Ecology of aquatic Ranunculus communities under the Mediterranean climate

The Iberian Peninsula encompasses more than 80% of the species richness of European aquatic ranunculi. The floristic diversity of the phytocoenosis characterised by aquatic Ranunculus and the main physical–chemical factors of the water were studied in 43 localities of the central Iberian Peninsula. Four aquatic Ranunculus communities are found in most of the aquatic environments. These are species-poor and have an uneven distribution: three species of Batrachium are heterophyllous and their communities are distributed in different aquatic ecosystems on silicated substrates; one species is homophyllous and its community occurs in various aquatic ecosystems with carbonated waters. In the Mediterranean climate, Ranunculus species are present in different habitats, as shown by the results of all the statistical analyses. Ranunculus trichophyllus communities occur in base-rich waters with a high buffering capacity (2273.44 ± 794.57 mg CaCO₃ L⁻¹) and a high concentration of cations (Ca²⁺, 121 ± 33.12 mg L⁻¹; Mg²⁺, 71.64 ± 82.77 mg L⁻¹), nitrates (2.89 ± 4.80 mg L⁻¹), ammonium (2.19 ± 1.36 mg L⁻¹) and sulphates (216.25 ± 218.54 mg L⁻¹). Ranunculus penicillatus communities are found in flowing waters with a high concentration of phosphates (0.48 ± 0.6 mg L⁻¹) and intermediate buffering capacity (683.66 ± 446.76 mg CaCO₃ L⁻¹). Both Ranunculus pseudofluitans and Ranunculus peltatus communities grow in waters with low buffering capacity (R. pseudofluitans, 385.91 ± 209.2 mg CaCO₃ L⁻¹; R. peltatus, 263.3 ± 180.36 mg CaCO₃ L⁻¹), and a low concentration of cations (R. pseudofluitans: Ca²⁺, 12.57 ± 9.42 mg L⁻¹; Mg²⁺, 3.42 ± 1.67 mg L⁻¹; R. peltatus: Ca²⁺, 15 ± 18.26 mg L⁻¹; Mg²⁺, 6.26 ± 8.89 mg L⁻¹) and nutrients (R. pseudofluitans: nitrates, 0.23 ± 0.2 mg L⁻¹; phosphates, 0.09 ± 0.1 mg L⁻¹; R. peltatus: nitrates, 0.19 ± 0.21 mg L⁻¹; phosphates, 0.09 ± 0.12 mg L⁻¹); the first in flowing waters, the latter in still waters.     

Tolerance and remedial function of rooted submersed macrophyte Vallisneria spiralis to phenanthrene in freshwater sediments

Tolerance and remedial function of submersed macrophyte Vallisneria spiralis to phenanthrene in freshwater sediments were investigated by manipulating initial phenanthrene concentrations in sediments from 8 to 80 mg kg⁻¹ dry sediment. The biomass growth of V. spiralis on phenanthrene-spiked sediments was not adversely affected until initial phenanthrene concentrations in sediments increased to 80 mg kg⁻¹ dry sediment. V. spiralis might evolve adaptive mechanisms to toxic contaminants in sediment, and then could change the growth patterns in order to decrease the toxicity on its growth. The removal efficiencies of phenanthrene from the planted sediments were 18% higher than those from the sediments without plant even under an initial phenanthrene concentration of 80 mg kg⁻¹ dry sediments. The enhanced removal of phenanthrene in sediments by the plant might be achieved mainly by the synergism between plant roots and microbes in the rhizosphere.     

Mineral nutrition and heterotrophy in the water conservative holoparasite Hydnora Thunb. (Hydnoraceae)

