首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Output analysis and input-output experiments had given evidence for five sequential effects occuring independently of each other in the singing behavior of blackbirds (Fig.1). Recently these investigations resulted in a model which summarized the interaction of five functional components evaluated from the found effects; thereby the model explained the data processing controlling the sequential patterning of the behavior (Fig. 2) — During the investigations reported here, this model and alternative models were tested by means of computer programs. Main question: Would the models generate sequences of patterns equivalent to the sequence of vocal patterns produced by a blackbrid? Results:
  1. Only the original one of the tested models generated sequences of patterns showing the specific regularities and their characteristic variations corresponding to natural blackbird songs. This brought evidence for a multiplicative mode of interaction between the “component of throttling-back” (Drosselungskomponente) and the other four components; furthermore for a terminal functioning of the “extreme-value-passage” (Extremwertdurchlaß) (Figs, 2–4 and 10).
  2. Concerning the “component of periodicity” (Periodikkomponente) the mechanism of a “reset of periods” was falsified while the mechanism of a “continued periodicity” could be made evident. This implied: The periodicity of the single pattern (phrase) runs over the course of the whole song: the proceeding of the oscillation takes place with each output realisation (Fig. 5).
  3. Variations of values of the particular parameters given to the different components during the testing programs showed that a) extreme values resulted in “unnatural” sequences of patterns; b) only values lying within distinct intervals generated sequences containing the whole set of the postulated effects; c) exactly with those parameter values, with which one of the effects could get produced in a natural form, also the other effects were generated correspondingly optimal (Figs. 6–8).
  4. The differential variation of the values of the particular parameters given to the components (during the testing programs) allowed a lot of predictions concerning the consequences of increasings or decreasings in the strength of the different components. These predictions have to be tested by experiments with natural systems (blackbirds) (Fig. 9; Tables 1–3).
  相似文献   

2.
A. Béjin 《Andrologie》1997,7(3):336-342
We provide data on several aspects of sexual behaviour: masturbation, age at first intercourse, sexual practices during first intercourse, homosexuality and heterosexuality, sexual practices over a lifetime, sexual activity in the past twelve months, frequency of sexual intercourse, last sexual intercourse, achieving orgasm (through vaginal penetration, masturbation by partners, fellatio and cunnilingus), sexual dysfunctions. Data come from recent national sex surveys in: Great Britain (1990–91; n=18.876), Finland (1991–92; n=2250), the United States (1992; n="3432) and especially from the ACSF survey (n=20.055), the French national telephone survey on sexual behaviour conducted between September 1991 and February 1992. Some results about the prevalence of sexual dysfunctions in sexually active men 18 to 69 years old, in France (in %):
  • - “You do not have an erection (impotence)”
  • - “often”: 7%, “sometimes”: 12%
  • -“You ejaculate too early, even before entering you partner” “often”: 5%; “sometimes”: 16%
  • - “You ejaculate too soon, upon or shortly after entering your partner” “often”: 10%; “sometimes”: 27%
  • - “It takes you too long to ejaculate once you have entered your partner” “often”: 4%; “sometimes”: 16%
  • - “You fail to ejaculate at all” “often”: 2%; “sometimes”: 5%
  • - “You don't have an orgasm” “often”: 7%; “sometimes”: 7%
  • - “You feel no or insufficient sexual desire” “often”: 3%; “sometimes”: 16%.
  •   相似文献   

    3.
    We analyzed the response of the vibration sensitive lyriform organ on the metatarsus of female spiders (Cupiennius salei) to dummies of male courtship vibrations. One of the two representative slits studied is sharply tuned to 500 Hz. Only the other slit is sensitive enough at lower frequencies to represent the parameters contained in the behaviourally effective dummies:
    1. Amplitude. The physiological threshold is similar to the behavioural threshold. The stimulus acceleration amplitudes leading to a good synchronization between response and temporal stimulus pattern coincide with those effectively eliciting a behavioural response. The most frequent spike intervals remain nearly constant in this range. At acceleration amplitudes above the natural range, syllable and pause durations are misrepresented by the receptor response.
    2. Frequency. Varying the carrier frequency between 35–500 Hz changes the most frequent spike intervals. Interval histograms resulting from behaviourally effective stimuli (50–200 Hz), however, are similr for carrier frequencies differing by a factor of 2.
    3. Temporal pattern. Response duration reflects the temporal parameters of the stimulus. The most frequent spike interval only changes with temporal stimulus characteristics far off the natural range. The number of spikes during a syllable decreases in ongoing stimulus series. The quality of copying the temporal stimulus pattern remains unchanged, however.
      相似文献   

