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1.
The content of neuraminic acid (NA) of different developmental stages of trout eggs was determined.
相似文献
| 1. | The total NA increases from about 13 g NA per egg (6–8 weeks before spawning) to 50 g directly before spawning until hatching. |
| 2. | In freshly hatched fish larvae the NA-content is decreased to about 40 per cent as compared with stages before hatching. |
| 3. | The ratio of bound to free NA decreases from values of about 13.5 (6–8 weeks before spawning) to 0.85–1.2 at the hatching-stage. |
| 4. | The bound NA is almost entirely bound to sialo-glycoproteins. |
2.
Valentina Prado Ben A. Wender Thomas P. Seager 《The International Journal of Life Cycle Assessment》2017,22(12):2018-2029
Purpose
Identification of environmentally preferable alternatives in a comparative life cycle assessment (LCA) can be challenging in the presence of multiple incommensurate indicators. To make the problem more manageable, some LCA practitioners apply external normalization to find those indicators that contribute the most to their respective environmental impact categories. However, in some cases, these results can be entirely driven by the normalization reference, rather than the comparative performance of the alternatives. This study evaluates the influence of normalization methods on interpretation of comparative LCA to facilitate the use of LCA in decision-driven applications and inform LCA practitioners of latent systematic biases. An alternative method based on significance of mutual differences is proposed instead.Methods
This paper performs a systematic evaluation of external normalization and describes an alternative called the overlap area approach for the purpose of identifying relevant issues in a comparative LCA. The overlap area approach utilizes the probability distributions of characterized results to assess significant differences. This study evaluates the effects in three LCIA methods, through application of four comparative studies. For each application, we call attention to the category indicators highlighted by each interpretation approach.Results and discussion
External normalization in the three LCIA methods suffers from a systematic bias that emphasizes the same impact categories regardless of the application. Consequently, comparative LCA studies that employ external normalization to guide a selection may result in recommendations dominated entirely by the normalization reference and insensitive to data uncertainty. Conversely, evaluation of mutual differences via the overlap area calls attention to the impact categories with the most significant differences between alternatives. The overlap area approach does not show a systematic bias across LCA applications because it does not depend on external references and it is sensitive to changes in uncertainty. Thus, decisions based on the overlap area approach will draw attention to tradeoffs between alternatives, highlight the role of stakeholder weights, and generate assessments that are responsive to uncertainty.Conclusions
The solution to the issues of external normalization in comparative LCAs proposed in this study call for an entirely different algorithm capable of evaluating mutual differences and integrating uncertainty in the results.3.
Walter Kaiser 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1988,163(5):565-584
| 1. | The behaviour of isolated individual forager honeybees during the night has been investigated with a variety of experimental methods. Prolonged rest in these diurnal insects is accompanied by: reduced muscle tone (Figs. 1, 6, 10–12), decreased motility (Figs. 2, 3, Table 1), lowered body temperature (Figs. 7, 8) and raised reaction threshold (Fig. 9). These phenomena strongly resemble four characteristic features of sleep in humans, mammals and birds. It is thus very likely that the profound rest which forager bees experience at night is sleep. This assumption is further supported by the results of previous investigations of visual interneurones in the bee. |
| 2. | The antennae of sleeping bees manifest characteristic postural constellations (Fig. 6). High reaction thresholds are associated with particular antennal positions. |
| 3. | The total sleep time (duration of antennal immobility plus duration of small antennal movements) in 24 h for two bees was 7.6 h and 4.9 h (Table 1). |
| 4. | Bees which rest in a hive at night also display phenomena which have been encountered during the laboratory investigations. |
| 5. | Sleep in mammals is an active, controlled process; the same seems to be true of sleep in honeybees (Figs. 3, 4). Unlike mammals, bees experience their deepest sleep towards the end of the sleep phase (Figs. 3, 9, 10, 12). |
4.
