Age-dependent changes of the autonomic neurons expressing vanilloid TRPV1 receptors

Expression of vanilloid receptors in sympathetic and afferent ganglionic neurons was studied in rats of different ages (newborn, 10-day old, 20-day old, 30-day old, 60-, 180-day old) using immunohistochemical methods. The results obtained indicate that the majority of the afferent neurons in the nodose ganglion of vagus nerve (GNVN) and in the spinal ganglia (SG) were TRPV1-positive from birth onwards. The percentage of neurons containing TRPVT receptors in SG slightly increased with age up to 30 days postnatally. In the GNVN, the percentage of TRPV1-positive neurons was higher in comparison with the SG in all age groups. The vast majority of the sympathetic neurons were TRPV1-positive from birth onwards, and the percentage of TRPV1-immunoreactive neurons substantially decreased during further development. In 20-day old and older animals, we observed only few TRPV1-immunoreactive neurons in sympathetic ganglia. Finally, the percentage of neurons containing these types of neurons, become similar to adult animals to the end of the first month of life.     

Effect of age on reproductive attributes of an aphidophagous ladybird, Cheilomenes sexmaculata

The effect of both male and female age was investigated on certain reproductive attributes, viz. mating incidence, mating duration, fecundity, percent egg viability, ratio of reproductive and non‐reproductive periods and reproductive rate, of an aphidophagous ladybird, Cheilomenes sexmaculata (Fabricius). Females started mating at the age of 8 hours post‐emergence (PE) and males at the age of 2 days PE. Mating in the laboratory was a male‐dominated phenomenon. The mating duration and reproductive rate of 10‐day‐old females when mated with males of varying ages increased up to the male age of 60 days, and thereafter decreased, whereas, fecundity, egg viability and ratio of reproductive and non‐reproductive periods increased up to the male age of 50 days, and thereafter declined. However, when females of varying ages were mated with 10‐day‐old males, fecundity and reproductive rate increased up to 40 days of female age, respectively, then decreased. The ratio of reproductive and non‐reproductive periods increased with increasing age of females. Mating age for optimal reproductive output was 10J50‐day‐old males and NE to 40‐day‐old females. Reproductive cessation in males was recorded after 50 days PE, whereas in females at the age of 40 days PE. Higher mating durations lead to elevated reproductive rates. Delay in the reproductive phase was positively correlated with longevity. The results of this study may aid mass multiplication of this ladybird by identifying and promoting usage of adults of optimal age. Our results also enhance our understanding of the effect of age on reproductive attributes in ladybirds.     

米蛾卵繁育的螟黄赤眼蜂的适宜冷贮温度和虫龄

为了全面评价冷贮对米蛾Corcyra cephalonica Stainton卵繁育螟黄赤眼蜂Trichogramma chilonis Ishii的影响, 本试验采用米蛾卵为寄主, 以冷贮温度（3和10℃）、 冷贮虫龄（以接蜂开始时间为起点, 接蜂后1, 2, 3, 4, 5, 6, 7, 8和9日龄）和冷贮时间（1, 2, 3和4周）为试验因子, 研究了冷贮对螟黄赤眼蜂活蛹率、 羽化率和畸形率的影响。结果表明： 3个因素均能单独或互作显著影响活蛹率、 羽化率和畸形率（P＜0.05）。综合各冷贮虫龄对低温的反应, 螟黄赤眼蜂对3℃较敏感, 此温度下1-3日龄的活蛹率和各虫龄的羽化率均显著下降（P＜0.05）, 不适宜长期冷贮; 10℃下各虫龄的活蛹率受冷贮时间的影响不显著, 1-3日龄的羽化率受冷贮时间的影响也不显著, 冷贮4周后仍有74%以上的羽化率, 10℃适宜冷贮。不同冷贮温度下冷贮适宜虫龄不同。在10℃下, 最适冷贮虫龄是3日龄的赤眼蜂, 此虫龄不同冷贮时间的活蛹率（74.09%～77.59%）和羽化率（74.26%～90.37%）均与对照无显著差异（P>0.05）, 但显著高于其他虫龄（P＜0.05）。此虫龄在10℃下冷贮1~3周, 畸形率在27%以内。结果表明米蛾卵内螟黄赤眼蜂不同冷贮温度下适宜冷贮虫龄不同。     

