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1.
REVIEWS     
Horticultural Aspects of Woolly Aphis Control, together with a Survey of the Literature. By R. M. G reenslade .
Applied Entomology. By H. T. F ernald .
Introduction to Research on Plant Diseases. By A. J. R iker and R egina S. R iker .
The Principal Rots of English Oak. By K. S t . G. C artwright and W. P. K. F indlay .
A Handbook of Rome-Grown Timbers. Department of Scientific and Industrial Research: Forest Products Research.
Fifty Years of Field, Experiments at the Woburn Experimental Station. By Sir J ohn R ussell and Dr J. A. V oelcker .
A Survey of the Agricultural and Waste Lands of Wales. Edited for the Cahn Hill Improvement Scheme by E. G. S tapledon .
English Farming: Past and Present. By The Right Hon. L ord E rnle . New Edition. Edited by Sir A. D. H all .
Use of Leguminous Plants in Tropical Countries as Green Manure, as Cover and as Shade. International Institute of Agriculture.
I. The Experimental Production of Haploids and Polyploids.
II. The South American Potatoes and their Breeding Value.
An Introduction to Comparative Biochemistry. By E. B aldwin .
The March of Science: A First Quinquennial Review , 1931–1935. By Various Authors.  相似文献   

2.
BOOK REVIEWS     
Book reviewed in this article:
Recent Advances in Anaerobic Bacteriology (1987). Edited by S.P. Borriello, J.M. Hardie, B.S. Drasar, B.I. Duerden, M.J. Hudson & R.J. Lysons.
Current Topics in Medical Mycology (1988). Volume 2. Edited by M.R. McGinnis
Advances in Biotechnological Processes Vol. 6 (1986). Edited by Avshalom Mizrahi
The Health Service Use of Ethylene Oxide Sterilization. Edited by G.A.J. Ayliffe, N.F. Cripps, C.E.A. Deverill & R.H. George
Biotechnology of Waste Treatment and Exploitation (1987). Edited by John M. Sidwick & Roger S. Holdom
Animal Cell Technology, Principles and Products (1987). By M. Butler
Methods in Aquatic Bacteriology (1988). Edited by B. Austin
Homeostatic Mechanisms in Microorganisms (1988). Edited by R. Whittenbury, G.W. Gould, J.G. Banks & R.G. Board
Lecture Notes on Medical Virology (1987). By D.J. Jeffries
Urinary Tract Infections (1987). By J.R. Dalton & E.J. Bergquist
Quality Control and Assurance in Clinical Laboratories (1988). Edited by A.D. Farr
Disinfection in Veterinary and Farm Animal Practice (1987). Edited by A.H. Linton, W.B. Hugo & A.D. Russell  相似文献   

3.
Metachromatic leukodystrophy is a lysosomal storage disorder caused by the deficiency of arylsulfatase A. This leads to the accumulation of 3-O-sulfogalactosylceramide, which results in severe demyelination. Here we describe a novel non-sense mutation W124ter and two disease-causing missense mutations E382Q and C500F in arylsulfatase A gene. Another so far unknown allele harbors three sequence alterations: two polymorphisms (N350S, R496H) and a missense mutation (R288H). The R288H substitution and the N350S polymorphism have previously been found on one allele together with a polymorphism in a polyadenylation signal characteristic for the arylsulfatase A pseudodeficiency allele. The R496H has been shown to occur on another allele. The presence of the R288H, N350S, and R496H substitution on one allele in the absence of the polyadenylation site polymorphism shows that this allele has probably arisen by recombination between the nucleotides of codon 350 and 496.  相似文献   

