Influence of Minerals on the Aetiology of Geophagia in Periurban Dairy Cattle in the Derived Savannah of Nigeria     

Smith JW  Adebowale EA  Ogundola FI  Taiwo AA  Akpavie SO  Larbi A  Jabbar MA 《Tropical animal health and production》2000,32(5):315-327

The aetiology of geophagia in periurban dairy cattle in Nigeria was assessed in relation to the mineral status of the serum, the herbage consumed, and the soil from where the herbage was consumed. The study was carried out using nine herds in the derived savannah zone during both the wet and dry seasons. Generally, the Na, Ca, Fe, Zn and Cu levels in the samples were adequate. However, the forages were low in Ca and the serum was deficient in P. Forage, soil and termite hill samples were also deficient in P. The low levels of P in the soil and termite hill samples showed that the consumption of sand by the cattle did not have any positive impact on their P intake. A seasonal effect was apparent (p<0.05) on the serum Na⁺, PO₄ ^3–, Cu²⁺ and Fe²⁺ concentrations but not on Ca²⁺ and Zn²⁺ concentrations. A seasonal effect was also significant (p<0.05) on the minerals in the forage. There were also seasonal differences in most of the soil and termite hill minerals. Most samples had higher (p<0.05) mineral levels in the dry season. Herd size and farming activity had no apparent influence on the aetiology of geophagia as they did not affect (p>0.05) the concentration of P in the serum, the reported cause of geophagia. Geophagia is probably caused by a marginal level of P in the serum and low levels in the forage and soil. Experimental trials will be required to confirm these observations.  相似文献   

Carbon isotopic signature of CO2 emitted by plant compartments and soil in two temperate deciduous forests     

Florence Maunoury-Danger  Nicolas Chemidlin Prevost Boure  Jérôme Ngao  Daniel Berveiller  Claude Brechet  Eric Dufrene  Daniel Epron  Jean-Christophe Lata  Bernard Longdoz  Caroline Lelarge-Trouverie  Jean-Yves Pontailler  Kamel Soudani  Claire Damesin 《Annals of Forest Science》2013,70(2):173-183

? Context

The carbon isotope composition of the CO₂ efflux (δ¹³C_E) from ecosystem components is widely used to investigate carbon cycles and budgets at different ecosystem scales. δ¹³C_E, was considered constant but is now known to vary along seasons. The seasonal variations have rarely been compared among different ecosystem components.

? Aims

We aimed to characterise simultaneously the seasonal dynamics of δ¹³C_E in different compartments of two temperate broadleaved forest ecosystems.

? Methods

Using manual chambers and isotope ratio mass spectrometry, we recorded simultaneously δ¹³C_E and δ¹³C of organic matter in sun leaves, current-year twigs, trunk bases and soil in an oak and a beech forest during 1 year.

? Results

In the two forests, δ¹³C_E displayed a larger variability in the tree components than in the soil. During the leafy period, a pronounced vertical zonation of δ¹³C_E was observed between the top (sun leaves and twigs with higher values) and bottom (trunk and soil with lower values) of the ecosystem. No correlation was found between δ¹³C_E and δ¹³C of organic matter. Causes for these seasonal variations and the vertical zonation in isotope signature are discussed.

? Conclusion

Our study shows clear differences in values as well as seasonal dynamics of δ¹³C_E among different components in the two ecosystems. The temporal and local variation of δ¹³C_E cannot be inferred from organic matter signature or CO₂ emission rates.  相似文献   

Insecticide residues in pollen and nectar of a cucurbit crop and their potential exposure to pollinators     

Dively GP  Kamel A 《Journal of agricultural and food chemistry》2012,60(18):4449-4456

Neonicotinoids are systemic insecticides widely used on many pollinated agricultural crops, and increasing evidence indicates that they move to some extent into pollen and nectar. This study measured levels of neonicotinoid residues in pollen and nectar from a pumpkin crop treated with formulated products containing imidacloprid, dinotefuran, and thiamethoxam using different timings and application methods. Environmental conditions have a significant effect on overall residue levels; nectar residues were 73.5-88.8% less than pollen residues, and metabolites accounted for 15.5-27.2% of the total residue amounts. Foliar-applied treatments and chemigated insecticides applied through drip irrigation during flowering resulted in the highest residues of parent insecticide and metabolites, which may reach average levels up to 122 ng/g in pollen and 17.6 ng/g in nectar. The lowest levels of residues were detected in treatment regimens involving applications of insecticides at planting, as either seed dressing, bedding tray drench, or transplant water treatment.  相似文献   

Tracheal respiration in insects visualized with synchrotron x-ray imaging     

Westneat MW  Betz O  Blob RW  Fezzaa K  Cooper WJ  Lee WK 《Science (New York, N.Y.)》2003,299(5606):558-560

Insects are known to exchange respiratory gases in their system of tracheal tubes by using either diffusion or changes in internal pressure that are produced through body motion or hemolymph circulation. However, the inability to see inside living insects has limited our understanding of their respiration mechanisms. We used a synchrotron beam to obtain x-ray videos of living, breathing insects. Beetles, crickets, and ants exhibited rapid cycles of tracheal compression and expansion in the head and thorax. Body movements and hemolymph circulation cannot account for these cycles; therefore, our observations demonstrate a previously unknown mechanism of respiration in insects analogous to the inflation and deflation of vertebrate lungs.  相似文献   

