共查询到20条相似文献,搜索用时 15 毫秒
1.
Gitte Petersen Ole Seberg Argelia Cuenca Dennis W. Stevenson Marcela Thadeo Jerrold I. Davis Sean Graham T. Gregory Ross 《Cladistics : the international journal of the Willi Hennig Society》2016,32(2):141-159
A phylogenetic analysis of the early branching lineages of the monocotyledons is performed using data from two plastid genes (rbcL and matK), five mitochondrial genes (atp1, ccmB, cob, mttB and nad5) and morphology. The complete matrix includes 93 terminals representing Acorus, the 14 families currently recognized within Alismatales, and numerous lineages of monocotyledons and other angiosperms. Total evidence analysis results in an almost completely resolved strict consensus tree, but all data partitions, genomic as well as morphological, are incongruent. The effects of RNA editing and potentially processed paralogous sequences are explored and discussed. Despite a decrease in incongruence length differences after exclusion of edited sites, the major data partitions remain significantly incongruent. The 14 families of Alismatales are all found to be monophyletic, but Acorus is found to be included in Alismatales rather than being the sister group to all other monocotyledons. The placement is strongly supported by the mitochondrial data, atp1 in particular, but it cannot be explained as an artifact caused by patterns of editing or by sampling of processed paralogues. 相似文献
2.
A A Ne?fakh 《Ontogenez》1985,16(1):15-25
Two closely related controversial problems are discussed: whether the developmental processes can be reduced to the synthesis of polypeptides encoded in DNA, and whether the information in DNA is equivalent to that in the adult organism. Critically considered are the ideas that DNA is only responsible for the protein synthesis, whereas morphogenesis proceeds independently and according to epigenetic regularities of its own. It is stated that development is the realization of genetic information in which more elementary (molecular) processes unambiguously determine a more complex cellular level which in its turn determines morphogenesis of tissues and organs. Various mechanisms of the appearance of new information in the course of development are considered. The statement is made that new information concerns only some individual characters of the organism, whereas most of information that determines the process of development and the structure of the adult organism is created in the course of evolution, is stored in DNA and inherited. 相似文献
3.
Airoldi M Gennaro G Giomini M Giuliani AM Giustini M 《Journal of biomolecular structure & dynamics》2011,29(3):585-594
When the model polynucleotide poly(dG-dC)?poly(dG-dC) [polyGC] is titrated with a strong acid (HCl) in unbuffered aqueous solutions containing the chlorides of the alkali metals in the concentration range 0.010?M-0.600?M, two transitions in the absorbance vs. pH plots are evidenced, characterized by the constants pK(a(?)) and pK(a(?)). The limiting values at infinite saline concentrations of these two constants, namely pK(∞)(a(?)) and pK(∞)(a(?)) obtained making use of the "one site saturation constant" equation or, in turn, of the double logarithmic plot: pK(a) vs. log([salt]?1), exhibit a clear dependence on the nature of the cations. The effects of the different alkali cations on the pK(∞)(a) values follow the Hofmeister series. In fact, the pK(∞)(a(?)) and the pK(∞)(a(?)) values are smaller for Li+ and Na+ than for Rb+ and Cs+, with K+ at the border between the two, showing that the transitions require higher concentrations of protons to occur in the presence of high concentrations of the cosmotropic ions. 相似文献
4.
B. Gray 《Insectes Sociaux》1971,18(2):71-80
Myrmecia dispar (Clark) is found in the drier inland areas of New South Wales and southern Queensland in Australia. Its nests, which are situated adjacent to trees, have a distinctive structure of simple architecture. The composition of the colonies varies seasonally with little or no brood production during the colder months. Colony founding probably takes place in March, April, and/or May. Several myrmecophiles are found in nests ofM. dispar, and some of these are present in relatively large numbers. 相似文献
5.
《International Journal of Insect Morphology and Embryology》1997,26(2):139-147
The present work reports on a neuroanatomical study of the butterfly Pararge aegeria (Lepidoptera : Satyridae) focusing on the lamina ganglionaris underlying two different regions of the retina of the compound eye: the dorsal rim area and the large dorsal region. No differences between both lamina regions, concerning the structure of the cartridges and the morphology of the identified neurons, could be detected. After passing the basement membrane, the visual cell axons are organized in retinotopic bundles (pseudocartridges), in which the axons of the 9 visual cells (V1 and 5, D2, 4, 6, 8, H3 and 7, B9) are arranged in the same way as in the retina. In the pseudocartridge there are no synaptic contacts. Before entering the lamina cartridge, the bundles rotate 90 °. The cartridges are joined by the fibres of 4 monopolar cells (L1, L2, L3 and L4), which could be identified and located inside the lamina cartridges in serial EM-sections. Golgi impregnations revealed the morphology of these fibres. Thus, the regional specialization of the retina (dorsal rim area and large dorsal region) does not seem to be reflected at the level of the first visual neuropil. Additionally, the cartridges of both lamina regions were investigated qualitatively for synaptic contacts among fibres. In addition to monadic chemical synapses and multiple contact synapses with presynaptic ribbons, cell contacts are also facilitated by invaginations and bridges. These cellular interactions and their functional implications are discussed. 相似文献
6.
