Fate and transport of bensulfuron-methyl and imazosulfuron in paddy fields: experiments and model simulation     

Kazuhiro Takagi  Ferdinand F. Fajardo  Masumi Ishizaka  Thai Khanh Phong  Hirozumi Watanabe  Julien Boulange 《Paddy and Water Environment》2012,10(2):139-151

Experiments were conducted to determine the fate of bensulfuron-methyl (BSM) and imazosulfuron (IMS) under paddy conditions. Initially, laboratory experiments were conducted and the photolysis half-lives of the two herbicides were found to be much shorter than their hydrolysis half-lives in aqueous solutions. In the aerobic water?Csoil system, dissipation followed first-order kinetics with water half-lives of 9.1 and 11.0?days and soil half-lives of 12.4 and 18.5 days (first phase) and 35.0 and 44.1 days (second phase) for bensulfuron-methyl and imazosulfuron, respectively. However, the anaerobic soil half-lives were only 12.7 and 9.8?days for BSM and IMS, respectively. The values of K _d were determined to be 16.0 and 13.8 for BSM and IMS, respectively. Subsequent field measurements for the two herbicides revealed that dissipation of both herbicides in paddy water involved biphasic first-order kinetics, with the dissipation rates in the first phase being much faster than those in the second phase. The dissipation of bensulfuron-methyl and imazosulfuron in the paddy surface soil were also followed biphasic first-order kinetics. These results were then used as input parameters for the PCPF-1 model to simulate the fate and transport of BSM and IMS in the paddy environment (water and 1-cm surface soil layer). The measured and simulated values agreed well and the mass balance error during the simulation period was ?1.2 and 2.8% of applied pesticide, respectively, for BSM and IMS.  相似文献   

Erratum to: Fate and transport of bensulfuron-methyl and imazosulfuron in paddy fields: experiments and model simulation     

Kazuhiro Takagi  Ferdinand F. Fajardo  Masumi Ishizaka  Thai Khanh Phong  Hirozumi Watanabe  Julien Boulange 《Paddy and Water Environment》2012,10(2):161-162

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Circadian rhythm dysfunction in glaucoma: A hypothesis     

Girardin Jean-Louis  Ferdinand Zizi  Douglas R Lazzaro  Arthur H Wolintz 《Journal of circadian rhythms》2008,6(1):1-8

The absence of circadian zeitgebers in the social environment causes circadian misalignment, which is often associated with sleep disturbances. Circadian misalignment, defined as a mismatch between the sleep-wake cycle and the timing of the circadian system, can occur either because of inadequate exposure to the light-dark cycle, the most important synchronizer of the circadian system, or reduction in light transmission resulting from ophthalmic diseases (e.g., senile miosis, cataract, diabetic retinopathy, macular degeneration, retinitis pigmentosa, and glaucoma). We propose that glaucoma may be the primary ocular disease that directly compromises photic input to the circadian time-keeping system because of inherent ganglion cell death. Glaucomatous damage to the ganglion cell layer might be particularly harmful to melanopsin. According to histologic and circadian data, a subset of intrinsically photoresponsive retinal ganglion cells, expressing melanopsin and cryptochromes, entrain the endogenous circadian system via transduction of photic input to the thalamus, projecting either to the suprachiasmatic nucleus or the lateral geniculate nucleus. Glaucoma provides a unique opportunity to explore whether in fact light transmission to the circadian system is compromised as a result of ganglion cell loss.  相似文献   

A review of carbon dynamics and assessment methods in the miombo woodlands     

Ferdinand Handavu  Paxie W Chirwa  Stephen Syampungani  Larwanou Mahamane 《Southern Forests》2017,79(2):95-102

Provision of accurate carbon (C) measurements and analysis are critical components in quantification of C stocks. The objectives of this review were to (1) compile and synthesise current knowledge of available methods for C stock estimation, (2) examine socio-economic drivers of land-use and land-cover change and their influence on woodland C stocks and (3) identify gaps of knowledge and methodological inadequacies in understanding factors affecting C stocks of major C pools for miombo woodlands of southern Africa. The review shows that quantification of forest C is a challenging task, mainly associated with knowledge gaps and methodological challenges. This has brought about a high level of uncertainty and inconsistencies, mainly due to the accounting methods applied. Furthermore, it is necessary to consider the inherent spatial heterogeneity of the landscape and stand density in order to ensure development of accurate C estimation methodologies when developing C models. Ultimately, developing widely applicable biomass models for southern Africa will require detailed assessments, including different aspects of wood C fractions. It is evident from the review that a comprehensive understanding of socio-economic drivers of land-use and land-cover change is necessary to ensure better-informed sustainable forest management policy direction, strategy and practice to deliver C and livelihood options.  相似文献   

Antibodies to bovine leukemia virus in a leukosis dairy herd and suggestions for control of the infection.          下载免费PDF全文

G A Ferdinand  A Langston  R Ruppanner  S Drlica  G H Theilen    D E Behymer 《Canadian journal of veterinary research》1979,43(2):173-179

A closed herd of 765 Holstein-Friesian dairy cattle with a history of multiple cases of leukosis was tested for antibodies to bovine leukemia virus by the bovine leukemia-glycoprotein immunodiffusion test. A total of 355 animals (46.4%) were antibody positive. Prevalence was 60% in the 373 milking cows and 100% in the breeding bulls. Antibodies were present in 59% of newborn calves. Prevalence of antibodies was higher in older animals and cows in second lactation had a higher prevalence than cows in first lactation (72% vs 43%). Proposed control measures in this herd aim at preventing infection of calves, heifers and lactating cows by: 1) separating them into groups negative and positive for bovine leukemia virus antibodies, 2) not allowing calves to receive colstrum or milk from infected cows and 3) by using seronegative bulls for natural breeding tested at three month intervals. Calves should be tested after six months of age. Before this time calves of positive mothers should be treated as being positive.  相似文献   

Cyanide-free Net-caught Fish for the Marine Aquarium Trade   总被引：1，自引：0，他引：1  

Peter J. Rubec  Ferdinand Cruz  Vaughan Pratt  Richard Oellers  Brian McCullough  Frank Lallo 《Aquarium Sciences and Conservation》2001,3(1-3):37-51

The International Marinelife Alliance (IMA) has been training collectors in the Philippines and Indonesia to use barrier-nets rather than sodium cyanide to capture marine-aquarium fish. Despite the training, collectors have been slow to switch to using nets because they can earn more using cyanide. A new Philippine export company has agreed to pay the collectors more for net-caught fish and to adhere to standards being set by the USA-based Marine Aquarium Council. The IMA is monitoring the collectors and conducting cyanide testing to certify that the fish are net-caught and totally cyanide-free. Clearance certificates now accompany shipments of these marine-aquarium fish being shipped to wholesalers and retailers associated with the American Marine Dealers Association (AMDA) situated in the USA and Canada. AMDA members are being surveyed to assess whether the net-caught fish are more cost competitive compared to cyanide-caught fish for the marine ornamental fish trade because of reduced mortality through the chain from reef to retailer.  相似文献