New Trichothecenes Isolated from the Marine Algicolous Fungus Trichoderma brevicompactum

Eight trichothecenes, including four new compounds 1–4 and four known entities 5–8, together with one known cyclonerane (9) were isolated from the solid-state fermentation of Trichoderma brevicompactum NTU439 isolated from the marine alga Mastophora rosea. The structures of 1–9 were determined by 1D/2D NMR (nuclear magnetic resonance), MS (mass spectrometry), and IR (infrared spectroscopy) spectroscopic data. All of the compounds were evaluated for cytotoxic activity against HCT-116, PC-3, and SK-Hep-1 cancer cells by the SRB assay, and compound 8 showed promising cytotoxic activity against all three cancer cell lines with the IC₅₀ values of 3.3 ± 0.3, 5.3 ± 0.3, and 1.8 ± 0.8 μM, respectively. Compounds 1–2, 4–6, and 7–8 potently inhibited LPS-induced NO production, and compounds 5 and 8 showed markedly inhibited gelatinolysis of MMP-9 in S1 protein-stimulated THP-1 monocytes.     

The bacterial flora in the teat duct of ewes can protect against and can cause mastitis

We studied the possible effects of bacterial populations within the teat duct, in the pathogenesis of ovine mastitis. In experiment I, 32 ewes were allocated into group A (ewes from which we isolated (+++ growth) coagulase-negative staphylococci), B (ewes from whose duct we isolated (+ growth) coagulase-negative staphylococci) or C (ewes from which we isolated Bacillus spp.) and subdivided into A1, B1, C1 (n=4; challenged by deposition of 1.250 cfu of Mannheimia haemolytica into the teat duct) or A2, B2, C2 (n=4; used as uninoculated controls); group D (n=8) contained ewes with no bacteria in their teat ducts and were challenged as above. There were less bacteriological isolations of flora (P = 0.018) and challenge (P<0.05) organisms from A1 than from A2 and D ewes; the severity of pathological findings in A1 (summed up score: 27) ewes was smaller than in D (summed up score: 36) ewes (P = 0.038). No such findings were evident with B1 or C1 ewes (P>0.4). In experiment II, ewes (groups E and F, n=6) from whose duct we isolated coagulase-negative staphylococci (+ growth) were used; in group G (n=6) ewes with no bacteria in their teat ducts were included. Teat chapping was applied in E and G ewes. All E ewes developed acute clinical mastitis within 24 h after teat chapping, although we had carried out no challenge; there were more bacteriological isolations of flora organisms from E than from F and G ewes (P < 0.001); the severity of pathological findings in E (score: 28) was greater than in F (score: 3) or G (score: 14) ewes. In experiment III, eight ewes with no bacteria in their teat ducts were allocated into group H or I (n=4) and challenged into the teat (group H) or into the gland (group I) with 10(6) cfu of a Staphylococcus simulans recovered from the teat duct of a group E ewe. Group H ewes developed transiently clinical followed by subclinical mastitis (based on bacteriological and cytological evidence), whilst group I ewes developed severe clinical disease. We conclude that staphylococcal flora present in high numbers within the teat duct of ewes can afford some protection against invading microorganisms. However with impeded defence mechanisms of the teat, the same flora may invade the mammary parenchyma and cause clinical mastitis.     

Purification and characterization of the fimbria F18ac (2134P) isolated from enterotoxigenic Escherichia coli (ETEC)

The adhesin F18ac purified on Sepharose CL 4B column chromatography and SDS-PAGE stained with Coomassie Blue and Western blotting using specific anti-F18ac serum presented one band of approximately 17kDa. Gold immunolabeling revealed that the adhesin F18ac has a fimbrial structure on the bacterial surface. The first 27 amino acid residues of the N-terminal portion of the adhesin F18ac, showed 92.5% homology (25 amino acids) with the F107 (F18ab) fimbriae.     

