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1.
Five traits of early child development were studied in 656 infants from the day of birth till 2 years of age. The infants
selected for follow-up were born at 26–42 weeks of gestational age and with a birth weight accordingly ranging from 860 to
4560g. Analysis of variance was carried out for each of the following five traits which entailed the age at which a child:
1) turned himself over (turned); 2) sat unsupported for a few seconds (sat); 3) stood up (stood); 4) walked unsupported (walked);
and 5) cut its first tooth (tooth). The results of this survey show no significant sex differences in the age of initial occurrence
of any of the studied traits. Comparison with older siblings of the surveyed infants indicated a significant sibling resemblance
component for all 5 trais, with the respective intraclass correlation coefficients ranging between 0.34 and 0.53. Gestational
age and birth weight, but not “tooth”, appeared to be important messages of an infant's motor development, insofar as onset
of the studied traits. The separate correlations of “turned”, “sat”, “stood” and “walked” with gestational age or weight were
all negative and statistically highly significant.
Research Unit — Human Population Biology, Division of Anatomy and Anthropology 相似文献
2.
Hilary O. Box 《Primates; journal of primatology》1977,18(2):395-400
Four male and four female marmoset monkeys were observed to make a total of 5,600 “right”, “left”, or “both” hand responses
over seven categories of spontaneous behaviour. Significant and consistent hand preferences were shown for the majority of
monkeys in two of the categories of behaviour, but not in the other five. The paper considers some of the methodological difficulties
involved in recording “handedness” in a species such as the common marmoset. 相似文献
3.
Alison Woodcock 《Primates; journal of primatology》1983,24(4):501-514
In a series of five experiments, female/female twin and male/male twin common marmosets were observed in each of the following
social situations: as offspring in their respective family groups; housed together as twins; in competition for a mate and
in the heterosexual pairs resulting from this competition. Quantitative records were made of their behaviour. These were then
related to winning or losing the competition for a mate. Individuals who demonstrated more “assertive” behaviour and won the
competition (winners) were not in every experiment faster to produce and rear offspring than were the less “assertive” animals
(losers). Categories of behaviour described as “assertive” predicted the outcome of the competition in most cases, but were
not good indicators of future breeding potential. 相似文献
4.
5.
Fruit ethylene production genotypes for Md-ACS1 and Md-ACO1 were determined for 60 apple cultivars and 35 advanced breeding
selections. Two alleles for each gene are commonly found in cultivated apple. Earlier studies showed that genotypes homozygous
for the ACS1-2 allele produce less ethylene and have firmer fruit than ACS1-1/2 and ACS1-1/1 genotypes. ACO1 plays a minor
role compared to ACS1, with homozygous ACO1-1 having lower ethylene production. In this study, ACS1-2 and ACO1-1 homozygotes
had firmer fruit at harvest and after 60 days of 0–1°C cold storage compared to other genotypes. These genotypes, ACS1-2/2
and ACO1-1/1, were observed for the following 8 of 95 cultivars/selections: “Delblush”, “Fuji”, “Pacific Beauty”, “Sabina”
and four breeding selections. Cultivars/selections that were homozygous ACS1-2 but not ACO1-1 were: “Ambrosia”, “Aurora Golden
Gala”, “CrimsonCrisp”, “Gala”, “GoldRush”, “Huaguan”, “Pacific Rose, “Pacific Queen”, “Pinova”, “Sansa”, “Sonja”, “Sundance”,
“Zestar”, and 17 breeding selections. Cultivars with the heterozygous ACS1-1/2 genotype were “Arlet”, “Braeburn”, “Cameo”,
“Delicious”, “Delorgue”, “Empire”, “Enterprise”, “Ginger Gold”, “Golden Delicious”, “Granny Smith”, “Honeycrisp”, “Orin”,
“Pink Lady”, “Silken”, “Suncrisp”, “Sundowner”, “Sunrise” and 11 breeding selections. No cultivars were detected homozygous
for both ACS1-1 and ACO1-1, or for both ACS1-2 and ACO1-2. This study is the first large-scale allelic genotyping of both
ethylene synthesis genes for a comprehensive set of apple breeding parents used in an ongoing breeding project. The data reported
here are important for informative selection of parent combinations and marker-assisted selection of progeny for breeding
low ethylene-producing apple cultivars for better storability and improved consumer acceptance. 相似文献
6.
