共查询到20条相似文献,搜索用时 46 毫秒
1.
This volume is a timely updateand considerable expansion of the small book Seed Ecology, publishedby the first author twenty years ago, and long out of print. Is it useful to separate a particular branch of study such asseed ecology from the wider field of plant ecology?Aren't seeds just a particular packaged form of the sporophyte,at a certain stage in its life cycle? While some may ask thosequestions, a major strength of this book is the care that theauthors take throughout to set their review in the context ofcurrent ecological 相似文献
2.
Over 40 years ago, in what is surelyone of the most famous throw-away lines in botany,Ledbetter and Porter (1963) suggested that the similar orientationsof cytoplasmic microtubules and structures considered to becellulose microfibrils in the cell wall was not coincidental.This notion led almost single-handedly to the present and enduringinterest amongst certain plant cell biologists in understandingthe role of microtubules in wall formation. And as a resultof this intense interest in such matters, it has become clearthat microtubules are not only just one componentamongst an ever-expanding array of 相似文献
3.
Delight said CharlesDarwin in his diaries in 1832, is a weak term to expressthe feelings of a naturalist who, for the first time, has wanderedby himself in a Brazilian forest. These feelings musthave been those which drove Margaret Mee to explore the Brazilianjungles on numerous expeditions between 1958 and 1964, creatingwonderful pictures despite all kinds of difficulties encounteredin this hostile world. And these feelings were also those Ihad when I read this book: delight about her precise drawingsand life-like paintings, which are extremely expressive from 相似文献
4.
The motto of the PhotosynthesisCongress in Brisbane in 2001 was that photosynthesissimply sustains all life on Earth. For this reason, photosynthesisis a large, well-researched area, so it is especially ambitiousto put together a handbook that attempts to cover the wholesubject. This volume is definitely not a handbook in the sensethat it provides a compendium for the novice, but instead itis a conspectus of areas of 相似文献
5.
This volume isthe proceedings of an international congress held at the Universityof Bologna, Italy, 2731 May 2003. Major sections aredevoted to the architects of the green revolution: biodiversityand germplasm 相似文献
6.
This book has beenwritten primarily as a text for a senior plant anatomy course.The initial phrase An introduction to is somewhatmisleading as a student would need to have some elementary knowledgeof botany as well as cell structure and physiology to followthe information and the ideas without difficulty. The authordoes 相似文献
7.
Plant nutritionis ultimately an applied subject that seeks to understand theprocesses and mechanisms that underpin the uptake, assimilationand internal redistribution of nutrients by plants and thento use this information to improve the yield or quality of harvestedplant parts, be they grains, storage roots or leafy vegetables.The subject now also encompasses the understanding of the responsesof plants to nutrient toxicities (e.g. salinity) as well asnew topics such as metal hyperaccumulation and 相似文献
8.
Googling the termmolecular ecotoxicology results in less than 1000hits compared to more than 8·5 million for moleculargenetics. Hence, we are dealing with a rather new orless well-defined and less propagated field of science. Springer'sbook Molecular ecotoxicology of plants edited by H. Sandermannmay therefore fill a gap and it is unique in focusing on plants.A first introductory chapter sets the stage and tries to definethe term for a broad 相似文献
9.
The InstantNotes series from Bios will probably be familiar to manyreaders. The series' success is evident in the second editionsthat are appearing, e.g. the current volumealbeit nowunder the Taylor and Francis label. Content This book does what it says on the label; it provides noteson (probably) all of the topics within the compass of present-dayplant biology. Primarily, it deals with anatomy,growth and development, physiology, reproduction, and economicuses and ecology of flowering plants (angiosperms). However,it does cover other phyla of the Kingdom Plantae (principallyin two taxonomy/evolution sections), and algae(along 相似文献
10.
11.
This book (a translation fromSchulze et al., 2002) is one of the most comprehensive textbooksof plant ecology so far. The authors aim to for the firsttime bring together and clearly organize the large subdisciplinesof plant ecology and, to a large extent they have succeeded.The book is well written, and its more than 500 illustrationsare beautifully laid out and well chosen to help the readerunderstand the theory. It is clearly suitable not only 相似文献
12.