Observation of backward pulse propagation through a medium with a negative group velocity

The nature of pulse propagation through a material with a negative value of the group velocity has been mysterious, as simple models seem to predict that pulses will propagate "backward" through such a material. Using an erbium-doped optical fiber and measuring the time evolution of the pulse intensity at many points within the fiber, we demonstrate that the peak of the pulse does propagate backward inside the fiber, even though the energy flow is always in the forward direction.     

Spectrophotometric methods to determine carbohydrates in soil

Two common spectrophotometric procedures for determining neutral carbohydrates—the phenol-sulfuric acid and anthrone methods were evaluated for soil analysis. The phenol-sulfuric acid procedure gives results comparable to those obtained by gas-liquid chromatography, and is applicable to a variety of soil types. Prior removal of interfering substances by anion and cation exchange is required. Glucose is recommended as the spectrophotometric reference standard. The anthrone method is not satisfactory under the conditions employed.     

Chondroprotective role of sesamol by inhibiting MMPs expression via retaining NF-κB signaling in activated SW1353 cells

Overexpression of matrix metalloproteinases (MMPs) is a major pathological factor causing cartilage destruction in osteoarthritis (OA). This study aimed to investigate the effects and mechanisms of sesamol on expression of MMPs in activated chondrosarcoma cells. Sesamol significantly attenuated TNF-α- and IL-1β-induced gelatinolysis and expression of MMP-9 in a concentration-dependent manner in SW1353 cells. Additionally, both MMP-1 and -13 stimulated by PMA were inhibited by sesamol. On the other hand, the NF-κB signaling activation through IκB-α degradation was restored by sesamol under TNF-α or PMA stimulation. Furthermore, this bioactive compound exerted the reduction on phosphorylation of ERK1/2 or p38 MAPKs after either PMA or IL-1β stimulation. This study also evaluated whether sesamol down-regulates MMP expression in the joint cartilage of monosodium iodoacetate (MIA)-induced OA in rats. Sesamol prevented the expression of MMP-1 and -9 in the cartilage of MIA-induced OA in rats. The results of this study demonstrate that sesamol inhibits cytokine- or PMA-induced MMPs expression through the signal pathways of either NF-κB or ERK/p38 MAPKs down-regulation. This study also showed that sesamol attenuates destructive factor expression in vivo, providing a potential strategy for the chondroprotective therapy in OA.     

Migratory behaviour and range in Atlantic cod: inference from a century of tagging

A century of tagging experiments on 174 Atlantic cod (Gadus morhua) groups is reviewed and the frequency and spatial distribution of four migratory behaviours documented. Of all cod groups, 41% were categorized as sedentary, 18% as accurate homers, 20% as inaccurate homers and 20% as dispersers (ranging over large areas without recognizable return migrations). All behaviours occurred over the full spatial range of cod. Coastal groups did not differ significantly from offshore (shelf) groups in the relative frequency of migratory behaviours. However, the north‐east Atlantic had more sedentary and accurate homing groups than did the north‐west Atlantic, which had more dispersing groups. Overall, sedentary cod groups had lower maximum historical biomass than did other groups, confirming that migration/dispersal begets abundance. Maximum historical biomass was strongly related to the area occupied [log (biomass, tonnes)] = 1.58 log (range, km²) + 1.529; r² = 0.9), irrespective of migratory type (for 23 major groups a total of 22 million tonnes over 3.3 million km² with an average density of 7 tonnes km^?2). Historical densities were not related to area occupied, although all large groups exhibited high densities (10–12 tonnes km^?2 ; smaller groups had a wide range of density). The four migratory strategies in cod enable entrainment by diverse physical, oceanographic and biological ecosystem properties, and is key to cod success in the North Atlantic.     

