Do mature pine plantations resemble deciduous natural forests regarding understory plant diversity and canopy structure in historically modified landscapes?     

Reyes Tárrega  Leonor Calvo  Ángela Taboada  Elena Marcos  José Antonio Marcos 《European Journal of Forest Research》2011,130(6):949-957

We compared the structure of the arboreal layer and the diversity and species composition of the understory vegetation of three types of mature forest communities: oak (Quercus pyrenaica) and beech (Fagus sylvatica) forests and Scots pine (Pinus sylvestris) plantations. Our main aim was to determine whether differences in these variables existed and were due to the identity of the dominant tree species. We selected four stands or replicates per forest type located geographically close and with relatively similar conditions. We found no differences in the arboreal structure of oak and beech forests, which were characterised by great variability in tree size, while in case of plantations, this variability was lower at both the intra-stand (estimated by the coefficient of variation) and inter-stand (i.e. the four replicates harboured trees of similar sizes) scales. However, the highest variability in the canopy layer of natural forests was not consistently linked to greater understory species richness. Indeed, the lowest plant species richness was found in beech forests, while oak forests harboured the highest value at either the sampling unit (per m²) or stand scales. The greatest negative correlation between plant diversity and the environmental variables measured was found for litter depth, which was the highest in beech forests. The results obtained by the CCA indicated that the four replicates of each forest type clustered together, due to the presence of characteristic species. We concluded that pine plantations did not approach the environmental conditions of native forests, as plantations were characterised by singular understory species composition and low arboreal layer variability, compared to natural woodlands.  相似文献   

Susceptibility of the Mexican bean beetle <Emphasis Type="Italic">Epilachna varivestis</Emphasis> Mulsant (Coleoptera: Coccinellidae) to endemic isolates of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae)     

Jaime A. Ocampo-Hernández  Patricia Tamez-Guerra  Samuel Pineda  Fernando Tamayo-Mejía  Ariel Guzmán-Franco  José I. Figueroa de la Rosa  Ana Mabel Martínez 《Journal of pest science》2011,84(4):471-477

Entomopathogenic fungi represent excellent candidates for biological insecticides. Among the many entomopathogenic fungi, Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) is one of the most promising species. Here, we report the results of infection studies performed using four B. bassiana native isolates (Bb37, Bb38, Bb40, and Bb45) compared with the commercial product Mycotrol^® (strain GHA) on adult Mexican bean beetle Epilachna varivestis Mulsant (Coleoptera: Coccinellidae), one of the most important pests of bean production in Mexico. First, single concentration (1 × 10⁸ conidia mL^?1) assays were carried out using all isolates applied using an immersion method. Examinations at 10 days after inoculation indicated that isolates Bb37, Bb38, and Bb40 significantly reduced adult survival, causing 60–75% mortality compared to the commercial strain GHA (33%) and control (29%). Second, using two selected isolates (Bb37 and Bb40), the mean lethal concentration values (LC₅₀) were estimated for third instar larvae and adult E. varivestis. The LC₅₀ values for Bb37 and Bb40 isolates decreased 5.26-fold and 3.19-fold, respectively, in third instars compared with adults. However, such difference for Bb40 isolate was not significant. Finally, an experiment, to compare the median survival time (MST) values between third instar and adult E. varivestis, was conducted using Bb37 and Bb40 at 1 × 10⁹ conidia mL^?1. MST values were significantly reduced against larvae (87 and 100 h) compared with adults (130 and 134 h) by Bb37 and Bb40, respectively. We conclude that native isolates of B. bassiana represent an important alternative for the control of E. varivestis. However, to demonstrate its effectiveness under field conditions, detailed studies are needed.  相似文献   

The toxicity of selected acaricides against five stored product mites under laboratory assay     

Jitka Stará  Marta Nesvorná  Jan Hubert 《Journal of pest science》2011,84(3):387-391

In laboratory tests, the toxicity of acaricides targeted against house dust mites was tested on five species of stored product mites (Acarus siro, Aleuroglyphus ovatus, Carpoglyphus lactis, Lepidoglyphus destructor, and Tyroborus lini). The formulations of benzyl-benzoate, benzyl-benzoate/permethrin/pyriproxyfen, and neem were diluted in water and applied to filter paper in an unventilated chamber. The mortality of mites was observed after 24 h of exposure to acaricide-impregnated filter paper. All of the tested acaricides were toxic to all of the mite species. There were significant differences in mortality among the species and the acaricides. Benzyl-benzoate/permethrin/pyriproxyfen was the most effective, followed by benzyl-benzoate and neem. L. destructor (LD₅₀ 0.01–0.11 μg) was the most sensitive mite species, followed by A. siro (LD₅₀ 0.04–0.12 μg), T. lini (LD₅₀ 2–21 μg), A. ovatus (LD₅₀ 3–18 μg), and C. lactis (LD₅₀ 4–64 μg). Based on the highly toxic effects of the tested acaricides against the stored product mites, the acaricides should be considered as a potential tool in the control of stored product mites, although next screening is necessary.  相似文献   