There are large gaps in our understanding of parasite–host nutrient relationships. Our goal was to evaluate transdermal water loss, parasite–host mineral relationships, and heterotrophy in the holoparasitic genus Hydnora. We estimated in situ transdermal water loss in Hydnora and measured nutrient profiles and δ¹³C and δ¹⁵N signatures for Hydnora and hosts in southern Africa and Madagascar. For comparison we also measured δ¹³C and δ¹⁵N for aerial hemiparasites at the same sites. Transdermal water loss in Hydnora ranged from 0.14 ± 0.02 to 0.38 ± 0.04 mg cm⁻² h⁻¹ and was comparable to transpiration rates for water conservative xerophytes. Concentrations of P and K were higher in Hydnora relative to CAM hosts; other mineral concentrations were significantly lower in the parasite or were not different. δ¹³C signatures of holoparasites and hemiparasites relative to their hosts reflected host metabolism and differences in commitment to heterotrophic C gain. Holoparasite δ¹³C values were significantly enriched (by 0.55‰ ± 0.23) compared to host shoot and depleted compared to host root tissues (by −0.97‰ ± 0.12). Holoparasite δ¹³C values were not significantly different compared to the estimated whole host δ¹³C value. δ¹⁵N values for holoparasites and hemiparasites were significantly correlated with hosts. The water conservative nature of Hydnora spp. combined with parasite–host mineral nutrition profiles are suggestive of active processes of solute uptake. Stable isotope fractionation in host tissues dictated significant differences between parasite and host (shoot and root) δ¹³C signatures. The confirmation of complete heterotrophy and the lack of a confounding transpiration stream may make Hydnora a promising model organism for the examination of parasite solute uptake.     

Accumulation, speciation, and coordination of arsenic in an inbred line and a wild type cultivar of the desert plant species Chilopsis linearis (Desert willow)

This study investigated the absorption of arsenic (As), sulfur (S), and phosphorus (P) in the desert plant Chilopsis linearis (Desert willow). A comparison between an inbred line (red flowered) and wild type (white flowered) plants was performed to look for differential responses to As treatment. One month old seedlings were treated for 7 days with arsenate (As₂O₅, As^V) at 0, 20, and 40 mg As^V L⁻¹. Results from the ICP-OES analysis showed that at 20 mg As^V L⁻¹, red flowered plants had 280 ± 11 and 98 ± 7 mg As kg⁻¹ dry wt in roots and stems, respectively, while white flowered plants had 196 ± 30 and 103 ± 13 mg As kg⁻¹ dry wt for roots and stems. At this treatment level, the concentration of As in leaves was below detection limits for both plants. In red flowered plants treated with 40 mg As^V L⁻¹, As was at 290 ± 77 and 151 ± 60 mg As kg⁻¹ in roots and stems, respectively, and not detected in leaves, whereas white flowered plants had 406 ± 36, 213 ± 12, and 177 ± 40 mg As kg⁻¹ in roots, stems, and leaves. The concentration of S increased in all As treated plants, while the concentration of P decreased in roots and stems of both types of plants and in leaves of red flowered plants. X-ray absorption spectroscopy analyses demonstrated partial reduction of arsenate to arsenite in the form of As-(SX)₃ species in both types of plants.     

Nutritional value and intake of aquatic ferns (Azolla filiculoides Lam. and Salvinia molesta Mitchell.) in sows

Aquatic ferns (AFs) such as Azolla filiculoides and Salvinia molesta are grown on swine lagoons in the tropics and used in diets for pigs. The present work is aimed at evaluating their potential as feed ingredients for sows. When presented with ad libitum AFs, gilts weighing 110 ± 14 kg (mean ± SD), were able to ingest 9.1–9.7 kg fresh AF per day (from 597 to 630 g dry matter (DM) per day) and from 1240 to 1428 g DM per day when presented in a dry, ground form. A digestibility study was conducted, using sows weighing 213 ± 9 kg (mean ± SD), which were fed diets containing maize, soybean meal and 0, 150 or 300 g AF kg⁻¹ diet. The presence of AFs had a negative impact on the faecal digestibility of the crude protein, NDF and energy content of the whole diet (P<0.001) and on the ileal protein digestibility, especially with 300 g AFs kg⁻¹ diet. The level of AFs in the diet had no effect on stomach weight (P>0.05) but increased the weight of the rest of the gastrointestinal tract (P<0.001). The rate of AF fibre fermentation in the pig large intestine was measured using an in vitro gas test. The rates were much lower than tropical tree foliage, which can also be used in pig diets in the tropics. This could partly explain the low apparent digestibility of AFs in pigs. In conclusion, the inclusion level of AFs in rations for sows should be limited to 150 g AFs kg⁻¹ diet due to the low digestibility and energy density, as well as the negative impact on the digestibility of the whole diet.     

