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81.
In a recent study we investigated the complex mechanisms regulating the pollen release via thigmonastic stamen movement found exclusively in Loasaceae subfamily Loasoideae. We demonstrated that stamen movement is modulated by abiotic (light and temperature) as well as biotic stimuli (pollinator availability and visitation frequency). This is explained as a mechanism to adjust the rate of stamen movement and thus pollen dispensation to different environmental conditions in order to optimize pollen transfer. Stamen movement is rapid and thus a near-immediate response to pollinator visits. However, Loasaceae flowers also show a response to biotic stimuli on a longer time scale, by adjusting the duration of both the staminate and the carpellate phase of the anthesis. We here present two additional data sets on species not previously studied, underscoring the shortening of the staminate phase in the presence of pollinator visits vs. their absence and the shortening of the carpellate phase after pollination. Overall, the plant shows not only a rapid but an “intelligent” reaction to its environment in adjusting anthesis and pollen presentation to a range of factors. The physiological and morphological bases of the stamen movement are poorly understood. Our previous study showed that there is no direct spatial relationship between the place of stimulation in the flower and the stamen bundle activated. We here further show the morphological basis for stamen movement from a reflexed into an erect position: Only the basal part of the filament curves around the receptacle, while the upper part of the filament retains its shape. We hypothesize that the stimulus is transmitted over the entire receptacle and the place of reaction is determined by stamen maturity, not the location of the stimulus. 相似文献
82.
T. B.C. Alavo K. J.C. Tégbéssou B. B. Yarou 《Archives Of Phytopathology And Plant Protection》2013,46(8):813-819
Intensive use of chemical insecticides against Helicoverpa armigera has led to the development of resistance to the major chemical families of insecticides. Consequently, management of H. armigera using conventional chemical insecticides is increasingly difficult. Methoxyfenozide is an agonist of the insect moulting hormone 20-hydroxyecdysone that acts faster than chitin synthesis inhibitors. The present work is aimed to assess the effectiveness of methoxyfenozide for use against H. armigera on cotton in Benin, West Africa. Laboratory tests and field experiments have been carried out. For laboratory studies, topical application of methoxyfenozide was done using L2 and L5 instar larva of H. armigera. Tested methoxyfenozide concentrations varied from 24 μl/ml to 144 μl/ml and the control is water only. For field experiments, a complete randomised block design was used with methoxyfenozide (72 μl/ml) and a control (no spraying). Berthoud Ultra Low Volume sprayer was used to spray methoxyfenozide suspension at 60-l per hectare. Two sprays were applied, 7 days apart. Laboratory tests indicated that 24 h after application of methoxyfenozide, about 100% of treated L2 and L5 larva were morbid or dead compared with 0% for the control larva. There are no significant differences between tested concentrations. Morbid larvae died within 2 days. In field experiments, cotton yield harvested on methoxyfenozide treated plants was double of that obtained on untreated plants (9375 kg and 4875 kg per hectare respectively). Thus methoxyfenozide may be used as component of Integrated Pest Control Programme on cotton in Benin, West Africa. 相似文献
83.
Ying Ma Shun-Xian Wang Yun Liu Guo-Guang Peng Xiao-Ming Wang Bo Zhang Bi-Hua Wu Ju-Ming Yu 《Gene》2013
Objectives
Ischemic stroke is influenced by both environmental and genetic factors. The CD40/CD40L system is related to proinflammatory and prothrombogenic responses, which are involved in the pathophysiology of ischemic stroke. The aim of this study was to evaluate association between the CD40 -1C/T single nucleotide polymorphism (SNP) and ischemic stroke in a Chinese population.Methods
We conducted a case–control study including 286 ischemic stroke patients and 336 controls. CD40 -1C/T SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing methods, and evaluated its relevance to ischemic stroke susceptibility.Results
Significantly increased ischemic stroke risk was found to be associated with the T allele of CD40 -1C/T (OR = 1.273, 95% CI = 1.016–1.594). The frequencies of CT and TT/CT genotypes of CD40 -1C/T in ischemic stroke patients were significantly higher than those of controls, respectively (for CT: OR = 2.350, 95% CI = 1.601–3.449; for TT/CT: OR = 2.148, 95% CI = 1.479–3.119). And, similar results were obtained after adjusting non-matched variables. We found that the frequency of carried T genotypes (TT and TT/CT) was significantly increased in patients with history of stroke compared with patients without (for TT: OR = 6.538, 95%CI = 1.655–25.833; for TT/CT: OR = 3.469, 95%CI = 1.031–11.670), respectively.Conclusions
The findings suggested that the CD40 -1C/T polymorphism might contribute to the susceptibility to ischemic stroke in the Chinese population, and might be associated with history of previous stroke. 相似文献84.
Bioinformatics tools have facilitated the reconstruction and analysis of cellular metabolism of various organisms based on information encoded in their genomes. Characterization of cellular metabolism is useful to understand the phenotypic capabilities of these organisms. It has been done quantitatively through the analysis of pathway operations. There are several in silico approaches for analyzing metabolic networks, including structural and stoichiometric analysis, metabolic flux analysis, metabolic control analysis, and several kinetic modeling based analyses. They can serve as a virtual laboratory to give insights into basic principles of cellular functions. This article summarizes the progress and advances in software and algorithm development for metabolic network analysis, along with their applications relevant to cellular physiology, and metabolic engineering with an emphasis on microbial strain optimization. Moreover, it provides a detailed comparative analysis of existing approaches under different categories. 相似文献
85.