Ecology and distribution of Armillaria species in Norway     

N. Keča  H. Solheim 《Forest Pathology》2011,41(2):120-132

The occurence of Armillaria species was assessed in Norway, enabling the northern‐most distribution of this genus to be determined in Europe. Four Armillaria species were found in Norway. Armillaria borealis was the most common species occurring on woody vegetation to the permafrost zone (ca. 69°N). Armillaria cepistipes was present in southern and central Norway, but was not found further than 66°N. Armillaria solidipes and Armillaria gallica were rare, found at only one locality each; 59°40′ and 59°32′, respectively. Armillaria species were found on 14 hosts, but there was no significant difference between occurrence of A. borealis and A. cepistipes on declining and dead trees. Phylogenetic analyses separated each species into separate clades. All isolates of A. borealis, except one, and most isolates of A. solidipes were in separate clades. However, a subclade within the A. borealis clade was formed of two A. ostoyae and one A. borealis isolates. Two small A. cepistipes genets were found in a declining oak stand.  相似文献   

Resveratrol oligomers isolated from Carex species inhibit growth of human colon tumorigenic cells mediated by cell cycle arrest     

González-Sarrías A  Gromek S  Niesen D  Seeram NP  Henry GE 《Journal of agricultural and food chemistry》2011,59(16):8632-8638

Research has shown that members of the Carex genus produce biologically active stilbenoids including resveratrol oligomers. This is of great interest to the nutraceutical industry given that resveratrol, a constituent of grape and red wine, has attracted immense research attention due to its potential human health benefits. In the current study, five resveratrol oligomers (isolated from Carex folliculata and Carex gynandra ), along with resveratrol, were evaluated for antiproliferative effects against human colon cancer (HCT-116, HT-29, Caco-2) and normal human colon (CCD-18Co) cells. The resveratrol oligomers included one dimer, two trimers, and two tetramers: pallidol (1); α-viniferin (2) and trans-miyabenol C (3); and kobophenols A (4) and B (5), respectively. Although not cytotoxic, the resveratrol oligomers (1-5), as well as resveratrol, inhibited growth of the human colon cancer cells. Among the six stilbenoids, α-viniferin (2) was most active against the colon cancer cells with IC(50) values of 6-32 μM (>2-fold compared to normal colon cells). Moreover, α-viniferin (at 20 μM) did not induce apoptosis but arrested cell cycle (in the S-phase) for the colon cancer but not the normal colon cells. This study adds to the growing body of knowledge supporting the anticancer effects of resveratrol and its oligomers. Furthermore, Carex species should be investigated for their nutraceutical potential given that they produce biologically active stilbenoids such as α-viniferin.  相似文献   

Effect of aging on lees and of three different dry yeast derivative products on Verdejo white wine composition and sensorial characteristics     

Del Barrio-Galán R  Pérez-Magariño S  Ortega-Heras M  Williams P  Doco T 《Journal of agricultural and food chemistry》2011,59(23):12433-12442

A study was made of the effect of aging on lees and of three different commercial yeast derivative products of different composition and degree of purification on the phenolic compounds, color, proteins, polysaccharides, and sensorial characteristics of white wines. The results obtained showed that the lees and yeast derivative products can interact or adsorb some of the phenolic compounds present in wines, reducing their concentration. This reduction depends on the treatment applied, the phenolic compound analyzed, and the stage of vinification or aging process. The use of lees and yeast derivative products can reduce the color intensity and the browning of the wines immediately following treatment. The monosaccharide and polysaccharide content of yeast derivative products depends on the manufacturing process and degree of purification of the product, both of which have an influence on wine treatments. After 6 months in the bottle, both the aging on lees and the treatment with commercial yeast derivative products gave rise to wines with better sensorial characteristics than in the case of the control wines.  相似文献   

Congenital diaphragmatic eventration in two closely related British Shorthair cats     

Gombač M  Vrecl M  Svara T 《Journal of Feline Medicine and Surgery》2011,13(4):276-279

Two closely related British Shorthair cats, which died after surgery performed in the dorsal position, were presented for dissection. In both, a thin, flaccid, enlarged transparent tendinous diaphragmatic portion protruded cranially into the thoracic cavity, forming a cupola in which left, right medial and quadrate hepatic lobes were encased in both cats and the stomach in one cat. Microscopically, no muscle fibres were observed in the membrane, but numerous hepatocytes and bile ducts were incorporated in its central part. The anomaly was diagnosed as a congenital diaphragmatic eventration.  相似文献   

Hepatic immune response in calves during acute subclinical infection with bovine viral diarrhoea virus type 1     

Risalde MA  Gómez-Villamandos JC  Pedrera M  Molina V  Cerón JJ  Martínez-Subiela S  Sánchez-Cordón PJ 《Veterinary journal (London, England : 1997)》2011,190(2):e110-e116