Kenji Konishi Tsutomu Tamura Ryoko Zenitani Takeharu Bando Hidehiro Kato Lars Walløe 《Polar Biology》2008,31(12):1509-1520
The annual trend in energy storage in the Antarctic minke whale was examined using catch data from all 18 survey years in
the Japanese Whale Research Program (JARPA). Regression analyses clearly showed that blubber thickness, girth and fat weight
have been decreasing for nearly 2 decades. The decrease per year is estimated at approximately 0.02 cm for mid-lateral blubber
thickness and 17 kg for fat weight, corresponding to 9% for both measurements over the 18-year period. Furthermore, “date”,
“extent of diatom adhesion”, “sex”, “body length”, “fetus length”, “latitude”, “age” and “longitude” were all identified as
partially independent predictors of blubber thickness. The direct interpretation of this substantial decline in energy storage
in terms of food availability is difficult, since no long-term krill abundance series is available. However, an increase in
the abundance of krill feeders other than minke whales and a resulting decrease in the krill population must be considered
as a likely explanation. 相似文献
7.
Anatol Rapoport 《Bulletin of mathematical biology》1947,9(3):109-122
Motivations of two individuals governed by a satisfaction function are assumed to determine their respective “efforts”, which
result in the production of “output”, i.e., objects of satisfaction. In previous papers the sharing of output was prescribed
in advance. In the present article, however, the sharing formula itself is determined to a certain extent by the satisfaction
function. The rate of remuneration per unit of output for each individual is taken to be proportional to the derivative of
the satisfaction of the other individual with respect to the effort of the first. The formulation of this condition leads
to a partial differential equation whose solutions determine the sharing formula. Sharing determined in this way is referred
to as sharing according to the Condition of Mutual Need (C.M.N.). Satisfaction resulting from five different situations are
the computed and compared: (1) an individual producing and consuming alone; (2) two individuals sharing equally and neither
taking the “initiative” to determine the optimum output; (3) sharing determined by C.M.N. with optimum output determined as
in (2); (4) equal sharing but with one individual taking “initiative” in determining optimal output; and (5) sharing determined
by C.M.N. and optiml output by the “initiative” of one individual. further considerations concern conditions imposed on the
arbitrary function occurring in the solution of the above-mentioned partial differential equation. 相似文献
8.
The intentional introduction of exotic species can increase the level of local biodiversity, enrich people’s material lives,
and bring significant social and economic benefits that are also the symbols of human progress. However, along with the frequent
intercourse among countries and regions, the frequency of uncontrolled crossregional migration of species is increased and
there is a lack of scientific management strategy for the intentional introduction of exotic species. Exotic species invasion,
which is behind habitat fragmentation, has become the second largest threatening factor to the maintenance of the global-scale
level of biological diversity. Exotic species invasion can destroy the structure of an ecosystem, disturb the economic life
of a society, and do harm to human health. In this paper, the authors review some of the ecological explanations for issues
such as “what causes or mechanisms have led to the successful invasion of exotic species”, including the “ideal weeds characteristics”,
“biodiversity resistance hypothesis”, “enemies release hypothesis”, “evolution of increased competitive ability hypothesis”,
“niche opportunity hypothesis”, and “novel weapon hypothesis”. The authors also analyze and evaluate the background and theoretical
basis of the hypotheses, providing explanations for some phenomena, as well as the deficiencies of these explanations. 相似文献
9.
Nutan Karnik H. Channaveerappa H. A. Ranganath Raghavendra Gadagkar 《Journal of genetics》2010,89(2):173-182
The queenless ponerine ant Diacamma ceylonense and a population of Diacamma from the Nilgiri hills which we refer to as ‘nilgiri’, exhibit interesting similarities as well as dissimilarities. Molecular phylogenetic study of these morphologically almost
similar taxa has shown that D. ceylonense is closely related to ‘nilgiri’ and indicates that ‘nilgiri’ is a recent diversion in the Diacamma phylogenetic tree. However, there is a striking behavioural difference in the way reproductive monopoly is maintained by
the respective gamergates (mated egg laying workers), and there is evidence that they are genetically differentiated, suggesting
a lack of gene flow. To develop a better understanding of the mechanism involved in speciation of Diacamma, we have analysed karyotypes of D. ceylonense and ‘nilgiri’. In both, we found surprising inter-individual and intra-individual karyotypic mosaicism. The observed numerical variability,
both at intra-individual and inter-individual levels, does not appear to have hampered the sustainability of the chromosomal
diversity in each population under study. Since the related D. indicum displays no such intra-individual or inter-individual variability whatsoever under identical experimental conditions, these
results are unlikely to be artifacts. Although no known mechanisms can account for the observed karyotypic variability of
this nature, we believe that the present findings on the ants under study would provide opportunities for exciting new discoveries
concerning the origin, maintenance and significance of intra-individual and inter-individual karyotypic mosaicism. 相似文献
10.