4.
Three high-resolution crystal structures of Cd(II)-substituted carboxypeptidase A (CPA) have been determined by X-ray diffraction from crystals prepared in three different buffer systems to assess the effect of pH and ionic strength on the Cd(II) coordination geometry. All crystallize in the space group P2(1) with identical cell dimensions. Cd-CPA(7.5): Cd(II)-substituted CPA prepared at pH 7.5 with [Cl(-)]=2 mM determined to 1.70 A resolution ( R=17.4% and R(free)=19.8%); Cd-CPA(5.5): Cd(II)-substituted CPA prepared at pH 5.5 with [Cl(-)]=2 mM to 2.00 A resolution ( R=16.1% and R(free)=18.6%); Cd-CPA(7.5)-Cl: Cd(II)-substituted CPA prepared at pH 7.5 with [Cl(-)]=250 mM to 1.76 A resolution ( R=16.7% and R(free)=17.8%). No noticeable structural changes were observed between the three structures. Two water molecules coordinate to Cd(II), in contrast to the single water molecule coordinating to Zn(II) in the Zn-CPA structure. No binding sites for anions could be identified, even in the structure with a high concentration of chloride ions. It is suggested that the anion inhibition is due to weak outer-sphere association of Cl(-) ions at several binding sites, shielding the strong positive charge distribution at the surface of the protein near the active site. Based on structural data and a sequence alignment of 18 non-redundant carboxypeptidases, a more elaborate version of the earlier reaction model is proposed that also addresses the transport of water to and from the active site. Conserved residues whose function was not addressed previously delineate the proposed pathways used in the transport of water during catalysis.  相似文献   

5.
Three sweet receptor genes are clustered in human Chromosome 1   总被引:3,自引:0,他引:3  
Liao  Jiayu  Schultz  Peter G. 《Mammalian genome》2003,14(5):291-301
A search of the human genome database led us to identify three human candidate taste receptors, hT1R1, hT1R2, and hT1R3, which contain seven transmembrane domains. All three genes map to a small region of Chromosome (Chr) 1. This region is syntenous to the distal end of Chr 4 in mouse, which contains the Sac (saccharin preference) locus that is involved in detecting sweet tastants. A genetic marker, DVL1, which is linked to the Sac locus, is within 1700 bp of human T1R3. Recently, the murine T1Rs and its human ortholog have been independently identified in combination as sweet and umami receptors near the Sac locus. All three hT1Rs genes are expressed selectively in human taste receptor cells in the fungiform papillae, consistent with their role in taste perception.  相似文献   

6.
Three novel mutations in Japanese patients with 21-hydroxylase deficiency   总被引:2,自引:0,他引:2  
OBJECTIVE: This study analyzed the mutation of 21-hydroxylase deficiency (21-OHD) in 36 unrelated Japanese patients with congenital adrenal hyperplasia (CAH). METHODS: All the exons of the functional CYP21 gene (CYP21A2) were analyzed by polymerase chain reaction (PCR) and PCR direct sequencing. RESULTS: Apparent gene deletions and conversions were present in 23.6% of the 72 CAH alleles, in which the most frequent mutation was the IVS2-13 A/C>G (27.8%), followed by I172N (26.3%), consistent with the frequencies reported for other countries. Previously described mutations were not present in three unrelated cases. Sequence analysis of the complete functional CYP21A2 gene revealed three, not yet described mutations that represent a common pseudogene sequence. These three putative novel mutations are located in exon 1 (M1I), in exon 5 (1210-1211insT), and in exon 3 (R124H). CONCLUSIONS: In this study, we have identified three putative novel mutations. It remains to be determined whether these three mutations are responsible for the significant number of as yet uncharacterized CAH patients in Japan.  相似文献   

7.
Richter R  Basar S  Koch A  König WA 《Phytochemistry》2005,66(23):2708-2713
The volatile constituents of the roots of Panax ginseng C.A. Meyer have been investigated after hydrodistillation and analysed by means of different analytical methods. Besides several compounds already known three sesquiterpene hydrocarbons have been isolated from the essential oil. Structure elucidation of the bicyclic panaxene as well as of the tricyclic panaginsene and ginsinsene was performed by MS and NMR. They have been identified as (1R*,2S*,5S*)-2-ethenyl-1(1-methylethenyl)-2,6,6-trimethylbicyclo[3.2.0]heptane (panaxene), (1S*,8S*,11R*)-4,7,7,11-tetramethyltricyclo[6.3.0.0(1,5)]undec-4-ene (panaginsene) und (1R*,6R*,7R*)-3,7,10,10-tetramethyltricyclo[4.3.2.0(2,6)]undec-2-ene (ginsinsene).  相似文献   