Morphological and physiological adaptive traits of Mediterranean narrow endemic plants: The case of Centaurea gymnocarpa (Capraia Island,Italy)

A case study on Centaurea gymnocarpa Moris & De Not., a narrow endemic species, was carried out by analyzing its morphological, anatomical, and physiological traits in response to natural habitat stress factors under Mediterranean climate conditions. The results underline that the species is particularly adapted to the environment where it naturally grows. At the plant level, the above-ground/below-ground dry mass (1.73 ± 0.60) shows its investment predominately in the above-ground structure with a resulting total leaf area per plant of 1399 ± 94 cm². The senescent attached leaves at the base of the plant contribute to limit leaf transpiration by shading soil around the plant. Moreover, the dense C. gymnocarpa leaf pubescence, leaf rolling, the relatively high leaf mass area (LMA = 12.3 ± 1.3 mg cm⁻²) and leaf tissue density (LTD = 427 ± 44 mg cm⁻³) contribute to limit leaf transpiration, also postponing leaf death under dry conditions. At the physiological level, a relatively low respiration/photosynthesis ratio (R/P_N) in spring results from high R [2.26 ± 0.59 μmol (CO₂) m⁻² s⁻¹] and P_N [12.3 ± 1.5 μmol (CO₂) m⁻² s⁻¹]. The high photosynthetic nitrogen use efficiency [PNUE = 15.5 ± 0.4 μmol (CO₂) g⁻¹ (N) s⁻¹] shows the large amount of nitrogen (N) invested in the photosynthetic machinery of new leaves, associated to a high chlorophyll content (Chl = 35 ± 5 SPAD units). On the contrary, the highest R/P_N ratio (1.75 ± 0.19) in summer is due to a significant P_N decrease and increase of R in response to drought. The low PNUE [1.5 ± 0.2 μmol (CO₂) g⁻¹ (N) s⁻¹] in this season is indicative of a greater N investment in leaf cell walls which may contribute to limit transpiration. On the contrary, the low R/P_N ratio (0.05 ± 0.02) in winter is resulting from the limited enzyme activity of the respiratory apparatus [R = 0.23 ± 0.08 μmol (CO₂) m⁻² s⁻¹] while the low PNUE [3.5 ± 0.2 μmol (CO₂) g⁻¹ (N) s⁻¹] suggests that low temperatures additionally limit plant production. The experiment of the imposed water stress confirms that the C. gymnocarpa growth capability is in conformity with the severe conditions of its natural habitat, likewise as it may be the case with others narrow endemic species that have occupied niches with similar extreme conditions.     

Production of earthworm Allolobophora parva (Eisen) in cattle dung

Vermicomposting potential of Allolobophora parva is well proven in recent experiments but little is known about its growth and reproduction performance. Efforts were made in this study to assess the biological productivity of A. parva in cattle waste solids under laboratory conditions. The growth and reproduction performance of A. parva was monitored up to its termination state in experimental beddings. A. parva was weighed weekly and cocoons produced during the interval were also counted. The maximum individual biomass and maximum growth rate (wt. mg worm⁻¹ week⁻¹) was 190.9 ± 0.07 mg (after 13 weeks) and 2.66 (after 12th week), respectively. A. parva showed the maximum values of cocoon number (within a week) and reproduction rate: 26 ± 1.12 and 0.74 ± 0.05 cocoon worm⁻¹ week⁻¹, respectively, during the 8th week of vermiculture. Cocoon production in earthworms was terminated after the 17th week of culture. Data suggested that A. parva may acts as a potential candidate to convert negligible organic waste resources into worm biomass for sustainable environmental management.     

