Cover Image,Volume 73, Issue 9

The cover image, by Frode Oppedal et al., is based on the Research Article Sea lice infestation levels decrease with deeper ‘snorkel’ barriers in Atlantic salmon sea‐cages, DOI: 10.1002/ps.4560 .

     

Reversible anesthesia in wild marine otters (Lontra felina) using ketamine and medetomidine.

Nine marine otters (Lontra felina) were anesthetized 15 times with a combination of ketamine (5.3 +/- 0.9 [range: 4.5-8.0] mg/kg) and medetomidine (53 - 9 [range: 45-80] microg/kg) i.m. by hand syringe for the placement of radiotransmitters. Times to initial effect and induction period ranged from 1.1 to 5.0 min and 1.8 to 5.4 min, respectively. Minor complications did occur, including mild hypothermia in six otters and severe hypoxemia in one otter. After 34 and 63 min, anesthesia was antagonized with atipamezole (226 +/- 29 [range: 179-265] microg/kg) and all otters recovered within 3.3-26.8 min.     

THE EFFECT OF ANGLE SLICE ACQUISITION ON COMPUTED TOMOGRAPHIC CERVICAL VERTEBRAL COLUMN MORPHOMETRY IN GREAT DANES

Computed tomography (CT) scans can be acquired with the transverse images aligned either parallel to the endplates or perpendicular to the vertebral canal. The purpose of this prospective cross‐sectional study was to determine the effect of angle acquisition on CT morphometric evaluation of the cervical vertebral column of Great Danes with and without cervical spondylomyelopathy. Twenty‐eight Great Danes (13 normal, 15 affected) were sampled. For each dog, a set of CT images was acquired with the transverse slices aligned parallel to the endplates and another one with the transverse images aligned perpendicular to the vertebral canal. For each different set, transverse slices from the cranial, middle, and caudal aspects of the individual vertebral bodies C2‐C7 were measured. Height, width, transverse area, right dorsal to left ventral height (RDLV), and left dorsal to right ventral height (LDRV) were recorded by a single observer at each location. For both affected and control dogs, significant differences between the measurements obtained from the two sets of transverse images were found only at the cranial aspect of the vertebrae (P = 0.005, P < 0.001, P < 0.001, P = 0.005, and P = 0.010 for height, width, area, RDLV, and LDRV, respectively). Measurements for the middle and caudal aspects did not differ. The funnel‐shape morphology of the cervical vertebral foramina in Great Danes with stenosis of their cranial aspect may be responsible for the significant differences found. Considering that the morphometric parameters were significantly affected by CT slice angle in the current study, authors recommend that a standardized scanning protocol be followed when morphometric evaluations using CT are planned.     

Seasonal leaf dynamics in an Amazonian tropical forest

The ecological consequences of climate change for large tropical forests such as the Amazon are likely to be profound. Amazonian forests strongly influence regional and global climates and therefore any changes in forest structure, such as deforestation or die-back, may create positive feedback on externally forced climate change. Monitoring, modelling and managing the impacts of anthropogenic climate change on forest dynamics is therefore an important objective of forest researchers, and one that requires long-term data on changes at the level of community, populations and phenotypes. In this paper we provide the most comprehensive study yet on the seasonal dynamics of various leaf traits: leaf area index (LAI), leaf mortality (LM), leaf biomass (LB), leaf growth rate (LG), and leaf residence time (TR) from 50 experimental plots in a forest site at Belterra, Pará State, Brazil. From this study we estimate annual mean leaf area index (LAI) to be 5.07 m² m⁻² and annual mean leaf dry biomass to be 0.621 kg m⁻². The typical leaf grew at 0.049 kg m⁻² month⁻¹ and remained on the tree for 12.7 months. We compare these results to other similar studies and critically discuss the factors driving leaf demographics in Amazonia.     

Genetic diversity,population structure and key phenotypic traits driving variation within soyabean (Glycine max) collection in Ghana

Soybean [Glycine max (L.) Merrill] is an important oilseed crop worldwide and it has recently become the crop of interest in Ghana. In this study, 142 soybean accessions were genotyped with 34 SSR markers and concurrently evaluated for five quantitative and two qualitative phenotypic traits. Twenty‐nine of the SSR markers were polymorphic with mean allele number of 5.3, polymorphic information content (PIC) of 0.51 and gene diversity of 0.55. Molecular analysis based on unweighted paired group arithmetic mean (UPGMA) clustering and principal coordinate analysis (PCoA) was similar in explaining the extent of diversity within the accessions. Structure analysis placed most of the accessions into two subpopulations with 18 (12.7%) as admixtures. Principal component analysis (PCA) based on phenotypic traits revealed two clusters. Both UPGMA clustering‐based SSR data and PCA from phenotypic data showed similar results. The assembled germplasm is genetically diverse with high variation in flowering and maturity period, and key yield components which could be exploited in developing superior varieties well adapted to Ghana and West Africa.     