J Moens 《Archives internationales de physiologie et de biochimie》1975,83(3):443-451
The ionic regulation of the haemolymph of larvae of Aeshna cyanea (Müller) was studied by means of two types of experiments. In the first the change in internal ionic composition was followed as a function of the time spent in a given experimental medium. These experiments led to the conclusion that: 1. the haemolymph composition does not change when larvae are starved in tap water for 10 days; 2. the haemolymph ionic concentrations (Na and Cl) have initial marked increase when the animals are kept in hypertonic media of diluted sea water; after 80 hours however, both concentrations stay constant. In a second series of experiments the internal ionic concentration was compared to a series of different concentrations of external media. From this, the relation between the internal and external ionic concentration was elaborated : in hypotonic media the internal Na and Cl concentrations stay constant, in hypertonic media there is a parallelism between the increase of the external concentration and haemolymph concentration, the internal Na concentration being always slightly hypertonic, the Cl concentration markedly hypotonic. Finally, when larvae are placed in glass distilled water, the internal Na and Cl concentrations begin to decrease after 60 hours. 相似文献
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WANG Wen-Tsai 《植物分类学报:英文版》2000,38(5):401-429
(1) The systematic positions of Clematis potaninii Maxim., C . heynei Rau, C. trichotoma Nakai, C. apiculata Hook. f. & Thoms, C. theobromina Dunn, C. sigensis Engler,C. hedysarifolia DC., and C. dissecta Baker, and the specific status of C. trifida Hook, C.pimpinellifolia Hook., C. oligophylla Hook., and Clematopsis lineariloba Hutch. are discussed; (2) New classifications for Clematis parviloba Gardn. & Champ., C. puberula Hook. f. & Thoms., and sect. Naraveliopsis Hand.-Mazz. are provided; (3) Clematis subsect. Potaninianae M. Johnson, C. heynei M. Johnson, C. petelotii Gagnep. and some other names are reduced to synonymy; (4) Two subsections, 4 series, 4 species, and 4 varieties are described as new; (5)Four new ranks and 4 new combinations are made. 相似文献
9.
WANG Wen-Tsai 《植物分类学报:英文版》2001,39(1):1-19
(1) Clematis taiwaniana Hayata, C. grata Wall. var. ryukiuensis Tamura, C . sikkimensis (Hook. f. & Thoms. ) Drumm. ex Burkill, C. connata DC. var. bipinnata M. Y. Fang,
C. kilungensis W. T. Wang & M. Y. Fang etc. are reduced to synonymy. (2) New classifications
for sect. Tubulosae Decne., C. siamensis Drumm. & Craib and C. connata DC. are proposed.
(3) 3 series, 3 species and 4 varieties are described as new. (4) 6 new combinations and 3 newranks are made. 相似文献
10.
WANG Wen-Tsai 《植物分类学报:英文版》2000,38(6):497-514
(1) The evolutionary trends of sepals and stamens of the genus Clematis are discussed;
(2) New classifications for sect. Cheiropsis DC. and sect. Aspidanthera Spach are proposed; (3)
One subsection, 13 series, 5 species and 4 varieties are described as new; (4) Six new ranks and2 new combinations are made. 相似文献
11.
WANG Wen-Tsai 《植物分类学报:英文版》2000,38(4):305-336
( 1 ) Some taxonomical problems of the genus Clematis mainly about misidentifications
are discussed, and some treatments including the reinstatement of Clematis montana var. brevifoliola Kuntze, C. apiifolia var. biternata Makino, C. subumbellata Kurz, C. goudotiana Planch.
& Triana, C. insidiosa Baill., C. kockiana Schneid. and C. longicauda A. Rich., and the reduction of subsect. Africanae M. Johnson, C. umbellifera Gagnep., C. pubescens Benth., C.
rhodocarpa Rose, C. edentata Baker, C. stoltzi Engler, C. tibetana ssp. vernayi var. dentata
Grey-Wilson, C. clarkeana var. stenophylla Hand.-Mazz., C. subfalcata Pei ex M.Y. Fang,
C. angustifoliola W. T. Wang, C. dasyandra var. polyantha Finet & Gagnep. etc are given.
(2) The new diagnoses for the two subsections of the sect. Meclatis are provided; C. sericea H.B.
