape pattern–process relationships. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.