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1.
This paper describes a simulation problem, motivated by the study of glaucoma, a very serious and widespread ocular illness. To ascertain whether a patient suffers from glaucoma, a perimetric test is done, but the evolution of the disease is very slow, and large longitudinal sets of tests taken on the same patient are needed to study its evolution, to analyze the efficiency of existing methods to detect the progression of glaucoma and to develop new ones. Simulation can be a very useful procedure to get appropriate data sets to work with. Our aim in this work is to simulate several VFs in a healthy patient to reflect his evolution in time. We use a spatio‐temporal model to simulate from, taking into account the correlation existing between the observed (or simulated) values in space and time. Two different simulation procedures (unconditional and conditional) are studied, and applied to obtain the simulations we are interested in. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
2.
3.
Abstract. Contrary to current assumptions, the reflex blood of two-spot ladybirds, Adalia bipunctata , and seven-spot ladybirds, Coccinella septempunctata , contains haemocyte-like cells. Furthermore, DNA can be extracted and amplified from coccinellid reflex blood, confirming the presence of haemocyte-like cells and demonstrating a nondestructive method of DNA extraction. 相似文献
4.
Raphael Chijioke Njoku 《Dialectical Anthropology》2007,31(1-3):45-64
It is difficult to completely understand the life history of an intellectual excluding an understanding of his family upbringing
and formative years. Family upbringing and childhood environment, often the less known part of a life history, play crucial
roles in shaping the ideas and values individuals espouse in their adult life. Notwithstanding, this paper is not concerned
with Don C. Ohadike’s childhood. It rather focuses on the professional career of our able historian – that is the part of
his life as revealed by his most outstanding published writings. Ohadike’s published works contain a wellspring of idioms
that tell much about his values, quality of mind, and his mission as an African historian. Ohadike was a humanist, an African
patriot, and a nationalist crusader. His entire philosophy centered on safeguarding his African identity in an emergent world
of cultural imperialism.
The funds for this research were provided by a NEH-funded fellowship at the Schomburg Center, New York in the Spring of 2007.
I owe a lot of gratitude to Professor John McLeod and Dean Blaine Hudson for granting me the extra incentives to pursue my
research in New York. While all errors and misinterpretations are mine, I wish to thank the editors and anonymous reviewers
for Journal of Dialectical Anthropology for their perspective comments and suggestions on earlier drafts of this paper. 相似文献
5.
Ethylene treatment (approx. 20 l ·1-1 in air for 2 d) of tobacco (Nicotiana tabacum L. cv. Havana 425) plants markedly increases the endo--1,3-glucanase (EC 3.2.1.39) content of leaves. The antigenic form of the enzyme induced is the same one whose production is blocked by treating cultured cells with combinations of auxin (1.1 · 10-5 M -naphthaleneacetic acid) and cytokinin (1.4 · 10-6 M kinetin). Evidence is presented that cultured tobacco cells require ethylene for -1,3-glucanase accumulation: i) ethylene treatment increased the accumulation of \-1,3-glucanase in callus tissues >10 d after subculturing and in cell-suspension cultures; ii) callus tissues can produce ethylene; iii) conditions known to inhibit ethylene production (1 mM CoCl2; 33° C treatment) or ethylene action (approx. 1.6 mmol · 1-1 norbornadiene in air) inhibited -1,3-glucanase accumulation by callus tissues treated for 4 d following subculturing; and, these inhibitory effects were prevented by exogenous ethylene. Combinations of auxin and cytokinin blocked ethylene-induced accumulation of -1,3-glucanase by cell-suspension cultures. The results favor a model in which ethylene induces results favor a model in which ethylene induces 1,3-glucanase accumulation, and auxin and cytokinin inhibit this induction process.Abbreviations NAA
-naphthaleneacetic acid
- NDE
norbornadiene 相似文献
6.
Killing of Escherichia coli cells modulated by components of the stability system ParD of plasmid R1
Alicia Bravo Sagrario Ortega Gertrudis de Torrontegui Ramón Díaz 《Molecular & general genetics : MGG》1988,215(1):146-151
Summary The proteins P10 and P12 have been shown to be gene products of a new stability system, ParD, of plasmid R1. It is now shown that an R1 miniplasmid, pAB112, carrying a trans-complementable amber mutation in the gene of the P10 protein, is lethal for the host in the absence of suppression. This lethal effect is suppressed in a supF background and also by deletions in pAB112 that affect the gene of the P12 protein. These data indicate that the P12 protein has a lethal effect on the host and that this effect is neutralized by the P10 protein. The possibility that the stabilization conferred by the ParD system could be due to a counterselection, mediated by P12, of cells that lose the plasmid at cell division, is discussed. 相似文献
7.
8.
Personnel records kept by military units of American colonials during the French and Indian War (1755-1763) are analyzed for relationships between environmental factors and stature. A robust American economy and direct access to high-quality food were apparently critical to tallness of this white American male sample. American-born men were taller at all ages than those who had migrated from Europe. January temperatures, rural versus urban birth, and ethnicity also showed stature relationships within the American-born group; thermal effects were by far the strongest of the non-nutritional factors. 相似文献
9.
Photoacoustic and fluorescence measurements of the chilling response and their relationship to carbon dioxide uptake in tomato plants 总被引:5,自引:0,他引:5
The response of tomato plants to various chilling treatments was studied using two approaches for the measurement of photosynthetic activity. One involved the use of a portable fluorometer for the measurement of in-vivo chlorophyll fluorescence, while the other employed a newly introduced photoacoustic system which allowed changes in oxygen evolution to be followed in a leaf disc. A strong correlation was found between results obtained by each system and those obtained by a conventional open gas-exchange system for the determination of CO2 uptake. Both systems of measurements could readily distinguish between the effects of chilling in the dark (at 3° C for 18 h) and chilling at high photon flux density (2000 mol m-2 s-1 for 5h at 5° C). Chilling in the dark had practically no effect on the quantum yield of oxygen evolution, chlorophyll fluorescence or CO2 uptake, while chilling at excessively high photon flux density resulted in a sharp reduction (50–70%) in the quantum yields obtained. The results support the view that photosystem II cannot be the primary site of damage by chilling in the dark, although it is significantly affected by chilling at high light intensity.Abbreviations DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- PA
photoacoustic
- PFD
photon flux density
- PSII
photosystem II 相似文献
10.
Yohei Hashimoto Hiroyuki Ishizone Midori Moriyasu Kazuko Kawanishi Atsushi Kato Masaru Ogura 《Phytochemistry》1984,23(8):1807-1808
Three oleanane triterpenes were isolated from the roots of Periandra dulcis,and identified as 3β-hydroxy-25-al-olean-18-en-30-oic acid (periandric acid I), 3β-hydroxy-25-al-olean-12-en-30-oic acid (periandric acid II) and 3-oxo-25-hydroxy-olean-12-en-30-oic acid. The former two compounds (periandric acids I and II) were identical with the aglycones obtained by hydrolysis of periandrin I and II, respectively and the latter one was a new triterpene. 相似文献