    4.
    Rock lobsters are able to perform long and stereotyped stepping sequences above a motor driven treadmill. Forward walking samples are estimated by mean of statistical methods to draw out the basic rules involved in the locomotor behaviour (Fig. 1).
  • - The spatial and temporal parameters defined in a single propulsive leg are either invariable in respect to the imposed speed, as the mean step length (L), the return stroke duration (Tr) and the pause times (T's, T'r), or speed dependent as the power stroke duration (Ts) and the whole period (Figs. 2 and 3).
  • - The interleg phase coupling is strong and stable in the ipsilateral rear pairs (4–5), these legs acting most of the time in absolute coordination (1:1) or in harmonic ratio (2:1). In the contralateral pairs (R4-L4, R5-L5) the legs roughly operate in antiphase, but the relationship appears much weaker and variable, with frequent episodes of relative coordination (Fig. 4).
  • - The time intervals between the ground contact of any leg and the swing initiation in the nearest ones appear somewhat constant and could be closely related to the mechanism of stepping synchronization. The “5 on - 4 off” delay, very stable and always positive, suggests that the rear legs could exert a predominant influence upon the rhythmical movements of the next anterior ipsilateral appendages (Fig. 5).
  • - To test the contralateral relationships, the treadmill belts can be decoupled in order to impose different walking speeds on each side. Such a conflicting stimulus reveals that:
    1. The relative hierarchy always observed between the ipsilateral legs can be artificially created between the two sides (Fig. 6).
    2. The driving influence of a given leg is closely linked to the intensity of EMG's discharges in its power stroke muscles.
    3. The contralateral appendages are able to walk in absolute coordination despite a large speed difference between the two sides (up to 4 cm/s). Under such a constraint, the walking legs alter its invariable parameters (L and Tr) to reach a common step period and steadily maintain the alternating pattern (Figs. 6 and 7).
  •   相似文献   

    5.
    1. We developed a high resolution, on-line stimulus measurement system for accurate control of chemical stimulus applications for Homarus americanus lateral antennule chemoreceptors. Focal stimulus presentations in an electrophysiological preparation with the receptor sensilla intact were measured at small spatial (30 μm) and time (5 ms) scales.
    2. We tested 15 receptor cells with ten 100 ms pulses of 104 M hydroxyproline at 0.5, 1, 2 and 4 Hz and with a single 8 s square pulse. Individual cells showed differences in their capabilities to resolve pulses (“flicker fusion”). At 2 Hz stimulation, some cells could follow stimulus pulses while others could not. At 4 Hz, 3 cells could still encode individual stimulus pulses accurately. The population resolved pulses up to 2 Hz; at 4 Hz, the population response to a pulse series approximated the response to a square pulse.
    3. Repetitive stimulation caused a gradual decrease in the number of spikes and a gradual increase in first spike latency (“cumulative adaptation”). Increased stimulation frequency resulted in greater cumulative adaptation.
    4. Since individual differences in adaptation and disadaptation rates of the receptor cells could not be attributed to measured stimulus variability in situ, lobster chemoreceptor cell populations have intrinsic temporal diversity which, we hypothesize, could be used to analyze pulsatile stimuli that occur in natural turbulent odor plumes.
      相似文献   

    6.
    The landing response of stationary flying houseflies Musca domestica has been recorded on video tape. The leg movements were quantitatively evaluated. It could be demonstrated that:
    1. only the first two pairs of legs are involved in the reaction (Fig. 1). Prothoracic tarsi are lifted beyond the head, mesothoracic tarsi are lowered and moved sidewards (Fig. 2a and b).
    2. the movement of the tarsal tips is mainly due to an opening of one single joint per leg, i.e. the femurtibia joint of the prothoracic leg (Fig. 2c), and the coxa-femur joint of the mesothoracic leg.
    3. the landing reaction is a fixed action pattern which does not seem to require further sensory input once it is released (Fig. 4d).
    4. the landing responses to a light-off stimulus and to expanding patterns with different angular velocities are indistinguishable (compare Fig. 3a-c with Fig. 2a-c). The only parameter that is obviously dependent on the stimulus conditions, is the latency of the reaction (Fig. 4a-c).
      相似文献   