Reproductive compatibility studies between wild and cultivated strawberries (Fragaria × ananassa) to obtain “bridge species” for breeding programmes

The Fragaria genus has become relevant due to worldwide economic importance of the octoploid hybrid F. × ananassa. Interspecific hybridizations are widely employed in breeding programmes to introduce useful characteristics from wild species to cultivated varieties, although many reproductive barriers prevent gene flow between species. Hybrid genotypes that can act as a bridge between related wild species and cultivated strawberry could be useful to overcome those barriers. The aim of this work was to obtain interspecific hybrids of Fragaria and to analyse possible reproductive barriers. In the Banco de Germoplasma de Frutilla‐UNT, crossings were carried out among wild species of Fragaria with different ploidy levels and cultivated strawberry. To confirm hybrid condition of genotypes obtained, histological techniques and microsatellite markers were used. When wild species were crossed with cultivated strawberry in both directions, there was low production of achenes, while in crosses between wild species of Fragaria genus, achene production was very high. The percentage of germination of achenes was high when crossed species had the same ploidy level, and very low or null when they presented different ploidy levels. Although pre‐zygotic incompatibility associated to the degree of domestication and postzygotic barriers related to different ploidy levels of the progenitors were detected, new hybrid genotypes of Fragaria were obtained. These new hybrids could be used as “bridge species” in breeding programmes, since preliminary results showed no incompatibility barriers when they were crossed with Duchesnea indica.     

Atmospheric Deposition of Acidifying and Eutrophicating Substances in Dune Slacks

Water, Air, &; Soil Pollution - The atmospheric input of nitrogen and potantial acid, and the composition of the leachate from the topsoil layer are quantified for eight dune slack sites...     

Assessing UAV-collected image overlap influence on computation time and digital surface model accuracy in olive orchards

Addressing the spatial and temporal variability of crops for agricultural management requires intensive and periodical information gathering from the crop fields. Unmanned Aerial Vehicle (UAV) photogrammetry is a quick and affordable method for information collecting; it provides spectral and spatial information when required with the added value of Digital Surface Models (DSMs) that reconstruct the crop structure in 3D using “structure from motion” techniques. In the full process from UAV flights to image analysis, DSM generation is one bottle-neck due to its high processing time. Despite its importance, the optimization of the required forward overlap for saving time in DSM generation has not yet been studied. UAV images were acquired at 50 and 100 m flight altitudes over two olive orchards with the aim of generating DSMs representing the tree crowns. Several DSMs created with different forward laps (in intervals of 5–6% from 58 to 97%) were evaluated in order to determine the optimal generation time according to the accuracy of tree crown measurements computed from each DSM. Based on our results, flying at 100 m altitude and with a 95% forward lap reported the best configuration. From the analysis derived from this configuration, tree volume was estimated with 95% accuracy. In addition, computing time was 85% lower in comparison to the maximum overlap studied (97%). It allowed computing the 3D features of 600 trees in a 3-ha parcel in a highly accurate and quick (a few hours after the UAV flights) manner by using a standard computer.     

Alien and endemic flora at reference and non‐reference sites in Mediterranean‐type streams in Portugal

• 1. A comparison was made between a variety of alien and endemic plant species from 272 aquatic and riparian habitats in Portuguese Mediterranean‐type streams in reference condition — i.e. near‐natural river corridors — and non‐reference condition. The objective was to detect differences in relative proportion and cover between these species groups. The differences in endemic and alien flora from siliceous and calcareous river types were also analysed. Environmental and human disturbance factors were related with the richness and cover of both species groups.
• 2. A total of 568 species were found, of which 44 were alien and 28 were endemic. Alien species were present at 91% of the surveyed locations, and were consistently more widespread at non‐reference sites than at reference ones for both river types, with calcareous sites having a higher invasibility. Endemic species occurred at 45% of the sampling sites and displayed a significantly lower richness and cover than their alien counterparts.
• 3. Alien richness and cover were positively related to direct human disturbance within the river systems, and with floodplain uses such as urban occupation, intensive agriculture, and nutrient inputs. Endemic species also respond to anthropogenic variables, rather than to climatic and geographical ones, with richness and cover increasing as human impacts on fluvial systems and related floodplains decrease.
• 4. Comprehensive control of alien invasive species and the protection of endemic plant populations will require attempts at monitoring ecological river integrity, and the achievement of ‘good ecological status’ — one of the goals of the European Union's Water Framework Directive. Portuguese riparian areas must be managed in such a way as to protect the relatively few preserved riparian habitats by lowering the direct and indirect pressures in fluvial corridors and thus preventing future alien plant invasions.

Copyright © 2006 John Wiley & Sons, Ltd.     

Seed oil bodies from Gevuina avellana and Madia sativa

In this study, oil bodies (OBs) from Gevuina avellana (OBs-G) and Madia sativa (OBs-M) were isolated and characterized. Microscopic inspection revealed that the monolayer on OB-G was thinner compared to that on OB-M. Cytometric profiles regarding size, complexity, and staining for the two OB sources were similar. Fatty acid to protein mass ratio in both OBs was near 29, indicating high lipid enrichment. OBs-G and OBs-M showed a strong electrostatic repulsion over wide ranges of pH (5.5-9.5) and NaCl concentration (0-150 mM). Proteins displaying highly conserved sequences (steroleosins and aquaporins) in the plant kingdom were identified. The presence of oleosins was immunologically revealed using antibodies raised against Arabidopsis thaliana oleosins. OBs-G and OBs-M exhibited no significant cytotoxicity against the cells. This is the first report about the isolation and characterization of OBs-G and OBs-M, and this knowledge could be used for novel applications of these raw materials.