Mexican Arnica Anti–Inflammatory Action: Plant Age is Correlated with the Concentration of Anti–Inflammatory Sesquiterpenes in the Medicinal Plant <Emphasis Type="Italic">Heterotheca inuloides</Emphasis> Cass. (Asteraceae)<Superscript>1</Superscript>

Mexican Arnica Anti–Inflammatory Action: Plant Age Is Correlated with the Concentration of Anti–inflammatory Sesquiterpenes in the Medicinal Plant Heterotheca inuloides Cass. (Asteraceae). Mexican árnica (Heterotheca inuloides Cass.) is a widely used anti–inflammatory medicinal plant in Mexican folk medicine. Although it has been suggested that plant age, fertilization, and harvesting regime influence the concentration of secondary compounds affecting the therapeutic activity of the plant, the effect of these variables on the concentration of the Mexican árnica anti–inflammatory compounds was not known. We quantified anti–inflammatory sesquiterpenes (caryolan–1, 9β–diol, cadalen–15–oic acid, 7–hydroxycadalene, 4–hydroxy–2–isopropyl–4, 7–dimethyl–1[4H] naftalinone, 7–hydroxy–4αH–3, 4–dihydrocadalene, β–caryophyllene, and β–caryophyllene epoxide) in Mexican árnica plants subjected to fertilization and successive harvests of flowering stems, conditions that mimic the cultivation and harvesting for árnica in México. Fertilization and successive harvesting and their interaction had no significant effect on the concentration of anti–inflammatory compounds. However, the concentrations of these compounds were 60% higher in flowering stems from 15–month–old plants than in those from 4– or 8–month–old plants and was independent of the number of harvests and fertilization regime applied.     

An index approach to assess nitrogen losses to the environment

Nitrogen (N) losses from agriculture are negatively impacting groundwater, air, and surface water quality. New tools are needed to quickly assess these losses and provide nutrient managers and conservationists with effective tools to assess the effects of current and alternative management practices on N loss pathways. A new N-Index tool was developed in spreadsheet format, allowing prompt assessments of management practices on agricultural N losses. The N-Index tool was compared with experimental field data and shown to estimate the effects of management practices on N loss pathways (probability, P < 0.001). The N-Index correctly assessed the nitrate nitrogen (NO₃-N) leaching losses when tested against measured NO₃-N leaching data and atmospheric N losses collected over multiple years (annual basis) and locations. The N-Index tool was developed with international cooperation from several countries and there is potential to use this tool at the international level.     

Is Shade Beneficial for Mediterranean Shrubs Experiencing Periods of Extreme Drought and Late-winter Frosts?

Background and Aims

Plants are naturally exposed to multiple, frequently interactive stress factors, most of which are becoming more severe due to global change. Established plants have been reported to facilitate the establishment of juvenile plants, but net effects of plant–plant interactions are difficult to assess due to complex interactions among environmental factors. An investigation was carried out in order to determine how two dominant evergreen shrubs (Quercus ilex and Arctostaphylos uva-ursi) co-occurring in continental, Mediterranean habitats respond to multiple abiotic stresses and whether the shaded understorey conditions ameliorate the negative effects of drought and winter frosts on the physiology of leaves.

Methods

Microclimate and ecophysiology of sun and shade plants were studied at a continental plateau in central Spain during 2004–2005, with 2005 being one of the driest and hottest years on record; several late-winter frosts also occurred in 2005.

Key Results

Daytime air temperature and vapour pressure deficit were lower in the shade than in the sun, but soil moisture was also lower in the shade during the spring and summer of 2005, and night-time temperatures were higher in the shade. Water potential, photochemical efficiency, light-saturated photosynthesis, stomatal conductance and leaf ¹³C composition differed between sun and shade individuals throughout the seasons, but differences were species specific. Shade was beneficial for leaf-level physiology in Q. ilex during winter, detrimental during spring for both species, and of little consequence in summer.

Conclusions

The results suggest that beneficial effects of shade can be eclipsed by reduced soil moisture during dry years, which are expected to be more frequent in the most likely climate change scenarios for the Mediterranean region.Key words: Frost, climate change, shade, drought, plant–plant interactions, Quercus ilex, Arctostaphylos uva-ursi, soil moisture, facilitation     

FEEDING ECOLOGY OF THE MARINE OTTER (LUTRA FELINA) IN A ROCKY SEASHORE OF THE SOUTH OF CHILE

The marine otter ( Lutra felina ) lives exclusively along exposed rocky shorelines on the South American Pacific coast from Peru (6°S), to Cape Horn, Chile (56°S), and Isla de los Estados, Argentina. L. felina diet and its relationship to prey availability and energy content was assessed by spraint and prey remains analysis, direct observation, and the use of crab pots and fish traps, at four sites on the Valdivian coast in the south of Chile, between June 1999 and June 2000. Based on spraints analysis, the diet was composed of 25 species; 52% (13/25) of the species identified were crustaceans, 40% (10/25) were fish, and 8% (2/25) were mollusks. Crustaceans were found in 78% of 475 spraints, 100% of 929 prey remains, and 90.8% of prey determined by direct observation, fish in 20% of spraints and 9.0% of prey determined by direct observation, and mollusks in 2% of spraints and 0.2% of prey determined by direct observation. Observed seasonal variation in prey availability was reflected in the otter diet. Fourteen prey species were trapped; 43% (6/14) were crustaceans and 57% (8/14) fish, crustaceans were 93% of 566 trapped individuals, fish 7%. L. felina showed opportunistic feeding behavior, selecting prey seasonally according to their availability rather than to their energy input.     