    7.
    1. The ontogeny of positive phono taxis (PPT) in female crickets, Gryllus bimaculatus was followed in tethered flight. During the first day of adult life many females already demonstrated PPT to the calling song (CS) of conspecific males. The average threshold of PPT at 5 kHz, the dominant frequency of the CS, decreased by 30 dB by the time of sexual maturity (Fig. 1).
    2. No correlates of this decrease were found in the activity of the most sensitive ascending prothoracic neuron tuned to 5 kHz recorded in the neck connective. This is presumably the AN1 neuron which is known to be involved in PPT realization. Its threshold at 5 kHz in young animals was the same as in adults. Therefore, ascending circuits of PPT seem to be mature by the first day of imago life and there should be some other mechanisms preventing performance of PPT by young walking females until maturation.
    3. The PPT of females in flight is tuned to 5 kHz, much sharper than in walking (Fig. 2). In flight, the carrier frequency of a signal is probably an important parameter driving PPT, at least in a no-choice situation, whereas on the substrate, at close range, temporal parameters become decisive.
    4. The ontogenetic development of the selectivity of a female's PPT to temporal parameters of a signal passes 3 successive steps: 1) response mainly to the trill with pulse repetition rate as in the CS; 2) response mainly to the actual CS with chirp structure; 3) destruction of selectivity (Figs. 3–6). The existence of steps 1 and 2 strengthens our hypothesis, that in phylogeny, the trill (pulse rate) detector of the CS “recognizer” in the CNS appeared earlier, and was later accompanied by the chirp detector.
    5. Joint breeding of female larvae with males accelerates maturation of the CS recognizer.
      相似文献   

    8.
    Species, endowed with an open-ended capacity for learning, which is one of the highest evolutionary achievements,will profit most from this ability, if they are urged one way or other to invest any surplus of energy in expanding and refining their behavioural repertoire and in adapting it to prevailing circumstances, while incurring as little risk and stress as possible. It is therefore argued that an open-ended capacity for learning is maximally adding to survival if paired to two distinct tendencies:
    1. a tendency to seek high-arousal evoking situations whenever surplus energy is available, and
    2. a tendency to seek arousal reducing situations as soon as the surplus energy is exhausted.
    This suggests that a bi-stable “telic/paratelic” system of prefered levels of arousal, as described for humans by Apter & Smith's theory of motivational reversals, and as expressed in Kortmulder's model of the “centripetal/centrifugal” bi-polarity of animal behavioural tendencies, can be considered an Evolutionarily Stable Strategy (E.S.S.), as compared to homeostatic systems of arousal and motivation.  相似文献   

    9.
    Colour preferences of flower-naive honeybees   总被引:1,自引:0,他引:1  
    Flower-naive honeybees Apis mellifera L. flying in an enclosure were tested for their colour preferences. Bees were rewarded once on an achromatic (grey, aluminium or hardboard), or on a chromatic (ultraviolet) disk. Since naive bees never alighted on colour stimuli alone, a scent was given in combination with colour. Their landings on twelve colour stimuli were recorded. Results after one reward (“first test”) were analysed separately from those obtained after few rewards (“late tests”).
    1. After pre-training to achromatic signals, bees preferred, in the first test, bee-uv-blue and bee-green colours. With increasing experience, the original preference pattern persisted but the choice of bee-blue and bee-green colours increased.
    2. Neither colour distance of the test stimuli to the background or to the pre-training signal, nor their intensity, nor their green contrast, accounted for the colour choice of bees. Choices reflected innate preferences and were only associated with stimulus hue.
    3. Bees learned very quickly the pre-trained chromatic stimulus, the original colour preferences being thus erased.
    4. Colour preferences were strongly correlated with flower colour and its associated nectar reward, as measured in 154 flower species.
    5. Colour preferences also resemble the wavelength dependence of colour learning demonstrated in experienced bees.
      相似文献   

