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1.
A living hen is a very attractive imprinting stimulus compared to artificial stimuli. The present study examined to what extent this attractiveness is influenced by the behaviour of the hen. The effectiveness of a living quail hen as an imprinting stimulus was compared with that of a moving stuffed hen, a non-moving stuffed hen and an empty cage. Naive quail chicks were exposed to one of these stimuli for 2 h. Both during and after this period chicks exposed to the living hen showed the strongest attachment to the stimulus, next came chicks exposed to a moving stuffed hen, while chicks exposed to a non-moving stuffed hen showed no indication of any attachment, i.e. they behaved in the same way as chicks exposed to an empty cage. Also, among chicks exposed to the living hen a correlation was present between the strength of the attachment to the hen and the behaviour of this hen during the exposure. In particular pecking and behaviour directed at the chick seemed to stimulate the development of a filial bond. Together, these findings indicate that a living hen is attractive not just because she moved, but also because of specific qualities of this movement. The behaviour of the living hen differed in various ways from the movement of the moving stuffed hen. The influence of these differences on the filial imprinting process is discussed and compared with similar findings for sexual imprinting and song learning.  相似文献   

2.
The findings obtained in neurophysiological and psychophysical investigations using tactile stimuli that move at constant velocity across the skin are reviewed. For certain neurons in the postcentral gyrus of the cerebral cortex (S-I) of macaque monkeys, direction of stimulus motion is a "trigger feature" i.e., moving tactile stimuli evoke vigorous discharge activity in these neurons only if the stimuli are moved in a particular direction across the receptive field. This directional selectivity is maximal when stimulus velocity is between 5 and 50 cm/sec, and falls off rapidly at lower or higher velocities. The capacity for human subjects to correctly identify the direction of stimulus motion on the skin exhibits a similar dependence on stimulus velocity. The similar effects of velocity on neural and psychophysical measures of directional sensitivity support the idea that direction of stimulus motion on the skin can only be recognized if the moving stimulus optimally activates the group of S-I neurons for which that directions of simulus motion is the trigger feature.  相似文献   

3.
The extent to which an animal is affected by the pain or distress of a conspecific will depend on its capacity for empathy. Empathy most probably evolved to facilitate parental care, so the current study assessed whether birds responded to an aversive stimulus directed at their chicks. Domestic hens were exposed to two replicates of the following conditions in a counterbalanced order: control (C; hen and chicks undisturbed), air puff to chicks (APC; air puff directed at chicks at 30 s intervals), air puff to hen (APH; air puff directed at hen at 30 s intervals) and control with noise (CN; noise of air puff at 30 s intervals). During each test, the hens' behaviour and physiology were measured throughout a 10 min pre-treatment and a 10 min treatment period. Hens responded to APH and APC treatments with increased alertness, decreased preening behaviour and a reduction in eye temperature. No such changes occurred during any control period. Increased heart rate and maternal vocalization occurred exclusively during the APC treatment, even though chicks produced few distress vocalizations. The pronounced and specific reaction observed indicates that adult female birds possess at least one of the essential underpinning attributes of empathy.  相似文献   

4.
Shear stress, hormones like parathyroid and mineral elements like calcium mediate the amplitude of stimulus signal, which affects the rate of bone remodeling. The current study investigates the theoretical effects of different metabolic doses in stimulus signal level on bone. The model was built considering the osteocyte as the sensing center mediated by coupled mechanical shear stress and some biological factors. The proposed enhanced model was developed based on previously published works dealing with different aspects of bone transduction. It describes the effects of physiological doses variations of calcium, parathyroid hormone, nitric oxide and prostaglandin E2 on the stimulus level sensed by osteocytes in response to applied shear stress generated by interstitial fluid flow. We retained the metabolic factors (parathyroid hormone, nitric oxide and prostaglandin E2) as parameters of bone cell mechanosensitivity because stimulation/inhibition of induced pathways stimulates osteogenic response in vivo. We then tested the model response in terms of stimulus signal variation versus the biological factors doses to external mechanical stimuli. Despite the limitations of the model, it is consistent and has physiological bases. Biological inputs are histologically measurable. This makes the model amenable to experimental verification.  相似文献   