Activity of nuclear RNA polymerases in the liver of rats of different ages after phenobarbital administration

DNA-dependent RNA-polymerases of nuclei isolated from the liver of rats aged 3- and 24 months were studied in different periods after phenobarbital administration. It is shown that 4h after single intraperitoneal injection of the preparation (80 mg per 1 kg of the body mass) to young animals the activity of the RNA-polymerase I rises, it remains higher, the following 12-20 h and then returns to the initial level. The activity of RNA-polymerases II and III under these conditions 16 h later remains higher the following 8 h and 24 h later the activity of the first enzyme returns to the initial value and that of the second one becomes still more. In old rats (24 months) the activity of all three classes of RNA-polymerases is lower than in young ones and increases only 48 h later. Under long-term administration of phenobarbital (40 mg per 1 kg of the body mass daily, 4 days) the activity of RNA-polymerase I was the same as in the intact animals of the corresponding ages and the activity of RNA-polymerases II and III increased both in young and old rats. Single administration of the preparation increases the liver mass in the young animals 24 h later and in the old ones--48 h later. Long-term administration of the preparation enhances its mass both in young and old animals, but its relative increase is more expressed in rats at the age of 3 months.     

Features of the circadian rhythm of skin temperature in eight- to nine-year-old children and young adults

The age-related features of the circadian rhythm of skin temperature were studied using the Termochron iButton method in two age groups of subjects: eight-to nine-year-old boys and girls and young men and women aged 20–22 years. For this purpose, the temperature was monitored for 48 h at a recording interval of 10 min. The following authentic chronobiological differences were revealed: the temperature mesor was higher in the girls than in the boys and in the young men it was higher than in the young women. The circadian rhythm’s amplitude was higher in the boys and the young women. Studies of the chronological values in different 24-h periods showed that the average level of temperature at night was lower in all subjects. The amplitude in the adults did not differ in different 24-h periods, whereas it was higher in the children at night.     

Production of ethanol by alginate-entrapped Saccharomyces cerevisiae strain "14-12"

Cells of S. cerevisiae strain "14-12" of different ages were immobilized in sodium alginate and used for conversion of glucose to ethanol. Immobilized cells of 48 hr old were the most potential. Employment of high counts of alginate-entrapped cells shortened the period required for production of the maximal alcohol yield. However, the percentage surviving cells decreased with increasing initial cell counts. Maximal accumulation of ethanol (4.18 g/100 ml) was obtained after 4 days of static fermentation with 1.8 X 10(8) immobilized yeast cells. The residual viable cell count was found to represent 3-fold the surviving percentage in a control experiment using an inoculum of the free yeast cells. Immobilized yeast cells could convert about 85% of the available sugars to ethanol over 28 days of the repeated-batch fermentation. The immobilized cells retained 50% of their viability for 16 days. After 48 days of repeated fermentation only 6% of the yeast cells were viable, and on the 52nd day no viable cells could be detected.     

Changes in the estrous cycle and number of ovulated and fertilized ova in aging female IVCS mice

IV CS mice (ddN origin) aged 90 days (control) and 180, 210, 240, 270, 300, 330, 360 and 420 days were used for observation of the length of the estrous cycle, and the numbers of ovulated and fertilized ova. The estrous cycle between the ages of 90 and 330 days presented a regular 4-day pattern. Thereafter, regularity of the cycle declined steadily between the ages of 360 and 420 days. All mice over 420 days old exhibited cessation of cyclicity and ultimately persistent diestrus. The average number of ova ovulated in mice aged between 90 and 240 days was consistent (11.8 to 11.4 ova), whereas a steady decline was observed for mice between 270 days old (10.5 ova) and 360 days old (4.8 ova). Ova were not recovered from oviducts of mice aged about 420 days. The average number of fertilized ova (2-cell stage) in mice between 90 and 210 days old showed no significant change (11.5 to 10.3), whereas the number began to decrease in mice aged between 240 days (8.7 fertilized ova) and 330 days (2.5 fertilized ova). No fertilized ova were recovered from the oviducts of mice around 360 days old. These findings demonstrate that the decline of reproductive activity is initially observed in the number of fertilized ova, followed by a decline in the number of ovulations and finally by loss of the estrous cycle.     