Molecular cloning,characterization and mRNA expression of selenium-dependent glutathione peroxidase from abalone Haliotis discus hannai Ino in response to dietary selenium,zinc and iron

A novel selenium-dependent glutathione peroxidase (Se-GPX) was cloned from abalone Haliotis discus hannai Ino (HdhGPx) by homology cloning with degenerate primers and RACE techniques. The full length of HdhGPx cDNA was 963 bp with a 669 bp open reading frame (ORF) encoding 222 amino acids and a 101 bp eukaryotic selenocysteine insertion sequence (SECIS) in 3′ untranslated region (UTR). It was showed that HdhGPx has a characteristic codon at ²³⁵TGA²³⁷ that corresponds to selenocysteine (SeC) as U₇₂. Sequence characterization revealed that HdhGPx contains a characteristic GPx signature motif 2 (₉₆LGLPCNQF₁₀₃), an active site motif (₁₇₉WNFEKF₁₈₄). In addition, two potential N-glycosylation sites (₁₁₂NGTE₁₁₅ and ₁₃₂NLTQ₁₃₅) were identified in HdhGPx. 3D modeling analysis showed that the overall structure of HdhGPx monomer had more similarity to human GPx3 than human GPx1. Relatively higher-level mRNA expression was detected in hepatopancreas, mantle and gonad by real-time PCR assays. The relative expression levels of HdhGPx mRNA in hepatopancreas and haemocytes were detected by real-time PCR in abalone fed with nine different diets containing graded levels of selenium (0.15, 1.32 and 48.7 mg kg^− 1), zinc (6.69, 33.85 and 710.63 mg kg^− 1) and iron (29.17, 65.7 and 1267.2 mg kg^− 1) for 20 weeks, respectively. The results showed that the expressions of HdhGPx mRNA were statistically higher at adequate dietary selenium (1.32 mg kg^− 1), zinc (33.85 mg kg^− 1) and iron (65.7 mg kg^− 1) than those in low dietary minerals, respectively. But HdhGPx mRNA expression levels were down-regulated by high contents of dietary selenium (48.7 mg kg^− 1), zinc (710.63 mg kg^− 1) and iron (1267.2 mg kg^− 1), respectively. These results indicated that adequate dietary minerals could increase the mRNA expression of HdhGPx, and then to increase the total antioxidant capacities in abalone.     

Growth, reproductive and photosynthetic responses to copper in the yellow-horned poppy, Glaucium flavum Crantz.

Glaucium flavum Crantz. is found in an anthropized coastal grassland at the joint estuary of the Tinto and Odiel rivers (SW Spain), growing under the influence of high levels of copper contamination derived from nearby petrochemical industries, with no obvious adverse affects on the performance of the plant. In addition, this species exhibits a series of ecological characteristics which may render it appropriate for use in the phytoremediation of contaminated areas. Nonetheless, the response of G. flavum to elevated copper concentrations has not been studied. A greenhouse experiment was conducted to investigate the effects of a range of Cu concentrations (0 to 47 mmol l⁻¹) on the growth, reproduction and photosynthetic performance of G. flavum, by measuring relative growth rate, fruit and seed production, chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. We also determined total copper, nitrogen, phosphorous, sulphur, calcium and magnesium concentrations. G. flavum survived with concentrations of up to 730 mg Cu kg⁻¹ DW in the leaves, when treated with 30 mmol Cu l⁻¹ (2000 mg l⁻¹). Quantum efficiency of PSII, net photosynthesis rate, as well as leaf Ca and Mg concentrations were all negatively affected by Cu concentrations greater than 9 mmol l⁻¹ in the nutrient solution. Our results indicate that the reduction in photosynthetic performance may be attributed to the adverse effect of excess Cu on the photosynthetic apparatus of the plant, both directly, via a decrease in pigment concentrations, and indirectly, via interference of Cu with Ca ions of PSII. Growth and seed production were only slightly affected by leaf tissue concentrations as high as 230 mg Cu kg⁻¹ dry mass, which suggests that this species could play an important role in phytoremediation of Cu-contaminated soils.     