5.
The capacity of animals to empathise is of high potential relevance to the welfare of group-housed domestic animals. Emotional empathy is a multifaceted and multilayered phenomenon which ranges from relatively simple processes such as emotional matching behaviour to more complex processes involving interaction between emotional and cognitive perspective taking systems. Our previous research has demonstrated that hens show clear behavioural and physiological responses to the mild distress of their chicks. To investigate whether this capacity exists outside the mother/offspring bond, we conducted a similar experiment in which domestic hens were exposed to the mild distress of unrelated, but familiar adult conspecifics. Each observer hen was exposed to two replicates of four conditions, in counterbalanced order; control (C); control with noise of air puff (CN); air puff to conspecific hen (APC); air puff to observer hen (APH). During each test, the observer hens' behaviour and physiology were measured throughout a 10 min pre-treatment and a 10 min treatment period. Despite showing signs of distress in response to an aversive stimulus directed at themselves (APH), and using methodology sufficiently sensitive to detect empathy-like responses previously, observer hens showed no behavioural or physiological responses to the mild distress of a familiar adult conspecific. The lack of behavioural and physiological response indicates that hens show no basis for emotional empathy in this context.  相似文献   

6.
Event-related functional magnetic resonance imaging is a recent and popular technique for detecting haemodynamic responses to brief stimuli or events. However, the design of event-related experiments requires careful consideration of numerous issues of measurement, modelling and inference. Here we review these issues, with particular emphasis on the use of basis functions within a general linear modelling framework to model and make inferences about the haemodynamic response. With these models in mind, we then consider how the properties of functional magnetic resonance imaging data determine the optimal experimental design for a specific hypothesis, in terms of stimulus ordering and interstimulus interval. Finally, we illustrate various event-related models with examples from recent studies.  相似文献   

7.
Plasma concentrations of prolactin (Prl), glucose, corticosterone, and D(-)-3-hydroxybutyrate (DBHB) were compared in nonlaying, nonincubating turkey hens subjected to feed and/or water deprivation. Neither Prl nor corticosterone concentrations were significantly (P greater than 0.05) altered by any of the treatments, whereas fasting significantly (P less than 0.05) reduced the concentration of glucose and increased the concentration of DBHB. Plasma levels of Prl in incubating hens were significantly (P less than 0.05) reduced by nest deprivation either in the absence of feed and water or when the hens were force-fed the normal intake for a laying hen. After 48 h of nest deprivation, the hens resumed nesting within 5 min of being returned to the pen although the plasma levels of Prl were low. Neither nest attentiveness nor the concentration of Prl were affected by force-feeding the hens while they were incubating eggs. The concentration of glucose increased in response to force-feeding or nest deprivation, whereas the concentration of corticosterone was increased only by force-feeding. These results suggest that Prl may not be involved in the striking changes in both intermediary and water metabolism which occur during incubation in the turkey hen. Furthermore, since incubation behavior can occur in the presence of low concentrations of Prl, elevated levels of Prl during broodiness appear to be maintained by a stimulus associated with the nest itself or some other aspect(s) of the environment.  相似文献   

8.
Ren G  Chen X  Yu B 《Current biology : CB》2012,22(8):695-700
HEN1-mediated 2'-O-methylation has been shown to be a key mechanism to protect plant microRNAs (miRNAs) and small interfering RNAs (siRNAs) as well as animal piwi-interacting RNAs (piRNAs) from degradation and 3' terminal uridylation [1-8]. However, enzymes uridylating unmethylated miRNAs, siRNAs, or piRNAs in hen1 are unknown. In this study, a genetic screen identified a second-site mutation hen1 suppressor1-2 (heso1-2) that partially suppresses the morphological phenotypes of the hypomorphic hen1-2 allele and the null hen1-1 allele in Arabidopsis. HESO1 encodes a terminal nucleotidyl transferase that prefers to add untemplated uridine to the 3' end of RNA, which is completely abolished by 2'-O-methylation. heso1-2 affects the profile of u-tailed miRNAs and siRNAs and increases the abundance of truncated and/or normal sized ones in hen1, which often results in increased total amount of miRNAs and siRNAs in hen1. In contrast, overexpressing HESO1 in hen1-2 causes more severe morphological defects and less accumulation of miRNAs. These results demonstrate that HESO1 is an enzyme uridylating unmethylated miRNAs and siRNAs in hen1. These observations also suggest that uridylation may destabilize unmethylated miRNAs through an unknown mechanism and compete with 3'-to-5' exoribonuclease activities in hen1. This study shall have implications on piRNA uridylation in hen1 in animals.  相似文献   

