A generalized nonlinear mixed-effects height–diameter model for Eucalyptus globulus L. in northwestern Spain

A generalized height–diameter model was developed for Eucalyptus globulus Labill. stands in Galicia (northwestern Spain). The study involved a variety of pure stands ranging from even-aged to uneven-aged. Data were obtained from permanent circular sample plots in which trees were sampled within different radii according to their diameter at breast height. A combination of weighted regression, to take into account the unequal selection probabilities of such an inventory design, and mixed model techniques, to accommodate local random fluctuations in the height–diameter relationship, were applied to estimate fixed and random parameters for several models reported in the relevant literature. The models that provided the best results included dominant height and dominant diameter as fixed effects. These models explained more than 83% of the observed variability, with mean errors of less than 2.5 m. Random parameters for particular plots were estimated with different tree selection options. Height–diameter relationships tailored to individual plots can be obtained by calibration of the height measurements of the three smallest trees in a plot. An independent dataset was used to test the performance of the model with data not used in the fitting process, and to demonstrate the advantages of calibrating the mixed-effects model.     

Intensification of the Giant river prawn Macrobrachium rosenbergii hatchery production

We evaluated the effect of intensification on Macrobrachium rosenbergii hatchery in clear water recirculating system. Larvae were raised in 120‐L cylindrical tanks coupled with 30‐L biofilters. We performed two experiments in randomized blocks. In the first, we tested the stocking densities of 50, 70 and 90 newly hatched larvae L^?1. Survival did not differ by anova (P = 0.343), but productivity increased with the intensification (P = 0.038). In the second experiment, we tested the stocking densities of 80, 100, 120 and 140 newly hatched larvae L^?1. Survival decreased (P = 0.039) as density increased, but productivity did not differ (P = 0.317). The period of culture ranged from 22 to 23 days. The intensification did not influence water quality parameters or larval development. Survival decreased with the intensification and the space showed to be a limiting factor on tanks stocked with 90 larvae L^?1 or more. Productivity curve shows an increase from 50 to 100 larvae L^?1 and tended to reach plateau on stocking densities higher than 100 larvae L^?1. In addition, the intensification improved the use of Artemia cysts by decreasing the superfluous feeding. Thus, we recommend stocking of 80 to 100 newly hatched larvae L^?1 as the best option for M. rosenbergii hatchery in clear water recirculating system.     

Guava decline: effect of root exudates from Meloidogyne enterolobii-parasitized plants on Fusarium solani in vitro and on growth and development of guava seedlings under controlled conditions

In guava decline, Fusarium solani-immune guava trees become susceptible to extensive root rot caused by this fungus after parasitism by Meloidogyne enterolobii. To understand the mechanisms involved in this disease, root exudates were collected from nematode-inoculated (NI) or uninoculated (UN) guava plants cultivated in sand. After filtration through a Millipore® membrane, NI and UN exudates were used: i) to prepare media to assess their effect on mycelial growth and production of propagules of F. solani isolate UENF/CF 163, and ii) to incubate macro- and microconidia to assess their effect on germination. NI exudates promoted (P?<?0.05) more mycelial growth and production of propagules than UN exudates or water. NI and UN exudates were used to water guava seedlings laid over seed germination paper inside plastic boxes. Half of the seedlings had an agar plug colonized by the fungus positioned in the collar region. Upon watering with NI exudates the fungus caused (P?<?0.05) extensive rotting of the seedlings’ rootlets. NI and UN exudates, either unlyophilized or lyophilized and re-suspended to the original concentration, were used to water guava seedlings grown in sterile sand before being inoculated (or left uninoculated) as described before. Solely upon watering with NI exudates, in its unlyophilized form or after lyophilization, the fungus caused a reduction (P?<?0.05) of shoot and root biomass associated with rotting of roots. These results suggest that M. enterolobii induces chemical changes in the root exudates of guava trees, which are necessary for root invasion causing root rotting by F. solani.     