8.
Antimutagenic substances were purified from a culture supernatant of Lactobacillus plantarum KLAB21 cells isolated from kimchi, a Korean traditional fermented vegetable, and their characteristics were investigated. The antimutagenic substances were separated into two fractions by DEAE-cellulose ion-exchange column chromatography, which were designated the R1 and R2 fractions. The R1 fraction was then divided into two fractions again by Sephadex G200 gel filtration chromatography, and the fractions were designated R1-1 and R1-2. All three fractions were further purified using a Sepharose CL-6B gel filtration column. All the purified fractions were successfully stained with fuchsin as well as Coomassie brilliant blue, suggesting that they are glycoproteins. The purified fractions were confirmed to possess antimutagenic activity against N-methyl-N'-nitro-N-nitrosoguanidine on Salmonella enterica serovar Typhimurium TA100 cells. Their molecular masses were determined to be 16 (R1-1), 11 (R1-2), and 14 (R2) kDa on the Sepharose CL-6B column. Total sugar contents were 8.4% (R1-1), 7.3% (R1-2), and 9.4% (R2). The amino acid compositions of the fractions were different from each other; the major amino acids were glutamic acid (21.5%) and phenylalanine (17.1%) in the R1-1 fraction and glycine (41.3%) in the R1-2 fraction, but valine (31%) and phenylalanine (22.6%) were the major amino acids in the R2 fraction.  相似文献   

9.
Previous studies have suggested that the helical repeat formed by residues 143;-164 of apolipoprotein A-I (apoA-I) contributes to lecithin:cholesterol acyltransferase (LCAT) activation. To identify specific polar residues involved in this process, we examined residue conservation and topology of apoA-I from all known species. We observed that the hydrophobic/hydrophilic interface of helix 143;-164 contains a cluster of three strictly conserved arginine residues (R149, R153, and R160), and that these residues create the only significant positive electrostatic potential around apoA-I. To test the importance of R149, R153, and R160 in LCAT activation, we generated a series of mutant proteins. These had fluorescence emission, secondary structure, and lipid-binding properties comparable to those of wild-type apoA-I. Mutation of conserved residues R149, R153, and R160 drastically decreased LCAT activity on lipid-protein complexes, whereas control mutations (E146Q, D150N, D157N, R171Q, and A175R) did not decrease LCAT activity by more than 55%. The markedly decreased activities of mutants R149, R153, and R160 resulted from a decrease in the maximal reaction velocity V(max) because the apparent Michaelis-Menten constant K(m) values were similar for the mutant and wild-type apoA-I proteins.These data suggest that R149, R153, and R160 participate in apoA-I-mediated activation of LCAT, and support the "belt" model for discoidal rHDL. In this model, residues R149, R153, and R160 do not form salt bridges with the antiparallel apoA-I monomer, but instead are pointing toward the surface of the disc, enabling interactions with LCAT. - Roosbeek, S., B. Vanloo, N. Duverger, H. Caster, J. Breyne, I. De Beun, H. Patel, J. Vandekerckhove, C. Shoulders, M. Rosseneu, and F. Peelman. Three arginine residues in apolipoportein A-I are critical for activation of lecithin:cholesterol acyltransferase J. Lipid Res. 2001. 42: 31;-40.  相似文献   