    10.
    1. All giant interneurons (GIs) were ablated from the nerve cord of cockroaches by electrocautery, and escape behavior was analyzed with high-speed videography. Animals with ablations retained the ability to produce wind-triggered escape, although response latency was increased (Table 1, Fig. 4). Subsequent lesions suggested that these non-GI responses depended in part on receptors associated with the antennae.
    2. Antennal and cereal systems were compared by analyzing escape responses after amputating either cerci or antennae. With standard wind stimuli (high peak velocity) animals responded after either lesion. With lower intensity winds, animals lost their ability to respond after cereal removal (Fig. 6).
    3. Removal of antennae did not cause significant changes in behavioral latency, but in the absence of cerci, animals responded at longer latencies than normal (Fig. 7).
    4. The cercal-to-GI system can mediate short latency responses to high or low intensity winds, while the antennal system is responsive to high intensity winds only and operates at relatively longer latencies. These conclusions drawn from lesioned animals were confirmed in intact animals with restricted wind targeting the cerci or antennae only (Fig. 9).
    5. The antennae do not represent a primary wind-sensory system, but may have a direct mechanosensory role in escape.
      相似文献   

    11.
    In grasshoppers the acoustic information for pattern recognition and directional analysis is processed via parallel channels and not serially. This can be concluded from the following results established by behavioural experiments:
    1. For pattern recognition the inputs from both sides are added internally. This implies that directional information is lost on this channel and must be processed in parallel.
    2. The location of a female song can be influenced by introducing short clicks from both sides, forcing the grasshopper to turn to the louder resp. leading side. Also, when given a choice between two patterns of different efficiency, the grasshoppers turned towards the side with the stronger directional cues and not to the side with the more efficient pattern.
    3. The parallel processing of acoustic information in grasshoppers corresponds to the evolution of acoustic communication in Acridids, as song evolved only when the ability of hearing and localization was already present. This is in contrast to crickets where the close evolutionary coupling of singing and hearing in the context of mate finding possibly favoured a serial processing of song recognition and localization.
      相似文献   

    12.
    A novel approach has been introduced to detect the manifestation of symmetry breaking weak interactions at molecular level. In the racemic conglomerate crystallization of D, L-sodium-ammonium tartrate the effect of32P irradiation was studied by measuring the weight and optical purity of the crystalline phase as well as the size distribution of the crystallites. The high number of independent experiments (over 1000) permitted statistical analysis of the results. The following observations have been made:
    1. Beta irradiation influences the crystallization process, irradiated samples yield more crystalline material.
    2. The effect involves presumably crystal seed formation because from the irradiated solutions more and smaller crystallites are formed.
    3. The presence of beta particles induces stereoselective crystallization, the crystalline phase shows optical activity characteristic of the “unnatural” L-isomer.
    4. The above changes are attributed to the beta irradiation as the magnitude of the effects depends on the amount of added radioactivity. Optically active contaminants are highly unlikely sources of the differences between irradiated and control series.
    5. In the absence of32P the tartrate enantiomers have equal probability to form crystals, i.e., the contribution of mixing of weak interaction into the electromagnetic one is not measurable in this system.
      相似文献   

    13.
    A critical review on fossil Hydrozoa reveals the following questions and problems:
    1. Microstructure, skeleton formation and morphology: According toKazmierczak’s morphogenetical model the formation of the ectodermal basal skeleton depends on a progressive folding of the coenosarc. Can this model be used for all polypoid hydrozoans? Another very important question deals with the possibility of distinctions between systematically important “primary” microstructures and taxonomically worthless “secondary” microstructures which are produced by diagenetical alteration effects.
    2. Determination and classification: There is no general agreement on the morphological elements which can be used for the definition of Paleozoic and Mesozoic stromatoporoid genera and species, special problems refer to the taxonomical value of the astrorhizae and of quantitative criteria. About 2000 “species“ from the Paleozoic and about 500 “species“ from the Mesozoic have been described within the Stromatoporoidea but there exists no generally recognized classification system for this group.
    3. Paleobiogeography: The oldest polypoid hydrozoans are known from Llanvirnian to Llandeiloverian reef- and shelf-carbonate-deposits; some species described from the Middle Cambrian of Western Sibiria may belong to Archaeocyatha. Tab. 3 shows the temporal distribution of hydrozoan groups. Stricking gaps of knowledge exist for Carboniferous and Permian, Lower Triassic, Liassic, Middle Jurassic and for Tertiary hydrozoan faunas.
    4. Palecology: Main factors governing the distribution of polypoid hydrozoans seem to be consistence of substrate, different types of water movement, and eventually differences in salinity. These ecofactors may be recognized by the interpretation of growth forms and growth patterns together with investigations of hydrozoan associations and communities. According to the problems mentioned above no sound evolutionary scheme of all hydrozoan groups is possible just now. Questions dealing with the systematical position of Paleozoic and Mesozoic Chaetetida and with the relationships between Hydrozoa and Sclerospongia have to be studied first (see page 406).
      相似文献   