Behavioral states help translate dispersal movements into spatial distribution patterns of floaters

Within the field of spatial ecology, it is important to study animal movements in order to better understand population dynamics. Dispersal is a nonlinear process through which different behavioral mechanisms could affect movement patterns. One of the most common approaches to analyzing the trajectories of organisms within patches is to use random-walk models to describe movement features. These models express individual movements within a specific area in terms of random-walk parameters in an effort to relate movement patterns to the distributions of organisms in space. However, only using the movement trajectories of individuals to predict the spatial spread of animal populations may not fit the complex distribution of individuals across heterogeneous environments. When we empirically tested the results from a random-walk model (a residence index) used to predict the spatial equilibrium distribution of individuals, we found that the index severely underestimated the spatial spread of dispersing individuals. We believe this is because random-walk models only account for the effects of environmental conditions on individual movements, completely overlooking the crucial influence of behavior changes over time. In the future, both aspects should be accounted for when predicting general rules of (meta)population abundance, distribution, and dynamics from patterns of animal movements.     

Delayed partial liquid ventilation shows no efficacy in the treatment of smoke inhalation injury in swine.

In an earlier neonatal porcine model of smoke inhalation injury (SII), immediate postinjury application of partial liquid ventilation (PLV) had dramatic beneficial effects on lung compliance, oxygenation, and survival over a 24-h period. To explore the efficacy of PLV following SII, we treated animals at 2 and 6 h after SII and followed them for 72 h. Pigs weighing 8-12 kg were sedated and pharmacologically paralyzed, given a SII, and placed on volume-cycled, pressure-limited ventilation. Animals were randomized to three groups: group I (+SII, no PLV, n = 8), group II (+SII, PLV at 2 h, n = 6), and group III (+SII, PLV at 6 h, n = 7). Ventilatory parameters and arterial blood gasses were obtained at scheduled intervals. The PLV animals (groups II and III) followed a worse course than group I (no PLV); PLV groups had higher peak and mean airway pressures, oxygenation index, and rate-pressure product (a barotrauma index) and lower lung compliance and arterial partial pressure of oxygen-to-inspired oxygen fraction ratio (all P < 0.05). PLV conferred no survival advantage. The reported beneficial effects of PLV with other models of acute lung injury do not appear to extend to the treatment of SII when PLV is instituted in a delayed manner. This study was not able to validate the previously reported beneficial effects of PLV in SII and actually found deleterious effects, perhaps reflecting the predominance of airway over alveolar disease in SII.     

A new species of Viola L. (Violaceae) from South Anatolia

A new species of Viola L., Viola yildirimlii M. Dinç & Y. Bağcı sp. nov. from South Anatolia is described and illustrated. It is found on the rocky slopes of Aladağ National Park, in the county of Adana, south Turkey, at an elevation of 1800 m. It belongs to Viola , subsect. Viola , and is similar to the Turkish endemics Viola isaurica Contandr. & Quézel and V. kizildaghensis M. Dinç & Ş. Yıldırımlı. Diagnostic morphologic characters for a detailed discrimination from two similar taxa and other Turkish Eflagellatae species are discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 477–482.     

In Situ Determination of the Intracellular pH of Lactococcus lactis and Lactobacillus plantarum during Pressure Treatment

Hydrostatic pressure may affect the intracellular pH of microorganisms by (i) enhancing the dissociation of weak organic acids and (ii) increasing the permeability of the cytoplasmic membrane and inactivation of enzymes required for pH homeostasis. The internal pHs of Lactococcus lactis and Lactobacillus plantarum during and after pressure treatment at 200 and 300 MPa and at pH values ranging from 4.0 to 6.5 were determined. Pressure treatment at 200 MPa for up to 20 min did not reduce the viability of either strain at pH 6.5. Pressure treatment at pH 6.5 and 300 MPa reduced viable cell counts of Lactococcus lactis and Lactobacillus plantarum by 5 log after 20 and 120 min, respectively. Pressure inactivation was faster at pH 5 or 4. At ambient pressure, both strains maintained a transmembrane pH gradient of 1 pH unit at neutral pH and about 2 pH units at pH 4.0. During pressure treatment at 200 and 300 MPa, the internal pH of L. lactis was decreased to the value of the extracellular pH during compression. The same result was observed during treatment of Lactobacillus plantarum at 300 MPa. Lactobacillus plantarum was unable to restore the internal pH after a compression-decompression cycle at 300 MPa and pH 6.5. Lactococcus lactis lost the ability to restore its internal pH after 20 and 4 min of pressure treatment at 200 and 300 MPa, respectively. As a consequence, pressure-mediated stress reactions and cell death may be considered secondary effects promoted by pH and other environmental conditions.     

Chromosomal integration and expression of green fluorescent protein in Zymomonas mobilis

An integrative vector was constructed to allow expression of heterologous proteins into the adhB locus of Zymomonas mobilis. As a reporter gene, the ORF of a bright variant of green fluorescent protein from Aequorea victoria (GFPuv) was fused to the adhB strong promoter from Z. mobilis by using a two-step PCR strategy. Z. mobilis recombinant strains that were stably marked by precise gene replacement at adhB locus with a single chromosomal copy of gfpuv. Protein expression was confirmed by fluorescence microscopy and measured by fluorescence spectroscopy, showing high expression levels (12 to 30 times higher than those obtained in E. coli) without affecting the host growth.