Chemical profile of the North American native Myriophyllum sibiricum compared to the invasive M. spicatum

Myriophyllum spicatum L. is a nonindigenous invasive plant in North America that can displace the closely related native Myriophyllum sibiricum Komarov. We analyzed the chemical composition (including: C, N, P, polyphenols, lignin, nonpolar extractables, and sugars) of M. spicatum and M. sibiricum and determined how the chemistry of the two species varied by plant part with growing environment (lake versus tank), irradiance (full sun versus 50% shading), and season (July through September). M. spicatum had higher concentrations of carbon, polyphenols and lignin (C: 47%; polyphenols: 5.5%; lignin: 18%) than M. sibiricum (C: 42%; polyphenols: 3.7%; lignin: 9%) while M. sibiricum had a higher concentration of ash under all conditions (12% versus 8% for M. spicatum). Apical meristems of both species had the highest concentration of carbon, polyphenols, and tellimagrandin II, followed by leaves and stems. Tellimagrandin II was present in apical meristems of both M. spicatum (24.6 mg g⁻¹ dm) and M. sibiricum (11.1 mg g⁻¹ dm). Variation in irradiance from 490 (shade) to 940 (sun) μmol of photons m⁻² s⁻¹ had no effect on C, N, and polyphenol concentrations, suggesting that light levels above 490 μmol of photons m⁻² s⁻¹ do not alter chemical composition. The higher concentration of polyphenols and lignin in M. spicatum relative to M. sibiricum may provide advantages that facilitate invasion and displacement of native plants.     

Evaluation of selenite bioremoval from liquid culture by Enterococcus species

The genus Enterococcus belong to the genera of bacteria that produce lactic acid and can confer health benefits to living organisms. Selenium (Se) is an essential micronutrient for humans and animals. Thirty-six Enterococcus species isolated from dairy products were screened for Se(IV) sorption capacity for use as a probiotics in animal nutrition. Several isolates grew luxuriantly and significantly removed Se(IV) from Se(IV) amended medium. Two isolates, LAB 14 and LAB 18, identified by 16S rRNA gene sequence analysis as Enterococcus faecalis (98% nucleotide sequence similarity) and Enterococcus faecium (97% nucleotide sequence similarity), respectively, were selected for further studies. The two isolates grew optimally and removed selenium at initial pH 7.0. Optimum removal of Se(IV) from the medium was recorded at 25 °C. Time course studies showed that after 8 h of incubation LAB 14 and LAB 18 cultures displayed the highest biomass production and Se(IV) bioremoval and most selenite in culture depleted in 24 h. At initial concentrations of 10 mg L⁻¹ and 60 mg L⁻¹, E. faecium (LAB 18) removed 9.91 mg L⁻¹ and 59.70 mg L⁻¹, respectively after 24 h. Similar Se(IV) bioremoval capacity was recorded with E. faecalis (LAB 14). Substantial amount of Se was detected in biomass of E. faecium (0.4599 mg g⁻¹ of dry weight) and E. faecalis (0.4759 mg g⁻¹ of dry weight). The significant uptake and transformation of Se(IV) by the Enterococcus species observed in this study suggest that they can be used to deliver dietary Se through feed augmentation with Se(IV)-enriched Enterococcus biomass.     

Vitellogenesis and other physiological responses induced by 17-β-estradiol in males of freshwater fish Rhamdia quelen

This study investigated the effects of different doses of 17-β-estradiol (E₂) in Rhamdia quelen. Groups of males exposed to different doses of E₂ (0.1 mg kg^− 1, 1 mg kg^− 1 and 10 mg kg^− 1) were compared with non-exposed male and female fish groups. Among the considered biomarkers, no significant differences were observed for micronuclei test, reduced glutathione concentration and lipid peroxidation. All E₂-treated individuals had decreased glutathione S-transferase activity. Increased catalase and superoxide dismutase activities, increased vitellogenin expression and decreased metallothionein concentration were observed in males treated with the highest dose. Liver of all test groups showed necrotic areas, but cytoplasm vacuolization was again found only in the individuals exposed to highest dose. E₂ causes deleterious hepatic effects to R. quelen, and vitellogenin expression, catalase and superoxide dismutase activity and metallothionein concentration represent appropriate biomarkers for studying E₂ effects. Additionally, the response of some biomarkers was similar in males exposed to E₂ and unexposed females, and therefore exposure to endocrine disruptors may cause consequences for fish populations.     