S. Weiss F. Schaeffel 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1993,172(3):263-270
| 1. | If the eyes of young chickens are deprived of clear vision by translucent occluders, they develop considerable amounts of axial myopia within days. At the same time, the day time retinal dopamine levels drop by about 30%. Because the retinal dopamine levels of normally sighted chicks also differ diurnally and are low at night, we expected that the rate of axial eye growth might also differ during this time. |
| 2. | Unexpectedly, eyes grew in length only during the day (about 0.13 mm/day) and even shrank during the night (about -0.04 mm/night, average net growth + 0.09 mm in 24 h). |
| 3. | If the eyes were occluded, they grew both during the day and also at night (average net growth: + 0.16 mm in 24 h). Therefore, development of deprivation myopia was a result of the lack of growth inhibition at night rather than of excessive growth during the day when the actual deprivation occurred. |
| 4. | Suppression of dopaminergic retinal pathways by intravitreal injections of the neurotoxin 6-hydroxy-dopamine (6-OHDA) also suppressed development of deprivation myopia and it restored the growth inhibition at night. With normal visual experience, the drug had no effect on axial eye growth and refractive state. |
| 5. | Diurnal growth rhythms of the eyes disappeared under continuous light. |
| 6. | Our results show that: (a) normal diurnal eye growth rhythms require a normal (12/12 h) light cycle and normal visual experience; with a degraded retinal image during the day, growth rates at night change so that they relate to retinal dopamine levels in the opposite way as with normal visual experience, (b) intact retinal dopaminergic pathways are necessary to mediate the deprivation-induced alterations in diurnal growth rhythms and myopia, (c) deprivation myopia is not simply a result of the lack of visual feedback control of eye growth during deprivation but rather of an active process related to abnormal diurnal dopamine rhythms. |
5.
Volker Schmid Beat Schmid Barbara Schneider Robert Stidwill George Baker 《Development genes and evolution》1976,179(1):41-56
| 1. | Umbrellar fragments of the leptomedusaCampanularia johnstoni with or without parts of the radial canal demonstrate a gradient in the potential for manubrium regeneration and in regeneration time. |
| 2. | Implantation experiments exclude the manubrium as a source of inhibition or induction in the regeneration of another manubrium. One special case of inhibition appears to be due to competition for a common substrate. |
| 3. | Medusa fragments consisting of only peripheral umbrella (C-fragments) undergo a considerably different restitution process as compared with fragments including a central portion of the umbrella (A-fragments). Vital stain is seen to disperse in the subumbrellar tissues during this process in C-fragments, whereas vital stain in A-fragments is observed to accumulate and later on is incorporated into the regenerating manubrium. |
| 4. | The mesogloea of different-sized A-fragments retains a stable form when freed of its adhering cellular components, after a 12–24 h regeneration period; for C-fragments, however, the same result is not observed until 72 to 96 h after their excision. |
| 5. | InPodocoryne carnea the observed gradients in manubrium regeneration can be abolished when the subumbrellar tissues are separated from the mesogloea by collagenase treatment. |
| 6. | A model for manubrium regeneration in interradial fragments, based on the influence of tension exerted by the cicatrization process and the counteracting mesogloeal force, is presented and discussed. |
6.
U. Sch?ttler G. Schroff 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1976,108(3):243-254
| 1. | The activities of glycolytic enzymes and of related enzymes of anaerobic carbohydrate metabolism were determined inTubifex. The complete line of glycolytic enzymes was detected (Table 1). Only very little lactate dehydrogenase activity could be detected, while high activities of enzymes essential for the production of alanine and succinate are present. |
| 2. | Under anaerobic conditions, lactate, alanine, succinate and volatile fatty acids are formed from14C-labeled glucose (Tables 2 and 3). |
| 3. | Glycogen degradation was measured under anaerobic conditions (Fig. 1). |
| 4. | During anaerobiosis a significant increase of alanine, succinate, propionate and acetate was found. However, the concentration of lactate increased only slightly. After an initial increase within the first 24 h of anaerobiosis, the concentration of alanine remained constant. Succinate, on the other hand, accumulated continuously during 48 h of anaerobiosis, reaching concentrations of 150 mol/g dry weight (Table 4, Fig. 2). |
| 5. | The major end products of fermentation were identified as propionate and acetate. Both are excreted in substantial amounts (Table 5). |
| 6. | The amount of anaerobic end products equals the amount of glycogen metabolized (Table 6). |
7.
