The Capacity of Various Detergents to Solubilize and Stabilize Protochlorophyll(ide) Holochrome

Earlier work has shown that protochlorophyll(ide) holochrome is associated with the prolamellar body membranes in etioplasts of barley (Hordeum vulgare L.), and that this pigment-protein complex can be extracted in a stable, photoactive form by the use of saponin. For future work it would be advantageous if saponin, a detergent mixture, could be replaced by a single, well-characterized substance. The spectral characteristics of holochrome extracted with 10 ionic and nonionic detergents were compared to those of the holochrome extracted with saponin. Mulgofen BC-840 and digitonin extracted significant amounts of photoactive protochlorophyll(ide) holochrome, but this activity was highly labile, and no adequate substitute for saponin was found. Thus the stabilizing and solubilizing function of saponin is not simply related to the general properties of detergents.     

Equilibrium between Genetic Drift and Migration at Various Mutation Rates: Simulation Analysis

Rates of approach to equilibrium values of F _ST /R _ST at various mutation rates and using different mutation models (K-allele model KAM and stepwise model SMM) were analyzed numerically for the finite island model and the one-dimensional stepping stone models of migration, using simulation. In the island model of migration and the KAM mutation model, the rate of approach to the equilibrium F _ST value was appreciably higher and the equilibrium value was almost twofold lower at μ (mutation rate) = m (migration rate) than at μ ≪ m. In the one-dimensional stepping stone model of migration and the KAM model of mutation, the mutation rate significantly affected both the rate of approaching F _ST equilibrium and the equilibrium value. In both island and one-dimensional stepping stone models and SMM, R _ST was not influenced by various mutation rates. The rate of approach to the equilibrium values of both F _ST and R _ST was lower for the stepping stone model than to the island model. R _ST was rather resistant to deviations from the SMM mutation model. __________ Translated from Genetika, Vol. 41, No. 9, 2005, pp. 1283–1288. Original Russian Text Copyright ? 2005 by Efremov.     

Breathing strategy of the adult horse (Equus caballus) at rest

To investigate the mechanism underlying the polyphasic airflow pattern of the equine species, we recorded airflow, tidal volum, rib cage and abdominal motion, and the sequence of activation of the diaphragm, intercostal, and abdominal muscles during quiet breathing in nine adult horses standing at rest. In addition, esophageal, abdominal, and transdiaphragmatic pressures were simultaneously recorded using balloon-tipped catheters. Analysis of tidal flow-volume loops showed that, unlike humans, the horse at rest breathes around, rather than from, the relaxed volume of the respiratory system (Vrx). Analysis of the pattern of electromyographic activities and changes in generated pressures during the breathing cycle indicate that the first part of expiration is passive, as in humans, with deflation toward Vrx, but subsequent abdominal activity is responsible for a second phase of expiration: active deflation to below Vrx. From this end-expiratory volume, passive inflation occurs toward Vrx, followed by a second phase of inspiration: active inflation to above Vrx, brought about by inspiratory muscle contraction. Under these conditions the abdominal muscles appear to share the principal pumping duties with the diaphragm. Adoption of this breathing strategy by the horse may relate to its peculiar thoracoabdominal anatomic arrangement and to its very low passive chest wall compliance. We conclude that there is a passive and active phase to both inspiration and expiration due to the coordinated action of the respiratory pump muscles responsible for the resting adult horse's biphasic inspiratory and expiratory airflow pattern. This unique breathing pattern perhaps represents a strategy of minimizing the high elastic work of breathing in this species, at least at resting breathing frequencies.     