Shelf‐edge reefs as priority areas for conservation of reef fish diversity in the tropical Atlantic

• 1. Data from fishing surveys employing bottom long‐lines were analysed to characterize the diversity, assemblages and distribution patterns of demersal fish along the Brazilian outer shelf and upper slope, between latitudes 13°S and 22°S.
• 2. Non‐metric multi‐dimensional scaling (MDS) and cluster analysis indicate three distinct species assemblages separated primarily by depth (the 200 m isobath) and secondarily by latitude (19°S), suggesting a continual transition along the depth and latitudinal gradients in the study area. Species richness was negatively correlated with depth, but with no clear relationship with latitude.
• 3. Results suggest the existence of reef formations on the shelf‐edge zone (40–200 m) and slope down to 500 m depth off the eastern Brazilian coast. More than 75% of the catches recorded were reef fish species from the families Serranidae, Lutjanidae, Malacanthidae, Muraenidae, Sparidae, Balistidae, Carangidae, Haemulidae, Scorpaenidae and Priacanthidae.
• 4. The maximum depth of occurrence for 20 reef species was extended from limits previously recorded.
• 5. The findings reinforce the hypothesis of a faunal corridor for species associated with deep reef formations along the shelf‐edge zone (40–200 m), in the South American continental margin, connecting the south‐western Atlantic and the Caribbean provinces.
• 6. The shelf‐edge reefs support important multi‐species fisheries and harbour critical habitats for the life cycle of many reef fish species, including spawning aggregation sites that are extremely vulnerable to human pressures, such as intensive fishing, shipping and offshore oil and gas exploitation; all activities currently expanding off the Brazilian coast.
• 7. Results reveal the biological importance of deep shelf‐edge reefs as a critical ecological area. Despite their importance, shelf edge reefs are not currently included in any marine protected area network in the tropical south‐western Atlantic. There is now an urgent need to enhance knowledge, implement adequate management strategies and consider these deeper habitats as priority areas for conservation. Copyright © 2011 John Wiley & Sons, Ltd.

     

How behavioural studies contribute to the species problem: a piscine perspective

During the ascendency of ethology, the study of animal behaviour contributed to taxonomic and phyletic issues, but the approach faded in parallel with the waning of systematic studies in general. Systematics and particularly phylogeny has experienced a resurgence with the advent of molecular tools. The understanding of behavioural evolution has benefited from molecular phylogenies. Behaviour's reciprocal contribution, however, currently lies chiefly in resolving the validity of species designation of allopatric species and in potentially helping in the overall classification of species. I review and evaluate the experimental methods favoured in seeking behavioural isolating mechanisms, and the challenge to the species concept when gene trees and species trees disagree. The dynamic situation in the Great Lakes of Africa offers under‐exploited opportunities to test whether behavioural isolating mechanisms evolve in the absence of secondary contact. Given that behaviour is more immediately responsive to changes in the physical and biological environment, behaviour may be the single most salient adaptive feature in speciation events. The species concept is viewed as a fuzzy but nonetheless useful set.     

Studies on the pathogenesis of bovine ephemeral fever in sentinel cattle. I. Virology and serology

Twenty-two sentinel cattle were observed daily during an outbreak of ephemeral fever on a dairy farm in eastern Australia in the summer of 1981–192. Of the 22 cattle, 9 developed clinical ephemeral fever. None developed sub-clinical infection. The pattern of the epidemic was a single index case followed 10 days later by the main epidemic wave which lasted for 7 days. This wave stopped when there were still 14 uninfected susceptible animals remaining in the sentinel group, and when biting flies were very active. Ten isolations of bovine ephemeral fever virus were made in Aedes albopictus tissue cultures from the blood of 5 clinical cases. One hundred and twelve isolations of CSIRO Village virus and one each of Kimberley and Akabane viruses were also made from various members of the sentinel group. There was serological evidence that infections with Tibrogargan, Tinaroo and Aino viruses also occurred in 6 cattle in the observation period. The 13 cattle undergoing a sub-clinical viraemia with CSIRO Village virus, Tibrogargan, Kimberley, Akabane or Aino viruses at the time of the main outbreak, appeared to be temporarily protected against ephemeral fever. However, 9 of the 11 still remaining in the herd were susceptible in a subsequent outbreak of ephemeral fever 2 years later. Evidence is presented that subclinical infections with other arboviruses may limit an ephemeral fever epidemic by providing temporary protection by interference.