Massen JJ Overduin-de Vries AM de Vos-Rouweler AJ Spruijt BM Doxiadis GG Sterck EH 《International journal of primatology》2012,33(1):73-92
Male mating success in a multimale–multifemale group can depend on several variables: body condition, dominance, coalitions,
“friendship,” or an exchange of services for mating access. Exchange patterns may also be determined by market effects or
social relationships. We studied the mating tactics of males in a captive, multimale–multifemale group of rhesus macaques
and the resulting patterns of mating and paternity to determine the influence of dominance rank, mating markets, and relationship
quality on their mating tactics. Male rank was positively related to the total number of copulations and the number of mating
partners, but did not explain male mating distribution completely. Moreover, male fertilization success was not related to
male rank. Males did not exchange grooming for mating access on the same day and neither the supply nor the rank (as a proxy
for quality) of receptive females affected the amount of male grooming, suggesting that market effects did not explain male
mating access. However, there was a positive correlation between long-term grooming patterns of both males and females and
mating access, indicating that social relationships were important for male mating access. Paternity data revealed that these
social relationships were also important for male reproductive success. We conclude that both male rank and male–female “friendship”
determined male mating access in these rhesus macaques, but that “friendship” was more important in determining paternity,
emphasizing the importance of intersex social bonds in male mating success in multimale primate societies. 相似文献
11.
Pedersen PL 《Journal of bioenergetics and biomembranes》2007,39(3):211-222
As a new faculty member at The Johns Hopkins University, School of Medicine, the author began research on cancer in 1969 because
this frequently fatal disease touched many whom he knew. He was intrigued with its viscous nature, the failure of all who
studied it to find a cure, and also fascinated by the pioneering work of Otto Warburg, a biochemical legend and Nobel laureate.
Warburg who died 1 year later in 1970 had shown in the 1920s that the most striking biochemical phenotype of cancers is their
aberrant energy metabolism. Unlike normal tissues that derive most of their energy (ATP) by metabolizing the sugar glucose
to carbon dioxide and water, a process that involves oxygen-dependent organelles called “mitochondria”, Warburg showed that
cancers frequently rely less on mitochondria and obtain as much as 50% of their ATP by metabolizing glucose directly to lactic
acid, even in the presence of oxygen. This frequent phenotype of cancers became known as the “Warburg effect”, and the author
of this review strongly believed its understanding would facilitate the discovery of a cure. Following in the final footsteps
of Warburg and caught in the midst of an unpleasant anti-Warburg, anti-metabolic era, the author and his students/collaborators
began quietly to identify the key molecular events involved in the “Warburg effect”. Here, the author describes via a series
of sequential discoveries touching five decades how despite some impairment in the respiratory capacity of malignant tumors,
that hexokinase 2 (HK-2), its mitochondrial receptor (VDAC), and the gene that encodes HK-2 (HK-2 gene) play the most pivotal
and direct roles in the “Warburg effect”. They discovered also that like a “Trojan horse” the simple lactic acid analog 3-bromopyruvate
selectively enters the cells of cancerous animal tumors that exhibit the “Warburg effect” and quickly dissipates their energy
(ATP) production factories (i.e., glycolysis and mitochondria) resulting in tumor destruction without harm to the animals. 相似文献
12.
The objective of this article is to study the effect of 5-aminolevulinic acid (ALA) and enhanced chlorophyll content, antioxidative
enzymes and photosynthesis rate by foliar application of ALA. We evaluated three concentrations (control-distilled water,
T1-50 mg l−1, T2-150 mg l−1, T3-250 mg l−1) of ALA and seven cultivars, “Sanchidaye” (Sa-1), “Lichuandasuomian” (Li-1), “Aijiaohuang” (Ai-1), “Qingyou” No. 4 (Qi-1),
“Aikang” No. 5 (Ak-1), “Hanxiao” (Ha-1) and “Shulv” (Sl-1). “Ak-1” showed strongest response of POD (peroxidase) enzyme activity
(0.4 U g−1 min−1) in 250 mg l−1 ALA solution. The highest CAT (catalase) activity (0.8 U g−1 min−1) after administration of 250 mg l−1 ALA was observed in “Li-1”. Meanwhile, highest (1.42 mg l−1) total chlorophyll content was also observed in “Ak-1”, when leaves were treated in 50 mg l−1 ALA, “Li-1” and “Ai-1” showed strongest response of specific activity of superoxide dismutase (SOD) in 50 mg l−1 and 50 mg l−1 ALA. Two hundred and fifty milligram per milliliter of ALA-treatment significantly improved the net photosynthetic rate. 相似文献
13.
