A stereological method for estimating fish fecundity

This paper describes the application and evaluation of a stereological method for counting fish oocytes. The method has been applied to herring, Clupea harengus L., Dover sole, Solea solea L., and mackerel, Scomber scombrus L., and compared with existing volumetric and/or automated particle counter methods. The stereological method has been shown to given similar results and to have a number of distinct advantages over the other methods.     

Response of no-till and conventionally planted grain sorghum to weed control method and row spacing

Grain sorghum can substitute for corn as a full season crop and replace soybeans in double cropping systems with wheat in the southeastern United States. Relatively few studies have been conducted to measure the response of grain sorghum to tillage, weed control method, and row spacing. These experiments were designed to determine the effects of weed control method and row spacing on no-till planted grain sorghum (Sorghum bicolor L. Moench G1516-BR) after wheat (Triticum aestivum L. Coker 68–15) and crimson clover (Trifolium incarnatum L. Bigbee) grown for winter forage in comparison to sorghum planted on a conventionally prepared seedbed. The experiment included 45, 60, and 90 cm row spacings and three weed control regimes: none, mechanical, and chemical. Grain sorghum planted no-till in crimson clover or wheat sod yielded considerably more grain than conventionally planted sorghum. Grain sorghum produced significantly higher yields in 45-cm rows than in 60-and 90-cm row spacings with all three planting methods. Effects of chemical weed control on weed population with all tillage methods and on grain yield with conventional tillage were significant. There were no significant differences in grain protein content due to row spacing or weed control method.     

Initiation and solicitation in male-female grooming in a wild Japanese macaque troop on yakushima island

Grooming initiation among adult males and females of a Japanese macaque troop was analyzed during the non-mating season. Some gestures (“solicitation”) elicited grooming from partners at a high rate. Grooming initiation patterns were divided into two main types: (1) a male often solicited a female to groom him immediately after approaching her and was groomed by her; and (2) a female approached an alpha male selectively, and immediately groomed him. After a female groomed a male, she rarely solicited him to groom her and instead often moved away from him. These results indicated that males were motivated to be groomed, while females were more highly motivated to groom. Sex differences in grooming motivation can be explained by sex differences in the benefit to be groomed.     

Lateral bias in feeding and brachiation inHylobates

Lateralized hand use in gibbons was assessed for both food reaching and leading limb in brachiation. Sex and age effects were found in hand preference for food reaching. Adult females were all very strongly right hand preferent, whereas adult males had no across group consistent preference. Within the female group there was a strong correlation between age and strength of right handedness. When compared in terms of absolute strength of hand preference, females were found to be more strongly lateralized than males. Leading limb preference in brachiation was scored into vocal and non-vocal categories. Three subjects had a shift in preferred leading limb from the non-vocal brachiation condition to the vocal brachiation condition. This shift may be influenced by the arousal effects of species typical vocalization. The results of this study underline the importance of consideration of such factors as sex and age when interpreting behavioral lateralization data. The exploration of laterality in many different response measures is important to the achievement of a complete understanding of behavioral lateralization in primates.     

A short history of nuclear activation analysis

The major developments in the field of nuclear activation analysis, from 1936 to 1989, are discussed. The developments are grouped into five consecutive time periods. The impact of various scientists on the development of the field in the first 35 years is also discussed.     

Differences between observed and predicted energy costs at rest and during exercise in three subsistence-level populations

Estimates of daily energy expenditure are important for many areas of research in human ecology and adaptability. The most common technique for estimating human energy expenditure under field conditions, the factorial method, generally relies on activity-specific energy costs derived from published sources, based largely on North American and European subjects. There is concern that such data may not be appropriate for non-Western populations because of differences in metabolic costs. The present study addresses this concern by comparing measured vs. predicted energy costs at rest and during sub-maximal exercise in 83 subjects (52 males, 31 females) from three subsistence-level populations (Siberian herders and high-land and coastal Ecuadorian farmers). Energy costs at rest (i.e., lying, sitting and standing) and while performing a standard stepping exercise did not significantly differ among the three groups. However, resting energy costs were significantly elevated over predicted levels (+16% in men, +11% in women), whereas exercising costs were comparable to predicted values (?6% in men, +3% in women). Elevations in resting energy needs appear to reflect responses to thermal stress. These results indicate that temperature adjustments of resting energy costs are critical for accurately predicting daily energy needs among traditionally living populations. o 1996 Wiley-Liss, Inc.     

