The relationship between the concentration of plasma progesterone (P4) during embryo attachment or at recognition of pregnancy, and that of pregnancy-associated glycoprotein (PAG) was assessed in dairy cows. The outcome of artificial insemination (AI) was classified as positive (AI+), negative (AI?), or late embryonic mortality (EM) by measuring circulating PAG concentrations and by ultrasonography. Based on P4 concentrations at either day 21 or day 15, AI+ and EM cows were classified into ‘low’ (P4 concentrations < mean) and ‘high’ (P4 concentrations > mean) P4 groups. In both experiments, the threshold of P4 concentration between the ‘low’ and ‘high’ groups was approximately 6 ng/mL. PAG concentrations were lower in the ‘low’ group only when P4 concentrations were below the threshold. The study findings suggest that a possible P4 threshold exists below which PAG secretion may be impaired. 相似文献
The aim of this work was to investigate the metabolism of plasma serotonin or 5-hydroxytryptamine (5-HT), an important neurotransmitter, in Fresian dairy cows, a breed of zootechnical interest, using high-performance liquid chromatography with electrochemical detection. The subjects under study were at the stage of early lactation (n = 10; \( {\hbox{mean body weight}} \ 375\pm 50 \ {\hbox{kg}} \); average age of 3 years; body condition score 2.5), bred in a farm at an altitude of 150 m a.s.l. To evaluate animal welfare on this farm, which is closely connected to an animal’s physiological status, tryptophan and cortisol levels (measured by enzyme-linked immunosorbent assay), together with levels of certain blood components [total proteins (TP), albumin, creatinine, glucose (Glu), triglycerides, phospholipids, total cholesterol, and aspartate transaminase, measured by spectrophotometry] were analyzed. The results obtained are discussed in comparison with reference values, taking into account the environmental living conditions. Measured plasma serotonin concentrations, which were lower than values reported for Brown Swiss dairy cows of a comparable age and diet, appeared to be affected by breed, temperature, blood sampling season, and altitude. Additional differences between the levels of plasma tryptophan, the amino acid precursor of serotonin, of the two breeds were comparable. Negative correlations between plasma tryptophan and plasma cortisol levels (r = −0.83, P < 0.005), plasma serotonin and plasma TP levels (r = −0.72, P < 0.05), or Glu levels (r = −0.77, P < 0.05) highlight the existence of a stress condition, which is connected to an energetic deficit related to lactation.
Knowledge about the stand structure and dynamics of subalpine forests is crucial to preserve their multifunctionality. In the present study, we reconstructed the spatiotemporal dynamics of a subalpine Pinus cembra forest in the eastern Italian Alps in response to natural disturbances and forest management. We adopted a concurrent point pattern, dendroecological and growth dominance (GD) analysis. We mapped and measured all trees of Pinus cembra and Larix decidua in a 1?ha plot. We analyzed intra- and interspecific spatial patterns and spatial autocorrelation of tree size and age. We explored establishment dynamics and shifts in competition by analyzing growth suppression/release patterns and GD trends. Results showed a clumped, uneven-aged, multilayered structure where pine was dominant. The synergic action of ecological and human-induced factors is discussed to explain the prevalence of pine over time. Spatial pattern and autocorrelation analyses suggest a different colonization strategy of the two species, in which pine established after small-scale perturbations and experienced a stronger inter- and intra-specific competition. The interruption of tree establishment and shift in GD toward large trees resulting from the lack of forest management are the most important findings of this research. This highlights the importance of an active management to avoid the homogenization of the forest structure that is generally associated with a reduction in biodiversity and protective ability of forests. 相似文献
Microwave heating (MWH) has been recently proposed as a high-performance technique for the remediation of soils contaminated with organic pollutants. However, despite MWH potential advantages, it is scarcely applied due to the lack of full-scale in situ detailed studies. In this work, the in situ MWH applicability for the remediation of hydrocarbon-polluted soils was assessed by means of a specific energy and economic analysis. Essential technical information has also been purchased.
Materials and methods
Energy and economic analysis was performed using data obtained from modelling for which a dedicated equation-based process computer code simulating MWH phenomena was adopted. Elaborations involved the assessment of the influence of soil texture and moisture as well as operating conditions (supplied power and time) on electric field penetration into the soils and soil temperature variation as a function of time and radial distance from the irradiation source.
Results and discussion
Main results reveal that sandy soils are more penetrable by MW irradiation with respect to clayey ones. The soil MW penetrability was also observed to increase with decreasing the soil moisture. This was in turn reflected in the soil temperature profiles. However, the major effect on MWH effectiveness is ascribable by the changing of the operating power. In fact, the use of magnetrons with powers lower than 3 kW does not ensure enough microwave penetration into the soil and, therefore, is not suitable for in situ activities, whereas the application of a power of 6 kW led to a maximum treatable radius of 145 cm. In terms of energy consumption, calculation showed that almost 3 days more are in general required to remediate clayey soils with respect to sandy ones. Consequently, the economic analysis revealed that energy costs for sandy soils are about 3 € t?1 lower than those required for clayey soils. Furthermore, the application of a power of 6 instead of 3 kW results in a higher total energy cost, which, jointly with the higher soil volume treatable, leads to almost equal specific costs.
Conclusions
The comparison of calculated costs with those of other available clean-up technologies for hydrocarbon-contaminated soils shows that very short remediation times and energy costs obtained (18–27 € t?1) make in situ MWH a deliverable alternative to conventional thermal desorption or physical-chemical techniques.