Effects of the methane-inhibitors nitrate,nitroethane, lauric acid,Lauricidin and the Hawaiian marine algae Chaetoceros on ruminal fermentation in vitro

The effects of several methane-inhibitors on rumen fermentation were compared during three 24 h consecutive batch cultures of ruminal microbes in the presence of nonlimiting amounts of hydrogen. After the initial incubation series, methane production was reduced greater than 92% from that of non-treated controls (25.8 ± 8.1 μmol ml⁻¹ incubation fluid) in cultures treated with nitroethane, sodium laurate, Lauricidin^® or a finely-ground product of the marine algae, Chaetoceros (added at 1, 5, 5 and 10 mg ml⁻¹, respectively) but not in cultures treated with sodium nitrate (1 mg m1⁻¹). Methane production during two successive incubations was reduced greater than 98% from controls (22.5 ± 3.2 and 23.5 ± 7.9 μmol ml⁻¹, respectively) by all treatments. Reductions in amounts of volatile fatty acids and ammonia produced and amounts of hexose fermented, when observed, were most severe in sodium laurate-treated cultures. These results demonstrate that all tested compounds inhibited ruminal methane production in our in vitro system but their effects on fermentation differed.     

Characterization of a new insect cell line (NTU-YB) derived from the common grass yellow butterfly, Eurema hecabe (Linnaeus) (Pieridae: Lepidoptera) and its susceptibility to microsporidia

A new lepidopteran cell line, NTU-YB, was derived from pupal tissue of Eurema hecabe (Linnaeus) (Pieridae: Lepidoptera). The doubling time of YB cells in TNM-FH medium supplemented with 8% FBS at 28 °C was 26.87 h. The chromosome numbers of YB cells varied widely from 21 to 196 with a mean of 86. Compared to other insect cell lines, the YB cells produced distinct esterase, malate dehydrogenase, and lactate dehydrogenase isozyme patterns. Identity of the internal transcribed spacer region-I (ITS-I) of YB cells to E. hecabe larvae was 96% and to Eurema blanda larvae (tissue isolated from head) was 81%. The YB cells were permissive to Nosema sp. isolated from E. blanda and the infected YB cells showed obvious cytopathic effects after 3 weeks post inoculation. The highest level of spore production was at 4 weeks post inoculation when cells were infected with the Nosema isolate, and spore production was 1.34 ± 0.9 × 10⁶ spore/ml. Ultrastructrual studies showed that YB cells can host in vitro propagation of the E. blanda Nosema isolate, and developing stages were observed in the host cell nuclei as observed in the natural host, E. blanda. The NTU-YB cell line is also susceptible to Nosema bombycis.     

Characterization of alkaline thermostable keratinolytic protease from thermoalkalophilic Bacillus halodurans JB 99 exhibiting dehairing activity

A thermostable alkaline protease produced from Bacillus sp. JB 99 exhibited significant keratinolytic and dehairing activity. The enzyme was purified by ammonium sulphate precipitation followed by CM-cellulose and Sephadex G-100 chromatography and resulted in 13.6 fold purification with 23.8% of recovery. The specific activity of purified enzyme was 2989.6 U mg^−l. Purified protease had a molecular weight of 29 kDa and appeared as a single band. Gelatin zymogram analysis also revealed a clear hydrolytic zone, which corresponded to the band obtained with SDS-PAGE. The optimum pH and temperature for the keratinolytic activity was pH 11.0 and 70 °C respectively and half life of protease was 70 °C for 4 h. N-terminal amino acid sequence of purified enzyme exhibited extensive homology with other thermostable alkaline proteases and inhibition by PMSF indicated serine type of protease. The K_m and V_max of protease for keratin substrate were 3.8 ± 0.5 mg ml⁻¹ and 15.1 ± 1.6 ??m min⁻¹ mg⁻¹ and casein were 3.3 ± 0.4 mg ml^−l and 15.6 ± 0.9 ??m min⁻¹ mg⁻¹ respectively. The enzyme efficiently dehaired buffalo and goat hide without damaging the collagen layer, which makes it a potential candidate for application in leather industry to avoid pollution problem associated with the use of chemicals in the industry. The enzyme also degraded chicken feathers in presence of reducing agent which can help poultry industry in management of keratin-rich waste and obtaining value added products.     