K. ex DC. and C. grossa Benth. are treated as two varieties of one species; and a new classification of the infraspecific taxa of C. hirsuta Perr & Guill. is made. (3) one subsection, one series,
eight species and one variety are described as new. (4) The new occurrences of C. montana var.
brevifoliola Kuntze in southern Xizang, China, Nepal, Bhutan and northern Myanmar, C. burmanica Lace in southwestern Yunnan, C. armandii Franch. in Assam, India and northern Myanmar,and C. yui W. T. Wang in northern Myanmar are reported. 相似文献
12.
Edwards AW 《Theoretical population biology》2000,58(3):255-257
In three publications in 1883 and 1884 Carl Düsing of Jena gave a mathematical account of the influence of natural selection on the sex ratio based on the same argument that Darwin had advanced in The Descent of Man (1871). The argument thus became quite well known, being included in the principal books on the subject around the turn of the century, as well as in the Encyclopaedia Britannica, references to Düsing being given. By 1930, when Fisher gave a verbal account of the argument in The Genetical Theory of Natural Selection, he saw no need to give references, and no other book of the period treated the subject, as a result of which Düsing's contribution became lost to view. We here give the important paragraphs of Düsing's mathematical account, translated into English. 相似文献
13.
Summary The slow reassociating fraction of mouse DNA (unique DNA), when allowed to reassociate in 0.14 m sodium phosphate buffer at 50 °C showed a biphasic melting curve with a transition at 78–80 °C. On the basis of this feature, the slow reassociating DNA was separated preparatively into two fractions: unique DNA I and II. Their duplexes showed differences with respect to thermal stability, S1 nuclease resistance and rate of reassociation. About one third of the sequences in each fraction were fraction-specific. The conclusion was drawn that for unique DNA I these should be the low repetitive or single copy related sequences (multigene families) and for unique DNA II—the unrelated single copy sequences or recent families of low repetitive not yet diverged sequences. 相似文献
14.
Diesfeldt HF 《Tijdschrift voor gerontologie en geriatrie》2002,33(6):264-271
The goal of this study was to explore the correlation between education and the results of five dementia screening tests. In a study of 551 consecutively enrolled psychogeriatric day care attendants individual differences in education explained only very small portions of variance (< or = 0.63%) in four tests (visual recognition memory, orientation, category fluency and alternating sequences) of the Amsterdam Dementia Screening Test, a standard neuropsychological battery. The only exception was graphical copying of two- or three-dimensional geometric designs, where education explained 6.25% of the variance in copying accuracy. The more education participants had (from incomplete or complete primary education, through extended primary education, lower technical and vocational training, and secondary to higher education), the better their copying performance was. There was however one exception, in that participants with secondary education copied designs significantly less accurately than participants with lower technical and vocational training. Differences in copying accuracy of subjects with higher versus lower educational attainment were largest for participants matched for high levels of cognitive function. More severe cognitive impairment attenuated education effects. Higher education did not protect against decline of copying performance as a consequence of increasing cognitive impairment. For each of three educational levels, premorbid copying performance was estimated by constructing a regression equation using an independent measure of cognitive functioning (in terms of visual recognition memory, orientation and category fluency) as the predictor variable. The results support the clinical utility of controlling for educational level when interpreting individual copying performance. 相似文献
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It has been shown in a previous paper (8) that the prime product of reassociation of related DNA sequences under open experimental conditions are mismatched duplexes which undergo maturation upon further incubation. Due to this feature, the Tm value of the duplexes of a large number of DNAs is strongly dependent on the Cot value. Here we present data showing that the Tm of the duplexes of such type of DNAs depends also on the concentration of DNA in the range of one and the same Cot value. The significance of this finding in studying the taxonomic relationship by DNA-DNA hybridisation is discussed.Abbreviations Co =
initial concentration of single-stranded DNA in moles of nucleotides per liter
- t =
time of incubation in seconds
- Cot =
the product of Co and t (mol. sec. 11)
- PB =
an equimolar mixture of NaH2PO4 and Na2HPO4, pH 6.8
- HAP =
hydroxyapatite
- Ti =
incubation temperature
- Tm =
melting temperature
- Te =
elution temperature, i.e. the temperature at which one half of the DNA is eluted as single strands by HAP-thermal chromatography 相似文献
18.