Yan Xu Haihui Ye Jun Ma Huiyang Huang Guizhong Wang 《In vitro cellular & developmental biology. Animal》2010,46(8):708-717
Crustacean neurons, obtained from the cerebral ganglion of the mud crab Scylla paramamosain, were successfully cultured in vitro. They maintained typical morphological characteristics and showed better outgrowth in
modified Medium 199 (M199) medium than that in Liebowitz’s L-15 medium. Fetal bovine serum (FBS), muscle extracts, and hemolymph
of the mud crab S. paramamosain were added as supplements. Only 20% FBS could promote neuron outgrowth, while muscle extracts and hemolymph of S. paramamosain did not improve neuron outgrowth. For cell dissociation, both collagenase type I and trypsin worked well as determined by
initial cell viability and following cell outgrowth potential. More than six kinds of cells with different morphological characteristics
were identified in the neuron outgrowth. They were “small cells”, “veilers”, “branchers”, “multipolar cells”, “super-large
cell”, and “bipolar cells”. Among all of the cells, bipolar cells were identified for the first time in crustacean neurons
culture and they could live longer than other cells. The neurons could grow for more than a week before retraction and eventual
degradation. 相似文献
14.
Health status of trees was studied in five types of native spruce forests in the Pechora-Ilych Nature Biosphere Reserve. The
study has shown that trees in the old-growth bilberry-spruce and fern-shamrock-spruce forests can be characterized as “healthy”,
with damage index varying from 0.03 to 0.5. The haircap-moss spruce forest with damage index 0.7 is categorized as a “weakened
stand”. Regeneration was pronounced in all forest types. Young growth (1500 to 4300 stems/ha) is mainly composed of conifers
and is classified as “healthy”. 相似文献
15.
François Mankessi Aubin R. Saya Frédéric Boudon Yann Guédon Fabienne Montes Marc Lartaud Jean-Luc Verdeil Olivier Monteuuis 《Trees - Structure and Function》2010,24(4):743-752
Shoot apical meristem (SAM) domes derived from five different outdoor and in vitro sources of juvenile and mature Eucalyptus urophylla × Eucalyptus grandis akin genotypes were compared. Overall measurements of SAM dome height H and diameter D ranged from 2 to 35 μm and 20 to 80 μm, with significant differences according to the various physiological origins of plant
material investigated. SAM domes from the mature trees “Mat” were taller than those from the rejuvenated ministock plants
“Rej”; from the in vitro microcuttings “IVM” of the same clone and also from the in vitro juvenile seedlings “IVJ”, whereas
outdoor seedlings “Juv” exhibited intermediate SAM dome height. SAM domes from the rejuvenated material “Rej”, from the in
vitro mature “IVM” and juvenile “IVJ” origins were also narrower than those from the outdoor seedlings “Juv” and to lesser
extent than those from the mature trees “Mat”. Overall, the mature source “Mat” displayed bigger and somehow sharper hemispherical
domes than those from “Rej” and “Juv”, physiologically more juvenile, or those from the in vitro origins “IVM” and “IVJ” which
looked flatter and smaller. SAM dome height, diameter D and H/D values varied also significantly according to the plastochron. More specifically, H, D, and H/D SAM differences between the five origins were not significant during the early plastochron phase corresponding to leaf initiation,
to become more salient as leaf structures started to elongate and to differentiate. This was particularly obvious for mature
tree “Mat” SAM dome shapes which showed at this stage much higher H/D values than the other SAM sources. A shape index S used for characterizing more accurately dome shape confirmed these trends. These observations provide additional arguments
to the view that juvenility in trees becomes more and more time- and shoot-tip restricted as ageing increases in the course
of time during the ontogenetical process and could be ultimately confined to the most organogenic phase of SAM, from which
shoot characteristics derive. 相似文献
16.