Tolerance of young allis shad Alosa alosa (Clupeidae) to oxy-thermic stress

The ecology of the young stages of allis shad Alosa alosa is poorly documented, although they can be exposed to many pressures during their freshwater phase and their downstream migration. When passing through systems such as the Gironde-Garonne-Dordogne watershed (GGD, SW France), they can be subjected to high temperatures and low levels of oxygen (hypoxia). The aim of this work is to assess the tolerance of young Alosa alosa at four ages (c. 10, 30, 60 and 85 days old) by challenging them to different temperatures (18, 22, 26 and 28°C) together with decreasing oxygen saturation levels (from 100% to 30%). Survival of the 10-day-old individuals was not influenced by oxy-thermic conditions, but high stress levels were detected and perhaps this age class was too fragile regarding the constraint of the experimental design. Survival at 30 and at 60 days old was negatively influenced by the highest temperatures tested alone (from 26°C and from 28°C, respectively) but no effect was detected at 85 days old up to 28°C. A combined effect of temperature and oxygen level was highlighted, with heat accelerating survival decrease when associated with oxygen level depletion: essentially, survival was critical (<50%) at 30 days old at temperature ≥22°C together with 30% O₂; at 60 days old, at temperature = 28°C with 30% O₂; at 85 days old, at temperature ≥26°C with ≤40% O₂. Tolerance to oxy-thermic pressures appeared to be greater among the migratory ages (60 and 85 days old) than among the 30-day-old group. Based on environmental data recorded in the GGD system and on our experimental results, an exploratory analysis allowed a discussion of the possible impact of past oxy-thermic conditions on the local population dynamics between 2005 and 2018. The oxy-thermic conditions that may affect Alosa alosa at ages when they migrate downstream (60 and 85 days old) were not frequently recorded in this period, except in cases of extreme episodes of heat together with hypoxia that occurred in some years, in summertime in the turbidity maximum zone of the Gironde estuary (particularly in the year 2006). Interestingly, oxy-thermic conditions that are likely to threaten the 30-day-old individuals occurred more frequently in the lower freshwater parts of the GGD system between the years 2005 and 2018. In the context of climate change, a general increase in temperature is predicted, as well as more frequent and severe hypoxic events, therefore we suggest that local Alosa alosa population recruitment could encounter critical oxy-thermic conditions more frequently in the future if no adaptive management of water resources occurs.     

The effect of age on the structure and composition of rat tendon fibrocartilage

Biochemical and morphological aspects of fibrocartilages of calcaneal and deep digital flexor tendons in rats aged 30, 180 and 730 days were analyzed. In both tendons a stronger staining with Alcian blue, indicating the presence of proteoglycans, was detected in rats of 30 and 180 days. In animals 730 days old, it was restricted to the pericellular area. Ultrastructural analysis showed a more prominent pericellular matrix in calcaneal tendon compared to the deep digital flexor tendon. The biochemical analysis showed higher levels of proteins and glycosaminoglycans in the calcaneal tendon of 30-day-old rats compared to older rats. In the deep digital flexor tendon, no significant differences were observed between ages. The small proteoglycan, fibromodulin, was detected in both tendons of all ages, but in young rats it appeared to be running as a 210 kDa component, probably due to the association with collagen chains or self-association.     

