Does Kochia prostrata Spread From Seeded Sites? An Evaluation From Southwestern Idaho,USA

Purposeful introductions of exotic species for rehabilitation efforts following wildfire are common on rangelands in the western United States, though ecological impacts of exotic species in novel environments are often poorly understood. One such introduced species, Kochia prostrata (L.) Schrad (forage kochia) has been seeded on over 200 000 ha throughout the Intermountain West to provide fuel breaks and forage, and to compete with invasive plants. Despite its potential benefits, K. prostrata has been reported to spread from some seeded areas, and no studies have addressed its potential interactions with native species. A systematic investigation is needed to increase understanding of the extent to which K. prostrata spreads from seeded areas, the environmental conditions under which it spreads, and its interactions with the associated plant communities. We sampled 28 K. prostrata postfire rehabilitation and greenstrip seedings in southwestern Idaho, which ranged from 3 to 24 yr since seeding. We analyzed cover of K. prostrata and the associated plant community in adjacent seeded and unseeded areas, and quantified extent of spread from seeded areas. Abundance of K. prostrata was negatively associated with that of most plant functional groups, including native species, but was positively associated with abundance of exotic annual forbs. Kochia prostrata spread to unseeded areas on 89% of sampled sites; distances of the farthest individual from the seeding boundary were greater than those previously reported, ranging from 0 to 710 m, with a mean distance of 208 m. Further, although the area covered by K. prostrata increased with time since seeding, we found no evidence that plant community composition affected spread of K. prostrata. Results contribute to current understanding of potential ecological implications of seeding K. prostrata and will enhance the ability of land managers to make scientifically based management decisions about its use.     

Linking Phenology and Biomass Productivity in South Dakota Mixed-Grass Prairie

Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe the condition of the plant community; the phenology of production can provide inferences about species composition, successional stage, and grazing impacts. We evaluated the productivity and phenology of western South Dakota mixed-grass prairie in the period from 2000 to 2008 using the normalized difference vegetation index (NDVI). The NDVI is based on 250-m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. Growing-season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool- and warm-season species (C₃ and C_4, respectively). Additionally, a variety of phenological indicators including cool-season percentage of TIN were derived from the seasonal profiles of NDVI. Cool-season percentage and TIN were combined to generate vegetation classes, which served as proxies of the conditions of plant communities. TIN decreased with precipitation from east to west across the study area. However, the cool-season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of midsummer precipitation. Cool-season TIN averaged 76.8% of the total TIN. Seasonal accumulation of TIN corresponded closely (R² > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to TIN and cool-season percentage. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool- and warm-season composition, and vegetation classes can improve the efficiency of land management by facilitating the adjustment of stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and temporal dynamics of phenology and TIN in mixed-grass prairie.     

The Impact of Hardwood Line-Planting on Tree and Amphibian Diversity in a Secondary Subtropical Wet Forest of Southeast Puerto Rico

The impact on tree and amphibian diversity of line-planting of tropical hardwoods—mahogany (Swietenia macrophylla × S. mahagoni) and mahoe (Hibiscus elatus)—was studied in a secondary subtropical wet forest of Puerto Rico. Common coqui (Eleutherodactylus coqui) and melodious coqui (E. wightmanae) are the most frequent frog species; forest coqui (E. portoricensis) is less abundant. Although relative abundance means were slightly greater in the undisturbed forest and during the wet season, differences were not statistically significant suggesting that line-planting did not significantly affect amphibian diversity. The line-planted areas had a slightly higher, but not statistically significant diversity, richness, and evenness of tree species than the unplanted forest. Multi-response permutation procedure (MRPP) showed statistically significant community composition differences between line-planting and control plot trees (T = ?5.89, A = .86; p < .001). But mean similarity among plots in both the line-planted and control plots was relatively low at less than 50% of shared species, indicating high diversity of vegetation in the overall forest area. Canopy cover by tree species greater than 3 cm in dbh was much higher in the undisturbed forest but this difference may be reduced as the young line-planted hardwoods mature. Forest enrichment through line-planting of valuable timber species in secondary subtropical wet forest does not significantly affect tree diversity.     

CP7_E2alf oral vaccination confers partial protection against early classical swine fever virus challenge and interferes with pathogeny-related cytokine responses

The conventional C-strain vaccine induces early protection against classical swine fever (CSF), but infected animals cannot be distinguished from vaccinated animals. The CP7_E2alf marker vaccine, a pestivirus chimera, could be a suitable substitute for C-strain vaccine to control CSF outbreaks. In this study, single oral applications of CP7_E2alf and C-strain vaccines were compared for their efficacy to induce protection against a CSF virus (CSFV) challenge with the moderately virulent Bas-Rhin isolate, in pigs as early as two days post-immunization. This work emphasizes the powerful potential of CP7_E2alf vaccine administered orally by a rapid onset of partial protection similar to that induced by the C-strain vaccine. Furthermore, our results revealed that both vaccinations attenuated the effects induced by CSFV on production of the pig major acute phase protein (PigMAP), IFN-α, IL-12, IL-10, and TGF-β1 cytokines. By this interference, several cytokines that may play a role in the pathogeny induced by moderately virulent CSFV strains were revealed. New hypotheses concerning the role of each of these cytokines in CSFV pathogeny are discussed. Our results also show that oral vaccination with either vaccine (CP7_E2alf or C-strain) enhanced CSFV–specific IgG2 production, compared to infection alone. Interestingly, despite the similar antibody profiles displayed by both vaccines post-challenge, the production of CSFV-specific IgG1 and neutralizing antibodies without challenge was lower with CP7_E2alf vaccination than with C-strain vaccination, suggesting a slight difference in the balance of adaptive immune responses between these vaccines.     