G. M. Barker 《New Zealand journal of zoology.》2013,40(2):281-287
Abstract The slug Athoracophorus bitentaculatus (Quoy & Gaimard, 1832) is redescribed from material collected in the northern third of the North Island of New Zealand. Its anatomy is described and figured, local variation in the condition of the lateral grooves and mantle is figured, and supplementary information on its biology and distribution is given. Its identity and taxonomy are discussed in the context of earlier work on the species. Evidence is presented for the reduction of Reflectopallium Burton, 1963 to synonymy with Athoracophorus Gould, 1852. A revised key to New Zealand and subantarctic genera of Athoracophoridae is given. 相似文献
86.
《Science activities》2013,50(2):48-53
This article provides basic information on how a common species of earthworm, Eisenia fetida, can be used in the biology classroom as well as a discussion of how to establish and care for a vermicompost bin. We discuss ideas for inquiry activities with the organism and provide a sample-guided inquiry that demonstrates how a long-term, theme-based unit involving earthworms can address a wide variety of content from the National Science Education standards. 相似文献
87.
Jennifer M. Davis Elizabeth Hyjek Aliya N. Husain Le Shen Jennifer Jones Lucia A. Schuger 《The journal of histochemistry and cytochemistry》2013,61(8):580-590
Pulmonary lymphangioleiomyomatosis (LAM) is a rare, low-grade neoplasm affecting almost exclusively women of childbearing age. LAM belongs to the family of perivascular epithelioid cell tumors, characterized by spindle and epithelioid cells with smooth muscle and melanocytic differentiation. LAM cells infiltrate the lungs, producing multiple, bilateral lesions rich in lymphatic channels and forming cysts, leading to respiratory insufficiency. Here we used antibodies against four lymphatic endothelial markers—podoplanin (detected by D2-40), prospero homeobox 1 (PROX1), vascular endothelial growth factor receptor 3 (VEGFR-3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1)—to determine whether LAM cells show lymphatic differentiation. Twelve of 12 diagnostic biopsy specimens (early-stage LAM) and 19 of 19 explants (late-stage LAM) showed immunopositivity for D2-40 in most neoplastic cells. PROX1, VEGFR-3, and LYVE1 immunoreactivity varied from scarce in the early stage to abundant in the late stage. Lymphatic endothelial, smooth muscle, and melanocytic markers were partially co-localized. These findings indicate that lymphatic endothelial differentiation is a feature of LAM and provide evidence of a previously unidentified third lineage of differentiation in this neoplasm. This study has implications for the histological diagnosis of LAM, the origin of the neoplastic cells, and potential future treatment with drugs targeting lymphangiogenesis. 相似文献
88.
Michael Sean Sullivan 《Ocean Development & International Law》2013,44(3):203-268
In March 1995, Canadian fisheries authorities boarded and arrested the Spanish fishing vessel, Estai, outside the Canadian 200‐mile zone on the Grand Banks, an event that served to focus world attention on a dispute that had its origins in the failure of the 1982 United Nations Convention on the Law of the Sea to implement an effective conservation and management regime for fish stocks on the high seas, particularly with respect to fish stocks that straddle coastal states’ exclusive economic zones. This article examines the origins of the dispute, including the allegations relating to overfishing of North Atlantic Fisheries Organization‐recommended quotas, the background to the vessel's arrest, and the subsequent confrontation that occurred, both at diplomatic levels and on the high seas, between Canada and the European Union. An analysis is made of the case in international law for Canada's extension of jurisdiction beyond 200 miles pursuant to the provisions of Section 5 of the Coastal Fisheries Protection Act. Finally, the article examines the implications of the recently concluded Agreement on the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks for disputes of the kind that arose in the present case. 相似文献
89.
This article examines China's domestic legal regime for the prevention of vessel source pollution. It pays special attention to the recently adopted Regulation on Prevention and Control of Marine Pollution from Vessels. Potential challenges and emerging issues that China has to confront are addressed, including: application of the legislation to disputed sea areas between China and its neighbors, freedom of navigation in the exclusive economic zone, reduction of emission from ships, and prevention of invasive species from ballast water. 相似文献
90.
Robério C.S. Neves Allan T. Showler Ézio S. Pinto Cristina S. Bastos Jorge B. Torres 《Entomologia Experimentalis et Applicata》2013,146(2):276-285
Cotton pests damaging fruiting bodies (squares and young bolls) are difficult to control and their damage results in direct yield loss. Small growers, with low technological inputs, represent a large portion of cotton growers worldwide comprising more than 76 countries; they rely mainly on cultural practices to counteract pest attack in their crops. Boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), oviposition involves puncturing cotton squares and young bolls, causing abscission. We examined the impact on boll weevil population of collecting abscised cotton fruiting bodies and clipping plant terminals at 50% boll maturation in the field during two cotton‐growing seasons and under field cage conditions. Greatest numbers of damaged squares occurred ca. 117 days after planting and clipped plants resulted in reduction of abscised structures and adult boll weevils compared with non‐clipped plants, irrespective of cotton variety. Damaged young bolls were found ca. 128 days after planting in 2009 and 2011, but clipping had no effect. Numbers of boll weevils found in plants of the varieties BRS 201 and BRS Rubi (both in 2009) and BRS Rubi (in 2011) were, respectively, 13‐, 17‐, and 20‐fold greater when clipping plus collecting abscised fruiting bodies were not practiced. Furthermore, the average percentage of the boll weevil parasitoid Bracon vulgaris Ashmead (Hymenoptera: Braconidae) emerging from abscised and collected structures was similar between clipped and non‐clipped plant terminals in both seasons. Clipping plant terminals did not result in yield reduction and reduced adult boll weevil production. Collecting abscised reproductive structures, clipping plant terminals, and using both practices together reduced boll weevil populations by as much as 63, 57, and 79%, respectively, in cage trials. Thus, these practices cause significant impact on boll weevil populations and are feasible of adoption, especially for smallholder cotton growers. 相似文献