Co‐management in Latin American small‐scale shellfisheries: assessment from long‐term case studies

Co‐management (Co‐M), defined as the sharing of management tasks and responsibilities between governments and local users, is emerging as a powerful institutional arrangement to redress fisheries paradigm failures, yet long‐term assessments of its performance are lacking. A comparative analysis of five small‐scale Latin American shellfisheries was conducted to identify factors suggesting success and failure. In Chile, Uruguay and Mexico Co‐M produced positive effects, including stabilization of landings at low levels, increase in abundance, CPUE, unit prices and revenues per unit of effort, and reduced interannual variability in several fishery indicators, particularly in landings. Co‐M was successful because it was mainly bottom‐up implemented and accompanied by‐catch shares (spatial property rights and community quotas). By contrast, Co‐M implementation was unable to prevent the collapse of the Galapagos sea cucumber fishery, as reflected by a decrease in abundance and CPUE. Negative effects were also observed in the Galapagos spiny lobster fishery during Co‐M implementation. However, recovery was observed in recent years, reflected in a stabilization of fishing effort and the highest CPUE and economic revenues observed since the beginning of the Co‐M implementation phase. The combined effects of market forces, climate variability and a moratorium on fishing effort were critical in fishery recovery. We conclude that Co‐M is not a blueprint that can be applied to all shellfisheries to enhance their governability. These social–ecological systems need to be managed by jointly addressing problems related to the resources, their marine environment and the people targeting them, accounting for their socioeconomic and cultural contexts.     

The effect of some cryoprotectants on dromedary camel frozen‐thawed semen

The cryopreserved camel semen is often associated with poor quality and fertility. This study aimed to improve the dromedary frozen semen quality by comparing the efficiency of four cryoprotectant agents (CPAs) on sperm freezability. Semen samples were collected from seven male Maghrabi camels, diluted with Shotor diluent supplemented with glycerol (Sh‐G), dimethyl formamide (DMF, Sh‐DF), dimethyl sulfoxide (DMSO, Sh‐DS) or ethylene glycol (EG, Sh‐EG), all at 6% final concentration, and the samples were subjected to cryopreservation. The results revealed the superiority of Sh‐DF over Sh‐G and Sh‐DS in terms of post‐thaw motility (55.83 ± 2.20 vs. 47.50 ± 4.33 and 45.00 ± 2.89%, respectively), sperm membrane (49.00 ± 0.58, 39.33 ± 3.33 and 42.67 ± 1.45%, respectively) and acrosomal integrities (53.00 ± 0.58, 57.33 ± 0.88 and 52.33 ± 1.45%, respectively). Sh‐EG group showed the lowest post‐thaw motility, plasma membrane and acrosome integrities (12.50 ± 1.44, 22.67 ± 1.45 and 30.67 ± 1.45, respectively). In conclusion, the protocols of dromedary camel semen cryopreservation could be enhanced using 6% DMF as a cryoprotectant agent.     

Cardiac biomarker changes in camels (Camelus dromedarius) secondary to road transportation

ObjectivesLittle is known about cardiac biomarkers in camels despite their extensive use as draft animals. This study was designed to establish reference ranges for the cardiac biomarkers cardiac troponin I (cTnI) and creatine kinase myocardial b fraction (CK-MB) in healthy camels and to investigate their changes in response to road transportation.AnimalsTwenty-five healthy camels transported for a 5 h round-trip journey.MethodsNone of the camels had evidence of cardiac abnormalities on cardiac auscultation, echocardiography or electrocardiography. Three blood samples were obtained from each camel: 24 h before transportation (T0), within 2 h after unloading (T1) and 24 h after transportation (T2).ResultsThe mean cTnI concentration in the camels was 0.032 ± 0.023 ng/mL. All the camels had resting cTnI concentrations of <0.08 ng/mL. At T1, the cTnI concentration was significantly higher (P < 0.001) in all 25 camels compared to values at T0. The CK-MB concentration in the camels was 0.19 ± 0.05 ng/mL. All the camels had resting CK-MB concentrations of <0.33 ng/mL. At T1, the CK-MB concentration was higher in 3/25 camels compared to values at both T0 and T2. Concerning the hematobiochemical variables, significant increases were detected at T1 in total white blood cells, total protein, globulin, magnesium and phosphorus. Cardiac troponin I, CK-MB and all the hematobiochemical parameters had returned to their pre-transport values at T2.Conclusions5 h road transportation might have transient adverse effects on the cardiac muscle of healthy camels.     