Influence of complexation between amylose and a flavored model sponge cake on the degree of aroma compound release

Flavoring is used in the food industry to reinforce the aroma profile of baked cereal goods. During the processing of such products, interactions between starch and aroma compounds can occur, and this may have an impact on aroma release and perception. In the present study, 20 aroma compounds were tested to establish whether they formed complexes with amylose. The structure of the complexes was determined by wide-angle X-ray scattering (WAXS). A cocomplexation study proved that several complexing compounds could be present in the same crystalline aggregate. WAXS and differential scanning calorimetry (DSC) experiments were performed in a flavored model sponge cake at different steps of processing and showed that aroma compounds might form complexes with amylose in a sponge cake as they can do in simple system containing only amylose. Some of the aroma compounds trapped in the sponge cake were quantified, and their release behavior was followed by headspace analysis. The V-type structure could partly explain aroma retention in the product and the rate of aroma release.     

Online RPLC-GC via TOTAD method to isolate (+)-methyl epijasmonate from lemon (Citrus limon Burm.)

Pure (+)-methyl epijasmonate was isolated from lemon ( Citrus limon Burm.) for the first time. To that aim, two commercial essential oils and one homemade extract were included in the present paper. First, a study on the appropriate chromatographic conditions to avoid the epimerization from methyl epijasmonate to the more stable methyl jasmonate was accomplished. The results obtained are discussed. The presence of (+)-methyl epijasmonate in the three samples studied was initially established through the direct injection into GC-MS. However, the overlapping of (+)-methyl epijasmonate with other matrix components made it necessary to employ a multidimensional technique. RPLC-GC analysis via through-oven transfer adsorption-desorption (TOTAD) provided the selectivity and sensitivity required, reflecting that the homemade lemon extract was an adequate natural source to obtain pure (+)-methyl epijasmonate by means of the collection of the corresponding RPLC fraction.     

An Approach to Air Pollution Source–Receptor Solution by Angular Distances

This study presents the analysis of two series of concentrations of airborne particulate matter (APM) collected in two exploratory campaigns aimed at elucidating the source–receptor problem (SRP) in the metropolitan area of Buenos Aires. Although several techniques have been previously applied to interpret these measurements, we have almost exclusively used here the method of angular distances among objects (ADO) to discuss its advantages as a tool in understanding environmental questions within the source–receptor framework. We present a simple method of calculating the ADO, explain its chemical interpretation and the information that is possible to get by classifying the angular distances. A comparison among ADO with principal component analysis and Kohonen artificial neural networks is also discussed.     

Emergence of Edwardsiella piscicida in Farmed Channel ♀, Ictalurus punctatus × Blue ♂, Ictalurus furcatus,Hybrid Catfish Cultured in Mississippi

There is a trend toward the increased incidence and prevalence of Edwardsiella piscicida septicemia in US catfish aquaculture, particularly in channel ♀, Ictalurus punctatus, × blue ♂, I. furcatus, hybrid catfish. From 2013 to 2017, a total of 3242 disease case submissions were made to the Aquatic Research and Diagnostic Laboratory (ARDL) at the Thad Cochran National Warmwater Aquaculture Center in Stoneville, MS. Of these, 1400 (43.2%) were hybrids. E. piscicida was suspected in 138 (4.3%) of cases, the majority of which (89.1%) were from hybrid catfish. A molecular survey of these isolates confirmed the majority (92.0%) to be E. piscicida. Furthermore, cases of E. piscicida from hybrids submitted to the ARDL and the Aquatic Diagnostic Laboratory of the Mississippi State University College of Veterinary Medicine in Starkville, MS, were documented for gross lesions and histological analysis. Grossly, E. piscicida presents with small dermal ulcerations, a raised fluid‐filled cranial midline lesion that is frequently ulcerated, hemorrhage in the gills, exophthalmia, and abdominal distension. Internally, lesions include splenomegaly, straw‐colored ascites, renomegaly, and occasionally hemorrhagic intestines. Histopathological examination is in agreement with gross observations, and infected fish repeatedly demonstrate a mononuclear meningoencephalitis, hemorrhagic branchitis, splenitis, ulcerative dermatitis, granulomatous interstitial nephritis, and hepatitis coupled with a hemorrhagic enteritis.     

A social learning video method: Identifying and sharing successful transformation knowledge for sustainable soil management in Switzerland

To enhance sustainable land use, a From Farmer to Farmer project was conducted in Switzerland (2001–2010). A multi‐stakeholder discussion group co‐produced nine videos with experienced farmers and wine producers showing sustainable soil management practices. We analysed the video audio‐visual content and drew on reflections of the co‐production process, referring to concepts of system, target and transformation knowledge, as well as on social learning. The analysis showed a broad range of means (or actions) for sustainable soil management in arable land management, fodder production and wine growing that are aligned to transformation knowledge. The research showed that farmers refer to three phases of social learning, light‐bulb moments, coping with challenges and gaining successful expertise. These are not just linear processes of individuals. Four types of social learning were found in the video analysis: (a) learning from observing actions of others, (b) sharing experiences with storytelling, (c) informal social interactions and (d) being a role model with a large social network. Videos enable transformation knowledge to be shared with peers using storytelling; this powerful narrative communication style provides credibility and respects the ‘thought style’ of the target audience group. We conclude that for successful implementation of sustainable actions, it is important to address a specific target group and share their transformation knowledge built upon system and target knowledge. The social learning video method is a viable way to enable social learning between science, administration and practice and has potential for fostering change in sustainable soil management.