Evaporative water loss and energy metabolic in two small mammals,voles (Eothenomys miletus) and mice (Apodemus chevrieri), in Hengduan mountains region

Evaporative water loss (EWL) and energy metabolism were measured at different temperatures in Eothenomys miletus and Apodemus chevrieri in dry air. The thermal neutral zone (TNZ) of E. miletus was 22.5–30 °C and that of A. chevrieri was 20–27.5 °C. Mean body temperatures of the two species were 35.75±0.5 and 36.54±0.61 °C. Basal metabolic rates (BMR) were 1.92±0.17 and 2.7±0.5 ml O₂/g h, respectively. Average minimum thermal conductance (C_m) were 0.23±0.08 and 0.25±0.06 ml O₂/g h °C. EWL in E. miletus and A. chevrieri increased with the increase in temperature; the maximal EWL at 35 °C was 4.78±0.6 mg H₂O/g h in E. miletus, and 5.92±0.43 mg H₂O/g h in A. chevrieri. Percentage of evaporative heat loss to total heat production (EHL/HP) increased with the increase in temperature; the maximal EHL/HP was 22.45% at 30 °C in E. miletus, and in A. chevrieri it was 19.96% at 27.5 °C. The results may reflect features of small rodents in the Hengduan mountains region: both E. miletus and A. chevrieri have high levels of BMR and high levels of total thermal conductance, compared with the predicted values based on their body masses, while their body temperatures are relatively low. EWL plays an important role in temperature regulation.     

Growth and annual production of the brown alga Laminaria japonica (Phaeophyta, Laminariales) introduced into the Uwa Sea in southern Japan

The brown alga Laminaria japonica is distributed from southern Hokkaido to the northeastern Honshu in Japan. Recently, aquaculture of L. japonica has expanded to the southern coast of Japan and to China along the East China Sea. In order to elucidate the growth, biomass and productivity of L. japonica in a subtropical area, we cultivated and examined it in the Uwa Sea, in southwestern Japan over a period of 2 years. The seawater temperature ranged from 13.8 to 26.8 °C in 2001/2002 and from 13.1 to 27.2 °C in 2002/2003. In 2001/2002, the maximum density, maximum mean length and maximum mean wet wt. of L. japonica were 59.7 ± 28.0 ind. 50 cm^− 1 (mean ± S.D.), 187.5 ± 82.7 cm (360 cm in the largest individual) and 130.1 ± 94.6 g wet wt., respectively. In 2002/2003, these values were 94.7 ± 22.2 ind. 50 cm^− 1, 159.3 ± 74.4 cm (300 cm in the largest individual) and 95.2 ± 69.5 g wet wt., respectively. Thus, the length and weight increased when the density was low (2001/2002), and the length and weight decreased when the density was high (2002/2003). The maximum biomass was estimated to be 7200 ± 3400 g wet wt. 50 cm^− 1 in 2001/2002 and 7300 ± 2000 g wet wt. 50 cm^− 1 in 2002/2003. Annual production was estimated to be 33.3 kg wet wt. m^− 1 year^− 1 in 2001/2002 and 34.0 kg wet wt. m^− 1 year^− 1 in 2002/2003. The present study indicates that the annual production of L. japonica per rope of 1 m at Uwajima Bay, the Uwa Sea corresponded to 1.1-2.2 m² of that of Hokkaido in their native area. Thus, the present study indicates that L. japonica is highly adaptable because it is able to keep a high level of productivity when grown in water with a high temperature.     

Physiological,morphological and anatomical trait variations between winter and summer leaves of Cistus species