渭北塬区不同龄苹果园土壤微生物空间分布特征

以渭北塬区塬面5、10、15和20龄苹果园为对象,距树干1.0、1.5、2.0 m处用土钻法分层采集0—30 cm土样,稀释平板法测定土壤微生物数量,平行测定土壤有机碳、总氮和总磷,分析不同龄果园土壤微生物的空间分布状况及其与土壤碳、氮、磷的关系。结果表明:土壤真菌数量随树龄增大而增加,龄间差异显著(P0.05);与对照农田相比,各龄果园放线菌数量及5龄和20龄果园细菌数量偏低,10龄和15龄果园细菌数量偏高;各龄果园土壤真菌、细菌和放线菌数量均随深度增加而减小。就相同深度土层而言,真菌数量随果园年限增大而增加,细菌则以10龄和15龄果园较多,同深度土层的放线菌龄间差异随深度增加而减小。在沿树干向外的径向水平方向上,真菌数量随果园年限的增加相应增多;10龄和15龄果园土壤细菌和放线菌高于5龄果园和20龄果园。5龄果园土壤总氮有沿树干向外、沿表层向下逐步降低的趋势,果园从5龄经10龄到15龄,其"高氮点"则逐步向外、向下移动。塬区果园土壤C∶N比偏低。     

Effects of growth medium, electrical stimulation and paralysis on various enzyme activities in cultured rat muscle cells. Comparison with activities in rat muscles in vivo.

1. Replacement of fetal calf serum and chicken embryo extract by Ultroser G and rat brain extract during the proliferation phase resulted in a higher maturation grade of cultured rat muscle cells after 7 days of differentiation, on base of the percentage of the muscle specific isoenzyme of creatine kinase (CK-MM). 2. Furthermore, the activities of creatine kinase, citrate synthase, cytochrome c oxidase and hexokinase were significantly higher. 3. Compared to the enzyme activities in m. quadriceps of 10 day-old rat and m. quadriceps, m. soleus and m. extensor digitorum longus of young adult rats, the metabolic capacity of cultured myotubes most closely resembles that of the first muscle. 4. Paralysis with tetrodotoxin caused a slight decrease of the creatine kinase activity and the percentage of CK-MM of cultured myotubes and an increase of the activities of hexokinase, phosphorylase and AMP deaminase. 5. Electrical stimulation performed at different frequencies and time periods had no effect on the enzyme activities of cultured rat muscle cells. 6. Only the AMP deaminase activity was decreased after intense electrical stimulation.     

A temperature effect on nondisjunction of the X chromosomes among eggs from agedDrosophila females

The effects of temperature and aging on the frequency of nondisjunction inDrosophila melanogaster eggs were investigated. At 25°C offspring arising from 3–5 day old control females had a nondisjunction frequency (0.943/1000 offspring) very similar to that for females who were 24–26 or 27 days old when eggs were collected (1.044/1000 offspring). When females were aged for the same length of time at 10°C the frequency of nondisjunctional exceptions increased to 3.368 per 1000 offspring. These results indicate that aging the females at 25°C does not increase the nondisjunction rate over that obtained from non-aged females raised at 25°. The increase in nondisjunction frequencies when the females were aged at 10°C reflects an influence of temperature on the meiotic process inDrosophila melanogaster. At the low temperature eggs were also aged since few or no eggs were laid during the aging process. Thus in addition to a temperature effect on nondisjunction rates at 10°C there may also be an age effect.     

Cold-induced paralysis and recovery of lung respiration and heart contractions in newborn rats (inversion of Arrhenius law for physiological functions)

Arrest of respiration and heart activity in new-born rats aged 3-4 days and 10-11 days was shown to occur at a body temperature 6-7 degrees C and 2-3 degrees C lower than in adult rats, resp. At room temperature the body temperature of profoundly cooled rat's litter gradually increases and the functions are restored. In 3-4-day old rats, at the body temperature rising from profound cooling to 15-18 degrees C, the respiration and heart rates are 2-4-fold more than at the same temperature attained from the normal body temperature. These differences in the respiration and heart rates at the same body temperature suggest an inversion of the Arrhenius law (the Q10 coefficient) for physiological functions in early ontogenesis. This effect completely disappears in 10-11-day old rats.     

Effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Lepidoptera: Noctuidae)

The ability to store different insect stadia for prolonged periods provides considerable flexibility and ability to conduct experiments properly. Therefore, studies were undertaken to determine the effect of storage temperature and duration on viability of eggs of Helicoverpa armigera (Hübner). The percentage egg hatch and incubation period were significantly (P=0.01) influenced by egg age, storage temperature, and storage duration. Egg hatch ranged from 0.0 to 96.8% across temperatures and storage durations. None of the eggs hatched when stored at -20 and 0 degrees C. The regression model with the optimum Mallow Cp statistic for any of the identified linear and quadratic terms did not improve the precision of prediction in egg hatch beyond 67.0%. Forecasting of incubation period based on egg age, storage duration, and durationxtemperature was quite effective (R2=84.2%). Day degrees required for egg hatching decreased with an increase in temperature from 10 to 27 degrees C, and egg age from 0 to 3 days. The day degree requirements were highest for 0-day-old eggs at 10 degrees C, and lowest at 27 degrees C. Although the incubation period was higher, the hatchability was lower for 0- and 1-day-old eggs stored at constant 10 degrees C, these eggs can be stored for 10 days at 10 degrees C, with a hatchability of >75.0%. It was safer to store the H. armigera eggs for 10 days at 10 degrees C, which will hatch within 1.6 to 2.0 days after restoration at 27 degrees C with a hatchability of >75.0%. This information will be useful in planning and execution of experiments involving H. armigera on various aspects of research in entomology.     

人工饲养条件下马来熊(Helarctos malayanus)生长发育和行为特点的初步研究

1987年9月至1989年8月,笔者对来自云南瑞丽的2只雄性马来熊成体和7只幼体(3♂,4♀♀)在人工饲养条件下进行了观察研究,本文报道在不同生长时期的不同饲料配方、幼熊感觉器官的发育、齿式的形成、外部形态的变化、体重的生长方法及行为。     

Histological and histochemical characteristics of the bovine notochord.

In 20 bovine embryos and fetuses 6-65 mm long (crown-rump length) and 23 to 60-70 days old, the structure and localization of acid and neutral mucopolysaccharides and glycogen in their notochord were investigated. Also, the localization in the notochord was examined of the activity of alkaline and acid phosphatases, alpha-glycerophosphate-, glucose-6-phosphate-, isocitrate-, glutamate-, lactate- and succinic- dehydrogenases, and nicotinamide-adenine-dinucleotide- and nicotinamide-adenine-dinucleotide-phosphate- diaphorases. It was found that the bovine notochord begins decomposing at the end of embryonal and the beginning of fetal development (45-50 days old) and that in the fetus aged 55-65 days it no longer represents an unbroken cord of notochordal cells. Secretory activity of notochordal cells which produce the notochordal sheath starts very early (in 10 mm-long embryos), and interruptedly increases up to the end of the embryonal developmental period when regression appears at the beginning of the fetal period. These findings agree with findings in the human embryo where, however, they relate to earlier developmental periods.     

Pre- and post-implantation losses of embryos in aging female IVCS mice

Mated female mice of the IVCS strain, aged 90 (control group), 180, 210, 240, 270, 300, 330, 360 and 420 days old, were studied for pre- and post-implantation loss of embryos. The percentage of pre-implantation loss in mice aged 90 to 210 days was 1.7/11.8 (14.4%) to 2.7/11.7 (23.1%). In mice aged 240 to 300 days it increased significantly as compared to the controls (46.5-90.2% versus 14.4%). It reached 100% in 300-days-old mice. The post-implantation loss of embryos and/or fetuses in mice aged 90 to 240 days was 1.0/10.2 (9.8%) to 2.5/9.0 (27.8%). In mice aged 270 to 300 days it increased significantly compared to the controls (100% versus 9.8%). The decrease in reproductive activity appeared first in a decrease in litter size, followed by a decrease in the number of blastocyst and implantation sites, and finally by anovulation during the process of aging in IVCS mice.     

