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241.
No data have previously been reported on Eurasian perch Perca fluviatilis L. in Lake Varese. In this study, the growth, diet, and reproductive biology of the Eurasian perch population were investigated with the aim of providing information that may serve as a basis for efficient resource management. A total of 240 specimens were caught during the monthly sampling campaign from November 2006 through October 2008. The length-to-weight relationships were W t = 8.4 × 10−3 L t3.10 (males) and W t = 4.1 × 10−3 L t3.36 (females). The parameters for the von Bertalanffy growth function for pooled sexes were L  = 33.17 cm, k = 0.20 year−1, and t 0 = −1.34 year. Perch in Lake Varese spawn from April through May. Sexual maturity is reached when males are 2 years old, in females mostly when they are 3 years old. Relative fecundity (F rel) and absolute fecundity (F abs) were assessed for females. Fecundity values were similar to data reported for other European populations: females of age 2+ F rel = 102,457 ± 12,275, age 3+ F rel = 131,767 ± 5,891, and age 4+ F rel = 131,252 ± 15,555. Perch diet spectrum was wide and somewhat characterized by season. Perch in Lake Varese feed on macroinvertebrates, mainly Chironomidae and Chaoborus, zooplankton, and juvenile rudd Scardinius erythrophthalmus.  相似文献   
242.
Neurologic diseases are common in domestic cats, and infectious agents are suspected to be the primary cause in 30–45% of cases. Among infectious etiologies, those of bacterial origin are only sporadically characterized in the literature, with few of these reports correlating gross and histologic findings with confirmatory bacteriologic identification. Here, we describe bacterial meningitis and meningoencephalomyelitis associated with Pasteurella multocida in 3 domestic cats. Purulent exudate expanding the cerebral meninges was grossly evident in 2 of the cases. In all 3 cases, histologic changes included multifocal suppurative-to-necrosuppurative meningitis and/or meningoencephalomyelitis of variable severity. Intralesional colonies of gram-negative, short rod-shaped to coccobacillary bacteria were evident histologically in only 1 case. P. multocida was confirmed by routine bacteriologic culture in all cases. Based on our cases, we hypothesize that the upper respiratory system serves as the main portal of entry for P. multocida, leading to invasion of the central nervous system and possible systemic hematogenous dissemination. A case series of meningoencephalomyelitis associated with P. multocida infection in cats has not been reported previously, to our knowledge. We also review briefly other causes of meningoencephalomyelitis in cats.  相似文献   
243.
This study verified the effects of feeding frequency on growth, blood metabolites, digestive enzyme activities (alkaline protease, acid protease, amylase and lipase) and proximate composition of Lebranche mullet juveniles. Fish with initial weight of 13.6 ± 0.7 g were distributed in twelve tanks and fed one, three, five and seven times per day to apparent satiation for 60 days. While the final weight of fish fed only once a day attained just 15.4 ± 0.7 g, those fed five or seven times per day reached 54.0 ± 12.1 and 55.9 ± 6.1 g respectively. The feed consumption also increased at high frequencies, but feed efficiency was higher (76.7 ± 11.7%) when mullets were fed three times per day. In general, increasing feeding frequencies also increased blood content of metabolites (total protein, glucose, triglycerides and cholesterol), possibly due to increased intake and absorption of nutrients. The response of digestive enzymes correlated with feeding efficiency, with higher activity in fish fed three or five times per day. Concerning whole‐body proximate composition, no significant difference was observed in protein, but lipid content increased significantly with feed frequency. Based on growth performance and biochemical responses, we recommend feeding Lebranche mullet juveniles three to five times per day.  相似文献   
244.
The octocoral family Alcyoniidae represents a rich source of bioactive substances with intriguing and unique structural features. This review aims to provide an updated overview of the compounds isolated from Alcyoniidae and displaying potential cytotoxic activity. In order to allow a better comparison among the bioactive compounds, we focused on molecules evaluated in vitro by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, by far the most widely used method to analyze cell proliferation and viability. Specifically, we surveyed the last thirty years of research, finding 153 papers reporting on 344 compounds with proven cytotoxicity. The data were organized in tables to provide a ranking of the most active compounds, to be exploited for the selection of the most promising candidates for further screening and pre-clinical evaluation as anti-cancer agents. Specifically, we found that (22S,24S)-24-methyl-22,25-epoxyfurost-5-ene-3β,20β-diol (16), 3β,11-dihydroxy-24-methylene-9,11-secocholestan-5-en-9-one (23), (24S)-ergostane-3β,5α,6β,25 tetraol (146), sinulerectadione (227), sinulerectol C (229), and cladieunicellin I (277) exhibited stronger cytotoxicity than their respective positive control and that their mechanism of action has not yet been further investigated.  相似文献   
245.
