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151.
E. Frankel 《Biometrical journal. Biometrische Zeitschrift》1984,26(7):741-748
In the present paper we present an example proving that the Varimax rotation method commonly used in factor analysis (see H. F. KAISER, 1958) need not give a unique solution. We also show that changing the original algorithm more than one local maximum of the criterion “V” can be achieved. Hence the loadings of factors and practical interpretations of solutions are affected in this way. 相似文献
152.
Growth hormone-releasing factor (GRF) is a hypothalamic peptide named for its ability to induce release of growth hormone from the anterior pituitary. GRF also acts as a neurotransmitter in the suprachiasmatic nucleus/medial preoptic area (SCN/MPOA) to stimulate food intake. The purpose of this series of experiments was to explore the nature of GRF-induced feeding, with a particular emphasis on macronutrient selectivity, and to examine the role of opiate activity in the paraventricular nucleus of the hypothalamus (PVN). Chow intake stimulated by GRF microinjection (1 pmol/0.5 μl) into the SCN/MPOA was blocked by injection of methyl-naltrexone (3 μg/0.5 μl) into the PVN. In animals habituated to macronutrient diets (Teklad, WI), GRF preferentially stimulated intake of protein at 2 and 4 h postinjection, whereas it had no effect on carbohydrate intake. Further, this effect was blocked by injection of naloxone (40 nmol/0.5 μl) into the PVN. Microinjection of morphine (0, 1, 10, and 17 μg/0.5 μl) into the PVN also specifically stimulated protein intake at 2 and 4 h postinjection. These results suggest that feeding derived from GRF actions in the SCN/MPOA is macronutrient selective, and is dependent on PVN opiate activity for expression. 相似文献
153.
Six polymorphic dinucleotide microsatellite loci were isolated and characterized from the White‐chinned Petrel Procellaria aequinoctialis, using a degenerate primer and PCR‐based technique to construct and screen an enriched genomic library. Preliminary data on three populations show heterozygosity levels ranging from 0.22 to 0.67 and allele numbers from three to nine. Preliminary data also suggest genetic distance between these three populations (FST 0.088). Cross‐species amplification of these six microsatellite loci and one further locus were tested in six other procellariiform species of the genus Procellaria, Macronectes, Thalassarche and Diomedea. 相似文献
154.
The analysis of genetic variation to estimate demographic and historical parameters and to quantitatively compare alternative scenarios recently gained a powerful and flexible approach: the Approximate Bayesian Computation (ABC). The likelihood functions does not need to be theoretically specified, but posterior distributions can be approximated by simulation even assuming very complex population models including both natural and human‐induced processes. Prior information can be easily incorporated and the quality of the results can be analysed with rather limited additional effort. ABC is not a statistical analysis per se, but rather a statistical framework and any specific application is a sort of hybrid between a simulation and a data‐analysis study. Complete software packages performing the necessary steps under a set of models and for specific genetic markers are already available, but the flexibility of the method is better exploited combining different programs. Many questions relevant in ecology can be addressed using ABC, but adequate amount of time should be dedicated to decide among alternative options and to evaluate the results. In this paper we will describe and critically comment on the different steps of an ABC analysis, analyse some of the published applications of ABC and provide user guidelines. 相似文献
155.
Summary In the pars tuberalis of the hypophysis of Rana temporaria, which shows the ultrastructural characteristics of a polypeptide hormone secreting endocrine gland, seasonal changes of the ultrastructure are described. In accordance with the literature, these seasonal changes of ultrastructure are interpreted as the morphological expression of seasonal changes of endocrine activity of the pars tuberalis. 相似文献
156.
Piotr Politański Elźbieta Rajkowska Marcin Brodecki Andrzej Bednarek Marek Zmyślony 《Bioelectromagnetics》2013,34(4):333-336
The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
157.