9.
主要从湖北沙湖湿地自然保护区白尾鹞(Circus cyaneus)的生境偏爱和影响因子两方面分析中国东南部越冬区白尾鹞的种群动态。方差分析表明:年度间白尾鹞丰富度差异不显著。T检验表明:4a季节间白尾鹞丰富度差异极显著,秋季高于冬季。方差分析表明:4种生境中白尾鹞的丰富度存在极显著差异,草甸芦苇农田水域。4种生境中白尾鹞丰富度变异系数为:草甸水域芦苇农田。草甸生境是白尾鹞相对较好的越冬生境。多独立样本非参数检验(Kruskal-Wallis H法)表明:4种生境中雀形目鸟类和环颈雉的丰富度均存在极显著差异。多元线性回归模型(Enter进入法)显示:白尾鹞丰富度与其捕食对象丰富度在芦苇和草甸生境中呈强正相关,在农田和水域生境中相关性不显著。虚拟线性回归模型(Enter进入法)表明:草甸中的影响因子极显著的影响草甸中白尾鹞的丰富度。方差分析表明:草甸中白尾鹞的丰富度随草甸面积的下降而显著性下降。T检验表明:围网对白尾鹞在水域生境出现频次无显著影响。  相似文献   

10.
11.
Campylobacter isolated from feces and from the oviduct of six broiler breeder hens were genotyped by using flaA SVR DNA sequence analyses. A diversity of genotypes was observed among fecal and oviduct isolates. Comparison of isolates from the oviducts of individual hens revealed variable results. In three cases (hen 2, hen 3, and hen 6), analyses indicated that isolates from all regions of the individual hen's reproductive tract were closely related; isolates from hen 1 and hen 4 were diverse. Comparison of the Campylobacter isolates between hens revealed that in two cases, hens 1 and 3 and hens 4 and 6, certain isolates possessed identical flaA SVR sequence types. Comparisons of Campylobacter isolates recovered from a distinct region of the oviduct were found to have increased diversity as sampling progressed down the oviduct. This study further demonstrates that Campylobacter is present within the reproductive tract of breeder hens and that this presence may enable vertical transmission of Campylobacter from the breeder hen to the broiler offspring.  相似文献   

12.
High density lipoproteins were isolated from plasma of white Leghorn hens by ultracentrifugal flotation between densities 1.063 and 1.210 g/ml. After delipidation, the lipid-free proteins were fractionated by chromatography on Sephadex G-150 in urea; one major apolipoprotein was isolated and characterized. From its chemical, physical and immunochemical properties, the major apoprotein from hen high-density lipoproteins has characteristics similar to the major apoprotein of human high density lipoproteins, apoA-I. Thus the hen protein has been designated hen apoA-I. Hen apoA-I has a molecular weight of approximately 28 000 as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. Its calculated molecular weight from its 234 constituent amino acids is 26 674. Hen apoA-I differed from its human counterpart by containing isoleucine. Treatment of hen apoA-I with carboxypeptidase A yielded a COOH-terminal sequence of Leu-Val-Ala-Gln. Automatic Edman degradation of the apoprotein gave an NH2-terminal sequence of Asp-Glu-Pro-Gln-Pro-Glu-Leu. Hen apoA-I had a circular dichroic spectrum typical of alpha-helical structures; the calculated helicity was 90%. Goat antisera prepared to hen apoA-I formed precipitin lines of complete identity to the hen apoprotein but lines of only partial identity to human apoA-I. These studies show that the major apoprotein from hen and human high-density lipoproteins have similar properties to each other suggesting a common physiologic function.  相似文献   

13.
An expression plasmid for hen egg-white lysozyme in Saccharomyces cerevisiae was constructed by inserting almost full-length cDNA (about 600 base pairs) encoding hen egg-white pre-lysozyme into a yeast expression vector, pAM 82. The hen lysozyme was expressed under the control of the repressible acid phosphatase promoter of pAM 82 in S. cerevisiae. About half of the expressed lysozyme was secreted in the yeast growth medium as a precise mature protein which exhibited specific activity consistent with that of authentic hen egg-white lysozyme. The replacement of Trp 62 of hen egg-white lysozyme with a tyrosine residue was performed by site-directed mutagenesis using a 19-mer oligodeoxyribonucleotide. The mutant lysozyme with Tyr 62 was found to exhibit enhanced bacteriolytic activity.  相似文献   

