Genetic basis of species differentiation between <Emphasis Type="Italic">Coffea liberica</Emphasis> Hiern and <Emphasis Type="Italic">C. canephora</Emphasis> Pierre: Analysis of an interspecific cross

The phenotypic and genetic differentiation between the two related Coffea species (C. liberica Hiern and C. canephora Pierre) was examined. These species differed markedly in terms of leaf, inflorescence, fruit and seed characters. A genetic map of the interspecific cross Coffea liberica × C. canephora was constructed on the basis of 72 BC1 hybrids. Eighty-three AFLP markers, four inter simple sequence repeats (ISSR) and five microsatellites corresponding to Coffea liberica species-specific markers were mapped into 16 linkage groups. The total length of the map was 1502.5 cM, with an average of 16.3 cM between markers and an estimated genome coverage of 81%. The two species were evaluated relative to 16 quantitative traits and found to be significantly different for 15 of them. Eight QTLs were detected, associated with variations in petiole length, leaf area, number of flowers per inflorescence, fruit shape, fruit disc diameter, seed shape and seed length. Results on segregation distortion and the under-representation of particular markers were interpreted in terms of genome differentiation. The implications for the introgression of QTLs involved in advantageous morphological traits (number of flowers per inflorescence, fruit and seed shape) are discussed.     

Patch-occupancy models indicate human activity as major determinant of forest elephant Loxodonta cyclotis seasonal distribution in an industrial corridor in Gabon

The importance of human activity and ecological features in influencing African forest elephant ranging behaviour was investigated in the Rabi-Ndogo corridor of the Gamba Complex of Protected Areas in southwest Gabon. Locations in a wide geographical area with a range of environmental variables were selected for patch-occupancy surveys using elephant dung to assess seasonal presence and absence of elephants. Patch-occupancy procedures allowed for covariate modelling evaluating hypotheses for both occupancy in relation to human activity and ecological features, and detection probability in relation to vegetation density. The best fitting models for old and fresh dung data sets indicate that (1) detection probability for elephant dung is negatively related to the relative density of the vegetation, and (2) human activity, such as presence and infrastructure, are more closely associated with elephant distribution patterns than are ecological features, such as the presence of wetlands and preferred fresh fruit. Our findings emphasize the sensitivity of elephants to human disturbance, in this case infrastructure development associated with gas and oil production. Patch-occupancy methodology offers a viable alternative to current transect protocols for monitoring programs with multiple covariates.     

Primary peri-aortic hemangiosarcoma in a dog

A 10-year-old intact male Norwich terrier dog was evaluated for progressive, intermittent increased respiratory effort. Thoracic radiographs, ultrasonography, and computed tomography were used to identify a caudodorsal thoracic extrapulmonary mass and the presence of pulmonary metastasis. Blood transfusion and stabilization measures were not successful and the patient died. Necropsy confirmed the origin of the mass to be the adventitial layer of the aorta and determined it to be hemangiosarcoma. This is a rare site for the primary lesion.     

Evaluation of the California Mastitis Test as a precalving treatment selection tool for Holstein heifers

The objective of this study was to evaluate the California Mastitis Test (CMT) and a portable electrical conductivity meter for diagnosing precalving intramammary infection (IMI) in Holstein heifers. A total of 428 dairy heifers from 23 dairy herds were enrolled between 6 and 12 days before the expected calving date from June 2002 to June 2003. Mammary secretions were tested by both diagnostic methods and by bacterial culture for evidence of IMI. California Mastitis Test was considered negative if the score was negative, trace or 1 and was considered positive otherwise. Two cut-off points were evaluated for milk electrical conductivity (>5 and >6.5 mS/cm). From this study, an overall proportion of 69% of heifers had precalving IMI and the overall heifer prevalence of major pathogen IMI was 16.8%. At the quarter level, sensitivity and specificity of CMT (68.9% and 68.4%, respectively) and milk conductivity >5 mS/cm (41.0% and 65.2%, respectively) or >6.5 mS/cm (25.2% and 83.3%, respectively) to identify all IMI were low. However, the heifer level sensitivity and specificity of CMT for major pathogens were 91.0% (81.5-96.6) and 27.5% (22.8-32.6), respectively. Using a cut-off point of 5 mS/cm, the heifer level sensitivity and specificity for major pathogens was 68.7% (56.2-79.4) and 44.1% (38.7-49.6), respectively. A conductivity cut-off value of 6.5 mS/cm decreased the sensitivity and increased the specificity to 53.7% (41.1-66.0) and 59.5% (54.0-64.8), respectively. California Mastitis Test and milk electrical conductivity are not good predictors of major pathogen IMI in heifers during the last 2 weeks before calving. However, the negative predictive values at quarter or heifer level were high and the heifer false negative rate was 6-14% using CMT or conductivity, respectively. Therefore, these measures could be useful for screening out heifers or quarters that are unlikely to have a major pathogen IMI.     

