Activation of visual pigments by light and heat

Vision begins with photoisomerization of visual pigments. Thermal energy can complement photon energy to drive photoisomerization, but it also triggers spontaneous pigment activation as noise that interferes with light detection. For half a century, the mechanism underlying this dark noise has remained controversial. We report here a quantitative relation between a pigment's photoactivation energy and its peak-absorption wavelength, λ(max). Using this relation and assuming that pigment activations by light and heat go through the same ground-state isomerization energy barrier, we can predict the relative noise of diverse pigments with multi-vibrational-mode thermal statistics. The agreement between predictions and our measurements strongly suggests that pigment noise arises from canonical isomerization. The predicted high noise for pigments with λ(max) in the infrared presumably explains why they apparently do not exist in nature.     

Effects of root trenching of overstorey Norway spruce (Piceaabies) on growth and biomass of underplanted beech (Fagussylvatica) and Douglas fir (Pseudotsugamenziesii) saplings

In Central Europe, the conversion of pure Norway spruce stands (Picea abies [L.] Karst.) into mixed stands with beech (Fagus silvatica L.) and other species like e.g. Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) is accomplished mainly by underplanting of seedlings beneath the canopy of overstorey spruce trees after partial cutting treatments what means exposure to shade and below-ground root competition by the overstorey to the seedlings. Particularly about the second factor, our knowledge is limited. Therefore, we carried out a below-ground competition exclusion experiment by root trenching and investigated the effects on soil resources, growth, and biomass partitioning of underplanted beech and Douglas fir saplings under target diameter and strip cutting treatments. The exclusion of overstorey root competition by trenching increased the soil water potential in the second year that had a fairly dry growing season and led to significantly higher foliar concentrations of most nutrients, particularly in Douglas fir, indicating an amended nutrient supply. Both improvements were accompanied by an increase in length and diameter increment of the underplanted saplings, appearing in both species only after having surpassed a species-specific threshold light value (Douglas fir 16% of above canopy radiation, beech 22%). We also found significant interactions between trenching and light for specific fine root length and further biomass and morphological parameters. Judged by the much steeper increase in height and diameter growth with increasing light after release from below-ground competition, Douglas fir saplings appeared to be more sensitive to root competition than beech saplings what conforms to older findings for beech. According to our results, a strip cutting seems to be more appropriate than a target diameter cutting treatment to replace a pure spruce stand by a mixed stand with beech and Douglas fir.     

Relationships between native tree species and soil properties in the indigenous forest fragments of the Eastern Arc Mountains of the Taita Hills,Kenya

The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the world due to their high biodiversity of both plant and animal species. This relationship was assessed by using Spearman correlation and principal component analyses (PCA). The results of these analyses should be useful in instituting forest restoration programs that are crucial for the forests. Both the soil and vegetation studied were sampled from 17 subplots in the natural forest fragments of Ngangao (120 ha), Chawia (86 ha) and Mbololo (185 ha). The soil variables measured were: pH, texture, soil nutrients of C, N, Ca, P, K, Mg and Na. In total 36 native tree species from 13 families were identified from the three forest fragments. Ordination results show that axis 1 accounted for 35% and axis 2 for 25% of the total variation in species composition, indicating that the structure of vegetation is related to two major environmental gradients. The correlation analyses of species and soil properties showed that Na and clay particles were the most important determinants of species distribution; pH and soil variables such as C, N, Ca and P also played minor roles. Unexpectedly, some species (e.g. Psychotria petitii) showed positive relationships with Na attributed to possible substitution for K. Relationships with P were both positive (e.g. Craibia zimmermannii) and negative (e.g. Albizia gummifera) with some species, attributable to pH levels. An ANOVA for soil variables showed that there were differences in the Ca content in Mbololo (due to the parent material) and P in Ngangao where a special relationship was observed between some of the species. The presence of gaps accounted for the distribution of seedlings but not for the saplings, whose distribution responded more to factors similar to those to which mature trees respond. Soil-species relationships that were established may be utilized along with soil analyses when choosing native species for restoration.     

Adventitious shoot regeneration from hypocotyl slices of mature apricot (Prunus armeniaca L.) seeds: A feasible alternative for apricot genetic engineering