W. C. Osman Hill 《Zoomorphology》1969,65(3):274-286
Musculature innervated by the N. facialis inTheropithecus gelada (Rüppell) is patterned on broad lines in agreement with related genera of catarrhine monkeys, but presents some specializations and divergences in detail. Noteworthy is the extension to the labial margins superficially of the combined levator labii superioris and zygomaticus in the upper and the pars mandibularis of trachelo-platysma in the lower lip. A specialization of the medial fibres of levator labii superioris forms a sling-like structure within the upper lip and serves to implement the lip-flip gesture characteristic of the genus. Its antagonist is the orbicularis oris. Special features of all other facialis muscles are considered.Abbreviations
ABD
Anterior belly of digastricus
-
AE
Arteria facialis
-
ALS
Arteria labialis superior
-
ANL
Arteria lateralis nasi
-
AP
Auricularis posterior
-
APA
Arteria auricularis posterior
-
AS
Arteria auricularis superior
-
A.Se.
Arteria septi nasi
-
A.Sy.
Arteria symphysialis
-
BP
Buccal pouch
-
LAO
Depressor anguli oris
-
FTA
Fronto-temporo-auricularis
-
GLI
Glandulae labialis inferiores
-
GLS
Glandulae labialis superioris
-
LAO
Levator anguli oris
-
LG
Artery to labial glands
-
LLAN
Levator labii superioris alaeque nasi
-
LLS
Levator labii superioris
-
M
Masseter
-
MM
Musculus mentalis
-
NP
Notoplatysma
-
O
Occipitalis
-
OO
Orbicularis oris
-
O.Oc
Orbicularis oculi
-
P
Procerus
-
SH
Sterno-hyoideus
-
TP
Trachelo-platysma
-
VL
Vena labialis communis
-
VP
Venous plexus of dorsum nasi
-
ZM
Zygomaticus minor
-
Zy
Zygomaticus 相似文献
19.
S. Keszthelyi 《Archives Of Phytopathology And Plant Protection》2013,46(13):1286-1294
The data originating from six different points of the Hungarian Light Trap Network (1960–2005) were processed for comprehensive examination of the European corn borer's (ECB) (Ostrinia nubilalis Hübner) flight dynamics. The annual flight diagrams were visually assayed. The annual alteration tendency of the quotients of the total trapped individual numbers (Σ), the relative individual number per day (1RIN) and the flight peak (FQ) were examined by means of linear regression analysis. The period and time of the alterations with comparative assay of five consecutive years series of data with Student's t-probe were revealed. Eventually I investigated the effects of annual average temperature on the examined flight parameters with the help of variance analysis. The change of ecology and flight dynamics of the ECB started in the first and extended to the second part of twentieth century is now continuing. This statement has been confirmed by the increasing number of trapped individuals (regression quotient calculated from Σ, etc.: Velence-Sukoró: 65.58; Tarhos: 131). This phenomenon can be best characterised by the appearance and spreading of the second late summer flight peak (average regression quotient calculated from FQ, etc.: 0.082). According to my experiment the gradually increasing temperature and climate play a part in the background of the national flight changes [significant connection between the annual average temperatures of Hungary and Σ (P = 0.021), - 1RIN (P = 0.043)]. The spreading of the bivoltine ecotype can be predicted from these results and the literary data of Hungary. 相似文献
20.
《Environmental Pollution (1970)》1979,18(1):31-43
Concentrations of zinc, cadmium, lead and iron were determined in whole soft parts of mussels, Mytilus edulis (L.), and in growing tips of the alga Fucus vesiculosus (L.) from a total of 20 locations in the area of the Sound between Sweden and Denmark. Pollution profiles produced for each metal were similar in any one of the species studied but the profiles for metals in M. edulis were distinct from those for metals in F. vesiculosus. Results for mussels agreed broadly with those reported previously for this region, indicating a northward decrease in available metal concentrations. By contrast, results for algae showed few differences in metal availability throughout the study area, although some local effects were evident.The differences in the pollution profiles exhibited by these two organisms depend on their response to different portions of the total trace metal load of ambient waters. Results from the alga agree well with available data on the concentrations of trace metals in solution in waters of the Sound. The alga thus appears to be responding only to metals in solution, as suggested by previous authors. By contrast, the major proportion of the total body load of metals in mussels is derived from ingested phytoplankton. The pollution profiles exhibited by mussels may be explained if phytoplankton from the Baltic Sea contain higher concentrations of trace metals than do those from Kattegat. Possible mechanisms for the production of such differences in the metal contents of the two phytoplankton populations, and the ecological implications of these differences, are briefly discussed. 相似文献