    14.
    L. Wagner 《Andrologie》2001,11(3):117-120
    The management of patients with nonobstructive azoospermia must not be limited to testicular biopsy. A complete andrological assessment must be performed to adapt treatment to each patient, in order to:
  • -avoid testicular biopsy by screening for “azoospermia-like” syndromes and treat any etiological factors (pituitary hypogonadism, varicoceles, cryptorchidism), and concomitant aggravating factors (spermatic cord infection, obstructive factor of the epididymis or vas deferens).
  • -screen for clinical or subclinical testicular tumors and demonstrate genetic anomalies involving risks for the offspring.
  • -establish a prognosis regarding the possible use of medically-assisted reproduction by ICSI (intracytoplasmic sperm injection) with testicular spermatozoa.
  •   相似文献   

    15.
    • 1.1. Two “en passant” electrodes were implanted around the cerebrobuecal connective (CBC) of Aplysia and used to record the activity, in the unrestrained animal, under three behavioural conditions; (a) absence of feeding behaviour, (b) appetitive feeding behaviour and (c) consummatory feeding behaviour.
    • 2.2. The two simultaneous recordings were subjected to cross-correlation analysis, to subdivide spikes on the basis of their direction and speed of propagation.
    • 3.3. There was virtually no CBC activity in the absence of food and feeding behaviour.
    • 4.4. During appetitive feeding the metacerebral giant cell (MCC) was active and traffic was heaviest in the cerebral-to-buccal direction.
    • 5.5. During consummatory feeding, traffic was also sustained in the buccal-to-cerebral direction; there was a reduction in the activity of the MCC, and a peak in the activity travelling to the cerebral ganglia, in the region of higher conduction velocity, was especially pronounced.
    • 6.6. Further analysis showed this peak to have its largest amplitude during the actual ingestion of food and to be the result of the firing of several different units.
    • 7.7. CBC traffic in both directions was also activated in one case of “spontaneous” biting.
      相似文献   

    16.
    1. From 40 waters of the Abisko-district (Sweden, Lapland) 58 samples were collected (essentially samples from sediments).
    2. It is not possible to clear the origin of all discovered tests of sediments. The bottom of most waters was covered with mosses, from which vegetation, tests can come into the sediments. But also tests from other biotopes, can be found at the bottom.
    3. Nevertheless we can recognize typical characters of those species living in sediments. The prevalent type is the “Difflugia-type”. Those species of Centropyxis which immigrated into sediments demonstrate a trend towards the “Difflugia-type”. The immigration is possible from Aufwuchs, mosses and soils. 62,7% of the recorded tests belong to Difflugia, 17,8% to Centropyxis.
    4. The prevalent species in the sediments of the Abisko-district is Difflugia elegans var. teres, the next is D. glubolosa.
    5. A great number of investigated waters contained the oligotrophic species Centropyxis aërophila. Only one lake (Ruontenjaure) shows the association of dystrophic lakes.
    6. Some species are described taxonomically, for instance: Centropyxis nauwercki n.sp. C. nauwercki is very much like Difflugia, but is also connected with C. platystoma. The new species shows a trend from Centropyxis to Difflugia.
    7. C. aërophila can also immigrate into the Aufwuchs. There the species has membraneous tests.
    8. Geographical aspects of the sediment colonization are discussed.
      相似文献   