Intraspecific Scaling of the Resting and Maximum Metabolic Rates of the Crucian Carp (Carassius auratus)

The question of how the scaling of metabolic rate with body mass (M) is achieved in animals is unresolved. Here, we tested the cell metabolism hypothesis and the organ size hypothesis by assessing the mass scaling of the resting metabolic rate (RMR), maximum metabolic rate (MMR), erythrocyte size, and the masses of metabolically active organs in the crucian carp (Carassius auratus). The M of the crucian carp ranged from 4.5 to 323.9 g, representing an approximately 72-fold difference. The RMR and MMR increased with M according to the allometric equations RMR = 0.212M ^0.776 and MMR = 0.753M ^0.785. The scaling exponents for RMR (b _r) and MMR (b _m) obtained in crucian carp were close to each other. Thus, the factorial aerobic scope remained almost constant with increasing M. Although erythrocyte size was negatively correlated with both mass-specific RMR and absolute RMR adjusted to M, it and all other hematological parameters showed no significant relationship with M. These data demonstrate that the cell metabolism hypothesis does not describe metabolic scaling in the crucian carp, suggesting that erythrocyte size may not represent the general size of other cell types in this fish and the metabolic activity of cells may decrease as fish grows. The mass scaling exponents of active organs was lower than 1 while that of inactive organs was greater than 1, which suggests that the mass scaling of the RMR can be partly due to variance in the proportion of active/inactive organs in crucian carp. Furthermore, our results provide additional evidence supporting the correlation between locomotor capacity and metabolic scaling.     

毛决明种子不同发育时期发芽力和脱水耐性的初步研究

毛决明种子发芽力在花后39d后逐渐上升,发芽率和发芽指数在花后53d,活力指数在花的67d最大值,而后有所降低,花后39-74d,含水量逐渐下降,但下降速度不等,花后67d种子干重达到最大值,花后67-74d含水量显著下降,花后39-74d,含水量逐渐下降,但下降速度不等,花后67d种子干重达到最大值,花后67-74d含水量显著下降。种子存在明显的成熟脱水阶段。种子的脱水耐性在花后46-60d逐渐增强,60d达到最大值,后有所下降,轻微脱水可显著提高花后46d和67d的种子的发芽率,花后60-67d的种子能忍耐10%含水量,毛决明种子极可能是正常性种子。     

Reliability and Determinants of Self-Evaluation of Breathing Questionnaire (SEBQ) Score: A Symptoms-Based Measure of Dysfunctional Breathing

Dysfunctional breathing is characterised by an abnormal breathing pattern leading to respiratory symptoms. The 25-item Self Evaluation of Breathing Questionnaire (SEBQ) has been developed to measure breathing-related symptoms and their severity but lacks thorough evaluation. To determine reproducibility, internal consistency and predictors of SEBQ score, 180 participants completed an online SEBQ with additional demographic and lifestyle questions. Two weeks later, 155 of those repeated SEBQ. Test–retest correlation of the SEBQ was high [intraclass correlation coefficient (3, 1) = 0.89; 95 % CI 0.85–0.92]. There was no difference in SEBQ score between test and retest (15.1 (11.6) [mean (SD)] versus 14.7 (12.4); P = 0.4) and the score showed a typical error (standard error of measurement) of 4.0. Internal consistency was high (Cronbach’s α = 0.93), and a single factor structure for items was shown. Smoking status, reported respiratory disease, recent respiratory illness and female gender were positively-associated predictors of SEBQ score, and together explained 25.6 % of score variance (P ≤ 0.001). The SEBQ has high test–retest reproducibility and its score may be predicted by current smoking, chronic respiratory disease, recent respiratory illness and female gender, thus may be a useful clinical screening tool for dysfunctional breathing.     

不同条件下鲤鱼鳃部对高岭土颗粒吸附态铜的吸收

在水相溶解态铜浓度和高岭土吸附态铜浓度保持不变,pH和高岭土粒径不同条件下,研究了鲤鱼鱼鳃对铜的吸收。结果表明在本研究范围内,吸附态铜的存在增加了鱼鳃吸收。鳃对铜的吸收随pH增加而递增,随高岭土粒径减少而递增。利用MINTEQA2软件分析了不同实验条件下鱼鳃微环境中铜的形态分布特征,对吸附态铜可能的生物有效性机制进行了说明。     

Vitrification of Mouse Embryos at Various Stages by Open-Pulled Straw (OPS) Method