Guizy M Arias C David M González T Valenzuela C 《American journal of physiology. Cell physiology》2005,289(5):C1251-C1260
Dietary polyunsaturated fatty acids (PUFAs) have been reported to exhibit antiarrhythmic properties, which have been attributed to their availability to modulate Na+, Ca2+, and several K+ channels. However, their effects on human ether-a-go-go-related gene (HERG) channels are unknown. In this study we have analyzed the effects of arachidonic acid (AA, -6) and docosahexaenoic acid (DHA, -3) on HERG channels stably expressed in Chinese hamster ovary cells by using the whole cell patch-clamp technique. At 10 µM, AA and DHA blocked HERG channels, at the end of 5-s pulses to 10 mV, to a similar extent (37.7 ± 2.4% vs. 50.2 ± 8.1%, n = 710, P > 0.05). 5,6,11,14-Eicosatetrayenoic acid, a nonmetabolizable AA analog, induced effects similar to those of AA on HERG current. Both PUFAs shifted the midpoint of activation curves of HERG channels by 5.1 ± 1.8 mV (n = 10, P < 0.05) and 11.2 ± 1.1 mV (n = 7, P < 0.01). Also, AA and DHA shifted the midpoint of inactivation curves by +12.0 ± 3.9 mV (n = 4; P < 0.05) and +15.8 ± 4.3 mV (n = 4; P < 0.05), respectively. DHA and AA accelerated the deactivation kinetics and slowed the inactivation kinetics at potentials positive to +40 mV. Block induced by DHA, but not that produced by AA, was higher when measured after applying a pulse to 120 mV (IO). Finally, both AA and DHA induced a use-dependent inhibition of HERG channels. In summary, block induced by AA and DHA was time, voltage, and use dependent. The results obtained suggest that both PUFAs bind preferentially to the open state of the channel, although an interaction with inactivated HERG channels cannot be ruled out for AA. K+ channel; membrane currents; ion channels; arrhythmia; antiarrhythmics 相似文献
13.
All but five of the 46 contributionsin this symposium volume have been published already as a specialissue in Volume 255 of Plant and Soil in 2003. They are reproducedin exactly the same format and with the same pagination as inthe journal. To anyone who has access to Plant and Soil thisbook would therefore not be a sensible purchase. This is allthe more true because the editor has not provided any commentaryon the papers or subdivided them 相似文献
14.
The motivationfor producing this book is summed up in its last chapter byone of the editors: Life sciences concentrate on lifeand death; this simple statement stands for most of the urgentethical problems these sciences are confronted with ... Thelife sciences cannot escape from ethical issues, controversies,dilemmas even ... In this collection of papers we have intensivelydiscussed the new and often uncertain aspects of 相似文献
15.
In photosynthesis, CO2 enters theleaf from the atmosphere and moves to the active site of thecarboxylating enzyme, to be bound in an organic compound. Theprocess is largely diffusional and the pathway, although complicatedin detail, is usually split into sections related to differentanatomic structures, such as chloroplasts, cell walls, intercellularair space, stomatal pores and, finally the leaf boundary layer.Biologists have mainly been concerned with those sections thatare embedded within the leaf, considering the boundary layeras something external, not under the control by biological processes.Well, light is also not controlled 相似文献
16.
Few areas of science have progressed as rapidly, or have hadsuch an impact on public consciousness and governments, as recentadvances in plant biotechnology. These exciting scientific discoveriesand their increasing application are continuing to generateconsiderable economic, social and ethical considerations. Particularconcerns have been expressed, however, about potential foodsafety and environmental impact implications,in particular, of this revolution in biology inagriculture and the food 相似文献
17.
Volume 16 of the Annual Plant Reviews series, compiled by AndrewJ. Fleming, focuses on intercellular communication in plants.This is an extremely interesting book that extensively coversten topics related to cellcell or long-distance communicationin plants. The chapters are written in a clear style and theycompile the most relevant and up-to-date information in a mannerunderstandable for anybody seriously interested in short- andlong-distance intercellular communication. Moreover, besidesblack-and white illustrations and photographs found in all chapters,there are also six separate colour plates. I highly recommendthis book 相似文献
18.