The pyrethroid resistance status and mechanisms in Aedes aegypti from the Guerrero state,Mexico

Dengue is one of the most important vector-borne diseases worldwide and is a public health problem in Mexico. Most programs in dengue endemic countries rely on insecticides for Aedes control. In Mexico, pyrethroid insecticides (mainly permethrin and deltamethrin) have been extensively used over a decade as adulticides and represented a strong selection for insecticide resistance for dengue vectors in several parts of the country. We studied the type, frequency and distribution of insecticide resistance mechanisms in Aedes aegypti from six municipalities in the state of Guerrero selected on the basis of historically intense chemical control and a high risk for dengue transmission. Ae. aegypti eggs were collected from October 2009 to January 2010 using ovitraps. F₁ adults, emerged from these collections, were exposed to permethrin, deltamethrin and DDT in WHO diagnostic tests and showed high resistance levels to both pyrethroids and DDT. This was consistent with the presence of increased metabolic enzyme activities and target site insensitivity due to kdr mutations. Biochemical assays showed elevated esterase and glutathione S-transferase activities in the six municipalities. The V1016I kdr mutation on the IIS6 domain of the sodium channel gene was present in an overall frequency of 0.80. A second mutation, F1534C on the IIIS6 domain of the same gene was also detected, being the first report of this mutation in Guerrero. The multiple resistance mechanisms present in Ae. aegypti from Guerrero state represent a warning for the efficacy of the pyrethroid usage and consequently for the success of the dengue control program.     

Characterization of sulfated quercetin and epicatechin metabolites

Different monosulfates of quercetin and epicatechin with metabolic interest were obtained by hemisynthesis and characterized regarding their chromatographic behavior and absorption and mass spectra. Three of these compounds were further isolated, and their structures were elucidated by mass spectrometry and (1)H and (13)C nuclear magnetic resonance using one- and two-dimensional techniques (heteronuclear single-quantum coherence and heteronuclear multiple-bond correlation). The calculation of the proton and carbon shifts caused by sulfation allowed for the assignment of the position of the sulfate group in the flavonoids, so that the compounds were identified as quercetin-3'-O-sulfate, quercetin 4'-O-sulfate, and epicatechin 4'-O-sulfate. It was found that sulfation at position 3' induced a large upfield shift in the carbon bearing the sulfate group and downfield displacements of the adjacent carbons, whereas no significant upfield or downfield shifts were observed with respect to the parent flavonoid when sulfation was produced at position 4'.     

Quality and aromatic sensory descriptors (mainly fresh and dry fruit character) of Spanish red wines can be predicted from their aroma-active chemical composition

A satisfactory model explaining quality could be built in a set of 25 high quality Spanish red wines, by aroma-active chemical composition. The quality of the wines was positively correlated with the wine content in fruity esters, acids, enolones, and wood derived compounds, and negatively with phenylacetaldehyde, acetic acid, methional, and 4-ethylphenol. Wine fruitiness was demonstrated to be positively related not only to the wine content on fruity esters and enolones, but to wine volatile fatty acids. Fruitiness is strongly suppressed by 4-ethylphenol, acetic acid, phenylacetaldehyde, and methional, this involved in the perception of dry-fruit notes. Sensory effects were more intense in the presence of β-damascenone and β-ionone. A satisfactory model explaining animal notes could be built. Finally, the vegetal character of this set of wines could be related to the combined effect of dimethylsulfide (DMS), 1-hexanol, and methanethiol.     

Prevalence of antibodies against Toxoplasma gondii among Brazilian white-eared opossums (Didelphis albiventris)

Considering that Toxoplasma gondii is a parasite of global importance which affects several animal species including humans, the current study aimed to investigate the prevalence of antibodies against T. gondii among 72 white-eared opossums (Didelphis albiventris) from Botucatu Municipality (22°53'S 48°26'W), S?o Paulo State, Brazil. The investigation was carried out from January 2008 to December 2009, when the animals had their blood samples collected and subjected to the modified agglutination test (MAT); 12 specimens had brain samples bioassayed in mice. Seroprevalence was 5.5% (n=4) and bioassays were negative. Older animals had higher prevalence of antibodies against T. gondii. Opossums in closer contact with the urban environment are likely more exposed to T. gondii than animals from the sylvatic environment.     