Morphological, anatomical and physiological summer and winter leaf traits of Cistus incanus subsp. incanus, C. salvifolius and C. monspeliensis growing at the Botanical garden of Rome were analyzed. With regard to differences between summer and winter leaves of the considered species, leaf thickness (L) was 21% higher in summer than in winter leaves (mean of the considered species) and this increase was mostly the result of the increased palisade parenchyma thickness over the spongy parenchyma one (24 and 16% higher in summer than in winter leaves, respectively). Leaf mass area (LMA) and leaf tissue density (LTD) were 38% and 17% higher in summer than in winter leaves, respectively (mean of the considered species). The photosynthetic rate (P_N), stomatal conductance (g_s) and chlorophyll content (Chl) of summer leaves were 54%, 17% and 14% lower, respectively, than in winter leaves. C. monspeliensis summer leaves had the highest LMA, LTD, adaxial cuticle thickness (14.6 ± 1.8 mg cm⁻², 1091 ± 94 mg cm⁻³, and 5.8 ± 1.7 μm, respectively) and the lowest mesophyll intercellular spaces (f_ias 38 ± 3%). Moreover, C. monspeliensis had the highest P_N in summer (2.6 ± 0.1 μmol m⁻² s⁻¹) and C. incanus the highest P_N and WUE (84% and 59% higher than the other species) in the favorable period, associated to a higher f_ias (42 ± 2%). C. salvifolius had the highest P_N (54% higher than the other species) in winter. The plasticity index could allow a better interpretation of the habitat preference of the considered species. The physiological plasticity (PI_p = 0.39, mean value of the considered species) was higher than the morphological (PI_m = 0.22, mean value) and anatomical (PI_a = 0.13, mean value) plasticity. Moreover, among the considered species, C. salvifolius and C. incanus are characterized by a larger PI_a (0.14, mean value) which seems to be correlated with their wider ecological distribution and the more favorable conditions of the environments where they naturally occur. The highest PI_m (0.29) of C. monspeliensis indicates that it can play a high adaptive role in highly stressed environments, like fire degraded Mediterranean areas in which it occurs.     

Decolorization of malachite green by cytochrome c in the mitochondria of the fungus Cunninghamella elegans

We studied the decolorization of malachite green (MG) by the fungus Cunninghamella elegans. The mitochondrial activity for MG reduction was increased with a simultaneous increase of a 9-kDa protein, called CeCyt. The presence of cytochrome c in CeCyt protein was determined by optical absorbance spectroscopy with an extinction coefficient (E_550-535) of 19.7 ± 6.3 mM⁻¹ cm⁻¹ and reduction potential of + 261 mV. When purified CeCyt was added into the mitochondria, the specific activity of CeCyt reached 440 ± 122 μmol min⁻¹ mg⁻¹ protein. The inhibition of MG reduction by stigmatellin, but not by antimycin A, indicated a possible linkage of CeCyt activity to the Qo site of the bc1 complex. The RT-PCR results showed tight regulation of the cecyt gene expression by reactive oxygen species. We suggest that CeCyt acts as a protein reductant for MG under oxidative stress in a stationary or secondary growth stage of this fungus.     

Age-related intramuscular pharmacokinetics of cefquinome in sheep

The pharmacokinetic profile of cefquinome was studied in one, six-months and one year old sheep following a single intramuscular doses of 1 and 10 mg kg⁻¹ b.wt. Cefquinome concentrations in serum were determined by microbiological assay technique using Micrococcus luteus (ATCC 9341) as test organism. Following intramuscular administration of cefquinome, the absorption half-lives (t_0.5(ab)) were 1.540, 1.037 and 0.664 h at a dose of 1 mg kg⁻¹ b.wt. and 1.844, 1.290 and 1.605 h at a dose of 10 mg kg⁻¹ b.wt. in the three ages, respectively. After the two doses, the maximum serum concentrations (C_max) of 0.732, 1.145, 1.205 and 3.525, 5.088, 4.576 μg ml⁻¹ were attained after (t_max) of 3.812, 3.029, 2.174 and 3.785, 2.824, 3.095 h in the three ages, respectively. The elimination half-life (t_0.5(el)) and MRT values of cefquinome were longer in one-month old sheep compared to six-months old and yearling sheep. The absorption and elimination processes were delayed in newborn sheep of one-month old in contrary to six-month and yearling animals. The in vitro serum protein-binding tendencies were 8.254%, 11.586% and 13.002%, for one, six-months and one year old sheep, respectively. Based on this study and economically, an optimal intramuscular dosage regimen of cefquinome would be 1 mg kg⁻¹ once daily in one-month, six-months and one-year old sheep to achieve and maintain the therapeutic serum levels within safe limits.