    17.
    1. Extracellular recordings from wide-field nonhabituating non-directional (ND) motion detecting neurons in the second optic chiasma of the locust Locusta migratoria are presented. The responses to various types of stepwise moving spot and bar stimuli were monitored (Fig. 1)
    2. Stepwise motion in all directions elicited bursts of spikes. The response is inhibited at stimulus velocities above 5°/s. At velocities above 10°/s the ND neurons are slightly more sensitive to motion in the horizontal direction than to motion in the vertical direction (Fig. 2). The ND cells have a preference for small moving stimuli (Fig. 3).
    3. The motion response has two peaks. The latency of the second peak depends on stimulus size and stimulus velocity. Increasing the height from 0.1 to 23.5° of a 5°/s moving bar results in a lowering of this latency time from 176 to 130 ms (Fig. 4). When the velocity from a single 0.1° spot is increased from 1 to 16°/s, the latency decreases from 282 to 180 ms (Figs. 5–6).
    4. A change-of-direction sensitivity is displayed. Stepwise motion in one particular direction produces a continuous burst of spike discharges. Reversal or change in direction leads to an inhibition of the response (Fig. 7).
    5. It shows that non-directional motion perception of the wide-field ND cells can simply be explained by combining self-and lateral inhibition.
      相似文献   

    18.
    1. Previous work on the methods employed for the determination of the breeding season of shipworms is briefly reviewed.
    2. The method adopted for studying the reproductive cycle by using the “gonad index” is described.
    3. The reproductive cycle of Nausitora hedleyi is described in detail based on a study of the gonad index of different sexes collected at monthly intervals from the estuarine environment of Cochin harbour.
    4. The fact that breeding is restricted as marked by seasonal activity is shown from the size and activity of the gonad during the different months of the year.
    5. The environment, and the hydrographic conditions prevailing in the habitat of N. hedleyi in the Cochin harbour are described.
      相似文献   

    19.

    Introduction

    Atoms theory and symmetry theory dominated physics. Symmetry propagation and interactions verify the Curie principle. But its violation by symmetry breaking is spontaneous.Fragility is creative. An information breaks a generalized symmetry. Results on symmetry breakings are not valid for fuzzy symmetries. The breaking of a fuzzy symmetry leads only to a pour symmetry (Fig.1). Homogeneity breaking, and atom of time are not usual concepts. We examine in this work symmetry breakings which generate the living time.

    Relativistic Time-Space Breaking

    1. Medium and environment of living define ordinary referential of space and referential of time. Astronomical phenomena following classical mechanics and microphysical phenomena following quantum mechanics can be written with the same t coordinate.
    2. Relativity corrections. Schrödinger's Quantum mechanics (Eq.0) approximately governs molecular systems (Relativity corrections can be expressed as physical effects in the above defined referential).
    3. Time reversal symmetry. The well-known Wigner's transformation determines the microscopic reversibility.
    4. The three essential particle-vacancy equilibria. This transformation is verified by all particle-vacancy reciprocity. Vacancy moves like particle but with negative moment and positive kinetic energies. Only three biochemical equilibria admit this time reversal symmetry, namely: oxydo-reduction, acido-basicity, fluidity-viscosity. In these case, reacting electron, solvated proton, water molecule are respectively antagonist of the corresponding vacancy.
    5. Fuzzy character of time reversal symmetry. Dirac's equation does not admit this symmetry which only appears at the “non relativistic” limit of quantum phenomena. Hence particle-vacancy reciprocity is fuzzy according to the experimental evidence. (Laforgue et al., 1988).

    Oriented Time

    1. From the universal reversible time, an additional breaking generates the oriented time, both in the astronomical and in the living matter.
    2. Irreversibility for the environment. We refer to Prigogine and Stengers (1988).
    3. Irreversibility for the living matter. We refer to Lochak (1986). Because equation (0), above discussed, is “microreversible” the second breaking could come from an additional term vanishing in the stationary states but increasing with time in evolutionary processes.
    4. Negative times. Taking into account the fuzzy character of the time reversed symmetry, the third breaking cannot suppress completely the occurrence of negative times. Reversed time is controlled by direct time. Except in the three above reported cases, time reversal symmetry is not verified by the medium. Free motion of the particle following eg.(0) or of the vacancy following time reversal reciprocal equation takes place only during short jumps from an interaction site to an other. Fig. 2 schematizes the law of motion of the electric charge corresponding to the transport by proton or by proton vacancy in an unitary field (fluctuations are neglected). The reserved jumps are estimated in the range of 10?12s. It is not excluded that such a jump can control a direct phenomenon.
    5. The living time. Biological phenomenon appears as an oriented set of events. Nevertheless latency or exaltation phases could be perceived. This modulation could be described by positive and negative times additional to the basic time. (Negative can be interpreted as above)