准噶尔盆地东南缘绿洲-荒漠交错带土壤螨类的群落多样性与相似性

为了查明准噶尔盆地东南缘绿洲-荒漠交错带土壤螨类群落多样性与相似性特征,于2010年4月、7月、9月和11月中旬对该区的自然林、防护林、耕地、菜瓜地、荒草原、灌木林及荒漠等7种不同生境进行采样调查研究。结果表明,共获得土壤螨类5200只,隶属于4目41科61属。在7种不同生境土壤螨类群落多样性间具有明显的差异(p<0.05),Shannon-Wiener多样性指数(H)顺序为灌木林>防护林>自然林>荒草原>耕地>荒漠>菜瓜地,Margalef丰富度指数(M)顺序为自然林>防护林>灌木林>荒草原>耕地>菜瓜地>荒漠。Jaccard群落相似性分析表明,不同生境土壤螨类相似性程度主要为中等不相似(处于0.25～0.50),而在荒漠与自然林、防护林及灌木林之间的相似程度已达到极不相似水平。7种生境土壤螨类聚类和排序分析结果分为林地环境类型、耕作环境类型、荒漠草原环境类型和荒漠环境类型等四大类型。研究结果表明植被类型、土壤湿度和人为干扰是影响土壤螨类群落多样性及其动态变化的主要因素。     

Efficacy of genotype-matched Newcastle disease virus vaccine formulated in carboxymethyl sago starch acid hydrogel in chickens vaccinated via different routes

BackgroundThe commercially available Newcastle disease (ND) vaccines were developed based on Newcastle disease virus (NDV) isolates genetically divergent from field strains that can only prevent clinical disease, not shedding of virulent heterologous virus, highlighting the need to develop genotype-matched vaccinesObjectivesThis study examined the efficacy of the NDV genotype-matched vaccine, mIBS025 strain formulated in standard vaccine stabilizer, and in carboxymethyl sago starch-acid hydrogel (CMSS-AH) following vaccination via an eye drop (ED) and drinking water (DW).MethodsA challenge virus was prepared from a recent NDV isolated from ND vaccinated flock. Groups of specific-pathogen-free chickens were vaccinated with mIBS025 vaccine strain prepared in a standard vaccine stabilizer and CMSS-AH via ED and DW and then challenged with the UPM/NDV/IBS362/2016 strain.ResultsChickens vaccinated with CMSS-AH mIBS025 ED (group 2) developed the earliest and highest Hemagglutination Inhibition (HI) NDV antibody titer (8log₂) followed by standard mIBS025 ED (group 3) (7log₂) both conferred complete protection and drastically reduced virus shedding. By contrast, chickens vaccinated with standard mIBS025 DW (group 5) and CMSS-AH mIBS025 DW (group 4) developed low HI NDV antibody titers of 4log₂ and 3log₂, respectively, which correspondingly conferred only 50% and 60% protection and continuously shed the virulent virus via the oropharyngeal and cloacal routes until the end of the study at 14 dpc.ConclusionsThe efficacy of mIBS025 vaccines prepared in a standard vaccine stabilizer or CMSS-AH was affected by the vaccination routes. The groups vaccinated via ED had better protective immunity than those vaccinated via DW.     

Histomorphological,ultrastructural and morphometrical age-related changes of fundic region of New Zealand rabbits (Oryctolagus cuniculus)

This study investigated the histomorphological, ultrastructural and morphometrical postnatal developmental changes in the rabbit fundic region, especially during changing of the feeding intake. Seventy-two New Zealand rabbits (V-Line breed) at the ages of 1, 7, 15, 23, 30 and 60 days were obtained for light and electron microscopy and morphometric studies of the fundic region. The newborn rabbit's fundic wall was thin and organized into mucosa, submucosa, musclosa and serosa, with a significant increase in thickness with ageing. The fundic glands were few at the first week of life, then increased in length and diameter compared to the preceding age with prominent zonation at 23 days. The gastric pits appeared wide and deep at the first week of life then became typically narrow and shallow at the third week. The mucous cells were the main cell types lining the fundic glands in the first week of life. These cells showed remoulding with a marked increase in Periodic Acid–Schiff reactivity with age. Parietal cells were differentiated earlier (on the first day of life) than the chief cells and distributed at the neck and basal zones. Chief cells differentiated at 15 days old at the base of the glands, followed by an increase in the number and activity. Few active enteroendocrine cells were first seen at 15 days old and then widely distributed throughout the glands. Conclusion: Pronounced histomorphological changes in the fundic mucosal layer, especially the surface and glandular epithelium, correlate with the postnatal rabbit-feeding intake changes.     