J. Robb 《Human Evolution》1994,9(3):215-229
In recent years anthropologists have made much progress in understanding ancient activities from skeletal remains. In this
paper, material from the Iron Age cemetery at Pontecagnano (VII-IV century BC) is used to illustrate activity-related traits
of eight basic categories:
These traits, and others, can be used not only singly but in conjunction to define (a) patterns of activity and occupational
specialization for individuals, and (b) distributions within society reflecting the basic division of labor by geneder and
class. 相似文献
| (1) | idiosyncratic patterns of dental wear |
| (2) | activity-related articular degeneration |
| (3) | non-pathological functional alterations (neoformations, contact facets) |
| (4) | mechanical remodelling of bone architecture |
| (5) | enthesopathies (muscular lesions) |
| (6) | traumatic lesions |
| (7) | activity-related pathologies |
| (8) | activity-related nutritional characteristics |
8.
Kenji Tomioka Kenji Yamada Shinya Yokoyama Yoshihiko Chiba 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(3):291-298
The coupling mechanism between the bilaterally paired optic lobe circadian pacemakers in the cricket Gryllus bimaculatus was investigated by recording locomotor activity, under constant light or constant red light, after the optic nerve was unilaterally severed.
These results suggest that the 2 optic lobe pacemakers weakly couple to one another and that the cricket maintains a stable temporal structure in its behavior through the phase-dependent mututal inhibition of activity and the phase-dependent freerunning period modulation. 相似文献
| 1. | The majority (about 70%) of the animals showed a locomotor rhythm with 2 rhythmic components; one freerunning with a period of 25.33 ± 0.41 (SD) h and the other with 24.36 ± 0.37 (SD) h under constant light (Fig. 3A). |
| 2. | Removal of the intact side optic lobe abolished the longer period component (Fig. 4A), while the operation on the operated side caused a reverse effect (Fig. 4B), indicating that the longer and the shorter period components are driven by the pacemaker on the intact and the operated side, respectively. |
| 3. | The activity driven by a pacemaker was inhibited during the subjective day of the contralateral pacemaker (circadian time 0–10, Fig. 5). |
| 4. | The freerunning periods of the two components were not constant but varied as a function of the mutual phase angle relationship (Figs. 3A, 7, 8). |
9.
D. S. Saunders 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1992,170(1):121-127
| 1. | Larval cultures of Sarcophaga argyrostoma, preconditioned for a low incidence of pupal diapause by embryonic exposure to continuous light, were transferred from sequences of diapause-inducing long nights into terminal sequences of either diapause-averting short nights or darkness. Conversely, other groups preconditioned for a high incidence of diapause by embryonic exposure to long nights were transferred from short nights into terminal long nights or darkness. |
| 2. | The inductive effects of long nights (diapause) and short nights (non-diapause) were accumulated during the larval sensitive period which continued until puparium formation. Since the larvae in any one group formed puparia over a number of days it follows that late pupariaters experienced a greater number of inductive light cycles (or days in DD) than those that pupariated early. |
| 3. | Analysis of diapause incidence in cultures transferred from long nights to DD at different temperatures, as a function of the day of pupariation, showed that the daily increase in diapause was a temperature-compensated process beginning after 9–10 cycles and reaching 10% after about 15 cycles. Cultures transferred from a series of short nights into DD at different temperature showed no evidence of temperature-compensation. |
| 4. | The results are interpreted in terms of the external coincidence model for photoperiodic time measurement. |
10.
Hermann Martin Herbert Korall Barbara Förster 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1989,164(4):423-431
Artificial magnetic fields (MF) influence physiological processes in bees.
Dedicated to Prof. Dr. Drs. h.c. M. Lindauer on the occasion of his 70th birthday 相似文献
| 1. | An inhomogeneous, static magnetic field (IMF) reduces the flying activity of bees and increases their life span by more than 60%. |
| 2. | The content of the ageing pigment lipofuscin in brain and, to a lesser extent, in thorax muscles increases with the physiological age. The content of lipofuscin of the thorax muscle is only 1/5 that of the brain. |
| 3. | Despite their increased chronological age (60–74%) brain lipofuscin of bees under conditions of an inhomogeneous, static magnetic field is slightly reduced compared with bees in natural earth's magnetic field (EMF) conditions. No effects could be registered in the muscle lipofuscin of the thorax. |
| 4. | There was no correlation between the content of lipofuscin and the chronological age. |
| 5. | Flying activity is also reduced by horizontal magnetic fields (0.40–1.45 Oe). |
| 6. | Dance tempo is reduced in compensated EMF and amplified static magnetic fields (0.84 Oe). Dance tempo is drastically reduced if compensation of the EMF is followed by application of a 5 Hz magnetic field with 1.04 Oepp, directed E-W. |
11.