A liquid chromatographic method with online photometric and luminescent detection for the determination of 18 phenolic compounds in wines is reported. Photometric detection is performed at four wavelengths, namely, 256, 280, 320, and 365 nm, using a diode array detection system. The luminescent detection is achieved by means of a postcolumn derivatization reaction of 10 of these compounds with terbium(III) in the presence of synergistic agents, such as ethylenediaminetetraacetic acid (EDTA) and n-octyltriphosphine oxide (TOPO). A micellar medium provided by the surfactants sodium dodecyl sulfate and Triton X-100 was used for the determination of the luminescent chelates at lambdaex 317 and lambdaem 545 nm. The long wavelength emission of lanthanide chelates can minimize interferences from background sample matrix, which usually emit at shorter wavelengths. The analytical features of the photometric and fluorometric methods, such as dynamic ranges of the calibration graphs, detection limits, and precision data, have been obtained. The practical usefulness of the developed methods is demonstrated by the analysis of Spanish and Italian wine samples (red, rosé, oloroso, and white), which were diluted and directly injected into the chromatographic system. The accuracy of both methods was checked by assaying a recovery study, which was performed at three different analyte levels for each type of sample. 相似文献
This paper reports the synthesis and the biological activity of benzoyl arylureas in which the aryl group bears a trifluoromethyl-substitiited alkyl or alkenyl side chain, R. The activity of these compounds has been evaluated on larvae of S. littoralis, A. aegypti, L. decemlineata and on the eggs of T. urticae. In general: (1) the optimum insecticidal activities are achieved when the substituents on the benzoyl moiety, R1, and R2, are 2,6-difluoro, the substituents on the aryl moiety, R3, are 3,5-dichloro and R1, is 4-(? CH?C(CI)CF3); (2) the best acaricidal activity is shown when R1, is 2-CI, R2, and R3, are hydrogen atoms and R1, is 4-(? CH2CH2CH(CI)CF3); (3) the best overall activity is displayed when R1, is 2-CI, R2 is hydrogen, R3 is 3-chloro and R1 is 4-(? CH2CH2CF3). 相似文献
This paper reports the synthesis and insecticidal activities of benzoyl arylureas in which the aryl group bears a polyfluoroalkoxy or (polyfluoroalkoxy)alkoxy side-chain. The activity of these compounds has been evaluated against larvae of S. littoralis, A. aegypti and L. decemlineata. The effects have been studied of varying (a) the substituents, R1 and R2 in the 2-and 6-positions of the benzoyl moiety; (b) the polyfluoroalkoxy chain R1 in the 4-position of the aryl moiety; and (c) the other substituent(s), R3, on this ring. In general, the highest activities were achieved against S. littoralis when R1, R2 = F, R3 = 2-F and R1 = O? CF2CFH? OCF3 or R1 = Cl and R2 = H. R3 = 2-Cl and R1 = O? CF2CFH? OCF3; against A. aegypti when R1, R2 = F. R3 = 3-F and R1 = O? CF2CFH? OCF3 or R1 = Cl and R2 = H. R3 = 3-F and R1 = O? CF2CFH? OCF3; and against L. decemlineata by compounds in which R1 = Cl and R2 = H. R3 = 3. 5-CI and R1 = O? CF2CFH? OCF3, R1, R2 = F, R3 = 3.5-Cl and R1 = O? CF2CFH? OCF2CF3, R1, R2 = F, R3 = 3-CI and R1 = O? CF2CFH? OCF2CF2CF3. The greatest overall insecticidal activities were achieved when R1, R2 = F, R3 = 2-F and R1 = O? CF2CFH? OCF3 and when R1, R2 = F, R3 = 3-Cl and R1 = O? CF2CFH? OCF3. 相似文献
Fusarium corm rot of saffron (Crocus sativus L.), incited by Fusarium oxysporum f. sp. gladioli, causes severe yield losses in Italy. Major symptoms during flowering (October–November) include yellowing and wilting of shoots, basal stem rot and corm rot. Sixty-four isolates of F. oxysporum f. sp. gladioli, obtained from infected saffron crops located in Italy (Abruzzi, Tuscany and Umbria) and in Spain, were characterized by pathogenicity and vegetative compatibility. Chlorate-resistant, nitrate-nonutilizing (nit) mutants were used to determine vegetative compatibility among the isolates of the pathogen with the aim of examining the genetic relatedness among populations from different locations. All the isolates belonged to vegetative compatibility group 0340. Since saffron shares susceptibility to F. oxysporum f. sp. gladioli with other ornamental plants of the Iridaceae (Crocus, Gladiolus, Iris and Ixia), it is likely that a clone of the pathogen (VCG 0340) was introduced with other hosts and is responsible for the disease outbreak observed on saffron in Italy. Alternatively, or additionally, the clone of F. oxysporum f. sp. gladioli causing disease on saffron in other countries may have spread to the saffron fields in Italy through the import and dispersal of infested propagation material. 相似文献
The reproductive performances of silver European eel in term of gonad development and egg production, employing slow‐release implants with the androgen 17‐MT (1 mg) in combination with traditional weekly injection of carp pituitary extract (CPE) was evaluated. Wild female European eels (Anguilla anguilla) underwent a standard induction protocol with CPE and were randomly divided into three groups (N‐group, no implant; Y‐group, with implant; and control, C‐group, no treatment). The results showed that 17‐MT‐treated females (Y‐group) reproduced spontaneously about 6 weeks earlier than the N‐group females with a saving of almost 40% in CPE and time of induction. Concerning artificial induction of maturation in female silver eels, our study demonstrated that they positively respond to androgen exposure also in terms of eggs productivity. Indeed, Y‐group was more productive than N‐group: in Y‐group, 11 eels ensured an eggs production that exceeded 50% of initial body weight (BW), whereas in N‐group only three eels have exceeded this value. The results suggest that 17‐MT should be considered in future protocols for the improvement of the artificial reproduction of female silver European eels. 相似文献