14.
The binding constants of alpha- and beta-GlcNAc to hen and turkey lysozymes [EC 3.2.1.17] were determined at various pH's using the method proposed by Ikeda and Hamaguchi (1975) J. Biochem. 77, 1-16). The pH dependence of the binding of beta-GlcNAc to hen lysozyme was essentially the same as that for turkey lysozyme. The pH dependence curves of the binding constants of beta-GlcNAc to hen and turkey lysozymes were interpreted in terms of the participation of Glu 35 (pK 6.0), Asp 52 (pK 3.5), Asp 48 (pK 4.5), and Asp 66 (pK 1.5). The binding constants of alpha-GlcNAc to hen and turkey lysozymes were the same below pH 3.5 but were different above this pH. The main participant residues in the binding of alpha-GlcNAc were Glu 35, Asp 48, and Asp 66 for hen lysozyme and Glu 35 and Asp 66 for turkey lysozyme. The results obtained here were well explained by the following assumptions: (1) above about pH 4, alpha-GlcNAc binds to hen lysozyme in both alpha- and beta-modes, which correspond to the binding orientation of alpha-GlcNAc and that of beta-GlcNAc, respectively, as determined by X-ray crystallographic studies, but it binds predominantly in the beta-mode below about pH 4, (2) beta-GlcNAc binds to hen and turkey lysozymes predominantly in the beta-mode above about pH 4 and in both alpha- and beta-modes below pH 4, and (3) alpha-GlcNAc binds to turkey lysozyme predominantly in the beta-mode over the whole pH range studied.  相似文献   

15.
Human lysozyme and hen egg-white lysozyme have antibacterial, antiviral, and antifungal properties with numerous potential commercial applications. Currently, hen egg-white lysozyme dominates low cost applications but the recent high-level expression of human lysozyme in rice could provide an economical source of lysozyme. This work compares human lysozyme and hen egg-white lysozyme adsorption to the cation exchange resin, SP-Sepharose FF, and the effect of rice extract components on lysozyme purification. With one exception, the dynamic binding capacities of human lysozyme were lower than those of hen egg-white at pH 4.5, 6, and 7.5 with ionic strengths ranging from 0 to 100 mM (5-20 mS). Ionic strength and pH had a similar effect on the adsorption capacities, but human lysozyme was more sensitive to these two factors than hen egg-white lysozyme. In the presence of rice extract, the dynamic binding capacities of human and hen egg-white lysozymes were reduced by 20-30% and by 32-39% at pH 6. Hen egg-white lysozyme was used as a benchmark to compare the effectiveness of human lysozyme purification from transgenic rice extract. Process simulation and cost analyses for human lysozyme purification from rice and hen egg-white lysozyme purification from egg-white resulted in similar unit production costs at 1 ton per year scale.  相似文献   

16.
The interactions of the substrate analogues, GlcNAc, beta-methyl GlcNAc, (GlcNAc)2, and (GlcNAc)3, with turkey egg-white lysozyme [ED 3.2.1.17], in which the Asp 101 of hen lysozyme is replaced by Gly, were studied at various pH values by measuring changes in the circular dichroic (CD) band at 295 nm. Results were compared with those for hen egg-white lysozyme. The modes of binding of these substrate analogues to turkey lysozyme were very similar to those hen lysozyme except for the participation of Asp 101 in hen lysozyme. The ionization constants of the catalytic carboxyls, Glu 35 and Asp 52, in the turkey lysozyme-(GlcNAc)3 complex were determined by measuring the pH dependence of the CD band at 304 nm, which originates from Trp 108 near the catalytic carboxyls. The ionization behavior of the catalytic carboxyls of turkey lysozyme in the presence and absence of (GlcNAc)3 was essentially the same as that for hen lysozyme. The pH dependence of the binding constant of (GlcNAc)3 to hen lysozyme was compared with that to turkey lysozyme between pH 2 and 8. The pH dependence of the binding constant for (GlcNAc)3 to turkey lysozyme could be interpreted entirely in terms of perturbation of catalytic carboxyls. In the case of hen lysozyme, it was interpreted in terms of perturbation of the catalytic carboxyls and Asp 101 in the substrate-binding site. The pK values of Asp 101 in hen lysozyme and the hen lysozyme-(GLcNAc)3 complex were 4.5 and 3.4, respectively. The binding constants of (GlcNAc)3 to lysozyme molecules with different microscopic protonation forms, with respect to the catalytic carboxyls, were estimated. The binding constant of lysozyme, in which Asp 52 and Glu 35 are deprotonated, to (GlcNAc)3 was the smallest. The other three species had similar binding constant to (GlcNAc)3.  相似文献   