Adventitious shoot regeneration from hypocotyl slices of mature apricot seeds has been achieved with regeneration percentages of 31.7%, 44.4%, and 46.9% for the cultivars ‘Canino’, ‘Dorada’, and ‘Moniqui’, respectively. Regeneration was significantly affected by the parental origin of the explants (P < 0.05) but not by thidiazuron or 3-indolebutyric acid for any of the three cultivars, at the levels tested. None of the other factors studied (basal medium, 2,4 dichlorophenoxy-acetic acid pulses, dark incubation period, or addition of silver thiosulfate) affected significantly shoot regeneration percentage from ‘Canino’ hypocotyl sections. The effect of paromomycin on regeneration was genotype-dependent and different dose–response curves were obtained for each cultivar. While 40 μM paromomycin completely inhibited regeneration from ‘Canino’ sections, some buds were obtained from ‘Dorada’ and ‘Moniqui’ explants. The two aminoglycoside antibiotics tested, kanamycin and paromomycin, showed differing toxicity on ‘Canino’. A lower concentration of kanamycin (20 μM) than of paromomycin inhibited totally adventitious regeneration from ‘Canino’ explants. Agrobacterium-mediated transformation experiments, with the non-oncogenic strain AGL1 harboring the binary plasmid p35SGUSINT, were performed and GUS assays were carried out after four weeks to determinate stable transformation events. The utilization of paromomycin (10 μM) as the selective agent increased significantly both the number of explants that presented at least one transformation event (P < 0.05) and the number of large area or calli expressing the gus gene (P < 0.001), compared with the addition of kanamycin (10 μM). Moreover, when 10 μM paromomycin was added to the medium some massively transformed explants were observed and a chimerical bud was regenerated.     

Estimating collateral mortality from towed fishing gear

More than 50% of the world's total marine catch (approximately 81 million tonnes) is harvested using towed fishing gears (i.e. Danish seines, dredges and otter and beam trawls). As for all methods, the total fishing mortality of these gears comprises the reported (landed) and unreported catch and other unaccounted, collateral deaths due to (i) avoiding, (ii) escaping, (iii) dropping out of the gear during fishing, (iv) discarding from the vessel, (v) ghost fishing of lost gear, (vi) habitat destruction or subsequent (vii) predation and (viii) infection from any of the above. The inherent poor selectivity of many towed gears, combined with their broad spatial deployment, means that there is considerable potential for cumulative effects of (i)–(viii) listed above on total fishing mortality, and subsequent wide‐scale negative impacts on stocks of important species. In this paper, we develop a strategy for minimizing this unwanted exploitation by reviewing all the primary literature studies that have estimated collateral, unaccounted fishing mortalities and identifying the key causal factors. We located more than 80 relevant published studies (between 1890 and early 2006) that quantified the mortalities of more than 120 species of escaping (26 papers) or discarded (62 papers) bivalves, cephalopods, crustaceans, echinoderms, elasmobranches, reptiles, teleosts and miscellaneous organisms. Seven of these studies also included the estimates of mortalities caused by dropping out of gears, predation and infection [(iii), (vii) and (viii) listed above]. Owing to several key biological (physiology, size and catch volume and composition), environmental (temperature, hypoxia, sea state and availability of light) and technical (gear design, tow duration and speed) factors, catch‐and‐escape or catch‐and‐discarding mechanisms were identified to evoke cumulative negative effects on the health of most organisms. We propose that because the mortalities of discards typically are much greater than escapees, the primary focus of efforts to mitigate unaccounted fishing mortalities should concentrate on the rapid, passive, size and species selection of non‐target organisms from the anterior sections of towed gears during fishing. Once maximum selection has been achieved and demonstrated to cause few mortalities, efforts should be made to modify other operational and/or post‐capture handling procedures that address the key causal factors listed above.     

欧洲饲料生产质量管理

食品安全是西欧消费者担心的主要问题,并且在世界各地得到越来越多的重视。饲料工业,包括其供应商,是食物链的一部分,因此必须对其产品的安全性负责。在这种情况下,可见和透明的质量保证措施就是“生产许可证”。H ACCP系统是用一个通过预料未来问题而提前采取行动来管理整个饲     

Effects of freezing, drying, ultraviolet irradiation, chlorine, and quaternary ammonium treatments on the infectivity of myxospores of Myxobolus cerebralis for Tubifex tubifex

The effects of freezing, drying, ultraviolet irradiation (UV), chlorine, and a quaternary ammonium compound on the infectivity of the myxospore stage of Myxobolus cerebralis (the causative agent of whirling disease) for Tubifex tubifex were examined in a series of laboratory trials. Freezing at either -20 degrees C or -80 degrees C for a period of 7 d or 2 months eliminated infectivity as assessed by the absence of production of the actinospore stage (triactinomyxons [TAMs]) from T. tubifex cultures inoculated with treated myxospores over a 4-5-month period. Myxospores retained infectivity when held in well water at 5 degrees C or 22 degrees C for 7 d and when held at 4 degrees C or 10 degrees C d for 2 months. In contrast, no TAMs were produced from T. tubifex cultures inoculated with myxospores held at 20 degrees C for 2 months. Drying of myxospores eliminated any evidence of infectivity for T. tubifex. Doses of UV from 40 to 480 mJ/cm2 were all effective for inactivating myxospores of M. cerebralis, although a few TAMs were detected in one replicate T. tubifex culture at 240 mJ/cm2 and in one replicate culture at 480 mJ/cm2. Treatments of myxospores with chlorine bleach at active concentrations of at least 500 mg/L for 15 min largely inactivated myxospore infectivity for T. tubifex. Likewise, there was no evidence of TAMs produced by T. tubifex inoculated with myxospores treated with alkyl dimethyl benzyl ammonium chloride (ADBAC) at 1,500 mg/L for 10 min. Treatments of myxospores with 1,000-mg/L ADBAC for 10 min reduced TAM production in T. tubifex cultures sevenfold relative to that in cultures inoculated with an equal number of untreated myxospores. These results indicate that myxospores of M. cerebralis demonstrate a selective rather than broad resistance to selected physical and chemical treatments, and this selective resistance is consistent with conditions that myxospores are likely to experience in nature.     