Regional and maturational effects on essential oils yields and composition of coriander (Coriandrum sativum L.) fruits     

Kamel Msaada  Mouna Ben Taarit  Karim Hosni  Mohamed Hammami  Brahim Marzouk 《Scientia Horticulturae》2009

The composition of volatile components of the essential oils extracted from fruits of coriander (Coriandrum sativum L.) growing in two different Tunisian regions in both Menzel Temime and Borj El Ifaa was studied by GC and GC–MS. The highest oil yields were observed at final stages of maturity: 0.324 ± 0.09% and 0.327 ± 0.08%, in Menzel Temime and Borj El Ifaa, respectively. Essential oil yields were highly (P < 0.001) affected by the growing region, stages of maturity and their interaction. Essential oil composition changed significantly (P < 0.05) among the different stages of maturity and growing region. Linalool and geranyl acetate were the main compounds at full fruit maturity in the two studied regions. Growing region, stages of maturity and their interaction had a strong effect (P < 0.001) on 35 compounds. α-Pinene, sabinene, limonene, γ-terpinene, cis-dihydrocarvone and geranial were insensible to the regional factor.  相似文献   

Mitochondrial Targeting in an Anti-Austerity Approach Involving Bioactive Metabolites Isolated from the Marine-Derived Fungus Aspergillus sp.     

Waleed A Abdel-Naime  Atsushi Kimishima  Andi Setiawan  John Refaat Fahim  Mostafa A. Fouad  Mohamed Salah Kamel  Masayoshi Arai 《Marine drugs》2020,18(11)

The tumor microenvironment is a nutrient-deficient region that alters the cancer cell phenotype to aggravate cancer pathology. The ability of cancer cells to tolerate nutrient starvation is referred to as austerity. Compounds that preferentially target cancer cells growing under nutrient-deficient conditions are being employed in anti-austerity approaches in anticancer drug discovery. Therefore, in this study, we investigated physcion (1) and 2-(2′,3-epoxy-1′,3′,5′-heptatrienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (2) obtained from a culture extract of the marine-derived fungus Aspergillus species (sp.), which were isolated from an unidentified marine sponge, as anti-austerity agents. The chemical structures of 1 and 2 were determined via spectroscopic analysis and comparison with authentic spectral data. Compounds 1 and 2 exhibited selective cytotoxicity against human pancreatic carcinoma PANC-1 cells cultured under glucose-deficient conditions, with IC₅₀ values of 6.0 and 1.7 µM, respectively. Compound 2 showed higher selective growth-inhibitory activity (505-fold higher) under glucose-deficient conditions than under general culture conditions. Further analysis of the mechanism underlying the anti-austerity activity of compounds 1 and 2 against glucose-starved PANC-1 cells suggested that they inhibited the mitochondrial electron transport chain.  相似文献   

Emergence de Ceratitis capitata (Diptera: Tephritidae) sur culture protégée de piment (Solanaceae) en zone subsaharienne (Algérie)     

O. Mostefaoui  M. Sekour  V. Balmès  M. Ben Halima Kamel 《EPPO Bulletin》2020,50(3):572-575

In Algeria, the Mediterranean fruit fly has long been associated with fruit production in coastal regions with a temperate climate. But with climate change, especially in autumn and spring, this fly has spread and attacks other host plants. The medfly appeared in the sub-Saharan area of Souf region (Algeria) on chilli pepper (Capsicum annuum) under protected crops and causes significant damage.  相似文献   

First report of Zaprionus indianus and Z. tuberculatus (Diptera: Drosophilidae) in Tunisia     

M. Ben Halima Kamel  Z. Ben Cheik  S. Zouari  L. Mdellel  V. Balmès 《EPPO Bulletin》2020,50(2):307-310

In October 2019, unusual damage was observed on Carissa macrocarpa (Apocynaceae) fruit at the ornamental nursery of the Higher Agronomic Institute (ISA CM), Chott Mariem (Sousse, Tunisia). Samples of fruit were collected and brought to the laboratory for observation and rearing. After a few days, adult flies emerged from infested fruit. Zaprionus indianus Gupta, Z. tuberculatus Malloch (Diptera Drosophilidae) and Ceratitis capitata Wiedemann (Diptera, Tephritidae) were identified morphologically. Information on the morphology, distribution and ecology of the two Zaprionus species are provided. This is the first record of Z. indianus and Z. tuberculatus in Tunisia.  相似文献   

Cystiphora sonchi (Vallot, 1827) (Diptera: Cecidomyiidae), first record for Tunisia and Africa     

M. Ben Halima Kamel  L. Mdellel  S. Zouari  V. Balmes 《EPPO Bulletin》2019,49(3):597-598

During 2017 and 2018, from June to October, leaf galls were observed for the first time on Sonchus oleraceus L. (Asteraceae), sow thistle, in Akouda‐Sousse, Tunisia. Leaves with galls were collected and brought to the laboratory. After a few days, adults emerged from the leaf galls. Morphological identification showed the emerged gall midges to be Cystiphora sonchi (Vallot, 1827) (Diptera: Cecidomyiidae). This is the first record of this species in Tunisia and Africa.  相似文献