Performing a three-step process for conversion of chitosan to its oligomers using a unique bipolar membrane electrodialysis system

Chitosan, a linear polysaccharide composed of beta-1,4 linked d-glucosamine residues, can be depolymerized into oligomers by enzymatic reaction with chitosanase. Recently, bipolar membrane electrodialysis (BMED) has been used for chitosan solubilization and for terminating the enzymatic reaction by action of electrogenerated acid and base, respectively. The aim of the present study was to test a complete "3-in-1" process using a three-compartment BMED configuration to perform simultaneously the solubilization of chitosan, the inactivation of chitosanase, and the demineralization of the oligomers. In addition, the BMED process was compared to a conventional process using chemical acid and base. The BMED method was found to be as effective as the conventional method for solubilizing the chitosan and for inactivating the chitosanase. Furthermore, the use of BMED allowed a demineralization rate of 53% of the chito-oligomer solution in the diluate compartment. A global process of chitosan hydrolysis into its oligomers using a BMED system was proposed. This technology has great potential for industrial application in chitosan oligomer preparation, because it is convenient and ecological and it produces chito-oligomers with a lower mineral content compared with the conventional method.     

Characterization and quantification of grape variety by means of shikimic acid concentration and protein fingerprint in still white wines

Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines previously dialyzed, combined with shikimic acid concentration and multivariate analysis, were used for the determination of grape variety composition of a still white wine. Six varieties were studied through monovarietal wines elaborated in the laboratory: Chardonnay (24 samples), Chenin (24), Petit Manseng (7), Sauvignon (37), Semillon (24), and Ugni Blanc (9). Homemade mixtures were elaborated from authentic monovarietal wines according to a Plackett-Burman sampling plan. After protein peak area normalization, a matrix was elaborated containing protein results of wines (mixtures and monovarietal). Partial least-squares processing was applied to this matrix allowing the elaboration of a model that provided a varietal quantification precision of around 20% for most of the grape varieties studied. The model was applied to commercial samples from various geographical origins, providing encouraging results for control purposes.     

How does economic research contribute to the management of forest ecosystem services?

Key message

More and more environmental and resource economists are taking a particular interest in research on forest ecosystem services (FES), especially in a context of climate change. Spatial and temporal issues are crucial to economic analyses and for the design of conservation policies. Interdisciplinary research involving ecological and economic disciplines is a prerequisite for the more effective management of forest ecosystems.

Context

Economists define non-market ecosystem services (ES) as public or common goods due to their characteristics of non-rivalry in terms of consumption and/or non-excludability. Just because they do not have a price does not mean that ES have no economic value because their social benefits are undoubtedly considerable. These features, associated with the market demand for timber and a poor climate risk assessment, may lead to the under-provision of non-market forest ES and the over-harvesting of timber.

Aims

In this article, we review research questions that are central to the enhancement of FES provision. Beyond the economic modelling of the joint provision of FES, we focus on issues related to the design of public policies to guide forest management. The objective is to provide crucial insights concerning the importance of a spatial and sustainable provision of FES.

Results

First, we provide an economic interpretation of the FES concept and a review of economic models of forest management. Second, we explain how spatial and temporal dimensions of FES can have major implications on their supply and demand. Both dimensions explain why FESs have to be taken into account in production decisions and public policies (including the design of payment for environmental services (PESs)).