This study was performed to pursue the optimal condition for the cryopreservation of mouse morulae by a two-step OPS method and to investigate the feasibility of the optimal condition for vitrification of embryos at other developmental stages. First, the mouse morulae were vitrified in OPS using one-step procedure—that is, embryos were vitrified after direct exposure to EDFS30 (15% ethylene glycol (EG), 15% dimethyl sulfoxide (DMSO), Ficoll and sucrose), or two-step method—that is, embryos were first pretreated in 10%E+10%D (10% EG and 10% DMSO in mPBS) for 30 sec, then exposed to EDFS30 for 15 to 60 sec, respectively. After vitrification and warming, the embryos were morphologically evaluated and assessed by their development to blastocysts, expanded/hatched blastocysts, or to term after transfer. The result showed that all the vitrified-warmed morulae had similar blastocyst rate compared to that of control (91.7% vs. 100%), and the highest developmental rate to expanded blastocysts (100%) or hatched blastocysts (62.3%) was observed when the morulae were pretreated with 10%E+10%D for 0.5 min, exposed to EDFS30 for 25 sec before vitrification and warming in 0.5 M sucrose for 5 min. After transfer, the survival rate (33.1%) in vivo of the vitrified morulae was higher (P > 0.05) than that of the fresh embryos (24.6%). Secondly, embryos at different stages were cryopreserved and thawed following the above program. Most (93.4 to 100%) of the embryos recovered after vitrification were morphologically normal at all the developmental stages. The blastocyst rates of the vitrified one-cell (52.5 to 66.7%) and the two-cell (63.3 to 68.9%) embryos were lower (P < 0.05) than those of the vitrified four-cell embryos (81.7 to 86.4%), the eight-cell embryos (90.0 to 93.3%), morulae (96.7 to 100%), and the expanded blastocysts rate (98.3 to 100.0%) of the vitrified early blastocysts. The highest survival rate in vivo of vitrified embryos were from the early blastocysts (40.4%), which was similar to that of fresh embryos (48.6%). The data demonstrate that the optimal protocol for the cryopreservation of morulae was suitable for the four-cell embryos to early blastocyst stages and that the early blastocyst stage is the most feasible stage for mouse embryo cryopreservation under our experimental conditions.     

CO2 and Water Vapor Exchange across Leaf Cuticle (Epidermis) at Various Water Potentials

Cuticular properties affect the gas exchange of leaves, but little is known about how much CO2 and water vapor cross the cuticular barrier or whether low water potentials affect the process. Therefore, we measured the cuticular conductances for CO2 and water vapor in grape (Vitis vinifera L.) leaves having various water potentials. The lower leaf surface was sealed to force all gas exchange through the upper surface, which was stoma-free. In this condition both gases passed through the cuticle, and the CO2 conductance could be directly determined from the internal mole fraction of CO2 near the compensation point, the external mole fraction of CO2, and the CO2 flux. The cuticle allowed small amounts of CO2 and water vapor to pass through, indicating that gas exchange occurs in grape leaves no matter how tightly the stomata are closed. However, the CO2 conductance was only 5.7% of that for water vapor. This discrimination against CO2 markedly affected calculations of the mole fraction of CO2 in leaves as stomatal apertures decreased. When the leaf dehydrated, the cuticular conductance to water vapor decreased, and transpiration and assimilation diminished. This dehydration effect was largest when turgor decreased, which suggests that cuticular gas exchange may have been influenced by epidermal stretching.     

Maximum diving depths of northern rockhopper penguins (Eudyptes chrysocome moseleyi) at Amsterdam Island

 The mean maximum dive depth from 49 foraging bouts by northern rockhopper penguins, measured using capillary-tube depth gauges, was 66±4 m (12–168 m). There were no differences in the maximum dive depths between male and female penguins. Northern rockhopper penguins dived deeper in early than in late creche stages (83±7 vs 57±4 m), and this was associated with probable dietary changes, squid dominating the diet by mass (44%) in November, and fish (64%) in December 1994 at Amsterdam Island. Received: 10 January 1996/Accepted: 31 March 1996     

Breathing synchrony in franciscana (Pontoporia blainvillei) and Guiana dolphins (Sotalia guianensis) in Southern Brazil