Diseases with relevance to protection of animals with an example of the musculoskeletal system of dogs

Protection of animals needs major concern in breeding programmes especially if inherited diseases occur which cause pain, suffering and/or damages for the animals. Dogs breeders and people keeping dogs as well as veterinarians should be informed about the etiology on sequels of diseases which cause pain to the animals and from which the animals have to be protected in order to make them more conscious on these problems and to achieve changes in dog breeding programmes. The information system "Inherited Diseases of the Musculoskeletal System of Dogs" should display the already published knowledge about etiology, pathogenesis, appearance, therapy and genetics of these diseases. This information system was built up in such a way that it can be used by students as a learning programme to understand the basic relationships among animal protection, diseases, and dog breeding. The user is also supplied with support for breeding decisions as well as for interpretation of breeding values and genotype probabilities. Additionally, information can be obtained on all in the German Association for Dog Breeding (VDH) represented breeds and breeding clubs. Actions to reduce genetically caused diseases required for members of dog breeding clubs are also available. The information system ist programmed by using HTML (Hyper Text Markup Language). Publication is possible on CD-ROM and on Internet. The supplied hyperlinks allow to make use of other publications on the world wide web related to dog and diseases of dogs.     

Physical characters and antioxidant, sugar, and mineral nutrient contents in fruit from 29 apricot (Prunus armeniaca L.) cultivars and hybrids

Fruit physical and chemical characters of 29 apricot cultivars of Greek and American origin and their hybrids were evaluated using correlation and principal component analysis. A remarkable variation was observed in the total phenol content (0.3-7.4 mg gallic acid equivalent g(-1) FW) and total antioxidant capacity (0.026-1.858 mg ascorbic acid equivalent g(-1) FW), with the American origin cultivars Robada and NJA(2) and the new cultivar Nike exhibiting the greatest values. The cultivar Tomcot and hybrid 467/99 had the highest content of total carotene (37.8 microg beta-carotene equivalent g(-1) FW), which was up to four times greater as compared with the rest of studied genotypes. The dominant sugar in fruit tissue was sucrose, followed second by glucose and third by sorbitol and fructose-inositol. The new cultivars Nike, Niobe, and Neraida contained relatively higher contents of sucrose and total sugars, while Ninfa and P. Tirynthos contained relatively higher contents of K, Ca, and Mg. Correlation analysis suggested that late-harvesting cultivars/hybrids had greater fruit developmental times (r = 0.817) and contained higher sugar (r = 0.704) and less Mg contents (r= -0.742) in fruit tissue. The total antioxidant capacity was better correlated with the total phenol content (r = 0.954) as compared with the total carotenoid content (r = 0.482). Weak correlations were found between the fruit skin color and the antioxidant contents in flesh tissue. Multivariate analysis allowed the grouping of variables, with more important variables being the harvest date, fruit developmental time, skin Chroma, sorbitol, and total sugar, K and Mg contents. Plotting the genotypes in a dendrogram revealed cases of homonymy between parents and hybrids, although independent segregation of the measured traits after hybridization was also found.     

Oxidation of skeletal muscle myofibrillar proteins in oil-in-water emulsions: interaction with lipids and effect of selected phenolic compounds

The effect of selected phenolic compounds, namely, gallic acid, cyanidin-3-glucoside, (+)-epicatechin, chlorogenic acid, genistein and rutin (50 and 200 microM), and alpha-tocopherol (50 microM) against the oxidation of oil-in-water emulsions (37 degrees C/10 days) containing 1% myofibrillar proteins (MPs), was investigated. Emulsions containing 1% bovine serum albumin (BSA) were also prepared for comparative purposes. Protein oxidation was assessed by measuring the loss of natural tryptophan fluorescence and the protein carbonyl gain by using fluorescence spectroscopy. Lipid oxidation was concurrently analyzed by measuring the increase of conjugated dienes (CDs) and hexanal. Proteins inhibited lipid oxidation in oil-in-water emulsions, and MPs showed a more intense antioxidant activity than BSA. MPs were also more resistant to oxidative deterioration than BSA. The different antioxidant capacity of MPs and BSA and their susceptibility to suffer oxidative reactions might be derived from their different amino acid composition and three-dimensional structures. The addition of the phenolic compounds resulted in a variety of effects, including both antioxidant and pro-oxidant effects. Gallic acid, cyanidin-3-glucoside, and genistein were the most efficient inhibitors of lipid and protein oxidation. The chemical structure of the phenolic compounds as well as the nature and conformation of the proteins were greatly influential on the overall effect against oxidative reactions.