Application of radiotelemetry to the survey of acorn dispersal byApodemus mice

We examined the applicability of radiotelemetry to studies of acorn dispersal byApodemus mice and compared its efficiency with the of this spool-and-line method. Installation of a transmitter (2.2 g) onto acorns did not interfere with the transporting and feeding behavior of the mice. We were able to detect all transmitter-installed acorns and follow the daily changes in the sites in which they were hoarded, while we missed 59% of the spool-tied acorns due to mice breaking the threads. Mice carried transmitter-installed acorns farther than spool-tied ones. The radiotelemetry method is superior to the spool-and-line method and useful for the study of hoarding behavior in rodents.     

An impedimetric method for rapid screening of cosmetic preservatives

An efficient impedance method was developed for rapid evaluation of cosmetic preservatives. The method used decimal reduction time or D-value to assess preservative efficacies. The D-value, which was calculated from the plot of Log CFU ml^–1 versus time by linear regression analysis, could be obtained within 48 h. Thus, the time required for the challenge test was reduced from 4–8 weeks with the standard procedures (eg US Pharmacopeia), to 2 days with the current method. A calibration curve (r=-0.95) was established by plotting the Log CFU ml^–1 versus capacitance detection time (DT) of 108 samples. With the calibration, CFU can be estimated directly from the impedance test without plating. Two commercial biocides and several other chemicals were evaluated in a shampoo by the impedance procedure againstPseudomonas aeruginosa. The D-values obtained from the impedance test were not significantly different from those produced by the conventional plate count method. The technique was found to be particularly useful when screening a large number of compounds to find novel preservatives and synergistic preservative combinations.     

血凝法的生物载体选择与处理

用ＨＢｓＡｇＲＰＨＡ做为模式,选用羊、火鸡、鹅、人Ｏ型血球为载体,醛化后分成致敏和不致敏两种,与异嗜性抗体、中国生物制品药品检定所的参比品等作凝集试验。结果表明,无论特异性还是灵敏度都以人Ｏ型血球为最佳。在此基础上,设计了五种醛化方法处理人Ｏ型血球,共得出１８个醛化样品,经７３种不同的比较试验,筛选出最佳醛化方法为改良丙酮醛──甲醛法,采用该法醛化后血球为褐色,阴性血清和空白对照背景清晰,血球沉集点致密,下滑程度好。致敏抗—ＨＢｓＭｃＡｂ后,使ＨＢｓＡｇ灵敏度达到１～２ｎｇ／ｍｌ。为制备高质量的血凝试剂提供了最佳载体。     

Measurement of k(L)a by dynamic pressure method in pilot-plant fermentor

The dynamic pressure method (DPM) is used for measurement of k(L)a in a 1-m(3) pilot scale fermentor in coalescing (distilled water) and noncoalescing (0.3 M Na(2)SO(4) aqueous solution) batches. The method consists in recording oxygen concentration in a batch after a small pressure change (20 kPa) in the fermentor. The upward pressure change is brought about by temporary closing and subsequent throttling of outlet gas stream and the downward change by full reopening of the gas outlet. Absorption of pure oxygen yields the same k(L)a values as absorption of air. In noncoalescing batch, the downward k(L)a values are always higher than the upward values owing to spontaneous nucleation of bubbles. The experiments performed in a stirred cell confirm this behavior. Thus, only upward pressure change should be used for measurement. The correlation of k(L)a data measured in small (18-L) and large (1000-L) vessels based on power dissipated and superficial gas velocity are in a good agreement. Unlike the DPM, the classical dynamic methods yield, under the same conditions, excessively low values of k(L)a (the dynamic startup method) or fail to produce data at all (the dynamic method with interchange of air for N(2)). (c) 1994 John Wiley & Sons, Inc.