10.
Antimutagenic substances were purified from a culture supernatant of Lactobacillus plantarum KLAB21 cells isolated from kimchi, a Korean traditional fermented vegetable, and their characteristics were investigated. The antimutagenic substances were separated into two fractions by DEAE-cellulose ion-exchange column chromatography, which were designated the R1 and R2 fractions. The R1 fraction was then divided into two fractions again by Sephadex G200 gel filtration chromatography, and the fractions were designated R1-1 and R1-2. All three fractions were further purified using a Sepharose CL-6B gel filtration column. All the purified fractions were successfully stained with fuchsin as well as Coomassie brilliant blue, suggesting that they are glycoproteins. The purified fractions were confirmed to possess antimutagenic activity against N-methyl-N′-nitro-N-nitrosoguanidine on Salmonella enterica serovar Typhimurium TA100 cells. Their molecular masses were determined to be 16 (R1-1), 11 (R1-2), and 14 (R2) kDa on the Sepharose CL-6B column. Total sugar contents were 8.4% (R1-1), 7.3% (R1-2), and 9.4% (R2). The amino acid compositions of the fractions were different from each other; the major amino acids were glutamic acid (21.5%) and phenylalanine (17.1%) in the R1-1 fraction and glycine (41.3%) in the R1-2 fraction, but valine (31%) and phenylalanine (22.6%) were the major amino acids in the R2 fraction.  相似文献   

11.
本文对三种毒菌的化学成分进行了研究。从光盖伞(Psilocybe spp)分离鉴定了4个化合物,经波谱分析鉴定为:(22E,24R)-麦角甾-7,22-二烯-3β-十八烷酸酯(1)、β-胡萝卜苷(2)、(22E,24R)-5α,6α-环氧麦角甾-8,22-二烯-3β,7α-二醇(3)、色氨酸(4);从假褐云斑鹅膏(Amanita pseudoporphyria)分离鉴定了4个化合物:(22E,24R)-3β-羟基-5α,8α-过氧化麦角甾-6,22-二烯(5)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(6)、1-O-β-D-吡喃葡萄糖基-(2S,3R,4E,8E,2′R)-2-N-(2′-羟基棕榈酰)-9-甲基-4,8-脱氢鞘氨醇(7)、1-O-β-D-吡喃葡萄糖基-(2S,3R,4E,8E,2′R)-2-N-(2′-羟基十八烷酰)-9-甲基-4,8-脱氢鞘氨醇(8);大青褶伞(Chlorophyllum molybdites)发酵菌丝体分离鉴定了4个化合物:5、6、(22E,24R)-5α,6α-环氧麦角甾-8(14),22-二烯-3β,7α-二醇(9)、(22E,24R)-麦角甾-7,22-二烯-3β-醇(10)。除化合物9外其它化合物均为首次从以上相应毒菌中分离得到。  相似文献   

12.
Three new species of Rubus subgenus Rubus series Pallidi from Spain are described, mapped and illustrated: R. Cyclops, R. castroviejoi and R. urbionicus.  相似文献   

13.
Missense mutations in the pore-forming human alpha(1A) subunit of neuronal P/Q-type Ca(2+) channels are associated with familial hemiplegic migraine. We studied the functional consequences on P/Q-type Ca(2+) channel function of three recently identified mutations, R583Q, D715E, and V1457L after introduction into rabbit alpha(1A) and expression in Xenopus laevis oocytes. The potential for half-maximal channel activation of Ba(2+) inward currents was shifted by > 9 mV to more negative potentials in all three mutants. The potential for half-maximal channel inactivation was shifted by > 7 mV in the same direction in R583Q and D715E. Biexponential current inactivation during 3-s test pulses was significantly faster in D715E and slower in V1457L than in wild type. Mutations R583Q and V1457L delayed the time course of recovery from channel inactivation. The decrease of peak current through R583Q (30.2%) and D715E (30. 1%) but not V1457L (18.7%) was more pronounced during 1-Hz trains of 15 100-ms pulses than in wild type (18.2%). Our data demonstrate that the mutations R583Q, D715E, and V1457L, like the previously reported mutations T666M, V714A, and I1819L, affect P/Q-type Ca(2+) channel gating. We therefore propose that altered channel gating represents a common pathophysiological mechanism in familial hemiplegic migraine.  相似文献   