Carbonic Anhydrase, 5''-Nucleotidase, and 2'',3''-Cyclic Nucleotide-3''-Phosphodiesterase Activities in Oligodendrocytes, Astrocytes, and Neurons Isolated from the Brains of Developing Rats

The activities of three myelin-associated enzymes, carbonic anhydrase, 5'-nucleotidase, and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNP), were measured in oligodendrocytes, neurons, and astrocytes isolated from the brain of rats 10, 20, 60, and 120 days old. The carbonic anhydrase specific activity in oligodendrocytes was three- to fivefold higher than that in brain homogenates at each age, and, at all the ages, low activities of this enzyme were measured in neurons and astrocytes. The oligodendrocytes and astrocytes from the brains of rats at all ages had higher activities of the membrane-bound enzyme 5'-nucleotidase than was observed in neurons. In oligodendrocytes from 10- and 20-day-old rats, the 5'-nucleotidase activity was two-to threefold the activity in the homogenates (i.e., relative specific activity = 2.0-3.0), and the relative specific activity of this enzyme in the oligodendrocytes declined to less than 1.0 at the later ages, concomitant with the accumulation of 5'-nucleotidase in myelin. The CNP activity was always higher in oligodendrocytes than in neurons, but not appreciably different from that in astrocytes from 20 days of age onward. The relative specific activity of CNP was highest in the oligodendrocytes from 10-day-old rats but was lower, at all ages, than we had observed in bovine oligodendrocytes. These enzyme activities in oligodendroglia are quite different in amount and developmental pattern from those reported previously for myelin.     

Susceptibility dynamics in neonatal BALB/c mice infected with Cryptosporidium parvum.

BALB/c Mice were infected as neonates and at different ages to study the susceptibility dynamics in this animal model to Cryptosporidium parvum. When 4-day-old animals were infected with 10(5) C. parvum oocysts, parasites were detected in the terminal ileum when the mice became 14-25 days old (10-21 days post-infection [PI]). The percentage of animals positive for parasites was 100% up to the age of 19 days (15 days PI) but decreased immediately thereafter until no parasites were detected in 26-day-old (22 days PI) or older mice. Parasite load also decreased in these animals from 184.7 parasites per high power field in 14-day-old animals (10 days PI) to 0.22 in 25-day-old (21 days PI) mice. In a second study, some neonatal mice became resistant to C. parvum when infection was attempted at day-10 of age (day-15 of age at sacrifice). The susceptibility to C. parvum decreased until 14 days of age (19 days of age at sacrifice) when mice could no longer be infected. Parasite load also decreased in infected mice from 235.6 parasites per high power field (9 days of age at sacrifice) to 0.25 (18 days of age at sacrifice).     

Bioclimate and growth history affect beech lifespan in the Italian Alps and Apennines

When site factors reduce growth rates, tree lifespan tends to increase. This study investigates processes leading to such inverse relationship in Fagus sylvatica stands distributed along two elevation gradients, with an emphasis on climatic response, suppression periods, and growth trends. Dendrochronological records from old‐growth beech populations sampled at different elevations within two different bioclimatic regions (Alps vs. Apennines), were used to investigate factors that control tree lifespan. Differences between old‐growth (12) and nearby managed (15) stands were used to assess effects of silvicultural practices on maximum age. Logging reduced tree lifespan not only by removing older trees, but also by reducing the number of years beech individuals spent in the shaded understory. Tree lifespan and growth rates were affected by climate (spring–summer temperature) and were inversely related to one another along elevation gradients. The greatest lifespan was observed in old‐growth high‐mountain populations, and was related not only to slower growth due to a shorter growing season, but also to multidecadal periods of growth suppression during the initial development stages in the understory (i.e., slower growth rates at the youngest cambial ages). Past unfavorable climatic periods (in this case, the Little Ice Age) also helped increase tree lifespan. Using a linear model, we estimated a reduction in beech lifespan of 23 ± 5 years for each degree of warming. Basal area increment of trees with the maximum observed lifespan showed an increasing trend over time. Because growth of old (>300 years) trees has increased in the Alps, while it has recently declined in the Apennines, different bioclimatic regions can have opposite responses to global climatic change. In the next decades, if warming continues, beech lifespan could be reduced in the Alps by faster growth and in the Apennines by drought‐induced mortality.