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1.
《Ibis》1943,85(1):41-43
T he purpose of this short treatise on the bills of Certhia familiaris Britannica Ridgway is to point out an as yet unrecognized sexual character in the species.  相似文献   

2.
Cognitive styles can be characterized as individual differences in the way people perceive, think, solve problems, learn, and relate to others. Field dependence/independence (FDI) is an important and widely studied dimension of cognitive styles. Although functional imaging studies have investigated the brain activation of FDI cognitive styles, the combined structural and functional correlates with individual differences in a large sample have never been investigated. In the present study, we investigated the neural correlates of individual differences in FDI cognitive styles by analyzing the correlations between Embedded Figures Test (EFT) score and structural neuroimaging data [regional gray matter volume (rGMV) was assessed using voxel-based morphometry (VBM)] / functional neuroimaging data [resting-brain functions were measured by amplitude of low-frequency fluctuation (ALFF)] throughout the whole brain. Results showed that the increased rGMV in the left inferior parietal lobule (IPL) was associated with the EFT score, which might be the structural basis of effective local processing. Additionally, a significant positive correlation between ALFF and EFT score was found in the fronto-parietal network, including the left inferior parietal lobule (IPL) and the medial prefrontal cortex (mPFC). We speculated that the left IPL might be associated with superior feature identification, and mPFC might be related to cognitive inhibition of global processing bias. These results suggested that the underlying neuroanatomical and functional bases were linked to the individual differences in FDI cognitive styles and emphasized the important contribution of superior local processing ability and cognitive inhibition to field-independent style.  相似文献   

3.
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5.
The situation is considered where the multivariate distribution of certain variables X1, X2, …, Xp is changing with time in a population because natural selection related to the X's is taking place. It is assumed that random samples taken from the population at times t1, t2, …, ts are available and it is desirable to estimate the fitness function wt(x1, x2,…,xp) which shows how the number of individuals with Xi = xi, i = 1, 2, …, p at time t is related to the number of individuals with the same X values at time zero. Tests for population changes are discussed and indices of the selection on the population dispersion and the population mean are proposed. The situation with a multivariate normal distribution is considered as a special case. A maximum likelihood method that can be applied with any form of population distribution is proposed for estimating wt. The methods discussed in the paper are illustrated with data on four dimensions of male Egyptian skulls covering a time span from about 4500 B.C. to about 300 A.D. In this case there seems to have been very little selection on the population dispersion but considerable selection on means.  相似文献   

6.

Background

In order to maintain cohesion of groups, social animals need to process social information efficiently. Visual individual recognition, which is distinguished from mere visual discrimination, has been studied in only few mammalian species. In addition, most previous studies used either a small number of subjects or a few various views as test stimuli. Dairy cattle, as a domestic species allow the testing of a good sample size and provide a large variety of test stimuli due to the morphological diversity of breeds. Hence cattle are a suitable model for studying individual visual recognition. This study demonstrates that cattle display visual individual recognition and shows the effect of both familiarity and coat diversity in discrimination.

Methodology/Principal Findings

We tested whether 8 Prim''Holstein heifers could recognize 2D-images of heads of one cow (face, profiles, ¾ views) from those of other cows. Experiments were based on a simultaneous discrimination paradigm through instrumental conditioning using food rewards. In Experiment 1, all images represented familiar cows (belonging to the same social group) from the Prim''Holstein breed. In Experiments 2, 3 and 4, images were from unfamiliar (unknown) individuals either from the same breed or other breeds. All heifers displayed individual recognition of familiar and unfamiliar individuals from their own breed. Subjects reached criterion sooner when recognizing a familiar individual than when recognizing an unfamiliar one (Exp 1: 3.1±0.7 vs. Exp 2: 5.2±1.2 sessions; Z = 1.99, N = 8, P = 0.046). In addition almost all subjects recognized unknown individuals from different breeds, however with greater difficulty.