14.
Waste management in the leaf-cutting ant Atta colombica   总被引:1,自引:0,他引:1  
Unlike most leaf-cutting ants, which have underground wastedumps, the leaf-cutting ant Atta colombica dumps waste in aheap outside the nest. Waste is hazardous, as it is contaminatedwith pathogens. We investigated the organization of the workforceinvolved in outside-nest tasks (foraging, waste disposal) andquantified task switching and heap location to test hypothesesthat these tasks are organized to minimize contact between the heap and foraging entrances and trails. Waste management isan important task: 11% of externally working ants were eithertransporting waste or manipulating waste on the heap, and theother 89% were foragers. There is strict division of laborbetween foragers and waste workers, with no task switching.Waste management also has division of labor and is undertakenby transporters that carry waste to the heap margins and heapworkers that manage the heap. Waste heaps are always locateddownhill from nest entrances. The distance to the waste heapis positively related to colony size and negatively relatedto slope. Foraging trails avoid the heap, with 92% of trailsgoing away from the heap. This avoidance behavior is costly,increasing foraging trail length by at least 6%. Waste managementin A. colombica is a sophisticated system that encompassesboth work and spatial organization. This organization is probablyadaptive in reducing disease transmission. Division of labor separates waste management from foraging, reducing the likelihoodof foragers becoming contaminated with waste. The downhilllocation of heaps reduces waste entering entrances during rain.The orientation of foraging trails reduces the possibilityof foragers becoming accidentally contaminated with waste.  相似文献   

15.
摘要 目的:探讨circPPP1R12A(circ_0000423)调控p53信号通路对骨关节炎(osteoarthritis,OA)中软骨细胞增殖和凋亡的影响。方法:采用qRT-PCR检测circPPP1R12A在OA软骨细胞中的表达水平。在OA软骨细胞中分别转染oe-circPPP1R12A和sh-circPPP1R12A后,采用CCK-8检测细胞增殖情况;免疫荧光检测Ki-67阳性细胞表达率;流式细胞术检测细胞凋亡情况;qRT-PCR检测Ki-67和p53表达水平;Western Blot检测Cleaved-caspase3、P53、BCL-2和BAX的表达水平。结果:OA软骨细胞中circPPP1R12A的表达水平明显高于正常软骨细胞。过表达circPPP1R12A能够抑制OA软骨细胞增殖和促进细胞凋亡,通过上调p53表达激活p53信号通路,低表达circPPP1R12A能够促进OA软骨细胞增殖和抑制细胞凋亡,通过下调p53表达阻滞p53信号通路。在OA软骨细胞中同时低表达circPPP1R12A和过表达p53能够反转单独低表达circPPP1R12A对OA软骨细胞增殖和凋亡的影响。结论:circPPP1R12A在OA软骨细胞中明显高表达,circPPP1R12A能够通过激活p53信号通路抑制骨OA软骨细胞增殖和促进软骨细胞凋亡。circPPP1R12A可能成为OA治疗的干预靶点。  相似文献   

16.
Receptor tyrosine kinases (RTKs) and Notch (N) proteins are different types of transmembrane receptors that transduce extracellular signals and control cell fate. Here we examine cell fate specification in the Drosophila retina and ask how N acts together with the RTKs Sevenless (Sev) and the EGF receptor (DER) to specify the R7 photoreceptor. The retina is composed of many hundred ommatidia, each of which grows by recruiting surrounding, undifferentiated cells and directing them to particular fates. The R7 photoreceptor derives from a cohort of three cells that are incorporated together following specification of the R2-R5 and R8 photoreceptors. Two cells of the cohort are specified as the R1/6 photoreceptor type by DER activation. These cells then activate N in the third cell (the R7 precursor). By manipulation of N and RTK signaling in diverse combinations we establish three roles for N in specifying the R7 fate. The first role is to impose a block to photoreceptor differentiation; a block that DER activation cannot overcome. The second role, paradoxically, is to negate the first; Notch activation up-regulates Sev expression, enabling the presumptive R7 cell to receive an RTK signal from R8 that can override the block. The third role is to specify the cell as an R7 rather than an R1/6 once RTK signaling has specified the cells as a photoreceptor. We speculate why N acts both to block and to facilitate photoreceptor differentiation, and provide a model for how N and RTK signaling act combinatorially to specify the R1/6 and R7 photoreceptors as well as the surrounding non-neuronal cone cells.  相似文献   