After a large screening on sourdough lactic acid bacteria, exopolysaccharide (EPS)-forming strains of Weissella cibaria, Lactobacillus plantarum, and Pediococcus pentosaceus were selected. After 6 days of incubation at 30 degrees C, the synthesis of EPS in MRS-based broth ranged from 5.54 to 7.88 mg mL-1. EPS had an apparent molecular mass of ca. 104 Da. As shown by carbohydrate consumption, the synthesis of EPS was found from sucrose only. Two types of homopolysaccharides were synthesized: glucans simultaneously with growth and fructans after 1 day of incubation. Two protein bands of ca. 180-200 kDa were in situ detected on SDS-PAGE gels incubated with sucrose. PCR products of ca. 220 bp were found for L. plantarum PL9 (100% of identity to putative priming glycosyltransferase of L. plantarum WCFS1) and W. cibaria WC4 (80% of identity to putative glycosyltransferase, epsD, of Bacillus cereus G9241) by using hybrid primers for the priming gtf genes. Degenerated primers DexreuR and DexreuV showed a unique PCR product, and the predicted amino acid sequences were identical for W. cibaria WC4 and L. plantarum PL9. The sequence had similarity with polysaccharide biosynthesis glycosyltransferases. W. cibaria WC4 or L. plantarum LP9 synthesized ca. 2.5 g kg-1 EPS during sourdough fermentation with sucrose added. Compared to the sourdough started with an EPS-negative strain, the sourdough started with W. cibaria WC4 or L. plantarum LP9 increased the viscosity, and the resulting bread had higher specific volume and lower firmness. The synthesis of EPS by selected sourdough lactic acid bacteria could be considered as a useful tool to replace the additives for improving the textural properties of baked goods.  相似文献   
246.
  • ? The spruce bark beetle, Ips typographus, is one of the main European forest pests, and mass trapping is probably the most common strategy applied to reduce its population density. However, the results concerning the effectiveness of this control system are often controversal, and many studies consider only the trapping performance with no attention to the damage reduction.
  • ? During spring-summer 2005, a control program against I. typographus outbreaks was set up in NE Italy. Twenty-four spruce forests heavily infested by I. typographus were studied: six protected by pheromone slot-traps, six by horizontal trap-logs and six by standing trap-logs; six untreated stands were kept as controls. Trap-logs were baited with a pheromone specific to I. typographus and treated with insecticide. Each type of device was tested at high, medium and low density in relation to the number of trees infested during the previous year. New damage occurring in the investigated stands was later monitored for one year.
  • ? Protected forests showed mean damage about 80% lower in 2005 than in 2004, with no statistical difference among traps, trap-logs or standing trap-logs. Instead, unprotected forests (controls) suffered damage to a similar extent in both years. Trapping devices showed no statistical differences among mean captures. Device densities showed similar results in damage reduction and insect trapping.
  • ? The results support the hypothesis that intensive trapping performed at stand level may be useful for protecting forests against I. typographus, locally reducing population density and tree mortality.
  •   相似文献   
    247.