    Living produces Time

    1. That were not understandable, if time was only a frame, in which change occurs. Taking chance as frame and time as effect, we regard biological activity as integrating reversible and irreversible time. Living synchronizes internal and external time by its own effort as it results (Lestienne, 1990) from Chronobiology.
    2. Time modulation. Let us consider the dy1...dyi...dyp changes in the variables of the systems, dy={dyi} has produced dt. We proof (eq.(1) to (4)) that time is modulated by a φ(y) speed coefficient depending on the medium. tmodulated=tφ (y) ?1
    3. The production of reversible time (e.g.acido-basicity) determines time modulation. As above reported it remains some reversibility effects (jumps of negative time) which modulate time. E.G., if an important amount of reagent is necessary to modify an acid-base equilibrium, φ(y) is small.
    4. Time modulation and activation-repression reciprocity. As well-known, long tmodulated means repression, short tmodulated means exaltation. Extrema of ? are symmetrical because particle and vacancy are reciprocal. Nevertheless reciprocity is not perfect. E.g., on fig. 3, the wet receptor determines the cell increasing, the dry receptor the cell senescence of a certain alga (Lück, 1962).
    5. Irreversible time production. Medium accepts entropy. Hence it acts in the second breaking of time. Living extracts the free energy from the medium, like a dissipative structure. That insures an operative point far from the thermodynamical equilibrium.

    Consumption of Time

    1. The three followings correspond to the more trivial time consumption.
    2. Rhythmical time. Free energy flux is favourable to the arising of order in space or time. This later gives a structure to the living time.
    3. Mutual dependence of reversible time and rhythms. Time irreversible structure can be controlled by the above considered particle-vacancy equilibrium. Consequently the living time (modulated and structured) is a chemical time connected to molecular properties and to statistical thermodynamics. Practically, the connection between chronobiology and chemistry is important. The use of drugs could be interpreted as a response to an aggression against biorhythms.
    4. Lifetime. The dead-birth rythm can be broken in two ways: evolution or indefinite life. This later is non exceptional for the living matter, e.g. in the vegetals where it is connected with the chlorophyllic assimilation; the time reversal significance of which is evident.
    5. The plan of the alchemist. Indefinitely life has fascinated individuals. Do the human species becomes better adapted by a longer life?

    Conclusions

    1. Atoms of time could exist.
    2. Biological time is defined by the breaking of five generalized symmetries, namely: Minkovski's space symmetry, reversibility, homogeneity, rhythmicity, generations reproduction.
    3. Environment and medium determine non relativistic, oriented, structured time.
    4. At the microphysical scale, a fuzzy time reversal symmetry takes place, the breaking of which is not complete. Reversible time and dominating irreversible time are integrated in living phenomena.
    5. Three fundamental particle-vacancy reciprocities admit a part of reversibity. Irreversibility governs the all others phenomena.
    6. Time is produced chemically.
    7. A new perspective is the connection between chemical equilibria and rhythms including the time of the life.
      相似文献   

    20.
    1. The morphology of descending interneurons (DNs) which have arborizations in the lateral accessory lobe (LAL) of the protocerebrum, the higher order olfactory center, and have an axon in the ventral nerve cord (VNC), were characterized in the male silkworm moth, Bombyx mori.
    2. Two clusters (group I, group II) of DNs which have arborizations mainly in the LALs were morphologically characterized. The axons of these DNs are restricted to the dorsal part of the each connective (Figs. 1–5).
    3. Pheromonal responses of the group I and group II DNs were characterized. Flipflopping activity patterns, which have two distinct firing frequencies (high and low) in response to sequential pheromonal stimulation, were usually recorded (Figs.6–10).
    4. Two types of flipflopping activity patterns were classified into those that had an antiphasic relationship (called the ‘FF’ type) between the left and right connectives and those with a synchronized relationship (‘ff’ type) (Figs. 8–12). We propose that some group II DNs show ‘FF’ flipflopping activity patterns (Fig. 10).
    5. A state transition was usually elicited by less than 10 ng bombykol, the principal pheromone component. Extra impulses were elicited during constant light stimulation (Fig. 9).
    6. Our results suggest that the LAL olfactory pathways might be important for producing flipflopping activity patterns (Fig. 11).
      相似文献   

    设为首页 | 免责声明 | 关于勤云 | 加入收藏

    Copyright©北京勤云科技发展有限公司  京ICP备09084417号