Exercise attenuates {alpha}-adrenergic-receptor responsiveness in skeletal muscle vasculature 总被引:5,自引:0,他引:5
Buckwalter John B.; Naik Jay S.; Valic Zoran; Clifford Philip S. 《Journal of applied physiology》2001,90(1):172-178
Attenuation of sympathetic vasoconstriction(sympatholysis) in working muscles during dynamic exercise iscontroversial. A potential mechanism is a reduction in-adrenergic-receptor responsiveness. The purpose of this study wasto examine 1- and 2-adrenergic-receptor-mediated vasoconstriction inresting and exercising skeletal muscle using intra-arterial infusionsof selective agonists. Thirteen mongrel dogs were instrumentedchronically with flow probes on the external iliac arteries of bothhindlimbs and a catheter in one femoral artery. The selective1-adrenergic agonist (phenylephrine) or the selective2-adrenergic agonist (clonidine) was infused as a bolusinto the femoral artery catheter at rest and during mild and heavyexercise. Intra-arterial infusions of phenylephrine elicited reductionsin vascular conductance of 76 ± 4, 71 ± 5, and 31 ± 2% at rest, 3 miles/h, and 6 miles/h and 10% grade, respectively.Intra-arterial clonidine reduced vascular conductance by 81 ± 5, 49 ± 4, and 14 ± 2%, respectively. The response tointra-arterial infusion of clonidine was unaffected by surgicalsympathetic denervation. Agonist infusion did not affect eithersystemic blood pressure, heart rate, or blood flow in the contralateraliliac artery. 1-Adrenergic-receptor responsiveness wasattenuated during heavy exercise. In contrast,2-adrenergic-receptor responsiveness was attenuated evenat a mild exercise intensity. These results suggest that the mechanismof exercise sympatholysis may involve reductions in postsynaptic-adrenergic-receptor responsiveness. 相似文献
19.
Cell walls have long been recognized as important and uniquefeatures of plant cells, contributing not only to the architectureof plant organs but also to the control of growth, to the exclusionof pathogens and to the production and transmission of signallingmolecules. Gross measurements of plant cell composition establishedlong ago that the plant devotes a large 相似文献
20.
We previously showed that human melanoma, CHO and other cellscan convert ß-xylosides into structural analogs ofganglioside GM3. We have investigated several potential acceptorsincluding a series of n-alkyl-ß-D-glucosides (n =69). All were labeled with 3H-galactose when incubatedwith human melanoma cells. Octyl-ß-D-glucoside (GlcßOctyl)was the best acceptor, whereas neither octyl--D-glucoside norN-octanoyl-methylglucamine (MEGA 8) were labeled. Analysis ofthe products by a combination of chromatographic methods andspecific enzyme digestions showed that the acceptors first receiveda single Galß1,4 residue followed by an 2,3 linkedsialic acid. Synthesis of these products did not affect cellviability, adherence, protein biosynthesis, or incorporationof radio-labeled precursors into glycoprotein, glycolipid orproteoglycans. To determine which ß1,4 galactosyltransferase synthesized Galß1,4GlcßOctyl,we analyzed similar incubations using CHO cells and a mutantCHO line (CHO 761) which lacks GAG-core specific ß1,4galactosyltransferase. The mutant cells showed the same levelof incorporation as the control, eliminating this enzyme asa candidate. Thermal inactivation kinetics using melanoma cellmicrosomes and rat liver Golgi to galactosylate GlcßOctylshowed the same half-life as UDP-Gal:GlcNAc ß1,4 galactosyltransferase,whereas LacCer synthase was inactivated at a much faster rate.We show that GlcßOctyl is a substrate for purifiedbovine milk UDP-Gal:GlcNAc ß1,4 galactosyltransferaseFurthermore, the galactosylation of GlcßOctyl by CHOcell microsomes can be competitively inhibited by GlcNAc orGlcNAcßMU . These results indicate that UDP-Gal:GlcNAcß1,4 galactosyltransferase is the enzyme used forthe synthesis of the alkyl lactosides when cells or rat liverGolgi are incubated with alkyl ß glucosides. alkylglucosides galactosyltransferase glycolipid artificial acceptors 相似文献