Aluminum speciation in the bulk and rhizospheric soil solution of the species colonizing an abandoned copper mine in Galicia (NW Spain)

Purpose  

The present study was carried out to identify and quantify the aluminum species present in the bulk and rhizospheric soil solution of the spontaneous vegetation colonizing the dump (Calluna vulgaris, Erica cinerea) and slope (C. vulgaris, E. cinerea, Salix atrocinerea) of an abandoned Cu mine in Touro (Galicia, NW Spain).     

Geomorphology and soils distribution under paraglacial conditions in an ice-free area of Admiralty Bay, King George Island, Antarctica

The main pedological, geomorphological and cryogenic features of Keller Peninsula, part of Admiralty Bay, King George Island, Maritime Antarctica, were mapped and quantified with emphasis on the relationship between the ice retreat process, melt-out, landform development and soil distribution. Moraines, protalus, scree slopes, inactive glacial cirques, uplift marine terraces, biogenic landforms, arêtes and Felsenmeer were mapped. Scree slope is the main landform, covering approximately 25% of the peninsula, indicating prominent paraglacial features. Inherited, glacial landforms, such as lateral moraines, highland plateau and exhumed U shaped-valleys, are now being exposed in north Keller by ice shrinkage of former ice protecting cover. Landforms influenced soil formation and stability. Cryosols and Leptosols (WRB) roughly corresponding to Gelisols and Entisols (SSS), respectively, are the most common soil classes, with an overall tendency of absent permafrost in the coastal areas, changing to sporadic permafrost at mid-slope, and discontinuous permafrost with greater altitude and substrate stability.     

Clinical value of carcinoembryonic antigen in mammary neoplasms of bitches

This study aimed at evaluating the behaviour and understanding the diagnostic value of the carcinoembryonic antigen (CEA) in bitches with mammary carcinoma as a tool for monitoring and prognosis of canine cancer patients. Serum samples from 77 bitches were divided into four groups, G1 (n = 21), control group (healthy/neoplasia free bitches); G2 (n = 31), bitches with non‐metastatic mammary carcinoma less than 3 cm; G3 (n = 12), bitches with non‐metastatic mammary carcinoma greater than 3 cm; and, G4 (n = 13) bitches with mammary carcinoma and lymph node metastasis. The marker was dosed once in G1, whereas in G2, G3 and G4, CEA levels were determined before (M0) and 15 days after (M1) mastectomy, using the ELISA kit for humans while reading used ELISYS ONE human. A group of 11 bitches was followed up 45 days after mastectomy (M2). The results for the concentration of markers in blood serum samples at the evaluated times and their relationship with neoplasia biological behaviour and observed clinicopathological changes were evaluated by the Tukey test at 5% significance. The ROC curve was established to find the cut‐off value and calculate the test sensitivity and specificity, the multivariate matching analysis was performed to confirm the association between CEA values and clinicopathological variables. CEA values increased significantly in bitches with mammary carcinoma, metastatic tumours with a diameter larger than 3.0 cm and high grade, compared with healthy ones. In addition, mastectomy reduced the CEA concentration in the blood (P < .05) whereas high CEA levels were associated with unfavourable prognostic factors (P < .05). The biomarker presented good diagnostic value, especially for more aggressive tumours. In conclusion, CEA serum concentrations allowed to follow efficiently the evolution of mammary tumours in bitches, since CEA values increased in bitches with mammary gland tumour and decreased after mastectomy while correlating with prognostic factors such as tumour size, nodal metastasis and histological grade. Further studies are still needed to confirm its diagnostic value for follow‐up of relapse and early metastasis.