A probable pteridosperm from the uppermost Devonian near Ballyheigue, Go. Kerry, Ireland

A new genus of pleridosperms is described from the uppermost Devonian beds from Ballyheigue, Ireland. I.aceya hibernica May & Mat ten is represented by stems bearing spirally arranged fronds. The base of the frond is swollen and is about the same size as the stem. Pinnae are borne alternately and apparently in one plane on the rachis. The anatomy of the stem reveals a three-fluted protostele. Secondary xylem consists of rays and trachcids and secondary phloem is present. The inner cortex contains probable secretory and/or sclerotic cells. The outer cortex is of the spargaimm-type. Rachial trace formation is described. The U-shaped xylem strand of the rachis lacks secondary tissue. Pinnae traces are V- to C-shaped. A presumed adventitious root has a triarch protostele, a parenchymatous cortex and lacks a 'sparganum' outer zone. I.aceya is believed to be a member of the Lyginopleridaceae. The divisions of the sympodial protoxylem strand forming the rachial trace is compared among the Aneurophytales, Buteoxylonaceae, Calamopityaceae and Lyginopteridaceae and is shown to be similar.     

Oxygen consumption of active and inactive adult tiger beetles

ABSTRACT. Oxygen consumption (O₂) in six species of adult tiger beetles Cicindela spp. (Coleoptera: Cicindelidae) was correlated with body mass and temperature during rest. In beetles forced to run and/or right themselves continuously for 5–10 min at 25°C, O₂ was approximately 7–12 times as high as in resting individuals; the difference increased with increasing mass. Resting and active VO₂ were similar to previous results for other beetles, although the slope of log O₂ on log mass was lower. Detailed analysis suggests the existence of taxonomic and ecological correlates of resting metabolism. The possible ecological implications and adaptive advantages of these results for adult tiger beetles are discussed.     

Generalist and specialist host–parasitoid associations respond differently to wild parsnip (Pastinaca sativa) defensive chemistry

1. Plant defensive chemistry is predicted to have a more negative effect on generalist herbivores and their parasitoids than on specialist herbivores and their parasitoids. 2. This prediction was examined by comparing the effects of the wild parsnip (Pastinaca sativa L.) toxin, xanthotoxin, on a generalist herbivore–parasitoid association [the cabbage looper, Trichoplusia ni Hübner, and its polyembryonic parasitoid, Copidosoma floridanum (Ashmead)] and a specialist herbivore–parasitoid association [the parsnip webworm, Depressaria pastinacella (Duponchel), and its polyembryonic parasitoid, Copidosoma sosares (Walker)]. 3. Copidosoma floridanum brood sizes were smaller and experienced lower survivorship when reared in a host feeding on an artificial diet containing a low concentration of xanthotoxin. No T. ni hosts, parasitised or unparasitised, survived on a diet high in xanthotoxin. In contrast, C. sosares brood size and survivorship were unaffected by the presence of low levels of xanthotoxin in the host diet. Copidosoma sosares experienced reduced brood size and survivorship only when its host consumed a diet containing 15 times the level of xanthotoxin as the diet adversely affecting its congener. 4. The differences in response to xanthotoxin exhibited by C. floridanum and C. sosares are explained partly by a differential reduction in host quality and partly by differential exposure to xanthotoxin in host haemolymph. Unlike D. pastinacella, T. ni experienced reduced pupal weight and survivorship and prolonged developmental time on a low‐xanthotoxin diet. More xanthotoxin passed unmetabolised into the haemolymph of T. ni than into the haemolymph of D. pastinacella.     

静止性脑梗死与血管性痴呆相关性的病例对照分析

目的　探讨静止性脑梗死 (SCI)与血管性痴呆 (VD)的关系。　方法　采用病例对照的方法对 1 2 6例血管性痴呆病人和 1 2 6例非痴呆病人进行 CT或 MRI检查 ,比较两组 SCI的发生状况。　结果　1 2 6例 VD中发现 SCI5 3例 (4 2 .1 % ) ,1 2 6例非痴呆病人中发现 SCI2 2例 (1 7.5 % ) ,两组比较有高度显著性差异 (P <0 .0 1 )。　结论　 SCI与 VD密切相关     

Distribution and role of calmodulin in tip growing hyphae of Saprolegnia ferax

INTanDUCTIONFungalhyphaeextendbytipgrowthandhaveahigherconceotration0fCa2 intheiraPicesthantheirbases,afactwhichispr0bablyrelatedt0theimp0rtentroleplayedbycalcinminestablishingandmaintainingapical0rganizati0n,mor-ph0g9nesis,and,grtiWth[1-6].Tounderstandthethefullcti0nofCa2 inhyphaltipgrbwth,'Ca' -bindingproteinsmustbeidentifiedandtheirflincti0nsdetermined.CaM,a,ubiquitousilltracellularCa' -bindingpr0teinwhichfuncti0nst0mediatemanyCa' -regulatedpr0cessesincells,naturallyhasbeenreceivedal…     

白细胞介素－1β对胰岛素分泌的抑制及睾酮的反转作用

离体培养新生大鼠胰岛细胞用ＩＬ－１β（５—２０Ｕ／ｍｌ）处理２０ｈ后，可使胰岛细胞在高糖（２０ｍｍｏｌ／Ｌ）刺激下的胰岛素释放量明显降低。对ＩＬ－１β处理后的胰岛给予睾酮（１０－１０ｍｏｌ／Ｌ），则能反转ＩＬ－１β的抑制效应，并且睾酮不仅增加胰岛素分泌，而且还可促进胰岛细胞内胰岛素含量的增加。