Synchronous breathing may be a useful proxy for studying other, and perhaps more complex, aspects of cetacean behavior. Here we describe a study conducted in Babitonga Bay, southern Brazil, where we investigated the synchrony of breathing in two small populations of franciscana (Pontoporia blainvillei) and Guiana dolphins (Sotalia guianensis). The bay is affected by different sources of anthropogenic disturbances, such as boat activity and point‐source pollution. We assumed breathing synchrony to be the inverse of the time between breathing surfacing displays of dolphins within a swimming pair, which we refer to as lag. The relationship between lag and anthropogenic and animal‐related variables was evaluated with generalized additive models. For franciscana dolphins, breathing synchrony was only positively related to the proximity between animals. Breathing synchrony in Guiana dolphins was positively related to both the proximity between animals and to group size, and varied significantly depending on the research boat used. Proximal characteristics (i.e., of individuals or of the group) of these dolphin species seem to be more related to the synchronization in breathing than are the environmental variables assessed here. Results presented expand the current knowledge of these two dolphin species and provide general insights into the breathing synchrony for cetaceans.     

Temperatures in Pigs During 3 T MRI Temperatures,Heart Rates,and Breathing Rates of Pigs During RF Power Deposition in a 3 T (128 MHz) Body Coil

Exposure to radiofrequency (RF) power deposition during magnetic resonance imaging (MRI) induces elevated body‐tissue temperatures and may cause changes in heart and breathing rates, disturbing thermoregulation. Eleven temperature sensors were placed in muscle tissue and one sensor in the rectum (measured in 10 cm depth) of 20 free‐breathing anesthetized pigs to verify temperature curves during RF exposure. Tissue temperatures and heart and breathing rates were measured before, during, and after RF exposure. Pigs were placed into a 60‐cm diameter whole‐body resonator of a 3 T MRI system. Nineteen anesthetized pigs were divided into four RF exposure groups: sham (0 W/kg), low‐exposure (2.7 W/kg, mean exposure time 56 min), moderate‐exposure (4.8 W/kg, mean exposure time 31 min), and high‐exposure (4.4 W/kg, mean exposure time 61 min). One pig was exposed to a whole‐body specific absorption rate (wbSAR) of 11.4 W/kg (extreme‐exposure). Hotspot temperatures, measured by sensor 2, increased by mean 5.0 ± 0.9°C, min 3.9; max 6.3 (low), 7.0 ± 2.3°C, min 4.6; max 9.9 (moderate), and 9.2 ± 4.4°C, min 6.1, max 17.9 (high) compared with 0.3 ± 0.3°C in the sham‐exposure group (min 0.1, max 0.6). Four time‐temperature curves were identified: sinusoidal, parabolic, plateau, and linear. These curve shapes did not correlate with RF intensity, rectal temperature, breathing rate, or heart rate. In all pigs, rectal temperatures increased (2.1 ± 0.9°C) during and even after RF exposure, while hotspot temperatures decreased after exposure. When rectal temperature increased by 1°C, hotspot temperature increased up to 42.8°C within 37 min (low‐exposure) or up to 43.8°C within 24 min (high‐exposure). Global wbSAR did not correlate with maximum hotspot. Bioelectromagnetics. 2021;42:37–50. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society     

Hedonic Functions of Monosodium Glutamate and Four Basic Taste Substances Used at Various Concentration Levels in Single and Complex Systems

An in vitro DNA-directed protein-synthesizing system of Bacillus subtilis was developed using vegetative and sporulating cell extracts. Protease activity was inhibited by the addition of three kinds of protease inhibitors and removed from the extracts by hemoglobin-Sepharose treatment. Endogenous RNA synthesis was very low because of elimination of endogenous DNA by polyethylene glycol 6000 treatment of the supernatant. Protein synthesis was dependent on the DNA template, ribosomes and supernatant. When pUB110 DNA was used as a template, three proteins (Kl, K2 and K5) which have the same molecular weights as those synthesized in vivo were synthesized in vitro with vegetative, T₂ (2 hr after the end of logarithmic growth) and T₄ cell extracts.