Conclusions/Significance

Our results demonstrated that cattle have efficient individual recognition based on categorization capacities. Social familiarity improved their performance. The recognition of individuals with very different coat characteristics from the subjects was the most difficult task. These results call for studies exploring the mechanisms involved in face recognition allowing interspecies comparisons, including humans.  相似文献   

7.
Song sparrow (Melospiza melodia) songs are composed largely of pure-tonal sounds. This paper investigates the role that learning plays in the development of the tonal structure of song sparrow songs, as well as the role that tonal quality plays in determining the suitability of songs as models for learning. 20 birds were trained with both normal pure-tonal songs and modified songs that included harmonic overtones. The harmonic-modified songs were obtained from birds singing in a helium atmosphere, the result of which is to perturb vocal tract resonances and thus alter a song's tonal quality. Subjects learned equally well from normal and harmonic models. Birds that learned material from harmonic models reproduced some of this material with harmonic overtones, but the majority of notes learned from harmonic models were subsequently reproduced as pure-tonal copies. Thus, the tonal structure of songs does not influence young song sparrows in their selection of song models, but there is a strong tendency to reproduce songs in a pure-tonal fashion, even if learned from harmonic models.  相似文献   

8.
Song sparrow (Melospiza melodia) songs are composed largely of pure-tone notes. Song sparrows raised in acoustic isolation (i.e. never hearing conspecific songs) tend to produce half of their notes with harmonic overtones, an atypical tonal structure, suggesting that exposure to pure tones is necessary for the development of normal tonal quality. The experiment presented here directly investigated the influence of early exposure to songs with different tonal qualities on subsequent production. Seven young song sparrow males were exposed to 16 normal, pure-tone song sparrow songs and 6 males were exposed to the same 16 song types with added harmonic overtones. Birds in both groups learned equally well, confirming an earlier finding that tonal quality does not influence selection of models during the sensitive period for song acquisition. Birds exposed exclusively to harmonic song models, however, produced over 85% of their learned notes in a pure-tone fashion, even though they had never heard pure-tone sounds. Thus, pure tones do not need to be experienced directly by song sparrows, but exposure to some features of species-typical song models appears to facilitate the reproduction of models in a pure-tone fashion.  相似文献   

9.
Treatment of NADH with acid gives rise to as many as 10 products derived from breakdown of the dihydropyridine ring. These substances are neutral or cationic in character, and one or more may be carbonyls. They have been separated on a column of Dowex 1-formate and characterized spectrophotometrically. No evidence was obtained to indicate that acidification of NADH leads to formation of a dinucleotide containing a modified dihydronicotinamide moiety.  相似文献   

10.
The results in the antihuman lymphocytic globulines (AHLG) therapy of 25 patients with predominantly haematological and neurological diseases are reported. Extent and scope of the side-effects observed are discussed. A careful clinical, clinico-chemical and immunological observation of the patients during the AHLG therapy is indispensable for performing this biological immunosuppression and a strict selection of patients is also required. Under these conditions there are no higher risk and responsibility in an AHLG therapy than in other intensive kinds of therapy.  相似文献   

11.
Song-type matching during territorial contests may allow males of some bird species to direct their signal to a particular receiver. By matching the song-type and also responding immediately to a rival (temporal matching), a signalling male may indicate his willingness to escalate the contest. Black-capped chickadees ( Poecile atricapilla ) sing a single song-type, but are able to sing this song over a wide range of absolute frequencies. By using interactive playback to instigate and control the level of matching during trials, we investigated whether matching the frequency and the temporal patterning of song escalates contests. Males that were matched for both the frequency and the temporal pattern of their songs during trials escalated contests more than males that were not matched, while males that were only matched temporally had an intermediate response. During trials that consisted of temporal matching only, focal males often shifted frequency to match the playback. Our results confirm that frequency matching and temporal matching using a single song-type allows graded signalling during aggressive interactions in chickadees.  相似文献   

12.
Ten Gram-negative, rod-shaped and motile bacterial strains were isolated from spider crab (M27.10, M27.11a, F36.1, F36.4, M56.1, F76.17b, M146.1, M166.3 and M166.6) and pullet carpet shell clam (SBRF 1.10) collected in the coast of Galicia. Analyses of the 16S rRNA genes showed that the strains belong to the genus Kiloniella and have high similarity with the species Kiloniella spongiae (99.44–99.86%) and Kiloniella litopenaei (99.0–99.5%). Strains M56.1T (=CECT 9195, =LMG 29925), M146.1 (=CECT 9193, =LMG 29926) and SBRF 1.10 (=CECT 9194, =LMG 29927) were selected on the basis of genotyping by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Phylogenetic analysis based on concatenated sequences of the genes gyrB, ftsZ, rpoD and mreB showed that the isolates form a differentiated branch within the genus Kiloniella. Moreover, the average nucleotide identity (ANIm, ANIb and OrthoANI) and in silico estimated DNA–DNA reassociation values between selected Galician isolates and Kiloniella species were below the established cut-off for species deliniation. The results obtained in the genetic and phenotypical analyses indicate that the isolates represent a new species of the genus Kiloniella, for which the name Kiloniella majae sp. nov. is proposed with strain M56.1T (=CECT 9195T, =LMG 29925T) as the type strain.  相似文献   