R. V. Baudinette Karen A. Nagle R. A. D. Scott 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1976,109(2):159-168
| 1. | Rates of oxygen consumption were measured during locomotion in five species of marsupials of the family Dasyuridae. The body weights of the animals ranged between 0.15 and 1.12 kilograms. |
| 2. | The rate of change of power input with speed was generally lower than equivalent eutherian values. The extrapolation to zero speed was consistently a higher multiple of resting metabolic levels than found in eutherians. |
| 3. | The minimum cost of locomotion (M run) as a function of body mass (wt) is described by the equationM run=4.75 wt–0.34. The exponent is similar to that described for eutherians and reptiles, but the constant term is significantly lower. |
| 4. | Metabolic scope in these animals is similar over the size range used and may be greater than in eutherians. |
| 5. | Heat dissipation during locomotion has been partitioned into evaporative and non-evaporative routes. Storage of heat during locomotion was never more than fifty per cent of total production. |
12.
Victy Mercy Gerald 《Hydrobiologia》1976,49(2):103-109
| 1. | At 28°C conversion efficiency of total nitrogen (TN) was inversely related to size. |
| 2. | In the pre-adult stage protein nitrogen (PN) conversion efficiency was high whereas in the Post-adult stage non-protein nitrogen (NPN) conversion efficiency was high. |
| 3. | Lower temperature (20°C) was not congenial for PN conversion. |
| 4. | Higher temperature favoured PN conversion for smaller fish but NPN for larger fish. |
13.
Impact of phosphorus supply on root exudation, aerenchyma formation and methane emission of rice plants 总被引：2，自引：0，他引：2
This study evaluated the impact of P supply on rice plant development and the methane budget of rice fields by 2 different approaches: (1) root growth, exudation and aerenchyma formation were recorded in an experiment with hydroponic solution; (2) dissolved CH4 concentration and CH4 emission were investigated in a pot experiment. In both approaches, we used three different cultivars and three levels of P supply. In the experiment with solution culture (0.5 ppm, 5 ppm, and 10 ppm P), root exudation ranged between 0.5 to 36.7 mol C plant–1 h–1 and increased steadily with plant growth at given P level. Low P supply resulted in
However, root exudation did not differ among treatments when related to the dry weight of roots. Thus, high exudation rates were caused by larger root biomass and not by higher activity of the root tissue.The pot experiment was conducted with a P-deficient soil that was either left without amendment or fertilized by 25 and 50 mg P kg
soil
–1
, respectively. Low P supply resulted in
相似文献
| • | depressed shoot growth but increased root growth in culture solution |
| • | increments in the root/shoot ratio by factors of 1.4 to 1.9 at flowering stage |
| • | enhanced the development of root aerenchyma, and |
| • | stimulation of root exudation per plant by factors of 1.3–1.8 as compared to medium P |
| • | supply and by factors of 2.1–2.4 as compared to high P supply. |
| • | higher CH4 concentrations in soil solution; i.e., at flowering stage the soil solution concentrations were 34–50 M under P deficiency and 10–22 M under ample P supply and · significant increases of CH4 emission rates during the later stages of plant growth. |
| • | These findings reflect a chain of response mechanisms to P stress, that ultimately lead to higher methane emission rates. |
14.
This paper reviews research results on food competition between a freshwater fish community and a breeding Tufted duck population. After the experimental removal of fish from the Main Lake, the following effects were observed:
相似文献
| (1) | 1. Invertebrate (chironomid and gastropod) food for ducklings and adult Tufted ducks increased substantially. |
| (2) | 2. Tufted duckling brood use of the lake increased greatly and Tufted duckling survival appears to have increased. |
| (3) | 3. Shoveler and Pochard nested successfully for the first time. |
| (4) | 4. Submerged aquatic macrophytes grew profusely over the lake bed for the first time leading directly to large increases in use of the Lake by wintering herbivorous waterfowl. |
| (5) | 5. When fish were re-introduced to the Main Lake sampling bay the increases in invertebrate abundance and, to a less marked extent, macrophyte abundance were reversed. |
15.