Previously, it was clarified that phycobilisome (PBS) mobility and energy spillover were both involved in light-to-dark induced
state transitions of intact Spirulina platensis cells. In this work, by taking advantage of the characteristic fluorescence spectra of photosystem I (PSI) trimers and monomers
as indicators, the relative contributions for the “mobile PBS” and “energy spillover” are quantitatively estimated by separating
the fluorescence contribution of PBS mobility from that of PSI oligomeric change. Above the phase transition temperature (T
PT) of the membrane lipids, the relative proportion of the contributions is invariable with 65% of “mobile PBS” and 35% of “energy
spillover”. Below T
PT, the proportion for the “mobile PBS” becomes larger under lowering temperature even reaching 95% with 5% “energy spillover”
at 0°C. It is known that lower temperature leads to a further light state due to a more reduced or oxidized PQ pool. Based
on the current result, it can be deduced that disequilibrium of the redox state of the PQ pool will trigger PBS movement instead
of change in the PSI oligomeric state. 相似文献
17.
Parasites often confront conflicting demands when evaluating and distributing themselves among host individuals, in order to attain maximum reproductive success. We tested two alternative hypotheses about host preference by fleas in relation to the age of their rodent host. The first hypothesis suggests that fleas select adult over juvenile rodents because the latter represent a better nutritional resource (the “well-fed host” hypothesis), whereas the second hypothesis suggests that fleas prefer the weaker and less resistant juveniles because they are easier to colonise and exploit (“poorly fed host” hypothesis). We sampled fleas (Synosternus cleopatrae) on the gerbil (Gerbillus andersoni) in 23 different plots in the Negev desert and found an unequal distribution of fleas between adult and juvenile hosts. Furthermore, flea distribution changed as a function of flea density—from juvenile-biased flea parasitism (the “poorly fed host” hypothesis) at low densities to adult-biased flea parasitism (the “well-fed host” hypothesis) at high densities. Other factors that influenced flea preference were soil temperature and the presence of ticks. These results suggest that host selection is not an explicit alternative choice between adults and juveniles (“well-fed host” versus “poorly fed host” hypotheses), but rather a continuum where the distribution between adults and juveniles depends on host, parasite, and environmentally related factors. 相似文献
18.
Norio Murata 《Photosynthesis research》2009,99(3):155-160
In the late 1960s, I identified an aspect of the kinetics of chlorophyll fluorescence in algal cells that I was unable to
explain in terms of photochemical quenching. I proposed a novel regulatory mechanism for the distribution of light energy
to photosystems I and II, which is now known by the term of “state transitions.” I also examined the “cation-dependent redistribution
of light energy” to photosystems I and II and the “energy-dependent quenching” of chlorophyll fluorescence. At that time,
financial constraints prevented me from measuring the emission and action spectra of chlorophyll fluorescence at liquid-nitrogen
temperature and the light quality-dependent changes in the yield of chlorophyll fluorescence at room temperature. The financial
problems were solved by constructing several pieces of electronic equipment using skills obtained by repairing radios when
I was a high-school and college student. 相似文献
19.
20.
Date palm (Phoenix dactylifera L.) is one of the most important domesticated fruit trees in the Near East and North African countries. This tree has been,
for several decades, in serious threat of being completely destroyed by the “Bayoud” disease caused by Fusarium oxysporum f. sp. albedinis. In this study, 18 Syrian date palm cultivars and four male trees were analyzed according to the identity of mitochondrial
plasmid-like DNAs. A PCR strategy that employs plasmid-like DNAs-specific primer pair was used. These primers amplify a product
of either 373-bp or 265-bp that corresponds to the S- (Bayoud-susceptible) or the R-plasmid (Bayoud-resistant), respectively. Generated data revealed that only six cultivars (“Medjool”, “Ashrasi”, “Gish Rabi”,
“Khineze”, and yellow- and red-“Kabkab”) have the S-plasmid, suggesting their susceptibility to the fusariosis, while the remaining 12 cultivars and the four male trees contain
the R-plasmid, suggesting their resistance to the fusariosis. The PCR process applied here has been proved efficient for the rapid
screening for the presence of the S and R DNAs in Syrian date palm. PCR markers developed in this study could be useful for the screening of date palm lines growing
in the field. The availability of such diagnostic tool for plasmid characterization in date palm would also be of great importance
in establishing propagation and breeding programs of date palm in Syria. 相似文献