    A survey of the genetic diversity among the major cuban rice cultivars was conducted using isozyme, RAPD and AFLP markers. Polymorphisms were detected for esterases, peroxidases, alcohol dehydrogenases and polyphenoloxidases systems; 21 RAPD primers and four AFLP primer combinations. Heterozygosity arithmetic mean value (Hav(p)), the effective multiplex ratio (EMR) and the marker index (MI), were calculated for isozyme, RAPD and AFLP markers. The mean value of genetic similarity among the different varieties was 0.92 for isozyme, 0.73 for RAPD and 0.58 for AFLP analyses. Thus, AFLP were able to detect polymorphisms with higher efficiency than RAPD (+15%) and isozyme (+34%). Data from the isozyme, RAPD and AFLP analyses were used to compute matrices of genetic similarities. The efficiency of the UPGMA for the estimation of genetic relatedness among varieties was supported by cophenetic correlation coefficients. The resulting values indicated that the distortion level for the estimated similarities was minimal. The correlation coefficients obtained by the Mantel matrix correspondence test, which was used to compare the cophenetic matrices for the different markers, showed that estimated values of genetic relationship given for isozyme and RAPD markers (r = 0.89), as well as for AFLP and RAPD markers (r = 0.82) were properly related. However, AFLP and isozyme data showed only moderate correlation (r = 0.63). Although the genetic variability found among the different cultivars was low, both RAPD and AFLP markers proved to be efficient tools in assessing the genetic diversity of rice genotypes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
    248.
    In this study, we describe what we term a Blue Transition, defined as the passage from fish biomass reduction to recovery in exploited aquatic resources, enabled by aquaculture. A Blue Transition is a key component of emergent “blue” discourses which support that the expansion of aquaculture would relieve pressure on declining capture fisheries, thus contributing to global food security, particularly of the poorest populations. Based on global secondary data and the case of Chile, we explore the evidence of such claim and the implications of a Blue Transition for fisheries and aquaculture development. In 2012, worldwide aquaculture production surpassed wild captures; nevertheless, such turnaround would have not taken place without China's contribution. In Chile, this turnaround occurred in 2014, concurrently with the lowest industrial landings registered since the 1960s (1,227,359 tons). Chile's aquaculture is not relieving wild fisheries or satisfying food demands of the lower income population, in the country or elsewhere. Salmon, the main aquaculture product, is destined mainly to Japan, Russia and United States where, due to its high prices, it is consumed mostly by wealthy consumers. For the case at hand, evidence suggests that a blue transition may be underway but is going in the wrong direction: from what may have been sustainable fisheries management before the 1970s to the overexploited wild fisheries of today.  相似文献   
    249.
    In this paper molecular analysis, physical, technological, and chemical traits were used to estimate the level of variation on five accessions of a locally adapted Sicilian faba bean (Vicia faba L.) landrace named ‘Larga di Leonforte’. DNA analysis was performed using the Amplified Fragment Length Polymorphism (AFLP) molecular marker class and two other faba beans (cv. ‘Aguadulce Samba’—Spain—and landrace ‘Locale di Modica’—Sicily) were used as controls. Although the accessions of ‘Larga di Leonforte’ varied significantly for most of the agronomical and physical traits, this landrace generally had a heavy seed weight, short but large pods, and no more than two seeds per pod. This last characteristic allowed for erect pod angle attitude at maturity. Idratation data showed difference among accessions in seed weight at full hydration and in absorption rate at the very beginning of the hydration process, while any difference among accessions emerged in terms of cooking properties. The six AFLP Eco+3/Mse+3 different primer combinations applied in this research revealed different levels of polymorphism among the faba bean accessions and a total number of 346 amplicons were generated. Around 60% of amplicons displayed a polymorphic pattern among different accessions. Cluster analysis on morphological, technological, chemical and molecular data placed the all five ‘Larga di Leonforte’ accessions into a separated group, and the Sicilian material shares a fairly large amount of similarity with respect to the cultivar ‘Aguadulce Samba’ selected in Spain.  相似文献   
    250.
    In this work, the pro-oxidant behavior of oleuropein (OLP, 1) is characterized in a Fenton-like experiment by means of ESR spectroscopy using the spin trap system DMSO and 4-(pyridyl-1-oxide)-N-tert-butyl nitrone (POBN) in phosphate buffer (PB) solution. Ferrous ions in the absence of hydrogen peroxide cause the formation of the stable nitroxide species 4 and 5 through the intermediate perferryl species. OLP displays its antioxidant activity in vitro blocking the oxidation path that leads to methoxyl radicals hence to the formation of the stable radical species 5. The role of the catechol moiety was proved when the perferryl experiments were repeated in the presence of the dimethylated oleuropein homologue (OLP-Met2, 2). The dual behavior of oleuropein, similar to that ascertained for other catechol and non-catechol natural active species, should provide warnings for its use as nutraceutical or as drug with manifold healing effects.  相似文献   
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