Soil and climate are major constituents of the French notion of Terroir. This concept implies that there is a strong relationship
between the composition of the grape, the characteristics of the wine and the territory of production. To study this link,
a new method of characterization of the Terroir, including geological and pedological factors, was investigated. It uses a
field model based on depth and clay content of soil, together with the degree of weathering of the parent rock. Consequently,
for every type of parent rock belonging to a given geologic stage, there are a series of soils that show different stages
of pedological evolution. According to the model, three kinds of soils are distinguished with regards to the weathering intensity
of the parent rock, that are named weakly weathered rock (WWR), moderately weathered rock (MWR) and strongly weathered rock
(SWR). By hypothesis, each soil type is considered as a homogeneous unit for vine production from the viewpoint of ecophysiological
factors. Each terroir unit defined by this method is called a Basic Terroir Unit (BTU). To validate this hypothesis, experimental
plots planted with Chenin and Cabernet Franc vines were studied over three consecutive seasons (2000–2002), in the Anjou vineyard
(Loire Valley – France). The major BTUs developed on the two most important geological systems of Anjou (Brioverian and Ordovician–Devonian),
were studied. Results showed that the berries of vines cultivated in WWR were significantly smaller, richer in sugars and
anthocyanins and had a Total Phenolic Index higher than those of the vines cultivated in SWR. They also had a lower titratable
acidity. Cabernet Franc vines cultivated in MWR had berries with sugar and anthocyanin contents but also total phenolics very
close to those of WWR. With Chenin vines there was a good relationship between the global pool of free aromas of berries and
the BTU type. The study showed significant relationships between the quality of grapes and the measured values of several
ecophysiological variables such as the water supply regime or the timing of budburst. 相似文献
158.
Prashanth Sirigeri Jois 《Biochemical and biophysical research communications》2010,394(4):1036-1041
Bovine BSP5 belongs to the Binder of SPerm (BSP) family. BSP5 plays a role in the bovine sperm capacitation by promoting cholesterol and phospholipid efflux. The variable N-terminal part in the BSP proteins is the uncharacterized region with no known function. Full-length, N-terminal part, and individual fibronectin type II domains of bovine BSP5 were cloned, expressed and purified from Escherichia coli. His-S tagged N-terminal part showed large variation in migration on SDS-PAGE in comparison to other constructs. Using mass spectrometry it was demonstrated that the His-S-N-terminal part has the expected molecular mass (13 kDa). The recombinant N-terminal part was sensitive to E. coli endogenous proteases during purification. Denaturing purification involving boiling lysis of cells was carried out, as the protein was thermostable. The His-S-N-terminal part lacked structure as determined by CD analysis. Bioinformatics analyses confirmed that the N-terminal part of bovine BSP5 is intrinsically disordered. In addition, bioinformatics analysis indicated that rabbit BSP and multiple forms of BSP proteins of bovine and equine species possess partially or completely disordered N-terminus. The conservation of disorder at the N-terminus in BSP members belonging to different species suggests a role in biological process such as sperm capacitation and/or sperm-egg interactions. 相似文献
159.
In Callithrix jacchus the urinary excretion of hydroxypregnanolone (5 alpha-pregnane-3 alpha, 7 alpha-diol-20-one) shows a luteal rise during the ovulatory cycle. This progesterone metabolite can therefore be used as an indication of ovulation, implantation, and subsequently for the persistence of the pregnancy. The excretion can be monitored by high performance thin-layer chromatography (HPTLC) and postchromatographic derivatization after enzymatic hydrolysis of the conjugate. Profiles of urinary hydroxypregnanolone levels are presented and correlated with luteinizing hormone excretion. The method is noninvasive and therefore suited for long-term studies in these monkeys. 相似文献
160.
The current examination was intended to observe the defensive impacts of embelin against paraquat‐incited lung damage in relationship with its antioxidant and anti‐inflammatory action. Oxidative stress marker, like malondialdehyde (MDA), antioxidative enzymes, for example, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH Px), inflammatory cytokines, such as interleukin‐1β (IL‐1β), tumor necrosis factor‐α, and IL‐6, histological examination, and nuclear factor kappa B/mitogen‐activated protein kinase (NF‐κB/MAPK) gene expression were evaluated in lung tissue. Embelin treatment significantly decreased MDA and increased SOD, CAT, and GSH Px. Embelin significantly reduced levels of inflammatory cytokines in paraquat‐administered and paraquat‐intoxicated rats. In addition, embelin suggestively decreased relative protein expression of nuclear NF‐κB p65, p‐NF‐κBp65, p38 MAPK, and p‐p38 MAPKs in paraquat‐intoxicated rats. The outcomes show the impact of embelin inhibitory action on NF‐κB and MAPK and inflammatory cytokines release, and the decrease of lung tissue damage caused by paraquat. 相似文献