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21.
Electrically coupled inhibitory interneurons dynamically control network excitability, yet little is known about how chemical and electrical synapses regulate their activity. Using two-photon glutamate uncaging and dendritic patch-clamp recordings, we found that the dendrites of cerebellar Golgi interneurons acted as passive cables. They conferred distance-dependent sublinear synaptic integration and weakened distal excitatory inputs. Gap junctions were present at a higher density on distal dendrites and contributed substantially to membrane conductance. Depolarization of one Golgi cell increased firing in its neighbors, and inclusion of dendritic gap junctions in interneuron network models enabled distal excitatory synapses to drive network activity more effectively. Our results suggest that dendritic gap junctions counteract sublinear dendritic integration by enabling excitatory synaptic charge to spread into the dendrites of neighboring inhibitory interneurons. 相似文献
22.
Gyimesi ZS Burns RB Campbell M Knightly F Kramer LW Wack RF Zuba JR Rings DM 《Journal of zoo and wildlife medicine》2011,42(2):281-290
Fatal abomasal impaction, often combined with omasal impaction, was diagnosed in 11 bongo (Tragelaphus eurycerus) from five different zoologic collections in the United States between 1981 and 2009. Nine of 11 cases occurred in young females (10 mo-7 yr old) and typical clinical signs prior to diagnosis or death included partial or complete anorexia, dehydration, and scant fecal production. Although the clinical histories in several of the earlier cases are incomplete, clinical signs were known to begin shortly after an anesthetic event in five of 11 bongo (45%). Pedigree analysis indicates that affected bongo were descendants of multiple founders and not from a single family line, suggesting that the development of abomasal impaction is not a strictly inheritable trait. Treatment, when attempted, was variable and included abomasotomy and removal of impacted ingesta, drug therapy (prokinetic drugs, nonsteroidal anti-inflammatories, antimicrobials), fluid therapy, and administration of oral lubricants or intralesional stool softeners. Based on the outcomes in the cases presented here, the prognosis for bongo with abomasal impaction is considered poor to grave. 相似文献
23.
Survey and molecular detection of phytoplasmas associated with potato in Romania and southern Russia
Ibolya Ember Zoltan Acs Joseph E. Munyaneza James M. Crosslin Maria Kolber 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(3):367-377
In recent years, emerging phytoplasma diseases of potato (Solanum tuberosum L.) have increasingly become important in central and eastern Europe. Accurate identification of phytoplasmas and their insect
vectors is essential to developing effective management strategies for diseases caused by these plant pathogens. Potato phytoplasma
diseases in Europe were for a long time diagnosed only on the basis of visual symptoms. However, this approach is not very
reliable and the use of modern molecular techniques such as polymerase chain reaction (PCR) is required in order to accurately
determine the etiology of these phytoplasma diseases. A survey and identification of phytoplasmas associated with potato crops
in Romania and southern Russia were conducted based on modern molecular techniques. Symptomatic potato plants were collected
from several fields and tested for phytoplasmas by PCR. Also, selected crops and weeds in the vicinity of these potato fields
were sampled and tested for phytoplasmas. Stolbur (“Candidatus Phytoplasma solani”; 16SrXII-A) was the only phytoplasma detected in potato and adjacent crops, including tomato (Solanum lycopersicum), pepper (Capsicum annuum), eggplant (Solanum melongena), and beet (Beta vulgaris). This phytoplasma was also detected in weeds, particularly Convolvulus arvensis, Cuscuta sp., and Euphorbia falcata. Genotyping of obtained stolbur isolates on tuf genes revealed that they all had the same RFLP profile corresponding to the tuf-type ‘b’ (VK Type II). Stolbur-affected potato
plants produced a large number of spongy tubers that resulted in commercially unacceptable potato chips upon processing. 相似文献
24.
Donald PF Sanderson FJ Burfield IJ Bierman SM Gregory RD Waliczky Z 《Science (New York, N.Y.)》2007,317(5839):810-813
Conservation of the planet's biodiversity will depend on international policy intervention, yet evidence-based assessment of the success of such intervention is lacking. Poor understanding of the effectiveness of international policy instruments exposes them to criticism or abandonment and reduces opportunities to improve them. Comparative analyses of population trends provide strong evidence for a positive impact of one such instrument, the European Union's Birds Directive, and we identify positive associations between the rate of provision of certain conservation measures through the directive and the response of bird populations. The results suggest that supranational conservation policy can bring measurable conservation benefits, although future assessments will require the setting of quantitative objectives and an increase in the availability of data from monitoring schemes. 相似文献
25.
Claudia Carranza Claudete S. Astolfi-Ferreira Silvana H. Santander Parra Luis F. N. Nuñez Zoltan Penzes Jorge L. Chacón 《British poultry science》2017,58(6):610-623
1. Infectious bronchitis virus (IBV) variants in Brazil were isolated during 2010–2015 for epidemiological and molecular analysis to characterise the different variants and perform a bioinformatic analysis to compare with sequences of variants collected over the previous 40 years.
2. Of the 453 samples examined, 61.4% were positive for IBV and 75.9% of these were considered to have the BR-I genotype and were detected in birds of all ages distributed in all five Brazilian regions.