13.
J T Lo  W L Mattice 《Biopolymers》1976,15(1):15-19
The positive circular dichroism band observed near 228 nm with poly(L -proline) responds in a similar fashion to HCl and CaCl2. The spectra in the HCl solutions are compatible with a simple binding equation and a pK near ?2 for the dissociation of a proton from a protonated peptide bond in poly(L -proline). The data obtained in CaCl2 is susceptible to the same analysis, suggesting a pK near ?1.5 for the dissociation of a calcium ion from its complex with poly(L -proline).  相似文献   

14.
β-Glucuronidase and sulfatase are the major deconjugating enzymes used in the cleavage of the glucuronate and sulfate moieties, respectively, from certain conjugated food factors including polyphenols. In the present study, we found that compounds having the same molecular weights as catechins were present in Helix pomatia- and/or Abalone entrails-derived β-glucuronidase and sulfatase by liquid chromatography tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring methods. On the other hand, the same molecular weights as catechins were undetectable in Escherichia coli-derived β-glucuronidase and Aerobacter aerogenes-derived sulfatase. By high performance liquid chromatography, enzyme-derived catechins were not detected because of approximately 1,000-fold lower sensitivity as compared to LC-MS/MS. These results suggest that the catechins in these enzymes might be attributed to the diets of the organisms as the enzyme sources.  相似文献   

15.
Extracts from the leaves of the Gingko tree (Ginkgo biloba L.) are therapeutically used for the treatment of peripheral and cerebral vascular disorders as well as multi-infarct or Alzheimer-type dementia. As constituents with potential contact allergenic and toxic properties in crude Ginkgo extracts a group of alkylphenols (e.g., ginkgolic acids, ginkgol, bilobol) has been described. Thus, for reasons of drug safety a maximal concentration (< or = 5 ppm) of ginkgolic acids is requested by the Monograph of the Commission E of the former German Federal Health Agency (Bundesgesundheitsamt, BGA). During production of the standardized Ginkgo extract EGb 761, alkylphenols are largely eliminated as water insoluble compounds (decanter sludge) from the primary acetone extract. To further assess the adverse properties of alkylphenols, different fractions derived from the decanter sludge were evaluated for their embryotoxic effects in the hen's egg test (HET). A fraction enriched for ginkgolic acids (16%) and biflavones (6.7%) was found to induce death of 50% of the chick embryos (LD50) at a dose of 1.8 mg/egg (approximately/= 33 ppm). A similar strong lethal effect (LD50: 3.5 mg/egg; 64 ppm) was oberserved for a fraction which contained 58% ginkgolic acids but less than 0.02% biflavones. In contrast, an extreme low toxic potential (LD50: 250 mg/egg or 4540 ppm) was established for a fraction containing 16% biflavones and 1% ginkgolic acids. Thus, the present investigations confirm the high toxic potential of ginkgolic acids, although it can not be excluded that biflavones or some other constituents in the different fractions may amplify the adverse effect of these substances. Since no contribution of alkylphenols to the therapeutic efficacy of Ginkgo extracts has been confirmed and their elimination during the manufacturing process does not cause technical problems, these results further support the requirement for the completest possible removal of these compounds under toxicological considerations.  相似文献   

16.
Although not a core symptom of the disorder, individuals with autism often exhibit selective impairments in their face processing abilities. Importantly, the reciprocal connection between autistic traits and face perception has rarely been examined within the typically developing population. In this study, university participants from the social sciences, physical sciences, and humanities completed a battery of measures that assessed face, object and emotion recognition abilities, general perceptual-cognitive style, and sub-clinical autistic traits (the Autism Quotient (AQ)). We employed separate hierarchical multiple regression analyses to evaluate which factors could predict face recognition scores and AQ scores. Gender, object recognition performance, and AQ scores predicted face recognition behaviour. Specifically, males, individuals with more autistic traits, and those with lower object recognition scores performed more poorly on the face recognition test. Conversely, university major, gender and face recognition performance reliably predicted AQ scores. Science majors, males, and individuals with poor face recognition skills showed more autistic-like traits. These results suggest that the broader autism phenotype is associated with lower face recognition abilities, even among typically developing individuals.  相似文献   