17.
Changes of the estradiol and lipid concentrations in hen serum, and those in the fatty acids of hen and cockerel livers were studied during the maturing period. The concentrations of estradiol and lipid in serum reached a maximum level a few days before the onset of laying, and then fell. A marked increase in oleate, and decreases in stearate and arachidonate were observed in both the liver and serum lipids of the hen when reaching laying. The fatty acid compositions of the serum and liver of the hen at 145 and 167 days of age were close to those of yolk lipid. In the cockerel, high contents of stearate and arachidonate and a low content of oleate were observed, and the fatty acid composition did not change appreciably with age. On estrogenization of the male chick, the fatty acid cmposition of the liver lipid was similar to that of the laying hen liver. The ratio of the unsaturated fatty acid/saturated fatty acid in the liver of hen increased when reaching laying, the value at 167 days old being close to that of yolk lipid. This ratio in the liver lipid of cockerel did not change significantly throughout the experimental period.  相似文献   

18.
A comparative analysis of chromatin from erythrocytes of frog, trout and hen has been performed in correlation with properties of the nucleosomal linker histones of H1 family. In the nucleosomes from frog erythrocytes the linker histone is represented by H1(0)-like variant with amino acid sequence highly homologous to that of the hen histone H5, however the arginine content in the proteins differs (3 mol% in the frog erythrocyte H1 and 12 mol% in the hen erythrocyte H5). On the other hand histone H5 from trout being significantly different in the primary structure from the hen histone H5 is at the same time rich in arginine (9 mol%). The nucleosomal repeat length, estimated by using agarose gel electrophoresis is 201, 213 and 213 b.p. in erythrocyte chromatin from frog, trout and hen, correspondingly. Chromatin packing density in fixed nuclei from erythrocytes of frog, trout and hen as determined using cytophotometric measurements is 0.144, 0.444 and 530 pg/mu 3, correspondingly. The data support the previously made suggestion that the increase in arginine content in nucleosomal linker proteins is connected with the increase of chromatin compaction in the nuclei and elongation of the linker in the nucleosome.  相似文献   

19.
Studies have been made on interaction between rabbit antiserum to BB creatine kinase from hen gizzard and BB creatine kinases from the brain, heart and gizzard of hen. The degree of interaction was evaluated by the intensity of fluorescence of the immune complexes labeled by a fluorescent dye. It was shown that the intensity of fluorescence of the immune complexes formed by BB creatine kinases from the brain and gizzard of hen is approximately the same, whereas that formed by BB creatine kinase from the heart is twice lower. The data obtained indicate that structural differences in the region of antigenic determinants exist between BB creatine kinase from the heart and those from the brain and gizzard of hen.  相似文献   

20.
Population introduction is an important tool for ecosystem restoration. However, before introductions should be conducted, it is important to evaluate the genetic, phenotypic and ecological suitability of possible replacement populations. Careful genetic analysis is particularly important if it is suspected that the extirpated population was unique or genetically divergent. On the island of Martha's Vineyard, Massachusetts, the introduction of greater prairie chickens (Tympanuchus cupido pinnatus) to replace the extinct heath hen (T. cupido cupido) is being considered as part of an ecosystem restoration project. Martha's Vineyard was home to the last remaining heath hen population until its extinction in 1932. We conducted this study to aid in determining the suitability of greater prairie chickens as a possible replacement for the heath hen. We examined mitochondrial control region sequences from extant populations of all prairie grouse species (Tympanuchus) and from museum skin heath hen specimens. Our data suggest that the Martha's Vineyard heath hen population represents a divergent mitochondrial lineage. This result is attributable either to a long period of geographical isolation from other prairie grouse populations or to a population bottleneck resulting from human disturbance. The mtDNA diagnosability of the heath hen contrasts with the network of mtDNA haplotypes of other prairie grouse (T. cupido attwateri, T. pallidicinctus and T. phasianellus), which do not form distinguishable mtDNA groupings. Our findings suggest that the Martha's Vineyard heath hen was more genetically isolated than are current populations of prairie grouse and place the emphasis for future research on examining prairie grouse adaptations to different habitat types to assess ecological exchangeability between heath hens and greater prairie chickens.  相似文献   

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