The response of potato crop to the spatiotemporal variability of soil compaction under centre pivot irrigation system

Precision agriculture techniques were employed to study the impact of the spatiotemporal variations of soil compaction on the performance of potato crop during its various growth stages. The study has been conducted on a 30 ha centre pivot irrigated potato field, located in Wadi Al-Dawasir area in Saudi Arabia. In situ soil compaction measurements were collected, in conjunction with Sentinel-2A satellite data, and correlated spatiotemporally against potato crop growth and yield parameters. The univariate and bivariate Moran's function (Moran's I), the linear regression and the analysis of variance (ANOVA) techniques were used to analyse the data and examine the interrelationships. The spatial correlations between the measured variables revealed high clustering, producing Moran's I of 0.87, 0.79 and 0.57 for soil compaction, yield and normalized difference vegetation index (NDVI), respectively. Compaction-yield relationship revealed a relatively high significant negative spatial correlation (Moran's I = 0.68). While, the spatial correlation between the average values of compaction and NDVI has negatively produced a Moran's I value of 0.45 (at 0.001 significance level), when 999 permutations were tested for all relationships. A significant positive correlation was observed between high compaction and high proportion of small size tubers, with R² and P > F values of 0.65 and .0001, respectively. In contrast, a significant negative correlation has been obtained between high compaction and high proportion of large size tubers, with R² and P > F values of 0.57 and .0001, respectively. Understanding the causes of disparity in the productivity of agricultural fields will help decision-makers and farmers to take proactive actions towards better agricultural practices.     

Green nanoemulsion‐laden glyphosate isopropylamine formulation in suppressing creeping foxglove (A. gangetica), slender button weed (D. ocimifolia) and buffalo grass (P. conjugatum)

BACKGROUND: Pesticides are developed with carriers to improve their physicochemical properties and, accordingly, the bioefficacy of the applied formulation. For foliar‐applied herbicide, generally less than 0.1% of the active ingredient reaching the target site could reduce pesticide performance. Recently, a carrier of nanoemulsion consisting of oil, surfactant and water, with a particle size of less than 200 nm, has been shown to enhance drug permeability for skin penetration in pharmaceutical delivery systems. In the present work, the aim was to formulate a water‐soluble herbicide, glyphosate isopropylamine (IPA), using a green nanoemulsion system for a biological activity study against the weeds creeping foxglove, slender button weed and buffalo grass. RESULTS: The nanoemulsion formulations displayed a significantly lower spray deposition on creeping foxglove (2.9–3.5 ng cm^?2), slender button weed (2.6–2.9 ng cm^?2) and buffalo grass (1.8–2.4 ng cm^?2) than Roundup^® (3.7–5.1 ng cm^?2). The visible injury rates of weeds treated with the nanoemulsion formulations were statistically equivalent to those relating to Roundup^® at 14 days after treatment, with a control range of 86.67–96.67%. CONCLUSION: It was hypothesised that the significant difference in spray deposition with equal injury rates can be attributed to enhanced bioactivity of the nanoemulsion formulations. This initial discovery could be the platform for developing better penetration of agrochemical formulations in the future. Copyright © 2012 Society of Chemical Industry     

Genetic variation in Tunisian melon (Cucumis melo L.) germplasm as assessed by morphological traits

The morphological variation and the systematical status of 28 traditional melon including two ancient varieties collected from different geographical and bioclimatic areas of Tunisia were assessed based on 34 qualitative and quantitative traits. Yellow Canary was used as a reference variety. Significant differences among accessions within and among sites of collection were revealed for the majority of traits. The accessions from the Sahel were more polymorphic than those from Tozeur’s oasis. However, the classification of the local accessions according to Munger and Robinson’s varietal groups did not allow clear segregation of several of them because of their high heterogeneity. The principal component analysis (PCA) performed on all measured traits, allowed a distinction among the introduced varieties clustered according to their varietal group, and the local accessions grouped separately according to their geographical origin and bioclimatic zone. Mahalanobis distances among PCA’s groups were significant. The correlation found between Mahalanobis distance matrix and geographical distance matrix among origins corroborated isolation per distance. Conservation strategies should be made appropriately according to origins. Accessions from the Sahel showing the highest polymorphism within and among sites of collection should be firstly preserved.     

Natural variation of Medicago truncatula resistance to Aphanomyces euteiches

We analysed the resistance variation in 14 natural populations of Medicago truncatula from Tunisia to Aphanomyces euteiches infection. The reaction of M. truncatula lines to A. euteiches infection varied from susceptibility to full resistance. Of the overall level of phenotypic variation, 65.4 % was found to occur within populations. Principal component analysis showed a high spread of lines belonging to the same population, indicating no clear structure in the Tunisian M. truncatula populations and supporting the hypothesis of gene flow among populations. Likewise, there was no association between local resistance composition and the geographical distances between populations, ruling out isolation by distance as an explanation. Furthermore, significant correlations were observed between quantitative traits and ecological factors consistent with the local adaptation hypothesis. A cluster analysis of the populations showed the presence of three groups. The first group comprised the populations originating from the centre of the country, containing the main resistant lines. The second group included the populations collected in the south and the mountain region of Thala and contained the main partially resistant lines. The third group comprised the populations sampled from the north regions and saline soils and included the main susceptible lines. Overall, we found that the natural M. truncatula lines were more likely to be susceptible (71.3 %) than resistant (28.7 %) to A. euteiches attack. Nevertheless, many resistant lines exhibiting new reaction patterns to A. euteiches attack were identified in the natural populations and these can be used for the identification of potentially new resistance genes.