17.
REVIEWS     
Laboratory Methods for Work with Plant and Sod Nematodes. Technical Bulletin no. 2, by Dr T. GOODEY.
The Establishment of Vegetation on Industrial Waste Land. By R. 0. WHYTE and J. W. B. SISAM.
La Vatiation. By É. GUYENOT.
Genetics, Palaeontology and Evolution. Edited by GLENN L. JEPSON, GEORGE GAYLORD SIMPSON and ERNST MAYR.
Principles of Human Genetics. By CURT STERN.  相似文献   

18.
Summary Fall field patulin applications (500 µg/g of soil) to Cheyenne winter wheat seedlings at growth stages 0, 1, and 2, decreased germination, plant growth, winter survival, and tillering. Decreased tillering decreased the number of heads and grain yield. Spring patulin application of 250 and 500 µg/g of soil to wheat at growth stages 6, 7, 8, 9, and 10 decreased yields by decreasing the number of heads, kernels per head, and kernel weight. With fall patulin applications, yields were decreased more when patulin was applied near seeding. Spring patulin applications to wheat during sensitive heading stages decreased yield the most.Stages of wheat growth especially susceptible to patulin are the germination, stem-elongation, and flowering, which occur during the fall and spring when soil Penicillium urticae Bainier numbers are maximun and patulin has been extracted from the soil.Contribution from the Soil, Water, and Animal Waste Management Research Unit, North Central Region, Agricultural Research Service, U.S. Department of Agriculture, in cooperation with the Nebraska Agricultural Experiment Station, Lincoln. Published as Paper No. 4071, Journal Series, Nebraska Agricultural Experiment Station.Microbiologist, USDA, A.R.S. University of Nebraska, Lincoln; Soil Scientist, USDA, A.R.S. Fort Collins, Colorado; and Microbiologist, USDA, A.R.S. University of Nebraska, Lincoln, respectively.  相似文献   

19.
Cellular fatty acid analysis was employed to differentiate three varieties of Rhizoctonia circinata ; var. circinata , var. oryzae and var. zeae . Eight fatty acids including myristic (14 : 0), pentadecanoic (15 : 0), palmitic (16 : 0), palmitoleic (16 : 1  cis 9), stearic (18 : 0), oleic (18 : 1  cis 9), linoleic (18 : 2  cis 9,12) and linolenic (18 : 3  cis 9,12) acids were present in isolates of all three varieties of R. circinata . Heptadecanoic acid (17 : 0) was detected in isolates of R. circinata var. zeae but not in isolates of R. circinata var. circinata or R. circinata var. oryzae . Palmitic, oleic and linoleic acids were the major fatty acids found, comprising 94–98% of the whole-cell fatty acid content. The remaining fatty acids were present in small amounts. Based on the composition (%) of fatty acids, isolates of R. circinata var. circinata , R. circinata var. oryzae and R. circinata var. zeae were clearly differentiated into three groups as shown by principal component and cluster analyses. This finding agrees well with the grouping of R. circinata into three varieties based on differences in colony morphology of the vegetative state. In principal component and cluster analysis, isolates of R. circinata var. circinata from Japan and Alaska were indistinguishable.  相似文献   

20.
One of the more promising processes for the energetic transformation of waste is the anaerobic digestion of the Organic Fraction of Municipal Solid Waste (OFMSW). An experimental campaign was carried out on three different samples of OFMSW from Waste Separation (WS), one as received and two obtained after mechanical treatment (squeezing): OFMSW slurry (liquid fraction) and OFMSW Waste (residual solid fraction). Anaerobic Biogasification Potential (ABP) and anaerobic digestion tests (AD) were carried out, investigating the effects of inoculum and pH. The OFMSW Waste was also examined to evaluate the possibility to dispose of it in a landfill. Results showed that OFMSW slurry must be diluted and inoculated and that pH control in the start up phase is essential, in order to have significant biogas productions. OFMSW as received did not show a significant biogas production, while OFMSW Waste showed suitable characteristics for landfill disposal, except for Dissolved Organic Carbon.  相似文献   

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