17.
Yeast isolates from soil samples collected from a latitudinal gradient (>77°S to >64°N) were subjected to multivariate analysis to produce a statistical foundation for observed relationships between habitat characteristics and the distribution of yeast taxa (at various systematic levels) in soil microbial communities. Combinations of temperature, rainfall (highly correlated with net primary productivity), and electrical conductivity (EC) could explain up to ca. 44% of the distribution of the predominant yeast species, rainfall and pH could explain ca. 32% of the distribution of clades in the most common orders (Filobasidiales and Tremellales), whereas vegetation type (trees, forbs, and grass) played the same role for orders. Cryptococcus species with appropriate maximum temperatures for growth predominated in most soils. Cryptococcus species in the Albidus clade of the Filobasidiales predominated in desert soils; Cryptococcus species of other clades in the Filobasidiales and Tremellales predominated in wetter and more-vegetated soils, with Tremellalean species favored in soils of lower pH or higher EC. The predominance of Cryptococcus species in soils has been attributed to their polysaccharide capsules, particularly important when competing with bacteria in arid soils.  相似文献   

18.
Cystobacter species strain CK 1 does not grow with more than 0.2 microgram/ml acriflavine. Spontaneous two-step mutants growing with 2 microgram acriflavine per ml have been selected. One mutant (strain CK3) was used to investigate the effect of repair inhibitors. Both strains exhibit pronounced shoulders in their UV dose curves of inactivation. Acriflavine (AF), coumarin (CU), and caffeine (CA) when incorporated in the post-irradiation plating medium decreased survival of irradiated cells. Post-treatment with 2 microgram acriflavine/ml abolished the shoulder of the curve. Caffeine (1600 microgram/ml) and coumarin (350 microgram/ml) reduced it only to about 40%. It is concluded that probably two repair mechanisms are present. Pre-treatment of the cells with 2 microgram acriflavine/ml for two hours before UV-irradiation resulted in a constant dose enhancement factor of 1.9. The protective effect is increased with the time of treatment with acriflavine. This may indicate that pyrimidine dimers are responsible for UV-inactivation.  相似文献   

19.
兔唇花属植物具有良好的止血活性,该属植物的化学成分研究也比较深入,但未见对冬青叶兔唇花化学成分的报道。为明确冬青叶兔唇花的化学成分,我们首次对其地上部分的非极性成分进行了GC-MS分析,并利用峰面积归一化法确定各成分的相对含量。从冬青叶兔唇花地上部分的非极性成分中,我们分离、鉴定了52种成分,占非极性成分总量的92.61%,主要包括脂肪酸酯、长链烷烃、单萜、倍半萜、甾体及芳香化合物等。本研究为兔唇花属植物资源的合理开发利用奠定了基础。  相似文献   

20.

Background

Systemic sclerosis (SSc) is an autoimmune disease characterized by immunological and vascular abnormalities. Until now, the cause of SSc remains unclear. Sclerodermatous graft-versus-host disease (ScGVHD) is one of the most severe complications following bone marrow transplantation (BMT) for haematological disorders. Since the first cases, the similarity of ScGVHD to SSc has been reported. However, both diseases could have different etiopathogeneses. The objective of this study was to identify new serum biomarkers involved in SSc and ScGVHD.

Methodology

Serum was obtained from patients with SSc and ScGVHD, patients without ScGVHD who received BMT for haematological disorders and healthy controls. Bi-dimensional electrophoresis (2D) was carried out to generate maps of serum proteins from patients and controls. The 2D maps underwent image analysis and differently expressed proteins were identified. Immuno-blot analysis and ELISA assay were used to validate the proteomic data. Hemolytic assay with sheep erythrocytes was performed to evaluate the capacity of Factor H (FH) to control complement activation on the cellular surface. FH binding to endothelial cells (ECs) was also analysed in order to assess possible dysfunctions of this protein.

Principal Findings

Fourteen differentially expressed proteins were identified. We detected pneumococcal antibody cross-reacting with double stranded DNA in serum of all bone marrow transplanted patients with ScGVHD. We documented higher levels of FH in serum of SSc and ScGVHD patients compared healthy controls and increased sheep erythrocytes lysis after incubation with serum of diffuse SSc patients. In addition, we observed that FH binding to ECs was reduced when we used serum from these patients.

Conclusions

The comparative proteomic analysis of serum from SSc and ScGVHD patients highlighted proteins involved in either promoting or maintaining an inflammatory state. We also found a defective function of Factor H, possibly associated with ECs damage.  相似文献   

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