Conclusion

A better understanding of FES provision and public policies to be enhanced is not possible without accounting for spatial and temporal dimensions. This helps to analyse the impact of intervention on FES and the cost-effectiveness of economic instruments, implying a coordinated effort to bring together ecological and economic data and models.

     

Comparing the photopic ERG i-wave in different species

The i‐wave, a post b‐wave component of the human photopic electroretinogram (ERG), is claimed to originate at the level of the retinal ganglion cells (RGC) or more distally. We investigated whether this wave is a feature common to all species. Photopic ERGs were obtained from the following species: Beagle dog, European cat, New Zealand white rabbit, Göttingen minipig, Cynomolgus monkey, Sprague–Dawley and brown Norway rats, Hartley guinea pig, and CD1 and C57BL6 mice. Results were compared with those obtained from normal human subjects. Except for rats and mice, all species yielded a well‐demarcated i‐wave, easily identifiable and separated from the a–b‐wave complex by ≈ 20 ms. Our sample suggests that the i‐wave is a feature common to the photopic ERG of most species including humans. In view of its suggested origin, the i‐wave would offer a unique opportunity to test, with the flash ERG, the functional integrity of the retinal ganglion cells in animals where use of a pattern stimulus is not always easily obtained.     

Research priorities for rice pest management in tropical Asia: a simulation analysis of yield losses and management efficiencies

ABSTRACT A simulation study was conducted to assess the current and prospective efficiency of rice pest management and develop research priorities for lowland production situations in tropical Asia. Simulation modeling with the RICEPEST model provided the flexibility required to address varying production situations and diverse pest profiles (bacterial leaf blight, sheath blight, brown spot, leaf blast, neck blast, sheath rot, white heads, dead hearts, brown plant-hoppers, insect defoliators, and weeds). Operational definitions for management efficacy (injury reduction) and management efficiency (yield gain) were developed. This approach enabled the modeling of scenarios pertaining to different pest management strategies within the agroecological contexts of rice production and their associated pest injuries. Rice pests could be classified into two broad research priority-setting categories with respect to simulated yield losses and management efficiencies. One group, including weeds, sheath blight, and brown spot, consists of pests for which effective pest management tools need to be developed. The second group consists of leaf blast, neck blast, bacterial leaf blight, and brown plant-hoppers, for which the efficiency of current management methods is to be maintained. Simulated yield losses in future production situations indicated that a new type of rice plant with high-harvest index and high-biomass production ("New Plant Type") was more vulnerable to pests than hybrid rice. Simulations also indicated that the impact of deployment of host resistance (e.g., through genetic engineering) was much larger when targeted against sheath blight than when targeted against stem borers. Simulated yield losses for combinations of production situations and injury profiles that dominate current lowland rice production in tropical Asia ranged from 140 to 230 g m(-2). For these combinations, the simulated efficiency of current pest management methods, expressed in terms of relative yield gains, ranged from 0.38 to 0.74. Overall, the analyses indicated that 120 to 200 x 10(6) tons of grain yield are lost yearly to pests over the 87 x 10(6) ha of lowland rice in tropical Asia. This also amounts to the potential gain that future pest management strategies could achieve, if deployed.     

Variations in acaricidal effect of wettable sulfur on Tetranychus urticae (Acari:Tetranychidae): effect of temperature,humidity and life stage

Under laboratory conditions, the acaricidal effect of wettable sulfur is influenced by climatic conditions and the stage of development of Tetranychus urticae. Its ovicidal effect results from the combined action of temperature and relative humidity (RH). Wettable sulfur becomes effective at 27.5 degrees C and 75% RH. Beyond this threshold, the acaricidal effect increases with rising temperature or humidity, to become complete at a temperature of 35 degrees C and 90% RH. Within the range of temperatures and humidities 20 degrees C/30% RH and 35 degrees C/90% RH the mortality of immatures (from protonymphs to teleiochrysalis) was total. Under similar experimental conditions, females usually died before the end of the experiment. Temperature and relative humidity increased the adulticidal potential of wettable sulfur. The fecundity of the sulfur-treated females and the viability of their progeny was found to depend on temperature and RH. According to the same climatic conditions, eggs were less susceptible than females, which were in turn less susceptible than juvenile stages.