3. The ratio of non-synonymous substitutions per non-synonymous site (dN) to synonymous substitutions per synonymous site (dS), i.e. dN/dS, revealed a predominance of codons with non-synonymous substitutions in the first third of the S1 gene and a dN/dS ratio of 0.67. Additionally, prediction of N-glycosylation sites showed that most of the BR-I variants (from 2003 to early 2014) had an extra site at amino acid position 20, whereas the newest variants lacked this extra site.
4. These results suggest that Brazilian IBV variants probably underwent drastic mutations at various points between 1983 and 2003 and that the selection processes became silent after achieving a sufficiently effective antigenic structure for invasion and replication in their hosts. Brazilian IBV genotype BR-I is currently the predominant genotype circulating in Brazil and South America. 相似文献
26.
Ward JL Poutanen K Gebruers K Piironen V Lampi AM Nyström L Andersson AA Aman P Boros D Rakszegi M Bedo Z Shewry PR 《Journal of agricultural and food chemistry》2008,56(21):9699-9709
One hundred and fifty bread wheat lines and 50 other lines of small-grain cereals (spelt, durum wheat, Triticum monococcum, Triticum dicoccum, oats, rye, and barley) were selected for diversity in their geographical origin, age, and characteristics. They were grown on a single site in Hungary in 2004-2005, harvested, milled, and analyzed for a range of phytochemicals (tocols, sterols, phenolic acids, folates, alkylresorcinols) and fiber components that are considered to have health benefits. Detailed analyses of these components in the different species are reported in a series of accompanying papers. The present paper discusses the comparative levels of the bioactive components in the different species, showing differences in both ranges and mean amounts. Furthermore, detailed comparisons of the bread wheat lines show that it is possible to identify lines in which high levels of phytochemicals and dietary fiber components are combined with good yield and processing quality. This means that commercially competitive lines with high levels of bioactive components are a realistic goal for plant breeders. 相似文献
27.
Siddall TL Ouse DG Benko ZL Garvin GM Jackson JL McQuiston JM Ricks MJ Thibault TD Turner JA Vanheertum JC Weimer MR 《Pest management science》2002,58(12):1175-1186
A novel series of substituted 3-phenyl benzoylpyrazoles were prepared and tested as potential grass herbicides. The targeted materials were prepared by three newly developed synthetic routes, which allowed a comprehensive study of the SAR (structure-activity relationships) of this series. The best combination of grass weed activity (Avena fatua L, Setaria viridis (L) Beauv and Alopecurus myosuroides Huds) and wheat selectivity was obtained with an alkoxy group in the 4-position of the phenyl ring. Activity was further enhanced by the presence of tert-butyl on the pyrazole and a methyl group at the C-2 position of the benzoyl moiety. The alkoxy-substituted 3-phenylbenzoylpyrazoles are a novel class of herbicides with potential utility for control of important grass weeds in cereals. 相似文献
28.
Tangential pitting in black spruce tracheids 总被引：1，自引：0，他引：1
Zoltan Koran 《Wood Science and Technology》1977,11(2):115-123
Tangential pit features were studied in a 55-year old black spruce (Picea mariana (Mill) B.S.P.) tree by means of light and electron microscopy.It was found that tangential pitting is lacking from the greatest part of the growth ring, except for the last four tangential rows of latewood tracheids and the first row of early wood tracheids. The average number of pits per tangential wall of a 3.55-mm-long tracheid is 234, 144, 28, 4 and zero, respectively, in the last 5 tangential rows of latewood tracheids, starting at the growth-ring boundary.On the average, tangential pits measure 5.4 m in diameter, possess oval to elliptical apertures, and are randomly distributed uniformly over the tangential tracheid wall. All tangential intertracheid pits are bordered and in that respect are similar to those in the radial walls. Although most of the pits contain membranes with tori, some at the growth-ring boundary lack tori and exhibit randomly oriented microfibrillar structure. 相似文献
29.
Zlatina Naydenova Zoltan Urshev Evgeny Golovinsky Konstantin Grancharov 《Pest management science》1996,47(1):25-30
Fifteen pesticides, representatives of different chemical groups, were tested for their inhibitory effect on the glucuronidation of 4-nitrophenol (4-NP) and phenolphthalein (PPh) by rat liver microsomes. Three herbicides (simazine, chlorsulfuron, tribenuron-methyl), two insecticides (dioxacarb, carbaryl) and one fungicide (zineb) significantly decreased the UDP-glucuronosyltransferase (UDPGT) activity. The carbamate insecticide dioxacarb was found to be the most potent inhibitor, at 1 mM concentration suppressing 4-NP-UDPGT activity completely, and reducing by 55% the activity associated with the conjugation of PPh. One millimole simazine and carbaryl affected only 4-NP glucuronidation, while chlorsulfuron and zineb exerted a marked inhibition of both 4-NP and PPh conversion. Concentrations of 0·1 mM carbaryl, dioxacarb and zineb were still inhibitory against 4-NP-UDPGT, with zineb producing 40% inhibition of PPh glucuronidation. As a whole, UDPGT isoforms conjugating PPh were less sensitive to the agrochemicals tested. Kinetic studies with dioxacarb, chlorsulfuron and carbaryl revealed a mixed type of inhibition with respect to the acceptor substrate 4-NP, with apparentKi values of 70 μM , 120 μM and 160 μM , respectively. 相似文献
30.