Eight colostrum-deprived calves aged 8-12 weeks were inoculated intranasally with a non-cytopathic strain of bovine viral diarrhoea virus (BVDV) genotype-1 and the effects on the hepatic immune response were studied. Two calves were sacrificed at each of 3, 6, 9 and 14 days post-inoculation (dpi) and two uninoculated animals were used as negative controls. BVDV was detected in hepatic macrophages and monocytes from 3 to 14dpi and in Küpffer cells (KCs) from 6 to 14dpi. Increases in the numbers of MAC387(+) KCs and monocytes, but not interstitial macrophages, differentiated by morphological features, were evident in the liver following inoculation with BVDV. There was a substantial increase in the number of monocytes positive for tumour necrosis factor (TNF)-α, but only small increases in the numbers of TNF-α(+) KCs and interstitial macrophages and interleukin (IL)-6(+) monocytes, KCs and interstitial macrophages. There was an increase in the number of interstitial CD3(+) T lymphocytes in the liver, but no substantial changes in the numbers of circulating CD3(+) T lymphocytes, interstitial or circulating CD4(+) or CD8(+) T lymphocytes, or CD79αcy(+) B lymphocytes. Serum haptoglobin and serum amyloid A increased transiently at 12dpi. Upregulation of some pro-inflammatory cytokines by hepatic macrophages is evident in subclinical acute BVDV type 1 infection in calves.  相似文献   

Clinical evaluation of serum alcohol dehydrogenase activity in horses with acute intestinal obstruction     

Naglaa Abdel Megid Gomaa BVSc  MVSc  Gábor Köller Dr rer nat  Gerald Fritz Schusser Dr vet med  DECEIM 《Journal of Veterinary Emergency and Critical Care》2011,21(3):242-252

Objectives – To measure serum alcohol dehydrogenase (ADH) activity in horses with acute intestinal obstruction and to determine the diagnostic and prognostic utility of this analyte. Design – Prospective observational study. Setting – University Veterinary Hospital. Animals – Thirty healthy horses (control group) and 77 horses with acute intestinal obstruction, including 36 horses with nonstrangulating obstruction (23 with left ventral colon impaction and 13 with left dorsal displacement [G1], 22 with small intestinal strangulation [G2], and 19 with colon torsion [G3]). Interventions – Serum ADH activity was assayed spectrophotometerically in all horses. Serum lactate concentration and hepatic enzyme (aspartate aminotransferase, gamma‐glutamyl transferase, glutamate dehydrogenase) activities were measured using an automatic analyzer. Measurements and Main Results – The median [interquartile range] serum ADH activity in healthy horses was 10.5 [8.7 – 11 U/L]. ADH activity was significantly increased (P<0.05) in G1=16.5 [13.8 – 18 U/L], G2=40 [20 – 74.9 U/L], and G3=63.2 [40 – 78 U/L] compared with healthy controls. Aspartate aminotransferase and glutamate dehydrogenase activities were also significantly increased in G3 in comparison with controls. ADH activity was correlated with serum lactate concentration in G1 and G3, respectively (P<0.01, r=0.55 and 0.8). Other liver enzymes did not show any significant correlation with lactate. ADH activity was directly related to the probability of strangulation; odds ratio=1.11. ADH activity >20 U/L had 80.6% specificity and 80.5% sensitivity for discriminating horses with strangulating obstruction. Twelve horses euthanized before surgery were excluded from the outcome analysis. Increasing ADH activity was associated with nonsurvival; odds ratio=1.03. ADH activity <80 U/L had 94.44% specificity and 66.67% sensitivity for survival. Conclusion – Serum ADH activity may be a useful clinical parameter in detecting intestinal strangulation in horses and may provide some prognostic value in horses with acute intestinal obstruction.  相似文献   

Management, breeding, and health records from a captive colony of pekin robins (Leiothrix lutea), 2001 - 2010     

da Cruz CE  de Oliveira LG  Boabaid FM  Zimermann FC  Stein G  Marks F  Cerva C  Lieberknecht C  Canal CW  Driemeier D 《Journal of zoo and wildlife medicine》2011,42(3):451-459

Pekin robins (Leiothrix lutea) were once the most widely kept softbills in captivity. As a result of the Convention on the International Trade of Endangered Species of Fauna and Flora (CITES-1997), the worldwide trade of wild-caught pekin robins has been prohibited due to the depletion of native populations of this species. In Brazil, as in other countries, pekin robins imported prior to the enactment of the CITES have disappeared from aviaries because the end of the birds' natural life span has passed, and only very few captive-bred pekin robins now exist. While captive propagation fails to address the primary causes of wild bird population decline, it might help the recovery of populations of this species. This article presents records made over a 10-yr period of a captive colony of pekin robins. Emphasis is placed on the management of the flock, the ailments affecting the birds, and the findings associated with bird losses. The main causes of bird losses included rearing management failures and age-related disorders.  相似文献